title: Planar graph is on fire

abstract:
  Let $G$ be any connected graph on $n$ vertices, $n \ge 2.$ Let $k$ be any
positive integer. Suppose that a fire breaks out on some vertex of $G.$ Then in
each turn $k$ firefighters can protect vertices of $G$ --- each can protect one
vertex not yet on fire; Next a fire spreads to all unprotected neighbours.
  The \emph{$k$-surviving} rate of G, denoted by $\rho_k(G),$ is the expected
fraction of vertices that can be saved from the fire by $k$ firefighters,
provided that the starting vertex is chosen uniformly at random. In this paper,
it is shown that for any planar graph $G$ we have $\rho_3(G) \ge \frac{2}{21}.$
Moreover, 3 firefighters are needed for the first step only; after that it is
enough to have 2 firefighters per each round. This result significantly
improves known solutions to a problem of Cai and Wang (there was no positive
bound known for surviving rate of general planar graph with only 3
firefighters). The proof is done using the separator theorem for planar graphs.


title:
Parton energy loss in the mini quark-gluon plasma and jet quenching in
  proton-proton collisions

abstract:
  We evaluate the medium suppression of light hadron spectra in $pp$ collisions
at RHIC and LHC energies in the scenario with formation of a mini quark-gluon
plasma. We find a significant suppression effect. For $p_{T}\sim 10$ GeV we
obtained the reduction of the spectra by $\sim [20-30,25-35,30-40]$ % at
$\sqrt{s}=[0.2, 2.76,7]$ TeV. We also discuss how this phenomenon may change
the predictions for the nuclear modification factors for $AA$ and $pA$
collisions.


title:
Higher Order Corrections to the Asymptotic Perturbative Solution of a
  Schwinger-Dyson Equation

abstract:
  Building on our previous works on perturbative solutions to a Schwinger-Dyson
for the massless Wess-Zumino model, we show how to compute 1/n corrections to
its asymptotic behavior. The coefficients are analytically determined through a
sum on all the poles of the Mellin transform of the one loop diagram. We
present results up to the fourth order in 1/n as well as a comparison with
numerical results. Unexpected cancellations of zetas are observed in the
solution, so that no even zetas appear and the weight of the coefficients is
lower than expected, which suggests the existence of more structure in the
theory.


title: On the greatest prime factor of ab+1

abstract:
  We improve some results on the size of the greatest prime factor of integers
of the form ab+1, where a and b belong to finite sets of integers with rather
large density.


title: Semantic Stability in Social Tagging Streams

abstract:
  One potential disadvantage of social tagging systems is that due to the lack
of a centralized vocabulary, a crowd of users may never manage to reach a
consensus on the description of resources (e.g., books, users or songs) on the
Web. Yet, previous research has provided interesting evidence that the tag
distributions of resources may become semantically stable over time as more and
more users tag them. At the same time, previous work has raised an array of new
questions such as: (i) How can we assess the semantic stability of social
tagging systems in a robust and methodical way? (ii) Does semantic
stabilization of tags vary across different social tagging systems and
ultimately, (iii) what are the factors that can explain semantic stabilization
in such systems? In this work we tackle these questions by (i) presenting a
novel and robust method which overcomes a number of limitations in existing
methods, (ii) empirically investigating semantic stabilization processes in a
wide range of social tagging systems with distinct domains and properties and
(iii) detecting potential causes for semantic stabilization, specifically
imitation behavior, shared background knowledge and intrinsic properties of
natural language. Our results show that tagging streams which are generated by
a combination of imitation dynamics and shared background knowledge exhibit
faster and higher semantic stability than tagging streams which are generated
via imitation dynamics or natural language streams alone.


title: Sparse Time-Frequency decomposition by dictionary learning

abstract:
  In this paper, we propose a time-frequency analysis method to obtain
instantaneous frequencies and the corresponding decomposition by solving an
optimization problem. In this optimization problem, the basis to decompose the
signal is not known. Instead, it is adapted to the signal and is determined as
part of the optimization problem. In this sense, this optimization problem can
be seen as a dictionary learning problem. This dictionary learning problem is
solved by using the Augmented Lagrangian Multiplier method (ALM) iteratively.
We further accelerate the convergence of the ALM method in each iteration by
using the fast wavelet transform. We apply our method to decompose several
signals, including signals with poor scale separation, signals with outliers
and polluted by noise and a real signal. The results show that this method can
give accurate recovery of both the instantaneous frequencies and the intrinsic
mode functions.


title: Testing No-Scale Supergravity with the Fermi Space Telescope LAT

abstract:
  We describe a methodology for testing No-Scale Supergravity by the LAT
instrument onboard the Fermi Space Telescope via observation of gamma ray
emissions from lightest supersymmetric (SUSY) neutralino annihilations. For our
test vehicle we engage the framework of the supersymmetric grand unified model
No-Scale Flipped $SU(5)$ with extra vector-like flippon multiplets derived from
F-Theory, known as $\cal{F}$-$SU(5)$. We show that through compression of the
light stau and light bino neutralino mass difference, where internal
bremsstrahlung (IB) photons give a dominant contribution, the photon yield from
annihilation of SUSY dark matter can be elevated to a number of events
potentially observable by the Fermi-LAT in the coming years. Likewise, the
increased yield in No-Scale $\cal{F}$-$SU(5)$ may also have rendered the
existing observation of a 133 GeV monochromatic gamma ray line visible, if
additional data should exclude systematic or statistical explanations. The
question of intensity aside, No-Scale $\cal{F}$-$SU(5)$ can indeed provide a
natural weakly interacting massive particle (WIMP) candidate with a mass in the
correct range to yield $\gamma \gamma$ and $\gamma Z$ emission lines at
$m_{\chi} \sim 133$ GeV and $m_{\chi} \sim 145$ GeV, respectively.
Additionally, we elucidate the emerging empirical connection between recent
Planck satellite data and No-Scale Supergravity cosmological models which mimic
the Starobinsky model of inflation. Together, these experiments furnish rich
alternate avenues for testing No-Scale $\cal{F}$-$SU(5)$, and similarly
structured models, the results of which may lend independent credence to
observations made at the LHC.


title: On the zeros of the big $q$-Bessel functions and applications

abstract:
  This paper deals with the study of the zeros of the big $q$-Bessel functions.
In particular, we prove a new orthogonality relations for this functions
similar to the one for the classical Bessel functions. Also we give some
applications related to the sampling theory.


title: A note on spherical maxima sharing the same Lagrange multiplier

abstract:
  In this paper, we establish a general result on spherical maxima sharing the
same Lagrange multiplier of which the following is a particular consequence:
Let $X$ be a real Hilbert space. For each $r>0$, let $S_r=\{x\in X :
\|x\|^2=r\}$. Let $J:X\to {\bf R}$ be a sequentially weakly upper
semicontinuous functional which is G\^ateaux differentiable in $X\setminus
\{0\}$. Assume that $$\limsup_{x\to 0}{{J(x)}\over {\|x\|^2}}=+\infty\ .$$
Then, for each $\rho>0$, there exists an open interval $I\subseteq ]0,+\infty[$
and an increasing function $\varphi:I\to ]0,\rho[$ such that, for each
$\lambda\in I$, one has $$\emptyset\neq \left \{x\in S_{\varphi(\lambda)} :
J(x)=\sup_{S_{\varphi(\lambda)}}J\right\}\subseteq \{x\in X : x=\lambda
J'(x)\}\ .$$


title: The final-parsec problem in non-spherical galaxies revisited

abstract:
  We consider the evolution of supermassive black hole binaries at the center
of spherical, axisymmetric, and triaxial galaxies, using direct N-body
integrations as well as analytic estimates. We find that the rates of binary
hardening exhibit a significant N-dependence in all the models, at least for N
in the investigated range of 10^5<=N<=10^6. Binary hardening rates are also
substantially lower than would be expected if the binary loss cone remained
full, as it would be if the orbits supplying stars to the binary were being
efficiently replenished. The difference in binary hardening rates between the
spherical and nonspherical models is less than a factor of two even in the
simulations with the largest N. By studying the orbital populations of our
models, we conclude that the rate of supply of stars to the binary via draining
of centrophilic orbits is indeed expected to be much lower than the
full-loss-cone rate, consistent with our simulations. We argue that the
binary's evolution in the simulations is driven in roughly equal amounts by
collisional and collisionless effects, even at the highest N-values currently
accessible. While binary hardening rates would probably reach a limiting value
for large N, our results suggest that we cannot approach that rate with
currently available algorithms and computing hardware. The extrapolation of
results from N-body simulations to real galaxies is therefore not
straightforward, casting doubt on recent claims that triaxiality or axisymmetry
alone are capable of solving the final-parsec problem in gas-free galaxies.


title: Numerical Evidence for Firewalls

abstract:
  We study thermal configurations in the BFSS matrix model produced by
numerical simulations. We do this by adding a probe brane to a typical
configuration and studying the fermionic degrees of freedom connecting the
probe to the configuration. Depending on the parameters of the probe there is a
region where these fermion modes are gapless. We argue that it is natural to
excise the gapless region from the geometry and that the black hole horizon is
located exactly at the edge of this zone. The physics inside the gapless region
is maximally non-local and effectively 1+1 dimensional. When a probe,
considered as an observer, crosses into the gapless zone there is a break down
of effective field theory where the off-diagonal fermions are integrated out.
We argue that this breakdown of effective field theory is evidence for
firewalls on black hole horizons.


title:
Using Robust PCA to estimate regional characteristics of language use
  from geo-tagged Twitter messages

abstract:
  Principal component analysis (PCA) and related techniques have been
successfully employed in natural language processing. Text mining applications
in the age of the online social media (OSM) face new challenges due to
properties specific to these use cases (e.g. spelling issues specific to texts
posted by users, the presence of spammers and bots, service announcements,
etc.). In this paper, we employ a Robust PCA technique to separate typical
outliers and highly localized topics from the low-dimensional structure present
in language use in online social networks. Our focus is on identifying
geospatial features among the messages posted by the users of the Twitter
microblogging service. Using a dataset which consists of over 200 million
geolocated tweets collected over the course of a year, we investigate whether
the information present in word usage frequencies can be used to identify
regional features of language use and topics of interest. Using the PCA pursuit
method, we are able to identify important low-dimensional features, which
constitute smoothly varying functions of the geographic location.


title: Characterizing Distant Worlds with Asterodensity Profiling

abstract:
  Eclipsing systems, such as transiting exoplanets, allow one to measure the
mean stellar density of the host star under various idealized assumptions.
Asterodensity Profiling (AP) compares this density to an independently
determined value in order to check the validity of the assumptions and
ultimately derive useful parameters. Several physical effects can cause said
assumptions to become invalid, with the most well-known example being the
so-called photo-eccentric effect. In this work, we provide analytic expressions
for five other effects which induce AP deviations: the photo-blend, -spot,
-timing, -duration and -mass effects. We find that these effects can easily
reproduce large AP deviations and so we caution that extracting the
eccentricity distribution is only viable with careful consideration of the
prior distributions for these other effects. We also re-investigate the
photo-eccentric effect and derive a single-domain minimum eccentricity
expression and the parameter range for which analytic formulae are valid. This
latter result shows that the assumptions underlying the analytic model for the
photo-eccentric effect break down for close-in, highly-eccentric planets,
meaning that extreme care must be taken in this regime. Finally, we demonstrate
that contaminated light fraction can be solved for, indicating that AP could be
a potent tool for planet validation.


title:
Estimating the effects of sea level rise on coupled estuarine nitrogen
  cycling processes through comparative network analysis

abstract:
  Nitrogen (N) removal from estuaries is driven in part by sedimentary
microbial processes. The processes of denitrification and anaerobic ammonium
oxidation (anammox) remove N from estuaries by producing di-nitrogen gas, and
each can be coupled to N recycling pathways such as nitrification and
dissimilatory nitrate reduction to ammonium (DNRA). Environmental conditions in
estuaries influence sedimentary N cycling processes; therefore, seawater
intrusion may affect the coupling of N cycling processes in the freshwater
portions of estuaries. This study investigated the potential effects of
seawater intrusion on these process couplings through a comparative modeling
approach. We applied environ analysis, a form of ecological network analysis,
to two N cycling mass-balance network models constructed at freshwater
(oligohaline) and saltwater (polyhaline) sites in the Cape Fear River Estuary,
North Carolina. We used a space-for-time substitution to predict the effects of
seawater intrusion on the sedimentary N cycle. Further, we conducted an
uncertainty analysis using linear inverse modeling to evaluate the effects of
parameterization uncertainty on model results. Nitrification coupled to both
denitrification and anammox was 2.5 times greater in the oligohaline model,
while DNRA coupled to anammox was 2.7 times greater in the polyhaline model.
However, the total amount of N2 gas produced relative to the nitrogen inputs to
each network was 4.7% and 4.6% at the oligohaline and polyhaline sites,
respectively. These findings suggest that changes in water chemistry from
seawater intrusion may favor direct over coupled nitrogen removal, but may not
substantially change the N removal capacity of the sedimentary microbial
processes.


title: Classical field theory via Cohesive homotopy types

abstract:
  A brief survey of how classical field theory emerges synthetically in
cohesive homotopy type theory. Extended Conference Abstract submitted to the
proceedings of the Conference on Type Theory, Homotopy Theory and Univalent
Foundations in Barcelona, Fall 2013


title: Universal scaling dependence of QCD energy loss from data driven studies

abstract:
  In this paper we study the energy loss of jets in the QGP via the nuclear
modification factor $R_{\textrm{AA}}$ for unidentified particles at high
$p_{\textrm{T}}$ ($\gtrsim 10 \textrm{GeV}/c$) in and out of the reaction plane
of the collision. We argue that at such a high $p_{\textrm{T}}$ there are no
genuine flow effects and, assuming that the energy loss is only sensitive to
initial characteristics such as the density and geometry, find that
$R_{\textrm{AA}}$ depends linearly on the (RMS) length extracted from Glauber
simulations. Furthermore we observe that for different centrality classes the
density dependence of the energy loss enters as the square root of the charged
particle multiplicity normalized to the initial overlap area. The energy loss
extracted for RHIC and LHC data from the $R_{\textrm{AA}}$ is found to exhibit
a universal behavior.


title:
A Generalized Weil Representation for the finite split orthogonal group
  $O_q(2n,2n)$, $q$ odd greater than $3$

abstract:
  We construct via generators and relations a generalized Weil representation
for the split orthogonal group $\ot_q(2n,2n)$ over a finite field of $q$
elements. Besides, we give an initial decomposition of the representation
found. We also show that the constructed representation is equal to the
restriction of the Weil representation to $\ot_q(2n,2n)$ for the reductive dual
pair $(\Sp_2(\mathbb{F}_q),\ot_q(2n,2n))$ and that the initial decomposition is
the same as the decomposition with respect to the action of
$\Sp_2(\mathbb{F}_q)$.


title:
QCD condensates and holographic Wilson loops for asymptotically AdS
  spaces

abstract:
  The minimization of the Nambu-Goto action for a surface whose contour defines
a circular Wilson loop of radius a placed at a finite value of the coordinate
orthogonal to the boundary is considered. This is done for asymptotically AdS
spaces. The condensates of even dimension $n=2$ through $10$ are calculated in
terms of the coefficient of $a^{n}$ in the expansion of the on-shell subtracted
Nambu-Goto action for small $a$
  The subtraction employed is such that it presents no conflict with conformal
invariance in the AdS case and need not introduce an additional infrared scale
for the case of confining geometries. It is shown that the UV value of the
condensates is universal in the sense that they only depends on the first
coefficients of the difference with the AdS case.


title:
Topological genericity of nowhere differentiable functions in the disc
  and polydisc algebras

abstract:
  In this paper we examine functions in the disc algebra $\mathcal{A}(D)$ and
the polydisc algebra $\mathcal{A}(D^I)$, where $I$ is a finite or countably
infinite set. We prove that, generically, for every $f \in \mathcal{A}(D)$ the
continuous periodic functions $u=Ref|_{\mathbb{T}}$ and $\tilde{u} =
Imf|_{\mathbb{T}}$ are nowhere differentiable on the unit circle $\mathbb{T}$.
Afterwards, we generalize this result by proving that, generically, for every
$f \in \mathcal{A}(D^I)$, where $I$ is as above, the continuous periodic
functions $u=Ref|_{\mathbb{T}^I}$ and $\tilde{u} = Imf|_{\mathbb{T}^I}$ have no
directional derivatives at any point of $\mathbb{T}^I$ and every direction $v
\in \mathbb{R}^I$ with $\|v\|_{\infty}=1$.


title:
Diffusion behavior in diluted ($Fe,Cr$) alloys: An environment for H
  diffusion in ferritic steels

abstract:
  Impurity diffusion coefficients are entirely obtained from a low cost
classical molecular statics technique (CMST). In particular, we show how the
CMST is appropriate in order to describe the impurity diffusion behavior
mediated by a vacancy mechanism. In the context of the five-frequency model,
CMST allows to calculate all the microscopic parameters, namely: the free
energy of vacancy formation, the vacancy-solute binding energy and the involved
jump frequencies, from them, we obtain the macroscopic transport magnitudes
such as: correlation factor, solvent-enhancement factor, Onsager and diffusion
coefficients. Also, we report for the first time the behavior of diffusion
coefficients for the solute-vacancy paired specie. We perform our calculations
in diluted NiAl and AlU f.c.c. alloys. Our results are in perfect agreement
with available experimental data for both systems and predict that for NiAl the
solute diffuses through a vacancy interchange mechanism, while for the AlU
system, a vacancy drag mechanism occurs.


title: When are rough surfaces sticky?

abstract:
  At the molecular scale there are strong attractive interactions between
surfaces, yet few macroscopic surfaces are sticky. Extensive simulations of
contact by adhesive surfaces with roughness on nanometer to micrometer scales
are used to determine how roughness reduces the area where atoms contact and
thus weakens adhesion. The material properties, adhesive strength and roughness
parameters are varied by orders of magnitude. In all cases the area of atomic
contact rises linearly with load, and the prefactor rises linearly with
adhesive strength for weak interactions. Above a threshold adhesive strength,
the prefactor changes sign, the surfaces become sticky and a finite force is
required to separate them. A parameter-free analytic theory is presented that
describes changes in these numerical results over up to five orders of
magnitude in load. It relates the threshold strength to roughness and material
properties, explaining why most macroscopic surfaces do not stick. The
numerical results are qualitatively and quantitatively inconsistent with
classical theories based on the Greenwood-Williamson approach that neglect the
range of adhesion and do not include asperity interactions.


title:
A Dissipative-Particle-Dynamics Model for Simulating Dynamics of Charged
  Colloid

abstract:
  A mesoscopic colloid model is developed in which a spherical colloid is
represented by many interacting sites on its surface. The hydrodynamic
interactions with thermal fluctuations are taken accounts in full using
Dissipative Particle Dynamics, and the electrostatic interactions are simulated
using Particle-Particle-Particle Mesh method. This new model is applied to
investigate the electrophoretic mobility of a charged colloid under an external
electric field, and the influence of salt concentration and colloid charge are
systematically studied. The simulation results show good agreement with
predictions from the electrokinetic theory.


title: Catching Shaped Microwave Photons with 99.4% Absorption Efficiency

abstract:
  We demonstrate a high efficiency deterministic quantum receiver to convert
flying qubits to logic qubits. We employ a superconducting resonator, which is
driven with a shaped pulse through an adjustable coupler. For the ideal "time
reversed" shape, we measure absorption and receiver fidelities at the single
microwave photon level of, respectively, 99.41% and 97.4%. These fidelities are
comparable with gates and measurement and exceed the deterministic quantum
communication and computation fault tolerant thresholds.


title:
Toward a New Approach for Modeling Dependability of Data Warehouse
  System

abstract:
  The sustainability of any Data Warehouse System (DWS) is closely correlated
with user satisfaction. Therefore, analysts, designers and developers focused
more on achieving all its functionality, without considering others kinds of
requirement such as dependability s aspects. Moreover, these latter are often
considered as properties of the system that will must be checked and corrected
once the project is completed. The practice of "fix it later" can cause the
obsolescence of the entire Data Warehouse System. Therefore, it requires the
adoption of a methodology that will ensure the integration of aspects of
dependability since the early stages of project DWS. In this paper, we first
define the concepts related to dependability of DWS. Then we present our
approach inspired from the MDA (Model Driven Architecture) approach to model
dependability s aspects namely: availability, reliability, maintainability and
security, taking into account their interaction.


title: Semiclassical partition function for the double-well potential

abstract:
  We compute the partition function and specific heat for a quantum mechanical
particle under the influence of a quartic double-well potential
non-perturbatively, using the semiclassical method. Near the region of bounded
motion in the inverted potential, the usual quadratic approximation fails due
to the existence of multiple classical solutions and caustics. Using the tools
of catastrophe theory, we identify the relevant classical solutions, showing
that at most two have to be considered. This corresponds to the first step
towards the study of spontaneous symmetry breaking and thermal phase
transitions in the non-perturbative framework of the boundary effective theory.


title: Duality, Bridgeland wall-crossing and flips of secant varieties

abstract:
  Let $v_d(\mathbb{P}^2)\subset |\mathcal{O}_{\mathbb{P}^2}(d)|$ denote the
$d$-uple Veronese surface. After studying some general aspects of the
wall-crossing phenomena for stability conditions on surfaces, we are able to
describe a sequence of flips of the secant varieties of $v_d(\mathbb{P}^2)$ by
embedding the blow-up
$\mbox{bl}_{v_d(\mathbb{P}^2)}|\mathcal{O}_{\mathbb{P}^2}(d)|$ into a suitable
moduli space of Bridgeland semistable objects on $\mathbb{P}^2$.


title:
Controlling the stability of periodic orbits of completely integrable
  systems

abstract:
  We provide a constructive method designed in order to control the stability
of a given periodic orbit of a general completely integrable system. The method
consists of a specific type of perturbation, such that the resulting perturbed
system becomes a codimension-one dissipative dynamical system which also admits
that orbit as a periodic orbit, but whose stability can be a-priori prescribed.
The main results are illustrated in the case of a three dimensional dissipative
perturbation of the harmonic oscillator, and respectively Euler's equations
form the free rigid body dynamics.


title: On a question of O'Grady about modified diagonals

abstract:
  Let X be an abelian variety of dimension g. In a recent preprint O'Grady
defines modified diagonal classes \Gamma^m on X^m and he conjectures that the
class of \Gamma^m in the Chow ring of X^m is torsion for m \geq 2g+1. We prove
a generalization of this conjecture.


title: Suppression of ferromagnetism in the La(V$_x$Cr$_{1-x}$)Sb$_3$ system

abstract:
  To explore the possibility of quantum phase transitions and even quantum
criticality in LaCrSb$_3$ based compounds, we performed measurements under
pressure as well as a vanadium substitution study. The Curie temperature of
LaCrSb$_3$ was found to be invariant under pressure. Although pressure was not
able to suppress the ferromagnetism, chemical substitution was used as another
parameter to tune the magnetism. We grew La(V$_x$Cr$_{1-x}$)Sb$_3$ (\textit{x}
= 0 -- 1.0) single crystals, and studied the series by measurements of
temperature and field dependent magnetic susceptibility, magnetization,
resistivity, and specific heat. Ferromagnetism has been observed for $x \leq
0.22$, and the system manifests a strong anisotropy in its ordered state. The
Curie temperature decreases monotonically as the V concentration increases. For
$0.42 \leq x \leq 0.73$, the system enters a new magnetic state at low
temperatures, and no magnetic ordering above 1.8 K can be observed for $x \geq
0.88$. The effective moment $\mu_{\rm eff}$/Cr varies only slightly as the V
concentration increases, from 3.9 $\mu_{\rm B}$ for $x$ = 0 to 2.9 $\mu_{\rm
B}$ for $x$ = 0.88. Features related to quantum criticality have not been
observed in the La(V$_x$Cr$_{1-x}$)Sb$_3$ system.


title: Constrained Codes for Joint Energy and Information Transfer

abstract:
  In various wireless systems, such as sensor RFID networks and body area
networks with implantable devices, the transmitted signals are simultaneously
used both for information transmission and for energy transfer. In order to
satisfy the conflicting requirements on information and energy transfer, this
paper proposes the use of constrained run-length limited (RLL) codes in lieu of
conventional unconstrained (i.e., random-like) capacity-achieving codes. The
receiver's energy utilization requirements are modeled stochastically, and
constraints are imposed on the probabilities of battery underflow and overflow
at the receiver. It is demonstrated that the codewords' structure afforded by
the use of constrained codes enables the transmission strategy to be better
adjusted to the receiver's energy utilization pattern, as compared to classical
unstructured codes. As a result, constrained codes allow a wider range of
trade-offs between the rate of information transmission and the performance of
energy transfer to be achieved.


title:
Spin dynamics and an orbital-antiphase pairing symmetry in iron-based
  superconductors

abstract:
  The symmetry of the wave function describing the Cooper pairs is one of the
most fundamental quantities in a superconductor but its measurement in the
iron-based superconductors has proved to be very difficult. The complex
multi-band nature of these materials makes the interplay of superconductivity
with spin and orbital dynamics very intriguing, leading to very material
dependent magnetic excitations, and pairing symmetries. Here we use
first-principles many-body method, including ab initio determined two-particle
vertex function, to study the spin dynamics and superconducting pairing
symmetry in a large number of iron-based superconductors. In iron compounds
with high transition temperature, we find both the dispersive high-energy spin
excitations, and very strong low energy commensurate or nearly commensurate
spin response, suggesting that these low energy spin excitations play the
dominate role in cooper pairing. We find three closely competing types of
pairing symmetries, which take a very simple form in the space of active iron
$3d$ orbitals, and differ only in the relative quantum mechanical phase of the
$xz$, $yz$ and $xy$ orbital contributions. The extensively discussed s$^{+-}$
symmetry appears when contributions from all orbitals have equal sign, while
the opposite sign in $xz$ and $yz$ orbitals leads to the $d$ wave symmetry. A
novel orbital antiphase $s^{+-}$ symmetry emerges when $xy$ orbital has
opposite sign to $xz$ and $yz$ orbitals. We propose that this orbital-antiphase
pairing symmetry explains the puzzling variation of the experimentally observed
superconducting gaps on all the Fermi surfaces of LiFeAs. This novel symmetry
of the order parameter may be realized in other iron superconductors.

categories: cond-mat.supr-con cond-mat.mtrl-sci cond-mat.str-el physics.comp-ph


title:
Statistical Inference in Hidden Markov Models using $k$-segment
  Constraints

abstract:
  Hidden Markov models (HMMs) are one of the most widely used statistical
methods for analyzing sequence data. However, the reporting of output from HMMs
has largely been restricted to the presentation of the most-probable (MAP)
hidden state sequence, found via the Viterbi algorithm, or the sequence of most
probable marginals using the forward-backward (F-B) algorithm. In this article,
we expand the amount of information we could obtain from the posterior
distribution of an HMM by introducing linear-time dynamic programming
algorithms that, we collectively call $k$-segment algorithms, that allow us to
i) find MAP sequences, ii) compute posterior probabilities and iii) simulate
sample paths conditional on a user specified number of segments, i.e.
contiguous runs in a hidden state, possibly of a particular type. We illustrate
the utility of these methods using simulated and real examples and highlight
the application of prospective and retrospective use of these methods for
fitting HMMs or exploring existing model fits.


title: Mathematical and Physical Ideas for Climate Science

abstract:
  The climate is a forced and dissipative nonlinear system featuring
non-trivial dynamics of a vast range of spatial and temporal scales. The
understanding of the climate's structural and multiscale properties is crucial
for the provision of a unifying picture of its dynamics and for the
implementation of accurate and efficient numerical models. We present some
recent developments at the intersection between climate science, mathematics,
and physics, which may prove fruitful in the direction of constructing a more
comprehensive account of climate dynamics. We describe the Nambu formulation of
fluid dynamics, and the potential of such a theory for constructing
sophisticated numerical models of geophysical fluids. Then, we focus on the
statistical mechanics of quasi-equilibrium flows in a rotating environment,
which seems crucial for constructing a robust theory of geophysical turbulence.
We then discuss ideas and methods suited for approaching directly the
non-equilibrium nature of the climate system. First, we describe some recent
findings on the thermodynamics of climate and characterize its energy and
entropy budgets, and discuss related methods for intercomparing climate models
and for studying tipping points. These ideas can also create a common ground
between geophysics and astrophysics by suggesting general tools for studying
exoplanetary atmospheres. We conclude by focusing on non-equilibrium
statistical mechanics, which allows for a unified framing of problems as
different as the climate response to forcings, the effect of altering the
boundary conditions or the coupling between geophysical flows, and the
derivation of parametrizations for numerical models.

categories: physics.ao-ph astro-ph.EP cond-mat.stat-mech physics.flu-dyn physics.geo-ph


title:
Chiral skyrmions in cubic helimagnet films: the role of uniaxial
  anisotropy

abstract:
  This paper reports on magnetometry and magnetoresistance measurements of MnSi
epilayers performed in out-of-plane magnetic fields. We present a theoretical
analysis of the chiral modulations that arise in confined cubic helimagnets
where the uniaxial anisotropy axis and magnetic field are both out-of-plane. In
contrast to in-plane field measurements (Wilson et al., Phys. Rev. B 86, 144420
(2012)), the hard-axis uniaxial anisotropy in MnSi/Si(111) increases the energy
of (111)-oriented skyrmions and in-plane helicoids relative to the cone phase,
and makes the cone phase the only stable magnetic texture below the saturation
field. While induced uniaxial anisotropy is important in stabilizing skyrmion
lattices and helicoids in other confined cubic helimagnets, the particular
anisotropy in MnSi/Si(111) entirely suppresses these states in an out-of-plane
magnetic field. However, it is predicted that isolated skyrmions with enlarged
sizes exist in MnSi/Si(111) epilayers in a broad range of out-of-plane magnetic
fields.


title:
Integrability in conformally coupled gravity: Taub-NUT spacetimes and
  rotating black holes

abstract:
  We consider four dimensional stationary and axially symmetric spacetimes for
conformally coupled scalar-tensor theories. We show that, in analogy to the
Lewis-Papapetrou problem in General Relativity (GR), the theory at hand can be
recast in an analogous integrable form. We give the relevant rod formalism,
introduced by Weyl for vacuum GR, explicitly giving the rod structure of the
black hole of Bocharova et al. and Bekenstein (BBMB), in complete analogy to
the Schwarzschild solution. The additional scalar field is shown to play the
role of an extra Weyl potential. We then employ the Ernst method as a concrete
solution generating example to obtain the Taub-NUT version of the BBMB hairy
black hole, with or without a cosmological constant. We show that the anti-de
Sitter hyperbolic version of this solution is free of closed timelike curves
that plague usual Taub-NUT metrics, and thus consists of a rotating,
asymptotically locally anti-de Sitter black hole. This stationary solution has
no curvature singularities whatsoever in the conformal frame, and the NUT
charge is shown here to regularize the central curvature singularity of the
corresponding static black hole. Given our findings we discuss the anti-de
Sitter hyperbolic version of Taub-NUT in four dimensions, and show that the
curvature singularity of the NUT-less solution is now replaced by a neighboring
chronological singularity screened by horizons. We argue that the properties of
this rotating black hole are very similar to those of the rotating BTZ black
hole in three dimensions.


title: Noncommutative solenoids and their projective modules

abstract:
  Let p be prime. A noncommutative p-solenoid is the C*-algebra of Z[1/p] x
Z[1/p] twisted by a multiplier of that group, where Z[1/p] is the additive
subgroup of the field Q of rational numbers whose denominators are powers of p.
In this paper, we survey our classification of these C*-algebras up to
*-isomorphism in terms of the multipliers on Z[1/p], using techniques from
noncommutative topology. Our work relies in part on writing these C*-algebras
as direct limits of rotation algebras, i.e. twisted group C*-algebras of the
group Z^2 thereby providing a mean for computing the K-theory of the
noncommutative solenoids, as well as the range of the trace on the K_0 groups.
We also establish a necessary and sufficient condition for the simplicity of
the noncommutative solenoids. Then, using the computation of the trace on K_0,
we discuss two different ways of constructing projective modules over the
noncommutative solenoids.


title: Identifying Purpose Behind Electoral Tweets

abstract:
  Tweets pertaining to a single event, such as a national election, can number
in the hundreds of millions. Automatically analyzing them is beneficial in many
downstream natural language applications such as question answering and
summarization. In this paper, we propose a new task: identifying the purpose
behind electoral tweets--why do people post election-oriented tweets? We show
that identifying purpose is correlated with the related phenomenon of sentiment
and emotion detection, but yet significantly different. Detecting purpose has a
number of applications including detecting the mood of the electorate,
estimating the popularity of policies, identifying key issues of contention,
and predicting the course of events. We create a large dataset of electoral
tweets and annotate a few thousand tweets for purpose. We develop a system that
automatically classifies electoral tweets as per their purpose, obtaining an
accuracy of 43.56% on an 11-class task and an accuracy of 73.91% on a 3-class
task (both accuracies well above the most-frequent-class baseline). Finally, we
show that resources developed for emotion detection are also helpful for
detecting purpose.


title: Performance Modeling of BitTorrent Peer-to-Peer File Sharing Networks

abstract:
  BitTorrent is undoubtedly the most popular P2P file sharing application on
today's Internet. The widespread popularity of BitTorrent has attracted a great
deal of attention from networking researchers who conducted various performance
studies on it. This paper presents a comprehensive survey of analytical
performance modeling techniques for BitTorrent networks. The performance models
examined in this study include deterministic models, Markov chain models, fluid
flow models, and queuing network models. These models evaluate the performance
metrics of BitTorrent networks at different regimes with various realistic
factors considered. Furthermore, a comparative analysis is conducted on those
modeling techniques in the aspects of complexity, accuracy, extensibility, and
scalability.


title: Free monotone transport without a trace

abstract:
  We adapt the free monotone transport results of Guionnet and Shlyakhtenko to
the type $\text{III}$ case. As a direct application, we obtain that the
$q$-deformed Araki-Woods algebras are isomorphic (for sufficiently small
$|q|$).


title:
Software Reuse in Cardiology Related Medical Database Using K-Means
  Clustering Technique

abstract:
  Software technology based on reuse is identified as a process of designing
software for the reuse purpose. The software reuse is a process in which the
existing software is used to build new software. A metric is a quantitative
indicator of an attribute of an item or thing. Reusability is the likelihood
for a segment of source code that can be used again to add new functionalities
with slight or no modification. A lot of research has been projected using
reusability in reducing code, domain, requirements, design etc., but very
little work is reported using software reuse in medical domain. An attempt is
made to bridge the gap in this direction, using the concepts of clustering and
classifying the data based on the distance measures. In this paper cardiologic
database is considered for study. The developed model will be useful for
Doctors or Paramedics to find out the patients level in the cardiologic
disease, deduce the medicines required in seconds and propose them to the
patient. In order to measure the reusability K means clustering algorithm is
used.


title: Discovery of a Highly Variable Dipping Ultraluminous X-ray source in M94

abstract:
  We report the discovery of a new ultraluminous X-ray source (ULX) 2XMM
J125048.6+410743 within the spiral galaxy M94. The source has been observed by
ROSAT, Chandra, and XMM-Newton on several occasions, exhibiting as a highly
variable persistent source or a recurrent transient with a flux variation
factor of >100, a high duty cycle (at least ~70%), and a peak luminosity of Lx
~ 2X10^{39} erg/s (0.2-10 keV, absorbed). In the brightest observation, the
source is similar to typical low-luminosity ULXs, with the spectrum showing a
high-energy cutoff but harder than that from a standard accretion disk. There
are also sporadical short dips, accompanied by spectral softening. In a fainter
observation with Lx ~ 3.6X10^{38} erg/s, the source appears softer and is
probably in the thermal state seen in Galactic black-hole X-ray binaries
(BHBs). In an even fainter observation (Lx ~ 9X10^{37} erg/s), the spectrum is
harder again, and the source might be in the steep-powerlaw state or the hard
state of BHBs. In this observation, the light curve might exhibit ~7 hr
(quasi-)periodic large modulations over two cycles. The source also has a
possible point-like optical counterpart from HST images. In terms of the colors
and the luminosity, the counterpart is probably a G8 supergiant or a compact
red globular cluster containing ~2X10^5 K dwarfs, with some possible weak UV
excess that might be ascribed to accretion activity. Thus our source is a
candidate stellar-mass BHB with a supergiant companion or with a dwarf
companion residing in a globular cluster. Our study supports that some
low-luminosity ULXs are supercritically accreting stellar-mass BHBs.


title:
Important Roles of Te 5p and Ir 5d Spin-orbit Interactions on the
  Multi-band Electronic Structure of Triangular Lattice Superconductor
  Ir1-xPtxTe2

abstract:
  We report an angle-resolved photoemission spectroscopy (ARPES) study on a
triangular lattice superconductor Ir$_{1-x}$Pt$_{x}$Te$_2$ in which the Ir-Ir
or Te-Te bond formation, the band Jahn-Teller effect, and the spin-orbit
interaction are cooperating and competing with one another. The Fermi surfaces
of the substituted system are qualitatively similar to the band structure
calculations for the undistorted IrTe$_2$ with an upward chemical potential
shift due to electron doping. A combination of the ARPES and the band structure
calculations indicates that the Te $5p$ spin-orbit interaction removes the
$p_x/p_y$ orbital degeneracy and induces $p_x \pm ip_y$ type spin-orbit
coupling near the A point. The inner and outer Fermi surfaces are entangled by
the Te $5p$ and Ir $5d$ spin-orbit interactions which may provide exotic
superconductivity with singlet-triplet mixing.


title: Entanglement growth during thermalization in holographic systems

abstract:
  We derive in detail several universal features in the time evolution of
entanglement entropy and other nonlocal observables in quenched holographic
systems. The quenches are such that a spatially uniform density of energy is
injected at an instant in time, exciting a strongly coupled CFT which
eventually equilibrates. Such quench processes are described on the gravity
side by the gravitational collapse of a thin shell that results in a black
hole. Various nonlocal observables have a unified description in terms of the
area of extremal surfaces of different dimensions. In the large distance limit,
the evolution of an extremal surface, and thus the corresponding boundary
observable, is controlled by the geometry around and inside the event horizon
of the black hole, allowing us to identify regimes of pre-local- equilibration
quadratic growth, post-local-equilibration linear growth, a memory loss regime,
and a saturation regime with behavior resembling those in phase transitions. We
also discuss possible bounds on the maximal rate of entanglement growth in
relativistic systems.

categories: hep-th cond-mat.stat-mech cond-mat.str-el quant-ph


title: Detectability of Free Floating Planets in Open Clusters with JWST

abstract:
  Recent observations have shown the presence of extra-solar planets in
Galactic open stellar clusters, as in the Praesepe (M44). These systems provide
a favorable environment for planetary formation due to the high heavy-element
content exhibited by the majority of their population. The large stellar
density, and corresponding high close-encounter event rate, may induce strong
perturbations of planetary orbits with large semimajor axes. Here we present a
set of N-body simulations implementing a novel scheme to treat the tidal
effects of external stellar perturbers on planetary orbit eccentricity and
inclination. By simulating five nearby open clusters we determine the rate of
occurrence of bodies extracted from their parent stellar system by
quasi-impulsive tidal interactions. We find that the specific free-floating
planet production rate (total number of free-floating planets per unit of time,
normalized by the total number of stars) is proportional to the stellar density
of the cluster, with a constant of proportionality equal to (23 +/- 5)10^-6
pc^3 Myr^-1. For the Pleiades (M45) we predict that about 26% of stars should
have lost their planets. This raises the exciting possibility of directly
observing these wandering planets with the James Webb Space Telescope in the
NIR band. Assuming a surface temperature of the planet of 500 K, a
free-floating planet of Jupiter size inside the Pleiades would have a specific
flux @4.4 micron of approximately 400 nJy, which would lead to a very clear
detection (S/N of order 100) in only one hour of integration.


title:
Modeling Tracers of Young Stellar Population Age in Star-Forming
  Galaxies

abstract:
  The young stellar population of a star-forming galaxy is the primary engine
driving its radiative properties. As a result, the age of a galaxy's youngest
generation of stars is critical for a detailed understanding of its star
formation history, stellar content, and evolutionary state. Here we present
predicted equivalent widths for the H-beta, H-alpha, and Br-gamma recombination
lines as a function of stellar population age. The equivalent widths are
produced by the latest generations of stellar evolutionary tracks and the
Starburst99 stellar population synthesis code, and are the first to fully
account for the combined effects of both nebular emission and continuum
absorption produced by the synthetic stellar population. Our grid of model
stellar populations spans six metallicities (0.001 < Z < 0.04), two treatments
of star formation history (a 10^6 Mo instantaneous burst and a continuous star
formation rate of 1 Mo/yr), and two different treatments of initial rotation
rate (v_rot = 0.0v_crit and 0.4v_crit). We also investigate the effects of
varying the initial mass function. Given constraints on galaxy metallicity, our
predicted equivalent widths can be applied to observations of star-forming
galaxies to approximate the age of their young stellar populations.


title: On the Metallicities of Kepler Stars

abstract:
  We use 12000 stars from Large Sky Area Multi-Object Fiber Spectroscopic
Telescope (LAMOST) spectroscopic data to show that the metallicities of Kepler
field stars as given in the Kepler Input Catalog (KIC) systematically
underestimate both the true metallicity and the dynamic range of the Kepler
sample. Specifically, to the first order approximation, we find [Fe/H]_KIC =
-0.20 + 0.43 [Fe/H]_LAMOST, with a scatter of ~0.25 dex, due almost entirely to
errors in KIC. This relation is most secure for -0.3<[Fe/H]_LAMOST<+0.4 where
we have >200 comparison stars per 0.1 dex bin and good consistency is shown
between metallicities determined by LAMOST and high-resolution spectra. It
remains approximately valid in a slightly broader range. When the relation is
inverted, the error in true metallicity as derived from KIC is (0.25
dex)/0.43~0.6 dex. We thereby quantitatively confirm the cautionary note by
Brown et al. (2011) that KIC estimates of [Fe/H] should not be used by "anyone
with a particular interest in stellar metallicities". Fortunately, many more
LAMOST spectroscopic metallicities will be available in the near future.


title: Dyonic AdS black holes in maximal gauged supergravity

abstract:
  We present two new classes of dyonic anti-de Sitter black hole solutions of
4-dimensional maximal N=8, SO(8) gauged supergravity. They are: (1) static
black holes of N=2, U(1)^4 gauged supergravity with 4 electric and 4 magnetic
charges, with spherical, planar or hyperbolic horizons; and (2) rotating black
holes of N=2, U(1)^2 gauged supergravity with 2 electric and 2 magnetic
charges. We study their thermodynamics, and point out that the formulation of a
consistent thermodynamics for dyonic anti-de Sitter black holes is dependent on
the existence of boundary conditions for the gauge fields. We identify several
distinct classes of boundary conditions for gauge fields in U(1)^4
supergravity. We study a general family of metrics containing the rotating
solutions, and find Killing-Yano tensors with torsion in two conformal frames,
which underlie separability.


title:
Mass and Concentration estimates from Weak and Strong Gravitational
  Lensing: a Systematic Study

abstract:
  We study how well halo properties of galaxy clusters, like mass and
concentration, are recovered using lensing data. In order to generate a large
sample of systems at different redshifts we use the code MOKA. We measure halo
mass and concentration using weak lensing data alone (WL), fitting to an NFW
profile the reduced tangential shear profile, or by combining weak and strong
lensing data, by adding information about the size of the Einstein radius
(WL+SL). For different redshifts, we measure the mass and the concentration
biases and find that these are mainly caused by the random orientation of the
halo ellipsoid with respect to the line-of-sight. Since our simulations account
for the presence of a bright central galaxy, we perform mass and concentration
measurements using a generalized NFW profile which allows for a free inner
slope. This reduces both the mass and the concentration biases. We discuss how
the mass function and the concentration mass relation change when using WL and
WL+SL estimates. We investigate how selection effects impact the measured
concentration-mass relation showing that strong lens clusters may have a
concentration 20-30% higher than the average, at fixed mass, considering also
the particular case of strong lensing selected samples of relaxed clusters.
Finally, we notice that selecting a sample of relaxed galaxy clusters, as is
done in some cluster surveys, explain the concentration-mass relation biases.


title:
Galaxy Evolution: Modeling the Role of Non-thermal Pressure in the
  Interstellar medium

abstract:
  Galaxy evolution depends strongly on the physics of the interstellar medium
(ISM). Motivated by the need to incorporate the properties of the ISM in
cosmological simulations we construct a simple method to include the
contribution of non-thermal components in the calculation of pressure of
interstellar gas. In our method we treat three non-thermal components -
turbulence, magnetic fields and cosmic rays - and effectively parametrize their
amplitude. We assume that the three components settle into a quasi-steady-state
that is governed by the star formation rate, and calibrate their magnitude and
density dependence by the observed Radio-FIR correlation, relating synchrotron
radiation to star formation rates of galaxies. We implement our model in single
cell numerical simulation of a parcel of gas with constant pressure boundary
conditions and demonstrate its effect and potential. Then, the non-thermal
pressure model is incorporated into RAMSES and hydrodynamic simulations of
isolated galaxies with and without the non-thermal pressure model are presented
and studied. Specifically, we demonstrate that the inclusion of realistic
non-thermal pressure reduces the star formation rate by an order of magnitude
and increases the gas depletion time by as much. We conclude that the
non-thermal pressure can prolong the star formation epoch and achieve
consistency with observations without invoking artificially strong stellar
feedback.


title:
Predictions for Shepherding Planets in Scattered Light Images of Debris
  Disks

abstract:
  Planets can affect debris disk structure by creating gaps, sharp edges,
warps, and other potentially observable signatures. However, there is currently
no simple way for observers to deduce a disk-shepherding planet's properties
from the observed features of the disk. Here we present a single equation that
relates a shepherding planet's maximum mass to the debris ring's observed width
in scattered light, along with a procedure to estimate the planet's
eccentricity and minimum semimajor axis. We accomplish this by performing
dynamical N-body simulations of model systems containing a star, a single
planet, and a disk of parent bodies and dust grains to determine the resulting
debris disk properties over a wide range of input parameters. We find that the
relationship between planet mass and debris disk width is linear, with
increasing planet mass producing broader debris rings. We apply our methods to
five imaged debris rings to constrain the putative planet masses and orbits in
each system. Observers can use our empirically-derived equation as a guide for
future direct imaging searches for planets in debris disk systems. In the
fortuitous case of an imaged planet orbiting interior to an imaged disk, the
planet's maximum mass can be estimated independent of atmospheric models.


title: The isotropy problem of Sub-ankle Ultra-high energy cosmic rays

abstract:
  We study the time dependent propagation of sub-ankle ultra-high energy cosmic
rays (UHECRs) originating from point-like Galactic sources. We show that drift
in the Galactic magnetic field (GMF) may play an important role in the
propagation of UHECRs and their measured anisotropy, particularly when the
transport is anisotropic. To fully account for the discreteness of UHECR
sources in space and time, a Monte Carlo method is used to randomly place
sources in the Galaxy. The low anisotropy measured by Auger is not generally
characteristic of the theoretical models, given that the sources are
distributed in proportion to the star formation rate, but it can possibly be
understood as a) intermittency effects due to the discrete nature of the
sources or, with extreme parameters, b) a cancellation of drift current along a
current sheet with the outward radial diffusive flux. We conclude that it is
possible to interpret the Galactic sub-ankle CR flux as being due entirely to
intermittent discrete Galactic sources distributed in proportion to star
formation, but only with probability of roughly 35 percent, of which the
spectrum is in accord with observations about 30 percent of the time.
  An alternative explanation for the low anisotropy may be that they are mostly
extragalactic and/or heavy.


title: Early Hydrodynamic Evolution of a Stellar Collision

abstract:
  The early phase of the hydrodynamic evolution following collision of two
stars is analyzed. Two strong shocks propagate at a constant velocity (which is
a small fraction of the velocity of the approaching stars) from the contact
surface toward the center of each star. The shocked region near the contact
surface has a planar symmetry and a uniform pressure. The density vanishes at
the (Lagrangian) surface of contact and the speed of sound diverges there. The
temperature, however, reaches a finite value, since as the density vanishes,
the finite pressure is radiation dominated. For Carbon-Oxygen white dwarfs
collisions this temperature is too low for any appreciable nuclear burning at
early times. The divergence of the speed of sound limits numerical studies of
stellar collisions, as it makes convergence tests exceedingly expensive unless
dedicated schemes are used. We provide a new one-dimensional Lagrangian
numerical scheme to achieve this. Self-similar planar solutions are derived for
zero-impact parameter collisions between two identical stars, under some
simplifying assumptions. These solutions provide rough approximations that
capture the main features of the flow and allow a general study as well as a
detailed numerical verification test problem. The self-similar solution in the
upstream frame is the planar version of previous piston problems that were
studied in cylindrical and spherical symmetries. We found it timely to present
a global picture of self similar piston problems. In particular, we derive new
results regarding the non trivial transition to accelerating shocks at
sufficiently declining densities (not relevant for collisions).


title:
Mass, velocity anisotropy, and pseudo phase-space density profiles of
  Abell 2142

abstract:
  Aim: We aim to compute the mass and velocity anisotropy profiles of Abell
2142 and, from there, the pseudo phase--space density profile $Q(r)$ and the
density slope - velocity anisotropy $\beta - \gamma$ relation, and then to
compare them with theoretical expectations. Methods: The mass profiles were
obtained by using three techniques based on member galaxy kinematics, namely
the caustic method, the method of Dispersion - Kurtosis, and MAMPOSSt. Through
the inversion of the Jeans equation, it was possible to compute the velocity
anisotropy profiles. Results: The mass profiles, as well as the virial values
of mass and radius, computed with the different techniques agree with one
another and with the estimates coming from X-ray and weak lensing studies. A
concordance mass profile is obtained by averaging the lensing, X-ray, and
kinematics determinations. The cluster mass profile is well fitted by an NFW
profile with $c=4.0 \pm 0.5$. The population of red and blue galaxies appear to
have a different velocity anisotropy configuration, since red galaxies are
almost isotropic, while blue galaxies are radially anisotropic, with a weak
dependence on radius. The $Q(r)$ profile for the red galaxy population agrees
with the theoretical results found in cosmological simulations, suggesting that
any bias, relative to the dark matter particles, in velocity dispersion of the
red component is independent of radius. The $\beta - \gamma$ relation for red
galaxies matches the theoretical relation only in the inner region. The
deviations might be due to the use of galaxies as tracers of the gravitational
potential, unlike the non--collisional tracer used in the theoretical relation.


title:
Galaxy And Mass Assembly (GAMA): The large scale structure of galaxies
  and comparison to mock universes

abstract:
  From a volume limited sample of 45,542 galaxies and 6,000 groups with $z \leq
0.213$ we use an adapted minimal spanning tree algorithm to identify and
classify large scale structures within the Galaxy and Mass Assembly (GAMA)
survey. Using galaxy groups, we identify 643 filaments across the three
equatorial GAMA fields that span up to 200 $h^{-1}$ Mpc in length, each with an
average of 8 groups within them. By analysing galaxies not belonging to groups
we identify a secondary population of smaller coherent structures composed
entirely of galaxies, dubbed `tendrils' that appear to link filaments together,
or penetrate into voids, generally measuring around 10 $h^{-1}$ Mpc in length
and containing on average 6 galaxies. Finally we are also able to identify a
population of isolated void galaxies. By running this algorithm on GAMA mock
galaxy catalogues we compare the characteristics of large scale structure
between observed and mock data; finding that mock filaments reproduce observed
ones extremely well. This provides a probe of higher order distribution
statistics not captured by the popularly used two-point correlation function.


title:
Cosmology with massive neutrinos II: on the universality of the halo
  mass function and bias

abstract:
  We use a large suite of N-body simulations to study departures from
universality in halo abundances and clustering in cosmologies with
non-vanishing neutrino masses. To this end, we study how the halo mass function
and halo bias factors depend on the scaling variable $\sigma^2(M,z)$, the
variance of the initial matter fluctuation field, rather than on halo mass $M$
and redshift $z$ themselves. We show that using the variance of the cold dark
matter rather than the total mass field, i.e., $\sigma^2_{cdm}(M,z)$ rather
than $\sigma^2_{m}(M,z)$, yields more universal results. Analysis of halo bias
yields similar conclusions: When large-scale halo bias is defined with respect
to the cold dark matter power spectrum, the result is both more universal, and
less scale- or $k$-dependent. These results are used extensively in Papers I
and III of this series.


title: A Big Data Approach to Computational Creativity

abstract:
  Computational creativity is an emerging branch of artificial intelligence
that places computers in the center of the creative process. Broadly,
creativity involves a generative step to produce many ideas and a selective
step to determine the ones that are the best. Many previous attempts at
computational creativity, however, have not been able to achieve a valid
selective step. This work shows how bringing data sources from the creative
domain and from hedonic psychophysics together with big data analytics
techniques can overcome this shortcoming to yield a system that can produce
novel and high-quality creative artifacts. Our data-driven approach is
demonstrated through a computational creativity system for culinary recipes and
menus we developed and deployed, which can operate either autonomously or
semi-autonomously with human interaction. We also comment on the volume,
velocity, variety, and veracity of data in computational creativity.


title:
Secular chaos and its application to Mercury, hot Jupiters, and the
  organization of planetary systems

abstract:
  In the inner solar system, the planets' orbits evolve chaotically, driven
primarily by secular chaos. Mercury has a particularly chaotic orbit, and is in
danger of being lost within a few billion years. Just as secular chaos is
reorganizing the solar system today, so it has likely helped organize it in the
past. We suggest that extrasolar planetary systems are also organized to a
large extent by secular chaos. A hot Jupiter could be the end state of a
secularly chaotic planetary system reminiscent of the solar system. But in the
case of the hot Jupiter, the innermost planet was Jupiter- (rather than
Mercury-) sized, and its chaotic evolution was terminated when it was tidally
captured by its star. In this contribution, we review our recent work
elucidating the physics of secular chaos and applying it to Mercury and to hot
Jupiters. We also present new results comparing the inclinations of hot
Jupiters thus produced with observations.


title: Counterrotating Stars in Simulated Galaxy Disks

abstract:
  Counterrotating stars in disk galaxies are a puzzling dynamical feature whose
origin has been ascribed to either satellite accretion events or to disk
instabilities triggered by deviations from axisymmetry. We use a cosmological
simulation of the formation of a disk galaxy to show that counterrotating
stellar disk components may arise naturally in hierarchically-clustering
scenarios even in the absence of merging. The simulated disk galaxy consists of
two coplanar, overlapping stellar components with opposite spins: an inner
counterrotating bar-like structure made up mostly of old stars surrounded by an
extended, rotationally-supported disk of younger stars. The opposite-spin
components originate from material accreted from two distinct filamentary
structures which at turn around, when their net spin is acquired, intersect
delineating a "V"-like structure. Each filament torques the other in opposite
directions; the filament that first drains into the galaxy forms the inner
counterrotating bar, while material accreted from the other filament forms the
outer disk. Mergers do not play a substantial role and most stars in the galaxy
are formed in situ; only 9% of all stars are contributed by accretion events.
The formation scenario we describe here implies a significant age difference
between the co- and counterrotating components, which may be used to
discriminate between competing scenarios for the origin of counterrotating
stars in disk galaxies.


title:
Constraining the magnetic field in GRB relativistic collisionless shocks
  using radio data

abstract:
  Using GRB radio afterglow observations, we calculate the fraction of shocked
plasma energy in the magnetic field in relativistic collisionless shocks
($\epsilon_B$). We obtained $\epsilon_B$ for 38 bursts by assuming that the
radio afterglow light curve originates in the external forward shock and that
its peak at a few to tens of days is due to the passage of the minimum
(injection) frequency through the radio band. This allows for the determination
of the peak synchrotron flux of the external forward shock, $f_p$, which is
$f_p \propto \epsilon_B^{1/2}$. The obtained value of $\epsilon_B$ is
conservatively a minimum if the time of the "jet break" is unknown, since after
the "jet break" $f_p$ is expected to decay with time faster than before it.
Claims of "jet breaks" have been made for a subsample of 23 bursts, for which
we can estimate a measurement of $\epsilon_B$. Our results depend on the blast
wave total energy, $E$, and the density of the circum-stellar medium (CSM),
$n$, as $\epsilon_B \propto E^{-2}n^{-1}$. However, by assuming a CSM magnetic
field ($\sim 10$ $\mu$G), we can express the lower limits/measurements on
$\epsilon_B$ as a density-independent ratio, $B/B_{sc}$, of the magnetic field
behind the shock to the CSM shock-compressed magnetic field. We find that the
distribution on both the lower limit on and the measurement of $B/B_{sc}$ spans
$\sim 3.5$ orders of magnitude and both have a median of $B/B_{sc} \sim 30$.
This suggests that some amplification, beyond simple shock-compression, is
necessary to explain these radio afterglow observations.


title: Holographic entanglement entropy of semi-local quantum liquids

abstract:
  We consider the holographic entanglement entropy of $(d+2)$-dimensional
semi-local quantum liquids, for which the dual gravity background in the deep
interior is $AdS_{2}\times\mathbb{R}^{d}$ multiplied by a warp factor which
depends on the radial coordinate. The entropy density of this geometry goes to
zero in the extremal limit. The thermodynamics associated with this semi-local
background is discussed via dimensional analysis and scaling arguments. For the
case of an asymptotically AdS UV completion of this geometry, we show that the
entanglement entropy of a strip and an annulus exhibits a phase transition as a
typical length of the different shapes is varied, while there is no sign of
such a transition for the entanglement entropy of a sphere. Moreover, for the
spherical entangling region, the leading order contribution to the entanglement
entropy in the IR is calculated analytically. It exhibits an area law behaviour
and agrees with the numerical result.


title: Renyi entropies of free bosons on the torus and holography

abstract:
  We analytically evaluate the Renyi entropies for the two dimensional free
boson CFT. The CFT is considered to be compactified on a circle and at finite
temperature. The Renyi entropies S_n are evaluated for a single interval using
the two point function of bosonic twist fields on a torus. For the case of the
compact boson, the sum over the classical saddle points results in the
Riemann-Siegel theta function associated with the A_{n-1} lattice. We then
study the Renyi entropies in the decompactification regime. We show that in the
limit when the size of the interval becomes the size of the spatial circle, the
entanglement entropy reduces to the thermal entropy of free bosons on a circle.
We then set up a systematic high temperature expansion of the Renyi entropies
and evaluate the finite size corrections for free bosons. Finally we compare
these finite size corrections both for the free boson CFT and the free fermion
CFT with the one-loop corrections obtained from bulk three dimensional
handlebody spacetimes which have higher genus Riemann surfaces as its boundary.
One-loop corrections in these geometries are entirely determined by quantum
numbers of the excitations present in the bulk. This implies that the leading
finite size corrections contributions from one-loop determinants of the
Chern-Simons gauge field and the Dirac field in the dual geometry should
reproduce that of the free boson and the free fermion CFT respectively. By
evaluating these corrections both in the bulk and in the CFT explicitly we show
that this expectation is indeed true.


title: Causal Patch Complementarity: The Inside Story for Old Black Holes

abstract:
  We carefully analyze the causal patches which belong to observers falling
into an old black hole. We show that without a distillation-like process, the
AMPS paradox cannot challenge complementarity. That is because the two
ingredients for the paradox, the interior region and the early Hawking
radiation, cannot be space-like separated and both low-energy within any single
causal patch. Either the early quanta have Planckian wavelengths, or the
interior region is exponentially smaller than the Schwarzschild size. This
means that their appearances in the low-energy theory are strictly time-like
separated, which nullifies the problem of double entanglement/purity or quantum
cloning. This verifies that the AMPS paradox is either only a paradox in the
global description like the original information paradox, or a direct
consequence of the assumption that a distillation process is feasible without
hidden consequences. We discuss possible relations to cosmological causal
patches and the possibility to transfer energy without transferring quantum
information.


title: Complex-projective and lens product spaces

abstract:
  Let $t$ be a positive integer. Following work of D. M. Davis, we study the
topology of complex-projective product spaces, i.e. quotients of cartesian
products of odd dimensional spheres by the diagonal $S^1$-action, and of the
$t$-torsion lens product spaces, i.e. the corresponding quotients when the
action is restricted to the $t^{\mathrm{th}}$ roots of unity. For a commutative
complex-oriented cohomology theory $h^*$, we determine the $h^*$-cohomology
ring of these spaces (in terms of the $t$-series for $h^*$, in the case of
$t$-torsion lens product spaces). When $h^*$ is singular cohomology with mod 2
coefficients, we also determine the action of the Steenrod algebra. We show
that these spaces break apart after a suspension as a wedge of desuspensions of
usual stunted complex projective ($t$-torsion lens) spaces. We estimate the
category and topological complexity of complex-projective and lens product
spaces, showing in particular that these invariants are usually much lower than
predicted by the usual dimensional bounds. We extend Davis' analysis of
manifold properties such as immersion dimension, (stable-)span, and
(stable-)parallelizability of real projective product spaces to the
complex-projective and lens product cases.


title:
Finding the First Cosmic Explosions. III. Pulsational Pair-Instability
  Supernovae

abstract:
  Population III supernovae have been the focus of growing attention because of
their potential to directly probe the properties of the first stars,
particularly the most energetic events that can be seen at the edge of the
observable universe. But until now pair-pulsation supernovae, in which
explosive thermonuclear burning in massive stars fails to unbind them but can
eject their outer layers into space, have been overlooked as cosmic beacons at
the earliest redshifts. These shells can later collide and, like Type IIn
supernovae, produce superluminous events in the UV at high redshifts that could
be detected in the near infrared today. We present numerical simulations of a
110 M$_{\odot}$ pair-pulsation explosion done with the Los Alamos radiation
hydrodynamics code RAGE. We find that collisions between consecutive pair
pulsations are visible in the near infrared out to z $\sim$ 15 - 20 and can
probe the earliest stellar populations at cosmic dawn.


title:
A Census of X-ray gas in NGC 1068: Results from 450ks of Chandra HETG
  Observation

abstract:
  We present models for the X-ray spectrum of the Seyfert 2 galaxy NGC 1068.
These are fitted to data obtained using the High Energy Transmission Grating
(HETG) on the Chandra X-ray observatory. The data show line and radiative
recombination continuum (RRC) emission from a broad range of ions and elements.
The models explore the importance of excitation processes for these lines
including photoionization followed by recombination, radiative excitation by
absorption of continuum radiation and inner shell fluorescence. The models show
that the relative importance of these processes depends on the conditions in
the emitting gas, and that no single emitting component can fit the entire
spectrum. In particular, the relative importance of radiative excitation and
photoionization/recombination differs according to the element and ion stage
emitting the line. This in turn implies a diversity of values for the
ionization parameter of the various components of gas responsible for the
emission, ranging from log(xi)=1 -- 3. Using this, we obtain an estimate for
the total amount of gas responsible for the observed emission. The mass flux
through the region included in the HETG extraction region is approximately 0.3
Msun/yr assuming ordered flow at the speed characterizing the line widths. This
can be compared with what is known about this object from other techniques.


title: Quality Assessment of Pixel-Level ImageFusion Using Fuzzy Logic

abstract:
  Image fusion is to reduce uncertainty and minimize redundancy in the output
while maximizing relevant information from two or more images of a scene into a
single composite image that is more informative and is more suitable for visual
perception or processing tasks like medical imaging, remote sensing, concealed
weapon detection, weather forecasting, biometrics etc. Image fusion combines
registered images to produce a high quality fused image with spatial and
spectral information. The fused image with more information will improve the
performance of image analysis algorithms used in different applications. In
this paper, we proposed a fuzzy logic method to fuse images from different
sensors, in order to enhance the quality and compared proposed method with two
other methods i.e. image fusion using wavelet transform and weighted average
discrete wavelet transform based image fusion using genetic algorithm (here
onwards abbreviated as GA) along with quality evaluation parameters image
quality index (IQI), mutual information measure (MIM), root mean square error
(RMSE), peak signal to noise ratio (PSNR), fusion factor (FF), fusion symmetry
(FS) and fusion index (FI) and entropy. The results obtained from proposed
fuzzy based image fusion approach improves quality of fused image as compared
to earlier reported methods, wavelet transform based image fusion and weighted
average discrete wavelet transform based image fusion using genetic algorithm.


title:
Efficient time integration methods based on operator splitting and
  application to the Westervelt equation

abstract:
  Efficient time integration methods based on operator splitting are introduced
for the Westervelt equation, a nonlinear damped wave equation that arises in
nonlinear acoustics as mathematical model for the propagation of sound waves in
high intensity ultrasound applications. For the first-order Lie-Trotter
splitting method a global error estimate is deduced, confirming that the
splitting method remains stable and that the nonstiff convergence order is
retained in situations where the problem data are sufficiently regular.
Fundamental ingredients in the stability and error analysis are regularity
results for the Westervelt equation and related linear evolution equations of
hyperbolic and parabolic type. Numerical examples illustrate and complement the
theoretical investigations.


title: Angular momentum loss of primordial gas in Lyman-alpha radiation field

abstract:
  We present results on the radiation drag exerted by an isotropic and
homogenous background of Lya photons on neutral gas clouds orbiting within HII
regions around Population III stars of different masses. The Doppler shift
causes a frequency difference between photons moving in the direction of the
cloud and opposite to it resulting in a net momentum loss of the cloud in the
direction of motion. We find that half of the angular momentum of gas with
v_theta <~ 20 km/s near (r <~ 3 kpc) a Population III star of 120 Msun at z=20
is lost within ~ 10^6 yr. The radiation drag is a strong function of cloud
velocity that peaks at v ~ 20 km/s reflecting the frequency dependence of the
photon cross section. Clouds moving with velocities larger than ~ 100 km/s
loose their angular momentum on time scales of ~ 10^8 yr. At lower redshifts
radiation drag becomes inefficient as the Lya photon density in HII regions
decreases by a factor (1+z)^3 and angular momentum is lost on time scales >
10^8 yr even for low velocity clouds. Our results suggest that a sweet spot
exists for the loss of angular momentum by radiation drag for gas clouds at z >
10 and with v ~ 20 km/s. Comparison to dynamical friction forces acting on
typical gas clouds suggest that radiation drag is the dominant effect impacting
the orbit. We propose that this effect can suppress the formation of extended
gas discs in the first galaxies and help gas accretion near galactic centres
and central black holes.


title: Locally Monge-Ampere Foliations

abstract:
  It is shown that codimension one parabolic foliations of complex manifolds
are holomorphic. This is proved using the fact that codimension one foliations
of complex manifolds are necessarily locally Monge-Amp\`ere foliations and that
parabolic leaves cannot have hyperbolic behavior. The result holds true also
for locally Monge-Amp\`ere foliations with parabolic leaves of arbitrary
codimension.


title:
A 1500 deg$^2$ Near Infrared Proper Motion Catalogue from the UKIDSS
  Large Area Survey

abstract:
  The UKIDSS Large Area Survey (LAS) began in 2005, with the start of the
UKIDSS program as a 7 year effort to survey roughly 4000 deg$^2$ at high
galactic latitudes in Y, J, H and K bands. The survey also included a
significant quantity of 2-epoch J band observations, with an epoch baseline
greater than 2 years to calculate proper motions. We present a near infrared
proper motion catalogue for the 1500 deg$^2$ of the 2 epoch LAS data, which
includes 135,625 stellar sources and a further 88,324 with ambiguous
morphological classifications, all with motions detected above the 5$\sigma$
level. We developed a custom proper motion pipeline which we describe here. Our
catalogue agrees well with the proper motion data supplied for a 300 deg$^2$
subset in the current WFCAM Science Archive (WSA) tenth data release (DR10)
catalogue, and in various optical catalogues, but it benefits from a larger
matching radius and hence a larger upper proper motion detection limit. We
provide absolute proper motions, using LAS galaxies for the relative to
absolute correction. By using local 2nd order polynomial transformations, as
opposed to linear transformations in the WSA, we correct better for any local
distortions in the focal plane, not including the radial distortion that is
removed by the UKIDSS pipeline. We present the results of proper motion
searches for new brown dwarfs and white dwarfs. We discuss 41 sources in the
WSA DR10 overlap with our catalogue with proper motions $>$300 $mas yr^{-1}$,
several of which are new detections. We present 15 new candidate ultra-cool
dwarf binary systems.


title:
The Atomic and Molecular Content of Disks Around Very Low-mass Stars and
  Brown Dwarfs

abstract:
  There is growing observational evidence that disk evolution is stellar-mass
dependent. Here, we show that these dependencies extend to the atomic and
molecular content of disk atmospheres. We analyze a unique dataset of
high-resolution Spitzer/IRS spectra from 8 very low-mass star and brown dwarf
disks. We report the first detections of Ne+, H2, CO2, and tentative detections
of H2O toward these faint and low-mass disks. Two of our [NeII] 12.81 micron
emission lines likely trace the hot (>5,000 K) disk surface irradiated by X-ray
photons from the central stellar/sub-stellar object. The H2 S(2) and S(1)
fluxes are consistent with arising below the fully or partially ionized surface
traced by the [NeII] emission, in gas at about 600 K. We confirm the higher
C2H2/HCN flux and column density ratio in brown dwarf disks previously noted
from low-resolution IRS spectra. Our high-resolution spectra also show that the
HCN/H2O fluxes of brown dwarf disks are on average higher than those of T Tauri
disks. Our LTE modeling hints that this difference extends to column density
ratios if H2O lines trace warm > 600 K disk gas. These trends suggest that the
inner regions of brown dwarf disks have a lower O/C ratio than those of T Tauri
disks which may result from a more efficient formation of non-migrating icy
planetesimals. A O/C=1, as inferred from our analysis, would have profound
implications on the bulk composition of rocky planets that can form around very
low-mass stars and brown dwarfs.


title:
ProMC: Input-output data format for HEP applications using varint
  encoding

abstract:
  A new data format for Monte Carlo (MC) events, or any structural data,
including experimental data, is discussed. The format is designed to store data
in a compact binary form using variable-size integer encoding as implemented in
the Google's Protocol Buffers package. This approach is implemented in the
ProMC library which produces smaller file sizes for MC records compared to the
existing input-output libraries used in high-energy physics (HEP). Other
important features of the proposed format are a separation of abstract data
layouts from concrete programming implementations, self-description and random
access. Data stored in ProMC files can be written, read and manipulated in a
number of programming languages, such C++, JAVA, FORTRAN and PYTHON.


title: Lorentz estimates for obstacle parabolic problems

abstract:
  We prove that the spatial gradient of (variational) solutions to parabolic
obstacle problems of p-Laplacian type enjoys the same regularity of the data
and of the derivatives of the obstacle in the scale of Lorentz spaces.


title:
Quantum spin ices and topological phases from dipolar-octupolar doublets
  on the pyrochlore lattice

abstract:
  We consider a class of d- and f-electron systems in which dipolar-octupolar
Kramers doublets arise on the sites of the pyrochlore lattice. For such
doublets, two components of the pseudospin transform like a magnetic dipole,
while the other transforms like a component of the magnetic octupole tensor.
Based on a symmetry analysis, we construct and study models of
dipolar-octupolar doublets in itinerant and localized limits. In both limits,
the resulting models are of surprisingly simple form. In the itinerant limit,
we find topological insulating behavior. In the localized limit, the most
general nearest-neighbor spin model is the XYZ model. We show that this XYZ
model exhibits two distinct quantum spin ice (QSI) phases, that we dub dipolar
QSI, and octupolar QSI. We conclude with a discussion of potential relevance to
real material systems.


title:
NLO QCD corrections to $pp\rightarrow e^+\nu_e\mu^+\nu_\mu jj$ in
  vector-boson fusion at the LHC

abstract:
  We report on studies of next-to-leading order (NLO) QCD corrections to the
process $pp\rightarrow e^+\nu_e\mu^+\nu_\mu jj$ which is associated with
vector-boson fusion (VBF) production of an intermediate $W^+W^+$ pair. The
impact of s-channel diagrams and interference contributions in VBF kinematics
is analyzed at leading order (LO) and found to be entirely negligible. The NLO
corrections are around 5% of the LO cross section, and the scale dependence is
reduced to about ~1%. We introduce a dynamic scale which improves the K factor
in the high-energy tails of the distributions.


title:
Finite-key analysis of high-dimensional time-energy entanglement-based
  quantum key distribution

abstract:
  We present a security analysis against collective attacks for the recently
proposed time-energy entanglement-based quantum key distribution protocol,
given the practical constraints of single photon detector efficiency, channel
loss, and finite-key considerations. We find a positive secure-key capacity
when the key length increases beyond $10^4$ for eight-dimensional systems. The
minimum key length required is reduced by the ability to post-select on
coincident single-photon detection events. Including finite-key effects, we
show the ability to establish a shared secret key over a 200 km fiber link.


title: Dissipation in ultrahigh quality factor SiN membrane resonators

abstract:
  We study the optomechanical properties of stoichiometric SiN resonators
through a combination of spectroscopic and interferometric imaging techniques.
At room temperature, we demonstrate ultrahigh quality factors of $5 \times
10^7$ and a $f \times Q$ product of $1 \times 10^{14}$ Hz that, to our
knowledge, correspond to the largest values yet reported for mesoscopic
flexural resonators. Through a comprehensive study of the limiting dissipation
mechanisms as a function of resonator and substrate geometry, we identify
radiation loss through the supporting substrate as the dominant loss process.
In addition to pointing the way towards higher quality factors through
optimized substrate designs, our work realizes an enabling platform for the
observation and control of quantum behavior in a macroscopic mechanical system
coupled to a room temperature bath.


title:
Collapse of self-interacting fields in asymptotically flat spacetimes:
  do self-interactions render Minkowski spacetime unstable?

abstract:
  The nonlinear instability of anti-de Sitter spacetime has recently been
established with the striking result that generic initial data collapses to
form black holes. This outcome suggests that confined matter generically
collapses, and that collapse can only be halted -- at most -- by nonlinear
bound states. Here we provide evidence that such mechanism can operate even in
asymptotically flat spacetimes, by studying the evolution of the
Einstein-Klein-Gordon system for a self-interacting scalar field. We show that
(i) configurations which do not collapse promptly can do so after successive
reflections off the potential barrier, but (ii) that at intermediate amplitudes
and Compton wavelengths, collapse to black holes is replaced by the appearance
of oscillating soliton stars. Finally, (iii) for very small initial amplitudes,
the field disperses away in a manner consistent with power-law tails of massive
fields. Minkowski is stable against gravitational collapse. Our results provide
one further piece to the rich phenomenology of gravitational collapse and show
the important interplay between bound states, blueshift, dissipation and
confinement effects.


title: Kinematic consistency relations of large-scale structures

abstract:
  We describe how the kinematic consistency relations satisfied by density
correlations of the large-scale structures of the Universe can be derived
within the usual Newtonian framework. These relations express a kinematic
effect and show how the $(\ell+n)$-density correlation factors in terms of the
$n$-point correlation and $\ell$ linear power spectrum factors, in the limit
where the $\ell$ soft wave numbers become linear and much smaller than the $n$
other wave numbers. We describe how these relations extend to multifluid cases.
In the standard cosmology, these consistency relations derive from the
equivalence principle. A detection of their violation would indicate
non-Gaussian initial conditions, non-negligible decaying modes, or a
modification of gravity that does not converge to General Relativity on large
scales.


title:
A Quasianalytical Time Domain Mie Solution for Scattering from a
  Homogeneous Sphere

abstract:
  A transient Mie-like solution for acoustic scattering from a spherical object
is derived within a mesh-free and singularity-free Time Domain Integral
Equation (TDIE) framework for the sound-soft, sound-rigid and penetrable cases.
The method is based on an expansion of the time domain Green's function that
allows independent evaluation of spatial and temporal convolutions. Solution of
the TDIE system may be effected by descretizing the integral equations in space
and time, forming a matrix system via the Method of Moments, and solving the
system with the Marching on in Time algorithm. Spatial discretization using
tesseral harmonics leads to closed form expressions for spatial integrals, and
use of a strictly band limited temporal interpolant permits efficient, accurate
computation of temporal convolutions utilizing numerical quadrature. The
accuracy of these integrations ensures late time stability and accuracy of the
deconvolution data. Results presented demonstrate the accuracy and convergence
of the approach for broadband simulations against Fourier transformed
analytical data.


title: Homogeneous cosmologies as group field theory condensates

abstract:
  We give a general procedure, in the group field theory (GFT) formalism for
quantum gravity, for constructing states that describe macroscopic, spatially
homogeneous universes. These states are close to coherent (condensate) states
used in the description of Bose-Einstein condensates. The condition on such
states to be (approximate) solutions to the quantum equations of motion of GFT
is used to extract an effective dynamics for homogeneous cosmologies directly
from the underlying quantum theory. The resulting description in general gives
nonlinear and nonlocal equations for the 'condensate wavefunction' which are
analogous to the Gross-Pitaevskii equation in Bose-Einstein condensates. We
show the general form of the effective equations for current quantum gravity
models, as well as some concrete examples. We identify conditions under which
the dynamics becomes linear, admitting an interpretation as a
quantum-cosmological Wheeler-DeWitt equation, and give its semiclassical (WKB)
approximation in the case of a kinetic term that includes a Laplace-Beltrami
operator. For isotropic states, this approximation reproduces the classical
Friedmann equation in vacuum with positive spatial curvature. We show how the
formalism can be consistently extended from Riemannian signature to Lorentzian
signature models, and discuss the addition of matter fields, obtaining the
correct coupling of a massless scalar in the Friedmann equation from the most
natural extension of the GFT action. We also outline the procedure for
extending our condensate states to include cosmological perturbations. Our
results form the basis of a general programme for extracting effective
cosmological dynamics directly from a microscopic non-perturbative theory of
quantum gravity.


title:
Quantum criticality and Lifshitz transition in the Ising system
  CeRu2Si2: Comparison with YbRh2Si2

abstract:
  New thermoelectric power (TEP) measurements on prototype heavy-fermion
compounds close to magnetic quantum criticality are presented. The highly
sensitive technique of TEP is an unique tool to reveal Fermi surface
instabilities, referred here as Lifshitz transitions. The first focus is on the
Ising CeRu2Si2 series. Doping CeRu2Si2 with Rh produces a decoupling between
the first order metamagnetic transition and the pseudo-metamagnetism observed
in the pure compound. Comparison is made with the case of YbRh2Si2 which is
often considered as the archetype of local quantum criticality by contrast to
CeRu2Si2, taken as an example of spin-density wave criticality. Up to now for
ferromagnetic materials showing ferromagnetic wings, no simple case appears
where the Fermi surface is preserved between the ferromagnetic and paramagnetic
phases. An open issue is the consequence of Lifshitz transitions on
superconductivity in these multiband systems.


title:
Generalized Instantly Decodable Network Coding for Relay-Assisted
  Networks

abstract:
  In this paper, we investigate the problem of minimizing the frame completion
delay for Instantly Decodable Network Coding (IDNC) in relay-assisted wireless
multicast networks. We first propose a packet recovery algorithm in the single
relay topology which employs generalized IDNC instead of strict IDNC previously
proposed in the literature for the same relay-assisted topology. This use of
generalized IDNC is supported by showing that it is a super-set of the strict
IDNC scheme, and thus can generate coding combinations that are at least as
efficient as strict IDNC in reducing the average completion delay. We then
extend our study to the multiple relay topology and propose a joint generalized
IDNC and relay selection algorithm. This proposed algorithm benefits from the
reception diversity of the multiple relays to further reduce the average
completion delay in the network. Simulation results show that our proposed
solutions achieve much better performance compared to previous solutions in the
literature.


title:
Comparative Assembly Hubs: Web Accessible Browsers for Comparative
  Genomics

abstract:
  We introduce a pipeline to easily generate collections of web accessible UCSC
genome browsers interrelated by an alignment. Using the alignment, all
annotations and the alignment itself can be efficiently viewed with reference
to any genome in the collection, symmetrically. A new, intelligently scaled
alignment display makes it simple to view all changes between the genomes at
all levels of resolution, from substitutions to complex structural
rearrangements, including duplications.


title:
The signature of positive braids is linearly bounded by their first
  Betti number

abstract:
  We provide linear lower bounds for the signature of positive braids in terms
of the three genus of their braid closure. This yields linear bounds for the
topological slice genus of knots that arise as closures of positive braids.


title:
Magnetic structures and the Ce-Fe coupling induced Fe spin reorientation
  in CeFeAsO single crystal

abstract:
  Neutron and synchrotron resonant X-ray magnetic scattering (RXMS)
complemented by heat capacity and resistivity measurements reveal the evolution
of the magnetic structures of Fe and Ce sublattices in single crystal CeFeAsO.
The RXMS of magnetic reflections at the Ce $L_{\rm II}$-edge shows a magnetic
transition that is specific to the Ce antiferromagnetic long-range ordering at
$T_\texttt{Ce}\approx$ 4 K with short-range Ce ordering above $T_\texttt{Ce}$,
whereas neutron diffraction measurements of a few magnetic reflections indicate
a transition at $T^{*}\approx$ 12 K with unusual order parameter. Detailed
order parameter measurements on several magnetic reflections by neutrons show a
weak anomaly at 4 K which we associate with the Ce ordering. The successive
transitions at $T_\texttt{Ce}$ and $T^{*}$ can also be clearly identified by
two anomalies in heat capacity and resistivity measurements. The higher
transition temperature at $T^{*}\approx$ 12 K is mainly ascribed to Fe spin
reorientation transition, below which Fe spins rotate uniformly and gradually
in the \textit{ab} plane. The Fe spin reorientation transition and short-range
Ce ordering above $T_\texttt{Ce}$ reflect the strong Fe-Ce couplings prior to
long-range ordering of the Ce. The evolution of the intricate magnetic
structures in CeFeAsO going through $T^{*}$ and $T_\texttt{Ce}$ is proposed.


title: Hunting for topological dark matter with atomic clocks

abstract:
  The cosmological applications of atomic clocks so far have been limited to
searches of the uniform-in-time drift of fundamental constants. In this paper,
we point out that a transient in time change of fundamental constants can be
induced by dark matter objects that have large spatial extent, and are built
from light non-Standard Model fields. The stability of this type of dark matter
can be dictated by the topological reasons. We point out that correlated
networks of atomic clocks, some of them already in existence, can be used as a
powerful tool to search for the topological defect dark matter, thus providing
another important fundamental physics application to the ever-improving
accuracy of atomic clocks. During the encounter with a topological defect, as
it sweeps through the network, initially synchronized clocks will become
desynchronized. Time discrepancies between spatially-separated clocks are
expected to exhibit a distinct signature, encoding defect's space structure and
its interaction strength with the Standard Model fields.

categories: physics.atom-ph astro-ph.HE gr-qc hep-ph


title:
Nonlinear Plates Interacting with A Subsonic, Inviscid Flow via
  Kutta-Joukowski Interface Conditions

abstract:
  We analyze the well-posedness of a flow-plate interaction considered in [22,
24]. Specifically, we consider the Kutta-Joukowski boundary conditions for the
flow [20, 28, 26], which ultimately give rise to a hyperbolic equation in the
half-space (for the flow) with mixed boundary conditions. This boundary
condition has been considered previously in the lower-dimensional interactions
[1, 2], and dramatically changes the properties of the flow-plate interaction
and requisite analytical techniques.
  We present results on well-posedness of the fluid-structure interaction with
the Kutta-Joukowsky flow conditions in force. The semigroup approach to the
proof utilizes an abstract setup related to that in [16] but requires (1) the
use of a Neumann-flow map to address a Zaremba type elliptic problem and (2) a
trace regularity assumption on the acceleration potential of the flow. This
assumption is linked to invertibility of singular integral operators which are
analogous to the finite Hilbert transform in two dimensions. (We show the
validity of this assumption when the model is reduced to a two dimensional flow
interacting with a one dimensional structure; this requires microlocal
techniques.) Our results link the analysis in [16] to that in [1, 2].