title: Ionization driven molecular outflow in K3-50A

abstract:
  Whether high mass stars continue to accrete material beyond the formation of
an HII region is still an open question. Ionized infall and outflow have been
seen in some sources, but their ties to the surrounding molecular gas are not
well constrained. We aim to quantify the ionized and molecular gas dynamics in
a high mass star forming region (K3-50A) and their interaction.
  We present CARMA observations of the 3mm continuum, H41\alpha, and HCO+
emission, and VLA continuum observations at 23 GHz and 14.7 GHz to quantify the
gas and its dynamics in K3-50A. We find large scale dynamics consistent with
previous observations. On small scales, we find evidence for interaction
between the ionized and molecular gas which suggests the ionized outflow is
entraining the molecular one. This is the first time such an outflow entrained
by photo ionized gas has been observed.
  Accretion may be ongoing in K3-50A because an ionized bipolar outflow is
still being powered, which is in turn entraining part of the surrounding
molecular gas. This outflow scenario is similar to that predicted by ionization
feedback models.


title:
Bifurcation of critical points for continuous families of C^2
  functionals of Fredholm type

abstract:
  Given a continuous family of C^2 functionals of Fredholm type, we show that
the non-vanishing of the spectral flow for the family of Hessians along a known
(trivial) branch of critical points not only entails bifurcation of nontrivial
critical points but also allows to estimate the number of bifurcation points
along the branch. We use this result for several parameter bifurcation,
estimating the number of connected components of the complement of the set of
bifurcation points and apply our results to bifurcation of periodic orbits of
Hamiltonian systems. By means of a comparison principle for the spectral flow,
we obtain lower bounds for the number of bifurcation points of periodic orbits
on a given interval in terms of the coefficients of the linearization.


title:
Detecting the rapidly expanding outer shell of the Crab Nebula: where to
  look

abstract:
  We present a range of steady-state photoionization simulations, corresponding
to different assumed shell geometries and compositions, of the unseen
postulated rapidly expanding outer shell to the Crab Nebula. The properties of
the shell are constrained by the mass that must lie within it, and by limits to
the intensities of hydrogen recombination lines. In all cases the
photoionization models predict very strong emission from high ionization lines
that will not be emitted by the Crab's filaments, alleviating problems with
detecting these lines in the presence of light scattered from brighter parts of
the Crab. The NIR [Ne VI] $\lambda$7.652 $\mu$m line is a particularly good
case; it should be dramatically brighter than the optical lines commonly used
in searches. The C IV $\lambda1549\AA$ doublet is predicted to be the strongest
absorption line from the shell, which is in agreement with HST observations. We
show that the cooling timescale for the outer shell is much longer than the age
of the Crab, due to the low density. This means that the temperature of the
shell will actually "remember" its initial conditions. However, the
recombination time is much shorter than the age of the Crab, so the predicted
level of ionization should approximate the real ionization. In any case, it is
clear that IR observations present the best opportunity to detect the outer
shell and so guide future models that will constrain early events in the
original explosion.


title: Some remarks concerning the Grothendieck Period Conjecture

abstract:
  We discuss various results and questions around the Grothendieck period
conjecture, which is a counterpart, concerning the de Rham-Betti realization of
algebraic varieties over number fields, of the classical conjectures of Hodge
and Tate. These results give new evidence towards the conjectures of
Grothendieck and Kontsevich-Zagier concerning transcendence properties of the
torsors of periods of varieties over number fields.
  We notably establish that the Grothendieck period conjecture holds in degree
1 for products of curves, of abelian varieties, and of K3 surfaces, and that it
holds in degree 2 for smooth cubic fourfolds.


title:
Turbulent pattern formation and diffusion in the early-time dynamics in
  the relativistic heavy-ion collision

abstract:
  We propose a picture of turbulent pattern formation in the relativistic
heavy-ion collision, which follows an efficient process to break color strings
and dispose energy in the whole phase space. We perform numerical simulations
using the SU(2) pure Yang-Mills theory in a non-expanding box to observe a
dynamical phenomenon in the transverse plane akin to the domain growth in
time-dependent spin systems.


title: On Semilinear Elliptic Equation with Measurable Nonlinearity

abstract:
  We consider a semilinear elliptic equation in a bounded domain with zero
boundary conditions. The nonlinearity is discontinuous and monotone, but it is
not a Carath\'eodory's function. The existence theorem has been proved.


title: High resolution mapping of CO(1-0) in NGC6240

abstract:
  We present high spatial resolution CO(1-0) mapping of the luminous infrared
galaxy NGC6240 obtained with the IRAM - Plateau de Bure Interferometer. This
source is a well-known early-stage merging system hosting two AGN. We find a
broad CO(1-0) line profile, with maximum velocity 800 km/s and FWZI=1400 km/s,
and displaying several kinematic components, revealing the complexity of the
gas dynamics in this system. We detect a blueshifted CO emission with velocity
in the range -200 and -500 km/s, peaked around the southern AGN, at the same
position where the H2 outflow is located, and with a mass loss rate of ~500
Msun/yr. We interpret this blueshifted component as a outflow, originating from
the southern nucleus. The spatial and spectral match strongly suggests that the
CO outflow is connected to the H2 superwind located around the southern
nucleus, and to the large scale CO outflow, with similar velocities, extended
on scales of 10 kpc. The large mass loading factor (dM/dt /SFR ~ 10) of the
molecular gas suggests that the outflow is likely driven by both SNa winds and
the radiation of the southern AGN. We discovered a nuclear, redshifted CO
emission peaking in the mid point of the two nuclei, as it is the case for the
CO emission at the systemic velocity. The large velocity dispersion, which
reaches its maximum (~500 Km/s) in the mid point between the two nuclei,
suggests that the gas might be highly turbulent in this region, although the
presence of an unresolved rotation component cannot be ruled out.


title:
A low-luminosity type-1 QSO sample - A morphological study of nearby AGN
  hosts

abstract:
  There is growing evidence that every galaxy with a considerable spheroidal
component hosts a supermassive black hole (SMBH) at its center. Strong
correlations between the SMBH and the spheroidal component suggest a physical
connection through a coevolutionary scenario. For very massive galaxies a
merger-driven scenario is preferred, resulting in elliptical galaxies. In the
nearby universe, we find many disk galaxies, showing no signs of recent
interaction. Alternative secular evolutionary scenarios for such galaxies
involve internal triggers like bars and spiral arms or minor mergers. We
analyze a sample of 99 nearby galaxies (0.02 < z < 0.06) from the Hamburg/ESO
survey in order to get insight into structural and dynamical properties of the
hosts to trace the origin of the bulge-SMBH correlation. In this work, we first
collect images of sample members to get an impression of the morphological
distribution in the sample. In a second step, we start to analyze sensitive,
high resolution near-infrared images of 20 galaxies, performing aperture
photometry and bulge-disk decomposition with the BUDDA code. We find an
unexpected high fraction of barred galaxies and many other structural
peculiarities.


title:
Consequences the extensive use of multiple-choice questions might have
  on student's reasoning structure

abstract:
  Learning physics is a context dependent process. I consider a broader
interdisciplinary problem of where differences in understanding and reasoning
arise. I suggest the long run effects a multiple choice based learning system
as well as society cultural habits and rules might have on student reasoning
structure.


title: Byzantine Convex Consensus: Preliminary Version

abstract:
  Much of the past work on asynchronous approximate Byzantine consensus has
assumed scalar inputs at the nodes [3, 7]. Recent work has yielded approximate
Byzantine consensus algorithms for the case when the input at each node is a
d-dimensional vector, and the nodes must reach consensus on a vector in the
convex hull of the input vectors at the fault-free nodes [8, 12]. The
d-dimensional vectors can be equivalently viewed as points in the d-dimensional
Euclidean space. Thus, the algorithms in [8, 12] require the fault-free nodes
to decide on a point in the d-dimensional space.
  In this paper, we generalize the problem to allow the decision to be a convex
polytope in the d-dimensional space, such that the decided polytope is within
the convex hull of the input vectors at the fault-free nodes. We name this
problem as Byzantine convex consensus (BCC), and present an asynchronous
approximate BCC algorithm with optimal fault tolerance. Ideally, the goal here
is to agree on a convex polytope that is as large as possible. While we do not
claim that our algorithm satisfies this goal, we show a bound on the output
convex polytope chosen by our algorithm.


title: Phonon-roton modes of liquid 4He beyond the roton in MCM-41

abstract:
  We present neutron scattering measurements of the phonon-roton (P-R) mode of
superfluid 4He confined in 47 \AA MCM-41 at T = 0.5 K at wave vectors, Q,
beyond the roton wave vector (Q_R =1.92 \AA$^{-1}$). Measurements beyond the
roton require access to high wave vectors (up to Q = 4 \AA$^{-1}$) with
excellent energy resolution and high statistical precision. The present results
show for the first time that at T = 0.5 K the P-R mode in MCM-41 extends out to
wave-vector Q$\simeq$3.6 \AA$^-1$ with the same energy and zero width (within
precision) as observed in bulk superfluid 4He. Layer modes in the roton region
are also observed. Specifically, the P-R mode energy, $\omega_Q$, increases
with Q for Q > QR and reaches a plateau at a maximum energy Q = 2{\Delta} where
{\Delta} is the roton energy, {\Delta} = 0.74 $\pm$ 0.01 meV in MCM-41. This
upper limit means the P-R mode decays to two rotons when its energy exceeds
2{\Delta}. It also means that the P-R mode does not decay to two layers modes.
If the P-R could decay to two layer modes, $\omega_Q$ would plateau at a lower
energy, $\omega_Q$ = 2{\Delta}L where {\Delta}L = 0.60 meV is the energy of the
roton like minimum of the layer mode. The observation of the P-R mode with
energy up to 2{\Delta} shows that the P-R mode and the layer modes are
independent modes with apparently little interaction between them.


title: Inequalities for nonnegative numbers and information properties

abstract:
  We discuss some inequalities for N nonnegative numbers. We use these
inequalities to obtain known inequalities for probability distributions and new
entropic and information inequalities for quantum tomograms of qudit states.
The inequalities characterize the degree of quantum correlations in addition to
noncontextuality and quantum discord. We use the subadditivity and strong
subadditivity conditions for qudit tomographic-probability distributions
depending on the unitary-group parameters in order to derive new inequalities
for Shannon, Renyi, and Tsallis entropies of spin states.


title:
Geometric realization of toroidal quadrangulations without hidden
  symmetries

abstract:
  It is shown that each quadrangulation of the 2-torus by the Cartesian product
of two cycles can be geometrically realized in (Euclidean) 4-space without
hidden symmetries---that is, so that each combinatorial cellular automorphism
of the quadrangulation extends to a geometric symmetry of its Euclidean
realization. Such realizations turn out to be new regular toroidal geometric
2-polyhedra which are inscribed in the Clifford 2-torus in 4-space, just as the
five regular spherical 2-polyhedra are inscribed in the 2-sphere in 3-space.
The following are two open problems: Realize geometrically (1) the regular
triangulations and (2) the regular hexagonizations of the 2-torus without
hidden symmetries in 4-space.


title: Characterisations of the weak expectation property

abstract:
  We use representations of operator systems as quotients to deduce various
characterisations of the weak expectation property (WEP) for C?*-algebras. By
Kirchberg's work on WEP, these results give new formulations of Connes'
embedding problem.


title: Scalar conservation laws on moving hypersurfaces

abstract:
  We consider conservation laws on moving hypersurfaces. In this work the
velocity of the surface is prescribed. But one may think of the velocity to be
given by PDEs in the bulk phase. We prove existence and uniqueness for a scalar
conservation law on the moving surface. This is done via a parabolic
regularization of the hyperbolic PDE. We then prove suitable estimates for the
solution of the regularized PDE, that are independent of the regularization
parameter. We introduce the concept of an entropy solution for a scalar
conservation law on a moving hypersurface. We also present some numerical
experiments. As in the Euclidean case we expect discontinuous solutions, in
particular shocks. It turns out that in addition to the "Euclidean shocks"
geometrically induced shocks may appear.


title:
A geometric tangential approach to sharp regularity for degenerate
  evolution equations

abstract:
  That the weak solutions of degenerate parabolic pdes modelled on the
inhomogeneous $p-$Laplace equation $$ u_t - \mathrm{div} \left(|\nabla u|^{p-2}
\nabla u \right) = f \in L^{q,r}, \quad p>2 $$ are $C^{0,\alpha}$, for some
$\alpha \in (0,1)$, is known for almost 30 years. What was hitherto missing
from the literature was a precise and sharp knowledge of the H\"older exponent
$\alpha$ in terms of $p, q, r$ and the space dimension $n$. We show in this
paper that $$ \alpha = \frac{(pq-n)r-pq}{q[(p-1)r-(p-2)]}, $$ using a method
based on the notion of geometric tangential equations and the intrinsic scaling
of the $p-$parabolic operator. The proofs are flexible enough to be of use in a
number of other nonlinear evolution problems.


title: On the minimal teaching sets of two-dimensional threshold functions

abstract:
  It is known that a minimal teaching set of any threshold function on the
twodimensional rectangular grid consists of 3 or 4 points. We derive exact
formulae for the numbers of functions corresponding to these values and further
refine them in the case of a minimal teaching set of size 3. We also prove that
the average cardinality of the minimal teaching sets of threshold functions is
asymptotically 7/2.
  We further present corollaries of these results concerning some special
arrangements of lines in the plane.


title:
Self-Consistent Ion Cyclotron Anisotropy-Beta Relation for Solar Wind
  Protons

abstract:
  We derive a set of self-consistent marginally stable states for a system of
ion-cyclotron waves propagating parallel to the large-scale magnetic field
through a homogeneous proton-electron plasma. The proton distributions and the
wave dispersions are related through the condition that no further
ion-cyclotron resonant particle scattering or wave growth/damping may take
place. The thermal anisotropy of the protons in these states therefore defines
the threshold value for triggering the proton-cyclotron anisotropy instability.
A number of recent papers have noted that the anisotropy of solar wind protons
at 1 AU does not seem to be limited by the proton-cyclotron anisotropy
threshold, even at low plasma beta. However, this puzzle seems to be due solely
to the estimation of this anisotropy threshold under the assumption that the
protons have a bi-Maxwellian distribution. We note that bi-Maxwellian
distributions are never marginally stable to the resonant cyclotron
interaction, so these estimates do not represent physically valid thresholds.
The threshold anisotropies obtained from our marginally stable states are much
larger, as a function of proton parallel beta, than the bi-Maxwellian
estimates, and we show that the measured data remains below these more rigorous
thresholds. Thus, the results of this paper resolve the apparent contradiction
presented by the solar wind anisotropy observations at 1 AU: The bi-Maxwellian
anisotropies are not rigorous thresholds, and so do not limit the proton
distributions in the solar wind.


title: The Vincia Parton Shower

abstract:
  We summarize recent developments in the VINCIA parton shower. After a brief
review of the basics of the formalism, the extension of VINCIA to hadron
collisions is sketched. We then turn to improvements of the efficiency of
tree-level matching by making the shower history unique and by incorporating
identified helicities. We conclude with an overview of matching to one-loop
matrix elements.


title:
Recursive Bayesian Initialization of Localization Based on Ranging and
  Dead Reckoning

abstract:
  The initialization of the state estimation in a localization scenario based
on ranging and dead reckoning is studied. Specifically, we start with a
cooperative localization setup and consider the problem of recursively arriving
at a uni-modal state estimate with sufficiently low covariance such that
covariance based filters can be used to estimate an agent's state subsequently.
A number of simplifications/assumptions are made such that the estimation
problem can be seen as that of estimating the initial agent state given a
deterministic surrounding and dead reckoning. This problem is solved by means
of a particle filter and it is described how continual states and covariance
estimates are derived from the solution. Finally, simulations are used to
illustrate the characteristics of the method and experimental data are briefly
presented.


title:
On a theorem of Erd\H{o}s and Simonovits on graphs not containing the
  cube

abstract:
  The cube Q is the usual 8-vertex graph with 12 edges. Here we give a new
proof for a theorem of Erd\H{o}s and Simonovits concerning the Tur\'an number
of the cube. Namely, it is shown that e(G) < n^{8/5}+(2n)^{3/2} holds for any
n-vertex cube-free graph G. Our aim is to give a self-contained exposition. We
also point out the best known results and supply bipartite versions.


title:
Exotic matter influence on the polar quasi-normal modes of neutron stars
  with equations of state satisfying the $2 M_{\odot}$ constraint

abstract:
  In this paper we analyze the quasi-normal mode spectrum of realistic neutron
stars by studying the polar modes. In particular we study the spatial wI mode,
the f mode, and the fundamental p mode. The study has been done for 15
different equations of state containing exotic matter and satisfying the $2
M_{\odot}$ constraint. Since f and p modes couple to matter perturbations, the
influence of the presence of hyperons and quarks in the core of the neutron
stars is more significant than for the axial component. We present
phenomenological relations for the frequency and damping time with the
compactness of the neutron star. We also consider new phenomenological
relations between the frequency and damping time of the w mode and the f mode.
These new relations are independent of the equation of state, and could be used
to estimate the central pressure, mass or radius, and eventually constrain the
equation of state of neutron stars. To obtain these results we have developed a
new method based on the Exterior Complex Scaling technique with variable angle.


title: Constraints on the Scalar Sector of the Renormalizable Coloron Model

abstract:
  The renormalizable coloron model is the minimal extension of the standard
model color sector, in which the color gauge group is enlarged to SU(3)_{1c} x
SU(3)_{2c}. In this paper we discuss the constraints on this model derived from
the requirements of vacuum stability, tree-level unitarity, electroweak
precision measurements, and from LHC measurements of the properties of the
observed Higgs-like scalar boson. The combination of these theoretical and
experimental considerations strongly constrains the allowed parameter space.
(Erratum appended, March 2014.)


title: The Combinatorics of Flat Folds: a Survey

abstract:
  We survey results on the foldability of flat origami models. The main topics
are the question of when a given crease pattern can fold flat, the
combinatorics of mountain and valley creases, and counting how many ways a
given crease pattern can be folded. In particular, we explore generalizations
of Maekawa's and Kawasaki's Theorems, develop a necessary and sufficient
condition for a given assignment of mountains and valleys to fold up in a
special case of single vertex folds, and describe recursive formulas to
enumerate the number of ways that single vertex in a crease pattern can be
folded.


title:
Thermal and Electrical Transport across a Magnetic Quantum Critical
  Point

abstract:
  A quantum critical point (QCP) arises at a continuous transition between
competing phases at zero temperature. Collective excitations at magnetic QCPs
give rise to metallic properties that strongly deviate from the expectations of
Landau's Fermi liquid description, the standard theory of electron correlations
in metals. Central to this theory is the notion of quasiparticles, electronic
excitations which possess the quantum numbers of the bare electrons. Here we
report measurements of thermal and electrical transport across the
field-induced magnetic QCP in the heavy-fermion compound YbRh$_2$Si$_2$. We
show that the ratio of the thermal to electrical conductivities at the
zero-temperature limit obeys the Wiedemann-Franz (WF) law above the critical
field, $B_c$. This is also expected at $B < B_c$, where weak antiferromagnetic
order and a Fermi liquid phase form below 0.07 K ($B = 0$). However, at the
critical field the low-temperature electrical conductivity suggests a
non-Fermi-liquid ground state and exceeds the thermal conductivity by about
10%. This apparent violation of the WF law provides evidence for an
unconventional type of QCP at which the fundamental concept of Landau
quasiparticles breaks down. These results imply that Landau quasiparticles
break up, and that the origin of this disintegration is inelastic scattering
associated with electronic quantum critical fluctuations. Our finding brings
new insights into understanding deviations from Fermi-liquid behaviour
frequently observed in various classes of correlated materials.


title: The partial linear model in high dimensions

abstract:
  Partial linear models have been widely used as flexible method for modelling
linear components in conjunction with non-parametric ones. Despite the presence
of the non-parametric part, the linear, parametric part can under certain
conditions be estimated with parametric rate. In this paper, we consider a
high-dimensional linear part. We show that it can be estimated with oracle
rates, using the LASSO penalty for the linear part and a smoothness penalty for
the nonparametric part.


title:
Error Analysis of Semidiscrete Finite Element Methods for Inhomogeneous
  Time-Fractional Diffusion

abstract:
  We consider the initial boundary value problem for the inhomogeneous
time-fractional diffusion equation with a homogeneous Dirichlet boundary
condition and a nonsmooth right hand side data in a bounded convex polyhedral
domain. We analyze two semidiscrete schemes based on the standard Galerkin and
lumped mass finite element methods. Almost optimal error estimates are obtained
for right hand side data $f(x,t)\in L^\infty(0,T;\dot H^q(\Omega))$, $-1< q \le
1$, for both semidiscrete schemes. For lumped mass method, the optimal
$L^2(\Omega)$-norm error estimate requires symmetric meshes. Finally, numerical
experiments for one- and two-dimensional examples are presented to verify our
theoretical results.


title:
First-principles study on competing phases of silicene: Effect of
  substrate and strain

abstract:
  The stability and electronic structure of competing silicene phases under
in-plane compressive stress, either free-standing or on the ZrB$_2$(0001)
surface, has been studied by first-principles calculations. A particular
($\sqrt{3}\times\sqrt{3}$)-reconstructed structural modification was found to
be stable on the ZrB$_2$(0001) surface under epitaxial conditions. In contrast
to the planar and buckled forms of free-standing silicene, in this
"planar-like" phase, all but one of the Si atoms per hexagon reside in a single
plane. While without substrate, for a wide range of strain, this phase is
energetically less favorable than the buckled one, it is calculated to
represent the ground state on the ZrB$_2$(0001) surface. The atomic positions
are found to be determined by the interactions with the nearest neighbor Zr
atoms competing with Si-Si bonding interactions provided by the constraint of
the honeycomb lattice.


title: A Comparison of Non-stationary, Type-2 and Dual Surface Fuzzy Control

abstract:
  Type-1 fuzzy logic has frequently been used in control systems. However this
method is sometimes shown to be too restrictive and unable to adapt in the
presence of uncertainty. In this paper we compare type-1 fuzzy control with
several other fuzzy approaches under a range of uncertain conditions. Interval
type-2 and non-stationary fuzzy controllers are compared, along with 'dual
surface' type-2 control, named due to utilising both the lower and upper values
produced from standard interval type-2 systems. We tune a type-1 controller,
then derive the membership functions and footprints of uncertainty from the
type-1 system and evaluate them using a simulated autonomous sailing problem
with varying amounts of environmental uncertainty. We show that while these
more sophisticated controllers can produce better performance than the type-1
controller, this is not guaranteed and that selection of Footprint of
Uncertainty (FOU) size has a large effect on this relative performance.


title:
Comparison of the Mechanical Properties of Self-Assembled Langmuir
  Monolayers of Nanoparticles and Phospholipids

abstract:
  Nanoparticles with hydrophobic capping ligands and amphiphilic phospholipids
are both found to self-assemble into monolayer films when deposited on the air
water interface. By separately measuring the anisotropic stress response of
these films under uniaxial compression, we obtain both the 2D compressive and
shear moduli of a range of different thin nanoparticle and phospholipid films.
The compressive moduli of both nanoparticle and lipid films in the solid phase
are on the same order of magnitude, whereas the shear moduli of the lipid films
are found to be significantly lower. Additionally the moduli of the
nanoparticle films depended substantially on the polydispersity of the
constituent particles: broader size distribution lowered the stiffness of the
nanoparticle film.


title:
Suppression of the S-wave production of (3/2)^+ + (1/2)^- heavy meson
  pairs in e^+e^- annihilation

abstract:
  The heavy meson-antimeson pairs, where one is an excited $\bigl ({3 \over 2}
\bigr) ^+ $ meson and the other is a ground state $\bigl ({1 \over 2} \bigr)
^-$ meson, namely the pairs ($D_1(2420) \bar D$ + c.c.), ($D_1(2420) \bar D^*$
+ c.c.), ($D_2(2460) \bar D^*$ + c.c.) in the charm sector and ($B_1(5721) \bar
B$ + c.c.), ($B_1(5721) \bar B^*$ + c.c.), ($B_2(5747) \bar B^*$ + c.c.) in the
bottom sector, are allowed, by the quantum numbers, to be produced in the $S$
wave in $e^+e^-$ annihilation. We show, however, that such $S$-wave production
is forbidden by the heavy quark spin symmetry. Thus the yield of the considered
meson pairs in $e^+e^-$ annihilation should be significantly suppressed near
the respective thresholds. In our view, this substantially weakens the
arguments for considering the Y(4260) charmonium-like resonance as a $D_1 \bar
D$ molecular state.


title:
Modelling Reactive and Proactive Behaviour in Simulation: A Case Study
  in a University Organisation

abstract:
  Simulation is a well established what-if scenario analysis tool in
Operational Research (OR). While traditionally Discrete Event Simulation (DES)
and System Dynamics Simulation (SDS) are the predominant simulation techniques
in OR, a new simulation technique, namely Agent-Based Simulation (ABS), has
emerged and is gaining more attention. In our research we focus on discrete
simulation methods (i.e. DES and ABS). The contribution made by this paper is
the comparison of DES and combined DES/ABS for modelling human reactive and
different level of detail of human proactive behaviour in service systems. The
results of our experiments show that the level of proactiveness considered in
the model has a big impact on the simulation output. However, there is not a
big difference between the results from the DES and the combined DES/ABS
simulation models. Therefore, for service systems of the type we investigated
we would suggest to use DES as the preferred analysis tool.


title:
An experimental approach for investigating many-body phenomena in
  Rydberg-interacting quantum systems

abstract:
  Recent developments in the study of ultracold Rydberg gases demand an
advanced level of experimental sophistication, in which high atomic and optical
densities must be combined with excellent control of external fields and
sensitive Rydberg atom detection. We describe a tailored experimental system
used to produce and study Rydberg-interacting atoms excited from dense
ultracold atomic gases. The experiment has been optimized for fast duty cycles
using a high flux cold atom source and a three beam optical dipole trap. The
latter enables tuning of the atomic density and temperature over several orders
of magnitude, all the way to the Bose-Einstein condensation transition. An
electrode structure surrounding the atoms allows for precise control over
electric fields and single-particle sensitive field ionization detection of
Rydberg atoms. We review two experiments which highlight the influence of
strong Rydberg--Rydberg interactions on different many-body systems. First, the
Rydberg blockade effect is used to pre-structure an atomic gas prior to its
spontaneous evolution into an ultracold plasma. Second, hybrid states of
photons and atoms called dark-state polaritons are studied. By looking at the
statistical distribution of Rydberg excited atoms we reveal correlations
between dark-state polaritons. These experiments will ultimately provide a
deeper understanding of many-body phenomena in strongly-interacting regimes,
including the study of strongly-coupled plasmas and interfaces between atoms
and light at the quantum level.


title: Resonant exchange interaction in semiconductors

abstract:
  We present a non-perturbative calculation of indirect exchange interaction
between two paramagnetic impurities via 2D free carriers gas separated by a
tunnel barrier. The new method accounts for the impurity attractive potential
producing a bound state. The calculations show that for if the bound impurity
state energy lies within the energy range occupied by the free 2D carriers the
indirect exchange interaction is strongly enhanced due to resonant tunneling
and exceeds by a few orders of magnitude what one would expect from the
conventional RKKY approach.


title:
Placing Limits On The Transit Timing Variations Of Circumbinary
  Exoplanets

abstract:
  We present an efficient analytical method to predict the maximum transit
timing variations of a circumbinary exoplanet, given some basic parameters of
the host binary. We derive an analytical model giving limits on the potential
location of transits for coplanar planets orbiting eclipsing binaries, then
test it against numerical N-body simulations of a distribution of binaries and
planets. We also show the application of the analytic model to Kepler-16b, -34b
and -35b. The resulting method is fast, efficient and is accurate to
approximately 1% in predicting limits on possible times of transits over a
three-year observing campaign. The model can easily be used to, for example,
place constraints on transit timing while performing circumbinary planet
searches on large datasets. It is adaptable to use in situations where some or
many of the planet and binary parameters are unknown.


title: A Formal Treatment of Sequential Ignorability

abstract:
  Taking a rigorous formal approach, we consider sequential decision problems
involving observable variables, unobservable variables, and action variables.
We can typically assume the property of extended stability, which allows
identification (by means of G-computation) of the consequence of a specified
treatment strategy if the unobserved variables are, in fact, observed - but not
generally otherwise. However, under certain additional special conditions we
can infer simple stability (or sequential ignorability), which supports
G-computation based on the observed variables alone. One such additional
condition is sequential randomization, where the unobserved variables
essentially behave as random noise in their effects on the actions. Another is
sequential irrelevance, where the unobserved variables do not influence future
observed variables. In the latter case, to deduce sequential ignorability in
full generality requires additional positivity conditions. We show here that
these positivity conditions are not required when all variables are discrete.


title:
Investigating the Detection of Adverse Drug Events in a UK General
  Practice Electronic Health-Care Database

abstract:
  Data-mining techniques have frequently been developed for Spontaneous
reporting databases. These techniques aim to find adverse drug events
accurately and efficiently. Spontaneous reporting databases are prone to
missing information, under reporting and incorrect entries. This often results
in a detection lag or prevents the detection of some adverse drug events. These
limitations do not occur in electronic health-care databases. In this paper,
existing methods developed for spontaneous reporting databases are implemented
on both a spontaneous reporting database and a general practice electronic
health-care database and compared. The results suggests that the application of
existing methods to the general practice database may help find signals that
have gone undetected when using the spontaneous reporting system database. In
addition the general practice database provides far more supplementary
information, that if incorporated in analysis could provide a wealth of
information for identifying adverse events more accurately.


title: Application of a clustering framework to UK domestic electricity data

abstract:
  This paper takes an approach to clustering domestic electricity load profiles
that has been successfully used with data from Portugal and applies it to UK
data. Clustering techniques are applied and it is found that the preferred
technique in the Portuguese work (a two stage process combining Self Organised
Maps and Kmeans) is not appropriate for the UK data. The work shows that up to
nine clusters of households can be identified with the differences in usage
profiles being visually striking. This demonstrates the appropriateness of
breaking the electricity usage patterns down to more detail than the two load
profiles currently published by the electricity industry. The paper details
initial results using data collected in Milton Keynes around 1990. Further work
is described and will concentrate on building accurate and meaningful clusters
of similar electricity users in order to better direct demand side management
initiatives to the most relevant target customers.


title: Two Fluid Shear-Free Composites

abstract:
  Shear-free composite fluids are constructed from two Letelier rotated
unaligned perfect fluids. The component fluid parameters necessary to construct
a shear-free composite are investigated. A metric in the Stephani-Barnes
solution family and a simple stationary metric are discussed.


title:
Finite-key analysis for measurement-device-independent quantum key
  distribution

abstract:
  Quantum key distribution promises unconditionally secure communications.
However, as practical devices tend to deviate from their specifications, the
security of some practical systems is no longer valid. In particular, an
adversary can exploit imperfect detectors to learn a large part of the secret
key, even though the security proof claims otherwise. Recently, a practical
approach---measurement-device-independent quantum key distribution---has been
proposed to solve this problem. However, so far its security has only been
fully proven under the assumption that the legitimate users of the system have
unlimited resources. Here we fill this gap and provide a rigorous security
proof against general attacks in the finite-key regime. This is obtained by
applying large deviation theory, specifically the Chernoff bound, to perform
parameter estimation. For the first time we demonstrate the feasibility of
long-distance implementations of measurement-device-independent quantum key
distribution within a reasonable time-frame of signal transmission.


title:
New companions in the stellar systems of DI Cha, Sz 22, CHXR 32, and Cha
  Halpha 5 in the Cha I star-forming region

abstract:
  The star-forming regions in Chamaeleon (Cha) are among the nearest (distance
~165 pc) and youngest (age ~2 Myrs) conglomerates of recently formed stars and
among the ideal targets for studies of star formation. We search for new,
hitherto unknown binary or multiple-star components and investigate their
membership in Cha and their gravitationally bound nature. We used the NACO
instrument at the VLT UT 4/YEPUN of the Paranal Observatory, at 2 or 3
different epochs, in order to obtain relative and absolute astrometric
measurements, as well as differential photometry in the J, H, and Ks band. On
the basis of known proper motions and these observations, we analysed the
astrometric results in proper motion diagrams to eliminate possible
(non-moving) background stars and establish co-moving binaries and multiples.
DI Cha turns out to be a quadruple system with a hierachical structure,
consisting of two binaries: a G2/M6 pair and a co-moving pair of two M5.5
dwarfs. For both pairs we detected orbital motion (P~130 and ~65 years),
although in opposite directions. Sz 22 is a binary whose main component is
embedded in a circumstellar disc or reflection nebula, accompanied by a
co-moving M4.5 dwarf. CHXR 32 is a triple system, consisting of a single G5
star, weakened by an edge-on disc and a co-moving pair of M1/M3.5 dwarfs whose
components show significant variations in their angular separation. Finally,
Cha Halpha 5 is a binary consisting of two unresolved M6.5 dwarfs whose strong
variations in position angle at its projected separation of only 8 AU imply an
orbital period of ~46 years. DI Cha D and Cha Halpha 5 A&B are right at the
stellar mass limit and could possibly be brown dwarfs. In spite of various
previously published studies of the star-forming regions in Cha we found four
hitherto unknown components in young low-mass binaries and multiple systems.
(abridged)


title:
Discord in relation to resource states for measurement-based quantum
  computation

abstract:
  We consider the issue of what should count as a resource for
measurement-based quantum computation (MBQC). While a state that supports
universal quantum computation clearly should be considered a resource,
universality should not be necessary given the existence of interesting, but
less computationally-powerful, classes of MBQCs. Here, we propose minimal
criteria for a state to be considered a resource state for MBQC. Using these
criteria, we explain why discord-free states cannot be resources for MBQC,
contrary to recent claims [Hoban et al., arXiv:1304.2667v1]. Independently of
our criteria, we also show that the arguments of Hoban et al., if correct,
would imply that Shor's algorithm (for example) can be implemented by measuring
discord-free states.


title:
X-ray Observations of the Supernova Remnant CTB 87 (G74.9+1.2): An
  Evolved Pulsar Wind Nebula

abstract:
  Pulsar wind nebulae (PWNe) studies with the Chandra X-ray Observatory have
opened a new window to address the physics of pulsar winds, zoom on their
interaction with their hosting supernova remnant (SNR) and interstellar medium,
and identify their powering engines. We here present a new 70 ks, plus an
archived 18 ks, Chandra ACIS observation of the SNR CTB 87 (G74.9+1.2),
classified as a PWN with unusual radio properties and poorly studied in X-rays.
We find that the peak of the X-ray emission is clearly offset from the peak of
the radio emission by ~100" and located at the southeastern edge of the radio
nebula. We detect a point source - the putative pulsar - at the peak of the
X-ray emission and study its spectrum separately from the PWN. This new point
source, CXOU J201609.2+371110, is surrounded by a compact nebula displaying a
torus-like structure and possibly a jet. A more extended diffuse nebula is
offset from the radio nebula, extending from the point source to the northwest
for ~250" The spectra of the point source, compact nebula and extended diffuse
nebula are all well described by a power law model with a photon index of 1.1
(0.7-1.6), 1.2 (0.9-1.4) and 1.7 (1.5-1.8), respectively, for a column density
N_H = 1.38 (1.21-1.57) x 10^22 cm^-2 (90% confidence). The total X-ray
luminosity of the source is ~1.6 x 10^34 erg s^-1 at an assumed distance of 6.1
kpc, with ~2% and 6% contribution from the point source and compact nebula,
respectively. The observed properties suggest that CTB 87 is an evolved (~5-28
kyr) PWN, with the extended radio emission likely a `relic' PWN, as in Vela-X
and G327.1-1.1. To date, however, there is no evidence for thermal X-ray
emission from this SNR, and the SNR shell is still missing, suggesting
expansion into a low-density medium (n_0 < 0.2 cm^-3, assuming D = 6.1 kpc),
likely caused by a stellar wind bubble blown by the progenitor star.


title: The B-model connection and mirror symmetry for Grassmannians

abstract:
  We consider the Grassmannian X of (n-k)-dimensional subspaces of an
n-dimensional complex vector space. We describe a `mirror dual' Landau-Ginzburg
model for X consisting of the complement of a particular anti-canonical divisor
in a Langlands dual Grassmannian together with a superpotential expressed
succinctly in terms of Pl\"ucker coordinates. First of all, we show this
Landau-Ginzburg model to be isomorphic to the one proposed by the second
author. Secondly we show it to be a partial compactification of the
Landau-Ginzburg model defined in the 1990s by Eguchi, Hori, and Xiong. Finally
we construct inside the Gauss-Manin system associated to the superpotential a
free submodule which recovers the trivial vector bundle with small Dubrovin
connection defined out of Gromov-Witten invariants of X. We also prove a
T-equivariant version of this isomorphism of connections. Our results imply in
the case of Grassmannians an integral formula for a solution to the quantum
cohomology D-module of a homogeneous space, which was conjectured by the second
author. They also imply a series expansion of the top term in Givental's
J-function, which was conjectured in a 1998 paper by Batyrev, Ciocan-Fontaine,
Kim and van Straten.


title:
On the alleged coherence between the global temperature and the sun's
  movement

abstract:
  It has recently been claimed that there is significant coherence between the
spectral peaks of the global temperature series over the last 160 years and
those of the speed of the solar center of mass at periods of 10-10.5, 20-21, 30
and 60-62 years. Here it is shown that these claims are based on a comparison
between spectral peaks in spectral estimates that assume that the global
temperature data contains time-invariant spectral lines. However,
time-frequency analysis using both windowed periodograms and the maximum
entropy method shows that this is not the case. An estimate of the magnitude
squared coherence shows instead that under certain conditions only coherence at
a period of 15-17 years can be found in the data. As this result builds on a
low number of independent averages and also is unwarranted from any physical
model it is doubtful whether it is significant.


title: Dielectric screening and plasmons in AA-stacked bilayer graphene

abstract:
  The screening properties and collective excitations (plasmons) in AA-stacked
bilayer graphene are studied within the random phase approximation (RPA).
Whereas long lived plasmons in single layer graphene and in AB-stacked bilayer
graphene can exist only in doped samples, we find that coherent plasmons can
disperse in AA-stacked bilayer graphene {\it even in the absence of doping}.
Moreover, we show that the characteristic low energy dispersion relation is
unaffected by changes in the number of carriers, unless the chemical potential
of the doped sample exceeds the inter-layer hopping energy. We further consider
the effect of an external electric field applied perpendicular to the layers,
and show how the dispersion of the modes can be tuned by the application of a
gate voltage.


title: Suggest an Aspect-Oriented Design Approach for UML Communication Diagram

abstract:
  More and more works are done on the design of the Unified Modeling Language
(UML) which is designed to help us for modeling effective object oriented
software, Existing Object-Oriented design methods are not mature enough to
capture non-functional requirement such as concurrency, fault tolerance,
distribution and persistence of a software approach. Our approach proposed to
use aspect-oriented software development (AOSD) mechanisms to solve the issues
for interactions of the communication diagram in UML that support only the
Object-Oriented mechanisms,thus AOSD allow to design programs that are out of
reach of strict Object-Orientation and could possibly improve the structures
and implementations.


title:
The Daya Bay Antineutrino Detector Filling System and Liquid Mass
  Measurement

abstract:
  The Daya Bay Reactor Neutrino Experiment has measured the neutrino mixing
angle \theta_{13} to world-leading precision. The experiment uses eight
antineutrino detectors filled with 20-tons of gadolinium-doped liquid
scintillator to detect antineutrinos emitted from the Daya Bay nuclear power
plant through the inverse beta decay reaction. The precision measurement of
sin^{2}2\theta_{13} relies on the relative antineutrino interaction rates
between detectors at near (400 m) and far (roughly 1.8 km) distances from the
nuclear reactors. The measured interaction rate in each detector is directly
proportional to the number of protons in the liquid scintillator target. A
precision detector filling system was developed to simultaneously fill the
three liquid zones of the antineutrino detectors and measure the relative
target mass between detectors to <0.02%. This paper describes the design,
operation, and performance of the system and the resulting precision
measurement of the detectors' target liquid masses.


title: Countable Contraction Maps in Metric Spaces: Invariant Sets and Measures

abstract:
  We consider a complete metric space $(X,d)$ and a countable number of
contractive mappings on $X$, $\mathcal{F}=\{F_i:i\in\mathbb N\}$. We show the
existence of a {\em smallest} invariant set (with respect to inclusion) for
$\mathcal{F}$. If the maps $F_i$ are of the form $F_i(\x) = r_i \boldmath{x} +
b_i$ on $X=\mathbb{R}^d$, we can prove a converse of the classic result on
contraction maps. Precisely, we can show that for that case, there exists a
{\em unique} bounded invariant set if and only if $r = \sup_i r_i$ is strictly
smaller than 1.
  Further, if $\rho = \{\rho_k\}_{k\in \mathbb N}$ is a probability sequence,
we show that if there exists an invariant measure for the system
$(\mathcal{F},\rho)$, then it's support must be precisely this smallest
invariant set. If in addition there exists any {\em bounded} invariant set,
this invariant measure is unique - even though there may be more than one
invariant set.


title: Titanium dioxide (TiO2) Nanoparticles XRD Analyses: An Insight

abstract:
  This work reports aspect related to nano-sized particles of tetragonal
anatase phase Titania. This approach is simple, faster, Eco-friendly, cost
effective and suitable for large scale production. X-Ray Diffraction studies
analyze particles size. It is found to be 74 nm and specific surface area is
19.16m2g-1. Morphology index (MI) derived from FWHM of XRD data explains the
interrelationship of particle size and specific surface area. It is observed
that MI has direct relationship with particle size and an inverse relationship
with specific surface area. This work throws some light on and helps in the
production line of Titania nano-particles.


title: Multijunction solar cells efficiency simulation

abstract:
  The radiative recombination, Shokley-Read recombination, frontal-surface and
rear-surface recombination and the recombination at the heterojunction
boundaries and the recombination in the space charge region are considered in
the calculation of the multijunction solar cell (MSC) efficiency. The
calculation is performed by a self-consistent solution of the equations for the
photocurrent and photovoltage, as well as the heat balance equation. A cooling
of MSC with the increase of the number of cells n and the improvement in the
heat dissipation is regarded. It was found that, as the number of cells n is
increased, narrowing of spectral range for each cell causes additional
reduction of current. A substantial increase in the MSC efficiency can be
achieved by improving the heat extraction using radiators and increasing
emissivity. A comparison is made between the calculated and experimental
efficiency values. A rather good agreement was found. A comparison between this
calculation and other formalisms is given.


title:
Energy Dependence of the Transverse Momentum Distributions of Charged
  Particles in pp Collisions Measured by ALICE

abstract:
  Differential cross sections of charged particles in inelastic pp collisions
as a function of $p_{\rm T}$ have been measured at $\sqrt{s}=$ 0.9, 2.76 and 7
TeV at the LHC. The $p_{\rm T}$ spectra are compared to NLO-pQCD calculations.
Though the differential cross section for an individual $\sqrt{s}$ cannot be
described by NLO-pQCD, the relative increase of cross section with $\sqrt{s}$
is in agreement with NLO-pQCD. Based on these measurements and observations,
procedures are discussed to construct pp reference spectra at $\sqrt{s} =$ 2.76
and 5.02 TeV up to $p_{\rm T}$ = 50 GeV/$c$ as required for the calculation of
the nuclear modification factor in nucleus-nucleus and proton-nucleus
collisions.


title:
Multiplicity dependence of the average transverse momentum in pp, p-Pb,
  and Pb-Pb collisions at the LHC

abstract:
  The average transverse momentum $\langle p_{\rm T}\rangle$ versus the
charged-particle multiplicity $N_{\rm ch}$ was measured in p-Pb collisions at a
collision energy per nucleon-nucleon pair $\sqrt{s_{\rm NN}}=5.02$ TeV and in
pp collisions at collision energies of $\sqrt{s}=0.9$, 2.76, and 7 TeV in the
kinematic range $0.15<p_{\rm T}<10.0$ GeV/$c$ and $|\eta|<0.3$ with the ALICE
apparatus at the LHC. These data are compared to results in Pb-Pb collisions at
$\sqrt{s_{\rm NN}}=2.76$ TeV at similar charged-particle multiplicities. In pp
and p-Pb collisions, a strong increase of $\langle p_{\rm T}\rangle$ with
$N_{\rm ch}$ is observed, which is much stronger than that measured in Pb-Pb
collisions. For pp collisions, this could be attributed, within a model of
hadronizing strings, to multiple-parton interactions and to a final-state color
reconnection mechanism. The data in p-Pb and Pb-Pb collisions cannot be
described by an incoherent superposition of nucleon-nucleon collisions and pose
a challenge to most of the event generators.


title:
Riemann's hypothesis and some infinite set of microscopic universes of
  the Einstein's type in the early period of the evolution of the Universe

abstract:
  We obtain in this paper, as a consequence of the Riemann hypothesis, certain
class of topological deformations of the graph of the function $|\zf|$. These
are used to construct an infinite set of microscopic universes (on the Planck's
scale) of the Einstein type. Dedicated to the 90th anniversary of the A.S.
Edington's book \emph{The mathematical theory of relativity}.


title: Scalar-pseudoscalar interactions in neutrino-electron scattering

abstract:
  Many extensions to the Standard Model imply the existence of new charged
scalar Higgs bosons. We study the contribution of a general scalar or
pseudoscalar coupling for the neutrino-electron scattering. We take a
phenomenological approach in order to obtain model independent limits to the
couplings that arise in this picture. We illustrate the reach of the
constraints by studying the particular case of the type III two Higgs doublet
model, where we have found new constraints to some elements of the Yukawa
couplings mixing matrix ($|Y_{ee}| \leq 1 \times 10^{-1}$ and $|Y_{e\mu}| \leq
7\times10^{-2}$ at 90% CL).


title: A construction principle for ADM-type theories in maximal slicing gauge

abstract:
  The differing concepts of time in general relativity and quantum mechanics
are widely accused as the main culprits in our persistent failure in finding a
complete theory of quantum gravity. Here we address this issue by constructing
ADM-type theories \emph{in a particular time gauge} directly from first
principles. The principles are expressed as conditions on phase space
constraints: we search for two sets of spatially covariant constraints, which
generate symmetries (are first class) and gauge-fix each other leaving two
propagating degrees of freedom.
  One of the sets is the Weyl generator tr$(\pi)$, and the other is a
one-parameter family containing the ADM scalar constraint $\lambda R-
\beta(\pi^{ab}\pi_{ab}+(\mbox{tr}(\pi))^2/2))$. The two sets of constraints can
be seen as defining ADM-type theories with a maximal slicing gauge-fixing. This
work provides an independent, first principles derivation of ADM gravity.
  The principles above are motivated by a heuristic argument relying in the
relation between symmetry doubling and exact renormalization arguments for
quantum gravity, aside from compatibility with the spatial diffeomorphisms. As
a by-product, these results address one of the most popular criticisms of Shape
Dynamics: its construction starts off from the ADM Hamiltonian formulation.
  The present work severs this dependence: the set of constraints yield reduced
phase space theories that can be naturally represented by either Shape Dynamics
or ADM. More precisely, the resulting theories can be naturally "unfixed" to
encompass either spatial Weyl invariance (the symmetry of Shape Dynamics) or
refoliation symmetry (ADM).


title:
A Pedagogical Study of the Grand Unification Theorem with Realization of
  Some Standard Equations

abstract:
  The God Almighty Grand Unification Theory proposed by Oyibo to unify all
known forces in nature and other possibly unknown force fields has remained
controversial not just because of its ambitious claims but also because of its
unconventional mathematical approach. He has adopted the mathematical approach
from his experience at solving the Navier Stokes equations in fluid mechanics
using invariance of an arbitrary function under a group of conformal
transformations. However, this esoteric approach resulted in a sound
mathematical formulation for the modelling philosophy of his theorem which is
that since the fundamental characteristic of the universe is motion and motion
can only be provided by force, then the universe could be viewed as a large
force field. He then represented the conservation of this large force field at
a given space time point in the universe by a set of generic equations from
which he obtained his generic solutions whose specific applications depend on
the initial/boundary conditions and other physical constraint conditions. An
important achievement of the theorem methodology is that modelling with it is
reduced to algebraic operations rather than differential equations for the most
parts in previous methodologies. With this understanding from pedagogically
studying the modelling philosophy and mathematics of the theorem, we have been
able to recover from it simple standard equations such as in the Fermat
principle for geometric optics. This is encouraging and therefore supports the
possibility to recover more results and also to provide new ones, thereby
supporting the theorem as a potential candidate for a grand unification theory.


title: DBI analog of a decaying vacuum cosmology

abstract:
  In this work I discuss the dynamical and thermodynamical equivalence between
a general k-essence scalar field cosmology and an arbitrary cosmological model
with a decaying vacuum, thus generalizing the approach proposed by Maia and
Lima [Phys. Rev. D {\bf 65}, 083513 (2002)]. The formalism obtained is quite
general and holds for any non-canonical scalar field model. As a special case I
derive a Dirac-Born-Infeld (DBI) model with an exponential potential and
constant speed of sound, and show that it is equivalent to a cosmological model
with decay law $\Lambda(H) = 3\beta H^2$.


title: Stability of Thin-Shell Wormholes in Nonlinear Electrodynamics

abstract:
  In this paper, we construct thin-shell wormholes by applying the cut and
paste procedure to a regular charged black hole in nonlinear electrodynamics
field. We discuss different physical aspects of wormholes such as, the possible
equation of state to matter shell, attractive or repulsive nature of wormhole
and total amount of exotic matter required. The thin-shell equation of motion
with and without cosmological constant is also investigated under linearized
perturbation. Finally, we explore the stability regions interpreted by the
parameter $\beta$ (speed of sound) and conclude that there are realistic
stability regions for some fixed values of parameters.


title:
Mixed-Timescale Precoding and Cache Control in Cached MIMO Interference
  Network

abstract:
  Consider media streaming in MIMO interference networks whereby multiple base
stations (BS) simultaneously deliver media to their associated users using
fixed data rates. The performance is fundamentally limited by the cross-link
interference. We propose a cache-induced opportunistic cooperative MIMO (CoMP)
for interference mitigation. By caching a portion of the media files, the BSs
opportunistically employ CoMP to transform the cross-link interference into
spatial multiplexing gain. We study a mixed-timescale optimization of MIMO
precoding and cache control to minimize the transmit power under the rate
constraint. The cache control is to create more CoMP opportunities and is
adaptive to the long-term popularity of the media files. The precoding is to
guarantee the rate requirement and is adaptive to the channel state information
and cache state at the BSs. The joint stochastic optimization problem is
decomposed into a short-term precoding and a long-term cache control problem.
We propose a precoding algorithm which converges to a stationary point of the
short-term problem. Based on this, we exploit the hidden convexity of the
long-term problem and propose a low complexity and robust solution using
stochastic subgradient. The solution has significant gains over various
baselines and does not require explicit knowledge of the media popularity.


title:
A path integral formalism for non-equilibrium Hamiltonian statistical
  systems

abstract:
  A path integral formalism for non-equilibrium systems is proposed based on a
manifold of quasi-equilibrium densities. A generalized Boltzmann principle is
used to weight manifold paths with the exponential of minus the information
discrepancy of a particular manifold path with respect to full Liouvillean
evolution. The likelihood of a manifold member at a particular time is termed a
consistency distribution and is analogous to a quantum wavefunction. The
Lagrangian here is of modified generalized Onsager-Machlup form. For large
times and long slow timescales the thermodynamics is of Oettinger form. The
proposed path integral has connections with those occuring in the quantum
theory of a particle in an external electromagnetic field. It is however
entirely of a Wiener form and so practical to compute. Finally it is shown that
providing certain reasonable conditions are met then there exists a unique
steady-state consistency distribution.


title: Impact of Rotation on the Structure and Composition of Neutron Stars

abstract:
  Depending on mass and rotational frequency, gravity compresses the matter in
the core regions of neutron stars to densities that are several times higher
than the density of ordinary atomic nuclei. At such huge densities atoms
themselves collapse, and atomic nuclei are squeezed so tightly together that
new particle states may appear and novel states of matter, foremost quark
matter, may be created. This feature makes neutron stars superb astrophysical
laboratories for a wide range of physical studies. And with observational data
accumulating rapidly from both orbiting and ground based observatories spanning
the spectrum from X-rays to radio wavelengths, there has never been a more
exiting time than today to study neutron stars. The Hubble Space Telescope and
X-ray satellites such as Chandra and XMM-Newton in particular have proven
especially valuable. New astrophysical instruments such as the Five hundred
meter Aperture Spherical Telescope (FAST), the square kilometer Array (skA),
Fermi Gamma-ray Space Telescope (formerly GLAST), and possibly the
International X-ray Observatory (now Advanced Telescope for High ENergy
Astrophysics, ATHENA) promise the discovery of tens of thousands of new
non-rotating and rotating neutron stars. The latter are referred to as pulsars.
This paper provides a short overview of the impact of rotation on the structure
and composition of neutron stars. Observational properties, which may help to
shed light on the core composition of neutron stars--and, hence, the properties
of ultra-dense matter--are discussed.


title:
Quantum Tunneling and Information Entropy in a Double Square Well
  Potential: Ammonia Molecule

abstract:
  Quantum tunneling is the quantum-mechanical effect where a particle tunnels
through a classically forbidden region. Double Square Well Potential (DSWP) is
a system where this phenomenon is feasible. Numerous phenomena can be
illustrated by considering motion in a pair of wells that are separated by a
barrier of finite height and width. The energy level splitting, resulting from
barrier penetration, is the reason of the so-called inversion spectrum, which
is an example of quantum tunneling. Out of several molecules ($NH_3$, $PH_3$,
$AsH_3$, $NH_2CN$) where this inversion phenomenon occurs, ammonia molecule
$NH_3$ provides a nice physical realization of a vibrational system with a
DSWP. The main goal of the present work is to examine the implications of
quantum tunneling on information entropy measures (Shannon's and Fisher's) and
statistical complexity.


title:
Local and Nonlocal Advected Invariants and Helicities in
  Magnetohydrodynamics and Gas Dynamics I: Lie Dragging Approach

abstract:
  In this paper we discuss conservation laws in ideal magnetohydrodynamics
(MHD) and gas dynamics associated with advected invariants. The invariants in
some cases, can be related to fluid relabelling symmetries associated with the
Lagrangian map. There are different classes of invariants that are advected or
Lie dragged with the flow. Simple examples are the advection of the entropy S
(a 0-form), and the conservation of magnetic flux (an invariant 2-form advected
with the flow). The magnetic flux conservation law is equivalent to Faraday's
equation. We discuss the gauge condition required for the magnetic helicity to
be advected with the flow. The conditions for the cross helicity to be an
invariant are discussed. We discuss the different variants of helicity in fluid
dynamics and in MHD, including: fluid helicity, cross helicity and magnetic
helicity. The fluid helicity conservation law and the cross helcity
conservation law in MHD are derived for the case of a barotropic gas. If the
magnetic field lies in the constant entropy surface, then the gas pressure can
depend on both the entropy and the density. In these cases the conservation
laws are local conservation laws. We obtain nonlocal conservation laws for
fluid helicity and cross helicity for non-barotropic fluids using the Clebsch
variable formulation of gas dynamics and MHD. Ertel's theorem and potential
vorticity, the Hollman invariant, and the Godbillon Vey invariant for special
flows for which the magnetic helicity is zero are also discussed.


title: Global diffusion on a tight three-sphere

abstract:
  We consider an integrable Hamiltonian system weakly coupled with a
pendulum-type system. For each energy level within some range, the uncoupled
system is assumed to possess a normally hyperbolic invariant manifold
diffeomorphic to a three-sphere, which bounds a strictly convex domain, and
whose stable and unstable invariant manifolds coincide. The Hamiltonian flow on
the three-sphere is equivalent to the Reeb flow for the induced contact form.
The strict convexity condition implies that the contact structure on the
three-sphere is tight. When a small, generic coupling is added to the system,
the normally hyperbolic invariant manifold is preserved as a three-sphere, and
the stable and unstable manifolds split, yielding transverse intersections. We
show that there exist trajectories that follow any prescribed collection of
invariant tori and Aubry-Mather sets within some global section of the flow
restricted to the three-sphere. In this sense, we say that the perturbed system
exhibits global diffusion on the tight three-sphere.


title:
Some Generalizations in Supersymmetric Quantum Mechanics and the
  Supersymmetric $\varepsilon$-System Revisited

abstract:
  We discuss two distinct aspects in supersymmetric quantum mechanics. First,
we introduce a new class of operators A and $\bar{A}$ in terms of
anticommutators between the momentum operator and N+1 arbitrary
superpotentials. We show that these operators reduce to the conventional ones
which are the starting point in standard supersymmetric quantum mechanics. In
this context, we argue furthermore that supersymmetry does not only connect
Schr\"odinger-like operators, but also a more general class of differential
operators. Second, we revisit the supersymmetric $\varepsilon$-system recently
introduced in the literature by exploiting its intrinsic supersymmetry.
Specifically, combining the Hamilton hierarchy method and the
$\delta$-expansion method, we determine an energy for the first excited state
of the bosonic Hamiltonian close to that calculated in earlier works.


title: Resonant electromagnetic scattering in anisotropic layered media

abstract:
  The resonant excitation of an electromagnetic guided mode of a slab structure
by exterior radiation results in anomalous scattering behavior, including sharp
energy-transmission anomalies and field amplification around the frequency of
the slab mode. In the case of a periodically layered ambient medium, anisotropy
serves to couple the slab mode to radiation. Exact expressions for scattering
phenomena are proved by analyzing a pole of the full scattering matrix as it
moves off the real frequency axis into the lower half complex plane under a
detuning of the wavevector parallel to the slab. The real pole is the frequency
of a perfect (infinite Q) guided mode, which becomes lossy as the frequency
gains an imaginary part. This work extends results of Shipman and Venakides to
evanescent source fields and two-dimensional parallel wavevector and
demonstrates by example how the latter allows one to control independently the
width and central frequency of a resonance by varying the angle of incidence of
the source field. The analysis relies on two nondegeneracy conditions of the
complex dispersion relation for slab modes (relating poles of the scattering
matrix to wavevector), which were assumed in previous works and are proved in
this work for layered media. One of them asserts that the dispersion relation
near the wavevector and frequency of a perfect guided mode is the zero set of a
simple eigenvalue, and the other relates the frequency derivative of the
eigenvalue to the total energy of the mode, thereby implying that this
derivative is nonzero.

categories: cond-mat.mtrl-sci math-ph math.MP physics.class-ph


title:
A note on the nonuniqueness of the massive Fierz-Pauli theory and
  spectator fields

abstract:
  It is possible to show that there are three independent families of models
describing a massive spin-2 particle via a rank-2 tensor. One of them contains
the massive Fierz-Pauli model, the only case described by a symmetric tensor.
The three families have different local symmetries in the massless limit and
can not be interconnected by any local field redefinition. We show here
however, that they can be related with the help of a decoupled and non dynamic
(spectator) field. The spectator field may be either an antisymmetric tensor
$B_{\mu\nu}=-B_{\nu\mu}$, a vector $A_{\mu}$ or a scalar field $\varphi$,
corresponding to each of the three families. The addition of the extra field
allows us to formulate master actions which interpolate between the symmetric
Fierz-Pauli theory and the other models. We argue that massive gravity models
based on the Fierz-Pauli theory are not expected to be equivalent to possible
local self-interacting theories built up on the top of the two new families of
massive spin-2 models.
  The approach used here may be useful to investigate dual (nonsymmetric)
formulations of higher spin particles.


title: Quarkonium Production at LHCb

abstract:
  I will review a selection of LHCb results on the production of heavy
quarkonium states in pp collisions, including the recent results on J/psi and
Y(nS) (n=1,2,3) production at sqrt(s)=8TeV, as well as preliminary results on
J/psi production in proton-lead collisions at sqrt(s_NN)=5TeV.


title: On the Coherence of WMAP and Planck Temperature Maps

abstract:
  The recent data release of ESA's Planck mission together with earlier WMAP
releases provide the first opportunity to compare high resolution full sky
Cosmic Microwave Background temperature anisotropy maps. To quantify the
coherence of these maps beyond the power spectrum we introduce Generalized
Phases, unit vectors in the (2l+1) dimensional representation spaces. For a
Gaussian distribution, Generalized Phases are random and if there is
non-Gaussianity, they represent most of the non-Gaussian information. The
alignment of these unit vectors from two maps can be characterized by their
angle, 0 deg expected for full coherence, and 90 deg for random vectors. We
analyze maps from both missions with the same mask and Nside=512 resolution,
and compare both power spectra and Generalized Phases. We find excellent
agreement of the Generalize Phases of Planck Smica map with that of the WMAP
Q,V,W maps, rejecting the null hypothesis of no correlations at 5 sigma for l's
l<700, l<900 and l<1100, respectively, except perhaps for l<10. Using
foreground reduced maps for WMAP increases the phase coherence. The observed
coherence angles can be explained with a simple assumption of Gaussianity and a
WMAP noise model neglecting Planck noise, except for low-intermediate l's there
is a slight, but significant off-set, depending on WMAP band. On the same
scales WMAP power spectrum is about 2.6% higher at a very high significance,
while at higher l's there appears to be no significant bias. Using our
theoretical tools, we predict the phase alignment of Planck with a hypothetical
perfect noiseless CMB experiment, finding decoherence at l > 2900; below this
value Planck can be used most efficiently to constrain non-Gaussianity.


title: Phenomenology of heavy vector-like leptons

abstract:
  We study the impact that a heavy generation of vector-like leptons can have
on the value of the electric dipole moment of the electron, and the rates for
the flavor violating processes mu --> e gamma and mu --> 3e. The smallness of
the charged lepton masses suggests that at least some of the Yukawa coupling
constants of the vector-like leptons to the ordinary leptons or amongst
themselves are small, but even with such small couplings experiments trying to
detect these quantities are sensitive to extra generation lepton masses up to
about 100 TeV.


title: Short time-scale periodicity in OJ 287

abstract:
  We have studied short-term variations of the blazar OJ 287, suspected to host
a supermassive black hole binary. In this study, we use a two-season optical
R-band dataset from 2004--2006 which consists of 3991 data points from the OJ
287 observation campaign. It has sections of dense time coverage, and is
largely independent from previously published data. We find that this data
confirms the existence of a ~50 day periodic component, presumably related to
the half-period of the innermost stable circular orbit (ISCO) of the primary
black hole. In addition we find several pseudo-periodic components in the 1 to
7 day range, most prominently at 3.5 days, which are likely Lorentz contracted
jet re-emission of the 50 day component. The typical 50 day cycle exhibits a
slow rise of brightness and a rapid dimming before the start of the new cycle.
We explain this as being due to a spiral wave in the accretion disc which feeds
the central black hole in this manner.


title:
Hearing the Shape of the Ising Model with a Programmable
  Superconducting-Flux Annealer

abstract:
  Two objects can be distinguished if they have different measurable
properties. Thus, distinguishability depends on the Physics of the objects. In
considering graphs, we revisit the Ising model as a framework to define
physically meaningful spectral invariants. In this context, we introduce a
family of refinements of the classical spectrum and consider the quantum
partition function. We demonstrate that the energy spectrum of the quantum
Ising Hamiltonian is a stronger invariant than the classical one without
refinements. For the purpose of implementing the related physical systems, we
perform experiments on a programmable annealer with superconducting flux
technology. Departing from the paradigm of adiabatic computation, we take
advantage of a noisy evolution of the device to generate statistics of low
energy states. The graphs considered in the experiments have the same classical
partition functions, but different quantum spectra. The data obtained from the
annealer distinguish non-isomorphic graphs via information contained in the
classical refinements of the functions but not via the differences in the
quantum spectra.


title: The Globular Cluster NGC 6402 (M14). I. A New BV Color-Magnitude Diagram

abstract:
  We present BV photometry of the Galactic globular cluster NGC 6402 (M14),
based on 65 V frames and 67 B frames, reaching two magnitudes below the
turn-off level. This represents, to the best of our knowledge, the deepest
color-magnitude diagram (CMD) of NGC 6402 available in the literature.
Statistical decontamination of field stars as well as differential reddening
corrections are performed in order to derive a precise ridgeline and derive
physical parameters of the cluster therefrom.
  We discuss previous attempts to derive a reddening value for the cluster, and
argue in favor of a value E(B-V) = 0.57 +/- 0.02, which is significantly higher
than indicated by either the Burstein & Heiles or Schlegel et al. (corrected
according to Bonifacio et al.) interstellar dust maps. Differential reddening
across the face of the cluster, which we find to be present at the level of
Delta E(B-V) ~ 0.17 mag, is taken into account in our analysis. We measure
several metallicity indicators based on the position of the red giant branch
(RGB) in the cluster CMD. These give a metallicity of [Fe/H] = -1.38 +/- 0.07
in the Zinn & West scale and [Fe/H] = -1.28 +/- 0.08 in the new Carretta et al.
(UVES) scale. We also provide measurements of other important photometric
parameters for this cluster, including the position of the RGB luminosity
function "bump" and the horizontal branch (HB) morphology. We compare the NGC
6402 ridgeline with the one for NGC 5904 (M5) derived by Sandquist et al., and
find evidence that NGC 6402 and M5 have approximately the same age, to within
the uncertainties -- although the possibility that M14 may be slighlty older
cannot be ruled out.


title: Stacks of ramified Galois covers

abstract:
  Given a finite, flat and finitely presented group scheme $G$ over some base
$S$, we introduce the notion of ramified $G$-covers and study the moduli stack
$G$-Cov they form. The thesis is divided in three parts. The first one concerns
the case when $G$ is a diagonalizable group scheme and it essentially coincides
with arxiv:1106.2347. In the second part I deal with the general case. Assuming
that the base S is affine and given an $S$-scheme $T$, I interpret $G$-covers
of $T$ as particolar (lax) monoidal functors from the category of finite,
$G$-equivariant locally free sheaves over $S$ to the category of finite locally
free sheaves over $T$, extending the classical Tannakian correspondence between
$G$-torsors and strong monoidal functors as above. Using this point of view, I
prove that $G$-Cov is always reducible if $G$ is a non-abelian linearly
reductive group. When $G$ is constant and tame I also give a criterion to
detect when a $G$-cover of a regular in codimension one, integral scheme has
regular in codimension one total space in terms of the functor associated with
the cover. In the last part I focus on the case $G=S_3$, prove that $S_3$-Cov
has exactly two irreducible components and describe the principal one. I also
describe particular open loci of $S_3$-Cov, that is particular families of
$S_3$-covers, classify $S_3$-covers of regular schemes whose total space is
regular and compute the invariants of $S_3$-covers of smooth surfaces.


title:
Calibration of the 6302/6301 Stokes V line ratio in terms of the
  5250/5247 ratio

abstract:
  Four decades ago the Stokes V line ratio in the Fe I 5247.06 and 5250.22
{\AA} lines was introduced as a powerful means of exploring the intrinsic field
strengths at sub-pixel scales, which led to the discovery that most of the
photospheric flux is in intermittent kG form. The "green" 5247-5250 line pair
is unique because it allows the magnetic-field effects to be isolated from the
thermodynamic effects. No other line pair with this property has since been
identified. In recent years much of the magnetic-field diagnostics has been
based on the "red" Fe I 6301.5 and 6302.5 {\AA} line pair, since it was chosen
in the design of the Hinode space observatory. Although thermodynamic effects
severely contaminate the magnetic-field signatures for this line ratio, it is
still possible to use it to extract information on intrinsic magnetic fields,
but only after it has been "renormalized", since otherwise it produces
fictitious, superstrong fields everywhere. In the present work we explore the
joint behavior of these two line ratios to determine how the "contaminated" red
line ratio can be translated into the corresponding green line ratio, which
then allows for a direct interpretation in terms of intrinsic magnetic fields.
Our observations are mainly based on recordings with the ZIMPOL-3
spectro-polarimeter at IRSOL in Locarno, Switzerland, complemented by data from
the STOP telescope at the Sayan solar observatory (Irkutsk, Russia). The IRSOL
observations are unique by allowing both the green and red line pairs to be
recorded simultaneously on the same CCD sensor. We show how the line ratios
depend on both the measured flux densities and on the heliocentric distance
(the \mu\ value on the solar disk), and finally derive the calibration function
that enables the red line ratio to be translated to the green ratio for each
\mu\ value.


title:
Manifestation of charged and strained graphene layers in the Raman
  response of graphite intercalation compounds

abstract:
  We present detailed multi frequency resonant Raman measurements of potassium
graphite intercalation compounds (GICs). From a well controlled and consecutive
in-situ intercalation and high temperature de-intercalation approach the
response of each stage up to stage VI is identified. The positions of the G and
2D lines as a function of staging depend on the charge transfer from K to the
graphite layers and on the lattice expansion. Ab-initio calculations of the
density and the electronic band-structure demonstrate that most (but not all)
of the transferred charge remains on the graphene sheets adjacent to the
intercalant layers. This leads to an electronic decoupling of these "outer"
layers from the ones sandwiched between carbon layers and consequently to a
decoupling of the corresponding Raman spectra. Thus higher stage GICs offer the
possibility to measure the vibrations of single, double, and multi-layer
graphene under conditions of biaxial strain. This strain can additionally be
correlated to the in-plane lattice constants of GICs determined by x-ray
diffraction. The outcome of this study demonstrates that Raman spectroscopy is
a very powerful tool to identify local internal strain in pristine and weakly
charged single and few-layer graphene and their composites, yielding even
absolute lattice constants.


title: A molecular method applied to a non-local PDE in stratified Lie groups

abstract:
  In this article we study a transport-diffusion equation in the framework of
the stratified Lie groups. For this equation we will study the existence of the
solutions, a maximum principle, a positivity principle and H\"older regularity.


title: Graphs, groups and self-similarity

abstract:
  We study a family of C*-algebras generalizing both Katsura algebras and
certain algebras introduced by Nekrashevych in terms of self-similar groups.


title:
The Model of the Mechanism of the VLF/LF, ULF Emission Influence on the
  Local Meteorological Processes During the Earthquake Preparation Period

abstract:
  Atmospheric electric field inversion gives theoretical base for local weather
management.


title: Simulating GHZ Correlations Relaxing Physical Constraints

abstract:
  Violation of Bell inequality (or, Bell-type inequalities) by nonlocal
correlations is justified by relaxation of at least one of the plausible
physical constraints used to model such inequality. Based on this fact, in this
letter we present a procedure to simulate three-qubit GHZ correlation relaxing
two constraints, determinism and no signaling simultaneously. We have also
derived the minimum amount of indeterminism and signaling to be introduced in a
system. The corresponding number of signaling and local bits of mutual
information needed to communicate are also provided and thus we are able to
focus on utility of relaxation of these two constraints as useful resources.


title: The Topology of Probability Distributions on Manifolds

abstract:
  Let $P$ be a set of $n$ random points in $R^d$, generated from a probability
measure on a $m$-dimensional manifold $M \subset R^d$. In this paper we study
the homology of $U(P,r)$ -- the union of $d$-dimensional balls of radius $r$
around $P$, as $n \to \infty$, and $r \to 0$. In addition we study the critical
points of $d_P$ -- the distance function from the set $P$. These two objects
are known to be related via Morse theory. We present limit theorems for the
Betti numbers of $U(P,r)$, as well as for number of critical points of index
$k$ for $d_P$. Depending on how fast $r$ decays to zero as $n$ grows, these two
objects exhibit different types of limiting behavior. In one particular case
($n r^m > C \log n$), we show that the Betti numbers of $U(P,r)$ perfectly
recover the Betti numbers of the original manifold $M$, a result which is of
significant interest in topological manifold learning.


title:
Evidences to the pulse like origin of double spicules based on
  Hinode/SOT observations

abstract:
  We analyze the time series of H$\alpha$ line obtained from Hinode/SOT on the
solar limb. The wavelet analysis shows that there are nice correlations between
dynamical properties of the two parts of a double spicule. The dominant periods
for height variations are estimated ~90 and ~180 s. The length of two parts of
the spicule oscillates with the period of around ~180 s. The mean distance
between two parts of the spicule has a periodical treatment with the period of
~90 s. Our results show that the strong pulses may lead to the quasi periodic
rising of chromospheric plasma into the lower corona in the form of spicules.
The periodicity may result from the nonlinear wake behind the pulse in the
stratified atmosphere.


title: An expansion of zeta(3) in continued fraction with parameter

abstract:
  We present here continued fraction for Zeta(3) parametrized by some family of
points (F,G) on projective line. This family of points can be obtained if from
full projective line would be removed some no more than countable exeptional
set of finite points.
  A countable set, which contains the above exeptional set of finite points, is
specified also.


title:
Nonlinear Fokker-Planck equation: stability, distance and corresponding
  extremal problem in the spatially inhomogeneous case

abstract:
  We start with a global Maxwellian $M_{k}$, which is a stationary solution,
with the constant total density ($\rho(t)\equiv \wt \rho$), of the
Fokker-Planck equation. The notion of distance between the function $M_{k}$ and
an arbitrary solution $f$ (with the same total density $\wt \rho$ at the fixed
moment $t$) of the Fokker-Planck equation is introduced. In this way, we
essentially generalize the important Kullback-Leibler distance, which was
studied before. Using this generalization, we show local stability of the
global Maxwellians in the spatially inhomogeneous case. We compare also the
energy and entropy in the classical and quantum cases.


title:
Bayesian analysis to identify very low-mass members of nearby young
  stellar kinematic groups

abstract:
  We describe our all-sky survey for >M4 candidate members to nearby, young
associations from the 2MASS and WISE catalogs using bayesian inference. We
report the first results, including 38 highly probable candidates showing
spectroscopic signs of low-gravity (and thus youth). The latest of these
objects would correspond to a 11 - 13 MJup object, around the limit of the
planetary regime.


title: New Integrable Models from the Gauge/YBE Correspondence

abstract:
  We introduce a class of new integrable lattice models labeled by a pair of
positive integers N and r. The integrable model is obtained from the Gauge/YBE
correspondence, which states the equivalence of the 4d N=1 S^1 \times S^3/Z_r
index of a large class of SU(N) quiver gauge theories with the partition
function of 2d classical integrable spin models. The integrability of the model
(star-star relation) is equivalent with the invariance of the index under the
Seiberg duality. Our solution to the Yang-Baxter equation is one of the most
general known in the literature, and reproduces a number of known integrable
models. Our analysis identifies the Yang-Baxter equation with a particular
duality (called the Yang-Baxter duality) between two 4d N=1 supersymmetric
quiver gauge theories. This suggests that the integrability goes beyond 4d lens
indices and can be extended to the full physical equivalence among the IR fixed
points.

categories: hep-th cond-mat.stat-mech math-ph math.MP nlin.SI


title: The Effective Theory of Self-Interacting Dark Matter

abstract:
  We present an effective non-relativistic theory of self-interacting dark
matter. We classify the long range interactions and discuss how they can be
generated from quantum field theories. Generic dark sectors can generate
singular potentials. We show how to consistently renormalize such potentials
and apply this to the calculation of the Sommerfeld enhancement of dark matter
interactions. We explore further applications of this enhancement to
astrophysical probes of dark matter including the core vs. cusp problem.


title:
Controllable quantum spin glasses with magnetic impurities embedded in
  quantum solids

abstract:
  Magnetic impurities embedded in inert solids can exhibit long coherence times
and interact with one another via their intrinsic anisotropic dipolar
interaction. We argue that, as a consequence of these properties, disordered
ensembles of magnetic impurities provide an effective platform for realizing a
controllable, tunable version of the dipolar quantum spin glass seen in
LiHo$_x$Y$_{1-x}$F$_4$. Specifically, we propose and analyze a system composed
of dysprosium atoms embedded in solid helium. We describe the phase diagram of
the system and discuss the realizability and detectability of the quantum spin
glass and antiglass phases.

categories: cond-mat.quant-gas physics.atom-ph physics.chem-ph quant-ph


title:
Towards the determination of the photon parton distribution function
  constrained by LHC data

abstract:
  We provide a discussion of the impact of a subset of Drell-Yan data from LHC
on the determination of the photon parton distribution function (PDF), using
the NNPDF methodology. In previous work we have shown that the photon PDF
determined from deep-inelastic scattering (DIS) data only has large
uncertainties, suggesting the need for more data from other processes such as
Drell-Yan, which unlike DIS, includes photon-induced contributions at leading
order in QED. We describe the inclusion of ATLAS Drell-Yan W, Z data, which is
a subset of the LHC data used in a final photon PDF determination, by means of
a reweighting procedure. We show the impact of such data by comparing the
reweighted photon PDF with the photon PDF from DIS, highlighting the reduction
of uncertainties at medium/small-x. We conclude that the Drell-Yan data from
LHC allows a reasonably accurate determination of the photon PDF.


title: The holographic dual of an EPR pair has a wormhole

abstract:
  We construct the holographic dual of two colored quasiparticles in maximally
supersymmetric Yang-Mills theory entangled in a color singlet EPR pair. In the
holographic dual the entanglement is encoded in a geometry of a non-traversable
wormhole on the worldsheet of the flux tube connecting the pair. This gives a
simple example supporting the recent claim by Maldacena and Susskind that EPR
pairs and non-traversable wormholes are equivalent descriptions of the same
physics.


title:
Detection of water absorption in the day side atmosphere of HD 189733 b
  using ground-based high-resolution spectroscopy at 3.2 microns

abstract:
  We report a 4.8 sigma detection of water absorption features in the day side
spectrum of the hot Jupiter HD 189733 b. We used high-resolution (R~100,000)
spectra taken at 3.2 microns with CRIRES on the VLT to trace the
radial-velocity shift of the water features in the planet's day side atmosphere
during 5 h of its 2.2 d orbit as it approached secondary eclipse. Despite
considerable telluric contamination in this wavelength regime, we detect the
signal within our uncertainties at the expected combination of systemic
velocity (Vsys=-3 +5-6 km/s) and planet orbital velocity (Kp=154 +14-10 km/s),
and determine a H2O line contrast ratio of (1.3+/-0.2)x10^-3 with respect to
the stellar continuum. We find no evidence of significant absorption or
emission from other carbon-bearing molecules, such as methane, although we do
note a marginal increase in the significance of our detection to 5.1 sigma with
the inclusion of carbon dioxide in our template spectrum. This result
demonstrates that ground-based, high-resolution spectroscopy is suited to
finding not just simple molecules like CO, but also to more complex molecules
like H2O even in highly telluric contaminated regions of the Earth's
transmission spectrum. It is a powerful tool that can be used for conducting an
immediate census of the carbon- and oxygen-bearing molecules in the atmospheres
of giant planets, and will potentially allow the formation and migration
history of these planets to be constrained by the measurement of their
atmospheric C/O ratios.


title: The Velocity Distribution of Hypervelocity Stars

abstract:
  We consider the process of stellar binaries tidally disrupted by a
supermassive black hole. For highly eccentric orbits, as one star is ejected
from the three-body system, the companion remains bound to the black hole.
Hypervelocity stars (HVSs) observed in the Galactic halo and S-stars observed
orbiting the central black hole may originate from such mechanism. In this
paper, we predict the velocity distribution of the ejected stars of a given
mass, after they have travelled out of the Galactic potential. We use both
analytical methods and Monte Carlo simulations. We find that each part of the
velocity distribution encodes different information. At low velocities < 800
km/s, the Galactic Potential shapes universally the observed distribution,
which rises towards a peak, related to the Galactic escape velocity. Beyond the
peak, the velocity distribution depends on binary mass and separation
distributions. Finally, the finite star life introduces a break related to
their mass. A qualitative comparison of our models with current observations
shows the great potential of HVSs to constrain bulge and Galactic properties.
Standard choices for parameter distributions predict velocities below and above
~800 km/s with equal probability, while none are observed beyond ~700 km/s and
the current detections are more clustered at low velocities 300-400 km/s. These
features may indicate that the separation distribution of binaries that reach
the tidal sphere is not flat in logarithmic space, as observed in more local
massive binaries, but has more power towards larger separations, enhancing
smaller velocities. In addition, the binary formation/evolution process or the
injection mechanism might also induce a cut-off at ~ 10 solar radii in the
separation distribution.


title:
LoCuSS: The steady decline and slow quenching of star formation in
  cluster galaxies over the last four billion years

abstract:
  We present an analysis of the levels and evolution of star formation activity
in a representative sample of 30 massive galaxy clusters at 0.15<z<0.30 from
the Local Cluster Substructure Survey (LoCuSS), combining wide-field Spitzer
24um data with extensive spectroscopy of cluster members. The specific-SFRs of
massive (M>10^10 M_sun) star-forming cluster galaxies within r200 are found to
be systematically 28% lower than their counterparts in the field at fixed
stellar mass and redshift, a difference significant at the 8.7-sigma level.
This is the unambiguous signature of star formation in most (and possibly all)
massive star-forming galaxies being slowly quenched upon accretion into massive
clusters, their SFRs declining exponentially on quenching time-scales in the
range 0.7-2.0 Gyr. We measure the mid-infrared Butcher-Oemler effect over the
redshift range 0.0-0.4, finding rapid evolution in the fraction (f_SF) of
massive (M_K<-23.1) cluster galaxies within r200 with SFRs>3M_sun/yr, of the
form f_SF (1+z)^7.6. We dissect the origins of the Butcher-Oemler effect,
revealing it to be due to the combination of a ~3x decline in the mean
specific-SFRs of star-forming cluster galaxies since z~0.3 with a ~1.5x
decrease in number density. Two-thirds of this reduction in the specific-SFRs
of star-forming cluster galaxies is due to the steady cosmic decline in the
specific-SFRs among those field galaxies accreted into the clusters. The
remaining one-third reflects an accelerated decline in the star formation
activity of galaxies within clusters. The slow quenching of star-formation in
cluster galaxies is consistent with a gradual shut down of star formation in
infalling spiral galaxies as they interact with the intra-cluster medium via
ram-pressure stripping or starvation mechanisms. We find no evidence for the
build-up of cluster S0 bulges via major nuclear star-burst episodes.


title: Efficient Quantum Polar Codes Requiring No Preshared Entanglement

abstract:
  We construct an explicit quantum coding scheme which achieves a communication
rate not less than the coherent information when used to transmit quantum
information over a noisy quantum channel. For Pauli and erasure channels we
also present efficient encoding and decoding algorithms for this communication
scheme based on polar codes (essentially linear in the blocklength), but which
do not require the sender and receiver to share any entanglement before the
protocol begins. Due to the existence of degeneracies in the involved
error-correcting codes it is indeed possible that the rate of the scheme
exceeds the coherent information. We provide a simple criterion which indicates
such performance. Finally we discuss how the scheme can be used for secret key
distillation as well as private channel coding.


title: On the Starobinsky Model of Inflation from Supergravity

abstract:
  We discuss how the higher-derivative Starobinsky model of inflation
originates from N=1 supergravity. It is known that, in the old-minimal
supergravity description written by employing a chiral compensator in the
superconformal framework, the Starobinsky model is equivalent to a no-scale
model with F-term potential. We show that the Starobinsky model can also be
originated within the so-called new-minimal supergravity, where a linear
compensator superfield is employed. In this formulation, the Starobinsky model
is equivalent to standard supergravity coupled to a massive vector multiplet
whose lowest scalar component plays the role of the inflaton and the vacuum
energy is provided by a D-term potential. We also point out that higher-order
corrections to the supergravity Lagrangian represent a threat to the
Starobinsky model as they can destroy the flatness of the inflaton potential in
its scalar field equivalent description.


title: Decompositions and complexifications of homogeneous spaces

abstract:
  In this paper an extended CPR decomposition theorem for Finsler symmetric
spaces of semi-negative curvature in the context of reductive structures is
proven. This decomposition theorem is applied to give a geometric description
of the complexification of some infinite dimensional homogeneous spaces.