title:
Stochastic Block Mirror Descent Methods for Nonsmooth and Stochastic
  Optimization

abstract:
  In this paper, we present a new stochastic algorithm, namely the stochastic
block mirror descent (SBMD) method for solving large-scale nonsmooth and
stochastic optimization problems. The basic idea of this algorithm is to
incorporate the block-coordinate decomposition and an incremental block
averaging scheme into the classic (stochastic) mirror-descent method, in order
to significantly reduce the cost per iteration of the latter algorithm. We
establish the rate of convergence of the SBMD method along with its associated
large-deviation results for solving general nonsmooth and stochastic
optimization problems. We also introduce different variants of this method and
establish their rate of convergence for solving strongly convex, smooth, and
composite optimization problems, as well as certain nonconvex optimization
problems. To the best of our knowledge, all these developments related to the
SBMD methods are new in the stochastic optimization literature. Moreover, some
of our results also seem to be new for block coordinate descent methods for
deterministic optimization.


title:
A Search Algorithm to Find Multiple Sets of One Dimensional Unipolar
  (Optical) Orthogonal Codes with Same Code-length and Low Weight

abstract:
  This paper describes a search algorithm to find multiple sets of one
dimensional unipolar (optical) orthogonal codes characterized by parameters,
binary code sequence of length (n bits) and weight w (number of bit 1s in the
sequence) as well as auto-correlation and cross-correlation constraint
respectively for the codes within a set. For a given code length n and code
weight w all possible difference sets, with auto-correlation constraints lying
from 1 to w-1 can be designed with distinct code serial number. For given
cross-correlation constraint from 1 to w-1 Multiple sets can be searched out of
the codes with auto-correlation constraints less than or equal to given
auto-correlation constraint using proposed algorithm. The searched multiple
sets can be sorted as having number of codes not less than the upper bound of
the sets given by Johnson bound. These one dimensional unipolar orthogonal
codes have their application in incoherent optical code division multiple
access systems.


title: Linearly Convergent First-Order Algorithms for Semi-definite Programming

abstract:
  In this paper, we consider two formulations for Linear Matrix Inequalities
(LMIs) under Slater type constraint qualification assumption, namely, SDP
smooth and non-smooth formulations. We also propose two first-order linearly
convergent algorithms for solving these formulations. Moreover, we introduce a
bundle-level method which converges linearly uniformly for both smooth and
non-smooth problems and does not require any smoothness information. The
convergence properties of these algorithms are also discussed. Finally, we
consider a special case of LMIs, linear system of inequalities, and show that a
linearly convergent algorithm can be obtained under a weaker assumption.


title: Physico-mathematical foundations of relativistic cosmology

abstract:
  I briefly present the foundations of relativistic cosmology, which are,
General Relativity Theory and the Cosmological Principle. I discuss some
relativistic models, namely, "Einstein static universe" and "Friedmann
universes". The classical bibliographic references for the relevant tensorial
demonstrations are indicated whenever necessary, although the calculations
themselves are not shown.


title: Characteristics of scalar dispersion in turbulent-channel flow

abstract:
  The dispersion of a passive scalar by wall turbulence, in the limit of
infinite Peclet number, is analyzed using frozen velocity fields from the DNS
by our group. The Lagrangian trajectories of fluid particles in those fields
are integrated and used to compute the first and second-order moments of the
distribution of fluid-particle displacements. It is shown that the largest
scales in the flow dominate turbulent diffusion, and the computed dispersions
are in good agreement with measurements in the atmospheric boundary layer. This
agreement can be understood noting that the life times of the large strucutures
are much longer than the time scale of the transition from linear to Gaussian
particle spreading in the cross-stream plane. Numerical experiments performed
computing the Lagrangian trajectories in reference frames moving at different
velocities suggest that this transition is controlled by the difference between
the mean streamwise velocity and the phase speed of the large-scale structures
of the cross-stream velocities. In the streamwise direction, the effect of the
mean shear dominates and produces elongated scalar patches, with dispersion
exponents which are different from the transverse ones.


title:
Design of Two Dimensional Unipolar (Optical) Orthogonal Codes Through
  One Dimensional Unipolar (Optical) Orthogonal Codes

abstract:
  In this paper, an algorithm for construction of multiple sets of two
dimensional (2D) or matrix unipolar (optical) orthogonal codes has been
proposed. Representations of these 2D codes in difference of positions
representation (DoPR) have also been discussed along-with conventional weighted
positions representation (WPR) of the code. This paper also proposes less
complex methods for calculation of auto-correlation as well as
cross-correlation constraints within set of matrix codes. The multiple sets of
matrix codes provide flexibility for selection of optical orthogonal codes set
in wavelength-hopping time-spreading (WHTS) optical code division multiple
access (CDMA) system.


title: Tree tensor networks and entanglement spectra

abstract:
  A tree tensor network variational method is proposed to simulate quantum
many-body systems with global symmetries where the optimization is reduced to
individual charge configurations. A computational scheme is presented, how to
extract the entanglement spectra in a bipartite splitting of a loopless tensor
network across multiple links of the network, by constructing a matrix product
operator for the reduced density operator and simulating its eigenstates. The
entanglement spectra of 2 x L, 3 x L and 4 x L with either open or periodic
boundary conditions on the rungs are studied using the presented methods, where
it is found that the entanglement spectrum depends not only on the subsystem
but also on the boundaries between the subsystems.


title: Evaluation of disconnected quark loops for hadron structure using GPUs

abstract:
  A number of stochastic methods developed for the calculation of fermion loops
are investigated and compared, in particular with respect to their efficiency
when implemented on Graphics Processing Units (GPUs). We assess the performance
of the various methods by studying the convergence and statistical accuracy
obtained for observables that require a large number of stochastic noise
vectors, such as the isoscalar nucleon axial charge. The various methods are
also examined for the evaluation of sigma-terms where noise reduction
techniques specific to the twisted mass formulation can be utilized thus
reducing the required number of stochastic noise vectors.


title: Probing the circulation of ring-shaped Bose-Einstein condensates

abstract:
  This paper reports the results of a theoretical and experimental study of how
the initial circulation of ring-shaped Bose-Einstein condensates (BECs) can be
probed by time-of-flight (TOF) images. We have studied theoretically the
dynamics of a BEC after release from a toroidal trap potential by solving the
3D Gross-Pitaevskii (GP) equation. The trap and condensate characteristics
matched those of a recent experiment. The circulation, experimentally imparted
to the condensate by stirring, was simulated theoretically by imprinting a
linear azimuthal phase on the initial condensate wave function. The theoretical
TOF images were in good agreement with the experimental data. We find that upon
release the dynamics of the ring--shaped condensate proceeds in two distinct
phases. First, the condensate expands rapidly inward, filling in the initial
hole until it reaches a minimum radius that depends on the initial circulation.
In the second phase, the density at the inner radius increases to a maximum
after which the hole radius begins slowly to expand. During this second phase a
series of concentric rings appears due to the interference of ingoing and
outgoing matter waves from the inner radius. The results of the GP equation
predict that the hole area is a quadratic function of the initial circulation
when the condensate is released directly from the trap in which it was stirred
and is a linear function of the circulation if the trap is relaxed before
release. These scalings matched the data. Thus, hole size after TOF can be used
as a reliable probe of initial condensate circulation. This connection between
circulation and hole size after TOF will facilitate future studies of
atomtronic systems that are implemented in ultracold quantum gases.


title:
Quark matter under strong magnetic fields in SU(2) NJL-type models:
  parameter dependence of the cold dense matter phase diagram

abstract:
  The phase structure of magnetized cold quark matter is analyzed in the
framework of the two-flavor Nambu-Jona-Lasinio models paying special attention
to its dependence on the model parameters as different values within the
phenomenological allowed range are considered. We first discuss the simpler
chiral limit case, and then the more realistic situation of finite current
masses. We show that in spite of the difference in the nature of some
transitions, both cases are alike and exhibit a rather rich phase structure for
a significant range of acceptable parameters. A simplification of the phase
structure is obtained as parameters leading to larger values of the dressed
quark mass in the vacuum are considered. Finally, we consider the so-called
"inverse catalysis effect" showing that in some phases it implies an actual
decrease of the order parameter as the magnetic field increases.


title: Intersective polynomials and Diophantine approximation, II

abstract:
  By applying Schmidt's lattice method, we prove results on simultaneous
Diophantine approximation modulo 1 for systems of polynomials in a single prime
variable provided that certain local conditions are met.


title:
Simultaneous VLBA polarimetric observations of the v={1,2} J=1-0 and
  v=1, J=2-1 SiO maser emission toward VY CMa: maser morphology and pumping

abstract:
  This paper presents a milliarcsecond-scale comparison of the polarised
component-level v=1 J=1-0, v=2 J=1-0 and v=1 J=2-1 SiO maser emission toward
the supergiant star VY CMa. These observations used the VLBA at {\lambda}=7mm
and {\lambda}=3mm over two epochs. The goal is to use the relative
characteristics and spatial distribution of the transitions in individual
resolved maser components to provide observational constraints on SiO maser
excitation and pumping models. We find that many v=1 J=1-0 and v=2 J=1-0
features overlap in the second observing epoch, at comparable sensitivity. The
v=2 J=1-0 emission is primarily located within several v=1 J=1-0 regions, and
has a high degree of morphological similarity in the northeastern envelope,
supportive of local collisional pumping. We find significantly higher spatial
overlap between v=1 J=1-0 and J=2-1 features than generally previously
reported. However, the overlapping v=1 J=2-1 emission is usually weaker than
predicted by hydrodynamical models, possibly due to low-density collisional
pumping. The overall maser morphology contains several large-scale features
that are persistent over multiple years and are likely associated with
intrinsic physical circumstellar conditions. Our data cannot distinguish
between competing near-circumstellar bulk kinematic models but do provide
evidence for localized inhomogeneous mass-loss.


title:
Optical analogue of spontaneous symmetry breaking induced by tachyon
  condensation in amplifying plasmonic arrays

abstract:
  We study analytically and numerically an optical analogue of tachyon
condensation in amplifying plasmonic arrays. Optical propagation is modeled
through coupled-mode equations, which in the continuous limit can be converted
into a nonlinear one-dimensional Dirac-like equation for fermionic particles
with imaginary mass, i.e. fermionic tachyons. We demonstrate that the vacuum
state is unstable and acquires an expectation value with broken chiral
symmetry, corresponding to the homogeneous nonlinear stationary solution of the
system. The quantum field theory analogue of this process is the condensation
of unstable fermionic tachyons into massive particles. This paves the way for
using amplifying plasmonic arrays as a classical laboratory for spontaneous
symmetry breaking effects in quantum field theory.


title: Shaping thin nematic films with competing boundary conditions

abstract:
  Free interfaces of liquid crystals tend to minimise both capillarity and
anchoring forces. Here we study nematic films in planar and radial geometries
with antagonistic anchoring boundary conditions and one deformable interface.
Assuming a perturbation ansatz we study possible couplings of the director
configuration with the shape of free interfaces. In the long-wavelength limit
independent of the surface tension, we find analytically threshold thickness
when flat film becomes unstable. Next we quantify the bifurcation of a circular
ring towards structures with $m$-fold rotational symmetry, induced by elastic
anisotropy of nematic director in the bulk. We believe that our simplified
approach can give additional insight into elastic and capillary phenomena of
materials with inherent liquid crystalline order and free interfaces.


title: On subvarieties with ample normal bundle

abstract:
  We show that a pseudoeffective R-divisor has numerical dimension 0 if it is
numerically trivial on a subvariety with ample normal bundle. This implies that
the cycle class of a curve with ample normal bundle is big, giving an
affirmative answer to a question of Peternell. We also give other positivity
properties such subvarieties.


title: Cohomology jump loci of differential graded Lie algebras

abstract:
  To study infinitesimal deformation problems with cohomology constraints, we
introduce and study cohomology jump functors for differential graded Lie
algebra (DGLA) pairs. We apply this to local systems, vector bundles, Higgs
bundles, and representations of fundamental groups. The results obtained
describe the analytic germs of the cohomology jump loci inside the
corresponding moduli space, extending previous results of Goldman-Millson,
Green-Lazarsfeld, Nadel, Simpson, Dimca-Papadima, and of the second author.


title:
Interference of macroscopic beams on a beam splitter: phase uncertainty
  converted into photon-number uncertainty

abstract:
  Squeezed-vacuum twin beams, commonly generated through parametric
down-conversion, are known to have perfect photon-number correlations.
According to the Heisenberg principle, this is accompanied by a huge
uncertainty in their relative phase. By overlapping bright twin beams on a beam
splitter, we convert phase fluctuations into photon-number fluctuations and
observe this uncertainty as a typical `U-shape' of the output photon-number
distribution. This effect, although reported for atomic ensembles and giving
hope for phase super-resolution, has been never observed for light beams. The
shape of the normalized photon-number difference distribution is similar to the
one that would be observed for high-order Fock states. It can be also mimicked
by classical beams with artificially mixed phase, but without any perspective
for phase super-resolution. The probability distribution at the beam splitter
output can be used for filtering macroscopic superpositions at the input.


title: A simple proof of the tree-width duality theorem

abstract:
  We give a simple proof of the "tree-width duality theorem" of Seymour and
Thomas that the tree-width of a finite graph is exactly one less than the
largest order of its brambles.


title:
Analytical solution of the $\mu(I)-$rheology for fully developed
  granular flows in simple configurations

abstract:
  Using the $\mu(I)$ continuum model recently proposed for dense granular
flows, we study theoretically steady and fully developed granular flows in two
configurations: a plane shear cell and a channel made of two parallel plates
(Poiseuille configuration). In such a description, the granular medium behaves
like a fluid whose viscosity is a function of the inertia. In the shear plane
geometry our calculation predicts that the height of the shear bands scales
with $U_0^{1/4}P_0^{1/2}$, where $U_0$ is the velocity of the moving plate and
$P_0$ the pressure applied at its top. In the Poiseuille configuration, the
medium is sheared between the lateral boundaries and a plug flow is located in
the center of the channel. The size of the plug flow is found to increase for a
decreasing pressure gradient. We show that, for small pressure gradient, the
granular material behaves like a Bingham plastic fluid.


title:
On the Ginzburg--Landau Functional in the Surface Superconductivity
  Regime

abstract:
  We present new estimates on the two-dimensional Ginzburg-Landau energy of a
type-II superconductor in an applied magnetic field varying between the second
and third critical fields. In this regime, superconductivity is restricted to a
thin layer along the boundary of the sample. We provide new energy lower
bounds, proving that the Ginzburg-Landau energy is determined to leading order
by the minimization of a simplified 1D functional in the direction
perpendicular to the boundary. Estimates relating the density of the
Ginzburg-Landau order parameter to that of the 1D problem follow. In the
particular case of a disc sample, a refinement of our method leads to a
pointwise estimate on the Ginzburg-Landau order parameter, thereby proving a
strong form of uniformity of the surface superconductivity layer, related to a
conjecture by Xing-Bin Pan.

categories: math-ph cond-mat.supr-con math.AP math.MP


title:
Spin glasses, the quantum annealing, colloidal glasses and crystals:
  exploring complex free-energy landscapes

abstract:
  Glassy behavior is one of the main open problems in condensed matter physics.
In this thesis, we approach the problem by studying spin-glasses and colloids,
using several complementary strategies. From the point of view of model
building, we propose a new model, the hypercube model, which is mean-field but
defined in a metric space. We show that, also in Mean Field, the spin-glass
non-equilibrium dynamics is a domain-growth process very similar to its
three-dimensional counterpart. We also consider spin-glasses in three spatial
dimensions, focusing on temperature chaos. Thanks to the low-temperature
configurations equilibrated with Janus, we show that temperature chaos can be
aptly described through a large-deviations functional. The finite-size scaling
behavior can be predicted in details from this functional, including the
pre-asymptotic regime where chaos is driven by rare events. We also address the
problem of finding new, efficient algorithms to study glassy systems. In
particular, in the context of the Quantum-Adiabatic algorithm we discuss
strategies for bypassing the "first-order bottleneck". Our approach is
successfully put to work on the p-spin ferromagnetic model. We also show how to
use tethered Monte Carlo (a recent refinement of Umbrella Sampling) to handle
problems with more than one order parameter, such as hard-spheres
crystallization. We study the crystallization transition equilibrating the
largest systems to date, and obtaining very accurate determinations of the
coexistence pressure and the interfacial free-energy. We also show our efforts
to characterize the solid phase in a system of soft spheres at very high
polydispersity.


title: Occupy magnetogenesis

abstract:
  The occupation number of a field is a sound discriminator between classical
and quantum regimes. In this pamphlet we give an overview of what we can learn
about inflationary magnetogenesis just by looking at the occupation numbers of
the classical magnetic fields observed today, and those of the quantum
electromagnetic field during inflation. The sole occupation number behaviour
dictates that for a pure Maxwell theory in de Sitter space it appears
impossible to match the two epochs.


title: Mutually Unbiased Bases and Bound Entanglement

abstract:
  In this contribution we relate two different key concepts: mutually unbiased
bases (MUBs) and entanglement; in particular we focus on bound entanglement,
i.e. highly mixed states which cannot be distilled by local operations and
classical communications. For a certain class of states --for which the
state-space forms a "magic" simplex-- we analyze the set of bound entangled
states detected by the MUB criterion for different dimensions d and number of
particles n. We find that the geometry is similar for different d and n,
consequently, the MUB criterion opens possibilities to investigate the
typicality of PPT-bound and multipartite bound entanglement deeper and provides
a simple experimentally feasible tool to detect bound entanglement.


title: Relation between the autocorrelation and Wigner functions

abstract:
  We show a simple mechanism to measure the Wigner function of a harmonic
oscillator. For this system we also show that autocorrelation and Wigner
functions are equivalent.


title:
A Russo Seymour Welsh Theorem for critical site percolation on
  \(\mathbb{Z}^2\)

abstract:
  The Russo-Seymour-Welsh Theorem for Z^2 bond or T (triangular lattice) site
percolation states that at criticality, for all fixed real {\lambda}, the
probability of the existence of a horizontal occupied crossing of each
rectangle with size n*{\lambda}n is not degenerated when n tends to infinity.
Turning to site percolation on Z^2, where the self duality does not hold
anymore, we prove that the analogue statement of the RSW Theorem will still be
true in this case. The proof uses appropriate finite size criteria and a result
of Kesten which allows us to extend existing crossings without losing too much
probability. As a consequence, there is no infinite cluster at criticalty. Our
object in this short paper is twofold. Our first goal is to give a proof of a
RSW Theorem for Z 2 site percolation. Since the proof uses in an essential way
a celebrated result by Kesten on the so called "box crossing", our second goal
in this paper is to present a self-contained proof of this theorem in perhaps a
more accessible language.


title: The Entropy Law and the impossibility of perpetual economic growth

abstract:
  Every production-recycling iteration accumulates an inevitable proportion of
its matter-energy in the environment, lest the production process itself would
be a system in perpetual motion, violating the second law of Thermodynamics.
Such high-entropy matter depletes finite stocks of ecosystem services provided
by the ecosphere, hence are incompatible with the long-term growth in the
material scale of the economic process. Moreover, the complex natural systems
governing such stocks respond to depletion by possibly sudden environmental
transitions, thus hindering markets' very ability to adapt to the new
equilibrium conditions. Consequently, uncertainty of critical resilience
thresholds constrains material economic growth.


title:
On the (adjacency) metric dimension of corona and strong product graphs
  and their local variants: combinatorial and computational results

abstract:
  The metric dimension is quite a well-studied graph parameter. Recently, the
adjacency metric dimension and the local metric dimension have been introduced.
We combine these variants and introduce the local adjacency metric dimension.
We show that the (local) metric dimension of the corona product of a graph of
order $n$ and some non-trivial graph $H$ equals $n$ times the (local) adjacency
metric dimension of $H$. This strong relation also enables us to infer
computational hardness results for computing the (local) metric dimension,
based on according hardness results for (local) adjacency metric dimension that
we also provide. We also study combinatorial properties of the strong product
of graphs and emphasize the role different types of twins play in determining
in particular the adjacency metric dimension of a graph.


title:
A hybrid stochastic hierarchy equations of motion approach to treat the
  low temperature dynamics of non-Markovian open quantum systems

abstract:
  The hierarchical equations of motion technique has found widespread success
as a tool to generate the numerically exact dynamics of non-Markovian open
quantum systems. However, its application to low temperature environments
remains a serious challenge due to the need for a deep hierarchy that arises
from the Matsubara expansion of the bath correlation function. Here we present
a hybrid stochastic hierarchical equation of motion (sHEOM) approach that
alleviates this bottleneck and leads to a numerical cost that is nearly
independent of temperature. Additionally, the sHEOM method generally converges
with fewer hierarchy tiers allowing for the treatment of larger systems.
Benchmark calculations are presented on the dynamics of two level systems at
both high and low temperatures to demonstrate the efficacy of the approach.
Then the hybrid method is used to generate the exact dynamics of systems that
are nearly impossible to treat by the standard hierarchy. First, exact energy
transfer rates are calculated across a broad range of temperatures revealing
the deviations from the Forster rates. This is followed by computations of the
entanglement dynamics in a system of two qubits at low temperature spanning the
weak to strong system-bath coupling regimes.


title:
The Angular Clustering of WISE-Selected AGN: Different Haloes for
  Obscured and Unobscured AGN

abstract:
  We calculate the angular correlation function for a sample of 170,000 AGN
extracted from the Wide-field Infrared Survey Explorer (WISE) catalog, selected
to have red mid-IR colors (W1 - W2 > 0.8) and 4.6 micron flux densities
brighter than 0.14 mJy). The sample is expected to be >90% reliable at
identifying AGN, and to have a mean redshift of z=1.1. In total, the angular
clustering of WISE-AGN is roughly similar to that of optical AGN. We
cross-match these objects with the photometric SDSS catalog and distinguish
obscured sources with (r - W2) > 6 from bluer, unobscured AGN. Obscured sources
present a higher clustering signal than unobscured sources. Since the host
galaxy morphologies of obscured AGN are not typical red sequence elliptical
galaxies and show disks in many cases, it is unlikely that the increased
clustering strength of the obscured population is driven by a host galaxy
segregation bias. By using relatively complete redshift distributions from the
COSMOS survey, we find obscured sources at mean redshift z=0.9 have a bias of b
= 2.9 \pm 0.6 and are hosted in dark matter halos with a typical mass of
log(M/M_odot)~13.5. In contrast, unobscured AGN at z~1.1 have a bias of b = 1.6
\pm 0.6 and inhabit halos of log(M/M_odot)~12.4. These findings suggest that
obscured AGN inhabit denser environments than unobscured AGN, and are difficult
to reconcile with the simplest AGN unification models, where obscuration is
driven solely by orientation.


title: Zooming in on the Formation of Protoplanetary Disks

abstract:
  We use the adaptive mesh refinement code RAMSES to model the formation of
protoplanetary disks in realistic star formation environments. The resolution
scales over up to 29 powers of two ($\sim$ 9 orders of magnitude) covering a
range from outer scales of 40 pc to inner scales of 0.015 AU. The accretion
rate from a 1.5 solar mass envelope peaks near $10^{-4}$ $\mspy$ about 6 kyr
after sink particle formation and then decays approximately exponentially,
reaching $10^{-6}$ $\mspy$ in 100 kyr. The models suggest universal scalings of
physical properties with radius during the main accretion phase, with kinetic
and / or magnetic energy in approximate balance with gravitational energy.
Efficient accretion is made possible by the braking action of the magnetic
field, which nevertheless allows a near-Keplerian disk to grow to a 100 AU
size. The magnetic field strength ranges from more than 10 G at 0.1 AU to less
than 1 mG at 100 AU, and drives a time dependent bipolar outflow, with a
collimated jet and a broader disk wind.


title:
Characterization of R-134A superheated droplet detector for neutron
  detection

abstract:
  R-134a (C2H2F4) is a low cost, easily available and chlorine free
refrigerant, which in its superheated state can be used as an efficient neutron
detector. Due to its high solubility in water the R-134a based superheated
droplet detectors (SDD) are usually very unstable unless the detector is
fabricated using a suitable additive, which stabilizes the detector. The SDD is
known to have superheated droplets distributed in a short-lived and in a
relatively longer-lived metastable states. We have studied the detector
response to neutrons using a 241AmBe neutron source and obtained the
temperature variation of the nucleation parameters and the interstate kinetics
of these droplets using a two-state model.


title:
The Most Luminous z~9-10 Galaxy Candidates yet Found: The Luminosity
  Function, Cosmic Star-Formation Rate, and the First Mass Density Estimate at
  500 Myr

abstract:
  [abridged] We present the discovery of four surprisingly bright (H_160 ~ 26 -
27 mag AB) galaxy candidates at z~9-10 in the complete HST CANDELS WFC3/IR
GOODS-N imaging data, doubling the number of z~10 galaxy candidates that are
known, just ~500 Myr after the Big Bang. Two similarly bright sources are also
detected in a systematic re-analysis of the GOODS-S data set. Three of the four
galaxies in GOODS-N are significantly detected at 4.5-6.2sigma in the very deep
Spitzer/IRAC 4.5 micron data, as is one of the GOODS-S candidates. Furthermore,
the brightest of our candidates (at z=10.2+-0.4) is robustly detected also at
3.6 micron (6.9sigma), revealing a flat UV spectral energy distribution with a
slope beta=-2.0+-0.2, consistent with demonstrated trends with luminosity at
high redshift. The abundance of such luminous candidates suggests that the
luminosity function evolves more significantly in phi_* than in L_* at z>~8
with a higher number density of bright sources than previously expected.
Despite the discovery of these luminous candidates, the cosmic star formation
rate density for galaxies with SFR >0.7 M_sun/yr shows an order-of-magnitude
increase in only 170 Myr from z ~ 10 to z ~ 8, consistent with previous
results. Based on the IRAC detections, we derive galaxy stellar masses at z~10,
finding that these luminous objects are typically 10^9 M_sun. The cosmic
stellar mass density at z~10 is log10 rho_* = 4.7^+0.5_-0.8 M_sun Mpc^-3 for
galaxies brighter than M_UV~-18. The remarkable brightness, and hence
luminosity, of these z~9-10 candidates highlights the opportunity for deep
spectroscopy to determine their redshift and nature, demonstrates the value of
additional search fields covering a wider area to understand star-formation in
the very early universe, and highlights the opportunities for JWST to map the
buildup of galaxies at redshifts much earlier than z~10.


title: On the Quantum-To-Classical Transition for Ekpyrotic Perturbations

abstract:
  We examine the processes of quantum squeezing and decoherence of density
perturbations produced during a slowly contracting ekpyrotic phase in which
entropic perturbations are converted to curvature perturbations before the
bounce to an expanding phase. During the generation phase, the entropic
fluctuations evolve into a highly squeezed quantum state, analogous to the
evolution of inflationary perturbations. Subsequently, during the conversion
phase, quantum coherence is lost very efficiently due to the interactions of
entropy and adiabatic modes. Moreover, while decoherence occurs, the adiabatic
curvature perturbations inherit their semi-classicality from the entropic
perturbations. Our results confirm that, just as for inflation, an ekpyrotic
phase can generate nearly scale-invariant curvature perturbations which may be
treated as a statistical ensemble of classical density perturbations, in
agreement with observations of the cosmic background radiation.


title: The Properties and Fate of the Galactic Center G2 Cloud

abstract:
  The object G2 was recently discovered descending into the gravitational
potential of the supermassive black hole (BH) Sgr A*. We test the photoionized
cloud scenario, determine the cloud properties, and estimate the emission
during the pericenter passage. The incident radiation is computed starting from
the individual stars at the locations of G2. The radiative transfer
calculations are conducted with CLOUDY code and $2011$ broadband and line
luminosities are fitted. The spherically symmetric, tidally distorted, and
magnetically arrested cloud shapes are tested with both the interstellar medium
dust and $10$~nm graphite dust. The best-fitting magnetically arrested model
has the initial density $n_{\rm init}=1.8\times10^5{\rm cm}^{-3}$, initial
radius $R_{\rm init}=2.2\times10^{15}{\rm cm}=17 {\rm mas}$, mass $m_{\rm
cloud}=4M_{\rm Earth}$, and dust relative abundance $A=0.072$. It provides a
good fit to $2011$ data, is consistent with the luminosities in $2004$ and
$2008$, and reaches an agreement with the observed size. We revise down the
predicted radio and X-ray bow shock luminosities to be below the quiescent
level of Sgr A*, which readily leads to non-detection in agreement to
observations. The magnetic energy dissipation in the cloud at the pericenter
coupled with more powerful irradiation may lead to an infrared source with an
apparent magnitude $m_{L'}\approx13.0$. No shock into the cloud and no X-rays
are expected from cloud squeezing by the ambient gas pressure. Larger than
previously estimated cloud mass $m_{\rm cloud}=(4-20)M_{\rm Earth}$ may produce
a higher accretion rate and a brighter state of Sgr A* as the debris descend
onto the BH.


title:
Statistical properties of mass, star formation, chemical content and
  rotational patterns in early z > 9 structures

abstract:
  We study the baryonic, chemical and dynamical properties of a significantly
large sample of early proto-galaxies in the first 500 Myr of the Universe
(redshift z>9), obtained from high-resolution numerical, N-body,
hydrodynamical, chemistry simulations including atomic and molecular networks,
gas cooling, star formation, stellar evolution and metal spreading for
population III and population II-I regimes according to proper stellar yields
and lifetimes. We find that first star formation events take place in halos
with dark-matter mass M_{DM} > 2\times 10^6 M_{sun}. Early star forming objects
have: molecular fractions from x_{mol} < 10^{-4} in quiescent structures up to
x_{mol} > 0.1 in active regions; star formation rates SFR
~10^{-8}-10^{-3}M_{sun}/yr; and metallicities in the range
~10^{-8}-10^{-2}Z_{sun}. Roughly ~10% of high-z haloes host population II-I
star formation and dominate the cosmic SFR density. They usually are bursty
objects with mean specific SFR around ~10 Gyr^{-1} at z~9 and increasing with
redshift up to ~10^2 Gyr^{-1}. Stellar feedback effects alter the baryonic
content of the haloes and locally affect their chemical and thermo-dynamical
properties, as reflected by the broadening of various physical relations. The
establishment of gaseous rotationally-supported cores is quite uncommon, weakly
related to the large-scale dark-matter behaviour and evolving in an
intermittent fashion. The colder, molecular-rich phase tends to maintain any
established rotational motion longer with respect to the hotter, metal-rich
component, which is very sensitive to environmental processes. While the
fraction of haloes featuring a significant amount of co-rotating,
molecular-rich gas increases with cosmic time (from a few percent at z~20 up to
~5-15% at z~9), the chaotic nature of metal-enriched material does not lead to
particular trends.


title:
Dual Supermassive Black Hole Candidates in the AGN and Galaxy Evolution
  Survey

abstract:
  Dual supermassive black holes (SMBHs) with kiloparsec scale separations in
merger-remnant galaxies are informative tracers of galaxy evolution, but the
avenue for identifying them in large numbers for such studies is not yet clear.
One promising approach is to target spectroscopic signatures of systems where
both SMBHs are fueled as dual active galactic nuclei (AGNs), or where one SMBH
is fueled as an offset AGN. Dual AGNs may produce double-peaked narrow AGN
emission lines, while offset AGNs may produce single-peaked narrow AGN emission
lines with line-of-sight velocity offsets relative to the host galaxy. We
search for such dual and offset systems among 173 Type 2 AGNs at z<0.37 in the
AGN and Galaxy Evolution Survey (AGES), and we find two double-peaked AGNs and
five offset AGN candidates. When we compare these results to a similar search
of the DEEP2 Galaxy Redshift Survey and match the two samples in color,
absolute magnitude, and minimum velocity offset, we find that the fraction of
AGNs that are dual SMBH candidates increases from z=0.25 to z=0.7 by a factor
of ~6 (from 2/70 to 16/91, or 2.9% to 18%). This may be associated with the
rise in the galaxy merger fraction over the same cosmic time. As further
evidence for a link with galaxy mergers, the AGES offset and dual AGN
candidates are tentatively ~3 times more likely than the overall AGN population
to reside in a host galaxy that has a companion galaxy (from 16/173 to 2/7, or
9% to 29%). Follow-up observations of the seven offset and dual AGN candidates
in AGES will definitively distinguish velocity offsets produced by dual SMBHs
from those produced by narrow-line region kinematics, and will help sharpen our
observational approach to detecting dual SMBHs.


title:
The effect of aberration on partial-sky measurements of the cosmic
  microwave background temperature power spectrum

abstract:
  Our motion relative to the cosmic-microwave-background (CMB) rest frame
deflects light rays giving rise to shifts as large as L -> L(1+beta), where
beta=0.00123 is our velocity (in units of the speed of light) on measurements
CMB fluctuations. Here we present a novel harmonic-space approach to this CMB
aberration that improves upon prior work by allowing us to (i) go to higher
orders in beta, thus extending the validity of the analysis to measurements at
L > 1/beta ~ 800; and (ii) treat the effects of window functions and
pixelization in a more accurate and computationally efficient manner. We
calculate precisely the magnitude of the systematic bias in the power spectrum
inferred from the partial sky, and show that aberration shifts the multipole
moment by Delta L/L ~ beta<cos(theta)>, with <cos(theta)> averaged over the
survey footprint. Such a shift, if ignored, would bias the measurement of the
sound-horizon size theta_* at the 0.01%-level, which is comparable to the
measurement uncertainties of Planck. The bias can then propagate into
cosmological parameters such as the angular-diameter distance, Hubble parameter
and dark-energy equation of state. We study the effect of aberration for
current Planck, South Pole Telescope (SPT) and Atacama Cosmology Telescope
(ACT) data and show that the bias cannot be neglected. We suggest that the
small tension between Planck, ACT, and SPT may be due partially to aberration.
An Appendix shows how the near constancy of the full-sky power spectrum under
aberration follows from unitarity of the aberration kernel.


title: The discontinuities of conformal transitions and mass spectra of V-QCD

abstract:
  Zero temperature spectra of mesons and glueballs are analyzed in a class of
holographic bottom-up models for QCD in the Veneziano limit, N_c -> infinity,
N_f -> infinity, with x = N_f/N_c fixed (V-QCD). The backreaction of flavor on
color is fully included. It is found that spectra are discrete and gapped
(modulo the pions) in the QCD regime, for x below the critical value x_c where
the conformal transition takes place. The masses uniformly converge to zero in
the walking region x -> x_c^- due to Miransky scaling. All the ratios of masses
asymptote to non-zero constants as x -> x_c^- and therefore there is no
"dilaton" in the spectrum. The S-parameter is computed and found to be of O(1)
in units of N_f N_c in the walking regime, while it is always an increasing
function of x. This indicates the presence of a subtle discontinuity of
correlation functions across the conformal transition at x = x_c.


title: F-Theory on Spin(7) Manifolds: Weak-Coupling Limit

abstract:
  F-theory on appropriately fibered Spin(7) holonomy manifolds is defined to
arise as the dual of M-theory on the same space in the limit of a shrinking
fiber. A class of Spin(7) orbifolds can be constructed as quotients of
elliptically fibered Calabi-Yau fourfolds by an anti-holomorphic involution.
The F-theory dual then exhibits one macroscopic dimension that has the topology
of an interval. In this work we study the weak-coupling limit of a subclass of
such constructions and identify the objects that arise in this limit. On the
Type IIB side we find space-time filling O7-planes as well as O5-planes and
orbifold five-planes with a (-1)^{F_L} factor localised on the interval
boundaries. These orbifold planes are referred to as X5-planes and are S-dual
to a D5-O5 system. For other involutions exotic O3-planes and X3-planes on top
of a six-dimensional orbifold singularity can appear. We show that the objects
present preserve a mutual supersymmetry of four supercharges in the bulk of the
interval and two supercharges on the boundary. It follows that in the
infinite-interval and weak-coupling limit full four-dimensional N=1
supersymmetry is restored, which on the Type IIA side corresponds to an
enhancement of supersymmetry by winding modes in the vanishing interval limit.


title: Will Comet ISON (C/2012 S1) Survive Perihelion?

abstract:
  On 2013 November 28 Comet ISON (C/2012 S1) will pass by the Sun with a
perihelion distance of 2.7 solar radii. Understanding the possible outcomes for
the comet's response to such a close passage by the Sun is important for
planning observational campaigns and for inferring ISON's physical properties.
We present new numerical simulations and interpret them in context with the
historical track record of comet disruptions and of sungrazing comet behavior.
Historical data suggest that sizes below ~200 m are susceptible to destruction
by sublimation driven mass loss, while we find that for ISON's perihelion
distance, densities lower than 0.1 g cm^-3 are required to tidally disrupt a
retrograde or non-spinning body. Such low densities are substantially below the
range of the best-determined comet nucleus densities, though dynamically new
comets such as ISON have few measurements of physical properties. Disruption
may occur for prograde rotation at densities up to 0.7 g cm^-3, with the
chances of disruption increasing for lower density, faster prograde rotation,
and increasing elongation of the nucleus. Given current constraints on ISON's
nucleus properties and the typically determined values for these properties
among all comets, we find tidal disruption to be unlikely unless other factors
(e.g., spin-up via torquing) affect ISON substantially. Whether or not
disruption occurs, the largest remnant must be big enough to survive subsequent
mass loss due to sublimation in order for ISON to remain a viable comet well
after perihelion.


title:
SMACK: A New Algorithm for Modeling Collisions and Dynamics of
  Planetesimals in Debris Disks

abstract:
  We present the Superparticle Model/Algorithm for Collisions in Kuiper belts
and debris disks (SMACK), a new method for simultaneously modeling, in 3-D, the
collisional and dynamical evolution of planetesimals in a debris disk with
planets. SMACK can simulate azimuthal asymmetries and how these asymmetries
evolve over time. We show that SMACK is stable to numerical viscosity and
numerical heating over 10^7 yr, and that it can reproduce analytic models of
disk evolution. We use SMACK to model the evolution of a debris ring containing
a planet on an eccentric orbit. Differential precession creates a spiral
structure as the ring evolves, but collisions subsequently break up the spiral,
leaving a narrower eccentric ring.


title:
Observational rotation curves and density profiles vs. the Thomas-Fermi
  galaxy structure theory

abstract:
  The Thomas-Fermi approach to galaxy structure determines selfconsistently the
fermionic warm dark matter (WDM) gravitational potential given the distribution
function f(E). This framework is appropriate for macroscopic quantum systems:
neutron stars, white dwarfs and WDM galaxies. Compact dwarf galaxies follow
from the quantum degenerate regime, while dilute and large galaxies from the
classical Boltzmann regime. We find analytic scaling relations for the main
galaxy magnitudes as halo radius r_h, mass M_h and phase space density. The
observational data for a large variety of galaxies are all well reproduced by
these theoretical scaling relations. For the compact dwarfs, our results show
small deviations from the scaling due to quantum macroscopic effects. We
contrast the theoretical curves for the circular velocities and density
profiles with the observational ones. All these results are independent of any
WDM particle physics model, they only follow from the gravity interaction of
the WDM particles and their fermionic nature. The theory rotation and density
curves reproduce very well for r < r_h the observations of 10 different and
independent sets of data for galaxy masses from 5x10^9 Msun till 5x10^{11}
Msun. Our normalized circular velocity curves turn to be universal functions of
r/r_h for all galaxies and reproduce very well the observational curves for r <
r_h. Conclusion: the Thomas-Fermi approach correctly describes the galaxy
structures (Abridged).


title: Geometric Massive Gravity in Multi-Connection Framework

abstract:
  What is the right way to interpret a massive graviton? We generalize the
kinematical framework of general relativity to multiple connections. The
average of the connections is itself a connection and plays the role of the
canonical connection in standard General Relativity. At the level of dynamics,
the simplest choice of the Einstein-Hilbert action is indistinguishable from
the single-connection case. However, inspired by Weyl geometry, we show how one
can construct massive gravity to all orders in perturbation theory compatible
with the de Rham-Gabadadze-Tolley ghost-free model. We conclude that the mass
of the graviton can be interpreted as a geometrical property of spacetime
arising from two connections. Furthermore in the multi-connection framework
there is no ambiguity in the definition of physical metric and consequently
coupling to matter.


title: Infrared absorption by graphene-hBN heterostructures

abstract:
  We propose a theory of optical absorption in monolayer graphene-hexagonal
boron nitride (hBN) heterostructures. In highly oriented heterostructures, the
hBN underlay produces a long-range moir\'e superlattice potential for the
graphene electrons which modifies the selection rules for absorption of
incoming photons in the infrared to visible frequency range. The details of the
absorption spectrum modification depend on the relative strength of the various
symmetry-allowed couplings between the graphene electrons and the hBN, and the
resulting nature of the reconstructed band structure.


title: Future sensitivity to new physics in B_d, B_s and K mixings

abstract:
  We estimate, in a large class of scenarios, the sensitivity to new physics in
B_d and B_s mixings achievable with 50 ab-1 of Belle II and 50 fb-1 of LHCb
data. We find that current limits on new physics contributions in both B_{d,s}
systems can be improved by a factor of ~5 for all values of the CP violating
phases, corresponding to over a factor of 2 increase in the scale of new
physics probed. Assuming the same suppressions by CKM matrix elements as those
of the standard model box diagrams, the scale probed will be about 20 TeV for
tree-level new physics contributions, and about 2 TeV for new physics arising
at one-loop. We also explore the future sensitivity to new physics in K mixing.
Implications for generic new physics and for various specific scenarios, such
as minimal flavor violation, light third-generation dominated flavor violation,
or U(2) flavor models are studied.


title: Turbulent entrainment origin of protostellar outflows

abstract:
  Protostellar outflow is a prominent process that accompanies the formation of
stars. It is generally agreed that wide-angled protostellar outflows come from
the interaction between the wind from a forming star and the ambient gas.
However, it is still unclear how the interaction takes place. In this work, we
theoretically investigate the possibility that the outflow results from
interaction between the wind and the ambient gas in the form of turbulent
entrainment. In contrast to the previous models, turbulent motion of the
ambient gas around the protostar is taken into account. In our model, the
ram-pressure of the wind balances the turbulent ram-pressure of the ambient
gas, and the outflow consists of the ambient gas entrained by the wind. The
calculated outflow from our modelling exhibits a conical shape. The total mass
of the outflow is determined by the turbulent velocity of the envelope as well
as the outflow age, and the velocity of the outflow is several times higher
than the velocity dispersion of the ambient gas. The outflow opening angle
increases with the strength of the wind and decreases with the increasing
ambient gas turbulence. The outflow exhibits a broad line width at every
position. We propose that the turbulent entrainment process, which happens
ubiquitously in nature, plays a universal role in shaping protostellar
outflows.


title: Intensity Mapping across Cosmic Times with the Lyman-Alpha Line

abstract:
  We present a quantitative model of Lyman-alpha (Ly-alpha) emission throughout
cosmic history and determine the prospects for intensity mapping of spatial
fluctuations in the Ly-alpha signal. Since i) our model assumes at z>6 the
minimum star formation required to sustain reionization and ii) is based at z<6
on a luminosity function extrapolated from the few observed bright Ly-alpha
emitters, this should be considered a lower limit. Mapping the line emission
allows probes of reionization, star formation, and large-scale structure (LSS)
as a function of redshift. While Ly-alpha emission during reionization has been
studied, we also predict the post-reionization signal to test predictions of
the intensity and motivate future intensity mapping probes of reionization. We
include emission from massive dark matter halos and the intergalactic medium
(IGM) in our model. We find agreement with current, measured luminosity
functions of Ly-alpha emitters at z<8. However, diffuse IGM emission, not
associated with Ly-alpha emitters, dominates the intensity up to z~10. While
our model is applicable for deep-optical or near-infrared observers like the
SuMIre survey or the James Webb Space Telescope, only intensity mapping will
detect the diffuse IGM emission. We also construct a 3D power spectrum model of
the Ly\alpha emission, and characterize possible foreground contamination.
Finally, we study the prospects of an intensity mapper for measuring Ly-alpha
fluctuations while identifying interloper contamination for removal. Our
results suggest that while the reionization signal is challenging, Ly-alpha
fluctuations can be an interesting new probe of LSS at late times when used in
conjunction with other lines like, e.g., H-alpha, to monitor low-redshift
foreground confusion.


title:
Interpreting the Global 21-cm Signal from High Redshifts. I. Model
  Independent Constraints

abstract:
  The sky-averaged (global) 21-cm signal is a powerful probe of the
intergalactic medium (IGM) prior to the completion of reionization. However, it
has so far been unclear that even in the best case scenario, in which the
signal is accurately extracted from the foregrounds, that it will provide more
than crude estimates of when the Universe's first stars and black holes form.
In contrast to previous work, which has focused on predicting the 21-cm
signatures of the first luminous objects, we investigate an arbitrary
realization of the signal, and attempt to translate its features to the
physical properties of the IGM. Within a simplified global framework, the 21-cm
signal yields quantitative constraints on the Lyman-alpha background intensity,
net heat deposition, ionized fraction, and their time derivatives, without
invoking models for the astrophysical sources themselves. The 21-cm absorption
signal is most easily interpreted, setting strong limits on the heating rate
density of the Universe with a measurement of its redshift alone, independent
of the ionization history or details of the Lyman-alpha background evolution.
In a companion paper we extend these results, focusing on the confidence with
which one can infer source emissivities from IGM properties.


title: Very Light Charginos and Higgs Decays

abstract:
  We explore modifications to the loop-induced Higgs couplings h\gamma\gamma\
and h\gamma Z from light charginos in the Minimal Supersymmetric Standard
Model. When the lightest chargino mass is above the naive LEP bound of order
100 GeV the effects are modest, with deviations in the decay branching ratios
typically less than 15% from the Standard Model predictions. However, if the
charginos are lighter than 100 GeV, more dramatic alterations to these
couplings are possible as a consequence of the rise of the one loop form
factor. For example, the diphoton signal strength can be enhanced by as much as
70% compared to the Standard Model value. We scrutinize in detail the existing
LEP, Tevatron, and LHC searches and present a scenario in which a very light
chargino with a mass as light as half the Higgs mass is hidden at LEP and is
allowed by all direct collider constraints and electroweak precision tests. The
scenario has a sneutrino LSP with a macroscopic decay length of order 10-100
cm. We outline potential search strategies to test this scenario at the LHC.


title: A Complete Sample of Long Bright Swift GRBs

abstract:
  Starting from the Swift sample we define a complete sub-sample of 58 bright
long Gamma Ray Bursts (GRB), 55 of them (95%) with a redshift determination, in
order to characterize their properties. Our sample (BAT6) allows us to study
the properties of the long GRB population and their evolution with cosmic time.
We focus in particular on the GRB luminosity function, on the spectral-energy
correlations of their prompt emission, on the nature of dark bursts, on
possible correlations between the prompt and the X-ray afterglow properties,
and on the dust extinction.


title: Tinkertoys for the Twisted D-Series

abstract:
  We study 4D N=2 superconformal field theories that arise from the
compactification of 6D N=(2,0) theories of type D_N on a Riemann surface, in
the presence of punctures twisted by a Z_2 outer automorphism. Unlike the
untwisted case, the family of SCFTs is in general parametrized, not by M_{g,n},
but by a branched cover thereof. The classification of these SCFTs is carried
out explicitly in the case of the D_4 theory, in terms of three-punctured
spheres and cylinders, and we provide tables of properties of twisted punctures
for the D_5 and D_6 theories. We find realizations of Spin(8) and Spin(7) gauge
theories with matter in all combinations of vector and spinor representations
with vanishing beta-function, as well as Sp(3) gauge theories with matter in
the 3-index traceless antisymmetric representation.


title:
The Stellar Number Density Distribution in the Local Solar Neighborhood
  is North-South Asymmetric

abstract:
  We study the number density distribution of a sample of K and M dwarf stars,
matched North and South of the Galactic plane within a distance of 2 kpc from
the sun, using observations from the Ninth Data Release of the Sloan Digital
Sky Survey. We determine distances using the photometric parallax method, and
in this context systematic effects exist which could potentially impact the
determination of the number density profile with height from the Galactic plane
--- and ultimately affect a number density North-South asymmetry. They include:
(i) the calibration of the various photometric parallax relations, (ii) the
ability to separate dwarfs from giants in our sample, (iii) the role of stellar
population differences such as age and metallicity, (iv) the ability to
determine the offset of the sun from the Galactic plane, and (v) the correction
for reddening from dust in the Galactic plane, though our stars are at high
Galactic latitudes. We find the various analyzed systematic effects to have a
negligible impact on our observed asymmetry, and using a new and larger sample
of stars we confirm and refine the earlier discovery of Widrow et al. of a
significant Galactic North-South asymmetry in the stellar number density
distribution.


title:
The effect of baryonic streaming motions on the formation of the first
  supermassive black holes

abstract:
  Observations of quasars at redshifts z > 6 reveal that 10^9 Msol supermassive
black holes (SMBHs) had already formed when the Universe was < 0.9 Gyr old. One
hypothesis for the origins of these SMBHs is that they grew from the remnants
of the first generation of massive stars, which formed in low-mass (~ 10^5 to
10^6 Msol) dark matter minihaloes at z > 20. This is the regime where baryonic
streaming motions--the relative velocities of baryons with respect to dark
matter in the early Universe--most strongly inhibit star formation by
suppressing gas infall and cooling. We investigate the impact of this effect on
the growth of the first SMBHs using a suite of high-fidelity,
ellipsoidal-collapse Monte Carlo merger-tree simulations. We find that the
suppression of seed BH formation by the streaming motions significantly reduces
the number density of the most massive BHs at z > 15, but the residual effect
at lower redshifts is essentially negligible. The streaming motions can reduce
by a factor of few the number density of the most luminous quasars at z ~
10-11, where such objects could be detected by the James Webb Space Telescope.
We conclude, with minor theoretical caveats, that baryonic streaming motions
are unlikely to pose a significant additional obstacle to the formation of the
observed high-redshift quasar SMBHs. Nor do they appreciably affect the heating
and reionization histories of the Universe or the merger rates of nuclear BHs
in the mass and redshift ranges of interest for proposed gravitational-wave
detectors.


title:
Electromagnetic signatures of supermassive black hole binaries resolved
  by PTAs

abstract:
  Pulsar timing arrays (PTAs) may eventually be able to detect not only the
stochastic gravitational-wave (GW) background of SMBH binaries, but also
individual, particularly massive binaries whose signals stick out above the
background. In this contribution, we discuss the possibility of identifying and
studying such `resolved' binaries through their electromagnetic emission. The
host galaxies of such binaries are themselves expected to be also very massive
and rare, so that out to redshifts z~2 a unique massive galaxy may be
identified as the host. At higher redshifts, the PTA error boxes are larger and
may contain as many as several hundred massive-galaxy interlopers. In this
case, the true counterpart may be identified, if it is accreting gas
efficiently, as an active galactic nucleus (AGN) with a peculiar spectrum and
variable emission features. Specifically, the binary's tidal torques expel the
gas from the inner part of the accretion disk, making it unusually dim in X-ray
and UV bands and in broad optical emission lines. The tails of the broad wings
of any FeK-alpha emission line may also be `clipped' and missing. The binary's
orbital motion, as well as the gas motions it induces, may trigger
quasiperiodic variations. These include coherent flux variability, such as
luminous, multi-wavelength flares, as well as Doppler shifts of broad emission
lines and `see-saw' oscillations in the FeK-alpha line. Additional features,
such as evidence for a recent major merger or dual collimated jets, could also
corroborate the counterpart. These properties would make resolved PTA sources
stand out among AGN with similar overall luminosities and allow their
identification.


title: Spectral Clustering with Imbalanced Data

abstract:
  Spectral clustering is sensitive to how graphs are constructed from data
particularly when proximal and imbalanced clusters are present. We show that
Ratio-Cut (RCut) or normalized cut (NCut) objectives are not tailored to
imbalanced data since they tend to emphasize cut sizes over cut values. We
propose a graph partitioning problem that seeks minimum cut partitions under
minimum size constraints on partitions to deal with imbalanced data. Our
approach parameterizes a family of graphs, by adaptively modulating node
degrees on a fixed node set, to yield a set of parameter dependent cuts
reflecting varying levels of imbalance. The solution to our problem is then
obtained by optimizing over these parameters. We present rigorous limit cut
analysis results to justify our approach. We demonstrate the superiority of our
method through unsupervised and semi-supervised experiments on synthetic and
real data sets.


title: Information Theory and Moduli of Riemann Surfaces

abstract:
  One interpretation of Torelli's Theorem, which asserts that a compact Riemann
Surface $X$ of genus $g > 1$ is determined by the $g(g+1)/2$ entries of the
period matrix, is that the period matrix is a message about $X$. Since this
message depends on only $3g-3$ moduli, it is sparse, or at least approximately
so, in the sense of information theory. Thus, methods from information theory
may be useful in reconstructing the period matrix, and hence the Riemann
surface, from a small subset of the periods. The results here show that, with
high probability, any set of $3g-3$ periods form moduli for the surface.


title: Gauge Theory Dynamics and Kahler Potential for Calabi-Yau Complex Moduli

abstract:
  We compute the exact two-sphere partition function and matrix of two-point
functions of operators in the chiral ring with their complex conjugates in
two-dimensional supersymmetric gauge theories. For gauge theories that flow in
the infrared to a Calabi-Yau nonlinear sigma model, these renormalization group
invariant observables determine the exact Kahler potential and associated
Zamolodchikov metric in the complex structure moduli space of the Calabi-Yau
manifold.


title: Adatoms and Anderson localization in graphene

abstract:
  We address the nature of the disordered state that results from the
adsorption of adatoms in graphene. For adatoms that sit at the center of the
honeycomb plaquette, as in the case of most transition metals, we show that the
ones that form a zero-energy resonant state lead to Anderson localization in
the vicinity of the Dirac point. Among those, we show that there is a symmetry
class of adatoms where Anderson localization is suppressed, leading to an
exotic metallic state with large and rare charge droplets, that localizes only
at the Dirac point. We identify the experimental conditions for the observation
of the Anderson transition for adatoms in graphene.


title:
Wigner crystal of a two-dimensional electron gas with a strong
  spin-orbit interaction

abstract:
  The Wigner-crystal phase of two-dimensional electrons interacting via the
Coulomb repulsion and subject to a strong Rashba spin-orbit coupling is
investigated. For low enough electronic densities the spin-orbit band splitting
can be larger than the zero-point energy of the lattice vibrations. Then the
degeneracy of the lower subband results in a spontaneous symmetry breaking of
the vibrational ground state. The $60^{\circ}-$rotational symmetry of the
triangular (spin-orbit coupling free) structure is lost, and the unit cell of
the new lattice contains two electrons. Breaking the rotational symmetry also
leads to a (slight) squeezing of the underlying triangular lattice.


title: Breakdown of quasilocality in long-range quantum lattice models

abstract:
  We study the non-equilibrium dynamics of correlations in quantum lattice
models in the presence of long-range interactions decaying asymptotically as a
power law. For exponents larger than the lattice dimensionality, a
Lieb-Robinson-type bound effectively restricts the spreading of correlations to
a causal region, but allows supersonic propagation. We show that this decay is
not only sufficient but also necessary. Using tools of quantum metrology, for
any exponents smaller than the lattice dimension, we construct Hamiltonians
giving rise to quantum channels with capacities not restricted to a causal
region. An analytical analysis of long-range Ising models illustrates the
disappearance of the causal region and the creation of correlations becoming
distance-independent. Numerical results obtained using matrix product state
methods for the XXZ spin chain reveal the presence of a sound cone for large
exponents, and supersonic propagation for small ones. In all models we analyzed
the fast spreading of correlations follows a power law, but not the exponential
increase of the long-range Lieb-Robinson bound.


title: Global and local aspects of causality in quantum mechanics

abstract:
  Quantum mechanics forces us to reconsider certain aspects of classical
causality. The 'central mystery' of quantum mechanics manifests in different
ways, depending on the interpretation. This mystery can be formulated as the
possibility of selecting part of the initial conditions of the Universe
'retroactively'. This talk aims to show that there is a global, timeless,
'bird's view' of the spacetime, which makes this mystery more reasonable. We
will review some well-known quantum effects from the perspective of global
consistency.


title:
Holographic perfect fluidity, Cotton energy-momentum duality and
  transport properties

abstract:
  We investigate background metrics for 2+1-dimensional holographic theories
where the equilibrium solution behaves as a perfect fluid, and admits thus a
thermodynamic description. We introduce stationary perfect-Cotton geometries,
where the Cotton--York tensor takes the form of the energy--momentum tensor of
a perfect fluid, i.e. they are of Petrov type D_t. Fluids in equilibrium in
such boundary geometries have non-trivial vorticity. The corresponding bulk can
be exactly reconstructed to obtain 3+1-dimensional stationary black-hole
solutions with no naked singularities for appropriate values of the black-hole
mass. It follows that an infinite number of transport coefficients vanish for
holographic fluids. Our results imply an intimate relationship between
black-hole uniqueness and holographic perfect equilibrium. They also point
towards a Cotton/energy--momentum tensor duality constraining the fluid
vorticity, as an intriguing boundary manifestation of the bulk mass/nut
duality.


title: On Exact Anisotropic Solutions of Kasner type in Higher Order Gravities

abstract:
  This thesis has considered the existence of anisotropic exact vacuum
solutions in the context of higher order gravities. The investigated models
generally are a function of three scalars R, $R_{\alpha\beta}R^{\alpha\beta}$
and $R_{\alpha\beta\mu\nu}R^{\alpha\beta\mu\nu}$. Near singularity, dominant
terms in the expansion of analytic type of these functions are in terms of
$R^{n}$ (practically $R^{1+\delta}$, for indicating deviation from
Einstein-Hilbert action), ($R_{\alpha\beta}R^{\alpha\beta})^{n}$ or
($R_{\alpha\beta\mu\nu}R^{\alpha\beta\mu\nu})^{n}$. Investigation shows that
there always exists Kasner type solutions in $R^{n}$ and
$R_{\alpha\beta}R^{\alpha\beta})^{n}$ models. But, in the third type model,
anisotropic Kasner type solution has not been found. Furthermore, the behavior
of these models in the presence of matter has been investigated, and it has
been revealed that these solutions are always valid for relativistic matter,
however this is not true for some non relativistic matter. Moreover, the energy
condition for $R^{1+\delta}$ model in vacuum has been investigated and has been
shown that the application of four energy conditions (weak, null, strong and
dominant) leads to one constraint on $\delta$.


title:
Photon Detection in the Cryogenic Apparatus for Precision Tests of Argon
  Interactions with Neutrinos (CAPTAIN)

abstract:
  The Cryogenic Apparatus for Precision Tests of Argon Interactions with
Neutrinos (CAPTAIN) is being built at Los Alamos National Laboratory. A
hexagonal time projection chamber (TPC) with a 1 m drift length will be
constructed inside a cryostat containing 7,700L of liquid argon. CAPTAIN will
be used to test interactions using beams of neutrons and neutrinos. It will
serve as a test bed for various options for the Long Baseline Neutrino
Experiment (LBNE) including in the photon detection system. The current photon
detection system will be described and future options discussed. The system is
composed of sixteen R8520-500 Hamamatsu photomultiplier tubes with a wavelength
shifting coating on acrylic in front of the PMT. Various wavelength shifting
coatings can be examined with the current default of tetraphenyl butadiene.


title:
Simulating the effect of the Sgr A* accretion flow on the appearance of
  G2 after pericenter

abstract:
  We study the dynamical interaction of the G2 cloud with the accretion flow
around Sgr A* by means of three-dimensional, hydrodynamic simulations. We show
the effects of the rotating accretion flow on the evolution of G2 by projecting
the cloud density onto the plane of the sky, and extracting position-velocity
diagrams. We study a number of possible orientations of the cloud orbit with
respect to the disk. We find that once the center of mass of the cloud has
crossed the pericenter, the differences between models becomes significant.
Models with the cloud counter-rotating with respect to the disk are expected to
reach higher blue-shifted line of sight velocities. The spatial extent of the
emission depends strongly on the cloud-to-disk inclination angle. Future
imaging and spectroscopy of G2 emission will shed light both on the structure
of the Sgr A* disk and on the properties of the cloud.


title: Automorphic Equivalence in the Classical Varieties of Linear Algebras

abstract:
  In this paper we consider some classical varieties of linear algebras over
the field which has characteristic 0. For every considered variety we take a
category of the finite generated free algebras of this variety. And for every
this category we calculate the quotient group of the group of the all
automorphisms of this category over the subgroup of the all inner
automorphisms. This quotient group measures difference between the geometric
equivalence and automorphic equivalence of algebras from this variety. In the
all considered varieties of the linear algebras this group is generated by
cosets which are presented by no more than two kinds of the strongly stable
automorphisms of our category. One kind of automorphisms is connected to the
changing of the multiplication by scalar and second one is connected to the
changing of the multiplication of the elements of the algebras. We present some
examples of the pairs of linear algebras such that the considered automorphism
provides the automorphic equivalence of these algebras but these algebras are
not geometrically equivalent. These examples are presented for the all
considered above varieties of algebras and for both these kinds of the strongly
stable automorphisms, when they exist in our group.


title: Leptogenesis and Primordial Magnetic Fields

abstract:
  The anomalous conversion of leptons into baryons during leptogenesis is shown
to produce a right-handed helical magnetic field; in contrast, the magnetic
field produced during electroweak baryogenesis is known to be left-handed. If
the cosmological medium is turbulent, the magnetic field evolves to have a
present day coherence scale and field strength that are of astrophysical
interest. Observations of the amplitude, coherence scale, and helicity of the
intergalactic magnetic field promise to provide a powerful probe of physics
beyond the Standard Model and the very early universe.


title:
ttbar+Large missing energy from top-quark partners: a comprehensive
  study at NLO QCD

abstract:
  We perform a detailed study of top-quark partner production in the ttbar plus
large missing energy final-state at the LHC, presenting results for both scalar
and fermionic top-quark partners in the semi-leptonic and dileptonic decay
modes of the top quarks. We compare the results of several simulation tools:
leading-order matrix elements, next-to-leading order matrix elements,
leading-order plus parton shower simulations, and merged samples that contain
the signal process with an additional hard jet radiated. We find that
predictions from leading-order plus parton shower simulations can significantly
deviate from NLO QCD or LO merged samples and do not correctly model the
kinematics of the ttbar + ETmiss signature. They are therefore not a good
framework for modeling this new physics signature. On the other hand, the
acceptances obtained with a merged sample of the leading-order process together
with the radiation of an additional hard jet are in agreement with the NLO
predictions. We also demonstrate that the scale variation of the inclusive
cross section, plus that of the acceptance, does not accurately reflect the
uncertainty of the cross section after cuts, which is typically larger. We show
the importance of including higher-order QCD corrections when using kinematic
distributions to determine the spin of the top-quark partner.


title: Quark number susceptibilities at high temperatures

abstract:
  We calculate second and fourth order quark number susceptibilities for 2+1
flavor QCD in the high temperature region. In our study we use two improved
staggered fermion formulations, namely the highly improved staggered quark
formulation, and the so-called p4 formulation, as well as several lattice
spacings. Second order quark number susceptibilities are calculated using both
improved staggered fermion formulations, and we show that in the continuum
limit the two formulations give consistent results. The fourth order quark
number susceptibilities are studied only using the p4 formulation and at
non-zero lattice spacings. We compare our results on quark number
susceptibilities with recent weak coupling calculations, and find that these
agree reasonably well with the lattice calculations within the estimated
uncertainties.


title:
Young Stars Near Earth: The Octans-Near Association and Castor Moving
  Group

abstract:
  All cataloged stellar moving groups and associations with ages <100 Myr and
within 100 pc of Earth have Galactic space motions (UVW) situated in a "good
box" with dimensions ~20 km/s on a side. Torres et al. defined the Octans
Association as a group of 15 stars with age "20 Myr?" and located ~140 pc from
Earth, but with average V space velocity -3.6 km/s that is well outside of the
good box. We present a list of 14 Hipparcos star systems within 100 pc of Earth
that we call "Octans-Near"; these systems have UVW similar to those of the much
more distant Octans Association. The Octans-Near stars have apparent ages
between about 30 and 100 Myr and their relationship to the Octans Association
stars is unclear. Six additional star systems have UVW similar to those of
Octans-Near stars and likely ages <200 Myr. These six systems include the
late-type binary star EQ Peg -- 6.2 pc from Earth with likely age <100 Myr and
thus likely to be the nearest known pre-main sequence star system. The UVW of
stars in a previously proposed ~200 Myr old Castor moving group are not too
dissimilar from the UVW of Octans-Near stars. However, stars in the Castor
group -- if it exists at all -- are mostly substantially older than 200 Myr and
thus generally can readily be distinguished from the much younger Octans-Near
stars.


title:
A MOSAIC of methods: Improving ortholog detection through integration of
  algorithmic diversity

abstract:
  Ortholog detection (OD) is a critical step for comparative genomic analysis
of protein-coding sequences. In this paper, we begin with a comprehensive
comparison of four popular, methodologically diverse OD methods: MultiParanoid,
Blat, Multiz, and OMA. In head-to-head comparisons, these methods are shown to
significantly outperform one another 12-30% of the time. This high
complementarity motivates the presentation of the first tool for integrating
methodologically diverse OD methods. We term this program MOSAIC, or Multiple
Orthologous Sequence Analysis and Integration by Cluster optimization. Relative
to component and competing methods, we demonstrate that MOSAIC more than
quintuples the number of alignments for which all species are present, while
simultaneously maintaining or improving functional-, phylogenetic-, and
sequence identity-based measures of ortholog quality. Further, we demonstrate
that this improvement in alignment quality yields 40-280% more confidently
aligned sites. Combined, these factors translate to higher estimated levels of
overall conservation, while at the same time allowing for the detection of up
to 180% more positively selected sites. MOSAIC is available as python package.
MOSAIC alignments, source code, and full documentation are available at
http://pythonhosted.org/bio-MOSAIC.


title:
Spectral functions of strongly correlated extended systems via an exact
  quantum embedding

abstract:
  Density matrix embedding theory (DMET) [Phys. Rev. Lett., 109, 186404
(2012)], introduced a new approach to quantum cluster embedding methods,
whereby the mapping of strongly correlated bulk problems to an impurity with
finite set of bath states was rigorously formulated to exactly reproduce the
entanglement of the ground state. The formalism provided similar physics to
dynamical mean-field theory at a tiny fraction of the cost, but was inherently
limited by the construction of a bath designed to reproduce ground state,
static properties. Here, we generalize the concept of quantum embedding to
dynamic properties and demonstrate accurate bulk spectral functions at
similarly small computational cost. The proposed spectral DMET utilizes the
Schmidt decomposition of a response vector, mapping the bulk dynamic
correlation functions to that of a quantum impurity cluster coupled to a set of
frequency dependent bath states. The resultant spectral functions are obtained
on the real-frequency axis, without bath discretization error, and allows for
the construction of arbitrary dynamic correlation functions. We demonstrate the
method on the 1D and 2D Hubbard model, where we obtain zero temperature,
thermodynamic limit spectral functions, and show the trivial extension to
two-particle Green functions. This advance therefore extends the scope and
applicability of DMET in condensed matter problems as a computationally
tractable route to correlated spectral functions of extended systems, and
provides a competitive alternative to dynamical mean-field theory for dynamic
quantities.


title: Photon Emission Rate Engineering using Graphene Nanodisc Cavities

abstract:
  In this work, we present a systematic study of the plasmon modes in a system
of vertically stacked pair of graphene discs. Quasistatic approximation is used
to model the eigenmodes of the system. Eigen-response theory is employed to
explain the spatial dependence of the coupling between the plasmon modes and a
quantum emitter. These results show a good match between the semi-analytical
calculation and full-wave simulations. Secondly, we have shown that it is
possible to engineer the decay rates of a quantum emitter placed inside and
near this cavity, using Fermi level tuning, via gate voltages and variation of
emitter location and polarization. We highlighted that by coupling to the
bright plasmon mode, the radiative efficiency of the emitter can be enhanced
compared to the single graphene disc case, whereas the dark plasmon mode
suppresses the radiative efficiency.


title:
Direct numerical simulation of the very large anisotropic scales in a
  turbulent channel

abstract:
  Over the last decades the knowledge on the small scales of turbulent wall
flows has experienced a significant advance, especially in the near-wall region
where the highest production of turbulent energy and the maximum turbulence
intensity occur. The development of computers has played an important role in
this progress, making direct numerical simulations affordable (Kim, Moin &
Moser, 1987), and offering wider observational possibilities than most
laboratory experiments. The large scales have received less attention, and it
has not been until recently that their significance and their real size have
been widely recognized, thanks in part to the experiments by Hites (1997) and
Kim & Adrian (1999), and to the compilation of experimental and numerical data
by Jimenez (1998). The requirements of both a very large box and a high
Reynolds number has made direct numerical simulation of the VLAS unapproachable
until today. The purpose of this report is to serve as a preliminary
description of a newly compiled numerical database of the characteristics of
the large scales in turbulent channel flow at moderate Reynolds numbers.


title: Power operations and coactions in highly commutative homology theories

abstract:
  Power operations in the homology of infinite loop spaces, and $H_\infty$ or
$E_\infty$ ring spectra have a long history in Algebraic Topology. In the case
of ordinary mod p homology for a prime p, the power operations of Kudo, Araki,
Dyer and Lashof interact with Steenrod operations via the Nishida relations,
but for many purposes this leads to complicated calculations once iterated
applications of these functions are required.On the other hand, the homology
coaction turns out to provide tractable formulae better suited to exploiting
multiplicative structure.
  We show how to derive suitable formulae for the interaction between power
operations and homology coactions in a wide class of examples; our approach
makes crucial use of modern frameworks for spectra with well behaved smash
products. In the case of mod $p$ homology, our formulae extend those of Bisson
and Joyal to odd primes. We also show how to exploit our results in sample
calculations, and produce some apparently new formulae for the Dyer-Lashof
action on the dual Steenrod algebra.


title:
Longitudinal Mixed Membership trajectory models for disability survey
  data

abstract:
  We develop methods for analyzing discrete multivariate longitudinal data and
apply them to functional disability data on the U.S. elderly population from
the National Long Term Care Survey (NLTCS), 1982-2004. Our models build on a
Mixed Membership framework, in which individuals are allowed multiple
membership on a set of extreme profiles characterized by time-dependent
trajectories of progression into disability. We also develop an extension that
allows us to incorporate birth-cohort effects, in order to assess
inter-generational changes. Applying these methods, we find that most
individuals follow trajectories that imply a late onset of disability, and that
younger cohorts tend to develop disabilities at a later stage in life compared
to their elders.


title: The Large Scale Organization of Turbulent Channels

abstract:
  We have investigated the organization and dynamics of the large turbulent
structures that develop in the logarithmic and outer layers of
high-Reynolds-number wall flows. These structures have sizes comparable to the
flow thickness and contain most of the turbulent kinetic energy. They produce a
substantial fraction of the skin friction and play a key role in turbulent
transport.
  In spite of their significance, there is much less information about the
large structures far from the wall than about the small ones of the near-wall
region. The main reason for this is the joint requirements of large measurement
records and high Reynolds numbers for their experimental analysis. Their
theoretical analysis has been hampered by the lack of succesful models for
their interaction with the background small-scale turbulence.


title: Hecke Groups, Dessins d'Enfants and the Archimedean Solids

abstract:
  Grothendieck's dessins d'enfants arise with ever-increasing frequency in many
areas of 21st century mathematical physics. In this paper, we review the
connections between dessins and the theory of Hecke groups. Focussing on the
restricted class of highly symmetric dessins corresponding to the so-called
Archimedean solids, we apply this theory in order to provide a means of
computing representatives of the associated conjugacy classes of Hecke
subgroups in each case. The aim of this paper is to demonstrate that dessins
arising in mathematical physics can point to new and hitherto unexpected
directions for further research. In addition, given the particular ubiquity of
many of the dessins corresponding to the Archimedean solids, the hope is that
the computational results of this paper will prove useful in the further study
of these objects in mathematical physics contexts.


title: The Parsec-Scale Structure of the Newer TeV Blazars

abstract:
  We expand our previous studies of the parsec-scale structure of TeV blazars
by presenting first-epoch images from VLBA monitoring of ten newer TeV HBLs.
All ten sources were successfully detected and imaged, and all showed a
one-sided core-jet structure. Many display a morphology common to TeV HBLs: a
short, collimated jet followed by a transition to low surface brightness
extended emission with a much broader opening angle. The newly detected TeV
HBLs tend to be fainter in the radio; the median core flux density was 22 mJy,
and the median brightness temperature was 8x10^9 K. The brightness temperatures
are well below the equipartition limit, and thus the VLBI cores do not require
strong beaming, consistent with the modest values of Doppler and Lorentz
factors found in the VLBI jets of TeV HBLs by other studies, and contrasting
with the strong beaming generally required by the TeV emission. We study the
full sample of TeV HBLs that have been observed with VLBI, and find a
correlation between TeV flux and VLBI core brightness temperature, suggesting
different but correlated beaming factors for the TeV and radio emission. We
present a discussion of these observations in the context of velocity
structures in the jets of the TeV HBLs.


title: Hardware Support for Address Mapping in PGAS Languages; a UPC Case Study

abstract:
  The Partitioned Global Address Space (PGAS) programming model strikes a
balance between the locality-aware, but explicit, message-passing model and the
easy-to-use, but locality-agnostic, shared memory model. However, the PGAS rich
memory model comes at a performance cost which can hinder its potential for
scalability and performance. To contain this overhead and achieve full
performance, compiler optimizations may not be sufficient and manual
optimizations are typically added. This, however, can severely limit the
productivity advantage. Such optimizations are usually targeted at reducing
address translation overheads for shared data structures. This paper proposes a
hardware architectural support for PGAS, which allows the processor to
efficiently handle shared addresses. This eliminates the need for such
hand-tuning, while maintaining the performance and productivity of PGAS
languages. We propose to avail this hardware support to compilers by
introducing new instructions to efficiently access and traverse the PGAS memory
space. A prototype compiler is realized by extending the Berkeley Unified
Parallel C (UPC) compiler. It allows unmodified code to use the new
instructions without the user intervention, thereby creating a real productive
programming environment. Two implementations are realized: the first is
implemented using the full system simulator Gem5, which allows the evaluation
of the performance gain. The second is implemented using a softcore processor
Leon3 on an FPGA to verify the implementability and to parameterize the cost of
the new hardware and its instructions. The new instructions show promising
results for the NAS Parallel Benchmarks implemented in UPC. A speedup of up to
5.5x is demonstrated for unmodified and unoptimized codes. Unoptimized code
performance using this hardware was shown to also surpass the performance of
manually optimized code by up to 10%.


title:
Transit Timing Variation of Near-Resonance Planetary Pairs. II.
  Confirmation of 30 planets in 15 Multiple Planet Systems

abstract:
  Following on from Paper I in our series (Xie 2013), we report the
confirmation by Transit Timing Variations (TTVs) of a further 30 planets in 15
multiple planet systems, using the publicly available Kepler light curves
(Q0-Q16). All of these fifteen pairs are near first-order Mean Motion
Resonances (MMR), showing sinusoidal TTVs consistent with theoretically
predicted periods, which demonstrate they are orbiting and interacting in the
same systems. Although individual masses cannot be accurately extracted based
only on TTVs (because of the well known degeneracy between mass and
eccentricity), the measured TTV phases and amplitudes can still place
relatively tight constraints on their mass ratios and upper limits on their
masses, which confirm their planetary nature. Some of these systems (KOI-274,
KOI-285, KOI-370 and KOI-2672) are relatively bright and thus suitable for
further follow-up observations.

categories: astro-ph.EP astro-ph.CO astro-ph.GA astro-ph.IM astro-ph.SR


title: Critical $O(d)$-equivariant biharmonic maps

abstract:
  We study $O(d)$-equivariant biharmonic maps in the critical dimension. A
major consequence of our study concerns the corresponding heat flow. More
precisely, we prove that blowup occurs in the biharmonic map heat flow from
$B^4(0, 1)$ into $S^4$. To our knowledge, this was the first example of blowup
for the biharmonic map heat flow. Such results have been hard to prove, due to
the inapplicability of the maximum principle in the biharmonic case.
Furthermore, we classify the possible $O(4)$-equivariant biharmonic maps from
$\mathbf{R}^4$ into $S^4$, and we show that there exists, in contrast to the
harmonic map analogue, equivariant biharmonic maps from $B^4(0,1)$ into $S^4$
that wind around $S^4$ as many times as we wish. We believe that the ideas
developed herein could be useful in the study of other higher-order parabolic
equations.


title:
Investigation of TiO$_x$ barriers for their use in hybrid Josephson and
  tunnelling junctions based on Ba-122 thin films

abstract:
  We tested oxidized titanium layers as barriers for hybrid Josephson junctions
with high $I_cR_n$-products and for the preparation of junctions for tunneling
spectroscopy. For that we firstly prepared junctions with conventional
superconductor electrodes lead and niobium, respectively. By tuning the barrier
thickness we were able to change the junctions' behavior from a Josephson
junction to tunnel-like behavior applicable for quasi-particle spectroscopy.
Subsequently, we transferred the technology to junctions using Co-doped
BaFe$_2$As$_2$ thin films prepared by pulsed laser deposition as base electrode
and evaporated Pb as counter electrode. For barriers with a thickness of
1.5\,nm we observe clear Josephson effects with $I_cR_n$\,$\approx$\,90\,$\mu$V
at 4.2\,K. These junctions behave SNS'-like and are dominated by Andreev
reflection transport mechanism. For junctions with barrier thickness of 2.0\,nm
and higher no Josephson but SIS'- or SINS'-like behavior with a tunnel-like
conductance spectrum was observed.


title:
Two Mass Distributions in the L 1641 Molecular Clouds: The Herschel
  connection of Dense Cores and Filaments in Orion A

abstract:
  We present the Herschel Gould Belt survey maps of the L1641 molecular clouds
in Orion A. We extracted both the filaments and dense cores in the region. We
identified which of dense sources are proto- or pre-stellar, and studied their
association with the identified filaments. We find that although most (71%) of
the pre-stellar sources are located on filaments there is still a significant
fraction of sources not associated with such structures. We find that these two
populations (on and off the identified filaments) have distinctly different
mass distributions. The mass distribution of the sources on the filaments is
found to peak at 4 Solar masses and drives the shape of the CMF at higher
masses, which we fit with a power law of the form dN/dlogM \propto
M^{-1.4+/-0.4}. The mass distribution of the sources off the filaments, on the
other hand, peaks at 0.8 Solar masses and leads to a flattening of the CMF at
masses lower than ~4 Solar masses. We postulate that this difference between
the mass distributions is due to the higher proportion of gas that is available
in the filaments, rather than in the diffuse cloud.


title:
Alternate Science Investigations for the Kepler Spacecraft: Precision
  Rotation Periods and Shapes of Near-Earth Asteroids

abstract:
  We propose to use a modest fraction of the re-purposed Kepler mission time
and apertures to greatly increase the quantity and quality of our knowledge of
near-Earth asteroids (NEAs) rotation and shape. NEAs are important for
understanding the origins of the Solar System, for selecting targets for
robotic and human visits, and for hazardous object deflection. While NEAs are
being discovered at a rate of 1000/year, only a ~75/year have well-measured
rotation periods and shapes. Not only can the Kepler mission greatly increase
the numbers of well-determined NEA rotation periods (to >1000 in 5 years), but
may do so with order-of-magnitude greater precision than is routinely achieved
from the ground. This will enable 3-D tomographic maps to be produced for the
~250 of the brighter NEAs. A multi-year science program would enable improved
data quality checks, larger samples and additional types of science. All these
numbers are preliminary. We list a number of issues to be resolved before this
program can be properly assessed.


title:
An Efficient Key Agreement Scheme for Wireless Sensor Networks Using
  Third Parties

abstract:
  This paper contributes to the challenging field of security for wireless
sensor networks by introducing a key agreement scheme in which sensor nodes
create secure radio connections with their neighbours depending on the aid of
third parties. These third parties are responsible only for the pair-wise key
establishment among sensor nodes, so they do not observe the physical
phenomenon nor route data packets to other nodes. The proposed method is
explained here with respect to four important issues: how secret shares are
distributed, how local neighbours are discovered, how legitimate third parties
are verified, and how secure channels are established. Moreover, the
performance of the scheme is analyzed with regards to five metrics: local
connectivity, resistance to node capture, memory usage, communication overhead,
and computational burden. Our scheme not only secures the transmission channels
of nodes but also guarantees high local connectivity of the sensor network, low
usage of memory resources, perfect network resilience against node capture, and
complete prevention against impersonation attacks. As it is demonstrated in
this paper, using a number of third parties equals to 10% of the total number
of sensor nodes in the area of interest, the proposed method can achieve at
least 99.42% local connectivity with a very low usage of available storage
resources (less than 385 bits on each sensor node).


title:
Real space Green's function approach to angle resolved resonant
  photoemission: spin polarization and circular dichroism in itinerant magnets

abstract:
  A first principles approach, based on the real space multiple scattering
Green's function method, is presented for spin- and angle-resolved resonant
photoemission from magnetic surfaces. It is applied to the Fe(010) valence band
photoemission excited with circularly polarized X-rays around the Fe L3
absorption edge. When the photon energy is swept through the Fe 2p-3d
resonance, the valence band spectra are strongly modified in terms of absolute
and relative peak intensities, degree of spin-polarization and light
polarization dependence. New peaks in the spin-polarized spectra are identified
as spin-flip transitions induced by exchange decay of spin-mixed core-holes. By
comparison with single atom and band structure data, it is shown that both
intra-atomic and multiple scattering effects strongly influence the spectra. We
show how the different features linked to states of different orbital symmetry
in the d band are differently enhanced by the resonant effect. The appearance
and origin of circular dichroism and spin polarization are analyzed for
different geometries of light incidence and electron emission direction,
providing guidelines for future experiments.


title: On Higher-Dimensional Oscillation in Ergodic Theory

abstract:
  We extend the results of Jones, Rosenblatt, and Wierdl concerning
higher-dimensional oscillation in ergodic theory in a variety of ways. We do so
by transference to the integer lattice, where we employ technique from
(discrete) harmonic analysis.


title:
Stability of chromomagnetic condensation and mass generation for
  confinement in SU(2) Yang-Mills theory

abstract:
  We show that the Nielsen-Olesen instability of the Savvidy vacuum with a
homogeneous chromomagnetic condensation disappears in the framework of the
functional renormalization group. This result follows from our observations:
(i) the vanishing imaginary part of the effective average action is realized
for arbitrary infrared cutoff as a novel fixed point solution of the flow
equation for the complex-valued effective average action and (ii) an
approximate analytical solution for the effective average action is obtained
without the pure imaginary part for large infrared cutoff. This result suggests
that there exists a physical mechanism for maintaining the stability or staying
on the fixed point even for sufficiently small infrared cutoff. We argue that
dynamical gluon mass generation (related to two-gluon bound states identified
with glueballs) occurs due to the Becchi-Rouet-Stora-Tyutin-invariant vacuum
condensate of mass dimension two without causing instability.