title: The Stellar Halo in the Inner Milky Way: Predicted Shape and Kinematics

abstract:
  We have used N-body simulations for the Milky Way to investigate the
kinematic and structural properties of the old metal-poor stellar halo in the
barred inner region of the Galaxy. We find that the extrapolation of the
density distribution for bulge RR Lyrae stars, $\rho\sim r^{-3}$, approximately
matches the number density of RR Lyrae in the nearby stellar halo. We follow
the evolution of such a tracer population through the formation and evolution
of the bar and box/peanut bulge in the N-body model. We find that its density
distribution changes from oblate to triaxial, and that it acquires slow
rotation in agreement with recent measurements. The maximum radial velocity is
$\sim15-25$ km/s at $| l|\!=10^\circ-30^\circ$, and the velocity dispersion is
$\sim120$ km/s. Even though the simulated metal-poor halo in the bulge has a
barred shape, just $12\%$ of the orbits follow the bar, and it does not trace
the peanut/X structure. With these properties, the RR Lyrae population in the
Galactic bulge is consistent with being the inward extension of the Galactic
metal-poor stellar halo.


title:
Novel sampling formulas associated with quaternionic prolate spheroidal
  wave functions

abstract:
  The Whittaker-Shannon-Kotel'nikov (WSK) sampling theorem provides a
reconstruction formula for the bandlimited signals. In this paper, a novel kind
of the WSK sampling theorem is established by using the theory of quaternion
reproducing kernel Hilbert spaces. This generalization is employed to obtain
the novel sampling formulas for the bandlimited quaternion-valued signals. A
special case of our result is to show that the 2D generalized prolate
spheroidal wave signals obtained by Slepian can be used to achieve a sampling
series of cube-bandlimited signals. The solutions of energy concentration
problems in quaternion Fourier transform are also investigated.


title: Global analysis by hidden symmetry

abstract:
  Hidden symmetry of a G'-space X is defined by an extension of the G'-action
on X to that of a group G containing G' as a subgroup. In this setting, we
study the relationship between the three objects:
  (A) global analysis on X by using representations of G (hidden symmetry);
  (B) global analysis on X by using representations of G';
  (C) branching laws of representations of G when restricted to the subgroup
G'.
  We explain a trick which transfers results for finite-dimensional
representations in the compact setting to those for infinite-dimensional
representations in the noncompact setting when $X_C$ is $G_C$-spherical.
Applications to branching problems of unitary representations, and to spectral
analysis on pseudo-Riemannian locally symmetric spaces are also discussed.


title: Skyrmion-induced subgap states in p-wave superconductors

abstract:
  In s-wave systems, it has been theoretically shown that a ferromagnetic film
hosting a skyrmion can induce a bound state embedded in the opposite-spin
continuum. In this work, we consider a case of skyrmion-induced state in a
p-wave superconductor. We find that the skyrmion induces a bound state that
generally resides \emph{within} the spectral gap and is isolated from all other
states, in contrast to the case of conventional superconductors. To this end,
we derive an approximate expression for the $T$-matrix, through which we
calculate the spin-polarized local density of states which is observable in
scanning tunneling microscopy measurements. We find the unique spectroscopic
features of the skyrmion-induced bound state and discuss how our predictions
could be employed as novel experimental probes for p-wave superconducting
states.


title: Finite time distributed averaging over ring networks

abstract:
  We consider a multi-agent system where each agent has its own estimate of a
given quantity and the goal is to reach consensus on the average. To this
purpose, we propose a distributed consensus algorithm that guarantees
convergence to the average in a finite number of iterations. The algorithm is
tailored to ring networks with bidirectional pairwise communications. If the
number of agents $m$ is even, say $m=2n$, then, the number of iterations needed
is equal to $n$, which in this case is the diameter of the network, whereas the
number of iterations grows to $3n$ if the number of agents is odd and equal to
$m=2n+1$.


title: Thermal Fluctuations Of Stable Quantum ADS Kerr-Newman Black Hole

abstract:
  We have already derived the Criteria for thermal stability of charged
rotating black holes in any dimension , for horizon areas that are large
relative to the Planck area (in these dimensions). The derivation is done by
using results of loop quantum gravity and equilibrium statistical mechanics of
the Grand Canonical ensemble. It is also shown there [1] that in four
dimensional spacetime, ADS Kerr-Newman Black hole is thermally stable. In this
paper, the expectation values of fluctuations of horizon area,charge and
angular momentum of stable ADS black hole are calculated. Interestingly, it is
found that leading order fluctuations of charge and angular momentum , in large
horizon area limit , are independent of the values of charge and angular
momentum at equilibrium.


abstract:
  We report on the Parallel Session BH4 "Gravitational fields with sources:
From compact objects to black holes" of the 14th Marcel Grossmann Meeting held
at Sapienza University of Rome in 2015.


title:
Improved Performances in Subsonic Flows of an SPH Scheme with Gradients
  Estimated using an Integral Approach

abstract:
  In this paper we present results from a series of hydrodynamical tests aimed
at validating the performance of a smoothed particle hydrodynamics (SPH)
formulation in which gradients are derived from an integral approach. We
specifically investigate the code behavior with subsonic flows, where it is
well known that zeroth-order inconsistencies present in standard SPH make it
particularly problematic to correctly model the fluid dynamics. In particular
we consider the Gresho-Chan vortex problem, the growth of Kelvin-Helmholtz
instabilities, the statistics of driven subsonic turbulence and the cold
Keplerian disc problem. We compare simulation results for the different tests
with those obtained, for the same initial conditions, using standard SPH. We
also compare the results with the corresponding ones obtained previously with
other numerical methods, such as codes based on a moving-mesh scheme or
Godunov-type Lagrangian meshless methods. We quantify code performances by
introducing error norms and spectral properties of the particle distribution,
in a way similar to what was done in other works. We find that the new SPH
formulation exhibits strongly reduced gradient errors and outperforms standard
SPH in all of the tests considered. In fact, in terms of accuracy we find good
agreement between the simulation results of the new scheme and those produced
using other recently proposed numerical schemes. These findings suggest that
the proposed method can be successfully applied for many astrophysical problems
in which the presence of subsonic flows previously limited the use of SPH, with
the new scheme now being competitive in these regimes with other numerical
methods.


title:
Incremental Nonlinear System Identification and Adaptive Particle
  Filtering Using Gaussian Process

abstract:
  An incremental/online state dynamic learning method is proposed for
identification of the nonlinear Gaussian state space models. The method embeds
the stochastic variational sparse Gaussian process as the probabilistic state
dynamic model inside a particle filter framework. Model updating is done at
measurement sample rate using stochastic gradient descent based optimization
implemented in the state estimation filtering loop. The performance of the
proposed method is compared with state-of-the-art Gaussian process based batch
learning methods. Finally, it is shown that the state estimation performance
significantly improves due to the online learning of state dynamics.


title:
Identifying space-dependent coefficients and the order of fractionality
  in fractional advection diffusion equation

abstract:
  Tracer tests in natural porous media sometimes show abnormalities that
suggest considering a fractional variant of the Advection Diffusion Equation
supplemented by a time derivative of non-integer order. We are describing an
inverse method for this equation: it finds the order of the fractional
derivative and the coefficients that achieve minimum discrepancy between
solution and tracer data. Using an adjoint equation divides the computational
effort by an amount proportional to the number of freedom degrees, which
becomes large when some coefficients depend on space. Method accuracy is
checked on synthetical data, and applicability to actual tracer test is
demonstrated.

categories: physics.class-ph math-ph math.MP physics.comp-ph


title:
First Ex-Vivo Validation of a Radioguided Surgery Technique with beta-
  Radiation

abstract:
  Purpose: A radio-guided surgery technique with beta- -emitting radio-tracers
was suggested to overcome the effect of the large penetration of gamma
radiation. The feasibility studies in the case of brain tumors and abdominal
neuro-endocrine tumors were based on simulations starting from PET images with
several underlying assumptions. This paper reports, as proof-of-principle of
this technique, an ex-vivo test on a meningioma patient. This test allowed to
validate the whole chain, from the evaluation of the SUV of the tumor, to the
assumptions on the bio-distribution and the signal detection.
  Methods: A patient affected by meningioma was administered 300 MBq of
90Y-DOTATOC. Several samples extracted from the meningioma and the nearby Dura
Mater were analyzed with a beta- probe designed specifically for this
radio-guided surgery technique. The observed signals were compared both with
the evaluation from the histology and with the Monte Carlo simulation.
  Results: we obtained a large signal on the bulk tumor (105 cps) and a
significant signal on residuals of $\sim$0.2 ml (28 cps). We also show that
simulations predict correctly the observed yields and this allows us to
estimate that the healthy tissues would return negligible signals (~1 cps).
This test also demonstrated that the exposure of the medical staff is
negligible and that among the biological wastes only urine has a significant
activity.
  Conclusions: This proof-of-principle test on a patient assessed that the
technique is feasible with negligible background to medical personnel and
confirmed that the expectations obtained with Monte Carlo simulations starting
from diagnostic PET images are correct.


title: Scalable and Cost Efficient Algorithms for Virtual CDN Migration

abstract:
  Virtual Content Delivery Network (vCDN) migration is necessary to optimize
the use of resources and improve the performance of the overall SDN/NFV-based
CDN function in terms of network operator cost reduction and high streaming
quality. It requires intelligent and enticed joint SDN/NFV migration algorithms
due to the evident huge amount of traffic to be delivered to end customers of
the network. In this paper, two approaches for finding the optimal and near
optimal path placement(s) and vCDN migration(s) are proposed (OPAC and HPAC).
Moreover, several scenarios are considered to quantify the OPAC and HPAC
behaviors and to compare their efficiency in terms of migration cost, migration
time, vCDN replication number, and other cost factors. Then, they are
implemented and evaluated under different network scales. Finally, the proposed
algorithms are integrated in an SDN/NFV framework. Index Terms: vCDN; SDN/NFV
Optimization; Migration Algorithms; Scalability Algorithms.


title:
Exact scaling laws for helical three-dimensional two-fluid turbulent
  plasmas

abstract:
  We derive exact scaling laws for a three-dimensional incompressible helical
two-fluid plasma, without the assumption of isotropy. For each ideal invariant
of the two-fluid model, i.e. the total energy, the electron helicity and the
proton helicity, we derive simple scaling laws in terms of two-point increments
correlation functions expressed in terms of the velocity field of each species
and the magnetic field. These variables are appropriate for comparison with
\textit{in-situ} measurements in the solar wind at different spatial ranges and
data from numerical simulations. Finally, with the exact scaling laws and
dimensional analysis we predict the magnetic energy and electron helicity
spectra for different ranges of scales.


title:
Pattern Coding Meets Censoring: (almost) Adaptive Coding on Countable
  Alphabets

abstract:
  Adaptive coding faces the following problem: given a collection of source
classes such that each class in the collection has non-trivial minimax
redundancy rate, can we design a single code which is asymptotically minimax
over each class in the collection? In particular, adaptive coding makes sense
when there is no universal code on the union of classes in the collection. In
this paper, we deal with classes of sources over an infinite alphabet, that are
characterized by a dominating envelope. We provide asymptotic equivalents for
the redundancy of envelope classes enjoying a regular variation property. We
finally construct a computationally efficient online prefix code, which
interleaves the encoding of the so-called pattern of the message and the
encoding of the dictionary of discovered symbols. This code is shown to be
adaptive, within a $\log\log n$ factor, over the collection of regularly
varying envelope classes. The code is both simpler and less redundant than
previously described contenders. In contrast with previous attempts, it also
covers the full range of slowly varying envelope classes.


title:
On Constructing Persistent Identifiers with Persistent Resolution
  Targets

abstract:
  Persistent Identifiers (PID) are the foundation referencing digital assets in
scientific publications, books, and digital repositories. In its realization,
PIDs contain metadata and resolving targets in form of URLs that point to data
sets located on the network. In contrast to PIDs, the target URLs are typically
changing over time; thus, PIDs need continuous maintenance -- an effort that is
increasing tremendously with the advancement of e-Science and the advent of the
Internet-of-Things (IoT). Nowadays, billions of sensors and data sets are
subject of PID assignment. This paper presents a new approach of embedding
location independent targets into PIDs that allows the creation of
maintenance-free PIDs using content-centric network technology and overlay
networks. For proving the validity of the presented approach, the Handle PID
System is used in conjunction with Magnet Link access information encoding,
state-of-the-art decentralized data distribution with BitTorrent, and Named
Data Networking (NDN) as location-independent data access technology for
networks. Contrasting existing approaches, no green-field implementation of PID
or major modifications of the Handle System is required to enable
location-independent data dissemination with maintenance-free PIDs.


title:
Color center fluorescence and spin manipulation in single crystal,
  pyramidal diamond tips

abstract:
  We investigate bright fluorescence of nitrogen (NV)- and silicon-vacancy
color centers in pyramidal, single crystal diamond tips which are commercially
available as atomic force microscope probes. We coherently manipulate NV
electronic spin ensembles with $T_2 = 7.7(3)\,\mu$s. Color center lifetimes in
different tip heights indicate effective refractive index effects and
quenching. Using numerical simulations, we verify enhanced photon rates from
emitters close to the pyramid apex; a situation promising for scanning probe
sensing.

categories: cond-mat.mtrl-sci cond-mat.mes-hall physics.optics quant-ph


title: Empirical Chaos Processes and Blind Deconvolution

abstract:
  This paper investigates conditions under which certain kinds of systems of
bilinear equations have a unique structured solution. In particular, we look at
when we can recover vectors $\boldsymbol{w},\boldsymbol{q}$ from observations
of the form \[ y_{\ell} =
<\boldsymbol{w},\boldsymbol{b}_{\ell}><\boldsymbol{c}_{\ell},\boldsymbol{q}>,
\quad \ell = 1,\ldots,L, \] where $\boldsymbol{b}_\ell,\boldsymbol{c}_\ell$ are
known. We show that if $\boldsymbol{w}\in\mathbb{C}^{M_1}$ and
$\boldsymbol{q}\in\mathbb{C}^{M_2}$ are sparse, with no more than $K$ and $N$
nonzero entries, respectively, and the
$\boldsymbol{b}_\ell,\boldsymbol{c}_\ell$ are generic, selected as independent
Gaussian random vectors, then $\boldsymbol{w},\boldsymbol{q}$ are uniquely
determined from \[
  L \geq \mathrm{Const}\cdot (K+N)\log^5(M_1M_2) \] such equations with high
probability.
  The key ingredient in our analysis is a uniform probabilistic bound on how
far a random process of the form \[Z(\boldsymbol{X}) =
\sum_{\ell=1}^L|\boldsymbol{b}_\ell^*\boldsymbol{X}\boldsymbol{c}_\ell|^2 \]
deviates from its mean over a set of structured matrices
$\boldsymbol{X}\in\mathcal{X}$. As both $\boldsymbol{b}_\ell$ and
$\boldsymbol{c}_\ell$ are random, this is a specialized type of $4$th order
chaos; we refer to $Z(\boldsymbol{X})$ as an {\em empirical chaos process}.
Bounding this process yields a set of general conditions for when the map
$\boldsymbol{X}\rightarrow
\{\boldsymbol{b}_\ell^*\boldsymbol{X}\boldsymbol{c}_\ell\}_{\ell=1}^L$ is a
restricted isometry over the set of matrices $\mathcal{X}$. The conditions are
stated in terms of general geometric properties of the set $\mathcal{X}$, and
are explicitly computed for the case where $\mathcal{X}$ is the set of matrices
that are simultaneously sparse and low rank.


title: Solutions of Fully Nonlinear Nonlocal Systems

abstract:
  In this paper we consider the system involving fully nonlinear nonlocal
operators: $$ \left\{ \begin{array}{ll} F_{\alpha}(u(x)) = C_{n,\alpha} PV
\int_{{R}^n} \frac{G(u(x)-u(y))}{|x-y|^{n+\alpha}} dy=f(v(x)), F_{\beta}(v(x))
= C_{n,\beta} PV \int_{{R}^n} \frac{G(v(x)-v(y))}{|x-y|^{n+\beta}} dy=g(u(x)).
\end{array} \right. $$
  A \textit{narrow region principle} and a \textit{decay at infinity} for the
system for carrying on the method of moving planes are established. Then we
prove the radial symmetry and monotonicity for positive solutions to the
nonlinear system in the whole space. Non-existence of positive solutions to the
nonlinear system on a half space is proved.


title: Axion decay constants at special points in type II string theory

abstract:
  We propose the mechanism to disentangle the decay constant of closed string
axion from the string scale in the framework of type II string theory on
Calabi-Yau manifold. We find that the quantum and geometrical corrections in
the prepotential that arise at some special points in the moduli space widen
the window of axion decay constant. In particular, around the small complex
structure points, the axion decay constant becomes significantly lower than the
string scale. We also discuss the moduli stabilization leading to the
phenomenologically attractive low-scale axion decay constant.


title: Astroparticles and tests of Lorentz invariance

abstract:
  Searches for violations of Lorentz invariance using cosmic rays, gamma rays,
and astrophysical neutrinos and the prospects for future tests using cosmic-ray
showers are presented.


title: Monochromatic solutions to $x + y = z^2$

abstract:
  Suppose that $\mathbb{N}$ is $2$-coloured. Then there are infinitely many
monochromatic solutions to $x + y = z^2$. On the other hand, there is a
$3$-colouring of $\mathbb{N}$ with only finitely many monochromatic solutions
to this equation.


title:
Chemical composition of evolved stars in the young open clusters NGC
  4609 and NGC 5316

abstract:
  High-resolution spectral analysis is performed for the first time in evolved
stars of two young open clusters: NGC 4609 and NGC 5316, of about 80 and 100
Myr in age, respectively, and turn-off masses above 5 Msun. Stellar evolution
models predict an extra-mixing event in evolved stars, which follows the first
dredge-up and happens later on the red giant branch. However, it is still not
understood how this process affects stars of different masses. In this study,
we determine abundances of the mixing sensitive elements carbon and nitrogen,
carbon isotope 12C/13C ratios, as well as 20 other elements produced by
different nucleosynthetic processes (O, Na, Mg, Al, Si, Ca, Sc, Ti, Cr, Mn, Co,
Ni, Y, Zr, Ba, La, Ce, Pr, Nd, and Eu). We compared our results with the latest
theoretical models of evolutionary mixing processes. We find that the obtained
12C/13C and C/N ratios and [Na/Fe] agree quite well with the model which takes
into account thermohaline- and rotation-induced mixing but within error limits
also agree with the standard first dredge-up model. Comparison of oxygen,
magnesium and other alpha-elements with theoretical models of Galactic chemical
evolution revealed that both clusters follow the thin disk alpha-element
trends. Neutron-capture element abundances in NGC 4609 are apparently
reflecting its birthplace in the thin disk, while NGC 5316 has marginally
higher abundances, which would indicate its birthplace in an environment more
enriched with neutron-capture elements.


title:
A near-threshold RISC-V core with DSP extensions for scalable IoT
  Endpoint Devices

abstract:
  Endpoint devices for Internet-of-Things not only need to work under extremely
tight power envelope of a few milliwatts, but also need to be flexible in their
computing capabilities, from a few kOPS to GOPS. Near-threshold(NT) operation
can achieve higher energy efficiency, and the performance scalability can be
gained through parallelism. In this paper we describe the design of an
open-source RISC-V processor core specifically designed for NT operation in
tightly coupled multi-core clusters. We introduce instruction-extensions and
microarchitectural optimizations to increase the computational density and to
minimize the pressure towards the shared memory hierarchy. For typical
data-intensive sensor processing workloads the proposed core is on average 3.5x
faster and 3.2x more energy-efficient, thanks to a smart L0 buffer to reduce
cache access contentions and support for compressed instructions. SIMD
extensions, such as dot-products, and a built-in L0 storage further reduce the
shared memory accesses by 8x reducing contentions by 3.2x. With four
NT-optimized cores, the cluster is operational from 0.6V to 1.2V achieving a
peak efficiency of 67MOPS/mW in a low-cost 65nm bulk CMOS technology. In a low
power 28nm FDSOI process a peak efficiency of 193MOPS/mW(40MHz, 1mW) can be
achieved.


title: Fluctuation theory for Markov random walks

abstract:
  Two fundamental theorems by Spitzer/Erickson and Kesten/Maller on the
fluctuation type (positive divergence, negative divergence or oscillation) of a
real-valued random walk $(S_{n})_{n\ge 0}$ with iid increments
$X_{1},X_{2},\ldots$ and the existence of moments of various related quantities
like the first passage into $[x,\infty)$ and the last exit time from
$(-\infty,x]$ for arbitrary $x\in\mathbb{R}_{\geqslant}$ are studied in the
Markov-modulated situation when the $X_{n}$ are governed by a positive
recurrent Markov chain $M=(M_{n})_{n\ge 0}$ on a countable state space
$\mathcal{S}$, thus for a Markov random walk $(M_{n},S_{n})_{n\ge 0}$. Our
approach is based on the natural strategy to draw on the results in the iid
case for the embedded ordinary random walks $(S_{\tau_{n}(i)})_{n\ge 0}$, where
$\tau_{1}(i),\tau_{2}(i),\ldots$ denote the successive return times of $M$ to
state $i$, and an analysis of the excursions of the walk between these epochs.
However, due to these excursions, generalizations of the afore-mentioned
theorems are not one-to-one extensions of those in the iid case and cannot be
as illustrated by a number of counterexamples. In fact, various excursion
measures will have to be introduced so as to characterize the existence of
moments of different quantities.


title:
A parameter-free method to extract the superconductor's $J_c(B,\theta)$
  field-dependence from in-field current-voltage characteristics of HTS tapes

abstract:
  The estimation of the critical current ($I_c$) and AC losses of
high-temperature superconductor (HTS) devices through modeling and simulation
requires the knowledge of the critical current density ($J_c$) of the
superconducting material. This $J_c$ is in general not constant and depends
both on the magnitude ($B_{loc}$) and the direction ($\theta$, relative to the
tape) of the local magnetic flux density. In principle, $J_c(B_{loc},\theta)$
can be obtained from the experimentally measured critical current
$I_c(B_a,\theta)$, where $B_a$ is the magnitude of the applied magnetic field.
However, for applications where the superconducting materials experience a
local field that is close to the self field of an isolated conductor, obtaining
$J_c(B_{loc},\theta)$ form $I_c(B_a,\theta)$ is not a trivial task. It is
necessary to solve an inverse problem to correct for the contribution derived
from the self field. The methods presented in the literature comprise a series
of approaches dealing with different degrees of mathematical regularization,
such as the use of brute force or optimization methods to fit the parameters of
preconceived non linear formulas. In this contribution, we present a
parameter-free method that provides excellent reproduction of experimental data
and requires no human interaction or preconception of the $J_c$ dependence with
respect to the magnetic field. In particular, it allows going from the
experimental data to a ready-to-run $J_c(B_{loc},\theta)$ model in a few
minutes.


title: Non-stationary phase of the MALA algorithm

abstract:
  The Metropolis-Adjusted Langevin Algorithm (MALA) is a Markov Chain Monte
Carlo method which creates a Markov chain reversible with respect to a given
target distribution, pi^N, with Lebesgue density on R^N; it can hence be used
to approximately sample the target distribution. When the dimension N is large
a key question is to determine the computational cost of the algorithm as a
function of N. One approach to this question, which we adopt here, is to derive
diffusion limits for the algorithm. The family of target measures that we
consider in this paper are, in general, in non-product form and are of interest
in applied problems as they arise in Bayesian nonparametric statistics and in
the study of conditioned diffusions. Furthermore, we study the situation, which
arises in practice, where the algorithm is started out of stationarity. We
thereby significantly extend previous works which consider either only measures
of product form, when the Markov chain is started out of stationarity, or
measures defined via a density with respect to a Gaussian, when the Markov
chain is started in stationarity. We prove that, in the non-stationary regime,
the computational cost of the algorithm is of the order N^(1/2) with dimension,
as opposed to what is known to happen in the stationary regime, where the cost
is of the order N^(1/3).


title:
Sub-mm free-free emission from the winds of massive stars in the age of
  ALMA

abstract:
  The thermal radio and sub-mm emission from the winds of massive stars is
investigated and the contribution to the emission due to the stellar wind
acceleration region and clumping of the wind is quantified. Building upon
established theory, a method for calculating the thermal radio and sub-mm
emission using results for a line-driven stellar outflow according to Castor,
Abbott & Klein (1975) is presented. The results show strong variation of the
spectral index for 10 2 GHz < {\nu} < 10 4 GHz. This corresponds both to the
wind acceleration region and clumping of the wind, leading to a strong
dependence on the wind velocity law and clumping parameters. The Atacama Large
Millimeter/sub-mm Array (ALMA) is the first observatory to have both the
spectral window and sensitivity to observe at the high frequencies required to
probe the acceleration regions of massive stars. The deviations in the
predicted flux levels as a result of the inclusion of the wind acceleration
region and clumping are sufficient to be detected by ALMA, through deviations
in the spectral index in different portions of the radio/sub-mm spectra of
massive stars, for a range of reasonable mass-loss rates and distances.
Consequently both mechanisms need to be included to fully understand the
mass-loss rates of massive stars.


title:
On the set of uniquely decodable codes with a given sequence of code
  word lengths

abstract:
  For every natural number $n\geq 2$ and every finite sequence $L$ of natural
numbers, we consider the set $UD_n(L)$ of all uniquely decodable codes over an
$n$-letter alphabet with the sequence $L$ as the sequence of code word lengths,
as well as its subsets $PR_n(L)$ and $FD_n(L)$ consisting of, respectively, the
prefix codes and the codes with finite delay. We derive the estimation for the
quotient $|UD_n(L)|/|PR_n(L)|$, which allows to characterize those sequences
$L$ for which the equality $PR_n(L)=UD_n(L)$ holds. We also characterize those
sequences $L$ for which the equality $FD_n(L)=UD_n(L)$ holds.


title:
Majorana zero modes and long range edge correlation in interacting
  Kitaev chains: analytic solutions and density-matrix-renormalization-group
  study

abstract:
  We study Kitaev model in one-dimension with open boundary condition by using
exact analytic methods for non-interacting system at zero chemical potential as
well as in the symmetric case of {\Delta} = t, and by using
density-matrix-renormalizationgroup method for interacting system with nearest
neighbor repulsion interaction. We suggest and examine an edge correlation
function of Majorana fermions to characterize the long range order in the
topological superconducting states and study the phase diagram of the
interating Kitaev chain.


title:
Systematic study of favored \alpha-decay half-lives of closed shell
  odd-A and doubly-odd nuclei related to ground and isomeric states

abstract:
  In this work, we systematically investigate the favored $\alpha$-decay
half-lives and $\alpha$ preformation probabilities of both odd-$A$ and
doubly-odd nuclei related to ground and isomeric states around the doubly magic
cores at $Z=82$, $N=82$ and at $Z=82$, $N=126$, respectively, within a
two-potential approach from the view of the valence nucleon (or hole). The
results show that the $\alpha$ preformation probability is linear related to
$N_\text{p}N_\text{n}$ or $N_\text{p}N_\text{n}I$, where $N_\text{p}$,
$N_\text{n}$, and $I$ are the number of valence protons (or holes), the number
of valence neutrons (or holes), and the isospin of the parent nucleus,
respectively. Fitting the $\alpha$ preformation probabilities data extracted
from the differences between experimental data and calculated half-lives
without a shell correction, we give two analytic formulas of the $\alpha$
preformation probabilities and the values of corresponding parameters. Using
those formulas and the parameters, we calculate the $\alpha$-decay half-lives
for those nuclei. The calculated results can well reproduce the experimental
data.


title:
Time scale modeling for consensus in sparse directed networks with
  time-varying topologies

abstract:
  The paper considers the consensus problem in large networks represented by
time-varying directed graphs. A practical way of dealing with large-scale
networks is to reduce their dimension by collapsing the states of nodes
belonging to densely and intensively connected clusters into aggregate
variables. It will be shown that under suitable conditions, the states of the
agents in each cluster converge fast toward a local agreement. Local agreements
correspond to aggregate variables which slowly converge to consensus. Existing
results concerning the time-scale separation in large networks focus on fixed
and undirected graphs. The aim of this work is to extend these results to the
more general case of time-varying directed topologies. It is noteworthy that in
the fixed and undirected graph case the average of the states in each cluster
is time-invariant when neglecting the interactions between clusters. Therefore,
they are good candidates for the aggregate variables. This is no longer
possible here. Instead, we find suitable time-varying weights to compute the
aggregate variables as time-invariant weighted averages of the states in each
cluster. This allows to deal with the more challenging time-varying directed
graph case. We end up with a singularly perturbed system which is analyzed by
using the tools of two time-scales averaging which seem appropriate to this
system.


title: Offline Drawing of Dynamic Trees: Algorithmics and Document Integration

abstract:
  While the algorithmic drawing of static trees is well-understood and
well-supported by software tools, creating animations depicting how a tree
changes over time is currently difficult: software support, if available at
all, is not integrated into a document production workflow and algorithmic
approaches only rarely take temporal information into consideration. During the
production of a presentation or a paper, most users will visualize how, say, a
search tree evolves over time by manually drawing a sequence of trees. We
present an extension of the popular $\TeX$ typesetting system that allows users
to specify dynamic trees inside their documents, together with a new algorithm
for drawing them. Running $\TeX$ on the documents then results in documents in
the SVG format with visually pleasing embedded animations. Our algorithm
produces animations that satisfy a set of natural aesthetic criteria when
possible. On the negative side, we show that one cannot always satisfy all
criteria simultaneously and that minimizing their violations is NP-complete.


title:
Cryptographic Enforcement of Information Flow Policies without Public
  Information via Tree Partitions

abstract:
  We may enforce an information flow policy by encrypting a protected resource
and ensuring that only users authorized by the policy are able to decrypt the
resource. In most schemes in the literature that use symmetric cryptographic
primitives, each user is assigned a single secret and derives decryption keys
using this secret and publicly available information. Recent work has
challenged this approach by developing schemes, based on a chain partition of
the information flow policy, that do not require public information for key
derivation, the trade-off being that a user may need to be assigned more than
one secret. In general, many different chain partitions exist for the same
policy and, until now, it was not known how to compute an appropriate one.
  In this paper, we introduce the notion of a tree partition, of which chain
partitions are a special case. We show how a tree partition may be used to
define a cryptographic enforcement scheme and prove that such schemes can be
instantiated in such a way as to preserve the strongest security properties
known for cryptographic enforcement schemes. We establish a number of results
linking the amount of secret material that needs to be distributed to users
with a weighted acyclic graph derived from the tree partition. These results
enable us to develop efficient algorithms for deriving tree and chain
partitions that minimize the amount of secret material that needs to be
distributed.


title:
Breakdown of local information processing may underlie isoflurane
  anesthesia effects

abstract:
  The disruption of coupling between brain areas has been suggested as the
mechanism underlying loss of consciousness in anesthesia. This hypothesis has
been tested previously by measuring the information transfer between brain
areas, and by taking reduced information transfer as a proxy for decoupling.
Yet, information transfer is a function of the amount of information available
in the information source-such that transfer decreases even for unchanged
coupling when less source information is available. Therefore, we asked whether
impaired local information processing leads to a loss of information transfer.
An important prediction of this alternative hypothesis is that changes in
locally available information (signal entropy) should be at least as pronounced
as changes in information transfer. We tested this prediction by recording
local field potentials in two ferrets after administration of isoflurane in
concentrations of 0.0 %, 0.5 %, and 1.0 %.
  We found strong decreases in the source entropy under isoflurane in area V1
and the prefrontal cortex (PFC)-as predicted by our alternative hypothesis. The
decrease in source entropy was stronger in PFC. Information transfer between V1
and PFC was reduced bidirectionally, but with a stronger decrease from PFC to
V1. This links the stronger decrease in information transfer to the stronger
decrease in source entropy, suggesting reduced source entropy reduces
information transfer. This conclusion fits the observation that the synaptic
targets of isoflurane are located in local cortical circuits rather than on the
synapses formed by interareal axonal projections. Thus, changes in information
transfer under isoflurane seem to be a consequence of changes in local
processing more than of decoupling between brain areas. We suggest that source
entropy changes must be considered whenever interpreting changes in information
transfer as decoupling.


title: Generalized Thom spectra and their topological Hochschild homology

abstract:
  We develop a theory of R-module Thom spectra for a commutative symmetric ring
spectrum R and we analyze their multiplicative properties. As an interesting
source of examples, we show that R-algebra Thom spectra associated to the
special unitary groups can be described in terms of quotient constructions on
R. We apply the general theory to obtain a description of the R-based
topological Hochschild homology associated to an R-algebra Thom spectrum.


title:
Optical quantification of harmonic acoustic radiation force excitation
  in a tissue-mimicking phantom

abstract:
  Optical tracking was used to characterize acoustic radiation force (ARF)
induced displacements in a tissue-mimicking phantom. Amplitude modulated (AM)
3.3 MHz ultrasound was used to induce ARF in the phantom which was embedded
with 10 {\mu}m microspheres that were tracked using a microscope objective and
high speed camera. For sine and square AM the harmonic components of the
fundamental and second and third harmonic frequencies were measured. The
displacement amplitudes were found to increase linearly with ARF up to 10
{\mu}m with sine modulation having 19.5% lower peak-to-peak amplitude values
than square modulation. Square modulation produced almost no second harmonic
but energy was present in the third harmonic. For the sine modulation energy
was present in the second harmonic and low energy in the third harmonic. A
finite element model was used to simulate the deformation and was both
qualitatively and quantitatively in agreement with the measurements.


title:
Absence of solid angle deficit singularities in beyond-generalized Proca
  theories

abstract:
  In Gleyzes-Langlois-Piazza-Vernizzi (GLPV) scalar-tensor theories, which are
outside the domain of second-order Horndeski theories, it is known that there
exists a solid angle deficit singularity in the case where the parameter
$\alpha_{\rm H}$ characterizing the deviation from Horndeski theories
approaches a non-vanishing constant at the center of a spherically symmetric
body. Meanwhile, it was recently shown that second-order generalized Proca
theories with a massive vector field $A^{\mu}$ can be consistently extended to
beyond-generalized Proca theories, which recover shift-symmetric GLPV theories
in the scalar limit $A^{\mu} \to \nabla^{\mu} \chi$. In beyond-generalized
Proca theories up to quartic-order Lagrangians, we show that solid angle
deficit singularities are generally absent due to the existence of a temporal
vector component. We also derive the vector-field profiles around a compact
object and show that the success of the Vainshtein mechanism operated by vector
Galileons is not prevented by new interactions in beyond generalized Proca
theories.


title: Biharmonic functions on the classical compact simple Lie groups

abstract:
  The main aim of this work is to construct several new families of proper
biharmonic functions defined on open subsets of the classical compact simple
Lie groups $\SU n$, $\SO n$ and $\Sp n$. We work in a geometric setting which
connects our study with the theory of submersive harmonic morphisms. We develop
a general duality principle and use this to interpret our new examples on the
Euclidean sphere $\s ^3$ and on the hyperbolic space $\H^3$.


title:
New Teff and [Fe/H] spectroscopic calibration for FGK dwarfs and GK
  giants

abstract:
  The ever-growing number of large spectroscopic survey programs has increased
the importance of fast and reliable methods with which to determine precise
stellar parameters. Some of these methods are highly dependent on correct
spectroscopic calibrations. The goal of this work is to obtain a new
spectroscopic calibration for a fast estimate of Teff and [Fe/H] for a wide
range of stellar spectral types. We used spectra from a joint sample of 708
stars, compiled from 451 FGK dwarfs and 257 GK-giant stars. We used
homogeneously determined spectroscopic stellar parameters to derive temperature
calibrations using a set of selected EW line-ratios, and [Fe/H] calibrations
using a set of selected FeI lines. We have derived 322 EW line-ratios and 100
FeI lines that can be used to compute Teff and [Fe/H], respectively. We show
that these calibrations are effective for FGK dwarfs and GK-giant stars in the
following ranges: 4500 K < Teff < 6500 K , 2.5 < logg < 4.9 dex, and -0.8 <
[Fe/H] < 0.5 dex. The new calibration has a standard deviation of 74 K for Teff
and 0.07 dex for [Fe/H]. We use four independent samples of stars to test and
verify the new calibration, a sample of 56 giant stars, a sample composed of
Gaia FGK benchmark stars, a sample of 36 GK-giant stars of the DR1 of the
Gaia-ESO survey, and a sample of 582 FGK-dwarf stars. We also provide a new
computer code, GeTCal, for automatically producing new calibration files based
on any new sample of stars.


title:
Quantum-statistical approach to electromagnetic wave propagation and
  dissipation inside dielectric media and nanophotonic and plasmonic waveguides

abstract:
  Quantum-statistical effects occur during the propagation of electromagnetic
(EM) waves inside the dielectric media or metamaterials, which include a large
class of nanophotonic and plasmonic waveguides with dissipation and noise.
Exploiting the formal analogy between the Schrodinger equation and the Maxwell
equations for dielectric linear media, we rigorously derive the effective
Hamiltonian operator which describes such propagation. This operator turns out
to be essentially non-Hermitian in general, and pseudo-Hermitian in some
special cases. Using the density operator approach for general non-Hermitian
Hamiltonians, we derive a master equation that describes the statistical
ensembles of EM wave modes. The method also describes the quantum dissipative
and decoherence processes which happen during the wave's propagation, and,
among other things, it reveals the conditions that are necessary to control the
energy and information loss inside the above-mentioned materials.


title:
Universal Scaling of Pair-Excess Entropy and Diffusion in Strongly
  Coupled Liquids

abstract:
  Understanding diffusion in liquids from properties of static structure is a
long standing problem in condensed matter theory. Here we report an atomistic
study of excess entropy and diffusion coefficient in a strongly coupled Yukawa
liquid. We observe that the pair excess entropy $s_2$ scales with temperature
as $-3.285 \;(T_m / T)^{0.665}$ and contributes to about $90\%$ of the total
excess entropy close to the freezing transition $T_m$. We further report that
at low temperatures where the diffusive transport is mediated by cage
relaxation, the diffusion coefficient when expressed in natural units of the
Enskog collision frequency and the effective hard sphere diameter, obeys the
scaling law $0.04\; e^{s_2}$ and deviates from it at high enough temperatures
where cages cannot form. The scaling laws reported here may also apply to
strongly coupled dusty plasmas and charged colloids.


title: Motion Representation with Acceleration Images

abstract:
  Information of time differentiation is extremely important cue for a motion
representation. We have applied first-order differential velocity from a
positional information, moreover we believe that second-order differential
acceleration is also a significant feature in a motion representation. However,
an acceleration image based on a typical optical flow includes motion noises.
We have not employed the acceleration image because the noises are too strong
to catch an effective motion feature in an image sequence. On one hand, the
recent convolutional neural networks (CNN) are robust against input noises. In
this paper, we employ acceleration-stream in addition to the spatial- and
temporal-stream based on the two-stream CNN. We clearly show the effectiveness
of adding the acceleration stream to the two-stream CNN.


title:
An algorithm to estimate the vertices of a tetrahedron from uniform
  random points inside

abstract:
  In this paper, we give an algorithm to infer the positions of the vertices of
an unknown tetrahedron, given a sample of points which are uniformly
distributed within the tetrahedron. The accuracy of the algorithm is
demonstrated using some numerical experiments.


title: USBee: Air-Gap Covert-Channel via Electromagnetic Emission from USB

abstract:
  In recent years researchers have demonstrated how attackers could use USB
connectors implanted with RF transmitters to exfiltrate data from secure, and
even air-gapped, computers (e.g., COTTONMOUTH in the leaked NSA ANT catalog).
Such methods require a hardware modification of the USB plug or device, in
which a dedicated RF transmitter is embedded. In this paper we present USBee, a
software that can utilize an unmodified USB device connected to a computer as a
RF transmitter. We demonstrate how a software can intentionally generate
controlled electromagnetic emissions from the data bus of a USB connector. We
also show that the emitted RF signals can be controlled and modulated with
arbitrary binary data. We implement a prototype of USBee, and discuss its
design and implementation details including signal generation and modulation.
We evaluate the transmitter by building a receiver and demodulator using GNU
Radio. Our evaluation shows that USBee can be used for transmitting binary data
to a nearby receiver at a bandwidth of 20 to 80 BPS (bytes per second).


title:
CNO abundances and carbon isotope ratios in evolved stars of the open
  clusters NGC 2324, NGC 2477, and NGC 3960

abstract:
  Our main aim is to determine carbon-to-nitrogen and carbon isotope ratios for
evolved giants in the open clusters NGC 2324, NGC 2477, and NGC 3960, which
have turn-off masses of about 2 Msun, and to compare them with predictions of
theoretical models. High-resolution spectra were analysed using a differential
synthetic spectrum method. Abundances of carbon were derived using the C2 Swan
(0,1) band heads at 5135 and 5635.5 A. The wavelength interval 7940-8130 A with
strong CN features was analysed to determine nitrogen abundances and carbon
isotope ratios. The oxygen abundances were determined from the [Oi] line at
6300 A. The mean values of the CNO abundances are [C/Fe]=-0.35+-0.06 (s.d.),
[N/Fe]=0.28+-0.05, and [O/Fe]=-0.02+-0.10 in seven stars of NGC 2324;
[C/Fe]=-0.26+-0.02, [N/Fe]=0.39+-0.04, and [O/Fe]=-0.11+-0.06 in six stars of
NGC 2477; and [C/Fe]=-0.39+-0.04, [N/Fe]=0.32+-0.05, and [O/Fe]=-0.19+-0.06 in
six stars of NGC 3960. The mean C/N ratio is equal to 0.92+-0.12, 0.91+-0.09,
and 0.80+-0.13, respectively. The mean 12C/13C ratio is equal to 21+-1, 20+-1,
and 16+-4, respectively. The 12C/13C and C/N ratios of stars in the
investigated open clusters were compared with the ratios predicted by stellar
evolution models. The mean values of the 12C/13C and C/N ratios in NGC 2324 and
NGC 2477 agree well with the first dredge-up and thermohaline-induced
extra-mixing models, which are similar for intermediate turn-off mass stars.
The 12C/13C ratios in the investigated clump stars of NGC 3960 span from 10 to
20. The mean carbon isotope and C/N ratios in NGC 3960 are close to predictions
of the model in which the thermohaline- and rotation-induced (if rotation
velocity at the zero-age main sequence was 30% of the critical velocity)
extra-mixing act together.


title: Fusion systems over a Sylow $p$-subgroup of $\mathrm{G}_2(p)$

abstract:
  For $S$ a Sylow $p$-subgroup of the group $\mathrm{G}_2(p)$ for $p$ odd, up
to isomorphism of fusion systems, we determine all saturated fusion systems
$\mathcal{F}$ on $S$ with $O_p(\mathcal{F})=1$. For $p \ne 7$, all such fusion
systems are realized by finite groups whereas for $p=7$ there are $29$
saturated fusion systems of which $27$ are exotic.


title:
The inheritance of nondegenerate multistationarity in chemical reaction
  networks

abstract:
  We study how the properties of allowing multiple positive nondegenerate
equilibria (MPNE) and multiple positive linearly stable equilibria (MPSE) are
inherited in chemical reaction networks (CRNs). Specifically, when is it that
we can deduce that a CRN admits MPNE or MPSE based on analysis of its
subnetworks? Using basic techniques from analysis we are able to identify a
number of situations where MPNE and MPSE are inherited as we build up a
network. Some of these modifications are known while others are new, but all
results are proved using the same basic framework, which we believe will yield
further results. The results are presented primarily for mass action kinetics,
although with natural, and in some cases immediate, generalisation to other
classes of kinetics.


title: Non-vacuum AdS cosmology and comments on gauge theory correlator

abstract:
  Several time dependent backgrounds, with perfect fluid matter, can be used to
construct solutions of Einstein equations in the presence of a negative
cosmological constant along with some matter sources. In this work we focus on
the non-vacuum Kasner-AdS geometry and its solitonic generalization. To
characterize these space-times, we provide ways to embed them in higher
dimensional flat space-times. General space-like geodesics are then studied and
used to compute the two point boundary correlators within the geodesic
approximation.


title:
Controlling Feynman diagrammatic expansions: physical nature of the
  pseudo gap in the two-dimensional Hubbard model

abstract:
  We introduce a method for summing Feynman's perturbation series based on
diagrammatic Monte Carlo that significantly improves its convergence
properties. This allows us to investigate in a controllable manner the
pseudogap regime of the Hubbard model and to study the nodal/antinodal
dichotomy at low doping and intermediate coupling. Marked differences from the
weak coupling scenario are manifest, such as a higher degree of incoherence at
the antinodes than at the `hot spots'. Our results show that the pseudogap and
reduction of quasiparticle coherence at the antinode is due to
antiferromagnetic spin correlations centered around the commensurate
$(\pi,\pi)$ wavevector. In contrast, the dominant source of scattering at the
node is associated with incommensurate momentum transfer. Umklapp scattering is
found to play a key role in the nodal/antinodal dichotomy.


title:
Thermal entanglement properties of N-qubit quantum Heisenberg chain in a
  two-component magnetic field

abstract:
  We elucidate the finite temperature entanglement properties of $N=9$ qubits
Heisenberg $XX$ and $XXZ$ models under the presence of a polarized magnetic
field in $xz$ plane by means of concurrence concept. We perform a systematic
analysis for a wide range of the system parameters. Our results suggest that
the global phase regions which separate the entangled and non-entangled regions
sensitively depend upon the spin-spin interaction term of the $z-$ component of
two neighboring spins $J_{z}/J_{x}$, temperature as well as polarized magnetic
field components. Thereby, we think that polarized magnetic field can be used a
control parameter to determine the amount of thermal entanglement between pair
of qubits for different temperatures and spin-spin interaction terms. Moreover,
it has been found that the nearest-neighbor pair of qubits does not point out a
re-entrant type entanglement character when one only deals with the
nearest-neighbor pair of qubits. However, as one considers next-nearest
neighbor pair of qubits, it is possible to see the evidences of re-entrant type
entanglement behaviors.


title:
The extended High A(V) Quasar Survey: Searching for dusty absorbers
  toward mid-infrared selected quasars

abstract:
  We present the results of a new spectroscopic survey for dusty intervening
absorption systems, particularly damped Ly$\alpha$ absorbers (DLAs), towards
reddened quasars. The candidate quasars are selected from mid-infrared
photometry from the Wide-field Infrared Survey Explorer combined with optical
and near-infrared photometry. Out of 1073 candidates, we secure low-resolution
spectra for 108 using the Nordic Optical Telescope on La Palma, Spain. Based on
the spectra, we are able to classify 100 of the 108 targets as quasars. A large
fraction (50 %) is observed to have broad absorption lines (BALs). Moreover, we
find 6 quasars with strange breaks in their spectra, which are not consistent
with regular dust reddening. Using template fitting we infer the amount of
reddening along each line of sight ranging from A(V)$\approx$0.1 mag to 1.2 mag
(assuming an SMC extinction curve). In four cases, the reddening is consistent
with dust exhibiting the 2175{\AA} feature caused by an intervening absorber,
and for two of these, a MgII absorption system is observed at the best-fit
absorption redshift. In the rest of the cases, the reddening is most likely
intrinsic to the quasar. We observe no evidence for dusty DLAs in this survey.
However, the large fraction of BAL quasars hampers the detection of absorption
systems. Out of the 50 non-BAL quasars only 28 have sufficiently high redshift
to detect Ly$\alpha$ in absorption.


title: Alpha-decay energies of superheavy nuclei for the Fayans functional

abstract:
  Alpha-decay energies for several chains of super-heavy nuclei are calculated
within the self-consistent mean-field approach by using the Fayans functional
FaNDF$^0$. They are compared to the experimental data and predictions of two
Skyrme functionals, SLy4 and SkM*, and of the macro-micro method as well. The
corresponding lifetimes are calculated with the use of the
semi-phenomenological formulas by Parkhomenko and Sobiczewski and by Royer and
Zhang.


title: Masses and decay widths of radially excited Bottom mesons

abstract:
  Inspired from the experimental information coming from LHC [2,3] and Babar
[4] for radially higher excited charmed mesons, we predict the masses and
decays of the n=2 S-wave and P- wave bottom mesons using the effective
lagrangian approach. Using heavy quark effective theory approach,
non-perturbative parameters (?, ?1 and ?2) are fitted using the available
experimental and theoretical informations on charm masses. Using heavy quark
symmetry and the values of these fitted parameters, the masses of radially
excited even and odd parity bottom mesons with and without strangness are
predicted. These predicted masses led in constraining the decay widths of these
12 states, and also shed light on the unknown values of the higher hadronic
coupling constants eeg 2 SH and eeg 2 TH. Studying the properties like masses,
decays of 2S and 2P states and some hadronic couplings would help forthcoming
experiments to look into these states in future.


title: Erdmessung mit Quanten und Relativit\"at

abstract:
  Recent developments in fundamental physics (in theory as well as in
technology) provide novel capabilities for geodetic applications such as
refined observations of the Earth`s gravity field. We will focus on two new
concepts: one applies atomic interferometry for (satellite) gravimetry, the
other uses clock measurements for observing potential values. In the first
case, gravity anomalies are determined by observing free-falling atoms (quantum
gravimetry), such technique can also be applied for future gradiometric
measurements in space. In the second case according to Einstein`s theory of
general relativity, frequency comparisons of highly precise optical clocks give
access to differences of the gravity potential, even over long distances
(relativistic geodesy). Also laser interferometry between test masses in space
with nanometer accuracy belongs to these novel concepts. For the latter,
technology developed for gravitational wave detection and successfully tested
in the LISA/pathfinder mission is being prepared for geodetic measurements.
Those concepts are recently elaborated in close cooperation between physicists
and geodesists at the University of Hannover under the umbrella of the
Collaborative Research Center SFB 1128 Relativistic geodesy and gravimetry with
quantum sensors (geo-Q). We will give a few examples where geodesy will
potentially benefit from these novel developments and show future perspectives.


title: Arnold diffusion for a complete family of perturbations

abstract:
  In this work we illustrate the Arnold diffusion in a concrete example---the
\emph{a priori} unstable Hamiltonian system of $2+1/2$ degrees of freedom
$H(p,q,I,\varphi,s) = p^{2}/2+\cos q -1 +I^{2}/2 +
h(q,\varphi,s;\varepsilon)$---proving that for \emph{any} small periodic
perturbation of the form $h(q,\varphi,s;\varepsilon) = \varepsilon\cos q\left(
a_{00} + a_{10}\cos\varphi + a_{01}\cos s \right)$ ($a_{10}a_{01} \neq 0$)
there is global instability for the action. For the proof we apply a
geometrical mechanism based in the so-called Scattering map.
  This work has the following structure: In a first stage, for a more
restricted case ($I^*\thicksim\pi/2\mu$, $\mu = a_{10}/a_{01}$), we use only
one scattering map, with a special property: the existence of simple paths of
diffusion called highways. Later, in the general case we combine a scattering
map with the inner map (inner dynamics) to prove the more general result (the
existence of the instability for any $\mu$). The bifurcations of the scattering
map are also studied as a function of $\mu$. Finally, we give an estimate for
the time of diffusion, and we show that this time is primarily the time spent
under the scattering map.


title: Renormalisation Group Corrections to Neutrino Mixing Sum Rules

abstract:
  Neutrino mixing sum rules are common to a large class of models based on the
(discrete) symmetry approach to lepton flavour. In this approach the neutrino
mixing matrix $U$ is assumed to have an underlying approximate symmetry form
$\tilde{U}_{\nu}$, which is dictated by, or associated with, the employed
(discrete) symmetry. In such a setup the cosine of the Dirac CP-violating phase
$\delta$ can be related to the three neutrino mixing angles in terms of a sum
rule which depends on the symmetry form of $\tilde{U}_{\nu}$. We consider five
extensively discussed possible symmetry forms of $\tilde{U}_{\nu}$: i)
bimaximal (BM) and ii) tri-bimaximal (TBM) forms, the forms corresponding to
iii) golden ratio type A (GRA) mixing, iv) golden ratio type B (GRB) mixing,
and v) hexagonal (HG) mixing. For each of these forms we investigate the
renormalisation group corrections to the sum rule predictions for $\delta$ in
the cases of neutrino Majorana mass term generated by the Weinberg (dimension
5) operator added to i) the Standard Model, and ii) the minimal SUSY extension
of the Standard Model.


title:
Generalized Parton Distributions: confining potential effects within
  AdS/QCD

abstract:
  Generalized Parton Distributions are investigated within a holographic
approach where the string modes in the fifth dimension describe the nucleon in
a bottom-up or AdS/QCD framework. The aim is to bring the AdS/QCD results in
the realm of phenomenology in order to extract consequences and previsions. Two
main aspects are studied: i) the role of the confining potential needed for
breaking conformal invariance and introducing confinement (both: classic
Soft-Wall and recent Infra-Red potentials are investigated); ii) the extension
of the predicted GPDs to the entire range of off-forward kinematics by means of
Double-Distributions. Higher Fock states are included describing the nucleon as
a superposition of three valence quarks and quark-antiquark pairs and gluons.


title:
From resonantly interacting fermions with effective range to neutron
  matter

abstract:
  A density functional theory is proposed for strongly interacting fermions
with arbitrary large negative scattering length. The functional has only two
parameters that are directly fixed to reproduce the universal properties of
unitary gas: the so-called "Bertsch parameter" $\xi_0$ and a parameter $\eta_e$
related to the possible influence of the effective range $r_e$ at infinite
scattering length $a$. Using most recent quantum Monte-Carlo (QMC) estimates of
these two parameters, it is shown that the functional properly reproduces the
experimental measurements of interacting Fermi systems not only at unitarity
but also away from this limit over a wide range of $(ak_F)^{-1}$ values. The
functional is applied to obtain an expression of the Tan's contact parameter
including the effect of $r_e$. Application is finally made to neutron matter.
It is shown that most recent QMC results are well reproduced.


title: A note on how the problem of Partion of Integers show in Caching

abstract:
  In this article, we show how the finding the number of partitions of same
size of a positive integer show up in caching networks. We present a stochastic
model for caching where user requests (represented with positive integers) are
a random process with uniform distribution and the sum of user requests plays
an important role to tell us about the nature of the caching process. We
discuss Euler's generating function to compute the number of partitions of a
positive integer of same size. Also, we derive a simple approximation for
guessing the guessing the number of partitions of same size and discuss some
special sequences. Lastly, we present a simple algorithm to enumerate all the
partitions of a positive integer of same size.


title: Asymptotically optimal pilot allocation over Markovian fading channels

abstract:
  We investigate a pilot allocation problem in wireless networks over Markovian
fading channels. In wireless systems, the Channel State Information (CSI) is
collected at the Base Station (BS), in particular, this paper considers a
pilot-aided channel estimation method (TDD mode). Typically, there are less
available pilots than users, hence at each slot the scheduler needs to decide
an allocation of pilots to users with the goal of maximizing the long-term
average throughput. There is an inherent tradeoff in how the limited pilots are
used: assign a pilot to a user with up-to-date CSI and good channel condition
for exploitation, or assign a pilot to a user with outdated CSI for
exploration. As we show, the arising pilot allocation problem is a restless
bandit problem and thus its optimal solution is out of reach. In this paper, we
propose an approximation that, through the Lagrangian relaxation approach,
provides a low-complexity heuristic, the Whittle index policy. We prove this
policy to be asymptotically optimal in the many users regime (when the number
of users in the system and the available pilots for channel sensing grow
large). We evaluate the performance of Whittle's index policy in various
scenarios and illustrate its remarkably good performance.


title:
Identification of milestone papers through time-balanced network
  centrality

abstract:
  Citations between scientific papers and related bibliometric indices, such as
the $h$-index for authors and the impact factor for journals, are being
increasingly used - often in controversial ways - as quantitative tools for
research evaluation. Yet, a fundamental research question remains still open:
to which extent do quantitative metrics capture the significance of scientific
works? We analyze the network of citations among the $449,935$ papers published
by the American Physical Society (APS) journals between 1893 and 2009, and
focus on the comparison of metrics built on the citation count with
network-based metrics. We contrast five article-level metrics with respect to
the rankings that they assign to a set of fundamental papers, called Milestone
Letters, carefully selected by the APS editors for "making long-lived
contributions to physics, either by announcing significant discoveries, or by
initiating new areas of research". A new metric, which combines PageRank
centrality with the explicit requirement that paper score is not biased by
paper age, is the best-performing metric overall in identifying the Milestone
Letters. The lack of time bias in the new metric makes it also possible to use
it to compare papers of different age on the same scale. We find that
network-based metrics identify the Milestone Letters better than metrics based
on the citation count, which suggests that the structure of the citation
network contains information that can be used to improve the ranking of
scientific publications. The methods and results presented here are relevant
for all evolving systems where network centrality metrics are applied, for
example the World Wide Web and online social networks. An interactive Web
platform where it is possible to view the ranking of the APS papers by rescaled
PageRank is available at the address \url{http://www.sciencenow.info}.


title: Approximations to the exact exchange potential: KLI versus semilocal

abstract:
  In the search for an accurate and computationally efficient approximation to
the exact exchange potential of Kohn-Sham density functional theory, we
recently compared various semilocal exchange potentials to the exact one [F.
Tran et al., Phys. Rev. B 91, 165121 (2015)]. It was concluded that the
Becke-Johnson (BJ) potential is a very good starting point, but requires the
use of empirical parameters to obtain good agreement with the exact exchange
potential. In the present work, we extend the comparison by considering the
Krieger-Li-Iafrate (KLI) approximation, which is a beyond-semilocal
approximation. It is shown that overall the KLI and BJ-based potentials are the
most reliable approximations to the exact exchange potential, however, sizeable
differences, especially for the antiferromagnetic transition-metal oxides, can
be obtained.


title:
Least-squares spectral element preconditioners for fourth order elliptic
  problems

abstract:
  The goal of this paper is to propose preconditioners for the system of linear
equations that arises from a discretization of fourth order elliptic problems
using spectral element methods. These preconditioners are constructed using
separation of variables and can be diagonalized and hence easy to invert. For
second order elliptic problems this technique has proven to be very successful
and performs better than other preconditioners. We show that these
preconditioners are spectrally equivalent to the quadratic forms by which we
approximate them. Numerical result for the biharmonic problem are presented to
validate the theoretical estimates.


title:
Hydrodynamic VS collisionless dynamics of a 1D harmonically trapped Bose
  gas

abstract:
  By using a sum rule approach we investigate the transition between the
hydrodynamic and the collisionless regime of the collective modes in a 1D
harmonically trapped Bose gas. Both the weakly interacting gas and the
Tonks-Girardeau limits are considered. We predict that the excitation of the
dipole compression mode is characterized, in the high temperature collisionless
regime, by a beating signal of two different frequencies ($\omega_z$ and
$3\omega_z$) while, in the high temperature collisional regime, the excitation
consists of a single frequency ($\sqrt{7}\omega_z$). This behaviour differs
from the case of the lowest breathing mode whose excitation consists of a
single frequency ($2\omega_z$) in both regimes. Our predictions for the dipole
compression mode open promising perspectives for the experimental investigation
of collisional effects in 1D configurations.


title: 1-Bend RAC Drawings of 1-Planar Graphs

abstract:
  A graph is 1-planar if it has a drawing where each edge is crossed at most
once. A drawing is RAC (Right Angle Crossing) if the edges cross only at right
angles. The relationships between 1-planar graphs and RAC drawings have been
partially studied in the literature. It is known that there are both 1-planar
graphs that are not straight-line RAC drawable and graphs that have a
straight-line RAC drawing but that are not 1-planar. Also, straight-line RAC
drawings always exist for IC-planar graphs, a subclass of 1-planar graphs. One
of the main questions still open is whether every 1-planar graph has a RAC
drawing with at most one bend per edge. We positively answer this question.


title:
Heritage of Konkoly's Solar Observations: the Debrecen Photoheliograph
  Programme and the Debrecen Sunspot Databases

abstract:
  The primary task of the Debrecen Heliophysical Observatory (DHO) was to
produce the detailed and reliable photographic documentation of the solar
photospheric activity since 1958. This long-term effort resulted in various
solar catalogues based on ground-based and space-borne observations. The DHO
hosts solar-image databases containing heritages of two former Hungarian
observatories. One of the sets of drawings was observed between 1872 and 1891
at the \'Ogyalla Observatory (now Hurbanovo, Slovakia) founded by Mikl\'os
Konkoly-Thege (1842-1916). We briefly summarize the history of the events that
resulted in the longest photographic sunspot database available at the DHO at
present, and we show the basic role of Dr. Mikl\'os Konkoly-Thege in this
achievement.


title: Floquet analysis of a quantum system with modulated periodic driving

abstract:
  We consider a quantum system periodically driven with a strength which varies
slowly on the scale of the driving period. The analysis is based on a general
formulation of the Floquet theory relying on the extended Hilbert space. It is
shown that the dynamics of the system can be described in terms of a slowly
varying effective Floquet Hamiltonian that captures the long-term evolution, as
well as rapidly oscillating micromotion operators. We obtain a systematic
high-frequency expansion of all these operators. Generalizing the previous
studies, the expanded effective Hamiltonian is now time-dependent and contains
extra terms appearing due to changes in the periodic driving. The same applies
to the micromotion operators which exhibit a slow temporal dependence in
addition to the rapid oscillations. As an illustration, we consider a
quantum-mechanical spin in an oscillating magnetic field with a slowly changing
direction. The effective evolution of the spin is then associated with
non-Abelian geometric phases reflecting the geometry of the extended Floquet
space. The developed formalism is general and also applies to other
periodically driven systems, such as shaken optical lattices with a
time-dependent shaking strength, a situation relevant to the cold atom
experiments.

categories: cond-mat.quant-gas math-ph math.MP physics.atom-ph quant-ph


title: Pure patterns of order 2

abstract:
  We provide mutual elementary recursive order isomorphisms between classical
ordinal notations, based on Skolem hulling, and notations from pure elementary
patterns of resemblance of order $2$, showing that the latter characterize the
proof-theoretic ordinal of the fragment $\Pi^1_1$-$\mathrm{CA}_0$ of second
order number theory, or equivalently the set theory $\mathrm{KPl}_0$. As a
corollary, we prove that Carlson's result on the well-quasi orderedness of
respecting forests of order $2$ implies transfinite induction up to the ordinal
of $\mathrm{KPl}_0$. We expect that our approach will facilitate analysis of
more powerful systems of patterns.


title:
Optimal Control for a Class of Infinite Dimensional Systems Involving an
  $L^\infty$-term in the Cost Functional

abstract:
  An optimal control problem with a time-parameter is considered. The
functional to be optimized includes the maximum over time-horizon reached by a
function of the state variable, and so an $L^\infty$-term. In addition to the
classical control function, the time at which this maximum is reached is
considered as a free parameter. The problem couples the behavior of the state
and the control, with this time-parameter. A change of variable is introduced
to derive first and second-order optimality conditions. This allows the
implementation of a Newton method. Numerical simulations are developed, for
selected ordinary differential equations and a partial differential equation,
which illustrate the influence of the additional parameter and the original
motivation.


title: Potentials of a Frobenius like structure and $m$ bases of a vector space

abstract:
  This paper proves the existence of potentials of the first and second kind of
a Frobenius like structure in a frame which encompasses families of
arrangements.
  Surprisingly the proof is based on the study of finite sets of vectors in a
finite-dimensional vector space $V$. Given a natural number $m$ and a finite
set $(v_i)$ of vectors we give a necessary and sufficient condition to find in
the set $(v_i)$ $m$ bases of $V$. If $m$ bases in $(v_i)$ can be selected, we
define elementary transformations of such a selection and show that any two
selections are connected by a sequence of elementary transformations.


title:
High degree vertices in the Power of Choice model combined with
  Preferential Attachment

abstract:
  We find assimpotics for the first $k$ highest degrees of the degree
distribution in an evolving tree model combining the local choice and the
preferential attachment. In the considered model, the random graph is
constructd in the following way. At each step, a new vertex is introduced.
Then, we connect it with one (the vertex with the largest degree is chosen) of
$d$ ($d>2$) possible neighbors, which are sampled from the set of the existing
vertices with the probability proportional to their degrees. It is known that
the maximum of the degree distribution in this model has linear behavior. We
prove that $k$-th highest dergee has a sublinear behavior with a power depends
on $d$. This contrasts sharply with what is seen in the preferential attachment
model without choice, where all highest degrees in the degree distribution has
the same sublinear order. The proof is based on showing that the considered
tree has a persistent hub by comparison with the standard preferential
attachment model, along with martingale arguments.


title: 1-bend Upward Planar Drawings of SP-digraphs

abstract:
  It is proved that every series-parallel digraph whose maximum vertex-degree
is $\Delta$ admits an upward planar drawing with at most one bend per edge such
that each edge segment has one of $\Delta$ distinct slopes. This is shown to be
worst-case optimal in terms of the number of slopes. Furthermore, our
construction gives rise to drawings with optimal angular resolution
$\frac{\pi}{\Delta}$. A variant of the proof technique is used to show that
(non-directed) reduced series-parallel graphs and flat series-parallel graphs
have a (non-upward) one-bend planar drawing with $\lceil\frac{\Delta}{2}\rceil$
distinct slopes if biconnected, and with $\lceil\frac{\Delta}{2}\rceil+1$
distinct slopes if connected.


title:
Level sets of asymptotic mean of digits function for 4-adic
  representation of real number

abstract:
  We study topological, metric and fractal properties of the level sets
$$S_{\theta}=\{x:r(x)=\theta\}$$ of the function $r$ of asymptotic mean of
digits of a number $x\in[0;1]$ in its $4$-adic representation,
$$r(x)=\lim\limits_{n\to\infty}\frac{1}{n}\sum\limits^{n}_{i=1}\alpha_i(x)$$ if
the asymptotic frequency $\nu_j(x)$ of at least one digit does not exist, were
$$ \nu_j(x)=\lim_{n\to\infty}n^{-1}#\{k: \alpha_k(x)=j, k\leqslant n\}, \:\:
j=0,1,2,3. $$


title: Simultaneous Orthogonal Planarity

abstract:
  We introduce and study the $\textit{OrthoSEFE}-k$ problem: Given $k$ planar
graphs each with maximum degree 4 and the same vertex set, do they admit an
OrthoSEFE, that is, is there an assignment of the vertices to grid points and
of the edges to paths on the grid such that the same edges in distinct graphs
are assigned the same path and such that the assignment induces a planar
orthogonal drawing of each of the $k$ graphs?
  We show that the problem is NP-complete for $k \geq 3$ even if the shared
graph is a Hamiltonian cycle and has sunflower intersection and for $k \geq 2$
even if the shared graph consists of a cycle and of isolated vertices. Whereas
the problem is polynomial-time solvable for $k=2$ when the union graph has
maximum degree five and the shared graph is biconnected. Further, when the
shared graph is biconnected and has sunflower intersection, we show that every
positive instance has an OrthoSEFE with at most three bends per edge.


title: Quaternionic B-Splines

abstract:
  We introduce B-splines on the line of quaternionic order $B_q$ ($q$ in the
algebra of quaternions) for the purposes of multi-channel signal and image
analysis. The functions $B_q$ are defined first by their Fourier transforms,
then as the solutions of distributional differential equation of quaternionic
order. The equivalence of these definitions requires properties of quaternionic
Gamma functions and binomial expansions, both of which we investigate. The
relationship between $B_q$ and a backwards difference operator is shown,
leading to a recurrence formula. We show that the collection of integer shifts
of $B_q$ is a Riesz basis for its span, hence generating a multiresolution
analysis. Finally, we demonstrate the pointwise and $L^p$ convergence of the
quaternionic B-splines to quarternionic Gaussian functions.


title:
Cram\'er-Rao bound for time-continuous measurements in linear Gaussian
  quantum systems

abstract:
  We describe a compact and reliable method to calculate the Fisher information
for the estimation of a dynamical parameter in a continuously measured linear
Gaussian quantum system. Unlike previous methods in the literature, which
involve the numerical integration of a stochastic master equation for the
corresponding density operator in a Hilbert space of infinite dimension, the
formulas here derived depends only on the evolution of first and second moments
of the quantum states, and thus can be easily evaluated without the need of any
approximation. We also present some basic but physically meaningful examples
where this result is exploited, calculating analytical and numerical bounds on
the estimation of the squeezing parameter for a quantum parametric amplifier,
and of a constant force acting on a mechanical oscillator in a standard
optomechanical scenario.


title: Free-energy functional of the Debye-H\"uckel model of simple fluids

abstract:
  The Debye-H\"uckel approximation to the free-energy of a simple fluid is
written as a functional of the pair correlation function. This functional can
be seen as the Debye-H\"uckel equivalent to the functional derived in the
hyper-netted chain framework by Morita and Hiroike, as well as by Lado. It
allows one to obtain the Debye-H\"uckel integral equation through a
minimization with respect to the pair correlation function, leads to the
correct form of the internal energy, and fulfills the virial theorem.


title:
Including van der Waals Forces in Diffusion-Convection Equations -
  Modeling, Analysis, and Numerical Simulations

abstract:
  This paper presents a model of van der Waals forces in the framework of
diffusion-convection equations. The model consists of a nonlinear and
degenerated diffusion-convection equation, which furthermore can be considered
as a model for slow perikinetic coagulation. For the analytical investigation,
we transform the model to a porous medium equation, which provides us access to
the comprehensive analytical results for porous medium equations. Additionally,
this transformation reveals a new application for porous medium equations.
Eventually, we present numerical simulations of the model by solving the porous
medium equation. We note that we solve the porous medium equation without any
further regularization, which is often applied in this context.


title:
Global regularity of two dimensional inhomogeneous incompressible
  Navier-Stokes Equations with large data

abstract:
  For two dimensional inhomogeneous Navier-Stokes of incompressible flows, with
the assumption that the viscosity depends on the density but with a positive
lower bound, using a partial regularity approach, in particular some enhanced
decay estimates, we establish the global in time regularity for large data away
from vacuum.


title: On the Erdos-Fuchs theorem

abstract: We prove several extensions of the Erdos-Fuchs theorem.


title: Multi-Class Multi-Object Tracking using Changing Point Detection

abstract:
  This paper presents a robust multi-class multi-object tracking (MCMOT)
formulated by a Bayesian filtering framework. Multi-object tracking for
unlimited object classes is conducted by combining detection responses and
changing point detection (CPD) algorithm. The CPD model is used to observe
abrupt or abnormal changes due to a drift and an occlusion based spatiotemporal
characteristics of track states. The ensemble of convolutional neural network
(CNN) based object detector and Lucas-Kanede Tracker (KLT) based motion
detector is employed to compute the likelihoods of foreground regions as the
detection responses of different object classes. Extensive experiments are
performed using lately introduced challenging benchmark videos; ImageNet VID
and MOT benchmark dataset. The comparison to state-of-the-art video tracking
techniques shows very encouraging results.


title: Multi-Label Classification Method Based on Extreme Learning Machines

abstract:
  In this paper, an Extreme Learning Machine (ELM) based technique for
Multi-label classification problems is proposed and discussed. In multi-label
classification, each of the input data samples belongs to one or more than one
class labels. The traditional binary and multi-class classification problems
are the subset of the multi-label problem with the number of labels
corresponding to each sample limited to one. The proposed ELM based multi-label
classification technique is evaluated with six different benchmark multi-label
datasets from different domains such as multimedia, text and biology. A
detailed comparison of the results is made by comparing the proposed method
with the results from nine state of the arts techniques for five different
evaluation metrics. The nine methods are chosen from different categories of
multi-label methods. The comparative results shows that the proposed Extreme
Learning Machine based multi-label classification technique is a better
alternative than the existing state of the art methods for multi-label
problems.


title: On the geometry of projective tensor products

abstract:
  In this work, we study the volume ratio of the projective tensor products
$\ell^n_p\otimes_{\pi}\ell_q^n\otimes_{\pi}\ell_r^n$ with $1\leq p\leq q \leq r
\leq \infty$. We obtain asymptotic formulas that are sharp in almost all cases.
As a consequence of our estimates, these spaces allow for a nearly Euclidean
decomposition of Kashin type whenever $1\leq p \leq q\leq r \leq 2$ or $1\leq p
\leq 2 \leq r \leq \infty$ and $q=2$. Also, from the Bourgain-Milman bound on
the volume ratio of Banach spaces in terms of their cotype $2$ constant, we
obtain information on the cotype of these $3$-fold projective tensor products.
Our results naturally generalize to $k$-fold products
$\ell_{p_1}^n\otimes_{\pi}\dots \otimes_{\pi}\ell_{p_k}^n$ with $k\in\mathbb N$
and $1\leq p_1 \leq \dots\leq p_k \leq \infty$.


title: Experimental evidence of the Frenkel line in supercritical neon

abstract:
  Recent research suggests that the supercritical state consists of liquidlike
and gaslike states where particle dynamics and key system properties are
qualitatively different. We report experimental evidence of the structural
crossover in supercritical neon at pressure and temperature conditions
significantly exceeding the critical point values: 250$\,P_c$ and 6.6$\,T_c$.
The experimental results show a crossover of the medium-range order structure
evidenced by the change of the structure factor with pressure. We also observe
the crossover of the short-range order structure indicated by changes in the
coordination number. The relative width of the crossover is fairly narrow and
is smaller than 10-12 \% in pressure and temperature. By comparing our
experimental results with molecular dynamics simulations, we suggest that the
observed crossover can be attributed to the Frenkel line and discuss the
relationship between the structural crossover and qualitative changes of
dynamical and thermodynamic properties of supercritical matter.


title: Revisiting virtual difference ideals

abstract:
  The main idea of [4] was that structures built from periodic prime ideals
have better properties from the usual ones built from invariant ideals; but
unable to work with periodic ideals alone, we had to generalise further to a
somewhat ephemeral setting called virtual ideals. This text has two purposes.
It corrects an error in [4] discovered by Tom Scanlon's UCB seminar, recovering
all results for all virtual ideals. In addition, based on results in [3], we
describe a wide family of difference equations where virtual ideals reduce to
periodic ideals.


title:
Dipolar dissociation dynamics in electron collisions with oxygen
  molecules

abstract:
  The dipolar dissociation of molecular oxygen due to 21-35 eV energy electron
collision has been studied using the time sliced velocity map imaging
technique. A rough estimation about the threshold of the process and the
kinetic energy and angular distribution of the fragment negative ions are
measured. The dipolar dissociation found to be occur due to pre-dissociation of
a Rydberg state via ion-pair state for lower incident electron energies as well
from also direct excitation to the ion-pair states for relatively higher
primary beam energy. The location and symmetry of the excited states were
determined from the kinetic energy and angular distribution data respectively.


title: Optical polarization of high-energy BL Lac objects

abstract:
  We investigate the optical polarization properties of high-energy BL Lac
objects using data from the RoboPol blazar monitoring program and the Nordic
Optical Telescope. We wish to understand if there are differences in the BL Lac
objects that are detected with the current-generation TeV instruments compared
to those that have not yet been detected. The mean polarization fraction of the
TeV-detected BL Lacs is 5% while the non-TeV sources show a higher mean
polarization fraction of 7%. This difference in polarization fraction
disappears when the dilution by the unpolarized light of the host galaxy is
accounted for. The TeV sources show somewhat lower fractional polarization
variability amplitudes than the non-TeV sources. Also the fraction of sources
with a smaller spread in the Q/I - U/I -plane and a clumped distribution of
points away from the origin, possibly indicating a preferred polarization
angle, is larger in the TeV than in the non-TeV sources. These differences
between TeV and non-TeV samples seems to arise from differences between
intermediate and high spectral peaking sources instead of the TeV detection.
When the EVPA variations are studied, the rate of EVPA change is similar in
both samples. We detect significant EVPA rotations in both TeV and non-TeV
sources, showing that rotations can occur in high spectral peaking BL Lac
objects when the monitoring cadence is dense enough. Our simulations show that
we cannot exclude a random walk origin for these rotations. These results
indicate that there are no intrinsic differences in the polarization properties
of the TeV-detected and non-TeV-detected high-energy BL Lac objects. This
suggests that the polarization properties are not directly related to the
TeV-detection, but instead the TeV loudness is connected to the general flaring
activity, redshift, and the synchrotron peak location. (Abridged)


title: Effect of a Locally Repulsive Interaction on s-wave Superconductors

abstract:
  The thermodynamic impact of the Coulomb repulsion on s-wave superconductors
is analyzed via a rigorous study of equilibrium and ground states of the strong
coupling BCS-Hubbard Hamiltonian. We show that the one-site electron repulsion
can favor superconductivity at fixed chemical potential by increasing the
critical temperature and/or the Cooper pair condensate density. If the one-site
repulsion is not too large, a first or a second order superconducting phase
transition can appear at low temperatures. The Mei\ss ner effect is shown to be
rather generic but coexistence of superconducting and ferromagnetic phases is
also shown to be feasible, for instance near half-filling and at strong
repulsion. Our proof of a superconductor-Mott insulator phase transition
implies a rigorous explanation of the necessity of doping insulators to create
superconductors. These mathematical results are consequences of "quantum large
deviation" arguments combined with an adaptation of the proof of St{\o}rmer's
theorem to even states on the CAR algebra.


title: Reverse-engineering invariant manifolds with asymptotic phase

abstract:
  We present a recipe for rendering a submanifold normally hyperbolic and
invariant within a stability basin. The construction includes the ability to
choose the asymptotic phase map. We are motivated by the notion of "templates
and anchors" -- the biomechanical observation that animal motions are often
governed by low dimensional dynamics -- and the growing applications in
robotics which desire means for making such biologically derived templates
govern the dynamics of robots. Our approach is fairly universal, in the sense
that a broad range of model reduction constructions must be normally hyperbolic
if they are robust, and a broad range of such normally hyperbolic systems can
be produces from our construction.


title:
Regularity theory and high order numerical methods for the
  (1d)-Fractional Laplacian

abstract:
  This paper presents regularity results and associated high-order numerical
methods for one-dimensional Fractional-Laplacian boundary-value problems. On
the basis of a factorization of solutions as a product of a certain
edge-singular weight $\omega$ times a "regular" unknown, a characterization of
the regularity of solutions is obtained in terms of the smoothness of the
corresponding right-hand sides. In particular, for right-hand sides which are
analytic in a Bernstein Ellipse, analyticity in the same Bernstein Ellipse is
obtained for the "regular" unknown. Moreover, a sharp Sobolev regularity result
is presented which completely characterizes the co-domain of the
Fractional-Laplacian operator in terms of certain weighted Sobolev spaces
introduced in (Babu\v{s}ka and Guo, SIAM J. Numer. Anal. 2002). The present
theoretical treatment relies on a full eigendecomposition for a certain
weighted integral operator in terms of the Gegenbauer polynomial basis. The
proposed Gegenbauer-based Nystr\"om numerical method for the
Fractional-Laplacian Dirichlet problem, further, is significantly more accurate
and efficient than other algorithms considered previously. The sharp error
estimates presented in this paper indicate that the proposed algorithm is
spectrally accurate, with convergence rates that only depend on the smoothness
of the right-hand side. In particular, convergence is exponentially fast (resp.
faster than any power of the mesh-size) for analytic (resp. in nitely smooth)
right-hand sides. The properties of the algorithm are illustrated with a
variety of numerical results.


title: Possible singlet and triplet superconductivity on honeycomb lattice

abstract:
  We study the possible superconducting pairing symmetry mediated by spin and
charge fluctuations on the honeycomb lattice using the extended Hubbard model
and the random-phase-approximation method. From $2\%$ to $20\%$ doping levels,
a spin-singlet $d_{x^{2}-y^{2}}+id_{xy}$-wave is shown to be the leading
superconducting pairing symmetry when only the on-site Coulomb interaction $U$
is considered, with the gap function being a mixture of the nearest-neighbor
and next-nearest-neighbor pairings. When the offset of the energy level between
the two sublattices exceeds a critical value, the most favorable pairing is a
spin-triplet $f$-wave which is mainly composed of the next-nearest-neighbor
pairing. We show that the next-nearest-neighbor Coulomb interaction $V$ is also
in favor of the spin-triplet $f$-wave pairing.


title:
Delay Performance of Wireless Communications with Imperfect CSI and
  Finite Length Coding

abstract:
  With the rise of critical machine-to-machine applications, next generation
wireless communication systems must be designed with strict constraints on the
latency and reliability. A key question in this context relates to channel
state estimation, which allows the transmitter to adapt the code rate to the
channel. In this work, we characterize the trade-off between the estimation
sequence length and data codeword length: shorter channel estimation leaves
more time for the actual payload transmission but reduces the estimation
accuracy and causes more decoding errors. Using lower coding rates can mitigate
this effect, but may result in a higher backlog of data at the transmitter. We
analyze this trade-off using queueing analysis on top of accurate models of the
physical layer, which also account for the finite blocklength of the channel
code. Based on a novel closed-form approximation for the error probability
given the rate, we show that finding the optimal rate adaptation strategy
becomes a convex problem. The optimal rate adaptation strategy and the optimal
training sequence length, which both depend on the latency and reliability
constraints of the application, can improve the delay performance by an order
of magnitude, compared to suboptimal strategies that do not consider those
constraints.


title:
Multi-frequency Studies of Massive Cores with Complex Spatial and
  Kinematic Structures

abstract:
  Five regions of massive star formation have been observed in various
molecular lines in the frequency range $\sim 85-89$ GHz. The studied regions
possess dense cores, which host young stellar objects. The physical parameters
of the cores are estimated, including kinetic temperatures ($\sim 20-40$ K),
sizes of the emitting regions ($\sim 0.1-0.6$ pc), and virial masses ($\sim
40-500 M_{\odot}$). Column densities and abundances of various molecules are
calculated in the local thermodynamical equilibrium approximation. The core in
99.982+4.17, associated with the weakest IRAS source, is characterized by
reduced molecular abundances. Molecular line widths decrease with increasing
distance from the core centers ($b$). For $b\ga 0.1$~pc, the dependences
$\Delta V(b)$ are close to power laws ($\propto b^{-p}$), where $p$ varies from
$\sim 0.2$ to $\sim 0.5$, depending on the object. In four cores, the
asymmetries of the optically thick HCN(1--0) and HCO$^+$(1--0) lines indicate
systematic motions along the line of sight: collapse in two cores and expansion
in two others. Approximate estimates of the accretion rates in the collapsing
cores indicate that the forming stars have masses exceeding the solar mass.


title: BreakID: Static Symmetry Breaking for ASP (System Description)

abstract:
  Symmetry breaking has been proven to be an efficient preprocessing technique
for satisfiability solving (SAT). In this paper, we port the state-of-the-art
SAT symmetry breaker BreakID to answer set programming (ASP). The result is a
lightweight tool that can be plugged in between the grounding and the solving
phases that are common when modelling in ASP. We compare our tool with sbass,
the current state-of-the-art symmetry breaker for ASP.


title: New Formulas for Amplitudes from Higher-Dimensional Operators

abstract:
  In this paper we study tree-level amplitudes from higher-dimensional
operators, including $F^3$ operator of gauge theory, and $R^2$, $R^3$ operators
of gravity, in the Cachazo-He-Yuan formulation. As a generalization of the
reduced Pfaffian in Yang-Mills theory, we find a new, gauge-invariant object
that leads to gluon amplitudes with a single insertion of $F^3$, and gravity
amplitudes by Kawai-Lewellen-Tye relations. When reduced to four dimensions for
given helicities, the new object vanishes for any solution of scattering
equations on which the reduced Pfaffian is non-vanishing. This intriguing
behavior in four dimensions explains the vanishing of graviton helicity
amplitudes produced by the Gauss-Bonnet $R^2$ term, and provides a
scattering-equation origin of the decomposition into self-dual and
anti-self-dual parts for $F^3$ and $R^3$ amplitudes.


title: On powers of half-twists in M(0,2n)

abstract:
  We use elementary skein theory to prove a version of a result of Stylianakis
who showed that under mild restrictions on m and n, the normal closure of the
m-th power of a half-twist has infinite index in the mapping class group of a
sphere with 2n punctures.