title: Application of Modal Filtering to a Spectral Difference Method

abstract:
  We adapt the spectral viscosity (SV) formulation implemented as a modal
filter to a Spectral Difference Method (SD) solving hyperbolic conservation
laws. In the SD Method we use selections of different orthogonal polynomials
(APK polynomials). Furthermore we obtain new error bounds for filtered APK
extensions of smooth functions. We demonstrate that the modal filter also
depends on the chosen polynomial basis in the SD Method. Spectral filtering
stabilizes the scheme and leaves weaker oscillations. Hence, the selection of
the family of orthogonal polynomials on triangles and their specific modal
filter possesses a positive influence on the stability and accuracy of the SD
Method. In the second part, we initiate a stability analysis for a linear
scalar test case with periodic initial condition to find the best selection of
APK polynomials and their specific modal filter. To the best of our knowledge,
this work is the first that gives a stability analysis for a scheme with
spectral filtering. Finally, we demonstrate the influence of the underlying
basis of APK polynomials in a well-known test case.


title: Existence of the equilibrium in choice

abstract:
  In this paper, we prove the existence of the equilibrium in choice for games
in choice form. These games have recently been introduced by A. Stefanescu, M.
Ferrara and M. V. Stefanescu. Our results link the recent research to the older
approaches, regarding games in normal form or qualitative games.


title:
Leading order response of statistical averages of a dynamical system to
  small stochastic perturbations

abstract:
  The classical fluctuation-dissipation theorem predicts the average response
of a dynamical system to an external deterministic perturbation via time-lagged
statistical correlation functions of the corresponding unperturbed system. In
this work we develop a fluctuation-response theory and test a computational
framework for the leading order response of statistical averages of a
deterministic or stochastic dynamical system to an external stochastic
perturbation. In the case of a stochastic unperturbed dynamical system, we
compute the leading order fluctuation-response formulas for two different
cases: when the existing stochastic term is perturbed, and when a new,
statistically independent, stochastic perturbation is introduced. We
numerically investigate the effectiveness of the new response formulas for an
appropriately rescaled Lorenz 96 system, in both the deterministic and
stochastic unperturbed dynamical regimes.


title: Asking the metaquestions in constraint tractability

abstract:
  The constraint satisfaction problem (CSP) involves deciding, given a set of
variables and a set of constraints on the variables, whether or not there is an
assignment to the variables satisfying all of the constraints. One formulation
of the CSP is as the problem of deciding, given a pair (G,H) of relational
structures, whether or not there is a homomorphism from the first structure to
the second structure. The CSP is in general NP-hard; a common way to restrict
this problem is to fix the second structure H, so that each structure H gives
rise to a problem CSP(H). The problem family CSP(H) has been studied using an
algebraic approach, which links the algorithmic and complexity properties of
each problem CSP(H) to a set of operations, the so-called polymorphisms of H.
Certain types of polymorphisms are known to imply the polynomial-time
tractability of $CSP(H)$, and others are conjectured to do so. This article
systematically studies---for various classes of polymorphisms---the
computational complexity of deciding whether or not a given structure H admits
a polymorphism from the class. Among other results, we prove the
NP-completeness of deciding a condition conjectured to characterize the
tractable problems CSP(H), as well as the NP-completeness of deciding if CSP(H)
has bounded width.


title:
Entity Type Recognition using an Ensemble of Distributional Semantic
  Models to Enhance Query Understanding

abstract:
  We present an ensemble approach for categorizing search query entities in the
recruitment domain. Understanding the types of entities expressed in a search
query (Company, Skill, Job Title, etc.) enables more intelligent information
retrieval based upon those entities compared to a traditional keyword-based
search. Because search queries are typically very short, leveraging a
traditional bag-of-words model to identify entity types would be inappropriate
due to the lack of contextual information. Our approach instead combines clues
from different sources of varying complexity in order to collect real-world
knowledge about query entities. We employ distributional semantic
representations of query entities through two models: 1) contextual vectors
generated from encyclopedic corpora like Wikipedia, and 2) high dimensional
word embedding vectors generated from millions of job postings using word2vec.
Additionally, our approach utilizes both entity linguistic properties obtained
from WordNet and ontological properties extracted from DBpedia. We evaluate our
approach on a data set created at CareerBuilder; the largest job board in the
US. The data set contains entities extracted from millions of job
seekers/recruiters search queries, job postings, and resume documents. After
constructing the distributional vectors of search entities, we use supervised
machine learning to infer search entity types. Empirical results show that our
approach outperforms the state-of-the-art word2vec distributional semantics
model trained on Wikipedia. Moreover, we achieve micro-averaged F 1 score of
97% using the proposed distributional representations ensemble.


title: On the bipartite graph packing problem

abstract:
  The graph packing problem is a well-known area in graph theory. We consider a
bipartite version and give almost tight conditions on the packability of two
bipartite sequences.


title: A Time Projection Chamber with GEM-Based Readout

abstract:
  For the International Large Detector concept at the planned International
Linear Collider, the use of time projection chambers (TPC) with micro-pattern
gas detector readout as the main tracking detector is investigated. In this
paper, results from a prototype TPC, placed in a 1 T solenoidal field and read
out with three independent GEM-based readout modules, are reported. The TPC was
exposed to a 6 GeV electron beam at the DESY II synchrotron. The efficiency for
reconstructing hits, the measurement of the drift velocity, the space point
resolution and the control of field inhomogeneities are presented.


title: Structural Multi-type Sequent Calculus for Inquisitive Logic

abstract:
  In this paper, we define a multi-type calculus for inquisitive logic, which
is sound, complete and enjoys Belnap-style cut-elimination and subformula
property. Inquisitive logic is the logic of inquisitive semantics, a semantic
framework developed by Groenendijk, Roelofsen and Ciardelli which captures both
assertions and questions in natural language. Inquisitive logic is sound and
complete w.r.t. the so-called state semantics (also known as team semantics).
The Hilbert-style presentation of inquisitive logic is not closed under uniform
substitution; indeed, some occurrences of formulas are restricted to a certain
subclass of formulas, called flat formulas. This and other features make the
quest for analytic calculi for this logic not straightforward. We develop a
certain algebraic and order-theoretic analysis of the team semantics, which
provides the guidelines for the design of a multi-type environment which
accounts for two domains of interpretation, for flat and for general formulas,
as well as for their interaction. This multi-type environment in its turn
provides the semantic environment for the multi-type calculus for inquisitive
logic we introduce in this paper.


title:
Far-field Superresolution of Thermal Electromagnetic Sources at the
  Quantum Limit

abstract:
  We obtain the ultimate quantum limit for estimating the transverse separation
of two thermal point sources using a given imaging system with limited spatial
bandwidth. We show via the quantum Cram\'er-Rao bound that, contrary to the
Rayleigh limit in conventional direct imaging, quantum mechanics does
notmandate any loss of precision in estimating even deep sub-Rayleigh
separations. We propose two coherent measurement techniques, easily
implementable using current linear-optics technology, that approach the quantum
limit over an arbitrarily large range of separations. Our bound is valid for
arbitrary source strengths, all regions of the electromagnetic spectrum, and
for any imaging system with an inversion-symmetric point-spread function. The
measurement schemes can be applied to microscopy, optical sensing, and
astrometry at all wavelengths.


title: Multi-Field Structural Decomposition for Question Answering

abstract:
  This paper presents a precursory yet novel approach to the question answering
task using structural decomposition. Our system first generates linguistic
structures such as syntactic and semantic trees from text, decomposes them into
multiple fields, then indexes the terms in each field. For each question, it
decomposes the question into multiple fields, measures the relevance score of
each field to the indexed ones, then ranks all documents by their relevance
scores and weights associated with the fields, where the weights are learned
through statistical modeling. Our final model gives an absolute improvement of
over 40% to the baseline approach using simple search for detecting documents
containing answers.


title:
Exact asymptotic correlation functions of bilinear spin operators of the
  Heisenberg antiferromagnetic spin-$\frac{1}{2}$ chain

abstract:
  Exact asymptotic expressions of the uniform parts of the two-point
correlation functions of bilinear spin operators in the Heisenberg
antiferromagnetic spin-$\frac{1}{2}$ chain are obtained. Apart from the
algebraic decay, the logarithmic contribution is identified, and the numerical
prefactor is determined. We also confirm numerically the multiplicative
logarithmic correction of the staggered part of the bilinear spin operators
$\langle\langle S^{a}_0S^{a}_{1}S^{b}_{r}S^{b}_{r+1} \rangle\rangle=(-1)^rd/(r
\ln^{\frac{3}{2}}r) +(3\delta_{a,b}-1) \ln^2r /(12 \pi^4 r^4)$, and estimate
the numerical prefactor as $d\simeq 0.067$. The relevance of our results for
ground state fidelity susceptibility at the Berezinskii-Kosterlitz-Thouless
quantum phase transition points in one-dimensional systems is discussed at the
end of our work.


title:
Continuous Cold-atom Inertial Sensor with $1\ \text{nrad.s}^{-1}$
  Rotation Stability

abstract:
  We report the operation of a cold-atom inertial sensor which continuously
captures the rotation signal. Using a joint interrogation scheme, where we
simultaneously prepare a cold-atom source and operate an atom interferometer
(AI) enables us to eliminate the dead times. We show that such continuous
operation improves the short-term sensitivity of AIs, and demonstrate a
rotation sensitivity of $100\ \text{nrad.s}^{-1}.\text{Hz}^{-1/2}$ in a
cold-atom gyroscope of $11 \ \text{cm}^2$ Sagnac area. We also demonstrate a
rotation stability of $1 \ \text{nrad.s}^{-1}$ at $10^4$ s of integration time,
which establishes the record for atomic gyroscopes. The continuous operation of
cold-atom inertial sensors will enable to benefit from the full sensitivity
potential of large area AIs, determined by the quantum noise limit.


title: Quantum mock modular forms arising from eta-theta functions

abstract:
  In 2013, Lemke Oliver classified all eta-quotients which are theta functions.
In this paper, we unify the eta-theta functions by constructing mock modular
forms from the eta-theta functions with even characters, such that the shadows
of these mock modular forms are given by the eta-theta functions with odd
characters. In addition, we prove that our mock modular forms are quantum
modular forms. As corollaries, we establish simple finite hypergeometric
expressions which may be used to evaluate Eichler integrals of the odd
eta-theta functions, as well as some curious algebraic identities.


title:
High Enough? Explaining and Predicting Traveler Satisfaction Using
  Airline Review

abstract:
  Air travel is one of the most frequently used means of transportation in our
every-day life. Thus, it is not surprising that an increasing number of
travelers share their experiences with airlines and airports in form of online
reviews on the Web. In this work, we thrive to explain and uncover the features
of airline reviews that contribute most to traveler satisfaction. To that end,
we examine reviews crawled from the Skytrax air travel review portal. Skytrax
provides four review categories to review airports, lounges, airlines and
seats. Each review category consists of several five-star ratings as well as
free-text review content. In this paper, we conducted a comprehensive feature
study and we find that not only five-star rating information such as airport
queuing time and lounge comfort highly correlate with traveler satisfaction but
also textual features in the form of the inferred review text sentiment. Based
on our findings, we created classifiers to predict traveler satisfaction using
the best performing rating features. Our results reveal that given our
methodology, traveler satisfaction can be predicted with high accuracy.
Additionally, we find that training a model on the sentiment of the review text
provides a competitive alternative when no five star rating information is
available. We believe that our work is of interest for researchers in the area
of modeling and predicting user satisfaction based on available review data on
the Web.


title:
Temperature dependent excitonic effects in the optical properties of
  single-layer MoS$_2$

abstract:
  Temperature influences the performance of two-dimensional materials in
optoelectronic devices. Indeed, the optical characterization of these materials
is usually realized at room temperature. Nevertheless most {\it ab-initio}
studies are yet performed without including any temperature effect. As a
consequence, important features are thus overlooked, such as the relative
intensity of the excitonic peaks and their broadening, directly related to the
temperature and to the non-radiative exciton relaxation time. We present {\it
ab-initio} calculations of the optical response of single-layer MoS$_2$, a
prototype 2D material, as a function of temperature using density functional
theory and many-body perturbation theory. We compute the electron-phonon
interaction using the full spinorial wave functions, i.e., fully taking into
account effects of spin-orbit interaction. We find that bound excitons ($A$ and
$B$ peaks) and resonant excitons ($C$ peak) exhibit different behavior with
temperature, displaying different non-radiative linewidths. We conclude that
the inhomogeneous broadening of the absorption spectra is mainly due to
electron-phonon scattering mechanisms. Our calculations explain the
shortcomings of previous (zero-temperature) theoretical spectra and match well
with the experimental spectra acquired at room temperature. Moreover, we
disentangle the contributions of acoustic and optical phonon modes to the
quasi-particles and exciton linewidths. Our model also allows to identify which
phonon modes couple to each exciton state, useful for the interpretation of
resonant Raman scattering experiments.


title: Analysis of Time-Domain Scattering by Periodic Structures

abstract:
  This paper is devoted to the mathematical analysis of a time-domain
electromagnetic scattering by periodic structures which are known as
diffraction gratings. The scattering problem is reduced equivalently into an
initial-boundary value problem in a bounded domain by using an exact
transparent boundary condition. The well-posedness and stability of the
solution are established for the reduced problem. Moreover, a priori energy
estimates are obtained with minimum regularity requirement for the data and
explicit dependence on the time.


title: Memory Dependent Growth in Sublinear Volterra Differential Equations

abstract:
  We investigate memory dependent asymptotic growth in scalar Volterra
equations with sublinear nonlinearity. To obtain precise results we utilise the
powerful theory of regular variation extensively. By computing the growth rate
in terms of a related ordinary differential equation we show that when the
memory effect is so strong that the kernel tends to infinity, the growth rate
of solutions depends explicitly on the memory of the system. Finally, we employ
a fixed point argument to determine analogous results for a perturbed Volterra
equation and show that, for a sufficiently large perturbation, the solution
tracks the perturbation asymptotically, even when the forcing term is
potentially highly non-monotone.


title:
The evolution of a supermassive retrograde binary embedded in an
  accretion disk

abstract:
  In this note we discuss the main results of a study of a massive binary with
unequal mass ratio, q, embedded in an accretion disk, with its orbital rotation
being opposed to that of the disk. When the mass ratio is sufficiently large, a
gap opens in the disk, but the mechanism of gap formation is very different
from the prograde case. Inward migration occurs on a timescale of t_ev ~
M_p/(dot M), where M_p is the mass of the less massive component (the
perturber), and dot M is the accretion rate. When q<< 1, the accretion takes
place mostly onto the more massive component, with the accretion rate onto the
perturber being smaller than, or of order of, q^(1/3)M. However, this rate
increases when supermassive binary black holes are considered and gravitational
wave emission is important. We estimate a typical duration of time for which
the accretion onto the perturber and gravitational waves could be detected.


title:
Fourth order real space solver for the time-dependent Schr\"odinger
  equation with singular Coulomb potential

abstract:
  We present a novel numerical method and algorithm for the solution of the 3D
axially symmetric time-dependent Schr\"odinger equation in cylindrical
coordinates, involving singular Coulomb potential terms besides a smooth
time-dependent potential. We use fourth order finite difference real space
discretization, with special formulae for the arising Neumann and Robin
boundary conditions along the symmetry axis. Our propagation algorithm is based
on merging the method of the split-operator approximation of the exponential
operator with the implicit equations of second order cylindrical 2D
Crank-Nicolson scheme. We call this method hybrid splitting scheme because it
inherits both the speed of the split step finite difference schemes and the
robustness of the full Crank-Nicolson scheme. Based on a thorough error
analysis, we verified both the fourth order accuracy of the spatial
discretization in the optimal spatial step size range, and the fourth order
scaling with the time step in the case of proper high order expressions of the
split-operator. We demonstrate the performance and high accuracy of our hybrid
splitting scheme by simulating optical tunneling from a hydrogen atom due to a
few-cycle laser pulse with linear polarization.


title:
Finite-size corrections to scaling of the magnetization distribution in
  the $2d$ $XY$-model at zero temperature

abstract:
  The zero-temperature, classical $XY$-model on an $L \times L$ square-lattice
is studied by exploring the distribution $\Phi_L(y)$ of its centered and
normalized magnetization $y$ in the large $L$ limit. An integral representation
of the cumulant generating function, known from earlier works, is used for the
numerical evaluation of $\Phi_L(y)$, and the limit distribution $\Phi_{L
\rightarrow \infty} (y) = \Phi_0(y)$ is obtained with high precision. The two
leading finite-size corrections $\Phi_L (y) -\Phi_0 (y) \approx a_1(L)\,
\Phi_1(y) + a_2(L)\,\Phi_2(y)$ are also extracted both from numerics and from
analytic calculations. We find that the amplitude $a_1(L)$ scales as
$\ln(L/L_0) /L^2$ and the shape correction function $\Phi_1 (y)$ can be
expressed through the low-order derivatives of the limit distribution, $\Phi_1
(y) = [\,y\, \Phi_0 (y) + \Phi'_0 (y)\,]'$. The second finite-size correction
has an amplitude $a_2(L)\propto 1/L^2$ and one finds that $a_2\,\Phi_2(y) \ll
a_1 \,\Phi_1(y)$ already for small system size ($L> 10$). We illustrate the
feasibility of observing the calculated finite-size corrections by performing
simulations of the $XY$-model at low temperatures, including $T = 0$.


title: Active matter clusters at interfaces

abstract:
  Collective and directed motility or swarming is an emergent phenomenon
displayed by many self-organized assemblies of active biological matter such as
clusters of embryonic cells during tissue development, cancerous cells during
tumor formation and metastasis, colonies of bacteria in a biofilm, or even
flocks of birds and schools of fish at the macro-scale. Such clusters typically
encounter very heterogeneous environments. What happens when a cluster
encounters an interface between two different environments has implications for
its function and fate. Here we study this problem by using a mathematical model
of a cluster that treats it as a single cohesive unit that moves in two
dimensions by exerting a force/torque per unit area whose magnitude depends on
the nature of the local environment. We find that low speed (overdamped)
clusters encountering an interface with a moderate difference in properties can
lead to refraction or even total internal reflection of the cluster. For large
speeds (underdamped), where inertia dominates, the clusters show more complex
behaviors crossing the interface multiple times and deviating from the
predictable refraction and reflection for the low velocity clusters. We then
present an extreme limit of the model in the absense of rotational damping
where clusters can become stuck spiraling along the interface or move in large
circular trajectories after leaving the interface. Our results show a wide
range of behaviors that occur when collectively moving active biological matter
moves across interfaces and these insights can be used to control motion by
patterning environments.


title:
Ultra faint dwarf galaxies: an arena for testing dark matter versus
  modified gravity

abstract:
  The scenario consistent with a wealth of observations for the missing mass
problem is that of weakly interacting dark matter particles. However, arguments
or proposals for a Newtonian or relativistic modified gravity scenario continue
to be made. A distinguishing characteristic between the two scenarios is that
dark matter particles can produce a gravitational effect, in principle, without
the need of baryons while this is not the case for the modified gravity
scenario where such an effect must be correlated with the amount of baryonic
matter. We consider here ultra-faint dwarf (UFD) galaxies as a promising arena
to test the two scenarios based on the above assertion. We compare the
correlation of the luminosity with the velocity dispersion between samples of
UFD and non-UFD galaxies, finding a significant loss of correlation for UFD
galaxies. For example, we find for 28 non-UFD galaxies a strong correlation
coefficient of -0.688 which drops to -0.077 for the 23 UFD galaxies. Incoming
and future data will determine whether the observed stochasticity for UFD
galaxies is physical or due to systematics in the data. Such a loss of
correlation (if it is to persist) is possible and consistent with the dark
matter scenario for UFD galaxies but would constitute a new challenge for the
modified gravity scenario.


title: General Relativity for Pedestrians -- First 6 lectures

abstract:
  The 2017 Nobel Prize in physics awarded to Rainer Weiss, Barry C. Barish and
Kip S. Thorne has generated unprecedented interest in gravitational waves
(GWs). These notes are based on my lectures on various occasions - in the
University of Delhi as well as in different GW schools held in India following
the exciting direct detection of GWs. I discuss GW flux and luminosity while
pointing out a curious aspect associated with the latter - physical dimensions
of $c^5/G$ as well as third time derivative of mass quadrupole moment are that
of luminosity. Formation of primordial black holes in the early universe and
progenitors of fast radio bursts could have generated GW luminosity comparable
to the Planck luminosity, $c^5/G$. I also address the issue of black hole
thermodynamics in connection with the GW150914 event, demonstrating that this
event is consistent with Hawking's black hole area theorem. In the last
section, as an illustrative exercise, I estimate the GW amplitude expected from
the fast moving plasma bullets that have been shot out from the vicinity of the
carbon star V Hydrae, as reported recently by Sahai et al. (2016).


title:
Profit-Maximizing Planning and Control of Battery Energy Storage Systems
  for Primary Frequency Control

abstract:
  We consider a two-level profit-maximizing strategy, including planning and
control, for battery energy storage system (BESS) owners that participate in
the primary frequency control (PFC) market. Specifically, the optimal BESS
control minimizes the operating cost by keeping the state of charge (SoC) in an
optimal range. Through rigorous analysis, we prove that the optimal BESS
control is a "state-invariant" strategy in the sense that the optimal SoC range
does not vary with the state of the system. As such, the optimal control
strategy can be computed offline once and for all with very low complexity.
Regarding the BESS planning, we prove that the the minimum operating cost is a
decreasing convex function of the BESS energy capacity. This leads to the
optimal BESS sizing that strikes a balance between the capital investment and
operating cost. Our work here provides a useful theoretical framework for
understanding the planning and control strategies that maximize the economic
benefits of BESSs in ancillary service markets.


title: How far from equilibrium is active matter?

abstract:
  Active matter systems are driven out of thermal equilibrium by a lack of
generalized Stokes-Einstein relation between injection and dissipation of
energy at the microscopic scale. We consider such a system of interacting
particles, propelled by persistent noises, and show that, at small but finite
persistence time, their dynamics still satisfy a time-reversal symmetry. To do
so, we compute perturbatively their steady-state measure and show that, for
short persistent times, the entropy production rate vanishes. This endows such
systems with an effective Fluctuation-Dissipation theorem akin to that of
thermal equilibrium systems. Last we show how interacting particle systems with
viscous drags and correlated noises can be seen as in equilibrium with a
visco-elastic bath but driven out of equilibrium by non-conservative forces,
hence providing an energetic insight on the departure of active systems from
equilibrium.


title:
Inference on the tail process with application to financial time series
  modelling

abstract:
  To draw inference on serial extremal dependence within heavy-tailed Markov
chains, Drees, Segers and Warcho{\l} [Extremes (2015) 18, 369--402] proposed
nonparametric estimators of the spectral tail process. The methodology can be
extended to the more general setting of a stationary, regularly varying time
series. The large-sample distribution of the estimators is derived via
empirical process theory for cluster functionals. The finite-sample performance
of these estimators is evaluated via Monte Carlo simulations. Moreover, two
different bootstrap schemes are employed which yield confidence intervals for
the pre-asymptotic spectral tail process: the stationary bootstrap and the
multiplier block bootstrap. The estimators are applied to stock price data to
study the persistence of positive and negative shocks.


title: AGILE Observations of the Gravitational Wave Event GW150914

abstract:
  We report the results of an extensive search in the AGILE data for a
gamma-ray counterpart of the LIGO gravitational wave event GW150914. Currently
in spinning mode, AGILE has the potential of covering with its gamma-ray
instrument 80 % of the sky more than 100 times a day. It turns out that AGILE
came within a minute from the event time of observing the accessible GW150914
localization region. Interestingly, the gamma-ray detector exposed about 65 %
of this region during the 100 s time intervals centered at -100 s and +300 s
from the event time. We determine a 2-sigma flux upper limit in the band 50 MeV
- 10 GeV, $UL = 1.9 \times 10^{-8} \rm \, erg \, cm^{-2} \, s^{-1}$ obtained
about 300 s after the event. The timing of this measurement is the fastest ever
obtained for GW150914, and significantly constrains the electromagnetic
emission of a possible high-energy counterpart. We also carried out a search
for a gamma-ray precursor and delayed emission over timescales ranging from
minutes to days: in particular, we obtained an optimal exposure during the
interval -150 / -30 s. In all these observations, we do not detect a
significant signal associated with GW150914. We do not reveal the weak
transient source reported by Fermi-GBM 0.4 s after the event time. However,
even though a gamma-ray counterpart of the GW150914 event was not detected, the
prospects for future AGILE observations of gravitational wave sources are
decidedly promising.


title:
Fast Estimator of jacobians in Monte Carlo Integration on Lefschetz
  Thimbles

abstract:
  A solution to the sign problem is the so-called "Lefschetz thimble approach"
where the domain of integration for field variables in the path integral is
deformed from the real axis to a sub-manifold in the complex space. For
properly chosen sub-manifolds ("thimbles") the sign problem disappears or is
drastically alleviated. The parametrization of the thimble by real coordinates
require the calculation of a jacobian with a computational cost of order
O(V^3), where V is proportional to the spacetime volume. In this note we
propose two estimators for this jacobian with a computational cost of order
O(V). We discuss analytically the regimes where we expect the estimator to work
and show numerical examples in two different models.


title:
Imry-Ma disordered state induced by defects of "random local anisotropy"
  type in the system with O(n) symmetry

abstract:
  For the system with the n-component order parameter (O(n)-model), conditions
for initiation of the Imry-Ma disordered state resulting from the influence of
defects of the "random local anisotropy" type were discovered. The initiation
of such a state was shown to be possible if the distribution of local
anisotropy axes directions in the order parameter space is nearly isotropic,
and the limiting degree of the distribution anisotropy was found. For a higher
anisotropy in the distribution of local axes directions, the long-range order
in the system holds true even in the presence of defects of the given type.


title:
Radioactive Iron Rain: Transporting $^{60}$Fe in Supernova Dust to the
  Ocean Floor

abstract:
  Several searches have found evidence of $^{60}$Fe deposition, presumably from
a near-Earth supernova (SN), with concentrations that vary in different
locations on Earth. This paper examines various influences on the path of
interstellar dust carrying $^{60}$Fe from a SN through the heliosphere, with
the aim of estimating the final global distribution on the ocean floor. We
study the influences of magnetic fields, angle of arrival, wind and ocean
cycling of SN material on the concentrations at different locations. We find
that the passage of SN material through the mesosphere/lower thermosphere (MLT)
is the greatest influence on the final global distribution, with ocean cycling
causing lesser alteration as the SN material sinks to the ocean floor. SN
distance estimates in previous works that assumed a uniform distribution are a
good approximation. Including the effects on surface distributions, we estimate
a distance of $46^{+10}_{-6}$ pc for a $8-10 \ M_{\odot}$ SN progenitor. This
is consistent with a SN occurring within the Tuc-Hor stellar group $\sim$2.8
Myr ago with SN material arriving on Earth $\sim$2.2 Myr ago. We note that the
SN dust retains directional information to within $1^{\circ}$ through its
arrival in the inner Solar System, so that SN debris deposition on inert bodies
such as the Moon will be anisotropic, and thus could in principle be used to
infer directional information. In particular, we predict that existing lunar
samples should show measurable $^{60}$Fe differences.


title:
The semaphore codes attached to a Turing machine via resets and their
  various limits

abstract:
  We introduce semaphore codes associated to a Turing machine via resets.
Semaphore codes provide an approximation theory for resets. In this paper we
generalize the set-up of our previous paper "Random walks on semaphore codes
and delay de Bruijn semigroups" to the infinite case by taking the profinite
limit of $k$-resets to obtain $(-\omega)$-resets. We mention how this opens new
avenues to attack the P versus NP problem.


title: Counting Blanks in Polygonal Arrangements

abstract:
  Inside a two dimensional region ("cake"), there are $m$ non-overlapping tiles
of a certain kind ("toppings"). We want to expand the toppings while keeping
them non-overlapping, and possibly add some blank pieces of the same "certain
kind", such that the entire cake is covered. How many blanks must we add?
  We study this question in several cases: (1) The cake and toppings are
general polygons. (2) The cake and toppings are convex figures. (3) The cake
and toppings are axes-parallel rectangles. (4) The cake is an axes-parallel
rectilinear polygon and the toppings are axes-parallel rectangles. In all four
cases, we provide tight bounds on the number of blanks.


title:
Unusual Kondo-hole effect and crystal-field frustration in Nd-doped
  CeRhIn$_{5}$

abstract:
  We investigate single crystalline samples of Ce$_{1-x}$Nd$_{x}$RhIn$_{5}$ by
means of X-ray diffraction, microprobe, magnetic susceptibility, heat capacity,
and electrical resistivity measurements. Our data reveal that the
antiferromagnetic transition temperature of CeRhIn$_{5}$, $T_{N}^{\mathrm{Ce}}
= 3.8$ K, is linearly suppressed with $x_{\mathrm{Nd}}$, by virtue of the
"Kondo hole" created by Nd substitution. The extrapolation of
$T^{\mathrm{Ce}}_{N}$ to zero temperature, however, occurs at $x_{c} \sim 0.3$,
which is below the 2D percolation limit found in Ce$_{1-x}$La$_{x}$RhIn$_{5}$.
This result strongly suggests the presence of crystal-field frustration
effects. Near $x_{\mathrm{Nd}} \sim 0.2$, the Ising AFM order from Nd ions is
stabilized and $T^{\mathrm{Nd}}_{N}$ increases up to $11$ K in pure
NdRhIn$_{5}$. Our results shed light on the effects of magnetic doping in
heavy-fermion antiferromagnets and stimulate the study of such systems under
applied pressure.


title: A lattice point counting generalisation of the Tutte polynomial

abstract:
  The Tutte polynomial for matroids is not directly applicable to polymatroids.
For instance, deletion-contraction properties do not hold. We construct a
polynomial for polymatroids which behaves similarly to the Tutte polynomial of
a matroid, and in fact contains the same information as the Tutte polynomial
when we restrict to matroids. This polynomial is constructed using lattice
point counts in the Minkowski sum of the base polytope of a polymatroid and
scaled copies of the standard simplex. We also show that, in the matroid case,
our polynomial has coefficients of alternating sign, with a combinatorial
interpretation closely tied to the Dawson partition.


title: Dynamical leaps due to microscopic changes in multiplex networks

abstract:
  Recent developments of the multiplex paradigm included efforts to understand
the role played by the presence of several layers on the dynamics of processes
running on these networks. The possible existence of new phenomena associated
to the richer topology has been discussed and examples of these differences
have been systematically searched. Here, we show that the interconnectivity of
the layers may have an important impact on the speed of the dynamics run in the
network and that microscopic changes such as the addition of one single
inter-layer link can notably affect the arrival at a global stationary state.
As a practical verification, these results obtained with spectral techniques
are confirmed with a Kuramoto dynamics for which the synchronization
consistently delays after the addition of single inter-layer links.


title:
Production of tau lepton pairs with high pT jets at the LHC and the
  TauSpinner reweighting algorithm

abstract:
  The TauSpinner algorithm allows to modify the physics of the Monte Carlo
generated samples due to the changed assumptions of event production dynamics,
without re-generating events. To each event it attributes weights: the spin
effects of tau-lepton production or decay, or the production mechanism are
modified. There is no need to repeat the detector response simulation. We
document the extension to 2 to 4 processes in which the matrix elements for the
parton-parton scattering amplitudes into a tau-lepton pair and two outgoing
partons are used. Tree-level matrix elements for the Standard Model processes,
including the Higgs boson production are used. Automatically generated codes by
MadGraph5 have been adapted. Tests of the matrix elements, reweighting
algorithm and numerical results are presented. For averaged tau lepton
polarisation, we perform comparison of 2 to 2 and 2 to 4 matrix elements used
to calculate the spin weight in pp to tau tau j j events. We show, that for
events with tau-lepton pair close to the Z-boson peak, the tau-lepton
polarisation calculated using 2 to 4 matrix elements is very close to the one
calculated using 2 to 2 Born process only. For the m_(tautau) masses above the
Z-boson peak, the effect from including 2 to 4 matrix elements is also
marginal, however when restricting into subprocesses qq,q bar q to tau tau j j
only, it can lead to a 10% difference on the predicted tau-lepton polarisation.
Choice of electroweak scheme can have significant impact. The modification of
the electroweak or strong interaction can be performed with the re-weighting
technique. TauSpinner v.2.0.0, allows to introduce non-standard couplings for
the Higgs boson and study their effects in the vector-boson-fusion. The
discussion is relegated to forthcoming publications.


title: Localized Excitations from Localized Unitary Operators

abstract:
  Localized unitary operators are basic probes of locality and causality in
quantum systems: localized unitary operators create localized excitations in
entangled states. Working with an explicit form, we explore the properties of
these operators in quantum mechanics and quantum field theory. We show that,
unlike unitary operators, local non-unitary operators generically create
non-local excitations. We present a local picture for quantum systems in which
localized experimentalists can only act through localized Hamiltonian
deformations, and therefore localized unitary operators. We demonstrate that
localized unitary operators model certain quantum quenches exactly. We show how
the Reeh-Schlieder theorem follows intuitively from basic properties of
entanglement, non-unitary operators, and the local picture. We show that a
recent quasi-particle picture for excited-state entanglement entropy in
conformal field theories is not universal for all local operators. We prove a
causality relation for entanglement entropy and connect our results to the
AdS/CFT correspondence.

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


title:
Comparison of Diffuse Infrared and Far-Ultraviolet emission in the Large
  Magellanic Cloud: The Data

abstract:
  Dust scattering is the main source of diffuse emission in the far-ultraviolet
(FUV). For several locations in the Large Magellanic Cloud (LMC), Far
Ultraviolet Spectroscopic Explorer (FUSE) satellite has observed diffuse
radiation in the FUV with intensities ranging from 1000 - 3 X 10^5 photon units
and diffuse fraction between 5% - 20% at 1100 {\deg}A. Here, we compare the FUV
diffuse emission with the mid-infrared (MIR) and far-infrared (FIR) diffuse
emission observed by the Spitzer Space Telescope and the AKARI satellite for
the same locations. The intensity ratios in the different MIR and FIR bands for
each of the locations will enable us to determine the type of dust contributing
to the diffuse emission as well as to derive a more accurate 3D distribution of
stars and dust in the region, which in turn may be used to model the observed
scattering in the FUV. In this work we present the infrared (IR) data for two
different regions in LMC, namely N11 and 30 Doradus. We also present the FUV~IR
correlation for different infrared bands.


title: Verification of Hierarchical Artifact Systems

abstract:
  Data-driven workflows, of which IBM's Business Artifacts are a prime
exponent, have been successfully deployed in practice, adopted in industrial
standards, and have spawned a rich body of research in academia, focused
primarily on static analysis. The present work represents a significant advance
on the problem of artifact verification, by considering a much richer and more
realistic model than in previous work, incorporating core elements of IBM's
successful Guard-Stage-Milestone model. In particular, the model features task
hierarchy, concurrency, and richer artifact data. It also allows database key
and foreign key dependencies, as well as arithmetic constraints. The results
show decidability of verification and establish its complexity, making use of
novel techniques including a hierarchy of Vector Addition Systems and a variant
of quantifier elimination tailored to our context.


title:
Binding in light nuclei: Statistical NN uncertainties vs Computational
  accuracy

abstract:
  We analyse the impact of the statistical uncertainties of the the
nucleon-nucleon interaction, based on the Granada-2013 np-pp database, on the
binding energies of the triton and the alpha particle using a bootstrap method,
by solving the Faddeev equations for $^3$H and the Yakubovsky equations for
$^4$He respectively. We check that in practice about 30 samples prove enough
for a reliable error estimate. An extrapolation of the well fulfilled Tjon-line
correlation predicts the experimental binding of the alpha particle within
uncertainties.


title: Topological Coarse Shape Homotopy Groups

abstract:
  Uchillo-Ibanez et al. introduced a topology on the sets of shape morphisms
between arbitrary topological spaces in 1999. In this paper, applying a similar
idea, we introduce a topology on the set of coarse shape morphisms $Sh^*(X,Y)$,
for arbitrary topological spaces $X$ and $Y$. In particular, we can consider a
topology on the coarse shape homotopy group of a topological space $(X,x)$,
$Sh^*((S^k,*),(X,x))=\check{\pi}_k^{*}(X,x)$, which makes it a Hausdorff
topological group. Moreover, we study some properties of these topological
coarse shape homotopoy groups such as second countability, movability and in
particullar, we prove that $\check{\pi}_k^{*^{top}}$ preserves finite product
of compact Hausdorff spaces. Also, we show that for a pointed topological space
$(X,x)$, $\check{\pi}_k^{top}(X,x)$ can be embedded in
$\check{\pi}_k^{*^{top}}(X,x)$.


title: Extended Object Tracking: Introduction, Overview and Applications

abstract:
  This article provides an elaborate overview of current research in extended
object tracking. We provide a clear definition of the extended object tracking
problem and discuss its delimitation to other types of object tracking. Next,
different aspects of extended object modelling are extensively discussed.
Subsequently, we give a tutorial introduction to two basic and well used
extended object tracking approaches - the random matrix approach and the Kalman
filter-based approach for star-convex shapes. The next part treats the tracking
of multiple extended objects and elaborates how the large number of feasible
association hypotheses can be tackled using both Random Finite Set (RFS) and
Non-RFS multi-object trackers. The article concludes with a summary of current
applications, where four example applications involving camera, X-band radar,
light detection and ranging (lidar), red-green-blue-depth (RGB-D) sensors are
highlighted.


title:
Deep Graphs - a general framework to represent and analyze heterogeneous
  complex systems across scales

abstract:
  Network theory has proven to be a powerful tool in describing and analyzing
systems by modelling the relations between their constituent objects. In recent
years great progress has been made by augmenting `traditional' network theory.
However, existing network representations still lack crucial features in order
to serve as a general data analysis tool. These include, most importantly, an
explicit association of information with possibly heterogeneous types of
objects and relations, and a conclusive representation of the properties of
groups of nodes as well as the interactions between such groups on different
scales. In this paper, we introduce a collection of definitions resulting in a
framework that, on the one hand, entails and unifies existing network
representations (e.g., network of networks, multilayer networks), and on the
other hand, generalizes and extends them by incorporating the above features.
To implement these features, we first specify the nodes and edges of a finite
graph as sets of properties. Second, the mathematical concept of partition
lattices is transferred to network theory in order to demonstrate how
partitioning the node and edge set of a graph into supernodes and superedges
allows to aggregate, compute and allocate information on and between arbitrary
groups of nodes. The derived partition lattice of a graph, which we denote by
deep graph, constitutes a concise, yet comprehensive representation that
enables the expression and analysis of heterogeneous properties, relations and
interactions on all scales of a complex system in a self-contained manner.
Furthermore, to be able to utilize existing network-based methods and models,
we derive different representations of multilayer networks from our framework
and demonstrate the advantages of our representation. We exemplify an
application of deep graphs using a real world dataset of precipitation
measurements.

categories: physics.data-an cs.SI physics.ao-ph physics.soc-ph


title:
On signatures of sonic wavepackets in time-resolved X-ray diffractometry
  of metal single crystals absorbing pulse from ultrafast laser

abstract:
  Copper (Cu), gold (Au) (111) crystals were illuminated with 120 fs pulses and
probed by 600 fs X-ray pulses. Rocking curves were measured versus 267 nm (UV)
pump- 0.154 nm probe delay time. Curve width broadening, peak diffracted
intensity and angular shift were recorded for the range of UV excitation
intensities of 2-8 mJ/cm2 . Observed oscillations in time delay dependences of
shift, width and of peak intensity of rocking curves are correlated, as
described by acoustic pulse bouncing between crystal surfaces. In (111) Au,
acoustic pulse originates from pump absorption layer, and peak intensity drops
by a factor of two (at delay time at which sonic wave reaches Au-substrate
boundary) of its initial value prior to absorption of laser pulse. In Cu,
correlated rocking curves dynamics is also observed, however buildup of rocking
curve broadening is faster than one can expect from sonic wavepacket
originating in pump absorption layer. This effect is attributed to acoustic
phonon generation outside of pump absorption layer, it is much stronger in Cu
than in Au. Phonon generation in Cu is distributed throughout the whole bulk of
crystal due to delocalization of mobile hot electrons diffusing from pump
absorption layer.


title:
Demonstration of single-shot picosecond time-resolved MeV electron
  imaging using a compact permanent magnet quadrupole based lens

abstract:
  We present the results of an experiment where a short focal length (~ 1.3 cm)
permanent magnet electron lens is used to image micron-size features of a metal
sample in a single shot, using an ultra- high brightness ps-long 4 MeV electron
beam from a radiofrequency photoinjector. Magnifcation ratios in excess of 30x
were obtained using a triplet of compact, small gap (3.5 mm), Halbach-style
permanent magnet quadrupoles with nearly 600 T/m field gradients. These results
pave the way to- wards single shot time-resolved electron microscopy and open
new opportunities in the applications of high brightness electron beams.


title:
Writer-independent Feature Learning for Offline Signature Verification
  using Deep Convolutional Neural Networks

abstract:
  Automatic Offline Handwritten Signature Verification has been researched over
the last few decades from several perspectives, using insights from graphology,
computer vision, signal processing, among others. In spite of the advancements
on the field, building classifiers that can separate between genuine signatures
and skilled forgeries (forgeries made targeting a particular signature) is
still hard. We propose approaching the problem from a feature learning
perspective. Our hypothesis is that, in the absence of a good model of the data
generation process, it is better to learn the features from data, instead of
using hand-crafted features that have no resemblance to the signature
generation process. To this end, we use Deep Convolutional Neural Networks to
learn features in a writer-independent format, and use this model to obtain a
feature representation on another set of users, where we train writer-dependent
classifiers. We tested our method in two datasets: GPDS-960 and Brazilian
PUC-PR. Our experimental results show that the features learned in a subset of
the users are discriminative for the other users, including across different
datasets, reaching close to the state-of-the-art in the GPDS dataset, and
improving the state-of-the-art in the Brazilian PUC-PR dataset.


title:
Combining Vision, Machine Learning and Automatic Control to Play the
  Labyrinth Game

abstract:
  The labyrinth game is a simple yet challenging platform, not only for humans
but also for control algorithms and systems. The game is easy to understand but
still very hard to master. From a system point of view, the ball behaviour is
in general easy to model but close to the obstacles there are severe
non-linearities. Additionally, the far from flat surface on which the ball
rolls provides for changing dynamics depending on the ball position. The
general dynamics of the system can easliy be handled by traditional automatic
control methods. Taking the obstacles and uneaven surface into accout would
require very detailed models of the system. A simple deterministic control
algorithm is combined with a learning control method. The simple control method
provides initial training data. As the learning method is trained, the system
can learn from the results of its own actions and the performance improves well
beyond the performance of the initial controller. A vision system and image
analysis is used to estimate the ball position while a combination of a PID
controller and a learning controller based on LWPR is used to learn to navigate
the ball through the maze.


title: From Big Data To Important Information

abstract:
  Advances in science are being sought in newly available opportunities to
collect massive quantities of data about complex systems. While key advances
are being made in detailed mapping of systems, how to relate this data to
solving many of the challenges facing humanity is unclear. The questions we
often wish to address require identifying the impact of interventions on the
system and that impact is not apparent in the detailed data that is available.
Here we review key concepts and motivate a general framework for building
larger scale views of complex systems and for characterizing the importance of
information in physical, biological and social systems. We provide examples of
its application to evolutionary biology with relevance to ecology,
biodiversity, pandemics, and human lifespan, and in the context of social
systems with relevance to ethnic violence, global food prices, and stock market
panic. Framing scientific inquiry as an effort to determine what is important
and unimportant is a means for advancing our understanding and addressing many
practical concerns, such as economic development or treating disease.

categories: physics.soc-ph nlin.AO q-bio.PE q-fin.EC


title:
Molecular Dynamics at Electrical- and Optical-Driven Phase Transitions
  Time-Resolved Infrared Studies Using Fourier-Transform Spectrometers

abstract:
  The time-dependent optical properties of molecular systems are investigated
by step-scan Fourier-transform spectroscopy in order to explore the dynamics at
phase transitions and molecular orientation in the milli- and microsecond
range. The electrical switching of liquid crystals traced by vibrational
spectroscopy reveals a rotation of the molecules with a relaxation time of 2
ms. The photo-induced neutral-ionic transition in TTF-CA takes place by a
suppression of the dimerization in the ionic phase and creation of neutral
domains. The time-dependent infrared spectra depend on temperature and laser
pulse intensity; the relaxation of the spectra follows a stretched-exponential
decay with relaxation times in the microsecond range strongly dependent on
temperature and laser intensity. We present all details of the experimental
setups and thoroughly discuss the technical challenges.


title:
Azimuthal asymmetry in the risetime of the surface detector signals of
  the Pierre Auger Observatory

abstract:
  The azimuthal asymmetry in the risetime of signals in Auger surface detector
stations is a source of information on shower development. The azimuthal
asymmetry is due to a combination of the longitudinal evolution of the shower
and geometrical effects related to the angles of incidence of the particles
into the detectors. The magnitude of the effect depends upon the zenith angle
and state of development of the shower and thus provides a novel observable,
$(\sec \theta)_\mathrm{max}$, sensitive to the mass composition of cosmic rays
above $3 \times 10^{18}$ eV. By comparing measurements with predictions from
shower simulations, we find for both of our adopted models of hadronic physics
(QGSJETII-04 and EPOS-LHC) an indication that the mean cosmic-ray mass
increases slowly with energy, as has been inferred from other studies. However,
the mass estimates are dependent on the shower model and on the range of
distance from the shower core selected. Thus the method has uncovered further
deficiencies in our understanding of shower modelling that must be resolved
before the mass composition can be inferred from $(\sec \theta)_\mathrm{max}$.


title:
Vibrationally-induced electronic population inversion with strong
  femtosecond pulses

abstract:
  We discover a new mechanism of electronic population inversion using strong
femtosecond pulses, where the transfer is mediated by vibrational motion on a
light-induced potential. The process can be achieved with a single pulse tuning
its frequency to the red of the Franck-Condon window. We show the determinant
role that the sign of the slope of the transition dipole moment can play on the
dynamics, and extend the method to multiphoton processes with odd number of
pulses. As an example, we show how the scheme can be applied to population
inversion in Na2.


title:
A Mathematical Trust Algebra for International Nation Relations
  Computation and Evaluation

abstract:
  This paper presents a trust computation for international relations and its
calculus, which related to Bayesian inference, Dempster Shafer theory and
subjective logic. We proposed a method that allows a trust computation which is
previously subjective and incomputable. An example of case study for the trust
computation is the United States of America Great Britain relations. The method
supports decision makers in a government such as foreign ministry, defense
ministry, presidential or prime minister office. The Department of Defense
(DoD) may use our method to determine a nation that can be known as a friendly,
neutral or hostile nation.


title: Revisiting Distributed Synchronous SGD

abstract:
  Distributed training of deep learning models on large-scale training data is
typically conducted with asynchronous stochastic optimization to maximize the
rate of updates, at the cost of additional noise introduced from asynchrony. In
contrast, the synchronous approach is often thought to be impractical due to
idle time wasted on waiting for straggling workers. We revisit these
conventional beliefs in this paper, and examine the weaknesses of both
approaches. We demonstrate that a third approach, synchronous optimization with
backup workers, can avoid asynchronous noise while mitigating for the worst
stragglers. Our approach is empirically validated and shown to converge faster
and to better test accuracies.


title:
Improving the understandability of the next edition of the International
  System of Units (SI) by focusing on its conceptual structure

abstract:
  The International System of Units (SI) is fundamental for the social, and not
only the scientific, role of metrology, and as such its understandability is a
crucial issue. According to the current draft of the new SI Brochure, the next
edition of the SI will be significantly more complex in its conceptual
structure than the previous ones. Identifying a strategy for effectively
communicating its main contents is then a worthwhile endeavor, in order to
increase the acceptance and thus the sustainability of the SI itself. Our
proposal is to focus on the semantic structure of the definitions: this is
instrumental to the awareness campaigns recommended by the General Conference
on Weights and Measures to make the next edition of the SI understandable by a
diverse readership without compromising scientific rigor.


title:
Phase diagram and thermal expansion measurements on the system of
  URu_{2-x}Fe_xSi_2

abstract:
  Thermal expansion, electrical resistivity, magnetization, and specific heat
measurements were performed on URu$_{2-x}$Fe$_{x}$Si$_{2}$ single crystals for
various values of the Fe concentration $x$ in both the hidden order (HO) and
large moment antiferromagnetic (LMAFM) regions of the phase diagram. Our
results show that the paramagnetic (PM) to HO and LMAFM phase transitions are
manifested differently in the thermal expansion coefficient. For Fe
concentrations near the boundary between the HO and LMAFM phases at $x_c$ ~
0.1, we observe two features in the thermal expansion upon cooling, one that
appears to be associated with the transition from the PM to the HO phase and
another one at lower temperature that may be due to the transition from the HO
to the LMAFM phase. These two features have not been observed in other
measurements such as specific heat or neutron scattering. In addition, the
uniaxial pressure derivative of the transition temperature, based on a
calculation using thermal expansion and specific heat data, changes
dramatically when crossing from the HO to the LMAFM phase.


title: Bolometric Flux Estimation for Cool Evolved Stars

abstract:
  Estimation of bolometric fluxes (F_BOL) is an essential component of stellar
effective temperature determination with optical and near-infrared
interferometry. Reliable estimation of F_BOL simply from broad-band K-band
photometry data is a useful tool in those cases were contemporaneous and/or
wide-range photometry is unavailable for a detailed spectral energy
distribution (SED) fit, as was demonstrated in Dyck et al. (1974).
Recalibrating the intrinsic F_BOL versus observed F_2.2um relationship of that
study with modern SED fitting routines, which incorporate the significantly
non-blackbody, empirical spectral templates of the INGS spectral library (an
update of the library in Pickles 1998) and estimation of reddening, serves to
greatly improve the accuracy and observational utility of this relationship. We
find that F_BOL values predicted are roughly 11% less than the corresponding
values predicted in Dyck et al. (1974), indicating the effects of SED
absorption features across bolometric flux curves.


title: The Einstein-Hilbert type action on foliated pseudo-Riemannian manifolds

abstract:
  We develop variation formulas on almost-product (e.g. foliated)
pseudo-Riemannian manifolds, and we consider variations of metric preserving
orthogonality of the distributions. These formulae are applied to
Einstein-Hilbert type actions: the total mixed scalar curvature and the total
extrinsic scalar curvature of a distribution. The obtained Euler-Lagrange
equations admit a number of solutions, e.g., twisted products, conformal
submersions and isoparametric foliations. The paper generalizes recent results
about the actions on codimension-one foliations for the case of arbitrary
(co)dimension.


title: Plasmons in QED Vacuum

abstract:
  The problem of longitudinal oscillations of an electric field and a charge
polarization density in QED vacuum is considered. Within the framework of
semiclassical analysis, we calculate time-periodic solutions of bosonized
(1+1)-dimensional QED (massive Schwinger model). Applying the Bohr--Sommerfeld
quantization condition, we determine the mass spectrum of charge-zero bound
states (plasmons) which correspond in quantum theory to the found classical
solutions. We show that the existence of such plasmons does not contradict any
fundamental physical laws and study qualitatively their excitation in
(3+1)-dimensional real world.


title:
From the universe to subsystems: Why quantum mechanics appears more
  stochastic than classical mechanics

abstract:
  By means of the examples of classical and Bohmian quantum mechanics, we
illustrate the well-known ideas of Boltzmann as to how one gets from laws
defined for the universe as a whole to dynamical relations describing the
evolution of subsystems. We explain how probabilities enter into this process,
what quantum and classical probabilities have in common and where exactly their
difference lies.


title:
Galaxy Populations in Massive Galaxy Clusters to z=1.1: Color
  Distribution, Concentration, Halo Occupation Number and Red Sequence Fraction

abstract:
  We study the galaxy populations in 74 Sunyaev Zeldovich Effect (SZE) selected
clusters from the South Pole Telescope (SPT) survey that have been imaged in
the science verification phase of the Dark Energy Survey (DES). The sample
extends up to $z\sim 1.1$ with $4 \times 10^{14} M_{\odot}\le M_{200}\le
3\times 10^{15} M_{\odot}$. Using the band containing the 4000~\AA\ break and
its redward neighbor, we study the color-magnitude distributions of cluster
galaxies to $\sim m_*+2$, finding: (1) the intrinsic rest frame $g-r$ color
width of the red sequence (RS) population is $\sim$0.03 out to $z\sim0.85$ with
a preference for an increase to $\sim0.07$ at $z=1$ and (2) the prominence of
the RS declines beyond $z\sim0.6$. The spatial distribution of cluster galaxies
is well described by the NFW profile out to $4R_{200}$ with a concentration of
$c_{\mathrm{g}} = 3.59^{+0.20}_{-0.18}$, $5.37^{+0.27}_{-0.24}$ and
$1.38^{+0.21}_{-0.19}$ for the full, the RS and the blue non-RS populations,
respectively, but with $\sim40$\% to 55\% cluster to cluster variation and no
statistically significant redshift or mass trends. The number of galaxies
within the virial region $N_{200}$ exhibits a mass trend indicating that the
number of galaxies per unit total mass is lower in the most massive clusters,
and shows no significant redshift trend. The red sequence (RS) fraction within
$R_{200}$ is $(68\pm3)$\% at $z=0.46$, varies from $\sim$55\% at $z=1$ to
$\sim$80\% at $z=0.1$, and exhibits intrinsic variation among clusters of
$\sim14$\%. We discuss a model that suggests the observed redshift trend in RS
fraction favors a transformation timescale for infalling field galaxies to
become RS galaxies of 2 to 3~Gyr.


title: Clustering Millions of Faces by Identity

abstract:
  In this work, we attempt to address the following problem: Given a large
number of unlabeled face images, cluster them into the individual identities
present in this data. We consider this a relevant problem in different
application scenarios ranging from social media to law enforcement. In
large-scale scenarios the number of faces in the collection can be of the order
of hundreds of million, while the number of clusters can range from a few
thousand to millions--leading to difficulties in terms of both run-time
complexity and evaluating clustering and per-cluster quality. An efficient and
effective Rank-Order clustering algorithm is developed to achieve the desired
scalability, and better clustering accuracy than other well-known algorithms
such as k-means and spectral clustering. We cluster up to 123 million face
images into over 10 million clusters, and analyze the results in terms of both
external cluster quality measures (known face labels) and internal cluster
quality measures (unknown face labels) and run-time. Our algorithm achieves an
F-measure of 0.87 on a benchmark unconstrained face dataset (LFW, consisting of
13K faces), and 0.27 on the largest dataset considered (13K images in LFW, plus
123M distractor images). Additionally, we present preliminary work on video
frame clustering (achieving 0.71 F-measure when clustering all frames in the
benchmark YouTube Faces dataset). A per-cluster quality measure is developed
which can be used to rank individual clusters and to automatically identify a
subset of good quality clusters for manual exploration.


title: Direct Visual Odometry using Bit-Planes

abstract:
  Feature descriptors, such as SIFT and ORB, are well-known for their
robustness to illumination changes, which has made them popular for
feature-based VSLAM\@. However, in degraded imaging conditions such as low
light, low texture, blur and specular reflections, feature extraction is often
unreliable. In contrast, direct VSLAM methods which estimate the camera pose by
minimizing the photometric error using raw pixel intensities are often more
robust to low textured environments and blur. Nonetheless, at the core of
direct VSLAM is the reliance on a consistent photometric appearance across
images, otherwise known as the brightness constancy assumption. Unfortunately,
brightness constancy seldom holds in real world applications.
  In this work, we overcome brightness constancy by incorporating feature
descriptors into a direct visual odometry framework. This combination results
in an efficient algorithm that combines the strength of both feature-based
algorithms and direct methods. Namely, we achieve robustness to arbitrary
photometric variations while operating in low-textured and poorly lit
environments. Our approach utilizes an efficient binary descriptor, which we
call Bit-Planes, and show how it can be used in the gradient-based optimization
required by direct methods. Moreover, we show that the squared Euclidean
distance between Bit-Planes is equivalent to the Hamming distance. Hence, the
descriptor may be used in least squares optimization without sacrificing its
photometric invariance. Finally, we present empirical results that demonstrate
the robustness of the approach in poorly lit underground environments.


title:
Theta-Quantization of the Orbital Angular Momentum Operator by means of
  Noncommutative Geometry

abstract:
  The eigenfunctions and eigenvalues of orbital angular momentum operator on
noncommutative lattice for a circle poset by theta-quantization are
constructed, and it is demonstrated that they are equivalent to those of the
conventional quantum mechanics.


title: Far-infrared-radio relation in cluster galaxies at intermediate redshift

abstract:
  The radio luminosities at 1.4 GHz is tightly correlated with the far-infrared
luminosities for various galaxy types (e.g. [16, 6, 2]) over a wide range of
redshift (see e.g. [5, 1, 15, 8, 7]). The relationship is widely believed to be
driven by the internal star formation activity. Radio emission from these
galaxies are predominantly produced from the synchrotron emission of cosmic-ray
electrons accelerated in supernova shocks. The infrared emission is due to
ultraviolet light from young massive stars that is absorbed and re-radiated by
dust [3]. A correlation is found also in local clusters but cluster galaxies
appears to have excess radio emission relative to the amount of far-infrared
emission [9, 13, 11]. In this work, we measure the far-infrared-radio
relationship in a massive cluster to test how this relationship changes at
intermediate z between the field and a high-density cluster environment.


title:
The 'Core' of Symmetric Homogeneous Polynomial Inequalities of Degree
  Four of Three Real Variables

abstract:
  In this paper we explore inequalities between symmetric homogeneous
polynomials of degree four of three real variables and three nonnegative real
variables. The main theorems describe the cases in which the smallest possible
coefficient is not expressed by the other coefficients. The problem is resolved
by introducing a parametric representation.


title:
Quorum sensing and remote synchronization in networks of Kuramoto
  oscillators: a biological interpretation

abstract:
  Non-linear oscillator networks have revealed properties as the remote
synchronization and the quorum sensing. The remote synchronization, defined as
the synchronization of nodes not directly connected by any sequence of
synchronized nodes, was found firstly in networks of amplitude oscillators and
recently in bipartite delayed networks of phase oscillators. The quorum
sensing, a biological information scheme discovered in cell aggregates, has
been investigated in amplitude oscillators coupled by a common medium.
Implications of such findings are important in technology and biology. We show
both of them in non-bipartite, biologically plausible networks of Kuramoto
oscillators. The quorum sensing emerges using the graph edge density, while the
remote synchronization is obtained by means of an oscillator acting as a
pacemaker. In the remote synchronization two distinct groups of well inter and
infra-synchronized nodes, separated by non-synchronized paths, appear clearly.
Our biological interpretation is that the remote synchronization, bypassing the
normal quorum sensing mechanism, is responsible of the pathological cell
proliferation. This approach seems suitable to study the quorum sensing
alterations due to genetic mutation or to the environmental action before the
actual mass replication begins.


title: Minimizers of anisotropic perimeters with cylindrical norms

abstract:
  We study various regularity properties of minimizers of the
$\Phi$--perimeter, where $\Phi$ is a norm. Under suitable assumptions on $\Phi$
and on the dimension of the ambient space, we prove that the boundary of a
cartesian minimizer is locally a Lipschitz graph out of a closed singular set
of small Hausdorff dimension. Moreover, we show the following anisotropic
Bernstein-type result: any entire cartesian minimizer is the subgraph of a
monotone function depending only on one variable.


title:
Some reversed and refined Callebaut inequalities via Kontorovich
  constant

abstract:
  In this paper we employ some operator techniques to establish some
refinements and reverses of the Callebaut inequality involving the geometric
mean and Hadamard product under some mild conditions. In particular, we show
  \begin{align*} K&\left(\frac{M^{2t-1}}{m^{2t-1}},2\right)^{r'}
\sum_{j=1}^n(A_j\sharp_{s}B_j)\circ \sum_{j=1}^n(A_j\sharp_{1-s}B_j)
\nonumber\\&\,\,+\left(\frac{t-s}{t-1/2}\right)\left(\sum_{j=1}^n(A_j\sharp_{t}B_j)\circ
\sum_{j=1}^n(A_j\sharp_{1-t}B_j) -\sum_{j=1}^n(A_j\sharp B_j)\circ
\sum_{j=1}^n(A_j\sharp B_j)\right)\nonumber \\&\leq
\sum_{j=1}^n(A_j\sharp_{t}B_j)\circ \sum_{j=1}^n(A_j\sharp_{1-t} B_j)\,,
\end{align*} where $A_j, B_j\in{\mathbb B}({\mathscr H})\,\,(1\leq j\leq n)$
are positive operators such that $0<m' \leq B_j\leq m <M \leq A_j\leq
M'\,\,(1\leq j\leq n)$, either $1\geq t\geq s>{\frac{1}{2}}$ or $0\leq t\leq
s<\frac{1}{2}$, $r'=\min\left\{\frac{t-s}{t-1/2},\frac{s-1/2}{t-1/2}\right\}$
and $K(t,2)=\frac{(t+1)^2}{4t}\,\,(t>0)$.


title: Progressive Temporal Window Widening

abstract:
  This paper introduces a scheme for data stream processing which is robust to
batch duration. Streaming frameworks process streams in batches retrieved at
fixed time intervals. In a common setting a pattern recognition algorithm is
applied independently to each batch. Choosing the right time interval is tough
--- a pattern may not fit in an interval which is too short, but detection will
be delayed and memory may be exhausted if the interval is too long. We propose
here Progressive Window Widening, an algorithm for increasing the interval
gradually so that patterns are caught at any pace without unnecessary delays or
memory overflow.
  This algorithm is relevant to computer security, system monitoring, user
behavior tracking, and other applications where patterns of unknown or varying
duration must be recognized online in data streams. Modern data stream
processing frameworks are ubiquitously used to process high volumes of data,
and adaptive memory and CPU allocation, facilitated by Progressive Window
Widening, is crucial for their performance.


title:
Comparison of associated Higgs boson-radion and Higgs boson pair
  production processes

abstract:
  Many models, in particular, the brane-world models with two branes, predict
the existence of the scalar radion, whose mass can be somewhat smaller than
those of all the Kaluza-Klein modes of the graviton and Standard Model (SM)
particles. Due to its origin the radion interacts with the trace of the
energy-momentum tensor of the SM. The fermion part of the radion interaction
Lagrangian is different from that for the SM Higgs boson due to the presence of
additional terms playing a role for off-shell fermions. It was shown previously
that for the case of the single radion and single Higgs boson production
processes in association with an arbitrary number of SM gauge bosons all the
contributions to the perturbative amplitudes appearing due to these additional
terms were cancelled out making the processes similar up to a replacement of
masses and overall coupling constants. For the case of the associated Higgs
boson-radion and the Higgs boson pair production processes involving the SM
gauge bosons the similarity property also takes place. However a detailed
consideration shows that in this case it is not enough to replace simply the
masses and the constants ($m_h \rightarrow m_r$ and $v \rightarrow \Lambda_r$).
One should also rescale the triple Higgs coupling by the factor $\xi \equiv 1 +
\frac{m_r^2 - m_h^2}{3m_h^2}$.


title: RGBD Datasets: Past, Present and Future

abstract:
  Since the launch of the Microsoft Kinect, scores of RGBD datasets have been
released. These have propelled advances in areas from reconstruction to gesture
recognition. In this paper we explore the field, reviewing datasets across
eight categories: semantics, object pose estimation, camera tracking, scene
reconstruction, object tracking, human actions, faces and identification. By
extracting relevant information in each category we help researchers to find
appropriate data for their needs, and we consider which datasets have succeeded
in driving computer vision forward and why.
  Finally, we examine the future of RGBD datasets. We identify key areas which
are currently underexplored, and suggest that future directions may include
synthetic data and dense reconstructions of static and dynamic scenes.


title:
Terminal Performance of Lead-Free Pistol Bullets in Ballistic Gelatin
  Using Retarding Force Analysis from High Speed Video

abstract:
  Due to concerns about environmental and industrial hazards of lead, a number
of military, law enforcement, and wildlife management agencies are giving
careful consideration to lead-free ammunition. The goal of lead-free bullets is
to gain the advantages of reduced lead use in the environment while maintaining
equal or better terminal performance. Accepting reduced terminal performance
would foolishly risk the lives of military and law enforcement personnel. This
paper uses the established technique of studying bullet impacts in ballistic
gelatin to characterize the terminal performance of eight commercial off-the-
shelf lead-free handgun bullets for comparison with earlier analysis of
jacketed lead bullets. Peak retarding force and energy deposit in calibrated
ballistic gelatin are quantified using high speed video. The temporary stretch
cavities and permanent wound cavities are also characterized. Two factors tend
to reduce the terminal performance of these lead-free projectiles compared to
similar jacketed lead designs. First, solid copper construction increase barrel
friction, which reduces muzzle velocity and energy, and thus reduces the
ability of the bullet to exert damaging forces in tissue simulant. Second, the
lower density of copper requires a longer bullet for a given mass and caliber,
which reduces remaining powder volume in the brass cartridge case, which also
tends to reduce muzzle velocity and energy. The results of the present study
are consistent with earlier analysis showing that expansion is necessary to
maximize the potential for rapid incapacitation of enemy combatants. In spite
of some new non-expanding nose designs that moderately increase forces between
bullet and tissue, the largest retarding forces and highest incapacitation
potential requires expanding bullets which maximize frontal area.


title: Testing General Free Functions in Preferred Scale Theories

abstract:
  Building on previous work, we explore the parameter space of general free
functions in non-relativistic modified gravity theories motivated by k-essence
and other scalar-tensor theories. Using a few proposed tests, we aim to update
Solar System based constraints on these ideas in line with previous theories
and suggest their utility in constraining modification to GR, potentially even
being able to test k-essence type theories.


title:
Anomalous fluctuations of nematic order in solutions of semiflexible
  polymers

abstract:
  The nematic ordering in semiflexible polymers with contour length $L$
exceeding their persistence length $\ell_p$ is described by a confinement of
the polymers in a cylinder of radius $r_{eff}$ much larger than the radius
$r_\rho$, expected from the respective concentration of the solution. Large
scale Molecular Dynamics simulations combined with Density Functional Theory
are used to locate the Isotropic-Nematic ($I-N$)-transition and to validate
this cylindrical confinement. Anomalous fluctuations, due to chain deflections
from neighboring chains in the nematic phase are proposed. Considering
deflections as collective excitations in the nematically ordered phase of
semiflexible polymers elucidates the origins of shortcomings in the description
of the $I-N$ transition by existing theories.


title: Heterotic Non-Abelian String of a Finite Length

abstract:
  We consider non-Abelian strings in N=2 supersymmetric QCD with the U$(N)$
gauge group and $N_f=N$ quark flavors deformed by a mass term for the adjoint
matter. This deformation breaks N=2 supersymmetry down to N=1. Dynamics of
orientational zero modes on the string world sheet are described then by
CP$(N-1)$ model with N=(0,2) supersymmetry. We study the string of a finite
length $L$ assuming compactification on a cylinder (periodic boundary
conditions). The world-sheet theory is solved in the large-$N$ approximation.
We find a rich phase structure in the $(L, \,u)$ plane where $u$ is a
deformation parameter. At large $L$ and intermediate $u$ we find a phase with
broken $Z_{2N}$ symmetry, $N$ vacua and a mass gap. At large values of $L$ and
$u$ still larger we have the $Z_{2N}$-symmetric phase with a single vacuum and
massless fermions. In both phases N=(0,2) supersymmetry is spontaneously
broken. We also observe a phase with broken SU$(N)\;$ symmetry at small $L$. In
the latter phase the mass gap vanishes and the vacuum energy is zero in the
leading $1/N$ approximation. However, we expect that $1/N$ corrections will
break N=(0,2) supersymmetry. We also discuss how this rich phase structure
matches the N=(2,2) limit in which the world-sheet theory has a single phase
with the mass gap independent of $L$.


title: Least square estimation of phase, frequency and PDEV

abstract:
  The Omega-preprocessing was introduced to improve phase noise rejection by
using a least square algorithm. The associated variance is the PVAR which is
more efficient than MVAR to separate the different noise types. However, unlike
AVAR and MVAR, the decimation of PVAR estimates for multi-tau analysis is not
possible if each counter measurement is a single scalar. This paper gives a
decimation rule based on two scalars, the processing blocks, for each
measurement. For the Omega-preprocessing, this implies the definition of an
output standard as well as hardware requirements for performing high-speed
computations of the blocks.


title: Reductive group actions

abstract:
  In this paper, we study rationality properties of reductive group actions
which are defined over an arbitrary field of characteristic zero. Thereby, we
unify Luna's theory of spherical systems and Borel-Tits' theory of reductive
groups. In particular, we define for any reductive group action a generalized
Tits index whose main constituents are a root system and a generalization of
the anisotropic kernel. The index controls to a large extent the behavior at
infinity (i.e., embeddings). For k-spherical varieties (i.e., where a minimal
parabolic has an open orbit) we obtain explicit (wonderful) completions of the
set of rational points. For local fields this means honest compactifications
generalizing the maximal Satake compactification of a symmetric space. Our main
tool is a k-version of the local structure theorem.


title:
Metal-insulator transition in disordered systems from the one-body
  density matrix

abstract:
  The insulating state of matter can be probed by means of a ground state
geometrical marker, which is closely related to the modern theory of
polarization (based on a Berry phase). In the present work we show that this
marker can be applied to determine the metal-insulator transition in disordered
systems. In particular, for non-interacting systems the geometrical marker can
be obtained from the configurational average of the norm-squared one-body
density matrix, which can be calculated within open as well as periodic
boundary conditions. This is in sharp contrast to a classification based on the
static conductivity, which is only sensible within periodic boundary
conditions. We exemplify the method by considering a simple lattice model,
known to have a metal-insulator transition as a function of the disorder
strength and demonstrate that the transition point can be obtained accurately
from the one-body density matrix. The approach has a general {\it ab-initio}
formulation and can be applied to realistic disordered materials by standard
electronic structure methods.


title: On period polynomials of degree $2^m$ for finite fields

abstract:
  We obtain explicit factorizations of reduced period polynomials of degree
$2^m$, $m\ge 4$, for finite fields of characteristic $p\equiv 3$ or
$5\pmod{8}$. This extends the results of G. Myerson, who considered the cases
$m=1$ and $m=2$, and S. Gurak, who studied the case $m=3$.


title: Diphoton excess and VV-scattering

abstract:
  We consider minimal effective interactions of the 750 GeV mass resonance
observed recently by ATLAS and CMS. Assuming a new scalar and gauge invariant
effective interactions leads to non-trivial two particle scattering amplitudes
with asymptotic gauge boson states. The longitudinally polarized $W\pm$ and $Z$
bosons interacting via dimension-five effective operators provide stringent
constraints on the validity of the effective model. The large width found by
ATLAS implying a bound of approximately 500 GeV already below the resonance,
turns this scenario unlikely. For production mainly in gluon fusion we get an
upper bound of $\sim 1.3$ TeV and strong limits on the masses of the underlying
vector-like fermions are given.


title: Two-dimensional Dirac fermions in YbMnBi2 antiferromagnet

abstract:
  We report two-dimensional quantum transport and Dirac fermions in YbMnBi2
single crystals. YbMnBi2 is a layered material with anisotropic conductivity
and magnetic order below 290 K. Magnetotransport properties, nonzero Berry
phase and small cyclotron mass indicate the presence of quasi two dimensional
Dirac fermions. Quantum oscillations in Hall resistivity suggest the presence
of both electron and hole parts of the Fermi surface whereas the Berry phase
suggests spin-orbit coupling.


title:
Magnus expansion approach to parametric oscillator systems in a thermal
  bath

abstract:
  We develop a Magnus formalism for periodically driven systems which provides
an expansion both in the driving term and the inverse driving frequency,
applicable to isolated and dissipative systems. We derive explicit formulas for
a driving term with a cosine dependence on time, up to fourth order. We apply
these to the steady state of a classical parametric oscillator coupled to a
thermal bath, which we solve numerically for comparison. Beyond dynamical
stabilization at second order, we find that the higher orders further
renormalize the oscillator frequency, and additionally create a weakly
renormalized effective temperature. The renormalized oscillator frequency is
quantitatively accurate almost up to the parametric instability, as we confirm
numerically. Additionally, a cut-off dependent term is generated, which
indicates the break-down of the hierarchy of time scales of the system, as a
precursor to the instability. Finally, we apply this formalism to a
parametrically driven chain, as an example for the control of the dispersion of
a many-body system.


title:
Non-degenerate 2-photon excitation in scattering medium for fluorescence
  microscopy

abstract:
  Non-degenerate 2-photon excitation (ND-2PE) of a fluorophore with two laser
beams of different photon energies offers an independent degree of freedom in
tuning of the photon flux for each beam. This feature takes advantage of the
infrared wavelengths used in 3-photon microscopy to achieve an increased
penetration depth, while preserving a relatively high degenerate 2-photon
excitation (D-2PE) cross section, exceeding that achievable with 3-photon
excitation. Here, using spatially and temporally aligned Ti:Sapphire laser and
optical parametric oscillator beams operating at near infrared (NIR) and
short-wavelength infrared (SWIR) optical frequencies, respectively, we provide
a practical demonstration that the emission intensity of a fluorophore excited
in the non-degenerate regime in a scattering medium is more efficient than the
commonly used D-2PE.


title: Stability of Thin-Shell Wormholes from Regular ABG Black Hole

abstract:
  In this paper, we construct thin-shell wormholes from regular Ayon-Beato and
Garcia black hole by employing cut and paste formalism and examine their
stability. We analyze attractive and repulsive characteristics of wormholes
corresponding to outward and inward-directed acceleration components,
respectively. A general equation of state is assumed as a linear perturbation
to explore stability of these constructed wormholes with and without
cosmological constant. We consider linear, logarithmic and Chaplygin gas models
for exotic matter and evaluate stability regions for different values of
charge. For horizon-free case, it is found that the generalized Chaplygin gas
model provides maximum stable regions in de Sitter background while the
modified generalized Chaplygin gas and logarithmic gas yield maximum stable
regions in anti-de Sitter spacetime.


title:
A new solution of embedding class I representing anisotropic fluid
  sphere in general relativity

abstract:
  In the present paper we are willing to model anisotropic star by choosing a
new grr metric potential. All the physical parameters like the matter density,
radial and transverse pressure and are regular inside the anisotropic star,
with the speed of sound less than the speed of light. So the new solution
obtained by us gives satisfactory description of realistic astrophysical
compact stars. The model of the present paper is compatible with observational
data of compact objects like RX J1856-37, Her X-1, Vela X-12 and Cen X-3. A
particular model of Her X-1 (Mass 0.98 times solar mass and radius=6.7 km.) is
studied in detail and found that it satisfies all the condition needed for
physically acceptable model. Our model is described analytically as well as
with the help of graphical representation.


title: The subpower membership problem for bands

abstract:
  Fix a finite semigroup $S$ and let $a_1,\ldots,a_k, b$ be tuples in a direct
power $S^n$. The subpower membership problem (SMP) for $S$ asks whether $b$ can
be generated by $a_1,\ldots,a_k$. For bands (idempotent semigroups), we provide
a dichotomy result: if a band $S$ belongs to a certain quasivariety, then
$SMP(S)$ is in P; otherwise it is NP-complete.
  Furthermore we determine the greatest variety of bands all of whose finite
members induce a tractable SMP. Finally we present the first example of two
finite algebras that generate the same variety and have tractable and
NP-complete SMPs, respectively.


title:
Infrared Divergence Separated for Stochastic Force - Langevin Evolution
  in the Inflationary Era

abstract:
  Inflation in the early Universe is a grand phase transition which have
produced the seeds of all the structures we now observe. We focus on the
non-equilibrium aspect of this phase transition especially the inevitable
infrared (IR) divergence associated to the the quantum and classical fields
during the inflation. There is a long history of research for removing this IR
divergence for healthy perturbation calculations. On the other hand, the same
IR divergence is quite relevant and have developed the primordial density
fluctuations in the early Universe. We develop a unified formalism in which the
IR divergence is clearly separated from the microscopic quantum field theory
but only appear in the statistical classical structure. We derive the classical
Langevin equation for the order parameter within the quantum field theory
through the instability of the de Sitter vacuum during the inflation. This
separation process is relevant in general to develop macroscopic structures and
to derive the basic properties of statistical mechanics in the quantum field
theory.


title: The Quantum Mechanics of Being and Its Manifestation

abstract:
  How can quantum mechanics be (i) the fundamental theoretical framework of
contemporary physics and (ii) a probability calculus that presupposes the
events to which, and on the basis of which, it assigns probabilities? The
question is answered without invoking knowledge or observers, by interpreting
the necessary distinction between two kinds of physical quantities -
unconditionally definite quantities and quantities that have values only if
they are measured - as a distinction between the manifested world and its
manifestation.


title:
Ferro-deformation and shape phase transitions over the nuclear chart: 50
  < protons (Z) < 82 and 50 < neutrons (N) < 126

abstract:
  We study a global nuclear structure in the framework of experimental
observables. With the aid of large nuclear structure data at the national
nuclear data center, NNDC, we present the distinctive systematic patterns
emerged in the first 2+ excited energies, E(2+) and their energy ratios to the
first 4+ levels, R = E(4+)/E(2+), in the even-even nuclei, over 50 < Z < 82 for
protons, and 50 < N < 126 for neutrons. We introduce the so-called pseudo-shell
configurations from the subshells mixture in order to explain a semi-double
shell closure, a shape phase transition, and a reinforced deformation. It is
found that the reinforced deformation arises when Z = 64 or 66 correlates with
N = 90 and reaches its maximum, indicating R = 3.3. Such a saturated reinforced
deformation spans over Z = 58 to 72 and N = 100 to 106 as showing its center at
Z = 64 or 66 and at N = 102 or 104. We define this reinforced deformation 'a
ferro-deformation' like a ferro-magnetism in condensed matter physics. The
shape coexistence would be expected to occur, such as a ferro-deformation, with
a strong rotational mode, and a near spherical shape, with a vibrational mode,
at the critical points of Z = 64 or 66, with N = 88 and 90; 150Sm and 152Sm,
152Gd and 154Gd, and 154Dy and 156Dy. We suggest that a super-deformation,
which can be formed at high-lying excited states in a moderate deformed
nucleus, would correspond to the ferro-deformation at N = 88 for the nuclei;
Sm, Gd, and Dy. We argue that the ferro-deformation can be closely associated
with a strong spin-orbital interaction between neutrons and protons in the
spin-orbit doublet, h9/2-h11/2, leading to the critical points at Z, N = 64,
104.


title: Birth and evolution of an optical vortex

abstract:
  When a phase singularity is suddenly imprinted on the axis of an ordinary
Gaussian beam, an optical vortex appears and starts to grow radially, by effect
of diffraction. This radial growth and the subsequent evolution of the optical
vortex under focusing or imaging can be well described in general within the
recently introduced theory of circular beams, which generalize the
hypergeometric-Gaussian beams and which obey novel kinds of ABCD rules. Here,
we investigate experimentally these vortex propagation phenomena and test the
validity of circular-beam theory. Moreover, we analyze the difference in radial
structure between the newly generated optical vortex and the vortex obtained in
the image plane, where perfect imaging would lead to complete closure of the
vortex core.


title: One-loop Matching and Running with Covariant Derivative Expansion

abstract:
  We develop tools for performing effective field theory (EFT) calculations in
a manifestly gauge-covariant fashion. We clarify how functional methods account
for one-loop diagrams resulting from the exchange of both heavy and light
fields, as some confusion has recently arisen in the literature. To efficiently
evaluate functional traces containing these "mixed" one-loop terms, we develop
a new covariant derivative expansion (CDE) technique that is capable of
evaluating a much wider class of traces than previous methods. The technique is
detailed in an appendix, so that it can be read independently from the rest of
this work. We review the well-known matching procedure to one-loop order with
functional methods. What we add to this story is showing how to isolate
one-loop terms coming from diagrams involving only heavy propagators from
diagrams with mixed heavy and light propagators. This is done using a non-local
effective action, which physically connects to the notion of "integrating out"
heavy fields. Lastly, we show how to use a CDE to do running analyses in EFTs,
\textit{i.e.} to obtain the anomalous dimension matrix. We demonstrate the
methodologies by several explicit example calculations.


title:
A Population of Short-Period Variable Quasars from PTF as Supermassive
  Black Hole Binary Candidates

abstract:
  Supermassive black hole binaries (SMBHBs) at sub-parsec separations should be
common in galactic nuclei, as a result of frequent galaxy mergers.
Hydrodynamical simulations of circumbinary discs predict strong periodic
modulation of the mass accretion rate on time-scales comparable to the orbital
period of the binary. As a result, SMBHBs may be recognized by the periodic
modulation of their brightness. We conducted a statistical search for periodic
variability in a sample of 35,383 spectroscopically confirmed quasars in the
photometric database of the Palomar Transient Factory (PTF). We analysed
Lomb-Scargle periodograms and assessed the significance of our findings by
modeling each individual quasar's variability as a damped random walk (DRW). We
identified 50 quasars with significant periodicity beyond the DRW model,
typically with short periods of a few hundred days. We find 33 of these to
remain significant after a re-analysis of their periodograms including
additional optical data from the intermediate-PTF and the Catalina Real-Time
Transient Survey (CRTS). Assuming that the observed periods correspond to the
redshifted orbital periods of SMBHBs, we conclude that our findings are
consistent with a population of unequal-mass SMBHBs, with a typical mass ratio
as low as q = M2/M1 ~ 0.01.


title: Ultraviolet Diversity of Type Ia Supernovae

abstract:
  Ultraviolet (UV) observations of Type Ia supernovae (SNe Ia) probe the
outermost layers of the explosion, and UV spectra of SNe Ia are expected to be
extremely sensitive to differences in progenitor composition and the details of
the explosion. Here we present the first study of a sample of high
signal-to-noise ratio SN Ia spectra that extend blueward of 2900 A. We focus on
spectra taken within 5 days of maximum brightness. Our sample of ten SNe Ia
spans the majority of the parameter space of SN Ia optical diversity. We find
that SNe Ia have significantly more diversity in the UV than in the optical,
with the spectral variance continuing to increase with decreasing wavelengths
until at least 1800 A (the limit of our data). The majority of the UV variance
correlates with optical light-curve shape, while there are no obvious and
unique correlations between spectral shape and either ejecta velocity or
host-galaxy morphology. Using light-curve shape as the primary variable, we
create a UV spectral model for SNe Ia at peak brightness. With the model, we
can examine how individual SNe vary relative to expectations based on only
their light-curve shape. Doing this, we confirm an excess of flux for SN 2011fe
at short wavelengths, consistent with its progenitor having a subsolar
metallicity. While most other SNe Ia do not show large deviations from the
model, ASASSN-14lp has a deficit of flux at short wavelengths, suggesting that
its progenitor was relatively metal rich.