title: THz Dynamics of Nanoconfined Water by Ultrafast Optical Spectroscopy

abstract:
  We investigated the vibrational dynamics and the structural relaxation of
water nanoconfined in porous silica samples with pore size of 4 nm at different
levels of hydration and temperature. We used as spectroscopic technique the
time-resolved optical Kerr effect, which enables to investigate the ultrafast
water dynamics in a wide time (0.1-10 picosecond) or frequency (10-0.1 THz)
window. At low levels of hydration, corresponding to two complete superficial
water layers, no freezing occurs and the water remains mobile at all the
investigated temperatures, while at the fully hydration we witness to a partial
ice formation at about 248 K that coexists with the part of surface water
remaining in the supercooled state. At low hydration, both structural and
vibrational dynamics show significant modifications compared to the bulk liquid
water due to the strong interaction of the water molecules with silica
surfaces. Inner water, instead, reveals relaxation dynamics very similar to the
bulk one.


title: Calorimetry of a Bose-Einstein condensed photon gas

abstract:
  Phase transitions, as the condensation of a gas to a liquid, are often
revealed by a discontinuous behavior of thermodynamic quantities. For liquid
Helium, for example, a divergence of the specific heat signals the transition
from the normal fluid to the superfluid state. Apart from liquid helium,
determining the specific heat of a Bose gas has proven to be a challenging
task, for example for ultracold atomic Bose gases. Here we examine the
thermodynamic behavior of a trapped two-dimensional photon gas, a system that
allows us to spectroscopically determine the specific heat and the entropy of a
nearly ideal Bose gas from the classical high temperature to the Bose-condensed
quantum regime. The critical behavior at the phase transition is clearly
revealed by a cusp singularity of the specific heat. Regarded as a test of
quantum statistical mechanics, our results demonstrate a quantitative agreement
with its predictions at the microscopic level.


title:
Impact of nonlocal correlations over different energy scales: A
  Dynamical Vertex Approximation study

abstract:
  In this paper, we investigate how nonlocal correlations affect, selectively,
the physics of correlated electrons over different energy scales, from the
Fermi level to the band-edges. This goal is achieved by applying a diagrammatic
extension of dynamical mean field theory (DMFT), the dynamical vertex
approximation (D$\Gamma$A), to study several spectral and thermodynamic
properties of the unfrustrated Hubbard model in two and three dimensions.
Specifically, we focus first on the low-energy regime by computing the
electronic scattering rate and the quasiparticle mass renormalization for
decreasing temperatures at a fixed interaction strength. This way, we obtain a
precise characterization of the several steps, through which the Fermi-liquid
physics is progressively destroyed by nonlocal correlations. Our study is then
extended to a broader energy range, by analyzing the temperature behavior of
the kinetic and potential energy, as well as of the corresponding energy
distribution functions. Our findings allow us to identify a smooth, but
definite evolution of the nature of nonlocal correlations by increasing
interaction: They either increase or decrease the kinetic energy w.r.t. DMFT
depending on the interaction strength being weak or strong, respectively. This
reflects the corresponding evolution of the ground state from a nesting-driven
(Slater) to a superexchange-driven (Heisenberg) antiferromagnet (AF), whose
fingerprints are, thus, recognizable in the spatial correlations of the
paramagnetic phase. Finally, a critical analysis of our numerical results of
the potential energy at the largest interaction allows us to identify possible
procedures to improve the ladder-based algorithms adopted in the dynamical
vertex approximation.


title:
Fluctuations in reactive networks subject to extrinsic noise studied in
  the framework of the Chemical Langevin Equation

abstract:
  Theoretical and experimental studies have shown that the fluctuations of in
vivo systems break the fluctuation-dissipation theorem. One can thus ask what
information is contained in the correlation functions of protein concentrations
and how they relate to the response of the reactive network to a perturbation.
Answers to these questions are of prime importance to extract meaningful
parameters from the in vivo fluorescence correlation spectroscopy data. In this
paper we study the fluctuations of the concentration of a reactive species
involved in a cyclic network that is in a non-equilibrium steady state
perturbed by a noisy force, taking into account both the breaking of detailed
balance and extrinsic noises. Using a generic model for the network and the
extrinsic noise, we derive a Chemical Langevin Equation that describes the
dynamics of the system, we determine the expressions of the correlation
functions of the concentrations, estimate the deviation of the
fluctuation-dissipation theorem and the range of parameters in which an
effective temperature can be defined.


title:
Digital high-pass filter deconvolution by means of an infinite impulse
  response filter

abstract:
  In the application of semiconductor detectors, the charge-sensitive amplifier
is widely used in front-end electronics. The output signal is shaped by a
typical exponential decay. Depending on the feedback network, this type of
front-end electronics suffers from the ballistic deficit problem, or an
increased rate of pulse pile-ups. Moreover, spectroscopy applications require a
correction of the pulse-height, while a shortened pulse-width is desirable for
high-throughput applications. For both objectives, digital deconvolution of the
exponential decay is convenient. With a general method and the signals of our
custom charge-sensitive amplifier for cadmium zinc telluride detectors, we show
how the transfer function of an amplifier is adapted to an infinite impulse
response (IIR) filter. This paper investigates different design methods for an
IIR filter in the discrete-time domain and verifies the obtained filter
coefficients with respect to the equivalent continuous-time frequency response.
Finally, the exponential decay is shaped to a step-like output signal that is
exploited by a forward-looking pulse processing.


title: Nonlinear Landau damping of wave envelopes in a quantum plasma

abstract:
  The nonlinear theory of Landau damping of electrostatic wave envelopes (WEs)
is revisited in a quantum electron-positron (EP) pair plasma. Starting from a
Wigner-Moyal equation coupled to the Poisson equation and applying the multiple
scale technique, we derive a nonlinear Schr{\"o}dinger (NLS) equation which
governs the evolution of electrostatic WEs. It is shown that the coefficients
of the NLS equation, including the nonlocal nonlinear term, which appears due
to the resonant particles having group velocity of the WEs, are significantly
modified by the particle dispersion. The effects of the quantum parameter $H$
(the ratio of the plasmon energy to the thermal energy densities), associated
with the particle dispersion, are examined on the Landau damping rate of
carrier waves, as well as on the modulational instability of WEs. It is found
that the Landau damping rate and the decay rate of the solitary wave amplitude
are greatly reduced compared to their classical values $(H=0)$.


title:
Synthesis and texturization processes of (super)-hydrophobic fluorinated
  surfaces by atmospheric plasma

abstract:
  The synthesis and texturization processes of fluorinated surfaces by means of
atmospheric plasma are investigated and presented through an integrated study
of both the plasma phase and the resulting material surface. Three methods
enhancing the surface hydrophobicity up to the production of super-hydrophobic
surfaces are evaluated: (i) the modification of a polytetrafluoroethylene
(PTFE) surface, (ii) the plasma deposition of fluorinated coatings and (iii)
the incorporation of nanoparticles into those fluorinated films. In all the
approaches, the nature of the plasma gas appears to be a crucial parameter for
the desired property. Although a higher etching of the PTFE surface can be
obtained with a pure helium plasma, the texturization can only be created if O2
is added to the plasma, which simultaneously decreases the total etching. The
deposition of CxFy films by a dielectric barrier discharge leads to hydrophobic
coatings with water contact angles (WCAs) of 115{\textdegree}, but only the
filamentary argon discharge induces higher WCAs. Finally, nanoparticles were
deposited under the fluorinated layer to increase the surface roughness and
therefore produce super-hydrophobic hybrid coatings characterized by the
nonadherence of the water droplet at the surface.


title:
Low-density polyethylene films treated by an atmospheric Ar--O2
  post-discharge: functionalization, etching, degradation and partial recovery
  of the native wettability state

abstract:
  To optimize the adhesion of layers presenting strong barrier properties on
low-density polyethylene (LDPE) surfaces, we investigated the influence of
argon and argon-oxygen atmospheric pressure post-discharges. This study was
performed using x-ray photoelectron spectroscopy, atomic force microscopy,
optical emission spectroscopy (OES) and dynamic water contact angle (WCA)
measurements. After the plasma treatment, a slight increase in the roughness
was emphasized, more particularly for the samples treated in a post-discharge
supplied in oxygen. Measurements of the surface roughness and of the oxygen
surface concentration suggested the competition of two processes playing a role
on the surface hydrophilicity and occurring during the post-discharge
treatment: the etching and the activation of the surface. The etching rate was
estimated to about 2.7 nm.s-1 and 5.8 nm.s-1 for Ar and Ar-O2 post-discharges,
respectively. The mechanisms underlying this etching were investigated through
experiments, in which we discuss the influence of the O2 flow rate and the
distance (gap) separating the plasma torch from the LDPE surface located
downstream. O atoms and NO molecules (emitting in the UV range) detected by OES
seem to be good candidates to explain the etching process. An ageing study is
also presented to evidence the stability of the treated surfaces over 60 days.
After 60 days of storage, we showed that whatever the O2 flow rate, the treated
films registered a loss of their hydrophilic state since their WCA increased
towards a common threshold of 80{\textdegree}. This 'hydrophobic recovery'
effect was mostly attributed to the reorientation of induced polar chemical
groups into the bulk of the material. Indeed, the relative concentrations of
the carbonyl and carboxyl groups at the surface decreased with the storage time
and seemed to reach a plateau after 30 days.


title:
LDPE Surface Modifications Induced by Atmospheric Plasma Torches with
  Linear and Showerhead Configurations

abstract:
  Low density polyethylene (LDPE) surfaces have been plasma modified to improve
their nanostructural and wettability properties. These modifications can
significantly improve the deposition of subsequent layers such as films with
specific barrier properties. For this purpose, we compare the treatments
induced by two atmospheric plasma torches with different configurations
(showerhead vs. linear). The modifications of LDPE films in terms of chemical
surface composition and surface morphology are evidenced by X-ray photoelectron
spectro-scopy, water contact angles measurements, and atomic force microscopy.
A comparison between the two post-discharge treatments is achieved for several
torch-to-substrate distances (gaps), treatment times, and oxygen flow rates in
terms of etching rate, roughening rate, diffusion of oxygen into the
subsur-face and hydrophilicity. By correlating these results with the chemical
composition of the post-discharges, we identify and compare the 'species which
are responsible for the chemical surface functionalization, the surface
roughening, and etching.


title:
The influence of power and frequency on the filamentary behavior of a
  flowing DBD-application to the splitting of CO2

abstract:
  In this experimental study, a flowing dielectric barrier discharge operating
at atmospheric pressure is used for the splitting of CO2 into O2 and CO. The
influence of the applied frequency and plasma power on the microdischarge
properties is investigated to understand their role on the CO2 conversion.
Electrical measurements are carried out to explain the conversion trends and to
characterize the microdischarges through their number, their lifetime, their
intensity and the induced electrical charge. Their influence on the gas and
electrode temperatures is also evidenced through optical emission spectroscopy
and infrared imaging. It is shown that, in our configuration, the conversion
depends mostly on the charge delivered in the plasma and not on the effective
plasma voltage when the applied power is modified. Similarly, at constant total
current, a better conversion is observed at low frequencies, where a less
filamentary discharge regime with a higher effective plasma voltage than that
at a higher frequency is obtained.


title: Opportunistic Sleep Mode Strategies in Wireless Small Cell Networks

abstract:
  The design of energy-efficient mechanisms is one of the key challenges in
emerging wireless small cell networks. In this paper, a novel approach for
opportunistically switching ON/OFF base stations to improve the energy
efficiency in wireless small cell networks is proposed. The proposed approach
enables the small cell base stations to optimize their downlink performance
while balancing the load among each another, while satisfying their users'
quality-of-service requirements. The problem is formulated as a noncooperative
game among the base stations that seek to minimize a cost function which
captures the tradeoff between energy expenditure and load. To solve this game,
a distributed learning algorithm is proposed using which the base stations
autonomously choose their optimal transmission strategies. Simulation results
show that the proposed approach yields significant performance gains in terms
of reduced energy expenditures up to 23% and reduced load up to 40% compared to
conventional approaches.


title:
Unveiling the Penta-Silicene nature of perfectly aligned single and
  double strand Si-nanoribbons on Ag(110)

abstract:
  We reveal through extensive DFT calculations, confronted to key experimental
facts, the hidden penta-silicene nature of single and double strand chiral Si
nanoribbons perfectly aligned on Ag(110) surfaces, that were discovered in
2005, but whose structure remained elusive. We thus simultaneously demonstrate
the existence of penta-silicene, a recently conjectured novel pentagonal
silicon allotrope, which remained unveiled for 11 years, and which materializes
a paradigmatic shift from normal hexagonal silicene.


title: Dynamic Clustering and Sleep Mode Strategies for Small Cell Networks

abstract:
  In this paper, a novel cluster-based approach for optimizing the energy
efficiency of wireless small cell networks is proposed. A dynamic mechanism
based on the spectral clustering technique is proposed to dynamically form
clusters of small cell base stations. Such clustering enables intra-cluster
coordination among the base stations for optimizing the downlink performance
through load balancing, while satisfying users' quality-of-service
requirements. In the proposed approach, the clusters use an opportunistic base
station sleep-wake switching mechanism to strike a balance between delay and
energy consumption. The inter-cluster interference affects the performance of
the clusters and their choices of active or sleep state. Due to the lack of
inter-cluster communications, the clusters have to compete with each other to
make decisions on improving the energy efficiency. This competition is
formulated as a noncooperative game among the clusters that seek to minimize a
cost function which captures the tradeoff between energy expenditure and load.
To solve this game, a distributed learning algorithm is proposed using which
the clusters autonomously choose their optimal transmission strategies.
Simulation results show that the proposed approach yields significant
performance gains in terms of reduced energy expenditures up to 40% and reduced
load up to 23% compared to conventional approaches.


title:
Spin-orbit interactions in inversion-asymmetric 2D hole systems: a
  variational analysis

abstract:
  We present an in-depth study of the spin-orbit (SO) interactions occurring in
inversion-asymmetric two-dimensional hole gases at semiconductor
heterointerfaces. We focus on common semiconductors such as GaAs, InAs, InSb,
Ge, and Si. We develop a semi-analytical variational method to quantify SO
interactions, accounting for both structure inversion asymmetry (SIA) and bulk
inversion asymmetry (BIA). Under certain circumstances, using the
Schrieffer-Wolff (SW) transformation, the dispersion of the ground state heavy
hole subbands can be written as $E(k) = A k^2 - B k^4 \pm C k^3$ where $A$,
$B$, and $C$ are material- and structure-dependent coefficients. We provide a
simple method of calculating the parameters $A$, $B$, and $C$, yet demonstrate
that the simple SW approximation leading to a SIA (Rashba) spin splitting
$\propto k^3$ frequently breaks down. We determine the parameter regimes at
which this happens for the materials above and discuss a convenient
semi-analytical method to obtain the correct spin splitting, effective masses,
Fermi level, and subband occupancy, together with their dependence on the
charge density, dopant type, and dopant concentration for both inversion and
accumulation layers. Our results are in good agreement with fully numerical
calculations as well as with experimental findings. They suggest that a naive
application of the simple cubic Rashba model is of limited use in common
heterostructures, as well as quantum dots. Finally, we find that for the single
heterojunctions studied here the magnitudes of BIA terms are always much
smaller than those of SIA terms.


title: Optimal Computation of Avoided Words

abstract:
  The deviation of the observed frequency of a word $w$ from its expected
frequency in a given sequence $x$ is used to determine whether or not the word
is avoided. This concept is particularly useful in DNA linguistic analysis. The
value of the standard deviation of $w$, denoted by $std(w)$, effectively
characterises the extent of a word by its edge contrast in the context in which
it occurs. A word $w$ of length $k>2$ is a $\rho$-avoided word in $x$ if
$std(w) \leq \rho$, for a given threshold $\rho < 0$. Notice that such a word
may be completely absent from $x$. Hence computing all such words na\"{\i}vely
can be a very time-consuming procedure, in particular for large $k$. In this
article, we propose an $O(n)$-time and $O(n)$-space algorithm to compute all
$\rho$-avoided words of length $k$ in a given sequence $x$ of length $n$ over a
fixed-sized alphabet. We also present a time-optimal $O(\sigma n)$-time and
$O(\sigma n)$-space algorithm to compute all $\rho$-avoided words (of any
length) in a sequence of length $n$ over an alphabet of size $\sigma$.
Furthermore, we provide a tight asymptotic upper bound for the number of
$\rho$-avoided words and the expected length of the longest one. We make
available an open-source implementation of our algorithm. Experimental results,
using both real and synthetic data, show the efficiency of our implementation.


title:
Hydrostatic pressure tuned magneto-structural transition and occurrence
  of pressure induced exchange bias effect in Mn$_{0.85}$Fe$_{0.15}$NiGe alloy

abstract:
  Magnetic and magneto-functional behavior of a Fe-doped MnNiGe alloy with
nominal composition Mn$_{0.85}$Fe$_{0.15}$NiGe have been investigated in
ambient as well as in high pressure condition. The alloy undergoes first order
martensitic phase transition (MPT) around 200 K and also shows large
conventional magnetocaloric effect (MCE) ($\Delta S$ $\sim$ -21 J/kg-K for
magnetic field ($H$) changing from 0-50 kOe) around the transition in ambient
condition. Application of external hydrostatic pressure ($P$) results a shift
in MPT towards the lower temperature and a clear decrease in the saturation
moment of the alloy at 5 K. The peak value of MCE is also found to decrease
with increasing external $P$ ($\sim$ 18 J/kg-K decrease in $\Delta S$ has been
observed for $P$ = 12.5 kbar). The most interesting observation is the
occurance of exchange bias effect (EBE) on application of external $P$. The
competing ferromagnetic and antiferromagnetic interaction in presence of
external $P$ plays the pivotal role towards the observation of $P$ induced EBE.


title:
Direct Observation of Long-range field-effect from gate tuning of
  non-local conductivity

abstract:
  We report the observation of an unexpected, long-range field-effect in
WTe$_2$ devices, leading to large gate-induced changes of the transport
properties of crystals much thicker than the electrostatic screening length.
The phenomenon --which manifests itself very differently from the conventional
field-effect-- originates from the non-local nature of transport in the devices
that are thinner than the carrier mean free path, because of the dominant role
of surface scattering. We reproduce theoretically the gate dependence of the
measured classical and quantum magneto-transport in all detail, and show that
the phenomenon is caused by the gate-tuning of the bulk carrier mobility by
changing the scattering at the surface. Our results demonstrate the possibility
to gate tune the electronic properties deep in the interior of conducting
materials, avoiding limitations imposed by electrostatic screening.


title:
Energy-Efficient Resource Management in Ultra Dense Small Cell Networks:
  A Mean-Field Approach

abstract:
  In this paper, a novel approach for joint power control and user scheduling
is proposed for optimizing energy efficiency (EE), in terms of bits per unit
power, in ultra dense small cell networks (UDNs). To address this problem, a
dynamic stochastic game (DSG) is formulated between small cell base stations
(SBSs). This game enables to capture the dynamics of both queues and channel
states of the system. To solve this game, assuming a large homogeneous UDN
deployment, the problem is cast as a mean field game (MFG) in which the MFG
equilibrium is analyzed with the aid of two low-complexity tractable partial
differential equations. User scheduling is formulated as a stochastic
optimization problem and solved using the drift plus penalty (DPP) approach in
the framework of Lyapunov optimization. Remarkably, it is shown that by weaving
notions from Lyapunov optimization and mean field theory, the proposed solution
yields an equilibrium control policy per SBS which maximizes the network
utility while ensuring users' quality-of-service. Simulation results show that
the proposed approach achieves up to 18:1% gains in EE and 98.2% reductions in
the network's outage probability compared to a baseline model.


title: A Linear Time Parameterized Algorithm for Node Unique Label Cover

abstract:
  The optimization version of the Unique Label Cover problem is at the heart of
the Unique Games Conjecture which has played an important role in the proof of
several tight inapproximability results. In recent years, this problem has been
also studied extensively from the point of view of parameterized complexity.
Cygan et al. [FOCS 2012] proved that this problem is fixed-parameter tractable
(FPT) and Wahlstr\"om [SODA 2014] gave an FPT algorithm with an improved
parameter dependence. Subsequently, Iwata, Wahlstr\"om and Yoshida [2014]
proved that the edge version of Unique Label Cover can be solved in linear
FPT-time. That is, there is an FPT algorithm whose dependence on the input-size
is linear. However, such an algorithm for the node version of the problem was
left as an open problem. In this paper, we resolve this question by presenting
the first linear-time FPT algorithm for Node Unique Label Cover.


title: Holographic Quenches with a Gap

abstract:
  In order to holographically model quenches with a gapped final hamiltonian,
we consider a gravity-scalar theory in anti-de Sitter space with an infrared
hard wall. We allow a time dependent profile for the scalar field at the wall.
This induces an energy exchange between bulk and wall and generates an
oscillating scalar pulse. We argue that such backgrounds are the counterpart of
quantum revivals in the dual field theory. We perform a qualitative comparison
with the quench dynamics of the massive Schwinger model, which has been
recently analyzed using tensor network techniques. Agreement is found provided
the width of the oscillating scalar pulse is inversely linked to the energy
density communicated by the quench. We propose this to be a general feature of
holographic quenches.


title:
Continuation and Bifurcation of Grain Boundaries in the Swift-Hohenberg
  Equation

abstract:
  We study grain boundaries between striped phases in the prototypical
Swift-Hohenberg equation. We propose an analytical and numerical far-field-core
decomposition that allows us to study existence and bifurcations of grain
boundaries analytically and numerically using continuation techniques. This
decomposition overcomes problems with computing grain boundaries in a large
doubly periodic box with phase conditions. Using the spatially conserved
quantities of the time-independent Swift-Hohenberg equation, we show that
symmetric grain boundaries must select the marginally zig-zag stable stripes.
We find that as the angle between the stripes is decreased, the symmetric grain
boundary undergoes a parity-breaking pitchfork bifurcation where dislocations
at the grain boundary split into disclination pairs. A plethora of asymmetric
grain boundaries (with different angles of the far-field stripes either side of
the boundary) is found and investigated. The energy of the grain boundaries is
then mapped out. We find that when the angle between the stripes is greater
than a critical angle, the symmetric grain boundary is energetically preferred
while when the angle is less than the critical angle, the grain boundaries
where stripes on one side are parallel to the interface are energetically
preferred. Finally, we propose a classification of grain boundaries that allows
us to predict various non-standard asymmetric grain boundaries.


title: Calculating four-loop massless propagators with Forcer

abstract:
  We present Forcer, a new FORM program for the calculation of four-loop
massless propagators. The basic framework is similar to that of the Mincer
program for three-loop massless propagators: the program reduces Feynman
integrals to a set of master integrals in a parametric way. To overcome an
ineludible complexity of the program structure at the four-loop level, most of
the code was automatically generated or made with computer-assisted
derivations. Correctness of the program has been checked with the recomputation
of some quantities in the literature.


title: Supervisory Control for Behavior Composition

abstract:
  We relate behavior composition, a synthesis task studied in AI, to
supervisory control theory from the discrete event systems field. In
particular, we show that realizing (i.e., implementing) a target behavior
module (e.g., a house surveillance system) by suitably coordinating a
collection of available behaviors (e.g., automatic blinds, doors, lights,
cameras, etc.) amounts to imposing a supervisor onto a special discrete event
system. Such a link allows us to leverage on the solid foundations and
extensive work on discrete event systems, including borrowing tools and ideas
from that field. As evidence of that we show how simple it is to introduce
preferences in the mapped framework.


title: On continuous families of geometric Seifert conemanifold structures

abstract:
  We determine the Thurston's geometry possesed by any Seifert fibered
conemanifold structure in a Seifert manifold with orbit space $S^2$ and no more
than three exceptional fibres, whose singular set, composed by fibres, has at
most 3 components which can include exceptional or general fibres (the total
number of exceptional and singular fibres is less or equal than three). We also
give the method to obtain the holonomy of that structure. We apply these
results to three families of Seifert manifolds, namely, spherical, Nil
manifolds and manifolds obtained by Dehn surgery in a torus knot $K_{(r,s)}$.
As a consequence we generalize to all torus knots the results obtained in
\cite{LM2015} for the case of the left handle trefoil knot. We associate a plot
to each torus knot for the different geometries, in the spirit of Thurston.


title:
Post-Newtonian Evolution of Massive Black Hole Triplets in Galactic
  Nuclei: I. Numerical Implementation and Tests

abstract:
  Massive black-hole binaries (MBHBs) are thought to be the main source of
gravitational waves (GWs) in the low-frequency domain surveyed by ongoing and
forthcoming Pulsar Timing Array campaigns and future space-borne missions, such
as {\it eLISA}. However, many low-redshift MBHBs in realistic astrophysical
environments may not reach separations small enough to allow significant GW
emission, but rather stall on (sub)pc-scale orbits. This "last-parsec problem"
can be eased by the appearance of a third massive black hole (MBH) -- the
"intruder" -- whose action can force, under certain conditions, the inner MBHB
on a very eccentric orbit, hence allowing intense GW emission eventually
leading to coalescence. A detailed assessment of the process, ultimately driven
by the induced Kozai-Lidov oscillations of the MBHB orbit, requires a general
relativistic treatment and the inclusion of external factors, such as the
Newtonian precession of the intruder orbit in the galactic potential and its
hardening by scattering off background stars. In order to tackle this problem,
we developed a three-body Post-Newtonian (PN) code framed in a realistic
galactic potential, including both non-dissipative 1PN and 2PN terms, and
dissipative terms such as 2.5PN effects, orbital hardening of the outer binary,
and the effect of the dynamical friction on the early stages of the intruder
dynamics. In this first paper of a series devoted at studing the dynamics of
MBH triplets from a cosmological perspective, we describe, test and validate
our code.


title: Raymond Stora and Les Houches 1970

abstract:
  The marvelous Les Houches summer school of 1970 bore the trademark of Raymond
Stora.


title: Towards Conceptual Compression

abstract:
  We introduce a simple recurrent variational auto-encoder architecture that
significantly improves image modeling. The system represents the
state-of-the-art in latent variable models for both the ImageNet and Omniglot
datasets. We show that it naturally separates global conceptual information
from lower level details, thus addressing one of the fundamentally desired
properties of unsupervised learning. Furthermore, the possibility of
restricting ourselves to storing only global information about an image allows
us to achieve high quality 'conceptual compression'.


title: The Local Universe: Galaxies in 3D

abstract:
  Here I present results from individual galaxy studies and galaxy surveys in
the Local Universe with particular emphasis on the spatially resolved
properties of neutral hydrogen gas. The 3D nature of the data allows detailed
studies of the galaxy morphology and kinematics, their relation to local and
global star formation as well as galaxy environments. I use new 3D
visualisation tools to present multi-wavelength data, aided by tilted-ring
models of the warped galaxy disks. Many of the algorithms and tools currently
under development are essential for the exploration of upcoming large survey
data, but are also highly beneficial for the analysis of current galaxy
surveys.


title: Just-infinite C*-algebras

abstract:
  By analogy with the well-established notions of just-infinite groups and
just-infinite (abstract) algebras, we initiate a systematic study of
just-infinite C*-algebras, i.e., infinite dimensional C*-algebras for which all
proper quotients are finite dimensional. We give a classification of such
C*-algebras in terms of their primitive ideal space that leads to a trichotomy.
We show that just-infinite, residually finite dimensional C*-algebras do exist
by giving an explicit example of (the Bratteli diagram of) an AF-algebra with
these properties.
  Further, we discuss when C*-algebras and *-algebras associated with a
discrete group are just-infinite. If $G$ is the Burnside-type group of
intermediate growth discovered by the first named author, which is known to be
just-infinite, then its group algebra $C[G]$ and its group C*-algebra $C^*(G)$
are not just-infinite. Furthermore, we show that the algebra $B = \pi(C[G])$
under the Koopman representation $\pi$ of $G$ associated with its canonical
action on a binary rooted tree is just-infinite. It remains an open problem
whether the residually finite dimensional C*-algebra $C^*_\pi(G)$ is
just-infinite.


title:
Helly $\mathbf{EPT}$ graphs on bounded degree trees: forbidden induced
  subgraphs and efficient recognition

abstract:
  The edge intersection graph of a family of paths in host tree is called an
$EPT$ graph. When the host tree has maximum degree $h$, we say that $G$ belongs
to the class $[h,2,2]$. If, in addition, the family of paths satisfies the
Helly property, then $G \in$ Helly $[h,2,2]$.
  The time complexity of the recognition of the classes
  $[h,2,2]$ inside the class $EPT$ is open for every $h> 4$. Golumbic et al.
wonder if the only obstructions for an $EPT$ graph belonging to $[h,2,2]$ are
the chordless cycles $C_n$ for $n> h$. In the present paper, we give a negative
answer to that question, we present a family of $EPT$ graphs which are
forbidden induced subgraphs for the classes $[h,2,2]$.
  Using them we obtain a total characterization by induced forbidden subgraphs
of the classes Helly $[h,2,2]$ for $h\geq 4$ inside the class $EPT$. As a
byproduct, we prove that Helly $EPT$$\cap [h,2,2]=$ Helly $[h,2,2]$. We
characterize Helly $[h,2,2]$ graphs by their atoms in the decomposition by
clique separators. We give an efficient algorithm to recognize Helly $[h,2,2]$
graphs.


title: Integrated cooling channels in position-sensitive silicon detectors

abstract:
  We present an approach to construct position-sensitive silicon detectors with
an integrated cooling circuit. Tests on samples demonstrate that a very modest
liquid flow very effectively cool the devices up to a power dissipation of over
10~W/cm$^2$. The liquid flow is found to have a negligible impact on the
mechanical performance. A finite-element simulation predicts the cooling
performance to an accuracy of approximately 10~\%.


title: Comparing [CII], HI, and CO dynamics of nearby galaxies

abstract:
  The HI and CO components of the interstellar medium (ISM) are usually used to
derive the dynamical mass M_dyn of nearby galaxies. Both components become too
faint to be used as a tracer in observations of high-redshift galaxies. In
those cases, the 158 $\mu$m line of atomic carbon [CII] may be the only way to
derive M_dyn. As the distribution and kinematics of the ISM tracer affects the
determination of M_dyn, it is important to quantify the relative distributions
of HI, CO and [CII]. HI and CO are well-characterised observationally, however,
for [CII] only very few measurements exist. Here we compare observations of CO,
HI, and [CII] emission of a sample of nearby galaxies, drawn from the HERACLES,
THINGS and KINGFISH surveys. We find that within R_25, the average [CII]
exponential radial profile is slightly shallower than that of the CO, but much
steeper than the HI distribution. This is also reflected in the integrated
spectrum ("global profile"), where the [CII] spectrum looks more like that of
the CO than that of the HI. For one galaxy, a spectrally resolved comparison of
integrated spectra was possible; other comparisons were limited by the
intrinsic line-widths of the galaxies and the coarse velocity resolution of the
[CII] data. Using high-spectral-resolution SOFIA [CII] data of a number of star
forming regions in two nearby galaxies, we find that their [CII] linewidths
agree better with those of the CO than the HI. As the radial extent of a given
ISM tracer is a key input in deriving M_dyn from spatially unresolved data, we
conclude that the relevant length-scale to use in determining M_dyn based on
[CII] data, is that of the well-characterised CO distribution. This length
scale is similar to that of the optical disk.


title:
Importance of rotationally inelastic processes in low-energy Penning
  ionization of CHF$_3$

abstract:
  Low energy reaction dynamics can strongly depend on the internal structure of
the reactants. The role of rotationally inelastic processes in cold collisions
involving polyatomic molecules has not been explored so far. Here we address
this problem performing a merged-beam study of the He*+CHF$_3$ Penning
ionization reaction in a range of collision energies $E/k_B$=0.5--120 K. The
experimental cross sections are compared with total reaction cross sections
calculated within the framework of the quantum defect theory. We find that the
broad range of collision energies combined with the relatively small rotational
constants of \chfs makes rotationally inelastic collisions a crucial player in
the total reaction dynamics. Quantitative agreement between theory and
experiment is only obtained if the energy-dependent probability for rotational
excitation is included in the calculations, in stark contrast to previous
experiments where classical scaling laws were able to describe the results.


title: Undecidability of Two-dimensional Robot Games

abstract:
  Robot game is a two-player vector addition game played on the integer lattice
$\mathbb{Z}^n$. Both players have sets of vectors and in each turn the vector
chosen by a player is added to the current configuration vector of the game.
One of the players, called Eve, tries to play the game from the initial
configuration to the origin while the other player, Adam, tries to avoid the
origin. The problem is to decide whether or not Eve has a winning strategy. In
this paper we prove undecidability of the robot game in dimension two answering
the question formulated by Doyen and Rabinovich in 2011 and closing the gap
between undecidable and decidable cases.


title:
Ferroelectrics Manipulate Magnetic Bloch Skyrmions in a Composite
  Bilayer

abstract:
  Theoretical investigation demonstrates that the composite bilayer (i.e.,
chiral-magnetic/ferroelectric bilayer) offers the possibility of
electric-induced magnetic Skyrmions [Phys. Rev. B \textbf{94}, 014311 (2016)].
In this Article, we propose a micromagnetic model to physically manipulate
magnetic Bloch Skyrmions propagating in a chiral-magnetic thin film with a
polarized ferroelectric essential to drive the system through the converse
magnetoelectric effect. Effects caused by different velocities of the
propagation, sizes of the thin film, and strength of the magnetoelectric
couplings strongly impact on quality and quantity of the magnetic Skyrmions.


title: Teaching natural language to computers

abstract:
  "Natural Language," whether spoken and attended to by humans, or processed
and generated by computers, requires networked structures that reflect creative
processes in semantic, syntactic, phonetic, linguistic, social, emotional, and
cultural modules. Being able to produce novel and useful behavior following
repeated practice gets to the root of both artificial intelligence and human
language. This paper investigates the modalities involved in language-like
applications that computers -- and programmers -- engage with, and aims to fine
tune the questions we ask to better account for context, self-awareness, and
embodiment.


title:
Tunable spin-charge conversion through topological phase transitions in
  zigzag nanoribbons

abstract:
  We study spin-orbit torques and charge pumping in magnetic quasi-one
dimensional zigzag nanoribbons with hexagonal lattice, in the presence of large
intrinsic spin-orbit coupling. Such a system experiences topological phase
transition from a trivial band insulator to a quantum spin Hall insulator
either by tuning the magnetization direction or the intrinsic spin-orbit
coupling. We find that spin-charge conversion efficiency (i.e. spin-orbit
torque and charge pumping) is dramatically enhanced at the topological
transition, displaying a substantial angular anisotropy.


title:
Simulated interaction of MHD shock waves with a complex network-like
  region

abstract:
  We provide estimates of the wave energy reaching the solar chromosphere and
corona in a network-like magnetic field topology, including a coronal null
point. The waves are excited by an instantaneous strong subphotospheric source
and propagate through the subphotosphere, photosphere, chromosphere, transition
region, and corona with the plasma beta and other atmospheric parameters
varying by several orders of magnitude. We compare two regimes of the wave
propagation: a linear and nonlinear regime. While the amount of energy reaching
the corona is similar in both regimes, this energy is transmitted at different
frequencies. In both cases the dominant periods of waves at each height
strongly depend on the local magnetic field topology, but this distribution is
only in accordance with observations in the nonlinear case.


title: Deriving approximation tolerance constraints from verification runs

abstract:
  Approximate computing (AC) is an emerging paradigm for energy-efficient
computation. The basic idea of AC is to sacrifice high precision for low energy
by allowing for hardware which only carries out "approximately correct"
calculations. For software verification, this challenges the validity of
verification results for programs run on approximate hardware.
  In this paper, we present a novel approach to examine program correctness in
the context of approximate computing. In contrast to all existing approaches,
we start with a standard program verification and compute the allowed
tolerances for AC hardware from that verification run. More precisely, we
derive a set of constraints which - when met by the AC hardware - guarantees
the verification result to carry over to AC. Our approach is based on the
framework of abstract interpretation. On the practical side, we furthermore (1)
show how to extract tolerance constraints from verification runs employing
predicate abstraction as an instance of abstract interpretation, and (2) show
how to check such constraints on hardware designs. We exemplify our technique
on example C programs and a number of recently proposed approximate adders.


title:
Detecting components spectrally localized at astrophysical process
  frequencies in time series of the electric field vertical component of the
  earth atmosphere boundary layer

abstract:
  Signal eigenvectors and components analyser (RF Utility model patent 116242)
was used to explore the time-series of the electric field vertical component Ez
in the Earth atmosphere boundary layer. There have been detected non-coherent
complex-periodic components localized at the frequencies of gravity-wave impact
of binary stars and at the frequency of axion-photon interaction. These
components cannot be detected by means of quadrature scheme of spectral
analysis and have RMS values from 0.05 V/m to 0.5 V/m at binary stars
gravity-wave impact frequencies and from 0.7 V/m to 2.7 V/m at axion-photon
interaction frequency. It was also demonstrated that the axion-photon
interaction frequency modulates the amplitude


title: Impact of topology in causal dynamical triangulations quantum gravity

abstract:
  We investigate the impact of spatial topology in 3+1 dimensional causal
dynamical triangulations (CDT) by performing numerical simulations with
toroidal spatial topology instead of the previously used spherical topology. In
the case of spherical spatial topology we observed in the so-called phase C an
average spatial volume distribution n(t) which after a suitable time
redefinition could be identified as the spatial volume distribution of the
four-sphere. Imposing toroidal spatial topology we find that the average
spatial volume distribution n(t) is constant. By measuring the covariance
matrix of spatial volume fluctuations we determine the form of the effective
action. The difference compared to the spherical case is that the effective
potential has changed such that it allows a constant average n(t). This is what
we observe and this is what one would expect from a minisuperspace GR action
where only the scale factor is kept as dynamical variable. Although no
background geometry is put in by hand, the full quantum theory of CDT is also
with toroidal spatial toplogy able to identify a classical background geometry
around which there are well defined quantum fluctuations.


title: Closed-loop focal plane wavefront control with the SCExAO instrument

abstract:
  This article describes the implementation of a focal plane based wavefront
control loop on the high-contrast imaging instrument SCExAO (Subaru
Coronagraphic Extreme Adaptive Optics). The sensor relies on the Fourier
analysis of conventional focal-plane images acquired after an asymmetric mask
is introduced in the pupil of the instrument. This absolute sensor is used here
in a closed-loop to compensate the non-common path errors that normally affects
any imaging system relying on an upstream adaptive optics system.This specific
implementation was used to control low order modes corresponding to eight
zernike modes (from focus to spherical). This loop was successfully run on-sky
at the Subaru Telescope and is used to offset the SCExAO deformable mirror
shape used as a zero-point by the high-order wavefront sensor. The paper
precises the range of errors this wavefront sensing approach can operate within
and explores the impact of saturation of the data and how it can be bypassed,
at a cost in performance. Beyond this application, because of its low hardware
impact, APF-WFS can easily be ported in a wide variety of wavefront sensing
contexts, for ground- as well space-borne telescopes, and for telescope pupils
that can be continuous, segmented or even sparse. The technique is powerful
because it measures the wavefront where it really matters, at the level of the
science detector.


title: Nested Frobenius extensions of graded superrings

abstract:
  This paper is the result of a research project completed in the context of
the first author's Undergraduate Student Research Award from the Natural
Sciences and Engineering Research Council of Canada (NSERC).
  We prove a nesting phenomenon for twisted Frobenius extensions. Namely,
suppose $R \subseteq B \subseteq A$ are graded superrings such that $A$ and $B$
are both twisted Frobenius extensions of $R$, $R$ is contained in the center of
$A$, and $A$ is projective over $B$. Our main result is that, under these
assumptions, $A$ is a twisted Frobenius extension of $B$. This generalizes a
result of Pike and the second author, which considered the case where $R$ is a
field.


title: Effective Backscatter Approximation for Photometry in Murky Water

abstract:
  Shading-based approaches like Photometric Stereo assume that the image
formation model can be effectively optimized for the scene normals. However, in
murky water this is a very challenging problem. The light from artificial
sources is not only reflected by the scene but it is also scattered by the
medium particles, yielding the backscatter component. Backscatter corresponds
to a complex term with several unknown variables, and makes the problem of
normal estimation hard. In this work, we show that instead of trying to
optimize the complex backscatter model or use previous unrealistic
simplifications, we can approximate the per-pixel backscatter signal directly
from the captured images. Our method is based on the observation that
backscatter is saturated beyond a certain distance, i.e. it becomes scene-depth
independent, and finally corresponds to a smoothly varying signal which depends
strongly on the light position with respect to each pixel. Our backscatter
approximation method facilitates imaging and scene reconstruction in murky
water when the illumination is artificial as in Photometric Stereo.
Specifically, we show that it allows accurate scene normal estimation and
offers potentials like single image restoration. We evaluate our approach using
numerical simulations and real experiments within both the controlled
environment of a big water-tank and real murky port-waters.


title: Scrape Off Layer profiles interpreted with filament dynamics

abstract:
  A theoretical framework is developed to link the density profiles in the
Scrape Off Layer (SOL) with the fluctuations (filaments) that generate them.
The framework is based on the dynamics of independent filaments and their
statistical behaviour and can be used to rigorously understand the mechanisms
that lead to flattening and broadening of the SOL profiles as well as the
radial increase of the relative fluctuation amplitude.


title:
Neutrinos and {\gamma}-rays from the Galactic Center Region After
  H.E.S.S. Multi-TeV Measurements

abstract:
  The hypothesis of a PeVatron in the Galactic Center, emerged with the recent
{\gamma}-ray measurements of H.E.S.S., motivates the search for neutrinos from
this source. The effect of {\gamma}-ray absorption is studied: at the energies
currently probed, the known background radiation fields lead to small effects,
whereas it is not possible to exclude large effects due to new IR radiation
fields near the very Center. Precise upper limits on neutrino fluxes are
derived and the underlying hypotheses are discussed. The expected number of
events for ANTARES, IceCube and KM3NeT, based on the H.E.S.S. measurements, are
calculated. It is shown that km3-class telescopes in the Northern hemisphere
have the potential of observing high-energy neutrinos from this important
astronomical object and can check the existence of a hadronic PeV galactic
accelerator.


title:
Ignition and extinction phenomena in helium micro hollow cathode
  discharges

abstract:
  Micro hollow cathode discharges (MHCD) were produced using 250 m thick
dielectric layer of alumina sandwiched between two nickel electrodes of 8 m
thickness. A through cavity at the center of the chip was formed by laser
drilling technique. MHCD with a diameter of few hundreds of micrometers allowed
us to generate direct current discharges in helium at up to atmospheric
pressure. A slowly varying ramped voltage generator was used to study the
ignition and the extinction periods of the microdischarges. The analysis was
performed by using electrical characterisation of the V-I behaviour and the
measurement of He*(3S1) metastable atoms density by tunable diode laser
spectroscopy. At the ignition of the microdischarges, 2 s long current peak as
high as 24 mA was observed, sometimes followed by low amplitude damped
oscillations. At helium pressure above 400 Torr, an oscillatory behaviour of
the discharge current was observed just before the extinction of the
microdischarges. The same type of instability in the extinction period at high
pressure also appeared on the density of He*(3S1) metastable atoms, but delayed
by a few s relative to the current oscillations. Metastable atoms thus cannot
be at the origin of the generation of the observed instabilities.


title:
Identification of Photovoltaic Arrays' Maximum Power Extraction Point
  via Dynamic Regressor Extension and Mixing

abstract:
  This paper deals with the problem of identification of photovoltaic arrays'
maximum power extraction point---information that is encrypted in the
current-voltage characteristic equation. We propose a new parameterisation of
the classical five parameter model of this function that, combined with the
recently introduced identification technique of dynamic regressor extension and
mixing, ensures a fast and accurate estimation of all unknown parameters. A
concavity property of the current-voltage characteristic equation is then
exploited to directly identify the desired voltage operating point. Realistic
numerical examples via computer simulations are presented to assess the
performance of the proposed approach.


title: RF impedance measurements of DC atmospheric micro-discharges

abstract:
  The available diagnostics for atmospheric micro-plasmas remain limited and
relatively complex to implement; so we present a radio-frequency technique for
diagnosing a key parameter here. The technique allows one to estimate the
dependencies of the electron density by measuring the RF-impedance of the
micro-plasma and analyzing it with an appropriate equivalent circuit. This
technique is inexpensive, can be used in real time and gives reasonable results
for argon and helium DC micro-plasmas in holes over a wide pressure range. The
electron density increases linearly with current in the expected range
consistent with normal glow discharge behavior.


title:
Reactivity of water vapor in an atmospheric pressure DBD -Application to
  LDPE surfaces

abstract:
  The reactivity of water vapor introduced in an atmospheric dielectric barrier
discharge supplied in argon is investigated through optical emission
spectroscopy measurements. This discharge is also used for the treatment of
LDPE surfaces. Water contact angles measurements, XPS and AFM techniques are
used to study the grafting of oxygen functions on the LDPE surface and increase
its hydrophilicity.


title:
Influence of ambient air on the flowing afterglow of an atmospheric
  pressure Ar/O2 radiofrequency plasma

abstract:
  The influence of ambient air on the flowing afterglow of an atmospheric
pressure Ar/O2 radiofrequency plasma has been investigated experimentally.
Spatially resolved mass spectrometry and laser induced fluorescence on OH
radicals were used to estimate the intrusion of air in between the plasma torch
and the substrate as a function of the torch-to-substrate separation distance.
No air is detected, within the limits of measurement uncertainties, for
separation distances smaller than 5 mm. For larger distances, the effect of
ambient air can no longer be neglected, and radial gradients in the
concentrations of species appear. The Ar 4p population, determined through
absolute optical emission spectroscopy, is seen to decrease with separation
distance, whereas a rise in emission from the N2(C--B) system is measured. The
observed decay in Ar 4p and N2(C) populations for separation distances greater
than 9mm is partly assigned to the increasing collisional quenching rate by N2
and O2 molecules from the entrained air. Absorption measurements also point to
the formation of ozone at concentrations from 10^14 to 10^15 cm-3, depending
both on the injected O2 flow rate and the torch-to-substrate separation
distance.


title: Ortho-polygon Visibility Representations of Embedded Graphs

abstract:
  An ortho-polygon visibility representation of an $n$-vertex embedded graph
$G$ (OPVR of $G$) is an embedding-preserving drawing of $G$ that maps every
vertex to a distinct orthogonal polygon and each edge to a vertical or
horizontal visibility between its end-vertices. The vertex complexity of an
OPVR of $G$ is the minimum $k$ such that every polygon has at most $k$ reflex
corners. We present polynomial time algorithms that test whether $G$ has an
OPVR and, if so, compute one of minimum vertex complexity. We argue that the
existence and the vertex complexity of an OPVR of $G$ are related to its number
of crossings per edge and to its connectivity. More precisely, we prove that if
$G$ has at most one crossing per edge (i.e., $G$ is a 1-plane graph), an OPVR
of $G$ always exists while this may not be the case if two crossings per edge
are allowed. Also, if $G$ is a 3-connected 1-plane graph, we can compute an
OPVR of $G$ whose vertex complexity is bounded by a constant in $O(n)$ time.
However, if $G$ is a 2-connected 1-plane graph, the vertex complexity of any
OPVR of $G$ may be $\Omega(n)$. In contrast, we describe a family of
2-connected 1-plane graphs for which an embedding that guarantees constant
vertex complexity can be computed in $O(n)$ time. Finally, we present the
results of an experimental study on the vertex complexity of ortho-polygon
visibility representations of 1-plane graphs.


title:
In-depth diffusion of oxygen into LDPE exposed to an Ar--O2 atmospheric
  post-discharge: a complementary approach between AR-XPS and Tof-SIMS
  techniques

abstract:
  The in-depth oxygen diffusion into a low density polyethylene film is
performed in the post-discharge of an atmospheric plasma torch, supplied in
argon as carrier gas and with or without oxygen as reactive gas. The chemical
and structural properties of the polymer surface and bulk are studied in terms
of plasma parameters (treatment time, power, and reactive gas flow rate). A
good correlation between XPS and Fourier transform infrared spectroscopy
analyses is demonstrated. The penetration depth of oxygen into the bulk of the
polymer is investigated by angle resolved-XPS and time-of-flight SIMS. It is
shown that, depending on the plasma conditions, oxygen could penetrate up to
20--40 nm into the low density polyethylene during the atmospheric plasma
treatment.


title:
A method to Implement the Kerberos User Authentication and the secured
  Internet Service

abstract:
  This paper proposes a PKINIT_AS Kerberos V5 authentication system to use
public key cryptography and a method to implement the gssapi_krb authentication
method and secured Internet service using it in IPSec VPN


title:
An accurate and self-consistent chemical abundance catalogue for the
  APOGEE/Kepler sample

abstract:
  Context. The APOGEE survey has obtained high-resolution infrared spectra of
more than 100,000 stars. Deriving chemical abundances patterns of these stars
is paramount to piecing together the structure of the Milky Way. While the
derived chemical abundances have been shown to be precise for most stars, some
calibration problems have been reported, in particular for more metal- poor
stars. Aims. In this paper, we aim to (1) re-determine the chemical abundances
of the APOGEE+Kepler stellar sample (APOKASC) with an independent procedure,
line list and line selection, and high quality surface gravity information from
astroseismology, and (2) extend the abundance catalogue by including abundances
that are not currently reported in the most recent APOGEE release (DR12).
Methods. We fixed the Teff and log g to those determined using
spectrophotometric and asteroseismic techniques, respectively. We made use of
the Brussels Automatic Stellar Parameter (BACCHUS) code to derive the
metallicity and broadening parameters for the APOKASC sample. In addition, we
derived differential abundances with respect to Arcturus. Results. We have
validated the BACCHUS code on APOGEE data using several well-known stars, and
stars from open and globular clusters. We also provide the abundances of C, N,
O, Mg, Ca, Si, Ti, S, Al, Na, Ni, Mn, Fe, K, P, Cr, Co, Cu, Rb, Yb and V for
every star, line, and show the impact of line selection on the final
abundances. These include abundances of five new elements and improved
abundances for Si, Ti, S, and V. Conclusions. In this paper, we present an
independent analysis of the APOKASC sample and provide abundances of up to 21
elements. This catalogue can be used not only to study chemical abundance
patterns of the Galaxy but also to train data driven spectral approaches which
can improve the abundance precision in a restricted dataset, but also full
APOGEE sample.


title:
Chemical and Physical Effects of the Carrier Gas on the Atmospheric
  Pressure PECVD of Fluorinated Precursors

abstract:
  The atmospheric pressure PECVD deposition and texturization of hydrophobic
coatings using liquid fluorinated C6F12 and C6F14 precursors are investigated.
The effect of the carrier gas (argon and helium) is discussed in terms of the
behavior of the gas phase and of the characteristics of the deposited film.
Mass spectrom-etry measurements indicate that the fragmentation is higher with
argon while helium reacts very easily with oxygen impurities leading to the
formation of CxFyOz compounds. These observations are consistent with the
chemical composition of the films determined by XPS and the variation in the
deposition rate. Moreover, the streamers present in the argon discharge affect
the morphology of the surface by increasing the roughness, which leads to the
increase in the hydrophobicity of the coatings.


title: Direct current parallel microdischarges in helium

abstract:
  Parallel Micro Hollow Cathodes Discharges are characterised by electrical and
spectroscopic studies and by using an ICCD camera. V-I curves present a
hysteresis cycle between Townsend and normal glow regimes. For I d =4-10mA, gas
temperature ranges between 300-500{\textdegree}C. When the diameter of a hole
decreases, a more significant discharge voltage is needed.


title:
Hydrogen peroxide generated by an atmospheric He-O2-H2O flowing
  post-discharge: production mechanisms and absolute quantification

abstract:
  An atmospheric plasma torch has been supplied with a gaseous mixture of
helium, water vapour and/or oxygen to study the production of reactive species
within its flowing post-discharge, in particular hydrogen peroxide. The
mechanisms responsible for the production of H2O2 have been investigated by
correlating measurements of mass spectrometry and absorption photospectrometry.
An absolute quantification of H2O2 has also been achieved and indicated that
for 5 mmol of water vapour injected in the He-H2O discharge, approximately 9.5
mol of H2O2 were produced in post-discharge.


title: Resilience of a synchronized multi-agent system

abstract:
  Fault tolerance is increasingly important for unmanned autonomous vehicles.
For example, in a multi robot system the agents need the ability to effectively
detect and tolerate internal failures in order to continue performing their
tasks without the need for immediate human intervention. The system must react
to unplanned events in order to optimize the task allocation between the
robots. In a broad sense, the resilience of a system can be defined as the
ability to maintain or recover a stable state when subject to disturbance and
it is related to the concept of robustness in industrial systems. In this
paper, we study the resilience in a synchronized multi-robot system stated as
follows:Consider a team of $n$ (ground or aerial) robots each moving along
predetermined periodic closed trajectories. Each of the agents needs to
communicate informationabout its operation to other agents, but the
communication links have a limited range. Hence, when two agents are within
communication range, a communication link is established, and information is
exchanged. Thus, two neighbors are synchronized if they visit the communication
link at the same time and a multi-robot system is called synchronized if each
pair of neighbors is synchronized. If a set of robots left the system, then
some trajectories has no robots. In these cases, when an alive robot detects no
neighboring robot then it pass to this neighboring trajectory to assume the
unattended task. In this framework, a fault-tolerance measure is introduced:
the resilience of the system is the largest number of robots that can fail
while executing the global task. Interesting combinatorial properties of the
resilience are showed that allow to know its value for some usual scenarios.


title:
CO2 splitting by DBD: understanding the influence of electrical
  parameters and regimes

abstract:
  Plasma processes are an innovative approach for the decomposition of CO2 in O
radicals and CO as a valuable carbon source. In this experimental work, a
tubular dielectric barrier discharge operating at atmospheric pressure has been
used to split CO2 and study its conversion considering the influence of
frequency and power, as well as the influence of various electrical regimes
(AC, AC pulsed regimes). The CO2 conversion has been measured by mass
spectrometry and gas chromatography while gas and walls temperatures have been
determined and correlated to evaluate their influence of the CO2 splitting.


title:
Mesh Interest Point Detection Based on Geometric Measures and Sparse
  Refinement

abstract:
  Three dimensional (3D) interest point detection plays a fundamental role in
3D computer vision and graphics. In this paper, we introduce a new method for
detecting mesh interest points based on geometric measures and sparse
refinement (GMSR). The key point of our approach is to calculate the 3D
interest point response function using two intuitive and effective geometric
properties of the local surface on a 3D mesh model, namely Euclidean distances
between the neighborhood vertices to the tangent plane of a vertex and the
angles of normal vectors of them. The response function is defined in
multi-scale space and can be utilized to effectively distinguish 3D interest
points from edges and flat areas. Those points with local maximal 3D interest
point response value are selected as the candidates of 3D interest points.
Finally, we utilize an $\ell_0$ norm based optimization method to refine the
candidates of 3D interest points by constraining its quality and quantity.
Numerical experiments demonstrate that our proposed GMSR based 3D interest
point detector outperforms current several state-of-the-art methods for
different kinds of 3D mesh models.


title: Neutrino Mass Ordering Studies with PINGU and IceCube/DeepCore

abstract:
  The Precision IceCube Next Generation Upgrade (PINGU) is a proposed extension
to the IceCube detector. The design of PINGU would augment the existing 86
strings with an additional 40 with the main goal of determining the neutrino
mass ordering (NMO). Preliminary studies of the NMO can start with
IceCube/DeepCore, a sub-array of more densely- packed strings in operation
since 2011. This detector has a neutrino energy threshold of roughly 10 GeV and
allows for high-statistics datasets of atmospheric neutrinos to be collected.
This data provides a unique opportunity to better understand the systematic
effects involved in making the NMO measurement by comparing the simulation
studies to real data. These proceedings will present the current status of
these studies in Monte Carlo simulations with projected DeepCore sensitivity
for the NMO.


title: A variational approach to dissipative SPDEs with singular drift

abstract:
  We prove global well-posedness for a class of dissipative semilinear
stochastic evolution equations with singular drift and multiplicative Wiener
noise. In particular, the nonlinear term in the drift is the superposition
operator associated to a maximal monotone graph everywhere defined on the real
line, on which no continuity nor growth assumptions are imposed. The hypotheses
on the diffusion coefficient are also very general, in the sense that the noise
does not need to take values in spaces of continuous, or bounded, functions in
space and time. Our approach combines variational techniques with a priori
estimates, both pathwise and in expectation, on solutions to regularized
equations.


title:
Dynamics of Hubbard Hamiltonians with the multiconfigurational
  time-dependent Hartree method for indistinguishable particles

abstract:
  We apply the multiconfigurational time-dependent Hartree method for
indistinguishable particles (MCTDH-X) to systems of bosons or fermions in
lattices described by Hubbard type Hamiltonians with long-range or short-range
interparticle interactions. The wavefunction is expanded in a variationally
optimized time-dependent many-body basis generated by a set of effective
creation operators that are related to the original particle creation operators
by a time-dependent unitary transform. We use the time-dependent variational
principle for the coefficients of this transform as well as the expansion
coefficients of the wavefunction in the time-dependent many-body basis as
variational parameters to derive equations of motion. The convergence of
MCTDH-X is shown by comparing its results to the exact diagonalization of one-,
two-, and three-dimensional lattices filled with bosons with contact
interactions. We use MCTDH-X to study the buildup of correlations in the
long-time splitting dynamics of a Bose-Einstein condensate loaded into a large
two-dimensional lattice subject to a barrier that is ramped up in the center.
We find that the system is split into two parts with emergent time-dependent
correlations that depend on the ramping time -- for most barrier-raising-times
the system becomes two-fold fragmented, but for some of the very fast ramps,
the system shows revivals of coherence.


title: Improved IKE Protocol Design Based On PKI/ECC

abstract:
  This Paper proposes an ECDH key exchange method and an ECsig Digital
Signature Authentication method based on group with Koblits curve,
man-in-the-middle attack prevention method for SA payload and initiator
identification payload to design high intensity IKE that can be implemented in
portable devices.


title:
Experimental study and simulation of a micro-discharge with limited
  cathode area

abstract:
  We report in this paper simulation results and experimental measurements to
characterize a micro-discharge generated in a single micro cavity device
operating in helium. By spatially limiting the cathode surface area using a
dielectric layer, we demonstrate the ability of the micro-discharge to work in
a steady-state abnormal glow regime. The physical properties of this regime are
discussed.


title: Thermodynamics of Accelerating Black Holes

abstract:
  We address a long-standing problem of describing the thermodynamics of a
charged accelerating black hole. We derive a standard first law of black hole
thermodynamics, with the usual identification of entropy proportional to the
area of the event horizon -- even though the event horizon contains a conical
singularity. This result not only extends the applicability of black hole
thermodynamics to realms previously not anticipated, it also opens a
possibility for studying novel properties of an important class of exact
radiative solutions of Einstein equations describing accelerated objects. We
discuss the thermodynamic volume, stability and phase structure of these black
holes.


title: Quantale-valued Approach Spaces via Closure and Convergence

abstract:
  For a quantale $\mathsf{V}$ we introduce $\mathsf{V}$-approach spaces via
$\mathsf{V}$-valued point-set-distance functions and, when $\mathsf{V}$ is
completely distributive, characterize them in terms of both, so-called closure
towers and ultrafilter convergence relations. When $\mathsf{V}$ is the
two-element chain $\mathsf{2}$, the extended real half-line $[0,\infty]$, or
the quantale ${\bf{\Delta}}$ of distance distribution functions, the general
setting produces known and new results on topological spaces, approach spaces,
and the only recently considered probabilistic approach spaces, as well as on
their functorial interactions with each other.


title:
Improved IKE Key Exchange Protocol Combined with Computer Security USB
  Key Device

abstract:
  : In this paper we suggest improved IKE key exchange protocol combined with
the Computer Security USB Key device to solve the problems in using IKE and IKE
v2 protocol.


title:
Etching Processes of Polytetrafluoroethylene Surfaces Exposed to He and
  He-O2 Atmospheric Post-discharges

abstract:
  A comparative study of polytetrafluoroethylene (PTFE) surfaces treated by the
post-discharge of He and He-O2 plasmas at atmospheric pressure is presented.
The characterization of treated PTFE surfaces and the species involved in the
surface modification are related. In pure He plasmas, no significant change of
the surface has been observed by X-ray photoelectron spectroscopy (XPS),
dynamic water contact angles (dWCA) and atomic force microscopy (AFM), in spite
of important mass losses recorded. According to these observations, a
layer-by-layer physical etching without any preferential orientation is
proposed, where the highly energetic helium metastables are the main species
responsible for the scission of --(CF2)n-- chains. In He--O 2 plasmas, as the
density of helium metastables decreases as a function of the oxygen flow rate,
the treatment leads to fewer species ejected from the PTFE surfaces (in
agreement with mass loss measurements and the detection of fluorinated species
onto aluminum foil). However, the dWCA and AFM measurements show an increase in
the hydrophobicity and the roughness of the surface. The observed alveolar
structures are assumed to be caused by an anisotropic etching where the oxygen
atoms etch mainly the amorphous phase.


title: Combining complex networks and data mining: why and how

abstract:
  The increasing power of computer technology does not dispense with the need
to extract meaningful in- formation out of data sets of ever growing size, and
indeed typically exacerbates the complexity of this task. To tackle this
general problem, two methods have emerged, at chronologically different times,
that are now commonly used in the scientific community: data mining and complex
network theory. Not only do complex network analysis and data mining share the
same general goal, that of extracting information from complex systems to
ultimately create a new compact quantifiable representation, but they also
often address similar problems too. In the face of that, a surprisingly low
number of researchers turn out to resort to both methodologies. One may then be
tempted to conclude that these two fields are either largely redundant or
totally antithetic. The starting point of this review is that this state of
affairs should be put down to contingent rather than conceptual differences,
and that these two fields can in fact advantageously be used in a synergistic
manner. An overview of both fields is first provided, some fundamental concepts
of which are illustrated. A variety of contexts in which complex network theory
and data mining have been used in a synergistic manner are then presented.
Contexts in which the appropriate integration of complex network metrics can
lead to improved classification rates with respect to classical data mining
algorithms and, conversely, contexts in which data mining can be used to tackle
important issues in complex network theory applications are illustrated.
Finally, ways to achieve a tighter integration between complex networks and
data mining, and open lines of research are discussed.

categories: physics.soc-ph cs.DB cs.IR cs.SI physics.data-an


title:
Multi-part Nordhaus-Gaddum type problems for tree-width, Colin de
  Verdi\`ere type parameters, and Hadwiger number

abstract:
  A traditional Nordhaus-Gaddum problem for a graph parameter $\beta$ is to
find a (tight) upper or lower bound on the sum or product of $\beta(G)$ and
$\beta(\bar{G})$ (where $\bar{G}$ denotes the complement of $G$). An
$r$-decomposition $G_1,\dots,G_r$ of the complete graph $K_n$ is a partition of
the edges of $K_n$ among $r$ spanning subgraphs $G_1,\dots,G_r$. A traditional
Nordhaus-Gaddum problem can be viewed as the special case for $r=2$ of a more
general $r$-part sum or product Nordhaus-Gaddum type problem. We determine the
values of the $r$-part sum and product upper bounds asymptotically as $n$ goes
to infinity for the parameters tree-width and its variants largeur
d'arborescence, path-width, and proper path-width. We also establish ranges for
the lower bounds for these parameters, and ranges for the upper and lower
bounds of the $r$-part Nordhaus-Gaddum type problems for the parameters
Hadwiger number, the Colin de Verdi\`ere number $\mu$ that is used to
characterize planarity, and its variants $\nu$ and $\xi$.


title:
Chemical mechanisms inducing a dc current measured in the flowing
  post-discharge of an RF He-O2 plasma torch

abstract:
  The post-discharge of an RF plasma torch supplied with helium and oxygen
gases is characterized by mass spectrometry, optical emission spectroscopy and
electrical measurements. We have proved the existence of a dc current in the
post-discharge (1--20 A), attributed to the Penning ionization of atmospheric
nitrogen and oxygenated species. The mechanisms ruling this dc current are
investigated through experiments in which we discuss the influence of the O2
flow rate, the He flow rate and the distance separating the plasma torch from a
material surface located downstream.


title: Anti-van der Waerden numbers of 3-term arithmetic progressions

abstract:
  The \emph{anti-van der Waerden number}, denoted by $aw([n],k)$, is the
smallest $r$ such that every exact $r$-coloring of $[n]$ contains a rainbow
$k$-term arithmetic progression. Butler et. al. showed that $\lceil \log_3 n
\rceil + 2 \le aw([n],3) \le \lceil \log_2 n \rceil + 1$, and conjectured that
there exists a constant $C$ such that $aw([n],3) \le \lceil \log_3 n \rceil +
C$. In this paper, we show this conjecture is true by determining $aw([n],3)$
for all $n$. We prove that for $7\cdot 3^{m-2}+1 \leq n \leq 21 \cdot 3^{m-2}$,
\[ aw([n],3)=\left\{\begin{array}{ll} m+2, & \mbox{if $n=3^m$}\\ m+3, &
\mbox{otherwise}.
  \end{array}\right.\]


title: BASE - The Baryon Antibaryon Symmetry Experiment

abstract:
  The Baryon Antibaryon Symmetry Experiment (BASE) aims at performing a
stringent test of the combined charge parity and time reversal (CPT) symmetry
by comparing the magnetic moments of the proton and the antiproton with high
precision. Using single particles in a Penning trap, the proton/antiproton
$g$-factors, i.e. the magnetic moment in units of the nuclear magneton, are
determined by measuring the respective ratio of the spin-precession frequency
to the cyclotron frequency. The spin precession frequency is measured by
non-destructive detection of spin quantum transitions using the continuous
Stern-Gerlach effect, and the cyclotron frequency is determined from the
particle's motional eigenfrequencies in the Penning trap using the invariance
theorem. By application of the double Penning-trap method we expect that in our
measurements a fractional precision of $\delta g/g$ 10$^{-9}$ can be achieved.
The successful application of this method to the antiproton will represent a
factor 1000 improvement in the fractional precision of its magnetic moment. The
BASE collaboration has constructed and commissioned a new experiment at the
Antiproton Decelerator (AD) of CERN. This article describes and summarizes the
physical and technical aspects of this new experiment.


title: Integrated micro-plasmas in silicon operating in helium

abstract:
  Microplasma arrays operating in helium in a DC regime have been produced in
silicon microre-actors. Cathode boundary layer (CBL) type microdevices were
elaborated using clean room facilities and semiconductor processing techniques.
Ignition of the micro-discharge arrays having either 50 or 100 m diameter
cavities was studied. Two different structures (isotropically etched or
anisotropically etched cavity) and various conditions (the two different
voltage polarities, pressures etc.) were investigated. 100 microdis-charges of
50 m diameter could be ignited in parallel at 1000 torr. At high current, some
parasitic and transient sparks appeared at the edge of the sample. When the
polarization was reversed (cathode side corresponding the opened electrode),
more current was needed to light all the microdischarges. A thermally affected
zone around the hole on the anode side was obtained after operation.


title: Unified Correspondence and Proof Theory for Strict Implication

abstract:
  The unified correspondence theory for distributive lattice expansion logics
(DLE-logics) is specialized to strict implication logics. As a consequence of a
general semantic consevativity result, a wide range of strict implication
logics can be conservatively extended to Lambek Calculi over the bounded
distributive full non-associative Lambek calculus (BDFNL). Many strict
implication sequents can be transformed into analytic rules employing one of
the main tools of unified correspondence theory, namely (a suitably modified
version of) the Ackermann lemma based algorithm $\msf{ALBA}$. Gentzen-style
cut-free sequent calculi for BDFNL and its extensions with analytic rules which
are transformed from strict implication sequents, are developed.


title:
Opening the Frey/Osborne Black Box: Which Tasks of a Job are Susceptible
  to Computerization?

abstract:
  In their seminal paper, Frey and Osborne quantified the automation of jobs,
by assigning each job in the O*NET database a probability to be automated. In
this paper, we refine their results in the following way: Every O*NET job
consists of a set of tasks, and these tasks can be related. We use a linear
program to assign probabilities to tasks, such that related tasks have a
similar probability and the tasks can explain the computerization probability
of a job. Analyzing jobs on the level of tasks helps comprehending the results,
as experts as well as laymen can more easily criticize and refine what parts of
a job are susceptible to computerization.


title:
A new structural stochastic volatility model of asset pricing and its
  stylized facts

abstract:
  Building on a prominent agent-based model, we present a new structural
stochastic volatility asset pricing model of fundamentalists vs. chartists
where the prices are determined based on excess demand. Specifically, this
allows for modelling stochastic interactions between agents, based on a herding
process corrected by a price misalignment, and incorporating strong noise
components in the agents' demand. The model's parameters are estimated using
the method of simulated moments, where the moments reflect the basic properties
of the daily returns of a stock market index. In addition, for the first time
we apply a (parametric) bootstrap method in a setting where the switching
between strategies is modelled using a discrete choice approach. As we
demonstrate, the resulting dynamics replicate a rich set of the stylized facts
of the daily financial data including: heavy tails, volatility clustering, long
memory in absolute returns, as well as the absence of autocorrelation in raw
returns, volatility-volume correlations, aggregate Gaussianity, concave price
impact and extreme price events.


title: Forms of social relationships in distinct cultural settings

abstract:
  We contribute to the understanding of social relationships within cultural
contexts by proposing a connection between a social theory, relational models
theory (RMT: Fiske 1991, 1992) and a social and political one, cultural or
plural rationality theory (PRT: Douglas, 1982, Thompson et al., 1990). Drawing
examples from the literature of both theories, we argue that each relational
model of RMT may be implemented in ways compatible with each cultural bias of
PRT. A cultural bias restrains the range of congruent implementations of
relational models, but does not preclude any relational model altogether. This
stands in contrast to earlier reconciliation attempts between PRT and RMT.
Based on hypothetical one-to-one mappings, these attempts expect each cultural
setting to be significantly associated with some, but not all, relational
models. The framework we develop helps explain the findings of these previous
attempts and provides insights into empirical research by clarifying which
associations to expect between relationships and cultural contexts. We discuss
the theoretical basis of our framework, including the idea that RMT and PRT
apply to different levels of analysis: RMT's relational models are tied to
relationships between two actors and PRT's cultural biases to structures of
social networks.


title: Improved Dense Trajectory with Cross Streams

abstract:
  Improved dense trajectories (iDT) have shown great performance in action
recognition, and their combination with the two-stream approach has achieved
state-of-the-art performance. It is, however, difficult for iDT to completely
remove background trajectories from video with camera shaking. Trajectories in
less discriminative regions should be given modest weights in order to create
more discriminative local descriptors for action recognition. In addition, the
two-stream approach, which learns appearance and motion information separately,
cannot focus on motion in important regions when extracting features from
spatial convolutional layers of the appearance network, and vice versa. In
order to address the above mentioned problems, we propose a new local
descriptor that pools a new convolutional layer obtained from crossing two
networks along iDT. This new descriptor is calculated by applying
discriminative weights learned from one network to a convolutional layer of the
other network. Our method has achieved state-of-the-art performance on ordinal
action recognition datasets, 92.3% on UCF101, and 66.2% on HMDB51.


title:
A protosolar nebula origin for the ices agglomerated by Comet
  67P/Churyumov-Gerasimenko

abstract:
  The nature of the icy material accreted by comets during their formation in
the outer regions of the protosolar nebula is a major open question in
planetary science. Some scenarios of comet formation predict that these bodies
agglomerated from crystalline ices condensed in the protosolar nebula.
Concurrently, alternative scenarios suggest that comets accreted amorphous ice
originating from the interstellar cloud or from the very distant regions of the
protosolar nebula. On the basis of existing laboratory and modeling data, we
find that the N$_2$/CO and Ar/CO ratios measured in the coma of the Jupiter
family comet 67P/Churyumov-Gerasimenko by the ROSINA instrument aboard the
European Space Agency's Rosetta spacecraft match those predicted for gases
trapped in clathrates. If these measurements are representative of the bulk
N$_2$/CO and Ar/CO ratios in 67P/Churyumov-Gerasimenko, it implies that the
ices accreted by the comet formed in the nebula and do not originate from the
interstellar medium, supporting the idea that the building blocks of outer
solar system bodies have been formed from clathrates and possibly from pure
crystalline ices. Moreover, because 67P/Churyumov-Gerasimenko is impoverished
in Ar and N$_2$, the volatile enrichments observed in Jupiter's atmosphere
cannot be explained solely via the accretion of building blocks with similar
compositions and require an additional delivery source. A potential source may
be the accretion of gas from the nebula that has been progressively enriched in
heavy elements due to photoevaporation.


title: Branched twist spins and knot determinants

abstract:
  A branched twist spin is a generalization of twist spun knots, which appeared
in the study of locally smooth circle actions on the $4$-sphere due to
Montgomery, Yang, Fintushel and Pao. In this paper, we give a sufficient
condition to distinguish non-equivalent, non-trivial branched twist spins by
using knot determinants. To prove the assertion, we give a presentation of the
fundamental group of the complement of a branched twist spin, which generalizes
a presentation of Plotnick, calculate the first elementary ideals and obtain
the condition of the knot determinants by substituting $-1$ for the
indeterminate.


title:
Engineering interactions and anyon statistics by multicolor
  lattice-depth modulations

abstract:
  We show that a multicolor modulation of the depth of an optical lattice
allows for a flexible independent control of correlated hopping,
occupation-dependent gauge fields, effective on-site interactions without
Feshbach resonances, and nearest-neighbor interactions. As a result, the
lattice-depth modulation opens the possibility of engineering with minimal
experimental complexity a broad class of lattice models in current experiments
with ultra-cold atoms, including Hubbard models with correlated hopping,
peculiar extended models, and two-component anyon-Hubbard models.


title:
Boundary singularities of solutions of semilinear elliptic equations in
  the half-space with a Hardy potential

abstract:
  We study a nonlinear equation in the half-space $\{x_1>0\}$ with a Hardy
potential, specifically \[-\Delta u
-\frac{\mu}{x_1^2}u+u^p=0\quad\text{in}\quad \mathbb R^n_+,\] where $p>1$ and
$-\infty<\mu<1/4$. The admissible boundary behavior of the positive solutions
is either $O(x_1^{-2/(p-1)})$ as $x_1\to 0$, or is determined by the solutions
of the linear problem $-\Delta h -\frac{\mu}{x_1^2}h=0$. In the first part we
study in full detail the separable solutions of the linear equations for the
whole range of $\mu$. In the second part, by means of sub and supersolutions we
construct separable solutions of the nonlinear problem which behave like
$O(x_1^{-2/(p-1)})$ near the origin and which, away from the origin have
exactly the same asymptotic behavior as the separable solutions of the linear
problem. In the last part we construct solutions that behave like
$O(x_1^{-2/(p-1)})$ at some prescribed parts of the boundary, while at the rest
of the boundary the solutions decay or blowup at a slower rate determined by
the linear part of the equation.


title: Origin of molecular oxygen in Comet 67P/Churyumov-Gerasimenko

abstract:
  Molecular oxygen has been detected in the coma of comet
67P/Churyumov-Gerasimenko with abundances in the 1-10% range by the ROSINA-DFMS
instrument on board the Rosetta spacecraft. Here we find that the radiolysis of
icy grains in low-density environments such as the presolar cloud may induce
the production of large amounts of molecular oxygen. We also show that
molecular oxygen can be efficiently trapped in clathrates formed in the
protosolar nebula, and that its incorporation as crystalline ice is highly
implausible because this would imply much larger abundances of Ar and N2 than
those observed in the coma. Assuming that radiolysis has been the only O2
production mechanism at work, we conclude that the formation of comet
67P/Churyumov-Gerasimenko is possible in a dense and early protosolar nebula in
the framework of two extreme scenarios: (1) agglomeration from pristine
amorphous icy grains/particles formed in ISM and (2) agglomeration from
clathrates that formed during the disk's cooling. The former scenario is found
consistent with the strong correlation between O2 and H2O observed in 67P/C-G's
coma while the latter scenario requires that clathrates formed from ISM icy
grains that crystallized when entering the protosolar nebula.


title: Fluctuation-dissipation relations far from equilibrium

abstract:
  Near equilibrium, where all currents of a system vanish on average, the
fluctuation-dissipation relation (FDR) connects a current's spontaneous
fluctuations with its response to perturbations of the conjugate thermodynamic
force. Out of equilibrium, fluctuation-response relations generally involve
additional nondissipative contributions. Here, in the framework of stochastic
thermodynamics, we show that an equilibrium-like FDR holds for internally
equilibrated currents, if the perturbing conjugate force only affects the
microscopic transitions that contribute to the current. We discuss the physical
requirements for the validity of our result and apply it to nano-sized
electronic devices.


title:
Viewpoint: Opportunities and challenges of two-dimensional magnetic van
  der Waals materials: magnetic graphene?

abstract:
  There has been a huge increase of interests in two-dimensional van der Waals
materials over the past ten years or so with the conspicuous absence of one
particular class of materials: magnetic van der Waals systems. In this
Viewpoint, we point it out and illustrate how we might be able to benefit from
exploring these so-far neglected materials.


title: Compactification of strata of abelian differentials

abstract:
  We describe the closure of the strata of abelian differentials with
prescribed type of zeros and poles, in the projectivized Hodge bundle over the
Deligne-Mumford moduli space of stable curves with marked points. We provide an
explicit characterization of pointed stable differentials in the boundary of
the closure, both a complex analytic proof and a flat geometric proof for
smoothing the boundary differentials, and numerous examples. The main new
ingredient in our description is a global residue condition arising from a full
order on the dual graph of a stable curve.


title: A perturbative quantized twist embedded in Minkowski spacetime

abstract:
  In this article, spatially-structured gravitational waves are investigated.
Drawing upon analogies between electrodynamics and general relativity, a new
gauge is found. We investigate the polarization and degrees of freedom of the
resulting radiation. The waves are found to carry orbital angular momentum that
cam be transferred to matter.


title: $Z_c(3900)$ as a $D\bar{D}^*$ molecule from the pole counting rule

abstract:
  A comprehensive study on the nature of the $Z_c(3900)$ resonant structure is
carried out in this work. By constructing the pertinent effective Lagrangians
and considering the important final-state-interaction effects, we first give a
unified description to all the relevant experimental data available, including
the $J/\psi\pi$ and $\pi\pi$ invariant mass distributions from the $e^+e^-\to
J/\psi\pi\pi$ process, the $h_c\pi$ distribution from $e^+e^-\to h_c\pi\pi$ and
also the $D\bar D^{*}$ spectrum in the $e^+e^-\to D\bar D^{*}\pi$ process.
After fitting the unknown parameters to the previous data, we search the pole
in the complex energy plane and find only one pole in the nearby energy region
in different Riemann sheets. Therefore we conclude that $Z_c(3900)$ is of
$D\bar D^*$ molecular nature, according to the pole counting rule
method~[Nucl.~Phys.~A543, 632 (1992); Phys.~Rev.~D 35,~1633 (1987)]. We
emphasize that the conclusion based upon the pole counting method is not
trivial, since both the $D\bar D^{*}$ contact interactions and the explicit
$Z_c$ exchanges are introduced in our analyses and they lead to the same
conclusion.


title: Representations of symmetric groups with non-trivial determinant

abstract:
  We give a closed formula for the number of partitions $\lambda$ of $n$ such
that the corresponding irreducible representation $V_\lambda$ of $S_n$ has
non-trivial determinant. We determine how many of these partitions are
self-conjugate and how many are hooks. This is achieved by characterizing the
$2$-core towers of such partitions. We also obtain a formula for the number of
partitions of $n$ such that the associated permutation representation of $S_n$
has non-trivial determinant.


title: Warm Little Inflaton

abstract:
  We show that inflation can naturally occur at a finite temperature T>H that
is sustained by dissipative effects, when the inflaton field corresponds to a
pseudo Nambu-Goldstone boson of a broken gauge symmetry. Similarly to "Little
Higgs" scenarios for electroweak symmetry breaking, the flatness of the
inflaton potential is protected against both quadratic divergences and the
leading thermal corrections. We show that, nevertheless, nonlocal dissipative
effects are naturally present and are able to sustain a nearly thermal bath of
light particles despite the accelerated expansion of the Universe. As an
example, we discuss the dynamics of chaotic warm inflation with a quartic
potential and show that the associated observational predictions are in very
good agreement with the latest Planck results. This model constitutes the first
realization of warm inflation requiring only a small number of fields; in
particular, the inflaton is directly coupled to just two light fields.


title:
Design study of compact Laser-Electron X-ray Generator for material and
  life science applications

abstract:
  X-Ray generations utilizing Thomson scattering fill in the gap that exists
between conventional and synchrotron-based X-ray sources. They are expected to
be more intense than X-ray tubes and more compact, accessible and less
expensive than synchrotron. In this work, two operation modes of Thomson X-ray
source are documented: quasi CW(QCW) and a pulsed one are considered for
material sciences and medical applications being implemented currently at
Synchrotron Radiation (SR) facilities.


title:
Engineering Large Stark Shifts for Control of Individual Clock State
  Qubits

abstract:
  In quantum information science, the external control of qubits must be
balanced with the extreme isolation of the qubits from the environment. Atomic
qubit systems typically mitigate this balance through the use of gated laser
fields that can create superpositions and entanglement between qubits. Here we
propose the use of high-order optical Stark shifts from optical fields to
manipulate the splitting of atomic qubits that are insensitive to other types
of fields. We demonstrate a fourth-order AC Stark shift in a trapped atomic ion
system that does not require extra laser power beyond that needed for other
control fields. We individually address a chain of tightly-spaced trapped ions
and show how these controlled shifts can produce an arbitrary product state of
ten ions as well as generate site-specific magnetic field terms in a simulated
spin Hamiltonian.


title: On the structure of sets with positive reach

abstract:
  We give a complete characterization of compact sets with positive reach
(=proximally $C^1$ sets) in the plane and of one-dimensional sets with positive
reach in ${\mathbb R}^d$. Further, we prove that if $\emptyset \neq
A\subset{\mathbb R}^d$ is a set of positive reach of topological dimension $0<
k \leq d$, then $A$ has its "$k$-dimensional regular part" $\emptyset \neq R
\subset A$ which is a $k$-dimensional "uniform" $C^{1,1}$ manifold open in $A$
and $A\setminus R$ can be locally covered by finitely many $(k-1)$-dimensional
DC surfaces. We also show that if $A \subset {\mathbb R}^d$ has positive reach,
then $\partial A$ can be locally covered by finitely many semiconcave
hypersurfaces.


title:
Critical Casimir Interactions and Percolation: the quantitative
  description of critical fluctuations

abstract:
  Casimir forces in a critical media are produced by spatial suppression of
order parameter fluctuations. In this paper we address the question how
fluctuations of a critical media relates the magnitude of critical Casimir
interactions. Namely, for the Ising model we express the potential of critical
Casimir interactions in terms of Fortuin-Kasteleyn site-bond correlated
percolation clusters. These clusters are quantitative representation of
fluctuations in the media. New Monte Carlo method for the computation of the
Casimir force potential which is based on this relation is proposed. We verify
this method by computation of Casimir interactions between two disks for 2D
Ising model. The new method is also applied to the investigation of
non-additivity of the critical Casimir potential. The non-additive contribution
to three-particles interaction is computed as a function of the temperature.