title:
Bounds on Embeddings of Rational Homology Balls in Symplectic
  4-manifolds

abstract:
  The rational homology balls $B_n$ appeared in Fintushel and Stern's rational
blow-down construction [FS2]. Later, Symington [Sy1], defined this operation in
the symplectic category. In [Kh2], the author defined the inverse procedure,
the symplectic rational blow-up. In this paper, we study the obstructions to
symplectically rationally blowing up a symplectic 4-manifold, i.e. the
obstructions to symplectically embedding the rational homology balls $B_n$ into
a symplectic 4-manifold. We prove a theorem and give additional examples which
suggest that in order to symplectically embed the rational homology balls
$B_n$, for high n, a symplectic 4-manifold must at least have a high enough
$c_1^2$ as well.


title:
"Secret Santa" and the Combined Length of Spanned Cycles in a Random
  Permutation

abstract:
  In many schools throughout the United States, it is customary to hold a
yearly "Secret Santa" event. With the approach of Christmas, all the students
place their names in a hat; each student, in turn, draws a name out of the hat,
thus becoming Secret Santa to the student whose name is drawn. On the day
before Christmas break, each student places a gift in front of the locker of
the student to whom she or he is Secret Santa.
  Unfortunately, children being children, some students might forget to bring
gifts on this day. Students who do not find gifts next to their lockers,
feeling cheated, angrily take their gifts back from their recipients, who in
turn reclaim their gifts from their recipients, and so forth.
  We analyze the distribution of the number $L$ of students whose Christmas is
ruined, as a function of the number of students who do not bring gifts. We give
a simple, explicit formula for the probability of every possible value for $L$
(backed by three proofs of distinct flavors), as well as closed-form formulae
for its expectation and variance. Notably, we show that if $m$ kids forget to
bring gifts, then the expected fraction of kids whose Christmas is not ruined
is less than $\frac{1}{m+1}$ (regardless of the total number of students), with
low probability for a large deviation from this fraction.
  The underlying theoretical results are applicable to the study of
manipulation in matching markets within game theory.


title: The proton spin decomposition : path dependence and gauge symmetry

abstract:
  We discuss the different types of decomposition of the proton spin. We stress
that, despite their lack of uniqueness, the Chen et al. and Wakamatsu
decompositions are perfectly measurable. We argue that a large part of the
recent controversies boils down to the fact that there actually exist two types
of gauge transformations in the Chen et al. approach, where physical and gauge
degrees of freedom of the gauge potential are explicitly separated. By
carefully distinguishing these two types of gauge transformations, one can
easily understand how the concepts of gauge invariance, Stueckelberg symmetry,
path dependence and measurability are linked to each other.


title: On the He burning phases of the Carina dSph

abstract:
  We performed a detailed comparison between predicted He burning phases and
multiband photometry of the Carina dwarf spheroidal galaxy. We found a good
agreement with the predictions computed assuming an {\alpha}-enhanced chemical
mixture, indicating a mean metallicity [Fe/H] ~ -1.8 with a raw observed
peak-to-peak spread in iron abundance of 0.4\pm0.2 dex.


title:
Information-based fitness and the emergence of criticality in living
  systems

abstract:
  Empirical evidence suggesting that living systems might operate in the
vicinity of critical points, at the borderline between order and disorder, has
proliferated in recent years, with examples ranging from spontaneous brain
activity to flock dynamics. However, a well-founded theory for understanding
how and why interacting living systems could dynamically tune themselves to be
poised in the vicinity of a critical point is lacking. Here we employ tools
from statistical mechanics and information theory to show that complex adaptive
or evolutionary systems can be much more efficient in coping with diverse
heterogeneous environmental conditions when operating at criticality.
Analytical as well as computational evolutionary and adaptive models vividly
illustrate that a community of such systems dynamically self-tunes close to a
critical state as the complexity of the environment increases while they remain
non-critical for simple and predictable environments. A more robust convergence
to criticality emerges in co-evolutionary and co-adaptive set-ups in which
individuals aim to represent other agents in the community with fidelity,
thereby creating a collective critical ensemble and providing the best possible
trade-off between accuracy and flexibility. Our approach provides a
parsimonious and general mechanism for the emergence of critical-like behavior
in living systems needing to cope with complex environments or trying to
efficiently coordinate themselves as an ensemble.


title: From transistor to trapped-ion computers for quantum chemistry

abstract:
  Over the last few decades, quantum chemistry has progressed through the
development of computational methods based on modern digital computers.
However, these methods can hardly fulfill the exponentially-growing resource
requirements when applied to large quantum systems. As pointed out by Feynman,
this restriction is intrinsic to all computational models based on classical
physics. Recently, the rapid advancement of trapped-ion technologies has opened
new possibilities for quantum control and quantum simulations. Here, we present
an efficient toolkit that exploits both the internal and motional degrees of
freedom of trapped ions for solving problems in quantum chemistry, including
molecular electronic structure, molecular dynamics, and vibronic coupling. We
focus on applications that go beyond the capacity of classical computers, but
may be realizable on state-of-the-art trapped-ion systems. These results allow
us to envision a new paradigm of quantum chemistry that shifts from the current
transistor to a near-future trapped-ion-based technology.


title:
Environmental vs demographic variability in stochastic predator-prey
  models

abstract:
  In contrast to the neutral population cycles of the deterministic mean-field
Lotka--Volterra rate equations, including spatial structure and stochastic
noise in models for predator-prey interactions yields complex spatio-temporal
structures associated with long-lived erratic population oscillations.
Environmental variability in the form of quenched spatial randomness in the
predation rates results in more localized activity patches. Population
fluctuations in rare favorable regions in turn cause a remarkable increase in
the asymptotic densities of both predators and prey. Very intriguing features
are found when variable interaction rates are affixed to individual particles
rather than lattice sites. Stochastic dynamics with demographic variability in
conjunction with inheritable predation efficiencies generate non-trivial time
evolution for the predation rate distributions, yet with overall essentially
neutral optimization.


title: Integer Frames

abstract:
  Finite frame theory has become a powerful tool for many applications of
mathematics. In this paper we introduce a new area of research in frame theory:
Integer frames. These are frames having all integer coordinates with respect to
a fixed orthonormal basis for a Hilbert space. Integer frames have potential to
mitigate quantization errors and transmission losses as well as speeding up
computation times. This paper gives the first systematic study of this
important class of finite Hilbert space frames.


title:
H Index of scientific Nursing journals according to Google Scholar
  Metrics (2007-2011)

abstract:
  The aim of this report is to present a ranking of Nursing journals covered in
Google Scholar Metrics (GSM), a Google product launched in 2012 to assess the
impact of scientific journals from citation counts this receive on Google
Scholar. Google has chosen to include only those journals that have published
at least 100 papers and have at least one citation in a period of five years
(2007-2011). Journal rankings are sorted by languages (showing the 100 papers
with the greatest impact). This tool allows to sort by subject areas and
disciplines, but only in the case of journals in English. In this case, it only
shows the 20 journals with the highest h index. This option is not available
for journals in the other nine languages present in Google (Chinese,
Portuguese, German, Spanish, French, Korean, Japanese, Dutch and Italian).
  Google Scholar Metrics doesnt currently allow to group and sort all journals
belonging to a scientific discipline. In the case of Nursing, in the ten
listings displayed by GSM we can only locate 34 journals. Therefore, in an
attempt to overcome this limitation, we have used the diversity of search
procedures allowed by GSM to identify the greatest number of scientific
journals of Nursing with h index calculated by this bibliometric tool.
Bibliographic searches were conducted between 10th and 30th May 2013.
  The result is a ranking of 337 nursing journals sorted by the same h index,
and mean as discriminating value. Journals are also grouped by quartiles.


title:
A nonintrusive method to approximate linear systems with nonlinear
  parameter dependence

abstract:
  We consider a family of linear systems $A_\mu \alpha=C$ with system matrix
$A_\mu$ depending on a parameter $\mu$ and for simplicity parameter-independent
right-hand side $C$. These linear systems typically result from the
finite-dimensional approximation of a parameter-dependent boundary-value
problem. We derive a procedure based on the Empirical Interpolation Method to
obtain a separated representation of the system matrix in the form
$A_\mu\approx\sum_{m}\beta_m(\mu)A_{\mu_m}$ for some selected values of the
parameter. Such a separated representation is in particular useful in the
Reduced Basis Method. The procedure is called nonintrusive since it only
requires to access the matrices $A_{\mu_m}$. As such, it offers a crucial
advantage over existing approaches that instead derive separated
representations requiring to enter the code at the level of assembly. Numerical
examples illustrate the performance of our new procedure on a simple
one-dimensional boundary-value problem and on three-dimensional acoustic
scattering problems solved by a boundary element method.


title:
Massive gauge boson pair production at the LHC: a next-to-leading order
  story

abstract:
  Electroweak gauge boson pair production is one of the most important Standard
Model processes at the LHC, not only because it is a benchmark process but also
by its ability to probe the electroweak interaction directly. We present full
next-to-leading order predictions for the production cross sections and
distributions of on-shell massive gauge boson pair production in the Standard
Model. This includes the QCD and electroweak (EW) corrections. We study the
hierarchy between the different channels when looking at the size of the QCD
gluon-induced processes and the EW photon-induced processes and provide the
first comprehensive explanation of this hierarchy thanks to analytical
leading-logarithmic results. We also provide a detailed study of the
theoretical uncertainties affecting the total cross section predictions that
stem from scale variation, parton distribution function and $\alpha_s$ errors.
We then compare with the present LHC data.


title: Coordination Control of Discrete-Event Systems Revisited

abstract:
  In this paper, we revise and further investigate the coordination control
approach proposed for supervisory control of distributed discrete-event systems
with synchronous communication based on the Ramadge-Wonham automata framework.
The notions of conditional decomposability, conditional controllability, and
conditional closedness ensuring the existence of a solution are carefully
revised and simplified. The paper is generalized to non-prefix-closed
languages, that is, supremal conditionally controllable sublanguages of not
necessary prefix-closed languages are discussed. Non-prefix-closed languages
introduce the blocking issue into coordination control, hence a procedure to
compute a coordinator for nonblockingness is included. The optimization problem
concerning the size of a coordinator is under investigation. We prove that to
find the minimal extension of the coordinator event set for which a given
specification language is conditionally decomposable is NP-hard. In other
words, unless P=NP, it is not possible to find a polynomial algorithm to
compute the minimal coordinator with respect to the number of events.


title:
Building patterns by traveling vortices and dipoles in periodic
  dissipative media

abstract:
  We analyze pattern-formation scenarios in the two-dimensional (2D) complex
Ginzburg-Landau (CGL) equation with the cubic-quintic (CQ) nonlinearity and a
cellular potential. The equation models laser cavities with built-in gratings,
which are used to stabilize 2D patterns. The pattern-building process is
initiated by kicking a localized compound mode, in the form of a dipole,
quadrupole, or vortex which is composed of four local peaks. The hopping motion
of the kicked mode through the cellular structure leads to the generation of
various extended patterns pinned by the structure. In the ring-shaped system,
the persisting freely moving dipole hits the stationary pattern from the
opposite side, giving rise to several dynamical regimes, with the pinned
multi-soliton chain playing the role of the Newton's cradle (NC).


title: A polynomial projection-type algorithm for linear programming

abstract:
  We propose a simple O([n^5/\log n]L) algorithm for linear programming
feasibility, that can be considered as a polynomial-time implementation of the
relaxation method. Our work draws from Chubanov's "Divide-and-Conquer"
algorithm [4], where the recursion is replaced by a simple and more efficient
iterative method. A similar approach was used in a more recent paper of
Chubanov [6].


title:
Multicharged optical vortices induced in a dissipative atomic vapor
  system

abstract:
  We investigate numerically the dynamics of optical vortex beams carrying
different topological charges, launched in a dissipative three level ladder
type nonlinear atomic vapor. We impose the electromagnetically induced
transparency (EIT) condition on the medium. Linear, cubic, and quintic
susceptibilities, considered simultaneously with the dressing effect, are
included in the analysis. Generally, the beams slowly expand during propagation
and new vortices are induced, commonly appearing in oppositely charged pairs.
We demonstrate that not only the form and the topological charge of the
incident beam, but also its growing size in the medium greatly affect the
formation and evolution of vortices. We formulate common rules for finding the
number of induced vortices and the corresponding rotation directions, stemming
from the initial conditions of various incident beams, as well as from the
dynamical aspects of their propagation. The net topological charge of the
vortex is conserved during propagation, as it should be, but the total number
of charges is not necessarily same as the initial number, because of the
complex nature of the system. When the EIT condition is lifted, an enhancement
region of beam dynamics if reached, in which the dynamics and the expansion of
the beam greatly accelerate. In the end, we discuss the liquid like behavior of
light evolution in this dissipative system and propose a potential experimental
scheme for observing such a behavior.


title: 3D particle tracking velocimetry using dynamic discrete tomography

abstract:
  Particle tracking velocimetry in 3D is becoming an increasingly important
imaging tool in the study of fluid dynamics, combustion as well as plasmas. We
introduce a dynamic discrete tomography algorithm for reconstructing particle
trajectories from projections. The algorithm is efficient for data from two
projection directions and exact in the sense that it finds a solution
consistent with the experimental data. Non-uniqueness of solutions can be
detected and solutions can be tracked individually.


title:
NNLO non-resonant corrections to threshold top-pair production from e+
  e- collisions: Endpoint-singular terms

abstract:
  We analyse the subleading non-resonant contributions to the e+ e- -> W+ W- b
bbar cross section at energies near the top-antitop threshold. These correspond
to next-to-next-to-leading-order (NNLO) corrections with respect to the
leading-order resonant result. We show that these corrections produce 1/epsilon
endpoint singularities which precisely cancel the finite-width divergences
arising in the resonant production of the W+ W- b bbar final state from
on-shell decays of the top and antitop quarks at the same order. We also
provide analytic results for the (m_t/Lambda)^2, (m_t/Lambda) and
(m_t/Lambda)^0 log(Lambda) terms that dominate the expansion in powers of
(Lambda/m_t) of the complete set of NNLO non-resonant corrections, where Lambda
is a cut imposed on the invariant masses of the b W pairs that is neither too
tight nor too loose (m_t Gamma_t << Lambda^2 << m_t^2).


title:
The effect of heat treatments and coatings on the outgassing rate of
  stainless steel chambers

abstract:
  The outgassing rates of three nominally identical 304L stainless steel vacuum
chambers were measured to determine the effect of chamber coatings and heat
treatments. One chamber was coated with titanium nitride (TiN) and one with
amorphous silicon (a-Si) immediately following fabrication. The last chamber
was first tested without any coating, and then coated with a-Si following a
series of heat treatments. The outgassing rate of each chamber was measured at
room temperatures between 15 and 30 {\deg}C following bakes at temperatures
between 90 and 400 {\deg}C. Measurements for bare steel showed a significant
reduction in the outgassing rate by nearly a factor of 20 after a 400 {\deg}C
heat treatment (3.5x10-12 Torr L s-1 cm-2 prior to heat treatment, reduced to
1.7x10-13 Torr L s-1 cm-2 following heat treatment). The chambers that were
coated with a-Si showed minimal change in outgassing rates with heat treatment,
though an outgassing rate reduced by heat treatments prior to a-Si coating was
successfully preserved throughout a series of bakes. The TiN coated chamber
exhibited remarkably low outgassing rates, up to four orders of magnitude lower
than the uncoated stainless steel, but the uncertainty in these rates is large
due to the sensitivity limitations of the spinning rotor gauge accumulation
measurement and the possibility of a small pump speed due to inhomogeneity in
the TiN coating. The outgassing results are discussed in terms of
diffusion-limited versus recombination-limited processes.


title: Computing Similarity Distances Between Rankings

abstract:
  We address the problem of computing distances between rankings that take into
account similarities between candidates. The need for evaluating such distances
is governed by applications as diverse as rank aggregation, bioinformatics,
social sciences and data storage. The problem may be summarized as follows:
Given two rankings and a positive cost function on transpositions that depends
on the similarity of the candidates involved, find a smallest cost sequence of
transpositions that converts one ranking into another. Our focus is on costs
that may be described via special metric-tree structures and on complete
rankings modeled as permutations. The presented results include a
quadratic-time algorithm for finding a minimum cost decomposition for simple
cycles, and a quadratic-time, $4/3$-approximation algorithm for permutations
that contain multiple cycles. The proposed methods rely on investigating a
newly introduced balancing property of cycles embedded in trees, cycle-merging
methods, and shortest path optimization techniques.


title:
The electric quadrupole moment of molecular hydrogen ions and their
  potential for a molecular ion clock

abstract:
  The systematic shifts of the transition frequencies in the molecular hydrogen
ions are of relevance to ultra-high-resolution radio-frequency, microwave and
optical spectroscopy of these systems, performed in ion traps. We develop the
ab-initio description of the interaction of the electric quadrupole moment of
this class of molecules with the static electric field gradients present in ion
traps. In good approximation, it is described in terms of an effective
perturbation hamiltonian. An approximate treatment is then performed in the
Born-Oppenheimer approximation. We give an expression of the electric
quadrupole coupling parameter valid for all hydrogen molecular ion species and
evaluate it for a large number of states of H2+, HD+, and D2+. The systematic
shifts can be evaluated as simple expectation values of the perturbation
hamiltonian. Results on radio-frequency (M1), one-photon electric dipole (E1)
and two-photon E1 transitions between hyperfine states in HD+ are reported. For
two-photon E1 transitions between rotationless states the shifts vanish. For a
subset of rovibrational one-photon transitions the quadrupole shifts range from
0.2 to 10 Hz for an electric field gradient of 0.1 GV/m2. We point out an
experimental procedure for determining the quadrupole shift which will allow
reducing its contribution to the uncertainty of unperturbed rovibrational
transition frequencies to the 1.10^(-15) relative level and, for selected
transitions, even below it. The combined contributions of black-body radiation,
Zeeman, Stark and quadrupole effects are considered for a large set of
transitions and it is estimated that the transition frequency uncertainty of
selected transitions can be reduced below the 1.10^(-15) level.


title:
Transverse momentum resummation for color sextet and antitriplet scalar
  production at the LHC

abstract:
  We study the factorization and resummation of the transverse momentum
spectrum of the color sextet and antitriplet scalars produced at the LHC based
on soft-collinear effective theory. Compared to Z boson and Higgs production, a
soft function is required to account for the soft gluon emission from the
final-state colored scalar. The soft function is calculated at the
next-to-leading order, and the resummation is performed at the approximate
next-to-next-to-leading logarithmic accuracy. The non-perturbative effects and
PDF uncertainties are also discussed.


title: Sparsity-Promoting Optimal Wide-Area Control of Power Networks

abstract:
  Inter-area oscillations in bulk power systems are typically poorly
controllable by means of local decentralized control. Recent research efforts
have been aimed at developing wide- area control strategies that involve
communication of remote signals. In conventional wide-area control, the control
structure is fixed a priori typically based on modal criteria. In contrast,
here we employ the recently-introduced paradigm of sparsity- promoting optimal
control to simultaneously identify the optimal control structure and optimize
the closed-loop performance. To induce a sparse control architecture, we
regularize the standard quadratic performance index with an l1-penalty on the
feedback matrix. The quadratic objective functions are inspired by the classic
slow coherency theory and are aimed at imitating homogeneous networks without
inter-area oscillations. We use the New England power grid model to demonstrate
that the proposed combination of the sparsity-promoting control design with the
slow coherency objectives performs almost as well as the optimal centralized
control while only making use of a single wide-area communication link. In
addition to this nominal performance, we also demonstrate that our control
strategy yields favorable robustness margins and that it can be used to
identify a sparse control architecture for control design via alternative
means.


title: Kahler potentials for Planck inflation

abstract:
  We assess which Kahler potentials in supergravity lead to viable single-field
inflationary models that are consistent with Planck. We highlight the role of
symmetries, such as shift, Heisenberg and supersymmetry, in these
constructions. Also the connections to string theory are pointed out. Finally,
we discuss a supergravity model for arbitrary inflationary potentials that is
suitable for open string inflation and generalize it to the case of closed
string inflation. Our model includes the recently discussed supergravity
reformulation of the Starobinsky model of inflation as well as an interesting
alternative with comparable predictions.


title:
Arbitrary tip orientation in STM simulations: 3D WKB theory and
  application to W(110)

abstract:
  We extend the orbital-dependent electron tunneling model implemented within
the three-dimensional (3D) Wentzel-Kramers-Brillouin (WKB) atom-superposition
approach for simulating scanning tunneling microscopy (STM) by including
arbitrary tip orientations. The orientation of the tip is characterized by a
local coordinate system centered on the tip apex atom obtained by a rotation
with respect to the sample coordinate system. The rotation is described by the
Euler angles. Applying our method, we highlight the role of the real-space
shape of the electron orbitals involved in the tunneling, and analyze the
convergence and the orbital contributions of the tunneling current above the
W(110) surface depending on the orientation of a model tungsten tip. We also
simulate STM images at constant-current condition, and find that their quality
depends very much on the tip orientation. Some orientations result in
protrusions on the images that do not occur above W atoms. The presence of such
apparent atom positions makes it difficult to identify the exact position of
surface atoms. It is suggested that this tip orientation effect should be
considered at the evaluation of experimental STM images on other surfaces as
well. The presented computationally efficient tunneling model could prove to be
useful for obtaining more information on the local tip geometry and orientation
by comparing STM experiments to a large number of simulations with
systematically varied tip orientations.


title: Macro photography with a tablet: applications on Science Teaching

abstract:
  In this work we present a simple way to get Macro photography (enlarged
photographs) using a tablet or phone. We initially discuss the technique, which
is essentially the accommodation of a drop of water on the camera lens. Next,
we explore some applications to science teaching in primary and secondary
levels. As discussed in the text, the simplicity and power of the technique may
make it a good teaching tool for use in various disciplines such as Science,
Biology and Physics.


title: Conceptual Foundations of Diffusion in Magnetic Resonance

abstract:
  A thorough review of the q-space technique is presented starting from a
discussion of Fick's laws. The work presented here is primarily conceptual,
theoretical and hopefully pedagogical. We offered the notion of molecular
concentration to unify Fick's laws and diffusion MRI within a coherent
conceptual framework. The fundamental relationship between diffusion MRI and
the Fick's laws are carefully established. The conceptual and theoretical basis
of the q-space technique is investigated from first principles.


title: A Broadband Scalar Vortex Coronagraph

abstract:
  Broadband coronagraphy with deep nulling and small inner working angle has
the potential of delivering images and spectra of exoplanets and other faint
objects. In recent years, many coronagraphic schemes have been proposed, the
most promising being the optical vortex phase mask coronagraphs. In this paper,
a new scheme of broadband optical scalar vortex coronagraph is proposed and
characterized experimentally in the laboratory. Our setup employs a pair of
computer generated phase gratings (one of them containing a singularity) to
control the chromatic dispersion of phase plates and achieves a constant
peak-to-peak attenuation below $1\cdot 10^{-3}$ over a bandwidth of 120 nm
centered at 700 nm. An inner working angle of ~\lambda/D is demonstrated along
with a raw contrast of 11.5 magnitudes at 2\lambda/D.


title: Double-Scaling Limit of the O(N)-Symmetric Anharmonic Oscillator

abstract:
  In an earlier paper it was argued that the conventional double-scaling limit
of an O(N)-symmetric quartic quantum field theory is inconsistent because the
critical coupling constant is negative and thus the integral representing the
partition function of the critical theory does not exist. In this earlier paper
it was shown that for an O(N)-symmetric quantum field theory in
zero-dimensional spacetime one can avoid this difficulty if one replaces the
original quartic theory by its PT-symmetric analog. In the current paper an
O(N)-symmetric quartic quantum field theory in one-dimensional spacetime [that
is, O(N)-symmetric quantum mechanics] is studied using the Schroedinger
equation. It is shown that the global PT-symmetric formulation of this
differential equation provides a consistent way to perform the double-scaling
limit of the O(N)-symmetric anharmonic oscillator. The physical nature of the
critical behavior is explained by studying the PT-symmetric quantum theory and
the corresponding and equivalent Hermitian quantum theory.


title: Stabilizing entanglement autonomously between two superconducting qubits

abstract:
  Quantum error-correction codes would protect an arbitrary state of a
multi-qubit register against decoherence-induced errors, but their
implementation is an outstanding challenge for the development of large-scale
quantum computers. A first step is to stabilize a non-equilibrium state of a
simple quantum system such as a qubit or a cavity mode in the presence of
decoherence. Several groups have recently accomplished this goal using
measurement-based feedback schemes. A next step is to prepare and stabilize a
state of a composite system. Here we demonstrate the stabilization of an
entangled Bell state of a quantum register of two superconducting qubits for an
arbitrary time. Our result is achieved by an autonomous feedback scheme which
combines continuous drives along with a specifically engineered coupling
between the two-qubit register and a dissipative reservoir. Similar autonomous
feedback techniques have recently been used for qubit reset and the
stabilization of a single qubit state, as well as for creating and stabilizing
states of multipartite quantum systems. Unlike conventional, measurement-based
schemes, an autonomous approach counter-intuitively uses engineered dissipation
to fight decoherence, obviating the need for a complicated external feedback
loop to correct errors, simplifying implementation. Instead the feedback loop
is built into the Hamiltonian such that the steady state of the system in the
presence of drives and dissipation is a Bell state, an essential building-block
state for quantum information processing. Such autonomous schemes, broadly
applicable to a variety of physical systems as demonstrated by a concurrent
publication with trapped ion qubits, will be an essential tool for the
implementation of quantum-error correction.


title: Effective Field Theory of Cosmological Perturbations

abstract:
  The effective field theory of cosmological perturbations stems from
considering a cosmological background solution as a state displaying
spontaneous breaking of time translations and (adiabatic) perturbations as the
related Nambu-Goldstone modes. With this insight, one can systematically
develop a theory for the cosmological perturbations during inflation and, with
minor modifications, also describe in full generality the gravitational
interactions of dark energy, which are relevant for late-time cosmology. The
formalism displays a unique set of Lagrangian operators containing an
increasing number of cosmological perturbations and derivatives. We give an
introductory description of the unitary gauge formalism for theories with
broken gauge symmetry---that allows to write down the most general
Lagrangian---and of the Stueckelberg "trick"---that allows to recover gauge
invariance and to make the scalar field explicit. We show how to apply this
formalism to gravity and cosmology and we reproduce the detailed analysis of
the action in the ADM variables. We also review some basic applications to
inflation and dark energy.


title: Shintani cocycles of p-adic measures

abstract:
  We apply the constructions of "The p-adic Shintani cocycle" to the Shintani
cocycle of Charollois-Dasgupta-Greenberg, obtaining cocycles on arithmetic
subgroups of GL_n(Q$ valued in maps from "deformation vectors" R^n-Q^n to
p-adic measures.


title:
Metal-insulator transition at the LaAlO3/SrTiO3 interface revisited: A
  hybrid functional study

abstract:
  We investigate the electronic properties of the LaAlO3/SrTiO3 interface using
density functional theory. In contrast to previous studies, which relied on
(semi-)local functionals and the GGA+U method, we here use a recently developed
hybrid functional to determine the electronic structure. This approach offers
the distinct advantage of accessing both the metallic and insulating
multilayers on a parameter-free equal footing. As compared to calculations
based on semilocal GGA functionals, our hybrid functional calculations lead to
a considerably increased band gap for the insulating systems. The details of
the electronic structure show substantial deviations from those obtained by GGA
calculations. This casts severe doubts on all previous results based on
semilocal functionals. In particular, corrections using rigid band shifts
("scissors operator") cannot lead to valid results.


title: Long Range Surface Plasmons in Multilayer Structures

abstract:
  We present a new strategy, based on a Fresnel coefficient pole analysis, for
designing an asymmetric multilayer structure that supports long range surface
plasmons (LRSP). We find that the electric field intensity in the metal layer
of a multilayer LRSP structure can be even slightly smaller than in the metal
layer of the corresponding symmetric LRSP structure, minimizing absorption
losses and resulting in LRSP propagation lengths up to 2mm. With a view towards
biosensing applications, we also present semi-analytic expressions for a
standard surface sensing parameter in arbitrary planar resonant structures, and
in particular show that for an asymmetric structure consisting of a gold film
deposited on a multilayer of SiO2 and TiO2 a surface sensing parameter G =
1.28(1/nm) can be achieved.


title:
The Closest Point Method and multigrid solvers for elliptic equations on
  surfaces

abstract:
  Elliptic partial differential equations are important both from application
and analysis points of views. In this paper we apply the Closest Point Method
to solving elliptic equations on general curved surfaces. Based on the closest
point representation of the underlying surface, we formulate an embedding
equation for the surface elliptic problem, then discretize it using standard
finite differences and interpolation schemes on banded, but uniform Cartesian
grids. We prove the convergence of the difference scheme for the Poisson's
equation on a smooth closed curve. In order to solve the resulting large sparse
linear systems, we propose a specific geometric multigrid method in the setting
of the Closest Point Method. Convergence studies both in the accuracy of the
difference scheme and the speed of the multigrid algorithm show that our
approaches are effective.


title:
Near Linear Time Approximation Schemes for Uncapacitated and Capacitated
  b--Matching Problems in Nonbipartite Graphs

abstract:
  We present the first near optimal approximation schemes for the
  maximum weighted (uncapacitated or capacitated) $b$--matching
  problems for non-bipartite graphs that run in time (near) linear in
  the number of edges. For any $\delta>3/\sqrt{n}$ the algorithm
  produces a $(1-\delta)$ approximation in $O(m \poly(\delta^{-1},\log
  n))$ time. We provide fractional solutions for the standard linear
  programming formulations for these problems and subsequently also
  provide (near) linear time approximation schemes
  for rounding the fractional solutions.
  Through these problems as a vehicle, we also present several ideas
  in the context of solving linear programs approximately using fast
  primal-dual algorithms. First, even though the dual of these
  problems have exponentially many variables and an efficient exact
  computation of dual weights is infeasible, we show that we can
  efficiently compute and use a sparse approximation of the dual
  weights using a combination of (i) adding perturbation to the
  constraints of the polytope and (ii) amplification followed by
  thresholding of the dual weights. Second, we show that
  approximation algorithms can be used to reduce the width of the
  formulation, and faster convergence.


title:
HERMES: a Monte Carlo Code for the Propagation of Ultra-High Energy
  Nuclei

abstract:
  Although the recent experimental efforts to improve the observation of
Ultra-High Energy Cosmic Rays (UHECRs) above $10^{18}$ eV, the origin and the
composition of such particles is still unknown. In this work, we present the
novel Monte Carlo code (HERMES) simulating the propagation of UHE nuclei, in
the energy range between $10^{16}$ and $10^{22}$ eV, accounting for propagation
in the intervening extragalactic and Galactic magnetic fields and nuclear
interactions with relic photons of the extragalactic background radiation. In
order to show the potential applications of HERMES for astroparticle studies,
we estimate the expected flux of UHE nuclei in different astrophysical
scenarios, the GZK horizons and we show the expected arrival direction
distributions in the presence of turbulent extragalactic magnetic fields. A
stable version of HERMES will be released in the next future for public use
together with libraries of already propagated nuclei to allow the community to
perform mass composition and energy spectrum analysis with our simulator.


title: Local universality of zeroes of random polynomials

abstract:
  In this paper, we establish some local universality results concerning the
correlation functions of the zeroes of random polynomials with independent
coefficients. More precisely, consider two random polynomials $f =\sum_{i=1}^n
c_i \xi_i z^i$ and $\tilde f =\sum_{i=1}^n c_i \tilde \xi_i z^i$, where the
$\xi_i$ and $\tilde \xi_i$ are iid random variables that match moments to
second order, the coefficients $c_i$ are deterministic, and the degree
parameter $n$ is large. Our results show, under some light conditions on the
coefficients
  $c_i$ and the tails of $\xi_i, \tilde \xi_i$, that the correlation functions
of the zeroes of $f$ and $\tilde f$ are approximately the same. As an
application, we give some answers to the classical question `"How many zeroes
of a random polynomials are real?" for several classes of random polynomial
models.
  Our analysis relies on a general replacement principle, motivated by some
recent work in random matrix theory. This principle enables one to compare the
correlation functions of two random functions $f$ and $\tilde f$ if their log
magnitudes $\log |f|, \log|\tilde f|$ are close in distribution, and if some
non-concentration bounds are obeyed.


title:
A Relation Between the Warm Neutral and Ionized Media Observed in the
  Canadian Galactic Plane Survey

abstract:
  We report on a comparison between 21 cm rotation measure (RM) and the
optically-thin atomic hydrogen column density (N_HI) measured towards
unresolved extragalactic sources in the Galactic plane of the northern sky. HI
column densities integrated to the Galactic edge are measured immediately
surrounding each of nearly 2000 sources in 1-arcminute 21 cm line data, and are
compared to RMs observed from polarized emission of each source. RM data are
binned in column-density bins 4x10^20 cm^-2 wide, and one observes a strong
relationship between the number of hydrogen atoms in a 1 cm^2 column through
the plane and the mean RM along the same line-of-sight and path length. The
relationship is linear over one order of magnitude (from 0.8-14x10^21 atoms
cm^-2) of column densities, with a constant RM/N_HI -23.2+/-2.3 rad m^-2/10^21
atoms cm^-2, and a positive RM of 45.0+/-13.8 rad m^-2 in the presence of no
atomic hydrogen. This slope is used to calculate a mean volume-averaged
magnetic field in the 2nd quadrant of <B_||>~1.0+/-0.1 micro-Gauss directed
away from the Sun, assuming an ionization fraction of 8% (consistent with the
WNM). The remarkable consistency between this field and <B>=1.2 micro-Gauss
found with the same RM sources and a Galactic model of dispersion measures
suggests that electrons in the partially ionized WNM are mainly responsible for
pulsar dispersion measures, and thus the partially-ionized WNM is the dominant
form of the magneto-ionic interstellar medium.


title:
Access to Data and Number of Iterations: Dual Primal Algorithms for
  Maximum Matching under Resource Constraints

abstract:
  In this paper we consider graph algorithms in models of computation where the
space usage (random accessible storage, in addition to the read only input) is
sublinear in the number of edges $m$ and the access to input data is
constrained. These questions arises in many natural settings, and in particular
in the analysis of MapReduce or similar algorithms that model constrained
parallelism with sublinear central processing. In SPAA 2011, Lattanzi etal.
provided a $O(1)$ approximation of maximum matching using $O(p)$ rounds of
iterative filtering via mapreduce and $O(n^{1+1/p})$ space of central
processing for a graph with $n$ nodes and $m$ edges.
  We focus on weighted nonbipartite maximum matching in this paper. For any
constant $p>1$, we provide an iterative sampling based algorithm for computing
a $(1-\epsilon)$-approximation of the weighted nonbipartite maximum matching
that uses $O(p/\epsilon)$ rounds of sampling, and $O(n^{1+1/p})$ space. The
results extends to $b$-Matching with small changes. This paper combines
adaptive sketching literature and fast primal-dual algorithms based on relaxed
Dantzig-Wolfe decision procedures. Each round of sampling is implemented
through linear sketches and executed in a single round of MapReduce. The paper
also proves that nonstandard linear relaxations of a problem, in particular
penalty based formulations, are helpful in mapreduce and similar settings in
reducing the adaptive dependence of the iterations.


title:
Unruh Effect under Non-equilibrium conditions: Oscillatory motion of an
  Unruh-DeWitt detector

abstract:
  The Unruh effect refers to the thermal fluctuations a detector experiences
while undergoing linear motion with uniform acceleration in a Minkowski vacuum.
This thermality can be demonstrated by tracing the vacuum state of the field
over the modes beyond the accelerated detector's event horizon. However, the
event horizon is well-defined only if the detector moves with eternal uniform
linear acceleration. This idealized condition cannot be fulfilled in realistic
situations when the motion unavoidably involves periods of non-uniform
acceleration. Many experimental proposals to test the Unruh effect are of this
nature. Often circular or oscillatory motion, which lacks an obvious geometric
description, is considered in such proposals. The proper perspective for
theoretically going beyond, or experimentally testing, the Unruh-Hawking effect
in these more general conditions has to be offered by concepts and techniques
in non-equilibrium quantum field theory. In this paper we provide a detailed
analysis of how an Unruh-DeWitt detector undergoing oscillatory motion responds
to the fluctuations of a quantum field. Numerical results for the late-time
temperatures of the oscillating detector are presented. We comment on the
digressions of these results from what one would obtain from a naive
application of Unruh's result.


title:
Two-dimensional electron gas in a modulation-doped SrTiO3/Sr(Ti,Zr)O3
  heterostructure

abstract:
  A two-dimensional electron gas (2DEG) in SrTiO3 is created via modulation
doping by interfacing undoped SrTiO3 with a wider-band-gap material,
SrTi1-xZrxO3, that is doped n-type with La. All layers are grown using hybrid
molecular beam epitaxy. Using magnetoresistance measurements, we show that
electrons are transferred into the SrTiO3, and a 2DEG is formed. In particular,
Shubnikov-de Haas oscillations are shown to depend only on the perpendicular
magnetic field. Experimental Shubnikov-de Haas oscillations are compared with
calculations that assume multiple occupied subbands.


title: Incorporating the Hayflick Limit into a model of Telomere Dynamics

abstract:
  A model of telomere dynamics is proposed and examined. Our model, which
extends a previously introduced two-compartment model that incorporates stem
cells as progenitors of new cells, imposes the Hayflick Limit, the maximum
number of cell divisions that are possible. This new model leads to cell
populations for which the average telomere length is not necessarily a
monotonically decreasing function of time, in contrast to previously published
models. We provide a phase diagram indicating where such results would be
expected. In addition, qualitatively different results are obtained for the
evolution of the total cell population. Last, in comparison to available
leukocyte baboon data, this new model is shown to provide a better fit to
biological data.


title: Reeb-Thurston stability for symplectic foliations

abstract:
  We prove a version the local Reeb-Thurston stability theorem for symplectic
foliations.


title:
The obstacle problem for subelliptic non-divergence form operators on
  homogeneous groups

abstract:
  The main result established in this paper is the existence and uniqueness of
strong solutions to the obstacle problem for a class of subelliptic operators
in non-divergence form. The operators considered are structured on a set of
smooth vector fields in R^n; X = \{X_0, X_1, ...,X_q\}, q \le n, satisfying
H\"ormanders finite rank condition. In this setting, X_0 is a lower order term
while {X1, ...,X_q} are building blocks of the subelliptic part of the
operator. In order to prove this, we establish an embedding theorem under the
assumption that the set {X_0, X_1, ...,X_q} generates a homogeneous Lie group.
Furthermore, we prove that any strong solution belongs to a suitable class of
H\"older continuous functions.


title: Bell's Theorem, Accountability and Nonlocality

abstract:
  Bell's theorem is a fundamental theorem in physics concerning the
incompatibility between some correlations predicted by quantum theory and a
large class of physical theories. In this paper, we introduce the hypothesis of
accountability, which demands that it is possible to explain the correlations
of the data collected in many runs of a Bell experiment in terms of what
happens in each single run. Under this assumption, and making use of a recent
result by Colbeck and Renner [Nat. Commun. 2, 411 (2011)], we then show that
any nontrivial account of these correlations in the form of an extension of
quantum theory must violate parameter independence. Moreover, we analyze the
violation of outcome independence of quantum mechanics and show that it is also
a manifestation of nonlocality.


title:
What does one measure, when one measures the arrival times of a quantum
  particle?

abstract:
  What is the right statistics for the measurements of arrival times of a
quantum particle? Although this question is very old, it is still open. Usual
experiments are performed in far-field regime and this question becomes
unimportant, as a semiclassical analysis suffices. Nevertheless, the
development in the detector technology will soon allow for near-field
investigations, thus a better understanding of arrival time measurements is
needed. Since outcomes of quantum measurements are always described by POVMs,
various arrival time POVMs have been proposed. On the other hand many
physicists would agree that the arrival time statistics is given by the quantum
flux. This urges the question whether a POVM exists, which agrees approximately
with the quantum flux values on a reasonable set of wave functions. We answer
this question negatively for a very natural set of wave functions, but we
remark that the answer is very sensitive to the choice of the set, and provide
evidence for the existence of a POVM that agrees with the quantum flux on a
more restrictive set.


title: Asymmetric Exclusion Process with Global Hopping

abstract:
  We study a one-dimensional totally asymmetric simple exclusion process with
one special site from which particles fly to any empty site (not just to the
neighboring site). The system attains a non-trivial stationary state with
density profile varying over the spatial extent of the system. The density
profile undergoes a non-equilibrium phase transition when the average density
passes through the critical value 1-1/[4(1-ln 2)]=0.185277..., viz. in addition
to the discontinuity in the vicinity of the special site, a shock wave is
formed in the bulk of the system when the density exceeds the critical density.


title:
Viscous Evolution and Photoevaporation of Circumstellar Disks due to
  External FUV Radiation Fields

abstract:
  This paper explores the effects of FUV radiation fields from external stars
on circumstellar disk evolution. Disks residing in young clusters can be
exposed to extreme levels of FUV flux from nearby OB stars, and observations
show that disks in such environments are being actively photoevaporated.
Typical FUV flux levels can be factors of \sim 10^{2} - 10^{4} higher than the
interstellar value. These fields are effective in driving mass loss from
circumstellar disks because they act at large radial distance from the host
star, i.e., where most of the disk mass is located, and where the gravitational
potential well is shallow. We combine viscous evolution (an \alpha-disk model)
with an existing FUV photoevaporation model to derive constraints on disk
lifetimes, and to determine disk properties as functions of time, including
mass loss rates, disk masses, and radii. We also consider the effects of X-ray
photoevaporation from the host star using an existing model, and show that for
disks around solar-mass stars, externally-generated FUV fields are often the
dominant mechanism in depleting disk material. For sufficiently large
viscosities, FUV fields can efficiently photoevaporate disks over the entire
range of parameter space. Disks with viscosity parameter \alpha = 10^{-3} are
effectively dispersed within 1-3 Myr; for higher viscosities (\alpha = 10^{-2})
disks are dispersed within \sim 0.25 - 0.5 Myr. Furthermore, disk radii are
truncated to less than \sim100 AU, which can possibly affect the formation of
planets. Our model predictions are consistent with the range of observed masses
and radii of proplyds in the Orion Nebula Cluster.


title:
Density-Functional theory, finite-temperature classical maps, and their
  implications for foundational studies of quantum systems

abstract:
  The advent of the Hohenberg-Kohn theorem in 1964, its extension to finite-T,
Kohn-Sham theory, and relativistic extensions provide the well-established
formalism of density-functional theory (DFT). This theory enables the
calculation of all static properties of quantum systems {\it without} the need
for an n-body wavefunction \psi. DFT uses the one-body density distribution
instead of \psi. The more recent time-dependent formulations of DFT attempt to
describe the time evolution of quantum systems without using the time-dependent
wavefunction. Although DFT has become the standard tool of condensed-matter
computational quantum mechanics, its foundational implications have remained
largely unexplored. While all systems require quantum mechanics (QM) at T=0,
the pair-distribution functions (PDFs) of such quantum systems have been
accurately mapped into classical models at effective finite-T, and using
suitable non-local quantum potentials (e.g., to mimic Pauli exclusion effects).
These approaches shed light on the quantum \to hybrid \to classical models, and
provide a new way of looking at the existence of non- local correlations
without appealing to Bell's theorem. They also provide insights regarding
Bohmian mechanics. Furthermore, macroscopic systems even at 1 Kelvin have de
Broglie wavelengths in the micro-femtometer range, thereby eliminating
macroscopic cat states, and avoiding the need for {\it ad hoc} decoherence
models.


title: PURIFY: a new approach to radio-interferometric imaging

abstract:
  In a recent article series, the authors have promoted convex optimization
algorithms for radio-interferometric imaging in the framework of compressed
sensing, which leverages sparsity regularization priors for the associated
inverse problem and defines a minimization problem for image reconstruction.
This approach was shown, in theory and through simulations in a simple discrete
visibility setting, to have the potential to outperform significantly CLEAN and
its evolutions. In this work, we leverage the versatility of convex
optimization in solving minimization problems to both handle realistic
continuous visibilities and offer a highly parallelizable structure paving the
way to significant acceleration of the reconstruction and high-dimensional data
scalability. The new algorithmic structure promoted relies on the
simultaneous-direction method of multipliers (SDMM), and contrasts with the
current major-minor cycle structure of CLEAN and its evolutions, which in
particular cannot handle the state-of-the-art minimization problems under
consideration where neither the regularization term nor the data term are
differentiable functions. We release a beta version of an SDMM-based imaging
software written in C and dubbed PURIFY (http://basp-group.github.io/purify/)
that handles various sparsity priors, including our recent average sparsity
approach SARA. We evaluate the performance of different priors through
simulations in the continuous visibility setting, confirming the superiority of
SARA.


title:
Review on exact and perturbative deformations of the Einstein-Straus
  model: uniqueness and rigidity results

abstract:
  The Einstein-Straus model consists of a Schwarzschild spherical vacuole in a
Friedman-Lema\^{\i}tre-Robertson-Walker (FLRW) dust spacetime (with or without
\Lambda). It constitutes the most widely accepted model to answer the question
of the influence of large scale (cosmological) dynamics on local systems. The
conclusion drawn by the model is that there is no influence from the cosmic
background, since the spherical vacuole is static. Spherical generalizations to
other interior matter models are commonly used in the construction of lumpy
inhomogeneous cosmological models. On the other hand, the model has proven to
be reluctant to admit non-spherical generalizations. In this review, we
summarize the known uniqueness results for this model. These seem to indicate
that the only reasonable and realistic non-spherical deformations of the
Einstein-Straus model require perturbing the FLRW background. We review results
about linear perturbations of the Einstein-Straus model, where the
perturbations in the vacuole are assumed to be stationary and axially symmetric
so as to describe regions (voids in particular) in which the matter has reached
an equilibrium regime.


title: Automorphic forms for triangle groups

abstract:
  For triangle groups, the (quasi-)automorphic forms are known just as
explicitly as for the modular group SL$(2,\bbZ)$. We collect these expressions
here, and then interpret them using the Halphen differential equation. We study
the arithmetic properties of their Fourier coefficients at cusps and Taylor
coefficients at elliptic fixed-points --- in both cases integrality is related
to the arithmeticity of the triangle group. As an application of our formulas,
we provide an explicit modular interpretation of periods of 14 families of
Calabi-Yau threefolds over the thrice-punctured sphere.


title:
A continuum theory of phase separation kinetics for active Brownian
  particles

abstract:
  Active Brownian particles (ABPs), when subject to purely repulsive
interactions, are known to undergo activity-induced phase separation broadly
resembling an equilibrium (attraction-induced) gas-liquid coexistence. Here we
present an accurate continuum theory for the dynamics of phase-separating ABPs,
derived by direct coarse-graining, capturing leading-order density gradient
terms alongside an effective bulk free energy. Such gradient terms do not obey
detailed balance; yet we find coarsening dynamics closely resembling that of
equilibrium phase separation. Our continuum theory is numerically compared to
large-scale direct simulations of ABPs and accurately accounts for domain
growth kinetics, domain topologies and coexistence densities.


title:
Electron Transport Properties of Graphene-Graphyne-Graphene Transistors:
  First Principles Study

abstract:
  A novel nanoelectronic device is constructed by graphyne that is robustly
connected between graphene electrodes, where graphyne is composed of hexagonal
carbon rings and carbon chains. Owing to similarities between the bond lengths
and unit cell shapes of graphene and graphyne, they have perfectly matched
interfacial structure at periodic locations, enabling the facilitated charge
transfer and heterostructural stability. Using a combined nonequilibrium
Green's function and density functional theory formalism, we have
systematically investigated the electron transport properties of
graphene-graphyne-graphene field effect transistors (FETs) by varying the
graphyne size and the carbon chain length. These devices exhibit excellent
switching behaviors with ON/OFF ratios on the order of 10^2-10^3. The ON/OFF
ratio increases as either of the graphyne size or the carbon chain length
increases. Noticeably, these devices sustain good FET features even at the
small graphyne size of 8.5 A, yielding ON/OFF ratio of 650 and transmission
energy gap of 0.8 eV, which suggests their potential applications for
fabricating highly-integrated circuits at the level comparable to molecular
devices. Their boron-nitrides analogues show similar qualitative behaviors for
the changes of the graphyne size and bias voltage, but they show higher ON/OFF
ratios for the smaller chain length in contrast to graphyne TFTs.


title:
Evolutionary games with facilitators: When does selection favor
  cooperation?

abstract:
  We study the combined influence of selection and random fluctuations on the
evolutionary dynamics of two-strategy ("cooperation" and "defection") games in
populations comprising cooperation facilitators. The latter are individuals
that support cooperation by enhancing the reproductive potential of cooperators
relative to the fitness of defectors. By computing the fixation probability of
a single cooperator in finite and well-mixed populations that include a fixed
number of facilitators, and by using mean field analysis, we determine when
selection promotes cooperation in the important classes of prisoner's dilemma,
snowdrift and stag-hunt games. In particular, we identify the circumstances
under which selection favors the replacement and invasion of defection by
cooperation. Our findings, corroborated by stochastic simulations, show that
the spread of cooperation can be promoted through various scenarios when the
density of facilitators exceeds a critical value whose dependence on the
population size and selection strength is analyzed. We also determine under
which conditions cooperation is more likely to replace defection than vice
versa.
  Keywords: Evolutionary games; dynamics of cooperation; social dilemmas;
fixation; population dynamics.

categories: q-bio.PE cond-mat.stat-mech nlin.AO physics.soc-ph


title:
The discrepancy between dynamical and stellar masses in massive compact
  galaxies traces non-homology

abstract:
  For many massive compact galaxies, their dynamical masses ($M_\mathrm{dyn}
\propto \sigma^2 r_\mathrm{e}$) are lower than their stellar masses
($M_\star$). We analyse the unphysical mass discrepancy $M_\star /
M_\mathrm{dyn} > 1$ on a stellar-mass-selected sample of early-type galaxies
($M_\star \gtrsim 10^{11} \ \mathrm{M_\odot}$) at redshifts $z \sim 0.2$ to $z
\sim 1.1$. We build stacked spectra for bins of redshift, size and stellar
mass, obtain velocity dispersions, and infer dynamical masses using the virial
relation $M_\mathrm{dyn} \equiv K \ \sigma_\mathrm{e}^2 r_\mathrm{e} / G$ with
$K = 5.0$; this assumes homology between our galaxies and nearby massive
ellipticals. Our sample is completed using literature data, including
individual objects up to $z \sim 2.5$ and a large local reference sample from
the Sloan Digital Sky Survey (SDSS). We find that, at all redshifts, the
discrepancy between $M_\star$ and $M_\mathrm{dyn}$ grows as galaxies depart
from the present-day relation between stellar mass and size: the more compact a
galaxy, the larger its $M_\star / M_\mathrm{dyn}$. Current uncertainties in
stellar masses cannot account for values of $M_\star / M_\mathrm{dyn}$ above 1.
Our results suggest that the homology hypothesis contained in the
$M_\mathrm{dyn}$ formula above breaks down for compact galaxies. We provide an
approximation to the virial coefficient $K \sim 6.0 \left[ r_\mathrm{e} /
(3.185 \ \mathrm{kpc}) \right]^{-0.81} \left[ M_\star / (10^{11} \
\mathrm{M_\odot}) \right]^{0.45}$, which solves the mass discrepancy problem. A
rough approximation to the dynamical mass is given by $M_\mathrm{dyn} \sim
\left[ \sigma_\mathrm{e} / (200 \ \mathrm{km \ s^{-1}}) \right]^{3.6} \left[
r_\mathrm{e} / (3 \ \mathrm{kpc}) \right]^{0.35} 2.1 \times 10^{11} \
\mathrm{M_\odot}$.


title:
Modeling Statistical Properties of Solar Active Regions through DNS of
  3D-MHD Turbulence

abstract:
  Statistical properties of the Sun's photospheric turbulent magnetic field,
especially those of the Active Regions (ARs), have been studied using the
line-of-sight data from magnetograms taken by SOHO and several other
instruments (see e.g. Abramenko et al (2002, 2003),Abramenko and Yurchyshyn
(2010)). This includes structure functions and their exponents, flatness curves
and correlation functions. In these works, the dependence of structure function
exponents ($\zeta_p$) of the order of the structure functions ($\it{p}$) was
modeled using a non-intermittent K41 model. It is now well known that the ARs
are highly turbulent and are associated with strong intermittent events. In
this paper we compare some of the observations from Abramenko et al (2003) with
the log-Poisson model (Biskamp 2003) used for modeling intermittent MHD
turbulent flows. Next, we analyze the structure function data obtained from the
direct numerical simulations (DNS) of homogeneous, incompressible 3D-MHD
turbulence in three cases: sustained by forcing, freely decaying and a flow
initially driven and later allowed to decay (case 3). The respective DNS
replicate the properties seen in the plots of $\zeta_p$ against $\it{p}$ of
ARs. We also reproduce the trends and changes observed in intermittency in
flatness [Abramenko and Yurchyshyn (2010)] and correlation functions [Abramenko
et al (2003)] of ARs. It is suggested from this analysis that an AR in the
onset phase of a flare can be treated as a forced 3D-MHD turbulent system in
its simplest form and that the flaring stage is representative of decaying
3D-MHD turbulence. It is also inferred that significant changes in
intermittency from the initial onset phase of a flare to its final peak flaring
phase, are related to the time taken by the system to reach the initial onset
phase.

categories: astro-ph.SR physics.flu-dyn physics.geo-ph physics.space-ph


title:
J/{\psi},{\Upsilon}(1S) and {\chi}b(3p) Production Measurement with the
  ATLAS Detector

abstract:
  The J/{\psi} and {\Upsilon}(1S) production cross-sections are measured in
proton-proton collisions using the ATLAS detector at the LHC. Differential
cross-sections are measured as a function of transverse momentum and rapidity.
Results are compared to QCD predictions. A new {\chi}b state has been observed
though radiative transitions to the {\Upsilon}(1S) and {\Upsilon}(2S) states.


title: Evidence for flow in pPb collisions at 5 TeV from v2 mass splitting

abstract:
  We show that a fluid dynamical scenario describes quantitatively the observed
mass splitting of the elliptical flow coefficients v2 for pions, kaons, and
protons. This provides a strong argument in favor of the existence of a fluid
dynamical expansion in pPb collisions at 5TeV.


title:
A Smart Wizard System Suitable for Use With Internet Mobile Devices to
  Adjust Personal Information Privacy Settings

abstract:
  The privacy of personal information is an important issue affecting the
confidence of internet users. The widespread adoption of online social networks
and access to these platforms using mobile devices has encouraged developers to
make the systems and interfaces acceptable to users who seek privacy. The aim
of this study is to test a wizard that allows users to control the sharing of
personal information with others. We also assess the concerns of users in terms
of such sharing such as whether to hide personal data in current online social
network accounts. Survey results showed the wizard worked very well and that
females concealed more personal information than did males. In addition, most
users who were concerned about misuse of personal information hid those items.
The results can be used to upgrade current privacy systems or to design new
systems that work on mobile internet devices. The system can also be used to
save time when setting personal privacy settings and makes users more aware of
items that will be shared with others.


title: Global Properties of Supersymmetric Theories and the Lens Space

abstract:
  We compute the supersymmetric partition function on L(r,1)xS^1, the lens
space index, for 4d gauge theories related by supersymmetric dualities and
involving non simply-connected groups. This computation is sensitive to the
global properties of the underlying gauge group and to discrete theta angle
parameters and thus distinguishes versions of dualities differing by such. We
explicitly discuss N=1 so(N_c) Seiberg dualities and N=4 su(N_c) S-dualities.


title: Stability constants and the homology of quasi-Banach spaces

abstract:
  We affirmatively solve the main problems posed by Laczkovich and Paulin in
\emph{Stability constants in linear spaces}, Constructive Approximation 34
(2011) 89--106 (do there exist cases in which the second Whitney constant is
finite while the approximation constant is infinite?) and by Cabello and
Castillo in \emph{The long homology sequence for quasi-Banach spaces, with
applications}, Positivity 8 (2004) 379--394 (do there exist Banach spaces $X,Y$
for which $\Ext(X,Y)$ is Hausdorff and non-zero?). In fact, we show that these
two problems are the same.


title: On the Bounded Approximation Property in Banach spaces

abstract:
  We prove that the kernel of a quotient operator from an $\mathcal L_1$-space
onto a Banach space $X$ with the Bounded Approximation Property (BAP) has the
BAP. This completes earlier results of Lusky --case $\ell_1$-- and Figiel,
Johnson and Pe\l czy\'nski --case $X^*$ separable. Given a Banach space $X$, we
show that if the kernel of a quotient map from some $\mathcal L_1$-space onto
$X$ has the BAP then every kernel of every quotient map from any $\mathcal
L_1$-space onto $X$ has the BAP. The dual result for $\mathcal L_\infty$-spaces
also hold: if for some $\mathcal L_\infty$-space $E$ some quotient $E/X$ has
the BAP then for every $\mathcal L_\infty$-space $E$ every quotient $E/X$ has
the BAP.


title:
Effect of D-Dbar mixing in the extraction of gamma with B- -> D0 K- and
  B- -> D0 pi- decays

abstract:
  We examine the impact of D-Dbar mixing in the extraction of the angle gamma
of the unitarity triangle with B- ->D(*)K(*)- and B- ->D(*)pi- decays. We point
out that the leading corrections, linear in the small mixing parameters x=Delta
m/Gamma and y=Delta Gamma/2Gamma, depend on how the signal selection efficiency
varies as a function of the D proper time, and we estimate the scale factor in
a simplified case. We note that the charm mixing effect is suppressed in the
GLW method. We discuss the case where the leading corrections become quadratic
in x and y, and we point out some limitations of this scenario. We compute the
bias Delta_gamma when D-Dbar mixing is ignored in the rates of B- ->D(*)K(*)-
but not in the measurement of the D decay parameters. We find |Delta_gamma|<~1
deg for all B- ->D(*)K(*)- decays, limited by the measured value of the strong
phase difference between the b-> u cbar s and b->c ubar s decay amplitudes. The
effect in B- ->D(*)pi- decays cannot be neglected.


title: Thick coverings for the unit ball of a Banach space

abstract:
  We study the behaviour of Whitley's thickness constant of a Banach space with
respect to $\ell_p$-products and we compute it for classical $L_p$-spaces.


title: On Uniformly finitely extensible Banach spaces

abstract:
  We continue the study of Uniformly Finitely Extensible Banach spaces (in
short, UFO) initiated in Moreno-Plichko, \emph{On automorphic Banach spaces},
Israel J. Math. 169 (2009) 29--45 and Castillo-Plichko, \emph{Banach spaces in
various positions.} J. Funct. Anal. 259 (2010) 2098-2138. We show that they
have the Uniform Approximation Property of Pe\l czy\'nski and Rosenthal and are
compactly extensible. We will also consider their connection with the
automorphic space problem of Lindenstrauss and Rosenthal --do there exist
automorphic spaces other than $c_0(I)$ and $\ell_2(I)$?-- showing that a space
all whose subspaces are UFO must be automorphic when it is Hereditarily
Indecomposable (HI), and a Hilbert space when it is either locally minimal or
isomorphic to its square. We will finally show that most HI --among them, the
super-reflexive HI space constructed by Ferenczi-- and asymptotically $\ell_2$
spaces in the literature cannot be automorphic.


title: On ultrapowers of Banach spaces of type $\mathscr L_\infty$

abstract:
  We prove that no ultraproduct of Banach spaces via a countably incomplete
ultrafilter can contain $c_0$ complemented. This shows that a "result" widely
used in the theory of ultraproducts is wrong. We then amend a number of results
whose proofs had been infected by that statement. In particular we provide
proofs for the following statements: (i) All $M$-spaces, in particular all
$C(K)$-spaces, have ultrapowers isomorphic to ultrapowers of $c_0$, as well as
all their complemented subspaces isomorphic to their square. (ii) No ultrapower
of the Gurari\u \i\ space can be complemented in any $M$-space. (iii) There
exist Banach spaces not complemented in any $C(K)$-space having ultrapowers
isomorphic to a $C(K)$-space.


title:
Uplink Linear Receivers for Multi-cell Multiuser MIMO with Pilot
  Contamination: Large System Analysis

abstract:
  Base stations with a large number of transmit antennas have the potential to
serve a large number of users at high rates. However, the receiver processing
in the uplink relies on channel estimates which are known to suffer from pilot
interference. In this work, making use of the similarity of the uplink received
signal in CDMA with that of a multi-cell multi-antenna system, we perform a
large system analysis when the receiver employs an MMSE filter with a pilot
contaminated estimate. We assume a Rayleigh fading channel with different
received powers from users. We find the asymptotic Signal to Interference plus
Noise Ratio (SINR) as the number of antennas and number of users per base
station grow large while maintaining a fixed ratio. Through the SINR expression
we explore the scenario where the number of users being served are comparable
to the number of antennas at the base station. The SINR explicitly captures the
effect of pilot contamination and is found to be the same as that employing a
matched filter with a pilot contaminated estimate. We also find the exact
expression for the interference suppression obtained using an MMSE filter which
is an important factor when there are significant number of users in the system
as compared to the number of antennas. In a typical set up, in terms of the
five percentile SINR, the MMSE filter is shown to provide significant gains
over matched filtering and is within 5 dB of MMSE filter with perfect channel
estimate. Simulation results for achievable rates are close to large system
limits for even a 10-antenna base station with 3 or more users per cell.


title: On the moduli space of spontaneously broken N = 8 supergravity

abstract:
  We analyze the moduli space of spontaneously broken N=8 supergravity theories
in 4 dimensions with classical Minkowski vacua. We find that all the known
classical vacua, as well as the several new ones we construct here, can be
connected by sending some of the moduli to their boundary values. We also show
that Cremmer-Scherk-Schwarz models can be viewed as special limits of more
general CSO* gaugings, which allow for non-Abelian residual symmetries on the
vacuum. Finally, we find that all the classical Minkowski vacua with fully
broken supersymmetry found so far are unstable with respect to 1-loop
corrections, which drive the effective potential to negative values.


title:
An Isomorphism between Scalar-Valued Modular Forms and Modular Forms for
  Weil Representations

abstract:
  In this note, we consider discriminant forms that are given by the norm form
of real quadratic fields and their induced Weil representations. We prove that
there exists an isomorphism between the space of vector-valued modular forms
for the Weil representations that are invariant under the action of the
automorphism group and the space of scalar-valued modular forms that satisfy
some epsilon-condition, with which we translate Borcherds's theorem of
obstructions to scalar-valued modular forms. In the end, we consider an example
in the case of level 12.


title: Associahedra via spines

abstract:
  An associahedron is a polytope whose vertices correspond to triangulations of
a convex polygon and whose edges correspond to flips between them. Using
labeled polygons, C. Hohlweg and C. Lange constructed various realizations of
the associahedron with relevant properties related to the symmetric group and
the classical permutahedron. We introduce the spine of a triangulation as its
dual tree together with a labeling and an orientation. This notion extends the
classical understanding of the associahedron via binary trees, introduces a new
perspective on C. Hohlweg and C. Lange's construction closer to J.-L. Loday's
original approach, and sheds light upon the combinatorial and geometric
properties of the resulting realizations of the associahedron. It also leads to
noteworthy proofs which shorten and simplify previous approaches.


title:
Local existence and non-explosion of solutions for stochastic fractional
  partial differential equations driven by multiplicative noise

abstract:
  In this paper we prove the local existence and uniqueness of solutions for a
class of stochastic fractional partial differential equations driven by
multiplicative noise. We also establish that for this class of equations adding
linear multiplicative noise provides a regularizing effect: the solutions will
not blow up with high probability if the initial data is sufficiently small, or
if the noise coefficient is sufficiently large. As applications our main
results are applied to various types of SPDE such as stochastic
reaction-diffusion equations, stochastic fractional Burgers equation,
stochastic fractional Navier-Stokes equation, stochastic quasi-geostrophic
equations and stochastic surface growth PDE.


title: Banach space projections and Petrov-Galerkin estimates

abstract:
  We sharpen the classic a priori error estimate of Babuska for Petrov-Galerkin
methods on a Banach space. In particular, we do so by (i) introducing a new
constant, called the Banach-Mazur constant, to describe the geometry of a
normed vector space; (ii) showing that, for a nontrivial projection $P$, it is
possible to use the Banach-Mazur constant to improve upon the naive estimate $
\| I - P \| \leq 1 + \| P \| $; and (iii) applying that improved estimate to
the Petrov-Galerkin projection operator. This generalizes and extends a 2003
result of Xu and Zikatanov for the special case of Hilbert spaces.


title:
A sufficient criterion for control of generalised error rates in
  multiple testing

abstract:
  Based on the work of Romano and Shaikh (2006) and Lehmann and Romano (2005)
we give a sufficient criterion for controlling generalised error rates for
arbitrarily dependent p-values. This criterion is formulated in terms of
matrices associated with the corresponding error rates and thus it is possible
to view the corresponding critical constants as solutions of sets of certain
linear inequalities. This property can in some cases be used to improve the
power of existing procedures by finding optimal solutions to an associated
linear programming problem.


title:
Common fixed points for pairs of mappings with variable contractive
  parameters

abstract:
  In this paper, we establish some common fixed point results for a new class
of pair of contractions mappings having functions as contractive parameters,
and satisfying certain commutative properties.


title:
An imperfect double: probing the physical origin of the low-frequency
  QPO and its harmonic in black hole binaries

abstract:
  We extract the spectra of the strong low-frequency quasi-periodic oscillation
(QPO) and its harmonic during the rising phase of an outburst in the black-hole
binary XTE J1550-564. We compare these frequency resolved spectra to the
time-averaged spectrum and the spectrum of the rapid (<0.1s) variability. The
spectrum of the time averaged emission can be described by a disc, a Compton
upscattered tail, and its reflection. The QPO spectrum contains no detectable
disc, and the Compton spectrum is generally harder than in the time averaged
emission, and shows less reflection, making it very similar to the spectrum of
the rapid variability. The harmonic likewise contains no detectable disc
component, but has a Compton spectrum which is systematically softer than the
QPO, softer even than the Compton tail in the time averaged emission. We
interpret these results in the context of the Lense-Thirring model for the QPO,
where a precessing hot flow replaces the inner disc, and the harmonic is
produced by the angular dependence of Compton scattering within the hot flow.
We extend these models to include stratification of the hot flow, so that it is
softer (lower optical depth) at larger radii closer to the truncated disc, and
harder (higher optical depth) in the innermost parts of the flow where the
rapid variability is produced. The different optical depth with radius gives
rise to different angular dependence of the Comptonised emission, weighting the
fundamental to the inner parts of the hot flow, and the harmonic to the outer.
This is the first model which can explain both the spectrum of the QPO and its
harmonic in a self consistent geometry.


title:
Constraining turbulence and conduction in the hot ICM through density
  perturbations

abstract:
  Using 3D high-resolution hydrodynamic simulations, tracking both electrons
and ions, we study the effects of turbulence and conduction in the hot
intracluster medium. We show how the power spectrum of the gas density
perturbations can accurately constrain both processes. The characteristic
amplitude of density perturbations is linearly related to the strength of
turbulence, i.e. the 3D Mach number, as A(k)_max = 0.25 M. The slope of A(k) in
turn reflects the level of conduction. In a non-conductive medium, subsonic
stirring motions advect density with a similar nearly Kolmogorov cascade.
Increasing conduction (via magnetic suppression f = 0.001-1) progressively
steepens the spectrum towards the Burgers-like regime. The turbulent Prandtl
number defines the dynamic similarity of the flow; at scales where Pt < 100,
the spectrum develops a significant decay. The transition is gentle for highly
suppressed conduction, f < 0.001, while sharp in the opposite regime. For
strong conductivity (f > 0.1), Pt ~ 100 occurs on spatial scales larger than
the injection scale. The velocity spectrum is instead not much affected by
conduction. The f > 0.1 regime affects the appearance of X-ray images, in which
Kelvin-Helmholtz and Rayleigh-Taylor rolls and filaments are washed out. In a
stratified system, weak/strong turbulence induces higher isobaric/adiabatic
fluctuations, while conduction forces both modes towards the intermediate
isothermal regime. We provide a general analytic fit which is applied to new
deep Chandra observations of Coma. The observed spectrum is best consistent
with strongly suppressed effective isotropic conduction, f = 0.001, and mild
subsonic turbulence, M = 0.45 (with injection at ~250 kpc). The low
conductivity corroborates the survival of sharp features in the ICM (cold
fronts, filaments, bubbles), and indicates that cooling flows may not be
balanced by conduction.


title:
Constraints on neutrino density and velocity isocurvature modes from
  WMAP-9 data

abstract:
  We use WMAP 9-year and other CMB data to constrain cosmological models where
the primordial perturbations have both an adiabatic and a (possibly correlated)
neutrino density (NDI), neutrino velocity (NVI), or cold dark matter density
(CDI) isocurvature component. For NDI and CDI we use both a phenomenological
approach, where primordial perturbations are parametrized in terms of
amplitudes at two scales, and a slow-roll two-field inflation approach, where
slow-roll parameters are used as primary parameters. For NVI we use only the
phenomenological approach, since it is difficult to imagine a connection with
inflation. We find that in the NDI and NVI cases larger isocurvature fractions
are allowed than in the corresponding models with CDI. For uncorrelated
perturbations, the upper limit to the primordial NDI (NVI) fraction is 24%
(20%) at k = 0.002 Mpc^{-1} and 28% (16%) at k = 0.01 Mpc^{-1}. For maximally
correlated (anticorrelated) perturbations, the upper limit to the NDI fraction
is 3.0% (0.9%). The nonadiabatic contribution to the CMB temperature variance
can be as large as 10% (-13%) for the NDI (NVI) modes. Bayesian model
comparison favors pure adiabatic initial mode over the mixed primordial
adiabatic and NDI, NVI, or CDI perturbations. At best, the betting odds for a
mixed model (uncorrelated NDI) are 1:3.4 compared to the pure adiabatic model.
For the phenomenological generally correlated mixed models the odds are about
1:100, whereas the slow-roll approach leads to 1:13 (NDI) and 1:51 (CDI).


title:
Joint analysis of cluster number counts and weak lensing power spectrum
  to correct for the super-sample covariance

abstract:
  A coherent over- or under-density contrast across a finite survey volume
causes an upward- or downward-fluctuation in the observed number of halos. This
fluctuation in halo number adds a significant co-variant scatter in the
observed amplitudes of weak lensing power spectrum at nonlinear, small scales
-- the so-called super-sample variance or the halo sample variance. In this
paper, we show that by measuring both the number counts of clusters and the
power spectrum in the same survey region, we can mitigate this loss of
information and significantly enhance the scientific return from the upcoming
surveys.
  First, using the halo model approach, we derive the cross-correlation between
the halo number counts and the weak lensing power spectrum, taking into account
the super-sample covariance effect, which well matches the distributions
measured from 1000 realizations for a Lambda-dominated cold dark matter model.
Then we show that adding the observed number counts of massive halos with M>
10^14 Ms/h can significantly improve the information content of weak lensing
power spectrum, almost recovering the Gaussian information up to lmax~1000, if
the average mass profiles of the massive halos are known, which can be
estimated from stacked lensing. When combined with the halo number counts for M
> 3 or 1 x 10^14 Ms/h, the improvement is up to a factor of 1.4 or 2 at
lmax~1000 --2000, equivalent to a factor 2 or 4 times larger survey volume,
compared to the power spectrum measurement alone.


title: In Wino Veritas? Indirect Searches Shed Light on Neutralino Dark Matter

abstract:
  Indirect detection constraints on gamma rays (both continuum and lines) have
set strong constraints on wino dark matter. By combining results from Fermi-LAT
and HESS, we show that: light nonthermal wino dark matter is strongly excluded;
thermal wino dark matter is allowed only if the Milky Way dark matter
distribution has a significant (>~0.4 kpc) core; and for plausible NFW and
Einasto distributions the entire range of wino masses from 100 GeV up to 3 TeV
can be excluded. The case of light, nonthermal wino dark matter is particularly
interesting in scenarios with decaying moduli that reheat the universe to a low
temperature. Typically such models have been discussed for low reheating
temperatures, not far above the BBN bound of a few MeV. We show that
constraints on the allowed wino relic density push such models to higher
reheating temperatures and hence heavier moduli. Even for a flattened halo
model consisting of an NFW profile with constant-density core inside 1 kpc and
a density near the sun of 0.3 GeV/cm^3, for 150 GeV winos current data
constrains the reheat temperature to be above 1.4 GeV. As a result, for models
in which the wino mass is a loop factor below the gravitino mass, the data
favor moduli that are more than an order of magnitude heavier than the
gravitino. We discuss some of the sobering implications of this result for the
status of supersymmetry. We also comment on other neutralino dark matter
scenarios, in particular the case of mixed bino/higgsino dark matter. We show
that in this case, direct and indirect searches are complementary to each other
and could potentially cover most of the parameter space.


title: The Afterglow of GRB 130427A from 1 to 10^16 GHz

abstract:
  We present multiwavelength observations of the afterglow of GRB 130427A, the
brightest (in total fluence) gamma-ray burst of the past 29 years. Optical
spectroscopy from Gemini-North reveals the redshift of the GRB to be z=0.340,
indicating that its unprecedented brightness is primarily the result of its
relatively close proximity to Earth; the intrinsic luminosities of both the GRB
and its afterglow are not extreme in comparison to other bright GRBs. We
present a large suite of multiwavelength observations spanning from 300 s to
130 d after the burst and demonstrate that the afterglow shows relatively
simple, smooth evolution at all frequencies with no significant late-time
flaring or rebrightening activity. The entire dataset from 1 GHz to 10 GeV can
be modeled as synchrotron emission from a combination of reverse and forward
shocks in good agreement with the standard afterglow model, providing strong
support to the applicability of the underlying theory and clarifying the nature
of the GeV emission observed to last for minutes to hours following other very
bright GRBs. A tenuous, wind-stratified circumburst density profile is required
by the observations, suggesting a massive-star progenitor with a low mass-loss
rate, perhaps due to low metallicity. GRBs similar in nature to GRB 130427A,
inhabiting low-density media and exhibiting strong reverse shocks, are probably
not uncommon but may have been difficult to recognize in the past due to their
relatively faint late-time radio emission; more such events should be found in
abundance by the new generation of sensitive radio and millimeter instruments.


title:
zCOSMOS 20k: Satellite galaxies are the main drivers of environmental
  effects in the galaxy population at least to z~0.7

abstract:
  We explore the role of environment in the evolution of galaxies over
0.1<z<0.7 using the final zCOSMOS-bright data set. Using the red fraction of
galaxies as a proxy for the quenched population, we find that the fraction of
red galaxies increases with the environmental overdensity and with the stellar
mass, consistent with previous works. As at lower redshift, the red fraction
appears to be separable in mass and environment, suggesting the action of two
processes: mass and environmental quenching. The parameters describing these
appear to be essentially the same at z~0.7 as locally. We explore the relation
between red fraction, mass and environment also for the central and satellite
galaxies separately, paying close attention to the effects of impurities in the
central-satellite classification and using carefully constructed samples
matched in stellar mass. There is little evidence for a dependence of the red
fraction of centrals on overdensity. Satellites are consistently redder at all
overdensities, and the satellite quenching efficiency increases with
overdensity at 0.1<z<0.4. This is less marked at higher redshift, but both are
nevertheless consistent with the equivalent local measurements. At a given
stellar mass, the fraction of galaxies that are satellites also increases with
the overdensity. At a given overdensity and mass, the obtained relation between
the environmental quenching and the satellite fraction agrees well with the
satellite quenching efficiency, demonstrating that the environmental quenching
in the overall population is consistent with being entirely produced through
the satellite quenching process at least up to z=0.7. However, despite the
unprecedented size of our high redshift samples, the associated statistical
uncertainties are still significant and our statements should be understood as
approximations to physical reality, rather than physically exact formulae.


title:
Universal topological quantum computation from a superconductor/Abelian
  quantum Hall heterostructure

abstract:
  Non-Abelian anyons promise to reveal spectacular features of quantum
mechanics that could ultimately provide the foundation for a decoherence-free
quantum computer. A key breakthrough in the pursuit of these exotic particles
originated from Read and Green's observation that the Moore-Read quantum Hall
state and a (relatively simple) two-dimensional p+ip superconductor both
support so-called Ising non-Abelian anyons. Here we establish a similar
correspondence between the Z_3 Read-Rezayi quantum Hall state and a novel
two-dimensional superconductor in which charge-2e Cooper pairs are built from
fractionalized quasiparticles. In particular, both phases harbor Fibonacci
anyons that---unlike Ising anyons---allow for universal topological quantum
computation solely through braiding. Using a variant of Teo and Kane's
construction of non-Abelian phases from weakly coupled chains, we provide a
blueprint for such a superconductor using Abelian quantum Hall states
interlaced with an array of superconducting islands. Fibonacci anyons appear as
neutral deconfined particles that lead to a two-fold ground-state degeneracy on
a torus. In contrast to a p+ip superconductor, vortices do not yield additional
particle types yet depending on non-universal energetics can serve as a trap
for Fibonacci anyons. These results imply that one can, in principle, combine
well-understood and widely available phases of matter to realize non-Abelian
anyons with universal braid statistics. Numerous future directions are
discussed, including speculations on alternative realizations with fewer
experimental requirements.


title: Genuine hidden quantum nonlocality

abstract:
  The nonlocality of certain quantum states can be revealed by using local
filters before performing a standard Bell test. This phenomenon, known as
hidden nonlocality, has been so far demonstrated only for a restricted class of
measurements, namely projective measurements. Here we prove the existence of
genuine hidden nonlocality. Specifically, we present a class of two-qubit
entangled states, for which we construct a local model for the most general
local measurements (POVMs), and show that the states violate a Bell inequality
after local filtering. Hence there exist entangled states, the nonlocality of
which can be revealed only by using a sequence of measurements. Finally, we
show that genuine hidden nonlocality can be maximal. There exist entangled
states for which a sequence of measurements can lead to maximal violation of a
Bell inequality, while the statistics of non-sequential measurements is always
local.


title: The Local Hole revealed by galaxy counts and redshifts

abstract:
  The redshifts of ~250000 galaxies are used to study the Local Hole and its
associated peculiar velocities. The sample, compiled from 6dFGS and SDSS
provides wide sky coverage to a depth of ~300h-1Mpc. We have therefore examined
K and r limited galaxy redshift distributions and number counts to map the
local density field. Comparing observed galaxy n(z) distributions to
homogeneous models in three large regions of the high latitude sky, we find
evidence for under-densities ranging from ~4-40% in these regions to depths of
~150h-1Mpc with the deepest under-density being over the Southern Galactic cap.
Using the Galaxy and Mass Assembly (GAMA) survey we then establish the
normalisation of galaxy counts at fainter magnitudes and thus confirm that the
underdensity over all three fields at K<12.5 is ~15+-3%. Finally, we further
use redshift catalogues to map peculiar velocities over the same areas using
the average redshift - magnitude, zbar(m), technique of Soneira (1979). After
accounting for the direct effect of large-scale structure on zbar(m) we can
then search for peculiar velocities. Taking all three regions into
consideration the data reject at the ~4sigma level the idea that we have
recovered the CMB rest frame in the volume probed. There is therefore some
consistent evidence from counts and Hubble diagram for a local ~150h-1Mpc
underdensity that deeper counts and redshifts in the Northern Galactic cap
suggest may extend to ~300h-1Mpc.


title: Distorted Five-dimensional Electrically Charged Black Holes

abstract:
  We derive and study distorted, five-dimensional, electrically charged,
non-extremal black holes on the example of a static and "axisymmetric" black
hole distorted by external, electrically neutral matter.The solution satisfies
Einstein-Maxwell equations which admits an $\mathbb{R}^1\times U(1)\times U(1)$
isometry group. The inner horizon remains regular if the distortion fields are
finite and smooth at the outer horizon. There exists a certain duality
transformation between the inner and the outer horizon surfaces which links
surface gravity, electrostatic potential, and space-time curvature invariants
calculated at the black hole horizons. The product of the inner and outer
horizon areas depends only on the black hole's electric charge and the
geometric mean of the areas is the upper (lower) limit for the inner (outer)
horizon area. The horizon areas, electrostatic potential, and surface gravity
satisfy the Smarr formula. We formulated the zeroth and the first laws of
mechanics and thermodynamics of the distorted black hole and found a
correspondence between the global and local forms of the first law. To
illustrate the effect of distortion we consider the dipole-monopole and
quadrupole-quadrupole distortion fields. The relative change in the Kretschamnn
scalar due to the distortion is greater at the outer horizon than at the inner
one. Calculating the maximal proper time of free fall from the outer to the
inner horizons we show that the distortion can noticeably change the black hole
interior. The change depends on type and strength of distortion fields. In
particular, due to the types of distortion fields considered here the black
hole horizons can either come arbitrarily close to or move far from each other.


title:
More accurate and efficient bath spectral densities from
  super-resolution

abstract:
  Quantum transport and other phenomena are typically modeled by coupling the
system of interest to an environment, or bath, held at thermal equilibrium.
Realistic bath models are at least as challenging to construct as models for
the quantum systems themselves, since they must incorporate many degrees of
freedom that interact with the system on a wide range of timescales. Owing to
computational limitations, the environment is often modeled with simple
functional forms, with a few parameters fit to experiment to yield
semi-quantitative results. Growing computational resources have enabled the
construction of more realistic bath models from molecular dynamics (MD)
simulations. In this paper, we develop a numerical technique to construct these
atomistic bath models with better accuracy and decreased cost. We apply a novel
signal processing technique, known as super-resolution, combined with a
dictionary of physically-motivated bath modes to derive spectral densities from
MD simulations. Our approach reduces the required simulation time and provides
a more accurate spectral density than can be obtained via standard Fourier
transform methods. Moreover, the spectral density is provided as a convenient
closed-form expression which yields an analytic time-dependent bath kernel.
Exciton dynamics of the Fenna-Matthews-Olsen light-harvesting complex are
simulated with a second order time-convolutionless master equation, and
spectral densities constructed via super-resolution are shown to reproduce the
dynamics using only a quarter of the amount of MD data.


title:
Selective equilibration of spin and valley polarized quantum Hall edge
  states in graphene

abstract:
  We report on transport measurements of dual-gated, single-layer graphene
devices in the quantum Hall regime, allowing for independent control of the
filling factors in adjoining regions. Progress in device quality allows us to
study scattering between edge states when the four-fold degeneracy of the
Landau level is lifted by electron correlations, causing edge states to be spin
and/or valley polarized. In this new regime, we observe a dramatic departure
from the equilibration seen in more disordered devices: edge states with
opposite spins propagate without mixing. As a result, the degree of
equilibration inferred from transport can reveal the spin polarization of the
ground state at each filling factor. In particular, the first Landau level is
shown to be spin-polarized at half-filling, providing an independent
confirmation of a conclusion of Ref.[1]. The conductance in the bipolar regime
is strongly suppressed, indicating that co-propagating edge states, even with
the same spin, do not equilibrate along PN interfaces. We attribute this
behavior to the formation of an insulating nu=0 stripe at the PN interface.