title:
Allen-Cahn Approximation of Mean Curvature Flow in Riemannian manifolds
  I, uniform estimates

abstract:
  We are concerned with solutions to the parabolic Allen-Cahn equation in
Riemannian manifolds. For a general class of initial condition we show non
positivity of the limiting energy discrepancy. This in turn allows to prove
almost monotonicity formula (a weak counterpart of Huisken's monotonicity
formula) which gives a local uniform control of the energy densities at small
scales.
  Such results will be used in [40] to extend previous important results from
[31] in Euclidean space, showing convergence of solutions to the parabolic
Allen-Cahn equations to Brakke's motion by mean curvature in space forms.


title:
Allen-Cahn Approximation of Mean Curvature Flow in Riemannian manifolds
  II, Brakke's flows

abstract:
  We prove convergence of solutions to the parabolic Allen-Cahn equation to
Brakke's motion by mean curvature in space forms, generalizing previous results
from [15] in Euclidean space. We show that a sequence of measures, associated
to energy density of solutions of the parabolic Allen-Cahn equation, converges
in the limit to a family of rectifiable Radon measures, which evolves by mean
curvature flow in the sense of Brakke. A key role is played by a local almost
monotonicity formula (a weak counterpart of Huisken's monotonicity formula)
proved in [22], to get various density bounds for the limiting measures.


title:
Spectroscopy and Orbital Analysis of Bright Bolides Observed over the
  Iberian Peninsula from 2010 to 2012

abstract:
  We present the analysis of the atmospheric trajectory and orbital data of
four bright bolides observed over Spain, one of which is a potential meteorite
dropping event. Their absolute magnitude ranges from -10 to -11. Two of these
are of sporadic origin, although a Geminid and a kappa-Cygnid fireball are also
considered. These events were recorded in the framework of the continuous
fireball monitoring and spectroscopy campaigns developed by the SPanish Meteor
Network (SPMN) between 2010 and 2012. The tensile strength of the parent
meteoroids is estimated and the abundances of the main rock-forming elements in
these particles are calculated from the emission spectrum obtained for three of
these events. This analysis revealed a chondritic nature for these meteoroids.


title: Results and conjectures on simultaneous core partitions

abstract:
  An n-core partition is an integer partition whose Young diagram contains no
hook lengths equal to n. We consider partitions that are simultaneously a-core
and b-core for two relatively prime integers a and b. These are related to
abacus diagrams and the combinatorics of the affine symmetric group (type A).
We observe that self-conjugate simultaneous core partitions correspond to the
combinatorics of type C, and use abacus diagrams to unite the discussion of
these two sets of objects.
  In particular, we prove that (2n)- and (2mn+1)-core partitions correspond
naturally to dominant alcoves in the m-Shi arrangement of type C_n,
generalizing a result of Fishel--Vazirani for type A. We also introduce a major
statistic on simultaneous n- and (n+1)-core partitions and on self-conjugate
simultaneous (2n)- and (2n+1)-core partitions that yield q-analogues of the
Coxeter-Catalan numbers of type A and type C.
  We present related conjectures and open questions on the average size of a
simultaneous core partition, q-analogs of generalized Catalan numbers, and
generalizations to other Coxeter groups. We also discuss connections with the
cyclic sieving phenomenon and q,t-Catalan numbers.


title:
Dynamic polarizability of Rydberg atoms: Applicability of near-free
  electron approximation, gauge invariance and the Dirac sea

abstract:
  Ponderomotive energy shifts experienced by Rydberg atoms in optical fields
are known to be well approximated by the classical quiver energy of a free
electron. We examine such energy shifts quantum mechanically and elucidate how
they relate to the ponderomotive shift of a free electron in off-resonant
fields. We derive and evaluate corrections to the ponderomotive free electron
polarizability in the length and velocity (transverse or Coulomb) gauges, which
agree exactly as mandated by the gauge invariance. We also show how the free
electron value emerges from the Dirac equation through summation over the Dirac
sea states. We find that the free-electron AC Stark shift comes as an
expectation value of a term proportional to the square of the vector potential
in the velocity gauge. On the other hand, the same dominant contribution can be
obtained to first order via a series expansion of the exact energy shift from
the second order perturbation theory in the length gauge. Finally, we
numerically examine the validity of the free-electron approximation. The
correction to the free-electron value becomes smaller with increasing principal
quantum number, and it is well below a per cent for 60s states of Rb and Sr
away from the resonances.


title: Bounded rational points on curves

abstract:
  We establish the sharp estimate <<_d N^{2/d} for the number of rational
points of height at most N on an irreducible projective curve of degree d. We
deduce this from a result for general hypersurfaces that is sensitive to the
coefficients of the corresponding form.


title: The Higgs sector of the SUSY reduced 3-3-1 model

abstract:
  A supersymmetric version of the recently proposed reduced minimal 3-3-1 model
is considered and its Higgs sector is investigated. We focus on the mass
spectrum of the lightest scalars of the model. We show that Higgs mass of 125
GeV requires substantial radiative corrections. However, stops may develop
small mixing and must have mass around TeV. Moreover, some soft SUSY breaking
terms may lie at the electroweak scale, which alleviates some tension
concerning fine tuning of the related parameters. The lightest doubly charged
scalar may have mass around few hundreds of GeV, which can be probed at the
LHC, while the remaining scalars of the model have masses at TeV scale.


title: Reciprocal processes. A measure-theoretical point of view

abstract:
  This is a survey paper about reciprocal processes. The bridges of a Markov
process are also Markov. But an arbitrary mixture of these bridges fails to be
Markov in general. However, it still enjoys the interesting properties of a
reciprocal process. The structures of Markov and reciprocal processes are
recalled with emphasis on their time-symmetries. A review of the main
properties of the reciprocal processes is presented. Our measure-theoretical
approach allows for a unified treatment of the diffusion and jump processes.
Abstract results are illustrated by several examples and counter-examples.


title:
Towards realistic artificial benchmark for community detection
  algorithms evaluation

abstract:
  Assessing the partitioning performance of community detection algorithms is
one of the most important issues in complex network analysis. Artificially
generated networks are often used as benchmarks for this purpose. However,
previous studies showed their level of realism have a significant effect on the
algorithms performance. In this study, we adopt a thorough experimental
approach to tackle this problem and investigate this effect. To assess the
level of realism, we use consensual network topological properties. Based on
the LFR method, the most realistic generative method to date, we propose two
alternative random models to replace the Configuration Model originally used in
this algorithm, in order to increase its realism. Experimental results show
both modifications allow generating collections of community-structured
artificial networks whose topological properties are closer to those
encountered in real-world networks. Moreover, the results obtained with eleven
popular community identification algorithms on these benchmarks show their
performance decrease on more realistic networks.


title:
The first p-jet space of an elliptic curve: global functions and lifts
  of Frobenius

abstract:
  We prove that there are no non-constant global functions and no lifts of
Frobenius on the first $p$-jet space on an elliptic curve unless the elliptic
curve itself has a lift of Frobenius.


title: Invariant Theory of Finite Group Actions on Down-Up Algebras

abstract:
  We study Artin-Schelter Gorenstein fixed subrings of some Artin-Schelter
regular algebras of dimension 2 and 3 under finite group actions, and prove a
noncommutative version of the Kac-Watanabe and Gordeev theorem for these
algebras.


title:
New extremal binary self-dual codes of length 68 from quadratic residue
  codes over f_2+uf_2+u^2f_2

abstract:
  In this work, quadratic reside codes over the ring F2 +uF2 +u^2F2 with u^3 =
u are considered. A duality and distance preserving Gray map from F2 + uF2 +
u^2F2 to (F_2)^3 is defined. By using quadratic double circulant, quadratic
bordered double circulant constructions and their extensions self- dual codes
of different lengths are obtained. As Gray images of these codes and their
extensions, a substantial number of new extremal self-dual binary codes are
found. More precisely, thirty two new extremal binary self-dual codes of length
68, 363 Type I codes of parameters [72; 36; 12], a Type II [72; 36; 12] code
and a Type II [96; 48; 16] code with new weight enumerators are obtained
through these constructions. The results are tabulated.


title:
Effective Dark Energy Models and Dark Energy Models with Bounce in
  frames of $F(T)$ Gravity

abstract:
  Various cosmological models in frames of $F(T)$ gravity are considered. The
general scheme of constructing effective dark energy models with various
evolution is presented. It is showed that these models in principle are
compatible with $\Lambda$CDM model. The dynamics of universe governed by $F(T)$
gravity can mimics $\Lambda$CDM evolution in past but declines from it in a
future. We also construct some dark energy models with the "real"
(non-effective) equation-of-state parameter $w$ such that $w\leq-1$. It is
showed that in $F(T)$ gravity the Universe filled phantom field not necessarily
ends its existence in singularity. There are two possible mechanisms permitting
the final singularity. Firstly due to the nonlinear dependence between energy
density and $H^{2}$ ($H$ is the Hubble parameter) the universe can expands not
so fast as in the general relativity and in fact Little Rip regime take place
instead Big Rip. We also considered the models with possible bounce in future.
In these models the universe expansion can mimics the dynamics with future
singularity but due to bounce in future universe begin contracts.


title: Multiplicities of Classical Varieties

abstract:
  The $j$-multiplicity plays an important role in the intersection theory of
St\"uckrad-Vogel cycles, while recent developments confirm the connections
between the $\epsilon$-multiplicity and equisingularity theory. In this paper
we establish, under some constraints, a relationship between the
$j$-multiplicity of an ideal and the degree of its fiber cone. As a
consequence, we are able to compute the $j$-multiplicity of all the ideals
defining rational normal scrolls. By using the standard monomial theory, we can
also compute the $j$- and $\epsilon$-multiplicity of ideals defining
determinantal varieties: The found quantities are integrals which, quite
surprisingly, are central in random matrix theory.


title: Verification of Sequential Circuits by Tests-As-Proofs Paradigm

abstract:
  We introduce an algorithm for detection of bugs in sequential circuits. This
algorithm is incomplete i.e. its failure to find a bug breaking a property P
does not imply that P holds. The appeal of incomplete algorithms is that they
scale better than their complete counterparts. However, to make an incomplete
algorithm effective one needs to guarantee that the probability of finding a
bug is reasonably high. We try to achieve such effectiveness by employing the
Test-As-Proofs (TAP) paradigm. In our TAP based approach, a counterexample is
built as a sequence of states extracted from proofs that some local variations
of property P hold. This increases the probability that a) a representative set
of states is examined and that b) the considered states are relevant to
property P.
  We describe an algorithm of test generation based on the TAP paradigm and
give preliminary experimental results.


title: Flavored Dark Matter: A Review

abstract:
  The current status of flavored dark matter is reviewed. We discuss the main
experimental constraints on models of flavored dark matter and survey some
possible considerations which are relevant for the constructions of models. We
then review the application of existing flavor principles to dark matter, with
an emphasis on minimal flavor violation, and discuss implications of flavored
dark matter on collider phenomenology.


title:
Data Center Cost Optimization Via Workload Modulation Under Real-World
  Electricity Pricing

abstract:
  We formulate optimization problems to study how data centers might modulate
their power demands for cost-effective operation taking into account three key
complex features exhibited by real-world electricity pricing schemes: (i)
time-varying prices (e.g., time-of-day pricing, spot pricing, or higher energy
prices during coincident peaks) and (ii) separate charge for peak power
consumption. Our focus is on demand modulation at the granularity of an entire
data center or a large part of it. For computational tractability reasons, we
work with a fluid model for power demands which we imagine can be modulated
using two abstract knobs of demand dropping and demand delaying (each with its
associated penalties or costs). Given many data center workloads and electric
prices can be effectively predicted using statistical modeling techniques, we
devise a stochastic dynamic program (SDP) that can leverage such predictive
models. Since the SDP can be computationally infeasible in many real platforms,
we devise approximations for it. We also devise fully online algorithms that
might be useful for scenarios with poor power demand or utility price
predictability. For one of our online algorithms, we prove a competitive ratio
of 2-1/n. Finally, using empirical evaluation with both real-world and
synthetic power demands and real-world prices, we demonstrate the efficacy of
our techniques. As two salient empirically-gained insights: (i) demand delaying
is more effective than demand dropping regarding to peak shaving (e.g., 10.74%
cost saving with only delaying vs. 1.45% with only dropping for Google
workload) and (ii) workloads tend to have different cost saving potential under
various electricity tariffs (e.g., 16.97% cost saving under peak-based tariff
vs. 1.55% under time-varying pricing tariff for Facebook workload).


title: A note on norm-based Lyapunov functions via contraction analysis

abstract:
  It is well know that for globally contractive autonomous systems, there
exists a unique equilibrium and the distance to the equilibrium evaluated along
any trajectory decreases exponentially with time. We show that, additionally,
the magnitude of the velocity evaluated along any trajectory decreases
exponentially, thus giving an alternative choice of Lyapunov function.


title:
Double parton scattering in four-jet events in pp collisions at 7 TeV
  with the ATLAS experiment at the LHC

abstract:
  The dijet double-differential cross section is measured as a function of the
dijet invariant mass, using data taken during 2010 and during 2011 with the
ATLAS experiment at the LHC, with a center-of-mass energy of 7 TeV. The
measurements are sensitive to invariant masses between 70 GeV and 4.27 TeV with
center-of-mass jet rapidities up to 3.5. A novel technique to correct jets for
pile-up (additional proton-proton collisions) in the 2011 data is developed and
subsequently used in the measurement. The data are found to be consistent with
fixed-order NLO pQCD predictions provided by NLOJET++. The results constitute a
stringent test of pQCD, in an energy regime previously unexplored. The dijet
analysis is a confidence building step for the extraction of the signal of hard
double parton scattering (DPS) in four-jet events, and subsequent extraction of
the effective overlap area between the interacting protons, expressed in terms
of the variable, \sigma(eff). The measurement of DPS is performed using the
2010 ATLAS data. The rate of DPS events is estimated using a neural network. A
clear signal is observed, under the assumption that the DPS signal can be
represented by a random combination of exclusive dijet production. The fraction
of DPS candidate events is determined to be f(DPS) = 0.081 +- 0.004 (stat.)
+0.025-0.014 (syst.) in the analyzed phase-space of four-jet topologies.
Combined with the measurement of the dijet and four-jet cross sections in the
appropriate phase-space regions, the effective cross section is found to be
\sigma(eff) = 16.0 +0.5-0.8 (stat.) +1.9-3.5 (syst.) mb. This result is
consistent within the quoted uncertainties with previous measurements of
\sigma(eff) at center-of-mass energies between 63 GeV and 7 TeV, using several
final states.


title:
Fast coherent manipulation of three-electron states in a double quantum
  dot

abstract:
  A fundamental goal in the manipulation of quantum systems is the achievement
of many coherent oscillations within the characteristic dephasing time T2*[1].
Most manipulations of electron spins in quantum dots have focused on the
construction and control of two-state quantum systems, or qubits, in which each
quantum dot is occupied by a single electron[2-7]. Here we perform quantum
manipulations on a system with more electrons per quantum dot, in a double dot
with three electrons. We demonstrate that tailored pulse sequences can be used
to induce coherent rotations between 3-electron quantum states. Certain pulse
sequences yield coherent oscillations with a very high figure of merit (the
ratio of coherence time to rotation time) of >100. The presence of the third
electron enables very fast rotations to all possible states, in contrast to the
case when only two electrons are used, in which some rotations are slow. The
minimum oscillation frequency we observe is >5 GHz.


title: Asymptotic Symmetries of Yang-Mills Theory

abstract:
  Asymptotic symmetries at future null infinity (I+) of Minkowski space for
electrodynamics with massless charged fields, as well as non-Abelian gauge
theories with gauge group G, are considered at the semiclassical level. The
possibility of charge/color flux through I+ suggests the symmetry group is
infinite-dimensional. It is conjectured that the symmetries include a G
Kac-Moody symmetry whose generators are "large" gauge transformations which
approach locally holomorphic functions on the conformal two-sphere at I+ and
are invariant under null translations. The Kac-Moody currents are constructed
from the gauge field at the future boundary of I+. The current Ward identities
include Weinberg's soft photon theorem and its colored extension.


title: Semiclassical approach to 2d impurity bound states in Dirac systems

abstract:
  The goal of this paper is to provide an intuitive and useful tool for
analyzing the impurity bound state problem. We develop a semiclassical approach
and apply it to an impurity in two dimensional systems with parabolic or Dirac
like bands. Our method consists of reducing a higher dimensional problem into a
sum of one dimensional ones using the two dimensional Green functions as a
guide. We then analyze the one dimensional effective systems in the spirit of
the wave function matching method as in the standard 1d quantum model. We
demonstrate our method on two dimensional models with parabolic and Dirac-like
dispersion, with the later specifically relevant to topological insulators.


title:
Advantages of Multiple Detectors for the Neutrino Mass Hierarchy
  Determination at Reactor Experiments

abstract:
  We study the advantages of a second identical detector at a medium baseline
reactor neutrino experiment. A major obstruction to the determination of the
neutrino mass hierarchy is the detector's unknown nonlinear energy response,
which even under optimistic assumptions reduces the confidence in a hierarchy
determination by about 1 sigma at a single detector experiment. Various energy
response models are considered at one and two detector experiments with the
same total target mass. A second detector at a sufficiently different baseline
eliminates this 1 sigma reduction. Considering the unknown energy response, we
find the confidence in a hierarchy determination at various candidate detector
locations for JUNO and RENO 50. The best site for JUNO's near detector is under
ZiLuoShan, 17 km and 66 km from the Yangjiang and Taishan reactor complexes
respectively. We briefly describe other advantages, including a more precise
determination of theta12 and the possibility of a DAEdALUS-inspired program to
measure the CP-violating phase delta using a single pion source about 10 km
from one detector and 20 km from the other. Two identical detectors provide a
better energy resolution than a single (larger) detector, further increasing
the confidence in a hierarchy determination.


title:
Dark matter with $t$-channel mediator: a simple step beyond contact
  interaction

abstract:
  Effective contact operators provide the simplest parameterization of dark
matter searches at colliders. However, light mediator can significantly change
the sensitivity and search strategies. Considering simple models of mediators
is an important next-step for collider searches. In this paper, we consider the
case of a $t$-channel mediator. Its presence opens up new contributions to the
monojet$+\displaystyle{\not{E}}_T$ searches and can change the reach
significantly. We also study the complementarity between searches for processes
of monojet$+\displaystyle{\not{E}}_T$ and direct pair production of the
mediators. Mediator pair production also gives important contribution to a
CMS-like monojet$+\displaystyle{\not{E}}_T$ search where a second hard jet is
allowed.There is a large region of parameter space in which the
monojet$+\displaystyle{\not{E}}_T$ search provides the stronger limit. Assuming
the relic abundance of the dark matter is thermally produced within the
framework of this model, we find that in the Dirac fermion dark matter case,
there is no region in the parameter space that satisfies the combined
constraint of monojet$+\displaystyle{\not{E}}_T$ search and direct detection;
whereas in the Majorana fermion dark matter case, the mass of dark matter must
be larger than about 100 GeV. If the relic abundance requirement is not
assumed, the discovery of the $t$-channel mediator predicts additional new
physics.


title:
Mapping the Three-Dimensional Density of the Galactic Bulge with VVV Red
  Clump Stars

abstract:
  The inner Milky Way is dominated by a boxy, triaxial bulge which is believed
to have formed through disk instability processes. Despite its proximity, its
large-scale properties are still not very well known, due to our position in
the obscuring Galactic disk. Here we make a measurement of the
three-dimensional density distribution of the Galactic bulge using red clump
giants identified in DR1 of the VVV survey. Our density map covers the inner
(2.2x1.4x1.1)kpc of the bulge/bar. Line-of-sight density distributions are
estimated by deconvolving extinction and completeness corrected K-band
magnitude distributions. In constructing our measurement, we assume that the
three-dimensional bulge is 8-fold mirror triaxially symmetric. In doing so we
measure the angle of the bar-bulge to the line-of-sight to be (27+- 2)deg,
where the dominant error is systematic arising from the details of the
deconvolution process. The resulting density distribution shows a highly
elongated bar with projected axis ratios ~(1:2.1) for isophotes reaching ~2kpc
along the major axis. Along the bar axes the density falls off roughly
exponentially, with axis ratios (10:6.3:2.6) and exponential scale-lengths
(0.70:0.44:0.18)kpc. From about 400pc above the Galactic plane, the bulge
density distribution displays a prominent X-structure. Overall, the density
distribution of the Galactic bulge is characteristic for a strongly boxy/peanut
shaped bulge within a barred galaxy.


title: Blazars spectral properties at 74 MHz

abstract:
  Blazars are the most extreme class of active galactic nuclei (AGNs). Despite
a previous investigation at 102 MHz for a small sample of BL Lacs and our
recent analysis of blazars detected in the Westerbork Northern Sky Survey
(WENSS), a systematic study of the blazar spectral properties at frequencies
below 100 MHz has been never carried out. In this paper, we present the first
analysis of the radio spectral behavior of blazars based on the recent Very
Large Array Low-Frequency Sky Survey (VLSS) at 74 MHz. We search for blazar
counterparts in the VLSS catalog confirming that they are detected at 74 MHz.
We then show that blazars present radio flat spectra {(i.e., radio spectral
indices ~0.5)} when evaluated also about an order of magnitude in frequency
lower than previous analyses. Finally, we discuss the implications of our
findings in the context of the blazars - radio galaxies connection since the
low frequency radio data provide a new diagnostic tool to verify the
expectations of the unification scenario for radio-loud active galaxies.


title:
Fermi Large Area Telescope Detection of Two Very-High-Energy (E>100 GeV)
  Gamma-ray Photons from the z = 1.1 Blazar PKS 0426-380

abstract:
  We report the Fermi Large Area Telescope (LAT) detection of two
very-high-energy (VHE, E>100 GeV) gamma-ray photons from the directional
vicinity of the distant (redshift, z = 1.1) blazar PKS 0426-380. The null
hypothesis that both the 134 and 122 GeV photons originate from unrelated
sources can be rejected at the 5.5 sigma confidence level. We therefore claim
that at least one of the two VHE photons is securely associated with the
blazar, making PKS 0426-380 the most distant VHE emitter known to date. The
results are in agreement with the most recent Fermi-LAT constraints on the
Extragalactic Background Light (EBL) intensity, which imply a $z \simeq 1$
horizon for $\simeq$ 100 GeV photons. The LAT detection of the two VHE
gamma-rays coincided roughly with flaring states of the source, although we did
not find an exact correspondence between the VHE photon arrival times and the
flux maxima at lower gamma-ray energies. Modeling the gamma-ray continuum of
PKS 0426-380 with daily bins revealed a significant spectral hardening around
the time of detection of the first VHE event (LAT photon index \Gamma\ $\simeq$
1.4) but on the other hand no pronounced spectral changes near the detection
time of the second one. This combination implies a rather complex variability
pattern of the source in gamma rays during the flaring epochs. An additional
flat component is possibly present above several tens of GeV in the
EBL-corrected Fermi-LAT spectrum accumulated over the ~8-month high state.


title: The curiously circular orbit of Kepler-16b

abstract:
  The recent discovery of a number of circumbinary planets lends a new tool to
astrophysicists seeking to understand how and where planet formation takes
place. Of the increasingly numerous circumbinary systems, Kepler-16 is arguably
the most dynamically interesting: it consists of a planet on an almost
perfectly circular orbit (e = 0.0069) around a moderately eccentric binary (e =
0.16). We present high-resolution 3D smoothed-particle hydrodynamics
simulations of a Kepler-16 analogue embedded in a circumbinary disc, and show
that the planet's eccentricity is damped by its interaction with the
protoplanetary disc. We use this to place a lower limit on the gas surface
density in the real disc through which Kepler-16b migrated of \Sigma_min ~ 10 g
cm^-2. This suggests that Kepler-16b, and other circumbinary planets, formed
and migrated in relatively massive discs. We argue that secular evolution of
circumbinary discs requires that these planets likely formed early on in the
lifetime of the disc and migrated inwards before the disc lost a significant
amount of its original mass.


title: The Epoch of Assembly of Two Galaxy Groups: A comparative study

abstract:
  Nearby galaxy groups of comparable mass to the Local Group show global
variations that reflect differences in their evolutionary history. Satellite
galaxies in groups have higher levels of gas deficiency as the distance to
their host decreases. The well established gas deficiency profile of the Local
Group reflects an epoch of assembly starting at z<10. We investigate whether
this gas deficiency profile can be used to determine the epoch of assembly for
other nearby groups. We choose the M81 group as this has the most complete
inventory, both in terms of membership and multi-wavelength observations. We
expand our earlier evolutionary model of satellite dwarf galaxies to not only
confirm this result for the Local Group but show that the more gas-rich M81
group is likely to have assembled at a later time (z<1-3).


title: Parton distributions with QED corrections

abstract:
  We present a set of parton distribution functions (PDFs), based on the
NNPDF2.3 set, which includes a photon PDF, and QED contributions to parton
evolution. We describe the implementation of the combined QCD+QED evolution in
the NNPDF framework. We then provide a first determination of the full set of
PDFs based on deep-inelastic scattering data and LHC data for W and Z/gamma*
Drell-Yan production, using leading-order QED and NLO or NNLO QCD. We compare
the ensuing NNPDF2.3QED PDF set to the older MRST2004QED set. We perform a
preliminary investigation of the phenomenological implications of NNPDF2.3QED:
specifically, photon-induced corrections to direct photon production at HERA,
and high-mass dilepton and W pair production at the LHC.


title:
An Exoplanet's Response to Anisotropic Stellar Mass-Loss During Birth
  and Death

abstract:
  The birth and death of planets may be affected by mass outflows from their
parent stars during the T-Tauri or post-main-sequence phases of stellar
evolution. These outflows are often modelled to be isotropic, but this
assumption is not realistic for fast rotators, bipolar jets and supernovae.
Here we derive the general equations of motion for the time evolution of a
single planet, brown dwarf, comet or asteroid perturbed by anisotropic mass
loss in terms of a complete set of planetary orbital elements, the ejecta
velocity, and the parent star's co-latitude and longitude. We restrict our
application of these equations to 1) rapidly rotating giant stars, and 2)
arbitrarily-directed jet outflows. We conclude that the isotropic mass-loss
assumption can safely be used to model planetary motion during giant branch
phases of stellar evolution within distances of hundreds of au. In fact,
latitudinal mass loss variations anisotropically affect planetary motion only
if the mass loss is asymmetric about the stellar equator. Also, we demonstrate
how constant-velocity, asymmetric bipolar outflows in young systems incite
orbital inclination changes. Consequently, this phenomenon readily tilts
exoplanetary orbits external to a nascent disc on the order of degrees.


title: An investigation of the line of sight towards QSO PKS 0237-233

abstract:
  We present a detailed analysis of absorption systems along the line of sight
towards QSO PKS 0237-233 using a high resolution spectrum of signal-to-noise
ratio (SNR) ~ 60-80 obtained with the Ultraviolet and Visual Echelle
Spectrograph mounted on the Very Large Telescope. This line of sight is known
to show a remarkable overdensity of CIV systems that has been interpreted as
revealing the presence of a supercluster of galaxies. A detailed analysis of
each of these absorption systems is presented. In particular, for the z_abs =
1.6359 (with two components of logN(HI) = 18.45, 19.05) and z_abs = 1.6720
(logN(H I) = 19.78) sub-Damped Ly-alpha systems (sub-DLAs), we measure accurate
abundances (resp. [O/H] = -1.63(0.07) and [Zn/H] = - 0.57(0.05) relative to
solar). While the depletion of refractory elements onto dust grains in both
sub-DLAs is not noteworthy, photoionization models show that ionization effects
are important in a part of the absorbing gas of the sub-DLA at z_abs = 1.6359
(HI is 95 percent ionized) and in part of the gas of the sub-DLA at z_abs =
1.6359. The CIV clustering properties along the line of sight is studied in
order to investigate the nature of the observed overdensity. We conclude that
despite the unusually high number of CIV systems detected along the line of
sight, there is no compelling evidence for the presence of a single unusual
overdensity and that the situation is consistent with chance coincidence.


title: Strong- versus Weak-Coupling Paradigms for Cuprate Superconductivity

abstract:
  Absolute resistivity measurements as a function of temperature from optimally
doped YBa_2Cu_3O_(7), La_(2-x)Sr_xCuO_4, Bi_2Sr_2CaCu_2O_(8-x), and
(Ca_0.1La_0.9)(Ba_1.65La_0.35)Cu_3O_y thin films are reported. Special
attention is given to the measurement geometrical factors and the resistivity
slope between Tc and T^{*}. The results are compared with a strong coupling
theory for the resistivity derivative near T_c, which is based on hard core
bosons (HCB), and with several weak coupling theories, which are BCS based.
Surprisingly, our results agree with both paradigms. The implications of these
findings and the missing calculations needed to distinguish between the two
paradigms are discussed.


title: Sparse Inpainting and Isotropy

abstract:
  Sparse inpainting techniques are gaining in popularity as a tool for
cosmological data analysis, in particular for handling data which present
masked regions and missing observations. We investigate here the relationship
between sparse inpainting techniques using the spherical harmonic basis as a
dictionary and the isotropy properties of cosmological maps, as for instance
those arising from cosmic microwave background (CMB) experiments. In
particular, we investigate the possibility that inpainted maps may exhibit
anisotropies in the behaviour of higher-order angular polyspectra. We provide
analytic computations and simulations of inpainted maps for a Gaussian
isotropic model of CMB data, suggesting that the resulting angular trispectrum
may exhibit small but non-negligible deviations from isotropy.


title: Realizing a Kondo-correlated state with ultracold atoms

abstract:
  We propose a novel realization of Kondo physics with ultracold atomic gases.
It is based on a Fermi sea of two different hyperfine states of one atom
species forming bound states with a different species, which is spatially
confined in a trapping potential. We show that different situations displaying
Kondo physics can be realized when Feshbach resonances between the species are
tuned by a magnetic field and the trapping frequency is varied. We illustrate
that a mixture of ${}^{40}$K and ${}^{23}$Na atoms can be used to generate a
Kondo correlated state and that momentum resolved radio frequency spectroscopy
can provide unambiguous signatures of the formation of Kondo resonances at the
Fermi energy. We discuss how tools of atomic physics can be used to investigate
open questions for Kondo physics, such as the extension of the Kondo screening
cloud.


title:
Recovering galaxy stellar population properties from broad-band spectral
  energy distribution fitting II. The case with unknown redshift

abstract:
  (Abridged) In a recent work we explored the dependence of galaxy stellar
population properties derived from broad-band spectral energy distribution
fitting on the fitting parameters, e.g. SFHs, age grid, metallicity, IMF, dust
reddening, reddening law, filter setup and wavelength coverage. In this paper
we consider also redshift as a free parameter in the fit and study whether one
can obtain reasonable estimates of photometric redshifts and stellar population
properties at once. We use mock star-forming as well as passive galaxies placed
at various redshifts (0.5 to 3) as test particles. Mock star-forming galaxies
are extracted from a semi-analytical galaxy formation model. We show that for
high-z star-forming galaxies photometric redshifts, stellar masses and
reddening can be determined simultaneously when using a broad wavelength
coverage and a wide template setup in the fit. Masses are similarly well
recovered (median ~ 0.2 dex) as at fixed redshift. For old galaxies with little
recent star formation masses are better recovered than in the fixed redshift
case, such that the median recovered stellar mass improves by up to 0.3 dex
whereas the uncertainty in the redshift accuracy increases by only ~ 0.05.
However, a failure in redshift recovery also means a failure in mass recovery.
As at fixed redshift mismatches in SFH and degeneracies between age, dust and
now also redshift cause underestimated ages, overestimated reddening and
underestimated masses. Stellar masses are best determined at low redshift
without reddening in the fit (median underestimation ~ 0.1 dex for similarly
well recovered redshifts). Not surprisingly, the recovery of properties is
substantially better for passive galaxies. In all cases, the recovery of
physical parameters is crucially dependent on the wavelength coverage adopted
in the fitting. Scaling relations for the transformation of stellar masses are
provided.


title: A Clash of Kinks: Phase shifts in colliding non-integrable solitons

abstract:
  We derive a closed-form expression for the phase shift experienced by 1+1
dimensional kinks colliding at ultra-relativistic velocities (gamma v >> 1),
valid for arbitrary periodic potentials. Our closed-form expression is the
leading order result of a more general scattering theory of solitary waves
described in a companion paper [Amin, Lim and Yang, arXiv:1308.0606]. This
theory relies on a small kinematic parameter 1/(gamma v) << 1 rather than a
small parameter in the Lagrangian. Our analytic results can be directly
extracted from the Lagrangian without solving the equation of motion. Based on
our closed-form expression, we prove that kink-kink and kink-antikink
collisions have identical phase shifts at leading order.

categories: hep-th astro-ph.CO hep-ph nlin.PS nlin.SI


title: A scattering theory of ultrarelativistic solitons

abstract:
  We construct a perturbative framework for understanding the collision of
solitons (more precisely, solitary waves) in relativistic scalar field
theories. Our perturbative framework is based on the suppression of the
space-time interaction area proportional to $1/(\gamma v)$, where $v$ is the
relative velocity of an incoming solitary wave and $\gamma = 1/\sqrt{1-v^2} \gg
1$. We calculate the leading order results for collisions of (1+1) dimensional
kinks in periodic potentials, and provide explicit, closed form expressions for
the phase shift and the velocity change after the collisions. We find excellent
agreement between our results and detailed numerical simulations. Crucially,
our perturbation series is controlled by a kinematic parameter, and hence not
restricted to small deviations around integrable cases such as the Sine-Gordon
model.


title:
New developments for modern celestial mechanics. I. General coplanar
  three-body systems. Application to exoplanets

abstract:
  Modern applications of celestial mechanics include the study of closely
packed systems of exoplanets, circumbinary planetary systems, binary-binary
interactions in star clusters, and the dynamics of stars near the galactic
centre. While developments have historically been guided by the architecture of
the Solar System, the need for more general formulations with as few
restrictions on the parameters as possible is obvious. Here we present clear
and concise generalisations of two classic expansions of the three-body
disturbing function, simplifying considerably their original form and making
them accessible to the non-specialist. Governing the interaction between the
inner and outer orbits of a hierarchical triple, the disturbing function in its
general form is the conduit for energy and angular momentum exchange and as
such, governs the secular and resonant evolution of the system and its
stability characteristics. Focusing here on coplanar systems, the first
expansion is one in the ratio of inner to outer semimajor axes and is valid for
all eccentricities, while the second is an expansion in eccentricity and is
valid for all semimajor axis ratios [...]. Our generalizations make both
formulations valid for arbitrary mass ratios. [...]. We demonstrate the
equivalence of the new expansions, identifying the role of the spherical
harmonic order m in both and its physical significance in the three-body
problem, and introducing the concept of principal resonances. Several examples
of the accessibility of both expansions are given including resonance widths
and the secular rates of change of the elements. Results in their final form
are gathered together at the end of the paper for the reader mainly interested
in their application, including a guide for the choice of expansion.


title:
Compression d'images par SVD et sur-approximation des composantes de
  chrominance

abstract:
  This paper gives a new scheme of colour image compression related to singular
values matrix approximation. The image has to be converted in luminance /
chrominance space before being processed like JPEG standard 4 : 2 : 0. Our
approach is first based on a chrominance sub-sampling, then an over estimation
of its singular values. Instead of keeping only the k first singular values for
the 3 components R, G and B, we hold k first coefficients for the Y component
and only k' (k' <= k) coefficients for 2 components Cb and Cr. Results show
that for 512 x 512 pixels that, from k = 40 corresponding in an average
distortion of 30 dB and a ratio of 15 : 1, the restored image has good quality.
The algorithm allows a significant speed gain by sub-sampling too.


title:
Long and short term variability of seven blazars in six
  near-infrared/optical bands

abstract:
  Context. We present the light curves of six BL Lac objects, PKS 0537-441, PKS
0735+17, OJ 287, PKS 2005-489, PKS 2155-304, W Comae, and of the flat spectrum
radio quasar PKS 1510-089, as a part of a photometric monitoring program in the
near-infrared/optical bands started in 2004. All sources are Fermi blazars.
Aims. Our purpose is to investigate flux and spectral variability on short and
long time scales. Systematic monitoring, independent of the activity of the
source, guarantees large sample size statistics, and allows an unbiased view of
different activity states on weekly or daily time scales for the whole
timeframe and on nightly timescales for some epochs. Methods. Data were
obtained with the REM telescope located at the ESO premises of La Silla
(Chile). Light curves were gathered in the optical/near-infrared VRIJHK bands
from April 2005 to June 2012. Results. Variability >= 3 mag is observed in PKS
0537-441, PKS 1510-089 and PKS 2155-304, the largest ranges spanned in the
near-infrared. The color intensity plots show rather different morphologies.
The spectral energy distributions in general are well fitted by a power law,
with some deviations that are more apparent in low states. Some variability
episodes during a night interval are well documented for PKS 0537-441 and PKS
2155-304. For the latter source the variability time scale implies a large
relativistic beaming factor.


title: Study of high energy cosmic ray acceleration in Tycho SNR with VERITAS

abstract:
  Supernova Remnants (SNRs) are broadly accepted as the main accelerators of
Galactic cosmic rays (GCRs) with energies up to the knee region. Recent
measurements of pion bumps in IC 443 and W 44 by Fermi-LAT show indirect
evidence of the acceleration of hadronic particles in SNRs. But, whether SNRs
are the powerhouses for GCR acceleration all the way up to the knee region
still remains an unsolved question. Tycho is a promising target for this study
because it has been widely studied in multi-wavelength observations from IR to
TeV and it is a young type Ia SNR located in a relatively clean environment.
Though recently developed models generally agree on the likely hadronic origin
of the gamma-ray emission from Tycho, the details of the models vary
considerably because the current data in the GeV-TeV range are weakly
constraining. Since the initial detection, VERITAS has increased its data size
by more than 40%. We also recently upgraded the telescope cameras and the
analysis packages, which will allow us to extend the measurements toward both
lower and higher energies. In this talk, I present updates on the VHE gamma-ray
measurements of Tycho with VERITAS, focusing on the interpretation of the
additional data in the context of hadronic GCR acceleration models.


title: The 1-2-3 Conjecture for Hypergraphs

abstract:
  A weighting of the edges of a hypergraph is called vertex-coloring if the
weighted degrees of the vertices yield a proper coloring of the graph, i.e.,
every edge contains at least two vertices with different weighted degrees. In
this paper we show that such a weighting is possible from the weight set
{1,2,...,r+1} for all hypergraphs with maximum edge size r>3 and not containing
edges solely consisting of identical vertices. The number r+1 is best possible
for this statement.
  Further, the weight set {1,2,3,4,5} is sufficient for all hypergraphs with
maximum edge size 3, up to some trivial exceptions.


title: Fermion Portal Dark Matter

abstract:
  We study a class of simplified dark matter models in which one dark matter
particle couples with a mediator and a Standard Model fermion. In such models,
collider and direct detection searches probe complimentary regions of parameter
space. For Majorana dark matter, direct detection covers the region near
mediator-dark matter degeneracy, while colliders probe regions with a large
dark matter and mediator mass splitting. For Dirac and complex dark matter,
direct detection is effective for the entire region above the mass threshold,
but colliders provide a strong bound for dark matter lighter than a few GeV. We
also point out that dedicated searches for signatures with two jets or a
mono-jet not coming from initial state radiation, along missing transverse
energy can cover the remaining parameter space for thermal relic dark matter.


title: Database optimization for empirical interatomic potential models

abstract:
  Weighted least squares fitting to a database of quantum mechanical
calculations can determine the optimal parameters of empirical potential
models. While algorithms exist to provide optimal potential parameters for a
given fitting database of structures and their structure property functions,
and to estimate prediction errors using Bayesian sampling, defining an optimal
fitting database based on potential predictions remains elusive. A testing set
of structures and their structure property functions provides an empirical
measure of potential transferability. Here, we propose an objective function
for fitting databases based on testing set errors. The objective function
allows the optimization of the weights in a fitting database, the assessment of
the inclusion or removal of structures in the fitting database, or the
comparison of two different fitting databases. To showcase this technique, we
consider an example Lennard-Jones potential for Ti, where modeling multiple
complicated crystal structures is difficult for a radial pair potential. The
algorithm finds different optimal fitting databases, depending on the objective
function of potential prediction error for a testing set.


title: Stretched exponential spin relaxation in organic superconductors

abstract:
  Proton NMR measurements on the organic superconductor
$\kappa-(ET)_2Cu[N(CN)_2]Br$ ($T_C = 11.6$ K) exhibit stretched exponential
spin-lattice relaxation below $T\approx 25$ K, suggestive of an inhomogeneous
magnetic phase that develops in the normal state and coexists with
superconductivity. The onset of this phase coincides approximately with a large
normal state Nernst signal reported previously. By contrast, the closely
related superconductor $\kappa-(ET)_2Cu[(NCS)_2]Br$ ($T_C = 10.5$ K) shows
single exponential spin-lattice relaxation and a conventional Nernst effect.
The temperature range $T_C < T < 30$ K encompasses several phenomena in the
$\kappa-(ET)_2X$ conductors, including changes in conduction electron spin
resonance, electronic phase separation and the onset of antiferromagnetic
order. Analogous behavior in $La_{2-x}Sr_xCuO_4$ suggests that a density wave
may develop in $\kappa-(ET)_2Cu[N(CN)_2]Br$.


title: The Segal-Bargmann transform for unitary groups in the large-N limit

abstract:
  This paper describes results of the author with B. K. Driver and T. Kemp
concerning the large-N limit of the Segal--Bargmann transform for the unitary
group U(N). We consider the transform on matrix-valued functions that are
polynomials in a single variable in U(N). We show that in the large-N limit,
the transform maps functions of this type to single-variable polynomial
functions on the complex group GL(N;C). This result was conjectured by Ph.
Biane and was also proved independently by G. C\'ebron. The first main
ingredient in our proof of this result is an "asymptotic product rule" for the
Laplacian on U(N), which allows us to compute explicitly the leading-order
large-N behavior of the heat operator on U(N). The second main ingredient in
the proof is the phenomenon of "concentration of traces," in which the relevant
heat kernel measures are concentrating onto sets where the trace of any power
of the variable is constant.


title: Geophysical Classification of Planets, Dwarf Planets, and Moons

abstract:
  A planetary mass scale and a system of composition codes are presented for
describing the geophysical characteristics of exoplanets and Solar System
planets, dwarf planets, and spherical moons. The composition classes
characterize the rock, ice, and gas properties of planetary bodies. The
planetary mass scale includes five mass classes with upper and lower mass
limits derived from recent studies of the exoplanet mass radius and mass
density relationships and the physical characteristics of planets, dwarf
planets, and spherical moons in the Solar System. The combined mass and
composition codes provide a geophysical classification that allows for
comparison of the global mass and composition characteristics of exoplanets
with the Solar System's planets, dwarf planets, and spherical moons. The system
is flexible and can be combined with additional codes characterizing other
physical, dynamical, or biological characteristics of planets.


title:
Heavy quark dynamics and hadronization in ultra-relativistic heavy-ion
  collisions: collisional versus radiative energy loss

abstract:
  We study the dynamics of energy loss and flow of heavy quarks produced in
ultra-relativistic heavy-ion collisions within the framework of a Langevin
equation coupled to a (2+1)-dimensional viscous hydrodynamic model that
simulates the space-time evolution of the produced hot and dense QCD matter.
The classical Langevin approach is improved such that, apart from quasi-elastic
scatterings, radiative energy loss is incorporated by treating gluon radiation
as an additional force term. The hadronization of emitted heavy quarks is
simulated via a hybrid fragmentation plus recombination model. Our calculation
shows significant contribution from gluon radiation to heavy quark energy loss
at high energies, and we find the recombination mechanism is important for
heavy flavor meson production at intermediate energies. We present numerical
results for the nuclear modification and elliptic flow of D mesons, which are
consistent with measurements at both LHC and RHIC; predictions for B mesons are
also provided.


title: Self-interacting Dark Matter Benchmarks

abstract:
  Dark matter self-interactions have important implications for the
distributions of dark matter in the Universe, from dwarf galaxies to galaxy
clusters. We present benchmark models that illustrate characteristic features
of dark matter that is self-interacting through a new light mediator. These
models have self-interactions large enough to change dark matter densities in
the centers of galaxies in accord with observations, while remaining compatible
with large-scale structure data and all astrophysical observations such as halo
shapes and the Bullet Cluster. These observations favor a mediator mass in the
10 - 100 MeV range and large regions of this parameter space are accessible to
direct detection experiments like LUX, SuperCDMS, and XENON1T.


title: Refined stable pair invariants for E-, M- and [p,q]-strings

abstract:
  We use mirror symmetry, the refined holomorphic anomaly equation and
modularity properties of elliptic singularities to calculate the refined BPS
invariants of stable pairs on non-compact Calabi-Yau manifolds, based on del
Pezzo surfaces and elliptic surfaces, in particular the half K3. The BPS
numbers contribute naturally to the five-dimensional N=1 supersymmetric index
of M-theory, but they can be also interpreted in terms of the superconformal
index in six dimensions and upon dimensional reduction the generating functions
count N=2 Seiberg-Witten gauge theory instantons in four dimensions. Using the
M/F-theory uplift the additional information encoded in the spin content can be
used in an essential way to obtain information about BPS states in physical
systems associated to small instantons, tensionless strings, gauge symmetry
enhancement in F-theory by [p,q]-strings as well as M-strings.


title: Equilibrium models of coronal loops that involve curvature and buoyancy

abstract:
  We construct magnetostatic models of coronal loops in which the
thermodynamics of the loop is fully consistent with the shape and geometry of
the loop. This is achieved by treating the loop as a thin, compact, magnetic
fibril that is a small departure from a force-free state. The density along the
loop is related to the loop's curvature by requiring that the Lorentz force
arising from this deviation is balanced by buoyancy. This equilibrium, coupled
with hydrostatic balance and the ideal gas law, then connects the temperature
of the loop with the curvature of the loop without resorting to a detailed
treatment of heating and cooling. We present two example solutions: one with a
spatially invariant magnetic Bond number (the dimensionless ratio of buoyancy
to Lorentz forces) and the other with a constant radius of curvature of the
loop's axis. We find that the density and temperature profiles are quite
sensitive to curvature variations along the loop, even for loops with similar
aspect ratios.


title: The Erd\H{o}s-Ko-Rado property for some 2-transitive groups

abstract:
  A subset of a group G of Sym(n) is intersecting if for any pair of
permutations $\pi,\sigma \in G$ there is an $i$ in {1,2,...,n} such that
$\pi(i) = \sigma(i)$. It has been shown, using an algebraic approach, that the
largest intersecting sets in each of Sym(n), Alt(n) and PGL(2,q) are exactly
the cosets of the point-stabilizers. In this paper, we show how this method can
be applied more generally to many 2-transitive groups. We then apply this
method to the Mathieu groups and to all 2-transtive groups with degree no more
than 20.


title: Optimizing directed self-assembled morphology

abstract:
  Directed assembly of block polymers is rapidly becoming a viable strategy for
lithographic patterning of nanoscopic features. One of the key attributes of
directed assembly is that an underlying chemical or topographic substrate
pattern used to direct assembly need not exhibit a direct correspondence with
the sought after block polymer morphology, and past work has largely relied on
trial-and-error approaches to design appropriate patterns. In this work, a
computational evolutionary strategy is proposed to solve this optimization
problem. By combining the Cahn-Hilliard equation, which is used to find the
equilibrium morphology, and the covariance-matrix evolutionary strategy, which
is used to optimize the combined outcome of particular substrate-copolymer
combinations, we arrive at an efficient method for design of substrates leading
to non-trivial, desirable outcomes.


title:
Asymptotic Cellular Growth Rate as the Effective Information Utilization
  Rate

abstract:
  We study the average asymptotic growth rate of cells in randomly fluctuating
environments, with multiple viable phenotypes per environment. We show that any
information processing strategy has an asymptotic growth rate, which is the sum
of: (i) the maximal growth rate at the worst possible distribution of
environments, (ii) relative information between the actual distribution of
environments to the worst one, and (iii) information utilization rate, which is
the information rate of the sensory devices minus the "information dissipation
rate", the amount of information not utilized by the cell for growth. In
non-stationary environments, we find that the optimal phenotypic switching
times equally partition the information dissipation rate between consecutive
switching intervals.


title:
A weighted L1-minimization approach for sparse polynomial chaos
  expansions

abstract:
  This work proposes a method for sparse polynomial chaos (PC) approximation of
high-dimensional stochastic functions based on non-adapted random sampling. We
modify the standard l1 -minimization algorithm, originally proposed in the
context of compressive sampling, using a priori information about the decay of
the PC coefficients and refer to the resulting algorithm as weighted l1
-minimization. We provide conditions under which we may guarantee recovery
using this weighted scheme. Numerical tests are used to compare the weighted
and non-weighted methods for the recovery of solutions to two differential
equations with high-dimensional random inputs: a boundary value problem with a
random elliptic operator and a 2-D thermally driven cavity flow with random
boundary condition.


title: TCP-Aware Backpressure Routing and Scheduling

abstract:
  In this work, we explore the performance of backpressure routing and
scheduling for TCP flows over wireless networks. TCP and backpressure are not
compatible due to a mismatch between the congestion control mechanism of TCP
and the queue size based routing and scheduling of the backpressure framework.
We propose a TCP-aware backpressure routing and scheduling that takes into
account the behavior of TCP flows. TCP-aware backpressure (i) provides
throughput optimality guarantees in the Lyapunov optimization framework, (ii)
gracefully combines TCP and backpressure without making any changes to the TCP
protocol, (iii) improves the throughput of TCP flows significantly, and (iv)
provides fairness across competing TCP flows.


title: Estimating the longest increasing sequence in polylogarithmic time

abstract:
  Finding the length of the longest increasing subsequence (LIS) is a classic
algorithmic problem. Let $n$ denote the size of the array. Simple $O(n\log n)$
algorithms are known for this problem. We develop a polylogarithmic time
randomized algorithm that for any constant $\delta > 0$, estimates the length
of the LIS of an array to within an additive error of $\delta n$. More
precisely, the running time of the algorithm is $(\log n)^c
(1/\delta)^{O(1/\delta)}$ where the exponent $c$ is independent of $\delta$.
Previously, the best known polylogarithmic time algorithms could only achieve
an additive $n/2$ approximation. With a suitable choice of parameters, our
algorithm also gives, for any fixed $\tau>0$, a multiplicative
$(1+\tau)$-approximation to the distance to monotonicity $\varepsilon_f$ (the
fraction of entries not in the LIS), whose running time is polynomial in
$\log(n)$ and $1/varepsilon_f$. The best previously known algorithm could only
guarantee an approximation within a factor (arbitrarily close to) 2.


title: A Galactic Ring of Minimum Stellar Density Near the Solar Orbit Radius

abstract:
  We analyse the secular effects of a long-lived Galactic spiral structure on
the stellar orbits with mean radii close to the corotation resonance. By
test-particle simulations and different spiral potential models with parameters
constrained on observations, we verified the formation of a minimum with
amplitude ~ 30% - 40% of the background disk stellar density at corotation.
Such minimum is formed by the secular angular momentum transfer between stars
and the spiral density wave on both sides of corotation. We demonstrate that
the secular loss (gain) of angular momentum and decrease (increase) of mean
orbital radius of stars just inside (outside) corotation can counterbalance the
opposite trend of exchange of angular momentum shown by stars orbiting the
librational points L_4/5 at the corotation circle. Such secular processes
actually allow steady spiral waves to promote radial migration across
corotation. We propose some observational evidences for the minimum stellar
density in the Galactic disk, such as its direct relation to the minimum in the
observed rotation curve of the Galaxy at the radius R ~ 9 kpc (for R_0 = 7.5
kpc), as well as its association with a minimum in the distribution of Galactic
radii of a sample of open clusters older than 1 Gyr. The closeness of the solar
orbit radius to the corotation resonance implies that the solar orbit lies
inside a ring of minimum surface density (stellar + gas). This also implies in
a correction to larger values for the estimated total mass of the Galactic
disk, and consequently, a greater contribution of the disk component to the
inner rotation curve of the Galaxy.


title: On the Entropies of Hypersurfaces with bounded mean curvature

abstract:
  We are interested in the impact of entropies on the geometry of a
hypersurface of a Riemannian manifold. In fact, we will be able to compare the
volume entropy of a hypersurface with that of the ambient manifold, provided
some geometric assumption are satisfied. This depends on the existence of an
embedded tube around such hypersurface. Among the consequences of our study of
the entropies, we point out some new answers to a question of do Carmo on
stable Euclidean hypersurfaces of constant mean curvature.


title:
Measurement of Spin-Orbit Misalignment and Nodal Precession for the
  Planet around Pre-Main-Sequence Star PTFO 8-8695 From Gravity Darkening

abstract:
  PTFO 8-8695b represents the first transiting exoplanet candidate orbiting a
pre-main-sequence star. We find that the unusual lightcurve shapes of PTFO
8-8695 can be explained by transits of a planet across an oblate,
gravity-darkened stellar disk. We simultaneously and self-consistently fit two
separate lightcurves observed in 2009 December and 2010 December. Our two
self-consistent fits yield M_p = 3.0 M_Jup and M_p = 3.6 M_Jup for assumed
stellar masses of M_* = 0.34 M_Sun and M_* = 0.44 M_Sun respectively. The two
fits have precession periods of 293 days and 581 days. These mass
determinations (consistent with previous upper limits) along with the strength
of the gravity-darkened precessing model together validate PTFO 8-8695b as just
the second Hot Jupiter known to orbit an M-dwarf. Our fits show a high degree
of spin-orbit misalignment in the PTFO 8-8695 system: 69 +/- 2 or 73.1 +/- 0.5
degrees, in the two cases. The large misalignment is consistent with the
hypothesis that planets become Hot Jupiters with random orbital plane
alignments early in a system's lifetime. We predict that as a result of the
highly misaligned, precessing system, the transits should disappear for months
at a time over the course of the system's precession period. The precessing,
gravity-darkened model also predicts other observable effects: changing orbit
inclination that could be detected by radial velocity observations, changing
stellar inclination that would manifest as varying v sin i, changing projected
spin-orbit alignment that could be seen by the Rossiter-McLaughlin effect,
changing transit shapes over the course of the precession, and differing
lightcurves as a function of wavelength. Our measured planet radii of 1.64
R_Jup and 1.68 R_Jup in each case are consistent with a young,
hydrogen-dominated planet that results from a hot-start formation mechanism.


title:
Large-scale analysis of the SDSS-III DR8 photometric luminous galaxies
  angular correlation function

abstract:
  We analyse the large-scale angular correlation function (ACF) of the CMASS
luminous galaxies (LGs), a photometric-redshift catalogue based on the Data
Release 8 (DR8) of the Sloan Digital Sky Survey-III. This catalogue contains
over $600 \, \, 000$ LGs in the range $0.45 \leq z \leq 0.65$, which was split
into four redshift shells of constant width. First, we estimate the constraints
on the redshift-space distortion (RSD) parameters $b\sigma_8$ and $f\sigma_8$,
where $b$ is the galaxy bias, $f$ the growth rate and $\sigma_8$ is the
normalization of the perturbations, finding that they vary appreciably among
different redshift shells, in agreement with previous results using DR7 data.
When assuming constant RSD parameters over the survey redshift range, we obtain
$f\sigma_8 = 0.69 \pm 0.21$, which agrees at the $1.5\sigma$ level with Baryon
Oscillation Spectroscopic Survey DR9 spectroscopic results. Next, we performed
two cosmological analyses, where relevant parameters not fitted were kept fixed
at their fiducial values. In the first analysis, we extracted the baryon
acoustic oscillation peak position for the four redshift shells, and combined
with the sound horizon scale from 7-year \textit{Wilkinson Microwave Anisotropy
Probe} $(WMAP7)$ to produce the constraints $\Omega_{m}=0.249 \pm 0.031$ and
$w=-0.885 \pm 0.145$. In the second analysis, we used the ACF full shape
information to constrain cosmology using real data for the first time, finding
$\Omega_{m} = 0.280 \pm 0.022$ and $f_b = \Omega_b/\Omega_m = 0.211 \pm 0.026$.
These results are in good agreement with $WMAP7$ findings, showing that the ACF
can be efficiently applied to constrain cosmology in future photometric galaxy
surveys.


title: Weyl groups of the fine gradings on $\e_6$

abstract:
  The Weyl groups of the fine gradings with infinite universal grading group on
$\mathfrak{e}_6$ are given.


title:
Zero-error Slepian-Wolf Coding of Confined Correlated Sources with
  Deviation Symmetry

abstract:
  In this paper, we use linear codes to study zero-error Slepian-Wolf coding of
a set of sources with deviation symmetry, where the sources are generalization
of the Hamming sources over an arbitrary field. We extend our previous codes,
Generalized Hamming Codes for Multiple Sources, to Matrix Partition Codes and
use the latter to efficiently compress the target sources. We further show that
every perfect or linear-optimal code is a Matrix Partition Code. We also
present some conditions when Matrix Partition Codes are perfect and/or
linear-optimal. Detail discussions of Matrix Partition Codes on Hamming sources
are given at last as examples.


title:
Magneto-Transport in MoS2: Phase Coherence, Spin Orbit Scattering and
  the Hall Factor

abstract:
  We have characterized phase coherence length, spin orbit scattering length,
and the Hall factor in n-type MoS2 2D crystals via weak localization
measurements and Hall-effect measurements. Weak localization measurements
reveal a phase coherence length of ~50 nm at T = 400 mK for a few-layer MoS2
film, decreasing as T^-1/2 with increased temperatures. Weak localization
measurements also allow us, for the first time without optical techniques, to
estimate the spin orbit scattering length to be 430 nm, pointing to the
potential of MoS2 for spintronics applications. Via Hall-effect measurements,
we observe a low temperature Hall mobility of 311 cm2/Vs at T = 1 K which
decreases as a power law with a characteristic exponent {\gamma}=1.5 from 10 K
to 60 K. At room temperature, we observe Hall mobility of 24 cm2/Vs. By
determining the Hall factor for MoS2 to be 1.35 at T = 1 K and 2.4 at room
temperature, we observe drift mobility of 420 cm2/Vs and 56 cm2/Vs at T = 1 K
and room temperature, respectively.


title: Stability of $N$-soliton molecules in dispersion-managed optical fibers

abstract:
  We investigate the stability of $N$-soliton molecules in dispersion-managed
optical fibers with focus on the recently realized 2- and 3-soliton molecules.
We calculate their binding energy using an averaged nonlinear Schr$\rm{\ddot
o}$dinger equation. A combination of variational and numerical solutions to
this equation shows that it describes well the intensity profiles and relative
separations of the experimental molecules. Extending the calculation to larger
values of $N$, the binding energy per soliton is found to saturate at N
$N\ge7$.


title:
Horizon instability of massless scalar perturbations of an extreme
  Reissner-Nordstr\"om-AdS black hole

abstract:
  We study the stability of extreme Reissner-Nordstr\"om-AdS black hole under
massless scalar perturbations. We show that the perturbation on the horizon of
the extreme Reissner-Nordstr\"om-AdS black hole experiences a power-law decay,
instead of an exponential decay as observed in the nonextreme AdS black hole.
On the horizon of the extreme Reissner-Nordstr\"om-AdS black hole, the blow up
happens at lower order derivative of the scalar field compared with that of the
extreme Reissner-Nordstr\"om black hole, which shows that extreme AdS black
holes tend to instability in comparison to black holes in asymptotic flat
space-times.


title: Stress-induced modification of the boson peak scaling behavior

abstract:
  The scaling behavior of the so-called boson peak in glass-formers and its
relation to the elastic properties of the system remains a source of
controversy. Here, the boson peak in a binary reactive mixture is measured by
Raman scattering (i) on cooling the unreacted mixture well below its glass
transition temperature and (ii) after quenching to very low temperature the
mixture at different times during isothermal polymerization. These different
paths to the glassy phase are able to generate glasses with different amounts
of residual stresses, as evidenced by the departure of the elastic moduli from
a Cauchy-like relationship. We find that the scaling behavior of the boson peak
with the properties of the elastic medium --- as measured by the Debye
frequency --- holds for states in which the system is able to release internal
stress and breaks down in the presence of residual stresses. These findings
provide new insight into the boson peak behavior and are able to reconcile the
apparently conflicting results presented in literature.


title: Riemannian foliations of bounded geometry

abstract:
  Continuing the study of bounded geometry for Riemannian foliations, begun by
Sanguiao, we introduce a chart-free definition of this concept. Our main
theorem states that it is equivalent to a condition involving certain normal
foliation charts. For this type of charts, it is also shown that the
derivatives of the changes of coordinates are uniformly bounded, and there are
nice partitions of unity. Applications to a trace formula for foliated flows
will given in a forthcoming paper.


title:
Reply to 'Comment on Universal out-of-equilibrium transport in
  Kondo-correlated quantum dots'

abstract:
  A recent comment on our work (Phys. Rev. Lett., vol. 110, 016601 (2013)) by
A.A.Aligia claims that we "made mistakes in the evaluation of the lesser
quantities". It is further claimed that the distribution function of the
single-particle selfenergy of the interacting region in the Fermi liquid
regime, e.g. at small bias voltage, low temperature, and small frequency, is
continuous. These claims are based on a comparison of the particle-hole
symmetric case with results obtained from the approach of A.A.Aligia. We
disagree with these claims and show that the discrepancies that the comment
alludes to originate from a violation of Ward identities by the method employed
in the comment. A comparison of our approach with the numerical renormalization
group shows perfect agreement for the symmetric case.


title: Rigidity for Quasi-M\"obius Actions on Fractal Metric Spaces

abstract:
  In \cite{BK02}, M. Bonk and B. Kleiner proved a rigidity theorem for
expanding quasi-M\"obius group actions on Ahlfors $n$-regular metric spaces
with topological dimension $n$. This led naturally to a rigidity result for
quasi-convex geometric actions on CAT$(-1)$-spaces that can be seen as a metric
analog to the "entropy rigidity" theorems of U. Hamenst\"adt and M. Bourdon.
Building on the ideas developed in \cite{BK02}, we establish a rigidity theorem
for certain expanding quasi-M\"obius group actions on spaces with different
metric and topological dimensions. This is motivated by a corresponding entropy
rigidity result in the coarse geometric setting.


title: Long time dynamics of forced critical SQG

abstract:
  We prove the existence of a compact global attractor for the dynamics of the
forced critical surface quasi-geostrophic equation (SQG) and prove that it has
finite fractal (box-counting) dimension. In order to do so we give a new proof
of global regularity for critical SQG. The main ingredient is the nonlinear
maximum principle in the form of a nonlinear lower bound on the fractional
Laplacian, which is used to bootstrap the regularity directly from $L^\infty$
to $C^\alpha$, without the use of De Giorgi techniques. We prove that for large
time, the norm of the solution measured in a sufficiently strong topology
becomes bounded with bounds that depend solely on norms of the force, which is
assumed to belong merely to $L^\infty \cap H^1$. Using the fact that the
solution is bounded independently of the initial data after a transient time,
in spaces conferring enough regularity, we prove the existence of a compact
absorbing set for the dynamics in $H^1$, obtain the compactness of the
linearization and the continuous differentiability of the solution map. We then
prove exponential decay of high yet finite dimensional volume elements in $H^1$
along solution trajectories, and use this property to bound the dimension of
the global attractor.


title: United Statistical Algorithm, Small and Big Data: Future OF Statistician

abstract:
  This article provides the role of big idea statisticians in future of Big
Data Science. We describe the `United Statistical Algorithms' framework for
comprehensive unification of traditional and novel statistical methods for
modeling Small Data and Big Data, especially mixed data (discrete, continuous).


title:
Nonlinear Time Series Modeling: A Unified Perspective, Algorithm, and
  Application

abstract:
  A new comprehensive approach to nonlinear time series analysis and modeling
is developed in the present paper. We introduce novel data-specific
mid-distribution based Legendre Polynomial (LP) like nonlinear transformations
of the original time series Y(t) that enables us to adapt all the existing
stationary linear Gaussian time series modeling strategy and made it applicable
for non-Gaussian and nonlinear processes in a robust fashion. The emphasis of
the present paper is on empirical time series modeling via the algorithm
LPTime. We demonstrate the effectiveness of our theoretical framework using
daily S&P 500 return data between Jan/2/1963 - Dec/31/2009. Our proposed LPTime
algorithm systematically discovers all the `stylized facts' of the financial
time series automatically all at once, which were previously noted by many
researchers one at a time.


title: The solution of the scalar wave equation in the exterior of a sphere

abstract:
  We derive new, explicit representations for the solution to the scalar wave
equation in the exterior of a sphere, subject to either Dirichlet or Robin
boundary conditions. Our formula leads to a stable and high-order numerical
scheme that permits the evaluation of the solution at an arbitrary target,
without the use of a spatial grid and without numerical dispersion error. In
the process, we correct some errors in the analytic literature concerning the
asymptotic behavior of the logarithmic derivative of the spherical modified
Hankel function. We illustrate the performance of the method with several
numerical examples.


title: Oscillations and Surface Rotation of Red Giant Stars

abstract:
  More than 15000 red giants observed by Kepler for a duration of almost one
year became public at the beginning of this year. We analysed a subsample of
416 stars to determine the global properties of acoustic modes (mean large
separation and frequency of maximum power). Using the effective temperature
from the Kepler Input Catalog, we derived a first estimation of the masses and
radii of these stars. Finally, we applied wavelets to look for signature of
surface rotation, which relies on the presence of spots or other surface
features crossing the stellar visible disk.


title: Study of stellar magnetic activity with CoRoT and Kepler data

abstract:
  Our knowledge of magnetic activity of stars is mostly based on the study of
the Sun and some spectroscopic surveys of a few hundreds of stars. However, the
detailed mechanisms of the solar magnetic activity cycle are not fully
understood. With the Kepler mission that is providing exquisite photometric
data for hundred of thousands of stars monitored continuously for more than
three year, we can study changes in the light curves that can be related to
magnetic activity. We show here a few examples of stars for which we did a
time-frequency analysis to look for such signature.


title: Calibrated Estimates of the Energy in Major Flares of GRS 1915+105

abstract:
  We analyze the energetics of the major radio flare of October 8 2005 in GRS
1915+105. The flare is of particular interest because it is one of the most
luminous and energetic radio flares from a Galactic black hole that has ever
been observed. The motivation is two-fold. One, to learn more about the
energetics of this most extreme phenomenon and its relationship to the
accretion state. The second is to verify if the calibrated estimates of the
energy of major radio flares (based on the peak low frequency optically thin
flux) derived from flares in the period 1996-2001 in Punsly & Rodriguez (2013),
PR13 hereafter, can be used to estimate plasmoid energy beyond this time
period. We find evidence that the calibrated curves are still accurate for this
strong flare. Furthermore, the physically important findings of PR13 are
supported by the inclusion of this flare: the flare energy is correlated with
both the intrinsic bolometric X-ray luminosity, $L_{\mathrm{bol}}$, $\sim 1$
hour before ejection and $L_{\mathrm{bol}}$ averaged over the duration of the
ejection of the plasmoid and $L_{\mathrm{bol}}$ is highly elevated relative to
historic levels just before and during the ejection episode. A search of the
data archives reveal that only the October 8 2005 flare and those in PR13 have
adequate data sampling to allow estimates of both the energy of the flare and
the X-ray luminosity before and during flare launch.


title: Asteroseismic analysis of the CoRoT target HD 169392

abstract:
  The satellite CoRoT (Convection, Rotation, and planetary Transits) has
provided high-quality data for almost six years. We show here the asteroseismic
analysis and modeling of HD169392A, which belongs to a binary system weakly
gravitationally bound as the distance between the two components is of 4250 AU.
The main component, HD169392A, is a G0IV star with a magnitude of 7.50 while
the second component is a G0V-G2IV star with a magnitude of 8.98. This analysis
focuses on the main component, as the secondary one is too faint to measure any
seismic parameters. A complete modeling has been possible thanks to the
complementary spectroscopic observations from HARPS, providing Teff=5985+/-60K,
log g=3.96+/-0.07, and [Fe/H]=- 0.04+/-0.10.


title:
Particle Concentration At Planet Induced Gap Edges and Vortices: I.
  Inviscid 3-D Hydro Disks

abstract:
  We perform a systematic study of the dynamics of dust particles in
protoplanetary disks with embedded planets using global 2-D and 3-D inviscid
hydrodynamic simulations. Lagrangian particles have been implemented into
magnetohydrodynamic code Athena with cylindrical coordinates. We find two
distinct outcomes depending on the mass of the embedded planet. In the presence
of a low mass planet ($8 M_{\oplus}$), two narrow gaps start to open in the gas
on each side of the planet where the density waves shock. These shallow gaps
can dramatically affect particle drift speed and cause significant, roughly
axisymmetric dust depletion. On the other hand, a more massive planet ($>0.1
M_{J}$) carves out a deeper gap with sharp edges, which are unstable to the
vortex formation. Particles with a wide range of sizes ($0.02<\Omega t_{s}<20$)
are trapped and settle to the midplane in the vortex, with the strongest
concentration for particles with $\Omega t_{s}\sim 1$. The dust concentration
is highly elongated in the $\phi$ direction, and can be as wide as 4 disk scale
heights in the radial direction. Dust surface density inside the vortex can be
increased by more than a factor of 10$^2$ in a very non-axisymmetric fashion.
For very big particles ($\Omega t_{s}\gg 1$) we find strong eccentricity
excitation, in particular around the planet and in the vicinity of the mean
motion resonances, facilitating gap opening there. Our results imply that in
weakly turbulent protoplanetary disk regions (e.g. the "dead zone") dust
particles with a very wide range of sizes can be trapped at gap edges and
inside vortices induced by planets with $M_{p}<M_{J}$, potentially accelerating
planetesimal and planet formation there, and giving rise to distinctive
features that can be probed by ALMA and EVLA.


title: Atoms which can bind positrons

abstract:
  Calculations of the positron binding energies to all atoms in the periodic
table are presented and atoms where the positron-atom binding actually exists
are identified. The results of these calculations and accurate calculations of
other authors (which existed for several atoms only) are used to evaluate
recommended values of the positron binding energies to the ground states of
atoms. We also present the recommended energies of the positron excited bound
levels and resonances (due to the binding of positron to excited states of
atoms) which can not emit positronium and have relatively narrow widths. Such
resonances in positron annihilation and scattering may be used to measure the
positron binding energy.


title:
Frequency Domain Min-Max Optimization of Noise-Shaping Delta-Sigma
  Modulators

abstract:
  This paper proposes a min-max design of noise-shaping delta-sigma modulators.
We first characterize the all stabilizing loop-filters for a linearized
modulator model. By this characterization, we formulate the design problem of
lowpass, bandpass, and multi-band modulators as minimization of the maximum
magnitude of the noise transfer function (NTF) in fixed frequency band(s). We
show that this optimization minimizes the worst-case reconstruction error, and
hence improves the SNR (signal-to-noise ratio) of the modulator. The
optimization is reduced to an optimization with a linear matrix inequality
(LMI) via the generalized KYP (Kalman-Yakubovich-Popov) lemma. The obtained NTF
is an FIR (finite-impulse-response) filter, which is favorable in view of
implementation. We also derive a stability condition for the nonlinear model of
delta-sigma modulators with general quantizers including uniform ones. This
condition is described as an H-infinity norm condition, which is reduced to an
LMI via the KYP lemma. Design examples show advantages of our design.


title:
Symmetric quiver Hecke algebras and R-matrices of quantum affine
  algebras II

abstract:
  Let $\g$ be an untwisted affine Kac-Moody algebra of type $A^{(1)}_n$ $(n \ge
1)$ or $D^{(1)}_n$ $(n \ge 4)$ and let $\g_0$ be the underlying
finite-dimensional simple Lie subalgebra of $\g$. For each Dynkin quiver $Q$ of
type $\g_0$, Hernandez and Leclerc (\cite{HL11}) introduced a tensor
subcategory $\CC_Q$ of the category of finite-dimensional integrable
$\uqpg$-modules and proved that the Grothendieck ring of $\CC_Q$ is isomorphic
to $\C [N]$, the coordinate ring of the unipotent group $N$ associated with
$\g_0$. We apply the generalized quantum affine Schur-Weyl duality introduced
in \cite{KKK13} to construct an exact functor $\F$ from the category of
finite-dimensional graded $R$-modules to the category $\CC_Q$, where $R$
denotes the symmetric quiver Hecke algebra associated to $\g_0$. We prove that
the homomorphism induced by the functor $\F$ coincides with the homomorphism of
Hernandez and Leclerc and show that the functor $\F$ sends the simple modules
to the simple modules.


title: Efficient immunization strategies to prevent financial contagion

abstract:
  Many immunization strategies have been proposed to prevent infectious viruses
from spreading through a network. In this study, we propose efficient
immunization strategies to prevent a default contagion that might occur in a
financial network. An essential difference from the previous studies on
immunization strategy is that we take into account the possibility of serious
side effects. Uniform immunization refers to a situation in which banks are
"vaccinated" with a common low-risk asset. The riskiness of immunized banks
will decrease significantly, but the level of systemic risk may increase due to
the de-diversification effect. To overcome this side effect, we propose another
immunization strategy, counteractive immunization, which prevents pairs of
banks from failing simultaneously. We find that counteractive immunization can
efficiently reduce systemic risk without altering the riskiness of individual
banks.


title:
Polar coordinate lattice Boltzmann kinetic modeling of detonation
  phenomena

abstract:
  A novel polar coordinate lattice Boltzmann kinetic model for detonation
phenomena is presented and applied to investigate typical implosion and
explosion processes. In this model, the change of discrete distribution
function due to local chemical reaction is dynamically coupled into in the
modified lattice Boltzmann equation, which could recovery the Navier-Stokes
equations, including contribution of chemical reaction, via the Chapman-Enskog
expansion. For the numerical investigations, the main focuses are the
nonequilibrium behaviors in these processes. The system at the disc center is
always in its thermodynamic equilibrium. The internal kinetic energies in
different degrees freedoms around the detonation front do not coincide due to
the fluid viscosity. They show the maximum difference at the inflexion point
where the pressure has the largest spatial derivative. The dependence of the
reaction rate on the pressure, influences of the shock strength and reaction
rate on the departure amplitude of the system from its local thermodynamic
equilibrium are probed.


title: Golden Ratio Controlled Chaos in Supersymmetric Dynamics

abstract:
  We construct supersymmetric Lagrangians for the recently constructed
off-shell worldline N=3 supermultiplet $Y_I/(i D_I X)$ for I=1,2,3, where $Y_I$
and $X$ are standard, Salam-Strathdee superfields: $Y_I$ fermionic and $X$
bosonic. Already the Lagrangian bilinear in component fields exhibits a total
of thirteen free parameters, seven of which specify Zeeman-like coupling to
external (magnetic) fluxes. All but special subsets of this parameter space
describe aperiodic oscillatory response, some of which are controlled by the
"golden ratio," $\varphi\approx1.61803$. We also show that all of these
Lagrangians admit an $N=3\to 4$ supersymmetry extension, while a subset admits
two inequivalent such extensions.


title:
An empirical evaluation of four variants of a universal species-area
  relationship

abstract:
  The Maximum Entropy Theory of Ecology (METE) predicts a universal
species-area relationship (SAR) that can be fully characterized using only the
total abundance (N) and species richness (S) at a single spatial scale. This
theory has shown promise for characterizing scale dependence in the SAR.
However, there are currently four different approaches to applying METE to
predict the SAR and it is unclear which approach should be used due to a lack
of empirical evaluation. Specifically, METE can be applied recursively or a
non-recursively and can use either a theoretical or observed species-abundance
distribution (SAD). We compared the four different combinations of approaches
using empirical data from 16 datasets containing over 1000 species and 300,000
individual trees and herbs. In general, METE accurately downscaled the SAR
(R^2> 0.94), but the recursive approach consistently under-predicted richness,
and METEs accuracy did not depend strongly on using the observed or predicted
SAD. This suggests that best approach to scaling diversity using METE is to use
a combination of non-recursive scaling and the theoretical abundance
distribution, which allows predictions to be made across a broad range of
spatial scales with only knowledge of the species richness and total abundance
at a single scale.


title:
Declarative Ajax Web Applications through SQL++ on a Unified Application
  State

abstract:
  Implementing even a conceptually simple web application requires an
inordinate amount of time. FORWARD addresses three problems that reduce
developer productivity: (a) Impedance mismatch across the multiple languages
used at different tiers of the application architecture. (b) Distributed data
access across the multiple data sources of the application (SQL database, user
input of the browser page, session data in the application server, etc). (c)
Asynchronous, incremental modification of the pages, as performed by Ajax
actions.
  FORWARD belongs to a novel family of web application frameworks that attack
impedance mismatch by offering a single unifying language. FORWARD's language
is SQL++, a minimally extended SQL. FORWARD's architecture is based on two
novel cornerstones: (a) A Unified Application State (UAS), which is a virtual
database over the multiple data sources. The UAS is accessed via distributed
SQL++ queries, therefore resolving the distributed data access problem. (b)
Declarative page specifications, which treat the data displayed by pages as
rendered SQL++ page queries. The resulting pages are automatically
incrementally modified by FORWARD. User input on the page becomes part of the
UAS.
  We show that SQL++ captures the semi-structured nature of web pages and
subsumes the data models of two important data sources of the UAS: SQL
databases and JavaScript components. We show that simple markup is sufficient
for creating Ajax displays and for modeling user input on the page as UAS data
sources. Finally, we discuss the page specification syntax and semantics that
are needed in order to avoid race conditions and conflicts between the user
input and the automated Ajax page modifications.
  FORWARD has been used in the development of eight commercial and academic
applications. An alpha-release web-based IDE (itself built in FORWARD) enables
development in the cloud.


title: Metropolis-Hastings Sampling Using Multivariate Gaussian Tangents

abstract:
  We present MH-MGT, a multivariate technique for sampling from
twice-differentiable, log-concave probability density functions. MH-MGT is
Metropolis-Hastings sampling using asymmetric, multivariate Gaussian proposal
functions constructed from Taylor-series expansion of the log-density function.
The mean of the Gaussian proposal function represents the full Newton step, and
thus MH-MGT is the stochastic counterpart to Newton optimization. Convergence
analysis shows that MH-MGT is well suited for sampling from
computationally-expensive log-densities with contributions from many
independent observations. We apply the technique to Gibbs sampling analysis of
a Hierarchical Bayesian marketing effectiveness model built for a large US
foodservice distributor. Compared to univariate slice sampling, MH-MGT shows 6x
improvement in sampling efficiency, measured in terms of `function evaluation
equivalents per independent sample'. To facilitate wide applicability of MH-MGT
to statistical models, we prove that log-concavity of a twice-differentiable
distribution is invariant with respect to 'linear-projection' transformations
including, but not restricted to, generalized linear models.


title:
Exploring The Contribution of Unlabeled Data in Financial Sentiment
  Analysis

abstract:
  With the proliferation of its applications in various industries, sentiment
analysis by using publicly available web data has become an active research
area in text classification during these years. It is argued by researchers
that semi-supervised learning is an effective approach to this problem since it
is capable to mitigate the manual labeling effort which is usually expensive
and time-consuming. However, there was a long-term debate on the effectiveness
of unlabeled data in text classification. This was partially caused by the fact
that many assumptions in theoretic analysis often do not hold in practice. We
argue that this problem may be further understood by adding an additional
dimension in the experiment. This allows us to address this problem in the
perspective of bias and variance in a broader view. We show that the well-known
performance degradation issue caused by unlabeled data can be reproduced as a
subset of the whole scenario. We argue that if the bias-variance trade-off is
to be better balanced by a more effective feature selection method unlabeled
data is very likely to boost the classification performance. We then propose a
feature selection framework in which labeled and unlabeled training samples are
both considered. We discuss its potential in achieving such a balance. Besides,
the application in financial sentiment analysis is chosen because it not only
exemplifies an important application, the data possesses better illustrative
power as well. The implications of this study in text classification and
financial sentiment analysis are both discussed.


title: Barrierless Reactions in Solution: An Analytically Solvable Model

abstract:
  We propose an analytical method for solving the problem of barrierless
reactions in solution, modeled by a particle undergoing diffusive motion under
the influence of both reactant and product potentials. The coupling between
these two potentials is taken to be a Dirac Delta function. The diffusive
motion in this paper is described by the Smoluchowskii equation. Our solution
requires only the knowledge of the Laplace transform of the Green's function
for the motion in both the uncoupled potentials. Our model is more general than
all the earlier models, because we are the first one to consider the potential
energy surfaces of both the reactant and product explicitly.


title: Monte Carlo simulation of classical spin models with chaotic billiards

abstract:
  It has recently been shown that the computing abilities of Boltzmann
machines, or Ising spin-glass models, can be implemented by chaotic billiard
dynamics without any use of random numbers. In this paper, we further
numerically investigate the capabilities of the chaotic billiard dynamics as a
deterministic alternative to random Monte Carlo methods by applying it to
classical spin models in statistical physics. First, we verify that the
billiard dynamics can yield samples that converge to the true distribution of
the Ising model on a small lattice, and we show that it appears to have the
same convergence rate as random Monte Carlo sampling. Second, we apply the
billiard dynamics to finite-size scaling analysis of the critical behavior of
the Ising model and show that the phase transition point and the critical
exponents are correctly obtained. Third, we extend the billiard dynamics to
spins that take more than two states and show that it can be applied
successfully to the Potts model. We also discuss the possibility of extensions
to continuous-valued models such as the XY model.


title:
A Comparison of Named Entity Recognition Tools Applied to Biographical
  Texts

abstract:
  Named entity recognition (NER) is a popular domain of natural language
processing. For this reason, many tools exist to perform this task. Amongst
other points, they differ in the processing method they rely upon, the entity
types they can detect, the nature of the text they can handle, and their
input/output formats. This makes it difficult for a user to select an
appropriate NER tool for a specific situation. In this article, we try to
answer this question in the context of biographic texts. For this matter, we
first constitute a new corpus by annotating Wikipedia articles. We then select
publicly available, well known and free for research NER tools for comparison:
Stanford NER, Illinois NET, OpenCalais NER WS and Alias-i LingPipe. We apply
them to our corpus, assess their performances and compare them. When
considering overall performances, a clear hierarchy emerges: Stanford has the
best results, followed by LingPipe, Illionois and OpenCalais. However, a more
detailed evaluation performed relatively to entity types and article categories
highlights the fact their performances are diversely influenced by those
factors. This complementarity opens an interesting perspective regarding the
combination of these individual tools in order to improve performance.


title: Severi-Bouligand tangents, Frenet frames and Riesz spaces

abstract:
  It was recently proved that a compact set $X\subseteq \mathbb R^2$ has an
outgoing Severi-Bouligand tangent vector $u\not=0$ at $x\in X$ iff some
principal ideal of the Riesz space $\mathcal R(X)$ of piecewise linear
functions on $X$ is not an intersection of maximal ideals. "Outgoing" means
$X\cap [x,x+u]=\{x\}$.
  Suppose now $X\subseteq \mathbb{R}^n$ and some principal ideal of $\mathcal
R(X)$ is not an intersection of maximal ideals. We prove that this is
equivalent to saying that $X$ contains a sequence $\{x_i\}$ whose Frenet
$k$-frame $(u_1,\ldots,u_k)$ is an outgoing Severi-Bouligand tangent of $X$.
When the $\{x_i\}$ are taken as sample points of a smooth curve $\gamma,$ the
Frenet $k$-frames of $\{x_i\}$ and of $\gamma$ coincide. The computation of
Frenet frames via sample sequences does not require the knowledge of any
higher-order derivative of $\gamma$.


title: A free product formula for the sofic dimension

abstract:
  It is proved that if $G=G_1*_{G_3}G_2$ is free product of probability measure
preserving $s$-regular ergodic discrete groupoids amalgamated over an amenable
subgroupoid $G_3$, then the sofic dimension $s(G)$ satisfies the equality \[
s(G)=\h(G_1^0)s(G_1)+\h(G_2^0)s(G_2)-\h(G_3^0)s(G_3) \] where $\h$ is the
normalized Haar measure on $G$.