title:
Anisotropic optical conductivity and electron-hole asymmetry in doped
  monolayer graphene in the presence of the Rashba coupling

abstract:
  In this study, the Optical conductivity of substitutionary doped graphene is
investigated in presence of the Rashba spin orbit coupling (RSOC). Calculations
have been performed within the coherent potential approximation (CPA) beyond
the Dirac cone approximation. Results of the current study demonstrate that the
optical conductivity is increased by increasing the RSOC strength. Meanwhile it
was observed that the anisotropy of the band energy results in a considerable
anisotropic optical conductivity (AOC) in monolayer graphene. The sign and
magnitude of this anisotropic conductivity was shown to be controlled by the
external field frequency. It was also shown that the Rashba interaction results
in electron-hole asymmetry in monolayer graphene.


title: K semileptonic form factor with HISQ fermions at the physical point

abstract:
  We present results for the form factor $f_+^{K \pi}(0)$, needed to extract
the CKM matrix element $|V_{us}|$ from experimental data on semileptonic $K$
decays, on the HISQ $N_f=2+1+1$ MILC configurations. The HISQ action is also
used for the valence sector. The data set used for our final result includes
three different values of the lattice spacing and data at the physical light
quark masses. We discuss the error budget and how this calculation improves on
our previous determination of $f_+^{K \pi}(0)$ on the asqtad $N_f=2+1$ MILC
configurations.


title:
Estimating restricted mean job tenures in semi-competing risk data
  compensating victims of discrimination

abstract:
  When plaintiffs prevail in a discrimination case, a major component of the
calculation of economic loss is the length of time they would have been in the
higher position had they been treated fairly during the period in which the
employer practiced discrimination. This problem is complicated by the fact that
one's eligibility for promotion is subject to termination by retirement and
both the promotion and retirement processes may be affected by discriminatory
practices. This semi-competing risk setup is decomposed into a retirement
process and a promotion process among the employees. Predictions for the
purpose of compensation are made by utilizing the expected promotion and
retirement probabilities of similarly qualified members of the nondiscriminated
group. The restricted mean durations of three periods are estimated - the time
an employee would be at the lower position, at the higher level and in
retirement. The asymptotic properties of the estimators are presented and
examined through simulation studies. The proposed restricted mean job duration
estimators are shown to be robust in the presence of an independent frailty
term. Data from the reverse discrimination case, Alexander v. Milwaukee, where
White-male lieutenants were discriminated in promotion to captain are
reanalyzed. While the appellate court upheld liability, it reversed the
original damage calculations, which heavily depended on the time a plaintiff
would have been in each position. The results obtained by the proposed method
are compared to those made at the first trial. Substantial differences in both
directions are observed.


title: Light-superconducting interference devices

abstract:
  Recently, we have proposed the half-Josephson laser (HJL): a device that
combines lasing with superconducting leads, providing a locking between the
optical phase and the superconducting phase difference between the leads. In
this work, we propose and investigate two setups derived from a superconducting
quantum interference device (SQUID), where two conventional Josephson junctions
are replaced by two HJLs. In the first setup, the HJLs share the same resonant
mode, while in the second setup two separate resonant modes of the two lasers
are coupled optically. We dub the setup `light-superconducting interference
device' (LSID).
  In both setups, we find the operating regimes similar to those of a single
HJL. Importantly, the steady lasing field is significantly affected by the
magnetic flux penetrating the SQUID loop, with respect to both amplitude and
phase. This provides opportunities to tune or even quench the lasing by varying
a small magnetic field.
  For the second setup, we find a parameter range where the evolution equation
for the laser fields supports periodic cycles. The fields are thus modulated
with the frequency of the cycle resulting in an emission spectrum consisting of
a set of discrete modes. From this spectrum, two modes dominate in the limit of
strong optical coupling. Therefore, the LSID can be also used to generate such
modulated light.


title: On singularities of lattice varieties

abstract:
  Toric varieties associated with distributive lattices arise as a fibre of a
flat degeneration of a Schubert variety in a minuscule. The singular locus of
these varieties has been studied by various authors. In this article we prove
that the number of diamonds incident on a lattice point $\a$ in a product of
chain lattices is more than or equal to the codimension of the lattice. Using
this we also show that the lattice varieties associated with product of chain
lattices is smooth.


title:
Active narrowband filtering, line narrowing and gain using ladder
  electromagnetically induced transparency in an optically thick atomic vapour

abstract:
  Electromagnetically induced transparency (EIT) resonances using the
$5\rm{S}_{1/2}\rightarrow5\rm{P}_{3/2}\rightarrow5\rm{D}_{5/2}$ ladder-system
in optically thick Rb atomic vapour are studied. We observe a strong line
narrowing effect and gain at the $5\rm{S}_{1/2}\rightarrow5\rm{P}_{3/2}$
transition wavelength due to an energy-pooling assisted frequency conversion
with characteristics similar to four-wave mixing. As a result it is possible to
observe tunable and switchable transparency resonances with amplitude close to
$100\%$ and a linewidth of 15 MHz. In addition, the large line narrowing effect
allows resolution of $^{85}$Rb $5\rm{D}_{5/2}$ hyperfine structure even in the
presence of strong power broadening.


title:
Measurements of $\mathrm{J/\psi \rightarrow e^{+}e^{-}}$ with ALICE at
  the LHC

abstract:
  The ALICE detector provides excellent capabilities to study quarkonium
production at the Large Hadron Collider (LHC). Heavy quarkonia, bound states of
charm or beauty quark anti-quark pairs such as the $\mathrm{J/\psi}$, are
expected to be produced by initial hard processes. Thus they will provide
insight into the earliest and hottest stages of AA collisions where the
formation of a Quark-Gluon Plasma (QGP) is expected. Furthermore,
high-precision data from pp collisions represent an essential baseline for the
measurement of nuclear modifications in heavy-ions and serve also as a crucial
test for several models of quarkonium hadroproduction. In addition, the study
of pA collisions allows to investigate nuclear modifications due to Cold
Nuclear Matter (CNM) effects. In ALICE, $\mathrm{J/\psi}$ were measured in pp
and Pb--Pb collisions down to $p_{\mathrm T}$ = 0 via their di-electron decay
channel in the central barrel ($|y| <$ 0.8). Results on the nuclear
modification factor ($R_{\mathrm{AA}}$) at central rapidities in Pb--Pb
collisions at $\sqrt{s_{\mathrm{NN}}} = 2.76$ TeV will be shown and their
implications discussed. A separation of the prompt and non-prompt components is
also possible down to $p_{\mathrm T}$ of the $\mathrm{J/\psi}$ of 2 GeV/$c$.


title: Subalgebras that cover or avoid chief factors of Lie algebras

abstract:
  We call a subalgebra $U$ of a Lie algebra $L$ a $CAP$-subalgebra of $L$ if
for any chief factor $H/K$ of $L$, we have $H \cap U = K \cap U$ or $H+U =
K+U$. In this paper we investigate some properties of such subalgebras and
obtain some characterizations for a finite-dimensional Lie algebra $L$ to be
solvable under the assumption that some of its maximal subalgebras or
$2$-maximal subalgebras be $CAP$-subalgebras.


title:
On the slope of hyperelliptic fibrations with positive relative
  irregularity

abstract:
  Let $f:\, S \to B$ be a locally non-trivial relatively minimal fibration of
hyperelliptic curves of genus $g\geq 2$ with relative irregularity $q_f$. We
show a sharp lower bound on the slope $\lambda_f$ of $f$. As a consequence, we
prove a conjecture of Barja and Stoppino on the lower bound of $\lambda_f$ as
an increasing function of $q_f$ in this case, and we also prove a conjecture of
Xiao on the ampleness of the direct image of the relative canonical sheaf if
$\lambda_f<4$.


title: Fermionic Projected Entangled Pair States at Finite Temperature

abstract:
  An algorithm for imaginary time evolution of a fermionic projected entangled
pair state (PEPS) with ancillas from infinite temperature down to a finite
temperature state is presented. As a benchmark application, it is applied to
spinless fermions hopping on a square lattice subject to $p$-wave pairing
interactions. With a tiny bias it allows to evolve the system across a
high-temperature continuous symmetry-breaking phase transition.

categories: cond-mat.str-el cond-mat.quant-gas cond-mat.supr-con quant-ph


title:
The Influence of Graphene Curvature on Hydrogen Adsorption: Towards
  Hydrogen Storage Devices

abstract:
  The ability of atomic hydrogen to chemisorb on graphene makes the latter a
promising material for hydrogen storage. Based on scanning tunneling microscopy
techniques, we report on site-selective adsorption of atomic hydrogen on
convexly curved regions of monolayer graphene grown on SiC(0001). This system
exhibits an intrinsic curvature owing to the interaction with the substrate. We
show that at low coverage hydrogen is found on convex areas of the graphene
lattice. No hydrogen is detected on concave regions. These findings are in
agreement with theoretical models which suggest that both binding energy and
adsorption barrier can be tuned by controlling the local curvature of the
graphene lattice. This curvature-dependence combined with the known graphene
flexibility may be exploited for storage and controlled release of hydrogen at
room temperature making it a valuable candidate for the implementation of
hydrogen-storage devices.


title: The vortex filament equation as a pseudorandom generator

abstract:
  In this paper, we consider the evolution of the so-called vortex filament
equation (VFE), \begin{equation*} \mathbf X_t = \mathbf X_s\wedge\mathbf
X_{ss}, \end{equation*} taking a planar regular polygon of $M$ sides as initial
datum. We study VFE from a completely novel point of view: that of an evolution
equation which yields a very good generator of pseudorandom numbers in a
completely natural way. This essential randomness of VFE is in agreement with
the randomness of the physical phenomena upon which it is based.


title: Separability for Weak Irreducible matrices

abstract:
  This paper is devoted to the study of the separability problem in the field
of Quantum information theory. We deal mainly with the bipartite finite
dimensional case and with two types of matrices, one of them being the PPT
matrices. We proved that many results holds for both types. If these matrices
have specific Hermitian Schmidt decompositions then the matrices are separable
in a very strong sense. We proved that both types have what we call split
decompositions.
  We defined the notion of weak irreducible matrix, based on the concept of
irreducible state defined recently. These split decomposition theorems together
with the notion of weak irreducible matrix, imply that these matrices are weak
irreducible or a sum of weak irreducible matrices of the same type. The
separability problem for these types of matrices can be reduced to the set of
weak irreducible matrices of the same type. We also provided a complete
description of weak irreducible matrices of both types.
  Using the fact that every positive semidefinite Hermitian matrix with tensor
rank 2 is separable, we found sharp inequalites providing separability for both
types.


title: Tuning of quantum interference in top-gated graphene on SiC

abstract:
  We report on quantum-interference measurements in top-gated Hall bars of
monolayer graphene epitaxially grown on the Si face of SiC, in which the
transition from negative to positive magnetoresistance was achieved varying
temperature and charge density. We perform a systematic study of the quantum
corrections to the magnetoresistance due to quantum interference of
quasiparticles and electron-electron interaction. We analyze the contribution
of the different scattering mechanisms affecting the magnetotransport in the
$-2.0 \times 10^{10}$ cm$^{-2}$ to $3.75 \times 10^{11}$ cm$^{-2}$ density
region and find a significant influence of the charge density on the
intravalley scattering time. Furthermore, we observe a modulation of the
electron-electron interaction with charge density not accounted for by present
theory. Our results clarify the role of quantum transport in SiC-based devices,
which will be relevant in the development of a graphene-based technology for
coherent electronics.


title: Equivalence classes of codimension one cut-and-project nets

abstract:
  We prove that in any totally irrational cut-and-project setup with
codimension (internal space dimension) one, it is possible to choose sections
(windows) in non-trivial ways so that the resulting sets are bounded
displacement to lattices. Our proof demonstrates that for any irrational
$\alpha$, regardless of Diophantine type, there is a collection of intervals in
$\mathbb{R}/\mathbb{Z}$ which is closed under translation, contains intervals
of arbitrarily small length, and along which the discrepancy of the sequence
$\{n\alpha\}$ is bounded above uniformly by a constant.


title:
Linear list-approximation for short programs (or the power of a few
  random bits)

abstract:
  A $c$-short program for a string $x$ is a description of $x$ of length at
most $C(x) + c$, where $C(x)$ is the Kolmogorov complexity of $x$. We show that
there exists a randomized algorithm that constructs a list of $n$ elements that
contains a $O(\log n)$-short program for $x$. We also show a polynomial-time
randomized construction that achieves the same list size for $O(\log^2
n)$-short programs. These results beat the lower bounds shown by Bauwens et al.
\cite{bmvz:c:shortlist} for deterministic constructions of such lists. We also
prove tight lower bounds for the main parameters of our result. The
constructions use only $O(\log n)$ ($O(\log^2 n)$ for the polynomial-time
result) random bits . Thus using only few random bits it is possible to do
tasks that cannot be done by any deterministic algorithm regardless of its
running time.


title:
Modeling and estimation of multi-source clustering in crime and security
  data

abstract:
  While the presence of clustering in crime and security event data is well
established, the mechanism(s) by which clustering arises is not fully
understood. Both contagion models and history independent correlation models
are applied, but not simultaneously. In an attempt to disentangle contagion
from other types of correlation, we consider a Hawkes process with background
rate driven by a log Gaussian Cox process. Our inference methodology is an
efficient Metropolis adjusted Langevin algorithm for filtering of the intensity
and estimation of the model parameters. We apply the methodology to property
and violent crime data from Chicago, terrorist attack data from Northern
Ireland and Israel, and civilian casualty data from Iraq. For each data set we
quantify the uncertainty in the levels of contagion vs. history independent
correlation.


title: Spectral curve for open strings attached to the Y=0 brane

abstract:
  The concept of spectral curve is generalized to open strings in AdS/CFT with
integrability preserving boundary conditions. Our definition is based on the
logarithms of the eigenvalues of the open monodromy matrix and makes possible
to determine all the analytic, symmetry and asymptotic properties of the
quasimomenta. We work out the details of the whole construction for the Y = 0
brane boundary condition. The quasimomenta of open circular strings are
explicitly calculated. We use the asymptotic solutions of the Y -system and the
boundary Bethe Ansatz equations to recover the spectral curve in the strong
coupling scaling limit. Using the curve the quasiclassical fluctuations of some
open string solutions are also studied.


title:
Cosmic acceleration and $f(R)$ theory: perturbed solution in a matter
  FLRW model

abstract:
  In the present paper we consider $f(R)$ gravity theories in the metric
approach and we derive the equations of motion, focusing also on the boundary
conditions. In such a way we apply the general equations to a first order
perturbation expansion of the Lagrangian. We present a model able to fit
supernovae data without introducing dark energy.


title:
Under Augustus sign: the role of Astronomy in the foundation of Augusta
  Praetoria Salassorum

abstract:
  Augusta Praetoria Salassorum, modern Aosta, was founded around 25 BC to
celebrate the victory of Augustus army on the Salassi. Aosta is a city of the
founder under many respects; for instance, one of the two twin temples of the
forum was devoted to Augustus, and a huge triumphal arc to the ruler still
welcomes the town visitors. Recently, a sculpted block has been uncovered,
still in its original position, on a corner of one of the town towers. The
block carries reliefs, such as a plough and a spade, which are clearly related
to the town foundation ritual. As a consequence, we carried out an
archaeoastronomical analysis of the original urban plan taking into account the
complex natural horizon of the Alps in which Aosta valley is nested. The
results show that the town was very likely oriented in such a way as to
pinpoint Augustus associations with the cosmic signs of renewal: the winter
solstice and the Capricorn.


title: Topology of the view complex

abstract:
  In this paper we consider a family of simplicial complexes, which we call the
view complexes. Our choice of objects of study is motivated by theoretical
distributed computing, since the view complex is a key simplicial construction
used for protocol complexes in the snapshot computational model. We show that
the view complex $\view$ can be collapsed to the well-known complex
$\chi(\Delta^n)$, called standard chromatic subdivision of a simplex, and that
$\chi(\Delta^n)$ is itself collapsible. Furthermore, we show that the collapses
can be performed simultaneously in entire orbits of the natural symmetric group
action. Our results yield a purely combinatorial and constructive understanding
of the topology of view complexes, at the same time as they enhance our
knowledge about the standard chromatic subdivision of a simplex.


title:
Exploring the Evolution of London's Street Network in the Information
  Space: a Dual Approach

abstract:
  We study the growth of London's street-network in its dual representation, as
the city has evolved over the last 224 years. The dual representation of a
planar graph is a content-based network, where each node is a set of edges of
the planar graph, and represents a transportation unit in the so-called
information space, i.e. the space where information is handled in order to
navigate through the city. First, we discuss a novel hybrid technique to
extract dual graphs from planar graphs, called the hierarchical intersection
continuity negotiation principle. Then we show that the growth of the network
can be analytically described by logistic laws and that the topological
properties of the network are governed by robust lognormal distributions
characterising the network's connectivity and small-world properties that are
consistent over time. Moreover, we find that the double-Pareto-like
distributions for the connectivity emerge for major roads and can be modelled
via a stochastic content-based network model using simple space filling
principles.


title:
Pseudo-crystals of the group 14 elements with both 5-fold central
  rotation symmetry and divisional translation symmetry

abstract:
  Crystals are the materials which can be described by uniform periodic
lattices. Traditionally, only the 1-, 2-, 3-, 4- and 6-fold rotation symmetries
are allowed in crystals because other n-fold rotation symmetries are forbidden
by the fully periodic translation symmetry. Materials containing rotation
symmetries forbidden in crystals can be optionally described as quasicrystals
with aperiodicity. The theoretical predictions and experimental discoveries of
quasicrystals have enriched the knowledge of crystallography and topology, and
expanded the capability of growing novel materials. Mathematically, one can
fill the whole space with quasi-uniform lattices through divisional
translations and arbitrary n-fold central rotations, including the 5-fold
symmetry. However, it is unknown if such pseudo-crystals with 5-fold symmetry
exist in reality. Here we propose a generalized crystal-prediction-method which
can be used to search for potential pseudo-crystals possessing both arbitrary
n-fold rotation symmetry and divisional translation symmetry. Successful
examples with 5-fold central rotation symmetry based on the group 14 elements
are discussed. We expect timely experimental explorations on such peculiar
structures, especially on the very promising clathrate phases of the group 14
elements with only slightly larger binding energies compared with the diamond
phases.


title: Approximate Bayesian Computation with composite score functions

abstract:
  Both Approximate Bayesian Computation (ABC) and composite likelihood methods
are useful for Bayesian and frequentist inference, respectively, when the
likelihood function is intractable. We propose to use composite likelihood
score functions as summary statistics in ABC in order to obtain accurate
approximations to the posterior distribution. This is motivated by the use of
the score function of the full likelihood, and extended to general unbiased
estimating functions in complex models. Moreover, we show that if the composite
score is suitably standardised, the resulting ABC procedure is invariant to
reparameterisations and automatically adjusts the curvature of the composite
likelihood, and of the corresponding posterior distribution. The method is
illustrated through examples with simulated data, and an application to
modelling of spatial extreme rainfall data is discussed.


title: A semiclassical matrix model for quantum chaotic transport

abstract:
  We propose a matrix model which embodies the semiclassical approach to the
problem of quantum transport in chaotic systems. Specifically, a matrix
integral is presented whose perturbative expansion satisfies precisely the
semiclassical diagrammatic rules for the calculation of general counting
statistics. Evaluating it exactly, we show that it agrees with corresponding
predictions from random matrix theory. This uncovers the algebraic structure
behind the equivalence between these two approaches, and opens the way for
further semiclassical calculations.


title: Energy reconstruction in the Long-Baseline Neutrino Experiment

abstract:
  The Long-Baseline Neutrino Experiment aims at measuring fundamental physical
parameters to high precision and exploring physics beyond the standard model.
Nuclear targets introduce complications towards that aim. We investigate the
uncertainties in the energy reconstruction, based on quasielastic scattering
relations, due to nuclear effects. The reconstructed event distributions as a
function of energy tend to be smeared out and shifted by several 100 MeV in
their oscillatory structure if standard event selection is used. We show that a
more restrictive experimental event selection offers the possibility to reach
the accuracy needed for a determination of the mass ordering and the
$CP$-violating phase. Quasielastic-based energy reconstruction could thus be a
viable alternative to the calorimetric reconstruction also at higher energies.


title: Weak symmetry breaking and abstract simplex paths

abstract:
  Motivated by questions in theoretical distributed computing, we develop the
combinatorial theory of abstract simplex path subdivisions. Our main
application is a short and structural proof of the theorem of Castaneda and
Rajsbaum. This theorem in turn implies the solvability of the weak symmetry
breaking task in the immediate snapshot wait-free model in the case when the
number of processes is not a power of a prime number.


title: Inhomegeneous cosmological models and fine-tuning of the initial state

abstract:
  Inhomogeneous cosmological models are often reported to suffer from a
fine-tuning problem because of the observer's location. We study if this is a
generic feature in the Lema\^{i}tre-Tolman (LT) models, by investigating if
there are models with freedom in the initial state. In these cases, the present
fine-tuned location would be evolved from a non-fine-tuned initial state and
thus vanishing the problem. In this paper, we show that this is not a generic
problem and we give the condition when the LT models do not have fine-tuned
initial state. The physical meaning of this condition, however, requires more
investigation. We investigate if this condition can be found from a special
case: homogeneous models with matter, dark, and curvature density as
parameters. We found that with any reasonable density values, these models do
not satisfy this condition and thus do not have freedom in the initial state.
We interpret this to be linked with the fine-tuning problem of the initial
state of the homogeneous models, when the early time inflation is not included
to them. We discuss of the condition in the context of non-homogeneous models.


title:
On complex-analytic $1|3$-dimensional supermanifolds associated with
  $\mathbb{CP}^1$

abstract:
  We obtain a classification up to isomorphism of complex-analytic
supermanifolds with underlying space $\mathbb{CP}^1$ of dimension $1|3$ with
retract $(k,k,k)$, where $k\in \mathbb{Z}$. More precisely, we prove that
classes of isomorphic complex-analytic supermanifolds of dimension $1|3$ with
retract $(k,k,k)$ are in one-to-one correspondence with points of the following
set: $\mathbf{Gr}_{4k-4,3} \cup \mathbf{Gr}_{4k-4,2} \cup \mathbf{Gr}_{4k-4,1}
\cup \mathbf{Gr}_{4k-4,0}$ for $k \geq 2$. For $k < 2$ all such supermanifolds
are isomorphic to their retract $(k,k,k)$.


title:
The space of paths in complex projective space with real boundary
  conditions

abstract:
  We compute the integral homology of the space of paths in $\mathbb{C}P^n$
with endpoints in $\mathbb{R}P^n$, $n \ge 1$ and its algebra structure with
respect to the Pontryagin-Chas-Sullivan product with
$\mathbb{Z}/2$-coefficients.


title:
Unfolding the fast neutron spectra of a BC501A liquid scintillation
  detector using GRAVEL method

abstract:
  Accurate knowledge of the neutron energy spectra is useful in basic research
and applications. The overall procedure of measuring and unfolding the fast
neutron energy spectra with BC501A liquid scintillation detector is described.
The recoil proton spectrum of Am-Be neutrons was obtained experimentally. With
the NRESP7 code, the response matrix of detector was simulated. Combining the
recoil proton spectrum and response matrix, the unfolding of neutron spectra
was performed by GRAVEL iterative algorithm. A MatLab program based on the
GRAVEL method was developed. The continuous neutron spectrum of Am-Be source
and monoenergetic neutron spectrum of D-T source have been unfolded
successfully and are in good agreement with their standard reference spectra.
The unfolded Am-Be spectrum are more accurate than the spectra unfolded by
artificial neural networks in recent years.


title:
Irreducible constituents of minimal degree in supercharacters of the
  finite unitriangular groups

abstract:
  Let $q$ be a prime power and $U$ the group of lower unitriangular matrices of
order $n$ for some natural number $n$. We give a lower bound for the degrees of
irreducible constituents of Andr\'{e}-Yan supercharacters and classify the
supercharacters having constituents whose degree assume this lower bound.
Moreover we show that the number of distinct irreducible characters of $U$
meeting this condition is a polynomial in $(q-1)$ with nonnegative integral
coefficients and exhibit monomial sources for those.


title: Glasgow's Stereo Image Database of Garments

abstract:
  To provide insight into cloth perception and manipulation with an active
binocular robotic vision system, we compiled a database of 80 stereo-pair
colour images with corresponding horizontal and vertical disparity maps and
mask annotations, for 3D garment point cloud rendering has been created and
released. The stereo-image garment database is part of research conducted under
the EU-FP7 Clothes Perception and Manipulation (CloPeMa) project and belongs to
a wider database collection released through CloPeMa (www.clopema.eu). This
database is based on 16 different off-the-shelve garments. Each garment has
been imaged in five different pose configurations on the project's binocular
robot head. A full copy of the database is made available for scientific
research only at https://sites.google.com/site/ugstereodatabase/.


title: Spilling from a cognac glass

abstract:
  In the paper we study the shape of the fundamental sloshing mode of a liquid
in a container. Our approach is based on a mathematical model which is an
appropriate Steklov eigenvalue problem. We present numerical results, a
physical experiment, photos of a surface of oscillating liquid and also
rigorous mathematical results. We describe the relation of the above problem
with the celebrated hot spots conjecture.


title: Tunneling current between graphene layers

abstract:
  The physical model that allows to calculate the values of the tunneling
current be-tween graphene layers is proposed. The tunneling current according
to the pro-posed model is proportional to the area of tunneling transition. The
calculated value of tunneling conductivity is in qualitative agreement with
experimental data.


title: List decoding - random coding exponents and expurgated exponents

abstract:
  Some new results are derived concerning random coding error exponents and
expurgated exponents for list decoding with a deterministic list size $L$. Two
asymptotic regimes are considered, the fixed list-size regime, where $L$ is
fixed independently of the block length $n$, and the exponential list-size,
where $L$ grows exponentially with $n$. We first derive a general upper bound
on the list-decoding average error probability, which is suitable for both
regimes. This bound leads to more specific bounds in the two regimes. In the
fixed list-size regime, the bound is related to known bounds and we establish
its exponential tightness. In the exponential list-size regime, we establish
the achievability of the well known sphere packing lower bound. Relations to
guessing exponents are also provided. An immediate byproduct of our analysis in
both regimes is the universality of the maximum mutual information (MMI) list
decoder in the error exponent sense. Finally, we consider expurgated bounds at
low rates, both using Gallager's approach and the Csisz\'ar-K\"orner-Marton
approach, which is, in general better (at least for $L=1$). The latter
expurgated bound, which involves the notion of {\it multi-information}, is also
modified to apply to continuous alphabet channels, and in particular, to the
Gaussian memoryless channel, where the expression of the expurgated bound
becomes quite explicit.


title:
Critical behavior of Born-Infeld AdS black holes in the extended phase
  space thermodynamics

abstract:
  We study the thermodynamics of $D$-dimensional Born-Infeld AdS black holes in
the extended phase space. We find that the usual small-large black hole phase
transition, which exhibits analogy with the Van de Waals liquid-gas system
holds in all dimensions greater than three. However, different from the
four-dimensional case, in the system of higher dimensional Born-Infeld AdS
black holes there is no reentrant phase transition. For the three-dimensional
Born-Infeld AS black hole, there does not exist critical phenomena.


title:
Extended Parrondo's Game and Brownian Ratchets: Strong and Weak Parrondo
  Effect

abstract:
  Inspired by the flashing ratchet, Parrondo's game presents an apparently
paradoxical situation. Parrondo's game consists of two individual games, game A
and game B. Game A is a slightly losing coin-tossing game. Game B has two
coins, with an integer parameter $M$. If the current cumulative capital (in
discrete unit) is a multiple of $M$, an unfavorable coin $p_b$ is used,
otherwise a favorable $p_g$ coin is used. Paradoxically, combination of game A
and game B could lead to a winning game, which is the Parrondo effect. We
extend the original Parrondo's game to include the possibility of $M$ being
either $M_1$ or $M_2$. Also, we distinguish between strong Parrondo effect,
i.e. two losing games combine to form a winning game, and weak Parrondo effect,
i.e. two games combine to form a better-performing game. We find that when
$M_2$ is not a multiple of $M_1$, the combination of $B(M_1)$ and $B(M_2)$ has
strong and weak Parrondo effect for some subsets in the parameter space
$(p_b,p_g)$, while there is neither strong nor weak effect when $M_2$ is a
multiple of $M_1$. Furthermore, when $M_2$ is not a multiple of $M_1$,
stochastic mixture of game A may cancel the strong and weak Parrondo effect.
Following a discretization scheme in the literature of Parrondo's game, we
establish a link between our extended Parrondo's game with the analysis of
discrete Brownian ratchet. We find a relation between the Parrondo effect of
our extended model to the macroscopic bias in a discrete ratchet. The slope of
a ratchet potential can be mapped to the fair game condition in the extended
model, so that under some conditions, the macroscopic bias in a discrete
ratchet can provide a good predictor for the game performance of the extended
model. On the other hand, our extended model suggests a design of a ratchet in
which the potential is a mixture of two periodic potentials.


title: Stability of Monge-Amp\`ere energy classes

abstract:
  We show that the non pluripolar product of positive currents is a
bimeromorphic invariant. Under some natural assumptions, we show that the
(weighted) energy associated to big cohomology classes are also bimeromorphic
invariants. We compare the weighted energy functionals of currents with respect
to different cohomology classes and establish quantitative estimates between
big capacities.


title: Spectral and Energy Efficiency Trade-Offs in Cellular Networks

abstract:
  This paper presents a simple and effective method to study the spectral and
energy efficiency (SE-EE) trade-off in cellular networks, an issue that has
attracted significant recent interest in the wireless community. The proposed
theoretical framework is based on an optimal radio resource allocation of
transmit power and bandwidth for the downlink direction, applicable for an
orthogonal cellular network. The analysis is initially focused on a single cell
scenario, for which in addition to the solution of the main SE-EE optimization
problem, it is proved that a traffic repartition scheme can also be adopted as
a way to simplify this approach. By exploiting this interesting result along
with properties of stochastic geometry, this work is extended to a more
challenging multi-cell environment, where interference is shown to play an
essential role and for this reason several interference reduction techniques
are investigated. Special attention is also given to the case of low signal to
noise ratio (SNR) and a way to evaluate the upper bound on EE in this regime is
provided. This methodology leads to tractable analytical results under certain
common channel properties, and thus allows the study of various models without
the need for demanding system-level simulations.


title: Almost complete intersections and Stanley's conjecture

abstract:
  Let $K$ be a field and $I$ a monomial ideal of the polynomial ring
$S=K[x_1,\ldots, x_n]$. We show that if either: 1) $I$ is almost complete
intersection, 2) $I$ can be generated by less than four monomials; or 3) $I$ is
the Stanley-Reisner ideal of a locally complete intersection simplicial complex
on $[n]$, then Stanley's conjecture holds for $S/I$.


title:
Critical slowing down and the gradient flow coupling in the
  Schr\"odinger functional

abstract:
  We study the sensitivity of the gradient flow coupling to sectors of
different topological charge and its implications in practical situations.
Furthermore, we investigate an alternative definition of the running coupling
that is expected to be less sensitive to the problems of the HMC algorithm to
efficiently sample all topological sectors.


title: V+jets Background and Systematic Uncertainties in Top Quark Analyses

abstract:
  Vector boson production in association with jets is an important process to
test perturbative quantum chromodynamics and also a background process in top
quark analyses. Measurements on vector boson production in association with
light and heavy flavour jets are presented, performed by the D0 and CDF
collaborations at the Tevatron as well as the ATLAS and CMS experiments at LHC.
Techniques applied in top quark analyses to estimate the vector boson+jets
background are also discussed.


title:
Current-driven flow instabilities in large-scale liquid metal batteries,
  and how to tame them

abstract:
  The use of liquid metal batteries is considered as one promising option for
electric grid stabilisation. While large versions of such batteries are
preferred in view of the economies of scale, they are susceptible to various
magnetohydrodynamic instabilities which imply a risk of short-circuiting the
battery due to the triggered fluid flow. Here we focus on the current driven
Tayler instability and give critical electrical currents for its onset as well
as numerical estimates for the appearing flow structures and speeds. Scaling
laws for different materials, battery sizes and geometries are found. We
further discuss and compare various means for preventing the instability.


title: Schemas for Unordered XML on a DIME

abstract:
  We investigate schema languages for unordered XML having no relative order
among siblings. First, we propose unordered regular expressions (UREs),
essentially regular expressions with unordered concatenation instead of
standard concatenation, that define languages of unordered words to model the
allowed content of a node (i.e., collections of the labels of children).
However, unrestricted UREs are computationally too expensive as we show the
intractability of two fundamental decision problems for UREs: membership of an
unordered word to the language of a URE and containment of two UREs.
Consequently, we propose a practical and tractable restriction of UREs,
disjunctive interval multiplicity expressions (DIMEs).
  Next, we employ DIMEs to define languages of unordered trees and propose two
schema languages: disjunctive interval multiplicity schema (DIMS), and its
restriction, disjunction-free interval multiplicity schema (IMS). We study the
complexity of the following static analysis problems: schema satisfiability,
membership of a tree to the language of a schema, schema containment, as well
as twig query satisfiability, implication, and containment in the presence of
schema. Finally, we study the expressive power of the proposed schema languages
and compare them with yardstick languages of unordered trees (FO, MSO, and
Presburger constraints) and DTDs under commutative closure. Our results show
that the proposed schema languages are capable of expressing many practical
languages of unordered trees and enjoy desirable computational properties.


title: Heavy quark spin selection rules in S-wave meson-antimeson states

abstract:
  By studying the spin structure of an S-wave meson-antimeson system in the
heavy quark limit, we find two selection rules for the $c\bar{c}$ spin
$J_{c\bar{c}}$ being only 1: (a) $J=min(J_\ell)-1$ or $J=max(J_\ell)+1$; (b)
$J^C=1^+,2^-,3^+,\cdots$ if the two mesons are different but belong to the same
doublet. Here $J_\ell$ is the total angular momentum of the light degree of
freedom. The rules may constrain decay channels of a meson-antimeson molecule
or resonance. For the recently observed $Z_c(3900)$ state, it in principle can
decay into $J_{c\bar{c}}=0$ charmonium channels if it is a $D\bar{D}^*$
molecule or resonance. The non-observation of $h_c\pi$ decay might imply that
this state is a tetraquark.


title: Spin pumping through quantum dots

abstract:
  We propose schemes for generating spin currents into a semiconductor by
adiabatic or non-adiabatic pumping of electrons through interacting quantum
dots. The appeal of such schemes lies in the possibility to tune the pumping
characteristics via gate voltages that control the properties of the quantum
dot. The calculations are based on a systematic perturbation expansion in the
tunnel-coupling strength and the pumping frequency, expressed within a
diagrammatic real-time technique. Special focus is put on the possibility of
pure spin pumping, i.e., of pumping spin currents without charge currents.


title:
Particle Production in the Color Class Condensate: from electron-proton
  DIS to proton-nucleus collisions

abstract:
  We study single inclusive hadron production in proton-proton and
proton-nucleus collisions in the CGC framework. The parameters in the
calculation are obtained by fitting electron-proton deep inelastic scattering
data. The obtained dipole-proton amplitude is generalized to dipole-nucleus
scattering without any additional nuclear parameters other than the Woods-Saxon
distribution. We show that it is possible to use an initial condition without
an anomalous dimension and still obtain a good description of the HERA
inclusive cross section and LHC single particle production measurements. We
argue that one must consistently use the proton transverse area as measured by
a high virtuality probe in DIS also for the single inclusive cross section in
proton-proton and proton-nucleus collisions, and obtain a nuclear modification
factor $R_{pA}$ that at midrapidity approaches unity at large momenta and at
all energies.


title:
On exponential stability for stochastic differential equations disturbed
  by G-Brownian motion

abstract:
  We first introduce the calculus of Peng's G-Brownian motion on a sublinear
expectation space $(\Omega, {\cal H}, \hat{\mathbb{E}})$. Then we investigate
the exponential stability of paths for a class of stochastic differential
equations disturbed by a G-Brownian motion in the sense of quasi surely (q.s.).
The analyses consist in G-Lyapunov function and some special inequalities.
Various sufficient conditions are obtained to ensure the stability of strong
solutions. In particular, by means of our results we generalize the one in the
classical stochastic differential equations. Finally, an illustrative example
is given.


title:
Observational constraints to a phenomenological $f\left( R,\nabla
  R\right) $-model

abstract:
  This paper analyses the cosmological consequences of a modified theory of
gravity whose action integral is built from a linear combination of the Ricci
scalar $R$ and a quadratic term in the covariant derivative of $R$. The
resulting Friedmann equations are of the fifth-order in the Hubble function.
These equations are solved numerically for a flat space section geometry and
pressureless matter. The cosmological parameters of the higher-order model are
fit using SN Ia data and X-ray gas mass fraction in galaxy clusters. The
best-fit present-day $t_{0}$ values for the deceleration parameter, jerk and
snap are given. The coupling constant $\beta$\ of the model is not univocally
determined by the data fit, but partially constrained by it. Density parameter
$\Omega_{m0}$ is also determined and shows weak correlation with the other
parameters. The model allows for two possible future scenarios: there may be
either a premature Big Rip or a Rebouncing event depending on the set of values
in the space of parameters. The analysis towards the past performed with the
best-fit parameters shows that the model is not able to accommodate a
matter-dominated stage required to the formation of structure.


title:
Improving CASA Runtime Performance by Exploiting Basic Feature Model
  Analysis

abstract:
  In Software Product Line Engineering (SPLE) families of systems are designed,
rather than developing the individual systems independently. Combinatorial
Interaction Testing has proven to be effective for testing in the context of
SPLE, where a representative subset of products is chosen for testing in place
of the complete family. Such a subset of products can be determined by
computing a so called t-wise Covering Array (tCA), whose computation is
NP-complete. Recently, reduction rules that exploit basic feature model
analysis have been proposed that reduce the number of elements that need to be
considered during the computation of tCAs for Software Product Lines (SPLs). We
applied these rules to CASA, a simulated annealing algorithm for tCA generation
for SPLs. We evaluated the adapted version of CASA using 133 publicly available
feature models and could record on average a speedup of $61.8\%$ of median
execution time, while at the same time preserving the coverage of the generated
array.


title:
N-photon Correlation Functions in N-slit Diffraction Experiments with
  Thermal Light

abstract:
  We discuss the analytic presentations of the high-order correlation functions
in the N-slit diffraction with thermal light in a recent paper [Phys. Rev.
Lett. 109, 233603 (2012)]. Our analysis shows that the superresolving fringes
in the high-order correlation measurement have two classical counterparts.


title: Desingularization of the Milne Universe

abstract:
  Resolution of cosmological singularities is an important problem in any full
theory of quantum gravity. The Milne orbifold is a cosmology with a
big-bang/big-crunch singularity, but being a quotient of flat space it holds
potential for resolution in string theory. It is known however, that some
perturbative string amplitudes diverge in the Milne geometry. Here we show that
flat space higher spin theories can effect a simple resolution of the Milne
singularity when one embeds the latter in 2+1 dimensions. We explain how to
reconcile this with the expectation that non-perturbative string effects are
required for resolving Milne. Along the way, we introduce a Grassmann
realization of the \.{I}n\"on\"u-Wigner contraction to export much of the AdS
technology to our flat space computation.


title: On the Randi\'{c} index and conditional parameters of a graph

abstract:
  The aim of this paper is to study some parameters of simple graphs related
with the degree of the vertices. So, our main tool is the $n\times n$ matrix
${\cal A}$ whose ($i,j$)-entry is $$ a_{ij}= \left\lbrace \begin{array}{ll}
  \frac{1}{\sqrt{\delta_i\delta_j}} & {\rm if }\quad v_i\sim v_j ;
  \\ 0 & {\rm otherwise,} \end{array}
  \right. $$ where $\delta_i$ denotes the degree of the vertex $v_i$. We study
the Randi\'{c} index and some interesting particular cases of conditional
excess, conditional Wiener index, and conditional diameter. In particular,
using the matrix ${\cal A}$ or its eigenvalues, we obtain tight bounds on the
studied parameters.


title: Structural, Magnetic, and Electrical Properties of Li2Ir1-xRuxO3

abstract:
  The crystal structure, resistivity, and magnetic susceptibility of the
Li2Ir1-xRuxO3 (x = 0-1) polycrystals have been investigated. We found that the
parent antiferromagnetic phase disappears for x > 0.2 and bond dimers appear in
the averaged structure for x > 0.5 and likely fluctuate for much smaller x.
Unexpectedly, this system remains insulating for all the doping levels, in
sharp contrast with the robust metallic state found in Sr2Ir1-xRuxO4. These
results demonstrate that the essential physics of the doped A2IrO3 (A = Li, Na)
system deviates significantly from the common one-band jeff=1/2 spin-orbit
model.


title:
Three particle Hyper Entanglement: Teleportation and Quantum Key
  Distribution

abstract:
  We present a scheme to generate three particle hyper-entanglement utilizing
polarization and orbital angular momentum (OAM) of a photon. We show that the
generated state can be used to teleport a two-qubit state described by the
polarization and the OAM. The proposed quantum system has also been used to
describe a new efficient quantum key distribution (QKD) protocol. We give a
sketch of the experimental arrangement to realize the proposed teleportation
and the QKD.


title: Global space-time models for climate ensembles

abstract:
  Global climate models aim to reproduce physical processes on a global scale
and predict quantities such as temperature given some forcing inputs. We
consider climate ensembles made of collections of such runs with different
initial conditions and forcing scenarios. The purpose of this work is to show
how the simulated temperatures in the ensemble can be reproduced (emulated)
with a global space/time statistical model that addresses the issue of
capturing nonstationarities in latitude more effectively than current
alternatives in the literature. The model we propose leads to a computationally
efficient estimation procedure and, by exploiting the gridded geometry of the
data, we can fit massive data sets with millions of simulated data within a few
hours. Given a training set of runs, the model efficiently emulates temperature
for very different scenarios and therefore is an appealing tool for impact
assessment.


title:
Bayesian Inference for Gaussian Process Classifiers with Annealing and
  Pseudo-Marginal MCMC

abstract:
  Kernel methods have revolutionized the fields of pattern recognition and
machine learning. Their success, however, critically depends on the choice of
kernel parameters. Using Gaussian process (GP) classification as a working
example, this paper focuses on Bayesian inference of covariance (kernel)
parameters using Markov chain Monte Carlo (MCMC) methods. The motivation is
that, compared to standard optimization of kernel parameters, they have been
systematically demonstrated to be superior in quantifying uncertainty in
predictions. Recently, the Pseudo-Marginal MCMC approach has been proposed as a
practical inference tool for GP models. In particular, it amounts in replacing
the analytically intractable marginal likelihood by an unbiased estimate
obtainable by approximate methods and importance sampling. After discussing the
potential drawbacks in employing importance sampling, this paper proposes the
application of annealed importance sampling. The results empirically
demonstrate that compared to importance sampling, annealed importance sampling
can reduce the variance of the estimate of the marginal likelihood
exponentially in the number of data at a computational cost that scales only
polynomially. The results on real data demonstrate that employing annealed
importance sampling in the Pseudo-Marginal MCMC approach represents a step
forward in the development of fully automated exact inference engines for GP
models.


title: Improved $\tau$-weapons for Higgs hunting

abstract:
  In this work, we use the results from Higgs searches in the $\gamma\gamma$
and $\tau\tau$ decay channels at LHC and indirect bounds as BR$(B \to X_s
\gamma)$ to constrain the parameter space of a generic MSSM Higgs sector. In
particular, we include the latest CMS results that look for additional Higgs
states with masses up to 1 TeV. We show that the $\tau \tau$ channel is the
best and most accurate weapon in the hunt for new Higgs states beyond the
Standard Model. We obtain that present experimental results rule out additional
neutral Higgs bosons in a generic MSSM below 300 GeV for any value of $\tan
\beta$ and, for instance, values of $\tan \beta$ above 30 are only possible for
Higgs masses above 600 GeV. ATLAS stored data has the potential to render this
bound obsolete in the near future.


title: Simulation of cohesive fine powders under a plane shear

abstract:
  Three dimensional molecular dynamics simulations of cohesive dissipative
powders under a plane shear are performed. We find the various phases depending
on the dimensionless shear rate and the dissipation rate as well as the
density. We also find that the shape of clusters depends on the initial
condition of velocities of particles when the dissipation is large. Our simple
stochastic model reproduces the non-Gaussian velocity distribution function
appearing in the coexistence phase of a gas and a plate.


title: Biprism Electron Interferometry with a Single Atom Tip Source

abstract:
  Experiments with electron or ion matter waves require a coherent,
monochromatic and long-term stable source with high brightness. These
requirements are best fulfilled by single atom tip (SAT) field emitters. The
performance of an iridium covered W(111) SAT is demonstrated and analyzed for
electrons in a biprism interferometer. Furthermore we characterize the emission
of the SAT in a separate field electron and field ion microscope and compare it
with other emitter types. A new method is presented to fabricate the
electrostatic charged biprism wire that separates and combines the matter wave.
In contrast to other biprism interferometers the source and the biprism size
are well defined within a few nanometers. The setup has direct applications in
ion interferometry and Aharonov-Bohm physics.


title: Propagation in 3D of microwaves through density perturbations

abstract:
  Simulations using 3D and 2D full-wave codes have shown that edge filaments in
tokamak plasmas can significantly affect the propagation of microwaves across a
broad frequency spectrum, resulting in scattering angles of up to 46 degrees.
Parameter scans were carried out for density perturbations comparable in width
and amplitude to MAST filaments and the effect on the measured emission was
calculated. 3D effects were discovered in the case of an obliquely incident
beam.
  In general, the problem of EM propagation past wavelength-sized 3D
inhomogeneities is not well understood, yet is of importance for both heating
and diagnostic applications in the electron cyclotron frequency range for
tokamaks, as well as atmospheric physics. To improve this understanding, a new
cold-plasma code, EMIT-3D, was written to extend full-wave microwave
simulations in magnetized plasmas to 3D, and make comparisons to the existing
2D code IPF-FDMC. This work supports MAST experiments using the SAMI diagnostic
to image microwave emission from the plasma edge due to mode conversion from
electron Bernstein waves. Significant fluctuations in the SAMI data mean that
detailed modelling is required to improve its interpretation.


title:
Fluctuation induced equality of multi-particle eccentricities for four
  or more particles

abstract:
  We discuss eccentricities (ellipticity and triangularity) generated in
nucleus-nucleus and proton-nucleus collisions. We define multi-particle
eccentricities $\epsilon_n\{m\}$ which are associated with the $n'th$ angular
multipole moment for $m$ particles. We show that in the limit of fluctuation
dominance all of the $\epsilon_n\{m\}$'s are approximately equal for $m \ge 4$.
For dynamics linearly responding to these eccentricities such as hydrodynamics
or proposed in this paper weakly interacting field theory, these relations
among eccentricities are translated into relations among flow moments
$v_n\{m\}$. We explicitly demonstrate it with hydrodynamic calculations.


title:
Influencing elections with statistics: Targeting voters with logistic
  regression trees

abstract:
  In political campaigning substantial resources are spent on voter
mobilization, that is, on identifying and influencing as many people as
possible to vote. Campaigns use statistical tools for deciding whom to target
("microtargeting"). In this paper we describe a nonpartisan campaign that aims
at increasing overall turnout using the example of the 2004 US presidential
election. Based on a real data set of 19,634 eligible voters from Ohio, we
introduce a modern statistical framework well suited for carrying out the main
tasks of voter targeting in a single sweep: predicting an individual's turnout
(or support) likelihood for a particular cause, party or candidate as well as
data-driven voter segmentation. Our framework, which we refer to as LORET (for
LOgistic REgression Trees), contains standard methods such as logistic
regression and classification trees as special cases and allows for a synthesis
of both techniques. For our case study, we explore various LORET models with
different regressors in the logistic model components and different
partitioning variables in the tree components; we analyze them in terms of
their predictive accuracy and compare the effect of using the full set of
available variables against using only a limited amount of information. We find
that augmenting a standard set of variables (such as age and voting history)
with additional predictor variables (such as the household composition in terms
of party affiliation) clearly improves predictive accuracy. We also find that
LORET models based on tree induction beat the unpartitioned models.
Furthermore, we illustrate how voter segmentation arises from our framework and
discuss the resulting profiles from a targeting point of view.


title: Unobtrusive Low Cost Pupil Size Measurements using Web cameras

abstract:
  Unobtrusive every day health monitoring can be of important use for the
elderly population. In particular, pupil size may be a valuable source of
information, since, apart from pathological cases, it can reveal the emotional
state, the fatigue and the ageing. To allow for unobtrusive monitoring to gain
acceptance, one should seek for efficient methods of monitoring using com- mon
low-cost hardware. This paper describes a method for monitoring pupil sizes
using a common web camera in real time. Our method works by first detecting the
face and the eyes area. Subsequently, optimal iris and sclera location and
radius, modelled as ellipses, are found using efficient filtering. Finally, the
pupil center and radius is estimated by optimal filtering within the area of
the iris. Experimental result show both the efficiency and the effectiveness of
our approach.


title:
H3K4 mono- and di-methyltransferase MLL4 is required for enhancer
  activation during cell differentiation

abstract:
  Enhancers play a central role in cell-type-specific gene expression and are
marked by H3K4me1/2. Active enhancers are further marked by H3K27ac. However,
the methyltransferases responsible for H3K4me1/2 on enhancers remain elusive.
Furthermore, how these enzymes function on enhancers to regulate
cell-type-specific gene expression is unclear. Here we identify MLL4 (KMT2D) as
a major mammalian H3K4 mono- and di-methyltransferase with partial functional
redundancy with MLL3 (KMT2C). Using adipogenesis and myogenesis as model
systems, we show that MLL4 exhibits cell-type- and
differentiation-stage-specific genomic binding and is predominantly localized
on enhancers. MLL4 co-localizes with lineage-determining transcription factors
(TFs) on active enhancers during differentiation. Deletion of MLL4 markedly
decreases H3K4me1/2, H3K27ac, Polymerase II and Mediator levels on enhancers
and leads to severe defects in cell-type-specific gene expression and cell
differentiation. Together, these findings identify MLL4 as a major mammalian
H3K4 mono- and di-methyltransferase essential for enhancer activation during
cell differentiation.


title: Gate controlled spin pumping at a quantum spin Hall edge

abstract:
  We propose a four-terminal device designed to manipulate by all electrical
means the spin of a magnetic adatom positioned at the edge of a quantum spin
Hall insulator. We show that an electrical gate, able to tune the interface
resistance between a quantum spin Hall insulator and the source and drain
electrodes, can switch the device between two regimes: one where the system
exhibits spin pumping and the other where the adatom remains in its ground
state. This demonstrates an all-electrical route to control single spins by
exploiting helical edge states of topological materials.


title: Multiprobe quantum spin Hall bars

abstract:
  We analyze electron transport in multiprobe quantum spin Hall (QSH) bars
using the B\"{u}ttiker formalism and draw parallels with their quantum Hall
(QH) counterparts. We find that in a QSH bar the measured resistance changes
upon introducing side voltage probes, in contrast to the QH case. We also study
four- and six-terminal geometries and derive the expressions for the
resistances. For these our analysis is generalized from the single-channel to
the multi-channel case and to the inclusion of backscattering originating from
a constriction placed within the bar.


title: Photon echo with a few photons in two-level atoms

abstract:
  To store and retrieve signals at the single photon level, various photon echo
schemes have resorted to complex preparation steps involving ancillary shelving
states in multi-level atoms. For the first time, we experimentally demonstrate
photon echo operation at such a low signal intensity without any preparation
step, which allows us to work with mere two-level atoms. This simplified
approach relies on the so-coined "Revival Of Silenced Echo" (ROSE) scheme. Low
noise conditions are obtained by returning the atoms to the ground state before
the echo emission. In the present paper we manage ROSE in photon counting
conditions, showing that very strong control fields can be compatible with
extremely weak signals, making ROSE consistent with quantum memory
requirements.


title: Dielectric function of a collisional plasma for arbitrary ionic charge

abstract:
  A simple model for the dielectric function of a completely ionized plasma
with an arbitrary ionic charge, that is valid for long-wavelength
high-frequency perturbations is derived using an approximate solution of a
linearized Fokker-Planck kinetic equation for electrons with a Landau collision
integral. The model accounts for both the electron-ion collisions and the
collisions of the subthermal (cold) electrons with thermal ones. The relative
contribution of the latter collisions to the dielectric function is treated
phenomenologically, introducing some parameter $\varkappa$ that is chosen in
such a way as to get a well-known expression for stationary electric
conductivity in the low-frequency region and fulfill the requirement of a
vanishing contribution of electron-electron collisions in the high-frequency
region. This procedure ensures the applicability of our model in a wide range
of plasma parameters as well as the frequency of the electromagnetic radiation.
Unlike the interpolation formula proposed earlier by Brantov et al. [Brantov et
al., JETP 106, 983 (2008)], our model fulfills the Kramers-Kronig relations and
permits a generalization for the cases of degenerate and strongly coupled
plasmas. With this in mind, a generalization of the well-known Lee-More model
[Y. T. Lee and R. M. More, Phys. Fluids 27, 1273 (1984)] for stationary
conductivity and its extension to dynamical conductivity [O. F. Kostenko and N.
E. Andreev, GSI Annual Report No. GSI-2008-2, 2008 (unpublished), p. 44] is
proposed for the case of plasmas with arbitrary ionic charge.


title: Logistic regression analysis with standardized markers

abstract:
  Two different approaches to analysis of data from diagnostic biomarker
studies are commonly employed. Logistic regression is used to fit models for
probability of disease given marker values, while ROC curves and risk
distributions are used to evaluate classification performance. In this paper we
present a method that simultaneously accomplishes both tasks. The key step is
to standardize markers relative to the nondiseased population before including
them in the logistic regression model. Among the advantages of this method are
the following: (i) ensuring that results from regression and performance
assessments are consistent with each other; (ii) allowing covariate adjustment
and covariate effects on ROC curves to be handled in a familiar way, and (iii)
providing a mechanism to incorporate important assumptions about structure in
the ROC curve into the fitted risk model. We develop the method in detail for
the problem of combining biomarker data sets derived from multiple studies,
populations or biomarker measurement platforms, when ROC curves are similar
across data sources. The methods are applicable to both cohort and case-control
sampling designs. The data set motivating this application concerns Prostate
Cancer Antigen 3 (PCA3) for diagnosis of prostate cancer in patients with or
without previous negative biopsy where the ROC curves for PCA3 are found to be
the same in the two populations. The estimated constrained maximum likelihood
and empirical likelihood estimators are derived. The estimators are compared in
simulation studies and the methods are illustrated with the PCA3 data set.


title: Around the stability of KAM-tori

abstract:
  We show that an analytic invariant torus $\cT_0$ with Diophantine frequency
$\o_0$ is never isolated due to the following alternative. If the Birkhoff
normal form of the Hamiltonian at $\cT_0$ satisfies a R\"ussmann transversality
condition, the torus $\cT_0$ is accumulated by KAM tori of positive total
measure. If the Birkhoff normal form is degenerate, there exists a subvariety
of dimension at least $d+1$ that is foliated by analytic invariant tori with
frequency $\o_0$.
  For frequency vectors $\o_0$ having a finite uniform Diophantine exponent
(this includes a residual set of Liouville vectors), we show that if the
Hamiltonian $H$ satisfies a Kolmogorov non degeneracy condition at $\cT_0$,
then $\cT_0$ is accumulated by KAM tori of positive total measure.
  In $4$ degrees of freedom or more, we construct for any $\o_0 \in \R^d$,
$C^\infty$ (Gevrey) Hamiltonians $H$ with a smooth invariant torus $\cT_0$ with
frequency $\o_0$ that is not accumulated by a positive measure of invariant
tori.


title:
From the Weyl quantization of a particle on the circle to number-phase
  Wigner functions

abstract:
  A generalized Weyl quantization formalism for a particle on the circle
investigated in \cite{1} is developed. A Wigner function for the state
$\hat{\varrho}$ and the kernel $\mathcal{K}$ for a particle on the circle is
defined and its properties are analyzed. Then it is shown how this Wigner
function can be easily modified to give the number-phase Wigner function in
quantum optics. Some examples of such number-phase Wigner function are
considered.


title: Phase-field-crystal models and mechanical equilibrium

abstract:
  Phase field crystal (PFC) models constitute a field theoretical approach to
solidification, melting and related phenomena at atomic length and diffusive
time scales. One of the advantages of these models is that they naturally
contain elastic excitations associated with strain in crystalline bodies.
However, instabilities that are diffusively driven towards equilibrium are
often orders of magnitude slower than the dynamics of the elastic excitations,
and are thus not included in the standard PFC model dynamics. We derive a
method to isolate the time evolution of the elastic excitations from the
diffusive dynamics in the PFC approach and set up a two-stage process, in which
elastic excitations are equilibrated separately. This ensures mechanical
equilibrium at all times. We show concrete examples demonstrating the necessity
of the separation of the elastic and diffusive time scales. In the small
deformation limit this approach is shown to agree with the theory of linear
elasticity.


title: Right-handed neutrino magnetic moments

abstract:
  We consider the most general dimension-five effective Lagrangian that can be
built using only Standard Model fields plus right-handed neutrinos, and find
that there exists a term that provides electroweak moments (i.e., couplings to
the Z and photon) for the right-handed neutrinos. Such term has not been
described previously in the literature. We discuss its phenomenology and the
bounds that can be derived from LEP results and from the observation of the
cooling process of red giants and supernovae.


title:
The geometric phase and the geometrodynamics of relativistic electron
  vortex beams

abstract:
  We have studied here the geometrodynamics of relativistic electron vortex
beams from the perspective of the geometric phase associated with the scalar
electron encircling the vortex line. It is pointed out that the electron vortex
beam carrying orbital angular momentum is a natural consequence of the skyrmion
model of a fermion. This follows from the quantization procedure of a fermion
in the framework of Nelson's stochastic mechanics when a direction vector
(vortex line) is introduced to depict the spin degrees of freedom. In this
formalism a fermion is depicted as a scalar particle encircling a vortex line.
It is here shown that when the Berry phase acquired by the scalar electron
encircling the vortex line involves quantized Dirac monopole we have paraxial
(non-paraxial) beam when the vortex line is parallel (orthogonal) to the
wavefront propagation direction. Non-paraxial beams incorporate spin-orbit
interaction. When the vortex line is tilted with respect to the propagation
direction the Berry phase involves non-quantized monopole. The temporal
variation of the direction of the tilted vortices is studied here taking into
account the renormalization group flow of the monopole charge and it is
predicted that this gives rise to spin Hall effect.


title: Aspects of the zero $\Lambda$ limit in the AdS/CFT correspondence

abstract:
  We examine the correspondence between QFT observables and bulk solutions in
the context of AdS/CFT in the limit as the cosmological constant $\Lambda \to
0$. We focus specifically on the spacetime metric and a non-backreacting scalar
in the bulk, compute the one-point functions of the dual operators and
determine the necessary conditions for the correspondence to admit a
well-behaved zero $\Lambda$ limit. We discuss holographic renormalization in
this limit and find that it requires schemes that partially break
diffeomorphism invariance of the bulk theory. In the specific case of three
bulk dimensions, we compute the zero $\Lambda$ limit of the holographic Weyl
anomaly and reproduce the central charge that arises in the central extension
of $\mathfrak{bms}_{3}$. We compute holographically the energy and momentum of
those QFT states dual to flat cosmological solutions and to the Kerr solution
and find an agreement with the bulk theory. We also compute holographically the
renormalized 2-point function of a scalar operator in the zero $\Lambda$ limit
and find it to be consistent with that of a conformal operator in two
dimensions less. Finally, our results can be used in a new definition of
asymptotic Ricci-flatness at null infinity based on the zero $\Lambda$ limit of
asymptotically Einstein manifolds.


title: On the tube-occupancy of sets in $\mathbb{R}^d$

abstract:
  Call a pair $(s,t) \in [0,d] \times [0,d]$ admissible, if there exists a
compact set $K \subset \mathbb{R}^{d}$ and a constant $C > 0$ such that $0 <
\mathcal{H}^{s}(K) < \infty$, and $$\mathcal{H}_{s}(K \cap T) \leq Cw(T)^{t}$$
for all tubes $T \subset \mathbb{R}^{d}$ of width $w(T)$. The purpose of this
paper is to show that all pairs $(s,s)$ with $s < 1$ are admissible. Combined
with previous results, this settles a question of A. Carbery.


title: Fluid Vesicles in Flow

abstract:
  We review the dynamical behavior of giant fluid vesicles in various types of
external hydrodynamic flow. The interplay between stresses arising from
membrane elasticity, hydrodynamic flows, and the ever present thermal
fluctuations leads to a rich phenomenology. In linear flows with both
rotational and elongational components, the properties of the tank-treading and
tumbling motions are now well described by theoretical and numerical models. At
the transition between these two regimes, strong shape deformations and
amplification of thermal fluctuations generate a new regime called trembling.
In this regime, the vesicle orientation oscillates quasi-periodically around
the flow direction while asymmetric deformations occur. For strong enough
flows, small-wavelength deformations like wrinkles are observed, similar to
what happens in a suddenly reversed elongational flow. In steady elongational
flow, vesicles with large excess areas deform into dumbbells at large flow
rates and pearling occurs for even stronger flows. In capillary flows with
parabolic flow profile, single vesicles migrate towards the center of the
channel, where they adopt symmetric shapes, for two reasons. First, walls exert
a hydrodynamic lift force which pushes them away. Second, shear stresses are
minimal at the tip of the flow. However, symmetry is broken for vesicles with
large excess areas, which flow off-center and deform asymmetrically. In
suspensions, hydrodynamic interactions between vesicles add up to these two
effects, making it challenging to deduce rheological properties from the
dynamics of individual vesicles. Further investigations of vesicles and similar
objects and their suspensions in steady or time-dependent flow will shed light
on phenomena such as blood flow.


title: The $L^2$-Alexander invariant detects the unknot

abstract:
  In this article, we present some of the properties of the $L^2$-Alexander
invariant of a knot defined by Li and Zhang, some of which are similar to those
of the classical Alexander polynomial. Notably we prove that the
$L^2$-Alexander invariant detects the trivial knot.


title:
Log concavity for matrix-valued functions and a matrix-valued Pr\'ekopa
  theorem

abstract:
  We give two different definitions of what it means for a matrix-valued
function to be log concave, guided by similar notions in complex differential
geometry. After discussing a few simple examples, we proceed to develop some of
the basic properties associated with these new concepts. Finally, we prove a
matrix-valued Pr\'ekopa theorem using a weighted, vector-valued Paley-Wiener
theorem, and positivity properties of direct image bundles.


title: Conservative effects in spin-transfer-driven magnetization dynamics

abstract:
  It is shown that under appropriate conditions spin-transfer-driven
magnetization dynamics in a single-domain nanomagnet is conservative in nature
and admits a specific integral of motion, which is reduced to the usual
magnetic energy when the spin current goes to zero. The existence of this
conservation law is connected to the symmetry properties of the dynamics under
simultaneous inversion of magnetisation and time. When one applies an external
magnetic field parallel to the spin polarization, the dynamics is transformed
from conservative into dissipative. More precisely, it is demonstrated that
there exists a state function such that the field induces a monotone relaxation
of this function toward its minima or maxima, depending on the field
orientation. These results hold in the absence of intrinsic damping effects.
When intrinsic damping is included in the description, a competition arises
between field-induced and damping-induced relaxations, which leads to the
appearance of limit cycles, that is, of magnetization self-oscillations.


title:
Hall Attractor in Axially Symmetric Magnetic Fields in Neutron Star
  Crusts

abstract:
  We have found an attractor for an axially symmetric magnetic field evolving
under the Hall effect and subdominant ohmic dissipation, resolving the question
of the long term fate of the magnetic field in neutron star crusts. The
electron fluid is in isorotation, analogous to Ferraro's law, with its angular
velocity being approximately proportional to the poloidal magnetic flux,
$\Omega \propto \Psi$. This equilibrium is the long term configuration of a
magnetic field evolving because of the Hall effect and ohmic dissipation. For
an initial dipole dominated field the attractor consists mainly of a dipole and
an octupole component accompanied by an energetically negligible quadrupole
toroidal field. The field dissipates in a self-similar way: although higher
multipoles should have been decaying faster, the toroidal field mediates
transfer of energy into them from the lower ones, leading to an advection
diffusion equilibrium and keeping the ratio of the poloidal multipoles almost
constant. This has implications for the structure of the intermediate age
neutron stars, suggesting that their poloidal field should consist of a dipole
and a octupole component accompanied by a very weak toroidal quadrupole. For
initial conditions that have a higher multipole $\ell$ structure the attractor
consists mainly of $\ell$ and $\ell+2$ poloidal components.


title: The Origin of Galactic Cosmic Rays

abstract:
  One century ago Viktor Hess carried out several balloon flights that led him
to conclude that the penetrating radiation responsible for the discharge of
electroscopes was of extraterrestrial origin. One century from the discovery of
this phenomenon seems to be a good time to stop and think about what we have
understood about Cosmic Rays. The aim of this review is to illustrate the ideas
that have been and are being explored in order to account for the observable
quantities related to cosmic rays and to summarize the numerous new pieces of
observation that are becoming available. In fact, despite the possible
impression that development in this field is somewhat slow, the rate of new
discoveries in the last decade or so has been impressive, and mainly driven by
beautiful pieces of observation. At the same time scientists in this field have
been able to propose new, fascinating ways to investigate particle acceleration
inside the sources, making use of multifrequency observations that range from
the radio, to the optical, to X-rays and gamma rays. These ideas can now be
confronted with data. I will mostly focus on supernova remnants as the most
plausible sources of Galactic cosmic rays, and I will review the main aspects
of the modern theory of diffusive particle acceleration at supernova remnant
shocks, with special attention for the dynamical reaction of accelerated
particles on the shock and the phenomenon of magnetic field amplification at
the shock. Cosmic ray escape from the sources is discussed as a necessary step
to determine the spectrum of cosmic rays at the Earth. In the end of this
review I will also discuss the phenomenon of cosmic ray acceleration at shocks
propagating in partially ionized media and the implications of this phenomenon
in terms of width of the Balmer line emission.


title:
Stationary plasmon-soliton waves in metal-dielectric nonlinear planar
  structures: modeling and properties

abstract:
  We present three complementary methods to study stationary nonlinear
solutions in one-dimensional nonlinear metal-dielectric structures. Two of them
use an approximate treatment of the Kerr type nonlinear term taking into
account only the leading electric field component, while the third one allows
for an exact treatment of the nonlinearity. A direct comparison of the results
obtained with all three models is presented and the excellent agreement between
them justifies the assumptions that have been used to construct the models. A
systematic study of the configurations made of two, three, or four layers, that
contain a semi-infinite Kerr type nonlinear dielectric, a metal film and linear
dielectrics is presented. Detailed analysis of properties, type and number of
solutions in these three types of structures is performed. The parameter ranges
where plasmon-soliton waves exist are found. The structures with realistic
opto-geometric parameters where plasmon-solitons exist at power levels already
used in spatial soliton studies are proposed and studied.


title:
Resilience of natural gas networks during conflicts, crises and
  disruptions

abstract:
  Human conflict, geopolitical crises, terrorist attacks, and natural disasters
can turn large parts of energy distribution networks offline. Europe's current
gas supply network is largely dependent on deliveries from Russia and North
Africa, creating vulnerabililties to social and political instabilities. During
crises, less delivery may mean greater congestion, as the pipeline network is
used in ways it has not been designed for. Given the importance of the security
of natural gas supply, we develop a model to handle network congestion on
various geographical scales. We offer a resilient response strategy to energy
shortages and quantify its effectiveness for a variety of relevant scenarios.
In essence, Europe's gas supply can be made robust even to major supply
disruptions, if a fair distribution strategy is applied.


title: Combinatorial aspects of exceptional sequences on (rational) surfaces

abstract:
  We investigate combinatorial aspects of exceptional sequences in the derived
category of coherent sheaves on certain smooth and complete algebraic surfaces.
We show that to any such sequence there is canonically associated a complete
toric surface whose torus fixpoints are either smooth or cyclic T-singularities
(in the sense of Wahl) of type $\frac{1}{r^2}(1, kr - 1)$. We also show that
any exceptional sequence can be transformed by mutation into an exceptional
sequence which consists only of objects of rank one.


title:
CFT adapted approach to massless fermionic fields, AdS/CFT, and
  fermionic conformal fields

abstract:
  Fermionic totally symmetric arbitrary spin massless fields in AdS space of
dimension greater than or equal to four are studied. Using Poincar\'e
parametrization of AdS space, CFT adapted gauge invariant formulation for such
fields is developed. We demonstrate that the curvature and radial coordinate
contributions to Lagrangian and gauge transformation of the AdS fields can be
expressed in terms of ladder operators. Covariant and modified de Donder gauge
conditions are proposed. The modified de Donder gauge leads to decoupled
equations of motion which can easily be solved in terms of the Bessel function.
The AdS/CFT correspondence for conformal current and shadow field and the
respective normalizable and non-normalizable modes of fermionic massless AdS
field is studied. The AdS field is considered by using the modified de Donder
gauge which simplifies considerably the study of AdS/CFT correspondence. We
show that on-shell leftover gauge symmetries of bulk massless field are related
to gauge symmetries of boundary conformal current and shadow field. We compute
the bulk action on solution of the Dirichlet problem and obtain two-point gauge
invariant vertex of shadow field. Also we shown that the UV divergence of the
two-point gauge invariant vertex gives higher-derivative action of fermionic
conformal field.


title: Quark-antiquark static energy from a restricted Fourier transform

abstract:
  We provide a fully analytical determination of the perturbative
quark-antiquark static energy in position space as defined by a restricted
Fourier transformation from momentum to position space. Such a determination is
complicated by the fact that the static energy genuinely decomposes into a
strictly perturbative part (made up of contributions $\sim\alpha_s^n$, with
$n\in\mathbb{N}$) which is conventionally evaluated in momentum space, and a
so-called ultrasoft part (including terms $\sim\alpha_s^{n+m}\ln^m\alpha_s$,
with $n\geq3$ and $m\in\mathbb{N}$) which, conversely, is naturally evaluated
in position space. Our approach facilitates the explicit determination of the
static energy in position space at the accuracy with which the perturbative
potential in momentum space is known, i.e., presently up to order $\alpha_s^4$.


title: A Superclass of the Posinormal Operators

abstract:
  The starting place is a brief proof of a well-known result, the hyponormality
of $C_k$ (the generalized Ces\`{a}ro operator of order one) for $k \geq 1$.
This leads to the definition of a superclass of the posinormal operators. It is
shown that all the injective unilateral weighted shifts belong to this
superclass.
  Sufficient conditions are determined for an operator in this superclass to be
posinormal and hyponormal. A connection is established between this superclass
and some recently-published sufficient conditions for a lower triangular
factorable matrix to be a hyponormal bounded linear operator on $\ell^2$.


title:
Effect of La Doping on the Crystal Structure, Electric, Magnetic and
  Morphologic Properties of the BSCCO System

abstract:
  Studies of the doping process can provide a better understanding of the
superconducting mechanisms in cuprous oxide materials. In this work, we studied
the doping effects on the crystal structure, electric, morphologic and magnetic
properties of the BSCCO system with the nominal composition
$Bi_{1.6}Pb_{0.4}Sr_{(2-x)}RE_xCa_2Cu_3O_{(10-{\delta})}$. Here, the rare earth
element (RE) was replaced by La in the sites of Sr. The x was ranged from 0.0
to 2.0, in steps of 0.5. The samples were prepared based on Pechini's method.
The resulting powder was pressed at room temperature and the pellets were
submitted to several heat treatments. The characterizations confirm the La in
the sites of Sr however, the superconducting properties of the sample were not
improved.


title:
Topological Lifshitz phase transition in effective model of QCD with
  chiral symmetry non-restoration

abstract:
  The topological Lifshitz phase transition is studied systematically within an
effective model of QCD, in which the chiral symmetry, broken at zero
temperature, is not restored at high temperature and/or baryon chemical
potential. It is found that during phase transition the quark system undergoes
a first-order transition from low density fully-gapped state to high density
state with Fermi sphere which is protected by momentum-space topology. The
Lifshitz phase diagram in the plane of temperature and baryon chemical
potential is established. The critical behaviors of various equations of state
are determined.


title:
Convergence of simulations of self-gravitating accretion discs II:
  Sensitivity to the implementation of radiative cooling and artificial
  viscosity

abstract:
  Recently it has been suggested that the fragmentation boundary in Smoothed
Particle Hydrodynamic (SPH) and FARGO simulations of self-gravitating accretion
discs with beta-cooling do not converge as resolution is increased.
Furthermore, this recent work suggests that by carefully optimising the
artificial viscosity parameters in these codes it can be shown that
fragmentation may occur for much longer cooling times than earlier work
suggests. If correct, this result is intriguing as it suggests that gas giant
planets could form, via direct gravitational collapse, reasonably close to
their parent stars. This result is, however, slightly surprising and there have
been a number of recent studies suggesting that the result is likely an
indication of a numerical problem with the simulations. One suggestion, in
particular, is that the SPH results are influenced by the manner in which the
cooling is implemented. We extend this work here and show that if the cooling
is implemented in a manner that removes a known numerical artefact in the shock
regions, the fragmentation boundary converges to a value consistent with
earlier work and that fragmentation is unlikely for the long cooling times
suggested by this recent work. We also investigate the optimisation of the
artificial viscosity parameters and show that the values that appear optimal
are likely introducing numerical problems in both the SPH and FARGO
simulations. We therefore conclude that earlier predictions for the cooling
times required for fragmentation are likely correct and that, as suggested by
this earlier work, fragmentation cannot occur in the inner parts (r < 50 au) of
typical protostellar discs.


title:
Probing fragmentation functions from same-side hadron-jet momentum
  correlations in p-p collisions

abstract:
  A next-to-leading order (NLO) analysis of hadron-jet momentum correlations in
p-p collisions at the LHC is carried out. We show that the inclusive charged
hadron momentum distributions inside jets is a very sensitive observable which
allows one to disentangle among various fragmentation function sets presently
available. Correlations with identified hadrons (kaons, protons) are
investigated as well.


title: On the List Update Problem with Advice

abstract:
  We study the online list update problem under the advice model of
computation. Under this model, an online algorithm receives partial information
about the unknown parts of the input in the form of some bits of advice
generated by a benevolent offline oracle. We show that advice of linear size is
required and sufficient for a deterministic algorithm to achieve an optimal
solution or even a competitive ratio better than $15/14$. On the other hand, we
show that surprisingly two bits of advice are sufficient to break the lower
bound of $2$ on the competitive ratio of deterministic online algorithms and
achieve a deterministic algorithm with a competitive ratio of $5/3$. In this
upper-bound argument, the bits of advice determine the algorithm with smaller
cost among three classical online algorithms, TIMESTAMP and two members of the
MTF2 family of algorithms. We also show that MTF2 algorithms are
$2.5$-competitive.


title:
Uncertainties in grid-based estimates of stellar mass and radius.
  SCEPtER: Stellar CharactEristics Pisa Estimation gRid

abstract:
  Some aspects of the systematic and statistical errors affecting grid-based
estimation of stellar masses and radii have still not been investigated well.
We study the impact on mass and radius determination of the uncertainty in the
input physics, in the mixing-length value, in the initial helium abundance, and
in the microscopic diffusion efficiency adopted in stellar model computations.
We consider stars with mass in the range [0.8 - 1.1] Msun and evolutionary
stages from the zero-age main sequence to the central hydrogen exhaustion.
Stellar parameters were recovered by a maximum-likelihood technique, comparing
the observations constraints to a grid of stellar models. Synthetic grids with
perturbed input were adopted to estimate the systematic errors arising from the
current uncertainty in model computations. We found that the statistical error
components, owing to the current typical uncertainty in the observations, are
nearly constant in all cases at about 4.5% and 2.2% on mass and radius
determination, respectively. The systematic bias on mass and radius
determination due to a variation of $\pm$ 1 in Delta Y/Delta Z is $\pm$ 2.3%
and $\pm$ 1.1%; the one due to a change of $\pm$ 0.24 in the value of the
mixing-length is $\pm$ 2.1% and $\pm$ 1.0%; the one due to a variation of $\pm$
5% in the radiative opacity is $\mp$ 1.0% and $\mp$ 0.45%. An important bias
source is to neglect microscopic diffusion, which accounts for errors of about
3.7% and 1.5% on mass and radius. The cumulative effects of the considered
uncertainty sources can produce biased estimates of stellar characteristics.
Comparison of the results of our technique with other grid techniques shows
that the systematic biases induced by the differences in the estimation grids
are generally greater than the statistical errors involved.


title:
Zak transforms and Gabor frames of totally positive functions and
  exponential B-splines

abstract:
  We study totally positive (TP) functions of finite type and exponential
B-splines as window functions for Gabor frames. We establish the connection of
the Zak transform of these two classes of functions and prove that the Zak
transforms have only one zero in their fundamental domain of quasi-periodicity.
Our proof is based on the variation-diminishing property of shifts of
exponential B-splines. For the exponential B-spline B_m of order m, we
determine a large set of lattice parameters a,b>0 such that the Gabor family of
time-frequency shifts is a frame for L^2(R). By the connection of its Zak
transform to the Zak transform of TP functions of finite type, our result
provides an alternative proof that TP functions of finite type provide Gabor
frames for all lattice parameters with ab<1. For even two-sided exponentials
and the related exponential B-spline of order 2, we find lower frame-bounds A,
which show the asymptotically linear decay A (1-ab) as the density ab of the
time-frequency lattice tends to the critical density ab=1.


title: On Einstein-Cartan Theory: I. Kinematical description

abstract:
  Equations of motion for general gravitational connection and orthonormal
coframe from the Einstein-Hilbert type action are derived. Our formulation does
not fix coframe to be tangential to spatial section hence Lorentz group is
still present as a part of gauge freedom. 3+1 decomposition introduces tangent
Minkowski structures hence Hamilton-Dirac approach to dynamics works with
Lorentz connection over the spatial section. The second class constraints are
analyzed and Dirac bracket is defined. Reduction of the phase space is
performed and canonical coordinates are introduced.


title:
Strong-disorder magnetic quantum phase transitions: Status and new
  developments

abstract:
  This article reviews the unconventional effects of random disorder on
magnetic quantum phase transitions, focusing on a number of new experimental
and theoretical developments during the last three years. On the theory side,
we address smeared quantum phase transitions tuned by changing the chemical
composition, for example in alloys of the type A$_{1-x}$B$_x$. We also discuss
how the interplay of order parameter conservation and overdamped dynamics leads
to enhanced quantum Griffiths singularities in disordered metallic
ferromagnets. Finally, we discuss a semiclassical theory of transport
properties in quantum Griffiths phases. Experimental examples include the
ruthenates Sr$_{1-x}$Ca$_x$RuO$_3$ and (Sr$_{1-x}$Ca$_x$)$_3$Ru$_2$O$_7$ as
well as Ba(Fe$_{1-x}$Mn$_x$)$_2$As$_2$.


title: Rare Charm Decays at LHCb

abstract:
  Studies of rare decays are an indirect probe of New Physics (NP). This
document presents recent measurements of rare decays in the charm sector by the
LHCb experiment. The analyses are performed with proton-proton collision data
at $\sqrt{s}$ = 7 TeV recorded in 2011.


title: Regularity and long-time behavior of nonlocal heat flows

abstract:
  This article considers nonlocal heat flows into a singular target space. The
problem is the parabolic analogue of a stationary problem that arises as the
limit of a singularly perturbed elliptic system. It also provides a gradient
flow approach to an optimal eigenvalue partition problem that, in light of the
work of Caffarelli and Lin, is equivalent to a constrained harmonic mapping
problem. In particular, we show that weak solutions of our heat equation
converge as time approaches infinity to stationary solutions of this mapping
problem. For these weak solutions, we also prove Lipschitz continuity and
regularity of free interfaces, making use of a parabolic Almgren-type
monotonicity formula.


title: Open Charm Spectroscopy and Mass Measurements in LHCb

abstract:
  A study of $D^+\pi^-$, $D^0 \pi^+$ and $D^{*+}\pi^-$ final states is
performed using pp collision data, corresponding to an integrated luminosity of
1.0 $fb^{-1}$, collected at a centre-of-mass energy of 7 TeV with the LHCb
detector. The $D_1(2420)^0$ resonance is observed in the $D^{*+}\pi^-$ final
state and the $D^*_2(2460)$ resonance is observed in the $D^+\pi^-$, $D^0
\pi^+$ and $D^{*+}\pi^-$ final states. For both resonances, their properties
and spin-parity assignments are obtained. In addition, two natural parity and
two unnatural parity resonances are observed in the mass region between 2500
and 2800 MeV. Further structures in the region around 3000 MeV are observed in
all the $D^{*+}\pi^-$, $D^+\pi^-$ and $D^0 \pi^+$ final states. Using three-
and four-body decays of $D$ mesons produced in semileptonic $b$-hadron decays,
precision measurements of $D$ meson mass differences are made together with a
measurement of the $D^{0}$ mass.


title: Fracture simulation for zirconia toughened alumina microstructure

abstract:
  Purpose - The purpose of this paper is to describe finite element modelling
for fracture and fatigue behaviour of zirconia toughened alumina
microstructures. Design/methodology/approach - A two-dimensional finite element
model is developed with an actual $Al{_2}O{_3}$ - 10 vol% $ZrO{_2}$
microstructure. A bilinear, time-independent cohesive zone law is implemented
for describing fracture behaviour of grain boundaries. Simulation conditions
are similar to those found at contact between a head and a cup of hip
prosthesis. Residual stresses arisen from the mismatch of thermal coefficient
between grains are determined. Then, effects of a micro-void and contact stress
magnitude are investigated with models containing residual stresses. For the
purpose of simulating fatigue behaviour, cyclic loadings are applied to the
models. Findings - Results show that crack density is gradually increased with
increasing magnitude of contact stress or number of fatigue cycles. It is also
identified that a micro-void brings about the increase of crack density rate.
Social implications - This paper is the first step for predicting the lifetime
of ceramic implants. The social implications would appear in the next few years
about health issues. Originality/value - This proposed finite element method
allows describing fracture and fatigue behaviours of alumina-zirconia
microstructures for hip prosthesis, provided that a microstructure image is
available.


title: Resonance spectroscopy of gravitational states of antihydrogen

abstract:
  We study a method to induce resonant transitions between antihydrogen quantum
states above a material surface in the gravitational field of the Earth. The
method consists in applying a gradient of magnetic field which is temporally
oscillating with the frequency equal to a frequency of a transition between
gravitational states of antihydrogen. Corresponding resonant change in a
spatial density of antihydrogen atoms can be measured as a function of the
frequency of applied field. We estimate an accuracy of measuring antihydrogen
gravitational states spacing and show how a value of the gravitational mass of
the antihydrogen atom can be deduced from such a measurement.