title: New algorithms and lower bounds for circuits with linear threshold gates

abstract:
  Let $ACC \circ THR$ be the class of constant-depth circuits comprised of AND,
OR, and MOD$m$ gates (for some constant $m > 1$), with a bottom layer of gates
computing arbitrary linear threshold functions. This class of circuits can be
seen as a "midpoint" between $ACC$ (where we know nontrivial lower bounds) and
depth-two linear threshold circuits (where nontrivial lower bounds remain
open).
  We give an algorithm for evaluating an arbitrary symmetric function of
$2^{n^{o(1)}}$ $ACC \circ THR$ circuits of size $2^{n^{o(1)}}$, on all possible
inputs, in $2^n \cdot poly(n)$ time. Several consequences are derived:
  $\bullet$ The number of satisfying assignments to an $ACC \circ THR$ circuit
of subexponential size can be computed in $2^{n-n^{\varepsilon}}$ time (where
$\varepsilon > 0$ depends on the depth and modulus of the circuit).
  $\bullet$ $NEXP$ does not have quasi-polynomial size $ACC \circ THR$
circuits, nor does $NEXP$ have quasi-polynomial size $ACC \circ SYM$ circuits.
Nontrivial size lower bounds were not known even for $AND \circ OR \circ THR$
circuits.
  $\bullet$ Every 0-1 integer linear program with $n$ Boolean variables and $s$
linear constraints is solvable in $2^{n-\Omega(n/((\log M)(\log s)^{5}))}\cdot
poly(s,n,M)$ time with high probability, where $M$ upper bounds the bit
complexity of the coefficients. (For example, 0-1 integer programs with weights
in $[-2^{poly(n)},2^{poly(n)}]$ and $poly(n)$ constraints can be solved in
$2^{n-\Omega(n/\log^6 n)}$ time.)
  We also present an algorithm for evaluating depth-two linear threshold
circuits (a.k.a., $THR \circ THR$) with exponential weights and $2^{n/24}$ size
on all $2^n$ input assignments, running in $2^n \cdot poly(n)$ time. This is
evidence that non-uniform lower bounds for $THR \circ THR$ are within reach.


title:
Polar Confinement of Saturn's Magnetosphere Revealed by in-situ Cassini
  Observations

abstract:
  Plasma rotation plays a large role in determining the size and shape of
Saturn's disc-like magnetosphere. A magnetosphere more confined to the equator
in the polar regions is expected as a result of the interaction between this
type of obstacle and the solar wind. In addition, at times away from equinox, a
north-south asymmetry is expected where the magnetopause will be further
confined in one hemisphere but less confined in the opposite hemisphere.
Examining the extent of this confinement has been limited by a lack of
high-latitude spacecraft observations. Here, for the first time, direct
evidence for polar confinement of Saturn's magnetopause has been observed using
in-situ data obtained by the Cassini spacecraft during a series of
high-inclination orbits between 2007 and 2009. Following techniques established
by previous authors, we assume an equilibrium between the solar wind dynamic
pressure (which Cassini is generally unable to measure directly), and the
magnetic plus plasma pressure inside the magnetosphere. This assumption thus
allows us to estimate the upstream solar wind dynamic pressure ($D_P$) for a
series of magnetopause crossings, and hence to determine the expected location
and global shape of the magnetopause as a function of $D_P$. A clear divergence
from the familiar axisymmetric models of the magnetosphere is observed which
may be characterised by an 'apparent flattening parameter' of 0.81+0.03/-0.06
(representing a simple dilation of the nominal axisymmetric boundary along the
$Z_{KSM}$ axis such that the extent is reduced by 19% in this direction). This
figure is insensitive to variations in $D_P$.


title:
Surface atmospheric pressure excitation of the translational mode of the
  inner core

abstract:
  Using hourly atmospheric surface pressure field from ECMWF (European Centre
for Medium-Range Weather Forecasts) and from NCEP (National Centers for
Environmental Prediction) Climate Forecast System Reanalysis (CFSR) models, we
show that atmospheric pressure fluctuations excite the translational
oscillation of the inner core, the so-called Slichter mode, to the sub-nanogal
level at the Earth surface. The computation is performed using a normal-mode
formalism for a spherical, self-gravitating anelastic PREM-like Earth model. We
determine the statistical response in the form of power spectral densities of
the degree-one spherical harmonic components of the observed pressure field.
Both hypotheses of inverted and non-inverted barometer for the ocean response
to pressure forcing are considered. Based on previously computed noise levels,
we show that the surface excitation amplitude is below the limit of detection
of the superconducting gravimeters, making the Slichter mode detection a
challenging instrumental task for the near future.


title:
Higher-order electroweak corrections to the partial widths and branching
  ratios of the Z boson

abstract:
  Recently, the calculation of fermionic electroweak two-loop corrections to
the total width of the Z boson and hadronic Z-peak cross-section in the
Standard Model has been presented in arXiv:1310.2256, where "fermionic" refers
to diagrams with closed fermion loops. Here, these results are complemented by
presenting contributions of the same order for the Z-boson partial widths,
which are the last missing pieces for a complete description of Z-pole physics
at the fermionic two-loop order. The definition of the relevant observables and
the calculational techniques are described in detail. Numerical results are
presented conveniently in terms of simple parametrization formulae. Finally,
the remaining theoretical uncertainties from missing higher-order corrections
are analyzed and found to be small compared to the current experimental errors.


title:
A 4D synchrotron X-ray tomography study of the formation of hydrocarbon
  migration pathways in heated organic-rich shale

abstract:
  Recovery of oil from oil shales and the natural primary migration of
hydrocarbons are closely related processes that have received renewed interests
in recent years because of the ever tightening supply of conventional
hydrocarbons and the growing production of hydrocarbons from low permeability
tight rocks. Quantitative models for conversion of kerogen into oil and gas and
the timing of hydrocarbon generation have been well documented. However, lack
of consensus about the kinetics of hydrocarbon formation in source rocks,
expulsion timing and how the resulting hydrocarbons escape from or are retained
in the source rocks motivates further investigation. In particular, many
mechanisms for the transport of hydrocarbons from the source rocks in which
they are generated into adjacent rocks with higher permeabilities and smaller
capillary entry pressures have been proposed, and a better understanding of
this complex process (primary migration) is needed. To characterize these
processes it is imperative to use the latest technological advances. In this
study, it is shown how insights into hydrocarbon migration in source rocks can
be obtained by using sequential high resolution synchrotron X-ray tomography.
Three-dimensional (3D) images of several immature "shale" samples were
constructed at resolutions close to 5 micrometers. This is sufficient to
resolve the source rock structure down to the grain level, but very fine
grained silt particles, clay particles and colloids cannot be resolved. Samples
used in this investigation came from the R-8 unit in the upper part of the
Green River Shale, which is organic rich, varved, lacustrine marl formed in
Eocene Lake Uinta, United States of America. One Green River Shale sample was
heated in-situ up to 400{\deg}C as X-ray tomography images were recorded. The
other samples were scanned before and after heating at 400{\deg}C. During the
heating phase, the organic matter was decomposed, and gas was released. Gas
expulsion from the low permeability shales was coupled with formation of
microcracks. The main technical difficulty was numerical extraction of
microcracks that have apertures in the 5 to 30 micrometer range (with 5
micrometers being the resolution limit) from a large 3D volume of X-ray
attenuation data. The main goal of the work presented here is to develop a
methodology to process these 3D data and image the cracks. This methodology is
based on several levels of spatial filtering and automatic recognition of
connected domains. Supportive petrographic and thermogravimetric data were an
important complement to this study. An investigation of the strain field using
two-dimensional image correlation analyses was also performed. As one
application of the four-dimensional (4D, space + time) microtomography and the
developed workflow, we show that fluid generation was accompanied by crack
formation. Under different conditions, in the subsurface, this might provide
paths for primary migration.


title: Flat rank 2 vector bundles on genus 2 curves

abstract:
  We study the moduli space of trace-free irreducible rank 2 holomorphic
connections over a complex projective curve of genus 2 and the forgetful map
towards the moduli space of underlying vector bundles (including unstable
bundles), for which we compute a natural Lagrangian rational section. As a
particularity of the genus $2$ case, connections as above are invariant under
the hyperelliptic involution : they descend as rank $2$ logarithmic connections
over the Riemann sphere. We establish explicit links between the well-known
moduli space of the underlying parabolic bundles with the classical approaches
by Narasimhan-Ramanan, Tyurin and Bertram. This allow us to explain a certain
number of geometric phenomena in the considered moduli spaces such as the
classical $(16,6)$-configuration of the Kummer surface. We also recover a
Poincar\'e family due to Bolognesi on a degree 2 cover of the
Narasimhan-Ramanan moduli space. We explicitly compute the Hitchin integrable
system on the moduli space of Higgs bundles and compare the Hitchin
Hamiltonians with those found by vanGeemen-Previato. We explicitly describe the
isomonodromic foliation in the moduli space of vector bundles with
$\mathfrak{sl}_2({\mathbb C})$-connection over curves of genus 2 and prove the
transversality of the induced flow with the locus of unstable bundles.


title: A slave mode expansion for obtaining ab-initio interatomic potentials

abstract:
  Here we propose a new approach for performing a Taylor series expansion of
the first-principles computed energy of a crystal as a function of the nuclear
displacements. We enlarge the dimensionality of the existing displacement space
and form new variables (ie. slave modes) which transform like irreducible
representations of the space group and satisfy homogeneity of free space.
Standard group theoretical techniques can then be applied to deduce the
non-zero expansion coefficients a priori. At a given order, the translation
group can be used to contract the products and eliminate terms which are not
linearly independent, resulting in a final set of slave mode products. While
the expansion coefficients can be computed in a variety of ways, we demonstrate
that finite difference is effective up to fourth order. We demonstrate the
power of the method in the strongly anharmonic system PbTe. All anharmonic
terms within an octahedron are computed up to fourth order. A proper unitary
transformation demonstrates that the vast majority of the anharmonicity can be
attributed to just two terms, indicating that a minimal model of phonon
interactions is achievable. The ability to straightforwardly generate
polynomial potentials will allow precise simulations at length and time scales
which were previously unrealizable.


title: Online Matrix Completion Through Nuclear Norm Regularisation

abstract:
  It is the main goal of this paper to propose a novel method to perform matrix
completion on-line. Motivated by a wide variety of applications, ranging from
the design of recommender systems to sensor network localization through
seismic data reconstruction, we consider the matrix completion problem when
entries of the matrix of interest are observed gradually. Precisely, we place
ourselves in the situation where the predictive rule should be refined
incrementally, rather than recomputed from scratch each time the sample of
observed entries increases. The extension of existing matrix completion methods
to the sequential prediction context is indeed a major issue in the Big Data
era, and yet little addressed in the literature. The algorithm promoted in this
article builds upon the Soft Impute approach introduced in Mazumder et al.
(2010). The major novelty essentially arises from the use of a randomised
technique for both computing and updating the Singular Value Decomposition
(SVD) involved in the algorithm. Though of disarming simplicity, the method
proposed turns out to be very efficient, while requiring reduced computations.
Several numerical experiments based on real datasets illustrating its
performance are displayed, together with preliminary results giving it a
theoretical basis.


title:
Center manifolds for partially hyperbolic set without strong unstable
  connections

abstract:
  We consider compact sets which are invariant and partially hyperbolic under
the dynamics of a diffeomorphism of a manifold. We prove that such a set K is
contained in a locally invariant center submanifold if and only if each strong
stable and strong unstable leaf intersects K at exactly one point.


title: Hyperbolic metamaterials: fundamentals and applications

abstract:
  Metamaterials are nano-engineered media with designed properties beyond those
available in nature with applications in all aspects of materials science. In
particular, metamaterials have shown promise for next generation of optical
materials with electromagnetic responses that cannot be obtained from
conventional media. We review the fundamental properties of metamaterials with
hyperbolic dispersion and present the various applications where such media
offer potential for transformative impact. These artificial materials support
unique bulk electromagnetic states which can tailor light-matter interaction at
the nanoscale. We present a unified view of current research in the field of
hyperbolic metamaterials such as sub-wavelength imaging and broadband photonic
density of states engineering. The review introduces the concepts central to
the theory of hyperbolic media as well as nanofabrication and characterization
details essential to experimentalists. Finally, we outline the challenges in
the area and offer a set of directions for future work.


title: Stretching Stretch

abstract:
  We give a generalized definition of stretch that simplifies the efficient
construction of low-stretch embeddings suitable for graph algorithms. The
generalization, based on discounting highly stretched edges by taking their
$p$-th power for some $0 < p < 1$, is directly related to performances of
existing algorithms. This discounting of high-stretch edges allows us to treat
many classes of edges with coarser granularity. It leads to a two-pass approach
that combines bottom-up clustering and top-down decompositions to construct
these embeddings in $\mathcal{O}(m\log\log{n})$ time. Our algorithm
parallelizes readily and can also produce generalizations of low-stretch
subgraphs.


title: CANDELS Visual Classifications: Scheme, Data Release, and First Results

abstract:
  We have undertaken an ambitious program to visually classify all galaxies in
the five CANDELS fields down to H<24.5 involving the dedicated efforts of 65
individual classifiers. Once completed, we expect to have detailed
morphological classifications for over 50,000 galaxies up to z<4 over all the
fields. Here, we present our detailed visual classification scheme, which was
designed to cover a wide range of CANDELS science goals. This scheme includes
the basic Hubble sequence types, but also includes a detailed look at mergers
and interactions, the clumpiness of galaxies, $k$-corrections, and a variety of
other structural properties. In this paper, we focus on the first field to be
completed -- GOODS-S. The wide area coverage spanning the full field includes
7634 galaxies that have been classified by at least three different people. In
the deep area of the field, 2534 galaxies have been classified by at least five
different people at three different depths. With this paper, we release to the
public all of the visual classifications in GOODS-S along with the GUI that we
developed to classify galaxies. We find that the level of agreement among
classifiers is good and depends on both the galaxy magnitude and the galaxy
type, with disks showing the highest level of agreement and irregulars the
lowest. A comparison of our classifications with the Sersic index and
rest-frame colors shows a clear separation between disk and spheroid
populations. Finally, we explore morphological k-corrections between the V-band
and H-band observations and find that a small fraction (84 galaxies in total)
are classified as being very different between these two bands. These galaxies
typically have very clumpy and extended morphology or are very faint in the
V-band.


title: Kinetic equation for spatially averaged molecular dynamics

abstract:
  We obtain a kinetic description of spatially averaged dynamics of particle
systems. Spatial averaging is one of the three types of averaging relevant
within the Irwing-Kirkwood procedure (IKP), a general method for deriving
macroscopic equations from molecular models. The other two types, ensemble
averaging and time averaging, have been extensively studied, while spatial
averaging is relatively less understood. We show that the average density,
linear momentum, and kinetic energy used in IKP can be obtained from a single
average quantity, called the generating function. A kinetic equation for the
generating function is obtained and tested numerically on Lennard-Jones
oscillator chains.


title: Composite Higgses

abstract:
  We present an overview of composite Higgs models in light of the discovery of
the Higgs boson. The small value of the physical Higgs mass suggests that the
Higgs quartic is likely loop generated, thus models with tree-level quartics
will generically be more tuned. We classify the various models (including bona
fide composite Higgs, little Higgs, holographic composite Higgs, twin Higgs and
dilatonic Higgs) based on their predictions for the Higgs potential, review the
basic ingredients of each of them, and quantify the amount of tuning needed,
which is not negligible in any model. We explain the main ideas for generating
flavor structure and the main mechanisms for protecting against large flavor
violating effects, and present a summary of the various coset models that can
result in realistic pseudo-Goldstone Higgses. We review the current
experimental status of such models by discussing the electroweak precision,
flavor and direct search bounds, and comment on UV completions and on ways to
incorporate dark matter.


title:
Jumping the Gap: The Formation Conditions and Mass Function of
  Pebble-Pile Planetesimals

abstract:
  In a turbulent proto-planetary disk, dust grains undergo large density
fluctuations and under the right circumstances, these grain overdensities can
overcome shear, turbulent, and gas pressure support to collapse under
self-gravity (forming a "pebble pile" planetesimal). Using a simple analytic
model for the fluctuations predicted in simulations, we estimate the
rate-of-formation and mass function of self-gravitating, rapidly-collapsing
planetesimal-mass bodies formed by this mechanism. The statistics of this
process depend sensitively on the size/stopping time of the grains, disk
surface density, and turbulent Mach numbers. However, when it occurs, we
predict that the resulting planetesimal mass function is broad and
quasi-universal, with a slope dN/dM~1/M^(1-2), spanning a size/mass range
~10-1e4 km (~1e-9-5.0 M_Earth). Collapse to planetesimal through super-Earth
masses is possible. The key condition is that grain density fluctuations reach
large amplitudes on large scales, where gravitational instability proceeds most
easily (collapse of small grains is strongly suppressed by turbulent
vorticity). We show this leads to a new criterion for 'pebble-pile' formation
in terms of the dimensionless particle stopping time (tau_stop > f(Q,Z,alpha)).
In a MMSN, this requires grains larger than a=(50,1,0.1)cm at r=(1,30,100)au.
At small radii, it would depend on the existence of large boulders. However,
because density fluctuations depend super-exponentially on tau_stop (inversely
proportional to disk surface density), lower-density disks are more unstable.
In fact, we predict that cm-sized grains at ~1au will form pebble piles in a
disk with ~10% the MMSN density, so planet formation at ~au may generically
occur late, as disks are evaporating. We also predict that conditions become
progressively more favorable for pebble-pile formation around lower-mass,
cooler stars.


title: Baryogenesis through Neutrino Oscillations: A Unified Perspective

abstract:
  Baryogenesis through neutrino oscillations is an elegant mechanism which has
found several realizations in the literature corresponding to different parts
of the model parameter space. Its appeal stems from its minimality and
dependence only on physics below the weak scale. In this work we show that, by
focusing on the physical time scales of leptogenesis instead of the model
parameters, a more comprehensive picture emerges. The different regimes
previously identified can be understood as different relative orderings of
these time scales. This approach also shows that all regimes require a
coincidence of time scales and this in turn translates to a certain tuning of
the parameters, whether in mass terms or Yukawa couplings. Indeed, we show that
the amount of tuning involved in the minimal model is never less than one part
in 10^5. Finally, we explore an extended model where the tuning can be removed
in exchange for the introduction of a new degree of freedom in the form of a
leptophilic Higgs with a vacuum expectation value of the order of GeV.


title:
Environmental dependence of bulge-dominated galaxy sizes in hierarchical
  models of galaxy formation. Comparison with the local Universe

abstract:
  We compare state-of-the-art semi-analytic models of galaxy formation as well
as advanced sub-halo abundance matching models with a large sample of
early-type galaxies from SDSS at z < 0.3. We focus our attention on the
dependence of median sizes of central galaxies on host halo mass. The data do
not show any difference in the structural properties of early-type galaxies
with environment, at fixed stellar mass. All hierarchical models considered in
this work instead tend to predict a moderate to strong environmental
dependence, with the median size increasing by a factor of about 1.5-3 when
moving from low to high mass host haloes. At face value the discrepancy with
the data is highly significant, especially at the cluster scale, for haloes
above log Mhalo > 14. The convolution with (correlated) observational errors
reduces some of the tension. Despite the observational uncertainties, the data
tend to disfavour hierarchical models characterized by a relevant contribution
of disc instabilities to the formation of spheroids, strong gas dissipation in
(major) mergers, short dynamical friction timescales, and very short quenching
timescales in infalling satellites. We also discuss a variety of additional
related issues, such as the slope and scatter in the local size-stellar mass
relation, the fraction of gas in local early-type galaxies, and the general
predictions on satellite galaxies.


title: Antihelium from Dark Matter

abstract:
  Cosmic-ray anti-nuclei provide a promising discovery channel for the indirect
detection of particle dark matter. Hadron showers produced by the
pair-annihilation or decay of Galactic dark matter generate anti-nucleons which
can in turn form light anti-nuclei. Previous studies have only focused on the
spectrum and flux of low energy antideuterons which, although very rarely, are
occasionally also produced by cosmic-ray spallation. Heavier elements
($A\geq3$) have instead entirely negligible astrophysical background and a
primary yield from dark matter which could be detectable by future experiments.
Using a Monte Carlo event generator and an event-by-event phase space analysis,
we compute, for the first time, the production spectrum of \antihe and \antiT
for dark matter annihilating or decaying to $b\bar{b}$ and ${W^+}{W^-}$ final
states. We then employ a semi-analytic model of interstellar and heliospheric
propagation to calculate the \antihe flux as well as to provide tools to relate
the anti-helium spectrum corresponding to an arbitrary antideuteron spectrum.
Finally, we discuss prospects for current and future experiments, including
GAPS and AMS-02.


title: Acceleration feature points of unsteady shear flows

abstract:
  In this paper, we propose a novel framework to extract features such as
vortex cores and saddle points in two-dimensional unsteady flows. This feature
extraction strategy generalizes critical points of snapshot topology in a
Galilean-invariant manner, allows to prioritize features according to their
strength and longevity, enables to track the temporal evolution of features, is
robust against noise and has no subjective parameters. These characteristics
are realized via several constitutive elements. First, acceleration is employed
as a feature identifier following Goto and Vassilicos (2006), thus ensuring
Galilean invariance. Second, the acceleration magnitude is used as basis for a
mathematically well-developed scalar field topology. The minima of this field
are called acceleration feature points, a superset of the acceleration zeros.
These points are discriminated into vortices and saddle points depending the
spectral properties of the velocity Jacobian. Third, all operations are based
on discrete topology for the scalar field with combinatorial algorithms. This
parameter-free foundation allows (1) to use persistence as a physically
meaningful importance measure to prioritize feature points, (2) ensures
robustness since no differentiation and interpolation need to be performed with
the data, and (3) enables a natural and robust tracking algorithm for the
temporal feature evolution. In particular, we can track vortex merging events
in an unsupervised manner. Data based analyses are presented for an
incompressible periodic cylinder wake, an incompressible planar mixing layer
and a weakly compressible planar jet. They demonstrate the power of the
tracking approach, which provides a spatiotemporal hierarchy of the minima.


title:
Microlens Masses From Astrometry and Parallax in Space-Based Surveys:
  From Planets to Black Holes

abstract:
  We show that space-based microlensing experiments can recover lens masses and
distances for a large fraction of all events (those with individual photometric
errors <~ 0.01 mag) using a combination of one-dimensional microlens parallaxes
and astrometric microlensing. This will provide a powerful probe of the mass
distributions of planets, black holes, and neutron stars, the distribution of
planets as a function of Galactic environment, and the velocity distributions
of black holes and neutron stars. While systematics are in principle a
significant concern, we show that it is possible to vet against all systematics
(known and unknown) using single-epoch precursor observations with the Hubble
Space Telescope roughly 10 years before the space mission.


title:
Estimation of the TeV gamma-ray duty cycle of Mrk 421 with the Milagro
  observatory

abstract:
  Markarian 421 (Mrk 421) is one the brightest and closest (z=0.031) blazars
known (de Vaucouleurs et al 1991). It is also one of the fastest varying TeV
$\gamma$-ray sources, with a flaring activity on time scales as short as tens
of minutes. The activity of Mrk 421 at different frequencies may reflect the
radiation mechanisms involved. Tluczykont et al. (2007) estimated the TeV
activity of Mrk 421 through calculating the fraction of time spent in flaring
states at TeV energies (TeV duty cycle) by using data from several imaging
atmospheric Cherenkov telescopes (IACTs). Since IACT observations are biased
towards high flux states they overestimated the TeV duty cycle of Mrk 421. Here
we propose an alternative approach to calculate the TeV duty cycle of Mrk 421
that takes advantage of the continuous monitoring of the source by the Milagro
experiment, a water Cherenkov detector sensitive to primary $\gamma$-rays
between 100 GeV and 100 TeV. We present our estimation of the TeV - duty cycle
and study its robustness.


title:
Effective Particle Methods for Fisher-Kolmogorov Equations: Theory and
  Applications to Brain Tumor Dynamics

abstract:
  Extended systems governed by partial differential equations can, under
suitable conditions, be approximated by means of sets of ordinary differential
equations for global quantities capturing the essential features of the systems
dynamics. Here we obtain a small number of effective equations describing the
dynamics of single-front and localized solutions of Fisher-Kolmogorov type
equations. These solutions are parametrized by means of a minimal set of
time-dependent quantities for which ordinary differential equations ruling
their dynamics are found. A comparison of the finite dimensional equations and
the dynamics of the full partial differential equation is made showing a very
good quantitative agreement with the dynamics of the partial differential
equation. We also discuss some implications of our findings for the
understanding of the growth progression of certain types of primary brain
tumors and discuss possible extensions of our results to related equations
arising in different modelling scenarios.


title:
Quantifying the effects of local many-qubit errors and non-local
  two-qubit errors on the surface code

abstract:
  Topological quantum error correction codes are known to be able to tolerate
arbitrary local errors given sufficient qubits. This includes correlated errors
involving many local qubits. In this work, we quantify this level of tolerance,
numerically studying the effects of many-qubit errors on the performance of the
surface code. We find that if increasingly large area errors are at least
moderately exponentially suppressed, arbitrarily reliable quantum computation
can still be achieved with practical overhead. We furthermore quantify the
effect of non-local two-qubit correlated errors, which would be expected in
arrays of qubits coupled by a polynomially decaying interaction, and when using
many-qubit coupling devices. We surprisingly find that the surface code is very
robust to this class of errors, despite a provable lack of a threshold error
rate when such errors are present.


title: Soergel bimodules for universal Coxeter groups

abstract:
  We produce an explicit recursive formula which computes the idempotent
projecting to any indecomposable Soergel bimodule for a universal Coxeter
system. This gives the exact set of primes for which the positive
characteristic analogue of Soergel's conjecture holds. Along the way, we
introduce the multicolored Temperley-Lieb algebra.
  An appendix by Ben Webster gives a precise condition on the base ring for a
Jones-Wenzl projector to exist.


title: N2Sky - Neural Networks as Services in the Clouds

abstract:
  We present the N2Sky system, which provides a framework for the exchange of
neural network specific knowledge, as neural network paradigms and objects, by
a virtual organization environment. It follows the sky computing paradigm
delivering ample resources by the usage of federated Clouds. N2Sky is a novel
Cloud-based neural network simulation environment, which follows a pure service
oriented approach. The system implements a transparent environment aiming to
enable both novice and experienced users to do neural network research easily
and comfortably. N2Sky is built using the RAVO reference architecture of
virtual organizations which allows itself naturally integrating into the Cloud
service stack (SaaS, PaaS, and IaaS) of service oriented architectures.


title:
Frequency adjustment and synchrony in networks of delayed pulse coupled
  oscillators

abstract:
  We introduce a system of pulse coupled oscillators that can change both their
phases and frequencies; and prove that when there is a separation of time
scales between phase and frequency adjustment the system converges to exact
synchrony on strongly connected graphs with time delays. The analysis involves
decomposing the network into a forest of tree-like structures that capture
causality. Furthermore, we provide a lower bound for the size of the basin of
attraction with immediate implications for empirical networks and random graph
models. These results provide a robust method of sensor net synchronization as
well as demonstrate a new avenue of possible pulse coupled oscillator research.


title:
Herschel observations of Extra-Ordinary Sources: H2S as a Probe of Dense
  Gas and Possibly Hidden Luminosity Toward the Orion KL Hot Core

abstract:
  We present Herschel/HIFI observations of the light hydride H$_{2}$S obtained
from the full spectral scan of the Orion Kleinmann-Low nebula (Orion KL) taken
as part of the HEXOS GT key program. In total, we observe 52, 24, and 8
unblended or slightly blended features from H$_{2}$$^{32}$S, H$_{2}$$^{34}$S,
and H$_{2}$$^{33}$S, respectively. We only analyze emission from the so called
hot core, but emission from the plateau, extended ridge, and/or compact ridge
are also detected. Rotation diagrams for ortho and para H$_{2}$S follow
straight lines given the uncertainties and yield T$_{\rm rot}$=141$\pm$12 K.
This indicates H$_{2}$S is in LTE and is well characterized by a single kinetic
temperature or an intense far-IR radiation field is redistributing the
population to produce the observed trend. We argue the latter scenario is more
probable and find that the most highly excited states (E$_{\rm up}$>1000 K) are
likely populated primarily by radiation pumping. We derive an H$_{2}$$^{32}$S
column density, N$_{\rm tot}$(H$_{2}$$^{32}$S)=9.5$\pm$1.9$\times$10$^{17}$
cm$^{-2}$, gas kinetic temperature, T$_{\rm kin}$=120$\pm^{13}_{10}$ K, and
constrain the H$_{2}$ volume density, n$_{H2}$>9$\times$10$^{7}$ cm$^{-3}$, for
the H$_{2}$S emitting gas. These results point to an H$_{2}$S origin in
markedly dense, heavily embedded gas, possibly in close proximity to a hidden
self-luminous source (or sources), which are conceivably responsible for Orion
KL's high luminosity. We also derive an H$_{2}$S ortho/para ratio of
1.7$\pm$0.8 and set an upper limit for HDS/H2S of <4.9$\times$10$^{-3}$.


title: Equations in nilpotent groups

abstract:
  We show that there exists an algorithm to decide any single equation in the
Heisenberg group in finite time. The method works for all two-step nilpotent
groups with rank-one commutator, which includes the higher Heisenberg groups.
We also prove that the decision problem for systems of equations is unsolvable
in all non-abelian free nilpotent groups.


title: Combined calculi for photon orbital and spin angular momenta

abstract:
  Context. Wavelength, photon spin angular momentum (PSAM), and photon orbital
angular momentum (POAM), completely describe the state of a photon or an
electric field (an ensemble of photons). Wavelength relates directly to energy
and linear momentum, the corresponding kinetic quantities. PSAMand POAM,
themselves kinetic quantities, are colloquially known as polarization and
optical vortices, respectively. Astrophysical sources emit photons that carry
this information. Aims. PSAM characteristics of an electric field (intensity)
are compactly described by the Jones (Stokes/Mueller) calculus. Similarly, I
created calculi to represent POAM characteristics of electric fields and
intensities in an astrophysical context. Adding wavelength dependence to all of
these calculi is trivial. The next logical steps are to 1) form photon total
angular momentum (PTAM = POAM + PSAM) calculi; 2) prove their validity using
operators and expectation values; and 3) show that instrumental PSAM can affect
measured POAM values for certain types electric fields. Methods. I derive the
PTAM calculi of electric fields and intensities by combining the POAM and PSAM
calculi. I show how these quantities propagate from celestial sphere to image
plane. I also form the PTAMoperator (the sum of the POAMand PSAMoperators),
with and without instrumental PSAM, and calculate the corresponding expectation
values. Results. Apart from the vector, matrix, dot product, and direct product
symbols, the PTAM and POAM calculi appear superficially identical. I provide
tables with all possible forms of PTAM calculi. I prove that PTAM expectation
values are correct for instruments with and without instrumental PSAM. I also
show that POAM measurements of "unfactored" PTAM electric fields passing
through non-zero instrumental circular PSAM can be biased. Conclusions. The
combined PTAM calculi provide insight into how to mathematically model PTAM
sources and calibrate POAMand PSAM- induced POAM measurement errors.


title: Star Cluster Formation and Feedback

abstract:
  Stars do not generally form in isolation. Instead, they form in clusters, and
in these clustered environments newborn stars can have profound effects on one
another and on their parent gas clouds. Feedback from clustered stars is almost
certainly responsible for a number of otherwise puzzling facts about star
formation: that it is an inefficient process that proceeds slowly when averaged
over galactic scales; that most stars disperse from their birth sites and
dissolve into the galactic field over timescales $\ll 1$ Gyr; and that newborn
stars follow an initial mass function (IMF) with a distinct peak in the range
$0.1 - 1$ $M_\odot$, rather than an IMF dominated by brown dwarfs. In this
review we summarize current observational constraints and theoretical models
for the complex interplay between clustered star formation and feedback.


title: Transformation-based Feature Computation for Algorithm Portfolios

abstract:
  Instance-specific algorithm configuration and algorithm portfolios have been
shown to offer significant improvements over single algorithm approaches in a
variety of application domains. In the SAT and CSP domains algorithm portfolios
have consistently dominated the main competitions in these fields for the past
five years. For a portfolio approach to be effective there are two crucial
conditions that must be met. First, there needs to be a collection of
complementary solvers with which to make a portfolio. Second, there must be a
collection of problem features that can accurately identify structural
differences between instances. This paper focuses on the latter issue: feature
representation, because, unlike SAT, not every problem has well-studied
features. We employ the well-known SATzilla feature set, but compute
alternative sets on different SAT encodings of CSPs. We show that regardless of
what encoding is used to convert the instances, adequate structural information
is maintained to differentiate between problem instances, and that this can be
exploited to make an effective portfolio-based CSP solver.


title: p_Hahn Sequence Space

abstract:
  The main purpose of the present paper is to introduce the space h_p and study
of some properties of new sequence space. And we compute their dual spaces and
characterizations of some matrix transformaitons.


title:
The Asymptotic Dirichlet Problems on manifolds with unbounded negative
  curvature

abstract:
  Elton P. Hsu used probabilistic method to show that the asymptotic Dirichlet
problem is uniquely solvable under the curvature conditions $-C e^{2-\eta}r(x)
\leq K_M(x)\leq -1$ with $\eta>0$. We give an analytical proof of the same
statement. In addition, using this new approach we are able to establish two
boundary Harnack inequalities under the curvature condition $-C
e^{(2/3-\eta)r(x)} \leq K_M(x)\leq -1$ with $\eta>0$. This implies that there
is a natural homeomorphism between the Martin boundary and the geometric
boundary of $M$. As far as we know, this is the first result of this kind under
unbounded curvature conditions. Our proofs are modifications of arguments due
to M. T. Anderson and R. Schoen.


title: Photoassociation of long-range $nD$ Rydberg molecules

abstract:
  We observe long-range homonuclear diatomic $nD$ Rydberg molecules
photoassociated out of an ultracold gas of $^{87}$Rb atoms for 34$\le n \le$40.
The measured ground-state binding energies of $^{87}$Rb$(nD-5S_{1/2})$
molecular states are larger than those of their $^{87}$Rb$(nS-5S_{1/2})$
counterparts, showing the dependence of the molecular bond on the angular
momentum of the Rydberg atom. We exhibit the transition of
$^{87}$Rb$(nD-5S_{1/2})$ molecules from a molecular-binding-dominant regime at
low $n$ to a fine-structure-dominant regime at high $n$ [akin to Hund's cases
(a) and (c), respectively]. In the analysis the fine structure of the $nD$
Rydberg atom and the hyperfine structure of the $5S_{1/2}$ atom are included.


title: The minimum $b_2$ problem for right-angled Artin groups

abstract:
  This paper focuses on tools for constructing 4-manifolds that have
fundamental group $G$ isomorphic to a right-angled Artin group and that are
also minimal, in the sense that they minimize $b_2(M)$, the dimension of
$H_2(M;\mathbb{Q})$. For a finitely presented group $G$, define $h(G) = \min\{
b_2(M) | M \in \mathcal M(G) \}$.
  In this paper, we explore the ways in which we can bound $h(G)$ from below
using group cohomology and the tools necessary to build 4-manifolds that
realize these lower bounds. We give solutions for right-angled Artin groups, or
RAAGs, when the graph associated to $G$ has no 4-cliques, and further we reduce
this problem to the case when the graph is connected and contains only
4-cliques. We then give solutions for many infinite families of RAAGs and
provide a conjecture to the solution for all RAAGs.


title:
The $Tb$-theorem on non-homogeneous spaces that proves a conjecture of
  Vitushkin

abstract:
  This article was written in 1999, and was posted as a preprint in CRM
(Barcelona) preprint series $n^0\, 519$ in 2000. However, recently CRM erased
all preprints dated before 2006 from its site, and this paper became
inacessible. It has certain importance though, as the reader shall see.
  Formally this paper is a proof of the (qualitative version of the) Vitushkin
conjecture. The last section is concerned with the quantitative version. This
quantitative version turns out to be very important. It allowed Xavier Tolsa to
close the subject concerning Vtushkin's conjectures: namely, using the
quantitative nonhomogeneous $Tb$ theorem proved in the present paper, he proved
the semiadditivity of analytic capacity. Another "theorem", which is implicitly
contained in this paper, is the statement that any non-vanishing $L^2$-function
is accretive in the sense that if one has a finite measure $\mu$ on the complex
plane ${\mathbb C}$ that is Ahlfors at almost every point (i.e. for
$\mu$-almost every $x\in {\mathbb C}$ there exists a constant $M>0$ such that
$\mu(B(x,r))\le Mr$ for every $r>0$) then any one-dimensional antisymmetric
Calder\'on-Zygmund operator $K$ (e.g. a Cauchy integral type operator)
satisfies the following "all-or-nothing" princple: if there exists at least one
function $\phi\in L^2(\mu)$ such that $\phi(x)\ne 0$ for $\mu$-almost every
$x\in {\mathbb C}$ and such that {\it the maximal singular operator}
$K^*\phi\in L^2(\mu)$, then there exists an everywhere positive weight $w(x)$,
such that $K$ acts from $L^2(\mu)$ to $L^2(wd\mu)$.


title: Lasso Regression: Estimation and Shrinkage via Limit of Gibbs Sampling

abstract:
  The application of the lasso is espoused in high-dimensional settings where
only a small number of the regression coefficients are believed to be nonzero.
Moreover, statistical properties of high-dimensional lasso estimators are often
proved under the assumption that the correlation between the predictors is
bounded. In this vein, coordinatewise methods, the most common means of
computing the lasso solution, work well in the presence of low to moderate
multicollinearity. The computational speed of coordinatewise algorithms
degrades however as sparsity decreases and multicollinearity increases.
Motivated by these limitations, we propose the novel "Deterministic Bayesian
Lasso" algorithm for computing the lasso solution. This algorithm is developed
by considering a limiting version of the Bayesian lasso. The performance of the
Deterministic Bayesian Lasso improves as sparsity decreases and
multicollinearity increases, and can offer substantial increases in
computational speed. A rigorous theoretical analysis demonstrates that (1) the
Deterministic Bayesian Lasso algorithm converges to the lasso solution, and (2)
it leads to a representation of the lasso estimator which shows how it achieves
both $\ell_1$ and $\ell_2$ types of shrinkage simultaneously. Connections to
other algorithms are also provided. The benefits of the Deterministic Bayesian
Lasso algorithm are then illustrated on simulated and real data.


title: Photon and dilepton production in high energy heavy ion collisions

abstract:
  The recent results on direct photons and dileptons in high energy heavy ion
collisions, obtained particularly at RHIC and LHC are reviewed. The results are
new not only in terms of the probes, but also in terms of the precision. We
will discuss the physics learned from the results.


title: STIMONT: A core ontology for multimedia stimuli description

abstract:
  Affective multimedia documents such as images, sounds or videos elicit
emotional responses in exposed human subjects. These stimuli are stored in
affective multimedia databases and successfully used for a wide variety of
research in psychology and neuroscience in areas related to attention and
emotion processing. Although important all affective multimedia databases have
numerous deficiencies which impair their applicability. These problems, which
are brought forward in the paper, result in low recall and precision of
multimedia stimuli retrieval which makes creating emotion elicitation
procedures difficult and labor-intensive. To address these issues a new core
ontology STIMONT is introduced. The STIMONT is written in OWL-DL formalism and
extends W3C EmotionML format with an expressive and formal representation of
affective concepts, high-level semantics, stimuli document metadata and the
elicited physiology. The advantages of ontology in description of affective
multimedia stimuli are demonstrated in a document retrieval experiment and
compared against contemporary keyword-based querying methods. Also, a software
tool Intelligent Stimulus Generator for retrieval of affective multimedia and
construction of stimuli sequences is presented.


title:
Dempster-Shafer Theory for Move Prediction in Start Kicking of The
  Bicycle Kick of Sepak Takraw Game

abstract:
  This paper presents Dempster-Shafer theory for move prediction in start
kicking of the bicycle kick of sepak takraw game. Sepak takraw is a highly
complex net-barrier kicking sport that involves dazzling displays of quick
reflexes, acrobatic twists, turns and swerves of the agile human body movement.
A Bicycle kick or Scissor kick is a physical move made by throwing the body up
into the air, making a shearing movement with the legs to get one leg in front
of the other without holding on to the ground. Specifically, this paper
considers bicycle kick of sepak takraw game in start kicking of the ball with
uncertainty where player has different awareness regarding the contingencies.
We have chosen Dempster-Shafer theory because the advantages of the
Dempster-Shafer theory which include the ability to model information in a
flexible way without requiring a probability to be assigned to each element in
a set, providing a convenient and simple mechanism for combining two or more
pieces of evidence under certain conditions, it can model ignorance explicitly,
rejection of the law of additivity for belief in disjoint propositions.


title:
Experimental determination of radiated internal wave power without
  pressure field data

abstract:
  We present a method to determine, using only velocity field data, the
time-averaged energy flux $\left<\boldsymbol{J}\right>$ and total radiated
power $P$ for two-dimensional internal gravity waves. Both
$\left<\boldsymbol{J}\right>$ and $P$ are determined from expressions involving
only a scalar function, the stream function $\psi$. We test the method using
data from a direct numerical simulation for tidal flow of a stratified fluid
past a knife edge. The results for the radiated internal wave power given by
the stream function method agree to within 0.5% with results obtained using
pressure and velocity data from the numerical simulation. The results for the
radiated power computed from the stream function agree well with power computed
from the velocity and pressure if the starting point for the stream function
computation is on a solid boundary, but if a boundary point is not available,
care must be taken to choose an appropriate starting point. We also test the
stream function method by applying it to laboratory data for tidal flow past a
knife edge, and the results are found to agree with the direct numerical
simulation. Supplementary Material includes a Matlab code with a graphical user
interface (GUI) that can be used to compute the energy flux and power from any
two-dimensional velocity field data.


title:
$C^*$-algebras from planar algebras I: canonical $C^*$-algebras
  associated to a planar algebra

abstract:
  From a planar algebra, we give a functorial construction to produce numerous
associated $C^*$-algebras. Our main construction is a Hilbert $C^*$-bimodule
with a canonical real subspace which produces Pimsner-Toeplitz, Cuntz-Pimsner,
and generalized free semicircular $C^*$-algebras. By compressing this system,
we obtain various canonical $C^*$-algebras, including Doplicher-Roberts
algebras, Guionnet-Jones-Shlyakhtenko algebras, universal
(Toeplitz-)Cuntz-Krieger algebras, and the newly introduced free graph
algebras. This is the first article in a series studying canonical
$C^*$-algebras associated to a planar algebra.


title:
$C^*$-algebras from planar algebras II: the Guionnet-Jones-Shlyakhtenko
  $C^*$-algebras

abstract:
  We study the $C^*$-algebras arising in the construction of
Guionnet-Jones-Shlyakhtenko (GJS) for a planar algebra. In particular, we show
they are pairwise strongly Morita equivalent, we compute their $K$-groups, and
we prove many properties, such as simplicity, unique trace, and stable rank 1.
Interestingly, we see a $K$-theoretic obstruction to the GJS $C^*$-algebra
analog of Goldman-type theorems for II$_1$-subfactors. This is the second
article in a series studying canonical $C^*$-algebras associated to a planar
algebra.


title:
Quantization of a Complex Higher Order Derivative Theory using Path
  Integrals

abstract:
  This work addresses the quantization of a self-interacting higher order time
derivative theory using path integrals. To quantize this system and avoid the
problems of energy not bounded from below and states of negative norm, we
observe the following steps: 1) We extend the theory to the complex plane and
in this sense we double the degrees of freedom. 2) We add a total derivative to
fix the convenient boundary conditions. 3) We check that the complex structure
is consistent. 4) To map from the complex space to the real space we introduce
reality conditions as second class constraints and we check that the
interactions do not generate more constraints. 5) We built the measure of the
complex path integral and we show that including currents the theory is
projected to a self-interacting real theory that is renormalizable.


title: Dark Energy from Quantum Uncertainty of Distant Clock

abstract:
  The observed cosmic acceleration was attributed to an exotic dark energy in
the framework of classical general relativity. The dark energy behaves very
similar with vacuum energy in quantum mechanics. However, once the quantum
effects are seriously taken into account, it predicts a completely wrong result
and leads to a severe fine-tuning. To solve the problem, the exact meaning of
time in quantum mechanics is reexamined. We abandon the standard interpretation
of time in quantum mechanics that time is just a global parameter, replace it
by a quantum dynamical variable playing the role of physical clock. We find
that synchronization of two spatially separated clocks can not be precisely
realized at quantum level. There is an intrinsic quantum uncertainty of distant
clock time, which implies an apparent vacuum energy fluctuation and gives an
observed dark energy density $\rho_{de}=\frac{6}{\pi}L_{P}^{-2}L_{H}^{-2}$ at
tree level approximation, where $L_{P}$ and $L_{H}$ are the Planck and Hubble
scale cutoffs. The fraction of the dark energy is given by
$\Omega_{de}=\frac{2}{\pi}$, which does not evolve with the internal clock
time. The "dark energy" as a quantum cosmic variance is always seen comparable
with the matter energy density by an observer using the internal clock time.
The corrected distance-redshift relation of cosmic observations due to the
distant clock effect are also discussed, which again gives a redshift
independent fraction $\Omega_{de}=\frac{2}{\pi}$. The theory is consistent with
current cosmic observations.


title:
Estimation of Medium Access Control Layer Packet Delay Distribution for
  IEEE 802.11

abstract:
  The most important standard in wireless local area networks is IEEE 802.11.
This is why much of the research work for the enhancement of wireless network
is usually based on the behavior of IEEE 802.11 protocol. However, some of the
ways in which IEEE 802.11 medium access control layer behaves is still
unreliable to guarantee quality of service. For instance, medium access control
layer packet delay, jitter and packet loss rate still remain a challenge. The
main objective of this research is to propose an accurate estimation of the
medium access control layer packet delay distribution for IEEE 802.11. This
estimation considers the differences between busy probability and collision
probability. These differences are employed to achieve a more accurate
estimation. Finally, the proposed model and simulation are implemented and
validated - using MATLAB program for the purpose of simulation, and Maple
program to undertake the calculation of the equations.


title:
An Online Expectation-Maximisation Algorithm for Nonnegative Matrix
  Factorisation Models

abstract:
  In this paper we formulate the nonnegative matrix factorisation (NMF) problem
as a maximum likelihood estimation problem for hidden Markov models and propose
online expectation-maximisation (EM) algorithms to estimate the NMF and the
other unknown static parameters. We also propose a sequential Monte Carlo
approximation of our online EM algorithm. We show the performance of the
proposed method with two numerical examples.


abstract:
  The Interface Region Imaging Spectrograph (IRIS) small explorer spacecraft
provides simultaneous spectra and images of the photosphere, chromosphere,
transition region, and corona with 0.33-0.4 arcsec spatial resolution, 2 s
temporal resolution and 1 km/s velocity resolution over a field-of-view of up
to 175 arcsec x 175 arcsec. IRIS was launched into a Sun-synchronous orbit on
27 June 2013 using a Pegasus-XL rocket and consists of a 19-cm UV telescope
that feeds a slit-based dual-bandpass imaging spectrograph. IRIS obtains
spectra in passbands from 1332-1358, 1389-1407 and 2783-2834 Angstrom including
bright spectral lines formed in the chromosphere (Mg II h 2803 Angstrom and Mg
II k 2796 Angstrom) and transition region (C II 1334/1335 Angstrom and Si IV
1394/1403 Angstrom). Slit-jaw images in four different passbands (C II 1330, Si
IV 1400, Mg II k 2796 and Mg II wing 2830 Angstrom) can be taken simultaneously
with spectral rasters that sample regions up to 130 arcsec x 175 arcsec at a
variety of spatial samplings (from 0.33 arcsec and up). IRIS is sensitive to
emission from plasma at temperatures between 5000 K and 10 MK and will advance
our understanding of the flow of mass and energy through an interface region,
formed by the chromosphere and transition region, between the photosphere and
corona. This highly structured and dynamic region not only acts as the conduit
of all mass and energy feeding into the corona and solar wind, it also requires
an order of magnitude more energy to heat than the corona and solar wind
combined. The IRIS investigation includes a strong numerical modeling component
based on advanced radiative-MHD codes to facilitate interpretation of
observations of this complex region. Approximately eight Gbytes of data (after
compression) are acquired by IRIS each day and made available for unrestricted
use within a few days of the observation.


title: Spectroscopic Study of Extended Star Clusters in Dwarf Galaxy NGC 6822

abstract:
  We present a spectroscopic study of the four extended star clusters (ESCs) in
NGC 6822 based on the data obtained with Gemini Multi-Object Spectrograph
(GMOS) on the Gemini-South 8.1m telescope. Their radial velocities derived from
the spectra range from $-61.2 \pm 20.4$ km s$^{-1}$ (for C1) to $-115.34 \pm
57.9$ km s$^{-1}$ (for C4) and, unlike the intermediate age carbon stars, they
do not display any sign of systematic rotation around NGC 6822. The ages and
metallicities derived using the Lick indices show that the ESCs are old ($\geq
8$ Gyr) and metal poor ([Fe/H]$\lesssim -1.5$). NGC 6822 is found to have both
metal poor ([Fe/H]$\approx -2.0$) and metal rich ([Fe/H]$\approx -0.9$) star
clusters within 15 arcmin (2 kpc) from the center, while only metal poor
clusters are observed in the outer halo with $r \geq 20$ arcmin (2.6 kpc). The
kinematics, old ages, and low metallicities of ESCs suggest that ESCs may have
accreted into the halo of NGC 6822. Based on the velocity distribution of ESCs,
we have determined the total mass and the mass-to-light ratio of NGC 6822:
$M_{N6822} = 7.5^{+4.5}_{-0.1} \times 10^{9} M_{\odot}$ and $(M/L)_{N6822} =
75^{+45}_{-1} (M/L)_{\odot}$. It shows that NGC 6822 is one of the most dark
matter dominated dwarf galaxies in the Local Group.


title: Guessing games

abstract:
  In a guessing game, players guess the value of a random real number selected
using some probability density function. The winner may be determined in
various ways; for example, a winner can be a player whose guess is closest in
magnitude to the target or a winner can be a player coming closest without
guessing higher than the target. We study optimal strategies for players in
these games and determine some of them for two, three, and four players.


title:
Electronic transport calculations for lightly-doped thermoelectrics
  using density functional theory: Application to high-performing Cu-doped zinc
  antimonides

abstract:
  We propose a new method for accurately calculating electrical transport
properties of a lightly-doped thermoelectric material from density functional
theory (DFT) calculations, based on experimental data and density functional
theory results for the corresponding undoped material. We employ this approach
because hybrid DFT calculations are prohibitive for the large supercells
required to model low dopant concentrations comparable to those achieved
experimentally for high-performing thermoelectrics. Using zinc antimonide as
our base material, we find that the electrical transport properties calculated
with DFT and Boltzmann transport theory exhibit the same trends with changes in
chemical potential as those computed with hybrid DFT, and propose a fitting
algorithm that involves adjusting the computed Fermi energy so that the
resulting Seebeck coefficient trends with temperature match experimental
trends. We confirm the validity of this approach in reproducing the
experimental trends in electrical conductivity and Seebeck coefficient versus
temperature for Bi-doped $\beta-$Zn$_4$Sb$_3$. We then screen various
transition metal cation dopants, including copper and nickel, and find that a
Cu dopant concentration of 2.56% in Zn$_{39}$Sb$_{30}$ exhibited a 14% increase
in the thermoelectric power factor for temperatures between 300-400 K. We thus
propose that transition metal dopants may significantly improve the
thermoelectric performance of the host material, compared to heavy and/or
rare-earth dopants.


title:
Operator Preparation and Characteristic Analysis of Open Quantum Systems
  Based on the Lyapunov Control Method

abstract:
  The control laws based on quantum Lyapunov control method are designed to
prepare operators for two level open quantum systems in this paper. A novel
Lyapunov function is proposed according to a matrix logarithm function. The
higher accuracy and faster convergence of the novel Lyapunov function proposed
are analyzed by comparing with the operator distance . We adopt three control
fields, and design two types of control law forms. The first form is to use one
control law to offset the influence of the dissipation, while the other one is
to use all three control laws to offset the dissipation. Moreover, the
robustness of the system Hamiltonian with uncertainty is further investigated
to comprehend the performances of control laws. NOT gates are prepared by the
designed control laws for open quantum systems as well as closed quantum
systems in numerical experiments to verify the superiority of, in which the
performance indexes of distance and fidelity are compared and analyzed.


title:
Reduction of Error-Trellises for Tail-Biting Convolutional Codes Using
  Shifted Error-Subsequences

abstract:
  In this paper, we discuss the reduction of error-trellises for tail-biting
convolutional codes. In the case where some column of a parity-check matrix has
a monomial factor (with indeterminate D), we show that the associated
tail-biting error-trellis can be reduced by cyclically shifting the
corresponding error-subsequence by l (the power of D) time units. We see that
the resulting reduced error-trellis is again tail-biting. Moreover, we show
that reduction is also possible using backward-shifted error-subsequences.


title: Multiscale Shrinkage and L\'evy Processes

abstract:
  A new shrinkage-based construction is developed for a compressible vector
$\boldsymbol{x}\in\mathbb{R}^n$, for cases in which the components of $\xv$ are
naturally associated with a tree structure. Important examples are when $\xv$
corresponds to the coefficients of a wavelet or block-DCT representation of
data. The method we consider in detail, and for which numerical results are
presented, is based on increments of a gamma process. However, we demonstrate
that the general framework is appropriate for many other types of shrinkage
priors, all within the L\'{e}vy process family, with the gamma process a
special case. Bayesian inference is carried out by approximating the posterior
with samples from an MCMC algorithm, as well as by constructing a heuristic
variational approximation to the posterior. We also consider
expectation-maximization (EM) for a MAP (point) solution. State-of-the-art
results are manifested for compressive sensing and denoising applications, the
latter with spiky (non-Gaussian) noise.


title: Quantum Phase Liquids-Fermionic Superfluid without Phase Coherence

abstract:
  We investigate the two dimensional generalized attractive Hubbard model in a
bipartite lattice, and and a "quantum phase liquid" phase, in which the
fermions are paired but don't have phase coherence at zero temperature, in
analogy to quantum spin liquid phase. Then, two types of topological quantum
phase liquids with a small external magnetic field-Z2 quantum phase liquids and
chiral quantum phase liquids-are discussed.


title: On (t,r) Broadcast Domination Numbers of Grids

abstract:
  The domination number of a graph $G = (V,E)$ is the minimum cardinality of
any subset $S \subset V$ such that every vertex in $V$ is in $S$ or adjacent to
an element of $S$. Finding the domination numbers of $m$ by $n$ grids was an
open problem for nearly 30 years and was finally solved in 2011 by Goncalves,
Pinlou, Rao, and Thomass\'e. Many variants of domination number on graphs have
been defined and studied, but exact values have not yet been obtained for
grids. We will define a family of domination theories parameterized by pairs of
positive integers $(t,r)$ where $1 \leq r \leq t$ which generalize domination
and distance domination theories for graphs. We call these domination numbers
the $(t,r)$ broadcast domination numbers. We give the exact values of $(t,r)$
broadcast domination numbers for small grids, and we identify upper bounds for
the $(t,r)$ broadcast domination numbers for large grids and conjecture that
these bounds are tight for sufficiently large grids.


title:
Anomalous transport effects and possible environmental symmetry
  "violation" in heavy ion collisions

abstract:
  The heavy ion collision provides a unique many-body environment where local
domains of strongly interacting chiral medium may occur and in a sense allow
environmental symmetry "violation" phenomena. For example certain anomalous
transport processes, forbidden in usual medium, become possible in such
domains. We briefly review recent progress in both the theoretical
understanding and experimental search of various anomalous transport effects
(such as the Chiral Magnetic Effect, Chiral Separation Effect, Chiral Electric
Separation Effect, Chiral Electric/Magnetic Waves, etc) in the hot QCD fluid
created by such collisions.


title: Algebraic Form of M3-Brane Action

abstract:
  We reformulate the bosonic action of unstable M3-brane to manifest its
algebraic representation. It is seen that in contrast with string and M2-brane
actions that are represented only in terms of two and three dimensional
Lie-algebras respectively, the algebraic form of M3-brane action is a
combination of four, three and two dimensional Lie-algebras. Corresponding
brackets appear as mixtures of tachyon field, space-time coordinates, $X$,
two-form field, $\hat{\omega}^{(2)}$, and Born-Infeld one-form, $\hat{b}_\mu$.


title:
The Unified Transform for the modified Helmholtz equation in the
  exterior of a square

abstract:
  The Unified Transform provides a novel method for analyzing boundary value
problems for linear and for integrable nonlinear PDEs. The numerical
implementation of this method to linear elliptic PDEs formulated in the {\it
interior} of a polygon has been investigated by several authors (see the
article by Iserles, Smitheman, and one of the authors in this book). Here, we
show that the Unified Transform also yields a novel numerical technique for
computing the solution of linear elliptic PDEs in the {\it exterior} of a
polygon. One of the advantages of this new technique is that it actually yields
directly the scattering amplitude. Details are presented for the modified
Helmholtz equation in the exterior of a square.


title:
Does Restraining End Effect Matter in EMD-Based Modeling Framework for
  Time Series Prediction? Some Experimental Evidences

abstract:
  Following the "decomposition-and-ensemble" principle, the empirical mode
decomposition (EMD)-based modeling framework has been widely used as a
promising alternative for nonlinear and nonstationary time series modeling and
prediction. The end effect, which occurs during the sifting process of EMD and
is apt to distort the decomposed sub-series and hurt the modeling process
followed, however, has been ignored in previous studies. Addressing the end
effect issue, this study proposes to incorporate end condition methods into
EMD-based decomposition and ensemble modeling framework for one- and multi-step
ahead time series prediction. Four well-established end condition methods,
Mirror method, Coughlin's method, Slope-based method, and Rato's method, are
selected, and support vector regression (SVR) is employed as the modeling
technique. For the purpose of justification and comparison, well-known NN3
competition data sets are used and four well-established prediction models are
selected as benchmarks. The experimental results demonstrated that significant
improvement can be achieved by the proposed EMD-based SVR models with end
condition methods. The EMD-SBM-SVR model and EMD-Rato-SVR model, in particular,
achieved the best prediction performances in terms of goodness of forecast
measures and equality of accuracy of competing forecasts test.


title:
Multi-Step-Ahead Time Series Prediction using Multiple-Output Support
  Vector Regression

abstract:
  Accurate time series prediction over long future horizons is challenging and
of great interest to both practitioners and academics. As a well-known
intelligent algorithm, the standard formulation of Support Vector Regression
(SVR) could be taken for multi-step-ahead time series prediction, only relying
either on iterated strategy or direct strategy. This study proposes a novel
multiple-step-ahead time series prediction approach which employs
multiple-output support vector regression (M-SVR) with multiple-input
multiple-output (MIMO) prediction strategy. In addition, the rank of three
leading prediction strategies with SVR is comparatively examined, providing
practical implications on the selection of the prediction strategy for
multi-step-ahead forecasting while taking SVR as modeling technique. The
proposed approach is validated with the simulated and real datasets. The
quantitative and comprehensive assessments are performed on the basis of the
prediction accuracy and computational cost. The results indicate that: 1) the
M-SVR using MIMO strategy achieves the best accurate forecasts with accredited
computational load, 2) the standard SVR using direct strategy achieves the
second best accurate forecasts, but with the most expensive computational cost,
and 3) the standard SVR using iterated strategy is the worst in terms of
prediction accuracy, but with the least computational cost.


title:
On integral forms for vertex algebras associated with affine Lie
  algebras and lattices

abstract:
  We revisit the construction of integral forms for vertex (operator) algebras
$V_L$ based on even lattices $L$ using generators instead of bases, and we
construct integral forms for $V_L$-modules. We construct integral forms for
vertex (operator) algebras based on highest-weight modules for affine Lie
algebras and we exhibit natural generating sets. For vertex operator algebras
in general, we give conditions showing when an integral form contains the
standard conformal vector generating the Virasoro algebra. Finally, we study
integral forms in contragredients of modules for vertex algebras.


title: Matrix Riemann-Hilbert problems with jumps across Carleson contours

abstract:
  We develop a theory of $n \times n$-matrix Riemann-Hilbert problems for a
class of jump contours and jump matrices of low regularity. Our basic
assumption is that the contour $\Gamma$ is a finite union of simple closed
Carleson curves in the Riemann sphere. In particular, contours with cusps,
corners, and nontransversal intersections are allowed. We introduce a notion of
$L^p$-Riemann-Hilbert problem and establish basic uniqueness results and a
vanishing lemma. We also investigate the implications of Fredholmness for the
unique solvability and prove a theorem on contour deformation.


title:
Characteristic-Dependent Linear Rank Inequalities with Applications to
  Network Coding

abstract:
  Two characteristic-dependent linear rank inequalities are given for eight
variables. Specifically, the first inequality holds for all finite fields whose
characteristic is not three and does not in general hold over characteristic
three. The second inequality holds for all finite fields whose characteristic
is three and does not in general hold over characteristics other than three.
Applications of these inequalities to the computation of capacity upper bounds
in network coding are demonstrated.


title:
Perturbative and exact results on the Neumann value for the nonlinear
  Schr\"odinger equation on the half-line

abstract:
  The most challenging problem in the implementation of the so-called
\textit{unified transform} to the analysis of the nonlinear Schr\"odinger
equation on the half-line is the characterization of the unknown boundary value
in terms of the given initial and boundary conditions. For the so-called
\textit{linearizable} boundary conditions this problem can be solved
explicitly. Furthermore, for non-linearizable boundary conditions which decay
for large $t$, this problem can be largely bypassed in the sense that the
unified transform yields useful asymptotic information for the large $t$
behavior of the solution. However, for the physically important case of
periodic boundary conditions it is necessary to characterize the unknown
boundary value. Here, we first present a perturbative scheme which can be used
to compute explicitly the asymptotic form of the Neumann boundary value in
terms of the given $\tau$-periodic Dirichlet datum to any given order in a
perturbation expansion. We then discuss briefly an extension of the pioneering
results of Boutet de Monvel and co-authors which suggests that if the Dirichlet
datum belongs to a large class of particular $\tau$-periodic functions, which
includes $\{a \exp(i \omega t) \, | \, a>0, \, \omega \geq a^2\}$, then the
large $t$ behavior of the Neumann value is given by a $\tau$-periodic function
which can be computed explicitly.


title:
Results of the four-wave kinetic integral computation for spectra of
  special forms. The case of Zakharov spectra

abstract:
  With the aim to show explicitly the non stationarity of the Zakharov spectra,
obtained analytically as the stationary solution of the four-wave kinetic
equation for stochastic nonlinear surface gravity waves[1,2], we have
calculated directly the proper kinetic integral by means of two independent
algorithms[3,4] both for an isotropic and anisotropic angular distribution of
spectra given on the restricted frequency band.


title:
The attractive Bose gas in two dimensions: an analytical study of its
  fragmentation and collapse

abstract:
  An attractive Bose-Einstein condensate in two spatial dimensions is expected
to collapse for supercritical values of the interaction strength. Moreover, it
is known that for nonzero quanta of angular momentum and infinitesimal
attraction the gas prefers to fragment and distribute its angular momentum over
different orbitals. In this work we examine the two-dimensional Bose gas for
finite values of attraction and describe the ground state in connection to its
angular momentum by theoretical methods that go beyond the standard
Gross-Pitaevskii theory. By applying the best mean field approach, we derive
analytical relations for the energy, the fragmentation of the ground states and
the critical (for collapse) value of the attraction strength as a function of
the total angular momentum $L$.


title:
Mass-Loss Evolution of Close-In Exoplanets: Evaporation of Hot Jupiters
  and the Effect on Population

abstract:
  During their evolution, short-period exoplanets may lose envelope mass
through atmospheric escape owing to intense XUV (X-ray and extreme ultraviolet)
radiation from their host stars. Roche-lobe overflow induced by orbital
evolution or intense atmospheric escape can also contribute to mass loss. To
study the effects of mass loss on inner planet populations, we calculate the
evolution of hot Jupiters considering mass loss of their envelopes and thermal
contraction. Mass loss is assumed to occur through XUV-driven atmospheric
escape and the following Roche-lobe overflow. The runaway effect of mass loss
results in a dichotomy of populations: hot Jupiters that retain their envelopes
and super Earths whose envelopes are completely lost. Evolution primarily
depends on the core masses of planets and only slightly on migration history.
In hot Jupiters with small cores (~10 Earth masses), runaway atmospheric escape
followed by Roche-lobe overflow may create sub-Jupiter deserts, as observed in
both mass and radius distributions of planetary populations. Comparing our
results with formation scenarios and observed exoplanets populations, we
propose that populations of closely orbiting exoplanets are formed by capturing
of planets at/inside the inner edges of protoplanetary disks and subsequent
evaporation of sub-Jupiters.


title:
Observation of hysteretic phase-switching in silicon by piezoresponse
  force microscopy

abstract:
  We report the observation of $180^o$ phase switching on silicon wafers by
piezo-response force microscopy (PFM). The switching is hysteretic and shows
remarkable similarities with polarization switching in ferroelectrics. This is
always accompanied by a hysteretic amplitude vs. voltage curve which resembles
the "butterfly loops" for piezoelectric materials. From a detailed analysis of
the data obtained under different environmental and experimental conditions, we
show that the hysteresis effects in phase and amplitude do not originate from
ferro-electricity or piezoelectricity. This further indicates that mere
observation of hysteresis effects in PFM does not confirm the existence of
ferroelectric and/or piezoelectric ordering in materials. We also show that
when samples are mounted on silicon for PFM measurements, the switching
properties of silicon may appear on the sample even if the sample thickness is
large.


title:
Dynamics of mobile interacting ferromagnetic films: theory and numerical
  implementation

abstract:
  Coating two nearby bodies with thin ferromagnetic films one obtains, below
the Curie temperature, two interacting sets of magnetic domains. The dynamical
properties of the bodies in presence of this domain interaction have never been
investigated so far. In this work I derive a set of equations to simultaneously
describe both the domain evolution within the two films and the dynamics of the
coated bodies. The shape, size and mobility of the domains can be easily
controlled with an external magnetic field or properly choosing the material
properties, thus unravelling how the domain characteristics influence the
system dynamics. This can be thus of great technological relevance, providing
new means to control and actuate mechanical motion at the micro- and
nano-scale.


title:
QoS Constrained Optimal Sink and Relay Placement in Planned Wireless
  Sensor Networks

abstract:
  We are given a set of sensors at given locations, a set of potential
locations for placing base stations (BSs, or sinks), and another set of
potential locations for placing wireless relay nodes. There is a cost for
placing a BS and a cost for placing a relay. The problem we consider is to
select a set of BS locations, a set of relay locations, and an association of
sensor nodes with the selected BS locations, so that number of hops in the path
from each sensor to its BS is bounded by hmax, and among all such feasible
networks, the cost of the selected network is the minimum. The hop count bound
suffices to ensure a certain probability of the data being delivered to the BS
within a given maximum delay under a light traffic model. We observe that the
problem is NP-Hard, and is hard to even approximate within a constant factor.
For this problem, we propose a polynomial time approximation algorithm
(SmartSelect) based on a relay placement algorithm proposed in our earlier
work, along with a modification of the greedy algorithm for weighted set cover.
We have analyzed the worst case approximation guarantee for this algorithm. We
have also proposed a polynomial time heuristic to improve upon the solution
provided by SmartSelect. Our numerical results demonstrate that the algorithms
provide good quality solutions using very little computation time in various
randomly generated network scenarios.


title: An intuitionistic version of Ramsey Theorem (italian version)

abstract:
  Ramsey Theorem [6] for pairs is intuitionistically but not classically
provable: it is equivalent to a subclassical principle [2]. In this note we
show that Ramsey may be restated in an intuitionistically provable form, which
is informative (or at least without negations), and classically equivalent to
the original. With respect to previous works of the same kind, we do not use no
counterexample as in [1], [5], nor we add a new principle to the intuitionism
as in [4]. We claim that this intuitionistic version of Ramsey could be use to
replace Ramsey Theorem in the convergence proof of programs included in [3].
  [1] Gianluigi Bellin. Ramsey interpreted: a parametric version of Ramsey
Theorem. In AMS, editor, Logic and Computation: Proceedings of a Symposium held
at Carnegie Mellon University, volume 106.
  [2] Stefano Berardi, Silvia Steila, Ramsey Theorem for pairs as a classical
principle in Intuitionistic Arithmetic, Submitted to the proceedings of Types
2013 in Toulouse.
  [3] Byron Cook, Abigail See, Florian Zuleger, Ramsey vs. Lexicographic
Termination Proving, LNCS 7795, 2013, Springer Berlin Heidelberg.
  [4] Thierry Coquand. A direct proof of Ramsey Theorem.
  [5] Paulo Oliva and Thomas Powell. A Constructive Interpretation of Ramsey
Theorem via the Product of Selection Functions. CoRR, arXiv:1204.5631, 2012.
  [6] F. P. Ramsey. On a problem in formal logic. Proc. London Math. Soc.,
1930.


title:
Progressive Filtering Using Multiresolution Histograms for Query by
  Humming System

abstract:
  The rising availability of digital music stipulates effective categorization
and retrieval methods. Real world scenarios are characterized by mammoth music
collections through pertinent and non-pertinent songs with reference to the
user input. The primary goal of the research work is to counter balance the
perilous impact of non-relevant songs through Progressive Filtering (PF) for
Query by Humming (QBH) system. PF is a technique of problem solving through
reduced space. This paper presents the concept of PF and its efficient design
based on Multi-Resolution Histograms (MRH) to accomplish searching in
manifolds. Initially the entire music database is searched to obtain high
recall rate and narrowed search space. Later steps accomplish slow search in
the reduced periphery and achieve additional accuracy.
  Experimentation on large music database using recursive programming
substantiates the potential of the method. The outcome of proposed strategy
glimpses that MRH effectively locate the patterns. Distances of MRH at lower
level are the lower bounds of the distances at higher level, which guarantees
evasion of false dismissals during PF. In due course, proposed method helps to
strike a balance between efficiency and effectiveness. The system is scalable
for large music retrieval systems and also data driven for performance
optimization as an added advantage.


title: The semantic similarity ensemble

abstract:
  Computational measures of semantic similarity between geographic terms
provide valuable support across geographic information retrieval, data mining,
and information integration. To date, a wide variety of approaches to
geo-semantic similarity have been devised. A judgment of similarity is not
intrinsically right or wrong, but obtains a certain degree of cognitive
plausibility, depending on how closely it mimics human behavior. Thus selecting
the most appropriate measure for a specific task is a significant challenge. To
address this issue, we make an analogy between computational similarity
measures and soliciting domain expert opinions, which incorporate a subjective
set of beliefs, perceptions, hypotheses, and epistemic biases. Following this
analogy, we define the semantic similarity ensemble (SSE) as a composition of
different similarity measures, acting as a panel of experts having to reach a
decision on the semantic similarity of a set of geographic terms. The approach
is evaluated in comparison to human judgments, and results indicate that an SSE
performs better than the average of its parts. Although the best member tends
to outperform the ensemble, all ensembles outperform the average performance of
each ensemble's member. Hence, in contexts where the best measure is unknown,
the ensemble provides a more cognitively plausible approach.


title:
Optimal Embedding of Functions for In-Network Computation: Complexity
  Analysis and Algorithms

abstract:
  We consider optimal distributed computation of a given function of
distributed data. The input (data) nodes and the sink node that receives the
function form a connected network that is described by an undirected weighted
network graph. The algorithm to compute the given function is described by a
weighted directed acyclic graph and is called the computation graph. An
embedding defines the computation communication sequence that obtains the
function at the sink. Two kinds of optimal embeddings are sought, the embedding
that---(1)~minimizes delay in obtaining function at sink, and (2)~minimizes
cost of one instance of computation of function. This abstraction is motivated
by three applications---in-network computation over sensor networks, operator
placement in distributed databases, and module placement in distributed
computing.
  We first show that obtaining minimum-delay and minimum-cost embeddings are
both NP-complete problems and that cost minimization is actually MAX SNP-hard.
Next, we consider specific forms of the computation graph for which polynomial
time solutions are possible. When the computation graph is a tree, a polynomial
time algorithm to obtain the minimum delay embedding is described. Next, for
the case when the function is described by a layered graph we describe an
algorithm that obtains the minimum cost embedding in polynomial time. This
algorithm can also be used to obtain an approximation for delay minimization.
We then consider bounded treewidth computation graphs and give an algorithm to
obtain the minimum cost embedding in polynomial time.


title: Superdiffusion revisited in view of collisionless reconnection

abstract:
  The concept of diffusion in collisionless space plasmas like those near the
magnetopause and in the geomagnetic tail is reexamined from a fundamental
statistical point of view making use of the division of particle orbits into
waiting orbits and break-out into ballistic motion lying at the bottom, for
instance, of L\'evy flights and the celebrated $\kappa$-distribution. A
stringent derivation yields an anomalous diffusion coefficient increasing with
time, thus describing superdiffusion. Contrary to wide belief, superdiffusion,
though faster than classical, is a weak process. Absolute values of the
coefficient are small due to the largeness of the anomalous collision frequency
in waiting statistics compared with the infinitesimally small binary collision
frequency. We provide parallel and perpendicular diffusion coefficients,
determine the exponents of temporal increase, determine the power and $\kappa$
for two-dimensional diffusion by referring to published numerical
particle-in-cell simulations, fix the range of permitted $\kappa$s, and
construct a relation between the diffusion coefficients and the resistive
scale. We furthermore find an expression for the anomalous collision frequency
from the electron pseudo-viscosity in reconnection thus identifying
reconnection as a localized diffusion process in satisfactory agreement with
basic physical concepts.


title: Hashimoto transform for stochastic Landau-Lifshitz-Gilbert equation

abstract:
  We show that Hashimoto transformation is applicable to the one dimensional
stochastic Landau-Lifshitz-Gilbert (LLG) equation and transforms it to the
stochastic generalized heat equation with nonlocal (in space) interaction.


title: Limits of Random Trees

abstract:
  Local convergence of bounded degree graphs was introduced by Benjamini and
Schramm. This result was extended further by Lyons to bounded average degree
graphs. In this paper, we study the convergence of a random tree sequence where
the probability of a given tree is proportional to $\prod_{v_i\in
V(T)}d(v_i)!$. We show that this sequence is convergent and describe the limit
object, which is a random infinite rooted tree.


title: Weibel, Firehose and Mirror mode Relations

abstract:
  Excitation of Weibel magnetic fields in an initially non-magnetized though
anisotropic plasma may trigger other low-frequency instabilities fed by
pressure anisotropy. It is shown that under Weibel-like-stable conditions the
Weibel-like thermal fluctuation magnetic field allows for restricted
Firehose-mode growth. In addition, low frequency Whistlers can also propagate
in the plasma under certain anisotropic conditions. When the Weibel-like mode
becomes unstable, Firehose instability ceases but Mirror modes take over. This
will cause bubble structures in the Weibel-like field in addition to
filamentation.


title:
Wong-Zakai approximation of solutions to reflecting stochastic
  differential equations on domains in Euclidean spaces II

abstract:
  The strong convergence of Wong-Zakai approximations of the solution to the
reflecting stochastic differential equations was studied in [2]. We continue
the study and prove the strong convergence under weaker assumptions on the
domain.


title:
Four Points Beginner Risk Managers Should Learn from Jeff Holman's
  Mistakes in the Discussion of Antifragile

abstract:
  Using Jeff Holman's comments in Quantitative Finance to illustrate 4 critical
errors students should learn to avoid: 1) Mistaking tails (4th moment) for
volatility (2nd moment), 2) Missing Jensen's Inequality, 3) Analyzing the
hedging wihout the underlying, 4) The necessity of a numeraire in finance.


title: A new representation of the light curve and its power density spectrum

abstract:
  We present a new representation of light curves, which is quite different
from the binning method. Instead of choosing uniform bins, the reciprocal of
interval between two successive photons is adopted to represent the counting
rate. A primary application of this light curve is to compute the power density
spectrum by means of Lomb Periodogram and to find possible periods. To verify
this new representation, we apply this method to artificial periodic data and
some known periodic celestial objects, and the periods are all correctly found.
Compared with the traditional fast Fourier transform method, our method does
not rely on the bin size and has a spontaneously high time resolution,
guaranteeing a wide frequency range in power density spectrum, and is
especially useful when the photons are rare for its little information losses.
Some other applications of the new light curve, like pulse identification,
variability and spectral time lag, are also discussed.


title:
Detection of the nonlocal atomic entanglement assisted with single
  photons

abstract:
  We present an efficient way for measuring the entanglement of the atoms.
Through the auxiliary single photons input-output process in cavity quantum
electrodynamics (QED), the concurrence of the atomic entanglement can be
obtained according to the success probability of picking up the singlet states
of the atoms. This protocol has three advantages: First, we do not require the
sophisticated controlled-not (CNOT) gates. Second, the distributed atoms are
not required to intact with each other. Third, the atomic entanglement can be
distributed nonlocally, which provides its important applications in
distributed quantum computation.


title: Right Sneutrino Dark Matter and a Monochromatic Photon Line

abstract:
  The inclusion of right-chiral sneutrino superfields is a rather
straightforward addition to a supersymmetric scenario. A neutral scalar with a
substantial right sneutrino component is often a favoured dark matter candidate
in such cases. In this context, we focus on the tentative signal in the form of
a monochromatic photon, which may arise from dark matter annihilation and has
drawn some attention in recent times. We study the prospect of such a right
sneutrino dark matter candidate in the contexts of both MSSM and NMSSM extended
with right sneutrino superfields, with special reference to the Fermi-LAT data.


title:
Resonant instability of the nonlinearly-saturated magnetorotational mode
  in thin Keplerian discs

abstract:
  The magneto-rotational decay instability (MRDI) of thin Keplerian discs
threaded by poloidal magnetic fields is introduced and studied. The linear
magnetohydrodynamic problem decouples into eigenvalue problems for in-plane
slow- and fast- Alfv'een-Coriolis (AC), and vertical magnetosonic (MS)
eigenmodes. The magnetorotational instability (MRI) is composed of a discrete
number of unstable slow AC eigenmodes that is determined for each radius by the
local beta. In the vicinity of the first beta threshold a parent MRI eigenmode
together with a stable AC eigenmode (either slow or fast) and a stable MS
eigenmode form a resonant triad. The three-wave MRDI relies on the nonlinear
saturation of the parent MRI mode and the exponential growth of two daughter
linearly stable waves, slow-AC and MS modes with an effective growth rate that
is comparable to that of the parent MRI. If, however, the role of the AC
daughter wave is played by a stable fast mode, all three modes remain bounded.


title: A Study of Image Analysis with Tangent Distance

abstract:
  The computation of the geometric transformation between a reference and a
target image, known as registration or alignment, corresponds to the projection
of the target image onto the transformation manifold of the reference image
(the set of images generated by its geometric transformations). It, however,
often takes a nontrivial form such that the exact computation of projections on
the manifold is difficult. The tangent distance method is an effective
algorithm to solve this problem by exploiting a linear approximation of the
manifold. As theoretical studies about the tangent distance algorithm have been
largely overlooked, we present in this work a detailed performance analysis of
this useful algorithm, which can eventually help its implementation. We
consider a popular image registration setting using a multiscale pyramid of
lowpass filtered versions of the (possibly noisy) reference and target images,
which is particularly useful for recovering large transformations. We first
show that the alignment error has a nonmonotonic variation with the filter
size, due to the opposing effects of filtering on both manifold nonlinearity
and image noise. We then study the convergence of the multiscale tangent
distance method to the optimal solution. We finally examine the performance of
the tangent distance method in image classification applications. Our
theoretical findings are confirmed by experiments on image transformation
models involving translations, rotations and scalings. Our study is the first
detailed study of the tangent distance algorithm that leads to a better
understanding of its efficacy and to the proper selection of its design
parameters.


title: A General Construction of Binary Sequences with Optimal Autocorrelation

abstract:
  A general construction of binary sequences with low autocorrelation are
considered in the paper. Based on recent progresses about this topic and this
construction, several classes of binary sequences with optimal autocorrelation
and other low autocorrelation are presented.


title:
Optimal control of uncertain stochastic systems with Markovian switching
  and its applications to portfolio decisions

abstract:
  This paper first describes a class of uncertain stochastic control systems
with Markovian switching, and derives an It\^o-Liu formula for Markov-modulated
processes. And we characterize an optimal control law, which satisfies the
generalized Hamilton-Jacobi-Bellman (HJB) equation with Markovian switching.
Then, by using the generalized HJB equation, we deduce the optimal consumption
and portfolio policies under uncertain stochastic financial markets with
Markovian switching. Finally, for constant relative risk-aversion (CRRA)
felicity functions, we explicitly obtain the optimal consumption and portfolio
policies. Moreover, we also make an economic analysis through numerical
examples.


title: Parameterized Complexity of Edge Interdiction Problems

abstract:
  We study the parameterized complexity of interdiction problems in graphs. For
an optimization problem on graphs, one can formulate an interdiction problem as
a game consisting of two players, namely, an interdictor and an evader, who
compete on an objective with opposing interests. In edge interdiction problems,
every edge of the input graph has an interdiction cost associated with it and
the interdictor interdicts the graph by modifying the edges in the graph, and
the number of such modifications is constrained by the interdictor's budget.
The evader then solves the given optimization problem on the modified graph.
The action of the interdictor must impede the evader as much as possible. We
focus on edge interdiction problems related to minimum spanning tree, maximum
matching and shortest paths. These problems arise in different real world
scenarios. We derive several fixed-parameter tractability and W[1]-hardness
results for these interdiction problems with respect to various parameters.
Next, we show close relation between interdiction problems and partial cover
problems on bipartite graphs where the goal is not to cover all elements but to
minimize/maximize the number of covered elements with specific number of sets.
Hereby, we investigate the parameterized complexity of several partial cover
problems on bipartite graphs.


title:
Integrable and superintegrable Hamiltonian systems with four dimensional
  real Lie algebras as symmetry of the systems

abstract:
  We construct integrable and superintegrable Hamiltonian systems using the
realizations of four dimensional real Lie algebras as a symmetry of the system
with the phase space R4 and R6. Furthermore, we construct some integrable and
superintegrable Hamiltonian systems for which the symmetry Lie group is also
the phase space of the system.