title: Finite Spaces and Schemes

abstract:
  A ringed finite space is a ringed space whose underlying topological space is
finite. The category of ringed finite spaces contains, fully faithfully, the
category of finite topological spaces and the category of affine schemes. Any
ringed space, endowed with a finite open covering, produces a ringed finite
space. We introduce the notions of schematic finite space and schematic
morphism, showing that they behave, with respect to quasi-coherence, like
schemes and morphisms of schemes do. Finally, we construct a fully faithful and
essentially surjective functor from a localization of a full subcategory of the
category of schematic finite spaces and schematic morphisms to the category of
quasi-compact and quasi-separated schemes.


title: Reduced Google matrix

abstract:
  Using parallels with the quantum scattering theory, developed for processes
in nuclear and mesoscopic physics and quantum chaos, we construct a reduced
Google matrix $G_R$ which describes the properties and interactions of a
certain subset of selected nodes belonging to a much larger directed network.
The matrix $G_R$ takes into account effective interactions between subset nodes
by all their indirect links via the whole network. We argue that this approach
gives new possibilities to analyze effective interactions in a group of nodes
embedded in a large directed networks. Possible efficient numerical methods for
the practical computation of $G_R$ are also described.


title: On estimates of moduli of families of surfaces

abstract:
  A class of space mappings of finite distortion with $N$ and $N^{\,-1}$ Luzin
properties with respect to $k$-measured area is investigated. It is proved
that, mappings mentioned above satisfy upper and lower inequalities for
families of $k$-measures surfaces.


title: The problem of popular primes: Logjam

abstract:
  This paper will discuss the Logjam attack on TLS. The Logjam attack allows,
under certain conditions, to defeat the security provided by TLS. This is done
by manipulating server and client into using weak and deprecated export grade
crypto, and subsequently breaking the Diffie-Hellman key exchange. We explore
how the attack works conceptually and how exactly TLS is vulnerable to this
attack. Also, the conditions under which the attack can be mounted are
discussed, and an estimate of the impact of the attack is presented. Lastly,
several mitigations are presented.


title: Spectroscopy of ultracold neutrons using diffraction by a moving grating

abstract:
  Spectra of ultracold neutrons that appeared in experiments on neutron
diffraction by a moving grating were measured using the time-of-flight Fourier
spectrometer. Diffraction lines of five orders were observed simultaneously.
The obtained data are in good agreement with the theoretical predictions based
on the multiwave dynamical theory of neutron diffraction by a moving grating.


title:
Large-Dimensional Dynamic Factor Models: Estimation of Impulse-Response
  Functions with $I(1)$ Cointegrated Factors

abstract:
  We study a large-dimensional Dynamic Factor Model where: (i)~the vector of
factors $\mathbf F_t$ is $I(1)$ and driven by a number of shocks that is
smaller than the dimension of $\mathbf F_t$; and, (ii)~the idiosyncratic
components are either $I(1)$ or $I(0)$. Under~(i), the factors $\mathbf F_t$
are cointegrated and can be modeled as a Vector Error Correction Model (VECM).
Under (i) and (ii), we provide consistent estimators, as both the
cross-sectional size $n$ and the time dimension $T$ go to infinity, for the
factors, the loadings, the shocks, the coefficients of the VECM and therefore
the Impulse-Response Functions (IRF) of the observed variables to the
shocks.~Furthermore: possible deterministic linear trends are fully accounted
for, and the case of an unrestricted VAR in the levels $\mathbf F_t$, instead
of a VECM, is also studied. The finite-sample properties the proposed
estimators are explored by means of a MonteCarlo exercise. Finally, we revisit
two distinct and widely studied empirical applications. By correctly modeling
the long-run dynamics of the factors, our results partly overturn those
obtained by recent literature. Specifically, we find that: (i) oil price shocks
have just a temporary effect on US real activity; and, (ii) in response to a
positive news shock, the economy first experiences a significant boom, and then
a milder recession.


title:
Chains of compact cylinders for cusp-generic nearly integrable convex
  systems on $\mathbb{A}^3$

abstract:
  This paper is the first of a series of three dedicated to a proof of the
Arnold diffusion conjecture for perturbations of {convex} integrable
Hamiltonian systems on $\mathbb{A}^3=\mathbb{T}^3\times \mathbb{R}^3$.
  We consider systems of the form $H(\theta,r)=h(r)+f(\theta,r)$, where $h$ is
a $C^\kappa$ strictly convex and superlinear function on $\mathbb{R}^3$ and
$f\in C^\kappa(\mathbb{A}^3)$, $\kappa\geq2$. Given $e>\textrm{{Min}}\,h$ and a
finite family of arbitrary open sets $O_i$ in $\mathbb{R}^3$ intersecting
$h^{-1}(e)$, a diffusion orbit associated with these data is an orbit of $H$
which intersects each open set $\widehat O_i=\mathbb{T}^3\times
O_i\subset\mathbb{A}^3$.
  The first main result of this paper (Theorem I) states the existence (under
cusp-generic conditions on $f$ in Mather's terminology) of "chains of compact
and normally hyperbolic invariant $3$-dimensional cylinders" intersecting each
$\widehat O_i$. Diffusion orbits drifting along these chains are then proved to
exist in subsequent papers. The second main result (Theorem II) consists in a
precise description of the hyperbolic features of classical systems (sum of a
quadratic kinetic energy and a potential) on
$\mathbb{A}^2=\mathbb{T}^2\times\mathbb{R}^2$, which is a crucial step to prove
Theorem I.


title:
Asymmetries in $B \to K^\ast \ell^+ \ell^-$ Decays and Two Higgs Doublet
  Model

abstract:
  The study of polarized branching ratio and different lepton polarization
asymmeteries in the exclusive rare decays $B\rightarrow
K^{\ast}\ell^{+}\ell^{-}$ ($\ell=\mu , \tau$) have been made in the standard
model (SM) and in type III of the THDM. It has been found that the effects
arise from the THDM are quite promising in the longitudinal and transverse
polarized branching ratios $(\mathcal{B}_{L, T})$. Likewise, in case of $\mu$'s
as final state leptons, the polarized branching ratios have an order of
magnitude difference from their SM results. Similar trends have also been
observed both in the longitudinal and normal lepton polarization asymmetries
$P_{L, N}$ as well as their average values. We hope that the possible
signatures of these observables in $B\rightarrow K^{\ast}\ell^{+}\ell^{-}$
decays at different on going and future experiments will serve as a good tool
in the indirect searches of an extra Higgs boson doublet.


title:
Charge Exchange Induced X-ray Emission of Fe XXV and Fe XXVI via a
  Streamlined Model

abstract:
  Charge exchange is an important process for the modeling of X-ray spectra
obtained by the Chandra, XMM-Newton, and Suzaku X-ray observatories, as well as
the anticipated Astro-H mission. The understanding of the observed X-ray
spectra produced by many astrophysical environments is hindered by the current
incompleteness of available atomic and molecular data -- especially for charge
exchange. Here, we implement a streamlined program set that applies quantum
defect methods and the Landau-Zener theory to generate total, n-resolved, and
nlS-resolved cross sections for any given projectile ion/ target charge
exchange collision. Using this data in a cascade model for X-ray emission,
theoretical spectra for such systems can be predicted. With these techniques,
Fe25+ and Fe26+ charge exchange collisions with H, He, H2, N2, H2O, and CO are
studied for single electron capture. These systems have been selected as they
illustrate computational difficulties for high projectile charges. Further, Fe
XXV and Fe XXVI emission lines have been detected in the Galactic center and
Galactic ridge. Theoretical X-ray spectra for these collision systems are
compared to experimental data generated by an electron beam ion trap study.
Several l- distribution models have been tested for Fe25+ and Fe26+ single
electron capture. Such analysis suggests that commonly used l-distribution
models struggle to accurately reflect the true distribution of electron capture
as understood by more advanced theoretical methods.


title: Mechanical control of individual superconducting vortices

abstract:
  Manipulating individual vortices in a deterministic way is challenging,
ideally, manipulation should be effective, local, and tunable in strength and
location. Here, we show that vortices interact with strain fields generated by
mechanical stress. We utilized this interaction to move individual vortices in
thin superconducting films via local mechanical contact, without magnetic field
or current. We used a scanning superconducting quantum interference device
(SQUID) to image vortices and to apply local vertical stress with the tip of
our sensor. Vortices were attracted to the contact point, relocated, and were
stable at their new location. We show that vortices move only after contact and
that more effective manipulation is achieved with stronger force and longer
contact time. Mechanical manipulation of vortices provides a local view of the
interaction between strain and nanomagnetic objects as well as controllable,
effective, and reproducible manipulation technique.


title:
Arnold diffusion for cusp-generic nearly integrable convex systems on
  ${\mathbb A}^3$

abstract:
  We prove the existence of "Arnold diffusion orbits" in cusp-generic nearly
integrable a priori stable systems on ${\mathbb A}^3$. The result relies on the
cusp-generic existence of chains in nearly integrable a priori stable systems,
proved in a previous paper, together with the existence of diffusion orbits
along such chains. The latter result was obtained in collaboration with M.
Gidea.


title: Is a UCM fluid flow near a stationary point always singular?

abstract:
  Frequently observed divergence of numerical solutions to benchmark flows of
the UCM viscoelastic fluid is a known and widely discussed issue. Some authors
consider such singularities "invincible". The article argues this position, to
which end it considers two typical flows with a stagnation point, often a place
of the flows' singularity: counterflows and a flow spread over a wall. For the
counterflows numerical and asymptotic analytical solutions are presented. Both
kinds of flows turn out regular in the stagnation points, in particular, for
high Weissenberg numbers. A good accordance is demonstrated between the
analytical and numerical results.


title: Configurations of conjugate permutations

abstract:
  We describe some configurations of conjugate permutations which may be used
as a mathematical model of some genetical processes and crystal growth.


title: A decomposition theorem for {ISK4,wheel}-free trigraphs

abstract:
  An ISK4 in a graph G is an induced subgraph of G that is isomorphic to a
subdivision of K4 (the complete graph on four vertices). A wheel is a graph
that consists of a chordless cycle, together with a vertex that has at least
three neighbors in the cycle. A graph is {ISK4,wheel}-free if it has no ISK4
and does not contain a wheel as an induced subgraph. A "trigraph" is a
generalization of a graph in which some pairs of vertices have "undetermined"
adjacency. We prove a decomposition theorem for {ISK4,wheel}-free trigraphs.
Our proof closely follows the proof of a decomposition theorem for ISK4-free
graphs due to L\'ev\^eque, Maffray, and Trotignon (On graphs with no induced
subdivision of K4. J. Combin. Theory Ser. B, 102(4):924-947, 2012).


title:
Computing solutions to the congruence ${1^n + 2^n + \dotsb + n^n\equiv p
  \pmod{n}}$

abstract:
  It is well-known that the congruence $\sum_{i=1}^{ n} i^{ n} \equiv 1
\pmod{n}$ has exactly five solutions: $\{1,2,6,42,1806\}$. In this work, we
characterize the solutions to the congruence $1^n + 2^n + \dotsb + n^n\equiv p
\pmod{n}$ for every prime $p$. This characterization leads to an algorithm for
computing all such solutions, when there is a finite number of them. More
generally, our algorithm enables computing all the solutions below a much
higher bound as compared to what can be achieved by a naive exhaustive search.


title: Lasso Estimation of an Interval-Valued Multiple Regression Model

abstract:
  A multiple interval-valued linear regression model considering all the
cross-relationships between the mids and spreads of the intervals has been
introduced recently. A least-squares estimation of the regression parameters
has been carried out by transforming a quadratic optimization problem with
inequality constraints into a linear complementary problem and using Lemke's
algorithm to solve it. Due to the irrelevance of certain cross-relationships,
an alternative estimation process, the LASSO (Least Absolut Shrinkage and
Selection Operator), is developed. A comparative study showing the differences
between the proposed estimators is provided.


title: A mathematical formalization of data parallel operations

abstract:
  We give a mathematical formalization of `generalized data parallel'
operations, a concept that covers such common scientific kernels as
matrix-vector multiplication, multi-grid coarsening, load distribution, and
many more. We show that from a compact specification such computational aspects
as MPI messages or task dependencies can be automatically derived.


title: Exploring the Limits of Language Modeling

abstract:
  In this work we explore recent advances in Recurrent Neural Networks for
large scale Language Modeling, a task central to language understanding. We
extend current models to deal with two key challenges present in this task:
corpora and vocabulary sizes, and complex, long term structure of language. We
perform an exhaustive study on techniques such as character Convolutional
Neural Networks or Long-Short Term Memory, on the One Billion Word Benchmark.
Our best single model significantly improves state-of-the-art perplexity from
51.3 down to 30.0 (whilst reducing the number of parameters by a factor of 20),
while an ensemble of models sets a new record by improving perplexity from 41.0
down to 23.7. We also release these models for the NLP and ML community to
study and improve upon.


title: Quasi-periodic standing wave solutions of gravity-capillary water waves

abstract:
  We prove the existence and the linear stability of small amplitude time {\it
quasi-periodic} standing wave solutions (i.e. periodic and even in the space
variable $ x $) of a $ 2 $-dimensional ocean with infinite depth under the
action of gravity and surface tension. Such an existence result is obtained for
all the values of the surface tension belonging to a Borel set of
asymptotically full Lebesgue measure.


title:
The counting house: measuring those who count. Presence of
  Bibliometrics, Scientometrics, Informetrics, Webometrics and Altmetrics in
  the Google Scholar Citations, ResearcherID, ResearchGate, Mendeley & Twitter

abstract:
  Following in the footsteps of the model of scientific communication, which
has recently gone through a metamorphosis (from the Gutenberg galaxy to the Web
galaxy), a change in the model and methods of scientific evaluation is also
taking place. A set of new scientific tools are now providing a variety of
indicators which measure all actions and interactions among scientists in the
digital space, making new aspects of scientific communication emerge. In this
work we present a method for capturing the structure of an entire scientific
community (the Bibliometrics, Scientometrics, Informetrics, Webometrics, and
Altmetrics community) and the main agents that are part of it (scientists,
documents, and sources) through the lens of Google Scholar Citations.
  Additionally, we compare these author portraits to the ones offered by other
profile or social platforms currently used by academics (ResearcherID,
ResearchGate, Mendeley, and Twitter), in order to test their degree of use,
completeness, reliability, and the validity of the information they provide. A
sample of 814 authors (researchers in Bibliometrics with a public profile
created in Google Scholar Citations was subsequently searched in the other
platforms, collecting the main indicators computed by each of them. The data
collection was carried out on September, 2015. The Spearman correlation was
applied to these indicators (a total of 31) , and a Principal Component
Analysis was carried out in order to reveal the relationships among metrics and
platforms as well as the possible existence of metric clusters


title: Black Hole Based Tests of General Relativity

abstract:
  General relativity has passed all solar system experiments and neutron star
based tests, such as binary pulsar observations, with flying colors. A more
exotic arena for testing general relativity is in systems that contain one or
more black holes. Black holes are the most compact objects in the universe,
providing probes of the strongest-possible gravitational fields. We are
motivated to study strong-field gravity since many theories give large
deviations from general relativity only at large field strengths, while
recovering the weak-field behavior. In this article, we review how one can
probe general relativity and various alternative theories of gravity by using
electromagnetic waves from a black hole with an accretion disk, and
gravitational waves from black hole binaries. We first review model-independent
ways of testing gravity with electromagnetic/gravitational waves from a black
hole system. We then focus on selected examples of theories that extend general
relativity in rather simple ways. Some important characteristics of general
relativity include (but are not limited to) (i) only tensor gravitational
degrees of freedom, (ii) the graviton is massless, (iii) no quadratic or higher
curvatures in the action, and (iv) the theory is 4 dimensional. Altering a
characteristic leads to a different extension of general relativity: (i)
scalar-tensor theories, (ii) massive gravity theories, (iii) quadratic gravity,
and (iv) theories with large extra dimensions. Within each theory, we describe
black hole solutions, their properties, and current and projected constraints
on each theory using black hole-based tests of gravity. We close this review by
listing some of the open problems in model-independent tests and within each
specific theory.


title: The Science Case for ALMA Band 2 and Band 2+3

abstract:
  We discuss the science drivers for ALMA Band 2 which spans the frequency
range from 67 to 90 GHz. The key science in this frequency range are the study
of the deuterated molecules in cold, dense, quiescent gas and the study of
redshifted emission from galaxies in CO and other species. However, Band 2 has
a range of other applications which are also presented. The science enabled by
a single receiver system which would combine ALMA Bands 2 and 3 covering the
frequency range 67 to 116 GHz, as well as the possible doubling of the IF
bandwidth of ALMA to 16 GHz, are also considered.

categories: astro-ph.IM astro-ph.CO astro-ph.GA astro-ph.SR


title:
On Cartesian line sampling with anisotropic total variation
  regularization

abstract:
  This paper considers the use of the anisotropic total variation seminorm to
recover a two dimensional vector $x\in \mathbb{C}^{N\times N}$ from its partial
Fourier coefficients, sampled along Cartesian lines. We prove that if $(x_{k,j}
- x_{k-1,j})_{k,j}$ has at most $s_1$ nonzero coefficients in each column and
$(x_{k,j} - x_{k,j-1})_{k,j}$ has at most $s_2$ nonzero coefficients in each
row, then, up to multiplication by $\log$ factors, one can exactly recover $x$
by sampling along $s_1$ horizontal lines of its Fourier coefficients and along
$s_2$ vertical lines of its Fourier coefficients. Finally, unlike standard
compressed sensing estimates, the $\log$ factors involved are dependent on the
separation distance between the nonzero entries in each row/column of the
gradient of $x$ and not on $N^2$, the ambient dimension of $x$.


title: Godel's Second Incompleteness Theorem for Definable Theories

abstract:
  It is proved that if $T$ is a $\Sigma_{n+1}$ Definable theory which is
$\Sigma_n$-sound and extends $PA$, then $T$ can not prove the sentence
$\Sigma_n-sound(T)$ that expresses the $\Sigma_n$-soundness of $T$. Optimality
of this result is showed by constructing a $\Sigma_{n+1}$-definable and
$\Sigma_{n-1}$-sound theory extending $PA$ such that $\Sigma_n-sound(T)$ is
$T$-provable. It is also proved that no R.E. arithmetical theory, evevn very
weak theories which are not $\Sigma_1$-complete, can prove $\Sigma_1$-soundness
of itself.


title:
Phonon lasing as a likely mechanism for density-dependent velocity
  saturation in GaN transistors

abstract:
  We show that density-dependent velocity saturation in a GaN High Electron
Mobility Transistor (HEMT) can be related to the stimulated emission of
longitudinal optical (LO) phonons. As the drift velocity of electrons
increases, the drift of the Fermi distribution in reciprocal space produces
population inversion and gain for the LO phonons. Once this gain reaches a
threshold value, the avalanche-like increase of LO emission causes a rapid loss
of electron energy and momentum and leads to drift velocity saturation. Our
simple model correctly predicts both the general trend of the saturation
velocity decreasing with increasing electron density and the values of
saturation velocity measured in our experiments.


title:
A black hole solution of higher-dimensional Weyl-Yang-Kaluza-Klein
  theory

abstract:
  We consider the Weyl$-$Yang gauge theory of gravitation in a
$(4+3)$-dimensional curved space-time within the scenario of the non-Abelian
Kaluza$-$Klein theory for the source and torsion-free limits. The explicit
forms of the field equations containing a new spin current term and the
energy-momentum tensors in the usual four dimensions are obtained through the
well-known dimensional reduction procedure. In this limit, these field
equations admit (anti-)dyon and magnetic (anti-)monopole solutions as well as
non-Einsteinian solutions in the presence of a generalized Wu$-$Yang ansatz and
some specific warping functions when the extra dimensions associated with the
round and squashed three-sphere $S^{3}$ are, respectively, included. The
(anti-)dyonic solution has similar properties to those of the
Reissner$-$Nordstr\"{o}m$-$de Sitter black holes of the Einstein$-$Yang$-$Mills
system. However, the cosmological constant naturally appears in this approach,
and it associates with the constant warping function as well as the
three-sphere radius. It is demonstrated that not only the squashing parameter
$\ell$ behaves as the constant charge but also its sign can determine whether
the solution is a dyon/monopole or an antidyon/antimonopole. It is also shown
by using the power series method that the existence of nonconstant warping
function is essential for finding new exact Schwarzschild-like solutions in the
considered model.


title:
A generalized Debye-Peierls/Allen-Feldman model for the lattice thermal
  conductivity of low dimensional and disordered materials

abstract:
  We present a generalized model to describe the lattice thermal conductivity
of low-dimensional (low-D) and disordered systems. The model is a
straightforward generalization of the Debye-Peierls and Allen-Feldman schemes
to arbitrary dimensions, accounting for low-D effects such as differences in
dispersion, density of states, and scattering. Similar in spirit to the
Allen-Feldman approach, heat carriers are categorized according to their
transporting capacity as propagons, diffusons, and locons. The results of the
generalized model are compared to experimental results when available, and
equilibrium molecular dynamics simulations otherwise. The results are in very
good agreement with our analysis of phonon localization in disordered low-D
systems, such as amorphous graphene and glassy diamond nanothreads. Several
unique aspects of thermal transport in low-D and disordered systems, such as
milder suppression of thermal conductivity and negligble diffuson
contributions, are captured by the approach.


title: On-site Atractive Multiorbital Hamiltonian for $d$-Wave Superconductors

abstract:
  We introduce a two-orbital Hamiltonian on a square lattice that contains
on-site attractive interactions involving the two $e_g$ orbitals. Via a
canonical mean-field procedure similar to the one applied to the well-known
negative-$U$ Hubbard model, it is shown that the new model develops $d$-wave
($B_{1g}$) superconductivity with nodes along the diagonal directions of the
square Brillouin zone. This result is also supported by exact diagonalization
of the model in a small cluster. The expectation is that this relatively simple
attractive model could be used to address the properties of multiorbital
$d$-wave superconductors in the same manner that the negative-$U$ Hubbard model
is widely applied to the study of the properties of $s$-wave single-orbital
superconductors. In particular, we show that by splitting the $e_g$ orbitals
and working at three-quarters filling, such that the $x^2-y^2$ orbital
dominates at the Fermi level but the $3z^2-r^2$ orbital contribution is
nonzero, the $d$-wave pairing state found here phenomenologically reproduces
several properties of the superconducting state of the high $T_c$ cuprates.


title: Super-renormalizable or Finite Lee-Wick Quantum Gravity

abstract:
  We propose a class of multidimensional higher derivative theories of gravity
without extra real degrees of freedom besides the graviton field. The
propagator shows up the usual real graviton pole and extra complex conjugates
poles that do not contribute to the absorptive part of the physical scattering
amplitudes. Indeed, they may consistently be excluded from the asymptotic
observable states of the theory making use of the Lee-Wick and Cutkoski,
Landshoff, Olive and Polkinghorne prescription for the construction of a
unitary S-matrix. Therefore, the spectrum consists on the graviton and short
lived elementary unstable particles that we named "anti-gravitons" because of
their repulsive contribution to the gravitational potential at short distance.
However, another interpretation of the complex conjugate pairs is proposed
based on the Calmet's suggestion, i.e. they could be understood as black hole
precursors long established in the classical theory. Since the theory is CPT
invariant, the complex conjugate of the micro black hole precursor has received
as a white hole precursor consistently with the t'Hooft complementary
principle. It is proved that the quantum theory is super-renormalizable in even
dimension, i.e. only a finite number of divergent diagrams survive, and finite
in odd dimension. Furthermore, turning on a local potential of the Riemann
tensor we can make the theory finite in any dimension. The singularity-free
Newtonian gravitational potential is explicitly computed for a range of higher
derivative theories. Finally, we propose a new super-reneromalizable or finite
Lee-Wick standard model of particle physics.


title: Approximate Capacity of Index Coding for Some Classes of Graphs

abstract:
  For a class of graphs for which the Ramsey number $R(i,j)$ is upper bounded
by $ci^aj^b$, for some constants $a,b,$ and $c$, it is shown that the clique
covering scheme approximates the broadcast rate of every $n$-node index coding
problem in the class within a multiplicative factor of $c^{\frac{1}{a+b+1}}
n^{\frac{a+b}{a+b+1}}$ for every $n$. Using this theorem and some graph
theoretic arguments, it is demonstrated that the broadcast rate of planar
graphs, line graphs and fuzzy circular interval graphs is approximated by the
clique covering scheme within a factor of $n^{\frac{2}{3}}$.


title: Catch bond mechanism in Dynein motor driven collective transport

abstract:
  Recent experiments have demonstrated that dynein motor exhibits catch bonding
behaviour, in which the unbinding rate of a single dynein decreases with
increasing force, for a certain range of force. Motivated by these experiments,
we propose a model for catch bonding in dynein using a threshold force bond
deformation (TFBD) model wherein catch bonding sets in beyond a critical
applied load force. We study the effect of catch bonding on unidirectional
transport properties of cellular cargo carried by multiple dynein motors within
the framework of this model. We find catch bonding can result in dramatic
changes in the transport properties, which are in sharp contrast to kinesin
driven unidirectional transport, where catch bonding is absent. We predict
that, under certain conditions, the average velocity of the cellular cargo can
actually increase as applied load is increased. We characterize the transport
properties in terms of a velocity profile phase plot in the parameter space of
the catch bond strength and the stall force of the motor. This phase plot
yields predictions that may be experimentally accessed by suitable
modifications of motor transport and binding properties. Our work necessitates
a reexamination of existing theories of collective bidirectional transport of
cellular cargo where the catch bond effect of dynein described in this paper is
expected to play a crucial role.


title:
Twisted partial actions and extensions of semilattices of groups by
  groups

abstract:
  We introduce the concept of an extension of a semilattice of groups $A$ by a
group $G$ and describe all the extensions of this type which are equivalent to
the crossed products $A*_\Theta G$ by twisted partial actions $\Theta$ of $G$
on $A$. As a consequence, we establish a one-to-one correspondence, up to an
isomorphism, between twisted partial actions of groups on semilattices of
groups and so-called Sieben twisted modules over $E$-unitary inverse
semigroups.


title:
Notes on photonic topological insulators and scattering-protected edge
  states - a brief introduction

abstract:
  The topic of photonic topological insulators and scattering-protected edge
states bridges concepts from condensed matter physics and electromagnetics, and
necessitates understanding the Berry potential and related concepts. These
notes are an attempt at a moderately self-contained introduction to the topic,
including two detailed photonic examples drawn from the literature. We made
these notes in the process of trying to understand this topic ourselves, and we
are posting this material in the spirit of helping other researchers start to
understand this material. We claim no novelty in the material or its
presentation.


title: Human Atlas: A Tool for Mapping Social Networks

abstract:
  Most social network analyses focus on online social networks. While these
networks encode important aspects of our lives they fail to capture many
real-world connections. Most of these connections are, in fact, public and
known to the members of the community. Mapping them is a task very suitable for
crowdsourcing: it is easily broken down in many simple and independent
subtasks. Due to the nature of social networks -- presence of highly connected
nodes and tightly knit groups -- if we allow users to map their immediate
connections and the connections between them, we will need few participants to
map most connections within a community. To this end, we built the Human Atlas,
a web-based tool for mapping social networks. To test it, we partially mapped
the social network of the MIT Media Lab. We ran a user study and invited
members of the community to use the tool. In 4.6 man-hours, 22 participants
mapped 984 connections within the lab, demonstrating the potential of the tool.


title:
Rarefaction Waves of the Korteweg-de Vries Equation via Nonlinear
  Steepest Descent

abstract:
  We apply the method of nonlinear steepest descent to compute the long-time
asymptotics of the Korteweg-de Vries equation with steplike initial data
leading to a rarefaction wave. In addition to the leading asymptotic we also
compute the next term in the asymptotic expansion of the rarefaction wave,
which was not known before.


title: The Hairer--Quastel universality result in equilibrium

abstract:
  We use the notion of energy solutions of the stochastic Burgers equation to
give a short proof of the Hairer-Quastel universality result for a class of
stationary weakly asymmetric stochastic PDEs.


title: A note on the Akemann-Doner and Farah-Wofsey constructions

abstract:
  We remove the assumption of the continuum hypothesis from the Akemann-Doner
construction of a non-separable $C^*$-algebra $A$ with only separable
commutative $C^*$-subalgebras. We also extend a result of Farah and Wofsey's,
constructing $\aleph_1$ commuting projections in the Calkin algebra with no
commutative lifting. This removes the assumption of the continuum hypothesis
from a version of a result of Anderson. Both results are based on Luzin's
almost disjoint family construction.


title: On uniformly bounded orthonormal Sidon systems

abstract:
  In answer to a question raised recently by Bourgain and Lewko, we show, with
their paper's terminology, that any uniformly bounded $\psi_2 (C)$-orthonormal
system ($\psi_2 (C)$ is a variant of subGaussian)is 2-fold tensor Sidon. This
sharpens their result that it is 5-fold tensor Sidon. The proof is somewhat
reminiscent of the author's original one for (Abelian) group characters, based
on ideas due to Drury and Rider. However, we use Talagrand's majorizing measure
theorem in place of Fernique's metric entropy lower bound. We also show that a
uniformly bounded orthonormal system is randomly Sidon iff it is 4-fold tensor
Sidon, or equivalently $k$-fold tensor Sidon for some (or all) $k\ge 4$.
Various generalizations are presented, including the case of random matrices,
for systems analogous to the Peter-Weyl decomposition for compact non-Abelian
groups. In the latter setting we also include a new proof of Rider's
unpublished result that randomly Sidon sets are Sidon, which implies that the
union of two Sidon sets is Sidon.


title: Tame graphs, clutters and their Rees algebras

abstract:
  A tame ideal is an ideal $I$ such that the blowup of the affine space
$\mathbb{A}_k^n$ along $I$ is regular. In this paper, we give a combinatorial
characterization of tame squarefree monomial ideals. More precisely, we show
that a square free monomial ideal is tame if and only if the corresponding
clutter is a union of some isolated vertices and a complete $d$-partite
$d$-uniform clutter. It turns out that a squarefree monomial ideal is tame, if
and only if the facets of its Stanley-Reisner complex have mutually disjoint
complements. Also, we characterize all monomial ideals generated in degree at
most 2 which are tame. Finally, we prove that tame squarefree ideals are of
fiber type.


title:
A Finitely presented group whose word problem has sampleable hard
  instances

abstract:
  Hard instances of natural computational problems are often elusive. In this
note we present an example of a natural decision problem, the word problem for
a certain finitely presented group, whose hard instances are easy to find. More
precisely the problem has a complexity core sampleable in linear time.


title: QCD sum rule study of hidden-charm pentaquarks

abstract:
  We study the mass spectra of hidden-charm pentaquarks having spin $J =
{1\over2}/{3\over2}/{5\over2}$ and quark contents $uud c \bar c$. We
systematically construct all the relevant local hidden-charm pentaquark
currents, and select some of them to perform QCD sum rule analyses. We find
that the $P_c(4380)$ and $P_c(4450)$ can be identified as hidden-charm
pentaquark states composed of an anti-charmed meson and a charmed baryon.
Besides them, we also find a) the lowest-lying hidden-charm pentaquark state of
$J^P = 1/2^-$ has the mass $4.33^{+0.17}_{-0.13}$ GeV, while the one of $J^P =
1/2^+$ is significantly higher, that is around $4.7-4.9$ GeV; b) the
lowest-lying hidden-charm pentaquark state of $J^P = 3/2^-$ has the mass
$4.37^{+0.18}_{-0.13}$ GeV, consistent with the $P_c(4380)$ of $J^P = 3/2^-$,
while the one of $J^P = 3/2^+$ is also significantly higher, that is above
$4.6$ GeV; c) the hidden-charm pentaquark state of $J^P = 5/2^-$ has a mass
around $4.5-4.6$ GeV, slightly larger than the $P_c(4450)$ of $J^P = 5/2^+$.


title:
Screen Content Image Segmentation Using Sparse Decomposition and Total
  Variation Minimization

abstract:
  Sparse decomposition has been widely used for different applications, such as
source separation, image classification, image denoising and more. This paper
presents a new algorithm for segmentation of an image into background and
foreground text and graphics using sparse decomposition and total variation
minimization. The proposed method is designed based on the assumption that the
background part of the image is smoothly varying and can be represented by a
linear combination of a few smoothly varying basis functions, while the
foreground text and graphics can be modeled with a sparse component overlaid on
the smooth background. The background and foreground are separated using a
sparse decomposition framework regularized with a few suitable regularization
terms which promotes the sparsity and connectivity of foreground pixels. This
algorithm has been tested on a dataset of images extracted from HEVC standard
test sequences for screen content coding, and is shown to have superior
performance over some prior methods, including least absolute deviation
fitting, k-means clustering based segmentation in DjVu and shape primitive
extraction and coding (SPEC) algorithm.


title:
A Multi-Resolution Spatio-Temporal Model for Brain Activation and
  Connectivity in fMRI Data

abstract:
  Functional Magnetic Resonance Imaging (fMRI) is a primary modality for
studying brain activity. Modeling spatial dependence of imaging data at
different scales is one of the main challenges of contemporary neuroimaging,
and it could allow for accurate testing for significance in neural activity.
The high dimensionality of this type of data (on the order of hundreds of
thousands of voxels) poses serious modeling challenges and considerable
computational constraints. For the sake of feasibility, standard models
typically reduce dimensionality by modeling covariance among regions of
interest (ROIs) -- coarser or larger spatial units -- rather than among voxels.
However, ignoring spatial dependence at different scales could drastically
reduce our ability to detect activation patterns in the brain and hence produce
misleading results. To overcome these problems, we introduce a multi-resolution
spatio-temporal model and a computationally efficient methodology to estimate
cognitive control related activation and whole-brain connectivity. The proposed
model allows for testing voxel-specific activation while accounting for
non-stationary local spatial dependence within anatomically defined ROIs, as
well as regional dependence (between-ROIs). Furthermore, the model allows for
detection of interpretable connectivity patterns among ROIs using the graphical
Least Absolute Shrinkage Selection Operator (LASSO). The model is used in a
motor-task fMRI study to investigate brain activation and connectivity patterns
aimed at identifying associations between these patterns and regaining motor
functionality following a stroke.


title:
Equivariant Hirzebruch classes and Molien series of quotient
  singularities

abstract:
  We study properties of the Hirzebruch class of quotient singularities
$\mathbb{C}^n/G$, where $G$ is a finite matrix group. The main result states
that the Hirzebruch class coincides with the Molien series of $G$ under
suitable substitution of variables. The Hirzebruch class of a crepant
resolution can be described specializing the orbifold elliptic genus
constructed by Borisov and Libgober. It is equal to the combination of Molien
series of centralizers of elements of $G$. This is an incarnation of the McKay
correspondence. The results are illustrated with several examples, in
particular of 4-dimensional symplectic quotient singularities.


title: Classification of blow-up limits for the sinh-Gordon equation

abstract:
  The aim of this paper is to use a selection process and a careful study of
the interaction of bubbling solutions to show a classification result for the
blow-up values of the elliptic sinh-Gordon equation $$\Delta
u+h_1e^u-h_2e^{-u}=0 \quad \mathrm{in}~B_1\subset\mathbb{R}^2.$$ In particular
we get that the blow-up values are multiple of $8\pi.$ It generalizes the
result of Jost, Wang, Ye and Zhou \cite{jwyz} where the extra assumption $h_1 =
h_2$ is crucially used.


title:
Bosonic integer quantum Hall states in topological bands with Chern
  number two

abstract:
  We study the interacting bosons in topological Hofstadter bands with Chern
number two. Using exact diagonalization, we demonstrate that bosonic integer
quantum Hall (BIQH) state emerges at integer boson filling factor $\nu=1$ of
the lowest Chern band with evidences including a robust spectrum gap and
quantized topological Hall conductance two. Moreover, the robustness of BIQH
state against different interactions and next-nearest neighbor hopping is
investigated. The strong nearest neighbor interaction would favor a charge
density wave. When the onsite interaction decreases, BIQH state undergoes a
continuous transition into a superfluid state. Without next-nearest neighbor
hopping, the ground state is possibly in a metallic Fermi-liquid-like phase.


title: Dynamic Matching and Allocation of Tasks

abstract:
  In many two-sided markets, the parties to be matched have incomplete
information about their characteristics. We consider the settings where the
parties engaged are extremely patient and are interested in long-term
partnerships. Hence, once the final matches are determined, they persist for a
long time. Each side has an opportunity to learn (some) relevant information
about the other before final matches are made. For instance, clients seeking
workers to perform tasks often conduct interviews that require the workers to
perform some tasks and thereby provide information to both sides. The
performance of a worker in such an interview- and hence the information
revealed - depends both on the inherent characteristics of the worker and the
task and also on the actions taken by the worker (e.g. the effort expended),
which are not observed by the client. Thus there is moral hazard. Our goal is
to derive a dynamic matching mechanism that facilitates learning on both sides
before final matches are achieved and ensures that the worker side does not
have incentive to obscure learning of their characteristics through their
actions. We derive such a mechanism that leads to final matching that achieve
optimal performance (revenue) in equilibrium. We show that the equilibrium
strategy is long-run coalitionally stable, which means there is no subset of
workers and clients that can gain by deviating from the equilibrium strategy.
We derive all the results under the modeling assumption that the utilities of
the agents are defined as limit of means of the utility obtained in each
interaction.


title: On the least square-free primitive root modulo $p$

abstract:
  Let $g^{\square}(p)$ denote the least square-free primitive root modulo $p$.
We show that $g^{\square}(p)< p^{0.96}$ for all $p$.


title: Flag-dipole and flagpole spinors fluid flows in Kerr spacetimes

abstract:
  Flagpole and flag-dipole spinors are particular classes of spinor fields that
has been recently used in different branches of theoretical physics. In this
paper, we study the possibility and consequences of these spinor fields to
induce an underlying fluid flow structure in the background of Kerr spacetimes.
We show that flag-dipole spinor fields are solutions of the equations of motion
in this context. To our knowledge, this is the second time that this class of
spinor field appears as a physical solution, the first one occurring as a
solution of the Dirac equation in ESK gravities.


title: A Simple Practical Accelerated Method for Finite Sums

abstract:
  We describe a novel optimization method for finite sums (such as empirical
risk minimization problems) building on the recently introduced SAGA method.
Our method achieves an accelerated convergence rate on strongly convex smooth
problems. Our method has only one parameter (a step size), and is radically
simpler than other accelerated methods for finite sums. Additionally it can be
applied when the terms are non-smooth, yielding a method applicable in many
areas where operator splitting methods would traditionally be applied.


title:
Energy and Spectral Efficiency Gains From Multi-User MIMO-based Small
  Cell Reassignments

abstract:
  In this work we investigate the reassignment of User Equipments (UEs) between
adjacent small cells to concurrently enable spatial multiplexing gains through
Multi-User MIMO (MU-MIMO) and reductions in energy consumption though switching
emptied small cells to a sleep state. We consider a case where UEs can be
reassigned between adjacent small cells provided that the targeted neighbouring
cell contains a UE with which the reassigned UE can perform MU-MIMO without
experiencing excessive multi-user interference, and whilst achieving a minimum
expected gain in spectral efficiency over the previous original cell
transmissions as a result. We formulate the selection decision of which UEs to
reassign as a set covering problem with the objective of maximising the number
of small cell base stations to switch to a sleep state. Our results show that,
for both indoor and outdoor LTE small cell scenarios, the proposed
MU-MIMO-based reassignments achieve significant reductions in the required
number of active small cell base stations, whilst simultaneously achieving
increases in spectral efficiency.


title:
Binary Black Hole Mergers from Globular Clusters: Masses, Merger Rates,
  and the Impact of Stellar Evolution

abstract:
  The recent discovery of GW150914, the binary black hole merger detected by
Advanced LIGO, has the potential to revolutionize observational astrophysics.
But to fully utilize this new window into the universe, we must compare these
new observations to detailed models of binary black hole formation throughout
cosmic time. Expanding upon our previous work (Rodriguez et al., 2015), we
study merging binary black holes formed in globular clusters using our Monte
Carlo approach to stellar dynamics. We have created a new set of 52 cluster
models with different masses, metallicities, and radii to fully characterize
the binary black hole merger rate. These models include all the relevant
dynamical processes (such as two-body relaxation, strong encounters, and
three-body binary formation) and agree well with detailed direct N-body
simulations. In addition, we have enhanced our stellar evolution algorithms
with updated metallicity-dependent stellar wind and supernova prescriptions,
allowing us to compare our results directly to the most recent population
synthesis predictions for merger rates from isolated binary evolution. We
explore the relationship between a cluster's global properties and the
population of binary black holes that it produces. In particular, we derive a
numerically calibrated relationship between the merger times of ejected black
hole binaries and a cluster's mass and radius. We explore the masses and mass
ratios of these binaries as a function of redshift, and find a merger rate of
~5 Gpc$^{-3}$ yr$^{-1}$ in the local universe, with 80% of sources having total
masses from $32M_{\odot}$ to $64M_{\odot}$. Under standard assumptions,
approximately 1 out of every 7 binary black hole mergers in the local universe
will have originated in a globular cluster, but we also explore the sensitivity
of this result to different assumptions for binary stellar evolution.
[Abridged]


title:
A Logspace Solution to the Word and Conjugacy problem of Generalized
  Baumslag-Solitar Groups

abstract:
  Baumslag-Solitar groups were introduced in 1962 by Baumslag and Solitar as
examples for finitely presented non-Hopfian two-generator groups. Since then,
they served as examples for a wide range of purposes. As Baumslag-Solitar
groups are HNN extensions, there is a natural generalization in terms of graph
of groups.
  Concerning algorithmic aspects of generalized Baumslag-Solitar groups,
several decidability results are known. Indeed, a straightforward application
of standard algorithms leads to a polynomial time solution of the word problem
(the question whether some word over the generators represents the identity of
the group). The conjugacy problem (the question whether two given words
represent conjugate group elements) is more complicated; still decidability has
been established by Anshel and Stebe for ordinary Baumslag-Solitar groups and
for generalized Baumslag-Solitar groups independently by Lockhart and Beeker.
However, up to now no precise complexity estimates have been given.
  In this work, we give a LOGSPACE algorithm for both problems. More precisely,
we describe a uniform TC^0 many-one reduction of the word problem to the word
problem of the free group. Then we refine the known techniques for the
conjugacy problem and show that it can be solved in LOGSPACE. Moreover, for
ordinary Baumslag-Solitar groups also conjugacy is AC^0-Turing-reducible to the
word problem of the free group.
  Finally, we consider uniform versions (where also the graph of groups is part
of the input) of both word and conjugacy problem: while the word problem still
is solvable in LOGSPACE, the conjugacy problem becomes EXPSPACE-complete.


title:
Reduction of branching graphs supporting continuous time return quantum
  walks

abstract:
  We demonstrate that continuous time quantum walks on several types of
branching graphs, including graphs with loops, are identical to quantum walks
on simpler linear chain graphs. We also show graph types for which such
equivalence does not exist. Several instructive examples are discussed, and a
general approach to analyze more complex branching graphs is formulated. It is
further illustrated with a return quantum walk solution for a cube graph with
adjustable complex hopping amplitudes.


title:
On Augmented Kohn-Sham Potential for Energy as a Simple Sum of Orbital
  Energies

abstract:
  It has recently been observed [Phys. Rev. Lett. 113, 113002 (2014)] that the
ground-state energy may be obtained directly as a simple sum of augmented
Kohn-Sham orbital energies, where it was ascertained that the corresponding
one-body shifted Kohn-Sham effective potential has appealing features. With
this in mind, eigenvalue and virial constraints are deduced for approximating
this potential.


title: Projective toric generators in the unitary cobordism ring

abstract:
  By the classical result of Milnor and Novikov, the unitary cobordism ring is
isomorphic to a graded polynomial ring with countably many generators:
$\Omega^U_*\simeq \mathbb Z[a_1,a_2,\dots]$, ${\rm deg}(a_i)=2i$. In this paper
we solve a well-known problem of constructing geometric representatives for
$a_i$ among smooth projective toric varieties, $a_n=[X^{n}], \dim_\mathbb C
X^{n}=n$. Our proof uses a family of equivariant modifications (birational
isomorphisms) $B_k(X)\to X$ of an arbitrary smooth complex manifold $X$ of
(complex) dimension $n$ ($n\geq 2$, $k=0,\dots,n-2$). The key fact is that the
change of the Milnor number under these modifications depends only on the
dimension $n$ and the number $k$ and does not depend on the manifold $X$
itself.


title: Orbital Magnetism of Bloch Electrons I. General Formula

abstract:
  We derive an exact formula of orbital susceptibility expressed in terms of
Bloch wave functions, starting from the exact one-line formula by Fukuyama in
terms of Green's functions. The obtained formula contains four contributions:
(1) Landau-Peierls susceptibility, (2) interband contribution, (3) Fermi
surface contribution, and (4) contribution from occupied states. Except for the
Landau-Peierls susceptibility, the other three contributions involve the
crystal-momentum derivatives of Bloch wave functions. Physical meaning of each
term is clarified. The present formula is simplified compared with those
obtained previously by Hebborn et al. Based on the formula, it is seen first of
all that diamagnetism from core electrons and Van Vleck susceptibility are the
only contributions in the atomic limit. The band effects are then studied in
terms of linear combination of atomic orbital treating overlap integrals
between atomic orbitals as a perturbation and the itinerant feature of Bloch
electrons in solids are clarified systematically for the first time.


title:
Loss factorization, weakly supervised learning and label noise
  robustness

abstract:
  We prove that the empirical risk of most well-known loss functions factors
into a linear term aggregating all labels with a term that is label free, and
can further be expressed by sums of the loss. This holds true even for
non-smooth, non-convex losses and in any RKHS. The first term is a (kernel)
mean operator --the focal quantity of this work-- which we characterize as the
sufficient statistic for the labels. The result tightens known generalization
bounds and sheds new light on their interpretation.
  Factorization has a direct application on weakly supervised learning. In
particular, we demonstrate that algorithms like SGD and proximal methods can be
adapted with minimal effort to handle weak supervision, once the mean operator
has been estimated. We apply this idea to learning with asymmetric noisy
labels, connecting and extending prior work. Furthermore, we show that most
losses enjoy a data-dependent (by the mean operator) form of noise robustness,
in contrast with known negative results.


title: Cusp formation for a nonlocal evolution equation

abstract:
  In this paper, we introduce a nonlocal evolution equation inspired by the
C\'ordoba-C\'ordoba-Fontelos nonlocal transport equation. The
C\'ordoba-C\'ordoba-Fontelos equation can be regarded as a model for the 2D
surface quasigeostrophic equation or the Birkhoff-Rott equation. We prove
blowup in finite time, and more importantly, investigate conditions under which
the solution forms a cusp in finite time.


title: Privacy Preserving Architectures for Collaborative Intrusion Detection

abstract:
  Collaboration among multiple organizations is imperative for contemporary
intrusion detection. As modern threats become well sophisticated it is
difficult for organizations to defend with threat context local to their
networks alone. Availability of global \emph{threat intelligence} is must for
organizations to defend against modern advanced persistent threats (APTs). In
order to benefit from such global context of attacks, privacy concerns continue
to be of major hindrance. In this position paper we identify real world privacy
problems as precise use cases, relevant cryptographic technologies and discuss
privacy preserving architectures for collaborative intrusion detection.


title: Testing general relativity using golden black-hole binaries

abstract:
  The coalescences of stellar-mass black-hole binaries through their inspiral,
merger, and ringdown are among the most promising sources for ground-based
gravitational-wave (GW) detectors. If a GW signal is observed with sufficient
signal-to-noise ratio, the masses and spins of the black holes can be estimated
from just the inspiral part of the signal. Using these estimates of the initial
parameters of the binary, the mass and spin of the final black hole can be
uniquely predicted making use of general-relativistic numerical simulations. In
addition, the mass and spin of the final black hole can be independently
estimated from the merger--ringdown part of the signal. If the binary black
hole dynamics is correctly described by general relativity (GR), these
independent estimates have to be consistent with each other. We present a
Bayesian implementation of such a test of general relativity, which allows us
to combine the constraints from multiple observations. Using kludge modified GR
waveforms, we demonstrate that this test can detect sufficiently large
deviations from GR, and outline the expected constraints from upcoming GW
observations using the second-generation of ground-based GW detectors.


title: Efficient Algorithms for Adversarial Contextual Learning

abstract:
  We provide the first oracle efficient sublinear regret algorithms for
adversarial versions of the contextual bandit problem. In this problem, the
learner repeatedly makes an action on the basis of a context and receives
reward for the chosen action, with the goal of achieving reward competitive
with a large class of policies. We analyze two settings: i) in the transductive
setting the learner knows the set of contexts a priori, ii) in the small
separator setting, there exists a small set of contexts such that any two
policies behave differently in one of the contexts in the set. Our algorithms
fall into the follow the perturbed leader family \cite{Kalai2005} and achieve
regret $O(T^{3/4}\sqrt{K\log(N)})$ in the transductive setting and $O(T^{2/3}
d^{3/4} K\sqrt{\log(N)})$ in the separator setting, where $K$ is the number of
actions, $N$ is the number of baseline policies, and $d$ is the size of the
separator. We actually solve the more general adversarial contextual
semi-bandit linear optimization problem, whilst in the full information setting
we address the even more general contextual combinatorial optimization. We
provide several extensions and implications of our algorithms, such as
switching regret and efficient learning with predictable sequences.


title:
Experimental test of non-classicality of quantum mechanics using an
  individual atomic solid-state quantum system

abstract:
  Quantum mechanics provides a statistical description about nature, and thus
would be incomplete if its statistical predictions could not be accounted for
some realistic models with hidden variables. There are, however, two powerful
theorems against the hidden-variable theories showing that certain quantum
features cannot be reproduced based on two rationale premises of classicality,
the Bell theorem, and noncontextuality, due to Bell, Kochen and Specker (BKS) .
Tests of the Bell inequality and the BKS theorem are both of fundamental
interests and of great significance . The Bell theorem has already been
experimentally verified extensively on many different systems , while the
quantum contextuality, which is independent of nonlocality and manifests itself
even in a single object, is experimentally more demanding. Moreover, the
contextuality has been shown to play a critical role to supply the `magic' for
quantum computation, making more extensive experimental verifications in
potential systems for quantum computing even more stringent. Here we report an
experimental verification of quantum contextuality on an individual atomic
nuclear spin-1 system in solids under ambient condition. Such a three-level
system is indivisible and thus the compatibility loophole, which exists in the
experiments performed on bipartite systems, is closed. Our experimental results
confirm that the quantum contextuality cannot be explained by nonlocal
entanglement, revealing the fundamental quantumness other than
locality/nonlocality within the intrinsic spin freedom of a concrete natural
atomic solid-state system at room temperature.


title: On Past Singularities in $k=0$ FLRW Cosmologies

abstract:
  The fundamental singularity theorem of FLRW cosmologies assumes that the
matter content in the cosmological model obeys the strong energy condition
along with a nonpositive cosmological constant which gives rise to an
irrotational geodesic singularity. In this paper, we show that the important
case of a spatially flat Friedmann-Lema\^{i}tre-Robertson-Walker universe with
barotropic matter obeying only the \emph{weak} energy condition with a
nonnegative cosmological constant also contains a past singularity. We
accomplish this using topological methods from dynamical systems theory. The
methods employed in this paper are sufficiently general that they could be
extended to other models to study the existence of past singularities.

categories: gr-qc astro-ph.CO math-ph math.DS math.MP


title:
Large-gradient and Lagrange singularities of solutions of a quasilinear
  parabolic equation

abstract:
  Asymptotic solutions of a quasilinear parabolic equation with a small
parameter at the higher derivative are constructed near large-gradient and
Lagrange singularities of A-type, which represent interest for studying
processes of shock waves formation in physical media with a small nonzero
viscosity.


title: Singularities of tangent surfaces to generic space curves

abstract:
  We give the complete solution to the local diffeomorphism classification
problem of generic singularities which appear in tangent surfaces, in as wider
situations as possible. We interpret tangent geodesics as tangent lines
whenever a (semi-)Riemannian metric, or, more generally, an affine connection
is given in an ambient space of arbitrary dimension. Then, given an immersed
curve, we define the tangent surface as the ruled surface by tangent geodesics
to the curve. We apply the characterization of frontal singularities found by
Kokubu, Rossman, Saji, Umehara, Yamada, and Fujimori, Saji, Umehara, Yamada,
and found by the first author related to the procedure of openings of
singularities.


title: Nuclear effects in deep inelastic scattering and transition region

abstract:
  We discuss nuclear effects on neutrino-nuclear interactions in a wide
kinematical range from shallow to deep inelastic scattering (DIS) region. There
is necessity from neutrino communities to have precise neutrino-nucleus cross
sections for future measurements on neutrino oscillations and leptonic CP
violation. We try to create a model to calculate neutrino cross sections in the
wide kinematical range, from quasi-elastic scattering and resonance productions
to the DIS. In this article, nuclear modifications of structure functions are
mainly discussed, and a possible extension to the $Q^2 \to 0$ region is
explained. We also comment on the transition region between baryon resonances
and the DIS. There are ongoing experimental efforts on nuclear modifications of
structure functions or parton distribution functions such as by pA reactions at
RHIC and LHC, Drell-Yan measurements at Fermilab, Miner$\nu$a neutrino DIS, and
charged-lepton DIS at JLab.


title: The reversal of the Sun's magnetic field in cycle 24

abstract:
  Analysis of synoptic data from the Vector Stokes Magnetograph (VSM) of the
Synoptic Optical Long-term Investigations of the Sun (SOLIS) and the NASA/NSO
Spectromagnetograph (SPM) at the NSO/Kitt Peak Vacuum Telescope facility shows
that the reversals of solar polar magnetic fields exhibit elements of a
stochastic process, which may include the development of specific patterns of
emerging magnetic flux, and the asymmetry in activity between northern and
southern hemispheres. The presence of such irregularities makes the modeling
and prediction of polar field reversals extremely hard if possible. In a
classical model of solar activity cycle, the unipolar magnetic regions (UMRs)
of predominantly following polarity fields are transported polewards due to
meridional flows and diffusion. The UMRs gradually cancel out the polar
magnetic field of the previous cycle, and re-build the polar field of opposite
polarity setting the stage for the next cycle. We show, however, that this
deterministic picture can be easily altered by the developing of a strong
center of activity, or by the emergence of an extremely large active region, or
by a "strategically placed" coronal hole. We demonstrate that the activity
occurring during the current cycle 24 may be the result of this randomness in
the evolution of the solar surface magnetic field.


title: Strengthening theorems of Dirac and Erd\H{o}s on disjoint cycles

abstract:
  Let $k \ge 3$ be an integer, $H_{k}(G)$ be the set of vertices of degree at
least $2k$ in a graph $G$, and $L_{k}(G)$ be the set of vertices of degree at
most $2k-2$ in $G$. In 1963, Dirac and Erd\H{o}s proved that $G$ contains $k$
(vertex-)disjoint cycles whenever $|H_{k}(G)| - |L_{k}(G)| \ge k^{2} + 2k - 4$.
The main result of this paper is that for $k \ge 2$, every graph $G$ with
$|V(G)| \ge 3k$ containing at most $t$ disjoint triangles and with $|H_{k}(G)|
- |L_{k}(G)| \ge 2k + t$ contains $k$ disjoint cycles. This yields that if $k
\ge 2$ and $|H_{k}(G)| - |L_{k}(G)| \ge 3k$, then $G$ contains $k$ disjoint
cycles. This generalizes the Corr\'{a}di-Hajnal Theorem, which states that
every graph $G$ with $H_{k}(G) = V(G)$ and $|H_{k}(G)| \ge 3k$ contains $k$
disjoint cycles.


title: The CDEX Dark Matter Program at the China Jinping Underground Laboratory

abstract:
  The China Jinping Underground Laboratory (CJPL) is a new facility for
conducting low event-rate experiments. We present an overview of CJPL and the
CDEX Dark Matter program based on germanium detectors with sub-keV
sensitivities. The achieved results, status as well as the R&D and technology
acquisition efforts towards a ton-scale experiment are reported.

categories: physics.ins-det astro-ph.CO hep-ex nucl-ex


title:
Total Born cross section of $e^+e^-$-pair production in relativistic ion
  collisions from differential equations

abstract:
  We apply the differential equation method to the calculation of the total
Born cross section of the process $Z_1Z_2\to Z_1Z_2e^+e^-$. We obtain explicit
expression for the cross section exact in the relative velocity of the nuclei.


title: Winding numbers of regular closed curves on aspherical surfaces

abstract:
  We define winding numbers of regular closed curves on surfaces with a nice
euclidean or hyperbolic geometry. We prove that two regular closed curves are
regularly homotopic if and only if they are freely homotopic and have the same
winding number.


title: Dependence of vector fields and singular controls

abstract:
  We show an example providing a significance in geometric control theory of
the existence of the dependence locus of a system of vector fields in
particular, the generic appearance of non-trivial singular trajectories
embedded in the dependence locus.


title: Overfitting hidden Markov models with an unknown number of states

abstract:
  This paper presents new theory and methodology for the Bayesian estimation of
overfitted hidden Markov models, with finite state space. The goal is then to
achieve posterior emptying of extra states. A prior configuration is
constructed which favours configurations where the hidden Markov chain remains
ergodic although it empties out some of the states. Asymptotic posterior
convergence rates are proven theoretically, and demonstrated with a large
sample simulation. The problem of overfitted HMMs is then considered in the
context of smaller sample sizes, and due to computational and mixing issues two
alternative prior structures are studied, one commonly used in practice, and a
mixture of the two priors. The Prior Parallel Tempering approach of van Havre
(2015) is also extended to HMMs to allow MCMC estimation of the complex
posterior space. A replicate simulation study and an in-depth exploration is
performed to compare the three priors with hyperparameters chosen according to
the asymptotic constraints alongside less informative alternatives.


title: Solving the small-scale structure puzzles with dissipative dark matter

abstract:
  Small-scale structure is studied in the context of dissipative dark matter,
arising for instance in models with a hidden unbroken Abelian sector, so that
dark matter couples to a massless dark photon. The dark sector interacts with
ordinary matter via gravity and photon-dark photon kinetic mixing. Mirror dark
matter is a theoretically constrained special case where all parameters are
fixed except for the kinetic mixing strength, $\epsilon$. In these models, the
dark matter halo around spiral and irregular galaxies takes the form of a
dissipative plasma which evolves in response to various heating and cooling
processes. It has been argued previously that such dynamics can account for the
inferred cored density profiles of galaxies and other related structural
features. Here we focus on the apparent deficit of nearby small galaxies
("missing satellite problem"), which these dissipative models have the
potential to address through small-scale power suppression by acoustic and
diffusion damping. Using a variant of the extended Press-Schechter formalism,
we evaluate the halo mass function for the special case of mirror dark matter.
Considering a simplified model where $M_{\text{baryons}} \propto
M_{\text{halo}}$, we relate the halo mass function to more directly observable
quantities, and find that for $\epsilon/10^{-10} \approx 2$ such a simplified
description is compatible with the measured galaxy luminosity and velocity
functions. On scales $M_{\text{halo}} \lesssim 10^8 \ M_\odot$, diffusion
damping exponentially suppresses the halo mass function, suggesting a
nonprimordial origin for dwarf spheroidal satellite galaxies, which we
speculate were formed via a top-down fragmentation process as the result of
nonlinear dissipative collapse of larger density perturbation. This could
explain the planar orientation of satellite galaxies around Andromeda and the
Milky Way.


title:
On the Conceptual Issues Surrounding the Notion of Relational Bohmian
  Dynamics

abstract:
  The paper presents a program to construct a non-relativistic relational
Bohmian theory, that is, a theory of $N$ moving point-like particles that
dispenses with space and time as fundamental background structures. The
relational program proposed is based on the best-matching framework originally
developed by Julian Barbour. In particular, the paper focuses on the conceptual
problems that arise when trying to implement such a program. It is argued that
pursuing a relational strategy in the Bohmian context leads to a more
parsimonious ontology than that of standard Bohmian mechanics without betraying
the original motivations for adopting a primitive ontology approach to quantum
physics. It is also shown how a relational Bohmian approach might clarify the
issue of the timelessness of the dynamics resulting from the quantization of a
classical relational system of particles.


title: The Sudbury Neutrino Observatory

abstract:
  This review paper provides a summary of the published results of the Sudbury
Neutrino Observatory (SNO) experiment that was carried out by an international
scientific collaboration with data collected during the period from 1999 to
2006. By using heavy water as a detection medium, the SNO experiment
demonstrated clearly that solar electron neutrinos from $^8$B decay in the
solar core change into other active neutrino flavors in transit to Earth. The
reaction on deuterium that has equal sensitivity to all active neutrino flavors
also provides a very accurate measure of the initial solar flux for comparison
with solar models. This review summarizes the results from three phases of
solar neutrino detection as well as other physics results obtained from
analyses of the SNO data.


title:
A Generalized Ising Model for studying Alloy Evolution under Irradiation
  and its use in Kinetic Monte Carlo Simulations

abstract:
  We derive an Ising Hamiltonian for kinetic simulations involving interstitial
and vacancy defects in binary alloys. Our model, which we term `ABVI',
incorporates solute transport by both interstitial defects and vacancies into a
mathematically-consistent framework , and thus represents a generalization to
the widely-used ABV model for alloy evolution simulations. The Hamiltonian
captures the three possible interstitial configurations in a binary alloy: A-A,
A-B, and B-B, which makes it particularly useful for irradiation damage
simulations. All the constants of the Hamiltonian are expressed in terms of
bond energies that can be computed using first-principles calculations. We
implement our ABVI model in kinetic Monte Carlo simulations and perform a
verification exercise by comparing our results to published irradiation damage
simulations in simple binary systems with Frenkel pair defect production and
several microstructural scenarios, with matching agreement found.


title:
Comment on "Higher Order Pancharatnam-Berry Phase and the Angular
  Momentum of Light"

abstract:
  In a recent letter, Milione et al. reported the Pancharatnam-Berry phase
(PBP) on a higher-order Poincar\'e sphere (HOPS) [Phys. Rev. Lett, 108, 190401
(2012)]. They used two spin-orbit converters (SOCs) to make a trajectory along
the HOPS. However, the SOCs actually do not make a path on the HOPS. We briefly
discuss a way of acquiring a PBP made by SOCs.


title:
On the local exact controllability of micropolar fluids with few
  controls

abstract:
  In this paper, we study the local exact controllability to special
trajectories of the micropolar fluid systems in dimension d = 2 and d = 3. We
show that controllability is possible acting only on one velocity.


title: Particle Swarm Optimized Power Consumption of Trilateration

abstract:
  Trilateration-based localization (TBL) has become a corner stone of modern
technology. This study formulates the concern on how wireless sensor networks
can take advantage of the computational intelligent techniques using both
single- and multi-objective particle swarm optimization (PSO) with an overall
aim of concurrently minimizing the required time for localization, minimizing
energy consumed during localization, and maximizing the number of nodes fully
localized through the adjustment of wireless sensor transmission ranges while
using TBL process. A parameter-study of the applied PSO variants is performed,
leading to results that show algorithmic improvements of up to 32% in the
evaluated objectives.


title:
Analysis of the Pancharatnam-Berry phase of vector vortex states using
  the Hamiltonian based on the Maxwell-Schr\"odinger equation

abstract:
  We derived the Berry connection of vector vortex states (VVSs) from the
"true" Hamiltonian obtained through the Maxwell--Schr\"odinger equation for an
inhomogeneous anisotropic (IA) medium, and we experimentally demonstrated
measurement of the corresponding Pancharatnam--Berry (PB) geometrical phase of
VVSs. The PB phase (PBP) of VVSs can be divided into two phases: homogeneous
and inhomogeneous PBPs. Homogeneous and inhomogeneous PBPs are related to the
conventional PBP and the spatially-dependent geometric phase given by an IA
medium such as a polarization converter, respectively. We theoretically
detected that inhomogeneous PBP accumulation originates from the gauge
dependence of the index of the hybrid-order Poincar\'e sphere, which provides
an alternate method for understanding optical spin--orbital angular momentum
conversion. The homogeneous PBP, which is explicitly observed for the first
time, has implications for quantum state manipulation and information
processing.


title:
Algorithmic construction of Shimura - Taniyama - Weil parametrization of
  elliptic curves over the rationals

abstract:
  In this note we give an algorithm to explicitly construct the modular
parametrization of an elliptic curve over the rationals given the Weierstrass
function $\wp (z)$.


title: Quasiperiodic driving of Anderson localized waves in one dimension

abstract:
  We consider a quantum particle in a one-dimensional disordered lattice with
Anderson localization, in the presence of multi-frequency perturbations of the
onsite energies. Using the Floquet representation, we transform the eigenvalue
problem into a Wannier-Stark basis. Each frequency component contributes either
to a single channel or a multi-channel connectivity along the lattice,
depending on the control parameters. The single channel regime is essentially
equivalent to the undriven case. The multi-channel driving substantially
increases the localization length for slow driving, showing two different
scaling regimes of weak and strong driving, yet the localization length stays
finite for a finite number of frequency components.


title: GJMS operators and Q-curvature for conformal Codazzi structures

abstract:
  The conformal Codazzi structure is an intrinsic geometric structure on
strictly convex hypersufaces in a locally flat projective manifold. We
construct the GJMS operators and the Q-curvature for conformal Codazzi
structures by using the ambient metric. We relate the total Q-curvature to the
logarithmic coefficient in the volume expansion of the Blaschke metric, and
derive the first and second variation formulas for a deformation of strictly
convex domains.


title: Quantum Phase Transitions of the Bose-Hubbard Model inside a Cavity

abstract:
  The superfluid to Mott insulator transition and the superradiant transition
are textbook examples for quantum phase transition and coherent quantum optics,
respectively. Recent experiments in ETH and Hamburg succeeded in loading
degenerate bosonic atomic gases in optical lattices inside a cavity, which
enables the first experimental study of the interplay between these two
transitions. In this letter we present the theoretical phase diagram for the
ETH experimental setup, and determine the phase boundaries and the orders of
the phase transitions between the normal superfluid phase, the superfluid with
superradiant light, the normal Mott insulator and the Mott insulator with
superradiant light. We find that in contrast to the second-order superradiant
transition in a weakly interacting Bose condensate, strong correlations in the
superfluid nearby a Mott transition can render the superradiant transition to a
first order one. Our results will stimulate further experimental studies of
interactions between cavity light and strongly interacting quantum matters.


title: Phase separated behavior in Yttrium doped CaMnO3

abstract:
  The effect of electron doping on the structural, transport, and magnetic
properties of Mn (IV) - rich Ca1-xYxMnO3 (x < 0.2) samples have been
investigated using neutron diffraction, neutron depolarization, magnetization
and resistivity techniques. The temperature dependence of resistivity follows
the small polaron model and the activation energy exhibits a minimum for x=0.1
sample. A phase separated magnetic ground state consisting of ferromagnetic
domains (~7microns) embedded in G-type antiferromagnetic matrix is observed in
the sample, x = 0.1. The transition to the long range magnetically ordered
state in this sample is preceded by a Griffiths phase. On lowering temperature
below 300K a structural transition from orthorhombic structure (Pnma) to a
monoclinic structure (P21/m) is observed in the case of x=0.2 sample. The
ferromagnetic behavior in this case is suppressed and the antiferromagnetic
ordering is described by coexisting C-type and G-type magnetic structures
corresponding to the monoclinic and orthorhombic phases, respectively.<


title:
Convergence of random sums and statistics constructed from samples with
  random sizes to the Linnik and Mittag-Leffler distributions and their
  generalizations

abstract:
  We present some product representations for random variables with the Linnik,
Mittag-Leffler and Weibull distributions and establish the relationship between
the mixing distributions in these representations. Based on these
representations, we prove some limit theorems for a wide class of rather simple
statistics constructed from samples with random sized including, e. g., random
sums of independent random variables with finite variances, maximum random
sums, extreme order statistics, in which the Linnik and Mittag-Leffler
distributions play the role of limit laws. Thus we demonstrate that the scheme
of geometric summation is far not the only asymptotic setting (even for sums of
independent random variables) in which the Mittag-Leffler and Linnik laws
appear as limit distributions. The two-sided Mittag-Leffler and one-sided
Linnik distribution are introduced and also proved to be limit laws for some
statistics constructed from samples with random sizes.


title: A Large Dataset of Object Scans

abstract:
  We have created a dataset of more than ten thousand 3D scans of real objects.
To create the dataset, we recruited 70 operators, equipped them with
consumer-grade mobile 3D scanning setups, and paid them to scan objects in
their environments. The operators scanned objects of their choosing, outside
the laboratory and without direct supervision by computer vision professionals.
The result is a large and diverse collection of object scans: from shoes, mugs,
and toys to grand pianos, construction vehicles, and large outdoor sculptures.
We worked with an attorney to ensure that data acquisition did not violate
privacy constraints. The acquired data was irrevocably placed in the public
domain and is available freely at http://redwood-data.org/3dscan .


title: Crossed Modules of Algebras as Ideal Maps

abstract:
  In this work, we explore the close relationship between an ideal map
structure S --> End(R) on a homomorphism of commutative k-algebras R --> S and
an ideal simplicial algebra structure on the associated bar construction Bar(S,
R).


title:
Solar activity during the Holocene: the Hallstatt cycle and its
  consequence for grand minima and maxim

abstract:
  Cosmogenic isotopes provide the only quantitative proxy for analyzing the
long-term solar variability over a centennial timescale. While essential
progress has been achieved in both measurements and modeling of the cosmogenic
proxy, uncertainties still remain in the determination of the geomagnetic
dipole moment evolution. Here we improve the reconstruction of solar activity
over the past nine millennia using a multi-proxy approach. We used records of
the 14C and 10Be cosmogenic isotopes, current numerical models of the isotope
production and transport in Earth's atmosphere, and available geomagnetic field
reconstructions, including a new reconstruction relying on an updated
archeo-/paleointensity database. The obtained series were analyzed using the
singular spectrum analysis (SSA) method to study the millennial-scale trends. A
new reconstruction of the geomagnetic dipole field moment, GMAG.9k, is built
for the last nine millennia. New reconstructions of solar activity covering the
last nine millennia, quantified in sunspot numbers, are presented and analyzed.
A conservative list of grand minima and maxima is provided. The primary
components of the reconstructed solar activity, as determined using the SSA
method, are different for the series based on 14C and 10Be. These primary
components can only be ascribed to long-term changes in the terrestrial system
and not to the Sun. They have been removed from the reconstructed series. In
contrast, the secondary SSA components of the reconstructed solar activity are
found to be dominated by a common ~2400-yr quasi-periodicity, the so-called
Hallstatt cycle, in both the 14C and 10Be based series. This Hallstatt cycle
thus appears to be related to solar activity. Finally, we show that the grand
minima and maxima occurred intermittently over the studied period, with
clustering near highs and lows of the Hallstatt cycle, respectively.


title: Symmetric Kneser's Theorem with Trios and $3$-Transform

abstract:
  We give a new equivalent restatement and a new proof in terms of trios to the
classical Kneser's theorem. In the finite case, our restatement takes the
following, particularly symmetric shape: if $A$, $B$, and $C$ are subsets of a
finite abelian group $G$ such that $A+B+C\ne G$, then, denoting by $H$ the
period of the sumset $A+B+C$, we have
  $$ |A|+|B|+|C| \le |G|+|H|. $$ The proof is based on an extension of the
familiar Dyson transform onto set systems containing three (or more) sets.


title:
Simultaneous Safe Screening of Features and Samples in Doubly Sparse
  Modeling

abstract:
  The problem of learning a sparse model is conceptually interpreted as the
process of identifying active features/samples and then optimizing the model
over them. Recently introduced safe screening allows us to identify a part of
non-active features/samples. So far, safe screening has been individually
studied either for feature screening or for sample screening. In this paper, we
introduce a new approach for safely screening features and samples
simultaneously by alternatively iterating feature and sample screening steps. A
significant advantage of considering them simultaneously rather than
individually is that they have a synergy effect in the sense that the results
of the previous safe feature screening can be exploited for improving the next
safe sample screening performances, and vice-versa. We first theoretically
investigate the synergy effect, and then illustrate the practical advantage
through intensive numerical experiments for problems with large numbers of
features and samples.


title:
Some Minimax Results on Dense Sets and Dense Families of Functionals in
  C(K) and B(K)

abstract:
  In this paper, by an example we show that the general minimax results of Fan
and Sion cannot be extended on usual dense sets. Nevertheless, we obtain some
new minimax results on a special type of dense set that we call
self-segment-dense. We apply our results in order to obtain denseness of some
family of functionals in function spaces.


title:
Equivariant A-twisted GLSM and Gromov--Witten invariants of CY 3-folds
  in Grassmannians

abstract:
  We compute genus-zero Gromov--Witten invariants of Calabi--Yau complete
intersection 3-folds in Grassmannians using supersymmetric localization in
A-twisted non-Abelian gauged linear sigma models. We also discuss a
Seiberg-like duality interchanging Gr(n,m) and Gr(m-n,m).


title: A quantum-enabled Rydberg atom electrometer

abstract:
  There is no fundamental limit to the precision of a classical measurement.
The position of a meter's needle can be determined with an arbitrarily small
uncertainty. In the quantum realm, however, fundamental quantum fluctuations
due to the Heisenberg principle limit the measurement precision. The simplest
measurement procedures, involving semi-classical states of the meter, lead to a
fluctuation-limited imprecision at the standard quantum limit. By engineering
the quantum state of the meter system, the measurement imprecision can be
reduced down to the fundamental Heisenberg Limit (HL). Quantum-enabled
metrology techniques are thus in high demand and the focus of an intense
activity. We report here a quantum-enabled measurement of an electric field
based on this approach. We cast Rydberg atoms in Schr\"odinger cat states,
superpositions of atomic levels with radically different polarizabilites. We
use a quantum interference process to perform a measurement close to the HL,
reaching a single-shot sensitivity of 1.2 mV/cm for a 100 ns interaction time,
corresponding to 30 $\mu$V/cm/Hz^(1/2) at our 3 kHz repetition rate. This
highly sensitive, non-invasive space- and time-resolved field measurement
extends the realm of electrometric techniques and could have important
practical applications. Detection of individual electrons in mesoscopic devices
at a ~100 $\mu$m distance, with a MegaHertz bandwith is within reach.


title: Note on a parameter switching method for nonlinear ODEs

abstract:
  In this paper we study analytically a parameter switching (PS) algorithm
applied to a class of systems of ODE, depending on a single real parameter. The
algorithm allows the numerical approximation of any solution of the underlying
system by simple periodical switches of the control parameter. Near a general
approach of the convergence of the PS algorithm, some dissipative properties
are investigated and the dynamical behavior of solutions is investigated with
the Lyapunov function method. A numerical example is presented


title:
Simulation of bifurcated stent grafts to treat abdominal aortic
  aneurysms (AAA)

abstract:
  In this paper a method is introduced, to visualize bifurcated stent grafts in
CT-Data. The aim is to improve therapy planning for minimal invasive treatment
of abdominal aortic aneurysms (AAA). Due to precise measurement of the
abdominal aortic aneurysm and exact simulation of the bifurcated stent graft,
physicians are supported in choosing a suitable stent prior to an intervention.
The presented method can be used to measure the dimensions of the abdominal
aortic aneurysm as well as simulate a bifurcated stent graft. Both of these
procedures are based on a preceding segmentation and skeletonization of the
aortic, right and left iliac. Using these centerlines (aortic, right and left
iliac) a bifurcated initial stent is constructed. Through the implementation of
an ACM method the initial stent is fit iteratively to the vessel walls - due to
the influence of external forces (distance- as well as balloonforce). Following
the fitting process, the crucial values for choosing a bifurcated stent graft
are measured, e.g. aortic diameter, right and left common iliac diameter,
minimum diameter of distal neck. The selected stent is then simulated to the
CT-Data - starting with the initial stent. It hereby becomes apparent if the
dimensions of the bifurcated stent graft are exact, i.e. the fitting to the
arteries was done properly and no ostium was covered.

categories: cs.GR cs.CE cs.CG physics.med-ph q-bio.TO


title: Two-sample tests for high-dimension, strongly spiked eigenvalue models

abstract:
  We consider two-sample tests for high-dimensional data under two disjoint
models: the strongly spiked eigenvalue (SSE) model and the non-SSE (NSSE)
model. We provide a general test statistic as a function of a
positive-semidefinite matrix. We give sufficient conditions for the test
statistic to satisfy a consistency property and to be asymptotically normal. We
discuss an optimality of the test statistic under the NSSE model. We also
investigate the test statistic under the SSE model by considering strongly
spiked eigenstructures and create a new effective test procedure for the SSE
model. Finally, we discuss the performance of the classifiers numerically.


title:
NMR based Pharmaco-metabolomics: An efficient and agile tool for
  therapeutic evaluation of Traditional Herbal Medicines

abstract:
  Traditional Indian (Ayurvedic) and Chinese herbal medicines have been used in
the treatment of a variety of diseases for thousands of years because of their
natural origin and lesser side effects. However, the safety and efficacy data
(including dose and quality parameters) on most of these traditional medicines
are far from sufficient to meet the criteria needed to support their world-wide
therapeutic use. Also, the mechanistic understanding of most of these herbal
medicines is still lacking due to their complex components which further limits
their wider application and acceptance. Metabolomics -a novel approach to
reveal altered metabolism (biochemical effects) produced in response to a
disease or its therapeutic intervention- has huge potential to assess the
pharmacology and toxicology of traditional herbal medicines (THMs). Therefore,
it is gradually becoming a mutually complementary technique to genomics,
transcriptomics and proteomics for therapeutic evaluation of pharmaceutical
products (including THMs); the approach is so called pharmaco-metabolomics. The
whole paradigm is based on its ability to provide metabolic signatures to
confirm the diseased condition and then to use the concentration profiles of
these biomarkers to assess the therapeutic response. Nuclear magnetic resonance
(NMR) spectroscopy coupled with multivariate data analysis is currently the
method of choice for pharmaco-metabolomics studies owing to its unbiased,
non-destructive nature and minimal sample preparation requirement. In recent
past, dozens of NMR based pharmaco-metabolomic studies have been devoted to
prove the therapeutic efficacy/safety and to explore the underlying mechanisms
of THMs, with promising results. The current perspective article summarizes
various such studies in addition to describing the technical and conceptual
aspects involved in NMR based pharmaco-metabolomics.


title:
Analysis of Location Management Schemes for MANET using Synthetic
  Mobility Models

abstract:
  In the performance evaluation of a protocol for an ad hoc network, the
protocol should be tested under realistic conditions including, but not limited
to, a sensible transmission range, limited buffer space for the storage of
messages, representative data traffic models, and realistic movements of the
mobile users and several mobility models that represent mobile nodes whose
movements are dependent on each other (i.e., group mobility models ).The goal
of this paper is to simulate the movements of mobile nodes within a network and
present a number of mobility models in order to demonstrate its effect on
Location management scheme for mobile ad hoc network or personal communication
services networks. Specifically, to illustrate how the performance results of
an ad hoc network protocol drastically change as a result of changing the
mobility model simulated. Location management is a fundamental problem in
personal communication services network. The current standard of location
management is HLR/VLR scheme. It has been observed that the performance of any
location management scheme depends on space requirements, bandwidth
requirements and time requirements. To avoid certain drawbacks in HLR/VLR
scheme, many approaches including hierarchical approaches have been suggested.
Working set idea is chosen to analyze its performance for location management
in PCS networks. Due to inadequacy of standard network simulators to provide
the output in the format desired, a new location management simulator can be
built. Two variants of working set idea viz. Working set scheme for HLR/VLR
approach and working set scheme for hierarchical approach can be used and then
compare the performance of HLR/VLR scheme and working set scheme using the
results obtained by the simulator with respect to already available mobile
activity traces.


title:
Higher-order local and non-local correlations for 1D strongly
  interacting Bose gas

abstract:
  The correlation function is an important quantity in the physics of ultracold
quantum gases because it provides information about the quantum many-body wave
function beyond the simple density profile. In this paper we first study the
$M$-body local correlation functions, $g_M$, of the one-dimensional (1D)
strongly repulsive Bose gas within the Lieb-Liniger model using the analytical
method proposed by Gangardt and Shlyapnikov [1,2]. In the strong repulsion
regime the 1D Bose gas at low temperatures is equivalent to a gas of ideal
particles obeying the non-mutual generalized exclusion statistics (GES) with a
statistical parameter $\alpha =1-2/\gamma$, i.e. the quasimomenta of $N$
strongly interacting bosons map to the momenta of $N$ free fermions via
$k_i\approx \alpha k_i^F $ with $i=1,\ldots, N$. Here $\gamma$ is the
dimensionless interaction strength within the Lieb-Liniger model. We rigorously
prove that such a statistical parameter $\alpha$ solely determines the
sub-leading order contribution to the $M$-body local correlation function of
the gas at strong but finite interaction strengths. We explicitly calculate the
correlation functions $g_M$ in terms of $\gamma$ and $\alpha$ at zero, low, and
intermediate temperatures. For $M=2$ and $3$ our results reproduce the known
expressions for $g_{2}$ and $g_{3}$ with sub-leading terms (see for instance
[3-5]). We also express the leading order of the short distance
\emph{non-local} correlation functions
$\langle\Psi^\dagger(x_1)\cdots\Psi^\dagger(x_M)\Psi(y_M)\cdots\Psi(y_1)\rangle$
of the strongly repulsive Bose gas in terms of the wave function of $M$ bosons
at zero collision energy and zero total momentum. Here $\Psi(x)$ is the boson
annihilation operator. These general formulas of the higher-order local and
non-local correlation functions of the 1D Bose gas provide new insights into
the many-body physics.


title: How fast can Maker win in fair biased games?

abstract:
  We study (a:a) Maker-Breaker games played on the edge set of the complete
graph on n vertices. In the following four games - perfect matching game,
Hamilton cycle game, star factor game and path factor game, our goal is to
determine the least number of moves which Maker needs in order to win these
games. Moreover, for all games except for the star factor game, we show how Red
can win in the strong version of these games.


title: About Geometry and Initial Phase of Cloud-to-Ground Lightning

abstract:
  Cloud-to-ground lightning is the most common among atmospheric discharges.
Since electric fields in the vicinity of a thunder-cloud do not exceed 250 kV/m
the physical process that triggers the lightning remains unexplained. [1, 2, 3]
Recent measurements established a weak correlation between solar wind and
incidence of lightning. [4] Here we show, that if an ionized path created by
cosmic rays provides a trigger, the distribution of lengths between two
successive forking points in a lightning channel (internodes) closely resembles
the exponential distribution with average length between 415 m and 510 m. The
results, if confirmed, imply that a thunder-cell may be an additional source of
fast elementary particles that initiate lightning process.


title:
Phase matched backward-wave second harmonic generation in a hyperbolic
  carbon nanoforest

abstract:
  We show that deliberately engineered spatially dispersive metamaterial slab
can enable co-existence and phase matching of contra-propagating ordinary
fundamental and backward second harmonic electromagnetic modes. Energy flux and
phase velocity are contra-directed in backward waves which determines
extraordinary nonlinear-optical propagation processes. Frequencies, phase and
group velocities, as well as nanowavequide losses inherent to the
electromagnetic modes supported by the metamaterial can be tailored to optimize
nonlinear-optical conversion of frequencies and propagation directions of the
coupled waves. Such a possibility, which is of paramount importance for
nonlinear photonics, is proved with numerical model of the hyperbolic
metamaterial made of carbon nanotubes standing on metal surface. Extraordinary
properties of backward-wave second harmonic in the THz and IR propagating in
the reflection direction are investigated with focus on pulsed regime.