title: The hadronic vacuum polarization with twisted boundary conditions

abstract:
  The leading-order hadronic contribution to the muon anomalous magnetic moment
is given by a weighted integral over the subtracted hadronic vacuum
polarization. This integral is dominated by euclidean momenta of order the muon
mass, i.e., momenta not accessible on current lattice volumes with periodic
boundary conditions. Twisted boundary conditions can in principle help in
accessing momenta of any size even in a finite volume, but their use leads to a
modification of the Ward-Takahashi identity that normally guarantees
transversality of the vacuum polarization. As a result, the vacuum polarization
contains a non-transversal, quadratically divergent term, which arises as an
artifact of using twisted boundary conditions in a finite volume. In this
article, we show how to determine and remove this term from the vacuum
polarization.


title:
Heavy flavor puzzle at LHC: a serendipitous interplay of jet suppression
  and fragmentation

abstract:
  Both charged hadrons and D mesons are considered to be excellent probes of
QCD matter created in ultra relativistic heavy ion collisions. Surprisingly,
recent experimental observations at LHC show the same jet suppression for these
two probes, which - contrary to pQCD expectations - may suggest similar energy
losses for light quarks and gluons in QCD medium. We here use our recently
developed energy loss formalism in a finite size dynamical QCD medium to
analyze this phenomenon that we denote as the "heavy flavor puzzle at LHC". We
show that this puzzle is a consequence of an unusual combination of the
suppression and fragmentation patterns, and in fact does not require invoking
the same energy loss for light partons. Furthermore, we show that this
combination leads to a simple relationship between the suppressions of light
hadrons and D mesons and the corresponding bare quark suppressions.
Consequently, a coincidental matching of jet suppression and fragmentation
allows considerably simplifying the interpretation of the corresponding
experimental data.


title:
Simulation of a Microfluidic Gradient Generator using Lattice Boltzmann
  Methods

abstract:
  Microfluidics provides a powerful and versatile technology to accurately
control spatial and temporal conditions for cell culturing and can therefore be
used to study cellular responses to gradients. Here we use Lattice Boltzmann
methods (LBM) to solve both the Navier-Stokes equation (NSE) for the fluid and
the coupled convection-diffusion equation (CDE) for the compounds that form the
diffusion-based gradient. The design of a microfluidic chamber for
diffusion-based gradients must avoid flow through the cell chamber. This can be
achieved by alternately opening the source and the sink channels. The fast
toggling of microfluidic valves requires switching between different boundary
conditions. We demonstrate that the LBM is a powerful method for handling
complex geometries, high Peclet number conditions, discontinuities in the
boundary conditions, and multiphysics coupling.


title: Galactic cosmic ray induced radiation dose on terrestrial exoplanets

abstract:
  This past decade has seen tremendous advancements in the study of extrasolar
planets. Observations are now made with increasing sophistication from both
ground and space-based instruments, and exoplanets are characterized with
increasing precision. There is a class of particularly interesting exoplanets,
falling in the habitable zone, which is defined as the area around a star where
the planet is capable of supporting liquid water on its surface. Theoretical
calculations also suggest that close-in exoplanets are more likely to have
weaker planetary magnetic fields, especially in case of super earths. Such
exoplanets are subjected to a high flux of Galactic Cosmic Rays (GCRs) due to
their weak magnetic moments. GCRs are energetic particles of astrophysical
origin, which strike the planetary atmosphere and produce secondary particles,
including muons, which are highly penetrating. Some of these particles reach
the planetary surface and contribute to the radiation dose. Along with the
magnetic field, another factor governing the radiation dose is the depth of the
planetary atmosphere. The higher the depth of the planetary atmosphere, the
lower the flux of secondary particles will be on the surface. If the secondary
particles are energetic enough, and their flux is sufficiently high, the
radiation from muons can also impact the sub-surface regions, such as in the
case of Mars. If the radiation dose is too high, the chances of sustaining a
long-term biosphere on the planet are very low. We explore the dependence of
the GCR induced radiation dose on the strength of the planetary magnetic field
and its atmospheric depth, finding that the latter is the decisive factor for
the protection of a planetary biosphere.


title:
Acoustic radiation force and torque on an absorbing compressible
  particle in an inviscid fluid

abstract:
  Exact formulas of the acoustic radiation force and torque exerted by an
arbitrary time-harmonic wave on an absorbing compressible particle that is
suspended in an inviscid fluid are presented. It is considered that the
particle diameter is much smaller than the incident wavelength, i.e. the
so-called Rayleigh scattering limit. Moreover, the particle absorption assumed
here is due to the attenuation of compressional waves only. Shear waves inside
and outside the particle are neglected, since the inner and outer viscous
boundary layer of the particle are supposed to be much smaller than the
particle radius. The obtained radiation force formulas are used to establish
the trapping conditions of a particle by a single-beam acoustical tweezer based
on a spherically focused ultrasound beam. In this case, it is shown that the
particle absorption has a pivotal role in single-beam trapping at the
transducer focal region. Furthermore, it is found that only the first-order
Bessel vortex beam can generate the radiation torque on a small particle. In
addition, numerical evaluation of the radiation force and torque exerted on a
benzene and an olive oil droplet suspended in water are presented and
discussed.


title: Gauge/Gravity Duality and the Black Hole Interior

abstract:
  We present a further argument that typical black holes with field theory
duals have firewalls at the horizon. This argument makes no reference to
entanglement between the black hole and any distant system, and so is not
evaded by identifying degrees of freedom inside the black hole with those
outside. We also address the ER=EPR conjecture of Maldacena and Susskind,
arguing that the correlations in generic highly entangled states cannot be
geometrized as a smooth wormhole.


title: Anomalous fluctuation relations

abstract:
  We study Fluctuation Relations (FRs) for dynamics that are anomalous, in the
sense that the diffusive properties strongly deviate from the ones of standard
Brownian motion. We first briefly review the concept of transient work FRs for
stochastic dynamics modeled by the ordinary Langevin equation. We then
introduce three generic types of dynamics generating anomalous diffusion:
L\'evy flights, long-time correlated Gaussian stochastic processes and
time-fractional kinetics. By combining Langevin and kinetic approaches we
calculate the work probability distributions in the simple nonequilibrium
situation of a particle subject to a constant force. This allows us to check
the transient FR for anomalous dynamics. We find a new form of FRs, which is
intimately related to the validity of fluctuation-dissipation relations.
Analogous results are obtained for a particle in a harmonic potential dragged
by a constant force. We argue that these findings are important for
understanding fluctuations in experimentally accessible systems. As an example,
we discuss the anomalous dynamics of biological cell migration both in
equilibrium and in nonequilibrium under chemical gradients.


title: Dimension-free Euler estimates of rough differential equations

abstract:
  We give a dimension-free Euler estimation of solution of rough differential
equations in term of the driving rough path. In the meanwhile, we prove that,
the solution of rough differential equation is close to the exponential of a
Lie series, with a concrete error bound.


title:
Conforming and Non-Conforming Functional A Posteriori Error Estimates
  for Elliptic Boundary Value Problems in Exterior Domains: Theory and
  Numerical Tests

abstract:
  This paper is concerned with the derivation of conforming and non-conforming
functional a posteriori error estimates for elliptic boundary value problems in
exterior domains. These estimates provide computable and guaranteed upper and
lower bounds for the difference between the exact and the approximate solution
of the respective problem. We extend earlier results for conforming
approximations to the non-conforming case, for which the approximate solutions
might not belong to the energy space and are just considered to be square
integrable. Moreover, we present some numerical tests.


title:
Electrostatic Interaction of Heterogeneously Charged Surfaces with
  Semipermeable Membranes

abstract:
  In this paper we study the electrostatic interaction of a heterogeneously
charged wall with a neutral semipermeable membrane. The wall consists of
periodic stripes, where the charge density varies in one direction. The
membrane is in a contact with a bulk reservoir of an electrolyte solution and
separated from the wall by a thin film of salt-free liquid. One type of ions
(small counterions) permeates into the gap and gives rise to a
distance-dependent membrane potential, which translates into a repulsive
electrostatic disjoining pressure due to an overlap of counterion clouds in the
gap. To quantify it we use two complementary approaches. First, we propose a
mean-field theory based on a linearized Poisson-Boltzmann equation and Fourier
analysis. These calculations allow us to estimate the effect of a heterogeneous
charge pattern at the wall on the induced heterogeneous membrane potential, and
the value of the disjoining pressure as a function of the gap. Second, we
perform Langevin dynamics simulations of the same system with explicit ions.
The results of the two approaches are in good agreement with each other at low
surface charge and small gap, but differ due to nonlinearity at the higher
charge. These results demonstrate that a heterogeneity of the wall charge can
lead to a huge reduction in the electrostatic repulsion, which could
dramatically facilitate a self-assembly in complex synthetic and biological
systems.


title:
Covariant basis induced by parity for the $(j,0)\oplus (0,j)$
  representation

abstract:
  In this work, we build a covariant basis for operators acting on the
$(j,0)\oplus(0,j)$ Lorentz group representations. The construction is based on
an analysis of the covariant properties of the parity operator, which for these
representations transforms as the completely temporal component of a
symmetrical tensor of rank $2j$. The covariant properties of parity involve the
Jordan algebra of anti commutators of the Lorentz group generators which unlike
the Lie algebra is not universal. We make the construction explicit for
$j=1/2,1$ and $3/2$, reproducing well-known results for the $j=1/2$ case. We
provide an algorithm for the corresponding calculations for arbitrary $j$. This
covariant basis provides an inventory of all the possible interaction terms for
gauge and non-gauge theories of fields for these representations. In
particular, it supplies a single second rank antisymmetric structure, which in
the Poincar\'e projector formalism implies a single Pauli term arising from
gauge interactions and a single (free) parameter $g$, the gyromagnetic factor.
This simple structure predicts that for an elementary particle in this
formalism all multipole moments, $Q^{l}_{E}$ and $Q^{l}_{M}$, are dictated by
the complete algebraic structure of the Lorentz generators and the value of
$g$. We explicitly calculate the multipole moments, for arbitrary $j$ up to
$l=8$. Comparing with results in the literature we find that only the electric
charge and magnetic moment of a spin $j$ particle are independent of the
Lorentz representation under which it transforms, all higher multipoles being
representation dependent. Finally we show that the propagation of the
corresponding spin $j$ waves in a electromagnetic background is causal.


title: Regularity questions for complex Hadamard matrices

abstract:
  We study the partial Hadamard matrices $H\in M_{M\times N}(\mathbb C)$ which
are regular, in the sense that the scalar products between pairs of distinct
rows decompose as sums of cycles (rotated sums of roots of unity). The simplest
non-trivial case is M=3, and we obtain here several results, notably with a
classification at N=7. We discuss as well the potential applications of the M=3
results to various $M=N$ questions.


title:
Theoretical direct WIMP detection rates for transitions to excited
  states

abstract:
  The recent WMAP and Planck data have confirmed that exotic dark matter
together with the vacuum energy (cosmological constant) dominate in the flat
Universe. Many extensions of the standard model provide dark matter candidates,
in particular Weakly Interacting Massive Particles (WIMPs). %Supersymmetry
provides a natural dark matter candidate, the lightest supersymmetric particle
(LSP).
  Thus the direct dark matter detection is central to particle physics and
cosmology. Most of the research on this issue has hitherto focused on the
detection of the recoiling nucleus. In this paper we study transitions to the
excited states, possible in some nuclei, which have sufficiently low lying
excited states. Good examples are the first excited states of I-127 and Xe-129.
%focusing on the first excited state at 50 keV of Iodine A=127. We find
appreciable branching ratios for the inelastic scattering mediated by the spin
cross sections. %find that the transition rate to this excited state is about 5
%percent of the transition to the ground state for low mass WIMPS, but the
branching ratio can be much larger in the case pf heaver WIMPS. So, in
principle, the extra signature of the gamma ray following the de-excitation of
these states can, in principle, be exploited experimentally.


title:
Explaining the fine hierarchy in pion and kaon suppression at LHC:
  Importance of fragmentation functions

abstract:
  We here concentrate on available $\pi^\pm$ and $K^\pm$ ALICE preliminary
$R_{AA}$ data in central 2.76 TeV Pb+Pb collisions at LHC. These data show an
interesting fine resolution hierarchy, i.e. the measured $K^\pm$ data have
consistently lower suppression compared to $\pi^\pm$ measurements. We here ask
whether theoretical predictions based on energy loss in dynamical QCD medium
can quantitatively and qualitatively explain such fine resolution. While our
suppression calculations agree well with the data, we find that qualitatively
explaining the fine hierarchy critically depends on the choice of fragmentation
functions. While the most widely used fragmentation functions lead to the
reversal of the observed hierarchy, a more recent version correctly reproduce
the experimental data. We here point to the reasons behind such discrepancy in
the predictions. Our results argue that accuracy of the theoretical predictions
reached a point where comparison with fine resolution data at LHC can generate
useful understanding.


title:
Large-aperture wide-bandwidth antireflection-coated silicon lenses for
  millimeter wavelengths

abstract:
  The increasing scale of cryogenic detector arrays for sub-millimeter and
millimeter wavelength astrophysics has led to the need for large aperture, high
index of refraction, low loss, cryogenic refracting optics. Silicon with n =
3.4, low loss, and relatively high thermal conductivity is a nearly optimal
material for these purposes, but requires an antireflection (AR) coating with
broad bandwidth, low loss, low reflectance, and a matched coefficient of
thermal expansion. We present an AR coating for curved silicon optics comprised
of subwavelength features cut into the lens surface with a custom three axis
silicon dicing saw. These features constitute a metamaterial that behaves as a
simple dielectric coating. We have fabricated and coated silicon lenses as
large as 33.4 cm in diameter with coatings optimized for use between 125-165
GHz. Our design reduces average reflections to a few tenths of a percent for
angles of incidence up to 30 degrees with low cross-polarization. We describe
the design, tolerance, manufacture, and measurements of these coatings and
present measurements of the optical properties of silicon at millimeter
wavelengths at cryogenic and room temperatures. This coating and lens
fabrication approach is applicable from centimeter to sub-millimeter
wavelengths and can be used to fabricate coatings with greater than octave
bandwidth.


title: Cloud Template, a Big Data Solution

abstract:
  Today cloud computing has become as a new concept for hosting and delivering
different services over the Internet for big data solutions. Cloud computing is
attractive to different business owners of both small and enterprise as it
eliminates the requirement for users to plan ahead for provisioning, and allows
enterprises to start from the small and increase resources only when there is a
rise in service demand. Despite the fact that cloud computing offers huge
opportunities to the IT industry, the development of cloud computing technology
is currently has several issues. This study presents an idea for introducing
cloud templates which will be used for analyzing, designing, developing and
implementing cloud computing systems. We will present a template based design
for cloud computing systems, highlighting its key concepts, architectural
principles and state of the art implementation, as well as research challenges
and future work requirements. The aim of this idea is to provide a better
understanding of the design challenges of cloud computing and identify
important research directions in this big data increasingly important area. We
will describe a series of studies by which we and other researchers have
assessed the effectiveness of these techniques in practical situations.
Finally, in this study we will show how this idea could be implemented in a
practical and useful way in industry.


title:
Content Based Image Retrieval System using Feature Classification with
  Modified KNN Algorithm

abstract:
  Feature means countenance, remote sensing scene objects with similar
characteristics, associated to interesting scene elements in the image
formation process. They are classified into three types in image processing,
that is low, middle and high. Low level features are color, texture and middle
level feature is shape and high level feature is semantic gap of objects. An
image retrieval system is a computer system for browsing, searching and
retrieving images from a large image database. Content Based Image Retrieval is
a technique which uses visual features of image such as color, shape, texture
to search user required image from large image database according to user
requests in the form of a query. MKNN is an enhancing method of KNN. The
proposed KNN classification is called MKNN. MKNN contains two parts for
processing, they are validity of the train samples and applying weighted KNN.
The validity of each point is computed according to its neighbors. In our
proposal, Modified K-Nearest Neighbor can be considered a kind of weighted KNN
so that the query label is approximated by weighting the neighbors of the
query.


title: Gibbs States on Random Configurations

abstract:
  We study a class of Gibbs measures of classical particle spin systems with
spin space $S=\mathbb{R}^{m}$ and unbounded pair interaction, living on a
metric graph given by a typical realization $\gamma $ of a random point process
in $\mathbb{R}^{n}$. Under certain conditions of growth of pair- and
self-interaction potentials, we prove that the set $\mathcal{G}(S^{\gamma})$ of
all such Gibbs measures is not empty for almost all $\gamma $, and study
support properties of $\nu_{\gamma}\in \mathcal{G}(S^{\gamma})$. Moreover we
show the existence of measurable maps (selections) $\gamma \mapsto
\nu_{\gamma}$ and derive the corresponding averaged moment estimates.


title:
Characterization of Potential U.S. Sites for the Cherenkov Telescope
  Array

abstract:
  The Cherenkov Telescope Array (CTA) is a major ground-based observatory
proposed for gamma-ray astronomy. CTA is envisioned to consist of two large
arrays of atmospheric Cherenkov telescopes for the study of sources of
high-energy gamma rays in the energy range of a few tens of GeV to beyond 100
TeV. One array would be located in the southern hemisphere and one in the
northern hemisphere. After a detailed search, we have identified two potential
sites in the USA for the northern array. Both sites are located in northern
Arizona. Here we describe the two sites and the deployment of instrumentation
to characterize them. The characteristics of the sites, in terms of their
atmospheric and climatic properties, are described. We show recent data from
the automated monitoring equipment at the sites and compare these data to a
commercial simulation. Details regarding the facilities and infrastructure
required for the sites are also presented.


title: Results on neutrinoless double beta decay of 76Ge from GERDA Phase I

abstract:
  Neutrinoless double beta decay is a process that violates lepton number
conservation. It is predicted to occur in extensions of the Standard Model of
particle physics. This Letter reports the results from Phase I of the GERmanium
Detector Array (GERDA) experiment at the Gran Sasso Laboratory (Italy)
searching for neutrinoless double beta decay of the isotope 76Ge. Data
considered in the present analysis have been collected between November 2011
and May 2013 with a total exposure of 21.6 kgyr. A blind analysis is performed.
The background index is about 1.10^{-2} cts/(keV kg yr) after pulse shape
discrimination. No signal is observed and a lower limit is derived for the
half-life of neutrinoless double beta decay of 76Ge, T_1/2 > 2.1 10^{25} yr
(90% C.L.). The combination with the results from the previous experiments with
76Ge yields T_1/2 > 3.0 10^{25} yr (90% C.L.).


title:
Sharp global regularity for the 2+1-dimensional equivariant Faddeev
  model

abstract:
  The aim of this article is to prove that for the 2+1-dimensional equivariant
Faddeev model, which is a quasilinear generalization of the corresponding
nonlinear sigma model, small initial data in critical Besov spaces evolve into
global solutions which scatter.


title:
On the strong metric dimension of Cartesian and direct products of
  graphs

abstract:
  Let $G$ be a connected graph. A vertex $w$ {\em strongly resolves} a pair $u,
v$ of vertices of $G$ if there exists some shortest $u-w$ path containing $v$
or some shortest $v-w$ path containing $u$. A set $W$ of vertices is a {\em
strong resolving set} for $G$ if every pair of vertices of $G$ is strongly
resolved by some vertex of $W$. The smallest cardinality of a strong resolving
set for $G$ is called the {\em strong metric dimension} of $G$. It is known
that the problem of computing the strong metric dimension of a graph is
NP-hard. In this paper we obtain closed formulae for the strong metric
dimension of several families of Cartesian product graphs and direct product
graphs.


title:
Molecular Theory for Self Assembling Mixtures of Patchy Colloids and
  Colloids with Spherically Symmetric Attractions: The Single Patch Case

abstract:
  In this work we develop the first theory to model self assembling mixtures of
single patch colloids and colloids with spherically symmetric attractions. In
the development of the theory we restrict the interactions such that there are
short ranged attractions between patchy and spherically symmetric colloids, but
patchy colloids do not attract patchy colloids and spherically symmetric
colloids do not attract spherically symmetric colloids. This results in the
temperature, density and composition dependent reversible self assembly of the
mixture into colloidal star molecules. This type of mixture has been recently
synthesized by grafting of complimentary single stranded DNA [Feng et al.,
Advanced Materials 25 (20), 2779-2783 (2013)] As a quantitative test of the
theory, we perform new monte carlo simulations to study the self assembly of
these mixtures; theory and simulation are found to be in excellent agreement.


title: On the strong metric generators of strong product graphs

abstract:
  Let $G$ be a connected graph. A vertex $w\in V(G)$ strongly resolves two
vertices $u,v\in V(G)$ if there exists some shortest $u-w$ path containing $v$
or some shortest $v-w$ path containing $u$. A set $S$ of vertices is a strong
metric generator for $G$ if every pair of vertices of $G$ is strongly resolved
by some vertex of $S$. The smallest cardinality of a strong metric generator
for $G$ is called the strong metric dimension of $G$. It is well known that the
problem of computing this invariant is NP-hard. In this paper we study the
problem of finding exact values or sharp bounds for the strong metric dimension
of strong product graphs and express these in terms of invariants of the factor
graphs.


title: Thermal conductivity of the chain with an asymmetric pair interaction

abstract:
  We provide molecular dynamics simulation of heat transport in one-dimensional
molecular chains with different interparticle pair potentials. We show that the
thermal conductivity is finite in the thermodynamic limit in the chains with
the potential, which allows for bond dissociation. The Lennard-Jones, Morse and
Coulomb potentials belong to such type of potentials. The convergence of the
thermal conductivity is provided by phonon scattering on the locally stretched
loose interatomic bonds at low temperature and by the many-particle scattering
at high temperature. On the other hand, the chains with the confining pair
potential, which does not allow for the bond dissociation, posses anomalous
(diverging with the chain length) thermal conductivity. We emphasize that the
chains with the symmetric or asymmetric Fermi-Pasta-Ulam potential or with the
combined potentials containing parabolic confining potential all exhibit
anomalous heat transport.


title: Stein fillings of contact 3-manifolds obtained as Legendrian surgeries

abstract:
  In this note, we classify Stein fillings of an infinite family of contact
3-manifolds up to diffeomorphism. Some contact 3-manifolds in this family can
be obtained by Legendrian surgeries on $(S^3,\xi_{std})$ along certain
Legendrian 2-bridge knots. We also classify Stein fillings, up to symplectic
deformation, of an infinite family of contact 3-manifolds which can be obtained
by Legendrian surgeries on $(S^3,\xi_{std})$ along certain Legendrian twist
knots. As a corollary, we obtain a classification of Stein fillings of an
infinite family of contact hyperbolic 3-manifolds up to symplectic deformation.


title: Testing power-law cross-correlations: Rescaled covariance test

abstract:
  We introduce a new test for detection of power-law cross-correlations among a
pair of time series - the rescaled covariance test. The test is based on a
power-law divergence of the covariance of the partial sums of the long-range
cross-correlated processes. Utilizing a heteroskedasticity and auto-correlation
robust estimator of the long-term covariance, we develop a test with desirable
statistical properties which is well able to distinguish between short- and
long-range cross-correlations. Such test should be used as a starting point in
the analysis of long-range cross-correlations prior to an estimation of
bivariate long-term memory parameters. As an application, we show that the
relationship between volatility and traded volume, and volatility and returns
in the financial markets can be labeled as the one with power-law
cross-correlations.


title: Mutual Entropy-Production and Sensing in Bipartite Systems

abstract:
  We introduce and analyze the notion of mutual entropy-production (MEP) in
autonomous systems. Evaluating MEP rates is in general a difficult task due to
non-Markovian effects. For bipartite systems, we provide closed expressions in
various limiting regimes which we verify using numerical simulations. Based on
the study of a biochemical and an electronic sensing model, we suggest that the
MEP rates provide a relevant measure of the accuracy of sensing.


title:
Polynomiality of Hurwitz numbers, Bouchard-Mari\~no conjecture, and a
  new proof of the ELSV formula

abstract:
  In this paper we give a new proof of the ELSV formula. First, we refine an
argument of Okounkov and Pandharipande in order to prove (quasi-)polynomiality
of Hurwitz numbers without using the ELSV formula (the only way to do that
before used the ELSV formula). Then, using this polynomiality we give a new
proof of the Bouchard-Mari\~no conjecture. After that, using the correspondence
between the Givental group action and the topological recursion coming from
matrix models, we prove the equivalence of the Bouchard-Mari\~no conjecture and
the ELSV formula (it is a refinement of an argument by Eynard).


title: BaV3O8: A possible Majumdar-Ghosh system with S=1/2

abstract:
  BaV3O8 contains both magnetic V4+(S=1/2) ions and non-magnetic V5+(S=0) ions.
The V4+ ions are arranged in a coupled Majumdar-Ghosh chain like network. Our
magnetic susceptibility chi(T) data fit well with the Curie-Weiss formula in
the temperature range of 80-300K and it yields a Curie constant
C=0.39cm3K/mole-V4+ and an antiferromagnetic Weiss temperature theta=-26K. The
chi(T) curve shows a broad maximum at T~25K indicative of short-range order
(SRO) and an anomaly corresponding to long-range order (LRO) at TN~6K. The
value of the frustration index (f=mod[theta/TN]~5) suggests that the system is
moderately frustrated. Above the LRO temperature the experimental magnetic
susceptibility data match well with the coupled Majumdar-Ghosh chain model with
the ratio of the nnn (next-nearest neighbor) to nn (nearest neighbor) magnetic
coupling alpha=2 and Jnnn/kB=40K. In a mean-field approach when considering the
inter-chain interactions, we obtain the total inter-chain coupling to be about
16K. The LRO anomaly at TN is also observe in the specific heat Cp(T) data and
is not sensitive to an applied magnetic field up to 90kOe. A 51V NMR signal
corresponding to the non-magnetic vanadium was observed. Anomalies at 6K were
observed in the variation with temperature of the 51V NMR linewidth and in the
spin-lattice relaxation rate 1/T1, indicating that they are sensitive to the
LRO onset and fluctuations at the magnetic V sites. The existence of two
components (one short and another long) is observed in the spin-spin relaxation
rate 1/T2 data in the vicinity of TN. The shorter component seems to be
intimately connected with the magnetically ordered state. We suggest that both
magnetically ordered and non-long range ordered (non-LRO) regions coexist in
this compound below the long range ordering temperature.


title: A Nested Partitioning Scheme for Parallel Heterogeneous Clusters

abstract:
  Modern supercomputers are increasingly requiring the presence of accelerators
and co-processors. However, it has not been easy to achieve good performance on
such heterogeneous clusters. The key challenge has been to ensure good load
balance and that neither the CPU nor the accelerator is left idle. Traditional
approaches have offloaded entire computations to the accelerator, resulting in
an idle CPU, or have opted for task-level parallelism requiring large data
transfers between the CPU and the accelerator. True work-parallelism has been
hard as the Accelerators cannot directly communicate with other CPUs (besides
the host) and Accelerators. In this work, we present a new nested partition
scheme to overcome this problem. By partitioning the work assignment on a given
node asymmetrically into boundary and interior work, and assigning the interior
to the accelerator, we are able to achieve excellent efficiency while ensure
proper utilization of both the CPU and Accelerator resources. The problem used
for evaluating the new partition is an $hp$ discontinuous Galerkin spectral
element method for a coupled elastic--acoustic wave propagation problem.


title:
Coupled Reversible and Irreversible Bistable Switches Underlying
  TGF-\beta-induced Epithelial to Mesenchymal Transition

abstract:
  Epithelial to mesenchymal transition (EMT) plays important roles in embryonic
development, tissue regeneration and cancer metastasis. While several feedback
loops have been shown to regulate EMT, it remains elusive how they coordinately
modulate EMT response to TGF-\beta treatment. We construct a mathematical model
for the core regulatory network controlling TGF-\beta-induced EMT. Through
deterministic analyses and stochastic simulations, we show that EMT is a
sequential two-step program that an epithelial cell first transits to partial
EMT then to the mesenchymal state, depending on the strength and duration of
TGF-\beta stimulation. Mechanistically the system is governed by coupled
reversible and irreversible bistable switches. The SNAIL1/miR-34 double
negative feedback loop is responsible for the reversible switch and regulates
the initiation of EMT, while the ZEB/miR-200 feedback loop is accountable for
the irreversible switch and controls the establishment of the mesenchymal
state. Furthermore, an autocrine TGF-\beta/miR-200 feedback loop makes the
second switch irreversible, modulating the maintenance of EMT. Such coupled
bistable switches are robust to parameter variation and molecular noise. We
provide a mechanistic explanation on multiple experimental observations. The
model makes several explicit predictions on hysteretic dynamic behaviors,
system response to pulsed stimulation and various perturbations, which can be
straightforwardly tested.


title: Performance Limits of a Cloud Radio

abstract:
  Cooperation in a cellular network is seen as a key technique in managing
other cell interference to observe a gain in achievable rate. In this paper, we
present the achievable rate regions for a cloud radio network using a
sub-optimal zero forcing equalizer with dirty paper precoding. We show that
when complete channel state information is available at the cloud, rates close
to those achievable with total interference cancellation can be achieved. With
mean capacity gains, of up to 2 fold over the conventional cellular network in
both uplink and downlink, this precoding scheme shows great promise for
implementation in a cloud radio network. To simplify the analysis, we use a
stochastic geometric framework based of Poisson point processes instead of the
traditional grid based cellular network model.
  We also study the impact of limiting the channel state information and
geographical clustering to limit the cloud size on the achievable rate. We have
observed that using this zero forcing-dirty paper coding technique, the adverse
effect of inter-cluster interference can be minimized thereby transforming an
interference limited network into a noise limited network as experienced by an
average user in the network for low operating signal-to-noise-ratios. However,
for higher signal-to-noise-ratios, both the average achievable rate and
cell-edge achievable rate saturate as observed in literature. As the
implementation of dirty paper coding is practically not feasible, we present a
practical design of a cloud radio network using cloud a minimum mean square
equalizer for processing the uplink streams and use Tomlinson-Harashima
precoder as a sub-optimal substitute for a dirty paper precoder in downlink.


title: Phase separation in Fe2CrSi thin films

abstract:
  Thin films of a nominal Fe2CrSi alloy have been deposited by magnetron
co-sputtering with various heat treatments on MgO and MgAl2O4 substrates. After
heat treatment, the films were found to decompose into a nearly epitaxial Fe3Si
film with the D0$_3$ structure and Cr3Si precipitates with the A15 structure.
We explain the experimental results on the basis of ab initio calculations,
which reveal that this decomposition is energetically highly favorable.


title: On counterterms in cosmological perturbation theory

abstract:
  Cosmological perturbation theory is the theory of fluctuations (scalar as
well as tensor) around the inflationary cosmological background solution. It is
important to understand the details of the process of renormalization in this
theory. In more familiar applications of quantum field theory, the dependence
on the external momenta of the dimensionally regulated expression of the
one-loop contribution to a correlator determines the number of counter terms
(and their forms) required to renormalize it. In this work, it is pointed out
that in cosmological perturbation theory, though this still happens, it happens
in a completely different way such that in the late time limit, the information
about the number and forms of counter terms required gets erased. This is to be
compared with what happens in spontaneous symmetry breaking where the use of
fluctuation fields around a chosen vacuum seems to suggest that more counter
terms shall be needed to renormalize the theory than are actually required. We
also comment on how the field strength of curvature perturbation, $\zeta$,
could get renormalized.


title:
Temperature-driven Phase Transformation in Y_3Co: Neutron Scattering and
  First-principles Studies

abstract:
  Contrary to previous studies that identified the ground state crystal
structure of the entire R_3Co series (R is a rare earth) as orthorhombic Pnma,
we show that Y_3Co undergoes a structural phase transition at T_t=160K. Single
crystal neutron diffraction data reveal that at T_t the trigonal prisms formed
by a cobalt atom and its six nearest-neighbor yttrium atoms experience
distortions accompanied by notable changes of the Y-Co distances. The formation
of the low-temperature phase is accompanied by a pronounced lattice distortion
and anomalies seen in heat capacity and resistivity measurements. Density
functional theory calculations reveal a dynamical instability of the Pnma
structure of Y_3Co. In particular, a transversal acoustic phonon mode along the
(00z) direction has imaginary frequencies at z<1/4. Employing inelastic neutron
scattering measurements we find a strong damping of the (00z) phonon mode below
a critical temperature T_t. The observed structural transformation causes the
reduction of dimensionality of electronic bands and decreases the electronic
density of states at the Fermi level that identifies Y_3Co as a system with the
charge density wave instability.


title:
NLO QCD corrections to Higgs boson production plus three jets in gluon
  fusion

abstract:
  We report on the calculation of the cross section for Higgs boson production
in association with three jets via gluon fusion, at next-to-leading-order (NLO)
accuracy in QCD, in the infinite top-mass approximation. After including the
complete NLO QCD corrections, we observe a strong reduction in the scale
dependence of the result, and an increased steepness in the transverse momentum
distributions of both the Higgs and the leading jets. The results are obtained
with the combined use of GoSam, Sherpa, and the MadDipole/MadEvent framework.


title:
Development of a Relic Neutrino Detection Experiment at PTOLEMY:
  Princeton Tritium Observatory for Light, Early-Universe, Massive-Neutrino
  Yield

abstract:
  The PTOLEMY experiment (Princeton Tritium Observatory for Light,
Early-Universe, Massive-Neutrino Yield) aims to achieve the sensitivity
required to detect the relic neutrino background through a combination of a
large area surface-deposition tritium target, MAC-E filter methods, cryogenic
calorimetry, and RF tracking and time-of-flight systems. A small-scale
prototype is in operation at the Princeton Plasma Physics Laboratory with the
goal of validating the technologies that would enable the design of a 100 gram
PTOLEMY. With precision calorimetry in the prototype setup, the limitations
from quantum mechanical and Doppler broadening of the tritium target for
different substrates will be measured, including graphene substrates. Beyond
relic neutrino physics, sterile neutrinos contributing to the dark matter in
the universe are allowed by current constraints on partial contributions to the
number of active neutrino species in thermal equilibrium in the early universe.
The current PTOLEMY prototype is expected to have unique sensitivity in the
search for sterile neutrinos with electron-flavor content for masses of
0.1--1keV, where less stringent, 10eV, energy resolution is required. The
search for sterile neutrinos with electron-flavor content with the 100g PTOLEMY
is expected to reach the level $|U_{e4}|^2$ of $10^{-4}$--$10^{-6}$, depending
on the sterile neutrino mass.


title: Distributions of Off-Diagonal Scattering Matrix Elements: Exact Results

abstract:
  Scattering is a ubiquitous phenomenon which is observed in a variety of
physical systems which span a wide range of length scales. The scattering
matrix is the key quantity which provides a complete description of the
scattering process. The universal features of scattering in chaotic systems is
most generally modeled by the Heidelberg approach which introduces
stochasticity to the scattering matrix at the level of the Hamiltonian
describing the scattering center. The statistics of the scattering matrix is
obtained by averaging over the ensemble of random Hamiltonians of appropriate
symmetry. We derive exact results for the distributions of the real and
imaginary parts of the off-diagonal scattering matrix elements applicable to
orthogonally-invariant and unitarily-invariant Hamiltonians, thereby solving a
long standing problem.

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


title: Universality of Abrupt Holographic Quenches

abstract:
  We make an analytic investigation of rapid quenches of relevant operators in
d-dimensional holographic CFT's, which admit a dual gravity description. We
uncover a universal scaling behaviour in the response of the system, which
depends only on the conformal dimension of the quenched operator in the
vicinity of the ultraviolet fixed point of the theory. Unless the amplitude of
the quench is scaled appropriately, the work done on a system during the quench
diverges in the limit of abrupt quenches for operators with dimension
$\frac{d}{2} \le\Delta < d$.


title:
Microscopic and soliton-like solutions of the Boltzmann-Enskog and
  generalized Enskog equations for elastic and inelastic hard spheres

abstract:
  N.N. Bogolyubov discovered that the Boltzmann-Enskog kinetic equation has
microscopic solutions. They have the form of sums of delta-functions and
correspond to trajectories of individual hard spheres. But the rigorous sense
of the product of the delta-functions in the collision integral was not
discussed. Here we give a rigorous sense to these solutions by introduction of
a special regularization of the delta-functions. The crucial observation is
that the collision integral of the Boltzmann-Enskog equation coincides with
that of the first equation of the BBGKY hierarchy for hard spheres if the
special regularization to the delta-functions is applied. This allows to reduce
the nonlinear Boltzmann-Enskog equation to the BBGKY hierarchy of linear
equations in this particular case.
  Also we show that similar functions are exact smooth solutions for the
recently proposed generalized Enskog equation. They can be referred to as
"particle-like" or "soliton-like" solutions and are analogues of multisoliton
solutions of the Korteweg-de Vries equation.


title: Optical Properties of Quantum-Dot-Doped Liquid Scintillators

abstract:
  Semiconductor nanoparticles (quantum dots) were studied in the context of
liquid scintillator development for upcoming neutrino experiments. The unique
optical and chemical properties of quantum dots are particularly promising for
the use in neutrinoless double beta decay experiments. Liquid scintillators for
large scale neutrino detectors have to meet specific requirements which are
reviewed, highlighting the peculiarities of quantum-dot-doping. In this paper,
we report results on laboratory-scale measurements of the attenuation length
and the fluorescence properties of three commercial quantum dot samples. The
results include absorbance and emission stability measurements, improvement in
transparency due to filtering of the quantum dot samples, precipitation tests
to isolate the quantum dots from solution and energy transfer studies with
quantum dots and the fluorophore PPO.


title:
On the Stochastic Homogenization of Fully Nonlinear Uniformly Parabolic
  Equations in Stationary Ergodic Spatio-Temporal Media

abstract:
  We study homogenization for fully nonlinear uniformly parabolic equations in
stationary ergodic spatio-temporal media from the qualitative and quantitative
perspective. We show that under suitable hypotheses, solutions to fully
nonlinear uniformly parabolic equations in spatio-temporal media homogenize
almost surely. In addition, we obtain a rate of convergence for this
homogenization in measure, assuming that the environment is strongly mixing
with a prescribed rate. A general methodology to study the stochastic
homogenization of uniformly elliptic equations was introduced by Caffarelli,
Souganidis, and Wang, and the rate of convergence for this homogenization was
addressed by Caffarelli and Souganidis. We extend their approach to fully
nonlinear uniformly parabolic equations, and we develop a number of new
arguments to handle the parabolic structure of the problem.


title:
On the Coexistence of a Primary User with an Energy Harvesting Secondary
  User: A Case of Cognitive Cooperation

abstract:
  In this paper, we consider a cognitive scenario where an energy harvesting
secondary user (SU) shares the spectrum with a primary user (PU). The secondary
source helps the primary source in delivering its undelivered packets during
periods of silence of the primary source. The primary source has a queue for
storing its data packets, whereas the secondary source has two data queues; a
queue for storing its own packets and the other for storing the fraction of the
undelivered primary packets accepted for relaying. The secondary source is
assumed to be a battery-based node which harvests energy packets from the
environment. In addition to its data queues, the SU has an energy queue to
store the harvested energy packets. The secondary energy packets are used for
primary packets decoding and data packets transmission. More specifically, if
the secondary energy queue is empty, the secondary source can neither help the
primary source nor transmit a packet from the data queues. The energy queue is
modeled as a discrete time queue with Markov arrival and service processes. Due
to the interaction of the queues, we provide inner and outer bounds on the
stability region of the proposed system. We investigate the impact of the
energy arrival rate on the stability region. Numerical results show the
significant gain of cooperation.


title: Anisotropy-driven spin relaxation in germanium

abstract:
  A unique spin depolarization mechanism, induced by the presence of g-factor
anisotropy and intervalley scattering, is revealed by spin transport
measurements on long-distance germanium devices in a longitudinal magnetic
field. The confluence of electron-phonon scattering (leading to Elliott-Yafet
spin flips) and this previously unobserved physics enables the extraction of
spin lifetime solely from spin-valve measurements, without spin precession, and
in a regime of substantial electric-field-generated carrier heating. We find
spin lifetimes in Ge up to several hundreds of ns at low temperature, far
beyond any other available experimental results.


title: Rigidity of asymptotically conical shrinking gradient Ricci solitons

abstract:
  We show that if two gradient Ricci solitons are asymptotic along some end of
each to the same regular cone, then the soliton metrics must be isometric on
some neighborhoods of infinity of these ends. Our theorem imposes no
restrictions on the behavior of the metrics off of the ends in question and in
particular does not require their geodesic completeness. As an application, we
prove that the only complete connected gradient shrinking Ricci soliton
asymptotic to a rotationally symmetric cone is the Gaussian soliton on R^n.


title: Asymptotic of Lorentzian Polyhedra Propagator

abstract:
  A certain operator $\T=\int_{\SL}\dd g\, Y^{\dagger}gY$ can be found in
various Lorentzian EPRL calculations. The properties of this operator has been
studied here in large $j$ limit. The leading order of $\T$ is proportional to
the identity operator. Knowing the operator $\T$ one can renormalize
spin-foam's edge self-energy by computing the amplitude of sum of a series of
edges with increasing number of vertices and bubbles. This amplitude is
calculated and is shown to be convergent. Moreover some technical tools useful
in Lorentzian Spin-Foam calculation has been developed.


title:
Effective equation of state for running vacuum: "mirage" quintessence
  and phantom dark energy

abstract:
  Past analyses of the equation of state (EoS) of the Dark Energy (DE) were not
incompatible with a phantom phase near our time. This has been the case in the
years of WMAP observations, in combination with the remaining cosmological
observables. Such situation did not completely disappear from the data
collected from the Planck satellite mission. In it the EoS analysis may still
be interpreted as suggesting w<-1, and so a mildly evolving DE cannot be
discarded. In our opinion the usual ansatzs made on the structure of the EoS
for dynamical DE models (e.g. quintessence and the like) are too simplified. In
this work we examine in detail some of these issues and suggest that a general
class of models with a dynamical vacuum energy density could explain the
persistent phantom anomaly, despite there is no trace of real phantom behavior
in them. The spurious or "mirage" effect is caused by an attempt to describe
them as if the DE would be caused by fundamental phantom scalar fields.
Remarkably, the effective DE behavior can also appear as quintessence in
transit to phantom, or vice versa.


title: Casimir Energy Corrections by Light-Cone Fluctuations

abstract:
  We study the effects of light-cone fluctuations on the renormalized
zero-point energy associated with a free massless scalar field in the presence
of boundaries. In order to simulate light-cone fluctuations we introduce a
space-time dependent random coefficient in the Klein-Gordon operator. We assume
that the field is defined in a domain with one confined direction. For
simplicity, we choose the symmetric case of two parallel plates separated by a
distance $a$. The correction to the renormalized vacuum energy density between
the plates goes as $1/a^{8}$ instead of the usual $1/a^{4}$ dependence for the
free case. In turn we also show that light-cone fluctuations break down the
vacuum pressure homogeneity between the plates.


title: On the role of the basis of measurement in quantum gate teleportation

abstract:
  Quantum teleportation is a powerful protocol with applications in several
schemes of quantum communication, quantum cryptography and quantum computing.
The present work shows the required conditions for a two-qubit quantum gate to
be deterministically and probabilistically teleported by a quantum gate
teleportation scheme using different basis of measurement. Additionally, we
present examples of teleportation of two-qubit gates that do not belong to
Clifford group as well the limitations of the quantum gate teleportation scheme
employing a four-qubit state with genuine four-way entanglement.


title:
Preliminary bounds of the gravitational Local Position Invariance from
  Solar System planetary precessions

abstract:
  In the framework of the Parameterized Post-Newtonian (PPN) formalism, we
calculate the long-term Preferred Location (PL) effects, proportional to the
Whitehead parameter $\xi$, affecting all the Keplerian orbital elements of a
localized two-body system, apart from the semimajor axis $a$. They violate the
gravitational Local Position Invariance (LPI), fulfilled by General Relativity
(GR). We obtain preliminary bounds on $\xi$ by using the latest results in the
field of the Solar System planetary ephemerides. The non-detection of any
anomalous perihelion precession for Mars allows us to indirectly infer
$|\xi|\leq 5.8\times 10^{-6}$. \textcolor{black}{Such a bound is close to the
constraint, of the order of $10^{-6}$, expected from the future BepiColombo
mission to Mercury. As a complementary approach, the PL effects should be
explicitly included in the dynamical models fitted to planetary data sets to
estimate $\xi$ in a least-square fashion in a dedicated ephemerides orbit
solution.} The ratio of the anomalous perihelion precessions for Venus and
Jupiter, determined with the EPM2011 ephemerides at the $<3\sigma$ level, if
confirmed as genuine physical effects needing explanation by future studies,
rules out the hypothesis $\xi \neq 0$. A critical discussion of the $|\xi|
\lesssim 10^{-6}-10^{-7}$ upper bounds obtained in the literature from the
close alignment of the Sun's spin axis and the total angular momentum of the
Solar System is presented.


title:
General Relativistic Magnetohydrodynamic Simulations of Blandford-Znajek
  Jets and the Membrane Paradigm

abstract:
  Recently it has been observed that the scaling of jet power with black hole
spin in galactic X-ray binaries is consistent with the predictions of the
Blandford-Znajek (BZ) jet model. These observations motivate us to revisit the
BZ model using general relativistic magnetohydrodynamic simulations of
magnetized jets from accreting (h/r ~ 0.3), spinning (0 < a_* < 0.98) black
holes. We have three main results. First, we quantify the discrepancies between
the BZ jet power and our simulations: assuming maximum efficiency and uniform
fields on the horizon leads to a ~10% overestimate of jet power, while ignoring
the accretion disk leads to a further ~50% overestimate. Simply reducing the
standard BZ jet power prediction by 60% gives a good fit to our simulation
data. Our second result is to show that the membrane formulation of the BZ
model correctly describes the physics underlying simulated jets: torques,
dissipation, and electromagnetic fields on the horizon. This provides intuitive
yet rigorous pictures for the black hole energy extraction process. Third, we
compute the effective resistance of the load region and show that the load and
the black hole achieve near perfect impedance matching. Taken together, these
results increase our confidence in the BZ model as the correct description of
jets observed from astrophysical black holes.


title:
Examining the broadband emission spectrum of WASP-19b: A new z band
  eclipse detection

abstract:
  WASP-19b is one of the most irradiated hot-Jupiters known. Its secondary
eclipse is the deepest of all transiting planets, and has been measured in
multiple optical and infrared bands. We obtained a z band eclipse observation,
with measured depth of 0.080 +/- 0.029 %, using the 2m Faulkes Telescope South,
that is consistent with the results of previous observations. We combine our
measurement of the z band eclipse with previous observations to explore
atmosphere models of WASP-19b that are consistent with the its broadband
spectrum. We use the VSTAR radiative transfer code to examine the effect of
varying pressure-temperature profiles and C/O abundance ratios on the emission
spectrum of the planet. We find models with super-solar carbon enrichment best
match the observations, consistent with previous model retrieval studies. We
also include upper atmosphere haze as another dimension in the interpretation
of exoplanet emission spectra, and find that particles <0.5 micron in size are
unlikely to be present in WASP-19b.


title:
A critical shock Mach number for particle acceleration in the absence of
  pre-existing cosmic rays: $M=\sqrt 5$

abstract:
  It is shown that, under some generic assumptions, shocks cannot accelerate
particles unless the overall shock Mach number exceeds a critical value M >
sqrt(5). The reason is that for M <= sqrt(5) the work done to compress the flow
in a particle precursor requires more enthalpy flux than the system can
sustain. This lower limit applies to situations without significant magnetic
field pressure. In case that the magnetic field pressure dominates the pressure
in the unshocked medium, i.e. for low plasma beta, the resistivity of the
magnetic field makes it even more difficult to fulfil the energetic
requirements for the formation of shock with an accelerated particle precursor
and associated compression of the upstream plasma. We illustrate the effects of
magnetic fields for the extreme situation of a purely perpendicular magnetic
field configuration with plasma beta = 0, which gives a minimum Mach number of
M = 5/2. The situation becomes more complex, if we incorporate the effects of
pre-existing cosmic rays, indicating that the additional degree of freedom
allows for less strict Mach number limits on acceleration. We discuss the
implications of this result for low Mach number shock acceleration as found in
solar system shocks, and shocks in clusters of galaxies.


title: Ultraviolet Complete Technicolor and Higgs Physics at LHC

abstract:
  We construct a Technicolor model which provides masses for the electroweak
gauge bosons and for all the Standard Model matter fields. Starting from an
ultraviolet complete supersymmetric technicolor, we propose a scenario where
all elementary scalars, gauginos, and higgsinos are decoupled at an energy
scale substantially higher than the electroweak scale, therefore avoiding the
little hierarchy problem of the minimal supersymmetric standard model. The
resulting low energy theory has an SU(3) global symmetry whose breaking to
SO(3) leads to electroweak symmetry breaking. We study in detail the
phenomenology of this theory and demonstrate that it reproduces the present LHC
data at the same level of precision as the Standard Model itself.


title:
Young stellar clusters in the Rosette molecular cloud. Arguments against
  triggered star formation

abstract:
  The Rosette complex is a well studied region of the galactic plane which
presents the apparent characteristics of a triggered star forming region. This
is however still debated as no strong evidence corroborates this statement. We
focus on characterizing the young stellar population in the Rosette complex to
improve our understanding of the processes that regulate the star formation in
this region. We propose an original method that relies on the joint analysis of
the star color and density in the near-infrared. It leads to mapping the
molecular cloud spatial distribution and detecting the embedded clusters with
their characterization in terms of member number and age estimation. We have
identified 13 clusters, 2 of which are new discoveries, and we estimate that
the total number of young stellar objects in the Rosette ranges between 4000
and 8000 members. We find that the age distribution of the young clusters is
not consistent with a general triggered scenario for the star formation in this
molecular cloud. This study proves that the Rosette complex evolution is not
governed by the influence of its OB star population. It suggests that the
simple morphological appearance of an active region is not sufficient to
conclude much about the triggering role in the star formation process. Our
method of constraining the cluster properties using UKIDSS and WISE data has
proven efficient, and studies of other regions of the galactic plane would
definitely benefit from this approach.


title:
The fraction of first and second generation stars in globular clusters.
  I The case of NGC 6752

abstract:
  We present a new method to estimate the fraction of stars with chemical
composition of first and second(s) generation(s) currently hosted in Galactic
globular clusters (GCs). We compare cluster and field stars of similar
metallicity in the [Fe/H]-[Na/H] plane. Since the phenomenon of multiple
populations is only restricted to the cluster environment, the number of GC
stars whose location coincides with that of field stars provides the fraction
of first generation stars in that cluster. By exclusion, the fraction of second
generation stars is derived. We assembled a dataset of 1891 field stars of the
thin disk, thick disk, and halo of the Milky Way in the metallicity range -3.15
<= [Fe/H] <= +0.48 dex and with Na abundance from high resolution spectra. They
are mostly dwarfs, but include also giants. Considering only the range in
metallicity spanned by most GCs extensively studied for the Na-O
anticorrelation (-2.36 <= [Fe/H] <= -0.33 dex), we have 804 stars. The total
sample is homogeneized by offsets in [Fe/H] and [Na/H] with respect to a
reference sample using the same line list and NLTE correction for Na adopted in
a recent extensive survey of GC stars. This fully accounts for offsets among
analyses due to different temperature scales, line lists, adopted (or
neglected) corrections for departures from LTE. We illustrate our method
estimating the fraction of first and second generation stars in the well
studied GC NGC 6752. As a by-product, the comparison of [Na/H] values in GC and
field stars suggests that at least two classes of old stellar systems probably
contributed to the halo assembly: one group with characteristics similar to the
currently existing GCs, and the other more similar to the present-day dwarf
satellite galaxies.


title: Stars were born in significantly denser regions in the early Universe

abstract:
  The density of the warm ionized gas in high-redshift galaxies is known to be
higher than what is typical in local galaxies on similar scales. At the same
time, the mean global properties of the high- and low-redshift galaxies are
quite different. Here, we present a detailed differential analysis of the
ionization parameters of 14 star-forming galaxies at redshift 2.6-3.4, compiled
from the literature. For each of those high-redshift galaxies, we construct a
comparison sample of low-redshift galaxies closely matched in specific star
formation rate (sSFR) and stellar mass, thus ensuring that their global
physical conditions are similar to the high-redshift galaxy. We find that the
median log [OIII] 5007/ [OII] 3727 line ratio of the high-redshift galaxies is
0.5 dex higher than their local counterparts. We construct a new calibration
between the [OIII] 5007/ [OII] 3727 emission line ratio and ionization
parameter to estimate the difference between the ionization parameters in the
high and low-redshift samples. Using this, we show that the typical density of
the warm ionized gas in star-forming regions decreases by a median factor of
$7.1^{+10.2}_{-5.4}$ from z ~ 3.3 to z ~ 0 at fixed mass and sSFR. We show that
metallicity differences cannot explain the observed density differences.
Because the high- and low-redshift samples are comparable in size, we infer
that the relationship between star formation rate density and gas density must
have been significantly less efficient at z ~2-3 than what is observed in
nearby galaxies with similar levels of star formation activity.


title:
The SL2S Galaxy-scale Lens Sample. IV. The dependence of the total mass
  density profile of early-type galaxies on redshift, stellar mass, and size

abstract:
  We present optical and near infrared spectroscopy obtained at Keck, VLT, and
Gemini for a sample of 36 secure strong gravitational lens systems and 17
candidates identified as part of the SL2S survey. The deflectors are massive
early-type galaxies in the redshift range z_d=0.2-0.8, while the lensed sources
are at z_s=1-3.5. We combine this data with photometric and lensing
measurements presented in the companion paper III and with lenses from the
SLACS and LSD surveys to investigate the cosmic evolution of the internal
structure of massive early-type galaxies over half the age of the universe. We
study the dependence of the slope of the total mass density profile \gamma'
(\rho(r)\propto r^{-\gamma'}) on stellar mass, size, and redshift. We find that
two parameters are sufficent to determine \gamma' with less than 6% residual
scatter. At fixed redshift, \gamma' depends solely on the surface stellar mass
density \partial \gamma'/ \partial \Sigma_*=0.38\pm 0.07, i.e. galaxies with
denser stars also have steeper slopes. At fixed M_* and R_{eff}, \gamma'
depends on redshift, in the sense that galaxies at a lower redshift have
steeper slopes (\partial \gamma' / \partial z = -0.31\pm 0.10). However, the
mean redshift evolution of \gamma' for an individual galaxy is consistent with
zero d\gamma'/dz=-0.10\pm0.12. This result is obtained by combining our
measured dependencies of \gamma' on z,M_*,R_{eff} with the evolution of the
R_{eff}-M_* taken from the literature, and is broadly consistent with current
models of the formation and evolution of massive early-type galaxies. Detailed
quantitative comparisons of our results with theory will provide qualitatively
new information on the detailed physical processes at work.


title: Habitability of Exomoons at the Hill or Tidal Locking Radius

abstract:
  Moons orbiting extrasolar planets are the next class of object to be observed
and characterized for possible habitability. Like the host-planets to their
host-star, exomoons have a limiting radius at which they may be gravitationally
bound, or the Hill radius. In addition, they also have a distance at which they
will become tidally locked and therefore in synchronous rotation with the
planet. We have examined the flux phase profile of a simulated, hypothetical
moon orbiting at a distant radius around the confirmed exoplanets mu Ara b, HD
28185 b, BD +14 4559 b, and HD 73534 b. The irradiated flux on a moon at it's
furthest, stable distance from the planet achieves it's largest flux gradient,
which places a limit on the flux ranges expected for subsequent (observed)
moons closer in orbit to the planet. We have also analyzed the effect of
planetary eccentricity on the flux on the moon, examining planets that traverse
the habitable zone either fully or partially during their orbit. Looking solely
at the stellar contributions, we find that moons around planets that are
totally within the habitable zone experience thermal equilibrium temperatures
above the runaway greenhouse limit, requiring a small heat redistribution
efficiency. In contrast, exomoons orbiting planets that only spend a fraction
of their time within the habitable zone require a heat redistribution
efficiency near 100% in order to achieve temperatures suitable for
habitability.
  Meaning, a planet does not need to spend its entire orbit within the
habitable zone in order for the exomoon to be habitable. Because the applied
systems are comprised of giant planets around bright stars, we believe that the
transit detection method is most likely to yield an exomoon discovery.


title:
Secular Behavior of Exoplanets: Self-Consistency and Comparisons with
  the Planet-Planet Scattering Hypothesis

abstract:
  If mutual gravitational scattering among exoplanets occurs, then it may
produce unique orbital properties. For example, two-planet systems that lie
near the boundary between circulation and libration of their periapses could
result if planet-planet scattering ejected a former third planet quickly,
leaving one planet on an eccentric orbit and the other on a circular orbit. We
first improve upon previous work that examined the apsidal behavior of known
multiplanet systems by doubling the sample size and including observational
uncertainties. This analysis recovers previous results that demonstrated that
many systems lay on the apsidal boundary between libration and circulation. We
then performed over 12,000 three-dimensional N-body simulations of hypothetical
three-body systems that are unstable, but stabilize to two-body systems after
an ejection. Using these synthetic two-planet systems, we test the
planet-planet scattering hypothesis by comparing their apsidal behavior, over a
range of viewing angles, to that of the observed systems and find that they are
statistically consistent regardless of the multiplicity of the observed
systems. Finally, we combine our results with previous studies to show that,
from the sampled cases, the most likely planetary mass function prior to
planet-planet scattering follows a power law with index -1.1. We find that this
pre-scattering mass function predicts a mutual inclination frequency
distribution that follows an exponential function with an index between -0.06
and -0.1.


title:
Modelling the nucleosynthetic properties of carbon-enhanced metal-poor
  RR Lyrae stars

abstract:
  Certain carbon-enhanced metal-poor stars likely obtained their composition
via pollution from some of the earliest generations of asymptotic giant branch
stars and as such provide important clues to early Universe nucleosynthesis.
Recently, Kinman et al. discovered that the highly carbon- and barium-enriched
metal-poor star SDSS J1707+58 is in fact an RR Lyrae pulsator. This gives us an
object in a definite evolutionary state where the effects of dilution of
material during the Main Sequence are minimised owing to the object having
passed through first dredge-up. We perform detailed stellar modelling of
putative progenitor systems in which we accreted material from asymptotic giant
branch stars in the mass range 1-2 solar masses. We investigate how the surface
abundances are affected by the inclusion of mechanisms like thermohaline mixing
and gravitational settling. While we are able to find a reasonable fit to the
carbon and sodium abundances of SDSS J1707+58, suggesting accretion of around
0.1 solar masses from a 2 solar mass companion, the strontium and barium
abundances remain problematic and this object may have experienced something
other than a standard $s$ process. We have more success in fitting the
abundances of the mildly carbon-enriched, metal-poor RR Lyrae pulsator TY Gru
(CS 22881-071), which we suggest received 0.1 solar masses of material from a
companion of around 1 solar mass.


title: High-resolution spectroscopic imaging of CO in a z=4.05 proto-cluster

abstract:
  We present a study of the formation of clustered, massive galaxies at large
look-back times via spectroscopic imaging of CO in the unique GN20
proto-cluster at z = 4.05. Existing observations show that this is a dense
concentration of gas-rich, very active star forming galaxies, including
multiple bright submillimeter galaxies (SMGs). Using deep, high-resolution VLA
CO(2-1) observations, we image the molecular gas with a resolution of ~1 kpc
just 1.6 Gyr after the Big Bang. The SMGs GN20.2a and GN20.2b have deconvolved
sizes of ~5 kpc X 3 kpc and ~8 kpc X 5 kpc (Gaussian FWHM) in CO(2-1),
respectively, and we measure gas surface densities up to ~12,700/1,700X(sin i)
(\alpha_CO/0.8) M_sun/pc^2 for GN20.2a/GN20.2b in the highest-resolution maps.
Dynamical mass estimates allow us to constrain the CO-to-H_2 conversion factor
to \alpha_CO = 1.7+/-0.8 M_sun (K km s^{-1} pc^2)^-1 for GN20.2a and \alpha_CO
= 1.1+/-^{1.5}_{1.1} M_sun (K km/s pc^2)^-1 for GN20.2b. We measure significant
offsets (0.5"-1") between the CO and optical emission, indicating either dust
obscuration on scales of tens of kpc or that the emission originates from
distinct galaxies. CO spectral line energy distributions imply physical
conditions comparable to other SMGs and reveal further evidence that GN20.2a
and GN20.2b are in different merging stages. We carry out a targeted search for
CO emission from the 14 known B-band Lyman break galaxies (LBGs) in the field,
tentatively detecting CO in a previously-undetected LBG and placing 3sigma
upper limits on the CO luminosities of those that may lie within our bandpass.
A blind search for emission line sources down to a 5sigma limiting CO
luminosity of L'_CO(2-1) = 8 X 10^9 K km/s pc^2 and covering \Delta z = 0.0273
(~20 comoving Mpc) produces no other strong contenders associated with the
proto-cluster.


title:
The SL2S Galaxy-scale Lens Sample. III. Lens Models, Surface Photometry
  and Stellar Masses for the final sample

abstract:
  We present Hubble Space Telescope (HST) imaging data and CFHT Near IR
ground-based images for the final sample of 56 candidate galaxy-scale lenses
uncovered in the CFHT Legacy Survey as part of the Strong Lensing in the Legacy
Survey (SL2S) project. The new images are used to perform lens modeling,
measure surface photometry, and estimate stellar masses of the deflector
early-type galaxies. Lens modeling is performed on the HST images (or CFHT when
HST is not available) by fitting the spatially extended light distribution of
the lensed features assuming a singular isothermal ellipsoid mass profile and
by reconstructing the intrinsic source light distribution on a pixelized grid.
Based on the analysis of systematic uncertainties and comparison with inference
based on different methods we estimate that our Einstein Radii are accurate to
\sim3%. HST imaging provides a much higher success rate in confirming
gravitational lenses and measuring their Einstein radii than CFHT imaging does.
Lens modeling with ground-based images however, when successful, yields
Einstein radius measurements that are competitive with spaced-based images.
Information from the lens models is used together with spectroscopic
information from the companion paper IV to classify the systems, resulting in a
final sample of 39 confirmed (grade-A) lenses and 17 promising candidates. The
redshifts of the main deflector span a range 0.3<zd< 0.8, providing an
excellent sample for the study of the cosmic evolution of the mass distribution
of early-type galaxies over the second half of the history of the Universe.


title: Adaptive testing for the graphical lasso

abstract:
  We consider tests of significance in the setting of the graphical lasso for
inverse covariance matrix estimation. We propose a simple test statistic based
on a subsequence of the knots in the graphical lasso path. We show that this
statistic has an exponential asymptotic null distribution, under the null
hypothesis that the model contains the true connected components.
  Though the null distribution is asymptotic, we show through simulation that
it provides a close approximation to the true distribution at reasonable sample
sizes. Thus the test provides a simple, tractable test for the significance of
new edges as they are introduced into the model. Finally, we show connections
between our results and other results for regularized regression, as well as
extensions of our results to other correlation matrix based methods like
single-linkage clustering.


title: Matrix Units in the Symmetric Group Algebra, and Unitary Integration

abstract:
  In this paper, we establish an explicit isomorphism between the symmetric
group algebra and the path algebra of the Young graph. Specifically, we
construct a family of matrix units in the group algebra. As a main application
of this construction, we obtain new formulas, alternative to Weingarten
calculus, for the integral of a polynomial over the unitary group with respect
to the Haar measure. In particular, we obtain a closed formula for the law of
moments of the first k rows of the unitary group.


title:
Model for the catalytic oxidation of CO, including gas-phase impurities
  and CO desorption

abstract:
  We present results of kinetic Monte Carlo simulations of a modified
Ziff-Gulari-Barshad model for the reaction CO+O --> CO_2 on a catalytic
surface. Our model includes impurities in the gas phase, CO desorption, and a
modification known to eliminate the unphysical O poisoned phase. The impurities
can adsorb and desorb on the surface, but otherwise remain inert. In a previous
work that did not include CO desorption [G. M. Buendia and P. A. Rikvold, Phys.
Rev. E, 85 031143 (2012)], we found that the impurities have very distinctive
effects on the phase diagram and greatly diminish the reactivity of the system.
If the impurities do not desorb, once the system reaches a stationary state,
the CO_2 production disappears. When the impurities are allowed to desorb,
there are regions where the CO_2 reaction window reappears, although greatly
reduced. Following experimental evidence that indicates that temperature
effects are crucial in many catalytic processes, here we further analyze these
effects by including a CO desorption rate. We find that the CO desorption has
the effect to smooth the transition between the reactive and the CO rich phase,
and most importantly it can counteract the negative effects of the presence of
impurities by widening the reactive window such that now the system remains
catalytically active in the whole range of CO pressures.


title: Higher spin theory in 3-dimensional flat space

abstract:
  We present the first example of a non-trivial higher spin theory in
3-dimensional flat space. We propose flat-space boundary conditions and prove
their consistency for this theory. We find that the asymptotic symmetry algebra
is a (centrally extended) higher spin generalization of the Bondi-
Metzner-Sachs algebra, which we describe in detail. We also address higher spin
analogues of flat space cosmology solutions and possible generalizations.


title: Complete Decoupling Limit of Ghost-free Massive Gravity

abstract:
  We present the complete form of the decoupling limit of ghost-free massive
gravity with a Minkowski reference metric, including the full interactions of
the helicity-1 and helicity-0 modes of the massive spin-2 field. While in the
metric language the square root structure of the mass terms makes it difficult
to find a simple way to write down the interactions, we show that using the
vierbein formulation of massive gravity, including Stueckelberg fields for both
diffeomorphism and local Lorentz symmetries, we can find an explicitly resummed
expression for the helicity-1 field interactions. We clarify the equations of
motion for the Lorentz Stueckelberg fields and how these generate the symmetric
vierbein condition which guarantees equivalence between the vierbein and metric
formulations of massive gravity.


title:
Effects of Phase Fluctuations on Phase Sensitivity and Visibility of
  Path-Entangled Photon Fock States

abstract:
  We study effects of phase fluctuations on phase sensitivity and visibility of
a class of robust path-entangled photon Fock states (known as mm' states) as
compared to the maximally path-entangled N00N states in presence of realistic
phase fluctuations such as turbulence noise. Our results demonstrate that the
mm' states, which are more robust than the N00N state against photon loss,
perform equally well when subject to such fluctuations. We show that the phase
sensitivity with parity detection for both of the above states saturates the
quantum Cramer-Rao bound in presence of such noise, suggesting that the parity
detection presents an optimal detection strategy.


title: Abelian varieties in Brill--Noether loci

abstract:
  In this paper, improving on results of Abramovich- Harris and Debarre-
Fahlaoui we give the full classification of curves C of genus g such that a
Brill--Noether locus W^ s_d(C), strictly contained in the jacobian J(C) of C,
contains a variety Z stable under translations by the elements of a positive
dimensional abelian subvariety A contained in J(C) and such that
dim(Z)=d-dim(A)-2s, i.e., the maximum possible for such a Z.


title: Ideal hypersurfaces of Euclidean four-space

abstract:
  The notion of ideal immersions was introduced by the author in 1990s. Roughly
speaking, an ideal immersion of a Riemannian manifold into a real space form is
a nice isometric immersion which produces the least possible amount of tension
from the ambient space at each point.
  In this paper, we classify all ideal hypersurfaces with two distinct
principal curvatures in the Euclidean 4-space $\mathbb E^4$. Moreover, we prove
that such ideal hypersurfaces are always rigid. Furthermore, we show that
non-minimal ideal hypersurfaces with three distinct principal curvatures in
$\mathbb E^4$ are also rigid. On the other hand, we provide explicit examples
to illustrate that minimal ideal hypersurfaces with three principal curvatures
in $\mathbb E^4$ are not necessarily rigid.


title:
Yukawa sector of Multi Higgs Doublet Models in the presence of Abelian
  symmetries

abstract:
  A general method for classifying the possible quark models of a
multi-Higgs-doublet model, in the presence of Abelian symmetries, is presented.
All the possible sets of textures that can be present in a given sector are
shown, thus turning the determination of the flavor models into a combinatorial
problem. Several symmetry implementations are studied for two and three Higgs
doublet models. Some models implementations are explored in great detail, with
a particular emphasis on models known as Branco-Grimus-Lavoura and
nearest-neighbour-nnteraction. Several considerations on the flavor changing
neutral currents of multi-Higgs models are also given.


title:
Nonadiabatic Effects in Ultracold Molecules via Anomalous Linear and
  Quadratic Zeeman Shifts

abstract:
  Anomalously large linear and quadratic Zeeman shifts are measured for weakly
bound ultracold $^{88}$Sr$_2$ molecules near the intercombination-line
asymptote. Nonadiabatic Coriolis coupling and the nature of long-range
molecular potentials explain how this effect arises and scales roughly
cubically with the size of the molecule. The linear shifts yield nonadiabatic
mixing angles of the molecular states. The quadratic shifts are sensitive to
nearby opposite $f$-parity states and exhibit fourth-order corrections,
providing a stringent test of a state-of-the-art \textit{ab initio} model.


title: Magnetic Field Induced Transition in Vanadium Spinels

abstract:
  We study vanadium spinels $A$V$_2$O$_4$ ($A$ = Cd, Mg) in pulsed magnetic
fields up to 65 T. A jump in magnetization at $\mu_0 H \approx$ 40 T is
observed in the single-crystal MgV$_2$O$_4$, indicating a field induced quantum
phase transition between two distinct magnetic orders. In the multiferroic
CdV$_2$O$_4$, the field-induced transition is accompanied by a suppression of
the electric polarization. By modeling the magnetic properties in the presence
of strong spin-orbit coupling characteristic of vanadium spinels, we show that
both features of the field-induced transition can be successfully explained by
including the effects of the local trigonal crystal field.


title: Stressless Schwarzschild

abstract:
  This self-contained pedagogical derivation of the Schwarzchild solution, in
"3 + 1" formulation and conformal spatial gauge, (almost) avoids all affinity,
curvature and index gymnastics.


title:
On the local constants of simple supercuspidal representations of
  GL(n,F)

abstract:
  In this paper, we explicitly compute the standard epsilon factors on both
sides of the local Langlands correspondence for simple supercuspidal
representations of GL(n,F).


title: Radiative corrections to the composite Higgs mass from a gluon partner

abstract:
  In composite Higgs models light fermionic top partners often play an
important role in obtaining a 126 GeV Higgs mass. The presence of these top
partners implies that coloured vector mesons, or massive gluon partners, most
likely exist. Since the coupling between the top partners and gluon partners
can be large there are then sizeable two-loop contributions to the composite
Higgs mass. We compute the radiative correction to the Higgs mass from a gluon
partner in the minimal composite Higgs model and show that the Higgs mass is in
fact reduced. This allows the top partner masses to be increased, easing the
tension between having a light composite Higgs and heavy top partners.


title: Open Cell Metal Foams for Beam Liners?

abstract:
  The possible use of open-cell metal foams for particle accelerator beam
liners is considered. Available materials and modeling tools are reviewed,
potential pros and cons are pointed out, and a study program is outlined.


title:
Damped-Driven Granular Crystals: An Ideal Playground for Dark Breathers
  and Multibreathers

abstract:
  By applying an out-of-phase actuation at the boundaries of a uniform chain of
granular particles, we demonstrate experimentally that time-periodic and
spatially localized structures with a nonzero background (so-called dark
breathers) emerge for a wide range of parameter values and initial conditions.
Importantly, the number of ensuing breathers within the multibreather pattern
produced can be "dialed in" by varying the frequency or amplitude of the
actuation. The values of the frequency (resp. amplitude) where the transition
between different multibreather states occurs are predicted accurately by the
proposed theoretical model, which is numerically shown to support exact dark
breather solutions. The existence, linear stability, and bifurcation structure
of the theoretical dark breathers are also studied in detail. Moreover, the
distributed sensing technologies developed herein enable a detailed space-time
probing of the system and a systematic favorable comparison between theory,
computation and experiments.


title: Recovery of time dependent volatility coefficient by linearization

abstract:
  We study the problem of reconstruction of special special time dependent
local volatility from market prices of options with different strikes at two
expiration times. For a general diffusion process we apply the linearization
technique and we conclude that the option price can be obtained as the sum of
the Black-Scholes formula and of an operator $W$ which is linear in
perturbation of volatility. We further simplify the linearized inverse problem
and obtain unique solvability result in basic functional spaces. By using the
Laplace transform in time we simplify the kernels of integral operators for $W$
and we obtain uniqueness and stability results for for volatility under natural
condition of smallness of the spacial interval where one prescribes the
(market) data. We propose a numerical algorithm based on our analysis of the
linearized problem.


title: Local-global questions for tori over $p$-adic function fields

abstract:
  We study local-global questions for Galois cohomology over the function field
of a curve defined over a p-adic field (a field of cohomological dimension 3).
We define Tate-Shafarevich groups of a commutative group scheme via cohomology
classes locally trivial at each completion of the base field coming from a
closed point of the curve. In the case of a torus we establish a perfect
duality between the first Tate-Shafarevich group of the torus and the second
Tate-Shafarevich group of the dual torus. As an application, we show that the
failure of the local-global principle for rational points on principal
homogeneous spaces under tori is controlled by a certain subquotient of a third
etale cohomology group. We also prove a generalization to principal homogeneous
spaces of certain reductive group schemes in the case when the base curve has
good reduction.


title: Weak approximation for tori over $p$-adic function fields

abstract:
  This is the companion piece to "Local-global questions for tori over p-adic
function fields" by the first and third authors. We study local-global
questions for Galois cohomology over the function field of a curve defined over
a p-adic field, the main focus here being weak approximation of rational
points. We construct a 9-term Poitou--Tate type exact sequence for tori over a
field as above (and also a 12-term sequence for finite modules). Like in the
number field case, part of the sequence can then be used to analyze the defect
of weak approximation for a torus. We also show that the defect of weak
approximation is controlled by a certain subgroup of the third unramified
cohomology group of the torus.


title:
On the large interelectronic distance behavior of the correlation factor
  for explicitly correlated wave functions

abstract:
  In currently most popular explicitly correlated electronic structure theories
the dependence of the wave function on the interelectronic distance rij is
built via the correlation factor f(rij). While the short-distance behavior of
this factor is well understood, little is known about the form of f(rij) at
large rij. In this work we investigate the optimal form of f(r12) on the
example of the helium atom and helium-like ions and several well-motivated
models of the wave function. Using the Rayleigh-Ritz variational principle we
derive a differential equation for f(r12) and solve it using numerical
propagation or analytic asymptotic expansion techniques. We found that for
every model under consideration, f(r12) behaves at large r12 as r12^{\rho}
exp(B r12) and obtained simple analytic expressions for the system dependent
values of {\rho} and B. For the ground state of the helium-like ions the value
of B is positive, so that f(r12) diverges as r12 tends to infinity. The
numerical propagation confirms this result. When the Hartree-Fock orbitals,
multiplied by the correlation factor, are expanded in terms of Slater functions
r^n exp(-{\beta}r), the numerical propagation reveals a minimum in f(r12) with
depth increasing with N. For the lowest triplet state B is negative. Employing
our analytical findings, we propose a new 'range-separated' form of the
correlation factor with the short- and long-range r12 regimes approximated by
appropriate asymptotic formulas connected by a switching function. Exemplary
calculations show that this new form of f(r12) performs somewhat better than
the correlation factors used thus far in the standard R12 or F12 theories.


title: The Voevodsky motive of a rank one semiabelian variety

abstract:
  Over a perfect field k, let G be an extension of an abelian variety by the
multiplicative group $\G_m$. We compute the motive of G in Voevodsky's category
of etale motivic complexes with rational coefficients. The result is a
decomposition similar to the classical decomposition of the Chow motive of an
abelian variety obtained by Deninger/Murre, Kuennemann, Shermenev and Scholl,
and other authors.


title:
Supernovae: an example of complexity in the physics of compressible
  fluids

abstract:
  The supernovae are typical complex phenomena in fluid mechanics with very
different time scales. We describe them in the light of catastrophe theory,
assuming that successive equilibria between pressure and gravity present a
saddle-node bifurcation. In the early stage we show that the loss of
equilibrium may be described by a generic equation of the Painlev\'e I form. In
the final stage of the collapse, just before the divergence of the central
density, we show that the existence of a self-similar collapsing solution
compatible with the numerical observations imposes that the gravity forces are
stronger than the pressure ones. This situation differs drastically in its
principle from the one generally admitted where pressure and gravity forces are
assumed to be of the same order. Our new self-similar solution (based on the
hypothesis of dominant gravity forces) which matches the smooth solution of the
outer core solution, agrees globally well with our numerical results. Whereas
some differences with the earlier self-similar solutions are minor, others are
very important. For example, we find that the velocity field becomes singular
at the collapse time, diverging at the center, and decreasing slowly outside
the core, whereas previous works described a finite velocity field in the core
which tends to a supersonic constant value at large distances. This discrepancy
should be important for explaining the emission of remnants in the
post-collapse regime. Finally we describe the post-collapse dynamics, when mass
begins to accumulate in the center, also within the hypothesis that gravity
forces are dominant.


title: A Comprehensive Scan for Heterotic SU(5) GUT models

abstract:
  Compactifications of heterotic theories on smooth Calabi-Yau manifolds
remains one of the most promising approaches to string phenomenology. In two
previous papers, http://arXiv.org/abs/arXiv:1106.4804 and
http://arXiv.org/abs/arXiv:1202.1757, large classes of such vacua were
constructed, using sums of line bundles over complete intersection Calabi-Yau
manifolds in products of projective spaces that admit smooth quotients by
finite groups. A total of 10^12 different vector bundles were investigated
which led to 202 SU(5) Grand Unified Theory (GUT) models. With the addition of
Wilson lines, these in turn led, by a conservative counting, to 2122 heterotic
standard models. In the present paper, we extend the scope of this programme
and perform an exhaustive scan over the same class of models. A total of 10^40
vector bundles are analysed leading to 35,000 SU(5) GUT models. All of these
compactifications have the right field content to induce low-energy models with
the matter spectrum of the supersymmetric standard model, with no exotics of
any kind. The detailed analysis of the resulting vast number of heterotic
standard models is a substantial and ongoing task in computational algebraic
geometry.


title: Renormalized volume and the evolution of APEs

abstract:
  We study the evolution of the renormalized volume functional for
asymptotically Poincare-Einstein metrics (M,g) which are evolving by normalized
Ricci flow. In particular, we prove that the time derivative of the
renormalized volume along the flow is the negative integral of scal(g(t)) +
n(n-1) over the manifold. This implies that if scal(g(0))+n(n-1) is
non-negative at t=0, then the renormalized volume decreases monotonically.
  We also discuss how, when n=4, our results describe the Hawking-Page phase
transition. Differences in renormalized volumes give rigorous meaning to the
Hawking-Page difference of actions and describe the free energy liberated in
the transition.


title: Reproductive Value in Graph-structured Populations

abstract:
  Evolutionary graph theory has grown to be an area of intense study. Despite
the amount of interest in the field, it seems to have grown separate from other
subfields of population genetics and evolution. In the current work I introduce
the concept of Fisher's (1930) reproductive value into the study of evolution
on graphs. Reproductive value is a measure of the expected genetic contribution
of an individual to a distant future generation. In a heterogeneous
graph-structured population, differences in the number of connections among
individuals translates into differences in the expected number of offspring,
even if all individuals have the same fecundity. These differences are
accounted for by reproductive value. The introduction of reproductive value
permits the calculation of the fixation probability of a mutant in a neutral
evolutionary process in any graph-structured population for either the moran
birth-death or death-birth process.


title: Time-Frequency Foundations of Communications

abstract:
  In the tradition of Gabor's 1946 landmark paper [1], we advocate a
time-frequency (TF) approach to communications. TF methods for communications
have been proposed very early (see the box History). While several tutorial
papers and book chapters on the topic are available (see, e.g., [2]-[4] and
references therein), the goal of this paper is to present the fundamental
aspects in a coherent and easily accessible manner. Specifically, we establish
the role of TF methods in communications across a range of subject areas
including TF dispersive channels, orthogonal frequency division multiplexing
(OFDM), information-theoretic limits, and system identification and channel
estimation. Furthermore, we present fundamental results that are stated in the
literature for the continuous-time case in simple linear algebra terms.


title:
Quasilocal energy for three-dimensional massive gravity solutions with
  chiral deformations of AdS boundary conditions

abstract:
  We consider critical gravity in three dimensions; that is, the New Massive
Gravity theory formulated about Anti-de Sitter (AdS) space with the specific
value of the graviton mass for which it results dual to a two-dimensional
conformal field theory with vanishing central charge. As it happens with Kerr
black holes in four-dimensional critical gravity, in three-dimensional critical
gravity the Banados-Teitelboim-Zanelli black holes have vanishing mass and
vanishing angular momentum. However, provided suitable asymptotic conditions
are chosen, the theory may also admit solutions carrying non-vanishing charges.
Here, we give simple examples of exact solutions that exhibit falling-off
conditions that are even weaker than those of the so-called Log-gravity. For
such solutions, we define the quasilocal stress-tensor and use it to compute
conserved charges. Despite the drastic deformation of AdS3 asymptotic, these
solutions have finite mass and angular momentum.


title:
Weighted-residual methods for the solution of two-particle
  Lippmann-Schwinger equation without partial-wave decomposition

abstract:
  Recently there has been a growing interest in computational methods for
quantum scattering equations that avoid the traditional decomposition of wave
functions and scattering amplitudes into partial waves.The aim of the present
work is to show that the weighted-residual approach in combination with local
basis functions give rise to convenient computational schemes for the solution
of the multi-variable integral equations without the partial wave expansion.The
weighted-residual approach provides a unifying framework for various
variational and degenerate-kernel methods for integral equations of scattering
theory. Using a direct-product basis of localized quadratic interpolation
polynomials,Galerkin, collocation and Schwinger variational realizations of the
weighted-residual approach have been implemented for a model potential. It is
demonstrated that, for a given expansion basis, Schwinger variational method
exhibits better convergence with basis size than Galerkin and collocation
methods. A novel hybrid-collocation method is implemented with promising
results as well.