title: On the origin of >10 GeV photons in gamma-ray burst afterglows

abstract:
  Fermi/LAT has detected long-lasting high-energy photons (>100 MeV) from
gamma-ray bursts (GRBs), with the highest energy photons reaching about 100
GeV. One proposed scenario is that they are produced by high-energy electrons
accelerated in GRB forward shocks via synchrotron radiation. We study the
maximum synchrotron photon energy in this scenario, considering the properties
of the microturbluence magnetic fields behind the shock, as revealed by recent
Particle-in-Cell simulations and theoretical analyses of relativistic
collisionless shocks. Due to the small-scale nature of the micro-turbulent
magnetic field, the Bohm acceleration approximation breaks down at such high
energies. This effect leads to a typical maximum synchrotron photon of a few
GeV at 100 s after the burst and this maximum synchrotron photon energy
decreases quickly with time. We show that the fast decrease of the maximum
synchrotron photon energy leads to a fast decay of the synchrotron flux. The
10-100 GeV photons detected after the prompt phase can not be produced by the
synchrotron mechanism. They could originate from the synchrotron self-Compton
emission of the early afterglow if the circum-burst density is sufficiently
large, or from the external inverse-Compton process in the presence of central
X-ray emission, such as X-ray flares and prompt high-latitude X-ray emission.


title:
GReTA - a novel Global and Recursive Tracking Algorithm in three
  dimensions

abstract:
  Tracking multiple moving targets allows quantitative measure of the dynamic
behavior in systems as diverse as animal groups in biology, turbulence in fluid
dynamics and crowd and traffic control. In three dimensions, tracking several
targets becomes increasingly hard since optical occlusions are very likely,
i.e. two featureless targets frequently overlap for several frames. Occlusions
are particularly frequent in biological groups such as bird flocks, fish
schools, and insect swarms, a fact that has severely limited collective animal
behavior field studies in the past. This paper presents a 3D tracking method
that is robust in the case of severe occlusions. To ensure robustness, we adopt
a global optimization approach that works on all objects and frames at once. To
achieve practicality and scalability, we employ a divide and conquer
formulation, thanks to which the computational complexity of the problem is
reduced by orders of magnitude. We tested our algorithm with synthetic data,
with experimental data of bird flocks and insect swarms and with public
benchmark datasets, and show that our system yields high quality trajectories
for hundreds of moving targets with severe overlap. The results obtained on
very heterogeneous data show the potential applicability of our method to the
most diverse experimental situations.


title:
Direct measurement of the orbital angular momentum mean and variance in
  an arbitrary paraxial optical field

abstract:
  We introduce and experimentally demonstrate a method for measuring at the
same time the mean and the variance of the photonic orbital angular momentum
(OAM) distribution in any paraxial optical field, without passing through the
acquisition of its entire angular momentum spectrum. This method hence enables
one to reduce the infinitely many output ports required in principle to perform
a full OAM spectrum analysis to just two. The mean OAM, in turn, provides
direct access to the average mechanical torque that the optical field in any
light beam is expected to exert on matter, for example in the case of
absorption. Our scheme could also be exploited to weaken the strict alignment
requirements usually imposed for OAM-based free-space communication.


title:
Experimental Demonstration of Robust Bidirectional Quantum Optical
  Communications

abstract:
  We experimentally realized a new method for transmitting quantum information
reliably through paired optical polarization-maintaining (PM) fibers. The
physical setup extends the use of a Mach-Zehnder interferometer, where noises
are canceled through interference. This method can be viewed as an improved
version of the current decohernce-free subspace (DFS) approach in fiber optics.
Furthermore, the setup can be applied bidirectionally, which means that robust
quantum communication can be achieved from both ends. To rigorously quantify
the amount of quantum information transferred, optical fibers are analyzed with
the tools developed in quantum communication theory. These results not only
suggests a practical means for protecting classical and quantum information
through optical fibers, but also provides a new physical platform for enriching
the structure of the quantum communication theory.


title: The covariant, time-dependent Aharonov-Bohm Effect

abstract:
  We discuss two possible covariant generalizations of the Aharonov-Bohm effect
- one expression in terms of the space-time line integral of the four-vector
potential and the other expression in terms of the space-time "area" integral
of the electric and magnetic fields written in terms of the Faraday 2-form.
These expressions allow one to calculate the Aharonov-Bohm effect for
time-dependent situations. In particular, we use these expressions to study the
case of an infinite solenoid with a time varying flux and find that the phase
shift is zero due to a cancellation of the Aharonov-Bohm phase shift with a
phase shift coming from the Lorentz force associated with the electric field,
${\bf E} = - \partial_t {\bf A}$, outside the solenoid. This result may already
have been confirmed experimentally.


title:
Nonmagnetic Impurity Effect of the S=1/2 Spin Ladder System
  (pipdH)_2Cu_{1-x}Zn_xBr_4

abstract:
  We report the synthesis and the magnetic susceptibility of
(pipdH)2Cu1-xZnxBr4, which is a nonmagnetic impurity-doped S=1/2 spin ladder
system. The samples were synthesized from a solution by using a slow
evaporation method. Samples were confirmed to be in a single phase and to have
the same crystal structure as the pure system (pipdH)2CuBr4 by using X-ray
diffraction measurements. To check the magnetic properties, we performed
magnetic susceptibility and magnetization measurements with a SQUID
magnetometer. A plot of the inverse magnetic susceptibility indicates the
presence of dominant antiferromagnetic coupling. The magnetic susceptibility
shows a broad maximum due to low dimensionality and a spin gap behavior related
to the two-leg spin ladder at low temperature. The spin gap and the Curie
constants of Zn-doped samples, as estimated from an analysis of the magnetic
susceptibility, monotonically decrease as the Zn concentration decreases. A
nonmagnetic impurity of S=1/2 spin ladder system affects the spin gap.


title: Treatment of a System with Explicitly Broken Gauge Symmetries

abstract:
  A system in which the free part of the action possesses a gauge symmetry that
is not respected by the interacting part presents problems when quantized. We
illustrate how the Dirac constraint formalism can be used to address this
difficulty by considering an antisymmetric tensor field interacting with a
spinor field.


title: Variational Formulation of Curved Beams in Global Coordinates

abstract:
  In this paper we derive a variational formulation for a linear curved beam
which is natively expressed in global Cartesian coordinates. During derivation
the beam midline is assumed to be implicitly described by a vector distance
function which eliminates the need for local coordinates. The only geometrical
information appearing in the final expressions for the governing equations is
the tangential direction, and thus there is no need to introduce normal
directions along the curve. As a consequence zero or discontinuous curvature,
for example at inflection points, pose no difficulty in this formulation.
Kinematic assumptions encompassing both Timoshenko and Euler--Bernoulli beam
theories are considered.
  With the exception of truly three dimensional formulations, models for curved
beams found in literature are typically derived in the Frenet frame defined by
the geometry of the beam midline. While it is intuitive to formulate curved
beam models in these local coordinates, the Frenet frame suffers from ambiguity
and sudden changes of orientation in straight sections of the beam.
  Based on the variational formulation we implement finite element models using
global Cartesian degrees of freedom and discuss curvature coupling effects and
locking. Numerical comparisons with classical solutions for both straight and
curved cantilever beams under a tip load are given, as well as numerical
examples illustrating curvature coupling effects.


title: Willingness Optimization for Social Group Activity

abstract:
  Studies show that a person is willing to join a social group activity if the
activity is interesting, and if some close friends also join the activity as
companions. The literature has demonstrated that the interests of a person and
the social tightness among friends can be effectively derived and mined from
social networking websites. However, even with the above two kinds of
information widely available, social group activities still need to be
coordinated manually, and the process is tedious and time-consuming for users,
especially for a large social group activity, due to complications of social
connectivity and the diversity of possible interests among friends. To address
the above important need, this paper proposes to automatically select and
recommend potential attendees of a social group activity, which could be very
useful for social networking websites as a value-added service. We first
formulate a new problem, named Willingness mAximization for Social grOup
(WASO). This paper points out that the solution obtained by a greedy algorithm
is likely to be trapped in a local optimal solution. Thus, we design a new
randomized algorithm to effectively and efficiently solve the problem. Given
the available computational budgets, the proposed algorithm is able to
optimally allocate the resources and find a solution with an approximation
ratio. We implement the proposed algorithm in Facebook, and the user study
demonstrates that social groups obtained by the proposed algorithm
significantly outperform the solutions manually configured by users.


title:
Hochster duality in derived categories and point-free reconstruction of
  schemes

abstract:
  For a commutative ring $R$, we exploit localization techniques and point-free
topology to give an explicit realization of both the Zariski frame of $R$ (the
frame of radical ideals in $R$) and its Hochster dual frame, as lattices in the
poset of localizing subcategories of the unbounded derived category $D(R)$.
This yields new conceptual proofs of the classical theorems of Hopkins-Neeman
and Thomason. Next we revisit and simplify Balmer's theory of spectra and
supports for tensor triangulated categories from the viewpoint of frames and
Hochster duality. Finally we exploit our results to show how a coherent scheme
$(X,\mathcal{O}_X)$ can be reconstructed from the tensor triangulated structure
of its derived category of perfect complexes.


title:
Can Excitonic Mechanism Contribute Significantly to Superconducting
  Pairing in Quasi 1-D Systems?

abstract:
  We have revisited Cooper's one pair problem of calculating the binding energy
for two electrons, experiencing an attractive interaction near the Fermi
surface, in case of quasi one dimensional lattice system. Though it is a
generalized formalism, we have chosen two materials viz., (TMTSF)2ClO4 and
(TMTSF)2AsF6 as examples. Some of their electronic and optical features are
used for calculations and validity this formalism is checked too for these
materials. It is generally believed that spin density fluctuation mechanism is
very strong candidate for the occurrence of superconductivity in these quasi
one dimensional materials. We have attempted to invoke another type of
electronic mechanism viz., charge transfer Exciton mechanism to explore if some
substantial contribution for attractive coupling can be generated. This
mechanism may be plausible in these types of organic materials where ionicity
and co-valency co-exist. Making use of the experimental results for optical
absorption spectra corresponding to above materials, we extracted the relevant
parameters for incorporating in the binding energy calculation. Our calculation
shows that Fermionic pair formation is possible for all the three cases viz.,
(1) less than half filled, (2) half filled and (3) more than half filled.


title: An accurate tool for the fast generation of dark matter halo catalogs

abstract:
  We present a new parallel implementation of the PINpointing Orbit
Crossing-Collapsed HIerarchical Objects (PINOCCHIO) algorithm, a quick tool,
based on Lagrangian Perturbation Theory, for the hierarchical build-up of Dark
Matter halos in cosmological volumes. To assess its ability to predict halo
correlations on large scales, we compare its results with those of an N-body
simulation of a 3 Gpc/h box sampled with 2048^3 particles taken from the MICE
suite, matching the same seeds for the initial conditions. Thanks to the FFTW
libraries and to the relatively simple design, the code shows very good scaling
properties. The CPU time required by PINOCCHIO is a tiny fraction (~1/2000) of
that required by the MICE simulation. Varying some of PINOCCHIO numerical
parameters allows one to produce a universal mass function that lies in the
range allowed by published fits, although it underestimates the MICE mass
function of FoF halos in the high mass tail. We compare the matter-halo and the
halo-halo power spectra with those of the MICE simulation and find that these
2-point statistics are well recovered on large scales. In particular, when
catalogs are matched in number density, agreement within ten per cent is
achieved for the halo power spectrum. At scales k>0.1 h/Mpc, the inaccuracy of
the Zel'dovich approximation in locating halo positions causes an underestimate
of the power spectrum that can be modeled as a Gaussian factor with a damping
scale of d=3 Mpc/h at z=0, decreasing at higher redshift. Finally, a remarkable
match is obtained for the reduced halo bispectrum, showing a good description
of nonlinear halo bias. Our results demonstrate the potential of PINOCCHIO as
an accurate and flexible tool for generating large ensembles of mock galaxy
surveys, with interesting applications for the analysis of large galaxy
redshift surveys.


title:
Entanglement classes of permutation-symmetric qudit states: symmetric
  operations suffice

abstract:
  We analyse entanglement classes for permutation-symmetric states for n qudits
(i.e. d-level systems), with respect to local unitary operations
(LU-equivalence) and stochastic local operations and classical communication
(SLOCC equivalence). In both cases, we show that the search can be restricted
to operations where the same local operation acts on all qudits, and we provide
an explicit construction for it. Stabilizers of states in the form of
one-particle operations preserving permutation symmetry are shown to provide a
coarse-grained classification of entanglement classes. We prove that the Jordan
form of such one-particle operator is a SLOCC invariant. We find, as
representatives of those classes, a discrete set of entangled states that
generalize the GHZ and W state for the many-particle qudit case. In the later
case, we introduce "excitation states" as a natural generalization of the W
state for d>2.


title: Time-Delayed Feedback Control Design Beyond the Odd Number Limitation

abstract:
  We present an algorithm for a time-delayed feedback control design to
stabilize periodic orbits with an odd number of positive Floquet exponents in
autonomous systems. Due to the so-called odd number theorem such orbits have
been considered as uncontrollable by time-delayed feedback methods. However,
this theorem has been refuted by a counterexample and recently a corrected
version of the theorem has been proved. In our algorithm, the control matrix is
designed using a relationship between Floquet multipliers of the systems
controlled by time-delayed and proportional feedback. The efficacy of the
algorithm is demonstrated with the Lorenz and Chua systems.


title:
New equations of state based on the liquid drop model of heavy nuclei
  and quantum approach to light nuclei for core-collapse supernova simulations

abstract:
  We construct new equations of state for baryons at sub-nuclear densities for
the use in core-collapse simulations of massive stars. The abundance of various
nuclei is obtained together with thermodynamic quantities. A model free energy
is constructed, based on the relativistic mean field theory for nucleons and
the mass formula for nuclei with the proton number up to ~ 1000. The
formulation is an extension of the previous model, in which we adopted the
liquid drop model to all nuclei under the nuclear statistical equilibrium. We
reformulate the new liquid drop model so that the temperature dependences of
bulk energies could be taken into account. Furthermore, we extend the region in
the nuclear chart, in which shell affects are included, by using theoretical
mass data in addition to experimental ones. We also adopt a quantum theoretical
mass evaluation of light nuclei, which incorporates the Pauli- and self-energy
shifts that are not included in the ordinary liquid drop model. The pasta
phases for heavy nuclei are taken into account in the same way as in the
previous model. We find that the abundances of heavy nuclei are modified by the
shell effects of nuclei and temperature dependence of bulk energies. These
changes may have an important effect on the rates of electron captures and
coherent neutrino scatterings on nuclei in supernova cores. The abundances of
light nuclei are also modified by the new mass evaluation, which may affect the
heating and cooling rates of supernova cores and shocked envelopes.


title:
The radio structure of 3C 316, a galaxy with double-peaked narrow
  optical emission lines

abstract:
  The galaxy 3C\,316 is the brightest in the radio band among the
optically-selected candidates exhibiting double-peaked narrow optical emission
lines. Observations with the Very Large Array (VLA), Multi-Element Remotely
Linked Interferometer Network (e-MERLIN), and the European VLBI Network (EVN)
at 5\,GHz have been used to study the radio structure of the source in order to
determine the nature of the nuclear components and to determine the presence of
radio cores. The e-MERLIN image of 3C 316 reveals a collimated coherent
east-west emission structure with a total extent of about 3 kpc. The EVN image
shows seven discrete compact knots on an S-shaped line. However, none of these
knots could be unambiguously identified as an AGN core. The observations
suggest that the majority of the radio structure belongs to a powerful radio
AGN, whose physical size and radio spectrum classify it as a compact
steep-spectrum source. Given the complex radio structure with radio blobs and
knots, the possibility of a kpc-separation dual AGN cannot be excluded if the
secondary is either a naked core or radio quiet.


title:
The influence of inelastic neutrino reactions with light nuclei on the
  standing accretion shock instability in core-collapse supernovae

abstract:
  We perform numerical experiments to investigate the influence of inelastic
neutrino reactions with light nuclei on the standing accretion shock
instability (SASI). The time evolution of shock waves is calculated with a
simple light-bulb approximation for the neutrino transport and a multi-nuclei
equation of state. The neutrino absorptions and inelastic interactions with
deuterons, tritons, helions and alpha particles are taken into account in the
hydrodynamical simulations in addition to the ordinary charged-current
interactions with nucleons. Axial symmetry is assumed but no equatorial
symmetry is imposed. We show that the heating rates of deuterons reach as high
as 10% of those of nucleons around the bottom of the gain region. On the other
hand, alpha particles are heated near the shock wave, which is important when
the shock wave expands and the density and temperature of matter become low. It
is also found that the models with heating by light nuclei have different
evolutions from those without it in the non-linear phase of SASI. This results
is because matter in the gain region has a varying density and temperature and
there appear sub-regions that are locally rich in deuterons and alpha
particles. Although the light nuclei are never dominant heating sources and
they work favorably for shock revival in some cases and unfavorably in other
cases, they are non-negligible and warrant further investigation.


title: A Study of Three-Dimensional Paracontact $(\kappa ,\mu ,\nu) $-SPACES

abstract:
  This paper is a study of three-dimensional paracontact metric
(\k{appa},{\mu},{\nu})-manifolds. Three dimensional paracontact metric
manifolds whose Reeb vector field {\xi} is harmonic are characterized. We focus
on some curvature properties by considering the class of paracontact metric
(\k{appa},{\mu},{\nu})-manifolds under a condition which is given at Definition
3.1. We study properties of such manifolds according to the cases \k{appa}>-1,
\k{appa}=-1, \k{appa}<-1 and construct new examples of such manifolds for each
case.


title: Adiabatic quantum pumping of chiral Majorana fermions

abstract:
  We investigate adiabatic quantum pumping of chiral Majorana states in a
system composed of two Mach--Zehnder type interferometers coupled via a quantum
point contact. The pumped current is generated by periodic modulation of the
phases accumulated by traveling around each interferometer. Using scattering
matrix formalism we show that the pumped current reveals a definite signature
of the chiral nature of the Majorana states involved in transport in this
geometry. Furthermore, by tuning the coupling between the two interferometers
the pump can operate in a regime where finite pumped current and zero
two-terminal conductance is expected.


title: Massive spin-2 particle from a rank-2 tensor

abstract:
  Here we obtain all possible second-order theories for a rank-2 tensor which
describe a massive spin-2 particle. We start with a general second-order
Lagrangian with ten real parameters. The absence of lower spin modes and the
existence of two local field redefinitions leads us to only one free parameter.
The solutions split into three one-parameter classes according to the local
symmetries of the massless limit. In the class which contains the usual massive
Fierz-Pauli theory, the subset of spin-1 massless symmetries is maximal. In
another class where the subset of spin-0 symmetries is maximal, the massless
theory is invariant under Weyl transformations and the mass term does not need
to fit in the form of the Fierz-Pauli mass term. In the remaining third class
neither the spin-1 nor the spin-0 symmetry is maximal and we have a new family
of spin-2 massive theories.


title: A solution to the Pyjama Problem

abstract:
  The "pyjama stripe" is the subset of $\mathbb{R}^2$ consisting of a vertical
strip of width $2 \varepsilon$ around every integer $x$-coordinate. The "pyjama
problem" asks whether finitely many rotations of the pyjama stripe around the
origin can cover the plane.
  The purpose of this paper is to answer this question in the affirmative, for
all positive $\varepsilon$. The problem is reduced to a statement closely
related to Furstenberg's $\times 2,\, \times 3$ Theorem from topological
dynamics, and is proved by analogy with that result.


title:
Observation of nitrogen vacancy photoluminescence from an optically
  levitated nanodiamond

abstract:
  We present the first evidence of nitrogen vacancy (NV) photoluminescence from
a nanodiamond suspended in a free-space optical dipole trap at atmospheric
pressure. The photoluminescence rates are shown to decrease with increasing
trap laser power, but are inconsistent with a thermal quenching process. For a
continuous-wave trap, the neutral charge state (NV$^0$) appears to be
suppressed. Chopping the trap laser yields higher total count rates and results
in a mixture of both NV$^0$ and the negative charge state (NV$^-$).


title:
Coherent internal state transfer by three-photon STIRAP-like scheme for
  many-atom samples

abstract:
  A STIRAP-like scheme is proposed to exploit a three-photon resonance taking
place in alkaline-earth-metal ions. This scheme is designed for state transfer
between the two fine structure components of the metastable D-state which are
two excited states that can serve as optical or THz qu-bit. The advantage of a
coherent three-photon process compared to two-photon STIRAP lies in the
possibility of exact cancellation of the first order Doppler shift which opens
the way for an application to a sample composed of many ions. The transfer
efficiency and its dependence with experimental parameters are analyzed by
numerical simulations. This efficiency is shown to reach a fidelity as high as
$(1-8.10^{-5})$ with realistic parameters. The scheme is also extended to the
synthesis of a linear combination of three stable or metastable states.


title: Constrained caloric curves and phase transition for hot nuclei

abstract:
  Simulations based on experimental data obtained from multifragmenting
quasi-fused nuclei produced in central $^{129}$Xe + $^{nat}$Sn collisions have
been used to deduce event by event freeze-out properties in the thermal
excitation energy range 4-12 AMeV [Nucl. Phys. A809 (2008) 111]. From these
properties and the temperatures deduced from proton transverse momentum
fluctuations, constrained caloric curves have been built. At constant average
volumes caloric curves exhibit a monotonic behaviour whereas for constrained
pressures a backbending is observed. Such results support the existence of a
first order phase transition for hot nuclei.


title: Stabilit\'e des sous-alg\`ebres paraboliques de so(n)

abstract:
  Let $\mathbb{K}$ be an algebraically closed field of characteristic 0. A
finite dimensional Lie algebra $\mathfrak{g}$ over $\mathbb{K}$ is said to be
stable if there exists a linear form $g\in\mathfrak{g}^{*}$ and a Zariski open
subset in $\mathfrak{g}^{*}$ containing $g$ in which all elements have their
stabilizers conjugated under the connected adjoint group. It is well known that
any quasi-reductive Lie algebra is stable. However, there are stable Lie
algebras which are not quasi-reductive. This raises the question, if for some
particular class of non-reductive Lie algebras, there is equivalence between
stability and quasi-reductivity. In particular, it was conjectured by Panyushev
that these two notions are equivalent for biparabolic subalgebras of a
reductive Lie algebra. In this paper, we prove this conjecture for parabolic
subalgebras of orthogonal Lie algebras and we answer positively to this
question for certain Lie algebras which stabilize an alternating bilinear form
of maximal rank and a flag in generic position.


title:
Phase-stable source of polarization-entangled photons in a linear
  double-pass configuration

abstract:
  We demonstrate a compact, robust, and highly efficient source of
polarization-entangled photons, based on linear bi-directional down-conversion
in a novel 'folded sandwich' configuration. Bi-directionally pumping a single
periodically poled KTiOPO$_4$ (ppKTP) crystal with a 405-nm laser diode, we
generate entangled photon pairs at the non-degenerate wavelengths 784 nm
(signal) and 839 nm (idler), and achieve an unprecedented detection rate of
11.8 kcps for 10.4 $\mu$W of pump power (1.1 million pairs / mW), in a 2.9-nm
bandwidth, while maintaining a very high two-photon entanglement quality, with
a Bell-state fidelity of $99.3\pm0.3$%.


title:
A Method for Visuo-Spatial Classification of Freehand Shapes Freely
  Sketched

abstract:
  We present the principle and the main steps of a new method for the
visuo-spatial analysis of geometrical sketches recorded online. Visuo-spatial
analysis is a necessary step for multi-level analysis. Multi-level analysis
simultaneously allows classification, comparison or clustering of the
constituent parts of a pattern according to their visuo-spatial properties,
their procedural strategies, their structural or temporal parameters, or any
combination of two or more of those parameters. The first results provided by
this method concern the comparison of sketches to some perfect patterns of
simple geometrical figures and the measure of dissimilarity between real
sketches. The mean rates of good decision higher than 95% obtained are
promising in both cases.


title: Persisting topological order via geometric frustration

abstract:
  We introduce a toric code model on the dice lattice which is exactly solvable
and displays topological order at zero temperature. In the presence of a
magnetic field, the flux dynamics is mapped to the highly frustrated transverse
field Ising model on the kagome lattice. This correspondence suggests an
intriguing disorder by disorder phenomenon in a topologically ordered system
implying that the topological order is extremely robust due to the geometric
frustration. Furthermore, a connection between fully frustrated transverse
field Ising models and topologically ordered systems is demonstrated which
opens an exciting physical playground due to the interplay of topological
quantum order and geometric frustration.


title:
Ultrathin Nanostructured Metals for Highly Transmissive Plasmonic
  Subtractive Color Filters

abstract:
  Plasmonic color filters employing a single optically-thick nanostructured
metal layer have recently generated considerable interest as an alternative to
colorant-based color filtering technologies, due to their reliability, ease of
fabrication, high color tunability. However, their relatively low transmission
efficiency (~30%) is an important challenge that needs to be addressed. The
present work reports, for the first time, a novel plasmonic subtractive color
filtering scheme that exploits the counter-intuitive phenomenon of
extraordinary low transmission (ELT) through an ultrathin nanostructured metal
film. This approach relies on a fundamentally different color filtering
mechanism than that of exsiting plasmonic additive color filters, and achieves
unusually high transmission efficiencies of 60~70% for simple architectures.
Furthermore, owing to short-range interactions of surface plasmon polaritons at
ELT resonances, our design offers high spatial resolution color filtering with
compact pixel size close to the optical diffraction limit (~{\lambda}/2),
creating solid applications ranging from imaging sensors to color displays.


title:
An initial study of mesons and baryons containing strange quarks with
  GlueX

abstract:
  The primary motivation of the GlueX experiment is to search for and
ultimately study the pattern of gluonic excitations in the meson spectrum
produced in $\gamma p$ collisions. Recent lattice QCD calculations predict a
rich spectrum of hybrid mesons that have both exotic and non-exotic $J^{PC}$,
corresponding to $q\bar{q}$ states ($q=u,$ $d,$ or $s$) coupled with a gluonic
field. A thorough study of the hybrid spectrum, including the identification of
the isovector triplet, with charges 0 and $\pm1$, and both isoscalar members,
$|s\bar{s}\ >$ and $|u\bar{u}\ > + |d\bar{d}\ >$, for each predicted hybrid
combination of $J^{PC}$, may only be achieved by conducting a systematic
amplitude analysis of many different hadronic final states. Detailed studies of
the performance of the \gx detector have indicated that identification of
particular final states with kaons is possible using the baseline detector
configuration. The efficiency of kaon detection coupled with the relatively
lower production cross section for particles containing hidden strangeness will
require a high intensity run in order for analyses of such states to be
feasible. We propose to collect a total of 200 days of physics analysis data at
an average intensity of $5\times 10^7$ tagged photons on target per second.
This data sample will provide an order of magnitude statistical improvement
over the initial GlueX running, which will allow us to begin a program of
studying mesons and baryons containing strange quarks. In addition, the
increased intensity will permit us to study reactions that may have been
statistically limited in the initial phases of GlueX. Overall, this will lead
to a significant increase in the potential for \gx to make key experimental
advances in our knowledge of hybrid mesons and excited $\Xi$ baryons.


title:
Pseudospin symmetry in single particle resonances in spherical square
  wells

abstract:
  The pseudospin symmetry (PSS) has been studied extensively for bound states.
Recently we justified rigorously that the PSS in single particle resonant
states is exactly conserved when the attractive scalar and repulsive vector
potentials of the Dirac Hamiltonian have the same magnitude but opposite sign
[PRL 109, 072501 (2012)]. To understand more deeply the PSS, we focus on
several issues related to the exact conservation and breaking mechanism of the
PSS in single particle resonances. In particular, we are interested in how the
energy and width splittings of PS partners depend on the depth of the scalar
and vector potentials. We investigate the asymptotic behaviors of radial Dirac
wave functions. Spherical square well potentials are employed in which the PSS
breaking part in the Jost function can be well isolated. By examining the zeros
of Jost functions corresponding to small components of the radial Dirac wave
functions, general properties of the PSS are analyzed. By examining the Jost
function, the occurrence of intruder orbitals is explained and it is possible
to trace continuously the PSS partners from the PSS limit to the case with a
finite potential depth. The dependence of the PSS in resonances as well as in
bound states on the potential depth is investigated systematically. We find a
threshold effect in the energy splitting and an anomaly in the width splitting
of pseudospin partners when the depth of the single particle potential varies
from zero to a finite value. The conservation and the breaking of the PSS in
resonant states and bound states share some similar properties. The appearance
of intruder states can be explained by examining the zeros of Jost functions.
Origins of the threshold effect in the energy splitting and the anomaly in the
width splitting of PS partners, together with many other problems, are still
open and should be further investigated.


title:
Constant-Envelope Multi-User Precoding for Frequency-Selective Massive
  MIMO Systems

abstract:
  We consider downlink precoding in a frequency-selective multi-user Massive
MIMO system with highly efficient but non-linear power amplifiers at the base
station (BS). A low-complexity precoding algorithm is proposed, which generates
constant-envelope (CE) signals at each BS antenna. To achieve a desired
per-user information rate, the extra total transmit power required under the
per-antenna CE constraint when compared to the commonly used less stringent
total average transmit power constraint, is small.


title:
Invariant Criterion for the Design of Multiple Beam Profile Emittance
  and Twiss Parameters Measurement Sections

abstract:
  We introduce and give examples of applications of an optimality criterion
which can be used for the design and comparison of multiple beam profile
emittance and Twiss parameters measurement sections and which is independent
from the position of the reconstruction point.


title: The optimal fourth moment theorem

abstract:
  We compute the exact rates of convergence in total variation associated with
the 'fourth moment theorem' by Nualart and Peccati (2005), stating that a
sequence of random variables living in a fixed Wiener chaos verifies a central
limit theorem (CLT) if and only if the sequence of the corresponding fourth
cumulants converges to zero. We also provide an explicit illustration based on
the Breuer-Major CLT for Gaussian-subordinated random sequences.


title:
Optimal Twiss Parameters for Emittance Measurement in Periodic Transport
  Channels

abstract:
  Our objective in this paper is to describe an invariant optimality criterion
and then apply it to the procedure of emittance measurement in periodic beam
transport channels.


title:
On the finite dimensional approximation of the Kuratowski-embedding for
  compact manifolds

abstract:
  In the proof of his systolic inequality, Gromov uses an isometric embedding
of a Riemannian manifold M into the Banach space of bounded functions on M, the
so-called Kuratowski-embedding. Subsequently, it was shown by different authors
that the Kuratowski embedding can be approximated by bi-Lipschitz embeddings
into finite-dimensional Banach spaces. We give a detailed proof for the
existence of such finite-dimensional approximations along the lines suggested
by Larry Guth and go on to discuss quantitative aspects of the problem,
establishing for the dimension of the Banach space a bound which depends on
curvature properties of the manifold.


title: Standard Model Higgs Boson Searches at the Tevatron

abstract:
  Updated Standard Model Higgs boson search results from the Tevatron
experiments are presented. We focus on the updated CDF MET+bb result, where a
significant shift in observed limits is explained. For the Tevatron
combinations, upper limits at 95% credibility level and best-fit values for the
Higgs boson cross section times branching ratio are presented. We also place
constraints on the Higgs couplings to fermions and electroweak vector bosons.
All results are consistent with the existence of a Standard Model Higgs boson
with a mass of 125 GeV/c2, and with the Standard-Model predictions associated
with that assumption.


title: The average signature of graph links

abstract:
  We compute the average Tristram---Levine signature of any graph link with
positive weights in a three sphere, generalizing the results of Kirby and
Melvin. The main tools are the Neumann's algorithm for computing the
equivariant signatures of graph links and the Reciprocity Law for Dedekind
sums.


title: Relations between Projected Emittances and Eigenemittances

abstract:
  We give necessary and sufficient conditions that two sets of positive real
numbers must satisfy in order to be realizable as eigenemittances and projected
emittances of a beam matrix. The information provided by these conditions sets
limits on what one can to achieve when designing a beam line to perform
advanced emittance manipulations.


title:
Thermal analysis and cooling structure design of the primary collimator
  in CSNS/RCS

abstract:
  The rapid cycling synchrotron (RCS) of the China Spallation Neutron Source
(CSNS) is a high intensity proton ring with beam power of 100 kW. In order to
control the residual activation to meet the requirements of hands-on
maintenance, a two-stage collimation system has been designed for the RCS. The
collimation system consists of one primary collimator made of thin metal to
scatter the beam and four secondary collimators as absorbers. Thermal analysis
is an important aspect in evaluating the reliability of the collimation system.
The calculation of the temperature distribution and thermal stress of the
primary collimator with different materials is carried out by using ANSYS code.
In order to control the temperature rise and thermal stress of the primary
collimator to a reasonable level, an air cooling structure is intended to be
used. The mechanical design of the cooling structure is presented, and the
cooling effciency with different chin numbers and wind velocity is also
analyzed. Finally, the fatigue lifetime of the collimator under thermal shocks
is estimated.


title: Entropy-generated power and its efficiency

abstract:
  We propose a simple model for a motor that generates mechanical motion by
exploiting an entropic force arising from the topology of the underlying phase
space. We show that the generation of mechanical forces in our system is
surprisingly robust to local changes in kinetic and topological parameters.
Furthermore, we find that the efficiency at maximum power may show
discontinuities.


title:
Probabilistic Constructions of Computable Objects and a Computable
  Version of Lov\'asz Local Lemma

abstract:
  A nonconstructive proof can be used to prove the existence of an object with
some properties without providing an explicit example of such an object. A
special case is a probabilistic proof where we show that an object with
required properties appears with some positive probability in some random
process. Can we use such arguments to prove the existence of a computable
infinite object? Sometimes yes: following [8], we show how the notion of a
layerwise computable mapping can be used to prove a computable version of
Lov\'asz local lemma. (A survey of Moser-Tardos proof is included to make the
paper self-contained.)


title:
High-Resolution Correlation Spectroscopy of 13C Spins Near a
  Nitrogen-Vacancy Center in Diamond

abstract:
  Spin complexes comprising the nitrogen-vacancy (NV) center and neighboring
spins are being considered as a building block for a new generation of
spintronic and quantum information processing devices. Because assembling
identical spin clusters is difficult, new strategies are in order to determine
individual node structures with the highest precision. Here we use a pulse
protocol to monitor the time evolution of the 13C ensemble in the vicinity of a
NV center. We observe long-lived time correlations in the nuclear spin
dynamics, limited by NV spin-lattice relaxation. We use the host 14N spin as a
quantum register, and demonstrate that hyperfine-shifted resonances can be
separated upon proper NV initialization. Intriguingly, we find that the
amplitude of the correlation signal exhibits a sharp dependence on the applied
magnetic field. We discuss this observation in the context of the
quantum-to-classical transition proposed recently to explain the field
dependence of the spin cluster dynamics.


title: Shannon capacity of nonlinear regenerative channels

abstract:
  We compute Shannon capacity of nonlinear channels with regenerative elements.
Conditions are found under which capacity of such nonlinear channels is higher
than the Shannon capacity of the classical linear additive white Gaussian noise
channel. We develop a general scheme for designing the proposed channels and
apply it to the particular nonlinear sine-mapping. The upper bound for
regeneration efficiency is found and the asymptotic behavior of the capacity in
the saturation regime is derived.


title:
X-ray, optical and infrared investigation of the candidate Supergiant
  Fast X-ray Transient IGR J18462-0223

abstract:
  We report on a broad-band X-ray study (0.5-60 keV) of the poorly known
candidate Supergiant Fast X-ray Transient (SFXT) IGR J18462-0223, and on
optical and near-infrared (NIR) followup observations of field objects. The
out-of-outburst X-ray state has been investigated for the first time with
archival INTEGRAL/IBIS, ASCA, Chandra and Swift/XRT observations. This allowed
us to place stringent 3 sigma upper limits on the soft (0.5-10 keV) and hard
(18-60 keV) X-ray emission of 2.9x10^-13 erg cm^-2 s^-1 and 8x10^-12 erg cm^-2
s^-1, respectively; the source was also detected during an intermediate soft
X-ray state with flux equal to 1.6x10^-11 erg cm^-2 s^-1 (0.5-10 keV). In
addition, we report on the INTEGRAL/IBIS discovery of three fast hard X-ray
flares (18-60 keV) having a duration in the range 1-12 hours: the flaring
behavior was also investigated in soft X-rays (3-10 keV) with archival
INTEGRAL/JEM-X observations. The duty cycle (1.2%) and the dynamic ranges (>
1,380 and > 190 in the energy bands 0.5-10 keV and 18-60 keV, respectively)
were measured for the first time. Archival UKIDSS JHK NIR data, together with
our deep R-band imaging of the field, unveiled a single, very red object inside
the intersection of the Swift/XRT and XMM-Newton error circles: this source has
optical/NIR photometric properties compatible with a very heavily absorbed blue
supergiant located at about 11 kpc, thus being a strong candidate counterpart
for IGR J18462-0223. NIR spectroscopy is advised to confirm the association.
Finally, a hint of a possible orbital period was found at about 2.13 days. If
confirmed by further studies, this would make IGR J18462-0223 the SFXT with the
shortest orbital period among the currently known systems.


title: Parton Physics on Euclidean Lattice

abstract:
  I show that the parton physics related to correlations of quarks and gluons
on the light-cone can be studied through the matrix elements of
frame-dependent, equal-time correlators in the large momentum limit. This
observation allows practical calculations of parton properties on an Euclidean
lattice. As an example, I demonstrate how to recover the leading-twist quark
distribution by boosting an equal-time correlator to a large momentum.


title: Static vacuum Einstein metrics on bounded domains

abstract:
  We study the existence and uniqueness of solutions to the static vacuum
Einstein equations in bounded domains, satisfying the Bartnik boundary
conditions of prescribed metric and mean curvature on the boundary.


title:
On the Galois-module structure of polydifferentials of Subrao curves,
  modular and integral representation theory

abstract:
  We study the Galois-module structure of polydifferentials on Mumford curves,
defined over a field of positive charactersitic. We give the complete structure
for the Subrao curves using the theory of harmonic cocycles.


title: Low Sensitivity Option for Transverse Optics of the FLASH Linac at DESY

abstract:
  The aim of the FLASH linac is to create electron bunches of small transverse
emittance and high current for the free electron laser facility FLASH at DESY.
Available operational experience indicates that in order to optimize SASE
signal at different wavelengths or to fine-tune the FEL wavelength, empirical
adjustment of the machine parameters is required and, therefore, the
sensitivity of the beamline to small changes in the beam energy and in the
magnet settings becomes one of the important issues which affects both, the
final performance and the reproducibility of the results after breaks in
operation. In this article the transverse optics of the FLASH beamline with low
sensitivity to changes in beam energy and quadrupole settings is presented.
This optics is in operation since spring 2006 and has shown a superior
performance with respect to the previous setup of the transverse focusing.


title:
Polynomial time quantum algorithms for certain bivariate hidden
  polynomial problems

abstract:
  We present a new method for solving the hidden polynomial graph problem
(HPGP) which is a special case of the hidden polynomial problem (HPP). The new
approach yields an efficient quantum algorithm for the bivariate HPGP even when
the input consists of several level set superpositions, a more difficult
version of the problem than the one where the input is given by an oracle. For
constant degree, the algorithm is polylogarithmic in the size of the base
field. We also apply the results to give an efficient quantum algorithm for the
oracle version of the HPP for an interesting family of bivariate hidden
functions. This family includes diagonal quadratic forms and elliptic curves.


title: Post-Linac Collimation System for the European XFEL

abstract:
  In this article we give an overview of the the post-linac collimation system
for the European X-Ray Free-Electron Laser (XFEL) Facility with main emphasis
on lattice and optics design.


title: Reply to Professor Yehia comments arXiv:1305.0026

abstract: This is a reply to Professor Yehia Comments in arXiv:1305.0026


title:
Multi-criteria optimization methods in radiation therapy planning: a
  review of technologies and directions

abstract:
  We review the field of multi-criteria optimization for radiation therapy
treatment planning. Special attention is given to the technique known as Pareto
surface navigation, which allows physicians and treatment planners to
interactively navigate through treatment planning options to get an
understanding of the tradeoffs (dose to the target versus over-dosing of
important nearby organs) involved in each patient's plan. We also describe goal
programming and prioritized optimization, two other methods designed to handle
multiple conflicting objectives. Issues related to nonconvexities, both in
terms of dosimetric goals and the fact that the mapping from controllable
hardware parameters to patient doses is usually nonconvex, are discussed at
length since nonconvexities have a large impact on practical solution
techniques for Pareto surface construction and navigation. A general planning
strategy is recommended which handles the issue of nonconvexity by first
finding an ideal Pareto surface with radiation delivered from many preset
angles. This can be cast as a convex optimization problem. Once a high quality
solution is selected from the Pareto surface, a sparse version (which can mean
fewer beams, fewer segments, less leaf travel for arc therapy techniques, etc.)
is obtained using an appropriate sparsification heuristic. We end by discussing
issues of efficiency regarding the planning and the delivery of radiation
therapy.


title:
Two Cell Repetitive Achromats and Four Cell Achromats Based on Mirror
  Symmetry

abstract:
  In this article we introduce a group-theoretical point of view for the design
of magnetic optical achromats based on symmetry. As examples we use two-cell
repetitive achromats and four-cell achromats employing mirror symmetry.


title:
Renormalization of vacuum expectation values in spontaneously broken
  gauge theories

abstract:
  We compute one-loop and two-loop beta-functions for vacuum expectation values
(VEVs) in gauge theories. In R_xi gauge the VEVs renormalize differently from
the respective scalar fields. We focus particularly on the origin and behavior
of this difference and show that it can be interpreted as the anomalous
dimension of a certain scalar background field, leading to simple direct
computation and qualitative understanding. The results are given for generic as
well as supersymmetric gauge theories. These complement the set of well-known
gamma- and beta-functions of Machacek/Vaughn. As an application, we compute the
beta-functions for VEVs and tan(beta) in the MSSM, NMSSM and E6SSM.


title: Apochromatic Beam Transport in Drift-Quadrupole Systems

abstract:
  Though a straight drift-quadrupole system can not be made an achromat, there
exists an example of a bend-free drift-quadrupole system which can transport
certain incoming beam ellipses without introducing first-order chromatic
distortions. In this paper we show that such a possibility is not a rare
special case, but a general property. For every drift-quadrupole system there
exists an unique set of Twiss parameters, which will be transported through
that system without first order chromatic distortions. Moreover, we prove that
at the same time these Twiss parameters minimize the absolute values of the
system chromaticities and also bring the second order effect of the betatron
oscillations on the longitudinal dynamics to the minimal possible value.


title:
Experimental demonstration of the acoustic frequency conversions by
  temporal phononic crystals

abstract:
  We report on the experimental investigation of the transmission spectra for
acoustic waves through temporal phononic crystals (TPCs), which are designed
structures with periodically time-varying density and bulk modulus. In our
experiment, the TPCs are instanced as the media that swap between air and
carbon dioxide repetitively, in between the sound source and the detector. The
transmission spectra for monochromatic incident acoustic waves exhibit a series
of equidistant peaks, manifesting novel up- and down-conversion effects while
not employing material nonlinearity. These experimental results agree with the
theoretical calculations based on the plane wave expansion in time domain.


title:
Crystalline Particle Packings on Constant Mean Curvature (Delaunay)
  Surfaces

abstract:
  We investigate the structure of crystalline particle arrays on constant mean
curvature (CMC) surfaces of revolution. Such curved crystals have been realized
physically by creating charge-stabilized colloidal arrays on liquid capillary
bridges. CMC surfaces of revolution, classified by Charles Delaunay in 1841,
include the 2-sphere, the cylinder, the vanishing mean curvature catenoid (a
minimal surface) and the richer and less investigated unduloid and nodoid. We
determine numerically candidate ground state configurations for 1000 point-like
particles interacting with a pairwise-repulsive dipole-dipole interaction
potential. We mimic stretching of capillary bridges by determining the
equilibrium configurations of particles arrayed on a sequence of Delaunay
surfaces obtained by increasing or decreasing the height at constant volume
starting from a given initial surface, either a fat cylinder or a square
cylinder. In this case the stretching process takes one through a complicated
sequence of Delaunay surfaces each with different geometrical parameters
including the aspect ratio, mean curvature and maximal Gaussian curvature.
Unduloids, catenoids and nodoids all appear in this process. Defect motifs in
the ground state evolve from dislocations at the boundary to dislocations in
the interior to pleats and scars in the interior and then isolated 7-fold
disclinations in the interior as the capillary bridge narrows at the waist
(equator) and the maximal (negative) Gaussian curvature grows. We also check
theoretical predictions that the isolated disclinations are present in the
ground state when the surface contains a geodesic disc with integrated Gaussian
curvature exceeding -pi/3. Finally we explore minimal energy configurations on
sets of slices of a given Delaunay surface and obtain configurations and defect
motifs consistent with those seen in stretching.


title:
Error Emittance and Error Twiss Functions in the Problem of
  Reconstruction of Difference Orbit Parameters by Usage of BPMs with Finite
  Resolution

abstract:
  The problem of errors, arising due to finite BPM resolution, in the
difference orbit parameters, which are found as a least squares fit to the BPM
data, is one of the standard problems of the accelerator physics. In this
article we present a "dynamical point of view" on this problem, which allows us
to describe properties of the BPM measurement system in terms of the usual
accelerator physics concepts of emittance and betatron functions.


title: Persistent current induced by vacuum fluctuations in a quantum ring

abstract:
  We study theoretically interaction between electrons in a quantum ring
embedded in a microcavity and vacuum fluctuations of electromagnetic field in
the cavity. It is shown that the vacuum fluctuations can split electron states
of the ring with opposite angular momenta. As a consequence, the ground state
of electron system in the quantum ring can be associated to nonzero electric
current. Since a ground-state current flows without dissipation, such a quantum
ring gets a magnetic moment and can be treated as an artificial spin.


title: Enveloping semigroups of systems of order d

abstract:
  In this paper we study the Ellis semigroup of a d-step nilsystem and the
inverse limit of such systems. By using the machinery of cubes developed by
Host, Kra and Maass, we prove that such a system has a d-step topologically
nilpotent enveloping semigroup. In the case d=2, we prove that these notions
are equivalent, extending a previous result by Glasner.


title:
Tilted Sextupoles for Correction of Chromatic Aberrations in Beam Lines
  with Horizontal and Vertical Dispersions

abstract:
  In this article we discuss the usage of tilted multipoles for correction of
chromatic aberrations in the design of the beam switchyard arc at the European
X-Ray Free-Electron Laser (XFEL) Facility.


title: Prime Submodules And A Sheaf On The Prime Spectra Of Modules

abstract:
  We define and investigate a sheaf of modules on the prime spectra of modules
and it is shown that there is an isomorphism between the sections of this sheaf
and the ideal transform module.


title: Topological structure of non-separable sigma-locally compact convex sets

abstract:
  For an infinite cardinal $\kappa$ let $\ell_2(\kappa)$ be the linear hull of
the standard othonormal base of the Hilbert space $\ell_2(\kappa)$ of density
$\kappa$. We prove that a non-separable convex subset $X$ of density $\kappa$
in a locally convex linear metric space if homeomorphic to the space (i)
$\ell_2^f(\kappa)$ if and only if $X$ can be written as countable union of
finite-dimensional locally compact subspaces, (ii) $[0,1]^\omega\times
\ell_2^f(\kappa)$ if and only if $X$ contains a topological copy of the Hilbert
cube and $X$ can be written as a countable union of locally compact subspaces.


title: Large Energy Acceptance Dogleg for the XFEL Injector

abstract:
  The option to install two injectors is foreseen at the European XFEL
Facility. The injectors will be located on top of each other in the same
building, both with the offset of 2.75 m with respect to the main linac axis.
The translation system (dogleg) from the injector axis to the main linac axis
has to fulfill very tight requirements of the chromatic properties, because the
energy chirp required for the downstream bunch length compression in magnetic
chicanes will be created upstream in the injector linac. In this paper we
present such an large energy acceptance dogleg and discuss the optical
principles which form the basis of its design.


title: Are Financial Markets an aspect of Quantum World?

abstract:
  Writing the article-Time independent pricing of options in range bound
markets; the question in the title came naturally to my mind. It is stated, in
the above article, that in certain market conditions the stock price is
subjected to an equation that exactly matches a time independent Schrodinger
equation. The time independent equation for options valuation is used further
to explain a stock market phenomenon that resembles an alpha particle decay
tunneling effect. The transmission coefficient for the stock price tunneling
effect it is also deduced. Although, it may not have important impact in
quantum physics, the philosophical aspects residing in the use of quantum
mechanics for stock market specific are very important.


title: New Approaches for Improvement of TOF-PET

abstract:
  We present results of simulations on the influence of photon propagation and
the Cherenkov effect on the time resolution of LSO:Ce scintillators. The
influence of the scintillator length on the coincidence time resolution is
shown. Furthermore, the impact of the depth of interaction on the time
resolution, the light output and the arrival time distribution at the photon
detector is simulated and it is shown how these information can be used for
time walk correction.


title:
On minimal Lagrangian surfaces in the product of Riemannian two
  manifolds

abstract:
  Let $(\Sigma_1,g_1)$ and $(\Sigma_2,g_2)$ be connected, complete and
orientable Riemannian two manifolds. Consider the two canonical K\"ahler
structures $(G^{\epsilon},J,\Omega^{\epsilon})$ on the product 4-manifold
$\Sigma_1\times\Sigma_2$ given by $ G^{\epsilon}=g_1\oplus \epsilon g_2$,
$\epsilon=\pm 1$ and $J$ is the canonical product complex structure. Thus for
$\epsilon=1$ the K\"ahler metric $G^+$ is Riemannian while for $\epsilon=-1$,
$G^-$ is of neutral signature. We show that the metric $G^{\epsilon}$ is
locally conformally flat iff the Gauss curvatures $\kappa(g_1)$ and
$\kappa(g_2)$ are both constants satisfying $\kappa(g_1)=-\epsilon\kappa(g_2)$.
We also give conditions on the Gauss curvatures for which every
$G^{\epsilon}$-minimal Lagrangian surface is the product
$\gamma_1\times\gamma_2\subset\Sigma_1\times\Sigma_2$, where $\gamma_1$ and
$\gamma_2$ are geodesics of $(\Sigma_1,g_1)$ and $(\Sigma_2,g_2)$,
respectively. Finally, we explore the Hamiltonian stability of projected rank
one Hamiltonian $G^{\epsilon}$-minimal surfaces.


title:
Mid-rapidity anti-baryon to baryon ratios in pp collisions at $\sqrt{s}$
  = 0.9, 2.76 and 7 TeV measured by ALICE

abstract:
  The ratios of yields of anti-baryons to baryons probes the mechanisms of
baryon-number transport. Results for $\bar{\rm p}/{\rm p}$, $\bar{\rm
\Lambda}/{\rm \Lambda}$, $\rm\bar{\Xi}$$^{+}/{\rm \Xi}^{-}$ and
$\rm\bar{\Omega}$$^{+}/{\rm \Omega}^{-}$ in pp collisions at $\sqrt{s} = 0.9$,
2.76 and 7 TeV, measured with the ALICE detector at the LHC, are reported.
Within the experimental uncertainties and ranges covered by our measurement,
these ratios are independent of rapidity, transverse momentum and multiplicity
for all measured energies. The results are compared to expectations from event
generators, such as PYTHIA and HIJING-B, that are used to model the particle
production in pp collisions. The energy dependence of $\bar{\rm p}/{\rm p}$,
$\bar{\rm \Lambda}/{\rm \Lambda}$, $\rm\bar{\Xi}$$^{+}/{\rm \Xi^{-}}$ and
$\rm\bar{\Omega}$$^{+}/{\rm \Omega^{-}}$, reaching values compatible with unity
for $\sqrt{s} = 7$ TeV, complement the earlier $\bar{\rm p}/{\rm p}$
measurement of ALICE. These dependencies can be described by exchanges with the
Regge-trajectory intercept of $\alpha_{\rm {J}} \approx 0.5$, which are
suppressed with increasing rapidity interval ${\rm \Delta} y$. Any significant
contribution of an exchange not suppressed at large ${\rm \Delta} y$ (reached
at LHC energies) is disfavoured.


title: Overview of Electroweak Baryogenesis

abstract:
  Electroweak baryogenesis is briefly overviewed with emphasis on nondecoupling
loop properties of the scalar particles. In particular, quantum corrections to
the triple Higgs boson coupling is discussed as a probe of electroweak
baryogenesis.


title: Late-time tails in extremal Reissner-Nordstrom spacetime

abstract:
  This note discusses the late-time decay of perturbations outside extremal
Reissner-Nordstrom black hole. We consider individual spherical-harmonic modes
$l$ of massless scalar field. The initial data are assumed to be of compact
support, with generic regular behavior across the horizon. The scalar
perturbations are found to decay at late time as $t^{-(2l+2)}$. We also provide
the spatial dependence of the late-time tails, including the exact overall
pre-factor.


title: AdS-Wave Solutions of f(Riemann) Theories

abstract:
  We show that the recently found AdS-plane and AdS-spherical wave solutions of
quadratic curvature gravity also solve the most general higher derivative
theory in D-dimensions. More generally, we show that the field equations of
such theories reduce to an equation linear in the Ricci tensor for Kerr-Schild
spacetimes having type-N Weyl and traceless Ricci tensors.


title: Chern-Simons supergravities, with a twist

abstract:
  We discuss noncommutative extensions of Chern-Simons (CS) supergravities in
odd dimensions. The example of D=5 CS supergravity, invariant under the gauge
supergroup SU(2,2|N), is worked out in detail. Its noncommutative version is
found to exist only for N=4.


title:
Almost one bit violation for the additivity of the minimum output
  entropy

abstract:
  In a previous paper, we proved that the limit of the collection of possible
eigenvalues of output states of a random quantum channel is a deterministic,
compact set K_{k,t}. We also showed that the set K_{k,t} is obtained, up to an
intersection, as the unit ball of the dual of a free compression norm. In this
paper, we identify the maximum of l^p norms on the set K_{k,t} and prove that
the maximum is attained on a vector of shape (a,b,...,b) where a > b. In
particular, we compute the precise limit value of the minimum output entropy of
a single random quantum channel. As a corollary, we show that for any eps > 0,
it is possible to obtain a violation for the additivity of the minimum output
entropy for an output dimension as low as 183, and that for appropriate choice
of parameters, the violation can be as large as log 2 - eps. Conversely, our
result implies that, with probability one, one does not obtain a violation of
additivity using conjugate random quantum channels and the Bell state, in
dimension 182 and less.


title: 'Bose minus Einstein' and other examples of misattribution

abstract:
  Following the paper of J.D. Jackson [arXiv:0708.4249] on a false attribution
of discoveries, equations, and methods [Am. J. Phys. 76, 704-719 (2008)] I
consider examples, in which some of independent discoverers are forgotten, and
in other cases discoveries and effects are attributed to people who did not
discover them at all. I also discuss in brief why that happens and how physics
community can avoid this.


title: Integer and Fractional Quantum Hall Effect in a Strip of Stripes

abstract:
  We study anisotropic stripe models of interacting electrons in the presence
of magnetic fields in the quantum Hall regime with integer and fractional
filling factors. The model consists of an infinite strip of finite width that
contains periodically arranged stripes (forming supercells) to which the
electrons are confined and between which they can hop with associated magnetic
phases. The interacting electron system within the one-dimensional stripes are
described by Luttinger liquids and shown to give rise to charge and spin
density waves that lead to periodic structures within the stripe with a
reciprocal wavevector 8k_F. This wavevector gives rise to Umklapp scattering
and resonant scattering that results in gaps and chiral edge states at all
known integer and fractional filling factors \nu. The integer and odd
denominator filling factors arise for a uniform distribution of stripes,
whereas the even denominator filling factors arise for a non-uniform stripe
distribution. We calculate the Hall conductance via the Streda formula and show
that it is given by \sigma_H=\nu e^2/h for all filling factors. We show that
the composite fermion picture follows directly from the condition of the
resonant Umklapp scattering.


title: NMR-Based Diffusion Lattice Imaging

abstract:
  Nuclear magnetic resonance (NMR) diffusion experiments are widely employed as
they yield information about structures hindering the diffusion process, e.g.
about cell membranes. While it has been shown in recent articles, that these
experiments can be used to determine the exact shape of closed pores averaged
over a volume of interest, it is still an open question how much information
can be gained in open systems. In this theoretical work, we show that the full
structure information of periodic open systems is accessible. To this end, the
so-called 'SEquential Rephasing by Pulsed field-gradient Encoding N
Time-intervals' (SERPENT) sequence is used, which employs several diffusion
weighting gradient pulses with different amplitudes. The structural information
is obtained by an iterative technique relying on a Gaussian envelope model of
the diffusion propagator. Two solid matrices that are surrounded by an
NMR-visible medium are considered: a hexagonal lattice of cylinders and a cubic
lattice of triangles.


title: Synchronization properties of self-sustained mechanical oscillators

abstract:
  We study, both analytically and numerically, the dynamics of mechanical
oscillators kept in motion by a feedback force, which is generated
electronically from a signal produced by the oscillators themselves. This kind
of self-sustained systems may become standard in the design of
frequency-control devices at microscopic scales. Our analysis is thus focused
on their synchronization properties under the action of external forces, and on
the joint dynamics of two to many coupled oscillators. Existence and stability
of synchronized motion are assessed in terms of the mechanical properties of
individual oscillators --namely, their natural frequencies and damping
coefficients-- and synchronization frequencies are determined. Similarities and
differences with synchronization phenomena in other coupled oscillating systems
are emphasized.


title:
Lifting pseudo-holomorphic polygons to the symplectisation of $P \times
  \mathbb{R}$ and applications

abstract:
  Let $\mathbb{R} \times (P \times \mathbb{R})$ be the symplectisation of the
contactisation of an exact symplectic manifold $P$, and let $\mathbb{R} \times
\Lambda$ be a cylinder over a Legendrian submanifold in the contactisation. We
show that a pseudo-holomorphic polygon in $P$ having boundary on the projection
of $\Lambda$ can be lifted to a pseudo-holomorphic disc in the symplectisation
having boundary on $\mathbb{R} \times \Lambda$. It follows that Legendrian
contact homology may be equivalently defined by counting either of these
objects. Using this result, we give a proof of Seidel's isomorphism of the
linearised Legendrian contact homology induced by an exact Lagrangian filling
and the singular homology of the filling.


title:
Multi-Scale Codes in the Nervous System: The Problem of Noise
  Correlations and the Ambiguity of Periodic Scales

abstract:
  Encoding information about continuous variables using noisy computational
units is a challenge; nonetheless, asymptotic theory shows that combining
multiple periodic scales for coding can be highly precise despite the
corrupting influence of noise (Mathis et al., Phys. Rev. Lett. 2012). Indeed,
cortex seems to use such stochastic multi-scale periodic `grid codes' to
represent position accurately. We show here how these codes can be read out
without taking the asymptotic limit; even on short time scales, the precision
of neuronal grid codes scales exponentially in the number N of neurons. Does
this finding also hold for neurons that are not statistically independent? To
assess the extent to which biological grid codes are subject to statistical
dependencies, we analyze the noise correlations between pairs of grid code
neurons in behaving rodents. We find that if the grids of the two neurons align
and have the same length scale, the noise correlations between the neurons can
reach 0.8. For increasing mismatches between the grids of the two neurons, the
noise correlations fall rapidly. Incorporating such correlations into a
population coding model reveals that the correlations lessen the resolution,
but the exponential scaling of resolution with N is unaffected.


title:
Solar Flare X-ray Source Motion as a Response to Electron Spectral
  Hardening

abstract:
  Context: Solar flare hard X-rays (HXRs) are thought to be produced by
nonthermal coronal electrons stopping in the chromosphere, or remaining trapped
in the corona. The collisional thick target model (CTTM) predicts that sources
produced by harder power-law injection spectra should appear further down the
legs or footpoints of a flare loop. Therefore, hardening of the injected
power-law electron spectrum during flare onset should be concurrent with a
descending hard X-ray source.
  Aims: To test this implication of the CTTM by comparing its predicted HXR
source locations with those derived from observations of a solar flare which
exhibits a nonthermally-dominated spectrum before the peak in HXRs, known as an
early impulsive event.
  Methods: HXR images and spectra of an early impulsive C-class flare were
obtained using the Ramaty High-Energy Solar Spectroscopic Imager (RHESSI).
Images were reconstructed to produce HXR source height evolutions for three
energy bands. Spatially-integrated spectral analysis was performed to isolate
nonthermal emission, and to determine the power-law index of the electron
injection spectrum. The observed height-time evolutions were then fit with
CTTM-based simulated heights for each energy.
  Results: A good match between model and observed source heights was reached,
requiring a density model that agreed well with previous studies of flare loop
densities.
  Conclusions: The CTTM has been used to produce a descent of model HXR source
heights that compares well with observations of this event. Based on this
interpretation, downward motion of nonthermal sources should indeed occur in
any flare where there is spectral hardening in the electron distribution during
a flare. However, this would often be masked by thermal emission associated
with flare plasma pre-heating.


title:
Search for CP Violation in B0B0bar Mixing using Partial Reconstruction
  of B0-->D*-Xl+ nu and a Kaon Tag

abstract:
  We present results of a search for CP violation in B0B0bar mixing with the
BABAR detector. We select a sample of B0-->D*-Xl+ nu decays with a partial
reconstruction method and use kaon tagging to assess the flavor of the other B
meson in the event. We determine the CP violating asymmetry
  ACP = (N(B0B0) - N(B0bar B0bar))/(N(B0B0) + N(B0bar
B0bar))=(0.06+-0.17+0.38-0.32)%, corresponding to delta_CP =1 - |q/p|
=(0.29+-0.84+1.88 -1.61)*10^-3.


title:
Bounds on the density of sources of ultra-high energy cosmic rays from
  the Pierre Auger Observatory

abstract:
  We derive lower bounds on the density of sources of ultra-high energy cosmic
rays from the lack of significant clustering in the arrival directions of the
highest energy events detected at the Pierre Auger Observatory. The density of
uniformly distributed sources of equal intrinsic intensity was found to be
larger than $\sim (0.06 - 5) \times 10^{-4}$ Mpc$^{-3}$ at 95% CL, depending on
the magnitude of the magnetic deflections. Similar bounds, in the range $(0.2 -
7) \times 10^{-4}$ Mpc$^{-3}$, were obtained for sources following the local
matter distribution.


title: Non Abelian Fields in Very Special Relativity

abstract:
  We study non-Abelian fields in the context of very special relativity (VSR).
For this we define the covariant derivative and the gauge field gauge
transformations, both of them involving a fixed null vector $n_{\mu}$, related
to the VSR breaking of the Lorentz group to the Hom(2) or Sim(2) subgroups. As
in the Abelian case the gauge field becomes massive. Moreover we show that the
VSR gauge transformations form a closed algebra. We then write actions coupling
the gauge field to various matter fields (bosonic and fermionic). We mention
how we can use the spontaneous symmetry breaking mechanism to give a flavor
dependent VSR mass to the gauge bosons. Finally, we quantize the model using
the BRST formalism to fix the gauge. The model is renormalizable and unitary
and for non abelian groups, asymptotically free.


title:
Projective simulation for classical learning agents: a comprehensive
  investigation

abstract:
  We study the model of projective simulation (PS), a novel approach to
artificial intelligence based on stochastic processing of episodic memory which
was recently introduced [H.J. Briegel and G. De las Cuevas. Sci. Rep. 2, 400,
(2012)]. Here we provide a detailed analysis of the model and examine its
performance, including its achievable efficiency, its learning times and the
way both properties scale with the problems' dimension. In addition, we situate
the PS agent in different learning scenarios, and study its learning abilities.
A variety of new scenarios are being considered, thereby demonstrating the
model's flexibility. Furthermore, to put the PS scheme in context, we compare
its performance with those of Q-learning and learning classifier systems, two
popular models in the field of reinforcement learning. It is shown that PS is a
competitive artificial intelligence model of unique properties and strengths.


title: A model for the nonautonomous Hopf bifurcation

abstract:
  Inspired by an example of Grebogi et al [1], we study a class of model
systems which exhibit the full two-step scenario for the nonautonomous Hopf
bifurcation, as proposed by Arnold [2]. The specific structure of these models
allows a rigorous and thorough analysis of the bifurcation pattern. In
particular, we show the existence of an invariant 'generalised torus' splitting
off a previously stable central manifold after the second bifurcation point.
  The scenario is described in two different settings. First, we consider
deterministically forced models, which can be treated as continuous skew
product systems on a compact product space. Secondly, we treat randomly forced
systems, which lead to skew products over a measure-preserving base
transformation. In the random case, a semiuniform ergodic theorem for random
dynamical systems is required, to make up for the lack of compactness.


title:
q-deformations of two-dimensional Yang-Mills theory: Classification,
  categorification and refinement

abstract:
  We characterise the quantum group gauge symmetries underlying q-deformations
of two-dimensional Yang-Mills theory by studying their relationships with the
matrix models that appear in Chern-Simons theory and six-dimensional N=2 gauge
theories, together with their refinements and supersymmetric extensions. We
develop uniqueness results for quantum deformations and refinements of gauge
theories in two dimensions, and describe several potential analytic and
geometric realisations of them. We reconstruct standard q-deformed Yang-Mills
amplitudes via gluing rules in the representation category of the quantum group
associated to the gauge group, whose numerical invariants are the usual
characters in the Grothendieck group of the category. We apply this formalism
to compute refinements of q-deformed amplitudes in terms of generalised
characters, and relate them to refined Chern-Simons matrix models and
generalized unitary matrix integrals in the quantum beta-ensemble which compute
refined topological string amplitudes. We also describe applications of our
results to gauge theories in five and seven dimensions, and to the dual
superconformal field theories in four dimensions which descend from the N=(2,0)
six-dimensional superconformal theory.


title:
A Decade-Baseline Study of the Plasma States of Ejecta Knots in
  Cassiopeia A

abstract:
  We present the analysis of 21 bright X-ray knots in the Cassiopeia A
supernova remnant from observations spanning 10 yr. We performed a
comprehensive set of measurements to reveal the kinematic and thermal state of
the plasma in each knot, using a combined analysis of two high energy
resolution High Energy Transmission Grating (HETG) and four medium energy
resolution Advanced CCD Imaging Spectrometer (ACIS) sets of spectra. The ACIS
electron temperature estimates agree with the HETG-derived values for
approximately half of the knots studied, yielding one of the first comparisons
between high resolution temperature estimates and ACIS-derived temperatures. We
did not observe the expected spectral evolutionpredicted from the ionization
age and density estimates for each knotin all but three of the knots studied.
The incompatibility of these measurements with our assumptions has led us to
propose a dissociated ejecta model, with the metals unmixed inside the knots,
which could place strong constraints on supernova mixing models.


title:
The scattering map in two coupled piecewise-smooth systems, with
  numerical application to rocking blocks

abstract:
  We consider a non-autonomous dynamical system formed by coupling two
piecewise-smooth systems in $\RR^2$ through a non-autonomous periodic
perturbation. We study the dynamics around one of the heteroclinic orbits of
one of the piecewise-smooth systems. In the unperturbed case, the system
possesses two $C^0$ normally hyperbolic invariant manifolds of dimension two
with a couple of three dimensional heteroclinic manifolds between them. These
heteroclinic manifolds are foliated by heteroclinic connections between $C^0$
tori located at the same energy levels. By means of the {\em impact map} we
prove the persistence of these objects under perturbation. In addition, we
provide sufficient conditions of the existence of transversal heteroclinic
intersections through the existence of simple zeros of Melnikov-like functions.
The heteroclinic manifolds allow us to define the {\em scattering map}, which
links asymptotic dynamics in the invariant manifolds through heteroclinic
connections. First order properties of this map provide sufficient conditions
for the asymptotic dynamics to be located in different energy levels in the
perturbed invariant manifolds. Hence we have an essential tool for the
construction of a heteroclinic skeleton which, when followed, can lead to the
existence of Arnol'd diffusion: trajectories that, on large time scales,
destabilize the system by further accumulating energy. We validate all the
theoretical results with detailed numerical computations of a mechanical system
with impacts, formed by the linkage of two rocking blocks with a spring.


title:
Phase diagram for charged scalars in a magnetic field at finite
  temperature

abstract:
  We investigate the nature of the phase transition for charged scalars in the
presence of a magnetic background for a theory with spontaneous symmetry
breaking. We perform a careful treatment of the negative mass squared as a
function of the order parameter and present a suitable method to obtain
magnetic and thermal corrections up to ring order for the high temperature
limit and the case where the magnetic field strength is larger than the
absolute value of the square of the mass parameter. We show that for a given
value of the self-coupling, the phase transition is first order for a small
magnetic field strength and becomes second order as this last grows. We also
show that the critical temperature in the presence of the magnetic field is
always below the critical temperature for the case where the field is absent.


title:
Constraining the Galactic millisecond pulsar population using Fermi
  Large Area Telescope

abstract:
  The Fermi Large Area Telescope (Fermi-LAT) has recently revealed a large
population of gamma-ray emitting millisecond pulsars (MSPs) in our Galaxy. We
aim to infer the properties of the Galactic population of gamma-ray emitting
MSPs from the samples detected by the Fermi-LAT. We developed a Monte Carlo
model to predict the spatial and gamma-ray luminosity distribution of the
Galactic MSP population. Based on the estimated detection sensitivity of
Fermi-LAT, we split the model population into detectable and undetectable
samples of MSPs. Using a maximum likelihood method, we compared the detectable
sample to a set of 36 MSPs detected by Fermi-LAT, and we derived the parameters
of the spatial distribution and the total number of gamma-ray emitting MSPs in
the Galaxy. The corresponding undetectable sample provided us with an estimate
for the expected diffuse emission from unresolved MSPs in the Milky Way. We
also applied our method to an extended sample of 66 MSPs that combines firmly
detected MSPs and gamma-ray sources that show characteristics reminiscent of
MSPs. For the first time our analysis provides gamma-ray based constraints on
the Galactic population of MSPs. The radial scale length and vertical scale
height of the population is consistent with estimates based on radio data. Our
analysis suggests that MSPs do not provide any significant contribution to the
isotropic diffuse gamma-ray background emission.


title:
Beam Studies of the Segmented Resistive WELL: a Potential Thin Sampling
  Element for Digital Hadron Calorimetry

abstract:
  Thick Gas Electron Multipliers (THGEMs) have the potential of constituting
thin, robust sampling elements in Digital Hadron Calorimetry (DHCAL) in future
colliders. We report on recent beam studies of new single- and
double-THGEM-like structures; the multiplier is a Segmented Resistive WELL
(SRWELL) - a single-faced THGEM in contact with a segmented resistive layer
inductively coupled to readout pads. Several 10$\times$10 cm$^2$ configurations
with a total thickness of 5-6 mm (excluding electronics) with 1 cm$^2$ pads
coupled to APV-SRS readout were investigated with muons and pions. Detection
efficiencies in the 98$%$ range were recorded with average pad-multiplicity of
$\sim$1.1. The resistive anode resulted in efficient discharge damping, with
potential drops of a few volts; discharge probabilities were $\sim10^{-7}$ for
muons and $\sim10^{-6}$ for pions in the double-stage configuration, at rates
of a few kHz/cm$^2$. Further optimization work and research on larger detectors
are underway.


title:
The relation of the parameters of the critical point of liquid-gas
  transition with the Boyle temperature

abstract:
  It is shown that the ratio of the Boyle temperature to the product of
critical temperature and critical compressibility factor is equal to the number
9 with high accuracy for 21 real substances as predicted from Van-der-Waals
equation of state. The relation is suggested to find the critical volume via
the ratio of the Boyle temperature to the critical pressure. The formula is
suggested also to define the critical volume via the critical temperature and
the parameters of the linear line of unite compressibility.


title:
BoltzWann: A code for the evaluation of thermoelectric and electronic
  transport properties with a maximally-localized Wannier functions basis

abstract:
  We present a new code to evaluate thermoelectric and electronic transport
properties of extended systems with a maximally-localized Wannier function
basis set. The semiclassical Boltzmann transport equations for the homogeneous
infinite system are solved in the constant relaxation-time approximation and
band energies and band derivatives are obtained via Wannier interpolations.
Thanks to the exponential localization of the Wannier functions obtained, very
high accuracy in the Brillouin zone integrals can be achieved with very
moderate computational costs. Moreover, the analytical expression for the band
derivatives in the Wannier basis resolves any issues that may occur when
evaluating derivatives near band crossings. The code is tested on binary and
ternary skutterudites CoSb_3 and CoGe_{3/2}S_{3/2}.


title:
Mono-atomic disintegration and Lyapunov exponents for derived from
  Anosov diffeomorphisms

abstract:
  In this paper we mainly address the problem of disintegration of Lebesgue
measure and measure of maximal entropy along the central foliation of
(conservative) Derived from Anosov (DA) diffeomorphisms. We prove that for
accessible DA diffeomorphisms of $\mathbb{T}^3$, atomic disintegration has the
peculiarity of being mono-atomic (one atom per leaf). We further provide open
and non-empty condition for the existence of atomic disintegration. Finally, we
prove some new relations between Lyapunov exponents of DA diffeomorphisms and
their linearization.


title:
Coherent tunnelling across a quantum point contact in the quantum Hall
  regime

abstract:
  The unique properties of quantum Hall devices arise from the ideal
one-dimensional edge states that form in a two-dimensional electron system at
high magnetic field. Tunnelling between edge states across a quantum point
contact (QPC) has already revealed rich physics, like fractionally charged
excitations, or chiral Luttinger liquid. Thanks to scanning gate microscopy, we
show that a single QPC can turn into an interferometer for specific potential
landscapes. Spectroscopy, magnetic field and temperature dependences of
electron transport reveal a quantitatively consistent interferometric behavior
of the studied QPC. To explain this unexpected behavior, we put forward a new
model which relies on the presence of a quantum Hall island at the centre of
the constriction as well as on different tunnelling paths surrounding the
island, thereby creating a new type of interferometer. This work sets the
ground for new device concepts based on coherent tunnelling.


title: Surface-area-minimizing n-hedral Tiles

abstract:
  We provide a list of conjectured surface-area-minimizing n-hedral tiles of
space for n from 4 to 14, previously known only for n equal to 5 or 6. We find
the optimal "orientation-preserving" tetrahedral tile (n=4), and we give a nice
proof for the optimal 5-hedron (a triangular prism).


title: On Algebraic Functions

abstract:
  In this note we consider functions with Moebius-periodic rational
coefficients. These functions under some conditions take algebraic values and
can be recovered by theta functions and the Dedekind eta function. Special
cases are the elliptic singular moduli, the Rogers-Ramanujan continued
fraction, Eisenstein series and functions associated with Jacobi symbol
coefficients.


title:
Logarithmic Quasi-distance Proximal Point Scalarization Method for
  Multi-Objective Programming

abstract:
  Recently, Greg\'orio and Oliveira developed a proximal point scalarization
method (applied to multi-objective optimization problems) for an abstract
strict scalar representation with a variant of the logarithmic-quadratic
function of Auslender et al. as regularization. In this study, a variation of
this method is proposed, using the regularization with logarithm and
quasi-distance, which entails losing important properties, such as convexity
and differentiability. However, proceeding differently, it is shown that any
sequence \{(x^k, z^k)\} \includ R^n \times R^{m}_{++} generated by the method
satisfies: \{z^k\} is convergent and \{x^k\} is bounded and its accumulation
points are weak pareto solutions of the unconstrained multi-objective
optimization problem


title: Mean field variational framework for integer optimization

abstract:
  A principled method to obtain approximate solutions of general constrained
integer optimization problems is introduced. The approach is based on the
calculation of a mean field probability distribution for the decision variables
which is consistent with the objective function and the constraints. The
original discrete task is in this way transformed into a continuous variational
problem. In the context of particular problem classes at small and medium
sizes, the mean field results are comparable to those of standard specialized
methods, while at large sized instances is capable to find feasible solutions
in computation times for which standard approaches can't find any valuable
result. The mean field variational framework remains valid for widely diverse
problem structures so it represents a promising paradigm for large dimensional
nonlinear combinatorial optimization tasks.


title: Lattices in the cohomology of Shimura curves

abstract:
  We prove conjectures of Breuil and Breuil-Dembele (C. Breuil, "Sur un
probleme de compatibilite local-global modulo p pour GL(2)"), including a
generalisation from the principal series to the cuspidal case, subject to a
mild global hypothesis that we make in order to apply certain R=T theorems.
More precisely, we prove a multiplicity one result for the mod p cohomology of
a Shimura curve at Iwahori level, and we show that certain apparently globally
defined lattices in the cohomology of Shimura curves are determined by the
corresponding local p-adic Galois representations. We also indicate a new proof
of the Buzzard-Diamond-Jarvis conjecture in generic cases. Our main tools are
the geometric Breuil-Mezard philosophy developed by two of the authors, and a
new and more functorial perspective on the Taylor-Wiles-Kisin patching method.
Along the way, we determine the tamely potentially Barsotti-Tate deformation
rings of generic two-dimensional mod p representations, generalising a result
of Breuil-Mezard in the principal series case.


title:
Galaxy pairs in the Sloan Digital Sky Survey - VI. The orbital extent of
  enhanced star formation in interacting galaxies

abstract:
  We use pair and environmental classifications of ~ 211,000 star-forming
galaxies from the Sloan Digital Sky Survey, along with a suite of merger
simulations, to investigate the enhancement of star formation as a function of
separation in galaxy pairs. Using a new technique for distinguishing between
the influence of nearby neighbours and larger scale environment, we find a
clear enhancement in star formation out to projected separations of ~ 150 kpc,
beyond which there is no net enhancement. We find the strongest enhancements at
the smallest separations (especially < 20 kpc), consistent with earlier work.
Similar trends are seen in the simulations, which indicate that the strongest
enhancements are produced in highly disturbed systems approaching final
coalescence, whereas the more modest enhancements seen at wider separations are
the result of starburst activity triggered at first pericentre passage, which
persists as the galaxies move to larger separations. The absence of any net
enhancement beyond 150 kpc provides reassurance that the detected enhancements
are due to galaxy-galaxy interactions, rather than larger scale environmental
effects or potential pair selection biases. A rough census indicates that 66
per cent of the enhanced star formation in our pair sample occurs at
separations > 30 kpc. We conclude that significant interaction-induced star
formation is not restricted to merger remnants or galaxies with close
companions; instead, a larger population of wider separation pairs exhibit
enhanced star formation due to recent close encounters.


title:
A Clifford Algebra approach to the Discretizable Molecular Distance
  Geometry Problem

abstract:
  The Discretizable Molecular Distance Geometry Problem (DMDGP) consists in a
subclass of the Molecular Distance Geometry Problem for which an embedding in
${\mathbb{R}^3}$ can be found using a Branch & Prune (BP) algorithm in a
discrete search space. We propose a Clifford Algebra model of the DMDGP with an
accompanying version of the BP algorithm.


title: Exceptional surgeries on knots with exceptional classes

abstract:
  We survey aspects of classical combinatorial sutured manifold theory and show
how they can be adapted to study exceptional Dehn fillings and 2-handle
additions. As a consequence we show that if a hyperbolic knot $\beta$ in a
compact, orientable, hyperbolic 3-manifold $M$ has the property that winding
number and wrapping number are not equal with respect to a non-trivial class in
$H_2(M,\boundary M)$, then, with only a few possible exceptions, every
3-manifold $M'$ obtained by Dehn surgery on $\beta$ with surgery distance
$\Delta \geq 2$ will be hyperbolic.


title: Abelian Group Codes for Source Coding and Channel Coding

abstract:
  In this paper, we study the asymptotic performance of Abelian group codes for
the lossy source coding problem for arbitrary discrete (finite alphabet)
memoryless sources as well as the channel coding problem for arbitrary discrete
(finite alphabet) memoryless channels. For the source coding problem, we derive
an achievable rate-distortion function that is characterized in a single-letter
information-theoretic form using the ensemble of Abelian group codes. When the
underlying group is a field, it simplifies to the symmetric rate-distortion
function. Similarly, for the channel coding problem, we find an achievable rate
characterized in a single-letter information-theoretic form using group codes.
This simplifies to the symmetric capacity of the channel when the underlying
group is a field. We compute the rate-distortion function and the achievable
rate for several examples of sources and channels. Due to the non-symmetric
nature of the sources and channels considered, our analysis uses a synergy of
information theoretic and group-theoretic tools.


title: Realistic Filter Cavities for Advanced Gravitational Wave Detectors

abstract:
  The ongoing global effort to detect gravitational waves continues to push the
limits of precision measurement while aiming to provide a new tool for
understanding both astrophysics and fundamental physics. Squeezed states of
light offer a proven means of increasing the sensitivity of gravitational wave
detectors, potentially increasing the rate at which astrophysical sources are
detected by more than an order of magnitude. Since radiation pressure noise
plays an important role in advanced detectors, frequency dependent squeezing
will be required. In this paper we propose a practical approach to producing
frequency dependent squeezing for Advanced LIGO and similar interferometric
gravitational wave detectors.

categories: physics.optics astro-ph.IM gr-qc quant-ph


title: Periodically Driven Holographic Superconductor

abstract:
  As a first step towards our holographic investigation of the
far-from-equilibrium physics of periodically driven systems at strong coupling,
we explore the real time dynamics of holographic superconductor driven by a
monochromatically alternating electric field with various frequencies. As a
result, our holographic superconductor is driven to the final oscillating
state, where the condensate is suppressed and the oscillation frequency is
controlled by twice of the driving frequency. In particular, in the large
frequency limit, the three distinct channels towards the final steady state are
found, namely under damped to superconducting phase, over damped to
superconducting and normal phase, which can be captured essentially by the low
lying spectrum of quasi-normal modes in the time averaged approximation,
reminiscent of the effective field theory perspective.


title: Gamma-rays Constraint on Higgs Production from Dark Matter Annihilation

abstract:
  A gamma line signal in cosmic-ray observation would be found when Higgs is
produced at rest or almost rest by DM annihilation because of decay of 126 GeV
Higgs into two gamma. This line signal gives a constraint on Higgs production
cross section by DM. We examine this point with simple analysis in this work.


title:
Ultracold Quantum Gases and Lattice Systems: Quantum Simulation of
  Lattice Gauge Theories

abstract:
  Abelian and non-Abelian gauge theories are of central importance in many
areas of physics. In condensed matter physics, Abelian U(1) lattice gauge
theories arise in the description of certain quantum spin liquids. In quantum
information theory, Kitaev's toric code is a Z(2) lattice gauge theory. In
particle physics, Quantum Chromodynamics (QCD), the non-Abelian SU(3) gauge
theory of the strong interactions between quarks and gluons, is
non-perturbatively regularized on a lattice. Quantum link models extend the
concept of lattice gauge theories beyond the Wilson formulation, and are well
suited for both digital and analog quantum simulation using ultracold atomic
gases in optical lattices. Since quantum simulators do not suffer from the
notorious sign problem, they open the door to studies of the real-time
evolution of strongly coupled quantum systems, which are impossible with
classical simulation methods. A plethora of interesting lattice gauge theories
suggests itself for quantum simulation, which should allow us to address very
challenging problems, ranging from confinement and deconfinement, or chiral
symmetry breaking and its restoration at finite baryon density, to color
superconductivity and the real-time evolution of heavy-ion collisions, first in
simpler model gauge theories and ultimately in QCD.

categories: quant-ph cond-mat.quant-gas cond-mat.str-el hep-lat