title:
Sensor Setups for State and Wind Estimation for Airborne Wind Energy
  Converters

abstract:
  An unscented Kalman filter with joint state and parameter estimation is
proposed for aerodynamics, states and wind conditions for airborne wind energy
converters. The proposed estimator relies on different measurement setups. Due
to the strict economic constraints of wind energy converters, the sensor setups
are chosen with minimal cost and reliability issues in mind. Simulation data
with a high fidelity system model and experimental tests using flight data,
together with wind measurements obtained using a lidar system for altitude wind
measurements, are used for validation. The data was obtained during test
flights of the EnerK\'ite EK30, an airborne wind energy converter currently in
research operation in Brandenburg, Germany. Feasible accuracies were achieved
even with the simplest of setups and illustrate the gain achievable by airborne
sensors. Additionally, the results encourage further research into use of the
obtained wind estimates for site assessment.


title: Hyper-expansive Homeomorphisms

abstract:
  A homeomorphism on a compact metric space is said hyper-expansive if every
pair of different compact sets are separated by the homeomorphism in the
Hausdorff metric. We characterize such dynamics as those with a finite number
of orbits and whose non-wandering set is the union of the repelling and the
attracting periodic orbits. We also give a characterization of compact metric
spaces admiting hyper-expansive homeomorphisms.


title: From rational Godel logic to continuous ultrametric logic

abstract:
  This paper is devoted to systematic studies of some extensions of first-order
G\"odel logic. The first extension is the first-order rational G\"odel logic
which is an extension of first-order G\"odel logic, enriched by countably many
nullary logical connectives. By introducing some suitable semantics and proof
theory, it is shown that the first-order rational G\"odel logic has the
completeness property, that is any (strongly) consistent theory is satisfiable.
Furthermore, two notions of entailment and strong entailment are defined and
their relations with the corresponding notion of proof is studied. In
particular, an approximate entailment-compactness is shown. Next, by adding a
binary predicate symbol $d$ to the first-order rational G\"odel logic, the
ultrametric logic is introduced. This serves as a suitable framework for
analyzing structures which carry an ultrametric function $d$ together with some
functions and predicates which are uniformly continuous with respect to the
ultrametric $d$. Some model theory is developed and to justify the relevance of
this model theory, the Robinson joint consistency theorem is proven.


title:
Excitons in quantum dot molecules: Coulomb coupling, spin-orbit effects
  and phonon-induced line broadening

abstract:
  Excitonic states and the line shape of optical transitions in coupled quantum
dots (quantum dot molecules) are studied theoretically. For a pair of
electrically tunable, vertically aligned quantum dots we investigate the
coupling between spatially direct and indirect excitons caused by different
mechanisms such as tunnel coupling, Coulomb coupling, coupling due to the
spin-orbit interaction and coupling induced by a structural asymmetry. The
peculiarities of the different types of couplings are reflected in the
appearance of either crossings or avoided crossings between direct and indirect
excitons, the latter ones being directly visible in the absorption spectrum. We
analyze the influence of the phonon environment on the spectrum by calculating
the line shape of the various optical transitions including contributions due
to both pure dephasing and phonon-induced transitions between different exciton
states. The line width enhancement due to phonon-induced transitions is
particularly pronounced in the region of an anticrossing and it strongly
depends on the energy splitting between the two exciton branches.


title: L2-invariants of nonuniform lattices in semisimple Lie groups

abstract:
  We compute L2-invariants of certain nonuniform lattices in semisimple Lie
groups by means of the Borel-Serre compactification of arithmetically defined
locally symmetric spaces. The main results give new estimates for
Novikov-Shubin numbers and vanishing L2-torsion for lattices in groups with
even deficiency. We discuss applications to Gromov's Zero-in-the-Spectrum
Conjecture as well as to a proportionality conjecture for the L2-torsion of
measure equivalent groups.


title:
Thermal phase transitions in a honeycomb lattice gas with three-body
  interactions

abstract:
  We study the thermal phase transitions in a classical (hard-core) lattice gas
model with nearest-neighbor three-body interactions on the honeycomb lattice,
based on parallel tempering Monte Carlo simulations. This system realizes
incompressible low-temperature phases at fractional fillings of 9/16, 5/8 and
3/4 that were identified in a previous study of a related quantum model. In
particular, both the 9/16 and the 5/8 phase exhibit an extensive ground state
degeneracy reflecting the frustrated nature of the three-body interactions on
the honeycomb lattice. The thermal melting of the 9/16 phase is found to be a
first-order, discontinuous phase transition. On the other hand, from the
thermodynamic behavior we obtain indications for a four-states Potts-model
thermal transition out of the 5/8 phase. Employing an exact mapping to a
hard-core dimer model on an embedded honeycomb super-lattice, we find that this
thermal Potts-model transition relates to the selection of one out of four
extensive sectors within the low-energy manifold of the 5/8 phase.


title: Cartier Crystals

abstract:
  Building on our previous work "Cartier modules: finiteness results" we start
in this manuscript an in depth study of the derived category of Cartier modules
and the cohomological operations which are defined on them. After localizing at
the sub-category of locally nilpotent objects we show that for a morphism
essentially of finite type $f$ the operations $Rf_*$ and $f^!$ are defined for
Cartier crystals. We show that, if $f$ is of finite type (but not necessarily
proper) $Rf_*$ preserves coherent cohomology (up to nilpotence) and that $f^!$
has bounded cohomological dimension. In a sequel we will explain how
Grothendieck-Serre Duality relates our theory of Cartier Crystals to the theory
of $\tau$-crystals as developed by Pink and the second author.


title:
The Lockman Hole project: gas and galaxy properties from a stacking
  experiment

abstract:
  We perform an HI stacking analysis to study the relation between HI content
and optical/radio/IR properties of galaxies located in the Lockman Hole area.
In the redshift range covered by the observations (up to z = 0.09), we use the
SDSS to separate galaxies with different optical characteristics, and we
exploit the deep L-band radio continuum image (with noise 11 \mu Jy/beam) to
identify galaxies with radio continuum emission. Infrared properties are
extracted from the Spitzer catalog. We detect HI in blue galaxies, but HI is
also detected in the group of red galaxies - albeit with smaller amounts than
for the blue sample. We identify a group of optically inactive galaxies with
early-type morphology that does not reveal any HI and ionized gas. These
inactive galaxies likely represent the genuine red and dead galaxies depleted
of all gas. Unlike inactive galaxies, HI is detected in red LINER-like objects.
Galaxies with radio continuum counterparts mostly belong to the sub-mJy
population, whose objects are thought to be a mixture of star-forming galaxies
and low-power AGNs. After using several AGN diagnostics, we conclude that the
radio emission in the majority of our sub-mJy radio sources stems from star
formation. LINERs appear to separate into two groups based on IR properties and
HI content. LINERs with a 24 \mu m detection show relatively large amounts of
HI and are also often detected in radio continuum as a result of ongoing star
formation. The LINER galaxies which are not detected at 24 \mu m are more like
the optically inactive galaxies by being depleted of HI gas and having no sign
of star formation. Radio LINERs in the latter group are the best candidates for
hosting low-luminosity radio AGN.


title:
Darboux transformation and multi-dark soliton for N-component coupled
  nonlinear Schr\"odinger equations

abstract:
  In this paper, we obtain a uniform Darboux transformation for multi-component
coupled NLS equations, which can be reduced to all previous presented Darboux
transformation. As a direct application, we derive the single dark soliton and
multi-dark soliton solutions for multi-component coupled NLS with defocusing
case and mixed focusing and defocusing case. Some exact single and two-dark
solitons of three-component NLS equation are shown by plotting the picture.


title:
Dynamical Process of Liner Implosion in the Electromagnetic Flux
  Compression for Ultra-high Magnetic Fields

abstract:
  The spatial distribution of magnetic fields that are generated by the
electromagnetic flux compression technique is investigated, with emphasis on
the dynamical processes of an imploding liner. By comparing with the results of
computer simulations, we found that the non-uniform implosion of a liner is
important in order to explain the magnetic field's distribution during the
liner's implosion. In addition, our results suggest that the initial inwards
compressing spool-like motion of the liner subsequently turns out to be
outwards stretching barrel-like motion along the magnetic field axis.


title: Imaging diagnostics for transitional discs

abstract:
  Transitional discs are a special type of protoplanetary discs where planet
formation is thought to be taking place. These objects feature characteristic
inner cavities and/or gaps of a few tens of AUs in the sub-millimitre images of
the disc. This signature suggests a localised depletion of matter in the disc
that could be caused by planet formation processes. However, recent
observations have revealed differences in the structures imaged at different
wavelengths in some of these discs. In this paper, we aim to explain these
observational differences using self-consistent physical 2-D hydrodynamical and
dust evolution models of such objects, assuming their morphology is indeed
generated by the presence of a planet. We use these models to derive the
distribution of gas and dust in a theoretical planet-hosting disc, for various
planet masses and orbital separations. We then simulate observations of the
emitted and scattered light from these models with VLT/SPHERE ZIMPOL,
Subaru/HiCIAO, VLT/VISIR and ALMA. We do this by first computing the full
resolution images of the models at different wavelengths, and then simulating
the observations accounting for the characteristics of each particular
instrument. The presence of the planet generates pressure bumps in the gas
distribution of the disc whose characteristics strongly depend on the planet
mass and position. These bumps cause large grains to accumulate while small
grains are allowed into inner regions. This spatial differentiation of the
grain sizes explains the differences in the observations since different
wavelengths and observing techniques trace different parts of the dust size
distribution. Based on this effect, we conclude that the combination of
visible/near-infrared polarimetric and sub-mm images is the best strategy to
constrain the properties of the unseen planet responsible for the disc
structure.


title: A generalization of Alternating Sign Matrices

abstract:
  In alternating sign matrices the first and last nonzero entry in each row and
column is specified to be +1.
  Such matrices always exist. We investigate a generalization by specifying
independently the sign of the first and last nonzero entry in each row and
column to be either a +1 or a -1. We determine necessary and sufficient
conditions for such matrices to exist.


title:
Weak localization and Berry flux in topological crystalline insulators
  with a quadratic surface spectrum

abstract:
  The paper examines weak localization (WL) of surface states with a quadratic
band crossing in topological crystalline insulators. It is shown that the
topology of the quadratic band crossing point dictates the negative sign of the
WL conductivity correction. For the surface states with broken time-reversal
symmetry, an explicit dependence of the WL conductivity on the band Berry flux
is obtained and analyzed for different carrier-density regimes and types of the
band structure (normal or inverted). These results suggest a way to detect the
band Berry flux through WL measurements.


title: Quasi-bound states and Fano effect in T-shaped graphene nanoribbons

abstract:
  We study the quasi-bound state and the transport properties in the T-shaped
graphene nanoribbon consisting of a metallic armchair-edge ribbon connecting to
a zigzag-edge sidearm. We systematically study the condition under which there
are quasi-bound states in the system for a wide range of the system size. It is
found that when the width of the sidearm is about half of the width of the
armchair leads, there is a quasi-bound state trapped at the intersection of the
T-shape structure. The quasi-bound states are truly localized in the sidearm
but have small continuum components in the armchair leads. The quasi-bound
states have strong effect on the transport between the armchair leads through
the Fano effect, but do not affect the transport between the armchair lead and
the sidearm.


title: Proceedings Machines, Computations and Universality 2013

abstract:
  This volume contains the papers presented at the 6th conference on Machines,
Computations and Universality (MCU 2013). MCU 2013 was held in Zurich,
Switzerland, September 9-11, 2013. The MCU series began in Paris in 1995 and
has since been concerned with gaining a deeper understanding of computation
through the study of models of general purpose computation. This volume
continues in this tradition and includes new simple universal models of
computation, and other results that clarify the relationships between models.


title:
Highly effective and isotropic pinning in epitaxial Fe(Se,Te) thin films
  grown on CaF2 substrates

abstract:
  We report on the isotropic pinning obtained in epitaxial Fe(Se,Te) thin films
grown on CaF2 (001) substrate. High critical current density values larger than
1 MA/cm2 in self field in liquid helium are reached together with a very weak
dependence on the magnetic field and a complete isotropy. Analysis through
Transmission Electron Microscopy evidences the presence of defects looking like
lattice disorder at a very small scale, between 5 and 20 nm, which are thought
to be responsible for such isotropic behavior in contrast to what observed on
SrTiO3, where defects parallel to the c-axis enhance pinning in that direction


title: alpha-stable densities are HCM for alpha \in ]0,1/4] and [1/3,1/2]

abstract:
  We investigate the problem raised by L. Bondesson, about the hyperbolic
complete monotonicity of $\alpha$-stable densities. We prove that densitites of
subordinators of order $\alpha$ are HCM for $\alpha \in ]0,1/4] \cup
[1/3,1/2]$.


title: Saturated simple and $k$-simple topological graphs

abstract:
  A simple topological graph $G$ is a graph drawn in the plane so that any pair
of edges have at most one point in common, which is either an endpoint or a
proper crossing. $G$ is called saturated if no further edge can be added
without violating this condition. We construct saturated simple topological
graphs with $n$ vertices and $O(n)$ edges. For every $k>1$, we give similar
constructions for $k$-simple topological graphs, that is, for graphs drawn in
the plane so that any two edges have at most $k$ points in common. We show that
in any $k$-simple topological graph, any two independent vertices can be
connected by a curve that crosses each of the original edges at most $2k$
times. Another construction shows that the bound $2k$ cannot be improved.
Several other related problems are also considered.


title: SCUPOL Magnetic Field Analysis

abstract:
  We present an extensive analysis of the 850 microns polarization maps of the
SCUPOL Catalog produced by Matthews et al. (2009), focusing exclusively on the
molecular clouds and star-forming regions. For the sufficiently sampled
regions, we characterize the depolarization properties and the
turbulent-to-mean magnetic field ratio of each region. Similar sets of
parameters are calculated from 2D synthetic maps of dust emission polarization
produced with 3D MHD numerical simulations scaled to the S106, OMC-2/3, W49 and
DR21 molecular clouds polarization maps. For these specific regions the
turbulent MHD regimes retrieved from the simulations, as described by the
turbulent Alfv\`en and sonic Mach numbers, are consistent within a factor 1 to
2 with the values of the same turbulent regimes estimated from the analysis of
Zeeman measurements data provided by Crutcher (1999). Constraints on the values
of the inclination angle of the mean magnetic field with respect to the LOS are
also given. The values obtained from the comparison of the simulations with the
SCUPOL data are consistent with the estimates made by use of two different
observational methods provided by other authors. Our main conclusion is that
simple ideal, isothermal and non-selfgraviting MHD simulations are sufficient
to describe the large scale observed physical properties of the envelopes of
this set of regions.


title: Structural anisotropy of directionally dried colloids

abstract:
  Aqueous colloidal dispersions of silica particles become anisotropic when
they are dried through evaporation. This anisotropy is generated by a uniaxial
strain of the liquid dispersions as they are compressed by the flow of water
toward a solidification front. Part of the strain produced by the compression
is relaxed, and part of it is stored and transferred to the solid. This stored
elastic strain has consequences for the properties of the solid, where it may
facilitate the growth of shear bands, and generate birefringence.


title: xDGP: A Dynamic Graph Processing System with Adaptive Partitioning

abstract:
  Many real-world systems, such as social networks, rely on mining efficiently
large graphs, with hundreds of millions of vertices and edges. This volume of
information requires partitioning the graph across multiple nodes in a
distributed system. This has a deep effect on performance, as traversing edges
cut between partitions incurs a significant performance penalty due to the cost
of communication. Thus, several systems in the literature have attempted to
improve computational performance by enhancing graph partitioning, but they do
not support another characteristic of real-world graphs: graphs are inherently
dynamic, their topology evolves continuously, and subsequently the optimum
partitioning also changes over time.
  In this work, we present the first system that dynamically repartitions
massive graphs to adapt to structural changes. The system optimises graph
partitioning to prevent performance degradation without using data replication.
The system adopts an iterative vertex migration algorithm that relies on local
information only, making complex coordination unnecessary. We show how the
improvement in graph partitioning reduces execution time by over 50%, while
adapting the partitioning to a large number of changes to the graph in three
real-world scenarios.


title: On Area Comparison and Rigidity Involving the Scalar Curvature

abstract:
  We prove a splitting theorem for Riemannian n-manifolds with scalar curvature
bounded below by a negative constant and containing certain area-minimising
hypersurfaces (Theorem 3). Thus we generalise [25,Theorem 3] by Nunes. This
splitting result follows from an area comparison theorem for hypersurfaces with
non-positive Sigma-constant (Theorem 4) that generalises [23, Theorem 2].
Finally, we will address the optimality of these comparison and splitting
results by explicitly constructing several examples.


title: Efficient Enumeration of Chordless Cycles

abstract:
  In a finite undirected simple graph, a {\it chordless cycle} is an induced
subgraph which is a cycle. We propose two algorithms to enumerate all chordless
cycles of such a graph. Compared to other similar algorithms, the proposed
algorithms have the advantage of finding each chordless cycle only once. To
ensure this, we introduced the concepts of vertex labeling and initial valid
vertex triplet. To guarantee that the expansion of a given chordless path will
always lead to a chordless cycle, we use a breadth-first search in a subgraph
obtained by the elimination of many of the vertices from the original graph.
The resulting algorithm has time complexity $\mathcal{O}(n + m)$ in the output
size, where $n$ is the number of vertices and $m$ is the number of edges.


title:
Criticality, factorization and long-range correlations in the
  anisotropic XY-model

abstract:
  We study the long-range quantum correlations in the anisotropic XY-model. By
first examining the thermodynamic limit we show that employing the quantum
discord as a figure of merit allows one to capture the main features of the
model at zero temperature. Further, by considering suitably large site
separations we find that these correlations obey a simple scaling behavior for
finite temperatures, allowing for efficient estimation of the critical point.
We also address ground-state factorization of this model by explicitly
considering finite size systems, showing its relation to the energy spectrum
and explaining the persistence of the phenomenon at finite temperatures.
Finally, we compute the fidelity between finite and infinite systems in order
to show that remarkably small system sizes can closely approximate the
thermodynamic limit.


title:
The influence of the Rashba spin-orbit coupling on the two-dimensional
  electron-hole system and magnetoexcitons

abstract:
  In the review article the influence of the Rashba spin-orbit coupling on the
two-dimensional electrons and holes in a strong perpendicular magnetic field is
described in Landau gauge using the spinor-type two-component wave functions
with different numbers of the Landau quantization levels in different spin
projections, their difference being determined by the order of the chirality
terms. In this representation the two-particle integral operators such as the
electron and hole densities ${{\hat{\rho}}_{e}}(\vec{Q})$, and
${{\hat{\rho}}_{h}}(\vec{Q})$ as well as the magnetoexciton creation and
annihilation operators $\hat{\Psi}_{ex}^{\dagger}({{F}_{n}},\vec{k})$ and
$\hat{\Psi}_{ex}^{{}}({{F}_{n}},\vec{k})$ in different combinations ${{F}_{n}}$
of the electron and hole spinor states were introduced. On this base the
Hamiltonians of the Coulomb electron-electron and electron-radiation
interactions were deduced. The properties of the magnetoexcitons in these
conditions were discussed.


title: On the spectral and homological dimension of k-Minkowski space

abstract:
  We extend the construction of a spectral triple for k-Minkowski space,
previously given for the two-dimensional case, to the general n-dimensional
case. This takes into account the modular group naturally arising from the
symmetries of the geometry, and requires the use of notions that have been
recently developed in the frameworks of twisted and modular spectral triples.
First we compute the spectral dimension, using an appropriate weight, and show
that in general it coincides with the classical one. We also study the
classical limit and the analytic continuation of the associated zeta function.
Then we compare this notion of dimension with the one coming from homology. To
this end, we compute the twisted Hochschild dimension of the universal
enveloping algebra underlying k-Minkowski space. The result is that twisting
avoids the dimension drop, similarly to other examples coming from quantum
groups. In particular, the simplest such twist is given by the inverse of the
modular group mentioned above.


title: Can the degeneracies in the gravity sector be broken?

abstract:
  It has been long known that by appropriately modifying gravity one can always
reproduce the expansion history of any dark energy model, e.g. the
$\Lambda$CDM. This degeneracy cannot be broken with geometric probes like the
Type Ia supernovae, the cosmic microwave background or the baryon acoustic
oscillations since they are based on the measurement of distances and scales
and therefore require the expansion history $H(z)$, so one may only hope to
break this degeneracy by using dynamic probes like the growth rate data that
track the matter density perturbations. We demonstrate that breaking this
degeneracy is not currently possible by explicitly constructing $f(R)$, $f(G)$
and $f(T)$ theories that mimic exactly the $\Lambda$CDM model at the background
level and confronting them against the latest observational cosmological data.
We also determine the necessary improvement in the growth rate data in order to
discriminate these theories from $\Lambda$CDM. We found that at least a
threefold improvement is necessary, something which will be possible with a
survey like Euclid.


title:
Unexpected colloid-like supernatant from liquid-phase ball-milling
  graphite using miscible solutions as solvents: a failure analysis

abstract:
  Ball-milling graphite was conducted in miscible solutions with the purpose to
exfoliate graphene. Colloid-like stable supernatants were unexpectedly
obtained. Followed were the characterizations with Scanning electronic
microscopy, Thermogravimetric analysis, X-ray diffraction and Elemental
dispersive X-ray mapping to recognize them. As a result, strongly against the
initial judgments, the components of colloid were mainly impurities of mixture
of zirconia, silicate and yttrium oxide, other than nano-graphite.


title: Snowmass Energy Frontier Simulations

abstract:
  This document describes the simulation framework used in the Snowmass Energy
Frontier studies for future Hadron Colliders. An overview of event generation
with {\sc Madgraph}5 along with parton shower and hadronization with {\sc
Pythia}6 is followed by a detailed description of pile-up and detector
simulation with {\sc Delphes}3. Details of event generation are included in a
companion paper cited within this paper. The input parametrization is chosen to
reflect the best object performance expected from the future ATLAS and CMS
experiments; this is referred to as the "Combined Snowmass Detector". We
perform simulations of $pp$ interactions at center-of-mass energies $\sqrt{s}=$
14, 33, and 100 TeV with 0, 50, and 140 additional $pp$ pile-up interactions.
The object performance with multi-TeV $pp$ collisions are studied for the first
time using large pile-up interactions.


title: Partial Multipartite Entanglement in the Matrix Product State Formalism

abstract:
  We present a method to apply the well-known matrix product state (MPS)
formalism to partially separable states in solid state systems. The
computational effort of our method is equal to the effort of the standard
density matrix renormalisation group (DMRG) algorithm. Consequently, it is
applicable to all usually considered condensed matter systems where the DMRG
algorithm is successful. We also show in exemplary cases, that polymerisation
properties of ground states are closely connected to properties of partial
separability, even if the ground state itself is not partially separable.


title:
Progress towards an electro-optical simulator for space based, long arms
  interferometers

abstract:
  We report the progress in the realization of an electronic / optical
simulator for space based, long arm interferometry and its application to the
eLISA mission. The goal of this work is to generate realistic optics and
electronics signals, especially simulating realistic propagation delays. The
first measurements and characterization of this experiment are also presented.
With the present configuration a modest $10^6$ noise reduction factor has been
achieved using the Time Delay Interferometry algorithm. However, the principle
of the experiment has been validated and further work is ongoing to identify
the noise sources and optimize the apparatus.


title:
Hierarchical equations of motion for impurity solver in dynamical
  mean-field theory

abstract:
  A nonperturbative quantum impurity solver is proposed based on a formally
exact hierarchical equations of motion (HEOM) formalism for open quantum
systems. It leads to quantitatively accurate evaluation of physical properties
of strongly correlated electronic systems, in the framework of dynamical
mean-field theory (DMFT). The HEOM method is also numerically convenient to
achieve the same level of accuracy as that using the state-of-the-art numerical
renormalization group impurity solver at finite temperatures. The practicality
of the novel HEOM+DMFT method is demonstrated by its applications to the
Hubbard models with Bethe and hypercubic lattice structures. We investigate the
metal-insulator transition phenomena, and address the effects of temperature on
the properties of strongly correlated lattice systems.


title: Cluster Glasses of Semiflexible Ring Polymers

abstract:
  We present computer simulations of concentrated solutions of unknotted
nonconcatenated semiflexible ring polymers. Unlike in their flexible
counterparts, shrinking involves a strong energetic penalty, favoring
interpenetration and clustering of the rings. We investigate the slow dynamics
of the centers-of-mass of the rings in the amorphous cluster phase, consisting
of disordered columns of oblate rings penetrated by bundles of prolate ones.
Scattering functions reveal a striking decoupling of self- and collective
motions. Correlations between centers-of-mass exhibit slow relaxation, as
expected for an incipient glass transition, indicating the dynamic arrest of
the cluster positions. However, self-correlations decay at much shorter time
scales. This feature is a manifestation of the fast, continuous exchange and
diffusion of the individual rings over the matrix of clusters. Our results
reveal a novel scenario of glass-formation in a simple monodisperse system,
characterized by self-collective decoupling, soft caging and mild dynamic
heterogeneity.


title: Jet-induced 2-D crater formation with horizontal symmetry breaking

abstract:
  We investigate the formation of a crater in a 2-D bed of granular material by
a jet of impinging gas, motivated by the problem of a retrograde rocket landing
on a planetary surface. The crater is characterized in terms of depth and shape
as it evolves, as well as by the horizontal position of the bottom of the
crater. The crater tends to grow logarithmically in time, a result which is
common in related experiments. We also observe a horizontal symmetry breaking
at certain well-defined conditions which, as we will demonstrate, could be of
considerable practical concern for lunar or planetary landers. We present data
on the evolution of these asymmetric states and attempt to give insights into
the mechanism behind the symmetry-breaking bifurcation.


title:
One 4-Twist Helix Snake to Maintain Polarization in 8-120 GeV Proton
  Rings

abstract:
  Solenoid Siberian snakes have successfully maintained polarization in
particle rings below 1 GeV, but never in multi-GeV rings because the Lorentz
contraction of a solenoid's integral B dl would require impractically long
high-field solenoids. High energy rings, such as Brookhaven's 255 GeV
Relativistic Heavy Ion Collider (RHIC), use only odd multiples of pairs of
transverse B-field Siberian snakes directly opposite each other. When it became
impractical to use a pair of Siberian Snakes in Fermilab's 120 GeV Main
Injector, we searched for a new type of single Siberian snake, which should
overcome all depolarizing resonances in the 8.9 - 120 GeV range. We found that
one snake made of one 4-twist helix and 2 short dipoles could maintain the
polarization. This snake design might also be used at other rings, such as
Japan's 30 GeV J-PARC, the 12 - 24 GeV NICA proton-deuteron collider at
JINR-Dubna, and perhaps RHIC's injector, the 25 GeV AGS.


title:
Nonlinear Muckenhoupt-Wheeden type bounds on Reifenberg flat domains,
  with applications to quasilinear Riccati type equations

abstract:
  A weighted norm inequality of Muckenhoupt-Wheeden type is obtained for
gradients of solutions to a class of quasilinear equations with measure data on
Reifenberg flat domains. This essentially leads to a resolution of an existence
problem for quasilinear Riccati type equations with a gradient source term of
arbitrary power law growth.


title: Comment on "Ratchet universality in the presence of thermal noise"

abstract:
  A recent paper [Phys. Rev. E 87, 062114 (2013)] presents numerical
simulations on a system exhibiting directed ratchet transport of a driven
overdamped Brownian particle subjected to a spatially periodic, symmetric
potential. The authors claim that their simulations prove the existence of a
universal waveform of the external force which optimally enhances directed
transport, hence confirming the validity of a previous conjecture put forward
by one of them in the limit of vanishing noise intensity. With minor
corrections due to noise, the conjecture holds even in the presence of noise,
according to the authors. On the basis of their results the authors claim that
all previous theories, which predict a different optimal force waveform, are
incorrect. In this comment we provide sufficient numerical evidence showing
that there is no such universal force waveform and that the evidence obtained
by the authors otherwise is due to a fortunate choice of the parameters. Our
simulations also suggest that previous theories correctly predict the shape of
the optimal waveform within their validity regime, namely when the forcing is
weak. On the contrary, the aforementioned conjecture is shown to be wrong.


title:
Statistiques et visibilit\'e des biblioth\`eques num\'eriques : quelles
  strat\'egies de diffusion ?

abstract:
  We compared statistics of major digital libraries and we tried to see if
there is a relationship between the volume of digital libraries and online
visibility of each digitized document. Finally, we analyzed the consequences of
the diffusion strategies of French digital libraries. The statistics were
obtained by survey, gray literature, alexa.com, and Google Trends.


title: On Quantum Contributions to Black Hole Growth

abstract:
  The effects of Wheeler's quantum foam on black hole growth are explored from
an astrophysical perspective. Quantum fluctuations in the form of mini (10^-5
g) black holes can couple to macroscopic black holes and allow the latter to
grow exponentially in mass on a time scale of ~10^9 years. Consequently,
supermassive black holes can acquire a lot of their mass through these quantum
contributions over the life time of the universe. This alleviates the need for
very efficient forms of baryonic matter accretion more recent than a redshift
z~6. Sgr A* in the Milky Way center is a candidate to verify this quantum
space-time effect, with a predicted mass growth rate of 4x10^-3 Mo yr^-1. A few
comments on the possibility and consequences of dark matter as quantum grown
black holes are made, with a big crunch fate of the universe.


title: Quantization of Planck's Constant

abstract:
  This paper is about the role of Planck's constant, $\hbar$, in the geometric
quantization of Poisson manifolds using symplectic groupoids. In order to
construct a strict deformation quantization of a given Poisson manifold, one
can use all possible rescalings of the Poisson structure, which can be combined
into a single "Heisenberg-Poisson" manifold. The new coordinate on this
manifold is identified with $\hbar$. I present an explicit construction for a
symplectic groupoid integrating a Heisenberg-Poisson manifold and discuss its
geometric quantization. I show that in cases where $\hbar$ cannot take
arbitrary values, this is enforced by Bohr-Sommerfeld conditions in geometric
quantization.
  A Heisenberg-Poisson manifold is defined by linearly rescaling the Poisson
structure, so I also discuss nonlinear variations and give an example of
quantization of a nonintegrable Poisson manifold using a presymplectic
groupoid.
  In appendices, I construct symplectic groupoids integrating a more general
class of Heisenberg-Poisson manifolds constructed from Jacobi manifolds and
discuss the parabolic tangent groupoid.


title:
Strongly enhanced pair production in combined high- and low-frequency
  laser fields

abstract:
  Production of particle-antiparticle pairs by a high-energy probe photon
propagating through a high-intensity laser field is considered in the
nonperturbative interaction regime. The laser field consists of a strong
low-frequency and a weak high-frequency component. While for each component
alone photoproduction of pairs is strongly suppressed, we show that their
combination can largely amplify the pair production probability by facilitating
to bridge the energetic barrier of the process. Our predictions can be tested
by utilizing presently available high-intensity laser devices.


title: Automorphisms of Cuntz-Krieger algebras

abstract:
  We prove that the natural homomorphism from Kirchberg's ideal-related
KK-theory, KKE(e, e'), with one specified ideal, into Hom_{\Lambda}
(\underline{K}_{E} (e), \underline{K}_{E} (e')) is an isomorphism for all
extensions e and e' of separable, nuclear C*-algebras in the bootstrap category
N with the K-groups of the associated cyclic six term exact sequence being
finitely generated, having zero exponential map and with the K_{1}-groups of
the quotients being free abelian groups.
  This class includes all Cuntz-Krieger algebras with exactly one non-trivial
ideal. Combining our results with the results of Kirchberg, we classify
automorphisms of the stabilized purely infinite Cuntz-Krieger algebras with
exactly one non-trivial ideal modulo asymptotically unitary equivalence. We
also get a classification result modulo approximately unitary equivalence.
  The results in this paper also apply to certain graph algebras.


title: The Ambiguous Class Number Formula Revisited

abstract: We will give a simple proof of the ambiguous class number formula.


title: On a class of squarefree monomial ideals of linear type

abstract:
  In a recent work, Fouli and Lin generalized a Villarreal's result and showed
that if each connected components of the line graph of a squarefree monomial
ideal contains at most a unique odd cycle, then this ideal is of linear type.
In this short note, we reprove this result with Villarreal's original ideas
together with a method of Conca and De Negri. We also propose a class of
squarefree monomial ideals of linear type.


title: Orbits and masses in the young triple system TWA 5

abstract:
  We aim to improve the orbital elements and determine the individual masses of
the components in the triple system TWA 5.
  Five new relative astrometric positions in the H band were recorded with the
adaptive optics system at the Very Large Telescope (VLT). We combine them with
data from the literature and a measurement in the Ks band. We derive an
improved fit for the orbit of TWA 5Aa-b around each other. Furthermore, we use
the third component, TWA 5B, as an astrometric reference to determine the
motion of Aa and Ab around their center of mass and compute their mass ratio.
  We find an orbital period of 6.03+/-0.01 years and a semi-major axis of
63.7+/-0.2 mas (3.2+/-0.1 AU). With the trigonometric distance of 50.1+/-1.8
pc, this yields a system mass of 0.9+/-0.1 Msun, where the error is dominated
by the error of the distance. The dynamical mass agrees with the system mass
predicted by a number of theoretical models if we assume that TWA5 is at the
young end of the age range of the TW Hydrae association.
  We find a mass ratio of M_Ab / M_Aa = 1.3 +0.6/-0.4, where the less luminous
component Ab is more massive. This result is likely to be a consequence of the
large uncertainties due to the limited orbital coverage of the observations.


title: B-physics with $N_f=2$ Wilson fermions

abstract:
  We report the final results of the ALPHA collaboration for some B-physics
observables: $f_B$, $f_{B_s}$ and $m_b$. We employ CLS configurations with 2
flavors of $O(a)$ improved Wilson fermions in the sea and pion masses ranging
down to 190 MeV. The b-quark is treated in HQET to order $1/m_b$. The
renormalization, the matching and the improvement were performed
non-perturbatively, and three lattice spacings reaching $a=0.048$ fm are used
in the continuum extrapolation.


title:
Splashing phenomena of room temperature liquid metal droplet striking on
  the pool of the same liquid under ambient air environment

abstract:
  In this article, the fluid dynamics of room temperature liquid metal (RTLM)
droplet impacting onto a pool of the same liquid in ambient air was
investigated. A series of experiments were conducted in order to disclose the
influence of the oxidation effect on the impact dynamics. The droplet shape and
impact phenomenology were recorded with the aid of a high-speed digital camera.
The impact energy stored in the splash structures was estimated via a
theoretical model and several morphological parameters obtained from
instantaneous images of the splash. It was observed that the droplet shape and
the splashing morphology of RTLM were drastically different from those of
water, so was the impact dynamics between room temperature LM pool and high
temperature LM pool. The energy analysis disclosed that the height of the jet
is highly sensitive to the viscosity of the fluid, which is subjected to the
oxidation effect and temperature effect simultaneously, and thus perfectly
explained the phenomena. These basic findings are important for the application
of RTLM in a series of newly emerging technologies such as liquid metal based
spray cooling, ink-jet printed electronics, interface material painting and
coating, metallurgy, and 3D packages, etc.

categories: physics.flu-dyn cond-mat.mtrl-sci cond-mat.soft physics.ins-det


title:
Physics of Rheologically-Enhanced Propulsion: Different Strokes in
  Generalized Stokes

abstract:
  Shear-thinning is an important rheological property of many biological
fluids, such as mucus, whereby the apparent viscosity of the fluid decreases
with shear. Certain microscopic swimmers have been shown to progress more
rapidly through shear-thinning fluids, but is this behavior generic to all
microscopic swimmers, and what are the physics through which shear-thinning
rheology affects a swimmer's propulsion? We examine swimmers employing
prescribed stroke kinematics in two-dimensional, inertialess Carreau fluid:
shear-thinning "Generalized Stokes" flow. Swimmers are modeled, using the
method of femlets, by a set of immersed, regularized forces. The equations
governing the fluid dynamics are then discretized over a body-fitted mesh and
solved with the finite element method. We analyze the locomotion of three
distinct classes of microswimmer: (1) conceptual swimmers comprising sliding
spheres employing both one- and two-dimensional strokes, (2) slip-velocity
envelope models of ciliates commonly referred to as "squirmers" and (3)
monoflagellate pushers, such as sperm. We find that morphologically identical
swimmers with different strokes may swim either faster or slower in
shear-thinning fluids than in Newtonian fluids. We explain this kinematic
sensitivity by considering differences in the viscosity of the fluid
surrounding propulsive and payload elements of the swimmer, and using this
insight suggest two reciprocal sliding sphere swimmers which violate Purcell's
Scallop theorem in shear-thinning fluids. We also show that an increased flow
decay rate arising from shear-thinning rheology is associated with a reduction
in the swimming speed of slip-velocity squirmers. For sperm-like swimmers, a
gradient of thick to thin fluid along the flagellum alters the force it exerts
upon the fluid, flattening trajectories and increasing instantaneous swimming
speed.

categories: physics.flu-dyn cond-mat.soft physics.bio-ph q-bio.OT


title:
Modelling the Fluid Mechanics of Cilia and Flagella in Reproduction and
  Development

abstract:
  Cilia and flagella are actively bending slender organelles, performing
functions such as motility, feeding and embryonic symmetry breaking. We review
the mechanics of viscous-dominated microscale flow, including time-reversal
symmetry, drag anisotropy of slender bodies, and wall effects. We focus on the
fundamental force singularity, higher order multipoles, and the method of
images, providing physical insight and forming a basis for computational
approaches. Two biological problems are then considered in more detail: (1)
left-right symmetry breaking flow in the node, a microscopic structure in
developing vertebrate embryos, and (2) motility of microswimmers through
non-Newtonian fluids. Our model of the embryonic node reveals how particle
transport associated with morphogenesis is modulated by the gradual emergence
of cilium posterior tilt. Our model of swimming makes use of force
distributions within a body-conforming finite element framework, allowing the
solution of nonlinear inertialess Carreau flow. We find that a three-sphere
model swimmer and a model sperm are similarly affected by shear-thinning; in
both cases swimming due to a prescribed beat is enhanced by shear-thinning,
with optimal Deborah number around 0.8. The sperm exhibits an almost perfect
linear relationship between velocity and the logarithm of the ratio of zero to
infinite shear viscosity, with shear-thickening hindering cell progress.

categories: q-bio.QM cond-mat.soft physics.bio-ph physics.flu-dyn


title:
Searching for Terrestrial Planets Orbiting in the Habitable Zone of
  Ultra-Cool Stars and Brown Dwarfs

abstract:
  We propose to use Kepler in 2-wheel mode to conduct a detailed search for
Earth-sized planets orbiting ultra-cool stars and brown dwarfs (spectral types
from M7 to L3). This population of objects presents several advantages for
exoplanet surveys. First, ultra-cool stars and brown dwarfs are small and thus
result in favorable planet-to-star area ratios. Second, because of their low
effective temperature, the inner edge of their habitable zone is extremely
close (2 to 3 days only). Third, our targets are bright at infrared
wavelengths, which will enable detailed follow-up studies. Our program
therefore represents a unique opportunity to find a transiting Earth-size
exoplanet for which atmospheric features (including biosignatures) could be
detected with near-to-come facilities such as JWST. Such exoplanet has not been
discovered yet. Kepler in 2-wheel mode provides the required stability and
photometric precision to make this survey successful. Our initial target sample
includes 60 ultra-cool stars and brown dwarfs from which we expect to detect at
least one transiting planet. We propose to monitor each source for 4 days,
resulting in a total program duration of ~240 days.


title: Weyl Semimetal in the Strong Coulomb Interaction Limit

abstract:
  We study the effects of strong $1/r$ long-range Coulomb interactions in a
Weyl semimetal. We consider a three-dimensional (3D) Dirac fermion system on a
lattice with a time-reversal symmetry breaking term, and take into account
$1/r$ long-range Coulomb interactions between the bulk electrons. This model is
regarded as the case where magnetic impurities are doped into the bulk of a 3D
topological insulator. With the use of the strong coupling expansion of the
lattice gauge theory and the mean-field approximation, we analyze the system
from the strong coupling limit. It is shown that parity symmetry of the system
is spontaneously broken in the strong coupling limit, and a different type of
the Weyl semimetal, in which time-reversal and parity symmetries are broken,
appears in the strong coupling limit. A possible global phase diagram of a
correlated Weyl semimetal is presented.

categories: cond-mat.str-el cond-mat.mes-hall hep-lat hep-ph


title: Boosting in Location Space

abstract:
  The goal of object detection is to find objects in an image. An object
detector accepts an image and produces a list of locations as $(x,y)$ pairs.
Here we introduce a new concept: {\bf location-based boosting}. Location-based
boosting differs from previous boosting algorithms because it optimizes a new
spatial loss function to combine object detectors, each of which may have
marginal performance, into a single, more accurate object detector. A
structured representation of object locations as a list of $(x,y)$ pairs is a
more natural domain for object detection than the spatially unstructured
representation produced by classifiers. Furthermore, this formulation allows us
to take advantage of the intuition that large areas of the background are
uninteresting and it is not worth expending computational effort on them. This
results in a more scalable algorithm because it does not need to take measures
to prevent the background data from swamping the foreground data such as
subsampling or applying an ad-hoc weighting to the pixels. We first present the
theory of location-based boosting, and then motivate it with empirical results
on a challenging data set.


title:
Using MiniBooNE neutral current elastic cross section results to
  constrain 3+1 sterile neutrino models

abstract:
  The MiniBooNE Neutral Current Elastic (NCEL) cross section results are used
to extract limits in the $\Delta m^{2}-\sin^{2}\vartheta_{\mu s}$ plane for a
3+1 sterile neutrino model with a mass splitting $0.1 \leq \Delta m^{2} \leq
10.0$ eV$^{2}$. GENIE is used with a cross section model close to the one
employed by MiniBooNE to make event rate predictions using simulations on the
MiniBooNE target material CH$_{2}$. The axial mass is a free parameter in all
fits. Sterile modifications to the flux and changes to the cross section in the
simulation relate the two and allow limits to be set on sterile neutrino mixing
using cross section results. The large axial mass problem makes it necessary
for experiments to perform their own axial mass fits, but a prior fit to the
same dataset could mask a sterile oscillation signal if the sterile and cross
section model parameters are not independent. We find that for the NCEL dataset
there are significant correlations between the sterile and cross section model
parameters, making a fit to both models simultaneously necessary to get robust
results. Failure to do this results in stronger than warranted limits on the
sterile parameters. The general problems that the current uncertainty on
charged-current quasi-elastic (CCQE) and NCEL cross sections at MiniBooNE
energies pose for sterile neutrino measurements are discussed.


title:
Ideal quantum glass transitions: many-body localization without quenched
  disorder

abstract:
  We explore the possibility for translationally invariant quantum many-body
systems to undergo a dynamical glass transition, at which ergodicity and
translational invariance break down spontaneously, driven entirely by quantum
effects. In contrast to analogous classical systems, where the existence of
such an ideal glass transition remains a controversial issue, a genuine phase
transition is predicted in the quantum regime. This ideal quantum glass
transition can be regarded as a many-body localization transition due to
self-generated disorder. Despite their lack of thermalization, these
disorder-free quantum glasses do not possess an extensive set of local
conserved operators, unlike what is conjectured for many-body localized systems
with strong quenched disorder.


title: On the interior of (Quantum) Black Holes

abstract:
  Different approaches to quantum gravity conclude that black holes may possess
an inner horizon, in addition to the (quantum corrected) outer `Schwarzschild'
horizon. In this paper we assume the existence of this inner horizon and
explain the physical process that might lead to the tunneling of particles
through it. It is shown that the tunneling would produce a flux of particles
with a spectrum that deviates from the pure thermal one. Under the appropriate
approximation the extremely high temperature of this horizon is calculated for
an improved quantum black hole. It is argued that the flux of particles
tunneled through the horizons affects the dynamics of the black hole interior
leading to an endogenous instability.


title:
Observation of bosonic coalescence and fermionic anti-coalescence with
  indistinguishable photons

abstract:
  The symmetrization postulate asserts that the state of particular species of
particles can only be of one permutation symmetry type: symmetric for bosons
and antisymmetric for fermions. We report some experimental results showing
that pairs of photons indistinguishable by all degrees of freedom can exhibit
not only a bosonic behavior, as expected for photons, but also a surprisingly
sharp fermionic behavior under specific conditions.


title: Higher Order Corrections in Minimal Supergravity Models of Inflation

abstract:
  We study higher order corrections in new minimal supergravity models of a
single scalar field inflation. The gauging in these models leads to a massive
vector multiplet and the D-term potential for the inflaton field with a
coupling g^{2} ~ 10^{-10}. In the de-Higgsed phase with vanishing g^2, the
chiral and vector multiplets are non-interacting, and the potential vanishes.
We present generic manifestly supersymmetric higher order corrections for these
models. In particular, for a supersymmetric gravity model -R+ R^2 we derive
manifestly supersymmetric corrections corresponding to R^n. The dual version
corresponds to a standard supergravity model with a single scalar and a massive
vector. It includes, in addition, higher Maxwell curvature/scalar interaction
terms of the Born-Infeld type and a modified D-term scalar field potential. We
use the dual version of the model to argue that higher order corrections do not
affect the last 60 e-foldings of inflation; for example the \xi R^4 correction
is irrelevant as long as \xi< 10^{24}.


title:
Characterization of high frequency oscillations and EEG frequency
  spectra using the damped-oscillator oscillator detector (DOOD)

abstract:
  Objective: The surgical resection of brain areas with high rates of visually
identified high frequency oscillations (HFOs) on EEG has been correlated with
improved seizure control. However, it can be difficult to distinguish normal
from pathological HFOs, and the visual detection of HFOs is very
time-intensive. An automated algorithm for detecting HFOs and for wide-band
spectral analysis is desirable.
  Methods: The damped-oscillator oscillator detector (DOOD) is adapted for HFO
detection, and tested on recordings from one rat and one human. The rat data
consist of recordings from the hippocampus just prior to induction of status
epilepticus, and again 6 weeks after induction, after the rat is epileptic. The
human data are temporal lobe depth electrode recordings from a patient who
underwent pre-surgical evaluation.
  Results: Sensitivities and positive predictive values are presented which
depend on specifying a threshold value for HFO detection. Wide-band
time-frequency and HFO-associated frequency spectra are also presented. In the
rat data, four high frequency bands are identified at 80-250 Hz, 250-500 Hz,
600-900 Hz and 1000-3000 Hz. The human data was low-passed filtered at 1000 Hz
and showed HFO-associated bands at 15 Hz, 85 Hz, 400 Hz and 700 Hz.
  Conclusion: The DOOD algorithm is capable of high resolution time-frequency
spectra, and it can be adapted to detect HFOs with high positive predictive
value. HFO-associated wide-band data show intricate low-frequency structure.
  Significance: DOOD may ease the labor intensity of HFO detection. DOOD
wide-band analysis may in future help distinguish normal from pathological
HFOs.


title: On Resolutions of Cosmological Singularities in Higher-Spin Gravity

abstract:
  We study the resolution of certain cosmological singularity in the context of
higher-spin three-dimensional gravity. We consider gravity coupled to a spin-3
field realized as Chern-Simons theory with gauge group $SL(3,\mathbb{C})$. In
this context we elaborate and extend a singularity resolution scheme proposed
by Krishnan and Roy. We discuss the resolution of a big-bang singularity in the
case of gravity coupled to a spin-4 field realized as Chern-Simons theory with
gauge group $SL(4,\mathbb{C})$. In all these cases we show the existence of
gauge transformations that do not change the holonomy of the Chern-Simons gauge
potential and lead to metrics without the initial singularity. We argue that
such transformations always exist in the context of gravity coupled to a spin-N
field when described by Chern-Simons with gauge group $SL(N,\mathbb{C})$.


title: Vanishing of self-extensions over symmetric algebras

abstract:
  We study self-extensions of modules over symmetric artin algebras. We show
that non-projective modules with eventually vanishing self-extensions must lie
in AR components of stable type $\mathbb{Z}A_{\infty}$. Moreover, the degree of
the highest non-vanishing self-extension of these modules is determined by
their quasilength. This has implications for the Auslander-Reiten Conjecture
and the Extension Conjecture.


title: Randomness-efficient Curve Samplers

abstract:
  Curve samplers are sampling algorithms that proceed by viewing the domain as
a vector space over a finite field, and randomly picking a low-degree curve in
it as the sample. Curve samplers exhibit a nice property besides the sampling
property: the restriction of low-degree polynomials over the domain to the
sampled curve is still low-degree. This property is often used in combination
with the sampling property and has found many applications, including PCP
constructions, local decoding of codes, and algebraic PRG constructions.
  The randomness complexity of curve samplers is a crucial parameter for its
applications. It is known that (non-explicit) curve samplers using $O(\log
N+\log(1/\delta))$ random bits exist, where $N$ is the domain size and $\delta$
is the confidence error. The question of explicitly constructing
randomness-efficient curve samplers was first raised in \cite{TU06} where they
obtained curve samplers with near-optimal randomness complexity.
  We present an explicit construction of low-degree curve samplers with {\em
optimal} randomness complexity (up to a constant factor), sampling curves of
degree $\left(m\log_q(1/\delta)\right)^{O(1)}$ in $\mathbb{F}_q^m$. Our
construction is a delicate combination of several components, including
extractor machinery, limited independence, iterated sampling, and
list-recoverable codes.


title: Sustainable entanglement production from a quantum field

abstract:
  We propose a protocol by which entanglement can be extracted repeatedly from
a quantum field. In analogy with prior work on entanglement harvesting, we call
this protocol entanglement farming. It consists of successively sending pairs
of unentangled particles through an optical cavity. Using non-perturbative
Gaussian methods, we show that in certain generic circumstances this protocol
drives the cavity field towards a non-thermal metastable state. This state of
the cavity is such that successive pairs of unentangled particles sent through
the cavity will reliably emerge significantly entangled. We calculate
thermodynamic aspects of the harvesting process, such as energies and
entropies, and also the long-term behavior beyond the few-mode approximation.
Significant for possible experimental realizations is the fact that this
entangling fixed point state of the cavity is reached largely independently of
the initial state in which the cavity was prepared. Our results suggest that
reliable entanglement farming on the basis of such a fixed point state should
be possible also in various other experimental settings, namely with the
to-be-entangled particles replaced by arbitrary qudits and with the cavity
replaced by a suitable reservoir system.


title:
Stress concentration near stiff inclusions: validation of rigid
  inclusion model and boundary layers by means of photoelasticity

abstract:
  Photoelasticity is employed to investigate the stress state near stiff
rectangular and rhombohedral inclusions embedded in a 'soft' elastic plate.
Results show that the singular stress field predicted by the linear elastic
solution for the rigid inclusion model can be generated in reality, with great
accuracy, within a material. In particular, experiments: (i.) agree with the
fact that the singularity is lower for obtuse than for acute inclusion angles;
(ii.) show that the singularity is stronger in Mode II than in Mode I
(differently from a notch); (iii.) validate the model of rigid quadrilateral
inclusion; (iv.) for thin inclusions, show the presence of boundary layers
deeply influencing the stress field, so that the limit case of rigid line
inclusion is obtained in strong dependence on the inclusion's shape. The
introduced experimental methodology opens the possibility of enhancing the
design of thin reinforcements and of analyzing complex situations involving
interaction between inclusions and defects.


title:
The size of the X-ray emitting region in SWIFT J2127.4+5654 via a broad
  line region cloud X-ray eclipse

abstract:
  We present results obtained from the time-resolved X-ray spectral analysis of
the Narrow-Line-Seyfert 1 galaxy SWIFT J2127.4+5654 during a ~130 ks XMM-Newton
observation. We reveal large spectral variations, especially during the first
~90 ks of the XMM-Newton exposure. The spectral variability can be attributed
to a partial eclipse of the X-ray source by an intervening low-ionization/cold
absorbing structure (cloud) with column density N_H = 2.0^{+0.2}_{-0.3}e22
cm^-2 which gradually covers and then uncovers the X-ray emitting region with
covering fraction ranging from zero to ~43 per cent. Our analysis enables us to
constrain the size, number density, and location of the absorbing cloud with
good accuracy. We infer a cloud size (diameter) of $D_c < 1.5e13 cm,
corresponding to a density of n_c > 1.5e9 cm^-3 at a distance of R_c > 4.3e16
cm from the central black hole. All of the inferred quantities concur to
identify the absorbing structure with one single cloud associated with the
broad line region of SWIFT J2127.4+5654. We are also able to constrain the
X-ray emitting region size (diameter) to be D_s < 2.3e13 cm which, assuming the
black hole mass estimated from single-epoch optical spectroscopy (1.5e7 M_sun),
translates into D_s < 10.5 gravitational radii (r_g) with larger sizes (in r_g)
being associated with smaller black hole masses, and viceversa. We also confirm
the presence of a relativistically distorted reflection component off the inner
accretion disc giving rise to a broad relativistic Fe K emission line and small
soft excess (small because of the high Galactic column density), supporting the
measurement of an intermediate black hole spin in SWIFT J2127.4+5654 that was
obtained from a previous Suzaku observation.


title: Filling and wetting transitions at grooved substrates

abstract:
  The wetting and filling properties of a fluid adsorbed on a solid grooved
substrate are studied by means of a microscopic density functional theory. The
grooved substrates are modelled using a solid slab, interacting with the fluid
particles via long-range dispersion forces, to which a one-dimensional array of
infinitely long rectangular grooves is sculpted. By investigating the effect of
the groove periodicity and the width of the grooves and the ridges, a rich
variety of different wetting morphologies is found. In particular, we show that
for a saturated ambient gas, the adsorbent can occur in one of four wetting
states characterised by i) empty grooves, ii) filled grooves, iii) a formation
of mesoscopic hemispherical caps iv) a macroscopically wet surface. The
character of the transition between particular regimes, that also extend
off-coexistence, sensitively depends on the model geometry. A temperature at
which the system becomes completely wet is considerably higher than that for a
flat wall.


title:
$\Xi^-$ hyperon and hypernuclear production in the $(K^-,K^+)$ reaction
  on nucleon and nuclei in a field theoretical model

abstract:
  We investigate the production of a cascade hyperon ($\Xi$) and bound $\Xi^-$
hypernuclei in the $(K^-,K^+)$ reaction on proton and nuclear targets,
respectively, within a covariant effective Lagrangian model. The $K^+\Xi^-$
production vertex is described by excitation, propagation and decay of
$\Lambda$ and $\Sigma$ resonance states in the initial collision of a $K^-$
meson with a free or bound proton in the incident channel. The parameters of
the resonance vertices are taken from previous studies and SU(3) symmetry
considerations. The model is able to provide a good description of the
available data on total and differential cross sections for the $p(K^-,
K^+)\Xi^-$ reaction. The same mechanism was used to describe the hypernuclear
production reactions $^{12}$C$(K^-,K^+)^{12}{/!/!/!_{/Xi^-}}$Be and
$^{28}$Si$(K^-,K^+)^{28}{/!/!/!_{\Xi^-}}$Mg, where $\Xi$ bound state spinors
calculated within a phenomenological model have been employed. Both the
elementary and hypernuclear production cross sections are dominated by the
contributions from the $\Lambda$(1520) intermediate resonant state. The beam
momentum dependence of the $0^\circ$ differential cross sections for the
formation of the $\Xi$ hypernuclei is found to be remarkably different from
what has been observed previously in the impulse approximation model
calculations


title: Optical Bistability in a cavity with one moving mirror

abstract:
  We analyze the behaviour of a coherent field driving a single mode optical
cavity with one perfectly reflecting moving mirror and a partially reflecting
fixed mirror, and show that this system's output exhibits optical bistability
due to radiation pressure acting over the moving mirror.


title: NEOKepler: Discovering Near-Earth Objects Using the Kepler Spacecraft

abstract:
  We propose a new Kepler mission, called NEOKepler, that would survey near
Earth's orbit to identify potentially hazardous objects (PHOs). To understand
its surveying power, Kepler's large field of view produces an 'etendue'
(A*Omega) that is 4.5 times larger than the best survey telescope currently in
operation. In this paper, we investigate the feasibility of NEOKepler using a
double "fence post" survey pattern that efficiently detects PHOs. In a
simulated 12-month survey, we estimate that NEOKepler would detect ~150 new
NEOs with absolute magnitudes of less than 21.5, ~50 of which would be new
PHOs. This would increase the annual PHO discovery rate by at least 50% and
improve upon our goal of discovering 90% of PHOs by the end of 2020. Due to its
heliocentric orbit, Kepler would also be sensitive to objects inside Earth's
orbit, discovering more objects in its first year than are currently known to
exist. Understanding this undersampled sub-population of NEOs will reveal new
insights into the actual PHO distribution by further constraining current NEO
models. As an alternative science goal, NEOKepler could employ a different
observing strategy to discover suitable targets for NASA's Asteroid Redirect
Mission.


title:
The characteristic black hole mass resulting from direct collapse in the
  early universe

abstract:
  Black holes of a billion solar masses are observed in the infant universe a
few hundred million years after the Big Bang. The direct collapse of
protogalactic gas clouds in primordial halos with $\rm T_{vir} \geq 10^{4} K$
provides the most promising way to assemble massive black holes. In this study,
we aim to determine the characteristic mass scale of seed black holes and the
time evolution of the accretion rates resulting from the direct collapse model.
We explore the formation of supermassive black holes via cosmological large
eddy simulations (LES) by employing sink particles and following their
evolution for twenty thousand years after the formation of the first sink. As
the resulting protostars were shown to have cool atmospheres in the presence of
strong accretion, we assume here that UV feedback is negligible during this
calculation. We confirm this result in a comparison run without sinks. Our
findings show that black hole seeds with characteristic mass of $\rm 10^{5}
M_{\odot}$ are formed in the presence of strong Lyman Werner flux which leads
to an isothermal collapse. The characteristic mass is a about two times higher
in LES compared to the implicit large eddy simulations (ILES). The accretion
rates increase with time and reach a maximum value of 10 $\rm M_{\odot}/yr$
after $\rm 10^{4}$ years. Our results show that the direct collapse model is
clearly feasible as it provides the expected mass of the seed black holes.


title: Prime ideals and regular sequences of symmetric polynomials

abstract:
  Let S=K[x_1,...,x_n] be a polynomial ring. Denote by $p_a$ the power sum
symmetric polynomial x_1^a+...+x_n^a. We consider the following two questions:
Describe the subsets $A \subset \mathbb{N}$ such that the set of polynomials
$p_a$ with $a \in A$ generate a prime ideal in S or the set of polynomials
$p_a$ with $a \in A$ is a regular sequence in S. We produce a large families of
prime ideals by exploiting Serre's criterion for normality [4, Theorem 18.15]
with the help of arithmetic considerations, vanishing sums of roots of unity
[9]. We also deduce several other results concerning regular sequences of
symmetric polynomials.


title: Gaia FGK Benchmark Stars - Metallicity

abstract:
  To calibrate automatic pipelines that determine atmospheric parameters of
stars, one needs a sample of stars -- ``benchmark stars'' -- with well defined
parameters to be used as a reference We provide a detailed documentation of the
determination of the iron abundance of the 34 FGK-type benchmark stars selected
to be the pillars for calibration of the one billion Gaia stars. They cover a
wide range of temperatures, surface gravities and metallicities. Up to seven
different methods were used to analyze an observed spectral library of high
resolution and high signal-to-noise ratio. The metallicity was determined
assuming a value of effective temperature and surface gravity obtained from
fundamental relations, i.e. these parameters were known a priori independently
from the spectra. We present a set of metallicity values obtained in a
homogeneous way for our sample of Benchmark Stars. In addition to this value,
we provide a detailed documentation of the associated uncertainties. Finally,
we report for the first time a value of the metallicity of the cool giant psi
Phe.


title:
Lattice effects in the quasi-two-dimensional valence-bond-solid Mott
  insulator EtMe$_3$P[Pd(dmit)$_2$]$_2$

abstract:
  The organic charge-transfer salt EtMe$_3$P[Pd(dmit)$_2$]$_2$ is a
quasi-two-dimensional Mott insulator with localized spins $S$ = 1/2 residing on
a distorted triangular lattice. Here we report measurements of the uniaxial
thermal expansion coefficients $\alpha_i$ along the in-plane $i$ = $a$- and
$c$-axis as well as along the out-of-plane $b$-axis for temperatures 1.4\,K
$\leq $T$ \leq$ 200\,K. Particular attention is paid to the lattice effects
around the phase transition at $T_{VBS}$ = 25\,K into a low-temperature
valence-bond-solid phase and the paramagnetic regime above where effects of
short-range antiferromagnetic correlations can be expected. The salient results
of our study include (i) the observation of strongly anisotropic lattice
distortions accompanying the formation of the valence-bond-solid, and (ii) a
distinct maximum in the thermal expansion coefficients in the paramagnetic
regime around 40\,K. Our results demonstrate that upon cooling through
$T_{VBS}$ the in-plane $c$-axis, along which the valence bonds form, contracts
while the second in-plane $a$-axis elongates by the same relative amount.
Surprisingly, the dominant effect is observed for the out-of-plane $b$-axis
which shrinks significantly upon cooling through $T_{VBS}$. The pronounced
anomaly in $\alpha_i$ around 40\,K is attributed to short-range magnetic
correlations. It is argued that the position of this maximum, relative to that
in the magnetic susceptibility around 70\,K, speaks in favor of a more
anisotropic triangular-lattice scenario for this compound than previously
thought.


title: Simplifying the Development, Use and Sustainability of HPC Software

abstract:
  Developing software to undertake complex, compute-intensive scientific
processes requires a challenging combination of both specialist domain
knowledge and software development skills to convert this knowledge into
efficient code. As computational platforms become increasingly heterogeneous
and newer types of platform such as Infrastructure-as-a-Service (IaaS) cloud
computing become more widely accepted for HPC computations, scientists require
more support from computer scientists and resource providers to develop
efficient code and make optimal use of the resources available to them. As part
of the libhpc stage 1 and 2 projects we are developing a framework to provide a
richer means of job specification and efficient execution of complex scientific
software on heterogeneous infrastructure. The use of such frameworks has
implications for the sustainability of scientific software. In this paper we
set out our developing understanding of these challenges based on work carried
out in the libhpc project.


title:
Giant optical nonlocality near the Dirac point in metal-dielectric
  multilayer metamaterials

abstract:
  The giant optical nonlocality near the Dirac point in lossless
metal-dielectric multilayer metamaterials is revealed and investigated through
the analysis of the band structure of the multilayer stack in the
three-dimensional omega-k space, according to the transfer-matrix method with
the optical nonlocal effect. The position of the Dirac point is analytically
located in the omega-k space. It is revealed that the emergence of the Dirac
point is due to the degeneracy of the symmetric and the asymmetric eigenmodes
of the coupled surface plasmon polaritons. The optical nonlocality induced
epsilon-near-zero frequency shift for the multilayer stack compared to the
effective medium is studied. Furthermore, the giant optical nonlocality around
the Dirac point is explored with the iso-frequency contour analysis, while the
beam splitting phenomenon at the Dirac point due to the optical nonlocal effect
is also demonstrated.


title: Multi-Time Equations, Classical and Quantum

abstract:
  Multi-time equations are evolution equations involving several time
variables, one for each particle. Such equations have been considered for the
purpose of making theories manifestly Lorentz invariant. We compare their
status and significance in classical and quantum physics.


title: Local Thermodynamic Equilibrium at Three Levels

abstract:
  We present coordinated formulations of local thermodynamical equilibrium
conditions at three levels, namely the macroscopic one of classical
thermodynamics, the mesoscopic one of hydrodynamical fluctuations and the
microscopic one of quantum statistical mechanics. These conditions are all
expressed in terms of the hydrodynamical variables of the macroscopic picture,
and the quantum statistical ones are shown to imply a local version of the
zeroth law.


title:
Exploiting negative differential resistance in monolayer graphene FETs
  for high voltage gains

abstract:
  Through self-consistent quantum transport simulations, we evaluate the RF
performance of monolayer graphene FETs in the bias region of negative output
differential resistance. We show that, compared to the region of
quasi-saturation, a voltage gain larger than 10 can be obtained, at the cost of
a decrease in the maximum oscillation frequency of about a factor of 1.5--3 and
the need for a careful circuit stabilization.


title:
Finite-range multiplexing enhances quantum key distribution via quantum
  repeaters

abstract:
  Quantum repeaters represent one possible way to achieve long-distance quantum
key distribution. Collins et al. in [Phys. Rev. Lett. 98, 060502 (2007)]
proposed multiplexing as method to increase the repeater rate and to decrease
the requirement in memory coherence time. Motivated by the experimental fact
that long-range connections are practically demanding, in this paper we extend
the original quantum repeater multiplexing protocol to the case of short-range
connection. We derive analytical formulas for the repeater rate and we show
that for short connection lengths it is possible to have most of the benefits
of a full-range multiplexing protocol. Then we incorporate decoherence of
quantum memories and we study the optimal matching for the Bell-state
measurement protocol permitting to minimize memory requirements. Finally, we
calculate the secret key rate and we show that the improvement via finite-range
multiplexing is of the same order of magnitude as via full-range multiplexing.


title:
Effects of Characteristic Length Scales on the Exciton Dynamics in
  Rubrene Single Crystals

abstract:
  As for its inorganic counterparts the future developments in organic
electronics are driven by an advanced device miniaturization. Therefore, the
opto-electronic behavior of up-to-date devices is progressively governed by the
local structural environment. However, there is a lack of organic semiconductor
materials providing access to the fundamental structure-functionality relation,
either due to limitations by their inherent growth or their optical
characteristics. In this work we present a systematic investigation of the
optical states, so-called excitons, and their temporal evolution in the
prototypical organic semiconductor rubrene by means of time and temperature
dependent photoluminescence studies. This material offers the unique
possibility of preparing well-defined morphologies with adjustable degree of
confinement. By this approach we are able to confirm the direct influence on
the temperature dependent optical processes with picosecond resolution already
for a spatial localization of excitation on the \mu m length scale. While in
bulk single crystals the exciton decay dynamics are governed by thermally
activated singlet fission, excitons created in microcrystals are trapped by
dark states localized on the surface and leading to a pronounced enhancement of
their average lifetime. Our results highlight the impact of the local
environment on the excitonic states and their dynamics in organic
semiconductors. With respect to the spatial dimensions of organic thin film
devices, this correlation and the reported effects emerging by the confinement
have to be considered upon further miniaturization and in the development of
innovative device concepts, such as photovoltaic cells based on
triplet-harvesting.


title:
On the application of Good-Turing statistics to quantify convergence of
  biomolecular simulations

abstract:
  Quantifying convergence and sufficient sampling of macromolecular molecular
dynamics simulations is more often than not a source of controversy (and of
various ad hoc solutions) in the field. Clearly, the only reasonable,
consistent and satisfying way to infer convergence (or otherwise) of a
molecular dynamics trajectory must be based on probability theory. Ideally, the
question we would wish to answer is the following : "What is the probability
that a molecular configuration important for the analysis in hand has not yet
been observed ?". Here we propose a method for answering a variant of this
question by using the Good-Turing formalism for frequency estimation of
unobserved species in a sample. Although several approaches may be followed in
order to deal with the problem of discretizing the configurational space, for
this work we use the classical RMSD matrix as a means to answering the
following question: "What is the probability that a molecular configuration
with an RMSD (from all other already observed configurations) higher than a
given threshold has not actually been observed ?". We apply the proposed method
to several different trajectories and show that the procedure appears to be
both computationally stable and internally consistent. A free, open-source
program implementing these ideas is immediately available for download via
public repositories.


title:
Qualitative properties of a nonlinear system involving the $p$-Laplacian
  operator

abstract:
  In this article we consider the nonlinear system involving the $p$-Laplacian
$$\left\{\begin{array}{lc} |u^\prime |^{p-2} u^{\prime \prime} = u^{p-1} v^p&
|v^\prime |^{p-2} v^{\prime \prime} = v^{p-1} u^p&\ {\rm on} \ \R, u\geq 0,
v\geq 0& \end{array}\right.$$ for which we prove symmetry, asymptotic behavior
and non degeneracy properties. This can help to a better understanding to what
happens in the $N$ dimensional case, for which several authors prove a De
Giorgi Type result under some additional growth and monotonicity assumptions.


title: When Backpressure Meets Predictive Scheduling

abstract:
  Motivated by the increasing popularity of learning and predicting human user
behavior in communication and computing systems, in this paper, we investigate
the fundamental benefit of predictive scheduling, i.e., predicting and
pre-serving arrivals, in controlled queueing systems. Based on a lookahead
window prediction model, we first establish a novel equivalence between the
predictive queueing system with a \emph{fully-efficient} scheduling scheme and
an equivalent queueing system without prediction. This connection allows us to
analytically demonstrate that predictive scheduling necessarily improves system
delay performance and can drive it to zero with increasing prediction power. We
then propose the \textsf{Predictive Backpressure (PBP)} algorithm for achieving
optimal utility performance in such predictive systems. \textsf{PBP}
efficiently incorporates prediction into stochastic system control and avoids
the great complication due to the exponential state space growth in the
prediction window size. We show that \textsf{PBP} can achieve a utility
performance that is within $O(\epsilon)$ of the optimal, for any $\epsilon>0$,
while guaranteeing that the system delay distribution is a
\emph{shifted-to-the-left} version of that under the original Backpressure
algorithm. Hence, the average packet delay under \textsf{PBP} is strictly
better than that under Backpressure, and vanishes with increasing prediction
window size. This implies that the resulting utility-delay tradeoff with
predictive scheduling beats the known optimal $[O(\epsilon),
O(\log(1/\epsilon))]$ tradeoff for systems without prediction.


title:
The Quantum State of Classical Matter II: Thermodynamic Equilibrium and
  Hydrodynamics

abstract:
  In the previous companion paper, we proposed a subclass of wavefunctions to
describe macroscopic solids that resolved and extended the theory quantum
measurement and gave a more specific treatment of quasiparticles. Here we
extend these notions to thermalization of solids and gases and to gas state
hydrodynamics. This gives a modification of the thermodynamic limit to justify
the canonical averages for "typical wavefunctions" without the use of
ensembles. The energetic cost of vorticity is contrasted in the classical and
ultracold gas limits. From this perspective, we then examine the applicability
of thermo and hydro to ultracold gases and compare with the implications of
pure state evolution. We illustrate how the proposed quantum limits on
viscosity could be reinterpreted in terms of Schr\"{o}dinger induced evolution
of the one-body density function but some history dependent measurable
properties should still persist.


title: Quantitative limiting absorption principle in the semiclassical limit

abstract:
  We give an elementary proof of Burq's resolvent bounds for long range
semiclassical Schroedinger operators. Globally, the resolvent norm grows
exponentially in the inverse semiclassical parameter, and near infinity it
grows linearly. We also weaken the regularity assumptions on the potential.


title: Low temperature magnetic transitions of single crystal HoBi

abstract:
  We present resistivity, specific heat and magnetization measurements in high
quality single crystals of HoBi, with a residual resistivity ratio of 126. We
find, from the temperature and field dependence of the magnetization, an
antiferromagnetic transition at 5.7 K, which evolves, under magnetic fields,
into a series of up to five metamagnetic phases.


title: GPU Accelerated Particle Visualization with Splotch

abstract:
  Splotch is a rendering algorithm for exploration and visual discovery in
particle-based datasets coming from astronomical observations or numerical
simulations. The strengths of the approach are production of high quality
imagery and support for very large-scale datasets through an effective mix of
the OpenMP and MPI parallel programming paradigms. This article reports our
experiences in re-designing Splotch for exploiting emerging HPC architectures
nowadays increasingly populated with GPUs. A performance model is introduced
for data transfers, computations and memory access, to guide our re-factoring
of Splotch. A number of parallelization issues are discussed, in particular
relating to race conditions and workload balancing, towards achieving optimal
performances. Our implementation was accomplished by using the CUDA programming
paradigm. Our strategy is founded on novel schemes achieving optimized data
organisation and classification of particles. We deploy a reference simulation
to present performance results on acceleration gains and scalability. We
finally outline our vision for future work developments including possibilities
for further optimisations and exploitation of emerging technologies.


title: Groupoid Crossed Products of Continuous-Trace C*-Algebras

abstract:
  We show that if $(A,G,\alpha)$ is a groupoid dynamical system with $A$
continuous trace, then the crossed product $A\rtimes_{\alpha}G$ is Morita
equivalent to the C*-algebra $C*(\underline G,\underline E)$ of a twist
$\underline E$ over a groupoid $\underline G$ equivalent to $G$. This is a
groupoid analogue of the well known result for the crossed product of a group
acting on an elementary C*-algebra.


title:
Suppression of amplitude-to-phase noise conversion in balanced
  optical-microwave phase detectors

abstract:
  We demonstrate an amplitude-to-phase (AM-PM) conversion coefficient for a
balanced optical-microwave phase detector (BOM-PD) of 0.001 rad, corresponding
to AM-PM induced phase noise 60 dB below the single-sideband relative intensity
noise of the laser. This enables us to generate 8 GHz microwave signals from a
commercial Er-fibre comb with a single-sideband residual phase noise of -131
dBc/Hz at 1 Hz offset frequency and -148 dBc/Hz at 1 kHz offset frequency.


title:
Measurement of the production cross section for Z gamma to nu nu gamma
  in pp collisions at sqrt(s) = 7 TeV and limits on Z Z gamma and Z gamma gamma
  triple gauge boson couplings

abstract:
  A measurement of the Z gamma to nu nu-bar gamma cross section in pp
collisions at sqrt(s) = 7 TeV is presented, using data corresponding to an
integrated luminosity of 5.0 inverse femtobarns collected with the CMS
detector. This measurement is based on the observation of events with an
imbalance of transverse energy in excess of 130 GeV and a single photon in the
absolute pseudorapidity range abs(eta) < 1.4 with transverse energy above 145
GeV. The Z gamma to nu nu-bar gamma production cross section is measured to be
21.1 +/- 4.2 (stat.) +/- 4.3 (syst.) +/- 0.5 (lum.) fb, which agrees with the
standard model prediction of 21.9 +/- 1.1 fb. The results are combined with the
CMS measurement of Z gamma production in the l+ l- gamma final state (where l
is an electron or a muon) to yield the most stringent limits to date on triple
gauge boson couplings: abs(h[3,Z]) < 2.7E-3, abs(h[4,Z]) < 1.3E-5 for Z Z gamma
and abs(h[3,gamma]) < 2.9E-3, abs(h[4,gamma]) < 1.5E-5 for Z gamma gamma
couplings.


title: Anisotropic Percolation on Slabs

abstract:
  We consider anisotropic independent bond percolation models on the slab
$\Z^2\times\{0,\dots,k\}$, where we suppose that the axial (vertical) bonds are
open with probability $p$, while the radial (horizontal) bonds are open with
probability $q$. We study the critical curves for these models and establish
their continuity and strict monotonicity.


title: A first look at Weyl anomalies in shape dynamics

abstract:
  One of the more popular objections towards shape dynamics is the suspicion
that anomalies in the spatial Weyl symmetry will arise upon quantization. The
purpose of this short paper is to establish the tools required for an
investigation of the sort of anomalies that can possibly arise. The first step
is to adapt to our setting Barnich and Henneaux's formulation of gauge
cohomology in the Hamiltonian setting, which serve to decompose the anomaly
into a spatial component and time component. The spatial part of the anomaly,
i.e. the anomaly in the symmetry algebra itself ($[\Omega, \Omega]\propto
\hbar$ instead of vanishing) is given by a projection of the second ghost
cohomology of the Hamiltonian BRST differential associated to $\Omega$, modulo
spatial derivatives. The temporal part, $[\Omega, H]\propto\hbar$ is given by a
different projection of the first ghost cohomology and an extra piece arising
from a solution to a functional differential equation. Assuming locality of the
gauge cohomology groups involved, this part is always local. Assuming locality
for the gauge cohomology groups, using Barnich and Henneaux's results, the
classification of Weyl cohomology for higher ghost numbers performed by
Boulanger, and following the descent equations, we find a complete
characterizations of anomalies in 3+1 dimensions. The spatial part of the
anomaly and the first component of the temporal anomaly are always local given
these assumptions even in shape dynamics. The part emerging from the solution
of the functional differential equations explicitly involves the shape dynamics
Hamiltonian, and thus might be non-local. If one restricts this extra piece of
the temporal anomaly to be also local, then overall no \emph{local} Weyl
anomalies, either temporal or spatial, emerge in the 3+1 case.


title:
Truncated Connectivities in a highly supercritical anisotropic
  percolation model

abstract:
  We consider an anisotropic bond percolation model on $\mathbb{Z}^2$, with
$\textbf{p}=(p_h,p_v)\in [0,1]^2$, $p_v>p_h$, and declare each horizontal
(respectively vertical) edge of $\mathbb{Z}^2$ to be open with probability
$p_h$(respectively $p_v$), and otherwise closed, independently of all other
edges. Let $x=(x_1,x_2) \in \mathbb{Z}^2$ with $0<x_1<x_2$, and
$x'=(x_2,x_1)\in \mathbb{Z}^2$. It is natural to ask how the two point
connectivity function $\prob(\{0\leftrightarrow x\})$ behaves, and whether
anisotropy in percolation probabilities implies the strict inequality
$\prob(\{0\leftrightarrow x\})>\prob(\{0\leftrightarrow x'\})$. In this note we
give an affirmative answer in the highly supercritical regime.


title: Localization of Negative Energy and the Bekenstein Bound

abstract:
  A simple argument shows that negative energy cannot be isolated far away from
positive energy in a conformal field theory and strongly constrains its
possible dispersal. This is also required by consistency with the Bekenstein
bound written in terms of the positivity of relative entropy. We prove a new
form of the Bekenstein bound based on the monotonicity of the relative entropy,
involving a "free" entropy enclosed in a region which is highly insensitive to
space-time entanglement, and show that it further improves the negative energy
localization bound.


title: Hemispherical Power Asymmetry from Scale-Dependent Modulated Reheating

abstract:
  We propose a new model for the hemispherical power asymmetry of the CMB based
on modulated reheating. Non-Gaussianity from modulated reheating can be small
enough to satisfy the bound from Planck if the dominant modulation of the
inflaton decay rate is linear in the modulating field $\sigma$. $\sigma$ must
then acquire a spatially-modulated power spectrum with a red scale-dependence.
This can be achieved if the primordial perturbation of $\sigma$ is generated
via tachyonic growth of a complex scalar field. Modulated reheating due to
$\sigma$ then produces a spatially modulated and scale-dependent sub-dominant
contribution to the adiabatic density perturbation. We show that it is possible
to account for the observed asymmetry while remaining consistent with bounds
from quasar number counts, non-Gaussianity and the CMB temperature quadupole.
The model predicts that the adiabatic perturbation spectral index and its
running will be modified by the modulated reheating component.


title:
Extension of coupled-cluster theory with a non-iterative treatment of
  connected triply excited clusters to three-body Hamiltonians

abstract:
  We generalize the coupled-cluster (CC) approach with singles, doubles, and
the non-iterative treatment of triples termed $\Lambda$CCSD(T) to Hamiltonians
containing three-body interactions. The resulting method and the underlying CC
approach with singles and doubles only (CCSD) are applied to the medium-mass
closed-shell nuclei O16, O24, and Ca40. By comparing the results of CCSD and
$\Lambda$CCSD(T) calculations with explicit treatment of three-nucleon
interactions to those obtained using an approximate treatment in which they are
included effectively via the zero-, one-, and two-body components of the
Hamiltonian in normal-ordered form, we quantify the contributions of the
residual three-body interactions neglected in the approximate treatment. We
find these residual normal-ordered three-body contributions negligible for the
$\Lambda$CCSD(T) method, although they can become significant in the
lower-level CCSD approach, particularly when the nucleon-nucleon interactions
are soft.


title: Kloosterman sums in residue rings

abstract:
  In the present paper, we generalize some of the results on Kloosterman sums
proven in \cite{BG} for prime moduli to general moduli. This requires to
establish the corresponding additive properties of the reciprocal set $$
I^{-1}=\{x^{-1}:\quad x\in I\}, $$ where $I$ is an interval in the ring of
residue classes modulo a large positive integer. We apply our bounds on
multilinear exponential sums to the Brun-Titchmarsh theorem and the estimate of
very short Kloosterman sums, hence generalizing our earlier work to the setting
of general modulus.


title: Learning to answer questions

abstract:
  We present an open-domain Question-Answering system that learns to answer
questions based on successful past interactions. We follow a pattern-based
approach to Answer-Extraction, where (lexico-syntactic) patterns that relate a
question to its answer are automatically learned and used to answer future
questions. Results show that our approach contributes to the system's best
performance when it is conjugated with typical Answer-Extraction strategies.
Moreover, it allows the system to learn with the answered questions and to
rectify wrong or unsolved past questions.


title:
Simultaneous X-ray and Radio Observations of Rotating Radio Transient
  J1819-1458

abstract:
  We present the results of simultaneous radio and X-ray observations of PSR
J1819-1458. Our 94-ks XMM-Newton observation of the high magnetic field 5*10^13
G pulsar reveals a blackbody spectrum (kT~130 eV) with a broad absorption
feature, possibly composed of two lines at ~1.0 and ~1.3 keV. We performed a
correlation analysis of the X-ray photons with radio pulses detected in 16.2
hours of simultaneous observations at 1-2 GHz with the Green Bank, Effelsberg,
and Parkes telescopes, respectively. Both the detected X-ray photons and radio
pulses appear to be randomly distributed in time. We find tentative evidence
for a correlation between the detected radio pulses and X-ray photons on
timescales of less than 10 pulsar spin periods, with the probability of this
occurring by chance being 0.46%. This suggests that the physical process
producing the radio pulses may also heat the polar-cap.


title: Reduced purities as measures of decoherence in many-electron systems

abstract:
  A hierarchy of measures of decoherence for many-electron systems that is
based on the purity and the hierarchy of reduced electronic density matrices is
presented. These reduced purities can be used to characterize electronic
decoherence in the common case when the many-body electronic density matrix is
not known and only reduced information about the electronic subsystem is
available. Being defined from reduced electronic quantities, the interpretation
of the reduced purities is more intricate than the usual (many-body) purity.
This is because the nonidempotency of the $r$-body reduced electronic density
matrix that is the basis of the reduced purity measures can arise due to
decoherence or due to electronic correlations. To guide the interpretation,
explicit expressions are provided for the one-body and two-body reduced
purities for a general electronic state. Using them, the information content
and structure of the one-body and two-body reduced purities is established, and
limits on the changes that decoherence can induce are elucidated. The practical
use of the reduced purities to understand decoherence dynamics in many-electron
systems is exemplified through an analysis of the electronic decoherence
dynamics in a model molecular system.

categories: quant-ph cond-mat.mtrl-sci physics.chem-ph physics.optics