title:
Multidimensional X-Ray Spectroscopy of Valence and Core Excitations in
  Cysteine

abstract:
  Several nonlinear spectroscopy experiments which employ broadband x-ray
pulses to probe the coupling between localized core and delocalized valence
excitation are simulated for the amino acid cysteine at the K-edges of oxygen
and nitrogen and the K and L-edges of sulfur. We focus on two dimensional (2D)
and 3D signals generated by two- and three-pulse stimulated x-ray Raman
spectroscopy (SXRS) with frequency-dispersed probe. We show how the four-pulse
x-ray signals
$\boldsymbol{k}_\mathrm{I}=-\boldsymbol{k}_1+\boldsymbol{k}_2+\boldsymbol{k}_3$
and
$\boldsymbol{k}_\mathrm{II}=\boldsymbol{k}_1-\boldsymbol{k}_2+\boldsymbol{k}_3$
can give new 3D insight into the SXRS signals. The coupling between valence-
and core-excited states can be visualized in three dimensional plots, revealing
the origin of the polarizability that controls the simpler pump-probe SXRS
signals.

categories: physics.chem-ph physics.acc-ph physics.atom-ph quant-ph


title:
Highly relativistic circular orbits of spinning particle in the Kerr
  field

abstract:
  The Mathisson-Papapetrou equations in Kerr's background are considered. The
region of existence of highly relativistic planar circular orbits of a spinning
particle in this background and dependence of the particle's Lorentz
$\gamma$-factor on its spin and radial coordinate are investigated. It is shown
that in contrast to the highly relativistic circular orbits of a spinless
particle the corresponding orbits of a spinning particle are allowed in much
wider space region. Some of these orbits show the significant attractive action
of the spin-gravity coupling on a particle and others are caused by the
significant repulsive action. Numerical estimates for electrons, protons and
neutrinos in the gravitational field of black holes are presented.


title: Finite-sites corrections to the Casimir energy on a periodic lattice

abstract:
  We show that the vacuum ground state energy for massive scalars on a 1-dim
L-sites periodic lattice can be interpreted as the thermodynamic free energy of
particles at temperature 1/L governed by the Arutyunov-Frolov mirror
Hamiltonian. Although the obligatory zero-point sum-over-frequencies is finite
on the lattice, a renormalization prescription is necessary in order to obtain
a physical sensible result for the lattice Casimir energy. The coefficients of
every term in the large L expansion of the lattice Casimir energy are provided
in terms of modified Bessel functions.


title:
Asymptotics for sums of random variables with local subexponential
  behaviour

abstract:
  We study distributions $F$ on $[0,\infty)$ such that for some $T\le\infty$,
$F^{*2}(x,x+T]\sim 2 F(x,x+T]$. The case $T=\infty$ corresponds to $F$ being
subexponential, and our analysis shows that the properties for $T<\infty$ are,
in fact, very similar to this classical case. A parallel theory is developed in
the presence of densities. Applications are given to random walks, the key
renewal theorem, compound Poisson process and Bellman-Harris branching
processes.


title:
The Structure of Galaxies: II. Fitting Functions and Scaling Relations
  for Ellipticals

abstract:
  Surface photometry of 311 ellipticals from the 2MASS imaging database is
analyzed with respect to the two most common fitting functions; the r^1/4 law
and the Sersic r^1/n model. The advantages and disadvantages of each fitting
function are examined. In particular, the r^1/4 law performs well in the middle
regions, but is inadequate for the core (inner 5 kpcs) and the outer regions
(beyond the half-light radius) which do not have r^1/4 shapes. It is found that
the Sersic r^1/n model produce good fits to the core regions of ellipticals (r
< r_half), but is an inadequate function for the entire profile of an
elliptical from core to halo due to competing effects on the Sersic n index and
the fact that the interior shape of an elliptical is only weakly correlated
with its halo shape. In addition, there are a wide range of Sersic parameters
that will equally describe the shape of the outer profile, degrading the Sersic
models usefulness as a describer of the entire profile. Empirically determined
parameters, such as half-light radius and total luminosity, have less scatter
than fitting function variables. The scaling relations for ellipticals are
often non-linear, but for ellipticals brighter than M_J < -23 the following
structural relations are found: L propto r^0.8 \pm 0.1, L propto Sigma^-0.5 \pm
0.1 and Sigma propto r^-1.5 \pm 0.1.


title:
An Ant-Based Algorithm with Local Optimization for Community Detection
  in Large-Scale Networks

abstract:
  In this paper, we propose a multi-layer ant-based algorithm MABA, which
detects communities from networks by means of locally optimizing modularity
using individual ants. The basic version of MABA, namely SABA, combines a
self-avoiding label propagation technique with a simulated annealing strategy
for ant diffusion in networks. Once the communities are found by SABA, this
method can be reapplied to a higher level network where each obtained community
is regarded as a new vertex. The aforementioned process is repeated
iteratively, and this corresponds to MABA. Thanks to the intrinsic multi-level
nature of our algorithm, it possesses the potential ability to unfold
multi-scale hierarchical structures. Furthermore, MABA has the ability that
mitigates the resolution limit of modularity. The proposed MABA has been
evaluated on both computer-generated benchmarks and widely used real-world
networks, and has been compared with a set of competitive algorithms.
Experimental results demonstrate that MABA is both effective and efficient (in
near linear time with respect to the size of network) for discovering
communities.


title: Engel theorem through singularities

abstract:
  We prove a singular version of the Engel theorem. We prove a normal form
theorem for germs of holomorphic singular Engel systems with good conditions on
its singular set. As an application, we prove that there exists an integral
analytic curve passing through the singular points of the system. Also, we
prove that a globally decomposable Engel system on a four dimensional
projective space has singular set with atypical codimension.


title:
A proposal to implement a quantum delayed choice experiment assisted by
  a cavity QED

abstract:
  We propose a scheme feasible with current technology to implement a quantum
delayed-choice experiment in the realm of cavity QED. Our scheme uses two-level
atoms interacting on and off resonantly with a single mode of a high Q cavity.
At the end of the protocol, the state of the cavity returns to its ground
state, allowing new sequential operations. The particle and wave behavior,
which are verified in a single experimental setup, are postselected after the
atomic states are selectively detected.


title:
The Atacama Cosmology Telescope: Beam Measurements and the Microwave
  Brightness Temperatures of Uranus and Saturn

abstract:
  We describe the measurement of the beam profiles and window functions for the
Atacama Cosmology Telescope (ACT), which operated from 2007 to 2010 with
kilo-pixel bolometer arrays centered at 148, 218, and 277 GHz. Maps of Saturn
are used to measure the beam shape in each array and for each season of
observations. Radial profiles are transformed to Fourier space in a way that
preserves the spatial correlations in the beam uncertainty, to derive window
functions relevant for angular power spectrum analysis. Several corrections are
applied to the resulting beam transforms, including an empirical correction
measured from the final CMB survey maps to account for the effects of mild
pointing variation and alignment errors. Observations of Uranus made regularly
throughout each observing season are used to measure the effects of atmospheric
opacity and to monitor deviations in telescope focus over the season. Using the
WMAP-based calibration of the ACT maps to the CMB blackbody, we obtain precise
measurements of the brightness temperatures of the Uranus and Saturn disks at
effective frequencies of 149 and 219 GHz. For Uranus we obtain thermodynamic
brightness temperatures T_U^{149} = 106.7 \pm 2.2 K and T_U^{219} = 100.1 \pm
3.1 K. For Saturn, we model the effects of the ring opacity and emission using
a simple model and obtain resulting (unobscured) disk temperatures of T_S^{149}
= 137.3 \pm 3.2 K and T_S^{219} = 137.3 \pm 4.7 K.


title:
Tail asymptotics for the supremum of a random walk when the mean is not
  finite

abstract:
  We consider the sums $S_n=\xi_1+\cdots+\xi_n$ of independent identically
distributed random variables. We do not assume that the $\xi$'s have a finite
mean. Under subexponential type conditions on distribution of the summands, we
find the asymptotics of the probability ${\bf P}\{M>x\}$ as $x\to\infty$,
provided that $M=\sup\{S_n,\ n\ge1\}$ is a proper random variable. Special
attention is paid to the case of tails which are regularly varying at infinity.
  We provide some sufficient conditions for the integrated weighted tail
distribution to be subexponential. We supplement these conditions by a number
of examples which cover both the infinite- and the finite-mean cases. In
particular, we show that subexponentiality of distribution $F$ does not imply
subexponentiality of its integrated tail distribution $F^I$.


title:
Entanglement subspaces, trial wavefunctions, and special Hamiltonians in
  the fractional quantum Hall effect

abstract:
  We consider spaces of trial wavefunctions for ground states and edge
excitations in the fractional quantum Hall effect that can be obtained in
various ways. In one way, functions are obtained by analyzing the entanglement
of the ground state wavefunction, partitioned into two parts. In another,
functions are defined by the way in which they vanish as several coordinates
approach the same value, or by a projection-operator Hamiltonian that enforces
those conditions. In a third way, functions are given by conformal blocks from
a conformal field theory (CFT). These different spaces of functions are closely
related. The use of CFT methods permits an algebraic formulation to be given
for all of them. In some cases, we can prove that there is a ground state, a
Hamiltonian, and a CFT such that, for any number of particles, all of these
spaces are the same. For such cases, this resolves several questions and
conjectures: it gives a finite-size bulk-edge correspondence, and we can use
the analysis of functions to construct a projection-operator Hamiltonian that
produces those functions as zero-energy states. For a model related to the N=1
superconformal algebra, the corresponding Hamiltonian imposes vanishing
properties involving only three particles; for this we determine all the
wavefunctions explicitly. We do the same for a sequence of models involving the
M(3,p) Virasoro minimal models that has been considered previously, using
results from the literature. We exhibit the Hamiltonians for the first few
cases of these. The techniques we introduce can be applied in numerous examples
other than those considered here.

categories: cond-mat.mes-hall hep-th math-ph math.MP quant-ph


title: Gamma Rays from Top-Mediated Dark Matter Annihilations

abstract:
  Lines in the energy spectrum of gamma rays are a fascinating experimental
signal, which are often considered "smoking gun" evidence of dark matter
annihilation. The current generation of gamma ray observatories are currently
closing in on parameter space of great interest in the context of dark matter
which is a thermal relic. We consider theories in which the dark matter's
primary connection to the Standard Model is via the top quark, realizing strong
gamma ray lines consistent with a thermal relic through the forbidden channel
mechanism proposed in the Higgs in Space Model. We consider realistic
UV-completions of the Higgs in Space and related theories, and show that a rich
structure of observable gamma ray lines is consistent with a thermal relic as
well as constraints from dark matter searches and the LHC. Particular attention
is paid to the one loop contributions to the continuum gamma rays, which can
easily swamp the line signals in some cases, and have been largely overlooked
in previous literature.


title: Classical and quantum-mechanical phase space distributions

abstract:
  We examine the notion of nonclassicality in terms of quasiprobability
distributions. In particular, we do not only ask if a specific quasiprobability
can be interpreted as a classical probability density, but require that
characteristic features of classical electrodynamics are resembled. We show
that the only quasiprobabilities which correctly describe the superposition
principle of classical electromagnetic fields are the $s$-parameterized
quasiprobabilities. Furthermore, the Glauber-Sudarshan P function is the only
quantum-mechanical quasiprobability which is transformed at a classical
attenuator in the same way as a classical probability distribution. This result
strengthens the definition of nonclassicality in terms of the P function, in
contrast to possible definitions in terms of other quasiprobabilities.


title:
Tunnel conductance spectroscopy via harmonic generation in a hybrid
  capacitor device

abstract:
  We address the measurement of density of states within and beyond the
superconducting gap in tunnel-coupled finite-size nanostructures using a
capacitive method. Third-harmonic generation is used to yield the full
differential conductance spectrum without destruction of the low dimensionality
otherwise induced by intimate ohmic coupling to an electrode. The method is
particularly relevant to attempts to discern the presence of the fragile
Majorana quasiparticle at the end of spin-orbit-coupled nanowires in
appropriate magnetic field conditions by their signature mid-gap density of
states.


title: Defect annihilation and proliferation in active nematics

abstract:
  Liquid crystals inevitably possess topological defect excitations generated
through boundary conditions, applied fields or in quenches to the ordered
phase. In equilibrium pairs of defects coarsen and annihilate as the uniform
ground state is approached. Here we show that defects in active liquid crystals
exhibit profoundly different behavior, depending on the degree of activity and
its contractile or extensile character. While contractile systems enhance the
annihilation dynamics of passive systems, extensile systems act to drive
defects apart so that they swarm around in the manner of topologically
well-characterized self-propelled particles. We develop a simple analytical
model for the defect dynamics which reproduces the key features of both the
numerical solutions and recent experiments on microtuble-kinesin assemblies.


title:
Double-core Excitations in Formamide Can Be Probed by X-ray
  Double-quantum-coherence Spectroscopy

abstract:
  The attosecond, time-resolved X-ray double-quantum-coherence (XDQC) four wave
mixing signals of formamide at the nitrogen and oxygen K-edges are simulated
using restricted excitation window time-dependent density functional theory
(REW-TDDFT) and the excited core hole (XCH) approximation. These signals,
induced by core exciton coupling, are particularly sensitive to the level of
treatment of electron correlation, thus providing direct experimental
signatures of electron core hole many-body effects and a test of electronic
structure theories.


title: Clustering-based redshift estimation: method and application to data

abstract:
  We present a data-driven method to infer the redshift distribution of an
arbitrary dataset based on spatial cross-correlation with a reference
population and we apply it to various datasets across the electromagnetic
spectrum to show its potential and limitations. Our approach advocates the use
of clustering measurements on all available scales, in contrast to previous
works focusing only on linear scales. We also show how its accuracy can be
enhanced by optimally sampling a dataset within its photometric space rather
than applying the estimator globally. We show that the ultimate goal of this
technique is to characterize the mapping between the space of photometric
observables and redshift space as this characterization then allows us to infer
the clustering-redshift p.d.f. of a single galaxy. We apply this technique to
estimate the redshift distributions of luminous red galaxies and emission line
galaxies from the SDSS, infrared sources from WISE and radio sources from
FIRST. We show that consistent redshift distributions are found using both
quasars and absorber systems as reference populations. This technique brings
valuable information on the third dimension of astronomical datasets. It is
widely applicable to a large range of extra-galactic surveys.


title: Cosmic ray induced micro black hole showers

abstract:
  Extended air showers originate from interactions between ultra-high-energy
cosmic rays and nuclei in the Earth's atmosphere. At present there are some
discrepancies between experimental observed properties of these air showers and
theoretical predictions obtained by using standard hadronic interaction models
for cosmic ray primaries with laboratory energies above 10^5 - 10^6 TeV. In
this contribution, we will present a preliminary discussion of the possibility
(in the framework of TeV gravity models) that shower development may begin with
the production of a microscopic black hole (MBH) at the moment of the primary
collision, which then evaporates and decays, by emitting gravitons and Standard
Model quanta. From our preliminary investigations it appears that lepton
distributions are more likely to reveal the presence of a MBH than photon
distributions.


title: Quantum Steering Ellipsoids

abstract:
  The quantum steering ellipsoid of a two-qubit state is the set of Bloch
vectors that Bob can collapse Alice's qubit to, considering all possible
measurements on his qubit. We provide an elementary construction of the
ellipsoid for arbitrary states, calculate its volume, and explain how this
geometric representation can be made faithful. The representation provides a
range of new results, and uncovers new features, such as the existence of
"incomplete steering" in separable states. We show that entanglement can be
analysed in terms of three geometric features of the ellipsoid, and prove that
a state is separable if and only if it obeys a "nested tetrahedron" condition.


title: Intersections of SLE Paths: the double and cut point dimension of SLE

abstract:
  We compute the almost-sure Hausdorff dimension of the double points of
chordal SLE_kappa for kappa > 4, confirming a prediction of Duplantier-Saleur
(1989) for the contours of the FK model. We also compute the dimension of the
cut points of chordal SLE_kappa for kappa > 4 as well as analogous dimensions
for the radial and whole-plane SLE_kappa(rho) processes for kappa > 0. We
derive these facts as consequences of a more general result in which we compute
the dimension of the intersection of two flow lines of the formal vector field
e^{ih/chi}, where h is a Gaussian free field and chi > 0, of different angles
with each other and with the domain boundary.


title:
Cosmology from the Thermal Sunyaev-Zel'dovich Power Spectrum: Primordial
  non-Gaussianity and Massive Neutrinos

abstract:
  We carry out a comprehensive analysis of the possible constraints on
cosmological and astrophysical parameters achievable with measurements of the
thermal Sunyaev-Zel'dovich (tSZ) power spectrum from upcoming full-sky CMB
observations, with a particular focus on one-parameter extensions to the LCDM
standard model involving local primordial non-Gaussianity (described by fNL)
and massive neutrinos (described by Mnu). We include all of the relevant
physical effects due to these additional parameters, including the change to
the halo mass function and the scale-dependent halo bias induced by local
primordial non-Gaussianity. [...] We compute forecasts for Planck, PIXIE, and a
cosmic variance (CV)-limited experiment, using multifrequency subtraction to
remove foregrounds and implementing two masking criteria based on the ROSAT and
eROSITA cluster catalogs to reduce the significant CV errors at low multipoles.
We find that Planck can detect the tSZ power spectrum with >30-sigma
significance, regardless of the masking scenario. However, neither Planck or
PIXIE is likely to provide competitive constraints on fNL from the tSZ power
spectrum due to CV noise at low-ell overwhelming the unique signature of the
scale-dependent bias. A future CV-limited experiment could provide a 3-sigma
detection of fNL~37, which is the WMAP9 maximum-likelihood result. The outlook
for neutrino masses is more optimistic: Planck can reach levels comparable to
the current upper bounds ~<0.3 eV with conservative assumptions about the
intracluster medium (ICM); stronger ICM priors could allow Planck to provide
1-2-sigma evidence for massive neutrinos from the tSZ power spectrum, depending
on the true value of the sum of the neutrino masses. We also forecast a ~<10%
constraint on the outer slope of the ICM pressure profile using the unmasked
Planck tSZ power spectrum.


title:
Removal of two large scale Cosmic Microwave Background anomalies after
  subtraction of the Integrated Sachs Wolfe effect

abstract:
  Though debated, the existence of claimed large-scale anomalies in the CMB is
not totally dismissed. In parallel to the debate over their statistical
significance, recent work focussed on masks and secondary anisotropies as
potential sources of these anomalies. In this work we investigate
simultaneously the impact of the method used to account for masked regions and
the impact of the ISW effect, which is the large-scale secondary anisotropy
most likely to affect the CMB anomalies. In this sense, our work is an update
of both Francis & Peacock 2010 and Kim et al. 2012. Our aim is to identify
trends in CMB data with different mask treatments. We reconstruct the ISW
signal due to 2MASS and NVSS galaxies. We account for missing data using the
sparse inpainting technique of Abrial et al. 2008 and sparse inpainting of the
CMB, LSS and ISW and find that it constitutes a bias-free reconstruction method
suitable to study large-scale statistical isotropy and the ISW effect. We focus
on three large-scale CMB anomalies: the low quadrupole, the quad/oct alignment,
and the octopole planarity. After sparse inpainting, the low quadrupole becomes
more anomalous, whilst the quad/oct alignment becomes less anomalous. The
significance of the low quadrupole is unchanged after subtraction of the ISW
effect, while the trend is that the quad/oct alignment has reduced
significance, yet other hypotheses remain possible as well (e.g. exotic
physics). Our results also suggest that both of these anomalies may be due to
the quadrupole alone. The octopole planarity significance is also reduced after
inpainting and after ISW subtraction, however, we do not find that it was very
anomalous to start with. In the spirit of reproducible research, we make all
codes and resulting products which constitute main results of this paper public
here: http://www.cosmostat.org/anomaliesCMB.html.


title: WMAP Observations of Planck ESZ Clusters

abstract:
  We examine the Sunyaev--Zeldovich (SZ) effect in the 7-yr Wilkinson Microwave
Anisotropy Probe (WMAP) data by cross-correlating it with the Planck
Early-release Sunyaev--Zeldovich catalog. Our analysis proceeds in two parts.
We first perform a stacking analysis in which the filtered WMAP data are
averaged at the locations of the 175 Planck clusters. We then perform a
regression analysis to compare the mean amplitude of the SZ signal, Y_{500}, in
the WMAP data to the corresponding amplitude in the Planck data. The aggregate
Planck clusters are detected in the 7-yr WMAP data with a signal-to-noise ratio
of 16.3. In the regression analysis we find that the SZ amplitude measurements
agree to better than 25%: $a=1.23 \pm 0.18$ for the fit Y^{wmap}_{500} =
aY^{planck}_{500}$.


title: Coevents as Beables

abstract:
  Sorkin's coevents can be thought of as the `beables' of a quantum histories
theory; in this paper we study the 'logical' implications of taking this claim
at face value, constructing a propositional lattice for the space of coevents
applicable to a given histories theory and comparing it to the more traditional
propositional lattice of events. In particular we focus on multiplicative
coevents, and find that the precise nature of their anhomomorphism leads to a
particularly simple relationship between the two propositional lattices.
Finally, we notice that our constructions contain elements intuitively similar
to topos nations of truth values and use this to suggest a means of applying
Isham's topos theoretic constructions to multiplicative coevents.


title:
Temperature effect on the small-to-large crossover length-scale of
  hydrophobic hydration

abstract:
  The thermodynamics of hydration changes gradually from entropic for small
solutes to enthalpic for large ones. The small-to-large crossover lengthscale
of hydrophobic hydration depends on the thermodynamic conditions of the solvent
such as temperature, pressure, presence of additives, etc... We attempt to shed
some light on the temperature dependence of the crossover lengthscale by using
a probabilistic approach to water hydrogen bonding that allows one to obtain an
analytic expression for the number of bonds per water molecule as a function of
both its distance to a solute and solute radius. Incorporating that approach
into the density functional theory, one can examine the solute size effects on
its hydration over the entire small-to-large lengthscale range at different
temperatures. Knowing the dependence of the hydration free energy on
temperature and solute size, one can obtain its enthalpic and entropic
contributions as functions of temperature and solute size. These function can
provide interesting insight into the temperature dependence of the crossover
lengthscale of hydrophobic hydration. The model was applied to the hydration of
spherical particles of various radii in water in the temperature range from
T=293.15 K to T=333.15 K. The model predictions for the temperature dependence
of the hydration free energy of small hydrophobes are consistent with the
experimental and simulational data. Three alternative definitions for the
small-to-large crossover length-scale of hydrophobic hydration are proposed,
and their temperature dependence is obtained. Depending on the definition and
temperature, the small-to-large crossover in the hydration mechanism is
predicted to occur for hydrophobes of radii from one to several nanometers.
Independent of its definition, the crossover length-scale is predicted to
decrease with increasing temperature.


title:
Extended Prigozhin theorem: method for universal characterization of
  complex system evolution

abstract:
  Evolution of arbitrary stochastic system was considered in frame of phase
transition description. Concept of Reynolds parameter of hydrodynamic motion
was extended to arbitrary complex system. Basic phase parameter was expressed
through power of energy, injected into system and power of energy, dissipated
through internal nonlinear mechanisms. It was found out that basic phase
parameter as control parameter must be delimited for two types of system -
accelerator and decelerator. It was suggested to select zero state entropy on
through condition of zero value for entropy production. Zero state introduces
universal principle of disorder characterization. On basis of self organization
theorem we have derived relations for entropy production behavior in the
vicinity stationary state of system. Advantage of these relations in comparison
to classical Prigozhin theorem is versatility of their application to arbitrary
nonlinear systems. It was found out that extended Prigozhin theorem introduces
two relations for accelerator and decelerator correspondingly, which remarks
their quantitative difference. At the same time classic Prigozhin theorem makes
possible description of linear decelerator only. For unstable motion it
corresponds to strange attractor.


title:
How effective is new variable modified Chaplygin gas to play the role of
  dark energy- A dynamical system analysis in RS II Brane model

abstract:
  Motivated by some previous works of Rudra et al we set to explore the
background dynamics when dark energy in the form of New Variable Modified
Chaplygin gas is coupled to dark matter with a suitable interaction in the
universe described by brane cosmology. The main idea is to find out the
efficiency of New variable modified Chaplygin gas to play the role of DE. As a
result we resort to the technique of comparison with standard dark energy
models. Here the RSII brane model have been considered as the gravity theory.
An interacting model is considered in order to search for a possible solution
of the cosmic coincidence problem. A dynamical system analysis is performed
because of the high complexity of the system . The statefinder parameters are
also calculated to classify the dark energy model. Graphs and phase diagrams
are drawn to study the variations of these parameters and get an insight into
the effectiveness of the dark energy model. It is also seen that the background
dynamics of New Variable Modified Chaplygin gas is consistent with the late
cosmic acceleration. After performing an extensive mathematical analysis, we
are able to constrain the parameters of new variable modified Chaplygin gas as
$m<n$ to produce the best possible results. Future singularities are studied
and it is found that the model has a tendency to result in such singularities
unlike the case of generalized cosmic Chaplygin gas. Our investigation leads us
to the fact that New Variable Modified Chaplygin gas is not as effective as
other Chaplygin gas models to play the role of dark energy.


title:
Topological properties of sets represented by an inequality involving
  distances

abstract:
  Consider a set represented by an inequality. An interesting phenomenon which
occurs in various settings in mathematics is that the interior of this set is
the subset where strict inequality holds, the boundary is the subset where
equality holds, and the closure of the set is the closure of its interior. This
paper discusses this phenomenon assuming the set is a Voronoi cell induced by
given sites (subsets), a geometric object which appears in many fields of
science and technology and has diverse applications. Simple counterexamples
show that the discussed phenomenon does not hold in general, but it is
established in a wide class of cases. More precisely, the setting is a
(possibly infinite dimensional) uniformly convex normed space with arbitrary
positively separated sites. An important ingredient in the proof is a strong
version of the triangle inequality due to Clarkson (1936), an interesting
inequality which has been almost totally forgotten.


title:
Dual-Conformal Regularization of Infrared Loop Divergences and the
  Chiral Box Expansion

abstract:
  We revisit the familiar construction of one-loop scattering amplitudes via
generalized unitarity in light of the recently understood properties of loop
integrands prior to their integration. We show how in any four-dimensional
quantum field theory, the integrand-level factorization of infrared divergences
leads to twice as many constraints on integral coefficients than are visible
from the integrated expressions. In the case of planar, maximally
supersymmetric Yang-Mills amplitudes, we demonstrate that these constraints are
both sufficient and necessary to imply the finiteness and dual-conformal
invariance of the ratios of scattering amplitudes. We present a novel
regularization of the scalar box integrals which makes dual-conformal
invariance of finite observables manifest term by term, and describe how this
procedure can be generalized to higher loop-orders. Finally, we describe how
the familiar scalar boxes at one-loop can be upgraded to `chiral boxes'
resulting in a manifestly infrared-factorized, box-like expansion for all
one-loop integrands in planar, N=4 super Yang-Mills. Accompanying this note is
a Mathematica package which implements our results, and allows for the
efficient numerical evaluation of any one-loop amplitude or ratio function.


title:
Host Star Properties and Transit Exclusion for the HD 38529 Planetary
  System

abstract:
  The transit signature of exoplanets provides an avenue through which
characterization of exoplanetary properties may be undertaken, such as studies
of mean density, structure, and atmospheric composition. The Transit Ephemeris
Refinement and Monitoring Survey (TERMS) is a program to expand the catalog of
transiting planets around bright host stars by refining the orbits of known
planets discovered with the radial velocity technique. Here we present results
for the HD 38529 system. We determine fundamental properties of the host star
through direct interferometric measurements of the radius and through
spectroscopic analysis. We provide new radial velocity measurements that are
used to improve the Keplerian solution for the two known planets, and we find
no evidence for a previously postulated third planet. We also present 12 years
of precision robotic photometry of HD 38529 that demonstrate the inner planet
does not transit and the host star exhibits cyclic variations in seasonal mean
brightness with a timescale of approximately six years.


title:
The Outer Halo of the Nearest Giant Elliptical: A VLT/VIMOS Survey of
  the Resolved Stellar Populations in Centaurus A to 85 kpc

abstract:
  We present the first deep survey of resolved stellar populations in the
remote outer halo of our nearest giant elliptical (gE), Centaurus A (D=3.8
Mpc). Using the VIMOS/VLT optical camera, we obtained deep photometry for four
fields along the major and minor axes at projected elliptical radii of ~30-85
kpc (corresponding to ~5-14 R_{eff}). We use resolved star counts to map the
spatial and colour distribution of red giant branch (RGB) stars down to ~2
magnitudes below the RGB tip. We detect an extended halo out to the furthermost
elliptical radius probed (~85 kpc or ~14 R_{eff}), demonstrating the vast
extent of this system. We detect a localised substructure in these parts,
visible in both (old) RGB and (intermediate-age) luminous asymptotic giant
branch stars, and there is some evidence that the outer halo becomes more
elliptical and has a shallower surface brightness profile. We derive
photometric metallicity distribution functions for halo RGB stars and find
relatively high median metallicity values ([Fe/H]_{med} -0.9 to -1.0 dex) that
change very little with radius over the extent of our survey. Radial
metallicity gradients are measured to be ~-0.002 to -0.004 dex/kpc and the
fraction of metal-poor stars (defined as [Fe/H]<-1.0) is ~40-50% at all radii.
We discuss these findings in the context of galaxy formation models for the
buildup of gE haloes.


title:
Line Emission from Radiation-Pressurized HII Region II: Dynamics and
  Population Synthesis

abstract:
  Optical and infrared emission lines from HII regions are an important
diagnostic used to study galaxies, but interpretation of these lines requires
significant modeling of both the internal structure and dynamical evolution of
the emitting regions. Most of the models in common use today assume that HII
region dynamics are dominated by the expansion of stellar wind bubbles, and
have neglected the contribution of radiation pressure to the dynamics, and in
some cases also to the internal structure. However, recent observations of
nearby galaxies suggest that neither assumption is justified, motivating us to
revisit the question of how HII region line emission depends on the physics of
winds and radiation pressure. In a companion paper we construct models of
single HII regions including and excluding radiation pressure and winds, and in
this paper we describe a population synthesis code that uses these models to
simulate galactic collections of HII regions with varying physical parameters.
We show that the choice of physical parameters has significant effects on
galactic emission line ratios, and that in some cases the line ratios can
exceed previously claimed theoretical limits. Our results suggest that the
recently-reported offset in line ratio values between high-redshift
star-forming galaxies and those in the local universe may be partially
explained by the presence of large numbers of radiation pressured-dominated HII
regions within them.


title: Identification of transitional disks in Chamaeleon with Herschel

abstract:
  Transitional disks are circumstellar disks with inner holes that in some
cases are produced by planets and/or substellar companions in these systems.
For this reason, these disks are extremely important for the study of planetary
system formation. The Herschel Space Observatory provides an unique opportunity
for studying the outer regions of protoplanetary disks. In this work we update
previous knowledge on the transitional disks in the Chamaeleon I and II regions
with data from the Herschel Gould Belt Survey. We propose a new method for
transitional disk classification based on the WISE 12 micron-PACS 70 micron
color, together with inspection of the Herschel images. We applied this method
to the population of Class II sources in the Chamaeleon region and studied the
spectral energy distributions of the transitional disks in the sample. We also
built the median spectral energy distribution of Class II objects in these
regions for comparison with transitional disks. The proposed method allows a
clear separation of the known transitional disks from the Class II sources. We
find 6 transitional disks, all previously known, and identify 5 objects
previously thought to be transitional as possibly non-transitional. We find
higher fluxes at the PACS wavelengths in the sample of transitional disks than
those of Class II objects. We show the Herschel 70 micron band to be an
efficient tool for transitional disk identification. The sensitivity and
spatial resolution of Herschel reveals a significant contamination level among
the previously identified transitional disk candidates for the two regions,
which calls for a revision of previous samples of transitional disks in other
regions. The systematic excess found at the PACS bands could be a result of the
mechanism that produces the transitional phase, or an indication of different
evolutionary paths for transitional disks and Class II sources.


title: A Way Forward for Cosmic Shear: Monte-Carlo Control Loops

abstract:
  Weak lensing by large scale structure or 'cosmic shear' is a potentially
powerful cosmological probe to shed new light on Dark Matter, Dark Energy and
Modified Gravity. It is based on the weak distortions induced by large-scale
structures on the observed shapes of distant galaxies through gravitational
lensing. While the potentials of this purely gravitational effect are great,
results from this technique have been hampered because the measurement of this
weak effect is difficult and limited by systematics effects. In particular, a
demanding step is the measurement of the weak lensing shear from wide field CCD
images of galaxies. We describe the origin of the problem and propose a way
forward for cosmic shear. Our proposed approach is based on Monte-Carlo Control
Loops and draws upon methods widely used in particle physics and engineering.
We describe the control loop scheme and show how it provides a calibration
method based on fast image simulations tuned to reproduce the statistical
properties of a specific cosmic shear data set. Through a series of iterative
loops and diagnostic tests, the Monte Carlo image simulations are made robust
to perturbations on modeling input parameters and thus to systematic effects.
We discuss how this approach can make the problem tractable and unleash to full
potential of cosmic shear for cosmology.


title:
Potassium in globular cluster stars: comparing normal clusters to the
  peculiar cluster NGC 2419

abstract:
  Two independent studies recently uncovered two distinct populations among
giants in the distant, massive globular cluster (GC) NGC 2419. One of these
populations has normal magnesium (Mg) and potassium (K) abundances for halo
stars: enhanced Mg and roughly solar K. The other population has extremely
depleted Mg and very enhanced K. To better anchor the peculiar NGC 2419
chemical composition, we have investigated the behavior of K in a few red giant
branch stars in NGC 6752, NGC 6121, NGC 1904, and omega Cen. To verify that the
high K abundances are intrinsic and not due to some atmospheric features in
giants, we also derived K abundances in less evolved turn-off and subgiant
stars of clusters 47 Tuc, NGC 6752, NGC 6397, and NGC 7099. We normalized the K
abundance as a function of the cluster metallicity using 21 field stars
analyzed in a homogeneous manner. For all GCs of our sample, the stars lie in
the K-Mg abundance plane on the same locus occupied by the Mg-normal population
in NGC 2419 and by field stars. This holds both for giants and less evolved
stars. At present, NGC 2419 seems unique among GCs.


title:
Molecular Line Emission from Multifluid Shock Waves. I. Numerical
  Methods and Benchmark Tests

abstract:
  We describe a numerical scheme for studying time-dependent, multifluid,
magnetohydrodynamic shock waves in weakly ionized interstellar clouds and
cores. Shocks are modeled as propagating perpendicular to the magnetic field
and consist of a neutral molecular fluid plus a fluid of ions and electrons.
The scheme is based on operator splitting, wherein time integration of the
governing equations is split into separate parts. In one part independent
homogeneous Riemann problems for the two fluids are solved using Godunov's
method. In the other equations containing the source terms for transfer of
mass, momentum, and energy between the fluids are integrated using standard
numerical techniques. We show that, for the frequent case where the thermal
pressures of the ions and electrons are << magnetic pressure, the Riemann
problems for the neutral and ion-electron fluids have a similar mathematical
structure which facilitates numerical coding. Implementation of the scheme is
discussed and several benchmark tests confirming its accuracy are presented,
including (i) MHD wave packets ranging over orders of magnitude in length and
time scales; (ii) early evolution of mulitfluid shocks caused by two colliding
clouds; and (iii) a multifluid shock with mass transfer between the fluids by
cosmic-ray ionization and ion-electron recombination, demonstrating the effect
of ion mass loading on magnetic precursors of MHD shocks. An exact solution to
a MHD Riemann problem forming the basis for an approximate numerical solver
used in the homogeneous part of our scheme is presented, along with derivations
of the analytic benchmark solutions and tests showing the convergence of the
numerical algorithm.


title:
Line Emission from Radiation-Pressurized HII Regions I: Internal
  Structure and Line Ratios

abstract:
  The emission line ratios [OIII]5007/H-beta and [NII]6584/H-alpha have been
adopted as an empirical way to distinguish between the fundamentally different
mechanisms of ionization in emission-line galaxies. However, detailed
interpretation of these diagnostics requires calculations of the internal
structure of the emitting HII regions, and these calculations depend on the
assumptions one makes about the relative importance of radiation pressure and
stellar winds. In this paper we construct a grid of quasi-static HII region
models to explore how choices about these parameters alter HII regions'
emission line ratios. We find that, when radiation pressure is included in our
models, HII regions reach a saturation point beyond which further increases in
the luminosity of the driving stars does not produce any further increase in
effective ionization parameter, and thus does not yield any further alteration
in an HII region's line ratio. We also show that, if stellar winds are assumed
to be strong, the maximum possible ionization parameter is quite low. As a
result of this effect, it is inconsistent to simultaneously assume that HII
regions are wind-blown bubbles and that they have high ionization parameters;
some popular HII region models suffer from this inconsistency. Our work in this
paper provides a foundation for a companion paper in which we embed the model
grids we compute here within a population synthesis code that enables us to
compute the integrated line emission from galactic populations of HII regions.


title: Dust extinction for an unbiased sample of GRB afterglows

abstract:
  In this paper we compute rest-frame extinctions for the afterglows of a
sample of gamma-ray bursts complete in redshift. The selection criteria of the
sample are based on observational high-energy parameters of the prompt emission
and therefore our sample should not be biased against dusty sight-lines. It is
therefore expected that our inferences hold for the general population of
gamma-ray bursts. Our main result is that the optical/near-infrared extinction
of gamma-ray burst afterglows in our sample does not follow a single
distribution. 87% of the events are absorbed by less than 2 mag, and 50% suffer
from less than 0.3-0.4 mag extinction. The remaining 13% of the afterglows are
highly absorbed. The true percentage of gamma-ray burst afterglows showing high
absorption could be even higher since a fair fraction of the events without
reliable redshift measurement are probably part of this class. These events may
be due to highly dusty molecular clouds/star forming regions associated with
the gamma-ray burst progenitor or along the afterglow line of sight, and/or to
massive dusty host galaxies. No clear evolution in the dust extinction
properties is evident within the redshift range of our sample, although the
largest extinctions are at z~1.5-2, close to the expected peak of the star
formation rate. Those events classified as dark are characterized, on average,
by a higher extinction than typical events in the sample. A correlation between
optical/near-infrared extinction and hydrogen-equivalent column density based
on X-ray studies is shown although the observed NH appears to be well in excess
compared to those observed in the Local Group. Dust extinction does not seem to
correlate with GRB energetics or luminosity.


title: Stability of local quantum dissipative systems

abstract:
  Open quantum systems weakly coupled to the environment are modeled by
completely positive, trace preserving semigroups of linear maps. The generators
of such evolutions are called Lindbladians. In the setting of quantum many-body
systems on a lattice it is natural to consider Lindbladians that decompose into
a sum of local interactions with decreasing strength with respect to the size
of their support. For both practical and theoretical reasons, it is crucial to
estimate the impact that perturbations in the generating Lindbladian, arising
as noise or errors, can have on the evolution. These local perturbations are
potentially unbounded, but constrained to respect the underlying lattice
structure. We show that even for polynomially decaying errors in the
Lindbladian, local observables and correlation functions are stable if the
unperturbed Lindbladian has a unique fixed point and a mixing time which scales
logarithmically with the system size. The proof relies on Lieb-Robinson bounds,
which describe a finite group velocity for propagation of information in local
systems. As a main example, we prove that classical Glauber dynamics is stable
under local perturbations, including perturbations in the transition rates
which may not preserve detailed balance.


title: Fluctuation-induced pair density wave in itinerant ferromagnets

abstract:
  Magnetic fluctuations near to quantum criticality can have profound effects.
They lead to characteristic scaling at high temperature which may ultimately
give way to a reconstruction of the phase diagram and the formation of new
phases at low temperatures. The ferromagnet UGe2 is unstable to p-wave
superconducting order -- an effect presaged by the superfluidity in He3 --
whereas in CeFePO fluctuations drive the formation of spiral magnetic order.
Here we develop a general quantum order-by-disorder description of these
systems that encompasses both of these instabilities within a unified
framework. This allows us to demonstrate that in fact these instabilities
intertwine to form a new phase, a pair density wave.


title: Cosmic Ray Streaming in Clusters of Galaxies

abstract:
  The observed bimodality in radio luminosity in galaxy clusters is puzzling.
We investigate the possibility that cosmic-ray (CR) streaming in the
intra-cluster medium can 'switch off' hadronically induced radio and gamma-ray
emission. For self-confined CRs, this depends on the source of MHD wave
damping: if only non-linear Landau damping operates, then CRs stream on the
slow Alfvenic timescale, but if turbulent wave damping operates, super-Alfvenic
streaming is possible. As turbulence increases, it promotes outward streaming
more than it enables inward turbulent advection. Curiously, the CR flux is
independent of $\nabla f$ (as long as it is non-zero) and depends only on
plasma parameters; this enables radio halos with flat inferred CR profiles to
turn off. We perform 1D time-dependent calculations of a radio mini-halo
(Perseus) and giant radio halo (Coma) and find that both diminish in radio
luminosity by an order of magnitude in several hundred Myr, given plausible
estimates for the magnetic field in the outskirts of the cluster. Due to the
energy dependence of CR streaming, spectral curvature develops, and radio halos
turn off more slowly at low frequencies -- properties consistent with
observations. Similarly, CR streaming rapidly turns off gamma-ray emission at
the high-energies probed by Cherenkov telescopes, but not at the low energies
probed by Fermi. CR mediated wave-heating of the ICM is unaffected, as it is
dominated by ~GeV CRs which stream Alfvenically.


title: Maximum Entropy deconvolution of Primordial Power Spectrum

abstract:
  It is well known that CMB temperature anisotropies and polarization can be
used to probe the metric perturbations in the early universe. Presently, there
exist neither any observational detection of tensor modes of primordial metric
perturbations nor of primordial non-Gaussianity. In such a scenario, primordial
power spectrum of scalar metric perturbations is the only correlation function
of metric perturbations (presumably generated during inflation) whose effects
can be directly probed through various observations. To explore the possibility
of any deviations from the simplest picture of the era of cosmic inflation in
the early universe, it thus becomes extremely important to uncover the
amplitude and shape of this (only available) correlation sufficiently well. In
the present work, we attempt to reconstruct the primordial power spectrum of
scalar metric perturbations using the binned (uncorrelated) CMB temperature
anisotropies data using the Maximum Entropy Method (MEM) to solve the
corresponding inverse problem. Our analysis shows that, given the current CMB
data, there are no convincing reasons to believe that the primordial power
spectrum of scalar metric perturbations has any significant features.


title:
Classification of integral modular categories of Frobenius-Perron
  dimension pq^4 and p^2q^2

abstract:
  We classify integral modular categories of dimension pq^4 and p^2q^2 where p
and q are distinct primes. We show that such categories are always
group-theoretical except for categories of dimension 4q^2. In these cases there
are well-known examples of non-group-theoretical categories, coming from
centers of Tambara-Yamagami categories and quantum groups. We show that a
non-group-theoretical integral modular category of dimension 4q^2 is equivalent
to either one of these well-known examples or is of dimension 36 and is
twist-equivalent to fusion categories arising from a certain quantum group.


title: Strain controlled oxygen vacancy formation and ordering in CaMnO$_3$

abstract:
  We use first-principles calculations to investigate the stability of
bi-axially strained \textit{Pnma} perovskite CaMnO$_3$ towards the formation of
oxygen vacancies. Our motivation is provided by promising indications that
novel material properties can be engineered by application of strain through
coherent heteroepitaxy in thin films. While it is usually assumed that such
epitaxial strain is accommodated primarily by changes in intrinsic lattice
constants, point defect formation is also a likely strain relaxation mechanism.
This is particularly true at the large strain magnitudes ($>$4%) which
first-principles calculations often suggest are required to induce new
functionalities. We find a strong dependence of oxygen vacancy defect formation
energy on strain, with tensile strain lowering the formation energy consistent
with the increasing molar volume with increasing oxygen deficiency. In
addition, we find that strain differentiates the formation energy for different
lattice sites, suggesting its use as a route to engineering vacancy ordering in
epitaxial thin films.


title: Gauge/Gravity Duality in Heterotic String Theory

abstract:
  Gravity duals for little string theories --- which give rise to
four-dimensional theories that undergo permanent confinement in the infrared
--- have not been studied in great detail. We address this question in the
framework of heterotic SO(32) and E_8 x E_8 string theory, constructing these
backgrounds by wrapping heterotic five-branes on calibrated two-cycles of
non-Kahler resolved conifolds. Related to deformations of the underlying little
string theories, we find numerous analytic solutions preserving N = 1
supersymmetry in four-dimensions. These theories all have non-abelian global
symmetries that generally arise from both the heterotic vector bundle and from
certain orbifold states. In the decoupling limit, we argue that the gravity
duals are given by non-Kahler manifolds that have both blown-up two-cycles and
three-cycles at the origin. We argue this following certain duality sequences
that include M-theory torsional manifolds at an intermediate step, which help
us to construct new type I' gauge/gravity duality pairs. In the M-theory
duality frame, we also elucidate new sequences of flips and flops.


title:
Cloud formation in colliding flows: influence of the choice of cooling
  function

abstract:
  We study the influence of the choice of cooling function on the formation of
molecular clouds in high-resolution three-dimensional simulations of converging
flows. We directly compare the results obtained using the simple, parametrized
cooling function introduced by Koyama & Inutsuka (2002) and used by a number of
converging flow studies with the results of the detailed calculation of the
non-equilibrium chemistry and thermal balance of the gas. We find that a number
of the cloud properties, such as the mass and volume filling fractions of cold
gas, are relatively insensitive to the choice of cooling function. On the other
hand, the cloud morphology and the large-scale velocity distribution of the gas
do strongly depend on the cooling function. We show that the differences that
we see can largely be explained by differences in the way that Lyman-alpha
cooling is treated in the two complementary approaches, and that a proper
non-equilibrium treatment of the ionisation and recombination of the gas is
necessary in order to model the high-temperature cooling correctly.
  We also investigate the properties of the dense clumps formed within the
cloud. In agreement with previous models, we find that the majority of these
clumps are not self-gravitating, suggesting that some form of large-scale
collapse of the cloud may be required in order to produce gravitationally
unstable clumps and hence stars. Overall, the physical properties of the dense
clumps are similar in both simulations, suggesting that they do not depend
strongly on the choice of cooling function. However, we do find a systematic
difference of around 10K in the mean temperatures of the clumps produced by the
two models.


title:
Imaginary action, spinfoam asymptotics and the 'transplanckian' regime
  of loop quantum gravity

abstract:
  It was recently noted that the on-shell Einstein-Hilbert action with
York-Gibbons-Hawking boundary term has an imaginary part, proportional to the
area of the codimension-2 surfaces on which the boundary normal becomes null.
We discuss the extension of this result to first-order formulations of gravity.
As a side effect, we settle the issue of the Holst modification vs. the
Nieh-Yan density by demanding a variational principle with suitable boundary
conditions. We then set out to find the imaginary action in the large-spin
4-simplex limit of the Lorentzian EPRL/FK spinfoam. It turns out that the
spinfoam's effective action indeed has the correct imaginary part, but only if
the Barbero-Immirzi parameter is set to +/- i after the quantum calculation. We
point out an agreement between this effective action and a recent black hole
state-counting calculation in the same limit. Finally, we propose that the
large-spin limit of loop quantum gravity can be viewed as a high-energy
'transplanckian' regime.


title:
The magnetic Laplacian in shrinking tubular neighbourhoods of
  hypersurfaces

abstract:
  The Dirichlet Laplacian between two parallel hypersurfaces in Euclidean
spaces of any dimension in the presence of a magnetic field is considered in
the limit when the distance between the hypersurfaces tends to zero. We show
that the Laplacian converges in a norm-resolvent sense to a Schroedinger
operator on the limiting hypersurface whose electromagnetic potential is
expressed in terms of principal curvatures and the projection of the ambient
vector potential to the hypersurface. As an application, we obtain an effective
approximation of bound-state energies and eigenfunctions in thin quantum
layers.


title:
The displacement and annihilation of macroscopic regions with
  hypervortices in ceramic YBa2Cu3O7-x

abstract:
  Features of the controllable displacement, annihilation, and transformation
of macroscopic regions of a weak frozen magnetic field (FMF) have been
experimentally studied in a plate of granulated ceramic YBa2Cu3O7-x under the
action of the transport current flowing through it. It is shown that the
displacement of regions with an FMF lower than the first critical field of the
ceramic granules (Hc1g) is associated with a relatively weak pinning force of
the hypervortices that is less than the maximum experimentally attainable
Lorenz force. A discussion is presented of the role of the transport current
that not only is one of the conditions for the appearance of the Lorenz force
but also acts on the internal current structure of the local FMF, which in turn
influences its mobility and magnitude. If a local field greater than Hc1g is
frozen in, the experimentally produced Lorenz force is less than the pinning
force of the Abrikosov vortices in the mixed state of the granules, and there
is no displacement of the regions with an FMF.


title:
Ultra-fast transistor-based detectors for precise timing of near
  infrared and THz signals

abstract:
  A whole class of two-color experiments involves intense, short Terahertz
radiation pulses. A fast detector that is sensitive and able to resolve both
near-infrared and Terahertz pulses at the same time is highly desirable. Here
we present the first detector of this kind. The detector element is a
GaAs-based field effect transistor operated at room temperature. THz detection
is successfully demonstrated at frequencies up to 4.9 THz. The THz detection
time constant is shorter than 30 ps, the optical time constant is 150 ps. This
detector is ideally suited for precise, simultaneous resolution of optical and
THz pulses and for pulse characterization of high-power THz pulses up to tens
of kW peak power levels. The dynamic range of the detector was as large as 65
$\pm$ 3 dB/$\sqrt{Hz}$, enabling applications in a large variety of experiments
and setups, also including table-top systems.


title:
Marginal Likelihoods for Distributed Parameter Estimation of Gaussian
  Graphical Models

abstract:
  We consider distributed estimation of the inverse covariance matrix, also
called the concentration or precision matrix, in Gaussian graphical models.
Traditional centralized estimation often requires global inference of the
covariance matrix, which can be computationally intensive in large dimensions.
Approximate inference based on message-passing algorithms, on the other hand,
can lead to unstable and biased estimation in loopy graphical models. In this
paper, we propose a general framework for distributed estimation based on a
maximum marginal likelihood (MML) approach. This approach computes local
parameter estimates by maximizing marginal likelihoods defined with respect to
data collected from local neighborhoods. Due to the non-convexity of the MML
problem, we introduce and solve a convex relaxation. The local estimates are
then combined into a global estimate without the need for iterative
message-passing between neighborhoods. The proposed algorithm is naturally
parallelizable and computationally efficient, thereby making it suitable for
high-dimensional problems. In the classical regime where the number of
variables $p$ is fixed and the number of samples $T$ increases to infinity, the
proposed estimator is shown to be asymptotically consistent and to improve
monotonically as the local neighborhood size increases. In the high-dimensional
scaling regime where both $p$ and $T$ increase to infinity, the convergence
rate to the true parameters is derived and is seen to be comparable to
centralized maximum likelihood estimation. Extensive numerical experiments
demonstrate the improved performance of the two-hop version of the proposed
estimator, which suffices to almost close the gap to the centralized maximum
likelihood estimator at a reduced computational cost.


title: Report on the Workshop on Accelerator R&D for Ultimate Storage Rings

abstract:
  This report summaries the workshop on accelerator R&D for ultimate storage
ring, held in Huairou, Beijing, Oct. 30 to Nov. 1, 2012.


title: Dark Matter Studies Entrain Nuclear Physics

abstract:
  We review theoretically well-motivated dark-matter candidates, and pathways
to their discovery, in the light of recent results from collider physics,
astrophysics, and cosmology. Taken in aggregate, these encourage broader
thinking in regards to possible dark-matter candidates --- dark-matter need not
be made of "WIMPs," i.e., elementary particles with weak-scale masses and
interactions. Facilities dedicated to nuclear physics are well-poised to
investigate certain non-WIMP models. In parallel to this, developments in
observational cosmology permit probes of the relativistic energy density at
early epochs and thus provide new ways to constrain dark-matter models,
provided nuclear physics inputs are sufficiently well-known. The emerging
confluence of accelerator, astrophysical, and cosmological constraints permit
searches for dark-matter candidates in a greater range of masses and
interaction strengths than heretofore possible.


title: Stabilization of the Gear-Grimshaw system on a periodic domain

abstract:
  This paper is devoted to the study of a nonlinear coupled system of two
Korteweg-de Vries equations in a periodic domain under the effect of an
internal damping term. The system was introduced Gear and Grimshaw to model the
interactions of two-dimensional, long, internal gravity waves propagation in a
stratified fluid. Designing a time-varying feedback law and using a Lyapunov
approach we establish the exponential stability of the solutions in Sobolev
spaces of any positive integral order.


title: On Some Elliptic Interface Problems with Nonhomogeneous Jump Conditions

abstract:
  We obtain nontrivial solutions of some elliptic interface problems with
nonhomogeneous jump conditions that arise in localized chemical reactions and
nonlinear neutral inclusions. Our proofs in bounded domains use Morse
theoretical arguments, in particular, critical group computations. An extension
to the whole space is proved using concentration compactness arguments.


title: IEC 61499 vs. 61131: A Comparison Based on Misperceptions

abstract:
  IEC 61131 has been widely accepted in the industrial automation domain.
However, it is claimed that the standard does not address today the new
requirements of complex industrial systems, which include among others,
portability, interoperability, increased reusability and distribution. To
address these restrictions, IEC has initiated the task of developing IEC 61499,
which is presented as a mature technology to enable intelligent automation in
various domains. This standard was not accepted by industry even though it is
highly promoted by the academic community. In this paper, a comparison between
the two standards is presented. We argue that IEC 61499 has been promoted by
academy based on unsubstantiated claims on its main features, i.e.,
reusability, portability, interoperability, event-driven execution. A number of
misperceptions are presented and discussed. Based on this, it is claimed that
IEC 61499 does not provide a solid framework for the next generation of
industrial automation systems.


title:
Minimum BER Power Adjustment and Receiver Design for Distributed
  Space-Time Coded Cooperative MIMO Relaying Systems

abstract:
  An adaptive joint power allocation (JPA) and linear receiver design algorithm
using the minimum bit error rate (MBER) criterion for a cooperative
Multiple-Input Multiple-Output (MIMO) network is proposed. The system employs
multiple relays with Distributed Space-Time Coding (DSTC) schemes and an
Amplify-and-Forward (AF) strategy. It is designed according to a joint
constrained optimization algorithm to determine the MBER power allocation
parameters and the receive filter parameters for each transmitted symbol. The
simulation results indicate that the proposed algorithm obtains performance
gains compared to the equal power allocation systems and the minimum mean
square error (MMSE) designs.


title:
Spatially resolved, high-spectral resolution observation of the K giant
  Aldebaran in the CO first overtone lines with VLTI/AMBER

abstract:
  Aim: We present a high-spatial and high-spectral resolution observation of
the well-studied K giant Aldebaran with AMBER at the Very Large Telescope
Interferometer (VLTI). Our aim is to spatially resolve the outer atmosphere
(so-called MOLsphere) in individual CO first overtone lines and derive its
physical properties, which are important for understanding the mass-loss
mechanism in normal (i.e., non-Mira) K--M giants. Methods: Aldebaran was
observed between 2.28 and 2.31 micron with a projected baseline length of 10.4m
and a spectral resolution of 12000. Results: The uniform-disk diameter observed
in the CO first overtone lines is 20--35% larger than is measured in the
continuum. We have also detected a signature of inhomogeneities in the
CO-line-forming region on a spatial scale of ~45 mas, which is more than twice
as large as the angular diameter of the star itself. While the MARCS
photospheric model reproduces the observed spectrum well, the angular size in
the CO lines predicted by the MARCS model is significantly smaller than
observed. This is because the MARCS model with the parameters of Aldebaran has
a geometrical extension of only ~2% (with respect to the stellar radius). The
observed spectrum and interferometric data in the CO lines can be
simultaneously reproduced by placing an additional CO layer above the MARCS
photosphere. This CO layer is extended to 2.5 +/- 0.3 stellar radii with CO
column densities of 5x10^{19}--2x10^{20} cm^-2 and a temperature of 1500 +/-
200 K. Conclusions: The high spectral resolution of AMBER has enabled us to
spatially resolve the inhomogeneous, extended outer atmosphere (MOLsphere) in
the individual CO lines for the first time in a K giant. Our modeling of the
MOLsphere of Aldebaran suggests a rather small gradient in the temperature
distribution above the photosphere up to 2--3 stellar radii.


title:
Experimental Methods for Generating Two-Dimensional Quantum Turbulence
  in Bose-Einstein Condensates

abstract:
  Bose-Einstein condensates of dilute gases are well-suited for investigations
of vortex dynamics and turbulence in quantum fluids, yet there has been little
experimental research into the approaches that may be most promising for
generating states of two-dimensional turbulence in these systems. Here we give
an overview of techniques for generating the large and disordered vortex
distributions associated with two-dimensional quantum turbulence. We focus on
describing methods explored in our Bose-Einstein condensation laboratory, and
discuss the suitability of these methods for studying various aspects of
two-dimensional quantum turbulence. We also summarize some of the open
questions regarding our own understanding of these mechanisms of
two-dimensional quantum turbulence generation in condensates. We find that
while these disordered distributions of vortices can be generated by a variety
of techniques, further investigation is needed to identify methods for
obtaining quasi-steady-state quantum turbulence in condensates.


title: Stability of Periodic Traveling Waves for Nonlinear Dispersive Equations

abstract:
  We consider the stability and instability of periodic travling waves for
Korteweg-de Vries type equations with fractional dispersion and other nonlinear
dispersive equations. We establish that a constrained minimizer for the related
variational problem is nonlinearly stable to period preserving perturbations.
We also discuss when the associated linearized equation admits exponentially
growing solutions. The proof utilizes the variational structure of the
equation.


title: Dynamics of Chromospheric Upflows and Underlying Magnetic Fields

abstract:
  We used \ha-0.1 nm and magnetic field (at 1.56$\mu$) data obtained with the
New Solar Telescope to study the origin of the disk counterparts to type II
spicules, so-called rapid blueshifted excursions (RBEs). The high time cadence
of our chromospheric (10 s) and magnetic field (45 s) data allowed us to
generate x-t plots using slits parallel to the spines of the RBEs. These plots,
along with potential field extrapolation, led us to suggest that the occurrence
of RBEs is generally correlated with the appearance of new, mixed or unipolar
fields in close proximity to network fields. RBEs show a tendency to occur at
the interface between large-scale fields and small-scale dynamic magnetic loops
and thus are likely to be associated with existence of a magnetic canopy.
Detection of kinked and/or inverse "Y" shaped RBEs further confirm this
conclusion.


title: Object Oriented Data Analysis of Cell-Well Structured Data

abstract:
  Object oriented data analysis (OODA) aims at statistically analyzing
populations of complicated objects. This paper is motivated by a study of cell
images in cell culture biology, which highlights a common critical issue:
choice of data objects. Instead of conventionally treating either the
individual cells or the wells (a container in which the cells are grown) as
data objects, a new type of data object is proposed, that is the union of a
well with its corresponding set of cells. This paper contains two parts. The
first part is the image data analysis, which suggests empirically that the
cell-well unions can be a better choice of data objects than the cells or the
wells alone. The second part discusses the benefit of choosing cell-well unions
as data objects using an illustrative example and simulations. This research
suggests that OODA is not simply a frame work for understanding the structure
of the data analysis. It leads to useful interdisciplinary discussion that
gives better results through more appropriate choice of data objects,
especially for complex data analyses.


title: <3D> NLTE line formation in the atmospheres of red supergiants

abstract:
  Red supergiants with their enormous brightness at J-band are ideal probes of
cosmic chemical composition. It is therefore crucial to have realistic models
of radiative transfer in their atmospheres, which will permit determination of
abundances accurate to 0.15 dex, the precision attainable with future telescope
facilities in galaxies as distant as tens of Mpc. Here, we study the effects of
non-local thermodynamic equilibrium (NLTE) on the formation of iron, titanium,
and silicon lines, which dominate J-band spectra of red supergiants. It is
shown that the NLTE radiative transfer models enable accurate derivation of
metallicity and effective temperature in the J-band. We also discuss
consequences for RSG spectrum synthesis in different spectral windows,
including the heavily TiO-blanketed optical region, and atmospheric structure.
We then touch upon challenges of NLTE integration with new generation of 3D
hydrodynamical RSG models and present the first calculations of NLTE spectra
with the mean 3D model of Betelgeuse.


title: Generalization of Weak Amenability of Banach Algebras

abstract:
  New notion of weak amenability, $(\varphi,\psi)$-weak amenability recently
introduced. In this paper we consider this new notion and study
$(\varphi,\psi)$-weak amenability of group algebras $M(G)$, $L^1(G)$ and
$S^1(G)$.


title: Zeros of the partition function and phase transition

abstract:
  The equation of state of a system at equilibrium may be derived from the
canonical or the grand canonical partition function. The former is a function
of temperature T, while the latter also depends on the chemical potential \mu
for diffusive equilibrium. In the literature, often the variables
\beta=(k_BT)^{-1} and fugacity z=exp(\beta \mu) are used instead. For real
\beta and z, the partition functions are always positive, being sums of
positive terms. Following Lee, Yang and Fisher, we point out that valuable
information about the system may be gleaned by examining the zeros of the grand
partition function in the complex z plane (real \beta), or of the canonical
partition function in the complex \beta plane. In case there is a phase
transition, these zeros close in on the real axis in the thermodynamic limit.
Examples are given from the van der Waal gas, and from the ideal Bose gas,
where we show that even for a finite system with a small number of particles,
the method is useful.


title:
Delay and Delay Variation Constrained Algorithm based on VNS Algorithm
  for RP Management in Mobile IPv6

abstract:
  On account of the progress of network multimedia technology, more and more
real-time multimedia applications arrive with the need to transmit information
using multicast communication. These applications are more important with the
arrival of mobile IPv6 protocol through mobile receivers and sources. These
applications require a multicast routing protocol which has packets arriving at
multicast receptors within a specified QoS guaranteed and a quick recovery
mechanism. When multicasting with mobile IPv6, the mobility of a receivers and
senders may lead to serious problems. When the receiver or sender moves, the
quality of full multicast tree may degrade so that multicast datagrams cannot
be forwarded efficiently. D2V-RPM (delay and delay variation RP Manager)
problem consist in choosing an optimal multicast router in the network as the
root of the shared multicast tree (ST) within a specified delay and delay
variation bound for all multicast session, and recovering this RP if it's not
optimal or it has failed. This NP hard problem needs to be solved through a
heuristic algorithm. In this paper, we propose a new RP Management algorithm
based on Variable Neighborhood Search algorithm, based on a systematic
neighborhood changing. D2VVNS-RPM algorithm selects and recovers the RP router
by considering tree cost, delay and delay variation. Simulation results show
that good performance is achieved.


title: Anionic depolymerization transition in IrTe2

abstract:
  Selenium (Se) substitution drastically increases the transition temperature
of iridium ditelluride (IrTe$_{2}$) to a diamagnetic superstructure from 278 K
to 560 K. Transmission electron microscopy experiments revealed that this
enhancement is accompanied by the evolution of non-sinusoidal structure
modulations from $q = 1/5(10\bar{1})$- to $q = 1/6(10\bar{1})$-types. These
comprehensive results are consistent with the concept of the destabilization of
polymeric Te-Te bonds at the transition, the temperature of which is increased
by chemical and hydrostatic pressure and by the substitution of Te with the
more electronegative Se. This temperature-induced depolymerization transition
in IrTe$_{2}$ is unique in crystalline inorganic solids.


title: Crystallization in a sheared colloidal suspension

abstract:
  We study numerically the crystallization process in a supersaturated
suspension of repulsive colloidal particles driven by simple shear flow. The
effect of the shear flow on crystallization is two-fold: while it suppresses
the initial nucleation, once a large enough critical nucleus has formed its
growth is enhanced by the shear flow. Combining both effects implies an optimal
strain rate at which the overall crystallization rate has a maximum. To gain
insight into the underlying mechanisms, we employ a discrete state model
describing the transitions between the local structural configurations around
single particles. We observe a time-scale separation between these transitions
and the overall progress of the crystallization allowing for an effective
Markovian description. By using this model, we demonstrate that the suppression
of nucleation is due to the inhibition of a pre-structured liquid.


title: A critical review of RHIC experimental results

abstract:
  The relativistic heavy ion collider (RHIC) was constructed to achieve an
asymptotic state of nuclear matter in heavy ion collisions, a near-ideal gas of
deconfined quarks and gluons denoted quark-gluon plasma or QGP. RHIC collisions
are indeed very different from the hadronic processes observed at the Bevalac
and AGS, but high-energy elementary-collision mechanisms are also non-hadronic.
The two-component model (TCM) combines measured properties of elementary
collisions with the Glauber eikonal model to provide an alternative asymptotic
limit for A-A collisions. RHIC data have been interpreted to indicate formation
of a {\em strongly-coupled} QGP or "perfect liquid". In this review I consider
the experimental evidence that seems to support such conclusions and
alternative evidence that may conflict with those conclusions and suggest
different interpretations.


title:
Magnetic neutron diffraction study of Ba(Fe1-xCox)2As2 critical
  exponents through the tricritical doping

abstract:
  We present temperature dependent magnetic neutron diffraction measurements on
Ba(Fe$_{1-x}$Co$_{x}$)$_{2}$As$_{2}$ for $x$ = 0.039, 0.022, and 0.021 as-grown
single crystals. Our investigations probe the behavior near the magnetic
tricritical point in the ($x$,$T$) plane, $x_{tr} \approx $0.022, as well as
systematically exploring the character of the magnetic phase transition across
a range of doping values. All samples show long range antiferromagnetic order
that may be described near the transition by simple power laws, with $\beta$
=~0.306$\pm$0.060 for $x$ =~0.039, $\beta$ =~0.208$\pm$0.005 for $x$ =~0.022,
and $\beta$ =~0.198$\pm$0.009 for $x$ =~0.021. For the $x$ =~0.039 sample, the
data are reasonably well described by the order parameter exponent $\beta$
=~0.326 expected for a 3D Ising model while the $x$ =~0.022 and $x$ =~0.021
samples are near the $\beta$ =~0.25 value for a tricritical system in the
mean-field approximation. These results are discussed in the context of
existing experimental work and theoretical predictions.


title:
Exploiting Hybrid Channel Information for Downlink Multi-User MIMO
  Scheduling

abstract:
  We investigate the downlink multi-user MIMO (MU-MIMO) scheduling problem in
the presence of imperfect Channel State Information at the transmitter (CSIT)
that comprises of coarse and current CSIT as well as finer but delayed CSIT.
This scheduling problem is characterized by an intricate `exploitation -
exploration tradeoff' between scheduling the users based on current CSIT for
immediate gains, and scheduling them to obtain finer albeit delayed CSIT and
potentially larger future gains. We solve this scheduling problem by
formulating a frame based joint scheduling and feedback approach, where in each
frame a policy is obtained as the solution to a Markov Decision Process. We
prove that our proposed approach can be made arbitrarily close to the optimal
and then demonstrate its significant gains over conventional MU-MIMO
scheduling.


title: An equivariant Lefschetz fixed-point formula for correspondences

abstract:
  We compute the trace of an endomorphism in equivariant bivariant K-theory for
a compact group G in several ways: geometrically using geometric
correspondences, algebraically using localisation, and as a Hattori-Stallings
trace. This results in an equivariant version of the classical Lefschetz
fixed-point theorem, which applies to arbitrary equivariant correspondences,
not just maps.


title: Greedy Feature Selection for Subspace Clustering

abstract:
  Unions of subspaces provide a powerful generalization to linear subspace
models for collections of high-dimensional data. To learn a union of subspaces
from a collection of data, sets of signals in the collection that belong to the
same subspace must be identified in order to obtain accurate estimates of the
subspace structures present in the data. Recently, sparse recovery methods have
been shown to provide a provable and robust strategy for exact feature
selection (EFS)--recovering subsets of points from the ensemble that live in
the same subspace. In parallel with recent studies of EFS with L1-minimization,
in this paper, we develop sufficient conditions for EFS with a greedy method
for sparse signal recovery known as orthogonal matching pursuit (OMP).
Following our analysis, we provide an empirical study of feature selection
strategies for signals living on unions of subspaces and characterize the gap
between sparse recovery methods and nearest neighbor (NN)-based approaches. In
particular, we demonstrate that sparse recovery methods provide significant
advantages over NN methods and the gap between the two approaches is
particularly pronounced when the sampling of subspaces in the dataset is
sparse. Our results suggest that OMP may be employed to reliably recover exact
feature sets in a number of regimes where NN approaches fail to reveal the
subspace membership of points in the ensemble.


title: An Oka principle for equivariant isomorphisms

abstract:
  Let $G$ be a reductive complex Lie group acting holomorphically on normal
Stein spaces $X$ and $Y$, which are locally $G$-biholomorphic over a common
categorical quotient $Q$. When is there a global $G$-biholomorphism $X\to Y$?
  If the actions of $G$ on $X$ and $Y$ are what we, with justification, call
generic, we prove that the obstruction to solving this local-to-global problem
is topological and provide sufficient conditions for it to vanish. Our main
tool is the equivariant version of Grauert's Oka principle due to Heinzner and
Kutzschebauch.
  We prove that $X$ and $Y$ are $G$-biholomorphic if $X$ is $K$-contractible,
where $K$ is a maximal compact subgroup of $G$, or if $X$ and $Y$ are smooth
and there is a $G$-diffeomorphism $\psi:X\to Y$ over $Q$, which is holomorphic
when restricted to each fibre of the quotient map $X\to Q$. We prove a similar
theorem when $\psi$ is only a $G$-homeomorphism, but with an assumption about
its action on $G$-finite functions. When $G$ is abelian, we obtain stronger
theorems. Our results can be interpreted as instances of the Oka principle for
sections of the sheaf of $G$-biholomorphisms from $X$ to $Y$ over $Q$. This
sheaf can be badly singular, even for a low-dimensional representation of
$\mathrm{SL}_2(\C)$.
  Our work is in part motivated by the linearisation problem for actions on
$\C^n$. It follows from one of our main results that a holomorphic $G$-action
on $\C^n$, which is locally $G$-biholomorphic over a common quotient to a
generic linear action, is linearisable.


title: Vortex Wall Dynamics and Pinning in Helical Magnets

abstract:
  Domain walls formed by one dimensional array of vortex lines have been
recently predicted to exist in disordered helical magnets and multiferroics.
These systems are on one hand analogues to the vortex line lattices in type-II
superconductors while on the other hand they propagate in the magnetic medium
as a domain boundary. Using a long wavelength approach supported by numerical
optimization we lay out detailed theory for dynamics and structure of such
topological fluctuations at zero temperature in presence of weak disorder. We
show the interaction between vortex lines is weak. This is the direct
consequence of the screening of the vorticity by helical background in the
system. We explain how one can use this result to understand the elasticity of
the wall with a vicinal surface approach. Also we show the internal degree of
freedom of this array leads to the enhancement of its mobility. We present
estimates for the interaction and mobility enhancements using the microscopic
parameters of the system. Finally we determine the range of velocities/force
densities in which the internal movement of the vortex wall can be effective in
its dynamics.


title:
Experimental demonstration of broadband absorption enhancement in
  partially aperiodic silicon nanohole structures

abstract:
  We report the design, fabrication, and optical absorption measurement of
silicon membranes patterned with partially aperiodic nanohole structures. We
demonstrate excellent agreement between measurement and simulations. We
optimize a partially aperiodic structure using a random walk algorithm and
demonstrate an experimental broadband absorption of 4.9 times that of a
periodic array.


title: Multi-Layer Hybrid-ARQ for an Out-of-Band Relay Channel

abstract:
  This paper addresses robust communication on a fading relay channel in which
the relay is connected to the decoder via an out-of-band digital link of
limited capacity. Both the source-to-relay and the source-to-destination links
are subject to fading gains, which are generally unknown to the encoder prior
to transmission. To overcome this impairment, a hybrid automatic retransmission
request (HARQ) protocol is combined with multi-layer broadcast transmission,
thus allowing for variable-rate decoding. Moreover, motivated by cloud radio
access network applications, the relay operation is limited to
compress-and-forward. The aim is maximizing the throughput performance as
measured by the average number of successfully received bits per channel use,
under either long-term static channel (LTSC) or short-term static channel
(STSC) models. In order to opportunistically leverage better channel states
based on the HARQ feedback from the decoder, an adaptive compression strategy
at the relay is also proposed. Numerical results confirm the effectiveness of
the proposed strategies.


title:
Hyperbolicity of Physical Theories with Application to General
  Relativity

abstract:
  We consider gauge theories from the free evolution point of view, in which
initial data satisfying constraints of a theory are given. Because the
constraints are compatible with the field equations they remain so. We study a
model constrained Hamiltonian theory and identify a particular structure in the
equations of motion which we call the standard gauge freedom. The pure gauge
subsystem of this model theory is identified and the manner in which the gauge
variables couple to the field equations is presented. We demonstrate that the
set of gauge choices that can be coupled to the field equations to obtain a,
properly defined, wave-like formulation is exactly the set of wave-like pure
gauges. Consequently we analyze a parametrized family of formulations of
general relativity. The generalization of the harmonic gauge formulation to a
five parameter family of gauge conditions is obtained.


title:
Computational and Experimental Study of the Mechanics of Embryonic Wound
  Healing

abstract:
  Wounds in the embryo show a remarkable ability to heal quickly without
leaving a scar. Previous studies have found that an actomyosin ring ("purse
string") forms around the wound perimeter and contracts to close the wound over
the course of several dozens of minutes. Here, we report experiments that
reveal an even faster mechanism which remarkably closes wounds by more than 50%
within the first 30 seconds. Circular and elliptical wounds (~100 um in size)
were made in the blastoderm of early chick embryos and allowed to heal, with
wound area and shape characterized as functions of time. The closure rate
displayed a biphasic behavior, with rapid constriction lasting about a minute,
followed by a period of more gradual closure to complete healing. Fluorescent
staining suggests that both healing phases are driven by actomyosin
contraction, with relatively rapid contraction of fibers at cell borders within
a relatively thick ring of tissue (several cells wide) around the wound
followed by slower contraction of a thin supracellular actomyosin ring along
the margin, consistent with a purse string mechanism. Finite-element modeling
showed that this idea is biophysically plausible, with relatively isotropic
contraction within the thick ring giving way to tangential contraction in the
thin ring. In addition, consistent with experimental results, simulated
elliptical wounds heal with little change in aspect ratio, and decreased
membrane tension can cause these wounds to open briefly before going on to
heal. These results provide new insight into the healing mechanism in embryonic
epithelia.


title:
M\"obius Transformation and Einsten Velocity Addition in the Hyperbolic
  Geometry of Bolyai and Lobachevsky

abstract:
  In this chapter, dedicated to the 60th Anniversary of Themistocles M.
Rassias, M\"obius transformation and Einstein velocity addition meet in the
hyperbolic geometry of Bolyai and Lobachevsky. It turns out that M\"obius
addition that is extracted from M\"obius transformation of the complex disc and
Einstein addition from his special theory of relativity are isomorphic in the
sense of gyrovector spaces.


title: Large-Angle CMB Suppression and Polarization Predictions

abstract:
  The anomalous lack of large angle temperature correlations has been a
surprising feature of the cosmic microwave background (CMB) since first
observed by COBE-DMR and subsequently confirmed and strengthened by the
Wilkinson Microwave Anisotropy Probe. This anomaly may point to the need for
modifications of the standard model of cosmology or may indicate that our
Universe is a rare statistical fluctuation within that model. Further
observations of the temperature auto-correlation function will not elucidate
the issue; sufficiently high precision statistical observations already exist.
Instead, alternative probes are required. In this work we explore the
expectations for forthcoming polarization observations. We define a
prescription to test the hypothesis that the large-angle CMB temperature
perturbations in our Universe represent a rare statistical fluctuation within
the standard cosmological model. These tests are based on the temperature-$Q$
Stokes parameter correlation. Unfortunately these tests cannot be expected to
be definitive. However, we do show that if this $TQ$-correlation is observed to
be sufficiently large over an appropriately chosen angular range, then the
hypothesis can be rejected at a high confidence level. We quantify these
statements and optimize the statistics we have constructed to apply to the
anticipated polarization data. We find that we can construct a statistic that
has a 25 per cent chance of excluding the hypothesis that we live in a rare
realization of LCDM at the 99.9 per cent confidence level.


title: Warkworth 12-m VLBI Station: WARK12M - 2012

abstract:
  The Warkworth 12-m Radio Telescope is operated by the Institute for Radio
Astronomy and Space Research (IRASR) at AUT University, Auckland, New Zealand.
This report briefly reviews the characteristics of the 12-m VLBI station. We
report on a number of activities and technical developments.


title:
Business information through Spain's Chambers of Commerce: meeting
  business needs

abstract:
  From different public and private instances, mechanisms have been set in
action that allow for companies to obtain information in order to make
decisions with a stronger foundation. This article is focused on the
description of an entire information system for the business world, developed
in the realm of the Chambers of Commerce of Spain, which have given rise to the
creation of an authentic network of inter-chamber information.
  In Spain, the obligatory membership of businesses to the Chambers of Commerce
in their geographic areas, and therefore the compulsory payment of member
quotas, has traditionally generated some polemics, above all because many firms
have not perceived a material usefulness of the services offered by these
Chambers.
  Notwithstanding, the 85 Chambers currently existing in Spain, as well as the
organism that coordinates them -the Upper Council or Consejo Superior de
Camaras de Comercio- and the company created expressly to commercialize
informational services online, Camerdata, have developed genuinely informative
tools that cover a good part of the informational demands that a business might
claim, described here.


title: Upscaling of Nonlinear Forchheimer Flows

abstract:
  In this work we propose upscaling method for nonlinear Forchheimer flow in
highly heterogeneous porous media. The generalized Forchheimer law is
considered for incompressible and slightly-compressible single-phase flows. We
use recently developed analytical results Aulisa et al. (2009) and write the
resulting system in terms of a degenerate nonlinear flow equation for the
pressure with the nonlinearity that depends on the pressure gradient. The
coarse scale parameters for the steady state problem are determined so that the
volumetric average of velocity of the flow in the domain on fine scale and on
coarse scale are close enough. A flow-based coarsening approach is used, where
the equivalent permeability tensor is first evaluated following the streamline
of the existing linear cases, and successively modified in order to take into
account the nonlinear effects. Compared to previous works Durlofsky and
Karimi-Fard (2009) and Peszynska et al. (2009), our approach relies on recent
analytical results of Aulisa et al. (2009) and combines it with rigorous
mathematical upscaling theory for monotone operators. The developed upscaling
algorithm for nonlinear steady state problems is effectively used for variety
of heterogeneities in the domain of computation. Direct numerical computations
for average velocity and productivity index justify the usage of the coarse
scale parameters obtained for the special steady state case in the fully
transient problem. Analytical upscaling formulas in stratified domain are
obtained for the nonlinear case. They correlate with high accuracy with
numerical results.


title: Neutrino Oscillations: Hierarchy Question

abstract:
  The only experimentally observed phenomenon that lies outside the standard
model of the electroweak interaction is neutrino oscillations. A way to try to
unify the extensive neutrino oscillation data is to add a phenomenological mass
term to the Lagrangian that is not diagonal in the flavor basis. The goal is
then to understand the world's data in terms of the parameters of the mixing
matrix and the differences between the squares of the masses of the neutrinos.
An outstanding question is what is the correct ordering of the masses, the
hierarchy question. We point out a broken symmetry relevant to this question,
the symmetry of the simultaneous interchange of hierarchy and the sign of
$\theta_{13}$. We first present the results of an analysis of data that well
determine the phenomenological parameters but are not sensitive to the
hierarchy. We find $\theta_{13} = 0.152\pm 0.014$, $\theta_{23} =
0.25^{+0.03}_{-0.05} \pi$ and $\Delta_{32} = 2.45\pm 0.14 \times 10^{-3}$
eV$^2$, results consistent with others. We then include data that are sensitive
to the hierarchy and the sign of $\theta_{13}$. We find, unlike others, four
isolated minimum in the $\chi^2$-space as predicted by the symmetry. Now that
Daya Bay and RENO have determined $\theta_{13}$ to be surprisingly large, the
Super-K atmospheric data produce meaningful symmetry breaking such that the
inverse hierarchy is preferred at the 97.2 % level.


title:
The instability of orientifolds and the end of the (string) landscape as
  we know it

abstract:
  Negative mass brane-like objects known as orientifolds are crucial in the
construction of all presently understood realistic string compactifications and
I review in general the link between negative energy objects and the existence
of a landscape of metastable vacua. While in string perturbation theory these
solutions are non-dynamical, and hence avoid the usual instabilities of
negative tension objects, beyond perturbation theory it is well known that one
may lift orientifolds in M-theory to solutions well described by classical
general relativity and which consequently may be distorted in a variety of
ways. I review the failure of the usual positive energy theorems, as well as
several supersymmetric stability arguments, in this context and demonstrate
that one may smoothly distort the lifted orientifold, preserving the boundary
conditions, into solutions of lower energy. I present significant (numerical)
evidence that solutions with arbitrarily negative energy may be found among
these distorted orientifolds. Consequently, I suggest that this instability is
a fatal one and hence there is little reason to believe in the existence of a
string theory landscape. I briefly comment on the implications for Type I
string theory and string dualities.


title:
Lp-Nuclearity, traces, and Grothendieck-Lidskii formula on compact Lie
  groups

abstract:
  Given a compact Lie group $G$, in this paper we give symbolic criteria for
operators to be nuclear and r-nuclear on Lp-spaces, with applications to
distribution of eigenvalues and trace formulae. Since criteria in terms of
kernels are often not effective in view of Carleman's example, in this paper we
adopt the symbolic point of view. The criteria here are given in terms of the
concept of matrix symbols defined on the non-commutative analogue of the phase
space $G\times\hat{G}$, where $\hat{G}$ is the unitary dual of $G$.