title: High Scale Mixing Unification for Dirac Neutrinos

abstract:
  Starting with high scale mixing unification hypothesis, we investigate the
renormalization group evolution of mixing parameters and masses for Dirac type
neutrinos. Following this hypothesis, the PMNS mixing angles and phase are
taken to be identical to the CKM ones at a unifying high scale. Then, they are
evolved to a low scale using renormalization-group equations. The notable
feature of this hypothesis is that renormalization group evolution with
quasi-degenerate mass pattern can explain largeness of leptonic mixing angles
even for Dirac neutrinos. The renormalization group evolution "naturally"
results in a non-zero and small value of leptonic mixing angle $\theta_{13}$.
One of the important predictions of this work is that the mixing angle
$\theta_{23}$ is non-maximal and lies only in the second octant. We also derive
constraints on the allowed parameter range for the SUSY breaking and
unification scales for which this hypothesis works. The results are novel and
can be tested by present and future experiments.


title: $Q_{6}$ As The Flavour Symmetry in a Non-minimal SUSY $SU(5)$ Model

abstract:
  We present a non-minimal renormalizable SUSY $SU(5)$~model, with extended
Higgs sector and right-handed neutrinos, where the flavour sector exhibits a
$Q_{6}$ flavour symmetry. We analysed the simplest version of this model, in
which R-parity is conserved and the right-handed neutrino masses in the flavour
doublet are considered with and without degeneration. We find the generic form
of the mass matrices both in the quark and lepton sectors. We reproduce,
according to current data, the mixing in the CKM matrix. In the leptonic
sector, in the general case where the right-handed neutrino masses are not
degenerate, we find that the values for the solar, atmospheric, and reactor
mixing angles are in very good agreement with the experimental data, both for a
normal and an inverted hierarchy. In the particular case where the right handed
neutrinos masses are degenerate, the model predicts a strong inverted hierarchy
spectrum and a sum rule among the neutrino masses. In this case the atmospheric
and solar angles are in very good agreement with experimental data, and the
reactor one is different from zero, albeit too small ($\theta^{\ell^{th}}_{13}
\sim 3.38 $). This value constitues a lower bound for $\theta_{13}$ in the
general case. We also find the range of values for the neutrino masses in each
case.


title: The global sections of the chiral de Rham complex on a Kummer surface

abstract:
  The chiral de Rham complex is a sheaf of vertex algebras {\Omega}^ch_M on any
nonsingular algebraic variety or complex manifold M, which contains the
ordinary de Rham complex as the weight zero subspace. We show that when M is a
Kummer surface, the algebra of global sections is isomorphic to the N = 4
superconformal vertex algebra with central charge 6. Previously, CP^n was the
only manifold where a complete description of the global section algebra was
known.


title:
Bernstein type theorem for entire weighted minimal graphs in
  $\mathbb{G}^n\times\mathbb{R}$

abstract:
  Based on a calibration argument, we prove a Bernstein type theorem for entire
minimal graphs over Gauss space $\mathbb{G}^n$ by a simple proof.


title:
The classification of constant weighted curvature curves in the plane
  with a log-linear density

abstract:
  In this paper, we classify the class of constant weighted curvature curves in
the plane with a log-linear density, or in other words, classify all traveling
curved fronts with a constant forcing term in $\Bbb R^2.$ The classification
gives some interesting phenomena and consequences including: the family of
curves converge to a round point when the weighted curvature of curves (or
equivalently the forcing term of traveling curved fronts) goes to infinity, a
simple proof for a main result in [13] as well as some well-known facts
concerning to the isoperimetric problem in the plane with density $e^y.$


title: A Realization of Effective SUSY with Strong Unification

abstract:
  A natural model of realizing the effective supersymmetry is presented. Two
sets of the Standard Model-like gauge group $G_1\times G_2$ are introduced,
where $G_i=SU(3)_i\times SU(2)_i\times U(1)_i$, which break diagonally to the
Standard Model gauge group at the energy scale $M \sim 10^7$ GeV. Gauge
couplings in $G_1$ are assumed much larger than that in $G_2$. Gauge mediated
supersymmetry breaking is adopted. The first two generations (third one) are
charged only under $G_1$ ($G_2$). The effective supersymmetry spectrum is
obtained. How to reproduce realistic Yukawa couplings is studied. Fine-tuning
for an 126 GeV Higgs is much reduced by the large $A$ term due to direct
Higgs-messenger interaction. Finally, $G_2$ is found to be a non-trivial
realization of the strong unification scenario in which case we can predict
$\alpha_s(M_Z)$ without real unification


title: Nonintersecting Brownian motions on the unit circle

abstract:
  We consider an ensemble of $n$ nonintersecting Brownian particles on the unit
circle with diffusion parameter $n^{-1/2}$, which are conditioned to begin at
the same point and to return to that point after time $T$, but otherwise not to
intersect. There is a critical value of $T$ which separates the subcritical
case, in which it is vanishingly unlikely that the particles wrap around the
circle, and the supercritical case, in which particles may wrap around the
circle. In this paper, we show that in the subcritical and critical cases the
probability that the total winding number is zero is almost surely 1 as
$n\to\infty$, and in the supercritical case that the distribution of the total
winding number converges to the discrete normal distribution. We also give a
streamlined approach to identifying the Pearcey and tacnode processes in
scaling limits. The formula of the tacnode correlation kernel is new and
involves a solution to a Lax system for the Painlev\'{e} II equation of size 2
$\times$ 2. The proofs are based on the determinantal structure of the
ensemble, asymptotic results for the related system of discrete Gaussian
orthogonal polynomials, and a formulation of the correlation kernel in terms of
a double contour integral.


title: Division Algebra Representations of SO(4,2)

abstract:
  Representations of $\text{SO}(4,2)$ are constructed using $4\times4$ and
$2\times2$ matrices with elements in $\mathbb{H}'\otimes\mathbb{C}$, and the
known isomorphism between the conformal group and $\text{SO}(4,2)$ is written
explicitly in terms of the $4\times4$ representation.


title:
Quantum States of an Electron Interacting with Various Dielectric Plate
  Geometries

abstract:
  The tunability of binding energies is explored by modulating a finite
dielectric slab width in a planar, three dielectric system. After verifying the
equivalence of the field method and method of images, three different
configurations are explored for possible control of electronic binding energy:
A vacuum gap between a Schottky diode, noble gas layers on a metal wall, and an
electron confined between two metal plates. In each, varying the width of the
finite, middle dielectric was shown to provide control over the binding energy
and Bohr radius of the electron. In the case of an electron confined between
two plates, it was found that the bound states smoothly connect to the box
states as the gap separation was varied. Lastly, forces on the two parallel
plates were examined for a possible source of significant repulsion. All
numerical calculations were done in MATLAB.


title: Electrodynamics acceleration of electrical dipoles

abstract:
  This article considers the acceleration of electric dipoles consisting of
thin metal plates and dielectric (barium titanate). The dipoles are of a
cylindrical shape with a diameter of the cylinder two centimeters and length
one centimeter. Capacity of the parallel-plate capacitor is three hundred
picofarads and it is charged up to the voltage of two hundred eighty kilovolts.
Pre-acceleration of the electric dipoles till velocity one kilometer per second
is reached by the gas-dynamic method. The finite acceleration is produced in a
spiral waveguide, where the pulse is travelling with voltage amplitude seven
hundreds kilovolts and power one hundred twenty-five megawatts. This pulse
travels via the spiral waveguide and accelerates the injected electric dipoles
in the longitudinal direction till the finite velocity eight and a half
kilometers per second over length seven hundred and seventy meters.


title: Topological modular forms with level structure

abstract:
  The cohomology theory known as Tmf, for "topological modular forms," is a
universal object mapping out to elliptic cohomology theories, and its
coefficient ring is closely connected to the classical ring of modular forms.
We extend this to a functorial family of objects corresponding to elliptic
curves with level structure and modular forms on them. Along the way, we
produce a natural way to restrict to the cusps, providing multiplicative maps
from Tmf with level structure to forms of K-theory. In particular, this allows
us to construct a connective spectrum tmf_0(3) consistent with properties
suggested by Mahowald and Rezk.
  This is accomplished using the machinery of logarithmic structures. We
construct a sheaf of locally even-periodic elliptic cohomology theories,
equipped with highly structured multiplication, on the log-\'etale site of the
moduli of elliptic curves. Evaluating this sheaf on modular curves produces Tmf
with level structure.


title: On the multi-frequency inverse source problem in heterogeneous media

abstract:
  The inverse source problem where an unknown source is to be identified from
the knowledge of its radiated wave is studied. The focus is placed on the
effect that multi-frequency data has on establishing uniqueness. In particular,
it is shown that data obtained from finitely many frequencies is not
sufficient. On the other hand, if the frequency varies within a set with an
accumulation point, then the source is determined uniquely, even in the
presence of highly heterogeneous media. In addition, an algorithm for the
reconstruction of the source using multi-frequency data is proposed. The
algorithm, based on a subspace projection method, approximates the minimum-norm
solution given the available multi-frequency measurements. A few numerical
examples are presented.


title: One-dimensional heat equation with discontinuous conductance

abstract:
  We study a second-order parabolic equation with divergence form elliptic
operator, having piecewise constant diffusion coefficients with two points of
discontinuity. Such partial differential equations appear in the modelization
of diffusion phenomena in medium consisting of three kind of materials. Using
probabilistic methods, we present an explicit expression of the fundamental
solution under certain conditions. We also derive small-time asymptotic
expansion of the PDE's solutions in the general case. The obtained results are
directly usable in applications.


title:
Dielectron Mass Spectra from Au+Au Collisions at $\sqrt{s_{\rm NN}}$ =
  200 GeV

abstract:
  We report the STAR measurements of dielectron ($e^+e^-$) production at
midrapidity ($|y_{ee}|<$1) in Au+Au collisions at $\sqrt{s_{\rm NN}}$ =
200\,GeV. The measurements are evaluated in different invariant mass regions
with a focus on 0.30-0.76 ($\rho$-like), 0.76-0.80 ($\omega$-like), and
0.98-1.05 ($\phi$-like) GeV/$c^{2}$. The spectrum in the $\omega$-like and
$\phi$-like regions can be well described by the hadronic cocktail simulation.
In the $\rho$-like region, however, the vacuum $\rho$ spectral function cannot
describe the shape of the dielectron excess. In this range, an enhancement of
1.77$\pm$0.11(stat.)$\pm$0.24(sys.)$\pm$0.33(cocktail) is determined with
respect to the hadronic cocktail simulation that excludes the $\rho$ meson. The
excess yield in the $\rho$-like region increases with the number of collision
participants faster than the $\omega$ and $\phi$ yields. Theoretical models
with broadened $\rho$ contributions through interactions with constituents in
the hot QCD medium provide a consistent description of the dilepton mass
spectra for the measurement presented here and the earlier data at the Super
Proton Synchrotron energies.


title:
Global regularity for the critical 2-D dissipative quasi-geostrophic
  equation with force

abstract:
  This is a remark that by using an adaptation of the technique invented by A.
Kiselev, F. Nazarov, and A. Voldberg, with a modified scaling argument, we can
prove global regularity of the critical 2-D dissipative quasi-geostrophic
equation with smooth periodic force, under the assumption that the initial data
is smooth and periodic, and the force is $\alpha$-H\"older continuous in space,
$\alpha > 0$.


title: Atomic collapse in graphene and cyclic RG flow

abstract:
  In this Letter we consider the problem of screening of external charge in
graphene from the cyclic RG flow viewpoint. The analogy with conformal Calogero
model is used to suggest the interpretation of the tower of resonant states as
tower of Efimov states.


title: Generalized Factorization in Commutative Rings with Zero-Divisors

abstract:
  Much work has been done on generalized factorization techniques in integral
domains, namely $\tau$-factorization. There has also been substantial progress
made in investigating factorization in commutative rings with zero-divisors.
This paper seeks to synthesize work done in these two areas and extend the
notion of $\tau$-factorization to commutative rings that need not be domains.
In addition, we look into particular types of $\tau$ relations, which are
interesting when there are zero-divisors present. We then proceed to classify
commutative rings that satisfy the finite factorization properties given in
this paper.


title: Data driven sampling of oscillating signals

abstract:
  The reduction of the number of samples is a key issue in signal processing
for mobile applications. We investigate the link between the smoothness
properties of a signal and the number of samples that can be obtained through a
level crossing sampling procedure. The algorithm is analyzed and an upper bound
of the number of samples is obtained in the worst case. The theoretical results
are illustrated with applications to fractional Brownian motions and the
Weierstrass function.


title: Adaptive pointwise estimation of conditional density function

abstract:
  In this paper we consider the problem of estimating $f$, the conditional
density of $Y$ given $X$, by using an independent sample distributed as $(X,Y)$
in the multivariate setting. We consider the estimation of $f(x,.)$ where $x$
is a fixed point. We define two different procedures of estimation, the first
one using kernel rules, the second one inspired from projection methods. Both
adapted estimators are tuned by using the Goldenshluger and Lepski methodology.
After deriving lower bounds, we show that these procedures satisfy oracle
inequalities and are optimal from the minimax point of view on anisotropic
H{\"o}lder balls. Furthermore, our results allow us to measure precisely the
influence of $\mathrm{f}\_X(x)$ on rates of convergence, where $\mathrm{f}\_X$
is the density of $X$. Finally, some simulations illustrate the good behavior
of our tuned estimates in practice.


title: Generalized U-factorization in Commutative Rings with Zero-Divisors

abstract:
  Recently substantial progress has been made on generalized factorization
techniques in integral domains, in particular $\tau$-factorization. There has
also been advances made in investigating factorization in commutative rings
with zero-divisors. One approach which has been found to be very successful is
that of U-factorization introduced by C.R. Fletcher. We seek to synthesize work
done in these two areas by generalizing $\tau$-factorization to rings with
zero-divisors by using the notion of U-factorization.


title: Complete Ricci flat Torus fibrations over ALE spaces

abstract:
  We investigate complete noncompact Ricci-flat manifolds which are not of
maximal volume growth. We show that the manifolds with a curvature decay
condition and a holonomy decay condition are asymptotic to torus fibrations
over ALE spaces. In particular, we classify complete noncompact 4-dimensional
hyperk\"aler manifolds by the volume growth. As an application, we give the
uniqueness of tangent cones of collapsing manifolds with some conditions.


title: On Distance Antimagic Graphs

abstract:
  For an arbitrary set of distances $D\subseteq \{0,1, \ldots, diam(G)\}$, a
$D$-weight of a vertex $x$ in a graph $G$ under a vertex labeling
$f:V\rightarrow \{1,2, \ldots , v\}$ is defined as $w_D(x)=\sum_{y\in N_D(x)}
f(y)$, where $N_D(x) = \{y \in V| d(x,y) \in D\}$. A graph $G$ is said to be
$D$-distance magic if all vertices has the same $D$-vertex-weight, it is said
to be $D$-distance antimagic if all vertices have distinct $D$-vertex-weights,
and it is called $(a,d)-D$-distance antimagic if the $D$-vertex-weights
constitute an arithmetic progression with difference $d$ and starting value
$a$.
  In this paper we study some necessary conditions for the existence of
$D$-distance antimagic graphs. We conjecture that such conditions are also
sufficient. Additionally, we study $\{1\}$-distance antimagic labelings for
some cycle-related connected graphs: cycles, suns, prisms, complete graphs,
wheels, fans, and friendship graphs.


title: Generalized Irreducible Divisor Graphs

abstract:
  In 1988, I. Beck introduced the notion of a zero-divisor graph of a
commutative rings with $1$. There have been several generalizations in recent
years. In particular, in 2007 J. Coykendall and J. Maney developed the
irreducible divisor graph. Much work has been done on generalized
factorization, especially $\tau$-factorization. The goal of this paper is to
synthesize the notions of $\tau$-factorization and irreducible divisor graphs
in domains. We will define a $\tau$-irreducible divisor graph for non-zero
non-unit elements of a domain. We show that by studying $\tau$-irreducible
divisor graphs, we find equivalent characterizations of several finite
$\tau$-factorization properties.


title: On quasihomomorphisms with noncommutative targets

abstract:
  We describe structure of quasihomomorphisms from arbitrary groups to discrete
groups. We show that all quasihomomorphisms are 'constructible', i.e., are
obtained via certain natural operations from homomorphisms to some groups and
quasihomomorphisms to abelian groups. We illustrate this theorem by describing
quasihomomorphisms to certain classes of groups. For instance, every unbounded
quasihomomorphism to a torsion-free hyperbolic group H is either a homomorphism
to a subgroup of H or is a quasihomomorphism to an infinite cyclic subgroup of
H.


title: An overview of $XYZ$ new particles

abstract:
  In the past decade, more and more charmoniumlike and bottomoniumlike states
have been reported in experiments, which have led us to extensive discussions
on the underlying structure of these states. In this review paper, we briefly
summarize the experimental and theoretical status of these observed states.


title: Fredholm multiplication conditional type operators on L^p-spaces

abstract:
  In this paper, first we investigate closed range multiplication conditional
type operators between two Lp-spaces. Then we characterize Fredholm ones when
the underlying measure space is non-atomic. Finally we give some examples.


title:
Six-dimensional origin of gravity mediated brane to brane supersymmetry
  breaking

abstract:
  Four dimensional supergravities may be the right framework to describe
particle physics at low energies. Its connection to the underlying string
theory can be implemented through higher dimensional supergravities which bear
special characteristics. Their reduction to four dimensions breaks
supersymmetry whose magnitude depends both on the compactifying manifold and
the mechanism that generates the breaking. In particular compactifications,
notably on a $S_1/Z_2$ orbifold, the breaking of supersymmetry occuring on a
hidden brane, residing at one end of $S_1/Z_2$, is communicated to the visible
brane which lies at the other end, via gravitational interactions propagating
in the bulk. This scenario has been exemplified in the framework of the $N=2$,
$D=5$ supergravity. In this note, motivated by the recent developments in the
field, related to the six-dimensional description of the supergravity theory,
we study the $N=2$, $D=5$ supergravity theory as originating from a $D=6$
supergravity which, in addition to the gravity, includes a number of tensor
multiplets. This reduces to $N=1$, $D=4$ supergravity in a two step manner,
first by Kaluza-Klein reduction followed by a $S_1/Z_2$ orbifold
compactification. The resulting theory has striking similarities with the one
that follows from the single standalone $N=2$, $D=5$ supergravity, with no
reference to the underlying higher dimensional $D=6$ supergravity, and a
structure that makes the supersymmetry breaking mechanisms studied in the past
easily incorporated in higher dimensional schemes.


title: Impact of spin-orbit coupling on the magnetism of Sr3MIrO6 (M = Ni, Co)

abstract:
  Using density functional calculations, we demonstrate that the spin-orbit
coupling (SOC) of the Ir4+ ion plays an essential role in determining the
antiferromagnetism of the hexagonal spin-chain system Sr3MIrO6 (M = Ni, Co) by
tuning the crystal-field level sequence and altering the Ir-M inter-orbital
interactions. The SOC splits the e'_{g} doublet of the octahedral Ir4+ ion
(t_{2g}^5) in a trigonal crystal field, and the single t_{2g} hole resides on
the e'_{g} upper branch and gives rise to the antiferromagnetic superexchange.
In absence of the SOC, however, the single t_{2g} hole would occupy the a_{1g}
singlet instead, which would mediate an unreal ferromagnetic exchange due to a
direct a_{1g} hopping along the Ir-M chain. We also find that the Ni2+ and Co2+
ions are both in a high-spin state and moreover the Co2+ ion carries a huge
orbital moment. This work well accounts for the recent experiments and
magnifies again the significance of the SOC in iridates.


title: Model reduction of networked passive systems through clustering

abstract:
  In this paper, a model reduction procedure for a network of interconnected
identical passive subsystems is presented. Here, rather than performing model
reduction on the subsystems, adjacent subsystems are clustered, leading to a
reduced-order networked system that allows for a convenient physical
interpretation. The identification of the subsystems to be clustered is
performed through controllability and observability analysis of an associated
edge system and it is shown that the property of synchronization (i.e., the
convergence of trajectories of the subsystems to each other) is preserved
during reduction. The results are illustrated by means of an example.


title:
The mixed two qutrit system: local unitary invariants, entanglement
  monotones, and the SLOCC group SL(3,C)

abstract:
  We consider local unitary invariants and entanglement monotones for the mixed
two qutrit system. Character methods for the local SU(3)xSU(3) transformation
group are used to establish the count of algebraically independent polynomial
invariants up to degree 5 in the components of the density operator. These are
identified up to quartic degree in the standard basis of Gell-Mann matrices,
with the help of the calculus of f and d coefficients. Next, investigating
local measurement operations, we study a SLOCC qutrit group, which plays the
role of a `relativistic' transformation group analogous to that of the Lorentz
group SL(2,C)_R ~ SO(3,1) for the qubit case. This is the group SL(3,C)_R,
presented as a group of real 9x9 matrices acting linearly on the 9-dimensional
space of projective coordinates for the qutrit density matrix. The counterpart,
for qutrits, of the invariant 4x4 Minkowski metric of the qubit case, proves to
be a certain 9x9x9 totally symmetric three-fold tensor generalizing the
Gell-Mann d coefficient. Using this structure, we provide a count of the
corresponding LSL polynomial invariants using group character methods. Finally,
we give an explicit construction of the lowest degree quantity (the cubic
invariant) and its expansion in terms of SU(3)xSU(3) invariants, and we
indicate how to construct higher degree analogues. These quantities are proven
to yield entanglement monotones. This work generalizes and partly extends the
paper of King, Welsh and Jarvis (Journal of Physics A, 40(33):10083, 2007) on
the mixed two qubit system, which is reviewed in an appendix.


title:
Stopping Rules for Bag-of-Words Image Search and Its Application in
  Appearance-Based Localization

abstract:
  We propose a technique to improve the search efficiency of the bag-of-words
(BoW) method for image retrieval. We introduce a notion of difficulty for the
image matching problems and propose methods that reduce the amount of
computations required for the feature vector-quantization task in BoW by
exploiting the fact that easier queries need less computational resources.
Measuring the difficulty of a query and stopping the search accordingly is
formulated as a stopping problem. We introduce stopping rules that terminate
the image search depending on the difficulty of each query, thereby
significantly reducing the computational cost. Our experimental results show
the effectiveness of our approach when it is applied to appearance-based
localization problem.


title: On weighted $L^2$ estimates for solutions of the wave equation

abstract:
  In this paper we consider weighted $L^2$ integrability for solutions of the
wave equation. For this, we obtain some weighed $L^2$ estimates for the
solutions with weights in Morrey-Campanato classes. Our method is based on a
combination of bilinear interpolation and localization argument which makes use
of Littlewood-Paley theorem and a property of Hardy-Littlewood maximal
functions. We also apply the estimates to the problem of well-posedness for
wave equations with potentials.


title: Non-Abelian photon

abstract:
  In this paper, we have proposed $SU(2)$ non-Abelian electromagnetism gauge
theory. In the theory, photon has self-interaction and interaction, which can
explain photon entanglement phenomenon in quantum information. Otherwise, we
find there are three kinds photons $\gamma^{+}$, $\gamma^{-}$ and $\gamma^{0}$,
and they have electric charge $+e_{\gamma}$, $-e_{\gamma}$ and $0$,
respectively, which are accordance with some experiment results.


title: Measuring the X-ray luminosities of SDSS DR7 clusters from RASS

abstract:
  We use ROSAT All Sky Survey (RASS) broadband X-ray images and the optical
clusters identified from SDSS DR7 to estimate the X-ray luminosities around
$\sim 65,000$ candidate clusters with masses $\ga 10^{13}\msunh$ based on an
Optical to X-ray (OTX) code we develop. We obtain a catalogue with X-ray
luminosity for each cluster. This catalog contains 817 clusters (473 at
redshift $z\le 0.12$) with $S/N> 3$ in X-ray detection. We find about $65\%$ of
these X-ray clusters have their most massive member located near the X-ray flux
peak; for the rest $35\%$, the most massive galaxy is separated from the X-ray
peak, with the separation following a distribution expected from a NFW profile.
We investigate a number of correlations between the optical and X-ray
properties of these X-ray clusters, and find that: the cluster X-ray luminosity
is correlated with the stellar mass (luminosity) of the clusters, as well as
with the stellar mass (luminosity) of the central galaxy and the mass of the
halo, but the scatter in these correlations is large. Comparing the properties
of X-ray clusters of similar halo masses but having different X-ray
luminosities, we find that massive halos with masses $\ga 10^{14}\msunh$
contain a larger fraction of red satellite galaxies when they are brighter in
X-ray. ... A cluster catalog containing the optical properties of member
galaxies and the X-ray luminosity is available at {\it
http://gax.shao.ac.cn/data/Group.html}.


title: Centralizers of $C^1$-contractions of the half line

abstract:
  A subgroup $G\subset Diff^1_+([0,1])$ is $C^1$-close to the identity if there
is a sequence $h_n\in Diff^1_+([0,1])$ such that the conjugates $h_n g
h_n^{-1}$ tend to the identity for the $C^1$-topology, for every $g\in G$. This
is equivalent to the fact that $G$ can be embedded in the $C^1$-centralizer of
a $C^1$-contraction of $[0,+\infty)$ (see [Fa] and Theorem 1.1).
  We first describe the topological dynamics of groups $C^1$-close to the
identity. Then, we show that the class of groups $C^1$-close to the identity is
invariant under some natural dynamical and algebraic extensions. As a
consequence, we can describe a large class of groups $G\subset Diff^1_+([0,1])$
whose topological dynamics implies that they are $C^1$-close to the identity.
  This allows us to show that the free group ${\mathbb F}_2$ admits faithfull
actions which are $C^1$-close to the identity. In particular, the
$C^1$-centralizer of a $C^1$-contraction may contain free groups.


title:
Perihelion precession and deflection of light in the general spherically
  symmetric spacetime

abstract:
  In this paper, the perihelion precession and deflection of light have been
investigated in the 4-dimensional general spherically symmetric spacetime, and
the main equation is obtained. As the application of this main equation, the
Reissner-Nordstorm-AdS solution and Clifton-Barrow solution in $f(R)$ gravity
have been taken for the examples. We find that both the electric charge and
$f(R)$ gravity can affect the perihelion precession and deflection of light,
while the cosmological constant can only effect the perihelion precession.
Moreover, we clarify a subtlety in the deflection of light in the solar system
that the possible sun's electric charge is usually used to interpret the gap
between the experiment data and theoretical result. However, after also
considering the effect from the sun's same electric charge on the perihelion
precession of Mercury, we can find that it is not the truth.


title:
Thermalization and canonical typicality in translation-invariant quantum
  lattice systems

abstract:
  It has previously been suggested that small subsystems of closed quantum
systems thermalize under some assumptions; however, this has been rigorously
shown so far only for systems with very weak interaction between subsystems. In
this work, we give rigorous analytic results on thermalization for
translation-invariant quantum lattice systems with finite-range interaction of
arbitrary strength, in all cases where there is a unique equilibrium state at
the corresponding temperature. We clarify the physical picture by showing that
subsystems relax towards the reduction of the global Gibbs state, not the local
Gibbs state, if the initial state has close to maximal population entropy and
certain non-degeneracy conditions on the spectrum are satisfied. Moreover, we
show that almost all pure states with support on a small energy window are
locally thermal in the sense of canonical typicality. We derive our results
from a statement on equivalence of ensembles generalizing earlier results by
Lima, and give numerical and analytic finite-size bounds, relating the Ising
model to the finite de Finetti theorem. Furthermore, we prove that global
energy eigenstates are locally close to diagonal in the local energy
eigenbasis, which constitutes a part of the eigenstate thermalization
hypothesis that is valid regardless of the integrability of the model.

categories: quant-ph cond-mat.stat-mech math-ph math.MP


title:
Non-yrast spectra of odd-A nuclei in a model of coherent
  quadrupole-octupole motion

abstract:
  The model of coherent quadrupole and octupole motion (CQOM) is applied to
describe non-yrast split parity-doublet spectra in odd-mass nuclei. The yrast
levels are described as low-energy rotation-vibration modes coupled to the
ground single-particle (s.p.) state, while the non-yrast parity-doublet
structures are obtained as higher-energy rotation-vibration modes coupled to
excited s.p. states. It is shown that the extended model scheme describes both
the yrast and non-yrast quasi parity-doublet spectra and the related B(E1) and
B(E2) transition rates in different regions of heavy odd-A nuclei. The
involvement of the reflection-asymmetric deformed shell model to describe the
single-particle motion and the Coriolis interaction on a deeper level is
discussed.


title:
Proceedings of Answer Set Programming and Other Computing Paradigms
  (ASPOCP 2013), 6th International Workshop, August 25, 2013, Istanbul, Turkey

abstract:
  This volume contains the papers presented at the sixth workshop on Answer Set
Programming and Other Computing Paradigms (ASPOCP 2013) held on August 25th,
2013 in Istanbul, co-located with the 29th International Conference on Logic
Programming (ICLP 2013). It thus continues a series of previous events
co-located with ICLP, aiming at facilitating the discussion about crossing the
boundaries of current ASP techniques in theory, solving, and applications, in
combination with or inspired by other computing paradigms.


title: Shedding new light on the mystery of wetting on soft solids

abstract:
  One of the most questionable issues in wetting is the vertical force balance
that is excluded in Young's law. On soft deformable solids, such as biotic
materials and synthetic polymers, the vertical force of liquid leads to a
microscopic protrusion of the contact line, i.e. a "wetting ridge". The wetting
principle that determines the geometry of the ridge-tip is at the heart of the
issues over the past half century. Here, we reveal a universal wetting
principle by directly visualizing ridge-tips with high spatio-temporal
resolution using x-ray microscopy. We find that the tip-geometry is asymmetric
and bent, and invariant during ridge growth or by surface softness. This
singular geometry is explained by linking the macroscopic and microscopic
contact angles to Young's and Neumann's laws, respectively. Our dual-scale
model would be applicable to a general framework in wetting and give new clues
to various issues in cell-substrate interaction and elasto-capillary problems.


title: Effective model approach to meson screening masses at finite temperature

abstract:
  Temperature dependence of pion and sigma-meson screening masses is evaluated
by the Polyakov-loop extended Nambu--Jona-Lasinio (PNJL) model with the
entanglement vertex. We propose a practical way of calculating meson screening
masses in the NJL-type effective models. The method based on the Pauli-Villars
regularization solves the well-known difficulty that the evaluaton of screening
masses is not easy in the NJL-type effective models.The PNJL model with the
entanglement vertex and the Pauli-Villars regularization well reproduces
lattice QCD results on temperature dependence of the chiral condensate and the
Polyakov loop. The method is applied to analyze temperature dependence of pion
screening mass calculated with state-of-the-art lattice simulations with
success in reproducing the lattice QCD results.


title: $\mathcal C$-graph automatic groups

abstract:
  We generalize the notion of a graph automatic group introduced by
Kharlampovich, Khoussainov and Miasnikov (arXiv:1107.3645) by replacing the
regular languages in their definition with more powerful language classes. For
a fixed language class $\mathcal C$, we call the resulting groups $\mathcal
C$-graph automatic. We prove that the class of $\mathcal C$-graph automatic
groups is closed under change of generating set, direct and free product for
certain classes $\mathcal C$. We show that for quasi-realtime counter-graph
automatic groups where normal forms have length that is linear in the geodesic
length, there is an algorithm to compute normal forms (and therefore solve the
word problem) in polynomial time. The class of quasi-realtime counter-graph
automatic groups includes all Baumslag-Solitar groups, and the free group of
countably infinite rank. Context-sensitive-graph automatic groups are shown to
be a very large class, which encompasses, for example, groups with unsolvable
conjugacy problem, the Grigorchuk group, and Thompson's groups $F,T$ and $V$.


title: Periodic points and transitivity on dendrites

abstract:
  We study relations between transitivity, mixing and periodic points on
dendrites. We prove that when there is a point with dense orbit which is not an
endpoint, then periodic points are dense and there is a terminal periodic
decomposition (we provide an example of a dynamical system on a dendrite with
dense endpoints satisfying this assumption). We also show that it may happen
that all periodic points except one (and points with dense orbit) are contained
in the (dense) set of endpoints. It may also happen that dynamical system is
transitive but there is a unique periodic point, which in fact is the unique
fixed point. We also prove that on almost meshed-continua (a class of continua
containing topological graphs and dendrites with closed or countable set of
endpoints), periodic points are dense if and only if they are dense for the map
induced on the hyperspace of all nonempty compact subsets.


title:
Multi-Layer Hydrostatic Equilibrium of Planets and Synchronous Moons:
  Theory and Application to Ceres and to Solar System Moons

abstract:
  The hydrostatic equilibrium of multi-layer bodies lacks a satisfactory
theoretical treatment despite its wide range of applicability. Here we show
that by using the exact analytical potential of homogeneous ellipsoids we can
obtain recursive analytical solutions and an exact numerical method for the
hydrostatic equilibrium shape problem of multi-layer planets and synchronous
moons. The recursive solutions rely on the series expansion of the potential in
terms of the polar and equatorial shape eccentricities, while the numerical
method uses the exact potential expression. These solutions can be used to
infer the interior structure of planets and synchronous moons from the observed
shape, rotation, and gravity. When applied to dwarf planet Ceres, we show that
it is most likely a differentiated body with an icy crust of equatorial
thickness 30-90 km and a rocky core of density 2.4-3.1 g/cm$^3$. For
synchronous moons, we show that the $J_2/C_{22} \simeq 10/3$ and the
$(b-c)/(a-c) \simeq 1/4$ ratios have significant corrections of order
$\Omega^2/(\pi G \rho)$, with important implications on how their gravitational
coefficients are determined from flyby radio science data and on how we assess
their hydrostatic equilibrium state.


title: Random Fields, Topology, and The Imry-Ma Argument

abstract:
  We consider $n$-component fixed-length order parameter interacting with a
weak random field in $d=1,2,3$ dimensions. Relaxation from the initially
ordered state and spin-spin correlation functions have been studied on lattices
containing hundreds of millions sites. At $n-1<d$ presence of topological
structures leads to metastability, with the final state depending on the
initial condition. At $n-1>d$, when topological objects are absent, the final,
lowest-energy, state is independent of the initial condition. It is
characterized by the exponential decay of correlations that agrees
quantitatively with the theory based upon the Imry-Ma argument. In the
borderline case of $n-1=d$, when topological structures are non-singular, the
system possesses a weak metastability with the Imry-Ma state likely to be the
global energy minimum.


title: Theory of cylindrical dense packings of disks

abstract:
  We have previously explored cylindrical packings of disks and their relation
to sphere packings. Here we extend the analytical treatment of disk packings,
analysing the rules for phyllotactic indices of related structures and the
variation of the density for line-slip structures, close to the symmetric ones.
We show that rhombic structures, which are of a lower density, are always
unstable i.e. can be increased in density by small perturbations


title:
Simultaneous Perturbation Methods for Adaptive Labor Staffing in Service
  Systems

abstract:
  Service systems are labor intensive due to the large variation in the tasks
required to address service requests from multiple customers. Aligning the
staffing levels to the forecasted workloads adaptively in such systems is
nontrivial because of a large number of parameters and operational variations
leading to a huge search space. A challenging problem here is to optimize the
staffing while maintaining the system in steady-state and compliant to
aggregate service level agreement (SLA) constraints. Further, because these
parameters change on a weekly basis, the optimization should not take longer
than a few hours. We formulate this problem as a constrained Markov cost
process parameterized by the (discrete) staffing levels. We propose novel
simultaneous perturbation stochastic approximation (SPSA) based SASOC (Staff
Allocation using Stochastic Optimization with Constraints) algorithms for
solving the above problem. The algorithms include both first order as well as
second order methods and incorporate SPSA based gradient estimates in the
primal, with dual ascent for the Lagrange multipliers. Both the algorithms that
we propose are online, incremental and easy to implement. Further, they involve
a certain generalized smooth projection operator, which is essential to project
the continuous-valued worker parameter tuned by SASOC algorithms onto the
discrete set. We validated our algorithms on five real-life service systems and
compared them with a state-of-the-art optimization tool-kit OptQuest. Being 25
times faster than OptQuest, our algorithms are particularly suitable for
adaptive labor staffing. Also, we observe that our algorithms guarantee
convergence and find better solutions than OptQuest in many cases.


title: Habitability around F-type Stars

abstract:
  We explore the general astrobiological significance of F-type main-sequence
stars with masses between 1.2 and 1.5 Msun. Special consideration is given to
stellar evolutionary aspects due to nuclear main-sequence evolution. DNA is
taken as a proxy for carbon-based macromolecules following the paradigm that
extraterrestrial biology may be most likely based on hydrocarbons.
Consequently, the DNA action spectrum is utilized to represent the impact of
the stellar UV radiation. Planetary atmospheric attenuation is taken into
account based on parameterized attenuation functions. We found that the damage
inflicted on DNA for planets at Earth-equivalent positions is between a factor
of 2.5 and 7.1 higher than for solar-like stars, and there are intricate
relations for the time-dependence of damage during stellar main-sequence
evolution. If attenuation is considered, smaller factors of damage are obtained
in alignment to the attenuation parameters. This work is motivated by earlier
studies indicating that the UV environment of solar-type stars is one of the
most decisive factors in determining the suitability of exosolar planets and
exomoons for biological evolution and sustainability.


title: A network analysis of Sibiu County, Romania

abstract:
  Network science methods have proved to be able to provide useful insights
from both a theoretical and a practical point of view in that they can better
inform governance policies in complex dynamic environments. The tourism
research community has provided an increasing number of works that analyse
destinations from a network science perspective. However, most of the studies
refer to relatively small samples of actors and linkages. With this note we
provide a full network study, although at a preliminary stage, that reports a
complete analysis of a Romanian destination (Sibiu). Our intention is to
increase the set of similar studies with the aim of supporting the
investigations in structural and dynamical characteristics of tourism
destinations.


title: The Glassey conjecture for nontrapping obstacles

abstract:
  We verify the three-dimensional Glassey conjecture for exterior domain (M,
g), where the metric g is asymptotically Euclidean, provided that certain local
energy assumption is satisfied. The radial Glassey conjecture exterior to a
ball is also verified for dimension three or higher. The local energy
assumption is satisfied for many important cases, including exterior domain
with nontrapping obstacles and flat metric, exterior domain with star-shaped
obstacles and small asymptotically Euclidean metric, as well as the nontrapping
asymptotically Euclidean manifolds (R^n, g).


title: The Bondage Number of the Strong Product of a Complete Graph and a Path

abstract:
  The bondage number $b(G)$ of a graph $G$ is the cardinality of a minimum edge
set whose removal from $G$ results in a graph with the domination number
greater than that of $G$. It is a parameter to measure the vulnerability of a
communication network under link failure. In this paper, we obtain the exact
value of the bondage number of the strong product of a complete graph and a
path. That is, for any two integers $m\geq1$ and $n\geq2$, $b(K_{m}\boxtimes
P_{n})=\lceil\frac{m}{2}\rceil$ if $n\equiv 0$ (mod 3); $m$ if $n\equiv 2$ (mod
3); $\lceil\frac{3m}{2}\rceil$ if $n\equiv 1$ (mod 3). Furthermore, we
determine the exact value of the bondage number of the strong product of a
complete graph and a special starlike tree.


title: Axion inflation with gauge field production and primordial black holes

abstract:
  We study the process of primordial black hole (PBH) formation at the
beginning of radiation era for the cosmological scenario in which the inflaton
is a pseudo-Nambu-Goldstone boson (axion) and there is a coupling of the
inflaton with some gauge field. In this model inflation is accompanied by the
gauge quanta production and a strong rise of the curvature power spectrum
amplitude at small scales (along with non-Gaussianity) is predicted. We show
that data on PBH searches can be used for a derivation of essential constraints
on the model parameters in such an axion inflation scenario. We compare our
numerical results with the similar results published earlier, in the work by
Linde et al.


title: Advanced Data Processing in the Business Network System

abstract:
  The discovery, representation and reconstruction of Business Networks (BN)
from Network Mining (NM) raw data is a difficult problem for enterprises. This
is due to huge amounts of e.g. complex business processes within and across
enterprise boundaries, heterogeneous technology stacks, and fragmented data. To
remain competitive, visibility into the enterprise and partner networks on
different, interrelated abstraction levels is desirable.
  We show the query and data processing capabilities of a novel data discovery,
mining and network inference system, called Business Network System (BNS) that
reconstructs the BN--integration and business process networks - from raw data,
hidden in the enterprises' landscapes. The paper covers both the foundation and
the key data processing characteristics features of BNS, including its
underlying technologies, its overall system architecture, and data provenance
approach.


title:
Kitaev interactions between j=1/2 moments in honeycomb Na2IrO3 are large
  and ferromagnetic: insights from ab initio quantum chemistry calculations

abstract:
  Na$_2$IrO$_3$, a honeycomb 5$d^5$ oxide, has been recently identified as a
potential realization of the Kitaev spin lattice. The basic feature of this
spin model is that for each of the three metal-metal links emerging out of a
metal site, the Kitaev interaction connects only spin components perpendicular
to the plaquette defined by the magnetic ions and two bridging ligands. The
fact that reciprocally orthogonal spin components are coupled along the three
different links leads to strong frustration effects and nontrivial physics.
While the experiments indicate zigzag antiferromagnetic order in Na$_2$IrO$_3$,
the signs and relative strengths of the Kitaev and Heisenberg interactions are
still under debate. Herein we report results of ab initio many-body electronic
structure calculations and establish that the nearest-neighbor exchange is
strongly anisotropic with a dominant ferromagnetic Kitaev part, whereas the
Heisenberg contribution is significantly weaker and antiferromagnetic. The
calculations further reveal a strong sensitivity to tiny structural details
such as the bond angles. In addition to the large spin-orbit interactions, this
strong dependence on distortions of the Ir$_2$O$_2$ plaquettes singles out the
honeycomb 5$d^5$ oxides as a new playground for the realization of
unconventional magnetic ground states and excitations in extended systems.


title: Interpreting a nested Mach-Zehnder interferometer with classical optics

abstract:
  In an recent work with the title "Asking Photons Where They Have Been", Danan
et al. experimentally demonstrate an intriguing behavior of photons in an
interferometer [Phys. Rev. Lett. 111, 240402 (2013)]. In their words: "The
photons tell us that they have been in the parts of the interferometer through
which they could not pass." They interpret the results using the two-state
vector formalism of quantum theory and say that, although an explanation of the
experimental results in terms of classical electromagnetic waves in the
interferometer is possible (and they provide a partial description), it is not
so intuitive. Here we present a more detailed classical description of their
experimental results, showing that it is actually intuitive. The same
description is valid for the quantum wave function of the photons propagating
in the interferometer. In particular, we show that it is essential that the
wave propagates through all parts of the interferometer to describe the
experimental results. We hope that our work helps to give a deeper
understanding of these interesting experimental results.


title:
Distribution-free factor analysis - Estimation theory and applicability
  to high-dimensional data

abstract:
  We here provide a distribution-free approach to the random factor analysis
model. We show that it leads to the same estimating equations as for the
classical ML estimates under normality, but more easily derived, and valid also
in the case of more variables than observations ($p>n$). For this case we also
advocate a simple iteration method. In an illustration with $p=2000$ and $n=22$
it was seen to lead to convergence after just a few iterations. We show that
there is no reason to expect Heywood cases to appear, and that the factor
scores will typically be precisely estimated/predicted as soon as $p$ is large.
We state as a general conjecture that the nice behaviour is not despite $p>n$,
but because $p>n$.


title: Photo-Disintegration of Heavy Nuclei at the Core of Cen A

abstract:
  Fermi LAT has detected gamma ray emissions from the core of Cen A. More
recently, a new component in the gamma ray spectrum from the core has been
reported in the energy range of 4 GeV to tens of GeV. We show that the new
component and the HESS detected spectrum of gamma rays from the core at higher
energy have possibly a common origin in photo-disintegration of heavy nuclei.
Assuming the cosmic rays are mostly Fe nuclei inside the core and their
spectrum has a low energy cut-off at 52 TeV in the wind frame moving with a
Doppler factor 0.25 with respect to the observer on earth, the cosmic ray
luminosity required to explain the observed gamma ray flux above 1 GeV is found
to be $1.5\times 10^{43}$ erg/sec.


title:
A Novel Carrier Waveform Inter-Displacement Modulation Method in
  Underwater Communication Channel

abstract:
  As the main way of underwater wireless communication, underwater acoustic
communication is one of the focuses of ocean research. Compared with the free
space wireless communication channel, the underwater acoustic channel suffers
from more severe multipath effect, the less available bandwidth and the even
complex noise. The underwater acoustic channel is one of the most complicated
wireless communication channels. To achieve a reliable underwater acoustic
communication, Phase Shift Keying (PSK) modulation and Passive Time Reversal
Mirror (PTRM) equalization are considered to be a suitable scheme. However, due
to the serious distortion of the received signal caused by the channel, this
scheme suffers from a high Bit Error Rate (BER) under the condition of the low
Signal to Noise Ratio (SNR). To solve this problem, we proposes a Carrier
Waveform Inter-Displacement (CWID) modulation method based on the Linear
Frequency Modulation (LFM) PSK and PTRM scheme. The new communication scheme
reduces BER by increasing the difference from the carrier waveform for
different symbols. Simulation results show the effectiveness and superiority of
the proposed method.


title: Evaluating the Performance of IPTV over Fixed WiMAX

abstract:
  IEEE specifies different modulation techniques for WiMAX; namely, BPSK, QPSK,
16 QAM and 64 QAM. This paper studies the performance of Internet Protocol
Television (IPTV) over Fixed WiMAX system considering different combinations of
digital modulation. The performance is studied taking into account a number of
key system parameters which include the variation in the video coding,
path-loss, scheduling service classes different rated codes in FEC channel
coding. The performance study was conducted using OPNET simulation. The
performance is studied in terms of packet lost, packet jitter delay, end-to-end
delay, and network throughput. Simulation results show that higher order
modulation and coding schemes (namely, 16 QAM and 64 QAM) yield better
performance than that of QPSK.


title: The value function of an asymptotic exit-time optimal control problem

abstract:
  We consider a class of exit--time control problems for nonlinear systems with
a nonnegative vanishing Lagrangian. In general, the associated PDE may have
multiple solutions, and known regularity and stability properties do not hold.
In this paper we obtain such properties and a uniqueness result under some
explicit sufficient conditions. We briefly investigate also the infinite
horizon problem.


title: CAPTCHA Based on Human Cognitive Factor

abstract:
  A CAPTCHA (Completely Automated Public Turing test to tell Computers and
Humans Apart) is an automatic security mechanism used to determine whether the
user is a human or a malicious computer program. It is a program that generates
and grades tests that are human solvable, but intends to be beyond the
capabilities of current computer programs. CAPTCHA should be designed to be
very easy for humans but very hard for machines. Unfortunately, the existing
CAPTCHA systems while trying to maximize the difficulty for automated programs
to pass tests by increasing distortion or noise have consequently, made it also
very difficult for potential users. To address the issue, this paper addresses
an alternative form of CAPTCHA that provides a variety of questions from
mathematical, logical and general problems which only human can understand and
answer correctly in a given time. The proposed framework supports diversity in
choosing the questions to be answered and a user-friendly framework to the
users. A user-study is also conducted to judge the performance of the developed
system with different background. The study shows the efficacy of the
implemented system with a good level of user satisfaction over traditional
CAPTCHA available today.


title:
Distributed average tracking for multiple reference signals with general
  linear dynamics

abstract:
  This technical note studies the distributed average tracking problem for
multiple time-varying signals with general linear dynamics, whose reference
inputs are nonzero and not available to any agent in the network. In
distributed fashion, a pair of continuous algorithms with, respectively, static
and adaptive coupling strengths are designed. Based on the boundary layer
concept, the proposed continuous algorithm with static coupling strengths can
asymptotically track the average of the multiple reference signals without
chattering phenomenon. Furthermore, for the case of algorithms with adaptive
coupling strengths, the average tracking errors are uniformly ultimately
bounded and exponentially converge to a small adjustable bounded set. Finally,
a simulation example is presented to show the validity of the theoretical
results.


title:
Shape Primitive Histogram: A Novel Low-Level Face Representation for
  Face Recognition

abstract:
  We further exploit the representational power of Haar wavelet and present a
novel low-level face representation named Shape Primitives Histogram (SPH) for
face recognition. Since human faces exist abundant shape features, we address
the face representation issue from the perspective of the shape feature
extraction. In our approach, we divide faces into a number of tiny shape
fragments and reduce these shape fragments to several uniform atomic shape
patterns called Shape Primitives. A convolution with Haar Wavelet templates is
applied to each shape fragment to identify its belonging shape primitive. After
that, we do a histogram statistic of shape primitives in each spatial local
image patch for incorporating the spatial information. Finally, each face is
represented as a feature vector via concatenating all the local histograms of
shape primitives. Four popular face databases, namely ORL, AR, Yale-B and LFW-a
databases, are employed to evaluate SPH and experimentally study the choices of
the parameters. Extensive experimental results demonstrate that the proposed
approach outperform the state-of-the-arts.


title:
Containment Control of Linear Multi-Agent Systems with Multiple Leaders
  of Bounded Inputs Using Distributed Continuous Controllers

abstract:
  This paper considers the containment control problem for multi-agent systems
with general linear dynamics and multiple leaders whose control inputs are
possibly nonzero and time varying. Based on the relative states of neighboring
agents, a distributed static continuous controller is designed, under which the
containment error is uniformly ultimately bounded and the upper bound of the
containment error can be made arbitrarily small, if the subgraph associated
with the followers is undirected and for each follower there exists at least
one leader that has a directed path to that follower. It is noted that the
design of the static controller requires the knowledge of the eigenvalues of
the Laplacian matrix and the upper bounds of the leaders' control inputs. In
order to remove these requirements, a distributed adaptive continuous
controller is further proposed, which can be designed and implemented by each
follower in a fully distributed fashion. Extensions to the case where only
local output information is available are discussed.


title: Exceptional representations of quivers

abstract:
  Let Q be a connected directed quiver with n vertices. We show that Q is
representation-infinite if and only if there do exist n isomorphism classes of
exceptional modules of some fixed length at least 2.


title: Extinction times in the subcritical stochastic SIS logistic epidemic

abstract:
  Many real epidemics of an infectious disease are not straightforwardly super-
or sub-critical, and the understanding of epidemic models that exhibit such
complexity has been identified as a priority for theoretical work. We provide
insights into the near-critical regime by considering the stochastic SIS
logistic epidemic, a well-known birth-and-death chain used to model the spread
of an epidemic within a population of a given size $N$. We study the behaviour
of the process as the population size $N$ tends to infinity. Our results cover
the entire subcritical regime, including the "barely subcritical" regime, where
the recovery rate exceeds the infection rate by an amount that tends to 0 as $N
\to \infty$ but more slowly than $N^{-1/2}$. We derive precise asymptotics for
the distribution of the extinction time and the total number of cases
throughout the subcritical regime, give a detailed description of the course of
the epidemic, and compare to numerical results for a range of parameter values.
We hypothesise that features of the course of the epidemic will be seen in a
wide class of other epidemic models, and we use real data to provide some
tentative and preliminary support for this theory.


title: Classifying spaces of twisted loop groups

abstract:
  We study the classifying space of a twisted loop group $L_{\sigma}G$ where
$G$ is a compact Lie group and $\sigma$ is an automorphism of $G$ of finite
order modulo inner automorphisms. Equivalently, we study the $\sigma$-twisted
adjoint action of $G$ on itself. We derive a formula for the cohomology ring
$H^*(BL_{\sigma}G)$ and explicitly carry out the calculation for all
automorphisms of simple Lie groups. More generally, we derive a formula for the
equivariant cohomology of compact Lie group actions with constant rank
stabilizers.


title: On the history of the PMNS Matrix... with today's perspective

abstract:
  The conceptual basis for understanding the interplay of neutrino mass and
mixing for neutrino oscillations were paradoxically discussed in a period when
the prevailing view was that of massless neutrinos. The name of Bruno
Pontecorvo is associated to most of the components for this beautiful quantum
phenomenon: muon-electron universality, different neutrino flavours, mismatch
between weak interaction and mass eigenstates, neutrino oscillation
phenomenology, including flavour and Majorana transitions.


title: Detecting long-range dependence in non-stationary time series

abstract:
  An important problem in time series analysis is the discrimination between
non-stationarity and longrange dependence. Most of the literature considers the
problem of testing specific parametric hypotheses of non-stationarity (such as
a change in the mean) against long-range dependent stationary alternatives. In
this paper we suggest a simple approach, which can be used to test the
null-hypothesis of a general non-stationary short-memory against the
alternative of a non-stationary long-memory process. The test procedure works
in the spectral domain and uses a sequence of approximating tvFARIMA models to
estimate the time varying long-range dependence parameter. We prove uniform
consistency of this estimate and asymptotic normality of an averaged version.
These results yield a simple test (based on the quantiles of the standard
normal distribution), and it is demonstrated in a simulation study that -
despite of its semi-parametric nature - the new test outperforms the currently
available methods, which are constructed to discriminate between specific
parametric hypotheses of non-stationarity short- and stationarity long-range
dependence.


title: The Cayley isomorphism property for groups of order p^3q

abstract:
  For every prime $p > 3$ and for every prime $q>p^3$ we prove that
$\mathbb{Z}_q \times \mathbb{Z}_p^3$ is a DCI-group.


title:
Adaptive Coarse Graining, Environment, Strong Decoherence, and
  Quasiclassical Realms

abstract:
  Three ideas are introduced that when brought together characterize the
realistic quasiclassical realms of our quantum universe as particular kinds of
sets of alternative coarse-grained histories defined by quasiclassical
variables: (1) Branch dependent adaptive coarse grainings that can be close to
maximally refined and can simplify calculation. (2) Narrative coarse grainings
that describe how features of the universe change over time and allow the
construction of an environment. (3) A notion of strong decoherence that
characterizes realistic mechanisms of decoherence.


title: On the Parallel Repetition of Multi-Player Games: The No-Signaling Case

abstract:
  We consider the natural extension of two-player nonlocal games to an
arbitrary number of players. An important question for such nonlocal games is
their behavior under parallel repetition. For two-player nonlocal games, it is
known that both the classical and the non-signaling value of any game converges
to zero exponentially fast under parallel repetition, given that the game is
non-trivial to start with (i.e., has classical/non-signaling value <1). Very
recent results show similar behavior for the quantum value of a two-player game
under parallel repetition. For nonlocal games with three or more players, very
little is known up to present on their behavior under parallel repetition; this
is true for the classical, the quantum and the non-signaling value.
  In this work, we show a parallel repetition theorem for the non-signaling
value of a large class of multi-player games, for an arbitrary number of
players. Our result applies to all multi-player games for which all possible
combinations of questions have positive probability; this class in particular
includes all free games, in which the questions to the players are chosen
independently. Specifically, we prove that if the original game has a
non-signaling value smaller than 1, then the non-signaling value of the
$n$-fold parallel repetition is exponentially small in $n$.
  Our parallel repetition theorem for multi-player games is weaker than the
known parallel repetition results for two-player games in that the rate at
which the non-signaling value of the game decreases not only depends on the
non-signaling value of the original game (and the number of possible
responses), but on the complete description of the game. Nevertheless, we feel
that our result is a first step towards a better understanding of the parallel
repetition of nonlocal games with more than two players.


title:
Algorithms and formulas for conversion between system signatures and
  reliability functions

abstract:
  The concept of signature is a useful tool in the analysis of semicoherent
systems with continuous and i.i.d. component lifetimes, especially for the
comparison of different system designs and the computation of the system
reliability. For such systems, we provide conversion formulas between the
signature and the reliability function through the corresponding vector of
dominations and we derive efficient algorithms for the computation of any of
these concepts from the other. We also show how the signature can be easily
computed from the reliability function via basic manipulations such as
differentiation, coefficient extraction, and integration.


title:
Near field radiative thermal transfer between nano-structured periodic
  materials

abstract:
  This paper provides a method based on rigorous coupled wave analysis for the
calculation of the radiative thermal capacitance between a layer that is
patterned with arbitrary, periodically repeating features and a planar one.
This method is applied to study binary gratings and arrays of beams with a
rectangular cross section. The effects of the structure size and spacing on the
thermal capacitance are investigated. In all of these calculations, a
comparison is made with an effective medium theory which becomes increasingly
accurate as the structure sizes fall well below the relevant resonance
wavelength. Results show that new levels of control over the magnitude and
spectral contributions to thermal capacitance can be achieved with corrugated
structures relative to planar ones.


title:
Reflection resonances in surface-disordered waveguides: strong
  higher-order effects of the disorder

abstract:
  We study coherent wave scattering through waveguides with a step-like surface
disorder and find distinct enhancements in the reflection coefficients at
well-defined resonance values. Based on detailed numerical and analytical
calculations, we can unambiguously identify the origin of these reflection
resonances to be higher-order correlations in the surface disorder profile
which are typically neglected in similar studies of the same system. A
remarkable feature of this new effect is that it relies on the longitudinal
correlations in the step profile, although individual step heights are random
and thus completely uncorrelated. The corresponding resonances are very
pronounced and robust with respect to ensemble averaging, and lead to an
enhancement of wave reflection by more than one order of magnitude.


title:
Ultra high energy cosmic rays: implications of Auger data for source
  spectra and chemical composition

abstract:
  We use a kinetic-equation approach to describe the propagation of ultra high
energy cosmic ray protons and nuclei and calculate the expected spectra and
mass composition at the Earth for different assumptions on the source injection
spectra and chemical abundances. When compared with the spectrum, the
elongation rate $X_{max}(E)$ and dispersion $\sigma(X_{max})$ as observed with
the Pierre Auger Observatory, several important consequences can be drawn: a)
the injection spectra of nuclei must be very hard, $\sim E^{-\gamma}$ with
$\gamma\sim 1-1.6$; b) the maximum energy of nuclei of charge $Z$ in the
sources must be $\sim 5Z\times 10^{18}$ eV, thereby not requiring acceleration
to extremely high energies; c) the fit to the Auger spectrum can be obtained
only at the price of adding an {\it ad hoc} light extragalactic component with
a steep injection spectrum ($\sim E^{-2.7}$). In this sense, at the ankle
($E_{A}\approx 5\times 10^{18}$ eV) all the components are of extragalactic
origin, thereby suggesting that the transition from Galactic to extragalactic
cosmic rays occurs below the ankle. Interestingly, the additional light
extragalactic component postulated above compares well, in terms of spectrum
and normalization, with the one recently measured by KASCADE-Grande.


title:
What does the financial market pricing do? A simulation analysis with a
  view to systemic volatility, exuberance and vagary

abstract:
  Biondi et al. (2012) develop an analytical model to examine the emergent
dynamic properties of share market price formation over time, capable to
capture important stylized facts. These latter properties prove to be sensitive
to regulatory regimes for fundamental information provision, as well as to
market confidence conditions among actual and potential investors. Regimes
based upon mark-to-market (fair value) measurement of traded security, while
generating higher linear correlation between market prices and fundamental
signals, also involve higher market instability and volatility. These regimes
also incur more relevant episodes of market exuberance and vagary in some
regions of the market confidence space, where lower market liquidity further
occurs.

categories: q-fin.GN econ.GN physics.soc-ph q-fin.EC q-fin.PR q-fin.TR


title: Homogeneous Ricci solitons in low dimensions

abstract:
  In this article we classify expanding homogeneous Ricci solitons up to
dimension 5, according to their presentation as homogeneous spaces. We obtain
that they are all isometric to solvsolitons, and this in particular implies
that the generalized Alekseevskii conjecture holds in these dimensions. In
addition, we prove that the conjecture holds in dimension 6 provided the
transitive group is not semisimple.


title: Accretions of Various Types of Dark Energies onto Morris-Thorne Wormhole

abstract:
  In this work, we have studied accretion of the dark energies onto
Morris-Thorne wormhole. For quintessence like dark energy, the mass of the
wormhole decreases and phantom like dark energy, the mass of wormhole
increases. We have assumed two types of dark energy like variable modified
Chaplygin gas (VMCG) and generalized cosmic Chaplygin gas (GCCG). We have found
the expression of wormhole mass in both cases. We have found the mass of the
wormhole at late universe and this is finite. For our choices the parameters
and the function $B(a)$, these models generate only quintessence dark energy
(not phantom) and so wormhole mass decreases during evolution of the universe.
Next we have assumed 5 kinds of parametrizations of well known dark energy
models. These models generate both quintessence and phantom scenarios. So if
these dark energies accrete onto the wormhole, then for quintessence stage,
wormhole mass decreases upto a certain value (finite value) and then again
increases to infinite value for phantom stage during whole evolution of the
universe. We also shown these results graphically.


title: Generalized Ambiguity Decomposition for Understanding Ensemble Diversity

abstract:
  Diversity or complementarity of experts in ensemble pattern recognition and
information processing systems is widely-observed by researchers to be crucial
for achieving performance improvement upon fusion. Understanding this link
between ensemble diversity and fusion performance is thus an important research
question. However, prior works have theoretically characterized ensemble
diversity and have linked it with ensemble performance in very restricted
settings. We present a generalized ambiguity decomposition (GAD) theorem as a
broad framework for answering these questions. The GAD theorem applies to a
generic convex ensemble of experts for any arbitrary twice-differentiable loss
function. It shows that the ensemble performance approximately decomposes into
a difference of the average expert performance and the diversity of the
ensemble. It thus provides a theoretical explanation for the
empirically-observed benefit of fusing outputs from diverse classifiers and
regressors. It also provides a loss function-dependent, ensemble-dependent, and
data-dependent definition of diversity. We present extensions of this
decomposition to common regression and classification loss functions, and
report a simulation-based analysis of the diversity term and the accuracy of
the decomposition. We finally present experiments on standard pattern
recognition data sets which indicate the accuracy of the decomposition for
real-world classification and regression problems.


title: Understanding Branly's effect through Induced Tunnelling

abstract:
  At the end of the nineteenth century \'Edouard Branly discovered that the
electrical resistance of a granular metallic conductor could drop by several
orders of magnitude when excited by the electromagnetic field emitted by a
distant electrical spark [ ]. Despite the fact that this effect was used to
detect radio waves in the early days of wireless telegraphy and more recently,
studied in the field of granular materials, no satisfactory explanation of the
physical origin of the effect has been proposed. In this contribution, we
relate the Branly effect to the induced tunnelling effect first described by
Fran\c{c}ois Bardou and Dominique Boos\'e [ ].


title:
On the intersection of the spectrum of frequently hypercyclic operators
  with the unit circle

abstract:
  We exclude the existence of frequently hypercyclic operators that have a
spectrum contained in the closed unit disc and that intersects the unit circle
in only finitely many points under certain additional conditions. This extends
a result of S. Shkarin, which states that the spectrum of a frequently
hypercyclic operator cannot have isolated points.


title:
Bogomolov multiplier, double class-preserving automorphisms and modular
  invariants for orbifolds

abstract:
  We describe the group of braided tensor autoequivalences of the Drinfeld
centre of a finite group $G$ isomorphic to the identity functor (just as a
functor) as a semi-direct product $Aut^1_{br}(\Z(G))\ \simeq\
Out_{2-cl}(G)\ltimes B(G)\ $ of the group of double class preserving
automorphisms and the Bogomolov multiplier of $G$. The Bogomolov multiplier
$B(G)$ is the subgroup of its Schur multiplier $H^2(G,k^*)$ of classes
vanishing on abelian subgroups of $G$. We show that elements of
$Aut^1_{br}(\Z(G))$ give rise to different realisations of the charge
conjugation modular invariant for $G$-orbifolds of holomorphic conformal field
theories.


title:
Phonon self-energy and origin of anomalous neutron scattering spectra in
  SnTe and PbTe thermoelectrics

abstract:
  The anharmonic lattice dynamics of rock-salt thermoelectric compounds SnTe
and PbTe are investigated with inelastic neutron scattering (INS) and
first-principles calculations. The experiments show that, surprisingly,
although SnTe is closer to the ferroelectric instability, phonon spectra in
PbTe exhibit a more anharmonic character. This behavior is reproduced in
first-principles calculations of the temperature-dependent phonon self-energy.
Our simulations reveal how the nesting of phonon dispersions induces prominent
features in the self-energy, which account for the measured INS spectra and
their temperature dependence. We establish that the phase-space for
three-phonon scattering processes, rather than just the proximity to the
lattice instability, is the mechanism determining the complex spectrum of the
transverse-optical ferroelectric mode.


title: Tree-width and Logspace: Determinants and Counting Euler Tours

abstract:
  Motivated by the recent result of [EJT10] showing that MSO properties are
Logspace computable on graphs of bounded tree-width, we consider the complexity
of computing the determinant of the adjacency matrix of a bounded tree-width
graph and prove that it is L-complete. It is important to notice that the
determinant is neither an MSO-property nor counts the number of solutions of an
MSO-predicate. We extend this technique to count the number of spanning
arborescences and directed Euler tours in bounded tree-width digraphs, and
further to counting the number of spanning trees and the number of Euler tours
in undirected graphs, all in L. Notice that undirected Euler tours are not
known to be MSO-expressible and the corresponding counting problem is in fact
#P-hard for general graphs. Counting undirected Euler tours in bounded
tree-width graphs was not known to be polynomial time computable till very
recently Chebolu et al [CCM13] gave a polynomial time algorithm for this
problem (concurrently and independently of this work). Finally, we also show
some linear algebraic extensions of the determinant algorithm to show how to
compute the charcteristic polynomial and trace of the powers of a bounded
tree-width graph in L.


title:
Collaborative Discriminant Locality Preserving Projections With its
  Application to Face Recognition

abstract:
  We present a novel Discriminant Locality Preserving Projections (DLPP)
algorithm named Collaborative Discriminant Locality Preserving Projection
(CDLPP). In our algorithm, the discriminating power of DLPP are further
exploited from two aspects. On the one hand, the global optimum of class
scattering is guaranteed via using the between-class scatter matrix to replace
the original denominator of DLPP. On the other hand, motivated by collaborative
representation, an $L_2$-norm constraint is imposed to the projections to
discover the collaborations of dimensions in the sample space. We apply our
algorithm to face recognition. Three popular face databases, namely AR, ORL and
LFW-A, are employed for evaluating the performance of CDLPP. Extensive
experimental results demonstrate that CDLPP significantly improves the
discriminating power of DLPP and outperforms the state-of-the-arts.


title:
Key bifurcations of bursting polyrhythms in 3-cell central pattern
  generators

abstract:
  We identify and describe the key qualitative rhythmic states in various
3-cell network motifs of a multifunctional central pattern generator (CPG).
Such CPGs are neural microcircuits of cells whose synergetic interactions
produce multiple states with distinct phase-locked patterns of bursting
activity. To study biologically plausible CPG models, we develop a suite of
computational tools that reduce the problem of stability and existence of
rhythmic patterns in networks to the bifurcation analysis of fixed points and
invariant curves of a Poincar\'e return maps for phase lags between cells.
  We explore different functional possibilities for motifs involving symmetry
breaking and heterogeneity. This is achieved by varying coupling properties of
the synapses between the cells and studying the qualitative changes in the
structure of the corresponding return maps. Our findings provide a systematic
basis for understanding plausible biophysical mechanisms for the regulation of
rhythmic patterns generated by various CPGs in the context of motor control
such as gait-switching in locomotion. Our analysis does not require knowledge
of the equations modeling the system and provides a powerful qualitative
approach to studying detailed models of rhythmic behavior. Thus, our approach
is applicable to a wide range of biological phenomena beyond motor control.


title: Generalized Contact Geometry and T-Duality

abstract:
  We study generalized almost contact structures on odd-dimensional manifolds.
We introduce a notion of integrability and show that the class of these
structures is closed under symmetries of the Courant-Dorfman bracket, including
T-duality. We define a notion of geometric type for generalized almost contact
structures, and study its behavior under T-duality.


title: Topological aperiodicity for product systems over semigroups of Ore type

abstract:
  We prove a version of uniqueness theorem for Cuntz-Pimsner algebras of
discrete product systems over semigroups of Ore type. To this end, we introduce
Doplicher-Roberts picture of Cuntz-Pimsner algebras, and the semigroup dual to
a product system of 'regular' C*-correspondences. Under a certain aperiodicity
condition on the latter, we obtain the uniqueness theorem and a simplicity
criterion for the algebras in question. These results generalize the
corresponding ones for crossed products by discrete groups, due to Archbold and
Spielberg, and for Exel's crossed products, due to Exel and Vershik. They also
give interesting conditions for topological higher rank graphs and $P$-graphs,
and apply to the new Cuntz C*-algebra $\mathcal{Q}_\mathbb{N}$ arising from the
"$ax+b$"-semigroup over $\mathbb{N}$.


title:
Revisiting several problems and algorithms in continuous location with
  $\ell_p$ norms

abstract:
  This paper addresses the general continuous single facility location problems
in finite dimension spaces under possibly different $\ell_p$ norms in the
demand points. We analyze the difficulty of this family of problems and revisit
convergence properties of some well-known algorithms. The ultimate goal is to
provide a common approach to solve the family of continuous $\ell_p$ ordered
median location problems in dimension $d$ (including of course the $\ell_p$
minisum or Fermat-Weber location problem for any $p\ge 1$). We prove that this
approach has a polynomial worse case complexity for monotone lambda weights and
can be also applied to constrained and even non-convex problems.


title: Heavy Quark Diffusion in Strongly Coupled Anisotropic Plasmas

abstract:
  We study the Langevin diffusion of a relativistic heavy quark in anisotropic
strongly coupled theories in the local limit. Firstly, we use the axion
space-dependent deformed anisotropic N=4 sYM, where the geometry anisotropy is
always prolate, while the pressure anisotropy may be prolate or oblate. For
motion along the anisotropic direction we find that the effective temperature
for the quark can be larger than the heat bath temperature, in contrast to what
happens in the isotropic theory. The longitudinal and transverse Langevin
diffusion coefficients depend strongly on the anisotropy, the direction of
motion and the transverse direction considered. We analyze the anisotropy
effects to the coefficients and compare them to each other and to them of the
isotropic theory. To examine the dependence of the coefficients on the type of
the geometry, we consider another bottom-up anisotropic model. Changing the
geometry from prolate to oblate, certain diffusion coefficients interchange
their behaviors. In both anisotropic backgrounds we find cases that the
transverse diffusion coefficient is larger than the longitudinal, but we find
no negative excess noise.


title:
The DtN nonreflecting boundary condition for multiple scattering
  problems in the half-plane

abstract:
  The multiple-Dirichlet-to-Neumann (multiple-DtN) non-reflecting boundary
condition is adapted to acoustic scattering from obstacles embedded in the
half-plane. The multiple-DtN map is coupled with the method of images as an
alternative model for multiple acoustic scattering in the presence of
acoustically soft and hard plane boundaries. As opposed to the current practice
of enclosing all obstacles with a large semicircular artificial boundary that
contains portion of the plane boundary, the proposed technique uses small
artificial circular boundaries that only enclose the immediate vicinity of each
obstacle in the half-plane. The adapted multiple-DtN condition is
simultaneously imposed in each of the artificial circular boundaries. As a
result the computational effort is significantly reduced. A computationally
advantageous boundary value problem is numerically solved with a finite
difference method supported on boundary-fitted grids. Approximate solutions to
problems involving two scatterers of arbitrary geometry are presented. The
proposed numerical method is validated by comparing the approximate and exact
far-field patterns for the scattering from a single and from two circular
obstacles in the half-plane.


title: Nuclear Physics Experiments with Ion Storage Rings

abstract:
  In the last two decades a number of nuclear structure and astrophysics
experiments were performed at heavy-ion storage rings employing unique
experimental conditions offered by such machines. Furthermore, building on the
experience gained at the two facilities presently in operation, several new
storage ring projects were launched worldwide. This contribution is intended to
provide a brief review of the fast growing field of nuclear structure and
astrophysics research at storage rings.


title: Covering with Excess One: Seeing the Topology

abstract:
  We have initiated the study of topology of the space of coverings on grid
domains. The space has the following constraint: while all the covering agents
can move freely (we allow overlapping) on the domain, their union must cover
the whole domain. A minimal number $N$ of the covering agents is required for a
successful covering of the domain. In this paper, we demonstrate beautiful
topological structures of this space on grid domains in 2D with $N+1$
coverings, the topology of the space has the homotopy type of $1$ dimensional
complex, regardless of the domain shape. We also present the Euler
characteristic formula which connects the topology of the space with that of
the domain itself.


title:
Gravitational energy, gravitational pressure, and the thermodynamics of
  a charged black hole in teleparallel gravity

abstract:
  We investigate, in the case of a Reissner-Nordstr\"om black hole, the
definitions of gravitational energy and gravitational pressure that naturally
arise in the framework of the Teleparallel Equivalent of General Relativity. In
particular, we calculate the gravitational energy enclosed by the event horizon
of the black hole, E, and the radial pressure over it, p. With these quantities
we then analyse the thermodynamic relation dE + pdV (as p turns out to be a
density, dV is actually given by dV = dr d\theta d\phi, in spherically-type
coordinates). We compare the latter with the standard first law of black hole
dynamics. Also, by identifying TdS = dE + pdV, we comment on a possible
modification of the standard, Bekenstein-Hawking entropy-area relation due to
gravitational energy and gravitational pressure of the black hole. The
infinitesimal variations in question refer to the Penrose process for a
Reissner-Nordstr\"om black hole.


title: Parallel Markov Chain Monte Carlo

abstract:
  Markov chain Monte Carlo is an inherently serial algorithm. Although
likelihood calculations for individual steps can sometimes be parallelized, the
serial evolution of the process is widely viewed as incompatible with
parallelization, offering no speedup for samplers which require large numbers
of iterations to converge to equilibrium. We provide a methodology for
parallelizing Markov chain Monte Carlo across large numbers of independent,
asynchronous processors. Our approach uses a partitioning and weight estimation
scheme to combine independent simulations run on separate processors into
rigorous Monte Carlo estimates. The method is originally motivated by sampling
multimodal target distributions, where we see an exponential speedup in running
time. However we show that the approach is general-purpose and applicable to
all Markov chain Monte Carlo simulations, and demonstrate speedups proportional
to the number of available processors on slowly mixing chains with unimodal
target distributions. The approach is simple and easy to implement, and
suggests additional directions for further research.


title: Malliavin weight sampling: a practical guide

abstract:
  Malliavin weight sampling (MWS) is a stochastic calculus technique for
computing the derivatives of averaged system properties with respect to
parameters in stochastic simulations, without perturbing the system's dynamics.
It applies to systems in or out of equilibrium, in steady state or
time-dependent situations, and has applications in the calculation of response
coefficients, parameter sensitivities and Jacobian matrices for gradient-based
parameter optimisation algorithms. The implementation of MWS has been described
in the specific contexts of kinetic Monte Carlo and Brownian dynamics
simulation algorithms. Here, we present a general theoretical framework for
deriving the appropriate MWS update rule for any stochastic simulation
algorithm. We also provide pedagogical information on its practical
implementation.


title:
Effect of anisotropic spin absorption on the Hanle effect in lateral
  spin valves

abstract:
  We have succeeded in fully describing dynamic properties of spin current
including the different spin absorption mechanism for longitudinal and
transverse spins in lateral spin valves, which enables to elucidate intrinsic
spin transport and relaxation mechanism in the nonmagnet. The deduced spin
lifetimes are found independent of the contact type. From the transit-time
distribution of spin current extracted from the Fourier transform in Hanle
measurement data, the velocity of the spin current in Ag with Py/Ag Ohmic
contact turns out much faster than that expected from the widely used model.


title: Element-wise uniqueness, prior knowledge, and data-dependent resolution

abstract:
  Techniques for finding regularized solutions to underdetermined linear
systems can be viewed as imposing prior knowledge on the unknown vector. The
success of modern techniques, which can impose priors such as sparsity and
non-negativity, is the result of advances in optimization algorithms to solve
problems which lack closed-form solutions. Techniques for characterization and
analysis of the system to determined when information is recoverable, however,
still typically rely on closed-form solution techniques such as singular value
decomposition or a filter cutoff, for example. In this letter we pose
optimization approaches to broaden the approach to system characterization. We
start by deriving conditions for when each unknown element of a system admits a
unique solution, subject to a broad class of types of prior knowledge. With
this approach we can pose a convex optimization problem to find "how unique"
each element of the solution is, which may be viewed as a generalization of
resolution to incorporate prior knowledge. We find that the result varies with
the unknown vector itself, i.e. is data-dependent, such as when the sparsity of
the solution improves the chance it can be uniquely reconstructed. The approach
can be used to analyze systems on a case-by-case basis, estimate the amount of
important information present in the data, and quantitatively understand the
degree to which the regularized solution may be trusted.


title: Some geometric facets of the Langlands correspondence for real groups

abstract:
  This note concerns geometric aspects of the local Langlands correspondence
for real groups as extended from Langlands' original work by
Adams-Barbasch-Vogan, and further (conjectural) formulations by W. Soergel. The
main result concerns purity (in the sense of weights in Hodge theory) of
equivariant extension groups between simple objects on the Adams-Barbasch-Vogan
geometric parameter space (for trivial infinitesimal character).


title: Asymptotic Behavior of neural fields in an unbounded domain

abstract:
  In this paper, we prove the existence of a compact global attractor for the
flow generated by equation
  $$
  \frac{\partial u}{\partial t}(x,t)+u(x,t)= \int_{\mathbb{R}^{N}}J(x-y)(f(
u(y,t))dy+ h, \quad h > 0, \quad x\in \mathbb{R}^{N}, \quad t\in\mathbb{R}_{+}
  $$ in the weight space $L^{p}(\mathbb{R}^{N}, \rho)$. We also give uniform
estimates on the size of the attractor and we exhibit a Lyapunov functional to
the flow generated by this equation


title:
A General Algorithm for Deciding Transportability of Experimental
  Results

abstract:
  Generalizing empirical findings to new environments, settings, or populations
is essential in most scientific explorations. This article treats a particular
problem of generalizability, called "transportability", defined as a license to
transfer information learned in experimental studies to a different population,
on which only observational studies can be conducted. Given a set of
assumptions concerning commonalities and differences between the two
populations, Pearl and Bareinboim (2011) derived sufficient conditions that
permit such transfer to take place. This article summarizes their findings and
supplements them with an effective procedure for deciding when and how
transportability is feasible. It establishes a necessary and sufficient
condition for deciding when causal effects in the target population are
estimable from both the statistical information available and the causal
information transferred from the experiments. The article further provides a
complete algorithm for computing the transport formula, that is, a way of
combining observational and experimental information to synthesize bias-free
estimate of the desired causal relation. Finally, the article examines the
differences between transportability and other variants of generalizability.


title: Artificial Gauge Fields and Spin-Orbit Couplings in Cold Atom Systems

abstract:
  This article is a report of Projet bibliographique of M1 at \'Ecole Normale
Sup\'erieure. In this article we reviewed the historical developments in
artificial gauge fields and spin-orbit couplings in cold atom systems. We
resorted to origins of literatures to trace the ideas of the developments. For
pedagogical purposes, we tried to work out examples carefully and clearly, to
verified the validity of various approximations and arguments in detail, and to
give clear physical and mathematical pictures of the problems that we
discussed. The first part of this article introduced the fundamental concepts
of Berry phase and Jaynes-Cummings model. The second part reviewed two schemes
to generate artificial gauge fields with N-pod scheme in cold atom systems. The
first one is based on dressed-atom picture which provide a method to generate
non-Abelian gauge fields with dark states. The second one is about rotating
scheme which is achieved earlier historically. Non-Abelian gauge field
inevitably leads to spin-orbit coupling. We reviewed some developments in
achieve spin-orbital coupling theoretically and experimentally. The fourth part
was devoted to recently developed idea of optical flux lattice that provides a
possibility to reach the strongly correlated regime in cold atom systems. We
developed a geometrical interpretation based on Cooper's theory. Some useful
formulae and their proofs were listed in the Appendix.


title: 1-Quasiconformal maps on Carnot groups with reducible first layer

abstract:
  For the result on 1-quasiconformal maps, see the paper by Cowling and
Ottazzi. The result on quasiconformal maps on Carnot groups with reducible
first layer will appear in a forthcoming paper by Enrico Le Donne and Xiangdong
Xie.


title:
A Possible Explanation of Low Energy $\gamma$-ray Excess from Galactic
  Centre and Fermi Bubble by a Dark Matter Model with Two Real Scalars

abstract:
  We promote the idea of multi-component Dark Matter (DM) to explain results
from both direct and indirect detection experiments. In these models as
contribution of each DM candidate to relic abundance is summed up to meet
WMAP/Planck measurements of $\Omega_{\rm DM}$, these candidates have larger
annihilation cross-sections compared to the single-component DM models. This
results in larger $\gamma$-ray flux in indirect detection experiments of DM. We
illustrate this fact by introducing an extra scalar to the popular single real
scalar DM model. We also present detailed calculations for the vacuum stability
bounds, perturbative unitarity and triviality constraints on this model. As
direct detection experimental results still show some conflict, we kept our
options open, discussing different scenarios with different DM mass zones. In
the framework of our model we make an interesting observation: The existing
direct detection experiments like CDMS II, CoGeNT, CRESST II, XENON 100 or LUX
together with the observation of excess low energy $\gamma$-ray from Galactic
Centre and Fermi Bubble by FGST already have the capability to distinguish
between different DM halo profiles.


title:
Possible assignments of the $X(3872)$, $Z_c(3900)$ and $Z_b(10610)$ as
  axial-vector molecular states

abstract:
  In this article, we construct both the color singlet-singlet type and
octet-octet type currents to interpolate the $X(3872)$, $Z_c(3900)$,
$Z_b(10610)$, and calculate the vacuum condensates up to dimension-10 in the
operator product expansion. Then we study the axial-vector hidden charmed and
hidden bottom molecular states with the QCD sum rules, explore the energy scale
dependence of the QCD sum rules for the heavy molecular states in details, and
use the formula $\mu=\sqrt{M^2_{X/Y/Z}-(2{\mathbb{M}}_Q)^2}$ with the effective
masses ${\mathbb{M}}_Q$ to determine the energy scales. The numerical results
support assigning the $X(3872)$, $Z_c(3900)$, $Z_b(10610)$ as the color
singlet-singlet type molecular states with $J^{PC}=1^{++}$, $1^{+-}$, $1^{+-}$,
respectively, more theoretical and experimental works are still needed to
distinguish the molecule and tetraquark assignments; while there are no
candidates for the color octet-octet type molecular states.