title:
Measuring the trilinear neutral Higgs boson couplings in the MSSM at
  $e^+ e^-$ colliders

abstract:
  We consider the measurement of the trilinear couplings of the neutral Higgs
bosons~($H^0, h^0$) in the minimal supersymmetric standard model~(MSSM) at a
high energy $e^+$ $e^-$ linear collider in the light of the discovery of a
Higgs boson at the CERN Large Hadron Collider~(LHC). We identify the state
observed at the LHC with the lightest CP-even Higgs boson of the MSSM. We
implement this constraint, as well as all the other relevant experimental
constraints, on the parameter space of the MSSM in order to study the
feasibility of measuring the trilinear couplings of the neutral Higgs bosons.
For the measurement of trilinear couplings, we consider the multiple Higgs
production processes. We delineate the regions of MSSM parameter space where
the trilinear couplings of the neutral Higgs bosons could be measured at a high
energy electron-positron collider.


title: A note about connectedness theorems a la Barth

abstract:
  We prove Barth-type connectedness results for low-codimension smooth
subvarieties with good numerical properties inside certain "easy" ambient
spaces (such as homogeneous varieties, or spherical varieties). The argument
employs some basics from the theory of cones of cycle classes, in particular
the notion of bigness of a cycle class.


title: On a multiplicative version of Bloch's conjecture

abstract:
  A theorem of Esnault, Srinivas and Viehweg asserts that if the Chow group of
0-cycles of a smooth complete complex variety decomposes, then the top-degree
coherent cohomology group decomposes similarly. In this note, we prove that (a
weak version of) the converse holds for varieties of dimension at most 5 that
have finite-dimensional motive and satisfy the Lefschetz standard conjecture.
The proof is based on Vial's construction of a refined Chow-Kunneth
decomposition for these varieties.


title: Some new examples of smash-nilpotent algebraic cycles

abstract:
  Voevodsky has conjectured that numerical equivalence and smash-equivalence
coincide for algebraic cycles on any smooth projective variety. Building on
work of Vial and Kahn-Sebastian, we give some new examples of varieties where
Voevodsky's conjecture is verified.


title: Ab-initio approach for gap plasmonics

abstract:
  Gap plasmonics deals with the properties of surface plasmons in the narrow
region between two metallic nanoparticles forming the gap. For sub-nanometer
gap distances electrons can tunnel between the nanoparticles leading to the
emergence of novel charge transfer plasmons. These are conveniently described
within the quantum corrected model by introducing an artificial material with a
tunnel conductivity inside the gap region. Here we develop a methodology for
computing such tunnel conductivities within the first-principles framework of
density functional theory, and apply our approach to a jellium model
representative for sodium. We show that the frequency dependence of the tunnel
conductivity at infrared and optical frequencies can be significantly more
complicated than previously thought.


title:
On Notions of Distortion and an Almost Minimum Spanning Tree with
  Constant Average Distortion

abstract:
  This paper makes two main contributions: The first is the construction of a
near-minimum spanning tree with constant average distortion. The second is a
general equivalence theorem relating two refined notions of distortion: scaling
distortion and prioritized distortion.
  Minimum Spanning Trees of weighted graphs are fundamental objects in numerous
applications. In particular in distributed networks, the minimum spanning tree
of the network is often used to route messages between network nodes.
Unfortunately, while being most efficient in the total cost of connecting all
nodes, minimum spanning trees fail miserably in the desired property of
approximately preserving distances between pairs. While known lower bounds
exclude the possibility of the worst case distortion of a tree being small, it
was shown in [ABN15] that there exists a spanning tree with constant average
distortion. Yet, the weight of such a tree may be significantly larger than
that of the MST. In this paper, we show that any weighted undirected graph
admits a {\em spanning tree} whose weight is at most $(1+\rho)$ times that of
the MST, providing {\em constant average distortion} $O(1/\rho)$. Our result
exhibits the best possible tradeoff of this type.
  This result makes use of a general equivalence theorem relating two recently
developed notions of distortion for metric embedding. The first is the notion
of scaling distortion, which provides improved distortion for $1-\epsilon$
fractions of the pairs, for all $\epsilon$ simultaneously. A stronger version
called coarse scaling distortion, has improved distortion guarantees for the
furthest pairs. The second notion is that of prioritized distortion, a property
allowing to prioritize the nodes whose associated distortions will be improved.
We show that prioritized distortion is essentially equivalent to coarse scaling
distortion via a general transformation.


title:
Study of the hyperfine fields in the BaFe$_2$As$_2$ family and its
  relation to the magnetic moment

abstract:
  The hyperfine field $B_\text{hf}$ and the magnetic properties of the
BaFe$_2$As$_2$ family are studied using the fully relativistic Dirac formalism
for different types of substitution. The study covers electron doped
Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$ and Ba(Fe$_{1-x}$Ni$_x$)$_2$As$_2$, hole doped
(Ba$_{1-x}$K$_x$)Fe$_2$As$_2$ and also isovalently doped
Ba(Fe$_{1-x}$Ru$_x$)$_2$As$_2$ and BaFe$_2$(As$_{1-x}$P$_x$)$_2$ for a wide
range of the concentration $x$. For the substituted compounds the hyperfine
fields show a very strong dependence on the dopant type and its concentration
$x$. Relativistic contributions were found to have a significantly stronger
impact for the iron pnictides when compared to bulk Fe. As an important
finding, we demonstrate that it is not sensible to relate the hyperfine field
$B_\text{hf}$ to the average magnetic moment $\mu$ of the compound, as it was
done in earlier literature.


title:
Emergence and non-typicality of the finiteness of the attractors in many
  topologies

abstract:
  We will introduce the notion of Emergence for a dynamical system, and we will
conjecture the local typicality of super-polynomial ones. Then, as part of this
program, we will provide sufficient conditions for an open set of Cd-families
of Cr-dynamics to contain a Baire generic set formed by families displaying
infinitely many sinks at every parameter, for all 1 \le d \le r with d finite
(and r possibly infinite) for two different topologies on families. In
particular the case d=r=1 is new.


title:
Atlantis, Carli and Bailly, and a short discussion about 'demonstration'
  in cultural astronomy

abstract:
  Some European scholars in the second half of 18th century discussed the myth
of Atlantis taking into account the studies of the evolution of the Earth and
of the beginning and diffusion of civilization, in particular the beginning of
astronomy. Atlantis was considered the cradle of the civilization, and while
J.S. Bailly proposed that it was located in the Arctic and tried to convince
Voltaire about his idea, G.R. Carli maintained the classical position in the
Atlantic Ocean. Bailly's arguments and their criticism by Carli are of some
interest, since they remind of the general problems that still plague cultural
astronomy and archaeoastronomy. I will mention briefly the methodological
problem of demonstration and evidence in these fields, and finally I will
suggest a possible psychological limit when dealing with these topics.


title: Field driven magnetostructural transitions in GeCo$_2$O$_4$

abstract:
  In the spinel compound GeCo$_2$O$_4$, the Co$^{2+}$ pyrochlore sublattice
presents remarkable magnetic field-induced behaviors that we unveil through
neutron and X-ray single-crystal diffraction. The N\'eel ordered magnetic phase
is entered through a structural lowering of the cubic symmetry. In this phase,
when a magnetic field is applied along a 2-fold cubic direction, a spin-flop
transition of one fourth of the magnetic moments releases the magnetic
frustration and triggers magnetostructural effects. At high field, these
ultimately lead to an unusual spin reorientation associated to structural
changes.


title: The puzzling properties of the magnetic O star Tr16-22

abstract:
  (abridged version) Context : The detection of bright, hard, and variable
X-ray emission in Tr16-22 prompted spectropolarimetric observations of this
star, which in turn led to the discovery of a surface magnetic field. Aims : We
want to further constrain the properties of this star, in particular to verify
whether X-ray variations are correlated to changes in optical emission lines
and magnetic field strength, as expected from the oblique rotator model that is
widely accepted for magnetic O stars. Methods: We have obtained new
low-resolution spectropolarimetric and long-term high-resolution spectroscopic
monitoring of Tr16-22, and we also analyse new, serendipitous X-ray data.
Results: The new X-ray observations are consistent with previous data, but
their addition does not help to solve the ambiguity in the variation timescale
because of numerous aliases. No obvious periodicity or any large variations are
detected in the spectropolarimetric data of Tr16-22 obtained over three months.
The derived field values appear to be in line with previous measurements,
suggesting constancy of the field (though the possibility of small, short-term
field variations cannot be excluded). Variations in the equivalent widths of
Halpha are very small, and they do not appear to be related to the X-ray
timescale; the overall lack of large variations in optical emission lines is
consistent with the magnetic field constancy. In addition, variations of the
radial velocities indicate that Tr16-22 is probably a SB1 binary with a very
long period.


title: Where does the X(5568) structure come from?

abstract:
  We study the semi-exclusive production of $\pi^\pm B_s^0$ pairs in hadron
colliders which is associated with the $X(5568)$ structure observed by the D0
Collaboration in 2016, but that was not confirmed by LHCb and CMS later. The
reason of its appearance in the D0 and absence in LHCb and CMS is discussed in
this letter. In a semi-exclusive process, one might miss the third particle
which is produced together with the $\pi^\pm B_s^0$ simultaneously. In the
three-body Dalitz plot, once the remaining region is narrow enough after the
kinematic cuts, its reflection to another invariant mass distribution will
accumulate a large number of events within a specific energy region. If there
is an enhancement in the remaining region, it will make the reflection
structure more pronounced. The precise line shape of the reflection will depend
on the specific interaction form. A combined study of different cone cuts and
the low-energy dynamics, e.g. the Landau singularity, demonstrates that the
$X(5568)$ structure could come from this kinematic reflection. This conclusion
can be checked by both searching for the enhancement in another invariant mass
distribution, such as $B_s^0\bar{B}^0$, and the cone cut dependence of the
$X(5568)$ mass. Such a combined study can be used to distinguish the effects of
the triangle singularity from a genuine state. We also propose how to avoid
this kinematic reflection in future experimental analysis.


title: Lefschetz classes on projective varieties

abstract:
  The Lefschetz algebra $L^*(X)$ of a smooth complex projective variety $X$ is
the subalgebra of the cohomology algebra of $X$ generated by divisor classes.
We construct smooth complex projective varieties whose Lefschetz algebras do
not satisfy analogues of the hard Lefschetz theorem and Poincar\'e duality.


title:
Dynamically creating tripartite resonance and dark modes in a multimode
  optomechanical system

abstract:
  We study a multimode optomechanical system where two mechanical oscillators
are coupled to an electromagnetic cavity. Previously it has been shown that if
the mechanical resonances have nearly equal frequencies, one can make the
oscillators to interact via the cavity by strong pumping with a coherent pump
tone. One can view the interaction also as emergence of an electromagnetically
dark mode which gets asymptotically decoupled from the cavity and has a
linewidth much smaller than that of the bare cavity. The narrow linewidth and
long lifetime of the dark mode could be advantageous for example in information
storage and processing. Here we investigate the possibility to create dark
modes dynamically using two pump tones. We show that if the mechanical
frequencies are intrinsically different, one can bring the mechanical
oscillators and the cavity on-resonance and thus create a dark mode by double
sideband pumping of the cavity. We realize the scheme in a microwave
optomechanical device employing two drum oscillators with unmatched
frequencies, {\omega}_1 /2{\pi} = 8.1MHz and {\omega}_2 /2{\pi} = 14.2MHz. We
also observe a breakdown of the rotating-wave approximation, most pronounced in
another device where the mechanical frequencies are close to each other.


title:
Effective Combination of Language and Vision Through Model Composition
  and the R-CCA Method

abstract:
  We address the problem of integrating textual and visual information in
vector space models for word meaning representation. We first present the
Residual CCA (R-CCA) method, that complements the standard CCA method by
representing, for each modality, the difference between the original signal and
the signal projected to the shared, max correlation, space. We then show that
constructing visual and textual representations and then post-processing them
through composition of common modeling motifs such as PCA, CCA, R-CCA and
linear interpolation (a.k.a sequential modeling) yields high quality models. On
five standard semantic benchmarks our sequential models outperform recent
multimodal representation learning alternatives, including ones that rely on
joint representation learning. For two of these benchmarks our R-CCA method is
part of the Best configuration our algorithm yields.


title:
On-board Communication-based Relative Localization for Collision
  Avoidance in Micro Air Vehicle teams

abstract:
  Micro Air Vehicles (MAVs) will unlock their true potential once they can
operate in groups. To this end, it is essential for them to estimate on-board
the relative location of their neighbors. The challenge lies in limiting the
mass and processing burden needed to enable this. We developed a relative
localization method that only requires the MAVs to communicate via their
wireless transceiver. Communication allows the exchange of on-board states
(velocity, height, and orientation), while the signal-strength provides range
data. These quantities are fused to provide a full relative location estimate.
We used our method to tackle the problem of collision avoidance in tight areas.
The system was tested with a team of AR.Drones flying in a 4mx4m area and with
miniature drones of ~50g in a 2mx2m area. The MAVs were able to track their
relative positions and fly several minutes without collisions. Our
implementation used Bluetooth to communicate between the drones. This featured
significant noise and disturbances in signal-strength, which worsened as more
drones were added. Simulation analysis suggests that results can improve with a
more suitable transceiver module.


title: Effective magnetic correlations in hole-doped graphene nanoflakes

abstract:
  The magnetic properties of zig-zag graphene nanoflakes (ZGNF) are
investigated within the framework of the dynamical mean-field theory. At
half-filling and for realistic values of the local interaction, the ZGNF is in
a fully compensated antiferromagnetic (AF) state, which is found to be robust
against temperature fluctuations. Introducing charge carriers in the AF
background drives the ZGNF metallic and stabilizes a magnetic state with a net
uncompensated moment at low temperature. The change in magnetism is ascribed to
the delocalization of the doped holes in the proximity of the edges, which
mediate ferromagnetic correlations between the localized magnetic moments.
Depending on the hole concentration, the magnetic transition may display a
pronounced hysteresis over a wide range of temperature, indicating the
coexistence of magnetic states with different symmetry. This suggests the
possibility of achieving the electrostatic control of the magnetic state of
ZGNFs to realize a switchable spintronic device.


title: Reduced-Complexity SCL Decoding of Multi-CRC-Aided Polar Codes

abstract:
  Cyclic redundancy check (CRC) aided polar codes are capable of achieving
better performance than low-density parity-check (LDPC) codes under the
successive cancelation list (SCL) decoding scheme. However, the SCL decoding
scheme suffers from very high space and time complexities. Especially, the high
space complexity is a major concern for adopting polar codes in modern mobile
communication standards. In this paper, we propose a novel reduced-complexity
successive cancelation list (R-SCL) decoding scheme which is effective to
reduce the space complexity. Simulation results show that, with a (2048, 1024)
CRC-aided polar code, the R-SCL decoders with 25% reduction of space complexity
and 8% reduction of time complexity can still achieve almost the same
performance levels as those decoded by SCL decoders. To further reduce the
complexity, we propose a multi-CRC coding scheme for polar codes. Simulation
results show that, with a (16384, 8192) multi-CRC-aided polar code, a R-SCL
decoder with about 85% reduction of space complexity and 20% reduction of time
complexity results in a worst performance loss of only 0.04dB.


title: An extension procedure for the constraint equations

abstract:
  Let $( \bar g, \bar k)$ be a solution to the maximal constraint equations of
general relativity on the unit ball $B_1$ of $\mathbb{R}^3$. We prove that if
$(\bar g,\bar k)$ is sufficiently close to the initial data for Minkowski
space, then there exists an asymptotically flat solution $(g,k)$ on
$\mathbb{R}^3$ that extends $(\bar g, \bar k)$. Moreover, $(g,k)$ is bounded by
$(\bar g, \bar k)$ and has the same regularity. Our proof uses a new method of
solving the prescribed divergence equation for a tracefree symmetric
$2$-tensor, and a geometric variant of the conformal method to solve the
prescribed scalar curvature equation for a metric. Both methods are based on
the implicit function theorem and an expansion of tensors based on spherical
harmonics. They are combined to define an iterative scheme that is shown to
converge to a global solution $(g,k)$ of the maximal constraint equations which
extends $(\bar g,\bar k)$.


title: On $\sigma$-semipermutable subgroups of finite groups

abstract:
  Let $\sigma =\{\sigma_{i} | i\in I\}$ be some partition of the set of all
primes $\Bbb{P}$, $G$ a finite group and $\sigma (G) =\{\sigma_{i}
|\sigma_{i}\cap \pi (G)\ne \emptyset \}$. A set ${\cal H}$ of subgroups of $G$
is said to be a \emph{complete Hall $\sigma $-set} of $G$ if every member $\ne
1$ of ${\cal H}$ is a Hall $\sigma_{i}$-subgroup of $G$ for some $\sigma_{i}\in
\sigma $ and ${\cal H}$ contains exact one Hall $\sigma_{i}$-subgroup of $G$
for every $\sigma_{i}\in \sigma (G)$. A subgroup $H$ of $G$ is said to be:
\emph{${\sigma}$-semipermutable in $G$ with respect to ${\cal H}$} if
$HH_{i}^{x}=H_{i}^{x}H$ for all $x\in G$ and all $H_i\in {\cal H}$ such that
$(|H|, |H_{i}|)=1$; \emph{${\sigma}$-semipermutable in $G$} if $H$ is
${\sigma}$-semipermutable in $G$ with respect to some complete Hall $\sigma
$-set of $G$. We study the structure of $G$ being based on the assumption that
some subgroups of $G$ are ${\sigma}$-semipermutable in $G$.


title:
Identifying Causal Effects With Proxy Variables of an Unmeasured
  Confounder

abstract:
  We consider a causal effect that is confounded by an unobserved variable, but
with observed proxy variables of the confounder. We show that, with at least
two independent proxy variables satisfying a certain rank condition, the causal
effect is nonparametrically identified, even if the measurement error
mechanism, i.e., the conditional distribution of the proxies given the con-
founder, may not be identified. Our result generalizes the identification
strategy of Kuroki & Pearl (2014) that rests on identification of the
measurement error mechanism. When only one proxy for the confounder is
available, or the required rank condition is not met, we develop a strategy to
test the null hypothesis of no causal effect.


title: The $^{26}$Al Gamma-ray Line from Massive-Star Regions

abstract:
  The measurement of gamma rays from the diffuse afterglow of radioactivity
originating in massive-star nucleosynthesis is considered a laboratory for
testing models, when specific stellar groups are investigated, at known
distance and with well-constrained stellar population. Regions which have been
exploited for such studies include Cygnus, Carina, Orion, and
Scorpius-Centaurus. The Orion region hosts the Orion OB1 association and its
subgroups at about 450~pc distance. We report the detection of $^{26}$Al gamma
rays from this region with INTEGRAL/SPI.


title: Fundamental thermal noise in droplet microresonators

abstract:
  Liquid droplet whispering-gallery-mode microresonators open a new research
frontier for optomechanics and photonic devices. At visible wavelengths, where
most liquids are transparent, a major contribution to a droplet optical quality
factor is expected theoretically from thermal surface distortions and capillary
waves. Here, we investigate experimentally these predictions using transient
cavity ring-down spectroscopy. In this way, the optical out-coupling and
intrinsic loss are measured independently while any perturbation induced by
thermal, acoustic and laser-frequency noise is avoided thanks to the
ultra-short light-cavity interaction time. The measurements reveal a photon
lifetime ten times longer than the thermal limit and suggest that capillary
fluctuations activate surface scattering effects responsible for light
coupling.


title:
Stable dark and bright soliton Kerr combs can coexist in normal
  dispersion resonators

abstract:
  Using the Lugiato-Lefever model, we analyze the effects of third order
chromatic dispersion on the existence and stability of dark and bright soliton
Kerr frequency combs in the normal dispersion regime. While in the absence of
third order dispersion only dark solitons exist over an extended parameter
range, we find that third order dispersion allows for stable dark and bright
solitons to coexist. Reversibility is broken and the shape of the switching
waves connecting the top and bottom homogeneous solutions is modified. Bright
solitons come into existence thanks to the generation of oscillations in the
switching wave profiles. Finally, oscillatory instabilities of dark solitons
are also suppressed in the presence of sufficiently strong third order
dispersion.


title: Localization bounds for the graph translation

abstract:
  The graph translation operator has been defined with good spectral properties
in mind, and in particular with the end goal of being an isometric operator.
Unfortunately, the resulting definitions do not provide good intuitions on a
vertex-domain interpretation. In this paper, we show that this operator does
have a vertex-domain interpretation as a diffusion operator using a polynomial
approximation. We show that its impulse response exhibit an exponential decay
of the energy way from the impulse, demonstrating localization preservation.
Additionally, we formalize several techniques that can be used to study other
graph signal operators.


title: Model Reduction from Partial Observations

abstract:
  This paper deals with model-order reduction of parametric partial
differential equations (PPDE). More specifically, we consider the problem of
finding a good approximation subspace of the solution manifold of the PPDE when
only partial information on the latter is available. We assume that two sources
of information are available: i) a "rough" prior knowledge, taking the form of
a manifold containing the target solution manifold, ii) partial linear
measurements of the solutions of the PPDE (the term partial refers to the fact
that observation operator cannot be inverted). We provide and study several
tools to derive good approximation subspaces from these two sources of
information. We first identify the best worst-case performance achievable in
this setup and propose simple procedures to approximate the corresponding
optimal approximation subspace. We then provide, in a simplified setup, a
theoretical analysis relating the achievable reduction performance to the
choice of the observation operator and the prior knowledge available on the
solution manifold.


title:
Quantitative separation of the anisotropic magnetothermopower and planar
  Nernst effect by the rotation of an in-plane thermal gradient

abstract:
  A thermal gradient as the driving force for spin currents plays a key role in
spin caloritronics. In this field the spin Seebeck effect (SSE) is of major
interest and was investigated in terms of in-plane thermal gradients inducing
perpendicular spin currents (transverse SSE) and out-of-plane thermal gradients
generating parallel spin currents (longitudinal SSE). Up to now all spincaloric
experiments employ a spatially fixed thermal gradient. Thus anisotropic
measurements with respect to well defined crystallographic directions were not
possible. Here we introduce a new experiment that allows not only the in-plane
rotation of the external magnetic field, but also the rotation of an in-plane
thermal gradient controlled by optical temperature detection. As a consequence,
the anisotropic magnetothermopower and the planar Nernst effect in a permalloy
thin film can be measured simultaneously and reveal a phase shift, that allows
the quantitative separation of the thermopower, the anisotropic
magnetothermopower and the planar Nernst effect.


title:
Non-Autonomous Maximal Regularity for Forms Given by Elliptic Operators
  of Bounded Variation

abstract:
  We show maximal $L^p$-regularity for non-autonomous Cauchy problems provided
the trace spaces are stable in some parameterized sense and the time dependence
is of bounded variation. In particular, on $L^2$, we obtain for all $p \in
(1,2]$ maximal $L^p$-regularity for non-autonomous elliptic operators with
measurable coefficients.


title: Equation Parsing: Mapping Sentences to Grounded Equations

abstract:
  Identifying mathematical relations expressed in text is essential to
understanding a broad range of natural language text from election reports, to
financial news, to sport commentaries to mathematical word problems. This paper
focuses on identifying and understanding mathematical relations described
within a single sentence. We introduce the problem of Equation Parsing -- given
a sentence, identify noun phrases which represent variables, and generate the
mathematical equation expressing the relation described in the sentence. We
introduce the notion of projective equation parsing and provide an efficient
algorithm to parse text to projective equations. Our system makes use of a high
precision lexicon of mathematical expressions and a pipeline of structured
predictors, and generates correct equations in $70\%$ of the cases. In $60\%$
of the time, it also identifies the correct noun phrase $\rightarrow$ variables
mapping, significantly outperforming baselines. We also release a new annotated
dataset for task evaluation.


title:
A model for straight and helical solar jets: II. Parametric study of the
  plasma beta

abstract:
  Jets are dynamic, impulsive, well-collimated plasma events that develop at
many different scales and in different layers of the solar atmosphere.
  Jets are believed to be induced by magnetic reconnection, a process central
to many astrophysical phenomena. Within the solar atmosphere, jet-like events
develop in many different environments, e.g., in the vicinity of active regions
as well as in coronal holes, and at various scales, from small photospheric
spicules to large coronal jets. In all these events, signatures of helical
structure and/or twisting/rotating motions are regularly observed. The present
study aims to establish that a single model can generally reproduce the
observed properties of these jet-like events.
  In this study, using our state-of-the-art numerical solver ARMS, we present a
parametric study of a numerical tridimensional magnetohydrodynamic (MHD) model
of solar jet-like events. Within the MHD paradigm, we study the impact of
varying the atmospheric plasma $\beta$ on the generation and properties of
solar-like jets.
  The parametric study validates our model of jets for plasma $\beta$ ranging
from $10^{-3}$ to $1$, typical of the different layers and magnetic
environments of the solar atmosphere. Our model of jets can robustly explain
the generation of helical solar jet-like events at various $\beta \le 1$. This
study introduces the new result that the plasma $\beta$ modifies the morphology
of the helical jet, explaining the different observed shapes of jets at
different scales and in different layers of the solar atmosphere.
  Our results allow us to understand the energisation, triggering, and driving
processes of jet-like events. Our model allows us to make predictions of the
impulsiveness and energetics of jets as determined by the surrounding
environment, as well as the morphological properties of the resulting jets.


title:
On Sums Involving Fourier Coefficients of Maass Forms for
  $\mathrm{SL}(3,\mathbb Z)$

abstract:
  We derive a truncated Voronoi identity for rationally additively twisted sums
of Fourier coefficients of Maass forms for $\mathrm{SL}(3,\mathbb Z)$, and as
an application obtain a pointwise estimate and a second moment estimate for the
sums in question.


title:
Anytime Discovery of a Diverse Set of Patterns with Monte Carlo Tree
  Search

abstract:
  The discovery of patterns that accurately discriminate one class label from
another remains a challenging data mining task. Subgroup discovery (SD) is one
of the frameworks that enables to elicit such interesting hypotheses from
labeled data. A question remains fairly open: How to select an accurate
heuristic search technique when exhaustive enumeration of the pattern space is
infeasible? Existing approaches make use of beam-search, sampling and genetic
algorithms for discovering a pattern set that is non-redundant and of high
quality w.r.t. a pattern quality measure. We argue that such approaches produce
pattern sets that lack of diversity: Only few patterns of high quality, and
different enough, are discovered. Our main contribution is then to formally
define pattern mining as a game and to solve it with Monte Carlo tree search
(MCTS). It can be seen as an exhaustive search guided by random simulations
which can be stopped early (limited budget) by virtue of its best-first search
property. We show through a comprehensive set of experiments how MCTS enables
the anytime discovery of a diverse pattern set of high quality. It outperforms
other approaches when dealing with a large pattern search space and for
different quality measures. Thanks to its genericity, our MCTS settings can be
used for SD but also for many other pattern mining tasks.


title: Geometry of mutation classes of rank $3$ quivers

abstract:
  We present a geometric realization for all mutation classes of quivers of
rank $3$ with real weights. This realization is via linear reflection groups
for acyclic mutation classes and via groups generated by $\pi$-rotations for
the cyclic ones. The geometric behavior of the model turns out to be controlled
by the Markov constant $p^2+q^2+r^2-pqr$, where $p,q,r$ are the elements of
exchange matrix. We also classify skew-symmetric mutation-finite real $3\times
3$ matrices and explore the structure of acyclic representatives in finite and
infinite mutation classes.


title:
Resonant optical control of the spin of a single Cr atom in a quantum
  dot

abstract:
  A Cr atom in a semiconductor host carries a localized spin with an intrinsic
large spin to strain coupling particularly promising for the development of
hybrid spin-mechanical systems and coherent mechanical spin driving. We
demonstrate here that the spin of an individual Cr atom inserted in a
semiconductor quantum dot can be controlled optically. We first show that a Cr
spin can be prepared by resonant optical pumping. Monitoring the time
dependence of the intensity of the resonant fluorescence of the quantum dot
during this process permits to probe the dynamics of the optical initialization
of the Cr spin. Using this initialization and read-out technique we measured a
Cr spin relaxation time at T=5 K of about 2 microseconds. We finally
demonstrate that, under a resonant single mode laser field, the energy of any
spin state of an individual Cr atom can be independently tuned by using the
optical Stark effect.


title: Robustness Properties in Fictitious-Play-Type Algorithms

abstract:
  Fictitious play (FP) is a canonical game-theoretic learning algorithm which
has been deployed extensively in decentralized control scenarios. However
standard treatments of FP, and of many other game-theoretic models, assume
rather idealistic conditions which rarely hold in realistic control scenarios.
This paper considers a broad class of best response learning algorithms, that
we refer to as FP-type algorithms. In such an algorithm, given some (possibly
limited) information about the history of actions, each individual forecasts
the future play and chooses a (myopic) best action given their forecast. We
provide a unifed analysis of the behavior of FP-type algorithms under an
important class of perturbations, thus demonstrating robustness to deviations
from the idealistic operating conditions that have been previously assumed.
This robustness result is then used to derive convergence results for two
control-relevant relaxations of standard game-theoretic applications:
distributed (network-based) implementation without full observability and
asynchronous deployment (including in continuous time). In each case the
results follow as a direct consequence of the main robustness result.


title: Equivalent-neighbor Potts models in two dimensions

abstract:
  We investigate the two-dimensional $q=3$ and 4 Potts models with a variable
interaction range by means of Monte Carlo simulations. We locate the phase
transitions for several interaction ranges as expressed by the number $z$ of
equivalent neighbors. For not too large $z$, the transitions fit well in the
universality classes of the short-range Potts models. However, at longer ranges
the transitions become discontinuous. For $q=3$ we locate a tricritical point
separating the continuous and discontinuous transitions near $z=80$, and a
critical fixed point between $z=8$ and 12. For $q=4$ the transition becomes
discontinuous for $z > 16$. The scaling behavior of the $q=4$ model with $z=16$
approximates that of the $q=4$ merged critical-tricritical fixed point
predicted by the renormalization scenario.


title: Global existence results for viscoplasticity at finite strain

abstract:
  We study a model for rate-dependent gradient plasticity at finite strain
based on the multiplicative decomposition of the strain tensor, and investigate
the existence of global-in-time solutions to the related PDE system. We reveal
its underlying structure as a generalized gradient system, where the driving
energy functional is highly nonconvex and features the geometric nonlinearities
related to finite-strain elasticity as well as the multiplicative decomposition
of finite-strain plasticity. Moreover, the dissipation potential depends on the
left-invariant plastic rate and thus, depends on the plastic state variable.
  The existence theory is developed for a class of abstract, nonsmooth, and
nonconvex gradient systems, for which we introduce suitable notions of
solutions, namely energy-dissipation-balance (EDB) and
energy-dissipation-inequality (EDI) solutions. Hence, we resort to the toolbox
of the direct method of the calculus of variations to check that the specific
energy and dissipation functionals for our viscoplastic models comply with the
conditions of the general theory.


title:
Metropolis updates for Diagrammatic Monte-Carlo algorithms from
  Schwinger-Dyson equations

abstract:
  We describe a general recipe for constructing Metropolis updates for
Diagrammatic Monte-Carlo (DiagMC) algorithms, based on the Schwinger-Dyson
equations in quantum field theory. This approach bypasses explicit duality
transformations, enumeration or classification of diagrams and can be used for
lattice quantum field theories with unknown or complicated dual representations
(such as non-Abelian lattice gauge theories). DiagMC algorithms constructed in
this way can still be plagued by the sign problem, which is, however,
completely different from the sign problem in conventional Monte-Carlo
simulations and has its origin in cancellations between diagrams with positive
and negative weights. To test the presented approach, we apply DiagMC to
calculate the first 7 orders of 1/N expansion in the quartic matrix model and
find good agreement with analytic results, with the exception of the close
vicinity of the critical coupling where the critical slowing down sets in.


title:
Multi-phase environment of compact galactic nuclei: the role of the
  Nuclear Star Cluster

abstract:
  We study the conditions for the onset of Thermal Instability in the innermost
regions of compact galactic nuclei, where the properties of the interstellar
environment are governed by the interplay of quasi-spherical accretion onto a
supermassive black hole (SMBH) and the heating/cooling processes of gas in a
dense nuclear star cluster. Stellar winds are the source of material for
radiatively inefficient (quasi-spherical, non-magnetised) inflow/outflow onto
the central SMBH, where a stagnation point develops within the Bondi type
accretion. We study the local thermal equilibrium to determine the parameter
space which allows cold and hot phases in mutual contact to co-exist. We
include the effects of mechanical heating by stellar winds and radiative
cooling/heating by the ambient field of the dense star cluster. We consider two
examples: the Nuclear Star Cluster (NSC) in the Milky Way central region
(including the gaseous Mini-spiral of Sgr~A*), and the Ultra-Compact Dwarf
galaxy M60-UCD1. We find that the two systems behave in different ways because
they are placed in different areas of parameter space in the instability
diagram: gas temperature vs. dynamical ionization parameter. In the case of
Sgr~A*, stellar heating prevents the spontaneous formation of cold clouds. The
plasma from stellar winds joins the hot X-ray emitting phase and forms an
outflow. In M60-UCD1 our model predicts spontaneous formation of cold clouds in
the inner part of the galaxy. These cold clouds may survive since the cooling
timescale is shorter than the inflow/outflow timescale.


title: Resolutions for unit groups of orders

abstract:
  We present a general algorithm for constructing a free resolution for unit
groups of orders in semisimple rational algebras. The approach is based on
computing a contractible $G$-complex employing the theory of minimal classes of
quadratic forms and Opgenorth's theory of dual cones. The information from the
complex is then used together with Wall's perturbation lemma to obtain the
resolution.


title:
How accurate are infrared luminosities from monochromatic photometric
  extrapolation?

abstract:
  Template-based extrapolations from only one photometric band can be a
cost-effective method to estimate the total infrared (IR) luminosities
($L_{\mathrm{IR}}$) of galaxies. By utilizing multi-wavelength data that covers
across 0.35--500\,$\mathrm{\mu m}$ in GOODS-North and GOODS-South fields, we
investigate the accuracy of this monochromatic extrapolated $L_{\mathrm{IR}}$
based on three IR spectral energy distribution (SED) templates
(\citealt[CE01]{Chary2001}; \citealt[DH02]{Dale2002};
\citealt[W08]{Wuyts2008a}) out to $z\sim 3.5$. We find that the CE01 template
provides the best estimate of $L_{\mathrm{IR}}$ in {\it Herschel}/PACS bands,
while the DH02 template performs best in {\it Herschel}/SPIRE bands. To
estimate $L_{\mathrm{IR}}$, we suggest that extrapolations from the available
longest wavelength PACS band based on the CE01 template can be a good
estimator. Moreover, if PACS measurement is unavailable, extrapolations from
SPIRE observations but based on the \cite{Dale2002} template can also provide a
statistically unbiased estimate for galaxies at $z\lesssim 2$. The emission of
rest-frame 10--100\,$\mathrm{\mu m}$ range of IR SED can be well described by
all the three templates, but only the DH02 template shows nearly unbiased
estimate of the emission of the rest-frame submillimeter part.


title: Bass--Serre trees of amalgamated free product C*-algebras

abstract:
  For any reduced amalgamated free product $\mathrm{C}^*$-algebra $(A,E)=(A_1,
E_1) \ast_D (A_2,E_2)$, we introduce and study a canonical ambient
$\mathrm{C}^*$-algebra $\Delta\mathbf{T}(A,E)$ of $A$ which generalizes the
crossed product arising from the canonical action of an amalgamated free
product group on the compactification of the associated Bass--Serre tree. Using
an explicit identification of $\Delta \mathbf{T}(A,E)$ with a Cuntz--Pimsner
algebra we prove two kinds of "amenability" results for $\Delta
\mathbf{T}(A,E)$; nuclearity and universality. As applications of our
framework, we provide new conceptual, and simpler proofs of several known
theorems on approximation properties, embeddability, and $KK$-theory for
reduced amalgamated free product $\mathrm{C}^*$-algebras.


title:
Constraining the Galactic structure parameters with the XSTPS-GAC and
  SDSS photometric surveys

abstract:
  Photometric data from the Xuyi Schmidt Telescope Photometric Survey of the
Galactic Anticentre (XSTPS-GAC) and the Sloan Digital Sky Survey (SDSS) are
used to derive the global structure parameters of the smooth components of the
Milky Way. The data, which cover nearly 11,000 deg$^2$ sky area and the full
range of Galactic latitude, allow us to construct a globally representative
Galactic model. The number density distribution of Galactic halo stars is
fitted with an oblate spheroid that decays by power law. The best-fit yields an
axis ratio and a power law index $\kappa=0.65$ and $p=2.79$, respectively. The
$r$-band differential star counts of three dwarf samples are then fitted with a
Galactic model. The best-fit model yielded by a Markov Chain Monte Carlo
analysis has thin and thick disk scale heights and lengths of $H_{1}=$ 322\,pc
and $L_{1}=$2343\,pc, $H_{2}=$794\,pc and $L_{2}=$3638\,pc, a local
thick-to-thin disk density ratio of $f_2=$11\,per\,cent, and a local density
ratio of the oblate halo to the thin disk of $f_h=$0.16\,per\,cent. The
measured star count distribution, which is in good agreement with the above
model for most of the sky area, shows a number of statistically significant
large scale overdensities, including some of the previously known
substructures, such as the Virgo overdensity and the so-called "north near
structure", and a new feature between 150\degr $< l < $ 240\degr~and $-1$5\degr
$< b < $ $-$5\degr, at an estimated distance between 1.0 and 1.5\,kpc. The
Galactic North-South asymmetry in the anticentre is even stronger than
previously thought.


title: A Numerical Study of Newton Interpolation with Extremely High Degrees

abstract:
  In current textbooks the use of Chebyshev nodes with Newton interpolation is
advocated as the most efficient numerical interpolation method in terms of
approximation accuracy and computational effort. However, we show numerically
that the approximation quality obtained by Newton interpolation with Fast Leja
(FL) points is competitive to the use of Chebyshev nodes, even for extremely
high degree interpolation. This is an experimental account of the analytic
result that the limit distribution of FL points and Chebyshev nodes is the same
when letting the number of points go to infinity. Since the FL construction is
easy to perform and allows to add interpolation nodes on the fly in contrast to
the use of Chebyshev nodes, our study suggests that Newton interpolation with
FL points is currently the most efficient numerical technique for polynomial
interpolation. Moreover, we give numerical evidence that any reasonable
function can be approximated up to machine accuracy by Newton interpolation
with FL points if desired, which shows the potential of this method.


title:
Tests of the Galactic planetary nebula distance scale with the initial
  Gaia parallax distances of their central stars

abstract:
  We used the "primary dataset" of Gaia Data Release 1 (DR1) to search for
parallax measurements of central stars (CSs) of Galactic planetary nebulae
(PNe), to determine PN distances. We found that a trigonometric parallax is
available for 16 CSs, seven of which with relative uncertainty below 80%. The
limited comparison of these trigonometric distances to other reliable
individual determinations discloses good correlation between the two sets, with
the Gaia parallax distances being lower by a factor of ~0.1 dex in the
logarithmic distances. We tested with the Gaia parallaxes the most popular
Galactic PN distance scales, namely, the physical radius vs. surface
brightness, and the ionized mass vs. inverse optical thickness scales. While
the number of available calibrators may still be too low, and their relative
uncertainties too high, to derive a working distance scale, we were able to
assess the current sample and to reveal the very promising potential of the
future Gaia releases for a recalibration of the distance scale of Galactic PNe.


title:
Butterfly Effect and Holographic Mutual Information under External Field
  and Spatial Noncommutativity

abstract:
  We apply the transformation of mixing azimuthal and internal coordinate or
mixing time and internal coordinate to a stack of N black M-branes to find the
Melvin spacetime of a stack of N black D-branes with magnetic or electric flux
in string theory, after the Kaluza-Klein reduction. We slightly extend previous
formulas to investigate the external magnetic and electric effects on the
butterfly effect and holographic mutual information. It shows that the Melvin
fields do not modify the scrambling time and will enhance the mutual
information. In addition, we also T-dualize and twist a stack of N black
D-branes to find a Melvin Universe supported by the flux of the NSNS b-field,
which describes a non-comutative spacetime. It also shows that the spatial
noncommutativity does not modify the scrambling time and will enhance the
mutual information. We also study the corrected mutual information in the
backreaction geometry due to the shock wave in our three model spacetimes.


title: Analysis of Carrier's problem

abstract:
  A computational and asymptotic analysis of the solutions of Carrier's problem
is presented. The computations reveal a striking and beautiful bifurcation
diagram, with an infinite sequence of alternating pitchfork and fold
bifurcations as the bifurcation parameter tends to zero. The method of Kuzmak
is then applied to construct asymptotic solutions to the problem. This
asymptotic approach explains the bifurcation structure identified numerically,
and its predictions of the bifurcation points are in excellent agreement with
the numerical results. The analysis yields a novel and complete taxonomy of the
solutions to the problem, and demonstrates that a claim of Bender & Orszag is
incorrect.


title: Hierarchical Memory Networks for Answer Selection on Unknown Words

abstract:
  Recently, end-to-end memory networks have shown promising results on Question
Answering task, which encode the past facts into an explicit memory and perform
reasoning ability by making multiple computational steps on the memory.
However, memory networks conduct the reasoning on sentence-level memory to
output coarse semantic vectors and do not further take any attention mechanism
to focus on words, which may lead to the model lose some detail information,
especially when the answers are rare or unknown words. In this paper, we
propose a novel Hierarchical Memory Networks, dubbed HMN. First, we encode the
past facts into sentence-level memory and word-level memory respectively. Then,
(k)-max pooling is exploited following reasoning module on the sentence-level
memory to sample the (k) most relevant sentences to a question and feed these
sentences into attention mechanism on the word-level memory to focus the words
in the selected sentences. Finally, the prediction is jointly learned over the
outputs of the sentence-level reasoning module and the word-level attention
mechanism. The experimental results demonstrate that our approach successfully
conducts answer selection on unknown words and achieves a better performance
than memory networks.


title: Monovex Sets

abstract:
  A set $A$ in a finite dimensional Euclidean space is \emph{monovex} if for
every two points $x,y \in A$ there is a continuous path within the set that
connects $x$ and $y$ and is monotone (nonincreasing or nondecreasing) in each
coordinate. We prove that every open monovex set as well as every closed
monovex set is contractible, and provide an example of a nonopen and nonclosed
monovex set that is not contractible. Our proofs reveal additional properties
of monovex sets.


title: On Shared Rate Time Series for Mobile Users in Poisson Networks

abstract:
  This paper focuses on modeling and analysis of the temporal performance
variations experienced by a mobile user in a wireless network and its impact on
system level design. We consider a simple stochastic geometry model: the
infrastructure nodes are Poisson distributed while the user's motion is the
simplest possible i.e., constant velocity on a straight line. We first
characterize variations in the SNR process, and associated downlink Shannon
rate, resulting from variations in the infrastructure geometry seen by the
mobile. Specifically, by making a connection between stochastic geometry and
queueing theory the level crossings of the SNR process are shown to form an
alternating renewal process whose distribution can be completely characterized.
For large or small SNR levels, and associated rare events, we further derive
simple distributional (exponential) models. We then characterize the second
major contributor to variation, associated with changes in the number of other
users sharing infrastructure. Combining these two effects, we study what are
the dominant factors (infrastructure geometry or sharing number) given mobile
experiences a very high or low shared rate. These results are then used to
evaluate and optimize the system-level Quality of Service (QoS) and
system-level capacity to support mobile users sharing wireless infrastructure,
including mobile devices streaming video which proactively buffer content to
prevent rebuffering and mobiles which are downloading large files. Finally, we
use simulation to assess the fidelity of this model and its robustness to
factors which are presently taken into account.


title: Static and dynamic friction of hierarchical surfaces

abstract:
  Hierarchical structures are very common in Nature, but only recently have
they been systematically studied in materials physics, in order to understand
the specific effects they can have on the mechanical properties of various
systems. Structural hierarchy provides a way to tune and optimize macroscopic
mechanical properties starting from simple base constituents, and new materials
are nowadays designed exploiting this possibility. This can be also true in the
field of tribology. In this paper, we study the effect of hierarchical
patterned surfaces on the static and dynamic friction coefficients of an
elastic material. Our results are obtained by means of numerical simulations
using a 1-D spring-block model, which has previously been used to investigate
various aspects of friction. Despite the simplicity of the model, we highlight
some possible mechanisms that explain how hierarchical structures can
significantly modify the friction coefficients of a material, providing a means
to achieve tunability.


title:
The energy dependence of the diffraction minimum in the elastic
  scattering and new LHC data

abstract:
  The soft diffraction phenomena in the elastic proton-proton scattering are
reviewed from the viewpoint of experiments at the LHC (TOTEM and ATLAS
collaboration). In the framework of the High Energy Generalized Structure
(HEGS) model the form of the diffraction minimum in the nucleon-nucleon elastic
scattering in a wide energy region is analyzed. The energy dependences of the
main characteristics of the diffraction dip are obtained. The numerical
predictions at LHC energies are presented. The comparison of the model
predictions with the new LHC data at $\sqrt{s}=13$ TeV is made.


title:
Lens Model and Time Delay Predictions for the Sextuply Lensed Quasar
  SDSS J2222+2745

abstract:
  SDSS J2222+2745 is a galaxy cluster at z=0.49, strongly lensing a quasar at
z=2.805 into six widely separated images. In recent HST imaging of the field,
we identify additional multiply lensed galaxies, and confirm the sixth quasar
image that was identified by Dahle et al. (2013). We used the Gemini North
telescope to measure a spectroscopic redshift of z=4.56 of one of the secondary
lensed galaxies. These data are used to refine the lens model of SDSS
J2222+2745, compute the time delay and magnifications of the lensed quasar
images, and reconstruct the source image of the quasar host and a second lensed
galaxy at z=2.3. This second galaxy also appears in absorption in our Gemini
spectra of the lensed quasar, at a projected distance of 34 kpc. Our model is
in agreement with the recent time delay measurements of Dahle et al. (2015),
who found tAB=47.7+/-6.0 days and tAC=-722+/-24 days. We use the observed time
delays to further constrain the model, and find that the model-predicted time
delays of the three faint images of the quasar are tAD=502+/-68 days,
tAE=611+/-75 days, and tAF=415+/-72 days. We have initiated a follow-up
campaign to measure these time delays with Gemini North. Finally, we present
initial results from an X-ray monitoring program with Swift, indicating the
presence of hard X-ray emission from the lensed quasar, as well as extended
X-ray emission from the cluster itself, which is consistent with the lensing
mass measurement and the cluster velocity dispersion.


title: Volume comparison with respect to scalar curvature

abstract:
  In this article, we investigate the volume comparison with respect to scalar
curvature. In particular, we show volume comparison holds for small geodesic
balls of metrics near a V-static metric. For closed manifold, we prove the
volume comparison for metrics near a strictly stable Einstein metric. As
applications, we give a partial answer to a conjecture of Bray and recover a
result of Besson, Courtois and Gallot, which partially confirms a conjecture of
Schoen about closed hyperbolic manifold. Applying analogous techniques, we
obtain a different proof of a local rigidity result due to Dai, Wang and Wei,
which shows it admits no metric with positive scalar curvature near strictly
stable Ricci-flat metrics.


title:
Early evolution of electron cyclotron driven current during suppression
  of tearing modes in a circular tokamak

abstract:
  When electron cyclotron (EC) driven current is first applied to the inside of
a magnetic island, the current spreads throughout the island and after a short
period achieves a steady level. Using a two equation fluid model for the EC
current that allows us to examine this early evolution in detail, we analyze
high-resolution simulations of a 2/1 classical tearing mode in a low-beta large
aspect-ratio circular tokamak. These simulations use a nonlinear 3D reduced-MHD
fluid model and the JOREK code. During the initial period where the EC driven
current grows and spreads throughout the magnetic island, it is not a function
of the magnetic flux. However, once it has reached a steady-state, it should be
a flux function. We demonstrate numerically that if sufficiently resolved
toroidally, the steady-state EC driven current becomes approximately a flux
function. We discuss the physics of this early period of EC evolution and its
impact on the size of the magnetic island.


title:
Qualitative Analysis and Numerical Simulation of Equations of the
  Standard Cosmological Model: $\Lambda\not=0$

abstract:
  On the basis of qualitative analysis of the system of differential equations
of the standard cosmological model it is shown that in the case of zero
cosmological constant this system has a stable center corresponding to zero
values of potential and its derivative at infinity. Thus, the cosmological
model based on single massive classical scalar field in infinite future would
give a flat Universe. The carried out numerical simulation of the dynamic
system corresponding to the system of Einstein - Klein - Gordon equations
showed that at great times of the evolution the invariant cosmological
acceleration has an oscillating character and changes from $-2$ (braking), to
$+1$ (acceleration). Average value of the cosmological acceleration is negative
and is equal to $-1/2$. Oscillations of the cosmological acceleration happen on
the background of rapidly falling Hubble constant. In the case of nonzero value
of the cosmological constant depending on its value there are possible three
various qualitative behavior types of the dynamic system on 2-dimensional plane
$(\Phi,\dot{\Phi})$, which correspond either to zero attractive focus or to
stable attractive knot with zero values of the potential and its derivative.
Herewith the system asymptotically enters the secondary inflation. Carried out
numerical simulation showed that at cosmological constant $\Lambda<m^2
3\cdot10^{-8}$ the macroscopic value of the cosmological acceleration behaves
itself similar to the case $\Lambda=0$, i.e. in the course of the cosmological
evolution there appears a lasting stage when this value is close to $-1/2$
which corresponds to non-relativistic equation of state. In this article, the
results of qualitative and numerical analysis, obtained in Yu. Ignat'ev,
arXiv:1609.00745 [gr-qc], common to the case of a non-zero cosmological term.


title: The orthogonal character table of SL2(q)

abstract:
  The rational invariants of the SL_2(q)-invariant quadratic forms on the real
irreducible representations are determined. There is still one open question
(see Remark 6.5) if q is an even square.


title:
Optimal Error Estimates of Conservative Local Discontinuous Galerkin
  Method for Nonlinear Schr\"odinger Equation

abstract:
  In this paper, we propose a conservative local discontinuous Galerkin method
for one-dimensional nonlinear Schr\"odinger equation. By using special
upwind-biased numerical fluxes, we establish the optimal rate of convergence
$\mathcal O(h^{k+1})$, with polynomial of degree $k$ and grid size $h$.
Meanwhile, we show that this method preserves the charge conservation law and
thus we call it a conservative local discontinuous Galerkin method. Numerical
experiments verify our theoretical result.


title:
Kinematic analysis of a 3-UPU parallel Robot using the
  Ostrowski-Homotopy Continuation

abstract:
  The direct kinematics analysis is the foundation of implementation of real
world application of parallel manipulators. For most parallel manipulators the
direct kinematics is challenging. In this paper, for the first time a fast and
efficient Homotopy Continuation Method, called the Ostrowski Homotopy
continuation method has been implemented to solve the direct and inverse
kinematics problem of the parallel manipulators. This method has advantage over
conventional numerical iteration methods, which is not rely on the initial
values and is more efficient than other continuation method and it can find all
solutions of equations without divergence just by changing auxiliary Homotopy
function. Numerical example and simulation was done to solve the direct
kinematic problem of the 3-UPU parallel manipulator that leads to 16 real
solutions. Results obviously reveal the fastness and effectiveness of this
method than the conventional Homotopy continuation methods such as Newton
Homotopy. The results shows that the Ostrowski-Homotopy reduces computation
time up to 80-97 % with more accuracy in solutions in comparison with the
Newton Homotopy.


title: Low-dimensional firing rate dynamics of spiking neuron networks

abstract:
  Starting from a spectral expansion of the Fokker-Plank equation for the
membrane potential density in a network of spiking neurons, a low-dimensional
dynamics of the collective firing rate is derived. As a result a $n$-order
ordinary differential equation for the network activity can be worked out by
taking into account the slowest $n$ modes of the expansion. The resulting
low-dimensional dynamics naturally takes into account the strength of the
synaptic couplings under the hypothesis of a not too fast changing membrane
potential density. By considering only the two slowest modes, the firing rate
dynamics is equivalent to the one of a damped oscillator in which the angular
frequency and the relaxation time are state-dependent. The presented results
apply to a wide class of networks of one-compartment neuron models.


title:
ThCr2Si2-type Ru-based superconductors LaRu2M2 (M = P and As): An
  ab-initio investigation

abstract:
  ThCr2Si2-type Ru-based superconductors LaRu2P2 and LaRu2As2 with Tc ~ 4 K and
7.8 K respectively have been reported very recently. Using the first principles
method we investigate the details physical and superconducting properties
including the structural properties, electronic properties, elastic properties
and Thermodynamic properties of these newly discovered superconductors. Our
investigated lattice parameters accord well with the experimental result. The
analysis of the electronic band structure and density of states (DOS) indicates
the metallic nature of both the compounds emerges from the La and Ru and the
study of chemical bonding implies that a mixture of covalent, ionic and
metallic bonds exist in both the compounds. The study of the mechanical
properties revels that LaRu2P2 is brittle in nature while LaRu2As2 demonstrates
the ductile nature and both the compounds show anisotropic characteristics.
Finally we determine the Debye temperature and details superconducting
parameters indicating that both the compounds under study are phonon-mediated
medium coupled BCS superconductors.


title:
Generation of mechanical force by grafted polyelectrolytes in an
  electric field. Application to polyelectrolyte-based nano-devices

abstract:
  We analyze theoretically and by means of molecular dynamics (MD) simulations
the generation of mechanical force by a polyelectrolyte (PE) chain grafted to a
plane. The PE is exposed to an external electric field that favors its
adsorption on the plane. The free end of the chain is linked to a deformable
target body. Varying the field one can alter the length of the non-adsorbed
part of the chain. This entails variation of the deformation of the target body
and hence variation of the arising in the body force. Our theoretical
predictions for the generated force are in a very good agreement with the MD
data. Using the developed theory for the generated force we study the
effectiveness of possible PE-based nano-vices, comprised of two clenching
planes connected by PEs and exposed to an external electric field. We exploit
Cundall-Struck solid friction model to describe the friction between a particle
and the clenching planes. We compute the self-diffusion coefficient of a
clenched particle and show that it drastically decreases even in weak applied
fields. This demonstrates the efficacy of the PE-based nano-vices, which may be
a a possible alternative to the existing nano-tube nano-tweezers and optical
tweezers.


title:
Particle manipulation beyond the diffraction limit using structured
  super-oscillating light beams

abstract:
  The diffraction limited resolution of light focused by a lens was derived in
1873 by Ernst Abbe. Later in 1952, a method to reach sub-diffraction light
spots was proposed by modulating the wavefront of the focused beam. In a
related development, super-oscillating functions, i.e. band limited functions
that locally oscillate faster than their highest Fourier component, were
introduced and experimentally applied for super-resolution microscopy. Up till
now, only simple Gaussian-like sub-diffraction spots were used. Here we show
that the amplitude and phase profile of these sub-diffraction spots can be
arbitrarily controlled. In particular we utilize Hermite-Gauss, Laguerre-Gauss
and Airy functions to structure super-oscillating beams with sub-diffraction
lobes. These structured beams are then used for high resolution trapping and
manipulation of nanometer-sized particles. The trapping potential provides
unprecedented localization accuracy and stiffness, significantly exceeding
those provided by standard diffraction limited beams.


title: Gibbs partitions: the convergent case

abstract:
  We study Gibbs partitions that typically form a unique giant component. The
remainder is shown to converge in total variation toward a
Boltzmann-distributed limit structure. We demon- strate how this setting
encompasses arbitrary weighted assemblies of tree-like combinatorial
structures. As an application, we establish smooth growth along lattices for
small block-stable classes of graphs. Random graphs with n vertices from such
classes are shown to form a giant connected component. The small fragments may
converge toward different Poisson Boltzmann limit graphs, depending along which
lattice we let n tend to infinity. Since proper addable minor-closed classes of
graphs belong to the more general family of small block-stable classes, this
recovers and generalizes results by McDiarmid (2009).


title:
An analytical method for error analysis of GRACE-like missions based on
  spectral analysis

abstract:
  The aim of this paper is to present an analytical relationship between the
power spectral density of GRACE-like mission measurements and the accuracies of
the gravity field coefficients mainly from the point of view of theory of
signal and system, which indicates the one-to-one correspondence between
spherical harmonic error degree variances and frequencies of the measurement
noise. In order to establish this relationship, the average power of the errors
due to gravitational acceleration difference and the relationship between
perturbing forces and range-rate perturbations are derived, based on the
orthogonality property of associated Legendre functions and the linear orbit
perturbation theory, respectively. This method provides a physical insight into
the relation between mission parameters and scientific requirements. By taking
GRACE-FO as the object of research, the effects of sensor noises and time
variable gravity signals are analyzed. If LRI measurements are applied, a
mission goal with a geoid accuracy of 7.4 cm at a spatial resolution of 101 km
is reachable, whereas if the KBR measurement error model is applied, a mission
goal with a geoid accuracy of 10.2 cm at a spatial resolution of 125 km is
reachable. Based on the discussion of the spectral matching of instrument
accuracies, an improvement in accuracy of accelerometers is necessary for the
match between the range errors and accelerometer noises in the future mission.
Temporal aliasing caused by the time variable gravity signals is also discussed
by this method.


title:
Implicit monotone difference methods for scalar conservation laws with
  source terms

abstract:
  In this article, a concept of implicit methods for scalar conservation laws
in one or more spatial dimensions allowing also for source terms of various
types is presented. This material is a significant extension of previous work
of the first author [3]. Implicit notions are developed that are centered
around a monotonicity criterion. We demonstrate a connection between a
numerical scheme and a discrete entropy inequality, which is based on a
classical approach by Crandall and Majda. Additionally, three implicit methods
are investigated using the developed notions. Next, we conduct a convergence
proof which is not based on a classical compactness argument. Finally, the
theoretical results are confirmed by various numerical tests.


title: Astrophysical Neutrinos and Flavor Evolution With Self Interaction

abstract:
  In a core collapse supernova, collective oscillations of neutrinos emitted by
the proto-neutron star significantly modifies the partition of energy between
different flavors in a way which is potentially important for the
nucleosynthesis of heavy elements at the outer layers. As the outcome of
collective oscillations depends nonlinearly on the chosen initial conditions
proto-neutron star, their systematical study across the proto-neutron star
model space may provide answers to some key questions.


title:
Tidal deformability of neutron and hyperon star with relativistic mean
  field equations of state

abstract:
  We systematically study the tidal deformability for neutron and hyperon stars
using relativistic mean field (RMF) equations of state (EOSs). The tidal effect
plays an important role during the early part of the evolution of compact
binaries. Although, the deformability associated with the EOSs has a small
correction, it gives a clean gravitational wave signature in binary inspiral.
These are characterized by various love numbers kl (l=2, 3, 4), that depend on
the EOS of a star for a given mass and radius. The tidal effect of star could
be efficiently measured through advanced LIGO detector from the final stages of
inspiraling binary neutron star (BNS) merger.


title:
Towards the effectiveness of Deep Convolutional Neural Network based
  Fast Random Forest Classifier

abstract:
  Deep Learning is considered to be a quite young in the area of machine
learning research, found its effectiveness in dealing complex yet high
dimensional dataset that includes but limited to images, text and speech etc.
with multiple levels of representation and abstraction. As there are a plethora
of research on these datasets by various researchers , a win over them needs
lots of attention. Careful setting of Deep learning parameters is of paramount
importance in order to avoid the overfitting unlike conventional methods with
limited parameter settings. Deep Convolutional neural network (DCNN) with
multiple layers of compositions and appropriate settings might be is an
efficient machine learning method that can outperform the conventional methods
in a great way. However, due to its slow adoption in learning, there are also
always a chance of overfitting during feature selection process, which can be
addressed by employing a regularization method called dropout. Fast Random
Forest (FRF) is a powerful ensemble classifier especially when the datasets are
noisy and when the number of attributes is large in comparison to the number of
instances, as is the case of Bioinformatics datasets. Several publicly
available Bioinformatics dataset, Handwritten digits recognition and Image
segmentation dataset are considered for evaluation of the proposed approach.
The excellent performance obtained by the proposed DCNN based feature selection
with FRF classifier on high dimensional datasets makes it a fast and accurate
classifier in comparison the state-of-the-art.


title:
Ground-state energy and excitation spectrum of the Lieb-Liniger model :
  accurate analytical results and conjectures about the exact solution

abstract:
  We study the ground-state properties and excitation spectrum of the
Lieb-Liniger model, i.e. the one-dimensional Bose gas with repulsive contact
interactions. We solve the Bethe-Ansatz equations in the thermodynamic limit by
using an analytic method based on a series expansion on orthogonal polynomials
developed in \cite{Ristivojevic} and push the expansion to an unprecedented
order. By a careful analysis of the mathematical structure of the series
expansion, we make a conjecture for the analytic exact result at zero
temperature and show that the partially resummed expressions thereby obtained
compete with accurate numerical calculations. This allows us to evaluate the
density of quasi-momenta, the ground-state energy, the local two-body
correlation function and Tan's contact. Then, we study the two branches of the
excitation spectrum. Using a general analysis of their properties and
symmetries, we obtain novel analytical expressions at arbitrary interaction
strength which are found to be extremely accurate in a wide range of
intermediate to strong interactions.


title: Stellar populations in the bulges of isolated galaxies

abstract:
  We present photometry and long-slit spectroscopy for 12 S0 and spiral
galaxies selected from the Catalogue of Isolated Galaxies. The structural
parameters of the sample galaxies are derived from the Sloan Digital Sky Survey
i-band images by performing a two-dimensional photometric decomposition of the
surface brightness distribution. This is assumed to be the sum of the
contribution of a S\`ersic bulge, an exponential disc, and a Ferrers bar
characterized by elliptical and concentric isophotes with constant ellipticity
and position angles. The rotation curves and velocity dispersion profiles of
the stellar component are measured from the spectra obtained along the major
axis of galaxies. The radial profiles of the H{\beta}, Mg and Fe line-strength
indices are derived too. Correlations between the central values of the Mg 2
and Fe line-strength indices and the velocity dispersion are found. The mean
age, total metallicity and total {\alpha}/Fe enhancement of the stellar
population in the centre and at the radius where the bulge gives the same
contribution to the total surface brightness as the remaining components are
obtained using stellar population models with variable element abundance
ratios. We identify intermediate-age bulges with solar metallicity and old
bulges with a large spread in metallicity. Most of the sample bulges display
super-solar {\alpha}/Fe enhancement, no gradient in age and negative gradients
of metallicity and {\alpha}/Fe enhancement. These findings support a formation
scenario via dissipative collapse where environmental effects are remarkably
less important than in the assembly of bulges of galaxies in groups and
clusters.


title:
Classification of nonlinear boundary conditions for 1D nonconvex
  Hamilton-Jacobi equations

abstract:
  We study Hamilton-Jacobi equations in [0, +$\infty$) of evolution type with
nonlinear boundary conditions of Neumann type in the case where the Hamiltonian
is non necessarily convex with respect to the gradient variable. In this paper,
we give two main results. First, we prove a classification of boundary
condition result for a nonconvex, coercive Hamiltonian, in the spirit of the
flux-limited formulation for quasi-convex Hamilton-Jacobi equations on networks
recently introduced by Imbert and Monneau. Second, we give a comparison
principle for a nonconvex and noncoercive Hamiltonian where the boundary
condition can have flat parts.


title: Reliability of universal decoding based on vector-quantized codewords

abstract:
  Motivated by applications of biometric identification and content
identification systems, we consider the problem of random coding for channels,
where each codeword undergoes lossy compression (vector quantization), and
where the decoder bases its decision only on the compressed codewords and the
channel output, which is in turn, the channel's response to the transmission of
an original codeword, before compression. For memoryless sources and memoryless
channels with finite alphabets, we propose a new universal decoder and analyze
its error exponent, which improves on an earlier result by Dasarathy and Draper
(2011), who used the classic maximum mutual information (MMI) universal
decoder. Further, we show that our universal decoder provides the same error
exponent as that of the optimal, maximum likelihood (ML) decoder, at least as
long as all single-letter transition probabilities of the channel are positive.
We conjecture that the same argument remains true even without this positivity
condition.


title: On p-local Topological Automorphic Forms for $U(1,1;\mathbb{Z}[i])$

abstract:
  We present a new flavor of TAF-type (co)homology theories, which are p-local
of height two and based on the isometry group of the odd unimodular hermitian
lattice of signature (1,1) over the Gaussian integers. Using a suitable family
of hyperelliptic curves, we explicitly construct a genus to automorphic forms,
prove an integrality statement and verify Landweber's criterion.


title: Approachability of convex sets in generalized quitting games

abstract:
  We consider Blackwell approachability, a very powerful and geometric tool in
game theory, used for example to design strategies of the uninformed player in
repeated games with incomplete information. We extend this theory to
"generalized quitting games" , a class of repeated stochastic games in which
each player may have quitting actions, such as the Big-Match. We provide three
simple geometric and strongly related conditions for the weak approachability
of a convex target set. The first is sufficient: it guarantees that, for any
fixed horizon, a player has a strategy ensuring that the expected time-average
payoff vector converges to the target set as horizon goes to infinity. The
third is necessary: if it is not satisfied, the opponent can weakly exclude the
target set. In the special case where only the approaching player can quit the
game (Big-Match of type I), the three conditions are equivalent and coincide
with Blackwell's condition. Consequently, we obtain a full characterization and
prove that the game is weakly determined-every convex set is either weakly
approachable or weakly excludable. In games where only the opponent can quit
(Big-Match of type II), none of our conditions is both sufficient and necessary
for weak approachability. We provide a continuous time sufficient condition
using techniques coming from differential games, and show its usefulness in
practice, in the spirit of Vieille's seminal work for weak
approachability.Finally, we study uniform approachability where the strategy
should not depend on the horizon and demonstrate that, in contrast with
classical Blackwell approacha-bility for convex sets, weak approachability does
not imply uniform approachability.


title: Plasmonic Photothermal Therapy in Third and Fourth Biological Windows

abstract:
  The recently reported 3rd and 4th biological transparency windows located
respectively at 1.6-1.9um and 2.1-2.3um promise deeper tissue penetration and
reduced collateral photodamage, yet they haven't been utilized in photothermal
therapy applications. Nanoparticle based plasmonic photothermal therapy poses a
nontrivial optimization problem in which the light absorption efficiency of the
nanoparticle has to be maximized subject to various constraints that are
imposed by application environment. Upscaling the typical absorber-dominant
nanoparticle designs (rod, sphere etc.) that operate in the 1st and 2nd
transparency windows is not a viable option as their size gets prohibitively
large for cell intrusion and they become scatterer-dominant. The present study
addresses this issue and suggests a versatile approach for designing both
lithography based and self-assembling absorber dominant nanostructures for the
new transparency windows, while keeping their size relatively small. The
proposed nanoparticles demonstrate up to 40% size reduction and 2-fold increase
in absorption efficiency compared to the conventional nanobar design. The
overall photothermal performance per nanoparticle in the 4th window is boosted
up by 250% compared to the 2nd window.

categories: physics.bio-ph physics.comp-ph physics.med-ph physics.optics


title: On the representation of friable integers by linear forms

abstract:
  Let $P^+(n)$ denote the largest prime of the integer $n$. Using the
\begin{align*}\Psi\_{F\_1\cdots
F\_t}\left(\mathcal{K}\cap[-N,N]^d,N^{1/u}\right):=\\#\left\{\mathcal{K}\in
{\mathbf{N}}\cap[-N,N]^d:\vphantom{P^+(F\_1(\boldsymbol{n})\cdots
F\_t(\boldsymbol{n}))\leq N^{1/u}}\right.\left.P^+(F\_1(\boldsymbol{n})\cdots
F\_t(\boldsymbol{n}))\leq N^{1/u}\right\}\end{align*} where
$(F\_1,\ldots,F\_t)$ is a system of affine-linear forms of
$\mathbf{Z}[X\_1,\ldots,X\_d]$ no two of which are affinely related and
$\mathcal{K}$ is a convex body. This improves upon Balog, Blomer, Dartyge and
Tenenbaum's work~\cite{BBDT12} in the case of product of linear forms.


title: A sum-shuffle formula for zeta values in Tate algebras

abstract:
  We prove a sum-shuffle formula for multiple zeta values in Tate algebras (in
positive characteristic), introduced in \cite{PEL3}.This follows from an analog
result for double twisted power sums, implying that an ${\mathbb{F}\_p$-vector
space generated by multiple zeta values in Tate algebras is an
${\mathbb{F}\_p$-algebra.


title: A Nondeterministic Model for Abstract Geometrical Computation

abstract:
  A signal machine is an abstract geometrical model for computation, proposed
as an extension to the one-dimensional cellular automata, in which discrete
time and space of cellular automata is replaced with continuous time and space
in signal machine. A signal machine is defined as a set of meta-signals and a
set of rules. A signal machine starts from an initial configuration which is a
set of moving signals. Signals are moving in space freely until a collision.
Rules of signal machine specify what happens after a collision, or in other
words, specify out-coming signals for each set of colliding signals. Originally
signal machine is defined by its rule as a deterministic machine. In this
paper, we introduce the concept of non-deterministic signal machine, which may
contain more than one defined rule for each set of colliding signals. We show
that for a specific class of nondeterministic signal machines, called
k-restricted nondeterministic signal machine, there is a deterministic signal
machine computing the same result as the nondeterministic one, on any given
initial configuration. k-restricted nondeterministic signal machine is a
nondeterministic signal machine which accepts an input iff produces a special
accepting signal, which have at most two nondeterministic rule for each
collision, and at most k collisions before any acceptance.


title:
SNR radio spectral index distribution and its correlation with
  polarization: a case study of Lupus Loop

abstract:
  We use radio-continuum all-sky surveys at 1420 and 408 MHz with the aim to
investigate properties of the Galactic radio source Lupus Loop. The survey data
at 1435 MHz, with the linear polarization of the southern sky, is also used. We
calculate properties of this supernova remnant: the brightness temperature,
surface brightness and radio spectral index. For determining borders and
calculation of its properties, we use the method we have developed. The
non-thermal nature of its radiation is confirmed. The distribution of spectral
index over its area is also given. A significant correlation between the radio
spectral index distribution and the corresponding polarized intensity
distribution inside the loop borders is found, indicating that the polarization
maps could provide us information about the distribution of interstellar
medium, and thus could represent one additional way to search for new Galactic
loops.


title:
Squeezed Bispectrum in the $\delta N$ Formalism: Local Observer Effect
  in Field Space

abstract:
  The prospects of future galaxy surveys for non-Gaussianity measurements call
for the development of robust techniques for computing the bispectrum of
primordial cosmological perturbations. In this paper, we propose a novel
approach to the calculation of the squeezed bispectrum in multiple-field
inflation. With use of the $\delta N$ formalism, our framework sheds new light
on the recently pointed out difference between the squeezed bispectrum for
global observers and that for local observers, while allowing one to calculate
both. For local observers in particular, the squeezed bispectrum is found to
vanish in single-field inflation. Furthermore, our framework allows one to go
beyond the near-equilateral ("small hierarchy") limit, and to automatically
include intrinsic non-Gaussianities that do not need to be calculated
separately. The explicit computational programme of our method is given and
illustrated with a few examples.


title: The density of superconductivity in the bulk regime

abstract:
  In the asymptotic limit of a large Ginzburg-Landau parameter, we give a new
asymptotic formula for the $L^2$-norm of the Ginzburg-Landau order parameter.
The formula is valid in the bulk regime where the intensity of the applied
magnetic field is of the same order as the Ginzburg-Landau parameter and
strictly below the second critical field. Our formula complements the
celebrated one of Sandier-Serfaty for the $L^4$-norm.


title: Graph-Theoretic Approaches to Two-Sender Index Coding

abstract:
  Consider a communication scenario over a noiseless channel where a sender is
required to broadcast messages to multiple receivers, each having side
information about some messages. In this scenario, the sender can leverage the
receivers' side information during the encoding of messages in order to reduce
the required transmissions. This type of encoding is called index coding. In
this paper, we study index coding with two cooperative senders, each with some
subset of messages, and multiple receivers, each requesting one unique message.
The index coding in this setup is called two-sender unicast index coding
(TSUIC). The main aim of TSUIC is to minimize the total number of transmissions
required by the two senders. Based on graph-theoretic approaches, we prove that
TSUIC is equivalent to single-sender unicast index coding (SSUIC) for some
special cases. Moreover, we extend the existing schemes for SSUIC, viz., the
cycle-cover scheme, the clique-cover scheme, and the local-chromatic scheme to
the corresponding schemes for TSUIC.


title: The Power of Data Reduction for Matching

abstract:
  Finding maximum-cardinality matchings in undirected graphs is arguably one of
the most central graph primitives. For $m$-edge and $n$-vertex graphs, it is
well-known to be solvable in $O(m\sqrt{n})$ time; however, for several
applications this running time is still too slow. We investigate how
linear-time (and almost linear-time) data reduction (used as preprocessing) can
alleviate the situation. More specifically, we focus on (almost) linear-time
kernelization. We start a deeper and systematic study both for general graphs
and for bipartite graphs. Our data reduction algorithms easily comply (in form
of preprocessing) with every solution strategy (exact, approximate, heuristic),
thus making them attractive in various settings.


title:
Computing the joint distribution of the total tree length across loci in
  populations with variable size

abstract:
  In recent years, a number of methods have been developed to infer complex
demographic histories, especially historical population size changes, from
genomic sequence data. Coalescent Hidden Markov Models have proven to be
particularly useful for this type of inference. Due to the Markovian structure
of these models, an essential building block is the joint distribution of local
genealogical trees, or statistics of these genealogies, at two neighboring loci
in populations of variable size. Here, we present a novel method to compute the
marginal and the joint distribution of the total length of the genealogical
trees at two loci separated by at most one recombination event for samples of
arbitrary size. To our knowledge, no method to compute these distributions has
been presented in the literature to date. We show that they can be obtained
from the solution of certain hyperbolic systems of partial differential
equations. We present a numerical algorithm, based on the method of
characteristics, that can be used to efficiently and accurately solve these
systems and compute the marginal and the joint distributions. We demonstrate
its utility to study the properties of the joint distribution. Our flexible
method can be straightforwardly extended to handle an arbitrary fixed number of
recombination events, to include the distributions of other statistics of the
genealogies as well, and can also be applied in structured populations.


title:
Preference Between Allocentric and Egocentric 3D Manipulation in a
  Locally Coupled Configuration

abstract:
  We study user preference between allocentric and egocentric 3D manipulation
on mobile devices, in a configuration where the motion of the device is applied
to an object displayed on the device itself. We first evaluate this preference
for translations and for rotations alone, then for full 6-DOF manipulation. We
also investigate the role of contextual cues by performing this experiment in
different 3D scenes. Finally, we look at the specific influence of each
manipulation axis. Our results provide guidelines to help interface designers
select an appropriate default mapping in this locally coupled configuration.


title: Piecewise quantile autoregressive modeling for nonstationary time series

abstract:
  We develop a new methodology for the fitting of nonstationary time series
that exhibit nonlinearity, asymmetry, local persistence and changes in location
scale and shape of the underlying distribution. In order to achieve this goal,
we perform model selection in the class of piecewise stationary quantile
autoregressive processes. The best model is defined in terms of minimizing a
minimum description length criterion derived from an asymmetric Laplace
likelihood. Its practical minimization is done with the use of genetic
algorithms. If the data generating process follows indeed a piecewise quantile
autoregression structure, we show that our method is consistent for estimating
the break points and the autoregressive parameters. Empirical work suggests
that the proposed method performs well in finite samples.


title:
Frustrated magnetism in the Heisenberg pyrochlore antiferromagnets
  $A$Yb$_2$$X$$_4$ ($A$ = Cd, Mg, $X$ = S, Se)

abstract:
  Our polycrystalline sample study on the Yb-based chalcogenide spinels
$A$Yb$_2$$X_4$ ($A =$ Cd, Mg, $X =$ S, Se) has revealed frustrated magnetism
due to the antiferromagnetically coupled Heisenberg spin on the pyrochlore
lattice. Our crystal electric field analysis indicates the Yb ground state has
nearly Heisenberg spins with a strong quantum character of the ground doublet.
All the materials exhibit an antiferromagnetic order at 1.4-1.8 K, much lower
temperature than the antiferromagnetic exchange coupling scale of $\sim 10$ K.
The magnetic specific heat $C_{\rm M}$ shows a $T^{3}$ dependence, indicating
the gapless feature in the Yb-based chalcogenide spinels. The magnetic entropy
change much smaller than $R$ ln 2 below the N\'{e}el temperature and the small
local magnetic field estimated from the $\mu$SR measurements strongly suggest
the significantly reduced size of the ordered moment in comparison with the
bare moment size 1.33 $\mu_{\rm B}$/Yb supporting strong fluctuations in the
commensurate and incommensurate ordered states in CdYb$_2$S$_4$ and
MgYb$_2$S$_4$, respectively.


title: Study of hot and dense nuclear matter in effective QCD model

abstract:
  In this thesis we use various effective QCD models to investigate hot and
dense nuclear matter created in heavy ion collisions. To characterize such
matter, we mainly exploit correlation functions and some of the associated
spectral properties. We explore the vector meson current-current correlation
function with and without the influence of vector interaction in
Nambu\textendash Jona-Lasinio (NJL) model and also in its Polyakov loop
extended version (PNJL). As a spectral property we have computed the dilepton
rate which is found to be enhanced in strongly interacting QGP (sQGP) as
compared to the Born rate in a weakly coupled QGP. We further consider the idea
of entanglement between the chiral and confinement dynamics through the
entangled PNJL (EPNJL) model and re-explore the vector spectral function and
the spectral property such as the dilepton production rate studied in our
earlier effort. Because of the strong entanglement, the coupling strengths run
with the temperature and chemical potential. The implications of such running
on the dilepton rate have been discussed in details. The Euclidean vector
correlator and the response of the conserved density fluctuations related with
the temporal vector correlator have also been investigated. We have considered
both the scenarios, i.e. presence and absence of the vector interaction. The
inclusion of the vector interaction also brings forth some intriguing issues in
the fluctuation of conserved density, namely the QNS. It has been discussed in
details and we try to address it using EPNJL model. We also assume the QGP to
be made of a non-interacting quarks, antiquarks and gluons and construct a
partition function which is restricted by the assumption of a color singlet
projection to conform with the $SU(3)_c$ symmetry. This type of simple quantum
statistical description exhibits very interesting features, which we have
discussed in details.


title: On $g$-Extra Connectivity of Hypercube-like Networks

abstract:
  Given a connected graph $G$ and a non-negative integer $g$, the {\em
$g$-extra connectivity} $\k_g(G)$ of $G$ is the minimum cardinality of a set of
vertices in $G$, if it exists, whose deletion disconnects $G$ and leaves each
remaining component with more than $g$ vertices. This paper focuses on the
$g$-extra connectivity of hypercube-like networks (HL-networks for short) which
includes numerous well-known topologies, such as hypercubes, twisted cubes,
crossed cubes and M\"obius cubes. All the known results suggest the equality
$\k_g(X_n)=f_n(g)$ holds, where $X_n$ is an $n$-dimensional HL-network,
$f_n(g)=n(g+1)-\frac{g(g+3)}{2}$, $n\geq 5$ and $0\leq g\leq n-3$? Some authors
also attempted to prove this equality in general. In this paper, we construct a
subfamily of an $n$-dimensional HL-network with $g$-extra connectivity greater
than $f_n(g)$ which implies that the above equality does not hold in general.
We also prove that for $n\geq 5$ and $0\leq g\leq n-3$, $\k_g(X_n)\geq f_n(g)$
always holds. This enables us to give a sufficient condition for the equality
$\k_g(X_n)=f_n(g)$, which is then used to determine the $g$-extra connectivity
of HL-networks for some small $g$ or the $g$-extra connectivity of some
particular subfamily of HL-networks. As a result, a short proof for the main
results in [Journal of Computer and System Sciences 79 (2013) 669--688].


title: Sparse principal component regression for generalized linear models

abstract:
  Principal component regression (PCR) is a widely used two-stage procedure:
principal component analysis (PCA), followed by regression in which the
selected principal components are regarded as new explanatory variables in the
model. Note that PCA is based only on the explanatory variables, so the
principal components are not selected using the information on the response
variable. In this paper, we propose a one-stage procedure for PCR in the
framework of generalized linear models. The basic loss function is based on a
combination of the regression loss and PCA loss. An estimate of the regression
parameter is obtained as the minimizer of the basic loss function with a sparse
penalty. We call the proposed method sparse principal component regression for
generalized linear models (SPCR-glm). Taking the two loss function into
consideration simultaneously, SPCR-glm enables us to obtain sparse principal
component loadings that are related to a response variable. However, a
combination of loss functions may cause a parameter identification problem, but
this potential problem is avoided by virtue of the sparse penalty. Thus, the
sparse penalty plays two roles in this method. The parameter estimation
procedure is proposed using various update algorithms with the coordinate
descent algorithm. We apply SPCR-glm to two real datasets, doctor visits data
and mouse consomic strain data. SPCR-glm provides more easily interpretable
principal component (PC) scores and clearer classification on PC plots than the
usual PCA.


title: Optimizing single microwave-photon detection: Input-Output theory

abstract:
  High fidelity microwave photon counting is an important tool for various
areas from background radiation analysis in astronomy to the implementation of
circuit QED architectures for the realization of a scalable quantum information
processor. In this work we describe a microwave photon counter coupled to a
semi-infinite transmission line. We employ input-output theory to examine a
continuously driven transmission line as well as traveling photon wave packets.
Using analytic and numerical methods, we calculate the conditions on the system
parameters necessary to optimize measurement and achieve high detection
efficiency.


title:
Flexible Dual-Connectivity Spectrum Aggregation for Decoupled Uplink and
  Downlink Access in 5G Heterogeneous Systems

abstract:
  Maintaining multiple wireless connections is a promising solution to boost
capacity in fifth-generation (5G) networks, where user equipment is able to
consume radio resources of several serving cells simultaneously and potentially
aggregate bandwidth across all of them. The emerging dual connectivity paradigm
can be regarded as an attractive access mechanism in dense heterogeneous 5G
networks, where bandwidth sharing and cooperative techniques are evolving to
meet the increased capacity requirements. Dual connectivity in the uplink
remained highly controversial, since the user device has a limited power budget
to share between two different access points, especially when located close to
the cell edge. On the other hand, in an attempt to enhance the uplink
communications performance, the concept of uplink and downlink decoupling has
recently been introduced. Leveraging these latest developments, our work
significantly advances prior art by proposing and investigating the concept of
flexible cell association in dual connectivity scenarios, where users are able
to aggregate resources from more than one serving cell. In this setup, the
preferred association policies for the uplink may differ from those for the
downlink, thereby allowing for a truly decoupled access. With the use of
stochastic geometry, the dual connectivity association regions for decoupled
access are derived and the resultant performance is evaluated in terms of
capacity gains over the conventional downlink received power access policies.