title:
On Asymptotic Distribution of Parameter Free tests for Ergodic Diffusion
  Processes

abstract:
  We consider two problems of constructing of goodness of fit tests for ergodic
diffusion processes. The first one is concerned with a composite basic
hypothesis for a parametric class of diffusion processes, which includes the
Ornstein-Uhlenbeck and simple switching processes. In this case we propose
asymptotically parameter free tests of Cram\'er-von Mises type. The basic
hypothesis in the second problem is simple and we propose asymptotically
distribution free tests for a wider class of trend coefficients.


title: Reply to comment on Perfect drain for the Maxwell fish eye lens

abstract:
  We reply to the comments on our paper Perfect Drain for the Maxwell fish eye
lens (NJP 13 (2011) 023038) made by Fei Sun. We believe that Sun comments have
several mistakes in theoretical concepts and simulation results.


title: Entropy, Duality and Cross Diffusion

abstract:
  This paper is devoted to the use of the entropy and duality methods for the
existence theory of reaction-cross diffusion systems consisting of two
equations, in any dimension of space. Those systems appear in population
dynamics when the diffusion rates of individuals of two species depend on the
concentration of individuals of the same species (self-diffusion), or of the
other species (cross diffusion).


title:
A large deviation principle for networks of rate neurons with correlated
  synaptic weights

abstract:
  We study the asymptotic law of a network of interacting neurons when the
number of neurons becomes infinite. Given a completely connected network of
firing rate neurons in which the synaptic weights are Gaussian correlated
random variables, we describe the asymptotic law of the network when the number
of neurons goes to infinity. We introduce the process-level empirical measure
of the trajectories of the solutions to the equations of the finite network of
neurons and the averaged law (with respect to the synaptic weights) of the
trajectories of the solutions to the equations of the network of neurons. The
main result of this article is that the image law through the empirical measure
satisfies a large deviation principle with a good rate function which is shown
to have a unique global minimum. Our analysis of the rate function allows us
also to characterize the limit measure as the image of a stationary Gaussian
measure defined on a transformed set of trajectories. This is potentially very
useful for applications in neuroscience since the Gaussian measure can be
completely characterized by its mean and spectral density. It also facilitates
the assessment of the probability of finite-size effects.


title: Tunneling through a parabolic barrier viewed from Wigner phase space

abstract:
  We analyze the tunneling of a particle through a repulsive potential
resulting from an inverted harmonic oscillator in the quantum mechanical phase
space described by the Wigner function. In particular, we solve the partial
differential equations in phase space determining the Wigner function of an
energy eigenstate of the inverted oscillator. The reflection or transmission
coefficients $R$ or $T$ are then given by the total weight of all classical
phase space trajectories corresponding to energies below, or above the top of
the barrier given by the Wigner function.


title: Invariants and K-spectrums of local theta lifts

abstract:
  Let $(G,G')$ be a type I irreducible reductive dual pair in
$\mathrm{Sp}(W_{\mathbb{R}})$. We assume that $(G,G')$ is in the stable range
where $G$ is the smaller member. Let $K$ and $K'$ be maximal compact subgroups
of $G$ and $G'$ respectively. Let $\mathfrak{g} = \mathfrak{k} \oplus
\mathfrak{p}$ and $\mathfrak{g}' = \mathfrak{k}' \oplus \mathfrak{p}'$ be the
complexified Cartan decompositions of the Lie algebras of $G$ and $G'$
respectively. Let ${\widetilde{K}}$ and ${\widetilde{K}}'$ be the inverse
images of $K$ and $K'$ in the metaplectic double cover
$\widetilde{\mathrm{Sp}}(W_\mathbb{R})$ of ${\mathrm{Sp}}(W_\mathbb{R})$. Let
$\rho$ be a genuine irreducible $(\mathfrak{g},{\widetilde{K}})$-module. Our
first main result is that if $\rho$ is unitarizable, then except for one
special case, the full local theta lift $\rho' = \Theta(\rho)$ is equal to the
local theta lift $\theta(\rho)$. Thus excluding the special case, the full
theta lift $\rho'$ is an irreducible and unitarizable
$(\mathfrak{g}',{\widetilde{K}}')$-module. Our second main result is that the
associated variety and the associated cycle of $\rho'$ are the theta lifts of
the associated variety and the associated cycle of the contragredient
representation $\rho^*$ respectively. Finally we obtain some interesting
$(\mathfrak{g},{\widetilde{K}})$-modules whose ${\widetilde{K}}$-spectrums are
isomorphic to the spaces of global sections of some vector bundles on some
nilpotent $K_\mathbb{C}$-orbits in $\mathfrak{p}^*$.


title:
Finite Element Method (Chapter from "Gratings: Theory and Numeric
  Applications")

abstract:
  In this chapter, we demonstrate a general formulation of the Finite Element
Method allowing to calculate the diffraction efficiencies from the
electromagnetic field diffracted by arbitrarily shaped gratings embedded in a
multilayered stack lightened by a plane wave of arbitrary incidence and
polarization angle. It relies on a rigorous treatment of the plane wave sources
problem through an equivalent radiation problem with localized sources. Bloch
conditions and a new Adaptative Perfectly Matched Layer have been implemented
in order to truncate the computational domain. We derive this formulation for
both mono-dimensional gratings in TE/TM polarization cases (2D or scalar case)
and for the most general bidimensional or crossed gratings (3D or vector case).
The main advantage of this formulation is its complete generality with respect
to the studied geometries and the material properties. Its principle remains
independent of both the number of diffractive elements by period and number of
stack layers. The flexibility of our approach makes it a handy and powerful
tool for the study of metamaterials, finite size photonic crystals, periodic
plasmonic structures.


title:
Existence of Bistable Waves in a Competitive Recursion System with
  Ricker Nonlinearity

abstract:
  Using an abstract scheme of monotone semiflows, the existence of bistable
traveling wave solutions of a competitive recursion system with Ricker
nonlinearity is established. The traveling wave solutions formulate the strong
inter-specific actions between two competitive species.


title: Versatile fluoride substrates for Fe-based superconducting thin films

abstract:
  We demonstrate the growth of Co-doped BaFe2As2 (Ba-122) thin films on AEF2
(001) (AE: Ca, Sr, Ba) single crystal substrates using pulsed laser deposition.
All films are grown epitaxially despite of a large misfit of -10.6% for BaF2
substrate. For all films a reaction layer is formed at the interface confirmed
by X-ray diffraction and by transmission electron microscopy. The
superconducting transition temperature of the film on CaF2 is around 27 K,
whereas the corresponding values of the other films are around 21 K. The Ba-122
on CaF2 shows identical crystalline quality and superconducting properties as
films on Fe-buffered MgO.


title:
Leveraging Automorphisms of Quantum Codes for Fault-Tolerant Quantum
  Computation

abstract:
  Fault-tolerant quantum computation is a technique that is necessary to build
a scalable quantum computer from noisy physical building blocks. Key for the
implementation of fault-tolerant computations is the ability to perform a
universal set of quantum gates that act on the code space of an underlying
quantum code. To implement such a universal gate set fault-tolerantly is an
expensive task in terms of physical operations, and any possible shortcut to
save operations is potentially beneficial and might lead to a reduction in
overhead for fault-tolerant computations. We show how the automorphism group of
a quantum code can be used to implement some operators on the encoded quantum
states in a fault-tolerant way by merely permuting the physical qubits. We
derive conditions that a code has to satisfy in order to have a large group of
operations that can be implemented transversally when combining transversal
CNOT with automorphisms. We give several examples for quantum codes with large
groups, including codes with parameters [[8,3,3]], [[15,7,3]], [[22,8,4]], and
[[31,11,5]].


title:
Design of an all-fiber broadband mid-IR source through wavelength
  translation

abstract:
  We report design of an efficient ~ 50 cm long all-fiber compact
microstructured optical fiber-based 3-4.25 um mid-IR light source with power
conversion efficiency > 28% by exploiting FWM with Er3+-doped ZBLAN fiber as
the pump.


title: Efficient implementation of Radau collocation methods

abstract:
  In this paper we define an efficient implementation of Runge-Kutta methods of
Radau IIA type, which are commonly used when solving stiff ODE-IVPs problems.
The proposed implementation relies on an alternative low-rank formulation of
the methods, for which a splitting procedure is easily defined. The linear
convergence analysis of this splitting procedure exhibits excellent properties,
which are confirmed by its performance on a few numerical tests.


title:
On the recurrence coefficients of generalized little $q$-Laguerre
  polynomials

abstract:
  In this paper we consider a semi-classical variation of the weight related to
the little $q$-Laguerre polynomials and obtain a second order second degree
discrete equation for the recurrence coefficients in the three-term recurrence
relation.


title:
How to partition or count an abstract simplicial complex, given its
  facets

abstract:
  Given are the facets of an abstract (finite) simplicial complex SC. We show
how to partition SC into few pieces, each one compactly encoded by the use of
wildcards. Such a representation is useful for the optimization of a target
function SC -> Z, as well as in combinatorial commutative algebra and Frequent
Set Mining. Merely calculating the face-numbers of SC can be done faster than
partitioning SC. Our method compares favorably to inclusion-exclusion and
binary decision diagram


title: Wigner dynamics of quantum semi-relativistic oscillator

abstract:
  The integral Wigner - Liouwille equation describing time evolution of the
semi-relativistic quantum 1D harmonic oscillator have been exactly solved by
combination of the Monte-Carlo procedure and molecular dynamics methods. The
strong influence of the relativistic effects on the time evolution of the
momentum, velocity and coordinate Wigner distribution functions and the average
values of quantum operators have been studied. Unexpected 'protuberances' in
time evolution of the distribution functions were observed. Relativistic proper
time dilation for oscillator have been calculated.


title:
Transport properties and electrical device characteristics with the
  TiMeS computational platform: application in silicon nanowires

abstract:
  Nanoelectronics requires the development of a priori technology evaluation
for materials and device design that takes into account quantum physical
effects and the explicit chemical nature at the atomic scale. Here, we present
a cross-platform quantum transport computation tool. Using first-principles
electronic structure, it allows for flexible and efficient calculations of
materials transport properties and realistic device simulations to extract
current-voltage and transfer characteristics. We apply this computational
method to the calculation of the mean free path in silicon nanowires with
dopant and surface oxygen impurities. The dependence of transport on basis set
is established, with the optimized double zeta polarized basis giving a
reasonable compromise between converged results and efficiency. The
current-voltage characteristics of ultrascaled (3 nm length) nanowire-based
transistors with p-i-p and p-n-p doping profiles are also investigated. It is
found that charge self-consistency affects the device characteristics more
significantly than the choice of the basis set. These devices yield
source-drain tunneling currents in the range of 0.5 nA (p-n-p junction) to 2 nA
(p-i-p junction), implying that junctioned transistor designs at these length
scales would likely fail to keep carriers out of the channel in the off-state.


title:
On the anomalous enhancement observed in $B \to D^{(*)} \, \tau \, {\bar
  \nu}_\tau $ decays

abstract:
  The BaBar measurements of the ratios ${\cal R}(D^{(*)})=\frac{{\cal B}(B \to
D^{(*)} \tau {\bar \nu}_\tau)}{{\cal B}(B \to D^{(*)} \mu {\bar \nu}_\mu)}$
deviate from the standard model expectation, while new results on the purely
leptonic $B \to \tau {\bar \nu}_\tau$ mode show a better consistency with the
standard model, within the uncertainties. In a new physics scenario, one
possibility to accomodate these two experimental facts consists in considering
an additional tensor operator in the effective weak hamiltonian. We study the
effects of such an operator in a set of observables, in semileptonic $B \to
D^{(*)}$ modes as well as in semileptonic $B$ and $B_s$ decays to excited
positive parity charmed mesons.


title: The price of bandit information in multiclass online classification

abstract:
  We consider two scenarios of multiclass online learning of a hypothesis class
$H\subseteq Y^X$. In the {\em full information} scenario, the learner is
exposed to instances together with their labels. In the {\em bandit} scenario,
the true label is not exposed, but rather an indication whether the learner's
prediction is correct or not. We show that the ratio between the error rates in
the two scenarios is at most $8\cdot|Y|\cdot \log(|Y|)$ in the realizable case,
and $\tilde{O}(\sqrt{|Y|})$ in the agnostic case. The results are tight up to a
logarithmic factor and essentially answer an open question from (Daniely et.
al. - Multiclass learnability and the erm principle).
  We apply these results to the class of $\gamma$-margin multiclass linear
classifiers in $\reals^d$. We show that the bandit error rate of this class is
$\tilde{\Theta}(\frac{|Y|}{\gamma^2})$ in the realizable case and
$\tilde{\Theta}(\frac{1}{\gamma}\sqrt{|Y|T})$ in the agnostic case. This
resolves an open question from (Kakade et. al. - Efficient bandit algorithms
for online multiclass prediction).


title: An efficient approach to electroweak bubble velocities

abstract:
  Extensions of the Standard Model are being considered as viable settings for
a first-order electroweak phase transition which satisfy Sakharov's three
conditions for the generation of the baryon asymmetry of the Universe. These
extensions provide a sufficiently strong phase transition and remove the main
obstacles which appear in the context of the Standard Model: A far-too-high
lower bound on the Higgs mass, immediate wipeout of the newly-created baryon
asymmetry, and insufficient CP violation. We describe the Universe
hydrodynamically as a fluid coupled to the Higgs field via a phenomenological
friction term, and study the time evolution of bubbles nucleated during the
phase transition. We express the friction term in the hydrodynamic equations in
terms of the particle content of the model, calibrate the friction on the basis
of existing calculations for the Standard Model, and produce predictions for
the velocity of the expanding bubble wall in the stationary regime. This way we
develop a very efficient approach to compute bubble velocities. As an example,
we apply our formalism to the first-order phase transition of a dimension-6
extension of the Standard Model which, within the present bounds on the Higgs
mass, can reproduce the observed baryon asymmetry of the Universe. Depending on
the strength of the phase transition, the wall velocity varies from about 0.3
to approaching the speed of light. Our method can easily be adapted to compute
wall velocities in other interesting extensions of the Standard Model.


title: Counting Strings, Wound and Bound

abstract:
  We analyze zero mode counting problems for Dirac operators that find their
origin in string theory backgrounds. A first class of quantum mechanical models
for which we compute the number of ground states arises from a string winding
an isometric direction in a geometry, taking into account its energy due to
tension. Alternatively, the models arise from deforming marginal bound states
of a string winding a circle, and moving in an orthogonal geometry. After
deformation, the number of bound states is again counted by the zero modes of a
Dirac operator. We count these bound states in even dimensional asymptotically
linear dilaton backgrounds as well as in Euclidean Taub-NUT. We show multiple
pole behavior in the fugacities keeping track of a U(1) charge. We also discuss
a second class of counting problems that arises when these backgrounds are
deformed via the application of a heterotic duality transformation. We discuss
applications of our results to Appell-Lerch sums and the counting of domain
wall bound states.


title: Generalizing determinization from automata to coalgebras

abstract:
  The powerset construction is a standard method for converting a
nondeterministic automaton into a deterministic one recognizing the same
language. In this paper, we lift the powerset construction from automata to the
more general framework of coalgebras with structured state spaces. Coalgebra is
an abstract framework for the uniform study of different kinds of dynamical
systems. An endofunctor F determines both the type of systems (F-coalgebras)
and a notion of behavioural equivalence (~_F) amongst them. Many types of
transition systems and their equivalences can be captured by a functor F. For
example, for deterministic automata the derived equivalence is language
equivalence, while for non-deterministic automata it is ordinary bisimilarity.
We give several examples of applications of our generalized determinization
construction, including partial Mealy machines, (structured) Moore automata,
Rabin probabilistic automata, and, somewhat surprisingly, even pushdown
automata. To further witness the generality of the approach we show how to
characterize coalgebraically several equivalences which have been object of
interest in the concurrency community, such as failure or ready semantics.


title: Statistical Properties of Microstructure Noise

abstract:
  We study the estimation of moments and joint moments of microstructure noise.
Estimators of arbitrary order of (joint) moments are provided, for which we
establish consistency as well as central limit theorems. In particular, we
provide estimators of auto-covariances and auto-correlations of the noise.
Simulation studies demonstrate excellent performance of our estimators even in
the presence of jumps and irregular observation times. Empirical studies reveal
(moderate) positive auto-correlation of the noise for the stocks tested.


title: Influence of Departures from LTE on Oxygen Abundance Determination

abstract:
  We performed non-LTE calculations for O I with the plane-parallel model
atmospheres for a set of stellar parameters corresponding to A-K type stars.
The model atom of Przybilla et al. (2000) was updated using the best
theoretical and experimental atomic data available so far. Non-LTE leads to
strengthening the O I lines, and the difference between the non-LTE and LTE
abundances (non-LTE correction) is negative. The departures from LTE grow
toward higher effective temperature and lower surface gravity. In the entire
temperature range and log g = 4, the non-LTE correction does not exceed 0.05
dex in absolute value for O I lines in the visible spectral range. The non-LTE
corrections are significantly larger for the infrared O I 7771-5 A lines and
reach -1.9 dex in the model atmosphere with Teff = 10000 K and log g = 2. To
differentiate the effects of inelastic collisions with electrons and neutral
hydrogen atoms on the statistical equilibrium (SE) of O I, we derived the
oxygen abundance for the three well studied A-type stars Vega, Sirius, and HD
32115. For each star, non-LTE leads to smaller difference between the infrared
and visible lines. For example, for Vega, this difference reduces from 1.17 dex
in LTE down to 0.14 dex when ignoring LTE. To remove the difference between the
infrared and visible lines in A-type stars completely, one needs to reduce the
used electron-impact excitation rates by Barklem (2007) by a factor of 4. In
the case of Procyon and the Sun, inelastic collisions with H I affect the SE of
O I, and agreement between the abundances from different lines is achieved when
using the Drawin's formalism to compute collisional rates. The solar mean
oxygen abundance from the O I 6300, 6158, 7771-5, and 8446 A lines is log
epsilon = 8.74+-0.05, when using the MAFAGS-OS solar model atmosphere and log
epsilon = 8.78+-0.03, when applying the 3D corrections from the literature.


title:
On separable decompositions of quantum states with strong positive
  partial transposes

abstract:
  We analyze a class of positive partial transpose states (PPT) such that the
positivity of its partial transposition is recognized with respect to canonical
factorization of the original density operator (Cholesky block decomposition).
We call such PPT states strong PPT states (SPPT). This property, contrary to
PPT, is basis dependent. It is shown that there exists a proper subset of SPPT
states which are separable and provide a separable decomposition for any of
these states.


title:
Strain-induced structure transformations on Si(111) and Ge(111)
  surfaces: a combined density-functional and scannning tunnneling microscopy
  report

abstract:
  Si(111) and Ge(111) surface formation energies were calculated using density
functional theory for various biaxial strain states ranging from -0.04 to 0.04,
and for a wide set of experimentally observed surface reconstructions: 3x3,
5x5, 7x7 dimer-adatom-stacking fault reconstructions and c(2x8), 2x2 and
\sqrt{3}x\sqrt{3} adatoms based surfaces. The calculations are compared with
scanning tunneling microscopy data obtained on stepped Si(111) surfaces and on
Ge islands grown on a Si(111) substrate. It is shown that the surface structure
transformations observed in these strained systems are accounted for by a phase
diagram that relates the equilibrium surface structure to the applied strain.
The calculated formation energy of the unstrained Si(111)-9x9
dimer-adatom-stacking fault surface is reported for the first time and it is
higher than corresponding energies of Si(111)-5x5 and Si(111)-7x7
dimer-adatom-stacking fault surfaces as expected. We predict that the Si(111)
surface should adopt a c(2x8) reconstruction when tensile strain is above 0.03.


title:
Energy Deconvolution of Cross Section Measurements with an Application
  to the 12C(\alpha,\gamma)16O Reaction

abstract:
  A general framework for deconvoluting the effects of energy averaging on
charged-particle reaction measurements is presented. There are many potentially
correct approaches to the problem; the relative merits of some of are
discussed. These deconvolution methods are applied to recent
12C(\alpha,\gamma)16O measurements.


title:
Denominator vectors and compatibility degrees in cluster algebras of
  finite type

abstract:
  We present two simple descriptions of the denominator vectors of the cluster
variables of a cluster algebra of finite type, with respect to any initial
cluster seed: one in terms of the compatibility degrees between almost positive
roots defined by S. Fomin and A. Zelevinsky, and the other in terms of the root
function of a certain subword complex. These descriptions only rely on linear
algebra. They provide two simple proofs of the known fact that the denominator
vector of any non-initial cluster variable with respect to any initial cluster
seed has non-negative entries and is different from zero.


title: Pulsating fronts for nonlocal dispersion and KPP nonlinearity

abstract:
  In this paper we are interested in propagation phenomena for nonlocal
reaction-diffusion equations of the type: $\delta_tu = J \times u - u + f (x,
u) t \in R^+, x \in R^N$, where J is a probability density and f is a KPP
nonlinearity periodic in the x variables. Under suitable assumptions we
establish the existence of pulsating fronts describing the invasion of the 0
state by a heterogeneous state. We also give a variational characterization of
the minimal speed of such pulsating fronts and exponential bounds on the
asymptotic behavior of the solution.


title:
On the atomic orbital magnetism: A rigorous derivation of the Larmor and
  Van Vleck contributions

abstract:
  The purpose of this paper is to rigorously investigate the orbital magnetism
of core electrons in 3-dimensional crystalline ordered solids and in the
zero-temperature regime. To achieve that, we consider a non-interacting Fermi
gas subjected to an external periodic potential modeling the crystalline field
within the tight-binding approximation (i.e. when the distance between two
consecutive ions is large). For a fixed number of particles in the Wigner-Seitz
cell and in the zero-temperature limit, we derive an asymptotic expansion for
the bulk zero-field orbital susceptibility. We prove that the leading term is
the superposition of the Larmor diamagnetic contribution, generated by the
quadratic part of the Zeeman Hamiltonian, together with the 'complete' orbital
Van Vleck paramagnetic contribution, generated by the linear part of the Zeeman
Hamiltonian, and related to field-induced electronic transitions.

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


title:
On the measurement of $\chi_2(^3P_2)$ quarkonium state in the processes
  $e^++e^-\to \bar p+p$ and $\bar p+p\to e^++e^-$

abstract:
  The intermediate quarkonium state $\chi_2(^3P_2)$ in electron-positron
annihilation to proton and antiproton as well as in antiproton-proton
annihilation to electron and positron can produce backward-forward asymmetry,
when populated through two photon exchange. We use the dispersion relation
method, which permits to express the asymmetry in terms of partial widths of
quarkonium decay. The asymmetry dependence on the center of mass energy in the
range near the resonance is presented. The comparison with a similar effect in
these reactions with the neutral $Z$-boson in the intermediate state is given.
We show that these effects are $\le 10^{-3}$. The main source of asymmetry is
of pure QED origin ($\sim 10^{-2}$) which arises from the interference between
initial and final state real photon emission.


title: A generalization of L\"owner-John's ellipsoid theorem

abstract:
  We address the following generalization $P$ of the Lowner-John ellipsoid
problem. Given a (non necessarily convex) compact set $K\subset R^n$ and an
even integer $d$, find an homogeneous polynomial $g$ of degree $d$ such that
$K\subset G:=\{x:g(x)\leq1\}$ and $G$ has minimum volume among all such sets.
We show that $P$ is a convex optimization problem even if neither $K$ nor $G$
are convex! We next show that $P$ has a unique optimal solution and a
characterization with at most ${n+d-1\choose d}$ contacts points in $K\cap G$
is also provided. This is the analogue for $d\textgreater{}2$ of the
Lowner-John's theorem in the quadratic case $d=2$, but importantly, we neither
require the set $K$ nor the sublevel set $G$ to be convex. More generally,
there is also an homogeneous polynomial $g$ of even degree $d$ and a point
$a\in R^n$ such that $K\subset G\_a:=\{x:g(x-a)\leq1\}$ and $G\_a$ has minimum
volume among all such sets (but uniqueness is not guaranteed). Finally, we also
outline a numerical scheme to approximate as closely as desired the optimal
value and an optimal solution. It consists of solving a hierarchy of convex
optimization problems with strictly convex objective function and Linear Matrix
Inequality (LMI) constraints.


title:
Reactive-Ion-Etched Graphene Nanoribbons on a Hexagonal Boron Nitride
  Substrate

abstract:
  We report on the fabrication and electrical characterization of both single
layer graphene micron-sized devices and nanoribbons on a hexagonal boron
nitride substrate. We show that the micron-sized devices have significantly
higher mobility and lower disorder density compared to devices fabricated on
silicon dioxide substrate in agreement with previous findings. The transport
characteristics of the reactive-ion-etched graphene nanoribbons on hexagonal
boron nitride, however, appear to be very similar to those of ribbons on a
silicon dioxide substrate. We perform a detailed study in order to highlight
both similarities as well as differences. Our findings suggest that the edges
have an important influence on transport in reactive ion-etched graphene
nanodevices.


title: On minimal non-elementary Lie algebras

abstract:
  The class of minimal non-elementary Lie algebras over a field F are studied.
These are classified when F is algebraically closed and of characteristic
different from 2,3. The solvable algebras in this class are also characterised
over any perfect field.


title: Crystal Structure and Chemistry of Topological Insulators

abstract:
  Topological surface states, a new kind of electronic state of matter, have
recently been observed on the cleaved surfaces of crystals of a handful of
small band gap semiconductors. The underlying chemical factors that enable
these states are crystal symmetry, the presence of strong spin orbit coupling,
and an inversion of the energies of the bulk electronic states that normally
contribute to the valence and conduction bands. The goals of this review are to
briefly introduce the physics of topological insulators to a chemical audience
and to describe the chemistry, defect chemistry, and crystal structures of the
compounds in this emergent field.


title: Higgs decay into two photons from a 3HDM with flavor symmetry

abstract:
  In this short letter we show that the excess of events in the decay of Higgs
to two photons reported by ATLAS and CMS can be easily accommodated in a flavor
renormalizable three Higgs doublet model (3HDM). The model is consistent with
all fermion masses, mixing angles, and flavor changing neutral current
constraints.


title: The UV and X-ray activity of the M dwarfs within 10pc of the Sun

abstract:
  We systematically study the X-ray and ultraviolet emission of a subsample of
M dwarfs from a recent proper-motion survey, selecting all M dwarfs within 10pc
to obtain a nearly volume-limited sample (~90% completeness). Archival ROSAT,
XMM-Newton and GALEX data are combined with published spectroscopic studies of
Halpha emission and rotation to obtain a broad picture of stellar activity on M
dwarfs. We make use of synthetic model spectra to determine the relative
contributions of photospheric and chromospheric emission to the ultraviolet
flux. We also analyse the same diagnostics for a comparison sample of young M
dwarfs in the TWHya association (~10Myrs). We find that generally the emission
in the GALEX bands is dominated by the chromosphere but the photospheric
component is not negligible in early-M field dwarfs. The surface fluxes for the
Halpha, near-ultraviolet, far-ultraviolet and X-ray emission are connected via
a power law dependence. We present here for the first time such flux-flux
relations involving broad-band ultraviolet emission for M dwarfs. For given
spectral type the activity indices, defined as flux ratio between the activity
diagnostic and the bolometric flux of the star, display a spread of 2-3 dex
which is largest for M4 stars. The mean activity index for fast rotators,
likely representing the saturation level, decreases from X-rays over the FUV to
the NUV band and Halpha, i.e. the fractional radiation output increases with
atmospheric height. The comparison to the ultraviolet and X-ray properties of
TWHya members shows a drop of nearly three orders of magnitude for the
luminosity in these bands between ~10Myr and few Gyrs age. A few young field
dwarfs (< 1Gyr) in the 10pc sample bridge the gap indicating that the drop in
magnetic activity with age is a continuous process. The slope of the age decay
is steeper for the X-ray than for the UV luminosity.


title: The Chandra-COSMOS survey IV: X-ray spectra of the bright sample

abstract:
  We present the X-ray spectral analysis of the 390 brightest extragalactic
sources in the Chandra-COSMOS catalog, showing at least 70 net counts in the
0.5-7 keV band. This sample has a 100% completeness in optical-IR
identification, with 75% of the sample having a spectroscopic redshift and 25%
a photometric redshift. Our analysis allows us to accurately determine the
intrinsic absorption, the broad band continuum shape ({\Gamma}) and intrinsic
L(2-10) distributions, with an accuracy better than 30% on the spectral
parameters for 95% of the sample. The sample is equally divided in type-1
(49.7%) and type-2 AGN (48.7%) plus few passive galaxies at low z. We found a
significant difference in the distribution of {\Gamma} of type-1 and type-2,
with small intrinsic dispersion, a weak correlation of {\Gamma} with L(2-10)
and a large population (15% of the sample) of high luminosity, highly obscured
(QSO2) sources. The distribution of the X ray/Optical flux ratio (Log(FX /Fi))
for type-1 is narrow (0 < X/O < 1), while type-2 are spread up to X/O = 2. The
X/O correlates well with the amount of X-ray obscuration. Finally, a small
sample of Compton thick candidates and peculiar sources is presented. In the
appendix we discuss the comparison between Chandra and XMM-Newton spectra for
280 sources in common. We found a small systematic difference, with XMM-Newton
spectra that tend to have softer power-laws and lower obscuration.


title: Inertial effect on spin orbit coupling and spin transport

abstract:
  We theoretically study the renormalization of inertial effects on the spin
dependent transport of conduction electrons in a semiconductor by taking into
account the interband mixing on the basis of k.p perturbation theory. In our
analysis, for the generation of spin current we have used the extended Drude
model where the spin orbit coupling plays an important role. We predict
enhancement of the spin current resulting from the rerormalized spin orbit
coupling effective in our model in cubic and non cubic crystal. Attention has
been paid to clarify the importance of gauge fields in the spin transport of
this inertial system. A theoretical proposition of a perfect spin filter has
been done through the Aharanov Casher like phase corresponding to this inertial
system. For a time dependent acceleration, effect of $\vec{k} . \vec{p}$
perturbation on the spin current and spin polarization has also been addressed.
Furthermore, achievement of a tunable source of polarized spin current through
the non uniformity of the inertial spin orbit coupling strength has also been
discussed.


title: Lightweight Lempel-Ziv Parsing

abstract:
  We introduce a new approach to LZ77 factorization that uses O(n/d) words of
working space and O(dn) time for any d >= 1 (for polylogarithmic alphabet
sizes). We also describe carefully engineered implementations of alternative
approaches to lightweight LZ77 factorization. Extensive experiments show that
the new algorithm is superior in most cases, particularly at the lowest memory
levels and for highly repetitive data. As a part of the algorithm, we describe
new methods for computing matching statistics which may be of independent
interest.


title:
Some counterexamples on the behaviour of real-valued functions and their
  derivatives

abstract:
  We discuss some surprising phenomena from basic calculus related to
oscillating functions and to the theorem on the differentiability of inverse
functions. Among other things, we see that a continuously differentiable
function with a strict minimum doesn't have to be decreasing to the left nor
increasing to the right of the minimum, we present a function whose derivative
is discontinuous at one point and has a strict minimum at this point (i.e. it
oscillates only in one direction), we compare several definitions of inflection
point, and we discuss a general version of the theorem on the derivative of
inverse functions where continuity of the inverse function is assumed merely at
one point.


title: A note on static metrics: the degenerate case

abstract:
  We give the necessary and sufficient conditions for a 3-metric to be the
adapted spatial metric of a static vacuum solution. This work accomplishes for
the degenerate cases the already known study for the regular ones (Bartnik and
Tod 2006 {\it Class. Quantum Grav.} {\bf 23} 569-571).


title:
The Invalidity of the Laplace Law for Biological Vessels and of
  Estimating Elastic Modulus from Total Stress vs. Strain: a New Practical
  Method

abstract:
  The quantification of the stiffness of tubular biological structures is often
obtained, both in vivo and in vitro, as the slope of total transmural hoop
stress plotted against hoop strain. Total hoop stress is typically estimated
using the "Laplace law." We show that this procedure is fundamentally flawed
for two reasons: Firstly, the Laplace law predicts total stress incorrectly for
biological vessels. Furthermore, because muscle and other biological tissue are
closely volume-preserving, quantifications of elastic modulus require the
removal of the contribution to total stress from incompressibility. We show
that this hydrostatic contribution to total stress has a strong
material-dependent nonlinear response to deformation that is difficult to
predict or measure. To address this difficulty, we propose a new practical
method to estimate a mechanically viable modulus of elasticity that can be
applied both in vivo and in vitro using the same measurements as current
methods, with care taken to record the reference state. To be insensitive to
incompressibility, our method is based on shear stress rather than hoop stress,
and provides a true measure of the elastic response without application of the
Laplace law. We demonstrate the accuracy of our method using a mathematical
model of tube inflation with multiple constitutive models. We also re-analyze
an in vivo study from the gastro-intestinal literature that applied the
standard approach and concluded that a drug-induced change in elastic modulus
depended on the protocol used to distend the esophageal lumen. Our new method
removes this protocol-dependent inconsistency in the previous result.


title:
Detecting non-sinusoidal periodicities in observational data: the von
  Mises periodogram for variable stars and exoplanetary transits

abstract:
  This paper introduces an extension of the linear least-squares (or
Lomb-Scargle) periodogram for the case when the model of the signal to be
detected is non-sinusoidal and depends on unknown parameters in a non-linear
manner. The attention is paid to the problem of estimating the statistical
significance of candidate periodicities found using such non-linear
periodograms. This problem is related to the task of quantifying the
distributions of maximum values of these periodograms. Based on recent results
in the mathematical theory of extreme values of random field (the generalized
Rice method), we give a general approach to find handy analytic approximation
for these distributions. This approximation has the general form $e^{-z}
P(\sqrt z)$, where $P$ is an algebraic polynomial and $z$ being the periodogram
maximum.
  The general tools developed in this paper can be used in a wide variety of
astronomical applications, for instance in the studies of variable stars and
extrasolar planets. For this goal, we develop and consider in details the
so-called von Mises periodogram: a specialized non-linear periodogram where the
signal is modelled by the von Mises periodic function $\exp(\nu \cos \omega
t)$. This simple function with an additional non-linear parameter $\nu$ can
model lightcurves of many astronomical objects that show periodic photometric
variability of different nature. We prove that our approach can be perfectly
applied to this non-linear periodogram.
  We provide a package of auxiliary C++ programs, attached as the online-only
material. They should faciliate the use of the von Mises periodogram in
practice.


title: A Flavorful Top-Coloron Model

abstract:
  In this paper we introduce a simple renormalizable model of an extended color
gauge sector in which the third-generation quarks couple differently than the
lighter quarks. In addition to a set of heavy color-octet vector bosons
(colorons), the model also contains a set of heavy weak vector quarks. Mixing
between the third-generation of quarks and the first two is naturally small,
and occurs only through the (suppressed) mixing of all three generations with
the heavy vector quarks. We discuss the constraints on this model arising from
limits on flavor-changing neutral currents and from collider searches for the
colorons and vector quarks, and discuss the prospects for discovery at the LHC.


title:
Luminosity-dependent unification of Active Galactic Nuclei and the X-ray
  Baldwin effect

abstract:
  The existence of an anti-correlation between the equivalent width (EW) of the
narrow core of the iron Kalpha line and the luminosity of the continuum (i.e.
the X-ray Baldwin effect) in type-I active galactic nuclei has been confirmed
over the last years by several studies carried out with XMM-Newton, Chandra and
Suzaku. However, so far no general consensus on the origin of this trend has
been reached. Several works have proposed the decrease of the covering factor
of the molecular torus with the luminosity (in the framework of the
luminosity-dependent unification models) as a possible explanation for the
X-ray Baldwin effect. Using the fraction of obscured sources measured by recent
X-ray and IR surveys as a proxy of the half-opening angle of the torus, and the
recent Monte-Carlo simulations of the X-ray radiation reprocessed by a
structure with a spherical-toroidal geometry by Ikeda et al. (2009) and
Brightman & Nandra (2011), we test the hypothesis that the X-ray Baldwin effect
is related to the decrease of the half-opening angle of the torus with the
luminosity. Simulating the spectra of an unabsorbed population with a
luminosity-dependent covering factor of the torus as predicted by recent X-ray
surveys, we find that this mechanism is able to explain the observed X-ray
Baldwin effect. Fitting the simulated data with a log-linear L_{2-10keV}-EW
relation, we found that in the Seyfert regime (L_{2-10keV}< 10^44.2 erg s^-1)
luminosity-dependent unification produces a slope consistent with the
observations for average values of the equatorial column densities of the torus
of log N_H^T > 23.1. In the quasar regime (L_{2-10 keV}> 10^44.2 erg s^-1) a
decrease of the covering factor of the torus with the luminosity slower than
that observed in the Seyfert regime (as found by recent hard X-ray surveys) is
able to reproduce the observations for 23.2 < log N_H^T < 24.2.


title:
Linear And Nonlinear Arabesques: A Study Of Closed Chains Of Negative
  2-Element Circuits

abstract:
  In this paper we consider a family of dynamical systems that we call
"arabesques", defined as closed chains of 2-element negative circuits. An
$n$-dimensional arabesque system has $n$ 2-element circuits, but in addition,
it displays by construction, two $n$-element circuits which are both positive
vs one positive and one negative, depending on the parity (even or odd) of the
dimension $n$. In view of the absence of diagonal terms in their Jacobian
matrices, all these dynamical systems are conservative and consequently, they
can not possess any attractor. First, we analyze a linear variant of them which
we call "arabesque 0" or for short "A0". For increasing dimensions, the
trajectories are increasingly complex open tori. Next, we inserted a single
cubic nonlinearity that does not affect the signs of its circuits (that we call
"arabesque 1" or for short "A1"). These systems have three steady states,
whatever the dimension is, in agreement with the order of the nonlinearity. All
three are unstable, as there can not be any attractor in their state-space. The
3D variant (that we call for short "A1\_3D") has been analyzed in some detail
and found to display a complex mixed set of quasi-periodic and chaotic
trajectories. Inserting $n$ cubic nonlinearities (one per equation) in the same
way as above, we generate systems "A2\_$n$D". A2\_3D behaves essentially as
A1\_3D, in agreement with the fact that the signs of the circuits remain
identical. A2\_4D, as well as other arabesque systems with even dimension, has
two positive $n$-circuits and nine steady states. Finally, we investigate and
compare the complex dynamics of this family of systems in terms of their
symmetries.


title: Measurement of the \Lambda_b^0, \Xi_b^- and \Omega_b^- baryon masses

abstract:
  Bottom baryons decaying to a J/\psi\ meson and a hyperon are reconstructed
using 1.0 fb^{-1} of data collected in 2011 with the LHCb detector. Significant
\Lambda_b^0 \rightarrow J/\psi \Lambda, \Xi_b^-\rightarrow J/\psi \Xi^- and
\Omega_b^- \rightarrow J/\psi \Omega^- signals are observed and the
corresponding masses are measured to be M(\Lambda_b^0) = 5619.53 \pm 0.13
(stat) \pm 0.45 (syst) MeV/c^2, M(\Xi_b^-) = 5795.8 \pm 0.9 (stat) \pm 0.4
(syst) MeV/c^2, M(\Omega_b^-) = 6046.0 \pm 2.2 (stat) \pm 0.5 (syst) MeV/c^2,
while the differences with respect to the \Lambda_b^0 mass are
M(\Xi_b^-)-M(\Lambda_b^0) = 176.2 \pm 0.9 (stat) \pm 0.1 (syst) MeV/c^2,
M(\Omega_b^-)-M(\Lambda_b^0) = 426.4 \pm 2.2 (stat) \pm 0.4 (syst) MeV/c^2.
These are the most precise mass measurements of the \Lambda_b^0, \Xi_b^- and
\Omega_b^- baryons to date. Averaging the above \Lambda_b^0 mass measurement
with that published by LHCb using 35 pb^{-1} of data collected in 2010 yields
M(\Lambda_b^0) = 5619.44 \pm 0.13 (stat) \pm 0.38 (syst) MeV/c^2.


title:
Tight-binding description of intrinsic superconducting correlations in
  multilayer graphene

abstract:
  Using highly efficient GPU-based simulations of the tight-binding
Bogoliubov-de Gennes equations we solve self-consistently for the pair
correlation in rhombohedral (ABC) and Bernal (ABA) multilayer graphene by
considering a finite intrinsic s-wave pairing potential. We find that the two
different stacking configurations have opposite bulk/surface behavior for the
order parameter. Surface superconductivity is robust for ABC stacked multilayer
graphene even at very low pairing potentials for which the bulk order parameter
vanishes, in agreement with a recent analytical approach. In contrast, for
Bernal stacked multilayer graphene, we find that the order parameter is always
suppressed at the surface and that there exists a critical value for the
pairing potential below which no superconducting order is achieved. We
considered different doping scenarios and find that homogeneous doping strongly
suppresses surface superconductivity while non-homogeneous field-induced doping
has a much weaker effect on the superconducting order parameter. For multilayer
structures with hybrid stacking (ABC and ABA) we find that when the thickness
of each region is small (few layers), high-temperature surface
superconductivity survives throughout the bulk due to the proximity effect
between ABC/ABA interfaces where the order parameter is enhanced.


title:
Effects of Transverse Magnetic Anisotropy on Current-Induced Spin
  Switching

abstract:
  Spin-polarized transport through bistable magnetic adatoms or single-molecule
magnets (SMMs), which exhibit both uniaxial and transverse magnetic anisotropy,
is considered theoretically. The main focus is on the impact of transverse
anisotropy on transport characteristics and the adatom's/SMM's spin. In
particular, we analyze the role of quantum tunneling of magnetization (QTM) in
the mechanism of the current-induced spin switching, and show that the QTM
phenomenon becomes revealed as resonant peaks in the average values of the
molecule's spin and in the charge current. These features appear at some
resonant fields and are observable when at least one of the electrodes is
ferromagnetic. We also show that the conductance generally depends on the
relative orientation of the average adatom's/SMM's spin and electrode's
magnetic moment. This spin-valve like magnetoresistance effect can be used to
control spin switching of the adatom's/SMM's spin.


title:
Structures, optical properties, and electrical transport processes of
  SnO$_2$ films with oxygen deficiencies

abstract:
  The structures, optical and electrical transport properties of SnO$_2$ films,
fabricated by rf sputtering method at different oxygen partial pressures, were
systematically investigated. It has been found that preferred growth
orientation of SnO$_2$ film is strongly related to the oxygen partial pressure
during deposition, which provides an effective way to tune the surface texture
of SnO$_2$ film. All films reveal relatively high transparency in the visible
range, and both the transmittance and optical band gap increase with increasing
oxygen partial pressure. The temperature dependence of resisitivities was
measured from 380 K down to liquid helium temperatures. At temperature above
$\sim 80$ K, besides the nearest-neighbor-hopping process, thermal activation
processes related to two donor levels ($\sim 30$ and $\sim 100$ meV below the
conduction band minimum) of oxygen vacancies are responsible for the charge
transport properties. Below $\sim 80$ K, Mott variable-range-hopping conduction
process governs the charge transport properties at higher temperatures, while
Efros-Shklovskii variable-range-hopping conduction process dominates the
transport properties at lower temperatures. Distinct crossover from Mott type
to Efros-Shklovskii type variable-range-hopping conduction process at several
to a few tens kelvin are observed for all SnO$_2$ films.


title:
An approach to quantum transport based on reduced hierarchy equations of
  motion: Application to a resonant tunneling diode

abstract:
  The quantum dissipative dynamics of a tunneling process through double
barrier structures is investigated on the basis of a rigorous treatment for the
first time. We employ a Caldeira-Leggett Hamiltonian with an effective
potential calculated self-consistently, accounting for the electron
distribution. With this Hamiltonian, we use the reduced hierarchy equations of
motion in the Wigner space representation to study the effects of non-Markovian
thermal fluctuations and dissipation at finite temperature in a rigorous
manner. Hysteresis, double plateau-like behavior, and self-excited current
oscillation are observed in a negative differential resistance (NDR) region of
the current-voltage curve. We find that while most of the current oscillations
decay in time in the NDR region, there is a steady oscillation characterized by
a tornado-like rotation in the Wigner space in the upper plateau of the NDR
region.


title:
Luttinger liquid and polaronic effects in electron transport through a
  molecular transistor

abstract:
  Electron transport through a single-level quantum dot weakly coupled to
Luttinger liquid leads is considered in the master equation approach. It is
shown that for a weak or moderately strong interaction the differential
conductance demonstrates resonant-like behavior as a function of bias and gate
voltages. The inelastic channels associated with vibron-assisted electron
tunnelling can even dominate electron transport for a certain region of
interaction strength. In the limit of strong interaction resonant behavior
disappears and the differential conductance scales as a power low on
temperature (linear regime) or on bias voltage (nonlinear regime).


title:
Performance Evaluation of Sparse Matrix Multiplication Kernels on Intel
  Xeon Phi

abstract:
  Intel Xeon Phi is a recently released high-performance coprocessor which
features 61 cores each supporting 4 hardware threads with 512-bit wide SIMD
registers achieving a peak theoretical performance of 1Tflop/s in double
precision. Many scientific applications involve operations on large sparse
matrices such as linear solvers, eigensolver, and graph mining algorithms. The
core of most of these applications involves the multiplication of a large,
sparse matrix with a dense vector (SpMV). In this paper, we investigate the
performance of the Xeon Phi coprocessor for SpMV. We first provide a
comprehensive introduction to this new architecture and analyze its peak
performance with a number of micro benchmarks. Although the design of a Xeon
Phi core is not much different than those of the cores in modern processors,
its large number of cores and hyperthreading capability allow many application
to saturate the available memory bandwidth, which is not the case for many
cutting-edge processors. Yet, our performance studies show that it is the
memory latency not the bandwidth which creates a bottleneck for SpMV on this
architecture. Finally, our experiments show that Xeon Phi's sparse kernel
performance is very promising and even better than that of cutting-edge general
purpose processors and GPUs.


title:
Cognitive Access Policies under a Primary ARQ process via
  Forward-Backward Interference Cancellation

abstract:
  This paper introduces a novel technique for access by a cognitive Secondary
User (SU) using best-effort transmission to a spectrum with an incumbent
Primary User (PU), which uses Type-I Hybrid ARQ. The technique leverages the
primary ARQ protocol to perform Interference Cancellation (IC) at the SU
receiver (SUrx). Two IC mechanisms that work in concert are introduced: Forward
IC, where SUrx, after decoding the PU message, cancels its interference in the
(possible) following PU retransmissions of the same message, to improve the SU
throughput; Backward IC, where SUrx performs IC on previous SU transmissions,
whose decoding failed due to severe PU interference. Secondary access policies
are designed that determine the secondary access probability in each state of
the network so as to maximize the average long-term SU throughput by
opportunistically leveraging IC, while causing bounded average long-term PU
throughput degradation and SU power expenditure. It is proved that the optimal
policy prescribes that the SU prioritizes its access in the states where SUrx
knows the PU message, thus enabling IC. An algorithm is provided to optimally
allocate additional secondary access opportunities in the states where the PU
message is unknown. Numerical results are shown to assess the throughput gain
provided by the proposed techniques.


title: Extracting TMDs from CLAS12 data

abstract:
  We present studies of double longitudinal spin asymmetries in semi-inclusive
deep inelastic scattering using a new dedicated Monte Carlo generator, which
includes quark intrinsic transverse momentum within the generalized parton
model based on the fully differential cross section for the process.
Additionally we employ Bessel-weighting to the MC events to extract transverse
momentum dependent parton distribution functions and also discuss possible
uncertainties due to kinematic correlation effects.


title:
Hemispheric Asymmetries of Solar Photospheric Magnetism: Radiative,
  Particulate, and Heliospheric Impacts

abstract:
  Among many other measurable quantities the summer of 2009 saw a considerable
low in the radiative output of the Sun that was temporally coincident with the
largest cosmic ray flux ever measured at 1AU. A hemispheric asymmetry in
magnetic activity is clearly observed and its evolution monitored and the
resulting (prolonged) magnetic imbalance must have had a considerable impact on
the structure and energetics of the heliosphere. While we cannot uniquely tie
the variance and scale of the surface magnetism to the dwindling radiative and
particulate output of the star, or the increased cosmic ray flux through the
2009 minimum, the timing of the decline and rapid recovery in early 2010 would
appear to inextricably link them. These observations support a picture where
the Sun's hemispheres are significantly out of phase with each other. Studying
historical sunspot records with this picture in mind shows that the northern
hemisphere has been leading since the middle of the last century and that the
hemispheric "dominance" has changed twice in the past 130 years. The
observations presented give clear cause for concern, especially with respect to
our present understanding of the processes that produce the surface magnetism
in the (hidden) solar interior - hemispheric asymmetry is the normal state -
the strong symmetry shown in 1996 was abnormal. Further, these observations
show that the mechanism(s) which create and transport the magnetic flux
magnetic flux are slowly changing with time and, it appears, with only loose
coupling across the equator such that those asymmetries can persist for a
considerable time. As the current asymmetry persists and the basal energetics
of the system continue to dwindle we anticipate new radiative and particulate
lows coupled with increased cosmic ray fluxes heading into the next solar
minimum.


title:
Dirac Point Structure in a Bose-Einstein Condensate in a Honeycomb
  Optical Lattice

abstract:
  We study the Bose-Einstein condensate in a honeycomb optical lattice within
Bogoliubov theory and find that for a ${\bf k} = 0$ condensate, the Dirac
points appear in the Bogoliubov excitation spectrum when $0 < \beta < 2$, which
illustrates that the bose-bose interaction does not change the Dirac point
structure but only give a modification of the velocity of the Dirac cone. When
the bosons are driven to condense at ${\bf k} = {\bf K}$, however, we find that
the topology of the Dirac points will be altered by arbitrary weak interaction.
Furthermore, we find that the next-nearest-neighbor hopping in an isotropic and
an anisotropic lattice has different effects to the dynamics of the condensate
and it should be taken into account when the lattice is not sufficiently deep.


title: On the measure division construction of \Lambda-coalescents

abstract:
  This paper provides a new construction of \Lambda-coalescents called "measure
division construction". This construction is pathwise and consists of dividing
the characteristic measure \Lambda into several parts and adding them one by
one to have a whole process. Using this construction, a "universal"
normalization factor \mu^{(n)} for the randomly chosen external branch length
T^{(n)} has been discovered for a class of coalescents. This class of
coalescents covers processes similar to Bolthausen-Sznitman coalescent, the
coalescents without proper frequencies, and also others.


title:
Two-dimensional Ising model in a finite magnetic field for the square
  lattice of infinite sites-Partition function and Magnetization

abstract:
  The partition function and magnetization equations are derived for the
two-dimensional nearest neighbour Ising models in a magnetic field.


title:
Matrix of integrated superconducting single-photon detectors with high
  timing resolution

abstract:
  We demonstrate a large grid of individually addressable superconducting
single photon detectors on a single chip. Each detector element is fully
integrated into an independent waveguide circuit with custom functionality at
telecom wavelengths. High device density is achieved by fabricating the
nanowire detectors in traveling wave geometry directly on top of
silicon-on-insulator waveguides. Our superconducting single-photon detector
matrix includes detector designs optimized for high detection efficiency, low
dark count rate and high timing accuracy. As an example, we exploit the high
timing resolution of a particularly short nanowire design to resolve individual
photon round-trips in a cavity ring-down measurement of a silicon ring
resonator.


title:
Obtaining the Probability Vector Current Density in Canonical Quantum
  Mechanics by Linear Superposition

abstract:
  The quantum mechanics status of the probability vector current density has
long seemed to be marginal. On one hand no systematic prescription for its
construction is provided, and the special examples of it that are obtained for
particular types of Hamiltonian operator could conceivably be attributed to
happenstance. On the other hand this concept's key physical interpretation as
local average particle flux, which flows from the equation of continuity that
it is supposed to satisfy in conjunction with the probability scalar density,
has been claimed to breach the uncertainty principle. Given the dispiriting
impact of that claim, we straightaway point out that the subtle directional
nature of the uncertainty principle makes it consistent with the measurement of
local average particle flux. We next focus on the fact that the unique
closed-form linear-superposition quantization of any classical Hamiltonian
function yields in tandem the corresponding unique linear-superposition
closed-form divergence of the probability vector current density. Because the
probability vector current density is linked to the quantum physics only
through the occurrence of its divergence in the equation of continuity, it is
theoretically most appropriate to construct this vector field exclusively from
its divergence -- analysis of the best-known "textbook" special example of a
probability vector current density shows that it is thus constructed. That
special example in fact leads to the physically interesting "Ehrenfest
subclass" of probability vector current densities, which are closely related to
their classical peers.


title: THz Generation and Detection on Dirac Fermions in Topological Insulators

abstract:
  This study shows that a terahertz (THz) wave can be generated from the (001)
surface of cleaved Bi$_{\textrm{2}}$Se$_{\textrm{3}}$ and Cu-doped
Bi$_{\textrm{2}}$Se$_{\textrm{3}}$ single crystals using 800 nm femtosecond
pulses. The generated THz power is strongly dependent on the carrier
concentration of the crystals. An examination of the dependence reveals the
two-channel free carrier absorption to which Dirac fermions are indispensable.
Dirac fermions in Bi$_{\textrm{2}}$Se$_{\textrm{3}}$ are significantly better
absorbers of THz radiation than bulk carriers at room temperature. Moreover,
the characteristics of THz emission confirm the existence of a recently
proposed surface phonon branch that is normalized by Dirac fermions.


title: Quantum Anomalous Hall Effect in 2D Organic Topological Insulators

abstract:
  Quantum anomalous Hall effect (QAHE) is a fundamental transport phenomenon in
the field of condensed-matter physics. Without external magnetic field,
spontaneous magnetization combined with spin-orbit coupling give rise to a
quantized Hall conductivity. So far, a number of theoretical proposals have
been made to realize the QAHE, but all based on inorganic materials. Here,
using first-principles calculations, we predict a family of 2D organic
topological insulators (OTIs) for realizing the QAHE. Designed by assembling
molecular building blocks of triphenyl-transition-metal compounds into a
hexagonal lattice, this new classes of organic materials are shown to have a
nonzero Chern number and exhibit a gapless chiral edge state within the Dirac
gap.


title: Local Redesigning of Airspace Sectors

abstract:
  In this paper we study the Airspace Sectorization Problem (ASP) where the
goal is to find an optimal partition (sectorization) of the airspace into a
certain number of sectors, each managed by an air traffic controller. The
objective of the ASP is to find a "well-balanced" sectorization that
distributes the workload evenly among the controllers. We formulate the ASP as
a partitioning problem of a set of moving points in a polygonal domain. In
addition to the requirement of balancing the workload, we introduce
restrictions on the geometry of the sectorization which come from the Air
Traffic Management aspects. We investigate several versions of the problem that
arise from different definitions of the notion of the workload and various
choices of geometric restrictions on the sectorization. We conclude that most
of the formulations of the problem, except maybe in some trivial cases, are
NP-hard. Finally, we propose a Local Redesigning Method (LRM), a heuristic
algorithm that rebalances a given sectorization by adjusting the boundaries of
the sectors. We evaluate LRM experimentally on synthetically generated
scenarios as well as on the real historical traffic data. We demonstrate that
the sectorizations produced by our method are superior in comparison with the
current sectorizations of the US airspace.


title:
On new approach Hadamard-type inequalities for s-geometrically convex
  functions

abstract:
  In this paper we achieve some new Hadamard type inequalities using elementary
well known inequalities for functions whose first derivatives absolute values
are s-geometrically and geometrically convex. And also we get some applications
for special means for positive numbers.


title: Pseudo Parity-Time Symmetry in Optical Systems

abstract:
  We introduce a novel concept of the {\em pseudo} parity-time ($\mathcal{PT}$)
symmetry in periodically modulated optical systems with balanced gain and loss.
We demonstrate that whether the original system is $\mathcal{PT}$-symmetric or
not, we can manipulate the property of the $\mathcal{PT}$ symmetry by applying
a periodic modulation in such a way that the effective system derived by the
high-frequency Floquet method is $\mathcal{PT}$ symmetric. If the original
system is non-$\mathcal{PT}$ symmetric, the $\mathcal{PT}$ symmetry in the
effective system will lead to quasi-stationary propagation that can be
associated with the \emph{pseudo $\mathcal{PT}$ symmetry}. Our results provide
a promising approach for manipulating the $\mathcal{PT}$ symmetry of realistic
systems.


title:
Breaking the thermally induced write error in heat assisted recording by
  using low and high Tc materials

abstract:
  Heat assisted recording is believed as a key technology in order to further
increase the areal density of magnetic recording. In the work of Richter et al.
[Richter et al. J. Appl. Phys. 111, 033909 (2012)] it is stated that storage
densities will be limited to 15 to 20 Tbit/in2 due to thermally induced write
errors. In this letter we propose a composite structure consisting of two
materials with different Curie temperatures. A hard magnetic layer is on top of
a high Tc soft magnetic layer. In this composite material the thermal write
error is negligible up to areal densities of 50 to 100 Tbit/in2. It is shown
that the effective thermal field gradient, which is reduced in this composite
structure, is not relevant for a possible increase of the transition jitter.
The transition jitter is dominated by a small distribution of the Curie
temperature. The smallest jitter is obtained for the composite structure.


title: The transfer matrix in four-dimensional Causal Dynamical Triangulations

abstract:
  Causal Dynamical Triangulations is a background independent approach to
quantum gravity. In this paper we introduce a phenomenological transfer matrix
model, where at each time step a reduced set of quantum states is used. The
states are solely characterized by the discretized spatial volume. Using Monte
Carlo simulations we determine the effective transfer matrix elements and
extract the effective action for the scale factor. In this framework no degrees
of freedom are frozen, however, the obtained action agrees with the
minisuperspace model.


title: Analysis Based Blind Compressive Sensing

abstract:
  In this work we address the problem of blindly reconstructing compressively
sensed signals by exploiting the co-sparse analysis model. In the analysis
model it is assumed that a signal multiplied by an analysis operator results in
a sparse vector. We propose an algorithm that learns the operator adaptively
during the reconstruction process. The arising optimization problem is tackled
via a geometric conjugate gradient approach. Different types of sampling noise
are handled by simply exchanging the data fidelity term. Numerical experiments
are performed for measurements corrupted with Gaussian as well as impulsive
noise to show the effectiveness of our method.


title: The TimeMachine for Inference on Stochastic Trees

abstract:
  The simulation of genealogical trees backwards in time, from observations up
to the most recent common ancestor (MRCA), is hindered by the fact that, while
approaching the root of the tree, coalescent events become rarer, with a
corresponding increase in computation time. The recently proposed "Time
Machine" tackles this issue by stopping the simulation of the tree before
reaching the MRCA and correcting for the induced bias. We present a
computationally efficient implementation of this approach that exploits
multithreading.


title: Hasse principle for the Chow groups on quadric fibrations

abstract:
  We give a sufficient condition for the injectivity of the global-to-local map
of the relative Chow group of zero-cycles on a quadric fibration of dimension 2
or 3 defined over a number field.


title: The angular momentum dependence of nuclear optical potentials

abstract:
  The nuclear optical model potential (OMP) is generally assumed to be
independent of the orbital angular momentum, $l$, of the interacting nuclei.
Nucleon-nucleus and nucleus-nucleus interactions are customarily $l$
independent in calculations of nuclear elastic scattering and in standard
reaction codes. The evidence for various forms of $l$ dependence of OMPs is
reviewed and the importance of implementing these forms is evaluated. Existing
arguments and evidence for $l$ dependence are reviewed and new arguments and
calculations are introduced. The relationship is examined between (i) $l$
dependence, and, (ii) the undularity (waviness) of $l$-independent potentials
that are $S$-matrix equivalent to $l$-dependent potentials. Such undularity is
a property of the dynamic polarisation potential (DPP) generated by the
coupling to reaction channels, or by coupling to excited states of the target
or projectile nuclei. Various examples, particularly involving weakly bound
projectile nuclei, are presented. Such undularity also occurs in
$l$-independent potentials that have been found in model independent fits to
precise wide angular range elastic scattering angular distributions. Cases of
such phenomenological undularity, for both light and heavy ions, are referenced
and shown to be related to undulatory properties of the dynamic polarisation
potentials (DPPs) arising from channel coupling. Other forms of $l$ dependence,
that could be standard options in direct reaction codes, are noted. Of
particular importance are $l$ dependencies arising from full
antisymmetrization. The case is made that reaction-induced $l$ dependence is a
general property of nucleon-nucleus and nucleus-nucleus interactions and
represents a valid extension of the nuclear optical model.


title:
Integrating genealogical and dynamical modelling to infer escape and
  reversion rates in HIV epitopes

abstract:
  The rates of escape and reversion in response to selection pressure arising
from the host immune system, notably the cytotoxic T-lymphocyte (CTL) response,
are key factors determining the evolution of HIV. Existing methods for
estimating these parameters from cross-sectional population data using ordinary
differential equations (ODE) ignore information about the genealogy of sampled
HIV sequences, which has the potential to cause systematic bias and
over-estimate certainty. Here, we describe an integrated approach, validated
through extensive simulations, which combines genealogical inference and
epidemiological modelling, to estimate rates of CTL escape and reversion in HIV
epitopes. We show that there is substantial uncertainty about rates of viral
escape and reversion from cross-sectional data, which arises from the inherent
stochasticity in the evolutionary process. By application to empirical data, we
find that point estimates of rates from a previously published ODE model and
the integrated approach presented here are often similar, but can also differ
several-fold depending on the structure of the genealogy. The model-based
approach we apply provides a framework for the statistical analysis of escape
and reversion in population data and highlights the need for longitudinal and
denser cross-sectional sampling to enable accurate estimate of these key
parameters.


title: Bulk magnetoelectricity in the hexagonal manganites and ferrites

abstract:
  Improper ferroelectricity (trimerization) in the hexagonal manganites
RMnO$_3$ leads to a network of coupled structural and magnetic vortices that
induce domain wall magnetoelectricity and magnetization neither of which,
however, occurs in the bulk. Here we combined first-principles calculations,
group-theoretic techniques, and microscopic spin models to show how the
trimerization not only induces a polarization but also a bulk magnetization and
bulk magnetoelectric (ME) effect. This results in the existence of a bulk
linear ME vortex structure or a bulk ME coupling such that if direction of
polarization reverses so does magnetization. To measure the predicted ME
vortex, we suggest RMnO$_3$ under large magnetic field. We suggest a family of
materials, the hexagonal RFeO$_3$ ferrites, also display the predicted
phenomena in their ground state.


title: Link overlaps at Criticality and Universality in Ising Spin Glasses

abstract:
  Extensive simulations are made of link and spin overlaps in four and five
dimensional Ising Spin Glasses (ISGs). Moments and moment ratios of the mean
link overlap distributions (the variance, the kurtosis and the skewness) show
clear critical behavior around the ISG ordering temperature. The link overlap
measurements can be used to identify the ISG transition accurately; the link
overlap is often a more efficient tool in this context than the spin overlap
because the link overlap inter-sample variability is much weaker. Once the
transition temperature is accurately established, critical exponents can be
readily estimated by extrapolating measurements made in the thermodynamic limit
regime. The data show that the bimodal and Gaussian spin glass susceptibility
exponents $\gamma$ are different from each other, both in dimension 5 and in
dimension 4. Hence ISG critical exponents are not universal in a given
dimension, but depend on the form of the interaction distribution.


title: New physics in top decay

abstract:
  After a short introduction to effective field theories, most of their
features are illustrated using the top decay. The effects of heavy new physics
on the top decay are computed and the constraints on the coefficients of the
dimension-six operators are derived from the available measurements.


title: Phenomenology of light sterile neutrinos: a brief review

abstract:
  An increasing number of anomalous experimental results are emerging, which
cannot be described within the standard 3-neutrino framework. We present a
concise discussion of the most popular phenomenological interpretation of such
findings, based on a hypothetical flavor conversion phenomenon of the ordinary
"active" neutrinos into new light "sterile" species having mass m ~ O(1) eV.


title: Exploring Cartan gravity with dynamical symmetry breaking

abstract:
  It has been known for some time that General Relativity can be regarded as a
Yang-Mills-type gauge theory in a symmetry broken phase. In this picture the
gravity sector is described by an $SO(1,4)$ or $SO(2,3)$ gauge field
$A^{a}_{\phantom{a}b\mu}$ and Higgs field $V^{a}$ which acts to break the
symmetry down to that of the Lorentz group $SO(1,3)$. This symmetry breaking
mirrors that of electroweak theory. However, a notable difference is that while
the Higgs field $\Phi$ of electroweak theory is taken as a genuine dynamical
field satisfying a Klein-Gordon equation, the gauge independent norm $V^2\equiv
\eta_{ab}V^{a}V^{b}$ of the Higgs-type field $V^a$ is typically regarded as
non-dynamical. Instead, in many treatments $V^a$ does not appear explicitly in
the formalism or is required to satisfy $V^2 = \mathrm{const.} \neq 0$ by means
of a Lagrangian constraint. As an alternative to this we propose a class of
polynomial actions that treat both the gauge connection
$A^{a}_{\phantom{a}b\mu}$ and Higgs field $V^a$ as genuine dynamical fields
with no ad-hoc constraints imposed. The resultant equations of motion consist
of a set of first-order partial differential equations. We show that for
certain actions these equations may be cast in a second-order form,
corresponding to a scalar-tensor model of gravity. One simple choice leads to
the extensively studied Peebles-Ratra rolling quintessence model. Another
choice yields a scalar-tensor symmetry broken phase of the theory with positive
cosmological constant and an effective mass $M$ of the gravitational Higgs
field ensuring the constancy of $V^2$ at low energies and agreement with
empirical data if $M$ is sufficiently large. More general cases are discussed
corresponding to variants of Chern-Simons modified gravity and scalar-Euler
form gravity, each of which yield propagating torsion.


title: A-classification of map-germs via $_V$K-equivalence

abstract:
  The classification of map-germs up to the natural right-left equivalence
(also known as A-equivalence) is often complicated. Certainly it is more
complicated than K-equivalence which is extremely easy to work with because the
associated tangent spaces are not 'mixed' modules as they are in the
A-equivalence case.
  In this paper we use a version of K-equivalence, denoted $_V$K-equivalence,
that is defined using K-equivalences that preserve a variety in the source of
maps to classify maps up to A-equivalence. This is possible through making
clear the connection between the two equivalences - previous work by Damon
mostly focussed on the relation between the codimensions associated to the
maps.
  To demonstrate the power and efficiency of the method we give a
classification of certain A$_e$-codimension 2 maps from $n$-space to
$n+1$-space. The proof using $_V$K-equivalence is considerably shorter - by a
wide margin - than one using A-equivalence directly.


title:
Open Access, library and publisher competition, and the evolution of
  general commerce

abstract:
  Discussions of the economics of scholarly communication are usually devoted
to Open Access, rising journal prices, publisher profits, and boycotts. That
ignores what seems a much more important development in this market.
Publishers, through the oft-reviled "Big Deal" packages, are providing much
greater and more egalitarian access to the journal literature, an approximation
to true Open Access. In the process they are also marginalizing libraries, and
obtaining a greater share of the resources going into scholarly communication.
This is enabling a continuation of publisher profits as well as of what for
decades has been called "unsustainable journal price escalation". It is also
inhibiting the spread of Open Access, and potentially leading to an oligopoly
of publishers controlling distribution through large-scale licensing.
  The "Big Deal" practices are worth studying for several general reasons. The
degree to which publishers succeed in diminishing the role of libraries may be
an indicator of the degree and speed at which universities transform
themselves. More importantly, these "Big Deals" appear to point the way to the
future of the whole economy, where progress is characterized by declining
privacy, increasing price discrimination, increasing opaqueness in pricing,
increasing reliance on low-paid or upaid work of others for profits, and
business models that depend on customer inertia.

categories: cs.DL cs.CY cs.SI math.HO physics.soc-ph


title: FCS of superconducting tunnel junctions in non-equilibrium

abstract:
  We analyse the full counting statistics (FCS) of a superconducting junction
in non-equilibrium in the limit of small interface transparency. In this limit
we treat both supercurrent and multiple Andreev reflections on equal footing
and show how to generalise previous results for both phenomena. Furthermore, we
also allow for different gaps of both superconductors and investigate the
intermediate regime which allows to make contact with previous results on
normal-superconductor heterostructures. We also compare our predictions in this
regime to experimental data.


title:
Nevanlinna theory for meromorphic maps from a closed submanifold of
  $\mathbb{C}^l$ to a compact complex manifold

abstract:
  The purpose of this article is threefold. The first is to construct a
Nevanlina theory for meromorphic mappings from a polydisc to a compact complex
manifold. In particular, we give a simple proof of Lemma on logarithmic
derivative for nonzero meromorphic functions on $\mathbb{C}^l.$ The second is
to improve the definition of the non-integrated defect relation of H. Fujimoto
\cite{F2} and to show two theorems on the new non-integrated defect relation of
meromorphic maps from a closed submanifold of $\mathbb{C}^l$ to a compact
complex manifold. The third is to give a unicity theorem for meromorphic
mappings from a Stein manifold to a compact complex manifold.


title:
Competing states in the SU(3) Heisenberg model on the honeycomb lattice:
  Plaquette valence-bond crystal versus dimerized color-ordered state

abstract:
  Conflicting predictions have been made for the ground state of the SU(3)
Heisenberg model on the honeycomb lattice: Tensor network simulations found a
plaquette order [Zhao et al, Phys. Rev. B 85, 134416 (2012)], where singlets
are formed on hexagons, while linear flavor-wave theory (LFWT) suggested a
dimerized, color ordered state [Lee and Yang, Phys. Rev. B 85, 100402 (2012)].
In this work we show that the former state is the true ground state by a
systematic study with infinite projected-entangled pair states (iPEPS), for
which the accuracy can be systematically controlled by the so-called bond
dimension $D$. Both competing states can be reproduced with iPEPS by using
different unit cell sizes. For small $D$ the dimer state has a lower
variational energy than the plaquette state, however, for large $D$ it is the
latter which becomes energetically favorable. The plaquette formation is also
confirmed by exact diagonalizations and variational Monte Carlo studies,
according to which both the dimerized and plaquette states are non-chiral flux
states.


title: Short lists with short programs in short time - a short proof

abstract:
  Bauwens, Mahklin, Vereshchagin and Zimand [ECCC TR13-007] and Teutsch
[arxiv:1212.6104] have shown that given a string x it is possible to construct
in polynomial time a list containing a short description of it. We simplify
their technique and present a shorter proof of this result.


title: Entanglement negativity and conformal field theory: a Monte Carlo study

abstract:
  We investigate the behavior of the moments of the partially transposed
reduced density matrix \rho^{T_2}_A in critical quantum spin chains. Given
subsystem A as union of two blocks, this is the (matrix) transposed of \rho_A
with respect to the degrees of freedom of one of the two. This is also the main
ingredient for constructing the logarithmic negativity. We provide a new
numerical scheme for calculating efficiently all the moments of \rho_A^{T_2}
using classical Monte Carlo simulations. In particular we study several
combinations of the moments which are scale invariant at a critical point.
Their behavior is fully characterized in both the critical Ising and the
anisotropic Heisenberg XXZ chains. For two adjacent blocks we find, in both
models, full agreement with recent CFT calculations. For disjoint ones, in the
Ising chain finite size corrections are non negligible. We demonstrate that
their exponent is the same governing the unusual scaling corrections of the
mutual information between the two blocks. Monte Carlo data fully match the
theoretical CFT prediction only in the asymptotic limit of infinite intervals.
Oppositely, in the Heisenberg chain scaling corrections are smaller and,
already at finite (moderately large) block sizes, Monte Carlo data are in
excellent agreement with the asymptotic CFT result.

categories: cond-mat.stat-mech cond-mat.str-el hep-th quant-ph


title: Design-Efficiency in Security

abstract:
  In this document, we present our applied results on balancing security and
performance using a running example, which is based on sensor networks. These
results are forming a basis for a new approach to balance security and
performance, and therefore provide design-efficiency of key updates.
  We employ probabilistic model checking approach and present our modelling and
analysis study using PRISM model checker.


title: BSM constraints from EW measurements

abstract:
  We investigate the impact of heavy new physics on W bosons productions at
hadron colliders using an effective field theory. After listing all the
relevant dimension-six operators, their effects are computed taking into
account LEP constraints. Additionally, the effective approach is compared to
anomalous couplings regarding several issues like unitarity.


title: Entanglement negativity in the critical Ising chain

abstract:
  We study the scaling of the traces of the integer powers of the partially
transposed reduced density matrix and of the entanglement negativity for two
spin blocks as function of their length and separation in the critical Ising
chain. For two adjacent blocks, we show that tensor network calculations agree
with universal conformal field theory (CFT) predictions. In the case of two
disjoint blocks the CFT predictions are recovered only after taking into
account the finite size corrections induced by the finite length of the blocks.


title: A decomposition theorem in II_1-factors

abstract:
  Building on results of Haagerup and Schultz, we decompose an arbitrary
operator in a diffuse, finite von Neumann algebra into the sum of a normal
operator and an s.o.t.-quasinilpotent operator. We also prove an analogue of
Weyl's inequality relating eigenvalues and singular values for operators in a
diffuse, finite von Neumann algebra.


title: Quantum Metrology in Open Systems: Dissipative Cram\'{e}r-Rao Bound

abstract:
  Estimation of parameters is a pivotal task throughout science and technology.
Quantum Cram\'{e}r-Rao bound provides a fundamental limit of precision allowed
to achieve under quantum theory. For closed quantum systems, it has been shown
how the estimation precision depends on the underlying dynamics. Here, we
propose a general formulation for metrology scenarios in open quantum systems,
aiming to relate the precision more directly to properties of the underlying
dynamics. This feature may be employed to enhance an estimation precision,
e.g., by quantum control techniques. Specifically, we derive a Cram\'{e}r-Rao
bound for a fairly large class of open system dynamics, which is governed by a
(time-dependent) dynamical semi-group map. We illustrate the utility of this
scenario through three examples.


title: On new types of integrable 4-wave interactions

abstract:
  We start with a Riemann-Hilbert Problems (RHP) with canonical normalization
whose sewing functions depends on two or more additional variables. Using
Zakharov-Shabat theorem we are able to construct a family of ordinary
differential operators for which the solution of the RHP is a common
fundamental analytic solution. This family of operators obviously commute
provided their coefficients satisfy certain nonlinear evolution equations. Thus
we are able to construct new classes of integrable nonlinear evolution
equations. We illustrate the method with an example of a new type 4-wave
interactions. Its Lax pair consists of operators which are both quadratic in
the spectral parameter $\lambda$ and take values in the so(5) algebra.


title: Photo-fission of 232Th and 238U at intermediate energies

abstract:
  In this work we present an analysis of the yields of fission fragments
induced by bremsstrahlung photons with endpoint energies of 50 and 3500 MeV on
232Th and 238U targets using the simulation code CRISP. A multimodal fission
option was added to this code and an extension of the calculation to the
properties of the fission products is presented. By dividing the fissioning
nuclei according to their fissionability, an approach is introduced which
accounts for the contribution of symmetric and asymmetric fission. By adopting
this procedure, it was possible to calculate the main parameters for the
fission fragment charge distribution such as the most probable charge for a
given fission product mass chain and its corresponding width parameter. Also,
it was possible to reproduce features of fragment mass distribution and
evaluate the fissility of fissioning nuclei for photon-induced fission of 232Th
and 238U.


title: Crystallization in Glassy Suspensions of Hard Ellipsoids

abstract:
  We have carried out computer simulations of overcompressed suspensions of
hard monodisperse ellipsoids and observed their crystallization dynamics. The
system was compressed very rapidly in order to reach the regime of slow,
glass-like dynamics. We find that, although particle dynamics become
sub-diffusive and the intermediate scattering function clearly develops a
shoulder, crystallization proceeds via the usual scenario: nucleation and
growth for small supersaturations, spinodal decomposition for large
supersaturations.
  In particular, we compared the mobility of the particles in the regions where
crystallization set in with the mobility in the rest of the system. We did not
find any signature in the dynamics of the melt that pointed towards the
imminent crystallization events.


title: Photon Signals from Quarkyonic Matter

abstract:
  We calculate the Bremsstrahlung photon spectrum emitted from dynamically
evolving quarkyonic matter, and compare this spectrum with that of a high
chemical potential quark-gluon plasma as well as to a hadron gas. We find that
the transverse momentum distribution and the harmonic coefficient is markedly
different in the three cases. The transverse momentum distribution of
quarkyonic matter can be fit with an exponential, but is markedly steeper than
the distribution expected for the quark-gluon plasma or a hadron gas, even at
the lower temperatures expected in the critical point region. The quarkyonic
elliptic flow coefficient fluctuates randomly from event to event, and within
the same event at different transverse momenta. The latter effect, which can be
explained by the shape of quark wavefunctions within quarkyonic matter, might
be considered as a quarkyonic matter signature, provided initial temperature is
low enough that the quarkyonic regime dominates over deconfinement effects, and
the reaction-plane flow can be separated from the fluctuating component.


title: Topology of Complex Bridges inside Vibrated Dry Granular Media

abstract:
  After some communications (EMAIL EXCHANGE) with the co-authors, this article
has been withdrawn (for appropriate reason, please refer to the comments
section).


title:
The Detection of Interstellar Ethanimine (CH3CHNH) from Observations
  taken during the GBT PRIMOS Survey

abstract:
  We have performed reaction product screening measurements using broadband
rotational spectroscopy to identify rotational transition matches between
laboratory spectra and the Green Bank Telescope PRIMOS radio astronomy survey
spectra in Sagittarius B2 North (Sgr B2(N)). The broadband rotational spectrum
of molecules created in an electrical discharge of CH3CN and H2S contained
several frequency matches to unidentified features in the PRIMOS survey that
did not have molecular assignments based on standard radio astronomy spectral
catalogs. Several of these transitions are assigned to the E- and Z-isomers of
ethanimine. Global fits of the rotational spectra of these isomers in the range
of 8 to 130 GHz have been performed for both isomers using previously published
mm-wave spectroscopy measurements and the microwave measurements of the current
study. Possible interstellar chemistry formation routes for E-ethanimine and
Z-ethanimine are discussed. The detection of ethanimine is significant because
of its possible role in the formation of alanine - one of the twenty amino
acids in the genetic code.


title: Tuning universality far from equilibrium

abstract:
  Possible universal dynamics of a many-body system far from thermal
equilibrium are explored. A focus is set on meta-stable non-thermal states
exhibiting critical properties such as self-similarity and independence of the
details of how the respective state has been reached. It is proposed that
universal dynamics far from equilibrium can be tuned to exhibit a dynamical
phase transition where these critical properties change qualitatively. This is
demonstrated for the case of a superfluid two-component Bose gas exhibiting
different types of long-lived but non-thermal critical order. Scaling exponents
controlled by the ratio of experimentally tuneable coupling parameters offer
themselves as natural smoking guns. The results shed light on the wealth of
universal phenomena expected to exist in the far-from-equilibrium realm.

categories: cond-mat.quant-gas cond-mat.stat-mech hep-ph quant-ph


title: Large Scale Distributed Acoustic Modeling With Back-off N-grams

abstract:
  The paper revives an older approach to acoustic modeling that borrows from
n-gram language modeling in an attempt to scale up both the amount of training
data and model size (as measured by the number of parameters in the model), to
approximately 100 times larger than current sizes used in automatic speech
recognition. In such a data-rich setting, we can expand the phonetic context
significantly beyond triphones, as well as increase the number of Gaussian
mixture components for the context-dependent states that allow it. We have
experimented with contexts that span seven or more context-independent phones,
and up to 620 mixture components per state. Dealing with unseen phonetic
contexts is accomplished using the familiar back-off technique used in language
modeling due to implementation simplicity. The back-off acoustic model is
estimated, stored and served using MapReduce distributed computing
infrastructure.
  Speech recognition experiments are carried out in an N-best list rescoring
framework for Google Voice Search. Training big models on large amounts of data
proves to be an effective way to increase the accuracy of a state-of-the-art
automatic speech recognition system. We use 87,000 hours of training data
(speech along with transcription) obtained by filtering utterances in Voice
Search logs on automatic speech recognition confidence. Models ranging in size
between 20--40 million Gaussians are estimated using maximum likelihood
training. They achieve relative reductions in word-error-rate of 11% and 6%
when combined with first-pass models trained using maximum likelihood, and
boosted maximum mutual information, respectively. Increasing the context size
beyond five phones (quinphones) does not help.


title: On the upper semi-continuity of HSL numbers

abstract:
  Let $B$ be an affine Cohen-Macaulay algebra over a field of characteristic
$p$. For every prime ideal $\mathfrak{p}\subset B$, let $\text{H}_\mathfrak{p}$
denote $H^{\dim B_\mathfrak{p}}_{\mathfrak{p} B_\mathfrak{p}}\left(
\widehat{B_\mathfrak{p}} \right)$. Each such $\text{H}_\mathfrak{p}$ is an
Artinian module endowed with a natural Frobenius map $\Theta$ and if
$\text{Nil}(\text{H}_\mathfrak{p})$ denotes the set of all elements in
$\text{H}_\mathfrak{p}$ killed by some power of $\Theta$ then a theorem by
Hartshorne-Speiser and Lyubeznik shows that there exists an $e\geq 0$ such that
$\Theta^e \text{Nil}(\text{H}_\mathfrak{p})=0$. The smallest such $e$ is the
HSL-number of $\text{H}_\mathfrak{p}$ which we denote
$\text{HSL}(\text{H}_\mathfrak{p})$. The main theorem in this paper shows that
for all $e>0$, the sets $\{ \mathfrak{p}\in\text{Spec} (B) \,|\,
\text{HSL}(\text{H}_\mathfrak{p}) < e \}$ are Zariski open, hence HSL is upper
semi-continuous. An application of this result gives a global test exponent for
the calculation of Frobenius closures of parameter ideals in Cohen-Macaulay
rings.


title: Lattice Boltzmann model for ultra-relativistic flows

abstract:
  We develop a relativistic lattice Boltzmann model capable of describing
relativistic fluid dynamics at ultra-high velocities, with Lorentz factors up
to $\gamma \sim 10$. To this purpose, we first build a new lattice kinetic
scheme by expanding the Maxwell-J\"uttner distribution function in an
orthogonal basis of polynomials and applying an appropriate quadrature,
providing the discrete versions of the relativistic Boltzmann equation and the
equilibrium distribution. To achieve ultra-high velocities, we include a flux
limiter scheme, and introduce the bulk viscosity by a suitable extension of the
discrete relativistic Boltzmann equation. The model is validated by performing
simulations of shock waves in viscous quark-gluon plasmas and comparing with
existing models, finding very good agreement. To the best of our knowledge, we
for the first time successfully simulate viscous shock waves in the highly
relativistic regime. Moreover, we show that our model can also be used for
near-inviscid flows even at very high velocities. Finally, as an astrophysical
application, we simulate a relativistic shock wave, generated by, say, a
supernova explosion, colliding with a massive interstellar cloud, e.g.
molecular gas.

categories: astro-ph.HE astro-ph.IM cond-mat.stat-mech physics.comp-ph