title:
Topological Quantum Field Theory, Nonlocal Operators, and Gapped Phases
  of Gauge Theories

abstract:
  We revisit the role of loop and surface operators as order parameters for
gapped phases of four-dimensional gauge theories. We show that in some cases
surface operators are confined, and that this fact can be used to distinguish
phases which are not distinguished by the Wilson-'t Hooft criterion. The
long-distance behavior of loop and surface operators which are neither confined
nor screened is controlled by a 4d TQFT. We construct these TQFTs for phases
which are characterized by the presence of electrically and/or magnetically
charged condensates. Interestingly, the TQFT describing a phase with a
nonabelian monopole condensate is based on the theory of nonabelian gerbes. We
also show that in phases with a dyonic condensate the low-energy theta-angle is
quantized.


title: External definability and groups in NIP theories

abstract:
  We prove that many properties and invariants of definable groups in NIP
theories, such as definable amenability, G/G^{00}, etc., are preserved when
passing to the theory of the Shelah expansion by externally definable sets,
M^{ext}, of a model M. In the light of these results we continue the study of
the "definable topological dynamics" of groups in NIP theories. In particular
we prove the Ellis group conjecture relating the Ellis group to G/G^{00} in
some new cases, including definably amenable groups in o-minimal structures.


title:
Variational formulation of problems involving fractional order
  differential operators

abstract:
  In this work, we consider boundary value problems involving Caputo and
Riemann-Liouville fractional derivatives of order $\alpha\in(1,2)$ on the unit
interval $(0,1)$. These fractional derivatives lead to non-symmetric boundary
value problems, which are investigated from a variational point of view. The
variational problem for the Riemann-Liouville case is coercive on the space
$H_0^{\alpha/2}(0,1)$ but the solutions are less regular, whereas that for the
Caputo case involves different test and trial spaces. The numerical analysis of
these problems requires the so-called shift theorems which show that the
solutions of the variational problem are more regular. The regularity pickup
enables one to establish convergence rates of the finite element
approximations. Finally, numerical results are presented to illustrate the
error estimates.


title:
Asymptotic Behavior of Coarse-grained Models for Opinion Dynamics on
  Large Networks

abstract:
  In this paper, we propose a general mathematical framework to represent many
multi-agent signalling systems in recent works. Our goal is to apply previous
results in monotonicity to this class of systems and study their asymptotic
behavior. Hence we introduce a suitable partial order for these systems and
prove nontrivial extensions of previous results on monotonicity. We also derive
a convenient sufficient condition for a signalling system to be monotone and
test our condition on the Naming Games, NG and K-NG on complete networks both
with and without committed agents. We also give a counter example which fails
to satisfy our condition. Next we further extend our conclusions to systems on
sparse random networks. Finally we discuss several meaningful consequences of
monotonicity which narrows down the possible asymptotic behavior of signalling
systems in mathematical sociology and network science.


title: Review of the Low-Frequency 1/f Noise in Graphene Devices

abstract:
  Low-frequency noise with a spectral density that depends inversely on
frequency (f) has been observed in a wide variety of systems including current
fluctuations in resistors, intensity fluctuations in music and signals in human
cognition. In electronics, the phenomenon, which is known as 1/f noise, flicker
noise or excess noise, hampers the operation of numerous devices and circuits,
and can be a significant impediment to development of practical applications
from new materials. Graphene offers unique opportunities for studying 1/f noise
because of its 2D structure and carrier concentration tuneable over a wide
range. The creation of practical graphene-based devices will also depend on our
ability to understand and control the low-frequency 1/f noise in this material
system. Here, I review the characteristic features of 1/f noise in graphene and
few-layer graphene, and examine the implications of such noise for the
development of graphene-based electronics including high-frequency devices and
sensors.


title: Attention and Visibility in an Information Rich World

abstract:
  As the rate of content production grows, we must make a staggering number of
daily decisions about what information is worth acting on. For any flourishing
online social media system, users can barely keep up with the new content
shared by friends. How does the user-interface design help or hinder users'
ability to find interesting content? We analyze the choices people make about
which information to propagate on the social media sites Twitter and Digg. We
observe regularities in behavior which can be attributed directly to cognitive
limitations of humans, resulting from the different visibility policies of each
site. We quantify how people divide their limited attention among competing
sources of information, and we show how the user-interface design can mediate
information spread.


title: Cooperative Relaying at Finite SNR -- Role of Quantize-Map-and-Forward

abstract:
  Quantize-Map-and-Forward (QMF) relaying has been shown to achieve the optimal
diversity-multiplexing trade-off (DMT) for arbitrary slow fading full-duplex
networks as well as for the single-relay half-duplex network. A key reason for
this is that quantizing at the noise level suffices to achieve the cut-set
bound approximately to within an additive gap, without any requirement of
instantaneous channel state information (CSI). However, DMT only captures the
high SNR performance and potentially, limited CSI at the relay can improve
performance at moderate SNRs. In this work we propose an optimization framework
for QMF relaying over slow fading channels. Focusing on vector Gaussian
quantizers, we optimize the outage probability for the full-duplex and
half-duplex single relay by finding the best quantization level and relay
schedule according to the available CSI at the relays. For the N-relay diamond
network, we derive an universal quantizer that sharpens the additive
approximation gap of QMF from the conventional \Theta(N) bits/s/Hz to
\Theta(log(N)) bits/s/Hz using only network topology information. Analytical
solutions to channel-aware optimal quantizers for two-relay and symmetric
N-relay diamond networks are also derived. In addition, we prove that suitable
hybridizations of our optimized QMF schemes with Decode-Forward (DF) or Dynamic
DF protocols provide significant finite SNR gains over the individual schemes.


title: Universal thermopower of bad metals

abstract:
  "Bad metals" have a large linear resistivity at high-T that is universally
seen in oxides close to the Mott-Hubbard insulating phase. They also have an
universal thermopower alpha(T): (i) at very low doping (lightly doped) alpha(T)
has a pronounced low-T peak that shifts to higher-T with doping; (ii) at
moderate doping (underdoped) alpha(T) has a small low-T peak that shifts to
lower-T with doping and has a high-T sign change; and (iii) at the highest
doping (overdoped) alpha(T) is negative and depends monotonically on T. Here we
show that the simplified Hubbard model provides an easy to understand
description of this phenomena due to the universal form for the chemical
potential versus T for doped Mott insulators and the applicability of the
Kelvin formula for the thermopower.


title: Estimating 3D Signals with Kalman Filter

abstract:
  In this paper, the standard Kalman filter was implemented to denoise the
three dimensional signals affected by additive white Gaussian noise (AWGN), we
used fast algorithm based on Laplacian operator to measure the noise variance
and a fast median filter to predict the state variable. The Kalman algorithm is
modeled by adjusting its parameters for better performance in both filtering
and in reducing the computational load while conserving the information
contained in the signal


title:
Prediction of kinase inhibitor response using activity profiling,
  in-vitro screening, and elastic net regression

abstract:
  Many kinase inhibitors have been approved as cancer therapies. Recently,
libraries of kinase inhibitors have been extensively profiled, thus providing a
map of the strength of action of each compound on a large number of its
targets. These profiled libraries define drug-kinase networks that can predict
the effectiveness of new untested drugs and elucidate the role played by
specific kinases in different cellular systems. Predictions of drug
effectiveness based on a comprehensive network model of cellular signalling are
difficult, due to our partial knowledge of the complex biological processes
downstream of the targeted kinases. We have developed the Kinase Inhibitors
Elastic Net (KIEN) method, which integrates information contained in
drug-kinase networks with in vitro screening. The method uses the in vitro cell
response of single drugs and drug pair combinations as a training set to build
linear and nonlinear regression models. Besides predicting the effectiveness of
untested drugs, the method identifies sets of kinases that are statistically
associated to drug sensitivity in a given cell line. We compare different
versions of the method, which is based on a regression technique known as
elastic net. Data from two-drug combinations leads to predictive models, and
predictivity can be improved by applying logarithmic transformation to the
data. The method is applied to the A549 lung cancer cell line. A pathway
enrichment analysis of the set of kinases identified by the method shows that
axon guidance, activation of Rac, and semaphorin interactions pathways are
associated to a selective response to therapeutic intervention in this cell
line.


title: An extension of the Hajnal-Szemeredi theorem to directed graphs

abstract:
  Hajnal and Szemeredi proved that every graph G with |G|=ks and minimum degree
at least k(s-1) contains k vertex disjoint s-cliques; moreover this degree
bound is optimal. We extend their theorem to directed graphs by showing that
every directed graph D with |D|=ks and minimum (total) degree at least
2k(s-1)-1 contains k vertex disjoint transitive tournaments on s vertices. Our
result implies the Hajnal-Szemeredi Theorem, and the degree bound is optimal.
We also make some conjectures regarding even more general results for
multigraphs and partitioning into other tournaments. One of these conjectures
is supported by an asymptotic result.


title: Global interactions, information flow, and chaos synchronization

abstract:
  We investigate the relationship between the emergence of chaos
synchronization and the information flow in dynamical systems possessing
homogeneous or heterogeneous global interactions whose origin can be external
(driven systems) or internal (autonomous systems). By employing general models
of coupled chaotic maps for such systems, we show that the presence of a
homogeneous global field, either external or internal, for all times is not
indispensable for achieving complete or generalized synchronization in a system
of chaotic elements. Complete synchronization can also appear with
heterogeneous global fields; it does not requires the simultaneous sharing of
the field by all the elements in a system. We use the normalized mutual
information and the information transfer between global and local variables to
characterize complete and generalized synchronization. We show that these
information measures can characterize both types of synchronized states and
also allow to discern the origin of a global interaction field. A
synchronization state emerges when a sufficient amount of information provided
by a field is shared by all the elements in the system, on the average over
long times. Thus, the maximum value of the top-down information transfer can be
used as a predictor of synchronization in a system, as a parameter is varied.


title:
Density dependent magnetic field and the equation of state of hyperonic
  matter

abstract:
  We are interested on the effects, caused by strong variable density dependent
magnetic fields, on hyperonic matter, its symmetry energy, equations of state
and mass-radius relations. The inclusion of the anomalous magnetic moment of
the particles involved in a stellar system is performed, and some results are
compared with the cases that do not take this correction under consideration.
The Lagrangian density used follows the nonlinear Walecka model plus the
leptons subjected to an external magnetic field.


title:
Electric Dipole Polarizability in ${}^{208}$Pb: insights from the
  Droplet Model

abstract:
  We study the electric dipole polarizability $\alpha_D$ in ${}^{208}$Pb based
on the predictions of a large and representative set of relativistic and
non-relativistic nuclear mean field models. We adopt the droplet model as a
guide to better understand the correlations between $\alpha_D$ and other
isovector observables. Insights from the droplet model suggest that the product
of $\alpha_D$ and the nuclear symmetry energy at saturation density $J$ is much
better correlated with the neutron skin thickness $\Delta r_{np}$ of
${}^{208}$Pb than the polarizability alone. Correlations of $\alpha_D J$ with
$\Delta r_{np}$ and with the symmetry energy slope parameter $L$ suggest that
$\alpha_D J$ is a strong isovector indicator. Hence, we explore the possibility
of constraining the isovector sector of thenuclear energy density functional by
comparing our theoretical predictions against measurements of both $\alpha_D$
and the parity-violating asymmetry in ${}^{208}$Pb. We find that the recent
experimental determination of $\alpha_D$ in ${}^{208}$Pb in combination with
the range for the symmetry energy at saturation density $J=[31\pm (2)_{\rm
est.}]$\,MeV suggests $\Delta r_{np}({}^{208}{\rm Pb}) = 0.165 \pm (0.009)_{\rm
exp.} \pm (0.013)_{\rm theo.} \pm (0.021)_{\rm est.} {\rm fm}$ and $L= 43
\pm(6)_{\rm exp.} \pm (8)_{\rm theo.}\pm(12)_{\rm est.}$ MeV.


title:
Realistic and verifiable coherent control of excitonic states in a light
  harvesting complex

abstract:
  We explore the feasibility of coherent control of excitonic dynamics in light
harvesting complexes, analyzing the limits imposed by the open nature of these
quantum systems. We establish feasible targets for phase and phase/amplitude
control of the electronically excited state populations in the
Fenna-Mathews-Olson (FMO) complex and analyze the robustness of this control
with respect to orientational and energetic disorder, as well as decoherence
arising from coupling to the protein environment. We further present two
possible routes to verification of the control target, with simulations for the
FMO complex showing that steering of the excited state is experimentally
verifiable either by extending excitonic coherence or by producing novel states
in a pump-probe setup. Our results provide a first step toward coherent control
of these complex biological quantum systems in an ultrafast spectroscopy setup.


title:
Dispersive Decay for the 1D Klein-Gordon Equation with Variable
  Coefficient Nonlinearities

abstract:
  We study the 1D Klein-Gordon equation with variable coefficient nonlinearity.
This problem exhibits an interesting resonant interaction between the spatial
frequencies of the nonlinear coefficients and the temporal oscillations of the
solutions. In the case when only the cubic coefficients are variable we prove
dispersive decay and smoothness of the solution in weighted spaces with the
help of quadratic and cubic normal-forms transformations. In the case of cubic
interactions these normal forms appear to be novel.


title:
Grothendieck's theorem for absolutely summing multilinear operators is
  optimal

abstract:
  Grothendieck's theorem asserts that every continuous linear operator from
$\ell_{1}$ to $\ell_{2}$ is absolutely $\left( 1;1\right) $-summing. In this
note we prove that the optimal constant $g_{m}$ so that every continuous
$m$-linear operator from $\ell_{1}\times\cdots\times\ell_{1}$ to $\ell_{2}$ is
absolutely $\left( g_{m};1\right) $-summing is $\frac{2}{m+1}$. We also show
that if $g_{m}<\frac{2}{m+1}$ there is $\mathfrak{c}$ dimensional linear space
composed by continuous non absolutely $\left( g_{m};1\right) $-summing
$m$-linear operators from $\ell_{1}\times\cdots\times\ell_{1}$ to $\ell_{2}.$
In particular, our result solves (in the positive) a conjecture posed by A.T.
Bernardino in 2011.


title: Stable He$^-$ can exist in a strong magnetic field

abstract:
  The existence of bound states of the system $(\al,e,e,e)$ in a magnetic field
$B$ is studied using the variational method. It is shown that for $B \gtrsim
0.13\,{\rm a.u.}$ this system gets bound with total energy below the one of the
$(\al,e,e)$ system. It manifests the existence of the stable He$^-$ atomic ion.
Its ground state is a spin-doublet $^2(-1)^{+}$ at $0.74\, {\rm a.u.} \gtrsim B
\gtrsim 0.13\, {\rm a.u.}$ and it becomes a spin-quartet $^4(-3)^{+}$ for
larger magnetic fields. For $0.8\, {\rm a.u.} \gtrsim B \gtrsim 0.7\, {\rm
a.u.}$ the He$^-$ ion has two (stable) bound states $^2(-1)^{+}$ and
$^4(-3)^{+}$.

categories: physics.atom-ph astro-ph.HE physics.chem-ph quant-ph


title: Do Giant Planets Survive Type II Migration?

abstract:
  Planetary migration is one of the most serious problems to systematically
understand the observations of exoplanets. We clarify that the theoretically
predicted type II migration is too fast, as well as type I migration, by
developing detailed analytical arguments in which the timescale of type II
migration is compared with the disk lifetime. In the disk-dominated regime, the
type II migration timescale is characterized by a {\it local} viscous diffusion
timescale, while the disk lifetime characterized by a {\it global} diffusion
timescale that is much longer than the local one. Even in the planet-dominated
regime where the inertia of the planet mass reduces the migration speed, the
timescale is still shorter than the disk lifetime except in the final disk
evolution stage where the total disk mass decays below the planet mass. This
suggests that most giant planets plunge into the central stars within the disk
lifetime, and it contradicts the exoplanet observations that gas giants are
piled up at $r \ga 1$AU. We examine additional processes that may arise in
protoplanetary disks: dead zones, photoevaporation of gas, and gas flow across
a gap formed by a type II migrator. Although they make the type II migration
timescale closer to the disk lifetime, we show that none of them can act as an
effective barrier for rapid type II migration with the current knowledge of
these processes. We point out that gas flow across a gap and the fraction of
the flow accreted onto the planets are uncertain and they may have a potential
to solve the problem. Much more detailed investigation for each process may be
needed to explain the observed distribution of gas giants in extrasolar
planetary systems.


title:
Astrophysical signatures of boson stars: quasinormal modes and inspiral
  resonances

abstract:
  Compact bosonic field configurations, or boson stars, are promising dark
matter candidates which have been invoked as an alternative description for the
supermassive compact objects in active galactic nuclei. Boson stars can be
comparable in size and mass to supermassive black holes and they are hard to
distinguish by electromagnetic observations. However, boson stars do not
possess an event horizon and their global spacetime structure is different from
that of a black hole. This leaves a characteristic imprint in the
gravitational-wave emission, which can be used as a discriminant between black
holes and other horizonless compact objects. Here we perform a detailed study
of boson stars and their gravitational-wave signatures in a fully relativistic
setting, a study which was lacking in the existing literature in many respects.
We construct several fully relativistic boson star configurations, and we
analyze their geodesic structure and free oscillation spectra, or quasinormal
modes. We explore the gravitational and scalar response of boson star
spacetimes to an inspiralling stellar-mass object and compare it to its black
hole counterpart. We find that a generic signature of compact boson stars is
the resonant-mode excitation by a small compact object on stable quasi-circular
geodesic motion.


title: On utility maximization with derivatives under model uncertainty

abstract:
  We consider the robust utility maximization using a static holding in
derivatives and a dynamic holding in the stock. There is no fixed model for the
price of the stock but we consider a set of probability measures (models) which
are not necessarily dominated by a fixed probability measure. By assuming that
the set of physical probability measures is convex and weakly compact, we
obtain the duality result and the existence of an optimizer.


title:
Spectral analysis of a family of symmetric, scale-invariant diffusions
  with singular coefficients and associated limit theorems

abstract:
  We discuss a family of time-reversible, scale-invariant diffusions with
singular coefficients. In analogy with the standard Gaussian theory, a
corresponding family of generalized characteristic functions provides a useful
tool for proving limit theorems resulting in non-Gaussian, scale-invariant
diffusions. We apply the generalized characteristic functions in combination
with a martingale construction to prove a simple invariance principle starting
from a spatially inhomogeneous nearest-neighbor random walk.


title:
Linear Precoder Design for MIMO Interference Channels with
  Finite-Alphabet Signaling

abstract:
  This paper investigates the linear precoder design for $K$-user interference
channels of multiple-input multiple-output (MIMO) transceivers under finite
alphabet inputs. We first obtain general explicit expressions of the achievable
rate for users in the MIMO interference channel systems. We study optimal
transmission strategies in both low and high signal-to-noise ratio (SNR)
regions. Given finite alphabet inputs, we show that a simple power allocation
design achieves optimal performance at high SNR whereas the well-known
interference alignment technique for Gaussian inputs only utilizes a partial
interference-free signal space for transmission and leads to a constant rate
loss when applied naively to finite-alphabet inputs. Moreover, we establish
necessary conditions for the linear precoder design to achieve weighted
sum-rate maximization. We also present an efficient iterative algorithm for
determining precoding matrices of all the users. Our numerical results
demonstrate that the proposed iterative algorithm achieves considerably higher
sum-rate under practical QAM inputs than other known methods.


title:
Unification of Airy structure in inelastic $\alpha$ +$^{16}$O scattering
  and $\alpha$-cluster structure with core excitation in $^{20}$Ne

abstract:
  The Airy structure of the nuclear rainbow and prerainbow in inelastic and
elastic $\alpha+^{16}$O scattering is studied with the coupled channel method
using a folding potential derived from the microscopic wave functions of
$^{16}$O. The theoretical calculations reproduce the characteristic energy
evolution of the Airy minimum of the experimental angular distributions. The
energy levels with $\alpha$-cluster structure in $^{20}$Ne are reproduced well
using the potentials determined from the analysis of scattering. It is shown
that the emergence of the $K=0_3^+$ $\alpha$-cluster band with core excitation
at 7.19 MeV in $^{20}$Ne is intimately related to the emergence of the
prerainbow and rainbow in inelastic scattering to the $^{16}$O($0^+_2$). It is
found that the $\alpha$-cluster states with core excitation, the prerainbow and
the rainbow in inelastic scattering are understood in a unified way as well as
in the case of elastic scattering.


title:
Gravitational Drainage of Thin Films of Trisiloxane-(Poly)ethoxylate
  Superspreaders

abstract:
  Gravitational drainage of vertical films supported on a wire frame of
superspreader SILWET L-77 and its cousin non-superspreader SILWET L-7607
revealed drastic differences. The superspreader films showed complicated
dynamic turbulent-like interferometric patterns in distinction from the ordered
color bands of the cousin non-superspreader which reminded those of the
ordinary surfactants. Nevertheless the superspreader films stabilized
themselves at the thickness below 50 nm and revealed an order of magnitude
longer life time before bursting compared to the cousin non-superspreader.
Notably, the superspreader revealed drastic differences from the
non-superspreader in aqueous solutions with no contact with any solid Teflon
surface. The theoretical part of the work attributed the self-stabilization of
the superspreader films to significant disjoining pressure associated with the
van der Waals repulsion of the fluffy surfaces of the film formed by long
superspreader bilayers hanging from the free surfaces. The non-superspreaders
do not possess any significant disjoining pressure in the film with thicknesses
even in the range 30-50 nm. The results show that gravitational drainage of
vertical films is a useful simple tool for measuring disjoining pressure.


abstract:
  This text is a detailed overview of the theories of W*-algebras and
noncommutative integration, up to the Falcone-Takesaki theory of noncommutative
Lp spaces over arbitrary W*-algebras, and its extension to noncommutative
Orlicz spaces. The topics under consideration include the Tomita-Takesaki
modular theory, the relative modular theory (featuring bimodules, spatial
quotients, and canonical representation), the theory of W*-dynamical systems
(featuring derivations, liouvilleans, and crossed products), noncommutative
Radon-Nikodym type theorems, and operator valued weights. We pay special
attention to abstract algebraic formulation of all properties (avoiding the
dependence on Hilbert spaces wherever it is possible), to functoriality of
canonical structures arising in the theory, and to the relationship between
commutative and noncommutative integration theories. Several new results are
proved.


title: Disjoinable Lagrangian spheres and dilations

abstract:
  We consider open symplectic manifolds which admit dilations (in the sense
previously introduced by Solomon and the author). We obtain restrictions on
collections of Lagrangian submanifolds which are pairwise disjoint (or pairwise
disjoinable by Hamiltonian isotopies) inside such manifolds. This includes the
Milnor fibres of isolated hypersurface singularities which have been stabilized
(by adding quadratic terms) sufficiently often.


title:
Reduction of conductivity and ferromagnetism induced by Ag doping in
  ZnO:Co

abstract:
  Cobalt and silver co-doping has been undertaken in ZnO thin films grown by
pulsed laser deposition in order to investigate the ferromagnetic properties in
ZnO-based diluted magnetic materials and to understand the eventual relation
between ferromagnetism and charge carriers. Hall transport measurements reveal
that Ag doping up to 5% leads to a progressive compensation of the native
n-type carriers. The magnetization curves show ferromagnetic contributions for
all samples at both 5 K and room temperature, decreasing with increasing the Ag
concentration. First principles modeling of the possible configurations of
Co-Ag defects suggest the formation of nano-clusters around interstitial Co
impurity as the origin of the ferromagnetism. The Ag co-doping results in a
decrease of the total spin of these clusters and of the Curie temperature.


title:
Power-law exponent of the Bouchaud-M\'ezard model on regular random
  network

abstract:
  We study the Bouchaud-M\'ezard model on a regular random network. By assuming
adiabaticity and independency, and utilizing the generalized central limit
theorem and the Tauberian theorem, we derive an equation that determines the
exponent of the probability distribution function of the wealth as
$x\rightarrow \infty$. The analysis shows that the exponent can be smaller than
2, while a mean-field analysis always gives the exponent as being larger than
2. The results of our analysis are shown to be good agreement with those of the
numerical simulations.


title:
Outage Exponent: A Unified Performance Metric for Parallel Fading
  Channels

abstract:
  The parallel fading channel, which consists of finite number of subchannels,
is very important, because it can be used to formulate many practical
communication systems. The outage probability, on the other hand, is widely
used to analyze the relationship among the communication efficiency,
reliability, SNR, and channel fading. To the best of our knowledge, the
previous works only studied the asymptotic outage performance of the parallel
fading channel which are only valid for a large number of subchannels or high
SNRs. In this paper, a unified performance metric, which we shall refer to as
the outage exponent, will be proposed. Our approach is mainly based on the
large deviations theory and the Meijer's G-function. It is shown that the
proposed outage exponent is not only an accurate estimation of the outage
probability for any number of subchannels, any SNR, and any target transmission
rate, but also provides an easy way to compute the outage capacity, finite-SNR
diversity-multiplexing tradeoff, and SNR gain. The asymptotic performance
metrics, such as the delay-limited capacity, ergodic capacity, and
diversity-multiplexing tradeoff can be directly obtained by letting the number
of subchannels or SNR tends to infinity. Similar to Gallager's error exponent,
a reliable function for parallel fading channels, which illustrates a
fundamental relationship between the transmission reliability and efficiency,
can also be defined from the outage exponent. Therefore, the proposed outage
exponent provides a complete and comprehensive performance measure for parallel
fading channels.


title: Active Galaxies Studied with the H.E.S.S. Observatory

abstract:
  X-ray selected BL Lac objects dominate the population of extragalactic
sources detected in the very high energy (VHE; photon energies >100GeV)
gamma-ray regime with ground-based Cherenkov Telescopes. These are not the only
extragalactic VHE emitters, however, since also other types of active galactic
nuclei (AGN) have recently been established as VHE sources as well. They
include radio galaxies, optically-selected BL Lacs, and Flat-Spectrum Radio
Quasars. Here we review the current status of the ongoing AGN studies with the
H.E.S.S. instrument, concentrating on the following main three topics: (i)
constraints on the structure of the blazar emitting zone, and on the energy
dissipation processes involved in the production of the high-energy emission in
AGN, enabled by detailed timing and spectral analysis of the H.E.S.S. data;
(ii) constraints on the extragalactic background light (EBL) using H.E.S.S.
observations of blazars, and (iii) the phenomenological picture of the
gamma-ray loud AGN population emerging from combined VHE and multi-wavelength
observations of different classes of active galaxies.


title:
Secure k-Nearest Neighbor Query over Encrypted Data in Outsourced
  Environments

abstract:
  For the past decade, query processing on relational data has been studied
extensively, and many theoretical and practical solutions to query processing
have been proposed under various scenarios. With the recent popularity of cloud
computing, users now have the opportunity to outsource their data as well as
the data management tasks to the cloud. However, due to the rise of various
privacy issues, sensitive data (e.g., medical records) need to be encrypted
before outsourcing to the cloud. In addition, query processing tasks should be
handled by the cloud; otherwise, there would be no point to outsource the data
at the first place. To process queries over encrypted data without the cloud
ever decrypting the data is a very challenging task. In this paper, we focus on
solving the k-nearest neighbor (kNN) query problem over encrypted database
outsourced to a cloud: a user issues an encrypted query record to the cloud,
and the cloud returns the k closest records to the user. We first present a
basic scheme and demonstrate that such a naive solution is not secure. To
provide better security, we propose a secure kNN protocol that protects the
confidentiality of the data, user's input query, and data access patterns.
Also, we empirically analyze the efficiency of our protocols through various
experiments. These results indicate that our secure protocol is very efficient
on the user end, and this lightweight scheme allows a user to use any mobile
device to perform the kNN query.


title:
Identifying the b quark inside a boosted hadronically decaying top quark
  using jet substructure in its center-of-mass frame

abstract:
  In this paper we study the identification of the b quark inside a boosted
hadronically decaying top quark in the center-of-mass frame of the jet. We
demonstrate that the method can be used to greatly reduce the QCD jet
background even in a very high pileup condition. The method has a much smaller
fake rate for QCD jets compared to typical b quark identification algorithms in
jets at the same signal efficiency. When combining the b quark identification
in the center-of-mass frame of the jet with jet substructure information, we
can improve the rejection rate of QCD jet background by almost an order of
magnitude while maintaining the same identification efficiency for the boosted
top quark.


title: Constraints on violations of Lorentz symmetry from Gravity Probe B

abstract:
  We use the final results from Gravity Probe B to set new upper limits on the
gravitational sector of the Standard-Model Extension, including for the first
time the coefficient associated with the time-time component of the new field
responsible for inducing local Lorentz violation in the theory.


title: Characterizing traits of coordination

abstract:
  How can one recognize coordination languages and technologies? As this report
shows, the common approach that contrasts coordination with computation is
intellectually unsound: depending on the selected understanding of the word
"computation", it either captures too many or too few programming languages.
Instead, we argue for objective criteria that can be used to evaluate how well
programming technologies offer coordination services. Of the various criteria
commonly used in this community, we are able to isolate three that are strongly
characterizing: black-box componentization, which we had identified previously,
but also interface extensibility and customizability of run-time optimization
goals. These criteria are well matched by Intel's Concurrent Collections and
AstraKahn, and also by OpenCL, POSIX and VMWare ESX.


title: The Scalar Field Source in Kaluza-Klein Theory

abstract:
  To better understand the scalar field typical of higher-dimensional
extensions of general relativity, we analyse three classes of solutions. In
all, the field equation for the extra dimension resembles the Klein-Gordon
equation, and we evaluate the strength of the source. Our results show that the
scalar field is coupled to matter, and may be regarded as generating it.


title: Toeplitz operators on Fock-Sobolev type spaces

abstract:
  In this paper, we characterize operator-theoretic properties (boundedness,
compactness, and Schatten class membership) of Toeplitz operators with positive
measure symbols on weighted Fock-Sobolev spaces of fractional order.


title:
$N$-point locality for vertex operators: normal ordered products,
  operator product expansions, twisted vertex algebras

abstract:
  In this paper we study fields satisfying $N$-point locality and their
properties. We obtain residue formulae for $N$-point local fields in terms of
derivatives of delta functions and Bell polynomials. We introduce the notion of
the space of descendants of $N$-point local fields which includes normal
ordered products and coefficients of operator product expansions. We show that
examples of $N$-point local fields include the vertex operators generating the
boson-fermion correspondences of type B, C and D-A. We apply the normal ordered
products of these vertex operators to the setting of the representation theory
of the double-infinite rank Lie algebras $b_{\infty}, c_{\infty}, d_{\infty}$.
Finally, we show that the field theory generated by $N$-point local fields and
their descendants has a structure of a twisted vertex algebra.


title:
Reveal of small alkanes and isomers using calculated core and valence
  binding energy spectra and total momentum cross sections

abstract:
  The present study revealed quantum mechanically that the C1s binding energy
spectra of the small alkanes (upto six carbons) provide a clear picture of
isomeric chemical shift in linear alkanes and branched isomers, whereas the
valence binding energy spectra contain more sensitive information regarding the
length of the carbon chains. Total momentum cross sections of the alkanes
exhibit the information of the chain length as well as constitutional isomers
of the small alkanes. The C1s binding energies of small alkanes (including
isomers) are position specific and the terminal carbons have the lowest
energies. The length of an alkane chain does not apparently affect the C1s
energies so that the terminal carbons (289.11 eV) of pentane are almost the
same as those of hexane. The valence binding energy spectra of the alkanes are
characterized by inner valence and outer valence regions which are separated by
an energy gap at approximately 17 eV. The intensities of the total momentum
cross sections of the alkanes are proportional to the number of carbons in the
alkane chains whereas the shape of the cross sections in small momentum region
of p < 0.5 a.u. indicates their branched isomers.


title:
Improving the electronic and optical properties of Carbz-PAHTDDT-based
  dyes through chemical modifications

abstract:
  To investigate geometric and electronic structure, a theoretical study is
performed on the Carbz-PAHTDDT (S9) organic dye sensitizer. This dye has a
reported promising efficiency when coupled with ferrocene-based electrolyte
composition. The present study indicated that the long-range correction to the
theoretical model in the time-dependent density functional theory is important
to produce accurate absorption wavelengths. In the present study, the chemical
structure of the original Carbz-PAHTDDT dye on the {\pi}-conjugated bridge is
also rationally changed to produce new dyes aiming at enhancing the spectral
response as a desirable property of organic dyes in DSSC application. The
theoretical studies on the new dyes have shown a significant red-shifting and
broadening of their absorption spectra.


title: Hybrid Microwave-Cavity Heat Engine

abstract:
  We propose and analyze the use of hybrid microwave cavities as quantum heat
engines. A possible realization consists of two macroscopically separated
quantum dot conductors coupled capacitively to the fundamental mode of a
microwave cavity. We demonstrate that an electrical current can be induced in
one conductor through cavity-mediated processes by heating up the other
conductor. The heat engine can reach Carnot efficiency with optimal conversion
of heat to work. When the system delivers the maximum power, the efficiency can
be a large fraction of the Carnot efficiency. The heat engine functions even
with moderate electronic relaxation and dephasing in the quantum dots. We
provide detailed estimates for the electrical current and output power using
realistic parameters.


title: Finding Regression Outliers With FastRCS

abstract:
  The Residual Congruent Subset (RCS) is a new method for finding outliers in
the linear regression setting. Like many other outlier detection procedures,
RCS searches for a subset which minimizes a criterion. The difference is that
the new criterion was designed to be insensitive to the outliers. RCS is
supported by FastRCS, a fast regression and affine equivariant algorithm which
we also detail. Both an extensive simulation study and two real data
applications show that FastRCS performs better than its competitors.


title:
The LBT Bootes Field Survey: I. The Rest-frame UV and Luminosity
  Functions and Clustering of Bright Lyman Break Galaxies at z~3

abstract:
  We present a deep LBT/LBC U-band imaging survey (9 deg2) covering the NOAO
Bootes field. A total of 14,485 Lyman Break Galaxies (LBGs) at z~3 are
selected, which are used to measure the rest-frame UV luminosity function (LF).
The large sample size and survey area reduce the LF uncertainties due to
Poisson statistics and cosmic variance by >3 compared to previous studies. At
the bright end, the LF shows excess power compared to the best-fit Schechter
function, which can be attributed to the contribution of $z\sim3$ quasars. We
compute the rest-frame near-infrared LF and stellar mass function (SMF) of z~3
LBGs based on the R-band and IRAC [4.5 micro m]-band flux relation. We
investigate the evolution of the UV LFs and SMFs between z~7 and z~3, which
supports a rising star formation history in the LBGs. We study the spatial
correlation function of two bright LBG samples and estimate their average host
halo mass. We find a tight relation between the host halo mass and the galaxy
star formation rate (SFR),which follows the trend predicted by the baryonic
accretion rate onto the halo, suggesting that the star formation in LBGs is
fueled by baryonic accretion through the cosmic web. By comparing the SFRs with
the total baryonic accretion rates, we find that cosmic star formation
efficiency is about 5%-20% and it does not evolve significantly with redshift,
halo mass, or galaxy luminosity.


title:
Tomography of plasma flows in the upper solar convection zone using
  time--distance inversion combining ridge and phase-speed filtering

abstract:
  The consistency of time--distance inversions for horizontal components of the
plasma flow on supergranular scales in the upper solar convection zone is
checked by comparing the results derived using two k--\omega filtering
procedures -- ridge filtering and phase-speed filtering -- commonly used in
time--distance helioseismology. It is shown that both approaches result in
similar flow estimates when finite-frequency sensitivity kernels are used. It
is further demonstrated that the performance of the inversion improves (in
terms of simultaneously better averaging kernel and lower noise level) when the
two approaches are combined together in one inversion. Using the combined
inversion I invert for horizontal flows in the upper 10 Mm of the solar
convection zone. The flows connected with supergranulation seem to be coherent
only in the upper ~5 Mm depth, deeper down there is a hint on change of
convection scales towards structures larger than supergranules.


title: On the fundamental groups of non-generic $\mathbb{R}$-join-type curves

abstract:
  An \emph{$\mathbb{R}$-join-type curve} is a curve in $\mathbb{C}^2$ defined
by an equation of the form \begin{equation*} a\cdot\prod_{j=1}^\ell
(y-\beta_j)^{\nu_j} = b\cdot\prod_{i=1}^m (x-\alpha_i)^{\lambda_i},
\end{equation*} where the coefficients $a$, $b$, $\alpha_i$ and $\beta_j$ are
\emph{real} numbers. For generic values of $a$ and $b$, the singular locus of
the curve consists of the points $(\alpha_i,\beta_j)$ with $\lambda_i,\nu_j\geq
2$ (so-called \emph{inner} singularities). In the non-generic case, the inner
singularities are not the only ones: the curve may also have \emph{`outer'}
singularities. The fundamental groups of (the complements of) curves having
only inner singularities are considered in \cite{O}. In the present paper, we
investigate the fundamental groups of a special class of curves possessing
outer singularities.


title: Cluster automorphisms and compatibility of cluster variables

abstract:
  In this paper, we introduce a notion of unistructural cluster algebras, for
which the set of cluster variables uniquely determines the clusters. We prove
that cluster algebras of Dynkin type and cluster algebras of rank 2 are
unistructural, then prove that if $\mathcal{A}$ is unistructural or of
Euclidean type, then $f: \mathcal{A}\to \mathcal{A}$ is a cluster automorphism
if and only if $f$ is an automorphism of the ambient field which restricts to a
permutation of the cluster variables. In order to prove this result, we also
investigate the Fomin-Zelevinsky conjecture that two cluster variables are
compatible if and only if one does not appear in the denominator of the Laurent
expansions of the other.


title:
FullSWOF_Paral: Comparison of two parallelization strategies (MPI and
  SKELGIS) on a software designed for hydrology applications

abstract:
  In this paper, we perform a comparison of two approaches for the
parallelization of an existing, free software, FullSWOF 2D (http://www.
univ-orleans.fr/mapmo/soft/FullSWOF/ that solves shallow water equations for
applications in hydrology) based on a domain decomposition strategy. The first
approach is based on the classical MPI library while the second approach uses
Parallel Algorithmic Skeletons and more precisely a library named SkelGIS
(Skeletons for Geographical Information Systems). The first results presented
in this article show that the two approaches are similar in terms of
performance and scalability. The two implementation strategies are however very
different and we discuss the advantages of each one.


title: Simplicial localization of homotopy algebras over a prop

abstract:
  We prove that a weak equivalence between two cofibrant (colored) props in
chain complexes induces a Dwyer-Kan equivalence between the simplicial
localizations of the associated categories of algebras. This homotopy
invariance under base change implies that the homotopy category of homotopy
algebras over a prop P does not depend on the choice of a cofibrant resolution
of P, and gives thus a coherence to the notion of algebra up to homotopy in
this setting. The result is established more generally for algebras in
combinatorial monoidal dg categories.


title: "Intelligent" controllers on cheap and small programmable devices

abstract:
  It is shown that the "intelligent" controllers which are associated to the
recently introduced model-free control synthesis may be easily implemented on
cheap and small programmable devices. Several successful numerical experiments
are presented with a special emphasis on fault tolerant control.


title:
Using a Monte-Carlo-based approach to evaluate the uncertainty on fringe
  projection technique

abstract:
  A complete uncertainty analysis on a given fringe projection set-up has been
performed using Monte-Carlo approach. In particular the calibration procedure
is taken into account. Two applications are given: at a macroscopic scale,
phase noise is predominant whilst at microscopic scale, both phase noise and
calibration errors are important. Finally, uncertainty found at macroscopic
scale is close to some experimental tests (~100 {\mu}m).


title:
Biomechanical caracterisation of lumbar belt by full-field techniques:
  Preliminary results

abstract:
  In France, 50% of the population per year is suffering from low back pain.
Lumbar belt are frequently proposed as a part of the treatment of this
pathology. However mechanical ways of working of this medical device is not
clearly understood, but abdominal pressure is often related. So an optical
method was developed in this study to measure strain in lumbar belt and trunk
interface and to derive a pressure estimation. Optical method consisted of
coupling fringe projection and digital image correlation (DIC). Measurement has
been carried out on the right side of a manikin wearing a lumbar belt. Average
strain is 0.2 and average pressure is 1 kPa. Continuation of this study will be
comparison of strain and pressure in different areas of lumbar belt (left side,
front and back) and comparison of different lumbar belts. Results will be used
in a finite elements model to determine lumbar belt impact in intern body. In
long term, this kind of study will be done on human.


title: Direct strain and slope measurement using 3D DSPSI

abstract:
  This communication presents a new implementation of DSPSI. Its main features
are 1. an advanced model taking into account the beam divergence, 2. the
coupling with a surface shape measurement in order to generalize DSPSI to
nonplanar surfaces 3. the use of small shear distance made possible using a
precise measurement procedure. A first application on a modified Iosipescu
shear test is presented and compared to classical DIC measurements.


title: Normalizers and split extensions

abstract:
  We make explicit a larger structural phenomenon hidden behind the existence
of normalizers in terms of existence of certain cartesian maps related to the
kernel functor.


title: Geometry of the eigencurve at critical Eisenstein series of weight 2

abstract:
  In this paper we show that the critical Eisenstein series of weight 2,
E_{2}^{crit_{p}}, is smooth in the eigencurve C(l), where l is a prime. We also
show that E_{2}^{crit_{p},ord_{l}} is smooth in the full eigencurve C^{full}(l)
and E_{2}^{crit_{p},ord_{l_{1}},ord_{l_{2}}} is non-smooth in the full
eigencurve C^{full}(l_{1}l_{2}). Further, we show that, E_{2}^{crit_{p}}, is
\'etale over the weight space in the eigencurve C(l). As a consequence, we show
that level lowering conjecture of Paulin fails to hold at
E_{2}^{crit_{p},ord_{l}}.


title:
Efficient Reinforcement Learning in Deterministic Systems with Value
  Function Generalization

abstract:
  We consider the problem of reinforcement learning over episodes of a
finite-horizon deterministic system and as a solution propose optimistic
constraint propagation (OCP), an algorithm designed to synthesize efficient
exploration and value function generalization. We establish that when the true
value function lies within a given hypothesis class, OCP selects optimal
actions over all but at most K episodes, where K is the eluder dimension of the
given hypothesis class. We establish further efficiency and asymptotic
performance guarantees that apply even if the true value function does not lie
in the given hypothesis class, for the special case where the hypothesis class
is the span of pre-specified indicator functions over disjoint sets. We also
discuss the computational complexity of OCP and present computational results
involving two illustrative examples.


title: General monogamy property of global quantum discord and the application

abstract:
  We provide a family of general monogamy inequalities for global quantum
discord (GQD), which can be considered as an extension of the usual discord
monogamy inequality. It can be shown that those inequalities are satisfied
under the similar condition for the holding of usual monogamy relation. We find
that there is an intrinsic connection among them. Furthermore, we present a
different type of monogamy inequality and prove that it holds under the
condition that the bipartite GQDs do not increase when tracing out some
subsystems. We also study the residual GQD based on the second type of monogamy
inequality. As applications of those quantities, we investigate the GQDs and
residual GQD in characterizing the quantum phase transition in the transverse
field Ising model.


title: Short-range mechanisms of neutrinoless double beta decay at the LHC

abstract:
  Lepton number violation (LNV) mediated by short range operators can manifest
itself in both neutrinoless double beta decay and in processes with same sign
dilepton final states at the LHC. We derive limits from existing LHC data at
$\sqrt{s}=8$ TeV and compare the discovery potential of the forthcoming
$\sqrt{s}=14$ TeV phase of the LHC with the sensitivity of current and future
neutrinoless double beta decay experiments, assuming the short-range part of
the decay amplitude dominates. We focus on the first of two possible topologies
triggered by one fermion and two bosons in the intermediate state. In all
cases, except for the pure leptoquark mechanism, the LHC will be more sensitive
than neutrinoless double beta decay in the future. In addition, we propose to
search for a charge asymmetry in the final state leptons and to use different
invariant mass peaks as a possibility to discriminate the various possible
mechanisms for LNV signals at the LHC.


title:
Quantum Isometry Groups of Noncommutative Manifolds Obtained by
  Deformation Using Dual Unitary 2-Cocycles

abstract:
  It is proved that the (volume and orientation-preserving) quantum isometry
group of a spectral triple obtained by deformation by some dual unitary
2-cocycle is isomorphic with a similar twist-deformation of the quantum
isometry group of the original (undeformed) spectral triple. This result
generalizes similar work by Bhowmick and Goswami for Rieffel-deformed spectral
triples in [Comm. Math. Phys. 285 (2009), 421-444, arXiv:0707.2648].


title: The ASTRI SST-2M Prototype: Structure and Mirror

abstract:
  The next generation of IACT (Imaging Atmospheric Cherenkov Telescope) will
explore the uppermost end of the VHE (Very High Energy) domain up to about few
hundreds of TeV with unprecedented sensibility, angular resolution and imaging
quality. To this end, INAF (Italian National Institute of Astrophysics) is
currently developing a scientific and technological telescope prototype for the
implementation of the CTA (Cherenkov Telescope Array) observatory. ASTRI
(Astrofisica con Specchi a Tecnologia Replicante Italiana) foresees the full
design, development, installation and calibration of a Small Size 4 meter class
Telescope. The telescope, named SST-2M, is based on an aplanatic, wide field,
double reflection optical layout in a Schwarzschild-Couder configuration. In
this paper we report about the technological solutions adopted for the
telescope and for the mirrors. In particular the structural and
electro-mechanical design of the telescope and the results on the optical
performance derived after the development of a prototype of the segments that
will be assembled to form the primary mirror.

categories: astro-ph.IM astro-ph.HE hep-ex physics.ins-det


title: Power Efficiency for Device-to-Device Communications

abstract:
  The concept of device-to-Device (D2D) communication as an underlay
coexistence with cellular networks gains many advantages of improving system
performance. In this paper, we model such a two-layer heterogenous network
based on stochastic geometry approach. We aim at minimizing the expected power
consumption of the D2D layer while satisfying the outage performance of both
D2D layer and cellular layer. We consider two kinds of power control schemes.
The first one is referred as to independent power control where the transmit
powers are statistically independent of the networks and all channel
conditions. The second is named as dependent power control where the transmit
power of each user is dependent on its own channel condition. A closed-form
expression of optimal independent power control is derived, and we point out
that the optimal power control for this case is fixed and not relevant to the
randomness of the network. For the dependent power control case, we propose an
efficient way to find the close-to-optimal solution for the power-efficiency
optimization problem. Numerical results show that dependent power control
scheme saves about half of power that the independent power control scheme
demands.


title:
Edge States in Molecular Solid \alpha-(BEDT-TTF)2I3: Effects of Electron
  Correlations

abstract:
  We examine the edge states of the Dirac electrons in the molecular material
\alpha-(BEDT-TTF)2I3 with electron-electron interactions. Based on the analysis
of the extended Hubbard model with the Hartree-Fock approximation, we show that
the charge-ordered phase has the gapless edge states only in the vicinity of
the phase boundary between the zero-gap state and the charge-ordered phase. We
also show a peculiar flux phase caused by the long-range Coulomb interaction
with the same mechanism as topological Mott insulator phase.


title: Inhomogeneous viscous fluids in FRW universe

abstract:
  We give a brief review of some aspects of inhomogeneous viscous fluids in a
flat Friedmann-Robertson-Walker Universe. In general, it is pointed out that
several fluid models may bring the future Universe evolution to become
singular, with the appearance of the so-called Big Rip scenario. We investigate
the effects of fluids coupled with dark matter in a de Sitter Universe, by
considering several cases. Due to this coupling, the coincidence problem may be
solved, and if the de Sitter solution is stable, the model is also protected
against the Big Rip singularity.


title: Flat/AdS boundary conditions in three dimensional conformal gravity

abstract:
  We present the asymptotic analysis of 3D conformal gravity as a SO(3,2)
Chern-Simons gauge theory with Minkowskian (flat) and AdS boundary conditions.
We further extend these boundary conditions to the case where the Weyl mode and
the partial massless mode are allowed to fluctuate. The latter leads to loosing
one copy of the Virasoro algebra and the former to a u(1) current extension of
the asymptotic symmetry algebra and shifting the Virasoro central charge by
one. We also give a pedagogical canonical and asymptotic analysis of 3D pure
gravity as an ISO(2,1) Chern-Simons gauge theory with flat boundary conditions.


title:
Scaling perspective on Intramolecular vibrational energy flow:
  analogies, insights, and challenges

abstract:
  Review of the scaling approach to intramolecular vibrational energy flow
emphasizing the classical-quantum correspondence perspective.


title:
The power spectrum of systematics in cosmic shear tomography and the
  bias on cosmological parameters

abstract:
  Cosmic shear tomography has emerged as one of the most promising tools to
both investigate the nature of dark energy and discriminate between General
Relativity and modified gravity theories. In order to successfully achieve
these goals, systematics in shear measurements have to be taken into account;
their impact on the weak lensing power spectrum has to be carefully
investigated in order to estimate the bias induced on the inferred cosmological
parameters. To this end, we develop here an efficient tool to compute the power
spectrum of systematics by propagating, in a realistic way, shear measurement,
source properties and survey setup uncertainties. Starting from analytical
results for unweighted moments and general assumptions on the relation between
measured and actual shear, we derive analytical expressions for the
multiplicative and additive bias, showing how these terms depend not only on
the shape measurement errors, but also on the properties of the source galaxies
(namely, size, magnitude and spectral energy distribution). We are then able to
compute the amplitude of the systematics power spectrum and its scaling with
redshift, while we propose a multigaussian expansion to model in a
non-parametric way its angular scale dependence. Our method allows to
self-consistently propagate the systematics uncertainties to the finally
observed shear power spectrum, thus allowing us to quantify the departures from
the actual spectrum. We show that even a modest level of systematics can induce
non-negligible deviations, thus leading to a significant bias on the recovered
cosmological parameters.


title: Quantitative Small Subgraph Conditioning

abstract:
  We revisit the method of small subgraph conditioning, used to establish that
random regular graphs are Hamiltonian a.a.s. We refine this method using new
technical machinery for random $d$-regular graphs on $n$ vertices that hold not
just asymptotically, but for any values of $d$ and $n$. This lets us estimate
how quickly the probability of containing a Hamiltonian cycle converges to 1,
and it produces quantitative contiguity results between different models of
random regular graphs. These results hold with $d$ held fixed or growing to
infinity with $n$. As additional applications, we establish the distributional
convergence of the number of Hamiltonian cycles when $d$ grows slowly to
infinity, and we prove that the number of Hamiltonian cycles can be
approximately computed from the graph's eigenvalues for almost all regular
graphs.


title:
Spin correlated dielectric memory and rejuvenation in relaxor
  ferroelectric CuCrS2

abstract:
  CuCrS2, a Heisenberg antiferromagnet with layered edge sharing triangular
lattice, exhibits a spiral magnetic order. Dielectric (E) and polarization
studies show magnetoelectric (ME) coupling at Neel temperature (T_N=38 K) where
simultaneous dielectric and magnetic long range order occur. The compound shows
a diffused ferroelectric (FE) transition and slow relaxation dynamics above
T_N, indicative of relaxor FE behavior. Interestingly, memory effect and
magnetic field induced rejuvenation are also observed in E, establishing
cooperative glassy dynamics and ME coupling even above T_N. We discuss the role
of geometrical frustration and metal ligand hybridization for these unusual
properties.


title: Directly Specifying the Power Semicircle Distribution

abstract:
  A new proof for a newly proved conjecture of Soltani and Roozegar (2012) is
provided; our proof does not make any use of the Stieltjes transform unlike the
proof of Roozegar and Soltani (2013), and the distribution of power semicircle
has been directly specified, contrary to the authors' claim in (Roozegar and
Soltani 2013).


title:
Palindromic width of wreath products, metabelian groups, and max-n
  solvable groups

abstract:
  A group has finite palindromic width if there exists $n$ such that every
element can be expressed as a product of $n$ or fewer palindromic words. We
show that if $G$ has finite palindromic width with respect to some generating
set, then so does $G \wr \mathbb{Z}^{r}$. We also give a new, self-contained,
proof that finitely generated metabelian groups have finite palindromic width.
Finally, we show that solvable groups satisfying the maximal condition on
normal subgroups (max-n) have finite palindromic width.


title:
Sub-Gap Structure in the Conductance of a Three-Terminal Josephson
  Junction

abstract:
  Three-terminal superconductor (S) - normal metal (N) - superconductor (S)
Josephson junctions are investigated. In a geometry where a T-shape normal
metal is connected to three superconducting reservoirs, new sub-gap structures
appear in the differential resistance for specific combinations of the
superconductor chemical potentials. Those correspond to a correlated motion of
Cooper pairs within the device that persist well above the Thouless energy and
is consistent with the prediction of quartets formed by two entangled Cooper
pairs. A simplified nonequilibrium Keldysh Green's function calculation is
presented that supports this interpretation.


title: Completeness of generalized transmission eigenstates

abstract:
  We prove the completeness of the generalized (interior) transmission
eigenstates for the acoustic and Schr\"odinger equations. The method uses the
ellipticity theory of Agranovich and Vishik.


title:
Theoretical models of planetary system formation: mass vs semi-major
  axis

abstract:
  Planet formation models have been developed during the last years in order to
try to reproduce the observations of both the solar system, and the extrasolar
planets. Some of these models have partially succeeded, focussing however on
massive planets, and for the sake of simplicity excluding planets belonging to
planetary systems. However, more and more planets are now found in planetary
systems. This tendency, which is a result of both radial velocity, transit and
direct imaging surveys, seems to be even more pronounced for low mass planets.
These new observations require the improvement of planet formation models,
including new physics, and considering the formation of systems. In a recent
series of papers, we have presented some improvements in the physics of our
models, focussing in particular on the internal structure of forming planets,
and on the computation of the excitation state of planetesimals, and their
resulting accretion rate. In this paper, we focus on the concurrent effect of
the formation of more than one planet in the same protoplanetary disc, and show
the effect, in terms of global architecture and composition of this
multiplicity. We use a N-body calculation including collision detection to
compute the orbital evolution of a planetary system. Moreover, we describe the
effect of competition for accretion of gas and solids, as well as the effect of
gravitational interactions between planets. We show that the masses and
semi-major axis of planets are modified by both the effect of competition and
gravitational interactions. We also present the effect of the assumed number of
forming planets in the same system (a free parameter of the model), as well as
the effect of the inclination and eccentricity damping.


title: Lax matrix solution of c=1 Conformal Field Theory

abstract:
  To a correlation function in a two-dimensional conformal field theory with
the central charge $c=1$, we associate a matrix differential equation $\Psi' =
L \Psi$, where the Lax matrix $L$ is a matrix square root of the
energy-momentum tensor. Then local conformal symmetry implies that the
differential equation is isomonodromic. This provides a justification for the
recently observed relation between four-point conformal blocks and solutions of
the Painlev\'e VI equation. This also provides a direct way to compute the
three-point function of Runkel-Watts theory -- the common $c\rightarrow 1$
limit of Minimal Models and Liouville theory.


title:
Production of the Extreme-Ultraviolet Late Phase of an X Class Flare in
  a Three-Stage Magnetic Reconnection Process

abstract:
  We report observations of an X class flare on 2011 September 6 by the
instruments onboard the Solar Dynamics Observatory (SDO). The flare occurs in a
complex active region with multiple polarities. The Extreme-Ultraviolet (EUV)
Variability Experiment (EVE) observations in the warm coronal emission reveal
three enhancements, of which the third one corresponds to an EUV late phase.
The three enhancements have a one-to-one correspondence to the three stages in
flare evolution identified by the spatially-resolved Atmospheric Imaging
Assembly (AIA) observations, which are characterized by a flux rope eruption, a
moderate filament ejection, and the appearance of EUV late phase loops,
respectively. The EUV late phase loops are spatially and morphologically
distinct from the main flare loops. Multi-channel analysis suggests the
presence of a continuous but fragmented energy injection during the EUV late
phase resulting in the warm corona nature of the late phase loops. Based on
these observational facts, We propose a three-stage magnetic reconnection
scenario to explain the flare evolution. Reconnections in different stages
involve different magnetic fields but show a casual relationship between them.
The EUV late phase loops are mainly produced by the least energetic magnetic
reconnection in the last stage.


title: Local time in diffusive media and applications to imaging

abstract:
  Local time is the measure of how much time a random walk has visited a given
position. In multiple scattering media, where waves are diffuse, local time
measures the sensitivity of the waves to the local medium's properties. Local
variations of absorption, velocity and scattering between two measurements
yield variations in the wave field. These variations are proportionnal to the
local time of the volume where the change happened and the amplitude of
variation. The wave field variations are measured using correlations and can be
used as input in a inversion algorithm to produce variation maps. The present
article gives the expression of the local time in dimensions one, two and three
and an expression of its fluctuations, in order to perform such inversions and
estimate their accuracy.


title:
Charting the TeV Milky Way: H.E.S.S. Galactic plane survey maps, catalog
  and source populations

abstract:
  Very-high-energy (VHE, E>100 GeV) gamma-rays provide a unique view of the
non-thermal universe, tracing the most violent and energetic phenomena at work
inside our Galaxy and beyond. The latest results of the H.E.S.S. Galactic Plane
Survey (HGPS) undertaken by the High Energy Stereoscopic System (H.E.S.S.), an
array of four imaging atmospheric Cherenkov telescopes located in Namibia, are
described here. The HGPS aims at the detection of cosmic accelerators with
environments suitable for the production of photons at the highest energies and
has led to the discovery of an unexpectedly large and diverse population of
over 60 sources of TeV gamma rays within its current range of l = 250 to 65
degrees in longitude and |b|<3.5 degrees in latitude. The data set of the HGPS
comprises 2800 hours of high-quality data, taken in the years 2004 to 2013. The
sensitivity for the detection of point-like sources, assuming a power-law
spectrum with a spectral index of 2.3 at a statistical significance of 5 sigma,
is now at the level of 2% Crab or better in the core HGPS region. The latest
maps of the inner Galaxy at TeV energies are shown alongside an introduction to
the first H.E.S.S. Galactic Plane Survey catalog. Finally, in addition to an
overview of the H.E.S.S. Galactic source population a few remarkable, recently
discovered sources will be highlighted.


title:
Comment on "Pt magnetic polarization on Y3Fe5O12 and magnetotransport
  characteristics"

abstract:
  In a recent Letter [Y.M. Lu et al., Phys. Rev. Lett. 110, 147207 (2013)], Lu
et al. reported on "ferromagneticlike transport properties" of thin films of
Pt, deposited ex situ via sputtering on the ferrimagnetic insulator Y3Fe5O12.
The authors found a magnetoresistance in Pt displaying a hysteresis
corresponding to the coercive field of Y3Fe5O12, consistent with the findings
of other groups. While the latter interpreted their data in terms of the
recently proposed spin-Hall magnetoresistance, Lu et al. attributed their
observation to a magnetic proximity effect. To support this interpretation,
they measured the X-ray magnetic circular dichroism (XMCD) at the Pt L2,3 edges
from a Pt/Y3Fe5O12 sample with a Pt thickness of 1.5 nm and derived an average
induced magnetic moment of 0.054 Bohr magnetons per Pt atom. This is
contradictory to the results of our previous comprehensive XMCD study of three
different Pt/Y3Fe5O12 samples with Pt thicknesses of 3, 7, and 10 nm from which
we identified an upper limit of (0.003 +/- 0.001) Bohr magnetons per Pt
[Gepr\"ags et al., Appl. Phys. Lett. 101, 262407 (2012), arXiv:1211.0916].


title: On the Gel'fand-Calder\'on inverse problem in two dimensions

abstract:
  We prove uniqueness and stability for the inverse boundary value problem of
the two dimensional Schr\"odinger equation. We do not assume the potentials to
be continuous or even bounded. Instead, we assume that some of their positive
fractional derivatives are in a specific Lorentz space. These spaces are a
natural generalization to the usual fractional Sobolev spaces. The thesis
consists of two parts.
  In the first part, we define the generalized fractional Sobolev spaces and
prove some of their properties including embeddings and interpolation
identities. In particular we sharpen the usual Sobolev embedding into the space
of H\"older-continuous functions, by showing that a particular kind of space
embeds into the space of continuous functions without any modulus of
continuity.
  The inverse problem is considered in the second part of the thesis. We prove
a new Carleman estimate for $\partial$. This estimate has a fast decay rate,
which will allow us to consider potentials with very low regularity. After that
we use Bukhgeim's oscillating exponential solutions, Alessandrini's identity
and stationary phase to get information about the difference of the potentials
from the difference of the Cauchy data. The stability estimate will be of
logarithmic type, but works with potentials of low regularity.


title:
Magnetic properties of La(0.67)Sr(0.33)MnO3/BiFeO3(001) heterojunctions:
  chemically abrupt versus atomic intermixed interface

abstract:
  Using first-principles density-functional calculations, we address the
magnetic properties of the ferromagnet/antiferromagnet
La(0.67)Sr(0.33)MnO3/BiFeO3(001) heterojunctions, and investigate possible
driving mechanisms for a ferromagnetic (FM) interfacial ordering of the Fe
spins recently observed experimentally. We find that the chemically abrupt
defect-free La(0.67)Sr(0.33)MnO3/BiFeO3(001) heterojunction displays, as ground
state, an ordering with compensated Fe spins. Cation Fe/Mn intermixing at the
interface tends to favour, instead, a FM interfacial order of the Fe spins,
coupled antiferromagnetically to the bulk La(0.67)Sr(0.33)MnO3 spins, as
observed experimentally. Such trends are understood based on a model
description of the energetics of the exchange interactions.


title: Spin/parity of Higgs-like particle at D0

abstract:
  We present prospects for tests of different spin and parity hypotheses for a
particle $H$ of mass 125 GeV produced in association with a vector boson and
decaying into a pair of b-quarks. We use the combined analysis of the WH->lvbb,
ZH->llbb, and ZH-> vvbb channels based on the full Run II dataset collected at
$\sqrt s=1.96$ TeV with the \dzero\ detector at the Fermilab Tevatron collider.


title: Tevatron Higgs results

abstract:
  We present the combination of searches for the Standard Model Higgs boson,
using up to 10 \invfb\ of $p\bar p$ collisions at $\sqrts$=1.96 TeV collected
with the CDF and \dzero\ detectors at the Fermilab Tevatron collider. The major
contributing channels are optimized for the main production modes, the
associated production with a vector boson ($VH$, with $V=W,Z$), the vector
boson fusion, and the gluon-gluon fusion, and the different decay modes $H\to
b\bar b$, $H\to\tau^+\tau^-$, $H\to W^+W^-$, and $H\to \gamma\gamma$. A
significant excess of events is observed in the mass range $115<M_H<140 \gev$.
The local significance corresponds to 3.0 standard deviations at $m_H=125
\gev$, consistent with the mass of the new particle observed at the LHC. The
observed signal strengths in all channels are consistent with the presence of a
standard model Higgs boson of mass 125 \gev. We also present prospects for
spin/parity tests to be performed in the $VH \to V b\bar b$ channels.


title: Are the Kepler Near-Resonance Planet Pairs due to Tidal Dissipation?

abstract:
  The multiple-planet systems discovered by the Kepler mission show an excess
of planet pairs with period ratios just wide of exact commensurability for
first-order resonances like 2:1 and 3:2. In principle, these planet pairs could
have both resonance angles associated with the resonance librating if the
orbital eccentricities are sufficiently small, because the width of first-order
resonances diverges in the limit of vanishingly small eccentricity. We consider
a widely-held scenario in which pairs of planets were captured into first-order
resonances by migration due to planet-disk interactions, and subsequently
became detached from the resonances, due to tidal dissipation in the planets.
In the context of this scenario, we find a constraint on the ratio of the
planet's tidal dissipation function and Love number that implies that some of
the Kepler planets are likely solid. However, tides are not strong enough to
move many of the planet pairs to the observed separations, suggesting that
additional dissipative processes are at play.


title: When is the underlying space of an orbifold a manifold?

abstract:
  We classify orthogonal actions of finite groups on Euclidean vector spaces
for which the corresponding quotient space is a topological, homological or
Lipschitz manifold, possibly with boundary. In particular, our results answer
the question of when the underlying space of an orbifold is a manifold.


title: Weighing Neutrinos in $f(R)$ gravity

abstract:
  We constrain the neutrino properties in $f(R)$ gravity using the latest
observations from cosmic microwave background(CMB) and baryon acoustic
oscillation(BAO) measurements. We first constrain separately the total mass of
neutrinos $\sum m_\nu$ and the effective number of neutrino species $N_{\rm
eff}$. Then we constrain $N_{\rm eff}$ and $\sum m_\nu$ simultaneously. We find
$\sum m_\nu<0.462 {\rm eV}$ at a $95\%$ confidence level for the combination of
Planck CMB data, WMAP CMB polarization data, BAO data and high-$l$ data from
the Atacama Cosmology Telescope and the South Pole Telescope. We also find
$N_{\rm eff}=3.32^{+0.54}_{-0.51}$ at a $95\%$ confidence level for the same
data set. When constraining $N_{\rm eff}$ and $\sum m_\nu$ simultaneously, we
find $N_{\rm eff}=3.58^{+0.72}_{-0.69}$ and $\sum m_\nu<0.860{\rm eV}$ at a
$95\%$ confidence level, respectively.


title:
Hydrostatic pressures dependence of superconductivity in PrO0.5F0.5BiS2
  superconductor

abstract:
  In this communication, we report the temperature dependence (3 to 300K) of
the electrical resistivity of BiS2 based layered PrO0.5F0.5BiS2 superconductor
at ambient and hydrostatic pressure of up to 3GPa. It is observed that Tc
increases with pressure at the rate of dTc/dP=0.45/GPa for PrO0.5F0.5BiS2
compound. It is envisaged that one may increase the Superconducting transition
temperature (Tc) of recently discovered PrO0.5F0.5BiS2 superconductor by
applying hydrostatic external or internal chemical pressure via suitable on
site substitutions.


title:
Double percolation effects and fractal behavior in
  magnetic/superconducting hybrids

abstract:
  Perpendicular magnetic anisotropy ferromagnetic/ superconducting (FM/SC)
bilayers with a labyrinth domain structure are used to study nucleation of
superconductivity on a fractal network, tunable through magnetic history. As
clusters of reversed domains appear in the FM layer, the SC film shows a
percolative behavior that depends on two independent processes: the arrangement
of initial reversed domains and the fractal geometry of expanding clusters. For
a full labyrinth structure, the behavior of the upper critical field is typical
of confined superconductivity on a fractal network.


title: Says who? Automatic Text-Based Content Analysis of Television News

abstract:
  We perform an automatic analysis of television news programs, based on the
closed captions that accompany them. Specifically, we collect all the news
broadcasted in over 140 television channels in the US during a period of six
months. We start by segmenting, processing, and annotating the closed captions
automatically. Next, we focus on the analysis of their linguistic style and on
mentions of people using NLP methods. We present a series of key insights about
news providers, people in the news, and we discuss the biases that can be
uncovered by automatic means. These insights are contrasted by looking at the
data from multiple points of view, including qualitative assessment.


title:
Collins and Sivers effects in p(transv. polarized) p --> jet pion X:
  Universality and process dependence

abstract:
  In this paper we briefly review the transverse momentum dependent generalized
parton model and its application to the study of azimuthal asymmetries in the
distribution of leading hadrons (mainly pions) inside large transverse momentum
jets inclusively produced in polarized proton-proton collisions. We put
particular emphasis on the phenomenological interest of these observables, in
combination with similar asymmetries measured in semi-inclusive deeply
inelastic scattering, Drell-Yan processes and e+e- collisions, for the study of
the universality properties of the transverse momentum dependent parton
distribution and fragmentation functions. We present results for RHIC
kinematics at center-of-mass energies sqrt{s} = 200 and 500 GeV, for central
and mainly forward jet rapidities, in particular for the Sivers distribution
and the Collins fragmentation function, that are believed to be responsible of
many of the largest asymmetries measured in the last years. We also briefly
discuss the case of inclusive jet production and recent phenomenological
applications of other theoretical approaches, like the colour gauge invariant
generalized parton model and the collinear twist-three approach, aiming at
clarifying the issues of the universality and process dependence of transverse
momentum dependent functions.


title:
Interaction effect detected by compared of the irreversible and remanent
  initial magnetization curves in Ni-Cu-Zn ferrites

abstract:
  A new technique for estimation of magnetic interaction effects of initial
magnetization curves has been proposed. It deals with remanence, and initial
irreversible magnetization, curves. The method is applied for single-phase
polycrystalline Ni0.85-xCu0.15ZnxFe2O4, (x = 0, 0.2, 0.4 and 0.6), which were
synthesized by a standard ceramic technology. A study of the initial reversible
and irreversible magnetization processes in ferrite materials was carried out.
The field dependence of the irreversible, and reversible, magnetizations was
determined by magnetic losses of minor hysteresis loops obtained from different
points of an initial magnetization curve. The influence of Zn-substitutions in
Ni-Cu ferrites over irreversible magnetization processes and interactions in
magnetic systems has been analyzed.


title: Sparticle Spectroscopy from SO(10) GUT with a Unified Higgs Sector

abstract:
  We study the low energy implications, especially the particle spectroscopy,
of SO(10) grand unification in which the SO(10) symmetry is broken to the
Standard Model gauge group with a single pair of (144+\bar144) dimensional
Higgs multiplet (unified Higgs sector). In this class of models, the asymptotic
relation Y_b \approx Y_\tau \approx Y_t/6 among the third generation quark and
lepton Yukawa couplings can be derived. This relation leads to the prediction
\tan\beta \approx 14, where \tan\beta is the well known MSSM parameter. We find
that this type of Yukawa coupling unification (YU) is realized only by
employing non-universal soft supersymmetry breaking terms, dictated by SO(10)
symmetry, for the gauginos. A 125 GeV Higgs boson mass is also found to be
consistent with YU at the \sim 5% level. Without imposing a constraint on the
relic abundance of dark matter in these models, the squark and slepton masses,
with the exception of the stop, exceed 2 TeV and the gluino is heavier than 1
TeV. We show that the neutralino in this model is an acceptable dark matter
candidate through the neutralino-stop coannihilation scenario, with the stop
quark being relatively light (\gtrsim 500 GeV).


title:
First hints of pressure waves in a helical extragalactic jet:
  S5~0836+710

abstract:
  One of the open questions in extragalactic jet Astrophysics is related to the
nature of the observed radio jet, namely whether it traces a pattern or the
flow structure itself. In this paper I summarize the evidence collected for the
presence of waves in extragalactic jets. The evidence points towards the peak
of emission in helical jets corresponding to pressure-maxima of a wave that is
generated within the core region and propagates downstream. Making use of a
number of very long baseline interferometry (VLBI) observations of the radio
jet in the quasar S5~0836+710 at different frequencies and epochs, Perucho et
al. (2012) were able to observe wave-like behavior within the observed
radio-jet. The ridge-line of the emission in the jet coincides within the
errors at all frequencies. Moreover, small differences between epochs at 15 GHz
reveal wave-like motion of the ridge-line transversal to the jet propagation
axis. The authors conclude that the helicity is a real, physical structure. I
report here on those results and discuss this result in the light of new
results recently announced by other authors that confirm the presence of waves
in the close-by object BL Lac (Cohen et al., in preparation), and the possible
magnetic or hydrodynamic nature.


title: Smoothed analysis on connected graphs

abstract:
  The main paradigm of smoothed analysis on graphs suggests that for any large
graph $G$ in a certain class of graphs, perturbing slightly the edges of $G$ at
random (usually adding few random edges to $G$) typically results in a graph
having much "nicer" properties. In this work we study smoothed analysis on
trees or, equivalently, on connected graphs. Given an $n$-vertex connected
graph $G$, form a random supergraph $G^*$ of $G$ by turning every pair of
vertices of $G$ into an edge with probability $\frac{\epsilon}{n}$, where
$\epsilon$ is a small positive constant. This perturbation model has been
studied previously in several contexts, including smoothed analysis, small
world networks, and combinatorics.
  Connected graphs can be bad expanders, can have very large diameter, and
possibly contain no long paths. In contrast, we show that if $G$ is an
$n$-vertex connected graph then typically $G^*$ has edge expansion
$\Omega(\frac{1}{\log n})$, diameter $O(\log n)$, vertex expansion
$\Omega(\frac{1}{\log n})$, and contains a path of length $\Omega(n)$, where
for the last two properties we additionally assume that $G$ has bounded maximum
degree. Moreover, we show that if $G$ has bounded degeneracy, then typically
the mixing time of the lazy random walk on $G^*$ is $O(\log^2 n)$. All these
results are asymptotically tight.


title:
Potassium detection and Lithium depletion in comets C/2011 L4
  (Panstarrs) and C/1965 S1 (Ikeya-Seki)

abstract:
  On 21 March 2013 high-resolution slit spectrographs of comet C/2011 L4
(Panstarrs), at the heliocentric distance r = 0.46 Astronomical Units (AU),
were obtained at the Osservatorio Astronomico Campo dei Fiori, Italy. Emission
lines of sodium were the strongest in the spectrum as is common in comets, but
also potassium lines were detected. These have been rarely observed in comets
since the apparition of brightest comet C/1965 S1 (Ikeya-Seki). Lithium was not
detected, and stringent upper limits of its abundance compared to other alkali
were derived. We obtain abundance ratios Na/K = 54 +/-14 and Na/Li > 8000. As
well as in Mercury exosphere (Leblanc & Douressoundiram 2011)}, we show that
photoionization at the beginning of the alkali tails may increase the solar
ratio Na/K = 15.5 (Asplund et al 2009) by a factor 3, close to that required to
match the observed value. In the same tail position the Na/Li ratio increases
by a factor 2 only, very far from the factor > 8 required to match an original
meteoritic ratio. We apply the same model to similar alkali data (Preston 1967)
of comet C/1965 S1 (Ikeya-Seki), obtaining consistent results. An original
solar Na/K ratio fits the observed value at the beginning of the alkali tails
within the slit size, whereas Li is depleted by a factor > 8.


title:
Kolmogorov-Chentsov theorem and differentiability of random fields on
  manifolds

abstract:
  A version of the Kolmogorov-Chentsov theorem on sample differentiability and
H\"older continuity of random fields on domains of cone type is proved, and the
result is generalized to manifolds.


title: Near-Infrared Imaging of White Dwarfs with Candidate Debris Disks

abstract:
  We have carried out $JHK_s$ imaging of 12 white dwarf debris disk candidates
from the WIRED SDSS DR7 catalog, aiming to confirm or rule out disks among
these sources. On the basis of positional identification and the flux density
spectra, we find that seven white dwarfs have excess infrared emission, but
mostly at WISE W1 and W2 bands, four are due to nearby red objects consistent
with background galaxies or very low mass dwarfs, and one exhibits excess
emission at $JHK_s$ consistent with an unresolved L0 companion at the correct
distance. While our photometry is not inconsistent with all seven excesses
arising from disks, the stellar properties are distinct from the known
population of debris disk white dwarfs, making the possibility questionable. In
order to further investigate the nature of these infrared sources, warm Spitzer
imaging is needed, which may help resolve galaxies from the white dwarfs and
provide more accurate flux measurements.


title:
Multi-scale turbulence modeling and maximum information principle. Part
  2

abstract:
  We consider two-dimensional homogeneous shear turbulence within the context
of optimal control, a multi-scale turbulence model containing the fluctuation
velocity and pressure correlations up to the fourth order; The model is
formulated on the basis of the Navier-Stokes equations, Reynolds average, the
constraints of inequality from both physical and mathematical considerations,
the turbulent energy density as the objective to be maximized, and the fourth
order correlations as the control variables. Without imposing the maximization
and the constraints, the resultant equations of motion in the Fourier wave
number space are formally solved to obtain the transient state solutions, the
asymptotic state solutions and the evolution of a transient toward an
asymptotic under certain conditions. The asymptotic state solutions are
characterized by the dimensionless exponential time rate of growth $2\sigma$
which has an upper bound of $2\sigma_{\max}$ = 0; The asymptotic solutions can
be obtained from a linear objective convex programming. For the asymptotic
state solutions of the reduced model containing the correlations up to the
third order, the optimal control problem reduces to linear programming with the
primary component of the third order correlations or a related integral
quantity as the control variable; the supports of the second and third order
correlations are estimated for the sake of numerical simulation; the existence
of feasible solutions is demonstrated when the related quantity is the control
variable. The relevance of the formulation to flow stability analysis is
suggested.


title:
Search for the lepton-flavour violating decays $B^0_s \rightarrow
  e^{\pm}\mu^{\mp}$ and $B^0 \rightarrow e^{\pm} \mu^{\mp}$

abstract:
  A search for the lepton-flavour violating decays $B^0_s \to e^{\pm}
\mu^{\mp}$ and $B^0 \to e^{\pm} \mu^{\mp}$ is performed with a data sample,
corresponding to an integrated luminosity of 1.0 fb$^{-1}$ of $pp$ collisions
at $\sqrt{s} = 7$ TeV, collected by the LHCb experiment. The observed number of
$B^0_s \to e^{\pm} \mu^{\mp}$ and $B^0 \to e^{\pm} \mu^{\mp}$ candidates is
consistent with background expectations. Upper limits on the branching
fractions of both decays are determined to be $BR(B^0_s \to e^{\pm} \mu^{\mp})
< 1.1 \,(1.4) \times 10^{-8}$ and $BR (B^0 \to e^{\pm} \mu^{\mp}) < 2.8 \,(3.7)
\times 10^{-9}$ at 90% (95%) confidence level (C.L.). These limits are a factor
of twenty lower than those set by previous experiments. Lower bounds on the
Pati-Salam leptoquark masses are also calculated, $M_{\rm LQ} (B^0_s \to
e^{\pm} \mu^{\mp}) > 107$ TeV/c$^2$ and $M_{\rm LQ} (B^0 \to e^{\pm} \mu^{\mp})
> 126$ TeV/c$^2$ at 95% C.L., and are a factor of two higher than the previous
bounds.


title: Travelling Front of a Decaying Brane in String Field Theory

abstract:
  We consider the inhomogeneous decay of an unstable D-brane of bosonic string
theory in a linear dilaton background in a light-cone frame. At the lowest
level, the dynamical equation that describes this process is a generalisation
(that includes nonlocality and time delay) of a reaction-diffusion equation
studied by Fisher (and others). We argue that the equation of motion of the
cubic open string field theory is satisfied at least to the second order when
we start with this `Fisher deformation', a marginal operator which has a simple
pole term in its OPE. We also compute the one-point functions of closed string
operators on the disc in the presence of this deformation.


title: Robust Subspace Clustering via Thresholding

abstract:
  The problem of clustering noisy and incompletely observed high-dimensional
data points into a union of low-dimensional subspaces and a set of outliers is
considered. The number of subspaces, their dimensions, and their orientations
are assumed unknown. We propose a simple low-complexity subspace clustering
algorithm, which applies spectral clustering to an adjacency matrix obtained by
thresholding the correlations between data points. In other words, the
adjacency matrix is constructed from the nearest neighbors of each data point
in spherical distance. A statistical performance analysis shows that the
algorithm exhibits robustness to additive noise and succeeds even when the
subspaces intersect. Specifically, our results reveal an explicit tradeoff
between the affinity of the subspaces and the tolerable noise level. We
furthermore prove that the algorithm succeeds even when the data points are
incompletely observed with the number of missing entries allowed to be (up to a
log-factor) linear in the ambient dimension. We also propose a simple scheme
that provably detects outliers, and we present numerical results on real and
synthetic data.


title: An energy gap in the spectrum of atomic excitations systems

abstract:
  It is shown that atoms in the system can be treated as quantum particles
localized in potential wells, created by atomic potentials of neighboring
atoms. As a result, the state of atoms in the liquid is characterized by wave
functions and the discrete energy spectrum resulting in formation of s and p -
zones corresponding to the ground and excited states of helium atoms,
respectively, separated by a gap. The width of the gap in system equals ~8.5 K
at T=0. Formation of the gap in the energy spectrum of atomic excitations in
helium systems allows us to draw the analogy between the physical mechanisms of
superfluidity and classical superconductivity.


title:
Pulsating stars in NGC 6231 Frequency analysis and photometric mode
  identification near the main sequence

abstract:
  We used Johnson UBV photometric CCD observations to identify pulsating and
other variable stars in the young open cluster NGC 6231. The multi-color
information was used to classify pulsating variables, perform frequency
analysis, and - where possible - to compare observed to theoretical amplitude
ratios for mode identification. The data reduction was performed with standard
IRAF tools. Differential light curves have been obtained by identifying a set
of suitable comparison stars and the frequency analysis was then conducted on
the basis of Fourier methods. Our classification of pulsating stars was based
on the time scales and amplitudes of the variability with respect to the
different filters and stellar parameters as calculated from published
Str\"omgren and Geneva photometry. We identified 32 variable stars in the field
of the cluster out of which 21 are confirmed members and twelve are newly
detected variable stars. Ten stars were classified as Slowly Pulsating B (SPB)
stars in NGC 6231 out of which seven are new discoveries. We also analyzed six
previously reported {\beta} Cephei variables in more detail. One of them may be
a hybrid {\beta} Cephei/SPB pulsator. In addition, we investigated five more
previously suspected pulsators of this group which we cannot convincingly
confirm. The remaining eleven variable stars are either not members of NGC 6231
or the membership status is questionable. Among them are three previously known
{\delta} Scuti stars, two newly detected pulsators of this class, one new and
two already known eclipsing binaries, one new SPB variable, one possible
Pre-Main-Sequence (PMS) pulsator and another new variable star for which we
cannot present a classification. With more than 20 main sequence pulsators of
spectral type B, NGC 6231 becomes the open cluster with the largest population
of such pulsating stars known.


title:
Source localization in reverberant rooms using sparse modeling and
  narrowband measurements

abstract:
  We study two cases of acoustic source localization in a reverberant room,
from a number of point-wise narrowband measurements. In the first case, the
room is perfectly known. We show that using a sparse recovery algorithm with a
dictionary of sources computed a priori requires measurements at multiple
frequencies. Furthermore, we study the choice of frequencies for these
measurements, and show that one should avoid the modal frequencies of the room.
In the second case, when the shape and the boundary conditions of the room are
unknown, we propose a model of the acoustical field based on the Vekua theory,
still allowing the localization of sources, at the cost of an increased number
of measurements. Numerical results are given, using simple adaptations of
standard sparse recovery methods.


title:
Correlation between defect and magnetism of Ar9+ implanted and
  un-implanted Zn0.95Mn0.05O thin films suitable for electronic application

abstract:
  Sol-gel derived thin films of Zn0.95Mn0.05O have been implanted with Ar9+
ions with doses viz. 5x10e14 ions/cm2 (low), 1x10e15 ions/cm2 (intermediate)
and 1x10e16 ions/cm2 (high). Structural, morphological, optical and magnetic
properties of the films have been investigated. Structural study confirmed
single phase, wurtzite structure of the films. The absence of impurity phase
has been confirmed from several measurements. Ion implantation induces a large
concentration of point defects into the films as identified from optical study.
All films exhibit well above room temperature (RT) intrinsic ferromagnetism
(FM) as evidenced from field and temperature dependent magnetization
measurements. The magnetization attains the maximum value for high dose of Ar9+
ion implanted film. It shows RT saturation magnetization (MS) value of
0.69emu/gm. The observed FM has been correlated with proportion of intrinsic
defects, such as, zinc and oxygen vacancies and the values of MS. Defect
induced formation of bound magnetic polaron actually controls the FM. The
utility of these films in transparent spin electronic device has also been
exhibited.