title:
Limited Feedback Design for Interference Alignment on MIMO Interference
  Networks with Heterogeneous Path Loss and Spatial Correlations

abstract:
  Interference alignment is degree of freedom optimal in K -user MIMO
interference channels and many previous works have studied the transceiver
designs. However, these works predominantly focus on networks with perfect
channel state information at the transmitters and symmetrical interference
topology. In this paper, we consider a limited feedback system with
heterogeneous path loss and spatial correlations, and investigate how the
dynamics of the interference topology can be exploited to improve the feedback
efficiency. We propose a novel spatial codebook design, and perform dynamic
quantization via bit allocations to adapt to the asymmetry of the interference
topology. We bound the system throughput under the proposed dynamic scheme in
terms of the transmit SNR, feedback bits and the interference topology
parameters. It is shown that when the number of feedback bits scales with SNR
as C_{s}\cdot\log\textrm{SNR}, the sum degrees of freedom of the network are
preserved. Moreover, the value of scaling coefficient C_{s} can be
significantly reduced in networks with asymmetric interference topology.


title: Vaccination intervention on epidemic dynamics in networks

abstract:
  Vaccination is an important measure available for preventing or reducing the
spread of infectious diseases. In this paper, an epidemic model including
susceptible, infected, and imperfectly vaccinated compartments is studied on
Watts-Strogatz small-world, Barab\'asi-Albert scale-free, and random scale-free
networks. The epidemic threshold and prevalence are analyzed. For small-world
networks, the effective vaccination intervention is suggested and its influence
on the threshold and prevalence is analyzed. For scale-free networks, the
threshold is found to be strongly dependent both on the effective vaccination
rate and on the connectivity distribution. Moreover, so long as vaccination is
effective, it can linearly decrease the epidemic prevalence in small-world
networks, whereas for scale-free networks it acts exponentially. These results
can help in adopting pragmatic treatment upon diseases in structured
populations.


title: The searchlight effect in hyperbolic materials

abstract:
  The quasistatic field around a circular hole in a two-dimensional hyperbolic
medium is studied. As the loss parameter goes to zero, it is found that the
electric field diverges along four lines each tangent to the hole. In this
limit, the power dissipated by the field in the vicinity of these lines, per
unit length of the line, goes to zero but extends further and further out so
that the net power dissipated remains finite. Additionally the interaction
between polarizable dipoles in a hyperbolic medium is studied. It is shown that
a dipole with small polarizability can dramatically influence the dipole moment
of a distant polarizable dipole, if it is appropriately placed. We call this
the searchlight effect, as the enhancement depends on the orientation of the
line joining the polarizable dipoles and can be varied by changing the
frequency. For some particular polarizabilities the enhancement can actually
increase the further the polarizable dipoles are apart.


title:
The measurements of the anomalous like-sign dimuon charge asymmetry in
  $p \bar{p}$ collisions by the D\O\ Collaboration

abstract:
  In this short review we present the history, an overview of the analysis, and
some personal comments on the anomalous like-sign dimuon charge asymmetry
measurements by the D\O\ Collaboration.


title: Group actions with commensurated subsets, wallings and cubings

abstract:
  We study commensurating actions of groups and the associated properties FW
and PW, in connection with wallings, median graphs, CAT(0) cubings and
multi-ended Schreier graphs.


title:
Geometric Methods in the Analysis on Non-linear Flows in Porous Media
  (Preliminary Version)

abstract:
  Over the past few years, we developed a mathematically rigorous method to
study the dynamical processes associated to nonlinear Forchheimer flows for
slightly compressible fluids. We have proved the existence of a geometric
transformation which relates constant mean curvature surfaces and
time-invariant pressure distribution graphs constrained by the
Darcy-Forchheimer law. We therein established a direct relationship between the
CMC graph equation and a certain family of equations which we call
$g$-Forchheimer equations. The corresponding results, on fast flows and their
geometric interpretation, can be used as analytical tools in evaluating
important technological parameters in reservoir engineering.


title: Series for $1/\pi$ Using Legendre's Relation

abstract:
  We present a new method for producing series for $1/\pi$ and other constants
using Legendre's relation, starting from a generation function that can be
factorised into two elliptic $K$'s; this way we avoid much of modular theory or
creative telescoping. Many of our series involve special values of Legendre
polynomials; their relationship to the more traditional Ramanujan series is
discussed.


title: A Meta-Theory of Boundary Detection Benchmarks

abstract:
  Human labeled datasets, along with their corresponding evaluation algorithms,
play an important role in boundary detection. We here present a psychophysical
experiment that addresses the reliability of such benchmarks. To find better
remedies to evaluate the performance of any boundary detection algorithm, we
propose a computational framework to remove inappropriate human labels and
estimate the intrinsic properties of boundaries.


title:
Unambiguous discrimination of extremely similar states by a weak
  measurement

abstract:
  In this paper, we propose a method to discriminate two extremely similar
quantum states via a weak measurement. For the two states with equal prior
probabilities, the optimum discrimination probability given by
Ivanovic-Dieks-Peres limit can be achieved by our protocol with an appropriate
choice of the interaction strength. However, compared with the conventional
method for state discrimination, our approach shows the advantage of
error-tolerance by achieving a better ratio of the success probability to the
probability of error.


title: A note on the passage time of finite state Markov chains

abstract:
  Consider a Markov chain with finite state $\{0, 1, ..., d\}$. We give the
generation functions (or Laplace transforms) of absorbing (passage) time in the
following two situations : (1) the absorbing time of state $d$ when the chain
starts from any state $i$ and absorbing at state $d$; (2) the passage time of
any state $i$ when the chain starts from the stationary distribution supposed
the chain is time reversible and ergodic. Example shows that it is more
convenient compared with the existing methods, especially we can calculate the
expectation of the absorbing time directly.


title: On \Phi-Schauder frames

abstract:
  In this short note we introduce and study a particular type of Schauder
frames, namely, \Phi-Schauder frames.


title:
Inertial frames without the relativity principle: breaking Lorentz
  symmetry

abstract:
  We investigate inertial frames in the absence of Lorentz invariance,
reconsidering the usual group structure implied by the relativity principle. We
abandon the relativity principle, discarding the group structure for the
transformations between inertial frames, while requiring these transformations
to be at least linear (to preserve homogeneity). In theories with a preferred
frame (aether), the set of transformations between inertial frames forms a
groupoid/pseudogroup instead of a group, a characteristic essential to evading
the von Ignatowsky theorems. In order to understand the dynamics, we also
demonstrate that the transformation rules for energy and momentum are in
general affine. We finally focus on one specific and compelling model
implementing a minimalist violation of Lorentz invariance.


title:
A Modified Riccati Transformation for Decentralized Computation of the
  Viability Kernel Under LTI Dynamics

abstract:
  Computing the viability kernel is key in providing guarantees of safety and
proving existence of safety-preserving controllers for constrained dynamical
systems. Current numerical techniques that approximate this construct suffer
from a complexity that is exponential in the dimension of the state. We study
conditions under which a linear time-invariant (LTI) system can be suitably
decomposed into lower-dimensional subsystems so as to admit a conservative
computation of the viability kernel in a decentralized fashion in subspaces. We
then present an isomorphism that imposes these desired conditions, particularly
on two-time-scale systems. Decentralized computations are performed in the
transformed coordinates, yielding a conservative approximation of the viability
kernel in the original state space. Significant reduction of complexity can be
achieved, allowing the previously inapplicable tools to be employed for
treatment of higher-dimensional systems. We show the results on two examples
including a 6D system.


title:
New Results for the Descartes-Frenicle-Sorli Conjecture on Odd Perfect
  Numbers

abstract:
  If $N={q^k}{n^2}$ is an odd perfect number given in Eulerian form, then the
Descartes-Frenicle-Sorli conjecture predicts that $k=1$. Brown has recently
announced a proof for the inequality $q < n$, and a partial proof that $q^k <
n$ holds under many cases. In this article, we give a strategy for
strengthening Brown's result to $q^2 < n$.


title: B -> D(*) Tau Nu decays in two-Higgs-doublet models

abstract:
  A sizable excess with respect to the SM expectation has been reported
recently by the BaBar collaboration in the decay rates B -> D(*) Tau Nu,
normalized by the corresponding light lepton modes. A violation of lepton
flavor universality as suggested by this excess could be due to a charged Higgs
mediating these processes at tree level. In this talk we analyze the
implications of the observed excess within the framework of two-Higgs-doublet
models, considering also the bounds from other semileptonic and leptonic decays
of B and D(s) mesons. Prospects for B -> D(*) Tau Nu decays at future
Super-Flavor Factories are also discussed.


title:
On the specifics of the electrical conductivity anomalies in PVC
  nanocomposites

abstract:
  A qualitative model describing the "anomalous" features of the conductivity
of polymer nanocomposites, in particular, switching to the conducting state in
relatively thick (tens of microns or more) of flexible PVC films is considered.
In previously published experimental results, change of conductivity by 10 or
more orders of magnitude occurred both in the absence of external influences
(spontaneously), and under the influence of an applied electric field, as well
as other initiating factors (such as uniaxial pressure) . In a model of hopping
conduction mechanism it is shown, that switching in the conduction states under
the action of external field significantly (by orders of magnitude) below
threshold can be associated with a high-resistance state instability that
results from the sequence of "shorting" (reversible soft breakdown) of narrow
insulating gaps between regions with relatively high conductivity. Increasing
the field strength in the remaining insulating gaps ultimately leads to the
formation of a conducting channel between the external electrodes and switching
conductivity of the composite film sample in a state of high conductivity. This
cascade model is essentially based on the transition from the usual description
of the charge tunneling through single independent insulating gap to take into
account correlations between adjacent gaps. In the frame of developed model
other "anomalies" such as exponential dependence of the resistance on the
sample thickness, pressure, and other influences can be qualitative explained.
An analogy of the model with a cascading breakdown of avalanche transistors is
also considered.


title:
Phase transitions and continuously variable scaling in a chiral quenched
  disordered model

abstract:
  We elucidate the effects of chiral quenched disorder on the scaling
properties of pure systems by considering a reduced model that is a variant of
the quenched disordered cubic anisotropic O(N) model near its second order
phase transition. A generic short-ranged Gaussian disorder distribution is
considered. For distributions not invariant under spatial inversion ({hence
chiral}), the scaling exponents are found to depend continuously on a model
parameter that describes the extent of inversion symmetry breaking.
Experimental and phenomenological implications of our results are discussed.


title:
An O(N) algorithm for constructing the solution operator to 2D elliptic
  boundary value problems in the absence of body loads

abstract:
  The large sparse linear systems arising from the finite element or finite
difference discretization of elliptic PDEs can be solved directly via, e.g.,
nested dissection or multifrontal methods. Such techniques reorder the nodes in
the grid to reduce the asymptotic complexity of Gaussian elimination from
$O(N^{2})$ to $O(N^{1.5})$ for typical problems in two dimensions. It has
recently been demonstrated that the complexity can be further reduced to O(N)
by exploiting structure in the dense matrices that arise in such computations
(using, e.g., $\mathcal{H}$-matrix arithmetic). This paper demonstrates that
such \textit{accelerated} nested dissection techniques become particularly
effective for boundary value problems without body loads when the solution is
sought for several different sets of boundary data, and the solution is
required only near the boundary (as happens, e.g., in the computational
modeling of scattering problems, or in engineering design of linearly elastic
solids.


title: On the products of bipolar harmonics

abstract:
  The products of the two and three bipolar harmonics ${\cal Y}^{\ell_1
\ell_2}_{LM}({\bf r}_{31}, {\bf r}_{32})$ are represented as the finite sums of
powers of the three relative coordinates $r_{32}, r_{31}$ and $r_{21}$. The
complete (angular+radial) integrals of the products of the two and three
bipolar harmonics in the basis of exponential radial functions are expressed as
finite sums of the auxiliary three-particle integrals $\Gamma_{n,k,l}(\alpha,
\beta, \gamma)$. The formulas derived in this study can be used to accelerate
highly accurate computations of the rotationally excited (bound) states in
arbitrary three-body systems. In particular, we have constructed compact
(400-term) variational wave functions for the triplet and singlet $2P(L =
1)-$states in light two-electron atoms and ions. Highly accurate calculations
(20 - 21 stable decimal digits in the total energy) of the triplet and singlet
$2P(L = 1)-$states in the two-electron Li$^{+}$, Be$^{2+}$, B$^{3+}$ and
C$^{4+}$ ions are performed for the first time


title:
Proceedings 7th International Workshop on Computing with Terms and
  Graphs

abstract:
  This volume contains the proceedings of the Seventh International Workshop on
Computing with Terms and Graphs (TERMGRAPH 2013). The workshop took place in
Rome, Italy, on March 23rd, 2013, as part of the sixteenth edition of the
European Joint Conferences on Theory and Practice of Software (ETAPS 2013).
  Research in term and graph rewriting ranges from theoretical questions to
practical issues. Computing with graphs handles the sharing of common
subexpressions in a natural and seamless way, and improves the efficiency of
computations in space and time. Sharing is ubiquitous in several research
areas, as witnessed by the modelling of first- and higher-order term rewriting
by (acyclic or cyclic) graph rewriting, the modelling of biological or chemical
abstract machines, and the implementation techniques of programming languages:
many implementations of functional, logic, object-oriented, concurrent and
mobile calculi are based on term graphs. Term graphs are also used in automated
theorem proving and symbolic computation systems working on shared structures.
The aim of this workshop is to bring together researchers working in different
domains on term and graph transformation and to foster their interaction, to
provide a forum for presenting new ideas and work in progress, and to enable
newcomers to learn about current activities in term graph rewriting.
  These proceedings contain six accepted papers and the abstracts of two
invited talks. All submissions were subject to careful refereeing. The topics
of accepted papers range over a wide spectrum, including theoretical aspects of
term graph rewriting, concurrency, semantics as well as application issues of
term graph transformation.


title:
Quasiparticle Dynamics in Reshaped Helical Dirac Cone of Topological
  Insulators

abstract:
  Topological insulators (TIs) and graphene present two unique classes of
materials which are characterized by spin polarized (helical) and non-polarized
Dirac-cone band structures, respectively. The importance of many-body
interactions that renormalize the linear bands near Dirac point in graphene has
been well recognized and attracted much recent attention. However,
renormalization of the helical Dirac point has not been observed in TIs. Here,
we report the experimental observation of the renormalized quasi-particle
spectrum with a skewed Dirac cone in a single Bi bilayer grown on Bi2Te3
substrate, from angle-resolved photoemission spectroscopy. First-principles
band calculations indicate that the quasi-particle spectra are likely
associated with the hybridization between the extrinsic substrate-induced Dirac
states of Bi bilayer and the intrinsic surface Dirac states of Bi2Te3 film at
close energy proximity. Without such hybridization, only single-particle Dirac
spectra are observed in a single Bi bilayer grown on Bi2Se3, where the
extrinsic Dirac states Bi bilayer and the intrinsic Dirac states of Bi2Se3 are
well separated in energy. The possible origins of many-body interactions are
discussed. Our findings provide a means to manipulate topological surface
states.


title: Distributed Wear levelling of Flash Memories

abstract:
  For large scale distributed storage systems, flash memories are an excellent
choice because flash memories consume less power, take lesser floor space for a
target throughput and provide faster access to data. In a traditional
distributed filesystem, even distribution is required to ensure load-balancing,
balanced space utilisation and failure tolerance. In the presence of flash
memories, in addition, we should also ensure that the number of writes to these
different flash storage nodes are evenly distributed, to ensure even wear of
flash storage nodes, so that unpredictable failures of storage nodes are
avoided. This requires that we distribute updates and do garbage collection,
across the flash storage nodes. We have motivated the distributed wearlevelling
problem considering the replica placement algorithm for HDFS. Viewing the
wearlevelling across flash storage nodes as a distributed co-ordination
problem, we present an alternate design, to reduce the message communication
cost across participating nodes. We demonstrate the effectiveness of our design
through simulation


title: A Generalization of the Hopf-Cole Transformation

abstract:
  A generalization of the Hopf-Cole transformation and its relation to the
Burgers equation of integer order and the diffusion equation with quadratic
nonlinearity are discussed. The explicit form of a particular analytical
solution is presented. The existence of the travelling wave solution and the
interaction of nonlocal perturbation are considered. The nonlocal
generalizations of the one-dimensional diffusion equation with quadratic
nonlinearity and of the Burgers equation are analyzed.


title:
Conditional G-expectation in $\mathbb{L}^{p}$ and related It\^o's
  calculus

abstract:
  In this paper, we define a dynamically consistent conditional G-expectation
in space $\mathbb{L}^{p}$, and give the related stochastic calculus of It\^o's
type, especially get It\^o's formula for a general $C^{1,2}$-function.


title:
Highly Correlated Electron State and High-Temperature Superconductivity
  in Iron Pnictides

abstract:
  It is shown that the qualitative model of the high-temperature
superconductivity suggested earlier for cuprates and doped picene and based on
the idea that the valence electron state depends on the character of the
chemical bonds they form and on the Coulomb interaction between the electrons
is not only confirmed by the experimental data on iron pnictides but is also
improved. From the chemical point of view, the high-temperature
superconductivity is associated with additional $\pi$ bonding along chains of
covalently bonded ions via a delocalized $\pi$ orbital, just like in cuprates.
From the physical point of view, as the data on iron pnictides show, the
superconductivity is associated with a FeAs layer transition into the state
similar to a macroscopic quantum system characterized by a highly correlated
electron state, formation of two-dimensional crystals of electron pairs with
quantized energy levels, and a strong Coulomb interaction between these
crystals. Superconductivity in such a system is accomplished by a
two-dimensional Wigner crystal consisting of one-dimensional Wigner crystals
formed by bosons, i.e., singlet electron pairs that are in the same
quasi-one-dimensional state extending along the ion chain, which corresponds to
a delocalized $\pi$ orbital in chemistry. The model applicability to three
different classes of materials (cuprates, picene, iron pnictides) indicates
that it can prove useful for development of the theory of superconductivity
taking into consideraion the highly correlated state of valence electrons and
strong Coulomb interactions between the electrons.


title: Quantum logic and weak values

abstract:
  In this study, we study weak values from a quantum-logical viewpoint. In
addition, we examine the validity of the counterfactual statements of Hardy's
paradox, which are based on weak values, and we show that these statements have
not been validated. It is also shown that strange weak values may only appear
if they are not (conditional) probabilities.
  PACS numbers: 03.65.Ta, 03.65.Ud, 03.65.Ca


title: Smoothed analysis of componentwise condition numbers for sparse matrices

abstract:
  We perform a smoothed analysis of the componentwise condition numbers for
determinant computation, matrix inversion, and linear equations solving for
sparse n times n matrices. The bounds we obtain for the ex- pectations of the
logarithm of these condition numbers are, in all three cases, of the order
O(log n). As a consequence, small bounds on the smoothed loss of accuracy for
triangular linear systems follow.


title: Non-classical Correlations in the Quantum Search Algorithm

abstract:
  Entanglement lies at the heart of quantum mechanics and has no classical
analogue. It is central to the speed up achieved by quantum algorithms over
their classical counterparts. The Grover's search algorithm is one such
algorithm which enables us to achieve a quadratic speed up over any known
classical algorithm that searches for an element in an unstructured database.
Here, we analyse and quantify the effects of entanglement in the generalized
version of this algorithm for two qubits. By 'generalized', it is meant that
the use of any arbitrary single qubit unitary gate is permitted to create
superposed states. Our analysis has been firstly on a noise free environment
and secondly in the presence of noise. In the absence of noise, we establish a
relation between the concurrence and the amplitude of the final state thereby
showing the explicit effects of entanglement on the same. Moreover, the effects
of noisy channels, namely amplitude and phase damping channels are studied. We
investigate the amount of quantum correlation in the states obtained after the
phase inversion stage of the algorithm followed by interaction of those states
with the noisy environment. The quantum correlations are quantified by
geometric discord. It has been revealed that the states generated after the
effect of amplitude damping on the phase inverted states of the quantum search
algorithm possess non-zero quantum correlation even when entanglement is
absent. However, this is absent in the phase damping scenario.


title: Status report: black hole complementarity controversy

abstract:
  Black hole complementarity was a consensus among string theorists for the
interpretation of the information loss problem. However, recently some authors
find inconsistency of black hole complementarity: large N rescaling and AMPS
argument. According to AMPS, the horizon should be a firewall so that one
cannot penetrate there for consistency. There are some controversial
discussions on the firewall. Apart from these papers, the authors suggest an
assertion using a semi-regular black hole model and we conclude that the
firewall, if it exists, should affect to asymptotic observer. In addition, if
any opinion does not consider the duplication experiment and the large N
rescaling, then the argument is difficult to accept.


title: Anti-analog giant dipole resonances and the neutron skin of nuclei

abstract:
  We examine a method to determine the neutron-skin thickness of nuclei using
data on the charge-exchange anti-analog giant dipole resonance (AGDR).
Calculations performed using the relativistic proton-neutron quasiparticle
random-phase approximation (RQRPA) reproduce the isotopic trend of the
excitation energies of the AGDR, as well as that of the spin-flip giant dipole
resonances (IVSGDR), in comparison to available data for the even-even isotopes
112-124Sn. It is shown that the excitation energies of the AGDR, obtained using
a set of density-dependent effective interactions which span a range of the
symmetry energy at saturation density, supplemented with the experimental
values, provide a stringent constraint on the value of the neutron-skin
thickness. For 124Sn, in particular, we determine the value DRpn=0.21(5) fm.
The result of the present study shows that a measurement of the excitation
energy of the AGDR in (p,n) reactions using rare-isotope beams in inverse
kinematics, provides a valuable method for the determination of the
neutron-skin thickness in exotic nuclei.


title:
Further Evidence for the Accretion Disk Origination of the Double-Peaked
  Broad H$\alpha$ of 3C390.3

abstract:
  In the letter, under the widely accepted theoretical accretion disk model for
the double-peaked emitter 3C390.3, the extended disk-like BLR can be well split
into ten rings, and then the time lags between the lines from the rings and the
continuum emission are estimated, based on the observed spectra around 1995. We
can find one much strong correlation between the determined time lags (in unit
of light-day) and the flux weighted radii (in unit of ${\rm R_G}$) of the
rings, which is well consistent with the expected results through the
theoretical accretion disk model. Moreover, through the strong correlation, the
black hole masses of 3C390.3 are independently estimated as $\sim10^9{\rm
M_{\odot}}$, the same as the reported black hole masses in the literature. The
consistencies provide further evidence to strongly support the accretion disk
origination of the double-peaked broad balmer lines of 3C390.3.


title: On learning parametric-output HMMs

abstract:
  We present a novel approach for learning an HMM whose outputs are distributed
according to a parametric family. This is done by {\em decoupling} the learning
task into two steps: first estimating the output parameters, and then
estimating the hidden states transition probabilities. The first step is
accomplished by fitting a mixture model to the output stationary distribution.
Given the parameters of this mixture model, the second step is formulated as
the solution of an easily solvable convex quadratic program. We provide an
error analysis for the estimated transition probabilities and show they are
robust to small perturbations in the estimates of the mixture parameters.
Finally, we support our analysis with some encouraging empirical results.


title: Integrable evolution equations with constant separant

abstract:
  The survey provides classification results for integrable one-field evolution
equations of orders 2, 3 and 5 with the constant separant. The classification
is based on necessary integrability conditions following from the existence of
the formal recursion operator for integrable equations. Recurrent formulas for
the whole infinite sequence of necessary conditions are presented for the first
time. The most of the classification statements can be found in papers by S.I.
Svinilupov and V.V. Sokolov but the proofs have never been published before.
The result concerning the fifth order equations is stronger than obtained
before.


title:
Optimal dividends problem with a terminal value for spectrally positive
  Levy processes

abstract:
  In this paper we consider a modified version of the classical optimal
dividends problem of de Finetti in which the dividend payments subject to a
penalty at ruin. We assume that the risk process is modeled by a general
spectrally positive Levy process before dividends are deducted. Using the
fluctuation theory of spectrally positive Levy processes we give an explicit
expression of the value function of a barrier strategy. Subsequently we show
that a barrier strategy is the optimal strategy among all admissible ones. Our
work is motivated by the recent work of Bayraktar, Kyprianou and Yamazaki
(2013).


title: Nonidentical protons

abstract:
  We have calculated the proton charge radius by assuming that the real proton
radius is not unique and the radii are randomly distributed in a certain range.
This is performed by averaging the elastic electron-proton differential cross
section over the form factor cut-off. By using a dipole form factor and fitting
the middle value of the cut-off to the low $Q^2$ Mainz data, we found the
lowest $\chi^2/N$ for a cut-off $\Lambda=0.8203\pm 0.0003$ GeV, which
corresponds to a proton charge radius $r_E=0.8333\pm 0.0004$ fm. The result is
compatible with the recent precision measurement of the Lamb shift in muonic
hydrogen as well as recent calculations using more sophisticated techniques.
Our result indicates that the relative variation of the form factor cut-off
should be around 21.5%. Based on this result we have investigated effects of
the nucleon radius variation on the symmetric nuclear matter (SNM) and the
neutron star matter (NSM) by considering the excluded volume effect in our
calculation. The mass-radius relation of neutron star is found to be sensitive
to this variation. The nucleon effective mass in the SNM as well as the
equation of state of both the SNM and the NSM exhibit a similar sensitivity.


title: Magneto-reheating constraints from curvature perturbations

abstract:
  As additional perturbative degrees of freedom, it is known that magnetic
fields of inflationary origin can source curvature perturbations on
super-Hubble scales. By requiring the magnetic generated curvature to remain
smaller than its inflationary adiabatic counterpart during inflation and
reheating, we derive new constraints on the maximal field value today, the
reheating energy scale and its equation of state parameter. These bounds end up
being stronger by a few order of magnitude than those associated with a
possible backreaction of the magnetic field onto the background. Our results
are readily applicable to any slow-roll single field inflationary models and
any magnetic field having its energy density scaling as a^gamma during
inflation. As an illustrative example, massive inflation is found to remain
compatible with a magnetic field today Bo = 5 x 10^(-15) G for some values of
gamma only if a matter dominated reheating takes place at energies larger than
10^5 GeV. Conversely, assuming gamma=-1, massive inflation followed by a matter
dominated reheating cannot explain large scale magnetic fields larger than
10^(-20) G today.


title: A Twisted Version of the Classifying Space Functor

abstract:
  It is known that there is a weak-equivalence between the geometric
realization of a simplicially enriched small category and its cofibrant
replacement [12]. In this paper, we show that when only small categories are
considered there exists a homeomorphism between these geometric realizations.
We also discuss the naturality of these homoemorphisms. The inclusion of the
category of small categories to the category of simplicially enriched
categories, the cofibrant replacement of simplicially enriched categories, and
the geometric realization of simplicially enriched categories are three
composable functors. Hence one can ask if the collection of all these
homeomorphisms gives a natural transformation from the composition of these
three functors to the classifying space functor. We show that this is almost
the case and that this composition can be considered as some twisted version of
the classifying space functor. \end{abstract}


title:
Baryon acoustic oscillations with the cross-correlation of spectroscopic
  and photometric samples

abstract:
  The baryon acoustic oscillation (BAO) experiment requires a sufficiently
dense sampling of large-scale structure tracers with spectroscopic redshift,
which is observationally expensive especially at high redshifts $z\simgt 1$.
Here we present an alternative route of the BAO analysis that uses the
cross-correlation of sparse spectroscopic tracers with a much denser
photometric sample, where the spectroscopic tracers can be quasars or bright,
rare galaxies that are easier to access spectroscopically. We show that
measurements of the cross-correlation as a function of the transverse comoving
separation rather than the angular separation avoid a smearing of the BAO
feature without mixing the different scales at different redshifts in the
projection, even for a wide redshift slice $\Delta z\simeq 1$. The bias,
scatter, and catastrophic redshift errors of the photometric sample affect only
the overall normalization of the cross-correlation which can be marginalized
over when constraining the angular diameter distance. As a specific example, we
forecast an expected accuracy of the BAO geometrical test via the
cross-correlation of the SDSS and BOSS spectroscopic quasar sample with a dense
photometric galaxy sample that is assumed to have a full overlap with the
SDSS/BOSS survey region. We show that this cross-correlation BAO analysis
allows us to measure the angular diameter distances to a fractional accuracy of
about 10% at each redshift bin over $1\simlt z\simlt 3$, if the photometric
redshift errors of the galaxies, $\sigma_z/(1+z)$, are better than 10-20%
level.


title: On new approaches to the study of nanosystems

abstract:
  Quantum nanosystems are exremely diverse and often very complicated. That is
why new methods of a simple description of such systems ensuring the retention
of essential part of information at small numbers of parameters are needed. We
consider several approaches to such reduced description. Besides we warn
against using of one new incorrect approach.


title:
Application of the Abel Equation of the 1st kind to an inflation
  analysis of non-exactly solvable cosmological models

abstract:
  In this paper we revisit the relationship between the Einstein--Friedman and
the Abel equations to demonstrate how it might be applied to the inflationary
analysis in a flat Friedman universe filled with a real-valued scalar field.
The analysis is performed for three distinct cases of polynomial potentials. As
a result of a numeric integration of Abel equation, the necessary and
sufficient conditions for both slow-rolling and inflation proper are estimated
with respect to the initial value of the field. In addition, the relationship
between the slow-rolling condition and the inflation is ascertained.


title:
Study on the Fermi level of microstructured Silicon with impurities
  introduced by chalcogenides and their affect on solar cell efficiency

abstract:
  Microstructured Silicon, which is obtained by irradiating the surface of a
Silicon wafer with femtosecond laser pulses under certain circumstances, has
unusual optical properties such as the strong absorption of light with
wavelength from 0.25{\mu}m to 17{\mu}m. So it holds great promise in the
intermediate band solar cell (IBSC). Some articles have discussed the
electronic structure associating with simple substitutional impurities in
Silicon introduced by chalcogenides. And on this basis, after high temperature
annealing treatment, we establish the mode of impurity levels of
microstructured Silicon introduced by sulfur and oxygen. Using generalized
statistics of multi-level,we analyze the probability of electronic in all local
energy levels and the relationship among Fermi level, temperature and the
density of impurities. Then the theoretical conversion efficiency of the
corresponding IBSC is discussed with the Detailed Balance Theory. And the issue
of making high efficiency solar cells based on femtosecond laser
microstructured Silicon is discussed in detail.


title: On dentability in locally convex vector spaces

abstract:
  For a locally convex vector space (l.c.v.s.) $E$ and an absolutely convex
neighborhood $V$ of zero, a bounded subset $A$ of $E$ is said to be
$V$-dentable (respectively, $V$-f-dentable) if for any $\epsilon>0$ there
exists an $x\in A$ so that $$x\notin \bar{co} (A\setminus (x+\epsilon V)) $$
(respectively, so that $$ x\notin {co} (A\setminus (x+\epsilon V))). $$ Here,
"$\bar{co}$" denotes the closure in $E$ of the convex hull of a set. We present
a theorem which says that for a wide class of bounded subsets $B$ of locally
convex vector spaces the following is true: $(V)$ every subset of $B$ is
$V$-dentable if and only if every subset of $B$ is $V$-f-dentable. The proof is
purely geometrical and independent of any related facts. As a consequence (in
the particular case where $B$ is complete convex bounded metrizable subset of a
l.c.v.s.), we obtain a positive solution to a 1978-hypothesis of Elias Saab
(see p. 290 in "On the Radon-Nikodym property in a class of locally convex
spaces", Pacific J. Math. 75, No. 1, 1978, 281-291).


title:
Generalized variational procedure: An application to non-perturbative
  QCD

abstract:
  We present a generalized variational procedure oriented to the algebraic
solution of many body Hamiltonians expressed in bosonic and fermionic
variables. The method specializes in the non-perturbative regime of the
solutions. As an example, we focus on the application of the method to
non-perturbative QCD.


title: Twists of automorphic L-functions at the central point

abstract:
  We study the nonvanishing of twists of automorphic L-functions at the centre
of the critical strip. Given a primitive character \chi modulo D satisfying
some technical conditions, we prove that the twisted L-functions L(f.\chi,s) do
not vanish at s=1/2 for a positive proportion of primitive forms of weight 2
and level q, for large prime q. We also investigate the central values of high
derivatives of L(f.\chi,s), and from that derive an upper bound for the average
analytic rank of the studied L-functions.


title:
On the Convergence of the Self-Consistent Field Iteration in Kohn-Sham
  Density Functional Theory

abstract:
  It is well known that the self-consistent field (SCF) iteration for solving
the Kohn-Sham (KS) equation often fails to converge, yet there is no clear
explanation. In this paper, we investigate the SCF iteration from the
perspective of minimizing the corresponding KS total energy functional. By
analyzing the second-order Taylor expansion of the KS total energy functional
and estimating the relationship between the Hamiltonian and the part of the
Hessian which is not used in the SCF iteration, we are able to prove global
convergence from an arbitrary initial point and local linear convergence from
an initial point sufficiently close to the solution of the KS equation under
assumptions that the gap between the occupied states and unoccupied states is
sufficiently large and the second-order derivatives of the exchange correlation
functional are uniformly bounded from above. Although these conditions are very
stringent and are almost never satisfied in reality, our analysis is
interesting in the sense that it provides a qualitative prediction of the
behavior of the SCF iteration.


title: On the structural properties of an efficient feedback law

abstract:
  We investigate some structural properties of an efficient feedback law that
stabilize linear time-reversible systems with an arbitrarily large decay rate.
After giving a short proof of the generation of a group by the closed-loop
operator, we focus on the domain of the infinitesimal generator in order to
illustrate the difference bewteen a distributed control and a boundary control,
the latter being technically more complex. We also give a new proof of the
exponential decay of the solutions and we provide an explanation of the higher
decay rate observed in some experiments.


title:
Transport across a junction of topological insulators and a
  superconductor

abstract:
  We study transport across a line junction lying between two orthogonal
topological insulator surfaces and a superconductor which can have either
s-wave (spin-singlet) or p-wave (spin-triplet) pairing symmetry. We present a
formalism for studying the effect of a general time-reversal invariant barrier
at the junction and show that such a barrier can be completely described by
three arbitrary parameters. We compute the charge and the spin conductance
across such a junction and study their behaviors as a function of the bias
voltage applied across the junction and the three parameters used to
characterize the barrier. We find that the presence of topological insulators
and a superconductor leads to both Dirac and Schrodinger-like features in
charge and spin conductances. We discuss the effect of bound states on the
superconducting side of the barrier on the conductance; in particular, we show
that for triplet p-wave superconductors such a junction may be used to
determine the spin state of its Cooper pairs. Our study reveals that there is a
non-zero spin conductance for some particular spin states of the triplet Cooper
pairs; this is an effect of the topological insulators which break the spin
rotation symmetry. Finally, we find an unusual satellite peak (in addition to
the usual zero bias peak) in the spin conductance for p-wave symmetry of the
superconductor order parameter.


title:
Are hyperon resonances required in the elementary $K^+\Lambda$
  photoproduction?

abstract:
  We have investigated the role of hyperon resonances in the kaon
photoproduction process, $\gamma p\to K^+\Lambda$, by using a covariant isobar
model. To this end, new experimental data are used in the fitting process,
whereas the old SAPHIR 1998 data are also used for comparison. The result
indicates that the $\Lambda(1600)P_{01}$ and $\Lambda(1810)P_{01}$ hyperon
resonances can significantly reduce the $\chi^2$ and, simultaneously, can
increase the hadronic form factor cut-off in the background terms. This finding
is different from the result of the previous studies, which showed that the
$\Lambda(1800)S_{01}$ was important for this purpose, instead of the
$\Lambda(1600)P_{01}$.


title:
Dynamics of a free boundary problem with curvature modeling
  electrostatic MEMS

abstract:
  The dynamics of a free boundary problem for electrostatically actuated
microelectromechanical systems (MEMS) is investigated. The model couples the
electric potential to the deformation of the membrane, the deflection of the
membrane being caused by application of a voltage difference across the device.
More precisely, the electrostatic potential is a harmonic function in the
angular domain that is partly bounded by the deformable membrane. The gradient
trace of the electric potential on this free boundary part acts as a source
term in the governing equation for the membrane deformation. The main feature
of the model considered herein is that, unlike most previous research, the
small deformation assumption is dropped, and curvature for the deformation of
the membrane is taken into account what leads to a quasilinear parabolic
equation. The free boundary problem is shown to be well-posed, locally in time
for arbitrary voltage values and globally in time for small voltages values.
Furthermore, existence of asymptotically stable steady-state configurations is
proved in case of small voltage values as well as non-existence of
steady-states if the applied voltage difference is large. Finally, convergence
of solutions of the free boundary problem to the solutions of the
well-established small aspect ratio model is shown.


title:
Improvement of the matching of the exact solution and variational
  approaches in an interacting two-fermion system

abstract:
  A more reasonable trial ground state wave function is constructed for the
relative motion of an interacting two-fermion system in a 1D harmonic
potential. At the boundaries both the wave function and its first derivative
are continuous and the quasi-momentum is determined by a more practical
constraint condition which associates two variational parameters. The upper
bound of the ground state energy is obtained by applying the variational
principle to the expectation value of the Hamiltonian of relative motion on the
trial wave function. The resulted energy and wave function show better
agreement with the analytical solution than the original proposal.


title: U(infinity) Gauge Theory from Higher Dimensions

abstract:
  We show that classical U(infinity) gauge theories can be obtained from the
dimensional reduction of a certain class of higher-derivative theories. In
general, the exact symmetry is attained in the limit of degenerate metric;
otherwise, the infinite-dimensional symmetry can be taken as spontaneously
broken. Monopole solutions are examined in the model for scalar and gauge
fields. An extension to gravity is also discussed.


title:
Pareto genealogies arising from a Poisson branching evolution model with
  selection

abstract:
  We study a class of coalescents derived from a sampling procedure out of N
i.i.d. Pareto(alpha) random variables, normalized by their sum, including
beta-size-biasing on total length effects (beta < alpha). Depending on the
range of alpha, we derive the large N limit coalescents structure, leading
either to a discrete-time Poisson-Dirichlet(alpha,-beta) Xi-coalescent (alpha
in [0,1)), or to a family of continuous-time Beta(2-alpha,alpha-beta)
Lambda-coalescents (alpha in [1,2)), or to the Kingman coalescent (alpha geq
2). We indicate that this class of coalescent processes (and their scaling
limits) may be viewed as the genealogical processes of some forward in time
evolving branching population models including selection effects. In such
constant-size population models, the reproduction step, which is based on a
fitness-dependent Poisson Point Process with scaling power-law(alpha)intensity,
is coupled to a selection step consisting of sorting out the N fittest
individuals issued from the reproduction step.


title: A Fast Template Based Heuristic For Global Multiple Sequence Alignment

abstract:
  Advances in bio-technology have made available massive amounts of functional,
structural and genomic data for many biological sequences. This increased
availability of heterogeneous biological data has resulted in biological
applications where a multiple sequence alignment (msa) is required for aligning
similar features, where a feature is described in structural, functional or
evolutionary terms. In these applications, for a given set of sequences,
depending on the feature of interest the optimal msa is likely to be different,
and sequence similarity can only be used as a rough initial estimate on the
accuracy of an msa. This has motivated the growth in template based heuristics
that supplement the sequence information with evolutionary, structural and
functional data and exploit feature similarity instead of sequence similarity
to construct multiple sequence alignments that are biologically more accurate.
However, current frameworks for designing template based heuristics do not
allow the user to explicitly specify information that can help to classify
features into types and associate weights signifying the relative importance of
a feature with respect to other features. In this paper, we first provide a
mechanism where as a part of the template information the user can explicitly
specify for each feature, its type, and weight. The type is to classify the
features into different categories based on their characteristics and the
weight signifies the relative importance of a feature with respect to other
features in that sequence. Second, we exploit the above information to define
scoring models for pair-wise sequence alignment that assume segment
conservation as opposed to single character (residue) conservation. Finally, we
present a fast progressive alignment based heuristic framework that helps in
constructing a global msa efficiently.


title: Phoneme discrimination using KS algebra I

abstract:
  In our work we define a new algebra of operators as a substitute for fuzzy
logic. Its primary purpose is for construction of binary discriminators for
phonemes based on spectral content. It is optimized for design of
non-parametric computational circuits, and makes uses of 4 operations: $\min$,
$\max$, the difference and generalized additively homogenuous means.


title:
Construction of new scalar field models from the standard $\phi^4$
  theory

abstract:
  In this work we study models described by a single real scalar field in
two-dimensional space-time, using the deformation procedure to propose and
investigate new families of models and their kink solutions.


title:
Stochastic gravitational wave background from hydrodynamic turbulence in
  differentially rotating neutron stars

abstract:
  Hydrodynamic turbulence driven by crust-core differential rotation imposes a
fundamental noise floor on gravitational wave observations of neutron stars.
The gravitational wave emission peaks at the Kolmogorov decoherence frequency
which, for reasonable values of the crust-core shear, \Delta\Omega, occurs near
the most sensitive part of the frequency band for ground-based, long-baseline
interferometers. We calculate the energy density spectrum of the stochastic
gravitational wave background from a cosmological population of turbulent
neutron stars generalising previous calculations for individual sources. The
spectrum resembles a piecewise power law,
\Omega_{gw}(\nu)=\Omega_{\alpha}\nu^{\alpha}, with \alpha=-1 and 7 above and
below the decoherence frequency respectively, and its normalisation scales as
\Omega_{\alpha}\propto(\Delta\Omega)^{7}. Non-detection of a stochastic signal
by Initial LIGO implies an upper limit on \Delta\Omega and hence by implication
on the internal relaxation time-scale for the crust and core to come into
co-rotation, \tau_{d}=\Delta\Omega/\dot{\Omega}, where \dot{\Omega} is the
observed electromagnetic spin-down rate, with \tau_{d}\lesssim 10^{7} yr for
accreting millisecond pulsars and \tau_{d}\lesssim 10^{5} yr for radio-loud
pulsars. Target limits on \tau_{d} are also estimated for future detectors,
namely Advanced LIGO and the Einstein Telescope, and are found to be
astrophysically interesting.


title: Local moment formation and Kondo screening in impurity trimers

abstract:
  We study theoretically a triangular cluster of three magnetic impurities,
hybridizing locally with conduction electrons of a metallic host. Such a
cluster is the simplest to exhibit frustration - an important generic feature
of many complex molecular systems in which different interactions compete.
Here, low-energy doublet states of the trimer are favored by effective exchange
interactions produced by strong electronic repulsion in localized impurity
orbitals. Parity symmetry protects a level-crossing of such states on tuning
microscopic parameters, while an avoided crossing arises in the general
distorted case. On coupling to a metallic host, the behavior is shown to be
immensely rich, since collective quantum many-body effects now also compete. In
particular, impurity degrees of freedom are totally screened at low
temperatures in a Kondo-screened Fermi liquid phase, while degenerate ground
states persist in a local moment phase. Local frustration drives the quantum
phase transition between the two, which may be first order or of
Kosterlitz-Thouless type, depending on symmetries. Unusual mechanisms for local
moment formation and Kondo screening are found, due to the orbital structure of
the impurity trimer. Our results are of relevance for triple quantum dot
devices. The problem is studied by a combination of analytical arguments and
the numerical renormalization group.


title: The LHCb VELO Upgrade

abstract:
  LHCb is a forward spectrometer experiment dedicated to the study of new
physics in the decays of beauty and charm hadrons produced in proton collisions
at the Large Hadron Collider (LHC) at CERN.
  The VErtex LOcator (VELO) is the microstrip silicon detector surrounding the
interaction point, providing tracking and vertexing measurements. The upgrade
of the LHCb experiment, planned for 2018, will increase the luminosity up to
$\rm 2\times10^{33}\ cm^{-2}s^{-1}$ and will perform the readout as a
trigger-less system with an event rate of 40 MHz. Extremely non-uniform
radiation doses will reach up to $\rm 5 \times 10^{15}$ 1 MeV$\rm n_{eq}/cm^2$
in the innermost regions of the VELO sensors, and the output data bandwidth
will be increased by a factor of 40. An upgraded detector is under development
based in a pixel sensor of the Timepix/Medipix family, with 55 x 55 $\rm \mu
m^2$ pixels. In addition a microstrip solution with finer pitch, higher
granularity and thinner than the current detector is being developed in
parallel.
  The current status of the VELO upgrade program will be described together
with recent testbeam results.


title:
Parametrized KAM Theorem for Differentiable Hamiltonian Vector Fields
  without Action-Angle Variables

abstract:
  We proved a parametrized KAM theorem in Hamiltonian system which has
differentiable Hamiltonian without action-angle coordinates. It is a
generalization of the result of [Llave et al. 2005] that deals with real
analytic Hamiltonians.


title: From dynamical systems to renormalization

abstract:
  We study in this paper logarithmic derivatives associated to derivations on
graded complete Lie algebra, as well as the existence of inverses. These
logarithmic derivatives, when invertible, generalize the exp-log correspondence
between a Lie algebra and its Lie group. Such correspondences occur naturally
in the study of dynamical systems when dealing with the linearization of vector
fields and the non-linearizability of a resonant vector fields corresponds to
the non-invertibility of a logarithmic derivative and to the existence of
normal forms. These concepts, stemming from the theory of dynamical systems,
can be rephrased in the abstract setting of Lie algebra and the same
difficulties as in perturbative quantum field theory (pQFT) arise here.
Surprisingly, one can adopt the same ideas as in pQFT with fruitful results
such as new constructions of normal forms with the help of the Birkhoff
decomposition. The analogy goes even further (locality of counter terms, choice
of a renormalization scheme) and shall lead to more interactions between
dynamical systems and quantum field theory.


title:
L-packets and formal degrees for SL_2(K) with K a local function field
  of characteristic 2

abstract:
  Let G = SL_2(K) with K a local function field of characteristic 2. We review
Artin-Schreier theory for the field K, and show that this leads to a
parametrization of L-packets in the smooth dual of G. We relate this to a
recent geometric conjecture. The L-packets in the principal series are
parametrized by quadratic extensions, and the supercuspidal L-packets by
biquadratic extensions. We compute the formal degrees of the elements in the
supercuspidal packets.


title: Sperner's problem for G-independent families

abstract:
  Given a graph G, let Q(G) denote the collection of all independent
(edge-free) sets of vertices in G. We consider the problem of determining the
size of a largest antichain in Q(G).
  When G is the edge-less graph, this problem is resolved by Sperner's Theorem.
In this paper, we focus on the case where G is the path of length n-1, proving
the size of a maximal antichain is of the same order as the size of a largest
layer of Q(G).


title: VLBI imaging throughout the primary beam using accurate UV shifting

abstract:
  For Very Long Baseline Interferometry (VLBI), the fringe spacing is extremely
narrow compared to the field of view imposed by the primary beam of each
element. This means that an extremely large number of resolution units can
potentially be imaged from a single observation.
  We implement and test a technique for efficiently and accurately imaging
large VLBI datasets. The DiFX software correlator is used to generate a dataset
with extremely high time and frequency resolution. This large dataset is then
transformed and averaged multiple times to generate many smaller datasets, each
with a phase centre located at a different area of interest.
  Results of an 8.4 GHz four-station VLBI observation of a field containing
multiple sources are presented. Observations of the calibrator 3C345 were used
for preliminary tests of accuracy of the shifting algorithm. A high level of
accuracy was achieved, making the method suitable even for the most demanding
astrometric VLBI observations. One target source (1320+299A) was detected and
was used as a phase-reference calibrator in searching for further detections.
An image containing 13 billion pixels was constructed by independently imaging
782 visibility datasets covering the entire primary beam of the array.
  Current implementations of this algorithm and possible future developments in
VLBI data analysis are discussed.


title:
Dimethyl ether in its ground state, v=0, and lowest two torsionally
  excited states, v11=1 and v15=1, in the high-mass star-forming region
  G327.3-0.6

abstract:
  The goal of this paper is to determine the respective importance of solid
state vs. gas phase reactions for the formation of dimethyl ether. This is done
by a detailed analysis of the excitation properties of the ground state and the
torsionally excited states, v11=1 and v15=1, toward the high-mass star-forming
region G327.3-0.6. With the Atacama Pathfinder EXperiment 12 m submillimeter
telescope, we performed a spectral line survey. The observed spectrum is
modeled assuming local thermal equilibrium. CH3OCH3 has been detected in the
ground state, and in the torsionally excited states v11=1 and v15=1, for which
lines have been detected here for the first time. The emission is modeled with
an isothermal source structure as well as with a non-uniform spherical
structure. For non-uniform source models one abundance jump for dimethyl ether
is sufficient to fit the emission, but two components are needed for the
isothermal models. This suggests that dimethyl ether is present in an extended
region of the envelope and traces a non-uniform density and temperature
structure. Both types of models furthermore suggest that most dimethyl ether is
present in gas that is warmer than 100 K, but a smaller fraction of 5%-28% is
present at temperatures between 70 and 100 K. The dimethyl ether present in
this cooler gas is likely formed in the solid state, while gas phase formation
probably is dominant above 100 K. Finally, the v11=1 and v15=1 torsionally
excited states are easily excited under the density and temperature conditions
in G327.3-0.6 and will thus very likely be detectable in other hot cores as
well.


title: On coherent systems with fixed determinant

abstract:
  Over the past 20 years, a great deal of work has been done on the moduli
spaces of coherent systems on algebraic curves. Until recently, however, there
has been very little work on the fixed determinant case, except for the special
case of rank 2 and canonical determinant. This situation has changed due to two
papers of B. Osserman, who has obtained lower bounds for the dimensions of the
fixed determinant moduli spaces in some cases. Our object in this paper is to
show that some of Osserman's bounds are sharp.


title: FO Model Checking of Interval Graphs

abstract:
  We study the computational complexity of the FO model checking problem on
interval graphs, i.e., intersection graphs of intervals on the real line. The
main positive result is that FO model checking and successor-invariant FO model
checking can be solved in time O(n log n) for n-vertex interval graphs with
representations containing only intervals with lengths from a prescribed finite
set. We complement this result by showing that the same is not true if the
lengths are restricted to any set that is dense in an open subset, e.g., in the
set $(1, 1 + \varepsilon)$.


title: Digital Cavities and Their Potential Applications

abstract:
  The concept of a digital cavity is presented. The functionality of a tunable
radio-frequency/microwave cavity with unrestricted Q-factor is implemented. The
theoretical aspects of the cavity and its potential applications in high
resolution spectroscopy and synchronization of clocks together with examples in
signal processing and data acquisition are discussed.


title: Ordered Exchange Graphs

abstract:
  The exchange graph of a cluster algebra encodes the combinatorics of
mutations of clusters. Through the recent "categorifications" of cluster
algebras using representation theory one obtains a whole variety of exchange
graphs associated with objects such as a finite-dimensional algebra or a
differential graded algebra concentrated in non-positive degrees. These
constructions often come from variations of the concept of tilting, the
vertices of the exchange graph being torsion pairs, t-structures, silting
objects, support $\tau$-tilting modules and so on. All these exchange graphs
stemming from representation theory have the additional feature that they are
the Hasse quiver of a partial order which is naturally defined for the objects.
In this sense, the exchange graphs studied in this article can be considered as
a generalization or as a completion of the poset of tilting modules which has
been studied by Happel and Unger. The goal of this article is to axiomatize the
thus obtained structure of an ordered exchange graph, to present the various
constructions of ordered exchange graphs and to relate them among each other.


title: Invariant functionals and Zamolodchikovs' integral

abstract:
  We calculate a Zamolodchikovs' triple integral by the Bernstein-Reznikov
method.


title:
Drift parameter estimation for fractional Ornstein-Uhlenbeck process of
  the Second Kind

abstract:
  Fractional Ornstein-Uhlenbeck process of the second kind $(\text{fOU}_{2})$
is solution of the Langevin equation $\mathrm{d}X_t = -\theta
X_t\,\mathrm{d}t+\mathrm{d}Y_t^{(1)}, \ \theta >0$ with driving noise $
Y_t^{(1)} := \int^t_0 e^{-s} \,\mathrm{d}B_{a_s}; \ a_t= H e^{\frac{t}{H}}$
where $B$ is a fractional Brownian motion with Hurst parameter $H \in (0,1)$.
In this article, in the case $H>1/2$, we prove that the least squares estimator
$\hat{\theta}_T$ introduced in [\cite{h-n}, Statist. Probab. Lett. 80, no.
11-12, 1030-1038], provides a consistent estimator. Moreover, using central
limit theorem for multiple Wiener integrals, we prove asymptotic normality of
the estimator valid for the whole range $H \in(1/2,1)$.


title:
Delta and Omega electromagnetic form factors in a three-body covariant
  Bethe-Salpeter approach

abstract:
  The electromagnetic form factors of the Delta and Omega baryons are
calculated in the framework of Poincare-covariant bound-state equations. The
quark-quark interaction is truncated to a single dressed-gluon exchange where
for the dressings we use two different models and compare the results. The
calculation predicts an oblate shape for the electric charge distribution and a
prolate shape for the magnetic dipole distribution. We also identify the
necessity of including pion-cloud corrections at low photon-momentum transfer.


title:
Studies of waveform requirements for intermediate mass-ratio coalescence
  searches with advanced detectors

abstract:
  The coalescence of a stellar-mass compact object into an intermediate-mass
black hole (intermediate mass-ratio coalescence; IMRAC) is an important
astrophysical source for ground-based gravitational-wave interferometers in the
so-called advanced configuration. However, the ability to carry out effective
matched-filter based searches for these systems is limited by the lack of
reliable waveforms. Here we consider binaries in which the intermediate-mass
black hole has mass in the range 24 - 200 solar masses with a stellar-mass
companion having masses in the range 1.4 - 18.5 solar masses. In addition, we
constrain the mass ratios, q, of the binaries to be in the range 1/140 < q <
1/10 and we restrict our study to the case of circular binaries with
non-spinning components. We investigate the relative contribution to the
signal-to-noise ratio (SNR) of the three different phases of the coalescence:
inspiral, merger and ringdown. We show that merger and ringdown contribute to a
substantial fraction of the total SNR over a large portion of the mass
parameter space, although in a limited portion the SNR is dominated by the
inspiral phase. We further identify three regions in the IMRAC mass-space in
which: (i) inspiral-only searches could be performed with losses in detection
rates L in the range 10% < L < 27%, (ii) searches based on inspiral-only
templates lead to a loss in detection rates in the range 27% < L < 50%$, and
(iii) templates that include merger and ringdown are essential to prevent
losses in detection rates greater than 50%. We investigate the effectiveness
with which the inspiral-only portion of the IMRAC waveform space is covered by
comparing several existing waveform families in this regime. Our results
reinforce the importance of extensive numerical relativity simulations of
IMRACs and the need for further studies of suitable approximation schemes in
this mass range.


title: On the heat kernel and the Dirichlet form of Liouville Brownian Motion

abstract:
  In \cite{GRV}, a Feller process called Liouville Brownian motion on $\R^2$
has been introduced. It can be seen as a Brownian motion evolving in a random
geometry given formally by the exponential of a (massive) Gaussian Free Field
$e^{\gamma X}$ and is the right diffusion process to consider regarding
2d-Liouville quantum gravity. In this note, we discuss the construction of the
associated Dirichlet form, following essentially \cite{fuku} and the techniques
introduced in \cite{GRV}. Then we carry out the analysis of the Liouville
resolvent. In particular, we prove that it is strong Feller, thus obtaining the
existence of the Liouville heat kernel via a non-trivial theorem of Fukushima
and al.
  One of the motivations which led to introduce the Liouville Brownian motion
in \cite{GRV} was to investigate the puzzling Liouville metric through the eyes
of this new stochastic process. One possible approach was to use the theory
developed for example in \cite{stollmann,sturm1,sturm2}, whose aim is to
capture the "geometry" of the underlying space out of the Dirichlet form of a
process living on that space. More precisely, under some mild hypothesis on the
regularity of the Dirichlet form, they provide an intrinsic metric which is
interpreted as an extension of Riemannian geometry applicable to non
differential structures. We prove that the needed mild hypotheses are satisfied
but that the associated intrinsic metric unfortunately vanishes, thus showing
that renormalization theory remains out of reach of the metric aspect of
Dirichlet forms.


title:
Observational constraints on viable f(R) parametrizations with
  geometrical and dynamical probes

abstract:
  We demonstrate that a wide range of viable f(R) parameterizations (including
the Hu & Sawicki and the Starobinsky models) can be expressed as perturbations
deviating from the LCDM Lagrangian. We constrain the deviation parameter b
using a combination of geometrical and dynamical observational probes. In
particular, we perform a joint likelihood analysis of the recent Supernovae
Type Ia data, the Cosmic Microwave Background shift parameters, the Baryonic
Acoustic Oscillations and the growth rate data provided by the various galaxy
surveys. This analysis provides constraints for the following parameters: the
matter density Omega_{m0}, the deviation from LCDM parameter b and the growth
index gamma(z). We parametrize the growth index gamma(z) in three manners
(constant, Taylor expansion around z=0, and Taylor expansion around the scale
factor). We point out the numerical difficulty for solving the generalized f(R)
Friedman equation at high redshifts due to stiffness of the resulting ordinary
differential equation. We resolve this problem by constructing an efficient
analytical perturbative method in the deviation parameter b. We demonstrate
that this method is highly accurate, by comparing the resulting analytical
expressions for the Hubble parameter, with the numerical solutions at low and
intermediate redshifts. Surprisingly, despite of its perturbative nature, the
accuracy of the method persists even for values of b that are of O(1).


title: Actomyosin contractility rotates the cell nucleus

abstract:
  The nucleus of the eukaryotic cell functions amidst active cytoskeletal
filaments, but its response to the stresses carried by these filaments is
largely unexplored. We report here the results of studies of the translational
and rotational dynamics of the nuclei of single fibroblast cells, with the
effects of cell migration suppressed by plating onto fibronectin-coated
micro-fabricated patterns. Patterns of the same area but different shapes
and/or aspect ratio were used to study the effect of cell geometry on the
dynamics. On circles, squares and equilateral triangles, the nucleus undergoes
persistent rotational motion, while on high-aspect-ratio rectangles of the same
area it moves only back and forth. The circle and the triangle showed
respectively the largest and the smallest angular speed. We show that our
observations can be understood through a hydrodynamic approach in which the
nucleus is treated as a highly viscous inclusion residing in a less viscous
fluid of orientable filaments endowed with active stresses. Lowering actin
contractility selectively by introducing blebbistatin at low concentrations
drastically reduced the speed and persistence time of the angular motion of the
nucleus. Time-lapse imaging of actin revealed a correlated hydrodynamic flow
around the nucleus, with profile and magnitude consistent with the results of
our theoretical approach. Coherent intracellular flows and consequent nuclear
rotation thus appear to be a generic property that cells must balance by
specific mechanisms in order to maintain nuclear homeostasis.


title:
Probing the Earliest Stage of Protostellar Evolution -- Barnard 1-bN and
  Barnard 1-bS

abstract:
  Two submm/mm sources in the Barnard 1b (B1-b) core, B1-bN and B1-bS, have
been observed with the Submillimeter Array (SMA) and the Submillimeter
Telescope (SMT). The 1.1 mm continuum map obtained with the SMA reveals that
the two sources contain spatially compact components, suggesting that they
harbor protostars. The N2D+ and N2H+ J=3-2 maps were obtained by combining the
SMA and SMT data. The N2D+ map clearly shows two peaks at the continuum
positions. The N2H+ map also peaks at the continuum positions, but is more
dominated by the spatially extended component. The N2D+/N2H+ ratio was
estimated to be ~ 0.2 at the positions of both B1-bN and B1-bS. The derived
N2D+/N2H+ ratio is comparable to those of the prestellar cores in the late
evolutionary stage and the class 0 protostars in the early evolutionary stage.
Although B1-bN is bright in N2H+ and N2D+, this source was barely seen in
H13CO+. This implies that the depletion of carbon-bearing molecules is
significant in B1-bN. The chemical property suggests that B1-bN is in the
earlier evolutionary stage as compared to B1-bS with the H13CO+ counterpart.
The N2H+ and N2D+ lines show that the radial velocities of the two sources are
different by ~ 0.9 km s-1. However, the velocity pattern along the line through
B1-bN and B1-bS suggests that these two sources were not formed out of a single
rotating cloud. It is likely that the B1-b core consists of two velocity
components, each of which harbors a very young source.


title: Quadrature for second-order triangles in the Boundary Element Method

abstract:
  A quadrature method for second-order, curved triangular elements in the
Boundary Element Method (BEM) is presented, based on a polar coordinate
transformation, combined with elementary geometric operations. The numerical
performance of the method is presented using results from solution of the
Laplace equation on a cat's eye geometry which show an error of order
$P^{-1.6}$, where $P$ is the number of elements.


title:
Periodic Gibbs Measures for Models with Uncountable Set of Spin Values
  on a Cayley Tree

abstract:
  We consider models with nearest-neighbor interactions and with the set
$[0,1]$ of spin values, on a Cayley tree of order $k\geq 1$. We study periodic
Gibbs measures of the model with period two. For $k=1$ we show that there is no
any periodic Gibbs measure. In case $k\geq 2$ we get a sufficient condition on
Hamiltonian of the model with uncountable set of spin values under which the
model have not any periodic Gibbs measure with period two. We construct several
models which have at least two periodic Gibbs measures.


title: Phase Correction for ALMA with 183 GHz Water Vapour Radiometers

abstract:
  Fluctuating properties of the atmosphere, and in particular its water vapour
content, give rise to phase fluctuations of astronomical signals which, if
uncorrected, lead to rapid deterioration of performance of (sub)-mm
interferometers on long baselines. The Atacama Large Millimetre/submillimeter
Array (ALMA) uses a 183 GHz Water Vapour Radiometer (WVR) system to help
correct these fluctuations and provide much improved performance on long
baselines and at high frequencies. Here we describe the design of the overall
ALMA WVR system, the choice of design parameters and the data processing
strategy. We also present results of initial tests that demonstrate both the
large improvement in phase stability that can be achieved and the very low
contribution to phase noise from the WVRs. Finally, we describe briefly the
main limiting factors to the accuracy of phase correction seen in these initial
tests; namely, the degrading influence of cloud and the residual phase
fluctuations that are most likely to be due to variations in the density of the
dry component of the air


title: Triality, Periodicity and Stability of SO(8) Gauged Supergravity

abstract:
  While electromagnetic duality is a symmetry of many supergravity theories,
this is not the case for the N=8 gauged theory. It was recently shown that this
rotation leads to a one-parameter family of SO(8) supergravities. It is an open
question what the period of this parameter is. This issue is investigated in
the SO(4) invariant sectors of the theory. We classify such critical points and
find a novel branch of non-supersymmetric and unstable solutions, whose
embedding is related via triality to the two known ones. Secondly, we show that
the three branches of solutions lead to a Pi/4 periodicity of the vacuum
structure. The general interrelations between triality and periodicity are
discussed. Finally, we comment on the connection to other gauge groups as well
as the possibility to achieve (non-)perturbative stability around AdS/Mkw/dS
transitions.


title: Sequential Joint Detection and Estimation

abstract:
  We consider the problem of simultaneous detection and estimation under a
sequential framework. In particular we are interested in sequential tests that
distinguish between the null and the alternative hypothesis and every time the
decision is in favor of the alternative they provide an estimate of a random
parameter. As we demonstrate with our analysis treating the two subproblems
separately with the corresponding optimal strategies does not result in the
best possible performance. To enjoy optimality one needs to take into account
the optimum estimator during the hypothesis testing phase.


title:
Analytic form of the effective potential in the large N limit of a real
  scalar theory in four dimensions

abstract:
  We give the large N limit of the effective potential for the O(N) linear
sigma model in four dimensions in terms of the Lambert W function. The
effective potential is fully consistent with the renormalization group, and it
admits an asymptotic expansion in powers of a small positive coupling
parameter. Careful consideration of the UV cutoff present in the model
validates the physics of the large N limit.


title:
Mortality and dust expulsion in early phases of stellar clusters.
  Evidence from NIR photometry of nearby, spiral galaxies

abstract:
  It is often argued that young stellar clusters suffer a significant infant
mortality that is partly related to the expulsion of dust and gas in their
early phases caused by radiation pressure from hot stars and supernovae.
Near-infrared (J-K)-Mk diagrams of young stellar clusters in nearby spiral
galaxies show a bi-modal distribution that is consistent with a fast decline of
their intrinsic extinction at an early epoch.
  The distinct features in the color-magnitude diagrams (CMD) and the fast
change of colors for the youngest clusters allow us to place constraints on
their early evolutionary phases, including the time scale for the decreasing
extinction caused for instance by gas and dust expulsion.
  Monte Carlo simulations of cluster populations were performed using the
power-law distribution function g(M, t) ~ M^a t^gam. Integrated colors were
computed from Starburst99 models. The simulated near-infrared CMD were compared
with those observed for six grand-design, spiral galaxies using statistical
goodness-of-fit tests.
  The CMDs indicate a significant mortality of young, massive clusters with gam
= -1.4 +-0.5. High initial extinction Av = 8-11m and strong nebular emission
are required to reproduce the bi-modal color distributions of the clusters. An
extended star formation phase of longer than 5 Myr is suggested. The reduction
of the internal extinction of the clusters starts during their active star
formation and lasts for a period of 5-10 Myr.


title: Diophantine Approximation with Products of Two Primes

abstract:
  We show that for any irrational $\alpha$ and any $\tau<8/23$ there are
infinitely many $n$ which are the product of two primes for which
$$\|n\alpha\|\leq n^{-\tau}.$$ We also show that for all sufficiently large $b$
there exist 3-digit palindromes in base $b$ with precisely two prime factors.


title:
Quantum transport equations for low-dimensional multiband electronic
  systems. I

abstract:
  A systematic method of calculating the dynamical conductivity tensor in a
general multiband electronic model with strong boson-mediated electron-electron
interactions is described. The theory is based on the exact semiclassical
expression for the coupling between valence electrons and electromagnetic
fields and on the self-consistent Bethe--Salpeter equations for the
electron-hole propagators. The general diagrammatic perturbation expressions
for the intraband and interband single-particle conductivity are determined.
The relations between the intraband Bethe--Salpeter equation, the quantum
transport equation and the ordinary transport equation are briefly discussed
within the memory-function approximation. The effects of the Lorentz
dipole-dipole interactions on the dynamical conductivity of low-dimensional
$sp_\alpha$ models are described in the same approximation. Such formalism
proves useful in studies of different (pseudo)gapped states of
quasi-one-dimensional systems with the metal-to-insulator phase transitions and
can be easily extended to underdoped two-dimensional high-$T_c$
superconductors.


title: Confinement via strongly-coupled non-Abelian monopoles

abstract:
  New types of confinement phase emerge as singular SCFT's appearing as
infrared-fixed-points of N=2 supersymmetric QCD (SQCD) are perturbed by an N=1
adjoint mass term. Based on a recent remarkable work on infrared-fixed-point
SCFT of highest criticalities by Gaiotto, Seiberg and Tachikawa, we discuss
physics of certain confining systems in SU(N), USp(2N) or SO(N) gauge theories.
These show features different from a straightforward dual superconductivity
picture of confinement a' la 't Hooft and Mandelstam, which might suggest a new
venue in exploring the quark confinement mechanism in the real-world QCD.


title:
Ultra-broadband extreme-ultraviolet lensless imaging of extended complex
  structures

abstract:
  Lensless imaging is an elegant approach to high-resolution microscopy, which
is rapidly gaining popularity in applications where imaging optics are
problematic. However, current lensless imaging methods require objects to be
placed within a well-defined support structure, while the light source needs to
have a narrow, stable, and accurately known spectrum. Here we introduce a
general approach to lensless imaging without spectral bandwidth limitations or
sample requirements. We use two time-delayed coherent light pulses, and show
that scanning the pulse-to-pulse time delay allows the reconstruction of
diffraction-limited images for all spectral components in the pulse. Moreover,
an iterative phase retrieval algorithm is introduced, which uses these
spectrally resolved Fresnel diffraction patterns to obtain high-resolution
images of complex extended objects without any support requirements. We
demonstrate this two-pulse imaging method with octave-spanning visible light
sources (in both transmission and reflection geometries), and with broadband
extreme-ultraviolet radiation from a high-harmonic source. This demonstrates
that our approach enables effective use of low-flux ultra-broadband sources,
such as table-top soft-X-ray systems, for high-resolution imaging.


title:
Pulsational instability of supergiant protostars: Do they grow
  supermassive by accretion?

abstract:
  Supermassive stars (SMSs; M>10^5 Msun) and their remnant black holes are
promising progenitors for supermassive black holes (SMBHs) observed in the
early universe at z>7. It has been postulated that SMSs forms through very
rapid mass accretion onto a protostar at a high rate exceeding 0.01 Msun/yr.
According to recent studies, such rapidly accreting protostars evolve into
"supergiant protostars", i.e. protostars consisting of a bloated envelope and a
contracting core, similar to giant star. However, like massive stars as well as
giant stars, both of which are known to be pulsationally unstable, supergiant
protostars may also be also unstable to launch strong pulsation-driven
outflows. If this is the case, the stellar growth via accretion will be
hindered by the mass loss. We here study the pulsational stability of the
supergiant protostars in the mass range M<10^3 Msun through the method of the
linear perturbation analysis. We find that the supergiant protostars with M>600
Msun and very high accretion rate Mdot>1.0 Msun/yr are unstable due to the
kappa mechanism. The pulsation is excited in the He^+ ionization layer in the
envelope. Even under a conservative assumption that all the pulsation energy is
converted into the kinetic energy of the outflows, the mass-loss rate is ~10^-3
Msun/yr, which is lower than the accretion rate by more than two orders of
magnitude. We thus conclude that the supergiant protostars should grow stably
via rapid accretion at least in the mass range we studied. As long as the rapid
accretion is maintained in the later stage, protostars will become SMSs, which
eventually produce seeds for the high-z SMBHs.


title: Efficient Mesh Optimization Using the Gradient Flow of the Mean Volume

abstract:
  The signed volume function for polyhedra can be generalized to a mean volume
function for volume elements by averaging over the triangulations of the
underlying polyhedron. If we consider these up to translation and scaling, the
resulting quotient space is diffeomorphic to a sphere. The mean volume function
restricted to this sphere is a quality measure for volume elements. We show
that, the gradient ascent of this map regularizes the building blocks of hybrid
meshes consisting of tetrahedra, hexahedra, prisms, pyramids and octahedra,
that is, the optimization process converges to regular polyhedra. We show that
the (normalized) gradient flow of the mean volume yields a fast and efficient
optimization scheme for the finite element method known as the geometric
element transformation method (GETMe). Furthermore, we shed some light on the
dynamics of this method and the resulting smoothing procedure both
theoretically and experimentally.


title:
Band Structure and Optical Transitions in Atomic Layers of Hexagonal
  Gallium Chalcogenides

abstract:
  We report density-functional-theory calculations of the electronic band
structures and optical absorption spectra of two-dimensional crystals of
Ga$_2$X$_2$ (X=S, Se, and Te). Our calculations show that all three
two-dimensional materials are dynamically stable indirect-band-gap
semiconductors with a Mexican-hat dispersion of holes near the top of the
valence band. We predict the existence of Lifshitz transitions---changes in the
Fermi-surface topology of hole-doped Ga$_2$X$_2$---at hole concentrations
$n_{S}=7.96\times 10^{13}$ cm$^{-2}$, $n_{Se}=6.13\times 10^{13}$ cm$^{-2}$,
and $n_{Te}=3.54\times 10^{13}$ cm$^{-2}$.


title: The applications of the gauge transformation for the BKP hierarchy

abstract:
  In this paper, we investigated four applications of the gauge transformation
for the BKP hierarchy. Firstly, it is found that the orbit of the gauge
transformation for the constrained BKP hierarchy defines a special $(2
+1)$-dimensional Toda lattice equation structure. Then the tau function of the
BKP hierarchy generated by the gauge transformation is showed to be the
Pfaffian. And the higher Fay-like identities for the BKP hierarchy is also
obtained through the gauge transformation. At last, the compatibility between
the additional symmetry and the gauge transformation of the BKP hierarchy is
proved.


title: Solving RG equations with the Lambert W function

abstract:
  It has been known for some time that 2-loop renormalization group (RG)
equations of a dimensionless parameter can be solved in a closed form in terms
of the Lambert W function. We apply the method to a generic theory with a
Gaussian fixed point to construct RG invariant physical parameters such as a
coupling constant and a physical squared mass. As a further application, we
speculate a possible exact effective potential for the O(N) linear sigma model
in four dimensions.


title: In-flight calibration of the INTEGRAL/IBIS mask

abstract:
  Since the release of the INTEGRAL Offline Scientific Analysis (OSA) software
version 9.0, the ghost busters module has been introduced in the INTEGRAL/IBIS
imaging procedure, leading to an improvement of the sensitivity around bright
sources up to a factor of 7. This module excludes in the deconvolution process
the IBIS/ISGRI detector pixels corresponding to the projection of a bright
source through mask elements affected by some defects. These defects are most
likely associated with screws and glue fixing the IBIS mask to its support.
Following these major improvements introduced in OSA 9, a second order
correction is still required to further remove the residual noise, now at a
level of 0.2-1% of the brightest source in the field of view. In order to
improve our knowledge of the IBIS mask transparency, a calibration campaign has
been carried out during 2010-2012. We present here the analysis of these data,
together with archival observations of the Crab and Cyg X-1, that allowed us to
build a composite image of the mask defects and to investigate the origin of
the residual noise in the IBIS/ISGRI images. Thanks to this study, we were able
to point out a simple modification of the ISGRI analysis software that allows
to significantly improve the quality of the images in which bright sources are
detected at the edge of the field of view. Moreover, a refinement of the area
excluded by the ghost busters module is considered, and preliminary results
show improvements to be further tested. Finally, this study indicates further
directions to be investigated for improving the ISGRI sensitivity, such as
taking into account the thickness of the screws in the mask model or studying
the possible discrepancy between the modeled and actual mask element bridges.


title: Triangle buildings and actions of type $III_{1/q^2}$

abstract:
  We study certain group actions on triangle buildings and their boundaries and
some von Neumann algebras which can be constructed from them. In particular,
for buildings of order $q\geq 3$ certain natural actions on the boundary are
hyperfinite of type $\tqs$.


title:
Optical Kerr and Cotton-Mouton effects in atomic gases: a
  quantum-statistical study

abstract:
  Theory of the birefringence of the refractive index in atomic diamagnetic
dilute gases in the presence of static electric (optical Kerr effect) and
magnetic (Cotton-Mouton effect) fields is formulated. Quantum-statistical
expressions for the second Kerr and Cotton-Mouton virial coefficients, valid
both in the low and high temperature regimes, are derived. It is shown that
both virial coefficients can rigorously be related to the difference of the
fourth derivatives of the thermodynamic (pressure) virial coefficient with
respect to the strength of the non-resonant optical fields with parallel and
perpendicular polarizations and with respect to the external static (electric
or magnetic) field. Semiclassical expansions of the Kerr and Cotton-Mouton
coefficients are also considered, and quantum corrections up to and including
the second order are derived. Calculations of the second Kerr and Cotton-Mouton
virial coefficients of the helium-4 gas at various temperatures are reported.
The role of the quantum-mechanical effects and the convergence properties of
the semiclassical expansions are discussed. Theoretical results are compared
with the available experimental data.


title:
Blockwise and coordinatewise thresholding to combine tests of different
  natures in modern ANOVA

abstract:
  We derive new tests for fixed and random ANOVA based on a thresholded point
estimate. The pivotal quantity is the threshold that sets all the coefficients
of the null hypothesis to zero. Thresholding can be employed coordinatewise or
blockwise, or both, which leads to tests with good power properties under
alternative hypotheses that are either sparse or dense.


title: Structure of the hadron-quark mixed phase in protoneutron stars

abstract:
  We study the hadron-quark phase transition in the interior of hot
protoneutron stars, combining the Brueckner-Hartree-Fock approach for hadronic
matter with the MIT bag model or the Dyson-Schwinger model for quark matter. We
examine the structure of the mixed phase constructed according to different
prescriptions for the phase transition, and the resulting consequences for
stellar properties. We find important effects for the internal composition, but
only very small influence on the global stellar properties.


title: Rotating regular black holes

abstract:
  The formation of spacetime singularities is a quite common phenomenon in
General Relativity and it is regulated by specific theorems. It is widely
believed that spacetime singularities do not exist in Nature, but that they
represent a limitation of the classical theory. While we do not yet have any
solid theory of quantum gravity, toy models of black hole solutions without
singularities have been proposed. So far, there are only non-rotating regular
black holes in the literature. These metrics can be hardly tested by
astrophysical observations, as the black hole spin plays a fundamental role in
any astrophysical process. In this letter, we apply the Newman-Janis algorithm
to the Hayward and to the Bardeen black hole metrics. In both cases, we obtain
a family of rotating solutions. Every solution corresponds to a different
matter configuration. Each family has one solution with special properties,
which can be written in Kerr-like form in Boyer-Lindquist coordinates. These
special solutions are of Petrov type D, they are singularity free, but they
violate the weak energy condition for a non-vanishing spin and their curvature
invariants have different values at $r=0$ depending on the way one approaches
the origin. We propose a natural prescription to have rotating solutions with a
minimal violation of the weak energy condition and without the questionable
property of the curvature invariants at the origin.


title:
Constraints on models with universal extra dimensions from dilepton
  searches at the LHC

abstract:
  Models with universal extra dimensions predict that each Standard Model
particle is accompanied by a tower of Kaluza-Klein resonances. Canonical
searches for the production and cascade decays of first Kaluza-Klein modes
through missing transverse momentum signatures suffer in general from low
detection efficiencies because of the rather compressed Kaluza-Klein particle
mass spectrum. Here, instead we analyze signatures from the production of
second Kaluza-Klein states which can decay into Standard Model particles and
thus do not result in any missing transverse momentum. Such signatures provide
a strong sensitivity, and are of particular interest as they would allow for a
clear distinction between extra dimension models and other models of new
physics like supersymmetry. We constrain the production of second Kaluza-Klein
particles from recent LHC searches for dilepton resonances, and place limits on
the compactification scale to be larger than 715GeV, and on the masses of the
second Kaluza-Klein particles to be larger than 1.4TeV.


title:
Study of the accumulation layer and charge losses at the Si-SiO2
  interface in p+n-silicon strip sensors

abstract:
  Using the multi-channel Transient Current Technique the currents induced by
electron-hole pairs, produced by a focussed sub-nanosecond laser of 660 nm
wavelength close to the Si-SiO2 interface of p+n silicon strip sensors have
been measured, and the charge-collection efficiency determined.
  The laser has been operated in burst mode, with bursts typically spaced by 1
ms, each consisting of 30 pulses separated by 50 ns.
  In a previous paper it has been reported that, depending on X-ray-radiation
damage, biasing history and humidity, situations without charge losses, with
hole losses, and with electron losses have been observed.
  In this paper we show for sensors before and after irradiation by X-rays to 1
MGy (SiO2), how the charge losses change with the number of electron-hole pairs
generated by each laser pulse, and the time interval between the laser pulses.
  This allows us to estimate how many additional charges in the accumulation
layers at the Si-SiO2 interface have to be trapped to significantly change the
local electric field, as well as the time it takes that the accumulation layer
and the electric field return to the steady-state situation.
  In addition, results are presented on the change of the pulse shape caused by
the plasma effect for high charge densities deposited close to the Si-SiO2
interface.


title: Glassy Domain Wall Matter in KH2PO4 Crystal: Field-Induced Transition

abstract:
  We have investigated the domain wall (DW) dielectric response of potassium
dihydrogen phosphate (KH2PO4) crystal under 0-500V dc-bias electric field.
Activated DW-contribution onsets freezing at Tf({\omega}, V), some 27K below
the ferroelectric TC; timescale {\tau}f(T, V) exhibiting Vogel-Fulcher (VFT)
divergence. Sharply distinct low- and high-field behaviors of TC(V), DW-Tg(V),
VFT-T0(V), barrier energy Ua(V), and DW glass-fragility m(V) signify a
field-induced transition from randomly-pinned/vitreous to
clustered/glass-ceramic phases of domain wall matter. Field-hysteresis
({\epsilon}'poled > {\epsilon}'unpoled) observed at high dc-bias indicates
coexistent unclustered DW phase, quenched-in during the field-cooling. We
construct a paradigm T-E phase diagram depicting the complex glassy patterns of
domain wall matter.


title: Young rotation-powered pulsars as ultra-luminous X-ray sources

abstract:
  The aim of the present paper is to investigate a possible contribution of the
rotation-powered pulsars and pulsar wind nebulae to the population of
ultraluminous X-ray sources (ULXs). We first develop an analytical model for
the evolution of the distribution function of pulsars over the spin period and
find both the steady-state and the time-dependent solutions. Using the recent
results on the X-ray efficiency dependence on pulsar characteristic age, we
then compute the X-ray luminosity function (XLF) of rotation-powered pulsars.
In a general case it has a broken power-law shape with a high luminosity
cutoff, which depends on the distributions of the birth spin period and the
magnetic field.
  Using the observed XLF of sources in the nearby galaxies and the condition
that the pulsar XLF does not exceed that, we find the allowed region for the
parameters describing the birth period distribution. We find that the mean
pulsar period should be greater than 10-40 ms. These results are consistent
with the constraints obtained from the X-ray luminosity of core-collapse
supernovae. We estimate that the contribution of the rotation-powered pulsars
to the ULX population is at a level exceeding 3 per cent. For a wide birth
period distribution, this fraction grows with luminosity and above 10E40 erg/s
pulsars can dominate the ULX population.


title: Large-scale anomalies of the CMB in the curvaton scenario

abstract:
  We extend the curvaton scenario presented by Erickcek et al. (2008, 2009), to
explain how the even-odd multipole asymmetry of the Cosmic Microwave Background
(CMB) (also called parity asymmetry, (Kim & Naselsky 2010)) and power
anisotropies can be generated by the curvaton field, which acts as an extra
component to the spectrum of adiabatic perturbations in the inflationary epoch.
Our work provides a possible cosmic explanation to the CMB large-scale
asymmetry problems besides systematics and unknown residuals.