title:
Comparing symmetry restoration trends for meson masses and mixing angles
  in the QCD-like three quark flavor models

abstract:
  We are computing the modifications for the scalar and pseudoscalar meson
masses and mixing angles due to the proper accounting of fermionic vacuum
fluctuation in the framework of the generalized 2+1 flavor quark meson model
and the Polyakov loop augmented quark meson model(PQM). The renormalized
contribution of the divergent fermionic vacuum fluctuation at one loop level
makes these models effective QCD-like models. It has been explicitly shown that
analytical expressions for the model parameters, meson masses, and mixing
angles do not depend on any arbitrary renormalization scale. We have
investigated how the incorporation of fermionic vacuum fluctuation in quark
meson and PQM models qualitatively and quantitatively affects the convergence
in the masses of the chiral partners in pseudoscalar ($\pi$, $\eta$, $\eta'$,
$K$) and scalar ($\sigma$, $a_0$, $f_0$, $\kappa$) meson nonets as the
temperature is varied on the reduced temperature scale. Comparison of present
results in the quark meson model with vacuum term and PQM model with vacuum
term with the already existing calculations in the bare 2+1 quark meson and PQM
models, shows that the restoration of chiral symmetry becomes smoother due to
the influence of the fermionic vacuum term. We find that the melting of the
strange condensate registers a significant increase in the presence of the
fermionic vacuum term and its highest melting is found in the PQM model with
vacuum term. The role of the $U_A(1)$ anomaly in determining the isoscalar
masses and mixing angles for the pseudoscalar ($\eta$ and $\eta'$) and scalar
($\sigma$ and $f_0$) meson complex has also been significantly modified due to
the fermionic vacuum correction. In its influence, the interplay of chiral
symmetry restoration and the setting up of the $U_A(1)$ restoration trends have
also been shown to be significantly modified.


title: Empirical estimates suggest most published medical research is true

abstract:
  The accuracy of published medical research is critical both for scientists,
physicians and patients who rely on these results. But the fundamental belief
in the medical literature was called into serious question by a paper
suggesting most published medical research is false. Here we adapt estimation
methods from the genomics community to the problem of estimating the rate of
false positives in the medical literature using reported P-values as the data.
We then collect P-values from the abstracts of all 77,430 papers published in
The Lancet, The Journal of the American Medical Association, The New England
Journal of Medicine, The British Medical Journal, and The American Journal of
Epidemiology between 2000 and 2010. We estimate that the overall rate of false
positives among reported results is 14% (s.d. 1%), contrary to previous claims.
We also find there is not a significant increase in the estimated rate of
reported false positive results over time (0.5% more FP per year, P = 0.18) or
with respect to journal submissions (0.1% more FP per 100 submissions, P =
0.48). Statistical analysis must allow for false positives in order to make
claims on the basis of noisy data. But our analysis suggests that the medical
literature remains a reliable record of scientific progress.


title:
Point-contact spectroscopy in Co-doped CaFe2As2: nodal superconductivity
  and topological Fermi surface transition

abstract:
  We performed point-contact Andreev reflection spectroscopy measurements in
Ca(Fe_{1-x}Co_x)2As2 single crystals with effective x=0.060 +- 0.005. The
spectra of ab-plane contacts show a zero-bias maximum and broad shoulders at
about 5-6 meV. Their fit with the three-dimensional Blonder-Tinkham-Klapwijk
model (making use of a analytical expression for the Fermi surface that mimics
the one calculated from first principles) shows that this compound presents a
large isotropic gap on the quasi-2D electronlike Fermi surface sheets and a
smaller anisotropic (possibly nodal) gap on the 3D holelike Fermi surface
pockets centered at the Z point in the Brillouin zone. These results nicely fit
into the theoretical picture for the appearance of nodal superconductivity in
122 compounds.


title: The IBMAP approach for Markov networks structure learning

abstract:
  In this work we consider the problem of learning the structure of Markov
networks from data. We present an approach for tackling this problem called
IBMAP, together with an efficient instantiation of the approach: the IBMAP-HC
algorithm, designed for avoiding important limitations of existing
independence-based algorithms. These algorithms proceed by performing
statistical independence tests on data, trusting completely the outcome of each
test. In practice tests may be incorrect, resulting in potential cascading
errors and the consequent reduction in the quality of the structures learned.
IBMAP contemplates this uncertainty in the outcome of the tests through a
probabilistic maximum-a-posteriori approach. The approach is instantiated in
the IBMAP-HC algorithm, a structure selection strategy that performs a
polynomial heuristic local search in the space of possible structures. We
present an extensive empirical evaluation on synthetic and real data, showing
that our algorithm outperforms significantly the current independence-based
algorithms, in terms of data efficiency and quality of learned structures, with
equivalent computational complexities. We also show the performance of IBMAP-HC
in a real-world application of knowledge discovery: EDAs, which are
evolutionary algorithms that use structure learning on each generation for
modeling the distribution of populations. The experiments show that when
IBMAP-HC is used to learn the structure, EDAs improve the convergence to the
optimum.


title:
The Correlation Between H\alpha\ Emission and Visual Magnitude During
  Long-Term Variations in Classical Be Stars

abstract:
  H\alpha\ equivalent widths and UBV magnitudes are calculated for Be star disk
models that grow in size and/or density with time. We show that these simple
models are consistent with the known Be star classes of positive and inverse
correlations between long-term variations in H\alpha\ and V magnitude as
identified by Harmanec. We support the conclusion of Harmanec that the
distinction is controlled by the inclination of the disk to the line of sight.
We demonstrate that the strength of these correlations, particularly those of
an inverse correlation where the system becomes fainter as the H\alpha\
emission strength grows, is strongly influenced by the scale height of the
inner Be star disk and the extent of the gravitational darkening of the central
B star due to rapid rotation. This dependence may allow coordinated
spectroscopic and photometric observations to better constrain these poorly
known Be star parameters.


title: On Matrix Geometry and Effective Actions

abstract:
  We provide an elementary systematic discussion of single-trace matrix actions
and of the group of matrix reparameterization that acts on them. The action of
this group yields a generalized notion of gauge invariance which encompasses
ordinary diffeomorphism and gauge invariances. We apply the formalism to
non-abelian D-brane actions in arbitrary supergravity backgrounds, providing in
particular explicit checks of the consistency of Myers' formulas with
supergravity gauge invariances. We also draw interesting consequences for
emergent space models based on the study of matrix effective actions. For
example, in the case of the AdS_5XS^5 background, we explain how the standard
tensor transformation laws of the supergravity fields under ordinary
diffeomorphisms emerge from the D-instanton effective action in this
background.


title: Stability of MaxWeight-({\alpha},g)

abstract:
  We consider a single-hop switched queueing network. Amongst a plethora of
applications, these networks have been used to model wireless networks and
input queued switches. The MaxWeight scheduling policies have proved popular,
chiefly, because they are throughput optimal and do not require explicit
estimation of arrival rates.
  In this article, we prove the same throughput optimality property for a
generalization of the MaxWeight policy called the MaxWeight-({\alpha},g)
policy. These throughput optimal, myopic scheduling policies allow for
scheduling choices similar to those found in bandwidth sharing networks -- a
further well studied model of Internet congestion.


title: High energy emission from transients

abstract:
  Cosmic explosions dissipate energy into their surroundings on a very wide
range of time-scales: producing shock waves and associated particle
acceleration. The historical culprits for the acceleration of the bulk of
Galactic cosmic rays are supernova remnants: explosions on ~10000 year
time-scales. Increasingly however, time-variable emission points to rapid and
efficient particle acceleration in a range of different astrophysical systems.
Gamma-ray bursts have the shortest time-scales, with inferred bulk Lorentz
factors of ~1000 and photons emitted beyond 100 GeV, but active galaxies,
pulsar wind nebulae and colliding stellar winds are all now associated with
time-variable emission at ~TeV energies. Cosmic photons and neutrinos at these
energies offer a powerful probe of the underlying physical mechanisms of cosmic
explosions, and a tool for exploring fundamental physics with these systems.
Here we discuss the motivations for high-energy observations of transients, the
current experimental situation, and the prospects for the next decade, with
particular reference to the major next-generation high-energy observatory CTA.


title: Nonlocality and fluctuations near the optical analog of a sonic horizon

abstract:
  We consider the behavior of fluctuations near the sonic horizon and the role
of the nonlocality of interaction (nonlinearity) on their regularization. The
nonlocality dominates if its characteristic length scale is larger than the
regularization length. The influence of nonlocality may be important in the
current experiments on the transonic flow in Kerr nonlinear media. Experimental
conditions, under which the observation of straddled fluctuations can be
observed, are discussed.


title:
Tradeoffs for number-squeezing in collisions of Bose-Einstein
  condensates

abstract:
  We investigate the factors that influence the usefulness of supersonic
collisions of Bose-Einstein condensates as a potential source of entangled
atomic pairs by analyzing the reduction of the number difference fluctuations
between regions of opposite momenta. We show that non-monochromaticity of the
mother clouds is typically the leading limitation on number squeezing, and that
the squeezing becomes less robust to this effect as the density of pairs grows.
We develop a simple model that explains the relationship between density
correlations and the number squeezing, allows one to estimate the squeezing
from properties of the correlation peaks, and shows how the multi-mode nature
of the scattering must be taken into account to understand the behavior of the
pairing. We analyze the impact of the Bose enhancement on the number squeezing,
by introducing a simplified low-gain model. We conclude that as far as
squeezing is concerned the preferable configuration occurs when atoms are
scattered not uniformly but rather into two well separated regions.


title: Optimal simulation of three-qubit gates

abstract:
  In this paper, we study the optimal simulation of three-qubit unitary by
using two-qubit gates. First, we give a lower bound on the two-qubit gates cost
of simulating a multi-qubit gate. Secondly, we completely characterize the
two-qubit gate cost of simulating a three-qubit controlled controlled gate by
generalizing our result on the cost of Toffoli gate. The function of controlled
controlled gate is simply a three-qubit controlled unitary gate and can be
intuitively explained as follows: the gate will output the states of the two
control qubit directly, and apply the given one-qubit unitary $u$ on the target
qubit only if both the states of the control are $\ket{1}$. Previously, it is
only known that five two-qubit gates is sufficient for implementing such a gate
[Sleator and Weinfurter, Phys. Rev. Lett. 74, 4087 (1995)]. Our result shows
that if the determinant of $u$ is 1, four two-qubit gates is achievable
optimal. Otherwise, five is optimal. Thirdly, we show that five two-qubit gates
are necessary and sufficient for implementing the Fredkin gate(the controlled
swap gate), which settles the open problem introduced in [Smolin and
DiVincenzo, Phys. Rev. A, 53, 2855 (1996)]. The Fredkin gate is one of the most
important quantum logic gates because it is universal alone for classical
reversible computation, and thus with little help, universal for quantum
computation. Before our work, a five two-qubit gates decomposition of the
Fredkin gate was already known, and numerical evidence of showing five is
optimal is found.


title: Holographic superconductor models with $RF^{2}$ corrections

abstract:
  We investigate the effect of the $RF^2$ correction on the holographic
superconductor model in the background of AdS black hole. We find that, similar
to the effect caused by the Weyl correction, the higher $RF^2$ correction term
can make it easier for the scalar operator to condense and result in the larger
deviations from the expected relation in the gap frequency. However, if a
non-trivial hair for the black hole has been triggered, we observe that the
$RF^2$ correction and the Weyl correction do play different roles in the
behavior of the condensation, which can be used to support the existing
findings.


title: Generalized even and odd totally positive matrices

abstract:
  A generalization of the definition of an oscillatory matrix based on the
theory of cones is given in this paper. The positivity and simplicity of all
the eigenvalues of a generalized oscillatory matrix are proved. The classes of
generalized even and odd oscillatory matrices are introduced. Spectral
properties of the obtained matrices are studied. Criteria of generalized even
and odd oscillation are given. Examples of generalized even and odd oscillatory
matrices are presented.


title: The discovery of an anomalous RGB in M 2

abstract:
  Using UV images taken with the Telescopio Nazionale Galileo, we discovered an
anomalous sequence in the color-magnitude diagram of M 2. This feature appears
as a narrow poor-populated red giant branch, which extends down to the sub
giant branch region. We speculate that this new feature could be the extension
of the faint component of the split sub giant branch recently discovered by
Piotto et al. We identified in our UV images two CH stars detected in previous
studies. These stars, which are both cluster members, fall on this redder
sequence, suggesting indeed that the anomalous RGB should have a peculiar
chemical pattern. Unfortunately, no additional spectra were obtained for stars
in this previously unknown substructure


title: Cone-theoretic generalization of total positivity

abstract:
  This paper is devoted to the generalization of the theory of total
positivity. We say that a linear operator A in R^n is generalized totally
positive (GTP), if its jth exterior power preserves a proper cone K_j in the
corresponding space for every j = 1, ..., n. We also define generalized
strictly totally positive (GSTP) operators. We prove that the spectrum of a
GSTP operator is positive and simple, moreover, its eigenvectors are localized
in special sets. The existence of invariant cones of finite ranks is shown
under some additional conditions. Some new insights and alternative proofs of
the well-known results of Gantmacher and Krein describing the properties of TP
and STP matrices are presented.


title: Dust Properties in the Galactic Bulge

abstract:
  It has been suggested that the ratio of total-to-selective extinction RV in
dust in the interstellar medium differs in the Galactic bulge from its value in
the local neighborhood. We attempt to test this suggestion. The mid-infrared
hydrogen lines in 16 Galactic bulge PNe measured by the Spitzer Space Telescope
are used to determine the extinction corrected H{\beta} flux. This is compared
to the observed H{\beta} flux to obtain the total extinction at H{\beta}. The
selective extinction is obtained from the observed Balmer decrement in these
nebulae. The value of RV can then be found. The ratio of total-to-selective
extinction in the Galactic bulge is consistent with the value RV =3.1, which is
the same as has been found in the local neighborhood. We conclude that the
suggestion that RV is different in the Galactic bulge is incorrect. The reasons
for this are discussed.


title: Homology classes of negative square and embedded surfaces in 4-manifolds

abstract:
  Let X be a simply-connected closed oriented 4-manifold and A an embedded
surface of genus g and negative self-intersection -N. We show that for fixed
genus g there is an upper bound on N if the homology class of A is divisible or
characteristic. In particular, for genus zero, there is a lower bound on the
self-intersection of embedded spheres in these kinds of homology classes. This
question is related to a problem from the Kirby list.


title:
Generalized Brouncker's continued fractions and their logarithmic
  derivatives

abstract:
  In this paper, we study the continued fraction y(s,r) which satisfies the
equation y(s,r)y(s+2r,r)=(s+1)(s+2r-1) for r > 1/2. This continued fraction is
a generalization of the Brouncker's continued fraction b(s). We extend the
formulas for the first and the second logarithmic derivatives of b(s) to the
case of y(s,r). The asymptotic series for y(s,r) at the infinity are also
studied. The generalizations of some Ramanujan's formulas are presented.


title: Topological pumping in the one-dimensional Bose-Hubbard model

abstract:
  By means of time-dependent density matrix renormalization group calculations
we study topological quantum pumping in a strongly interacting system. The
system under consideration is described by the Hamiltonian of a one-dimensional
extended Bose-Hubbard model in the presence of a correlated hopping which
breaks lattice inversion symmetry. This model has been predicted to support
topological pumping [E. Berg, M. Levin, and E. Altman, Phys. Rev. Lett. 106,
110405 (2011)]. The pumped charge is quantized and of topological nature. We
provide a detailed analysis of the finite-size-scaling behavior of the pumped
charge and its deviations from the quantized value. Furthermore we also analyze
the non-adiabatic corrections due to the finite frequency of the modulation. We
consider two configurations: a closed ring where the time-dependence of the
parameter induces a circulating current, and a finite open-ended chain where
particles are dragged from one edge to the opposite edge, due to the pumping
mechanism induced by the bulk.


title:
Enhanced Spin and Electronic Reconstructions at the Cuprate-Manganite
  Interface

abstract:
  We report on a resonant soft X-ray spectroscopy study of the electronic and
magnetic structure of the cuprate-manganite interface. Polarized X-ray
spectroscopy measurements taken at the Cu L edge reveal up to a five-fold
increase in the dichroic signal as compared to past experimental and
theoretical values. Furthermore an increase in the degree of interlayer charge
transfer up to 0.25e (where e is charge of an electron) per copper ion is
observed leading to a profound reconstruction in the orbital scheme for these
interfacial copper ions. It is inferred that these enhancement are related to
an increase in TMI observed for manganite layers grown with rapidly modulated
flux.


title:
Rare baryon decays Lambda_b -> Lambda l+ l- (l=e, mu, tau) and Lambda_b
  -> Lambda gamma : Differential and total rates, lepton- and hadron-side
  forward-backward asymmetries

abstract:
  Using the covariant constituent quark model previously developed by us we
calculate the differential rate and the forward-backward asymmetries on the
lepton and hadron side for the rare baryon decays Lambda_b -> Lambda l+ l-
(l=e, mu, tau) and Lambda_b -> Lambda gamma. We use helicity methods to write
down a three-fold joint angular decay distribution for the cascade decay
Lambda_b -> Lambda (-> p pi-) + J_eff (-> l+ l-). Through appropriate angular
integrations we obtain expressions for the rates, the lepton-side
forward-backward (FB) asymmetry and the polarization of the daughter baryon
Lambda leading to a hadron-side forward-backward asymmetry. We present
numerical results on these observables using the covariant quark model and
compare our results to the results of other calculations that have appeared in
the literature.


title: Examples of Emergent Type IIB Backgrounds from Matrices

abstract:
  We study models of emergent space associated with the Coulomb branch,
non-commutative and beta deformations of the N=4 super Yang-Mills theory,
extending a previous work on the undeformed conformal case. The idea is to
compute the effective action for D-instantons from the microscopic
four-dimensional open-string description and to compare with the non-abelian
D-instanton action in the dual ten-dimensional supergravity background. To
linear order in the deformation parameter, the D-instantons can probe the full
space-time geometry and we can derive all the supergravity fields in this way.
We find a perfect match with the known supergravity solutions, including for
the Neveu-Schwarz and Ramond-Ramond forms.


title:
The Radio-X-ray Connection in Young Stellar Objects in the Orion Nebula
  Cluster

abstract:
  (Abridged) Context: Both X-ray and radio observations offer insight into the
high-energy processes of young stellar objects (YSOs). The observed thermal
X-ray emission can be accompanied by both thermal and nonthermal radio
emission. Due to variability, simultaneous X-ray and radio observations are a
priori required, but results have been inconclusive. Aims: We use archival
X-ray and radio observations of the Orion Nebula Cluster (ONC) to significantly
enlarge the sample size of known YSOs with both X-ray and radio detections.
Methods: We study the ONC using multi-epoch non-simultaneous archival Chandra
X-ray and NRAO Very Large Array (VLA) single-band radio data. The multiple
epochs allow us to reduce the impact of variability by obtaining approximated
quiescent fluxes. Results: We find that only a small fraction of the X-ray
sources (7%) have radio counterparts, even if 60% of the radio sources have
X-ray counterparts. The radio flux density is typically too low to distinguish
thermal and nonthermal radio sources. Only a small fraction of the YSOs with
detections in both bands are compatible with the empirical "Guedel-Benz" (GB)
relation. Most of the sources not compatible with the GB relation are proplyds,
and thus likely thermal sources, but only a fraction of the proplyds is
detected in both bands, such that the role of these sources is inconclusive.
Conclusions: While the radio sources appear to be globally unrelated to the
X-ray sources, the X-ray dataset clearly is much more sensitive than the radio
data. We find tentative evidence that known non-thermal radio sources and
saturated X-ray sources are indeed close to the empirical relation, even if
skewed to higher radio luminosities, as they are expected to be. Most of the
sources that are clearly incompatible with the empirical relation are proplyds
which could instead plausibly be thermal radio sources.


title: IPN localizations of Konus short gamma-ray bursts

abstract:
  Between the launch of the \textit{GGS Wind} spacecraft in 1994 November and
the end of 2010, the Konus-\textit{Wind} experiment detected 296 short-duration
gamma-ray bursts (including 23 bursts which can be classified as short bursts
with extended emission). During this period, the IPN consisted of up to eleven
spacecraft, and using triangulation, the localizations of 271 bursts were
obtained. We present the most comprehensive IPN localization data on these
events. The short burst detection rate, $\sim$18 per year, exceeds that of many
individual experiments.


title:
A stabilized finite element method for advection-diffusion equations on
  surfaces

abstract:
  A recently developed Eulerian finite element method is applied to solve
advection-diffusion equations posed on hypersurfaces. When transport processes
on a surface dominate over diffusion, finite element methods tend to be
unstable unless the mesh is sufficiently fine. The paper introduces a
stabilized finite element formulation based on the SUPG technique. An error
analysis of the method is given. Results of numerical experiments are presented
that illustrate the performance of the stabilized method.


title:
Response of the Jovian thermosphere to a transient `pulse' in solar wind
  pressure

abstract:
  The importance of the Jovian thermosphere with regard to
magnetosphere-ionosphere coupling is often neglected in magnetospheric physics.
We present the first study to investigate the response of the Jovian
thermosphere to transient variations in solar wind dynamic pressure, using an
azimuthally symmetric global circulation model coupled to a simple
magnetosphere and fixed auroral conductivity model. In our simulations, the
Jovian magnetosphere encounters a solar wind shock or rarefaction region and is
subsequently compressed or expanded. We present the ensuing response of the
coupling currents, thermospheric flows, heating and cooling terms, and the
aurora to these transient events. Transient compressions cause the reversal,
with respect to steady state, of magnetosphere-ionosphere coupling currents and
momentum transfer between the thermosphere and magnetosphere. They also cause
at least a factor of two increase in the Joule heating rate. Ion drag
significantly changes the kinetic energy of the thermospheric neutrals
depending on whether the magnetosphere is compressed or expanded. Local
temperature variations appear between ~ -45 and 175 K for the compression
scenario and ~ -20 and 50 K for the expansion case. Extended regions of
equatorward flow develop in the wake of compression events - we discuss the
implications of this behaviour for global energy transport. Both compressions
and expansions lead to a ~ 2000 TW increase in the total power dissipated or
deposited in the thermosphere. In terms of auroral processes, transient
compressions increase main oval UV emission by a factor of 4.5 whilst transient
expansions increase this main emission by a more modest 37%. Both types of
transient event cause shifts in the position of the main oval, of up to 1 deg
latitude.


title: Effect of transient solar wind pulses on atmospheric heating at Jupiter

abstract:
  Previously, we have presented the first study to investigate the response of
the Jovian thermosphere to transient variations in solar wind dynamic pressure,
using a coupled, azimuthally symmetric global circulation model coupled with a
simple magnetosphere model. This work (Yates et al., 2013, submitted) described
the response of thermospheric flows, momentum sources, and the
magnetosphere-ionosphere coupling currents to transient compressions and
expansions in the magnetosphere. The present study describes the response of
thermospheric heating, cooling and the auroral emissions to the aforementioned
transient events. We find that transient compressions and expansions, on time
scales <= 3 hours, cause at least a factor of two increase in Joule heating per
unit volume. Ion drag significantly changes the kinetic energy of the
thermospheric neutrals depending on whether the magnetosphere is compressed or
expanded. These processes lead to local temperature variations >= 25 K and a
~2000 TW increase in the total power dissipated in the thermosphere. In terms
of auroral processes, transient compressions increase main oval UV emission by
a factor of ~4.5 whilst transient expansions increase this main emission by a
more modest 37%. Both types of transient event cause shifts in the position of
the main oval, of up to 1 deg latitude.


title: Mandated data archiving greatly improves access to research data

abstract:
  The data underlying scientific papers should be accessible to researchers
both now and in the future, but how best can we ensure that these data are
available? Here we examine the effectiveness of four approaches to data
archiving: no stated archiving policy, recommending (but not requiring)
archiving, and two versions of mandating data deposition at acceptance. We
control for differences between data types by trying to obtain data from papers
that use a single, widespread population genetic analysis, STRUCTURE. At one
extreme, we found that mandated data archiving policies that require the
inclusion of a data availability statement in the manuscript improve the odds
of finding the data online almost a thousand-fold compared to having no policy.
However, archiving rates at journals with less stringent policies were only
very slightly higher than those with no policy at all. At one extreme, we found
that mandated data archiving policies that require the inclusion of a data
availability statement in the manuscript improve the odds of finding the data
online almost a thousand fold compared to having no policy. However, archiving
rates at journals with less stringent policies were only very slightly higher
than those with no policy at all. We also assessed the effectiveness of asking
for data directly from authors and obtained over half of the requested
datasets, albeit with about 8 days delay and some disagreement with authors.
Given the long term benefits of data accessibility to the academic community,
we believe that journal based mandatory data archiving policies and mandatory
data availability statements should be more widely adopted.


title: On surface meshes induced by level set functions

abstract:
  The zero level set of a piecewise-affine function with respect to a
consistent tetrahedral subdivision of a domain in $\mathbb{R}^3$ is a
piecewise-planar hyper-surface. We prove that if a family of consistent
tetrahedral subdivions satisfies the minimum angle condition, then after a
simple postprocessing this zero level set becomes a consistent surface
triangulation which satisfies the maximum angle condition. We treat an
application of this result to the numerical solution of PDEs posed on surfaces,
using a $P_1$ finite element space on such a surface triangulation. For this
finite element space we derive optimal interpolation error bounds. We prove
that the diagonally scaled mass matrix is well-conditioned, uniformly with
respect to $h$. Furthermore, the issue of conditioning of the stiffness matrix
is addressed.


title: A core-free semicovering of the Hawaiian Earring

abstract:
  The connected covering spaces of a connected and locally path-connected
topological space $X$ can be classified by the conjugacy classes of those
subgroups of $\pi_1(X,x)$ which contain an open normal subgroup of
$\pi_1(X,x)$, when endowed with the natural quotient topology of the
compact-open topology on based loops. There are known examples of semicoverings
(in the sense of Brazas) that correspond to open subgroups which do not contain
an open normal subgroup. We present an example of a semicovering of the
Hawaiian Earring $\mathds{H}$ with corresponding open subgroup of
$\pi_1(\mathds{H})$ which does not contain {\em any} nontrivial normal subgroup
of $\pi_1(\mathds{H})$.


title: Generalized parity in multi-photon Rabi model

abstract:
  Quantum multi--photon spin--boson model is considered. We solve an operator
Riccati equation associated with that model and present a candidate for a
generalized parity operator allowing to transform spin--boson Hamiltonian to a
block diagonal form what indicates an existence of the related symmetry of the
model.


title: Deep Impact: Unintended consequences of journal rank

abstract:
  Most researchers acknowledge an intrinsic hierarchy in the scholarly journals
('journal rank') that they submit their work to, and adjust not only their
submission but also their reading strategies accordingly. On the other hand,
much has been written about the negative effects of institutionalizing journal
rank as an impact measure. So far, contributions to the debate concerning the
limitations of journal rank as a scientific impact assessment tool have either
lacked data, or relied on only a few studies. In this review, we present the
most recent and pertinent data on the consequences of our current scholarly
communication system with respect to various measures of scientific quality
(such as utility/citations, methodological soundness, expert ratings or
retractions). These data corroborate previous hypotheses: using journal rank as
an assessment tool is bad scientific practice. Moreover, the data lead us to
argue that any journal rank (not only the currently-favored Impact Factor)
would have this negative impact. Therefore, we suggest that abandoning journals
altogether, in favor of a library-based scholarly communication system, will
ultimately be necessary. This new system will use modern information technology
to vastly improve the filter, sort and discovery functions of the current
journal system.


title:
The existence of a bending rigidity for a hard sphere liquid near a
  curved hard wall: Helfrich or Hadwiger?

abstract:
  In the context of Rosenfeld's Fundamental Measure Theory, we show that the
bending rigidity is not equal to zero for a hard-sphere fluid in contact with a
curved hard wall. The implication is that the Hadwiger Theorem does not hold in
this case and the surface free energy is given by the Helfrich expansion
instead. The value obtained for the bending rigidity is (1) an order of
magnitude smaller than the bending constant associated with Gaussian curvature,
(2) changes sign as a function of the fluid volume fraction, (3) is independent
of the choice for the location of the hard wall.


title:
Neutron and proton tests of different technologies for the upgrade of
  the cold readout electronics of the ATLAS Hadronic End-cap Calorimeter

abstract:
  The expected increase of total integrated luminosity by a factor ten at the
HL-LHC compared to the design goals for LHC essentially eliminates the safety
factor for radiation hardness realized at the current cold amplifiers of the
ATLAS Hadronic End-cap Calorimeter (HEC). New more radiation hard technologies
have been studied: SiGe bipolar, Si CMOS FET and GaAs FET transistors have been
irradiated with neutrons up to an integrated fluence of 2.2 x 10^{16} n/cm^2
and with 200 MeV protons up to an integrated fluence of 2.6 x 10^{14} p/cm^2.
Comparisons of transistor parameters such as the gain for both types of
irradiations are presented.


title: On the transition reduction problem for finite automata

abstract:
  We are interested in the problem of transition reduction of nondeterministic
automata. We present some results on the reduction of the automata recognizing
the language $L(E_n)$ denoted by the regular expression $E_n=(1+\varepsilon)...
(2+\varepsilon)... (3+\varepsilon)... (n+\varepsilon)$. These results can be
used in the general case of the transition reduction problem.


title:
Conformal deformations of immersed discs in $R^3$ and elliptic boundary
  value problems

abstract:
  Boundary value problems for operators of Dirac type arise naturally in
connection with the conformal geometry of surfaces immersed in Euclidean
3--space. Recently such boundary value problems have been successfully applied
to a variety of problems from computer graphics. Here we investigate under
which conditions these boundary value problems are elliptic and self--adjoint.
We show that under certain periodic deformations of the boundary data our
operators exhibit non-trivial spectral flow.


title: Switched linear encoding with rectified linear autoencoders

abstract:
  Several recent results in machine learning have established formal
connections between autoencoders---artificial neural network models that
attempt to reproduce their inputs---and other coding models like sparse coding
and K-means. This paper explores in depth an autoencoder model that is
constructed using rectified linear activations on its hidden units. Our
analysis builds on recent results to further unify the world of sparse linear
coding models. We provide an intuitive interpretation of the behavior of these
coding models and demonstrate this intuition using small, artificial datasets
with known distributions.


title: The Case for a Solar Influence on Certain Nuclear Decay Rates

abstract:
  Power-spectrum analyses of the decay rates of certain nuclides reveal (at
very high confidence levels) an annual oscillation and periodicities that may
be attributed to solar rotation and to solar r-mode oscillations. A comparison
of spectrograms (time-frequency displays) formed from decay data and from solar
neutrino data reveals a common periodicity with frequency 12.5 year-1, which is
indicative of the solar radiative zone. We propose that the neutrino flux is
modulated by the solar magnetic field (via Resonant Spin Flavor Precession) in
that region, and we estimate the force and the torque that could be exerted on
a nuclide by the solar neutrino flux.


title:
Gradient Driven Learning for Pooling in Visual Pipeline Feature
  Extraction Models

abstract:
  Hyper-parameter selection remains a daunting task when building a pattern
recognition architecture which performs well, particularly in recently
constructed visual pipeline models for feature extraction. We re-formulate
pooling in an existing pipeline as a function of adjustable pooling map weight
parameters and propose the use of supervised error signals from gradient
descent to tune the established maps within the model. This technique allows us
to learn what would otherwise be a design choice within the model and
specialize the maps to aggregate areas of invariance for the task presented.
Preliminary results show moderate potential gains in classification accuracy
and highlight areas of importance within the intermediate feature
representation space.


title:
Charge correlations using the balance function in Pb-Pb collisions at
  $\sqrt{s_{\rm NN}} = 2.76$ TeV

abstract:
  In high-energy heavy-ion collisions, the correlations between the emitted
particles can be used as a probe to gain insight into the charge creation
mechanisms. In this Letter, we report the first results of such studies using
the electric charge balance function in the relative pseudorapidity
($\Delta\eta$) and azimuthal angle ($\Delta\varphi$) in Pb--Pb collisions at
$\sqrt{s_{\rm NN}}=2.76$ TeV with the ALICE detector at the Large Hadron
Collider. The width of the balance function decreases with growing centrality
(i.e. for more central collisions) in both projections. This centrality
dependence is not reproduced by HIJING, while AMPT, a model which incorporates
strings and parton rescattering, exhibits qualitative agreement with the
measured correlations in $\Delta\varphi$ but fails to describe the correlations
in $\Delta\eta$. A thermal blast-wave model incorporating local charge
conservation and tuned to describe the $p_{\rm T}$ spectra and v$_2$
measurements reported by ALICE, is used to fit the centrality dependence of the
width of the balance function and to extract the average separation of
balancing charges at freeze-out. The comparison of our results with
measurements at lower energies reveals an ordering with $\sqrt{s_{\rm NN}}$:
the balance functions become narrower with increasing energy for all
centralities. This is consistent with the effect of larger radial flow at the
LHC energies but also with the late stage creation scenario of balancing
charges. However, the relative decrease of the balance function widths in
$\Delta\eta$ and $\Delta\varphi$ with centrality from the highest SPS to the
LHC energy exhibits only small differences. This observation cannot be
interpreted solely within the framework where the majority of the charge is
produced at a later stage in the evolution of the heavy--ion collision.


title:
Effects of isoelectronic Ru substitution at the Fe site on the energy
  gaps of optimally F-doped SmFeAsO

abstract:
  We studied the effects of isoelectronic Ru substitution at the Fe site on the
energy gaps of optimally F-doped SmFeAsO by means of point-contact Andreev
reflection spectroscopy. The results show that the
SmFe_{1-x}Ru_{x}AsO_{0.85}F_{0.15} system keeps a multigap character at least
up to x=0.50, and that the gap amplitudes Delta_1 and Delta_2 scale almost
linearly with the local critical temperature TcA. The gap ratios 2Delta_i/(kB
Tc) remain approximately constant only as long as Tc > 30 K, but increase
dramatically when Tc decreases further. This trend seems to be common to many
Fe-based superconductors, irrespective of their family. Based on
first-principle calculations of the bandstructure and of the density of states
projected on the different bands, we show that this trend, as well as the Tc
dependence of the gaps and the reduction of Tc upon Ru doping, can be explained
within an effective three-band Eliashberg model as being due to a suppression
of the superfluid density at finite temperature that, in turns, modifies the
temperature dependence of the characteristic spin-fluctuation energy.


title:
Mutual Localization: Two Camera Relative 6-DOF Pose Estimation from
  Reciprocal Fiducial Observation

abstract:
  Concurrently estimating the 6-DOF pose of multiple cameras or
robots---cooperative localization---is a core problem in contemporary robotics.
Current works focus on a set of mutually observable world landmarks and often
require inbuilt egomotion estimates; situations in which both assumptions are
violated often arise, for example, robots with erroneous low quality odometry
and IMU exploring an unknown environment. In contrast to these existing works
in cooperative localization, we propose a cooperative localization method,
which we call mutual localization, that uses reciprocal observations of
camera-fiducials to obviate the need for egomotion estimates and mutually
observable world landmarks. We formulate and solve an algebraic formulation for
the pose of the two camera mutual localization setup under these assumptions.
Our experiments demonstrate the capabilities of our proposal egomotion-free
cooperative localization method: for example, the method achieves 2cm range and
0.7 degree accuracy at 2m sensing for 6-DOF pose. To demonstrate the
applicability of the proposed work, we deploy our method on Turtlebots and we
compare our results with ARToolKit and Bundler, over which our method achieves
a 10 fold improvement in translation estimation accuracy.


title: Joint Modelling of Multiple Network Views

abstract:
  Latent space models (LSM) for network data were introduced by Hoff et al.
(2002) under the basic assumption that each node of the network has an unknown
position in a D-dimensional Euclidean latent space: generally the smaller the
distance between two nodes in the latent space, the greater their probability
of being connected. In this paper we propose a variational Bayes approach to
estimate the intractable posterior of the LSM.
  In many cases, different network views on the same set of nodes are
available. It can therefore be useful to build a model able to jointly
summarise the information given by all the network views. For this purpose, we
introduce the latent space joint model (LSJM) that merges the information given
by multiple network views assuming that the probability of a node being
connected with other nodes in each network view is explained by a unique latent
variable. This model is demonstrated on the analysis of two datasets: the
excerpt of 50 girls from `Teenage Friends and Lifestyle Study' data at three
time points and the Saccharomyces cerevisiae genetic and physical
protein-protein interactions.


title: Transit timing variations in WASP-10b induced by stellar activity?

abstract:
  The hot-Jupiter WASP-10b was reported by Maciejewski et al. (2011a,b) to show
transit timing variations (TTV) with an amplitude of ~ 3.5 minutes. These
authors proposed that the observed TTVs were caused by a 0.1 MJup perturbing
companion with an orbital period of ~ 5.23 d, and hence, close to the outer 5:3
mean motion resonance with WASP-10b. To test this scenario, we present eight
new transit light curves of WASP-10b obtained with the Faulkes Telescope North
and the Liverpool Telescope. The new light curves, together with 22 previously
published ones, were modelled with a Markov-Chain Monte-Carlo transit fitting
code. (...)
  Our homogeneously derived transit times do not support the previous claimed
TTV signal, which was strongly dependent on 2 previously published transits
that have been incorrectly normalised. Nevertheless, a linear ephemeris is not
a statistically good fit to the transit times of WASP-10b. We show that the
observed transit time variations are due to spot occultation features or
systematics. We discuss and exemplify the effects of occultation spot features
in the measured transit times and show that despite spot occultation during
egress and ingress being difficult to distinguish in the transit light curves,
they have a significant effect in the measured transit times. We conclude that
if we account for spot features, the transit times of WASP-10 are consistent
with a linear ephemeris with the exception of one transit (epoch 143) which is
a partial transit. Therefore, there is currently no evidence for the existence
of a companion to WASP-10b. Our results support the lack of TTVs of
hot-Jupiters reported for the Kepler sample.


title:
A molecular dynamics and circular dichroism study of a novel synthetic
  antimicrobial peptide

abstract:
  Antimicrobial peptides are a class of small, usually positively charged
amphiphilic peptides that are used by the innate immune system to combat
bacterial infection in multicellular eukaryotes. Antimicrobial peptides are
known for their broad-spectrum antimicrobial activity and thus can be used as a
basis for a development of new antibiotics against multidrug-resistant
bacteria. The most challengeous task on the way to a therapeutic use of
antimicrobial peptides is a rational design of new peptides with enhanced
activity and reduced toxicity. Here we report a molecular dynamics and circular
dichroism study of a novel synthetic antimicrobial peptide D51. This peptide
was earlier designed by Loose et al. using a linguistic model of natural
antimicrobial peptides. Molecular dynamics simulation of the peptide folding in
explicit solvent shows fast formation of two antiparallel beta strands
connected by a beta-turn that is confirmed by circular dichroism measurements.
Obtained from simulation amphipatic conformation of the peptide is analysed and
possible mechanism of its interaction with bacterial membranes together with
ways to enhance its antibacterial activity are suggested.


title: Gain-tunable optomechanical cooling in a laser cavity

abstract:
  We study the optical cooling of the resonator mirror in a
cavity-optomechanical system that contains an optical gain medium. We find that
the optical damping rate is vanishingly small for an incoherently pumped laser
above threshold. In the presence of an external coherent drive however, the
optical damping rate can be enhanced substantially with respect to that of a
passive cavity. We show that the strength of the incoherent pump provides a
conduit to tune the damping rate and the minimum attainable phonon number with
the same radiation pressure force, and the latter can be lowered from that of a
passive cavity if the thermal contribution is nonnegligible. We also show that
the system can undergo a transition from the weak optomechanical coupling
regime to the strong optomechanical coupling regime as the incoherent pump
strength is varied.


title: Highly polarized Fermi gases in two dimensions

abstract:
  We investigate the highly polarized limit of a two-dimensional (2D) Fermi
gas, where we effectively have a single spin-down impurity atom immersed in a
spin-up Fermi sea. By constructing variational wave functions for the impurity,
we map out the ground state phase diagram as a function of mass ratio M/m and
interaction strength. In particular, we determine when it is favorable for the
dressed impurity (polaron) to bind particles from the Fermi sea to form a
dimer, trimer or even larger clusters. Similarly to 3D, we find that the Fermi
sea favors the trimer state so that it exists for M/m less than the critical
mass ratio for trimer formation in the vacuum. We also find a region where
dimers have finite momentum in the ground state, a scenario which corresponds
to the Fulde-Ferrell-Larkin-Ovchinnikov superfluid state in the limit of large
spin imbalance. For equal masses (M=m), we compute rigorous bounds on the
polaron-dimer transition, and we show that the polaron energy and residue is
well captured by the variational approach, with the former quantity being in
good agreement with experiment. When there is a finite density of impurities,
we find that this polaron-dimer transition is preempted by a first-order
superfluid-normal transition at zero temperature, but it remains an open
question what happens at finite temperature.


title:
Adaptive learning rates and parallelization for stochastic, sparse,
  non-smooth gradients

abstract:
  Recent work has established an empirically successful framework for adapting
learning rates for stochastic gradient descent (SGD). This effectively removes
all needs for tuning, while automatically reducing learning rates over time on
stationary problems, and permitting learning rates to grow appropriately in
non-stationary tasks. Here, we extend the idea in three directions, addressing
proper minibatch parallelization, including reweighted updates for sparse or
orthogonal gradients, improving robustness on non-smooth loss functions, in the
process replacing the diagonal Hessian estimation procedure that may not always
be available by a robust finite-difference approximation. The final algorithm
integrates all these components, has linear complexity and is hyper-parameter
free.


title:
On the Harnack inequality for parabolic minimizers in metric measure
  spaces

abstract:
  In this note we consider problems related to parabolic partial differential
equations in geodesic metric measure spaces, that are equipped with a doubling
measure and a Poincar\'e inequality. We prove a location and scale invariant
Harnack inequality for a minimizer of a variational problem related to a doubly
non-linear parabolic equation involving the p-Laplacian. Moreover, we prove the
sufficiency of the Grigor'yan--Saloff-Coste theorem for general p > 1 in
geodesic metric spaces. The approach used is strictly variational, and hence we
are able to carry out the argument in the metric setting.


title: Random directed forest and the Brownian web

abstract:
  Consider the $d$ dimensional lattice $\mathbb{Z}^d$ where each vertex is open
or closed with probability $p$ or $1-p$ respectively. An open vertex
$\mathbb{u} := (\mathbb{u}(1), \mathbb{u}(2),...,\mathbb{u}(d))$ is connected
by an edge to another open vertex which has the minimum $L_1$ distance among
all the open vertices with $\mathbb{x}(d)>\mathbb{u}(d)$. It is shown that this
random graph is a tree almost surely for $d=2$ and 3 and it is an infinite
collection of disjoint trees for $d\geq 4$. In addition for $d=2$, we show that
when properly scaled, family of its paths converges in distribution to the
Brownian web.


title: Lagrangian concordance is not a symmetric relation

abstract:
  We provide an explicit example of a non trivial Legendrian knot $\Lambda$
such that there exists a Lagrangian concordance from $\Lambda_0$ to $\Lambda$
where $\Lambda_0$ is the trivial Legendrian knot. We then use the map induced
in Legendrian contact homology by a concordance and the augmentation category
of $\Lambda$ to show that no Lagrangian concordance exists in the other
direction. This proves that the relation of Lagrangian concordance is not
symmetric.


title:
Mass/Radius Constraints on the Quiescent Neutron Star in M13 Using
  Hydrogen and Helium Atmospheres

abstract:
  The mass and radius of the neutron star (NS) in low-mass X-ray binaries can
be obtained by fitting the X-ray spectrum of the NS in quiescence, and the mass
and radius constrains the properties of dense matter in NS cores. A critical
ingredient for spectral fits is the composition of the NS atmosphere: hydrogen
atmospheres are assumed in most prior work, but helium atmospheres are possible
if the donor star is a helium white dwarf. Here we perform spectral fits to
XMM, Chandra, and ROSAT data of a quiescent NS in the globular cluster M13.
This NS has the smallest inferred radius from previous spectral fitting.
Assuming an atmosphere composed of hydrogen, we find a significantly larger
radius, more consistent with those from other quiescent NSs. With a helium
atmosphere (an equally acceptable fit), we find even larger values for the
radius.


title:
Huge field-effect surface charge injection and conductance modulation in
  metallic thin films by electrochemical gating

abstract:
  The field-effect technique, popular thanks to its application in common
field-effect transistors, is here applied to metallic thin films by using as a
dielectric a novel polymer electrolyte solution. The maximum injected surface
charge, determined by a suitable modification of a classic method of
electrochemistry called double-step chronocoulometry, reached some units in
10^15 charges/cm^2. At room temperature, relative variations of resistance up
to 8%, 1.9% and 1.6% were observed in the case of gold, silver and copper,
respectively and, if the films are thick enough (> 25 nm), results can be
nicely explained within a free-electron model with parallel resistive channels.
The huge charge injections achieved make this particular field-effect technique
very promising for a vast variety of materials such as unconventional
superconductors, graphene and 2D-like materials.


title: Negative refraction and spatial echo in optical waveguide arrays

abstract:
  The special symmetry properties of the discrete nonlinear Schrodinger
equation allow a complete revival of the initial wavefunction. That is employed
in the context of stationary propagation of light in a waveguide array. As an
inverting system we propose a short array of almost isolated waveguides which
cause a relative pi phase shift in the neighboring waveguides. By means of
numerical simulations of the model equations we demonstrate a novel mechanism
for the negative refraction of spatial solitons.


title: Combinatorial Optimization in Pattern Assembly

abstract:
  Pattern self-assembly tile set synthesis (PATS) is a combinatorial
optimization problem which aim at minimizing a rectilinear tile assembly system
(RTAS) that uniquely self-assembles a given rectangular pattern, and is known
to be NP-hard. PATS gets practically meaningful when it is parameterized by a
constant c such that any given pattern is guaranteed to contain at most c
colors (c-PATS). We first investigate simple patterns and properties of minimum
RTASs for them. Then based on them, we design a 59-colored pattern to which
3SAT is reduced, and prove that 59-PATS is NP-hard.


title: Numerical relativity in higher dimensions

abstract:
  We present an overview of recent developments in numerical relativity studies
of higher dimensional spacetimes with a focus on time evolutions of black-hole
systems. After a brief review of the numerical techniques employed for these
studies, we summarize results grouped into the following three areas: (i)
Numerical studies of fundamental properties of black holes, (ii) Applications
of black-hole collisions to the modeling of Trans-Planckian scattering, (iii)
Numerical studies of asymptotically anti-de Sitter spacetimes in the context of
the gauge-gravity duality.


title: SCUBA-2: on-sky calibration using submillimetre standard sources

abstract:
  SCUBA-2 is a 10000-bolometer submillimetre camera on the James Clerk Maxwell
Telescope (JCMT). The instrument commissioning was completed in September 2011,
and full science operations began in October 2011. To harness the full
potential of this powerful new astronomical tool, the instrument calibration
must be accurate and well understood. To this end, the algorithms for
calculating the line-of-sight opacity have been improved, and the derived
atmospheric extinction relationships at both wavebands of the SCUBA-2
instrument are presented. The results from over 500 primary and secondary
calibrator observations have allowed accurate determination of the flux
conversion factors (FCF) for the 850 and 450 micron arrays. Descriptions of the
instrument beam-shape and photometry methods are presented. The calibration
factors are well determined, with relative calibration accuracy better than 5
per cent at 850 microns and 10 per cent at 450 microns, reflecting the success
of the derived opacity relations as well as the stability of the performance of
the instrument over several months. The sample-size of the calibration
observations and accurate FCFs have allowed the determination of the 850 and
450 micron fluxes of several well-known submillimetre sources, and these
results are compared with previous measurements from SCUBA.


title:
Parabolic comparison principle and quasiminimizers in metric measure
  spaces

abstract:
  We give several characterizations of parabolic (quasisuper)- minimizers in a
metric measure space equipped with a doubling measure and supporting a
Poincar\'e inequality. We also prove a version of comparison principle for
super- and subminimizers on parabolic space-time cylinders and a uniqueness
result for minimizers of a boundary value problem. We also give an example
showing that the corresponding results do not hold, in general, for
quasiminimizers even in the Euclidean case.


title: Discriminative Recurrent Sparse Auto-Encoders

abstract:
  We present the discriminative recurrent sparse auto-encoder model, comprising
a recurrent encoder of rectified linear units, unrolled for a fixed number of
iterations, and connected to two linear decoders that reconstruct the input and
predict its supervised classification. Training via
backpropagation-through-time initially minimizes an unsupervised sparse
reconstruction error; the loss function is then augmented with a discriminative
term on the supervised classification. The depth implicit in the
temporally-unrolled form allows the system to exhibit all the power of deep
networks, while substantially reducing the number of trainable parameters.
  From an initially unstructured network the hidden units differentiate into
categorical-units, each of which represents an input prototype with a
well-defined class; and part-units representing deformations of these
prototypes. The learned organization of the recurrent encoder is hierarchical:
part-units are driven directly by the input, whereas the activity of
categorical-units builds up over time through interactions with the part-units.
Even using a small number of hidden units per layer, discriminative recurrent
sparse auto-encoders achieve excellent performance on MNIST.


title:
Thermodynamics of the apparent horizon in infrared modified
  Horava-Lifshitz gravity

abstract:
  It is well known that by applying the first law of thermodynamics to the
apparent horizon of a Friedmann-Robertson-Walker universe, one can derive the
corresponding Friedmann equations in Einstein, Gauss-Bonnet, and more general
Lovelock gravity. Is this a generic feature of any gravitational theory? Is the
prescription applicable to other gravities? In this paper we would like to
address the above questions by examining the same procedure for Horava-Lifshitz
gravity. We find that in Horava-Lifshitz gravity, this approach does not work
and we fail to reproduce a corresponding Friedmann equation in this theory by
applying the first law of thermodynamics on the apparent horizon, together with
the appropriate expression for the entropy in Horava-Lifshitz gravity. The
reason for this failure seems to be due to the fact that Horava-Lifshitz
gravity is not diffeomorphism invariant, and thus, the corresponding field
equation cannot be derived from the first law around horizon in the spacetime.
Without this, it implies that the specific gravitational theory is not
consistent, which shows an additional problematic feature of Horrava-Lifshitz
gravity. Nevertheless, if we still take the area formula of geometric entropy
and regard Horava-Lifshitz sector in the Friedmann equation as an effective
dark radiation, we are able to extract the corresponding Friedmann equation
from the first law of thermodynamics.


title: Non-Gaussianity and CMB aberration and Doppler

abstract:
  The peculiar motion of an observer with respect to the CMB rest frame induces
a deflection in the arrival direction of the observed photons (also known as
CMB aberration) and a Doppler shift in the measured photon frequencies. As a
consequence, aberration and Doppler effects induce non trivial correlations
between the harmonic coefficients of the observed CMB temperature maps. In this
paper we investigate whether these correlations generate a bias on
Non-Gaussianity estimators $f_{NL}$. We perform this analysis simulating a
large number of temperature maps with Planck-like resolution (lmax $= 2000$) as
different realizations of the same cosmological fiducial model (WMAP7yr). We
then add to these maps aberration and Doppler effects employing a modified
version of the HEALPix code. We finally evaluate a generalization of the
Komatsu, Spergel and Wandelt Non-Gaussianity estimator for all the simulated
maps, both when peculiar velocity effects have been considered and when these
phenomena have been neglected. Using the value $v/c=1.23 \times 10^{-3}$ for
our peculiar velocity, we found that the aberration/Doppler induced
Non-Gaussian signal is at most of about half of the cosmic variance $\sigma$
for $f_{NL}$ both in a full-sky and in a cut-sky experimental configuration,
for local, equilateral and orthogonal estimators. We conclude therefore that
when estimating $f_{NL}$ it is safe to ignore aberration and Doppler effects
{\it if} the primordial map is already Gaussian. More work is necessary however
to assess whether a map which contains Non-Gaussianity can be significantly
distorted by a peculiar velocity.


title:
The quantum transverse-field Ising chain in circuit QED: effects of
  disorder on the nonequilibrium dynamics

abstract:
  We study several dynamical properties of a recently proposed implementation
of the quantum transverse-field Ising chain in the framework of circuit QED.
Particular emphasis is placed on the effects of disorder on the nonequilibrium
behavior of the system. We show that small amounts of fabrication-induced
disorder in the system parameters do not jeopardize the observation of
previously-predicted phenomena. Based on a numerical extraction of the mean
free path of the system, we also provide a simple quantitative estimate for
certain disorder effects on the nonequilibrium dynamics of the circuit QED
quantum simulator. We discuss the transition from weak to strong disorder,
characterized by the onset of Anderson localization of the system's wave
functions, and the qualitatively different dynamics it leads to.


title:
Optimal system size for complex dynamics in random neural networks near
  criticality

abstract:
  In this Letter, we consider a model of dynamical agents coupled through a
random connectivity matrix, as introduced in [Sompolinsky et. al, 1988] in the
context of random neural networks. It is known that increasing the disorder
parameter induces a phase transition leading to chaotic dynamics. We observe
and investigate here a novel phenomenon in the subcritical regime : the
probability of observing complex dynamics is maximal for an intermediate system
size when the disorder is close enough to criticality. We give a more general
explanation of this type of system size resonance in the framework of extreme
values theory for eigenvalues of random matrices.


title:
Bounds on the Size of Sound Monotone Switching Networks Accepting
  Permutation Sets of Directed Trees

abstract:
  In this paper, we prove almost tight bounds on the size of sound monotone
switching networks accepting permutations sets of directed trees. This roughly
corresponds to proving almost tight bounds bounds on the monotone memory
efficiency of the directed ST-connectivity problem for the special case in
which the input graph is guaranteed to have no path from s to t or be
isomorphic to a specific directed tree.


title: Efficient Estimation of Word Representations in Vector Space

abstract:
  We propose two novel model architectures for computing continuous vector
representations of words from very large data sets. The quality of these
representations is measured in a word similarity task, and the results are
compared to the previously best performing techniques based on different types
of neural networks. We observe large improvements in accuracy at much lower
computational cost, i.e. it takes less than a day to learn high quality word
vectors from a 1.6 billion words data set. Furthermore, we show that these
vectors provide state-of-the-art performance on our test set for measuring
syntactic and semantic word similarities.


title:
The order-parameter symmetry and Fermi surface topology of 122 Fe-based
  superconductors: a point-contact Andreev-reflection study

abstract:
  We report on the results of directional point-contact Andreev-reflection
(PCAR) measurements in Ba(Fe_{1-x}Co_x)2As2 single crystals and epitaxial
c-axis oriented films with x = 0.08 as well as in Ca(Fe_{1-x}Co_x)2As2 single
crystals with x = 0.06. The PCAR spectra are analyzed within the two-band 3D
version of the Blonder-Tinkham-Klapwijk model for Andreev reflection we
recently developed, and that makes use of an analytical expression for the
Fermi surface that mimics the one calculated within the density-functional
theory (DFT). The spectra in Ca(Fe_{0.94}Co_{0.06})2As2 unambiguously
demonstrate the presence of nodes or zeros in the small gap. In
Ba(Fe_{0.92}Co_{0.08})2As2, the ab-plane spectra in single crystals can be
fitted by assuming two nodeless gaps, but this model fails to fit the c-axis
ones in epitaxial films. All these results are discussed in comparison with
recent theoretical predictions about the occurrence of accidental 3D nodes and
the presence of "hot spots" in the gaps of 122 compounds.


title:
Reproducing kernel Hilbert spaces of CR functions for the Euclidean
  Motion group

abstract:
  We study the geometric structure of the reproducing kernel Hilbert space
associated to the continuous wavelet transform generated by the irreducible
representations of the Euclidean Motion $SE(2)$. A natural Hilbert norm for
functions on the group is constructed that makes the wavelet transform an
isometry, but since the considered representations are not square integrable
the resulting Hilbert space will not coincide with $L^2(SE(2))$. The
reproducing kernel Hilbert subspace generated by the wavelet transform, for the
case of a minimal uncertainty mother wavelet, can be characterized in terms of
the complex regularity defined by the natural $CR$ structure of the group.
Relations with the Bargmann transform are presented.


title: Asymptotic Consensus Without Self-Confidence

abstract:
  This paper studies asymptotic consensus in systems in which agents do not
necessarily have self-confidence, i.e., may disregard their own value during
execution of the update rule. We show that the prevalent hypothesis of
self-confidence in many convergence results can be replaced by the existence of
aperiodic cores. These are stable aperiodic subgraphs, which allow to virtually
store information about an agent's value distributedly in the network. Our
results are applicable to systems with message delays and memory loss.


title: Nuclear Criticality as a Contributor to Gamma Ray Burst Events

abstract:
  Most gamma ray bursts are able to be explained using supernovae related
phenomenon. Some measured results still lack compelling explanations and a
contributory cause from nuclear criticality is proposed. This is shown to have
general properties consistent with various known gamma ray burst properties.
The galactic origin of fast rise exponential decay gamma ray bursts is
considered a strong candidate for these types of events.


title: Demonstration of a dressed-state phase gate for trapped ions

abstract:
  We demonstrate a trapped-ion entangling-gate scheme proposed by Bermudez et
al. [Phys. Rev. A 85, 040302 (2012)]. Simultaneous excitation of a strong
carrier and a single-sideband transition enables deterministic creation of
entangled states. The method works for magnetic field-insensitive states, is
robust against thermal excitations, includes dynamical decoupling from qubit
dephasing errors, and provides simplifications in experimental implementation
compared to some other entangling gates with trapped ions. We achieve a Bell
state fidelity of 0.974(4) and identify the main sources of error.


title: Modulated decay in the multi-component Universe

abstract:
  The early Universe after inflation may have oscillations, kinations
(nonoscillatory evolution of a field), topological defects, relativistic and
non-relativistic particles at the same time. The Universe whose energy density
is a sum of those components can be called the multi-component Universe. The
components, which may have distinguishable density scalings, may decay
modulated. In this paper we study generation of the curvature perturbations
caused by the modulated decay in the multi-component Universe.


title: Quantum Photovoltaic Effect in Double Quantum Dots

abstract:
  We analyze the photovoltaic current through a double quantum dot system
coupled to a high-quality driven microwave resonator. The conversion of photons
in the resonator to electronic excitations produces a current flow even at zero
bias across the leads of the double quantum dot system. We demonstrate that due
to the quantum nature of the electromagnetic field in the resonator, the
photovoltaic current exhibits a double peak dependence on the frequency
$\omega$ of an external microwave source. The distance between the peaks is
determined by the strength of interaction between photons in the resonator and
electrons in the double quantum dot. The double peak structure disappears as
strengths of relaxation processes increases, recovering a simple classical
condition for maximal current when the microwave frequency is equal to the
resonator frequency.


title:
Exploring the non-linear density field in the Millennium simulations
  with tessellations - I. The probability distribution function

abstract:
  We use the Delaunay Tessellation Field Estimator (DTFE) to study the
one-point density distribution functions of the Millennium (MS) and
Millennium-II (MS-II) simulations. The DTFE technique is based directly on the
particle positions, without requiring any type of smoothing or analysis grid,
thereby providing high sensitivity to all non-linear structures resolved by the
simulations. In order to identify the detailed origin of the shape of the
one-point density probability distribution function (PDF), we decompose the
simulation particles according to the mass of their host FoF halos, and examine
the contributions of different halo mass ranges to the global density PDF. We
model the one-point distribution of the FoF halos in each halo mass bin with a
set of Monte Carlo realizations of idealized NFW dark matter halos, finding
that this reproduces the measurements from the N-body simulations reasonably
well, except for a small excess present in simulation results. This excess
increases with increasing halo mass. We show that its origin lies in
substructure, which becomes progressively more abundant and better resolved in
more massive dark matter halos. We demonstrate that the high density tail of
the one-point distribution function in less massive halos is severely affected
by the gravitational softening length and the mass resolution. In particular,
we find these two parameters to be more important for an accurate measurement
of the density PDF than the simulated volume. Combining our results from
individual halo mass bins we find that the part of the one-point density PDF
originating from collapsed halos can nevertheless be quite well described by a
simple superposition of a set of NFW halos with the expected cosmological
abundance over the resolved mass range. The transition region to the
low-density unbound material is however not well captured by such an analytic
halo model.


title: Limit sets of stable Cellular Automata

abstract:
  We study limit sets of stable cellular automata standing from a symbolic
dynamics point of view where they are a special case of sofic shifts admitting
a steady epimorphism. We prove that there exists a right-closing
almost-everywhere steady factor map from one irreducible sofic shift onto
another one if and only if there exists such a map from the domain onto the
minimal right-resolving cover of the image. We define right-continuing
almost-everywhere steady maps and prove that there exists such a steady map
between two sofic shifts if and only if there exists a factor map from the
domain onto the minimal right-resolving cover of the image. In terms of
cellular automata, this translates into: A sofic shift can be the limit set of
a stable cellular automaton with a right-closing almost-everywhere dynamics
onto its limit set if and only if it is the factor of a fullshift and there
exists a right- closing almost-everywhere factor map from the sofic shift onto
its minimal right- resolving cover. A sofic shift can be the limit set of a
stable cellular automaton reaching its limit set with a right-continuing
almost-everywhere factor map if and only if it is the factor of a fullshift and
there exists a factor map from the sofic shift onto its minimal right-resolving
cover. Finally, as a consequence of the previous results, we provide a
characterization of the Almost of Finite Type shifts (AFT) in terms of a
property of steady maps that have them as range.


title: XORing Elephants: Novel Erasure Codes for Big Data

abstract:
  Distributed storage systems for large clusters typically use replication to
provide reliability. Recently, erasure codes have been used to reduce the large
storage overhead of three-replicated systems. Reed-Solomon codes are the
standard design choice and their high repair cost is often considered an
unavoidable price to pay for high storage efficiency and high reliability.
  This paper shows how to overcome this limitation. We present a novel family
of erasure codes that are efficiently repairable and offer higher reliability
compared to Reed-Solomon codes. We show analytically that our codes are optimal
on a recently identified tradeoff between locality and minimum distance.
  We implement our new codes in Hadoop HDFS and compare to a currently deployed
HDFS module that uses Reed-Solomon codes. Our modified HDFS implementation
shows a reduction of approximately 2x on the repair disk I/O and repair network
traffic. The disadvantage of the new coding scheme is that it requires 14% more
storage compared to Reed-Solomon codes, an overhead shown to be information
theoretically optimal to obtain locality. Because the new codes repair failures
faster, this provides higher reliability, which is orders of magnitude higher
compared to replication.


title:
Search for physics beyond the standard model in events with tau leptons,
  jets, and large transverse momentum imbalance in pp collisions at sqrt(s) = 7
  TeV

abstract:
  A search for physics beyond the standard model is performed with events
having one or more hadronically decaying tau leptons, highly energetic jets,
and large transverse momentum imbalance. The data sample corresponds to an
integrated luminosity of 4.98 inverse femtobarns of proton-proton collisions at
sqrt(s) = 7 TeV collected with the CMS detector at the LHC in 2011. The number
of observed events is consistent with predictions for standard model processes.
Lower limits on the mass of the gluino in supersymmetric models are determined.


title: Identities involving Laguerre polynomials derived from umbral calculus

abstract:
  In this paper, we investigate some identities of Laguerre polynomials
involving Bernoulli and Euler polynomials which are derived from umbral
calculus.


title:
A fast multigrid-based electromagnetic eigensolver for curved metal
  boundaries on the Yee mesh

abstract:
  For embedded boundary electromagnetics using the Dey-Mittra algorithm, a
special grad-div matrix constructed in this work allows use of multigrid
methods for efficient inversion of Maxwell's curl-curl matrix. Efficient
curl-curl inversions are demonstrated within a shift-and-invert Krylov-subspace
eigensolver (open-sourced at https://github.com/bauerca/maxwell) on the
spherical cavity and the 9-cell TESLA superconducting accelerator cavity. The
accuracy of the Dey-Mittra algorithm is also examined: frequencies converge
with second-order error, and surface fields are found to converge with nearly
second-order error. In agreement with previous work, neglecting some
boundary-cut cell faces (as is required in the time domain for numerical
stability) reduces frequency convergence to first-order and surface-field
convergence to zeroth-order (i.e. surface fields do not converge). Additionally
and importantly, neglecting faces can reduce accuracy by an order of magnitude
at low resolutions.


title:
Raman-scattering study of the phonon dispersion in twisted bi-layer
  graphene

abstract:
  Bi-layer graphene with a twist angle \theta\ between the layers generates a
superlattice structure known as Moir\'{e} pattern. This superlattice provides a
\theta-dependent q wavevector that activates phonons in the interior of the
Brillouin zone. Here we show that this superlattice-induced Raman scattering
can be used to probe the phonon dispersion in twisted bi-layer graphene (tBLG).
The effect reported here is different from the broadly studied double-resonance
in graphene-related materials in many aspects, and despite the absence of
stacking order in tBLG, layer breathing vibrations (namely ZO' phonons) are
observed.


title:
On holographic thermalization and gravitational collapse of tachyonic
  scalar fields

abstract:
  In this paper we study the thermalization of a spatially homogeneous system
in a strongly coupled CFT. The non-equilibrium initial state is created by
switching on a relevant perturbation in the CFT vacuum during Delta t >= t >=
-Delta t. Via AdS/CFT, the thermalization process corresponds to the
gravitational collapse of a tachyonic scalar field (m^2 = -3) in the Poincare
patch of AdS_5. In the limit Delta t < 0.02/T, the thermalization time t_T is
found to be quantitatively the same as that of a non-equilibrium state created
by a marginal perturbation discussed in Ref. [5]. In the case Delta t >= 1/T,
we also obtain double-collapse solutions but with a non-equilibrium
intermediate state at t = 0. In all the cases our results show that the system
thermalizes in a typical time t_T ~ O(1)/T. Besides, a conserved energy-moment
current in the bulk is found, which helps understand the qualitative difference
of the collapse process in the Poincare patch from that in global AdS[9, 10].


title:
MeV electrons detected by the Alice UV spectrograph during the New
  Horizons flyby of Jupiter

abstract:
  In early 2007, the New Horizons spacecraft flew through the Jovian
magnetosphere on the dusk side. Here, we present results from a novel means of
detecting energetic electrons along New Horizons' trajectory: the background
count rate of the Alice ultraviolet spectrograph. Electrons with energies >1
MeV can penetrate the thin aluminum housing of Alice, interact with the
microchannel plate detector, and produce a count that is indistinguishable from
an FUV photon. We present Alice data, proportional to the MeV electron flux,
from an 11-day period centered on the spacecraft's closest approach to Jupiter,
and compare it to electron data from the PEPSSI instrument. We find that a
solar wind compression event passed over the spacecraft just prior to it
entering the Jovian magnetosphere. Subsequently, the magnetopause boundary was
detected at a distance of 67 R_J suggesting a compressed magnetospheric
configuration. Three days later, when the spacecraft was 35-90 R_J downstream
of Jupiter, New Horizons observed a series of 15 current sheet crossings, all
of which occurred significantly northward of model predictions implying solar
wind influence over the middle and outer Jovian magnetosphere, even to radial
distances as small as ~35 R_J. In addition, we find the Jovian current sheet,
which had a half-thickness of at least 7.4 R_J between 1930 and 2100 LT
abruptly thinned to a thickness of ~3.4 R_J around 2200 LT.


title:
Root's barrier, viscosity solutions of obstacle problems and reflected
  FBSDEs

abstract:
  We revisit work of Rost, Dupire and Cox--Wang on connections between Root's
solution of the Skorokhod embedding problem and obstacle problems. We develop
an approach based on viscosity sub- and supersolutions and an accompanying
comparison principle. This gives a complete characterization of (reversed) Root
barriers and leads to new proofs of existence as well as minimality of such
barrier solutions by pure PDE methods. The approach is self-contained and
general enough to cover martingale diffusions with degenerate elliptic or
time-dependent volatility; it also provides insights about the dynamics of
general Skorokhod embeddings.


title:
A Levy-area between Brownian motion and rough paths with applications to
  robust non-linear filtering and RPDEs

abstract:
  We give meaning to differential equations with a rough path term and a
Brownian noise term as driving signals. Such differential equations as well as
the question of regularity of the solution map arise naturally and we discuss
two applications: one revisits Clark's robustness problem in nonlinear
filtering, the other is a Feynman--Kac type representation of linear RPDEs. En
passant, we give a short and direct argument that implies integrability
estimates for rough differential equations with Gaussian driving signals which
is of independent interest.


title:
Time step rescaling recovers continuous-time dynamical properties for
  discrete-time Langevin integration of nonequilibrium systems

abstract:
  When simulating molecular systems using deterministic equations of motion
(e.g., Newtonian dynamics), such equations are generally numerically integrated
according to a well-developed set of algorithms that share commonly agreed-upon
desirable properties. However, for stochastic equations of motion (e.g.,
Langevin dynamics), there is still broad disagreement over which integration
algorithms are most appropriate. While multiple desiderata have been proposed
throughout the literature, consensus on which criteria are important is absent,
and no published integration scheme satisfies all desiderata simultaneously.
Additional nontrivial complications stem from simulating systems driven out of
equilibrium using existing stochastic integration schemes in conjunction with
recently-developed nonequilibrium fluctuation theorems. Here, we examine a
family of discrete time integration schemes for Langevin dynamics, assessing
how each member satisfies a variety of desiderata that have been enumerated in
prior efforts to construct suitable Langevin integrators. We show that the
incorporation of a novel time step rescaling in the deterministic updates of
position and velocity can correct a number of dynamical defects in these
integrators. Finally, we identify a particular splitting that has essentially
universally appropriate properties for the simulation of Langevin dynamics for
molecular systems in equilibrium, nonequilibrium, and path sampling contexts.


title:
Kinematic and dynamic vortices in a thin film driven by an applied
  current and magnetic field

abstract:
  Using a Ginzburg-Landau model, we study the vortex behavior of a rectangular
thin film superconductor subjected to an applied current fed into a portion of
the sides and an applied magnetic field directed orthogonal to the film.
  Through a center manifold reduction we develop a rigorous bifurcation theory
for the appearance of periodic solutions in certain parameter regimes near the
normal state. The leading order dynamics yield in particular a motion law for
kinematic vortices moving up and down the center line of the sample. We also
present computations that reveal the co-existence and periodic evolution of
kinematic and magnetic vortices.


title: Dynamics of localized modes in a composite multiferroic chain

abstract:
  In a coupled ferroelectric/ferromagnetic system, i.e. a composite
multiferroic, the propagation of magnetic or ferroelectric excitations across
the whole structure is a key issue for applications. Of a special interest is
the dynamics of localized magnetic or ferroelectric modes (LM) across the
ferroelectric-ferromagnetic interface, particularly when the LM's carrier
frequency is in the band of the ferroelectric and in the band gap of the
ferromagnet. For a proper choice of the system's parameters, we find that there
is a threshold amplitude above which the interface becomes transparent and a
band gap ferroelectric LM penetrates the ferromagnetic array. Below that
threshold, the LM is fully reflected. Slightly below this transmission
threshold, the addition of noise may lead to energy transmission, provided that
the noise level is not too low nor too high, an effect that resembles
stochastic resonance. These findings represent an important step towards the
application of ferroelectric and/or ferromagnetic LM-based logic.


title:
Link invariants from finite categorical groups and braided crossed
  modules

abstract:
  We define an invariant of tangles and framed tangles given a finite crossed
module and a pair of functions, called a Reidemeister pair, satisfying natural
properties. We give several examples of Reidemeister pairs derived from racks,
quandles, rack and quandle cocycles, 2-crossed modules and braided crossed
modules. We prove that our construction includes all rack and quandle
cohomology (framed) link invariants, as well as the Eisermann invariant of
knots, for which we also find a lifting by using braided crossed modules.


title: A Search for Vulcanoids with the STEREO Heliospheric Imager

abstract:
  Interior to the orbit of Mercury, between 0.07 and 0.21 AU, is a dynamically
stable region where a population of asteroids, known as Vulcanoids, may reside.
We present the results from our search for Vulcanoids using archival data from
the Heliospheric Imager-1 (HI-1) instrument on NASA's two STEREO spacecraft.
Four separate observers independently searched through images obtained from
2008-12-10 to 2009-02-28. Roughly, all Vulcanoids with e<=0.15 and i<=15deg
will pass through the HI-1 field of view at least twice during this period. No
Vulcanoids were detected. Based on the number of synthetic Vulcanoids added to
the data that were detected, we derive a 3 sigma upper limit (i.e. a confidence
level >0.997) that there are presently no Vulcanoids larger than 5.7 km in
diameter, assuming an R-band albedo of p_R=0.05 and a Mercury-like phase
function. The present-day Vulcanoid population, if it exists at all, is likely
a small remnant of the hypothetical primordial Vulcanoid population due to the
combined effects of collisional evolution and subsequent radiative transport of
collisional fragments. If we assume an extant Vulcanoid population with a
collisional equilibrium differential size distribution with a power law index
of -3.5, our limit implies that there are no more than 76 Vulcanoids larger
than 1 km.


title:
Herschel Observations of the W3 GMC: Clues to the Formation of Clusters
  of High-Mass Stars

abstract:
  The W3 GMC is a prime target for the study of the early stages of high-mass
star formation. We have used Herschel data from the HOBYS key program to
produce and analyze column density and temperature maps. Two preliminary
catalogs were produced by extracting sources from the column density map and
from Herschel maps convolved to the 500 micron resolution. Herschel reveals
that among the compact sources (FWHM<0.45 pc), W3 East, W3 West, and W3 (OH)
are the most massive and luminous and have the highest column density.
Considering the unique properties of W3 East and W3 West, the only clumps with
on-going high-mass star formation, we suggest a 'convergent constructive
feedback' scenario to account for the formation of a cluster with decreasing
age and increasing system/source mass toward the innermost regions. This
process, which relies on feedback by high-mass stars to ensure the availability
of material during cluster formation, could also lead to the creation of an
environment suitable for the formation of Trapezium-like systems. In common
with other scenarios proposed in other HOBYS studies, our results indicate that
an active/dynamic process aiding in the accumulation, compression, and
confinement of material is a critical feature of the high-mass star/cluster
formation, distinguishing it from classical low-mass star formation. The
environmental conditions and availability of triggers determine the form in
which this process occurs, implying that high-mass star/cluster formation could
arise from a range of scenarios: from large scale convergence of turbulent
flows, to convergent constructive feedback or mergers of filaments.


title:
Time evolution of local observables after quenching to an integrable
  model

abstract:
  We consider quantum quenches in integrable models. We argue that the
behaviour of local observables at late times after the quench is given by their
expectation values with respect to a single representative Hamiltonian
eigenstate. This can be viewed as a generalization of the eigenstate
thermalization hypothesis to quantum integrable models. We present a method for
constructing this representative state by means of a generalized Thermodynamic
Bethe Ansatz (GTBA). Going further, we introduce a framework for calculating
the time dependence of local observables as they evolve towards their
stationary values. As an explicit example we consider quantum quenches in the
transverse-field Ising chain and show that previously derived results are
recovered efficiently within our framework.


title:
Numerical simulation of the dynamics of molecular markers involved in
  cell polarisation

abstract:
  A cell is polarised when it has developed a main axis of organisation through
the reorganisation of its cytosqueleton and its intracellular organelles.
Polarisation can occur spontaneously or be triggered by external signals, like
gradients of signaling molecules ... In this work, we study mathematical models
for cell polarisation. These models are based on nonlinear convection-diffusion
equations. The nonlinearity in the transport term expresses the positive loop
between the level of protein concentration localised in a small area of the
cell membrane and the number of new proteins that will be convected to the same
area. We perform numerical simulations and we illustrate that these models are
rich enough to describe the apparition of a polarisome.


title:
Formation of Regular Satellites from Ancient Massive Rings in the Solar
  System

abstract:
  When a planetary tidal disk -like Saturn's rings- spreads beyond the Roche
radius (inside which planetary tides prevent aggregation), satellites form and
migrate away. Here, we show that most regular satellites in the solar system
probably formed in this way. According to our analytical model, when the
spreading is slow, a retinue of satellites appear with masses increasing with
distance to the Roche radius, in excellent agreement with Saturn's, Uranus',
and Neptune's satellite systems. This suggests that Uranus and Neptune used to
have massive rings that disappeared to give birth to most of their regular
satellites. When the spreading is fast, only one large satellite forms, as was
the case for Pluto and Earth. This conceptually bridges the gap between
terrestrial and giant planet systems.


title: Quantum quench dynamics of the Coulomb Luttinger model

abstract:
  We study the non-equilibrium dynamics of the Luttinger model after suddenly
turning on and off the bare Coulomb interaction between the fermions. We
analyze several correlation functions such as the one particle density matrix
and vertex correlations, its finite time dynamics and the stationary state
limit. Correlations exhibit a non-linear light cone effect: the spreading of
the initial signal accelerates as a consequence of the quantum nature of the
excitations, whose peculiar dispersion of plasmonic type in 1D gives rise to a
logarithmic divergence in the group velocity at $q=0$. In addition we show that
both the static and dynamic stationary state correlations can be reproduced
with a simple generalised Gibbs ensemble despite the long-range character of
the interactions which precludes the application of the Lieb-Robinson bounds.
We propose a suitable experimental setup in which these effect can be observed
based on ultracold ions loaded on linear traps.


title:
Orthogonal Polynomials on the Unit Circle with quasiperiodic Verblunsky
  Coefficients have generic purely singular continuous spectrum

abstract:
  As an application of the Gordon lemma for orthogonal polynomials on the unit
circle, we prove that for a generic set of quasiperiodic Verblunsky
coefficients the corresponding two-sided CMV operator has purely singular
continuous spectrum. We use a similar argument to that of the
Boshernitzan-Damanik result that establishes the corresponding theorem for the
discrete Schr\"odinger operator.


title: Interval non-edge-colorable bipartite graphs and multigraphs

abstract:
  An edge-coloring of a graph $G$ with colors $1,...,t$ is called an interval
$t$-coloring if all colors are used, and the colors of edges incident to any
vertex of $G$ are distinct and form an interval of integers. In 1991 Erd\H{o}s
constructed a bipartite graph with 27 vertices and maximum degree 13 which has
no interval coloring. Erd\H{o}s's counterexample is the smallest (in a sense of
maximum degree) known bipartite graph which is not interval colorable. On the
other hand, in 1992 Hansen showed that all bipartite graphs with maximum degree
at most 3 have an interval coloring. In this paper we give some methods for
constructing of interval non-edge-colorable bipartite graphs. In particular, by
these methods, we construct three bipartite graphs which have no interval
coloring, contain 20,19,21 vertices and have maximum degree 11,12,13,
respectively. This partially answers a question that arose in [T.R. Jensen, B.
Toft, Graph coloring problems, Wiley Interscience Series in Discrete
Mathematics and Optimization, 1995, p. 204]. We also consider similar problems
for bipartite multigraphs.


title: Flavour Symmetric Mass Matrices

abstract:
  The structure of flavour space is determined by the form of the quark mass
matrices in the weak flavour space basis. We examine some matrix textures in
the light of flavour permutations symmetry arguments, for three and four
families.


title: Cassini UVIS observations of the Io plasma torus. II. Radial variations

abstract:
  On January 14, 2001, shortly after the Cassini spacecraft's closest approach
to Jupiter, the Ultraviolet Imaging Spectrometer (UVIS) made a radial scan
through the midnight sector of Io plasma torus. The Io torus has not been
previously observed at this local time. The UVIS data consist of 2-D spectrally
dispersed images of the Io plasma torus in the wavelength range of
561{\AA}-1912{\AA}. We developed a spectral emissions model that incorporates
the latest atomic physics data contained in the CHIANTI database in order to
derive the composition of the torus plasma as a function of radial distance.
Electron temperatures derived from the UVIS torus spectra are generally less
than those observed during the Voyager era. We find the torus ion composition
derived from the UVIS spectra to be significantly different from the
composition during the Voyager era. Notably, the torus contains substantially
less oxygen, with a total oxygen-to-sulfur ion ratio of 0.9. The average ion
charge state has increased to 1.7. We detect S V in the Io torus at the
3{\sigma} level. S V has a mixing ratio of 0.5%. The spectral emission model
used in can approximate the effects of a non-thermal distribution of electrons.
The ion composition derived using a kappa distribution of electrons is
identical to that derived using a Maxwellian electron distribution; however,
the kappa distribution model requires a higher electron column density to match
the observed brightness of the spectra. The derived value of the kappa
parameter decreases with radial distance and is consistent with the value of
{\kappa}=2.4 at 8 RJ derived by the Ulysses URAP instrument (Meyer-Vernet et
al., 1995). The observed radial profile of electron column density is
consistent with a flux tube content, NL^2, that is proportional to r^-2.


title:
THEMIS Observations of the Magnetopause Electron Diffusion Region: Large
  Amplitude Waves and Heated Electrons

abstract:
  We present the first observations of large amplitude waves in a well-defined
electron diffusion region at the sub-solar magnetopause using data from one
THEMIS satellite. These waves identified as whistler mode waves, electrostatic
solitary waves, lower hybrid waves and electrostatic electron cyclotron waves,
are observed in the same 12-sec waveform capture and in association with
signatures of active magnetic reconnection. The large amplitude waves in the
electron diffusion region are coincident with abrupt increases in electron
parallel temperature suggesting strong wave heating. The whistler mode waves
which are at the electron scale and enable us to probe electron dynamics in the
diffusion region were analyzed in detail. The energetic electrons (~30 keV)
within the electron diffusion region have anisotropic distributions with
T_{e\perp}/T_{e\parallel}>1 that may provide the free energy for the whistler
mode waves. The energetic anisotropic electrons may be produced during the
reconnection process. The whistler mode waves propagate away from the center of
the 'X-line' along magnetic field lines, suggesting that the electron diffusion
region is a possible source region of the whistler mode waves.


title: Universality of K-Theory

abstract:
  We prove that graded K-theory is universal among oriented Borel-Moore
homology theories with a multiplicative periodic formal group law.