title:
Negotiating the Probabilistic Satisfaction of Temporal Logic Motion
  Specifications

abstract:
  We propose a human-supervised control synthesis method for a stochastic
Dubins vehicle such that the probability of satisfying a specification given as
a formula in a fragment of Probabilistic Computational Tree Logic (PCTL) over a
set of environmental properties is maximized. Under some mild assumptions, we
construct a finite approximation for the motion of the vehicle in the form of a
tree-structured Markov Decision Process (MDP). We introduce an efficient
algorithm, which exploits the tree structure of the MDP, for synthesizing a
control policy that maximizes the probability of satisfaction. For the proposed
PCTL fragment, we define the specification update rules that guarantee the
increase (or decrease) of the satisfaction probability. We introduce an
incremental algorithm for synthesizing an updated MDP control policy that
reuses the initial solution. The initial specification can be updated, using
the rules, until the supervisor is satisfied with both the updated
specification and the corresponding satisfaction probability. We propose an
offline and an online application of this method.


title: Stable ample 2-vector bundles on Hirzebruch surfaces

abstract:
  We discuss stability conditions for all rank-2 ample vector bundles on
Hirzebruch surfaces with the second Chern class less than 7.


title: Nodal geometry of graphs on surfaces

abstract:
  We prove two mixed versions of the Discrete Nodal Theorem of Davies et. al.
[3] for bounded degree graphs, and for three-connected graphs of fixed genus
$g$. Using this we can show that for a three-connected graph satisfying a
certain volume-growth condition, the multiplicity of the $n$th Laplacian
eigenvalue is at most $2\left[
  6(n-1) + 15(2g-2) \right]^2$. Our results hold for any Schr\"odinger
operator, not just the Laplacian.


title: Minimum Distance Estimation for Robust High-Dimensional Regression

abstract:
  We propose a minimum distance estimation method for robust regression in
sparse high-dimensional settings. The traditional likelihood-based estimators
lack resilience against outliers, a critical issue when dealing with
high-dimensional noisy data. Our method, Minimum Distance Lasso (MD-Lasso),
combines minimum distance functionals, customarily used in nonparametric
estimation for their robustness, with l1-regularization for high-dimensional
regression. The geometry of MD-Lasso is key to its consistency and robustness.
The estimator is governed by a scaling parameter that caps the influence of
outliers: the loss per observation is locally convex and close to quadratic for
small squared residuals, and flattens for squared residuals larger than the
scaling parameter. As the parameter approaches infinity, the estimator becomes
equivalent to least-squares Lasso. MD-Lasso enjoys fast convergence rates under
mild conditions on the model error distribution, which hold for any of the
solutions in a convexity region around the true parameter and in certain cases
for every solution. Remarkably, a first-order optimization method is able to
produce iterates very close to the consistent solutions, with geometric
convergence and regardless of the initialization. A connection is established
with re-weighted least-squares that intuitively explains MD-Lasso robustness.
The merits of our method are demonstrated through simulation and eQTL data
analysis.


title:
Evidence for Maximal Acceleration and Singularity Resolution in
  Covariant Loop Quantum Gravity

abstract:
  A simple argument indicates that covariant loop gravity (spinfoam theory)
predicts a maximal acceleration, and hence forbids the development of curvature
singularities. This supports the results obtained for cosmology and black holes
using canonical methods.


title:
Construction of Recurrent Fractal Interpolation Surfaces with Function
  Scaling Factors and Estimation of Box-counting Dimension on Rectangular Grids

abstract:
  We consider a construction of recurrent fractal interpolation surfaces with
function vertical scaling factors and estimation of their box-counting
dimension. A recurrent fractal interpolation surface (RFIS) is an attractor of
a recurrent iterated function system (RIFS) which is a graph of bivariate
interpolation function. For any given data set on rectangular grids, we
construct general recurrent iterated function systems with function vertical
scaling factors and prove the existence of bivariate functions whose graph are
attractors of the above constructed RIFSs. Finally, we estimate lower and upper
bounds for the box-counting dimension of the constructed RFISs.


title:
Dynamics of the dust rings and satellites of Uranus and of the Saturn's
  F-ring

abstract:
  The $\mu$ and $\nu$ rings of Uranus form a secondary ring-moon system with
the satellites Puck, Mab,Portia, and Rosalind. These rings are tenuous and
dominated by micrometric particles, which can be strongly disturbed by the
solar radiation pressure. We performed a numerical analysis of the orbital
evolution of a sample of particles under the influence of the solar radiation
force and the planetary oblateness, combined with the gravitational interaction
with the close satellites. The most likely result is a collisions and the
deposition of particles onto the surface of these satellites. Since this
mechanism tends to cause a depletion of material of the rings, we investigate
additional sources for these dust particles. Adopting a rough estimative of the
flux of interplanetary meteoroids, we found that the ejections from Mab could
generate a ring with optical depth comparable with the observations.
  A similar analysis was carried out for the F-ring dust band. The damping due
to the Saturn's oblateness prevents the overstated changes of the eccentricity
and increases in the lifetime of the particles. Therewithal photometric study
of the F-ring using Cassini images revealed that substantial secular increase
in the brightness of Saturn's F ring has occurred in the last 25 years. The
shapes of the phase curves from Cassini and Voyager are similar, suggesting
that although the number of dust particles has increased, the overall
distribution of sizes is unchanged.
  The dust bands that permeate the rings of Uranus were observed late in 2007
during the equinox, when the Sun crossed the ring plane. Images taken with the
VLT were processed and then combined to result in long-exposure frames. For
each frame, the north and south radial profiles were extracted. They will be
used to develop a photometric model.


title: Certification of Bounds of Non-linear Functions: the Templates Method

abstract:
  The aim of this work is to certify lower bounds for real-valued multivariate
functions, defined by semialgebraic or transcendental expressions. The
certificate must be, eventually, formally provable in a proof system such as
Coq. The application range for such a tool is widespread; for instance Hales'
proof of Kepler's conjecture yields thousands of inequalities. We introduce an
approximation algorithm, which combines ideas of the max-plus basis method (in
optimal control) and of the linear templates method developed by Manna et al.
(in static analysis). This algorithm consists in bounding some of the
constituents of the function by suprema of quadratic forms with a well chosen
curvature. This leads to semialgebraic optimization problems, solved by
sum-of-squares relaxations. Templates limit the blow up of these relaxations at
the price of coarsening the approximation. We illustrate the efficiency of our
framework with various examples from the literature and discuss the interfacing
with Coq.


title:
Small sets of locally indistinguishable orthogonal maximally entangled
  states

abstract:
  We study the problem of distinguishing quantum states using local operations
and classical communication (LOCC). A question of fundamental interest is
whether there exist sets of $k \leq d$ orthogonal maximally entangled states in
$\mathbb{C}^{d}\otimes\mathbb{C}^{d}$ that are not perfectly distinguishable by
LOCC. A recent result by Yu, Duan, and Ying [Phys. Rev. Lett. 109 020506 (2012)
-- arXiv:1107.3224 [quant-ph]] gives an affirmative answer for the case $k =
d$. We give, for the first time, a proof that such sets of states indeed exist
even in the case $k < d$. Our result is constructive and holds for an even
wider class of operations known as positive-partial-transpose measurements
(PPT). The proof uses the characterization of the PPT-distinguishability
problem as a semidefinite program.


title: 6-Vertex Model on an Open String Worldsheet

abstract:
  We propose boundary conditions on a two dimensional 6-vertex model, which is
defined on the lightcone lattice for an open string worldsheet. We show that,
in the continuum limit, the degrees of freedom of this 6-vertex model describe
a target space coordinate compactified on a circle of radius R, which is
related to the vertex weights. This conclusion had already been established for
the case of a 6-vertex model on the worldsheet lattice for the propagator of a
closed string. This exercise illustrates how the Bethe ansatz works in the
presence of boundaries, at least of this particular type.


title: Chiral conductivities and effective field theory

abstract:
  We construct the three-dimensional effective field theory which reproduces
low-momentum static correlation functions in four-dimensional quantum field
theories with U(1) axial anomalies and a dynamical vector gauge field, in
thermal equilibrium. We compute radiative corrections to parity-violating
chiral conductivities, to leading order in the effective theory. All of the
anomaly-induced transport is susceptible to radiative corrections, except for
certain two-point functions which are required by symmetry to vanish.


title:
The sign rule and beyond: Boundary effects, flexibility, and noise
  correlations in neural population codes

abstract:
  Over repeat presentations of the same stimulus, sensory neurons show variable
responses. This "noise" is typically correlated between pairs of cells, and a
question with rich history in neuroscience is how these noise correlations
impact the population's ability to encode the stimulus. Here, we consider a
very general setting for population coding, investigating how information
varies as a function of noise correlations, with all other aspects of the
problem - neural tuning curves, etc. - held fixed. This work yields unifying
insights into the role of noise correlations. These are summarized in the form
of theorems, and illustrated with numerical examples involving neurons with
diverse tuning curves. Our main contributions are as follows.
  (1) We generalize previous results to prove a sign rule (SR) - if noise
correlations between pairs of neurons have opposite signs vs. their signal
correlations, then coding performance will improve compared to the independent
case. This holds for three different metrics of coding performance, and for
arbitrary tuning curves and levels of heterogeneity. This generality is true
for our other results as well.
  (2) As also pointed out in the literature, the SR does not provide a
necessary condition for good coding. We show that a diverse set of correlation
structures can improve coding. Many of these violate the SR, as do
experimentally observed correlations. There is structure to this diversity: we
prove that the optimal correlation structures must lie on boundaries of the
possible set of noise correlations.
  (3) We provide a novel set of necessary and sufficient conditions, under
which the coding performance (in the presence of noise) will be as good as it
would be if there were no noise present at all.


title:
Internal composite bound states in deterministic reaction diffusion
  models

abstract:
  By identifying potential composite states that occur in the
Sel'kov-Gray-Scott (GS) model, we show that it can be considered as an
effective theory at large spatio-temporal scales, arising from a more
\textit{fundamental} theory (which treats these composite states as fundamental
chemical species obeying the diffusion equation) relevant at shorter
spatio-temporal scales. When simulations in the latter model are performed as a
function of a parameter $M = \lambda^{-1}$, the generated spatial patterns
evolve at late times into those of the GS model at large $M$, implying that the
composites follow their own unique dynamics at short scales. This separation of
scales is an example of \textit{dynamical} decoupling in reaction diffusion
systems.


title:
Long-range angular correlations of $\rm \pi$, K and p in p-Pb collisions
  at $\sqrt{s_{\rm NN}}$ = 5.02 TeV

abstract:
  Angular correlations between unidentified charged trigger particles and
various species of charged associated particles (unidentified particles, pions,
kaons, protons and antiprotons) are measured by the ALICE detector in p-Pb
collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV in the
transverse-momentum range $0.3 < p_{\rm T} < 4$ GeV/$c$. The correlations
expressed as associated yield per trigger particle are obtained in the
pseudorapidity range $|\eta_{\rm lab}|<0.8$. Fourier coefficients are extracted
from the long-range correlations projected onto the azimuthal angle difference
and studied as a function of $p_{\rm T}$ and in intervals of event
multiplicity. In high-multiplicity events, the second-order coefficient for
protons, $v_2^p$, is observed to be smaller than that for pions, $v_2^\pi$, up
to about $p_{\rm T} = 2$ GeV/$c$. To reduce correlations due to jets, the
per-trigger yield measured in low-multiplicity events is subtracted from that
in high-multiplicity events. A two-ridge structure is obtained for all particle
species. The Fourier decomposition of this structure shows that the
second-order coefficients for pions and kaons are similar. The $v_2^p$ is found
to be smaller at low $p_{\rm T}$ and larger at higher $p_{\rm T}$ than
$v_2^pi$, with a crossing occurring at about 2 GeV. This is qualitatively
similar to the elliptic-flow pattern observed in heavy-ion collisions. A mass
ordering effect at low transverse momenta is consistent with expectations from
hydrodynamic model calculations assuming a collectively expanding system.


title: Enhanced flow of core-softened fluids through nanotubes

abstract:
  We investigate through non-equilibrium molecular dynamic simulations the flow
of core-softened fluids inside nanotubes. Our results reveal a anomalous
increase of the overall mass flux for nanotubes with sufficiently smaller
radii. This is explained in terms of a transition from a single-file type of
flow to the movement of an ordered-like fluid as the nanotube radius increases.
The occurrence of a global minimum in the mass flux at this transition reflects
the competition between the two characteristics length scales of the
core-softened potential. Moreover, by increasing further the radius, another
substantial change in the flow behavior, which becomes more evident at low
temperatures, leads to a local minimum in the overall mass flux.
Microscopically, this second transition results from the formation of a
double-layer of flowing particles in the confined nanotube space. These special
nano-fluidic features of core-softened particles closely resemble the enhanced
flow behavior observed for liquid water inside carbon nanotubes.


title:
The Deep Blue Color of HD189733b: Albedo Measurements with Hubble Space
  Telescope/Space Telescope Imaging Spectrograph at Visible Wavelengths

abstract:
  We present a secondary eclipse observation for the hot Jupiter HD189733b
across the wavelength range 290-570nm made using the Space Telescope Imaging
Spectrograph on the Hubble Space Telescope. We measure geometric albedos of Ag
= 0.40 \pm 0.12 across 290-450nm and Ag < 0.12 across 450-570nm at 1-sigma
confidence. The albedo decrease toward longer wavelengths is also apparent when
using six wavelength bins over the same wavelength range. This can be
interpreted as evidence for optically thick reflective clouds on the dayside
hemisphere with sodium absorption suppressing the scattered light signal beyond
~450nm. Our best-fit albedo values imply that HD189733b would appear a deep
blue color at visible wavelengths.


title:
Axionic superconductivity in three dimensional doped narrow gap
  semiconductors

abstract:
  We consider the competition between the conventional s-wave and the triplet
Balian-Werthamer or the B-phase pairings in the doped three dimensional narrow
gap semiconductors, such as $\mathrm{Cu}_x\mathrm{Bi}_2\mathrm{Se}_3$ and
$\mathrm{Sn}_{1-x}\mathrm{In}_x\mathrm{Te}$. When the coupling constants of the
two contending channels are comparable, we find a simultaneously time-reversal
and parity violating $p + is$ state at low temperatures, which provides an
example of dynamic axionic state of matter. In contradistinction to the
time-reversal invariant, topological B-phase, the $p + is$ state possesses
gapped Majorana fermions as the surface Andreev bound states, which give rise
to an anomalous surface thermal Hall effect. The anomalous gravitational and
electrodynamic responses of the $p+is$ state can be described by the $\theta$
vacuum structure, where $\theta \neq 0$ or $\pi$.

categories: cond-mat.supr-con cond-mat.mes-hall cond-mat.str-el hep-th quant-ph


title: Integrated Circuit Design in US High-Energy Physics

abstract:
  This whitepaper summarizes the status, plans, and challenges in the area of
integrated circuit design in the United States for future High Energy Physics
(HEP) experiments. It has been submitted to CPAD (Coordinating Panel for
Advanced Detectors) and the HEP Community Summer Study 2013(Snowmass on the
Mississippi) held in Minnesota July 29 to August 6, 2013. A workshop titled: US
Workshop on IC Design for High Energy Physics, HEPIC2013 was held May 30 to
June 1, 2013 at Lawrence Berkeley National Laboratory (LBNL). A draft of the
whitepaper was distributed to the attendees before the workshop, the content
was discussed at the meeting, and this document is the resulting final product.
The scope of the whitepaper includes the following topics: Needs for IC
technologies to enable future experiments in the three HEP frontiers Energy,
Cosmic and Intensity Frontiers; Challenges in the different technology and
circuit design areas and the related R&D needs; Motivation for using different
fabrication technologies; Outlook of future technologies including 2.5D and 3D;
Survey of ICs used in current experiments and ICs targeted for approved or
proposed experiments; IC design at US institutes and recommendations for
collaboration in the future.


title:
Preserving the Q-Factors of ZnO Nanoresonators via Polar Surface
  Reconstruction

abstract:
  We perform molecular dynamics simulations to investigate the effect of polar
surfaces on the quality (Q)-factors of zinc oxide (ZnO) nanowire-based
nanoresonators. We find that the Q-factors in ZnO nanoresonators with free
polar (0001) surfaces is about one order of magnitude higher than in
nanoresonators that have been stabilized with reduced charges on the polar
(0001) surfaces. From normal mode analysis, we show that the higher Q-factor is
due to a shell-like reconstruction that occurs for the free polar surfaces.
This shell-like reconstruction suppresses twisting motion in the nanowires such
that the mixing of other modes with the resonant mode of oscillation is
minimized, and leads to substantially higher Q-factors in the ZnO
nanoresonators with free polar surfaces.


title: On the Lie structure of a prime associative superalgebra

abstract:
  In this paper some results on the Lie structure of prime superalgebras are
discussed. We prove that, with the exception of some special cases, for a prime
superalgebra, $A$, over a ring of scalars $\Phi$ with $1/2\in \Phi$, if $L$ is
a Lie ideal of $A$ and $W$ is a subalgebra of $A$ such that $[W, L]\subseteq
W$, then either $L\subseteq Z$ or $W\subseteq Z$. Likewise, if $V$ is a
submodule of $A$ and $[V, L]\subseteq V$, then either $V\subseteq Z$ or
$L\subseteq Z$ or there exists an ideal of $A$, $M$, such that $0\not=
[M,A]\subseteq V$. This work extends to prime superalgebras some results of I.
N. Herstein, C. Lanski and S. Montgomery on prime algebras.


title: Detection of the compressed primary stellar wind in eta Carinae

abstract:
  A series of three HST/STIS spectroscopic mappings, spaced approximately one
year apart, reveal three partial arcs in [Fe II] and [Ni II] emissions moving
outward from eta Carinae. We identify these arcs with the shell-like
structures, seen in the 3D hydrodynamical simulations, formed by compression of
the primary wind by the secondary wind during periastron passages.


title: Algebra of Majorana Doubling

abstract:
  Motivated by the problem of identifying Majorana mode operators at junctions,
we analyze a basic algebraic structure leading to a doubled spectrum. For
general (nonlinear) interactions the emergent mode creation operator is highly
non-linear in the original effective mode operators, and therefore also in the
underlying electron creation and destruction operators. This phenomenon could
open up new possibilities for controlled dynamical manipulation of the modes.
We briefly compare and contrast related issues in the Pfaffian quantum Hall
state.

categories: cond-mat.supr-con cond-mat.mes-hall hep-th quant-ph


title: The Spin of Supermassive Black Holes

abstract:
  Black hole spin is a quantity of great interest to both physicists and
astrophysicists. We review the current status of spin measurements in
supermassive black holes (SMBH). To date, every robust SMBH spin measurement
uses X-ray reflection spectroscopy, so we focus almost exclusively on this
technique as applied to moderately-luminous active galactic nuclei (AGN). After
describing the foundations and uncertainties of the method, we summarize the
current status of the field. At the time of writing, observations by
XMM-Newton, Suzaku and NuSTAR have given robust spin constraints on 22 SMBHs.
We find a significant number of rapidly-rotating SMBHs (with dimensionless spin
parameters a>0.9) although, especially at the higher masses (M>4*10^7Msun),
there are also some SMBHs with intermediate spin parameters. This may be giving
us our first hint at a mass-dependent spin distribution which would, in turn,
provide interesting constraints on models for SMBH growth. We also discuss the
recent discovery of relativistic X-ray reverberation which we can use to "echo
map" the innermost regions of the accretion disk. The ultimate development of
these reverberation techniques, when applied to data from future
high-throughput X-ray observatories such as LOFT, ATHENA+, and AXSIO, will
permit the measurement of black hole spin by a characterization of strong-field
Shapiro delays. We conclude with a brief discussion of other electromagnetic
methods that have been attempted or are being developed to constrain SMBH spin.


title:
Evidence for a correlation between the sizes of quiescent galaxies and
  local environment to z ~ 2

abstract:
  We present evidence for a strong relationship between galaxy size and
environment for the quiescent population in the redshift range 1 < z < 2.
Environments were measured using projected galaxy overdensities on a scale of
400 kpc, as determined from ~ 96,000 K-band selected galaxies from the UKIDSS
Ultra Deep Survey (UDS). Sizes were determined from ground-based K-band
imaging, calibrated using space-based CANDELS HST observations in the centre of
the UDS field, with photometric redshifts and stellar masses derived from
11-band photometric fitting. From the resulting size-mass relation, we confirm
that quiescent galaxies at a given stellar mass were typically ~ 50 % smaller
at z ~ 1.4 compared to the present day. At a given epoch, however, we find that
passive galaxies in denser environments are on average significantly larger at
a given stellar mass. The most massive quiescent galaxies (M_stellar > 2 x
10^11 M_sun) at z > 1 are typically 50 % larger in the highest density
environments compared to those in the lowest density environments. Using Monte
Carlo simulations, we reject the null hypothesis that the size-mass relation is
independent of environment at a significance > 4.8 sigma for the redshift range
1 < z < 2. In contrast, the evidence for a relationship between size and
environment is much weaker for star-forming galaxies.


title: What can we learn about the lepton CP phase in the next 10 years?

abstract:
  We discuss how the lepton CP phase can be constrained by accelerator and
reactor measurements in an era without dedicated experiments for CP violation
search. To characterize globally the sensitivity to the CP phase \delta_{CP},
we introduce a new measure, the CP exclusion fraction, which quantifies what
fraction of the \delta_{CP} space can be excluded at a given input values of
\theta_{23} and \delta_{CP}. Using the measure we study the CP sensitivity
which may be possessed by the accelerator experiments T2K and NOvA. We show
that, if the mass hierarchy is known, T2K and NOvA alone may exclude,
respectively, about 50%-60% and 40%-50% of the \delta_{CP} space at 90% CL by
10 years running, provided that a considerable fraction of beam time is devoted
to the antineutrino run. The synergy between T2K and NOvA is remarkable,
leading to the determination of the mass hierarchy through CP sensitivity at
the same CL.


title:
Threshold Resummed and Approximate NNLO results for W+W- Pair Production
  at the LHC

abstract:
  The next-to-leading order (NLO) QCD radiative corrections to W+W- production
at hadron colliders are well understood. We combine NLO perturbative QCD
calculations with soft-gluon resummation of threshold logarithms to find a
next-to-next-to leading logarithmic (NNLL) prediction for the total cross
section and the invariant mass distribution at the LHC. We also obtain
approximate next-to-next-to-leading order (NNLO) results for the total W+W-
cross section at the LHC which includes all contributions from the scale
dependent leading singular terms. Our result for the approximate NNLO total
cross section is the most precise theoretical prediction available.
Uncertainties due to scale variation are shown to be small when the threshold
logarithms are included. NNLL threshold resummation increases the W+W-
invariant mass distribution by ~ 3-4% in the peak region for both \sqrt{S}=8
and 14 TeV. The NNLL threshold resummed and approximate NNLO cross sections
increase the NLO cross section by 0.5-3% for \sqrt{S}=7, 8, 13, and 14 TeV.


title: A Late-Time Flattening of Light Curves in Gamma-Ray Burst Afterglows

abstract:
  The afterglow emission from Gamma-Ray Bursts (GRBs) is usually interpreted as
synchrotron radiation from relativistic electrons accelerated at the GRB
external shock, that decelerates from ultra-relativistic to non-relativistic
speeds as it sweeps up the surrounding medium. We investigate the temporal
decay of the emission from GRB afterglows at late times, when the bulk of the
shock-accelerated electrons are non-relativistic. For a uniform circumburst
medium, we show that such "deep Newtonian phase" begins at t_{DN} ~ 3
epsilon_{e,-1}^{5/6} t_{ST}, where t_{ST} marks the transition of the blast
wave to the non-relativistic spherically-symmetric Sedov-Taylor solution, and
epsilon_e = 0.1 epsilon_{e,-1} quantifies the amount of shock energy
transferred to the post-shock electrons. For typical parameters, the deep
Newtonian stage starts ~ 0.5-several years after the GRB. The radio flux in
this phase decays as F_nu ~ t^{-3(p+1)/10}, with decay slope between -0.9 and
-1.2, for a power-law distribution of shock-accelerated electrons with index 2
< p < 3. This is shallower than the commonly assumed scaling F_nu ~
t^{-3(5p-7)/10} (with decay slope between -0.9 and -2.4) derived by Frail et
al. (2000), which only applies if the GRB shock is non-relativistic, but the
electron distribution still peaks at ultra-relativistic energies (a regime that
is relevant for a narrow time interval, and only if t_{DN} > t_{ST}, or
epsilon_e > 0.03). We discuss how the deep Newtonian phase can be reliably used
for GRB calorimetry, and we comment on the good detection prospects of
trans-relativistic blast waves at 0.1-10 GHz with EVLA and LOFAR.


title: Anomaly Mediation from Unbroken Supergravity

abstract:
  When supergravity (SUGRA) is spontaneously broken, it is well known that
anomaly mediation generates sparticle soft masses proportional to the gravitino
mass. Recently, we showed that one-loop anomaly-mediated gaugino masses should
be associated with unbroken supersymmetry (SUSY). This counterintuitive result
arises because the underlying symmetry structure of (broken) SUGRA in flat
space is in fact (unbroken) SUSY in anti-de Sitter (AdS) space. When quantum
corrections are regulated in a way that preserves SUGRA, the underlying AdS
curvature (proportional to the gravitino mass) necessarily appears in the
regulated action, yielding soft masses without corresponding goldstino
couplings. In this paper, we extend our analysis of anomaly mediation to
sfermion soft masses. Already at tree-level we encounter a number of surprises,
including the fact that zero soft masses correspond to broken (AdS) SUSY. At
one-loop, we explain how anomaly mediation appears when regulating SUGRA in a
way that preserves super-Weyl invariance. We find that recent claims in the
literature about the non-existence of anomaly mediation were based on a
Wilsonian effective action with residual gauge dependence, and the
gauge-invariant 1PI effective action contains the expected anomaly-mediated
spectrum. Finally, we calculate the sfermion spectrum to all orders, and use
supertrace relations to derive the familiar two-loop soft masses from minimal
anomaly mediation, as well as unfamiliar tree-level and one-loop goldstino
couplings consistent with renormalization group invariance.


title: Dirty Weyl fermions: rare region effects near 3D Dirac points

abstract:
  We study three-dimensional Dirac fermions with weak finite-range scalar
potential disorder. We show that even though disorder is perturbatively
irrelevant at 3D Dirac points, nonperturbative effects from rare regions give
rise to a nonzero density of states and a finite mean free path, with the
transport at the Dirac point being dominated by hopping between rare regions.
As one moves in chemical potential away from the Dirac point, there are
interesting intermediate-energy regimes where the rare regions produce
scattering resonances that determine the DC conductivity. We also discuss the
interplay of disorder with interactions at the Dirac point. Attractive
interactions drive a transition into a granular superconductor, with a critical
temperature that depends strongly on the disorder distribution. In the presence
of Coulomb repulsion and weak retarded attraction, the system can be a Bose
glass. Our results apply to all 3D systems with Dirac points, including Weyl
semimetals, and overturn a thirty year old consensus regarding the irrelevance
of weak disorder at 3D Dirac points.

categories: cond-mat.str-el cond-mat.dis-nn cond-mat.mes-hall cond-mat.stat-mech


title:
The Hilbert-glass transition: new universality of temperature-tuned
  many-body dynamical quantum criticality

abstract:
  We consider a new class of unconventional critical phenomena that is
characterized by singularities only in dynamical quantities and has no
thermodynamic signatures. A possible example is the recently proposed many-body
localization transition, in which transport coefficients vanish at a critical
temperature. Describing this unconventional quantum criticality has been
technically challenging as understanding the finite-temperature dynamics
requires the knowledge of a large number of many-body eigenstates. Here we
develop a real-space renormalization group method for excited state (RSRG-X),
that allow us to overcome this challenge, and establish the existence and
universal properties of such temperature-tuned dynamical phase transitions. We
characterize a specific example: the 1D disordered transverse field Ising model
with interactions. Using RSRG-X, we find a finite-temperature transition,
between two localized phases, characterized by non-analyticities of the dynamic
spin correlation function and the low frequency heat conductivity.


title:
Time Delay and Accretion Disk Size Measurements in the Lensed Quasar SBS
  0909+532 from Multiwavelength Microlensing Analysis

abstract:
  We present three complete seasons and two half-seasons of SDSS r-band
photometry of the gravitationally lensed quasar SBS 0909+532 from the U.S.
Naval Observatory, as well as two seasons each of SDSS g-band and r-band
monitoring from the Liverpool Robotic Telescope. Using Monte Carlo simulations
to simultaneously measure the system's time delay and model the r-band
microlensing variability, we confirm and significantly refine the precision of
the system's time delay to \Delta t_{AB} = 50^{+2}_{-4} days, where the stated
uncertainties represent the bounds of the formal 1\sigma\ confidence interval.
There may be a conflict between the time delay measurement and a lens
consisting of a single galaxy. While models based on the Hubble Space Telescope
astrometry and a relatively compact stellar distribution can reproduce the
observed delay, the models have somewhat less dark matter than we would
typically expect. We also carry out a joint analysis of the microlensing
variability in the r- and g-bands to constrain the size of the quasar's
continuum source at these wavelengths, obtaining log[(r_{s,r}/cm)
[cos{i}/0.5]^{1/2}] = 15.3 \pm 0.3 and log[(r_{s,g}/cm) [cos{i}/0.5]^{1/2}] =
14.8 \pm 0.9, respectively. Our current results do not formally constrain the
temperature profile of the accretion disk but are consistent with the
expectations of standard thin disk theory.


title: SMBH accretion & mergers: removing the symmetries

abstract:
  We review recent progress in studying accretion flows on to supermassive
black holes (SMBH). Much of this removes earlier assumptions of symmetry and
regularity, such as aligned and prograde disc rotation. This allows a much
richer variety of effects, often because cancellation of angular momentum
allows rapid infall. Potential applications include lower SMBH spins allowing
faster mass growth and suppressing gravitational-wave reaction recoil in
mergers, gas-assisted SMBH mergers, and near-dynamical accretion in galaxy
centres.


title: Dynamical quantum phase transitions in random spin chains

abstract:
  Quantum systems can exhibit a great deal of universality at low temperature
due to the structure of ground states and the critical points separating
distinct states. On the other hand, quantum time evolution of the same systems
involves all energies and it is therefore thought to be much harder, if at all
possible, to have sharp transitions in the dynamics. In this paper we show that
phase transitions characterized by universal singularities do occur in the time
evolution of random spin chains. The sharpness of the transitions and integrity
of the phases owes to many-body localization, which prevents thermalization in
these systems. Using a renormalization group approach, we solve the time
evolution of random Ising spin chains with generic interactions starting from
initial states of arbitrary energy. As a function of the Hamiltonian
parameters, the system is tuned through a dynamical transition, similar to the
ground state critical point, at which the local spin correlations establish
true long range temporal order. In the state with dominant transverse field, a
spin that starts in an up state loses its orientation with time, while in the
"ordered" state it never does. As in ground state quantum phase transitions,
the dynamical transition has unique signatures in the entanglement properties
of the system. When the system is initialized in a product state the
entanglement entropy grows as $log(t)$ in the two "phases", while at the
critical point it grows as $log^\a(t)$, with $\a$ a universal number. This
universal entanglement growth requires generic ("integrability breaking")
interactions to be added to the pure transverse field Ising model.


title:
Ionization in atmospheres of Brown Dwarfs and extrasolar planets IV. The
  Effect of Cosmic Rays

abstract:
  Cosmic rays provide an important source for free electrons in the Earth's
atmosphere and also in dense interstellar regions where they produce a
prevailing background ionization. We utilize a Monte Carlo cosmic ray transport
model for particle energies of 1 MeV < E < 1 GeV, and an analytic cosmic ray
transport model for particle energies of 1 GeV < E < 1 TeV in order to
investigate the cosmic ray enhancement of free electrons in substellar
atmospheres of free-floating objects. The cosmic ray calculations are applied
to Drift-Phoenix model atmospheres of an example brown dwarf with effective
temperature Teff = 1500 K, and two example giant gas planets (Teff = 1000 K,
1500 K). For the model brown dwarf atmosphere, the electron fraction is
enhanced significantly by cosmic rays when the pressure pgas < 10^-2 bar. Our
example giant gas planet atmosphere suggests that the cosmic ray enhancement
extends to 10^-4 - 10^-2 bar, depending on the effective temperature. For the
model atmosphere of the example giant gas planet considered here (Teff = 1000
K), cosmic rays bring the degree of ionization to fe ~ 10^-8 when pgas < 10^-8
bar, suggesting that this part of the atmosphere may behave as a weakly ionized
plasma. Although cosmic rays enhance the degree of ionization by over three
orders of magnitude in the upper atmosphere, the effect is not likely to be
significant enough for sustained coupling of the magnetic field to the gas.


title: The Runaway Binary LP 400-22 is Leaving the Galaxy

abstract:
  We present optical spectroscopy, astrometry, radio, and X-ray observations of
the runaway binary LP 400-22. We refine the orbital parameters of the system
based on our new radial velocity observations. Our parallax data indicate that
LP 400-22 is significantly more distant (3 sigma lower limit of 840 pc) than
initially predicted. LP 400-22 has a tangential velocity in excess of 830 km/s;
it is unbound to the Galaxy. Our radio and X-ray observations fail to detect a
recycled millisecond pulsar companion, indicating that LP 400-22 is a double
white dwarf system. This essentially rules out a supernova runaway ejection
mechanism. Based on its orbit, a Galactic center origin is also unlikely.
However, its orbit intersects the locations of several globular clusters;
dynamical interactions between LP 400-22 and other binary stars or a central
black hole in a dense cluster could explain the origin of this unusual binary.


title: Maximal Displacement of Critical Branching Symmetric Stable Processes

abstract:
  We consider a critical continuous-time branching process (a Yule process) in
which the individuals independently execute symmetric $\alpha-$stable random
motions on the real line starting at their birth points. Because the branching
process is critical, it will eventually die out, and so there is a well-defined
maximal location $M$ ever visited by an individual particle of the process. We
prove that the distribution of $M$ satisfies the asymptotic relation $P\{M\geq
x \}\sim (2/\alpha)^{1/2}x^{-\alpha /2}$ as $x \rightarrow \infty$.


title:
Strong Hyperfine-Induced Modulation of an Optically-Driven Hole Spin in
  an InAs Quantum Dot

abstract:
  Compared to electrons, holes in InAs quantum dots have a significantly weaker
hyperfine interaction that leads to less dephasing from nuclear spins. Thus
many recent studies have suggested that nuclear spins are unimportant for hole
spin dynamics compared to electric field fluctuations. We show that the hole
hyperfine interaction can have a strong effect on hole spin coherence
measurements through a nuclear feedback effect. The nuclear polarization is
generated through a unique process that is dependent on the anisotropy of the
hole hyperfine interaction and the coherent precession of nuclear spins, giving
rise to strong modulation at the nuclear precession frequency.


title:
Third-order spontaneous parametric down-conversion in thin optical
  fibers as a photon-triplet source

abstract:
  We study the third order spontaneous parametric down conversion (TOSPDC)
process, as a means to generate entangled photon triplets. Specifically, we
consider thin optical fibers as the nonlinear medium to be used as the basis
for TOSPDC in configurations where phase matching is attained through the use
of more than one fiber transverse modes. Our analysis in this paper, which
follows from our earlier paper Optics Letters 36, 190 (2011), aims to supply
experimentalists with the details required in order to design a TOSPDC
photon-triplet source. Specifically, our analysis focuses on the photon triplet
state, on the rate of emission, and on the TOSPDC phasematching characteristics
for the cases of frequency degenerate and frequency nondegenerate TOSPDC.


title: The GALEX Nearby Young-Star Survey

abstract:
  We describe a method that exploits data from the GALEX ultraviolet and WISE
and 2MASS infrared source catalogs, combined with proper motions and empirical
pre-main sequence isochrones, to identify candidate nearby, young, low-mass
stars. Applying our method across the full GALEX- covered sky, we identify 2031
mostly M-type stars that, for an assumed age of 10 (100) Myr, all lie within
~150 (~90) pc of Earth. The distribution of M spectral subclasses among these
~2000 candidate young stars peaks sharply in the range M3-M4; these subtypes
constitute 50% of the sample, consistent with studies of the M star population
in the immediate solar neighborhood. We focus on a subset of 58 of these
candidate young M stars in the vicinity of the Tucana-Horologium Association.
Only 20 of these 58 candidates were detected in the ROSAT All-Sky X-ray Survey
-- reflecting the greater sensitivity of GALEX for purposes of identifying
active nearby, young stars, particularly for stars of type M4 and later. Based
on statistical analysis of the kinematics and/or spectroscopic followup of
these 58 M stars, we find that 50% (29 stars) indeed have properties consistent
with Tuc-Hor membership, while 12 are potential new members of the Columba
Association, and two may be AB Dor moving group members. Hence, ~75% of our
initial subsample of 58 candidates are likely members of young (age ~10-40 Myr)
stellar moving groups within 100 pc, verifying that the stellar color- and
kinematics-based selection algorithms described here can be used to efficiently
isolate nearby, young, low-mass objects from among the field star population.
Future studies will focus on characterizing additional subsamples selected from
among this list of candidate nearby, young M stars.


title: Indexed Induction and Coinduction, Fibrationally

abstract:
  This paper extends the fibrational approach to induction and coinduction
pioneered by Hermida and Jacobs, and developed by the current authors, in two
key directions. First, we present a dual to the sound induction rule for
inductive types that we developed previously. That is, we present a sound
coinduction rule for any data type arising as the carrier of the final
coalgebra of a functor, thus relaxing Hermida and Jacobs' restriction to
polynomial functors. To achieve this we introduce the notion of a quotient
category with equality (QCE) that i) abstracts the standard notion of a
fibration of relations constructed from a given fibration; and ii) plays a role
in the theory of coinduction dual to that played by a comprehension category
with unit (CCU) in the theory of induction. Secondly, we show that inductive
and coinductive indexed types also admit sound induction and coinduction rules.
Indexed data types often arise as carriers of initial algebras and final
coalgebras of functors on slice categories, so we give sufficient conditions
under which we can construct, from a CCU (QCE) U:E \rightarrow B, a fibration
with base B/I that models indexing by I and is also a CCU (resp., QCE). We
finish the paper by considering the more general case of sound induction and
coinduction rules for indexed data types when the indexing is itself given by a
fibration.


title:
Gamma-ray observations of the microquasars Cygnus X-1, Cygnus X-3, GRS
  1915+105, and GX 339-4 with the Fermi Large Area Telescope

abstract:
  Detecting gamma-rays from microquasars is a challenging but worthwhile
endeavor for understanding particle acceleration, the jet mechanism, and for
constraining leptonic/hadronic emission models. We present results from a
likelihood analysis on timescales of 1 d and 10 d of ~4 years worth of
gamma-ray observations (0.1-10 GeV) by Fermi-LAT of Cyg X-1, Cyg X-3, GRS
1915+105, and GX 339-4. Our analysis reproduced all but one of the previous
gamma-ray outbursts of Cyg X-3 as reported with Fermi or AGILE, plus 5 new days
on which Cyg X-3 is detected at a significance of ~5-sigma that are not
reported in the literature. In addition, Cyg X-3 is significantly detected on
10-d timescales outside of known gamma-ray flaring epochs which suggests that
persistent gamma-ray emission from Cyg X-3 has been detected for the first
time. For Cyg X-1, we find three low significance excesses (~3-4-sigma) on
daily timescales that are contemporaneous with gamma-ray flares reported (also
at low significance) by AGILE. Two other microquasars, GRS 1915+105 and GX
339-4, are not detected and we derive 3-sigma upper limits of 2.3e-8 ph/cm2/s
and 1.6e-8 ph/cm2/s, respectively, on the persistent flux in the 0.1-10 GeV
range. These results enable us to define a list of the general conditions that
are necessary for the detection of gamma-rays from microquasars.


title:
New general integral inequalities for some GA-convex and
  quasi-geometrically convex functions via fractional integrals

abstract:
  In this paper, the author introduces the concept of the quasi-geometrically
convex and defines a new identity for fractional integrals. By using of this
identity, author obtains new estimates on generalization of Hadamard, Ostrowski
and Simpson type inequalities for GA-s-convex, quasi-geometrically convex and
(s,m)-GA-convex functions via Riemann Liouville fractional integral.


title: Spontaneous parametric processes in optical fibers: a comparison

abstract:
  We study the processes of spontaneous four wave mixing and of third-order
spontaneous parametric downconversion in optical fibers, as the basis for the
implementation of photon-pair and photon-triplet sources. We present a
comparative analysis of the two processes including expressions for the
respective quantum states and plots of the joint spectral intensity, a
discussion of phasematching characteristics, and expressions for the conversion
efficiency. We have also included a comparative study based on numerical
results for the conversion efficiency for the two sources, as a function of
several key experimental parameters.


title:
Defect-mediated relaxation and non-linear susceptibilities of Rochelle
  salt

abstract:
  The deformable pseudospin Mitsui model is modified in order to take into
account interactions of the ordering dipoles of Rochelle salt with dipoles,
associated with switchable crystal defects. Using the Glauber-type kinetics of
the ordering and defect pseudospins, we calculate the linear, second, and third
order dynamic susceptibilities and piezoelectric coefficients of the system.
The defect-assisted dispersion of the dynamic characteristics below 1 kHz is
described. Behavior of the linear and non-linear susceptibilities close to
T_C1,2 is also satisfactorily described by the presented model.


title: Loss Cone Dynamics

abstract:
  Supermassive black holes can capture or disrupt stars that come sufficiently
close. This article reviews the dynamical processes by which stars or stellar
remnants are placed onto loss-cone orbits and the implications for feeding
rates. The capture rate is well defined for spherical galaxies with nuclear
relaxation times that are shorter than the galaxy's age. However, even the
dense nucleus of the Milky Way may be less than one relaxation time old, and
this is certainly the case for more massive galaxies; the capture rate in such
galaxies is an initial-value problem with poorly-known initial conditions and
the rate can be much higher, or much lower, than the rate in a collisionally
relaxed nucleus. In nonspherical (axisymmetric, triaxial) galaxies, torquing of
orbits by the mean field can dominate perturbations due to random encounters,
leading to much higher capture rates than in the spherical geometry,
particularly in (massive) galaxies with long central relaxation times.
Relativistic precession plays a crucial role in mediating the capture of
compact remnants from regions very near to the black hole, by destroying the
orbital correlations that would otherwise dominate the torques. The complex
dynamics of relativistic loss cones are not yet well enough understood for
accurate estimates of compact-object (EMRI) capture rates to be made.


title: On the existence of orders in semisimple Hopf algebras

abstract:
  We show that there is a family of complex semisimple Hopf algebras that do
not admit a Hopf order over any number ring. They are Drinfel'd twists of
certain group algebras. The twist contains a scalar fraction which makes
impossible the definability of such Hopf algebras over number rings. We also
prove that a complex semisimple Hopf algebra satisfies Kaplansky's sixth
conjecture if and only if it admits a weak order, in the sense of Rumynin and
Lorenz, over the integers.


title:
Anomalous compressibility of ferropericlase throughout the iron spin
  crossover

abstract:
  The thermoelastic properties of ferropericlase Mg1-xFexO (x = 0.1875)
throughout the iron high-to-low spin crossover have been investigated by first
principles at Earth's lower mantle conditions. This crossover has important
consequences for elasticity such as an anomalous bulk modulus (KS) reduction.
At room temperature the anomaly is somewhat sharp in pressure but broadens with
increasing temperature. Along a typical geotherm it occurs across most of the
lower mantle with a more significant KS reduction around 1400-1600 km depth.
This anomaly might also cause a reduction in the effective activation energy
for viscous creep and lead to a viscosity minimum in the mid-lower mantle, in
apparent agreement with results from inversion of data related with mantle
convection and postglacial rebound.


title: Fuzzy Fibers: Uncertainty in dMRI Tractography

abstract:
  Fiber tracking based on diffusion weighted Magnetic Resonance Imaging (dMRI)
allows for noninvasive reconstruction of fiber bundles in the human brain. In
this chapter, we discuss sources of error and uncertainty in this technique,
and review strategies that afford a more reliable interpretation of the
results. This includes methods for computing and rendering probabilistic
tractograms, which estimate precision in the face of measurement noise and
artifacts. However, we also address aspects that have received less attention
so far, such as model selection, partial voluming, and the impact of
parameters, both in preprocessing and in fiber tracking itself. We conclude by
giving impulses for future research.


title: Approximate Cech Complexes in Low and High Dimensions

abstract:
  \v{C}ech complexes reveal valuable topological information about point sets
at a certain scale in arbitrary dimensions, but the sheer size of these
complexes limits their practical impact. While recent work introduced
approximation techniques for filtrations of (Vietoris-)Rips complexes, a
coarser version of \v{C}ech complexes, we propose the approximation of \v{C}ech
filtrations directly.
  For fixed dimensional point set $S$, we present an approximation of the
\v{C}ech filtration of $S$ by a sequence of complexes of size linear in the
number of points. We generalize well-separated pair decompositions (WSPD) to
well-separated simplicial decomposition (WSSD) in which every simplex defined
on $S$ is covered by some element of WSSD. We give an efficient algorithm to
compute a linear-sized WSSD in fixed dimensional spaces. Using a WSSD, we then
present a linear-sized approximation of the filtration of \v{C}ech complex of
$S$.
  We also present a generalization of the known fact that the Rips complex
approximates the \v{C}ech complex by a factor of $\sqrt{2}$. We define a class
of complexes that interpolate between \v{C}ech and Rips complexes and that,
given any parameter $\eps > 0$, approximate the \v{C}ech complex by a factor
$(1+\eps)$. Our complex can be represented by roughly $O(n^{\lceil
1/2\eps\rceil})$ simplices without any hidden dependence on the ambient
dimension of the point set. Our results are based on an interesting link
between \v{C}ech complex and coresets for minimum enclosing ball of
high-dimensional point sets. As a consequence of our analysis, we show improved
bounds on coresets that approximate the radius of the minimum enclosing ball.


title:
The Stagger-grid: A Grid of 3D Stellar Atmosphere Models - II.
  Horizontal and Temporal Averaging and Spectral Line Formation

abstract:
  We study the implications of averaging methods with different reference depth
scales for 3D hydrodynamical model atmospheres computed with the Stagger-code.
The temporally and spatially averaged (hereafter denoted as <3D>) models are
explored in the light of local thermodynamic equilibrium (LTE) spectral line
formation by comparing spectrum calculations using full 3D atmosphere
structures with those from <3D> averages. We explore methods for computing mean
<3D> stratifications from the Stagger-grid time-dependent 3D radiative hydro-
dynamical atmosphere models by considering four different reference depth
scales (geometrical depth, column-mass density, and two optical depth scales).
Furthermore, we investigate the influence of alternative averages (logarithmic
or enforced hydrostatic equilibrium, flux-weighted temperatures). For the line
formation we compute curves of growth for Fe i and Fe ii lines in LTE . The
resulting <3D> stratifications for the four reference depth scales can be
considerably different. We find typically that in the upper atmosphere and in
the superadiabatic region just below the optical surface, where the temperature
and density fluctuations are highest, the differences become considerable and
increase for higher Teff, lower logg, and lower [Fe/H]. The differential
comparison of spectral line formation shows distinctive differences depending
on which <3D> model is applied. The averages over layers of constant
column-mass density yield the best mean <3D> representation for LTE line
formation, while the averages on layers at constant geometrical height are the
least appropriate. Unexpectedly, the usually preferred averages over layers of
constant optical depth are prone to the increasing interference of the reversed
granulation towards higher effective temperature, in particular at low
metallicity.


title:
Stability and plasticity of silicon nanowires: the role of wire
  perimeter

abstract:
  We investigated the properties of stability and plasticity of silicon
nanowires using molecular dynamics simulations. We considered nanowires with
<100>, <110> and <112> growth directions with several diameters and surface
facet configurations. We found that the wire perimeter, and not the wire
diameter, is the meaningful dimensional parameter. As a result, the surface
facets play a central role on the nanowire energy, that follows a universal
scaling law. Additionally, we have computed the response of a silicon nanowire
to external load. The results were compared to available experimental and ab
initio data.


title: A Poincare lemma in Geometric Quantisation

abstract:
  This article presents a Poincare lemma for the Kostant complex, used to
compute geometric quantisation, when the polarisation is given by a Lagrangian
foliation defined by an integrable system with nondegenerate singularities.


title: Corrections to scaling in the critical theory of deconfined criticality

abstract:
  Inspired by recent conflicting views on the order of the phase transition
from an antiferromagnetic Neel state to a valence bond solid, we use the
functional renormalization group to study the underlying quantum critical field
theory which couples two complex matter fields to a non-compact gauge field. In
our functional renormalization group approach we only expand in covariant
derivatives of the fields and use a truncation in which the full field
dependence of all wave-function renormalization functions is kept. While we do
find critical exponents which agree well with some quantum Monte Carlo studies
and support the scenario of deconfined criticality, we also obtain an
irrelevant eigenvalue of small magnitude, leading to strong corrections to
scaling and slow convergence in related numerical studies.


title: Deformations of log-symplectic structures

abstract:
  We describe the space of Poisson bivectors near a log-symplectic structure up
to small diffeomorphisms.


title:
3d transition metal impurities in diamond: electronic properties and
  chemical trends

abstract:
  First principles calculations have been used to investigate the trends on the
properties of isolated 3d transition metal impurities (from Sc to Cu) in
diamond. Those impurities have small formation energies in the substitutional
or double semi-vacancy sites, and large energies in the interstitial one. Going
from Sc to Cu, the 3d-related energy levels in the bandgap move from the top of
the bandgap toward the valence band in all three sites. Trends in electronic
properties and transition energies of the impurities, in the substitutional or
interstitial sites, are well described by a simple microscopic model
considering the electronic occupation of the 3d-related levels. On the other
hand, for the impurities in the double semi-vacancy site, there is a weak
interaction between the divacancy- and the 3d-related orbitals, resulting in in
vacancy- and 3d-related levels in the materials bandgap.


title:
Linear noise approximation for stochastic oscillations of intracellular
  calcium

abstract:
  A stochastic model of intracellular calcium oscillations is analytically
studied. The governing master equation is expanded under the linear noise
approximation and a closed prediction for the power spectrum of fluctuations
analytically derived. A peak in the obtained power spectrum profile signals the
presence of stochastic, noise induced, oscillations which extend also outside
the region where a deterministic limit cycle is predicted to occur.


title:
Combinatorial theory of the semiclassical evaluation of transport
  moments II: Algorithmic approach for moment generating functions

abstract:
  Electronic transport through chaotic quantum dots exhibits universal
behaviour which can be understood through the semiclassical approximation.
Within the approximation, transport moments reduce to codifying classical
correlations between scattering trajectories. These can be represented as
ribbon graphs and we develop an algorithmic combinatorial method to generate
all such graphs with a given genus. This provides an expansion of the linear
transport moments for systems both with and without time reversal symmetry. The
computational implementation is then able to progress several orders higher
than previous semiclassical formulae as well as those derived from an
asymptotic expansion of random matrix results. The patterns observed also
suggest a general form for the higher orders.


title:
Lattice formulation of three-dimensional ${\cal N}=4$ gauge theory with
  fundamental matter fields

abstract:
  We construct lattice action for three-dimensional ${\cal N}=4$ supersymmetric
gauge theory with matter fields in the fundamental representation.


title: Iterative Scaling in Curved Exponential Families

abstract:
  The paper describes a generalized iterative proportional fitting procedure
which can be used for maximum likelihood estimation in a special class of the
general log-linear model. The models in this class, called relational, apply to
multivariate discrete sample spaces which do not necessarily have a Cartesian
product structure and may not contain an overall effect. When applied to the
cell probabilities, the models without the overall effect are curved
exponential families and the values of the sufficient statistics are reproduced
by the MLE only up to a constant of proportionality. The paper shows that
Iterative Proportional Fitting, Generalized Iterative Scaling and Improved
Iterative Scaling, fail to work for such models. The algorithm proposed here is
based on iterated Bregman projections. As a by-product, estimates of the
multiplicative parameters are also obtained.


title:
A particle filter approach to approximate posterior Cram\'er-Rao lower
  bound

abstract:
  The posterior Cram\'er-Rao lower bound (PCRLB) derived in Tichavsk\'y et al.,
1998, provides a bound on the mean square error (MSE) obtained with any
non-linear state filter. Computing the PCRLB involves solving complex,
multi-dimensional expectations, which do not lend themselves to an easy
analytical solution. Furthermore, any attempt to approximate it using numerical
or simulation based approaches require a priori access to the true states,
which may not be available, except in simulations or in carefully designed
experiments. To allow recursive approximation of the PCRLB when the states are
hidden or unmeasured, a new approach based on sequential Monte-Carlo (SMC) or
particle filters (PF) is proposed. The approach uses SMC methods to estimate
the hidden states using a sequence of the available sensor measurements. The
developed method is general and can be used to approximate the PCRLB in
non-linear systems with non-Gaussian state and sensor noise. The efficacy of
the developed method is illustrated on two simulation examples, including a
practical problem of ballistic target tracking at re-entry phase.


title: Sequential Selection of Correlated Ads by POMDPs

abstract:
  Online advertising has become a key source of revenue for both web search
engines and online publishers. For them, the ability of allocating right ads to
right webpages is critical because any mismatched ads would not only harm web
users' satisfactions but also lower the ad income. In this paper, we study how
online publishers could optimally select ads to maximize their ad incomes over
time. The conventional offline, content-based matching between webpages and ads
is a fine start but cannot solve the problem completely because good matching
does not necessarily lead to good payoff. Moreover, with the limited display
impressions, we need to balance the need of selecting ads to learn true ad
payoffs (exploration) with that of allocating ads to generate high immediate
payoffs based on the current belief (exploitation). In this paper, we address
the problem by employing Partially observable Markov decision processes
(POMDPs) and discuss how to utilize the correlation of ads to improve the
efficiency of the exploration and increase ad incomes in a long run. Our
mathematical derivation shows that the belief states of correlated ads can be
naturally updated using a formula similar to collaborative filtering. To test
our model, a real world ad dataset from a major search engine is collected and
categorized. Experimenting over the data, we provide an analyse of the effect
of the underlying parameters, and demonstrate that our algorithms significantly
outperform other strong baselines.


title:
Modelling Baryon Acoustic Oscillations with Perturbation Theory and
  Stochastic Halo Biasing

abstract:
  In this work we investigate the generation of mock halo catalogues based on
perturbation theory and nonlinear stochastic biasing with the novel
PATCHY-code. In particular, we use Augmented Lagrangian Perturbation Theory
(ALPT) to generate a dark matter density field on a mesh starting from Gaussian
fluctuations and to compute the peculiar velocity field. ALPT is based on a
combination of second order LPT (2LPT) on large scales and the spherical
collapse model on smaller scales. We account for the systematic deviation of
perturbative approaches from N-body simulations together with halo biasing
adopting an exponential bias model. We then account for stochastic biasing by
defining three regimes: a low, an intermediate and a high density regime, using
a Poisson distribution in the intermediate regime and the negative binomial
distribution to model over-dispersion in the high density regime. Since we
focus in this study on massive halos, we suppress the generation of halos in
the low density regime. The various nonlinear and stochastic biasing
parameters, and density thresholds (five) are calibrated with the large
BigMultiDark N-body simulation to match the power spectrum of the corresponding
halo population. Our mock catalogues show power spectra, both in real- and
redshift-space, which are compatible with N-body simulations within about 2% up
to k ~ 1 h Mpc^-1 at z = 0.577 for a sample of halos with the typical BOSS
CMASS galaxy number density. The corresponding correlation functions are
compatible down to a few Mpc. We also find that neglecting over-dispersion in
high density regions produces power spectra with deviations of 10% at k ~ 0.4 h
Mpc^-1. These results indicate the need to account for an accurate statistical
description of the galaxy clustering for precise studies of large-scale
surveys.


title:
Two step multiple comparisons procedures for positively dependent data
  with application to detecting differences in human brain network topologies

abstract:
  We consider the problem of testing positively dependent multiple hypotheses
assuming that a prior information about the dependence structure is available.
We propose two-step multiple comparisons procedures that exploit the prior
information of the dependence structure, without relying on strong assumptions.
In the first step, we group the tests into subsets where tests are supposed to
be positively dependent and in each of which we compute the standardized mean
of the test scores. Given the subset mean scores or equivalently the subsets
p-values, we apply a first screening at a predefined threshold, which results
in two types of subsets. Based on this typing, the original single test
p-values are modified such that they can be used in conjunction with any
multiple comparison procedure. We show by means of different simulation that
power is gained with the proposed two-step methods, and compare it with
traditional multiple comparison procedures. As an illustration, our method is
applied on real data comparing topological differences between two groups of
human brain networks.


title: Hyers-Ulam stability of certain singular linear differential equations

abstract:
  We establish the Hyers-Ulam stability of certain linear first-order
differential equations with singularities. We then extend these results to
higher-order singular linear differential equations that can be written with
these first-order factors. An example of our results is given for a
second-order singular linear differential equation that is not be covered by
the current literature in this area.


title: Theory of genuine tripartite nonlocality of Gaussian states

abstract:
  We investigate the genuine multipartite nonlocality of three-mode Gaussian
states of continuous variable systems. For pure states, we present a simplified
procedure to obtain the maximum violation of the Svetlichny inequality based on
displaced parity measurements, and we analyze its interplay with genuine
tripartite entanglement measured via Renyi-2 entropy. The maximum Svetlichny
violation admits tight upper and lower bounds at fixed tripartite entanglement.
For mixed states, no violation is possible when the purity falls below 0.86. We
also explore a set of recently derived weaker inequalities for three-way
nonlocality, finding violations for all tested pure states. Our results provide
a strong signature for the nonclassical and nonlocal nature of Gaussian states
despite their positive Wigner function, and lead to precise recipes for its
experimental verification.


title: Black Hole Demography: From scaling relations to models

abstract:
  In this contributed paper I review our current knowledge of the local Black
Hole (BH) scaling relations, and their impact on the determination of the local
BH mass function. I particularly emphasize the remaining systematic
uncertainties impinging upon a secure determination of the BH mass function and
how progress can be made. I then review and discuss the evidence for a
different time evolution for separate BH-galaxy scaling relations, and how
these independent empirical evidences can be reconciled with the overall
evolution of the structural properties of the host galaxies. I conclude
discussing BH demography in the context of semi-empirical continuity accretion
models, as well as more complex evolutionary models, emphasizing the general
constraints we can set on them.


title:
Concatenated Coding Using Linear Schemes for Gaussian Broadcast Channels
  with Noisy Channel Output Feedback

abstract:
  Linear coding schemes have been the main choice of coding for the additive
white Gaussian noise broadcast channel (AWGN-BC) with noiseless feedback in the
literature. The achievable rate regions of these schemes go well beyond the
capacity region of the AWGN-BC without feedback. In this paper, a concatenating
coding design for the $K$-user AWGN-BC with noisy feedback is proposed that
relies on linear feedback schemes to achieve rate tuples outside the
no-feedback capacity region. Specifically, a linear feedback code for the
AWGN-BC with noisy feedback is used as an inner code that creates an effective
single-user channel from the transmitter to each of the receivers, and then
open-loop coding is used for coding over these single-user channels. An
achievable rate region of linear feedback schemes for noiseless feedback is
shown to be achievable by the concatenated coding scheme for sufficiently small
feedback noise level. Then, a linear feedback coding scheme for the $K$-user
symmetric AWGN-BC with noisy feedback is presented and optimized for use in the
concatenated coding scheme. Lastly, we apply the concatenated coding design to
the two-user AWGN-BC with a single noisy feedback link from one of the
receivers.


title:
Generalized Fermat's principle and action for light rays in a curved
  spacetime

abstract:
  We start with formulation of the generalized Fermat's principle for light
propagation in a curved spacetime. We apply Pontryagin's minimum principle of
the optimal control theory and obtain an effective Hamiltonian for null
geodesics in a curved spacetime. We explicitly demonstrate that dynamical
equations for this Hamiltonian correctly reproduce null geodesic equations.
Other forms of the action for light rays in a curved spacetime are also
discussed.


title:
Algorithms for computing the optimal Lipschitz constant of interpolants
  with Lipschitz derivative

abstract:
  One classical measure of the quality of an interpolating function is its
Lipschitz constant. In this paper we consider interpolants with additional
smoothness requirements, in particular that their derivatives be Lipschitz. We
show that such a measure of quality can be easily computed, giving two
algorithms, one optimal in the dimension of the data, the other optimal in the
number of points to be interpolated.


title:
Toroidal graphs containing neither $K_5^{-}$ nor 6-cycles are
  4-choosable

abstract:
  The choosability $\chi_\ell(G)$ of a graph $G$ is the minimum $k$ such that
having $k$ colors available at each vertex guarantees a proper coloring. Given
a toroidal graph $G$, it is known that $\chi_\ell(G)\leq 7$, and
$\chi_\ell(G)=7$ if and only if $G$ contains $K_7$. Cai, Wang, and Zhu proved
that a toroidal graph $G$ without 7-cycles is 6-choosable, and $\chi_\ell(G)=6$
if and only if $G$ contains $K_6$. They also prove that a toroidal graph $G$
without 6-cycles is 5-choosable, and conjecture that $\chi_\ell(G)=5$ if and
only if $G$ contains $K_5$. We disprove this conjecture by constructing an
infinite family of non-4-colorable toroidal graphs with neither $K_5$ nor
cycles of length at least 6; moreover, this family of graphs is embeddable on
every surface except the plane and the projective plane. Instead, we prove the
following slightly weaker statement suggested by Zhu: toroidal graphs
containing neither $K^-_5$ (a $K_5$ missing one edge) nor 6-cycles are
4-choosable. This is sharp in the sense that forbidding only one of the two
structures does not ensure that the graph is 4-choosable.


title:
A dwt, dct and svd based watermarking technique to protect the image
  piracy

abstract:
  With the rapid development of information technology and multimedia, the use
of digital data is increasing day by day. So it becomes very essential to
protect multimedia information from piracy and also it is challenging. A great
deal of Copyright owners is worried about protecting any kind of illegal
repetition of their information. Hence, facing all these kinds of problems
development of the techniques is very important. Digital watermarking
considered as a solution to prevent the multimedia data. In this paper, an idea
of watermarking is proposed and implemented. In proposed watermarking method,
the original image is rearranged using zigzag sequence and DWT is applied on
rearranged image. Then DCT and SVD are applied on all high bands LH, HL and HH.
Watermark is then embedded by modifying the singular values of these bands.
Extraction of watermark is performed by the inversion of watermark embedding
process. For choosing of these three bands it gives facility of mid-band and
pure high band that ensures good imperceptibility and more robustness against
different kinds of attacks.


title:
An imporved decentralized approach for tracking multiple mobile targets
  through ZigBee WSNs

abstract:
  Target localization and tracking problems in WSNs have received considerable
attention recently, driven by the requirement to achieve high localization
accuracy, with the minimum cost possible. In WSN based tracking applications,
it is critical to know the current location of any sensor node with the minimum
energy consumed. This paper focuses on the energy consumption issue in terms of
communication between nodes whenever the localization information is
transmitted to a sink node. Tracking through WSNs can be categorized into
centralized and decentralized systems. Decentralized systems offer low power
consumption when deployed to track a small number of mobile targets compared to
the centralized tracking systems. However, in several applications, it is
essential to position a large number of mobile targets. In such applications,
decentralized systems offer high power consumption, since the location of each
mobile target is required to be transmitted to a sink node, and this increases
the power consumption for the whole WSN. In this paper, we propose a power
efficient decentralized approach for tracking a large number of mobile targets
while offering reasonable localization accuracy through ZigBee network.


title: Presenting queer Schur superalgebras

abstract:
  Associated to the two types of finite dimensional simple superalgebras, there
are the general linear Lie superalgebra and the queer Lie superalgebra. The
universal enveloping algebras of these Lie superalgebras act on the tensor
spaces of the natural representations and, thus, define certain finite
dimensional quotients, the Schur superalgebras and the queer Schur
superalgebra. In this paper, we introduce the quantum analogue of the queer
Schur superalgebra and investigate the presentation problem for both the queer
Schur superalgebra and its quantum analogue.


title: On the crossing number of K_13

abstract:
  Since the crossing number of K_{12} is now known to be 150, it is well-known
that simple counting arguments and Kleitman's parity theorem for the crossing
number of K_{2n+1} combine with a specific drawing of K_{13} to show that the
crossing number of K_{13} is one of the numbers in {217,219,221,223,225}. We
show that the crossing number is not 217.


title: A Sobolev estimate for the adjoint restriction operator

abstract:
  In this note we consider the adjoint restriction estimate for hypersurface
under additional regularity assumption. We obtain the optimal $H^s$-$L^q$
estimate and its mixed norm generalization. As applications we prove some
weighted Strichartz estimates for the propagator
$e^{it(-\Delta)^{\alpha/2}}\varphi$, $\alpha>0$.


title:
Optimizing the Determination of the Neutrino Mixing Angle $\theta_{13}$
  from Reactor Data

abstract:
  The technical breakthroughs of multiple detectors developed by Daya Bay and
RENO collaborations have gotten great attention. Yet the optimal determination
of neutrino mixing parameters from reactor data depends on the statistical
method and demands equal attention. We find that a straightforward method using
a minimal parameters will generally outperform a multi-parameter method by
delivering more reliable values with sharper resolution. We review standard
confidence levels and statistical penalties for models using extra parameters,
and apply those rules to our analysis. We find that the methods used in recent
work of the Daya Bay and RENO collaborations have several undesirable
properties. The existing work also uses non-standard measures of significance
which we are unable to explain. A central element of the current methods
consists of variationally fitting many more parameters than data points. As a
result the experimental resolution of $\sin ^{2}(2\theta _{13})$ is degraded.
The results also become extremely sensitive to certain model parameters that
can be adjusted arbitrarily. The number of parameters to include in evaluating
significance is an important issue that has generally been overlooked. The
measures of significance applied previously would be consistent if and only if
all parameters but one were considered to have no physical relevance for the
experiment's hypothesis test. Simpler, more transparent methods can improve the
determination of the mixing angle $\theta _{13}$ from reactor data, and exploit
the advantages from superb hardware technique of the experiments. We anticipate
that future experimental analysis will fully exploit those advantages.


title:
A White Light Interferometric Microscope for Measuring Dose-Dependent
  Reversible Photodegradation

abstract:
  We have developed a white light interferometric microscope (WLIM), which can
spatially resolve the change in the complex index of refraction and apply it to
study reversible photodegradation of 1,4-Diamino-9,10-anthraquinone doped into
(poly)methyl methacrylate. The measured change in absorbance is consistent with
standard spectrometer measurements. The refractive index of a pristine sample
measured with the WLIM is also found to be consistent with the spectrum found
by independent means (F. Yakuphanoglu and B. Senkal, Electrical conductivity,
photoconductivity, and optical properties of poly(1,4 diaminoanthraquinone)
organic semiconductor for optoelectronic applications, Polym. Adv. Technol. 19,
1193 to 1198 (2008)). We report on measurements of the change in refractive
index due to photodegradation, which is found to be consistent with Embaye's
two population model (N. Embaye et al., Mechanisms of reversible
photodegradation in disperse orange 11 dye doped in PMMA polymer, J. Chem.
Phys. 129, 054504 (2008)). We show that the WLIM can be used as a powerful tool
to image the complex refractive index of a planar surface and to detect changes
in a material's optical properties.


title:
Optimal Bounds on Approximation of Submodular and XOS Functions by
  Juntas

abstract:
  We investigate the approximability of several classes of real-valued
functions by functions of a small number of variables ({\em juntas}). Our main
results are tight bounds on the number of variables required to approximate a
function $f:\{0,1\}^n \rightarrow [0,1]$ within $\ell_2$-error $\epsilon$ over
the uniform distribution: 1. If $f$ is submodular, then it is $\epsilon$-close
to a function of $O(\frac{1}{\epsilon^2} \log \frac{1}{\epsilon})$ variables.
This is an exponential improvement over previously known results. We note that
$\Omega(\frac{1}{\epsilon^2})$ variables are necessary even for linear
functions. 2. If $f$ is fractionally subadditive (XOS) it is $\epsilon$-close
to a function of $2^{O(1/\epsilon^2)}$ variables. This result holds for all
functions with low total $\ell_1$-influence and is a real-valued analogue of
Friedgut's theorem for boolean functions. We show that $2^{\Omega(1/\epsilon)}$
variables are necessary even for XOS functions.
  As applications of these results, we provide learning algorithms over the
uniform distribution. For XOS functions, we give a PAC learning algorithm that
runs in time $2^{poly(1/\epsilon)} poly(n)$. For submodular functions we give
an algorithm in the more demanding PMAC learning model (Balcan and Harvey,
2011) which requires a multiplicative $1+\gamma$ factor approximation with
probability at least $1-\epsilon$ over the target distribution. Our uniform
distribution algorithm runs in time $2^{poly(1/(\gamma\epsilon))} poly(n)$.
This is the first algorithm in the PMAC model that over the uniform
distribution can achieve a constant approximation factor arbitrarily close to 1
for all submodular functions. As follows from the lower bounds in (Feldman et
al., 2013) both of these algorithms are close to optimal. We also give
applications for proper learning, testing and agnostic learning with value
queries of these classes.


title: Infra-solvmanifolds of $\Sol_1^4$-geometry

abstract:
  The purpose of this paper is to classify all compact manifolds modeled on the
4-dimensional solvable Lie group $Sol_1^4$. The maximal compact subgroup of
$Isom(Sol_1^4)$ is $D_4=\mathbb Z_4\rtimes\mathbb Z_2$. We shall exhibit an
infra-solvmanifold with $Sol_1^4$-geometry whose holonomy is $D_4$. This
implies that all possible holonomy groups do occur; $\{1\}$, $\mathbb Z_2$ (5
families), $\mathbb Z_4$, $\mathbb Z_2\times\mathbb Z_2$ (5 families),and
$\mathbb Z_4\rtimes\mathbb Z_2$ (2 families). This includes the classification
of 3-dimensional infra-$Sol$ manifolds.


title:
Incorporating the influence of sub-grid heterogeneity in regional-scale
  contaminant transport models

abstract:
  Numerical transport models based on the advection-dispersion equation (ADE)
are built on the assumption that sub-grid cell transport is Fickian such that
dispersive spreading around the average velocity is symmetric and without
significant tailing on the front edge of a solute plume. However, anomalous
diffusion in the form of super-diffusion due to preferential pathways in an
aquifer has been observed in field data, challenging the assumption of Fickian
dispersion at the local scale. This study develops a fully Lagrangian method to
simulate sub-grid super-diffusion in a multi-dimensional regional-scale
transport. The underlying concept is based on previous observations that
solutions to space-fractional ADEs, which can describe super-diffusive
dispersion, can be obtained by transforming solutions of classical ADEs. The
transformations are equivalent to randomizing particle travel time or relative
velocity for each model time step. Here, the time randomizing procedure known
as subordination is applied to flow field output from MODFLOW simulations.
Numerical tests check the applicability of the novel method in mapping
regional-scale super-diffusive transport conditioned on local properties of
multi-dimensional heterogeneous media.


title: Opinion Particles: Classical Physics and Opinion Dynamics

abstract:
  A model for Opinion Particles, based on Bayesian-inspired models of Opinion
Dynamics such as the CODA model is presented. By extending the discrete time
characteristic of those models to continuous time, a theory for the movement of
opinion particles is obtained, based only on inference ideas. This will allow
inertia to be obtained as a consequence of an extended CODA model. For the
general case, we will see that the likelihoods are associated with variables
such as velocity and acceleration of the particles. Newtonian forces are easily
defined and the relationship between a force and the equivalent likelihood
provided. The case of the harmonic oscillator is solved as an example, to
illustrate clearly the relationship between Opinion Particles and Mechanics.
Finally, possible paths to apply these results to General Relativity are
debated.


title:
Anomalously Steep Reddening Law in Quasars: An Exceptional Example
  Observed in IRAS14026+4341

abstract:
  A fraction of the heavily reddened quasars require a reddening curve which is
even steeper than that of the Small Magellanic Cloud. In this paper, we
thoroughly characterize the anomalously steep reddening law in quasars, via an
exceptional example observed in IRAS 14026+4341. By comparing the observed
spectrum to the quasar composite spectrum, we derive a reddening curve in the
rest-frame wavelength range of 1200 {\AA}--10000 {\AA}. It is featured with a
steep rise at wavelengths shorter than 3000 {\AA}, but no significant reddening
at longer wavelengths. The absence of dust reddening in optical continuum is
confirmed by the normal broad-line Balmer decrement (the H$\alpha$/H$\beta$
ratio) in IRAS 14026+4341. The anomalous reddening curve can be satisfactorily
reproduced by a dust model containing silicate grains in a power-law size
distribution, $dn(a)/da \propto a^{-1.4}$, truncated at a maximum size
$a_{max}=70 {\rm nm}$. The unusual size distribution may be caused by the
destruction of large "stardust" grains by quasar activities or a different dust
formation mechanism (i.e., the in situ formation of dust grains in quasar
outflows). It is also possible that the analogies of the dust grains observed
toward the Galactic center is responsible for the steep reddening curve. In
addition, we find that IRAS 14026+4341 is a weak emission-line quasar (i.e.,
PHL 1811 analogies) with heavy dust reddening and blueshifted broad absorption
lines.


title: Energy-aware Application Scaling on a Cloud

abstract:
  Cloud elasticity - the ability to use as much resources as needed at any
given time - and low cost - a user pays only for the resources it consumes -
represent solid incentives for many organizations to migrate some of their
computational activities to a public cloud. As the interest in cloud computing
grows, so does the size of the cloud computing centers and their energy
footprint. The realization that power consumption of cloud computing centers is
significant and it is expected to increase substantially in the future
motivates our interest in scheduling and scaling algorithms which minimize
power consumption. We propose energy-aware application scaling and resource
management algorithms. Though targeting primarily the Infrastructure as a
Service (IaaS), the system models and the algorithms we propose can be applied
to the other cloud delivery models and to private clouds.


title: Tilting Modules in Truncated Categories

abstract:
  We begin the study of a tilting theory in certain truncated categories of
modules $\mathcal G(\Gamma)$ for the current Lie algebra associated to a
finite-dimensional complex simple Lie algebra, where $\Gamma = P^+ \times J$,
$J$ is an interval in $\mathbb Z$, and $P^+$ is the set of dominant integral
weights of the simple Lie algebra. We use this to put a tilting theory on the
category $\mathcal G(\Gamma')$ where $\Gamma' = P' \times J$, where
$P'\subseteq P^+$ is saturated. Under certain natural conditions on $\Gamma'$,
we note that $\mathcal G(\Gamma')$ admits full tilting modules.


title:
Very Low Mass Stellar and Substellar Companions to Solar-like Stars From
  MARVELS IV: A Candidate Brown Dwarf or Low-Mass Stellar Companion to HIP
  67526

abstract:
  We report the discovery of a candidate brown dwarf or a very low mass stellar
companion (MARVELS-5b) to the star HIP 67526 from the Multi-object APO Radial
Velocity Exoplanet Large-area Survey (MARVELS). The radial velocity curve for
this object contains 31 epochs spread over 2.5 years. Our Keplerian fit using a
Markov Chain Monte Carlo approach, reveals that the companion has an orbital
period of $90.2695^{+0.0188}_{-0.0187}$ days, an eccentricity of $0.4375 \pm
0.0040$ and a semi-amplitude of $2948.14^{+16.65}_{-16.55}$ m s$^{-1}$. Using
additional high-resolution spectroscopy, we find the host star has an effective
temperature $T_{\rm{eff}}=6004 \pm 34$ K, a surface gravity $\log g$ [cgs]
$=4.55 \pm 0.17$ and a metallicity [Fe/H] $=+0.04 \pm 0.06$. The stellar mass
and radius determined through the empirical relationship of Torres et al.
(2010), yields 1.10$\pm$0.09 $M_{\sun}$ and 0.92$\pm$0.19 $R_{\sun}$. The
minimum mass of MARVELS-5b is $65.0 \pm 2.9 M_{Jup}$, indicating that it is
likely to be either a brown dwarf or a very low mass star, thus occupying a
relatively sparsely-populated region of the mass function of companions to
solar-type stars. The distance to this system is 101$\pm$10 pc from the
astrometric measurements of Hipparcos. No stellar tertiary is detected in the
high-contrast images taken by either FastCam lucky imaging or Keck adaptive
optics imaging, ruling out any star with mass greater than 0.2$M_{\sun}$ at a
separation larger than 40 AU.


title: $B_{1g}$-like pairing states in two-leg ladder iron superconductors

abstract:
  Motivated by the recent report of superconductivity in Fe-based ladder
materials, we study the pairing state of a multi-orbital t-J model defined on
two-leg ladders using the standard mean-field theory. We find that the
superconducting order parameters change sign between the $d_{xz}$ and $d_{yz}$
orbitals in most of the phase diagram. By analogy with the two-dimensional Fe
planes, we conclude that the leading pairing channel of this state belongs to
the $B_{1g}$ symmetry class, which is distinct from the common $s_{\pm}$ gap
with the $A_{1g}$ symmetry. By smoothly interpolating from planes into ladders,
we show that a first-order transition occurs between these two competing phases
when the dimension of the system is reduced.


title:
Improving the quality of Gujarati-Hindi Machine Translation through
  part-of-speech tagging and stemmer-assisted transliteration

abstract:
  Machine Translation for Indian languages is an emerging research area.
Transliteration is one such module that we design while designing a translation
system. Transliteration means mapping of source language text into the target
language. Simple mapping decreases the efficiency of overall translation
system. We propose the use of stemming and part-of-speech tagging for
transliteration. The effectiveness of translation can be improved if we use
part-of-speech tagging and stemming assisted transliteration.We have shown that
much of the content in Gujarati gets transliterated while being processed for
translation to Hindi language.


title:
Light quark pseudoscalar densities and anomaly matrix elements for
  {\eta} and {\eta}' mesons

abstract:
  Matrix elements of flavor-diagonal light quark pseudoscalar densities and
axial anomaly operators between vacuum and {\eta} and {\eta}' meson states have
been determined. This has been done by evaluating current-current correlators
of octet-octet and octet-singlet axial currents using QCD sum rules. The
numerical values obtained for the matrix elements compare well with those
obtained in the current literature.


title: Boolean algebras and Lubell functions

abstract:
  Let $2^{[n]}$ denote the power set of $[n]:=\{1,2,..., n\}$. A collection
$\B\subset 2^{[n]}$ forms a $d$-dimensional {\em Boolean algebra} if there
exist pairwise disjoint sets $X_0, X_1,..., X_d \subseteq [n]$, all non-empty
with perhaps the exception of $X_0$, so that $\B={X_0\cup \bigcup_{i\in I}
X_i\colon I\subseteq [d]}$. Let $b(n,d)$ be the maximum cardinality of a family
$\F\subset 2^X$ that does not contain a $d$-dimensional Boolean algebra.
Gunderson, R\"odl, and Sidorenko proved that $b(n,d) \leq c_d n^{-1/2^d} \cdot
2^n$ where $c_d= 10^d 2^{-2^{1-d}}d^{d-2^{-d}}$.
  In this paper, we use the Lubell function as a new measurement for large
families instead of cardinality. The Lubell value of a family of sets $\F$ with
$\F\subseteq \tsupn$ is defined by $h_n(\F):=\sum_{F\in \F}1/{{n\choose |F|}}$.
We prove the following Tur\'an type theorem. If $\F\subseteq 2^{[n]}$ contains
no $d$-dimensional Boolean algebra, then $h_n(\F)\leq 2(n+1)^{1-2^{1-d}}$ for
sufficiently large $n$. This results implies $b(n,d) \leq C n^{-1/2^d} \cdot
2^n$, where $C$ is an absolute constant independent of $n$ and $d$. As a
consequence, we improve several Ramsey-type bounds on Boolean algebras. We also
prove a canonical Ramsey theorem for Boolean algebras.


title:
Long Term Spectral Evolution of Tidal Disruption Candidates Selected by
  Strong Coronal Lines

abstract:
  We present results of follow-up optical spectroscopic observations of seven
rare, extreme coronal line emitting galaxies reported by Wang et al. (2012)
with Multi-Mirror Telescope (MMT). Large variations in coronal lines are found
in four objects, making them strong candidates of tidal disruption events
(TDE). For the four TDE candidates, all the coronal lines with ionization
status higher than [Fe VII] disappear within 5-9 years. The [Fe VII] faded by a
factor of about five in one object (J0952+2143) within 4 years, whereas emerged
in other two without them previously. A strong increment in the [O III] flux is
observed, shifting the line ratios towards the loci of active galactic nucleus
on the BPT diagrams. Surprisingly, we detect a non-canonical [O III]5007/[O
III]4959 2 in two objects, indicating a large column density of O$^{2+}$ and
thus probably optical thick gas. This also requires a very large ionization
parameter and relatively soft ionizing spectral energy distribution (e.g.
blackbody with $T < 5\times 10^4$ K). Our observations can be explained as
echoing of a strong ultraviolet to soft X-ray flare caused by tidal disruption
events, on molecular clouds in the inner parsecs of the galactic nuclei.
Re-analyzing the SDSS spectra reveals double-peaked or strongly blue-shouldered
broad lines in three of the objects, which disappeared in the MMT spectra in
two objects, and faded by a factor of ten in 8 years in the remaining object
with a decrease in both the line width and centroid offset. We interpret these
broad lines as arising from decelerating biconical outflows. Our results
demonstrate that the signatures of echoing can persist for as long as ten
years, and can be used to probe the gas environment in the quiescent galactic
nuclei.


title: Apolarity and direct sum decomposability of polynomials

abstract:
  A polynomial is a direct sum if it can be written as a sum of two non-zero
polynomials in some distinct sets of variables, up to a linear change of
variables. We analyze criteria for a homogeneous polynomial to be decomposable
as a direct sum, in terms of the apolar ideal of the polynomial. We prove that
the apolar ideal of a polynomial of degree $d$ strictly depending on all
variables has a minimal generator of degree $d$ if and only if it is a limit of
direct sums.


title:
Sur la compl\'etude de certaines vari\'et\'es pseudo-riemanniennes
  localement sym\'etriques

abstract:
  We prove that some symetric semi-riemannian manifolds do not admit a proper
domain which is divisible by the action of a discrete group of isometries. In
other words, if a closed semi-riemannian manifold is locally isometric to such
a model, and if its developing map is injective, then the manifold is actually
geodesically complete, and therefore isometric to a quotient of the whole model
space. Those results extend, under additional hypothesis (the injectivity of
the developing map), the theorems of Carriere and Klingler stating that closed
lorentz manifolds of constant curvature are geodesically complete.


title: MHD Shock-Clump Evolution with Self-Contained Magnetic Fields

abstract:
  We study the interaction of strong shock waves with magnetized clumps.
Previous numerical work focused on the simplified scenario in which shocked
clumps are immersed in a globally uniform magnetic field that extends through
both the clump and the ambient medium. Here we consider the complementary
circumstance in which the field is completely self-contained within the clumps.
This could arise naturally during clump formation via dynamical or thermal
instabilities for example as magnetic field pinches off from the ambient
medium. Using our AMR MHD code AstroBEAR, we carry out a series of simulations
with magnetized clumps that have different self-contained magnetic field
configurations. We find that the clump and magnetic evolution are sensitive to
the fraction of magnetic field aligned with versus perpendicular to the shock
normal. The relative strength of magnetic pressure and tension in the different
field configurations allows us to analytically understand the different cases
of post-shock evolution. We also show how turbulence and the mixing it implies
depends of the initial field configuration and suggest ways in which observed
shock-clump morphology may be used as a proxy for identifying internal field
topologies a posteriori.


title: Properties of Magnetic Neutral Line Gradients and Formation of Filaments

abstract:
  We investigate gradient of magnetic field across neutral lines (NLs), and
compare their properties for NLs with and without the chromospheric filaments.
Our results show that there is a range of preferred magnetic field gradients
where the filament formation is enhanced. On the other hand, a horizontal
gradient of magnetic field across a NL alone does not appear to be a single
factor that determines if a filament will form (or not) in a given location.


title:
Quantum simulations of a particle in one-dimensional potentials using
  NMR

abstract:
  A classical computer simulating Schrodinger dynamics of a quantum system
requires resources which scale exponentially with the size of the system, and
is regarded as inefficient for such purposes. However, a quantum computer made
up of a controllable set of quantum particles has the potential to efficiently
simulate other quantum systems of matching dimensions. In this work we studied
quantum simulations of single particle Schrodinger equation for certain
one-dimensional potentials. In particular, we report the following cases: (i)
spreading of wave-function of a free-particle, (ii) evolution of a particle in
a potential-well, and (iii) reflection of a particle from a potential-barrier.
Using a five-qubit NMR system, we achieve space discretization with four
qubits, and the other qubit is used for preparation of initial states as well
as measurement of spatial probabilities. The experimental relative
probabilities compare favorably with the theoretical values, thus effectively
mimicking a small-scale quantum simulator.