title: Tunneling spectra simulation of interacting Majorana wires

abstract:
  Recent tunneling experiments on InSb hybrid superconductor-semiconductor
devices have provided hope for a stabilization of Majorana edge modes in a
spin-orbit quantum wire subject to a magnetic field and superconducting
proximity effect. Connecting the experimental scenario with a microscopic
description poses challenges of different kind, such as accounting for the
effect of interactions on the tunneling properties of the wire. We develop a
density matrix renormalization group (DMRG) analysis of the tunneling spectra
of interacting Majorana chains, which we explicate for the Kitaev chain model.
Our DMRG approach allows us to calculate the spectral function down to zero
frequency, where we analyze how the Majorana zero-bias peak is affected by
interactions. From the study of topological phase transitions between the
topological and trivial superconducting phase in the wire, we argue that the
bulk gap closure generically affects both the proximity peaks and the Majorana
peak, which should be observable in the transport signal.


title: Optimal Results on ITRM-recognizability

abstract:
  Exploring further the properties of ITRM-recognizable reals, we provide a
detailed analysis of recognizable reals and their distribution in G\"odels
constructible universe L. In particular, we show that, for unresetting infinite
time register machines, the recognizable reals coincide with the computable
reals and that, for ITRMs, unrecognizables are generated at every index bigger
than the first limit of admissibles. We show that a real r is recognizable iff
it is $\Sigma_{1}$-definable over $L_{\omega_{\omega}^{CK,r}}$, that $r\in
L_{\omega_{\omega}^{CK,r}}$ for every recognizable real $r$ and that either all
or no real generated over an index stage $L_{\gamma}$ are recognizable.


title: Validation of Geant4-based Radioactive Decay Simulation

abstract:
  Radioactive decays are of concern in a wide variety of applications using
Monte-Carlo simulations. In order to properly estimate the quality of such
simulations, knowledge of the accuracy of the decay simulation is required. We
present a validation of the original Geant4 Radioactive Decay Module, which
uses a per-decay sampling approach, and of an extended package for Geant4-based
simulation of radioactive decays, which, in addition to being able to use a
refactored per-decay sampling, is capable of using a statistical sampling
approach. The validation is based on measurements of calibration isotope
sources using a high purity Germanium (HPGe) detector; no calibration of the
simulation is performed. For the considered validation experiment equivalent
simulation accuracy can be achieved with per-decay and statistical sampling.


title:
Measurement of the $pn \to pp\pi^0\pi^-$ Reaction in Search for the
  Recently Observed Resonance Structure in $d\pi^0\pi^0$ and $d\pi^+\pi^-$
  systems

abstract:
  Exclusive measurements of the quasi-free $pn \to pp\pi^0\pi^-$ reaction have
been performed by means of $pd$ collisions at $T_p$ = 1.2 GeV using the WASA
detector setup at COSY. Total and differential cross sections have been
obtained covering the energy region $\sqrt s$ = (2.35 - 2.46) GeV, which
includes the region of the ABC effect and its associated resonance structure.
No ABC effect, {\it i.e.} low-mass enhancement is found in the
$\pi^0\pi^-$-invariant mass spectrum -- in agreement with the constraint from
Bose statistics that the isovector pion pair can not be in relative s-wave. At
the upper end of the covered energy region $t$-channel processes for Roper,
$\Delta(1600)$ and $\Delta\Delta$ excitations provide a reasonable description
of the data, but at low energies the measured cross sections are much larger
than predicted by such processes. Adding a resonance amplitude for the
resonance at $m$=~2.37 GeV with $\Gamma$ =~70 MeV and $I(J^P)=~0(3^+)$ observed
recently in $pn \to d\pi^0\pi^0$ and $pn \to d\pi^+\pi^-$ reactions leads to an
agreement with the data also at low energies.


title:
Two-point correlation function of density perturbations in a large void
  universe

abstract:
  We study the two-point correlation function of density perturbations in a
spherically symmetric void universe model which does not employ the Copernican
principle. First we solve perturbation equations in the inhomogeneous universe
model and obtain density fluctuations by using a method of non-linear
perturbation theory which was adopted in our previous paper. From the obtained
solutions, we calculate the two-point correlation function and show that it has
a local anisotropy at the off-center position differently from those in
homogeneous and isotropic universes. This anisotropy is caused by the tidal
force in the off-center region of the spherical void. Since no tidal force
exists in homogeneous and isotropic universes, we may test the inhomogeneous
universe by observing statistical distortion of the two-point galaxy
correlation function.


title: Dynamics of Nano-Confined Water under Pressure

abstract:
  We report a study of the effects of pressure on the diffusivity of water
molecules confined in single- wall carbon nanotubes (SWNT) with average mean
pore diameter of 16 Angstroms. The measurements were carried out using
high-resolution neutron scattering, over the temperature range 220 < T < 260 K,
and at two pressure conditions: ambient and elevated pressure. The high
pressure data were collected at constant volume on cooling, with P varying from
1.92 kbar at temperature T = 260 K to 1.85 kbar at T = 220 K. Analysis of the
observed dynamic structure factor S(Q, E) reveals the presence of two
relaxation processes, a faster diffusion component (FC) associated with the
motion of "caged" or restricted molecules, and a slower component arising from
the free water molecules diffusing within the SWNT matrix. While the
temperature dependence of the slow relaxation time exhibits a
Vogel-Fulcher-Tammann law and is non-Arrhenius in nature, the faster component
follows an Arrhenius exponential law at both pressure conditions. The
application of pressure remarkably slows down the overall molecular dynamics,
in agreement with previous observations, but most notably affects the slow
relaxation. The faster relaxation shows marginal or no change with pressure
within the experimental conditions.


title:
Mathematical treatment of the homogeneous Boltzmann equation for
  Maxwellian molecules in the presence of singular kernels

abstract:
  This paper proves the existence of weak solutions to the spatially
homogeneous Boltzmann equation for Maxwellian molecules, when the initial data
are chosen from the space of all Borel probability measures on R^3 with finite
second moments and the (angular) collision kernel satisfies a very weak cutoff
condition. Conservation of momentum and energy is also proved for these weak
solutions, without resorting to any boundedness of the entropy.


title: A complexity theorem for the Novelli-Pak-Stoyanovskii algorithm

abstract:
  We describe two aspects of the behaviour of entries of Young tableaux during
the application of the Novelli-Pak-Stoyanovskii algorithm. We derive two
theorems which both contain a generalized version of a conjecture by
Krattenthaler and M\"uller concerning the complexity of the
Novelli-Pak-Stoyanovskii algorithm as corollary.


title:
Dynamical Coulomb Blockade in an interacting 1D system coupled to an
  arbitrary environment

abstract:
  We study the out-of-equilibrium transport in a Tomonaga-Luttinger liquid
containing a weak or a tunneling barrier coupled to an arbitrary
electromagnetic environment. This applies as well to a coherent one-channel
non-interacting conductor with a transmission coefficient close to one or to
zero. We derive formal expressions for the current and finite-frequency (FF)
noise at arbitrary voltages, temperatures and frequency-dependent impedance
$Z(\omega)$ in the regimes of weak and strong backscattering. We show that
these two regimes are no longer related by duality at finite frequency. We then
carry explicit computations of the nonlinear conductance and FF noise when
$Z(\omega)$ describes an harmonic oscillator such as a LC circuit or a cavity.


title: Control excitation and coherent transfer in a dimer

abstract:
  In this article, the processes of energy absorption and coherent transfer in
a dimer is studied. The dimer includes two two-level pigments --- donor and
acceptor, where donor is assumed being excited by a control pulse in the time
domain. We investigate the dynamics of probability that the acceptor is in the
excited state and the total efficiency of energy absorption and transfer under
different temporal shape of control pulse. Quantum concurrence of the dimer is
also discussed.


title:
Holographic $s$-wave condensation and Meissner-like effect in
  Gauss-Bonnet gravity with various non-linear corrections

abstract:
  In this paper we have studied the onset of holographic $s$-wave condensate in
the $(4+1)$ dimensional planar Gauss-Bonnet-AdS black hole background with
several non-linear corrections to the gauge field. In the probe limit,
performing explicit analytic computations, with and without magnetic field, we
found that these higher order corrections indeed affect various quantities
characterising the holographic superconductors. Also, performing a comparative
study of the two non-linear electrodynamics it has been shown that the
exponential electrodynamics has stronger effects on the formation of the scalar
hair. We observe that our results agree well with those obtained numerically
[Z. Zhao et. al., Nucl. Phys. B 871 [FS] (2013) 98].


title:
Renormalization group analysis of the singularity structure of effective
  potentials

abstract:
  Using the renormalization group techniques it was previously shown that the
perturbative effective potential in the $\mathcal{O}(N)$ symmetric $\phi^4$
theory, massless scalar electrodynamics as well as in the conformal limit of
the standard model can be uniquely determined in terms of the known MS scheme
renormalization group functions. Furthermore, re-summation of the leading order
corrections plus portions of these higher order contributions to the effective
potential in the $\mathcal{O}(N)$ symmetric $\phi^4$ theory shows a peculiar
shift in the usual "Landau singularity" apparent in the individual leading
order corrections. In this work, we have further investigated this shift by
extending the result for theories having multiple couplings. We have shown that
the singularity structure of the effective potential as seen by summing up
portions of the $V_{N^{P+n}LL}$ for any finite $P$ is altered as expected when
these perturbative contributions are summed to all orders but more
significantly we found that this shift in the singularity is completely
determined by the one and two loop beta functions only. We argue that this is a
general result which applies to the conformally invariant standard model.


title:
Localizing vector optimization problems with application to welfare
  economics

abstract:
  In the present paper, the Polyak's principle, concerning convexity of the
images of small balls through C1,1 mappings, is employed in the study of vector
optimization problems. This leads to extend to such a context achievements of
local programming, an approach to nonlinear optimization, due to B.T. Polyak,
which consists in exploiting the benefits of the convex local behaviour of
certain nonconvex problems. In doing so, solution existence and optimality
conditions are established for localizations of vector optimization problems,
whose data satisfy proper assumptions. Such results are subsequently applied in
the analysis of welfare economics, in the case of an exchange economy model
with infinite-dimensional commodity space. In such a setting, the localization
of an economy yields existence of Pareto optimal allocations, which, under
certain additional assumptions, lead to competitive equilibria.


title: How well do we know the Halo Mass Function?

abstract:
  The parameters governing the standard \Lambda Cold Dark Matter cosmological
model have been constrained with unprecedented accuracy by precise measurements
of the cosmic microwave background by the Wilkinson Microwave Anisotropy Probe
(WMAP) and Planck satellites. Each new data release has refined further our
knowledge of quantities -- such as the matter density parameter \Omega_M --
that are imprinted on the dark matter halo mass function (HMF), a powerful
probe of dark matter and dark energy models. In this letter we trace how
changes in the cosmological parameters over the last decade have influenced
uncertainty in our knowledge of the HMF. We show that this uncertainty has
reduced significantly since the 3rd WMAP data release, but the rate of this
reduction is slowing. This is limited by uncertainty in the normalisation
\sigma_8, whose influence is most pronounced at the high mass end of the mass
function. Interestingly, we find that the accuracy with which we can constrain
the HMF in terms of the cosmological parameters has now reached the point at
which it is comparable to the scatter in HMF fitting functions. This suggests
that the power of the HMF as a precision probe of dark matter and dark energy
hinges on more accurate determination of the theoretical HMF. Finally, we
assess prospects of using the HMF to differentiate between Cold and Warm Dark
Matter models based on ongoing improvements in measurements of \Omega_M, and we
comment briefly on optimal survey strategies for constraining dark matter and
dark energy models using the HMF.


title:
Phase diagram and critical behavior of the random ferromagnet
  $Ga_{1-x}Mn_xN$

abstract:
  Molecular beam epitaxy has been employed to obtain Ga1-xMnxN films with x up
to 10% and Curie temperatures T_C up to 13 K. The magnitudes of T_C and their
dependence on x, T_C(x) ~ x^m, where m = 2.2 +/- 0.2 are quantitatively
described by a tight binding model of superexchange interactions and Monte
Carlo simulations of T_C. The critical behavior of this dilute magnetic
insulator shows strong deviations from the magnetically clean case (x = 1), in
particular, (i) an apparent breakdown of the Harris criterion; (ii) a
non-monotonic crossover in the values of the susceptibility critical exponent
gamma_eff between the high temperature and critical regimes, and (iii) a
smearing of the critical region, which can be explained either by the Griffiths
effects or by macroscopic inhomogeneities in the spin distribution with a
variance Delta x = (0.2 +/- 0.1)%.


title: Fake Run-Time Selection of Template Arguments in C++

abstract:
  C++ does not support run-time resolution of template type arguments. To
circumvent this restriction, we can instantiate a template for all possible
combinations of type arguments at compile time and then select the proper
instance at run time by evaluation of some provided conditions. However, for
templates with multiple type parameters such a solution may easily result in a
branching code bloat. We present a template metaprogramming algorithm called
for_id that allows the user to select the proper template instance at run time
with theoretical minimum sustained complexity of the branching code.


title:
Rational extensions of the quantum harmonic oscillator and exceptional
  Hermite polynomials

abstract:
  We prove that every rational extension of the quantum harmonic oscillator
that is exactly solvable by polynomials is monodromy free, and therefore can be
obtained by applying a finite number of state-deleting Darboux transformations
on the harmonic oscillator. Equivalently, every exceptional orthogonal
polynomial system of Hermite type can be obtained by applying a Darboux-Crum
transformation to the classical Hermite polynomials. Exceptional Hermite
polynomial systems only exist for even codimension 2m, and they are indexed by
the partitions \lambda of m. We provide explicit expressions for their
corresponding orthogonality weights and differential operators and a separate
proof of their completeness. Exceptional Hermite polynomials satisfy a 2l+3
recurrence relation where l is the length of the partition \lambda. Explicit
expressions for such recurrence relations are given.

categories: math-ph math.CA math.MP nlin.SI quant-ph


title: The 2-category theory of quasi-categories

abstract:
  In this paper we redevelop the foundations of the category theory of
quasi-categories (also called infinity-categories) using 2-category theory. We
show that Joyal's strict 2-category of quasi-categories admits certain weak
2-limits, among them weak comma objects. We use these comma quasi-categories to
encode universal properties relevant to limits, colimits, and adjunctions and
prove the expected theorems relating these notions. These universal properties
have an alternate form as absolute lifting diagrams in the 2-category, which we
show are determined pointwise by the existence of certain initial or terminal
vertices, allowing for the easy production of examples.
  All the quasi-categorical notions introduced here are equivalent to the
established ones but our proofs are independent and more "formal". In
particular, these results generalise immediately to model categories enriched
over quasi-categories.


title: Social Discounting and the Long Rate of Interest

abstract:
  The well-known theorem of Dybvig, Ingersoll and Ross shows that the long
zero-coupon rate can never fall. This result, which, although undoubtedly
correct, has been regarded by many as surprising, stems from the implicit
assumption that the long-term discount function has an exponential tail. We
revisit the problem in the setting of modern interest rate theory, and show
that if the long "simple" interest rate (or Libor rate) is finite, then this
rate (unlike the zero-coupon rate) acts viably as a state variable, the value
of which can fluctuate randomly in line with other economic indicators. New
interest rate models are constructed, under this hypothesis and certain
generalizations thereof, that illustrate explicitly the good asymptotic
behaviour of the resulting discount bond systems. The conditions necessary for
the existence of such "hyperbolic" and "generalized hyperbolic" long rates are
those of so-called social discounting, which allow for long-term cash flows to
be treated as broadly "just as important" as those of the short or medium term.
As a consequence, we are able to provide a consistent arbitrage-free valuation
framework for the cost-benefit analysis and risk management of long-term social
projects, such as those associated with sustainable energy, resource
conservation, and climate change.


title: Non-Abelian Chern-Simons-Higgs vortices with a quartic potential

abstract:
  We have constructed numerically non-Abelian vortices in an SU(2)
Chern-Simons-Higgs theory with a quartic Higgs potential. We have analyzed
these solutions in detail by means of improved numerical codes and found some
unexpected features we did not find when a sixth-order Higgs potential was
used. The generic non-Abelian solutions have been generated by using their
corresponding Abelian counterparts as initial guess. Typically, the energy of
the non-Abelian solutions is lower than that of the corresponding Abelian one
(except in certain regions of the parameter space). Regarding the angular
momentum, the Abelian solutions possess the maximal value, although there exist
non-Abelian solutions which reach that maximal value too. In order to classify
the solutions it is useful to consider the non-Abelian solutions with
asymptotically vanishing $A_t$ component of the gauge potential, which may be
labelled by an integer number $m$. For vortex number $n=3$ and above, we have
found uniqueness violation: two different non-Abelian solutions with all the
global charges equal. Finally, we have investigated the limit of infinity Higgs
self-coupling parameter and found a piecewise Regge-like relation between the
energy and the angular momentum.


title: Scaling in the Aging Dynamics of the Site-diluted Ising Model

abstract:
  We study numerically the phase-ordering kinetics of the two-dimensional
site-diluted Ising model. The data can be interpreted in a framework motivated
by renormalization-group concepts. Apart from the usual fixed point of the
non-diluted system, there exist two disorder fixed points, characterized by
logarithmic and power-law growth of the ordered domains. This structure gives
rise to a rich scaling behavior, with an interesting crossover due to the
competition between fixed points, and violation of superuniversality.


title:
Arabidopsis plants perform arithmetic division to prevent starvation at
  night

abstract:
  Photosynthetic starch reserves that accumulate in Arabidopsis leaves during
the day decrease approximately linearly with time at night to support
metabolism and growth. We find that the rate of decrease is adjusted to
accommodate variation in the time of onset of darkness and starch content, such
that reserves last almost precisely until dawn. Generation of these dynamics
therefore requires an arithmetic division computation between the starch
content and expected time to dawn. We introduce two novel chemical kinetic
models capable of implementing analog arithmetic division. Predictions from the
models are successfully tested in plants perturbed by a night-time light period
or by mutations in starch degradation pathways. Our experiments indicate which
components of the starch degradation apparatus may be important for appropriate
arithmetic division. Our results are potentially relevant for any biological
system dependent on a food reserve for survival over a predictable time period.


title: On Closed Graphs I

abstract:
  A graph is closed when its vertices have a labeling by [n] with a certain
property first discovered in the study of binomial edge ideals. In this
article, we prove that a connected graph has a closed labeling if and only if
it is chordal, claw-free, and has a property we call narrow, which holds when
every vertex is distance at most one from all longest shortest paths of the
graph.


title:
Vakhitov-Kolokolov and energy vanishing conditions for linear
  instability of solitary waves in models of classical self-interacting spinor
  fields

abstract:
  We study the linear stability of localized modes in self-interacting spinor
fields, analyzing the spectrum of the operator corresponding to linearization
at solitary waves. Following the generalization of the Vakhitov--Kolokolov
approach, we show that the bifurcation of real eigenvalues from the origin is
completely characterized by the Vakhitov--Kolokolov condition $dQ/d\omega=0$
and by the vanishing of the energy functional. We give the numerical data on
the linear stability in the generalized Gross--Neveu model and the generalized
massive Thirring model in the charge-subcritical, critical, and supercritical
cases, showing the agreement with the Vakhitov--Kolokolov and the energy
vanishing conditions.


title: Fine-Grained Visual Classification of Aircraft

abstract:
  This paper introduces FGVC-Aircraft, a new dataset containing 10,000 images
of aircraft spanning 100 aircraft models, organised in a three-level hierarchy.
At the finer level, differences between models are often subtle but always
visually measurable, making visual recognition challenging but possible. A
benchmark is obtained by defining corresponding classification tasks and
evaluation protocols, and baseline results are presented. The construction of
this dataset was made possible by the work of aircraft enthusiasts, a strategy
that can extend to the study of number of other object classes. Compared to the
domains usually considered in fine-grained visual classification (FGVC), for
example animals, aircraft are rigid and hence less deformable. They, however,
present other interesting modes of variation, including purpose, size,
designation, structure, historical style, and branding.


title:
On the continuity of lyapunov exponents of random walks in random
  potentials

abstract:
  We consider a simple random walk in an i.i.d. non-negative potential on the
d-dimensional integer lattice, $d\geq 3$. We study the quenched Lyapunov
exponents, and present a probabilistic proof of its continuity when the
potentials converge in distribution.


title:
Photometry of supernovae in an image series : methods and application to
  the Supernova Legacy Survey (SNLS)

abstract:
  We present a technique to measure lightcurves of time-variable point sources
on a spatially structured background from imaging data. The technique was
developed to measure light curves of SNLS supernovae in order to infer their
distances. This photometry technique performs simultaneous PSF photometry at
the same sky position on an image series. We describe two implementations of
the method: one that resamples images before measuring fluxes, and one which
does not. In both instances, we sketch the key algorithms involved and present
the validation using semi-artificial sources introduced in real images in order
to assess the accuracy of the supernova flux measurements relative to that of
surrounding stars. We describe the methods required to anchor these PSF fluxes
to calibrated aperture catalogs, in order to derive SN magnitudes. We find a
marginally significant bias of 2 mmag of the after-resampling method, and no
bias at the mmag accuracy for the non-resampling method. Given surrounding star
magnitudes, we determine the systematic uncertainty of SN magnitudes to be less
than 1.5 mmag, which represents about one third of the current photometric
calibration uncertainty affecting SN measurements. The SN photometry delivers
several by-products: bright star PSF flux mea- surements which have a
repeatability of about 0.6%, as for aperture measurements; we measure relative
astrometric positions with a noise floor of 2.4 mas for a single-image bright
star measurement; we show that in all bands of the MegaCam instrument, stars
exhibit a profile linearly broadening with flux by about 0.5% over the whole
brightness range.


title: Asymptotic Properties of Fibonacci Cubes and Lucas Cube

abstract:
  It is proved that the asymptotic average eccentricity and the asymptotic
average degree of Fibonacci cubes and Lucas cubes are $(5+\sqrt 5)/10$ and
$(5-\sqrt 5)/5$, respectively. A new labeling of the leaves of Fibonacci trees
is introduced and proved that the eccentricity of a vertex of a given Fibonacci
cube is equal to the depth of the associated leaf in the corresponding
Fibonacci tree. Hypercube density is also introduced and studied. The hypercube
density of both Fibonacci cubes and Lucas cubes is shown to be $(1-1/\sqrt
5)/\log_2\varphi$, where $\varphi$ is the golden ratio, and the Cartesian
product of graphs is used to construct families of graphs with a fixed,
non-zero hypercube density. It is also proved that the limit normed sum of
ratios of Fibonacci words and Lucas words with fixed coordinate 0 and 1,
respectively, is $\varphi^2$.


title: Fragmentation of electric currents in the solar corona by plasma flows

abstract:
  We consider a magnetic configuration consisting of an arcade structure and a
detached plasmoid, resulting from a magnetic reconnection process, as is
typically found in connection with solar flares. We study spontaneous current
fragmentation caused by shear and vortex plasma flows. An exact analytical
transformation method was applied to calculate self-consistent solutions of the
nonlinear stationary MHD equations. The assumption of incompressible
field-aligned flows implies that both the Alfven Mach number and the mass
density are constant on field lines. We first calculated nonlinear MHS
equilibria with the help of the Liouville method, emulating the scenario of a
solar eruptive flare configuration with plasmoids and flare arcade. Then a Mach
number profile was constructed that describes the upflow along the open
magnetic field lines and implements a vortex flow inside the plasmoid. This
Mach number profile was used to map the MHS equilibrium to the stationary one.
We find that current fragmentation takes place at different locations within
our configuration. Steep gradients of the Alfven Mach number are required,
implying the strong influence of shear flows on current amplification and
filamentation of the MHS current sheets. Crescent- or ring-like structures
appear along the outer separatrix, butterfly structures between the upper and
lower plasmoids, and strong current peaks close the lower boundary. Impressing
an intrinsic small-scale structure on the upper plasmoid results in strong
fragmentation of the plasmoid. Hence fragmentation of current sheets and
plasmoids is an inherent property of MHD theory. Transformations from MHS into
MHD steady-states deliver fine-structures needed for plasma heating and
acceleration of particles and bulk plasma flows in dissipative events that are
typically connected to magnetic reconnection processes in flares and coronal
mass ejections.


title: Cryptocat: Adopting Accessibility and Ease of Use as Security Properties

abstract:
  Cryptocat is a Free and Open Source Software (FL/OSS) browser extension that
makes use of web technologies in order to provide easy to use, accessible,
encrypted instant messaging to the general public. We aim to investigate how to
best leverage the accessibility and portability offered by web technologies in
order to allow encrypted instant messaging an opportunity to better permeate on
a social level. We have found that encrypted communications, while in many
cases technically well-implemented, suffer from a lack of usage due to their
being unappealing and inaccessible to the "average end-user". Our position is
that accessibility and ease of use must be treated as security properties. Even
if a cryptographic system is technically highly qualified, securing user
privacy is not achieved without addressing the problem of accessibility. Our
goal is to investigate the feasibility of implementing cryptographic systems in
highly accessible mediums, and to address the technical and social challenges
of making encrypted instant messaging accessible and portable.


title: Anti-correlation for Conductance Fluctuations in Chaotic Quantum Dots

abstract:
  We investigate the correlation functions of mesoscopic electronic transport
in open chaotic quantum dots with finite tunnel barriers in the crossover
between Wigner-Dyson ensembles. Using an analytical stub formalism, we show the
emergence of a depletion/amplification of conductance fluctuations as a
function of tunnel barriers, for both parametric variations of electron energy
or magnetoconductance fields. Furthermore, even for pure Dyson ensembles,
correlation functions of conductance fluctuations in chaotic quantum dots can
exhibit anti-correlation. Experimental support to our findings is pointed out.


title:
Scenario Analysis, Decision Trees and Simulation for Cost Benefit
  Analysis of the Cargo Screening Process

abstract:
  In this paper we present our ideas for conducting a cost benefit analysis by
using three different methods: scenario analysis, decision trees and
simulation. Then we introduce our case study and examine these methods in a
real world situation. We show how these tools can be used and what the results
are for each of them. Our aim is to conduct a comparison of these different
probabilistic methods of estimating costs for port security risk assessment
studies. Methodologically, we are trying to understand the limits of all the
tools mentioned above by focusing on rare events.


title: Some remarks on Calabi-Yau and hyper-K\"ahler foliations

abstract:
  We study Riemannian foliations whose transverse Levi-Civita connection
$\nabla$ has special holonomy. In particular, we focus on the case where
$Hol(\nabla)$ is contained either in SU(n) or in Sp(n). We prove a Weitzenbock
formula involving complex basic forms on K\"ahler foliations and we apply this
formula for pointing out some properties of transverse Calabi-Yau structures.
This allows us to prove that links provide examples of compact simply-connected
contact Calabi-Yau manifolds. Moreover, we show that a simply-connected compact
manifold with a K\"ahler foliation admits a transverse hyper- K\"ahler
structure if and only if it admits a compatible transverse hyper-Hermitian
structure. This latter result is the "foliated version" of a theorem proved by
Verbitsky. In the last part of the paper we adapt our results to the Sasakian
case, showing in addition that a compact Sasakian manifold has trivial
transverse holonomy if and only if it is a compact quotient of the Heisenberg
Lie group.


title:
Towards modelling cost and risks of infrequent events in the cargo
  screening process

abstract:
  We introduce a simulation model of the port of Calais with a focus on the
operation of immigration controls. Our aim is to compare the cost and benefits
of different screening policies. Methodologically, we are trying to understand
the limits of discrete event simulation of rare events. When will they become
'too rare' for simulation to give meaningful results?


title:
A possible role of sunrise/sunset azimuth in the planning of ancient
  Chinese towns

abstract:
  In the planning of some Chinese towns we can see an evident orientation with
the cardinal north-south direction. However, other features reveal a possible
orientation with the sunrise/sunset azimuth on solstices too, as in the case of
Shangdu (Xanadu), the summer capital of Kublai Khan. Here we discuss some other
examples of a possible solar orientation in the planning of ancient towns. We
will analyze the plans of Xi'an, Khanbalik and Dali.


title:
Calibration of Star-Formation Rate Measurements Across the
  Electromagnetic Spectrum

abstract:
  This is one chapter of the summary paper of the IAU Special Session SpS8
"Calibration of star-formation rate measurements across the electromagnetic
spectrum", Beijing, China, August 2012.


title:
Rate of three-body recombination of hydrogen molecules during primordial
  star formation

abstract:
  Astrophysical models of primordial star formation require rate constants for
three-body recombination as input. The current status of these rates for H2 due
to collisions with H is far from satisfactory, with published rate constants
showing orders of magnitude disagreement at the temperatures relevant for H2
formation in primordial gas. This letter presents an independent calculation of
this recombination rate constant as a function of temperature. An analytic
expression is provided for the rate constant which should be more reliable than
ones currently being used in astrophysical models.


title:
Quark nuggets search using 2350 Kg gravitational waves aluminum bar
  detectors

abstract:
  The gravitational wave resonant detectors can be used as detectors of quark
nuggets, like nuclearites (nuclear matter with a strange quark). This search
has been carried out using data from two 2350 Kg, 2 K cooled, aluminum bar
detectors: NAUTILUS, located in Frascati (Italy), and EXPLORER, that was
located in CERN Geneva (CH). Both antennas are equipped with cosmic ray shower
detectors: signals in the bar due to showers are continuously detected and used
to characterize the antenna performances. The bar excitation mechanism is based
on the so called thermo-acoustic effect, studied on dedicated experiments that
use particle beams. This mechanism predicts that vibrations of bars are induced
by the heat deposited in the bar from the particle. The geometrical acceptance
of the bar detectors is 19.5 $\rm m^2$ sr, that is smaller than that of other
detectors used for similar searches. However, the detection mechanism is
completely different and is more straightforward than in other detectors. We
will show the results of ten years of data from NAUTILUS (2003-2012) and 7
years from EXPLORER (2003-2009). The experimental limits we obtain are of
interest because, for nuclearites of mass less than $10^{-4}$ grams, we find a
flux smaller than that one predicted considering nuclearites as dark matter
candidates.

categories: astro-ph.HE astro-ph.IM hep-ex physics.ins-det


title: Electrostrong Nuclear Disintegration in Condensed Matter

abstract:
  Photo- and electro-disintegration techniques have been traditionally used for
studying giant dipole resonances and through them nuclear structure. Over a
long period, detailed theoretical models for the giant dipole resonances were
proposed and low energy electron accelerators were constructed to perform
experiments to test their veracity. More recently, through laser and "smart"
material devices, electrons have been accelerated in condensed matter systems
up to several tens of MeV. We discuss here the possibility of inducing
electro-disintegration of nuclei through such devices. It involves a synthesis
of electromagnetic and strong forces in condensed matter via giant dipole
resonances to give an effective "electro-strong interaction" - a large coupling
of electromagnetic and strong interactions in the tens of MeV range.


title: A variant of the multi-agent rendezvous problem

abstract:
  The classical multi-agent rendezvous problem asks for a deterministic
algorithm by which $n$ points scattered in a plane can move about at constant
speed and merge at a single point, assuming each point can use only the
locations of the others it sees when making decisions and that the visibility
graph as a whole is connected. In time complexity analyses of such algorithms,
only the number of rounds of computation required are usually considered, not
the amount of computation done per round. In this paper, we consider
$\Omega(n^2 \log n)$ points distributed independently and uniformly at random
in a disc of radius $n$ and, assuming each point can not only see but also, in
principle, communicate with others within unit distance, seek a randomised
merging algorithm which asymptotically almost surely (a.a.s.) runs in time
O(n), in other words in time linear in the radius of the disc rather than in
the number of points. Under a precise set of assumptions concerning the
communication capabilities of neighboring points, we describe an algorithm
which a.a.s. runs in time O(n) provided the number of points is $o(n^3)$.
Several questions are posed for future work.


title: The history of degenerate (bipartite) extremal graph problems

abstract:
  This paper is a survey on Extremal Graph Theory, primarily focusing on the
case when one of the excluded graphs is bipartite. On one hand we give an
introduction to this field and also describe many important results, methods,
problems, and constructions.


title:
Symmetric solutions of the dispersionless Toda hierarchy and associated
  conformal dynamics

abstract:
  Under certain reality conditions, a general solution to the dispersionless
Toda lattice hierarchy describes deformations of simply-connected plane domains
with a smooth boundary. The solution depends on an arbitrary (real positive)
function of two variables which plays the role of a density or a conformal
metric in the plane. We consider in detail the important class of symmetric
solutions characterized by the density functions that depend only on the
distance from the origin and that are positive and regular in an annulus $r_0<
|z|<r_1$. We construct the dispersionless tau-function which gives formal local
solution to the inverse potential problem and to the Riemann mapping problem
and discuss the associated conformal dynamics related to viscous flows in the
Hele-Shaw cell.


title:
Hard light meson production in (anti)proton-hadron collisions and
  charge-echange reactions

abstract:
  An extension of the QED 'return to resonance' mechanism to light meson
emission ($\pi$, $\rho$) in (anti)proton collisions with a hadronic target
(nucleon or nucleus) is proposed. The cross section and the multiplicity
distributions are calculated. The collinear emission (along the beam direction)
of a charged meson may be used to produce high energy (anti)neutron beams.
Possible applications at existing and planned facilities are considered.


title: Clinical Relationships Extraction Techniques from Patient Narratives

abstract:
  The Clinical E-Science Framework (CLEF) project was used to extract important
information from medical texts by building a system for the purpose of clinical
research, evidence-based healthcare and genotype-meets-phenotype informatics.
The system is divided into two parts, one part concerns with the identification
of relationships between clinically important entities in the text. The full
parses and domain-specific grammars had been used to apply many approaches to
extract the relationship. In the second part of the system, statistical machine
learning (ML) approaches are applied to extract relationship. A corpus of
oncology narratives that hand annotated with clinical relationships can be used
to train and test a system that has been designed and implemented by supervised
machine learning (ML) approaches. Many features can be extracted from these
texts that are used to build a model by the classifier. Multiple supervised
machine learning algorithms can be applied for relationship extraction. Effects
of adding the features, changing the size of the corpus, and changing the type
of the algorithm on relationship extraction are examined. Keywords: Text
mining; information extraction; NLP; entities; and relations.


title: Spinodal decomposition of a binary magnetic fluid confined to a surface

abstract:
  In our previous work [J. Chem. Phys. \textbf{136}, 024502 (2012)], we
reported a demixing phase transition of a two-dimensional, binary Heisenberg
fluid mixture driven by the ferromagnetic interactions of the magnetic species.
Here, we present a theoretical study for the \textit{time-dependent} coarsening
occuring within the two-phase region in the density-concentration plane, also
known as spinodal decomposition. Our investigations are based on Dynamical
Density Functional Theory (DDFT). The particles in the mixture are modelled as
Gaussian soft spheres on a two-dimensional surface, where one component carries
a classical spin of Heisenberg type. To investigate the two-phase region, we
first present a linear stability analysis with respect to small, harmonic
density perturbations. Second, to capture non-linear effects, we calculate
time-dependent structure factors by combining DDFT with Percus' test particle
method. For the growth of the average domain size $l$ during spinodal
decomposition with time $t$, we observe a power-law behavior $l\propto
t^{\delta_\alpha}$ with $\delta_m\simeq 0.333$ for the magnetic species and
$\delta_n\simeq 0.323$ for the non-magnetic species.


title: Numerical methods for convection-diffusion problems or The 30 years war

abstract:
  Convection-diffusion problems arise in the modelling of many physical
processes. Their typical solutions exhibit boundary and/or interior layers.
Despite the linear nature of the differential operator, these problems pose
still-unanswered questions to the numerical analyst.
  This talk will give a selective overview of numerical methods for the
solution of convection-diffusion problems, while placing them in a historical
context. It examines the principles that underpin the competing numerical
techniques in this area and presents some recent developments.


title: On the Hardnesses of Several Quantum Decoding Problems

abstract:
  We classify the time complexities of three important decoding problems for
quantum stabilizer codes. First, regardless of the channel model, quantum
bounded distance decoding is shown to be NP-hard, like what Berlekamp, McEliece
and Tilborg did for classical binary linear codes in 1978. Then over the
depolarizing channel, the decoding problems for finding a most likely error and
for minimizing the decoding error probability are also shown to be NP-hard. Our
results indicate that finding a polynomial-time decoding algorithm for general
stabilizer codes may be impossible, but this, on the other hand, strengthens
the foundation of quantum code-based cryptography.


title: Stripe Antiferromagnetic Spin Fluctuations in SrCo$_{2}$As$_{2}$

abstract:
  Inelastic neutron scattering measurements of paramagnetic SrCo$_{2}$As$_{2}$
at T=5 K reveal antiferromagnetic (AFM) spin fluctuations that are peaked at a
wavevector of $\textbf{Q}_{\mathrm{AFM}}=(1/2,1/2,1)$ and possess a large
energy scale. These stripe spin fluctuations are similar to those found in
$A$Fe$_{2}$As$_{2}$ compounds, where spin-density wave AFM is driven by Fermi
surface nesting between electron and hole pockets separated by
$\textbf{Q}_{\mathrm{AFM}}$. SrCo$_{2}$As$_{2}$ has a more complex Fermi
surface and band structure calculations indicate a potential instability
towards either a ferromagnetic or stripe AFM ground state. The results suggest
that stripe AFM magnetism is a general feature of both iron and cobalt-based
arsenides and the search for spin fluctuation-induced unconventional
superconductivity should be expanded to include cobalt-based compounds.


title: Limits and dynamics of randomly connected neuronal networks

abstract:
  Networks of the brain are composed of a very large number of neurons
connected through a random graph and interacting after random delays that both
depend on the anatomical distance between cells. In order to comprehend the
role of these random architectures on the dynamics of such networks, we analyze
the mesoscopic and macroscopic limits of networks with random correlated
connectivity weights and delays. We address both averaged and quenched limits,
and show propagation of chaos and convergence to a complex integral
McKean-Vlasov equations with distributed delays. We then instantiate a
completely solvable model illustrating the role of such random architectures in
the emerging macroscopic activity. We particularly focus on the role of
connectivity levels in the emergence of periodic solutions.


title: Counting list matrix partitions of graphs

abstract:
  Given a symmetric D*D matrix M over {0,1,*}, a list M-partition of a graph G
is a partition of G's vertices into D parts associated with the rows of M. The
part of each vertex is chosen from a given list so that no edge of G maps to a
0 in M and no non-edge of G maps to a 1 in M. Many important graph-theoretic
structures can be represented as list M-partitions, such as graph colourings,
split graphs and homogeneous sets and pairs, which arise in the proofs of the
weak and strong perfect graph conjectures. There has been quite a bit of work
on determining for which matrices M computations involving list M-partitions
are tractable. We focus on counting list M-partitions, given a graph G and a
list for each vertex of G. We identify a set of "tractable" matrices and give
an algorithm that counts list M-partitions in polynomial time for every (fixed)
matrix M in this set. The algorithm uses data structures such as sparse-dense
partitions and subcube decompositions to reduce each instance to a sequence of
instances in which the lists restrict access to portions of M in which the
interaction of 0s and 1s is controlled. We solve the resulting restricted
instances by converting them into counting constraint satisfaction problems
(#CSPs) which we solve using arc-consistency. For every matrix M for which our
algorithm fails, we show that counting list M-partitions is #P-complete.
Further, we give an explicit characterisation of the dichotomy theorem:
counting list M-partitions is in FP if M has a structure called a
derectangularising sequence; otherwise, counting list M-partitions is #P-hard.
We show that the meta-problem of determining whether a given matrix has a
derectangularising sequence is NP-complete. Finally, we show that lists can be
used to encode cardinality restrictions in M-partitions problems and use this
to give a polynomial-time algorithm for counting homogeneous pairs in graphs.


title: Analogue Transformations in Physics and their Application to Acoustics

abstract:
  Transformation optics has shaped up a revolutionary electromagnetic design
paradigm, enabling scientists to build astonishing devices such as invisibility
cloaks. Unfortunately, the application of transformation techniques to other
branches of physics is often constrained by the structure of the field
equations. We develop here a complete transformation method using the idea of
analogue spacetimes. The method is general and could be considered as a new
paradigm for controlling waves in different branches of physics, from acoustics
in quantum fluids to graphene electronics. As an application, we derive an
"analogue transformation acoustics" formalism that naturally allows the use of
transformations mixing space and time or involving moving fluids, both of which
were impossible with the standard approach. To demonstrate the power of our
method, we give an explicit design of a spacetime compressor for acoustic waves
and a carpet cloak for a moving aircraft.


title:
Compositional diversity in the atmospheres of hot Neptunes, with
  application to GJ 436b

abstract:
  Neptune-sized extrasolar planets that orbit relatively close to their host
stars -- often called "hot Neptunes" -- are common within the known population
of exoplanets and planetary candidates. Similar to our own Uranus and Neptune,
inefficient accretion of nebular gas is expected produce hot Neptunes whose
masses are dominated by elements heavier than hydrogen and helium. At high
atmospheric metallicities of 10-10,000x solar, hot Neptunes will exhibit an
interesting continuum of atmospheric compositions, ranging from more
Neptune-like, H2-dominated atmospheres to more Venus-like, CO2-dominated
atmospheres. We explore the predicted equilibrium and disequilibrium chemistry
of generic hot Neptunes and find that the atmospheric composition varies
strongly as a function of temperature and bulk atmospheric properties such as
metallicity and the C/O ratio. Relatively exotic H2O, CO, CO2, and even
O2-dominated atmospheres are possible for hot Neptunes. We apply our models to
the case of GJ 436b, where we find that a CO-rich, CH4-poor atmosphere can be a
natural consequence of a very high atmospheric metallicity. From comparisons of
our results with Spitzer eclipse data for GJ 436b, we conclude that although
the spectral fit from the high-metallicity forward models is not quite as good
as the fit obtained from pure retrieval methods, the atmospheric composition
predicted by these forward models is more physically and chemically plausible.
High-metallicity atmospheres (orders of magnitude in excess of solar) should
therefore be considered as a possibility for GJ 436b and other hot Neptunes.


title: How are mortality rates affected by population density?

abstract:
  Biologists have found that the death rate of cells in culture depends upon
their spatial density. Permanent "Stay alive" signals from their neighbours
seem to prevent them from dying. In a previous paper (Wang et al. 2013) we gave
evidence for a density effect for ants. In this paper we examine whether there
is a similar effect in human demography. We find that although there is no
observable relationship between population density and overall death rates,
there is a clear relationship between density and the death rates of young
age-groups. Basically their death rates decrease with increasing density.
However, this relationship breaks down around 300 inhabitants per square
kilometre. Above this threshold the death rates remains fairly constant. The
same density effect is observed in Canada, France, Japan and the United States.
We also observe a striking parallel between the density effect and the
so-called marital status effect in the sense that they both lead to higher
suicide rates and are both enhanced for younger age-groups. However, it should
be noted that the strength of the density effect is only a fraction of the
strength of the marital status effect. In spite of the fact that this parallel
does not give us an explanation by itself, it invites us to focus on
explanations that apply to both effects. In this light the "Stay alive"
paradigm set forth by Prof. Martin Raff appears as a natural interpretation. It
can be seen as an extension of the "social ties" framework proposed at the end
of the 19th century by the sociologist Emile Durkheim in his study about
suicide.


title:
A Comparative study of Analog and digital Controller On DC/DC Buck-Boost
  Converter Four Switch for Mobile Device Applications

abstract:
  This paper presents comparative performance between Analog and digital
controller on DC/DC buck-boost converter four switch. The design of power
electronic converter circuit with the use of closed loop scheme needs modeling
and then simulating the converter using the modeled equations. This can easily
be done with the help of state equations and MATLAB/SIMULINK as a tool for
simulation of those state equations. DC/DC Buckboost converter in this study is
operated in buck (step-down) and boost (step-up) modes.


title: Coupling a single electron to a Bose-Einstein condensate

abstract:
  The coupling of electrons to matter is at the heart of our understanding of
material properties such as electrical conductivity. One of the most intriguing
effects is that electron-phonon coupling can lead to the formation of a Cooper
pair out of two repelling electrons, the basis for BCS superconductivity. Here
we study the interaction of a single localized electron with a Bose-Einstein
condensate (BEC) and show that it can excite phonons and eventually set the
whole condensate into a collective oscillation. We find that the coupling is
surprisingly strong as compared to ionic impurities due to the more favorable
mass ratio. The electron is held in place by a single charged ionic core
forming a Rydberg bound state. This Rydberg electron is described by a
wavefunction extending to a size comparable to the dimensions of the BEC,
namely up to 8 micrometers. In such a state, corresponding to a principal
quantum number of n=202, the Rydberg electron is interacting with several tens
of thousands of condensed atoms contained within its orbit. We observe
surprisingly long lifetimes and finite size effects due to the electron
exploring the wings of the BEC. Based on our results we anticipate future
experiments on electron wavefunction imaging, investigation of phonon mediated
coupling of single electrons, and applications in quantum optics.


title:
Crystal, magnetic, and electronic structures, and properties of new
  BaMnPnF (Pn = As, Sb, Bi)

abstract:
  New fluoropnictides BaMnPnF with Pn = As, Sb, Bi, are synthesized by
stoichiometric reaction of elements with BaF\_2. The compounds crystallize in
the tetragonal P4/nmm (No. 129, Z = 2) space group, with the ZrCuSiAs-type
structure, as indicated by single crystal and powder X-ray diffraction results.
Electrical resistivity results indicate that Pn = As, Sb, and Bi are
semiconductors with band gaps of E\_g = 0.73 eV, E\_g = 0.48 eV and E\_g =
0.003 eV, respectively. Powder neutron diffraction reveals a G-type
antiferromagnetic order below T\_N = 338(1) K for Pn = As, and below T\_N =
272(1) K for Pn = Sb. Magnetic susceptibility increases with temperature above
100 K for all the materials. Density functional calculations also find
semiconducting antiferromagnetic compounds with strong in-plane and weaker
out-of-plane exchange coupling that may result in non-Curie Weiss behavior
above T\_N. There is strong covalency between Mn and pnictogen elements. The
ordered magnetic moments are 3.65(5) {\mu}B/Mn for Pn = As, and 3.66(3)
{\mu}B/Mn for Pn = Sb at 4 K, as refined from neutron diffraction experiments.


title: Investigation of the Lambda(1405) line shape observed in pp collisions

abstract:
  In this work we investigate different possible explanations for the observed
low mass {\Lambda}(1405) signal associated to the production of the
{\Lambda}(1405) in p+p reactions at 3.5 GeV beam kinetic energy measured by the
HADES collaboration. We study the influence of interference effects between the
{\Lambda}(1405) resonance and the non-resonant background. Furthermore, we
present a phenomenological method to use the HADES data for determining the
relative contribution of the two {\Lambda}(1405) poles and discuss to which
extent the data can constrain the position of these poles in the complex energy
plane.


title:
A new interferometer architecture combining nulling with phase closure
  measurements

abstract:
  Imaging the direct light signal from a faint exoplanet against the
overwhelming glare of its host star presents one of the fundamental challenges
to modern astronomical instrumentation. Achieving sufficient signal-to-noise
for detection by direct imaging is limited by three basic physical processes:
aberration of the wavefronts (both instrumental and atmospheric), photon noise,
and detector noise. In this paper, we advance a novel optical setup which
synthesizes the advantages of two different techniques: nulling interferometry
to mitigate photon noise, and closure phase to combat optical aberrations. Our
design, which employs technology from integrated optics and photonics, is
intended to combine the advantageous aspects of both a coronagraph and a
non-redundant interferometer inside a single optical device. We show that such
an instrument would have a dynamic range limited either by i) the readout noise
(if perfect co-phasing), or ii) the photon noise due to stellar flux leakage
(in the case of imperfect nulling). This concept is optimal when the readout
noise is not the main limitation, ie, for space interferometry or for ground
based observations of bright stellar hosts (apparent magnitude brighter than
10).


title: Layer-multiplicity as a community order-parameter

abstract:
  A small number of (perhaps only 6) broken-symmetries, marked by the edges of
a hierarchical series of physical {\em subsystem-types}, underlie the delicate
correlation-based complexity of life on our planet's surface. Order-parameters
associated with these broken symmetries might in the future help us broaden our
definitions of community health. For instance we show that a model of metazoan
attention-focus, on correlation-layers that look in/out from the 3 boundaries
of skin, family & culture, predicts that behaviorally-diverse communities
require a characteristic task layer-multiplicity {\em per individual} of only
about $4 \frac14$ of the six correlation layers that comprise that community.
The model may facilitate explorations of task-layer diversity, go beyond GDP &
body count in quantifying the impact of policy-changes & disasters, and help
manage electronic idea-streams in ways that strengthen community networks.
Empirical methods for acquiring task-layer multiplicity data are in their
infancy, although experience-sampling via cell-phone button-clicks might be one
place to start.


title:
Incidence of the Bertillon and Gompertz effects on the outcome of
  clinical trials

abstract:
  The accounts of medical trials provide very detailed information about the
patients' health conditions. In contrast, only minimal data are usually given
about demographic factors. Yet, some of these factors can have a notable impact
on the overall death rate, thereby changing the outcome and conclusions of the
trial. This paper focuses on two of these variables. The first is marital
status; this effect, which will be referred to as the Bertillon effect, may
change death rates by over 100%. The second is the age of the oldest patients;
because of the exponential nature of Gompertz's law, changes in the
distribution of ages in the oldest age group can have dramatic consequences on
the overall number of deaths. It will be seen that randomization alone can
hardly take care of these problems. Appropriate remedies are easy to formulate
however. First, the marital status of patients as well as the age distribution
of those over 65 should be documented for both study groups. Then, thanks to
these data and based on the Bertillon and Gompertz laws, it will become
possible to perform appropriate corrections. Such corrections will notably
improve the reliability and accuracy of the trial's conclusions, especially for
trials which include a large proportion of elderly subjects.


title:
Hot-spot model for accretion disc variability as random process - II.
  Mathematics of the power-spectrum break frequency

abstract:
  We study some general properties of accretion disc variability in the context
of stationary random processes. In particular, we are interested in
mathematical constraints that can be imposed on the functional form of the
Fourier power-spectrum density (PSD) that exhibits a multiply broken shape and
several local maxima. We develop a methodology for determining the regions of
the model parameter space that can in principle reproduce a PSD shape with a
given number and position of local peaks and breaks of the PSD slope. Given the
vast space of possible parameters, it is an important requirement that the
method is fast in estimating the PSD shape for a given parameter set of the
model. We generated and discuss the theoretical PSD profiles of a
shot-noise-type random process with exponentially decaying flares. Then we
determined conditions under which one, two, or more breaks or local maxima
occur in the PSD. We calculated positions of these features and determined the
changing slope of the model PSD. Furthermore, we considered the influence of
the modulation by the orbital motion for a variability pattern assumed to
result from an orbiting-spot model. We suggest that our general methodology can
be useful in for describing non-monotonic PSD profiles (such as the trend seen,
on different scales, in exemplary cases of the high-mass X-ray binary Cygnus
X-1 and the narrow-line Seyfert galaxy Ark 564). We adopt a model where these
power spectra are reproduced as a superposition of several Lorentzians with
varying amplitudes in the X-ray-band light curve. Our general approach can help
in constraining the model parameters and in determining which parts of the
parameter space are accessible under various circumstances.


title: Magnetic properties of a family of quinternary oxalates

abstract:
  We report on the magnetic properties of four isomorphous compounds of a
family of quinternary oxalates down to 60 mK. In all these materials, the
magnetic FeII ions with a strong magneto-crystalline anisotropy form a
distorted kagome lattice, topologically equivalent to a perfect kagome one if
nearest-neighbor interactions only are considered. All the compounds order at
low temperature in an antiferromagnetic arrangement with magnetic moments at
120{\deg}. A remarkable magnetic behavior emerges below the N\'eel temperature
in three compounds (with inter-kagome-layer Zr, Sn, Fe but not with Al): the
spin anisotropy combined with a low exchange path network connectivity lead to
domain walls intersecting the kagome planes through strings of free spins.
These produce an unfamiliar slow spin dynamics in the ordered phase observed by
AC susceptibility, evolving from exchange-released spin-flips towards a
cooperative behavior on decreasing the temperature.


title: Increasing supercycle lengths of active SU UMa-type dwarf novae

abstract:
  We present observational evidence that supercycle lengths of the most active
SU UMa-type stars are increasing during the past decades. We analysed a large
number of photometric measurements from available archives and found that this
effect is generic for this class of stars, independently of their evolutionary
status. This finding is in agreement with previous predictions and the most
recent work of Patterson et al. (2012) on BK Lyn.


title:
Exchange interactions and frustrated magnetism in single-side
  hydrogenated and fluorinated graphene

abstract:
  Magnetism in single-side hydrogenated (C$_2$H) and fluorinated (C$_2$F)
graphene is analyzed in terms of the Heisenberg model with parameters
determined from first principles. We predict a frustrated ground state for both
systems, which means the instability of collinear spin structures and sheds
light on the absence of a conventional magnetic ordering in defective graphene
demonstrated in recent experiments. Moreover, our findings suggest a highly
correlated magnetic behavior at low temperatures offering the possibility of a
spin-liquid state.


title: A new look at the symbiotic star RW Hydrae

abstract:
  We present new estimates of the basic stellar parameters of the non-eruptive,
eclipsing symbiotic system, RW Hydrae. A set of photometric and spectroscopic
data was used to model this object simultaneously from the light and radial
velocity curves. With new spectroscopic data we were able to improve previous
results known from the literature and derive physical parameters of the system:
$q=4.2$, $M_1=0.8 \rm M_\odot$, $M_2=3.4 \rm M_\odot$, $R_1=0.2 \rm R_\odot$,
$R_2=145 \rm R_\odot$, $a=350 \rm R_\odot$, and $i=75^\circ$.


title: State Decoding in Multi-Stage Cryptography Protocols

abstract:
  This paper presents a practical method of quantum tomography for decoding the
state of photons in a multistage cryptography protocol. This method works if
the polarization angles are defined on a fixed plane, as is assumed in several
quantum cryptography protocols. We show if there are 2m polarization angles in
a fixed plane, we need m number of filters and m2 number of photons through
each filter.


title:
Equivalence classes of subquotients of pseudodifferential operator
  modules

abstract:
  Consider the spaces of pseudodifferential operators between tensor density
modules over the line as modules of the Lie algebra of vector fields on the
line. We compute the equivalence classes of various subquotients of these
modules. There is a 2-parameter family of subquotients with any given
Jordan-Holder composition series. In the critical case of subquotients of
length 5, the equivalence classes within each non-resonant 2-parameter family
are specified by the intersections of a pencil of conics with a pencil of
cubics. In the case of resonant subquotients of length 4 with self-dual
composition series, as well as of lacunary subquotients of lengths 3 and 4,
equivalence is specified by a single pencil of conics. Non-resonant
subquotients of length exceeding 7 admit no non-obvious equivalences. The cases
of lengths 6 and 7 are unresolved.


title:
Anti-parallel EUV flows observed along active region filament threads
  with Hi-C

abstract:
  Plasma flows within prominences/filaments have been observed for many years
and hold valuable clues concerning the mass and energy balance within these
structures. Previous observations of these flows primarily come from H-alpha
and cool EUV lines (e.g., 304A) where estimates of the size of the prominence
threads has been limited by the resolution of the available instrumentation.
Evidence of `counter-steaming' flows has previously been inferred from these
cool plasma observations but now, for the first time, these flows have been
directly imaged along fundamental filament threads within the million degree
corona (at 193A). In this work we present observations of an active region
filament observed with Hi-C that exhibits anti-parallel flows along adjacent
filament threads. Complementary data from SDO/AIA and HMI are presented. The
ultra-high spatial and temporal resolution of Hi-C allow the anti-parallel flow
velocities to be measured (70-80 km/s) and gives an indication of the
resolvable thickness of the individual strands (0.8'' +/- 0.1''). The
temperature distribution of the plasma flows was estimated to be log T(K) =
5.45 +/- 0.10 using EM loci analysis. We find that SDO/AIA cannot clearly
observe these anti-parallel flows nor measure their velocity or thread width
due to its larger pixel size. We suggest that
  anti-parallel/counter-streaming flows are likely commonplace within all
filaments and are currently not observed in EUV due to current instrument
spatial resolution.


title:
Magnetic ordering in GdNi2B2C revisited by resonant x-ray scattering:
  evidence for the double-q model

abstract:
  Recent theoretical efforts aimed at understanding the nature of
antiferromagnetic ordering in GdNi2B2C predicted double-q ordering. Here we
employ resonant elastic x-ray scattering to test this theory against the
formerly proposed, single-q ordering scenario. Our study reveals a satellite
reflection associated with a mixed-order component propagation wave vector,
viz., (q_a,2q_b,0) with q_b = q_a approx= 0.55 reciprocal lattice units, the
presence of which is incompatible with single-q ordering but is expected from
the double-q model. A (3q_a,0,0) wave vector (i.e., third-order) satellite is
also observed, again in line with the double-q model. The temperature
dependencies of these along with that of a first-order satellite are compared
with calculations based on the double-q model and reasonable qualitative
agreement is found. By examining the azimuthal dependence of first-order
satellite scattering, we show the magnetic order to be, as predicted,
elliptically polarized at base temperature and find the temperature dependence
of the "out of a-b plane" moment component to be in fairly good agreement with
calculation. Our results provide qualitative support for the double-q model and
thus in turn corroborate the explanation for the "magnetoelastic paradox"
offered by this model.


title:
Interspecies collision-induced losses in a dual species 7Li-85Rb
  magneto-optical trap

abstract:
  In this article, we report the measurement of collision-induced loss rate
coefficients \beta_{Li,Rb} and \beta_{Rb,Li}, and also discuss means to
significantly suppress such collision induced losses. We first describe our
dual-species magneto-optical trap (MOT) that allows us to simultaneously trap >
5x10^8 7Li atoms loaded from a Zeeman slower and > 2x10^8 85Rb atoms loaded
from a dispenser. We observe strong interspecies collision-induced losses in
the MOTs which dramatically reduce the maximum atom number achievable in the
MOTs. We measure the trap loss rate coefficients \beta_{Li,Rb} and
\beta_{Rb,Li}, and, from a study of their dependence on the MOT parameters,
determine the cause for the losses observed. Our results provide valuable
insights into ultracold collisions between 7Li and 85Rb, guide our efforts to
suppress collision induced losses, and also pave the way for the production of
ultracold 7Li85Rb molecules.


title:
Maximum principles for boundary-degenerate linear parabolic differential
  operators

abstract:
  We develop weak and strong maximum principles for boundary-degenerate,
linear, parabolic, second-order partial differential operators, $Lu :=
-u_t-\tr(aD^2u)-\langle b, Du\rangle + cu$, with \emph{partial} Dirichlet
boundary conditions. The coefficient, $a(t,x)$, is assumed to vanish along a
non-empty open subset, $\mydirac_0!\sQ$, called the \emph{degenerate boundary
portion}, of the parabolic boundary, $\mydirac!\sQ$, of the domain
$\sQ\subset\RR^{d+1}$, while $a(t,x)$ may be non-zero at points in the
\emph{non-degenerate boundary portion}, $\mydirac_1!\sQ :=
\mydirac!\sQ\less\bar{\mydirac_0!\sQ}$. Points in $\mydirac_0!\sQ$ play the
same role as those in the interior of the domain, $\sQ$, and only the
non-degenerate boundary portion, $\mydirac_1!\sQ$, is required for boundary
comparisons. We also develop comparison principles and a priori maximum
principle estimates for solutions to boundary value and obstacle problems
defined by boundary-degenerate parabolic operators, again where only the
non-degenerate boundary portion, $\mydirac_1!\sQ$, is required for boundary
comparisons. Our results complement those in our previous articles
[arXiv1204.6613, arXiv:1305.5098].


title: Dynamic Assessment Indices

abstract:
  This paper provides a unified framework, which allows, in particular, to
study the structure of dynamic monetary risk measures and dynamic acceptability
indices. The main mathematical tool, which we use here, and which allows us to
significantly generalize existing results is the theory of $L^0$-modules. In
the first part of the paper we develop the general theory and provide a robust
representation of conditional assessment indices, and in the second part we
apply this theory to dynamic acceptability indices acting on stochastic
processes.


title:
Can spicules be detected at disc centre in broad-band Ca II H filter
  imaging data ?

abstract:
  We estimate the formation height range contributing to broad-band and
narrow-band filter imaging data in Ca II H to investigate whether spicules can
be detected in such observations at the centre of the solar disc. We apply
spectral filters of FWHMs from 0.03 nm to 1 nm to observed Ca line profiles to
simulate Ca imaging data. We estimate the relative intensity contributions of
off-limb and on-disc structures. We compare the synthetic Ca filter imaging
data with intensity maps of Ca spectra at different wavelengths and temperature
maps at different optical depths. We determine the intensity response function
for the wavelengths covered by the filters of different FWHM.
  The intensity emitted off the solar limb is about 5% of the intensity at disc
centre. For a 0.3 nm-wide Ca II H filter, up to about 1/3 of the off-limb
intensity comes from emission in Hepsilon. On the disc, only about 15% of the
intensity transmitted through a broad-band filter comes from the line-core
region. No traces of elongated fibrillar structures are visible in imaging data
at disc centre, opposite to the line-core images of the Ca spectra. The
response function for a 0.3 nm-wide filter peaks at about 200 km. Relative
contributions from atmospheric layers above 800 km are about 10%. The inversion
results suggest that the slightly enhanced emission around the photospheric
magnetic network in broad-band Ca imaging data is caused by a thermal canopy at
a height of about 600 km. Broad-band Ca II H imaging data do not trace upper
chromospheric structures such as spicules in observations at the solar disc
because of the too small relative contribution of the line core to the total
wavelength-integrated filter intensity.


title: Scrambling with Matrix Black Holes

abstract:
  If black holes are not to be dreaded syncs of information but be fully
described by unitary evolution, they must scramble in-falling data and
eventually leak it through Hawking radiation. Sekino and Susskind have
conjectured that black holes are fast scramblers: they generate entanglement at
a remarkably efficient rate, with characteristic time scaling logarithmically
with the entropy. In this work, we focus on Matrix theory -- M theory in the
light-cone frame -- and directly probe the conjecture. We develop a concrete
test bed for quantum gravity using the fermionic variables of Matrix theory and
show that the problem becomes that of chains of qubits with an intricate
network of interactions. We demonstrate that the black hole system evolves much
like a Brownian quantum circuit, with strong indications that it is indeed a
fast scrambler. We also analyze the Berenstein-Maldacena-Nastase model and
reach the same tentative conclusion.


title: Billiard dynamics of bouncing dumbbell

abstract:
  A system of two masses connected with a weightless rod (called dumbbell in
this paper) interacting with a flat boundary is considered. The sharp bound on
the number of collisions with the boundary is found using billiard techniques.
In case, the ratio of masses is large and the dumbbell rotates fast, an
adiabatic invariant is obtained.


title: Nonparametric Bayesian grouping methods for spatial time-series data

abstract:
  We describe an approach for identifying groups of dynamically similar
locations in spatial time-series data based on a simple Markov transition
model. We give maximum-likelihood, empirical Bayes, and fully Bayesian
formulations of the model, and describe exhaustive, greedy, and MCMC-based
inference methods. The approach has been employed successfully in several
studies to reveal meaningful relationships between environmental patterns and
disease dynamics.


title:
New examples of non-symmetric Einstein solvmanifolds of negative Ricci
  curvature

abstract:
  We obtain new examples of non-symmetric Einstein solvmanifolds by combining
two techniques.
  In \cite{T2}, H. Tamaru constructs new {\em attached} solvmanifolds, which
are submanifolds of the solvmanifolds corresponding to noncompact symmetric
spaces, endowed with a natural metric. Extending this construction, we apply it
to {\em associated} solvmanifolds, described in \cite{GK}, obtained by
modifying the algebraic structure of the solvable Lie algebras corresponding to
noncompact symmetric spaces. Our new examples are Einstein solvmanifolds with
nilradicals of high nilpotency, which are geometrically distinct from
noncompact symmetric spaces and their submanifolds.


title:
Is the Sample Good Enough? Comparing Data from Twitter's Streaming API
  with Twitter's Firehose

abstract:
  Twitter is a social media giant famous for the exchange of short,
140-character messages called "tweets". In the scientific community, the
microblogging site is known for openness in sharing its data. It provides a
glance into its millions of users and billions of tweets through a "Streaming
API" which provides a sample of all tweets matching some parameters preset by
the API user. The API service has been used by many researchers, companies, and
governmental institutions that want to extract knowledge in accordance with a
diverse array of questions pertaining to social media. The essential drawback
of the Twitter API is the lack of documentation concerning what and how much
data users get. This leads researchers to question whether the sampled data is
a valid representation of the overall activity on Twitter. In this work we
embark on answering this question by comparing data collected using Twitter's
sampled API service with data collected using the full, albeit costly, Firehose
stream that includes every single published tweet. We compare both datasets
using common statistical metrics as well as metrics that allow us to compare
topics, networks, and locations of tweets. The results of our work will help
researchers and practitioners understand the implications of using the
Streaming API.


title:
On Filtering Schemes in the Quantum-Classical Liouville Approach to
  Non-adiabatic Dynamics

abstract:
  We study a number of filtering schemes for the reduction of the statistical
error in non-adiabatic calculations by means of the quantum-classical Liouville
equation. In particular, we focus on a scheme based on setting a threshold
value on the sampling weights, so that when the threshold is overcome the value
of the weight is reset, and on another approach which prunes the ensemble of
the allowed non-adiabatic transitions according to a generalised sampling
probability. Both methods have advantages and drawbacks, however their
combination drastically improves the performance of an algorithm known as the
Sequential Short Time Step Propagation [D. MacKernan et al., J. Phys: Condens.
Matter {\bf 14} 9069 (2002)], which is derived from a simple first order
expansion of the quantum-classical propagator. Such an algorithm together with
the combined filtering procedures produce results that compare very well with
those obtained by means of numerically "exact" quantum calculations for the
spin-boson model, even for intermediate and strong coupling regimes.


title: The boundary is mixed

abstract:
  We show that Oeckl's boundary formalism incorporates quantum statistical
mechanics naturally, and we formulate general-covariant quantum statistical
mechanics in this language. We illustrate the formalism by showing how it
accounts for the Unruh effect. We observe that the distinction between pure and
mixed states weakens in the general covariant context, and surmise that local
gravitational processes are indivisibly statistical with no possible quantal
versus probabilistic distinction.


title:
Interpretation of the unprecedentedly long-lived high-energy emission of
  GRB 130427A

abstract:
  High energy photons (>100 MeV) are detected by the Fermi/LAT from GRB 130427A
up to almost one day after the burst, with an extra hard spectral component
being discovered in the high-energy afterglow. We show that this hard spectral
component arises from afterglow synchrotron-self Compton emission. This
scenario can explain the origin of >10 GeV photons detected up to ~30000s after
the burst, which would be difficult to be explained by synchrotron radiation
due to the limited maximum synchrotron photon energy. The lower energy
multi-wavelength afterglow data can be fitted simultaneously by the afterglow
synchrotron emission. The implication of detecting the SSC emission for the
circumburst environment is discussed.


title:
Longitudinal fluctuations of the center of mass of the participants in
  heavy-ion collisions

abstract:
  A model for computing the probability density of event-by-event participant
center-of-mass rapidity y^{c.m.} is presented. The evaluations of the y^{c.m.}
distribution are performed for different collision energies and different
centralities. We show that for certain conditions the rapidity distribution is
described by a Gaussian with a variance determined mostly by the collision
centrality. It is found that the width of the y^{c.m.} distribution increases
strongly for more peripheral collisions, while it depends weakly on the
collision energy. Other theoretical estimates of rapidity distribution are
presented and questions of interaction and separation between spectators and
participants are discussed.


title:
Review Study For Inter-Operability Of Manet Protocols In Wireless Sensor
  Networks

abstract:
  Wireless Networks are most appealing in terms of deployment over a wide range
of applications. The key areas are disaster management, industrial unit
automation and battlefield surveillance. The paper presents a study over
inter-operability of MANET (Mobile Ad-Hoc Network) protocols i.e DSDV, OLSR,
ZRP, AODV over WSN (Wireless Sensor Network) [10]. The review here covers all
the prevailing protocol solutions for WSN and deployment of MANET protocols
over them. The need of moving to MANET protocols lie in situation when we talk
about mobile sensory nodes which are a compulsion when we talk about the above
mentioned three areas. However, the deployment may not be limited to these
only.


title: Froissart Bound on Total Cross-section without Unknown Constants

abstract:
  We determine the scale of the logarithm in the Froissart bound on total
cross-sections using absolute bounds on the D-wave below threshold for $\pi\pi$
scattering. E.g. for $\pi^0 \pi^0$ scattering we show that for c.m. energy
$\sqrt{s}\rightarrow \infty $, $\bar{\sigma}_{tot}(s,\infty)\equiv s\int_{s}
^{\infty} ds'\sigma_{tot}(s')/s'^2 \leq \pi (m_{\pi})^{-2} [\ln
(s/s_0)+(1/2)\ln \ln (s/s_0) +1]^2$ where $m_\pi^2/s_0= 17\pi \sqrt{\pi/2} $ .


title:
Contradictory entropic joint uncertainty relations for complementary
  observables in two-level systems

abstract:
  We show that different entropic measures of fluctuations lead to
contradictory uncertainty relations for two complementary observables. We apply
Tsallis and R\'{e}nyi entropies to the joint distribution emerging from a noisy
simultaneous measurement of both observables as well as to the product of their
individual statistics, either intrinsic or of operational origin.


title:
Implications of Charge Ordering in the High Tc Cuprate Superconductors
  in the Far-infrared Spectroscopy

abstract:
  We addressed the issue of the absence of the far-infrared signatures
pertaining to charge ordering in the published far-infrared reflectivity data
of La2-xSrxCuO4 single crystals while other experimental probes unravel that
charge ordering is a hallmark of the superconducting cuprates. Through direct
comparison of the far-infrared data reported by various groups side by side and
also with the Raman scattering data, we found that the inconsistencies stem
from the failure in capturing delicate spectral features embedded in the
close-to-perfect ab-plane far-infrared reflectivity of La2-xSrxCuO4 single
crystals by misidentifying the reflectivity as the Drude-like metallic
reflectivity. The analysis of the close-to-true reflectivity data reveals that
only a small fraction (< 3 %) of the total doping-induced charge carriers
(electrons) are itinerant on the electron lattice made up with the rest of the
electrons (> 97 %) at all doping levels up to 16 %. We conclude that the
far-infrared reflectivity study is far from being ready to construct a coherent
picture of the ubiquitous charge ordering phenomenon and its relationship with
the high Tc superconductivity.


title:
Optimal Regularity and the Free Boundary in the Parabolic Signorini
  Problem

abstract:
  We give a comprehensive treatment of the parabolic Signorini problem based on
a generalization of Almgren's monotonicity of the frequency. This includes the
proof of the optimal regularity of solutions, classification of free boundary
points, the regularity of the regular set and the structure of the singular
set.


title: Glitch recoveries in radio-pulsars and magnetars

abstract:
  Pulsar glitches are sudden increases in the spin frequency of an otherwise
steadily spinning down neutron star. These events are thought to represent a
direct probe of the dynamics of the superfluid interior of the star. However
glitches can differ significantly from one another, not only in size and
frequency, but also in the post-glitch response of the star. Some appear as
simple steps in frequency, while others also display an increase in spin-down
rate after the glitch. Others still show several exponentially relaxing
components in the post-glitch recovery. We show that if glitches are indeed due
to large scale unpinning of superfluid vortices, the different regions in which
this occurs and respective timescales on which they recouple can lead to the
various observed signatures. Furthermore we show that this framework naturally
accounts for the peculiar relaxations of glitches in Anomalous X-ray Pulsars.


title:
Epistemology of Modeling and Simulation: How can we gain Knowledge from
  Simulations?

abstract:
  Epistemology is the branch of philosophy that deals with gaining knowledge.
It is closely related to ontology. The branch that deals with questions like
"What is real?" and "What do we know?" as it provides these components. When
using modeling and simulation, we usually imply that we are doing so to either
apply knowledge, in particular when we are using them for training and
teaching, or that we want to gain new knowledge, for example when doing
analysis or conducting virtual experiments. This paper looks at the history of
science to give a context to better cope with the question, how we can gain
knowledge from simulation. It addresses aspects of computability and the
general underlying mathematics, and applies the findings to validation and
verification and development of federations. As simulations are understood as
computable executable hypotheses, validation can be understood as hypothesis
testing and theory building. The mathematical framework allows furthermore
addressing some challenges when developing federations and the potential
introduction of contradictions when composing different theories, as they are
represented by the federated simulation systems.


title:
Modification to Darcy model for high pressure and high velocity
  applications and associated mixed finite element formulations

abstract:
  The Darcy model is based on a plethora of assumptions. One of the most
important assumptions is that the Darcy model assumes the drag coefficient to
be constant. However, there is irrefutable experimental evidence that
viscosities of organic liquids and carbon-dioxide depend on the pressure.
Experiments have also shown that the drag varies nonlinearly with respect to
the velocity at high flow rates. In important technological applications like
enhanced oil recovery and geological carbon-dioxide sequestration, one
encounters both high pressures and high flow rates. It should be emphasized
that flow characteristics and pressure variation under varying drag are both
quantitatively and qualitatively different from that of constant drag.
Motivated by experimental evidence, we consider the drag coefficient to depend
on both the pressure and velocity. We consider two major modifications to the
Darcy model based on the Barus formula and Forchheimer approximation. The
proposed modifications to the Darcy model result in nonlinear partial
differential equations, which are not amenable to analytical solutions. To this
end, we present mixed finite element formulations based on least-squares
formalism and variational multiscale formalism for the resulting governing
equations. The proposed modifications to the Darcy model and its associated
finite element formulations are used to solve realistic problems with relevance
to enhanced oil recovery. We also study the competition between the nonlinear
dependence of drag on the velocity and the dependence of viscosity on the
pressure. To the best of the authors' knowledge such a systematic study has not
been performed.


title:
A hyperbolic system and the cost of null controllability for the Stokes
  system

abstract:
  This paper is devoted to study the cost of the null controllability for the
Stokes system. Using the control transmutation method we show that the cost of
driving the Stokes system to rest at time T is of order e^C/T when T
-->0^+,i.e., the same order as for the heat equation. For this to be possible,
we are led to study the exact controllability of one hyperbolic system with a
resistance term, which will be done under assumptions on the control region.


title:
The Chrial Magnetic Wave and Strong Field Effects in Heavy Ion
  Collisions

abstract:
  A number of recent progresses in the study of strong field effects in heavy
ion collisions are discussed here: 1) the Chiral Magnetic Wave (CMW) and its
experimental manifestation via splitting of positive/negative pions' elliptic
flow; 2) the event-by-event azimuthal fluctuations of strong EM fields and its
correlations with matter geometry; 3) a new mechanism for generating axial
current in external electric field, the Chiral Electric Separation Effect
(CESE).


title:
On the Heisenberg principle at macroscopic scales: understanding
  classical negative information. Towards a general physical theory of
  information

abstract:
  With the aid of a toy model, the Monty Hall Problem (MHP), the
counterintuitive and theoretically problematic concept of negative information
in classical systems is well understood. It is shown that, as its quantum
counterpart, classical local mutual information, obtained through a
measurement, can be expressed as the difference between the information gained
with the evidence and the negative information generated due to the
inefficiency of the measurement itself; a novel local Shannon metric, the
transfer information content, is defined as this difference, which is negative
if the measurement generates more disturbance than the evidence, i.e.,
generates a classical measurement back action. This metric is valid for both,
Classical and Quantum measurements, and it is proposed as a starting point
towards a general physical theory of information. This information-disturbance
trade-off in classical measurements is a kind of Heisenberg principle at
macroscopic scales, and it is proposed, as further work, to incorporate this
result in the already existing generalized uncertainty principles in the field
of quantum gravity.


title: Universality Class in Conformal Inflation

abstract:
  We develop a new class of chaotic inflation models with spontaneously broken
conformal invariance. Observational consequences of a broad class of such
models are stable with respect to strong deformations of the scalar potential.
This universality is a critical phenomenon near the point of enhanced symmetry,
SO(1,1), in case of conformal inflation. It appears because of the exponential
stretching of the moduli space and the resulting exponential flattening of
scalar potentials upon switching from the Jordan frame to the Einstein frame in
this class of models. This result resembles stretching and flattening of
inhomogeneities during inflationary expansion. It has a simple interpretation
in terms of velocity versus rapidity near the Kahler cone in the moduli space,
similar to the light cone of special theory of relativity. This effect makes
inflation possible even in the models with very steep potentials. We describe
conformal and superconformal versions of this cosmological attractor mechanism.


title: Quantum oscillations in Kondo Insulator SmB$_6$

abstract:
  In Kondo insulator samarium hexaboride SmB$_6$, strong correlation and band
hybridization lead to an insulating gap and a diverging resistance at low
temperature. The resistance divergence ends at about 5 Kelvin, a behavior
recently demonstrated to arise from the surface conductance. However, questions
remain whether and where a topological surface state exists. Quantum
oscillations have not been observed to map the Fermi surface. We solve the
problem by resolving the Landau Level quantization and Fermi surface topology
using torque magnetometry. The observed Fermi surface suggests a two
dimensional surface state on the (101) plane. Furthermore, the tracking of the
Landau Levels in the infinite magnetic field limit points to -1/2, which
indicates a 2D Dirac electronic state.


title:
Crystallographic, Electronic, Thermal and Magnetic Properties of
  Single-Crystal SrCo2As2

abstract:
  In tetragonal SrCo2As2 single crystals, inelastic neutron scattering
measurements demonstrated that strong stripe-type antiferromagnetic (AFM)
correlations occur at a temperature T = 5 K [W. Jayasekara et al.,
arXiv:1306.5174] that are the same as in the isostructural AFe2As2 (A = Ca, Sr,
Ba) parent compounds of high-Tc superconductors. This surprising discovery
suggests that SrCo2As2 may also be a good parent compound for high-Tc
superconductivity. Here, structural and thermal expansion, electrical
resistivity rho, angle-resolved photoemission spectroscopy (ARPES), heat
capacity Cp, magnetic susceptibility chi, 75As NMR and neutron diffraction
measurements of SrCo2As2 crystals are reported together with LDA band structure
calculations that shed further light on this fascinating material. The c-axis
thermal expansion coefficient alpha_c is negative from 7 to 300 K, whereas
alpha_a is positive over this T range. The rho(T) shows metallic character. The
ARPES measurements and band theory confirm the metallic character and in
addition show the presence of a flat band near the Fermi energy E_F. The band
calculations exhibit an extremely sharp peak in the density of states D(E_F)
arising from a flat d_{x^2 - y^2} band. A comparison of the Sommerfeld
coefficient of the electronic specific heat with chi(T = 0) suggests the
presence of strong ferromagnetic itinerant spin correlations which on the basis
of the Stoner criterion predicts that SrCo2As2 should be an itinerant
ferromagnet, in conflict with the magnetization data. The chi(T) does have a
large magnitude, but also exhibits a broad maximum at 115 K suggestive of
dynamic short-range AFM spin correlations, in agreement with the neutron
scattering data. The measurements show no evidence for any type of phase
transition between 1.3 and 300 K and we propose that metallic SrCo2As2 has a
gapless quantum spin-liquid ground state.


title: Detecting Topological Phases in Cold Atoms

abstract:
  Chern insulators are band insulators which exhibit a gap in the bulk and
gapless excitations in the edge. Detection of Chern insulators is a serious
challenge in cold atoms since the Hall transport measurements are technically
unrealistic for neutral atoms. By establishing a natural correspondence between
the time-reversal invariant topological insulator and quantum anomalous Hall
system, we show for a class of Chern insulators that the topology can be
determined by only measuring Bloch eigenstates at highly symmetric points of
the Brillouin zone (BZ). Furthermore, we introduce two experimental schemes
including the spin-resolved Bloch oscillation to carry out the measurement.
These schemes are highly feasible under realistic experimental conditions. Our
results may provide a powerful tool to detect topological phases in cold atoms.


title: Euclidean Greedy Drawings of Trees

abstract:
  Greedy embedding (or drawing) is a simple and efficient strategy to route
messages in wireless sensor networks. For each source-destination pair of nodes
s, t in a greedy embedding there is always a neighbor u of s that is closer to
t according to some distance metric. The existence of greedy embeddings in the
Euclidean plane R^2 is known for certain graph classes such as 3-connected
planar graphs. We completely characterize the trees that admit a greedy
embedding in R^2. This answers a question by Angelini et al. (Graph Drawing
2009) and is a further step in characterizing the graphs that admit Euclidean
greedy embeddings.


title:
On graded identities of block-triangular matrices with the grading of Di
  Vincenzo-Vasilovsky

abstract:
  The algebra of $n\times n$ matrices over a field $F$ has a natural
$\mathbb{Z}_n$-grading. Its graded identities have been described by Vasilovsky
who extended a previous work of Di Vincenzo for the algebra of $2\times 2$
matrices. In this paper we study the graded identities of block-triangular
matrices with the grading inherited by the grading of $M_n(F)$. We show that
its graded identities follow from the graded identities of $M_n(F)$ and from
its monomial identities of degree up to $2n-2$. In the case of blocks of sizes
$n-1$ and 1, we give a complete description of its monomial identities, and
exhibit a minimal basis for its $T_{\mathbb{Z}_n}$-ideal.