title:
Asymptotic error distribution for the Ninomiya-Victoir scheme in the
  commutative case

abstract:
  In a previous work, we proved strong convergence with order $1$ of the
Ninomiya-Victoir scheme $X^{NV}$ with time step $T/N$ to the solution $X$ of
the limiting SDE when the Brownian vector fields commute. In this paper, we
prove that the normalized error process $N \left(X - X^{NV}\right)$ converges
to an affine SDE with source terms involving the Lie brackets between the
Brownian vector fields and the drift vector field. This result ensures that the
strong convergence rate is actually $1$ when the Brownian vector fields
commute, but at least one of them does not commute with the drift vector field.
When all the vector fields commute the limit vanishes. Our result is consistent
with the fact that the Ninomiya-Victoir scheme solves the SDE in this case.


title: On the butterfly effect

abstract:
  The term "butterfly effect" means an extreme sensitivity of a dynamical
system to small perturbations: "The beating of a butterfly wing in South
America can result in the considerable change of positions and force of a
tropical cyclon in Atlantic 2 weeks later". Numerical simulations of R.Robert
show the absence of the butterfly effect in some simple flows of 2-d ideal
incompressible fluid which is a model of the atmosphere. In this work a more
complicated flow is considered. Numerical simulation demonstrates the butterfly
effect in the strongest form. The effect is robust, and the experiment is 100%
reproducible.


title: The mass accretion rate of galaxy clusters: a measurable quantity

abstract:
  We are interested in investigating the growth of structures at the nonlinear
scales of galaxy clusters from an observational perspective: we explore the
possibility of measuring the mass accretion rate of galaxy clusters from their
mass profile beyond the virial radius. We derive the accretion rate from the
mass of a spherical shell whose infall velocity is extracted from $N$-body
simulations. In the redshift range $z=[0,2]$, our prescription returns an
average mass accretion rate within $20-40 \%$ of the average rate derived from
the merger trees of dark matter haloes extracted from $N$-body simulations. Our
result suggests that measuring the mean mass accretion rate of a sample of
galaxy clusters is actually feasible, thus providing a new potential
observational test of the cosmological and structure formation models.


title:
Riemann hypothesis equivalences,Robin inequality,Lagarias criterion, and
  Riemann hypothesis

abstract:
  In this paper, we briefly review most of accomplished research in Riemann
Zeta function and Riemann hypothesis since Riemann's age including Riemann
hypothesis equivalences as well. We then make use of Robin and Lagarias'
criterions to prove Riemann hypothesis. The goal is, applying Lagarias
criterion for $n\geq 1$ since Lagarias criterion states that Riemann hypothesis
holds if and only if the inequality $\sum_{d|n}d\leq
H_{n}+\exp(H_{n})\log(H_{n})$ holds for all $n\geq 1$. Although, Robin's
criterion is applied as well. Our approach breaks up the set of natural numbers
into three main subsets. The first subset is $\{n\in \mathbb{N}| ~ 1\leq n\leq
5040\}$. The second one is $\{n\in \mathbb{N}| ~ 5041\leq n\leq 19685\}$ and
the third one is $\{n\in \mathbb{N}| ~ n\geq 19686\}$. In our proof, the third
subset for even integers is broken up into odd integer class number sets. Then,
mathematical arguments are stated for each odd integer class number set. Odd
integer class number set is introduced in this paper. Since the Lagarias
criterion holds for the first subset regarding computer aided computations, we
do prove it using both Lagarias and Robin's criterions for the second and third
subsets and mathematical arguments accompanied by a large volume of computer
language programs. It then follows that Riemann hypothesis holds as well.


title: Generation of Quantum Cluster States using Surface Acoustic Waves

abstract:
  One-way quantum computation, also known as Cluster State Quantum Computation,
provides a robust and efficient tool to perform universal quantum computation
using only single-qubit projective measurements, given a highly entangled
cluster state. The cluster-state approach to quantum computation also leads to
certain practical advantages such as robustness against errors. In this paper,
we propose a SAW-driven One-Way Quantum Computation approach that is realizable
using a mentioned architecture and elements.


title: Exact simulation of Brownian diffusions with drift admitting jumps

abstract:
  In this paper, using an algorithm based on the retrospective rejection
sampling scheme, we propose an exact simulation of a Brownian diffusion whose
drift admits several jumps. We treat explicitly and extensively the case of two
jumps, providing numerical simulations. Our main contribution is to manage the
technical diffculty due to the presence of two jumps thanks to a new explicit
expression of the transition density of the skew Brownian motion with two
semipermeable barriers and a constant drift.


title: Radio Pulsation Search and Imaging Study of SGR J1935+2154

abstract:
  We present the results obtained from imaging observations, and search for
radio pulsations towards the magnetar SGR J1935+2154 made using the Giant
Metrewave Radio Telescope, and the Ooty Radio Telescope. We present the high
resolution radio image of the supernova remnant (SNR) G57.2+0.8, which is
positionally associated with SGR J1935+2154. We did not detect significant
periodic radio pulsations from the magnetar, with 8$\sigma$ upper limits on its
flux density of 0.4, and 0.2 mJy at 326.5, and 610 MHz, respectively, for an
assumed duty cycle of 10\%. The corresponding 6$\sigma$ upper limits at the two
frequencies for any burst emission with an assumed width of 10 ms are 0.5 Jy,
and 63 mJy, respectively. No continuum radio point source was detected at the
position of SGR J1935+2154 with a 3$\sigma$ upper limit of 1.2 mJy. We also did
not detect significant diffuse radio emission in a radius of 70 arc seconds in
coincidence with the diffuse X-ray emission reported recently, with a 3$\sigma$
upper limit of 4.5 mJy. Using the archival HI spectra, we estimate the distance
of SNR G57.2+0.8 to be 11.7 $\pm$ 2.8 kpc. Based on measured HI column density
(N$_H$) along this line of sight, we argue that the magnetar could be
physically associated with SNR G57.2+0.8. Based on present data, we can not
rule out either a pulsar wind nebula or a dust scattering halo origin for the
diffuse X-ray emission seen around the magnetar.


title: Galileon Radiation from a Spherical Collapsing Shell

abstract:
  Galileon radiation in the collapse of a thin spherical shell of matter is
analyzed. In the framework of a cubic Galileon theory, we compute the field
profile produced at large distances by a short collapse, finding that the
radiated field has two peaks traveling ahead of light fronts. The total energy
radiated during the collapse follows a power law scaling with the shell's
physical width and results from two competing effects: a Vainshtein suppression
of the emission and an enhancement due to the thinness of the shell.


title:
Should We Learn Probabilistic Models for Model Checking? A New Approach
  and An Empirical Study

abstract:
  Many automated system analysis techniques (e.g., model checking, model-based
testing) rely on first obtaining a model of the system under analysis. System
modeling is often done manually, which is often considered as a hindrance to
adopt model-based system analysis and development techniques. To overcome this
problem, researchers have proposed to automatically "learn" models based on
sample system executions and shown that the learned models can be useful
sometimes. There are however many questions to be answered. For instance, how
much shall we generalize from the observed samples and how fast would learning
converge? Or, would the analysis result based on the learned model be more
accurate than the estimation we could have obtained by sampling many system
executions within the same amount of time? In this work, we investigate
existing algorithms for learning probabilistic models for model checking,
propose an evolution-based approach for better controlling the degree of
generalization and conduct an empirical study in order to answer the questions.
One of our findings is that the effectiveness of learning may sometimes be
limited.


title:
A novel route to a Hopf-bifurcation scenario in switched systems with
  dead zone

abstract:
  Planar switched system with dead-zone are analyzed. In particular, we
consider the effects of perturbation of the linear control law from purely
positional to position-velocity control. This type of perturbation leads to a
novel Hopf-like discontinuity induced bifurcation. We show that this
bifurcation leads to the creation of small scale limit cycle attractors, which
scale as the square root of the bifurcation parameter. We note that a Hopf-like
bifurcation analyzed in non-smooth systems is characterized by a linear scaling
law. We then investigate numerically a planar switched system with positional
feedback law, dead-zone and time delay in the switching function. Using the
same parameter values as for the switched system without delay in the switching
function, we show numerically a Hopf-like bifurcation scenario which matches
qualitatively and quantitatively with the scenario analyzed for the non-delayed
system.


title:
Derivations from the even parts into the odd parts for Hamiltonian
  superalgebras

abstract:
  Let $W_{\overline{1}}$ and $H_{\overline{0}}$ denote the odd parts of the
general Witt modular Lie superalgebra $W$ and the even parts of the Hamiltonian
Lie superalgebra $H$ over a field of characteristic $p>3$, respectively. We
give a torus of $H_{\overline{0}}$ and the weight space decomposition of the
special subalgebra of $W_{\overline{1}}$ with respect to the torus. By means of
the derivations of the weight 0 and three series of outer derivations from
$H_{\overline{0}}$ into $W_{\overline{1}}$, the derivations from the even parts
of Hamiltonian superalgebra to the odd parts of Witt superalgebra are
determined.


title: 3-ary Hom-Lie superalgebras induced Hom-Lie superalgebras

abstract:
  The purpose of this paper is to study the relationships between a Hom-Lie
superalgebra and its induced 3-ary-Hom-Lie superalgebra. We provide an overview
of the theory and explore the structure properties such as ideals, center,
derived series, solvability, nilpotency, central extensions, and the
cohomology.


title:
Cyclotron resonance of figure-of-eight orbits in a type-II Weyl
  semimetal

abstract:
  We study the cyclotron resonance in the electron-hole joint Fermi surface of
a type-II Weyl semimetal. In magnetic field, the electron and hole pockets
touching at the Weyl node are hybridized to form quantized Landau levels
corresponding to semiclassical 8-shaped orbits. We calculate the dynamical
conductivities for the electric fields oscillating in $x$ and $y$-directions
and find that the resonant frequencies in $x$ and $y$ differ by the factor of
two, reflecting to the figure-of-eight electron motion in the real space. The
peculiar anisotropy in the cyclotron resonance serves as a unique
characteristic of the dumbbell-like Fermi surface.


title: Discrete Deep Feature Extraction: A Theory and New Architectures

abstract:
  First steps towards a mathematical theory of deep convolutional neural
networks for feature extraction were made---for the continuous-time case---in
Mallat, 2012, and Wiatowski and B\"olcskei, 2015. This paper considers the
discrete case, introduces new convolutional neural network architectures, and
proposes a mathematical framework for their analysis. Specifically, we
establish deformation and translation sensitivity results of local and global
nature, and we investigate how certain structural properties of the input
signal are reflected in the corresponding feature vectors. Our theory applies
to general filters and general Lipschitz-continuous non-linearities and pooling
operators. Experiments on handwritten digit classification and facial landmark
detection---including feature importance evaluation---complement the
theoretical findings.


title: Projective DC Motor Control Under Disturbance Torques

abstract:
  In this study, we will present the design of a linear DC motor controller by
projective linear qudratic servo feedback (P-LQSF) and analyze its stability
through the notion of input to state stability theory. The projective control
approach allows one to design an output feedback controller which approximates
the eigenspectrum of a full state feedback closed loop. The performance and
stability of the controllers will be analyzed both theoretically and through
simulation. Apart from basic linear stability, the theoretical analysis will
involve the stability of the closed loop against the disturbance torques by
reflecting the closed loop as a system with the disturbance torque appearing as
an input. Knowing this fact, the input-to-state stability concept is utilized
as a disturbance to state stability approach and the designs are analyzed
accordingly. The overall products are demonstrated by MATLAB based simulations.


title:
Solving Systems of Random Quadratic Equations via Truncated Amplitude
  Flow

abstract:
  This paper presents a new algorithm, termed \emph{truncated amplitude flow}
(TAF), to recover an unknown vector $\bm{x}$ from a system of quadratic
equations of the form $y_i=|\langle\bm{a}_i,\bm{x}\rangle|^2$, where
$\bm{a}_i$'s are given random measurement vectors. This problem is known to be
\emph{NP-hard} in general. We prove that as soon as the number of equations is
on the order of the number of unknowns, TAF recovers the solution exactly (up
to a global unimodular constant) with high probability and complexity growing
linearly with both the number of unknowns and the number of equations. Our TAF
approach adopts the \emph{amplitude-based} empirical loss function, and
proceeds in two stages. In the first stage, we introduce an
\emph{orthogonality-promoting} initialization that can be obtained with a few
power iterations. Stage two refines the initial estimate by successive updates
of scalable \emph{truncated generalized gradient iterations}, which are able to
handle the rather challenging nonconvex and nonsmooth amplitude-based objective
function. In particular, when vectors $\bm{x}$ and $\bm{a}_i$'s are
real-valued, our gradient truncation rule provably eliminates erroneously
estimated signs with high probability to markedly improve upon its untruncated
version. Numerical tests using synthetic data and real images demonstrate that
our initialization returns more accurate and robust estimates relative to
spectral initializations. Furthermore, even under the same initialization, the
proposed amplitude-based refinement outperforms existing Wirtinger flow
variants, corroborating the superior performance of TAF over state-of-the-art
algorithms.


title:
Reply to comments on `Structure effects in the
  $^{15}$N($n,\gamma$)$^{16}$N radiative capture reaction from the Coulomb
  dissociation of $^{16}$N'

abstract:
  We reply to the comments (arXiv:1605.07499 [nucl-th]) on "Structure effects
in the $^{15}$N($n,\gamma$)$^{16}$N radiative capture reaction from the Coulomb
dissociation of $^{16}$N". We have investigated the issue of "energy dependence
of branching ratios" and believe that this energy dependence is due to the
proper inclusion of the non-resonant continuum in the post-form reaction
theory. Interestingly, this energy dependence is sensitive to the relative
orbital angular momentum content of the state. We reiterate that we have
attempted to resolve the discrepancy in the spectroscopic factors of low-lying
$^{16}$N levels and that it is essential to know the low energy
$^{15}$N($n,\gamma$)$^{16}$N capture cross section, especially below 0.25 MeV.


title: Quantum-polarization state tomography

abstract:
  We propose and demonstrate a method for quantum-state tomography of qudits
encoded in the quantum polarization of $N$-photon states. This is achieved by
distributing $N$ photons nondeterministically into three paths and their
subsequent projection, which for $N=1$ is equivalent to measuring the Stokes
(or Pauli) operators. The statistics of the recorded $N$-fold coincidences
determines the unknown $N$-photon polarization state uniquely. The proposed,
fixed setup manifestly rules out any systematic measurement errors due to
moving components and allows for simple switching between tomography of
different states, which makes it ideal for adaptive tomography schemes.


title: A counterexample to Thiagarajan's conjecture on regular event structures

abstract:
  We provide a counterexample to a conjecture by Thiagarajan (1996 and 2002)
that regular event structures correspond exactly to event structures obtained
as unfoldings of finite 1-safe Petri nets. The same counterexample is used to
disprove a closely related conjecture by Badouel, Darondeau, and Raoult (1999)
that domains of regular event structures with bounded $\natural$-cliques are
recognizable by finite trace automata. Event structures, trace automata, and
Petri nets are fundamental models in concurrency theory. There exist nice
interpretations of these structures as combinatorial and geometric objects.
Namely, from a graph theoretical point of view, the domains of prime event
structures correspond exactly to median graphs; from a geometric point of view,
these domains are in bijection with CAT(0) cube complexes.
  A necessary condition for both conjectures to be true is that domains of
regular event structures (with bounded $\natural$-cliques) admit a regular nice
labeling. To disprove these conjectures, we describe a regular event domain
(with bounded $\natural$-cliques) that does not admit a regular nice labeling.
Our counterexample is derived from an example by Wise (1996 and 2007) of a
nonpositively curved square complex whose universal cover is a CAT(0) square
complex containing a particular plane with an aperiodic tiling. We prove that
other counterexamples to Thiagarajan's conjecture arise from aperiodic 4-way
deterministic tile sets of Kari and Papasoglu (1999) and Lukkarila (2009).
  On the positive side, using breakthrough results by Agol (2013) and Haglund
and Wise (2008, 2012) from geometric group theory, we prove that Thiagarajan's
conjecture is true for regular event structures whose domains occur as
principal filters of hyperbolic CAT(0) cube complexes which are universal
covers of finite nonpositively curved cube complexes.


title: Extensions of the Laurent Decomposition and the spaces $A^p(\Omega)$

abstract:
  We generalize the classical Laurent decomposition in the setting of domains
$\Omega\subseteq \mathbb C$ bounded by Jordan curves. This leads us to study
the Fr\'echet spaces $A^p(\Omega)$, and their relation to the spaces
$C^p(\partial \Omega)$. In the final section, we examine the case of a non
Jordan domain $\Omega$.


title: A note on alternating minimization algorithms: Bregman frame

abstract:
  In this paper, we propose a Bregman frame for several classical alternating
minimization algorithms. In the frame, these algorithms have uniform
mathematical formulation. We also present convergence analysis for the frame
algorithm. Under the Kurdyka-Lojasiewicz property, stronger convergence is
obtained.


title:
$Z_2$ antiferromagnetic topological insulators with broken $C_4$
  symmetry

abstract:
  A two-dimensional topological insulator may arise in a centrosymmetric
commensurate N\'{e}el antiferromagnet (AF), where staggered magnetization
breaks both the elementary translation and time reversal, but retains their
product as a symmetry. Fang et al.[Phys. Rev. B 88, 085406 (2013)] proposed an
expression for a $Z_2$ topological invariant to characterize such systems.
Here, we show that this expression does not allow to detect all the existing
phases if a certain lattice symmetry is lacking. We implement numerical
techniques to diagnose topological phases of a toy Hamiltonian, and verify our
results by computing the Chern numbers of degenerate bands, and also by
explicitly constructing the edge states, thus illustrating the efficiency of
the method.


title: Asymptotic of the maximal displacement in a branching random walk

abstract:
  In this article, we study the maximal displacement in a branching random
walk. We prove that its asymptotic behaviour consists in a first almost sure
ballistic term, a negative logarithmic correction in probability and
stochastically bounded fluctuations. This result, proved by Addario-Berry and
Reed, and Hu and Shi is given here under close-to-optimal integrability
conditions. We provide simple proofs for this result, also deducing the
genealogical structure of the individuals that are close to the maximal
displacement.


title: Shadows of Kerr black holes with and without scalar hair

abstract:
  For an observer, the Black Hole (BH) shadow is the BH's apparent image in the
sky due to the gravitational lensing of nearby radiation, emitted by an
external source. A recent class of solutions dubbed Kerr BHs with scalar hair
possess smaller shadows than the corresponding Kerr BHs and, under some
conditions, novel exotic shadow shapes can arise. Thus, these hairy BHs could
potentially provide new shadow templates for future experiments such as the
Event Horizon Telescope. In order to obtain the shadows, the backward
ray-tracing algorithm is briefly introduced, followed by numerical examples of
shadows of Kerr BHs with scalar hair contrasting with the Kerr analogues.
Additionally, an analytical solution for the Kerr shadow is derived in closed
form for a ZAMO observer at an arbitrary position.


title: Privacy Odometers and Filters: Pay-as-you-Go Composition

abstract:
  In this paper we initiate the study of adaptive composition in differential
privacy when the length of the composition, and the privacy parameters
themselves can be chosen adaptively, as a function of the outcome of previously
run analyses. This case is much more delicate than the setting covered by
existing composition theorems, in which the algorithms themselves can be chosen
adaptively, but the privacy parameters must be fixed up front. Indeed, it isn't
even clear how to define differential privacy in the adaptive parameter
setting. We proceed by defining two objects which cover the two main use cases
of composition theorems. A privacy filter is a stopping time rule that allows
an analyst to halt a computation before his pre-specified privacy budget is
exceeded. A privacy odometer allows the analyst to track realized privacy loss
as he goes, without needing to pre-specify a privacy budget. We show that
unlike the case in which privacy parameters are fixed, in the adaptive
parameter setting, these two use cases are distinct. We show that there exist
privacy filters with bounds comparable (up to constants) with existing privacy
composition theorems. We also give a privacy odometer that nearly matches
non-adaptive private composition theorems, but is sometimes worse by a small
asymptotic factor. Moreover, we show that this is inherent, and that any valid
privacy odometer in the adaptive parameter setting must lose this factor, which
shows a formal separation between the filter and odometer use-cases.


title:
All-fiber generation of 29-fs pulses at 1.3-{\mu}m via Cherenkov
  radiation

abstract:
  We have experimentally demonstrated the all-fiber generation of 1.3-{\mu}m
femtosecond pulses via Cherenkov radiation (CR) from an ultrafast Er-doped
fiber laser. The experiment shows that the pulses maintain below 40 fs in the
range from 1270 to 1315 nm with multi-milliwatt average output power. The
shortest generated pulses can be as short as 29 fs. This ultrashort pulse
source in 1.3-{\mu}m window can bring the benefits to many fields such as the
bio-imaging and the ultrafast spectroscopy, and so on.


title:
State Estimation in Electric Power Systems Using Belief Propagation: An
  Extended DC Model

abstract:
  In this paper, we model an extended DC state estimation (SE) in an electric
power system as a factor graph (FG) and solve it using belief propagation (BP)
algorithm. The DC model comprises bus voltage angles as state variables, while
the extended DC model includes bus voltage angles and bus voltage magnitudes as
state variables. By applying BP to solve the SE problem in the extended DC
model, we obtain a Gaussian BP scenario for which we derive closed-form
expressions for BP messages exchanged along the FG. The performance of the BP
algorithm is demonstrated for the IEEE 14 bus test case. Finally, the
application of BP algorithm on the extended DC scenario provides significant
insights into a fundamental structure of BP equations in more complex models
such as the AC model - the topic we will investigate in our follow up work. As
a side-goal of this paper, we aim at thorough and detailed presentation on
applying BP on the SE problem in order to make the powerful BP algorithm more
accessible and applicable within the power-engineering community.


title: Fock-Goncharov coordinates for rank two Lie groups

abstract:
  Let G be a simply connected, simple, complex Lie group of rank 2. We give
explicit Fock-Goncharov coordinates for configurations of triples and
quadruples of affine flags in G. We show that the action on triples by
orientation preserving permutations corresponds to explicit quiver mutations,
and that the same holds for the flip (changing the diagonal in a
quadrilateral). This gives explicit coordinates on higher Teichmuller space,
and also coordinates for boundary-unipotent representations of 3-manifold
groups. As an application, we compute the (generic) boundary-unipotent
representations in Sp(4,C) for the figure-eight knot complement.


title: Entanglement in Algebraic Quantum Mechanics: Majorana fermion systems

abstract:
  Many-body entanglement is studied within the algebraic approach to quantum
physics in systems made of Majorana fermions. In this framework, the notion of
separability stems from partitions of the algebra of observables and properties
of the associated correlation functions, rather than on particle tensor
products. This allows obtaining a complete characterization of non-separable
Majorana fermion states. These results may find direct applications in quantum
metrology: using Majorana systems, sub-shot noise accuracy in parameter
estimations can be achieved without preliminary, resource consuming, state
entanglement operations.

categories: quant-ph cond-mat.other hep-th math-ph math.MP


title:
A General Family of Trimmed Estimators for Robust High-dimensional Data
  Analysis

abstract:
  We consider the problem of robustifying high-dimensional structured
estimation. Robust techniques are key in real-world applications which often
involve outliers and data corruption. We focus on trimmed versions of
structurally regularized M-estimators in the high-dimensional setting,
including the popular Least Trimmed Squares estimator, as well as analogous
estimators for generalized linear models and graphical models, using possibly
non-convex loss functions. We present a general analysis of their statistical
convergence rates and consistency, and then take a closer look at the trimmed
versions of the Lasso and Graphical Lasso estimators as special cases. On the
optimization side, we show how to extend algorithms for M-estimators to fit
trimmed variants and provide guarantees on their numerical convergence. The
generality and competitive performance of high-dimensional trimmed estimators
are illustrated numerically on both simulated and real-world genomics data.


title: Secure Repairable Fountain Codes

abstract:
  In this letter, we provide the construction of repairable fountain codes
(RFCs) for distributed storage systems that are information-theoretically
secure against an eavesdropper that has access to the data stored in a subset
of the storage nodes and the data downloaded to repair an additional subset of
storage nodes. The security is achieved by adding random symbols to the
message, which is then encoded by the concatenation of a Gabidulin code and an
RFC. We compare the achievable code rates of the proposed codes with those of
secure minimum storage regenerating codes and secure locally repairable codes.


title: Predictive Coarse-Graining

abstract:
  We propose a data-driven, coarse-graining formulation in the context of
equilibrium statistical mechanics. In contrast to existing techniques which are
based on a fine-to-coarse map, we adopt the opposite strategy by prescribing a
probabilistic coarse-to-fine map. This corresponds to a directed probabilistic
model where the coarse variables play the role of latent generators of the fine
scale (all-atom) data. From an information-theoretic perspective, the framework
proposed provides an improvement upon the relative entropy method and is
capable of quantifying the uncertainty due to the information loss that
unavoidably takes place during the CG process. Furthermore, it can be readily
extended to a fully Bayesian model where various sources of uncertainties are
reflected in the posterior of the model parameters. The latter can be used to
produce not only point estimates of fine-scale reconstructions or macroscopic
observables, but more importantly, predictive posterior distributions on these
quantities. Predictive posterior distributions reflect the confidence of the
model as a function of the amount of data and the level of coarse-graining. The
issues of model complexity and model selection are seamlessly addressed by
employing a hierarchical prior that favors the discovery of sparse solutions,
revealing the most prominent features in the coarse-grained model. A flexible
and parallelizable Monte Carlo - Expectation-Maximization (MC-EM) scheme is
proposed for carrying out inference and learning tasks. A comparative
assessment of the proposed methodology is presented for a lattice spin system
and the SPC/E water model.


title: Parton Distributions at a 100 TeV Hadron Collider

abstract:
  The determination of the parton distribution functions (PDFs) of the proton
will be an essential input for the physics program of a future 100 TeV hadron
collider. The unprecedented center-of-mass energy will require knowledge of
PDFs in currently unexplored kinematical regions such as the ultra low-x region
or the region of multi-TeV momentum transfers. In this contribution we briefly
summarise the studies presented in the PDF section of the upcoming report on
"Physics at a 100 TeV pp collider: Standard Model processes". First we map the
PDF kinematical coverage in the $(x,Q^2)$ plane, quantify PDF uncertainties,
and compute ratios of PDF luminosities between 100 TeV and 14 TeV. Then we show
how the extreme kinematics of such collider lead to a number of remarkable
PDF-related phenomena such as the top quark as a massless parton, an increased
role of photon-initiated processes and the possible need of PDFs with
high-energy resummation.


title: Symmetric cumulants and event-plane correlations in Pb+Pb collisions

abstract:
  The ALICE Collaboration has recently measured the correlations between
amplitudes of anisotropic flow in different Fourier harmonics, referred to as
symmetric cumulants. We derive approximate relations between symmetric
cumulants involving $v_4$ and $v_5$ and the event-plane correlations measured
by ATLAS. The validity of these relations is tested using event-by-event
hydrodynamic calculations. The corresponding results are in better agreement
with ALICE data than existing hydrodynamic predictions. We make quantitative
predictions for three symmetric cumulants which are not yet measured.


title: Isoperimetric equalities for rosettes

abstract:
  In this paper we study the isoperimetric-type equalities for rosettes, i.e.
regular closed planar curves with non-vanishing curvature. We find the exact
relations between the length and the oriented area of rosettes based on the
oriented areas of the Wigner caustic, the Constant Width Measure Set and the
Spherical Measure Set.
  We also study and find new results about the geometry of affine equidistants
of rosettes and of the union of rosettes.


title: Spaces of directed paths on pre-cubical sets

abstract:
  The spaces of directed paths on the geometric realizations of pre-cubical
sets, called also $\square$--sets, can be interpreted as the spaces of possible
executions of Higher Dimensional Automata, which are models for concurrent
computations. In this paper we construct, for a sufficiently good pre-cubical
set $K$, a CW-complex $W(K)_v^w$ that is homotopy equivalent to the space of
directed paths between given vertices $v$, $w$ of $K$. This construction is
functorial with respect to $K$, and minimal among all functorial constructions.
Furthermore, explicit formulas for incidence numbers of the cells of $W(K)_v^w$
are provided.


title: Enhanced flexural wave sensing by adaptive gradient-index metamaterials

abstract:
  Increasing sensitivity and signal to noise ratios of conventional wave
sensors is an interesting topic in structural health monitoring, medical
imaging, aerospace and nuclear instrumentation. Here, we report the concept of
a gradient piezoelectric self-sensing system by integrating shunting circuitry
into conventional sensors. By tuning circuit elements properly, both the
quality and quantity of the flexural wave measurement data can be significantly
increased for new adaptive sensing applications. Through analytical, numerical
and experimental studies, we demonstrate that the metamaterial-based sensing
system (MBSS) with gradient bending stiffness can be designed by connecting
gradient negative capacitance circuits to an array of piezoelectric patches
(sensors). We further demonstrate that the proposed system can achieve more
than two orders of magnitude amplification of flexural wave signals to overcome
the detection limit. This research encompasses fundamental advancements in the
MBSS with improved performance and functionalities, and will yield significant
advances for a range of applications.


title: On singular Fano varieties with a divisor of Picard number one

abstract:
  In this paper we study the geometry of mildly singular Fano varieties on
which there is an effective prime divisor of Picard number one. Afterwards, we
address the case of toric varieties. Finally, we treat the lifting of extremal
contractions to universal covering spaces in codimension 1.


title: Efficient Multiple Line-Based Intra Prediction for HEVC

abstract:
  Traditional intra prediction usually utilizes the nearest reference line to
generate the predicted block when considering strong spatial correlation.
However, this kind of single line-based method does not always work well due to
at least two issues. One is the incoherence caused by the signal noise or the
texture of other object, where this texture deviates from the inherent texture
of the current block. The other reason is that the nearest reference line
usually has worse reconstruction quality in block-based video coding. Due to
these two issues, this paper proposes an efficient multiple line-based intra
prediction scheme to improve coding efficiency. Besides the nearest reference
line, further reference lines are also utilized. The further reference lines
with relatively higher quality can provide potential better prediction. At the
same time, the residue compensation is introduced to calibrate the prediction
of boundary regions in a block when we utilize further reference lines. To
speed up the encoding process, this paper designs several fast algorithms.
Experimental results show that, compared with HM-16.9, the proposed fast search
method achieves 2.0% bit saving on average and up to 3.7%, with increasing the
encoding time by 112%.


title: Overview of ISM bands and Software-defined Radio Experimentation

abstract:
  Wireless systems using low-power wireless communication protocol are rapidly
gain popularity in the license-free industrial scientific, and medical (ISM)
frequency bands. One such emerging trend in ISM frequency bands is home
automation. Historically, all the home devices were once unconnected, today are
now being connected either by a wired or wireless connection. The low-power
wireless communication protocols enable integration of all the digital home
devices into a single system and enhance end user product experience. The rapid
prototyping of these end user product using programmable radio system such as
software-defined radio (SDR) has been the game-changer in the field of home
automation. In this article, we present an overview of popular ISM bands in
different regions of the world. Furthermore, we analyze the signals from the
wireless electric switch using a software-defined radio in 433 MHz ISM band.


title:
Commutative and non-commutative bialgebras of quasi-posets and
  applications to Ehrhart polynomials

abstract:
  To any poset or quasi-poset is attached a lattice polytope, whose Ehrhart
polynomial we study from a Hopf-algebraic point of view. We use for this two
interacting bialgebras on quasi-posets. The Ehrhart polynomial defines a Hopf
algebra morphism taking its values in Q[X], we deduce from the interacting
bialgebras an algebraic proof of the duality principle, a generalization and a
new proof of a result on B-series due to Whright and Zhao, using a monoid of
characters on quasi-posets, and a generalization of Faulhaber's formula. We
also give non-commutative versions of these results: polynomials are replaced
by packed words. We obtain in particular a non-commutative duality principle.


title:
3D Stochastic Geometry Model for Large-Scale Molecular Communication
  Systems

abstract:
  Information delivery using chemical molecules is an integral part of biology
at multiple distance scales and has attracted recent interest in bioengineering
and communication. The collective signal strength at the receiver (i.e., the
expected number of observed molecules inside the receiver), resulting from a
large number of transmitters at random distances (e.g., due to mobility), can
have a major impact on the reliability and efficiency of the molecular
communication system. Modeling the collective signal from multiple diffusion
sources can be computationally and analytically challenging. In this paper, we
present the first tractable analytical model for the collective signal strength
due to randomly-placed transmitters, whose positions are modelled as a
homogeneous Poisson point process in three-dimensional (3D) space. By applying
stochastic geometry, we derive analytical expressions for the expected number
of observed molecules at a fully absorbing receiver and a passive receiver. Our
results reveal that the collective signal strength at both types of receivers
increases proportionally with increasing transmitter density. The proposed
framework dramatically simplifies the analysis of large-scale molecular systems
in both communication and biological applications.


title: Homogenization for A-quasiconvexity with variable coefficients

abstract:
  A homogenization result for a family of oscillating integral energies is
presented, where the fields under consideration are subjected to first order
linear differential constraints depending on the space variable x. The work is
based on the theory of A-quasiconvexity with variable coefficients and on
two-scale convergence techniques, and generalizes the previously obtained
results in the case in which the differential constraints are imposed by means
of a linear first order differential operator with constant coefficients. The
identification of the relaxed energy in the framework of A-quasiconvexity with
variable coefficients is also recovered as a corollary of the homogenization
result.


title:
A Light-powered, Always-On, Smart Camera with Compressed Domain Gesture
  Detection

abstract:
  In this paper we propose an energy-efficient camera-based gesture recognition
system powered by light energy for "always on" applications. Low energy
consumption is achieved by directly extracting gesture features from the
compressed measurements, which are the block averages and the linear
combinations of the image sensor's pixel values. The gestures are recognized
using a nearest-neighbour (NN) classifier followed by Dynamic Time Warping
(DTW). The system has been implemented on an Analog Devices Black Fin ULP
vision processor and powered by PV cells whose output is regulated by TI's
DC-DC buck converter with Maximum Power Point Tracking (MPPT). Measured data
reveals that with only 400 compressed measurements (768x compression ratio) per
frame, the system is able to recognize key wake-up gestures with greater than
80% accuracy and only 95mJ of energy per frame. Owing to its fully self-powered
operation, the proposed system can find wide applications in "always-on" vision
systems such as in surveillance, robotics and consumer electronics with
touch-less operation.


title: Statistical mechanics of the Huxley-Simmons model

abstract:
  The chemomechanical model of Huxley and Simmons (HS) [A. F. Huxley and R. M.
Simmons, Nature 233, 533 (1971)] provides a paradigmatic description of
mechanically induced collective conformational changes relevant in a variety of
biological contexts, from muscles power-stroke and hair cell gating to integrin
binding and hairpin unzipping. We develop a statistical mechanical perspective
on the HS model by exploiting a formal analogy with a paramagnetic Ising model.
We first study the equilibrium HS model with a finite number of elements and
compute explicitly its mechanical and thermal properties. To model kinetics, we
derive a master equation and solve it for several loading protocols. The
developed formalism is applicable to a broad range of allosteric systems with
mean-field interactions.


title: A second order minimality condition for a free-boundary problem

abstract:
  The goal of this paper is to derive in the two-dimensional case necessary and
sufficient minimality conditions in terms of the second variation for the
functional \[ v\mapsto\int_{\Omega}\big(|\nabla v|^{2}+\chi_{\{v>0\}}Q^{2}
\big)\,dx, \] introduced in a classical paper of Alt and Caffarelli. For a
special choice of $Q$ this includes water waves. The second variation is
obtained by computing the second derivative of the functional along suitable
variations of the free boundary. It is proved that the strict positivity of the
second variation gives a sufficient condition for local minimality. Also, it is
shown that smooth critical points are local minimizers in a small tubular
neighborhood of the free-boundary.


title: Spin gravitational resonance and graviton detection

abstract:
  We develop a gravitational analogue of spin magnetic resonance, called spin
gravitational resonance, whereby a gravitational wave interacts with a magnetic
field to produce a spin transition. In particular, an external magnetic field
separates the energy spin states of a spin-1/2 particle, and the presence of
the gravitational wave produces a perturbation in the components of the
magnetic field orthogonal to the gravitational wave propagation. In this
framework we test Dyson's conjecture that individual gravitons cannot be
detected. Although we find no fundamental laws preventing single gravitons
being detected with spin gravitational resonance, we show that it cannot be
used in practice, in support of Dyson's conjecture.


title: Leavitt path algebras are B\'ezout

abstract:
  Let $E$ be a directed graph, $K$ any field, and let $L_K(E)$ denote the
Leavitt path algebra of $E$ with coefficients in $K$. We show that $L_K(E)$ is
a B\'{e}zout ring, i.e., that every finitely generated one-sided ideal of
$L_K(E)$ is principal.


title:
Abundance of HOCO+ and CO2 in the outer layers of the L1544 prestellar
  core

abstract:
  The L1544 prestellar core has been observed as part of the ASAI IRAM Large
Program at 3 mm. These observations led to the detection of many complex
molecules. In this Letter, we report the detection of two lines, at 85.5 GHz
(4,0,4-3,0,3) and 106.9 GHz (5,0,5-4,0,4), respectively, of the protonated
carbon dioxide ion, HOCO+. We also report the tentative detection of the line
at 100.4 GHz (5,0,5-4,0,4) of DOCO+. The non-LTE analysis of the detected lines
shows that the HOCO+ emission originates in the external layer where
non-thermal desorption of other species has previously been observed. Its
abundance is (5 +/- 2) e-11. Modelling of the chemistry involved in the
formation and destruction of HOCO+ provides a gaseous CO2 abundance of 2e-7
(with respect to H2) with an upper limit of 2e-6.


title:
A resource-frugal probabilistic dictionary and applications in
  (meta)genomics

abstract:
  Genomic and metagenomic fields, generating huge sets of short genomic
sequences, brought their own share of high performance problems. To extract
relevant pieces of information from the huge data sets generated by current
sequencing techniques, one must rely on extremely scalable methods and
solutions. Indexing billions of objects is a task considered too expensive
while being a fundamental need in this field. In this paper we propose a
straightforward indexing structure that scales to billions of element and we
propose two direct applications in genomics and metagenomics. We show that our
proposal solves problem instances for which no other known solution scales-up.
We believe that many tools and applications could benefit from either the
fundamental data structure we provide or from the applications developed from
this structure.


title: Stochastic discs that roll

abstract:
  We study a model of rolling particles subject to stochastic fluctuations,
which may be relevant in systems of nano- or micro-scale particles where
rolling is an approximation for strong static friction. We consider the
simplest possible non-trivial system: a linear polymer of three of discs
constrained to remain in contact, and immersed in an equilibrium heat bath so
the internal angle of the polymer changes due to stochastic fluctuations. We
compare two cases: one where the discs can slide relative to each other, and
the other where they are constrained to roll, like gears. Starting from the
Langevin equations with arbitrary linear velocity constraints, we use formal
homogenization theory to derive the overdamped equations that describe the
process in configuration space only. The resulting dynamics have the formal
structure of a Brownian motion on a Riemannian or sub-Riemannian manifold,
depending on if the velocity constraints are holonomic or non-holonomic. We use
this to compute the trimer's equilibrium distribution both with, and without,
the rolling constraints. Surprisingly, the two distributions are different. We
suggest two possible interpretations of this result: either (i) dry friction
(or other dissipative, nonequilibrium forces) changes basic thermodynamic
quantities like the free energy of a system, a statement that could be tested
experimentally, or (ii) as a lesson in modeling rolling or friction more
generally as a velocity constraint when stochastic fluctuations are present. In
the latter case, we speculate there could be a "roughness" entropy whose
inclusion as an effective force could compensate the constraint and preserve
classical Boltzmann statistics. Regardless of the interpretation, our
calculation shows the word "rolling" must be used with care when stochastic
fluctuations are present.

categories: math-ph cond-mat.mes-hall cond-mat.stat-mech math.MP


title:
Near Optimal Channel Assignment for Interference Mitigation in Wireless
  Mesh Networks

abstract:
  In multi-radio multi-channel (MRMC) WMNs, interference alleviation is
affected through several network design techniques e.g., channel assignment
(CA), link scheduling, routing etc., intelligent CA schemes being the most
effective tool for interference mitigation. CA in WMNs is an NP-Hard problem,
and makes optimality a desired yet elusive goal in real-time deployments which
are characterized by fast transmission and switching times and minimal
end-to-end latency. The trade-off between optimal performance and minimal
response times is often achieved through CA schemes that employ heuristics to
propose efficient solutions. WMN configuration and physical layout are also
crucial factors which decide network performance, and it has been demonstrated
in numerous research works that rectangular/square grid WMNs outperform random
or unplanned WMN deployments in terms of network capacity, latency, and network
resilience. In this work, we propose a smart heuristic approach to devise a
near-optimal CA algorithm for grid WMNs (NOCAG). We demonstrate the efficacy of
NOCAG by evaluating its performance against the minimal-interference CA
generated through a rudimentary brute-force technique (BFCA), for the same WMN
configuration. We assess its ability to mitigate interference both,
theoretically (through interference estimation metrics) and experimentally (by
running rigorous simulations in NS-3). We demonstrate that the performance of
NOCAG is almost as good as the BFCA, at a minimal computational overhead of
O(n) compared to the exponential of BFCA.


title:
Targets, local weak $\sigma$-Gibbs measures and a generalized Bowen
  dimension formula

abstract:
  For a dynamical system, we study the set of points $\cal W$ whose orbit
approximates any chosen point at certain specified rates. Our basic setting is
that of left shift acting on topological Markov chains endowed with a local
weak Gibbs measure. Our rates of recurrence are so fast that the corresponding
set $\cal W$ has measure zero, but we obtain a generalized Bowen formula for
Carath\'eodory dimension. For the case of Markov transformations with countable
partition and big image (BI) property a Bowen-type formula is obtained for the
Hausdorff dimension of those exceptional sets. In particular, we apply our
general results to Gauss and Luroth maps, a not Bernoulli modification of Gauss
map and some inner functions. Since we only require the existence of weak Gibbs
measures we can deal with non H\"older potentials and we can also consider
intermittent systems as the Manneville-Pomeau map.


title:
Aerial image geolocalization from recognition and matching of roads and
  intersections

abstract:
  Aerial image analysis at a semantic level is important in many applications
with strong potential impact in industry and consumer use, such as automated
mapping, urban planning, real estate and environment monitoring, or disaster
relief. The problem is enjoying a great interest in computer vision and remote
sensing, due to increased computer power and improvement in automated image
understanding algorithms. In this paper we address the task of automatic
geolocalization of aerial images from recognition and matching of roads and
intersections. Our proposed method is a novel contribution in the literature
that could enable many applications of aerial image analysis when GPS data is
not available. We offer a complete pipeline for geolocalization, from the
detection of roads and intersections, to the identification of the enclosing
geographic region by matching detected intersections to previously learned
manually labeled ones, followed by accurate geometric alignment between the
detected roads and the manually labeled maps. We test on a novel dataset with
aerial images of two European cities and use the publicly available
OpenStreetMap project for collecting ground truth roads annotations. We show in
extensive experiments that our approach produces highly accurate localizations
in the challenging case when we train on images from one city and test on the
other and the quality of the aerial images is relatively poor. We also show
that the the alignment between detected roads and pre-stored manual annotations
can be effectively used for improving the quality of the road detection
results.


title: The 750 GeV diphoton excess and SUSY

abstract:
  The LHC experiments ATLAS and CMS have reported an excess in the diphoton
spectrum at \sim 750 GeV. At the same time the motivation for Supersymmetry
(SUSY) remains unbowed. Consequently, we review briefly the proposals to
explain this excess in SUSY, focusing on "pure" (N)MSSM solutions. We then
review in more detail a proposal to realize this excess within the NMSSM. In
this particular scenario a Higgs boson with mass around 750 GeV decays to two
light pseudo-scalar Higgs bosons. Via mixing with the pion these pseudo-scalars
decay into a pair of highly collimated photons, which are identified as one
photon, thus resulting in the observed signal.


title: Theano-MPI: a Theano-based Distributed Training Framework

abstract:
  We develop a scalable and extendable training framework that can utilize GPUs
across nodes in a cluster and accelerate the training of deep learning models
based on data parallelism. Both synchronous and asynchronous training are
implemented in our framework, where parameter exchange among GPUs is based on
CUDA-aware MPI. In this report, we analyze the convergence and capability of
the framework to reduce training time when scaling the synchronous training of
AlexNet and GoogLeNet from 2 GPUs to 8 GPUs. In addition, we explore novel ways
to reduce the communication overhead caused by exchanging parameters. Finally,
we release the framework as open-source for further research on distributed
deep learning


title:
The BMO-Dirichlet problem for elliptic systems in the upper-half space
  and quantitative characterizations of VMO

abstract:
  We prove that for any homogeneous, second order, constant complex coefficient
elliptic system $L$, the Dirichlet problem in $\mathbb{R}^{n}_{+}$ with
boundary data in BMO is well-posed in the class of functions $u$ with
$d\mu_u(x',t):=|\nabla u(x',t)|^2\,t\,dx'dt$ being a Carleson measure. We
establish a Fatou type theorem guaranteeing the existence of the pointwise
nontangential boundary trace for smooth null-solutions $u$ of such systems
satisfying the said Carleson measure condition. These imply that BMO can be
characterized as the collection of nontangential pointwise traces of smooth
null-solutions $u$ to the elliptic system $L$ with the property that $\mu_u$ is
a Carleson measure.
  We establish a regularity result for the BMO-Dirichlet problem in the
upper-half space: the nontangential pointwise trace of any given smooth
null-solutions of $L$ satisfying the above Carleson measure condition belongs
to Sarason's space VMO if and only if $\mu_u$ satsifies a vanishing Carleson
measure condition. Moreover, we obtain the well-posedness of the Dirichlet
problems when the boundary data are prescribed in Morrey-Campanato and
solutions are required to satisfy a vanishing Carleson measure condition of
fractional order.
  As a consequence, we characterize the space VMO as the closure in BMO of
classes of smooth functions contained in BMO within which uniform continuity
may be suitably quantified (such as the class of smooth functions satisfying a
H\"older or Lipschitz condition), improving Sarason's classical result
describing VMO as the closure in BMO of the space of uniformly continuous
functions with bounded mean oscillations.
  Finally, we show that any Calder\'on-Zygmund operator $T$ satisfying $T(1)=0$
extends as a bounded linear operator in $\mathrm{VMO}$, and characterize the
membership to $\mathrm{VMO}$ via the action of various classes of singular
integral operators.


title: Quantum Communication Between Remote Mechanical Resonators

abstract:
  Mechanical resonators represent one of the most promising candidates to
mediate the interaction between different quantum technologies, bridging the
gap between efficient quantum computation and long-distance quantum
communication. In this letter, we introduce a novel interferometric scheme
where the interaction of a mechanical resonator with input/output quantum
pulses is controlled by an independent classical drive. We design protocols for
state teleportation and direct quantum state transfer, between distant
mechanical resonators. The proposed device, feasible with state-of-the-art
technology, can serve as building block for the implementation of long-distance
quantum networks of mechanical resonators.


title:
Discussion of "Causal inference using invariant prediction:
  identification and confidence intervals" by Peters, B\"uhlmann and
  Meinshausen

abstract:
  Contribution to the discussion of the paper "Causal inference using invariant
prediction: identification and confidence intervals" by Peters, B\"uhlmann and
Meinshausen, to appear in the Journal of the Royal Statistical Society, Series
B.


title: Planets, debris and their host metallicity correlations

abstract:
  Recent observations of debris discs, believed to be made up of remnant
planetesimals, brought a number of surprises. Debris disc presence does not
correlate with the host star's metallicity, and may anti-correlate with the
presence of gas giant planets. These observations contradict both assumptions
and predictions of the highly successful Core Accretion model of planet
formation. Here we explore predictions of the alternative Tidal Downsizing (TD)
scenario of planet formation. In TD, small planets and planetesimal debris is
made only when gas fragments, predecessors of giant planets, are tidally
disrupted. We show that these disruptions are rare in discs around high
metallicity stars but release more debris per disruption than their low [M/H]
analogs. This predicts no simple relation between debris disc presence and host
star's [M/H], as observed. A detected gas giant planet implies in TD that its
predecessor fragment was not disputed, potentially explaining why DDs are less
likely to be found around stars with gas giants. Less massive planets should
correlate with DD presence, and sub-Saturn planets ($M_{p} \sim 50
\M_{\oplus}$) should correlate with DD presence stronger than sub-Neptunes
($M_{p} \leq 15 \M_{\oplus}$). These predicted planet-DD correlations will be
diluted and weakened in observations by planetary systems' long term evolution
and multi-fragment effects neglected here. Finally, although presently
difficult to observe, DDs around M dwarf stars should be more prevalent than
around Solar type stars.


title: Sharp Degree Bounds for Sum-of-Squares Certificates on Projective Curves

abstract:
  Given a real projective curve with homogeneous coordinate ring R and a
nonnegative homogeneous element f in R, we bound the degree of a nonzero
homogeneous sum-of-squares g in R such that the product fg is again a sum of
squares. Better yet, our degree bounds only depend on geometric invariants of
the curve and we show that there exist smooth curves and nonnegative elements
for which our bounds are sharp. We deduce the existence of a multiplier g from
a new Bertini Theorem in convex algebraic geometry and prove sharpness by
deforming rational Harnack curves on toric surfaces. Our techniques also yield
similar bounds for multipliers on surfaces of minimal degree, generalizing
Hilbert's work on ternary forms.


title:
Forming first-ranked early-type galaxies through hierarchical
  dissipationless merging

abstract:
  We have developed a computationally competitive N-body model of a
previrialized aggregation of galaxies in a flat LambdaCDM universe to assess
the role of the multiple mergers that take place during the formation stage of
such systems in the configuration of the remnants assembled at their centres.
An analysis of a suite of 48 simulations of low-mass forming groups (of about
1E13 solar masses) demonstrates that the gravitational dynamics involved in
their hierarchical collapse is capable of creating realistic first-ranked
galaxies without the aid of dissipative processes. Our simulations indicate
that the brightest group galaxies (BGGs) constitute a distinct population from
other group members, sketching a scenario in which the assembly path of these
objects is dictated largely by the formation of their host system. We detect
significant differences in the distribution of Sersic indices and total
magnitudes, as well as a luminosity gap between BGGs and the next brightest
galaxy that is positively correlated with the total luminosity of the parent
group. Such gaps arise from both the grow of BGGs at the expense of lesser
companions and the decrease in the relevance of second-ranked objects in equal
measure. This results in a dearth of intermediate-mass galaxies which explains
the characteristic central dip detected in their luminosity functions in
dynamically young galaxy aggregations. The fact that the basic global
properties of our BGGs define a thin mass fundamental plane strikingly similar
to that followed giant early-type galaxies in the local universe reinforces
confidence in the results obtained.


title:
A note on implementation of boundary variation diminishing algorithm to
  high-order local polynomial-based schemes

abstract:
  A novel approach for selecting appropriate reconstructions is implemented to
the hyperbolic conservation laws in the high-order local polynomial-based
framework, e.g., the discontinuous Galerkin (DG) and flux reconstruction (FR)
schemes. The high-order polynomial approximation generally fails to correctly
capture a strong discontinuity inside a cell due to the Runge phenomenon, which
is replaced by more stable approximation on the basis of a troubled-cell
indicator such as that used in the total variation bounded (TVB) limiter. This
paper examines the applicability of a new algorithm, so-called boundary
variation diminishing (BVD) reconstruction, to the weighted essentially
non-oscillatory (WENO) methodology in the FR framework including the nodal type
DG method. The BVD reconstruction adaptively chooses a proper approximation for
the solution function so as to minimize the jump between values at the left-
and right-side of cell boundaries without any ad hoc constant such as the TVB
parameter. Several numerical tests are conducted for a linear advection
equation as well as the selection of an appropriate reconstruction, where the
results of the BVD algorithm are comparable to those using the conventional TVB
limiter. Note that the present work is limited to third or lower order
polynomials, leaving the implementations for higher-order schemes a future
work.


title:
Polarization of the Sunyaev-Zel'dovich effect: relativistic imprint of
  thermal and non-thermal plasma

abstract:
  [Abridged] Inverse Compton scattering of CMB fluctuations off cosmic electron
plasma generates a polarization of the associated Sunyaev-Zel'dovich (SZ)
effect. This signal has been studied so far mostly in the non-relativistic
regime and for a thermal electron population and, as such, has limited
astrophysical applications. Partial attempts to extend this calculation for a
thermal electron plasma in the relativistic regime have been done but cannot be
applied to a general relativistic electron distribution. Here we derive a
general form of the SZ effect polarization valid in the full relativistic
approach for both thermal and non-thermal electron plasmas, as well as for a
generic combination of various electron population co-spatially distributed in
the environments of galaxy clusters or radiogalaxy lobes. We derive the
spectral shape of the Stokes parameters induced by the IC scattering of every
CMB multipole, focusing on the CMB quadrupole and octupole that provide the
largest detectable signals in galaxy clusters. We found that the CMB quadrupole
induced Stoke parameter Q is always positive with a maximum amplitude at 216
GHz which increases slightly with increasing cluster temperature. The CMB
octupole induced Q spectrum shows, instead, a cross-over frequency which
depends on the cluster electron temperature, or on the minimum momentum p_1 as
well as on the power-law spectral index of a non-thermal electron population.
We discuss some possibilities to disentangle the quadrupole-induced Q spectrum
from the octupole-induced one which allow to measure these quantities through
the SZ effect polarization. We finally apply our model to the realistic case of
the Bullet cluster and derive the visibility windows of the total,
quandrupole-induced and octupole-induced Stoke parameter Q in the frequency
ranges accessible to SKA, ALMA, MILLIMETRON and CORE++ experiments.


title: Ultra-forward particle production from CGC+Lund fragmentation

abstract:
  We present an analysis of data on single inclusive pion production measured
by the LHCf collaboration in high-energy proton-proton and proton-nucleus at
ultra-forward rapidities, $8.8 \leq\! y\leq \!10.8$. We also analyse forward
RHIC data for calibration purposes. Our analysis relies on the use of a Monte
Carlo event generator that combines a perturbative description of the
elementary scattering process at partonic level based on the hybrid formalism
of the Color Glass Condensate with an implementation of hadronization in the
framework of the Lund string fragmentation model. This procedure allows us to
reach values of the momenta of the produced particles as low as detected
experimentally $p_t\sim0.1$ GeV. We achieve a good description of single
inclusive spectra of charged particles and neutral pions at RHIC and the LHC
respectively, and nuclear modification factors for proton-lead collisions at
the LHC. Our results add evidence to the idea that particle production in the
domain of very small Bjorken-$x$ is dominated by the saturation effects encoded
in the unintegrated gluon distribution of the target. Being forward particle
production of key importance in the development of air showers, we stress that
this approach allows for a theoretically controlled extrapolation of our
results to the scale of ultra-high energy cosmic rays, thus serving as starting
point for future works on this topic.


title: Gauge Invariance and the Quantum Metric Tensor

abstract:
  The quantum metric tensor was introduced for defining the distance in the
parameter space of a system. However, it is also useful for other purposes,
like predicting quantum phase transitions. Due to the physical information this
tensor provides, its gauge independence sounds reasonable. More over, its
original construction was made by looking for this gauge independence. The aim
of this paper, however, is to prove that the quantum metric tensor does depend
on the gauge. In addition, a real gauge invariant quantum metric tensor is
introduced. In this paper, the gauge dependence is explicitly shown by
computing the quantum metric tensor of the Landau problem in different gauges.
Then, a real gauge independent metric tensor is proposed and computed for the
same Landau problem. Since the gauge dependence has not been observed before,
the results of this paper might lead to a new study of topics that were
believed to be completely understood.

categories: quant-ph cond-mat.stat-mech math-ph math.MP


title:
Distributed Gauss-Newton Method for AC State Estimation: A Belief
  Propagation Approach

abstract:
  In this paper, we propose a solution to an AC state estimation problem in
electric power systems using a fully distributed Gauss-Newton method. The
proposed method is placed within the context of factor graphs and belief
propagation algorithms and closed-form expressions for belief propagation
messages exchanged along the factor graph are derived. The obtained algorithm
provides the same solution as the conventional weighted least-squares state
estimation. Using a simple example, we provide a step-by-step presentation of
the proposed algorithm. Finally, we discuss the convergence behaviour using the
IEEE 14 bus test case.


title: Compactifications of 5d SCFTs with a twist

abstract:
  We study the compactification of 5d SCFTs to 4d on a circle with a twist in a
discrete global symmetry element of these SCFTs. We present evidence that this
leads to various 4d N=2 isolated SCFTs. These include many known theories as
well as seemingly new ones. The known theories include the recently discovered
rank 1 SU(4) SCFT and its mass deformations. One application of the new SCFTs
is in the dual descriptions of the 4d gauge theory SU(N)+1S+(N-2)F. Also
interesting is the appearance of a theory with rank 1 and $F_4$ global
symmetry.


title: Primordial inhomogeneities from massive defects during inflation

abstract:
  We consider the imprints of local massive defects, such as a black hole or a
massive monopole, during inflation. The massive defect breaks the background
homogeneity. We consider the limit that the physical Schwarzschild radius of
the defect is much smaller than the inflationary Hubble radius so a
perturbative analysis is allowed. The inhomogeneities induced in scalar and
gravitational wave power spectrum are calculated. We obtain the amplitudes of
dipole, quadrupole and octupole anisotropies in curvature perturbation power
spectrum and identify the relative configuration of the defect to CMB sphere in
which large observable dipole asymmetry can be generated. We observe a curious
reflection symmetry in which the configuration where the defect is inside the
CMB comoving sphere has the same inhomogeneous variance as its mirror
configuration where the defect is outside the CMB sphere.


title: Random walks on hyperplane arrangements and stopping times

abstract:
  Consider a real hyperplane arrangement and let $\mathcal{C}$ denote the
occurring chambers. Bidigare, Hanlon and Rockmore introduced a Markov chain on
$\mathcal{C}$ which is a generalization of some card shuffling models used in
computer science, biology and card games. This paper introduces strong
stationary arguments for this Markov chain, which provide explicit bounds for
the separation distance.


title: Optimal Pricing under Mixed Logit Choice

abstract:
  In this paper we consider the problem of pricing multiple differentiated
products. This is challenging as a price change in one product, not only
changes the demand of that particular product, but also the demand for the
other products. To address this problem, customer choice models have recently
been introduced as these are capable of describing customer choice behavior
across differentiated products. In the present paper the objective is to obtain
the revenue-maximizing prices when the customer's decision making process is
modelled according to a particular customer choice model, namely the mixed
logit model. The main advantage of using the mixed logit model, also known as
the random coefficients logit model, for this purpose is its flexibility. In
the single-product case we establish log-concavity of the optimization problem
under certain regularity conditions. In addition, in the multi-product case, we
present the results of our extensive numerical experiments. These suggest that
the mixed logit model, by taking unobserved customer heterogeneity and flexible
substitution patterns into account, can significantly improve the attainable
revenue.


title:
Observational selection biases in time-delay strong lensing and their
  impact on cosmography

abstract:
  Inferring cosmological parameters from time-delay strong lenses requires a
significant investment of telescope time; it is therefore tempting to focus on
the systems with the brightest sources, the highest image multiplicities and
the widest image separations. We investigate if this selection bias can
influence the properties of the lenses studied and the cosmological parameters
that are inferred. Using a population of lenses with ellipsoidal powerlaw
density profiles, we build a sample of double and quadruple image systems.
Assuming reasonable thresholds on image separation and flux, based on current
lens monitoring campaigns, we find that the typical density profile slopes of
monitorable lenses are significantly shallower than the input ensemble. From a
sample of quadruple image lenses we find that this selection function can
introduce a 3.5% bias on the inferred time-delay distances if the ensemble of
deflector properties is used as a prior for a cosmographical analysis. This
bias remains at the 2.4% level when high resolution imaging of the quasar host
is used to precisely infer the density profiles of individual lenses. We also
investigate if the lines-of-sight for monitorable strong lenses are biased.
After adding external convergence, $\kappa$, and shear to our lens population
we find that the expectation value for $\kappa$ is increased by 0.004 and 0.009
for doubles and quads respectively. $\kappa$ is degenerate with the value of
$H_0$ inferred from time delays; fortunately the shift in $\kappa$ only induces
a 0.9 (0.4) percent bias on $H_0$ for quads (doubles). We therefore conclude
that whilst the properties of typical quasar lenses and their lines-of-sight do
deviate from the global population, the total magnitude of this effect is
likely a subdominant effect for current analyses, but has the potential to be a
major systematic for samples of $\sim$25 or more lenses.


title: Unveiling the formation route of the largest galaxies in the universe

abstract:
  Observational evidence indicates that the role of gas is secondary to that of
gravity in the formation of the most luminous spheroids inhabiting the centres
of galaxy associations, as originally conjectured in the late 80's/early 90's.
However, attempts to explain the origin of the Fundamental Plane (FP) of
massive early-type galaxies (ETGs) -- a tilted version of the scaling relation
connecting the size, velocity dispersion and mass of virialized homologous
systems -- based on sequences of pairwise mergers, have systematically
concluded that dissipation cannot be ignored. We use controlled simulations of
the previrialization stage of galaxy groups to show that multiple collisionless
merging is capable of creating realistic first-ranked galaxies. Our mock
remnants define a thin FP that perfectly fits data from all kinds of giant ETGs
in the local volume, showing the existence of a unified relationship for these
systems. High-ranked galaxies occupy in the FP different areas than standard
objects, a segregation which is viewed essentially as zero-point offsets in the
2D correlations arising from standard projections of this plane. Our findings
make a strong case for considering hierarchical dissipationless merging a
viable route for the formation of the largest galaxies in the universe.


title: Fundamental Groups of Simplicial Complexes

abstract:
  We define two different simplicial complexes, the common divisor simplicial
complex and the prime divisor simplicial complex, from a set of integers, and
explore their similarities. We will define a map between the two simplicial
complexes, and use this map to show that for any set of integers, the
fundamental groups of the resulting simplicial complexes are isomorphic.


title:
Cohomological Hasse principle for schemes over valuation rings of higher
  dimensional local fields

abstract:
  K. Kato's conjecture about the cohomological Hasse principle for regular
connected schemes $\mathfrak X$ which are flat and proper over the complete
discrete valuation rings $\mathcal O_N$ of higher local fields $F_N$ is proven.
This generalizes the work of M. Kerz, S. Saito and U. Jannsen for finite fields
to the case of all higher local fields. For that purpose a $p$-alteration
theorem for the local uniformization of schemes over valuation rings of
arbitrary finite rank and a corresponding Bertini theorem is developed
extending the results of O. Gabber, J. deJong, L. Illusie, M. Temkin, S. Saito,
U. Jannsen to the non-noetherian world. As an application it is shown that
certain motivic cohomology groups of varieties over higher local fields are
finite. This is one of the rare cases where such a result could be shown for
schemes without finite or separably closed residue fields. Furthermore, it will
be derived that the kernels of the reciprocity map $\rho^X : \text{SK}_N(X) \to
\pi_1^\text{ab}(X)$ and norm map $N_{X|F}: \text{SK}_N(X) \to K_N^M(F_N)$
modulo maximal $p'$-divisible subgroups are finite for regular $X$ which are
proper over a higher local field $F_N$ with final residue characteristic $p$.
This generalizes results of S. Bloch, K. Kato, U. Jannsen, S. Saito from
varieties over finite and local fields to varieties over higher local fields,
both of arbitrary dimensions.


title:
Modeling non-stationary, non-axisymmetric heat patterns in DIII-D
  tokamak

abstract:
  Non-axisymmetric stationary magnetic perturbations lead to the formation of
homoclinic tangles near the divertor magnetic saddle in tokamak discharges.
These tangles intersect the divertor plates in static helical structures that
delimit the regions reached by open magnetic field lines reaching the plasma
column and leading the charged particles to the strike surfaces by parallel
transport. In this article we introduce a non-axisymmetric rotating magnetic
perturbation to model the time development of the three-dimensional magnetic
field of a single-null DIII-D tokamak discharge developing a rotating tearing
mode. The stable and unstable manifolds of the asymmetric magnetic saddle are
calculated through an adaptive method providing the manifold cuts at a given
poloidal plane and the strike surfaces. For the modeled shot, the experimental
heat pattern and its time development are well described by the rotating
unstable manifold, indicating the emergence of homoclinic lobes in a rotating
frame due to the plasma instabilities. In the model it is assumed that the
magnetic field is created by a stationary axisymmetric plasma current and a set
of rotating internal helical filamentary currents. The currents in the
filaments are adjusted to match the waveforms of the magnetic probes at the
mid-plane and the rotating magnetic field is introduced as a perturbation to
the axisymmetric field obtained from a Grad-Shafranov equilibrium
reconstruction code.


title:
Distributed Sequence Memory of Multidimensional Inputs in Recurrent
  Networks

abstract:
  Recurrent neural networks (RNNs) have drawn interest from machine learning
researchers because of their effectiveness at preserving past inputs for
time-varying data processing tasks. To understand the success and limitations
of RNNs, it is critical that we advance our analysis of their fundamental
memory properties. We focus on echo state networks (ESNs), which are RNNs with
simple memoryless nodes and random connectivity. In most existing analyses, the
short-term memory (STM) capacity results conclude that the ESN network size
must scale linearly with the input size for unstructured inputs. The main
contribution of this paper is to provide general results characterizing the STM
capacity for linear ESNs with multidimensional input streams when the inputs
have common low-dimensional structure: sparsity in a basis or significant
statistical dependence between inputs. In both cases, we show that the number
of nodes in the network must scale linearly with the information rate and
poly-logarithmically with the ambient input dimension. The analysis relies on
advanced applications of random matrix theory and results in explicit
non-asymptotic bounds on the recovery error. Taken together, this analysis
provides a significant step forward in our understanding of the STM properties
in RNNs.


title: Enabling science with Gaia observations of naked-eye stars

abstract:
  ESA's Gaia space astrometry mission is performing an all-sky survey of
stellar objects. At the beginning of the nominal mission in July 2014, an
operation scheme was adopted that enabled Gaia to routinely acquire
observations of all stars brighter than the original limit of G~6, i.e. the
naked-eye stars. Here, we describe the current status and extent of those
observations and their on-ground processing. We present an overview of the data
products generated for G<6 stars and the potential scientific applications.
Finally, we discuss how the Gaia survey could be enhanced by further exploiting
the techniques we developed.


title:
Existence of Ground State Eigenvalues for the Spin-Boson Model with
  Critical Infrared Divergence and Multiscale Analysis

abstract:
  A two-level atom coupled to the radiation field is studied. First principles
in physics suggest that the coupling function, representing the interaction
between the atom and the radiation field, behaves like $\vert k \vert^{- 1/2}$,
as the photon momentum k tends to zero. Previous results on non-existence of
ground state eigenvalues suggest that in the most general case binding does not
occur in the spin-boson model, i.e., the minimal energy of the atom-photon
system is not an eigenvalue of the energy operator. Hasler and Herbst have
shown [12], however, that under the additional hypothesis that the coupling
function be off-diagonal -which is customary to assume-binding does indeed
occur. In this paper an alternative proof of binding in case of off-diagonal
coupling is given, i.e., it is proven that, if the coupling function is
off-diagonal, the ground state energy of the spin-boson model is an eigenvalue
of the Hamiltonian. We develop a multiscale method that can be applied in the
situation we study, identifying a new key symmetry operator which we use to
demonstrate that the most singular terms appearing in the multiscale analysis
vanish.


title:
Enhancement of fusion at near and sub-barrier energies for neutron-rich
  light nuclei

abstract:
  Measurement of the fusion cross-section for neutron-rich light nuclei is
crucial in ascertaining if fusion of these nuclei occurs in the outer crust of
a neutron star. We have therefore measured the fusion excitation function at
near-barrier energies for the 19O + 12C system and compared the experimental
results with the fusion excitation function of 18O + 12C and 16O + 12C. In the
experiment a beam of 19O, produced via the 18O(d,p) reaction, was incident on a
12C target at energies near the Coulomb barrier. Evaporation residues produced
in fusion of 18,19O ions with 12C target nuclei were detected with good
geometric efficiency and identified by measuring their energy and
time-of-flight. A significant enhancement in the fusion probability of 19O ions
with a 12C target as compared to 18O ions is observed. The significantly larger
cross-sections observed at near barrier energies are not predicted by a static
model of fusion for 19O + 12C indicating that dynamics play an important role
in the fusion of neutron-rich light nuclei.


title:
Benign-Malignant Lung Nodule Classification with Geometric and
  Appearance Histogram Features

abstract:
  Lung cancer accounts for the highest number of cancer deaths globally. Early
diagnosis of lung nodules is very important to reduce the mortality rate of
patients by improving the diagnosis and treatment of lung cancer. This work
proposes an automated system to classify lung nodules as malignant and benign
in CT images. It presents extensive experimental results using a combination of
geometric and histogram lung nodule image features and different linear and
non-linear discriminant classifiers. The proposed approach is experimentally
validated on the LIDC-IDRI public lung cancer screening thoracic computed
tomography (CT) dataset containing nodule level diagnostic data. The obtained
results are very encouraging correctly classifying 82% of malignant and 93% of
benign nodules on unseen test data at best.


title:
'Spectro-temporal' variabilities and possible physical mechanism for Jet
  ejections

abstract:
  In this paper, we attempt to find out the `spectro-temporal' characteristics
during the jet ejection, of several outbursting Galactic black hole sources
based on RXTE-PCA/HEXTE data in the energy band of 2 - 100 keV. We present
results of detailed analysis of these sources during the rising phase of their
outburst, whenever simultaneous or near-simultaneous X-ray and Radio
observations are `available'. We find that before the peak radio flare
(transient jet) a few of the sources (in addition to those reported earlier)
exhibit `local' softening within the soft intermediate state itself. Except the
duration, all the properties of the `local' softening (QPO not observed,
reduction in total rms, soft spectra) are observed to be similar to the
canonical soft state. We find similar `local' softening for the recent outburst
of V404 Cyg also based on SWIFT observations. Fast changes in the
`spectro-temporal' properties during the `local' softening implies that it may
not be occurring due to change in Keplerian accretion rate. We discuss these
results in the framework of the magnetized two component advective flow model.


title: Automated Parton-Shower Variations in Pythia 8

abstract:
  In the era of precision physics measurements at the LHC, efficient and
exhaustive estimations of theoretical uncertainties play an increasingly
crucial role. In the context of Monte Carlo (MC) event generators, the
estimation of such uncertainties traditionally requires independent MC runs for
each variation, for a linear increase in total run time. In this work, we
report on an automated evaluation of the dominant (renormalization-scale and
non-singular) perturbative uncertainties in the PYTHIA 8 event generator, with
only a modest computational overhead. Each generated event is accompanied by a
vector of alternative weights (one for each uncertainty variation), with each
set separately preserving the total cross section. Explicit scale-compensating
terms can be included, reflecting known coefficients of higher-order splitting
terms and reducing the effect of the variations. The formalism also allows for
the enhancement of rare partonic splittings, such as $g \to b \bar{b}$ and
$q\to q \gamma$, to obtain weighted samples enriched in these splittings while
preserving the correct physical Sudakov factors.


title: User Performance in Small Cells Networks with Inter-Cell Mobility

abstract:
  We analyze the impact of intra-cell mobility on user performance in dense
networks such as that enabled by LTE-A and 5G. To this end, we consider a
homogeneous network of small cells and first show how to reduce the evaluation
of user performance to the case of a single representative cell. We then
propose simple analytical models that capture mobility through the distribution
of the residual sojourn time of mobile users in the cell. An approximate model,
based on Quasi-Stationary (QS) assumptions, is developed in order to speed up
computation in the Markovian framework. We use these models to derive the
average throughput of both mobile and static users, along with the probability
of handover for mobile users. Numerical evaluation and simulation results are
provided to assess the accuracy of the proposed models. We show, in particular,
that both classes of users benefit from a throughput gain induced by the
"opportunistic" displacement of mobile users among cells.


title:
Can an interdisciplinary field contribute to one of the parent
  disciplines from which it emerged?

abstract:
  In the light of contemporary discussions of inter and transdisciplinarity,
this paper approaches econophysics and sociophysics to seek a response to the
question -- whether these interdisciplinary fields could contribute to physics
and economics. Drawing upon the literature on history and philosophy of
science, the paper argues that the two way traffic between physics and
economics has a long history and this is likely to continue in the future.


title: On the 4D generalized Proca action for an Abelian vector field

abstract:
  We summarize previous results on the most general Proca theory in 4
dimensions containing only first-order derivatives in the vector field
(second-order at most in the associated St\"uckelberg scalar) and having only
three propagating degrees of freedom with dynamics controlled by second-order
equations of motion. Discussing the Hessian condition used in previous works,
we conjecture that, as in the scalar galileon case, the most complete action
contains only a finite number of terms with second-order derivatives of the
St\"uckelberg field describing the longitudinal mode, which is in agreement
with the results of JCAP 1405, 015 (2014) and Phys. Lett. B 757, 405 (2016) and
complements those of JCAP 1602, 004 (2016). We also correct and complete the
parity violating sector, obtaining an extra term on top of the arbitrary
function of the field $A_\mu$, the Faraday tensor $F_{\mu \nu}$ and its Hodge
dual $\tilde{F}_{\mu \nu}$.


title:
Two-gap superconductivity in LaNiGa$_2$ with non-unitary triplet pairing
  and even parity gap symmetry

abstract:
  The nature of the pairing states of superconducting LaNiC$_2$ and LaNiGa$_2$
has to date remained a puzzling question. Broken time reversal symmetry has
been observed in both compounds and a group theoretical analysis implies a
non-unitary triplet pairing state. However all the allowed non-unitary triplet
states have nodal gap functions but most thermodynamic and NMR measurements
indicate fully gapped superconductivity in LaNiC$_2$. Here we probe the gap
symmetry of LaNiGa$_2$ by measuring the London penetration depth, specific heat
and upper critical field. These measurements demonstrate two-gap nodeless
superconductivity in LaNiGa$_2$, suggesting that this is a common feature of
both compounds. These results allow us to propose a novel triplet
superconducting state, where the pairing occurs between electrons of the same
spin, but on different orbitals. In this case the superconducting wavefunction
has a triplet spin component but isotropic even parity gap symmetry, yet the
overall wavefunction remains antisymmetric under particle exchange. This model
leads to a nodeless two-gap superconducting state which breaks time reversal
symmetry, and therefore accounts well for the seemingly contradictory
experimental results.


title:
MobileAppScrutinator: A Simple yet Efficient Dynamic Analysis Approach
  for Detecting Privacy Leaks across Mobile OSs

abstract:
  Smartphones, the devices we carry everywhere with us, are being heavily
tracked and have undoubtedly become a major threat to our privacy. As "tracking
the trackers" has become a necessity, various static and dynamic analysis tools
have been developed in the past. However, today, we still lack suitable tools
to detect, measure and compare the ongoing tracking across mobile OSs. To this
end, we propose MobileAppScrutinator, based on a simple yet efficient dynamic
analysis approach, that works on both Android and iOS (the two most popular OSs
today). To demonstrate the current trend in tracking, we select 140 most
representative Apps available on both Android and iOS AppStores and test them
with MobileAppScrutinator. In fact, choosing the same set of apps on both
Android and iOS also enables us to compare the ongoing tracking on these two
OSs. Finally, we also discuss the effectiveness of privacy safeguards available
on Android and iOS. We show that neither Android nor iOS privacy safeguards in
their present state are completely satisfying.


title: On $M$ -- terms approximations Besov classes in Lorentz spaces

abstract:
  In this paper we consider Lorentz space with a mixed norm of periodic
functions of many variables. We obtain the exact estimation of the best M-term
approximations of Nikol'ski's, Besov's classes in the Lorentz space with the
mixed norm.


title:
Pairwise Decomposition of Image Sequences for Active Multi-View
  Recognition

abstract:
  A multi-view image sequence provides a much richer capacity for object
recognition than from a single image. However, most existing solutions to
multi-view recognition typically adopt hand-crafted, model-based geometric
methods, which do not readily embrace recent trends in deep learning. We
propose to bring Convolutional Neural Networks to generic multi-view
recognition, by decomposing an image sequence into a set of image pairs,
classifying each pair independently, and then learning an object classifier by
weighting the contribution of each pair. This allows for recognition over
arbitrary camera trajectories, without requiring explicit training over the
potentially infinite number of camera paths and lengths. Building these
pairwise relationships then naturally extends to the next-best-view problem in
an active recognition framework. To achieve this, we train a second
Convolutional Neural Network to map directly from an observed image to next
viewpoint. Finally, we incorporate this into a trajectory optimisation task,
whereby the best recognition confidence is sought for a given trajectory
length. We present state-of-the-art results in both guided and unguided
multi-view recognition on the ModelNet dataset, and show how our method can be
used with depth images, greyscale images, or both.


title:
Probing interstellar turbulence in cirrus with deep optical imaging: no
  sign of energy dissipation at 0.01 pc scale

abstract:
  Diffuse Galactic light has been observed in the optical since the 1930s. We
propose that, when observed in the optical with deep imaging surveys, it can be
used as a tracer of the turbulent cascade in the diffuse interstellar medium
(ISM), down to scales of about 1 arcsec. Here we present a power spectrum
analysis of the dust column density of a diffuse cirrus at high Galactic
latitude (l ~ 198 deg, b ~ 32 deg) as derived from the combination of a MegaCam
g-band image, obtained as part of the MATLAS large programme at the CFHT, with
Planck radiance and Wise 12 micron data. The combination of these three
datasets have allowed us to compute the density power spectrum of the HI over
scales of more than three orders of magnitude. We found that the density field
is well described by a single power law over scales ranging from 0.01 to 50 pc.
The exponent of the power spectrum, gamma=-2.9 +- 0.1, is compatible with what
is expected for thermally bi-stable and turbulent HI. We did not find any
steepening of the power spectrum at small scales indicating that the typical
scale at which turbulent energy is dissipated in this medium is smaller than
0.01pc. The ambipolar diffusion scenario that is usually proposed as the main
dissipative agent, is consistent with our data only if the density of the cloud
observed is higher than the typical values assumed for the cold neutral medium
gas. We discuss the new avenue offered by deep optical imaging surveys for the
study of the low density ISM structure and turbulence.


title:
No bad local minima: Data independent training error guarantees for
  multilayer neural networks

abstract:
  We use smoothed analysis techniques to provide guarantees on the training
loss of Multilayer Neural Networks (MNNs) at differentiable local minima.
Specifically, we examine MNNs with piecewise linear activation functions,
quadratic loss and a single output, under mild over-parametrization. We prove
that for a MNN with one hidden layer, the training error is zero at every
differentiable local minimum, for almost every dataset and dropout-like noise
realization. We then extend these results to the case of more than one hidden
layer. Our theoretical guarantees assume essentially nothing on the training
data, and are verified numerically. These results suggest why the highly
non-convex loss of such MNNs can be easily optimized using local updates (e.g.,
stochastic gradient descent), as observed empirically.


title: Naturally light neutrinos in $Diracon$ model

abstract:
  We propose a simple model for Dirac neutrinos where the smallness of neutrino
mass follows from a parameter $\kappa$ whose absence enhances the symmetry of
the theory. The symmetry breaking is performed by a two-doublet Higgs sector
supplemented by an extra gauge singlet scalar, realizing an accidental global
$U(1)$ symmetry. Its spontaneous breaking at the few TeV scale leads to a
physical Nambu-Goldstone boson - the $Diracon$, denoted $\mathcal{D}$ - which
is restricted by astrophysics and induces invisible Higgs decays $h\to
\mathcal{D} \mathcal {D}$. The scheme provides a rich, yet very simple
reference scenario for symmetry breaking studies at colliders such as the LHC.


title: Asymmetric Quantum Dialogue in Noisy Environment

abstract:
  A notion of asymmetric quantum dialogue (AQD) is introduced. Conventional
protocols of quantum dialogue are essentially symmetric as both the users
(Alice and Bob) can encode the same amount of classical information. In
contrast, the scheme for AQD introduced here provides different amount of
communication powers to Alice and Bob. The proposed scheme, offers an
architecture, where the entangled state and the encoding scheme to be shared
between Alice and Bob depends on the amount of classical information they want
to exchange with each other. The general structure for the AQD scheme has been
obtained using a group theoretic structure of the operators introduced in
(Shukla et al., Phys. Lett. A, 377 (2013) 518). The effect of different types
of noises (e.g., amplitude damping and phase damping noise) on the proposed
scheme is investigated, and it is shown that the proposed AQD is robust and
uses optimized amount of quantum resources.


title: Duration problem: basic concept and some extensions

abstract:
  We consider a sequence of independent random variables with the known
distribution observed sequentially. The observation $n$ is assumed to be a
value of one order statistics such as s:n-th, where 1 is less than s is less
than n. It the instances following the $n$th observation it may remain of the
s:m or it will be the value of the order statistics r:m (of m> n observations).
Changing the rank of the observation, along with expanding a set of
observations there is a random phenomenon that is difficult to predict. From
practical reasons it is of great interest. Among others, we pose the question
of the moment in which the observation appears and whose rank will not change
significantly until the end of sampling of a certain size. We also attempt to
answer which observation should be kept to have the "good quality observation"
as long as possible. This last question was analysed by Ferguson, Hardwick and
Tamaki (1991) in the abstract form which they called the problem of duration.
  This article gives a systematical presentation of the known duration models
and a new modifications. We collect results from different papers on the
duration of the extremal observation in the no-information (denoted as rank
based) case and the full-information case. In the case of non-extremal
observation duration models the most appealing are various settings related to
the two extremal order statistics. In the no-information case it will be the
maximizing duration of owning the relatively best or the second best object.
The idea was formulated and the problem was solved by Szajowski and Tamaki
(2006). The full-information duration problem with special requirement was
presented by Kurushima and Ano (2010).