title:
Rotational diffusion under torque: Microscopic reversibility and excess
  entropy

abstract:
  We consider rotational diffusion for two systems - a macrospin under external
magnetic field, and a particle diffusing on the surface of a sphere under
external torque. Microstates in the two cases transform differently under
time-reversal. This results in Clausius like dependence of stochastic entropy
production (EP) for macrospins, and an excess EP for diffusion of particles on
sphere. The total EP in both the cases obey fluctuation theorems. For
macrospins, we derive analytical expression for probability distribution of
total EP in the adiabatic limit. Numerical simulations show that the
distribution functions of EP agree well with theoretical predictions.


title: Transmission Resonances Anomaly in 1D Disordered Quantum Systems

abstract:
  Connections between the electron eigenstates and conductivity of
one-dimensional disordered electron systems is studied in the framework of the
tight-binding model. We show that for weak disorder only part of the states
exhibit resonant transmission and contribute to the conductivity. The rest of
the eigenvalues are not associated with peaks in transmission and the
amplitudes of their wave functions do not exhibit a significant maxima within
the sample. Moreover, unlike ordinary states, the lifetimes of these `hidden'
modes either remain constant or even decrease (depending on the coupling with
the leads) as the disorder becomes stronger. In a wide range of the disorder
strengths, the averaged ratio of the number of transmission peaks to the total
number of the eigenstates is independent of the degree of disorder and is close
to the value $\sqrt{2/5}$, which was derived analytically in the
weak-scattering approximation. These results are in perfect analogy to the
spectral and transport properties of light in one-dimensional randomly
inhomogeneous media, which provides strong grounds to believe that the
existence of hidden, non-conducting modes is a general phenomenon inherent to
1D open random systems, and their fraction of the total density of states is
the same for quantum particles and classical waves.


title:
Higher-Order Recursion Abstraction: How to Make Ackermann, Knuth and
  Conway Look Like a Bunch of Primitives, Figuratively Speaking

abstract:
  The Ackermann function is a famous total recursive binary function on the
natural numbers. It is the archetypal example of such a function that is not
primitive recursive, in the sense of classical recursion theory. However, and
in seeming contradiction, there are generalized notions of total recursion, for
which the Ackermann function is in fact primitive recursive, and often featured
as a witness for the additional power gained by the generalization. Here, we
investigate techniques for finding and analyzing the primitive form of
complicated recursive functions, namely also Knuth's and Conway's arrow
notations, in particular by recursion abstraction, in a framework of functional
program transformation.


title: Smooth Hamilton-Jacobi solutions for the Horocycle flow

abstract:
  In this paper we compute all the smooth solutions to the Hamilton-Jacobi
equation associated with the horocycle flow. This can be seen as the
Euler-Lagrange flow (restricted to the energy level set $E^{-1}(\frac 12)$)
defined by the Tonelli Lagrangian $L:T\mathbb H\rightarrow \mathbb R$ given by
(hyperbolic) kinetic energy plus the standard magnetic potential. The method we
use is to look at Lagrangian graphs that are contained in the level set
$\{H=\frac 12\}$, where $H:T^*\mathbb H\rightarrow \mathbb R$ denotes the
Hamiltonian dual to $L$.


title: A Subsequence Interleaving Model for Sequential Pattern Mining

abstract:
  Recent sequential pattern mining methods have used the minimum description
length (MDL) principle to define an encoding scheme which describes an
algorithm for mining the most compressing patterns in a database. We present a
novel subsequence interleaving model based on a probabilistic model of the
sequence database, which allows us to search for the most compressing set of
patterns without designing a specific encoding scheme. Our proposed algorithm
is able to efficiently mine the most relevant sequential patterns and rank them
using an associated measure of interestingness. The efficient inference in our
model is a direct result of our use of a structural expectation-maximization
framework, in which the expectation-step takes the form of a submodular
optimization problem subject to a coverage constraint. We show on both
synthetic and real world datasets that our model mines a set of sequential
patterns with low spuriousness and redundancy, high interpretability and
usefulness in real-world applications. Furthermore, we demonstrate that the
quality of the patterns from our approach is comparable to, if not better than,
existing state of the art sequential pattern mining algorithms.


title:
Synchrotron heating by a fast radio burst in a self-absorbed synchrotron
  nebula and its observational signature

abstract:
  Fast radio bursts (FRBs) are mysterious transient sources. If extragalactic,
as suggested by their relative large dispersion measures, their brightness
temperatures must be extremely high. Some FRB models (e.g. young pulsar model,
magnetar giant flare model, or supra-massive neutron star collapse model)
suggest that they may be associated with a synchrotron nebula. Here we study a
synchrotron-heating process by an FRB in a self-absorbed synchrotron nebula. If
the FRB frequency is below the synchrotron self-absorption frequency of the
nebula, electrons in the nebula would absorb FRB photons, leading to a harder
electron spectrum and enhanced self-absorbed synchrotron emission. In the
meantime, the FRB flux is absorbed by the nebula electrons. We calculate the
spectra of FRB-heated synchrotron nebulae, and show that the nebula spectra
would show a significant hump in several decades near the self-absorption
frequency. Identifying such a spectral feature would reveal an embedded FRB in
a synchrotron nebula.


title: Pomeron Interactions from the Einstein-Hilbert Action

abstract:
  Holographic models of QCD, collectively known as AdS/QCD, have been proven
useful in deriving several properties of hadrons. One particular feature well
reproduced by such models is the Regge trajectories, both for mesons and
glueballs. We focus on scalar and tensor glueballs, and derive an effective
theory for the Pomeron by analytic continuation along the leading trajectory
from the tensor glueball. It then follows that the Pomeron, as the tensor
glueball itself, should possess a two-index polarization tensor, inherited from
the graviton. The three-graviton interaction is deduced from the
Einstein-Hilbert action. Using this structure in the cross section of
double-Pomeron production of the tensor glueball, we calculate certain angular
distributions of production and compare them with those from the CERN WA102
experiment. We find that the agreement is very good for the $f_2(2300)$ tensor
glueball candidate. At the same time, other tensor states -- such as
$f_2(1270)$ and $f'_2(1520)$ -- have completely different distributions, which
we interpret as consequence of the fact that they are not glueballs and thus,
in our model, unrelated to the gravitational excitations, which are dual to
spin-2 glueballs.


title:
VUV photo-processing of PAH cations: quantitative study on the
  ionization versus fragmentation processes

abstract:
  Interstellar polycyclic aromatic hydrocarbons (PAHs) are strongly affected by
the absorption of vacuum ultraviolet (VUV) photons in the interstellar medium
(ISM), yet the branching ratio between ionization and fragmentation is poorly
studied. This is crucial for the stability and charge state of PAHs in the ISM
in different environments, affecting in turn the chemistry, the energy balance,
and the contribution of PAHs to the extinction and emission curves. We studied
the interaction of PAH cations with VUV photons in the 7-20 eV range from the
synchrotron SOLEIL beamline, DESIRS. We recorded by action spectroscopy the
relative intensities of photo-fragmentation and photo-ionization for a set of
eight PAH cations ranging in size from 14 to 24 carbon atoms, with different
structures. At photon energies below ~13.6 eV fragmentation dominates for the
smaller species, while for larger species ionization is immediately competitive
after the second ionization potential (IP). At higher photon energies, all
species behave similarly, the ionization yield gradually increases, leveling
off between 0.8 and 0.9 at ~18 eV. Among isomers, PAH structure appears to
mainly affect the fragmentation cross section, but not the ionization cross
section. We also measured the second IP for all species and the third IP for
two of them, all are in good agreement with theoretical ones confirming that
PAH cations can be further ionized in the diffuse ISM. Determining actual PAH
dication abundances in the ISM will require detailed modeling. Our measured
photo-ionization yields for several PAH cations provide a necessary ingredient
for such models.


title: Tight Lower Bounds on Graph Embedding Problems

abstract:
  We prove that unless the Exponential Time Hypothesis (ETH) fails, deciding if
there is a homomorphism from graph $G$ to graph $H$ cannot be done in time
$|V(H)|^{o(|V(G)|)}$. We also show an exponential-time reduction from Graph
Homomorphism to Subgraph Isomorphism. This rules out (subject to ETH) a
possibility of $|V(H)|^{o(|V(H)|)}$-time algorithm deciding if graph $G$ is a
subgraph of $H$. For both problems our lower bounds asymptotically match the
running time of brute-force algorithms trying all possible mappings of one
graph into another. Thus, our work closes the gap in the known complexity of
these fundamental problems.
  Moreover, as a consequence of our reductions conditional lower bounds follow
for other related problems such as Locally Injective Homomorphism, Graph
Minors, Topological Graph Minors, Minimum Distortion Embedding and Quadratic
Assignment Problem.


title:
Dibaryons with two strange quarks and total spin zero in a constituent
  quark model

abstract:
  We investigate the symmetry property and construct the wave function of the
dibaryon states containing two strange quarks with S=0 in both the flavor SU(3)
symmetric and breaking cases. We discuss how the color $\otimes$ isospin
$\otimes$ spin states of dibaryon in the symmetry broking case of flavor SU(3)
can be extracted from the fully antisymmetric states in flavor SU(3). The
stability of the dibaryon against the strong decay into two baryons are then
discussed, by using the variational method within a constituent quark model
with a confining and color-spin interactions. To compare our results with that
from lattice QCD in flavor SU(3) limit, we search for the stable H-dibaryon in
a wide range of $\pi$ meson mass. We find that with the given potential, there
is no compact six quark dibaryon state in the SU(3) flavor symmetry broken case
with realistic quark masses as well as in flavor SU(3) symmetric case in a wide
range of quark masses.


title:
Initial boundary value problem for a semilinear parabolic equation with
  absorption and nonlinear nonlocal boundary condition

abstract:
  In this paper we consider an initial boundary value problem for a semilinear
parabolic equation with absorption and nonlinear nonlocal Neumann boundary
condition. We prove comparison principle, the existence theorem of a local
solution and study the problem of uniqueness and nonuniqueness.


title: Theory of plasmonic metasurfaces

abstract:
  In this paper we derive an impedance boundary condition to approximate the
optical scattering effect of an array of plasmonic nanoparticles mounted on a
perfectly conducting plate. We show that at some resonant frequencies the
impedance blows up, allowing for a significant reduction of the scattering from
the plate. Using the spectral properties of a Neumann-Poincare type operator,
we investigate the dependency of the impedance with respect to changes in the
nanoparticle geometry and configuration.


title:
The global uniqueness and $C^1$-regularity of geodesics in expanding
  impulsive gravitational waves

abstract:
  We study geodesics in the complete family of expanding impulsive
gravitational waves propagating in spaces of constant curvature, that is
Minkowski, de Sitter and anti-de Sitter universes. Employing the continuous
form of the metric we rigorously prove existence and global uniqueness of
continuously differentiable geodesics (in the sense of Filippov) and study
their interaction with the impulsive wave. Thereby we justify the
"$C^1$-matching procedure" used in the literature to derive their explicit
form.


title: Technology for the next gravitational wave detectors

abstract:
  This paper reviews some of the key enabling technologies for advanced and
future laser interferometer gravitational wave detectors, which must combine
test masses with the lowest possible optical and acoustic losses, with high
stability lasers and various techniques for suppressing noise. Sect. 1 of this
paper presents a review of the acoustic properties of test masses. Sect. 2
reviews the technology of the amorphous dielectric coatings which are currently
universally used for the mirrors in advanced laser interferometers, but for
which lower acoustic loss would be very advantageous. In sect. 3 a new
generation of crystalline optical coatings that offer a substantial reduction
in thermal noise is reviewed. The optical properties of test masses are
reviewed in sect. 4, with special focus on the properties of silicon, an
important candidate material for future detectors. Sect. 5 of this paper
presents the very low noise, high stability laser technology that underpins all
advanced and next generation laser interferometers.


title: The dissipation tensor $\varepsilon_{ij}$ in wall turbulence

abstract:
  The paper investigates the dissipation tensor $\varepsilon_{ij}$ in wall
turbulence. Available DNS data are examined to illustrate the differences in
the anisotropy of the dissipation tensor $\varepsilon_{ij}$ with respect to the
anisotropy of the Reynolds-stresses $r_{ij}$. The budgets of the transport
equations of the dissipation tensor $\varepsilon_{ij}$ are studied using novel
DNS data of low-Reynolds-number turbulent plane channel flow with spatial
resolution sufficiently fine to accurately determine the correlations of
products of 2-derivatives of fluctuating velocities $u_i'$ and pressure $p'$
which appear in various terms. Finally, the influence of the Reynolds number on
the diagonal components of $\varepsilon_{ij}$ ($\varepsilon_{xx}$,
$\varepsilon_{yy}$, $\varepsilon_{zz}$) and on the various terms in their
transport equations is studied using available DNS data of Vreman and Kuerten
(Phys. Fluids 26 (2014) 085103).


title: An introduction to sampling via measure transport

abstract:
  We present the fundamentals of a measure transport approach to sampling. The
idea is to construct a deterministic coupling---i.e., a transport map---between
a complex "target" probability measure of interest and a simpler reference
measure. Given a transport map, one can generate arbitrarily many independent
and unweighted samples from the target simply by pushing forward reference
samples through the map. We consider two different and complementary scenarios:
first, when only evaluations of the unnormalized target density are available,
and second, when the target distribution is known only through a finite
collection of samples. We show that in both settings the desired transports can
be characterized as the solutions of variational problems. We then address
practical issues associated with the optimization--based construction of
transports: choosing finite-dimensional parameterizations of the map, enforcing
monotonicity, quantifying the error of approximate transports, and refining
approximate transports by enriching the corresponding approximation spaces.
Approximate transports can also be used to "Gaussianize" complex distributions
and thus precondition conventional asymptotically exact sampling schemes. We
place the measure transport approach in broader context, describing connections
with other optimization--based samplers, with inference and density estimation
schemes using optimal transport, and with alternative transformation--based
approaches to simulation. We also sketch current work aimed at the construction
of transport maps in high dimensions, exploiting essential features of the
target distribution (e.g., conditional independence, low-rank structure). The
approaches and algorithms presented here have direct applications to Bayesian
computation and to broader problems of stochastic simulation.


title: Electromagnetic gauge-freedom and work

abstract:
  We argue that the definition of the thermodynamic work done on a charged
particle by a time-dependent electromagnetic field is an open problem, because
the particle's Hamiltonian is not gauge-invariant. The solution of this problem
demands accounting for the source of the field. Hence we focus on the work done
by a heavy body (source) on a lighter particle when the interaction between
them is electromagnetic and relativistic. The work can be defined via the
gauge-invariant kinetic energy of the source. We uncover a formulation of the
first law (or the generalized work-energy theorem) which is derived from
relativistic dynamics, has definite validity conditions, and relates the work
to the particle's Hamiltonian in the Lorenz gauge. Thereby the thermodynamic
work also relates to the mechanic work done by the Lorentz force acting on the
source. The formulation of the first law is based on a specific separation of
the overall energy into those of the source, particle and electromagnetic
field. This separation is deduced from a consistent energy-momentum tensor.
Hence it holds relativistic covariance and causality.


title: All is Psi

abstract:
  It is argued that standard quantum theory without collapse provides a
satisfactory explanation of everything we experience in this and in numerous
parallel worlds. The only fundamental ontology is the universal wave function
evolving in a deterministic way without action at a distance.


title: Features and implications of the plateau inflationary potentials

abstract:
  After the last PLANCK CMB data the plateau inflationary potentials are
favored. I give some examples of such inflationary models emphasizing
particularly on the Starobinsky model and its supergravity embedding. I discuss
the crucial implications, regarding the initial conditions problem, of this new
sort of potentials for the standard picture of the inflationary theory.


title:
Theoretical study on the anisotropic electronic structure of
  antiferromagnetic BaFe$_2$As$_2$ and Co-doped Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$
  seen by angle-resolved photoemission

abstract:
  By means of one-step model calculations the strong in-plane anisotropy seen
in angle-resolved photoemission of the well-known iron pnictide prototype
compounds BaFe$_2$As$_2$ and Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$ in their
low-temperature antiferromagnetic phases is investigated. The
fully-relativistic calculations are based on the Korringa-Kohn-Rostoker-Green
function approach combined with the coherent potential approximation alloy
theory to account for the disorder induced by Co substitution on Fe sites in a
reliable way. The results of the calculations can be compared directly to
experimental spectra of detwinned single crystals. One finds very good
agreement with experiment and can reveal all features of the electronic
structure contributing to the in-plane anisotropy. In particular the local
density approximation can capture most of the correlation effects for the
investigated system without the need for more advanced techniques. In addition,
the evolution of the anisotropy for increasing Co concentration $x$ in
Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$ can be tracked almost continuously. The results
are also used to discuss surface effects and it is possible to identify clear
signatures to conclude about different types of surface termination.


title: Symmetry Breaking Predicates for SAT-based DFA Identification

abstract:
  It was shown before that the NP-hard problem of deterministic finite automata
(DFA) identification can be effectively translated to Boolean satisfiability
(SAT). Modern SAT-solvers can tackle hard DFA identification instances
efficiently. We present a technique to reduce the problem search space by
enforcing an enumeration of DFA states in depth-first search (DFS) or
breadth-first search (BFS) order. We propose symmetry breaking predicates,
which can be added to Boolean formulae representing various DFA identification
problems. We show how to apply this technique to DFA identification from both
noiseless and noisy data. Also we propose a method to identify all automata of
the desired size. The proposed approach outperforms the current
state-of-the-art DFASAT method for DFA identification from noiseless data. A
big advantage of the proposed approach is that it allows to determine exactly
the existence or non-existence of a solution of the noisy DFA identification
problem unlike metaheuristic approaches such as genetic algorithms.


title:
Occupation numbers of spherical orbits in self-consistent
  beyond-mean-field methods

abstract:
  We present a method to compute the number of particles occupying spherical
single-particle (SSP) levels within the energy density functional (EDF)
framework. These SSP levels are defined for each nucleus by performing
self-consistent mean-field calculations. The nuclear many-body states, in which
the occupation numbers are evaluated, are obtained with a symmetry conserving
configuration mixing (SCCM) method based on the Gogny EDF. The method allows a
closer comparison between EDF and shell model with configuration mixing in
large valence spaces (SM-CI) results, and can serve as a guidance to define
physically sound valence spaces for SM-CI calculations. As a first application
of the method, we analyze the onset of deformation in neutron-rich $N=40$
isotones and the role of the SSP levels around this harmonic oscillator magic
number, with particular emphasis in the structure of $^{64}$Cr.


title: Variational principles for the guiding-center Vlasov-Maxwell equations

abstract:
  The Lagrange, Euler, and Euler-Poincar\'{e} variational principles for the
guiding-center Vlasov-Maxwell equations are presented. Each variational
principle presents a different approach to deriving guiding-center polarization
and magnetization effects into the guiding-center Maxwell equations. The
conservation laws of energy, momentum, and angular momentum are also derived by
Noether method, where the guiding-center stress tensor is now shown to be
explicitly symmetric.


title: SU(4) Skyrmions in the $\nu=\pm 1$ Quantum Hall State of Graphene

abstract:
  We explore different skyrmion types in the lowest Landau level of graphene at
a filling factor $\nu=\pm 1$. In addition to the formation of spin and valley
pseudospin skyrmions, we show that another type of spin-valley entangled
skyrmions can be stabilized in graphene due to an approximate SU(4) spin-valley
symmetry that is affected by sublattice symmetry-breaking terms. These
skyrmions have a clear signature in spin-resolved density measurements on the
lattice scale, and we discuss the expected patterns for the different skyrmion
types.


title: Enumerating all the Irreducible Polynomials over Finite Field

abstract:
  In this paper we give a detailed analysis of deterministic and randomized
algorithms that enumerate any number of irreducible polynomials of degree $n$
over a finite field and their roots in the extension field in quasilinear where
$N=n^2$ is the size of the output.} time cost per element.
  Our algorithm is based on an improved algorithm for enumerating all the
Lyndon words of length $n$ in linear delay time and the known reduction of
Lyndon words to irreducible polynomials.


title:
Computationally enhanced projection methods for symmetric Sylvester and
  Lyapunov matrix equations

abstract:
  In the numerical treatment of large-scale Sylvester and Lyapunov equations,
projection methods require solving a reduced problem to check convergence. As
the approximation space expands, this solution takes an increasing portion of
the overall computational effort. When data are symmetric, we show that the
Frobenius norm of the residual matrix can be computed at significantly lower
cost than with available methods, without explicitly solving the reduced
problem. For certain classes of problems, the new residual norm expression
combined with a memory-reducing device make classical Krylov strategies
competitive with respect to more recent projection methods. Numerical
experiments illustrate the effectiveness of the new implementation for standard
and extended Krylov subspace methods.


title: Remarks on trigonometric functions after Eisenstein

abstract:
  We modify the Whittaker-Watson account of the Eisenstein approach to the
trigonometric functions, basing these functions independently on the Eisenstein
function $\varepsilon_2$.


title:
Topological Quantum Computation with Non-Abelian Anyons in Fractional
  Quantum Hall States

abstract:
  We review the general strategy of topologically protected quantum information
processing based on non-Abelian anyons, in which quantum information is encoded
into the fusion channels of pairs of anyons and in fusion paths for multi-anyon
states, realized in two-dimensional fractional quantum Hall systems. The
quantum gates which are needed for the quantum information processing in these
multi-qubit registers are implemented by exchange or braiding of the
non-Abelian anyons that are at fixed positions in two-dimensional coordinate
space. As an example we consider the Pfaffian topological quantum computer
based on the fractional quantum Hall state with filling factor $\nu_H=5/2$. The
elementary qubits are constructed by localizing Ising anyons on fractional
quantum Hall antidots and various quantum gates, such as the Hadamard gate,
phase gates and CNOT, are explicitly realized by braiding. We also discuss the
appropriate experimental signatures which could eventually be used to detect
non-Abelian anyons in Coulomb blockaded quantum Hall islands.


title:
On approximation of functions by algebraic polynomials in H\"older
  spaces

abstract:
  We study approximation of functions by algebraic polynomials in the H\"older
spaces corresponding to the generalized Jacobi translation and the
Ditzian-Totik moduli of smoothness. By using modifications of the classical
moduli of smoothness, we give improvements of the direct and inverse theorems
of approximation and prove the criteria of the precise order of decrease of the
best approximation in these spaces. Moreover, we obtain strong converse
inequalities for some methods of approximation of functions. As an example, we
consider approximation by the Durrmeyer-Bernstein polynomial operators.


title:
Classifying $\tau$-tilting modules over the Auslander algebra of
  $K[x]/(x^n)$

abstract:
  We build a bijection between the set $\sttilt\Lambda$ of isomorphism classes
of basic support $\tau$-tilting modules over the Auslander algebra $\Lambda$ of
$K[x]/(x^n)$ and the symmetric group $\mathfrak{S}_{n+1}$, which is an
anti-isomorphism of partially ordered sets with respect to the generation order
on $\sttilt\Lambda$ and the left order on $\mathfrak{S}_{n+1}$. This restricts
to the bijection between the set $\tilt\Lambda$ of isomorphism classes of basic
tilting $\Lambda$-modules and the symmetric group $\mathfrak{S}_n$ due to
Br\"{u}stle, Hille, Ringel and R\"{o}hrle. Regarding the preprojective algebra
$\Gamma$ of Dynkin type $A_n$ as a factor algebra of $\Lambda$, we show that
the tensor functor $-\otimes_{\Lambda}\Gamma$ induces a bijection between
$\sttilt\Lambda\to\sttilt\Gamma$. This recover Mizuno's bijection
$\mathfrak{S}_{n+1}\to\sttilt\Gamma$ for type $A_n$.


title: Spectrum graph coloring and applications to WiFi channel assignment

abstract:
  We introduce and explore a family of vertex-coloring problems which,
surprisingly enough, have not been considered before despite stemming from the
problem of Wi-Fi channel assignment. Given a spectrum of colors, endowed with a
matrix of interferences between each pair of colors, the Threshold Spectrum
Coloring problem fixes the number of colors available and aims to minimize the
interference threshold, i.e., the maximum of the interferences at the vertices.
Conversely, the Chromatic Spectrum Coloring problem fixes a threshold and aims
to minimize the number of colors for which respecting that threshold is
possible. As main theoretical results, we prove tight upper bounds for the
solutions to each problem. Since both problems turn out to be NP-hard, we
complete the scene with experimental results. We propose a DSATUR-based
heuristic and study its performance to minimize the maximum vertex interference
in Wi-Fi channel assignment, both for randomly generated graphs and for a
real-world scenario. Further, for all these graphs we experimentally check the
goodness of the theoretical bounds.


title:
Statistical theory of relaxation of high energy electrons in quantum
  Hall edge states

abstract:
  We investigate theoretically the energy exchange between electrons of two
co-propagating, out-of-equilibrium edge states with opposite spin polarization
in the integer quantum Hall regime. A quantum dot tunnel-coupled to one of the
edge states locally injects electrons at high energy. Thereby a narrow peak in
the energy distribution is created at high energy above the Fermi level. A
second downstream quantum dot performs an energy resolved measurement of the
electronic distribution function. By varying the distance between the two dots,
we are able to follow every step of the energy exchange and relaxation between
the edge states - even analytically under certain conditions. In the absence of
translational invariance along the edge, e.g. due to the presence of disorder,
energy can be exchanged by non-momentum conserving two-particle collisions. For
weakly broken translational invariance, we show that the relaxation is
described by coupled Fokker-Planck equations. From these we find that
relaxation of the injected electrons can be understood statistically as a
generalized drift-diffusion process in energy space for which we determine the
drift-velocity and the dynamical diffusion parameter. Finally, we provide a
physically appealing picture in terms of individual edge state heating as a
result of the relaxation of the injected electrons.


title: Axiomatizations of Team Logics

abstract:
  In a modular approach, we lift Hilbert-style proof systems for propositional,
modal and first-order logic to generalized systems for their respective
team-based extensions. We obtain sound and complete axiomatizations for the
dependence-free fragment FO(~) of V\"a\"an\"anen's first-order team logic TL,
for propositional team logic PTL, quantified propositional team logic QPTL,
modal team logic MTL, and for the corresponding logics of dependence,
independence, inclusion and exclusion.
  As a crucial step in the completeness proof, we show that the above logics
admit, in a particular sense, a semantics-preserving elimination of modalities
and quantifiers from formulas.


title: Effective Hasse principle for the intersection of two quadrics

abstract:
  We consider a smooth system of two homogeneous quadratic equations over the
rationals in at least 13 variables. In this case, the Hasse principle is known
to hold, thanks to the work of Mordell in 1959. The only local obstruction is
over the reals. In this paper, we give an explicit algorithm to decide whether
a nonzero rational solution exists, and if so, to compute one.


title: On the nature of high reddening of Cygnus OB2 #12 hypergiant

abstract:
  To explain the nature of the high reddening (Av~10 mag) towards one of the
most luminous stars in the Galaxy - Cyg OB2 #12 (B5 Ia-0), also known as MT304,
we carried out spectro-photometric observations of 24 stars located in its
vicinity. We included five new B-stars among the members of Cygnus OB2, and for
five more photometrically selected stars we spectroscopically confirmed their
membership. We constructed the map of interstellar extinction within 2.5 arcmin
radius and found that interstellar extinction increases towards MT304.
According to our results the most reddened OB-stars in the association after
MT304 are J203240.35+411420.1 and J203239.90+411436.2, located about 15 arcsec
away from it. Interstellar extinction towards these stars is about 9 mag. The
increase of reddening towards MT304 suggests that the reddening excess may be
caused by the circumstellar shell ejected by the star during its evolution.
This shell absorbs 1 mag, but its chemical composition and temperature are
unclear. We also report the detection of a second component of MT304, and
discovery of an even fainter third component, based on data of speckle
interferometric observations taken with the Russian 6-m telescope.


title: Physics at the FCC-ee

abstract:
  The physics program accessible in $e^+e^-$ collisions at the Future Circular
Collider (FCC-ee) is summarized. The FCC-ee aims at collecting multi-ab$^{-1}$
integrated luminosities in $e^+e^-$ at $\sqrt{s}$ = 90, 160, 240, and 350 GeV,
yielding 10$^{12}$ Z bosons, 10$^{8}$ W$^+$W$^-$ pairs, 10$^{6}$ Higgs bosons
and $4\cdot 10^{5}$ top-quark pairs per year. Such huge data samples combined
with a $\cal{O}(100 \rm keV)$ c.m. energy uncertainty will allow for Standard
Model measurements with unparalleled precision and searches for new physics in
regions not probed so far. The FCC-ee will be able to (i) indirectly discover
new particles coupling to the Higgs and electroweak bosons up to scales
$\Lambda \approx$ 7 and 100 TeV; (ii) perform competitive SUSY tests at the
loop level in regions beyond the LHC reach; and (iii) achieve the best
potential in direct collider searches for dark matter and sterile neutrinos
with masses below 60 GeV.


title:
Nuclear dynamics investigation of the initial electron transfer in the
  cyclobutane pyrimidine dimer lesion repair process by photolyases

abstract:
  Photolyases are proteins capable of harvesting the sunlight to repair DNA
damages caused by UV light. In this work we focus on the first step in the
repair process of the cyclobutane pyrimidine dimer photoproduct (CPD) lesion,
which is an electron transfer (ET) from a flavine cofactor to CPD, and study
the role of various nuclear degrees of freedom (DOF) in this step. The ET step
has been experimentally studied using transient spectroscopy and the
corresponding data provide excellent basis for testing the quality of quantum
dynamical models. Based on previous theoretical studies of electronic structure
and conformations of the protein active site, we present a procedure to build a
diabatic Hamiltonian for simulating the ET reaction in a molecular complex
mimicking the enzyme's active site. We generate a reduced nuclear dimensional
model that provides a first non-empirical quantum dynamical description of the
structural features influencing the ET rate. By varying the nuclear DOF
parametrization in the model to assess the role of different nuclear motions,
we demonstrate that the low frequency flavin butterfly bending mode slows ET by
reducing Franck-Condon overlaps between donor and acceptor states and also
induces decoherence.


title: Prompt Delay

abstract:
  Delay games are two-player games of infinite duration in which one player may
delay her moves to obtain a lookahead on her opponent's moves. Recently, such
games with quantitative winning conditions in weak MSO with the unbounding
quantifier were studied, but their properties turned out to be unsatisfactory.
In particular, unbounded lookahead is in general necessary. Here, we study
delay games with winning conditions given by Prompt-LTL, Linear Temporal Logic
equipped with a parameterized eventually operator whose scope is bounded. Our
main result shows that solving Prompt-LTL delay games is complete for
triply-exponential time. Furthermore, we give tight triply-exponential bounds
on the necessary lookahead and on the scope of the parameterized eventually
operator. Thus, we identify Prompt-LTL as the first known class of well-behaved
quantitative winning conditions for delay games. Finally, we show that applying
our techniques to delay games with \omega-regular winning conditions answers
open questions in the cases where the winning conditions are given by
non-deterministic, universal, or alternating automata.


title:
Generating multi-atom entangled W states via light-matter interface
  based fusion mechanism

abstract:
  W state is a key resource in quantum communication. Fusion technology has
been proven to be a good candidate for preparing a large-size W state from two
or more small-size W states in linear optical system. It is of great importance
to study how to fuse W states via light-matter interface. Here we show that it
is possible to prepare large-size W-state networks using a fusion mechanism in
cavity QED system. The detuned interaction between three atoms and a vacuum
cavity mode constitute the main fusion mechanism, based on which two or three
small-size atomic W states can be fused into a larger-size W state. If no
excitation is detected from those three atoms, the remaining atoms are still in
the product of two or three new W states, which can be re-fused. The
complicated Fredkin gate used in the previous fusion schemes is avoided here. W
states of size 2 can be fused as well. The feasibility analysis shows that our
fusion processes maybe implementable with the current technology. Our results
demonstrate how the light-matter interaction based fusion mechanism can be
realized, and may become the starting point for the fusion of multipartite
entanglement in cavity QED system.


title: Towards Quantum Communication in Free-Space Seawater

abstract:
  Long-distance quantum channels capable of transferring quantum states
faithfully for unconditionally secure quantum communication have been so far
confirmed feasible in both fiber and free-space air. However, it remains
unclear whether seawater, which covers more than 70% of the earth, can also be
utilized, leaving global quantum communication incomplete. Here we
experimentally demonstrate that polarization quantum states including general
qubits and entangled states can well survive after travelling through seawater.
We performed experiments in a 3.3-meter-long tube filled with seawater samples
collected in a range of 36 kilometers in Yellow sea, which conforms to Jerlov
water type I. For single photons at 405 nm in blue-green window, we obtained
average process fidelity above 98%. For entangled photons at 810 nm, even with
high loss, we observe violation of Bell inequality with 33 standard deviations.
This work confirms feasibility of seawater quantum channel, representing the
first step towards underwater quantum communication.


title: Do Public Events Affect Sex Trafficking Activity?

abstract:
  For several years the pervasive belief that the Super Bowl is the single
biggest day for human trafficking in the United States each year has been
perpetuated in popular press despite a lack of evidentiary support. The
practice of relying on hearsay and popular belief for decision-making may
result in misappropriation of resources in anti-trafficking efforts. We propose
a data-driven approach to analyzing sex trafficking, especially as it is
carried on during--and perhaps in response to--large public events such as the
Super Bowl. We examine 33 public events, chosen for attendance numbers
comparable to the Super Bowl from a diversity of types, and use the volume of
escort advertisements posted online as an accessible and reasonable proxy
measure for the actual levels of activity of sex-workers as well as trafficking
victims. Our analysis puts the impact of local public events on sex
advertisement activity into perspective. We find that many of the events we
considered are not correlated with statistically significant impact on
sex-worker advertising, though some are. Additionally, we demonstrate how our
method can uncover evidence of other events, not included in our initial list,
that are correlated with more significant increases in ad activity. Reliance on
quantitative evidence accessible through data-driven analysis can inform wise
resource allocation, guide good policies, and foster the most meaningful
impact.


title:
Self-similar fast-reaction limits for reaction-diffusion systems on
  unbounded domains

abstract:
  We present a unified approach to characterising fast-reaction limits of
systems of either two reaction-diffusion equations, or one reaction-diffusion
equation and one ordinary differential equation, on unbounded domains,
motivated by models of fast chemical reactions where either one or both
reactant(s) is/are mobile. For appropriate initial data, solutions of four
classes of problems each converge in the fast-reaction limit $k \to \infty$ to
a self-similar limit profile that has one of four forms, depending on how many
components diffuse and whether the spatial domain is a half or whole line. For
fixed $k$, long-time convergence to these same self-similar profiles is also
established, thanks to a scaling argument of Kamin. Our results generalise
earlier work of Hilhorst, van der Hout and Peletier to a much wider class of
problems, and provide a quantitative description of the penetration of one
substance into another in both the fast-reaction and long-time regimes.


title:
Electromagnetic Afterglows Associated with Gamma-Ray Emission Coincident
  with Binary Black Hole Merger Event GW150914

abstract:
  The Fermi Gamma-ray Burst Monitor reported the possible detection of the
gamma-ray counterpart of a binary black hole merger event, GW150914. We show
that the gamma-ray emission is caused by a relativistic outflow with Lorentz
factor larger than 10. Subsequently, debris outflow pushes the ambient gas to
form a shock, which is responsible for the afterglow synchrotron emission. We
find that the 1.4 GHz radio flux peaks at $\sim10^5$ sec after the burst
trigger. If the ambient matter is dense enough with density larger than
$\sim10^{-2}$ cm$^{-3}$, then the peak radio flux is $\sim0.1$ mJy, which is
detectable with radio telescopes such as the Very Large Array. The optical
afterglow peaks earlier than the radio, and if the ambient matter density is
larger than $\sim0.1$ cm$^{-3}$, the optical flux is detectable with large
telescopes such as the Subaru Hyper Suprime-Cam. To reveal the currently
unknown mechanisms of the outflow and its gamma-ray emission associated with
the binary black hole merger event, follow-up electromagnetic observations of
afterglows are important. Detection of the afterglow will localize the sky
position of the gravitational wave and the gamma-ray emissions, and it will
support the physical association between them.


title:
A Necessary Condition for the Spectrum of Nonnegative Symmetric $ 5
  \times 5 $ Matrices

abstract:
  Let $A$ be a nonnegative symmetric $ 5 \times 5 $ matrix with eigenvalues $
\lambda_1 \geq \lambda_2 \geq \lambda_3 \geq \lambda_4 \geq \lambda_5 $. We
show that if $ \sum_{i=1}^{5} \lambda_{i} \geq \frac{1}{2} \lambda_1 $ then $
\lambda_3 \leq \sum_{i=1}^{5} \lambda_{i} $. McDonald and Neumann showed that $
\lambda_1 + \lambda_3 + \lambda_4 \geq 0 $. Let $ \sigma = \left( \lambda_1,
\lambda_2, \lambda_3, \lambda_4, \lambda_5 \right) $ be a list of decreasing
real numbers satisfying:
  1. $ \sum_{i=1}^{5} \lambda_{i} \geq \frac{1}{2} \lambda_1 $,
  2. $ \lambda_3 \leq \sum_{i=1}^{5} \lambda_{i} $,
  3. $ \lambda_1 + \lambda_3 + \lambda_4 \geq 0 $,
  4. the Perron property, that is $ \lambda_1 = \max_{\lambda \in \sigma}
\left| \lambda \right| $.
  We show that $ \sigma $ is the spectrum of a nonnegative symmetric $ 5 \times
5 $ matrix. Thus, we solve the symmetric nonnegative inverse eigenvalue problem
for $ n = 5 $ in a region for which a solution has not been known before.


title: Separating Ore sets for prime ideals of quantum algebras

abstract:
  Brown and Goodearl stated a conjecture that provides an explicit description
of the topology of the spectra of quantum algebras. The conjecture takes on a
more explicit form if there exist separating Ore sets for all incident pairs of
torus invariant prime ideals of the given algebra. We prove that this is the
case for the two largest classes of algebras of finite Gelfand-Kirillov
dimension that fit the setting of the conjecture: the quantized coordinate
rings of all simple algebraic groups and the quantum Schubert cell algebras for
all symmetrizable Kac-Moody algebras.


title: T-motives

abstract:
  Considering a (co)homology theory $\mathbb{T}$ on a base category
$\mathcal{C}$ as a fragment of a first-order logical theory we here construct
an abelian category $\mathcal{A}[\mathbb{T}]$ which is universal with respect
to models of $\mathbb{T}$ in abelian categories. Under mild conditions on the
base category $\mathcal{C}$, e.g. for the category of algebraic schemes, we get
a functor from $\mathcal{C}$ to ${\rm Ch}({\rm Ind}(\mathcal{A}[\mathbb{T}]))$
the category of chain complexes of ind-objects of $\mathcal{A}[\mathbb{T}]$.
This functor lifts Nori's motivic functor for algebraic schemes defined over a
subfield of the complex numbers. Furthermore, we construct a triangulated
functor from $D({\rm Ind}(\mathcal{A}[\mathbb{T}]))$ to Voevodsky's motivic
complexes.


title: N-Type Oxide Thermoelectrics Via Visual Search Strategies

abstract:
  We discuss and present search strategies for finding new thermoelectric
compositions based on first principles electronic structure and transport
calculations. We illustrate them by application to a search for potential
n-type oxide thermoelectric materials. This includes a screen based on
visualization of electronic energy isosurfaces. We report compounds that show
potential as thermoelectric materials along with detailed properties, including
SrTiO3, which is a known thermoelectric, and appropriately doped KNbO3 and
rutile TiO2.


title:
Counterexample to the Generalized Bogomolov-Gieseker Inequality for
  Threefolds

abstract:
  We give a counterexample to the generalized Bogomolov-Gieseker inequality for
threefolds conjectured by Bayer, Macr\`i and Toda using the blow up of a point
over three dimensional projective space.


title: Comments on "the return of information theory"

abstract:
  We criticize the article "Quantifying sustainability: Resilience, efficiency
and the return of information theory" (Ulanowicz et al., Ecological Complexity,
2009) for its presentation of information theory to an audience of ecologists.
We find that the formulation and use of basic IT concepts are unnecessarily
obscure, deliberately incompatible with standard terminology, and in places
just mathematically wrong. We lift some of the confusion by correcting errors,
dissecting ambiguities and using standard terminology wherever possible. We
believe that clear and rigorous presentations are necessary in order to enable
information theoreticians and ecologists to engage in a fruitful dialogue.


title: Phonon Localization in Heat Conduction

abstract:
  Departures in phonon heat conduction from diffusion have been extensively
observed in nanostructures through their thermal conductivity reduction and
largely explained with classical size effects neglecting phonon's wave nature.
Here, we report localization-behavior in phonon heat conduction due to multiple
scattering and interference of phonon waves, observed through measurements of
the thermal conductivities of GaAs/AlAs superlattices with ErAs nanodots
randomly distributed at the interfaces. Near room temperature, the measured
thermal conductivities increased with increasing number of SL periods and
eventually saturated, indicating a transition from ballistic-to-diffusive
transport. At low temperatures, the thermal conductivities of the samples with
ErAs dots first increased and then decreased with an increasing number of
periods, signaling phonon wave localization. This Anderson localization
behavior is also validated via atomistic Green's function simulations. The
observation of phonon localization in heat conduction is surprising due to the
broadband nature of thermal transport. This discovery suggests a new path
forward for engineering phonon thermal transport.


title: Three Value Ranges for Symmetric Self-mappings

abstract:
  Let $\mathbb D$ be the unit disc and $z_0\in\mathbb D.$ We determine the
value range $\{f(z_0)\,|\, f\in \mathcal{R}^\geq\}$, where $\mathcal{R}^\geq$
is the set of holomorphic functions $f:\mathbb D\to\mathbb D$ with $f(0)=0$ and
$f'(0)\geq0$ that have only real coefficients in their power series expansion
around $0$, and the smaller set $\{f(z_0)\,|\, f\in \mathcal{R}^\geq, \text{$f$
is typically real}\}.$ Furthermore, we describe a third value range $\{ f(z_0)
\,|\, f \in \mathcal{I}\}$, where $\mathcal{I}$ consists of all univalent
self-mappings of the upper half-plane $\mathbb{H}$ with hydrodynamical
normalization which are symmetric with respect to the imaginary axis.


title:
Entangled simultaneity versus classical interactivity in communication
  complexity

abstract:
  In 1999 Raz demonstrated a partial function that had an efficient quantum
two-way communication protocol but no efficient classical two-way protocol and
asked, whether there existed a function with an efficient quantum one-way
protocol, but still no efficient classical two-way protocol. In 2010 Klartag
and Regev demonstrated such a function and asked, whether there existed a
function with an efficient quantum simultaneous-messages protocol, but still no
efficient classical two-way protocol.
  In this work we answer the latter question affirmatively and present a
partial function Shape, which can be computed by a protocol sending entangled
simultaneous messages of poly-logarithmic size, and whose classical two-way
complexity is lower bounded by a polynomial.


title:
Collinearity constraints for on-shell massless particle three-point
  functions, and implications for allowed-forbidden $n+1$-point functions

abstract:
  A simple collinearity argument implies that the massless particle three-point
function of helicities $h_1, h_2, h_3$ with corresponding real-valued
four-momenta $k_1, k_2, k_3$ taken as all incoming or all outgoing (i.e., $k_1
+k_2 +k_3=0$), vanishes by helicity conservation unless $h_1+h_2+h_3=0$. When
any one particle with four-momentum $k$ is off mass shell, this constraint no
longer applies; a forbidden amplitude with $h_1+h_2+h_3\neq 0$ on-shell can be
nonzero off-shell, but vanishes proportionally to $k^2$ as $k$ approaches mass
shell. When an on-shell forbidden amplitude is coupled to an allowed $n$-point
amplitude to form an $n+1$ point function, this $k^2$ factor in the forbidden
amplitude cancels the $k^2$ in the propagator, leading to a $n+1$-point
function that has no pole at $k^2=0$. We relate our results for real-valued
four-momenta to the corresponding selection rules that have been derived in the
on-shell literature for complexified four-momenta.


title:
Perfect charge compensation in extremely large magnetoresistance
  materials LaSb and LaBi revealed by the first-principles calculations

abstract:
  By the first-principles electronic structure calculations, we have
systematically studied the electronic structures of recently discovered
extremely large magnetoresistance (XMR) materials LaSb and LaBi. We find that
both LaSb and LaBi are semimetals with the electron and hole carriers in
perfect balance. The calculated carrier densities in the order of $10^{20}$
cm$^{-3}$ are in good agreement with the experimental values, implying long
mean free time of carriers and thus high carrier mobilities. With a
semiclassical two-band model, the perfect charge compensation and high carrier
mobilities naturally explain (i) the XMR observed in LaSb and LaBi; (ii) the
non-saturating quadratic dependence of XMR on external magnetic field; and
(iii) the resistivity plateau in the turn-on temperature behavior at very low
temperatures. The explanation of these features without resorting to the
topological effect indicates that they should be the common characteristics of
all perfectly electron-hole compensated semimetals.


title: The quasi-isomorphism class of the Kakimizu complex

abstract:
  It has been shown that the Kakimizu complex of a knot is quasi-isomorphic to
$\mathbb{Z}^n$ for some $n \geq 0$. We give a lower bound on $n$, matching the
upper bound previously given.


title:
Measuring multivariate redundant information with pointwise common
  change in surprisal

abstract:
  The problem of how to properly quantify redundant information is an open
question that has been the subject of much recent research. Redundant
information refers to information about a target variable S that is common to
two or more predictor variables Xi. It can be thought of as quantifying
overlapping information content or similarities in the representation of S
between the Xi. We present a new measure of redundancy which measures the
common change in surprisal shared between variables at the local or pointwise
level. We provide a game-theoretic operational definition of unique
information, and use this to derive constraints which are used to obtain a
maximum entropy distribution. Redundancy is then calculated from this maximum
entropy distribution by counting only those local co-information terms which
admit an unambiguous interpretation as redundant information. We show how this
redundancy measure can be used within the framework of the Partial Information
Decomposition (PID) to give an intuitive decomposition of the multivariate
mutual information into redundant, unique and synergistic contributions. We
compare our new measure to existing approaches over a range of example systems,
including continuous Gaussian variables. Matlab code for the measure is
provided, including all considered examples.

categories: cs.IT math.IT math.ST q-bio.NC q-bio.QM stat.ME stat.TH


title:
Non-relativistic perpendicular shocks modeling young supernova remnants:
  nonstationary dynamics and particle acceleration at forward and reverse
  shocks

abstract:
  For parameters that are applicable to the conditions at young supernova
remnants, we present results of 2D3V particle-in-cell simulations of a
non-relativistic plasma shock with a large-scale perpendicular magnetic field
inclined at 45-deg angle to the simulation plane to approximate 3D physics. We
developed an improved clean setup that uses the collision of two plasma slabs
with different density and velocity, leading to the development of two
distinctive shocks and a contact discontinuity. The shock formation is mediated
by Weibel-type filamentation instabilities that generate magnetic turbulence.
Cyclic reformation is observed in both shocks with similar period, for which we
note global variations on account of shock rippling and local variations
arising from turbulent current filaments. The shock rippling occurs on spatial
and temporal scales given by gyro-motions of shock-reflected ions. The drift
motion of electrons and ions is not a gradient drift, but commensurates with E
x B drift. We observe a stable suprathermal tail in the ion spectra, but no
electron acceleration because the amplitude of Buneman modes in the shock foot
is insufficient for trapping relativistic electrons. We see no evidence of
turbulent reconnection. A comparison with other 2D simulation results suggests
that the plasma beta and the ion-to-electron mass ratio are not decisive for
efficient electron acceleration, but pre-acceleration efficacy might be reduced
with respect to the 2D results once three-dimensional effects are fully
accounted for. Other microphysical factors may also be at play to limit the
amplitude of Buneman waves or prevent return of electrons to the foot region.


title: Classifying the behavior of noncanonical quintessence

abstract:
  We derive general conditions for the existence of stable scaling solutions
for the evolution of noncanonical quintessence, with a Lagrangian of the form
$\mathcal{L}(X,\phi)=X^{\alpha}-V(\phi)$, for power-law and exponential
potentials when the expansion is dominated by a background barotropic fluid.
Our results suggest that in most cases, noncanonical quintessence with such
potentials does not yield interesting models for the observed dark energy. When
the scaling solution is not an attractor, there is a wide range of model
parameters for which the evolution asymptotically resembles a zero-potential
solution with equation of state parameter $w = 1/(2\alpha -1)$, and oscillatory
solutions are also possible for positive power-law potentials; we derive the
conditions on the model parameters which produce both types of behavior. We
investigate thawing noncanonical models with a nearly-flat potential and derive
approximate expressions for the evolution of $w(a)$. These forms for $w(a)$
differ in a characteristic way from the corresponding expressions for canonical
quintessence.


title: On Characterization of Inverse Data in the Boundary Control Method

abstract:
  We deal with a dynamical system
  \begin{align*} & u_{tt}-\Delta u+qu=0 && {\rm in}\,\,\,\Omega \times (0,T)\\
& u\big|_{t=0}=u_t\big|_{t=0}=0 && {\rm in}\,\,\,\overline \Omega\\ &
\partial_\nu u = f && {\rm in}\,\,\,\partial\Omega \times [0,T]\,,
  \end{align*} where $\Omega \subset {\mathbb R}^n$ is a bounded domain, $q \in
L_\infty(\Omega)$ a real-valued function, $\nu$ the outward normal to $\partial
\Omega$, $u=u^f(x,t)$ a solution. The input/output correspondence is realized
by a response operator $R^T: f \mapsto u^f\big|_{\partial\Omega \times [0,T]}$
and its relevant extension by hyperbolicity $R^{2T}$. Ope\-rator $R^{2T}$ is
determined by $q\big|_{\Omega^T}$, where $\Omega^T:=\{x \in \Omega\,|\,\,{\rm
dist\,}(x,\partial \Omega)<T\}$. The inverse problem is: Given $R^{2T}$ to
recover $q$ in $\Omega^T$. We solve this problem by the boundary control method
and describe the {\it ne\-ces\-sary and sufficient} conditions on $R^{2T}$,
which provide its solvability.


title: Skill Evaluation for Newly Graduated Students Via Online Test

abstract:
  Every year in each university many students are graduated holding a first
university degree. For example Bachelor degree in Computer Science. Most of
those students have a motivation to continue with further studies to get higher
education level degree in universities. However, some other students may have
enthusiasm towards working based on their skills that they got during their
life of studies in university. In both cases, it is required that applicant
must pass a test that comprise the entire subject that they learned before. For
this reasons, this research is proposing a new technique to evaluate graduate
students skills.


title:
A Relativistic Model for the Electromagnetic Structure of Baryons from
  the 3rd Resonance Region

abstract:
  We present some predictions for the $\gamma^\ast N \to N^\ast$ transition
amplitudes, where $N$ is the nucleon, and $N^\ast$ is a nucleon excitation from
the third resonance region. First we estimate the transition amplitudes
associated with the second radial excitation of the nucleon, interpreted as the
$N(1710)$ state, using the covariant spectator quark model. After that, we
combine some results from the covariant spectator quark model with the
framework of the single quark transition model, to make predictions for the
$\gamma^\ast N \to N^\ast$ transition amplitudes, where $N^\ast$ is a member of
the $SU(6)$-multiplet $[70,1^-]$. The results for the $\gamma^\ast N \to
N(1520)$ and $\gamma^\ast N \to N(1535)$ transition amplitudes are used as
input to the calculation of the amplitudes $A_{1/2}$, $A_{3/2}$, associated
with the $\gamma^\ast N \to N(1650)$, $\gamma^\ast N \to N(1700)$, $\gamma^\ast
N \to \Delta(1620)$, and $\gamma^\ast N \to \Delta(1700)$ transitions. Our
estimates are compared with the available data. In order to facilitate the
comparison with future experimental data at high $Q^2$, we derived also simple
parametrizations for the amplitudes, compatible with the expected falloff at
high $Q^2$.


title:
Robust Covariance Matrix Estimation for Radar Space-Time Adaptive
  Processing (STAP)

abstract:
  Estimating the disturbance or clutter covariance is a centrally important
problem in radar space time adaptive processing (STAP). The disturbance
covariance matrix should be inferred from training sample observations in
practice. Large number of homogeneous training samples are generally not
available because of difficulty of guaranteeing target free disturbance
observation, practical limitations imposed by the spatio-temporal
nonstationarity, and system considerations. In this dissertation, we look to
address the aforementioned challenges by exploiting physically inspired
constraints into ML estimation. While adding constraints is beneficial to
achieve satisfactory performance in the practical regime of limited training,
it leads to a challenging problem. We focus on breaking this classical
trade-off between computational tractability and desirable performance
measures, particularly in training starved regimes. In particular, we exploit
both the structure of the disturbance covariance and importantly the knowledge
of the clutter rank to yield a new rank constrained maximum likelihood (RCML)
estimator. In addition, we derive a new covariance estimator for STAP that
jointly considers a Toeplitz structure and a rank constraint on the clutter
component.
  Finally, we address the problem of working with inexact physical radar
parameters under a practical radar environment. We propose a robust covariance
estimation method via an expected likelihood (EL) approach. We analyze
covariance estimation algorithms under three different cases of imperfect
constraints: 1) only rank constraint, 2) both rank and noise power constraint,
and 3) condition number constraint. For each case, we formulate estimation of
the constraint as an optimization problem with the EL criterion and formally
derive and prove a significant analytical result such as uniqueness of the
solution.


title:
Validity criteria for Fermi's golden rule scattering rates applied to
  metallic nanowires

abstract:
  Fermi's golden rule underpins the investigation of mobile carriers
propagating through various solids, being a standard tool to calculate their
scattering rates. As such, it provides a perturbative estimate under the
implicit assumption that the effect of the interaction Hamiltonian which causes
the scattering events is sufficiently small. To check the validity of this
assumption, we present a general framework to derive simple validity criteria
in order to assess whether the scattering rates can be trusted for the system
under consideration, given its statistical properties such as average size,
electron density, impurity density et cetera. We derive concrete validity
criteria for metallic nanowires with conduction electrons populating a single
parabolic band subjected to different elastic scattering mechanisms:
impurities, grain boundaries and surface roughness.


title: Nonlinear electrodynamics is skilled with knots

abstract:
  The aims of this letter are three-fold: First is to show that nonlinear
generalizations of electrodynamics support various types of knotted solutions
in vacuum. The solutions are universal in the sense that they do not depend on
the specific Lagrangian density, at least if the latter gives rise to a
well-posed theory. Second is to describe the interaction between probe waves
and knotted background configurations. We show that the qualitative behaviour
of this interaction may be described in terms of Robinson congruences, which
appear explicitly in the causal structure of the theory. Finally, we argue that
optical arrangements endowed with intense background fields could be the
natural place to look for the knots experimentally.


title:
Optimizing Transmission Lengths for Limited Feedback with Non-Binary
  LDPC Examples

abstract:
  This paper presents a general approach for optimizing the number of symbols
in increments (packets of incremental redundancy) in a feedback communication
system with a limited number of increments. This approach is based on a tight
normal approximation on the rate for successful decoding. Applying this
approach to a variety of feedback systems using non-binary (NB) low-density
parity-check (LDPC) codes shows that greater than 90% of capacity can be
achieved with average blocklengths fewer than 500 transmitted bits. One result
is that the performance with ten increments closely approaches the performance
with an infinite number of increments. The paper focuses on binary- input
additive-white Gaussian noise (BI-AWGN) channels but also demonstrates that the
normal approximation works well on examples of fading channels as well as
high-SNR AWGN channels that require larger QAM constellations. The paper
explores both variable-length feedback codes with termination (VLFT) and the
more practical variable length feedback (VLF) codes without termination that
require no assumption of noiseless transmitter confirmation. For VLF we
consider both a two-phase scheme and CRC-based scheme.


title: Dependence of the heavily covered point on parameters

abstract:
  We examine Gromov's method of selecting a point "heavily covered" by
simplices formed by a given finite point sets, in order to understand the
dependence of the heavily covered point on parameters. We have no continuous
dependence, but manage to utilize the "homological continuous dependence" of
the heavily covered point. This allows us to infer some corollaries in a usual
way. We also give an elementary argument to prove the simplest of these
corollaries.


title:
Generating multi-photon W-like states for perfect quantum teleportation
  and superdense coding

abstract:
  An interesting aspect of multipartite entanglement is that for perfect
teleportation and superdense coding, not the maximally entangled W states but a
special class of non-maximally entangled W-like states are required. Therefore,
efficient preparation of such W-like states is of great importance in quantum
communications, which has not been studied as much as the preparation of W
states. In this letter, we propose a simple optical scheme for efficient
preparation of large-scale polarization based entangled W-like states by fusing
two W-like states or expanding a W-like state with an ancilla photon. Our
scheme can also generate large-scale W states by fusing or expanding W or even
W-like states. The cost analysis show that in generating large scale W states,
the fusion mechanism achieves a higher efficiency with non-maximally entangled
W-like states than maximally entangled W states. Our scheme can also start
fusion or expansion with Bell states, and it is composed of a polarization
dependent beam splitter, two polarizing beam splitters and photon detectors.
Requiring no ancilla photons or controlled gates to operate, our scheme can be
realized with the current photonics technology and we believe it enables
advances in quantum teleportation and superdense coding in multipartite
settings.


title: ATLAS on-Z Excess Through Vector-Like Quarks

abstract:
  We investigate the possibility that the excess observed in the leptonic-$Z
+$jets $+\slashed{E}_T$ ATLAS SUSY search is due to pair productions of a
vector-like quark $U$ decaying to the first-generation quarks and $Z$ boson. We
find that the excess can be explained within the 2$\sigma$ (up to 1.4$\sigma$)
level while evading the constraints from the other LHC searches. The preferred
range of the mass and branching ratio are $610 < m_{U} < 760$ GeV and ${\rm
Br}(U \rightarrow Z q) > 0.3$-$0.45$, respectively.


title:
Spin susceptibility and electron-phonon coupling of two-dimensional
  materials by range-separated hybrid density functionals: Case study of
  Li$_x$ZrNCl

abstract:
  We investigate the capability of density functional theory (DFT) to
appropriately describe the spin susceptibility, $\chi_s$, and the intervalley
electron-phonon coupling in Li$_x$ZrNCl. At low doping, Li$_x$ZrNCl behaves as
a two-dimensional two-valley electron gas, with parabolic bands. In such a
system, $\chi_s$ increases with decreasing doping because of the
electron-electron interaction. We show that DFT with local functionals
(LDA/GGA) is not capable of reproducing this behavior. The use of exact
exchange in Hartree-Fock (HF) or in DFT hybrid functionals enhances $\chi_s$.
HF, B3LYP, and PBE0 approaches overestimate $\chi_s$, whereas the
range-separated HSE06 functional leads to results similar to those obtained in
the random phase approximation (RPA) applied to a two-valley two-spin electron
gas. Within HF, Li$_x$ZrNCl is even unstable towards a ferromagnetic state for
$x<0.16$. The intervalley phonons induce an imbalance in the valley occupation
that can be viewed as the effect of a pseudomagnetic field. Thus, similarly to
what happens for $\chi_s$, the electron-phonon coupling of intervalley phonons
is enhanced by the electron-electron interaction. Only hybrid DFT functionals
capture such an enhancement and the HSE06 functional reproduces the RPA results
presented in M. Calandra {\it et al.} [Phys. Rev. Lett. {\bf 114}, 077001
(2015)]. These results imply that the description of the susceptibility and
electron-phonon coupling with a range-separated hybrid functional would be
important also in other two-dimensional weakly doped semiconductors, such as
transition-metal dichalcogenides and graphene.


title: Stability of Modified Gravity Coupled by the Weyl Tensor

abstract:
  In this paper, we try to consider the stability conditions of a modified
gravity coupled by Weyl tensor. In this way, we indicate the suitable
conditions for a successful bounce while the equation of state (EoS) parameter
crosses the phantom divider for our new corrected modified gravity. In the
spatially flat Friedmann-Lema\^{\i}tre-Robertson-Walker (FLRW) universe,
according to the ordinary version of the holographic dark energy (HDE) model,
describing accelerated expansion of the universe, will be considered. Our
model's stability conditions and its general properties of attractors for
scalar field scripts which control cosmological acceleration will be checked.
The statefinder diagnostic parameters of our model will be compared by today's
observational data and defined methods. However its EoS parameter will be
obtained, too.


title:
Nonlinear Schr\"odinger equations with sum of periodic and vanishing
  potentials and sign-changing nonlinearities

abstract:
  We look for ground state solutions to the following nonlinear Schr\"{o}dinger
equation $$-\Delta u + V(x)u = f(x,u)-\Gamma(x)|u|^{q-2}u\hbox{ on
}\mathbb{R}^N,$$ where $V=V_{per}+V_{loc}\in L^{\infty}(\mathbb{R}^N)$ is the
sum of a periodic potential $V_{per}$ and a localized potential $V_{loc}$,
$\Gamma\in L^{\infty}(\mathbb{R}^N)$ is periodic and $\Gamma(x)\geq 0$ for a.e.
$x\in\mathbb{R}^N$ and $2\leq q<2^*$. We assume that $\inf\sigma(-\Delta+V)>0$,
where $\sigma(-\Delta+V)$ stands for the spectrum of $-\Delta +V$ and $f$ has
the subcritical growth but higher than $\Gamma(x)|u|^{q-2}u$, however the
nonlinearity $f(x,u)-\Gamma(x)|u|^{q-2}u$ may change sign. Although a
Nehari-type monotonicity condition for the nonlinearity is not satisfied we
investigate the existence of ground state solutions being minimizers on the
Nehari manifold.


title: Joint spectra and nilpotent Lie algebras of linear transformations

abstract:
  Given a complex nilpotent finite dimensional Lie algebra of linear
transformations $L$, in a complex finite dimensional vector space $E$, we study
the joint spectra $Sp(L,E)$, $\sigma_{\delta,k}(L,E)$ and
$\sigma_{\pi,k}(L,E)$. We compute them and we prove that they all coincide with
the set of weights of $L$ for $E$. We also give a new interpretation of some
basic module operations of the Lie algebra $L$ in terms of the joint spectra.


title: Nonlinear model order reduction via Dynamic Mode Decomposition

abstract:
  We propose a new technique for obtaining reduced order models for nonlinear
dynamical systems. Specifically, we advocate the use of the recently developed
Dynamic Mode Decomposition (DMD), an equation-free method, to approximate the
nonlinear term. DMD is a spatio-temporal matrix decomposition of a data matrix
that correlates spatial features while simultaneously associating the activity
with periodic temporal behavior. With this decomposition, one can obtain a
fully reduced dimensional surrogate model and avoid the evaluation of the
nonlinear term in the online stage. This allows for an impressive speed up of
the computational cost, and, at the same time, accurate approximations of the
problem. We present a suite of numerical tests to illustrate our approach and
to show the effectiveness of the method in comparison to existing approaches.


title: Half-centered Operators

abstract:
  An operator $T$ on a Hilbert space is called half-centered if the sequence
$T^{*}T,(T^{*})^{2}T^{2},...$ consists of mutually commuting operators. It is a
subclass of the well-studied centered operators. In this paper we give a
condition for when a half-centered operator is centered and prove a structure
theorem for those half-centered operators that satisfies a criteria of a
technical nature.


title: Homotopy linear algebra

abstract:
  By homotopy linear algebra we mean the study of linear functors between
slices of the $\infty$-category of $\infty$-groupoids, subject to certain
finiteness conditions. After some standard definitions and results, we assemble
said slices into $\infty$-categories to model the duality between vector spaces
and profinite-dimensional vector spaces, and set up a global notion of homotopy
cardinality \`a la Baez-Hoffnung-Walker compatible with this duality. We needed
these results to support our work on incidence algebras and M\"obius inversion
over $\infty$-groupoids; we hope that they can also be of independent interest.


title:
Quantum to Classical Transitions via Weak Measurements and
  Post-Selection

abstract:
  This work will incorporate a few related tools for addressing the conceptual
difficulties arising from sewing together classical and quantum mechanics:
deterministic operators, weak measurements and post-selection. Weak
Measurement, based on a very weak von Neumann coupling, is a unique kind of
quantum measurement with numerous theoretical and practical applications. In
contrast to other measurement techniques, it allows to gather a small amount of
information regarding the quantum system, with only a negligible probability of
collapsing it. A single weak measurement yields an almost random outcome, but
when performed repeatedly over a large ensemble, the averaged outcome becomes
increasingly robust and accurate. Importantly, a long sequence of weak
measurements can be thought of as a single projective measurement. I claim in
this work that classical variables appearing in the macro-world, such as centre
of mass, moment of inertia, pressure and average forces, result from a
multitude of quantum weak measurements performed in the micro-world. Here
again, the quantum outcomes are highly uncertain, but the law of large numbers
obliges their convergence to the definite quantities we know from our everyday
lives. By augmenting this description with a final boundary condition and
employing the notion of "classical robustness under time-reversal" I will draw
a quantitative borderline between the classical and quantum regimes. I will
conclude by analyzing the role of macroscopic systems in amplifying and
recording quantum outcomes.


title: Karhunen-Lo\`eve expansion for a generalization of Wiener bridge

abstract:
  We derive a Karhunen-Lo\`eve expansion of the Gauss process $B_t -
g(t)\int_0^1 g'(u)\,d B_u$, $t\in[0,1]$, where $(B_t)_{t\in[0,1]}$ is a
standard Wiener process and $g:[0,1]\to R$ is a twice continuously
differentiable function with $g(0) = 0$ and $\int_0^1 (g'(u))^2\,d u =1$. This
process is an important limit process in the theory of goodness-of-fit tests.
We formulate two special cases with the function
$g(t)=\frac{\sqrt{2}}{\pi}\sin(\pi t)$, $t\in[0,1]$, and $g(t)=t$, $t\in[0,1]$,
respectively. The latter one corresponds to the Wiener bridge over $[0,1]$ from
$0$ to $0$.


title: Electric Conductivity of a hot hadron gas from a kinetic approach

abstract:
  We calculate the electric conductivity of a gas of relativistic particles
with isotropic cross sections using the Boltzmann equation as the starting
point. Our analyses is restricted to elastic collisions. We show the perfect
agreement with previously published numerical results for a massless quark-
gluon plasma, and give results for the electric conductivity of an interacting
hadron gas, employing realistic resonance cross sections. These results for the
electric conductivity of a hot hadron gas, as created in (ultra-)relativistic
heavy-ion collisions, are of rich phenomenological as well as theoretical
interest and can be compared to, e.g., lattice quantum field theory
calculations.


title:
The different energy loss mechanisms of inclusive and b-tagged
  reconstructed jets within ultra-relativistic heavy-ion collisions

abstract:
  The phenomenon of jet quenching provides essential information about the
properties of hot and dense matter created in ultra-relativistic heavy-ion
collisions. Recent results from experiments at the Large Hadron Collider (LHC)
show evidence for an unexpectedly similar suppression of both light and heavy
flavor jets. Furthermore, the role of radiative energy loss of heavy quarks is
still under active discussion within the theoretical community. By employing
the parton cascade Boltzmann Approach to Multi-Parton Scatterings (BAMPS),
which numerically solves the 3+1D Boltzmann equation both for light and heavy
flavor partons, we calculate the nuclear modification factor of inclusive and
b-tagged reconstructed jets in 0-10% central $\sqrt{s_{\rm LHC}}$ = 2.76 ATeV
Pb+Pb collisions. Based on perturbative QCD cross sections we find a
suppression of both light and heavy flavor jets. While the inclusive jets are
slightly too strong suppressed within BAMPS in comparison with data, both
elastic+radiative and only elastic interactions lead to a realistic b-tagged
jet suppression. To further investigate light and heavy flavor energy loss we
predict the R dependence of inclusive and b-tagged jet suppression.
Furthermore, we propose the medium modification of b-tagged jet shapes as an
observable for discriminating between different heavy quark energy loss
scenarios.


title: The next detectors for gravitational wave astronomy

abstract:
  This paper focuses on the next detectors for gravitational wave astronomy
which will be required after the current ground based detectors have completed
their initial observations, and probably achieved the first direct detection of
gravitational waves. The next detectors will need to have greater sensitivity,
while also enabling the world array of detectors to have improved angular
resolution to allow localisation of signal sources. Sect. 1 of this paper
begins by reviewing proposals for the next ground based detectors, and presents
an analysis of the sensitivity of an 8 km armlength detector, which is proposed
as a safe and cost-effective means to attain a 4-fold improvement in
sensitivity. The scientific benefits of creating a pair of such detectors in
China and Australia is emphasised. Sect. 2 of this paper discusses the high
performance suspension systems for test masses that will be an essential
component for future detectors, while sect. 3 discusses solutions to the
problem of Newtonian noise which arise from fluctuations in gravity gradient
forces acting on test masses. Such gravitational perturbations cannot be
shielded, and set limits to low frequency sensitivity unless measured and
suppressed. Sects. 4 and 5 address critical operational technologies that will
be ongoing issues in future detectors. Sect. 4 addresses the design of thermal
compensation systems needed in all high optical power interferometers operating
at room temperature. Parametric instability control is addressed in sect. 5.
Only recently proven to occur in Advanced LIGO, parametric instability
phenomenon brings both risks and opportunities for future detectors. The path
to future enhancements of detectors will come from quantum measurement
technologies. Sect. 6 focuses on the use of optomechanical devices for
obtaining enhanced sensitivity, while sect. 7 reviews a range of quantum
measurement options.


title: On the Compton scattering redistribution function in plasma

abstract:
  Compton scattering is the dominant opacity source in hot neutron stars,
accretion disks around black holes and hot coronae. We collected here a set of
numerical expressions of the Compton scattering redistribution functions for
unpolarized radiation (RF), which are more exact than the widely used
Kompaneets equation. The principal aim of this paper is presentation of the RF
by Guilbert (1981) which is corrected for the computational errors in the
original paper. This corrected RF was used in the series of papers on model
atmosphere computations of hot neutron stars. We have also organized four
existing algorithms for the RF computations into a unified form ready to use in
radiative transfer and model atmosphere codes. The exact method by Nagirner and
Poutanen (1993) was numerically compared to all other algorithms in a very wide
spectral range from hard X-rays to radio waves. Sample computations of the
Compton scattering redistribution functions in thermal plasma were done for
temperatures corresponding to the atmospheres of bursting neutron stars and hot
intergalactic medium. Our formulae are also useful to the study Compton
scattering of unpolarised microwave background radiation in hot intra-cluster
gas and the Sunyaev-Zeldovich effect. We conclude, that the formulae by
Guilbert (1981) and the exact quantum mechanical formulae yield practically the
same redistribution functions for gas temperatures relevant to the atmospheres
of X-ray bursting neutron stars, $T \le 10^8$ K.


title:
The Inward Dispersion of the Neutron Scattering Experiments in HTSC
  Cuprates

abstract:
  The theory of the high temperature superconducting cuprates, which is based
on the condensation of holes into strings in checker-board geometry, was
successful to explain the elastically scattered Neutrons by spin waves. Here it
is extended to analyze the inward dispersion curve of its inelastic
counterpart, up to the resonance energy- . This extension is done by applying
the perturbation theory of the linear response to the condensed strings. The
approximated susceptibility is derived by means of the ring diagram. The
dispersion relation is obtained from the dispersion of the poles of the
susceptibility integral. It is found that the particle anti-particle pair that
yields the susceptibility is the time reversal pair where the particle momentum
is in phase A, and the anti-particle momentum is in phase B. The dispersion is
found to be in agreement with experiment, subject to some suggested
corrections. The weak intensity by the resonance energy, as well as the
dispersion, is speculated to be modified due to interference with spin waves
that are caused by direct spin flip, as in the mother undoped materials.


title:
Hamiltonian engineering for robust quantum state transfer and qubit
  readout in cavity QED

abstract:
  Quantum state transfer into a memory, state shuttling over long distances via
a quantum bus, and high-fidelity readout are important tasks for quantum
technology. Realizing these tasks is challenging in the presence of realistic
couplings to an environment. Here, we introduce and assess protocols that can
be used in cavity QED to perform high-fidelity quantum state transfer and fast
quantum nondemolition qubit readout through Hamiltonian engineering. We show
that high-fidelity state transfer between a cavity and a single qubit can be
performed, even in the limit of strong dephasing due to inhomogeneous
broadening. We generalize this result to state transfer between a cavity and a
logical qubit encoded in a collective mode of a large ensemble of $N$ physical
qubits. Under a decoupling sequence, we show that inhomogeneity in the ensemble
couples two collective bright states to only two other collective modes,
leaving the remaining $N-3$ single-excitation states dark. Moreover, we show
that large signal-to-noise and high single-shot fidelity can be achieved in a
cavity-based qubit readout, even in the weak-coupling limit. These ideas may be
important for novel systems coupling single spins to a microwave cavity.


title: 3-dimensional left-invariant sub-Lorentzian contact structures

abstract:
  We provide a classification of $ts$-invariant sub-Lorentzian structures on
$3$ dimensional contact Lie groups. Our approach is based on invariants arising
form the construction of a normal Cartan connection.


title: Symmetries constrain dynamics in a family of balanced neural networks

abstract:
  We examine a family of random firing-rate neural networks in which we enforce
the neurobiological constraint of Dale's Law --- each neuron makes either
excitatory or inhibitory connections onto its post-synaptic targets. We find
that this constrained system may be described as a perturbation from a system
with non-trivial symmetries. We analyze the symmetric system using the tools of
equivariant bifurcation theory, and demonstrate that the symmetry-implied
structures remain evident in the perturbed system. In comparison, spectral
characteristics of the network coupling matrix are relatively uninformative
about the behavior of the constrained system.


title: Quasi-periodic solutions of forced Kirchoff equation

abstract:
  In this paper we prove the existence and the stability of small-amplitude
quasi-periodic solutions with Sobolev regularity, for the 1-dimensional forced
Kirchoff equation with periodic boundary conditions. This is the first KAM
result for a quasi-linear wave-type equation. The main difficulties are: $(i)$
the presence of the highest order derivative in the nonlinearity which does not
allow to apply the classical KAM scheme, $(ii)$ the presence of double
resonances, due to the double multiplicity of the eigenvalues of $-
\partial_{xx}$. The proof is based on a Nash-Moser scheme in Sobolev class. The
main point concerns the invertibility of the linearized operator at any
approximate solution and the proof of tame estimates for its inverse in high
Sobolev norm. To this aim, we conjugate the linearized operator to a $2 \times
2$, time independent, block-diagonal operator. This is achieved by using {\it
changes of variables} induced by diffeomorphisms of the torus, {\it
pseudo-differential} operators and a KAM {\it reducibility} scheme in Sobolev
class.


title: K\"ahler-Einstein metrics and volume minimization

abstract:
  We prove that if a $\mathbb{Q}$-Fano variety $V$ specially degenerates to a
K\"{a}hler-Einstein $\mathbb{Q}$-Fano variety $V$, then for any ample Cartier
divisor $H=-r^{-1} K_V$ with $r\in \mathbb{Q}_{>0}$, the normalized volume
$\widehat{\rm vol}(v)=A_{\mathcal{C}}^n(v)\cdot {\rm vol}(v)$ is globally
minimized at the canonical valuation ${\rm ord}_V$ among all real valuations
which are centered at the vertex of the affine cone $\mathcal{C}:=C(V,H)$. This
is also generalized to the logarithmic and the orbifold setting. As a
consequence, we complete the confirmation of a conjecture in [arXiv:1511.08164]
on an equivalent characterization of K-semistability for any smooth Fano
manifold. We also prove that the valuation associated to the Reeb vector field
of a smooth Sasaki-Einstein metric minimizes $\widehat{\rm vol}$ over the
corresponding K\"ahler cone. These results strengthen the minimization result
of Martelli-Sparks-Yau [Martelli et al 08].


title:
Current-controlled Spin Precession of Quasi-Stationary Electrons in a
  Cubic Spin-Orbit Field

abstract:
  Space- and time-resolved measurements of spin drift and diffusion are
performed on a GaAs-hosted two-dimensional electron gas. For spins where
forward drift is compensated by backward diffusion, we find a precession
frequency in absence of an external magnetic field. The frequency depends
linearly on the drift velocity and is explained by the cubic Dresselhaus
spin-orbit interaction, for which drift leads to a spin precession angle twice
that of spins that diffuse the same distance.


title: Neutrino induced 1-pion production

abstract:
  Neutrino-induced pion production constitutes an important contribution to
neutrino-nucleus scattering cross sections at intermediate energies. A deep
understanding of this process is mandatory for a correct interpretation of
neutrino-oscillation experiments. We aim at contributing to the ongoing effort
to understand the various experimental results obtained by different
collaborations in a wide range of energies. In particular, in this work we
analyze recent MiniBooNE and MINERvA charged-current neutrino 1-pion production
data. We use a relativistic theoretical approach which accounts for resonant
and non-resonant 1-pion production contributions.


title: Eberlein oligomorphic groups

abstract:
  We study the Fourier--Stieltjes algebra of Roelcke precompact,
non-archimedean, Polish groups and give a model-theoretic description of the
Hilbert compactification of these groups. We characterize the family of such
groups whose Fourier--Stieltjes algebra is dense in the algebra of weakly
almost periodic functions: those are exactly the automorphism groups of
$\aleph_0$-stable, $\aleph_0$-categorical structures. This analysis is then
extended to all semitopological semigroup compactifications $S$ of such a
group: $S$ is Hilbert-representable if and only if it is an inverse semigroup.
We also show that every factor of the Hilbert compactification is
Hilbert-representable.


title: Abundances of 59Co and 59Ni in the cosmic ray flux

abstract:
  Two main hypotheses for the origin of Galactic cosmic rays are the
"supernova" and "superbubble" origin hypotheses. We analyse the evidence for
the superbubble hypothesis provided by the measurements of the relativive
abundances of isotopes of cobalt and nickel in the cosmic ray flux. We compare
the measured upper limit on the abundance of 59Ni in the cosmic ray flux with
the 59Ni abundance predictions of the up-to-date stellar evolution models.
Non-detection of 59Ni in the cosmic ray flux has previously been attributed to
a large time delay of the order of 1e5 yr between the moment of supernova
explosion and the onset of particle acceleration process. This large time delay
was considered as an argument in favour of the "superbubble" scenario. We show
that the recent calculation of the 59Ni yield of massive stars, which takes
into account the initial mass range up to 120 solar masses and includes stellar
rotation, results in prediction of low 59Ni abundance relative to its decay
product 59Co. The predicted abundance is consistent with the upper bound on
59Ni abundance in the cosmic ray flux for the supernova parameters assumed.
This result removes the necessity of decay of 59Ni in the time interval between
the supernova explosion and the onset of acceleration process and restores the
consistency of measurements of 59Ni / 59Co abundances with the "supernova"
hypothesis of the CR origin.


title:
Quantum calculation of the Vavilov-Cherenkov radiation by twisted
  electrons

abstract:
  We present the detailed quantum electrodynamical description of
Vavilov-Cherenkov radiation emitted by a relativistic twisted electron in the
transparent medium. Simple expressions for the spectral and spectral-angular
distributions as well as for the polarization properties of the emitted
radiation are obtained. Unlike the plane-wave case, the twisted electron
produces radiation within the annular angular region, with enhancement towards
its boundaries. Additionally, the emitted photons can have linear polarization
not only in the scattering plane but also in the orthogonal direction. We find
that the Vavilov-Cherenkov radiation emitted by an electron in a superposition
of two vortex states exhibits a strong azimuthal asymmetry. Thus, the
Vavilov-Cherenkov radiation offers itself as a convenient diagnostic tool of
such electrons and complements the traditional microscopic imaging.


title: Query Reranking As A Service

abstract:
  The ranked retrieval model has rapidly become the de facto way for search
query processing in client-server databases, especially those on the web.
Despite of the extensive efforts in the database community on designing better
ranking functions/mechanisms, many such databases in practice still fail to
address the diverse and sometimes contradicting preferences of users on tuple
ranking, perhaps (at least partially) due to the lack of expertise and/or
motivation for the database owner to design truly effective ranking functions.
This paper takes a different route on addressing the issue by defining a novel
{\em query reranking problem}, i.e., we aim to design a third-party service
that uses nothing but the public search interface of a client-server database
to enable the on-the-fly processing of queries with any user-specified ranking
functions (with or without selection conditions), no matter if the ranking
function is supported by the database or not. We analyze the worst-case
complexity of the problem and introduce a number of ideas, e.g., on-the-fly
indexing, domination detection and virtual tuple pruning, to reduce the
average-case cost of the query reranking algorithm. We also present extensive
experimental results on real-world datasets, in both offline and live online
systems, that demonstrate the effectiveness of our proposed techniques.


title: Distinction of the Steinberg representation for inner forms of $GL(n)$

abstract:
  Let $F$ be a non archimedean local field of characteristic not $2$. Let $D$
be a division algebra of dimension $d^2$ over its center $F$, and $E$ a
quadratic extension of $F$. If $m$ is a positive integer, to a character $\chi$
of $E^*$, one can attach the Steinberg representation $St(\chi)$ of
$G=GL(m,D\otimes_F E)$. Let $H$ be the group $GL(m,D)$, we prove that
$St(\chi)$ is $H$-distinguished if and only if $\chi_{|F^*}$ is the quadratic
character $\eta_{E/F}^{md-1}$, where $\eta_{E/F}$ is the character of $F^*$
with kernel the norms of $E^*$. We also get multiplicity one for the space of
invariant linear forms. As a corollary, we see that the Jacquet-Langlands
correspondence preserves distinction for Steinberg representations.


title:
Critical relaxation with overdamped quasiparticles in open quantum
  systems

abstract:
  We study the late-time relaxation following a quench in a driven-dissipative
quantum many-body system. We consider the open Dicke model, describing the
infinite-range interactions between $N$ atoms and a single, lossy
electromagnetic mode. We show that the dynamical phase transition at a critical
atom-light coupling is characterized by the interplay between reservoir-driven
and intrinsic relaxation processes. Above the critical coupling, small
fluctuations in the occupation of the dominant quasiparticle-mode start to grow
in time while the quasiparticle lifetime remains finite due to losses. Near the
critical interaction strength we observe a crossover between exponential and
power-law $1/\tau$ relaxation, the latter driven by collisions between
quasiparticles. For a quench exactly to the critical coupling, the power-law
relaxation extends to infinite times, but the finite lifetime of quasiparticles
prevents ageing to appear. We predict our results to be accessible to quench
experiments with ultracold bosons in optical resonators.


title:
A Matching Game for Data Trading in Operator-Supervised User-Provided
  Networks

abstract:
  In this paper, we consider a recent cellular network connection paradigm,
known as user-provided network (UPN), where users share their connectivity and
act as an access point for other users. To incentivize user participation in
this network, we allow the users to trade their data plan and obtain some
profits by selling and buying leftover data capacities (caps) from each other.
We formulate the buyers and sellers association for data trading as a matching
game. In this game, buyers and sellers rank one another based on preference
functions that capture buyers' data demand and QoS requirements, sellers'
available data and energy resources. We show that these preferences are
interdependent and influenced by the existing network-wide matching. For this
reason, the game can be classified as a one-to-many matching game with
externalities. To solve this game, a distributed algorithm that combines
notions from matching theory and market equilibrium is proposed. The algorithm
enables the players to self-organize into a stable matching and dynamic
adaptation of price to data demand and supply. The properties of the resulting
matching are discussed. Moreover, the price benchmark for the users to join the
UPN and the operator gain are also determined. Simulation results show that the
proposed algorithm yields an improvement of the average utility per user up to
25% and 50% relative to random matching and worst case utility, respectively.


title: Accurate exchange-correlation energies for the warm dense electron gas

abstract:
  Density matrix quantum Monte Carlo (DMQMC) is used to sample exact-on-average
$N$-body density matrices for uniform electron gas systems of up to 10$^{124}$
matrix elements via a stochastic solution of the Bloch equation. The results of
these calculations resolve a current debate over the accuracy of the data used
to parametrize finite-temperature density functionals. Exchange-correlation
energies calculated using the real-space restricted path-integral formalism and
the $k$-space configuration path-integral formalism disagree by up to
$\sim$$10$\% at certain reduced temperatures $T/T_F \le 0.5$ and densities $r_s
\le 1$. Our calculations confirm the accuracy of the configuration
path-integral Monte Carlo results available at high density and bridge the gap
to lower densities, providing trustworthy data in the regime typical of
planetary interiors and solids subject to laser irradiation. We demonstrate
that DMQMC can calculate free energies directly and present exact free energies
for $T/T_F \ge 1$ and $r_s \le 2$.