title:
Apsidal motion and absolute parameters for five LMC eccentric eclipsing
  binaries

abstract:
  Aims: As part of our observational projects at the La Silla Danish 1.54-meter
telescope, we aim to measure the precise times of minimum light for eccentric
eclipsing binaries in the Large Magellanic Cloud, needed for accurate
determination of apsidal motion. Many new times of minima were derived from the
photometric databases OGLE and MACHO. Several new minima were also observed.
Five early-type and eccentric-orbit eclipsing binaries: HV 982 (P = 5.34 d, e =
0.15), HV 2274 (5.73 d, 0.17), MACHO 78.6097.13 (3.11 d, 0.05), MACHO
81.8881.47 (3.88 d, 0.22), and MACHO 79.5377.76 (2.64 d, 0.06) were studied.
Methods: The O-C diagrams of the systems were analysed using all reliable
timings found in the literature, and new or improved elements of apsidal motion
were obtained. Light and radial velocity curves of MACHO 81.8881.47 and MACHO
79.5377.76 were analysed using the program PHOEBE. Results: We derived for the
first time or significantly improved the relatively short periods of apsidal
motion of 211 (12), 127 (8), 48 (13), 103 (20), and 42 (19) years,
respectively. The internal structure constants, log k2, were found to be -2.37,
-2.47, -2.17, -2.02, and -1.86 respectively, under the assumption that the
component stars rotate pseudosynchronously. The relativistic effects are weak,
up to 6% of the total apsidal motion rate. The masses for MACHO 81.8881.47
resulted in 5.51 (0.21) and 5.40 (0.19) M0, while for MACHO 79.5377.76 the
masses are 11.26 (0.35) and 11.27 (0.35) M0, respectively.


title:
Can violations of Bell's inequalities be considere as the final proof of
  quantum physics ?

abstract:
  Nowadays, it is commonly admitted that the experimental violation of Bell's
inequalities that was successfully demonstrated in the last decades by many
experimenters, are indeed the ultimate proof of quantum physics and of its
ability to describe the whole microscopic world and beyond. But the historical
and scientific story may not be envisioned so clearly: it starts with the
original paper of Einstein, Podolsky and Rosen (EPR) aiming at demonstrating
that the formalism of quantum theory is incomplete. It then goes through the
works of D. Bohm, to finally proceed to the famous John Bell's relationships
providing an experimental setup to solve the EPR paradox. In this communication
is proposed an alternative reading of this history, showing that modern
experiments based on correlations between light polarizations significantly
deviate from the original spirit of the EPR paper. It is concluded that current
experimental violations of Bell's inequalities cannot be considered as an
ultimate proof of the completeness of quantum physics models.


title:
Quantum state reconstruction of spectral field modes: homodyne and
  resonator detection schemes

abstract:
  We revisit the problem of quantum state reconstruction of light beams from
the photocurrent quantum noise. As is well-known, but often overlooked, two
longitudinal field modes contribute to each spectral component of the
photocurrent (sideband modes). We show that spectral homodyne detection is
intrinsically incapable of providing all the information needed for the full
reconstruction of the two-mode spectral quantum state. Such a limitation is
overcome by the technique of resonator detection. A detailed theoretical
description and comparison of both methods is presented, as well as an
experiment to measure the six-mode quantum state of pump-signal-idler beams of
an optical parametric oscillator above the oscillation threshold.


title:
A Super-Jupiter orbiting a late-type star: A refined analysis of
  microlensing event OGLE-2012-BLG-0406

abstract:
  We present a detailed analysis of survey and follow-up observations of
microlensing event OGLE-2012-BLG-0406 based on data obtained from 10 different
observatories. Intensive coverage of the lightcurve, especially the
perturbation part, allowed us to accurately measure the parallax effect and
lens orbital motion. Combining our measurement of the lens parallax with the
angular Einstein radius determined from finite-source effects, we estimate the
physical parameters of the lens system. We find that the event was caused by a
$2.73\pm 0.43\ M_{\rm J}$ planet orbiting a $0.44\pm 0.07\ M_{\odot}$ early
M-type star. The distance to the lens is $4.97\pm 0.29$\ kpc and the projected
separation between the host star and its planet at the time of the event is
$3.45\pm 0.26$ AU. We find that the additional coverage provided by follow-up
observations, especially during the planetary perturbation, leads to a more
accurate determination of the physical parameters of the lens.


title: Squeezing and photon counting with the cubic phase state

abstract:
  Recently, a non-Gaussian state, which is called cubic phase state has been
experimentally realized. In this work we show that, in case one has access to a
proper cubic phase state, it is possible to make photon counting experiments
and generate extremely squeezed states.


title:
Impact of adaptation currents on synchronization of coupled exponential
  integrate-and-fire neurons

abstract:
  Author summary: Synchronization of neuronal spiking in the brain is related
to cognitive functions, such as perception, attention, and memory. It is
therefore important to determine which properties of neurons influence their
collective behavior in a network and to understand how. A prominent feature of
many cortical neurons is spike frequency adaptation, which is caused by slow
transmembrane currents. We investigated how these adaptation currents affect
the synchronization tendency of coupled model neurons. Using the efficient
adaptive exponential integrate-and-fire (aEIF) model and a biophysically
detailed neuron model for validation, we found that increased adaptation
currents promote synchronization of coupled excitatory neurons at lower spike
frequencies, as long as the conduction delays between the neurons are
negligible. Inhibitory neurons on the other hand synchronize in presence of
conduction delays, with or without adaptation currents. Our results emphasize
the utility of the aEIF model for computational studies of neuronal network
dynamics. We conclude that adaptation currents provide a mechanism to generate
low frequency oscillations in local populations of excitatory neurons, while
faster rhythms seem to be caused by inhibition rather than excitation.


title:
Practical Verification of Decision-Making in Agent-Based Autonomous
  Systems

abstract:
  We present a verification methodology for analysing the decision-making
component in agent-based hybrid systems. Traditionally hybrid automata have
been used to both implement and verify such systems, but hybrid automata based
modelling, programming and verification techniques scale poorly as the
complexity of discrete decision-making increases making them unattractive in
situations where complex logical reasoning is required. In the programming of
complex systems it has, therefore, become common to separate out logical
decision-making into a separate, discrete, component. However, verification
techniques have failed to keep pace with this development. We are exploring
agent-based logical components and have developed a model checking technique
for such components which can then be composed with a separate analysis of the
continuous part of the hybrid system. Among other things this allows program
model checkers to be used to verify the actual implementation of the
decision-making in hybrid autonomous systems.


title: Giant molecular clouds: star factories of the galaxy

abstract:
  Stars are forming in our galaxy at a rate of between 1 and 4 solar masses of
stars per year. In contrast to elliptical galaxies, which are largely devoid of
star formation, star formation is still going on in spiral galaxies because of
their reservoirs of molecular gas, the fuel for new stars. The discs of spiral
galaxies are comprised not only of stars as we clearly see from Earth, but also
gas (the interstellar medium, ISM). This is where this gas accumulates into
cold, dense, molecular regions known as molecular clouds, in which new stars
are formed. Most star formation occurs in massive molecular clouds, known as
giant molecular clouds (GMCs). However, while we have a good understanding of
how individual stars form, there is less consensus on how their natal clouds of
gas accumulate, how long these clouds last, how star formation progresses over
their lifetime, and indeed how star formation has progressed over the lifetime
of the Milky Way.


title: Lie algebra of an n-Lie algebra

abstract:
  We construct the Lie algebra of an n-Lie algebra and we also define the
notion of cohomology of an n-Lie algebra.


title: Nonsoluble and non-p-soluble length of finite groups

abstract:
  Every finite group $G$ has a normal series each of whose factors either is
soluble or is a direct product of nonabelian simple groups. We define the
nonsoluble length $\lambda (G)$ as the minimum number of nonsoluble factors in
a series of this kind. Upper bounds for $\lambda (G)$ appear in the study of
various problems on finite, residually finite, and profinite groups. We prove
that $\lambda (G)$ is bounded in terms of the maximum $2$-length of soluble
subgroups of $G$, and that $\lambda (G)$ is bounded by the maximum Fitting
height of soluble subgroups. For an odd prime $p$, the non-$p$-soluble length
$\lambda _p(G)$ is introduced, and it is proved that $\lambda _p(G)$ does not
exceed the maximum $p$-length of $p$-soluble subgroups. We conjecture that for
a given prime $p$ and a given proper group variety ${\frak V}$ the
non-$p$-soluble length $\lambda _p(G)$ of finite groups $G$ whose Sylow
$p$-subgroups belong to ${\frak V}$ is bounded. In this paper we prove this
conjecture for any variety that is a product of several soluble varieties and
varieties of finite exponent.


title: Interference Alignment via Message-Passing

abstract:
  We introduce an iterative solution to the problem of interference alignment
(IA) over MIMO channels based on a message-passing formulation. We propose a
parameterization of the messages that enables the computation of IA precoders
by a min-sum algorithm over continuous variable spaces -- under this
parameterization, suitable approximations of the messages can be computed in
closed-form. We show that the iterative leakage minimization algorithm of
Cadambe et al. is a special case of our message-passing algorithm, obtained for
a particular schedule. Finally, we show that the proposed algorithm compares
favorably to iterative leakage minimization in terms of convergence speed, and
discuss a distributed implementation.


title: On Landau-Ginzburg systems, Quivers and Monodromy

abstract:
  Let $X$ be a toric Fano manifold and denote by $Crit(f_X) \subset
(\mathbb{C}^{\ast})^n$ the solution scheme of the corresponding Landau-Ginzburg
system of equations. For toric Del-Pezzo surfaces and various toric Fano
threefolds we define a map $L : Crit(f_X) \rightarrow Pic(X)$ such that
$\mathcal{E}_L(X) : = L(Crit(f_X)) \subset Pic(X)$ is a full strongly
exceptional collection of line bundles. We observe the existence of a natural
monodromy map $$ M : \pi_1(L(X) \setminus R_X,f_X) \rightarrow Aut(Crit(f_X))$$
where $L(X)$ is the space of all Laurent polynomials whose Newton polytope is
equal to the Newton polytope of $f_X$, the Landau-Ginzburg potential of $X$,
and $R_X \subset L(X)$ is the space of all elements whose corresponding
solution scheme is reduced. We show that monodromies of $Crit(f_X)$ admit
non-trivial relations to quiver representations of the exceptional collection
$\mathcal{E}_L(X)$. We refer to this property as the $M$-aligned property of
the maps $L: Crit(f_X) \rightarrow Pic(X)$. We discuss possible applications of
the existence of such $M$-aligned exceptional maps to various aspects of mirror
symmetry of toric Fano manifolds.


title: Ultrafilters on metric Spaces

abstract:
  Let $X$ be an unbounded metric space, $B(x,r) = \{y\in X: d(x,y) \leqslant
r\}$ for all $x\in X$ and $r\geqslant 0$. We endow $X$ with the discrete
topology and identify the Stone-\v{C}ech compactification $\beta X$ of $X$ with
the set of all ultrafilters on $X$. Our aim is to reveal some features of
algebra in $\beta X$ similar to the algebra in the Stone-\v{C}ech
compactification of a discrete semigroup \cite{b6}.
  We denote $X^# = \{p\in \beta X: \mbox{each}P\in p\mbox{is unbounded in}X\}$
and, for $p,q \in X^#$, write $p\parallel q$ if and only if there is $r
\geqslant 0$ such that $B(Q,r)\in p$ for each $Q\in q$, where $B(Q,
r)=\cup_{x\in Q}B(x,r)$. A subset $S\subseteq X^#$ is called invariant if $p\in
S$ and $q\parallel p$ imply $q\in S$. We characterize the minimal closed
invariant subsets of $X$, the closure of the set $K(X^#) = \bigcup\{M :
M\mbox{is a minimal closed invariant subset of}X^#\}$, and find the number of
all minimal closed invariant subsets of $X^#$.
  For a subset $Y\subseteq X$ and $p\in X^#$, we denote $\bigtriangleup_p(Y) =
Y^# \cap \{q\in X^#: p \parallel q\}$ and say that a subset $S\subseteq X^#$ is
an ultracompanion of $Y$ if $S = \bigtriangleup_p(Y)$ for some $p\in X^#$. We
characterize large, thick, prethick, small, thin and asymptotically scattered
spaces in terms of their ultracompanions.


title: Algebraic properties of robust Pad\'e approximants

abstract:
  For a recent new numerical method for computing so-called robust Pad\'e
approximants through SVD techniques, the authors gave numerical evidence that
such approximants are insensitive to perturbations in the data, and do not have
so-called spurious poles, that is, poles with a close-by zero or poles with
small residuals. A black box procedure for eliminating spurious poles would
have a major impact on the convergence theory of Pad\'e approximants since it
is known that convergence in capacity plus absence of poles in some domain D
implies locally uniform convergence in D. In the present paper we provide a
proof for forward stability (or robustness), and show absence of spurious poles
for the subclass of so-called well-conditioned Pad\'e approximants. We also
give a numerical example of some robust Pad\'e approximant which has spurious
poles, and discuss related questions. It turns out that it is not sufficient to
discuss only linear algebra properties of the underlying rectangular Toeplitz
matrix, since in our results other matrices like Sylvester matrices also occur.
These types of matrices have been used before in numerical greatest common
divisor computations.


title:
Bounds on the size of an inclusion using the translation method for
  two-dimensional complex conductivity

abstract:
  The size estimation problem in electrical impedance tomography is considered
when the conductivity is a complex number and the body is two-dimensional.
Upper and lower bounds on the volume fraction of the unknown inclusion embedded
in the body are derived in terms of two pairs of voltage and current data
measured on the boundary of the body. These bounds are derived using the
translation method. We also provide numerical examples to show that these
bounds are quite tight and stable under measurement noise.


title: An investigation of non-planar austenite-martensite interfaces

abstract:
  Motivated by experimental observations on CuAlNi single crystals, we present
a theoretical investigation of non-planar austenite-martensite interfaces. Our
analysis is based on the nonlinear elasticity model for martensitic
transformations and we show that, under suitable assumptions on the lattice
parameters, non-planar interfaces are possible, in particular for transitions
with cubic austenite.


title: Pioneers of Influence Propagation in Social Networks

abstract:
  With the growing importance of corporate viral marketing campaigns on online
social networks, the interest in studies of influence propagation through
networks is higher than ever. In a viral marketing campaign, a firm initially
targets a small set of pioneers and hopes that they would influence a sizeable
fraction of the population by diffusion of influence through the network. In
general, any marketing campaign might fail to go viral in the first try. As
such, it would be useful to have some guide to evaluate the effectiveness of
the campaign and judge whether it is worthy of further resources, and in case
the campaign has potential, how to hit upon a good pioneer who can make the
campaign go viral. In this paper, we present a diffusion model developed by
enriching the generalized random graph (a.k.a. configuration model) to provide
insight into these questions. We offer the intuition behind the results on this
model, rigorously proved in Blaszczyszyn & Gaurav(2013), and illustrate them
here by taking examples of random networks having prototypical degree
distributions - Poisson degree distribution, which is commonly used as a kind
of benchmark, and Power Law degree distribution, which is normally used to
approximate the real-world networks. On these networks, the members are assumed
to have varying attitudes towards propagating the information. We analyze three
cases, in particular - (1) Bernoulli transmissions, when a member influences
each of its friend with probability p; (2) Node percolation, when a member
influences all its friends with probability p and none with probability 1-p;
(3) Coupon-collector transmissions, when a member randomly selects one of his
friends K times with replacement. We assume that the configuration model is the
closest approximation of a large online social network, when the information
available about the network is very limited. The key insight offered by this
study from a firm's perspective is regarding how to evaluate the effectiveness
of a marketing campaign and do cost-benefit analysis by collecting relevant
statistical data from the pioneers it selects. The campaign evaluation
criterion is informed by the observation that if the parameters of the
underlying network and the campaign effectiveness are such that the campaign
can indeed reach a significant fraction of the population, then the set of good
pioneers also forms a significant fraction of the population. Therefore, in
such a case, the firms can even adopt the naive strategy of repeatedly picking
and targeting some number of pioneers at random from the population. With this
strategy, the probability of them picking a good pioneer will increase
geometrically fast with the number of tries.


title: A Conversation with Stephen E. Fienberg

abstract:
  The following conversation is based in part on a transcript of a 2009
interview funded by Pfizer Global Research-Connecticut, the American
Statistical Association and the Department of Statistics at the University of
Connecticut-Storrs as part of the "Conversations with Distinguished
Statisticians in Memory of Professor Harry O. Posten".


title:
On the area of the graph of a piecewise smooth map from the plane to the
  plane with a curve discontinuity

abstract:
  In this paper we provide an estimate from above for the value of the relaxed
area functional for a map defined on a bounded domain of the plane with values
in the plane and discontinuous on a regular simple curve with two endpoints. We
show that, under suitable assumptions, the relaxed area does not exceed the
area of the regular part of the map, with the addition of a singular term
measuring the area of a disk type solution of the Plateau's problem spanning
the two traces of the map on the jump. The result is valid also when the area
minimizing surface has self intersections. A key element in our argument is to
show the existence of what we call a semicartesian parametrization of this
surface, namely a conformal parametrization defined on a suitable parameter
space, which is the identity in the first component. To prove our result,
various tools of parametric minimal surface theory are used, as well as some
result from Morse theory.


title: Young's double slit interference pattern from a twisted beam

abstract:
  The interference pattern of a Laguerre Gaussian beam in a double slit
experiment is reported. Whereas a typical laser beam phase front is planar, a
Laguerre Gaussian beam exhibits a wave front that is twisting along the
direction of propagation. This leads to a distorted interference pattern. The
topological charge also called the order of the twisted beam can be then
readily and simply determined. More precisely, the naked eye resolution of the
distortion shift of the interference pattern directly informs about the number
of twists made as well as on the sign of the twist. These results are in very
good agreement with theoretical calculations that offer a general description
of the double slit interference with twisted beams.


title:
Theory of off-normal incidence ion sputtering of surfaces of type
  A_xB_{1-x} and a conformal map method for stochastic continuum models

abstract:
  Bradley et. al. recently provided an explanation of nanodot and defect-free
ordered ripple production from binary compounds, for normal and oblique
incidence ion sputtering respectively, by the inclusion of the effect of the
preferential sputtering of one type of atom relative to the other type on the
surfaces of binary compounds. In this paper, we propose an extended anisotropic
model of such surfaces of type AxB1-x that addresses anisotropy in the
variations of the specie-composition as well. We show that this model gives the
anisotropic Cuerno-Barabasi model as x approaches unity, and analyze the
general properties of the model. Further, the complexity of the solutions of
non-linear higher-order differential equations in general has led to the
creation of great number of highly technical and computationally intensive
numerical schemes. We introduce a simple conformal map method which allows for
a fast and accurate simulation of the dynamical evolution of ion-sputtered
surfaces based on any stochastic continuum model. An optimization algorithm for
an efficient application of the scheme is also introduced. In this scheme the
noise term has a physical meaning which allows one to go beyond the usual white
noise approximation by actually being able to assign physical parameters to it.


title: A statistical physics perspective on criticality in financial markets

abstract:
  Stock markets are complex systems exhibiting collective phenomena and
particular features such as synchronization, fluctuations distributed as
power-laws, non-random structures and similarity to neural networks. Such
specific properties suggest that markets operate at a very special point.
Financial markets are believed to be critical by analogy to physical systems
but few statistically founded evidence have been given. Through a data-based
methodology and comparison to simulations inspired by statistical physics of
complex systems, we show that the Dow Jones and indices sets are not rigorously
critical. However, financial systems are closer to the criticality in the crash
neighborhood.


title:
On the intersection of a sparse curve and a low-degree curve: A
  polynomial version of the lost theorem

abstract:
  Consider a system of two polynomial equations in two variables:
$$F(X,Y)=G(X,Y)=0$$ where $F \in \rr[X,Y]$ has degree $d \geq 1$ and $G \in
\rr[X,Y]$ has $t$ monomials. We show that the system has only $O(d^3t+d^2t^3)$
real solutions when it has a finite number of real solutions. This is the first
polynomial bound for this problem. In particular, the bounds coming from the
theory of fewnomials are exponential in $t$, and count only nondegenerate
solutions. More generally, we show that if the set of solutions is infinite, it
still has at most $O(d^3t+d^2t^3)$ connected components. By contrast, the
following question seems to be open: if $F$ and $G$ have at most $t$ monomials,
is the number of (nondegenerate) solutions polynomial in $t$? The authors'
interest for these problems was sparked by connections between lower bounds in
algebraic complexity theory and upper bounds on the number of real roots of
"sparse like" polynomials.


title: Multiphase shape optimization problems

abstract:
  This paper is devoted to the analysis of multiphase shape optimization
problems, which can formally be written as
$\min\Big\{{g}(F_1(\Omega_1),\dots,F_h(\Omega_h))+
m\vert\,\bigcup_{i=1}^h\Omega_i\vert :\ \Omega_i\subset D,\ \Omega_i\cap
\Omega_j =\emptyset\Big\},$ where $D\subset\mathcal{R}^d$ is a given bounded
open set, $\vert\Omega_i\vert$ is the Lebesgue measure of $\Omega_i$ and $m$ is
a positive constant. For a large class of such functionals, we analyse
qualitative properties of the cells $\Omega_i$ and the interaction between
them. Each cell is itself subsolution for a (single phase) shape optimization
problem, from which we deduce properties like finite perimeter, inner density,
separation by open sets, absence of triple junction points, etc.
  As main examples we consider functionals involving the eigenvalues of the
Dirichlet Laplacian of each cell, i.e. $F_i=\lambda_{k_i}$.


title:
Applications in Enumerative Combinatorics of Infinite Weighted Automata
  and Graphs

abstract:
  In this paper we studied infinite weighted automata and a general methodology
to solve a wide variety of classical lattice path counting problems in an
uniform way. This counting problems are related to Dyck paths, Motzkin paths
and some generalizations. These methodology uses weighted automata, equations
of ordinary generating functions and continued fractions. It is a variation of
the one proposed by J. Rutten.


title:
The Maxey-Riley Equation: Existence, Uniqueness and Regularity of
  Solutions

abstract:
  The Maxey--Riley equation describes the motion of an inertial (i.e.,
finite-size) spherical particle in an ambient fluid flow. The equation is a
second-order, implicit integro-differential equation with a singular kernel,
and with a forcing term that blows up at the initial time. Despite the
widespread use of the equation in applications, the basic properties of its
solutions have remained unexplored. Here we fill this gap by proving local
existence and uniqueness of weak solutions. For certain initial velocities
between the particle and the fluid, the results extend to strong solutions. We
also prove continuous differentiability of the weak and strong solutions with
respect to their initial conditions. This justifies the search for coherent
structures in inertial flows using the Cauchy--Green strain tensor.


title: M-Power Regularized Least Squares Regression

abstract:
  Regularization is used to find a solution that both fits the data and is
sufficiently smooth, and thereby is very effective for designing and refining
learning algorithms. But the influence of its exponent remains poorly
understood. In particular, it is unclear how the exponent of the reproducing
kernel Hilbert space~(RKHS) regularization term affects the accuracy and the
efficiency of kernel-based learning algorithms. Here we consider regularized
least squares regression (RLSR) with an RKHS regularization raised to the power
of m, where m is a variable real exponent. We design an efficient algorithm for
solving the associated minimization problem, we provide a theoretical analysis
of its stability, and we compare its advantage with respect to computational
complexity, speed of convergence and prediction accuracy to the classical
kernel ridge regression algorithm where the regularization exponent m is fixed
at 2. Our results show that the m-power RLSR problem can be solved efficiently,
and support the suggestion that one can use a regularization term that grows
significantly slower than the standard quadratic growth in the RKHS norm.


title: Fully Homomorphic Encryption Scheme with Symmetric Keys

abstract:
  Homomorphic encryption has largely been studied in context of public key
cryptosystems. But there are applications which inherently would require
symmetric keys. We propose a symmetric key encryption scheme with fully
homomorphic evaluation capabilities. The operations are matrix based, that is
the scheme consists of mapping the operations on integers to operations on
matrix. We also include a protocol which uses the proposed scheme for private
data processing in clouds.


title:
High Capacity Imaging and Rotationally Insensitive Object Identification
  with Correlated Orbital Angular Momentum States

abstract:
  Using no conventional measurements in position space, information extraction
rates exceeding one bit per photon are achieved by employing high-dimensional
correlated orbital angular momentum (OAM) states for object recognition. The
correlations are shown to be insensitive to axial rotation of the target
object: the information structure of an object's joint OAM coincidence spectrum
is unchanged even when the object undergoes random rotations between each
measurement. Additionally, OAM correlations alone are shown to be sufficient
for full image reconstruction of complex, off-axis objects, and novel object
symmetries are observed in the phases of OAM-object interaction transition
amplitudes. Variations in mutual information rates, due to off-axis translation
in the beam field, are studied, and it is shown that object symmetry signatures
and information rates are independent of environmental factors sufficiently far
from the beam center. The results motivate dynamic scanning applications in
contexts where symmetry and small numbers of noninvasive measurements are
desired.


title: Domain dynamics in the multiferroic phase of MnWO4

abstract:
  By using broadband linear and nonlinear dielectric spectroscopy we studied
the magnetoelectric dynamics in the chiral antiferromagnet MnWO4. In the
multiferroic phase the dielectric response is dominated by the dynamics of
domains and domain walls which is strongly dependent on the stimulating
electric field. The mean switching time reaches values in the minute range in
the middle of the multiferroic temperature regime at T=10 K but unexpectedly
decays again on approaching the lower, first-order phase boundary at T_N1=7.6K.
The switchability of the ferroelectric domains denotes a pinning-induced
threshold and can be described considering a growth-limited scenario with an
effective growth dimension of d=1.8. The rise of the effective dynamical
coercive field on cooling below the TN2 is much stronger compared to the usual
ferroelectrics and can be described by a power law E_c ~{\nu}^1/2. The latter
questions the feasibility of fast-switching devices based on this type of
material.


title:
Impurity states and cooperative magnetic order in Fe-based
  superconductors

abstract:
  We study impurity bound states and impurity-induced order in the
superconducting state of LiFeAs within a realistic five-band model based on the
band structure and impurity potentials obtained from density functional theory
(DFT). In agreement with recent experiments, we find that Co impurities are too
weak produce sub-gap bound states, whereas stronger impurities like Cu do. We
also obtain the bound state spectrum for magnetic impurities, such as Mn, and
show how spin-resolved tunnelling may determine the nature of the various
defect sites in iron pnictides, a prerequisite for using impurity bound states
as a probe of the ground state pairing symmetry. Lastly we show how impurities
pin both orbital and magnetic order, providing an explanation for a growing set
of experimental evidence for unusual magnetic phases in doped iron pnictides.


title:
Discrete Sparse Signals: Compressed Sensing by Combining OMP and the
  Sphere Decoder

abstract:
  We study the reconstruction of discrete-valued sparse signals from
underdetermined systems of linear equations. On the one hand, classical
compressed sensing (CS) is designed to deal with real-valued sparse signals. On
the other hand, algorithms known from MIMO communications, especially the
sphere decoder (SD), are capable to reconstruct discrete-valued non-sparse
signals from well- or overdefined system of linear equations. Hence, a
combination of both approaches is required. We discuss strategies to include
the knowledge of the discrete nature of the signal in the reconstruction
process. For brevity, the exposition is done for combining the orthogonal
matching pursuit (OMP) with the SD; design guidelines are derived. It is shown
that by suitably combining OMP and SD an efficient low-complexity scheme for
the detection of discrete sparse signals is obtained.


title:
$L^p$-$L^q$ estimates for Electromagnetic Helmholtz equation. Singular
  potentials

abstract:
  In space dimension $n\geq3$, we consider the electromagnetic Schr\"odinger
Hamiltonian $H=(\nabla-iA(x))^2+V$ and the corresponding Helmholtz equation
  (\nabla-iA(x))^2u+u+V(x)u=f\quad \text{in}\quad \mathbb{R}^n, where the
magnetic and electric potentials are allowed to have singularities at the
origin and decay at infinity. We extend the well known $L^p$-$L^q$ estimates
for the solution of the free Helmholtz equation to the case when the
electromagnetic hamiltonian $H$ is considered. This work extends the results
that appear in \cite{G}.


title:
Integral geometry of translation invariant functionals, I: The polytopal
  case

abstract:
  We study translative integral formulas for certain translation invariant
functionals on convex polytopes and discuss local extensions and applications
to Poisson processes and Boolean models.


title:
Wilson-loop correlators on the lattice and asymptotic behaviour of
  hadronic total cross sections

abstract:
  We show how universal, Froissart-like hadronic total cross sections can be
obtained in QCD in the functional-integral approach to soft high-energy
scattering, and we discuss indications of this behaviour obtained from lattice
simulations.


title: Remarks on the interquark potential in the presence of a minimal length

abstract:
  We calculate the lowest-order corrections to the static potential for both
Yang-Mills theory and gluodynamics in curved space-time, in the presence of a
quantum gravity induced minimal length. Our analysis is carried out within
stationary perturbation theory. As a consequence, the potential energy is the
sum of a Yukawa-like potential and a linear potential for gluodynamics in
curved space-time, leading to the confinement of static charges. Interestingly
enough, we obtain that the coefficient of the linear term ("string tension") is
ultraviolet finite. We should highlight the role played by the new quantum of
length in our analysis.


title: Fe K\alpha Line in Hard X-ray Emitting Symbiotic Stars

abstract:
  The 6.4 keV iron emission line is typically created by irradiation of the
neutral (or low ionized) iron by a hard X-ray source. Whereas the 6.7 and 7.0
keV emission lines are mainly produced by photoionization and collisional
excitation in hot plasma, the 6.4 keV fluorescence line is typically a
signature of either reflection from an accretion disk or absorption. We have
surveyed the emission using a collection of Suzaku ob- servations of hard X-ray
emitting symbiotic stars to better understand the geometry of these systems. We
find that they do not seem to have a single geometry, and that while
absorption-induced fluorescence leads to some emission in three of the hard
X-ray emitting symbiotic stars (hSSs) in our study, CH Cyg, T CrB and RT Cru
there are strong hints that significant 6.4 keV emission arises in the
accretion disk irradiated by the hard X-rays from the boundary layer between
the accretion disk and hot white dwarf in one of our sources, SS73 17. The 6.7
and 7.0 keV lines, however, are largely produced by collisional excitation in
the vicinity of the compact white dwarf.


title: Jack-Laurent symmetric functions

abstract:
  We develop the general theory of Jack-Laurent symmetric functions, which are
certain generalisations of the Jack symmetric functions, depending on an
additional parameter p_0.


title:
Nematic Metal and Antiferromagnetic Insulator on Hexagonal Kagome
  Lattice

abstract:
  Hexagonal Kagome lattice is a multiband system with a quadratic band crossing
point, in contrast with honeycomb lattice with linear band crossing point,
which has exotic correlated effect and can produce various novel quantum
states. Here we investigate the phase diagram of the fermions on the hexagonal
Kagome lattice as a function of interaction, temperature and lattice
anisotropy, by combining the cellular dynamical mean-field theory with the
continuous time quantum Monte Carlo method. For weak interaction, the quadratic
band-crossing point is broken to linear band crossing point and the system is
the semi-metal. With the increasing of the interaction, the system goes a first
order transition to antiferromagnetic Mott insulator at low temperature. Below
a critical temperature, due to the charge nematic fluctuation, a nematic metal
forms between the weak coupling semi-metal and strong correlated Mott
insulator. When the lattice anisotropy increases, the region of the nematic
metal is enlarged. Furthermore, we discuss how to detect these phases in real
experiments.


title:
Eclipse-IT 2013: Proceedings of VIII Workshop of the Italian Eclipse
  Community

abstract:
  This volume contains the extended abstracts of the contributions presented at
EclipseIT 2013, the 8th workshop of the Italian Eclipse Community, hosted by
the Computer Science Department of the University of Milan (Crema Campus) on
September 19-20, 2013. Although Eclipse was initially designed as an integrated
development environment (IDE) for object-oriented application development,
today it represents an open development platform comprised of extensible
frameworks, tools and runtimes for building, deploying and managing software.
Around Eclipse, an international live community continuously works on improving
the framework and on promoting the use of Eclipse. That happens also in Italy.
This workshop is, indeed, the eighth yearly meeting of the Italian Eclipse
Community which includes universities, public institutions and industries,
researchers and practitioners, students and professionals, all joined by the
interest in experimenting, extending, and supporting the Eclipse platform. The
special topic of this edition is the Software cooperative development for
mobile applications. Two tutorials are offered on this theme: (1) Sviluppo di
applicazioni enterprise per il mobile con IBM Jazz, Eclipse e Worklight by
Ferdinando Gorga from IBM, and (2) Uso di Eclipse per lo sviluppo cooperativo
del software, by Paolo Maresca of the University of Naples, Federico II.


title:
Actions of solvable Baumslag-Solitar groups on surfaces with
  (pseudo-)Anosov elements

abstract:
  Let $BS(1,n)= <a,b : a b a ^{-1} = b ^n>$ be the solvable Baumslag-Solitar
group, where $n \geq 2$. We study representations of $BS(1, n)$ by
homeomorphisms of closed surfaces with (pseudo-)Anosov elements. That is, we
consider a closed surface $S$, and homeomorphisms $f, h: S \to S$ such that $h
f h^{-1} = f^n$, for some $ n\geq 2$. It is known that $f$ (or some power of
$f$) must be homotopic to the identity. Suppose that $h$ is pseudo-Anosov with
stretch factor $\lambda >1$. We show that $<f,h>$ is not a faithful
representation of $BS(1, n)$ if $\lambda > n$. Moreover, we show that there are
no faithful representations of $BS(1, n)$ by torus homeomorphisms with $h$ an
Anosov map and $f$ area preserving (regardless of the value of $\lambda$).


title:
Geometric analysis on the unidirectionality of the pulmonary veins for
  atrial reentry

abstract:
  It is widely believed that the pulmonary veins (PVs) of the atrium play the
central role in the generation of atrial reentry leading to atrial
fibrillation, but its mechanism has not been analytically explained. In order
to improve the current clinical procedures for atrial reentry by understanding
its mechanism, geometrical analysis is proposed on the conditions of conduction
failure at the PVs and is validated by various computational modeling. To
achieve this, a new analytic approach is proposed by adapting the geometric
relative acceleration analysis from spacetime physics on the hypothesis that a
large relative acceleration can translate to a dramatic increase in the
curvature of the wavefront and subsequently to conduction failure. This
analytic method is applied to a simplified model of the PV to reveal the strong
dependency of the propagational direction and the magnitude of anisotropy for
conduction failure. The unidirectionality of the PVs follows directly and is
validated by computational tests in a T-shaped domain, computational
simulations for three-dimensional atrial reentry and previous in-silico reports
for atrial reentry.


title:
Distribution of the Smallest Eigenvalue in Complex and Real Correlated
  Wishart Ensembles

abstract:
  For the correlated Gaussian Wishart ensemble we compute the distribution of
the smallest eigenvalue and a related gap probability.We obtain exact results
for the complex (\beta=2) and for the real case (\beta=1). For a particular set
of empirical correlation matrices we find universality in the spectral density,
for both real and complex ensembles and all kinds of rectangularity. We
calculate the asymptotic and universal results for the gap probability and the
distribution of the smallest eigenvalue. We use the Supersymmetry method, in
particular the generalized Hubbard-Stratonovich transformation and
superbosonization.


title: Scenarios of Destruction for Large Network and Increasing Reliability

abstract:
  Damage scenarios for large networks are considered. The cascade scenario is
described by means of powers of adjacency matrix. More difficult probabilistic
variants of the large network damage are modeling by Markov chains. For
reliability augmentation of networks we add a set of random intermediate agents
with big dimensionality. It provides high reliability of all system even with
low reliability of single components. Probabilistic estimation of reliability
for reinforced network is made.


title:
A simulation study of a dual-plate in-room PET system for dose
  verification in carbon ion therapy

abstract:
  Carbon ion therapy have the ability to overcome the limitation of
convertional radiotherapy due to its most energy deposition in selective depth,
usually called Bragg peak, which results in increased biological effectiness.
During carbon ion therapy, lots positron emitters such as $^{11}$C, $^{15}$O,
$^{10}$C are generated in irradiated tissues by nuclear reactions. Immediately
after patient irradiation, PET scanners can be used to measure the spatial
distribution of positron emitters, which can track the carbon beam to the
tissue. In this study, we designed and evaluated an dual-plate in-room PET
scanner to monitor patient dose in carbon ion therapy, which is based on GATE
simulation platform. A dual-plate PET is designed to avoid interference with
the carbon beam line and with patient positioning. Its performance was compared
with that of four-head and full-ring PET scanners. The dual-plate, four-head
and full-ring PET scanners consisted of 30, 60, 60 detector modules,
respectively, with a 36 cm distance between directly opposite detector modules
for dose deposition measurements. Each detector module was consisted of a
24$\times$24 array of 2$\times2\times$18 mm$^{3}$ LYSO pixels coupled to a
Hamamatsu H8500 PMT. To esitmate the production yield of positron emitters, a
10$\times15\times$15 cm$^{3}$ cuboid PMMA phantom was irradiated with 172, 200,
250 AMeV $^{12}$C beams. 3D images of the activity distribution of the three
type scanners are produced by an iterative reconstruction algorithm. By
comparing the longitudinal profile of positron emitters, measured along the
carbon beam path, we concluded that the development of a dual-plate PET scanner
is feasible to monitor the dose distribution for carbon ion therapy.


title: Repulsive Casimir Effect with Chern insulators

abstract:
  We theoretically predict that the Casimir force in vacuum between two Chern
insulator plates can be repulsive (attractive) at long distances whenever the
sign of the Chern numbers characterizing the two plates are opposite (equal). A
unique feature of this system is that the sign of the force can be tuned simply
by turning over one of the plates or alternatively by electrostatic doping. We
calculate and take into account the full optical response of the plates and
argue that such repulsion is a general phenomena for these systems as it relies
on the quantized zero frequency Hall conductivity. We show that achieving
repulsion is possible with thin films of Cr-doped (Bi,Sb)$_2$Te$_3$, that were
recently discovered to be Chern insulators with quantized Hall conductivity.


title:
Emergent topological and half semimetallic Dirac Fermions at oxide
  interfaces

abstract:
  It is highly desirable to combine recent advances in the topological quantum
phases with technologically relevant materials. Chromium dioxide (CrO2) is a
half-metallic material, widely used in high-end data storage applications.
Using first principles calculations, we show via interfacial orbital design
that a novel class of half semi-metallic Dirac electronic phase emerges at the
interface CrO2 with TiO2 in both thin film and superlattice configurations,
with four spin-polarized Dirac points in momentum-space (k-space) band
structure. When the spin and orbital degrees of freedom are allowed to couple,
the CrO2/TiO2 superlattice becomes a Chern insulator without external fields or
additional doping. With topological gaps equivalent to 43 Kelvin and a Chern
number 2, the ensuing quantization of Hall conductance to 2e^2/h will enable
potential development of these highly industrialized oxides for applications in
topologically high fidelity data storage and energy-efficient electronic and
spintronic devices.


title:
The spectrum of kink-like oscillations of solar photospheric magnetic
  elements

abstract:
  Recently, the availability of new high-spatial and -temporal resolution
observations of the solar photosphere has allowed the study of the oscillations
in small magnetic elements. Small magnetic elements have been found to host a
rich variety of oscillations detectable as intensity, longitudinal or
transverse velocity fluctuations which have been interpreted as MHD waves.
Small magnetic elements, at or below the current spatial resolution achieved by
modern solar telescopes, are though to play a relevant role in the energy
budget of the upper layers of the Sun's atmosphere, as they are found to cover
a significant fraction of the solar photosphere. Unfortunately, the limited
temporal length and/or cadence of the data sets, or the presence of
seeing-induced effects have prevented, so far, the estimation of the power
spectra of kink-like oscillations in small magnetic elements with good
accuracy. Motivated by this, we studied kink-like oscillations in small
magnetic elements, by exploiting very long duration and high-cadence data
acquired with the Solar Optical Telescope on board the Hinode satellite. In
this work we present the results of this analysis, by studying the power
spectral density of kink-like oscillations on a statistical basis. We found
that small magnetic elements exhibit a large number of spectral features in the
range 1-12 mHz. More interestingly, most of these spectral features are not
shared among magnetic elements but represent a unique signature of each
magnetic element itself.


title: Improved Decoding Algorithms for Reed-Solomon Codes

abstract:
  In coding theory, Reed-Solomon codes are one of the most well-known and
widely used classes of error-correcting codes. In this thesis we study and
compare two major strategies known for their decoding procedure, the
Peterson-Gorenstein-Zierler (PGZ) and the Berlekamp-Massey (BM) decoder, in
order to improve existing decoding algorithms and propose faster new ones. In
particular we study a modified version of the PGZ decoder, which we will call
the fast Peterson-Gorenstein-Zierler (fPGZ) decoding algorithm. This
improvement was presented in 1997 by exploiting the Hankel structure of the
syndrome matrix. In this thesis we show that the fPGZ decoding algorithm can be
seen as a particular case of the BM one. Indeed we prove that the intermediate
outcomes obtained in the implementation of fPGZ are a subset of those of the BM
decoding algorithm. In this way, we also uncover the existing relationship
between the leading principal minors of syndrome matrix and the discrepancies
computed by the BM algorithm. Finally, thanks to the study done on the
structure of the syndrome matrix and its leading principal minors, we improve
the error value computation in both the decoding strategies studied
(specifically we prove new error value formulas for the fPGZ and the BM
decoding algorithm) and moreover we state a new iterative formulation of the
PGZ decoder well suited to a parallel implementation on integrated microchips.
Thus using techniques of linear algebra we obtain a parallel decoding algorithm
for Reed-Solomon codes with an O(e) computational time complexity, where e is
the number of errors which occurred, although a fairly large number of
elementary circuit elements is needed.


title: Towards Statistical Prioritization for Software Product Lines Testing

abstract:
  Software Product Lines (SPL) are inherently difficult to test due to the
combinatorial explosion of the number of products to consider. To reduce the
number of products to test, sampling techniques such as combinatorial
interaction testing have been proposed. They usually start from a feature model
and apply a coverage criterion (e.g. pairwise feature interaction or
dissimilarity) to generate tractable, fault-finding, lists of configurations to
be tested. Prioritization can also be used to sort/generate such lists,
optimizing coverage criteria or weights assigned to features. However, current
sampling/prioritization techniques barely take product behavior into account.
We explore how ideas of statistical testing, based on a usage model (a Markov
chain), can be used to extract configurations of interest according to the
likelihood of their executions. These executions are gathered in featured
transition systems, compact representation of SPL behavior. We discuss possible
scenarios and give a prioritization procedure illustrated on an example.


title: Weak CSR expansions and transience bounds in max-plus algebra

abstract:
  This paper aims to unify and extend existing techniques for deriving upper
bounds on the transient of max-plus matrix powers. To this aim, we introduce
the concept of weak CSR expansions: A^t=CS^tR + B^t. We observe that most of
the known bounds (implicitly) take the maximum of (i) a bound for the weak CSR
expansion to hold, which does not depend on the values of the entries of the
matrix but only on its pattern, and (ii) a bound for the CS^tR term to
dominate. To improve and analyze (i), we consider various cycle replacement
techniques and show that some of the known bounds for indices and exponents of
digraphs apply here. We also show how to make use of various parameters of
digraphs. To improve and analyze (ii), we introduce three different kinds of
weak CSR expansions (named after Nachtigall, Hartman-Arguelles, and Cycle
Threshold). As a result, we obtain a collection of bounds, in general
incomparable to one another, but better than the bounds found in the
literature.


title: Progress in the parametrisation of the Neutrino sector

abstract:
  Adding gauge singlets to the original Standard Model allows an explanation
for the observed smallness of the neutrino masses using the seesaw mechanism.
Following our plans presented in the last conference of this series we present
the results for the non-standard setting, when the number of the singlets is
smaller than the number of the SM generations.


title: Model-free control of nonlinear power converters

abstract:
  A new "model-free" control methodology is applied to a boost power converter.
The properties of the boost converter allow to evaluate the performances of the
model-free strategy in the case of switching nonlinear transfer functions,
regarding load variations. Our approach, which utilizes "intelligent" PI
controllers, does not require any converter model identification while ensuring
the stability and the robustness of the controlled system. Simulation results
show that, with a simple control structure, the proposed control method is
almost insensitive to fluctuations and large load variations.


title:
Comprehensive Bayesian Analysis of Rare (Semi)leptonic and Radiative B
  Decays

abstract:
  The available data on $|\Delta B| = |\Delta S| = 1$ decays are in good
agreement with the Standard Model when permitting subleading power corrections
of about 15% at large hadronic recoil. Constraining new-physics effects in
$\mathcal{C}_7$, $\mathcal{C}_9$, $\mathcal{C}_{10}$, the data still demand the
same size of power corrections as in the Standard Model. In the presence of
chirality-flipped operators, all but one of the power corrections reduce
substantially. The Bayes factors are in favor of the Standard Model. Using new
lattice inputs for $B\to K^*$ form factors, the evidence of models with
chirality-flipped operators increases, but does not outperform the Standard
Model. We use the data to further constrain the hadronic form factors in $B\to
K$ and $B\to K^*$ transitions.


title: Spatio-temporal variation of conversational utterances on Twitter

abstract:
  Conversations reflect the existing norms of a language. Previously, we found
that utterance lengths in English fictional conversations in books and movies
have shortened over a period of 200 years. In this work, we show that this
shortening occurs even for a brief period of 3 years (September 2009-December
2012) using 229 million utterances from Twitter. Furthermore, the subset of
geographically-tagged tweets from the United States show an inverse proportion
between utterance lengths and the state-level percentage of the Black
population. We argue that shortening of utterances can be explained by the
increasing usage of jargon including coined words.


title:
Hot Electromagnetic Outflows. III. Displaced Fireball in a Strong
  Magnetic Field

abstract:
  The evolution of a dilute electron-positron fireball is calculated in the
regime of strong magnetization and very high compactness (l ~10^3-10^8).
Heating is applied at a low effective temperature (< 25 keV), and the fireball
is allowed to expand, so that the formation of a black-body spectral
distribution is inhibited by pair annihilation. The diffusion equation for
Compton scattering is coupled to a single-temperature pair gas and an exact
(trans-relativistic) cyclo-synchrotron photon source. We find that the photon
spectrum develops a quasi-thermal peak, with a power-law slope below it that is
characteristic of gamma-ray bursts. The formation of a thermal high-frequency
spectrum is checked using the full kinetic equations at l ~ 10^3. These results
have several implications for the central engine of GRBs, and the mechanism of
energy transport. 1. Baryon rest mass carries less than ~ 10^{-5} of the energy
flux at jet breakout inside ~ 10^{12} cm from the engine, with most carried by
the magnetic field. 2. This degree of baryon purity points to the presence of
an event horizon in the engine, and neutrons play a negligible role in the
prompt emission mechanism. 3. X-ray flashes are emitted by outflows carrying
enough baryons that the photosphere is pair-depleted, which we show results in
faster thermalization. 4. The relation between observed peak frequency and
burst luminosity is bounded below by the observed Amati et al. relation if jet
Lorentz factor ~ 1/(opening angle) at breakout. 5. Stellar models are used to
demonstrate an inconsistency between the highest observed GRB energies, and a
hydrodynamic nozzle: magnetic collimation is required. 6. The magnetized pair
gas is dilute enough that high-frequency Alfven waves may become charge
starved. Finally, we suggest that limitations on magnetic reconnection from
plasma collisionality have been overestimated.


title: Dissipation in Relativistic Outflows: A Multisource Overview

abstract:
  Relativistically expanding sources of X-rays and gamma-rays cover an enormous
range of (central) compactness and Lorentz factor. The underlying physics is
discussed, with an emphasis on how the dominant dissipative mode and the
emergent spectrum depend on these parameters. Photons advected outward from
high optical depth are a potentially important source of Compton seeds. Their
characteristic energy is bounded below by ~1 MeV in pair-loaded outflows of
relatively low compactness, and remains near ~1 MeV at very high compactness
and low matter loading. This is compared with the characteristic energy of O(1)
MeV observed in the rest frame spectra of many sources, including gamma-ray
bursts, OSSE jet sources, MeV Blazars, and the intense initial 0.1 s pulse of
the March 5 event. Additional topics discussed include the feedback of pair
creation on electron heating and the formation of non-thermal spectra, their
effectiveness at shielding the dissipative zone from ambient photons, direct
Compton damping of irregularities in the outflow, the relative importance of
various soft photon sources, and the softening of the emergent spectrum that
results from heavy matter loading. The implications of this work for X-ray and
optical afterglow from GRB's are briefly considered. Direct synchrotron
emission behind the forward shock is inhibited by the extremely low energy
density of the ambient magnetic field. Mildly relativistic ejecta off axis from
the main gamma-ray emitting cone become optically thin to scattering on a
timescale of ~1 day (E/10^{52} erg)^{1/2}, and can be a direct source of
afterglow radiation.


title: Examples Concerning Abelian and Cesaro Limits

abstract:
  This note provides examples of all possible equality and strict inequality
relations between upper and lower Abelian and Cesaro limits of sequences
bounded above or below.


title:
Quantum localization of chaotic eigenstates and the level spacing
  distribution

abstract:
  The phenomenon of quantum localization in classically chaotic eigenstates is
one of the main issues in quantum chaos (or wave chaos), and thus plays an
important role in general quantum mechanics or even in general wave mechanics.
In this work we propose two different localization measures characterizing the
degree of quantum localization, and study their relation to another fundamental
aspect of quantum chaos, namely the (energy) spectral statistics. Our approach
and method is quite general, and we apply it to billiard systems. One of the
signatures of the localization of chaotic eigenstates is a fractional power-law
repulsion between the nearest energy levels in the sense that the probability
density to find successive levels on a distance $S$ goes like $\propto S^\beta$
for small $S$, where $0 \leq \beta \leq 1$, and $\beta = 1$ corresponds to
completely extended states. We show that there is a clear functional relation
between the exponent {\beta} and the two different localization measures. One
is based on the information entropy and the other one on the correlation
properties of the Husimi functions. We show that the two definitions are
surprisingly linearly equivalent. The approach is applied in the case of a
mixed-type billiard system (Robnik 1983), in which the separation of regular
and chaotic eigenstates is performed.


title: On the Bernstein-von Mises phenomenon for nonparametric Bayes procedures

abstract:
  We continue the investigation of Bernstein-von Mises theorems for
nonparametric Bayes procedures from [Ann. Statist. 41 (2013) 1999-2028]. We
introduce multiscale spaces on which nonparametric priors and posteriors are
naturally defined, and prove Bernstein-von Mises theorems for a variety of
priors in the setting of Gaussian nonparametric regression and in the i.i.d.
sampling model. From these results we deduce several applications where
posterior-based inference coincides with efficient frequentist procedures,
including Donsker- and Kolmogorov-Smirnov theorems for the random posterior
cumulative distribution functions. We also show that multiscale posterior
credible bands for the regression or density function are optimal frequentist
confidence bands.


title:
Sharp Condition for blow-up and global existence in a two species
  chemotactic Keller-Segel system in $\mathbb{R}^2$

abstract:
  For the parabolic-elliptic Keller-Segel system in R^2 it has been proved that
if the initial mass is less than 8\pi/\chi\ global solution exist and in the
case that the initial mass is larger than 8\pi/\chi\ blow-up happens. The case
of several chemotactic species introduces an additional question: What is the
analog for the critical mass obtained for the single species system? We find a
threshold curve in the case of two especies case that allows us to determine if
the system has blow-up or has a global in time solution.


title:
Phasemeter core for intersatellite laser heterodyne interferometry:
  modelling, simulations and experiments

abstract:
  Inter satellite laser interferometry is a central component of future
space-borne gravity instruments like LISA, eLISA, NGO and future geodesy
missions. The inherently small laser wavelength allows to measure distance
variations with extremely high precision by interfering a reference beam with a
measurement beam. The readout of such interferometers is often based on
tracking phasemeters, able to measure the phase of an incoming beatnote with
high precision over a wide range of frequencies. The implementation of such
phasemeters is based on all digital phase-locked loops, hosted in FPGAs. Here
we present a precise model of an all digital phase locked loop that allows to
design such a readout algorithm and we support our analysis by numerical
performance measurements and experiments with analog signals.


title: The Metallicity Dependence of the Cepheid P-L Relation in M101

abstract:
  The impact of metallicity on the Cepheid Period-Luminosity (P-L) relation is
investigated using HST ACS V and I images of M101. Variations in the
reddening-free Wesenheit parameter (W), which is employed as a proxy for
luminosity, are examined as a function of the radial distance from the center
of M101 (and thus metallicity). We determine that there is no dependence of the
slope on metallicity. However, the intercept is found to depend on metallicity
by -0.33 +/- 0.12 mag/dex and -0.71 +/- 0.17 mag/dex using 2 and 3 sigma
rejection criteria, respectively. Sigma-clipping impacts the derived
metallicity dependence, and the 2-sigma criterion applied likely mitigates
blending, particularly in the crowded inner regions of M101. A
metallicity-corrected distance modulus of 28.96 +/- 0.11 for M101 is obtained
from 619 Cepheids, a result that agrees with the recently determined SN Ia
distance. The metallicity effects described can be bypassed by working at near
and mid-infrared wavelengths (e.g., the Carnegie Hubble Program).


title:
Teaching Wireless Sensor Networks: An Holistic Approach Bridging Theory
  and Practice at the Master Level

abstract:
  Wireless Sensor Networks (WSNs) are a new technology that has received a
substantial attention from several academic research fields in the last years.
There are many applications of WSNs, including environmental monitoring,
industrial automation, intelligent transportation systems, healthcare and
wellbeing, smart energy, to mention a few. Courses have been introduced both at
the PhD and at the Master levels. However, these existing courses focus on
particular aspects of WSNs (Networking, or Signal Processing, or Embedded
Software), whereas WSNs encompass disciplines traditionally separated in
Electrical Engineering and Computer Sciences. This paper gives two original
contributions: the essential knowledge that should be brought in a WSNs course
is characterized, and a course structure with an harmonious holistic approach
is proposed. A method based on both theory and experiments is illustrated for
the design of this course, whereby the students have hands-on to implement,
understand, and develop in practice the implications of theoretical concepts.
Theory and applications are thus considered all together. Ultimately, the
objective of this paper is to design a new course, to use innovative hands-on
experiments to illustrate the theoretical concepts in the course, to show that
theoretical aspects are essential for the solution of real-life engineering
WSNs problems, and finally to create a fun and interesting teaching and
learning environments for WSNs.


title: On algebraic fusions of association schemes

abstract:
  We give a complete description of the irreducible representations of
algebraic fusions of association schemes, in terms of the irreducible
representations of a Schur cover of the corresponding group of algebraic
automorphisms.


title:
Degrees of Freedom of Generic Block-Fading MIMO Channels without A
  Priori Channel State Information

abstract:
  We studynthe high-SNR capacity of generic MIMO Rayleigh block-fading channels
in the noncoherent setting where neither transmitter nor receiver has a priori
channel state information but both are aware of the channel statistics. In
contrast to the well-established constant block-fading model, we allow the
fading to vary within each block with a temporal correlation that is "generic"
(in the sense used in the interference-alignment literature). We show that the
number of degrees of freedom of a generic MIMO Rayleigh block-fading channel
with $T$ transmit antennas and block length $N$ is given by $T(1-1/N)$ provided
that $T<N$ and the number of receive antennas is at least $T(N-1)/(N-T)$. A
comparison with the constant block-fading channel (where the fading is constant
within each block) shows that, for large block lengths, generic correlation
increases the number of degrees of freedom by a factor of up to four.


title: On QBF Proofs and Preprocessing

abstract:
  QBFs (quantified boolean formulas), which are a superset of propositional
formulas, provide a canonical representation for PSPACE problems. To overcome
the inherent complexity of QBF, significant effort has been invested in
developing QBF solvers as well as the underlying proof systems. At the same
time, formula preprocessing is crucial for the application of QBF solvers. This
paper focuses on a missing link in currently-available technology: How to
obtain a certificate (e.g. proof) for a formula that had been preprocessed
before it was given to a solver? The paper targets a suite of commonly-used
preprocessing techniques and shows how to reconstruct certificates for them. On
the negative side, the paper discusses certain limitations of the
currently-used proof systems in the light of preprocessing. The presented
techniques were implemented and evaluated in the state-of-the-art QBF
preprocessor bloqqer.


title: Photo-Seebeck effect in tetragonal PbO single crystals

abstract:
  We report the observation of photo-Seebeck effect in tetragonal PbO crystals.
The photo-induced carriers contribute to the transport phenomena, and
consequently the electrical conductivity increases and the Seebeck coefficient
decreases with increasing photon flux density. A parallel-circuit model is used
to evaluate the actual contributions of photo-excited carriers from the
measured transport data. The photo-induced carrier concentration estimated from
the Seebeck coefficient increases almost linearly with increasing photon flux
density, indicating a successful photo-doping effect on the thermoelectric
property. The mobility decreases by illumination but the reduction rate
strongly depends on the illuminated photon energy. Possible mechanisms of such
photon-energy-dependent mobility are discussed.


title:
Combining Ontologies with Correspondences and Link Relations: The E-SHIQ
  Representation Framework

abstract:
  Combining knowledge and beliefs of autonomous peers in distributed settings,
is a ma- jor challenge. In this paper we consider peers that combine ontologies
and reason jointly with their coupled knowledge. Ontologies are within the SHIQ
fragment of Description Logics. Although there are several representation
frameworks for modular Description Log- ics, each one makes crucial assumptions
concerning the subjectivity of peers' knowledge, the relation between the
domains over which ontologies are interpreted, the expressivity of the
constructors used for combining knowledge, and the way peers share their
knowledge. However in settings where autonomous peers can evolve and extend
their knowledge and beliefs independently from others, these assumptions may
not hold. In this article, we moti- vate the need for a representation
framework that allows peers to combine their knowledge in various ways,
maintaining the subjectivity of their own knowledge and beliefs, and that
reason collaboratively, constructing a tableau that is distributed among them,
jointly. The paper presents the proposed E-SHIQ representation framework, the
implementation of the E-SHIQ distributed tableau reasoner, and discusses the
efficiency of this reasoner.


title:
Algorithmes auto-stabilisants pour la construction d'arbres couvrants et
  la gestion d'entit\'es autonomes

abstract:
  In the context of large-scale networks, the consideration of faults is an
evident necessity. This document is focussing on the self-stabilizing approach
which aims at conceiving algorithms "repairing themselves" in case of transient
faults, that is of faults implying an arbitrary modification of the states of
the processes. The document focuses on two different contexts, covering the
major part of my research work these last years. The first part of the document
is dedicated to the design and analysis of self-stabilizing algorithms for
networks of processes. The second part of the document is dedicated to the
design and analysis of self-stabilizing algorithms for autonomous entities
(i.e., software agents, robots, etc.) moving in a network.


title: Thermal neutron flux measurements in STAR experimental hall

abstract:
  We report on measurements of thermal neutron fluxes at different locations in
the STAR experimental hall during pp $\sqrt s$ = 510 GeV Run 13 at RHIC. We
compared these measurements with calculations based on \textsc{PYTHIA} as
minimum bias events generator, the detailed GEANT3 simulation of the STAR
detector and the experimental hall, and using GCALOR as neutron transport code.
A good (within $\approx$ 30%) agreement was found at locations near
($\approx$1m) and very far ($\approx$10m) from the beam pipe. For intermediate
locations ($\approx$ 5m) the simulation overestimates neutron flux by a factor
of $\approx$3.


title: Koszul algebras and their syzygies

abstract:
  These are the notes of the lectures of the author at the 2013 CIME/CIRM
summer school on Combinatorial Algebraic Geometry. Koszul algebras, introduced
by Priddy, are positively graded K-algebras R whose residue field K has a
linear free resolution as an R-module. The first part of the notes is devoted
to the introduction of Koszul algebras and their characterization in terms of
Castelnuovo-Mumford regularity. In the second part we discuss recernt results
on the syzygies of Koszul algebras. Finally in the last part we discuss the
Koszul property of Veronese algebras and of algebras associated with
collections of hyperspaces.


title: The symplectic properties of the PGL(n,C)-gluing equations

abstract:
  In a previous article we studied PGL(n,C)-representations of a 3-manifold via
a generalization of Thurston's gluing equations. Neumann has proved some
symplectic properties of Thurston's gluing equations that play an important
role in recent developments of exact and perturbative Chern-Simons theory. In
this paper, we prove the symplectic properties of the PGL(n,C)-gluing equations
for all ideal triangulations of compact oriented 3-manifolds.


title: A PDE-based approach to non-dominated sorting

abstract:
  Non-dominated sorting is a fundamental combinatorial problem in
multiobjective optimization, and is equivalent to the longest chain problem in
combinatorics and random growth models for crystals in materials science. In a
previous work, we showed that non-dominated sorting has a continuum limit that
corresponds to solving a Hamilton-Jacobi equation. In this work we present and
analyze a fast numerical scheme for this Hamilton-Jacobi equation, and show how
it can be used to design a fast algorithm for approximate non-dominated
sorting.


title: The top--Higgs coupling at the LHC

abstract:
  The factorization scale dependence of the anomalous top-Higgs coupling
effects in the leading order differential cross sections and distributions of
the secondary lepton in the process of associated production of the top quark
pair and the Higgs boson at the LHC is discussed. It is also shown that the
differential cross section as a function of the rapidity of the secondary
lepton in the process is practically not sensitive to a sign of the anomalous
pseudoscalar coupling.


title:
Atomistic-to-Continuum Multiscale Modeling with Long-Range Electrostatic
  Interactions in Ionic Solids

abstract:
  We present a multiscale atomistic-to-continuum method for ionic crystals with
defects. Defects often play a central role in ionic and electronic solids, not
only to limit reliability, but more importantly to enable the functionalities
that make these materials of critical importance. Examples include solid
electrolytes that conduct current through the motion of charged point defects,
and complex oxide ferroelectrics that display multifunctionality through the
motion of domain wall defects. Therefore, it is important to understand the
structure of defects and their response to electrical and mechanical fields. A
central hurdle, however, is that interactions in ionic solids include both
short-range atomic interactions as well as long-range electrostatic
interactions. Existing atomistic-to-continuum multi-scale methods, such as the
Quasicontinuum method, are applicable only when the atomic interactions are
short-range. In addition, empirical reductions of quantum mechanics to density
functional models are unable to capture key phenomena of interest in these
materials. To address this open problem, we develop a multiscale atomistic
method to coarse-grain the long-range electrical interactions in ionic crystals
with defects. In these settings, the charge density is rapidly varying, but in
an almost-periodic manner. The key idea is to use the polarization density
field as a multiscale mediator that enables efficient coarse-graining by
exploiting the almost-periodic nature of the variation. In regions far from the
defect, where the crystal is close-to-perfect, the polarization field serves as
a proxy that enables us to avoid accounting for the details of the charge
variation. We combine this approach for long-range electrostatics with the
standard Quasicontinuum method for short-range interactions to achieve an
efficient multiscale atomistic-to-continuum method.

categories: cond-mat.mes-hall cond-mat.mtrl-sci physics.atom-ph physics.comp-ph


title: On the Range of the Attenuated Radon Transform in Strictly Convex Sets

abstract:
  We present new necessary and sufficient conditions for a function on
$\partial\Omega\times S^1$ to be in the range of the attenuated Radon transform
of a sufficiently smooth function support in the convex set
$\bar\Omega\subset\mathbb{R}^2$. The approach is based on an explicit Hilbert
transform associated with traces of the boundary of A-analytic functions in the
sense of Bukhgeim.


title: Planetary Transits with the ALMA Radio Interferometer

abstract:
  Planetary transits are commonly observed at visible wavelengths. Here we
investigate the shape of a planetary transit observed at radio wavelengths.
Solar maps of the Sun at 17 GHz are used as a proxy for the stellar eclipse by
several sizes of planets from Super-Earths to Hot Jupiters. The relative depth
at mid transit is the same as observed at visible wavelengths, but the limb
brightening of the stellar disk at 17 GHz is clearly seen in the shape of the
transit light curve. Moreover, when the planet occults an active region the
depth of the transit decreases even further, depending on the brightness of the
active region relative to the surrounding disk. For intense active region, with
50 times the brightness temperature of the surrounding disk, the decrease can
supersede the unperturbed transit depth depending on the size of the eclipsing
planet. For a Super-Earth (R_p=0.02 R_s) crossing, the decrease in intensity is
0.04%, increasing to 0.86% in the case when a strong active region is present.
On the other hand, for a hot Jupiter with R_p=0.17 R_s, the unperturbed transit
depth is 3% increasing to 4.7% when covering this strong active region. This
kind of behavior can be verified with observation of planetary transits with
the ALMA radio interferometer.


title: Phenomenology of single and double diffraction dissociation

abstract:
  Predictions of the gap-probability renormalization model for single and
double diffraction dissociation cross sections in proton-proton collisions at
the LHC are presented and compared with recent CMS measurements.


title: Notes on nonlocal projective measurements in relativistic systems

abstract:
  In quantum mechanical bipartite systems, naive extensions of von Neumann's
projective measurement to nonlocal variables can produce superluminal signals
and thus violate causality. We analyze the projective quantum nondemolition
state-verification in a two-spin system and see how the projection introduces
nonlocality without entanglement. For the ideal measurements of "R-nonlocal"
variables, we argue that causality violation can be resolved by introducing
further restrictions on the post-measurement states, which makes the
measurement "Q-nonlocal". After we generalize these ideas to quantum mechanical
harmonic oscillators, we look into the projective measurements of the particle
number of a single mode or a wave-packet of a relativistic quantum field in
Minkowski space. It turns out that the causality-violating terms in the
expectation values of the local operators, generated either by the ideal
measurement of the "R-nonlocal" variable or the quantum nondemolition
verification of a Fock state, are all suppressed by the IR and UV cutoffs of
the theory. Thus relativistic quantum field theories with such projective
measurements are effectively causal.


title:
Accelerating and decelerating cosmology from spinor and scalar fields
  non-minimally coupled with f(R) gravity

abstract:
  In this paper we investigate the accelerating and decelerating cosmological
models with non-linear spinor fields and non-minimal interaction of $f(R)$
gravity with a scalar field. We combine two different approaches to the
description of dark energy: modified gravity theory and introduction of the
additional fields. Solutions for the FRW universe with power-law scale factor
are reconstructed for the model under consideration with specific choice for
scalar and spinor potentials. It is explained the role of scalar and spinor
potentials as well as f(R) function for emergence of accelerating or
decelerating cosmology.


title:
The Central Limit Theorem for Linear Eigenvalue Statistics of the Sum of
  Independent Matrices of Rank One

abstract:
  We consider $n\times n$ random matrices $M_{n}=\sum_{\alpha =1}^{m}{\tau
_{\alpha }}\mathbf{y}_{\alpha }\otimes \mathbf{y}_{\alpha }$, where $\tau
_{\alpha }\in \mathbb{R}$, $\{\mathbf{y}_{\alpha }\}_{\alpha =1}^{m}$ are
i.i.d. isotropic random vectors of $\mathbb{R}^n$, whose components are not
necessarily independent. It was shown in arXiv:0710.1346 that if
$m,n\rightarrow \infty$, $m/n\rightarrow c\in \lbrack 0,\infty )$, the
Normalized Counting Measures of $\{\tau _{\alpha }\}_{\alpha =1}^{m}$ converge
weakly and $\{\mathbf{y}_\alpha\}_{\alpha=1}^m$ are \textit{good} (see
corresponding definition), then the Normalized Counting Measures of eigenvalues
of $M_{n}$ converge weakly in probability to a non-random limit found in
\cite{Ma-Pa:67}. In this paper we indicate a subclass of good vectors, which we
call \textit{very good} and for which the linear eigenvalue statistics of the
corresponding matrices converge in distribution to the Gaussian law, i.e., the
Central Limit Theorem is valid. An important example of good vectors, studied
in arXiv:0710.1346 are the vectors with log-concave distribution. We discuss
the conditions for them, guaranteeing the validity of the Central Limit Theorem
for linear eigenvalue statistics of corresponding matrices.


title: Dimensional reduction to hypersurface of foliation

abstract:
  When the bulk spacetime has a foliation structure, the collective dynamics of
the hypersurfaces should reveal certain aspects of the bulk physics. The
procedure of reducing the bulk to a hypersurface, called ADM reduction, was
implemented in \cite{Park:2013iqa} where the 4D Einstein-Hilbert action was
reduced along the radial reduction. In this work, reduction along the angular
directions is considered {with a main goal to firmly establish the method of
dimensional reduction to a hypersurface of foliation.} We obtain a theory on a
2D plane (the $(t,r)$-plane) and observe that novel and elaborate boundary
effects are crucial for the consistency of the reduction. The reduction leads
to a 2D interacting quantum field theory. We comment on its application to
black hole information physics.


title:
Cohomology of local systems on the moduli of principally polarized
  abelian surfaces

abstract:
  Let A_2 be the moduli stack of principally polarized abelian surfaces and V a
smooth l-adic sheaf on A_2 associated to an irreducible rational finite
dimensional representation of Sp(4). We give an explicit expression for the
cohomology of V in any degree in terms of Tate type classes and Galois
representations attached to elliptic and Siegel cusp forms. This confirms a
conjecture of Faber and van der Geer. As an application we prove a dimension
formula for vector-valued Siegel cusp forms for Sp(4,Z) of weight three, which
had been conjectured by Ibukiyama.


title: Fermions in gravity with local spin-base invariance

abstract:
  We study a formulation of Dirac fermions in curved spacetime that respects
general coordinate invariance as well as invariance under local spin-base
transformations. The natural variables for this formulation are
spacetime-dependent Dirac matrices subject to the Clifford-algebra constraint.
In particular, a coframe, i.e. vierbein field is not required. The
corresponding affine spin connection consists of a canonical part that is
completely fixed in terms of the Dirac matrices and a free part that can be
interpreted as spin torsion. A general variation of the Dirac matrices
naturally induces a spinorial Lie derivative which coincides with the known
Kosmann-Lie derivative in the absence of torsion. Using this formulation for
building a field theory of quantized gravity and matter fields, we show that it
suffices to quantize the metric and the matter fields. This observation is of
particular relevance for field theory approaches to quantum gravity, as it can
serve for a purely metric-based quantization scheme for gravity even in the
presence of fermions.


title: Global Maximizers for the Sphere Adjoint Fourier Restriction Inequality

abstract:
  We show that constant functions are global maximizers for the adjoint Fourier
restriction inequality for the sphere.


title: Optimal Regularity for The Signorini Problem and its Free Boundary

abstract:
  We will show optimal regularity for minimizers of the Signorini problem for
the Lame system. In particular if $\u=(u^1,u^2,u^3)\in W^{1,2}(B_1^+:\R^3)$
minimizes $$ J(\u)=\int_{B_1^+}|\nabla \u+\nabla^\bot \u|^2+\lambda\div(\u)^2
$$ in the convex set $$ K=\big\{\u=(u^1,u^2,u^3)\in W^{1,2}(B_1^+:\R^3);\;
u^3\ge 0 \textrm{on}\Pi, $$ $$ \u=f\in C^\infty(\partial B_1)
\textrm{on}(\partial B_1)^+ \big\}, $$ where $\lambda\ge 0$ say.
  Then $\u\in C^{1,1/2}(B_{1/2}^+)$. Moreover the free boundary, given by $$
\Gamma_\u=\partial \{x;\;u^3(x)=0,\; x_3=0\}\cap B_{1}, $$ will be a
$C^{1,\alpha}$ graph close to points where $\u$ is not degenerate.
  Similar results have been know before for scalar partial differential
equations (see for instance \cite{AC} and \cite{ACS}). The novelty of this
approach is that it does not rely on maximum principle methods and is therefore
applicable to systems of equations.


title:
Three-dimensional off-lattice Monte Carlo kinetics simulations of
  interstellar grain chemistry and ice structure

abstract:
  The first off-lattice Monte Carlo kinetics model of interstellar dust-grain
surface chemistry is presented. The positions of all surface particles are
determined explicitly, according to the local potential minima resulting from
the pair-wise interactions of contiguous atoms and molecules, rather than by a
pre-defined lattice structure. The model is capable of simulating chemical
kinetics on any arbitrary dust-grain morphology, as determined by the
user-defined positions of each individual dust-grain atom. A simple method is
devised for the determination of the most likely diffusion pathways and their
associated energy barriers for surface species. The model is applied to a
small, idealized dust grain, adopting various gas densities and using a small
chemical network. Hydrogen and oxygen atoms accrete onto the grain, to produce
H2O, H2, O2 and H2O2. The off-lattice method allows the ice structure to evolve
freely; ice mantle porosity is found to be dependent on the gas density, which
controls the accretion rate. A gas density of 2 x 10^{4} cm^{-3}, appropriate
to dark interstellar clouds, is found to produce a fairly smooth and non-porous
ice mantle. At all densities, H2 molecules formed on the grains collect within
the crevices that divide nodules of ice, and within micropores (whose extreme
inward curvature produces strong local potential minima). The larger pores
produced in the high-density models are not typically filled with H2. Direct
deposition of water molecules onto the grain indicates that amorphous ices
formed in this way may be significantly more porous than interstellar ices that
are formed by surface chemistry.


title: The Stable Concordance Genus

abstract:
  The concordance genus of a knot is the least genus of any knot in its
concordance class. Although difficult to compute, it is a useful invariant that
highlights the distinction between the three-genus and four-genus. In this
paper we define and discuss the stable concordance genus of a knot, which
describes the behavior of the concordance genus under connected sum.


title:
Maximal Cost-Bounded Reachability Probability on Continuous-Time Markov
  Decision Processes

abstract:
  In this paper, we consider multi-dimensional maximal cost-bounded
reachability probability over continuous-time Markov decision processes
(CTMDPs). Our major contributions are as follows. Firstly, we derive an
integral characterization which states that the maximal cost-bounded
reachability probability function is the least fixed point of a system of
integral equations. Secondly, we prove that the maximal cost-bounded
reachability probability can be attained by a measurable deterministic
cost-positional scheduler. Thirdly, we provide a numerical approximation
algorithm for maximal cost-bounded reachability probability. We present these
results under the setting of both early and late schedulers.


title: Tracy-Widom asymptotics for q-TASEP

abstract:
  We consider the q-TASEP that is a q-deformation of the totally asymmetric
simple exclusion process (TASEP) on Z for q in [0,1) where the jump rates
depend on the gap to the next particle. For step initial condition, we prove
that the current fluctuation of q-TASEP at time t are of order t^{1/3} and
asymptotically distributed as the GUE Tracy-Widom distribution, which confirms
the KPZ scaling theory conjecture.


title:
On the backward stability of the second barycentric formula for
  interpolation

abstract:
  We present a new stability analysis for the second barycentric formula for
interpolation, showing that this formula is backward stable when the relevant
Lebesgue constant is small.


title:
Minimizers of a class of constrained vectorial variational problems:
  Part I

abstract:
  In this paper, we prove the existence of minimizers of a class of
multi-constrained variational problems. We consider systems involving a
nonlinearity that does not satisfy compactness, monotonicity, neither symmetry
properties. Our approach hinges on the concentration-compactness approach. In
the second part, we will treat orthogonal constrained problems for another
class of integrands using density matrices method.


title: Distance energy based routing algorithm with priority handling for UWSN

abstract:
  Under Water Sensor Networks (UWSN) have different characteristics than
terrestrial sensor networks, so routing protocols developed for terrestrial
networks are not suitable for UWSN. Underwater routing is comprehended by the
underlying network architecture and design of sensor nodes. Therefore,
efficient routing protocols need to be developed for UWSNs. We present a
Routing scheme based on routing factor (Rf) which is a function of distance and
residual energy. We also define Energy Scale Value to rationalize the available
energy to take heterogeneity in energies into account. The algorithm routes a
packet from one node to another by computing Rf for each neighboring node and
selecting the node with minimum Rf as forwarding node, thereby providing an
energy balancing mechanism among a set of candidate forwarding nodes. We have
also included priority packets in our algorithm which are forwarded in a way so
as to reduce the end to end delays between the packets and at respective nodes.
Simulations of our proposed routing algorithm shows improvement in terms of
network lifetime and number of packets delivered. Our simulations show
improvement in lifetime by a factor of 2 when analyzed with Sector Based
Routing(SBR-DLP).


title: Coherent Backaction of Quantum Dot Detectors: Qubit Isospin Precession

abstract:
  A sensitive technique for the readout of the state of a qubit is based on the
measurement of the conductance through a proximal sensor quantum dot (SQD).
Here, we theoretically study the coherent backaction of such a measurement on a
coupled SQD-charge-qubit system. We derive Markovian kinetic equations for the
ensemble-averaged state of the SQD-qubit system, expressed in the coupled
dynamics of two charge-state occupations of the SQD and two qubit isospin
vectors, one for each SQD charge state. We find that aside from introducing
dissipation, the detection also renormalizes the coherent evolution of the
SQD-qubit system. Basically, if the electron on the detector has time to probe
the qubit, then it also has time to fluctuate and thereby renormalize the
system parameters. In particular, this induces torques on the qubit isospins,
similar to the spin torque generated by the spintronic exchange field in
noncollinear spin-valve structures. Secondly, we show that for a consistent
description of the detection, one must also include the renormalization effects
in the next-to-leading order in the electron tunneling rates, especially at the
point of maximal sensitivity of the detector. Although we focus on a
charge-qubit model, our findings are generic for qubit readout schemes that are
based on spin-to-charge conversion using a quantum-dot detector. Furthermore,
our study of the stationary current through the SQD, a test measurement
verifying that the qubit couples to the detector current, already reveals
various significant effects of the isospin torques on the qubit. Our kinetic
equations provide a starting point for further studies of the time evolution in
charge-based qubit readout. Finally, we provide a rigorous sum rule that
constrains such approximate descriptions of the qubit isospin dynamics and show
that it is obeyed by our kinetic equations.


title:
Temperature response of the neuronal cytoskeleton mapped via atomic
  force and fluorescence microscopy

abstract:
  Neuronal cells change their growth properties in response to external
physical stimuli such as variations in external temperature, stiffness of the
growth substrate, or topographical guidance cues. Detailed knowledge of the
mechanisms that control these biomechanical responses is necessary for
understanding the basic principles that underlie neuronal growth and
regeneration. Here, we present elasticity maps of living cortical neurons
(embryonic rat) as a function of temperature, and correlate these maps to the
locations of internal structural components of the cytoskeleton. Neurons
display a significant increase in the average elastic modulus upon a decrease
in ambient temperature from 37{\deg}C to 25{\deg}C. We demonstrate that the
dominant mechanism by which the elasticity of the neurons changes in response
to temperature is the stiffening of the actin components of the cytoskeleton
induced by myosin II. We also report a reversible shift in the location and
composition of the high-stiffness areas of the neuron cytoskeleton with
temperature. At 37{\deg}C the areas of the cell displaying high elastic modulus
overlap with the tubulin-dense regions, while at 25{\deg}C these high-stiffness
areas correspond to the actin-dense regions of the cytoskeleton. These results
demonstrate the importance of considering temperature effects when
investigating cytoskeletal dynamics in cells.


title:
Large momentum-dependence of the main dispersion "kink" in the high-Tc
  superconductor Bi2Sr2CaCu2O8+{\delta}

abstract:
  Ultrahigh resolution angle-resolved photoemission spectroscopy with
low-energy photons is used to study the detailed momentum dependence of the
well-known nodal "kink" dispersion anomaly of Bi2Sr2CaCu2O8+{\delta}. We find
that the kink's location transitions smoothly from a maximum binding energy of
about 65 meV at the node of the d-wave superconducting gap to 55 meV roughly
one-third of the way to the antinode. Meanwhile, the self-energy spectrum
corresponding to the kink dramatically sharpens and intensifies beyond a
critical point in momentum space. We discuss the possible bosonic spectrum in
energy and momentum space that can couple to the k-space dispersion of the
electronic kinks.


title: Phase Transitions Driven by QuasiParticle Interactions

abstract:
  Quasiparticles and collective effects may have seemed exotic when first
proposed in the 1930s, but their status has blossomed with their confirmation
by todays sophisticated experiment techniques. Evidence has accumulated about
the interactions of, say, magnons and rotons and with each other and also other
quasiparticles. We briefly review the conjectures of their existence necessary
to provide quantitative agreement with experiment which in the early period was
their only reason for being. Phase transitions in the Anderson model, the Kondo
effect, roton roton interactions, and highly correlated systems such as
helium4, the Quantum Hall Effect, and BEC condensates are discussed. Some
insulator and superconductor theories seem to suggest collective interactions
of several quasiparticles may be necessary to explain the behavior. We conclude
with brief discussions of the possibility of using the parameter to detect
quantum critical points and some background on bound states emerging from the
continuum. Finally, we present a summary and conclusions and also discuss
possible future directions.


title: High-frequency Donsker theorems for L\'evy measures

abstract:
  Donsker-type functional limit theorems are proved for empirical processes
arising from discretely sampled increments of a univariate L\'evy process. In
the asymptotic regime the sampling frequencies increase to infinity and the
limiting object is a Gaussian process that can be obtained from the composition
of a Brownian motion with a covariance operator determined by the L\'evy
measure. The results are applied to derive the asymptotic distribution of
natural estimators for the distribution function of the L\'evy jump measure. As
an application we deduce Kolmogorov-Smirnov type tests and confidence bands.


title:
Holomorphic functional calculus on upper triangular forms in finite von
  Neumann algebras

abstract:
  The decompositions of an element of a finite von Neumann algebra into the sum
of a normal operator plus an s.o.t.-quasinilpotent operator, obtained using the
Haagerup--Schultz hyperinvariant projections, behave well with respect to
holomorphic functional calculus.


title: Sensitivity to switching rates in stochastically switched ODEs

abstract:
  We consider a stochastic process driven by a linear ordinary differential
equation whose right-hand side switches at exponential times between a
collection of different matrices. We construct planar examples that switch
between two matrices where the individual matrices and the average of the two
matrices are all Hurwitz (all eigenvalues have strictly negative real part),
but nonetheless the process goes to infinity at large time for certain values
of the switching rate. We further construct examples in higher dimensions where
again the two individual matrices and their averages are all Hurwitz, but the
process has arbitrarily many transitions between going to zero and going to
infinity at large time as the switching rate varies. In order to construct
these examples, we first prove in general that if each of the individual
matrices is Hurwitz, then the process goes to zero at large time for
sufficiently slow switching rate and if the average matrix is Hurwitz, then the
process goes to zero at large time for sufficiently fast switching rate. We
also give simple conditions that ensure the process goes to zero at large time
for all switching rates.


title:
Brascamp-Lieb type inequalities on weighted Riemannian manifolds with
  boundary

abstract:
  It is known that by dualizing the Bochner-Lichnerowicz-Weitzenb\"{o}ck
formula, one obtains Poincar\'e-type inequalities on Riemannian manifolds
equipped with a density, which satisfy the Bakry-\'Emery Curvature-Dimension
condition (combining a lower bound on its generalized Ricci curvature and an
upper bound on its generalized dimension). When the manifold has a boundary, an
appropriate generalization of the Reilly formula may be used instead. By
systematically dualizing this formula for various combinations of boundary
conditions of the domain (convex, mean-convex) and the function (Neumann,
Dirichlet), we obtain new Brascamp-Lieb type inequalities on the manifold. All
previously known inequalities of Lichnerowicz, Brascamp-Lieb, Bobkov-Ledoux and
Veysseire are recovered, extended to the Riemannian setting and generalized
into a single unified formulation, and their appropriate versions in the
presence of a boundary are obtained. Our framework allows to encompass the
entire class of Borell's convex measures, including heavy-tailed measures, and
extends the latter class to weighted-manifolds having negative generalized
dimension.