title: Velocity-Space Proton Diffusion in the Solar Wind Turbulence

abstract:
  We study a velocity-space quasilinear diffusion of the solar wind protons
driven by oblique Alfven turbulence at proton kinetic scales. Turbulent
fluctuations at these scales possess properties of kinetic Alfven waves (KAWs)
that are efficient in Cherenkov resonant interactions. The proton diffusion
proceeds via Cherenkov kicks and forms a quasilinear plateau - nonthermal
proton tail in the velocity distribution function (VDF). The tails extend in
velocity space along the mean magnetic field from 1 to (1.5-3) VA, depending on
the spectral break position, turbulence amplitude at the spectral break, and
spectral slope after the break. The most favorable conditions for the tail
generation occur in the regions where the proton thermal and Alfven velocities
are about the same, VTp/VA = 1. The estimated formation times are within 1-2 h
for typical tails at 1 AU, which is much shorter than the solar wind expansion
time. Our results suggest that the nonthermal proton tails, observed in-situ at
all heliocentric distances beyond 0.3 AU, are formed in the solar wind locally
by the KAW turbulence. We also suggest that the bump-on-tail features - proton
beams, often seen in the proton VDFs, can be formed at a later evolution stage
of the nonthermal tails by the time-of-flight effects.


title: The Minimal Resultant Locus

abstract:
  Let K be a complete, algebraically closed nonarchimedean valued field, and
let f(z) in K(z) be a rational function of degree d at least 2. We give an
algorithm to determine whether f(z) has potential good reduction over K, based
on a geometric reformulation of the problem using the Berkovich Projective
Line. We show the minimal resultant is is either achieved at a single point in
the Berkovich line, or on a segment, and that minimal resultant locus is
contained in the tree in spanned by the fixed points and the poles of f(z).
When f(z) is defined over the rationals, the algorithm runs in probabilistic
polynomial time. If f(z) has potential good reduction, and is defined over a
subfield H of K, we show there is an extension L/H in K with degree at most (d
+ 1)^2 such that f(z) achieves good reduction over L.


title: High rate locally correctable codes via lifting

abstract:
  We present a general framework for constructing high rate error correcting
codes that are locally correctable (and hence locally decodable if linear) with
a sublinear number of queries, based on lifting codes with respect to functions
on the coordinates. Our approach generalizes the lifting of affine-invariant
codes of Guo, Kopparty, and Sudan and its generalization automorphic lifting,
suggested by Ben-Sasson et al, which lifts algebraic geometry codes with
respect to a group of automorphisms of the code. Our notion of lifting is a
natural alternative to the degree-lifting of Ben-Sasson et al and it carries
two advantages. First, it overcomes the rate barrier inherent in
degree-lifting. Second, it is extremely flexible, requiring no special
properties (e.g. linearity, invariance) of the base code, and requiring very
little structure on the set of functions on the coordinates of the code.
  As an application, we construct new explicit families of locally correctable
codes by lifting algebraic geometry codes. Like the multiplicity codes of
Kopparty, Saraf, Yekhanin and the affine-lifted codes of Guo, Kopparty, Sudan,
our codes of block-length $N$ can achieve $N^\epsilon$ query complexity and
$1-\alpha$ rate for any given $\epsilon, \alpha > 0$ while correcting a
constant fraction of errors, in contrast to the Reed-Muller codes and the
degree-lifted AG codes of Ben-Sasson et al which face a rate barrier of
$\epsilon^{O(1/\epsilon)}$. However, like the degree-lifted AG codes, our codes
are over an alphabet significantly smaller than that obtained by Reed-Muller
codes, affine-lifted codes, and multiplicity codes.


title: Aliasing-reduced Fresnel diffraction with scale and shift operations

abstract:
  Numerical simulation of Fresnel diffraction with fast Fourier transform (FFT)
is widely used in optics, especially computer holography. Fresnel diffraction
with FFT cannot set different sampling rates between source and destination
planes, while shifted-Fresnel diffraction can set different rates. However, an
aliasing error may be incurred in shifted-Fresnel diffraction in a short
propagation distance, and the aliasing conditions have not been investigated.
In this paper, we investigate the aliasing conditions of shifted-Fresnel
diffraction and improve its properties based on the conditions.


title: Rota-Baxter Algebra. The Combinatorial Structure of Integral Calculus

abstract:
  Gian-Carlo Rota suggested in one of his last articles the problem of
developing a theory around the notion of integration algebras, complementary to
the already existing theory of differential algebras. This idea was mainly
motivated by Rota's deep appreciation for Kuo-Tsai Chen's seminal work on
iterated integrals. As a starting point for such a theory of integration
algebras Rota proposed to consider a particular operator identity first
introduced by the mathematician Glen Baxter. Later it was coined Rota-Baxter
identity. In this article we briefly recall basic properties of Rota--Baxter
algebras, and present a concise review of recent work with a particular
emphasis of noncommutative aspects.


title: Minimum number of distinct eigenvalues of graphs

abstract:
  The minimum number of distinct eigenvalues, taken over all real symmetric
matrices compatible with a given graph $G$, is denoted by $q(G)$. Using other
parameters related to $G$, bounds for $q(G)$ are proven and then applied to
deduce further properties of $q(G)$. It is shown that there is a great number
of graphs $G$ for which $q(G)=2$. For some families of graphs, such as the join
of a graph with itself, complete bipartite graphs, and cycles, this minimum
value is obtained. Moreover, examples of graphs $G$ are provided to show that
adding and deleting edges or vertices can dramatically change the value of
$q(G)$. Finally, the set of graphs $G$ with $q(G)$ near the number of vertices
is shown to be a subset of known families of graphs with small maximum
multiplicity.


title: Finding Primitive Elements in Finite Fields of Small Characteristic

abstract:
  We describe a deterministic algorithm for finding a generating element of the
multiplicative group of the finite field $\mathbb{F}_{p^n}$ where $p$ is a
prime. In time polynomial in $p$ and $n$, the algorithm either outputs an
element that is provably a generator or declares that it has failed in finding
one. The algorithm relies on a relation generation technique in Joux's
heuristically $L(1/4)$-method for discrete logarithm computation. Based on a
heuristic assumption, the algorithm does succeed in finding a generator. For
the special case when the order of $p$ in $(\mathbb{Z}/n\mathbb{Z})^\times$ is
small (that is $(\log_p(n))^{\mathcal{O}(1)}$), we present a modification with
greater guarantee of success while making weaker heuristic assumptions.


title:
Fourier-Reflexive Partitions and MacWilliams Identities for Additive
  Codes

abstract:
  A partition of a finite abelian group gives rise to a dual partition on the
character group via the Fourier transform. Properties of the dual partitions
are investigated and a convenient test is given for the case that the bidual
partition coincides the primal partition. Such partitions permit MacWilliams
identities for the partition enumerators of additive codes. It is shown that
dualization commutes with taking products and symmetrized products of
partitions on cartesian powers of the given group. After translating the
results to Frobenius rings, which are identified with their character module,
the approach is applied to partitions that arise from poset structures.


title: On The Drift Paradox in a Regime-Switching Model

abstract:
  This note is motivated by the article by F. Lutscher, E. Pachepsky, and M.
Lewis (2005), The Effect of Dispersal Patterns on Stream Populations SIAM Rev.
Vol. 47 No. 4 pp. 749-772 on the drift paradox. We consider the case of a
regime switching probabilistic model for a population of organisms living in a
one dimensional environment with drift towards an absorbing boundary of the
type introduced by Lutscher et al. (2005). In particular, the two regimes
consist of birth/death style demographics governing the evolution of the
immobile regime, and some form of advection-dispersion governing the evolution
of the mobile regime, together with a regime-switching mechanism linking the
two. In the present note it is shown for the regime-switching model, and in
contrast to the results in the afore cited work, for any finite advection
speed, no matter how large, there is a finite critical length of the domain
above which the population can persist.


title:
Highly comparative time-series analysis: The empirical structure of time
  series and their methods

abstract:
  The process of collecting and organizing sets of observations represents a
common theme throughout the history of science. However, despite the ubiquity
of scientists measuring, recording, and analyzing the dynamics of different
processes, an extensive organization of scientific time-series data and
analysis methods has never been performed. Addressing this, annotated
collections of over 35 000 real-world and model-generated time series and over
9000 time-series analysis algorithms are analyzed in this work. We introduce
reduced representations of both time series, in terms of their properties
measured by diverse scientific methods, and of time-series analysis methods, in
terms of their behaviour on empirical time series, and use them to organize
these interdisciplinary resources. This new approach to comparing across
diverse scientific data and methods allows us to organize time-series datasets
automatically according to their properties, retrieve alternatives to
particular analysis methods developed in other scientific disciplines, and
automate the selection of useful methods for time-series classification and
regression tasks. The broad scientific utility of these tools is demonstrated
on datasets of electroencephalograms, self-affine time series, heart beat
intervals, speech signals, and others, in each case contributing novel analysis
techniques to the existing literature. Highly comparative techniques that
compare across an interdisciplinary literature can thus be used to guide more
focused research in time-series analysis for applications across the scientific
disciplines.

categories: physics.data-an cs.CV physics.bio-ph q-bio.QM stat.ML


title: A "Strange" Vector-Valued Quantum Modular Form

abstract:
  Since their definition in 2010 by Zagier, quantum modular forms have been
connected to numerous different topics such as strongly unimodal sequences,
ranks, cranks, and asymptotics for mock theta functions near roots of unity.
These are functions that are not necessarily defined on the upper half plane
but a priori are defined only on a subset of $\Q$, and whose obstruction to
modularity is some analytically "nice" function. Motivated by Zagier's example
of the quantum modularity of Kontsevich's "strange" function $F(q)$, we revisit
work of Andrews, Jimenez-Urroz, and Ono to construct a natural vector-valued
quantum modular form whose components are similarly "strange".


title:
Fixed-point index, the Incompatibility Theorem, and torus
  parametrization

abstract:
  The fixed-point index of a homeomorphism of Jordan curves measures the number
of fixed-points, with multiplicity, of the extension of the homeomorphism to
the full Jordan domains in question. The now-classical Circle Index Lemma says
that the fixed-point index of a positive-orientation-preserving homeomorphism
of round circles is always non-negative. We begin by proving a generalization
of this lemma, to accommodate Jordan curves bounding domains which do not
disconnect each other. We then apply this generalization to give a new proof of
Schramm's Incompatibility Theorem, which was used by Schramm to give the first
proof of the rigidity of circle packings filling the complex and hyperbolic
planes. As an example application, we include outlines of proofs of these
circle packing theorems.
  We then introduce a new tool, the so-called torus parametrization, for
working with fixed-point index, which allows some problems concerning this
quantity to be approached combinatorially. We apply torus parametrization to
give the first purely topological proof of the following lemma: given two
positively oriented Jordan curves, one may essentially prescribe the images of
three points of one of the curves in the other, and obtain an
orientation-preserving homeomorphism between the curves, having non-negative
fixed-point index, which respects this prescription. This lemma is essential to
our proof of the Incompatibility Theorem.


title:
Faddeev calculation for breakup neutron-deuteron scattering at 14.1 MeV
  lab energy

abstract:
  A new computational method for solving the nucleon-deuteron breakup
scattering problem has been applied to study the inelastic neutron-deuteron
scattering on the basis of the configuration-space Faddeev equations. This
method is based on the spline-decomposition in the angular variable and on a
generalization of the Numerov method for the hyperradius. The
Merkuriev-Gignoux-Laverne approach has been generalized for arbitrary
nucleon-nucleon potentials and with an arbitrary number of partial waves.
Neutron-deuteron observables at the incident nucleon energy 14.1 MeV have been
calculated using the charge-independent AV14 nucleon-nucleon potential. Results
have been compared with those of other authors and with experimental
neutron-deuteron scattering data.


title: Discovery of four water masers in the Small Magellanic Cloud

abstract:
  We report the detection of four water masers within the Small Magellanic
Cloud (SMC); two discovered with the 70-m Tidbinbilla radio telescope, and two
discovered with the Australia Telescope Compact Array (ATCA). Precise positions
of all four masers have been derived from ATCA observations, and the
characteristics of each water maser have been monitored over a period of
several years. Sensitive observations towards two previously detected water
masers reported in the literature failed to detect any emission. The detected
water masers show evidence of higher levels of temporal variability than
equivalent Galactic sources, and one of the features associated with NGC346 IR1
shows an acceleration of 9.6 km/s yr^-1 over a 31 day period. Sensitive
targeted observations for methanol and OH masers failed to detect any
accompanying emission - in the case of methanol perhaps highlighting an under
abundance in the SMC, consistent with expectations due to lower metallicity.
  The water masers are both bright and compact making them excellent targets
for Very Long Baseline Interferometry (VLBI) observations, which can
potentially measure the proper motion of the SMC (~1 - 2 mas yr^-1) with
temporal baselines of ~12 months. Such observations would utilise sources
associated with only the current epoch of star formation and hence have several
advantages over alternative methods.


title:
Bell-state measurement and quantum teleportation using linear optics:
  two-photon pairs, entangled coherent states, and hybrid entanglement

abstract:
  We review and compare Bell-state measurement and quantum teleportation
schemes using linear optics with three different types of resources, i.e.,
two-photon pairs, entangled coherent states and hybrid entangled states.
Remarkably, perfect teleportation with linear optics is possible in principle
based on a hybrid approach that combines two-photon pairs and entangled
coherent states. It turns out that hybrid approach allows to perform Bell-state
measurement and local Pauli operations in a deterministic way, while it
requires photon number resolving measurements.


title:
Fluctuating surface-current formulation of radiative heat transfer:
  theory and applications

abstract:
  We describe a novel fluctuating-surface current formulation of radiative heat
transfer between bodies of arbitrary shape that exploits efficient and
sophisticated techniques from the surface-integral-equation formulation of
classical electromagnetic scattering. Unlike previous approaches to
non-equilibrium fluctuations that involve scattering matrices---relating
"incoming" and "outgoing" waves from each body---our approach is formulated in
terms of "unknown" surface currents, laying at the surfaces of the bodies, that
need not satisfy any wave equation. We show that our formulation can be applied
as a spectral method to obtain fast-converging semi-analytical formulas in
high-symmetry geometries using specialized spectral bases that conform to the
surfaces of the bodies (e.g. Fourier series for planar bodies or spherical
harmonics for spherical bodies), and can also be employed as a numerical method
by exploiting the generality of surface meshes/grids to obtain results in more
complicated geometries (e.g. interleaved bodies as well as bodies with sharp
corners). In particular, our formalism allows direct application of the
boundary-element method, a robust and powerful numerical implementation of the
surface-integral formulation of classical electromagnetism, which we use to
obtain results in new geometries, including the heat transfer between finite
slabs, cylinders, and cones.


title: X-ray Cluster Constraints on Non-Gaussianity

abstract:
  We report constraints on primordial non-Gaussianity from the abundance of
X-ray detected clusters. Our analytic prescription for adding non-Gaussianity
to the cluster mass function takes into account moments beyond the skewness,
and we demonstrate that those moments should not be ignored in most analyses of
cluster data. We constrain the amplitude of the skewness for two scenarios that
have different overall levels of non-Gaussianity, characterized by how
amplitudes of higher cumulants scale with the skewness. We find that current
data can constrain these one-parameter non-Gaussian models at a useful level,
but are not sensitive to adding further details of the corresponding inflation
scenarios. Combining cluster data with Cosmic Microwave Background constraints
on the cosmology and power spectrum amplitude, we find the dimensionless
skewness to be 1000*M3=-1+24-28 for one of our scaling scenarios, and
1000*M3=-4+/-7 for the other. These are the first constraints on
non-Gaussianity from Large Scale Structure that can be usefully applied to any
model of primordial non-Gaussianity. When applied to the standard local ansatz,
the constraint corresponds to fNL=-3+78-91. When applied to a model with a
local-shape bispectrum but higher cumulants that are relatively more important,
the amplitude of the local-shape bispectrum is constrained to be fNL=-14+22-21.
This sensitivity implies that cluster counts could be used to distinguish
qualitatively different models for the primordial fluctuations that have
identical bispectra. (Abstract Abridged.)


title:
On the communication complexity of sparse set disjointness and
  exists-equal problems

abstract:
  In this paper we study the two player randomized communication complexity of
the sparse set disjointness and the exists-equal problems and give matching
lower and upper bounds (up to constant factors) for any number of rounds for
both of these problems. In the sparse set disjointness problem, each player
receives a k-subset of [m] and the goal is to determine whether the sets
intersect. For this problem, we give a protocol that communicates a total of
O(k\log^{(r)}k) bits over r rounds and errs with very small probability. Here
we can take r=\log^{*}k to obtain a O(k) total communication \log^{*}k-round
protocol with exponentially small error probability, improving on the O(k)-bits
O(\log k)-round constant error probability protocol of Hastad and Wigderson
from 1997.
  In the exist-equal problem, the players receive vectors x,y\in [t]^n and the
goal is to determine whether there exists a coordinate i such that x_i=y_i.
Namely, the exists-equal problem is the OR of n equality problems. Observe that
exists-equal is an instance of sparse set disjointness with k=n, hence the
protocol above applies here as well, giving an O(n\log^{(r)}n) upper bound. Our
main technical contribution in this paper is a matching lower bound: we show
that when t=\Omega(n), any r-round randomized protocol for the exists-equal
problem with error probability at most 1/3 should have a message of size
\Omega(n\log^{(r)}n). Our lower bound holds even for super-constant r <=
\log^*n, showing that any O(n) bits exists-equal protocol should have \log^*n -
O(1) rounds.


title:
Teissier's problem on inequalities of nef divisors over an arbitrary
  field

abstract:
  Boucksom, Favre and Jonsson establish in [4] an analog of Diskant's
inequality in convex geometry for nef and big line bundles on a complete
algebraic variety over an algebraically closed field of characteristic zero
(Theorem F [4]), from which they deduce a solution (Theorem D [4]) to a problem
of Teissier (Problem B [29]) on proportionality of nef divisors. In this paper
we extend these results to a complete variety over an arbitrary field k.


title:
Probability Distribution Functions OF 12CO(J = 1-0) Brightness and
  Integrated Intensity in M51: The PAWS View

abstract:
  We analyse the distribution of CO brightness temperature and integrated
intensity in M51 at ~40 pc resolution using new CO data from the Plateau de
Bure Arcsecond Whirlpool Survey (PAWS). We present probability distribution
functions (PDFs) of the CO emission within the PAWS field, which covers the
inner 11 x 7 kpc of M51. We find variations in the shape of CO PDFs within
different M51 environments, and between M51 and M33 and the Large Magellanic
Cloud (LMC). Globally, the PDFs for the inner disk of M51 can be represented by
narrow lognormal functions that cover 1 to 2 orders of magnitude in CO
brightness and integrated intensity. The PDFs for M33 and the LMC are narrower
and peak at lower CO intensities. However, the CO PDFs for different dynamical
environments within the PAWS field depart from the shape of the global
distribution. The PDFs for the interarm region are approximately lognormal, but
in the spiral arms and central region of M51, they exhibit diverse shapes with
a significant excess of bright CO emission. The observed environmental
dependence of the shape of the CO PDFs is qualitatively consistent with changes
that would be expected if molecular gas in the spiral arms has a larger range
of average densities, gas temperatures and velocity fluctuations, though
further work is required to disentangle the importance of large-scale dynamical
effects versus star formation feedback in regulating these properties. We show
that the shape of the CO PDFs for different M51 environments is only weakly
related to global properties of the CO emission, but is strongly correlated
with some properties of the local giant molecular cloud (GMC) and young stellar
cluster populations. For galaxies with strong spiral structure such as M51, our
results indicate that galactic-scale dynamical processes play a significant
role in the formation and evolution of GMCs and stellar clusters.(abridged)


title: A generalized asynchronous computability theorem

abstract:
  We consider the models of distributed computation defined as subsets of the
runs of the iterated immediate snapshot model. Given a task $T$ and a model
$M$, we provide topological conditions for $T$ to be solvable in $M$. When
applied to the wait-free model, our conditions result in the celebrated
Asynchronous Computability Theorem (ACT) of Herlihy and Shavit. To demonstrate
the utility of our characterization, we consider a task that has been shown
earlier to admit only a very complex $t$-resilient solution. In contrast, our
generalized computability theorem confirms its $t$-resilient solvability in a
straightforward manner.


title: Unicyclic Graphs with equal Laplacian Energy

abstract:
  We introduce a new operation on a class of graphs with the property that the
Laplacian eigenvalues of the input and output graphs are related. Based on this
operation, we obtain a family of order (square root of n) noncospectral
unicyclic graphs on n vertices with the same Laplacian energy.


title:
Alternating minimal energy methods for linear systems in higher
  dimensions. Part II: Faster algorithm and application to nonsymmetric systems

abstract:
  In this paper we accomplish the development of the fast rank-adaptive solver
for tensor-structured symmetric positive definite linear systems in higher
dimensions. In [arXiv:1301.6068] this problem is approached by alternating
minimization of the energy function, which we combine with steps of the basis
expansion in accordance with the steepest descent algorithm. In this paper we
combine the same steps in such a way that the resulted algorithm works with one
or two neighboring cores at a time. The recurrent interpretation of the
algorithm allows to prove the global convergence and to estimate the
convergence rate. We also propose several strategies, both rigorous and
heuristic, to compute new subspaces for the basis enrichment in a more
efficient way. We test the algorithm on a number of high-dimensional problems,
including the non-symmetrical Fokker-Planck and chemical master equations, for
which the efficiency of the method is not fully supported by the theory. In all
examples we observe a convincing fast convergence and high efficiency of the
proposed method.


title:
CLASH: Complete Lensing Analysis of the Largest Cosmic Lens MACS
  J0717.5+3745 and Surrounding Structures

abstract:
  The galaxy cluster MACS J0717.5+3745 (z=0.55) is the largest known cosmic
lens, with complex internal structures seen in deep X-ray, Sunyaev-Zel'dovich
effect and dynamical observations. We perform a combined weak and strong
lensing analysis with wide-field BVRi'z' Subaru/Suprime-Cam observations and
16-band Hubble Space Telescope observations taken as part of the Cluster
Lensing And Supernova survey with Hubble (CLASH). We find consistent weak
distortion and magnification measurements of background galaxies, and combine
these signals to construct an optimally estimated radial mass profile of the
cluster and its surrounding large-scale structure out to 5 Mpc/h. We find
consistency between strong-lensing and weak-lensing in the region where these
independent data overlap, <500 kpc/h. The two-dimensional weak-lensing map
reveals a clear filamentary structure traced by distinct mass halos. We model
the lensing shear field with 9 halos, including the main cluster, corresponding
to mass peaks detected above 2.5\sigma_\kappa. The total mass of the cluster as
determined by the different methods is M_{vir}=(2.8\pm0.4) \times 10^15 M_sun.
Although this is the most massive cluster known at z>0.5, in terms of extreme
value statistics we conclude that the mass of MACS J0717.5+3745 by itself is
not in serious tension with LambdaCDM, representing only a ~2{\sigma} departure
above the maximum simulated halo mass at this redshift.


title:
Indecomposable modules for the dual immaculate basis of quasi-symmetric
  functions

abstract:
  We construct indecomposable modules for the 0-Hecke algebra whose
characteristics are the dual immaculate basis of the quasi-symmetric functions.


title:
Cyclic stabilizers and infinitely many hyperbolic orbits for
  pseudogroups on (C,0)

abstract:
  Consider a pseudogroup on (C,0) generated by two local diffeomorphisms having
analytic conjugacy classes a priori fixed in Diff(C,0). We show that a generic
pseudogroup as above is such that every point has (possibly trivial) cyclic
stabilizer. It also follows that these generic groups possess infinitely many
hyperbolic orbits. This result possesses several applications to the topology
of leaves of foliations and we shall explicitly describe the case of nilpotent
foliations associated to Arnold's singularities of type A^{2n+1}.


title:
On Euler's "Misleading Induction", Andrews' "Fix", and How to Fully
  Automate them

abstract:
  One of the greatest experimental mathematicians of all time was also one of
the greatest mathematicians of all time, the great Leonhard Euler. Usually he
had an uncanny intuition on how many "special cases" one needs before one can
formulate a plausible conjecture, but one time he was "almost fooled", only to
find out that his conjecture was premature.
  In 1990, George Andrews found a way to "correct" Euler. Here we show how to
generate, AUTOMATICALLY, rigorously-proved Euler-Andrews Style formulas, that
enables one to generate Euler-style "cautionary tales" about the "danger" of
using naive empirical induction. Ironically, the way we prove the Andrews-style
corrections is empirical! But in order to turn the empirical proof into a
full-fledged rigorous proof, we must make sure that we check sufficiently many
(but still not that many!) special cases.


title: One conjecture about size of Sidon sets

abstract:
  We prove that maximal cardinality of the Sidon set from $[n]$ exceeds
$\sqrt{n}


title:
Ab-initio prediction of magnetoelectricity in infinite-layer CaFeO2 and
  MgFeO2

abstract:
  Density functional based simulations are employed to explore magnetoelectric
effects in iron-based oxides, showing a unique layered structure. We
theoretically predict CaFeO2 to be a promising magnetoelectric, showing
magnetically-controlled large electric polarization, possibly even above room
temperature. The cross coupling between magnetic and dipolar degrees of freedom
needs, as main ingredients, Fe-site spin-orbit coupling and a spin-dependent O
p - Fe d hybridization, along with structural constraints related to the
non-centrosymmetric point group and the peculiar geometry characterized by
"flattened" FeO4 tetrahedrons. In order to enhance magnetoelectric effects, we
performed a materials-design leading to a novel and optimized system, MgFeO2,
where the larger O4 tetrahedral distortion leads to a stronger polarization.


title:
Strain-induced enhancement of plasma dispersion effect and free-carrier
  absorption in SiGe optical modulators

abstract:
  The plasma dispersion effect and free-carrier absorption are widely used for
changing refractive index and absorption coefficient in Si-based optical
modulators. However, these free-carrier effects in Si are not large enough for
making the footprint of the Si modulators small. Here, we have theoretically
and experimentally investigated the enhancement of the plasma dispersion effect
and free-carrier absorption by strain-induced mass modulation in
silicon-germanium (SiGe). The application of compressive strain to SiGe reduces
the conductivity hole mass, resulting in the enhanced free-carrier effects.
Thus, the strained SiGe-based optical modulator exhibits more than twice
modulation efficiency as large as that of the Si modulator. To the best of our
knowledge, it is the first demonstration of the enhanced free-carrier effects
in strained SiGe at the near-infrared telecommunication wavelength. The
strain-induced enhancement technology for the free-carrier effects is expected
to boost the modulation efficiency of the most Si-based optical modulators
thanks to high complementary metal-oxide-semiconductor (CMOS) compatibility.


title: Law of Large Numbers for Monotone Convolution

abstract:
  Using martingale convergence theorem, we prove a law of large numbers for
monotone convolutions
$\mu_{1}\triangleright\mu_{2}\triangleright\cdots\triangleright\mu_{n}$, where
$\mu_{j}$'s are probability laws on $\mathbb{R}$ with finite variances but not
required to be identical.


title:
Genome wide identification of regulatory networks associated with
  general cognitive ability using a normalized alignment free similarity
  measure of promoter regions

abstract:
  We show that a normalized alignment free similarity measure, called D2z, can
be used to detect potential regulatory relations for gene sets when little is
known about the regulatory elements involved. One scenario where such gene sets
arise is genome wide association studies (GWAS). In this work we consider a
gene set from a GWAS on childhood general cognitive ability. We build a
co-regulation network for the GWAS genes based on the D2z scores, which shows
potential co-regulatory relationships between the genes as well as predict
additional genes that are likely to be part of the network. We found that the
set of the predicted genes is enriched in genes associated with mental
retardation and GO terms such as synapse and neuron development. In particular,
we found strong evidence of regulatory connection between the GWAS genes and
CHL1, a gene known to be involved in mental retardation.


title: Majorisation and Kadison's Carpenter's Theorem

abstract:
  We discuss Kadison's Carpenter's Theorems in the context of majorisation, and
we offer a new proof of his "Theorem 15", that characterizes the set of
diagonals of orthogonal projections.


title: Shadow Detection: A Survey and Comparative Evaluation of Recent Methods

abstract:
  This paper presents a survey and a comparative evaluation of recent
techniques for moving cast shadow detection. We identify shadow removal as a
critical step for improving object detection and tracking. The survey covers
methods published during the last decade, and places them in a feature-based
taxonomy comprised of four categories: chromacity, physical, geometry and
textures. A selection of prominent methods across the categories is compared in
terms of quantitative performance measures (shadow detection and discrimination
rates, colour desaturation) as well as qualitative observations. Furthermore,
we propose the use of tracking performance as an unbiased approach for
determining the practical usefulness of shadow detection methods. The
evaluation indicates that all shadow detection approaches make different
contributions and all have individual strength and weaknesses. Out of the
selected methods, the geometry-based technique has strict assumptions and is
not generalisable to various environments, but it is a straightforward choice
when the objects of interest are easy to model and their shadows have different
orientation. The chromacity based method is the fastest to implement and run,
but it is sensitive to noise and less effective in low saturated scenes. The
physical method improves upon the accuracy of the chromacity method by adapting
to local shadow models, but fails when the spectral properties of the objects
are similar to that of the background. The small-region texture based method is
especially robust for pixels whose neighbourhood is textured, but may take
longer to implement and is the most computationally expensive. The large-region
texture based method produces the most accurate results, but has a significant
computational load due to its multiple processing steps.


title: Global rigidity of higher rank Anosov algebraic actions

abstract:
  We show that all $C^\infty$ Anosov $Z^r$-actions on tori and nilmanifolds
without rank-one factor actions are, up to $C^\infty$ conjugacy, actions by
automorphisms.


title: A Review on P2P Video Streaming

abstract:
  The main objective of this article is to provide an overview of P2P based
Video-on-Demand and live streaming services. The article starts with an
introduction to media streaming and its simplified architecture. Various
solutions offering video streaming in the context of widespread usage of
Internet are discussed. This is followed by a short introduction to P2P
networks and its applications. A broad discussion on various P2P streaming
schemes and P2P streaming applications are the main focus of this chapter.
Finally, the security issues and solutions for P2P video streaming are
discussed briefly.


title:
Asymptotic Spectral Distributions of Distance $k$-Graphs of Cartesian
  Product Graphs

abstract:
  Let $G$ be a finite connected graph on two or more vertices and $G^{[N,k]}$
the distance $k$-graph of the $N$-fold Cartesian power of $G$. For a fixed
$k\ge1$, we obtain explicitly the large $N$ limit of the spectral distribution
(the eigenvalue distribution of the adjacency matrix) of $G^{[N,k]}$. The limit
distribution is described in terms of the Hermite polynomials. The proof is
based on asymptotic combinatorics along with quantum probability theory.


title: Markov degree of the Birkhoff model

abstract:
  We prove the conjecture by Diaconis and Eriksson (2006) that the Markov
degree of the Birkhoff model is three. In fact, we prove the conjecture in a
generalization of the Birkhoff model, where each voter is asked to rank a fixed
number, say r, of candidates among all candidates. We also give an exhaustive
characterization of Markov bases for small r.


title: Sparse FGLM algorithms

abstract:
  Given a zero-dimensional ideal I in K[x1,...,xn] of degree D, the
transformation of the ordering of its Groebner basis from DRL to LEX is a key
step in polynomial system solving and turns out to be the bottleneck of the
whole solving process. Thus it is of crucial importance to design efficient
algorithms to perform the change of ordering.
  The main contributions of this paper are several efficient methods for the
change of ordering which take advantage of the sparsity of multiplication
matrices in the classical FGLM algorithm. Combing all these methods, we propose
a deterministic top-level algorithm that automatically detects which method to
use depending on the input. As a by-product, we have a fast implementation that
is able to handle ideals of degree over 40000. Such an implementation
outperforms the Magma and Singular ones, as shown by our experiments.
  First for the shape position case, two methods are designed based on the
Wiedemann algorithm: the first is probabilistic and its complexity to complete
the change of ordering is O(D(N1+nlog(D))), where N1 is the number of nonzero
entries of a multiplication matrix; the other is deterministic and computes the
LEX Groebner basis of the radical of I via Chinese Remainder Theorem. Then for
the general case, the designed method is characterized by the
Berlekamp-Massey-Sakata algorithm from Coding Theory to handle the
multi-dimensional linearly recurring relations. Complexity analyses of all
proposed methods are also provided.
  Furthermore, for generic polynomial systems, we present an explicit formula
for the estimation of the sparsity of one main multiplication matrix, and prove
its construction is free. With the asymptotic analysis of such sparsity, we are
able to show for generic systems the complexity above becomes $O(\sqrt{6/n \pi}
D^{2+(n-1)/n}})$.


title: Total Representations

abstract:
  Almost all representations considered in computable analysis are partial. We
provide arguments in favor of total representations (by elements of the Baire
space). Total representations make the well known analogy between numberings
and representations closer, unify some terminology, simplify some technical
details, suggest interesting open questions and new invariants of topological
spaces relevant to computable analysis.


title: Transformation optics for cavity array metamaterials

abstract:
  Cavity array metamaterials (CAMs), composed of optical microcavities in a
lattice coupled via tight-binding interactions, represent a novel architecture
for engineering metamaterials. Since the size of the CAMs' constituent elements
are commensurate with the operating wavelength of the device, it cannot
directly utilise classical transformation optics in the same way as traditional
metamaterials. By directly transforming the internal geometry of the system,
and locally tuning the permittivity between cavities, we provide an alternative
framework suitable for tight-binding implementations of metamaterials. We
develop a CAM-based cloak as the case study.


title: The angle of large values of $L$-functions

abstract:
  We prove omega results for the central value of $L$-functions with the
further condition that the angle is also constrained.


title:
Computation and Universality: Class IV versus Class III Cellular
  Automata

abstract:
  This paper examines the claim that cellular automata (CA) belonging to Class
III (in Wolfram's classification) are capable of (Turing universal)
computation. We explore some chaotic CA (believed to belong to Class III)
reported over the course of the CA history, that may be candidates for
universal computation, hence spurring the discussion on Turing universality on
both Wolfram's classes III and IV.


title: Benchtop Fabrication of Memristive Atomic Switch Networks

abstract:
  Recent advances in nanoscale science and technology provide possibilities to
directly self-assemble and integrate functional circuit elements within the
wiring scheme of devices with potentially unique architectures. Electroionic
resistive switching circuits comprising highly interconnected fractal
electrodes and metal-insulator-metal interfaces, known as atomic switch
networks, have been fabricated using simple benchtop techniques including
solution-phase electroless deposition. These devices are shown to activate
through a bias-induced forming step that produces the frequency dependent,
nonlinear hysteretic switching expected for gapless-type atomic switches and
memristors. By eliminating the need for complex lithographic methods, such an
approach toward device fabrication provides a more accessible platform for the
study of ionic resistive switches and memristive systems.


title:
Nonlocalized Clustering: A New Concept in Nuclear Cluster Structure
  Physics

abstract:
  We investigate the $\alpha$+\oo\ cluster structure in the inversion-doublet
band ($K^\pi=0_{1}^\pm$) states of \nene\ with an angular-momentum-projected
version of the Tohsaki-Horiuchi-Schuck-R\"{o}pke (THSR) wave function, which
was successful "in its original form" for the description of, e.g., the famous
Hoyle state. In contrast with the traditional view on clusters as localized
objects, especially in inversion doublets, we find that these {\it single} THSR
wave functions, which are based on the concept of nonlocalized clustering, can
well describe the $K^{\pi}=0_1^-$ band and the $K^{\pi}=0_1^+$ band. For
instance, they have 99.98% and 99.87% squared overlaps for $1^-$ and $3^- $
states (99.29%, 98.79% and 97.75% for $0^+, 2^+$ and $4^+$ states),
respectively, with the corresponding exact solution of the $\alpha$+\oo\
resonating group method. These astounding results shed a completely new light
on the physics of low energy nuclear cluster states in nuclei: The clusters are
nonlocalized and move around in the whole nuclear volume, only avoiding mutual
overlap due to the Pauli blocking effect.


title: Fourier sparsity, spectral norm, and the Log-rank conjecture

abstract:
  We study Boolean functions with sparse Fourier coefficients or small spectral
norm, and show their applications to the Log-rank Conjecture for XOR functions
f(x\oplus y) --- a fairly large class of functions including well studied ones
such as Equality and Hamming Distance. The rank of the communication matrix M_f
for such functions is exactly the Fourier sparsity of f. Let d be the F2-degree
of f and D^CC(f) stand for the deterministic communication complexity for
f(x\oplus y). We show that 1. D^CC(f) = O(2^{d^2/2} log^{d-2} ||\hat f||_1). In
particular, the Log-rank conjecture holds for XOR functions with constant
F2-degree. 2. D^CC(f) = O(d ||\hat f||_1) = O(\sqrt{rank(M_f)}\logrank(M_f)).
We obtain our results through a degree-reduction protocol based on a variant of
polynomial rank, and actually conjecture that its communication cost is already
\log^{O(1)}rank(M_f). The above bounds also hold for the parity decision tree
complexity of f, a measure that is no less than the communication complexity
(up to a factor of 2).
  Along the way we also show several structural results about Boolean functions
with small F2-degree or small spectral norm, which could be of independent
interest. For functions f with constant F2-degree: 1) f can be written as the
summation of quasi-polynomially many indicator functions of subspaces with
\pm-signs, improving the previous doubly exponential upper bound by Green and
Sanders; 2) being sparse in Fourier domain is polynomially equivalent to having
a small parity decision tree complexity; 3) f depends only on polylog||\hat
f||_1 linear functions of input variables. For functions f with small spectral
norm: 1) there is an affine subspace with co-dimension O(||\hat f||_1) on which
f is a constant; 2) there is a parity decision tree with depth O(||\hat f||_1
log ||\hat f||_0).


title: Acylindrically hyperbolic groups

abstract:
  We say that a group $G$ is acylindrically hyperbolic if it admits a
non-elementary acylindrical action on a hyperbolic space. We prove that the
class of acylindrically hyperbolic groups coincides with many other classes
studied in the literature, e.g., the class $C_{geom}$ introduced by Hamenstadt,
the class of groups admitting a non-elementary weakly properly discontinuous
action on a hyperbolic space in the sense of Bestvina and Fujiwara, and the
class of groups with hyperbolically embedded subgroups studied by Dahmani,
Guirardel, and the author. We also record some basic results about
acylindrically hyperbolic groups for future use.


title: Solving Linear Programming with Constraints Unknown

abstract:
  What is the value of input information in solving linear programming? The
celebrated ellipsoid algorithm tells us that the full information of input
constraints is not necessary; the algorithm works as long as there exists an
oracle that, on a proposed candidate solution, returns a violation in the
format of a separating hyperplane. Can linear programming still be efficiently
solved if the returned violation is in other formats?
  We study this question in a trial-and-error framework: there is an oracle
that, upon a proposed solution, returns the index of a violated constraint
(with the content of the constraint still hidden). When more than one
constraint is violated, two variants in the model are investigated. (1) The
oracle returns the index of a "most violated" constraint, measured by the
Euclidean distance of the proposed solution and the half-spaces defined by the
constraints. In this case, the LP can be efficiently solved. (2) The oracle
returns the index of an arbitrary (i.e., worst-case) violated constraint. In
this case, we give an algorithm with running time exponential in the number of
variables. We then show that the exponential dependence on n is unfortunately
necessary even for the query complexity. These results put together shed light
on the amount of information that one needs in order to solve a linear program
efficiently.
  The proofs of the results employ a variety of geometric techniques, including
McMullen's Upper Bound Theorem, the weighted spherical Voronoi diagram, and the
furthest Voronoi diagram. In addition, we give an alternative proof to a
conjecture of L\'aszl\'o Fejes T\'oth on bounding the number of disconnected
components formed by the union of m convex bodies in R^n. Our proof, inspired
by the Gauss-Bonnet Theorem in global differential geometry, is independent of
the known and reveals more clear insights into the problem and the bound.


title: Matter Matters: Unphysical Properties of the Rh = ct Universe

abstract:
  It is generally agreed that there is matter in the universe and, in this
paper, we show that the existence of matter is extremely problematic for the
proposed Rh = ct universe. Considering a dark energy component with an equation
of state of w=-1/3, it is shown that the presence of matter destroys the strict
expansion properties that define the evolution of Rh = ct cosmologies,
distorting the observational properties that are touted as its success. We
further examine whether an evolving dark energy component can save this form of
cosmological expansion in the presence of matter by resulting in an expansion
consistent with a mean value of <w> = -1/3, finding that the presence of mass
requires unphysical forms of the dark energy component in the early universe.
We conclude that matter in the universe significantly limits the fundamental
properties of the Rh = ct cosmology, and that novel, and unphysical, evolution
of the matter component would be required to save it. Given this, Rh = ct
cosmology is not simpler or more accurate description of the universe than
prevailing cosmological models, and its presentation to date possesses
significant flaws.


title:
The global solar magnetic field -- identification of travelling,
  long-lived ripples

abstract:
  We have examined the global structure of the solar magnetic field using data
from the FeI spectral line at {\lambda}5250.2{\AA} obtained at the 150-foot
tower telescope at the Mt. Wilson Observatory (MWO). For each point on the
solar surface, we find the value of the magnetic field in the meridional plane,
Bm, by averaging over all available observations using a cosine weighting
method. We have revised our cosine weighting method by now taking into account
more fully the highest latitude geometry. We use the annual variation in the
latitude of the disk center, b0, to deduce the tilt angle of the field relative
to the local vertical so that we can find the radial component of the field, Br
from Bm. We find this tilt angle to be small except for a near-polar zone where
a tilt-angle model can reduce the annual variation. The reduced annual
variation in the deduced Br allows us to study dBr/dt and associated deviations
in Br from a smoothed Br with a smoothing width of 2.5 years. These functions
make evident the presence of small amplitude (3 to 5 gauss) but spatially
coherent ripples with a semi-regular periodicity of 1 to 3 years. At any given
time the half-wavelength (peak-to-trough) is between 15 and 30 degrees of
latitude. These patterns are ubiquitous and in many cases drift from near the
equator to the poles over a time period of roughly 2 years. The drift rate
pattern is not compatible with simple advection.


title: Fast Approximate L_infty Minimization: Speeding Up Robust Regression

abstract:
  Minimization of the $L_\infty$ norm, which can be viewed as approximately
solving the non-convex least median estimation problem, is a powerful method
for outlier removal and hence robust regression. However, current techniques
for solving the problem at the heart of $L_\infty$ norm minimization are slow,
and therefore cannot scale to large problems. A new method for the minimization
of the $L_\infty$ norm is presented here, which provides a speedup of multiple
orders of magnitude for data with high dimension. This method, termed Fast
$L_\infty$ Minimization, allows robust regression to be applied to a class of
problems which were previously inaccessible. It is shown how the $L_\infty$
norm minimization problem can be broken up into smaller sub-problems, which can
then be solved extremely efficiently. Experimental results demonstrate the
radical reduction in computation time, along with robustness against large
numbers of outliers in a few model-fitting problems.


title:
A simulation of the cluster structures in Ge-Se vitreous chalcogenide
  semiconductors

abstract:
  A structure of germanium selenide glasses is simulated by the featured
clusters built from the tetrahedral GeSe4 units up to the clusters with six
germanium atoms (Ge6Se16H4 and Ge6Se16H8). Quantum chemical calculations at the
DFT level with effective core potentials for Ge and Se atoms for the clusters
of different composition reveal their relative stability and optical
properties.


title: Effects of Penetrative Convection on Solar Dynamo

abstract:
  Spherical solar dynamo simulations are performed. Self-consistent, fully
compressible magnetohydrodynamic system with a stably stratified layer below
the convective envelope is numerically solved with a newly developed simulation
code based on the Yin-Yang grid. The effects of penetrative convection are
studied by comparing two models with and without the stable layer. The
differential rotation profile in both models is reasonably solar-like with
equatorial acceleration. When considering the penetrative convection, a
tachocline-like shear layer is developed and maintained beneath the convection
zone without assuming any forcing. While turbulent magnetic field becomes
predominant in the region where the convective motion is vigorous, mean-field
component is preferentially organized in the region where the convective motion
is less vigorous. Especially in the stable layer, the strong large-scale field
with a dipole symmetry is spontaneously built up. The polarity reversal of the
mean-field component takes place globally and synchronously throughout the
system regardless the presence of the stable layer. Our results suggest that
the stably stratified layer is a key component for organizing the large-scale
strong magnetic field, but is not essential for the polarity reversal.


title: Next-to-Leading Order W + 5-Jet Production at the LHC

abstract:
  We present next-to-leading order QCD predictions for the total cross section
and for a comprehensive set of transverse-momentum distributions in W + 5-jet
production at the Large Hadron Collider. We neglect the small contributions
from subleading-color virtual terms, top quarks and some terms containing four
quark pairs. We also present ratios of total cross sections, and use them to
obtain an extrapolation formula to an even larger number of jets. We include
the decay of the $W$ boson into leptons. This is the first such computation
with six final-state vector bosons or jets. We use BlackHat together with
SHERPA to carry out the computation.


title:
Dynamic environment coupling induce synchronized states in coupled
  time-delayed electronic circuits

abstract:
  We experimentally demonstrate the occurrence of various synchronized states
in coupled piece-wise linear time-delayed electronic circuits using dynamic
environment coupling where the environment has its own intrinsic dynamics via
feedback from the circuits. We carry out these experiments in two different
coupling configurations, namely mutual and subsystem coupling configurations.
Depending upon the coupling strength and the nature of feedback, we observe a
transition from nonsynchronization to complete synchronization via phase
synchronization and from nonsynchronization to inverse synchronization via
inverse-phase synchronization between the circuits in hyperchaotic regime.
Snapshots of the time evolution, phase projection plots and localized sets of
the circuits as observed experimentally from the oscilloscope, along with
supporting numerical simulations confirm the existence of different
synchronized states. Further, the transition to different synchronized states
can be verified from the changes in the largest Lyapunov exponents, Correlation
of Probability of Recurrence and Correlation Coefficient as a function of the
coupling strength. We present a detailed linear stability analysis and obtain
conditions for different synchronized states.


title: Entropy and the fourth moment phenomenon

abstract:
  We develop a new method for bounding the relative entropy of a random vector
in terms of its Stein factors. Our approach is based on a novel representation
for the score function of smoothly perturbed random variables, as well as on
the de Bruijn's identity of information theory. When applied to sequences of
functionals of a general Gaussian field, our results can be combined with the
Carbery-Wright inequality in order to yield multidimensional entropic rates of
convergence that coincide, up to a logarithmic factor, with those achievable in
smooth distances (such as the 1-Wasserstein distance). In particular, our
findings settle the open problem of proving a quantitative version of the
multidimensional fourth moment theorem for random vectors having chaotic
components, with explicit rates of convergence in total variation that are
independent of the order of the associated Wiener chaoses. The results proved
in the present paper are outside the scope of other existing techniques, such
as for instance the multidimensional Stein's method for normal approximations.


title: A combinatorial analysis of Severi degrees

abstract:
  Based on results by Brugall\'e and Mikhalkin, Fomin and Mikhalkin give
formulas for computing classical Severi degrees $N^{d, \delta}$ using long-edge
graphs. In 2012, Block, Colley and Kennedy considered the logarithmic version
of a special function associated to long-edge graphs appeared in
Fomin-Mikhalkin's formula, and conjectured it to be linear. They have since
proved their conjecture. At the same time, motivated by their conjecture, we
consider a special multivariate function associated to long-edge graphs that
generalizes their function. The main result of this paper is that the
multivariate function we define is always linear. A special case of our result
gives an independent proof of Block-Colley-Kennedy's conjecture.
  The first application of our linearity result is that by applying it to
classical Severi degrees, we recover quadraticity of $Q^{d, \delta}$ and a
bound $\delta$ for the threshold of polynomiality of $N^{d, \delta}.$ Next, in
joint work with Osserman, we apply the linearity result to a special family of
toric surfaces and obtain universal polynomial results having connections to
the G\"ottsche-Yau-Zaslow formula. As a result, we provide combinatorial
formulas for the two unidentified power series $B_1(q)$ and $B_2(q)$ appearing
in the G\"ottsche-Yau-Zaslow formula.
  The proof of our linearity result is completely combinatorial. We define
$\tau$-graphs which generalize long-edge graphs, and a closely related family
of combinatorial objects we call $(\tau, n)$-words. By introducing height
functions and a concept of irreducibility, we describe ways to decompose
certain families of $(\tau, n)$-words into irreducible words, which leads to
the desired results.


title:
All-electrically reading out and initializing topological qubits with
  quantum dots

abstract:
  We analyze the reading and initialization of a topological qubit encoded by
Majorana fermions in one-dimensional semiconducting nanowires, weakly coupled
to a single level quantum dot (QD). It is shown that when the Majorana fermions
are fused by tuning gate voltage, the topological qubit can be read out
directly through the occupation of the QD in an energy window. The
initialization of the qubit can also be realized via adjusting the gate voltage
on the QD, with the total fermion parity conserved. As a result, both reading
and initialization processes can be achieved in an all-electrical way.


title:
The AT20G view of Swift/BAT selected AGN: high-frequency radio waves
  meet hard X-rays

abstract:
  We cross-matched the 6-year Swift/Burst Alert Telescope (BAT) survey of
active galactic nuclei (AGN) with the AT20G radio survey of the southern sky,
which is one of the largest high-frequency radio surveys available. With these
data we investigated the possible correlation between the radio and the X-ray
emission at the highest radio and X-ray frequencies. We found 37 AGN with a
high probability of association (>80 per cent), among which 19 are local
Seyfert galaxies (with median redshift z = 0.03) and 18 blazars. We found that
\approx 20 per cent of the AGN detected in hard X-rays are also bright radio
sources at 20 GHz, but the apparent correlation between the radio and hard
X-ray luminosity is completely driven by the different median redshifts of the
two subgroups of AGN. When we consider only the local Seyfert sample we find no
evidence of a correlation between their 20 GHz and 15-55 keV power. Therefore
it appears that at high frequencies the radio-X connection, which had been
previously observed at lower frequencies, disappears. The disappearance of the
radio-X correlation at high radio and X-ray frequencies could be tested through
Very Long Baseline Interferometry and the use of the Nuclear Spectroscopic
Telescope Array (NuSTAR) satellite.


title:
On the Radii of Brown Dwarfs Measured with AKARI Near-Infrared
  Spectroscopy

abstract:
  We derive the radii of 16 brown dwarfs observed by AKARI using their
parallaxes and the ratios of observed to model fluxes. We find that the brown
dwarf radius ranges between 0.64-1.13 RJ with an average radius of 0.83 RJ. We
find a trend in the relation between radii and Teff; the radius is at a minimum
at Teff~1600 K, which corresponds to the spectral types of mid-to late-L. The
result is interpreted by a combination of radius-mass and radius-age relations
that are theoretically expected for brown dwarfs older than 10^8 yr.


title:
Teraherz photomixing using plasma resonances in double-graphene layer
  structures

abstract:
  We propose the concept of terahertz (THz) photomixing enabled by the
interband electron transitions due to the absorption of modulated optical
radiation in double-graphene layer (double-GL) structures and the resonant
excitation of plasma oscillations. Using the developed double-GL photomixer
(DG-PM) model, we describe its operation and calculate the device
characteristics. The output power of the THz radiation exhibits sharp resonant
peaks at the plasmonic resonant frequencies. The peak powers markedly exceed
the output powers at relatively low frequencies. Due to relatively high quantum
efficiency of optical absorption in GLs and short inter-GL transit time, the
proposed DG-PM operating in the resonant plasma oscillation regime can surpass
the photomixers based on the standard heterostructures .


title:
Molecular and atomic gas in the young TeV \gamma-ray SNRs RX
  J1713.7-3946 and RX J0852.0-4622; evidence for the hadronic production of
  \gamma-rays

abstract:
  The interstellar molecular clouds are the site of star formation and also the
target for the cosmic ray protons to produce \gamma-rays via the hadronic
process. The interstellar atomic gas is enveloping the molecular clouds and may
also be dense enough to affect the \gamma-ray production. In this Chapter, some
of the basic properties of the interstellar gas both in molecular and atomic
forms will be reviewed. Then, it is presented that two young TeV \gamma-ray
SNRs, RX J1713.7-3946 and RX J0852.0-4622, show good spatial correspondence
between the \gamma-rays and the interstellar protons. The good spatial
correspondence provides a support for the hadronic origin of the \gamma-rays in
these SNRs. It is emphasized that both molecular and atomic hydrogen plays a
role as targets for cosmic ray (CR) protons. The clumpy distribution of the
target interstellar medium (ISM) protons is crucial in the interaction of the
supernova shocks with the ISM, whereas models with uniform ISM distribution are
not viable. Finally, it is suggested that the dense atomic gas without
molecules may occupy the dominant part of the dark gas in the local ISM.


title:
Classification of Human Epithelial Type 2 Cell Indirect
  Immunofluoresence Images via Codebook Based Descriptors

abstract:
  The Anti-Nuclear Antibody (ANA) clinical pathology test is commonly used to
identify the existence of various diseases. A hallmark method for identifying
the presence of ANAs is the Indirect Immunofluorescence method on Human
Epithelial (HEp-2) cells, due to its high sensitivity and the large range of
antigens that can be detected. However, the method suffers from numerous
shortcomings, such as being subjective as well as time and labour intensive.
Computer Aided Diagnostic (CAD) systems have been developed to address these
problems, which automatically classify a HEp-2 cell image into one of its known
patterns (eg., speckled, homogeneous). Most of the existing CAD systems use
handpicked features to represent a HEp-2 cell image, which may only work in
limited scenarios. In this paper, we propose a cell classification system
comprised of a dual-region codebook-based descriptor, combined with the Nearest
Convex Hull Classifier. We evaluate the performance of several variants of the
descriptor on two publicly available datasets: ICPR HEp-2 cell classification
contest dataset and the new SNPHEp-2 dataset. To our knowledge, this is the
first time codebook-based descriptors are applied and studied in this domain.
Experiments show that the proposed system has consistent high performance and
is more robust than two recent CAD systems.


title:
On the inner structure of a permutation: Bicolored Partitions and
  Eulerians, Trees and Primitives

abstract:
  We present a bijective algorithm with which an arbitrary permutation
decomposes canonically into elementary blocks which we call families, which are
sets with a specified number of ascents and descents. We show that families,
arranged in an arbitrary order in a sequence, are in bijection with
permutations. The permutation decomposes canonically, by inserting parentheses,
into a tree having as nodes a class of permutations which we call primitive.
Primitive permutations can be assembled from very simple data. The data for the
trees into which a permutation decomposes can be written in a form similar to
the decimal classification of a library. We axiomatize that data. It has a
structure very different from the permutation which it encodes, with shuffles
and pairings instead of reorderings. These structures are similar to the
fundamental processes in quantum field theory. Our main bijective structure
algorithm gives explicit, additive multinomial formulae for the number of
permutations with given sets of elements under and over the diagonal, or with
given ascent and descent values. The multinomial expressions obtained this way
give a new class of bicolored set statistics, between set partitions and set
compositions, called shifted multinomials. These provide for the first time
additive multinomial expressions for Eulerian numbers and derangements, as part
of a sequence of new combinatorial objects. These multinomial expressions
satisfy inductive relations involving only immediate neighbors, similar to the
relations satisfied by the Eulerian numbers.


title: Driving--induced bistability in coupled chaotic attractors

abstract:
  We examine the effects of symmetry--preserving and breaking interactions in a
drive--response system where the response has an invariant symmetry in the
absence of the drive. Subsequent to the onset of generalized synchronization,
we find that there can be more than one stable attractor. Numerical, as well as
analytical results establish the presence of phase synchrony in such coexisting
attractors. These results are robust to external noise.


title:
QCD magnetic susceptibility at finite temperature beyond the chiral
  limit

abstract:
  We investigate the QCD magnetic susceptibility chi_q for flavor SU(2) at
finite temperature (T) beyond the chiral limit, using the liquid instanton
model, defined in Euclidean space and modified by the T-dependent caloron
solution. The background electromagnetic fields are induced to the QCD vacuum,
employing the Schwinger method. We first compute the scalar (chiral) and tensor
condensates as functions of T as well the current-quark mass m, signaling the
correct universal chiral restoration patterns. It turns out that chi_q, given
by the ratio of the two condensates, is a smoothly decreasing function of T,
showing about 20% reduction of its strength at the chiral transition T = T_0,
in comparison to that at T = 0, and decreases almost linearly beyond T_0 for m
> 0. We observe that the present numerical results are in qualitatively good
agreement with other theoretical results, including the lattice simulations.
Finally, we examine the effects of the external magnetic field on the
tensor-polarization VEV, resulting in that it plays the role of the chiral
order parameter.


title:
The isotropic-to-nematic phase transition in hard helices: theory and
  simulation

abstract:
  We investigate the isotropic-to-nematic phase transition in systems of hard
helical particles, using Onsager theory and Monte Carlo computer simulations.
Motivation of this work resides in the ubiquity of the helical shape motif in
many natural and synthetic polymers, as well as in the well known importance
that the details of size and shape have in determining the phase behaviour and
properties of (soft) condensed matter systems. We discuss the differences with
the corresponding spherocylinder phase diagram and find that the helix
parameters affect the phase behaviour and the existence of the nematic phase.
We find that for high helicity Onsager theory significantly departs from
numerical simulations even when a modifed form of the Parsons-Lee rescaling is
included to account for the non-convexity of particles.


title:
Analysis of bibliometric indicators for individual scholars in a large
  data set

abstract:
  Citation numbers and other quantities derived from bibliographic databases
are becoming standard tools for the assessment of productivity and impact of
research activities. Though widely used, still their statistical properties
have not been well established so far. This is especially true in the case of
bibliometric indicators aimed at the evaluation of individual scholars, because
large-scale data sets are typically difficult to be retrieved. Here, we take
advantage of a recently introduced large bibliographic data set, Google Scholar
Citations, which collects the entire publication record of individual scholars.
We analyze the scientific profile of more than 30,000 researchers, and study
the relation between the h-index, the number of publications and the number of
citations of individual scientists. While the number of publications of a
scientist has a rather weak relation with his/her h-index, we find that the
h-index of a scientist is strongly correlated with the number of citations that
she/he has received so that the number of citations can be effectively be used
as a proxy of the h-index. Allowing for the h-index to depend on both the
number of citations and the number of publications, we find only a minor
improvement.


title: Filtrations induced by continuous functions

abstract:
  In Persistent Homology and Topology, filtrations are usually given by
introducing an ordered collection of sets or a continuous function from a
topological space to $\R^n$. A natural question arises, whether these
approaches are equivalent or not. In this paper we study this problem and prove
that, while the answer to the previous question is negative in the general
case, the approach by continuous functions is not restrictive with respect to
the other, provided that some natural stability and completeness assumptions
are made. In particular, we show that every compact and stable 1-dimensional
filtration of a compact metric space is induced by a continuous function.
Moreover, we extend the previous result to the case of multi-dimensional
filtrations, requiring that our filtration is also complete. Three examples
show that we cannot drop the assumptions about stability and completeness.
Consequences of our results on the definition of a distance between filtrations
are finally discussed.


title: Self-trapping threshold in disordered nonlinear photonic lattices

abstract:
  We investigate numerically and experimentally the influence of coupling
disorder on the self-trapping dynamics in nonlinear one-dimensional optical
waveguide arrays. The existence of a lower and upper bound of the effective
average propagation constant allows for a generalized definition of the
threshold power for the onset of soliton localization. When compared to
perfectly ordered systems, this threshold is found to decrease in the presence
of coupling disorder.


title: The CMB asymmetry from inflation

abstract:
  Erickcek, Kamionkowski and Carroll proposed in 2008 that the dipole
modulation of the CMB could be due to a very large scale perturbation of the
field $\phi$ causing the primordial curvature perturbation. We repeat their
calculation using weaker assumptions and the current data. If $\phi$ is the
inflaton of {\em any} single-field inflation with the attractor behaviour, the
asymmetry is almosy certainly too small. If instead $\phi$ is {\em any}
curvaton-type field (ie.\ one with the canonical kinetic term and a negligible
effect during inflation) the asymmetry can agree with observation if $|\fnl|$
in the equilateral configuration is $\simeq 10$ for $k\mone=1\Gpc$ and $\lsim
3$ for $k\mone=1\Mpc$. An $\fnl$ with these properties can apparently be
obtained from the curvaton with an axionic potential. Within any specific
curvaton-type model, the function $\fnl(k_1,k_2,k_3)$ required to generate the
asymmetry would be determined, and could perhaps already be confirmed or ruled
out using existing Planck or WMAP data.


title:
Exponentially convergent method for integral nonlocal problem for the
  first order differential equation with unbounded coefficient in Banach space

abstract:
  Problem for the first order differential equation with an unbounded operator
coefficient in Banach space and integral nonlocal condition is considered. An
exponentially convergent algorithm is proposed and justified for the numerical
solution of this problem in assumption that an operator coefficient $A$ is
strongly positive and some existence and uniqueness conditions are fulfilled.
This algorithm is based on the representations of operator functions by a
Dunford-Cauchy integral along a hyperbola, enveloping the spectrum of $A$, and
on the proper quadratures involving short sums of resolvents. The efficiency of
the proposed algorithms is demonstrated by several numerical examples.


title: RKKY interaction in heavily vacant graphene

abstract:
  Dirac electrons in clean graphene can mediate the interactions between two
localized magnetic moments. The functional form of the RKKY interaction in
pristine graphene is specified by two main features: (i) an atomic scale
oscillatory part determined by a wave vector $\vec Q$ connecting the two
valleys. Furthermore with doping another longer range oscillation appears which
arise from the existence of an extended Fermi surface characterized by a single
momentum scale $k_F$. (ii) $R^{\alpha}$ decay in large distances where the
exponent $\alpha=-3$ is a distinct feature of undoped Dirac sea (with a linear
dispersion relation) in two dimensions. In this work, we investigate the effect
of a few percent vacancies on the above properties. Depending on the doping
level, if the chemical potential lies on the linear part of the density of
states, the exponent $\alpha$ remains close to -3. Otherwise $\alpha$ reduces
towards more negative values which means that the combined effect of vacancies
and the randomness in their positions makes it harder for the carriers of the
medium to mediate the magnetic interaction. Addition of a few percent of
vacancies diminishes the atomic scale oscillations of the RKKY interaction
signaling the destruction of two-valley structure of the parent graphene
material. Surprisingly by allowing the chemical potential to vary, we find that
the longer-range oscillations expected to arise from the existence of a $k_F$
scale in the vacant graphene are absent. This may indicate possible non-Fermi
liquid behavior by "alloying" graphene with vacancies. The complete absence of
oscillations in heavily vacant graphene can be considered an advantage for
applications as a uniform sign of the exchange interaction is desirable for
magnetic ordering.


title: Enhanced pair-correlation functions in the two-dimensional Hubbard model

abstract:
  In this study we have computed the pair correlation functions in the
two-dimensional Hubbard model using a quantum Monte Carlo method. We employ a
new diagonalization algorithm in quantum Monte Carlo method which is free from
the negative sign problem. We show that the d-wave pairing correlation function
is indeed enhanced slightly for the positive on-site Coulomb interaction U when
doping away from the half-filling. When the system size becomes large, the pair
correlation function P_d is increased for U>0 compared to the non-interacting
case, while P_d is suppressed for U>0 when the system size is small. The
enhancement ratio P_d[U]/P_d[U=0] will give a criterion on the existence of
superconductivity. The ratio P_d[U]/P_d[U=0] increases almost linearly \propto
L as the system size L\times L is increased. This increase is a good indication
of an existence of superconducting phase in the two-dimensional Hubbard model.
There is, however, no enhancement of pair correlation functions at
half-filling, which indicates the absence of superconductivity without hole
doping.


title: Free subgroups acting properly discontinuously

abstract:
  Given an action of a group G on a topological space X, we establish a
necessary and sufficient condition for the existence of a free subgroup F of
rank 2 of G acting properly discontinuously on at least one nonempty, open,
F-invariant subspace of X. In the case of a discrete topology (group action on
a set X), the condition simply detects free subgroups of rank 2 acting freely
on some orbit.


title:
Magnetic proximity effect at the 3D topological insulator/magnetic
  insulator interface

abstract:
  The magnetic proximity effect is a fundamental feature of heterostructures
composed of layers of topological insulators and magnetic materials since it
underlies many potential applications in devices with novel quantum
functionality. Within density functional theory we study magnetic proximity
effect at the 3D topological insulator/magnetic insulator (TI/MI) interface in
Bi$_2$Se$_3$/MnSe(111) system as an example. We demonstrate that a gapped
ordinary bound state which spectrum depends on the interface potential arises
in the immediate region of the interface. The gapped topological Dirac state
also arises in the system owing to relocation to deeper atomic layers of
topological insulator. The gap in the Dirac cone is originated from an
overlapping of the topological and ordinary interfacial states. This result
being also corroborated by the analytic model, is a key aspect of the magnetic
proximity effect mechanism in the TI/MI structures.


title:
Photon trajectories, anomalous velocities, and weak measurements: A
  classical interpretation

abstract:
  Recently, Kocsis et al. reported the observation of "average trajectories of
single photons" in a two-slit interference experiment [Science 332, 1170
(2011)]. This was possible by using the quantum weak-measurements method, which
implies averaging over many events, i.e., in fact, a multi-photon limit of
classical linear optics. We give a classical-optics interpretation to this
experiment and other related problems. It appears that weak measurements of the
local momentum of photons made by Kocsis et al. represent measurements of the
Poynting vector in an optical field. We consider both the real and imaginary
parts of the local momentum, and show that their measurements have been
realized in classical optics using small probe particles. We also examine the
appearance of "anomalous" values of the local momentum: either negative
(backflow) or exceeding the wavenumber (superluminal propagation). These
features appear to be closely related to vortices and evanescent waves.
Finally, we revisit a number of older works and find examples of
photon-trajectories and anomalous-momentum measurements in various optical
experiments.


title:
Center Vortices and Chiral Symmetry Breaking in SU(2) Lattice Gauge
  Theory

abstract:
  We investigate the chiral properties of near-zero modes for thick classical
center vortices in SU (2) lattice gauge theory as examples of the phenomena
which may arise in a vortex vacuum. In particular we analyze the creation of
near-zero modes from would-be zero modes of various topological charge
contributions from center vortices. We show that classical colorful spherical
vortex and instanton ensembles have almost identical Dirac spectra and the
low-lying eigenmodes from spherical vortices show all characteristic properties
for chiral symmetry breaking. We further show that also vortex intersections
are able to give rise to a finite density of near-zero modes, leading to chiral
symmetry breaking via the Banks-Casher formula. We discuss the mechanism by
which center vortex fluxes contribute to chiral symmetry breaking.


title: Surface parameters of ferritic iron-rich Fe-Cr alloy

abstract:
  Using first-principles density functional theory in the implementation of the
exact muffin-tin orbitals method and the coherent potential approximation, we
studied the surface energy and the surface stress of the thermodynamically most
stable surface facet (100) of the homogeneous disordered body-centred cubic
iron-chromium system in the concentration interval up to 20 at.% Cr. For the
low-index surface facets of Fe and Cr, the surface energy of Cr is slightly
larger than the one of Fe, while the surface stress of Cr is considerably
smaller than the one of Fe. We find that Cr addition to Fe generally increases
the surface energy of the Fe-Cr alloy, however, an increase of the bulk amount
of Cr also increases the surface stress. As a result of this unexpected trend,
the (100) surface of Fe-Cr becomes more stable against reconstruction with
increasing Cr concentration. We show that the observed trends are of magnetic
origin. In addition to the homogeneous alloy case, we also investigated the
impact of surface segregation on both surface parameters.


title:
Large-scale radio continuum properties of 19 Virgo cluster galaxies The
  influence of tidal interactions, ram pressure stripping, and accreting gas
  envelopes

abstract:
  Deep scaled array VLA 20 and 6cm observations including polarization of 19
Virgo spirals are presented. This sample contains 6 galaxies with a global
minimum of 20cm polarized emission at the receding side of the galactic disk
and quadrupolar type large-scale magnetic fields. In the new sample no
additional case of a ram-pressure stripped spiral galaxy with an asymmetric
ridge of polarized radio continuum emission was found. In the absence of a
close companion, a truncated HI disk, together with a ridge of polarized radio
continuum emission at the outer edge of the HI disk, is a signpost of ram
pressure stripping. 6 out of the 19 observed galaxies display asymmetric 6cm
polarized emission distributions. Three galaxies belong to tidally interacting
pairs, two galaxies host huge accreting HI envelopes, and one galaxy had a
recent minor merger. Tidal interactions and accreting gas envelopes can lead to
compression and shear motions which enhance the polarized radio continuum
emission. In addition, galaxies with low average star formation rate per unit
area have a low average degree of polarization. Shear or compression motions
can enhance the degree of polarization. The average degree of polarization of
tidally interacting galaxies is generally lower than expected for a given
rotation velocity and star formation activity. This low average degree of
polarization is at least partly due to the absence of polarized emission from
the thin disk. Ram pressure stripping can decrease whereas tidal interactions
most frequently decreases the average degree of polarization of Virgo spiral
galaxies. We found that moderate active ram pressure stripping has no influence
on the spectral index, but enhances the global radio continuum emission with
respect to the FIR emission, while an accreting gas envelope can but not
necessarily enhances the radio continuum emission with respect to the FIR
emission.


title:
Three Packets of Minerals of the Periodic Table of Chemical Elements and
  Chemical Compounds

abstract:
  The concepts of alpha- and beta-packets of the periodic table of chemical
elements and chemical compounds are defined. The first of the 47 minerals
alpha-packets is composed. In it all minerals are arranged in increasing Iav
index of proportionality of atomic weights of composing chemical elements, the
same way as chemical elements are located in increasing atomic weights in the
Periodic table. The packet includes 93 known minerals and two compounds - N2O5
and CO2 - being actually minerals. Beta-packet of oxides and hydroxides
minerals includes 88 known minerals and five chemical compounds - N2O5, CO2,
CO, SO3 and SO2. Two minerals of the packet have not been determined yet.
Besides, beta-packet of minerals with sulfur, selenium or arsenic is composed,
with one mineral not defined yet. The results of the calculations can be used
for further development of the Periodic Table of Chemical Elements and Chemical
Compounds and their properties investigation.


title:
Observational Study of Higher Dimensional Magnetic Universe in
  Non-linear Electrodynamics

abstract:
  In this work, we have considered the flat FRW model of the universe in
$(n+2)$-dimensions filled with the dark matter and the magnetic field. We
present the Hubble parameter in terms of the observable parameters
$\Omega_{m0}$ and $H_{0}$ with the redshift $z$ and the other parameters like
$B_{0},\omega, \mu_{0},\delta,n,w_{m}$. The natures of magnetic field $B$,
deceleration parameter $q$ and $Om$ diagnostic have also been analyzed for
accelerating expansion of the universe. From Stern data set (12 points), we
have obtained the bounds of the arbitrary parameters by minimizing the
$\chi^{2}$ test. The best-fit values of the parameters are obtained by 66%, 90%
and 99% confidence levels. Now to find the bounds of the parameters
($B_{0},\omega$) and to draw the statistical confidence contour, we fixed four
parameters $\mu_{0},\delta,n,w_{m}$. Here the parameter $n$ determines the
higher dimensions and we perform comparative study between three cases : 4D
$(n=2)$, 5D $(n=3)$ and 6D $(n=4)$ respectively. Next due to joint analysis
with BAO observation, we have also obtained the bounds of the parameters
($B_{0},\omega$) by fixing other parameters $\mu_{0},\delta,n,w_{m}$ for 4D, 5D
and 6D. The best fit of distance modulus for our theoretical model and the
Supernova Type Ia Union2 sample are drawn for different dimensions.


title:
Prediction of first-order martensitic transitions in strained epitaxial
  films

abstract:
  Coherent epitaxial growth allows to produce crystalline films with strained
structures which are unstable in the bulk. Thereby, the relationship between
the lattice parameters of the overlayer in the interface plane, $(a,b)$, and
its minimum-energy out-of-plane lattice parameter, $c_{\text{min}}(a,b)$, need
not be continuous. This general statement is proven by examples of total energy
calculations. As a consequence, $c_{\text{min}}$, which is determined by the
choice of the substrate, and $c_{\text{min}}$-dependent intrinsic properties of
the overlayer cannot always be tuned in a continuous way as one may aim to do
by means of strained epitaxy. Employing the model of the epitaxial Bain path we
predict that such discontinuities occur in films of the elements V, Nb, Ru, La,
Os, and Ir. The abrupt change of $c_{\text{min}}$ can be exploited to switch
properties specific to the overlayer material. This is demonstrated for the
example of the superconducting critical temperature of a V film which we
predict to jump by 20% at a discontinuity of $c_{\text{min}}$


title:
Heat transport through a quantum Brownian harmonic chain beyond the
  weak-coupling regime: An exact treatment

abstract:
  We consider a linear chain of quantum harmonic oscillators, in which the
number of the individual oscillators is given by an arbitrary number N, and
each oscillator is coupled at an arbitrary strength kappa to its nearest
neighbors ("intra-coupling"), as well as the two end oscillators of the chain
are coupled at an arbitrary strength c_nu to two separate baths at arbitrarily
different temperatures, respectively. We derive an exact closed expression for
the steady-state heat current flowing from a hot bath through the chain to a
cold bath, in the Drude-Ullersma damping model going beyond the Markovian
damping. This allows us to explore the behavior of heat current relative to the
intra-coupling strength as a control parameter, especially in pursuit of the
heat power amplification. Then it turns out that in the weak-coupling regime
(kappa, c_nu << 1), the heat current is small, as expected, and almost
independent of chain length N, hence violating Fourier's law of heat
conduction; this is consistent to the earlier results obtained within the
rotating wave approximation for the intra-coupling as well as in the
Born-Markov approximation for the chain-bath coupling. Beyond the weak-coupling
regime, on the other hand, we typically observe that with increase of the
intra-coupling strength the heat current is gradually amplified, and reaches
its maximum value at some specific coupling strength kappa_R "resonant" to a
given chain-bath coupling strength. Also, the behavior of heat current versus
chain length appears typically in such a way that the magnitude of current
reaches its maximum with N=1 and then gradually decreases with increase of the
chain length, being in fact almost N-independent in the range of N large
enough. As a result, Fourier's law proves violated also in this regime.


title: Dynamics of Antiferromagnets Driven by Spin Current

abstract:
  When a spin-polarized current flows through a ferromagnetic (FM) metal,
angular momentum is transferred to the background magnetization via
spin-transfer torques. In antiferromagnetic (AFM) materials, however, the
corresponding problem is unsolved. We derive microscopically the dynamics of an
AFM system driven by spin current generated by an attached FM polarizer, and
find that the spin current exerts a driving force on the local staggered order
parameter. The mechanism does not rely on the conservation of spin angular
momentum, nor does it depend on the induced FM moments on top the AFM
background. Two examples are studied: (i) A domain wall is accelerated to a
terminal velocity by purely adiabatic effect where the Walker's break-down is
avoided; and (ii) Spin injection modifies the AFM resonance frequency, and spin
current injection triggers spin wave instability of local moments above a
threshold.


title:
Helicity Dependent Directional Surface Plasmon Polariton Excitation
  Using A Metasurface with Interfacial Phase Discontinuity

abstract:
  Surface plasmon polaritons (SPPs) have been widely exploited in various
scientific communities, ranging from physics, chemistry to biology, due to the
strong confinement of light to the metal surface. For many applications it is
important that the free space photon can be coupled to SPPs in a controllable
manner. In this Letter, we apply the concept of interfacial phase discontinuity
for circularly polarizations on a metasurface to the design of a novel type of
polarization dependent SPP unidirectional excitation at normal incidence.
Selective unidirectional excitation of SPPs along opposite directions is
experimentally demonstrated at optical frequencies by simply switching the
helicity of the incident light. This approach, in conjunction with dynamic
polarization modulation techniques, opens gateway towards integrated plasmonic
circuits with electrically reconfigurable functionalities.


title:
String theories on warped AdS backgrounds and integrable deformations of
  spin chains

abstract:
  We study integrable deformations of AdS/CFT by focusing upon three kinds of
warped AdS_3 geometries, 1) space-like warped AdS_3, 2) time-like warped AdS_3
and 3) null warped AdS_3. These geometries are embedded into type IIB
supergravity solutions and are regarded as consistent string backgrounds. By
restricting the classical motion of strings on the warped AdS_3xS^1 subspace,
the Landau-Lifshitz sigma models are derived by taking the fast-moving limit.
The first two warped AdS_3 spaces correspond to anisotropic deformations of the
sl(2) spin chain and the last one to Jordanian deformations. After taking the
continuum limit of the deformed spin chains with coherent states, the resulting
theories agree with the Landau-Lifshitz sigma models obtained from the
string-theory side.


title:
Light amplification and scattering by clusters made of small active
  particles: the local perturbation approach

abstract:
  The light amplification by finite active media is used extensively in modern
optics applications. In this paper the light amplification and scattering by
cluster of small particles is studied analytically and numerically with the
help of the local perturbation method and phenomenological laser theory. It is
shown that light amplification is possible even for one small particle, and
that the amplification is more profound when the light frequency nears the
frequency of the cluster's morphological resonance. Theoretical discussions are
supplemented by numerical results for scattering by clusters which particles
positioned at ordered and at slightly disordered positions.


title:
Non-equilibrium and proximity effects in superconductor-normal metal
  junctions

abstract:
  We study the consequences of non-equilibrium heating and inverse proximity
effect in normal metal - insulator - superconductor - insulator - normal metal
(NISIN) junctions with a simple quasi-one-dimensional model. We especially
focus on observables and parameter regions that are of interest in the design
of SINIS coolers with quasiparticle traps. We present numerical results
calculated by solving the Usadel equation and also present analytical
approximations in two limiting cases: a short junction with a non-negligible
resistance in both ends and a long junction with a transparent contact at one
end.


title:
Minimal singular metrics of a line bundle admitting no
  Zariski-decomposition

abstract:
  We give a concrete expression of a minimal singular metric of a big line
bundle on a compact K\"ahler manifold which is the total space of a toric
bundle over a complex torus. In this class of manifolds, Nakayama constructed
examples which have line bundles admitting no Zariski-decomposition even after
any proper modifications. As an application, we discuss the Zariski-closedness
of non-nef loci and the openness conjecture of Demailly and Koll\'{a}r in this
class.


title:
Testing lepton flavor universality in terms of data of BES III and
  charm-tau factory

abstract:
  The recent measurements on $R_K$ and $R_{\pi}$ imply that there exists a
possible violation of the leptonic flavor universality which is one of the
cornerstones of the standard model. It is suggested that a mixing between
sterile and active neutrinos might induce such a violation. In this work we
consider the scenarios with one or two sterile neutrinos to explicitly realize
the data while the constraints from the available experiments have been taken
into account. Moreover, as indicated in literature, the deviation of the real
PMNS matrix from the symmetric patterns may be due to a $\mu-\tau$ asymmetry,
therefore the measurements on $R_{D(D_s)e\mu} = \Gamma(D(D_s)\rightarrow
e^+\nu_e)/\Gamma(D(D_s)\rightarrow \mu^+\nu_\mu)$ and $R_{D(D_s)\mu\tau} =
\Gamma(D(D_s)\rightarrow \mu^+\nu_\mu)/\Gamma(D(D_s)\rightarrow
\mu^+\tau_\tau)$ (and for some other heavy mesons $B^{\pm}$ and $B_c$ etc.) may
shed more light on physics responsible for the violation of the leptonic flavor
universality. The data of BES III are available to test the universality and
that of the future charm-tau factory will provide more accurate information
towards the aspect, in this work, we will discuss $R_{D(D_s)e\mu}$ and
$R_{D(D_s)\mu\tau}$ in all details and also briefly consider the cases for
$B^{\pm}$ and $B_c$.


title: Gaussian Beam Methods for the Helmholtz Equation

abstract:
  In this work we construct Gaussian beam approximations to solutions of the
high frequency Helmholtz equation with a localized source. Under the assumption
of non-trapping rays we show error estimates between the exact outgoing
solution and Gaussian beams in terms of the wave number $k$, both for single
beams and superposition of beams. The main result is that the relative local
$L^2$ error in the beam approximations decay as {$k^{-N/2}$ independent of
dimension and presence of caustics, for $N$-th order beams.


title: Recent advances in contextuality tests

abstract:
  Our everyday experiences support the hypothesis that physical systems exist
independently of the act of observation. Concordant theories are characterized
by the objective realism assumption whereby the act of measurement simply
reveals preexisting well defined elements of reality. In stark contrast quantum
mechanics portrays a world in which reality loses its objectivity and is in
fact created by observation. Quantum contextuality as first discovered by Bell
[Rev. Mod. Phys. 38, 447 (1966)] and Kochen-Specker [J. Math. Mech. 17, 59
(1967)] captures aspects of this philosophical clash between classical and
quantum descriptions of the world. Here we briefly summarize some of the more
recent advances in the field of quantum contextuality. We approach quantum
contextuality through its close relation to Bell type nonlocal scenarios and
highlight some of the rapidly developing tests and experimental
implementations.


title:
Galactic interaction as the trigger for the young radio galaxy MRC
  B1221-423

abstract:
  Mergers between a massive galaxy and a small gas-rich companion (minor
mergers) have been proposed as a viable mechanism for triggering radio emission
in an active galaxy. Until now the problem has been catching this sequence of
events as they occur. With MRC B1221$-$423 we have an active radio galaxy that
has only recently been triggered, and a companion galaxy that provides the
"smoking gun". Using spectroscopic data taken with the VIMOS Integral Field
Unit detector on the European Southern Observatory's Very Large Telescope, we
have examined the distribution, ionization state and kinematics of ionized gas
in this interacting system. We have also modelled the stellar continuum with
synthesised spectra of stellar populations of different ages. From our study of
the ionized gas, we have derived preliminary models for the geometry of the
interaction, analysed the kinematic behaviour of the ionized gas, and examined
the ionization mechanisms at work throughout the system. Our modelling of the
stellar continuum allowed us to identify and date distinct stellar populations
within the galaxy pair. We find evidence of multiple episodes of widespread
starburst activity, and by dating these populations, we provide tentative
insight into the history of the interaction.