title:
Gamma-ray burst optical light-curve zoo: comparison with X-ray
  observations

abstract:
  We present a comprehensive analysis of the optical and X-ray light curves
(LCs) and spectral energy distributions (SEDs) of a large sample of gamma-ray
burst (GRB) afterglows to investigate the relationship between the optical and
X-ray emission after the prompt phase. We collected the optical data from the
literature and determined the shapes of the optical LCs. Then, using previously
presented X-ray data we modeled the optical/X-ray SEDs. We studied the SED
parameter distributions and compared the optical and X-ray LC slopes and
shapes. The optical and X-ray spectra become softer as a function of time while
the gas-to-dust ratios of GRBs are higher than the values calculated for the
Milky Way and the Large and Magellanic Clouds. For 20% of the GRBs the
difference between the optical and X-ray slopes is consistent with 0 or 1=4
within the uncertainties (we did it not consider the steep decay phase), while
in the remaining 80% the optical and X-ray afterglows show significantly
different temporal behaviors. Interestingly, we find an indication that the
onset of the forward shock in the optical LCs (initial peaks or shallow phases)
could be linked to the presence of the X-ray flares. Indeed, when X-ray flares
are present during the steep decay, the optical LC initial peak or end plateau
occurs during the steep decay; if instead the X-ray flares are absent or occur
during the plateau, the optical initial peak or end plateau takes place during
the X-ray plateau. The forward-shock model cannot explain all features of the
optical (e.g. bumps, late re-brightenings) and X-ray (e.g. flares, plateaus)
LCs. However, the synchrotron model is a viable mechanism for GRBs at late
times. In particular, we found a relationship between the presence of the X-ray
flares and the shape of the optical LC that indicates a link between the prompt
emission and the optical afterglow.


title: Causal transference plans and their Monge-Kantorovich problems

abstract:
  This paper investigates causal optimal transportation problems, in the
framework of two Polish spaces, both endowed with filtrations. Specific
concretizations yield primal problems equivalent to several classical problems
of stochastic control, and of stochastic calculus ; trivial filtrations yield
usual problems of optimal transport. Within this framework, primal attainments
and dual formulations are obtained, under standard hypothesis, for the related
variational problems. These problems are intrinsically related to martingales.
Finally, we investigate applications to stochastic frameworks. A
straightforward equivalence between specific causal optimization problems, and
problems of stochastic control, is obtained. Solutions to a class of stochastic
differential equations are characterized, as optimum to specific causal
Monge-Kantorovich problems ; the existence of a unique strong solution is
related to corresponding Monge problems.


title: A Comparative Analysis on the Applicability of Entropy in remote sensing

abstract:
  Entropy is the measure of uncertainty in any data and is adopted for
maximisation of mutual information in many remote sensing operations. The
availability of wide entropy variations motivated us for an investigation over
the suitability preference of these versions to specific operations.
Methodologies were implemented in Matlab and were enhanced with entropy
variations. Evaluation of various implementations was based on different
statistical parameters with reference to the study area The popular available
versions like Tsalli's, Shanon's, and Renyi's entropies were analysed in
context of various remote sensing operations namely thresholding, clustering
and registration.


title:
An investigation towards wavelet based optimization of automatic image
  registration techniques

abstract:
  Image registration is the process of transforming different sets of data into
one coordinate system and is required for various remote sensing applications
like change detection, image fusion, and other related areas. The effect of
increased relief displacement, requirement of more control points, and
increased data volume are the challenges associated with the registration of
high resolution image data. The objective of this research work is to study the
most efficient techniques and to investigate the extent of improvement
achievable by enhancing them with Wavelet transform. The SIFT feature based
method uses the Eigen value for extracting thousands of key points based on
scale invariant features and these feature points when further enhanced by the
wavelet transform yields the best results.


title: Updated S3 Model of Quarks

abstract:
  A model proposed in 2004 using the non-Abelian discrete symmetry S3 for
understanding the flavor structure of quarks and leptons is updated, with
special focus on the quark and scalar sectors. We show how the approximate
residual symmetries of this model explain both the pattern of the quark mixing
matrix and why the recently observed particle of 126 GeV at the Large Hadron
Collider is so much like the one Higgs boson of the Standard Model. We identify
the strongest phenomenological bounds on the scalar masses of this model, and
predict a possibly observable decay b -> s tau- mu+, but not b -> s tau+ mu-.


title: Dynamical holographic QCD model for glueball and light meson spectra

abstract:
  In this work, we offer a dynamical soft-wall model to describe the
gluodynamics and chiral dynamics in one systematical framework. We firstly
construct a quenched dynamical holographic QCD (hQCD) model in the
graviton-dilaton framework for the pure gluon system, then develop a dynamical
hQCD model for the two flavor system in the graviton-dilaton-scalar framework
by adding light flavors on the gluodynamical background. For two forms of
dilaton background field $\Phi=\mu_G^2z^2$ and
$\Phi=\mu_G^2z^2\tanh(\mu_{G^2}^4z^2/\mu_G^2)$, the quadratic correction to
dilaton background field at infrared encodes important non-perturbative
gluodynamics and naturally induces a deformed warp factor of the metric. By
self-consistently solving the deformed metric induced by the dilaton background
field, we find that the scalar glueball spectra in the quenched dynamical model
is in very well agreement with lattice data. For two flavor system in the
graviton-dilaton-scalar framework, the deformed metric is self-consistently
solved by considering both the chiral condensate and nonperturbative
gluodynamics in the vacuum, which are responsible for the chiral symmetry
breaking and linear confinement, respectively. It is found that the mixing
between the chiral condensate and gluon condensate is important to produce the
correct light flavor meson spectra. The pion form factor and the vector
couplings are also investigated in the dynamical hQCD model. Besides, we give
the criteria for the existence of linear quark potential from the metric
structure, and show a negative quadratic dilaton background field is not
favored in the graviton-dilaton framework.


title: Intrinsic circle domains

abstract:
  Using quasiconformal mappings, we prove that any Riemann surface of finite
connectivity and finite genus is conformally equivalent to an intrinsic circle
domain U in a compact Riemann surface S. This means that each connected
component B of S \ U is either a point or a closed geometric disc with respect
to the complete constant curvature conformal metric of the Riemann surface (U
union B). Moreover the pair (U,S) is unique up to conformal isomorphisms. We
give a generalization to countably infinite connectivity. Finally we show how
one can compute numerical approximations to intrinsic circle domains using
circle packings and conformal welding.


title:
Degenerate states in the scalar boson spectrum. Is the Higgs Boson a
  Twin ?

abstract:
  The extension of the standard model to $SU(3)_L\times SU(3)_R \times SU(3)_C$
is considered. Spontaneous symmetry breaking requires two $(3^*, 3, 1)$ Higgs
field multiplets with a strong hierarchical structure of their vacuum
expectation values. An invariant potential is constructed to provide for these
vacuum expectation values. This potential gives masses to all scalar fields
apart from the 15 Goldstone bosons. In case there exists a one-to-one
correspondence between the vacuum expectation values of the two field
multiplets, the scalar boson spectrum contains degenerate eigenstates. The
lowest eigenstate has a mass near 123 GeV close to the Higgs-like particle
discovered at the LHC. In one class of solutions this lowest state is a nearly
degenerate twin state. Each member is a superposition of fields from both
multiplets with about equal strength. The twins are non identical twins, namely
different combinations of a conventional Higgs and a Higgs field which is not
coupled to fermions, only to gauge bosons. A second class of solutions leads
again to degenerate states but in this case the state near 123 GeV remains a
single state even for identical low scale vacuum expectation values in both
multiplets.


title: Bipolar Fuzzy Soft sets and its applications in decision making problem

abstract:
  In this article, we combine the concept of a bipolar fuzzy set and a soft
set. We introduce the notion of bipolar fuzzy soft set and study fundamental
properties. We study basic operations on bipolar fuzzy soft set. We define
exdended union, intersection of two bipolar fuzzy soft set. We also give an
application of bipolar fuzzy soft set into decision making problem. We give a
general algorithm to solve decision making problems by using bipolar fuzzy soft
set.


title: Hans Grauert (1930-2011)

abstract:
  Hans Grauert died in September of 2011. This article reviews his life in
mathematics and recalls some detail his major accomplishments.


title:
The fractional Laplacian operator on bounded domains as a special case
  of the nonlocal diffusion operator

abstract:
  We analyze a nonlocal diffusion operator having as special cases the
fractional Laplacian and fractional differential operators that arise in
several applications. In our analysis, a nonlocal vector calculus is exploited
to define a weak formulation of the nonlocal problem. We demonstrate that, when
sufficient conditions on certain kernel functions hold, the solution of the
nonlocal equation converges to the solution of the fractional Laplacian
equation on bounded domains as the nonlocal interactions become infinite. We
also introduce a continuous Galerkin finite element discretization of the
nonlocal weak formulation and we derive a priori error estimates. Through
several numerical examples we illustrate the theoretical results and we show
that by solving the nonlocal problem it is possible to obtain accurate
approximations of the solutions of fractional differential equations
circumventing the problem of treating infinite-volume constraints.


title:
Efficiently Using Second Order Information in Large l1 Regularization
  Problems

abstract:
  We propose a novel general algorithm LHAC that efficiently uses second-order
information to train a class of large-scale l1-regularized problems. Our method
executes cheap iterations while achieving fast local convergence rate by
exploiting the special structure of a low-rank matrix, constructed via
quasi-Newton approximation of the Hessian of the smooth loss function. A greedy
active-set strategy, based on the largest violations in the dual constraints,
is employed to maintain a working set that iteratively estimates the complement
of the optimal active set. This allows for smaller size of subproblems and
eventually identifies the optimal active set. Empirical comparisons confirm
that LHAC is highly competitive with several recently proposed state-of-the-art
specialized solvers for sparse logistic regression and sparse inverse
covariance matrix selection.


title:
First-Principles Calculation of Thermal Transport in the Metal/Graphene
  System

abstract:
  Thermal properties in the metal/graphene (Gr) systems are analyzed by using
an atomistic phonon transport model based on Landauer formalism and
first-principles calculations. The specific structures under investigation
include chemisorbed Ni(111)/Gr, physisorbed Cu(111)/Gr and Au(111)/Gr, as well
as Pd(111)/Gr with intermediate characteristics. Calculated results illustrate
a strong dependence of thermal transfer on the details of interfacial
microstructures. In particular, it is shown that the chemisorbed case provides
a generally smaller interfacial thermal resistance than the physisorbed due to
the stronger bonding. However, our calculation also indicates that the weakly
chemisorbed interface of Pd/Gr may be an exception, with the largest thermal
resistance among the considered. Further examination of the electrostatic
potential and interatomic force constants reveal that the mixed bonding force
between the Pd and C atoms results in incomplete hybridization of Pd and
graphene orbital states at the junction, leading effectively to two phonon
interfaces and a larger than expected thermal resistance. Comparison with
available experimental data shows good agreement. The result clearly suggests
the feasibility of phonon engineering for thermal property optimization at the
interface.


title: Cohomology jump loci of compact K\"ahler manifolds

abstract:
  We apply the method of Dimca-Papadima to study the cohomology jump loci in
the representation variety and the moduli space of vector bundles with
vanishing chern classes for a compact K\"ahler manifold. We introduce modules
over differential graded Lie algebra to extend results of Dimca-Papadima to a
general point in the representation variety or the moduli space. We show that
locally the cohomology jump loci is isomorphic to the resonance variety via the
exponential map. This paper generalizes a previous result of the author.


title:
Expectation Propagation for Neural Networks with Sparsity-promoting
  Priors

abstract:
  We propose a novel approach for nonlinear regression using a two-layer neural
network (NN) model structure with sparsity-favoring hierarchical priors on the
network weights. We present an expectation propagation (EP) approach for
approximate integration over the posterior distribution of the weights, the
hierarchical scale parameters of the priors, and the residual scale. Using a
factorized posterior approximation we derive a computationally efficient
algorithm, whose complexity scales similarly to an ensemble of independent
sparse linear models. The approach enables flexible definition of weight priors
with different sparseness properties such as independent Laplace priors with a
common scale parameter or Gaussian automatic relevance determination (ARD)
priors with different relevance parameters for all inputs. The approach can be
extended beyond standard activation functions and NN model structures to form
flexible nonlinear predictors from multiple sparse linear models. The effects
of the hierarchical priors and the predictive performance of the algorithm are
assessed using both simulated and real-world data. Comparisons are made to two
alternative models with ARD priors: a Gaussian process with a NN covariance
function and marginal maximum a posteriori estimates of the relevance
parameters, and a NN with Markov chain Monte Carlo integration over all the
unknown model parameters.


title: The 1/2 BPS Wilson loop in ABJM theory at two loops

abstract:
  We compute the expectation value of the 1/2 BPS circular Wilson loop in ABJM
theory at two loops in perturbation theory. The result shows perfect agreement
with the prediction from localization and the proposed framing factor.


title:
Higher Derivative Gravity and Conformal Gravity From Bimetric and
  Partially Massless Bimetric Theory

abstract:
  In this paper we establish the correspondence between ghost-free bimetric
theory and a class of higher derivative gravity actions, including conformal
gravity and New Massive Gravity. We also characterize the relation between the
respective equations of motion and classical solutions. We illustrate that, in
this framework, the spin-2 ghost of higher derivative gravity is an artifact of
the truncation to a 4-derivative theory. The analysis also gives a relation
between the proposed partially massless (PM) bimetric theory and conformal
gravity, showing, in particular, the equivalence of their equations of motion
at the 4-derivative level. For the PM bimetric theory this provides further
evidence for the existence of an extra gauge symmetry and the associated loss
of a propagating mode away from de Sitter backgrounds. The new symmetry is an
extension of Weyl symmetry which also suggests the PM bimetric theory as a
ghost-free completion of conformal gravity.


title:
Enhancement of gaps in thin graphitic films for heterostructure
  formation

abstract:
  There are a large number of atomically thin graphitic films with similar
structure to graphene. These films have a spread of bandgaps relating to their
ionicity, and also to the substrate on which they are grown. Such films could
have a range of applications in digital electronics where graphene is difficult
to use. I use the dynamical cluster approximation to show how electron-phonon
coupling between film and substrate can enhance these gaps in a way that
depends on the range and strength of the coupling. One of the driving factors
in this effect is the proximity to a charge density wave instability for
electrons on a honeycomb lattice. The enhancement at intermediate coupling is
sufficiently large that spatially varying substrates and superstrates could be
used to create heterostructures in thin graphitic films with position dependent
electron-phonon coupling and gaps, leading to advanced electronic components.


title:
Massive Dirac fermions and Hofstadter butterfly in a van der Waals
  heterostructure

abstract:
  Van der Waals heterostructures comprise a new class of artificial materials
formed by stacking atomically-thin planar crystals. Here, we demonstrate band
structure engineering of a van der Waals heterostructure composed of a
monolayer graphene flake coupled to a rotationally-aligned hexagonal boron
nitride substrate. The spatially-varying interlayer atomic registry results
both in a local breaking of the carbon sublattice symmetry and a long-range
moir\'e superlattice potential in the graphene. This interplay between short-
and long-wavelength effects results in a band structure described by isolated
superlattice minibands and an unexpectedly large band gap at charge neutrality,
both of which can be tuned by varying the interlayer alignment.
Magnetocapacitance measurements reveal previously unobserved fractional quantum
Hall states reflecting the massive Dirac dispersion that results from broken
sublattice symmetry. At ultra-high fields, integer conductance plateaus are
observed at non-integer filling factors due to the emergence of the Hofstadter
butterfly in a symmetry-broken Landau level.


title:
Wave front propagation for a reaction-diffusion equation in narrow
  random channels

abstract:
  We consider a reaction-diffusion equation in narrow random channels. We
approximate the generalized solution to this equation by the corresponding one
on a random graph. By making use of large deviation analysis we study the
asymptotic wave front propagation.


title: Sharp extensions for convoluted solutions of abstract Cauchy problems

abstract:
  In this paper we give sharp extension results for convoluted solutions of
abstract Cauchy problems in Banach spaces. The main technique is the use of
algebraic structure (for usual convolution product $\ast$) of these solutions
which are defined by a version of the Duhamel formula. We define algebra
homomorphisms from a new class of test-functions and apply our results to
concrete operators. Finally, we introduce the notion of $k$-distribution
semigroups to extend previous concepts of distribution semigroups.


title: Phantom energy accretion onto a black hole in Horava Lifshitz gravity

abstract:
  In this Letter, we examine the phantom energy accretion onto a
Kehagias-Sfetsos black hole in Ho$\check{r}$ava Lifshitz gravity. To discuss
the accretion process onto the black hole, the equations of phantom flow near
the black hole have been derived. It is found that mass of the black hole
decreases because of phantom accretion. We discuss the conditions for critical
accretion. Graphically, it has been found that the critical accretion phenomena
is possible for different values of parameters. The results for the
Schwarzschild black hole can be recovered in the limiting case.


title:
Asymptotic properties of boundary-value problem with transmission
  conditions

abstract:
  In this study by applying an own technique we investigate some asymptotic
approximation properties of new type discontinuous boundary-value problems,
which consists of a Sturm-Liouville equation together with
eigenparameter-dependent boundary and transmission conditions.


title: Boundary value problem with transmission conditions

abstract:
  One important innovation here is that for the Sturm-Liouville considered
equation together with eigenparameter dependent boundary conditions and two
supplementary transmission conditions at one interior point. We develop Green's
function method for spectral analysis of the considered problem in modified
Hilbert space.


title:
Asymptotic formulas for eigenvalues and eigenfunctions of boundary value
  problem

abstract:
  In this paper we are concerned with a new class of BVP' s consisting of
eigendependent boundary conditions and two supplementary transmission
conditions at one interior point. By modifying some techniques of classical
Sturm-Liouville theory and suggesting own approaches we find asymptotic
formulas for the eigenvalues and eigenfunction.


title: The Pesky Power Asymmetry

abstract:
  Physical models for the hemispherical power asymmetry in the cosmic microwave
background (CMB) reported by the Planck Collaboration must satisfy CMB
constraints to the homogeneity of the Universe and quasar constraints to power
asymmetries. We survey a variety of models for the power asymmetry and show
that consistent models include a modulated scale-dependent isocurvature
contribution to the matter power spectrum or a modulation of the reionization
optical depth, gravitational-wave amplitude, or scalar spectral index. We
propose further tests to distinguish between the different scenarios.


title: Dynamically corrected gates for an exchange-only qubit

abstract:
  We provide analytical composite pulse sequences that perform dynamical
decoupling concurrently with arbitrary rotations for a qubit coded in the spin
state of a triple quantum dot. The sequences are designed to respect realistic
experimental constraints such as strictly nonnegative couplings. Logical errors
and leakage errors are simultaneously corrected. A short pulse sequence is
presented to compensate nuclear noise and a longer sequence is presented to
simultaneously compensate nuclear and charge noise. The capability developed in
this work provides a clear prescription for combatting the relevant sources of
noise that currently hinder exchange-only qubit experiments.


title: Blazar candidates beyond redshift 4 observed with GROND

abstract:
  The search for extremely massive high redshift blazars is essential to put
strong constraints on the supermassive black holes formation theories. Up to
now, the few blazars known to have a redshift larger than 4 have been
discovered serendipitously. We try a more systematic approach. Assuming
radio-loudness as a proxy for the jet orientation, we select a sample of
extremely radio-loud quasars. We measure their black hole masses with a method
based on fitting the thermal emission from the accretion disc. We achieve a
precision of a factor of two for our measures, thanks to the observations
performed with the Gamma-Ray Burst Optical Near-Infrared Detector (GROND). The
infrared to optical GROND data allow us to observe directly the peak of the
disc emission, thus constraining the overall disc luminosity. We obtain a small
range of masses, that peaks at 10^{9.3}Msun. If some of our candidates will be
confirmed as blazars, these results would introduce interesting constraints on
the mass function of extremely massive black holes at very high redshift.
Moreover, all our blazar candidates have high accretion rates. This result,
along with the high masses, opens an interesting view on the need of a fast
growth of the heaviest black holes at very high redshift.


title: Using 1-Jettiness to Measure 2 Jets in DIS 3 Ways

abstract:
  We predict cross sections in deep inelastic scattering (DIS) for the
production of two jets---one along the proton beam direction created by initial
state radiation (ISR) and another created by final state radiation after the
hard collision. Our results include fixed order corrections and a summation of
large logarithms up to next-to-next-to-leading logarithmic (NNLL) accuracy in
resummed perturbation theory. We make predictions for three versions of a DIS
event shape 1-jettiness, each of which constrains hadronic final states to be
well collimated into two jets along the beam and final-state jet directions,
but which differ in their sensitivity to the transverse momentum of the ISR
from the proton beam. We use the tools of soft collinear effective theory
(SCET) to derive factorization theorems for these three versions of
1-jettiness. The sensitivity to the ISR gives rise to significantly different
structures in the corresponding factorization theorems---for example,
dependence on either the ordinary or the generalized kperp-dependent beam
function. Despite the differences among 1-jettiness definitions, we show that
the leading nonperturbative correction that shifts the tail region of their
distributions is given by a single universal nonperturbative parameter Omega1,
even accounting for hadron mass effects. Finally, we give numerical results for
Q^2 and x values explored at the HERA collider, emphasizing that the target of
our factorization-based analyses is to open the door for higher-precision jet
phenomenology in DIS.


title: Beta Decays and Non-Standard Interactions in the LHC Era

abstract:
  We consider the role of precision measurements of beta decays and light meson
semi-leptonic decays in probing physics beyond the Standard Model in the LHC
era. We describe all low-energy charged-current processes within and beyond the
Standard Model using an effective field theory framework. We first discuss the
theoretical hadronic input which in these precision tests plays a crucial role
in setting the baseline for new physics searches. We then review the current
and upcoming constraints on the various non-standard operators from the study
of decay rates, spectra, and correlations in a broad array of light-quark
systems. We finally discuss the interplay with LHC searches, both within models
and in an effective theory approach. Our discussion illustrates the independent
yet complementary nature of precision beta decay measurements as probes of new
physics, showing them to be of continuing importance throughout the LHC era.


title: Local Superfluidity at the Nanoscale

abstract:
  We have performed quantum Monte Carlo simulations measuring the finite size
and temperature superfluid response of helium-4 to the linear and rotational
motion of the walls of a nanopore. Within the two-fluid model, the portion of
the normal liquid dragged along with the boundaries is dependent on the type of
motion and the resulting anisotropic superfluid density saturates far below
unity at T=0.5 K. The origin of the saturation is uncovered by computing the
spatial distribution of superfluidity, with only the core of the nanopore
exhibiting any evidence of phase coherence. The superfluid core displays
scaling behavior consistent with Luttinger liquid theory, thereby providing an
experimental test for the emergence of a one dimensional quantum liquid.


title: Entanglement Entropy at Large Central Charge

abstract:
  Two-dimensional conformal field theories with a large central charge and a
small number of low-dimension operators are studied using the conformal block
expansion. A universal formula is derived for the Renyi entropies of N disjoint
intervals in the ground state, valid to all orders in a series expansion. This
is possible because the full perturbative answer in this regime comes from the
exchange of the stress tensor and other descendants of the vacuum state.
Therefore, the Renyi entropy is related to the Virasoro vacuum block at large
central charge. The entanglement entropy, computed from the Renyi entropy by an
analytic continuation, decouples into a sum of single-interval entanglements.
This field theory result agrees with the Ryu-Takayanagi formula for the
holographic entanglement entropy of a 2d CFT, applied to any number of
intervals, and thus can be interpreted as a microscopic calculation of the area
of minimal surfaces in 3d gravity.


title:
Edge-Ferromagnetism from Majorana Flat-Bands: Application to Split
  Tunneling-Conductance Peaks in the High-Tc Cuprates

abstract:
  In mean-field descriptions of nodal d-wave superconductors, generic edges
exhibit dispersionless Majorana fermion bands at zero-energy. These states give
rise to an extensive ground-state degeneracy, and are protected by
time-reversal (TR) symmetry. We argue that the infinite density of states of
these flat-bands make them inherently unstable to interactions, and show that
repulsive interactions lead to edge FM which splits the flat bands. This edge
FM offers an explanation for the observation of splitting of zero-bias peaks in
edge tunneling in High-Tc cuprate superconductors. We argue that this mechanism
for splitting is more likely than previously proposed scenarios, and describe
its experimental consequences.


title: WFIRST Planet Masses from Microlens Parallax

abstract:
  I present a method using only a few ground-based observations of magnified
microlensing events to routinely measure the parallaxes of WFIRST events if
WFIRST is in an L2 orbit. This could be achieved for all events with Amax > 30
using target-ofopportunity observations of select WFIRST events, or with a
complementary, ground-based survey of the WFIRST field, which can push beyond
this magnification limit. When combined with a measurement of the angular size
of the Einstein ring, which is almost always measured in planetary events,
these parallax measurements will routinely give measurements of the lens masses
and hence, the absolute masses of the planets. They can also lead to mass
measurements for dark, isolated objects such as brown dwarfs, free-floating
planets, and stellar remnants if the size of the Einstein ring is measured.


title:
Super-luminous X-ray Emission from the Interaction of Supernova Ejecta
  with Dense Circumstellar Shells

abstract:
  For supernova powered by the conversion of kinetic energy into radiation due
to the interactions of the ejecta with a dense circumstellar shell, we show
that there could be X-ray analogues of optically super-luminous SNe with
comparable luminosities and energetics. We consider X-ray emission from the
forward shock of SNe ejecta colliding into an optically-thin CSM shell, derive
simple expressions for the X-ray luminosity as a function of the circumstellar
shell characteristics, and discuss the different regimes in which the shock
will be radiative or adiabatic, and whether the emission will be dominated by
free-free radiation or line-cooling. We find that even with normal supernova
explosion energies of 10^51 erg, there exists CSM shell configurations that can
liberate a large fraction of the explosion energy in X-rays, producing
unabsorbed X-ray luminosities approaching 10^44 erg/s events lasting a few
months, or even 10^45 erg/s flashes lasting days. Although the large column
density of the circumstellar shell can absorb most of the flux from the initial
shock, the most luminous events produce hard X-rays that are less susceptible
to photoelectric absorption, and can counteract such losses by completely
ionizing the intervening material. Regardless, once the shock traverses the
entire circumstellar shell, the full luminosity could be available to
observers.


title:
Cosmological Zoom Simulations of z = 2 Galaxies: The Impact of Galactic
  Outflows

abstract:
  We use high-resolution cosmological zoom simulations with ~200 pc resolution
at z = 2 and various prescriptions for galactic outflows in order to explore
the impact of winds on the morphological, dynamical, and structural properties
of eight individual galaxies with halo masses ~ 10^11--2x10^12 Msun at z = 2.
We present a detailed comparison to spatially and spectrally resolved H{\alpha}
and other observations of z ~ 2 galaxies. We find that simulations without
winds produce massive, compact galaxies with low gas fractions, super-solar
metallicities, high bulge fractions, and much of the star formation
concentrated within the inner kpc. Strong winds are required to maintain high
gas fractions, redistribute star-forming gas over larger scales, and increase
the velocity dispersion of simulated galaxies, more in agreement with the
large, extended, turbulent disks typical of high-redshift star-forming
galaxies. Winds also suppress early star formation to produce high-redshift
cosmic star formation efficiencies in better agreement with observations.
Sizes, rotation velocities, and velocity dispersions all scale with stellar
mass in accord with observations. Our simulations produce a diversity of
morphological characteristics - among our three most massive galaxies, we find
a quiescent grand-design spiral, a very compact star-forming galaxy, and a
clumpy disk undergoing a minor merger; the clumps are evident in H{\alpha} but
not in the stars. Rotation curves are generally slowly rising, particularly
when calculated using azimuthal velocities rather than enclosed mass. Our
results are broadly resolution-converged. These results show that cosmological
simulations including outflows can produce disk galaxies similar to those
observed during the peak epoch of cosmic galaxy growth.


title:
Finding Core Collapse Supernova from the Epoch of Reionization Behind
  Cluster Lenses

abstract:
  Current surveys are underway to utilize gravitational lensing by galaxy
clusters with Einstein radii >35" in the search for the highest redshift
galaxies. Associated supernova from the epoch of reionization would have their
fluxes boosted above the detection threshold, extending their duration of
visibility. We predict that the James Webb Space Telescope (JWST) will be able
to discover lensed core-collapse supernovae at redshifts exceeding z=7-8.


title:
Are Super-Luminous supernovae and Long GRBs produced exclusively in
  young dense star clusters?

abstract:
  Super Luminous supernovae (SLSN) occur almost exclusively in small galaxies
(SMC/LMC-like or smaller), and the few SLSN observed in larger star-forming
galaxies always occur close to the nuclei of their hosts. Another type of
peculiar and highly energetic supernovae are the broad-line type Ic SNe (SN
Ic-BL) that are associated with long-duration gamma-ray bursts (LGRBs). Also
these have a strong preference for occurring in small (SMC/LMC-like or smaller)
star-forming galaxies, and in these galaxies LGRBs always occur in the
brightest spots. Studies of nearby star-forming galaxies that are similar to
the hosts of LGRBs show that these brightest spots are giant HII regions
produced by massive dense young star clusters with many hundreds of O- and
Wolf-Rayet-type stars. Such dense young clusters are also found in abundance
within a few hundred parsecs from the nucleus of larger galaxies like our own.
We argue that the SLSN and the SN Ic-BL/LGRBs are exclusive products of two
types of dynamical interactions in dense young star clusters. In our model the
high angular momentum of the collapsing stellar cores required for the
"engines" of a SN Ic-BL results from the post-main sequence mergers of
dynamically produced cluster binaries with almost equal-mass components. The
merger produces a critically rotating single helium star with sufficent angular
momentum to produce a LGRB; the observed "metal aversio" of LGRBs is a natural
consequence of the model. We argue that, on the other hand, SLSN could be the
products of runaway multiple collisions in dense clusters, and we present (and
quantize) plausible scenarios of how the different types of SLSNs can be
produced.


title: Discrete Symmetries and Neutrino Mass Perturbations for \theta_{13}

abstract:
  The recent measurement of the third lepton mixing angle, \theta_{13}, has
shown that, although small compared to \theta_{12} and \theta_{23}, it is much
larger than anticipated in schemes that generate Tri-Bi-Maximal (TBM) or Golden
Ratio (GR) mixing. We develop a model-independent formalism for perturbations
away from exact TBM or GR mixing in the neutrino sector. Each resulting
perturbation scheme reflects an underlying symmetry structure and involves a
single complex parameter. We show that such perturbations can readily fit the
observed value of \theta_{13}, which is then correlated with a change in the
other mixing angles. We also determine the implication for the lepton CP
violating phases. For comparison we determine the predictions for Bi-Maximal
mixing corrected by charged lepton mixing and we discuss the accuracy that will
be needed to distinguish between the various schemes.


title:
Gapped and gapless spin liquid phases on the Kagome lattice from chiral
  three-spin interactions

abstract:
  We argue that a relatively simple model containing only SU(2)-invariant
chiral three-spin interactions on a Kagome lattice of S=1/2 spins can give rise
to both a gapped and a gapless quantum spin liquid. Our arguments are rooted in
a formulation in terms of network models of edge states and are backed up by a
careful numerical analysis. For a uniform choice of chirality on the lattice,
we realize the Kalmeyer-Laughlin state, i.e. a gapped spin liquid which is
identified as the nu=1/2 bosonic Laughlin state. For staggered chiralities, a
gapless spin liquid emerges which exhibits gapless spin excitations along lines
in momentum space, a feature that we probe by studying quasi-two-dimensional
systems of finite width. We thus provide a single, appealingly simple spin
model (i) for what is probably the simplest realization of the
Kalmeyer-Laughlin state to date, as well as (ii) for a non-Fermi liquid state
with lines of gapless SU(2) spin excitations.


title: A Predictive Yukawa Unified SO(10) Model: Higgs and Sparticle Masses

abstract:
  We revisit a class of supersymmetric SO(10) models with t-b-tau Yukawa
coupling unification condition, with emphasis on the prediction of the Higgs
mass. We discuss qualitative features in this model that lead to a Higgs mass
prediction close to 125 GeV. We show this with two distinct computing packages,
Isajet and SuSpect, and also show that they yield similar global features in
the parameter space of this model. We find that t-b-tau Yukawa coupling
unification prefers values of the CP-odd Higgs mass m_{A} to be around 600 GeV,
with all colored sparticle masses above 3 TeV. We also briefly discuss
prospects for testing this scenario with the ongoing and planned direct dark
matter detection experiments. In this class of models with t-b-tau Yukawa
unification, the neutralino dark matter particle is heavy
(m_{\tilde{\chi}_1^{0}} \gtrsim 400 \rm \ GeV), which coannihilates with a stau
to yield the correct relic abundance.


title: Full Counting Statistics of Photons Emitted by Double Quantum Dot

abstract:
  We analyze the full counting statistics of photons emitted by a double
quantum dot (DQD) coupled to a high-quality microwave resonator by electric
dipole interaction. We show that at the resonant condition between the energy
splitting of the DQD and the photon energy in the resonator, photon statistics
exhibits both a sub-Poissonian distribution and antibunching. In the ideal
case, when the system decoherence stems only from photodetection, the photon
noise is reduced below one-half of the noise for the Poisson distribution and
is consistent with current noise. The photon distribution remains
sub-Poissonian even at moderate decoherence in the DQD. We demonstrate that
Josephson junction based photomultipliers can be used to experimentally assess
statistics of emitted photons.


title:
An algorithm to estimate unsteady and quasi-steady pressure fields from
  velocity field measurements

abstract:
  We describe and characterize a method for estimating the pressure field
corresponding to velocity field measurements, such as those obtained by using
particle image velocimetry. The pressure gradient is estimated from a time
series of velocity fields for unsteady calculations or from a single velocity
field for quasi-steady calculations. The corresponding pressure field is
determined based on median polling of several integration paths through the
pressure gradient field in order to reduce the effect of measurement errors
that accumulate along individual integration paths. Integration paths are
restricted to the nodes of the measured velocity field, thereby eliminating the
need for measurement interpolation during this step and significantly reducing
the computational cost of the algorithm relative to previous approaches. The
method is validated by using numerically-simulated flow past a stationary,
two-dimensional bluff body and a computational model of a three-dimensional,
self-propelled anguilliform swimmer to study the effects of spatial and
temporal resolution, domain size, signal-to-noise ratio, and out-of-plane
effects. Particle image velocimetry measurements of a freely-swimming jellyfish
medusa and a freely-swimming lamprey are analyzed using the method to
demonstrate the efficacy of the approach when applied to empirical data.


title:
A Catalog of Ultra-compact High Velocity Clouds from the ALFALFA Survey:
  Local Group Galaxy Candidates?

abstract:
  We present a catalog of 59 ultra-compact high velocity clouds (UCHVCs)
extracted from the 40% complete ALFALFA HI-line survey. The ALFALFA UCHVCs have
median flux densities of 1.34 Jy km/s, median angular diameters of 10', and
median velocity widths of 23 km/s. We show that the full UCHVC population
cannot easily be associated with known populations of high velocity clouds. Of
the 59 clouds presented here, only 11 are also present in the compact cloud
catalog extracted from the commensal GALFA-HI survey, demonstrating the utility
of this separate dataset and analysis. Based on their sky distribution and
observed properties, we infer that the ALFALFA UCHVCs are consistent with the
hypothesis that they may be very low mass galaxies within the Local Volume. In
that case, most of their baryons would be in the form of gas, and because of
their low stellar content, they remain unidentified by extant optical surveys.
At distances of ~1 Mpc, the UCHVCs have neutral hydrogen (HI) masses of ~10^5
-10^6 M_sun, HI diameters of ~2-3 kpc, and indicative dynamical masses within
the HI extent of ~10^7 - 10^8 M_sun, similar to the Local Group ultra-faint
dwarf Leo T. The recent ALFALFA discovery of the star-forming, metal-poor, low
mass galaxy Leo P demonstrates that this hypothesis is true in at least one
case. In the case of the individual UCHVCs presented here, confirmation of
their extragalactic nature will require further work, such as the
identification of an optical counterpart to constrain their distance.


title:
Monitoring the Very-Long-Term Variability of X-ray Sources in the Giant
  Elliptical Galaxy M87

abstract:
  We report on our search for very-long-term variability (weeks to years) in
X-ray binaries (XRBs) in the giant elliptical galaxy M87. We have used archival
Chandra imaging observations to characterise the long-term variability of 8 of
the brightest members of the XRB population in M87. The peak brightness of some
of the sources exceeded the ultra luminous X-ray source (ULX) threshold
luminosity of ~ 10^{39} erg/s, and one source could exhibit dips or eclipses.
We show that for one source, if it has similar modulation amplitude as in
SS433, then period recoverability analysis on the current data would detect
periodic modulations, but only for a narrow range of periods less than 120
days. We conclude that a dedicated monitoring campaign, with appropriately
defined sampling, is essential if we are to investigate properly the nature of
the long-term modulations such as those seen in Galactic sources.


title: The affine-null metric formulation of Einstein's equations

abstract:
  The details are presented of a new evolution algorithm for the characteristic
initial-boundary value problem based upon an affine parameter rather than the
areal radial coordinate used in the Bondi-Sachs formulation. The advantages
over the Bondi-Sachs version are discussed, with particular emphasis on the
application to the characteristic extraction of the gravitational waveform from
Cauchy simulations of general relativistic astrophysical systems.


title:
F-Theory Compactifications with Multiple U(1)-Factors: Constructing
  Elliptic Fibrations with Rational Sections

abstract:
  We study F-theory compactifications with U(1)xU(1) gauge symmetry on
elliptically fibered Calabi-Yau manifolds with a rank two Mordell-Weil group.
We find that the natural presentation of an elliptic curve E with two rational
points and a zero point is the generic Calabi-Yau onefold in dP_2. We determine
the birational map to its Tate and Weierstrass form and the coordinates of the
two rational points in Weierstrass form. We discuss its resolved elliptic
fibrations over a general base B and classify them in the case of B=P^2. A
thorough analysis of the generic codimension two singularities of these
elliptic Calabi-Yau manifolds is presented. This determines the general
U(1)xU(1)-charges of matter in corresponding F-theory compactifications. The
matter multiplicities for the fibration over P^2 are determined explicitly and
shown to be consistent with anomaly cancellation. Explicit toric examples are
constructed, both with U(1)xU(1) and SU(5)xU(1)xU(1) gauge symmetry. As a
by-product, we prove the birational equivalence of the two elliptic fibrations
with elliptic fibers in the two blow-ups Bl_(1,0,0)P^2(1,2,3) and
Bl_(0,1,0)P^2(1,1,2) employing birational maps and extremal transitions.


title: Composite Toffoli gate with two-round error detection

abstract:
  We introduce a fault-tolerant construction to implement a composite quantum
operation of four overlapping Toffoli gates. The same construction can produce
two independent Toffoli gates. This result lowers resource overheads in designs
for quantum computers by more than an order of magnitude. The procedure uses
Clifford operations and 64 copies of the non-Clifford gate $T = \exp[i \pi (I -
\sigma^z) /8]$. Quantum codes detect errors in the circuit. When the dominant
source of error is $T$-gate failure with probability $p$, then the composite
Toffoli circuit has postselected failure rate of $3072p^4$ to lowest order.


title: The Quantum Variance of the Modular Surface

abstract:
  The variance of observables of quantum states of the Laplacian on the modular
surface is calculated in the semiclassical limit. It is shown that this
hermitian form is diagonalized by the irreducible representations of the
modular quotient and on each of these it is equal to the classical variance of
the geodesic flow after the insertion of a subtle arithmetical special value of
the corresponding $L$-function.


title:
Realizations of the three point algebra $\mathfrak{sl}(2, \mathcal R)
  \oplus\left(\Omega_{\mathcal R}/d{\mathcal R}\right)$

abstract:
  We describe the universal central extension of the three point current
algebra $\mathfrak{sl}(2,\mathcal R)$ where $\mathcal R=\mathbb
C[t,t^{-1},u\,|\,u^2=t^2+4t ]$ and construct realizations of it in terms of
sums of partial differential operators.


title: Observation of the geometric spin Hall effect of light

abstract:
  The spin Hall effect of light (SHEL) is the photonic analogue of spin Hall
effects occurring for charge carriers in solid-state systems. Typical examples
of this intriguing phenomenon occur when a light beam refracts at an air-glass
interface, or when it is projected onto an oblique plane, the latter effect
being known as geometric SHEL. It amounts to a polarization-dependent
displacement perpendicular to the plane of incidence. Here, we experimentally
demonstrate the geometric SHEL for a light beam transmitted across an oblique
polarizer. We find that the spatial intensity distribution of the transmitted
beam depends on the incident state of polarization and its centroid undergoes a
positional displacement exceeding one wavelength. This novel phenomenon is
virtually independent from the material properties of the polarizer and, thus,
reveals universal features of spin-orbit coupling.


title:
Possible Emission of Cosmic $X$-- and $\gamma$--rays by Unstable
  Particles at Late Times

abstract:
  Not all astrophysical mechanisms of the emission of electromagnetic radiation
including $X$-- and $\gamma$-- rays coming from the space are clear. We find
that charged unstable particles as well as neutral unstable particles with
non--zero magnetic moment which live sufficiently long may emit electromagnetic
radiation. This new mechanism is connected with the properties of unstable
particles at the post exponential time region. Analyzing the transition time
region between exponential and non-exponential form of the survival amplitude
it is found that the instantaneous energy of the unstable particle can take
very large values, much larger than the energy of this state for times from the
exponential time region. Basing on the results obtained for the model
considered, it is shown that this purely quantum mechanical effect may be
responsible for causing unstable particles to emit electromagnetic--, $X$-- or
$\gamma$--rays at some time intervals from the transition time regions.


title: The reduction of qualitative games

abstract:
  We extend the study of the iterated elimination of strictly dominated
strategies (IESDS) from Nash strategic games to a class of qualitative games.
Also in this case, the IESDS process leads us to a kind of 'rationalizable'
result. We define several types of dominance relation and game reduction and
establish conditions under which a unique and nonempty maximal reduction
exists. We generalize, in this way, some results due to Dufwenberg and Stegeman
(2002) and Apt (2007).


title: ABC Reinforcement Learning

abstract:
  This paper introduces a simple, general framework for likelihood-free
Bayesian reinforcement learning, through Approximate Bayesian Computation
(ABC). The main advantage is that we only require a prior distribution on a
class of simulators (generative models). This is useful in domains where an
analytical probabilistic model of the underlying process is too complex to
formulate, but where detailed simulation models are available. ABC-RL allows
the use of any Bayesian reinforcement learning technique, even in this case. In
addition, it can be seen as an extension of rollout algorithms to the case
where we do not know what the correct model to draw rollouts from is. We
experimentally demonstrate the potential of this approach in a comparison with
LSPI. Finally, we introduce a theorem showing that ABC is a sound methodology
in principle, even when non-sufficient statistics are used.


title:
Unveiling the cosmological QCD phase transition through the eLISA/NGO
  detector

abstract:
  We study the evolution of turbulence in the early universe at the QCD epoch
using a state-of-the-art equation of state derived from lattice QCD
simulations. Since the transition is a crossover we assume that temperature and
velocity fluctuations were generated by some event in the previous history of
the Universe and survive until the QCD epoch due to the extremely large
Reynolds number of the primordial fluid. The fluid at the QCD epoch is assumed
to be non-viscous, based on the fact that the viscosity per entropy density of
the quark gluon plasma obtained from heavy-ion collision experiments at the
RHIC and the LHC is extremely small.
  Our hydrodynamic simulations show that the velocity spectrum is very
different from the Kolmogorov power law considered in studies of primordial
turbulence that focus on first order phase transitions. This is due to the fact
that there is no continuous injection of energy in the system and the viscosity
of the fluid is negligible. Thus, as kinetic energy cascades from the larger to
the smaller scales, a large amount of kinetic energy is accumulated at the
smallest scales due to the lack of dissipation.
  We have obtained the spectrum of the gravitational radiation emitted by the
motion of the fluid finding that, if typical velocity and temperature
fluctuations have an amplitude $(\Delta v) /c \gtrsim 10^{-2}$ and/or $\Delta
T/T_c \gtrsim 10^{-3}$, they would be detected by eLISA at frequencies larger
than $\sim 10^{-4}$ Hz.


title: Equilibrium existence results for a class of discontinuous games

abstract:
  We introduce the notions of w-lower semicontinuous and almost w-lower
semicontinuous correspondence with respect to a given set and prove a new
fixed-point theorem. We also introduce the notion of correspondence with
e-LSCS-property. As applications we obtain some new equilibrium theorems for
abstract economies and for generalized multiobjective games.


title: Analysis of Spin-Orbit Misalignment in Eclipsing Binary DI Herculis

abstract:
  Eclipsing binary DI Herculis (DI Her) is known to exhibit anomalously slow
apsidal precession, below the rate predicted by the general relativity. Recent
measurements of the Rossiter-McLauglin effect indicate that stellar spins in DI
Her are almost orthogonal to the orbital angular momentum, which explains the
anomalous precession in agreement with the earlier theoretical suggestion by
Shakura. However, these measurements yield only the projections of the
spin-orbit angles onto the sky plane, leaving the spin projection onto our line
of sight unconstrained. Here we describe a method of determining the full
three-dimensional spin orientation of the binary components relying on the use
of the gravity darkening effect, which is significant for the rapidly rotating
stars in DI Her. Gravity darkening gives rise to nonuniform brightness
distribution over the stellar surface, the pattern of which depends on the
stellar spin orientation. Using archival photometric data obtained during
multiple eclipses spread over several decades we are able to constrain the
unknown spin angles in DI Her with this method, finding that spin axes of both
stars lie close to the plane of the sky. Our procedure fully accounts for the
precession of stellar spins over the long time span of observations.


title: Coherence of countably many bets

abstract:
  De Finetti's betting argument is used to justify finitely additive
probabilities when only finitely many bets are considered. Under what
circumstances can countably many bets be used to justify countable additivity?
In this framework, one faces issues such as the convergence of the returns of
the bet. Generalizations of de Finetti's argument depend on what type of
conditions on convergence are required of the bets under consideration. Two new
such conditions are compared with others presented in the literature.


title: Fixed Point Theorems and applications in Theory of Games

abstract:
  We introduce the notions of weakly *-concave and weakly naturally
quasi-concave correspondence and prove fixed point theorems and continuous
selection theorems for these kind of correspondences. As applications in the
game theory, by using a tehnique based on a continuous selection, we establish
new existence results for the equilibrium of the abstract economies. The
constraint correspondences are weakly naturally quasi-concave. We show that the
equilibrium exists without continuity assumptions.


title: Quantum Catalysis of Magnetic Phase Transitions in a Quantum Simulator

abstract:
  We control quantum fluctuations to create the ground state magnetic phases of
a classical Ising model with a tunable longitudinal magnetic field using a
system of 6 to 10 atomic ion spins. Due to the long-range Ising interactions,
the various ground state spin configurations are separated by multiple
first-order phase transitions, which in our zero temperature system cannot be
driven by thermal fluctuations. We instead use a transverse magnetic field as a
quantum catalyst to observe the first steps of the complete fractal devil's
staircase, which emerges in the thermodynamic limit and can be mapped to a
large number of many-body and energy-optimization problems.


title:
Application of machine learning algorithms to the study of noise
  artifacts in gravitational-wave data

abstract:
  The sensitivity of searches for astrophysical transients in data from the
LIGO is generally limited by the presence of transient, non-Gaussian noise
artifacts, which occur at a high-enough rate such that accidental coincidence
across multiple detectors is non-negligible. Furthermore, non-Gaussian noise
artifacts typically dominate over the background contributed from stationary
noise. These "glitches" can easily be confused for transient gravitational-wave
signals, and their robust identification and removal will help any search for
astrophysical gravitational-waves. We apply Machine Learning Algorithms (MLAs)
to the problem, using data from auxiliary channels within the LIGO detectors
that monitor degrees of freedom unaffected by astrophysical signals. The number
of auxiliary-channel parameters describing these disturbances may also be
extremely large; an area where MLAs are particularly well-suited. We
demonstrate the feasibility and applicability of three very different MLAs:
Artificial Neural Networks, Support Vector Machines, and Random Forests. These
classifiers identify and remove a substantial fraction of the glitches present
in two very different data sets: four weeks of LIGO's fourth science run and
one week of LIGO's sixth science run. We observe that all three algorithms
agree on which events are glitches to within 10% for the sixth science run
data, and support this by showing that the different optimization criteria used
by each classifier generate the same decision surface, based on a
likelihood-ratio statistic. Furthermore, we find that all classifiers obtain
similar limiting performance, suggesting that most of the useful information
currently contained in the auxiliary channel parameters we extract is already
being used.


title: Counting The Generator Matrices of $\mathbb{Z}_{2}\mathbb{Z}_{8}$-Codes

abstract:
  In this paper, we count the number of matrices whose rows generate different
$\mathbb{Z}_2\mathbb{Z}_8$ additive codes. This is a natural generalization of
the well known Gaussian numbers that count the number of matrices whose rows
generate vector spaces with particular dimension over finite fields. Due to
this similarity we name this numbers as Mixed Generalized Gaussian Numbers
(MGN). The MGN formula by specialization leads to the well known formula for
the number of binary codes and the number of codes over $\mathbb{Z}_8,$ and for
additive $\mathbb{Z}_2\mathbb{Z}_4$ codes. Also, we conclude by some properties
and examples of the MGN numbers that provide a good source for new number
sequences that are not listed in The On-Line Encyclopedia of Integer Sequences.


title:
Possible valence-bond condensation in the frustrated cluster magnet
  LiZn2Mo3O8

abstract:
  The emergence of complex electronic behaviour from simple ingredients has
resulted in the discovery of numerous states of matter. Many examples are found
in systems exhibiting geometric magnetic frustration, which prevents
simultaneous satisfaction of all magnetic interactions. This frustration gives
rise to complex magnetic properties such as chiral spin structures
orbitally-driven magnetism, spin-ice behavior exhibiting Dirac strings with
magnetic monopoles, valence bond solids, and spin liquids. Here we report the
synthesis and characterization of LiZn2Mo3O8, a geometrically frustrated
antiferromagnet in which the magnetic moments are localized on small transition
metal clusters rather than individual ions. By doing so, first order
Jahn-Teller instabilities and orbital ordering are prevented, allowing the
strongly interacting magnetic clusters in LiZn2Mo3O8 to probably give rise to
an exotic condensed valence-bond ground state reminiscent of the proposed
resonating valence bond state. Our results also link magnetism on clusters to
geometric magnetic frustration in extended solids, demonstrating a new approach
for unparalleled chemical control and tunability in the search for collective,
emergent electronic states of matter.


title:
X-ray imaging and multiferroic coupling of cycloidal magnetic domains in
  ferroelectric monodomain BiFeO3

abstract:
  Magnetic domains at the surface of a ferroelectric monodomain BiFeO3 single
crystal have been imaged by hard X-ray magnetic scattering. Magnetic domains up
to several hundred microns in size have been observed, corresponding to
cycloidal modulations of the magnetization along the wave-vector
k=2\pi(\delta,\delta,0) and symmetry equivalent directions. The rotation
direction of the magnetization in all magnetic domains, determined by
diffraction of circularly polarized light, was found to be unique and in
agreement with predictions of a combined approach based on a spin-model
complemented by relativistic density-functional simulations. Imaging of the
surface shows that the largest adjacent domains display a 120 degree vortex
structure.


title:
A Solution Accurate, Efficient and Stable Unsplit Staggered Mesh Scheme
  for Three Dimensional Magnetohydrodynamics

abstract:
  In this paper, we extend the unsplit staggered mesh scheme (USM) for 2D
magnetohydrodynamics (MHD) (Lee and Deane, 2009) to a full 3D MHD scheme. The
scheme is a finite-volume Godunov method consisting of a constrained transport
(CT) method and an efficient and accurate single-step, directionally unsplit
multidimensional data reconstruction-evolution algorithm, which extends the
original 2D corner transport upwind (CTU) method (Colella, 1990). We present
two types of data reconstruction-evolution algorithms for 3D: (1) a reduced CTU
scheme and (2) a full CTU scheme. The reduced 3D CTU scheme is a variant of a
simple 3D extension of the 2D CTU method by Colella (1990) and is considered as
a direct extension from the 2D USM scheme. The full 3D CTU scheme is our
primary 3D solver which includes all multidimensional cross-derivative terms
for stability. The latter method is logically analogous to the 3D unsplit CTU
method by Saltzman. The major novelties in our algorithms are twofold. First,
we extend the reduced CTU scheme to the full CTU scheme which is able to run
with CFL numbers close to unity. Both methods utilize the transverse update
technique developed in the 2D USM algorithm to account for transverse fluxes
without solving intermediate Riemann problems, which in turn gives
cost-effective 3D methods by reducing the total number of Riemann solves. The
proposed algorithms are simple and efficient especially when including
multidimensional MHD terms that maintain in-plane magnetic field dynamics.
Second, we introduce a new CT scheme that makes use of proper upwind
information in taking averages of electric fields.


title: Recognizing mapping spaces

abstract:
  Given a fixed object $A$ in a suitable pointed simplicial model category
$\C$, we study the problem of recovering the target $Y$ from the pointed
mapping space \w{\mapa(A,Y)} (up to $A$-equivalence). We describe a recognition
principle, modelled on the classical ones for loop spaces, but using the more
general notion of an \emph{\Ama[.]} It has an associated transfinite procedure
for recovering \w{\CWA Y} from \w[,]{\mapa(A,Y)} inspired by Dror-Farjoun's
construction of \ww{\CWA{}}-approximations.


title: The Complete Positivity of Classical Polarization Maps

abstract:
  Mueller and Jones matrices have been thoroughly studied as mathematical tools
to describe the manipulation of the polarization state of classical light. In
particular, the most general physical transformation on the polarization state
has been represented as an ensemble of Jones matrices, as $\sum_i V_i \Phi
V^{\dagger}_i$. But this has generally been directly assumed without proof by
most authors. In this Letter, we derive this expression from simple physical
principles and the matrix theory of positive maps.


title: On the maximal reduction of games

abstract:
  We study the conditions under which the iterated elimination of strictly
dominated strategies is order independent and we identify a class of
discontinuous games for which order does not matter. In this way, we answer the
open problem raised by M. Dufwenberg and M. Stegeman (2002) and generalize
their main results. We also establish new theorems concerning the existence and
uniqueness of the maximal game reduction when the pure strategies are dominated
by mixed strategies.


title:
Parameter tuning for a multi-fidelity dynamical model of the
  magnetosphere

abstract:
  Geomagnetic storms play a critical role in space weather physics with the
potential for far reaching economic impacts including power grid outages, air
traffic rerouting, satellite damage and GPS disruption. The LFM-MIX is a
state-of-the-art coupled magnetospheric-ionospheric model capable of simulating
geomagnetic storms. Imbedded in this model are physical equations for turning
the magnetohydrodynamic state parameters into energy and flux of electrons
entering the ionosphere, involving a set of input parameters. The exact values
of these input parameters in the model are unknown, and we seek to quantify the
uncertainty about these parameters when model output is compared to
observations. The model is available at different fidelities: a lower fidelity
which is faster to run, and a higher fidelity but more computationally intense
version. Model output and observational data are large spatiotemporal systems;
the traditional design and analysis of computer experiments is unable to cope
with such large data sets that involve multiple fidelities of model output. We
develop an approach to this inverse problem for large spatiotemporal data sets
that incorporates two different versions of the physical model. After an
initial design, we propose a sequential design based on expected improvement.
For the LFM-MIX, the additional run suggested by expected improvement
diminishes posterior uncertainty by ruling out a posterior mode and shrinking
the width of the posterior distribution. We also illustrate our approach using
the Lorenz `96 system of equations for a simplified atmosphere, using known
input parameters. For the Lorenz `96 system, after performing sequential runs
based on expected improvement, the posterior mode converges to the true value
and the posterior variability is reduced.


title:
The coupling of thermodynamics with the organizational water-protein
  intra-dynamics driven by the H-bonds dissipative potential of cluster water

abstract:
  The Red cell-Hb-CSF functions as a sensor adapting response to Hb
heterotropic equilibriums. At the lungs O2 and Mg2+, each one increasing
affinity for the other stabilize the relax (R) form [(O2)4Hb(Mg)2].(H2O)R. At
tissue level, the inclusion of H+ and 2,3-DPG excludes O2 and Mg2+ to stabilize
the tense (T) form 2,3-DPG-deoxyHb-(H2O)T. Both senses are integrated into a
cycle T into R and R into T, without involving a direct reversal. The
dissipative potential of water cluster (H2O)n interacts with the hydrophilic
asymmetries of Hb, to restrict randomness of the kinetic sense implicated in a
single peak for activation energy (Ea). The hydration shells could sequence an
enhanced Ea into several peaks, to sequentially activate transitions states.
Hence, changes in dipole state, sliding, pKa, n-H-bonds, etc., could became
concatenated for vectoriality. (H2O)n by the loss of H-bonds couple with to the
hydration turnover of proteins and ions to result in incomplete water cluster
(H2O)n*, with a lower-n. (H2O)n* became a carrier of heat/entropy into the
cerebrospinal fluid (CSF) which has to be replaced 3.7 times per day. OxyHb
formation involves sliding-down of alpha vs beta chains, to shift alpha1 and
alpha2 Pro 44 into allowing the entrance of a fully hydrated
[Mg.(H2O)6](H2O)12-14(2+) (or Zn2+) into the hydrophilic beta2-alpha1 and
beta1-alpha2 interfaces. OxyHb pKa of 6.4 leads to H+-dissociation increasing
negative charge of R-groups. This at beta2-alpha1 sequence two tetradentate
chelates, first an Mg2+, bonding with beta2 His 92 and a second Mg2+ with
alpha1 His 87, to cooperatively release hindrance. The interconversion of
oxy-to-deoxyHb, pKa=8, leads to the amphoteric imidazole to became positively
charged and proximal histidines return into hindrance position, releasing the
incomplete hydrated Mg.(H2O)inc(2+) and O2 into CSF.


title:
Strongly anisotropic spin response as a signature of the helical regime
  in Rashba nanowires

abstract:
  Rashba nanowires in a magnetic field exhibit a helical regime when the
spin-orbit momentum is close to the Fermi momentum, k_F \approx k_{SO}. We show
that this regime is characterized by a strongly anisotropic electron spin
susceptibility, with an exponentially suppressed signal along one direction in
spin space, and that there are no low frequency spin fluctuations along this
direction. Since the spin response in the gapless regime k_F \not \approx
k_{SO} has a power law behavior in all three directions, spin measurements
provide a signature of the helical regime that complements spin-insensitive
conductance measurements.


title: Muon g-2 and 125 GeV Higgs in Split-Family Supersymmetry

abstract:
  We discuss the minimal supersymmetric standard model with "split-family"
spectrum where the sfermions in the first two generations are in the hundreds
GeV to a TeV range while the sfermions in the third generation are in the range
of tens TeV. With the split-family spectrum, the deviation of the muon g-2 and
the observed Higgs boson mass are explained simultaneously. It is predicted
that the gluino and the squarks in the first two generations are within the
reach of the LHC experiments in most favored parameter space for the universal
gaugino mass, which can be tested by searching for events with missing
transverse energy or events with stable charged massive particles. We also
point out that the split-family scenario can be consistent with the focus point
scenario for the non-universal gaugino masses where the required mu-term is in
the hundreds GeV range.


title:
Electromagnetically-induced transparency in a diamond spin ensemble
  enables all-optical electromagnetic field sensing

abstract:
  We use electromagnetically-induced transparency (EIT) to probe the narrow
electron-spin resonance of nitrogen-vacancy centers in diamond. Working with a
multi-pass diamond chip at temperatures 6-30 K, the zero-phonon absorption line
(637 nm) exhibits an optical depth of 6 and inhomogenous linewidth of ~30 GHz
full-width-at-half-maximum (FWHM). Simultaneous optical excitation at two
frequencies separated by the ground-state zero-field splitting (2.88 GHz),
reveals EIT resonances with a contrast exceeding 6% and FWHM down to 0.4 MHz.
The resonances provide an all-optical probe of external electric and magnetic
fields with a projected photon-shot-noise-limited sensitivity of 0.2
V/cm/sqrt(Hz) and 0.1 nT/sqrt(Hz), respectively. Operation of a prototype
diamond-EIT magnetometer measures a noise floor of less than 1 nT/sqrt(Hz) for
frequencies above 10 Hz and Allan deviation of 1.3 +/- 1.1 nT for 100 s
intervals. The results demonstrate the potential of diamond-EIT devices for
applications ranging from quantum-optical memory to few-photon nonlinear
optics, precision measurement, and tests of fundamental physics.

categories: physics.optics cond-mat.mtrl-sci physics.atom-ph physics.ins-det quant-ph


title: Gaussian Beam Collimation via Transformation Media

abstract:
  Conventional method for Gaussian beam collimation is to expand the beam waist
to achieve a smaller divergence angle. Recent transformation optics offers an
unconventional path to control the electromagnetic field. In this paper we show
that a Gaussian beam can be converted into a plane wave-like beam by
transformation media within the scale of several wavelengths. Design details
and full-wave simulation results via finite element method are provided.


abstract:
  We study ACM bundles on cubic fourfolds containing a plane exploiting the
geometry of the associated quadric fibration and Kuznetsov's treatment of their
bounded derived categories of coherent sheaves. More precisely, we recover the
K3 surface naturally associated to the fourfold as a moduli space of Gieseker
stable ACM bundles of rank four.


title: Exponential ergodicity for Markov processes with random switching

abstract:
  We study a Markov process with two components: the first component evolves
according to one of finitely many underlying Markovian dynamics, with a choice
of dynamics that changes at the jump times of the second component. The second
component is discrete and its jump rates may depend on the position of the
whole process. Under regularity assumptions on the jump rates and Wasserstein
contraction conditions for the underlying dynamics, we provide a concrete
criterion for the convergence to equilibrium in terms of Wasserstein distance.
The proof is based on a coupling argument and a weak form of the Harris
theorem. In particular, we obtain exponential ergodicity in situations which do
not verify any hypoellipticity assumption, but are not uniformly contracting
either. We also obtain a bound in total variation distance under a suitable
regularising assumption. Some examples are given to illustrate our result,
including a class of piecewise deterministic Markov processes.


title:
Index Coding Capacity: How far can one go with only Shannon
  Inequalities?

abstract:
  An interference alignment perspective is used to identify the simplest
instances (minimum possible number of edges in the alignment graph, no more
than 2 interfering messages at any destination) of index coding problems where
non-Shannon information inequalities are necessary for capacity
characterization. In particular, this includes the first known example of a
multiple unicast (one destination per message) index coding problem where
non-Shannon information inequalities are shown to be necessary. The simplest
multiple unicast example has 7 edges in the alignment graph and 11 messages.
The simplest multiple groupcast (multiple destinations per message) example has
6 edges in the alignment graph, 6 messages, and 10 receivers. For both the
simplest multiple unicast and multiple groupcast instances, the best outer
bound based on only Shannon inequalities is $\frac{2}{5}$, which is tightened
to $\frac{11}{28}$ by the use of the Zhang-Yeung non-Shannon type information
inequality, and the linear capacity is shown to be $\frac{5}{13}$ using the
Ingleton inequality. Conversely, identifying the minimal challenging aspects of
the index coding problem allows an expansion of the class of solved index
coding problems up to (but not including) these instances.


title:
Rotational suppression of the Tayler instability in stellar radiation
  zones

abstract:
  The study of the magnetic field in stellar radiation zones is an important
topic in modern astrophysics because the magnetic field can play an important
role in several transport phenomena such as mixing and angular momentum
transport. We consider the influence of rotation on stability of a
predominantly toroidal magnetic field in the radiation zone. We find that the
effect of rotation on the stability depends on the magnetic configuration of
the basic state. If the toroidal field increases sufficiently rapidly with the
spherical radius, the instability cannot be suppressed entirely even by a very
fast rotation although the strength of the instability can be significantly
reduced. On the other hand, if the field increases slowly enough with the
radius or decreases, the instability has a threshold and can be completely
suppressed in rapidly rotating stars. We find that in the regions where the
instability is entirely suppressed a particular type of magnetohydrodynamic
waves may exist which are marginally stable.


title:
A Distance-Based Test of Association Between Paired Heterogeneous
  Genomic Data

abstract:
  Due to rapid technological advances, a wide range of different measurements
can be obtained from a given biological sample including single nucleotide
polymorphisms, copy number variation, gene expression levels, DNA methylation
and proteomic profiles. Each of these distinct measurements provides the means
to characterize a certain aspect of biological diversity, and a fundamental
problem of broad interest concerns the discovery of shared patterns of
variation across different data types. Such data types are heterogeneous in the
sense that they represent measurements taken at very different scales or
described by very different data structures. We propose a distance-based
statistical test, the generalized RV (GRV) test, to assess whether there is a
common and non-random pattern of variability between paired biological
measurements obtained from the same random sample. The measurements enter the
test through distance measures which can be chosen to capture particular
aspects of the data. An approximate null distribution is proposed to compute
p-values in closed-form and without the need to perform costly Monte Carlo
permutation procedures. Compared to the classical Mantel test for association
between distance matrices, the GRV test has been found to be more powerful in a
number of simulation settings. We also report on an application of the GRV test
to detect biological pathways in which genetic variability is associated to
variation in gene expression levels in ovarian cancer samples, and present
results obtained from two independent cohorts.


title:
Effective Medium Response of Metallic Nanowire Arrays with a Kerr-type
  Dielectric Host

abstract:
  We derive an effective medium model to characterize the macroscopic
electromagnetic response of metallic nanowire arrays embedded in a host
dielectric with a Kerr-type nonlinear permittivity function. It is shown that
the macroscopic electromagnetic fields are coupled to the conduction current in
the nanowires and to an additional quasi-static potential through a system of
nonlinear equations. We prove that a weak nonlinearity leads to an
electromagnetic response closer to that of an indefinite medium, and to
isofrequency contours with increased hyperbolicity. For high-field intensities
the negative refraction of electromagnetic waves at an air nanowire material
interface is enhanced when the nanowires are embedded in a self-focusing Kerr
medium.


title: Bispectrum in Single-Field Inflation Beyond Slow-Roll

abstract:
  We develop an integral form for the bispectrum in general single-field
inflation whose domain of validity includes models of inflation where the
background evolution is not constrained to be slowly varying everywhere. Our
integral form preserves the squeezed-limit consistency relation, allows for
fast evaluation of the bispectrum for all triangle configurations expediting
the efficient comparison of slow-roll violating models with data, and provides
complete and compact slow-roll expressions correct to first order in slow-roll
parameters. Motivated by the recent Planck results, we consider as an example a
sharp step in the warped-brane tension of DBI inflation and provide analytic
solutions for the peak of the resulting bispectrum. For the step in the warp
that reproduces the oscillations in the power spectrum favored by the Planck
data, the corresponding equilateral bispectrum is both extremely large and
highly scale dependent. The bispectrum serves as a means of distinguishing such
a model from alternative scenarios that generate otherwise indistinguishable
power spectra, such as a step in the potential in canonical single-field
inflation.


title: The micropolar Navier-Stokes equations: A priori error analysis

abstract:
  The unsteady Micropolar Navier-Stokes Equations (MNSE) are a system of
parabolic partial differential equations coupling linear velocity and pressure
with angular velocity: material particles have both translational and
rotational degrees of freedom. We propose and analyze a first order
semi-implicit fully-discrete scheme for the MNSE, which decouples the
computation of the linear and angular velocities, is unconditionally stable and
delivers optimal convergence rates under assumptions analogous to those used
for the Navier-Stokes equations. With the help of our scheme we explore some
qualitative properties of the MNSE related to ferrofluid manipulation and
pumping. Finally, we propose a second order scheme and show that it is almost
unconditionally stable.


title:
Evolutionary stochastic dynamics of speciation and a simple
  genotype-phenotype map for protein binding DNA

abstract:
  Speciation is of fundamental importance to understanding the huge diversity
of life on Earth. In contrast to current phenomenological models, we develop a
biophysically motivated approach to study speciation involving the co-evolution
of protein binding DNA for two geographically isolated populations. Our results
predict that, despite neutral diffusion of hybrids in trait space, smaller
populations have a higher rate of speciation, due to sequence entropy poising
populations more closely to incompatible regions of phenotype space. A key
lesson of this work is that non-trivial contributions of sequence entropy give
rise to a strong population size dependence on speciation rates.


title: Trapped one-dimensional ideal Fermi gas with a single impurity

abstract:
  Properties of a single impurity in a one-dimensional Fermi gas are
investigated in homogeneous and trapped geometries. In a homogeneous system we
use McGuire's expression [J. B. McGuire, J. Math. Phys. 6, 432 (1965)] to
obtain interaction and kinetic energies, as well as the local pair correlation
function. The energy of a trapped system is obtained (i) by generalizing
McGuire expression (ii) within local density approximation (iii) using
perturbative approach in the case of a weakly interacting impurity and (iv)
diffusion Monte Carlo method. We demonstrate that a closed formula based on the
exact solution of the homogeneous case provides a precise estimation for the
energy of a trapped system for arbitrary coupling constant of the impurity even
for a small number of fermions. We analyze energy contributions from kinetic,
interaction and potential components, as well as spatial properties such as the
system size. Finally, we calculate the frequency of the breathing mode. Our
analysis is directly connected and applicable to the recent experiments in
microtraps.


title: Top-seesaw assisted technicolor model with 126 GeV Higgs boson

abstract:
  We discuss a model which involves the top quark condensation and the walking
technicolor. We focus on the scalar boson in such a model from the viewpoint of
the observed scalar boson at the LHC.


title: Significance Variables

abstract:
  Many particle physics analyses which need to discriminate some background
process from a signal ignore event-by-event resolutions of kinematic variables.
Adding this information, as is done for missing momentum significance, can only
improve the power of existing techniques. We therefore propose the use of
significance variables which combine kinematic information with event-by-event
resolutions. We begin by giving some explicit examples of constructing optimal
significance variables. Then, we consider three applications: new heavy gauge
bosons, Higgs to $\tau\tau$, and direct stop squark pair production. We find
that significance variables can provide additional discriminating power over
the original kinematic variables: $\sim$ 20% improvement over $m_T$ in the case
of $H\rightarrow\tau\tau$ case, and $\sim$ 30% impovement over $m_{T2}$ in the
case of the direct stop search.


title:
Abrikosov-Nielsen-Olesen string with Non-Abelian Moduli and "Spin-Orbit"
  Interaction

abstract:
  It is generally believed that the spontaneous breaking of the Poincar\'e
group by flux tubes (strings) generate only two zero modes localized on the
string and associated with the spontaneous breaking of translational invariance
(the so-called Low-Manohar argument). Being perfectly true in many instances it
is nevertheless nonuniversal, and have to be amended in the case of order
parameters carrying spatial indices. We show that under certain circumstances
additional zero (or quasizero) modes can appear due to spin symmetry.


title:
Application of the G-JF Discrete-Time Thermostat for Fast and Accurate
  Molecular Simulations

abstract:
  A new Langevin-Verlet thermostat that preserves the fluctuation-dissipation
relationship for discrete time steps, is applied to molecular modeling and
tested against several popular suites (AMBER, GROMACS, LAMMPS) using a small
molecule as an example that can be easily simulated by all three packages.
Contrary to existing methods, the new thermostat exhibits no detectable changes
in the sampling statistics as the time step is varied in the entire numerical
stability range. The simple form of the method, which we express in the three
common forms (Velocity-Explicit, Stormer-Verlet, and Leap-Frog), allows for
easy implementation within existing molecular simulation packages to achieve
faster and more accurate results with no cost in either computing time or
programming complexity.


title: Unveiling Zeus

abstract:
  Malware family classification is an age old problem that many Anti-Virus (AV)
companies have tackled. There are two common techniques used for
classification, signature based and behavior based. Signature based
classification uses a common sequence of bytes that appears in the binary code
to identify and detect a family of malware. Behavior based classification uses
artifacts created by malware during execution for identification. In this paper
we report on a unique dataset we obtained from our operations and classified
using several machine learning techniques using the behavior-based approach.
Our main class of malware we are interested in classifying is the popular Zeus
malware. For its classification we identify 65 features that are unique and
robust for identifying malware families. We show that artifacts like file
system, registry, and network features can be used to identify distinct malware
families with high accuracy---in some cases as high as 95%.


title:
Quantum percolation and transition point of a directed discrete-time
  quantum walk

abstract:
  Quantum percolation describes the problem of a quantum particle moving
through a disordered system. While certain similarities to classical
percolation exist, the quantum case has additional complexity due to the
possibility of Anderson localisation. Here, we consider a directed
discrete-time quantum walk as a model to study quantum percolation of a
two-state particle on a two-dimensional lattice. Using numerical analysis we
determine the fraction of connected edges required (transition point) in the
lattice for the two-state particle to percolate with finite (non-zero)
probability for three fundamental lattice geometries, finite square lattice,
honeycomb lattice, and nanotube structure and show that it tends towards unity
for increasing lattice sizes. To support the numerical results we also use a
continuum approximation to analytically derive the expression for the
percolation probability for the case of the square lattice and show that it
agrees with the numerically obtained results for the discrete case. Beyond the
fundamental interest to understand the dynamics of a two-state particle on a
lattice (network) with disconnected vertices, our study has the potential to
shed light on the transport dynamics in various quantum condensed matter
systems and the construction of quantum information processing and
communication protocols.

categories: quant-ph cond-mat.dis-nn cond-mat.other cond-mat.stat-mech


title: Post-transient relaxation in graphene after an intense laser pulse

abstract:
  High intensity laser pulses were recently shown to induce a population
inverted transient state in graphene [T. Li et al. Phys. Rev. Lett. 108, 167401
(2012)]. Using a combination of hydrodynamic arguments and a kinetic theory we
determine the post-transient state relaxation of hot, dense, population
inverted electrons towards equilibrium. The cooling rate and charge-imbalance
relaxation rate are determined from the Boltzmann-equation including
electron-phonon scattering. We show that the relaxation of the population
inversion, driven by inter-band scattering processes, is much slower than the
relaxation of the electron temperature, which is determined by intra-band
scattering processes. This insight may be of relevance for the application of
graphene as an optical gain medium.


title:
A Multiobjective State Transition Algorithm for Single Machine
  Scheduling

abstract:
  In this paper, a discrete state transition algorithm is introduced to solve a
multiobjective single machine job shop scheduling problem. In the proposed
approach, a non-dominated sort technique is used to select the best from a
candidate state set, and a Pareto archived strategy is adopted to keep all the
non-dominated solutions. Compared with the enumeration and other heuristics,
experimental results have demonstrated the effectiveness of the multiobjective
state transition algorithm.


title: Phase effects due to beam misalignment on diffraction gratings

abstract:
  All-reflective interferometer configurations have been proposed for the next
generation of gravitational wave detectors, with diffractive elements replacing
transmissive optics. However, an additional phase noise creates more stringent
conditions for alignment stability. A framework for alignment stability with
the use of diffractive elements was required using a Gaussian model. We
successfully create such a framework involving modal decomposition to replicate
small displacements of the beam (or grating) and show that the modal model does
not contain the phase changes seen in an otherwise geometric planewave
approach. The modal decomposition description is justified by verifying
experimentally that the phase of a diffracted Gaussian beam is independent of
the beam shape, achieved by comparing the phase change between a zero-order and
first-order mode beam. To interpret our findings we employ a rigorous
time-domain simulation to demonstrate that the phase changes resulting from a
modal decomposition are correct, provided that the coordinate system which
measures the phase is moved simultaneously with the effective beam
displacement. This indeed corresponds to the phase change observed in the
geometric planewave model. The change in the coordinate system does not
instinctively occur within the analytical framework, and therefore requires
either a manual change in the coordinate system or an addition of the geometric
planewave phase factor.


title:
Metamaterial slab-based super-absorbers and perfect nanodetectors for
  single dipole sources

abstract:
  We propose to use double negative (DNG) metamaterial slabs to build effective
super-absorbers and perfect nanodetectors for single divergent sources. We
demonstrate by numerical simulations that an absorbing nanoparticle properly
placed inside a DNG slab back-covered with a perfect electric conductor or
perfect magnetic conductor mirror can absorb up to 100% radiation energy of a
single dipole source placed outside the slab. Furthermore, we also show that
even the simple DNG slab without any absorbing nanoparticle could be used as a
perfect absorber for both plane and divergent beams. The proposed systems may
focus the radiation in nanoscale and thus have applications in optical
nanodevices for a variety of different purposes.


title: Bridge number and integral Dehn surgery

abstract:
  In a 3-manifold M, let K be a knot and R be an annulus which meets K
transversely. We define the notion of the pair (R,K) being caught by a surface
Q in the exterior of the link given by K and the boundary curves of R. For a
caught pair (R,K), we consider the knot K^n gotten by twisting K n times along
R and give a lower bound on the bridge number of K^n with respect to Heegaard
splittings of M -- as a function of n, the genus of the splitting, and the
catching surface Q. As a result, the bridge number of K^n tends to infinity
with n. In application, we look at a family of knots K^n found by Teragaito
that live in a small Seifert fiber space M and where each K^n admits a Dehn
surgery giving the 3-sphere. We show that the bridge number of K^n with respect
to any genus 2 Heegaard splitting of M tends to infinity with n. This contrasts
with other work of the authors as well as with the conjectured picture for
knots in lens spaces that admit Dehn surgeries giving the 3-sphere.


title:
Local Geometric Phase and Quantum State Tomography in a Superconducting
  Qubit

abstract:
  We investigate quantum state reconstruction of a superconducting qubit
threaded by an Aharonov-Bohm flux, with particular attention to the local
geometric phase. A state reconstruction scheme is introduced with a proper
account of the local geometric phase generated by Faraday's law of induction.
Our scheme is based on measurement of three complementary quantities, that is,
the extra charge and two local currents. Incorporating time-reversal symmetry
and the Faraday's law, we show that the full density matrix can be
reconstructed without ambiguity in the choice of gauge. This procedure clearly
demonstrates that the quantum Faraday effect plays an essential role in the
dynamics of a quantum system that involves Aharonov-Bohm flux.


title: Symmetries of Codeword Stabilized Quantum Codes

abstract:
  Symmetry is at the heart of coding theory. Codes with symmetry, especially
cyclic codes, play an essential role in both theory and practical applications
of classical error-correcting codes. Here we examine symmetry properties for
codeword stabilized (CWS) quantum codes, which is the most general framework
for constructing quantum error-correcting codes known to date. A CWS code Q can
be represented by a self-dual additive code S and a classical code C, i.,e.,
Q=(S,C), however this representation is in general not unique. We show that for
any CWS code Q with certain permutation symmetry, one can always find a
self-dual additive code S with the same permutation symmetry as Q such that
Q=(S,C). As many good CWS codes have been found by starting from a chosen S,
this ensures that when trying to find CWS codes with certain permutation
symmetry, the choice of S with the same symmetry will suffice. A key step for
this result is a new canonical representation for CWS codes, which is given in
terms of a unique decomposition as union stabilizer codes. For CWS codes, so
far mainly the standard form (G,C) has been considered, where G is a graph
state. We analyze the symmetry of the corresponding graph of G, which in
general cannot possess the same permutation symmetry as Q. We show that it is
indeed the case for the toric code on a square lattice with translational
symmetry, even if its encoding graph can be chosen to be translational
invariant.


title: Dust Formation in the Ejecta of Common Envelope Systems

abstract:
  The material that is ejected in a common-envelope (CE) phase in a close
binary system provides an ideal environment for dust formation. By constructing
a simple toy model to describe the evolution of the density and the temperature
of CE ejecta and using the \emph{AGBDUST} code to model dust formation, we show
that dust can form efficiently in this environment. The actual dust masses
produced in the CE ejecta depend strongly on their temperature and density
evolution. We estimate the total dust masses produced by CE evolution by means
of a population synthesis code and show that, compared to dust production in
AGB stars, the dust produced in CE ejecta may be quite significant and could
even dominate under certain circumstances.


title:
Angle and frequency dependence of self-energy from spin fluctuations
  mediated d-wave pairing for high temperature superconductors

abstract:
  We investigated the characteristics of the spin fluctuations mediated
superconductivity employing the Eliashberg formalism. The effective interaction
between electrons was modeled in terms of the spin susceptibility measured by
the inelastic neutron scattering experiments on single crystal La2-xSrxCuO4
superconductors. The diagonal self-energy and off-diagonal self-energy were
calculated by solving the coupled Eliashberg equation self-consistently for
chosen spin susceptibility and tight-binding dispersion of electrons. The full
momentum and frequency dependence of the self-energy is presented for the
optimal, overdoped, and underdoped LSCO cuprates in superconductive state.
These results may be compared with the experimentally deduced self-energy from
ARPES experiments.


title: Curvaton mechanism after multi-field inflation

abstract:
  The evolution of the curvature perturbation after multi-field inflation is
studied in the light of the curvaton mechanism. Past numerical studies show
that many-field inflation causes significant evolution of the curvature
perturbation after inflation, which generates significant non-Gaussianity at
the same time. We reveal the underlying mechanism of the evolution and show
that the evolution is possible in a typical two-field inflation model.


title:
$Sp_{2n}(F_{q^{2}})$-Invariants In Irreducible Unipotent Representations
  of $Sp_{4n}(F_{q})$

abstract:
  We show that for any irreducible representation of $Sp_{4n}(F_{q})$, the
subspace of all its $Sp_{2n}(F_{q^{2}})$-invariants is at most one-dimensional.
In terms of Lusztig symbols, we give a complete list of irreducible unipotent
representations of $Sp_{4n}(F_{q})$ which have a nonzero
$Sp_{2n}(F_{q^{2}})$-invariant and, in particular, we prove that every
irreducible unipotent cuspidal representation has a one-dimensional subspace of
$Sp_{2n}(F_{q^{2}})$-invariants. As an application, we give an elementary proof
of the fact that the unipotent cuspidal representation is defined over $Q$,
which was proved by Lusztig.