title:
Transmission and reflection characteristics of metal-coated optical
  fiber tip pairs

abstract:
  The optical transmission and reflection in between two metalized optical
fiber tips is studied in the optical near-field and far-field domains. Besides
aluminum-coated tips for near-field scanning optical microscopy (NSOM),
specifically developed gold-coated fiber tips cut by focused ion beam (FIB) are
investigated. Transverse transmission maps of sub-wavelength width clearly
evidence optical near-field coupling between the tips for short tip distances
and becomes essentially Gaussian-shaped for larger distances in the far-field
regime. Moreover concentric reflection fringes observed for NSOM-type tips
illustrate the influence of the receiving fiber tip on the emission pattern of
the source tip.


title:
High-energy particle transport in 3D hydrodynamic models of
  colliding-wind binaries

abstract:
  Massive stars in binary systems (as WR140, WR147 or $\eta$ Carinae) have long
been regarded as potential sources of high-energy $\gamma$-rays. The emission
is thought to arise in the region where the stellar winds collide and produce
relativistic particles which subsequently might be able to emit $\gamma$-rays.
Detailed numerical hydrodynamic simulations have already offered insight in the
complex dynamics of the wind collision region (WCR), while independent
analytical studies, albeit with simplified descriptions of the WCR, have shed
light on the spectra of charged particles. In this paper, we describe a
combination of these two approaches. We present a 3D-hydrodynamical model for
colliding stellar winds and compute spectral energy distributions of
relativistic particles for the resulting structure of the WCR. The hydrodynamic
part of our model incorporates the line-driven acceleration of the winds,
gravity, orbital motion and the radiative cooling of the shocked plasma. In our
treatment of charged particles we consider diffusive shock acceleration in the
WCR and the subsequent cooling via inverse Compton losses (including
Klein-Nishina effects), bremsstrahlung, collisions and other energy loss
mechanisms.


title: Limits on core driven ILOT outbursts of asymptotic giant branch stars

abstract:
  We find that single-star mechanisms for Intermediate Luminosity Optical
Transients (ILOTs; Red Transients; Red Novae) which are powered by energy
release in the core of asymptotic giant branch (AGB) stars are likely to eject
the entire envelope, and hence cannot explain ILOTs in AGB and similar stars.
There are single-star and binary models for the powering of ILOTs, which are
eruptive stars with peak luminosities between those of novae and supernovae. In
single-star models the ejection of gas at velocities of ~500-1000 km/s and a
possible bright ionizing flash, require a shock to propagate from the core
outward. Using a self similar solution to follow the propagation of the shock
through the envelope of two evolved stellar models, a 6Mo AGB star and an 11Mo
yellow supergiant (YSG) star, we find that the shock that is required to
explain the observed mass loss also ejects most of the envelope. We also show
that for the event to have a strong ionizing flash the required energy expels
most of the envelope. The removal of most of the envelope is in contradiction
with observations. We conclude that single-star models for ILOTs of evolved
giant stars encounter severe difficulties.


title:
Phonon-assisted optical excitation in the narrow bandgap Mott insulator
  Sr3Ir2O7

abstract:
  We examined the temperature (T) evolution of the optical conductivity spectra
of Sr$_3$Ir$_2$O$_7$ over a wide range of 10-400 K. The system was barely
insulating, exhibiting a small indirect bandgap of $\sim$0.1 eV. The low-energy
features of the optical d-d excitation (${\hbar}{\omega}$ $<$ 0.3 eV) evolved
drastically, whereas such evolution was not observed for the O K-edge X-ray
absorption spectra. This suggests that the T evolution in optical spectra is
not caused by a change in the bare (undressed) electronic structure, but
instead, presumably originates from an abundance of phonon-assisted indirect
excitations. Our results showed that the low-energy excitations were dominated
by phonon-absorption processes which involve, in particular, the optical
phonons. This implies that phonon-assisted processes significantly facilitate
the charge dynamics in barely insulating Sr$_3$Ir$_2$O$_7$.


title:
Transparent Combination of Expert and Measurement Data for Defect
  Prediction: An Industrial Case Study

abstract:
  Defining strategies on how to perform quality assurance (QA) and how to
control such activities is a challenging task for organizations developing or
maintaining software and software-intensive systems. Planning and adjusting QA
activities could benefit from accurate estimations of the expected defect
content of relevant artifacts and the effectiveness of important quality
assurance activities. Combining expert opinion with commonly available
measurement data in a hybrid way promises to overcome the weaknesses of purely
data-driven or purely expert-based estimation methods. This article presents a
case study of the hybrid estimation method HyDEEP for estimating defect content
and QA effectiveness in the telecommunication domain. The specific focus of
this case study is the use of the method for gaining quantitative predictions.
This aspect has not been empirically analyzed in previous work. Among other
things, the results show that for defect content estimation, the method
performs significantly better statistically than purely data-based methods,
with a relative error of 0.3 on average (MMRE).


title: The hidden symmetry and Mr. Higgs!

abstract:
  Written in non-technical language, this review article explains the
significance of the Higgs field and the associated Higgs boson in High-Energy
Physics. The connection of symmetry with particle interactions and their
unification is also discussed in this context. The presentation is informal and
physical concepts are demonstrated through metaphors from everyday experience.


title: Possible antigravity regions in $F(R)$ theory?

abstract:
  We construct an $F(R)$ gravity theory corresponding to the Weyl invariant two
scalar field theory. We investigate whether such $F(R)$ gravity can have the
antigravity regions where the Weyl curvature invariant does not diverge at the
Big Bang and Big Crunch singularities. It is revealed that the divergence
cannot be evaded completely but can be much milder than that in the original
Weyl invariant two scalar field theory.


title:
Ends, fundamental tones, and capacities of minimal submanifolds via
  extrinsic comparison theory

abstract:
  We study the volume of extrinsic balls and the capacity of extrinsic annuli
in minimal submanifolds which are properly immersed with controlled radial
sectional curvatures into an ambient manifold with a pole. The key results are
concerned with the comparison of those volumes and capacities with the
corresponding entities in a rotationally symmetric model manifold. Using the
asymptotic behavior of the volumes and capacities we then obtain upper bounds
for the number of ends as well as estimates for the fundamental tone of the
submanifolds in question.


title: Classes of Complete Simple Games that are All Weighted

abstract:
  Important decisions are likely made by groups of agents. Thus group decision
making is very common in practice. Very transparent group aggregating rules are
given by weighted voting, where each agent is assigned a weight. Here a
proposal is accepted if the sum of the weights of the supporting agents meets
or exceeds a given quota. We study a more general class of binary voting
systems -- complete simple games -- and propose an algorithm to determine which
sub classes, parameterized by the agent's type composition, are weighted.


title:
Interpolation and Approximation of Polynomials in Finite Fields over a
  Short Interval from Noisy Values

abstract:
  Motivated by a recently introduced HIMMO key distribution scheme, we consider
a modification of the noisy polynomial interpolation problem of recovering an
unknown polynomial $f(X) \in Z[X]$ from approximate values of the residues of
$f(t)$ modulo a prime $p$ at polynomially many points $t$ taken from a short
interval.


title: Dust from AGBs: relevant factors and modelling uncertainties

abstract:
  The dust formation process in the winds of Asymptotic Giant Branch stars is
discussed, based on full evolutionary models of stars with mass in the range
$1$M$_{\odot} \leq$M$\leq 8$M$_{\odot}$, and metallicities $0.001 < Z <0.008$.
Dust grains are assumed to form in an isotropically expanding wind, by growth
of pre--existing seed nuclei. Convection, for what concerns the treatment of
convective borders and the efficiency of the schematization adopted, turns out
to be the physical ingredient used to calculate the evolutionary sequences with
the highest impact on the results obtained. Low--mass stars with M$\leq
3$M$_{\odot}$ produce carbon type dust with also traces of silicon carbide. The
mass of solid carbon formed, fairly independently of metallicity, ranges from a
few $10^{-4}$M$_{\odot}$, for stars of initial mass $1-1.5$M$_{\odot}$, to
$\sim 10^{-2}$M$_{\odot}$ for M$\sim 2-2.5$M$_{\odot}$; the size of dust
particles is in the range $0.1 \mu$m$\leq a_C \leq 0.2\mu$m. On the contrary,
the production of silicon carbide (SiC) depends on metallicity. For $10^{-3}
\leq Z \leq 8\times 10^{-3}$ the size of SiC grains varies in the range $0.05
\mu {\rm m} < {\rm a_{SiC}} < 0.1 \mu$m, while the mass of SiC formed is
$10^{-5}{\rm M}_{\odot} < {\rm M_{SiC}} < 10^{-3}{\rm M}_{\odot}$. Models of
higher mass experience Hot Bottom Burning, which prevents the formation of
carbon stars, and favours the formation of silicates and corundum. In this case
the results scale with metallicity, owing to the larger silicon and aluminium
contained in higher--Z models. At Z=$8\times 10^{-3}$ we find that the most
massive stars produce dust masses $m_d \sim 0.01$M$_{\odot}$, whereas models of
smaller mass produce a dust mass ten times smaller. The main component of dust
are silicates, although corundum is also formed, in not negligible quantities
($\sim 10-20\%$).


title: Time series forecasting using neural networks

abstract:
  Recent studies have shown the classification and prediction power of the
Neural Networks. It has been demonstrated that a NN can approximate any
continuous function. Neural networks have been successfully used for
forecasting of financial data series. The classical methods used for time
series prediction like Box-Jenkins or ARIMA assumes that there is a linear
relationship between inputs and outputs. Neural Networks have the advantage
that can approximate nonlinear functions. In this paper we compared the
performances of different feed forward and recurrent neural networks and
training algorithms for predicting the exchange rate EUR/RON and USD/RON. We
used data series with daily exchange rates starting from 2005 until 2013.


title:
Stellar irradiated discs and implications on migration of embedded
  planets II: accreting-discs

abstract:
  The strength and direction of migration of embedded low mass planets depends
on the disc's structure. It has been shown that, in discs with viscous heating
and radiative transport, the migration can be directed outwards. In this paper
we investigate the influence of a constant dM/dt-flux through the disc, as well
as the influence of the disc's metallicity on the disc's thermodynamics. We
focus on dM/dt discs, which have a net mass flux through them. Utilizing the
resulting disc structure, we determine the regions of outward migration in the
disc. We perform numerical hydrosimulations of dM/dt discs with viscous
heating, radiative cooling and stellar irradiation in 2D in the r-z-plane. We
use the explicit/implicit hydrodynamical code FARGOCA that includes a full
tensor viscosity and stellar irradiation, as well as a two temperature solver
that includes radiation transport in the flux-limited diffusion approximation.
The migration of embedded planets is studied by using torque formulae. For a
disc of gas surface density and viscosity, we find that the discs thermal
structure depends on the product Sigma_G \nu and the amount of heavy elements,
while the migration of planets additionally to the mentioned quantities,
depends on the amount of viscosity itself. As a result of this, the disc
structure can not be approximated by simple power laws. During the lifetime of
the disc, the structure of the disc changes significantly in a non-linear way
in the inner parts. In the late stages of the discs evolution, outward
migration is only possible if the metallicity of the disc is high. For low
metallicity, planets would migrate inwards and could potentially be lost. The
presented disc structures and migration maps have important consequences on the
formation of planets, as they can give hints on the different formation
mechanisms for different types of planets as a function of metallicity.


title: On weakly $\frak{F}_{s}$-quasinormal subgroups of finite groups

abstract:
  Let $\mathfrak{F}$ be a formation and $G$ a finite group. A subgroup $H$ of
$G$ is said to be weakly $\mathfrak{F}_{s}$-quasinormal in $G$ if $G$ has an
$S$-quasinormal subgroup $T$ such that $HT$ is $S$-quasinormal in $G$ and
$(H\cap T)H_{G}/H_{G}\leq Z_{\mathfrak{F}}(G/H_{G})$, where
$Z_{\mathfrak{F}}(G/H_{G})$ denotes the $\mathfrak{F}$-hypercenter of
$G/H_{G}$. In this paper, we study the structure of finite groups by using the
concept of weakly $\mathfrak{F}_{s}$-quasinormal subgroups.


title: Finite and infinitesimal rigidity with polyhedral norms

abstract:
  We characterise finite and infinitesimal rigidity for bar-joint frameworks in
R^d with respect to polyhedral norms (i.e. norms with closed unit ball P a
convex d-dimensional polytope). Infinitesimal and continuous rigidity are shown
to be equivalent for finite frameworks in R^d which are well-positioned with
respect to P. An edge-labelling determined by the facets of the unit ball and
placement of the framework is used to characterise infinitesimal rigidity in
R^d in terms of monochrome spanning trees. An analogue of Laman's theorem is
obtained for all polyhedral norms on R^2.


title: Analytic conformal compactification of Schwarzschild spacetime

abstract:
  Among the coordinates used to construct a conformal compactification of the
Schwarzschild spacetime, none of them simultaneously extend smoothly both
through an event horizon and beyond null infinity.To construct such
coordinates, instead of starting with the Kruskal-Szekeres coordinates we
assume direct analytic transformation between Schwarzschild and compactified
coordinates and determine their behavior on the event horizon and at null
infinity. We then propose an example of such coordinates and illustrate the way
they cover the conformally extended Schwarzschild spacetime as well as their
suitability for numerical applications.


title: Measurement-device-independent randomness from local entangled states

abstract:
  Nonlocal correlations are useful for device independent (DI) randomness
certification [Nature (London) {\bf 464}, 1021 (2010)]. The advantage of this
DI protocol over the conventional quantum protocol is that randomness can be
certified even when experimental apparatuses are not trusted. Quantum
entanglement is the necessary physical source for the nonlocal correlation
required for such DI task. However, nonlocality and entanglement are distinct
concepts. There exist entangled states which produce no nonlocal correlation
and hence are not useful for the DI randomness certification task. Here we
introduce the measurement-device-independent randomness certification task
where one has trusted quantum state preparation device but the measurement
devices are completely unspecified. Interestingly we show that there exist
entangled states, with local description, that are useful resource in such task
which otherwise are useless in corresponding DI scenario.


title:
Fluctuation-induced pressures in fluids in thermal nonequilibrium steady
  states

abstract:
  Correlations in fluids in nonequilibrium steady states are long ranged.
Hence, finite-size effects have important consequences in the nonequilibrium
thermodynamics of fluids. One consequence is that nonequilibrium temperature
fluctuations induce nonequilibrium Casimir-like pressures proportional to the
square of the temperature gradient. Hence, fluctuations cause a breakdown of
the concept of local thermal equilibrium. Furthermore, transport coefficients
become dependent on boundary conditions and on gravity. Thus nonequilibrium
fluctuations affect some traditional concepts in nonequilibrium thermodynamics.


title: The n-point correlation of quadratic forms

abstract:
  In this paper we investigate the distribution of the set of values of a
quadratic form Q, at integral points. In particular we are interested in the
n-point correlations of the this set. The asymptotic behaviour of the counting
function that counts the number of n-tuples of integral points
$\left(v_{1},\dots,v_{n}\right)$, with bounded norm, such that the n-1
differences $Q\left(v_{1}\right)-Q\left(v_{2}\right),\dots
Q\left(v_{n-1}\right)-Q\left(v_{n}\right)$, lie in prescribed intervals is
obtained. The results are valid provided that the quadratic form has rank at
least 5, is not a multiple of a rational form and n is at most the rank of the
quadratic form. For certain quadratic forms satisfying Diophantine conditions
we obtain a rate for the limit. The proofs are based on those in the recent
preprint ([G-M]) of F. G$\"o$tze and G. Margulis, in which they prove an
`effective' version of the Oppenheim Conjecture. In particular, the proofs rely
on Fourier analysis and estimates for certain theta series.


title:
A first regularity result for the Armstrong-Frederick cyclic hardening
  plasticity model with Cosserat effects

abstract:
  The purpose of this article is to prove the H\"older continuity up to the
boundary of the displacement vector and the microrotation matrix for the
quasistatic, rate-independent Armstrong-Frederick cyclic hardening plasticity
model with Cosserat effects. This model is of non-monotone and non-associated
type. In the case of two space dimensions we use the hole-filling technique of
Widman and the Morrey's Dirichlet growth theorem.


title:
The AGN content of deep radio surveys and radio emission in radio-quiet
  AGN. Why every astronomer should care about deep radio fields

abstract:
  We present our very recent results on the sub-mJy radio source populations at
1.4 GHz based on the Extended Chandra Deep Field South VLA survey, which
reaches ~ 30 {\mu}Jy, with details on their number counts, evolution, and
luminosity functions. The sub-mJy radio sky turns out to be a complex mix of
star-forming galaxies and radio-quiet AGN evolving at a similar, strong rate
and declining radio-loud AGN. While the well-known flattening of the radio
number counts below 1 mJy is mostly due to star-forming galaxies, these sources
and AGN make up an approximately equal fraction of the sub-mJy sky. Our results
shed also light on a fifty-year-old issue, namely radio emission from
radio-quiet AGN, and suggest that it is closely related to star formation, at
least at z ~ 1.5 - 2. The implications of our findings for future, deeper radio
surveys, including those with the Square Kilometre Array, are also discussed.
One of the main messages, especially to non-radio astronomers, is that radio
surveys are reaching such faint limits that, while previously they were mainly
useful for radio quasars and radio galaxies, they are now detecting mostly
star-forming galaxies and radio-quiet AGN, i.e., the bulk of the extragalactic
sources studied in the infrared, optical, and X-ray bands.


title:
The cometary HII regions of DR 21: Bow shocks or champagne flows or
  both?

abstract:
  We present deep Very Large Array H66$\alpha$ radio recombination line (RRL)
observations of the two cometary HII regions in DR 21. With these sensitive
data, we test the "hybrid" bow shock/champagne flow model previously proposed
for the DR 21 HII regions. The ionized gas down the tail of the southern HII
region is redshifted by up to ~30 km/s with respect to the ambient molecular
gas, as expected in the hybrid scenario. The RRL velocity structure, however,
reveals the presence of two velocity components in both the northern and
southern HII regions. This suggests that the ionized gas is flowing along
cone-like shells, swept-up by stellar winds. The observed velocity structure of
the well-resolved southern HII region is most consistent with a picture that
combines a stellar wind with stellar motion (as in bow shock models) along a
density gradient (as in champagne flow models). The direction of the implied
density gradient is consistent with that suggested by maps of dust continuum
and molecular line emission in the DR 21 region.


title:
Diffuse Gas in Galaxies Sheds New Light on the Origin of Type Ia
  Supernovae

abstract:
  We measure the strength of HeII$\lambda$4686 nebular emission in passively
evolving ("retired") galaxies, aiming to constrain their populations of hot
accreting white dwarfs (WDs) in the context of the single degenerate (SD)
scenario of Type Ia supernovae (SNe Ia). In the SD scenario, as a WD burns
hydrogen-rich material accreted from a companion star, it becomes a powerful
source of ionizing UV emission. If significant populations of such sources
exist in galaxies, strong emission in the recombination lines of HeII should be
expected from the interstellar medium. To explore this conjecture, we select
from the Sloan Digital Sky Survey ~11 500 emission line galaxies with stellar
ages >1 Gyr showing no signs of AGN activity and co-add their spectra in bins
of stellar population age. For the first time, we detect HeII$\lambda$4686
nebular emission in retired galaxies and find it to be significantly weaker
than that expected in the SD scenario, especially in the youngest age bin (1-4
Gyr) where the SN Ia rate is the highest. Instead, the strength of the observed
HeII$\lambda$4686 nebular emission is consistent with post-asymptotic giant
branch stars being the sole ionizing source in all age bins. These results
limit populations of accreting WDs with photospheric temperatures ($T_{\rm
eff}$) in the range ~(1.5-6)$\cdot 10^5$ K to the level at which they can
account for no more than ~5-10% of the observed SN Ia rate. Conversely, should
all WD progenitors of SN Ia go through the phase of steady nuclear burning with
$T_{\rm eff}$~(1.5-6)$\cdot 10^5$ K, they do not increase their mass by more
than ~0.03 $M_\odot$ in this regime.

categories: astro-ph.GA astro-ph.CO astro-ph.HE astro-ph.SR


title:
Recent progress towards a chiral effective field theory for the NN
  system

abstract:
  Since Weinberg's proposal two decades ago, chiral effective field theory in
the NN sector has been developed and applied up to order $O((Q/M_{hi})^4)$. In
principle it could provide a model-independent description of nuclear force
from QCD. However, in spite of its huge success, some open issues such as the
renormalization group invariance and power counting, still remain to be solved.
In this talk we refine the chiral effective field theory approach to the NN
system based on a renormalization group analysis. Our results show that a truly
model-independent description of NN system can be obtained by a new power
counting which treats the subleading order corrections perturbatively.


title: Quadrature Compressive Sampling for Radar Signals

abstract:
  Quadrature sampling has been widely applied in coherent radar systems to
extract in-phase and quadrature (I and Q) components in the received radar
signal. However, the sampling is inefficient because the received signal
contains only a small number of significant target signals. This paper
incorporates the compressive sampling (CS) theory into the design of the
quadrature sampling system, and develops a quadrature compressive sampling
(QuadCS) system to acquire the I and Q components with low sampling rate. The
QuadCS system first randomly projects the received signal into a compressive
bandpass signal and then utilizes the quadrature sampling to output compressive
I and Q components. The compressive outputs are used to reconstruct the I and Q
components. To understand the system performance, we establish the frequency
domain representation of the QuadCS system. With the waveform-matched
dictionary, we prove that the QuadCS system satisfies the restricted isometry
property with overwhelming probability. For K target signals in the observation
interval T, simulations show that the QuadCS requires just O(Klog(BT/K))
samples to stably reconstruct the signal, where B is the signal bandwidth. The
reconstructed signal-to-noise ratio decreases by 3dB for every octave increase
in the target number K and increases by 3dB for every octave increase in the
compressive bandwidth. Theoretical analyses and simulations verify that the
proposed QuadCS is a valid system to acquire the I and Q components in the
received radar signals.


title: MANIAC Challenge: The Wolf-pack strategy

abstract:
  MANIAC Challenge raises a problem of game theory, different players
strategies intertwine and the success of any player is dependent on the actions
of all players in the system. A truly fair scenario is when all the strategies
are identical, all the nodes co-operate and they all equally share the rewards
and risks that come with every transfer. A successful strategy is one that
tries to diverge from the equilibrium to maximize its own gains and it manages
to do so. We propose the wolf-pack strategy. Unlike standard game-theory based
strategies, our strategy does not penalize the nodes that diverge from fairness
or from equilibrium, as we believe most nodes will do so in an attempt to get
an advantage over the other nodes. The wolf-pack strategy will try to always
find the most successful node or nodes and penalize them. We believe that just
like in nature, a number of small predators can take down the bigger, more
profitable ones. Furthermore during the Challenge we test two different
strategies that provide completely opposite results. These offer a clear
picture of what the best strategy is and the problems of the current system.


title:
Switching Reciprocity On and Off in a Magneto-Optical X-Ray Scattering
  Experiment Using Nuclear Resonance of 57Fe Foils

abstract:
  Reciprocity is when the scattering amplitude of wave propagation satisfies a
symmetry property, connecting a scattering process with an appropriate reversed
one. We report on an experiment using nuclear resonance scattering of
synchrotron radiation, which demonstrates that magneto-optical materials do not
necessarily violate reciprocity. The setting enables to switch easily between
reciprocity and its violation. In the latter case, the exhibited reciprocity
violation is orders of magnitude larger than achieved by previous wave
scattering experiments.


title: Selfishness as a Virtue in Mobile Ad Hoc Networks

abstract:
  Using Mobile Ad Hoc Networks as a way to break the dependency of mobile
communications on permanent infrastructure has been an active area of research
for several years, but only more recently has consideration been given to the
economics of a distributed mobile service. In particular, the topic of handling
nodes that act selfishly or maliciously has not yet been explored in detail. In
this paper, we discuss the SAVMAN strategy for mobile offloading under the
rules of the 2013 MANIAC Challenge.


title: Theoretical description of deeply virtual Compton scattering off $^3$He

abstract:
  Recently, coherent deeply virtual Compton scattering (DVCS) off $^3$He nuclei
has been proposed to access the neutron generalized parton distributions
(GPDs). In Impulse Approximation (IA) studies, it has been shown, in
particular, that the sum of the two leading twist, quark helicity conserving
GPDs of $^3$He, $H$ and $E$, at low momentum transfer, is dominated by the
neutron contribution, so that $^3$He is very promising for the extraction of
the neutron information. Nevertheless, such an extraction could be not trivial.
A technique, able to take into account the nuclear effects included in the IA
analysis in the extraction procedure, has been therefore developed. In this
work, the IA calculation of the spin dependent GPD $\tilde H$ of $^3$He is
presented for the first time. This quantity is found to be largely dominated,
at low momentum transfer, by the neutron contribution, which could be extracted
using arguments similar to the ones previously proposed for the other GPDs. The
known forward limit of the IA calculation of $\tilde H$, yielding the polarized
parton distributions of $^3$He, is correctly recovered. The knowledge of the
GPDs $H, E$ and $\tilde H$ of $^3$He will allow now the evaluation of the cross
section asymmetries which are relevant for coherent DVCS off $^3$He at
Jefferson Lab kinematics, an important step towards the planning of possible
experiments.


title:
Multi-band effects on Fulde-Ferrell-Larkin-Ovchinnikov states of
  Pauli-limited superconductors

abstract:
  Multi-band effects on Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) states of a
Pauli-limiting two-band superconductor are studied theoretically, based on
self-consistent calculations of the Bogoliubov-de Gennes equation. First, we
examine the phase diagrams of two-band systems with a passive band in which the
intraband pairing interaction is absent and superconductivity is induced by a
Cooper pair tunneling from an active band. It is demonstrated that the
temperature of the Lifshitz point at which three second-order transition lines
meet is independent of the Cooper pair tunneling strength. The BCS-FFLO
critical field becomes lower than the Lifshitz point with increasing the
interband tunneling strength, and the resultant phase diagram is qualitatively
different from that in a single-band superconductor. We also study the
thermodynamics of Pauli-limiting two-band superconductors with comparable
intraband pairing interactions. As a consequence of a competing effect between
two bands, the FFLO phase is divided into two phases: $Q_1$- and $Q_2$-FFLO
phases. The $Q_1$-FFLO is favored in a high field regime and the $Q_2$-FFLO
becomes stable in the lower field. In a particular case, the latter is further
subdivided into a family of FFLO states with rational modulation lengths,
leading to a devil's staircase structure in the field-dependence of physical
quantities. The critical field, above which the FFLO is stabilized, is lower
than that in a single band superconductor, while the temperature of tricritical
Lifshitz point is invariant under the change of two-band parameters.


title:
Fast transitionless expansions of Gaussian anharmonic traps for cold
  atoms: bang-singular-bang control

abstract:
  Combining invariant-based inverse engineering, perturbation theory, and
Optimal Control Theory, we design fast, transitionless expansions of cold
neutral atoms or ions in Gaussian anharmonic traps. Bounding the possible trap
frequencies and using a "bang-singular-bang" control we find fast processes for
a continuum of durations up to a minimum time that corresponds to a purely
bang-bang (stepwise frequency constant) control.


title: Linear Independence of Time-Frequency Shifts?

abstract:
  We investigate finite sections of Gabor frames and study the asymptotic
behavior of their lower Riesz bound. From a numerical point of view, these sets
of time-frequency shifts are linearly dependent, whereas from a rigorous
analytic point of view, they are conjectured to be linearly independent.


title: Spectral flow for nonunital spectral triples

abstract:
  We prove two results about nonunital index theory left open by [CGRS2]. The
first is that the spectral triple arising from an action of the reals on a
C*-algebra with invariant trace satisfies the hypotheses of the nonunital local
index formula. The second result concerns the meaning of spectral flow in the
nonunital case. For the special case of paths arising from the odd index
pairing for smooth spectral triples in the nonunital setting we are able to
connect with earlier approaches to the analytic definition of spectral flow.


title:
A topological approach to the existence and multiplicity of positive
  solutions of $(p,q)$-Laplacian systems

abstract:
  In this paper we develop a new theory for the existence, localization and
multiplicity of positive solutions for a class of non-variational,quasilinear,
elliptic systems. In order to do this, we provide a fairly general abstract
framework for the existence of fixed points of nonlinear operators acting on
cones that satisfy an inequality of Harnack type. Our methodology relies on
fixed point index theory. We also provide a non-existence result and an example
to illustrate the theory.


title: Symmetric periodic orbits and uniruled real Liouville domains

abstract:
  A real Liouville domain is a Liouville domain together with an exact
anti-symplectic involution. We call a real Liouville domain uniruled if there
exists an invariant finite energy plane through every real point.
Asymptotically an invariant finite energy plane converges to a symmetric
periodic orbit. In this note we work out a criterion which guarantees
uniruledness for real Liouville domains.


title:
The O(n) $\phi^4$ model with free surfaces in the large-$n$ limit: Some
  exact results for boundary critical behaviour, fluctuation-induced forces and
  distant-wall corrections

abstract:
  The $O(n)$ ${\phi}^4$ model on a slab $\mathbb{R}^{d-1}\times[0,L]$ bounded
by free surfaces is studied for $2<d<4$ in the limit $n\to\infty$. The
self-consistent potential $V(z)$ which the exact $n\to\infty$ solution of the
model involves is analysed by means of boundary operator expansions. Building
on the known exact $n\to\infty$ solution for $V(z)$ in the semi-infinite case
$L=\infty$ at the bulk critical point, we exactly determine two types of
corrections to this potential: (i) those linear in the temperature scaling
field $t$ at $L=\infty$, and (ii) the leading $L$-dependent (distant-wall)
corrections at the critical point. From (i) exact analytical results at $d=3$
are obtained for the leading temperature singularity of the excess surface free
energy and the implied asymptotic behaviours of the scaling functions
$\Theta_3(x)$ and $\vartheta_3(x)$ of the residual free energy $f_{\rm res}
=L^{1-d}\,\Theta_d(tL)$ and the critical Casimir force $\beta\mathcal{F}_{\rm
C}(T,L)=L^{-d}\,\vartheta_d(tL)$ in the limit $x\to 0\pm$. The second
derivative $\vartheta_3''(0)$ is computed exactly.


title:
The post-common-envelope, binary central star of the planetary nebula
  Hen 2-11

abstract:
  We present a detailed photometric study of the central star system of the
planetary nebula Hen 2-11, selected for study because of its low-ionisation
filaments and bipolar morphology - traits which have been strongly linked with
central star binarity. Photometric monitoring with NTT-EFOSC2 reveals a highly
irradiated, double-eclipsing, post-common-envelope system with a period of
0.609 d. Modelling of the lightcurve indicates that the nebular progenitor is
extremely hot, while the secondary in the system is probably a K-type main
sequence star. The chemical composition of the nebula is analysed, showing Hen
2-11 to be a medium-excitation non-Type I nebula. A simple photoionisation
model is constructed determining abundance ratios of C/O and N/O which would be
consistent with the common-envelope cutting short the AGB evolution of the
nebular progenitor.
  The detection of a post-common-envelope binary system at the heart of Hen
2-11 further strengthens the link between binary progeny and the formation of
axisymmetric planetary nebulae with patterns of low-ionisation filaments,
clearly demonstrating their use as morphological indicators of central star
binarity.


title:
Interplay of symmetries, null forms, Darboux polynomials, integrating
  factors and Jacobi multipliers in integrable second order differential
  equations

abstract:
  In this work, we establish a connection between the extended Prelle-Singer
procedure (Chandrasekar \textit{et al.} Proc. R. Soc. A 2005) with five other
analytical methods which are widely used to identify integrable systems in the
contemporary literature, especially for second order nonlinear ordinary
differential equations (ODEs). By synthesizing these methods we bring out the
interplay between Lie point symmetries, $\lambda$-symmetries, adjoint
symmetries, null-forms, Darboux polynomials, integrating factors and Jacobi
last multiplier in identifying the integrable systems described by second order
ODEs. We also give new perspectives to the extended Prelle-Singer procedure
developed by us. We illustrate these subtle connections with modified Emden
equation as a suitable example.


title: Self-propulsion through symmetry breaking

abstract:
  In addition to self-propulsion by phoretic mechanisms that arises from an
asymmetric distribution of reactive species around a catalytic motor, spherical
particles with a uniform distribution of catalytic activity may also propel
themselves under suitable conditions. Reactive fluctuation-induced asymmetry
can give rise to transient concentration gradients which may persist under
certain conditions, giving rise to a bifurcation to self-propulsion. The nature
of this phenomenon is analyzed in detail, and particle-level simulations are
carried out to demonstrate its existence.


title:
$\ell^p(\mathbb{Z})$ -- boundedness of discrete maximal functions along
  thin subsets of primes and pointwise ergodic theorems

abstract:
  We establish the first pointwise ergodic theorems along thin sets of prime
numbers; a set with zero density with respect to the primes. For instance we
will be able to achieve this with the Piatetski-Shapiro primes. Our methods
will be robust enough to solve the ternary Goldbach problem for some thin sets
of primes.


title: Finite-volume effects in the evaluation of the K_L - K_S mass difference

abstract:
  The RBC and UKQCD collaborations have recently proposed a procedure for
computing the K_L-K_S mass difference. A necessary ingredient of this procedure
is the calculation of the (non-exponential) finite-volume corrections relating
the results obtained on a finite lattice to the physical values. This requires
a significant extension of the techniques which were used to obtain the
Lellouch-Luscher factor, which contains the finite-volume corrections in the
evaluation of non-leptonic kaon decay amplitudes. We review the status of our
study of this issue and, although a complete proof is still being developed,
suggest the form of these corrections for general volumes and a strategy for
taking the infinite-volume limit. The general result reduces to the known
corrections in the special case when the volume is tuned so that there is a
two-pion state degenerate with the kaon.


title:
Determination of Doping and Temperature Dependent Elastic Constants of
  Degenerately Doped Silicon from MEMS Resonators

abstract:
  Elastic constants c11, c12 and c44 of degenerately doped silicon are studied
experimentally as a function of the doping level and temperature. First and
second order temperature coefficients of the elastic constants are extracted
from measured resonance frequencies of a set of MEMS resonators fabricated on
seven different wafers doped with phosphorus (carrier concentrations 4.1, 4.7,
and 7.5*10^19 cm^-3), arsenic (1.7, 2.5*10^19 cm^-3), and boron (0.6, 3*10^19
cm^-3), respectively. Measurements cover a temperature range from -40 to +85 C.
  It is found that that the linear temperature coefficient of the shear elastic
parameter c11-c12 is zero at n-type doping level of n~2*10^19 cm^-3, and that
it increases to over 40 ppm/K with increasing doping. This observation implies
that the frequency of many types of resonance modes, including extensional bulk
modes and flexural modes, can be temperature compensated to first order. The
second order temperature coefficient of c11-c12 is found to decrease by 40% in
magnitude when n-type doping is increased from 4.1 to 7.5*10^19 cm^-3.
  Results of this study enable calculation of the frequency drift of an
arbitrary silicon resonator design with an accuracy of +/- 25 ppm over T=-40
... 85 C at the doping levels covered in this work. Absolute frequency can be
estimated with an accuracy of +/- 1000 ppm.


title:
Elliptic flow and nuclear modification factor in ultra-relativistic
  heavy-ion collisions within a partonic transport model

abstract:
  The quark gluon plasma produced in ultra-relativistic heavy-ion collisions
exhibits remarkable features. It behaves like a nearly perfect liquid with a
small shear viscosity to entropy density ratio and leads to the quenching of
highly energetic particles. We show that both effects can be understood for the
first time within one common framework. Employing the parton cascade Boltzmann
Approach to Multi-Parton Scatterings (BAMPS), the microscopic interactions and
the space-time evolution of the quark gluon plasma are calculated by solving
the relativistic Boltzmann equation. Based on cross sections obtained from
perturbative QCD with explicitly taking the running coupling into account, we
calculate the nuclear modification factor and elliptic flow in
ultra-relativistic heavy-ion collisions. With only one single parameter
associated with coherence effects of medium-induced gluon radiation, the
experimental data of both observables can be understood on a microscopic level.
Furthermore, we show that perturbative QCD interactions with a running coupling
lead to a sufficiently small shear viscosity to entropy density ratio of the
quark gluon plasma, which provides a microscopic explanation for the
observations stated by hydrodynamic calculations.


title: Exocomets in the circumstellar gas disk of HD 172555

abstract:
  The source HD172555 is a young A7V star surrounded by a debris disk with a
gaseous component. Here, we present the detection of variable absorption
features detected simultaneously in the Ca II K and H doublet lines (at 3,933
and 3,968 Angstrom). We identified the presence of these absorption signatures
at four different epochs in the 129 HARPS high-resolution spectra gathered
between 2004 and 2011. These transient absorption features are most likely due
to Falling Evaporating Bodies (FEBs, or exocomets) that produce absorbing gas
observed transiting in front of the central star. We also detect a stable Ca II
absorption component at the star's radial velocity. With no corresponding
detection in the Na I line, the resulting very low upper limit for the NaI/CaII
ratio suggests that this absorption is due to circumstellar gas.


title:
Latest advances in an astrometric model based on the Time Transfer
  Functions formalism

abstract:
  Given the extreme accuracy of modern space astrometry, a precise relativistic
modeling of observations is required. Moreover, the availability of several
models formulated in different and independent ways is a security against the
presence of systematic errors in the analysis of future experimental results,
like in the case of the Gaia mission. In this work, we simulate a series of
observations using the two models to be used for the data analysis of Gaia, the
Gaia RElativistic Model (GREM) and the Relativistic Astrometric MODel (RAMOD),
and we compare them with the results of our astrometric model based on the Time
Transfer Functions.


title:
General-relativistic electromagnetic fields around a slowly rotating
  neutron star: time-dependent pseudo-spectral simulations

abstract:
  Pulsars are believed to loose their rotational kinetic energy primarily by a
large amplitude low frequency electromagnetic wave which is eventually
converted into particle creation, acceleration and followed by a broad band
radiation spectrum. To date, there exist no detailed calculation of the exact
spin-down luminosity with respect to the neutron star magnetic moment and spin
frequency, including general-relativistic effects. Estimates are usually given
according to the flat spacetime magnetodipole formula. The present paper pursue
our effort to look for accurate solutions of the general-relativistic
electromagnetic field around a slowly rotating magnetized neutron star. In a
previous work, we already found approximate stationary solutions to this
problem. Here we address again this problem but using a more general approach.
We indeed solve the full set of time-dependent Maxwell equations in a curved
vacuum space-time following the 3+1 formalism. The numerical code is based on
our pseudo-spectral method exposed in a previous paper for flat space-time. We
adapted it to an arbitrary fixed background metric. Stationary solutions are
readily obtained and compared to semi-analytical calculations.


title:
Rate of convergence in the law of large numbers for supercritical
  general multi-type branching processes

abstract:
  We provide sufficient conditions for polynomial rate of convergence in the
weak law of large numbers for supercritical general indecomposable multi-type
branching processes. The main result is derived by investigating the embedded
single-type process composed of all individuals having the same type as the
ancestor. As an important intermediate step, we determine the (exact)
polynomial rate of convergence of Nerman's martingale in continuous time to its
limit. The techniques used also allow us to give streamlined proofs of the weak
and strong laws of large numbers and ratio convergence for the processes in
focus.


title: Controlling the level of sparsity in MPC

abstract:
  In optimization routines used for on-line Model Predictive Control (MPC),
linear systems of equations are usually solved in each iteration. This is true
both for Active Set (AS) methods as well as for Interior Point (IP) methods,
and for linear MPC as well as for nonlinear MPC and hybrid MPC. The main
computational effort is spent while solving these linear systems of equations,
and hence, it is of greatest interest to solve them efficiently. Classically,
the optimization problem has been formulated in either of two different ways.
One of them leading to a sparse linear system of equations involving relatively
many variables to solve in each iteration and the other one leading to a dense
linear system of equations involving relatively few variables. In this work, it
is shown that it is possible not only to consider these two distinct choices of
formulations. Instead it is shown that it is possible to create an entire
family of formulations with different levels of sparsity and number of
variables, and that this extra degree of freedom can be exploited to get even
better performance with the software and hardware at hand. This result also
provides a better answer to an often discussed question in MPC; should the
sparse or dense formulation be used. In this work, it is shown that the answer
to this question is that often none of these classical choices is the best
choice, and that a better choice with a different level of sparsity actually
can be found.


title:
Hamiltonian Expression of Curvature Tensors in the York Canonical Basis:
  I) The Riemann Tensor and Ricci Scalars

abstract:
  By using the York canonical basis of ADM tetrad gravity, in a formulation
using radar 4-coordinates for the parametrization of the 3+1 splitting of the
space-time, it is possible to write the 4-Riemann tensor of a globally
hyperbolic, asymptotically Minkowskian space-time as a Hamiltonian tensor,
whose components are 4-scalars with respect to the ordinary world
4-coordinates, plus terms vanishing due to Einstein's equations. Therefore
"on-shell" we find the expression of the Hamiltonian 4-Riemann tensor.
Moreover, the 3+1 splitting of the space-time used to define the phase space
allows us to introduce a Hamiltonian set of null tetrads and to find the
Hamiltonian expression of the 4-Ricci scalars of the Newman-Penrose formalism.
  This material will be used in the second paper to study the 4-Weyl tensor,
the 4-Weyl scalars and the four Weyl eigenvalues and to clarify the notions of
Dirac and Bergmann observables.


title: Circular Polarization of the CMB: A probe of the First stars

abstract:
  While it is revealed that the Cosmic Microwave Background (CMB) is linearly
polarized at 10 % level, it is predicted that there exists no significant
intrinsic source for circular polarization (CP) in the standard cosmology.
However, during the propagation through a magnetised plasma, the CP of the CMB
could be produced via the Faraday conversion (FC). The FC converts a
pre-existing linear polarization into CP in presence of a magnetic field with
relativistic electrons. In this paper, we focus on the FC due to supernova
remnants of the first stars, also called Pop III stars. We derive an analytic
form for the angular power spectrum of the CP of the CMB generated by the
general FC. We apply this result to the case of the FC triggered by explosions
of the first stars and evaluate the angular power spectrum, CV V . We show that
the amplitude of l(l + 1)C_l^V V /(2pi) > 10^-2 micro Kelvin squared for l >
100, with only one Pop III star per halo, the age of Pop III SN remnants as 104
years and frequency of CMB observation as 1 GHz. We expect the CP of the CMB to
be a very promising probe of the yet unobserved first stars, primarily due to
the expected high signal along with an unique frequency dependence.


title:
Phase-resolved X-ray spectroscopy and spectral energy distribution of
  the X-ray soft polar RS Caeli

abstract:
  RS Cae is the third target in our series of XMM-Newton observations of soft
X-ray-dominated polars. Our observational campaign aims to better understand
and describe the multiwavelength data, the physical properties of the system
components, and the short- and long-term behavior of the component fluxes in RS
Cae. We employ stellar atmosphere, stratified accretion-column, and widely used
X-ray spectral models. We fit the XMM-Newton spectra, model the multiband light
curves, and opt for a mostly consistent description of the spectral energy
distribution.
  Results. Our XMM-Newton data of RS Cae are clearly dominated by soft X-ray
emission. The X-ray light curves are shaped by emission from the main accretion
region, which is visible over the whole orbital cycle, interrupted only by a
stream eclipse. The optical light curves are formed by cyclotron and stream
emission. The XMM-Newton X-ray spectra comprise a black-body-like and a plasma
component at mean temperatures of 36eV and 7keV. The spectral fits give
evidence of a partially absorbing and a reflection component. Multitemperature
models, covering a broader temperature range in the X-ray emitting accretion
regions, reproduce the spectra appropriately well. Including archival data, we
describe the spectral energy distribution with a combination of models based on
a consistent set of parameters and derive a lower limit estimate of the
distance d > 750pc.
  Conclusions. The high bolometric soft-to-hard flux ratios and short-term
variability of the (X-ray) light curves are characteristic of inhomogeneous
accretion. RS Cae clearly belongs in the group of polars that show a very
strong soft X-ray flux compared to their hard X-ray flux. The different
black-body fluxes and similar hard X-ray and optical fluxes during the
XMM-Newton and ROSAT observations show that soft and hard X-ray emission are
not directly correlated.


title:
A spectral method in space and time to solve the advection-diffusion and
  wave equations in a bounded domain

abstract:
  The advection-diffusion and wave equations are the fundamental equations
governing any physical law and therefore arise in many areas of physics and
astrophysics. For complex problems and geometries, only numerical simulations
can give insight into quantitative and accurate behavior of the seeked
solutions. The standard numerical algorithm to solve partial differential
equations is to split the space and time discretisation separately into
different uncorrelated methods. Time is usually advanced by explicit schemes,
or, for too restrictive time steps, by implicit or semi-implicit algorithms.
This separate time and space slicing is artificial and sometimes unpractical.
Indeed, treating space and time directions symmetrically and simultaneously
without splitting is highly recommended in some problems like diffusion.
  It is the purpose of this work to present a simple numerical algorithm to
solve the standard linear scalar advection-diffusion and wave equations using a
fully spectral method in a two-dimensional Cartesian $(x,t)$ bounded space-time
domain. Generalization in three-dimensions $(x,y,t)$ is shown for the pure
diffusion problem. The basic idea is to expand the unknown function in
Chebyshev polynomials for the spatial variables $(x,y)$ as well as for the time
variable $t$. We show typical examples and demonstrate the spectral accuracy of
the method. The great advantage of fully spectral methods resides in their
high-accuracy for a relatively small number of grid points (for sufficiently
smooth solutions) compared to standard time-stepping techniques.


title: On the Six-dimensional Kerr Theorem and Twistor Equation

abstract:
  The Kerr theorem is revisited as part of the twistor program in six
dimensions. The relationship between pure spinors and integrable 3-planes is
investigated. The real condition for Lorentzian spacetimes is seen to induce a
projective property in the space of solutions, reminiscent of the quaternionic
structure of the 6-dimensional Lorentz group. The twistor equation (or Killing
spinor equations generically) also has an interpretation as integrable null
planes and a family of Einstein spacetimes with this property are presented in
the Kerr-Schild fashion.


title:
Hamiltonian Expression of Curvature Tensors in the York Canonical Basis:
  II) The Weyl Tensor, Weyl Scalars, the Weyl Eigenvalues and the Problem of
  the Observables of the Gravitational Field

abstract:
  We find the Hamiltonian expression in the York basis of canonical ADM tetrad
gravity of the 4-Weyl tensor of the asymptotically Minkowskian space-time. Like
for the 4-Riemann tensor we find a radar tensor (whose components are 4-scalars
due to the use of radar 4-coordinates), which coincides with the 4-Weyl tensor
on-shell on the solutions of Einstein's equations. Then, by using the
Hamiltonian null tetrads, we find the Hamiltonian expression of the Weyl
scalars of the Newman-Perose approach and of the four eigenvalues of the 4-Weyl
tensor.
  After having introduced the Dirac observables of canonical gravity, whose
determination requires the solution of the super-Hamiltonian and super-momentum
constraints, we discuss the connection of the Dirac observables with the notion
of 4-scalar Bergmann observables. Due to the use of radar 4-coordinates these
two types of observables coincide in our formulation of canonical ADM tetrad
gravity. However, contrary to Bergmann proposal, the Weyl eigenvalues are shown
not to be Bergmann observables, so that their relevance is only in their use
(first suggested by Bergmann and Komar) for giving a physical identification as
point-events of the mathematical points of the space-time 4-manifold.
  Finally we give the expression of the Weyl scalars in the Hamiltonian
Post-Minkowskian linearization of canonical ADM tetrad gravity in the family of
(non-harmonic) 3-orthogonal Schwinger time gauges.


title: Towards A Domain-specific Language For Pick-And-Place Applications

abstract:
  Programming robots is a complicated and time-consuming task. A robot is
essentially a real-time, distributed embedded system. Often, control and
communication paths within the system are tightly coupled to the actual
physical configuration of the robot. Thus, programming a robot is a very
challenging task for domain experts who do not have a dedicated background in
robotics. In this paper we present an approach towards a domain specific
language, which is intended to reduce the efforts and the complexity which is
required when developing robotic applications. Furthermore we apply a software
product line approach to realize a configurable code generator which produces
C++ code which can either be run on real robots or on a robot simulator.


title: Partition regularity without the columns property

abstract:
  A finite or infinite matrix A with rational entries is called partition
regular if whenever the natural numbers are finitely coloured there is a
monochromatic vector x with Ax=0. Many of the classical theorems of Ramsey
Theory may naturally be interpreted as assertions that particular matrices are
partition regular. In the finite case, Rado proved that a matrix is partition
regular if and only it satisfies a computable condition known as the columns
property. The first requirement of the columns property is that some set of
columns sums to zero.
  In the infinite case, much less is known. There are many examples of matrices
with the columns property that are not partition regular, but until now all
known examples of partition regular matrices did have the columns property. Our
main aim in this paper is to show that, perhaps surprisingly, there are
infinite partition regular matrices without the columns property --- in fact,
having no set of columns summing to zero.
  We also make a conjecture that if a partition regular matrix (say with
integer coefficients) has bounded row sums then it must have the columns
property, and prove a first step towards this.


title: Shell Evolutions and Nuclear Forces

abstract:
  During the last 30 years, and more specifically during the last 10 years,
many experiments have been carried out worldwide using different techniques to
study the shell evolution of nuclei far from stability. What seemed not
conceivable some decades ago became rather common: all known magic numbers that
are present in the valley of stability disappear far from stability and are
replaced by new ones at the drip line. By gathering selected experimental
results, beautifully consistent pictures emerge, that very likely take root in
the properties of the nuclear forces.The present manuscript describes some of
these discoveries and proposes an intuitive understanding of these shell
evolutions derived from observations. Extrapolations to yet unstudied regions,
as where the explosive r-process nucleosynthesis occurs, are proposed. Some
remaining challenges and puzzling questions are also addressed.


title:
A two-species hydrodynamic model of particles interacting through
  self-alignment

abstract:
  In this paper, we present a two-species Vicsek model, that describes
alignment interactions of self-propelled particles which can either move or
not. The model consists in two populations with distinct Vicsek dynamics that
interact only via the passage of the particles from one population to the
other. The derivation of a macroscopic description of this model is performed
using the methodology used for the Vicsek model: we find out a regime where
alignment in the whole population occurs. We obtain a new macroscopic model for
the densities of each populations and the common mean direction of the
particles. The treatment of the non-conservativity of the interactions requires
a detail study of the linearised interaction operator.


title: Analysis and simulation of rare events for SPDE

abstract:
  In this work, we consider the numerical estimation of the probability for a
stochastic process to hit a set B before reaching another set A. This event is
assumed to be rare. We consider reactive trajectories of the stochastic
Allen-Cahn partial differential evolution equation (with double well potential)
in dimension 1. Reactive trajectories are defined as the probability
distribution of the trajectories of a stochastic process, conditioned by the
event of hitting B before A. We investigate the use of the so-called Adaptive
Multilevel Splitting algorithm in order to estimate the rare event and simulate
reactive trajectories. This algorithm uses a \emph{reaction coordinate} (a real
valued function of state space defining level sets), and is based on (i) the
selection, among several replicas of the system having hit A before B, of those
with maximal reaction coordinate; (ii) iteration of the latter step. We choose
for the reaction coordinate the average magnetization, and for B the minimum of
the well opposite to the initial condition. We discuss the context, prove that
the algorithm has a sense in the usual functional setting, and numerically test
the method (estimation of rare event, and transition state sampling).


title: Reduced-complexity maximum-likelihood decoding for 3D MIMO code

abstract:
  The 3D MIMO code is a robust and efficient space-time coding scheme for the
distributed MIMO broadcasting. However, it suffers from the high computational
complexity if the optimal maximum-likelihood (ML) decoding is used. In this
paper we first investigate the unique properties of the 3D MIMO code and
consequently propose a simplified decoding algorithm without sacrificing the ML
optimality. Analysis shows that the decoding complexity is reduced from O(M^8)
to O(M^{4.5}) in quasi-static channels when M-ary square QAM constellation is
used. Moreover, we propose an efficient implementation of the simplified ML
decoder which achieves a much lower decoding time delay compared to the
classical sphere decoder with Schnorr-Euchner enumeration.


title:
On the inviscid limit of the 2D Euler equations with vorticity along the
  $(LMO^\alpha)_\alpha$ scale

abstract:
  In a recent paper [5], the global well-posedness of the two-dimensional Euler
equation with vorticity in \mbox{$L^1\cap LBMO$} was proved, where $ LBMO$ is a
Banach space which is strictly imbricated between \mbox{$L^\infty$} and $BMO$.
In the present paper we prove a global result of inviscid limit of the
Navier-stokes system with data in this space and other spaces with the same BMO
flavor. Some results of local uniform estimates on solutions of the
Navier-Stokes equations, independent of the viscosity, are also obtained.


title: Robustness properties of marginal composite likelihood estimators

abstract:
  Composite likelihoods are a class of alternatives to the full likelihood
which are widely used in many situations in which the likelihood itself is
intractable. A composite likelihood may be computed without the need to specify
the full distribution of the response, which means that in some situations the
resulting estimator will be more robust to model misspecification than the
maximum likelihood estimator. The purpose of this note is to show that such
increased robustness is not guaranteed. An example is given in which various
marginal composite likelihood estimators are inconsistent under model
misspecification, even though the maximum likelihood estimator is consistent.


title:
Entangling two macroscopic mechanical mirrors in a two-cavity
  optomechanical system

abstract:
  We propose a simple method to generate quantum entanglement between two
macroscopic mechanical resonators in a two-cavity optomechanical system. This
entanglement is induced by the radiation pressure of a single photon hopping
between the two cavities. Our results are analytical, so that the entangled
states are explicitly shown. Up to local operations, these states are two-mode
three-component states, and hence the degree of entanglement can be well
quantified by the concurrence. By analyzing the system parameters, we find
that, to achieve a maximum average entanglement, the system should work in the
single-photon strong-coupling regime and the deep-resolved-sideband regime.


title:
Large N Approach to Kaon Decays and Mixing 28 Years Later: Delta I = 1/2
  Rule, \hat B_K and Delta M_K

abstract:
  We review and update our results for K-> pipi decays and K^0-\bar K^0 mixing
obtained by us in the 1980s within an approach based on the dual representation
of QCD as a theory of weakly interacting mesons for large N colours. In our
analytic approach the dynamics behind the enhancement of ReA_0 and suppression
of ReA_2, the so-called Delta I = 1/2 rule for K-> pi pi decays, has a simple
structure: the usual octet enhancement through quark-gluon renormalization
group evolution down to the scales O(1 GeV) is continued as a meson evolution
down to zero momentum scales at which the factorization of hadronic matrix
elements is at work. The inclusion of lowest-lying vector meson contributions
in addition to the pseudoscalar ones and of Wilson coefficients in a momentum
scheme improves significantly the matching between quark-gluon and meson
evolutions. In particular, the anomalous dimension matrix governing the meson
evolution exhibits the structure of the known anomalous dimension matrix in the
quark-gluon evolution. The recent results on ReA_2 and ReA_0 from the RBC-UKQC
collaboration give support for our approach. In particular, the signs of the
two main contractions found numerically by these authors follow uniquely from
our analytic approach. At NLO in 1/N we obtain ReA_0/ReA_2= 16.0\pm 1.5 which
amounts to an order of magnitude enhancement over the strict large N limit
value sqrt{2}. QCD penguins contribute at 15% level to this result. We also
find \hat B_K=0.73\pm 0.02, with the smallness of 1/N corrections to the large
N value \hat B_K=3/4 resulting within our approach from an approximate
cancellation between pseudoscalar and vector meson one-loop contributions. We
summarize the status of Delta M_K in this approach.


title:
Multi-wavelength observations of the binary system PSR B1259-63/LS 2883
  around the 2010-2011 periastron passage

abstract:
  We report on broad multi-wavelength observations of the 2010-2011 periastron
passage of the gamma-ray loud binary system PSR B1259-63. High resolution
interferometric radio observations establish extended radio emission trailing
the position of the pulsar. Observations with the Fermi Gamma-ray Space
Telescope reveal GeV gamma-ray flaring activity of the system, reaching the
spin-down luminosity of the pulsar, around 30 days after periastron. There are
no clear signatures of variability at radio, X-ray and TeV energies at the time
of the GeV flare. Variability around periastron in the H$\alpha$ emission line,
can be interpreted as the gravitational interaction between the pulsar and the
circumstellar disk. The equivalent width of the H$\alpha$ grows from a few days
before periastron until a few days later, and decreases again between 18 and 46
days after periastron. In near infrared we observe the similar decrease of the
equivalent width of Br$\gamma$ line between the 40th and 117th day after the
periastron. For the idealized disk, the variability of the H$\alpha$ line
represents the variability of the mass and size of the disk. We discuss
possible physical relations between the state of the disk and GeV emission
under assumption that GeV flare is directly related to the decrease of the disk
size.


title:
Cosmological constraints from Sunyaev-Zeldovich cluster counts: an
  approach to account for missing redshifts

abstract:
  The accumulation of redshifts provides a significant observational bottleneck
when using galaxy cluster surveys to constrain cosmological parameters. We
propose a simple method to allow the use of samples where there is a fraction
of the redshifts that are not known. The simplest assumption is that the
missing redshifts are randomly extracted from the catalogue, but the method
also allows one to take into account known selection effects in the
accumulation of redshifts. We quantify the reduction in statistical precision
of cosmological parameter constraints as a function of the fraction of missing
redshifts for simulated surveys, and also investigate the impact of making an
incorrect assumption for the distribution of missing redshifts.


title:
Entanglement sharing through noisy qubit channels: One-shot optimal
  singlet fraction

abstract:
  Maximally entangled states--a resource for quantum information
processing--can only be shared through noiseless quantum channels, whereas in
practice channels are noisy. Here we ask: Given a noisy quantum channel, what
is the maximum attainable purity (measured by singlet fraction) of shared
entanglement for single channel use and local trace preserving operations? We
find an exact formula of the maximum singlet fraction attainable for a qubit
channel and give an explicit protocol to achieve the optimal value. The
protocol distinguishes between unital and nonunital channels and requires no
local post-processing. In particular, the optimal singlet fraction is achieved
by transmitting part of an appropriate pure entangled state, which is maximally
entangled if and only if the channel is unital. A linear function of the
optimal singlet fraction is also shown to be an upper bound on the distillable
entanglement of the mixed state dual to the channel.


title: The Cosmological Parameters 2014

abstract:
  This is a review article for The Review of Particle Physics 2014 (aka the
Particle Data Book). It forms a compact review of knowledge of the cosmological
parameters at the beginning of 2014. Topics included are Parametrizing the
Universe; Extensions to the standard model; Probes; Bringing observations
together; Outlook for the future.


title:
A numerical approach to Blow-up issues for dispersive perturbations of
  Burgers' equation

abstract:
  We provide a detailed numerical study of various issues pertaining to the
dynamics of the Burgers equation perturbed by a weak dispersive term: blow-up
in finite time versus global existence, nature of the blow-up, existence for
"long" times, and the decomposition of the initial data into solitary waves
plus radiation. We numerically construct solitons for fractionary Korteweg-de
Vries equations.


title:
Superdiffusion and Transport in 2d-systems with L\'evy Like Quenched
  Disorder

abstract:
  We present an extensive analysis of transport properties in superdiffusive
two dimensional quenched random media, obtained by packing disks with radii
distributed according to a L\'evy law. We consider transport and scaling
properties in samples packed with two different procedures, at fixed filling
fraction and at self-similar packing, and we clarify the role of the two
procedures in the superdiffusive effects. Using the behavior of the filling
fraction in finite size systems as the main geometrical parameter, we define an
effective L\'evy exponents that correctly estimate the finite size effects. The
effective L\'evy exponent rules the dynamical scaling of the main transport
properties and identify the region where superdiffusive effects can be
detected.


title: From density functional to Kondo: magnetic impurities in nanotubes

abstract:
  Low-temperature electronic conductance in nanocontacts, scanning tunneling
microscopy (STM), and metal break junctions involving magnetic atoms or
molecules is a growing area with important unsolved theoretical problems. While
the detailed relationship between contact geometry and electronic structure
requires a quantitative ab initio approach such as density functional theory
(DFT), the Kondo many-body effects ensuing from the coupling of the impurity
spin with metal electrons are most properly addressed by formulating a
generalized Anderson impurity model to be solved with, for example, the
numerical renormalization group (NRG) method. Since there is at present no
seamless scheme that can accurately carry out that program, we have in recent
years designed a systematic method for semiquantitatively joining DFT and NRG.
We apply this DFT-NRG scheme to the ideal conductance of single wall (4,4) and
(8,8) nanotubes with magnetic adatoms (Co and Fe), both inside and outside the
nanotube, and with a single carbon atom vacancy. A rich scenario emerges, with
Kondo temperatures generally in the Kelvin range, and conductance anomalies
ranging from a single channel maximum to destructive Fano interference with
cancellation of two channels out of the total four. The configuration yielding
the highest Kondo temperature (tens of Kelvins) and a measurable zero-bias
anomaly is that of a Co or Fe impurity inside the narrowest nanotube. The
single atom vacancy has a spin, but a very low Kondo temperature is predicted.
The geometric, electronic, and symmetry factors influencing this variability
are all accessible, which makes this approach methodologically instructive and
highlights many delicate and difficult points in the first-principles modeling
of the Kondo effect in nanocontacts.


title: Domain Representations Induced by Dyadic Subbases

abstract:
  We study domain representations induced by dyadic subbases and show that a
proper dyadic subbase S of a second-countable regular space X induces an
embedding of X in the set of minimal limit elements of a subdomain D of
$\{0,1,\perp\}\omega$. In particular, if X is compact, then X is a retract of
the set of limit elements of D.


title: Curvature invariant on noncommutative polyballs

abstract:
  In this paper we develop a theory of curvature (resp. multiplicity) invariant
for tensor products of full Fock spaces and also for tensor products of
symmetric Fock spaces. This is an attempt to find a more general framework for
these invariants and extend some of the results obtained by Arveson for the
symmetric Fock space, by the author and Kribs for the full Fock space, and by
Fang for the Hardy space over the polydisc. To prove the existence of the
curvature and its basic properties in these settings requires a new approach
based on noncommutative Berezin transforms and multivariable operator theory on
polyballs and varieties, as well as summability results for completely positive
maps. The results are presented in the more general setting of regular
polyballs.


title: Eigenvalues of the Tachibana Operator which Acts on Differential Forms

abstract:
  In the present paper we show spectral properties of a littleknown natural
Riemannian second-order differential operator acting on differential forms.


title:
Characteristic class of a bundle and the existence of a global Routh
  function

abstract:
  The possibility of the global Lagrangian reduction of a mechanical system
with symmetry is shown to be connected with the characteristic class of a
principal fiber bundle of the configuration space over the factor manifold. It
is proved that the reduced system is globally Lagrangian if and only if the
product of the momentum constant with this characteristic class is zero. In the
case of a rigid body rotating about a fixed point in an axially symmetric force
field the bundle over a 2-sphere is non-trivial, therefore the reduced system
admits a global Routh function if and only if the momentum constant is zero.


title:
Fibers of multi-way contingency tables given conditionals: relation to
  marginals, cell bounds and Markov bases

abstract:
  A reference set, or a fiber, of a contingency table is the space of all
realizations of the table under a given set of constraints such as marginal
totals. Understanding the geometry of this space is a key problem in algebraic
statistics, important for conducting exact conditional inference, calculating
cell bounds, imputing missing cell values, and assessing the risk of disclosure
of sensitive information.
  Motivated primarily by disclosure limitation problems where constraints can
come from summary statistics other than the margins, in this paper we study the
space $\mathcal{F_T}$ of all possible multi-way contingency tables for a given
sample size and set of observed conditional frequencies. We show that this
space can be decomposed according to different possible marginals, which, in
turn, are encoded by the solution set of a linear Diophantine equation. We
characterize the difference between two fibers: $\mathcal{F_T}$ and the space
of tables for a given set of corresponding marginal totals. In particular, we
solve a generalization of an open problem posed by Dobra et al. (2008). Our
decomposition of $\mathcal{F_T}$ has two important consequences: (1) we derive
new cell bounds, some including connections to Directed Acyclic Graphs, and (2)
we describe a structure for the Markov bases for the space $\mathcal{F_T}$ that
leads to a simplified calculation of Markov bases in this particular setting.


title: A map between Galilean relativity and special relativity

abstract:
  A map is discussed that connects, in 1+1 dimensions, Galilei's relativity to
Einstein's special relativity. By means of this map it is possible to derive
special-relativistic formulas from the corresponding Galilean ones. Beyond
being interesting on its own, this map is also significant with respect to a
recent debate on the extension of relativistic symmetries to the Planck scale
(especially in the framework of the so-called doubly special relativity). The
map in fact provides an explicit example of how can be misleading to interpret
a mathematical correspondence between two relativity schemes as an argument in
favor of their physical equivalence.


title: List-coloring apex-minor-free graphs

abstract:
  A graph H is t-apex if H-X is planar for some subset X of V(H) of size t. For
any integer t>=0 and a fixed t-apex graph H, we give a polynomial-time
algorithm to decide whether a (t+3)-connected H-minor-free graph is colorable
from a given assignment of lists of size t+4. The connectivity requirement is
the best possible in the sense that for every t>=1, there exists a t-apex graph
H such that testing (t+4)-colorability of (t+2)-connected H-minor-free graphs
is NP-complete. Similarly, the size of the lists cannot be decreased (unless
P=NP), since for every t>=1, testing (t+3)-list-colorability of (t+3)-connected
K_{t+4}-minor-free graphs is NP-complete.


title: Some aspects of non-abelian gauge field inflation model

abstract:
  In this paper we study non-abelian gauge field inflation (gauge-flation)
model in the context of intermediate and logamediate scenario. Important
parameters of this model are presented for these two cases. Numerical study
shows that the intermediate and logamediate gauge-flation are compatible with
WMAP9 observational data. For intermediate inflation, where the cosmological
scale factor expands as: $a(t)=a_0\exp(At^f)$ ($A>0, 0<f<1$), $N\geq 100$ cases
lead to $0.02<r<0.11$ ($r$ is tensor-scalar ratio) and $N\simeq50 $ case leads
to $n_s\simeq 0.96$ ($n_s$ is spectral index). These constraints of
perturbation parameters are agree with Planck and WMAP9 data. For logamediate
model, where the scale factor expands as: $a(t)=a_0 \exp(a[\ln t]^{\lambda})$
($\lambda >1, A>0$), $N\geq 200$ and $\lambda=2$ cases lead to interesting
agreement with observational data.


title: Firewalls, smoke and mirrors

abstract:
  The radiation emitted by a black hole (BH) during its evaporation has to have
some degree of quantum coherence to accommodate a unitary time evolution. We
parametrize the degree of coherence by the number of coherently emitted
particles $N_{coh}$ and show that it is severely constrained by the equivalence
principle. We discuss, in this context, the fate of a shell of matter that
falls into a Schwarzschild BH. Two points of view are considered, that of a
stationary external observer and that of the shell itself. From the perspective
of the shell, the near-horizon region has an energy density proportional to
$N_{coh}^2$ in Schwarzschild units. So, if $N_{coh}$ is parameterically larger
than the square root of the BH entropy $S_{BH}^ {1/2}$, a firewall or more
generally a "wall of smoke" forms and the equivalence principle is violated
while the BH is still semiclassical. To have a degree of coherence that is
parametrically smaller than $S_{BH}^{1/2}$, one has to introduce a new
sub-Planckian gravitational length scale, which likely also violates the
equivalence principle. And so our previously proposed model which has
$N_{coh}=S_{BH}^{1/2}$ is singled out. From the external-observer perspective,
we find that the time it takes for the information about the state of the shell
to get re-emitted from the BH is inversely proportional to $N_{coh}$. When the
rate of information release becomes order unity, the semiclassical
approximation starts to break down and the BH becomes a perfect reflecting
information mirror.


title: Fluid sphere: stability problem and dimensional constraint

abstract:
  We study different dimensional fluids inspired by noncommutative geometry
which admit conformal Killing vectors. The solutions of the Einstein field
equations examined specifically for five different set of spacetime. We
calculate the active gravitational mass and impose stability conditions of the
fluid sphere. The analysis thus carried out immediately indicates that at
$4$-dimension only one can get a stable configuration for any spherically
symmetric stellar system and any other dimensions, lower or higher, becomes
untenable as far as the stability of a system is concerned.


title: M-estimation in multistage sampling procedures

abstract:
  Multi-stage (designed) procedures, obtained by splitting the sampling budget
suitably across stages, and designing the sampling at a particular stage based
on information about the parameter obtained from previous stages, are often
advantageous from the perspective of precise inference. We develop a generic
framework for M-estimation in a multistage setting and apply empirical process
techniques to develop limit theorems that describe the large sample behavior of
the resulting M-estimates. Applications to change-point estimation, inverse
isotonic regression, classification and mode estimation are provided: it is
typically seen that the multistage procedure accentuates the efficiency of the
M-estimates by accelerating the rate of convergence, relative to one-stage
procedures. The step-by-step process induces dependence across stages and
complicates the analysis in such problems, which we address through careful
conditioning arguments.


title: Slant-gap plasmonic nanoantenna for optical chirality enhancement

abstract:
  We present a new design of plasmonic nanoantenna with a slant gap for optical
chirality engineering. At resonance, the slant gap provides highly enhanced
electric field parallel to external magnetic field with a phase delay of 90
degree, resulting in enhanced optical chirality. We show by numerical
simulations that upon linearly polarized excitation our achiral nanoantenna can
generate near field with enhanced optical chirality that can be tuned by the
slant angle and resonance condition. Our design can be easily realized and may
find applications in circular dichroism enhancement.


title: Irradiated brown dwarfs

abstract:
  We have observed the post common envelope binary WD0137-349 in the near
infrared $J$, $H$ and $K$ bands and have determined that the photometry varies
on the system period (116 min). The amplitude of the variability increases with
increasing wavelength, indicating that the brown dwarf in the system is likely
being irradiated by its 16500 K white dwarf companion. The effect of the
(primarily) UV irradiation on the brown dwarf atmosphere is unknown, but it is
possible that stratospheric hazes are formed. It is also possible that the
brown dwarf (an L-T transition object) itself is variable due to patchy cloud
cover. Both these scenarios are discussed, and suggestions for further study
are made.


title: BigDataBench: a Big Data Benchmark Suite from Internet Services

abstract:
  As architecture, systems, and data management communities pay greater
attention to innovative big data systems and architectures, the pressure of
benchmarking and evaluating these systems rises. Considering the broad use of
big data systems, big data benchmarks must include diversity of data and
workloads. Most of the state-of-the-art big data benchmarking efforts target
evaluating specific types of applications or system software stacks, and hence
they are not qualified for serving the purposes mentioned above. This paper
presents our joint research efforts on this issue with several industrial
partners. Our big data benchmark suite BigDataBench not only covers broad
application scenarios, but also includes diverse and representative data sets.
BigDataBench is publicly available from http://prof.ict.ac.cn/BigDataBench .
Also, we comprehensively characterize 19 big data workloads included in
BigDataBench with varying data inputs. On a typical state-of-practice
processor, Intel Xeon E5645, we have the following observations: First, in
comparison with the traditional benchmarks: including PARSEC, HPCC, and
SPECCPU, big data applications have very low operation intensity; Second, the
volume of data input has non-negligible impact on micro-architecture
characteristics, which may impose challenges for simulation-based big data
architecture research; Last but not least, corroborating the observations in
CloudSuite and DCBench (which use smaller data inputs), we find that the
numbers of L1 instruction cache misses per 1000 instructions of the big data
applications are higher than in the traditional benchmarks; also, we find that
L3 caches are effective for the big data applications, corroborating the
observation in DCBench.


title: Representations of reductive normal algebraic monoids

abstract:
  The rational representation theory of a reductive normal algebraic monoid
(with one-dimensional center) forms a highest weight category, in the sense of
Cline, Parshall, and Scott. This is a fundamental fact about the representation
theory of reductive normal algebraic monoids. We survey how this result was
obtained, and treat some natural examples coming from classical groups.


title:
Zeros of large degree Vorob'ev-Yablonski polynomials via a Hankel
  determinant identity

abstract:
  In the present paper we derive a new Hankel determinant representation for
the square of the Vorob'ev-Yablonski polynomial
$\mathcal{Q}_n(x),x\in\mathbb{C}$. These polynomials are the major ingredients
in the construction of rational solutions to the second Painlev\'e equation
$u_{xx}=xu+2u^3+\alpha$. As an application of the new identity, we study the
zero distribution of $\mathcal{Q}_n(x)$ as $n\rightarrow\infty$ by
asymptotically analyzing a certain collection of (pseudo) orthogonal
polynomials connected to the aforementioned Hankel determinant. Our approach
reproduces recently obtained results in the same context by Buckingham and
Miller \cite{BM}, which used the Jimbo-Miwa Lax representation of PII equation
and the asymptotical analysis thereof.


title: Existence of slices in a tame context

abstract:
  We study the ramification theory for actions involving group schemes,
focusing on the tame ramification. We consider the notion of tame quotient
stack introduced in [AOV] and the one of tame action introduced in [CEPT]. We
establish a local Slice theorem for unramified actions and after proving some
interesting lifting properties for linearly reductive group schemes, we
establish a Slice theorem for actions by commutative group schemes inducing
tame quotient stacks. Roughly speaking, we show that these actions are induced
from an action of an extension of the inertia group on a finitely presented
flat neighborhood. We finally consider the notion of tame action and determine
how this notion is related to the one of tame quotient stack previously
considered.


title:
The magnetic penetration depth influenced by the proximity to the
  surface

abstract:
  The effect of smooth inhomogeneities near a superconductor boundary on the
magnetic penetration depth $\lambda$ is studied with emphasis on the
proximity-induced spatial dependence of the Cooper pair amplitude. The
influence of surface pair breaking or pair formation on $\lambda$ is described
within the Ginzburg-Landau theory, with no model assumptions, for both strongly
type-II and strongly type-I homogeneous superconductors. Generic values of
$\lambda$, which can differ greatly from the London penetration depth, are
identified and demonstrated to be induced by large-scale inhomogeneities, when
superconductivity is strongly suppressed on the surface.


title:
Ab initio quasiparticle bandstructure of ABA and ABC-stacked graphene
  trilayers

abstract:
  We obtain the quasiparticle band structure of ABA and ABC-stacked graphene
trilayers through ab initio density functional theory (DFT) and many-body
quasiparticle calculations within the GW approximation. To interpret our
results, we fit the DFT and GW $\pi$ bands to a low energy tight-binding model,
which is found to reproduce very well the observed features near the K point.
The values of the extracted hopping parameters are reported and compared with
available theoretical and experimental data. For both stackings, the self
energy corrections lead to a renormalization of the Fermi velocity, an effect
also observed in previous calculations on monolayer graphene. They also
increase the separation between the higher energy bands, which is proportional
to the nearest neighbor interlayer hopping parameter $\gamma_1$. Both features
are brought to closer agreement with experiment through the self energy
corrections. Finally, other effects, such as trigonal warping, electron-hole
asymmetry and energy gaps are discussed in terms of the associated parameters.


title:
Proton decay and new contribution to neutrino-less double beta decay in
  SO(10) with low-mass Z-prime boson, observable n-nbar oscillation, lepton
  flavor violation, and rare kaon decay

abstract:
  Conventionally for observable $n-{\bar n}$ oscillation through Pati-Salam
intermediate gauge symmetry in $SO(10)$, the canonical seesaw mechanism is also
constrained by $M_R \sim M_C \le 10^6$ GeV which yields light neutrino masses
much larger than the neutrino oscillation data. Recently, this difficulty has
been evaded via inverse seesaw mechanism, but with proton lifetime far beyond
the experimentally accessible limits. In the present work, adopting the view
that we may have only a TeV scale $Z^{\prime}$ gauge boson, we show how a class
of non-SUSY $SO(10)$ models allow experimentally verifiable proton lifetime and
the new contributions to neutrinoless double beta decay in the $W_L-W_L$
channel, lepton flavor violating branching ratios, observable $n-{\bar n}$
oscillation, and lepto-quark gauge boson mediated rare kaon decays. The
occurrence of Pati-Salam gauge symmetry with unbroken D-parity and two gauge
couplings at the highest intermediate scale guarantees precision unification in
such models. This symmetry also ensures vanishing GUT threshold uncertainy on
$\sin^2\theta_W$ or on the highest intermediate scale. Although the proton
lifetime prediction is brought closer to the ongoing search limits with GUT
threshold effects in the minimal model, no such effects are needed in a
non-minimal model. We derive a new analytic expression for the $0\nu\beta\beta$
decay half-life and show how the existing experimental limits impose the lower
bound on the lightest of the three heavy sterile neutrino masses, $M_{S_1}\ge
14\pm 4$ GeV. We also derive a new lower bound on the lepto-quark gauge boson
mass mediating rare kaon decay, $M_{\rm lepto} \ge (1.53{\pm 0.06})\times 10^6$
GeV. The $n-{\bar n}$ mixing times are predicted in the range$\tau_{n-{\bar
n}}\simeq 10^8-10^{13}$ sec.


title:
Transparency of an instantaneously created electron-positron-photon
  plasma

abstract:
  The problem of the expansion of a relativistic plasma generated when a large
amount of energy is released in a small volume has been considered by many
authors. We use the analytical solution of Bisnovatyi-Kogan and Murzina (1995)
for the spherically symmetric relativistic expansion. The light-curves and the
spectra from transparency of an electron-positron-photon plasma are obtained.
We compare our results with the work of Goodman (1986).


title: Recent progress in the effective string theory description of LGTs

abstract:
  In presence of a static pair of sources, the spectrum of low-lying states of
any confining gauge theory in D space-time dimensions is described, at large
source separations, by an effective string theory. Recently two important
advances improved our understanding of this effective theory. First, it was
realized that the form of the effective action is strongly constrained by the
requirement of the Lorentz invariance of the gauge theory, which is
spontaneously broken by the formation of a long confining flux tube in the
vacuum. This constraint is strong enough to fix uniquely the first few
subleading terms of the action. Second, it has been realized that the first of
these allowed terms - a quartic polynomial in the field derivatives - is
exactly the composite field $T\bar{T}$, built with the chiral components, $T$
and $\bar{T}$, of the energy-momentum tensor of the 2d QFT describing the
infrared limit of the effective string. This irrelevant perturbation is quantum
integrable and yields, through the thermodynamic Bethe Ansatz (TBA), the energy
levels of the string which exactly coincide with the Nambu-Goto spectrum. In
this talk we first review the general implications of these two results and
then, as a test of the power of these methods, use them to construct the first
few boundary corrections to the effective string action.


title: Ultraviolet and visible range plasmonics of a topological insulator

abstract:
  The development of metamaterials, data processing circuits and sensors for
the visible and UV parts of the spectrum is hampered by the lack of low-loss
media supporting plasmonic excitations and drives the intense search for
plasmonic materials beyond noble metals. By studying plasmonic nanostructures
fabricated on the surface of topological insulator
$\mbox{Bi}_{1.5}\mbox{Sb}_{0.5}\mbox{Te}_{1.8}\mbox{Se}_{1.2}$ we found that it
is orders of magnitude better plasmonic material than gold and silver in the
blue-UV range. Metamaterial fabricated from
$\mbox{Bi}_{1.5}\mbox{Sb}_{0.5}\mbox{Te}_{1.8}\mbox{Se}_{1.2}$ show plasmonic
resonances from 350 nm to 550 nm while surface gratings exhibit
cathodoluminescent peaks from 230 nm to 1050 nm. The negative permittivity
underpinning plasmonic response is attributed to the combination of bulk
interband transitions and surface contribution of the topologically protected
states. The importance of our result is in the identification of new mechanisms
of negative permittivity in semiconductors where visible-range plasmonics can
be directly integrated with electronics.


title: Pressure effects on the superconducting critical temperature of Li2B2

abstract:
  We present the structural, electronic and superconducting properties of Li2B2
under pressure within the framework of the density functional theory. The
structural parameters, electronic band structure, phonon frequency of the E2g
phonon mode and superconducting critical temperature Tc were calculated for
pressures up to 20 GPa. We predicted that the superconducting critical
temperature of Li2B2 is about 11 K and this decreases as pressure increases. We
found that even though the lattice dynamics of the E2g phonon mode is similar
to MgB2, the reduction of the {\sigma}-band density of states at Fermi level
and the raising of the E2g phonon frequency with pressure were determinant to
decrease {\lambda} and consequently Tc.


title:
About a class of truncated operators represented viua Schauder bases
  with applications

abstract:
  This research investigates the relations between the fixed points of
asymptotically contractive operators defined on complete liner metric spaces,
in general, and in separable Hilbert spaces in particular and their obtained
truncations of the expansions of such operators by using Schauder bases.


title:
Influence of Non-Markovian Dynamics in Thermal-Equilibrium
  Uncertainty-Relations

abstract:
  Contrary to the conventional wisdom that deviations from standard
thermodynamics originate from the strong coupling to the bath, it is shown that
in quantum mechanics, these deviations originate from the uncertainty principle
and are supported by the non-Markovian character of the dynamics. Specifically,
it is shown that the lower bound of the dispersion of the total energy of the
system, imposed by the uncertainty principle, is dominated by the bath power
spectrum and therefore, quantum mechanics inhibits the system
thermal-equilibrium-state from being described by the canonical Boltzmann's
distribution. We show that for a wide class of systems, systems interacting via
central forces with pairwise-self-interacting environments, this general
observation is in sharp contrast to the classical case, for which the thermal
equilibrium distribution, irrespective of the interaction strength, is
\emph{exactly} characterized by the canonical Boltzmann distribution and
therefore, no dependence on the bath power spectrum is present. We define an
\emph{effective coupling} to the environment that depends on all energy scales
in the system and reservoir interaction. Sample computations in regimes
predicted by this effective coupling are demonstrated. For example, for the
case of strong effective coupling, deviations from standard thermodynamics are
present and, for the case of weak effective coupling, quantum features such as
stationary entanglement are possible at high temperatures.


title: Ionic ammonia ice

abstract:
  We report experimental and theoretical evidence that solid molecular ammonia
becomes unstable at room temperature and high pressures and transforms into an
ionic crystalline form. This material has been characterised in both
hydrogenated NH3 and deuterated ND3 ammonia samples up to about 180 and 200
GPa, respectively, by infrared absorption, Raman spectroscopy and x-ray
diffraction. The presence of a new, strong IR absorption band centered at 2500
cm-1 in NH3 (1900 cm-1 in ND3) signals the ionization of ammonia molecules into
NH2- and NH4+ ions, in line with previous theoretical predictions. We find
experimental evidence for a coexistence of two crystalline ionic forms, which
our ab-initio structure searches predict to be the most stable at the relevant
pressures. The ionic crystalline form of ammonia is stable at low temperatures,
which contrasts with the behaviour of water in which no equivalent crystalline
ionic phase has been found.


title: Mode-coupling theory for multiple decay channels

abstract:
  We investigate the properties of a class of mode-coupling equations for the
glass transition where the density mode decays into multiple relaxation
channels. We prove the existence and uniqueness of the solutions for Newtonian
as well as Brownian dynamics and demonstrate that they fulfill the requirements
of correlation functions, in the latter case the solutions are purely
relaxational. Furthermore, we construct an effective mode-coupling functional
which allows to map the theory to the case of a single decay channel, such that
the covariance principle found for the mode-coupling theory for simple liquids
is properly generalized. This in turn allows establishing the maximum theorem
stating that long-time limits of mode-coupling solutions can be calculated as
maximal solutions of a fixed-point equation without relying on the dynamic
solutions.