title:
Kalman-filter-based track fitting in non-uniform magnetic field with
  segment-wise helical track model

abstract:
  In the future International Linear Collider (ILC) experiment, high
performance tracking is essential to its physics program including precision
Higgs studies. One of major challenges for a detector such as the proposed
International Large Detector (ILD) is to provide excellent momentum resolution
in a magnetic filed with small (but non-negligible) non-uniformity. The
non-uniform magnetic field implies deviation from a helical track and hence
requires the extension of a helical track model used for track fitting in a
uniform magnetic field. In this paper, a segment-wise helical track model is
introduced as such an extension. The segment-wise helical track model
approximates the magnetic field between two nearby measurement sites to be
uniform and steps between the two sites along a helix. The helix frame is then
transformed according to the new magnetic field direction for the next step, so
as to take into account the non-uniformity of the magnetic field. Details of
the algorithm and mathematical aspects of the segment-wise helical track model
in a Kalman-filter-based track fitting in the non-uniform magnetic field are
elaborated. The new track model is implemented and successfully tested in the
framework of the Kalman filter tracking software package, KalTest, which was
originally developed for tracking in a uniform magnetic field.


title:
Amplitude Death: The cessation of oscillations in coupled nonlinear
  dynamical systems

abstract:
  Here we extend a recent review (Physics Reports {\bf 521}, 205 (2012)) of
amplitude death, namely the suppression of oscillations due to the coupling
interactions between nonlinear dynamical systems. This is an important emergent
phenomenon that is operative under a variety of scenarios. We summarize results
of recent studies that have significantly added to our understanding of the
mechanisms that underlie the process, and also discuss the phase--flip
transition, a characteristic and unusual effect that occurs in the transient
dynamics as the oscillations die out.


title:
Charm quarks in medium and their contribution to di-electron spectra in
  relativistic heavy ion collisions

abstract:
  We study the dynamics of charm quarks in the partonic medium and its
implication to the di-electron spectra in high energy heavy ion collisions. The
charm quarks traversing a thermal medium is simulated by the relativistic
Langevin equation for elastic scatterings of charm quarks by thermal partons in
an expanding fireball. The transport coefficients of charm quarks are
calculated by the in-medium T-matrix method, where a static heavy quark
potential is used with parameters fitted by the lattice QCD results. The
di-electron invariant mass spectra are computed in most central collisions and
are compared to the STAR data. The angular correlations of di-electrons are
almost the same in $p+p$ and Au+Au collisions in the mass range
$1.1<M<2.5~\mathrm{GeV/c^2}$ with the back-to-back feature. This means that the
angular correlation is intact even with medium interaction at the RHIC energy.


title:
Multigame Effect in Finite Populations Induces Strategy Linkage Between
  Two Games

abstract:
  Evolutionary game dynamics with two 2-strategy games in a finite population
has been investigated in this study. Traditionally, frequency-dependent
evolutionary dynamics are modeled by deterministic replicator dynamics under
the assumption that the population size is infinite. However, in reality,
population sizes are finite. Recently, stochastic processes in finite
populations have been introduced into evolutionary games in order to study
finite size effects in evolutionary game dynamics. However, most of these
studies focus on populations playing only single games. In this study, we
investigate a finite population with two games and show that a finite
population playing two games tends to evolve toward a specific direction to
form particular linkages between the strategies of the two games.


title:
Coset construction of logarithmic minimal models: branching rules and
  branching functions

abstract:
  Working in the Virasoro picture, it is argued that the logarithmic minimal
models LM(p,p')=LM(p,p';1) can be extended to an infinite hierarchy of
logarithmic conformal field theories LM(p,p';n) at higher fusion levels
n=1,2,3,.... From the lattice, these theories are constructed by fusing
together n x n elementary faces of the appropriate LM(p,p') models. It is
further argued that all of these logarithmic theories are realized as diagonal
cosets (A_1^{(1)})_k \oplus (A_1^{(1)})_n / (A_1^{(1)})_{k+n} where n is the
integer fusion level and k=np/(p'-p)-2 is a fractional level. These cosets
mirror the cosets of the higher fusion level minimal models of the form
M(m,m';n), but are associated with certain reducible representations. We
present explicit branching rules for characters in the form of multiplication
formulas arising in the logarithmic limit of the usual Goddard-Kent-Olive coset
construction of the non-unitary minimal models M(m,m';n). The limiting
branching functions play the role of Kac characters for the LM(p,p';n)
theories.

categories: hep-th cond-mat.stat-mech math-ph math.MP


title: Skew-spectra and skew energy of various products of graphs

abstract:
  Given a graph $G$, let $G^\sigma$ be an oriented graph of $G$ with the
orientation $\sigma$ and skew-adjacency matrix $S(G^\sigma)$. Then the spectrum
of $S(G^\sigma)$ consisting of all the eigenvalues of $S(G^\sigma)$ is called
the skew-spectrum of $G^\sigma$, denoted by $Sp(G^\sigma)$. The skew energy of
the oriented graph $G^\sigma$, denoted by $\mathcal{E}_S(G^\sigma)$, is defined
as the sum of the norms of all the eigenvalues of $S(G^\sigma)$. In this paper,
we give orientations of the Kronecker product $H\otimes G$ and the strong
product $H\ast G$ of $H$ and $G$ where $H$ is a bipartite graph and $G$ is an
arbitrary graph. Then we determine the skew-spectra of the resultant oriented
graphs. As applications, we construct new families of oriented graphs with
maximum skew energy. Moreover, we consider the skew energy of the orientation
of the lexicographic product $H[G]$ of a bipartite graph $H$ and a graph $G$.


title:
On Majorana representations of the group $3^2{:}2$ of 3C-pure type and
  the corresponding vertex operator algebras

abstract:
  In this article, we study Griess algebras and vertex operator subalgebras
generated by Ising vectors in a moonshine type VOA such that the subgroup
generated by the corresponding Miyamoto involutions has the shape $3^2{:}2$ and
any two Ising vectors generate a 3C subVOA $U_{3C}$. We show that such a Griess
algebra is uniquely determined, up to isomorphisms. The structure of the
corresponding vertex operator algebra is also discussed. In addition, we give a
construction of such a VOA inside the lattice VOA $V_{E_8^3}$, which gives an
explicit example for Majorana representations of the group $3^2{:}2$ of 3C-pure
type.


title:
Weyl groups and vertex operator algebras generated by Ising vectors
  satisfying $(2B,3C)$ condition

abstract:
  In this article, we construct explicitly certain moonshine type vertex
operator algebras generated by a set of Ising vectors $I$ such that
  (1) for any $e\neq f\in I$, the subVOA $\mathrm{VOA}(e,f)$ generated by $e$
and $f$ is isomorphic to either $U_{2B}$ or $U_{3C}$; and
  (2)the subgroup generated by the corresponding Miyamoto involutions
$\{\tau_e|\,e\in I\}$ is isomorphic to the Weyl group of a root system of type
$A_n$, $D_n$, $E_6$, $E_7$ or $E_8$.
  The structures of the corresponding vertex operator algebras and their Griess
algebras are also studied. In particular, the central charge of these vertex
operator algebras are determined.


title: Operator log-convex functions and f-divergence functional

abstract:
  We present a characterization of operator log-convex functions by using
positive linear mappings. Moreover, we study the non-commutative f-divergence
functional of operator log-convex functions. In particular, we prove that f is
operator log-convex if and only if the non-commutative f-divergence functional
is operator log-convex in its first variable and operator convex in its second
variable.


title: Optimization problem under change of regime of interest rate

abstract:
  In this paper, we study the classical problem of maximization of the sum of
the utility of the terminal wealth and the utility of the consumption, in a
case where a sudden jump in the risk-free interest rate creates incompleteness.
The value function of the dual problem is proved to be solution of a BSDE and
the duality between the primal and the dual value functions is exploited to
study the BSDE associated to the primal problem.


title: Prompt Upsilon(nS) production at the LHC in the Regge limit of QCD

abstract:
  We study prompt Upsilon(nS) hadroproduction (n=1,2,3) invoking the hypothesis
of gluon Reggeization in t-channel exchanges at high energy and the
factorization formalism of nonrelativistic quantum chromodynamics at leading
order in the strong-coupling constant alpha_s and the relative velocity v of
the bound quarks. The transverse-momentum distributions of prompt
Upsilon(nS)-meson production measured by the ATLAS Collaboration at the CERN
LHC are fitted to obtain the color-octet nonperturbative long-distance matrix
elements, which are used to predict prompt Upsilon(nS) production spectra
measured by the CMS and LHCb Collaborations. At the numerical calculation, we
adopt the Kimber-Martin-Ryskin prescription to derive unintegrated gluon
distribution function of the proton from its collinear counterpart, for which
we use the Martin-Roberts-Stirling-Thorne set. We find good agreement with
measurements by the ATLAS, CMS and LHCb Collaborations at the LHC at the
hadronic c.m. energy sqrt S=7 TeV as well as with measurements by the CDF
Collaboration at the Fermilab Tevatron.


title: Robust Hyperspectral Unmixing with Correntropy based Metric

abstract:
  Hyperspectral unmixing is one of the crucial steps for many hyperspectral
applications. The problem of hyperspectral unmixing has proven to be a
difficult task in unsupervised work settings where the endmembers and
abundances are both unknown. What is more, this task becomes more challenging
in the case that the spectral bands are degraded with noise. This paper
presents a robust model for unsupervised hyperspectral unmixing. Specifically,
our model is developed with the correntropy based metric where the non-negative
constraints on both endmembers and abundances are imposed to keep physical
significance. In addition, a sparsity prior is explicitly formulated to
constrain the distribution of the abundances of each endmember. To solve our
model, a half-quadratic optimization technique is developed to convert the
original complex optimization problem into an iteratively re-weighted NMF with
sparsity constraints. As a result, the optimization of our model can adaptively
assign small weights to noisy bands and give more emphasis on noise-free bands.
In addition, with sparsity constraints, our model can naturally generate sparse
abundances. Experiments on synthetic and real data demonstrate the
effectiveness of our model in comparison to the related state-of-the-art
unmixing models.


title: BRST quantization of a sixth-order derivative scalar field theory

abstract:
  We study a sixth order derivative scalar field model in Minkowski spacetime
as a toy model of higher-derivative critical gravity theories. This model is
consistently quantized when using the Becchi-Rouet-Stora-Tyutin (BRST)
quantization scheme even though it does not show gauge symmetry manifestly.
Imposing a BRST quartet generated by two scalars and ghosts, there remains a
non-trivial subspace with positive norm. This might be interpreted as a
Minkowskian dual version of the unitary truncation in the logarithmic conformal
field theory.


title:
Enhancement of DFT-calculations at Petascale: Nuclear Magnetic
  Resonance, Hybrid Density Functional Theory and Car-Parrinello calculations

abstract:
  One of the most promising techniques used for studying the electronic
properties of materials is based on Density Functional Theory (DFT) approach
and its extensions.
  DFT has been widely applied in traditional solid state physics problems where
periodicity and symmetry play a crucial role in reducing the computational
workload. With growing compute power capability and the development of improved
DFT methods, the range of potential applications is now including other
scientific areas such as Chemistry and Biology. However, cross disciplinary
combinations of traditional Solid-State Physics, Chemistry and Biology
drastically improve the system complexity while reducing the degree of
periodicity and symmetry. Large simulation cells containing of hundreds or even
thousands of atoms are needed to model these kind of physical systems. The
treatment of those systems still remains a computational challenge even with
modern supercomputers. In this paper we describe our work to improve the
scalability of Quantum ESPRESSO \cite{Quantum-Espresso} for treating very large
cells and huge numbers of electrons. To this end we have introduced an extra
level of parallelism, over \emph{\emph{electronic bands}}, in three kernels for
solving computationally expensive problems: the Sternheimer equation solver
(Nuclear Magnetic Resonance, package QE-GIPAW), the Fock operator builder
(electronic ground-state, package PWscf) and most of the Car-Parrinello
routines (Car-Parrinello dynamics, package CP). Final benchmarks show our
success in computing the Nuclear Magnetic Response (NMR) chemical shift of a
large biological assembly, the electronic structure of defected amorphous
silica with hybrid exchange-correlation functionals and the equilibrium atomic
structure of height Porphyrins anchored to a Carbon Nanotube, on many thousands
of CPU cores.


title:
Spin-resoloved chiral condensate as a spin-unpolarized \nu=0 quantum
  Hall state in graphene

abstract:
  Motivated by the recent experiments indicating a spin-unpolarized \nu=0
quantum Hall state in graphene, we theoretically investigate the ground state
based on the many-body problem projected onto the n=0 Landau level. For an
effective model with the on-site Coulomb repulsion and antiferromagnetic
exchange couplings, we show that the ground state is a doubly-degenerate
spin-resolved chiral condensate in which all the zero-energy states with up
spin are condensed into one chirality, while those with down spin to the other.
This can be exactly shown for an Ising-type exchange interaction. The charge
gap due to the on-site repulsion in the ground state is shown to grow linearly
with the magnetic field, in qualitative agreement with the experiments.


title: Sequential Weak Approximation for Maps of Finite Hessian Energy

abstract:
  Consider the space $W^{2,2}(\Omega;N)$ of second order Sobolev mappings $\ v\
$ from a smooth domain $\Omega\subset\R^m$ to a compact Riemannian manifold $N$
whose Hessian energy $\int_\Omega |\nabla^2 v|^2\, dx$ is finite. Here we are
interested in relations between the topology of $N$ and the $W^{2,2}$ strong or
weak approximability of a $W^{2,2}$ map by a sequence of smooth maps from
$\Omega$ to $N$. We treat in detail $W^{2,2}(\B^5,S^3)$ where we establish the
\underline{sequential weak} $W^{2,2}$ density of
$W^{2,2}(\B^5,S^3)\cap{\mathcal C}^\infty$. The strong $W^{2,2}$
approximability of higher order Sobolev maps has been studied in the recent
preprint \cite{BPV} of P. Bousquet, A. Ponce, and J. Van Schaftigen. For an
individual map $v\in W^{2,2}(\B^5,S^3)$, we define a number $L(v)$ which is
approximately the total length required to connect the isolated singularities
of a strong approximation $u$ of $v$ either to each other or to $\p\B^5$. Then
$L(v)=0$ if and only if $v$ admits $W^{2,2}$ strongly approximable by smooth
maps. Our critical result, obtained by constructing specific curves connecting
the singularities of $u$, is the bound $\ L(u)\leq c\int_{\B^5}|\nabla^2 u|^2\,
dx\ $. This allows us to construct, for the given Sobolev map $v\in
W^{2,2}(\B^5,S^3)$, the desired $W^{2,2}$ weakly approximating sequence of
smooth maps. To find suitable connecting curves for $u$, one uses the twisting
of a $u$ pull-back normal framing of a suitable level surface of $u$


title:
A hybrid approach for semantic enrichment of MathML mathematical
  expressions

abstract:
  In this paper, we present a new approach to the semantic enrichment of
mathematical expression problem. Our approach is a combination of statistical
machine translation and disambiguation which makes use of surrounding text of
the mathematical expressions. We first use Support Vector Machine classifier to
disambiguate mathematical terms using both their presentation form and
surrounding text. We then use the disambiguation result to enhance the semantic
enrichment of a statistical-machine-translation-based system. Experimental
results show that our system archives improvements over prior systems.


title:
Hadron Transverse Momentum Distributions in Muon Deep Inelastic
  Scattering at 160 GeV/$c$

abstract:
  Multiplicities of charged hadrons produced in deep inelastic muon scattering
off a $^6$LiD target have been measured as a function of the DIS variables
$x_{Bj}$, $Q^2$, $W^2$ and the final state hadron variables $p_T$ and $z$. The
$p_T^2$ distributions are fitted with a single exponential function at low
values of $p_T^2$ to determine the dependence of $\langle p_T^2 \rangle$ on
$x_{Bj}$, $Q^2$, $W^2$ and $z$. The $z$-dependence of $\langle p_T^2 \rangle$
is shown to be a potential tool to extract the average intrinsic transverse
momentum squared of partons, $\langle k_{\perp}^2 \rangle$, as a function of
$x_{Bj}$ and $Q^2$ in a leading order QCD parton model.


title:
The linear noise approximation for reaction-diffusion systems on
  networks

abstract:
  Stochastic reaction-diffusion models can be analytically studied on complex
networks using the linear noise approximation. This is illustrated through the
use of a specific stochastic model, which displays traveling waves in its
deterministic limit. The role of stochastic fluctuations is investigated and
shown to drive the emergence of stochastic waves beyond the region of the
instability predicted from the deterministic theory. Simulations are performed
to test the theoretical results and are analyzed via a generalized Fourier
transform algorithm. This transform is defined using the eigenvectors of the
discrete Laplacian defined on the network. A peak in the numerical power
spectrum of the fluctuations is observed in quantitative agreement with the
theoretical predictions.


title: Handelman's hierarchy for the maximum stable set problem

abstract:
  The maximum stable set problem is a well-known NP-hard problem in
combinatorial optimization, which can be formulated as the maximization of a
quadratic square-free polynomial over the (Boolean) hypercube. We investigate a
hierarchy of linear programming relaxations for this problem, based on a result
of Handelman showing that a positive polynomial over a polytope with non-empty
interior can be represented as conic combination of products of the linear
constraints defining the polytope. We relate the rank of Handelman's hierarchy
with structural properties of graphs. In particular we show a relation to
fractional clique covers which we use to upper bound the Handelman rank for
perfect graphs and determine its exact value in the vertex-transitive case.
Moreover we show two upper bounds on the Handelman rank in terms of the
(fractional) stability number of the graph and compute the Handelman rank for
several classes of graphs including odd cycles and wheels and their
complements. We also point out links to several other linear and semidefinite
programming hierarchies.


title:
Coupling, merging, and splitting Dirac points by electron-electron
  interaction

abstract:
  The manipulation and movement of Dirac points in the Brillouin zone by the
electron-electron interaction is considered within leading order perturbation
theory. At the merging point, an infinitesimal interaction is shown to cause
opening of the gap or splitting of the Dirac points, depending on the inter- or
intrasublattice nature of the merging and the sign of the interaction. The
topology of the spectrum can therefore be efficiently changed by simply tuning
the interaction between particles, as opposed to the usual careful band
structure engineering. This is illustrated around the merging transition of
one, two, and three dimensional Dirac-Weyl fermions. A simple Weyl-like
Hamiltonian that describes the quadratic band-crossing in three dimensions is
also proposed, and its stability under interactions is addressed.


title:
Ramsey spectroscopy of high-contrast CPT resonances with push-pull
  optical pumping in Cs vapor

abstract:
  We report the detection of high-contrast and narrow Coherent Population
Trapping (CPT) Ramsey fringes in a Cs vapor cell using a simple-architecture
laser system. The latter allows the combination of push-pull optical pumping
(PPOP) and a temporal Ramsey-like pulsed interrogation. An originality of the
optics package is the use of a single Mach-Zehnder electro-optic modulator (MZ
EOM) both for optical sidebands generation and light switch for pulsed
interaction. Typical Ramsey fringes with a linewidth of 166 Hz and a contrast
of 33 % are detected in a cm-scale buffer-gas filled Cs vapor cell. This
technique could be interesting for the development of high-performance and low
power consumption compact vapor cell clocks based on CPT.


title:
Quantum phase space functions and relations of entropic localisation
  measures

abstract:
  The concept of quantum phase space offers a view on quantum mechanics, which
is different from the standard Hilbert space approach, but which more closely
resembles the classical phase space. Due to the properties of quantum mechanics
there are several equivalent quantum phase space descriptions, and one cannot
always prefer one or another as they all have certain merits and drawbacks. For
example, the Husimi-Kano Q function is a probability distribution and thus
gives rise to entropic quantities, namely the Renyi-Wehrl entropies, of which
several properties are known. The Wigner function, on the other hand, has an
easier physical explanation, but may take negative values. In this article, we
investigate entropic measures of localisation for a state in quantum phase
space by using the Beckner-Brascamp-Lieb inequality to relate different
phase-space functions.


title:
Sub-Stream Fairness and Numerical Correctness in MIMO Interference
  Channels

abstract:
  Signal-to-interference plus noise ratio (SINR) and rate fairness in a system
are substantial quality-of-service (QoS) metrics. The acclaimed SINR
maximization (max-SINR) algorithm does not achieve fairness between user's
streams, i.e., sub-stream fairness is not achieved. To this end, we propose a
distributed power control algorithm to render sub-stream fairness in the
system. Sub-stream fairness is a less restrictive design metric than stream
fairness (i.e., fairness between all streams) thus sum-rate degradation is
milder. Algorithmic parameters can significantly differentiate the results of
numerical algorithms. A complete picture for comparison of algorithms can only
be depicted by varying these parameters. For example, a predetermined iteration
number or a negligible increment in the sum-rate can be the stopping criteria
of an algorithm. While the distributed interference alignment (DIA) can
reasonably achieve sub-stream fairness for the later, the imbalance between
sub-streams increases as the preset iteration number decreases. Thus comparison
of max-SINR and DIA with a low preset iteration number can only depict a part
of the picture. We analyze such important parameters and their effects on SINR
and rate metrics to exhibit numerical correctness in executing the benchmarks.
Finally, we propose group filtering schemes that jointly design the streams of
a user in contrast to max-SINR scheme that designs each stream of a user
separately.


title:
Relevance of electron spin dissipative processes to dynamic nuclear
  polarization via thermal mixing

abstract:
  The available theoretical approaches aiming at describing Dynamic Nuclear
spin Polarization (DNP) in solutions containing molecules of biomedical
interest and paramagnetic centers are not able to model the behaviour observed
upon varying the concentration of trityl radicals or the polarization
enhancement caused by moderate addition of gadolinium complexes. In this
manuscript, we first show experimentally that the nuclear steady state
polarization reached in solutions of pyruvic acid with 15 mM trityl radicals is
substantially independent from the average internuclear distance. This
evidences a leading role of electron (over nuclear) spin relaxation processes
in determining the ultimate performances of DNP. Accordingly, we have devised a
variant of the Thermal Mixing model for inhomogenously broadened electron
resonance lines which includes a relaxation term describing the exchange of
magnetic anisotropy energy of the electron spin system with the lattice. Thanks
to this additional term, the dependence of the nuclear polarization on the
electron concentration can be properly accounted for. Moreover, the model
predicts a strong increase of the final polarization on shortening the electron
spin-lattice relaxation time, providing a possible explanation for the effect
of gadolinium doping.


title:
How Levins' dynamics emerges from a Ricker metapopulation model on the
  brink of extinction

abstract:
  Understanding the dynamics of metapopulations close to extinction is of vital
importance for management. Levins-like models, in which local patches are
treated as either occupied or empty, have been used extensively for this
purpose, but they ignore the important role of local population dynamics. In
this paper, we consider a stochastic metapopulation model where local
populations follow a Ricker dynamics, and use this framework to investigate the
behaviour of the metapopulation at the brink of extinction. As long as
dispersal rates are not too large, the system is shown to have a time evolution
consistent with Levins' dynamics. We derive analytical expressions for the
colonisation and extinction rates (c and e) in Levins-type models in terms of
reproduction, survival, and dispersal parameters of the local populations,
providing an avenue to parameterising Levins-like models from the type of
information on local demography that is available for a number of species. To
facilitate applying our results, we provide a numerical implementation for
computing c and e.


title: A magnetic reconnection origin for the soft X-ray excess in AGN

abstract:
  We present a new scenario to explain the soft X-ray excess in Active Galactic
Nucleus. The magnetic reconnection could happen in a thin layer on the surface
of accretion disk. Electrons are accelerated by shock wave and turbulence
triggered by magnetic reconnection, then they take place inverse Compton
scattering above accretion disk which contributes soft X-rays. Based on
standard disk model, we estimate the magnetic field strength and the energy
released by magnetic reconnection along accretion disk, and find that the
luminosity caused by magnetic reconnection mainly emits in the inner disk which
is dominated by radiation pressure. We then apply the model to fit the spectra
of AGNs with strong soft X-ray excess.


title:
Moments of net-charge multiplicity distribution in Au+Au collisions
  measured by the PHENIX experiment at RHIC

abstract:
  Beam Energy Scan (BES) program at RHIC is important to search for the
existence of the critical point in the QCD phase diagram. Lattice QCD have
shown that the predictions of the susceptibility of the medium formed in
heavy-ion collisions can be sensitive to the various moments (mean ($\mu$)
=${<x>}$, variance ($\sigma^2$) = ${<(x-\mu)^2>}$, skewness (S) =
$\frac{<(x-\mu)^3>}{\sigma^3}$ and kurtosis ($\kappa$)
=$\frac{<(x-\mu)^4>}{\sigma^4} -3$) of conserved quantities like net-baryon
number ($\Delta$B), net-electric charge ($\Delta$Q) and net-strangeness
($\Delta$S).
  Any non-monotonic behavior of the higher moments would confirm the existence
of the QCD critical point. The recent results of the higher moments of
net-charge multiplicity distributions for Au+Au collisions at $\sqrt{s}_{NN}$
varying from 7.7 GeV to 200 GeV from the PHENIX experiment at RHIC are
presented. The energy and centrality dependence of the higher moments and their
products (S$\sigma$ and $\kappa\sigma^{2}$) are shown for the net-charge
multiplicity distributions. Furthermore, the results are compared with the
values obtained from the heavy-ion collision models, where there is no QCD
phase transition and critical point.


title: Off-diagonal Bethe ansatz and exact solution of a topological spin ring

abstract:
  A general method is proposed for constructing the Bethe ansatz equations of
integrable models without U(1) symmetry. As an example, the exact spectrum of
the XXZ spin ring with M{\" o}bius like topological boundary condition is
derived by constructing a modified T-Q relation based on the functional
connection between the eigenvalues of the transfer matrix and the quantum
determinant of the monodromy matrix. With the exact solution, the elementary
excitations of the topological XX spin ring is discussed in detail. It is found
that the excitation spectrum indeed shows a nontrivial topological nature.

categories: cond-mat.stat-mech hep-th math-ph math.MP


title: On generalized Volterra systems

abstract:
  We construct a large family of evidently integrable Hamiltonian systems which
are generalizations of the KM system. The Hamiltonian vector field is
homogeneous cubic but in a number of cases a simple change of variables
transforms such a system to a quadratic Lotka-Volterra system. We present in
detail all such systems in dimensions 4 and 5 and we also give some examples
from higher dimensions. This construction generalizes easily to each complex
simple Lie algebra.


title:
Highly inclined and eccentric massive planets I: Planet-disc
  interactions

abstract:
  In the Solar System, planets have a small inclination with respect to the
equatorial plane of the Sun, but there is evidence that in extrasolar systems
the inclination can be very high. This spin-orbit misalignment is unexpected,
as planets form in a protoplanetary disc supposedly aligned with the stellar
spin. Planet-planet interactions are supposed to lead to a mutual inclination,
but the effects of the protoplanetary disc are still unknown. We investigate
therefore planet-disc interactions for planets above 1M_Jup. We check the
influence of the inclination i, eccentricity e, and mass M_p of the planet. We
perform 3D numerical simulations of protoplanetary discs with embedded
high-mass planets. We provide damping formulae for i and e as a function of i,
e, and M_p that fit the numerical data. For highly inclined massive planets,
the gap opening is reduced, and the damping of i occurs on time-scales of the
order of 10^-4 deg/yr M_disc/(0.01 M_star) with the damping of e on a smaller
time-scale. While the inclination of low planetary masses (<5M_Jup) is always
damped, large planetary masses with large i can undergo a Kozai-cycle with the
disc. These Kozai-cycles are damped in time. Eccentricity is generally damped,
except for very massive planets (M_p = 5M_Jup) where eccentricity can increase
for low inclinations. The dynamics tends to a final state: planets end up in
midplane and can then, over time, increase their eccentricity as a result of
interactions with the disc. The interactions with the disc lead to damping of i
and e after a scattering event of high-mass planets. If i is sufficiently
reduced, the eccentricity can be pumped up because of interactions with the
disc. If the planet is scattered to high inclination, it can undergo a
Kozai-cycle with the disc that makes it hard to predict the exact movement of
the planet and its orbital parameters at the dispersal of the disc.


title: Alternating Decision trees for early diagnosis of dengue fever

abstract:
  Dengue fever is a flu-like illness spread by the bite of an infected mosquito
which is fast emerging as a major health problem. Timely and cost effective
diagnosis using clinical and laboratory features would reduce the mortality
rates besides providing better grounds for clinical management and disease
surveillance. We wish to develop a robust and effective decision tree based
approach for predicting dengue disease. Our analysis is based on the clinical
characteristics and laboratory measurements of the diseased individuals. We
have developed and trained an alternating decision tree with boosting and
compared its performance with C4.5 algorithm for dengue disease diagnosis. Of
the 65 patient records a diagnosis establishes that 53 individuals have been
confirmed to have dengue fever. An alternating decision tree based algorithm
was able to differentiate the dengue fever using the clinical and laboratory
data with number of correctly classified instances as 89%, F-measure of 0.86
and receiver operator characteristics (ROC) of 0.826 as compared to C4.5 having
correctly classified instances as 78%,h F-measure of 0.738 and ROC of 0.617
respectively. Alternating decision tree based approach with boosting has been
able to predict dengue fever with a higher degree of accuracy than C4.5 based
decision tree using simple clinical and laboratory features. Further analysis
on larger data sets is required to improve the sensitivity and specificity of
the alternating decision trees.


title: Compositional Verification and Optimization of Interactive Markov Chains

abstract:
  Interactive Markov chains (IMC) are compositional behavioural models
extending labelled transition systems and continuous-time Markov chains. We
provide a framework and algorithms for compositional verification and
optimization of IMC with respect to time-bounded properties. Firstly, we give a
specification formalism for IMC. Secondly, given a time-bounded property, an
IMC component and the assumption that its unknown environment satisfies a given
specification, we synthesize a scheduler for the component optimizing the
probability that the property is satisfied in any such environment.


title: Revisiting the matter power spectra in $f(R)$ gravity

abstract:
  In this paper, we study the non-linear matter power spectrum in a specific
family of $f(R)$ models that can reproduce the $\Lambda$CDM background
expansion history, using high resolution $N$-body simulations based on the {\sc
ecosmog} code. We measure the matter power spectrum in the range of $0.05h{\rm
Mpc}^{-1}<k<10h{\rm Mpc}^{-1}$ from simulations for our $f(R)$ models and give
theoretical explanations to their behaviour and evolution patterns. We also
examine the chameleon mechanism for our models and find that it works
throughout the cosmic history in dense regions, for our $f(R)$ models with
$|f_{R0}|<10^{-4}$. On the other hand, for models with $|f_{R0}|>10^{-3}$, we
find no chameleon screening in dense regions at late times ($z<3$), which means
that those models could be ruled out due to the factor-of-$1/3$ enhancement to
the strength of Newtonian gravity. We also give the best-fit parameters for a
generalised PPF fitting formula which works well for the models studied here.


title:
Three dimensional confinement of vapor in nanostructures for sub-Doppler
  optical resolution

abstract:
  We confine a Cs thermal vapor in the interstitial regions of a glass opal. We
perform linear reflection spectroscopy on a cell whose window is covered with a
thin film (10 or 20 layers) of ~ 1000 nm (or 400 nm) diameter glass spheres, we
observe sub-Doppler structures in the optical spectrum for a large range of
oblique incidences. This original feature associated with the inner
(3-dimension) confinement of the vapor in the interstitial regions of the opal,
evokes a Dicke narrowing. We finally consider possible micron-size references
for optical frequency clocks based on weak, hard to saturate, molecular lines.


title:
Effect of Thermal Annealing on Boron Diffusion, Micro-structural,
  Electrical and Magnetic properties of Laser Ablated CoFeB Thin Films

abstract:
  We report on Boron diffusion and subsequent crystallization of
Co$_{40}$Fe$_{40}$B$_{20}$ (CoFeB) thin films on SiO$_2$/Si(001) substrate
using pulsed laser deposition. Secondary ion mass spectroscopy reveals Boron
diffusion at the interface in both amorphous and crystalline phase of CoFeB.
High-resolution transmission electron microscopy reveals a small fraction of
nano-crystallites embedded in the amorphous matrix of CoFeB. However, annealing
at 400$^\circ$C results in crystallization of CoFe with \textit{bcc} structure
along (110) orientation. As-deposited films are non-metallic in nature with the
coercivity (H$_c$) of 5Oe while the films annealed at 400$^\circ$C are metallic
with a H$_c$ of 135Oe.


title:
Apparatus for Measurement of the Electric Dipole Moment of the Neutron
  using a Cohabiting Atomic-Mercury Magnetometer

abstract:
  A description is presented of apparatus used to carry out an experimental
search for an electric dipole moment of the neutron, at the Institut
Laue-Langevin (ILL), Grenoble. The experiment incorporated a cohabiting
atomic-mercury magnetometer in order to reduce spurious signals from magnetic
field fluctuations. The result has been published in an earlier letter; here,
the methods and equipment used are discussed in detail.


title: Resources of polarimetric sensitivity in spin noise spectroscopy

abstract:
  We attract attention to the fact that the ultimate (shot-noise-limited)
polarimetric sensitivity can be enhanced by orders of magnitude leaving the
photon flux incident onto the photodetector on the same low level. This
opportunity is of crucial importance for present-day spin noise spectroscopy,
where a direct increase of sensitivity by increasing the probe beam power is
strongly restricted by the admissible input power of the broadband
photodetectors. The gain in sensitivity is achieved by replacing the 45-deg
polarization geometry commonly used in conventional schemes with balanced
detectors by geometries with stronger polarization extinction. The efficiency
of these high-extinction polarization geometries with enhancement of the
detected signal by more than an order of magnitude is demonstrated by
measurements of the spin noise spectra of bulk n:GaAs in the spectral range
835-918 nm. It is shown that the inevitable growth of the probe beam power with
the sensitivity gain makes spin noise spectroscopy much more perturbative, but,
at the same time, opens up fresh opportunities for studying nonlinear
interactions of strong light fields with spin ensembles.


title: The electric dipole response of $^{76}$Se above 4 MeV

abstract:
  The dipole response of $^{76}_{34}$Se in the energy range 4 to 9 MeV has been
analyzed using a $(\vec\gamma,{\gamma}')$ polarized photon scattering
technique, performed at the High Intensity $\gamma$-Ray Source facility, to
complement previous work performed using unpolarized photons. The results of
this work offer both an enhanced sensitivity scan of the dipole response and an
unambiguous determination of the parities of the observed J=1 states. The
dipole response is found to be dominated by $E1$ excitations, and can
reasonably be attributed to a pygmy dipole resonance. Evidence is presented to
suggest that a significant amount of directly unobserved excitation strength is
present in the region, due to unobserved branching transitions in the decays of
resonantly excited states. The dipole response of the region is underestimated
when considering only ground state decay branches. We investigate the electric
dipole response theoretically, performing calculations in a 3D cartesian-basis
time-dependent Skyrme-Hartree-Fock framework.


title: On the max-algebraic core of a nonnegative matrix

abstract:
  The max-algebraic core of a nonnegative matrix is the intersection of column
spans of all max-algebraic matrix powers. Here we investigate the action of a
matrix on its core. Being closely related to ultimate periodicity of matrix
powers, this study leads us to new modifications and geometric
characterizations of robust, orbit periodic and weakly stable matrices.


title: On the Higgs boson pair production at the LHC

abstract:
  We compute the production cross section of a pair of Standard Model Higgs
bosons at the LHC at next-to-leading order in QCD, including corrections in
inverse powers of the top quark mass. We calculate these power corrections
through ${\cal O}(1/M_t^8)$ and study their relevance for phenomenology of the
double Higgs production. We find that power corrections are significant, even
for moderate values of partonic center-of-mass energies, and that convergence
of the $1/M_t$ expansion can be dramatically improved by factorizing the
leading order cross section with full $M_t$-dependence.


title: Light transmission through a triangular air gap

abstract:
  Due to the recent interest in studying propagation of light through
triangular air gaps, we calculate, by using the analogy between optics and
quantum mechanics and the multiple step technique, the transmissivity through a
triangular air gap surrounded by an homogeneous dielectric medium. The new
formula is then compared with the formula used in literature. Starting from the
qualitative and quantitative differences between these formulas, we propose
optical experiments to test our theoretical results.


title:
Effective Valence Quark Model and a Possible Dip in $d Br(B \to K \ell
  \bar{\ell})/dq^2$

abstract:
  In rare $B$ meson decays $B\rightarrow K \ell^+ \ell^-$, a possible
contribution of $\ell^+\ell^-$ emission via photon from the "spectator" quark
$q$ ($q=u,d$) in the $B$ meson $(q\bar{b})$ is investigated in addition to the
conventional one $\bar{b} \rightarrow \bar{s} +\gamma \rightarrow
\bar{s}+\ell^+ + \ell^-$. If such a contribution is sizable compared with the
standard estimation of $B\rightarrow K \ell^+ \ell^-$, we will observe visible
difference between $d \Gamma(B^0\rightarrow K^0 \ell^+ \ell^-)/d q^2$ and $d
\Gamma(B^+\rightarrow K^+ \ell^+ \ell^-)/d q^2$ in $q^2$ dependence ($q^2
\equiv m_{\ell\ell}^2$). Besides, as a result of the interference between the
conventional one and a new one, a dip appears in $d \Gamma(B\rightarrow K
\ell^+ \ell^-)/d q^2$ at a small region of $q^2$. The interference effect in
the $B^0$ decay will also be observed differently from that in the $B^+$ decay.
The calculation is done based on a semi-classical approach, a valence quark
model. In the present model, the photon emission from the spectator quark $q$,
$d \rightarrow d+\gamma$ ($u \rightarrow u+\gamma$) is independent of the
$b$-$s$ transition mechanism, and the characteristic results are due to a
straightforward estimate of the quark propagator which cannot be incorporated
into the factorization method. The model is not a valence quark "dominant"
model, so that, for example, the valence quarks in the final state carry only
$24\%$ of the energy-momentum of the kaon.


title: CP violation in D meson decays: would it be a sign of new physics ?

abstract:
  Ascribing the large SU(3) violations in the Cabibbo forbidden decays of
neutral D mesons to the final state interactions, one gets large strong phase
differences, necessary for substantial direct CP violation. While the absolute
value of the CP violating asymmetries depend on the uncertain strength of the
penguin contribution, we predict an asymmetry for the decays into charged pions
more than twice as large and having opposite sign with respect to that for
charged kaons.


title:
Joint Modeling and Registration of Cell Populations in Cohorts of
  High-Dimensional Flow Cytometric Data

abstract:
  In systems biomedicine, an experimenter encounters different potential
sources of variation in data such as individual samples, multiple experimental
conditions, and multi-variable network-level responses. In multiparametric
cytometry, which is often used for analyzing patient samples, such issues are
critical. While computational methods can identify cell populations in
individual samples, without the ability to automatically match them across
samples, it is difficult to compare and characterize the populations in typical
experiments, such as those responding to various stimulations or distinctive of
particular patients or time-points, especially when there are many samples.
Joint Clustering and Matching (JCM) is a multi-level framework for simultaneous
modeling and registration of populations across a cohort. JCM models every
population with a robust multivariate probability distribution. Simultaneously,
JCM fits a random-effects model to construct an overall batch template -- used
for registering populations across samples, and classifying new samples. By
tackling systems-level variation, JCM supports practical biomedical
applications involving large cohorts.


title: Algebraic Properties of Qualitative Spatio-Temporal Calculi

abstract:
  Qualitative spatial and temporal reasoning is based on so-called qualitative
calculi. Algebraic properties of these calculi have several implications on
reasoning algorithms. But what exactly is a qualitative calculus? And to which
extent do the qualitative calculi proposed meet these demands? The literature
provides various answers to the first question but only few facts about the
second. In this paper we identify the minimal requirements to binary
spatio-temporal calculi and we discuss the relevance of the according axioms
for representation and reasoning. We also analyze existing qualitative calculi
and provide a classification involving different notions of a relation algebra.


title: Ferromagnetic Phase Transitions in Neutron Stars

abstract:
  The ferromagnetic phase in pure neutron matter as well as charge neutral,
beta-equilibrated nuclear matter is considered. We employ Quantum
Hadrodynamics, a relativistic field theory description of nuclear matter with
meson degrees of freedom, and include couplings between the baryon (proton and
neutron) magnetic dipole moment as well as between their charge and the
magnetic field in the Lagrangian density describing such a system. We vary the
strength of the baryon magnetic dipole moment till a non-zero value of the
magnetic field, for which the total energy density of the magnetised system is
at a minimum, is found. The system is then assumed to be in the ferromagnetic
state.
  The ferromagnetic equation of state is employed to study matter in the
neutron star interior. We find that as the density increases the ferromagnetic
field does not increase continuously, but exhibit sudden rapid increases. These
sudden increases in the magnetic field correspond to shifts between different
configurations of the charged particle's Landau levels and can have significant
observational consequences for neutron stars. We also found that although the
ferromagnetic phase softens the neutron star equation of state it does not
significantly alter the star's mass-radius relationship.
  The properties of magnetised symmetric nuclear matter were also studied. We
confirm that magnetised matter tends to be more proton-rich but become more
weakly bound for stronger magnetic fields. We show that the behaviour of the
compressibility of nuclear matter is influenced by the Landau quantisation and
tends to have an oscillatory character as it increases with the magnetic field.
The symmetry energy also exhibits similar behaviour.


title:
Isotropization of solutions of the Einstein-Vlasov system with Bianchi V
  symmetry

abstract:
  Using the methods developed for different Bianchi class A cosmological models
we treat the simplest Bianchi class B model, namely Bianchi type V. The future
non-linear stability for solutions of the Einstein-Vlasov system is
demonstrated and it is shown that these solutions are asymptotically stable to
the Milne solution. Within the isotropic solutions of the Einstein-Vlasov
system the spatially flat Friedmann solution is unstable within this class, and
expanding models tend also to the Milne solution.


title:
An analytic approach to infinite-dimensional continuity and
  Fokker-Planck-Kolmogorov equations

abstract:
  We prove a new uniqueness result for solutions to Fokker-Planck-Kolmogorov
(FPK) equations for probability measures on infinite-dimensional spaces. We
consider infinite-dimensional drifts that admit certain finite-dimensional
approximations. In contrast to most of the previous work on FPK-equations in
infinite dimensions, we include cases with non-constant coefficients in the
second order part and also include degenerate cases where these coefficients
can even be zero. Also a new existence result is proved. Some applications to
Fokker-Planck-Kolmogorov equations associated with SPDEs are presented.


title:
Pointwise regularity of the free boundary for the parabolic obstacle
  problem

abstract:
  We study the parabolic obstacle problem $$\lap u-u_t=f\chi_{\{u>0\}}, \quad
u\geq 0,\quad f\in L^p \quad \mbox{with}\quad f(0)=1$$ and obtain two
monotonicity formulae, one that applies for general free boundary points and
one for singular free boundary points. These are used to prove a second order
Taylor expansion at singular points (under a pointwise Dini condition), with an
estimate of the error (under a pointwise double Dini condition). Moreover,
under the assumption that $f$ is Dini continuous, we prove that the set of
regular points is locally a (parabolic) $C^1$-surface and that the set of
singular points is locally contained in a union of (parabolic) $C^1$ manifolds.


title: On multipliers for Hardy-Sobolev spaces and holomorphic potentials

abstract:
  We study the action of some generalized integral operators of Bergman type on
pointwise multipliers of holomorphic Triebel-Lizorkin spaces. We construct
nontrivial examples of pointwise multipliers in Hardy-Sobolev spaces and give
applications of all these results.


title: Local and Global Analysis of Parametric Solid Sweeps

abstract:
  In this work, we propose a detailed computational framework for modelling the
envelope of the swept volume, that is the boundary of the volume obtained by
sweeping an input solid along a trajectory of rigid motions. Our framework is
adapted to the well-established industry-standard brep format to enable its
implementation in modern CAD systems. This is achieved via a "local analysis",
which covers parametrization and singularities, as well as a "global theory"
which tackles face-boundaries, self-intersections and trim curves. Central to
the local analysis is the "funnel" which serves as a natural parameter space
for the basic surfaces constituting the sweep. The trimming problem is reduced
to the problem of surface-surface intersections of these basic surfaces. Based
on the complexity of these intersections, we introduce a novel classification
of sweeps as either decomposable or non-decomposable. Further, we construct an
{\em invariant} function $\theta$ on the funnel which efficiently separates
decomposable and non-decomposable sweeps. Through a geometric theorem we also
show intimate connections between $\theta$, local curvatures and the inverse
trajectory used in earlier works as an approach towards trimming. In contrast
to the inverse trajectory approach, $\theta$ is robust and is the key to a
complete structural understanding, and an efficient computation of both, the
singular locus and the trim curves, which are central to a stable
implementation. Several illustrative outputs of a pilot implementation are
included.


title: Bilinear forms on weighted Besov spaces

abstract:
  We compute the norm of some bilinear forms on products of weighted Besov
spaces in terms of the norm of their symbol in a space of pointwise multipliers
defined in terms of Carleson measures.


title:
The quenching of star formation in accretion-driven clumpy turbulent
  tori of active galactic nuclei

abstract:
  Galactic gas-gas collisions involving a turbulent multiphase ISM share common
ISM properties: dense extraplanar gas visible in CO, large linewidths (>= 50
km/s), strong mid-infrared H_2 line emission, low star formation activity, and
strong radio continuum emission. Gas-gas collisions can occur in the form of
ICM ram pressure stripping, galaxy head-on collisions, compression of the
intragroup gas and/or galaxy ISM by an intruder galaxy which flies through the
galaxy group at a high velocity, or external gas accretion on an existing gas
torus in a galactic center. We suggest that the common theme of all these
gas-gas interactions is adiabatic compression of the ISM leading to an increase
of the turbulent velocity dispersion of the gas. The turbulent gas clouds are
then overpressured and star formation is quenched. Within this scenario we
developed a model for turbulent clumpy gas disks where the energy to drive
turbulence is supplied by external infall or the gain of potential energy by
radial gas accretion within the disk. The cloud size is determined by the size
of a C-type shock propagating in dense molecular clouds with a low ionization
fraction at a given velocity dispersion. We give expressions for the expected
volume and area filling factors, mass, density, column density, and velocity
dispersion of the clouds. The latter is based on scaling relations of
intermittent turbulence whose open parameters are estimated for the CND in the
Galactic Center. The properties of the model gas clouds and the external mass
accretion rate necessary for the quenching of the star formation rate due to
adiabatic compression are consistent with those derived from high-resolution
H_2 line observations. Based on these findings, a scenario for the evolution of
gas tori in galactic centers is proposed and the implications for star
formation in the Galactic Center are discussed.


title: Effects of fermionic dark matter on properties of neutron stars

abstract:
  By assuming that only gravitation exists between dark matter (DM) and normal
matter (NM), we study the effects of fermionic DM on the properties of neutron
stars using the two-fluid Tolman-Oppenheimer-Volkoff formalism. It is found
that the mass-radius relationship of the DM admixed neutron stars (DANSs)
depends sensitively on the mass of DM candidates, the amount of DM, and
interactions among DM candidates. The existence of DM in DANSs results in a
spread of mass-radius relationships that cannot be interpreted with a unique
equilibrium sequence. In some cases, the DM distribution can surpass the NM
distribution to form DM halo. In particular, it is favorable to form an
explicit DM halo, provided the repulsion of DM exists. It is interesting to
find that the difference in particle number density distributions in DANSs and
consequently in star radii caused by various density dependencies of nuclear
symmetry energy tends to disappear as long as the repulsion of accumulated DM
is sufficient. These phenomena indicate that the admixture of DM in neutron
stars can significantly affect the astrophysical extraction of nuclear equation
of state by virtue of neutron star measurements. In addition, the effect of the
DM admixture on the star maximum mass is also investigated.


title: Shells of crystal field symmetries evidenced in oxide nano-crystals

abstract:
  By the use of a point charge model based on the Judd-Ofelt transition theory,
the luminescence from Eu3+ ions embedded in Gd2O3 clusters is calculated and
compared to the experimental data. The main result of the numerical study is
that without invoking any other mechanisms such as crystal disorder, the pure
geometrical argument of the symmetry breaking induced by the particle surface
has influence on the energy level splitting. The modifications are also
predicted to be observable in realistic conditions where unavoidable size
dispersion has to be taken into account. The emission spectrum results from the
contribution of three distinct regions, a cluster core, a cluster shell and a
very surface, the latter being almost completely quenched in realistic
conditions. Eventually, by detailing the spectra of the ions embedded at
different positions in the cluster we get an estimate of about 0.5 nm for the
extent of the crystal field induced Stark effect. Due to the similarity between
Y2O3 and Gd2O3, these results apply also to Eu3+ doped Y2O3 nanoparticles.


title: 2-photon decay rate of the scalar boson in the Inert Doublet Model

abstract:
  Motivated by experimental hints on the possibility of deviating from the SM
predictions for the 2-photon decay rate of the 125 GeV SM-like scalar boson h,
an analysis of this rate in the framework of the Inert Doublet Model is
presented. Regions in the parameter space where the 2-photon decay rate is
enhanced were found. The resulting regions are confronted with the allowed
values of the Dark Matter (DM) particle's mass. Constraints on the masses of
the charged scalar and the DM particle, and scalar couplings are presented.


title: Lepton Flavor Violations in High-Scale SUSY with Right-Handed Neutrinos

abstract:
  Motivated by the recent discovery of the Higgs boson at m_h = 126 GeV and
also by the non-observation of superparticles at the LHC, high-scale SUSY,
where the superparticles are as heavy as O(10) TeV, has been recently proposed.
We study lepton-flavor violations (LFVs) in the high-scale SUSY with
right-handed neutrinos. Even if the slepton masses are of O(10) TeV, the
renormalization group (RG) effects on the slepton mass-squared matrix may
induce large enough LFVs which are within the reach of future LFV experiments.
We also discuss the implication of the right-handed neutrinos on the
electroweak symmetry breaking in such a model, and show that the parameter
region with the successful electroweak symmetry breaking is enlarged by the RG
effects due to the right-handed neutrinos.


title:
Exact Solutions for an MHD Generalized Burgers fluid: Stokes' Second
  Problem

abstract:
  This paper offers the exact analytical solutions for the magnetohydrodynamic
(MHD) flow of an incompressible generalized Burgers fluid corresponding to the
second problem of Stokes in the presence of the transverse magnetic field.
Modified Darcy's law has been taken into account. The expression for the
velocity field and associated tangential stress, presented as a sum of the
steady-state and transient solutions, are obtained by means of the integral
transforms. Moreover, several figures are plotted to investigate the effects of
various emerging parameters on the velocity field. The obtained results show
that the magnitude of the velocity and boundary layer thickness significantly
reduce in the presence of magnetic field.


title: A Kac CROW Delay Line

abstract:
  A low-loss CROW delay line with a weak inter-resonator coupling determined by
the Kac matrix is dispersionless and can be easily impedance-matched by
adjusting the coupling to the input/output waveguide.


title:
Pervasive Parallelism in Highly-Trustable Interactive Theorem Proving
  Systems

abstract:
  This is an overview of the Paral-ITP project, which intents to make the proof
assistants Isabelle and Coq fit for the multicore era.


title: Differential forms in the h-topology

abstract:
  We study sheaves of differential forms and their cohomology in the
h-topology. This allows to extend standard results from the case of smooth
varieties to the general case. As a first application we explain the case of
singularities arising in the Minimal Model Program. As a second application we
consider de Rham cohomology.


title:
Mimicking the nonlinear dynamics of optical fibers with waveguide
  arrays: towards a spatiotemporal supercontinuum generation

abstract:
  We numerically demonstrate the formation of the spatiotemporal version of the
so-called diffractive resonant radiation generated in waveguide arrays with
Kerr nonlinearity when a long pulse is launched into the system. The phase
matching condition for the diffractive resonant radiation that we have found
earlier for CW beams also works well in the spatiotemporal case. By introducing
a linear potential, one can introduce a continuous shift of the central
wavenumber of a linear pulse, whereas in the nonlinear case one can demonstrate
that the soliton self-wavenumber shift can be compensated by the emission of
diffractive resonant radiation, in a very similar fashion as it is done in
optical fibers. This work paves the way for designing unique optical devices
that generate spectrally broad supercontinua with a controllable directionality
by taking advantage of the combined physics of optical fibers and waveguide
arrays.


title: Recursive Green's function method for multi-terminal nanostructures

abstract:
  We present and review an efficient method to calculate the retarded Green's
function in multi-terminal nanostructures; which is needed in order to
calculate the conductance through the system and the local particle densities
within it. The method uses the recursive Green's function method after the
discretized Hamilton matrix has been properly partitioned. We show that this
method, the circular slicing scheme, can be modified to accommodate
multi-terminal systems as well as the traditional two-terminal systems.
Furthermore, we show that the performance and robustness of the circular
slicing scheme is on par with other advanced methods and is well suited for
large variety of multi-terminal geometries. We end by giving an example of how
the method can be used to calculate transport in a non-trivial multi-terminal
geometry.


title:
Modeling the modulation of neuronal bursting: a singularity theory
  approach

abstract:
  Exploiting the specific structure of neuron conductance-based models, the
paper investigates the mathematical modeling of neuronal bursting modulation.
The proposed approach combines singularity theory and geometric singular
perturbations to capture the geometry of multiple time-scales attractors in the
neighborhood of high-codimension singularities. We detect a three-time scale
bursting attractor in the universal unfolding of the winged cusp singularity
and discuss the physiological relevance of the bifurcation and unfolding
parameters in determining a physiological modulation of bursting. The results
suggest generality and simplicity in the organizing role of the winged cusp
singularity for the global dynamics of conductance based models.


title: Molecular cooling in the diffuse interstellar medium

abstract:
  We use a simple one-zone model of the thermal and chemical evolution of
interstellar gas to study whether molecular hydrogen (H2) is ever an important
coolant of the warm, diffuse interstellar medium (ISM). We demonstrate that at
solar metallicity, H2 cooling is unimportant and the thermal evolution of the
ISM is dominated by metal line cooling. At metallicities below 0.1 Z_solar,
however, metal line cooling of low density gas quickly becomes unimportant and
H2 can become the dominant coolant, even though its abundance in the gas
remains small. We investigate the conditions required in order for H2 to
dominate, and show that it provides significant cooling only when the ratio of
the interstellar radiation field strength to the gas density is small. Finally,
we demonstrate that our results are insensitive to changes in the initial
fractional ionization of the gas or to uncertainties in the nature of the dust
present in the low-metallicity ISM.


title:
Understanding the dynamical structure of pulsating stars: The
  center-of-mass velocity and the Baade-Wesselink projection factor of the
  beta-Cephei star alpha-Lupi

abstract:
  High-resolution spectroscopy of pulsating stars is a powerful tool to study
the dynamical structure of their atmosphere. Lines asymmetry is used to derive
the center-of-mass velocity of the star, while a direct measurement of the
atmospheric velocity gradient helps determine the projection factor used in the
Baade-Wesselink method of distance determination. We aim at deriving the
center-of-mass velocity and the projection factor of the beta-Cephei star
alpha-Lup. We present HARPS high spectral resolution observations of alpha-Lup.
We calculate the first-moment radial velocities and fit the spectral line
profiles by a bi-Gaussian to derive line asymmetries. Correlations between the
gamma-velocity and the gamma-asymmetry (defined as the average values of the
radial velocity and line asymmetry curves respectively) are used to derive the
center-of-mass velocity of the star. By combining our spectroscopic
determination of the atmospheric velocity gradient with a hydrodynamical
modelof the photosphere of the star, we derive a semi-theoretical projection
factor for alpha Lup. We find a center-of-mass velocity of Vgamma = 7.9 +/- 0.6
km/s and that the velocity gradient in the atmosphere of alpha Lup isnull. We
apply to alpha Lup the usual decomposition of the projection factor into three
parts, p = p0 fgrad fog (originally developed for Cepheids), and derive a
projection factor of p = 1.43 +/-0.01. By comparing our results with previous
HARPS observations of classical Cepheids, we also point out a linear relation
between the atmospheric velocity gradient and the amplitude of the radial
velocity curve. Moreover, we observe a phase shift (Van Hoof effect), whereas
alpha Lup has no velocity gradient.


title:
Diffusion imaging with stimulated echoes: signal models and experiment
  design

abstract:
  Purpose: Stimulated echo acquisition mode (STEAM) diffusion MRI can be
advantageous over pulsed-gradient spin-echo (PGSE) for diffusion times that are
long compared to $\ttwo$. It is important therefore for biomedical diffusion
imaging applications at 7T and above where $\ttwo$ is short. However, imaging
gradients in the STEAM sequence contribute much greater diffusion weighting
than in PGSE, but are often ignored during post-processing. We demonstrate here
that this can severely bias parameter estimates.
  Method: We present models for the STEAM signal for free and restricted
diffusion that account for crusher and slice-select (butterfly) gradients to
avoid such bias. The butterfly gradients also disrupt experiment design,
typically by skewing gradient-vectors towards the slice direction. We propose a
simple compensation to the diffusion gradient vector specified to the scanner
that counterbalances the butterfly gradients to preserve the intended
experiment design.
  Results: High-field data fixed from a monkey brain experiments demonstrate
the need for both the compensation during acquisition and correct modelling
during post-processing for both diffusion tensor imaging and ActiveAx
axon-diameter index mapping. Simulations support the results and indicate a
similar need in in-vivo human applications.
  Conclusion: Correct modelling and compensation are important for practical
applications of STEAM diffusion MRI.


title: Why MgFeGe is not a superconductor

abstract:
  The recently synthesized MgFeGe compound is isostructural and isoelectronic
with superconducting LiFeAs. Both materials are paramagnetic metals at room
temperature. Inspection of their electronic structures without spin
polarization reveals hardly any difference between the two. This fact was
interpreted as evidence against popular theories relating superconductivity in
Fe-based materials with spin fluctuations. We show that in the magnetic domain
the two compounds are dramatically different, and the fact that MgFeGe does not
superconduct, is, on the contrary, a strong argument in favor of theories based
on spin fluctuations.


title:
Countable powers of compact Abelian groups in the uniform topology and
  cardinality of their dual groups

abstract:
  We equip the product of countably many copies of a compact Abelian group X
with the uniform topology, and study some properties of the topological group G
thus obtained. In particular, we determine the cardinality of the dual group of
G, when X is the circle group: it is precisely 2^c.


title:
Collective quantum coherent oscillations in a globally coupled array of
  qubits

abstract:
  We report a theoretical study of coherent collective quantum dynamic effects
in an array of N qubits (two-level systems) incorporated into a low-dissipation
resonant cavity. Individual qubits are characterized by energy level
differences $\Delta_i$ and we take into account a spread of parameters
$\Delta_i$. Non-interacting qubits display coherent quantum beatings with N
different frequencies, i.e. $\omega_i=\Delta_i/\hbar$ . Virtual emission and
absorption of cavity photons provides a long-range interaction between qubits.
In the presence of such interaction we analyze quantum correlation functions of
individual qubits $C_i(t)$ to obtain two collective quantum-mechanical coherent
oscillations, characterized by frequencies $\omega_1=\bar{\Delta}/\hbar$ and
$\omega_2=\tilde{\omega}_R$, where $\tilde{\omega}_R$ is the resonant frequency
of the cavity renormalized by interaction. The amplitude of these oscillations
can be strongly enhanced in the resonant case when $\omega_1 \simeq \omega_2$.


title:
Non-equilibrium dynamics of a confined colloidal bilayer in planar shear
  flow

abstract:
  Using Brownian dynamics (BD) simulations we investigate the impact of shear
flow on structural and dynamical properties of a system of charged colloids
confined to a narrow slit pore. Our model consists of spherical microions
interacting through a Derjaguin-Landau-Verwey-Overbeek (DLVO) and a soft-sphere
potential. The DLVO parameters were chosen according to a system of moderately
charged silica particles (with valence Z$\sim$35) in a solvent of low ionic
strength. At the confinement conditions considered, the colloids form two
well-pronounced layers. In the present study we investigate shear-induced
transitions of the translational order and dynamics in the layers, including a
discussion of the translational diffusion. In particular, we show that
diffusion in the shear-melted state can be described by an analytical model
involving a single shear-driven particle in a harmonic trap. We also explore
the emergence of zig-zag motion characterized by spatio-temporal oscillations
of the particles in the layers in the vorticity direction. Similar behavior has
been recently observed in experiments of much thicker colloidal films.


title: A Game-Tree approach to discrete infinity Laplacian with running costs

abstract:
  We give a self-contained and elementary proof for boundedness, existence, and
uniqueness of solutions to dynamic programming principles (DPP) for biased
tug-of-war games with running costs. The domain we work in is very general, and
as a special case contains metric spaces. Technically, we introduce game-trees
and show that a discretized flow converges uniformly, from which we obtain not
only the existence, but also the uniqueness. Our arguments are entirely
deterministic, and also do not rely on (semi-)continuity in any way; in
particular, we do not need to mollify the DPP at the boundary for
well-posedness.


title:
On the modulus of continuity for spectral measures in substitution
  dynamics

abstract:
  The paper gives first quantitative estimates on the modulus of continuity of
the spectral measure for weak mixing suspension flows over substitution
automorphisms, which yield information about the "fractal" structure of these
measures. The main results are, first, a Hoelder estimate for the spectral
measure of almost all suspension flows with a piecewise constant roof function;
second, a log-Hoelder estimate for self-similar suspension flows; and, third, a
Hoelder asymptotic expansion of the spectral measure at zero for such flows.
Our second result implies log-Hoelder estimates for the spectral measures of
translation flows along stable foliations of pseudo-Anosov automorphisms. A key
technical tool in the proof of the second result is an "arithmetic-Diophantine"
proposition, which has other applications. In the appendix this proposition is
used to derive new decay estimates for the Fourier transforms of Bernoulli
convolutions.


title: Adiabatic regularization for spin-1/2 fields

abstract:
  We extend the adiabatic regularization method to spin-1/2 fields. The ansatz
for the adiabatic expansion for fermionic modes differs significantly from the
WKB-type template that works for scalar modes. We give explicit expressions for
the first adiabatic orders and analyze particle creation in de Sitter
spacetime. As for scalar fields, the adiabatic method can be distinguished by
its capability to overcome the UV divergences of the particle number operator.
We also test the consistency of the extended method by working out the
conformal and axial anomalies for a Dirac field in a FLRW spacetime, in exact
agreement with those obtained from other renormalization prescriptions. We
finally show its power by computing the renormalized stress-energy tensor for
Dirac fermions in de Sitter space.


title:
Numerical stability analysis of the Pseudo-Spectral Analytical
  Time-Domain PIC algorithm

abstract:
  The pseudo-spectral analytical time-domain (PSATD) particle-in-cell (PIC)
algorithm solves the vacuum Maxwell's equations exactly, has no Courant
time-step limit (as conventionally defined), and offers substantial flexibility
in plasma and particle beam simulations. It is, however, not free of the usual
numerical instabilities, including the numerical Cherenkov instability, when
applied to relativistic beam simulations. This paper derives and solves the
numerical dispersion relation for the PSATD algorithm and compares the results
with corresponding behavior of the more conventional pseudo-spectral
time-domain (PSTD) and finite difference time-domain (FDTD) algorithms. In
general, PSATD offers superior stability properties over a reasonable range of
time steps. More importantly, one version of the PSATD algorithm, when combined
with digital filtering, is almost completely free of the numerical Cherenkov
instability for time steps (scaled to the speed of light) comparable to or
smaller than the axial cell size.

categories: physics.comp-ph physics.acc-ph physics.plasm-ph physics.space-ph


title: Polynomial Gap Extensions of the Erd\H{o}s-P\'osa Theorem

abstract:
  Given a graph $H$, we denote by ${\cal M}(H)$ all graphs that can be
contracted to $H$. The following extension of the Erd\H{o}s-P\'osa Theorem
holds: for every $h$-vertex planar graph $H$, there exists a function $f_{H}$
such that every graph $G$, either contains $k$ disjoint copies of graphs in
${\cal M}(H)$, or contains a set of $f_{H}(k)$ vertices meeting every subgraph
of $G$ that belongs in ${\cal M}(H)$. In this paper we prove that this is the
case for every graph $H$ of pathwidth at most 2 and, in particular, that
$f_{H}(k) = 2^{O(h^2)}\cdot k^{2}\cdot \log k$. As a main ingredient of the
proof of our result, we show that for every graph $H$ on $h$ vertices and
pathwidth at most 2, either $G$ contains $k$ disjoint copies of $H$ as a minor
or the treewidth of $G$ is upper-bounded by $2^{O(h^2)}\cdot k^{2}\cdot \log
k$. We finally prove that the exponential dependence on $h$ in these bounds can
be avoided if $H=K_{2,r}$. In particular, we show that $f_{K_{2,r}}=O(r^2\cdot
k^2)$


title:
Dileptons from correlated D- and $\bar{\text{D}}$-meson decays in the
  invariant mass range of the QGP thermal radiation using the UrQMD hybrid
  model

abstract:
  Relativistic heavy-ion collisions produce a hot and dense thermalized medium,
that is expected to emit thermal radiation in form of dileptons. These
dileptons are not affected by the strong force and are therefore a clean probe
for the possible creation of a Quark Gluon Plasma (QGP). However, electroweak
decays of open-charm mesons are expected to induce a substantial background in
the invariant mass region between the $\phi$ and $J/\Psi$ peak ($1\,\text{GeV}
\lesssim M_{\ell^+ \ell^-} \lesssim 3 \,\text{GeV}$) of the thermal QGP
radiation. To evaluate this background radiation we apply a Langevin approach
for the transport of charm quarks in the UrQMD (hydrodynamics + Boltzmann)
hybrid model. Due to the inclusion of event-by-event fluctuations and a full
(3+1)-dimensional hydrodynamic evolution, the UrQMD hybrid approach provides a
more realistic model for the evolution of the matter produced in heavy ion
collisions as compared to simple homogeneous fireball expansions usually
employed before. As drag and diffusion coefficients we use a resonance approach
for elastic heavy-quark scattering and assume a decoupling temperature of the
charm quarks from the hot medium of $130\,\text{MeV}$. For the hadronization of
the charm quarks we employ a coalescence approach at the decoupling temperature
from the medium. In this letter we present our calculations of the D-meson
correlations and the invariant mass spectra of the dilepton decays in heavy-ion
collisions at FAIR, RHIC, and LHC energies using different interaction
scenarios.


title: Beam tail effect of performance-enhanced EC-ITC RF gun

abstract:
  Beam tail effect of multi-bunches will influence the electron beam
performances in high intensity thermionic RF gun. Beam dynamic calculations
that illustrate the working states of single and multi-pulse fed-in of
performance-enhanced EC-ITC (External Cathode Independent Tunable Cavity) RF
gun for FEL (Free Electron Laser) injector are performed to estimate extracted
bunch properties. By using both Parmela and homemade MATLAB codes, the effects
of single beam tail as well as interactions of multi-pulses are analyzed, where
ring-based electron algorithm is adopted to calculated RF fields and space
charge field. Furthermore, the procedure of unexpected deviated-energy
particles mixed with effective bunch head is described by MATLAB code as well.
As a result, performance-enhanced EC-ITC RF gun is proved to have the
capability to extract continual stable bunches which are suitable for high
requirement THz-FEL.


title: Scalar black branes with non-AdS asymptotics

abstract:
  Black brane solutions with scalar hair and with non-AdS asymptotics have
several features that make them very interesting for holographic applications:
(1) They allow to circumvent usual no-hair theorems; (2) They may have a non
singular extremal limit in the form of a scalar soliton that interpolates
between AdS and non-AdS vacua; (3) They allow for phase transitions between the
Schwarzschild-AdS (SADS) and scalar dressed black branes; (4) They give an
holographic realization of hyperscaling violation in critical systems. In this
note I illustrate these features using an exact integrable Einstein-scalar
gravity model.


title:
Characterizing the local primary dendrite arm spacing in
  directionally-solidified dendritic microstructures

abstract:
  Characterizing the spacing of primary dendrite arms in
directionally-solidified microstructures is an important step for developing
process-structure-property relationships by enabling the quantification of (i)
the influence of processing on microstructure and (ii) the influence of
microstructure on properties. In this work, we utilized a new Voronoi-based
approach for spatial point pattern analysis that was applied to an experimental
dendritic microstructure. This technique utilizes a Voronoi tessellation of
space surrounding the dendrite cores to determine nearest neighbors and the
local primary dendrite arm spacing. In addition, we compared this technique to
a recent distance-based technique and a modification to this using Voronoi
tesselations. Moreover, a convex hull-based technique was used to include edge
effects for such techniques, which can be important for thin specimens. These
methods were used to quantify the distribution of local primary dendrite arm
spacings, their spatial distribution, and their correlation with interdendritic
eutectic particles for an experimental directionally-solidified Ni-based
superalloy micrograph. This can be an important step for correlating with both
processing and properties in directionally-solidified dendritic
microstructures.


title: Mind and Matter

abstract:
  It is argued that the problem of interpreting quantum mechanics, and the
philosophical problem of consciousness, both have their roots in the same set
of misguided Cartesian assumptions. The confusions underlying those assumptions
are analyzed in detail. It is sometimes suggested that quantum mechanics might
explain consciousness. That is not the suggestion here. Rather it is suggested
that an adequate non-Cartesian philosophy would transform our understanding of
both quantum mechanics and consciousness. Consequently, it would change our
ideas as to just what it is that we are trying to explain.


title: Statistics of Dark Matter Halos from the Excursion Set Approach

abstract:
  We exploit the excursion set approach in integral formulation to derive
novel, accurate analytic approximations of the unconditional and conditional
first crossing distributions, for random walks with uncorrelated steps and
general shapes of the moving barrier; we find the corresponding approximations
of the unconditional and conditional halo mass functions for Cold Dark Matter
power spectra to represent very well the outcomes of state-of-the-art
cosmological N-body simulations. In addition, we apply these results to derive,
and confront with simulations, other quantities of interest in halo statistics,
including the rates of halo formation and creation, the average halo growth
history, and the halo bias. Finally, we discuss how our approach and main
results change when considering random walks with correlated instead of
uncorrelated steps, and Warm instead of Cold Dark Matter power spectra.


title: CUDA Leaks: Information Leakage in GPU Architectures

abstract:
  Graphics Processing Units (GPUs) are deployed on most present server,
desktop, and even mobile platforms. Nowadays, a growing number of applications
leverage the high parallelism offered by this architecture to speed-up general
purpose computation. This phenomenon is called GPGPU computing (General Purpose
GPU computing). The aim of this work is to discover and highlight security
issues related to CUDA, the most widespread platform for GPGPU computing. In
particular, we provide details and proofs-of-concept about a novel set of
vulnerabilities CUDA architectures are subject to, that could be exploited to
cause severe information leak. Following (detailed) intuitions rooted on sound
engineering security, we performed several experiments targeting the last two
generations of CUDA devices: Fermi and Kepler. We discovered that these two
families do suffer from information leakage vulnerabilities. In particular,
some vulnerabilities are shared between the two architectures, while others are
idiosyncratic of the Kepler architecture. As a case study, we report the impact
of one of these vulnerabilities on a GPU implementation of the AES encryption
algorithm. We also suggest software patches and alternative approaches to
tackle the presented vulnerabilities. To the best of our knowledge this is the
first work showing that information leakage in CUDA is possible using just
standard CUDA instructions. We expect our work to pave the way for further
research in the field.


title: The Barycentric Fixed Mass Method for Multifractal Analysis

abstract:
  We present a novel method to estimate the multifractal spectrum of point
distributions. The method incorporates two motivated criteria (barycentric
pivot point selection and non-overlapping coverage) in order to reduce edge
effects, improve precision and reduce computation time. Implementation of the
method on synthetic benchmarks demonstrates the superior performance of the
proposed method compared with existing alternatives routinely used in the
literature. Finally, we use the method to estimate the multifractal properties
of the widely studied growth process of Diffusion Limited Aggregation and
compare our results with recent and earlier studies. Our tests support the
conclusion of a genuine but weak multifractality of the central core of DLA
clusters, with Dq decreasing from 1.75+/-0.01 for q=-10 to 1.65+/-0.01 for
q=+10.


title:
Can Small Islands Protect Nearby Coasts From Tsunamis? An Active
  Experimental Design Approach

abstract:
  Small islands in the vicinity of the mainland are believed to offer
protection from wind and waves and thus coastal communities have been developed
in these areas. However, what happens when it comes to tsunamis is not clear.
Will these islands act as natural barriers ? Recent post-tsunami survey data,
supported by numerical simulations, reveal that the run-up on coastal areas
behind small islands was significantly higher than on neighboring locations not
affected by the presence of the island. To study the conditions of this run- up
amplification, we solve numerically the nonlinear shallow water equations
(NSWE). We use the simplified geometry of a conical island sitting on a flat
bed in front of a uniform sloping beach. By doing so, the experimental setup is
defined by five physical parameters, namely the island slope, the beach slope,
the water depth, the distance between the island and the plane beach and the
incoming wavelength, while the wave height was kept fixed. The objective is
twofold: Find the maximum run-up amplification with the least number of
simulations. To achieve this goal, we build an emulator based on Gaussian
Processes to guide the selection of the query points in the parameter space.


title:
Top-quark decay into Higgs boson and a light quark at next-to-leading
  order in QCD

abstract:
  Neutral flavor-changing transitions are hugely suppressed in the Standard
Model and therefore they are very sensitive to new physics. We consider the
decay rate of t->u_i h where u_i=u,c using an effective field theory approach.
We perform the calculation at NLO in QCD including the relevant dimension-six
operators. We find that at NLO the contribution from the flavor-changing
chromomagnetic operator is as important as the standard QCD correction to the
flavor-changing Yukawa coupling. In addition to improving the accuracy of the
theoretical predictions, the NLO calculation provides information on the
operator mixing under the renormalization group.


title: Geometric Complexity Theory: an introduction for geometers

abstract:
  This article is a survey of recent developments in, and a tutorial on, the
approach to P v. NP and related questions called Geometric Complexity Theory
(GCT). It is written to be accessible to graduate students. Numerous open
questions in algebraic geometry and representation theory relevant for GCT are
presented.


title:
A central limit theorem for scaled eigenvectors of random dot product
  graphs

abstract:
  We prove a central limit theorem for the components of the largest
eigenvectors of the adjacency matrix of a finite-dimensional random dot product
graph whose true latent positions are unknown. In particular, we follow the
methodology outlined in \citet{sussman2012universally} to construct consistent
estimates for the latent positions, and we show that the appropriately scaled
differences between the estimated and true latent positions converge to a
mixture of Gaussian random variables. As a corollary, we obtain a central limit
theorem for the first eigenvector of the adjacency matrix of an Erd\"os-Renyi
random graph.


title:
Measurement of the hadronic activity in events with a Z and two jets and
  extraction of the cross section for the electroweak production of a Z with
  two jets in pp collisions at sqrt(s) = 7 TeV

abstract:
  The first measurement of the electroweak production cross section of a Z
boson with two jets (Zjj) in pp collisions at sqrt(s) = 7 TeV is presented,
based on a data sample recorded by the CMS experiment at the LHC with an
integrated luminosity of 5 inverse femtobarns. The cross section is measured
for the lljj (l = e, mu) final state in the kinematic region m[ll] >50 GeV,
m[jj] > 120 GeV, transverse momenta pt[j] > 25 GeV and pseudorapidity
abs(eta[j]) < 4.0. The measurement, combining the muon and electron channels,
yields sigma = 154 +/- 24 (stat.) +/- 46 (exp. syst.) +/- 27 (th. syst.) +/- 3
(lum.) fb, in agreement with the theoretical cross section. The hadronic
activity, in the rapidity interval between the jets, is also measured. These
results establish an important foundation for the more general study of vector
boson fusion processes, of relevance for Higgs boson searches and for
measurements of electroweak gauge couplings and vector boson scattering.


title:
Genome Sequencing Highlights Genes Under Selection and the Dynamic Early
  History of Dogs

abstract:
  To identify genetic changes underlying dog domestication and reconstruct
their early evolutionary history, we analyzed novel high-quality genome
sequences of three gray wolves, one from each of three putative centers of dog
domestication, two ancient dog lineages (Basenji and Dingo) and a golden jackal
as an outgroup. We find dogs and wolves diverged through a dynamic process
involving population bottlenecks in both lineages and post-divergence gene
flow, which confounds previous inferences of dog origins. In dogs, the
domestication bottleneck was severe involving a 17 to 49-fold reduction in
population size, a much stronger bottleneck than estimated previously from less
intensive sequencing efforts. A sharp bottleneck in wolves occurred soon after
their divergence from dogs, implying that the pool of diversity from which dogs
arose was far larger than represented by modern wolf populations. Conditional
on mutation rate, we narrow the plausible range for the date of initial dog
domestication to an interval from 11 to 16 thousand years ago. This period
predates the rise of agriculture, implying that the earliest dogs arose
alongside hunter-gathers rather than agriculturists. Regarding the geographic
origin of dogs, we find that surprisingly, none of the extant wolf lineages
from putative domestication centers are more closely related to dogs, and the
sampled wolves instead form a sister monophyletic clade. This result, in
combination with our finding of dog-wolf admixture during the process of
domestication, suggests a re-evaluation of past hypotheses of dog origin is
necessary. Finally, we also detect signatures of selection, including evidence
for selection on genes implicated in morphology, metabolism, and neural
development. Uniquely, we find support for selective sweeps at regulatory sites
suggesting gene regulatory changes played a critical role in dog domestication.


title: Determination of the pion distribution amplitude

abstract:
  Right now, we have not enough knowledge to determine the hadron distribution
amplitudes (DAs) which are universal physical quantities in the high energy
processes involving hadron for applying pQCD to exclusive processes. Even for
the simplest pion, one can't discriminate from different DA models. Inversely,
one expects that processes involving pion can in principle provide strong
constraints on the pion DA. For example, the pion-photon transition form factor
(TFF) can get accurate information of the pion wave function or DA, due to the
single pion in this process. However, the data from Belle and BABAR have a big
difference on TFF in high $Q^2$ regions, at present, they are helpless for
determining the pion DA. At the present paper, we think it is still possible to
determine the pion DA as long as we perform a combined analysis of the most
existing data of the processes involving pion such as $\pi \to \mu \bar{\nu}$,
$\pi^0 \to \gamma \gamma$, $B\to \pi l \nu$, $D \to \pi l \nu$, and etc. Based
on the revised light-cone harmonic oscillator model, a convenient DA model has
been suggested, whose parameter $B$ which dominates its longitudinal behavior
for $\phi_{\pi}(x,\mu^2)$ can be determined in a definite range by those
processes. A light-cone sum rule analysis of the semi-leptonic processes $B \to
\pi l \nu$ and $D \to \pi l \nu$ leads to a narrow region $B = [0.01,0.14]$,
which indicate a slight deviation from the asymptotic DA. Then, one can predict
the behavior of the pion-photon TFF in high $Q^2$ regions which can be tested
in the future experiments. Following this way it provides the possibility that
the pion DA will be determined by the global fit finally.


title:
Engineering Quantum Spin Hall Effect in Graphene Nanoribbons via Edge
  Functionalization

abstract:
  Kane and Mele predicted that in presence of spin-orbit interaction graphene
realizes the quantum spin Hall state. However, exceptionally weak intrinsic
spin-orbit splitting in graphene ($\approx 10^{-5}$ eV) inhibits experimental
observation of this topological insulating phase. To circumvent this problem,
we propose a novel approach towards controlling spin-orbit interactions in
graphene by means of covalent functionalization of graphene edges with
functional groups containing heavy elements. Proof-of-concept first-principles
calculations show that very strong spin-orbit coupling can be induced in
realistic models of narrow graphene nanoribbons with tellurium-terminated
edges. We demonstrate that electronic bands with strong Rashba splitting as
well as the quantum spin Hall state spanning broad energy ranges can be
realized in such systems. Our work thus opens up new horizons towards
engineering topological electronic phases in nanostructures based on graphene
and other materials by means of locally introduced spin-orbit interactions.


title:
Performance of Single User vs. Multiuser Modulation in Wireless
  Multicarrier (MC) Communications

abstract:
  The main objective of this paper is to compare block transmission system
performance analytically for Code Divisional Multiple Access (CDMA) modulations
in Generalized Multicarrier environment against linear modulation techniques
for both single user and multiuser. The effectivity of GMC-CDMA for multiuser
will also be judged for different Direct Sequence CDMA (DS-CDMA) such as
MC-CDMA, MC-DS-CDMA, MC-SS-CDMA. The analytical comparison will be in terms of
computing probability of bit error for frequency selective and slow flat fading
channels for different modulation techniques. The Bit Error Rate should be a
good indication for of the performance. The tolerance characteristics of
DS-CDMA in frequency-selective channels and MC-CDMA in flat fading channels
will be shown analytically and improved capacity and Bit Error Rate performance
will be derived for Block Spread Multiuser Multicarrier by relying block symbol
spreading and Fast Fourier Transform (FFT) operations. GMC-CDMA should give
guaranteed symbol recovery regardless of channel limitations.


title: Shadowing for actions of some finitely generated groups

abstract:
  We introduce a notion of shadowing property for actions of finitely generated
groups and study its basic properties. We formulate and prove a shadowing lemma
for actions of nilpotent groups. We construct an example of a faithful linear
action of a solvable Baumslag-Solitar group and show that the shadowing
property depends on quantitative characteristics of hyperbolicity. Finally we
show that any linear action of a non-abelian free group does not have the
shadowing property.


abstract:
  We consider a PageRank model of opinion formation on Ulam networks, generated
by the intermittency map and the typical Chirikov map. The Ulam networks
generated by these maps have certain similarities with such scale-free networks
as the World Wide Web (WWW), showing an algebraic decay of the PageRank
probability. We find that the opinion formation process on Ulam networks have
certain similarities but also distinct features comparing to the WWW. We
attribute these distinctions to internal differences in network structure of
the Ulam and WWW networks. We also analyze the process of opinion formation in
the frame of generalized Sznajd model which protects opinion of small
communities.


title:
Practical decoy-state measurement-device-independent quantum key
  distribution

abstract:
  Measurement-device-independent quantum key distribution (MDI-QKD) is immune
to all the detection attacks; thus when it is combined with the decoy-state
method, the final key is unconditionally secure, even if a practical weak
coherent source is used by Alice and Bob. However, until now, the analysis of
decoy-state MDI-QKD with a weak coherent source is incomplete. In this paper,
we derive, with only vacuum+weak decoy state, some tight formulas to estimate
the lower bound of yield and the upper bound of error rate for the fraction of
signals in which both Alice and Bob send a single-photon pulse to the untrusted
third party Charlie. The numerical simulations show that our method with only
vacuum+weak decoy state can asymptotically approach the theoretical limit of
the infinite number of decoy states. Furthermore, the statistical fluctuation
due to the finite length of date is also considered based on the standard
statistical analysis.


title:
Electromagnetic signal of the QCD phase transition in neutron star
  mergers

abstract:
  Mergers of binary neutron stars create conditions of supranuclear density
$n\gtrsim n_{\rm nuc}\simeq 0.17 {\rm fm}^{-3}$ and moderate temperature
$50\lesssim T \lesssim 90 {\rm MeV}$. These events thus probe a sensitive
region of the density-temperature phase diagram of QCD matter. We study photon
production by the QCD conformal anomaly for a signal of a possible transition
to quark degrees of freedom during the merger. We discuss energy loss due to
photon radiation as a cooling mechanism that is sensitive to the bulk viscosity
and thermal conductivity of the quark matter.


title: The maximally entangled set of multipartite quantum states

abstract:
  Entanglement is a resource in quantum information theory when state
manipulation is restricted to Local Operations assisted by Classical
Communication (LOCC). It is therefore of paramount importance to decide which
LOCC transformations are possible and, particularly, which states are maximally
useful under this restriction. While the bipartite maximally entangled state is
well known (it is the only state that cannot be obtained from any other and, at
the same time, it can be transformed to any other by LOCC), no such state
exists in the multipartite case. In order to cope with this fact, we introduce
here the notion of the Maximally Entangled Set (MES) of n-partite states. This
is the set of states which are maximally useful under LOCC manipulation, i.e.
any state outside of this set can be obtained via LOCC from one of the states
within the set and no state in the set can be obtained from any other state via
LOCC. We determine the MES for states of three and four qubits and provide a
simple characterization for them. In both cases, infinitely many states are
required. However, while the MES is of measure zero for 3-qubit states, almost
all 4-qubit states are in the MES. This is because, in contrast to the 3-qubit
case, deterministic LOCC transformations are almost never possible among fully
entangled four-partite states. We determine the measure-zero subset of the MES
of LOCC convertible states. This is the only relevant class of states for
entanglement manipulation.