title:
P-adic integration on ray class groups and non-ordinary p-adic
  L-functions

abstract:
  We study the theory of finite-order p-adic functions and distributions on ray
class groups of number fields, and apply this to the construction of (possibly
unbounded) p-adic L-functions for automorphic forms on GL(2) which may be
non-ordinary at the primes above p. As a consequence, we obtain a "plus-minus"
decomposition of the p-adic L-functions of automorphic forms for GL(2) over an
imaginary quadratic field with p split and Hecke eigenvalues 0 at the primes
above p, confirming a conjecture of B.D. Kim.


title:
Low paleopressure of the Martian atmosphere estimated from the size
  distribution of ancient craters

abstract:
  The decay of the martian atmosphere - which is dominated by carbon dioxide -
is a component of the long-term environmental change on Mars from a climate
that once allowed rivers to flow to the cold and dry conditions of today. The
minimum size of craters serves as a proxy for palaeopressure of planetary
atmospheres, because thinner atmospheres permit smaller objects to reach the
surface at high velocities and form craters. The Aeolis Dorsa region near Gale
crater on Mars contains a high density of preserved ancient craters interbedded
with river deposits and thus can provide constraints on atmospheric density
around the time of fluvial activity. Here we use high-resolution orthophotos
and digital terrain models from the Mars Reconnaissance Orbiter to identify
ancient craters in Aeolis Dorsa that date to about 3.6 Gyr ago and compare
their size distribution with models of atmospheric filtering of impactors. We
obtain an upper limit of 0.9$\pm$0.1 bar, rising to 1.9$\pm$0.2 bar if rimmed
circular mesas - interpreted to be erosionally-resistant fills of floors of
impact craters - are excluded. We assume target properties appropriate for
desert alluvium: if sediment had rock-like rock-mass strength similar to
bedrock at the time of impact, the upper limit increases by a factor of up to
two. If Mars did not have a stable multibar atmosphere at the time that the
rivers were flowing - as suggested by our results - then the warm and wet
CO2/H2O greenhouse is ruled out, and long-term average temperatures were most
likely below freezing.


title: Evolution of primordial magnetic fields in mean-field approximation

abstract:
  We study the evolution of phase-transition-generated cosmic magnetic fields
coupled to the primeval cosmic plasma in turbulent and viscous free-streaming
regimes. The evolution laws for the magnetic energy density and correlation
length, both in helical and non-helical cases, are found by solving the
autoinduction and Navier-Stokes equations in mean-field approximation.
Analytical results are derived in Minkowski spacetime and then extended to the
case of a Friedmann universe with zero spatial curvature, both in radiation and
matter dominated eras. The three possible viscous free-streaming phases are
characterized by a drag term in the Navier-Stokes equation which depends on the
free-streaming properties of neutrinos, photons, or hydrogen atoms,
respectively. In the case of non-helical magnetic fields, the magnetic
intensity $B$ and the magnetic correlation length $\xi_B$ evolve asymptotically
with the temperature $T$ as $B(T) \simeq \kappa_B (N_i v_i)^{\varrho_1}
(T/T_i)^{\varrho_2}$ and $\xi_B(T) \simeq \kappa_\xi (N_i v_i)^{\varrho_3}
(T/T_i)^{\varrho_4}$. Here, $T_i$, $N_i$, and $v_i$ are, respectively, the
temperature, the number of magnetic domains per horizon length, and the bulk
velocity at the onset of the particular regime. The coefficients $\kappa_B$,
$\kappa_\xi$, $\varrho_1$, $\varrho_2$, $\varrho_3$, and $\varrho_4$, depend on
the index of the assumed initial power-law magnetic spectrum, $p$, and on the
particular regime, with the order-one constants $\kappa_B$ and $\kappa_\xi$
depending also on the cut-off adopted for the initial magnetic spectrum. In the
helical case, the quasi-conservation of the magnetic helicity implies, apart
from logarithmic corrections and a factor proportional to the initial
fractional helicity, power-like evolution laws equal to those in the
non-helical case, but with $p$ equal to zero.


title:
A Model for an Intelligent and Adaptive Tutor based on Web by Jackson's
  Learning Styles Profiler and Expert Systems

abstract:
  Todays, Intelligent and web-based E-Learning is one of the important area in
E-Learning. This paper integrates an intelligent and web-based E-Learning with
expert system technology to be able to model the learning styles of the
learners using Jackson's model. It is intelligent because it can interact with
the learners and offer them some subjects in Pedagogy view. Learning process of
this system is in the following. First it determines learner's individual
characteristics and learning styles based on a questionnaire in Jackson's
learning styles profiler. Learning styles profiler is a modern measure of
individual differences in learning style. Then learner's model is obtained and
an Expert system simulator plans a "pre-test" and rates him. The concept would
be presented if the learner scores enough. Subsequently, the system evaluates
him by a "post-test". Finally the learner's model would be updated by the
modeler based on try-and-error. The proposed system can be available Every Time
and Every Where (ETEW) through the web. It improves the learning performance
and has some important advantages such as high speed, simplicity of learning,
low cost and be available ETEW.


title: Phase-sticking in one-dimensional Josephson Junction Chains

abstract:
  We studied current-voltage characteristics of long one dimensional Josephson
junction chains with Josephson energy much larger than charging energy, $E_J
\gg E_C$. In this regime, typical IV curves of the samples consist of a
supercurrent branch at low bias voltages followed by a voltage-independent
chain current branch, $I_{Chain}$ at high bias. Our experiments showed that
$I_{Chain}$ is not only voltage-independent but it is also practically
temperature-independent up to $T_C$. We have successfully model the transport
properties in these chains using a capacitively shunted junction model with
nonlinear damping.


title:
A Paradigm for the Application of Cloud Computing in Mobile Intelligent
  Tutoring Systems

abstract:
  Nowadays, with the rapid growth of cloud computing, many industries are going
to move their computing activities to clouds. Researchers of virtual learning
are also looking for the ways to use clouds through mobile platforms. This
paper offers a model to accompany the benefits of "Mobile Intelligent Learning"
technology and "Cloud Computing". The architecture of purposed system is based
on multi-layer architecture of Mobile Cloud Computing. Despite the existing
challenges, the system has increased the life of mobile device battery. It will
raise working memory capacity and processing capacity of the educational system
in addition to the greater advantage of the educational system. The proposed
system allows the users to enjoy an intelligent learning every-time and
every-where, reduces training costs and hardware dependency, and increases
consistency, efficiency, and data reliability.


title:
Secure Optical Networks Based on Quantum Key Distribution and Weakly
  Trusted Repeaters

abstract:
  In this paper we explore how recent technologies can improve the security of
optical networks. In particular, we study how to use quantum key distribution
(QKD) in common optical network infrastructures and propose a method to
overcome its distance limitations. QKD is the first technology offering
information theoretic secret-key distribution that relies only on the
fundamental principles of quantum physics. Point-to-point QKD devices have
reached a mature industrial state; however, these devices are severely limited
in distance, since signals at the quantum level (e.g. single photons) are
highly affected by the losses in the communication channel and intermediate
devices. To overcome this limitation, intermediate nodes (i.e. repeaters) are
used. Both, quantum-regime and trusted, classical, repeaters have been proposed
in the QKD literature, but only the latter can be implemented in practice. As a
novelty, we propose here a new QKD network model based on the use of not fully
trusted intermediate nodes, referred as weakly trusted repeaters. This approach
forces the attacker to simultaneously break several paths to get access to the
exchanged key, thus improving significantly the security of the network. We
formalize the model using network codes and provide real scenarios that allow
users to exchange secure keys over metropolitan optical networks using only
passive components. Moreover, the theoretical framework allows to extend these
scenarios not only to accommodate more complex trust constraints, but also to
consider robustness and resiliency constraints on the network.


title:
The $\beta$ Cep/SPB star 12 Lacertae: extended mode identification and
  complex seismic modelling

abstract:
  Results of mode identification and seismic modelling of the $\beta$ Cep/SBP
star 12 Lacertae are presented. Using data on the multi-colour photometry and
radial velocity variations, we determine or constrain the mode degree, $\ell$,
for all pulsational frequencies. Including the effects of rotation, we show
that the dominant frequency, $\nu_1$, is most likely a pure $\ell=1$ mode and
the low frequency, $\nu_A$, is a dipole retrograde mode. We construct a set of
seismic models which fit two pulsational frequencies corresponding to the modes
$\ell= 0,$ p$_1$ and $\ell= 1,$ g$_1$ and reproduce also the complex amplitude
of the bolometric flux variations, $f$, for both frequencies simultaneously.
Some of these seismic models reproduce also the frequency $\nu_A$, as a mode
$\ell= 1,$ g$_{13}$ or g$_{14}$, and its empirical values of $f$. Moreover, it
was possible to find a model fitting the six 12 Lac frequencies (the first five
and $\nu_A$), only if the rotational splitting was calculated for a velocity of
$V_{\rm rot}\approx 75$ km/s. In the next step, we check the effects of model
atmospheres, opacity data, chemical mixture and opacity enhancement. Our
results show that the OP tables are preferred and an increase of opacities in
the $Z-$bump spoils the concordance of the empirical and theoretical values of
$f$.


title:
Grain growth beyond the Mullins model, capturing the complex physics
  behind universal grain size distributions

abstract:
  Grain growth experiments on thin metallic films have shown the geometric and
topological characteristics of the grain structure to be universal and
independent of many experimental conditions. The universal size distribution,
however, is found to differ both qualitatively and quantitatively from the
standard Mullins curvature driven model of grain growth; with the experiments
exhibiting an excess of small grains (termed an "ear") and an excess of very
large grains (termed a "tail") compared with the model. While a plethora of
extensions of the Mullins model have been proposed to explain these
characteristics, none have been successful. In this work, large scale
simulations of a model that resolves the atomic scale on diffusive time scales,
the phase field crystal model, is used to examine the complex phenomena of
grain growth. The results are in remarkable agreement with the experimental
results, recovering the characteristic "ear" and "tail" features of the
experimental grain size distribution. The simulations also indicate that while
the geometric and topological characteristics are universal, the dynamic growth
exponent is not.


title: Coordinating metaheuristic agents with swarm intelligence

abstract:
  Coordination of multi agent systems remains as a problem since there is no
prominent method to completely solve this problem. Metaheuristic agents are
specific implementations of multi-agent systems, which imposes working together
to solve optimisation problems with metaheuristic algorithms. The idea borrowed
from swarm intelligence seems working much better than those implementations
suggested before. This paper reports the performance of swarms of simulated
annealing agents collaborating with particle swarm optimization algorithm. The
proposed approach is implemented for multidimensional knapsack problem and has
resulted much better than some other works published before.


title:
Properties of the three-dimensional structure in the central region of
  the supernova remnant SNR 0540-69.3

abstract:
  We present and discuss new visual wavelength-range observations of the inner
regions of the supernova remnant SNR 0540-69.3 that is located in the Large
Magellanic Cloud (LMC). These observations provide us with more spatial and
spectral information than were previously available for this object. We use
these data to create a detailed three-dimensional model of the remnant,
assuming linear expansion of the ejecta. With the observations and the model we
study the general three-dimensional structure of the remnant, and the influence
of an active region in the remnant - a "blob" - that we address in previous
papers. We used the fibre-fed integral-field spectrograph VIMOS at the Very
Large Telescope of the European Southern Observatory. The observations provide
us with three-dimensional data in [OIII]5007 and [SII]6717,6731 at an 0.33x0.33
spatial sampling and a velocity resolution of about 35 km/s. We decomposed the
two, partially overlapping, sulphur lines and used them to calculate electron
densities across the remnant at high signal-to-noise ratio. Our analysis
reveals a structure that stretches from the position of the "blob", and into
the plane of the sky at a position angle of about 60 degrees. We speculate that
the pulsar is positioned along this activity axis, where it has a velocity
along the line of sight of a few hundred km/s. The "blob" is most likely a
region of shock activity, as it is mainly bright in [SII]; future observations
of [OII]3729 would be useful to test whether the S/O abundance ratio is higher
than average for that location in the remnant. The striking resemblance in
X-rays between the pulsar wind nebula (PWN) of SNR 0540-69.3 and the Crab, in
combination with our findings in this paper, suggests that the symmetry axis is
part of a torus in the PWN. (abridged)


title: Self-averaging stochastic Kohn-Sham density functional theory

abstract:
  We formulate the Kohn-Sham density functional theory (KS-DFT) as a
statistical theory in which the electron density is deter-mined from an average
of correlated stochastic densities in a trace formula. The key idea is that it
is sufficient to converge the total energy per electron to within a predefined
statistical error in order to obtain reliable estimates of the electronic band
structure, the forces on nuclei, the density and its moments, etc. The
fluctuations in the total energy per electron are guaranteed to decay to zero
as the system size increases. This facilitates "self-averaging" which leads to
the first ever report of sublinear scaling KS-DFT electronic structure. The
approach sidesteps calculation of the density matrix and thus is insensitive to
its evasive sparseness, as demonstrated here for silicon nanocrystals. The
formalism is not only appealing in terms of its promise to far push the limits
of application of KS-DFT, but also represents a cognitive change in the way we
think of electronic structure calculations as this stochastic theory seamlessly
converges to the thermodynamic limit.


title:
Model evidence of a superconducting state with a full energy gap in
  small cuprate islands

abstract:
  We investigate subdominant order parameters stabilizing at low temperatures
in nano-scale high-T$_c$ cuprate islands, motivated by the recent observation
of a fully gapped state in nanosized YBa$_2$Cu$_3$O$_{7-\delta}$ [D. Gustafsson
{\it et al}, Nature Nanotech. {\bf 8}, 25 (2013)]. Using complementary
quasi-classical and tight-binding Bogoliubov-de Gennes methods, we show on
distinctly different properties dependent on the symmetry being $d_{x^2-y^2}+i
s$ or $d_{x^2-y^2}+i d_{xy}$. We find that a surface-induced $d_{x^2-y^2}+i s$
phase creates a global spectroscopic gap which increases with applied magnetic
field, consistent with experimental observation.


title: Multiobjective optimization in Gene Expression Programming for Dew Point

abstract:
  The processes occurring in climatic change evolution and their variations
play a major role in environmental engineering. Different techniques are used
to model the relationship between temperatures, dew point and relative
humidity. Gene expression programming is capable of modelling complex realities
with great accuracy, allowing, at the same time, the extraction of knowledge
from the evolved models compared to other learning algorithms. This research
aims to use Gene Expression Programming for modelling of dew point. Generally,
accuracy of the model is the only objective used by selection mechanism of GEP.
This will evolve large size models with low training error. To avoid this
situation, use of multiple objectives, like accuracy and size of the model are
preferred by Genetic Programming practitioners. Multi-objective problem finds a
set of solutions satisfying the objectives given by decision maker.
Multiobjective based GEP will be used to evolve simple models. Various
algorithms widely used for multi objective optimization like NSGA II and SPEA 2
are tested for different test cases. The results obtained thereafter gives idea
that SPEA 2 is better algorithm compared to NSGA II based on the features like
execution time, number of solutions obtained and convergence rate. Thus
compared to models obtained by GEP, multi-objective algorithms fetch better
solutions considering the dual objectives of fitness and size of the equation.
These simple models can be used to predict dew point.


title:
Variable selection for general index models via sliced inverse
  regression

abstract:
  Variable selection, also known as feature selection in machine learning,
plays an important role in modeling high dimensional data and is key to
data-driven scientific discoveries. We consider here the problem of detecting
influential variables under the general index model, in which the response is
dependent of predictors through an unknown function of one or more linear
combinations of them. Instead of building a predictive model of the response
given combinations of predictors, we model the conditional distribution of
predictors given the response. This inverse modeling perspective motivates us
to propose a stepwise procedure based on likelihood-ratio tests, which is
effective and computationally efficient in identifying important variables
without specifying a parametric relationship between predictors and the
response. For example, the proposed procedure is able to detect variables with
pairwise, three-way or even higher-order interactions among $p$ predictors with
a computational time of $O(p)$ instead of $O(p^k)$ (with $k$ being the highest
order of interactions). Its excellent empirical performance in comparison with
existing methods is demonstrated through simulation studies as well as real
data examples. Consistency of the variable selection procedure when both the
number of predictors and the sample size go to infinity is established.


title:
The influence of magnetic fields, turbulence, and UV radiation on the
  formation of supermassive black holes

abstract:
  Context. The seeds of the supermassive black holes (SMBHs) with masses of
~10^9 M_Sun observed already at z ~ 6 may have formed through the direct
collapse of primordial gas in T_vir >~ 10^4 K halos, whereby the gas must stay
hot (~10^4 K) in order to avoid fragmentation.
  Aims. The interplay between magnetic fields, turbulence, and a UV radiation
background during the gravitational collapse of primordial gas in a halo is
explored; in particular, the possibilities for avoiding fragmentation are
examined.
  Methods. Using an analytical one-zone model, the evolution of a cloud of
primordial gas is followed from its initial cosmic expansion through
turnaround, virialization, and collapse up to a density of 10^7 cm-3.
  Results. It was found that in halos with no significant turbulence, the
critical UV background intensity (J_21^crit) for keeping the gas hot is lower
by a factor ~10 for an initial comoving magnetic field B_0 ~ 2 nG than for the
zero-field case, and even lower for stronger fields. In turbulent halos,
J_21^crit is found to be a factor ~10 lower than for the
zero-field-zero-turbulence case, and the stronger the turbulence (more massive
halo and/or stronger turbulent heating) the lower J_21^crit.
  Conclusions. The reduction in J_21^crit is particularly important, since it
exponentially increases the number of halos exposed to a supercritical
radiation background.


title: Link Prediction with Social Vector Clocks

abstract:
  State-of-the-art link prediction utilizes combinations of complex features
derived from network panel data. We here show that computationally less
expensive features can achieve the same performance in the common scenario in
which the data is available as a sequence of interactions. Our features are
based on social vector clocks, an adaptation of the vector-clock concept
introduced in distributed computing to social interaction networks. In fact,
our experiments suggest that by taking into account the order and spacing of
interactions, social vector clocks exploit different aspects of link formation
so that their combination with previous approaches yields the most accurate
predictor to date.


title: Two-mode back-action-evading measurements in cavity optomechanics

abstract:
  We study theoretically a three-mode optomechanical system where two
mechanical oscillators are coupled to a single cavity mode. By using two-tone
(i.e. amplitude-modulated) driving of the cavity, it is possible to couple the
cavity to a single collective quadrature of the mechanical oscillators. In such
a way, a back-action-evading measurement of the collective mechanical
quadrature is possible. We discuss how this can allow one to measure both
quadratures of a mechanical force beyond the full quantum limit, paying close
attention to the role of dissipation and experimental imperfections. We also
describe how this scheme allows one to generate steady-state mechanical
entanglement; namely, one can conditionally prepare an entangled, two-mode
squeezed mechanical state. This entanglement can be verified directly from the
measurement record by applying a generalized version of Duan's inequality; we
also discuss how feedback can be used to produce unconditional entanglement.


title: Phyllotaxis on surfaces of constant Gaussian curvature

abstract:
  A close packed organization with circular symmetry of a large number of small
discs on a plane is obtained when the centres of the discs are distributed
according to the algorithm of phyllotaxis. We study here the distributions
obtained on surfaces of constant Gaussian curvatures, positive for the sphere
or negative for the hyperbolic plane. We examine how the properties of
homogeneity, isotropy and self-similarity typical of the distribution on the
plane, and resulting from the presence of circular grain boundaries with
quasicrystalline sequences, are affected by the curvature of the bearing
surface. The quasicrystalline sequences of the grain boundaries appear indeed
to be structural invariants, but the widths of the grains they separate vary
differently with the curvature of the surface. The self similarity of the whole
organization observed on the plane is therefore lost on the hyperbolic plane
and the sphere. The evolutions of the local order within the grains show no
differences except on the equatorial belt of the sphere where the isotropy is
decreased owing to the symmetry of this finite surface around its equator.


title: Gauged Linear Sigma Model for Exotic Five-brane

abstract:
  We study an N=(4,4) supersymmetric gauged linear sigma model which gives rise
to the nonlinear sigma model for multi-centered KK-monopoles. We find a new
T-duality transformation of the model even in the presence of F-terms.
Performing T-duality, we find the gauged linear sigma model whose IR limit
describes the exotic 522-brane with B-field.


title: Superconformal nets and noncommutative geometry

abstract:
  This paper provides a further step in our program of studying superconformal
nets over S^1 from the point of view of noncommutative geometry. For any such
net A and any family Delta of localized endomorphisms of the even part A^gamma
of A, we define the locally convex differentiable algebra A_Delta with respect
to a natural Dirac operator coming from supersymmetry. Having determined its
structure and properties, we study the family of spectral triples and JLO
entire cyclic cocycles associated to elements in Delta and show that they are
nontrivial and that the cohomology classes of the cocycles corresponding to
inequivalent endomorphisms can be separated through their even or odd index
pairing with K-theory in various cases. We illustrate some of those cases in
detail with superconformal nets associated to well-known CFT models, namely
super-current algebra nets and super-Virasoro nets. All in all, the result
allows us to encode parts of the representation theory of the net in terms of
noncommutative geometry.


title: Decoherence free Bd and Bs meson systems

abstract:
  We study the impact of decoherence on B meson systems with specific emphasis
on Bs. For consistency we also study the Bd mesons based on the most recent
data. We find that the Bd mesons are 34 sigma away from total decoherence,
while the Bs mesons are seen to be upto 31sigma away from total decoherence.
Thus, our results prove, with experimental verity, that neutral meson systems
are free from decoherence effects. Therefore, this provides a very useful
laboratory for testing the foundations of quantum mechanics.


title:
H to Zn Ionization Equilibrium for the Non-Maxwellian Electron
  kappa-distributions: Updated Calculations

abstract:
  New data for calculation of the ionization and recombination rates have have
been published in the past few years. Most of these are included in CHIANTI
database. We used these data to calculate collisional ionization and
recombination rates for the non-Maxwellian kappa-distributions with an enhanced
number of particles in the high-energy tail, which have been detected in the
solar transition region and the solar wind. Ionization equilibria for elements
H to Zn are derived. The kappa-distributions significantly influence both the
ionization and recombination rates and widen the ion abundance peaks. In
comparison with Maxwellian distribution, the ion abundance peaks can also be
shifted to lower or higher temperatures. The updated ionization equilibrium
calculations result in large changes for several ions, notably Fe VIII--XIV.
The results are supplied in electronic form compatible with the CHIANTI
database.


title:
Deterministic Many-Resonator W Entanglement of Nearly Arbitrary
  Microwave States via Attractive Bose-Hubbard Simulation

abstract:
  Multipartite entanglement of large numbers of physically distinct linear
resonators is of both fundamental and applied interest, but there have been no
feasible proposals to date for achieving it. At the same time, the Bose-Hubbard
model with attractive interactions (ABH) is theoretically known to have a phase
transition from the superfluid phase to a highly entangled nonlocal
superposition, but observation of this phase transition has remained out of
experimental reach. In this theoretical work, we jointly address these two
problems by (1) proposing an experimentally accessible quantum simulation of
the ABH phase transition in an array of tunably coupled superconducting circuit
microwave resonators and (2) incorporating the simulation into a highly
scalable protocol that takes as input any microwave resonator state with
negligible occupation of number states |0> and |1> and nonlocally superposes it
across the whole array of resonators. The large-scale multipartite entanglement
produced by the protocol is of the W-type, which is well-known for its
robustness. The protocol utilizes the ABH phase transition to generate the
multipartite entanglement of all of the resonators in parallel, and is
therefore deterministic and permits an increase in resonator number without
increase in protocol complexity; the number of resonators is limited instead by
system characteristics such as resonator frequency disorder and inter-resonator
coupling strength. Only one local and two global controls are required for the
protocol. We numerically demonstrate the protocol with realistic system
parameters, and estimate that current experimental capabilities can realize the
protocol with high fidelity for greater than 40 resonators.


title:
Stronger instruments via integer programming in an observational study
  of late preterm birth outcomes

abstract:
  In an optimal nonbipartite match, a single population is divided into matched
pairs to minimize a total distance within matched pairs. Nonbipartite matching
has been used to strengthen instrumental variables in observational studies of
treatment effects, essentially by forming pairs that are similar in terms of
covariates but very different in the strength of encouragement to accept the
treatment. Optimal nonbipartite matching is typically done using network
optimization techniques that can be quick, running in polynomial time, but
these techniques limit the tools available for matching. Instead, we use
integer programming techniques, thereby obtaining a wealth of new tools not
previously available for nonbipartite matching, including fine and near-fine
balance for several nominal variables, forced near balance on means and optimal
subsetting. We illustrate the methods in our on-going study of outcomes of
late-preterm births in California, that is, births of 34 to 36 weeks of
gestation. Would lengthening the time in the hospital for such births reduce
the frequency of rapid readmissions? A straightforward comparison of babies who
stay for a shorter or longer time would be severely biased, because the
principal reason for a long stay is some serious health problem. We need an
instrument, something inconsequential and haphazard that encourages a shorter
or a longer stay in the hospital. It turns out that babies born at certain
times of day tend to stay overnight once with a shorter length of stay, whereas
babies born at other times of day tend to stay overnight twice with a longer
length of stay, and there is nothing particularly special about a baby who is
born at 11:00 pm.


title: Square roots of Hamiltonian Diffeomorphisms

abstract:
  In this article we prove that on any closed symplectic manifold there exists
an arbitrarily $C^\infty$-small Hamiltonian diffeomorphism not admitting a
square root.


title: Integrability of zero-dimensional replica field theories at beta=1

abstract:
  Building on insights from the theory of integrable lattices, the
integrability is claimed for nonlinear replica sigma models derived in the
context of real symmetric random matrices. Specifically, the fermionic and the
bosonic replica partition functions are proven to form a single
(supersymmetric) Pfaff-KP hierarchy whose replica limit is shown to reproduce
the celebrated nonperturbative formula for the density-density eigenvalue
correlation function in the infinite-dimensional Gaussian Orthogonal Ensemble.
Implications of the formalism outlined are briefly discussed.

categories: math-ph cond-mat.dis-nn hep-th math.MP nlin.SI


title: Integer Arithmetic With Hybrid Quantum-Classical Circuits

abstract:
  Quantum circuits which perform integer arithmetic could potentially
outperform their classical counterparts. In this paper, a quantum circuit is
considered which performs a specific computational pattern on classically
represented integers to accelerate the computation. Such a hybrid circuit could
be embedded in a conventional computer architecture as a quantum device or
accelerator. In particular, a quantum multiply-add circuit (QMAC) using a
Quantum Fourier Transform (QFT) is proposed which can perform the calculation
on conventional integers faster than its conventional counterpart. Whereas
classically applying a multiply-adder (MAC) $n$ times to $k$ bit integers would
require $O(n \log k)$ parallel steps, the hybrid QMAC needs only $O(n + k)$
steps for the exact result and $O(n + \log k)$ steps for an approximate result.


title:
Tunneling Current Spectra of a Metal Core/Semiconductor Shell Quantum
  Dot Molecule

abstract:
  The transport properties of a metal core/semiconductor shell quantum dot
molecule (QDM) embedded in a matrix connected to metallic electrodes are
theoretically studied in the framework of Keldysh Green function technique. The
effects of the electron plasmon interactions (EPIs) on the tunneling current
spectra of QDM are examined. The energy levels of the QDs, intradot and
interdot Coulomb interactions, electron interdot hopping strengths, and
tunneling rates of QDs are renormalized by the EPIs. The differential
conductance spectra show peaks arising from the plasmon assisted tunneling
process, intradot and interdot Coulomb interactions, and coherent tunneling
between the QDs.


title: Near-optimal Binary Compressed Sensing Matrix

abstract:
  Compressed sensing is a promising technique that attempts to faithfully
recover sparse signal with as few linear and nonadaptive measurements as
possible. Its performance is largely determined by the characteristic of
sensing matrix. Recently several zero-one binary sensing matrices have been
deterministically constructed for their relative low complexity and competitive
performance. Considering the complexity of implementation, it is of great
practical interest if one could further improve the sparsity of binary matrix
without performance loss. Based on the study of restricted isometry property
(RIP), this paper proposes the near-optimal binary sensing matrix, which
guarantees nearly the best performance with as sparse distribution as possible.
The proposed near-optimal binary matrix can be deterministically constructed
with progressive edge-growth (PEG) algorithm. Its performance is confirmed with
extensive simulations.


title: The Effective Temperature Scale of M dwarfs

abstract:
  Despite their large number in the Galaxy, M dwarfs remain elusive objects and
the modeling of their photospheres has long remained a challenge (molecular
opacities, dust cloud formation). Our objectives are to validate the BT-Settl
model atmospheres, update the M dwarf T eff -spectral type relation, and find
the atmospheric parameters of the stars in our sample. We compare two samples
of optical spectra covering the whole M dwarf sequence with the most recent
BT-Settl synthetic spectra and use a \c{hi}2 minimization technique to
determine Teff . The first sample consists of 97 low-resolution spectra
obtained with NTT at La Silla Observatory. The second sample contains 55
mid-resolution spectra obtained at the Siding Spring Observatory (SSO). The
spectral typing is realized by comparison with already classified M dwarfs. We
show that the BT-Settl synthetic spectra reproduce the slope of the spectral
energy distribution and most of its features. Only the CaOH band at 5570{\AA}
and AlH and NaH hydrides in the blue part of the spectra are still missing in
the models. The Teff-scale obtained with the higher resolved SSO 2.3 m spectra
is consistent with that obtained with the NTT spectra. We compare our Teff
scale with those of other authors and to published isochrones using the
BT-Settl colors. We also present relations between effective temperature,
spectral type and colors of the M dwarfs.


title: Simultaneous approximation for scheduling problems

abstract:
  Motivated by the problem to approximate all feasible schedules by one
schedule in a given scheduling environment, we introduce in this paper the
concepts of strong simultaneous approximation ratio (SAR) and weak simultaneous
approximation ratio (WAR). Then we study the two parameters under various
scheduling environments, such as, non-preemptive, preemptive or fractional
scheduling on identical, related or unrelated machines.


title:
Limits on the accuracy of isoelectronic gravity measurements at short
  separation due to patch potentials

abstract:
  In force sensing experiments intended to measure non-Newtonian gravitational
signals electrostatic patch potentials can give rise to spurious forces,
torques, and noise. Undesired patch-induced interactions can lead to systematic
effects which limit accuracy, and noise can place lower limits on precision. In
this paper we develop the theory for electrostatic patch effects on
isoelectronic experiments, where their mean effect is nullified by design. We
derive analytical expressions for the patch force and torque power spectrum to
estimate the limitations introduced by patch-induced signals.


title: Bernoulli effect at free revolving flow braking

abstract:
  In this research paper, analytical equations for the calculation of radial
flow due to the braking on the flat surface plane of revolving flow were
obtained. The calculation method is based on the use of pressure force balance
equation, viscid friction and inertia. Three motion equations for
incompressible, polytropic and isothermal flow were obtained, the type of a
cumulative curve for the incompressible flow has been shown. Possibility of the
use of radial flow for the compression of water steam cloud has been shown.
  Keywords: radial flow, revolving flow, cloud compression.


title: The zeta functions of the Fano surfaces of cubic threefolds

abstract:
  We give an algorithm to compute the zeta function of the Fano surface of
lines of a smooth cubic threefold $F$ into $\mathbb{P}^4$ defined over a finite
field. We obtain some examples of Fano surfaces with supersingular reduction.


title:
A new Bayesian ensemble of trees classifier for identifying multi-class
  labels in satellite images

abstract:
  Classification of satellite images is a key component of many remote sensing
applications. One of the most important products of a raw satellite image is
the classified map which labels the image pixels into meaningful classes.
Though several parametric and non-parametric classifiers have been developed
thus far, accurate labeling of the pixels still remains a challenge. In this
paper, we propose a new reliable multiclass-classifier for identifying class
labels of a satellite image in remote sensing applications. The proposed
multiclass-classifier is a generalization of a binary classifier based on the
flexible ensemble of regression trees model called Bayesian Additive Regression
Trees (BART). We used three small areas from the LANDSAT 5 TM image, acquired
on August 15, 2009 (path/row: 08/29, L1T product, UTM map projection) over
Kings County, Nova Scotia, Canada to classify the land-use. Several prediction
accuracy and uncertainty measures have been used to compare the reliability of
the proposed classifier with the state-of-the-art classifiers in remote
sensing.


title: Non-filamentary memristive switching in Pt/CuOx/Si/Pt systems

abstract:
  We report a memristive switching effect in the Pt/CuOx/Si/Pt devices prepared
by rf sputtering technique at room temperature. Different from other Cu-based
switching systems, the devices show a non-filamentary switching effect. A
gradual electroforming marked by resistance increasing and capacitance
decreasing is observed in current-voltage and capacitance characteristics. By
the Auger electron spectroscopy analysis, a model based on Cu ion and oxygen
vacancy drift, and thickness change of the SiOx layer at the CuOx/Si interface
was proposed for the memristive switching and gradual electroforming,
respectively. The present work would be meaningful for the preparation of
forming-free and homogeneous memristive devices.


title: Algebraic weighted colimits

abstract:
  In this thesis weighted colimits in 2-categories equipped with promorphisms
are studied. Such colimits include most universal constructions with counits,
like ordinary colimits in categories, weighted colimits in enriched categories,
and left Kan extensions.
  In the first chapter we recall the notion of 2-categories equipped with
promorphisms (also simply called equipments), that provide a coherent way of
adding bimodule-like morphisms to a 2-category. In the second chapter we recall
two ways of defining weighted colimits in equipments. Most important to us is
their original definition, introduced by Wood, in equipments that are endowed
with a closed structure. The second notion, of what we call pointwise weighted
colimits, was introduced by Grandis and Par\'e. It requires no extra structure
and generalises Street's notion of pointwise left Kan extensions in
2-categories. The main result of the second chapter gives a condition, on
closed equipments, under which these two notions coincide.
  In the third chapter we consider monads on equipments. The main idea of this
thesis, given in the fourth chapter, generalises the notions of lax and colax
morphisms, of algebras over a 2-monad, to notions of lax and colax
promorphisms, of algebras over a monad on an equipment. One of these, that of
right colax promorphisms, is well suited to the construction of weighted
colimits. In particular, given a monad T on an equipment K, we will show that
T-algebras, colax T-morphisms and right colax T-promorphisms form a double
category T-rcProm. Although weaker than equipments, double categories still
allow definition of weighted colimits, and our main result states that the
forgetful functor T-rcProm -> K lifts all weighted colimits whenever K is
closed, under some mild conditions on T.


title:
Electrically charged droplet: Influence of the generator configuration
  and the nature of the liquid

abstract:
  We studied how to charge droplets by induction and how to maximize this
charge. In order to aim this objective, we developed an innovative device that
avoids non-linear effects and that is able to charge liquids of different
nature. The device developed resembles a planar capacitor. The influence of the
nature of the liquid (i.e. presence of ions in solution, polarity, surface
tension and conductivity) on the charge induced was measured. We deduced that
there exists a threshold of electrical conductivity for the fluid below which
it does not charge according to the "perfect conductor" model.


title:
Test of mutually unbiased bases for six-dimensional photonic quantum
  systems

abstract:
  In quantum information, complementarity of quantum mechanical observables
plays a key role. If a system resides in an eigenstate of an observable, the
probability distribution for the values of a complementary observable is flat.
The eigenstates of these two observables form a pair of mutually unbiased bases
(MUBs). More generally, a set of MUBs consists of bases that are all pairwise
unbiased. Except for specific dimensions of the Hilbert space, the maximal sets
of MUBs are unknown in general. Even for a dimension as low as six, the
identification of a maximal set of MUBs remains an open problem, although there
is strong numerical evidence that no more than three simultaneous MUBs do
exist. Here, by exploiting a newly developed holographic technique, we
implement and test different sets of three MUBs for a single photon
six-dimensional quantum state (a qusix), encoded either in a hybrid
polarization-orbital angular momentum or a pure orbital angular momentum
Hilbert space. A close agreement is observed between theory and experiments.
Our results can find applications in state tomography, quantitative
wave-particle duality, quantum key distribution and tests on complementarity
and logical indeterminacy.


title: Luminosity measurement at ILC

abstract:
  In this paper we describe a method of luminosity measurement at the future
linear collider ILC that estimates and corrects for the impact of the dominant
sources of systematic uncertainty originating from the beam-induced effects and
the background from physics processes. Based on the relativistic kinematics of
the collision frame of the Bhabha process, the beam-beam related uncertainty is
reduced to a permille independently of the precision with which the beam
parameters are known. With the specific event selection, different from the
isolation cuts based on topology of the signal used at LEP, combined with the
corrective methods we introduce, the overall systematic uncertainty in the peak
region above 80% of the nominal center-of-mass energy meets the physics
requirements to be at the few permille level at all ILC energies.


title: Interference mechanism of seemingly superluminal tunnelling

abstract:
  Apparently 'superluminal' transmission, e.g., in quantum tunnelling and its
variants, occurs via a subtle interference mechanism which allows
reconstruction of the entire spacial shape of a wave packet from its front
tail. It is unlikely that the effect could be described adequately in simpler
terms.


title:
Monolayer MoS2: trigonal warping, "\Gamma-valley", and spin-orbit
  coupling effects

abstract:
  We use a combined ab-initio calculations and k.p theory based approach to
derive a low-energy effective Hamiltonian for monolayer MoS2 at the K point of
the Brillouin zone. It captures the features which are present in
first-principles calculations but not explained by the theory of Xiao et al.
[Phys Rev Lett 108, 196802 (2012)], namely the trigonal warping of the valence
and conduction bands, the electron-hole symmetry breaking, and the
spin-splitting of the conduction band. We also consider other points in the
Brillouin zone which might be important for transport properties. Our findings
lead to a more quantitative understanding of the properties of this material in
the ballistic limit.


title:
The Effects of Galaxy Shape and Rotation on the X-ray Haloes of
  Early-Type Galaxies

abstract:
  We present a detailed diagnostic study of the observed temperatures of the
hot X-ray coronae of early-type galaxies. By extending the investigation
carried out in Pellegrini (2011) with spherical models, we focus on the
dependence of the energy budget and temperature of the hot gas on the galaxy
structure and internal stellar kinematics. By solving the Jeans equations we
construct realistic axisymmetric three-component galaxy models (stars, dark
matter halo, central black hole) with different degrees of flattening and
rotational support. The kinematical fields are projected along different lines
of sight, and the aperture velocity dispersion is computed within a fraction of
the circularized effective radius. The model parameters are chosen so that the
models resemble real ETGs and lie on the Faber-Jackson and Size-Luminosity
relations. For these models we compute T_* (the stellar heating contribution to
the gas injection temperature) and T_gm (the temperature equivalent of the
energy required for the gas escape). In particular, different degrees of
thermalisation of the ordered rotational field of the galaxy are considered. We
find that T_* and T_gm can vary only mildly due to a pure change of shape.
Galaxy rotation instead, when not thermalised, can lead to a large decrease of
T_*; this effect can be larger in flatter galaxies that can be more
rotationally supported. Recent temperature measurements T_x, obtained with
Chandra, are larger than, but close to, the T_* values of the models, and show
a possible trend for a lower T_x in flatter and more rotationally supported
galaxies; this trend can be explained by the lack of thermalisation of the
whole stellar kinetic energy. Flat and rotating galaxies also show lower L_x
values, and then a lower gas content, but this is unlikely to be due to the
small variation of T_gm found here for them.


title: Hubiness, length, crossings and their relationships in dependency trees

abstract:
  Here tree dependency structures are studied from three different
perspectives: their degree variance (hubiness), the mean dependency length and
the number of dependency crossings. Bounds that reveal pairwise dependencies
among these three metrics are derived. Hubiness (the variance of degrees) plays
a central role: the mean dependency length is bounded below by hubiness while
the number of crossings is bounded above by hubiness. Our findings suggest that
the online memory cost of a sentence might be determined not just by the
ordering of words but also by the hubiness of the underlying structure. The 2nd
moment of degree plays a crucial role that is reminiscent of its role in large
complex networks.


title: Heavy Quarkonium moving in a Quark-Gluon Plasma

abstract:
  By means of effective field theory techniques, we study the modifications of
some properties of weakly coupled heavy quarkonium states propagating through a
quark-gluon plasma at temperatures much smaller than the heavy quark mass, m_Q.
Two different cases are considered, corresponding to two different hierarchies
between the typical size of the bound state, r, the binding energy, E, the
temperature, T, and the screening mass, m_D. The first case corresponds to the
hierarchy m_Q >> 1/r >> T >> E >> m_D, relevant for moderate temperatures, and
the second one to the hierarchy m_Q >> T >> 1/r, m_D >> E, relevant for
studying the dissociation mechanism. In the first case we determine the
perturbative correction to the binding energy and to the decay width of states
with arbitrary angular momentum, finding that the width is a decreasing
function of the velocity. A different behavior characterizes the second
kinematical case, being the width of s-wave states a non-monotonic function of
the velocity, increasing at moderate velocities and decreasing in the
ultra-relativistic limit. We obtain a simple analytical expression of the decay
width for T >> 1/r >> m_D >> E at moderate velocities, and we derive the s-wave
spectral function for the more general case T >> 1/r, m_D >> E. A brief
discussion of the possible experimental signatures as well as a comparison with
the relevant lattice data are also presented.


title:
Thermodynamic stability of alkali metal/zinc double-cation borohydrides
  at low temperatures

abstract:
  We study the thermodynamic stability at low temperatures of a series of
alkali metal/zinc double-cation borohydrides, including LiZn(BH$_4$)$_3$,
LiZn$_2$(BH$_4$)$_5$, NaZn(BH$_4$)$_3$, NaZn$_2$(BH$_4$)$_5$, KZn(BH$_4$)$_3$,
and KZn$_2$(BH$_4$)$_5$. While LiZn$_2$(BH$_4$)$_5$, NaZn(BH$_4$)$_3$,
NaZn$_2$(BH$_4$)$_5$ and KZn(BH$_4$)$_3$ were recently synthesized,
LiZn(BH$_4$)$_3$ and KZn$_2$(BH$_4$)$_5$ are hypothetical compounds. Using the
minima-hopping method, we discover two new lowest-energy structures for
NaZn(BH$_4$)$_3$ and KZn$_2$(BH$_4$)$_5$ which belong to the $C2/c$ and $P2$
space groups, respectively. These structures are predicted to be both
thermodynamically stable and dynamically stable, implying that their existence
may be possible. On the other hand, the lowest-energy $P1$ structure of
LiZn(BH$_4$)$_3$ is predicted to be unstable, suggesting a possible reason
elucidating why this compound has not been experimentally identified. In
exploring the low-energy structures of these compounds, we find that their
energetic ordering is sensitive to the inclusion of the van der Waals
interactions. We also find that a proper treatment of these interactions, e.g.,
as given by a non-local density functional such as vdW-DF2, is necessary to
address the stability of the low-energy structures of these compounds.


title: An Exponential F(R) Dark Energy Model

abstract:
  We present an exponential $F(R)$ modified gravity model in the Jordan and the
Einstein frame. We use a general approach in order to investigate and
demonstrate the viability of the model. Apart from the general features that
this models has, which actually render it viable at a first step, we address
the issues of finite time singularities, Newton's law corrections and the
scalaron mass. As we will evince, the model passes these latter two tests
successfully and also has no finite time singularities, a feature inherent to
other well studied exponential models.


title: On the controllability of the non-isentropic 1-D Euler equation

abstract:
  In this paper, we examine the question of the boundary controllability of the
one-dimensional non-isentropic Euler equation for compressible polytropic gas,
in the context of weak entropy solutions. We consider the system in Eulerian
coordinates and the one in Lagrangian coordinates. We obtain for both systems a
result of controllability toward constant states (with the limitation $\gamma <
5/3$ on the adiabatic constant for the Lagrangian system). The solutions that
we obtain remain of small total variation in space if the initial condition is
itself of sufficiently small total variation.


title: Interactive Realizability, Monads and Witness Extraction

abstract:
  In this dissertation we collect some results about "interactive
realizability", a realizability semantics that extends the
Brouwer-Heyting-Kolmogorov interpretation to (sub-)classical logic, more
precisely to first-order intuitionistic arithmetic (Heyting Arithmetic, HA)
extended by the law of the excluded middle restricted to simply existential
formulas formulas (EM1), a system motivated by its interest in proof mining.
  We describe the interactive interpretation of a classical proof involving
real numbers. The statement we prove is a simple but non-trivial fact about
points in the real plane. The proof employs EM1 to deduce properties of the
ordering on the real numbers, which is undecidable and thus problematic from a
constructive point of view.
  We present a new set of reductions for derivations in natural deduction that
can extract witnesses from closed derivations of simply existential formulas in
HA + EM1. The reduction we present are inspired by the informal idea of
learning by making falsifiable hypothesis and checking them, and by the
interactive realizability interpretation. We extract the witnesses directly
from derivations in HA + EM1 by reduction, without encoding derivations by a
realizability interpretation.
  We give a new presentation of interactive realizability with a more explicit
syntax. We express interactive realizers by means of an abstract framework that
applies the monadic approach used in functional programming to modified
realizability, in order to obtain less strict notions of realizability that are
suitable to classical logic. In particular we use a combination of the state
and exception monads in order to capture the learning-from-mistakes nature of
interactive realizers.


title:
Free energy versus internal energy potential for heavy quark systems at
  finite temperature

abstract:
  Using the QCD sum rule with its operator product expansion reliably estimated
from lattice calculations for the pressure and energy density of the
quark-gluon plasma, we calculate the strength of the wave function of J/psi at
the origin and find that it decreases with temperature above the transition
temperature. This result is shown to follow exactly that obtained from the
solution of the Schr\"odingier equation for a charm and anticharm quark pair
using the free energy from lattice calculations as the potential and is in
sharp contrast to that using the deeper potential associated with the internal
energy, which shows an enhanced strength of the J/psi wave function at the
origin. Our result thus has resolved the long-standing question of whether the
free energy potential or the internal energy potential should be used in
analyzing the spectrum of heavy quark systems at finite temperature.


title: Non-equilibrium photon production arising from the chiral mass shift

abstract:
  We investigate the photon emission arising from the shift of the
quark/antiquark masses during the chiral phase transition in the early stage of
ultrarelativistic heavy-ion collisions. As this mass shift leads to spontaneous
creation of quark-antiquark pairs and thus contributes to the formation of the
quark-gluon plasma, our investigations are relevant in the context of
finite-lifetime effects on the photon emission from the latter. Earlier
investigations on this topic by Boyanovsky et al. were plagued by a UV
divergent contribution from the vacuum polarization and the non-integrability
of the remaining contributions in the ultraviolet domain. In contrast to these
investigations, we do not consider the photon number-density at finite times
but for free asymptotic states obtained by an adiabatic switching of the
electromagnetic interaction according to the Gell-Mann and Low theorem. This
approach eliminates possible unphysical contributions from the vacuum
polarization and renders the resulting photon spectra integrable in the
ultraviolet domain. It is emphasized that the consideration of free asymptotic
states is indeed crucial to obtain such physically reasonable results.


title: Morphological instability of core-shell metallic nanoparticles

abstract:
  Bimetallic nanoparticles (often known as nanoalloys) with core-shell
arrangement are of special interest in several applications, such as in optics,
catalysis, magnetism and biomedicine. Despite wide interest in applications,
the physical factors stabilizing the structures of these nanoparticles are
still unclear to a great extent, especially for what concerns the relationship
between geometric structure and chemical ordering pattern. Here
global-optimization searches are performed in order to single out the most
stable chemical ordering patterns corresponding to the most important geometric
structures, for a series of weakly miscible systems, including AgCu, AgNi, AgCo
and AuCo. The calculations show that (i) the overall geometric structure of the
nanoalloy and the shape and placement of its inner core are strictly
correlated; (ii) centered cores can be obtained in icosahedral nanoparticles
but not in crystalline or decahedral ones, in which asym- metric quasi-Janus
morphologies form; (iii) in icosahedral nanoparticles, when the core exceeds a
critical size, a new type of morphological instability develops, making the
core asymmetric and extending it to- wards the nanoparticle surface; (iv)
multi-center patterns can be obtained in polyicosahedral nanoalloys. Analogies
and differences between the instability of the core in icosahedral nanoalloys
and the Stranski- Krastanov instability occurring in thin-film growth are
discussed. All these issues are crucial for designing strategies to achieve
effective coatings of the cores.


title:
Infinitesimal invariants for cycles modulo algebraic equivalence and
  1-cycles on Jacobians

abstract:
  We construct an infinitesimal invariant for cycles in a family with
cohomology class in the total space lying in a given level of the Leray
filtration. This infinitesimal invariant detects cycles modulo algebraic
equivalence in the fibers. We apply this construction to the Ikeda family,
which gives optimal results for the Beauville decomposition of the 1-cycle of a
very general plane curve in its Jacobian.


title:
The AB equations and the $\bar\partial$-dressing method in
  semi-characteristic coordinates

abstract:
  The dressing method based on the $2\times2$ matrix $\bar\partial$-problem is
generalized to study the canonical form of AB equations. The soliton solutions
for the AB equations are given by virtue of the properties of Cauchy matrix.
Asymptotic behaviors of the $N$-soliton solution are discussed.


title: Nonabelian higher derived brackets

abstract:
  Let M be a graded Lie algebra, together with graded Lie subalgebras L and A
such that as a graded space M is the direct sum of L and A, and A is abelian.
Let D be a degree one derivation of M squaring to zero and sending L into
itself, then Voronov's construction of higher derived brackets associates to D
a L-infinity structure on A[-1]. It is known, and it follows from the results
of this paper, that the resulting L-infinity algebra is a weak model for the
homotopy fiber of the inclusion of differential graded Lie algebras i : (L,D,[,
]) -> (M,D,[, ]). We prove this fact using homotopical transfer of L-infinity
structures, in this way we also extend Voronov's construction when the
assumption A abelian is dropped: the resulting formulas involve Bernoulli
numbers. In the last section we consider some example and some further
application.


title: First results from the Herschel Gould Belt Survey in Taurus

abstract:
  The whole of the Taurus region (a total area of 52 sq. deg.) has been
observed by the Herschel SPIRE and PACS instruments at wavelengths of 70, 160,
250, 350 and 500 {\mu}m as part of the Herschel Gould Belt Survey. In this
paper we present the first results from the part of the Taurus region that
includes the Barnard 18 and L1536 clouds. A new source-finding routine, the
Cardiff Source-finding AlgoRithm (CSAR), is introduced, which is loosely based
on CLUMPFIND, but that also generates a structure tree, or dendrogram, which
can be used to interpret hierarchical clump structure in a complex region.
Sources were extracted from the data using the hierarchical version of CSAR and
plotted on a mass-size diagram. We found a hierarchy of objects with sizes in
the range 0.024-2.7 pc. Previous studies showed that gravitationally bound
prestellar cores and unbound starless clumps appeared in different places on
the mass-size diagram. However, it was unclear whether this was due to a lack
of instrumental dynamic range or whether they were actually two distinct
populations. The excellent sensitivity of Herschel shows that our sources fill
the gap in the mass-size plane between starless and pre-stellar cores, and
gives the first clear supporting observational evidence for the theory that
unbound clumps and (gravitationally bound) prestellar cores are all part of the
same population, and hence presumably part of the same evolutionary sequence
(c.f. Simpson et al. 2011).


title:
Massive S-matrix of AdS_3 x S^3 x T^4 superstring theory with mixed
  3-form flux

abstract:
  The type IIB supergravity AdS_3 x S^3 x T^4 background with mixed RR and NSNS
3-form fluxes is a near-horizon limit of a non-threshold bound state of D5-D1
and NS5-NS1 branes. The corresponding superstring world-sheet theory is
expected to be integrable, opening the possibility of computing its exact
spectrum for any values of the coefficient q of the NSNS flux and the string
tension. In arXiv:1303.1447 we have found the tree-level S-matrix for the
massive BMN excitations in this theory, which turned out to have a simple
dependence on q. Here, by analyzing the constraints of symmetry and
integrability, we propose an exact massive-sector dispersion relation and the
exact S-matrix for this world-sheet theory. The S-matrix generalizes its recent
construction in the q=0 case in arXiv:1303.5995.


title: Some dynamical properties of pseudo-automorphisms in dimension 3

abstract:
  Let $X$ be a compact K\"ahler manifold of dimension 3 and let $f:X\rightarrow
X$ be a pseudo-automorphism. Under the mild condition that
$\lambda_1(f)^2>\lambda_2(f)$, we prove the existence of invariant positive
closed $(1,1)$ and $(2,2)$ currents, and we also discuss the (still open)
problem of intersection of such currents. We prove a weak equidistribution
result (which is essentially known in the literature) for Green $(1,1)$
currents of meromorphic selfmaps, not necessarily 1-algebraic stable, of a
compact K\"ahler manifold of arbitrary dimension; and discuss how a stronger
equidistribution result may be proved for pseudo-automorphisms in dimension 3.
As a byproduct, we show that the intersection of some dynamically related
currents are well-defined with respect to our definition here, even though not
obviously to be seen so using the usual criteria.


title: Evidence for a Bose-Einstein condensate of excitons

abstract:
  The demonstration of Bose-Einstein condensation in atomic gases at
micro-Kelvin temperatures is a striking landmark while its evidence for
semiconductor excitons still is a long-awaited milestone. This situation was
not foreseen because excitons are light-mass boson-like particles with a
condensation expected to occur around a few Kelvins. An explanation can be
found in the underlying fermionic nature of excitons which rules their
condensation. Precisely, it was recently predicted that, at accessible
experimental conditions, the exciton condensate shall be "gray" with a dominant
dark part coherently coupled to a weak bright component through fermion
exchanges. This counter-intuitive quantum condensation, since excitons are
mostly known for their optical activity, directly follows from the excitons
internal structure which has an optically inactive, i.e., dark, ground state.
Here, we report compelling evidence for such a "gray" condensate. We use an
all-optical approach in order to produce microscopic traps which confine a
dense exciton gas that yet exhibits an anomalously weak photo-emission at
sub-Kelvin temperatures. This first fingerprint for a "gray" condensate is then
confirmed by the macroscopic spatial coherence and the linear polarization of
the weak excitonic photoluminescence emitted from the trap, as theoretically
predicted.


title: Hyperstructures on Lie algebroids

abstract:
  We define hypersymplectic structures on Lie algebroids recovering, as
particular cases, all the classical results and examples of hypersymplectic
structures on manifolds. We prove a 1-1 correspondence theorem between
hypersymplectic structures and (pseudo-)hyperk\"{a}hler structures. We show
that the hypersymplectic framework is very rich in already known compatible
pairs of tensors such as Poisson-Nijenhuis, $\Omega N$ and $P \Omega$
structures.


title:
A multigrid method for the Helmholtz equation with optimized coarse grid
  corrections

abstract:
  We study the convergence of multigrid schemes for the Helmholtz equation,
focusing in particular on the choice of the coarse scale operators. Let G_c
denote the number of points per wavelength at the coarse level. If the coarse
scale solutions are to approximate the true solutions, then the oscillatory
nature of the solutions implies the requirement G_c > 2. However, in examples
the requirement is more like G_c >= 10, in a trade-off involving also the
amount of damping present and the number of multigrid iterations. We conjecture
that this is caused by the difference in phase speeds between the coarse and
fine scale operators. Standard 5-point finite differences in 2-D are our first
example. A new coarse scale 9-point operator is constructed to match the fine
scale phase speeds. We then compare phase speeds and multigrid performance of
standard schemes with a scheme using the new operator. The required G_c is
reduced from about 10 to about 3.5, with less damping present so that waves
propagate over > 100 wavelengths in the new scheme. Next we consider extensions
of the method to more general cases. In 3-D comparable results are obtained
with standard 7-point differences and optimized 27-point coarse grid operators,
leading to an order of magnitude reduction in the number of unknowns for the
coarsest scale linear system. Finally we show how to include PML boundary
layers, using a regular grid finite element method. Matching coarse scale
operators can easily be constructed for other discretizations. The method is
therefore potentially useful for a large class of discretized high-frequency
Helmholtz equations.


title: Decidability of Weak Simulation on One-counter Nets

abstract:
  One-counter nets (OCN) are Petri nets with exactly one unbounded place. They
are equivalent to a subclass of one-counter automata with only a weak test for
zero. We show that weak simulation preorder is decidable for OCN and that weak
simulation approximants do not converge at level omega, but only at omega^2. In
contrast, other semantic relations like weak bisimulation are undecidable for
OCN, and so are weak (and strong) trace inclusion.


title:
Enhancement of the superconducting transition temperature of MgB2 by
  proximity effect of d0 ferromagnet

abstract:
  Heterostructures of superconducting and ferromagnetic materials are of
fundamental interest because of the mutual interaction of antagonistic kinds of
ordering at the S-F interface. Normally, the superconducting transition
temperature Tc should be strongly suppressed at the S-F interface owing to the
penetration of Cooper pairs into the ferromagnetic side. Nevertheless,
constructive interactions between S and F orders have been suggested to occur
via the modification of ferromagnetic order by the superconducting state. This
may induce an inhomogeneous magnetic state, often called a cryptoferromagnetic
state, and the relevant domain wall effect, which will lead to a local decrease
of the pair-breaking parameter. However, the domain wall effect, even if it
exists, is quite subtle from the experimental view point and is normally
difficult to observe. Here we show that the defect-related d0 ferromagnetism in
MgO and the superconductivity in MgB2 do not antagonize, but rather enhance the
superconducting transition temperature Tc to any significant degree. We found
in superconducting MgB2-d0 ferromagnetic MgO composites that the
superconducting transition proceeds in two steps. The first at the S-F
interface, between 110-120 K, then in the rest of the bulk at 39 K, which is
the Tc of single phase MgB2 superconductor. Moreover, the additional transition
emerges at 60 K at the S-F interface especially in the ferromagnetic side,
showing a spin-glass-like magnetic state. Our findings reveal that the
proximity effect in the superconductor-d0 ferromagnet heterostructures will
provide the knowledge and basis to enhance the Tc value of the existing
superconductors.


title:
Mean number of encounters of N random walkers and intersection of
  strongly anisotropic fractals

abstract:
  We study the mean number of encounters up to time t, E_N(t), taking place in
a subspace with dimension d* of a d-dimensional lattice, for N independent
random walkers starting simultaneously from the same origin. E_N is first
evaluated analytically in a continuum approximation and numerically through
Monte Carlo simulations in one and two dimensions. Then we introduce the notion
of the intersection of strongly anisotropic fractals and use it to calculate
the long-time behaviour of E_N.


title:
Beyond relativistic mean-field studies of low-lying states in
  neutron-deficient krypton isotopes

abstract:
  Neutron-deficient krypton isotopes are of particular interest due to the
coexistence of oblate and prolate shapes in low-lying states and the transition
of ground-state from one dominate shape to another as a function of neutron
number. A detailed interpretation of these phenomena in neutron-deficient Kr
isotopes requires the use of a method going beyond a mean-field approach that
permits to determine spectra and transition probabilities. The aim of this work
is to provide a systematic calculation of low-lying state in the even-even
68-86Kr isotopes and to understand the shape coexistence phenomenon and the
onset of large collectivity around N=40 from beyond relativistic mean-field
studies. The starting point of our method is a set of relativistic
mean-field+BCS wave functions generated with a constraint on triaxial
deformations (beta, gamma). The excitation energies and electric multipole
transition strengths of low-lying states are calculated by solving a
five-dimensional collective Hamiltonian (5DCH) with parameters determined by
the mean-field wave functions. To examine the role of triaxiality, a
configuration mixing of both particle number (PN) and angular momentum (AM)
projected axially deformed states is also carried out within the exact
generator coordinate method (GCM) based on the same energy density functional.
The energy surfaces, the excitation energies of 0^+_2, 2^+_1, 2^+_2 states, as
well as the E0 and E2 transition strengths are compared with the results of
similar 5DCH calculations but with parameters determined by the
non-relativistic mean-field wave functions, as well as with the available
data...


title: Building spanning trees quickly in Maker-Breaker games

abstract:
  For a tree T on n vertices, we study the Maker-Breaker game, played on the
edge set of the complete graph on n vertices, which Maker wins as soon as the
graph she builds contains a copy of T. We prove that if T has bounded maximum
degree, then Maker can win this game within n+1 moves. Moreover, we prove that
Maker can build almost every tree on n vertices in n-1 moves and provide
non-trivial examples of families of trees which Maker cannot build in n-1
moves.


title:
Optical and X-ray Properties of CAL 83: I. Quasi-periodic Optical and
  Supersoft Variability

abstract:
  We have studied the long-term (~ years) temporal variability of the prototype
supersoft X-ray source (SSS) CAL 83 in the LMC, using data from the MACHO and
OGLE projects. The CAL 83 light curve exhibits dramatic brightness changes of
~1 mag on timescales of ~450 days, and spends typically ~200 days in the
optical low state. Combined with archival XMM-Newton X-ray observations these
represent the most extensive X-ray/optical study to date of this system, and
reveal in much greater detail that the X-ray light curve is anti-correlated
with the optical behaviour. This is remarkably similar to the behaviour of the
"transient" SSS, RX J0513.9-6951, where the SSS outbursts recur on a timescale
of ~168 days, and also anti-correlate with the optical flux. We performed
simple blackbody fits to both high and low state X-ray spectra, and find that
the blackbody temperature and luminosity decrease when the optical counterpart
brightens. We interpret these long-term variations in terms of the limit-cycle
model of Hachisu & Kato (2003a), which provides further support for these
systems containing massive (~1.3 Msun) white dwarfs. In addition, we have
refined their orbital periods in the MACHO and OGLE-III light curves to values
of 1.047529(1) days and 0.762956(5) days for CAL 83 and RX J0513.9-6951,
respectively.


title: Line defects in the 3d Ising model

abstract:
  We investigate the properties of the twist line defect in the critical 3d
Ising model using Monte Carlo simulations. In this model the twist line defect
is the boundary of a surface of frustrated links or, in a dual description, the
Wilson line of the Z2 gauge theory. We test the hypothesis that the twist line
defect flows to a conformal line defect at criticality and evaluate numerically
the low-lying spectrum of anomalous dimensions of the local operators which
live on the defect as well as mixed correlation functions of local operators in
the bulk and on the defect.


title: NLTE water lines in Betelgeuse-like atmospheres

abstract:
  The interpretation of water lines in red supergiant stellar atmospheres has
been much debated over the past decade. The introduction of the so-called
MOLspheres to account for near-infrared "extra" absorption has been
controversial. We propose that non-LTE effects should be taken into account
before considering any extra-photospheric contribution.
  After a brief introduction on the radiative transfer treatment and the
inadequacy of classical treatments in the case of large-scale systems such as
molecules, we present a new code, based on preconditioned Krylov subspace
methods. Preliminary results suggest that NLTE effects lead to deeper water
bands, as well as extra cooling.


title:
Shadow Estimation Method for "The Episolar Constraint: Monocular Shape
  from Shadow Correspondence"

abstract:
  Recovering shadows is an important step for many vision algorithms. Current
approaches that work with time-lapse sequences are limited to simple
thresholding heuristics. We show these approaches only work with very careful
tuning of parameters, and do not work well for long-term time-lapse sequences
taken over the span of many months. We introduce a parameter-free expectation
maximization approach which simultaneously estimates shadows, albedo, surface
normals, and skylight. This approach is more accurate than previous methods,
works over both very short and very long sequences, and is robust to the
effects of nonlinear camera response. Finally, we demonstrate that the shadow
masks derived through this algorithm substantially improve the performance of
sun-based photometric stereo compared to earlier shadow mask estimation.


title: Statistical Thermodynamics for metaequilibrium or metastable states

abstract:
  We show how statistical thermodynamics can be formulated in situations in
which thermodynamics applies, while equilibrium statistical mechanics does not.
A typical case is, in the words of Landau and Lifshitz, that of partial (or
incomplete) equilibrium. One has a system of interest in equilibrium with the
environment, and measures one of its quantities, for example its specific heat,
by raising the temperature of the environment. However, within the observation
time the global system settles down to a state of apparent equilibrium, so that
the measured value of the specific heat is different from the equilibrium one.
In such cases formulae for quantities such as the effective specific heat
exist, which are provided by Fluctuation Dissipation theory. However, what is
lacking is a proof that internal energy exists, i.e., that the fundamental
differential form delta Q-delta W (difference between the heat absorbed by the
system and the work performed by it) is closed. Here we show how the
coefficients of the fundamental form can be expressed in such a way that the
closure property of the form becomes manifest, so that the first principle is
proven. We then show that the second principle too follows, and indeed as a
consequence of microscopic time--reversibility. The treatment is given in a
classical Hamiltonian setting. One has a global time--independent Hamiltonian
system constituted by the system of interest and two auxiliary ones controlling
temperature and pressure, and the occurring of a process due to a change in the
thermodynamic parameters is implemented by a suitable choice of the measure for
the initial data.


title: Nucleon excited states on the lattice

abstract:
  We study the pion-nucleon system in s-wave in the framework of lattice QCD in
order to gain new information on the nucleon excited states. We perform
simulations for $n_f =2$ mass degenerate light quarks at a pion mass of 266
MeV. The results show that including the two-particle states drastically
changes the energy levels. The variational analysis and the distillation
approach play an important role in the extraction of the energy levels. The
phase shift analysis allows to extract information on the resonance nature of
the observed states.


title: The QGP dynamics in relativistic heavy-ion collisions

abstract:
  The dynamics of partons and hadrons in relativistic nucleus-nucleus
collisions is analyzed within the novel Parton-Hadron-String Dynamics (PHSD)
transport approach, which is based on a dynamical quasiparticle model for the
partonic phase (DQPM) including a dynamical hadronization scheme. The PHSD
model reproduces a large variety of observables from SPS to LHC energies, e.g.
the quark-number scaling of elliptic flow, transverse mass and rapidity spectra
of charged hadrons, dilepton spectra, open and hidden charm production,
collective flow coefficients etc., which are associated with the observation of
a sQGP. The highlights of the latest results on collective flow are presented
and open questions/perspectives are discussed.


title:
Coherent control of phase diffusion in a Bosonic Josephson junction by
  scattering length modulation

abstract:
  By means of a temporal-periodic modulation of the s-wave scattering length, a
procedure to control the evolution of an initial atomic coherent state
associated with a Bosonic Josephson junction is presented. The scheme developed
has a remarkable advantage of avoiding the quantum collapse of the state due to
phase and number diffusion. This kind of control could prove useful for atom
interferometry using BECs, where the interactions limit the evolution time
stage within the interferometer, and where the modulation can be induced via
magnetic Feshbach resonances as recently experimentally demonstrated.


title: A Limit Theorem for Discrete Quantum Groups

abstract:
  We consider the {\it concentration functions problem} for discrete quantum
groups; we prove that if $\mathbb{G}$ is a discrete quantum group, and $\mu$ is
an irreducible state in $l^1(\mathbb{G})$, then the convolution powers $\mu^n$,
considered as completely positive maps on $c_0(\mathbb{G})$, converge to zero
in strong operator topology.


title: Non-Fermi liquid behavior in transport through Co doped Au chains

abstract:
  We calculate the conductance as a function of temperature $G(T)$ through Au
monoatomic chains containing one Co atom as a magnetic impurity, and connected
to two conducting leads with a 4-fold symmetry axis. Using the information
derived from {\it ab initio} calculations, we construct an effective model
$\Heff$ that hybridizes a 3d$^7$ quadruplet at the Co site with two 3d$^8$
triplets through the hopping of 5d$_{xz}$ and 5d$_{yz}$ electrons of Au. The
quadruplet is split by spin anisotropy due to spin-orbit coupling. Solving
$\Heff$ with the numerical renormalization group (NRG) % Wb: reverted my own
change we find that at low temperatures $G(T)=a-b \sqrt{T}$ and the ground
state impurity entropy is $\ln(2)/2$, a behavior similar to the two-channel
Kondo model. Stretching the chain leads to a non Kondo phase, with the physics
of the underscreened Kondo model at the quantum critical point.


title:
Assessing Visualization Techniques for the Search Process in Digital
  Libraries

abstract:
  In this paper we present an overview of several visualization techniques to
support the search process in Digital Libraries (DLs). The search process
typically can be separated into three major phases: query formulation and
refinement, browsing through result lists and viewing and interacting with
documents and their properties. We discuss a selection of popular visualization
techniques that have been developed for the different phases to support the
user during the search process. Along prototypes based on the different
techniques we show how the approaches have been implemented. Although various
visualizations have been developed in prototypical systems very few of these
approaches have been adapted into today's DLs. We conclude that this is most
likely due to the fact that most systems are not evaluated intensely in
real-life scenarios with real information seekers and that results of the
interesting visualization techniques are often not comparable. We can say that
many of the assessed systems did not properly address the information need of
cur-rent users.


title: On the possibility of electronic DNA nanobiochips

abstract:
  We have considered as a theoretical possibility for the development of a
nanobiochip the operation principle of which is based on measuring conductance
in single-stranded and double-stranded DNA. Calculations have demonstrated that
in the majority of cases the conductance of double-stranded nucleotides
considerably exceeds that of single-stranded ones. The results obtained are in
agreement with recent experiments on measuring the oligonucleotide conductance.
It has been shown that an electronic biochip containing 11 nucleotide pairs
will recognize approximately 97% sequences. It has also been demonstrated that
the percentage of identifiable sequences will grow with the sequence length.


title: Relationship Between Thermal Tides and Radius Excess

abstract:
  Close-in extrasolar gas giants -- the hot Jupiters -- display departures in
radius above the zero-temperature solution, the radius excess, that are
anomalously high. The radius excess of hot Jupiters follows a relatively close
relation with thermal tidal tidal torques and holds for ~ 4-5 orders of
magnitude in a characteristic thermal tidal power in such a way that is
consistent with basic theoretical expectations. The relation suggests that
thermal tidal torques determine the global thermodynamic and spin state of the
hot Jupiters. On empirical grounds, it is shown that theories of hot Jupiter
inflation that invoke a constant fraction of the stellar flux to be deposited
at great depth are, essentially, falsified.


title:
Anharmonic phonons in few layer MoS$_2$: Raman spectroscopy of ultra low
  energy compression and shear modes

abstract:
  Molybdenum disulfide (MoS$_2$) is a promising material for making
two-dimensional crystals and flexible electronic and optoelectronic devices at
the nanoscale. MoS$_2$ flakes can show high mobilities and have even been
integrated in nanocircuits . A fundamental requirement for such use is
efficient thermal transport. Electronic transport generates heat which needs to
be evacuated, more crucially so in nanostructures. Anharmonic phonon-phonon
scattering is the dominant intrinsic limitation to thermal transport in
insulators. Here, using appropriate samples, ultra-low energy Raman
spectroscopy and first principles calculations, we provide a full experimental
and theoretical description of compression and shear modes of few-layer (FL)
MoS$_2$. We demonstrate that the compression modes are strongly anharmonic with
a marked enhancement of phonon-phonon scattering as the number of layers is
reduced, most likely a general feature of nanolayered materials with weak
interlayer coupling.


title:
Quantum-orbit analysis of above threshold ionization by intense
  spatially inhomogeneous field

abstract:
  We perform a detailed analysis of above threshold ionization (ATI) in atoms
within the strong field approximation (SFA) by considering spatially
inhomogeneous monochromatic laser fields. The locally enhanced field induced by
resonance plasmons is an example for such inhomogeneous fields. We investigate
how the individual pairs of quantum orbits contribute to the photoelectron
spectra and the angular electron momentum distributions. We demonstrate that
the quantum orbits have a very different behavior in the spatially
inhomogeneous field when compared to the homogeneous field. In the case of
inhomogeneous fields, the ionization and rescattering times differ between
neighboring cycles, despite the field being monochromatic. Indeed, the
contributions from one cycle may lead to a lower cutoff, while another may
develop a higher cutoff. Within our model, we show that the ATI cutoff extends
far beyond the semiclassical cutoff, as a function of inhomogeneity strength.
Furthermore, the angular momentum distributions have very different features
compared to the homogeneous case. For the neighboring cycles, the electron
momentum distributions do not share the same absolute momentum, and they do not
have the same yield


title: Gravitational redshifts from large-scale structure

abstract:
  The recent measurement of the gravitational redshifts of galaxies in galaxy
clusters by Wojtak et al. has opened a new observational window on dark matter
and modified gravity. By stacking clusters this determination effectively used
the line of sight distortion of the cross-correlation function of massive
galaxies and lower mass galaxies to estimate the gravitational redshift profile
of clusters out to 4 Mpc/h. Here we use a halo model of clustering to predict
the distortion due to gravitational redshifts of the cross-correlation function
on scales from 1 - 100 Mpc/h. We compare our predictions to simulations and use
the simulations to make mock catalogues relevant to current and future galaxy
redshift surveys. Without formulating an optimal estimator, we find that the
full BOSS survey should be able to detect gravitational redshifts from
large-scale structure at the ~4 sigma level. Upcoming redshift surveys will
greatly increase the number of galaxies useable in such studies and the BigBOSS
and Euclid experiments should be capable of measurements with precision at the
few percent level. As has been recently pointed out by McDonald, Kaiser and
Zhao et al, other interesting effects including relativistic beaming and
transverse Doppler shift can add additional asymmetric distortions to the
correlation function. While these contributions are subdominant to the
gravitational redshift on large scales, they represent additional opportunities
to probe gravitational physics and indicate that many qualitatively new
measurements should soon be possible using large redshift surveys.


title: Counter-ions at single charged wall: Sum rules

abstract:
  For inhomogeneous classical Coulomb fluids in thermal equilibrium, like the
jellium or the two-component Coulomb gas, there exists a variety of exact sum
rules which relate the particle one-body and two-body densities. The necessary
condition for these sum rules is that the Coulomb fluid possesses good
screening properties, i.e. the particle correlation functions or the averaged
charge inhomogeneity, say close to a wall, exhibit a short-range (usually
exponential) decay. In this work, we study equilibrium statistical mechanics of
an electric double layer with counter-ions only, i.e. a globally neutral system
of equally charged point-like particles in the vicinity of a plain hard wall
carrying a fixed uniform surface charge density of opposite sign. At large
distances from the wall, the one-body and two-body counter-ion densities go to
zero slowly according to the inverse-power law. In spite of the absence of
screening, all known sum rules are shown to hold for two exactly solvable cases
of the present system: in the weak-coupling Poisson-Boltzmann limit (in any
spatial dimension larger than one) and at a special free-fermion coupling
constant in two dimensions. This fact indicates an extended validity of the sum
rules and provides a consistency check for reasonable theoretical approaches.


title:
Indication for dominating surface absorption in crystalline silicon test
  masses at 1550nm

abstract:
  The sensitivity of future gravitational wave (GW) observatories will be
limited by thermal noise in a wide frequency band. To reduce thermal noise, the
European GW observatory Einstein GW Telescope (ET) is suggested to use
crystalline silicon test masses at cryogenic temperature and a laser wavelength
of 1550nm. Here, we report a measurement of the optical loss in a prototype
high-resistivity crystalline silicon test mass as a function of optical
intensity at room temperature. The total loss from both the bulk crystal and
the surfaces was determined in a joint measurement. The characterization window
ranged from small intensities below 1W/cm^2, as planned to be used in ET, up to
21kW/cm^2. A non-linear absorption was observed for intensities above a few
kW/cm^2. In addition we have observed an intensity-independent offset that
possibly arises from absorption in the crystal surfaces. This absorption was
estimated to approx. 800 ppm/surface, which might be too high for a cryogenic
operation of a fibre-suspended silicon test mass. Such an offset was not
observed in other recent measurements that were insensitive to surface
absorption. Finally, a set of further characterization measurements is proposed
to clearly separate the contributions from the surfaces and the bulk crystal.


title:
Axion mechanism of Sun luminosity, dark matter and extragalactic
  background light

abstract:
  We show the existence of the strong inverse correlation between the temporal
variations of the toroidal component of the magnetic field in the solar
tachocline (the bottom of the convective zone) and the Earth magnetic field
(the Y-component). The possibility that the hypothetical solar axions, which
can transform into photons in external electric or magnetic fields (the inverse
Primakoff effect), can be the instrument by which the magnetic field of the Sun
convective zone modulates the magnetic field of the Earth is considered.
  We propose the axion mechanism of Sun luminosity and "solar dynamo --
geodynamo" connection, where the energy of one of the solar axion flux
components emitted in M1 transition in 57Fe nuclei is modulated at first by the
magnetic field of the solar tachocline zone (due to the inverse coherent
Primakoff effect) and after that is resonantly absorbed in the core of the
Earth, thereby playing the role of the energy modulator of the Earth magnetic
field. Within the framework of this mechanism estimations of the strength of
the axion coupling to a photon (g_{a \gamma} = 7.07e-11 1/GeV), the
axion-nucleon coupling (g_{an} = 3.20e-7), the axion-electron coupling (g_{ae}
= 5.28e-11) and the axion mass (m_a = 17eV) have been obtained. It is also
shown that the claimed axion parameters do not contradict to any known
experimental and theoretical model-independent limitations.
  We consider the effect of dark matter in the form of 17eV axions on the
extragalactic back-ground light (EBL) and find that the theoretical spectral
intensity of the EBL from decaying axions as a function of the observed
wavelength is in good agreement with the known experimental data for the near
ultraviolet, optical and near infrared bands (1500-20000 angstrom).

categories: astro-ph.SR astro-ph.CO hep-ph physics.geo-ph


title: Pulsar interpretation for the AMS-02 result

abstract:
  The AMS-02 collaboration has just published a high precision measurement of
the cosmic positron fraction $e^+/(e^- + e^+)$, which rises with energy from
$\sim 5$ GeV to $\sim 350$ GeV. The result indicates the existence of primary
electron/positron sources to account for the positron excess. In this work, we
investigate the possibility that the nearby mature pulsars are the primary
positron sources. By fitting the data we find that the positrons from a single
nearby pulsar, such as Geminga or Monogem, with the spectral index $\alpha \sim
2$ can interpret the AMS-02 result. We also investigate the possibility that
high energy positrons are generated by multiple known pulsars in the ATNF
catalogue. Such a scenario can also fit the AMS-02 data well. Future precise
measurements of fine structures in the positron spectrum would be a support to
the pulsar scenario.


title:
The hybrid B-type pulsator $\gamma$ Pegasi: mode identification and
  complex seismic modelling

abstract:
  We present interpretation of the oscillation spectrum of the early B-type
star $\gamma$ Pegasi, in which both low order p/g and high-order g-modes are
observed. Using amplitudes and phases of the photometric and radial velocity
variations, we identify/constrain the mode degree, $\ell$, for all 14 detected
frequencies. Seismic models fitting two pulsational frequencies corresponding
to the modes $\ell=0$, p$_1$ and $\ell=1$, g$_1$ were constructed. This set of
models contains those which reproduce also the empirical values of the complex
nonadiabatic parameter $f$ associated to these two mode frequencies.
Unfortunately, there are no models reproducing the values of $f$ for both
frequencies simultaneously, regardless of model atmospheres, opacity data,
chemical mixture as well as opacity enhancement in the $Z-$ and Deep Opacity
Bumps. Most probably, some modifications of the opacities in stellar interiors
are still required.


title:
Astrophysical false positives in direct imaging for exoplanets: a white
  dwarf close to a rejuvenated star

abstract:
  As is the case for all techniques involved in the research for exoplanets,
direct imaging has to take into account the probability of so-called
astrophysical false positives, which are phenomena that mimic the signature of
objects we are seeking. In this work we aim to present a case of a false
positive found during a direct imaging survey conducted with VLT/NACO. A
promising exoplanet candidate was detected around the K2-type star HD\,8049 in
July 2010.Its contrast of $\Delta H$=7.05 at 1.57 arcsec allowed us to guess
the presence of a 35 \MJup companion at 50 projected AU, for the nominal system
age and heliocentric distance.To check whether it was gravitationally bound to
the host star, as opposed to an unrelated background object, we re-observed the
system one year later and concluded a high probability of a bound system. We
also used radial velocity measurements of the host star, spanning a time range
of $\sim$ 30 yr, to constrain the companion's mass and orbital properties, as
well as to probe the host star's spectral age indicators and general spectral
energy distribution. We also obtained for the companion $U$-band imaging with
EFOSC and $NIR$ spectroscopy. Combining all these information we conclude that
the companion of HD\,8049 is a white dwarf (WD), with temperature
$T_{eff}=18800 \pm 2100$ K and mass $M_{WD}=0.56 \pm 0.08 M_{\odot}$. The
significant radial velocity trend coupled with the imaging data indicate that
the most probable orbit has a semimajor axis of about 50 AU.The discrepancy
between the age indicators suggested against a bona-fide young star. The
moderately large level of chromospheric activity and fast rotation, mimicking
the properties of a young star, might be induced by the exchange of mass with
the progenitor of the WD. This example demonstrates some of the challenges in
determining accurate age estimates and identifications of faint companions.


title:
The Wilson exact renormalization group equation and the anomalous
  dimension parameter

abstract:
  The non-linear way the anomalous dimension parameter has been introduced in
the historic first version of the exact renormalization group equation is
compared to current practice. A simple expression for the exactly marginal
redundant operator proceeds from this non-linearity, whereas in the linear
case, first order differential equations must be solved to get it. The role of
this operator in the construction of the flow equation is highlighted.


title: Interlacing Families I: Bipartite Ramanujan Graphs of All Degrees

abstract:
  We prove that there exist infinite families of regular bipartite Ramanujan
graphs of every degree bigger than 2. We do this by proving a variant of a
conjecture of Bilu and Linial about the existence of good 2-lifts of every
graph.
  We also establish the existence of infinite families of `irregular Ramanujan'
graphs, whose eigenvalues are bounded by the spectral radius of their universal
cover. Such families were conjectured to exist by Linial and others. In
particular, we prove the existence of infinite families of (c,d)-biregular
bipartite graphs with all non-trivial eigenvalues bounded by
sqrt{c-1}+sqrt{d-1}, for all c, d \geq 3.
  Our proof exploits a new technique for demonstrating the existence of useful
combinatorial objects that we call the "method of interlacing polynomials'".