title: Treating clitics with minimalist grammars

abstract:
  We propose an extension of Stabler's version of clitics treatment for a wider
coverage of the French language. For this, we present the lexical entries
needed in the lexicon. Then, we show the recognition of complex syntactic
phenomena as (left and right) dislo- cation, clitic climbing over modal and
extraction from determiner phrase. The aim of this presentation is the
syntax-semantic interface for clitics analyses in which we will stress on
clitic climbing over verb and raising verb.


title: Thermodynamic Description of Beta Amyloid Formation

abstract:
  Protein function depends on both protein structure and amino acid (aa)
sequence. Here we show that modular features of both structure and function can
be quantified from the aa sequences alone for the small (40,42 aa)
plaque-forming amyloid beta fragments. Some edge and center features of the
fragments are predicted. Contrasting results from the second order
hydropathicity scale based on evolutionary optimization (self-organized
criticality) and the first order scale based on complete protein (water-air)
unfolding show that fragmentation has mixed first- and second-order character.


title: Smooth monomial Togliatti systems of cubics

abstract:
  The goal of this paper is to solve the conjecture stated in a paper of
Mezzetti, Mir\'o-Roig, Ottaviani and classify all smooth minimal monomial
Togliatti systems of cubics. More precisely, we classify all minimal monomial
artinian ideals generated by cubics, failing the weak Lefschetz property and
whose apolar cubic system defines a smooth toric variety or, equivalently, we
classify all minimal monomial artinian ideals generated by cubics whose apolar
cubic system defines a smooth toric variety satisfying at least a Laplace
equation of order 2.


title:
171Yb+ System Stability, 5D3/2 Hyperfine State Detection Efficiency and
  F=2 Lifetime

abstract:
  A data acquisition system is described that is designed to stabilize cooling
and probe rates to maximize detection sensitivity and minimize possible
systematic errors due to correlations between drifting experimental conditions
and varying drive parameters. Experimental parameters that affect the Yb171
5D3/2 hyperfine state preparation and detection efficiency are characterized
and optimized. A set of wait times for optimal sampling of the D3/2(F=2)
lifetime is chosen and used to measure that lifetime with high statistical
sensitivity. A systematic variation in this lifetime seems to be apparent. The
source of the variation was not identified, but ion number and cooling rate
appear to be ruled out. A net determination is made of
tau=61.8ms+-(0.6)_stat+-(6.4)_sys which is significantly longer than other
measurements of the same quantity. An alternate shelving scheme is proposed
that would provide S-D state discrimination for Yb even isotopes as well as
improved sensitivity for D state hyperfine discrimination in odd isotopes.


title: Three-Dimensional Magnetohydrodynamic Simulations of the Crab Nebula

abstract:
  In this paper we give a detailed account of the first 3D relativistic
magnetohydrodynamic (MHD) simulations of Pulsar Wind Nebulae (PWN), with
parameters most suitable for the Crab Nebula. In order to clarify the new
features specific to 3D models, reference 2D simulations have been carried out
as well. Compared to the previous 2D simulations, we considered pulsar winds
with much stronger magnetisation, up to \sigma=3, and accounted more accurately
for the anticipated magnetic dissipation in the striped zone of these winds.
While the 3D models preserve the separation of the post termination shock flow
into the equatorial and polar components, their relative strength and
significance differ. Whereas the highly magnetised 2D models produce highly
coherent and well collimated polar jets capable of efficient "drilling" through
the supernova shell, in the corresponding 3D models the jets are disrupted by
the kink mode current driven instability and "dissolve" into the main body of
PWN after propagation of several shock radii. Our results show that contrary to
the expectations based on 1D analytical and semi-analytical models, our
numerical solutions with highly magnetized pulsar winds still produce
termination shocks with radii comparable to those deduced from the
observations. We present polarized synchrotron maps constructed from the 3D
simulations, showing that the wealth of morphological features observed with
Hubble and Chandra can well be reproduced with 3D-MHD models.


title:
L2 Boosting on generalized Hoeffding decomposition for dependent
  variables. Application to Sensitivity Analysis

abstract:
  This paper is dedicated to the study of an estimator of the generalized
Hoeffding decomposition. We build such an estimator using an empirical
Gram-Schmidt approach and derive a consistency rate in a large dimensional
settings.
  Then, we apply a greedy algorithm with these previous estimators to
Sensitivity Analysis. We also establish the consistency of this $\mathbb
L_2$-boosting up to sparsity assumptions on the signal to analyse. We end the
paper with numerical experiments, which demonstrates the low computational cost
of our method as well as its efficiency on standard benchmark of Sensitivity
Analysis.


title:
Nucleation of austenite in mechanically stabilized martensite by
  localized heating

abstract:
  The nucleation of bcc austenite in a single crystal of a mechanically
stabilized 2H-martensite of Cu-Al-Ni shape-memory alloy is studied. The
nucleation process is induced by localized heating and observed by optical
microscopy. It is observed that nucleation occurs after a time delay and that
the nucleation points are always located at one of the corners of the sample (a
rectangular bar in the austenite), regardless of where the localized heating is
applied. Using a simplified nonlinear elasticity model, we propose an
explanation for the location of the nucleation points, by showing that the
martensite is a local minimizer of the energy with respect to localized
variations in the interior, on faces and edges of the sample, but not at some
corners, where a localized microstructure can lower the energy.


title: Monte Carlo convergence of rival samplers

abstract:
  It is often necessary to make sampling-based statistical inference about many
probability distributions in parallel. Given a finite computational resource,
this article addresses how to optimally divide sampling effort between the
samplers of the different distributions. Formally approaching this decision
problem requires both the specification of an error criterion to assess how
well each group of samples represent their underlying distribution, and a loss
function to combine the errors into an overall performance score. For the first
part, a new Monte Carlo divergence error criterion based on Jensen-Shannon
divergence is proposed. Using results from information theory, approximations
are derived for estimating this criterion for each target based on a single
run, enabling adaptive sample size choices to be made during sampling.


title: Search for the decay D0 to \pi+ \pi- \mu+ \mu-

abstract:
  A search for the D0 to \pi+ \pi- \mu+ \mu- decay, where the muon pair does
not originate from a resonance, is performed using proton-proton collision data
corresponding to an integrated luminosity of 1.0 fb-1 recorded by the LHCb
experiment at a centre-of-mass energy of 7 TeV. No signal is observed and an
upper limit on the relative branching fraction with respect to the resonant
decay mode D0 to \pi+ \pi- \phi(to \mu+ \mu-), under the assumption of a
phase-space model, is found to be B(D0 to \pi+ \pi- mu+ mu-)/B(D0 to \pi+ \pi-
\phi(to \mu+ \mu-)) < 0.96 at the 90% confidence level. The upper limit on the
absolute branching fraction is evaluated to be B(D0 to \pi+ \pi- \mu+ \mu-) <
5.5 x 10-7 at 90% confidence level. This is the most stringent to date.


title:
Coarse grained Potential analysis of neutron-proton and proton-proton
  scattering below pion production threshold

abstract:
  Using the delta-shell representation we present a successful fit to
neutron-proton and proton-proton scattering data below pion production
threshold. A detailed overview of the theory necessary to calculate observables
with this potential is presented. A new data selection process is used to
obtain the largest mutually consistent data base. The analysis includes data
within the years 1950 to 2013. Using 46 parameters we obtain chi^2/Ndata = 1.04
with Ndata = 6713 including normalization data. Phase shifts with error bars
are provided.


title: The Chillingworth Class is a Signed Stable Length

abstract:
  An orientation is defined on a family of curve graphs on which the Torelli
group acts. It is shown that the resulting signed stable length of an element
of the Torelli group is a cohomology class. This cohomology class is half the
dual of the contraction of the Johnson homomorphism, the socalled
"Chillingworth class".


title: Search for the doubly charmed baryon Xi_cc^+

abstract:
  A search for the doubly charmed baryon Xi_cc^+ in the decay mode Xi_cc^+ ->
Lambda_c^+ K^- pi^+ is performed with a data sample, corresponding to an
integrated luminosity of 0.65/fb, of pp collisions recorded at a centre-of-mass
energy of 7 TeV. No significant signal is found in the mass range 3300-3800
MeV/c^2. Upper limits at the 95% confidence level on the ratio of the Xi_cc^+
production cross-section times branching fraction to that of the Lambda_c^+, R,
are given as a function of the Xi_cc^+ mass and lifetime. The largest upper
limits range from R < 1.5 x 10^-2 for a lifetime of 100 fs to R < 3.9 x 10^-4
for a lifetime of 400 fs.


title:
Intrinsic filtering on Lie groups with applications to attitude
  estimation

abstract:
  This paper proposes a probabilistic approach to the problem of intrinsic
filtering of a system on a matrix Lie group with invariance properties. The
problem of an invariant continuous-time model with discrete-time measurements
is cast into a rigorous stochastic and geometric framework. Building upon the
theory of continuous-time invariant observers, we show that, as in the linear
case, the error equation is a Markov chain that does not depend on the state
estimate. Thus, when the filter's gains are held fixed, and the filter admits
almost-global convergence properties with noise turned off, the noisy error's
distribution is proved to converge to a stationary distribution, providing
insight into the mathematical theory of filtering on Lie groups. For
engineering purposes we also introduce the discrete-time Invariant Extended
Kalman Filter, for which the trusted covariance matrix is shown to
asymptotically converge, and some numerically more involved sample-based
methods as well to compute the Kalman gains. The methods are applied to
attitude estimation, allowing to derive novel theoretical results in this
field, and illustrated through simulations on synthetic data.


title: How Long does a Burst Burst?

abstract:
  Several gamma-ray bursts (GRBs) last much longer (~hours) in gamma-rays than
typical long GRBs (~ minutes), and recently it was proposed that these
"ultra-long GRBs" may form a distinct population, probably with a different
(e.g. blue supergiant) progenitor than typical GRBs. However, Swift
observations suggest that many GRBs have extended central engine activities
manifested as flares and internal plateaus in X-rays. We perform a
comprehensive study on a large sample of Swift GRBs with XRT observations to
investigate GRB central engine activity duration and to determine whether
ultra-long GRBs are unusual events. We define burst duration t_burst based on
both gamma-ray and X-ray light curves rather than using gamma-ray observations
alone. We find that t_burst can be reliably measured in 343 GRBs. Within this
"good" sample, 21.9% GRBs have t_burst >=10^3 s and 11.5% GRBs have t_burst
>=10^4 s. There is an apparent bimodal distribution of t_burst in this sample.
However, when we consider an "undetermined" sample (304 GRBs) with t_burst
possibly falling in the gap between GRB duration T_90 and the first X-ray
observational time, as well as a selection effect against t_burst falling into
the first Swift orbital "dead zone" due to observation constraints, the
intrinsic underlying t_burst distribution is consistent with being a single
component distribution. We found that the existing evidence for a separate
ultra-long GRB population is inconclusive, and further multi-wavelength
observations are needed to draw a firmer conclusion. We also discuss the
theoretical implications of our results. In particular, the central engine
activity duration of GRBs is generally much longer than the gamma-ray T90
duration and it does not even correlate with T90. It would be premature to make
a direct connection between T90 and the size of the progenitor star.


title:
Nonequilibrium quantum fluctuation relations for harmonic systems in
  nonthermal environments

abstract:
  We formulate exact generalized nonequilibrium fluctuation relations for the
quantum mechanical harmonic oscillator coupled to multiple harmonic baths. Each
of the different baths is prepared in its own individual (in general
nonthermal) state. Starting from the exact solution for the oscillator dynamics
we study fluctuations of the oscillator position as well as of the energy
current through the oscillator under general nonequilibrium conditions. In
particular, we formulate a fluctuation-dissipation relation for the oscillator
position autocorrelation function that generalizes the standard result for the
case of a single bath at thermal equilibrium. Moreover, we show that the
generating function for the position operator fullfills a generalized
Gallavotti-Cohen-like relation. For the energy transfer through the oscillator,
we determine the average energy current together with the current fluctuations.
Finally, we discuss the generalization of the cumulant generating function for
the energy transfer to nonthermal bath preparations.


title:
A biomarker based on gene expression indicates plant water status in
  controlled and natural environments

abstract:
  Plant or soil water status are required in many scientific fields to
understand plant responses to drought. Because the transcriptomic response to
abiotic conditions, such as water deficit, reflects plant water status, genomic
tools could be used to develop a new type of molecular biomarker. Using the
sunflower (Helianthus annuus L.) as a model species to study the transcriptomic
response to water deficit both in greenhouse and field conditions, we
specifically identified three genes that showed an expression pattern highly
correlated to plant water status as estimated by the pre-dawn leaf water
potential, fraction of transpirable soil water, soil water content or fraction
of total soil water in controlled conditions. We developed a generalized linear
model to estimate these classical water status indicators from the expression
levels of the three selected genes under controlled conditions. This estimation
was independent of the four tested genotypes and the stage (pre- or
post-flowering) of the plant. We further validated this gene expression
biomarker under field conditions for four genotypes in three different trials,
over a large range of water status, and we were able to correct their
expression values for a large diurnal sampling period.


title: Quantum mechanical retrodiction through an extended mean King problem

abstract:
  The mean King problem is a conditional retrodiction problem. In this problem
Alice prepares a two prime-dimensional particles state and avails one of the
particles to the King who measures its state in one of mutually unbiased bases
of his choice. The King tells Alice his choice of basis after she completes a
control measurement on his particle. Conditioned on this knowledge, she now
infers the state observed by the King by utilizing the outcome of her control
measurement. In the extended mean King problem, studied in this paper, the King
does not tell Alice his measurement basis, but instead both the King and Alice
repeat their measurements. Proper ordering of these allows Alice to deduce both
the basis used by the King and the outcome of his first measurement, with the
King reticent throughout, i.e., this protocol effects a complete (almost)
retrodiction of the King's first measurement.


title:
Relaxation and curvature-induced molecular flows within multicomponent
  membranes

abstract:
  The quantitative understanding of membranes is still rooted in work performed
in the 1970s by Helfrich and others, concerning amphiphilic bilayers. However,
most biological membranes contain a wide variety of nonamphiphilic molecules
too. Drawing analogy with the physics of nematic/non-nematic mixtures, we
present a dynamical (out of equilibrium) description of such multicomponent
membranes. The approach combines nematohydrodynamics in the linear regime and a
proper use of (differential) geometry. The main result is to demonstrate that
one can obtain equations describing a cross-diffusion effect (similar to the
Soret and Dufour effects) between curvature and the (in-membrane) flow of
amphiphilic molecules relative to nonamphiphilic ones. Surprisingly, the shape
of a membrane relaxes according to a simple heat equation in the mean
curvature, a process that is accompanied by a simultaneous boost to the
diffusion of amphiphiles away from regions of high curvature. The model also
predicts the inverse process, by which the forced bending of a membrane induces
a flow of amphiphilic molecules towards areas of high curvature. In principle,
numerical values for the relevant diffusion coefficients should be verifiable
by experiment.


title: Product Backlog Rating: A Case Study On Measuring Test Quality In Scrum

abstract:
  Agile software development methodologies focus on software projects which are
behind schedule or highly likely to have a problematic development phase. In
the last decade, Agile methods have transformed from cult techniques to
mainstream methodologies. Scrum, an Agile software development method, has been
widely adopted due to its adaptive nature.
  This paper presents a metric that measures the quality of the testing process
in a Scrum process. As product quality and process quality correlate, improved
test quality can ensure high quality products. Also, gaining experience from
eight years of successful Scrum implementation at SoftwarePeople, we describe
the Scrum process emphasizing the testing process. We propose a metric Product
Backlog Rating (PBR) to assess the testing process in Scrum. PBR considers the
complexity of the features to be developed in an iteration of Scrum, assesses
test ratings and offers a numerical score of the testing process. This metric
is able to provide a comprehensive overview of the testing process over the
development cycle of a product.
  We present a case study which shows how the metric is used at SoftwarePeople.
The case study explains some features that have been developed in a Sprint in
terms of feature complexity and potential test assessment difficulties and
shows how PBR is calculated during the Sprint. We propose a test process
assessment metric that provides insights into the Scrum testing process.
However, the metric needs further evaluation considering associated resources
(e.g., quality assurance engineers, the length of the Scrum cycle).


title: The Moebius function and continuous extensions of rotations

abstract:
  Let $f\colon \mathbb{T}\to \mathbb{R}$ be of class $C^{1+\delta}$ for some
$\delta>0$ and let $c\in\mathbb{Z}$. We show that for a generic
$\alpha\in\mathbb{R}$, the extension $T_{c,f}\colon
\mathbb{T}^2\to\mathbb{T}^2$ of the irrational rotation $Tx=x+\alpha$, given by
$T_{c,f}(x,u)=(x+\alpha, u+cx+f(x))$ ($\bmod\ 1$) satisfies Sarnak's
conjecture.


title:
All Your Location are Belong to Us: Breaking Mobile Social Networks for
  Automated User Location Tracking

abstract:
  Many popular location-based social networks (LBSNs) support built-in
location-based social discovery with hundreds of millions of users around the
world. While user (near) realtime geographical information is essential to
enable location-based social discovery in LBSNs, the importance of user
location privacy has also been recognized by leading real-world LBSNs. To
protect user's exact geographical location from being exposed, a number of
location protection approaches have been adopted by the industry so that only
relative location information are publicly disclosed. These techniques are
assumed to be secure and are exercised on the daily base. In this paper, we
question the safety of these location-obfuscation techniques used by existing
LBSNs. We show, for the first time, through real world attacks that they can
all be easily destroyed by an attacker with the capability of no more than a
regular LBSN user. In particular, by manipulating location information fed to
LBSN client app, an ill-intended regular user can easily deduce the exact
location information by running LBSN apps as location oracle and performing a
series of attacking strategies. We develop an automated user location tracking
system and test it on the most popular LBSNs including Wechat, Skout and Momo.
We demonstrate its effectiveness and efficiency via a 3 week real-world
experiment with 30 volunteers. Our evaluation results show that we could
geo-locate a target with high accuracy and can readily recover users' Top 5
locations. We also propose to use grid reference system and location
classification to mitigate the attacks. Our work shows that the current
industrial best practices on user location privacy protection are completely
broken, and it is critical to address this immediate threat.


title:
Prediction of ultra-high ON/OFF ratio nanoelectromechanical switching
  from covalently-bound C60 chains

abstract:
  Applying a first-principles computational approach, we have systematically
analyzed the effects of [2+2] cycloaddition oligomerization of fullerene C60
chains on their junction electronic and charge transport properties. For
hypothetical infinite C60 chains, we first establish that the polymerization
can in principle increase conductance by several orders of magnitude due to the
strong orbital hybridizations and band formation. On the other hand, our
simulations of the constant-height scanning tunneling microscope (STM)
configuration shows that, in agreement with the recent experimental conclusion,
the junction electronic structure and device characteristics are virtually
unaffected by the C60 chain oligomerization. We further predict that the
switching characteristics including even the ON/OFF-state assignment will
sensitively depend on the substrate metal species due to the Fermi-level
pinning at the substrate-side contact and the subsequent energy level bending
toward the STM tip-side contact. We finally demonstrate that a force-feedbacked
nanoelectromechanical approach in which both of the C60-electrode distances are
kept at short distances before and after switching operations can achieve a
metal-independent and significantly improved switching performance due to the
Fermi-level pinning in both contacts and the large intrinsic conductance
switching capacity of the C60 chain oligomerization.


title:
Exact theory of dense amorphous hard spheres in high dimension. III. The
  full RSB solution

abstract:
  In the first part of this paper, we derive the general replica equations that
describe infinite-dimensional hard spheres at any level of replica symmetry
breaking (RSB) and in particular in the fullRSB scheme. We show that these
equations are formally very similar to the ones that have been derived for spin
glass models, thus showing that the analogy between spin glasses and structural
glasses conjectured by Kirkpatrick, Thirumalai, and Wolynes is realized in a
strong sense in the mean field limit. We also suggest how the computation could
be generalized in an approximate way to finite dimensional hard spheres. In the
second part of the paper, we discuss the solution of these equations and we
derive from it a number of physical predictions. We show that, below the
Gardner transition where the 1RSB solution becomes unstable, a fullRSB phase
exists and we locate the boundary of the fullRSB phase. Most importantly, we
show that the fullRSB solution predicts correctly that jammed packings are
isostatic, and allows one to compute analytically the critical exponents
associated with the jamming transition, which are missed by the 1RSB solution.
We show that these predictions compare very well with numerical results.


title: Dynamics of the Faraday Instability in a Small Cylinder

abstract:
  Vertical oscillation of a fluid interface above a critical amplitude excites
the Faraday instability, typically manifesting itself as a standing wave
pattern. Fundamentally, the phenomenon is an example of parametric resonance.
At high frequencies, the wavelength is small and the pattern selection process
is highly nonlinear. We excite the instability with low frequencies, where the
wavelength is large, and the form is highly influenced by the container
geometry. In this regime, the cell modes are easily excited on an individual
basis and the observed waves resemble the forms predicted from linear theory.
In our video we highlight basic spatial and temporal dynamics of this regime.
This fluid dynamics video is submitted to the APS DFD Gallery of Fluid Motion
2013, part of the 66th Annual Meeting of the American Physical Societys
Division of Fluid Dynamics (24-26 November, Pittsburgh, PA, USA).


title: Charm decay as a source of multistrange hadrons

abstract:
  We describe a newly formulated approach to account for charm production and
decay in Statistical Hadronization approach. Considering Pb--Pb collisions at
$\sqrt{s_{NN}} = 2.76$ TeV at LHC we show that charm hadron decays can be a
significant contributor to the multistrange hadron abundance. We discuss the
magnitude of expected effects as a function of charm yield.


title: Invariant Vectors for Weak Endoscopic and Saito-Kurokawa Lifts to GSp(4)

abstract:
  Let A be the adele ring over a totally real number field F. For cohomological
cuspidal automorphic irreducible representations of GSp(4,A) coming from weak
endoscopic or Saito-Kurokawa Lifts we determine the local invariant spaces
under the first principal congruence subgroup at the non-archimedean places.
For F=Q this gives rise to dimension formulas regarding certain subspaces of
the inner cohomology of the genus two Shimura variety corresponding to the
principal congruence subgroup level N=2. We prove the conjectures made by
Bergstr\"om, Faber and van der Geer in a recent paper.


title: A He-rich g-mode pulsator on the BHB

abstract:
  We introduce the first g-mode pulsator found to reside on the classical blue
horizontal branch. We extend the original discovery dataset to include more
than 3 years of continuous photometry of KIC 1718290, which reveals a rich
spectrum of low-amplitude modes with periods between one and twelve hours, most
of which follow a regular spacing of 276.3 s. This mode structure strongly
resembles that of the V1093 Her pulsators, with only a slight shift towards
longer periods. Our spectroscopy, however, reveals KIC 1718290 to be quite
distinct from the sdB stars that show V1093Her pulsations, which all have
surface gravities higher than log g = 5.1 and helium abundances depleted by at
least an order of magnitude relative to the solar composition. We find that KIC
1718290 has T_eff = 22 100 K, log g = 4.72, and a supersolar helium abundance
(log He/H = -0.45). This places it well above the extreme horizontal branch,
and rather on the very blue end of the classical horizontal branch. We conclude
that KIC 1718290 must have suffered extreme mass loss during its first giant
stage, but not sufficient to reach the extreme horizontal branch.


title:
Transmission of O-band wavelength-division-multiplexed heralded photons
  over a noise-corrupted optical fiber channel

abstract:
  We transmitted O-band heralded photons over 10 km of optical fiber in a
proof-of-concept experiment demonstrating the feasibility of using heralded
photons to improve the noise tolerance of quantum key distribution. In our
experiment, the optical fiber channel was corrupted by noise photons to the
extent that if we had used an attenuated laser as the photon source, a photon
signal-to-noise ratio of < 4.0 at the receiver, corresponding to a quantum
bit-error rate of > 10.0%, would have prevented the effective generation of
secure keys. Using a photon heralding scheme, the photon signal-to-noise ratio
in our experiment was shown to be > 7.8. This corresponds to a quantum
bit-error rate of < 5.7%, which is good enough for distilling secure keys. In
addition, we showed that it is possible to incorporate
wavelength-division-multiplexing into the photon heralding scheme to improve
overall key rate. We discussed and clarified the prospects and limitations of
the photon heralding scheme for noise-tolerant quantum key distribution.


title: Separated Belyi Maps

abstract:
  We construct Belyi maps having specified behavior at finitely many points.
Specifically, for any curve C defined over Q-bar, and any disjoint finite
subsets S, T in C(Q-bar), we construct a finite morphism f: C -> P^1 such that
f ramifies at each point in S, the branch locus of f is {0,1, infty}, and f(T)
is disjoint from {0,1, infty}. This refines a result of Mochizuki's. We also
prove an analogous result over fields of positive characteristic, and in
addition we analyze how many different Belyi maps f are required to imply the
above conclusion for a single C and S and all sets T in C(Q-bar) \ S of
prescribed cardinality.


title: Indirect search for New Physics: complementarity to direct searches

abstract:
  We present an overview on the interplay between direct searches for new
physics at the LHC and indirect constraints from the flavour sector, with an
emphasis on the implications of the recent LHCb results. The complementarity
with the Higgs search results will also be addressed. We show the correlation
and complementarity between the different sectors in the context of a few
specific examples in supersymmetry.


title:
SRCEK: A Continuous Embedding of the Channel Selection Problem for
  weighted PLS Modeling

abstract:
  SRCEK, is a technique for selecting useful channels for affine modeling of a
response by PLS. The technique embeds the discrete channel selection problem
into the continuous space of predictor preweighting, then employs a
Quasi-Newton (or other) optimization algorithm to optimize the preweighting
vector. Once the weighting vector has been optimized, the magnitudes of the
weights indicate the relative importance of each channel. The relative
importances are used to construct n different models, the kth consisting of the
k most important channels. The different models are then compared by means of
cross validation or an information criterion (e.g. BIC), allowing automatic
selection of a `good' subset of the channels. The analytical Jacobian of the
PLS regression vector with respect to the predictor weighting is derived to
facilitate optimization of the latter. This formulation exploits the reduced
rank of the predictor matrix to gain some speedup when the number of
observations is fewer than the number of predictors (the usual case for e.g. IR
spectroscopy). The method compares favourably with predictor selection
techniques surveyed by Forina et. al.


title:
Identification of the diffusion parameter in nonlocal steady diffusion
  problems

abstract:
  The problem of identifying the diffusion parameter appearing in a nonlocal
steady diffusion equation is considered. The identification problem is
formulated as an optimal control problem having a matching functional as the
objective of the control and the parameter function as the control variable.
The analysis makes use of a nonlocal vector calculus that allows one to define
a variational formulation of the nonlocal problem. In a manner analogous to the
local partial differential equations counterpart, we demonstrate, for certain
kernel functions, the existence of at least one optimal solution in the space
of admissible parameters. We introduce a Galerkin finite element discretization
of the optimal control problem and derive a priori error estimates for the
approximate state and control variables. Using one-dimensional numerical
experiments, we illustrate the theoretical results and show that by using
nonlocal models it is possible to estimate non-smooth and discontinuous
diffusion parameters.


title:
Efficient recursive algorithms for functionals based on higher order
  derivatives of the multivariate Gaussian density

abstract:
  Many developments in Mathematics involve the computation of higher order
derivatives of Gaussian density functions. The analysis of univariate Gaussian
random variables is a well-established field whereas the analysis of their
multivariate counterparts consists of a body of results which are more
dispersed. These latter results generally fall into two main categories:
theoretical expressions which reveal the deep structure of the problem, or
computational algorithms which can mask the connections with closely related
problems. In this paper, we unify existing results and develop new results in a
framework which is both conceptually cogent and computationally efficient. We
focus on the underlying connections between higher order derivatives of
Gaussian density functions, the expected value of products of quadratic forms
in Gaussian random variables, and V-statistics of degree two based on Gaussian
density functions. These three sets of results are combined into an analysis of
non-parametric data smoothers.


title:
Study of the 1D anisotropic Kondo necklace model at criticality via an
  entanglement entropy estimator

abstract:
  We use an estimator of quantum criticality based on the entanglement entropy
to discuss the ground state properties of the 1D anisotropic Kondo necklace
model. We found that the T=0 phase diagram of the model is described by a
critical line separating an antiferromagnetic phase from a Kondo singlet state.
Moreover we calculate the conformal anomaly on the critical line and obtained
that c tends to 0.5 as the thermodynamic limit is reached. We conclude that
these transitions belong to Ising universality class being, therefore, second
order transitions instead of infinite order as claimed before.


title: Characterizing Strategic Cascades on Networks

abstract:
  Transmission of disease, spread of information and rumors, adoption of new
products, and many other network phenomena can be fruitfully modeled as
cascading processes, where actions chosen by nodes influence the subsequent
behavior of neighbors in the network graph. Current literature on cascades
tends to assume nodes choose myopically based on the state of choices already
taken by other nodes. We examine the possibility of strategic choice, where
agents representing nodes anticipate the choices of others who have not yet
decided, and take into account their own influence on such choices. Our study
employs the framework of Chierichetti et al. [2012], who (under assumption of
myopic node behavior) investigate the scheduling of node decisions to promote
cascades of product adoptions preferred by the scheduler. We show that when
nodes behave strategically, outcomes can be extremely different. We exhibit
cases where in the strategic setting 100% of agents adopt, but in the myopic
setting only an arbitrarily small epsilon % do. Conversely, we present cases
where in the strategic setting 0% of agents adopt, but in the myopic setting
(100-epsilon)% do, for any constant epsilon > 0. Additionally, we prove some
properties of cascade processes with strategic agents, both in general and for
particular classes of graphs.


title: An Environmental Variation of Constants

abstract:
  Models of modified gravity, whereby local tests of gravity are evaded thanks
to a screening mechanism of the chameleon or Damour-Polyakov types, lead to a
spatial variation of the particle masses and the fine structure constant. This
is triggered by the environmental dependence of the value of the scalar field
whose presence modifies gravity. In dense media, the field settles at a density
dependent value while in sparse environments it takes the background
cosmological value. We estimate that the maximal deviation of constants from
their present values is constrained by local tests of gravity, and must be less
than $10^{-6}$.


title: Simple Irreducible Subgroups of Exceptional Algebraic Groups

abstract:
  A closed subgroup of a semisimple algebraic group is called irreducible if it
lies in no proper parabolic subgroup. In this paper we classify all irreducible
subgroups of exceptional algebraic groups $G$ which are connected, closed and
simple of rank at least $2$. Consequences are given concerning the
representations of such subgroups on various $G$-modules: for example, with one
exception, the conjugacy classes of irreducible simple connected subgroups of
rank at least $2$ are determined by their composition factors on the adjoint
module for $G$.


title: Stein's Method for Multivariate Extremes

abstract:
  We apply the Stein-Chen method to problems from extreme value theory. On the
one hand, the Stein-Chen method for Poisson approximation allows us to obtain
bounds on the Kolmogorov distance between the law of the maximum of i.i.d.
random variables, following certain well known distributions, and an extreme
value distribution. On the other hand, we introduce marked point processes of
exceedances (MPPE's) whose i.i.d. marks can be either univariate or
multivariate. We use the Stein-Chen method for Poisson process approximation to
determine bounds on the error of the approximation, in some appropriate
probability metric, of the law of the MPPE by that of a Poisson process. The
Poisson process that we approximate by has intensity measure equal to that of
the MPPE. In some cases, this intensity measure is difficult to work with, or
varies with the sample size; we then approximate by a further easier-to-use
Poisson process and estimate the error of this additional approximation.


title:
Upsilon Production in Pb-Pb and p-Pb Collisions at Forward Rapidity with
  ALICE at the LHC

abstract:
  The ALICE apparatus at the LHC was designed and built to perform dedicated
studies of the Quark-Gluon Plasma (QGP), a strongly interacting phase of QCD
matter, expected to be created in heavy-ion collisions, where quarks and gluons
are deconfined. In such collisions heavy flavours are produced at the very
early stage of the interaction by the initial hard scattering processes and
hence can be used to characterize the hot and dense medium. In particular the
sequential suppression of quarkonia (charmonia and bottomonia) was proposed as
a thermometer of the deconfined medium. The inclusive $\Upsilon(1S)$ production
has been measured down to zero transverse momentum in its dimuon decay channel
at forward rapidity $(2.5 < y_{\rm_{lab}} < 4.0)$ using the Muon Spectrometer.
Here results on the $\Upsilon(1S)$ nuclear modification factor $(R_{\rm AA})$
in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV are discussed and
compared to the measurement at mid-rapidity by the CMS Collaboration and to
theoretical predictions. Also recent results on $R_{\rm pPb}$ and
forward-to-backward yield ratio $(R_{\rm FB})$ in p-Pb collisions at
$\sqrt{s_{\rm NN}}$ = 5.02 TeV are discussed.


title: Unitary thermodynamics from thermodynamic geometry

abstract:
  Degenerate Fermi gases of atoms near a Feshbach resonance show universal
thermodynamic properties, which are here calculated with the geometry of
thermodynamics, and the thermodynamic curvature $R$. Unitary thermodynamics is
expressed as the solution to a pair of ordinary differential equations, a
"superfluid" one valid for small entropy per atom $z\equiv S/N k_B$, and a
"normal" one valid for high $z$. These two solutions are joined at a
second-order phase transition at $z=z_c$. Define the internal energy per atom
in units of the Fermi energy as $Y=Y(z)$. For small $z$, $Y(z)=y_0+y_1
z^{\alpha}+y_2 z^{2 \alpha}+\cdots,$ where $\alpha$ is a constant exponent,
$y_0$ and $y_1$ are scaling factors, and the series coefficients $y_i$ ($i\ge
2$) are determined uniquely in terms of $(\alpha, y_0, y_1)$. For large $z$ the
solution follows if we also specify $z_c$, with $Y(z)$ diverging as $z^{5/3}$
for high $z$. The four undetermined parameters $(\alpha,y_0,y_1,z_c)$ were
determined by fitting the theory to experimental data taken by a Duke
University group on $^6$Li in an optical trap with a Gaussian potential. The
very best fit of this theory to the data had $\alpha=2.1$, $z_c=4.7$,
$y_0=0.277$, and $y_1=0.0735$, with $\chi^2=0.95$. The corresponding Bertsch
parameter is $\xi_B=0.462(40)$.


title: Is it a power law distribution? The case of economic contractions

abstract:
  One of the first steps to understand and forecast economic downturns is
identifying their frequency distribution, but it remains uncertain. This
problem is common in phenomena displaying power-law-like distributions. Power
laws play a central role in complex systems theory; therefore, the current
limitations in the identification of this distribution in empirical data are a
major obstacle to pursue the insights that the complexity approach offers in
many fields. This paper addresses this issue by introducing a reliable
methodology with a solid theoretical foundation, the Taylor Series-Based Power
Law Range Identification Method. When applied to time series from 39 countries,
this method reveals a well-defined power law in the relative per capita GDP
contractions that span from 5.53% to 50%, comprising 263 events. However, this
observation does not suffice to attribute recessions to some specific
mechanism, such as self-organized criticality. The paper highlights a set of
points requiring more study so as to discriminate among models compatible with
the power law, as needed to develop sound tools for the management of
recessions.

categories: nlin.AO physics.data-an q-fin.GN stat.AP


title: Triality, Structurable and Pre-structurable Algebras

abstract:
  We introduce a notion of Pre-structurable Algebras based upon triality
relations and study its relation to structurable algebra of Allison, as well as
to Lie algebras satisfying triality.


title: Four new X-ray-selected supernova remnants in the Large Magellanic Cloud

abstract:
  Aims: We present a detailed multi-wavelength study of four new supernova
remnants (SNRs) in the Large Magellanic Cloud (LMC). The objects were
identified as SNR candidates in X-ray observations performed during the survey
of the LMC with XMM-Newton.
  Methods: Data obained with XMM-Newton are used to investigate the
morphological and spectral features of the remnants in X-rays. We measure the
plasma conditions, look for supernova (SN) ejecta emission, and constrain some
of the SNR properties (e.g. age and ambient density). We supplement the X-ray
data with optical, infrared, and radio-continuum archival observations, which
allow us to understand the conditions resulting in the current appearance of
the remnants. Based on the spatially-resolved star formation history (SFH) of
the LMC together with the X-ray spectra, we attempt to type the supernovae that
created the remnants.
  Results: We confirm all four objects as SNRs, to which we assign the names
MCSNR J0508-6830, MCSNR J0511-6759, MCSNR J0514-6840, and MCSNR J0517-6759. In
the first two remnants, an X-ray bright plasma is surrounded by very faint [S
II] emission. The emission from the central plasma is dominated by Fe L-shell
lines, and the derived iron abundance is greatly in excess of solar. This
establishes their type Ia (i.e. thermonuclear) SN origin. They appear to be
more evolved versions of other Magellanic Cloud iron-rich SNRs which are
centrally-peaked in X-rays. From the two other remnants (MCSNR J0514-6840 and
MCSNR J0517-6759), we do not see ejecta emission. At all wavelengths at which
they are detected, the local environment plays a key role in their
observational appearance. We present evidence that MCSNR J0517-6759 is close to
and interacting with a molecular cloud, suggesting a massive progenitor.


title:
The Automorphism Group of a Self Dual Binary [72,36,16] Code Does Not
  Contain Z4

abstract:
  It has been proven in a series of works that the order of the automorphism
group of a binary [72,36,16] code does not exceed five. We obtain a
parametrization of all self-dual binary codes of length 72 with automorphism of
order 4 which can be extremal. We use extensive computations in MAGMA and on a
supercomputer to show that an extremal binary code of length 72 does not have
an element of order 4.


title:
An Erd\H{o}s-Ko-Rado theorem for the derangement graph of PGL(3,q)
  acting on the projective plane

abstract:
  In this paper we prove an Erd\H{o}s-Ko-Rado-type theorem for intersecting
sets of permutations. We show that an intersecting set of maximal size in the
projective general linear group PGL(3,q), in its natural action on the points
of the projective line, is either a coset of the stabilizer of a point or a
coset of the stabilizer of a line.


title: Birational geometry of Fano hypersurfaces of index two

abstract:
  We prove that every non-trivial structure of a rationally connected fibre
space (and so every structure of a Mori-Fano fibre space) on a general (in the
sense of Zariski topology) hypersurface of degree $M$ in the
$(M+1)$-dimensional projective space for $M\geq 14$ is given by a pencil of
hyperplane sections. In particular, the variety $V$ is non-rational and its
group of birational self-maps coincide with the group of biregular
automorphisms and is therefore trivial. The proof is based on the techniques of
the method of maximal singularities and the inversion of adjunction.


title: Ergodicity of the tip of an SLE curve

abstract:
  We first prove that, for $\kappa\in(0,4)$, a whole-plane
SLE$(\kappa;\kappa+2)$ trace stopped at a fixed capacity time satisfies
reversibility. We then use this reversibility result to prove that, for
$\kappa\in(0,4)$, a chordal SLE$_\kappa$ curve stopped at a fixed capacity time
can be mapped conformally to the initial segment of a whole-plane
SLE$(\kappa;\kappa+2)$ trace. A similar but weaker result holds for radial
SLE$_\kappa$. These results are then used to study the ergodic behavior of an
SLE curve near its tip point at a fixed capacity time. The proofs rely on the
symmetry of backward SLE laminations and conformal removability of SLE$_\kappa$
curves for $\kappa\in(0,4)$.


title:
Nonstandard Higgs Couplings from Angular Distributions in $h\to Z
  \ell^+\ell^-$

abstract:
  We compute the fully differential rate for the Higgs-boson decay $h\to
Z\ell^+\ell^-$, with $Z\to\ell^{'+}\ell^{'-}$. For these processes we assume
the most general matrix elements within an effective Lagrangian framework. The
electroweak chiral Lagrangian we employ assumes minimal particle content and
Standard Model gauge symmetries, but is otherwise completely general. We
discuss how information on new physics in the decay form factors may be
obtained that is inaccessible in the dilepton-mass spectrum integrated over
angular variables. The form factors are related to the coefficients of the
effective Lagrangian, which are used to estimate the potential size of
new-physics effects.


title:
Local observers on linear Lie groups with linear estimation error
  dynamics

abstract:
  This paper proposes local exponential observers for systems on linear Lie
groups. We study two different classes of systems. In the first class, the full
state of the system evolves on a linear Lie group and is available for
measurement. In the second class, only part of the system's state evolves on a
linear Lie group and this portion of the state is available for measurement. In
each case, we propose two different observer designs. We show that, depending
on the observer chosen, local exponential stability of one of the two
observation error dynamics, left- or right-invariant error dynamics, is
obtained. For the first class of systems these results are developed by showing
that the estimation error dynamics are differentially equivalent to a stable
linear differential equation on a vector space. For the second class of system,
the estimation error dynamics are almost linear. We illustrate these observer
designs on an attitude estimation problem.


title:
Preparation of a three-photon state in a nonlinear cavity - quantum dot
  system

abstract:
  We study theoretically the properties of a three-photon state prepared inside
a semiconductor cavity, due to the interaction between a quantum dot and an
electromagnetic field, and two consecutive spontaneous parametric
downconversion (SPDC) processes. Thus, we consider a scheme involving three
modes of the electromagnetic field, whose frequencies are given by the SPDC
processes: $\omega_0 \rightarrow \omega_1 + \omega_2$, and $\omega_2
\rightarrow \omega_1 + \omega_1$. Furthermore, we study the low excitation
regime, in which a three-photon state is accessible within the system's
dynamics.


title:
Evolution of Planetary Orbits with Stellar Mass Loss and Tidal
  Dissipation

abstract:
  Intermediate mass stars and stellar remnants often host planets, and these
dynamical systems evolve because of mass loss and tides. This paper considers
the combined action of stellar mass loss and tidal dissipation on planetary
orbits in order to determine the conditions required for planetary survival.
Stellar mass loss is included using a so-called Jeans model, described by a
dimensionless mass loss rate \gamma and an index \beta. We use an analogous
prescription to model tidal effects, described here by a dimensionless
dissipation rate \Gamma and two indices (q,p). The initial conditions are
determined by the starting value of angular momentum parameter \eta
(equivalently, the initial eccentricity) and the phase \theta of the orbit.
Within the context of this model, we derive an analytic formula for the
critical dissipation rate \Gamma, which marks the boundary between orbits that
spiral outward due to stellar mass loss and those that spiral inward due to
tidal dissipation. This analytic result
\Gamma=\Gamma(\gamma,\beta,q,p,\eta,\theta) is essentially exact for initially
circular orbits and holds to within an accuracy of 50% over the entire
multi-dimensional parameter space, where the individual parameters vary by
several orders of magnitude. For stars that experience mass loss, the stellar
radius often displays quasi-periodic variations, which produce corresponding
variations in tidal forcing; we generalize the calculation to include such
pulsations using a semi-analytic treatment that holds to the same accuracy as
the non-pulsating case. These results can be used in many applications, e.g.,
to predict/constrain properties of planetary systems orbiting white dwarfs.


title:
On Minimum-time Paths of Bounded Curvature with Position-dependent
  Constraints

abstract:
  We consider the problem of a particle traveling from an initial configuration
to a final configuration (given by a point in the plane along with a prescribed
velocity vector) in minimum time with non-homogeneous velocity and with
constraints on the minimum turning radius of the particle over multiple regions
of the state space. Necessary conditions for optimality of these paths are
derived to characterize the nature of optimal paths, both when the particle is
inside a region and when it crosses boundaries between neighboring regions.
These conditions are used to characterize families of optimal and nonoptimal
paths. Among the optimality conditions, we derive a "refraction" law at the
boundary of the regions that generalizes the so-called Snell's law of
refraction in optics to the case of paths with bounded curvature. Tools
employed to deduce our results include recent principles of optimality for
hybrid systems. The results are validated numerically.


title: BSM Physics: What the Higgs Can Tell Us

abstract:
  This discovery of the Higgs boson last year has created new possibilities for
testing candidate theories for explaining physics beyond the Standard Model.
Here we explain the ways in which new physics can leave its marks in the
experimental Higgs data, and how we can use the data to constrain and compare
different models. In this proceedings paper we use two models, Minimal
Universal Extra Dimensions and the 4D Composite Higgs model, as examples to
demonstrate the technique.


title:
Graphene-based topological insulator with an intrinsic bulk band gap
  above room temperature

abstract:
  Topological insulators (TIs) represent a new quantum state of matter
characterized by robust gapless states inside the insulating bulk gap. The
metallic edge states of a two-dimensional (2D) TI, known as quantum spin Hall
(QSH) effect, are immune to backscattering and carry fully spin-polarized
dissipationless currents. However, existing 2D TIs realized in HgTe and
InAs/GaSb suffer from small bulk gaps (<10 meV) well below room temperature,
thus limiting their application in electronic and spintronic devices. Here, we
report a new 2D TI comprising a graphene layer sandwiched between two Bi2Se3
slabs that exhibits a large intrinsic bulk band gap of 30 to 50 meV, making it
viable for room-temperature applications. Distinct from previous strategies for
enhancing the intrinsic spin-orbit coupling effect of the graphene lattice, the
present graphene-based TI operates on a new mechanism of strong inversion
between graphene Dirac bands and Bi2Se3 conduction bands. Strain engineering
leads to effective control and substantial enhancement of the bulk gap.
Recently reported synthesis of smooth graphene/Bi2Se3 interfaces demonstrates
feasibility of experimental realization of this new 2D TI structure, which
holds great promise for nanoscale device applications.


title: On Galois action in rigid DAHA modules

abstract:
  Given an elliptic curve over a field $K$ of algebraic numbers, we associate
with it an action of the absolute Galois group $G_K$ in the type $A_1$ rigid
DAHA-modules at roots of unity $q$ and over the rings $Z[q^{1/4}]/(p^m)$ for
sufficiently general prime $p$. We describe rigid modules in characteristic
zero and for such rings. The main examples of rigid modules are generalized
nonsymmetric Verlinde algebras; their deformations for arbitrary $q$ are
constructed in this paper, which is of independent interest on its own. The
Galois action preserves the images of the elliptic braid group in the groups of
automorphisms of rigid modules over $Z[q^{1/4}]/(p^m)$. If they are finite in
characteristic zero, then $G_K$ acts there and no reduction modulo $(p^m)$ is
needed; we find all such cases. In the case of $3$-dimensional DAHA-modules,
these images are quotients of equilateral triangle groups directly related to
the Livn\'e groups. Also, this paper can be viewed as an extension of the DAHA
theory of refined Jones polynomials of torus knots (for $A_1$) to $G_K$.


title: Real multiplication curves by subfields of cyclotomic fields

abstract:
  In \emph{Endomorphism Algebras of Jacobians}, Ellenberg gives group theory
tools to construct jacobians of curves with real multiplication. He shows the
existence of curves and family of curves with real multiplication by subfields
of cyclotomic fields. Among them, some are already known such as the family of
Mestre, or the family of Tautz, Top and Verberkmoes. In this article, we give
explicit families of real multiplication curves, for each case Ellenberg showed
their existence.


abstract:
  Differential difference algebras were introduced by Mansfield and Szanto,
which arose naturally from differential difference equations. In this paper, we
investigate the Gelfand-Kirillov dimension of differential difference algebras.
We give a lower bound of the Gelfand-Kirillov dimension of a differential
difference algebra and a sufficient condition under which the lower bound is
reached; we also find an upper bound of this Gelfand-Kirillov dimension under
some specific conditions and construct an example to show that this upper bound
can not be sharpened any more.


title: On lacunary Toeplitz determinants

abstract:
  By using Riemann--Hilbert problem based techniques, we obtain the asymptotic
expansion of lacunary Toeplitz determinants $\det_N\big[ c_{\ell_a-m_b}[f]
\big]$ generated by holomorhpic symbols, where $\ell_a=a$ (resp. $m_b=b$)
except for a finite subset of indices $a=h_1,\dots, h_n$ (resp. $b=t_1,\dots,
t_r$). In addition to the usual Szeg\"{o} asymptotics, our answer involves a
determinant of size $n+r$.


title:
The Local Langlands Correspondence for Simple Supercuspidal
  Representations of GL_n(F)

abstract:
  Let F be a non-archimedean local field of characteristic zero with residual
characteristic p. In this paper, we present a simple proof and construction of
the local Langlands correspondence for simple supercuspidal representations of
GL_n(F), when p does not divide n. As an application, we prove Jacquet's
conjecture on the local converse problem for GL_n(F) in the case of simple
supercuspidal representations, for arbitrary p.


title:
Practical Reduction of Edge Flip Sequences in Two-Dimensional
  Triangulations

abstract:
  The development of laser scanning techniques has popularized the
representation of 3D shapes by triangular meshes with a large number of
vertices. Compression techniques dedicated to such meshes have emerged, which
exploit the idea that the connectivity of a dense mesh does not deviate much
from the connectivity that can be constructed automatically from the vertex
positions (while possibly being guided by additional codes). The edge flip is
one of the tools that can encode the differences between two meshes, and it is
important to control the length of a sequence of flips that transform one
triangulation into another. This paper provides a practical solution to this
problem. Indeed, the problem of determining a minimal sequence of edge flips
between two triangulations is NP-complete for some types of triangulations
including manifold triangulations of surfaces, so that it is necessary to
develop heuristics. Moreover, it is sometimes difficult to establish a first
sequence of flips between two meshes, and we advocate a solution based on the
reduction of an existing sequence. The new approach we propose is founded on
the assignment of labels to identify the edges, with a property of label
transfer during a flip. This gives a meaning to the tracking of an edge in a
sequence of flips and offers the exploitation of very simple combinatorial
properties. All the operations are performed directly on the sequence of labels
denoting the edges to be flipped, almost regardless of the underlying surface,
since only local temporary connectivity is involved.


title:
Crystal and Magnetic Structure of CaCo{1.86}As2 Studied by X-ray and
  Neutron Diffraction

abstract:
  Neutron and x-ray diffraction measurements are presented for powders and
single crystals of CaCo{1.86}As2. The crystal structure is a
collapsed-tetragonal ThCr2Si2-type structure as previously reported, but with
7(1)% vacancies on the Co sites corresponding to the composition
CaCo{1.86(2)}As2. The thermal expansion coefficients for both the a- and c-axes
are positive from 10 to 300 K. Neutron diffraction measurements on single
crystals demonstrate the onset of A-type collinear antiferromagnetic order
below the Neel temperature TN = 52(1) K with the ordered moments directed along
the tetragonal c-axis, aligned ferromagnetically in the ab-plane and
antiferromagnetically stacked along the c-axis.


title: Supersymmetry Searches with Multiple b-jets at CMS

abstract:
  Recent results from CMS are reviewed for searches for supersymmetry in final
states with multiple bottom quark jets. Results are based on the full 2012 CMS
dataset consisting of 19.5 fb-1 collected at a center-of-mass energy of sqrt(s)
= 8 TeV. In particular, searches for final states with multiple b-jets and one
or two leptons are presented. These final states are of special interest in the
context of the search for third generation squarks in gluino or sbottom cascade
decays, as predicted by natural supersymmetry.


title: Geometry induced pair condensation

abstract:
  We study a one-dimensional model of interacting bosons on a lattice with two
flat bands. Regular condensation is suppressed due to the absence of a well
defined minimum in the single particle spectrum. We find that interactions
stabilize a number of non-trivial phases like a pair (quasi-) condensate, a
supersolid at incommensurable fillings and valence bond crystals at
commensurability. We support our analytical calculations with numerical
simulations using the density matrix renormalization group technique.
Implications for cold-atoms and extensions to higher dimensions are discussed.


title:
High Stellar FUV/NUV Ratio and Oxygen Contents in the Atmospheres of
  Potentially Habitable Planets

abstract:
  Recent observations of several planet-hosting M dwarfs show that most have
FUV/NUV flux ratios 1000 times greater than that of the Sun. Here we show that
the atmospheric oxygen contents (O2 and O3) of potentially habitable planets in
this type of UV environment could be 2~3 orders of magnitude greater than those
of their counterparts around Sun-like stars as a result of decreased photolysis
of O3, H2O2, and HO2. Thus detectable levels of atmospheric oxygen, in
combination with the existence of H2O and CO2, may not be the most promising
biosignatures on planets around stars with high FUV/NUV ratios such as the
observed M dwarfs.


title:
Constants of motion for the magnetic force: the angular momentum and the
  Laplace-Runge-Lenz vector

abstract:
  It is well-known that an electric charge under a uniform magnetic field has a
bidimensional motion if its initial position and velocity are perpendicular to
this magnetic field. Although some constants of motion, as the energy and
angular momentum, have been identified for this system, its features hide
others. In this work, we build generalizations of the angular momentum and the
Laplace-Runge-Lenz vector and show that these vectors are constants of motion.
Moreover, from them, we find four dynamically independent conserved qualities.


title: Consensus and Coherence in Fractal Networks

abstract:
  We consider first and second order consensus algorithms in networks with
stochastic disturbances. We quantify the deviation from consensus using the
notion of network coherence, which can be expressed as an $H_2$ norm of the
stochastic system. We use the setting of fractal networks to investigate the
question of whether a purely topological measure, such as the fractal
dimension, can capture the asymptotics of coherence in the large system size
limit. Our analysis for first-order systems is facilitated by connections
between first-order stochastic consensus and the global mean first passage time
of random walks. We then show how to apply similar techniques to analyze
second-order stochastic consensus systems. Our analysis reveals that two
networks with the same fractal dimension can exhibit different asymptotic
scalings for network coherence. Thus, this topological characterization of the
network does not uniquely determine coherence behavior. The question of whether
the performance of stochastic consensus algorithms in large networks can be
captured by purely topological measures, such as the spatial dimension, remains
open.


title: CMS results on soft diffraction

abstract:
  We present measurements of soft single- and double-diffractive cross
sections, as well as of forward rapidity gap cross sections at 7 TeV at the
LHC, and compare the results to other measurements and to theoretical
predictions implemented in various Monte Carlo simulations.


title: Three-point correlation functions in Yang-Mills theory

abstract:
  We investigate the three-point correlation functions of Yang-Mills theory in
the Landau gauge, with a particular emphasis on the infrared regime. The effect
of the Gribov copies is accounted for by adding a mass term for the gluons in
the Faddeev-Popov action in the Landau gauge. We perform a one-loop calculation
for the ghost-antighost-gluon and three-gluon correlation functions. These
analytic results are compared with the available lattice data and give a very
satisfying agreement.


title: Search for Stable Magnetohydrodynamic Equilibria in Barotropic Stars

abstract:
  It is now believed that magnetohydrodynamic equilibria can exist in stably
stratified stars due to the seminal works of Braithwaite & Spruit (2004) and
Braithwaite & Nordlund (2006). What is still not known is whether
magnetohydrodynamic equilibria can exist in a barotropic star, in which stable
stratification is not present. It has been conjectured by Reisenegger (2009)
that there will likely not exist any magnetohydrodynamical equilibria in
barotropic stars. We aim to test this claim by presenting preliminary MHD
simulations of barotropic stars using the three dimensional stagger code of
Nordlund & Galsgaard (1995).


title: The Herbig Ae Star PDS2

abstract:
  We present a preliminary abundance analysis of the isolated Herbig Ae star
PDS2 (CD -53 251, 2MASS J01174349-5233307). Our adopted model has Teff = 6500K,
log(g) = 3.5. It is likely that PDS2 belongs to the class of young stars with
abundances resembling the Lambda Bootis stars.


title:
CXOGBS~J173620.2--293338: A Candidate Symbiotic X-ray Binary Associated
  with a Bulge Carbon Star

abstract:
  The Galactic Bulge Survey is a wide but shallow X-ray survey of regions above
and below the Plane in the Galactic Bulge. It was performed using the Chandra
X-ray Observatory's ACIS camera. The survey is primarily designed to find and
classify low luminosity X-ray binaries. The combination of the X-ray depth of
the survey and the accessibility of optical and infrared counterparts makes
this survey ideally suited to identification of new symbiotic X-ray binaries in
the Bulge. We consider the specific case of the X-ray source CXOGBS
J173620.2-293338. It is coincident to within 1 arcsec with a very red star,
showing a carbon star spectrum and irregular variability in the Optical
Gravitational Lensing Experiment data. We classify the star as a late C-R type
carbon star based on its spectral features, photometric properties, and
variability characteristics, although a low-luminosity C-N type cannot be ruled
out. The brightness of the star implies it is located in the Bulge, and its
photometric properties overall are consistent with the Bulge carbon star
population. Given the rarity of carbon stars in the Bulge, we estimate the
probability of such a close chance alignment of any Galactic Bulge Survey
source with a carbon star to be <1e-3 suggesting that this is likely to be a
real match. If the X-ray source is indeed associated with the carbon star, then
the X-ray luminosity is around 9e32 erg/s. Its characteristics are consistent
with a low luminosity symbiotic X-ray binary, or possibly a low accretion rate
white dwarf symbiotic.


title: Statistical Mechanics of Inference

abstract:
  Statistical modeling often involves identifying an optimal estimate to some
underlying probability distribution known to satisfy some given constraints. I
show here that choosing as estimate the centroid, or center of mass, of the set
consistent with the constraints formally minimizes an objective measure of the
expected error. Further, I obtain a useful approximation to this point, valid
in the thermodynamic limit, that immediately provides much information relating
to the full solution set's geometry. For weak constraints, the centroid is
close to the popular maximum entropy solution, whereas for strong constraints
the two are far apart. Because of this, centroid inference is often
substantially more accurate. The results I present allow for its
straightforward application.


title: Weak backward error analysis for Langevin process

abstract:
  We consider numerical approximations of stochastic Langevin equations by
implicit methods. We show a weak backward error analysis result in the sense
that the generator associated with the numerical solution coincides with the
solution of a modified Kolmogorov equation up to high order terms with respect
to the stepsize. This implies that every measure of the numerical scheme is
close to a modified invariant measure obtained by asymptotic expansion.
Moreover, we prove that, up to negligible terms, the dynamic associated with
the implicit scheme considered is exponentially mixing.


title:
Gas and dust productions of comet 103P/Hartley 2 from millimetre
  observations: interpreting rotation-induced time variations

abstract:
  Comet 103P/Hartley 2 made a close approach to the Earth in October 2010. It
was the target of an extensive observing campaign and was visited by the Deep
Impact spacecraft (mission EPOXI). We present observations of HCN and CH3OH
emission lines conducted with the IRAM Plateau de Bure interferometer on 22-23,
28 October and 4, 5 November 2010 at 1.1, 1.9 and 3.4 mm wavelengths. The
thermal emission from the dust coma and nucleus is detected simultaneously.
Interferometric images with unprecedented spatial resolution are obtained. A
sine-wave variation of the thermal continuum is observed in the 23 October
data, that we associate with the nucleus thermal light curve. The nucleus
contributes up to 30-55 % of the observed continuum. The large dust-to-gas
ratio (in the range 2-6) can be explained by the unusual activity of the comet
for its size, which allows decimeter size particles and large boulders to be
entrained by the gas. The rotational temperature of CH3OH is measured. We
attribute the increase from 35 to 46 K with increasing beam size (from 150 to
1500 km) to radiative processes. The HCN production rate displays strong
rotation-induced variations. The HCN production curve, as well as those of CO2
and H2O measured by EPOXI, are interpreted with a geometric model which takes
into account the rotation and the shape of the comet. The HCN and H2O
production curves are in phase, showing common sources. The 1.7h delay, in
average, of HCN and H2O with respect to the CO2 production curve suggests that
HCN and H2O are mainly produced by subliming icy grains. The scale length of
production of HCN is determined to be on the order of 500-1000 km, implying a
mean velocity of 100-200 m/s for the icy grains producing HCN. The modulation
of the CO2 prouction and of the velocity offset of the HCN lines are
interpreted in terms of localized sources of gas on the nucleus surface.


title:
Monte Carlo Simulations of the LARES space experiment to test General
  Relativity and fundamental physics

abstract:
  The LARES (LAser RElativity Satellite) satellite was successfully launched in
February 2012. The LARES space experiment is based on the orbital
determinations of the laser ranged satellites LARES, LAGEOS (LAser GEOdynamics
Satellite) and LAGEOS 2 together with the determination of the Earth's gravity
field by the GRACE (Gravity Recovery And Climate Experiment) mission. It will
test some fundamental physics predictions and provide accurate measurements of
the framedragging effect predicted by Einstein's theory of General Relativity.
By one hundred Monte Carlo simulations of the LARES experiment, with
simulations of the orbits of LARES, LAGEOS and LAGEOS 2 according to the latest
GRACE gravity field determinations, we found that the systematic errors in the
measurement of framedragging amount to about 1.4% of the general relativistic
effect, confirming previous error analyses.


title: Experimental test of the "special state" theory of quantum measurement

abstract:
  An experimental test of the "special state" theory of quantum measurement is
proposed. It should be feasible with present-day laboratory equipment and
involves a slightly elaborated Stern-Gerlach setup.
  The "special state" theory is conservative with respect to quantum mechanics,
but radical with respect to statistical mechanics, in particular regarding the
arrow of time. In this article background material is given on both quantum
measurement and statistical mechanics aspects. For example, it is shown that
future boundary conditions would not contradict experience, indicating that the
fundamental equal-a-priori-probability assumption at the foundations of
statistical mechanics is far too strong (since future conditioning reduces the
class of allowed states).
  The test is based on a feature of this theory that was found necessary in
order to recover standard (Born) probabilities in quantum measurements.
Specifically, certain systems should have "noise" whose amplitude follows the
long-tailed Cauchy distribution. This distribution is marked by the occasional
occurrence of extremely large signals as well as a non-self-averaging property.
The proposed test is a variant of the Stern-Gerlach experiment in which
protocols are devised, some of which will require the presence of this noise,
some of which will not. The likely observational schemes would involve the
distinction between detection and non-detection of that "noise". The signal to
be detected (or not) would be either single photons in the visible and UV range
or electric fields (and related excitations) in the neighborhood of the ends of
the magnets.


title: On the asymptotics of dimers on tori

abstract:
  We study asymptotics of the dimer model on large toric graphs. Let $\mathbb
L$ be a weighted $\mathbb{Z}^2$-periodic planar graph, and let $\mathbb{Z}^2 E$
be a large-index sublattice of $\mathbb{Z}^2$. For $\mathbb L$ bipartite we
show that the dimer partition function on the quotient
$\mathbb{L}/(\mathbb{Z}^2 E)$ has the asymptotic expansion $\exp[A f_0 +
\text{fsc} + o(1)]$, where $A$ is the area of $\mathbb{L}/(\mathbb{Z}^2 E)$,
$f_0$ is the free energy density in the bulk, and $\text{fsc}$ is a finite-size
correction term depending only on the conformal shape of the domain together
with some parity-type information. Assuming a conjectural condition on the zero
locus of the dimer characteristic polynomial, we show that an analogous
expansion holds for $\mathbb{L}$ non-bipartite. The functional form of the
finite-size correction differs between the two classes, but is universal within
each class. Our calculations yield new information concerning the distribution
of the number of loops winding around the torus in the associated double-dimer
models.


title:
Combined Analysis of Hubble and VLT Photometry of the Intermediate Mass
  Black Hole ESO 243-49 HLX-1

abstract:
  In this paper we present a combined analysis of data obtained with the Hubble
Space Telescope (HST), Very Large Telescope (VLT), and Swift X-ray telescope
(XRT) of the intermediate mass black hole ESO 243-49 HLX-1 that were taken 2
months apart between September and November 2010. Previous separate analyses of
these data found that they were consistent with an irradiated accretion disc
with contribution from either a very young or very old stellar population, and
also indicated that the optical flux of the HLX-1 counterpart could be
variable. Such variability could only be attributed to a varying accretion
disc, so simultaneous analysis of all data sets should break the degeneracies
in the model fits. We thus simultaneously fit the broad-band spectral energy
distribution (SED) from near-infrared through to X-ray wavelengths of the two
epochs of data with a model consisting of an irradiated accretion disc and a
stellar population. We show that this combined analysis rules out an old
stellar population, finding that the SED is dominated by emission from an
accretion disc with moderate reprocessing in the outer disc around an
intermediate mass black hole imbedded in a young (20 Myr) stellar cluster with
a mass of 1E5 Msun. We also place an upper limit on the mass of an additional
hidden old stellar population of 1E6 Msun. However, optical r-band observations
of HLX-1 obtained with the Gemini-South telescope covering part of the decay
from a later X-ray outburst are consistent with constant optical flux,
indicating that the observed variability between the HST and VLT observations
could be spurious caused by differences in the background subtraction applied
to the two optical data sets. In this scenario the contribution of the stellar
population, and thus the stellar mass of the cluster, may be higher (abridged).


title: Modeling surface magnetic fields in stars with radiative envelopes

abstract:
  Stars with radiative envelopes, specifically the upper main sequence
chemically peculiar (Ap) stars, were among the first objects outside our solar
system for which surface magnetic fields have been detected. Currently magnetic
Ap stars remains the only class of stars for which high-resolution measurements
of both linear and circular polarization in individual spectral lines are
feasible. Consequently, these stars provide unique opportunities to study the
physics of polarized radiative transfer in stellar atmospheres, to analyze in
detail stellar magnetic field topologies and their relation to starspots, and
to test different methodologies of stellar magnetic field mapping. Here I
present an overview of different approaches to modeling the surface fields in
magnetic A- and B-type stars. In particular, I summarize the ongoing efforts to
interpret high-resolution full Stokes vector spectra of these stars using
magnetic Doppler imaging. These studies reveal an unexpected complexity of the
magnetic field geometries in some Ap stars.


title: Bayesian inference for pulsar timing models

abstract:
  The extremely regular, periodic radio emission from millisecond pulsars makes
them useful tools for studying neutron star astrophysics, general relativity,
and low-frequency gravitational waves. These studies require that the observed
pulse times of arrival be fit to complex timing models that describe numerous
effects such as the astrometry of the source, the evolution of the pulsar's
spin, the presence of a binary companion, and the propagation of the pulses
through the interstellar medium. In this paper, we discuss the benefits of
using Bayesian inference to obtain pulsar timing solutions. These benefits
include the validation of linearized least-squares model fits when they are
correct, and the proper characterization of parameter uncertainties when they
are not; the incorporation of prior parameter information and of models of
correlated noise; and the Bayesian comparison of alternative timing models. We
describe our computational setup, which combines the timing models of Tempo2
with the nested-sampling integrator MultiNest. We compare the timing solutions
generated using Bayesian inference and linearized least-squares for three
pulsars: B1953+29, J2317+1439, and J1640+2224, which demonstrate a variety of
the benefits that we posit.


title: The SLUGGS Survey: Wide-field Stellar Kinematics of Early-type Galaxies

abstract:
  We present stellar kinematics of 22 nearby early-type galaxies (ETGs), based
on two-dimensional (2D) absorption line stellar spectroscopy out to ~2-4 R_e
(effective radii), as part of the ongoing SLUGGS Survey. The galaxies span a
factor of 20 in intrinsic luminosity, as well as a full range of environment
and ETG morphology. Our data consist of good velocity resolution (sigma_inst ~
25 km/s) integrated stellar-light spectra extracted from the individual
slitlets of custom made Keck/DEIMOS slitmasks. We extract stellar kinematics
measurements (V, sigma, h_3, and h_4) for each galaxy. Combining with
literature values from smaller radii, we present 2D spatially resolved maps of
the large-scale kinematic structure in each galaxy. We find that the kinematic
homogeneity found inside 1 R_e often breaks down at larger radii, where a
variety of kinematic behaviors are observed. While central slow rotators remain
slowly rotating in their halos, central fast rotators show more diversity,
ranging from rapidly increasing to rapidly declining specific angular momentum
profiles in the outer regions. There are indications that the outer trends
depend on morphological type, raising questions about the proposed unification
of the elliptical and lenticular (S0) galaxy families in the ATLAS^3D survey.
Several galaxies in our sample show multiple lines of evidence for distinct
disk components embedded in more slowly rotating spheroids, and we suggest a
joint photometric-kinematic approach for robust bulge-disk decomposition. Our
observational results appear generally consistent with a picture of two-phase
(in-situ plus accretion) galaxy formation.


title: Baryogenesis Once More, Inside LHC

abstract:
  We investigate the feasibility of directly detecting a generation mechanism
of the cosmic baryon asymmetry, by repeating the same particle physics process
inside the LHC. We propose a framework with R-parity and CP violating squark
decays responsible for baryogenesis, which can be embedded in supersymmetric
models and is partly motivated by naturalness. We argue that the baryon number
generation here is closely related to lepton charge asymmetry on the resonance.
We emphasize the importance of the single charged lepton plus multijet channel
in the absence of significant missing energy in search of such a scenario.


title: Small Field Inflation and the Spectral Index

abstract:
  It is sometimes stated that $n_s = 0.98$ in hybrid inflation; sometimes that
it predicts $n_s >1$. A number of authors have consider aspects of Planck scale
corrections and argued that they affect these predictions. Here we consider
these systematically, describing the situations which can yield $n_s =0.96$,
and the extent to which this result requires additional tuning.


title: Holographic plasma and anyonic fluids

abstract:
  We use alternative quantisation of the $D3/D5$ system to explore properties
of a strongly coupled charged plasma and strongly coupled anyonic fluids. The
$S$-transform of the $D3/D5$ system is used as a model for charged matter
interacting with a U(1) gauge field in the large coupling regime, and we
compute the dispersion relationship of the propagating electromagnetic modes as
the density and temperature are changed. A more general $SL(2,\mathbb{Z})$
transformation gives a strongly interacting anyonic fluid, and we study its
transport properties as we change the statistics of the anyons and the
background magnetic field.


title: 1/N^2 corrections to the holographic Weyl anomaly

abstract:
  We compute the O(1) contribution to holographic c-a for IIB supergravity on
AdS_5 x S^5/Z_n and on AdS_5 x T^{1,1}/Z_n. In both cases, we find agreement
with the dual field theory results, thus providing 1/N^2 checks of AdS/CFT with
reduced supersymmetry. Since the holographic computation involves a sum over
shortened multiplets in the KK tower, we provide some details on the S^5 and
T^{1,1} spectra in a form that is convenient when considering their Z_n
orbifolds. The computation for the even Z_n orbifolds of S^5 includes a sum
over the multiplets in the twisted sector that is essential for obtaining
agreement with the dual field theory.


title:
Stellar clusters in the inner Galaxy and their correlation with cold
  dust emission

abstract:
  Stars are born within dense clumps of giant molecular clouds, constituting
young stellar agglomerates known as embedded clusters, which only evolve into
bound open clusters under special conditions. We statistically study all
embedded clusters (ECs) and open clusters (OCs) known so far in the inner
Galaxy, investigating particularly their interaction with the surrounding
molecular environment and the differences in their evolution. We first compiled
a merged list of 3904 clusters from optical and infrared clusters catalogs in
the literature, including 75 new (mostly embedded) clusters discovered by us in
the GLIMPSE survey. From this list, 695 clusters are within the Galactic range
|l| < 60 deg and |b| < 1.5 deg covered by the ATLASGAL survey, which was used
to search for correlations with submm dust continuum emission tracing dense
molecular gas. We defined an evolutionary sequence of five morphological types:
deeply embedded cluster (EC1), partially embedded cluster (EC2), emerging open
cluster (OC0), OC still associated with a submm clump in the vicinity (OC1),
and OC without correlation with ATLASGAL emission (OC2). Together with this
process, we performed a thorough literature survey of these 695 clusters,
compiling a considerable number of physical and observational properties in a
catalog that is publicly available. We found that an OC defined observationally
as OC0, OC1, or OC2 and confirmed as a real cluster is equivalent to the
physical concept of OC (a bound exposed cluster) for ages in excess of ~16 Myr.
Some observed OCs younger than this limit can actually be unbound associations.
We found that our OC and EC samples are roughly complete up to ~1 kpc and ~1.8
kpc from the Sun, respectively, beyond which the completeness decays
exponentially. Using available age estimates for a few ECs, we derived an upper
limit of 3 Myr for the duration of the embedded phase... (Abridged)


title:
A lithium depletion boundary age of 21 Myr for the Beta Pictoris moving
  group

abstract:
  Optical spectroscopy is used to confirm membership for 8 low-mass candidates
in the young Beta Pic moving group (BPMG) via their radial velocities,
chromospheric activity and kinematic parallaxes. We searched for the presence
of the Li I 6708A resonance feature and combined the results with literature
measurements of other BPMG members to find the age-dependent lithium depletion
boundary (LDB) -- the luminosity at which Li remains unburned in a coeval
group. The LDB age of the BPMG is 21 +/- 4 Myr and insensitive to the choice of
low-mass evolutionary models. This age is more precise, likely to be more
accurate, and much older than that commonly assumed for the BPMG. As a result,
substellar and planetary companions of BPMG members will be more massive than
previously thought.


title:
Super and Massive AGB Stars: II - Nucleosynthesis and Yields - Z=0.02,
  0.008 and 0.004

abstract:
  We have computed detailed evolution and nucleosynthesis models for super and
massive AGB stars over the mass range 6.5-9.0 Msun in divisions of 0.5 Msun
with metallicities Z=0.02, 0.008 and 0.004. These calculations, in which we
find third dredge-up and hot bottom burning, fill the gap between existing low
and intermediate-mass AGB star models and high mass star models that become
supernovae. For the considered metallicities, the composition of the yields is
largely dominated by the thermodynamic conditions at the base of the convective
envelope rather than by the pollution arising from third dredge up. We
investigate the effects of various uncertainties, related to the mass-loss
rate, mixing length parameter, and the treatment of evolution after the
envelope instability that develops near the end of the (Super)AGB phase.
Varying these parameters alter the yields mainly because of their impact on the
amount of third dredge up enrichment, and to a lesser extent on the hot bottom
burning conditions. Our models produce significant amounts of He4, Li7
(depending on the mass-loss formulation) C13, N14, O17, Na23, Mg25, as well the
radioactive isotope Al26 in agreement with previous investigation. In addition
our results show enrichment of Ne22, Mg26 and Fe60, as well as a substantial
increase in our proxy neutron capture species representing all species heavier
than iron. These stars may provide important contributions to the Galaxy's
inventory of the heavier Mg isotopes, N14, Li7 and Al27.


title:
Sensitive CO and 13CO survey of water fountain stars. Detections towards
  IRAS 18460-0151 and IRAS 18596+0315

abstract:
  Water fountain stars represent a stage between the asymptotic giant branch
(AGB) and planetary nebulae phases, when the mass loss changes from spherical
to bipolar. These types of evolved objects are characterized by high-velocity
jets in the 22 GHz water maser emission. We surveyed the CO and 13CO line
emission towards a sample of ten water fountain stars through observing the
J=1-0 and 2-1 lines of CO and 13CO, using the 30m IRAM radio telescope at Pico
Veleta. All the water fountains visible from the observatory were surveyed.
Most of the line emission arises from foreground or background Galactic clouds,
and we had to thoroughly analyse the spectra to unveil the velocity components
related to the stars. In two sources, IRAS 18460-0151 and IRAS 18596+0315, we
identified wide velocity components with a width of 35-40 km/s that are centred
at the stellar velocities. These wide components can be associated with the
former AGB envelope of the progenitor star. A third case, IRAS 18286-0959, is
reported as tentative; in this case a pair of narrow velocity components,
symmetrically located with respect to the stellar velocity, has been
discovered. We also modelled the line emission using an LVG code and derived
some global physical parameters, which allowed us to discuss the possible
origin of this gas in relation to the known bipolar outflows. For IRAS
18460-0151 and IRAS 18596+0315, we derived molecular masses close to 0.2 solar
masses, mean densities of 10^4 cm^{-3}, and mass-loss rates of 10^{-4}
M_sun/yr. The kinetic temperatures are rather low, between 10 and 50 K in both
cases, which suggests that the CO emission is arising from the outer and cooler
regions of the envelopes. No fitting was possible for IRAS 18286-0959, because
line contamination can not be discarded in this case.


title:
Angular momentum redistribution by SASI spiral modes and consequences
  for neutron star spins

abstract:
  In the collapsing core of massive stars, the standing accretion shock
instability (SASI) can drive spiral modes that efficiently redistribute angular
momentum. This process can impart a spin to the forming neutron star even when
the progenitor star is non-rotating. Here we develop the first analytical
description of the angular momentum redistribution driven by a spiral mode of
the SASI. Our analysis, valid in the limit of small mode amplitude, shows that
the angular momentum separation is driven by the Reynolds stress generated by
the spiral mode. The resulting solutions compare favorably with previous
three-dimensional hydrodynamic simulations of the SASI in the linear and weakly
non-linear phases. Reasonable agreement is also found when extrapolating the
solutions into the fully non-linear phase. A Reynolds-decomposition of the flow
is performed in the saturated state of these simulations, showing that outward
angular momentum transport by the Reynolds stress and the fluctuating component
of the mass flux balance inward transport by advection. We derive an
approximate analytic expression for the maximum angular momentum deposited in
the neutron star as a function of the mass accretion rate, shock radius, shock
compression ratio, and amplitude of the spiral mode at the time of explosion.
Implications for the birth spin periods of neutron stars are discussed.


title: Flavor and Collider Signatures of Asymmetric Dark Matter

abstract:
  We consider flavor constraints on, and collider signatures of, Asymmetric
Dark Matter (ADM) via higher dimension operators. In the supersymmetric models
we consider, R-parity violating (RPV) operators carrying B-L interact with n
dark matter (DM) particles X through an interaction of the form W = X^n
O_{B-L}, where O_{B-L} = q l d^c, u^c d^c d^c, l l e^c. This interaction
ensures that the lightest ordinary supersymmetric particle (LOSP) is unstable
to decay into the X sector, leading to a higher multiplicity of final state
particles and reduced missing energy at a collider. Flavor-violating processes
place constraints on the scale of the higher dimension operator, impacting
whether the LOSP decays promptly. While the strongest limitations on RPV from
n-\bar{n} oscillations and proton decay do not apply to ADM, we analyze the
constraints from meson mixing, mu-e conversion, mu -> 3 e and b -> s l^+ l^-.
We show that these flavor constraints, even in the absence of flavor
symmetries, allow parameter space for prompt decay to the X sector, with
additional jets and leptons in exotic flavor combinations. We study the
constraints from existing 8 TeV LHC SUSY searches with (i) 2-6 jets plus
missing energy, and (ii) 1-2 leptons, 3-6 jets plus missing energy, comparing
the constraints on ADM-extended supersymmetry with the usual supersymmetric
simplified models.


title:
On the relation between Seyfert 2 accretion rate and environment at z <
  0.1

abstract:
  We analyse different properties of the small scale environment of Seyfert 2
for two samples selected according to the accretion rate parameter, R, from the
DR7-SDSS survey. We compare the results with two control samples of non-active
galaxies that cover the same redshift range, luminosity, colours, morphology,
age and stellar mass content. Our study shows that both high and low accretion
rate subsamples reside in bluer and lower density environments than the control
samples. However, we find that this difference is at least two times stronger
for the low accretion rate Seyferts.
  In the vicinity of Seyfert 2, red galaxies have systematically lower values
of stellar-mass as compared with corresponding control samples. The lower
values of stellar mass for red neighbours is more significant at higher density
environments and it is more evident for low accretion rate Seyfert. We also
find that this effect is independent of the host's stellar mass.
  Our results are consistent with a scenario where AGN occurrence is higher in
lower/medium density environments with a higher merger rate and a lack of a
dense intergalactic medium (that can strip gas from these systems) that provide
suitable conditions for the central black hole feeding. We find this
particularly evident for the low accretion rate Seyferts that could compensate
through the intergalactic medium the lack of gas of their hosts.


title: Information Relaxation is Ultradiffusive

abstract:
  We investigate how the overall response to a piece of information (a story or
an article) evolves and relaxes as a function of time in social networks like
Reddit, Digg and Youtube. This response or popularity is measured in terms of
the number of votes/comments that the story (or article) accrued over time. We
find that the temporal evolution of popularity can be described by a universal
function whose parameters depend upon the system under consideration. Unlike
most previous studies, which empirically investigated the dynamics of voting
behavior, we also give a theoretical interpretation of the observed behavior
using ultradiffusion.
  Whether it is the inter-arrival time between two consecutive votes on a story
on Reddit or the comments on a video shared on Youtube, there is always a
hierarchy of time scales in information propagation. One vote/comment might
occur almost simultaneously with the previous, whereas another vote/comment
might occur hours after the preceding one. This hierarchy of time scales leads
us to believe that the dynamical response of users to information is
ultradiffusive in nature. We show that a ultradiffusion based stochastic
process can be used to rationalize the observed temporal evolution.


title:
Effect of Temperature and Charged Particle Fluence on the Resistivity of
  Polycrystalline CVD Diamond Sensors

abstract:
  The resistivity of polycrystalline chemical vapor deposition diamond sensors
is studied in samples exposed to fluences relevant to the environment of the
High Luminosity Large Hadron Collider. We measure the leakage current for a
range of bias voltages on samples irradiated with 800 MeV protons up to
1.6\times 10^{16} p/cm^2. The proton beam at LANSCE, Los Alamos National
Laboratory, was applied to irradiate the samples. The devices' resistivity is
extracted for temperatures in the -10^\circC to +20^\circC range.


title: Revisiting slepton pair production at the Large Hadron Collider

abstract:
  Motivated by the shift in experimental attention towards electroweak
supersymmetric particle production at the CERN LHC, we update in this paper our
precision predictions at next-to-leading order of perturbative QCD matched to
resummation at the next-to-leading logarithmic accuracy for direct slepton pair
production in proton-proton collisions. Simplified models, now commonly adopted
by the experimental collaborations for selectrons and smuons as well as mixing
staus, are used as benchmarks for total cross sections at achieved and future
center-of-mass energies. They are presented together with the corresponding
scale and parton density uncertainties in graphical and tabular form for future
reference. Using modern Monte Carlo techniques, we also reanalyze recent ATLAS
and CMS slepton searches in light of our precision cross sections and for
various assumptions on the decomposition of the sleptons and their neutralino
decay products.


title:
Modeling of Laser wakefield acceleration in Lorentz boosted frame using
  EM-PIC code with spectral solver

abstract:
  Simulating laser wakefield acceleration (LWFA) in a Lorentz boosted frame in
which the plasma drifts towards the laser with $v_b$ can speedup the simulation
by factors of $\gamma^2_b=(1-v^2_b/c^2)^{-1}$. In these simulations the
relativistic drifting plasma inevitably induces a high frequency numerical
instability that contaminates the interested physics. Various approaches have
been proposed to mitigate this instability. One approach is to solve Maxwell
equations in Fourier space (a spectral solver) as this has been shown to
suppress the fastest growing modes of this instability in simple test problems
using a simple low pass, ring (in two dimensions), or shell (in three
dimensions) filter in Fourier space. We describe the development of a fully
parallelized, multi-dimensional, particle-in-cell code that uses a spectral
solver to solve Maxwell's equations and that includes the ability to launch a
laser using a moving antenna. This new EM-PIC code is called UPIC-EMMA and it
is based on the components of the UCLA PIC framework (UPIC). We show that by
using UPIC-EMMA, LWFA simulations in the boosted frames with arbitrary
$\gamma_b$ can be conducted without the presence of the numerical instability.
We also compare the results of a few LWFA cases for several values of
$\gamma_b$, including lab frame simulations using OSIRIS, a EM-PIC code with a
finite difference time domain (FDTD) Maxwell solver. These comparisons include
cases in both linear, and nonlinear regimes. We also investigate some issues
associated with numerical dispersion in lab and boosted frame simulations and
between FDTD and spectral solvers.