title:
Shifted Laplacian based multigrid preconditioners for solving indefinite
  Helmholtz equations

abstract:
  Shifted Laplacian multigrid preconditioner has become a tool du jour for
solving highly indefinite Helmholtz equations. The idea is to add a complex
damping to the original Helmholtz operator and then apply a multigrid
processing to the resulting operator using it to precondition Krylov methods,
usually Bi-CGSTAB. Not only such preconditioning accelerates Krylov iterations,
but it does so more efficiently than the multigrid applied to original
Helmholtz equations. In this paper, we compare properties of the Helmholtz
operator with and without the shift and propose a new combination of the two.
Also applied here is a relaxation of normal equations that replaces diverging
linear schemes on some intermediate scales. Finally, an acceleration by the ray
correction is considered.


title: Asymptotic Behaviour of Pion--Pion Total Cross-Sections

abstract:
  We derive a sum rule which shows that the Froissart-Martin bound for the
asymptotic behaviour of the $\pi\pi$ total cross sections at high energies, if
modulated by the Lukaszuk-Martin coefficient of the leading $\log^2 s$
behaviour, cannot be an optimal bound in QCD. We next compute the total cross
sections for $\pi^+ \pi^-$, $\pi^{\pm} \pi^0$ and $\pi^0 \pi^0$ scattering
within the framework of the constituent chiral quark model (C$\chi$QM) in the
limit of a large number of colours $\Nc$ and discuss their asymptotic
behaviours. The same $\pi\pi$ cross sections are also discussed within the
general framework of Large-\Nc~QCD and we show that it is possible to make an
Ansatz for the isospin $I=1$ and $I=0$ spectrum which satisfy the
Froissart-Martin bound with coefficients which, contrary to the Lukaszuk-Martin
coefficient, are not singular in the chiral limit and have the correct
Large-\Nc~counting. We finally propose a simple phenomenological model which
matches the low energy behaviours of the $\sigma_{\pi^{\pm}\pi^0}^{\rm
total}(s)$ cross section predicted by the C$\chi$QM with the high energy
behaviour predicted by the Large-$\Nc$ Ansatz. The magnitude of these cross
sections at very high energies is of the order of those observed for the $pp$
and $p{\bar p}$ scattering total cross sections.


title:
Towards loss compensated and lasing terahertz metamaterials based on
  optically pumped graphene

abstract:
  It is evidenced by numerical calculations that optically pumped graphene is
suitable for compensating inherent loss in terahertz (THz) metamaterials. In a
first step, the complex conductivity of graphene under optical pumping is
calculated and the proper conditions for terahertz amplification in single
layer graphene are determined. It is shown that amplification in graphene
occurs for temperatures up to room temperature and for moderate pump
intensities when pumped at a telecommunication wavelength
$\lambda=1.5~\mathrm{\mu m}$. Furthermore, the amplification properties of
graphene are evaluated and discussed at a temperature as low as
$T=77~\mathrm{K}$ and a pump intensity $I=300~\mathrm{mW/mm^2}$ to investigate
the coupling between graphene and a plasmonic split ring resonator (SRR)
metamaterial. The contributions of ohmic and dielectric loss mechanisms are
studied by full wave simulations. As a result, it is found that the loss of a
split-ring resonator metamaterial can be compensated by optically stimulated
amplification in graphene. Moreover, it is shown that a hybrid material
consisting of asymmetric split-ring resonators and optically pumped graphene
can exceed the laser threshold condition and can emit coherent THz radiation at
minimum output power levels of $6 0~\mathrm{nW/mm^2}$. The use of optically
pumped graphene is well suited for loss compensation in THz metamaterials and
paves the way to new kinds of coherent THz sources.


title: $\lambda$-Toeplitz operators with analytic symbols

abstract:
  Let $\lambda$ be a complex number in the closed unit disc $\overline{\Bbb
D}$, and $\cal H$ be a separable Hilbert space with the orthonormal basis, say,
${\cal E}=\{e_n:n=0,1,2,\cdots\}$. A bounded operator $T$ on $\cal H$ is called
a {\em $\lambda$-Toeplitz operator} if $\langle
Te_{m+1},e_{n+1}\rangle=\lambda\langle Te_m,e_n\rangle$ (where
$\langle\cdot,\cdot\rangle$ is the inner product on $\cal H$). The subject
arises naturally as the "eigenoperators" of the map \[ \phi(A)=S^*AS \] on the
${\cal B}(\cal H)$, the space of bounded operators on $\cal H$, where $S$ is
the unilateral shift on $Se_n=e_{n+1}$.
  In this paper, we study the essential spectra for $\lambda$-Toeplitz
operators when $|\lambda|=1$, and we will use the results to determine the
spectra of certain weighted composition operators on Hardy spaces.


title:
Advanced Antenna Techniques and High Order Sectorization with Novel
  Network Tessellation for Enhancing Macro Cell Capacity in DC-HSDPA Network

abstract:
  Mobile operators commonly use macro cells with traditional wide beam antennas
for wider coverage in the cell, but future capacity demands cannot be achieved
by using them only. It is required to achieve maximum practical capacity from
macro cells by employing higher order sectorization and by utilizing all
possible antenna solutions including smart antennas. This paper presents
enhanced tessellation for 6-sector sites and proposes novel layout for
12-sector sites. The main target of this paper is to compare the performance of
conventional wide beam antenna, switched beam smart antenna, adaptive beam
antenna and different network layouts in terms of offering better received
signal quality and user throughput. Splitting macro cell into smaller micro or
pico cells can improve the capacity of network, but this paper highlights the
importance of higher order sectorization and advance antenna techniques to
attain high Signal to Interference plus Noise Ratio (SINR), along with improved
network capacity. Monte Carlo simulations at system level were done for Dual
Cell High Speed Downlink Packet Access (DC-HSDPA) technology with multiple
(five) users per Transmission Time Interval (TTI) at different Intersite
Distance (ISD). The obtained results validate and estimate the gain of using
smart antennas and higher order sectorization with proposed network layout.


title:
Spectral Renormalization Group for the Gaussian model and $\psi^4$
  theory on non-spatial networks

abstract:
  We implement the spectral renormalization group on different deterministic
non-spatial networks without translational invariance. We calculate the
thermodynamic critical exponents for the Gaussian model on the Cayley tree and
the diamond lattice, and find that they are functions of the spectral
dimension, $\tilde{d}$. The results are shown to be consistent with those from
exact summation and finite size scaling approaches. At $\tilde{d}=2$, the lower
critical dimension for the Ising universality class, the Gaussian fixed point
is stable with respect to a $\psi^4$ perturbation up to second order. However,
on generalized diamond lattices, non-Gaussian fixed points arise for
$2<\tilde{d}<4$.


title:
Globally strongly convex cost functional for a coefficient inverse
  problem

abstract:
  A Carleman Weight Function (CWF) is used to construct a new cost functional
for a Coefficient Inverse Problems for a hyperbolic PDE. Given a bounded set of
an arbitrary size in a certain Sobolev space, one can choose the parameter of
the CWF in such a way that the constructed cost functional will be strongly
convex on that set. Next, convergence of the gradient method, which starts from
an arbitrary point of that set, is established. Since restrictions on the size
of that set are not imposed, then this is the global convergence.


title:
On the minimal active-sterile neutrino mixing in seesaw type I mechanism
  with sterile neutrinos at GeV scale

abstract:
  Renewed interest in GeV-scale sterile neutrinos capable of explaining active
neutrino oscillations via see-saw type I mechanism has been expressed in
several proposals of direct searches. Given this activity we estimate the
minimal values of sterile-active mixing angles provided one, two, or three
sterile neutrinos are lighter than D-meson.


title:
A proof-of-principle quantum-optical experiment challenging the import
  of the 'no-signaling' theorem

abstract:
  We present, and mathematically describe, a proof-of-principle quantum-optical
experiment that seemingly enables superluminal signaling, contrary to the
import of the 'no-signaling' theorem.


title:
The role of planarity in connectivity problems parameterized by
  treewidth

abstract:
  For some years it was believed that for "connectivity" problems such as
Hamiltonian Cycle, algorithms running in time 2^{O(tw)}n^{O(1)} -called
single-exponential- existed only on planar and other sparse graph classes,
where tw stands for the treewidth of the n-vertex input graph. This was
recently disproved by Cygan et al. [FOCS 2011], Bodlaender et al. [ICALP 2013],
and Fomin et al. [SODA 2014], who provided single-exponential algorithms on
general graphs for essentially all connectivity problems that were known to be
solvable in single-exponential time on sparse graphs. In this article we
further investigate the role of planarity in connectivity problems
parameterized by treewidth, and convey that several problems can indeed be
distinguished according to their behavior on planar graphs. Known results from
the literature imply that there exist problems, like Cycle Packing, that cannot
be solved in time 2^{o(tw logtw)}n^{O(1)} on general graphs but that can be
solved in time 2^{O(tw)}n^{O(1)} when restricted to planar graphs. Our main
contribution is to show that there exist problems that can be solved in time
2^{O(tw logtw)}n^{O(1)} on general graphs but that cannot be solved in time
2^{o(tw logtw)}n^{O(1)} even when restricted to planar graphs. Furthermore, we
prove that Planar Cycle Packing and Planar Disjoint Paths cannot be solved in
time 2^{o(tw)}n^{O(1)}. The mentioned negative results hold unless the ETH
fails. We feel that our results constitute a first step in a subject that can
be further exploited.


title:
Riemann Zeta Function. Chi(s)via analytic Continuation inside an
  infinite Loop

abstract:
  The paper deals with the analytic entire function Chi(s) closely related to
Riemann Zeta Function Zeta(s). A formula is obtained for Chi(s) essentially
within the so-called critical strip. This is achieved by applying Cauchy
integral formula to an infinite loop encircling the critical strip. In the
obtained formula a remarkable role is played by a special type of complex
function known as Incomplete Gamma Function. Numerical examples verifying the
obtained formula are included.


title:
A new phase field model for material fatigue in oscillating
  elastoplastic beam

abstract:
  We pursue the study of fatigue accumulation in an oscillating elastoplastic
beam under the additional hypothesis that the material can partially recover by
the effect of melting. The full system consists of the momentum and energy
balance equations, an evolution equation for the fatigue rate, and a
differential inclusion for the phase dynamics. The main result consists in
proving the existence and uniqueness of a strong solution.


title: Biorthogonal ensembles with two-particle interactions

abstract:
  We investigate determinantal point processes on $[0,+\infty)$ of the form
\begin{equation*}\label{probability distribution} \frac{1}{Z_n}\prod_{1\leq
i<j\leq n}(\lambda_j-\lambda_i)\prod_{1\leq i<j\leq
n}(\lambda_j^\theta-\lambda_i^\theta) \prod_{j=1}^n
w(\lambda_j)d\lambda_j,\qquad \theta\geq 1. \end{equation*} We prove that the
biorthogonal polynomials associated to such models satisfy a recurrence
relation and a Christoffel-Darboux formula if $\theta\in\mathbb Q$, and that
they can be characterized in terms of $1\times 2$ vector-valued Riemann-Hilbert
problems which exhibit some non-standard properties. In addition, we obtain
expressions for the equilibrium measure associated to our model if
$w(\lambda)=e^{-nV(\lambda)}$ in the one-cut case with and without hard edge.


title: Differential Scattering and Rethermalization in Ultracold Dipolar Gases

abstract:
  Analytic expressions for the differential cross sections of ultracold atoms
and molecules that scatter primarily due to dipolar interactions are derived
within the first Born approximation, and are shown to agree with the partial
wave expansion. These cross sections are applied to the problem of
cross-dimensional rethermalization. Strikingly, the rate of rethermalization
can vary by as much as a factor of two, depending on the orientation of
polarization of the dipoles. Thus the anisotropic dipole-dipole interaction can
have a profound effect even on the behavior of a nondegenerate ultracold gas.


title:
A Proof Procedure for Hybrid Logic with Binders, Transitivity and
  Relation Hierarchies (extended version)

abstract:
  In previous works, a tableau calculus has been defined, which constitutes a
decision procedure for hybrid logic with the converse and global modalities and
a restricted use of the binder. This work shows how to extend such a calculus
to multi-modal logic enriched with features largely used in description logics:
transitivity and relation inclusion assertions.
  The separate addition of either transitive relations or relation hierarchies
to the considered decidable fragment of multi-modal hybrid logic can easily be
shown to stay decidable, by resorting to results already proved in the
literature. However, such results do not directly allow for concluding whether
the logic including both features is still decidable. The existence of a
terminating, sound and complete calculus for the considered logic proves that
the addition of transitive relations and relation hierarchies to such an
expressive decidable fragment of hybrid logic does not endanger decidability.
  A further result proved in this work is that the logic extending the
considered fragment with the addition of graded modalities (the modal
counterpart of number restrictions of description logics) has an undecidable
satisfiability problem, unless further syntactical restrictions are placed on
the universal graded modality.


title:
Measurement of the $\boldsymbol{W}$ Boson Production Charge Asymmetry in
  $\boldsymbol{p\bar{p}\rightarrow W+X \rightarrow e\nu +X}$ Events at
  $\boldsymbol{\sqrt{s}=1.96}$ TeV

abstract:
  We present a measurement of the $W$ boson production charge asymmetry in
$p\bar{p}\rightarrow W+X \rightarrow e\nu +X$ events at a center of mass energy
of 1.96 TeV, using 9.7 fb$^{-1}$ of integrated luminosity collected with the D0
detector at the Fermilab Tevatron Collider. The neutrino longitudinal momentum
is determined using a neutrino weighting method, and the asymmetry is measured
as a function of the $W$ boson rapidity. The measurement extends over wider
electron pseudorapidity region than previous results, and is the most precise
to date, allowing for precise determination of proton parton distribution
functions in global fits.


title:
On the existence of 1-separated sequences on the unit ball of a finite
  dimensional Banach space

abstract:
  Given a finite dimensional Banach space X with dimX = n and an Auerbach basis
of X, it is proved that: there exists a set D of n + 1 linear combinations
(with coordinates 0, -1, +1) of the members of the basis, so that each pair of
different elements of D have distance greater than one.


title: Quantum Monte Carlo study of the protonated water dimer

abstract:
  We report an extensive theoretical study of the protonated water dimer
(Zundel ion) by means of the highly correlated variational Monte Carlo and
lattice regularized Monte Carlo approaches. This system represents the simplest
model for proton transfer (PT) and a correct description of its properties is
essential in order to understand the PT mechanism in more complex acqueous
systems. Our Jastrow correlated AGP wave function ensures an accurate treatment
of electron correlations. Exploiting the advantages of contracting the
primitive basis set over atomic hybrid orbitals, we are able to limit
dramatically the number of variational parameters with a systematic control on
the numerical precision, crucial in order to simulate larger systems. We
investigate energetics and geometrical properties of the Zundel ion as a
function of the oxygen-oxygen distance, taken as reaction coordinate. In both
cases, our QMC results are found in excellent agreement with coupled cluster
CCSD(T) technique, the quantum chemistry "gold standard". Calculations on
proton transfer static barriers and dissociation energies display the same
agreement. A comparison with density functional theory (DFT) results in the PBE
approximation points out the crucial role of electron correlations for a
correct description of the PT in the dimer. Our method is able to resolve the
tiny energy differences (~ 0.1 Kcal/mol) and the corresponding structural
variations at which the proton transfer takes place; it combines these features
with a N^3-N^4 scaling with number of particles (favorable with respect to
other post-DFT methods), as proven by a benchmark calculation on a larger
protonated water cluster. The QMC approach used here represents a promising
candidate to provide the first high-level ab initio description of PT in water.


title: Periods and global invariants of automorphic representations

abstract:
  We consider periods of automorphic representations of adele groups defined by
integrals along Gelfand subgroups. We define natural maps between local
components of such periods and construct corresponding global maps using
automorphic L-functions. This leads to an introduction of a global invariant of
an automorphic representation arising from two such periods. We compute this
invariant in some cases.


title:
High-energy physics and cosmological perturbations: observing new
  physics at large scales

abstract:
  Correlators of primordial perturbations could provide us with the signatures
of physics at earlier times/higher momentum scales than inflation. The
key-mechanisms are the interference and cumulation in time related to the
interplay of negative- and positive-frequency components of fields and energy
density generated by the high-momentum scale physics. Here, we discuss which
signatures are universal for such scenarios, and which ones instead would
distinguish the specific cases (for example modified initial states for
inflationary perturbations or modified dispersion relations). We also discuss
the scale dependence of the correlators in presence of these signatures,
especially for some scenarios, and how this could be interesting for
observations.


title: Heavy neutrino searches at the LHC with displaced vertices

abstract:
  Sterile neutrinos with masses in the range (1-100) GeV, have been searched
for in a variety of experiments. Here, we discuss the prospects to search for
sterile neutrinos at the LHC using displaced vertices. Two different cases are
discussed: (i) the standard model extended with sterile neutrinos and (ii)
right-handed neutrinos in a left-right symmetric extension of the standard
model. A dedicated displaced vertex search will allow to probe parts of the
parameter space not accessible to other searches, but will require large
luminosity in both cases.


title: Observation of the sling effect

abstract:
  When cloud particles are small enough, they move with the turbulent air in
the cloud. On the other hand, as particles become larger their inertia affects
their motions, and they move differently than the air. These inertial dynamics
impact cloud evolution and ultimately climate prediction, since clouds govern
the earth's energy balances. Yet we lack a simple description of the dynamics.
Falkovich et al. describes theoretically a new dynamical mechanism called the
"sling effect" by which extreme events in the turbulent air cause idealized
inertial cloud particles to break free from the airflow (Falkovich G, Fouxon A,
Stepanov MG 2002 Nature 419, 151). The sling effect thereafter causes particle
trajectories to cross each other within isolated pockets in the flow, which
increases the chance of collisions that form larger particles. We combined
experimental techniques that allow for precise control of a turbulent flow with
three-dimensional tracking of multiple particles at unprecedented resolution.
In this way, we could observe both the sling effect and crossing trajectories
between real particles. We isolated the inertial sling dynamics from those
caused by turbulent advection by conditionally averaging the data. We found the
dynamics to be universal in terms of a local Stokes number that quantifies the
local particle velocity gradients. We measured the probability density of this
quantity, which shows that sharp gradients become more frequent as the global
Stokes number increases. We observed that sharp compressive gradients in the
airflow initiated the sling effect, and that thereafter gradients in the
particle flow ran away and steepened in a way that produced singularities in
the flow in finite time. During this process both the fluid motions and gravity
became unimportant. The results underpin a framework for describing a crucial
aspect of inertial particle dynamics.


title: Transport properties of spacetime-filling branes

abstract:
  A model consisting of (d+1)-dimensional gravity coupled to spacetime filling
charged branes is used to study the effects of backreaction. The charged black
holes arising from this simple model reflect the non-linearity of the gauge
field and are thermodynamically stable. By analysing fluctuations of the system
we corroborate that at low values of the temperature (or large chemical
potential) backreaction effects from the branes are dominant. We also provide a
generalisation of the Iqbal and Liu strategy to calculate the DC conductivity,
in which a mass term for the gauge field fluctuation is included. This mass
term gives the value of the residue of the pole at zero frequency in the
imaginary part of the AC conductivity, as well as the running of the DC
conductivity with the bulk radius.


title:
The lower tail of random quadratic forms, with applications to ordinary
  least squares and restricted eigenvalue properties

abstract:
  Finite sample properties of random covariance-type matrices have been the
subject of much research. In this paper we focus on the "lower tail" of such a
matrix, and prove that it is subgaussian under a simple fourth moment
assumption on the one-dimensional marginals of the random vectors. A similar
result holds for more general sums of random positive semidefinite matrices,
and the (relatively simple) proof uses a variant of the so-called PAC-Bayesian
method for bounding empirical processes.
  We give two applications of the main result. In the first one we obtain a new
finite-sample bound for ordinary least squares estimator in linear regression
with random design. Our result is model-free, requires fairly weak moment
assumptions and is almost optimal. Our second application is to bounding
restricted eigenvalue constants of certain random ensembles with "heavy tails".
These constants are important in the analysis of problems in Compressed Sensing
and High Dimensional Statistics, where one recovers a sparse vector from a
small umber of linear measurements. Our result implies that heavy tails still
allow for the fast recovery rates found in efficient methods such as the LASSO
and the Dantzig selector. Along the way we strengthen, with a fairly short
argument, a recent result of Rudelson and Zhou on the restricted eigenvalue
property.


title:
Kinematic description of crystal plasticity in the finite kinematic
  framework: a micromechanical understanding of F=FeFp

abstract:
  The plastic component of the deformation gradient plays a central role in
finite kinematic models of plasticity. However, its characterization has been
the source of extended debates in the literature and many important issues
still remain unresolved. Some examples are the micromechanical understanding of
F=FeFp with multiple active slip systems, the uniqueness of the decomposition,
or the characterization of the plastic deformation without reference to the
so-called intermediate configuration. In this paper, we shed some light to
these issues via a two-dimensional kinematic analysis of the plastic
deformation induced by discrete slip surfaces and the corresponding dislocation
structures. In particular, we supply definitions for the elastic and plastic
components of the deformation gradient as a function of the active slip systems
without any a priori assumption on the decomposition of the total deformation
gradient. These definitions are explicitly and uniquely given from the
microstructure and do not make use of any unrealizable intermediate
configuration. These quantities are then passed to the continuous limit via
homogenization, i.e., by increasing the number of slip surfaces to infinity and
reducing the lattice parameter to zero. This continuum limit is computed for
several illustrative examples, where the well-known multiplicative
decomposition of the total deformation gradient is recovered. Additionally, by
similar arguments, an expression of the dislocation density tensor is obtained
as the limit of discrete dislocation densities.


title:
Unfitted finite element methods using bulk meshes for surface partial
  differential equations

abstract:
  In this paper, we define new unfitted finite element methods for numerically
approximating the solution of surface partial differential equations using bulk
finite elements. The key idea is that the $n$-dimensional hypersurface, $\Gamma
\subset \mathbb{R}^{n+1}$, is embedded in a polyhedral domain in $\mathbb
R^{n+1}$ consisting of a union, $\mathcal{T}_h$, of $(n+1)$-simplices. The
finite element approximating space is based on continuous piece-wise linear
finite element functions on $\mathcal{T}_h$. Our first method is a sharp
interface method, \emph{SIF}, which uses the bulk finite element space in an
approximating weak formulation obtained from integration on a polygonal
approximation, $\Gamma_{h}$, of $\Gamma$. The full gradient is used rather than
the projected tangential gradient and it is this which distinguishes \emph{SIF}
from the method of [42]. The second method, \emph{NBM}, is a narrow band method
in which the region of integration is a narrow band of width $O(h)$. \emph{NBM}
is similar to the method of [13]. but again the full gradient is used in the
discrete weak formulation. The a priori error analysis in this paper shows that
the methods are of optimal order in the surface $L^{2}$ and $H^{1}$ norms and
have the advantage that the normal derivative of the discrete solution is small
and converges to zero. Our third method combines bulk finite elements, discrete
sharp interfaces and narrow bands in order to give an unfitted finite element
method for parabolic equations on evolving surfaces. We show that our method is
conservative so that it preserves mass in the case of an advection diffusion
conservation law. Numerical results are given which illustrate the rates of
convergence.


title: Gravitational collapse in spatially isotropic coordinates

abstract:
  We investigate the dynamical nature of the collapse process of a spherically
symmetric star in quasi-static hydrodynamical equilibrium. The star collapses
from an initial static configuration by dissipating energy in the form of a
radial heat flux. The dissipation ensures that the singularity is never formed
and the stellar mass completely evaporates over a finite time.


title:
Deformed Twistors and Higher Spin Conformal (Super-)Algebras in Four
  Dimensions

abstract:
  Massless conformal scalar field in d=4 corresponds to the minimal unitary
representation (minrep) of the conformal group SU(2,2) which admits a
one-parameter family of deformations that describe massless fields of arbitrary
helicity. The minrep and its deformations were obtained by quantization of the
nonlinear realization of SU(2,2) as a quasiconformal group in arXiv:0908.3624.
We show that the generators of SU(2,2) for these unitary irreducible
representations can be written as bilinears of deformed twistorial oscillators
which transform nonlinearly under the Lorentz group and apply them to define
and study higher spin algebras and superalgebras in AdS_5. The higher spin (HS)
algebra of Fradkin-Vasiliev type in AdS_5 is simply the enveloping algebra of
SU(2,2) quotiented by a two-sided ideal (Joseph ideal) which annihilates the
minrep. We show that the Joseph ideal vanishes identically for the
quasiconformal realization of the minrep and its enveloping algebra leads
directly to the HS algebra in AdS_5. Furthermore, the enveloping algebras of
the deformations of the minrep define a one parameter family of HS algebras in
AdS_5 for which certain 4d covariant deformations of the Joseph ideal vanish
identically. These results extend to superconformal algebras SU(2,2|N) and we
find a one parameter family of HS superalgebras as enveloping algebras of the
minimal unitary supermultiplet and its deformations. Our results suggest the
existence of a family of (supersymmetric) HS theories in AdS_5 which are dual
to free (super)conformal field theories (CFTs) or to interacting but integrable
(supersymmetric) CFTs in 4d. We also discuss the corresponding picture in AdS_4
where the 3d conformal group Sp(4,R) admits only two massless representations
(minreps), namely the scalar and spinor singletons.


title: Designing III-V Multijunction Solar Cells on Silicon

abstract:
  Single junction Si solar cells dominate photovoltaics but are close to their
efficiency limits. This paper presents ideal limiting efficiencies for tandem
and triple junction multijunction solar cells subject only to the constraint of
the Si bandgap and therefore recommending optimum cell structures departing
from the single junction ideal. The use of III-V materials is considered, using
a novel growth method capable of yielding low defect density III-V layers on
Si. In order to evaluate the real potential of these proposed multijunction
designs, a quantitative model is presented, the strength of which is the joint
modelling of external quantum efficiency and current-voltage characteristics
using the same parameters. The method yields a single parameter fit in terms of
the Shockley-Read-Hall lifetime. This model is validated by fitting
experimental data of external quantum efficiency, dark current, and conversion
efficiency of world record tandem and triple junction cells under terrestrial
solar spectra without concentration. We apply this quantitative model to the
design of tandem and triple junction solar cells, yielding cell designs capable
of reaching efficiencies without concentration of 32% for the best tandem cell
and 36% for the best triple junction cell. This demonstrates that efficiencies
within a few percent of world records are realistically achievable without the
use of concentrating optics, with growth methods being developed for
multijunction cells combining III-V and Si materials.


title: Camera Gap Removal in SOLIS/VSM Images

abstract:
  The Vector Spectromagnetograph (VSM) instrument on the Synoptic Optical
Longterm Investigations of the Sun (SOLIS) telescope is capable of obtaining
spectropolarimetry for the full Sun (or a select latitudinal range) with one
arcsecond spatial resolution and 0.05 Angstrom spectral resolution. This is
achieved by scanning the Sun in declination and building up spectral cubes for
multiple polarization states, utilizing a beamsplitter and two separate 2k x 2k
CCD cameras. As a result, the eastern and western hemispheres of the Sun are
separated in preliminary VSM images by a vertical gap with soft edges and
variable position and width. Prior to the comprehensive analysis presented in
this document, a trial-and-error approach to removing the gap had yielded an
algorithm that was inconsistent, undocumented, and responsible for incorrectly
eliminating too many image columns. Here we describe, in detail, the basis for
a new, streamlined, and properly calibrated prescription for locating and
removing the gap that is correct to within approximately one arcsecond (one
column).


title:
On the alignment of PNe and local magnetic field at the galactic centre:
  MHD numerical simulations

abstract:
  For the past decade observations of the alignement of PNe symmetries with
respect to the galactic disk have led to conflicting results. Recently
observational evidence for alignment between PNe and local interstellar
magnetic fields in the central part of the Galaxy ($b < 5^\circ$) has been
found. We studied the role of the interstellar magnetic field on the dynamical
evolution of a PN by means of an analytical model and from 3D MHD numerical
simulations. We test under what conditions typical ejecta would have their
dynamics severely modified by an interstellar magnetic field. We found that
uniform fields of $> 100\mu$G are required in order to be dynamically dominant.
This is found to occur only at later evolutionary stages, therefore being
unable to change the general morphology of the nebula. However, the symmetry
axis of bipolar and elliptical nebulae end up aligned to the external field.
This result can explain why different samples of PNe result in different
conclusions regarding the alignment of PNe. Objects located at high galactic
latitudes, or at large radii, should present no preferential alignment with
respect to the galactic plane. PNe located at the galactic centre and low
latitudes would, on the other hand, be preferentiably aligned to the disk.
Finally, we present synthetic polarization maps of the nebulae to show that the
polarization vectors, as well as the field lines at the expanding shell, are
not uniform even in the strongly magnetized case, indicating that polarization
maps of nebulae are not adequate in probing the orientation, or intensity, of
the dominant external field.


title:
Type Ib SN 1999dn as an example of the thoroughly mixed ejecta of Ib
  supernovae

abstract:
  We present the results of modelling archival observations of type Ib SN
1999dn. In the spectra, two He I absorption features are seen: a slower
component with larger opacity, and a more rapid He I component with smaller
opacity. Complementary results are obtained from modelling the bolometric light
curve of SN 1999dn, where a two-zone model (dense inner region, and less dense
outer region) provides a much better fit than a one-zone model. A key result we
find is that roughly equal amounts of radioactive material are found in both
regions. The two-zone analytical model provides a more realistic representation
of the structure of the ejecta, including mixing and asymmetries, which offers
a physical explanation for how the radioactive material is propelled to, and
mixed within, the outer regions. Our result supports the theoretical
expectation that the radioactive content in the outflow of a type Ib supernova
(SN) is thoroughly mixed. We fit our model to six additional SNe Ibc, of which
the majority of the SNe Ib are best described by the two-zone model, and the
majority of the SNe Ic by the one-zone model. Of the SNe Ic, only SN 2007gr was
best fit by the two-zone model, indicating that the lack of helium spectral
features for this event cannot be attributed to poor mixing.


title: Notes on the flexible manipulator

abstract:
  The existence of solutions to the boundary tracking of the displacement at
one end of a linear Timoshenko beam is discussed on the basis of the Cauchy
problem with time and space interchanged.


title: Gamma-ray Pulsar Revolution

abstract:
  Isolated Neutron Stars (INSs) were the first sources identified in the field
of high-energy gamma-ray astronomy. At first, in the 70s, there were only two
identified sources, the Crab and Vela pulsars. However, although few in number,
these objects were crucial in establishing the very concept of a gamma-ray
source. Moreover, they opened up significant discovery space both in the
theoretical and phenomenological fronts. The need to explain the copious
gamma-ray emission of these pulsars led to breakthrough developments in
understanding the structure and physics of neutron star magnetospheres. In
parallel, the 20-year-long chase to understand the nature of Geminga unveiled
the existence of a radio-quiet, gamma-ray-emitting, INS, adding a new dimension
to the INS family. Today we are living through an extraordinary time of
discovery. The current generation of gamma-ray detectors has vastly increased
the population of known of gamma-ray-emitting neutron stars. The 100 mark was
crossed in 2011 and we are now approaching 150. The gamma-ray-emitting neutron
star population exhibits roughly equal numbers of radio-loud and radio-quiet
young INSs, plus an astonishing, and unexpected, group of isolated and binary
millisecond pulsars (MSPs). The number of MSPs is growing so rapidly that they
are on their way to becoming the most numerous members of the family of
gamma-ray-emitting Neutron Stars (NSs) . Even as these findings have set the
stage for a revolution in our understanding of gamma-ray-emitting neutron
stars, long term monitoring of the gamma-ray sky has revealed evidence of flux
variability in the Crab Nebula as well as in the pulsed emission from PSR
J2021+4026, challenging a four-decade-old, constant-emission paradigm. Now we
know that both pulsars and their nebulae can, indeed, display variable
emission.


title:
Semileptonic $B \to D^{**}$ decays in Lattice QCD : a feasibility study
  and first results

abstract:
  We compute the decays ${B\to D^\ast_0}$ and ${B\to D^\ast_2}$ with finite
masses for the $b$ and $c$ quarks. We first discuss the spectral properties of
both the $B$ meson as a function of its momentum and of the $D^\ast_0$ and
$D^\ast_2$ at rest. We compute the theoretical formulae leading to the decay
amplitudes from the three-point and two-point correlators. We then compute the
amplitudes at zero recoil of ${B\to D^\ast_0}$ which turns out not to be
vanishing contrary to what happens in the heavy quark limit. This opens a
possibility to get a better agreement with experiment. To improve the continuum
limit we have added a set of data with smaller lattice spacing. The ${B\to
D^\ast_2}$ vanishes at zero recoil and we show a convincing signal but only
slightly more than 1 sigma from 0. In order to reach quantitatively significant
results, we plan to fully exploit smaller lattice spacings as well as another
lattice regularization.


title:
Hardness of Finding Independent Sets in 2-Colorable Hypergraphs and of
  Satisfiable CSPs

abstract:
  This work revisits the PCP Verifiers used in the works of Hastad [Has01],
Guruswami et al.[GHS02], Holmerin[Hol02] and Guruswami[Gur00] for satisfiable
Max-E3-SAT and Max-Ek-Set-Splitting, and independent set in 2-colorable
4-uniform hypergraphs. We provide simpler and more efficient PCP Verifiers to
prove the following improved hardness results: Assuming that NP\not\subseteq
DTIME(N^{O(loglog N)}),
  There is no polynomial time algorithm that, given an n-vertex 2-colorable
4-uniform hypergraph, finds an independent set of n/(log n)^c vertices, for
some constant c > 0.
  There is no polynomial time algorithm that satisfies 7/8 + 1/(log n)^c
fraction of the clauses of a satisfiable Max-E3-SAT instance of size n, for
some constant c > 0.
  For any fixed k >= 4, there is no polynomial time algorithm that finds a
partition splitting (1 - 2^{-k+1}) + 1/(log n)^c fraction of the k-sets of a
satisfiable Max-Ek-Set-Splitting instance of size n, for some constant c > 0.
  Our hardness factor for independent set in 2-colorable 4-uniform hypergraphs
is an exponential improvement over the previous results of Guruswami et
al.[GHS02] and Holmerin[Hol02]. Similarly, our inapproximability of (log
n)^{-c} beyond the random assignment threshold for Max-E3-SAT and
Max-Ek-Set-Splitting is an exponential improvement over the previous bounds
proved in [Has01], [Hol02] and [Gur00]. The PCP Verifiers used in our results
avoid the use of a variable bias parameter used in previous works, which leads
to the improved hardness thresholds in addition to simplifying the analysis
substantially. Apart from standard techniques from Fourier Analysis, for the
first mentioned result we use a mixing estimate of Markov Chains based on
uniform reverse hypercontractivity over general product spaces from the work of
Mossel et al.[MOS13].


title:
The solid angle and the Burgers formula in the theory of gradient
  elasticity: line integral representation

abstract:
  A representation of the solid angle and the Burgers formula as line integral
is derived in the framework of the theory of gradient elasticity of Helmholtz
type. The gradient version of the Eshelby-deWit representation of the Burgers
formula of a closed dislocation loop is given. Such a form is suitable for the
numerical implementation in 3D dislocation dynamics (DD).


title:
On the absence of "splash" singularities in the case of two-fluid
  interfaces

abstract:
  We show that "splash" singularities cannot develop in the case of locally
smooth solutions of the two-fluid interface in two dimensions. More precisely,
we show that the scenario of formation of singularities discovered by
Castro-C\'{o}rdoba-Fefferman-Gancedo-G\'{o}mez-Serrano in the case of the water
waves system, in which the interface remains locally smooth but self-intersects
in finite time, is completely prevented in the case of two-fluid interfaces
with positive densities.


title: Intervalley biexcitons and many-body effects in monolayer MoS2

abstract:
  Interactions between two excitons can result in the formation of bound
quasiparticles, known as biexcitons. Their properties are determined by the
constituent excitons, with orbital and spin states resembling those of atoms.
Monolayer transition metal dichalcogenides (TMDs) present a unique system where
excitons acquire a new degree of freedom, the valley pseudospin, from which a
novel intervalley biexciton can be created. These biexcitons comprise two
excitons from different valleys, which are distinct from biexcitons in
conventional semiconductors and have no direct analogue in atomic and molecular
systems. However, their valley properties are not accessible to traditional
transport and optical measurements. Here, we report the observation of
intervalley biexcitons in the monolayer TMD MoS2 using ultrafast pump-probe
spectroscopy. By applying broadband probe pulses with different helicities, we
identify two species of intervalley biexcitons with large binding energies of
60 meV and 40 meV. In addition, we also reveal effects beyond biexcitonic
pairwise interactions in which the exciton energy redshifts at increasing
exciton densities, indicating the presence of many-body interactions among
them.


title: Win-Move is Coordination-Free (Sometimes)

abstract:
  In a recent paper by Hellerstein [15], a tight relationship was conjectured
between the number of strata of a Datalog${}^\neg$ program and the number of
"coordination stages" required for its distributed computation. Indeed, Ameloot
et al. [9] showed that a query can be computed by a coordination-free
relational transducer network iff it is monotone, thus answering in the
affirmative a variant of Hellerstein's CALM conjecture, based on a particular
definition of coordination-free computation. In this paper, we present three
additional models for declarative networking. In these variants, relational
transducers have limited access to the way data is distributed. This variation
allows transducer networks to compute more queries in a coordination-free
manner: e.g., a transducer can check whether a ground atom $A$ over the input
schema is in the "scope" of the local node, and then send either $A$ or $\neg
A$ to other nodes.
  We show the surprising result that the query given by the well-founded
semantics of the unstratifiable win-move program is coordination-free in some
of the models we consider. We also show that the original transducer network
model [9] and our variants form a strict hierarchy of classes of
coordination-free queries. Finally, we identify different syntactic fragments
of Datalog${}^{\neg\neg}_{\forall}$, called semi-monotone programs, which can
be used as declarative network programming languages, whose distributed
computation is guaranteed to be eventually consistent and coordination-free.


title: Some remarks on Hilbert representations of posets

abstract:
  For a certain class of finite posets, we prove that all their irreducible
orthoscalar representations are finite-dimensional and describe those, for
which there exist essential (non-degenerate) irreducible orthoscalar
representations.


title: Welschinger invariants of real del Pezzo surfaces of degree $\ge2$

abstract:
  We compute the purely real Welschinger invariants, both original and
modified, for all real del Pezzo surfaces of degree at least 2. We show that
under some conditions, for such a surface $X$ and a real nef and big divisor
class $D$, through any generic collection of $-DK_X-1$ real points lying on a
connected component of the real part of $X$ one can trace a real rational curve
$C\in|D|$. This is derived from the positivity of appropriate Welschinger
invariants. We furthermore show that these invariants are asymptotically
equivalent, in the logarithmic scale, to the corresponding genus zero
Gromov-Witten invariants. Our approach consists in a conversion of
Shoval-Shustin recursive formulas counting complex curves on the plane blown up
at seven points and of Vakil's extension of the Abramovich-Bertram formula for
Gromov-Witten nvariants into formulas computing real enumerative invariants.


title: A proof of the birationality of certain BHK-mirrors

abstract:
  We generalize and give an elementary proof of Kelly's refinement of
Shoemaker's result on the birationality of certain BHK-mirrors. Our approach
uses a construction that is equivalent to the Krawitz generalization of the
duality of Berglund-Hubsch.


title: Lagrangian Time Series Models for Ocean Surface Drifter Trajectories

abstract:
  This paper proposes stochastic models for the analysis of ocean surface
trajectories obtained from freely-drifting satellite-tracked instruments. The
proposed time series models are used to summarise large multivariate datasets
and infer important physical parameters of inertial oscillations and other
ocean processes. Nonstationary time series methods are employed to account for
the spatiotemporal variability of each trajectory. Because the datasets are
large, we construct computationally efficient methods through the use of
frequency-domain modelling and estimation, with the data expressed as
complex-valued time series. We detail how practical issues related to sampling
and model misspecification may be addressed using semi-parametric techniques
for time series, and we demonstrate the effectiveness of our stochastic models
through application to both real-world data and to numerical model output.

categories: stat.AP physics.ao-ph physics.flu-dyn stat.ME


title: On Cohen braids

abstract:
  For a general surface $M$ and an arbitrary braid $\alpha$ from the surface
braid group $B_{n-1}(M)$ we study the system of equations
$d_1\beta=\cdots=d_{n}\beta=\alpha, $ where operation $d_i$ is deleting of
$i$-th strand. We obtain that if $M\not=S^2$ or $\mathbb RP^2$ this system of
equations has a solution $\beta\in B_{n}(M)$ if and only if
$d_1\alpha=\ldots=d_n\alpha. $ The set of braids satisfying the last system of
equations we call Cohen braids. We also construct a set of generators for the
groups of Cohen braids. In the cases of the sphere and the projective plane we
give some examples for the small number of strands.


title: Dilaton Effective Action with $\mathcal{N}=1$ Supersymmetry

abstract:
  We clarify the structure of the four-dimensional low-energy effective action
that encodes the conformal and $U(1)$ R-symmetry anomalies in an
$\mathcal{N}=1$ supersymmetric field theory. The action depends on the dilaton,
$\tau$, associated with broken conformal symmetry, and the Goldstone mode,
$\beta$, of the broken $U(1)$ R-symmetry. We present the action for general
curved spacetime and background gauge field up to and including all possible
four-derivative terms. The result, constructed from basic principles, extends
and clarifies the structure found by Schwimmer and Theisen in arXiv:1011.0696
using superfield methods. We show that the Goldstone mode $\beta$ does not
interfere with the proof of the four-dimensional $a$-theorem based on $2 \to 2$
dilaton scattering. In fact, supersymmetry Ward identities ensure that a proof
of the $a$-theorem can also be based on $2 \to 2$ Goldstone mode scattering
when the low-energy theory preserves $\mathcal{N}=1$ supersymmetry. We find
that even without supersymmetry, a Goldstone mode for any broken global $U(1)$
symmetry cannot interfere with the proof of the four-dimensional $a$-theorem.


title: Close encounters among the primes

abstract:
  This paper was written, apart from one technical correction, in July and
August of 2013. The, then very recent, breakthrough of Y. Zhang \cite{Z} had
revived in us an intention to produce a second edition of our book "Opera de
Cribro", one which would include an account of Zhang's result, stressing the
sieve aspects of the method. A complete and connected version of the proof, in
our style but not intended for journal publication, seemed a natural first step
in this project. Following the further spectacular advance given by J. Maynard
(arXiv:1311.4600, Nov 20, 2013), we have had to re-think our position.
Maynard's method, at least in its current form, proceeds from GPY in quite a
different direction than does Zhang's, and achieves numerically superior
results. Consequently, although Zhang's contribution to the distribution of
primes in arithmetic progressions certainly retains its importance, the fact
remains that much of the material in this paper would no longer appear in a new
edition of our book. Because this paper contains some innovations that we do
not wish to become lost, we have decided to make the work publicly available in
its current form.


title: The Smallest Particles in Saturn's A and C Rings

abstract:
  Radio occultations of Saturn's main rings by spacecraft suggest a power law
particle size-distribution down to sizes of the order of 1 cm (Marouf et al.,
1983), (Zebker et al., 1985). The lack of optical depth variations between
ultraviolet and near-IR wavelengths indicate a lack of micron-sized particles.
Between these two regimes, the particle-size distribution is largely unknown. A
cutoff where the particle-size distribution turns over must exist, but the
position and shape of it is not clear from existing studies.
  Using a series of solar occultations performed by the VIMS instrument
on-board Cassini in the near-infrared, we are able to measure light forward
scattered by particles in the A and C rings. With a model of diffraction by
ring particles, and the previous radio work as a constraint on the slope of the
particle size distribution, we estimate the minimum particle size using a
truncated power-law size distribution. The C Ring shows a minimum particle size
of $4.1^{+3.8}_{-1.3}$ mm, with an assumed power law index of q=3.1 and a
maximum particle size of 10 m.
  The A Ring signal shows a similar level of scattered flux, but modeling is
complicated by the presence of self-gravity wakes and higher optical depths. If
q<3, our A Ring model requires a minimum particle size below one millimeter (<
0.34 mm for an assumed q=2.75, or $0.56^{+0.35}_{-0.16}$ mm for a steeper
q=2.9) to be consistent with VIMS observations. These results might seem to
contradict previous optical(Dones et al., 1993) and infrared (French and
Nicholson, 2000) work, which implied that there were few particles in the A
Ring smaller than 1 cm. But, because of the shallow power law, relatively
little optical depth (between 0.03 and 0.16 in extinction, or 0.015 - 0.08 in
absorption) is provided by these particles.


title: Scaling and tuning of EW and Higgs observables

abstract:
  We study deformations of the SM via higher dimensional operators. In
particular, we explicitly calculate the one-loop anomalous dimension matrix for
13 bosonic dimension-6 operators relevant for electroweak and Higgs physics.
These scaling equations allow us to derive RG-induced bounds, stronger than the
direct constraints, on a universal shift of the Higgs couplings and some
anomalous triple gauge couplings by assuming no tuning at the scale of new
physics, i.e. by requiring that their individual contributions to the running
of other severely constrained observables, like the electroweak oblique
parameters or $\Gamma(h \rightarrow \gamma\gamma)$, do not exceed their
experimental direct bounds. We also study operators involving the Higgs and
gluon fields.


title: On discontinuity of planar optimal transport maps

abstract:
  Consider two bounded domains $\Omega$ and $\Lambda$ in $\mathbb{R}^{2}$, and
two sufficiently regular probability measures $\mu$ and $\nu$ supported on
them. By Brenier's theorem, there exists a unique transportation map $T$
satisfying $T_\#\mu=\nu$ and minimizing the quadratic cost
$\int_{\mathbb{R}^{n}}|T(x)-x|^{2}d\mu(x)$. Furthermore, by Caffarelli's
regularity theory for the real Monge--Amp\`ere equations, if $\Lambda$ is
convex, $T$ is continuous.
  We study the reverse problem, namely, when is $T$ discontinuous if $\Lambda$
fails to be convex? We prove a result guaranteeing the discontinuity of $T$ in
terms of the geometries of $\Lambda$ and $\Omega$ in the two-dimensional case.
The main idea is to use tools of convex analysis and the extrinsic geometry of
$\partial\Lambda$ to distinguish between Brenier and Alexandrov weak solutions
of the Monge--Amp\`ere equation. We also use this approach to give a new proof
of a result due to Wolfson and Urbas.
  We conclude by revisiting an example of Caffarelli, giving a detailed study
of a discontinuous map between two explicit domains, and determining precisely
where the discontinuities occur.


title: Theoretical Perspective of Charm Physics

abstract:
  A perspective on charm physics, emphasizing recent developments, future
prospects, and the interplay with lattice QCD.


title: Asymptotic Behaviour of Nonlinear Evolution Equations in Banach Spaces

abstract:
  We show how the approach of Yosida approximation of the derivative serves to
obtain new results for evolution systems. Using this method we obtain
multivalued time dependent perturbation results. Additionally, translation
invariant subspaces $Y$ of the bounded and uniformly continuous functions are
considered, to obtain criteria for the existence of solutions $u\in Y$ to the
equation $$ u^{\prime}(t)\in
  A(t)u(t)+ \om u(t) + f(t), t\in \re, $$ or of solutions $u$ asymptotically
close to $Y$ for the inhomogeneous differential equation \begin{eqnarray*}
u^{\prime}(t)&\in& A(t)u(t) + \om u(t) + f(t), \ \ t > 0, u(0)&=&u_0,
\end{eqnarray*} in general Banach spaces, where $A(t)$ denotes a possibly
nonlinear time dependent dissipative operator. Particular examples for the
space $Y$ are spaces of functions with various almost periodicity properties
and more general types of asymptotic behavior. Further, an application to
functional differential equations is given.


title:
Transient Quantum Coherent Response to a Partially Coherent Radiation
  Field

abstract:
  The response of an arbitrary closed quantum system to a partially coherent
electric field is investigated, with a focus on the transient coherences in the
system. As a model we examine, both perturbatively and numerically, the
coherences induced in a three level $V$ system. Both rapid turn-on and pulsed
turn-on effects are investigated. The effect of a long and incoherent pulse is
also considered, demonstrating that during the pulse the system shows a
coherent response which reduces after the pulse is over. Both the pulsed
scenario and the thermally broadened CW case approach a mixed state in the long
time limit, with rates dictated by the adjacent level spacings and the
coherence time of the light, and via a mechanism that is distinctly difference
from traditional decoherence. These two excitation scenarios are also explored
for a minimal "toy" model of the electronic levels in pigment protein complex
PC645 by both a collisionally broadened CW laser and by a noisy pulse, where
unexpectedly long transient coherence times are observed and explained. The
significance of environmentally induced decoherence is noted.


title: Ricci flow neckpinches without rotational symmetry

abstract:
  We study "warped Berger" solutions $\big(\mc S^1\times\mc S^3,G(t)\big)$ of
Ricci flow: generalized warped products with the metric induced on each fiber
$\{s\}\times\mathrm{SU}(2)$ a left-invariant Berger metric. We prove that this
structure is preserved by the flow, that these solutions develop finite-time
neckpinch singularities, and that they asymptotically approach round product
metrics in space-time neighborhoods of their singular sets, in precise senses.
These are the first examples of Ricci flow solutions without rotational
symmetry that become asymptotically rotationally symmetric locally as they
develop local finite-time singularities.


title: Rashba spin orbit coupling in the Kane-Mele-Hubbard model

abstract:
  Spin-orbit (SO) coupling is the crucial parameter to drive topological
insulating phases in electronic band models. In particular, the generic
emergence of SO coupling involves the Rashba term which fully breaks the SU(2)
spin symmetry. As soon as interactions are taken into account, however, many
theoretical studies have to content themselves with the analysis of a
simplified U(1) conserving SO term without Rashba coupling. We intend to fill
this gap by studying the Kane-Mele-Hubbard (KMH) model in the presence of
Rashba SO coupling and present the first systematic analysis of the effect of
Rashba SO coupling in a correlated two-dimensional topological insulator. We
apply the variational cluster approach (VCA) to determine the interacting phase
diagram by computing local density of states, magnetization, single particle
spectral function, and edge states. Preceded by a detailed VCA analysis of the
KMH model in the presence of U(1) conserving SO coupling, we find that the
additional Rashba SO coupling drives new electronic phases such as a metallic
regime and a direct-gap only topological insulating phase which persist in the
presence of interactions.


title: Some results from algebraic geometry over Henselian real valued fields

abstract:
  This paper develops algebraic geometry over Henselian real valued (i.e. of
rank 1) fields $K$, being a sequel to our paper about that over Henselian
discretely valued fields. Several results are given including: a certain
concept of fiber shrinking (a relaxed version of curve selection) for definable
sets, the canonical projection $K^{n} \times K\mathbb{P}^{m} \to K^{n}$ and
blow-ups of the $K$-points of smooth $K$-varieties are definably closed maps, a
descent property for blow-ups, a version of the Lojasiewicz inequality for
continuous rational functions and the theorem on extending continuous
hereditarily rational functions, established for the real and $p$-adic
varieties in our joint paper with J. Kollar. The descent property enables
application of desingularization and transformation to a normal crossing by
blowing up in much the same way as over the locally compact ground field. Our
approach applies quantifier elimination due to Pas.


title: Active Player Modelling

abstract:
  We argue for the use of active learning methods for player modelling. In
active learning, the learning algorithm chooses where to sample the search
space so as to optimise learning progress. We hypothesise that player modelling
based on active learning could result in vastly more efficient learning, but
will require big changes in how data is collected. Some example active player
modelling scenarios are described. A particular form of active learning is also
equivalent to an influential formalisation of (human and machine) curiosity,
and games with active learning could therefore be seen as being curious about
the player. We further hypothesise that this form of curiosity is symmetric,
and therefore that games that explore their players based on the principles of
active learning will turn out to select game configurations that are
interesting to the player that is being explored.


title: A multi-stable switchable metamaterial

abstract:
  The field of metamaterial research revolves around the idea of creating
artificial media that interact with light in a way unknown from naturally
occurring materials. This is commonly achieved by creating sub-wavelength
lattices of electronic or plasmonic structures, so-called meta-atoms, that
determine the interaction between light and metamaterial. One of the ultimate
goals for these tailored media is the ability to control their properties
in-situ which has led to a whole new branch of tunable and switchable
metamaterials. Many of the present realizations rely on introducing
microelectromechanical actuators or semiconductor elements into their meta-atom
structures. Here we show that superconducting quantum interference devices
(SQUIDs) can be used as fast, intrinsically switchable meta-atoms. We found
that their intrinsic nonlinearity leads to simultaneously stable dynamic
states, each of which is associated with a different value and sign of the
magnetic susceptibility in the microwave domain. Moreover, we demonstrate that
it is possible to switch between these states by applying a nanosecond long
pulse in addition to the microwave probe signal. Apart from potential
applications such as, for example, an all-optical metamaterial switch, these
results suggest that multi-stability, which is a common feature in many
nonlinear systems, can be utilized to create new types of meta-atoms.


title:
Real-time and real-space spin- and energy dynamics in one-dimensional
  spin-1/2 systems induced by local quantum quenches at finite temperatures

abstract:
  We study the spin- and energy dynamics in one-dimensional spin-1/2 systems
induced by local quantum quenches at finite temperatures using a time-dependent
density matrix renormalization group method. System sizes are chosen large
enough to ensure that the time-dependent data for the accesible time scales
represents the behavior in the thermodynamic limit. As a main result, we
observe a ballistic spreading of perturbations of the energy density in the
integrable spin-1/2 XXZ chain for all temperatures and exchange anisotropies,
related to the divergent thermal conductivity in this model and the exact
conservation of the energy current. In contrast, the spin dynamics is ballistic
in the massless phase, but shows a diffusive behavior at high temperatures in
the easy-axis phase in the case of a vanishing background spin density. We
extract a quantitative estimate for the spin diffusion constant from the time
dependence of the spatial variance of the spin density, which agrees well with
values obtained from current-current correlation functions using an Einstein
relation. As an example for non-integrable models, we consider two-leg ladders,
for which we observe indications of diffusive energy and spin dynamics. The
relevance of our results for recent experiments with quantum magnets and bosons
in optical lattices is discussed.


title:
Quasinormal mode approach to modelling light-emission and propagation in
  nanoplasmonics

abstract:
  We describe a powerful and intuitive technique for modeling light-matter
interactions in classical and quantum nanoplasmonics. Our approach uses a
quasinormal mode expansion of the Green function within a metal nanoresonator
of arbitrary shape, together with a Dyson equation, to derive an expression for
the spontaneous decay rate and far field propagator from dipole oscillators
outside resonators. For a single quasinormal mode, at field positions outside
the quasi-static coupling regime, we give a closed form solution for the
Purcell factor and generalized effective mode volume. We augment this with an
analytic expression for the divergent LDOS very near the metal surface, which
allows us to derive a simple and highly accurate expression for the electric
field outside the metal resonator at distances from a few nanometers to
infinity. This intuitive formalism provides an enormous simplification over
full numerical calculations and fixes several pending problems in quasinormal
mode theory.


title: Homogeneous spherical data of orbits in spherical embeddings

abstract:
  Let $G$ be a connected reductive complex algebraic group. Luna assigned to
any spherical homogeneous space $G/H$ a combinatorial object called a
homogeneous spherical datum. By a theorem of Losev, this object uniquely
determines $G/H$ up to $G$-equivariant isomorphism. In this paper, we determine
the homogeneous spherical datum of a $G$-orbit $X_0$ in a spherical embedding
$G/H \hookrightarrow X$. As an application, we obtain a description of the
colored fan associated to the spherical embedding $X_0 \hookrightarrow
\bar{X_0}$.


title: A Grassmann Path From AdS_3 to Flat Space

abstract:
  We show that interpreting the inverse AdS_3 radius 1/l as a Grassmann
variable results in a formal map from gravity in AdS_3 to gravity in flat
space. The underlying reason for this is the fact that ISO(2,1) is the
Inonu-Wigner contraction of SO(2,2). We show how this works for the
Chern-Simons actions, demonstrate how the general (Banados) solution in AdS_3
maps to the general flat space solution, and how the Killing vectors, charges
and the Virasoro algebra in the Brown-Henneaux case map to the corresponding
quantities in the BMS_3 case. Our results straightforwardly generalize to the
higher spin case: the recently constructed flat space higher spin theories
emerge automatically in this approach from their AdS counterparts. We conclude
with a discussion of singularity resolution in the BMS gauge as an application.


title: Evolutionary Game Dynamics in Populations with Heterogeneous Structures

abstract:
  Evolutionary graph theory is a well established framework for modelling the
evolution of social behaviours in structured populations. An emerging consensus
in this field is that graphs that exhibit heterogeneity in the number of
connections between individuals are more conducive to the spread of cooperative
behaviours. In this article we show that such a conclusion largely depends on
the individual-level interactions that take place. In particular, averaging
payoffs garnered through game interactions rather than accumulating the payoffs
can altogether remove the cooperative advantage of heterogeneous graphs while
such a difference does not affect the outcome on homogeneous structures. In
addition, the rate at which game interactions occur can alter the evolutionary
outcome. Less interactions allow heterogeneous graphs to support more
cooperation than homogeneous graphs, while higher rates of interactions make
homogeneous and heterogeneous graphs virtually indistinguishable in their
ability to support cooperation. Most importantly, we show that common measures
of evolutionary advantage used in homogeneous populations, such as a comparison
of the fixation probability of a rare mutant to that of the resident type, are
no longer valid in heterogeneous populations. Heterogeneity causes a bias in
where mutations occur in the population which affects the mutant's fixation
probability. We derive the appropriate measures for heterogeneous populations
that account for this bias.


title: Gaia FGK Benchmark Stars and their reference parameters

abstract:
  In this article we summarise on-going work on the so-called Gaia FGK
Benchmark Stars. This work consists of the determination of their atmospheric
parameters and of the construction of a high-resolution spectral library. The
definition of such a set of reference stars has become crucial in the current
era of large spectroscopic surveys. Only with homogeneous and well documented
stellar parameters can one exploit these surveys consistently and understand
the structure and history of the Milky Way and therefore other of galaxies in
the Universe.


title: The K-homology of nets of C*-algebras

abstract:
  Let X be a space, intended as a possibly curved spacetime, and A a precosheaf
of C*-algebras on X. Motivated by algebraic quantum field theory, we study the
Kasparov and Theta-summable K-homology of A interpreting them in terms of the
holonomy equivariant K-homology of the associated C*-dynamical system. This
yields a characteristic class for K-homology cycles of A with values in the odd
cohomology of X, that we interpret as a generalized statistical dimension.


title:
Towards First Principles prediction of Voltage Dependences of
  Electrolyte/Electrolyte Interfacial Processes in Lithium Ion Batteries

abstract:
  In lithium ion batteries, Li+ intercalation and processes associated with
passivation of electrodes are governed by applied voltages, which are in turn
associated with free energy changes of Li+ transfer (Delta G_t) between the
solid and liquid phases. Using ab initio molecular dynamics (AIMD) and
thermodynamic integration techniques, we compute Delta G_t for the virtual
transfer of a Li+ from a LiC(6) anode slab, with pristine basal planes exposed,
to liquid ethylene carbonate confined in a nanogap. The onset of delithiation,
at Delta G_t=0, is found to occur on LiC(6) anodes with negatively charged
basal surfaces. These negative surface charges are evidently needed to retain
Li+ inside the electrode, and should affect passivation ("SEI") film formation
processes. Fast electrolyte decomposition is observed at even larger electron
surface densities. By assigning the experimentally known voltage (0.1 V vs.
Li+/Li metal) to the predicted delithiation onset, an absolute potential scale
is obtained. This enables voltage calibrations in simulation cells used in AIMD
studies, and paves the way for future prediction of voltage dependences in
interfacial processes in batteries.


title: Transfer current and pattern fields in spanning trees

abstract:
  When a simply connected domain $D\subset{\mathbb{R}}^d$ ($d\ge 2$) is
approximated in a "good" way by embedded connected weighted graphs, we prove
that the transfer current matrix (defined on the edges of the graph viewed as
an electrical network) converges, up to a local weight factor, to the
differential of Green's function on $D$.
  This observation implies that properly rescaled correlations of the spanning
tree model and correlations of minimal subconfigurations in the abelian
sandpile model have a universal and conformally covariant limit.
  We further show that, on a periodic approximation of the domain, all pattern
fields of the spanning tree model, as well as the minimal-pattern (e.g.
zero-height) fields of the sandpile, converge weakly in distribution to
Gaussian white noise.


title:
The MICE Grand Challenge Lightcone Simulation III: Galaxy lensing mocks
  from all-sky lensing maps

abstract:
  In paper I of this series (Fosalba et al. 2013), we presented a new N-body
lightcone simulation from the MICE collaboration, the MICE Grand Challenge
(MICE-GC), containing about 70 billion dark-matter particles in a (3 Gpc)^3
comoving volume, from which we built halo and galaxy catalogues using a Halo
Occupation Distribution and Halo Abundance Matching technique, as presented in
the companion Paper II (Crocce et al. 2013). Given its large volume and fine
mass resolution, the MICE-GC simulation also allows an accurate modeling of the
lensing observables from upcoming wide and deep galaxy surveys. In the last
paper of this series (Paper III), we describe the construction of all-sky
lensing maps, following the "Onion Universe" approach (Fosalba et al. 2008),
and discuss their properties in the lightcone up to z=1.4 with sub-arcmin
spatial resolution. By comparing the convergence power spectrum in the MICE-GC
to lower mass-resolution (i.e., particle mass ~ 10^11 Msun) simulations, we
find that resolution effects are at the 5 % level for multipoles l ~ 10^3 and
20 % for l ~ 10^4. Resolution effects have a much lower impact on our
simulation, as shown by comparing the MICE-GC to recent numerical fits by
Takahashi et al 2012. We use the all-sky lensing maps to model galaxy lensing
properties, such as the convergence, shear, and lensed magnitudes and
positions, and validate them thoroughly using galaxy shear auto and
cross-correlations in harmonic and configuration space. Our results show that
the galaxy lensing mocks here presented can be used to accurately model lensing
observables down to arcminute scales.


title: Resolving Witten's Superstring Field Theory

abstract:
  We regulate Witten's open superstring field theory by replacing the
picture-changing insertion at the midpoint with a contour integral of picture
changing insertions over the half-string overlaps of the cubic vertex. The
resulting product between string fields is non-associative, but we provide a
solution to the $A_\infty$ relations defining all higher vertices. The result
is an explicit covariant superstring field theory which by construction
satisfies the classical BV master equation.


title: A Survey of Embedded Software Profiling Methodologies

abstract:
  Embedded Systems combine one or more processor cores with dedicated logic
running on an ASIC or FPGA to meet design goals at reasonable cost. It is
achieved by profiling the application with variety of aspects like performance,
memory usage, cache hit versus cache miss, energy consumption, etc. Out of
these, performance estimation is more important than others. With ever
increasing system complexities, it becomes quite necessary to carry out
performance estimation of embedded software implemented in a particular
processor for fast design space exploration. Such profiled data also guides the
designer how to partition the system for Hardware (HW) and Software (SW)
environments. In this paper, we propose a classification for currently
available Embedded Software Profiling Tools, and we present different academic
and industrial approaches in this context. Based on these observations, it will
be easy to identify such common principles and needs which are required for a
true Software Profiling Tool for a particular application.


title: Revisiting the two-mass model of the vocal folds

abstract:
  Realistic mathematical modeling of voice production has been recently boosted
by applications to different fields like bioprosthetics, quality speech
synthesis and pathological diagnosis. In this work, we revisit a two-mass model
of the vocal folds that includes accurate fluid mechanics for the air passage
through the folds and nonlinear properties of the tissue. We present the
bifurcation diagram for such a system, focusing on the dynamical properties of
two regimes of interest: the onset of oscillations and the normal phonation
regime. We also show theoretical support to the nonlinear nature of the elastic
properties of the folds tissue by comparing theoretical isofrequency curves
with reported experimental data.


title:
Intersubband Electronic Properties of InAs/GaAs Quantum Dot Molecules
  with Horizontal Spacer

abstract:
  In this work the intersubband electronic properties of two laterally coupled
dome-shaped InAs/GaAs quantum dots were investigated. The envelope functions
and eigenenergies were calculated as function of distance between the dots. The
coupling between the dots was studied using transition lifetime between the
dots. The results showed that in close distances (smaller than 3 nm) the
quantum dots are coupled and by increasing the distance transition lifetime
fall down drastically and the dots become uncoupled.


title:
Constraining the origin of the rising cosmic ray positron fraction with
  the boron-to-carbon ratio

abstract:
  The rapid rise in the cosmic ray positron fraction above 10 GeV, as measured
by PAMELA and AMS, suggests the existence of nearby primary sources of high
energy positrons, such as pulsars or annihilating/decaying dark matter. In
contrast, the spectrum of secondary positrons produced through the collisions
of cosmic rays in the interstellar medium is predicted to fall rapidly with
energy, and thus is unable to account for the observed rise. It has been
proposed, however, that secondary positrons could be produced and then
accelerated in nearby supernova remnants, potentially explaining the observed
rise, without the need of primary positron sources. Yet, if secondary positrons
are accelerated in such shocks, other secondary cosmic ray species (such as
boron nuclei, and antiprotons) will also be accelerated, leading to rises in
the boron-to-carbon and antiproton-to-proton ratios. The measurements of the
boron-to-carbon ratio by the PAMELA and AMS collaborations, however, show no
sign of such a rise. With this new data in hand, we revisit the secondary
acceleration scenario for the rising positron fraction. Assuming that the same
supernova remnants accelerate both light nuclei (protons, helium) and heavier
cosmic ray species, we find that no more than ~25% of the observed rise in the
positron fraction can result from this mechanism (at the 95% confidence level)


title:
Pre-merger localization of eccentric compact binary coalescences with
  second-generation gravitational-wave detector networks

abstract:
  We study the possibility of pre-merger localization of eccentric compact
binary coalescences by second-generation gravitational-wave detector networks.
Gravitational waves from eccentric binaries can be regarded as a sequence of
pulses, which are composed of various higher harmonic modes than ones with
twice the orbital frequency. The higher harmonic modes from a very early
inspiral phase will not only contribute to the signal-to-noise ratio, but also
allow us to localize the gravitational-wave source before the merger sets in.
This is due to the fact that high-frequency gravitational waves are essential
for the source localization via triangulation by ground-based detector
networks. We found that the single-detector signal-to-noise ratio exceeds 5 at
10 min before the merger for a 1.4--1.4 $M_\odot$ eccentric binary neutron
stars at 100 Mpc in optimal cases, and it can be localized up to 10 deg$^2$ at
half a minute before the merger by a four-detector network. We will even be
able to achieve $\sim$ 10 deg$^2$ at 10 min before the merger for a face-on
eccentric compact binary by a five-detector network.


title:
Friends of Hot Jupiters I: A Radial Velocity Search for Massive,
  Long-Period Companions to Close-In Gas Giant Planets

abstract:
  In this paper we search for distant massive companions to known transiting
gas giant planets that may have influenced the dynamical evolution of these
systems. We present new radial velocity observations for a sample of 51 planets
obtained using the Keck HIRES instrument, and find statistically significant
accelerations in fifteen systems. Six of these systems have no previously
reported accelerations in the published literature: HAT-P-10, HAT-P-22,
HAT-P-29, HAT-P-32, WASP-10, and XO-2. We combine our radial velocity fits with
Keck NIRC2 adaptive optics (AO) imaging data to place constraints on the
allowed masses and orbital periods of the companions responsible for the
detected accelerations. The estimated masses of the companions range between
1-500 M_Jup, with orbital semi-major axes typically between 1-75 AU. A
significant majority of the companions detected by our survey are constrained
to have minimum masses comparable to or larger than those of the transiting
planets in these systems, making them candidates for influencing the orbital
evolution of the inner gas giant. We estimate a total occurrence rate of 51 +/-
10% for companions with masses between 1-13 M_Jup and orbital semi-major axes
between 1-20 AU in our sample. We find no statistically significant difference
between the frequency of companions to transiting planets with misaligned or
eccentric orbits and those with well-aligned, circular orbits. We combine our
expanded sample of radial velocity measurements with constraints from transit
and secondary eclipse observations to provide improved measurements of the
physical and orbital characteristics of all of the planets included in our
survey.


title:
Probing CP Violation in $h\rightarrow\gamma\gamma$ with Converted
  Photons

abstract:
  We study Higgs diphoton decays, in which both photons undergo nuclear
conversion to electron- positron pairs. The kinematic distribution of the two
electron-positron pairs may be used to probe the CP violating (CPV) coupling of
the Higgs to photons, that may be produced by new physics. Detecting CPV in
this manner requires interference between the spin-polarized helicity
amplitudes for both conversions. We derive leading order, analytic forms for
these amplitudes. In turn, we obtain compact, leading-order expressions for the
full process rate. While performing experiments involving photon conversions
may be challenging, we use the results of our analysis to construct
experimental cuts on certain observables that may enhance sensitivity to CPV.
We show that there exist regions of phase space on which sensitivity to CPV is
of order unity. The statistical sensitivity of these cuts are verified
numerically, using dedicated Monte-Carlo simulations.


title: Longitudinal Coherence in a Holographic Model of p-Pb Collisions

abstract:
  As a model of the longitudinal structure in heavy ion collisions, we simulate
gravitational shock wave collisions in anti-de Sitter space in which each shock
is composed of multiple constituents. We find that all constituents act
coherently, and their separation leaves no imprint on the resulting plasma,
when this separation is $\lesssim 0.26 / T_{hyd}$, with $T_{hyd}$ the
temperature of the plasma at the time when hydrodynamics first becomes
applicable. In particular, the center-of-mass of the plasma coincides with the
center-of-mass of all the constituents participating in the collision, as
opposed to the center-of-mass of the individual collisions. We discuss the
implications for nucleus-nucleus and proton-nucleus collisions.


title: The effective field theory of multi-component fluids

abstract:
  We study the effective Lagrangian, at leading order in derivatives, that
describes the propagation of density and metric fluctuations in a fluid
composed by an arbitrary number of interacting components. Our results can be
applied to any situation in cosmology where different species have
non-gravitational interactions. In time-dependent backgrounds, such as FLRW,
the quadratic action can only be diagonalized at fixed time slices and flavour
mixing is unavoidable as time flows. In spite of this, the fluid can be
interpreted at the level of the linear equations of motion as an ensemble of
individual interacting species. We show that interactions lead to anisotropic
stresses that depend on the mixing terms in the quadratic action for
perturbations. In addition to the standard entrainment among different
components, we find a new operator in the effective action that behaves as a
cosmological constant when it dominates the dynamics.


title:
Near-infrared counterparts to the Galactic Bulge Survey X-ray source
  population

abstract:
  We report on the near-infrared matches, drawn from three surveys, to the 1640
unique X-ray sources detected by Chandra in the Galactic Bulge Survey (GBS).
This survey targets faint X-ray sources in the Bulge, with a particular focus
on accreting compact objects. We present all viable counterpart candidates and
associate a false alarm probability (FAP) to each near-infrared match in order
to identify the most likely counterparts. The false alarm probability takes
into account a statistical study involving a chance alignment test, as well as
considering the positional accuracy of the individual X-ray sources. We find
that although the star density in the Bulge is very high, ~90% of our sources
have a false alarm probability < 10%, indicating that for most X-ray sources,
viable near-infrared counterparts candidates can be identified. In addition to
the FAP, we provide positional and photometric information for candidate
counterparts to ~95% of the GBS X-ray sources. This information in combination
with optical photometry, spectroscopy and variability constraints will be
crucial to characterize and classify secure counterparts.


title:
The complete one-loop dilatation operator of planar real beta-deformed
  N=4 SYM theory

abstract:
  We determine the missing finite-size corrections to the asymptotic one-loop
dilatation operator of the real $\beta$-deformed $\mathcal{N}=4$ SYM theory for
the gauge groups $U(N)$ and $SU(N)$ in the 't Hooft limit. In the $SU(N)$ case,
the absence of the $U(1)$ field components leads to a new kind of finite-size
effect, which we call prewrapping. We classify which states are potentially
affected by prewrapping at generic loop orders and comment on the necessity to
include it into the integrability-based description. As a further result, we
identify classes of $n$-point correlation functions which at all loop orders in
the planar theory are given by the values of their undeformed counterparts.
Finally, we determine the superconformal multiplet structure and one-loop
anomalous dimensions of all single-trace states with classical scaling
dimension $\Delta_0 \leq 4.5$.


title: BPS Skyrme model and nuclear binding energies

abstract:
  We use the classical BPS soliton solutions of the BPS Skyrme model together
with corrections from the collective coordinate quantization of spin and
isospin, the electrostatic Coulomb energies, and a small explicit breaking of
the isospin symmetry - accounting for the proton-neutron mass difference - to
calculate nuclear binding energies. We find that the resulting binding energies
are already in excellent agreement with their physical values for heavier
nuclei, demonstrating thereby that the BPS Skyrme model is a distinguished
starting point for a detailed quantitative investigation of nuclear and
low-energy strong interaction physics.


title: Delaying the waterfall transition in warm hybrid inflation

abstract:
  We analyze the dynamics and observational predictions of supersymmetric
hybrid inflation in the warm regime, where dissipative effects are mediated by
the waterfall fields and their subsequent decay into light degrees of freedom.
This produces a quasi-thermal radiation bath with a slowly-varying temperature
during inflation and further damps the inflaton's motion, thus prolonging
inflation. As in the standard supercooled scenario, inflation ends when the
waterfall fields become tachyonic and can no longer sustain a nearly constant
vacuum energy, but the interaction with the radiation bath makes the waterfall
fields effectively heavier and delays the phase transition to the
supersymmetric minimum. In this work, we analyze for the first time the effects
of finite temperature corrections and SUSY mass splittings on the quantum
effective potential and the resulting dissipation coefficient. We show, in
particular, that dissipation can significantly delay the onset of the tachyonic
instability to yield 50-60 e-folds of inflation and an observationally
consistent primordial spectrum, which is not possible in the standard
supercooled regime when inflation is driven by radiative corrections.


title: Unexpected D-type Interlopers in the Inner Main Belt

abstract:
  Very red featureless asteroids (spectroscopic D-types) are expected to have
formed in the outer solar system far from the sun. They comprise the majority
of asteroids in the Jupiter Trojan population, and are also commonly found in
the outer main belt and among Hildas. The first evidence for D-types in the
inner and middle parts of the main belt was seen in the Sloan Digital Sky
Survey (SDSS). Here we report follow-up observations of SDSS D-type candidates
in the near-infrared. Based on follow up observations of 13 SDSS D-type
candidates, we find a ~20% positive confirmation rate. Known inner belt D-types
range in diameter from roughly 7 to 30 kilometers. Based on these detections we
estimate there are ~100 inner belt D-types with diameters between 2.5 and 20km.
The lower and upper limits for total mass of inner belt D-types is 2x$10^{16}$
kg to 2x$10^{17}$ kg which represents 0.01% to 0.1% of the mass of the inner
belt. The inner belt D-types have albedos at or above the upper end typical for
D-types which raises the question as to whether these inner belt bodies
represent only a subset of D-types, they have been altered by external factors
such as weathering processes, or if they are compositionally distinct from
other D-types. All D-types and candidates have diameters less than 30km, yet
there is no obvious parent body in the inner belt. Dynamical models have yet to
show how D-types originating from the outer solar system could penetrate into
the inner reaches of the Main Belt under current scenarios of planet formation
and subsequent Yarkovsky drift.


title: Observation of a Dissipation-Induced Classical to Quantum Transition

abstract:
  We report here the experimental observation of a dynamical quantum phase
transition in a strongly interacting open photonic system. The system studied,
comprising a Jaynes-Cummings dimer realized on a superconducting circuit
platform, exhibits a dissipation driven localization transition. Signatures of
the transition in the homodyne signal and photon number reveal this transition
to be from a regime of classical oscillations into a macroscopically
self-trapped state manifesting revivals, a fundamentally quantum phenomenon.
This experiment also demonstrates a small-scale realization of a new class of
quantum simulator, whose well controlled coherent and dissipative dynamics is
suited to the study of quantum many-body phenomena out of equilibrium.

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


title:
Large deviations and Gallavotti-Cohen principle for dissipative PDE's
  with rough noise

abstract:
  We study a class of dissipative PDE's perturbed by an unbounded kick force.
Under some natural assumptions, the restrictions of solutions to integer times
form a homogeneous Markov process. Assuming that the noise is rough with
respect to the space variables and has a non-degenerate law, we prove that the
system in question satisfies a large deviation principle in tau-topology. Under
some additional hypotheses, we establish a Gallavotti-Cohen type symmetry for
the rate function of an entropy production functional and the strict positivity
and finiteness of the mean entropy production in the stationary regime. The
latter result is applicable to PDE's with strong nonlinear dissipation.

categories: math-ph cond-mat.stat-mech math.AP math.MP math.PR


title:
An Investigation of the CME of 3 November 2011 and its Associated
  Widespread Solar Energetic Particle Event

abstract:
  Multi-spacecraft observations are used to study the in-situ effects of a
large CME erupting from the farside of the Sun on 3 November 2011, with
particular emphasis on the associated solar energetic particle (SEP) event. At
that time both Solar Terrestrial Relations Observatory (STEREO) spacecraft were
located more than 90 degrees from Earth and could observe the CME eruption
directly, with the CME visible on-disk from STEREO-B and off the limb from
STEREO-A. Signatures of pressure variations in the corona such as deflected
streamers were seen, indicating the presence of a coronal shock associated with
this CME eruption. The evolution of the CME and an associated EUV wave were
studied using EUV and coronagraph images. It was found that the lateral
expansion of the CME low in the corona closely tracked the propagation of the
EUV wave, with measured velocities of 240+/-19 km/s and 221+/-15 km/s for the
CME and wave respectively. Solar energetic particles were observed arriving
first at STEREO-A, followed by electrons at the Wind spacecraft at L1, then
STEREO-B, and finally protons arriving simultaneously at Wind and STEREO-B. By
carrying out velocity-dispersion analysis on the particles arriving at each
location, it was found that energetic particles arriving at STEREO-A were
released first and the release of particles arriving at STEREO-B was delayed by
around 50 minutes. Analysis of the expansion of the CME to a wider longitude
indicates that this delay is a result of the time taken for the edge of the CME
to reach the footpoints of the magnetic-field lines connected to STEREO-B. The
CME expansion is not seen to reach the magnetic footpoint of Wind at the time
of solar particle release for the particles detected here, suggesting that
these particles may not be associated with this CME.


title: Near-extreme eigenvalues and the first gap of Hermitian random matrices

abstract:
  We study the phenomenon of "crowding" near the largest eigenvalue
$\lambda_{\max}$ of random $N \times N$ matrices belonging to the Gaussian
Unitary Ensemble (GUE) of random matrix theory. We focus on two distinct
quantities: (i) the density of states (DOS) near $\lambda_{\max}$, $\rho_{\rm
DOS}(r,N)$, which is the average density of eigenvalues located at a distance
$r$ from $\lambda_{\max}$ and (ii) the probability density function of the gap
between the first two largest eigenvalues, $p_{\rm GAP}(r,N)$. In the edge
scaling limit where $r = {\cal O}(N^{-1/6})$, which is described by a double
scaling limit of a system of unconventional orthogonal polynomials, we show
that $\rho_{\rm DOS}(r,N)$ and $p_{\rm GAP}(r,N)$ are characterized by scaling
functions which can be expressed in terms of the solution of a Lax pair
associated to the Painlev\'e XXXIV equation. This provides an alternative and
simpler expression for the gap distribution, which was recently studied by
Witte, Bornemann and Forrester in Nonlinearity 26, 1799 (2013). Our expressions
allow to obtain precise asymptotic behaviors of these scaling functions both
for small and large arguments.

categories: math-ph cond-mat.dis-nn cond-mat.stat-mech math.MP math.PR


title: Every LWF and AMP chain graph originates from a set of causal models

abstract:
  This paper aims at justifying LWF and AMP chain graphs by showing that they
do not represent arbitrary independence models. Specifically, we show that
every chain graph is inclusion optimal wrt the intersection of the independence
models represented by a set of directed and acyclic graphs under conditioning.
This implies that the independence model represented by the chain graph can be
accounted for by a set of causal models that are subject to selection bias,
which in turn can be accounted for by a system that switches between different
regimes or configurations.


title:
Adaptive confidence intervals for the tail coefficient in a wide second
  order class of Pareto models

abstract:
  We study the problem of constructing honest and adaptive confidence intervals
for the tail coefficient in the second order Pareto model, when the second
order coefficient is unknown. This problem is translated into a testing problem
on the second order parameter. By constructing an appropriate model and an
associated test statistic, we provide a uniform and adaptive confidence
interval for the first order parameter. We also provide an almost matching
lower bound, which proves that the result is minimax optimal up to a
logarithmic factor.


title: Lattice solitons with quadrupolar intersite interactions

abstract:
  We study two-dimensional (2D) solitons in the mean-field models of ultracold
gases with long-range quadrupole-quadrupole interaction (QQI) between
particles. The condensate is loaded into a deep optical-lattice (OL) potential,
therefore the model is based on the 2D discrete nonlinear Schr\"{o}dinger
equation with contact onsite and long-range intersite interactions, which
represent the QQI. The quadrupoles are built as pairs of electric dipoles and
anti-dipoles orientated perpendicular to the 2D plane to which the gas is
confined. Because the quadrupoles interact with the local gradient of the
external field, they are polarized by inhomogeneous dc electric field that may
be supplied by a tapered capacitor. Shapes, stability, mobility, and collisions
of fundamental discrete solitons are studied by means of systematic
simulations. In particular, threshold values of the norm, necessary for the
existence of the solitons, are found, and anisotropy of their static and
dynamical properties is explored. As concerns the mobility and collisions, it
is the first analysis of such properties for discrete solitons on 2D lattices
with long-range intersite interactions of any type. Estimates demonstrate that
the setting can be realized under experimentally available conditions,
predicting solitons built of $\sim$ 10,000 particles.


title: Refinements to Mumford's theta and adelic theta groups

abstract:
  Let $X$ be an abelian variety defined over an algebraically closed field $k$.
We consider theta groups associated to \emph{simple semi-homogenous vector
bundles of separable type} on $X$. We determine the structure and
representation theory of these groups. In doing so we relate work of Mumford,
Mukai, and Umemura. We also consider adelic theta groups associated to line
bundles on $X$. After reviewing Mumford's construction of these groups we
determine functorial properties which they enjoy and then realize the
Neron-Severi group of $X$ as a subgroup of the cohomology group $\H^2(\V(X);
k^\times)$.


title: On s-sets in spaces of homogeneous type

abstract:
  Let $(X,d,\mu)$ be a space of homogeneous type. In this note we study the
relationship between two types of $s$-sets: relative to a distance and relative
to a measure. We find a condition on a closed subset $F$ of $X$ under which we
have that $F$ is $s$-set relative to the measure $\mu$ if and only if $F$ is
$s$-set relative to $\delta$. Here $\delta$ denotes the quasi-distance defined
by Mac\'ias and Segovia such that $(X,\delta,\mu)$ is a normal space. In order
to prove this result, we show a covering type lemma and a type of Hausdorff
measure based criteria for the $s$-set condition relative to $\mu$ of a given
set.