title:
Three-dimensional Iroshnikov-Kraichnan turbulence in a mean magnetic
  field

abstract:
  Forced, weak MHD turbulence with guide field is shown to adopt different
regimes, depending on the magnetic excess of the large forced scales. When the
magnetic excess is large enough, the classical perpendicular cascade with $5/3$
scaling is obtained, while when equipartition is imposed, an isotropic $3/2$
scaling appears in all directions with respect to the mean field
(\cite{2010PhRvE..82b6406G} or GM10). We show here that the $3/2$ scaling of
the GM10 regime is not ruled by a small-scale cross-helicity cascade, and
propose that it is a 3D extension of a perpendicular weak Iroshnikov-Kraichnan
(IK) cascade. We analyze in detail the structure functions in real space and
show that they closely follow the critical balance relation both in the local
frame and the global frame: we show that there is no contradiction between this
and the isotropic $3/2$ scaling of the spectra. We propose a scenario
explaining the spectral structure of the GM10 regime, that starts with a
perpendicular weak IK cascade and extends to 3D by using quasi-resonant
couplings. The quasi-resonance condition happens to reduce the energy flux in
the same way as is done in the weak perpendicular cascade, so leading to a
$3/2$ scaling in all directions. We discuss the possible applications of these
findings to solar wind turbulence.


title: Perturbations of frames

abstract:
  In this paper, we give some sufficient conditions under which perturbations
preserve Hilbert frames and near-Riesz bases. Similar results are also extended
to frame sequences, Riesz sequences and Schauder frames. It is worth mentioning
that some of our perturbation conditions are quite different from those used in
the previous literatures on this topic.


title: Chiral spin liquid in a frustrated anisotropic kagome Heisenberg model

abstract:
  Kalmeyer-Laughlin (KL) chiral spin liquid (CSL) is a type of quantum spin
liquid without time-reversal symmetry, and it is considered as the parent state
of an exotic type of superconductivity--anyon superconductor. Such exotic state
has been sought for more than twenty years, however it remains unclear whether
it can exist in realistic system where time-reversal symmetry is breaking
(T-breaking) spontaneously. By using the density matrix renormalization group,
we show that KL CSL exists in a frustrated anisotropic kagome Heisenberg model
(KHM), which has spontaneously T-breaking. We find that our model has two
topological degenerate ground states, which exhibit non-vanishing scalar
chirality order and are protected by finite excitation gap. Further, we
identify this state as KL CSL by the characteristic edge conformal field theory
from the entanglement spectrum and the quasiparticles braiding statistics
extracted from the modular matrix. We also study how this CSL phase evolves as
the system approaches the nearest neighbor KHM.


title: Matters on a moving brane

abstract:
  A novel generalisation of the Dirac-Born-Infeld string scenario is described.
It is shown that matter residing on the moving brane is dark and has the
so-called disformal coupling to gravity. This gives rise to cosmologies where
dark matter stems from the oscillations of the open strings along the brane and
the transverse oscillations result in dark energy. Furthermore, due to a new
screening mechanism that conceals the fifth force from local experiments, one
may even entertain the possibility that the visible sector is also moving along
the extra dimensions.


title: Type-II defects in the super-Liouville theory

abstract:
  The introduction of type-II defects is discussed under the Lagrangian
formalism and Lax representation for the N=1 super-Liouville model. We derive a
new kind of super-Backlund transformation for the model and show explicitly the
conservation of the modified energy and momentum, as well as supercharge.


title: Wireless network control of interacting Rydberg atoms

abstract:
  We identify a relation between the dynamics of ultracold Rydberg gases in
which atoms experience a strong dipole blockade and spontaneous emission, and a
stochastic process that models certain wireless random-access networks. We then
transfer insights and techniques initially developed for these wireless
networks to the realm of Rydberg gases, and explain how the Rydberg gas can be
driven into crystal formations using our understanding of wireless networks.
Finally, we propose a method to determine Rabi frequencies (laser intensities)
such that particles in the Rydberg gas are excited with specified target
excitation probabilities, providing control over mixed-state populations.


title:
Stereo-SCIDAR: Optical turbulence profiling with high sensitivity using
  a modified SCIDAR instrument

abstract:
  The next generation of adaptive optics (AO) systems will require tomographic
reconstruction techniques to map the optical refractive index fluctuations,
generated by the atmospheric turbulence, along the line of sight to the
astronomical target. These systems can be enhanced with data from an external
atmospheric profiler. This is important for Extremely Large Telescope scale
tomography. Here we propose a new instrument which utilises the generalised
SCIntillation Detection And Ranging (SCIDAR) technique to allow high
sensitivity vertical profiles of the atmospheric optical turbulence and wind
velocity profile above astronomical observatories. The new approach, which we
refer to as 'Stereo-SCIDAR', uses a stereoscopic system with the scintillation
pattern from each star of a double-star target incident on a separate detector.
Separating the pupil images for each star has several advantages including:
increased magnitude difference tolerance for the target stars; negating the
need for re-calibration due to the normalisation errors usually associated with
SCIDAR; an increase of at least a factor of two in the signal-to-noise ratio of
the cross-covariance function and hence the profile for equal magnitude target
stars and up to a factor of 16 improvement for targets of 3 magnitudes
difference; and easier real-time reconstruction of the wind-velocity profile.
Theoretical response functions are calculated for the instrument, and the
performance is investigated using a Monte-Carlo simulation. The technique is
demonstrated using data recorded at the 2.5 m Nordic Optical Telescope and the
1.0 m Jacobus Kapteyn Telescope, both on La Palma.


title: Almost-Killing conserved currents: a general mass function

abstract:
  A new class of conserved currents, describing non-gravitational
energy-momentum density, is presented. The proposed currents do not require the
existence of a (timelike) Killing vector, and are not restricted to spherically
symmetric spacetimes (or similar ones, in which the Kodama vector can be
defined). They are based instead on almost-Killing vectors, which could in
principle be defined on generic spacetimes. We provide local arguments, based
on energy density profiles in highly simplified (stationary, rigidly-rotating)
star models, which confirm the physical interest of these 'almost-Killing
currents'. A mass function is defined in this way for the spherical case,
qualitatively different from the Hern\'andez-Misner mass function. An elliptic
equation determining the new mass function is derived for the Tolman-Bondi
spherically symmetric dust metrics, including a simple solution for the
Oppenheimer-Schneider collapse. The equations for the non-symmetric case are
shown to be of a mixed elliptic-hyperbolic nature.


title:
Galilean invariance in confined quantum systems: Implications on
  spectral gaps, superfluid flow, and periodic order

abstract:
  Galilean invariance leaves its imprint on the energy spectrum and eigenstates
of $N$ quantum particles, bosons or fermions, confined in a bounded domain. It
endows the spectrum with a recurrent structure which in capillaries or
elongated traps of length $L$ and cross-section area $s_\perp$ leads to
spectral gaps $n^2h^2s_\perp\rho/(2mL)$ at wavenumbers $2n\pi s_\perp\rho$,
where $\rho$ is the number density and $m$ is the particle mass. In zero
temperature superfluids, in toroidal geometries, it causes the quantization of
the flow velocity with the quantum $h/(mL)$ or that of the circulation along
the toroid with the known quantum $h/m$. Adding a "friction" potential which
breaks Galilean invariance, the Hamiltonian can have a superfluid ground state
at low flow velocities but not above a critical velocity which may be different
from the velocity of sound. In the limit of infinite $N$ and $L$, if
$N/L=s_\perp\rho$ is kept fixed, translation invariance is broken, the center
of mass has a periodic distribution, while superfluidity persists at low flow
velocities. This conclusion holds for the Lieb-Liniger model.

categories: cond-mat.quant-gas math-ph math.MP quant-ph


title:
Exoplanetary searches with gravitational microlensing: polarization
  issues

abstract:
  There are different methods for finding exoplanets such as radial spectral
shifts, astrometrical measurements, transits, timing etc. Gravitational
microlensing (including pixel-lensing) is among the most promising techniques
with the potentiality of detecting Earth-like planets at distances about a few
astronomical units from their host star or near the so-called snow line with a
temperature in the range $0-100^0$ C on a solid surface of an exoplanet. We
emphasize the importance of polarization measurements which can help to resolve
degeneracies in theoretical models. In particular, the polarization angle could
give additional information about the relative position of the lens with
respect to the source.

categories: astro-ph.SR astro-ph.EP astro-ph.GA gr-qc


title: Proton radius puzzle and quantum gravity at the Fermi scale

abstract:
  We show how the "proton radius puzzle" emerging from the measurement of the
Lamb shift in muonic hydrogen may be solved by means of a binding energy
contribution due to an effective Yukawian gravitational potential related to
charged weak interactions. The residual discrepancy from the experimental
result should be mainly attributable to the need for the experimental
determination of the gravitational radius of the proton. The absence of an
analogous contribution in the Lamb shift of electronic hydrogen should imply
the existence of generation-dependent interactions, corroborating previous
proposals. Muonic hydrogen plays a crucial role to test possible scenarios for
a gravitoweak unification, with weak interactions seen as manifestations of
quantum gravity effects at the Fermi scale.


title:
Features of the mass transfer in magnetic cataclysmic variables with
  fast-rotating white dwarfs

abstract:
  The flow structure in magnetic cataclysmic variables was investigated taking
into account the effects of strong magnetic field and fast rotation of the
white dwarf. We modeled the AE Aqr system as a unique object that has the
rotation period of the white dwarf is about 1000 times shorter than the orbital
period of the binary system. Observations show that in spite of fast rotation
of the white dwarf some part of the stream from the inner Lagrange point comes
into the Roche lobe region. We analyzed possible mechanisms preventing material
to outflow from the system.


title: A little quantum help for cosmic censorship and a step beyond all that

abstract:
  The hypothesis of cosmic censorship (CCH) plays a crucial role in classical
general relativity, namely to ensure that naked singularities would never
emerge, since it predicts that whenever a singularity is formed an event
horizon would always develop around it as well, to prevent the former from
interacting directly with the rest of the Universe. Should this not be so,
naked singularities could eventually form, in which case phenomena beyond our
understanding and ability to predict could occur, since at the vicinity of the
singularity both predictability and determinism break down even at the
classical (e.g. non-quantum) level. More than 40 years after it was proposed,
the validity of the hypothesis remains an open question. We reconsider CCH in
both its weak and strong version, concerning point-like singularities, with
respect to the provisions of Heisenberg's uncertainty principle. We argue that
the shielding of the singularities from observers at infinity by an event
horizon is also quantum mechanically favored, but ultimately it seems more
appropriate to accept that singularities never actually form in the usual
sense, thus no naked singularity danger exists in the first place.


title:
Capillary attraction induced collapse of colloidal monolayers at fluid
  interfaces

abstract:
  We investigate the evolution of a system of colloidal particles, trapped at a
fluid interface and interacting via capillary attraction, as function of the
range of the capillary interaction and temperature. We address the collapse of
an initially homogeneous particle distribution and of a radially symmetric
(disk--shaped) distribution of finite size, both theoretically by using a
perturbative approach inspired by cosmological models and numerically by means
of Brownian dynamics (BD) and dynamical density functional theory (DDFT). The
results are summarized in a "dynamical phase diagram", describing a smooth
crossover from collective (gravitational-like) collapse to local
(spinodal-like) clustering. In this crossover region, the evolution exhibits a
peculiar shock wave behavior at the outer rim of the contracting, disk-shaped
distribution.


title: Isomorphic chain complexes of Hamiltonian dynamics on tori

abstract:
  In this work we construct for a given smooth, generic Hamiltonian $H :
\mathbb{S}^1\times\mathbb{T}^n \longrightarrow \mathbb{R}$ on the torus a chain
isomorphism $ \Phi_* : \big(C_*(H),\partial^M_*\big) \longrightarrow
\big(C_*(H),\partial^F_*\big)$ between the Morse complex of the Hamiltonian
action $A_H$ on the free loop space of the torus $\Lambda_0(\mathbb{T}^n)$ and
the Floer complex. Though both complexes are generated by the critical points
of $A_H$, their boundary operators differ. Therefore the construction of $\Phi$
is based on counting the moduli spaces of hybrid type solutions which involves
stating a new non-Lagrangian boundary value problem for Cauchy-Riemann type
operators not yet studied in Floer theory.


title:
A catalog of rotational and radial velocities for evolved stars V.
  Southern stars

abstract:
  Rotational and radial velocities have been measured for 1589 evolved stars of
spectral types F, G and K and luminosity classes IV, III, II and Ib, based on
observations carried out with the CORAVEL spectrometers. The precision in
radial velocity is better than 0.30 km/s per observation, whereas rotational
velocity uncertainties are typically 1.0 km/s for subgiants and giants and 2.0
km/s for class II giants and Ib supergiants.


title: Factorization of 5D super Yang-Mills on $Y^{p,q}$ spaces

abstract:
  We continue our study on the partition function for 5D supersymmetric
Yang-Mills theory on toric Sasaki-Einstein $Y^{p,q}$ manifolds. Previously,
using the localisation technique we have computed the perturbative part of the
partition function. In this work we show how the perturbative part factorises
into four pieces, each corresponding to the perturbative answer of the same
theory on $\mathbb{R}^4 \times S^1$. This allows us to identify the equivariant
parameters and to conjecture the full partition functions (including the
instanton contributions) for $Y^{p,q}$ spaces. The conjectured partition
function receives contributions only from singular contact instantons supported
along the closed Reeb orbits. At the moment we are not able to prove this fact
from the first principles.


title:
Lindblad equation approach for the full counting statistics of work and
  heat in driven quantum systems

abstract:
  We formulate the general approach based on the Lindblad equation to calculate
the full counting statistics of work and heat produced by driven quantum
systems weakly coupled with a Markovian thermal bath. The approach can be
applied to a wide class of dissipative quantum systems driven by an arbitrary
force protocol. We show the validity of general fluctuation relations and
consider several generic examples. The possibilities of using calorimetric
measurements to test the presence of coherence and entanglement in the open
quantum systems are discussed.


title: Fresnel diffraction patterns as accelerating beams

abstract:
  We demonstrate that beams originating from Fresnel diffraction patterns are
self-accelerating in free space. In addition to accelerating and self-healing,
they also exhibit parabolic deceleration property, which is in stark contrast
to other accelerating beams. We find that the trajectory of Fresnel paraxial
accelerating beams is similar to that of nonparaxial Weber beams. Decelerating
and accelerating regions are separated by a critical propagation distance, at
which no acceleration is present. During deceleration, the Fresnel diffraction
beams undergo self-smoothing, in which oscillations of the diffracted waves
gradually focus and smooth out at the critical distance.


title: On the power of randomization in network interdiction

abstract:
  Network interdiction can be viewed as a game between two players, an
"interdictor" and a "flow player". The flow player wishes to send as much
material as possible through a network, while the interdictor attempts to
minimize the amount of transported material by removing a certain number of
arcs, say $\Gamma$ arcs. We introduce the randomized network interdiction
problem that allows the interdictor to use randomness to select arcs to be
removed. We model the problem in two different ways: arc-based and path-based
formulations, depending on whether flows are defined on arcs or paths,
respectively. We present insights into the modeling power, complexity, and
approximability of both formulations. In particular, we prove that
$Z_{\text{NI}}/Z_{\text{RNI}}\leq \Gamma+1$,
$Z_{\text{NI}}/Z_{\text{RNI}}^{\text{Path}}\leq \Gamma+1$,
$Z_{\text{RNI}}/Z_{\text{RNI}}^{\text{Path}}\leq \Gamma$, where
$Z_{\text{NI}}$, $Z_{\text{RNI}}$, and $Z_{\text{RNI}}^{\text{Path}}$ are the
optimal values of the network interdiction problem and its randomized versions
in arc-based and path-based formulations, respectively. We also show that these
bounds are tight. We show that it is NP-hard to compute the values
$Z_{\text{RNI}}$ and $Z_{\text{RNI}}^{\text{Path}}$ for a general $\Gamma$, but
they are computable in polynomial time when $\Gamma=1$. Further, we provide a
$(\Gamma+1)$-approximation for $Z_{\text{NI}}$, a $\Gamma$-approximation for
$Z_{\text{RNI}}$, and a $\big(1+\lfloor \Gamma/2\rfloor \cdot \lceil
\Gamma/2\rceil/(\Gamma+1)\big)$-approximation for
$Z_{\text{RNI}}^{\text{Path}}$.


title: Planet formation from the ejecta of common envelopes

abstract:
  The close binary system NN Serpentis must have gone through a common envelope
phase before the formation of its white dwarf. During this phase, a substantial
amount of mass was lost from the envelope. The recently detected orbits of
circumbinary planets are likely inconsistent with planet formation before the
mass loss.We explore whether new planets may have formed from the ejecta of the
common envelope and derive the expected planetary mass as a function of
radius.We employed the Kashi & Soker model to estimate the amount of mass that
is retained during the ejection event and inferred the properties of the
resulting disk from the conservation of mass and angular momentum. The
resulting planetary masses were estimated from models with and without
radiative feedback. We show that the observed planetary masses can be
reproduced for appropriate model parameters. Photoheating can stabilize the
disks in the interior, potentially explaining the observed planetary orbits on
scales of a few AU. We compare the expected mass scale of planets for 11
additional systems with observational results and find hints of two
populations, one consistent with planet formation from the ejecta of common
envelopes and the other a separate population that may have formed earlier. The
formation of the observed planets from the ejecta of common envelopes seems
feasible. The model proposed here can be tested through refined observations of
additional post-common envelope systems. While it appears observationally
challenging to distinguish between the accretion on pre-existing planets and
their growth from new fragments, it may be possible to further constrain the
properties of the protoplanetary disk through additional observations of
current planetary candidates and post-common envelope binary systems.


title:
The Congruence Subgroup Problem for the Free Metabelian Group on two
  generators

abstract:
  In this paper we describe the profinite completion of the free solvable group
on m generators of solvability length r>1. Then, we show that for m=r=2, the
free metabelian group on two generators does not have the Congruence Subgroup
Property.


title: Calabi--Yau 3-folds of Borcea--Voisin type and elliptic fibrations

abstract:
  We consider Calabi--Yau 3-folds of Borcea--Voisin type, i.e. Calabi--Yau
3-folds obtained as crepant resolutions of a quotient $(S\times
E)/(\alpha_S\times \alpha_E)$, where $S$ is a K3 surface, $E$ is an elliptic
curve, $\alpha_S\in {\rm Aut} (S)$ and $\alpha_E\in {\rm Aut}(E)$ act on the
period of $S$ and $E$ respectively with order $n=2,3,4,6$. The case $n=2$ is
very classical, the case $n=3$ was recently studied by Rohde, the other cases
are less known. First we construct explicitly a crepant resolution, $X$, of
$(S\times E)/(\alpha_S\times \alpha_E)$ and we compute its Hodge numbers; some
pairs of Hodge numbers we found are new. Then we discuss the presence of
maximal automorphisms and of a point with maximal unipotent monodromy for the
family of $X$. Finally, we describe the map $\mathcal{E}_n: X \rightarrow
S/\alpha_S$ whose generic fiber is isomorphic to $E$.


title:
Bayesian transformation family selection: moving towards a transformed
  Gaussian universe

abstract:
  The problem of transformation selection is thoroughly treated from a Bayesian
perspective. Several families of transformations are considered with a view to
achieving normality: the Box-Cox, the Modulus, the Yeo & Johnson and the Dual
transformation. Markov chain Monte Carlo algorithms have been constructed in
order to sample from the posterior distribution of the transformation parameter
$\lambda_T$ associated with each competing family $T$. We investigate different
approaches to constructing compatible prior distributions for $\lambda_T$ over
alternative transformation families, using a unit-information power-prior
approach and an alternative normal prior with approximate unit-information
interpretation. Selection and discrimination between different transformation
families is attained via posterior model probabilities. We demonstrate the
efficiency of our approach using a variety of simulated datasets. Although
there is no choice of transformation family that can be universally applied to
all problems, empirical evidence suggests that some particular data structures
are best treated by specific transformation families. For example, skewness is
associated with the Box-Cox family while fat-tailed distributions are
efficiently treated using the Modulus transformation.


title:
Possible Contribution to Electron and Positron Fluxes from Pulsars and
  their Nebulae

abstract:
  The AMS-02 experiment confirms the excess of positrons in cosmic rays (CRs)
for energy above 10 GeV with respect to the secondary production of positrons
in the interstellar medium. This is interpreted as evidence of the existence of
a primary source of these particles. Possible candidates are dark matter or
astrophysical sources. In this work we discuss the possible contribution due to
pulsars and their nebulae. Our key assumption is that the primary spectrum of
electrons and positrons at the source is the same of the well known photon
spectrum observed from gamma-rays telescopes. Using a diffusion model in the
Galaxy we propagate the source spectra up to the Solar System. We compare our
results with the recent experiments and with the LIS model


title: Quantum particle in a parabolic lattice in the presence of a gauge field

abstract:
  We analyze the eigenstates of a two-dimensional lattice with additional
harmonic confinement in the presence of an artificial magnetic field. While the
softness of the confinement makes a distinction between bulk and edge states
difficult, the interplay of harmonic potential and lattice leads to a different
classification of states in three energy regions: In the low-energy regime,
where lattice effects are small, all states are transporting topologically
non-trivial states. For large energies above a certain critical value, the
periodic lattice causes localization of all states through a mechanism similar
to Wannier-Stark localization. In the intermediate energy regime transporting,
topologically non- trivial states coexist with topologically trivial
counter-transporting chaotic states. The character of the eigenstates, in
particular their transport properties are studied numerically and are explained
using a semiclassical analysis.


title: Local factors valued in normal domains

abstract:
  We give an exposition of Deligne's theory of local $\epsilon_0$-factors over
fields and discrete valuation rings under the assumption that the theory over
the complex numbers is known. We then employ standard techniques from algebraic
geometry to deduce the theory of local $\epsilon_0$-factors over arbitrary
normal integral schemes.


title:
Controlling multi-wave mixing signals via photonic band gap of
  electromagnetically induced absorption grating in atomic media

abstract:
  We experimentally demonstrate dressed multi-wave mixing (MWM) and the
reflection of the probe beam due to electromagnetically induced absorption
(EIA) grating can coexist in a five-level atomic ensemble. The reflection is
derived from the photonic band gap (PBG) of EIA grating, which is much broader
than the PBG of EIT grating. Therefore, EIA-type PBG can reflect more energy
from probe than EIT-type PBG does, which can effectively affect the MWM signal.
The EIA-type as well as EIT-type PBG can be controlled by multiple parameters
including the frequency detunings, propagation angles and powers of the
involved light fields. Also, the EIA-type PBG by considering both the linear
and third-order nonlinear refractive indices is also investigated. The
theoretical analysis agrees well with the experimental results. This
investigation has potential applications in all-optical communication and
information processing.


title: Quantum analysis of the direct measurement of light waves

abstract:
  In a beautiful experiment performed about a decade ago, Goulielmakis et al.
made a direct measurement of the electric field of light waves [E. Goulielmakis
et al., Science 305, 1267-1269 (2004)]. However, they used a laser source to
produce the light field, whose quantum state has a null expectation value for
the electric field operator, so how was it possible to measure this electric
field? Here we present a quantum treatment for the f:2f interferometer used to
calibrate the carrier-envelope phase of the light pulses in the experiment. We
show how the special nonlinear features of the f:2f interferometer can change
the quantum state of the electromagnetic field inside the laser cavity to a
state with a definite oscillating electric field, explaining how the
"classical" electromagnetic field emerges in the experiment. We discuss that
this experiment was, to our knowledge, the first demonstration of an absolute
coherent superposition of different photon number states in the optical regime.


title: Supernova Bounds on Weinberg's Goldstone Bosons

abstract:
  Recently, Weinberg proposed a scenario where Goldstone bosons may be
masquerading as fractional cosmic neutrinos. We calculate the energy loss rates
through the emission of these Goldstone bosons in a post-collapse supernova
core. Invoking the well established emissivity bound from the Supernova 1987A
observations and simulations, we find that nuclear bremsstrahlung processes can
notably impose a bound on the Goldstone boson coupling to the Standard Model
Higgs, $g$, dependent on the mass of the associated radial field, $m_r$. For
$m_r$ large enough compared with the temperature in the post-collapse supernova
core, our bound is $|g| \lesssim 0.011\, (m_r / 500~{\rm MeV})^2$, very
competitive to that derived from collider experiments.


title: On the topological minimality of unions of planes of arbitrary dimension

abstract:
  In this article we prove the topological minimality of unions of several
almost orthogonal planes of arbitrary dimensions. A particular case was proved
in arXiv:1103.1468, where we proved the Almgren minimality (which is a weaker
property than the topological minimality) of the union of two almost orthogonal
2 dimensional planes. On the one hand, the topological minimality is always
proved by variations of calibration methods, but in this article, we give a
continuous family topological minimal sets, hence calibrations cannot apply.
The advantage of a set being topological minimal (compared to Almgren minimal)
is that its product with $\R^n$ stays topological minimal. This leads also to
finding minimal sets which are unions of non transversal (hence far from almost
orthogonal) planes; On the other hand, regularity for higher dimensional
minimal sets is much less clear than those of dimension 2, hence more efforts
are needed for higher dimensional cases.


title: Adaptive deterministic dyadic grids on spaces of homogeneous type

abstract:
  In the context of spaces of homogeneous type, we develop a method to
deterministically construct dyadic grids, specifically adapted to a given
combinatorial situation. This method is used to estimate vector-valued
operators rearranging martingale difference sequences such as the Haar system.


title: PAMPAC: A Parallel Adaptive Method for Pseudo-Arclength Continuation

abstract:
  Pseudo-arclength continuation is a well-established method for generating a
numerical curve approximating the solution of an underdetermined system of
nonlinear equations. It is an inherently sequential predictor-corrector method
in which new approximate solutions are extrapolated from previously converged
results and then iteratively refined. Convergence of the iterative corrections
is guaranteed only for sufficiently small prediction steps. In high-dimensional
systems, corrector steps are extremely costly to compute and the prediction
step-length must be adapted carefully to avoid failed steps or unnecessarily
slow progress. We describe a parallel method for adapting the step-length
employing several predictor-corrector sequences of different step lengths
computed concurrently. In addition, the algorithm permits intermediate results
of unconverged correction sequences to seed new predictions. This strategy
results in an aggressive optimization of the step length at the cost of
redundancy in the concurrent computation. We present two examples of convoluted
solution curves of high-dimensional systems showing that speed-up by a factor
of two can be attained on a multi-core CPU while a factor of three is
attainable on a small cluster.


title: About the surjectivity of the Wahl map of nodal curves on K3 surfaces

abstract:
  I correct an error in my article arXiv:0911.5474, concerning the
non-surjectivity of the Wahl map of nodal curves on K3 surfaces. I prove that a
modification of the Wahl map is indeed non-surjective for nodal curves with a
low number of nodes, on arbitrary K3 surfaces. Along the way, I also obtain a
lower bound of independent interest for the multiple point Seshadri constants
of K3 surfaces with cyclic Picard group.


title: A product formula for the eigenfunctions of a quartic oscillator

abstract:
  We consider the Schr\"odinger operator on the real line with an even quartic
potential. Our main result is a product formula of the type $\psi_k(x)\psi_k(y)
= \int_{\mathbb{R}} \psi_k(z)\mathcal{K}(x,y,z)dz$ for its eigenfunctions
$\psi_k$. The kernel function $\mathcal{K}$ is given explicitly in terms of the
Airy function $\mathrm{Ai}(x)$, and is positive for appropriate parameter
values. As an application, we obtain a particular asymptotic expansion of the
eigenfunctions $\psi_k$.


title: Generic Power Sum Decompositions and Bounds for the Waring Rank

abstract:
  A notion of open rank, related with generic power sum decompositions of
forms, has recently been introduced in the literature. The main result here is
that the maximum open rank for plane quartics is eight. In particular, this
gives the first example of $n,d$, such that the maximum open rank for degree
$d$ forms that essentially depend on $n$ variables is strictly greater than the
maximum rank. On one hand, the result allows to improve the previously known
bounds on open rank, but on the other hand indicates that such bounds are
likely quite relaxed. Nevertheless, some of the preparatory results are of
independent interest, and still may provide useful information in connection
with the problem of finding the maximum rank for the set of all forms of given
degree and number of variables. For instance, we get that every ternary forms
of degree $d\ge 3$ can be annihilated by the product of $d-1$ pairwise
independent linear forms.


title: On the $B^{*'}\to B$ transition

abstract:
  We present a first $N_{\rm f}=2$ lattice estimate of the hadronic coupling
$g_{12}$ which parametrizes the strong decay of a radially excited $B^*$ meson
into the ground state $B$ meson at zero recoil. We work in the static limit of
Heavy Quark Effective Theory (HQET) and solve a Generalised Eigenvalue Problem
(GEVP), which is necessary for the extraction of excited state properties.
After an extrapolation to the continuum limit and a check of the pion mass
dependence, we obtain $g_{12} = -0.17(4)$.


title:
Memory effects induce structure in social networks with activity-driven
  agents

abstract:
  Activity-driven modeling has been recently proposed as an alternative growth
mechanism for time varying networks, displaying power-law degree distribution
in time-aggregated representation. This approach assumes memoryless agents
developing random connections, thus leading to random networks that fail to
reproduce two-nodes degree correlations and the high clustering coefficient
widely observed in real social networks. In this work we introduce these
missing topological features by accounting for memory effects on the dynamic
evolution of time-aggregated networks. To this end, we propose an
activity-driven network growth model including a triadic-closure step as main
connectivity mechanism. We show that this mechanism provides some of the
fundamental topological features expected for social networks. We derive
analytical results and perform extensive numerical simulations in regimes with
and without population growth. Finally, we present two cases of study, one
comprising face-to-face encounters in a closed gathering, while the other one
from an online social friendship network.


title:
Relative inner amenability, relative property gamma and non-Kazhdan
  groups

abstract:
  Let $H$ be a proper subgroup of a discrete group $G$. We introduce a notion
of relative inner amenability of $H$ in $G$, we prove some equivalent
conditions and provide examples as well as counter-examples. We also discuss
the corresponding relative property gamma for pairs of finite factors $N\subset
M$ and we deduce from this a characterization of discrete, icc groups which do
not have Kazhdan's property (T).


title:
Determining the 7Li(n,gamma) cross section via Coulomb dissociation of
  8Li

abstract:
  The applicability of Coulomb dissociation reactions to determine the cross
section for the inverse neutron capture reaction was explored using the
reaction 8Li(gamma,n)7Li. A 69.5 MeV/nucleon 8Li beam was incident on a Pb
target, and the outgoing neutron and 7Li nucleus were measured in coincidence.
The deduced (n,gamma) excitation function is consistent with data for the
direct capture reaction 7Li(n,gamma)8Li and with low-energy effective field
theory calculations.


title: Maximally incompatible quantum observables

abstract:
  The existence of maximally incompatible quantum observables in the sense of a
minimal joint measurability region is investigated. Employing the universal
quantum cloning device it is argued that only infinite dimensional quantum
systems can accommodate maximal incompatibility. It is then shown that two of
the most common pairs of complementary observables (position and momentum;
number and phase) are maximally incompatible.


title:
A unified proof of inequalities and some new inequalities involving
  Neuman-S\'andor mean

abstract:
  In the paper, by finding linear relations of differences between some means,
the authors supply a unified proof of some double inequalities for bounding
Neuman-S\'andor means in terms of the arithmetic, harmonic, and contra-harmonic
means and discover some new sharp inequalities involving Neuman-S\'andor,
contra-harmonic, root-square, and other means of two positive real numbers.


title:
Cosmic-Ray Neutrinos from the Decay of Long-Lived Particle and the
  Recent IceCube Result

abstract:
  Motivated by the recent IceCube result, we study high energy cosmic-ray
neutrino flux from the decay of a long-lived particle. Because neutrinos are so
transparent, high energy neutrinos produced in the past may also contribute to
the present neutrino flux. We point out that the PeV neutrino events observed
by IceCube may originate in the decay of a particle much heavier than PeV if
its lifetime is shorter than the present cosmic time. It is shown that the mass
of the particle responsible for the IceCube event can be as large as $\sim
10^{10}\ {\rm GeV}$. We also discuss several possibilities to acquire
information about the lifetime of the long-lived particle.


title: Bianchi I Model: An Alternative Way To Model The Presentday Universe

abstract:
  Although the new era of high precision cosmology of the cosmic microwave
background (CMB) radiation improves our knowledge to understand the infant as
well as the presentday Universe, it also leads us to question the main
assumption of the exact isotropy of the CMB. There are two pieces of
observational evidence that hint towards there being no exact isotropy. These
are first the existence of small anisotropy deviations from isotropy of the CMB
radiation and second, the presence of large angle anomalies, although the
existence of these anomalies is currently a huge matter of debate. These hints
are particularly important since isotropy is one of the two main postulates of
the Copernican principle on which the FRW models are built. This almost
isotropic CMB radiation implies that the universe is almost a FRW universe, as
is proved by previous studies.
  Assuming the matter component forms the deviations from isotropy in the CMB
density fluctuations when matter and radiation decouples, we here attempt to
find possible constraints on the FRW type scale and Hubble parameter by using
the Bianchi type I (BI) anisotropic model which is asymptotically equivalent to
the standard FRW. To obtain constraints on such an anisotropic model, we derive
average and late-time shear values that come from the anisotropy upper limits
of the recent Planck data based on a model independent shear parameter of
Maartens et al. (1995a,b) and from the theoretical consistency relation. These
constraints lead us to obtain a BI model which becomes an almost-FRW model in
time, and which is consistent with the latest observational data of the CMB.


title: New conserved structural fields for supercooled liquids

abstract:
  By considering Voronoi tessellations of the configurations of a fluid, we
propose two new conserved fields, which provide structural information not
fully accounted for by the usual 2-point density field fluctuations (structure
factor). One of these fields is scalar and associated to the Voronoi cell
volumes, whereas the other one, termed the "geometrical polarisation", is
vectorial, related to the very local anisotropy of the configurations. We study
the static and dynamical properties of these fields in the supercooled regime
of a model glass-forming liquid. We show in particular that the geometrical
polarisation is both statically correlated to the force field and contrary to
it develops a plateau regime when the temperature is lowered. We attribute this
behaviour to the microsopic disorder of the underlying inherent structures (IS)
which dictate the dynamics on time scales larger than the true microscopic
time, in the strong supercooled regime. In this respect, this work raises the
issue of to what extent the inter IS dynamics, intrinsically anisotropic and
collective (cf. T.B. Schr{\o}der et al. {\it J. of Chem. Phys.}, {\bf 112},
9834 (2000)), could be related to their polarisation field.


title: Building An Information System for a Distributed Testbed

abstract:
  This paper describes an information system designed to support the large
volume of monitoring information generated by a distributed testbed. This
monitoring information is produced by several subsystems and consists of status
and performance data that needs to be federated, distributed, and stored in a
timely and easy to use manner. Our approach differs from existing approaches
because it federates and distributes information at a low architectural level
via messaging; a natural match to many of the producers and consumers of
information. In addition, a database is easily layered atop the messaging layer
for consumers that want to query and search the information. Finally, a common
language to represent information in all layers of the information system makes
it significantly easier for users to consume information. Performance data
shows that this approach meets the significant needs of FutureGrid and would
meet the needs of an experimental infrastructure twice the size of FutureGrid.
In addition, this design also meets the needs of existing distributed
scientific infrastructures.


title: The general relativistic two body problem

abstract:
  The two-body problem in General Relativity has been the subject of many
analytical investigations. After reviewing some of the methods used to tackle
this problem (and, more generally, the N-body problem), we focus on a new,
recently introduced approach to the motion and radiation of (comparable mass)
binary systems: the Effective One Body (EOB) formalism. We review the basic
elements of this formalism, and discuss some of its recent developments.
Several recent comparisons between EOB predictions and Numerical Relativity
(NR) simulations have shown the aptitude of the EOB formalism to provide
accurate descriptions of the dynamics and radiation of various binary systems
(comprising black holes or neutron stars) in regimes that are inaccessible to
other analytical approaches (such as the last orbits and the merger of
comparable mass black holes). In synergy with NR simulations, post-Newtonian
(PN) theory and Gravitational Self-Force (GSF) computations, the EOB formalism
is likely to provide an efficient way of computing the very many accurate
template waveforms that are needed for Gravitational Wave (GW) data analysis
purposes.


title: Global Symmetries and N=2 SUSY

abstract:
  We prove that N=2 theories that arise by taking n free hypermultiplets and
gauging a subgroup of Sp(n), the non-R global symmetry of the free theory, have
a remaining global symmetry which is a direct sum of unitary, symplectic, and
special orthogonal factors. This implies that theories that have SU(N) but not
U(N) global symmetries, such as Gaiotto's T_N theories, are not likely to arise
as IR fixed points of RG flows from weakly coupled N=2 gauge theories.


title: Transmission of a continuous signal via one-bit capacity channel

abstract:
  We study the problem of the transmission of currently observed time variable
signals via a channel that is capable of sending a single binary signal only
for each measurement of the underlying process. For encoding and decoding, we
suggest a modification othe adaptive delta modulation algorithm. This
modification ensures tracking of time variable signals. We obtained upper
estimates for the error for the case of noiseless transmission.


title:
Connection between Fisher Information and Wave Mechanical
  Interpretations of Universe

abstract:
  In this study, we model the dark matter and baryon matter distribution in the
Cosmic Web by means of highly nonlinear Schr\"{o}dinger type and reaction
diffusion wave mechanical descriptions. The construction of these wave
mechanical models of the structure formation is achieved by introducing the
Fisher information measure and its comparison with a highly nonlinear term
called the quantum potential in the wave equations. Strikingly, the comparison
of the nonlinear term and the Fisher information measure provides a dynamical
distinction between lack of self-organization and self-organization in the
dynamical evolution of the cosmic components. Mathematically equivalent to the
standard cosmic fluid equations, these approaches make it possible to follow
the evolution of the matter distribution even into the highly nonlinear regime
by circumventing singularities. In addition, these wave formalisms are extended
to two-fluid descriptions of the coupled dark matter and baryon matter
distributions in the linear regime, in the Einstein de Sitter Universe (EdS) to
construct toy models of the cosmic components in this relatively simple
Universe model. Based on these two different wave mechanical formalisms, here
fully analytical results for the dark matter and baryon distributions are
provided. Also, numerical realizations of the emerging weblike patterns are
presented from the nonlinear dynamics of the baryon component corresponding to
soliton-like solutions. These soliton-like solutions might represent a proper
description of filamentary structures even in the linear regime.


title:
Early Thermal Evolution of Planetesimals and its Impact on Processing
  and Dating of Meteoritic Material

abstract:
  Radioisotopic ages for meteorites and their components provide constraints on
the evolution of small bodies: timescales of accretion, thermal and aqueous
metamorphism, differentiation, cooling and impact metamorphism. Realising that
the decay heat of short-lived nuclides (e.g. 26Al, 60Fe), was the main heat
source driving differentiation and metamorphism, thermal modeling of small
bodies is of utmost importance to set individual meteorite age data into the
general context of the thermal evolution of their parent bodies, and to derive
general conclusions about the nature of planetary building blocks in the early
solar system. As a general result, modelling easily explains that iron
meteorites are older than chondrites, as early formed planetesimals experienced
a higher concentration of short-lived nuclides and more severe heating.
However, core formation processes may also extend to 10 Ma after formation of
Calcium-Aluminum-rich inclusions (CAIs). A general effect of the porous nature
of the starting material is that relatively small bodies (< few km) will also
differentiate if they form within 2 Ma after CAIs. A particular interesting
feature to be explored is the possibility that some chondrites may derive from
the outer undifferentiated layers of asteroids that are differentiated in their
interiors. This could explain the presence of remnant magnetization in some
chondrites due to a planetary magnetic field.


title:
Enhanced term of order $G^3$ in the light travel time: discussion for
  some solar system experiments

abstract:
  It is generally believed that knowing the light travel time up to the
post-post-Minkowskian level (terms in $G^2$) is sufficient for modelling the
most accurate experiments designed to test general relativity in a foreseeable
future. However, we have recently brought a rigorous justification of the
existence of an enhanced term of order $G^3$ which becomes larger than some
first-order contributions like the gravitomagnetic effect due to the rotation
of the Sun or the solar quadrupole moment for light rays almost grazing the
solar surface. We show that this enhanced term must be taken into account in
solar system experiments aiming to reach an accuracy less than $10^{-7}$ in
measuring the post-Newtonian parameter $\gamma$.


title: Congruences concerning Lucas' law of repetition

abstract:
  Let $P,Q\in\Bbb Z$, $U_0=0,\ U_1=1$ and $U_{n+1}=PU_n-QU_{n+1}$. In this
paper we obtain a general congruence for $U_{kmn^r}/U_k\pmod {n^{r+1}}$, where
$k,m,n,r$ are positive integers. As applications we extend Lucas' law of
repetition and characterize the square prime factors of $a^n+1$ or $S_n$, where
$\{S_n\}$ is given by $S_1=P^2+2$ and $S_{k+1}=S_k^2-2\ (k\ge 1)$.


title:
On Supermembrane in D=4, multiple M0-brane in D=11 and Supersymmetric
  Higher Spin Theories

abstract:
  In this thesis we have obtained and studied the complete set of superfield
equations of motion for the interacting system of four-dimensional
supermembrane and dynamical scalar multiplet. This study provides the first
example of superfield equations for interacting system involving matter
superfields and extended supersymmetric object, as well as the first set of
superfield equations of motion for a dynamical system which includes
supermembrane. The action for a supermembrane in a N = 1 D = 4 chiral
superfield background has been also presented for the first time. We have
obtained the complete set of equations of motion in spacetime components for
the interacting system of dynamical D = 4 N = 1 supergravity and supermembrane
from the superfield equations. To this end we have developed the Wess - Zumino
approach type to Grisaru - Siegel - Gates - Ovrut - Waldram special minimal
supergravity characterized by a dynamically generated cosmological constant. We
have also found the superfield equations in N-extended tensorial superspaces
with N = 2,4 and 8, which describe the D = 4 supermultiplets of massless
conformal higher spin theory with N-extended supersymmetry. On the other hand,
we have obtained the equations of motion of the system of multiple M0-brane
derived from the covariant, supersymmetric and kappa-symmetric action proposed
for such a system . We have also studied the gauge symmetries of the action
which allows us to find the final form of the bosonic equations of motion for
the center of energy coordinate functions. We have also shown that all BPS
states of the system are (1/2)BPS states and have the same properties as the
BPS states of a single M0-brane.


title:
Strong Dynamical Heterogeneity and Universal Scaling in Driven Granular
  Fluids

abstract:
  Large scale simulations of two-dimensional bidisperse granular fluids allow
us to determine spatial correlations of slow particles via the four-point
structure factor $S_4(q,t)$. Both cases, elastic ($\varepsilon=1$) as well as
inelastic ($\varepsilon < 1$) collisions, are studied. As the fluid approaches
structural arrest, i.e. for packing fractions in the range $0.6 \le \phi \le
0.805$, scaling is shown to hold: $S_4(q,t)/\chi_4(t)=s(q\xi(t))$. Both the
dynamic susceptibility, $\chi_4(\tau_{\alpha})$, as well as the dynamic
correlation length, $\xi(\tau_{\alpha})$, evaluated at the $\alpha$ relaxation
time, $\tau_{\alpha}$, can be fitted to a power law divergence at a critical
packing fraction. The measured $\xi(\tau_{\alpha})$ widely exceeds the largest
one previously observed for hard sphere 3d fluids. The number of particles in a
slow cluster and the correlation length are related by a robust power law,
$\chi_4(\tau_{\alpha}) \approx\xi^{d-p}(\tau_{\alpha})$, with an exponent
$d-p\approx 1.6$. This scaling is remarkably independent of $\varepsilon$, even
though the strength of the dynamical heterogeneity increases dramatically as
$\varepsilon$ grows.


title: Loss-tolerant quantum cryptography with imperfect sources

abstract:
  In principle, quantum key distribution (QKD) offers unconditional security
based on the laws of physics. In practice, flaws in the state preparation
undermine the security of QKD systems, as standard theoretical approaches to
deal with state preparation flaws are not loss-tolerant. An eavesdropper can
enhance and exploit such imperfections through quantum channel loss, thus
dramatically lowering the key generation rate. Crucially, the security analyses
of most existing QKD experiments are rather unrealistic as they typically
neglect this effect. Here, we propose a novel and general approach that makes
QKD loss-tolerant to state preparation flaws. Importantly, it suggests that the
state preparation process in QKD can be significantly less precise than
initially thought. Our method can widely apply to other quantum cryptographic
protocols.


title:
Purification of molybdenum oxide, growth and characterization of medium
  size zinc molybdate crystals for the LUMINEU program

abstract:
  The LUMINEU program aims at performing a pilot experiment on neutrinoless
double beta decay of 100Mo using radiopure ZnMoO4 crystals operated as
scintillating bolometers. Growth of high quality radiopure crystals is a
complex task, since there are no commercially available molybdenum compounds
with the required levels of purity and radioactive contamination. This paper
discusses approaches to purify molybdenum and synthesize compound for high
quality radiopure ZnMoO4 crystal growth. A combination of a double sublimation
(with addition of zinc molybdate) with subsequent recrystallization in aqueous
solutions (using zinc molybdate as a collector) was used. Zinc molybdate
crystals up to 1.5 kg were grown by the low-thermal-gradient Czochralski
technique, their optical, luminescent, diamagnetic, thermal and bolometric
properties were tested.


title: Density Estimation in Infinite Dimensional Exponential Families

abstract:
  In this paper, we consider an infinite dimensional exponential family,
$\mathcal{P}$ of probability densities, which are parametrized by functions in
a reproducing kernel Hilbert space, $H$ and show it to be quite rich in the
sense that a broad class of densities on $\mathbb{R}^d$ can be approximated
arbitrarily well in Kullback-Leibler (KL) divergence by elements in
$\mathcal{P}$. The main goal of the paper is to estimate an unknown density,
$p_0$ through an element in $\mathcal{P}$. Standard techniques like maximum
likelihood estimation (MLE) or pseudo MLE (based on the method of sieves),
which are based on minimizing the KL divergence between $p_0$ and
$\mathcal{P}$, do not yield practically useful estimators because of their
inability to efficiently handle the log-partition function. Instead, we propose
an estimator, $\hat{p}_n$ based on minimizing the \emph{Fisher divergence},
$J(p_0\Vert p)$ between $p_0$ and $p\in \mathcal{P}$, which involves solving a
simple finite-dimensional linear system. When $p_0\in\mathcal{P}$, we show that
the proposed estimator is consistent, and provide a convergence rate of
$n^{-\min\left\{\frac{2}{3},\frac{2\beta+1}{2\beta+2}\right\}}$ in Fisher
divergence under the smoothness assumption that $\log
p_0\in\mathcal{R}(C^\beta)$ for some $\beta\ge 0$, where $C$ is a certain
Hilbert-Schmidt operator on $H$ and $\mathcal{R}(C^\beta)$ denotes the image of
$C^\beta$. We also investigate the misspecified case of $p_0\notin\mathcal{P}$
and show that $J(p_0\Vert\hat{p}_n)\rightarrow \inf_{p\in\mathcal{P}}J(p_0\Vert
p)$ as $n\rightarrow\infty$, and provide a rate for this convergence under a
similar smoothness condition as above. Through numerical simulations we
demonstrate that the proposed estimator outperforms the non-parametric kernel
density estimator, and that the advantage with the proposed estimator grows as
$d$ increases.


title:
The limit shape of random permutations with polynomially growing cycle
  weights

abstract:
  In this work we are considering the behavior of the limit shape of Young
diagrams associated to random permutations on the set $\{1,\dots,n\}$ under a
particular class of multiplicative measures. Our method is based on generating
functions and complex analysis (saddle point method). We show that fluctuations
near a point behave like a normal random variable and that the joint
fluctuations at different points of the limiting shape have an unexpected
dependence structure. We will also compare our approach with the so-called
randomization of the cycle counts of permutations and we will study the
convergence of the limit shape to a continuous stochastic process.


title: The Kirby torus trick for surfaces

abstract:
  This is an expository paper giving a proof of the existence and uniqueness of
smooth structures (hence also PL structures) on topological surfaces. Most
published proofs rely on the topological Schoenflies theorem, but here we use
instead the Kirby torus trick. This has the advantage of reducing the point-set
topology in the proof to practically nothing, replacing it by a few basic facts
about smooth surfaces. Uniqueness of smooth structures is proved in the strong
form that every homeomorphism between smooth surfaces is isotopic to a
diffeomorphism.


title:
Large N lattice QCD and its extended strong-weak connection to the
  hypersphere

abstract:
  We calculate an effective Polyakov line action of QCD at large Nc and large
Nf from a combined lattice strong coupling and hopping expansion working to
second order in both, where the order is defined by the number of windings in
the Polyakov line. We compare with the action, truncated at the same order, of
continuum QCD on S^1 x S^d at weak coupling from one loop perturbation theory,
and find that a large Nc correspondence of equations of motion found in
\cite{Hollowood:2012nr} at leading order, can be extended to the next order.
Throughout the paper, we review the background necessary for computing higher
order corrections to the lattice effective action, in order to make higher
order comparisons more straightforward.


title: Coleman-Weinberg mechanism in spinor Bose-Einstein condensates

abstract:
  It is argued that a continuous quantum phase transition between different
ordered phases in spinor Bose-Einstein condensates predicted by the mean-field
theory is vulnerable to quantum fluctuations. By analyzing Lee-Huang-Yang
corrections in the condensate, we demonstrate that the so-called
Coleman-Weinberg mechanism takes place in such a transition, that is, the
transition becomes of the first order by quantum fluctuations. A jump to be
expected in this first-order transition is induced by a correction from density
fluctuations despite a transition between different magnetic properties with
keeping condensation. We exemplify this with an experimentally relevant case
and show that a measurement of a condensate depletion can be utilized to
confirm the first-order transition.


title: gamma Peg: testing Vega-like magnetic fields in B stars

abstract:
  gam Peg is a bright B pulsator showing both p and g modes of beta Cep and SPB
types. It has also been claimed to be a magnetic star by some authors while
others do not detect a magnetic field. We aimed at checking for the presence of
a field, characterise it if it exists or provide a firm upper limit of its
strength if it is not detected. If gam Peg is magnetic, it would make an ideal
asteroseismic target to test various theoretical scenarios. If it is very
weakly magnetic, it would be the first observation of an extension of Vega-like
fields to early B stars. Finally, if it is not magnetic and we can provide a
very low upper limit on its non-detected field, it would make an important
result for stellar evolution models. We acquired high resolution, high
signal-to-noise spectropolarimetric Narval data at TBL. We also gathered
existing dimaPol@DAO and Musicos@TBL spectropolarimetric data. We analysed the
Narval and Musicos observations using the LSD technique to derive the
longitudinal magnetic field and Zeeman signatures in lines. The longitudinal
field strength was also extracted from the Hbeta line observed with the DAO.
With a Monte Carlo simulation we derived the maximum strength of the field
possibly hosted by gam Peg. We find that no magnetic signatures are visible in
the very high quality spectropolarimetric data. The average longitudinal field
measured in the Narval data is Bl=-0.1+/-0.4 G. We derive a very strict upper
limit of the dipolar field strength of Bpol~40 G. We conclude that gamma Peg is
not magnetic: it does not host a strong stable fossil field as observed in a
fraction of massive stars, nor a very weak Vega-like field. There is therefore
no evidence that Vega-like fields exist in B stars contrary to the predictions
by fossil field dichotomy scenarios. These scenarios should thus be revised.
Our results also provide strong constraints for stellar evolution models.


title: Sparse Matrix-based Random Projection for Classification

abstract:
  As a typical dimensionality reduction technique, random projection can be
simply implemented with linear projection, while maintaining the pairwise
distances of high-dimensional data with high probability. Considering this
technique is mainly exploited for the task of classification, this paper is
developed to study the construction of random matrix from the viewpoint of
feature selection, rather than of traditional distance preservation. This
yields a somewhat surprising theoretical result, that is, the sparse random
matrix with exactly one nonzero element per column, can present better feature
selection performance than other more dense matrices, if the projection
dimension is sufficiently large (namely, not much smaller than the number of
feature elements); otherwise, it will perform comparably to others. For random
projection, this theoretical result implies considerable improvement on both
complexity and performance, which is widely confirmed with the classification
experiments on both synthetic data and real data.


title: Tricritical behavior of soft nematic elastomers

abstract:
  We propose a lattice statistical model to investigate the phase diagrams and
the soft responses of nematic liquid-crystal elastomers. Using suitably scaled
infinite-range interactions, we obtain exact self-consistent equations for the
tensor components of the nematic order parameter in terms of temperature, the
distortion and stress tensors, and the initial nematic order. These equations
are amenable to simple numerical calculations, which are used to characterize
the low-temperature soft regime. We find a peculiar phase diagram, in terms of
temperature and the diagonal component of the distortion tensor along the
stretching direction, with first- and second-order transitions to the soft
phase, and the prediction of tricritical points. This behavior is not
qualitatively changed if we use different values of the initial nematic order
parameter.


title:
Measurement of dijet cross sections in pp collisions at 7 TeV
  centre-of-mass energy using the ATLAS detector

abstract:
  Double-differential dijet cross sections measured in pp collisions at the LHC
with a 7 TeV centre-of-mass energy are presented as functions of dijet mass and
rapidity separation of the two highest-pT jets. These measurements are obtained
using data corresponding to an integrated luminosity of 4.5/fb, recorded by the
ATLAS detector in 2011. The data are corrected for detector effects so that
cross sections are presented at the particle level. Cross sections are measured
up to 5 TeV dijet mass using jets reconstructed with the anti-kt algorithm for
values of the jet radius parameter of 0.4 and 0.6. The cross sections are
compared with next-to-leading-order perturbative QCD calculations by NLOJET++
corrected to account for non-perturbative effects. Comparisons with POWHEG
predictions, using a next-to-leading-order matrix element calculation
interfaced to a parton-shower Monte Carlo simulation, are also shown.
Electroweak effects are accounted for in both cases. The quantitative
comparison of data and theoretical predictions obtained using various
parameterizations of the parton distribution functions is performed using a
frequentist method. An example setting a lower limit on the compositeness scale
for a model of contact interactions is presented, showing that the unfolded
results can be used to constrain contributions to dijet production beyond that
predicted by the Standard Model.


title: Oracle Inequalities for Convex Loss Functions with Non-Linear Targets

abstract:
  This paper consider penalized empirical loss minimization of convex loss
functions with unknown non-linear target functions. Using the elastic net
penalty we establish a finite sample oracle inequality which bounds the loss of
our estimator from above with high probability. If the unknown target is linear
this inequality also provides an upper bound of the estimation error of the
estimated parameter vector. These are new results and they generalize the
econometrics and statistics literature. Next, we use the non-asymptotic results
to show that the excess loss of our estimator is asymptotically of the same
order as that of the oracle. If the target is linear we give sufficient
conditions for consistency of the estimated parameter vector. Next, we briefly
discuss how a thresholded version of our estimator can be used to perform
consistent variable selection. We give two examples of loss functions covered
by our framework and show how penalized nonparametric series estimation is
contained as a special case and provide a finite sample upper bound on the mean
square error of the elastic net series estimator.


title:
Non-fillable invariant contact structures on principal circle bundles
  and left-handed twists

abstract:
  We define symplectic fractional twists, which generalize Dehn twists, and use
these in open books to investigate contact structures. The resulting contact
structures are invariant under a circle action, and share several similarities
with the invariant contact structures that were studied by Lutz and Giroux. We
show that left-handed fractional twists often give rise to non-fillable contact
manifolds. These manifolds are in fact "algebraically overtwisted", yet they do
not seem to contain bLobs, nor are they directly related to negative
stabilizations. We also show that the Weinstein conjecture holds for the
non-fillable contact manifolds we construct, and we investigate the symplectic
isotopy problem for fractional twists.


title:
A Flat Triangular Form for Nonlinear Systems with Two Inputs: Necessary
  and Sufficient Conditions

abstract:
  The present work establishes necessary and sufficient conditions for a
nonlinear system with two inputs to be described by a specific triangular form.
Except for some regularity conditions, such triangular form is flat. This may
lead to the discovery of new flat systems. The proof relies on well-known
results for driftless systems with two controls (the chained form) and on
geometric tools from exterior differential systems. The paper also illustrates
the application of its results on an academic example and on a reduced order
model of an induction motor.


title:
Algebraic dynamical systems and Dirichlet's unit theorem on arithmetic
  varieties

abstract:
  In this paper, we study obstructions to the Dirichlet property by two
approaches: density of non-positive points and functionals on adelic
R-divisors. Applied to the algebraic dynamical systems, these results provide
examples of nef adelic arithmetic R-Cartier divisor which does not have the
Dirichlet property. We hope the obstructions obtained in the article will give
ways toward criteria of the Dirichlet property.


title: The Best Inflationary Models After Planck

abstract:
  We compute the Bayesian evidence and complexity of 193 slow-roll single-field
models of inflation using the Planck 2013 Cosmic Microwave Background data,
with the aim of establishing which models are favoured from a Bayesian
perspective. Our calculations employ a new numerical pipeline interfacing an
inflationary effective likelihood with the slow-roll library ASPIC and the
nested sampling algorithm MULTINEST. The models considered represent a complete
and systematic scan of the entire landscape of inflationary scenarios proposed
so far. Our analysis singles out the most probable models (from an Occam's
razor point of view) that are compatible with Planck data, while ruling out
with very strong evidence 34% of the models considered. We identify 26% of the
models that are favoured by the Bayesian evidence, corresponding to 15
different potential shapes. If the Bayesian complexity is included in the
analysis, only 9% of the models are preferred, corresponding to only 9
different potential shapes. These shapes are all of the plateau type.


title:
Non-collapsing for nearly spherical closed curves under power curvature
  flow

abstract:
  We show non-collapsing for the evolution of nearly spherical closed convex
curves in \mathbb{R}^2 under power curvature flow using two-point-methods.


title: On equal values of power sums of arithmetic progressions

abstract:
  In this paper we consider the Diophantine equation \begin{align*}b^k
+\left(a+b\right)^k &+ \cdots + \left(a\left(x-1\right) + b\right)^k=\\ &=d^l +
\left(c+d\right)^l + \cdots + \left(c\left(y-1\right) + d\right)^l,
\end{align*} where $a,b,c,d,k,l$ are given integers. We prove that, under some
reasonable assumptions, this equation has only finitely many integer solutions.


title:
The utilization of social networking as promotion media (Case study:
  Handicraft business in Palembang)

abstract:
  Nowadays social media (Twitter, Facebook, etc.), not only simply as
communication media, but also for promotion. Social networking media offers
many business benefits for companies and organizations. Research purposes is to
determine the model of social network media utilization as a promotional media
for handicraft business in Palembang city. Qualitative and quantitative
research design are used to know how handicraft business in Palembang city
utilizing social media networking as a promotional media. The research results
show 35% craft businesses already utilizing social media as a promotional
media. The social media used are blog development 15%, facebook 46%, and
twitter etc. are 39%. The reasons they use social media such as, 1) minimal
cost, 2) easily recognizable, 3) global distribution areas. Social media
emphasis on direct engagement with customers better. So that the marketing
method could be more personal through direct communication with customers.


title: Phase transitions for a planar quadratic contact process

abstract:
  We study a two dimensional version of Neuhauser's long range sexual
reproduction model and prove results that give bounds on the critical values
$\lambda_f$ for the process to survive from a finite set and $\lambda_e$ for
the existence of a nontrivial stationary distribution. Our first result comes
from a standard block construction, while the second involves a comparison with
the "generic population model" of Bramson and Gray (1991). An interesting new
feature of our work is the suggestion that, as in the one dimensional contact
process, edge speeds characterize critical values. We are able to prove the
following for our quadratic contact process when the range is large but suspect
they are true for two dimensional finite range attractive particle systems that
are symmetric with respect to reflection in each axis. There is a speed
$c(\theta)$ for the expansion of the process in each direction. If $c(\theta) >
0$ in all directions, then $\lambda > \lambda_f$, while if at least one speed
is positive, then $\lambda > \lambda_e$. It is a challenging open problem to
show that if some speed is negative, then the system dies out from any finite
set.


title:
Computation of the chiral condensate using $N_f=2$ and $N_f=2+1+1$
  dynamical flavors of twisted mass fermions

abstract:
  We apply the spectral projector method, recently introduced by Giusti and
L\"uscher, to compute the chiral condensate using $N_f=2$ and $N_f=2+1+1$
dynamical flavors of maximally twisted mass fermions. We present our results
for several quark masses at three different lattice spacings which allows us to
perform the chiral and continuum extrapolations. In addition we report our
analysis on the $O(a)$ improvement of the chiral condensate for twisted mass
fermions. We also study the effect of the dynamical strange and charm quarks by
comparing our results for $N_f=2$ and $N_f=2+1+1$ dynamical flavors.


title:
Topological susceptibility from twisted mass fermions using spectral
  projectors

abstract:
  We discuss the computation of the topological susceptibility using the method
of spectral projectors and dynamical twisted mass fermions. We present our
analysis concerning the O(a)-improvement of the topological susceptibility and
we show numerical results for Nf=2 and Nf=2+1+1 flavours, performing a study of
the quark mass dependence in terms of leading order chiral perturbation theory.


title: D-meson diffusion in hadronic matter

abstract:
  We present effective-field-theory results with unitarized interactions on the
D-meson transport coefficients in a gas populated by light mesons and baryons
at finite temperature and baryochemical potential. The Fokker-Planck equation
is used to compute the drag force, the relaxation time and the diffusion
coefficients of D mesons for collisions at FAIR. At finite baryochemical
potential, the combined effect of net baryonic density and sizable meson-baryon
interaction makes the D mesons to relax more efficiently than in the case at
zero baryochemical potential. We also describe the connection with the
quark-gluon plasma phase in adiabatic trajectories on the phase diagram at both
zero and finite baryochemical potential.


title:
Computing the Tutte Polynomial of Lattice Path Matroids Using
  Determinantal Circuits

abstract:
  We give a quantum-inspired $O(n^4)$ algorithm computing the Tutte polynomial
of a lattice path matroid, where $n$ is the size of the ground set of the
matroid. Furthermore, this can be improved to $O(n^2)$ arithmetic operations if
we evaluate the Tutte polynomial on a given input, fixing the values of the
variables. The best existing algorithm, found in 2004, was $O(n^5)$, and the
problem has only been known to be polynomial time since 2003. Conceptually, our
algorithm embeds the computation in a determinant using a recently demonstrated
equivalence of categories useful for counting problems such as those that
appear in simulating quantum systems.


title: Smooth Orthogonal Drawings of Planar Graphs

abstract:
  In \emph{smooth orthogonal layouts} of planar graphs, every edge is an
alternating sequence of axis-aligned segments and circular arcs with common
axis-aligned tangents. In this paper, we study the problem of finding smooth
orthogonal layouts of low \emph{edge complexity}, that is, with few segments
per edge. We say that a graph has \emph{smooth complexity} k---for short, an
SC_k-layout---if it admits a smooth orthogonal drawing of edge complexity at
most $k$.
  Our main result is that every 4-planar graph has an SC_2-layout. While our
drawings may have super-polynomial area, we show that, for 3-planar graphs,
cubic area suffices. Further, we show that every biconnected 4-outerplane graph
admits an SC_1-layout. On the negative side, we demonstrate an infinite family
of biconnected 4-planar graphs that requires exponential area for an
SC_1-layout. Finally, we present an infinite family of biconnected 4-planar
graphs that does not admit an SC_1-layout.


title: Hairy Wormholes and Bartnik-McKinnon Solutions

abstract:
  We consider Lorentzian wormholes supported by a phantom field and threaded by
non-trivial Yang-Mills fields, which may be regarded as hair on the Ellis
wormhole. Like the Bartnik-McKinnon solutions and their associated hairy black
holes, these hairy wormholes form infinite sequences, labeled by the node
number $k$ of their gauge field function. We discuss the throat geometry of
these wormholes, showing that odd-$k$ solutions may exhibit a double-throat,
and evaluate their global charges. We analyze the limiting behavior exhibited
by wormhole solutions as the gravitational coupling becomes large. The even-$k$
solutions approach smoothly the Bartnik-McKinnon solutions with $k/2$ nodes,
while the odd-$k$ solutions develop a singular behavior at the throat in the
limit of large coupling. In the limit of large $k$, on the other hand, an
embedded Abelian wormhole solution is approached, when the throat is large. For
smaller throats the extremal Reissner-Nordstr\"om solution plays a fundamental
role in the limit.


title: Integrable cosmological models with non-minimally coupled scalar fields

abstract:
  We obtain general solutions for some flat Friedmann universes filled with a
scalar field in induced gravity models and models including the
Hilbert-Einstein curvature term plus a scalar field conformally coupled to
gravity. As is well known, these models are connected to minimally coupled
models through the combination of a conformal transformation and a
transformation of the scalar field. The explicit forms of the self-interaction
potentials for six exactly solvable models are presented here. We obtain the
general solution for one of the integrable models, namely, the induced gravity
model with a power-law potential for the self-interaction of the scalar field.
We argue that although being mathematically in a one-to-one correspondence with
the solutions in the minimally coupled models, the solutions in the
corresponding non-minimally coupled models are physically different. This is
because the cosmological evolutions seen by an internal observer connected with
the cosmic time can be quite different. The study of a few induced gravity
models with particular potentials gives us an explicit example of such a
difference.


title:
Influence of the structure defects on the magnetic properties of the
  FePt/Fe bilayer

abstract:
  Thin magnetic multilayered films containing FePt have attracted a lot of
attention recently due to their possible usage in ultra-high density magnetic
storage. Although structure defects play a dramatic role in the magnetization
process and influence magnetic properties in general this dependence haven't
been studied thoroughly. The main aim of this work was to perform theoretical
investigation of the magnetic properties of FePt and Fe/FePt thin films with
high coercivity with respect to the structure defects such as anisotropy
constant, magnetization saturation, exchange constant fluctuations and easy
axis deviation. For selected defect patterns the coercive field dependence on
layer thicknesses was analysed. Numerical study of the bilayer with hard
magnetic layer having the planar anisotropy was carried on using micromagnetic
calculations. Values of layers thickness have been found optimal for
perspective applications, the dependence of the hysteresis loop shape upon the
magnetization process has been shown and analysed.


title: S-matrix for strings on $\eta$-deformed AdS5 x S5

abstract:
  We determine the bosonic part of the superstring sigma model Lagrangian on
$\eta$-deformed AdS5 x S5, and use it to compute the perturbative world-sheet
scattering matrix of bosonic particles of the model. We then compare it with
the large string tension limit of the q-deformed S-matrix and find exact
agreement.


title: Optimal Distributed Control for Networked Control Systems with Delays

abstract:
  In networked control systems (NCS), sensing and control signals between the
plant and controllers are typically transmitted wirelessly. Thus, the time
delay plays an important role for the stability of NCS, especially with
distributed controllers. In this paper, the optimal control strategy is derived
for distributed control networks with time delays. In particular, we form the
optimal control problem as a non-cooperative linear quadratic game (LQG). Then,
the optimal control strategy of each controller is obtained that is based on
the current state and the last control strategies. The proposed optimal
distributed controller reduces to some known controllers under certain
conditions. Moreover, we illustrate the application of the proposed distributed
controller to load frequency control in power grid systems.


title: The Metallicity of High-$z$ GRBs: the Case of GRB 111008A

abstract:
  With optical and near-infrared follow-up observations of gamma-ray bursts
(GRBs) it is possible to study the chemical enrichment of galaxies at high
redshift. Especially interesting are measurements of the metallicity of GRB
host with $z\gtrsim 4.7$, since it has recently been shown that damped
Lymann-$\alpha$ absorbers have a rapid decrease in metallicity at this redshift
(Rafelski et al. 2013). In this paper measurements of the amount of metals and
dust in the host galaxy of GRB 111008A at $z=5.0$ is presented, and it is
discussed how observations of more high-$z$ GRB host galaxies can give clues
about dust formation mechanisms and the distribution of metals in the early
Universe.


title: Quantum state majorization at the output of bosonic Gaussian channels

abstract:
  Quantum communication theory explores the implications of quantum mechanics
to the tasks of information transmission. Many physical channels can be
formally described as quantum Gaussian operations acting on bosonic quantum
states. Depending on the input state and on the quality of the channel, the
output suffers certain amount of noise. For a long time it has been
conjectured, but never proved, that output states of Gaussian channels
corresponding to coherent input signals are the less noisy ones (in the sense
of a majorization criterion). In this work we prove this conjecture.
Specifically we show that every output state of a phase insensitive Gaussian
channel is majorized by the output state corresponding to a coherent input. The
proof is based on the optimality of coherent states for the minimization of
strictly concave output functionals. Moreover we show that coherent states are
the unique optimizers.


title: Mixed Sub-Fractional Brownian Motion

abstract:
  A new extension of the sub-fractional Brownian motion, and thus of the
Brownian motion, is introduced. It is a linear combination of a finite number
of sub-fractional Brownian motions, that we have chosen to call the mixed
sub-fractional Brownian motion. In this paper, we study some basic properties
of this process, its non-Markovian and non-stationarity characteristics, the
conditions under which it is a semimartingale, and the main features of its
sample paths. We also show that this process could serve to get a good model of
certain phenomena, taking not only the sign (like in the case of the
sub-fractional Brownian motion), but also the strength of dependence between
the increments of this phenomena into account.


title:
Nonmonotonous pressure as a function of the density in a fluid without
  attractive forces

abstract:
  A simple result for the pressure of a hard sphere fluid that was developed
many years ago by Rennert is extended in a straightforward manner by adding the
terms that are of the same form as the Rennert's formula. The resulting
expression is moderately accurate but its accuracy does not necessarily improve
as additional terms are included. This expression has the interesting
consequence that the pressure can have a maximum, as the density increases,
which is consistent with the freezing of hard spheres. This occurs solely as a
consequence of repulsive interactions. Only the Born-Green-Yvon and Kirkwood
theories show such a behavior for hard spheres and they require a numerical
solution of an integral equation. The procedure outlined here is ad hoc but is,
perhaps, useful just as the popular Carnahan-Starling equation for the hard
sphere pressure is also ad hoc but useful.


title: Bimetric Models of Gravity and Cosmology in the Early Universe

abstract:
  In this dissertation, we explore models based on the idea that there are two
metrics in spacetime: One describes the standard gravity, and the other
provides a geometry in which matter fields propagate. In order to do that, we
provide the essentials of Finsler geometry and the rules to induce a metric for
the propagation of matter. Such a description will cover some of the most
critical features related to the field necessary to do the induction, these
will arise in an attempt to build an action for this field. And finally, we
provide an example to study the homogeneous limit of background FLRW equations
for the cosmological model and the role of Lorentz symmetry breaking to provide
a graceful exit.


title:
Stars and Reionization: The Cross-Correlation of the 21cm Line and the
  Near Infrared Background

abstract:
  With improving telescopes, it may now be possible to observe the Epoch of
Reionization in multiple ways. We examine two of these observables - the excess
light in the near-infrared background that may be due to high redshift stars
and ionized HII bubbles, and the 21 cm emission from neutral hydrogen. Because
these two forms of emission should result from different, mutually exclusive
regions, an anticorrelation should exist between them. We discuss the strengths
of using cross-correlations between these observations to learn more about high
redshift star formation and reionization history. In particular, we create
simulated maps of emission from both the near-infrared background and 21 cm
emission. We find that these observations are anticorrelated, with the
strongest anticorrelation originating from times when the universe is half
ionized. This result is robust and does not depend on the properties of the
stars themselves. Rather, it depends on the ionization history.
Cross-correlations can provide redshift information, which the near-infrared
background cannot provide alone. In addition, cross-correlations can help
separate foreground emission from the true high redshift component, making it
possible to say with greater certainty that we are indeed witnessing the Epoch
of Reionization.


title: Universal neural field computation

abstract:
  Turing machines and G\"odel numbers are important pillars of the theory of
computation. Thus, any computational architecture needs to show how it could
relate to Turing machines and how stable implementations of Turing computation
are possible. In this chapter, we implement universal Turing computation in a
neural field environment. To this end, we employ the canonical symbologram
representation of a Turing machine obtained from a G\"odel encoding of its
symbolic repertoire and generalized shifts. The resulting nonlinear dynamical
automaton (NDA) is a piecewise affine-linear map acting on the unit square that
is partitioned into rectangular domains. Instead of looking at point dynamics
in phase space, we then consider functional dynamics of probability
distributions functions (p.d.f.s) over phase space. This is generally described
by a Frobenius-Perron integral transformation that can be regarded as a neural
field equation over the unit square as feature space of a dynamic field theory
(DFT). Solving the Frobenius-Perron equation yields that uniform p.d.f.s with
rectangular support are mapped onto uniform p.d.f.s with rectangular support,
again. We call the resulting representation \emph{dynamic field automaton}.


title: Production of optically trapped $^{87}$RbCs Feshbach molecules

abstract:
  We report the production of $^{87}$RbCs Feshbach molecules in a crossed-beam
dipole trap. A mixture of $^{87}$Rb and $^{133}$Cs is cooled close to quantum
degeneracy before an interspecies Feshbach resonance at 197\,G is used to
associate up to $\sim5000$ molecules with a temperature of $\sim300$\,nK. The
molecules are confined in the dipole trap with a lifetime of 0.21(1)\,s, long
enough for future experiments exploring optical transfer to the absolute ground
state. We have measured the magnetic moment of the Feshbach molecules in a
magnetic bias field range between 181 and 185\,G to demonstrate the ability to
control the character of the molecular state. In addition we have performed
Feshbach spectroscopy in a field range from 0 to 1200\,G and located three
previously unobserved resonances at high magnetic fields.


title: Counting Popular Matchings in House Allocation Problems

abstract:
  We study the problem of counting the number of popular matchings in a given
instance. A popular matching instance consists of agents A and houses H, where
each agent ranks a subset of houses according to their preferences. A matching
is an assignment of agents to houses. A matching M is more popular than
matching M' if the number of agents that prefer M to M' is more than the number
of people that prefer M' to M. A matching M is called popular if there exists
no matching more popular than M. McDermid and Irving gave a poly-time algorithm
for counting the number of popular matchings when the preference lists are
strictly ordered.
  We first consider the case of ties in preference lists. Nasre proved that the
problem of counting the number of popular matching is #P-hard when there are
ties. We give an FPRAS for this problem.
  We then consider the popular matching problem where preference lists are
strictly ordered but each house has a capacity associated with it. We give a
switching graph characterization of popular matchings in this case. Such
characterizations were studied earlier for the case of strictly ordered
preference lists (McDermid and Irving) and for preference lists with ties
(Nasre). We use our characterization to prove that counting popular matchings
in capacitated case is #P-hard.


title:
New Identities from a Combinatorial Approach to Generalized Fibonacci
  and Generalized Lucas Numbers

abstract:
  We present here some new identities for generalizations of Fibonacci and
Lucas numbers by combinatorially interpreting these numbers in terms of numbers
of certain tilings of a $1 \times m$ board. As a consequence, some new
interesting identities involving the ordinaries Fibonacci and Lucas numbers are
derived.


title:
Magnetic structure of superconducting Eu(Fe0.82Co0.18)2As2 as revealed
  by single-crystal neutron diffraction

abstract:
  The magnetic structure of superconducting Eu(Fe0.82Co0.18)2As2 is
unambiguously determined by single-crystal neutron diffraction. A long-range
ferromagnetic order of the Eu2+ moments along the c-direction is revealed below
the magnetic phase transition temperature Tc = 17 K. In addition, the
antiferromagnetism of the Fe2+ moments still survives and the
tetragonal-to-orthorhombic structural phase transition is also observed,
although the transition temperatures of the Fe-spin density wave (SDW) order
and the structural phase transition are significantly suppressed to Tn = 70 K
and Ts = 90 K, respectively, compared to the parent compound EuFe2As2.We
present the microscopic evidences for the coexistence of the Eu-ferromagnetism
(FM) and the Fe-SDW in the superconducting crystal. The superconductivity (SC)
competes with the Fe-SDW in Eu(Fe0.82Co0.18)2As2.Moreover, the comparison
between Eu(Fe1-xCox)2As2 and Ba(Fe1-xCox)2As2 indicates a considerable
influence of the rare-earth element Eu on the magnetism of the Fe sublattice.


title:
Prospects of Turbulence Studies in High-Energy Density Laser-Generated
  Plasma: Numerical Investigations in Two Dimensions

abstract:
  We investigate the possibility of generating and studying turbulence in
plasma by means of high-energy density laser-driven experiments. Our focus is
to create supersonic, self-magnetized turbulence with characteristics that
resemble those found in the interstellar medium (ISM).
  We consider a target made of a spherical core surrounded by a shell made of
denser material. The shell is irradiated by a sequence of laser pulses sending
inward-propagating shocks that convert the inner core into plasma and create
turbulence. In the context of the evolution of the ISM, the shocks play the
role of supernova remnant shocks and the core represents the ionized
interstellar medium. We consider the effects of both pre-existing and
self-generating magnetic fields and study the evolution of the system by means
of two-dimensional numerical simulations.
  We find that the evolution of the turbulent core is generally, subsonic with
rms-Mach number $M_t\approx 0.2$. We observe an isotropic, turbulent velocity
field with an inertial range power spectra of $P(k)\propto k^{-2.3}$. We
account for the effects of self-magnetization and find that the resulting
magnetic field has characteristic strength $\approx 3\times 10^{4}$ G. The
corresponding plasma beta is $\approx 1\times 10^{4}$--$1\times 10^{5}$,
indicating that the magnetic field does not play an important role in the
dynamical evolution of the system.
  The natural extension of this work is to study the system evolution in
three-dimensions, with various laser drive configurations, and targets with
shells and cores of different masses. The latter modification may help to
increase the turbulent intensity and possibly create transonic turbulence. One
of the key challenges is to obtain transonic turbulent conditions in a
quasi-steady state environment.


title: Line driven winds and the UV turnover in AGN accretion discs

abstract:
  AGN SEDs generally show a turnover at lambda 1000A, implying a maximal
accretion disc (AD) temperature of T_max~50,000K. Massive O stars display a
similar T_max, associated with a sharp rise in a line driven mass loss
Mdot_wind with increasing surface temperature. AGN AD are also characterized by
similar surface gravity to massive O stars. The Mdot_wind of O stars reaches
~10^-5 Msun/year. Since the surface area of AGN AD can be 10^6 larger, the
implied Mdot_wind in AGN AD can reach the accretion rate Mdot. A rise to
Mdot_wind Mdot towards the AD center may therefore set a similar cap of
T_max~50,000K. To explore this idea, we solve the radial structure of an AD
with a mass loss term, and calculate the implied AD emission using the mass
loss term derived from observations of O stars. We find that Mdot_wind becomes
comparable to Mdot typically at a few 10s of GM/c^2. Thus, the standard thin AD
solution is effectively truncated well outside the innermost stable orbit. The
calculated AD SED shows the observed turnover at lambda~1000A, which is weakly
dependent on the AGN luminosity and black hole mass. The AD SED is generally
independent of the black hole spin, due to the large truncation radius.
However, a cold AD (low Mdot, high black hole mass) is predicted to be
windless, and thus its SED should be sensitive to the black hole spin. The
accreted gas may form a hot thick disc with a low radiative efficiency inside
the truncation radius, or a strong line driven outflow, depending on its
ionization state.


title: An extension of H\"{o}rmander's hypoellipticity theorem

abstract:
  Motivated by applications to stochastic differential equations, an extension
of H\"{o}rmander's hypoellipticity theorem is proved for second-order
degenerate elliptic operators with non-smooth coefficients. The main results
are established using point-wise Bessel kernel estimates and a weighted Sobolev
inequality of Stein and Weiss. Of particular interest is that our results apply
to operators with quite general first-order terms.


title:
CMB constraints on mass and coupling constant of light pseudoscalar
  particles

abstract:
  Transformation of CMB photons into light pseudoscalar particles at post big
bang nucleosynthesis epoch is considered. Using the present day value of a
large scale magnetic field to estimate it at earlier cosmological epochs, the
oscillation probability of photons into light pseudoscalar particles with an
account of coherence breaking in cosmological plasma is calculated. Demanding
that the photon transformation does not lead to an exceedingly large CMB
spectral distortion and temperature anisotropy, the constraints on the coupling
constant of axion like particles to photons, $ g_{\phi\gamma} B \lesssim
(10^{-15} - 10^{-12}) \textrm{nG}\times \textrm{GeV}^{-1}$, are found for the
axion like particle mass in the interval $10^{-25}$ eV $\lesssim
m_{\phi}\lesssim 10^{-5}$ eV, where $B$ is the strength of the large scale
magnetic field at the present time. Our results update the previously obtained
ones since we use the density matrix formalism which is more accurate than the
wave function approximation for the description of oscillations with an
essential coherence breaking. In the axion like particle mass range $10^{-25}$
eV $\lesssim m_{\phi}\lesssim 10^{-14}$ eV, weaker limits, by at least 2 orders
of magnitude $g_{\phi\gamma} B \lesssim 10^{-11}\textrm{nG}\times
\textrm{GeV}^{-1}$, are obtained in comparison with the wave function
approximation. In the mass range $10^{-14}$ eV $\lesssim m_{\phi}\lesssim
10^{-5}$ eV, on the other hand, limits that are stronger, by more than an order
of magnitude are obtained. Our results are derived by using upper limits on
spectral distortion parameter $\mu$ and temperature anisotropy $\Delta T/T$
found by COBE and expected sensitivities by PIXIE/PRISM.


title: Biomimetic Cloning of Quantum Observables

abstract:
  We propose a bio-inspired sequential quantum protocol for the cloning and
preservation of the statistics associated to quantum observables of a given
system. It combines the cloning of a set of commuting observables, permitted by
the no-cloning and no-broadcasting theorems, with a controllable propagation of
the initial state coherences to the subsequent generations. The protocol mimics
the scenario in which an individual in an unknown quantum state copies and
propagates its quantum information into an environment of blank qubits.
Finally, we propose a realistic experimental implementation of this protocol in
trapped ions.


title: An Exploration of Advanced X-Divertors on ITER

abstract:
  It is found that the X-Divertor (XD) configuration [1-3] can be made with the
conventional PF coil set on ITER[4], where all PF coils are outside the TF
coils. Desirable configurations are possible where the PF currents are below
the present maximum design limits on ITER, and where the baseline divertor
cassette is used. It is possible that the XD could be used to assist in
high-power operation on ITER, but some further issues need examination. Note
that the increased major radius of the Super X-Divertor (SXD) [5-8] is not a
feature of the XD geometry. In addition, we present an XD configuration for
K-DEMO [9], to demonstrate that it is also possible to attain the XD
configuration in advanced tokamak reactors with all PF coils outside the TF
coils. The results given here for the XD are far more encouraging than recent
calculations by Lackner and Zohm [10] for the Snowflake [11,12], where the
required high PF currents represent a major technological challenge. The
magnetic field structure in the outboard divertor SOL [13] in the recently
created XD configurations reproduces what was presented in the earlier XD
papers [1-3]. Consequently, the same advantages accrue, but no close-in PF
coils are employed.