title: On Extremal Limits and Duality Orbits of Stationary Black Holes

abstract:
  With reference to the effective three-dimensional description of stationary,
single center solutions to (ungauged) symmetric supergravities, we complete a
previous analysis on the definition of a general geometrical mechanism for
connecting global symmetry orbits (duality orbits) of non-extremal solutions to
those of extremal black holes. We focus our attention on a generic
representative of these orbits, providing its explicit description in terms of
D=4 fields.
  As a byproduct, using a new characterization of the angular momentum in terms
of quantities intrinsic to the geometry of the D=3 effective model, we are able
to prove on general grounds its invariance, as a function of the boundary data,
under the D=4 global symmetry. In the extremal under-rotating limit it becomes
moduli-independent. We also discuss the issue of the fifth parameter
characterizing the four-dimensional seed solution, showing that it can be
generated by a transformation in the global symmetry group which is manifest in
the D=3 effective description.


title: Spectrum of excited states using the stochastic LapH method

abstract:
  Progress in computing the spectrum of excited baryons and mesons in lattice
QCD is described. Our first results in the zero-momentum bosonic I=1, S=0, T1u+
symmetry sector of QCD using a correlation matrix of 56 operators are
presented. In addition to a dozen spatially-extended meson operators, 44
two-meson operators are used, involving a wide variety of light isovector,
isoscalar, and strange meson operators of varying relative momenta. All needed
Wick contractions are efficiently evaluated using a stochastic method of
treating the low-lying modes of quark propagation that exploits Laplacian
Heaviside quark-field smearing. Level identification is discussed.


title: Park City lectures on Eigenfunctions

abstract:
  This is an expository article based on my lectures on eigenfunctions of the
Laplacian for the 2013 IAS/Park City Mathematics Institute (PCMI) summer school
in geometric analysis. Many of the results are based on joint work with H.
Christianson, J. Jung, C. Sogge, and J. Toth.


title:
Effects of External Radiation Fields on Line Emission - Application to
  Star-forming Regions

abstract:
  A variety of astronomical environments contain clouds irradiated by a
combination of isotropic and beamed radiation fields. For example, molecular
clouds may be irradiated by the isotropic cosmic microwave background (CMB), as
well as by a nearby active galactic nucleus (AGN). These radiation fields
excite atoms and molecules and produce emission in different ways. We revisit
the escape probability theorem and derive a novel expression that accounts for
the presence of external radiation fields. We show that when the field is
isotropic the escape probability is reduced relative to that in the absence of
external radiation. This is in agreement with previous results obtained under
ad hoc assumptions or with the two-level system, but can be applied to complex
many-level models of atoms or molecules. This treatment is in the development
version of the spectral synthesis code Cloudy. We examine the spectrum of a
Spitzer cloud embedded in the local interstellar radiation field, and show that
about 60 percent of its emission lines are sensitive to background subtraction.
We argue that this geometric approach could provide an additional tool toward
understanding the complex radiation fields of starburst galaxies.


title: List Sort: A New Approach for Sorting List to Reduce Execution Time

abstract:
  In this paper we are proposing a new sorting algorithm, List Sort algorithm,
is based on the dynamic memory allocation. In this research study we have also
shown the comparison of various efficient sorting techniques with List sort.
Due the dynamic nature of the List sort, it becomes much more fast than some
conventional comparison sorting techniques and comparable to Quick Sort and
Merge Sort. List sort takes the advantage of the data which is already sorted
either in ascending order or in descending order.


title: Quantization of borderline Levi conjugacy classes of orthogonal groups

abstract:
  We construct equivariant quantization of a special family of Levi conjugacy
classes of the complex orthogonal group $SO(N)$, whose stabilizer contains a
Cartesian factor $SO(2)\times SO(P)$, $1\leqslant P<N$, $P\equiv N \mod 2$.


title: On weighted covering numbers and the Levi-Hadwiger conjecture

abstract:
  We define new natural variants of the notions of weighted covering and
separation numbers and discuss them in detail. We prove a strong duality
relation between weighted covering and separation numbers and prove a few
relations between the classical and weighted covering numbers, some of which
hold true without convexity assumptions and for general metric spaces. As a
consequence, together with some volume bounds that we discuss, we provide a
bound for the famous Levi-Hadwiger problem concerning covering a convex body by
homothetic slightly smaller copies of itself, in the case of centrally
symmetric convex bodies, which is qualitatively the same as the best currently
known bound. We also introduce the weighted notion of the Levi-Hadwiger
covering problem, and settle the centrally-symmetric case, thus also confirm
Nasz\'{o}di's equivalent fractional illumination conjecture in the case of
centrally symmetric convex bodies (including the characterization of the
equality case, which was unknown so far).


title: LHC soft physics and TMD gluon density at low x

abstract:
  We study the unintegrated, or transverse momentum dependent (TMD) gluon
distribution obtained from the best description of the LHC data on the
inclusive spectra of hadrons produced in the mid-rapidity region and low
transverse momenta at starting scale Q0^2 = 1 GeV^2. To extend this gluon
density at higher Q^2 we apply the Catani-Ciafoloni-Fiorani-Marchesini (CCFM)
evolution equation. The influence of the initial (starting) non-perturbative
gluon distribution is studied. The application of the obtained gluon density to
the analysis of the ep deep inelastic scattering allows us to get the results
which describe reasonably well the H1 and ZEUS data on the longitudinal proton
structure function FL(x,Q^2). So, the connection between the soft processes at
LHC and small x physics at HERA has been confirmed and extended to a wide
kinematical region.


title: Electrovac Universes with a Cosmological Constant

abstract:
  We present the extension of the Einstein-Maxwell system called electrovac
universes by introducing a cosmological constant $\Lambda$. In the absence of
the $\Lambda$ term, the crucial equation in solving the Einstein-Maxwell system
is the Laplace equation. The cosmological constant modifies this equation to
become in a non-linear partial differential equation which takes the form
$\Delta U=2\Lambda U^3$. We offer special solutions of this equation.


title: Il fisico del neutrino

abstract:
  In memory of the famous physicist Bruno Pontecorvo, whereof is just occurred
the centenary anniversary of the birth and the twentieth anniversary of the
death, this paper traces the scientific and human adventure of the italian
scientist, from the pioneering studies of nuclear physics together with his
master Enrico Fermi, to the excellent results in particle physics, in
particular his research and insights about the neutrino. As much attention is
paid to the human experience, his relationship with politics and the choice to
embrace the Soviet socialist model. A short portrait to commemorate a scientist
symbol of the twentieth century.


title: Start-to-end simulation of the injector for a compact THz source

abstract:
  Terahertz radiation has broad application prospect due to its ability to
penetrate deep into many organic materials without damage caused by ionizing
radiations. A FEL-based THz source is the best choice to produce high-power
radiation. In this paper, a 14 MeV injector is introduced for generating
high-quality beam for FEL, which is composed of an EC-ITC RF gun, compensating
coils and a travelling-wave structure. Start-to-end simulation has been done
with ASTRA code to verify the design and to optimize parameters. Simulation of
operating mode at 6 MeV is also executed.


title: Positivity violations in QCD

abstract:
  Both lattice simulations and theoretical studies show that the spectral
function of the gluon propagator of QCD (in various gauges, as well as for the
gauge-invariant Pinch Technique, or PT, propagator) is not non-negative
everywhere, although it should be if it has a physical interpretation as in
QED. Theory says moreover that the non-positive spectral function of the
Landau-gauge or of the PT gluon propagator is further constrained to obey a
superconvergence relation (the integral of the spectral function vanishes). We
review the theoretical and lattice evidence for violation of positivity as well
as various interpretations of this violation, and consider methods for checking
superconvergence on the lattice (so far undone). The most common interpretation
is that positivity violation implies confinement of gluons, so the gluon
propagator does not describe processes with physical gluons. Another more
direct and gauge-invariant interpretation arises from the PT: Asymptotic
freedom alone demands non-positivity and superconvergence.


title: Moving in temporal graphs with very sparse random availability of edges

abstract:
  In this work we consider temporal graphs, i.e. graphs, each edge of which is
assigned a set of discrete time-labels drawn from a set of integers. The labels
of an edge indicate the discrete moments in time at which the edge is
available. We also consider temporal paths in a temporal graph, i.e. paths
whose edges are assigned a strictly increasing sequence of labels. Furthermore,
we assume the uniform case (UNI-CASE), in which every edge of a graph is
assigned exactly one time label from a set of integers and the time labels
assigned to the edges of the graph are chosen randomly and independently, with
the selection following the uniform distribution. We call uniform random
temporal graphs the graphs that satisfy the UNI-CASE. We begin by deriving the
expected number of temporal paths of a given length in the uniform random
temporal clique. We define the term temporal distance of two vertices, which is
the arrival time, i.e. the time-label of the last edge, of the temporal path
that connects those vertices, which has the smallest arrival time amongst all
temporal paths that connect those vertices. We then propose and study two
statistical properties of temporal graphs. One is the maximum expected temporal
distance which is, as the term indicates, the maximum of all expected temporal
distances in the graph. The other one is the temporal diameter which, loosely
speaking, is the expectation of the maximum temporal distance in the graph. We
derive the maximum expected temporal distance of a uniform random temporal star
graph as well as an upper bound on both the maximum expected temporal distance
and the temporal diameter of the normalized version of the uniform random
temporal clique, in which the largest time-label available equals the number of
vertices. Finally, we provide an algorithm that solves an optimization problem
on a specific type of temporal (multi)graphs of two vertices.


title: Evolution of autocatalytic sets in a competitive percolation model

abstract:
  The evolution of autocatalytic sets (ACS) is a widespread process in
biological, chemical and ecological systems which is of great significance in
many applications, such as the evolution of new species or complex chemical
organizations. In this paper, we propose a competitive model with a m-selection
rule in which an abrupt emergence of a macroscopic independent ACS is observed.
By numerical simulations, we find that the maximal increase of the size grows
linearly with the system size. We analytically derive the threshold t{\alpha}
where the abrupt jump happens and verify it by simulations. Moreover, our
analysis explains how this giant independent ACS grows and reveals that, as the
selection rule becomes more strict, the phase transition is dramatically
postponed, and the number of the largest independent ACSs coexisting in the
system increases accordingly. Our research work deepens the understanding of
the evolution of ACS and should provide useful information for designing
strategies to control the emergence of ACS in corresponding applications.


title: Including realistic tidal deformations in binary black-hole initial data

abstract:
  A shortcoming of current binary black-hole initial data is the generation of
spurious gravitational radiation, so-called junk radiation, when they are
evolved. This problem is a consequence of an oversimplified modeling of the
binary's physics in the initial data. Since junk radiation is not
astrophysically realistic, it contaminates the actual waveforms of interest and
poses a numerical nuisance. The work here presents a further step towards
mitigating and understanding the origin of this issue, by incorporating
post-Newtonian results in the construction of constraint-satisfying binary
black-hole initial data. Here we focus on including realistic tidal
deformations of the black holes in the initial data, by building on the method
of superposing suitably chosen black hole metrics to compute the conformal
data. We describe the details of our initial data for an equal-mass and
nonspinning binary, compute the subsequent relaxation of horizon quantities in
evolutions, and quantify the amount of junk radiation that is generated. These
results are contrasted with those obtained with the most common choice of
conformally flat (CF) initial data, as well as superposed Kerr-Schild (SKS)
initial data. We find that when realistic tidal deformations are included, the
early transients in the horizon geometries are significantly reduced, along
with smaller deviations in the relaxed black hole masses and spins from their
starting values. Likewise, the junk radiation content in the $l=2$ modes is
reduced by a factor of $\sim$1.7 relative to CF initial data, but only by a
factor of $\sim$1.2 relative to SKS initial data. More prominently, the junk
radiation content in the $3\leq l\leq8$ modes is reduced by a factor of $\sim$5
relative to CF initial data, and by a factor of $\sim$2.4 relative to SKS
initial data.


title: Constraints on Two-Component Dark Matter

abstract:
  We study 'Higgs Portal' 2-component Dark Matter scenario with two interacting
cold Dark Matter (DM) candidates: a neutral scalar singlet ($\varphi$) and a
neutral Majorana fermion ($\nu$). The relic abundance of $\varphi$ and $\nu$ is
found assuming thermal DM production and solving the Boltzmann equations. We
scan over the parameter space of the model to determine regions consistent with
the WMAP data for DM relic abundance and the XENON100 direct detection limits
for the DM-nucleus cross section.


title:
Small-scale local phenomena related to the magnetic reconnection and
  turbulence in the proximity of the heliopause

abstract:
  We study processes related to magnetic reconnection and plasma turbulence
occurring in the presence of the heliopause (HP) and the heliospheric current
sheet. It is shown that the interaction of plasmoids initiated by magnetic
reconnection may provide connections between the inner and outer heliosheath
and lead to an exchange of particles between the interstellar medium and the
solar wind plasma shocked at the heliospheric termination shock. The magnetic
reconnection may also cause plasma density and magnetic field compressions in
the proximity of the HP. We argue that these phenomena could possibly be
detected by the Voyager spacecraft approaching and crossing the HP. These
results could clarify the concepts of the "magnetic highway" and the
"heliosheath depletion region" recently proposed to explain recent Voyager 1
observations.

categories: astro-ph.SR physics.comp-ph physics.plasm-ph physics.space-ph


title: A reduction of semigroup DLP to classic DLP

abstract:
  We present a polynomial-time reduction of the discrete logarithm problem in
any periodic (a.k.a. torsion) semigroup (SGDLP) to the same problem in a
subgroup of the same semigroup. It follows that SGDLP can be solved in
polynomial time by quantum computers, and that SGDLP has subexponential
algorithms whenever the classic DLP in the corresponding groups has
subexponential algorithms.


title:
Problems and Results related to Waring's problem: Maximal functions and
  ergodic averages

abstract:
  We study the arithmetic analogue of maximal functions on diagonal
hypersurfaces. This paper is a natural step following the papers of
\cite{Magyar_dyadic}, \cite{Magyar_ergodic} and \cite{MSW}. We combine more
precise knowledge of oscillatory integrals and exponential sums to generalize
the asymptotic formula in Waring's problem to an approximation formula for the
fourier transform of the solution set of lattice points on hypersurfaces
arising in Waring's problem and apply this result to arithmetic maximal
functions and ergodic averages. In sufficiently large dimensions, the
approximation formula, $\ell^2$-maximal theorems and ergodic theorems were
previously known. Our contribution is in reducing the dimensional constraint in
the approximation formula using recent bounds of Wooley, and improving the
range of $\ell^p$ spaces in the maximal and ergodic theorems. We also
conjecture the expected range of spaces.


title: The development version of the CHEVIE package of GAP3

abstract:
  I describe the current state of the development version of the CHEVIE
package, which deals with Coxeter groups, reductive algebraic groups, complex
reflection groups, Hecke algebras, braid monoids, etc... Examples are given,
showing the code to check some results of Lusztig.


title:
Convergence Analysis of the Approximate Newton Method for Markov
  Decision Processes

abstract:
  Recently two approximate Newton methods were proposed for the optimisation of
Markov Decision Processes. While these methods were shown to have desirable
properties, such as a guarantee that the preconditioner is
negative-semidefinite when the policy is $\log$-concave with respect to the
policy parameters, and were demonstrated to have strong empirical performance
in challenging domains, such as the game of Tetris, no convergence analysis was
provided. The purpose of this paper is to provide such an analysis. We start by
providing a detailed analysis of the Hessian of a Markov Decision Process,
which is formed of a negative-semidefinite component, a positive-semidefinite
component and a remainder term. The first part of our analysis details how the
negative-semidefinite and positive-semidefinite components relate to each
other, and how these two terms contribute to the Hessian. The next part of our
analysis shows that under certain conditions, relating to the richness of the
policy class, the remainder term in the Hessian vanishes in the vicinity of a
local optimum. Finally, we bound the behaviour of this remainder term in terms
of the mixing time of the Markov chain induced by the policy parameters, where
this part of the analysis is applicable over the entire parameter space. Given
this analysis of the Hessian we then provide our local convergence analysis of
the approximate Newton framework.


title:
Multiple Solutions for Scalar Field Equations with Potentials having
  "Subsidences"

abstract:
  In this paper the question of finding infinitely many solutions to the
problem $-\Delta u+a(x)u=|u|^{p-2}u$, in $\mathbb{R}^N$, $u \in
H^1(\mathbb{R}^N)$, is considered when $N\geq 2$, $p \in (2, 2N/(N-2))$, and
the potential $a(x)$ is a positive function which is not required to enjoy
symmetry properties. Assuming that $a(x)$ satisfies a suitable "slow decay at
infinity" condition and, moreover, that its graph has some "dips", we prove
that the problem admits either infinitely many nodal solutions either
infinitely many constant sign solutions. The proof method is purely variational
and allows to describe the shape of the solutions.


title: Self-assembly at a nonequilibrium critical point

abstract:
  We use analytic theory and computer simulation to study patterns formed
during the growth of two-component assemblies in 2D and 3D. We show that these
patterns undergo a nonequilibrium phase transition, at a particular growth
rate, between mixed and demixed arrangements of component types. This finding
suggests that principles of nonequilibrium statistical mechanics can be used to
predict the outcome of multicomponent self-assembly, and suggests an
experimental route to the self-assembly of multicomponent structures of a
qualitatively defined nature.


title: On spectral sequences from Khovanov homology

abstract:
  There are a number of homological knot invariants, each satisfying an
unoriented skein exact sequence, which can be realized as the limit page of a
spectral sequence starting at a version of the Khovanov chain complex.
Compositions of elementary 1-handle movie moves induce a morphism of spectral
sequences. These morphisms remain unexploited in the literature, perhaps
because there is still an open question concerning the naturality of maps
induced by general movies.
  In this paper we focus on the spectral sequences due to Kronheimer-Mrowka
from Khovanov homology to instanton knot Floer homology, and on that due to
Ozsv\'ath-Szab\'o to the Heegaard-Floer homology of the branched double cover.
For example, we use the 1-handle morphisms to give new information about the
filtrations on the instanton knot Floer homology of the (4,5) torus knot,
determining these up to an ambiguity in a pair of degrees; to determine the
Ozsv\'ath-Szab\'o spectral sequence for an infinite class of prime knots; and
to show that higher differentials of both the Kronheimer-Mrowka and the
Ozsv\'ath-Szab\'o spectral sequences necessarily lower the delta grading for
all pretzel knots.


title:
Interaction effects on galaxy pairs with Gemini/GMOS- I: Electron
  density

abstract:
  We present an observational study about the impacts of the interactions in
the electron density of \ion{H}{ii} regions located in 7 systems of interacting
galaxies. The data consist of long-slit spectra in the range 4400-7300 A,
obtained with the Gemini Multi-Object Spectrograph at Gemini South (GMOS). The
electron density was determined using the ratio of emission lines
[SII]6716/6731. Our results indicate that the electron density estimates
obtained of HII regions from our sample of interacting galaxies are
systematically higher than those derived for isolated galaxies. The mean
electron density values of interacting galaxies are in the range of $N_{\rm
e}=24-532$\,$ \rm cm^{-3}$, while those obtained for isolated galaxies are in
the range of $N_{\rm e}=40-137\: \rm cm^{-3}$. Comparing the observed emission
lines with predictions of photoionization models, we verified that almost all
the \ion{H}{ii} regions of the galaxies AM\,1054A, AM\,2058B, and AM\,2306B,
have emission lines excited by shock gas. For the remaining galaxies, only few
HII regions has emission lines excited by shocks, such as in AM\,2322B (1
point), and AM\,2322A (4 points). No correlation is obtained between the
presence of shocks and electron densities. Indeed, the highest electron density
values found in our sample do not belong to the objects with gas shock
excitation. We emphasize the importance of considering theses quantities
especially when the metallicity is derived for these types of systems.


title: Compact manifolds with computable boundaries

abstract:
  We investigate conditions under which a co-computably enumerable closed set
in a computable metric space is computable and prove that in each locally
computable computable metric space each co-computably enumerable compact
manifold with computable boundary is computable. In fact, we examine the notion
of a semi-computable compact set and we prove a more general result: in any
computable metric space each semi-computable compact manifold with computable
boundary is computable. In particular, each semi-computable compact
(boundaryless) manifold is computable.


title: Regularity of squarefree monomial ideals

abstract:
  We survey a number of recent studies of the Castelnuovo-Mumford regularity of
squarefree monomial ideals. Our focus is on bounds and exact values for the
regularity in terms of combinatorial data from associated simplicial complexes
and/or hypergraphs.


title:
Multiwavelength Observations of The TeV Binary LS I +61 303 with
  VERITAS, Fermi-LAT and Swift-XRT During a TeV Outburst

abstract:
  We present the results of a multiwavelength observational campaign on the TeV
binary system LS I +61 303 with the VERITAS telescope array (>200 GeV),
Fermi-LAT (0.3-300 GeV), and Swift-XRT (2-10 keV). The data were taken from
December 2011 through January 2012 and show a strong detection in all three
wavebands. During this period VERITAS obtained 24.9 hours of quality selected
livetime data in which LS I +61 303 was detected at a statistical sig-
nificance of 11.9 sigma. These TeV observations show evidence for nightly
variability in the TeV regime at a post-trial significance of 3.6 sigma. The
combination of the simultaneously obtained TeV and X-ray fluxes do not
demonstrate any evidence for a correlation between emission in the two bands.
For the first time since the launch of the Fermi satellite in 2008, this TeV
detection allows the construction of a detailed MeV-TeV spectral energy
distribution from LS I +61 303. This spectrum shows a distinct cutoff in
emission near 4 GeV, with emission seen by the VERITAS observations following a
simple power-law above 200 GeV. This feature in the spectrum of LS I +61 303,
obtained from overlapping observations with Fermi-LAT and VERITAS, may indicate
that there are two distinct populations of accelerated particles producing the
GeV and TeV emission.


title: The capacity of black holes to transmit quantum information

abstract:
  We study the properties of the quantum information transmission channel that
emerges from the quantum dynamics of particles interacting with a black hole
horizon. We calculate the quantum channel capacity in two limiting cases where
a single-letter capacity is known to exist: the limit of perfectly reflecting
and perfectly absorbing black holes. We find that the perfectly reflecting
black hole channel is closely related to the Unruh channel and that its
capacity is non-vanishing, allowing for the perfect reconstruction of quantum
information outside of the black hole horizon. We also find that the
complementary channel (transmitting entanglement behind the horizon) is
entanglement-breaking in this case, with vanishing capacity. We then calculate
the quantum capacity of the black hole channel in the limit of a perfectly
absorbing black hole and find that this capacity vanishes, while the capacity
of the complementary channel is non-vanishing instead. Rather than inviting a
new crisis for quantum physics, this finding instead is in accordance with the
quantum no-cloning theorem, because it guarantees that there are no space-like
surfaces that contain both the sender's quantum state and the receiver's
reconstructed quantum state.


title:
Ward identities and consistency relations for the large scale structure
  with multiple species

abstract:
  We present fully nonlinear consistency relations for the squeezed bispectrum
of Large Scale Structure. These relations hold when the matter component of the
Universe is composed of one or more species, and generalize those obtained in
Peloso, Pietroni '13 and Kehagias, Riotto '13 in the single species case. The
multi-species relations apply to the standard dark matter + baryons scenario,
as well as to the case in which some of the fields are auxiliary quantities
describing a particular population, such as dark matter halos or a specific
galaxy class. If a large scale velocity bias exists between the different
populations new terms appear in the consistency relations with respect to the
single species case. As an illustration, we discuss two physical cases in which
such a velocity bias can exist: (1) a new long range scalar force in the dark
matter sector (resulting in a violation of the equivalence principle in the
dark matter-baryon system), and (2) the distribution of dark matter halos
relative to that of the underlying dark matter field.


title:
Feeding and Feedback in the Inner Kiloparsec of the Active Galaxy
  NGC2110

abstract:
  We present two-dimensional gaseous kinematics of the inner 1.1 x 1.6kpc^2 of
the Seyfert 2 galaxy NGC2110, from optical spectra obtained with the GMOS
integral field spectrograph on the Gemini South telescope at a spatial
resolution of 100pc. Gas emission is observed over the whole field-of-view,
with complex - and frequently double - emission-line profiles. We have
identified four components in the emitting gas, according to their velocity
dispersion (sigma), which we refer to as: (1) warm gas disk (sigma =
100-220km/s); (2) cold gas disk (sigma = 60-90km/s); (3) nuclear component
(sigma = 220-600km/s); and (4) northern cloud (sigma = 60-80km/s). Both the
cold and warm disk components are dominated by rotation and have similar gas
densities, but the cold gas disk has lower velocity dispersions and reaches
higher rotation velocities. We attribute the warm gas disk to a thick gas layer
which encompasses the cold disk as observed in some edge-on spiral galaxies.
After subtraction of a rotation model from the cold disk velocity field, we
observe excess blueshifts of 50km/s in the far side of the galaxy as well as
similar excess redshifts in the near side. These residuals can be interpreted
as due to nuclear inflow in the cold gas, with an estimated ionized gas mass
inflow rate of 2.2 x 10^(-2)Msun/yr. We have also subtracted a rotating model
from the warm disk velocity field and found excess blueshifts of 100km/s to the
SW of the nucleus and excess redshifts of 40km/s to the NE, which we attribute
to gas disturbed by an interaction with a nuclear spherical outflow. This
nuclear outflow is the origin of the nuclear component observed within the
inner 300pc and it has a mass outflow rate of 0.9Msun/yr. In a region between
1" and 4" north of the nucleus we find a new low sigma component of ionized gas
which we attribute to a high latitude cloud photoionized by the nuclear source.


title: Galois Cohomology of Real Groups

abstract:
  Real forms of a complex reductive group are classified in terms of Galois
cohomology $H^1(\Gamma,G_{ad})$ where $G_{ad}$ is the adjoint group.
Alternatively, the theory of the Cartan involution gives a description in terms
of cohomology with respect to a holomorphic involution: $H^1(\mathbb Z/2\mathbb
Z,G_{ad})$ where the non trivial element acts by a holomorphic involution
$\theta$.
  The main theorem is that in general, if $\theta$ is the Cartan involution of
a real form $\sigma$, there is a canonical isomorphism $H^1(\Gamma,G)\simeq
H^1(\mathbb Z/2\mathbb Z,G)$.
  This has applications to the structure and representation theory of real
groups. We give two such applications. The first is a simple proof of Matsuki's
result on conjugacy classes of tori in real groups. The second is a computation
of $H^1(\Gamma,G)$ in general. The answer is expressed in terms of the notion
of strong real forms. We include tables for all simply connected simple groups.


title:
Applications of threshold models and the weighted bootstrap for
  Hungarian precipitation data

abstract:
  This paper presents applications of the peaks-over threshold methodology for
both the univariate and the recently introduced bivariate case, combined with a
novel bootstrap approach. We compare the proposed bootstrap methods to the more
traditional profile likelihood.
  We have investigated 63 years of the European Climate Assessment daily
precipitation data for five Hungarian grid points, first separately for the
summer and winter months, then aiming at the detection of possible changes by
investigating 20 years moving windows. We show that significant changes can be
observed both in the univariate and the bivariate cases, the most recent period
being the most dangerous, as the return levels here are the highest. We
illustrate these effects by bivariate coverage regions.


title: The age of information in gossip networks

abstract:
  We introduce models of gossip based communication networks in which each node
is simultaneously a sensor, a relay and a user of information. We model the
status of ages of information between nodes as a discrete time Markov chain. In
this setting a gossip transmission policy is a decision made at each node
regarding what type of information to relay at any given time (if any). When
transmission policies are based on random decisions, we are able to analyze the
age of information in certain illustrative structured examples either by means
of an explicit analysis, an algorithm or asymptotic approximations. Our key
contribution is presenting this class of models.


title: Creation of Peanut-Shaped Bulges via the Slow Mode of Bar Growth

abstract:
  Recent theoretical work has implicated fast bar formation modes and
subsequent evolution as the creation mechanism for the observed peanut-shaped
bulges in some edge-on disk galaxies. We demonstrate an N-body simulation of a
disk undergoing a contrasting slow mode of bar growth, unsubjected to a
buckling instability, which nonetheless grows the 4:1 orbit family responsible
for a peanut-shaped bulge. We also present a simulation with fast mode bar
growth, which exhibits thickening similar to other work. A novel orbit
classification method that finds dynamically distinct families is presented,
allowing for a detailed analysis of angular momentum transfer channels within
the disk.


title: Area Products and Mass Formula for Kerr-Newman-Taub-NUT Space-time

abstract:
  We derive area product, entropy product, area sum and entropy sum of the
event horizon and Cauchy horizons for
Kerr-Newman-Taub-NUT(Newman-Unti-Tamburino) black hole in four dimensional
\emph{Lorentzian geometry}. We observe that these thermodynamic products are
\emph{not} universal(mass-independence) for this black hole(BH), whereas for
Kerr-Newman(KN) BH such products are universal (mass-independence). We also
examine the entropy sum and area sum. It is shown that they all are depends on
mass, charge and NUT parameter of the back ground space-time. Thus we can
conclude that the universal(mass-independence) behaviour of area product and
entropy product, area sum and entropy sum for Kerr-Newman-Taub-NUT(KNTN) BH
fails and which is also quite different from KN BH. We further show that the
KNTN BH do not possess \emph{first law of BH thermodynamics } and \emph
{Smarr-Gibbs-Duhem } relations, and that such relations are unlikely in the KN
case. The failure of these aforementioned features are due to presence of the
non-trivial NUT charge which makes the space-time to be asymptotically
non-flat, in contrast with KN BH. The another reason of the failure is that
Lorentzian KNTN geometry contains \emph{Dirac-Misner type singularity}, which
is a manifestation of a non-trivial topological twist of the manifold. The BH
\emph{mass formula} and \emph{Christodoulou-Ruffini mass formula} for KNTN
black holes are also derived. Finally, we compute the area bound which is just
Penrose like inequality for event horizon. From area bound we derive entropy
bound. These thermodynamic products on the multi horizon playing a crucial role
in BH thermodynamics to understand the microscopic nature of BH entropy.


title: Precision Tau Physics

abstract:
  Precise measurements of the lepton properties provide stringent tests of the
Standard Model and accurate determinations of its parameters. We overview the
present status of tau physics, highlighting the most recent developments, and
discuss the prospects for future improvements. The leptonic decays of the tau
lepton probe the structure of the weak currents and the universality of their
couplings to the W boson. The universality of the leptonic Z couplings has also
been tested through leptonic Z decays. The hadronic tau decay modes constitute
an ideal tool for studying low-energy effects of the strong interaction in very
clean conditions. Accurate determinations of the QCD coupling and the Cabibbo
mixing have been obtained with tau data. The large mass of the tau opens the
possibility to study many kinematically-allowed exclusive decay modes and
extract relevant dynamical information. Violations of flavour and CP
conservation laws can also be searched for with tau decays. Related subjects
such as muon decays, the electron and muon anomalous magnetic moments, neutrino
mixing and B-meson decays into tau leptons are briefly covered. Being one the
fermions most strongly coupled to the scalar sector, the tau lepton is playing
now a very important role at the LHC as a tool to test the Higgs properties and
search for new physics at higher scales.


title: Self-consistent neutrino and UHE cosmic ray spectra from Mrk 421

abstract:
  We examine the neutrino and cosmic ray spectra resulting from two models of
fitting the spectral energy distribution (SED) of the blazar Mrk~421 using a
self-consistent leptohadronic code. The $\gamma$-ray emission is attributed to
either synchrotron radiation of ultra-high energy protons (LHs model) or to
synchrotron radiation from electrons that result from photopion interactions of
lower energy protons (LH$\pi$ model). Although both models succeed in fitting
satisfactorily the SED, the parameter values that they use result in
significantly different neutrino and cosmic-ray spectra. For the LH$\pi$ model,
which requires high proton energy density, we find that the neutrino spectrum
peaks at an energy $E_{\rm \nu,peak}= 3.3$ PeV which falls well within the
energy range of recent neutrino observations. While at the same time its peak
flux is just under the sensitivity limit of IC-40 observations, it cannot
produce ultra-high energy cosmic rays. In the LHs model, on the other hand,
neutrinos are far from being detectable because of their low flux and peak
energy at $E_{{\rm \nu,peak}} \simeq 100$ PeV. However, the propagation of
protons produced by the decay of escaping neutrons results in an ultra-high
energy cosmic ray flux close to that observed by Pierre Augere, HiRes and
Telescope Array at energies $E_p \simeq 30$ EeV.


title:
Modelling Solar Oscillation Power Spectra: II. Parametric Model of
  Spectral Lines Observed in Doppler Velocity Measurements

abstract:
  We describe a global parametric model for the observed power spectra of solar
oscillations of intermediate and low degree. A physically motivated
parameterization is used as a substitute for a direct description of mode
excitation and damping as these mechanisms remain poorly understood. The model
is targeted at the accurate fitting of power spectra coming from Doppler
velocity measurements and uses an adaptive response function that accounts for
both the vertical and horizontal components of the velocity field on the solar
surface and for possible instrumental and observational distortions. The model
is continuous in frequency, can easily be adapted to intensity measurements and
extends naturally to the analysis of high-frequency pseudo modes (interference
peaks at frequencies above the atmospheric acoustic cutoff).


title: Universal entanglement crossover of coupled quantum wires

abstract:
  We consider the entanglement between two one-dimensional quantum wires
(Luttinger Liquids) coupled by tunneling through a quantum impurity. The
physics of the system involves a crossover between weak and strong coupling
regimes characterized by an energy scale $T_B$, and methods of conformal field
theory therefore cannot be applied. The evolution of the entanglement in this
crossover has led to many numerical studies, but has remained little
understood, analytically or even qualitatively. We argue in this Letter that
the correct universal scaling form of the entanglement entropy $S$ (for an
arbitrary interval of length $L$ containing the impurity) is $\partial
S/\partial \ln L = f(L T_B)$. In the special case where the coupling to the
impurity can be refermionized, we show how the universal function $f(L T_B)$
can be obtained analytically using recent results on form factors of twist
fields and a defect massless-scattering formalism. Our results are carefully
checked against numerical simulations.


title:
Phase characteristics of electromagnetically induced transparency
  analogue in coupled resonant systems

abstract:
  Electromagnetically induced transparency (EIT) and EIT-like effects have been
investigated in a wide variety of coupled resonant systems. Here, a
classification of the phase characteristics of the EIT-like spectral responses
is presented. Newly identified phase responses reveal unexplored operation
regimes of EIT-like systems. Taking advantage of the new phase regimes, one can
obtain group delay, dispersion and nonlinearity properties greatly enhanced by
almost one order of magnitude, compared to the traditionally constructed
EIT-like devices, which breaks the fundamental limitation (e.g.,
delay-bandwidth product) intrinsic to atomic EIT and EIT-like effects. Optical
devices and electrical circuits are analyzed as examples showing the
universality of our finding. We show that cavity-QED-based quantum phase gates
can be greatly improved to achieve a phase shift of {\pi}. The new phase
characteristics are also believed to be useful to build novel doubly resonant
devices in quantum information based on cavity QED, optomechanics, and
metamaterials.


title: Resonant periodic orbits in the exoplanetary systems

abstract:
  The planetary dynamics of $4/3$, $3/2$, $5/2$, $3/1$ and $4/1$ mean motion
resonances is studied by using the model of the general three body problem in a
rotating frame and by determining families of periodic orbits for each
resonance. Both planar and spatial cases are examined. In the spatial problem,
families of periodic orbits are obtained after analytical continuation of
vertical critical orbits. The linear stability of orbits is also examined.
Concerning initial conditions nearby stable periodic orbits, we obtain
long-term planetary stability, while unstable orbits are associated with
chaotic evolution that destabilizes the planetary system. Stable periodic
orbits are of particular importance in planetary dynamics, since they can host
real planetary systems. We found stable orbits up to $60^\circ$ of mutual
planetary inclination, but in most families, the stability does not exceed
$20^\circ$-$30^\circ$, depending on the planetary mass ratio. Most of these
orbits are very eccentric. Stable inclined circular orbits or orbits of low
eccentricity were found in the $4/3$ and $5/2$ resonance, respectively.


title: Faint Dwarfs in Nearby Groups

abstract:
  The number and distribution of dwarf satellite galaxies remain a critical
test of cold dark matter-dominated structure formation on small scales. Until
recently, observational information about galaxy formation on these scales has
been limited mainly to the Local Group. We have searched for faint analogues of
Local Group dwarfs around nearby bright galaxies, using a spatial clustering
analysis of the photometric catalog of the Sloan Digital Sky Survey (SDSS) Data
Release 8. Several other recent searches of SDSS have detected clustered
satellite populations down to $\Delta m_r \equiv ({m}_{r,\, {\rm sat}} -\,
{m}_{r,\, {\rm main}}) \sim 6$-$8$, using photometric redshifts to reduce
background contamination. SDSS photometric redshifts are relatively imprecise,
however, for faint and nearby galaxies. Instead we use angular size to select
potential nearby dwarfs, and consider only the nearest isolated bright galaxies
as primaries. As a result, we are able to detect an excess clustering signal
from companions down to $\Delta m_r = 12$, four magnitudes fainter than most
recent studies. We detect an over-density of objects at separations $< 400$
kpc, corresponding to about $4.6 \pm 0.5$ satellites per central galaxy,
consistent with the satellite abundance expected from the Local Group given our
selection function. Although the sample of satellites detected is incomplete by
construction, since it excludes the least and most compact dwarfs, this
detection provides a lower bound on the average satellite luminosity function,
down to luminosities corresponding to the faintest "classical" dwarfs of the
Local Group.


title: Conformal Quivers and Melting Molecules

abstract:
  Quiver quantum mechanics describes the low energy dynamics of a system of
wrapped D-branes. It captures several aspects of single and multicentered BPS
black hole geometries in four-dimensional $\mathcal{N} = 2$ supergravity such
as the presence of bound states and an exponential growth of microstates. The
Coulomb branch of an Abelian three node quiver is obtained by integrating out
the massive strings connecting the D-particles. It allows for a scaling regime
corresponding to a deep AdS$_2$ throat on the gravity side. In this scaling
regime, the Coulomb branch is shown to be an $SL(2,\mathbb{R})$ invariant
multi-particle superconformal quantum mechanics. Finally, we integrate out the
strings at finite temperature---rather than in their ground state---and show
how the Coulomb branch `melts' into the Higgs branch at high enough
temperatures. For scaling solutions the melting occurs for arbitrarily small
temperatures, whereas bound states can be metastable and thus long lived.
Throughout the paper, we discuss how far the analogy between the quiver model
and the gravity picture, particularly within the AdS$_2$ throat, can be taken.


title: Differential cohomology in a cohesive infinity-topos

abstract:
  We formulate differential cohomology and Chern-Weil theory -- the theory of
connections on fiber bundles and of gauge fields -- abstractly in the context
of a certain class of higher toposes that we call "cohesive". Cocycles in this
differential cohomology classify higher principal bundles equipped with
cohesive structure (topological, smooth, synthetic differential,
supergeometric, etc.) and equipped with connections, hence higher gauge fields.
We discuss various models of the axioms and applications to fundamental notions
and constructions in quantum field theory and string theory. In particular we
show that the cohesive and differential refinement of universal characteristic
cocycles constitutes a higher Chern-Weil homomorphism refined from secondary
caracteristic classes to morphisms of higher moduli stacks of higher gauge
fields, and at the same time constitutes extended geometric prequantization --
in the sense of extended/multi-tiered quantum field theory -- of hierarchies of
higher dimensional Chern-Simons-type field theories, their higher
Wess-Zumino-Witten-type boundary field theories and all further higher
codimension defect field theories. We close with an outlook on the
cohomological quantization of such higher boundary prequantum field theories by
a kind of cohesive motives.


title: Minimal sets determining the topological centre of the algebra LUC(G)*

abstract:
  The Banach algebra LUC(G)* associated to a topological group G has been of
interest in abstract harmonic analysis. A number of authors have studied the
topological centre of LUC(G)*, which is defined as the set of elements in
LUC(G)* for which the left multiplication is w*--w*-continuous on LUC(G)*.
Several recent works show that for a locally compact group G it is sufficient
to test the continuity of the left multiplication at just one specific point in
order to determine whether an element of LUC(G)* belongs to the topological
centre. In this work we extend some of these results to a much larger class of
groups which includes many non-locally compact groups as well as all the
locally compact ones. This answers a question raised by H.G. Dales. We also
obtain a corollary about the topological centre of any subsemigroup of LUC(G)*
containing the uniform compactification of G. In particular, we prove that
there are sets of just one point determining the topological centre of the
uniform compactification itself.


title: Complete set of circuit equations for Stabilizer Quantum Mechanics

abstract:
  We find a sufficient set of equations between quantum circuits from which we
can derive any other equation between stabilizer quantum circuits. To establish
this result, we rely upon existing work on the completeness of the graphical ZX
language for quantum processes. The complexity of the circuit equations, as
opposed to the very intuitive reading of the much smaller number of
ZX-equations, advocates the latter for performing computations with quantum
circuits.


title: $G_2$-instantons on twisted connected sums

abstract:
  We introduce a method to construct $G_2$-instantons over compact
$G_2$-manifolds arising as the twisted connected sum of a matching pair of
building blocks [Kov03,KL11,CHNP12]. Our construction is based on gluing
$G_2$-instantons obtained from holomorphic bundles over the building blocks via
the first named author's work [SE11]. We require natural compatibility and
transversality conditions which can be interpreted in terms of certain
Lagrangian subspaces of a moduli space of stable bundles on a K3 surface.


title: Dynamics of harmonically confined systems: some rigorous results

abstract:
  In this paper we consider the dynamics of harmonically-confined atomic gases.
We present various general results which are independent of particle
statistics, interatomic interactions and dimensionality. Of particular interest
is the response of the system to external perturbations having either a static
or dynamic nature. We prove an extended Harmonic Potential Theorem which is
useful in determining the damping of the centre of mass motion for some
initially prepared nonequilibrium state. We also study the response of the gas
to a dynamic perturbation in which the external potential oscillates at an
arbitrary frequency. We show in this case that either the energy absorption
rate or the centre of mass dynamics can serve as a probe of the optical
conductivity of the system.


title: The Unreasonable Fundamental Incertitudes Behind Bitcoin Mining

abstract:
  Bitcoin is a "crypto currency", a decentralized electronic payment scheme
based on cryptography which has recently gained excessive popularity.
Scientific research on bitcoin is less abundant. A paper at Financial
Cryptography 2012 conference explains that it is a system which "uses no fancy
cryptography", and is "by no means perfect". It depends on a well-known
cryptographic standard SHA-256. In this paper we revisit the cryptographic
process which allows one to make money by producing bitcoins. We reformulate
this problem as a Constrained Input Small Output (CISO) hashing problem and
reduce the problem to a pure block cipher problem. We estimate the speed of
this process and we show that the cost of this process is less than it seems
and it depends on a certain cryptographic constant which we estimated to be at
most 1.86. These optimizations enable bitcoin miners to save tens of millions
of dollars per year in electricity bills. Miners who set up mining operations
face many economic incertitudes such as high volatility. In this paper we point
out that there are fundamental incertitudes which depend very strongly on the
bitcoin specification. The energy efficiency of bitcoin miners have already
been improved by a factor of about 10,000, and we claim that further
improvements are inevitable. Better technology is bound to be invented, would
it be quantum miners. More importantly, the specification is likely to change.
A major change have been proposed in May 2013 at Bitcoin conference in San
Diego by Dan Kaminsky. However, any sort of change could be flatly rejected by
the community which have heavily invested in mining with the current
technology. Another question is the reward halving scheme in bitcoin. The
current bitcoin specification mandates a strong 4-year cyclic property. We find
this property totally unreasonable and harmful and explain why and how it needs
to be changed.


title: Detecting the 21 cm Forest in the 21 cm Power Spectrum

abstract:
  We describe a new technique for constraining the radio loud population of
active galactic nuclei at high redshift by measuring the imprint of 21 cm
spectral absorption features (the 21 cm forest) on the 21 cm power spectrum.
Using semi-numerical simulations of the intergalactic medium and a
semi-empirical source population we show that the 21 cm forest dominates a
distinctive region of $k$-space, $k \gtrsim 0.5 \text{Mpc}^{-1}$. By simulating
foregrounds and noise for current and potential radio arrays, we find that a
next generation instrument with a collecting area on the order of $\sim
0.1\text{km}^2$ (such as the Hydrogen Epoch of Reionization Array) may
separately constrain the X-ray heating history at large spatial scales and
radio loud active galactic nuclei of the model we study at small ones. We
extrapolate our detectability predictions for a single radio loud active
galactic nuclei population to arbitrary source scenarios by analytically
relating the 21 cm forest power spectrum to the optical depth power spectrum
and an integral over the radio luminosity function.


title:
The neutron star transient and millisecond pulsar in M28: from
  sub-luminous accretion to rotation-powered quiescence

abstract:
  The X-ray transient IGR J18245-2452 in the globular cluster M28 contains the
first neutron star (NS) seen to switch between rotation-powered and
accretion-powered pulsations. We analyse its 2013 March-April 25d-long outburst
as observed by Swift, which had a peak bolometric luminosity of ~6% of the
Eddington limit (L$_{E}$), and give detailed properties of the thermonuclear
burst observed on 2013 April 7. We also present a detailed analysis of new and
archival Chandra data, which we use to study quiescent emission from IGR
J18245-2452 between 2002 and 2013. Together, these observations cover almost
five orders of magnitude in X-ray luminosity (L$_X$, 0.5-10 keV). The Swift
spectrum softens during the outburst decay (photon index $\Gamma$ from 1.3
above L$_X$/L$_{E}$=10$^{-2}$ to ~2.5 at L$_X$/L$_{E}$=10$^{-4}$), similar to
other NS and black hole (BH) transients. At even lower luminosities, deep
Chandra observations reveal hard ($\Gamma$=1-1.5), purely non-thermal and
highly variable X-ray emission in quiescence. We therefore find evidence for a
spectral transition at L$_X$/L$_{E}$~10$^{-4}$, where the X-ray spectral
softening observed during the outburst decline turns into hardening as the
source goes to quiescence. Furthermore, we find a striking variability pattern
in the 2008 Chandra light curves: rapid switches between a high-L$_X$ "active"
state (L$_X\simeq$3.9x10$^{33}$ erg/s) and a low-L$_X$ "passive" state
(L$_X\simeq$5.6x10$^{32}$ erg/s), with no detectable spectral change. We put
our results in the context of low luminosity accretion flows around compact
objects and X-ray emission from millisecond radio pulsars. Finally, we discuss
possible origins for the observed mode switches in quiescence, and explore a
scenario where they are caused by fast transitions between the magnetospheric
accretion and pulsar wind shock emission regimes.


title:
Magnetic Field Response and Chiral Symmetry of Time Reversal Invariant
  Topological Superconductors

abstract:
  We study the magnetic field response of the Majorana Kramers pairs of a
one-dimensional time-reversal invariant (TRI) superconductors (class DIII) with
or without a coexisting chirality symmetry. For unbroken TR and chirality
invariance the parameter regimes for nontrivial values of the (Z_2)
DIII-invariant and the (Z) chiral invariant coincide. However, broken TR may or
may not be accompanied by broken chirality, and if chiral symmetry is unbroken,
the pair of Majorana fermions (MFs) at a given end survives the loss of TR
symmetry in an entire plane perpendicular to the spin-orbit coupling field.
Conversely, we show that broken chirality may or may not be accompanied by
broken TR, and if TR is unbroken, the pair of MFs survives the loss of broken
chirality. In addition to explaining the anomalous magnetic field response of
all the DIII class TS systems proposed in the literature, we provide a
realistic route to engineer a "true" TR-invariant TS, whose pair of MFs at each
end is split by an applied Zeeman field in arbitrary direction. We also prove
that, quite generally, the splitting of the MFs by TR-breaking fields in TRI
superconductors is highly anisotropic in spin space, even in the absence of the
topological chiral symmetry.


title:
The Influence of the Magnetic Field on Running Penumbral Waves in the
  Solar Chromosphere

abstract:
  We use images of high spatial and temporal resolution, obtained using both
ground- and space-based instrumentation, to investigate the role magnetic field
inclination angles play in the propagation characteristics of running penumbral
waves in the solar chromosphere. Analysis of a near-circular sunspot, close to
the center of the solar disk, reveals a smooth rise in oscillatory period as a
function of distance from the umbral barycenter. However, in one directional
quadrant, corresponding to the north direction, a pronounced kink in the
period-distance diagram is found. Utilizing a combination of the inversion of
magnetic Stokes vectors and force-free field extrapolations, we attribute this
behaviour to the cut-off frequency imposed by the magnetic field geometry in
this location. A rapid, localised inclination of the magnetic field lines in
the north direction results in a faster increase in the dominant periodicity
due to an accelerated reduction in the cut-off frequency. For the first time we
reveal how the spatial distribution of dominant wave periods, obtained with one
of the highest resolution solar instruments currently available, directly
reflects the magnetic geometry of the underlying sunspot, thus opening up a
wealth of possibilities in future magneto-hydrodynamic seismology studies. In
addition, the intrinsic relationships we find between the underlying magnetic
field geometries connecting the photosphere to the chromosphere, and the
characteristics of running penumbral waves observed in the upper chromosphere,
directly supports the interpretation that running penumbral wave phenomena are
the chromospheric signature of upwardly-propagating magneto-acoustic waves
generated in the photosphere.


title: Generic spin model for the honeycomb iridates beyond the Kitaev limit

abstract:
  Recently, realizations of Kitaev physics have been sought in the A2IrO3
family of honeycomb iridates, originating from oxygen-mediated exchange through
edge-shared octahedra. However, for the j = 1/2 Mott insulator in these
materials exchange from direct d-orbital overlap is relevant, and it was
proposed that a Heisenberg term should be added to the Kitaev model. Here we
provide the generic nearest-neighbour spin Hamiltonian when both
oxygen-mediated and direct overlap are present, containing a bond dependent
off-diagonal exchange in addition to Heisenberg and Kitaev terms. We analyze
this complete model using a combination of classical techniques and exact
diagonalization. Near the Kitaev limit, we find new magnetic phases, 120 degree
and incommensurate spiral order, as well as extended regions of zigzag and
stripy order. Possible applications to Na2IrO3 and Li2IrO3 are discussed.


title: Towards a general analysis of LHC data within two-Higgs-doublet models

abstract:
  The data accumulated so far confirm the Higgs-like nature of the new boson
discovered at the LHC. The Standard Model Higgs hypothesis is compatible with
the collider results and no significant deviations from the Standard Model have
been observed neither in the flavour sector nor in electroweak precision
observables. We update the LHC and Tevatron constraints on CP-conserving
two-Higgs-doublet models without tree-level flavour-changing neutral currents.
While the relative sign between the top Yukawa and the gauge coupling of the
126 GeV Higgs is found be the same as in the SM, at 90% CL, there is a sign
degeneracy in the determination of its bottom and tau Yukawa couplings. This
results in several disjoint allowed regions in the parameter space. We show how
generic sum rules governing the scalar couplings determine the properties of
the additional Higgs bosons in the different allowed regions. The role of
electroweak precision observables, low-energy flavour constraints and LHC
searches for additional scalars to further restrict the available parameter
space is also discussed.


title:
Densities and Eccentricities of 139 Kepler Planets from Transit Time
  Variations

abstract:
  We extract densities and eccentricities of 139 sub-Jovian planets by
analyzing transit time variations (TTVs) obtained by the Kepler mission through
Quarter 12. We partially circumvent the degeneracies that plague TTV inversion
with the help of an analytical formula for the TTV. From the observed TTV
phases, we find that most of these planets have eccentricities of order a few
percent. More precisely, the r.m.s. eccentricity is 0.018^{+0.005}_{-0.004},
and planets smaller than 2.5R_\earth are around twice as eccentric as those
bigger than 2.5R_\earth. We also find a best-fit density-radius relationship
\rho ~3 g/cm^3 \times (R/3R_\earth)^{-2.3} for the 56 planets that likely have
small eccentricity and hence small statistical correction to their masses. Many
planets larger than 2.5R_\earth are less dense than water, implying that their
radii are largely set by a massive hydrogen atmosphere.


title:
Supersymmetric gauge theory, (2,0) theory and twisted 5d
  Super-Yang-Mills

abstract:
  Twisted compactification of the 6d N=(2,0) theories on a punctured Riemann
surface give a large class of 4d N=1 and N=2 gauge theories, called class S. We
argue that nonperturbative dynamics of class S theories are described by 5d
maximal Super-Yang-Mills (SYM) twisted on the Riemann surface. In a sense,
twisted 5d SYM might be regarded as a "Lagrangian" for class S theories on
R^{1,2} times S^1. First, we show that twisted 5d SYM gives generalized
Hitchin's equations which was proposed recently. Then, we discuss how to
identify chiral operators with quantities in twisted 5d SYM. Mesons, or
holomorphic moment maps, are identified with operators at punctures which are
realized as 3d superconformal theories T_rho[G] coupled to twisted 5d SYM.
"Baryons" are identified qualitatively through a study of 4d N=2 Higgs
branches. We also derive a simple formula for dynamical superpotential vev
which is relevant for BPS domain wall tensions. With these tools, we examine
many examples of 4d N=1 theories with several phases such as confining, Higgs,
and Coulomb phases, and show perfect agreements between field theories and
twisted 5d SYM. Spectral curve is an essential tool to solve generalized
Hitchin's equations, and our results clarify the physical information encoded
in the curve.


title:
Radiative Feedback from high mass X-ray binaries on the formation of the
  first galaxies and early reionization

abstract:
  Recent work suggests that the first generation of stars, the so-called
Population III (Pop III), could have formed primarily in binaries or as members
of small multiple systems. Here we investigate the impact of X-ray feedback
from High-Mass X-ray Binaries (HMXBs) left behind in stellar binary systems
after the primary forms a black hole (BH), accreting gas at a high rate from
the companion, a process that is thought to be favored at the low metallicities
characteristic of high-redshift gas. Thanks to their large mean free path,
X-rays are capable of preionizing and preheating the gas in the intergalactic
medium (IGM) and in haloes long before the reionization of the Universe is
complete, and thus could have strongly affected the formation of subsequent
generations of stars as well as reionization. We have carried out zoomed
hydrodynamical cosmological simulations of minihaloes, accounting for the
formation of Pop III stars and their collapse into BHs and HMXBs, and the
associated radiation-hydrodynamic feedback from UV and X-ray photons. We find
no strong net feedback from HMXBs on the simulated star formation history. On
the other hand, the preheating of the IGM by HMXBs leads to a strong
suppression of small-scale structures and significantly lowers the
recombination rate in the IGM, thus yielding a net positive feedback on
reionization. We further show that X-ray feedback from HMXBs can augment the
ionizing feedback from the Pop III progenitor stars to suppress gas accretion
onto the first BHs, limiting their growth into supermassive BHs. Finally, we
show that X-ray ionization by HMXBs leaves distinct signatures in the
properties of the high-redshift hydrogen that may be probed in upcoming
observations of the redshifted 21cm spin-flip line.


title: Direct Detection Portals for Self-interacting Dark Matter

abstract:
  Dark matter self-interactions can affect the small scale structure of the
Universe, reducing the central densities of dwarfs and low surface brightness
galaxies in accord with observations. From a particle physics point of view,
this points toward the existence of a 1-100 MeV particle in the dark sector
that mediates self-interactions. Since mediator particles will generically
couple to the Standard Model, direct detection experiments provide sensitive
probes of self-interacting dark matter. We consider three minimal mechanisms
for coupling the dark and visible sectors: photon kinetic mixing, Z boson mass
mixing, and the Higgs portal. Self-interacting dark matter motivates a new
benchmark paradigm for direct detection via momentum-dependent interactions,
and ton-scale experiments will cover astrophysically motivated parameter
regimes that are unconstrained by current limits. Direct detection is a
complementary avenue to constrain velocity-dependent self-interactions that
evade astrophysical bounds from larger scales, such as those from the Bullet
Cluster.


title: Measuring topological invariants in photonic systems

abstract:
  Motivated by the recent theoretical and experimental progress in implementing
topological orders with photons, we analyze photonic systems with different
topologies and present a scheme to probe their topological features.
Specifically, we propose a scheme to modify the boundary phases to manipulate
edge state dynamics. Such a scheme allows one to measure the winding number of
the edge states. Furthermore, we discuss the effect of loss and disorder on the
validity of our approach.


title:
A heat flow approach to Onsager's conjecture for the Euler equations on
  manifolds

abstract:
  We give a simple proof of Onsager's conjecture concerning energy conservation
for weak solutions to the Euler equations on any compact Riemannian manifold,
extending the results of Constantin-E-Titi and
Cheskidov-Constantin-Friedlander-Shvydkoy in the flat case. When restricted to
$\mathbb{T}^{d}$ or $\mathbb{R}^{d}$, our approach yields an alternative proof
of the sharp result of the latter authors.
  Our method builds on a systematic use of a smoothing operator defined via a
geometric heat flow, which was considered by Milgram-Rosenbloom as a means to
establish the Hodge theorem. In particular, we present a simple and geometric
way to prove the key nonlinear commutator estimate, whose proof previously
relied on a delicate use of convolutions.


title:
A uniform metal distribution in the intergalactic medium of the Perseus
  cluster of galaxies

abstract:
  Most of the metals (elements heavier than helium) ever produced by stars in
the member galaxies of galaxy clusters currently reside within the hot, X-ray
emitting intra-cluster gas. Observations of X-ray line emission from this
intergalactic medium have suggested a relatively small cluster-to-cluster
scatter outside of the cluster centers and enrichment with iron out to large
radii, leading to the idea that the metal enrichment occurred early in the
history of the Universe. Models with early enrichment predict a uniform metal
distribution at large radii in clusters, while late-time enrichment, favored by
some previous studies, is expected to introduce significant spatial variations
of the metallicity. To discriminate clearly between these competing models, it
is essential to test for potential inhomogeneities by measuring the abundances
out to large radii along multiple directions in clusters, which has not
hitherto been done. Here we report a remarkably uniform measured iron
abundance, as a function of radius and azimuth, that is statistically
consistent with a constant value of 0.306+/-0.012 Solar out to the edge of the
nearby Perseus Cluster. This homogeneous distribution requires that most of the
metal enrichment of the intergalactic medium occurred before the cluster
formed, likely over 10 billion years ago, during the period of maximal star
formation and black hole activity.


title:
Template Banks for Binary black hole searches with Numerical Relativity
  waveforms

abstract:
  Gravitational waves (GW) from coalescing stellar-mass black hole binaries
(BBH) are expected to be detected by the Advanced Laser Interferometer
Gravitational-wave Observatory and Advanced Virgo. Detection searches operate
by matched-filtering the detector data using a bank of waveform templates.
Traditionally, template banks for BBH are constructed from intermediary
analytical waveform models which are calibrated against numerical relativity
simulations and which can be aluated for any choice of BBH parameters. This
paper explores an alternative to the traditional approach, namely the
construction of template banks directly from numerical BBH simulations. Using
non-spinning BBH systems as an example, we demonstrate which regions of the
mass-parameter plane can be covered with existing numerical BBH waveforms. We
estimate the required number and required length of BBH simulations to cover
the entire non-spinning BBH parameter plane up to mass-ratio 10, thus
illustrating that our approach can be used to guide parameter placement of
future numerical simulations. We derive error bounds which are independent of
analytical waveform models; therefore, our formalism can be used to
independently test the accuracy of such waveform models. The resulting template
banks are suitable for advanced LIGO searches.


title:
Technical Report: Distribution Temporal Logic: Combining Correctness
  with Quality of Estimation

abstract:
  We present a new temporal logic called Distribution Temporal Logic (DTL)
defined over predicates of belief states and hidden states of partially
observable systems. DTL can express properties involving uncertainty and
likelihood that cannot be described by existing logics. A co-safe formulation
of DTL is defined and algorithmic procedures are given for monitoring
executions of a partially observable Markov decision process with respect to
such formulae. A simulation case study of a rescue robotics application
outlines our approach.


title: IRM4MLS: the influence reaction model for multi-level simulation

abstract:
  In this paper, a meta-model called IRM4MLS, that aims to be a generic ground
to specify and execute multi-level agent-based models is presented. It relies
on the influence/reaction principle and more specifically on IRM4S. Simulation
models for IRM4MLS are defined. The capabilities and possible extensions of the
meta-model are discussed.


title: A Spitzer Search for Transits of Radial Velocity Detected Super-Earths

abstract:
  Unlike hot Jupiters or other gas giants, super-Earths are expected to have a
wide variety of compositions, ranging from terrestrial bodies like our own to
more gaseous planets like Neptune. Observations of transiting systems, which
allow us to directly measure planet masses and radii and constrain atmospheric
properties, are key to understanding the compositional diversity of the planets
in this mass range. Although Kepler has discovered hundreds of transiting
super-Earth candidates over the past four years, the majority of these planets
orbit stars that are too far away and too faint to allow for detailed
atmospheric characterization and reliable mass estimates. Ground-based transit
surveys focus on much brighter stars, but most lack the sensitivity to detect
planets in this size range. One way to get around the difficulty of finding
these smaller planets in transit is to start by choosing targets that are
already known to contain super-Earth sized bodies detected using the radial
velocity technique. Here we present results from a Spitzer program to observe
six of the most favorable RV detected super-Earth systems, including HD 1461,
HD 7924, HD 156668, HIP 57274, and GJ 876. We find no evidence for transits in
any of their 4.5 micron flux light curves, and place limits on the allowed
transit depths and corresponding planet radii that rule out even the most dense
and iron-rich compositions for these objects. We also observed HD 97658, but
the observation window was based on a possible ground-based transit detection
(Henry et al. 2011) that was later ruled out; thus the window did not include
the predicted time for the transit detection recently made by MOST (Dragomir et
al. 2013).


title: Search for CP violation in the decay $D^+ \to \pi^-\pi^+\pi^+$

abstract:
  A search for CP violation in the phase space of the decay
$D^+\to\pi^-\pi^+\pi^+$ is reported using $pp$ collision data, corresponding to
an integrated luminosity of 1.0 fb$^{-1}$, collected by the LHCb experiment at
a centre-of-mass energy of 7 TeV. The Dalitz plot distributions for $3.1\times
10^6$ $D^+$ and $D^-$ candidates are compared with binned and unbinned
model-independent techniques. No evidence for CP violation is found.


title: Quantum hedging in two-round prover-verifier interactions

abstract:
  We consider the problem of a particular kind of quantum correlation that
arises in some two-party games. In these games, one player is presented with a
question they must answer, yielding an outcome of either 'win' or 'lose'.
Molina and Watrous (arXiv:1104.1140) studied such a game that exhibited a
perfect form of hedging, where the risk of losing a first game can completely
offset the corresponding risk for a second game. This is a non-classical
quantum phenomenon, and establishes the impossibility of performing strong
error-reduction for quantum interactive proof systems by parallel repetition,
unlike for classical interactive proof systems. We take a step in this article
towards a better understanding of the hedging phenomenon by giving a complete
characterization of when perfect hedging is possible for a natural
generalization of the game in arXiv:1104.1140. Exploring in a different
direction the subject of quantum hedging, and motivated by implementation
concerns regarding loss-tolerance, we also consider a variation of the protocol
where the player who receives the question can choose to restart the game
rather than return an answer. We show that in this setting there is no possible
hedging for any game played with state spaces corresponding to
finite-dimensional complex Euclidean spaces.


title:
Epigenetic regulation of repetitive DNA through mitotic asynchrony
  following double fertilization in angiosperms

abstract:
  Several recent studies show that companion cells in flowering plant
gametophytes relax epigenetic control of transposable elements (TEs) to promote
production of small RNA that presumably assist nearby reproductive cells in
management of TEs. In light of this possibility, a closer look at the timing of
cell division in relation to angiosperm double fertilization is warranted. From
such an analysis, it is conceivable that double fertilization can drive
angiosperm evolution by facilitating crosses between genetically diverse
parents. A key feature of this ability is the order of cell division following
double fertilization, since division of the primary endosperm nucleus prior to
the zygote would produce small RNA capable of identifying TEs and defining
chromatin states in the zygote prior to its entry into S-phase of the cell
cycle. Consequently, crosses leading to increased ploidy or between genetically
diverse parents would yield offspring better capable of managing a diverse
complement of TEs and repetitive DNA. Considering double fertilization in this
regard challenges previous notions that the primary purpose of endosperm is for
improved seed reserve storage and utilization.


title: Two photon quantum interference in plasmonics - Theory and Applications

abstract:
  We report perfect two photon quantum interference with near-unity visibility
in a resonant tunneling plasmonic structure in folded Kretschmann geometry.
This is despite absorption-induced loss of unitarity in plasmonic systems. The
effect is traced to perfect destructive interference between the squares of
amplitude reflection and transmission coefficients. We further highlight yet
another remarkable potential of coincidence measurements as a probe with better
resolution as compared to standard spectroscopic techniques. The finer features
show up in both angle resolved and frequency resolved studies.


title: A Random Walk Model for Item Recommendation in Folksonomies

abstract:
  Social tagging, as a novel approach to information organization and
discovery, has been widely adopted in many Web2.0 applications. The tags
provide a new type of information that can be exploited by recommender systems.
Nevertheless, the sparsity of ternary <user, tag, item> interaction data limits
the performance of tag-based collaborative filtering. This paper proposes a
random-walk-based algorithm to deal with the sparsity problem in social tagging
data, which captures the potential transitive associations between users and
items through their interaction with tags. In particular, two smoothing
strategies are presented from both the user-centric and item-centric
perspectives. Experiments on real-world data sets empirically demonstrate the
efficacy of the proposed algorithm.


title:
Measurement of the radial matrix elements of the $6s \: ^2S_{1/2}
  \rightarrow 7p \: ^2P_{J} $ transitions in atomic cesium

abstract:
  We report measurements of the absorption strength of the cesium $6s \:
^2S_{1/2} \rightarrow 7p \: ^2P_{3/2} $ and the $6s \: ^2S_{1/2} \rightarrow 7p
\: ^2P_{1/2} $ transitions at $\lambda = 456$ nm and 459 nm, respectively, in
an atomic vapor cell. By simultaneously measuring the absorption strength on
the Cs D$_1$ line ($6s \: ^2S_{1/2} \rightarrow 6p \: ^2P_{1/2} $), for which
the electric dipole transition moment is precisely known, we are able to
determine the reduced dipole matrix elements for these two lines. We report
$\langle 7P_{3/2} || r || 6S_{1/2} \rangle = 0.5780 \: (7) \: a_0$ and $\langle
7P_{1/2} || r || 6S_{1/2} \rangle = 0.2789 \: (16) \: a_0$, with fractional
uncertainties of 0.12% and 0.6%, respectively. Through these measurements, we
can reduce the discrepancy between values of the tensor polarizability for the
Cs $6s \: ^2S_{1/2} \rightarrow 7s \: ^2S_{1/2} $ transition that have been
determined through two different methods.


title:
Quantum simulation of correlated-hopping models with fermions in optical
  lattices

abstract:
  By using a modulated magnetic field in a Feshbach resonance for ultracold
fermionic atoms in optical lattices, we show that it is possible to engineer a
class of models usually referred to as correlated-hopping models. These models
differ from the Hubbard model in exhibiting additional density-dependent
interaction terms that affect the hopping processes. In addition to the
spin-SU(2) symmetry, they also possess a charge-SU(2) symmetry, which opens the
possibility of investigating the $\eta$-pairing mechanism for superconductivity
introduced by Yang for the Hubbard model. We discuss the known solution of the
model in 1D (where $\eta$ states have been found in the degenerate manifold of
the ground state) and show that, away from the integrable point, quantum Monte
Carlo simulations at half filling predict the emergence of a phase with
coexisting incommensurate spin and charge order.


title: The Highest Redshift Quasar at $z=7.085$: A Radio Quiet Source

abstract:
  We present 1-2 GHz Very Large Array A-configuration continuum observations on
the highest redshift quasar known to date, the $z=7.085$ quasar ULAS
J112001.48+064124.3. The results show no radio continuum emission at the
optical position of the quasar or its vicinity at a level of $\geq 3\sigma$ or
$23.1 \mu$Jy beam$^{-1}$. This $3\sigma$ limit corresponds to a rest frame 1.4
GHz luminosity density limit of $L_{\nu,1.4\,GHz} < 1.76 \times 10^{24}$ W
Hz$^{-1}$ for a spectral index of $\alpha=0$, and $L_{\nu,1.4\,GHz} < 1.42
\times 10^{25}$ W Hz$^{-1}$ for a spectral index of $\alpha=-1$. The rest-frame
1.4 GHz luminosity limits are $L_{rad} < 6.43 \times 10^6 L_{\odot}$ and
$L_{\rm rad} < 5.20 \times 10^7 L_{\odot}$ for $\alpha=0$ and $\alpha=-1$,
respectively. The derived limits for the ratio of the rest frame 1.4 GHz
luminosity density to the $B$-band optical luminosity density are
$R\rlap{}_{1.4}^{*} < 0.53$ and $< 4.30$ for the above noted spectral indices,
respectively. Given our upper limits on the radio continuum emission and the
radio-to-optical luminosity ratio, we conclude that this quasar is radio-quiet
and located at the low end of the radio quiet distribution of high redshift ($z
\gtrsim 6$) quasars.


title:
Evaluation the efficiency of artificial bee colony and the firefly
  algorithm in solving the continuous optimization problem

abstract:
  Now the Meta-Heuristic algorithms have been used vastly in solving the
problem of continuous optimization. In this paper the Artificial Bee Colony
(ABC) algorithm and the Firefly Algorithm (FA) are valuated. And for presenting
the efficiency of the algorithms and also for more analysis of them, the
continuous optimization problems which are of the type of the problems of vast
limit of answer and the close optimized points are tested. So, in this paper
the efficiency of the ABC algorithm and FA are presented for solving the
continuous optimization problems and also the said algorithms are studied from
the accuracy in reaching the optimized solution and the resulting time and the
reliability of the optimized answer points of view.


title: E-Business Implications for Productivity and Competitiveness

abstract:
  Information and Communication Technology (ICT) affects to a great extent the
output and productivity growth. Evidence suggests that investment growth in ICT
has rapidly accelerated the TFP (total factor productivity) growth within the
European Union. Such progress is particularly essential for the sectors which
themselves produce new technology, but it is dispersing to other sectors, as
well. Nevertheless, decrease in ICT investment does not necessarily decline the
ICT contribution to output and productivity growth. These variations come out
from the problems related to the particular phenomenon proper assessment, but
predominantly from the companies' special requirements, as well as the
necessary adjustments of labour employed. Hence, this paper aims at estimating
the huge distinction in terms of ICT and TFB contributions to labour
productivity growth among some of the European member states, as well as the
factors which might stand behind the particular findings.


title: Average size of 2-Selmer groups of elliptic curves over function fields

abstract:
  Employing a geometric setting inspired by the proof of the Fundamental Lemma,
we study some counting problems related to the average size of 2-Selmer groups
and hence obtain an estimate for it.


title: Approximability of the upper chromatic number of hypergraphs

abstract:
  A C-coloring of a hypergraph ${\cal H}=(X,{\cal E})$ is a vertex coloring
$\varphi: X\to {\mathbb{N}}$ such that each edge $E\in{\cal E}$ has at least
two vertices with a common color. The related parameter $\overline{\chi}({\cal
H})$, called the upper chromatic number of ${\cal H}$, is the maximum number of
colors can be used in a C-coloring of ${\cal H}$. A hypertree is a hypergraph
which has a host tree $T$ such that each edge $E\in {\cal E}$ induces a
connected subgraph in $T$. Notations $n$ and $m$ stand for the number of
vertices and edges, respectively, in a generic input hypergraph.
  We establish guaranteed polynomial-time approximation ratios for the
difference $n-\overline{\chi}({\cal H})$, which is $2+2 \ln (2m)$ on
hypergraphs in general, and $1+ \ln m$ on hypertrees. The latter ratio is
essentially tight as we show that $n-\overline{\chi}({\cal H})$ cannot be
approximated within $(1-\epsilon) \ln m$ on hypertrees (unless ${\sf NP}
\subseteq {\sf DTIME} (n^{{\cal O}(log\;log\; n)})$). Furthermore,
$\overline{\chi}({\cal H})$ does not have ${\cal
O}(n^{1-\epsilon})$-approximation and cannot be approximated within additive
error $o(n)$ on the class of hypertrees (unless ${\sf P}={\sf NP}$).


title:
Smartphone as a Personal, Pervasive Health Informatics Services
  Platform: Literature Review

abstract:
  Objectives: The article provides an overview of current trends in personal
sensor, signal and imaging informatics, that are based on emerging mobile
computing and communications technologies enclosed in a smartphone and enabling
the provision of personal, pervasive health informatics services.
  Methods: The article reviews examples of these trends from the PubMed and
Google scholar literature search engines, which, by no means claim to be
complete, as the field is evolving and some recent advances may not be
documented yet.
  Results: There exist critical technological advances in the surveyed
smartphone technologies, employed in provision and improvement of diagnosis,
acute and chronic treatment and rehabilitation health services, as well as in
education and training of healthcare practitioners. However, the most emerging
trend relates to a routine application of these technologies in a
prevention/wellness sector, helping its users in self-care to stay healthy.
  Conclusions: Smartphone-based personal health informatics services exist, but
still have a long way to go to become an everyday, personalized
healthcare-provisioning tool in the medical field and in a clinical practice.
Key main challenge for their widespread adoption involve lack of user
acceptance striving from variable credibility and reliability of applications
and solutions as they a) lack evidence-based approach; b) have low levels of
medical professional involvement in their design and content; c) are provided
in an unreliable way, influencing negatively its usability; and, in some cases,
d) being industry-driven, hence exposing bias in information provided, for
example towards particular types of treatment or intervention procedures.


title: Thin Film Substrates from the Raman spectroscopy point of view

abstract:
  We have investigated ten standard single crystal substrates of complex oxides
on the account of their applicability in the Raman spectroscopy based thin film
research. In this study we suggest a spectra normalization procedure that
utilizes a comparison of the substrate Raman spectra to those of
well-established Raman reference materials. We demonstrate that MgO, LaGaO3,
(LaAlO3)_0.3(Sr2AlTaO6)_0.7 (LSAT), DyScO3, YAlO3, and LaAlO3 can be of
potential use for a Raman based thin film research. At the same time TiO2
(rutile), NdGaO3, SrLaAlO4, and SrTiO3 single crystals exhibit multiple phonon
modes accompanied by strong Raman background that substantially hinder the
Raman based thin film experiments.


title:
Hadamard Type Asymptotics for Eigenvalues of the Neumann Problem for
  Elliptic Operators

abstract:
  This paper considers how the eigenvalues of the Neumann problem for an
elliptic operator depend on the domain. The proximity of two domains is
measured in terms of the norm of the difference between the two resolvents
corresponding to the reference domain and the perturbed domain, and the size of
eigenfunctions outside the intersection of the two domains. This construction
enables the possibility of comparing both nonsmooth domains and domains with
different topology. An abstract framework is presented, where the main result
is an asymptotic formula where the remainder is expressed in terms of the
proximity quantity described above when this is relatively small. We consider
two applications: the Laplacian in both $C^{1,\alpha}$ and Lipschitz domains.
For the $C^{1,\alpha}$ case, an asymptotic result for the eigenvalues is given
together with estimates for the remainder, and we also provide an example which
demonstrates the sharpness of our obtained result. For the Lipschitz case, the
proximity of eigenvalues is estimated.


title: Word calculus in the fundamental group of the Menger curve

abstract:
  The fundamental group of the Menger universal curve is uncountable and not
free, although all of its finitely generated subgroups are free. It contains an
isomorphic copy of the fundamental group of every one-dimensional separable
metric space and an isomorphic copy of the fundamental group of every planar
Peano continuum. We give an explicit and systematic combinatorial description
of the fundamental group of the Menger universal curve and its generalized
Cayley graph in terms of word sequences. The word calculus, which requires only
two letters and their inverses, is based on Pasynkov's partial topological
product representation and can be expressed in terms of a variation on the
classical puzzle known as the Towers of Hanoi.


title:
Derivation of 12- and 14-band $\textbf{k}\cdot\textbf{p}$ Hamiltonians
  for dilute bismide and bismide-nitride semiconductors

abstract:
  Using an $sp^{3}s^{*}$ tight-binding model we demonstrate how the observed
strong bowing of the band gap and spin-orbit-splitting with increasing Bi
composition in the dilute bismide alloy GaBi$_{x}$As$_{1-x}$ can be described
in terms of a band-anticrossing interaction between the extended states of the
GaAs valence band edge and highly localised Bi-related resonant states lying
below the GaAs valence band edge. We derive a 12-band
$\textbf{k}\cdot\textbf{p}$ Hamiltonian to describe the band structure of
GaBi$_{x}$As$_{1-x}$ and show that this model is in excellent agreement with
full tight-binding calculations of the band structure in the vicinity of the
band edges, as well as with experimental measurements of the band gap and
spin-orbit-splitting across a large composition range. Based on a tight-binding
model of GaBi$_{x}$N$_{y}$As$_{1-x-y}$ we show that to a good approximation N
and Bi act independently of one another in disordered
GaBi$_{x}$N$_{y}$As$_{1-x-y}$ alloys, indicating that a simple description of
the band structure is possible. We present a 14-band
$\textbf{k}\cdot\textbf{p}$ Hamiltonian for ordered
GaBi$_{x}$N$_{y}$As$_{1-x-y}$ crystals which reproduces accurately the
essential features of full tight-binding calculations of the band structure in
the vicinity of the band edges. The $\textbf{k}\cdot\textbf{p}$ models we
present here are therefore ideally suited to the simulation of the
optoelectronic properties of these novel III-V semiconductor alloys.


title: Topologically Universal Spectral Hierarchies of Quasiperiodic Systems

abstract:
  Topological properties of energy spectra of general one-dimensional
quasiperiodic systems, describing also Bloch electrons in magnetic fields, are
studied for an infinity of irrational modulation frequencies corresponding to
irrational numbers of flux quanta per unit cell. These frequencies include
well-known ones considered in works on Fibonacci quasicrystals. It is shown
that the spectrum for any such frequency exhibits a self-similar hierarchy of
clusters characterized by universal (system-independent) values of Chern
topological integers which are exactly determined. The cluster hierarchy
provides a simple and systematic organization of all the spectral gaps, labeled
by universal topological numbers which are exactly determinable, thus avoiding
their numerical evaluation using rational approximants of the irrational
frequency. These numbers give both the quantum Hall conductance of the system
and the winding number of the edge-state energy traversing a gap as a Bloch
quasimomentum is varied.

categories: cond-mat.mes-hall cond-mat.other cond-mat.str-el quant-ph


title:
Simple analytical approximations for treatment of inverse Compton
  scattering of relativistic electrons in the black-body radiation field

abstract:
  The inverse Compton (IC) scattering of relativistic electrons is one of the
major gamma-ray production mechanisms in different environments. Often the
target photons for the IC scattering are dominated by black (or grey) body
radiation. In this case, the precise treatment of the characteristics of IC
radiation requires numerical integrations over the Planckian distribution.
Formally, analytical integrations are also possible but they result in series
of several special functions; this limits the efficiency of usage of these
expressions. The aim of this work is the derivation of approximate analytical
presentations which would provide adequate accuracy for the calculations of the
energy spectra of up-scattered radiation, the rate of electron energy losses,
and the mean energy of emitted photons. Such formulae have been obtained by
merging the analytical asymptotic limits. The coefficients in these expressions
are calculated via the least square fitting of the results of numerical
integrations. The simple analytical presentations, obtained for both the
isotropic and anisotropic target radiation fields, provide adequate (as good as
$1\%$) accuracy for broad astrophysical applications.


title:
High spectral resolution spectroscopy of the SiO fundamental lines in
  red giants and red supergiants with VLT/VISIR

abstract:
  We present high spectral resolution (R = 30000) spectroscopic observations of
the SiO fundamental lines near 8.1 micron in 16 bright red giants and red
supergiants using VLT/VISIR. Our sample consists of seven normal K--M giants,
three Mira stars, three optically bright red supergiants, two dusty red
supergiants, and the enigmatic object GCIRS3 near the Galactic center. We
detected SiO fundamental lines in all of our program stars except for GCIRS3.
The SiO lines in normal K and M giants as well as optically bright red
supergiants do not show P-Cyg profiles or blueshifts, which means the absence
of systematic outflows in the SiO line forming region. On the other hand, we
detected P-Cyg profiles in the SiO lines in the dusty red supergiants VY CMa
and VX Sgr (with the latter being a new detection), which suggest outflow
velocities of 27 and 17 km/s, respectively. We derived basic stellar parameters
(effective temperature, surface gravity, luminosity, and mass) for the normal
K--M giants and optically bright red supergiants in our sample and compared the
observed VISIR spectra with synthetic spectra predicted from MARCS photospheric
models. Most of the SiO lines observed in the program stars warmer than ~3400 K
are reasonably reproduced by the MARCS models, which allowed us to estimate the
silicon abundance as well as the 28Si/29Si and 28Si/30Si ratios. However, we
detected possible absorption excess in some SiO lines. Moreover, the SiO lines
in the cooler red giants and red supergiant cannot be explained by the MARCS
models at all even if the dust emission is taken into account. This
disagreement may be a signature of the dense, extended molecular outer
atmosphere.


title:
Cavity method for force transmission in jammed disordered packings of
  hard particles

abstract:
  The force distribution of jammed disordered packings has always been
considered a central object in the physics of granular materials. However, many
of its features are poorly understood. In particular, analytic relations to
other key macroscopic properties of jammed matter, such as the contact network
and its coordination number, are still lacking. Here we develop a mean-field
theory for this problem, based on the consideration of the contact network as a
random graph where the force transmission becomes a constraint optimization
problem. We can thus use the cavity method developed in the last decades within
the statistical physics of spin glasses and hard computer science problems.
This method allows us to compute the force distribution $\text P(f)$ for random
packings of hard particles of any shape, with or without friction. We find a
new signature of jamming in the small force behavior $\text P(f) \sim
f^{\theta}$, whose exponent has attracted recent active interest: we find a
finite value for $\text P(f=0)$, along with $\theta=0$. Furthermore, we relate
the force distribution to a lower bound of the average coordination number $\,
{\bar z}_{\rm c}^{\rm min}(\mu)$ of jammed packings of frictional spheres with
coefficient $\mu$. This bridges the gap between the two known isostatic limits
$\, {\bar z}_{\rm c}(\mu=0)=2D$ (in dimension $D$) and $\, {\bar z}_{\rm c}(\mu
\to \infty)=D+1$ by extending the naive Maxwell's counting argument to
frictional spheres. The theoretical framework describes different types of
systems, such as non-spherical objects in arbitrary dimensions, providing a
common mean-field scenario to investigate force transmission, contact networks
and coordination numbers of jammed disordered packings.


title:
Recent results of high-energy spin phenomena of gluons and sea-quarks in
  polarized proton-proton collisions at RHIC at BNL

abstract:
  The STAR experiment at the Relativistic Heavy-Ion Collider at Brookhaven
National Laboratory is carrying out a spin physics program in high-energy
polarized proton collisions at $\sqrt{s}=200\,$GeV and $\sqrt{s}=500\,$GeV to
gain a deeper insight into the spin structure and dynamics of the proton.
  One of the main objectives of the spin physics program at RHIC is the precise
determination of the polarized gluon distribution function. The STAR detector
is well suited for the reconstruction of various final states involving jets,
$\pi^{0}$, $\pi^{\pm}$, e$^{\pm}$ and $\gamma$, which allows to measure several
different processes. Recent results suggest a gluon spin contribution to the
proton spin at the same level as the quark spin contribution itself.
  The production of $W$ bosons in polarized p+p collisions at
$\sqrt{s}=500\,$GeV opens a new era in the study of the spin-flavor structure
of the proton. $W^{-(+)}$ bosons are produced in $\bar{u}+d\;(\bar{d}+u)$
collisions and can be detected through their leptonic decays,
$e^{-}+\bar{\nu}_{e}\;(e^{+}+\nu_{e})$, where only the respective charged
lepton is measured. Results of $W^{-(+)}$ production suggest a large asymmetry
between the polarization of anti-$u$ and anti-$d$ quarks.