title: Disentangling the surface and bulk electronic structures of LaOFeAs

abstract:
  We performed a comprehensive angle-resolved photoemission spectroscopy study
of the electronic band structure of LaOFeAs single crystals. We found that
samples cleaved at low temperature show an unstable and highly complicated band
structure, whereas samples cleaved at high temperature exhibit a stable and
clearer electronic structure. Using \emph{in-situ} surface doping with K and
supported by first-principles calculations, we identify both surface and bulk
bands. Our assignments are confirmed by the difference in the temperature
dependence of the bulk and surface states.


title:
Resummation of Jet Veto Logarithms at partial N$^3$LL + NNLO for
  $W^+W^-$ Production at the LHC

abstract:
  We compute the resummed on-shell $W^+ W^-$ production cross section under a
jet-veto at the LHC to partial N$^3$LL order matched to the fixed order NNLO
result. Differential NNLO cross sections are obtained from an implementation of
$q_T$ subtraction in Sherpa. The two-loop virtual corrections to the $q \bar q
\rightarrow W^+ W^-$ amplitude, used in both fixed order and resummation
predictions, are extracted from the public code {\tt qqvvamp}. We perform
resummation using soft collinear effective theory (SCET), with approximate beam
functions where only the logarithmic terms are included at two-loop. In
addition to scale uncertainties from the hard matching scale and the
factorization scale, rapidity scale variations are obtained within the analytic
regulator approach. Our resummation results show a decrease in the jet-veto
cross-section compared to NNLO fixed order predictions, with reduced scale
uncertainties compared to NNLL+NLO resummed predictions. We include the
loop-induced $gg$ contribution with jet veto resummation to NLL+LO. The
prediction shows good agreement with recent LHC measurements.


title: Uniqueness result for long range spatially segregation elliptic system

abstract:
  We study a class of elliptic competition-diffusion systems of long range
segregation models for two and more competing species. The existence and
uniqueness of the solution are shown. We prove that as the competition rate
goes to infinity the solution converges, along with suitable sequences, to a
spatially long range segregated state satisfying some free boundary problems.


title:
A note on generalization of Zermelo navigation problem on Riemannian
  manifolds with strong perturbation

abstract:
  We generalize the Zermelo navigation problem and its solution on Riemannian
manifolds $(M, h)$ admitting a space dependence of a ship's speed
$0<|u(x)|_h\leq1$ in the presence of a perturbation $\tilde{W}$ determined by a
strong velocity vector field satisfying $|\tilde{W}(x)|_h=|u(x)|_h$, with
application of Finsler metric of Kropina type.


title: GRVI Phalanx: A Massively Parallel RISC-V FPGA Accelerator Accelerator

abstract:
  GRVI is an FPGA-efficient RISC-V RV32I soft processor. Phalanx is a parallel
processor and accelerator array framework. Groups of processors and
accelerators form shared memory clusters. Clusters are interconnected with each
other and with extreme bandwidth I/O and memory devices by a 300- bit-wide
Hoplite NOC. An example Kintex UltraScale KU040 system has 400 RISC-V cores,
peak throughput of 100,000 MIPS, peak shared memory bandwidth of 600 GB/s, NOC
bisection bandwidth of 700 Gbps, and uses 13 W.


title:
RCFD: A Novel Channel Access Scheme for Full-Duplex Wireless Networks
  Based on Contention in Time and Frequency Domains

abstract:
  In the last years, the advancements in signal processing and integrated
circuits technology allowed several research groups to develop working
prototypes of in-band full-duplex wireless systems. The introduction of such a
revolutionary concept is promising in terms of increasing network performance,
but at the same time poses several new challenges, especially at the MAC layer.
Consequently, innovative channel access strategies are needed to exploit the
opportunities provided by full-duplex while dealing with the increased
complexity derived from its adoption. In this direction, this paper proposes
RTS/CTS in the Frequency Domain (RCFD), a MAC layer scheme for full-duplex ad
hoc wireless networks, based on the idea of time-frequency channel contention.
According to this approach, different OFDM subcarriers are used to coordinate
how nodes access the shared medium. The proposed scheme leads to efficient
transmission scheduling with the result of avoiding collisions and exploiting
full-duplex opportunities. The considerable performance improvements with
respect to standard and state-of-the-art MAC protocols for wireless networks
are highlighted through both theoretical analysis and network simulations.


title: Gaussian Processes for Music Audio Modelling and Content Analysis

abstract:
  Real music signals are highly variable, yet they have strong statistical
structure. Prior information about the underlying physical mechanisms by which
sounds are generated and rules by which complex sound structure is constructed
(notes, chords, a complete musical score), can be naturally unified using
Bayesian modelling techniques. Typically algorithms for Automatic Music
Transcription independently carry out individual tasks such as multiple-F0
detection and beat tracking. The challenge remains to perform joint estimation
of all parameters. We present a Bayesian approach for modelling music audio,
and content analysis. The proposed methodology based on Gaussian processes
seeks joint estimation of multiple music concepts by incorporating into the
kernel prior information about non-stationary behaviour, dynamics, and rich
spectral content present in the modelled music signal. We illustrate the
benefits of this approach via two tasks: pitch estimation, and inferring
missing segments in a polyphonic audio recording.


title:
Soft McEliece: MDPC code-based McEliece cryptosystems with very compact
  keys through real-valued intentional errors

abstract:
  We propose to use real-valued errors instead of classical bit flipping
intentional errors in the McEliece cryptosystem based on moderate-density
parity-check (MDPC) codes. This allows to exploit the error correcting
capability of these codes to the utmost, by using soft-decision iterative
decoding algorithms instead of hard-decision bit flipping decoders. However,
soft reliability values resulting from the use of real-valued noise can also be
exploited by attackers. We devise new attack procedures aimed at this, and
compute the relevant work factors and security levels. We show that, for a
fixed security level, these new systems achieve the shortest public key sizes
ever reached, with a reduction up to 25% with respect to previous proposals.


title: Surface defects as transfer matrices

abstract:
  The supersymmetric index of the 4d $\mathcal{N} = 1$ theory realized by a
brane tiling coincides with the partition function of an integrable 2d lattice
model. We argue that a class of half-BPS surface defects in brane tiling models
are represented on the lattice model side by transfer matrices constructed from
L-operators. For the simplest surface defects in theories with $\mathrm{SU}(2)$
flavor groups, we identify the relevant L-operator as that discovered by
Sklyanin in the context of the eight-vertex model. We verify this
identification by computing the indices of class-$\mathcal{S}$ and
-$\mathcal{S}_k$ theories in the presence of the surface defects.


title: Machine Learning for E-mail Spam Filtering: Review,Techniques and Trends

abstract:
  We present a comprehensive review of the most effective content-based e-mail
spam filtering techniques. We focus primarily on Machine Learning-based spam
filters and their variants, and report on a broad review ranging from surveying
the relevant ideas, efforts, effectiveness, and the current progress. The
initial exposition of the background examines the basics of e-mail spam
filtering, the evolving nature of spam, spammers playing cat-and-mouse with
e-mail service providers (ESPs), and the Machine Learning front in fighting
spam. We conclude by measuring the impact of Machine Learning-based filters and
explore the promising offshoots of latest developments.


title: On the average size of independent sets in triangle-free graphs

abstract:
  We prove an asymptotically tight lower bound on the average size of
independent sets in a triangle-free graph on $n$ vertices with maximum degree
$d$, showing that an independent set drawn uniformly at random from such a
graph has expected size at least $(1+o_d(1)) \frac{\log d}{d}n$. This gives an
alternative proof of Shearer's upper bound on the Ramsey number $R(3,k)$. We
then prove that the total number of independent sets in a triangle-free graph
with maximum degree $d$ is at least $\exp \left[\left(\frac{1}{2}+o_d(1)
\right) \frac{\log^2 d}{d}n \right]$. The constant $1/2$ in the exponent is
best possible. In both cases, tightness is exhibited by a random $d$-regular
graph.
  Both results come from considering the hard-core model from statistical
physics: a random independent set $I$ drawn from a graph with probability
proportional to $\lambda^{|I|}$, for a fugacity parameter $\lambda>0$. We prove
a general lower bound on the occupancy fraction (normalized expected size of
the random independent set) of the hard-core model on triangle-free graphs of
maximum degree $d$. The bound is asymptotically tight in $d$ for all $\lambda
=O_d(1)$.
  We conclude by stating several conjectures on the relationship between the
average and maximum size of an independent set in a triangle-free graph and
give some consequences of these conjectures in Ramsey theory.


title:
Analogue black holes in relativistic BECs: Mimicking Killing and
  universal horizons

abstract:
  Relativistic Bose-Einstein condensates (rBECs) have recently become a
well-established system for analogue gravity. Indeed, while such relativistic
systems cannot be yet realized experimentally, they provide an interesting
framework for mimicking metrics for which no analogue is yet available, so
paving the way for further theoretical and numerical explorations. In this
vein, we here discuss black holes in rBECs and explore how their features
relate to the bulk properties of the system. We then propose the coupling of
external fields to the rBEC as a way to mimic non-metric features. In
particular, we use a Proca field to simulate an aether field, as found in
Einstein-Aether or Horava-Lifshitz gravity. This allows us to mimic a universal
horizon, the causal barrier relevant for superluminal modes in these modified
gravitational theories.


title: Physical Zero-Knowledge Proofs for Akari, Takuzu, Kakuro and KenKen

abstract:
  Akari, Takuzu, Kakuro and KenKen are logic games similar to Sudoku. In Akari,
a labyrinth on a grid has to be lit by placing lanterns, respecting various
constraints. In Takuzu a grid has to be filled with 0's and 1's, while
respecting certain constraints. In Kakuro a grid has to be filled with numbers
such that the sums per row and column match given values; similarly in KenKen a
grid has to be filled with numbers such that in given areas the product, sum,
difference or quotient equals a given value. We give physical algorithms to
realize zero-knowledge proofs for these games which allow a player to show that
he knows a solution without revealing it. These interactive proofs can be
realized with simple office material as they only rely on cards and envelopes.
Moreover, we formalize our algorithms and prove their security.


title:
General planar transverse domain walls realized by optimized transverse
  magnetic field pulses in magnetic biaxial nanowires

abstract:
  We report the realization of a planar transverse domain wall (TDW) with
arbitrary tilting angle in a magnetic biaxial nanowire under a transverse
magnetic field (TMF) pulse with fixed strength and optimized orientation
profile. We smooth any twisting in azimuthal angle plane of a TDW and thus
completely decouple the polar and azimuthal degrees of freedom. The analytical
differential equation that describes the polar angle distribution is then
derived and the resulting solution is not a Walker-ansatz form. With this
optimized TMF pulse comoving, the field-driven dynamics of the planar TDW is
investigated. It turns out the comoving TMF pulse increases the wall velocity
under the same axial driving field. These results will help to design a series
of modern logic and memory nanodevices based on general planar TDWs.


title:
Tetraquark states in the bottom sector and the status of the
  $Y_b$(10890) state

abstract:
  We have done the exploratory study of bottom tetraquarks ($[bq\bar b \bar
q];{q\in u,d}$) in the diquark-antidiquark framework with the inclusion of spin
hyperfine, spin-orbit and tensor components of the one gluon exchange
interaction. Our focus here is on the $Y_b$(10890) and other exotic states in
the bottom sector. We have predicted some of the bottom counterparts to the
charm tetraquark candidates. Our present study shows that if $Z_b(10610)$ and
$Z_b(10650)$ are diquark-diantiquark states then they have to be first radial
excitations only and we have predicted $Z_b(10650)$ state as first radial
excitation of tetraquark state $X_b$ (10.143-10.230). We have identified $X_b$
state with $J^{PC}= 1^{+-}/0^{++}$ as being the analogue of $Z_c(3900)$. An
observation of the $X_b$ will provide a deeper insight into the exotic hadron
spectroscopy and is helpful to unravel the nature of the states connected by
the heavy quark symmetry. We particularly focus on the lowest P wave $[bq][\bar
b\bar q]$ states with $J^{PC}=1^{--}$ by computing their leptonic, hadronic and
radiative decay widths to predict the status of still controversial
$Y_b$(10890) state. Apart from this, we have also shown here the possibility of
mixing of P wave states. In the case of mixing of $1^{--}$ state with different
spin multiplicities, we found that predicted masses of the mixed P states
differ from $Y_b$(10890) state only by $\pm20$ MeV energy difference which can
be helpful to resolve further the structure of $Y_b$(10890).


title: Serendipity Face and Edge VEM Spaces

abstract:
  We extend the basic idea of Serendipity Virtual Elements from the previous
case (by the same authors) of nodal ($H^1$-conforming) elements, to a more
general framework. Then we apply the general strategy to the case of $H(div)$
and $H(curl)$ conforming Virtual Element Methods, in two and three dimensions.


title:
H-atom addition and abstraction reactions in mixed CO, H2CO and CH3OH
  ices: an extended view on complex organic molecule formation

abstract:
  Complex organic molecules (COMs) have been observed not only in the hot cores
surrounding low- and high- mass protostars, but also in cold dark clouds.
Therefore, it is interesting to understand how such species can be formed
without the presence of embedded energy sources. We present new laboratory
experiments on the low-temperature solid state formation of three complex
molecules: methyl formate (HC(O)OCH3), glycolaldehyde (HC(O)CH2OH) and ethylene
glycol (H2C(OH)CH2OH), through recombination of free radicals formed via H-atom
addition and abstraction reactions at different stages in the CO-H2CO-CH3OH
hydrogenation network at 15 K. The experiments extend previous CO hydrogenation
studies and aim at resembling the physical&chemical conditions typical of the
CO freeze-out stage in dark molecular clouds, when H2CO and CH3OH form by
recombination of accreting CO molecules and H-atoms on ice grains. We confirm
that H2CO, once formed through CO hydrogenation, not only yields CH3OH through
ongoing H-atom addition reactions, but is also subject to H-atom-induced
abstraction reactions, yielding CO again. In a similar way, H2CO is also formed
in abstraction reactions involving CH3OH. The dominant methanol H-atom
abstraction product is expected to be CH2OH, while H-atom additions to H2CO
should at least partially proceed through CH3O intermediate radicals. The
occurrence of H-atom abstraction reactions in ice mantles leads to more
reactive intermediates (HCO, CH3O and CH2OH) than previously thought, when
assuming sequential H-atom addition reactions only. This enhances the
probability to form COMs through radical-radical recombination without the need
of UV photolysis or cosmic rays as external triggers.


title:
Fully gapped superconductivity in the topological superconductor
  beta-PdBi2

abstract:
  The recent discovery of the topologically protected surface states in the
beta-phase of PdBi2 has reignited the research interest in this class of
superconductors. Here, we show results of our muon spin relaxation and rotation
(muSR) measurements carried out to investigate the superconducting and magnetic
properties and the topological effect in the superconducting ground state of
beta-PdBi2. Zero-field muSR data reveal that no sizeable spontaneous
magnetization arises with the onset of superconductivity implying that the time
reversal symmetry is preserved in the superconducting state of beta-PdBi2.
Further, a strong diamagnetic shift of the applied field has been observed in
the transverse-field (TF) muSR experiments, indicating that any triplet-pairing
channel, if present, does not dominate the superconducting condensate. Using
TF-muSR, we estimate that the magnetic penetration depth is 263(10) nm at zero
temperature. Temperature dependence of the magnetic penetration depth provides
evidence for the existence of a nodeless single s-wave type isotropic energy
gap of 0.78(1) meV at zero temperature. Our results further suggest that the
topologically protected surface states have no effect on the bulk of the
superconductor.


title:
Measures of Basicity in Silicate Minerals Revealed by Alkali Exchange
  Energetics

abstract:
  The energies of the alkali exchange reactions are computed from density
functional calculations for a series of alkali silicate minerals.
First-principles calculations are compared against (1) experiment; (2)
thermodynamic models; (3) calculations using empirical interatomic potentials
(with both polarizable shell model potentials and pairwise potentials with
partial charges); and (4) empirical correlations based on optical basicity and
Pauling bond strength. The first-principles calculations correlate well with
experimental values. The shell model potentials appear to account for Si-O-Si
versus Si-O oxygen basicity, but don't recover the differences in basicity
between Al-O-Si and Si-O-Si donors. The pair potentials don't even
qualitatively reproduce the reactivity trends established in the
first-principles calculations. Empirical correlations based on optical basicity
and Pauling bond strength successfully rank-order the exchange energies, but
fail to describe the large difference in basicity between Si-O-Si and Si-O
oxygen atoms. Knowing which models are capable of predicting ion exchange
energies in silicate minerals improves understanding of the physics of bonding
in ion-exchanged glasses.


title:
The LHC di-photon excess and Gauge Coupling Unification in Extra
  $Z^\prime$ Heterotic-String Derived Models

abstract:
  The di-photon excess observed at the LHC can be explained as a Standard Model
singlet that is produced and decays by heavy vector-like colour triplets and
electroweak doublets in one-loop diagrams. The characteristics of the required
spectrum are well motivated in heterotic-string constructions that allow for a
light $Z^\prime$. Anomaly cancellation of the $U(1)_{Z^\prime}$ symmetry
requires the existence of the Standard Model singlet and vector-like states in
the vicinity of the $U(1)_{Z^\prime}$ breaking scale. In this paper we show
that the agreement with the gauge coupling data at one-loop is identical to the
case of the Minimal Supersymmetric Standard Model, owing to cancellations
between the additional states. We further show that effects arising from heavy
thresholds may push the supersymmetric spectrum beyond the reach of the LHC,
while maintaining the agreement with the gauge coupling data. We show that the
string inspired model can indeed account for the observed signal and discuss
the feasibility of obtaining viable scalar mass spectrum.


title: Splitting quaternion algebras over quadratic number fields

abstract:
  We propose an algorithm for finding zero divisors in quaternion algebras over
quadratic number fields, or equivalently, solving homogeneous quadratic
equations in three variables over $\mathbb{Q}(\sqrt{d})$ where $d$ is a
square-free integer. The algorithm is randomized and runs in polynomial time if
one is allowed to call oracles for factoring integers.


title: The rotating Navier- Stokes- Fourier- Poisson system on thin domains

abstract:
  We consider the compressible Navier - Stokes - Fourier - Poisson system
describing the motion of a viscous heat conducting rotating fluid confined to a
straight layer $ \Omega_{\epsilon} = \omega \times (0,\epsilon) $, where
$\omega$ is a 2-D domain. The aim of this paper is to show that the weak
solutions in the 3D domain converge to the strong solution of the 2-D Navier -
Stokes - Fourier - Poisson system $\omega$ as $\epsilon \to 0$ on the time
interval, where the strong solution exists. We consider two different regimes
in dependence on the asymptotic behaviour of the Froude number.


title:
Mechanical and Structural Properties of Graphene-like Carbon Nitride
  Sheets

abstract:
  Carbon nitride-based nanostructures have attracted special attention (from
theory and experiments) due to their remarkable electromechanical properties.
In this work we have investigated the mechanical properties of some
graphene-like carbon nitride membranes through fully atomistic reactive
molecular dynamics simulations. We have analyzed three different structures of
these CN families, the so-called graphene-based g-CN, triazine-based g-C3N4 and
heptazine-based g-C3N4. The stretching dynamics of these membranes was studied
for deformations along their two main axes and at three different temperatures:
10K, 300K and 600K. We show that g-CN membranes have the lowest ultimate
fracture strain value, followed by heptazine-based and triazine-based ones,
respectively. This behavior can be explained in terms of their differences in
terms of density values, topologies and types of chemical bonds. The dependency
of the fracture patterns on the stretching directions is also discussed.


title:
Enhancing stability of correction procedure via reconstruction using
  summation-by-parts operators II: Modal filtering

abstract:
  A recently introduced framework of semidiscretisations for hyperbolic
conservation laws known as correction procedure via reconstruction (CPR, also
known as flux reconstruction) is considered in the extended setting of
summation-by-parts (SBP) operators using simultaneous approximation terms
(SATs). This reformulation can yield stable semidiscretisations for linear
advection and Burgers' equation as model problems. In order to enhance these
properties, modal filters are introduced to this framework. As a second part of
a series, the results of Ranocha, Glaubitz, \"Offner, and Sonar ("Enhancing
stability of correction procedure via reconstruction using summation-by-parts
operators I: Artificial dissipation", 2016) concerning artificial dissipation /
spectral viscosity are extended, yielding fully discrete stable schemes.
Additionally, a new adaptive strategy to compute the filter strength is
introduced and different possible applications of modal filters are compared
both theoretically and numerically.


title:
Analytical calculation of Hermite-Gauss and Laguerre-Gauss modes on a
  bullseye photodiode

abstract:
  This note describes the analytical derivation of the response of bullseye
detectors to optical beats between higher-order spatial modes of the
Laguerre-Gauss form, and subsequently the Hermite-Gauss form. Also included is
a comparison with numerically calculated beat coefficients, and a simple
example of the use of the resulting beat coefficients in simulating a mode
mismatch sensor for a Fabry-Perot cavity.


title:
Two-gluon exchange contribution to elastic $\gamma \gamma \to \gamma
  \gamma$ scattering and production of two-photons in ultraperipheral
  ultrarelativistic heavy ion and proton-proton collisions

abstract:
  We discuss the two-gluon exchange contribution (formally three-loops) to
elastic photon-photon scattering in the high-energy approximation. The elastic
$\gamma\gamma \to \gamma \gamma$ amplitude is given in the impact-factor
representation for all helicity configurations and finite quark masses. We
discuss the importance of including the charm quark, which contribution, due to
interference, can enhance the cross section considerably. We investigate the
contribution to the $\gamma \gamma \to \gamma \gamma$ amplitude from the soft
region, by studying its dependence on nonperturbative gluon mass. Helicity-flip
contributions are shown to be much smaller than helicity-conserving ones. We
identify region(s) of phase space where the two-gluon exchange contribution
becomes important ingredient compared to box and nonperturbative VDM-Regge
mechanisms considered in the literature. Consequences for the $A A \to A A
\gamma \gamma$ reaction are discussed. Several differential distributions are
shown. A feasibility study to observe the effect of two-gluon exchange is
presented. We perform a similar analysis for the $p p \to p p \gamma \gamma$
reaction. Only by imposing severe cuts on $M_{\gamma \gamma}$ and a narrow
window on photon transverse momenta the two gluon contribution becomes
comparable to the box contribution but the corresponding cross section is
rather small.


title:
Orbital evolution and search for eccentricity and apsidal motion in the
  eclipsing HMXB 4U 1700-37

abstract:
  In the absence of detectable pulsations in the eclipsing High Mass X-ray
binary 4U 1700-37, the orbital period decay is necessarily determined from the
eclipse timing measurements. We have used the earlier reported mid-eclipse time
measurements of 4U 1700-37 together with the new measurements from long term
light curves obtained with the all sky monitors RXTE-ASM, Swift-BAT and
MAXI-GSC, as well as observations with RXTE-PCA, to measure the long term
orbital evolution of the binary. The orbital period decay rate of the system is
estimated to be ${\dot{P}}/P = -(4.7 \pm 1.9) \times 10^{-7}$ yr$^{-1}$,
smaller compared to its previous estimates. We have also used the mid-eclipse
times and the eclipse duration measurements obtained from 10 years long X-ray
light-curve with Swift-BAT to separately put constraints on the eccentricity of
the binary system and attempted to measure any apsidal motion. For an apsidal
motion rate greater than 5 degrees per year, the eccentricity is found to be
less than 0.008, which limits our ability to determine the apsidal motion rate
from the current data. We discuss the discrepancy of the current limit of
eccentricity with the earlier reported values from radial velocity measurements
of the companion star.


title: Bound-States Dynamics in One-Dimensional Multi-Species Fermionic Systems

abstract:
  In this work we provide for a description of the low-energy physics of
interacting multi-species fermions in terms of the bound-states that are
stabilized in these systems when a spin gap opens. We argue that, at energies
much smaller than the spin gap, these systems are described by a Luttinger
liquid of bound-states that depends, on top of the charge stiffness $\nu$ and
the charge velocity $u$, on a "Fermi" momentum $P_F$ satisfying $qP_F = Nk_F$
where $q$ is the charge of the bound-state, $N$ the number of species and $k_F$
is the Fermi momentum in the non-interacting limit. We further argue that for
generic interactions, generic bound-states are likely to be stabilized. They
are associated with emergent, in general non-local, symmetries and are in the
number of five. The first two consist of either a charge $q=N$ local $SU(N)$
singlet or a charge $q=N$ bound-state made of two local $SU(p)$ and $SU(N-p)$
singlets. In this case the Fermi momentum $P_F=k_F$ is preserved. The three
others have an enhanced Fermi vector $P_F$. The latter are either charge $q=2$
bosonic p-wave and s-wave pairs with $SO(N)$ and $SP(N)$ symmetry and
$P_F=Nk_F/2$ or a composite fermion of charge $q=1$ with $P_F=Nk_F$. The
instabilities of these Luttinger liquid states towards incompressible phases
and their possible topological nature are also discussed.


title:
Monotonicity of solutions for some nonlocal elliptic problems in
  half-spaces

abstract:
  In this paper we consider classical solutions $u$ of the semilinear
fractional problem $(-\Delta)^s u = f(u)$ in $\mathbb{R}^N_+$ with $u=0$ in
$\mathbb{R}^N \setminus \mathbb{R}^N_+$, where $(-\Delta)^s$, $0<s<1$, stands
for the fractional laplacian, $N\ge 2$, $\mathbb{R}^N_+=\{x=(x',x_N)\in
\mathbb{R}^N:\ x_N>0\}$ is the half-space and $f\in C^1$ is a given function.
With no additional restriction on the function $f$, we show that bounded,
nonnegative, nontrivial classical solutions are indeed positive in
$\mathbb{R}^N_+$ and verify $$ \frac{\partial u}{\partial x_N}>0 \quad \hbox{in
} \mathbb{R}^N_+. $$ This is in contrast with previously known results for the
local case $s=1$, where nonnegative solutions which are not positive do exist
and the monotonicity property above is not known to hold in general even for
positive solutions when $f(0)<0$.


title:
Whittaker-Kotel'nikov-Shannon approximation of $\varphi$-sub-Gaussian
  random processes

abstract:
  The article starts with generalizations of some classical results and new
truncation error upper bounds in the sampling theorem for bandlimited
stochastic processes. Then, it investigates $L_p([0,T])$ and uniform
approximations of $\varphi$-sub-Gaussian random processes by finite time
sampling sums. Explicit truncation error upper bounds are established. Some
specifications of the general results for which the assumptions can be easily
verified are given. Direct analytical methods are employed to obtain the
results.


title:
Continuity of modulus of noncompact convexity for minimalizable measures
  of noncompactness

abstract:
  We consider the modulus of noncompact convexity
$\Delta_{X,\phi}(\varepsilon)$ associated with the minimalizable measure of
noncompactness $\phi$. We present some properties of this modulus, while the
main result of this paper is showing that $\Delta_{X,\phi }(\varepsilon)$ is a
subhomogenous and continuous function on $[0,\phi (\bar{B}_X))$ for an
arbitrary minimalizable measure of compactness $\phi$ in the case of a Banach
space $X$ with the Radon-Nikodym property.


title: Hardy spaces for semigroups with Gaussian bounds

abstract:
  Let T_t=e^{-tL} be a semigroup of self-adjoint linear operators acting on
L^2(X,mu), where (X,d mu) is a space of homogeneous type. We assume that T_t
has an integral kernel T_t(x,y) which satisfies the upper and lower Gaussian
bounds: \frac{C_1}{mu(B(x,\sqrt{t}))} \exp(-c_1d(x,y)^2/t)\leq T_t(x,y) \leq
\frac{C_2}{\mu(B(x,\sqrt{t}))} \exp(-c_2 d(x,y)^2/t). By definition, f belongs
to H^1_L if \| f\|_{H^1_L}=\|\sup_{t>0}|T_t f(x)|\|_{L^1(X,\mu)} <\infty. We
prove that there is a function \omega(x), 0<c \leq \omega(x) \leq C, such that
H^1_L admits an atomic decomposition with atoms satisfying: supp a \subset B,
\|a\|_{L^\infty} \leq mu(B)^{-1}, and the weighted cancellation condition \int
a(x)\omega(x) dmu(x)=0.


title:
Non-collinear spin-orbit magnetic fields in a carbon nanotube double
  quantum dot

abstract:
  We demonstrate experimentally that non-collinear intrinsic spin-orbit
magnetic fields can be realized in a curved carbon nanotube two-segment device.
Each segment, analyzed in the quantum dot regime, shows near four-fold
degenerate shell structure allowing for identification of the spin-orbit
coupling and the angle between the two segments. Furthermore, we determine the
four unique spin directions of the quantum states for specific shells and
magnetic fields. This class of quantum dot systems is particularly interesting
when combined with induced superconducting correlations as it may facilitate
unconventional superconductivity and detection of Cooper pair entanglement. Our
device comprises the necessary elements.


title: Atlas of monochromatic images of planetary nebulae

abstract:
  We present an atlas of more than one hundred original images of planetary
nebulae (PNe). These images were taken in a narrow-band filter centred on the
nebular emission of the [N II] during several observing campaigns using two
moderate-aperture telescopes, at the Complejo Astron\'omico El Leoncito
(CASLEO), and the Estaci\'on Astrof\'isica de Bosque Alegre (EABA), both in
Argentina. The data provided by this atlas represent one of the most extensive
image surveys of PNe in [N II]. We compare the new images with those available
in the literature, and briefly describe all cases in which our [N II] images
reveal new and interesting structures.


title:
Quantum Lakshmibai-Seshadri paths and the specialization of Macdonald
  polynomials at $t=0$ in type $A_{2n}^{(2)}$

abstract:
  In this paper, we give a combinatorial realization of the crystal basis of a
quantum Weyl module over a quantum affine algebra of type $A_{2n}^{(2)}$, and a
representation-theoretic interpretation of the specialization
$P_{\lambda}^{A_{2n}^{(2)}} (q,0)$ of the symmetric Macdonald polynomial
$P_{\lambda}^{A_{2n}^{(2)}} (q,t)$ at $t=0$, where $\lambda$ is a dominant
weight and $P_{\lambda}^{A_{2n}^{(2)}}(q,t)$ denotes the specific
specialization of the symmetric Macdonald-Koornwinder polynomial
$P_{\lambda}(q,t_1, t_2, t_3, t_4, t_5)$. More precisely, as some results for
untwisted affine types, the set of all ($A_{2n}^{(2)}$-type) quantum
Lakshmibai-Seshadri paths of shape $\lambda$, which is described in terms of
the finite Weyl group $W$, realizes the crystal basis of a quantum Weyl module
over a quantum affine algebra of type ${A_{2n}^{(2)}}$ and its graded character
is equal to the specialization $P_{\lambda}^{A_{2n}^{(2)}} (q,0)$ of the
symmetric Macdonald-Koornwinder polynomial.


title:
Hybrid waveguide-bulk multi-path interferometer with switchable
  amplitude and phase

abstract:
  We design and realise a hybrid interferometer consisting of three paths based
on integrated as well as on bulk optical components. This hybrid construction
offers a good compromise between stability and footprint on one side and means
of intervention on the other. As experimentally verified by the absence of
higher-order interferences, amplitude and phase can be manipulated in all paths
independently. In conjunction with single photons, the setup can, therefore, be
applied for fundamental investigations on quantum mechanics.


title: The Geometry of Almost Einstein (2,3,5) Distributions

abstract:
  We analyze the classic problem of existence of Einstein metrics in a given
conformal structure for the class of conformal structures inducedf Nurowski's
construction by (oriented) (2,3,5) distributions. We characterize in two ways
such conformal structures that admit an almost Einstein scale: First, they are
precisely the oriented conformal structures $\mathbf{c}$ that are induced by at
least two distinct oriented (2,3,5) distributions; in this case there is a
1-parameter family of such distributions that induce $\mathbf{c}$. Second, they
are characterized by the existence of a holonomy reduction to $SU(1,2)$,
$SL(3,{\mathbb R})$, or a particular semidirect product $SL(2,{\mathbb
R})\ltimes Q_+$, according to the sign of the Einstein constant of the
corresponding metric. Via the curved orbit decomposition formalism such a
reduction partitions the underlying manifold into several submanifolds and
endows each ith a geometric structure. This establishes novel links between
(2,3,5) distributions and many other geometries - several classical geometries
among them - including: Sasaki-Einstein geometry and its paracomplex and
null-complex analogues in dimension 5; K\"ahler-Einstein geometry and its
paracomplex and null-complex analogues, Fefferman Lorentzian conformal
structures, and para-Fefferman neutral conformal structures in dimension 4; CR
geometry and the point geometry of second-order ordinary differential equations
in dimension 3; and projective geometry in dimension 2. We describe a
generalized Fefferman construction that builds from a 4-dimensional
K\"ahler-Einstein or para-K\"ahler-Einstein structure a family of (2,3,5)
distributions that induce the same (Einstein) conformal structure. We exploit
some of these links to construct new examples, establishing the existence of
nonflat almost Einstein (2,3,5) conformal structures for which the Einstein
constant is positive and negative.


title:
Coherent diffraction of thermal currents in long Josephson tunnel
  junctions

abstract:
  We discuss heat transport in thermally-biased long Josephson tunnel junctions
in the presence of an in-plane magnetic field. In full analogy with the
Josephson critical current, the phase-dependent component of the heat current
through the junction displays coherent diffraction. Thermal transport is
analyzed as a function of both the length and the damping of the junction,
highlighting deviations from the standard Fraunhofer pattern characteristic of
short junctions. The heat current diffraction patterns show features strongly
related to the formation and penetration of Josephson vortices, i.e. solitons.
We show that a dynamical treatment of the system is crucial for the realistic
description of the Josephson junction and it leads to peculiar results. In
fact, hysteretic behaviors in the diffraction patterns when the field is swept
up and down are observed, corresponding to the trapping of vortices in the
junction.


title:
On modulus of noncompact convexity for a strictly minimalizable measure
  of noncompactness

abstract:
  In this paper we consider modulus of noncompact convexity
$\Delta_{X,\varPhi}$ associated with the strictly minimalizable measure of
noncompactness $\varPhi$. We also give some its properties and show its
continuity on the interval $[0,\varPhi(\bar{B}_X))$.


title: Small deviations of sums of correlated stationary Gaussian sequences

abstract:
  We consider the small deviation probabilities (SDP) for sums of stationary
Gaussian sequences. For the cases of constant boundaries and boundaries tending
to zero, we obtain quite general results. For the case of the boundaries
tending to infinity, we focus our attention on the discrete analogs of the
fractional Brownian motion (FBM). It turns out that the lower bounds for the
SDP can be transferred from the well studied FBM caseto the discrete time
setting under the usual assumptions that imply weak convergence while the
transfer of the corresponding upper bounds necessarily requires a deeper
knowledge of the spectral structure of the underlying stationary sequence.


title:
A model for gamma-ray binaries, based on the effect of pair production
  feedback in shocked pulsar winds

abstract:
  We analyze the model of gamma-ray binaries, consisting of a massive star and
a pulsar with ultrarelativistic wind. We consider radiation from energetic
particles, accelerated at the pulsar wind termination shock, and feedback of
this radiation on the wind through production of secondary electron-positron
pairs. We show that the pair feedback limits the Lorentz factor of the pulsar
wind and creates a population of very energetic pairs, whose radiation may be
responsible for the observed gamma-ray signal.


title:
How the IMF $\mathit{B}_{y}$ induces a $\mathit{B}_{y}$ component in the
  closed magnetosphere and how it leads to asymmetric currents and convection
  patterns in the two hemispheres

abstract:
  We used the Lyon-Fedder-Mobarry global magnetohydrodynamics model to study
the effects of the interplanetary magnetic field (IMF) IMF $\mathit{B}_{y}$
component on the coupling between the solar wind and magnetosphere-ionosphere
system. When the IMF reconnects with the terrestrial magnetic field with IMF
$\mathit{B}_{y}$ $\neq$ 0, flux transport is asymmetrically distributed between
the two hemispheres. We describe how $\mathit{B}_{y}$ is induced in the closed
magnetosphere on both the dayside and nightside and present the governing
equations. The magnetosphere imposes asymmetric forces on the ionosphere, and
the effects on the ionospheric flow are characterized by distorted convection
cell patterns, often referred to as "banana" and "orange" cell patterns. The
flux asymmetrically added to the lobes results in a non-uniform induced
$\mathit{B}_{y}$ in the closed magnetosphere. By including the dynamics of the
system, we introduce a mechanism that predicts asymmetric Birkeland currents at
conjugate foot points. Asymmetric Birkeland currents are created as a
consequence of $\textit {y}$ directed tension contained in the return flow.
Associated with these currents, we expect fast localized ionospheric azimuthal
flows present in one hemisphere but not necessarily in the other. We also
present current density measurements from Active Magnetosphere and Planetary
Electrodynamics Response Experiment that are consistent with this picture. We
argue that the induced $\mathit{B}_{y}$ produces asymmetrical Birkeland
currents as a consequence of asymmetric stress balance between the hemispheres.
Such an asymmetry will also lead to asymmetrical foot points and asymmetries in
the azimuthal flow in the ionosphere. These phenomena should therefore be
treated in a unified way.


title:
Stochastic Model of Maturation and Vesicular Exchange in Cellular
  Organelles

abstract:
  The dynamical organization of membrane-bound organelles along intracellular
transport pathways relies on vesicular exchange between organelles and on
biochemical maturation of the organelle content by specific enzymes. The
relative importance of each mechanism in controlling organelle dynamics remains
controversial, in particular for transport through the Golgi apparatus. Using a
stochastic model, we show that full maturation of membrane-bound compartments
can be seen as the stochastic escape from a steady-state in which export is
dominated by vesicular exchange. We show that full maturation can contribute a
significant fraction of the total out-flux for small organelles such as
endosomes and Golgi cisternae.


title:
Principal component analysis of Birkeland currents determined by the
  Active Magnetosphere and Planetary Electrodynamics Response Experiment

abstract:
  Principal component analysis is performed on Birkeland or field-aligned
current (FAC) measurements from the Active Magnetosphere and Planetary
Electrodynamics Response Experiment. Principal component analysis (PCA)
identifies the patterns in the FACs that respond coherently to different
aspects of geomagnetic activity. The regions 1 and 2 current system is shown to
be the most reproducible feature of the currents, followed by cusp currents
associated with magnetic tension forces on newly reconnected field lines. The
cusp currents are strongly modulated by season, indicating that their strength
is regulated by the ionospheric conductance at the foot of the field lines. PCA
does not identify a pattern that is clearly characteristic of a substorm
current wedge. Rather, a superposed epoch analysis of the currents associated
with substorms demonstrates that there is not a single mode of response, but a
complicated and subtle mixture of different patterns.


title:
A Fuzzy Approach to Qualification in Design Exploration for Autonomous
  Robots and Systems

abstract:
  Autonomous robots must operate in complex and changing environments subject
to requirements on their behaviour. Verifying absolute satisfaction (true or
false) of these requirements is challenging. Instead, we analyse requirements
that admit flexible degrees of satisfaction. We analyse vague requirements
using fuzzy logic, and probabilistic requirements using model checking. The
resulting analysis method provides a partial ordering of system designs,
identifying trade-offs between different requirements in terms of the degrees
to which they are satisfied. A case study involving a home care robot
interacting with a human is used to demonstrate the approach.


title: Generalized Ramsey numbers through adiabatic quantum optimization

abstract:
  Ramsey theory is an active research area in combinatorics whose central theme
is the emergence of order in large disordered structures, with Ramsey numbers
marking the threshold at which this order first appears. For generalized Ramsey
numbers $r(G,H)$, the emergent order is characterized by graphs $G$ and $H$. In
this paper we: (i) present a quantum algorithm for computing generalized Ramsey
numbers by reformulating the computation as a combinatorial optimization
problem which is solved using adiabatic quantum optimization; and (ii)
determine the Ramsey numbers $r(\mathcal{T}_{m},\mathcal{T}_{n})$ for trees of
order $m,n = 6,7,8$, most of which were previously unknown.


title:
$\psi(2S)$ and $\Upsilon(3S)$ hadroproduction in the parton Reggeization
  approach: Yield, polarization, and the role of fragmentation

abstract:
  The hadroproduction of the radially excited heavy-quarkonium states
$\psi(2S)$ and $\Upsilon(3S)$ at high energies is studied in the parton
reggeization approach and the factorization formalism of nonrelativistic QCD at
lowest order in the strong-coupling constant $\alpha_s$ and the relative
heavy-quark velocity $v$. A satisfactory description of the $\psi(2S)$
transverse-momentum ($p_T$) distributions measured by ATLAS, CMS, and LHCb at
center-of-mass energy $\sqrt{S}=7$ TeV is obtained using the color-octet
long-distance matrix elements (LDMEs) extracted from CDF data at
$\sqrt{S}=1.96$ TeV. The importance of the fragmentation mechanism and the
scale evolution of the fragmentation functions in the upper $p_T$ range, beyond
30 GeV, is demonstrated. The $\Upsilon(3S)$ $p_T$ distributions measured by CDF
at $\sqrt{S}=1.8$ TeV and by LHCb at $\sqrt{S}=7$ TeV and forward rapidities
are well described using LDMEs fitted to ATLAS data at $\sqrt{S}=7$ TeV.
Comparisons of polarization measurements by CDF and CMS at large $p_T$ values
with our predictions consolidate the familiar problem in the $\psi(2S)$ case,
but yield reasonable agreement in the $\Upsilon(3S)$ case.


title:
The algebraic properties of the space- and time-dependent one-factor
  model of commodities

abstract:
  We consider the one-factor model of commodities for which the parameters of
the model depend upon the stock price or on the time. For that model we study
the existence of group-invariant transformations. When the parameters are
constant, the one-factor model is maximally symmetric. That also holds for the
time-dependent problem. However, in the case for which the parameters depend
upon the stock price (space) the one-factor model looses the group invariants.
For specific functional forms of the parameters the model admits other possible
Lie algebras. In each case we determine the conditions which the parameters
should satisfy in order for the equation to admit Lie point symmetries. Some
applications are given and we show which should be the precise relation amongst
the parameters of the model in order for the equation to be maximally
symmetric. Finally we discuss some modifications of the initial conditions in
the case of the space-dependent model. We do that by using geometric
techniques.


title: Implementing graph grammars for intelligence analysis in OCaml

abstract:
  We report on implementing graph grammars for intelligence analysis in OCaml.
Graph grammars are represented as elements of an algebraic data type in OCaml.
In addition to algebraic data types, we use other concepts from functional
programming languages to implement features of graph grammars. We use type
checking to perform graph pattern matching. Graph transformations are defined
as implicit coercions derived from structural subtyping proofs, subset types,
lambda abstractions, and analytics. An analytic is a general-purpose OCaml
function whose output is required to match a graph pattern described by an
element of an algebraic data type. By using a strongly-typed language for
representing graphs, we can ensure graphs produced from a graph transformation
will match a specific schema. This is a high priority requirement for
intelligence analysis.


title:
Classification of finite irreducible conformal modules over some Lie
  conformal algebras related to the Virasoro conformal algebra

abstract:
  In this paper, we classify all finite irreducible conformal modules over a
class of Lie conformal algebras $\mathcal{W}(b)$ with $b\in\mathbb{C}$ related
to the Virasoro conformal algebra. Explicitly, any finite irreducible conformal
module over $\mathcal{W}(b)$ is proved to be isomorphic to
$M_{\Delta,\alpha,\beta}$ with $\Delta\neq 0$ or $\beta\neq 0$ if $b=0$, or
$M_{\Delta,\alpha}$ with $\Delta\neq 0$ if $b\neq0$. As a byproduct, all finite
irreducible conformal modules over the Heisenberg-Virasoro conformal algebra
and the Lie conformal algebra of $\mathcal{W}(2,2)$-type are classified.
Finally, the same thing is done for the Schr\"odinger-Virasoro conformal
algebra.


title:
Preequilibrium particle emissions and in-medium effects on the pion
  production in heavy-ion collisions

abstract:
  Within the framework of the Lanzhou quantum molecular dynamics (LQMD)
transport model, pion dynamics in heavy-ion collisions near threshold energies
and the emission of preequilibrium particles (nucleons and light complex
fragments) have been investigated. A density, momentum and isospin dependent
pion-nucleon potential based on the $\Delta$-hole model is implemented in the
transport approach, which slightly leads to the increase of the
$\pi^{-}/\pi^{+}$ ratio, but reduces the total pion yields. It is found that a
bump structure of the $\pi^{-}/\pi^{+}$ ratio in the kinetic energy spectra
appears at the pion energy close to the $\Delta$(1232) resonance region. The
yield ratios of neutrons to protons from the squeeze-out particles
perpendicular to the reaction plane are sensitive to the stiffness of nuclear
symmetry energy, in particular at the high-momentum (kinetic energy) tails.


title:
Note on integrability of certain homogeneous Hamiltonian systems in 2D
  constant curvature spaces

abstract:
  We formulate the necessary conditions for the integrability of a certain
family of Hamiltonian systems defined in the constant curvature two-dimensional
spaces. Proposed form of potential can be considered as a counterpart of a
homogeneous potential in flat spaces. Thanks to this property Hamilton
equations admit, in a general case, a particular solution. Using this solution
we derive necessary integrability conditions investigating differential Galois
group of variational equations.


title: Solar illumination control of ionospheric outflow above polar cap arcs

abstract:
  We measure the flux density, composition, and energy of outflowing ions above
the polar cap, accelerated by quasi-static electric fields parallel to the
magnetic field and associated with polar cap arcs, using Cluster. Mapping the
spacecraft position to its ionospheric foot point, we analyze the dependence of
these parameters on the solar zenith angle (SZA). We find a clear transition at
SZA between We find a clear transition at SZA between $\sim$94$^{\circ}$ and
$\sim$107$^{\circ}$, with the O$^{+}$ flux higher above the sunlit ionosphere.
This dependence on the illumination of the local ionosphere indicates that
significant O$^{+}$ upflow occurs locally above the polar ionosphere. The same
is found for H$^{+}$, but to a lesser extent. This effect can result in a
seasonal variation of the total ion upflow from the polar ionosphere.
Furthermore, we show that low-magnitude field-aligned potential drops are
preferentially observed above the sunlit ionosphere, suggesting a feedback
effect of ionospheric conductivity.


title:
Crystal Structure Manipulation of the Exchange Bias in an
  Antiferromagnetic Film

abstract:
  Exchange bias is one of the most extensively studied phenomena in magnetism,
since it exerts a unidirectional anisotropy to a ferromagnet (FM) when coupled
to an antiferromagnet (AFM) and the control of the exchange bias is therefore
very important for technological applications, such as magnetic random access
memory and giant magnetoresistance sensors. In this letter, we report the
crystal structure manipulation of the exchange bias in epitaxial hcp Cr2O3
films. By epitaxially growing twined (10-10) oriented Cr2O3 thin films, of
which the c axis and spins of the Cr atoms lie in the film plane, we
demonstrate that the exchange bias between Cr2O3 and an adjacent permalloy
layer is tuned to in-plane from out-of-plane that has been observed in (0001)
oriented Cr2O3 films. This is owing to the collinear exchange coupling between
the spins of the Cr atoms and the adjacent FM layer. Such a highly anisotropic
exchange bias phenomenon is not possible in polycrystalline films.


title: Magnetic mapping of defects in type-II superconductors

abstract:
  Recently it was discovered that the non-uniform Meissner current flowing
around the pinning sites in the type-II superconductor induces the
unconventional vortex-antivortex pairs with the non-quantized magnetic flux
[J.-Y. Ge, et al., Nat. Commun. 6, 6573 (2015)]. Here we provide the theory of
this phenomenon showing that the vortex-like structures originate from the
perturbation of the current streamlines by the non-superconducting defect,
which results in the generation of the localized magnetic field. The position
and the shape of such vortex dipoles are shown to be very sensitive to the
defect form. Thus, applying the external magnetic field or current to the
superconductor and using, e.g., the high-resolution scanning Hall microscope to
measure the stray magnetic field one can plot the map containing the
information about the position of the defects and their shape.


title: Regularity of Stochastic Kinetic Equations

abstract:
  We consider regularity properties of stochastic kinetic equations with
multiplicative noise and drift term which belongs to a space of mixed
regularity ($L^p$-regularity in the velocity-variable and Sobolev regularity in
the space-variable). We prove that, in contrast with the deterministic case,
the SPDE admits a unique weakly differentiable solution which preserves a
certain degree of Sobolev regularity of the initial condition without
developing discontinuities. To prove the result we also study the related
degenerate Kolmogorov equation in Bessel-Sobolev spaces and construct a
suitable stochastic flow.


title:
Time-dependent Mott transition in the periodic Anderson model with
  nonlocal hybridization

abstract:
  The time-dependent Mott transition in a periodic Anderson model with
off-site, nearest-neighbor hybridization is studied within the framework of
nonequilibrium self-energy functional theory. Using the two-site
dynamical-impurity approximation, we compute the real-time dynamics of the
optimal variational parameter and of different observables initiated by sudden
quenches of the Hubbard-U and identify the critical interaction. The
time-dependent transition is orbital selective, i.e., in the final state,
reached in the long-time limit after the quench to the critical interaction,
the Mott gap opens in the spectral function of the localized orbitals only. We
discuss the dependence of the critical interaction and of the final-state
effective temperature on the hybridization strength and point out the various
similarities between the nonequilibrium and the equilibrium Mott transition. It
is shown that these can also be smoothly connected to each other by increasing
the duration of a U-ramp from a sudden quench to a quasi-static process. The
physics found for the model with off-site hybridization is compared with the
dynamical Mott transition in the single-orbital Hubbard model and with the
dynamical crossover found for the real-time dynamics of the conventional
Anderson lattice with on-site hybridization.


title: Exact Electromagnetic Casimir Energy of a Disk Opposite a Plane

abstract:
  Building on work of Meixner [J. Meixner, Z. Naturforschung 3a, 506 (1948)],
we show how to compute the exact scattering amplitude (or $T$-matrix) for
electromagnetic scattering from a perfectly conducting disk. This calculation
is a rare example of a non-diagonal $T$-matrix that can nonetheless be obtained
in a semi-analytic form. We then use this result to compute the electromagnetic
Casimir interaction energy for a disk opposite a plane, for arbitrary
orientation angle of the disk, for separations greater than the disk radius. We
find that the proximity force approximation (PFA) significantly overestimates
the Casimir energy, both in the case of the ordinary PFA, which applies when
the disk is parallel to the plane, and the "edge PFA," which applies when the
disk is perpendicular to the plane.


title: Temporal flows in Temporal networks

abstract:
  We introduce temporal flows on temporal networks, i.e., networks the links of
which exist only at certain moments of time. Such networks are ephemeral in the
sense that no link exists after some time. Our flow model is new and differs
from the "flows over time" model, also called "dynamic flows" in the
literature. We show that the problem of finding the maximum amount of flow that
can pass from a source vertex s to a sink vertex t up to a given time is
solvable in Polynomial time, even when node buffers are bounded. We then
examine mainly the case of unbounded node buffers. We provide a simplified
static Time-Extended network (STEG), which is of polynomial size to the input
and whose static flow rates are equivalent to the respective temporal flow of
the temporal network, using STEG, we prove that the maximum temporal flow is
equal to the minimum temporal s-t cut. We further show that temporal flows can
always be decomposed into flows, each of which moves only through a journey,
i.e., a directed path whose successive edges have strictly increasing moments
of existence. We partially characterise networks with random edge
availabilities that tend to eliminate the s-t temporal flow. We then consider
mixed temporal networks, which have some edges with specified availabilities
and some edges with random availabilities, we show that it is #P-hard to
compute the tails and expectations of the maximum temporal flow (which is now a
random variable) in a mixed temporal network.


title: Correlation Between Sunspot Number and ca II K Emission Index

abstract:
  Long-term synoptic observations in the resonance line of Ca II K constitute a
fundamental database for a variety of retrospective analyses of the state of
the solar magnetism. Synoptic Ca II K observations began in late 1904 at the
Kodaikanal Observatory, in India. In early 1970s, the National Solar
Observatory (NSO) at Sacramento Peak (USA) started a new program of daily
Sun-as-a-star observations in the Ca II K line. Today the NSO is continuing
these observations through its Synoptic Optical Long-term Investigations of the
Sun (SOLIS) facility. These different data sets can be combined into a single
disk-integrated Ca II K index time series that describes the average properties
of the chromospheric emission over several solar cycles. We present such a Ca
II K composite and discuss its correlation with the new entirely revised
sunspot number data series. For this preliminary investigation, the scaling
factor between pairs of time series was determined assuming a simple linear
model for the relationship between the monthly mean values during the duration
of overlapping observations.


title:
Extraction of clinical information from the non-invasive fetal
  electrocardiogram

abstract:
  Estimation of the fetal heart rate (FHR) has gained interest in the last
century, low heart rate variability has been studied to identify intrauterine
growth restricted fetuses (prepartum), and abnormal FHR patterns have been
associated with fetal distress during delivery (intrapartum). Several
monitoring techniques have been proposed for FHR estimation, including
auscultation and Doppler ultrasound. This thesis focuses on the extraction of
the non-invasive fetal electrocardiogram (NI-FECG) recorded from a limited set
of abdominal sensors. The main challenge with NI-FECG extraction techniques is
the low signal-to-noise ratio of the FECG signal on the abdominal mixture
signal which consists of a dominant maternal ECG component, FECG and noise.
However the NI-FECG offers many advantages over the alternative fetal
monitoring techniques, the most important one being the opportunity to enable
morphological analysis of the FECG which is vital for determining whether an
observed FHR event is normal or pathological. In order to advance the field of
NI-FECG signal processing, the development of standardised public databases and
benchmarking of a number of published and novel algorithms was necessary.


title: One-parameter class of uncertainty relations based on entropy power

abstract:
  We use the concept of entropy power to derive a new one-parameter class of
information-theoretic uncertainty relations for pairs of conjugate observables
in an infinite-dimensional Hilbert space. This class constitutes an infinite
tower of higher-order statistics uncertainty relations, which allows one in
principle to determine the shape of the underlying information-distribution
function by measuring the relevant entropy powers. We illustrate the capability
of the new class by discussing two examples: superpositions of vacuum and
squeezed states and the Cauchy-type heavy-tailed wave function.


title:
Early Advanced LIGO binary neutron-star sky localization and parameter
  estimation

abstract:
  2015 will see the first observations of Advanced LIGO and the start of the
gravitational-wave (GW) advanced-detector era. One of the most promising
sources for ground-based GW detectors are binary neutron-star (BNS)
coalescences. In order to use any detections for astrophysics, we must
understand the capabilities of our parameter-estimation analysis. By simulating
the GWs from an astrophysically motivated population of BNSs, we examine the
accuracy of parameter inferences in the early advanced-detector era. We find
that sky location, which is important for electromagnetic follow-up, can be
determined rapidly (~5 s), but that sky areas may be hundreds of square
degrees. The degeneracy between component mass and spin means there is
significant uncertainty for measurements of the individual masses and spins;
however, the chirp mass is well measured (typically better than 0.1%).


title:
The quotient of a Kauffman bracket skein algebra by the square of an
  augmentation ideal

abstract:
  We give an explicit basis $\mathcal{B}$ of the quotient of the Kauffman
bracket skein algebra $\mathcal{S} (\Sigma)$ on a surface $\Sigma$ by the
square of an augmentation ideal. As an application, it induces two kinds of
finite type invariants of links in a handle body in the sense of Le. Moreover,
we construct an embedding of the mapping class group of a compact connected
surface of genus $0$ into the Kauffman bracket skein algebra on the surface
completed with respect to a filtration coming from the augmentation ideal.


title:
Optomechanical Self-Oscillations in an Anharmonic Potential: Engineering
  a Nonclassical Steady State

abstract:
  We study self-oscillations of an optomechanical system, where coherent
mechanical oscillations are induced by a driven optical or microwave cavity,
for the case of an anharmonic mechanical oscillator potential. A semiclassical
analytical model is developed to characterize the limit cycle for large
mechanical amplitudes corresponding to a weak nonlinearity. As a result, we
predict conditions to achieve subpoissonian phonon statistics in the steady
state, indicating classically forbidden behavior. We compare with numerical
simulations and find very good agreement. Our model is quite general and can be
applied to other physical systems such as trapped ions or superconducting
circuits.


title:
Highlights from "The Ramanujan Property for Simplicial Complexes"
  [arXiv:1605.02664]

abstract:
  This paper brings the main definitions and results from "The Ramanujan
Property for Simplicial Complexes" [arXiv:1605.02664]. No proofs are given.
  Given a simplicial complex $\mathcal{X}$ and a group $G$ acting on
$\mathcal{X}$, we define Ramanujan quotients of $\mathcal{X}$. For $G$ and
$\mathcal{X}$ suitably chosen this recovers Ramanujan $k$-regular graphs and
Ramanujan complexes in the sense of Lubotzky, Samuels and Vishne. Deep results
in automorphic representations are used to give new examples of Ramanujan
quotients when $\mathcal{X}$ is the affine building of an inner form of
$\mathbf{GL}_n$ over a local field of positive characteristic.


title:
Spontaneous magnetization of quantum $XY$ spin model in joint presence
  of quenched and annealed disorder

abstract:
  We investigate equilibrium statistical properties of the quantum XY spin-1/2
model in an external magnetic field when the interaction and field parts are
subjected to quenched or/and annealed disorder. The randomness present in the
system are termed annealed or quenched depending on the relation between two
different time scales - the time scale associated with the equilibriation of
the randomness and the time of observation. Within a mean-field framework, we
study the effects of disorders on spontaneous magnetization, both by
perturbative and numerical techniques. Our primary interest is to understand
the differences between quenched and annealed cases, and also to investigate
the interplay when both of them are present in a system. We observe in
particular that when interaction and field terms are respectively quenched and
annealed, critical temperature for the system to magnetize in the direction
parallel to the applied field does not depend on any of the disorders. Further,
an annealed disordered interaction neither affects the magnetizations nor the
critical temperatures. We carry out a comparative study of the different
combinations of the disorders in the interaction and field terms, and point out
their generic features.


title: Learning under Distributed Weak Supervision

abstract:
  The availability of training data for supervision is a frequently encountered
bottleneck of medical image analysis methods. While typically established by a
clinical expert rater, the increase in acquired imaging data renders
traditional pixel-wise segmentations less feasible. In this paper, we examine
the use of a crowdsourcing platform for the distribution of super-pixel weak
annotation tasks and collect such annotations from a crowd of non-expert
raters. The crowd annotations are subsequently used for training a fully
convolutional neural network to address the problem of fetal brain segmentation
in T2-weighted MR images. Using this approach we report encouraging results
compared to highly targeted, fully supervised methods and potentially address a
frequent problem impeding image analysis research.


title:
Canonical superenergy and angular supermomentum complexes in general
  relativity and some of their applications

abstract:
  Many years ago we have introduced into general relativity, {\bf GR}, the
canonical superenergy tensors, $S_i^{~k}$, and the canonical angular
supermomentum tensors, $S^{ikl}=(-)S^{kil}$, matter and gravitation. We have
obtained these tensors by special averaging of the differences of the canonical
energy-momentum and canonical angular momentum. The averaging was performed in
Riemann normal coordinates, {\bf RNC(P)}; {\bf P} is beginning of these
coordinates. About four years ago we have observed that these tensors can also
be obtained in other, simpler way, by using the canonical superenergy and
angular super momentum complexes, $_K S_i^{~k}$, and, $_K S~^{ikl}=(-)_K
S^{kil}$, respectively. Such complexes can be introduced into {\bf GR} in a
natural way starting from canonical energy-momentum and angular momentum
complexes.
  In this paper, at first, we define the canonical superenergy and angular
supermomentum complexes in {\bf GR} and then, we apply them to analyze of a
closed system, {\bf CS}, Trautman's radiative spacetimes, {\bf TRS}, and
Friedman universes, {\bf FU}. Finally, we compare these complexes and the
results obtained with their help with the canonical superenergy and angular
supermomentum tensors and results obtained with them in past. In Appendix, for
convenience, we summarize our old approach to canonical superenergy and angular
supermomentum tensors.


title:
Acquisition of Visual Features Through Probabilistic
  Spike-Timing-Dependent Plasticity

abstract:
  The final version of this paper has been published in IEEEXplore available at
http://ieeexplore.ieee.org/document/7727213. Please cite this paper as:
Amirhossein Tavanaei, Timothee Masquelier, and Anthony Maida, Acquisition of
visual features through probabilistic spike-timing-dependent plasticity. IEEE
International Joint Conference on Neural Networks. pp. 307-314, IJCNN 2016.
  This paper explores modifications to a feedforward five-layer spiking
convolutional network (SCN) of the ventral visual stream [Masquelier, T.,
Thorpe, S., Unsupervised learning of visual features through spike timing
dependent plasticity. PLoS Computational Biology, 3(2), 247-257]. The original
model showed that a spike-timing-dependent plasticity (STDP) learning algorithm
embedded in an appropriately selected SCN could perform unsupervised feature
discovery. The discovered features where interpretable and could effectively be
used to perform rapid binary decisions in a classifier. In order to study the
robustness of the previous results, the present research examines the effects
of modifying some of the components of the original model. For improved
biological realism, we replace the original non-leaky integrate-and-fire
neurons with Izhikevich-like neurons. We also replace the original STDP rule
with a novel rule that has a probabilistic interpretation. The probabilistic
STDP slightly but significantly improves the performance for both types of
model neurons. Use of the Izhikevich-like neuron was not found to improve
performance although performance was still comparable to the IF neuron. This
shows that the model is robust enough to handle more biologically realistic
neurons. We also conclude that the underlying reasons for stable performance in
the model are preserved despite the overt changes to the explicit components of
the model.


title:
A combined transmission spectrum of the Earth-sized exoplanets
  TRAPPIST-1 b and c

abstract:
  Three Earth-sized exoplanets were recently discovered close to the habitable
zone of the nearby ultracool dwarf star TRAPPIST-1. The nature of these planets
has yet to be determined, since their masses remain unmeasured and no
observational constraint is available for the planetary population surrounding
ultracool dwarfs, of which the TRAPPIST-1 planets are the first transiting
example. Theoretical predictions span the entire atmospheric range from
depleted to extended hydrogen-dominated atmospheres. Here, we report a
space-based measurement of the combined transmission spectrum of the two inner
planets made possible by a favorable alignment resulting in their simultaneous
transits on 04 May 2016. The lack of features in the combined spectrum rules
out cloud-free hydrogen-dominated atmospheres for each planet at 10-$\sigma$
levels; TRAPPIST-1 b and c are hence unlikely to harbor an extended gas
envelope as they lie in a region of parameter space where high-altitude
cloud/haze formation is not expected to be significant for hydrogen-dominated
atmospheres. Many denser atmospheres remain consistent with the featureless
transmission spectrum---from a cloud-free water vapour atmosphere to a
Venus-like atmosphere.


title:
A finite volume scheme for boundary-driven convection-diffusion
  equations with relative entropy structure

abstract:
  We propose a finite volume scheme for a class of nonlinear parabolic
equations endowed with non-homogeneous Dirichlet boundary conditions and which
admit relative en-tropy functionals. For this kind of models including porous
media equations, Fokker-Planck equations for plasma physics or dumbbell models
for polymer flows, it has been proved that the transient solution converges to
a steady-state when time goes to infinity. The present scheme is built from a
discretization of the steady equation and preserves steady-states and natural
Lyapunov functionals which provide a satisfying long-time behavior. After
proving well-posedness, stability, exponential return to equilibrium and
convergence, we present several numerical results which confirm the accuracy
and underline the efficiency to preserve large-time asymptotic.


title:
Direct Measure of Radiative and Dynamical Properties of an Exoplanet
  Atmosphere

abstract:
  Two decades after the discovery of 51 Peg b, the formation processes and
atmospheres of short-period gas giants remain poorly understood. Observations
of eccentric systems provide key insights on those topics as they can
illuminate how a planet's atmosphere responds to changes in incident flux. We
report here the analysis of multi-day multi-channel photometry of the eccentric
(e~ 0.93) hot Jupiter HD 80606 b obtained with the Spitzer Space Telescope. The
planet's extreme eccentricity combined with the long coverage and exquisite
precision of new periastron-passage observations allow us to break the
degeneracy between the radiative and dynamical timescales of HD 80606 b's
atmosphere and constrain its global thermal response. Our analysis reveals that
the atmospheric layers probed heat rapidly (~4 hr radiative timescale) from
$\lt$500 to 1400 K as they absorb ~ 20% of the incoming stellar flux during the
periastron passage, while the planet's rotation period is 93$\pm_{35}^{85}$ hr,
which exceeds the predicted pseudo-synchronous period (40 hr).


title: Set-Theoretic Types for Polymorphic Variants

abstract:
  Polymorphic variants are a useful feature of the OCaml language whose current
definition and implementation rely on kinding constraints to simulate a
subtyping relation via unification. This yields an awkward formalization and
results in a type system whose behaviour is in some cases unintuitive and/or
unduly restrictive. In this work, we present an alternative formalization of
poly-morphic variants, based on set-theoretic types and subtyping, that yields
a cleaner and more streamlined system. Our formalization is more expressive
than the current one (it types more programs while preserving type safety), it
can internalize some meta-theoretic properties, and it removes some
pathological cases of the current implementation resulting in a more intuitive
and, thus, predictable type system. More generally, this work shows how to add
full-fledged union types to functional languages of the ML family that usually
rely on the Hindley-Milner type system. As an aside, our system also improves
the theory of semantic subtyping, notably by proving completeness for the type
reconstruction algorithm.


title: Packing Coloring of Undirected and Oriented Generalized Theta Graphs

abstract:
  The packing chromatic number $\chi$ $\rho$ (G) of an undirected (resp.
oriented) graph G is the smallest integer k such that its set of vertices V (G)
can be partitioned into k disjoint subsets V 1,..., V k, in such a way that
every two distinct vertices in V i are at distance (resp. directed distance)
greater than i in G for every i, 1 $\le$ i $\le$ k. The generalized theta graph
$\Theta$ {\ell} 1,...,{\ell}p consists in two end-vertices joined by p $\ge$ 2
internally vertex-disjoint paths with respective lengths 1 $\le$ {\ell} 1 $\le$
. . . $\le$ {\ell} p. We prove that the packing chromatic number of any
undirected generalized theta graph lies between 3 and max{5, n 3 + 2}, where n
3 = |{i / 1 $\le$ i $\le$ p, {\ell} i = 3}|, and that both these bounds are
tight. We then characterize undirected generalized theta graphs with packing
chromatic number k for every k $\ge$ 3. We also prove that the packing
chromatic number of any oriented generalized theta graph lies between 2 and 5
and that both these bounds are tight.


title:
Multiplicity of Galactic Cepheids from long-baseline interferometry~III.
  Sub-percent limits on the relative brightness of a close companion of
  $\delta$~Cephei

abstract:
  We report new CHARA/MIRC interferometric observations of the Cepheid
archetype $\delta$ Cep, which aimed at detecting the newly discovered
spectroscopic companion. We reached a maximum dynamic range $\Delta H $ = 6.4,
5.8, and 5.2 mag, respectively within the relative distance to the Cepheid $r <
25$ mas, $25 < r < 50$ mas and $50 < r < 100$ mas. Our observations did not
show strong evidence of a companion. We have a marginal detection at $3\sigma$
with a flux ratio of 0.21\%, but nothing convincing as we found other possible
probable locations. We ruled out the presence of companion with a spectral type
earlier than F0V, A1V and B9V, respectively for the previously cited ranges
$r$. From our estimated sensitivity limits and the Cepheid light curve, we
derived lower-limit magnitudes in the $H$ band for this possible companion to
be $H_\mathrm{comp} > 9.15, 8.31$ and 7.77 mag, respectively for $r < 25$ mas,
$25 < r < 50$ mas and $50 < r < 100$ mas. We also found that to be consistent
with the predicted orbital period, the companion has to be located at a
projected separation $< 24$ mas with a spectral type later than a F0V star.


title: A flipped 331 model

abstract:
  Models based on the extended $SU(3)_{C}\times SU(3)_{L}\times U(1)_{X}$ (331)
gauge group usually follow a common pattern: two families of left-handed quarks
are placed in anti-triplet representations of the $SU(3)_{L}$ group; the
remaining quark family, as well as the left-handed leptons, are assigned to
triplets (or vice-versa). In this work we present a flipped 331 model where
this scheme is reversed: all three quarks families are in the same
representation and it is the lepton families which are discriminated by the
gauge symmetry. We discuss fermion masses and mixing, as well as $Z'$
interactions, in a minimal model implementing this idea.


title: Detector-decoy high-dimensional quantum key distribution

abstract:
  The decoy-state high-dimensional quantum key distribution provides a
practical secure way to share more private information with high
photon-information efficiency. In this paper, based on detector-decoy method,
we propose a detector-decoy high-dimensional quantum key distribution protocol.
Employing threshold detectors and a variable attenuator, we can estimate
single-photon fraction of postselected events and Eves Holevo information under
the Gaussian collective attack with much simpler operations in practical
implementation. By numerical evaluation, we show that without varying source
intensity and optimizing decoy-state intensity, our protocol could perform much
better than one-decoy-state protocol and as well as the two-decoy-state
protocol. Specially, when the detector efficiency is lower, the advantage of
the detector-decoy method becomes more prominent.


title: Property-driven State-Space Coarsening for Continuous Time Markov Chains

abstract:
  Dynamical systems with large state-spaces are often expensive to thoroughly
explore experimentally. Coarse-graining methods aim to define simpler systems
which are more amenable to analysis and exploration; most current methods,
however, focus on a priori state aggregation based on similarities in
transition rates, which is not necessarily reflected in similar behaviours at
the level of trajectories. We propose a way to coarsen the state-space of a
system which optimally preserves the satisfaction of a set of logical
specifications about the system's trajectories. Our approach is based on
Gaussian Process emulation and Multi-Dimensional Scaling, a dimensionality
reduction technique which optimally preserves distances in non-Euclidean
spaces. We show how to obtain low-dimensional visualisations of the system's
state-space from the perspective of properties' satisfaction, and how to define
macro-states which behave coherently with respect to the specifications. Our
approach is illustrated on a non-trivial running example, showing promising
performance and high computational efficiency.


title: Ancient Ricci Flow Solutions on Bundles

abstract:
  We generalize the circle bundle examples of ancient solutions of the Ricci
flow discovered by Bakas, Kong, and Ni to a class of principal torus bundles
over an arbitrary finite product of Fano K\"ahler-Einstein manifolds studied by
Wang and Ziller in the context of Einstein geometry. As a result, continuous
families of $\kappa$-collapsed and $\kappa$-noncollapsed ancient solutions of
type I are obtained on circle bundles for all odd dimensions $\geq 7$. In
dimension $7$ such examples moreover exist on pairs of homeomorphic but not
diffeomorphic manifolds. Continuous families of $\kappa$-collapsed ancient
solutions of type I are also obtained on torus bundles for all dimensions $\geq
8$.


title: ECMdd: Evidential c-medoids clustering with multiple prototypes

abstract:
  In this work, a new prototype-based clustering method named Evidential
C-Medoids (ECMdd), which belongs to the family of medoid-based clustering for
proximity data, is proposed as an extension of Fuzzy C-Medoids (FCMdd) on the
theoretical framework of belief functions. In the application of FCMdd and
original ECMdd, a single medoid (prototype), which is supposed to belong to the
object set, is utilized to represent one class. For the sake of clarity, this
kind of ECMdd using a single medoid is denoted by sECMdd. In real clustering
applications, using only one pattern to capture or interpret a class may not
adequately model different types of group structure and hence limits the
clustering performance. In order to address this problem, a variation of ECMdd
using multiple weighted medoids, denoted by wECMdd, is presented. Unlike
sECMdd, in wECMdd objects in each cluster carry various weights describing
their degree of representativeness for that class. This mechanism enables each
class to be represented by more than one object. Experimental results in
synthetic and real data sets clearly demonstrate the superiority of sECMdd and
wECMdd. Moreover, the clustering results by wECMdd can provide richer
information for the inner structure of the detected classes with the help of
prototype weights.


title: The Torelli group and the Kauffman bracket skein module

abstract:
  We introduce an embedding of the Torelli group of a compact connected
oriented surface with non-empty connected boundary into the completed Kauffman
bracket skein algebra of the surface, which gives a new construction of the
first Johnson homomorphism.


title: Matrix models for noncommutative algebraic manifolds

abstract:
  We discuss the notion of matrix model, $\pi:C(X)\to M_K(C(T))$, for algebraic
submanifolds of the free complex sphere, $X\subset S^{N-1}_{\mathbb C,+}$. When
$K\in\mathbb N$ is fixed there is a universal such model, which factorizes as
$\pi:C(X)\to C(X^{(K)})\subset M_K(C(T))$. We have $X^{(1)}=X_{class}$ and,
under a mild assumption, inclusions $X^{(1)}\subset X^{(2)}\subset
X^{(3)}\subset\ldots\subset X$. Our main results concern
$X^{(2)},X^{(3)},X^{(4)},\ldots$, their relation with various half-classical
versions of $X$, and lead to the construction of families of higher
half-liberations of the complex spheres and of the unitary groups, all having
faithful matrix models.


title: The belief noisy-or model applied to network reliability analysis

abstract:
  One difficulty faced in knowledge engineering for Bayesian Network (BN) is
the quan-tification step where the Conditional Probability Tables (CPTs) are
determined. The number of parameters included in CPTs increases exponentially
with the number of parent variables. The most common solution is the
application of the so-called canonical gates. The Noisy-OR (NOR) gate, which
takes advantage of the independence of causal interactions, provides a
logarithmic reduction of the number of parameters required to specify a CPT. In
this paper, an extension of NOR model based on the theory of belief functions,
named Belief Noisy-OR (BNOR), is proposed. BNOR is capable of dealing with both
aleatory and epistemic uncertainty of the network. Compared with NOR, more rich
information which is of great value for making decisions can be got when the
available knowledge is uncertain. Specially, when there is no epistemic
uncertainty, BNOR degrades into NOR. Additionally, different structures of BNOR
are presented in this paper in order to meet various needs of engineers. The
application of BNOR model on the reliability evaluation problem of networked
systems demonstrates its effectiveness.


title: Nonparametric adaptive estimation for grouped data

abstract:
  The aim of this paper is to estimate the density f of a random variable X
when one has access to independent observations of the sum of K $\ge$ 2
independent copies of X. We provide a constructive estimator based on a
suitable definition of the logarithm of the empirical characteristic
function.We propose a new strategy for the data driven choice of the cut-off
parameter. The adaptive estimator is proven to be minimax-optimal up to some
logarithmic loss. A numerical study illustrates the performances of the method.
Moreover, we discuss the fact that the definition of the estimator applies in a
wider context than the one considered here.


title:
Feasibility studies of time-like proton electromagnetic form factors at
  PANDA at FAIR

abstract:
  Simulation results for future measurements of electromagnetic proton form
factors at \PANDA (FAIR) within the PandaRoot software framework are reported.
The statistical precision with which the proton form factors can be determined
is estimated. The signal channel $\bar p p \to e^+ e^-$ is studied on the basis
of two different but consistent procedures. The suppression of the main
background channel, $\textit{i.e.}$ $\bar p p \to \pi^+ \pi^-$, is studied.
Furthermore, the background versus signal efficiency, statistical and
systematical uncertainties on the extracted proton form factors are evaluated
using two different procedures. The results are consistent with those of a
previous simulation study using an older, simplified framework. However, a
slightly better precision is achieved in the PandaRoot study in a large range
of momentum transfer, assuming the nominal beam conditions and detector
performance.


title: Correlators at large c without information loss

abstract:
  We study a simple class of correlators with two heavy and two light operators
both in the D1D5 CFT and in the dual AdS$_3 \times S^3 \times T^4$ description.
On the CFT side we focus on the free orbifold point and discuss how these
correlators decompose in terms of conformal blocks, showing that they are
determined by protected quantities. On the gravity side, the heavy states are
described by regular, asymptotically AdS$_3 \times S^3 \times T^4$ solutions
and the correlators are obtained by studying the wave equation in these
backgrounds. We find that the CFT and the gravity results agree and that, even
in the large central charge limit, these correlators do not have (Euclidean)
spurious singularities. We suggest that this is indeed a general feature of the
heavy-light correlators in unitary CFTs, which can be relevant for
understanding how information is encoded in black hole microstates.


title:
From Mechatronic Components to Industrial Automation Things - An IoT
  model for cyber-physical manufacturing systems

abstract:
  IoT is considered as one of the key enabling technologies for the fourth
industrial revolution, that is known as Industry 4.0. In this paper, we
consider the mechatronic component as the lowest level in the system
composition hierarchy that tightly integrates mechanics with the electronics
and software required to convert the mechanics to intelligent (smart) object
offering well defined services to its environment. For this mechatronic
component to be integrated in the IoT-based industrial automation environment,
a software layer is required on top of it to convert its conventional interface
to an IoT compliant one. This layer, that we call IoTwrapper, transforms the
conventional mechatronic component to an Industrial Automation Thing (IAT). The
IAT is the key element of an IoT model specifically developed in the context of
this work for the manufacturing domain. The model is compared to existing IoT
models and its main differences are discussed. A model-to-model transformer is
presented to automatically transform the legacy mechatronic component to an IAT
ready to be integrated in the IoT-based industrial automation environment. The
UML4IoT profile is used in the form of a Domain Specific Modeling Language to
automate this transformation. A prototype implementation of an Industrial
Automation Thing using C and the Contiki operating system demonstrates the
effectiveness of the proposed approach.


title: Enhanced four-wave mixing with nonlinear plasmonic metasurfaces

abstract:
  Plasmonic metasurfaces provide an effective way to increase the efficiency of
several nonlinear processes while maintaining nanoscale dimensions. In this
work, nonlinear metasurfaces based on film-coupled silver nanostripes loaded
with Kerr nonlinear material are proposed to achieve efficient four-wave mixing
(FWM). Highly localized plasmon resonances are formed in the nanogap between
the metallic film and nanostripes. The local electric field is dramatically
enhanced in this subwavelength nanoregion. These properties combined with the
relaxed phase matching condition due to the ultrathin area lead to a giant FWM
efficiency, which is enhanced by nineteen orders of magnitude compared to a
bare silver screen. In addition, efficient visible and low-THz sources can be
constructed based on the proposed nonlinear metasurfaces. The FWM generated
coherent wave has a directional radiation pattern and its output power is
relatively insensitive to the incident angles of the excitation sources. This
radiated power can be further enhanced by increasing the excitation power. The
dielectric nonlinear material placed in the nanogap is mainly responsible for
the ultrastrong FWM response. Compact and efficient wave mixers and optical
sources spanning different frequency ranges are envisioned to be designed based
on the proposed nonlinear metasurface designs.


title: Minimal excitations in the fractional quantum Hall regime

abstract:
  We study the minimal excitations of fractional quantum Hall edges, extending
the notion of levitons to interacting systems. Using both perturbative and
exact calculations, we show that they arise in response to a Lorentzian
potential with quantized flux. They carry an integer charge, thus involving
several Laughlin quasiparticles, and leave a Poissonian signature in a
Hanbury-Brown and Twiss partition noise measurement at low transparency. This
makes them readily accessible experimentally, ultimately offering the
opportunity to study real-time transport of Abelian and non-Abelian
excitations.


title: Concurrent Remote Entanglement with Quantum Error Correction

abstract:
  Remote entanglement of distant, non-interacting quantum entities is a key
primitive for quantum information processing. We present a new protocol to
remotely entangle two stationary qubits by first entangling them with
propagating ancilla qubits and then performing a joint two-qubit measurement on
the ancillas. Subsequently, single-qubit measurements are performed on each of
the ancillas. We describe two continuous variable implementations of the
protocol using propagating microwave modes. The first implementation uses
propagating Schr$\rm{\ddot{o}}$dinger cat-states as the flying ancilla qubits,
a joint-photon-number-modulo-2 measurement of the propagating modes for the
two-qubit measurement and homodyne detections as the final single-qubit
measurements. The presence of inefficiencies in realistic quantum systems limit
the success-rate of generating high fidelity Bell-states. This motivates us to
propose a second continuous variable implementation, where we use quantum error
correction to suppress the decoherence due to photon loss to first order. To
that end, we encode the ancilla qubits in superpositions of Schr\"odinger cat
states of a given photon-number-parity, use a joint-photon-number-modulo-4
measurement as the two-qubit measurement and homodyne detections as the final
single-qubit measurements. We demonstrate the resilience of our
quantum-error-correcting remote entanglement scheme to imperfections. Further,
we describe a modification of our error-correcting scheme by incorporating
additional individual photon-number-modulo-2 measurements of the ancilla modes
to improve the success-rate of generating high-fidelity Bell-states. Our
protocols can be straightforwardly implemented in state-of-the-art
superconducting circuit-QED systems.


title:
Competing electronic instabilities of extended Hubbard models on the
  honeycomb lattice: A functional Renormalization Group calculation with high
  wavevector resolution

abstract:
  We investigate the quantum many-body instabilities for electrons on the
honeycomb lattice at half-filling with extended interactions, motivated by a
description of graphene and related materials. We employ a recently developed
fermionic functional Renormalization Group scheme which allows for highly
resolved calculations of wavevector dependences in the low-energy effective
interactions. We encounter the expected anti-ferromagnetic spin density wave
for a dominant on-site repulsion between electrons, and charge order with
different modulations for dominant pure $n$-th nearest neighbor repulsive
interactions. Novel instabilities towards incommensurate charge density waves
take place when non-local density interactions among several bond distances are
included simultaneously. Moreover, for more realistic Coulomb potentials in
graphene including enough non-local terms there is a suppression of charge
order due to competition effects between the different charge ordering
tendencies, and if the on-site term fails to dominate, the semi-metallic state
is rendered stable. The possibility of a topological Mott insulator being the
favored tendency for dominating second nearest neighbor interactions is not
realized in our results with high momentum resolution.


title:
Electronic instabilities of the extended Hubbard model on the honeycomb
  lattice from functional renormalization

abstract:
  Interacting fermions on the half-filled honeycomb lattice with short-range
repulsions have been suggested to host a variety of interesting many-body
ground states, e.g., a topological Mott insulator. A number of recent studies
of the spinless case in terms of exact diagonalization, the infinite density
matrix renormalization group and the functional renormalization group, however,
indicate a suppression of the topological Mott insulating phase in the whole
range of interaction parameters. Here, we complement the previous studies by
investigating the quantum many-body instabilities of the physically relevant
case of spin-1/2 fermions with onsite, nearest-neighbor and
second-nearest-neighbor repulsion. To this end, we employ the multi-patch
functional renormalization group for correlated fermions with refined momentum
resolution observing the emergence of an antiferromagnetic spin-density wave
and a charge-density wave for dominating onsite and nearest-neighbor
repulsions, respectively. For dominating second-nearest neighbor interaction
our results favor an ordering tendency towards a charge-modulated ground state
over the topological Mott insulating state. The latter evades a stabilization
as the leading instability by the additional onsite interaction.


title: Superfluid hydrodynamics in the inner crust of neutron stars

abstract:
  The inner crust of neutron stars is supposed to be inhomogeneous and composed
of dense structures (clusters) that are immersed in a dilute gas of unbound
neutrons. Here we consider spherical clusters forming a BCC crystal and
cylindrical rods arranged in a hexagonal lattice. We study the relative motion
of these dense structures and the neutron gas using superfluid hydrodynamics.
Within this approach, which relies on the assumption that Cooper pairs are
small compared to the crystalline structures, we find that the entrainment of
neutrons by the clusters is very weak since neutrons of the gas can flow
through the clusters. Consequently, we obtain a low effective mass of the
clusters and a superfluid density that is even higher than the density of
unbound neutrons. Consequences for the constraints from glitch observations are
discussed.


title:
Long-Term Tracking of Corotating Density Structures using Heliospheric
  Imaging

abstract:
  The systematic monitoring of the solar wind in high-cadence and
high-resolution heliospheric images taken by the Solar-Terrestrial Relation
Observatory (STEREO) spacecraft permits the study of the spatial and temporal
evolution of variable solar wind flows from the Sun out to 1~AU, and beyond. As
part of the EU Framework 7 (FP7) Heliospheric Cataloguing, Analysis and
Techniques Service (HELCATS) project, we have generated a catalogue listing the
properties of 190 corotating structures well-observed in images taken by the
Heliospheric Imager instruments on-board STEREO-A. We present here one of very
few long-term analyses of solar wind structures advected by the background
solar wind. This analysis confirms that most of the corotating density
structures detected by the heliospheric imagers comprises a series of density
inhomogeneities advected by the slow solar wind that eventually become
entrained by stream interaction regions. We have derived the spatial-temporal
evolution of each of these corotating density structures by using a
well-established fitting technique. The mean radial propagation speed of the
corotating structures is found to be $311 \pm 31$ km~s$^{-1}$. We predicted the
arrival time of each corotating density structure at different probes. We show
that the speeds of the corotating density structures derived using our fitting
technique track well the long-term variation of the radial speed of the slow
solar wind during solar minimum years (2007--2008). Furthermore, we demonstrate
that these features originate near the coronal neutral line that eventually
becomes the heliospheric current sheet.


title:
Difference of Convex Functions Programming Applied to Control with
  Expert Data

abstract:
  This paper reports applications of Difference of Convex functions (DC)
programming to Learning from Demonstrations (LfD) and Reinforcement Learning
(RL) with expert data. This is made possible because the norm of the Optimal
Bellman Residual (OBR), which is at the heart of many RL and LfD algorithms, is
DC. Improvement in performance is demonstrated on two specific algorithms,
namely Reward-regularized Classification for Apprenticeship Learning (RCAL) and
Reinforcement Learning with Expert Demonstrations (RLED), through experiments
on generic Markov Decision Processes (MDP), called Garnets.