title:
Extinction transition in stochastic population dynamics in a random,
  convective environment

abstract:
  Motivated by modeling the dynamics of a population living in a flowing medium
where the environmental factors are random in space, we have studied an
asymmetric variant of the one-dimensional contact process, where the quenched
random reproduction rates are systematically greater in one direction than in
the opposite one. The spatial disorder turns out to be a relevant perturbation
but, according to results of Monte Carlo simulations, the behavior of the model
at the extinction transition is different from the (infinite randomness)
critical behavior of the disordered, symmetric contact process. Depending on
the strength $a$ of the asymmetry, the critical population drifts either with a
finite velocity or with an asymptotically vanishing velocity as $x(t)\sim
t^{\mu(a)}$, where $\mu(a)<1$. Dynamical quantities are non-self-averaging at
the extinction transition; the survival probability, for instance, shows
multiscaling, i.e. it is characterized by a broad spectrum of effective
exponents. For a sufficiently weak asymmetry, a Griffiths phase appears below
the extinction transition, where the survival probability decays as a
non-universal power of the time while, above the transition, another extended
phase emerges, where the front of the population advances anomalously with a
diffusion exponent continuously varying with the control parameter.


title: Temperature-dependent Phonon Shifts in Monolayer MoS2

abstract:
  We present a combined experimental and computational study of two-dimensional
molybdenum disulfde (MoS2) and the effect of temperature on the frequency
shifts of the Raman-active E2g and A1g modes in the monolayer. While both peaks
show an expected red-shift with increasing temperature, the frequency shift is
larger for the A1g more than for the E2g mode. This is in contrast to
previously reported bulk behavior, in which the E2g mode shows a larger
frequency shift with temperature. The temperature dependence of these phonon
shifts is attributed to the anharmonic contributions to the ionic interaction
potential in the two-dimensional system.


title: Enhanced Bd --> mu+ mu- Decay: What if?

abstract:
  If the very rare $B_d^0 \to \mu^+\mu^-$ decay is enhanced to (3--4) $\times
10^{-10}$ level or higher, it can be discovered with existing 2011-2012 LHC
data. It might then cast some doubt on the Higgs boson nature of the 126 GeV
boson, since the likely explanation would be due to the fourth generation
$t^\prime$ quark. There is a mild motivation from the known tension in
$\sin2\beta/\phi_1$. If discovery is made before the 13 TeV run, then the $b
\to d$ quadrangle (modulo $m_{t'}$) would suddenly fall into our lap. Continued
pursuit in future runs can probe below $3 \times 10^{-10}$.


title:
Power-Conditional-Expected Priors: Using g-priors with Random Imaginary
  Data for Variable Selection

abstract:
  The Zellner's g-prior and its recent hierarchical extensions are the most
popular default prior choices in the Bayesian variable selection context. These
prior set-ups can be expressed power-priors with fixed set of imaginary data.
In this paper, we borrow ideas from the power-expected-posterior (PEP) priors
in order to introduce, under the g-prior approach, an extra hierarchical level
that accounts for the imaginary data uncertainty. For normal regression
variable selection problems, the resulting power-conditional-expected-posterior
(PCEP) prior is a conjugate normal-inverse gamma prior which provides a
consistent variable selection procedure and gives support to more parsimonious
models than the ones supported using the g-prior and the hyper-g prior for
finite samples. Detailed illustrations and comparisons of the variable
selection procedures using the proposed method, the g-prior and the hyper-g
prior are provided using both simulated and real data examples.


title:
A formal introduction to Horndeski and Galileon theories and their
  generalizations

abstract:
  We review different constructions of Galileon theories in both flat and
curved space, and for both single scalar field models as well as multi-field
models. Our main emphasis is on the formal mathematical properties of these
theories and their construction.


title:
Chiral Transition Within Effective Quark Models under Strong Magnetic
  Fields

abstract:
  In the recently years it has been argued that spectators in heavy ion
collisions are responsible for creating a strong magnetic field that could play
an important role in the QCD phase transition. In this work we use the SU(2)
Nambu--Jona-Lasinio (NJL) model in order to study the chiral transition in
quark matter subject to a strong magnetic field. We show some results involving
the breaking of chiral symmetry and its restoration at finite temperature and
density.


title: Beyond the Standard Model of Physics with Astronomical Observations

abstract:
  There has been significant recent progress in observational cosmology. This,
in turn, has provided an unprecedented picture of the early universe and its
evolution. In this review I will present a (biased) view of how one can use
these observational results to constraint fundamental physics and in particular
physics beyond the standard model.


title: Supersymmetry, Nonthermal Dark Matter and Precision Cosmology

abstract:
  Within the Minimal Supersymmetric Standard Model (MSSM), LHC bounds suggest
that scalar superpartner masses are far above the electroweak scale. Given a
high superpartner mass, nonthermal dark matter is a viable alternative to WIMP
dark matter generated via freezeout. In the presence of moduli fields
nonthermal dark matter production is associated with a long matter dominated
phase, modifying the spectral index and primordial tensor amplitude relative to
those in a thermalized primordial universe. Nonthermal dark matter can have a
higher self-interaction cross-section than its thermal counterpart, enhancing
astrophysical bounds on its annihilation signals. We constrain the
contributions to the neutralino mass from the bino, wino and higgsino using
existing astrophysical bounds and direct detection experiments for models with
nonthermal neutralino dark matter. Using these constraints we quantify the
expected change to inflationary observables resulting from the nonthermal
phase.


title: Anomalous Magnetohydrodynamics

abstract:
  Anomalous symmetries induce currents which can be parallel rather than
orthogonal to the hypermagnetic field. Building on the analogy with charged
liquids at high magnetic Reynolds numbers, the persistence of anomalous
currents is scrutinized for parametrically large conductivities when the plasma
approximation is accurate. Different examples in globally neutral systems
suggest that the magnetic configurations minimizing the energy density with the
constraint that the helicity be conserved coincide, in the perfectly conducting
limit, with the ones obtainable in ideal magnetohydrodynamics where the
anomalous currents are neglected. It is argued that this is the rationale for
the ability of extending to anomalous magnetohydrodynamics the hydromagnetic
solutions characterized by finite gyrotropy. The generally covariant aspects of
the problem are addressed with particular attention to conformally flat
geometries which are potentially relevant for the description of the
electroweak plasma prior to the phase transition.


title: The 37-month MAXI/GSC source catalog in the high Galactic-latitude sky

abstract:
  We present the catalog of high Galactic-latitude ($|b|>10^{\circ}$) X-ray
sources detected in the first 37-month data of Monitor of All-sky X-ray Image
(MAXI) / Gas Slit Camera (GSC). To achieve the best sensitivity, we develop a
background model of the GSC that well reproduces the data based on the detailed
on-board calibration. Source detection is performed through image fit with the
Poisson likelihood algorithm. The catalog contains 500 objects detected in the
4--10 keV band with significance of $s_{\rm D, 4-10 keV} \geq 7$. The limiting
sensitivity is $\approx 7.5\times10^{-12}$ ergs cm$^{-2}$ s$^{-1}$ ($\approx
0.6$ mCrab) in the 4--10 keV band for 50% of the survey area, which is the
highest ever achieved as an all-sky survey mission covering this energy band.
We summarize the statistical properties of the catalog and results from cross
matching with the Swift/BAT 70-month catalog, the meta-catalog of X-ray
detected clusters of galaxies, and the MAXI/GSC 7-month catalog. Our catalog
lists the source name (2MAXI), position and its error, detection significances
and fluxes in the 4--10 keV and 3--4 keV bands, their hardness ratio, and basic
information of the likely counterpart available for 296 sources.


title: Correlated-Electron Systems and High Temperature Superconductivity

abstract:
  We present recent theoretical results on superconductivity in
correlated-electron systems, especially in the two-dimensional Hubbard model
and the three-band d-p model. The mechanism of superconductivity in
high-temperature superconductors has been extensively studied on the basis of
various electronic models and also electron-phonon models. In this study we
investigate the properties of superconductivity in correlated-electron systems
by using numerical methods such as the variational Monte Carlo method and the
quantum Monte Carlo method.
  The Hubbard model is one of basic models for strongly correlated electron
systems, and is regarded as the model of cuprate high temperature
superconductors. The d-p model is more realistic model for cuprates. The
superconducting condensation energy obtained by adopting the Gutzwiller ansatz
is in reasonable agreement with the condensation energy estimated for
YBa_2Cu_3O_7. We show the phase diagram of the ground state using this method.
We have further investigated the stability of striped and checkerboard states
in the under-doped region. The relationship of the hole density x and
incommensurability \delta, \delta\sim x, is satisfied in the lower doping
region, as indicated by the variational Monte Carlo calculations. We have
performed a variational Monte Carlo simulation on a two-dimensional t-t'-t"-U
Hubbard model with a Bi-2212 type band structure and found that the 4\times 4
period checkerboard spin modulation, that is characterized by multi Q vectors,
is stabilized.
  We also present a new algorithm of the diagonalization quantum Monte Carlo
method that is a method for the evaluation of expectation values without the
negative sign difficulty. We show that the pair correlation function is not
enhanced at half-filling, and is indeed enhanced with hole doping.


title:
Detection of Outer Rotations on 3D-Vector Fields with Iterative
  Geometric Correlation and its Efficiency

abstract:
  Correlation is a common technique for the detection of shifts. Its
generalization to the multidimensional geometric correlation in Clifford
algebras has been proven a useful tool for color image processing, because it
additionally contains information about a rotational misalignment. But so far
the exact correction of a three-dimensional outer rotation could only be
achieved in certain special cases. In this paper we prove that applying the
geometric correlation iteratively has the potential to detect the outer
rotational misalignment for arbitrary three-dimensional vector fields. We
further present the explicit iterative algorithm, analyze its efficiency
detecting the rotational misalignment in the color space of a color image. The
experiments suggest a method for the acceleration of the algorithm, which is
practically tested with great success.


title:
More basic hypergeometric limits of the elliptic hypergeometric beta
  integral

abstract:
  In this article we continue the work from arXiv:0902.0621. In that article
Eric Rains and the present author considered the limits of the elliptic beta
integral as p->0 while the parameters t_r have a p-dependence of the form
t_r=u_rp^{\alpha_r} (for fixed u_r and certain real numbers \alpha_r). In this
article we again consider such limits, but now we let p->0 along a geometric
sequence p=xq^{sk} (for some integer s, while k -> \infty), and only allow
\alpha_r\in 2/s Z. These choices allow us to take many more limits. In
particular we now also obtain bilateral basic hypergeometric series as possible
limits, such as the evaluation formula for a very well poised {}_6\psi_6.


title: Switching of swimming modes in Magnetospirillium gryphiswaldense

abstract:
  The microaerophilic magnetotactic bacterium Magnetospirillum gryphiswaldense
swims along magnetic field lines using a single flagellum at each cell pole. It
is believed that this magnetotactic behavior enables cells to seek optimal
oxygen concentration with maximal efficiency. We analyse the trajectories of
swimming M. gryphiswaldense cells in external magnetic fields larger than the
earth's field, and show that each cell can switch very rapidly (in < 0.2 s)
between a fast and a slow swimming mode. Close to a glass surface, a variety of
trajectories was observed, from straight swimming that systematically deviates
from field lines to various helices. A model in which fast (slow) swimming is
solely due to the rotation of the trailing (leading) flagellum can account for
these observations. We determined the magnetic moment of this bacterium using a
new method, and obtained a value of (2.0 $\pm$ 0.6) $\times$ $10^{-16}$ Am$^2$.
This value is found to be consistent with parameters emerging from quantitative
fitting of trajectories to our model.


title: COOEE bitumen. Chemical aging

abstract:
  We study chemical aging in "COOEE bitumen" using molecular dynamic
simulations. This model bitumen is composed of four realistic molecule types:
saturated hydrocarbon, resinous oil, resin, and asphaltene. The aging reaction
is modelled by the chemical reaction: "2 resins $\rightarrow$ 1 asphaltene".
Molecular dynamic simulations of four bitumen compositions, obtained by a
repeated application of the aging reaction, are performed. The stress
autocorrelation function, the fluid structure, the rotational dynamics of the
plane aromatic molecules, and the diffusivity of each molecule, are determined
for the four different compositions. The aging reaction causes a significant
dynamics slowdown, which is correlated to the aggregation of asphaltene
molecules in larger and dynamically slower nanoaggregates. Finally, a detailed
description of the role of each molecule types in the aggregation and aging
processes is given.


title:
Inference of chromosomal inversion dynamics from Pool-Seq data in
  natural and laboratory populations of Drosophila melanogaster

abstract:
  Sequencing of pools of individuals (Pool-Seq) represents a reliable and cost-
effective approach for estimating genome-wide SNP and transposable element
insertion frequencies. However, Pool-Seq does not provide direct information on
haplotypes so that for example obtaining inversion frequencies has not been
possible until now. Here, we have developed a new set of diagnostic marker SNPs
for 7 cosmopolitan inversions in Drosophila melanogaster that can be used to
infer inversion frequencies from Pool-Seq data. We applied our novel marker set
to Pool-Seq data from an experimental evolution study and from North American
and Australian latitudinal clines. In the experimental evolution data, we find
evidence that positive selection has driven the frequencies of In(3R)C and
In(3R)Mo to increase over time. In the clinal data, we confirm the existence of
frequency clines for In(2L)t, In(3L)P and In(3R)Payne in both North America and
Australia and detect a previously unknown latitudinal cline for In(3R)Mo in
North America. The inversion markers developed here provide a versatile and
robust tool for characterizing inversion frequencies and their dynamics in
Pool- Seq data from diverse D. melanogaster populations.


title:
Scattering for a massless critical nonlinear wave equation in 2 space
  dimensions

abstract:
  We prove scattering for a massless wave equation which is critical in two
space dimensions. Our method combines conformal inversion with decay estimates
from Struwe's previous work on global existence of a similar equation.


title: Some equations for the universal Kummer variety

abstract:
  We give a method to find quartic Heisenberg invariant equations for Kummer
varieties and we give some explicit examples. From these equations for
g-dimensional Kummer varieties one obtains equations for the moduli space of
g+1-dimensional Kummer varieties. These again define modular forms which vanish
on the period matrices of Riemann surfaces. The modular forms that we find for
g=5 appear to be new and of lower weight than known before.


title:
Top quark pair production at small transverse momentum in hadronic
  collisions

abstract:
  We investigate the transverse momentum resummation for top quark pair
production at hadron colliders using the soft-collinear effective theory and
the heavy-quark effective theory. We derive the factorization formula for
$t\bar{t}$ production at small pair transverse momentum, and show in detail the
procedure for calculating the key ingredient of the factorization formula: the
next-to-leading order soft functions. We compare our numerical results with
experimental data and find that they are consistent within theoretical and
experimental uncertainties. To verify the correctness of our resummation
formula, we expand it to the next-to-leading order and the
next-to-next-to-leading order, and compare those expressions with the exact
fixed-order results numerically. Finally, using the results of transverse
momentum resummation, we discuss the transverse-momentum-dependent
forward-backward asymmetry at the Tevatron.


title:
Contraction or steady state? An analysis of credit risk management in
  Italy in the period 2008-2012

abstract:
  Credit risk management in Italy is characterized, in the period June 2008 to
June 2012, by frequent (frequency=0.5 cycles per year) and intense (peak
amplitude: mean=39.2 billion Euros, s.e.=2.83 billion Euros) quarterly
contractions and expansions around the mean (915.4 billion Euros, s.e.=3.59
billion Euros) of the nominal total credit used by non-financial corporations.
Such frequent and intense fluctuations are frequently ascribed to exogenous
Basel II procyclical effects on credit flow into the economy and, consequently,
Basel III output based point in time Credit to GDP countercyclical buffering
advocated. We have tested the opposite null hypotheses that such variation is
significantly correlated to actual default rates, and that such correlation is
explained by fluctuations of credit supply around a steady state. We have found
that, in the period June 2008 to June 2012 (n=17), linear regression of credit
growth rates on default rates reveals a negative correlation of r=minus 0.6903
with R squared=0.4765, and that credit supply fluctuates steadily around the
default rate with an Internal Steady State Parameter SSP=0.00245 with chi
squared=37.47 (v=16, P<.005). We conclude that fluctuations of the total credit
used by non-financial corporations are exhaustively explained by variation of
the independent variable default rate, and that credit variation fluctuates
around a steady state. We conclude that credit risk management in Italy has
been effective in parameterizing credit supply variation to default rates
within the Basel II operating framework. Basel III prospective countercyclical
point in time output buffers based on filtered Credit to GDP ratios and dynamic
provisioning proposals should take into account this underlying steady state
statistical pattern.


title: Tearing of Free-Standing Graphene

abstract:
  We examine the fracture mechanics of tearing graphene. We present a molecular
dynamics simulation of the propagation of cracks in clamped, free-standing
graphene as a function of the out-of-plane force. The geometry is motivated by
experimental configurations that expose graphene sheets to out-of-plane forces,
such as back-gate voltage. We establish the geometry and basic energetics of
failure, and obtain approximate analytical expressions for critical crack
lengths and forces. We also propose a method to obtain graphene's toughness. We
observe that the cracks' path and the edge structure produced are dependent on
the initial crack length. This work may help avoid the tearing of graphene
sheets and aid the production of samples with specific edge structures.


title: The Irreducible Spine(s) of Undirected Networks

abstract:
  Using closure concepts, we show that within every undirected network, or
graph, there is a unique irreducible subgraph which we call its "spine". The
chordless cycles which comprise this irreducible core effectively characterize
the connectivity structure of the network as a whole. In particular, it is
shown that the center of the network, whether defined by distance or
betweenness centrality, is effectively contained in this spine. By counting the
number of cycles of length 3 <= k <= max_length, we can also create a kind of
signature that can be used to identify the network. Performance is analyzed,
and the concepts we develop are illurstrated by means of a relatively small
running sample network of about 400 nodes.


title: Four-component united-atom model of bitumen

abstract:
  We propose a four-component molecular model of bitumen. The model includes
realistic chemical constituents and introduces a coarse-graining level that
suppresses the highest frequency modes. Molecular dynamics simulations of the
model are being carried out using Graphic-Processor-Units based software in
time spans in order of microseconds, and this enables the study of slow
relaxation processes characterizing bitumen. This paper focuses on the
high-temperature dynamics as expressed through the mean-square displacement,
the stress autocorrelation function, and rotational relaxation. The diffusivity
of the individual molecules changes little as a function of temperature and
reveals distinct dynamical time scales as a result of the different
constituents in the system. Different time scales are also observed for the
rotational relaxation. The stress autocorrelation function features a slow
non-exponential decay for all temperatures studied. From the stress
autocorrelation function, the shear viscosity and shear modulus are evaluated
at the highest temperature, showing a viscous response at frequencies below 100
MHz. The model predictions of viscosity and diffusivities are compared to
experimental data, giving reasonable agreement. The model shows that the
asphaltene, resin and resinous oil tend to form nano-aggregates. The
characteristic dynamical relaxation time of these aggregates is different from
the homogeneously distributed parts of the system, leading to strong dynamical
heterogeneity.


title: Liquid-crystal patterns of rectangular particles in a square nanocavity

abstract:
  Using density-functional theory in the restricted-orientation approximation,
we analyse the liquid-crystal patterns and phase behaviour of a fluid of hard
rectangular particles confined in a two-dimensional square nanocavity of side
length $H$ composed of hard inner walls. Patterning in the cavity is governed
by surface-induced order, capillary and frustration effects, and depends on the
relative values of particle aspect ratio $\kappa\equiv L/\sigma$, with $L$ the
length and $\sigma$ the width of the rectangles ($L\ge\sigma$), and cavity size
$H$. Ordering may be very different from bulk ($H\to\infty$) behaviour when $H$
is a few times the particle length $L$ (nanocavity). Bulk and confinement
properties are obtained for the cases $\kappa=1$, 3 and 6. In the confined
fluid surface-induced frustration leads to four-fold symmetry breaking in all
phases (which become two-fold symmetric). Since no director distorsion can
arise in our model by construction, frustration in the director orientation is
relaxed by the creation of domain walls (where the director changes by
$90^{\circ}$); this configuration is necessary to stabilise periodic phases.
For $\kappa=1$ the crystal becomes stable with commensuration transitions
taking place as $H$ is varied. In the case $\kappa=3$ the commensuration
transitions involve columnar phases with different number of columns. Finally,
in the case $\kappa=6$, the high-density region of the phase diagram is
dominated by commensuration transitions between smectic structures; at lower
densities there is a symmetry-breaking isotropic $\to$ nematic transition
exhibiting non-monotonic behaviour with cavity size.


title: Schottky uniformizations of Automorphisms of Riemann surfaces

abstract:
  It is well known that the collection of uniformizations of a closed Riemann
surface $S$ is partially ordered; the lowest ones are the Schottky
unformizations, that is, tuples $(\Omega,\Gamma,P:\Omega \to S)$, where
$\Gamma$ is a Schottky group with region of discontinuity $\Omega$ and
$P:\Omega \to S$ is a regular holomorphic cover map with $\Gamma$ as its deck
group.
  Let $\tau:S \to S$ be a conformal (respectively, anticonformal) automorphism
of $S$ of finite order $n$, and let $(\Omega,\Gamma,P:\Omega \to S)$ be a
Schottky uniformization of $S$. Assume that $\tau$ lifts with respect to the
previous Schottky uniformization, that is, there exists a M\"obius
(respectively, extended M\"obius) transformation $\kappa$, keeping $\Omega$
invariant, with $P \circ \kappa=\tau \circ P$. The Kleinian (respectively,
extended Kleinian) group $K=< \Gamma, \kappa >$ contains $\Gamma$ as a finite
index normal subgroup and $K/\Gamma \cong {\mathbb Z}_{n}$. We provide a
structural picture of $K$ in terms of the Klein-Maskit's combination theorems
and some basic groups. Some consequences are (i) the determination of the
number of topologically different types of such groups (fixed $n$ and the rank
of the Schottky normal subgroup) and (ii) for $n$ prime, the number of normal
Schottky normal subgroups, up to conjugacy, that $K$ has.


title: Energy levels and radiative rates for transitions in Ti VI

abstract:
  We report on calculations of energy levels, radiative rates, oscillator
strengths, and line strengths for transitions among the lowest 253 levels of
the (1s$^2$2s$^2$2p$^6$) 3s$^2$3p$^5$, 3s3p$^6$, 3s$^2$3p$^4$3d, 3s3p$^5$3d,
3s$^2$3p$^33d^2$, 3s$^2$3p$^4$4s, 3s$^2$3p$^4$4p and 3s$^2$3p$^4$4d
configurations of Ti VI. The general-purpose relativistic atomic structure
package ({\sc grasp}) and flexible atomic code ({\sc fac}) are adopted for the
calculations. Radiative rates, oscillator strengths and line strengths are
reported for all electric dipole (E1), magnetic dipole (M1), electric
quadrupole (E2) and magnetic quadrupole (M2) transitions among the 253 levels,
although calculations have been performed for a much larger number of levels.
Comparisons are made with existing available results and the accuracy of the
data is assessed. Additionally, lifetimes for all 253 levels are listed,
although comparisons with other theoretical results are limited to only 88
levels. Our energy levels are estimated to be accurate to better than 1%
(within 0.03 Ryd), whereas results for other parameters are probably accurate
to better than 20%. A reassessment of the energy level data on the NIST website
for Ti VI is suggested.


title:
Cosmological evolution of the cosmological plasma with interpartial
  scalar interaction. II. Formulation of mathematical model

abstract:
  On the basis of the relativistic kinetic theory the relativistic statistical
systems with scalar interaction particles are investigated. The self-consistent
system of the equations describing self-gravitating plasma with interpartial
scalar interaction is formulated, macroscopical laws of preservation are
received. The closed system of the equations describing cosmological models to
which the matter is presented by plasma with interpartial scalar interaction is
received.


title: From bounded affine types to automatic timing analysis

abstract:
  Bounded linear types have proved to be useful for automated resource analysis
and control in functional programming languages. In this paper we introduce an
affine bounded linear typing discipline on a general notion of resource which
can be modeled in a semiring. For this type system we provide both a general
type-inference procedure, parameterized by the decision procedure of the
semiring equational theory, and a (coherent) categorical semantics. This is a
very useful type-theoretic and denotational framework for many applications to
resource-sensitive compilation, and it represents a generalization of several
existing type systems. As a non-trivial instance, motivated by our ongoing work
on hardware compilation, we present a complex new application to calculating
and controlling timing of execution in a (recursion-free) higher-order
functional programming language with local store.


title: Finite difference method for a general fractional porous medium equation

abstract:
  We formulate a numerical method to solve the porous medium type equation with
fractional diffusion \[ \frac{\partial u}{\partial t}+(-\Delta)^{\sigma/2}
(u^m)=0 \] posed for $x\in \mathbb{R}^N$, $t>0$, with $m\geq 1$, $\sigma \in
(0,2)$, and nonnegative initial data $u(x,0)$. We prove existence and
uniqueness of the solution of the numerical method and also the convergence to
the theoretical solution of the equation with an order depending on $\sigma$.
We also propose a two points approximation to a $\sigma$-derivative with order
$O(h^{2-\sigma})$.


title: Towards Strong Banach property (T) for SL(3,R)

abstract:
  We prove that SL(3,R) has Strong Banach property (T) in Lafforgue's sense
with respect to the Banach spaces that are $\theta>0$ interpolation spaces (for
the complex interpolation method) between an arbitrary Banach space and a
Banach space with sufficiently good type and cotype. As a consequence, every
action of SL(3,R) or its lattices by affine isometries on such a Banach space X
has a fixed point, and the expanders contructed from SL(3,Z) do not admit a
coarse embedding into X. We also prove a quantitative decay of matrix
coefficients (Howe-Moore property) for representations with small exponential
growth of SL(3,R) on X.
  This class of Banach spaces contains many superreflexive spaces and some
nonreflexive spaces as well. We see no obstruction for this class to be equal
to all spaces with nontrivial type.


title: Precision measurement of the Lambda_b baryon lifetime

abstract:
  The ratio of the \Lambda b baryon lifetime to that of the B0 meson is
measured using 1.0/fb of integrated luminosity in 7 TeV center-of-mass energy
pp collisions at the LHC. The \Lambda b baryon is observed for the first time
in the decay mode \Lambda b -> J/\psi pK-, while the B0 meson decay used is the
well known B0 -> J/\psi pi+K- mode, where the pi+ K- mass is consistent with
that of the K*0(892) meson. The ratio of lifetimes is measured to be 0.976 +/-
0.012 +/- 0.006, in agreement with theoretical expectations based on the heavy
quark expansion. Using previous determinations of the B0 meson lifetime, the
\Lambda b lifetime is found to be 1.482 +/- 0.018 +/- 0.012 ps. In both cases
the first uncertainty is statistical and the second systematic.


title:
Bivelocity picture in the nonrelativistic limit of relativistic
  hydrodynamics

abstract:
  We discuss the nonrelativistic limit of the relativistic
Navier-Fourier-Stokes (NFS) theory. The next-to-leading order relativistic
corrections to the NFS theory for the Landau-Lifshitz fluid are obtained. While
the lowest order truncation of the velocity expansion leads to the usual NFS
equations of nonrelativistic fluids, we show that when the next-to-leading
order relativistic corrections are included, the equations can be expressed
concurrently with two different fluid velocities. One of the fluid velocities
is parallel to the conserved charge current (which follows the Eckart
definition) and the other one is parallel to the energy current (which follows
the Landau-Lifshitz definition). We compare this next-to-leading order
relativistic hydrodynamics with bivelocity hydrodynamics, which is one of the
generalizations of the NFS theory and is formulated in such a way to include
the usual mass velocity and also a new velocity, called the volume velocity. We
find that the volume velocity can be identified with the velocity obtained in
the Landau-Lifshitz definition. Then, the structure of bivelocity
hydrodynamics, which is derived using various nontrivial assumptions, is
reproduced in the NFS theory including the next-to-leading order relativistic
corrections.

categories: cond-mat.stat-mech hep-ph nucl-th physics.flu-dyn


title: Resonances for Dirac operators on the half-line

abstract:
  We consider the 1D Dirac operator on the half-line with compactly supported
potentials. We study resonances as the poles of scattering matrix or
equivalently as the zeros of modified Fredholm determinant. We obtain the
following properties of the resonances: 1) asymptotics of counting function, 2)
estimates on the resonances and the forbidden domain.


title: Coupled Optical Resonance Laser Lockin

abstract:
  We have demonstrated simultaneous laser frequency stabilization of a UV and
IR laser, to the same spectroscopic sample, by monitoring only the absorption
of the UV laser. For trapping and cooling Yb$^{+}$ ions, a frequency stabilized
laser is required at 369.95nm to drive the $^{2}S_{1/2}$ $ \rightarrow $ $
^{2}P_{1/2}$ cooling transition. Since the cycle is not closed, a 935.18nm
laser is needed to drive the $^{2}D_{3/2}$ $\rightarrow$ $^{3}D_{[3/2]1/2}$
transition which is followed by rapid decay to the $^{2}S_{1/2}$ state. Our
369nm laser is locked to Yb$^{+}$ ions generated in a hollow cathode discharge
lamp using saturated absorption spectroscopy. Without pumping, the metastable
$^{2}D_{3/2}$ level is only sparsely populated and direct absorption of 935nm
light is difficult to detect. A resonant 369nm laser is able to significantly
populate the $^{2}D_{3/2}$ state due to the coupling between the levels. Fast
re-pumping to the $^{2}S_{1/2}$ state, by 935nm light, can be detected by
observing the change in absorption of the 369nm laser using lock-in detection
of the photodiode signal. In this way simultaneous locking of two optical
frequencies in very different spectral regimes is accomplished. A rate equation
model gives good qualitative agreement with the experimental results. This
technique offers improved laser frequency stabilization compared to lasers
locked individually to the sample and should be readily applicable to similar
ion systems.


title:
Emergence of space and the general dynamic equation of
  Friedmann-Robertson-Walker universe

abstract:
  A novel idea that the cosmic acceleration can be understood from the
perspective that spacetime dynamics is an emergent phenomena was proposed by T.
Padmanabhan. The Friedmann equations of FRW universe can be derived from
different gravity theories with different modifications of Padmanabhan's
proposal. In this paper, a unified formula is proposed, in which those
modifications can be treated as special cases when the formula is applied to
different universe radii. Furthermore, the dynamic equations of FRW universe in
the $ f(R) $ theory and deformed Ho{\v{r}}ava-Lifshitz theory are investigated.
The results show the validity of our proposed formula.


title: The density of twins of $k$-free numbers

abstract:
  For $k \geq 2$, we consider the number $A_k(Z)$ of positive integers $n \leq
Z$ such that both $n$ and $n+1$ are $k$-free. We prove an asymptotic formula
$A_k(Z) = c_k Z + O(Z^{14/(9k)+\epsilon})$, where the error term improves upon
previously known estimates. The main tool used is the approximative determinant
method of Heath-Brown.


title:
Linear Convergence Rate of a Class of Distributed Augmented Lagrangian
  Algorithms

abstract:
  We study distributed optimization where nodes cooperatively minimize the sum
of their individual, locally known, convex costs $f_i(x)$'s, $x \in {\mathbb
R}^d$ is global. Distributed augmented Lagrangian (AL) methods have good
empirical performance on several signal processing and learning applications,
but there is limited understanding of their convergence rates and how it
depends on the underlying network. This paper establishes globally linear
(geometric) convergence rates of a class of deterministic and randomized
distributed AL methods, when the $f_i$'s are twice continuously differentiable
and have a bounded Hessian. We give explicit dependence of the convergence
rates on the underlying network parameters. Simulations illustrate our
analytical findings.


title: Iterative Byzantine Vector Consensus in Incomplete Graphs

abstract:
  This work addresses Byzantine vector consensus (BVC), wherein the input at
each process is a d-dimensional vector of reals, and each process is expected
to decide on a decision vector that is in the convex hull of the input vectors
at the fault-free processes [3, 8]. The input vector at each process may also
be viewed as a point in the d-dimensional Euclidean space R^d, where d > 0 is a
finite integer. Recent work [3, 8] has addressed Byzantine vector consensus in
systems that can be modeled by a complete graph. This paper considers Byzantine
vector consensus in incomplete graphs. In particular, we address a particular
class of iterative algorithms in incomplete graphs, and prove a necessary
condition, and a sufficient condition, for the graphs to be able to solve the
vector consensus problem iteratively. We present an iterative Byzantine vector
consensus algorithm, and prove it correct under the sufficient condition. The
necessary condition presented in this paper for vector consensus does not match
with the sufficient condition for d > 1; thus, a weaker condition may
potentially suffice for Byzantine vector consensus.


title:
Coupled Mesoscale-Large-Eddy Modeling of Realistic Stable Boundary Layer
  Turbulence

abstract:
  Site-specific flow and turbulence information are needed for various
practical applications, ranging from aerodynamic/aeroelastic modeling for wind
turbine design to optical diffraction calculations. Even though highly
desirable, collecting on-site meteorological measurements can be an expensive,
time-consuming, and sometimes a challenging task. In this work, we propose a
coupled mesoscale-large-eddy modeling framework to synthetically generate
site-specific flow and turbulence data. The workhorses behind our framework are
a state-of-the-art, open-source atmospheric model called the Weather Research
and Forecasting (WRF) model and a tuning-free large-eddy simulation (LES)
model.
  Using this coupled framework, we simulate a nighttime stable boundary layer
(SBL) case from the well-known CASES-99 field campaign. One of the unique
aspects of this work is the usage of a diverse range of observations for
characterization and validation. The coupled models reproduce certain
characteristics of observed low-level jets. They also capture various scaling
regimes of energy spectra, including the so-called spectral gap. However, the
coupled models are unable to capture the intermittent nature of the observed
surface fluxes. Lastly, we document and discuss: (i) the tremendous
spatio-temporal variabilities of observed and modeled SBL flow fields, and (ii)
the significant disagreements among different observational platforms. Based on
these results, we strongly recommend that future SBL modeling studies consider
rigorous validation exercises based on multi-sensor/multi-platform datasets.
  In summary, we believe that the numerical generation of realistic SBL is not
an impossible task. Without any doubt, there remain several computational and
fundamental challenges. The present work should be viewed as a first step to
confront some of these challenges.


title:
The effect of resonant magnetic perturbations on the divertor heat and
  particle fluxes in MAST

abstract:
  Edge localised modes (ELMs) are a concern for future devices, such as ITER,
due to the large transient heat loads they generate on the divertor surfaces
which could limit the operational time of the device. This paper discusses the
application of resonant magnetic perturbations (RMPs) as a mechanism for ELM
control on MAST. Experiments have been performed using an n=3 toroidal mode
number perturbation and measurements of the strike point splitting performed.
The measurements have been made using both infrared and visible imaging to
measure the heat and particle flux to the divertor. The measured profiles have
shown clear splitting in L-mode which compares well with the predication of the
splitting location from modelling including the effect of screening. The
splitting of the strike point has also been studied as a function of time
during the ELM. The splitting varies during the ELM, being the strongest at the
time of the peak heat flux and becoming more filamentary at the end of the ELM
(200 microseconds after the peak midplane D(alpha) emission). Variation in the
splitting profiles has also been seen, with some ELMs showing clear splitting
and others no splitting. A possible explanation of this effect is proposed, and
supported by modelling, which concerns the relative phase between the RMP field
and the ELM filament location.


title:
Neutron diffraction evidence for kinetic arrest of first-order
  magneto-structural phase transitions in some functional magnetic materials

abstract:
  Neutron diffraction measurements, performed in presence of an external
magnetic field, have been used to show structural evidence for the kinetic
arrest of the first-order phase transition from (i) the high temperature
austenite phase to the low temperature martensite phase in the magnetic shape
memory alloy Ni37Co11Mn42.5Sn9.5, (ii) the higher temperature ferromagnetic
phase to the lower temperature antiferromagnetic phase in the half-doped charge
ordered compound La0.5Ca0.5MnO3 and (iii) the formation of a glass-like
arrested state (GLAS). The CHUF (cooling and heating under unequal fields)
protocol has been used to establish phase coexistence of metastable and
equilibrium states of GLAS and also to demonstrate the devitrification of the
arrested metastable states in the neutron diffraction patterns. We also explore
the field-temperature (H,T) phase diagram for the two compounds, which depicts
the kinetic arrest line TK(H). TK is seen to increase as H increases.


title: Statistics for Searches at the LHC

abstract:
  These lectures describe several topics in statistical data analysis as used
in High Energy Physics. They focus on areas most relevant to analyses at the
LHC that search for new physical phenomena, including statistical tests for
discovery and exclusion limits. Particular attention is payed to the treatment
of systematic uncertainties through nuisance parameters.


title:
A near-infrared interferometric survey of debris disc stars. III. First
  statistics based on 42 stars observed with CHARA/FLUOR

abstract:
  (Abridged) Dust is expected to be ubiquitous in extrasolar planetary systems
owing to the dynamical activity of minor bodies. Inner dust populations are,
however, still poorly known because of the high contrast and small angular
separation with respect to their host star. We aim to determine the level of
near-infrared exozodiacal dust emission around a sample of 42 nearby main
sequence stars with spectral types ranging from A to K and to investigate its
correlation with various stellar parameters and with the presence of cold dust
belts. We use high-precision K-band visibilities obtained with the FLUOR
interferometer on the shortest baseline of the CHARA array. The calibrated
visibilities are compared with the expected visibility of the stellar
photosphere to assess whether there is an additional, fully resolved
circumstellar emission. Near-infrared circumstellar emission amounting to about
1% of the stellar flux is detected around 13 of our 42 target stars. Follow-up
observations showed that one of them (eps Cep) is associated with a stellar
companion, while another one was detected around what turned out to be a giant
star (kap CrB). The remaining 11 excesses found around single main sequence
stars are most probably associated with hot circumstellar dust, yielding an
overall occurrence rate of 28+8-6% for our (biased) sample. We show that the
occurrence rate of bright exozodiacal discs correlates with spectral type,
K-band excesses being more frequent around A-type stars. It also correlates
with the presence of detectable far-infrared excess emission in the case of
solar-type stars. This study provides new insight into the phenomenon of bright
exozodiacal discs, showing that hot dust populations are probably linked to
outer dust reservoirs in the case of solar-type stars. For A-type stars, no
clear conclusion can be made regarding the origin of the detected near-infrared
excesses.


title:
Correlations between electrical and mechanical signals during granular
  stick-slip events

abstract:
  Powders and grains exhibit unpredictable jamming-to-flow transitions that
manifest themselves on geophysical scales in catastrophic slip events such as
landslides and earthquakes, and on laboratory/industrial scales in profound
processing difficulties. Over the past few years, insight into these
transitions has been provided by new evidence that slip events may accompanied,
or even preceded, by electrical effects. In the present work, we quantify the
correlation between slip and the separation of electrical charges, using an
archetypal granular material: photoelastic polymers. We measure a strong
correlation between material displacement, acoustic emissions, and voltage. We
find that the generation of voltage is associated with surface, rather than
bulk properties of the granular materials. While voltage precursors are only
occasionally observed in this system, there is some asymmetry in the
cross-correlation between the slip and voltage signals that indicates
differences between the pre-slip and post-slip dynamics.


title:
On the typical rank of real polynomials (or symmetric tensors) with a
  fixed border rank

abstract:
  Let $\sigma_b(X_{m,d}(\mathbb {C}))(\mathbb {R})$, $b(m+1) < \binom{m+d}{m}$,
denote the set of all degree $d$ real homogeneous polynomials in $m+1$
variables (i.e. real symmetric tensors of format $(m+1)\times ... \times
(m+1)$, $d$ times) which have border rank $b$ over $\mathbb {C}$. It has a
partition into manifolds of real dimension $\le b(m+1)-1$ in which the real
rank is constant. A typical rank of $\sigma_b(X_{m,d}(\mathbb {C}))(\mathbb
{R})$ is a rank associated to an open part of dimension $b(m+1)-1$. Here we
classify all typical ranks when $b\le 7$ and $d, m$ are not too small. For a
larger sets of $(m,d,b)$ we prove that $b$ and $b+d-2$ are the two first
typical ranks. In the case $m=1$ (real bivariate polynomials) we prove that $d$
(the maximal possible a priori value of the real rank) is a typical rank for
every $b$.


title: From Raviart-Thomas to HDG

abstract:
  This document has been motivated by a course entitled {\em From
Raviart-Thomas to HDG}, prepared for {\em C\'adiz Num\'erica 2013 -- Course and
Encounter on Numerical Analysis} (C\'adiz, Spain -- June 2013). It is an
introduction to the techniques for local analysis of classical mixed methods
for diffusion problems and how they motivate the Hybridizable Discontinuous
Galerkin method.


title:
Daily, multiwavelength Swift monitoring of the neutron star low-mass
  X-ray binary Cen X-4: evidence for accretion and reprocessing during
  quiescence

abstract:
  We conducted the first long-term (60 days), multiwavelength (optical,
ultraviolet, and X-ray) simultaneous monitoring of Cen X-4 with daily Swift
observations from June to August 2012, with the goal of understanding
variability in the low mass X-ray binary Cen X-4 during quiescence. We found
Cen X-4 to be highly variable in all energy bands on timescales from days to
months, with the strongest quiescent variability a factor of 22 drop in the
X-ray count rate in only 4 days. The X-ray, UV and optical (V band) emission
are correlated on timescales down to less than 110 s. The shape of the
correlation is a power law with index gamma about 0.2-0.6. The X-ray spectrum
is well fitted by a hydrogen NS atmosphere (kT=59-80 eV) and a power law (with
spectral index Gamma=1.4-2.0), with the spectral shape remaining constant as
the flux varies. Both components vary in tandem, with each responsible for
about 50% of the total X-ray flux, implying that they are physically linked. We
conclude that the X-rays are likely generated by matter accreting down to the
NS surface. Moreover, based on the short timescale of the correlation, we also
unambiguously demonstrate that the UV emission can not be due to either thermal
emission from the stream impact point, or a standard optically thick,
geometrically thin disc. The spectral energy distribution shows a small UV
emitting region, too hot to arise from the accretion disk, that we identified
as a hot spot on the companion star. Therefore, the UV emission is most likely
produced by reprocessing from the companion star, indeed the vertical size of
the disc is small and can only reprocess a marginal fraction of the X-ray
emission. We also found the accretion disc in quiescence to likely be UV faint,
with a minimal contribution to the whole UV flux.


title: On model-independent pricing/hedging using shortfall risk and quantiles

abstract:
  We consider the pricing and hedging of exotic options in a model-independent
set-up using \emph{shortfall risk and quantiles}. We assume that the marginal
distributions at certain times are given. This is tantamount to calibrating the
model to call options with discrete set of maturities but a continuum of
strikes. In the case of pricing with shortfall risk, we prove that the minimum
initial amount is equal to the super-hedging price plus the inverse of the
utility at the given shortfall level. In the second result, we show that the
quantile hedging problem is equivalent to super-hedging problems for knockout
options. These results generalize the duality results of [5,6] to the model
independent setting of [1].


title:
Kac-Ward operators, Kasteleyn operators, and s-holomorphicity on
  arbitrary surface graphs

abstract:
  The conformal invariance and universality results of Chelkak-Smirnov on the
two-dimensional Ising model hold for isoradial planar graphs with critical
weights. Motivated by the problem of extending these results to a wider class
of graphs, we define a generalized notion of s-holomorphicity for functions on
arbitrary weighted surface graphs. We then give three criteria for
s-holomorphicity involving the Kac-Ward, Kasteleyn, and discrete Dirac
operators, respectively. Also, we show that some crucial results known to hold
in the planar isoradial case extend to this general setting: in particular,
spin-Ising fermionic observables are s-holomorphic, and it is possible to
define a discrete version of the integral of the square of an s-holomorphic
function. Along the way, we obtain a duality result for Kac-Ward determinants
on arbitrary weighted surface graphs.


title:
From Coulomb blockade to nonlinear quantum dynamics in a superconducting
  circuit with a resonator

abstract:
  Motivated by recent experiments on superconducting circuits consisting of a
dc-voltage biased Josephson junction in series with a resonator, quantum
properties of these devices far from equilibrium are studied. This includes a
crossover from a domain of incoherent to a domain of coherent Cooper pair
tunneling, where the circuit realizes a driven nonlinear oscillator.
Equivalently, weak photon-charge coupling turns into strong correlations
captured by a single degree of freedom. Radiated photons offer a new tool to
monitor charge flow and current noise gives access to nonlinear dynamics, which
allows to analyze quantum-classical boundaries.


title:
Temperature dependence of the switching field distributions in
  all-perpendicular spin-valve nanopillars

abstract:
  We present temperature dependent switching measurements of the Co/Ni
multilayered free element of 75 nm diameter spin-valve nanopillars. Angular
dependent hysteresis measurements as well as switching field measurements taken
at low temperature are in agreement with a model of thermal activation over a
perpendicular anisotropy barrier. However, the statistics of switching (mean
switching field and switching variance) from 20 K up to 400 K are in
disagreement with a N\'{e}el-Brown model that assumes a temperature independent
barrier height and anisotropy field. We introduce a modified N\'{e}el-Brown
model thats fit the experimental data in which we take a $T^{3/2}$ dependence
to the barrier height and the anisotropy field due to the temperature dependent
magnetization and anisotropy energy.


title: Construction of a Holographic Superconductor in F(R) Gravity

abstract:
  We construct a toy model for holographic superconductor with non linear
Maxwell field in the frame of modified gravity. By probe the bulk background by
non linear Maxwell fields we show that superconductivity happens under a
specific critical temperature. The effect of the non linear Maxwell field and
non linear curvature corrections have been studied by analytical matching
methods. We conclude that the non linearity in Maxwell field and curvature
coupling make condensation harder.


title:
Universal quantum fluctuations of a cavity mode driven by a Josephson
  junction

abstract:
  We analyze the quantum dynamics of a superconducting cavity coupled to a
voltage biased Josephson junction. The cavity is strongly excited at resonances
where the voltage energy lost by a Cooper pair traversing the circuit is a
multiple of the cavity photon energy. We find that the resonances are
accompanied by substantial squeezing of the quantum fluctuations of the cavity
over a broad range of parameters and are able to identify regimes where the
fluctuations in the system take on universal values.


title: On the state complexity of semi-quantum finite automata

abstract:
  Some of the most interesting and important results concerning quantum finite
automata are those showing that they can recognize certain languages with
(much) less resources than corresponding classical finite automata
\cite{Amb98,Amb09,AmYa11,Ber05,Fre09,Mer00,Mer01,Mer02,Yak10,ZhgQiu112,Zhg12}.
This paper shows three results of such a type that are stronger in some sense
than other ones because (a) they deal with models of quantum automata with very
little quantumness (so-called semi-quantum one- and two-way automata with one
qubit memory only); (b) differences, even comparing with probabilistic
classical automata, are bigger than expected; (c) a trade-off between the
number of classical and quantum basis states needed is demonstrated in one case
and (d) languages (or the promise problem) used to show main results are very
simple and often explored ones in automata theory or in communication
complexity, with seemingly little structure that could be utilized.


title:
Far-from-equilibrium Sheared Colloidal Liquids: Disentangling
  Relaxation, Advection, and Shear-induced Diffusion

abstract:
  Using high-speed confocal microscopy, we measure the particle positions in a
colloidal suspension under large amplitude oscillatory shear. Using the
particle positions we quantify the in situ anisotropy of the pair-correlation
function -- a measure of the Brownian stress. From these data, we find two
distinct types of responses as the system crosses over from equilibrium to
far-from-equilibrium states. The first is a nonlinear amplitude saturation that
arises from shear-induced advection, while the second is a linear frequency
saturation due to competition between suspension relaxation and shear rate. In
spite of their different underlying mechanisms, we show that all the data can
be scaled onto a master curve that spans the equilibrium and
far-from-equilibrium regimes, linking small amplitude oscillatory to continuous
shear. This observation illustrates a colloidal analog of the Cox-Merz rule and
its microscopic underpinning. Brownian Dynamics simulations show that
interparticle interactions are sufficient for generating both experimentally
observed saturations.


title: Thermodynamic Functions of Magnetized Coulomb Crystals

abstract:
  Free energy, internal energy, and specific heat for each of the three phonon
spectrum branches of a magnetized Coulomb crystal with body-centered cubic
lattice are calculated by numerical integration over the Brillouin zone in the
range of magnetic fields $B$ and temperatures $T$, such that $0 \le \omega_{\rm
B}/\omega_{\rm p}\le 10^3$ and $10^{-4} \le T/T_{\rm p} \le 10^4$. In this
case, $\omega_{\rm B}$ is the ion cyclotron frequency, $\omega_{\rm p}$ and
$T_{\rm p}$ are the ion plasma frequency and plasma temperature, respectively.
The results of numerical calculations are approximated by simple analytical
formulas. For illustration, these formulas are used to analyze the behavior of
the heat capacity in the crust of a neutron star with strong magnetic field.
Thermodynamic functions of magnetized neutron star crust are needed for
modeling various observational phenomena in magnetars and high magnetic field
pulsars.


title: Tailoring exciton dynamics by elastic strain-gradient in semiconductors

abstract:
  As device miniaturization approaches the atomic limit, it becomes highly
desirable to exploit novel paradigms for tailoring electronic structures and
carrier dynamics in materials. Elastic strain can in principle be applied to
achieve reversible and fast control of such properties, but it remains a great
challenge to create and utilize precisely controlled inhomogeneous deformation
in semiconductors. Here, we take a combined experimental and theoretical
approach to demonstrate that elastic strain-gradient can be created
controllably and reversibly in ZnO micro/nanowires. In particular, we show that
the inhomogeneous strain distribution creates an effective field that
fundamentally alters the dynamics of the neutral excitons. As the basic
principles behind these results are quite generic and applicable to most
semiconductors, this work points to a novel route to a wide range of
applications in electronics, optoelectronics, and photochemistry.


title:
Entanglement generation and quantum information transfer between
  spatially-separated qubits in different cavities

abstract:
  The generation and control of quantum states of spatially-separated qubits
distributed in different cavities constitute fundamental tasks in cavity
quantum electrodynamics. An interesting question in this context is how to
prepare entanglement and realize quantum information transfer between qubits
located at different cavities, which are important in large-scale quantum
information processing. In this paper, we consider a physical system consisting
of two cavities and three qubits. Two of the qubits are placed in two different
cavities while the remaining one acts as a coupler, which is used to connect
the two cavities. We propose an approach for generating quantum entanglement
and implementing quantum information transfer between the two
spatially-separated intercavity qubits. The quantum operations involved in this
proposal are performed by a virtual photon process, and thus the cavity decay
is greatly suppressed during the operations. In addition, to complete the
present tasks, only one coupler qubit and one operation step are needed.
Moreover, there is no need of applying classical pulses, so that the
engineering complexity is much reduced and the operation procedure is greatly
simplified. Finally, our numerical results illustrate that high-fidelity
implementation of this proposal using superconducting phase qubits and
one-dimenstion transmision line resonators is feasible for current circuit QED
implementations. This proposal can also be applied to other types of
superconducting qubits, including flux and charge qubits.


title: On minimal support properties of solutions of Schr\"odinger equations

abstract:
  In this paper we obtain minimal support properties of solutions of
Schr\"odinger equations. We improve previously known conditions on the
potential for which the measure of the support of solutions cannot be too
small. We also use these properties to obtain some new results on unique
continuation for the Schr\"odinger operator.


title: Dispersive regime of the Jaynes-Cummings and Rabi lattice

abstract:
  Photon-based strongly-correlated lattice models like the Jaynes-Cummings and
Rabi lattices differ from their more conventional relatives like the
Bose-Hubbard model by the presence of an additional tunable parameter: the
frequency detuning between the pseudo-spin degree of freedom and the harmonic
mode frequency on each site. Whenever this detuning is large compared to
relevant coupling strengths, the system is said to be in the dispersive regime.
The physics of this regime is well-understood at the level of a single
Jaynes-Cummings or Rabi site. Here, we extend the theoretical description of
the dispersive regime to lattices with many sites, for both strong and
ultra-strong coupling. We discuss the nature and spatial range of the resulting
qubit-qubit and photon-photon coupling, demonstrate the emergence of photon-
pairing and squeezing, and illustrate our results by exact diagonalization of
the Rabi dimer.

categories: cond-mat.mes-hall cond-mat.str-el physics.atom-ph quant-ph


title: Landscape construction in non-gradient dynamics: A case from evolution

abstract:
  Adaptive landscape has been a fundamental concept in many branches of modern
biology since Wright's first proposition in 1932. Meanwhile, the general
existence of landscape remains controversial. The causes include the mixed uses
of different landscape definitions with their own different aims and
advantages. Sometimes the difficulty and the impossibility of the landscape
construction for complex models are also equated. To clarify these confusions,
based on a recent formulation of Wright's theory, the current authors construct
generalized adaptive landscape in a two-loci population model with non-gradient
dynamics, where the conventional gradient landscape does not exist. On the
generalized landscape, a population moves along an evolutionary trajectory
which always increases or conserves adaptiveness but does not necessarily
follow the steepest gradient direction. Comparisons of different aspects of
various landscapes lead to a conclusion that the generalized landscape is a
possible direction to continue the exploration of Wright's theory for complex
dynamics.


title: Bilayer Isotropic Thermal Cloak

abstract:
  Invisibility has attracted intensive research in various communities, e.g.,
optics, electromagnetics, acoustics, thermodynamics, etc. However, the most of
them have only been experimentally achieved by virtue of simplified approaches
due to their inhomogeneous and extreme parameters imposed by
transformation-optic method, and usually require challenging realization with
metamaterials. In this paper, we demonstrate an advanced bilayer thermal cloak
with naturally available materials first time. This scheme, directly from
thermal conduction equation, has been validated as an exact cloak rather than a
reduced one, and we experimentally confirmed its perfect performance
(heat-front maintenance and heat protection) in an actual setup. The proposed
scheme may open a new avenue to control the diffusive heat flow in ways
inconceivable with phonons.


title: Basic sequences and spaceability in $\ell_p$ spaces

abstract:
  Let $X$ be a sequence space and denote by $Z(X)$ the subset of $X$ formed by
sequences having only a finite number of zero coordinates. We study algebraic
properties of $Z(X)$ and show (among other results) that (for $p \in
[1,\infty]$) $Z(\ell_p)$ does not contain infinite dimensional closed
subspaces. This solves an open question originally posed by R. M. Aron and V.
I. Gurariy in 2003 on the linear structure of $Z(\ell_\infty)$.
  In addition to this, we also give a thorough analysis of the existing
algebraic structures within the set $X \setminus Z(X)$ and its algebraic
genericity.


title:
Cosmological evolution of the cosmological plasma with interpartial
  scalar interaction. III. Model with the attraction of the like scalar charged
  particles

abstract:
  On the basis of the relativistic kinetic theory the mathematical model of
cosmological plasmas with an attraction of the like charged scalar particles is
formulated. It is shown, that cosmological the model, based on a classical
scalar field with an attraction, is unsatisfactory, that leads to necessity of
attraction of phantom models of a scalar field for systems with an attraction.


title: Non-relativistic quantum theory consistent with principle of locality

abstract:
  Principle of locality means that any local change (perturbation) of the
stationary state wave function field propagates with finite speed, and
therefore reaches distant regions of the field with time delay.
  If a one-particle or multi-particle non-relativistic quantum system is
initially in a stationary state, and its wave function field is locally
perturbed, then perturbed and non-perturbed sub-regions appear in the region.
According to Schr\"odinger equation, borders of the perturbed sub-region
propagate with infinite speed, and the perturbation instantaneously affects all
infinite region. It means that Schr\"odinger equation predicts infinite speed
of the wave function perturbations propagation. This feature of classical
Schr\"odinger equation is traditionally interpreted as non-locality of quantum
mechanics. From physical point of view, such mathematical behavior of
Schr\"odinger equation solutions is questionable because it is difficult to
accept that in real world infinite physical objects can instantaneously appear.
  We introduce a hypothesis that in reality speed of propagation of the
perturbed sub-region borders is equal speed of light. On this basis we develop
and analyze a finite propagation speed concept for non-relativistic quantum
equations. It leads to local interpretation of non-relativistic quantum
mechanics consistent with principle of locality and free of local hidden
variables. The theory is applied to analysis of Einstein-Podolsky-Rosen (EPR)
paradox, entanglement and properties of perturbed matter waves. We proved that
formulated theory agrees with results of classical experiments on electron
matter waves diffraction.


title: A note on the two point function on the boundary of AdS spacetime

abstract:
  We calculate by a new way the two point function on the boundary of AdS
spacetime in 1+2 dimensions for the massless conformal real scalar field. The
result agrees with the answer provided by the Boundary-limit Holography and
Witten recipe. This is done in Poincar\'{e} coordinates. The basic ingredients
of this new method are conformal techniques, quantum fields defined on a half
of Minkowski spacetime and a limit inspired by the Boundary-limit Holography.
We also show that a state in AdS, the global vacuum, in three dimensions
induces a state on the conformal boundary of AdS spacetime, which in turn
induces a state on the BTZ black hole. On the other hand the same state in AdS
induces a state on the BTZ black hole which in turn induces a state on its
conformal boundary. The two ways of getting the state on the conformal boundary
of the BTZ black hole coincide for the massless conformal real scalar field. We
point out that the normalizable modes in the AdS/CFT correspondence for the BTZ
black hole give a similar contribution as the non-normalizable modes used in
the Witten prescription. We also give some clues on why the Witten and the
Boundary-limit Holography prescription coincide.


title:
Reduced density matrix for nonequilibrium steady states: A modified
  Redfield solution approach

abstract:
  We describe a method to obtain the reduced density matrix (RDM) correct up to
second order in system-bath coupling in \emph{nonequilibrium} steady state
situations. The RDM is obtained via a scheme based on analytic continuation,
using the time-local Redfield-like quantum master equation, which was earlier
used by the same authors [J. Chem. Phys. \textbf{136}, 194110 (2012)] to obtain
the correct thermal equilibrium description. This nonequilibrium modified
Redfield solution is then corroborated with the exact RDM obtained via the
nonequilibrium Green's function technique for the quantum harmonic oscillator.
Lastly, the scheme is compared to different quantum master equations (QMEs),
namely the time-local Redfield-like and the Lindblad-like QMEs, in order to
illustrate the differences between each of these approaches.


title: What can the Higgs tell us about UV physics?

abstract:
  After the discovery of a Higgs-like boson with a mass of m~125 GeV at the
LHC, we can now attempt to draw conclusions about physics beyond the Standard
Model. I argue that there are several hints towards new physics at intermediate
scales > 10^8 GeV. I review a class of stringy models with intermediate scale
SUSY which relate the observed Higgs mass to symmetries of the Higgs sector. I
then discuss radiative corrections to m_h, unification, dark matter and the
possibility of classically unstable UV completions in these models.


title: MAXI/GSC Discovery of the Black Hole Candidate MAXI J1305-704

abstract:
  We present the first results on the new black hole candidate, MAXI J1305-704,
observed by MAXI/GSC. The new X-ray transient, named as MAXI J1305-704, was
first detected by the MAXI-GSC all-sky survey on 2012 April 9 in the direction
to the outer Galactic bulge at (l,b)=(304.2deg,-7.6deg). The Swift/XRT
follow-up observation confirmed the uncatalogued point source and localized to
the position at (13h06m56s.44,-70d27'4".91). The source continued the activity
for about five months until 2012 August. The MAXI/GSC light curve in the 2--10
keV band and the variation of the hardness ratio of the 4-10 keV to the 2-4 keV
flux revealed the hard-to-soft state transition on the the sixth day (April 15)
in the brightening phase and the soft-to-hard transition on the ~60th day (June
15) in the decay phase. The luminosity at the initial hard-to-soft transition
was significantly higher than that at the soft-to-hard transition in the decay
phase. The X-ray spectra in the hard state are represented by a single
power-law model with a photon index of ~2.0, while those in the soft state need
such an additional soft component as represented by a multi-color disk
blackbody emission with an inner disk temperature ~0.5--1.2 keV. All the
obtained features support the source identification of a Galactic black-hole
binary located in the Galactic bulge.


title:
On transforms of timelike isothermic surfaces in pseudo-Riemannian space
  forms

abstract:
  The basic theory on the conformal geometry of timelike surfaces in
pseudo-Riemannian space forms is introduced, which is parallel to the classical
framework of Burstall etc. for spacelike surfaces. Then we provide a discussion
on the transforms of timelike $(\pm)-$isothermic surfaces (or real isothermic,
complex isothermic surfaces), including $c-$ polar transforms, Darboux
transforms and spectral transforms. The first main result is that $c-$polar
transforms preserve timelike $(\pm)-$isothermic surfaces, which are
generalizations of the classical Christoffel transforms. The next main result
is that a Darboux pair of timelike isothermic surfaces can also be
characterized as a Lorentzian $O(n-r+1,r+1)/O(n-r,r)\times O(1,1)-$type curved
flat. Finally two permutability theorems of $c-$polar transforms are
established.


title:
A galactic weigh-in: mass models of SINGS galaxies using
  chemospectrophotometric galactic evolution models

abstract:
  The baryonic mass-to-light ratio used to perform the photometry-to-mass
conversion has a tremendous influence on the measurement of the baryonic
content and distribution, as well as on the determination of the dark halo
parameters. Since numerous clues hint at an inside-out formation process for
galaxies, a radius-dependant mass-to-light ratio is needed to physically
represent the radially varying stellar population. In this article, we use
chemo-spectrophotometric galactic evolution (CSPE) models to determine the
mass-to-light ratio for a wide range of masses and sizes in the scenario of an
inside-out formation process by gas accretion. We apply our method on a SINGS
subsample of ten spiral and dwarf galaxies for stellar bands covering from the
UV to the MIR. The CSPE models prove to be a good tool to weight the different
photometric bands in order to obtain consistent stellar discs' masses
regardless of the spectral band used. On the other hand, we show that colour
index vs. the mass-to-light ratio relation is an imperfect tool to assign
masses to young stellar populations because of the degeneracy affecting
mass-to-light ratio in all bands at low colour index. Resulting discs from our
analysis are compatible with the maximum disc hypothesis provided that adequate
bulge/disc decomposition is performed and correction for the presence of a bar
is not neglected since it disturbs the internal disc kinematics. Disc-mass
models including mass-to-light ratio-as a free parameter as well as models
using our physically motivated radial variation of mass-to-light ratio are
presented and discussed for each galaxy.


title:
Hypoellipticity of the di-bar-Neumann problem at a set of infinite type
  with positive CR dimension

abstract:
  This paper presents a class of domains on which the Kohn Laplacian and the
dib-bar-Neumann problem are hypoelliptic but not superlogarithmic and which,
moreover, have a set of points of Levi-degeneracy with positive CR dimension.


title: Searches for New Physics in Multijet Final States

abstract:
  A variety of new physics models predict heavy resonances that decay to
multiple hadronic jets. These models include axigluons, colorons, diquarks,
excited quarks, Randall-Sundrum gravitons, string resonances, and Z' models,
among others. Other models make the prediction that high-pT jets will be
suppressed, resulting in jet extinction. Using the data collected in 2012 at a
center-of-mass energy of 8 TeV, the CMS Collaboration has made a baseline
inclusive jet cross section measurement for comparison with new-physics
searches, and then performed searches for jet extinction and resonances that
decay to two hadronic jets. The results of these searches will be presented. No
evidence of new physics has been observed, and these results set new limits on
the parameters of these models.


title: Configuring the Long-Baseline Neutrino Experiment

abstract:
  We study the neutrino oscillation physics performance of the Long-Baseline
Neutrino Experiment (LBNE) in various configurations. In particular, we compare
the case of a surface detector at the far site augmented by a near detector, to
that with the far site detector placed deep underground but no near detector.
In the latter case, information from atmospheric neutrino events is also
utilized. For values of \theta_{13} favored by reactor experiments and a 100
kt-yr exposure, we find roughly equivalent sensitivities to the neutrino mass
hierarchy, the octant of \theta_{23}, and to CP violation. We also find that as
the exposure is increased, the near detector helps increase the sensitivity to
CP violation substantially more than atmospheric neutrinos.


title: Fault Tolerant Clustering Revisited

abstract:
  In discrete k-center and k-median clustering, we are given a set of points P
in a metric space M, and the task is to output a set C \subseteq ? P, |C| = k,
such that the cost of clustering P using C is as small as possible. For
k-center, the cost is the furthest a point has to travel to its nearest center,
whereas for k-median, the cost is the sum of all point to nearest center
distances. In the fault-tolerant versions of these problems, we are given an
additional parameter 1 ?\leq \ell \leq ? k, such that when computing the cost
of clustering, points are assigned to their \ell-th nearest-neighbor in C,
instead of their nearest neighbor. We provide constant factor approximation
algorithms for these problems that are both conceptually simple and highly
practical from an implementation stand-point.


title: Point Line Cover: The Easy Kernel is Essentially Tight

abstract:
  The input to the NP-hard Point Line Cover problem (PLC) consists of a set $P$
of $n$ points on the plane and a positive integer $k$, and the question is
whether there exists a set of at most $k$ lines which pass through all points
in $P$. A simple polynomial-time reduction reduces any input to one with at
most $k^2$ points. We show that this is essentially tight under standard
assumptions. More precisely, unless the polynomial hierarchy collapses to its
third level, there is no polynomial-time algorithm that reduces every instance
$(P,k)$ of PLC to an equivalent instance with $O(k^{2-\epsilon})$ points, for
any $\epsilon>0$. This answers, in the negative, an open problem posed by
Lokshtanov (PhD Thesis, 2009).
  Our proof uses the machinery for deriving lower bounds on the size of kernels
developed by Dell and van Melkebeek (STOC 2010). It has two main ingredients:
We first show, by reduction from Vertex Cover, that PLC---conditionally---has
no kernel of total size $O(k^{2-\epsilon})$ bits. This does not directly imply
the claimed lower bound on the number of points, since the best known
polynomial-time encoding of a PLC instance with $n$ points requires
$\omega(n^{2})$ bits. To get around this we build on work of Goodman et al.
(STOC 1989) and devise an oracle communication protocol of cost $O(n\log n)$
for PLC; its main building block is a bound of $O(n^{O(n)})$ for the order
types of $n$ points that are not necessarily in general position, and an
explicit algorithm that enumerates all possible order types of n points. This
protocol and the lower bound on total size together yield the stated lower
bound on the number of points.
  While a number of essentially tight polynomial lower bounds on total sizes of
kernels are known, our result is---to the best of our knowledge---the first to
show a nontrivial lower bound for structural/secondary parameters.


title:
A Tight Connection between Gamma-Ray Outbursts and Parsec-Scale Jet
  Activity in the Quasar 3C 454.3

abstract:
  We analyze the multifrequency behavior of the quasar 3C 454.3 during three
prominent \gamma-ray outbursts: 2009 Autumn, 2010 Spring, and 2010 Autumn. The
data reveal a repeating pattern, including a triple flare structure, in the
properties of each \gamma-ray outburst, which implies similar mechanism(s) and
location for all three events. The multi-frequency behavior indicates that the
lower frequency events are co-spatial with the \gamma-ray outbursts, although
the \gamma-ray emission varies on the shortest timescales. We determine that
the variability from UV to IR wavelengths during an outburst results from a
single synchrotron component whose properties do not change significantly over
the different outbursts. Despite a general increase in the degree of optical
linear polarization during an outburst, the polarization drops significantly at
the peak of the \gamma-ray event, which suggests that both shocks and turbulent
processes are involved. We detect two disturbances (knots) with superluminal
apparent speeds in the parsec-scale jet associated with the outbursts in 2009
Autumn and 2010 Autumn. The kinematic properties of the knots can explain the
difference in amplitudes of the \gamma-ray events, while their millimeter-wave
polarization is related to the optical polarization during the outbursts. We
interpret the multi-frequency behavior within models involving either a system
of standing conical shocks or magnetic reconnection events located in the
parsec-scale millimeter-wave core of the jet. We argue that \gamma-ray
outbursts with variability timescales as short as ~ 3 hr can occur on parsec
scales if flares take place in localized regions such as turbulent cells.


title: Ergodic theory for quantum semigroups

abstract:
  Recent results of L. Zsido, based on his previous work with C. P. Niculescu
and A. Stroh, on actions of topological semigroups on von Neumann algebras,
give a Jacobs-de Leeuw-Glicksberg splitting theorem at the von Neumann algebra
(rather than Hilbert space) level. We generalize this to the framework of
actions of quantum semigroups, namely Hopf-von Neumann algebras. To this end,
we introduce and study a notion of almost periodic vectors and operators that
is suitable for our setting.


title:
Preparing Greenberger-Horne-Zeilinger Entangled Photon Fock States of
  Three Cavities Coupled by a Superconducting Flux Qutrit

abstract:
  We propose a way to prepare Greenberger-Horne-Zeilinger (GHZ) entangled
photon Fock states of three cavities, by using a superconducting flux qutrit
coupled to the cavities. This proposal does not require the use of classical
microwave pulses and measurement during the entire operation. Thus, the
operation is greatly simplified and the circuit engineering complexity and cost
is much reduced. The proposal is quite general and can be applied to generate
three-cavity GHZ entangled photon Fock states when the three cavities are
coupled by a different three-level physical system such as a superconducting
charge qutrit, a transmon qutrit, or a quantum dot.


title:
Simultaneous Electrical and Optical Readout of Graphene-Coated High Q
  Silicon Nitride Resonators

abstract:
  We have fabricated and tested mechanical resonators consisting of a
single-atomic-layer of graphene deposited on suspended silicon nitride
membranes. With the addition of the graphene layer we retain the desirable
mechanical properties of silicon nitride but utilize the electrical and optical
properties of graphene to transduce resonant motion by both optical and
electrical means. By positioning the graphene-on-silicon-nitride drums in a
tunable optical cavity we observe position dependent damping and resonant
frequency control of the devices due to optical absorption by graphene.


title: Simple Lie groups without the Approximation Property II

abstract:
  We prove that the universal covering group
$\widetilde{\mathrm{Sp}}(2,\mathbb{R})$ of $\mathrm{Sp}(2,\mathbb{R})$ does not
have the Approximation Property (AP). Together with the fact that
$\mathrm{SL}(3,\mathbb{R})$ does not have the AP, which was proved by Lafforgue
and de la Salle, and the fact that $\mathrm{Sp}(2,\mathbb{R})$ does not have
the AP, which was proved by the authors of this article, this finishes the
description of the AP for connected simple Lie groups. Indeed, it follows that
a connected simple Lie group has the AP if and only if its real rank is zero or
one. By an adaptation of the methods we use to study the AP, we obtain results
on approximation properties for noncommutative $L^p$-spaces associated with
lattices in $\widetilde{\mathrm{Sp}}(2,\mathbb{R})$. Combining this with
earlier results of Lafforgue and de la Salle and results of the second named
author of this article, this gives rise to results on approximation properties
of noncommutative $L^p$-spaces associated with lattices in any connected simple
Lie group.


title: Counting conjugacy classes of cyclic subgroups for fusion systems

abstract:
  We give another proof of an observation of Th\'evenaz \cite{T1989} and
present a fusion system version of it. Namely, for a saturated fusion system
$\CF$ on a finite $p$-group $S$, we show that the number of the $\CF$-conjugacy
classes of cyclic subgroups of $S$ is equal to the rank of certain square
matrices of numbers of orbits, coming from characteristic bisets, the
characteristic idempotent and finite groups realizing the fusion system $\CF$
as in our previous work \cite{P2010}.


title: Fomin-Greene monoids and Pieri operations

abstract:
  We explore monoids generated by operators on certain infinite partial orders.
Our starting point is the work of Fomin and Greene on monoids satisfying the
relations $(\u{r}+\u{r+1})\u{r+1}\u{r}=\u{r+1}\u{r}(\u{r}+\u{r+1})$ and
$\u{r}\u{t}=\u{s}\u{r}$ if $|r-t|>1.$ Given such a monoid, the non-commutative
functions in the variables $\u{}$ are shown to commute. Symmetric functions in
these operators often encode interesting structure constants. Our aim is to
introduce similar results for more general monoids not satisfying the relations
of Fomin and Greene. This paper is an extension of a talk by the second author
at the workshop on algebraic monoids, group embeddings and algebraic
combinatorics at The Fields Institute in 2012.


title: Particle exchange in post-quantum theories

abstract:
  In quantum theory, particles in three spatial dimensions come in two
different types: bosons or fermions, which exhibit sharply contrasting
behaviours due to their different exchange statistics. Could more general forms
of probabilistic theories admit more exotic types of particles? Here, we
propose a thought experiment to identify more exotic particles in general
post-quantum theories. We consider how in quantum theory the phase introduced
by swapping indistinguishable particles can be measured. We generalise this to
post-quantum scenarios whilst imposing indistinguishability and locality
principles. We show that our ability to witness exotic particle exchange
statistics depends on which symmetries are admitted within a theory. These
exotic particles can manifest unusual behaviour, such as non-abelianicity even
in topologically simple three-dimensional space.


title:
Reply to the comment on "Exact Expression for Radiation of an
  Accelerated Charge in Classical Electrodynamics"

abstract:
  Flaws and ambiguities are pointed out upon examining the comment attempting
to solve a problem as raised recently --- the currently accepted formulation of
electromagnetic radiation of an accelerated charge violates the principle of
conservation of energy. This problem is not solved by the comment, due to a
misunderstanding in the meaning of the total radiated power crossing a sphere.
An experiment is suggested to determine whether on not the currently accepted
formulation is valid.


title: Better Approximation Bounds for the Joint Replenishment Problem

abstract:
  The Joint Replenishment Problem (JRP) deals with optimizing shipments of
goods from a supplier to retailers through a shared warehouse. Each shipment
involves transporting goods from the supplier to the warehouse, at a fixed cost
C, followed by a redistribution of these goods from the warehouse to the
retailers that ordered them, where transporting goods to a retailer $\rho$ has
a fixed cost $c_\rho$. In addition, retailers incur waiting costs for each
order. The objective is to minimize the overall cost of satisfying all orders,
namely the sum of all shipping and waiting costs.
  JRP has been well studied in Operations Research and, more recently, in the
area of approximation algorithms. For arbitrary waiting cost functions, the
best known approximation ratio is 1.8. This ratio can be reduced to 1.574 for
the JRP-D model, where there is no cost for waiting but orders have deadlines.
As for hardness results, it is known that the problem is APX-hard and that the
natural linear program for JRP has integrality gap at least 1.245. Both results
hold even for JRP-D. In the online scenario, the best lower and upper bounds on
the competitive ratio are 2.64 and 3, respectively. The lower bound of 2.64
applies even to the restricted version of JRP, denoted JRP-L, where the waiting
cost function is linear.
  We provide several new approximation results for JRP. In the offline case, we
give an algorithm with ratio 1.791, breaking the barrier of 1.8. In the online
case, we show a lower bound of 2.754 on the competitive ratio for JRP-L (and
thus JRP as well), improving the previous bound of 2.64. We also study the
online version of JRP-D, for which we prove that the optimal competitive ratio
is 2.


title: Backward SLE and the symmetry of the welding

abstract:
  The backward chordal Schramm-Loewner Evolution naturally defines a conformal
welding homeomorphism of the real line. We show that this homeomorphism is
invariant under the automorphism $x\mapsto -1/x$, and conclude that the
associated solution to the welding problem (which is a natural renormalized
limit of the finite time Loewner traces) is reversible. The proofs rely on an
analysis of the action of analytic circle diffeomorphisms on the space of
hulls, and on the coupling techniques of the second author.


title: The Initial State of Students Taking an Introductory Physics MOOC

abstract:
  As part of a larger research project into massively open online courses
(MOOCs), we have investigated student background, as well as student
participation in a physics MOOC with a laboratory component. Students completed
a demographic survey and the Force and Motion Conceptual Evaluation at the
beginning of the course. While the course is still actively running, we have
tracked student participation over the first five weeks of the eleven-week
course.


title:
Nuclear matter EOS with light clusters within the mean-field
  approximation

abstract:
  The crust of a neutron star is essentially determined by the low-density
region ($\rho<\rho_0\approx0.15-0.16\unit{fm}^{-3}$) of the equation of state.
At the bottom of the inner crust, where the density is $\rho\lesssim0.1\rho_0$,
the formation of light clusters in nuclear matter will be energetically
favorable at finite temperature. At very low densities and moderate
temperatures, the few body correlations are expected to become important and
light nuclei like deuterons, tritons, helions and $\alpha$-particles will form.
Due to Pauli blocking, these clusters will dissolve at higher densities
$\rho\gtrsim 0.1\rho_0$.
  The presence of these clusters influences the cooling process and quantities,
such as the neutrino emissivity and gravitational waves emission. The
dissolution density of these light clusters, treated as point-like particles,
will be studied within the Relativistic Mean Field approximation. In
particular, the dependence of the dissolution density on the clusters-meson
couplings is studied.


title:
Investigations of the torque anomaly in an annular sector. II. Global
  calculations, electromagnetic case

abstract:
  Recently, it was suggested that there was some sort of breakdown of quantum
field theory in the presence of boundaries, manifesting itself as a torque
anomaly. In particular, Fulling et al. used the finite energy-momentum-stress
tensor in the presence of a perfectly conducting wedge, calculated many years
ago by Deutsch and Candelas, to compute the torque on one of the wedge
boundaries, where the latter was cutoff by integrating the torque density down
to minimum lower radius greater than zero. They observed that that torque is
not equal to the negative derivative of the energy obtained by integrating the
energy density down to the same minimum radius. This motivated a calculation of
the torque and energy in an annular sector obtained by the intersection of the
wedge with two coaxial cylinders. In a previous paper we showed that for the
analogous scalar case, which also exhibited a torque anomaly in the absence of
the cylindrical boundaries, the point-split regulated torque and energy indeed
exhibit an anomaly, unless the point-splitting is along the axis direction. In
any case, because of curvature divergences, no unambiguous finite part can be
extracted. However, that ambiguity is linear in the wedge angle; if the
condition is imposed that the linear term be removed, the resulting torque and
energy is finite, and exhibits no anomaly. In this paper, we demonstrate the
same phenomenon takes place for the electromagnetic field, so there is no
torque anomaly present here either. This is a nontrivial generalization, since
the anomaly found by Fulling et al. is linear for the Dirichlet scalar case,
but nonlinear for the conducting electromagnetic case.


title: Greedy Online Bipartite Matching on Random Graphs

abstract:
  We study the average performance of online greedy matching algorithms on
$G(n,n,p)$, the random bipartite graph with $n$ vertices on each side and edges
occurring independently with probability $p=p(n)$. In the online model,
vertices on one side of the graph are given up front while vertices on the
other side arrive sequentially; when a vertex arrives its edges are revealed
and it must be immediately matched or dropped. We begin by analyzing the
\textsc{oblivious} algorithm, which tries to match each arriving vertex to a
random neighbor, even if the neighbor has already been matched. The algorithm
is shown to have a performance ratio of at least $1-1/e$ for all monotonic
functions $p(n)$, where the performance ratio is defined asymptotically as the
ratio of the expected matching size given by the algorithm to the expected
maximum matching size. Next we show that the conventional \textsc{greedy}
algorithm, which assigns each vertex to a random unmatched neighbor, has a
performance ratio of at least 0.837 for all monotonic functions $p(n)$. Under
the $G(n,n,p)$ model, the performance of \textsc{greedy} is equivalent to the
performance of the well known \textsc{ranking} algorithm, so our results show
that \textsc{ranking} has a performance ratio of at least 0.837. We finally
consider vertex-weighted bipartite matching. Our proofs are based on simple
differential equations that describe the evolution of the matching process.


title: Strong Price of Anarchy and Coalitional Dynamics

abstract:
  We introduce a framework for studying the effect of cooperation on the
quality of outcomes in utility games. Our framework is a coalitional analog of
the smoothness framework of non-cooperative games. Coalitional smoothness
implies bounds on the strong price of anarchy, the loss of quality of
coalitionally stable outcomes, as well as bounds on coalitional versions of
coarse correlated equilibria and sink equilibria, which we define as
out-of-equilibrium myopic behavior as determined by a natural coalitional
version of best-response dynamics.
  Our coalitional smoothness framework captures existing results bounding the
strong price of anarchy of network design games. We show that in any monotone
utility-maximization game, if each player's utility is at least his marginal
contribution to the welfare, then the strong price of anarchy is at most 2.
This captures a broad class of games, including games with a very high price of
anarchy. Additionally, we show that in potential games the strong price of
anarchy is close to the price of stability, the quality of the best Nash
equilibrium.


title: Abstract GSOS Rules and a Modular Treatment of Recursive Definitions

abstract:
  Terminal coalgebras for a functor serve as semantic domains for state-based
systems of various types. For example, behaviors of CCS processes, streams,
infinite trees, formal languages and non-well-founded sets form terminal
coalgebras. We present a uniform account of the semantics of recursive
definitions in terminal coalgebras by combining two ideas: (1) abstract GSOS
rules l specify additional algebraic operations on a terminal coalgebra; (2)
terminal coalgebras are also initial completely iterative algebras (cias). We
also show that an abstract GSOS rule leads to new extended cia structures on
the terminal coalgebra. Then we formalize recursive function definitions
involving given operations specified by l as recursive program schemes for l,
and we prove that unique solutions exist in the extended cias. From our results
it follows that the solutions of recursive (function) definitions in terminal
coalgebras may be used in subsequent recursive definitions which still have
unique solutions. We call this principle modularity. We illustrate our results
by the five concrete terminal coalgebras mentioned above, e.\,g., a finite
stream circuit defines a unique stream function.


title: A fully dynamical simulation of central nuclear collisions

abstract:
  We present a fully dynamical simulation of central nuclear collisions around
mid-rapidity at LHC energies. Unlike previous treatments, we simulate all
phases of the collision, including the equilibration of the system. For the
simulation, we use numerical relativity solutions to AdS/CFT for the
pre-equilibrium stage, viscous hydrodynamics for the plasma equilibrium stage
and kinetic theory for the low density hadronic stage. Our pre-equilibrium
stage provides initial conditions for hydrodynamics, resulting in sizable
radial flow. The resulting light particle spectra reproduce the measurements
from the ALICE experiment at all transverse momenta.


title: Unified products for Leibniz algebras. Applications

abstract:
  Let $\mathfrak{g}$ be a Leibniz algebra and $E$ a vector space containing
$\mathfrak{g}$ as a subspace. All Leibniz algebra structures on $E$ containing
$\mathfrak{g}$ as a subalgebra are explicitly described and classified by two
non-abelian cohomological type objects: ${\mathcal H}{\mathcal
L}^{2}_{\mathfrak{g}} \, (V, \, \mathfrak{g})$ provides the classification up
to an isomorphism that stabilizes $\mathfrak{g}$ and ${\mathcal H}{\mathcal
L}^{2} \, (V, \, \mathfrak{g})$ will classify all such structures from the view
point of the extension problem - here $V$ is a complement of $\mathfrak{g}$ in
$E$. A general product, called the unified product, is introduced as a tool for
our approach. The crossed (resp. bicrossed) products between two Leibniz
algebras are introduced as special cases of the unified product: the first one
is responsible for the extension problem while the bicrossed product is
responsible for the factorization problem. The description and the
classification of all complements of a given extension $\mathfrak{g} \subseteq
\mathfrak{E} $ of Leibniz algebras are given as a converse of the factorization
problem. They are classified by another cohomological object denoted by
${\mathcal H}{\mathcal A}^{2}(\mathfrak{h}, \mathfrak{g} \, | \,
(\triangleright, \triangleleft, \leftharpoonup, \rightharpoonup))$, where
$(\triangleright, \triangleleft, \leftharpoonup, \rightharpoonup)$ is the
canonical matched pair associated to a given complement $\mathfrak{h}$. Several
examples are worked out in details.