title: Discovering the Markov network structure

abstract:
  In this paper a new proof is given for the supermodularity of information
content. Using the decomposability of the information content an algorithm is
given for discovering the Markov network graph structure endowed by the
pairwise Markov property of a given probability distribution. A discrete
probability distribution is given for which the equivalence of
Hammersley-Clifford theorem is fulfilled although some of the possible vector
realizations are taken on with zero probability. Our algorithm for discovering
the pairwise Markov network is illustrated on this example, too.


title:
Force Spectroscopy with Dual-Trap Optical Tweezers: Molecular Stiffness
  Measurements and Coupled Fluctuations Analysis

abstract:
  Dual trap optical tweezers are often used in high-resolution measurements in
single-molecule biophysics. Such measurements can be hindered by the presence
of extraneous noise sources, the most prominent of which is the coupling of
fluctuations along different spatial directions, which may affect any optical
tweezers setup. In this paper we analyze, both from the theoretical and the
experimental points of view, the most common source for these couplings in Dual
Trap Optical Tweezers setups: the misalignment of traps and tether. We give
criteria to distinguish different kinds of misalignment, to estimate their
quantitative relevance and to include them in the data analysis. The
experimental data is obtained in a novel dual trap optical tweezers setup which
directly measures forces. In the case in which misalignment is negligible we
provide a method to measure the stiffness of traps and tether based on variance
analysis. This method can be seen as a calibration technique valid beyond the
linear trap region. Our analysis is then employed to measure the persistence
length of ds-DNA tethers of three different lengths spanning two orders of
magnitude. The effective persistence length of such tethers is shown to
decrease with the contour length, in accordance with previous studies.


title:
Hydrostatic pressure effect on Tc of new BiS2 based Bi4O4S3 and
  NdO0.5F0.5BiS2 layered superconductors

abstract:
  We investigate the external hydrostatic pressure effect on the
superconducting transition temperature (Tc) of new layered superconductors
Bi4O4S3 and NdO0.5F0.5BiS2. Though the Tc is found to have moderate decrease
from 4.8 K to 4.3 K (dTconset/dP = -0.28 K/GPa) for Bi4O4S3 superconductor, the
same increases from 4.6 K to 5 K (dTconset/dP = 0.44 K/GPa) upto 1.31 GPa
followed by a sudden decrease from 5 K to 4.7 K upto 1.75 GPa for
NdO0.5F0.5BiS2 superconductor. The variation of Tc in these systems may be
correlated to increase or decrease of the charge carriers in the density of
states under externally applied pressure.


title: Square Turning Maps and their Compactifications

abstract:
  In this paper we introduce some infinite rectangle exchange transformations
which are based on the simultaneous turning of the squares within a sequence of
square grids. We will show that such noncompact systems have higher dimensional
dynamical compactifications. In good cases, these compactifications are
polytope exchange transformations based on pairs of Euclidean lattices. In each
dimension $8m+4$ there is a $4m+2$ dimensional family of them. Here
$m=0,1,2,...$ The case $m=0$, which we studied in depth in an earlier paper,
has close connections to the $E_4$ Weyl group and the $(2,4,\infty)$ hyperbolic
triangle group.


title: Fluctuation Pressure of Biomembranes in Planar Confinement

abstract:
  The fluctuation pressure of a lipid-bilayer membrane is important for the
stability of lamellar phases and the adhesion of membranes to surfaces. In
contrast to many theoretical studies, which predict a decrease of the pressure
with the cubed inverse distance between the membranes, Freund suggested very
recently a linear inverse distance dependence [Proc. Natl. Acad. Sci. U.S.A.
110, 2047 (2013)]. We address this discrepancy by performing Monte Carlo
simulations for a membrane model discretized on a square lattice and employ the
wall theorem to evaluate the pressure for a single membrane between parallel
walls. For distances that are small compared with the lattice constant, the
pressure indeed depends on the inverse distance as predicted by Freund. For
intermediate distances, the pressure depends on the cubed inverse distance as
predicted by Helfrich [Z. Naturforsch. A 33, 305 (1978)]. Here, the crossover
length between the two regimes is a molecular length scale. Finally, for
distances large compared with the mean squared fluctuations of the membrane,
the entire membrane acts as a soft particle and the pressure on the walls again
depends linearly on the inverse distance.


title: Bounds of some parameters of elliptic curve on finite field

abstract:
  I prove lower bounds of some parameters of elliptic curve over finite field.
There parameters are closely interrelated with cryptographic stability of
elliptic curve.


title: Photoluminescence in amorphous MgSiO_3 silicate

abstract:
  Samples of amorphous MgSiO_3 annealed at temperature steps leading up to
their crystallisation temperature show a rise in photoluminescence activity,
peaking at ~450C. The photoluminescence band has a main peak at 595nm and a
weaker peak at 624nm. We present laboratory data to show that the maximum in
photoluminescence activity is related to substantial structural reordering that
occurs within a relatively narrow temperature range. We attribute the origin of
the photoluminescence to non-bridging oxygen hole centre defects, which form
around ordered nano-sized domain structures as a result of the breakup of
tetrahedral connectivity in the disordered inter-domain network, aided by the
loss of bonded OH. These defects are removed as crystallisation progresses,
resulting in the decrease and eventual loss of photoluminescence. Thermally
processed hydrogenated amorphous silicate grains could therefore represent a
potential carrier of extended red emission.


title: Entropy functions and functional equations

abstract:
  The purpose of this note is to give the general solution of two functional
equations connected to the Shannon entropy and also to the Tsallis entropy. As
a result of this, we present the regular solution of these equations, as well.
Furthermore, we point out that the regularity assumptions used in previous
works can substantially be weakened.


title:
Playing quantum hide-and-seek with the muon: localizing muon stopping
  sites

abstract:
  One of the most fundamental limitations of a muon-spin relaxation experiment
can be the lack of knowledge of the implantation site of the muon and the
uncertainty about the muon's perturbation of its host. Here we review some of
the work done on the `muon site problem' in the solid state and highlight some
recent applications of electronic structure calculations that have successfully
characterized the quantum states of muons in a number of insulating compounds
containing fluorine, in a number of pnictide superconductors, and in ZnO.


title: Efficiently Extracting Energy from Cosmological Neutrinos

abstract:
  Detecting the extremely low-energy neutrinos that form the Cosmic Neutrino
Background (CNB) presents many experimental challenges, but pursuing this
elusive goal is still worthwhile because these weakly-interacting particles
could provide a new window into the structure and composition of the early
universe. This report examines whether cosmological neutrinos can deposit
sufficient energy into a target system to be detectable with plausible
extensions of current bolometric technologies. While the macroscopic
wavelengths of cosmological neutrinos can greatly enhance their cross sections
with dense targets, such interactions can only be detectable if they transfer a
significant fraction of each neutrino's kinetic energy into the detector
system. We find that a large array of dense target masses coupled to suitable
motion-sensitive circuits could potentially satisfy both of these conditions
and thus might be able to serve as the basis for a more practical cosmological
neutrino detector.


title:
General and alien solutions of a functional equation and of a functional
  inequality

abstract:
  The purpose of the present paper is to solve (under some assumption on the
domain) the equation $$ g(x+y)-g(x)-g(y)=xf(y)+yf(x). $$ After determining the
general solutions, we will investigate the so--called alien solutions. %More
precisely, we will examine the cases when the above equation implies that
%$g(x+y)=g(x)+g(y)$ and $xf(y)+yf(x)=0$. %Concerning this, necessary and
sufficient conditions will be provided. Finally, we will discuss the real
solutions of the following related functional inequality: $$
g(x+y)-g(x)-g(y)\geq xf(y)+yf(x). $$


title:
The Structure of the Closure of the Rational Functions in
  $L^{q}$($\mu$)$

abstract:
  Let $K$ be a compact subset in the complex plane and let $A(K)$ be the
uniform closure of the functions continuous on $K$ and analytic on $K^{\circ}$.
Let $\mu$ be a positive finite measure with its support contained in $K$. For
$1 \leq q < \infty$, let $A^{q}(K,\mu)$ denote the closure of $A(K)$ in
$L^{q}(\mu)$. The aim of this work is to study the structure of the space
$A^{q}(K,\mu)$. We seek a necessary and sufficient condition on $K$ so that a
Thomson-type structure theorem for $A^{q}(K,\mu)$ can be established. Our
results essentially give perfect solutions to the major open problem in the
research filed of theory of subnormal operators and aproximation by analytic
functions in the mean .


title: On the modified entropy equation

abstract:
  The object of this paper is to solve the so--called modified entropy equation
\[ f<x, y, z>=f<x, y+z, \mathbf{0}>+ \mu<y+z>f<\mathbf{0}, \frac{y}{y+z},
\frac{z}{y+z}>, \] on the positive cone of $\R^{k}$, where $\mu$ is a given
multiplicative function on this cone. After that the regular solutions of this
equation are determined. Furthermore we investigate its connection between the
entropy equation and other equations, as well.


title:
Stability of the parametric fundamental equation of information for
  nonpositive parameters

abstract:
  In this note we prove that the parametric fundamental equation of information
is stable in the sense of Hyers and Ulam provided that the parameter is
nonpositive. We also prove, as a corollary, that the system of equations that
defines the recursive and semi-symmetric information measures depending on a
nonpositive parameter is stable in a certain sense.


title:
Recent results on the stability of the parametric fundamental equation
  of information

abstract:
  The purpose of this paper is to summarize the recent results on the stability
of the parametric fundamental equation of information. Furthermore, by the help
of a modification of a method we used in \cite{GM08} we shall give a unified
proof for the Hyers--Ulam stability of the equation in question, assuming that
the parameter does not equal to 1. As a corollary of the main result, a system
of equations, that defines the recursive and semi--symmetric information
measures is also discussed.


title:
The interplay of sedimentation and crystallization in hard-sphere
  suspensions

abstract:
  We study crystal nucleation under the influence of sedimentation in a model
of colloidal hard spheres via Brownian Dynamics simulations. We introduce two
external fields acting on the colloidal fluid: a uniform gravitational field
(body force), and a surface field imposed by pinning a layer of equilibrium
particles (rough wall). We show that crystal nucleation is suppressed in
proximity of the wall due to the slowing down of the dynamics, and that the
spatial range of this effect is governed by the static length scale of bond
orientational order. For distances from the wall larger than this length scale,
the nucleation rate is greatly enhanced by the process of sedimentation, since
it leads to a higher volume fraction, or a higher degree of supercooling, near
the bottom. The nucleation stage is similar to the homogeneous case, with
nuclei being on average spherical and having crystalline planes randomly
oriented in space. The growth stage is instead greatly affected by the symmetry
breaking introduced by the gravitation field, with a slowing down of the
attachment rate due to density gradients, which in turn cause nuclei to grow
faster laterally. Our findings suggest that the increase of crystal nucleation
in higher density regions might be the cause of the large discrepancy in the
crystal nucleation rate of hard spheres between experiments and simulations, on
noting that the gravitational effects in previous experiments are not
negligible.


title:
Evidence for quiescent synchrotron emission in the black hole X-ray
  transient Swift J1357.2-0933

abstract:
  We present high time-resolution ULTRACAM optical and NOTCam infrared
observations of the edge-on black hole X-ray transient Swift J1357.2-0933. Our
data taken in 2012 and 2013 show the system to be at its pre-outburst magnitude
and so the system is in quiescence. In contrast to other X-ray transients, the
quiescent light curves of Swift J1357.2-0933 do not show the secondary star's
ellipsoidal modulation. The optical light curve is dominated by variability
with an optical fractional rms of ~35 per cent, a factor of >3 larger than what
is observed in other systems at similar time-resolution. Optical flare events
lasting 2-10min with amplitudes of up to ~1.5 mag are seen as well as numerous
rapid ~0.8 mag dip events which are similar to the optical dips seen in
outburst. Similarly the infrared J-band light curve is dominated by variability
with a fractional rms of ~21 per cent and flare events lasting 10--30 min with
amplitudes of up to ~1.5 mag are observed. The quiescent optical to
mid-infrared spectral energy distribution in quiescence is dominated by a
non-thermal component with a power--law index of -1.4, (the broad-band rms SED
has a similar index) which arises from optically thin synchrotron emission most
likely originating in a weak jet; the lack of a peak in the spectral energy
distribution rules out advection-dominated models. Using the outburst
amplitude--period relation for X-ray transients we estimate the quiescent
magnitude of the secondary star to lie in the range V_min=22.7 to 25.6, which
when combined with the absolute magnitude of the expected M4.5 V secondary star
allows us to constrain to the distance to lie in the range 0.5 to 6.3 kpc.
(Abridged)


title: A characterization of the relative entropies

abstract:
  In this note we give a characterization of a family of relative entropies on
open domain depending on a real parameter $\alpha$ based on recursivity and
symmetry. In the cases $\alpha=1$ and $\alpha=0$ we use additionally a weak
regularity assumption while in the other cases no regularity assumptions are
made at all.


title:
Explicit exponential Runge-Kutta methods of high order for parabolic
  problems

abstract:
  Exponential Runge-Kutta methods constitute efficient integrators for
semilinear stiff problems. So far, however, explicit exponential Runge-Kutta
methods are available in the literature up to order 4 only. The aim of this
paper is to construct a fifth-order method. For this purpose, we make use of a
novel approach to derive the stiff order conditions for high-order exponential
methods. This allows us to obtain the conditions for a method of order 5 in an
elegant way. After stating the conditions, we first show that there does not
exist an explicit exponential Runge-Kutta method of order 5 with less than or
equal to 6 stages. Then, we construct a fifth-order method with 8 stages and
prove its convergence for semilinear parabolic problems. Finally, a numerical
example is given that illustrates our convergence bound.


title:
Exact Rotational Space-time Transformations, Davies-Jennison Experiments
  and Limiting Lorentz-Poincar\'e Invariance

abstract:
  Jennison deduced from the rotational experiments that a rotating radius $r_r$
measured by the rotating observer is contracted by $r_r = r(1-\om^2
r^2/c^2)^{1/2}$, compared with the radius $r$ measured in an inertial frame.
This conclusion differs from the result based on Lorentz transformations. Since
rotational frames are not equivalent to inertial frames, we analyze the
rotational experiments by using the exact rotational space-time transformations
rather than the Lorentz transformations. We derive exact rotational
transformations on the basis of the principle of limiting Lorentz-Poincar\'e
invariance. The exact rotational transformations form a pseudo-group rather
than the usual Lie group. They support Jennison's contraction of a rotating
radius and are consistent with two Davies-Jennison experiments. We also suggest
new experimental tests for the exact rotational transformations.


title: Categories of assemblies for realizability

abstract:
  This paper introduces categories of assemblies which are closely connected to
realizability interpretations and which are based on an important subcategory
of the effective topos. There is a list of properties which characterize these
categories of assemblies up to equivalence.


title: On the stability of the modified entropy equation

abstract:
  The aim of this paper is to prove that under some conditions the modified
entropy equation is stable on its one-dimensional domain.


title: Fluctuations around Hartree states in the mean-field regime

abstract:
  We consider the dynamics of a large system of N interacting bosons in the
mean-field regime where the interaction is of order 1/N. We prove that the
fluctuations around the nonlinear Hartree state are generated by an effective
quadratic Hamiltonian in Fock space, which is derived from Bogoliubov's
approximation. We use a direct method in the N-particle space, which is
different from the one based on coherent states in Fock space.


title:
Stability type results concerning the fundamental equation of
  information of multiplicative type

abstract:
  The paper deals with the stability of the fundamental equation of information
of multiplicative type. It will be proved that the equation in question is
stable in the sense of Hyers and Ulam under some assumptions. This result will
be applied to prove the stability of a system of functional equations that
characterizes the recursive measures of information of multiplicative type.


title:
From P100 to P100_: Conception and improvement of a new citation-rank
  approach in bibliometrics

abstract:
  Properties of a percentile-based rating scale needed in bibliometrics are
formulated. Based on these properties, P100 was recently introduced as a new
citation-rank approach (Bornmann, Leydesdorff, & Wang, in press). In this
paper, we conceptualize P100 and propose an improvement which we call P100_.
Advantages and disadvantages of citation-rank indicators are noted.


title:
The formation of entropy cores in non-radiative galaxy cluster
  simulations: SPH versus AMR

abstract:
  Abridged: We simulate a massive galaxy cluster in a LCDM Universe using three
different approaches to solving the equations of non-radiative hydrodynamics:
`classic' Smoothed Particle Hydrodynamics (SPH); a novel SPH with a higher
order dissipation switch (SPHS); and adaptive mesh refinement (AMR). We find
that SPHS and AMR are in excellent agreement, with both forming a well-defined
entropy core that rapidly converges with increasing mass and force resolution.
By contrast, SPH exhibits rather different behaviour. At low redshift, entropy
decreases systematically with decreasing cluster-centric radius, converging on
ever lower central values with increasing resolution. At higher redshift, SPH
is in better agreement with SPHS and AMR but shows much poorer numerical
convergence. We trace these discrepancies to artificial surface tension in SPH
at phase boundaries. At early times, the passage of massive substructures close
to the cluster centre stirs and shocks gas to build an entropy core. At later
times, artificial surface tension causes low entropy gas to sink artificially
to the centre of the cluster.
  We use SPHS to study the contribution of numerical versus physical
dissipation on the entropy core, and argue that numerical dissipation is
required to ensure single-valued fluid quantities in converging flows. However,
provided this dissipation occurs only at the resolution limit, and provided
that it does not propagate errors to larger scales, its effect is benign. There
is no requirement to build `sub-grid' models of unresolved turbulence for
galaxy cluster simulations. We conclude that entropy cores in non-radiative
simulations of galaxy clusters are physical, resulting from entropy generation
in shocked gas during cluster assembly, putting to rest the long-standing
puzzle of cluster entropy cores in AMR simulations versus their apparent
absence in classic SPH simulations.


title: Codimension 2 cycles on products of projective homogeneous surfaces

abstract:
  In the present paper, we provide general bounds for the torsion in the
codimension 2 Chow groups of the products of projective homogeneous surfaces.
In particular, we determine the torsion for the product of four Pfister quadric
surfaces and the maximal torsion for the product of three Severi-Brauer
surfaces. We also find an upper bound for the torsion of the product of three
quadric surfaces with the same discriminant.


title:
An active poroelastic model for mechanochemical patterns in protoplasmic
  droplets of Physarum polycephalum

abstract:
  Motivated by recent experimental studies, we derive and analyze a
twodimensional model for the contraction patterns observed in protoplasmic
droplets of Physarum polycephalum. The model couples a model of an active
poroelastic two-phase medium with equations describing the spatiotemporal
dynamics of the intracellular free calcium concentration. The poroelastic
medium is assumed to consist of an active viscoelastic solid representing the
cytoskeleton and a viscous fluid describing the cytosol. The model equations
for the poroelastic medium are obtained from continuum force-balance equations
that include the relevant mechanical fields and an incompressibility relation
for the two-phase medium. The reaction-diffusion equations for the calcium
dynamics in the protoplasm of Physarum are extended by advective transport due
to the flow of the cytosol generated by mechanical stresses. Moreover, we
assume that the active tension in the solid cytoskeleton is regulated by the
calcium concentration in the fluid phase at the same location, which introduces
a chemomechanical feedback. A linear stability analysis of the homogeneous
state without deformation and cytosolic flows exhibits an oscillatory Turing
instability for a large enough mechanochemical coupling strength. Numerical
simulations of the model equations reproduce a large variety of wave patterns,
including traveling and standing waves, turbulent patterns, rotating spirals
and antiphase oscillations in line with experimental observations of
contraction patterns in the protoplasmic droplets.


title:
Rayleigh-Brillouin scattering profiles of air at different temperatures
  and pressures

abstract:
  Rayleigh Brillouin (RB) scattering profiles for air have been recorded for
the temperature range from 255 to 340 K and the pressure range from 640 to 3300
mbar, covering the conditions relevant for the Earth's atmosphere and for
planned atmospheric light detection and ranging (LIDAR) missions. The
measurements performed at a wavelength of 366.8 nm detect spontaneous RB
scattering at a 90 degree scattering angle from a sensitive intracavity setup,
delivering scattering profiles at a 1 percent rms noise level or better. The
elusive transport coefficient, the bulk viscosity, is effectively derived by a
comparing the measurements to the model, yielding an increased trend. The
calculated (Tenti S6) line shapes are consistent with experimental data at the
level of 2 percent, meeting the requirements for the future RB scattering LIDAR
missions in the Earth's atmosphere. However, the systematic 2 percent deviation
may imply that the model has a limit to describe the finest details of RB
scattering in air. Finally, it is demonstrated that the RB scattering data in
combination with the Tenti S6 model can be used to retrieve the actual gas
temperatures.


title: Coxeter groups and their quotients arising from cluster algebras

abstract:
  In a recent paper, Barot and Marsh presented an explicit construction of
presentation of a finite Weyl group by any seed of corresponding cluster
algebra, i.e. by any diagram mutation-equivalent to an orientation of a Dynkin
diagram with given Weyl group. Extending their construction to the affine case,
we obtain presentations for all affine Coxeter groups. Furthermore, we
generalize the construction to the settings of diagrams arising from
unpunctured triangulated surfaces and orbifolds, which leads to presentations
of corresponding groups as quotients of numerous distinct Coxeter groups.


title:
A Discrete-Time Clark-Ocone Formula and its Application to an Error
  Analysis

abstract:
  In this paper, we will establish a discrete-time version of
Clark(-Ocone-Haussmann) formula, which can be seen as an asymptotic expansion
in a weak sense. The formula is applied to the estimation of the error caused
by the martingale representation. In the way, we use another distribution
theory with respect to Gaussian rather than Lebesgue measure, which can be seen
as a discrete Malliavin calculus.


title: Arithmetic hom-Lie algebras and L-functions

abstract:
  This note started out as a letter to J\"urgen Ritter and is brief attempt to
entice some number theorists to study hom-Lie algebras.


title:
Controllable directive radiation of a magnetic dipole above planar metal
  surface

abstract:
  We report unidirectional radiation of a magnetic dipole above planar metal
surface, the radiation direction can be manipulated via changing the distance
between the dipole and the surface. This phenomenon is unique for the
combination of magnetic dipole and metal surface and does not happen for linear
polarized dipole on metal surface or magnetic dipole on dielectric surface. The
underlining physics is analytically disclosed by the interference of two
orthogonally-oriented dipole component with \pi/2 phase lag. A substantially
different mechanism of introducing the vectorial nature of the dipole itself to
control light emission distinguishes the present scheme from nanoantenna and
provides a new degree of freedom in light emission engineering.


title:
Ice quivers with potentials associated with triangulations and
  Cohen-Macaulay modules over orders

abstract:
  Given a triangulation of a polygon P with n vertices, we associate an ice
quiver with potential such that the associated Jacobian algebra has the
structure of a Gorenstein tiled K[x]-order L. Then we show that the stable
category of the category of Cohen-Macaulay L-modules is equivalent to the
cluster category C of Dynkin type A(n-3).
  It gives a natural interpretation of the usual indexation of cluster tilting
objects of C by triangulations of P. Moreover, it extends naturally the
triangulated categorification by C of the cluster algebra of type A(n-3) to an
exact categorification by adding coefficients corresponding to the sides of P.
Finally, we lift the previous equivalence of categories to an equivalence
between the stable category of graded Cohen-Macaulay L-modules and the bounded
derived category of modules over a quiver of type A(n-3).


title:
Spatially resolved atomic and molecular emission from the very low-mass
  star IRS54

abstract:
  Molecular outflows from very low-mass stars (VLMSs) and brown dwarfs (BDs)
have been studied very little, and only a few objects have been directly
imaged. Using VLT SINFONI K-band observations, we spatially resolved, for the
first time, the H2 emission around IRS54, a ~0.1-0.2 Msun Class I source. The
molecular emission shows a complex structure delineating a large outflow cavity
and an asymmetric molecular jet. In addition, new [FeII] VLT ISAAC observations
at 1.644um allowed us to discover the atomic jet counterpart which extends down
to the central source. The outflow structure is similar to those found in
low-mass Class I young stellar objects (YSOs) and Classical TTauri stars
(CTTSs). However, its Lacc/Lbol ratio is very high (~80%), and the derived mass
accretion rate is about one order of magnitude higher than in objects with
similar mass, pointing to the young nature of the investigated source.


title:
The ESO UVES Advanced Data Products Quasar Sample - I. Dataset and New
  N_HI Measurements of Damped Absorbers

abstract:
  We present here a dataset of quasars observed with the Ultraviolet Visual
Echelle Spectrograph (UVES) on the VLT and available in the ESO UVES Advanced
Data Products archive. The sample is made up of a total of 250 high resolution
quasar spectra with emission redshifts ranging from 0.191 < z_em <6.311. The
total UVES exposure time of this dataset is 1560 hours. Thanks to the high
resolution of UVES spectra, it is possible to unambiguously measure the column
density of absorbers with damping wings, down to N_HI > 10^{19} cm^{-2}, which
constitutes the sub-damped Lya absorber (sub-DLA) threshold. Within the
wavelength coverage of our UVES data, we find 150 damped Lya systems
(DLAs)/sub-DLAs in the range 1.5 < z_abs < 4.7. Of these 150, 93 are DLAs and
57 are sub-DLAs. An extensive search in the literature indicates that 6 of
these DLAs and 13 of these sub-DLAs have their N_HI measured for the first
time. Among them, 10 are new identifications as DLAs/sub-DLAs. For each of
these systems, we obtain an accurate measurement of the HI column density and
the absorber's redshift in the range 1.7 < z_abs < 4.2 by implementing a Voigt
profile-fitting algorithm. These absorbers are further confirmed thanks to the
detection of associated metal lines and/or lines from members of the Lyman
series. In our data, a few quasars' lines-of-sight are rich. An interesting
example is towards QSO J0133+0400 (z_em = 4.154) with six DLAs and sub-DLAs
reported.


title: Unfolding for CHR programs

abstract:
  Program transformation is an appealing technique which allows to improve
run-time efficiency, space-consumption, and more generally to optimize a given
program. Essentially, it consists of a sequence of syntactic program
manipulations which preserves some kind of semantic equivalence. Unfolding is
one of the basic operations which is used by most program transformation
systems and which consists in the replacement of a procedure call by its
definition. While there is a large body of literature on transformation and
unfolding of sequential programs, very few papers have addressed this issue for
concurrent languages.
  This paper defines an unfolding system for CHR programs. We define an
unfolding rule, show its correctness and discuss some conditions which can be
used to delete an unfolded rule while preserving the program meaning. We also
prove that, under some suitable conditions, confluence and termination are
preserved by the above transformation.
  To appear in Theory and Practice of Logic Programming (TPLP)


title: Approximating the mean of a truncated normal distribution

abstract:
  A non trivial problem that arises in several applications is the estimation
of the mean of a truncated normal distribution. In this paper, an iterative
deterministic scheme for approximating this mean is proposed. It has been
inspired from an iterative Markov chain Monte Carlo (MCMC) scheme that
addresses this problem and it can be viewed as a generalization of a recently
proposed relevant model. Conditions are provided under which it is proved that
the scheme converges to a unique fixed point. Finally, the theoretical results
are also supported by computer simulations, which also show the rapid
convergence of the method to a solution vector that is very close to the mean
of the truncated normal distribution under study.


title:
Determination of quark-hadron transition from lattice QCD and
  neutron-star observation

abstract:
  We determine the quark-hadron transition line in the whole region of
temperature (T) and baryon-number chemical potential (\mu_B) from lattice QCD
results and neutron-star mass measurements, making the quark-hadron hybrid
model that is consistent with the two solid constraints. The quark part of the
hybrid model is the Polyakov-loop extended Nambu-Jona-Lasinio (PNJL) model with
entanglement vertex that reproduces lattice QCD results at mu_B/T=0, while the
hadron part is the hadron resonance gas model with volume-exclusion effect that
reproduces neutron-star mass measurements and the neutron-matter equation of
state calculated from two- and three-nucleon forces based on the chiral
effective field theory. The lower bound of the critical mu_B of the
quark-hadron transition at zero T is mu_B = 1.6 GeV. The interplay between the
heavy-ion collision physics around mu_B/T =6 and the neutron-star physics where
mu_B/T is infinity is discussed.


title: On non-equilibrium photon distributions in the Casimir effect

abstract:
  The electromagnetic field in a typical geometry of the Casimir effect is
described in the Schwinger-Keldysh formalism. The main result is the photon
distribution function (Keldysh Green function) in any stationary state of the
field. A two-plate geometry with a sliding interface in local equilibrium is
studied in detail, and full agreement with the results of Rytov fluctuation
electrodynamics is found. As an illustration, plots are shown for a spectrum of
the energy density between the plates.


title:
Eulerian simulations of collisional effects on electrostatic plasma
  waves

abstract:
  The problem of collisions in a plasma is a wide subject with a huge
historical literature. In fact, the description of realistic plasmas is a tough
problem to attach, both from the theoretical and the numerical point of view,
and which requires in general to approximate the original collisional Landau
integral by simplified differential operators in reduced dimensionality. In
this paper, a Eulerian time-splitting algorithm for the study of the
propagation of electrostatic waves in collisional plasmas is presented.
Collisions are modeled through one-dimensional operators of the Fokker-Planck
type, both in linear and nonlinear form. The accuracy of the numerical code is
discussed by comparing the numerical results to the analytical predictions
obtained in some limit cases when trying to evaluate the effects of collisions
in the phenomenon of wave plasma echo and collisional dissipation of
Bernstein-Greene-Kruskal waves. Particular attention is devoted to the study of
the nonlinear Dougherty collisional operator, recently used to describe the
collisional dissipation of electron plasma waves in a pure electron plasma
column. A receipt to prevent the filamentation problem in Eulerian algorithms
is provided by exploiting the property of velocity diffusion operators to
smooth out small velocity scales.


title: Assessing Financial Model Risk

abstract:
  Model risk has a huge impact on any risk measurement procedure and its
quantification is therefore a crucial step. In this paper, we introduce three
quantitative measures of model risk when choosing a particular reference model
within a given class: the absolute measure of model risk, the relative measure
of model risk and the local measure of model risk. Each of the measures has a
specific purpose and so allows for flexibility. We illustrate the various
notions by studying some relevant examples, so as to emphasize the
practicability and tractability of our approach.


title:
Achievable Degrees of Freedom Region of the MIMO Relay Networks using
  the Detour Schemes

abstract:
  In this paper, we study the degrees of freedom (DoF) of the MIMO relay
networks. We start with a general Y channel, where each user has $M_i$ antennas
and aims to exchange messages with the other two users via a relay equipped
with $N$ antennas. Then, we extend our work to a general 4-user MIMO relay
network. Unlike most previous work which focused on the total DoF of the
network, our aim here is to characterize the achievable DoF region as well. We
develop an outer bound on the DoF region based on the notion of one sided
genie. Then, we define a new achievable region using the Signal Space Alignment
(SSA) and the Detour Schemes. Our achievable scheme achieves the upper bound
for certain conditions relating $M_i$'s and $N$.


title: Quantum liquids resulted from the models with four-fermion interaction

abstract:
  A (nearly) perfect liquid discovered in the experements with
ultrarelativistic heavy ion collisions is investigated by studying the quark
ensembles with four-fermion interection as a fundamental theoretical approach.
The comparative analysis of several quantum liquid models is performed and it
results in the conclusion that the presence of gas---liquid phase transition is
their characteristic feature. The problem of instability of the quark droplets
of small quark number is discussed and argued to be rooted in the chiral
soliton formation. An existence of mixed phase of the vacuum and baryon matter
is proposed as a possible reason of the latter stability.


title: Security for Smart Mobile Networks: The NEMESYS Approach

abstract:
  The growing popularity of smart mobile devices such as smartphones and
tablets has made them an attractive target for cyber-criminals, resulting in a
rapidly growing and evolving mobile threat as attackers experiment with new
business models by targeting mobile users. With the emergence of the first
large-scale mobile botnets, the core network has also become vulnerable to
distributed denial-of-service attacks such as the signaling attack.
Furthermore, complementary access methods such as Wi-Fi and femtocells
introduce additional vulnerabilities for the mobile users as well as the core
network. In this paper, we present the NEMESYS approach to smart mobile network
security. The goal of the NEMESYS project is to develop novel security
technologies for seamless service provisioning in the smart mobile ecosystem,
and to improve mobile network security through a better understanding of the
threat landscape. To this purpose, NEMESYS will collect and analyze information
about the nature of cyber-attacks targeting smart mobile devices and the core
network so that appropriate counter-measures can be taken. We are developing a
data collection infrastructure that incorporates virtualized mobile honeypots
and honeyclients in order to gather, detect and provide early warning of mobile
attacks and understand the modus operandi of cyber-criminals that target mobile
devices. By correlating the extracted information with known attack patterns
from wireline networks, we plan to reveal and identify the possible shift in
the way that cyber-criminals launch attacks against smart mobile devices.


title: Core-collapse Supernovae and Gamma-ray Bursts in TMT Era

abstract:
  Study of energetic cosmic explosions as a part of time domain astronomy is
one of the key areas that could be pursued with upcoming Giant segmented
optical-IR telescopes with a very large photon collecting area applying cutting
edge technology. Existing 8-10m class telescopes have been helpful to improve
our knowledge about Core-Collapse Supernovae, Gamma-ray Bursts and nature of
their progenitors and explosion mechanisms. However, many aspects about these
energetic cosmic explosions are still not well-understood and require much
bigger telescopes and back-end instruments with high precision to address the
evolution of massive stars and high-redshift Universe in more detail. In this
presentation, possible thrust research areas towards Core-Collapse Supernovae
and Gamma-ray Bursts with the Thirty Meter Telescope and back-end instruments
are presented.


title: Polyestimate: instantaneous open source surface code analysis

abstract:
  The surface code is highly practical, enabling arbitrarily reliable quantum
computation given a 2-D nearest-neighbor coupled array of qubits with gate
error rates below approximately 1%. We describe an open source library,
Polyestimate, enabling a user with no knowledge of the surface code to specify
realistic physical quantum gate error models and obtain logical error rate
estimates. Functions allowing the user to specify simple depolarizing error
rates for each gate have also been included. Every effort has been made to make
this library user-friendly.


title:
The density of states of graphene underneath a metal electrode and its
  correlation with the contact resistivity

abstract:
  The density of states (DOS) of graphene underneath a metal is estimated
through a quantum capacitance measurement of the metal/graphene/SiO2/n+-Si
contact structure fabricated by a resist-free metal deposition process.
Graphene underneath Au maintains a linear DOS - energy relationship except near
the Dirac point, whereas the DOS of graphene underneath Ni is broken and
largely enhanced around the Dirac point, resulting in only a slight modulation
of the Fermi energy. Moreover, the DOS of graphene in the contact structure is
correlated with the contact resistivity measured using devices fabricated by
the resist-free process.


title: Energy ordering of grain boundaries in Cr2O3: Insights from theory

abstract:
  The grain boundaries, GBs, of corundum Cr2O3 are known to play an important
role in the diffusion of ions within the oxide, which is an important
phenomenon for the corrosion of the stainless steels. The extent of the growth
of oxide layers in stainless steel depends upon which interfaces are preferred
within Cr2O3. Therefore, we have constructed four different grain boundary
planes (rhombohedral, basal, prismatic and pyramidal) and their various
associated interface symmetries known in literature for corundum Al2O3. Their
structural, electronic, and energetic properties are investigated theoretically
with periodic calculations using the DFT+U approach. We find that the prismatic
screw GB with a Cr-O plane interface is the energetically preferred GB with the
rhombohedral GB with screw symmetry and Cr vacancy termination being the second
energetically preferred GB. The increase of the number of in-plane Cr atoms at
the interface of prismatic GB enhances the stability which is also evident in
the electronic density of states.


title:
Interbasis expansions for the isotropic 3D harmonic oscillator and
  bivariate Krawtchouk polynomials

abstract:
  An explicit expression for the general bivariate Krawtchouk polynomials is
obtained in terms of the standard Krawtchouk and dual Hahn polynomials. The
bivariate Krawtchouk polynomials occur as matrix elements of the unitary
reducible representations of SO(3) on the energy eigenspaces of the
3-dimensional isotropic harmonic oscillator and the explicit formula is
obtained from the decomposition of these representations into their irreducible
components. The decomposition entails expanding the Cartesian basis states in
the spherical bases that span irreducible SO(3) representations. The overlap
coefficients are obtained from the Clebsch-Gordan problem for the su(1,1) Lie
algebra.


title: On some classes of partial difference equations

abstract:
  In one of his work, appeared in 1969, John A. Baker initiated the systematic
investigation of some partial difference equations. The main purpose of this
paper is to continue and to extend these investigations. Firstly, we present
how such type of equations can be classified into elliptic, parabolic and
hyperbolic subclasses, respectively. After that, we show solution methods in
the elliptic class. Here we will deal in details with the discrete version of
the following partial differential equations: Laplace's equation, Poisson
equation and the (in)homogeneous biharmonic equation.


title: On the theory of quantum measurement

abstract:
  The notion of state reduction employed by the standard quantum theory of
measurement is difficult to accept for two reasons: It leaves open where and
when the reduction takes place and it does not give any objective conditions
under which the reduction occurs. Some recently published ideas on this problem
are developed an improved. The disturbance of measurement due to identical
particles in the environment is shown to make any POV measure non-measurable.
Truncated POV (TPOV) measures are introduced that can be measurable if object
systems satisfy the additional requirement of having separation status. The
separation status is generalised from domain of space to domain of phase space.
Starting from the previously introduced distinction between ancillas and
detectors, further study of experiments suggests that a thermodynamic mixing
within a detector and the consequent loss of separation status is the objective
condition for the occurrence of the state reduction. The conjecture is simple,
specific and testable. The theory is illustrated by a model of a real
measurement.


title:
Crossover from tumbling to tank-treading-like motion in dense simulated
  suspensions of red blood cells

abstract:
  Via computer simulations, we provide evidence that the shear rate induced red
blood cell tumbling-to-tank-treading transition also occurs at quite high
volume fractions, where collective effects are important. The transition takes
place as the ratio of suspension stress to the characteristic cell membrane
stress exceeds a certain value, independent of volume fraction and cell
deformability. This value coincides with that for a transition from an
orientationally less ordered to a highly ordered phase. The average cell
deformation does not show any signature of the transition, but rather follows a
simple scaling law independent of volume fraction.


title:
Initial conditions for inflation and the energy scale of SUSY-breaking
  from the (nearly) gaussian sky

abstract:
  We show how general initial conditions for small field inflation can be
obtained in multi-field models. This is provided by non-linear angular friction
terms in the inflaton that provide a phase of non-slow-roll inflation before
the slow-roll inflation phase. This in turn provides a natural mechanism to
star small-field slow-roll at nearly zero velocity for arbitrary initial
conditions. We also show that there is a relation between the scale of SUSY
breaking sqrt (f) and the amount of non-gaussian fluctuations generated by the
inflaton. In particular, we show that in the local non-gaussian shape there
exists the relation sqrt (f) = 10^{13} GeV sqrt (f_NL). With current
observational limits from Planck, and adopting the minimum amount of
non-gaussian fluctuations allowed by single-field inflation, this provides a
very tight constraint for the SUSY breaking energy scale sqrt (f) = 3-7 x
10^{13} GeV at 95% confidence. Further limits, or detection, from next year's
Planck polarisation data will further tighten this constraint by a factor of
two. We highlight that the key to our approach is to identify the inflaton with
the scalar component of the goldstino superfield. This superfield is universal
and implements the dynamics of SUSY breaking as well as superconformal
breaking.


title: Design and Commissioning of the LWA1 Radio Telescope

abstract:
  LWA1 is a new large radio telescope array operating in the frequency range
10-88 MHz, located in central New Mexico. The telescope consists of 260 pairs
of dipole-type antennas whose outputs are individually digitized and formed
into beams. Simultaneously, signals from all dipoles can be recorded using one
of the telescope's "all dipoles" modes, facilitating all-sky imaging. Notable
features of the instrument include four independently-steerable beams utilizing
digital "true time delay" beamforming, high intrinsic sensitivity (about 6 kJy
zenith system equivalent flux density), large instantaneous bandwidth (up to 78
MHz), and large field of view (about 3-10 degrees, depending on frequency and
zenith angle of pointing). This paper summarizes the design of LWA1, its
performance as determined in commissioning experiments, and results from early
science observations demonstrating the capabilities of the instrument.


title:
On character sheaves and characters of reductive groups at unipotent
  classes

abstract:
  With a view to determining character values of finite reductive groups at
unipotent elements, we prove a number of results concerning inner products of
generalised Gelfand-Graev characters with characteristic functions of character
sheaves, here called Lusztig functions. These are used to determine projections
of generalised Gelfand-Graev characters to the space of unipo- tent characters,
and to the space of characters with a given wave front set. Such projections
are expressed largely in terms of Weyl group data. We show how the values of
characters at their unipotent support or wave front set are determined by such
data. In some exceptional groups we show that the projection of a generalised
Gelfand-Graev character to a family with the same wave front set is (up to
sign) the dual of a Mellin transform. Using these results, in certain cases we
are able to determine roots of unity which relate almost characters to the
characteristic functions. In particular we show how to compute the values of
all unipotent characters at all unipotent classes for the exceptional adjoint
groups of type G2, F4, E6, E7 and E8. We also pro- vide an appendix which gives
a complete list of the cuspidal character sheaves on all quasi-simple groups.


title: Proton spin in leading order of the covariant approach

abstract:
  We study the covariant version of the quark-parton model, in which the
general rules of the angular momentum composition are accurately taken into
account. We demonstrate how these rules affect the relativistic interplay
between the quark spins and orbital angular momenta, which collectively
contribute to the proton spin. The spin structure functions $g_{1}$ and $g_{2}$
corresponding to the many-quark state $J=1/2$ are studied and it is shown they
satisfy constraints and relations well compatible with the available
experimental data including proton spin content $\Delta\Sigma\lesssim1/3$. The
suggested Lorentz invariant 3D approach for calculation of the structure
functions is compared with the approach based on the conventional collinear
parton model.


title: Model of hard spheroplatelets near a hard wall

abstract:
  A system of hard spheroplatelets near an impenetrable wall is studied in the
low-density Onsager approximation. Spheroplatelets have optimal shape between
rods and plates, and the direct transition from the isotropic to biaxial
nematic phase is present. A simple local approximation for the one-particle
distribution function is used. Analytical results for the surface tension and
the entropy contributions are derived. The density and the order-parameter
profiles near the wall are calculated. The preferred orientation of the short
molecule axes is perpendicular to the wall. Biaxiality close to the wall can
appear only if the phase is biaxial in the bulk.


title: QCD resummation in hadron production

abstract:
  We present calculations of next-to-leading order and resummed QCD corrections
for semi-inclusive deep-inelastic scattering and single-inclusive e+e-
annihilation. The resummation is performed to next-to-leading logarithmic
accuracy. Knowing these QCD corrections is important in order to extract parton
distribution functions and fragmentation functions from present and future data
for these reactions. We present comparisons of our results to recent data by
the COMPASS, HERMES, Belle, and BaBar experiments.


title: A minimal model for acoustic forces on Brownian particles

abstract:
  We present a generalization of the inertial coupling (IC) [Usabiaga et al. J.
Comp. Phys. 2013] which permits the resolution of radiation forces on small
particles with arbitrary acoustic contrast factor. The IC method is based on a
Eulerian-Lagrangian approach: particles move in continuum space while the fluid
equations are solved in a regular mesh (here we use the finite volume method).
Thermal fluctuations in the fluid stress, important below the micron scale, are
also taken into account following the Landau-Lifshitz fluid description. Each
particle is described by a minimal cost resolution which consists on a single
small kernel (bell-shaped function) concomitant to the particle. The main role
of the particle kernel is to interpolate fluid properties and spread particle
forces. Here, we extend the kernel functionality to allow for an arbitrary
particle compressibility. The particle-fluid force is obtained from an imposed
no-slip constraint which enforces similar particle and kernel fluid velocities.
This coupling is instantaneous and permits to capture the fast, non-linear
effects underlying the radiation forces on particles. Acoustic forces arise
either because an excess in particle compressibility (monopolar term) or in
mass (dipolar contribution) over the fluid values. Comparison with theoretical
expressions show that the present generalization of the IC method correctly
reproduces both contributions. Due to its low computational cost, the present
method allows for simulations with many particles using a standard Graphical
Processor Unit (GPU).


title: Thick points for a Gaussian Free Field in 4 dimensions

abstract:
  This article is concerned with the study of the fractal dimension of thick
points for a 4-dimensional Gaussian Free Field. We adopt the definition of
Gaussian Free Field on $\R^4$ introduced by Chen and Jakobson (2012) viewed as
an abstract Wiener space with underlying Hilbert space $H^2(\R^4)$. We can
prove that for $0\leq a \leq 4$ the Hausdorff dimension of the set of $a$-high
points is $4-a$. We also show that the set of thick points gives full mass to
the 4-dimensional Liouville Quantum Gravity measure.


title: Nonequilibrium glassy dynamics of self-propelled hard disks

abstract:
  We analyse the collective dynamics of self-propelled particles in the large
density regime where passive particles undergo a kinetic arrest to an amorphous
glassy state. We capture the competition between self-propulsion and crowding
effects using a two-dimensional model of self-propelled hard disks, which we
study using Monte-Carlo simulations. Although the activity drives the system
far from equilibrium, self-propelled particles undergo a kinetic arrest, which
we characterize in detail and compare with its equilibrium counterpart. In
particular, the critical density for dynamic arrest continuously shifts to
larger density with increasing activity, and the relaxation time is
surprisingly well described by an algebraic divergence resulting from the
emergence of highly collective dynamics. These results show that dense
assemblies of active particles undergo a nonequilibrium glass transition which
is profoundly affected by self-propulsion mechanisms.


title: QCD corrections to H -> gg in FDR

abstract:
  I apply FDR -- a recently introduced Four Dimensional Regularization approach
to quantum field theories -- to compute the NLO QCD corrections to H -> gg in
the large top mass limit. The calculation involves all key ingredients of
massless QCD, namely ultraviolet, infrared and collinear divergences, besides
alpha_s renormalization. I show in detail how the correct result emerges in
FDR, and discuss the translation rules to dimensional regularization.


title: Trigger and Data Acquisition for hadron colliders at the Energy Frontier

abstract:
  The LHC trigger and data acquisition systems will need significant
modifications to operate at the HL-LHC. Due to the increased occupancy of each
crossing, Level-1 trigger systems would experience degraded performance of the
LHC algorithms presently selecting up to 100 kHz of crossings from the LHC
input rate of 40 MHz. The DAQ systems will experience larger event sizes due to
greater occupancy and higher channel counts of new detectors. This paper
summarizes findings and recommendations to upgrade the LHC experiments trigger
and data acquisition systems for operation at the HL-HLC.


title: Revisiting additivity violation of quantum channels

abstract:
  We prove additivity violation of minimum output entropy of quantum channels
by straightforward application of \epsilon-net argument and L\'evy's lemma. The
additivity conjecture was disproved initially by Hastings. Later, a proof via
asymptotic geometric analysis was presented by Aubrun, Szarek and Werner, which
uses Dudley's bound on Gaussian process (or Dvoretzky's theorem with
Schechtman's improvement). In this paper, we develop another proof along
Dvoretzky's theorem in Milman's view showing additivity violation in broader
regimes than the existing proofs. Importantly, Dvoretzky's theorem works well
with norms to give strong statements but these techniques can be extended to
functions which have norm-like structures - positive homogeneity and triangle
inequality. Then, a connection between Hastings' method and ours is also
discussed. Besides, we make some comments on relations between regularized
minimum output entropy and classical capacity of quantum channels.


title: The Higgs field as an inflaton

abstract:
  The Higgs field of the pure Standard Model can lead to the inflationary
expansion of the early Universe if it is non-minimally coupled to gravity. The
model predicts Cosmic Microwave Background (CMB) parameters in perfect
agreement with the current observations and has implications for the Higgs
boson mass. We review the model, its predictions, problems arising with its
quantization and some closely related models.


title:
Discovering a 5.72 Day Period in the Supergiant Fast X-ray Transient AX
  J1845.0-0433

abstract:
  Temporal analysis of INTEGRAL/IBIS data has revealed a 5.7195\pm0.0007 day
periodicity in the supergiant fast X-ray transient (SFXT) source AX
J1845.0-0433, which we interpret as the orbital period of the system. The
new-found knowledge of the orbital period is utilised to investigate the
geometry of the system by means of estimating an upper limit for the size of
the supergiant (<27 R_{\sun}) as well as the eccentricity of the orbit
(\epsilon<0.37).


title:
Solving the Strong CP Problem with Discrete Symmetries and the Right
  Unitarity Triangle

abstract:
  We present a solution to the strong CP problem based on spontaneous CP
violation and discrete family symmetries. The model predicts in a natural way
the almost right-angled quark unitarity triangle angle ($\alpha \simeq
90^\circ$) by making the entries of the quark mass matrices either real or
imaginary. By this choice the determinants of the mass matrices are rendered
real and hence the strong CP phase vanishes. We present a toy model for the
quark sector that demonstrates the viability of our approach.


title: Towards realistic models of quark masses with geometrical CP violation

abstract:
  We present a model for quark masses and mixing, featuring geometrical CP
violation through a \Delta(27) triplet. By employing a single U(1)_F or Z_N
symmetry in addition to \Delta(27), we forbid all terms in the scalar potential
that would spoil the calculable phases the triple acquires. The quark sector is
realised by mimicking an existing scheme that reproduces the masses and CKM
mixing, with the extra symmetry enabling the hierarchies in the Yukawa
couplings through a Froggatt-Nielsen mechanism.


title: The Interstellar Medium White Paper

abstract:
  The interstellar medium is the engine room for galactic evolution. While much
is known about the conditions within the ISM, many important areas regarding
the formation and evolution of the various phases of the ISM leading to star
formation, and its role in important astrophysical processes, remain to be
explained. This paper discusses several of the fundamental science problems,
placing them in context with current activities and capabilities, as well as
the future capabilities that are needed to progress them in the decade ahead.
Australia has a vibrant research community working on the interstellar medium.
This discussion gives particular emphasis to Australian involvement in
furthering their work, as part of the wider international endeavour.
  The particular science programs that are outlined in this White Paper include
the formation of molecular clouds, the ISM of the Galactic nucleus, the origin
of gamma-rays and cosmic rays, high mass star and cluster formation, the dense
molecular medium, galaxy evolution and the diffuse atomic medium, supernova
remnants, the role of magnetism and turbulence in the Galactic ecology and
complex organic molecules in space.


title:
Migration and gas accretion scenarios for the Kepler 16, 34 and 35
  circumbinary planets

abstract:
  Several circumbinary planets have been detected by the Kepler mission. Recent
work has emphasized the difficulty of forming these planets at their observed
locations. It has been suggested that these planets formed further out in their
discs and migrated in to locations where they are observed. We examine the
orbital evolution of planets embedded in circumbinary disc models for the three
systems Kepler-16, Kepler-34 and Kepler-35. The aims are: to explore the
plausibility of a formation scenario in which cores form at large distances
from the binaries and undergo inward migration and gas accretion as the gas
disc disperses; to determine which sets of disc parameters lead to planets
whose final orbits provide reasonable fits to the observed systems. We
performed simulations of a close binary system interacting with circumbinary
discs with differing aspect ratios, and viscous stress parameters. Once the
binary+disc system reaches quasi-equilibrium we embed a planet in the disc and
examine its evolution under the action of binary and disc forces. We consider
fully-formed planets with masses equal to those inferred from Kepler data, and
low-mass cores that migrate and accrete gas while the gas disc is being
dispersed. A typical outcome for all systems is stalling of inward migration as
the planet enters the inner cavity formed by the binary system. The
circumbinary disc becomes eccentric and the disc eccentricity forces the planet
into a noncircular orbit. For each of the Kepler-16b, Kepler-34b and Kepler-35b
systems we obtain planets whose parameters agree reasonably well with the
observational data. The simulations presented here provide support for a
formation scenario in which a core forms, migrates inward and accretes gas, but
accurate fitting of the observed Kepler systems is likely to require disc
models that are significantly more sophisticated in terms of their input
physics.


title:
Muon tomography imaging algorithms for nuclear threat detection inside
  large volume containers with the Muon Portal detector

abstract:
  Muon tomographic visualization techniques try to reconstruct a 3D image as
close as possible to the real localization of the objects being probed.
Statistical algorithms under test for the reconstruction of muon tomographic
images in the Muon Portal Project are here discussed. Autocorrelation analysis
and clustering algorithms have been employed within the context of methods
based on the Point Of Closest Approach (POCA) reconstruction tool. An iterative
method based on the log-likelihood approach was also implemented. Relative
merits of all such methods are discussed, with reference to full Geant4
simulations of different scenarios, incorporating medium and high-Z objects
inside a container.


title:
Effect of magnesium ions on dielectric relaxation in semidilute DNA
  aqueous solutions

abstract:
  The effect of magnesium ion Mg2+ on the dielectric relaxation of semidilute
DNA aqueous solutions has been studied by means of dielectric spectroscopy in
the 100 Hz-100 MHz frequency range. De Gennes-Pfeuty-Dobrynin semidilute
solution correlation length is the pertinent fundamental length scale for
sufficiently low concentration of added salt, describing the collective
properties of Mg-DNA solutions. No relaxation fingerprint of the DNA
denaturation bubbles, leading to exposed hydrophobic core scaling, was detected
at low DNA concentrations, thus indicating an increased stability of the
double-stranded conformation in Mg-DNA solutions as compared to the case of
Na-DNA solutions. Some changes are detected in the behavior of the fundamental
length scale pertaining to the single molecule DNA properties, reflecting
modified electrostatic screening effects of the Odijk-Skolnick-Fixman type. All
results consistently demonstrate that Mg2+ ions interact with DNA in a similar
way as Na1+ ions do, their effect being mostly describable through an enhanced
screening.


title: On gapped phases with a continuous symmetry and boundary operators

abstract:
  We discuss the role of compact symmetry groups, G, in the classification of
gapped ground state phases of quantum spin systems. We consider two
representations of G on infinite subsystems. First, in arbitrary dimensions, we
show that the ground state spaces of models within the same G-symmetric phase
carry equivalent representations of the group for each finite or infinite
sublattice on which they can be defined and on which they remain gapped. This
includes infinite systems with boundaries or with non-trivial topologies.
Second, for two classes of one-dimensional models, by two different methods,
for G=SU(2) in one, and G\subset SU(d), in the other we construct explicitly an
`excess spin' operator that implements rotations of half of the infinite chain
on the GNS Hilbert space of the ground state of the full chain. Since this
operator is constructed as the limit of a sequence of observables, the
representation itself is, in principle, experimentally observable. We claim
that the corresponding unitary representation of G is closely related to the
representation found at the boundary of half-infinite chains. We conclude with
determining the precise relation between the two representations for the class
of frustration-free models with matrix product ground states.


title:
Semilinear elliptic equations with measure data and quasi-regular
  Dirichlet forms

abstract:
  We are mainly concerned with equations of the form $-Lu=f(x,u)+\mu$, where
$L$ is an operator associated with a quasi-regular possibly nonsymmetric
Dirichlet form, $f$ satisfies the monotonicity condition and mild integrability
conditions, and $\mu$ is a bounded smooth measure. We prove general results on
existence, uniqueness and regularity of probabilistic solutions, which are
expressed in terms of solutions to backward stochastic differential equations.
Applications include equations with nonsymmetric divergence form operators,
with gradient perturbations of some pseudodifferential operators and equations
with Ornstein-Uhlenbeck type operators in Hilbert spaces. We also briefly
discuss the existence and uniqueness of probabilistic solutions in the case
where $L$ corresponds to a lower bounded semi-Dirichlet form.


title:
Resonances in the Photoionization Cross Sections of Atomic Nitrogen
  Shape the Far-Ultraviolet Spectrum of the Bright Star in 47 Tucanae

abstract:
  The far-ultraviolet (FUV) spectrum of the Bright Star (B8 III) in 47 Tuc (NGC
104) shows a remarkable pattern: it is well fit by LTE models at wavelengths
longer than Lyman beta, but at shorter wavelengths it is fainter than the
models by a factor of two. A spectrum of this star obtained with the Far
Ultraviolet Spectroscopic Explorer (FUSE) shows broad absorption troughs with
sharp edges at 995 and 1010 A and a deep absorption feature at 1072 A, none of
which are predicted by the models. We find that these features are caused by
resonances in the photoionization cross sections of the first and second
excited states of atomic nitrogen (2s$^2$ 2p$^3$ $^2$D$^0$ and $^2$P$^0$).
Using cross sections from the Opacity Project, we can reproduce these features,
but only if we use the cross sections at their full resolution, rather than the
resonance-averaged cross sections usually employed to model stellar
atmospheres. These resonances are strongest in stellar atmospheres with
enhanced nitrogen and depleted carbon abundances, a pattern typical of post-AGB
stars.


title: Lensing simulations by Taylor expansion -- not so inefficient after all

abstract:
  Cosmic Microwave Background lensing simulation by Taylor expansion has long
been considered impractical due to slow convergence, but a recent flat-sky
implementation shows that a simple trick eliminates this problem, making Taylor
lensing a fast and simple lensing algorithm for the flat sky. Here we
generalize the method to the full sky, and study its convergence and
performance relative to a commonly used numerical code, Lenspix, with extensive
benchmarks of both. Compared to the flat sky case, the method takes a speed hit
due to the slow speed of spherical harmonic transforms compared to fast Fourier
transforms, resulting in speeds of 1/3 to 2/3 of Lenspix for similar accuracy.


title: The state complexity of random DFAs

abstract:
  The state complexity of a Deterministic Finite-state automaton (DFA) is the
number of states in its minimal equivalent DFA. We study the state complexity
of random $n$-state DFAs over a $k$-symbol alphabet, drawn uniformly from the
set $[n]^{[n]\times[k]}\times2^{[n]}$ of all such automata. We show that, with
high probability, the latter is $\alpha_k n + O(\sqrt n\log n)$ for a certain
explicit constant $\alpha_k$.


title: The MINOS experiment: results and prospects

abstract:
  The MINOS experiment has used the world's most powerful neutrino beam to make
precision neutrino oscillation measurements. By observing the disappearance of
muon neutrinos, MINOS has made the world's most precise measurement of the
larger neutrino mass splitting, and has measured the neutrino mixing angle
$\theta_{23}$. Using a dedicated antineutrino beam, MINOS has made the first
direct precision measurements of the corresponding antineutrino parameters. A
search for \nue and \nuebar appearance has enabled a measurement of the mixing
angle $\theta_{13}$. A measurement of the neutral-current interaction rate has
confirmed oscillation between three active neutrino flavours. MINOS will
continue as MINOS+ in an upgraded beam with higher energy and intensity,
allowing precision tests of the three-flavour neutrino oscillation picture, in
particular a very sensitive search for the existence of sterile neutrinos.


title: Linear lattice gauge theory

abstract:
  Linear lattice gauge theory is based on link variables that are arbitrary
complex or real $N\times N$ matrices, in distinction to the usual (non-linear)
formulation with unitary or orthogonal matrices. For a large region in
parameter space both formulations belong to the same universality class, such
that the continuum limits of linear and non-linear lattice gauge theory are
identical. We explore if the linear formulation can help to find a
non-perturbative continuum limit formulated in terms of continuum fields.
Linear lattice gauge theory exhibits excitations beyond the gauge fields. In
the linear formulation the running gauge coupling corresponds to the flow of
the minimum of a ``link potential''. This minimum occurs for a nonzero value of
the link variable $l_0$ in the perturbative regime, while $l_0$ vanishes in the
confinement regime. We discuss a flow equation for the scale dependent location
of the minimum $l_0(k)$.


title:
Stringent Restriction from the Growth of Large-Scale Structure on
  Apparent Acceleration in Inhomogeneous Cosmological Models

abstract:
  Probes of cosmic expansion constitute the main basis for arguments to support
or refute a possible apparent acceleration due to different expansion rates in
the universe as described by inhomogeneous cosmological models. We present in
this Letter a separate argument based on results from an analysis of the growth
rate of large-scale structure in the universe as modeled by the inhomogeneous
cosmological models of Szekeres. We use the models with no assumptions of
spherical or axial symmetries. We find that while the Szekeres models can fit
very well the observed expansion history without a $\Lambda$, they fail to
produce the observed late-time suppression in the growth unless $\Lambda$ is
added to the dynamics. A simultaneous fit to the supernova and growth factor
data shows that the cold dark matter model with a cosmological constant
($\Lambda$CDM) provides consistency with the data at a confidence level of
99.65% while the Szekeres model without $\Lambda$ achieves only a 60.46% level.
When the data sets are considered separately, the Szekeres with no $\Lambda$
fits the supernova data as well as the $\Lambda$CDM does, but provides a very
poor fit to the growth data with only 31.31% consistency level compared to
99.99% for the $\Lambda$CDM. This absence of late-time growth suppression in
inhomogeneous models without a $\Lambda$ is consolidated by a physical
explanation.


title: Approximation on Nash sets with monomial singularities

abstract:
  This paper is devoted to the approximation of differentiable semialgebraic
functions by Nash functions. Approximation by Nash functions is known for
semialgebraic functions defined on an affine Nash manifold M, and here we
extend it to functions defined on Nash subsets X of M whose singularities are
monomial. To that end we discuss first "finiteness" and "weak normality" for
such sets X. Namely, we prove that (i) X is the union of finitely many open
subsets, each Nash diffeomorphic to a finite union of coordinate linear
varieties of an affine space and (ii) every function on X which is Nash on
every irreducible component of X extends to a Nash function on M. Then we can
obtain approximation for semialgebraic functions and even for certain
semialgebraic maps on Nash sets with monomial singularities. As a nice
consequence we show that m-dimensional affine Nash manifolds with divisorial
corners which are class k semialgebraically diffeomorphic, for k>m^2, are also
Nash diffeomorphic.


title: Conway and iteration hemirings

abstract:
  Conway hemirings are Conway semirings without a multiplicative unit. We also
define iteration hemirings as Conway hemirings satisfying certain identities
associated with the finite groups. Iteration hemirings are iteration semirings
without a multiplicative unit. We provide an analysis of the relationship
between Conway hemirings and (partial) Conway semirings and describe several
free constructions. In the second part of the paper we define and study
hemimodules of Conway and iteration hemirings, and show their applicability in
the analysis of quantitative aspects of the infinitary behavior of weighted
transition systems. These include discounted and average computations of
weights.


title:
Transport phenomena in helical edge states interferometers. A Green's
  function approach

abstract:
  We analyze the current and the shot-noise of an electron interferometer made
of the helical edge states of a two-dimensional topological insulator within
the framework of non-equilibrium Green's functions formalism. We study in
detail setups with a single and with two quantum point contacts inducing
scattering between the different edge states. We consider processes preserving
the spin as well as the effect of spin-flip scattering. In the case of a single
quantum point contact, a simple test based on the shot-noise measurement is
proposed to quantify the strength of the spin-flip scattering. In the case of
two single point contacts with the additional ingredient of gate voltages
applied within a finite-size region at the top and bottom edges of the sample,
we identify two type of interference processes in the behavior of the currents
and the noise. One of such processes is analogous to that taking place in a
Fabry-P\'erot interferometer, while the second one corresponds to a
configuration similar to a Mach-Zehnder interferometer. In the helical
interferometer these two processes compete.


title: Quantum dissipative effects in graphene-like mirrors

abstract:
  We study quantum dissipative effects due to the accelerated motion of a
single, imperfect, zero-width mirror. It is assumed that the microscopic
degrees of freedom on the mirror are confined to it, like in plasma or graphene
sheets. Therefore, the mirror is described by a vacuum polarization tensor
$\Pi_{\alpha\beta}$ concentrated on a time-dependent surface. Under certain
assumptions about the microscopic model for the mirror, we obtain a rather
general expression for the Euclidean effective action, a functional of the
time-dependent mirror's position, in terms of two invariants that characterize
the tensor $\Pi_{\alpha\beta}$. The final result can be written in terms of the
TE and TM reflection coefficients of the mirror, with qualitatively different
contributions coming from them. We apply that general expression to derive the
imaginary part of the `in-out' effective action, which measures dissipative
effects induced by the mirror's motion, in different models, in particular for
an accelerated graphene sheet.


title: Orthogonality and minimality in the homology of locally finite graphs

abstract:
  Given a finite set $E$, a subset $D\sub E$ (viewed as a function $E\to \F_2$)
is orthogonal to a given subspace $\FF$ of the $\F_2$-vector space of functions
$E\to \F_2$ as soon as $D$ is orthogonal to every $\sub$-minimal element of
$\FF$. This fails in general when $E$ is infinite.
  However, we prove the above statement for the six subspaces $\FF$ of the edge
space of any 3-connected locally finite graph that are relevant to its
homology: the topological, algebraic, and finite cycle and cut spaces. This
solves a problem of [5]


title: Memory and long-range correlations in chess games

abstract:
  In this paper we report the existence of long-range memory in the opening
moves of a chronologically ordered set of chess games using an extensive chess
database. We used two mapping rules to build discrete time series and analyzed
them using two methods for detecting long-range correlations; rescaled range
analysis and detrented fluctuation analysis. We found that long-range memory is
related to the level of the players. When the database is filtered according to
player levels we found differences in the persistence of the different subsets.
For high level players, correlations are stronger at long time scales; whereas
in intermediate and low level players they reach the maximum value at shorter
time scales. This can be interpreted as a signature of the different strategies
used by players with different levels of expertise. These results are robust
against the assignation rules and the method employed in the analysis of the
time series.


title: LCDM Model in f(T) Gravity: Reconstruction, Thermodynamics and Stability

abstract:
  We investigate some cosmological features of the LCDM model in the framework
of the generalized teleparallel theory of gravity f(T) where T denotes the
torsion scalar. Its reconstruction is performed giving rise to an integration
constant Q and other input parameters according to which we point out more
analysis. Thereby, we show that for some values of this constant, the first and
second laws of thermodynamics can be realized in the equilibrium description,
for the universe with the temperature inside the horizon equal to that at the
apparent horizon. Moreover, still within these suitable values of the constant,
we show that the model may be stable using the de Sitter and Power-Law
cosmological solutions.


title:
Evidence for s-channel single top quark production in $p\bar{p}$
  collisions at $\sqrt{s}$ = 1.96 TeV

abstract:
  We present measurements of the cross sections for the two main production
modes of single top quarks in $p\bar{p}$ collisions at $\sqrt{s} = 1.96$ TeV in
the Run II data collected with the D0 detector at the Fermilab Tevatron
Collider, corresponding to an integrated luminosity of 9.7 fb$^{-1}$. The
s-channel cross section is measured to be $\sigma(p\bar{p} \to tb+X) =
1.10^{+0.33}_{-0.31}$ pb with no assumptions on the value of the t-channel
cross section. Similarly, the t-channel cross section is measured to be
$\sigma(p\bar{p} \to tqb+X) = 3.07^{+0.54}_{-0.49}$ pb. We also measure the
$s+t$ combined cross section as $\sigma(p\bar{p} \to tb+X, tqb+X) =
4.11^{+0.60}_{-0.55}$ pb and set a lower limit on the CKM matrix element
$|V_{tb}| > 0.92$ at $95\%$ C.L., assuming $m_t=172.5$ GeV. The probability to
measure a cross section for the s channel at the observed value or higher in
the absence of signal is $1.0\times 10^{-4}$, corresponding to a significance
of 3.7 standard deviations.


title: Can coarse measurements reveal macroscopic quantum effects?

abstract:
  It has recently been conjectured that detecting quantum effects such as
superposition or entanglement for macroscopic systems always requires high
measurement precision. Analyzing an apparent counter-example involving
macroscopic coherent states and Kerr non-linearities, we find that while
measurements with coarse outcomes can be sufficient, the phase control
precision of the necessary non-linear operations has to increase with the size
of the system. This suggests a refined conjecture that either the {\it outcome
precision} or the {\it control precision} of the measurements has to increase
with system size.


title:
$\mathbb ZS_n$-modules and polynomial identities with integer
  coefficients

abstract:
  We show that, like in the case of algebras over fields, the study of
multilinear polynomial identities of unitary rings can be reduced to the study
of proper polynomial identities. In particular, the factors of series of
$\mathbb ZS_n$-submodules in the $\mathbb ZS_n$-modules of multilinear
polynomial functions can be derived by the analog of Young's (or Pieri's) rule
from the factors of series in the corresponding $\mathbb ZS_n$-modules of
proper polynomial functions.
  As an application, we calculate the codimensions and a basis of multilinear
polynomial identities of unitary rings of upper triangular $2\times 2$ matrices
and infinitely generated Grassmann algebras over unitary rings. In addition, we
calculate the factors of series of $\mathbb ZS_n$-submodules for these
algebras.
  Also we establish relations between codimensions of rings and codimensions of
algebras and show that the analog of Amitsur's conjecture holds in all
torsion-free rings, and all torsion-free rings with 1 satisfy the analog of
Regev's conjecture.


title: Theory of the plasma-wave photoresponse of a gated graphene sheet

abstract:
  The photoresponse of graphene has recently received considerable attention.
The main mechanisms yielding a finite dc response to an oscillating radiation
field which have been investigated include responses of photovoltaic,
photo-thermoelectric, and bolometric origin. In this Article we present a fully
analytical theory of a photoresponse mechanism which is based on the excitation
of plasma waves in a gated graphene sheet. By employing the theory of
relativistic hydrodynamics, we demonstrate that plasma-wave photodetection is
substantially influenced by the massless Dirac fermion character of carriers in
graphene and that the efficiency of photodetection can be improved with respect
to that of ordinary parabolic-band electron fluids in semiconductor
heterostructures.


title: Free Spaces over Countable Compact Metric Spaces

abstract:
  We prove that the Lipschitz-free space over a countable compact metric space
is isometric to a dual space and has the metric approximation property.


title: K pi scattering and the K* decay width from lattice QCD

abstract:
  K* mesons and in particular the K*(892) were frequently addressed in lattice
simulations, but always while ignoring that the K*(892) decays strongly. We
present an exploratory extraction of the masses and widths for the K*
resonances by simulating K pi scattering in p-wave with I = 1/2 on the lattice.
The K pi system with total momenta P = 2*pi/L e_z, 2*pi/L (e_x + e_y) and 0,
that allows the extraction of phase shifts at several values of K pi relative
momenta, is studied. A Breit-Wigner fit of the phase renders a K*(892)
resonance mass m^{lat} = 891 +/- 14 MeV and the K*(892) -> K pi coupling
g^{lat} = 5.7 +/- 1.6 compared to the experimental values m^{exp} = 892 MeV and
g^{exp} = 5.72 +/- 0.06, where g parametrizes the K* -> K pi width. When
extracting the phase shift around the K*(1410) and K2*(1430) resonances we take
into account the mixing of p-wave with d-wave and assume that the scattering is
elastic in our simulation. This gives us an estimate of the K*(1410) resonance
mass m^{lat} = 1.33 +/- 0.02 GeV compared to m^{exp} = 1.414 +/- 0.0015 GeV
assuming the experimental K*(1410) -> K pi coupling. We contrast the resonant I
= 1/2 channel with the repulsive non-resonant I = 3/2 channel, where the phase
is found to be negative and small, in agreement with experiment.


title:
The rate of adaptation in large sexual populations with linear
  chromosomes

abstract:
  In large populations, multiple beneficial mutations may be simultaneously
spreading. In asexual populations, these mutations must either arise on the
same background or compete against each other. In sexual populations,
recombination can bring together beneficial alleles from different backgrounds,
but tightly linked alleles may still greatly interfere with each other. We show
for well-mixed populations that when this interference is strong, the genome
can be seen as consisting of many effectively asexual stretches linked
together. The rate at which beneficial alleles fix is thus roughly proportional
to the rate of recombination, and depends only logarithmically on the mutation
supply and the strength of selection. Our scaling arguments also allow to
predict, with reasonable accuracy, the distribution of effects of fixed
mutations when new mutations have broadly-distributed effects. We focus on the
regime in which crossovers occur more frequently than beneficial mutations, as
is likely to be the case for many natural populations.


title: Bogomolov multipliers for some $p$-groups of nilpotency class 2

abstract:
  The Bogomolov multiplier $B_0(G)$ of a finite group $G$ is defined as the
subgroup of the Schur multiplier consisting of the cohomology classes vanishing
after restriction to all abelian subgroups of $G$. The triviality of the
Bogomolov multiplier is an obstruction to Noether's problem. We show that if
$G$ is a central product of $G_1$ and $G_2$, regarding $K_i\leq Z(G_i), i=1,2$,
and $\theta:G_1\to G_2$ is a group homomorphism such that its restriction
$\theta\vert_{K_1}:K_1\to K_2$ is an isomorphism, then the triviality of
$B_0(G_1/K_1), B_0(G_1)$ and $B_0(G_2)$ implies the triviality of $B_0(G)$. We
give a positive answer to Noether's problem for all $2$-generator $p$-groups of
nilpotency class $2$, and for one series of $4$-generator $p$-groups of
nilpotency class $2$ (with the usual requirement for the roots of unity).


title: Local Fractional Calculus: a Review

abstract:
  The purpose of this article is to review the developments related to the
notion of local fractional derivative introduced in 1996. We consider its
definition, properties, implications and possible applications. This involves
the local fractional Taylor expansion, Leibnitz rule, chain rule, etc. Among
applications we consider the local fractional diffusion equation for fractal
time processes and the relation between stress and strain for fractal media.
Finally, we indicate a stochastic version of local fractional differential
equation.


title:
Quantum-induced interactions in the moduli space of degenerate BPS
  domain walls

abstract:
  In this paper quantum effects are investigated in a very special two-scalar
field model having a moduli space of BPS topological defects. In a
$(1+1)$-dimensional space-time the defects are classically degenerate in mass
kinks, but in $(3+1)$ dimensions the kinks become BPS domain walls, all of them
sharing the same surface tension at the classical level. The heat kernel/zeta
function regularization method will be used to control the divergences induced
by the quantum kink and domain wall fluctuations. A generalization of the
Gilkey-DeWitt-Avramidi heat kernel expansion will be developed in order to
accommodate the infrared divergences due to zero modes in the spectra of the
second-order kink and domain wall fluctuation operators, which are respectively
$N\times N$ matrix ordinary or partial differential operators. Use of these
tools in the spectral zeta function associated with the Hessian operators paves
the way to obtain general formulas for the one-loop kink mass and domain wall
tension shifts in any $(1+1)$- or $(3+1)$-dimensional $N$-component scalar
field theory model. Application of these formulae to the BPS kinks or domain
walls of the $N=2$ model mentioned above reveals the breaking of the classical
mass or surface tension degeneracy at the quantum level. Because the main
parameter distinguishing each member in the BPS kink or domain wall moduli
space is essentially the distance between the centers of two basic kinks or
walls, the breaking of the degeneracy amounts to the surge in quantum-induced
forces between the two constituent topological defects. The differences in
surface tension induced by one-loop fluctuations of BPS walls give rise mainly
to attractive forces between the constituent walls except if the two basic
walls are very far apart. Repulsive forces between two close walls only arise
if the coupling is approaches the critical value from below.


title: Hyperbolic Inflation

abstract:
  A mathematically interesting hyperbolic solution to the Einstein field
equations is studied on an eight-dimensional pseudo-Riemannian manifold
$\mathbb{X}_{4,4}$ that is a spacetime of four space dimensions and four time
dimensions. [The signature and dimension of $\mathbb{X}_{4,4}$ are chosen
because its tangent spaces satisfy a triality principle \cite{Nash2010}
(vectors and spinors are equivalent).] This solution exhibits temporal
hyperbolic inflation of three of the four space dimensions and temporal
hyperbolic \textbf{deflation} of three of the four time dimensions. Comoving
coordinates for the \textbf{unscaled} dimensions are chosen to be $(x^4
\leftrightarrow \textrm{time}, x^8 \leftrightarrow \textrm{space})$, where the
$x^4$ coordinate corresponds to our universe's observed physical time dimension
and the $x^8$ coordinate corresponds to a predicted new physical spatial
dimension. This solution of the field equations manifests temporal hyperbolic
inflation $\cosh{({1}{3}\,H\,x^4)}$ of the scale factor associated with three
of the four space dimensions, and temporal deflation
$\textrm{sech}({{{1}{3}\,H\,x^4}})$ of the scale factor associated with three
of the four time dimensions. (Here $H$ is the Hubble parameter.) The scale
factors possess a more complicated dependence on the spatial $x^8$ coordinate,
which, however, turn out to be \textbf{periodic} in $x^8$ with period $\propto
1 / H$. \textbf{After "inflation" the observed physical macroscopic world has
three space dimensions and one time dimension.}


title: RMCMC: A System for Updating Bayesian Models

abstract:
  A system to update estimates from a sequence of probability distributions is
presented. The aim of the system is to quickly produce estimates with a
user-specified bound on the Monte Carlo error. The estimates are based upon
weighted samples stored in a database. The stored samples are maintained such
that the accuracy of the estimates and quality of the samples is satisfactory.
This maintenance involves varying the number of samples in the database and
updating their weights. New samples are generated, when required, by a Markov
chain Monte Carlo algorithm. The system is demonstrated using a football league
model that is used to predict the end of season table. Correctness of the
estimates and their accuracy is shown in a simulation using a linear Gaussian
model.


title:
First Order Decidability and Definability of Integers in Infinite
  Algebraic Extensions of Rational Numbers

abstract:
  We extend results of Videla and Fukuzaki to define algebraic integers in
large classes of infinite algebraic extensions of Q and use these definitions
for some of the fields to show the first-order undecidability. We also obtain a
structural sufficient condition for definability of the ring of integers over
its field of fractions. In particular, we show that the following propositions
hold. (1) For any rational prime $q$ and any positive rational integer $m$,
algebraic integers are definable in any Galois extension of Q where the degree
of any finite subextension is not divisible by $q^{m}$. (2) Given a prime $q$,
and an integer $m>0$, algebraic integers are definable in a cyclotomic
extension (and any of its subfields) generated by any set $\{\xi_{p^{\ell}}|
\ell \in \Z_{>0}, p \not=q {is any prime such that} q^{m +1}\not | (p-1)\}$.
(3) The first-order theory of any abelian extension of Q with finitely many
ramified rational primes is undecidable. We also show that under a condition on
the splitting of one rational prime in an infinite algebraic extension of Q,
the existence of a finitely generated elliptic curve over the field in question
is enough to have a definition of Z and to show that the field is indecidable.


title:
Spin fragmentation of Bose-Einstein condensates with antiferromagnetic
  interactions

abstract:
  We study spin fragmentation of an antiferromagnetic spin 1 condensate in the
presence of a quadratic Zeeman (QZ) effect breaking spin rotational symmetry.
We describe how the QZ effect turns a fragmented spin state, with large
fluctuations of the Zeemans populations, into a regular polar condensate, where
atoms all condense in the $m=0$ state along the field direction. We calculate
the average value and variance of the Zeeman state $m=0$ to illustrate clearly
the crossover from a fragmented to an unfragmented state. The typical width of
this crossover is $q \sim k_B T/N$, where $q$ is the QZ energy, $T$ the spin
temperature and $N$ the atom number. This shows that spin fluctuations are a
mesoscopic effect that will not survive in the thermodynamic limit
$N\rightarrow \infty$, but are observable for sufficiently small atom number.


title: Rainbow gravity and scale-invariant fluctuations

abstract:
  We re-examine a recently proposed scenario where the deformed dispersion
relations associated with a flow of the spectral dimension to a UV value of 2
leads to a scale-invariant spectrum of cosmological fluctuations, without the
need for inflation. In that scenario Einstein gravity was assumed. The theory
displays a wavelength-dependent speed of light but by transforming to a
suitable "rainbow frame" this feature can be removed, at the expense of
modifying gravity. We find that the ensuing rainbow gravity theory is such that
gravity switches off at high energy (or at least leads to a universal conformal
coupling). This explains why the fluctuations are scale-invariant on all
scales: there is no horizon scale as such. For dispersion relations that do not
lead to exact scale invariance we find instead esoteric inflation in the
rainbow frame. We argue that these results shed light on the behaviour of
gravity under the phenomenon of dimensional reduction.


title: Remarks on the Moser-Trudinger inequality

abstract:
  We extend the Moser-Trudinger inequality to any Euclidean domain satisfying
Poincar\'e's inequality. We find out that the same equivalence does not hold in
general for conformal metrics on the unit ball, showing counterexamples. We
also study the existence of extremals for the Moser-Trudinger inequalities for
unbounded domains, proving it for the infinite planar strip.


title: Simulating the Dynamics of T Cell Subsets Throughout the Lifetime

abstract:
  It is widely accepted that the immune system undergoes age-related changes
correlating with increased disease in the elderly. T cell subsets have been
implicated. The aim of this work is firstly to implement and validate a
simulation of T regulatory cell (Treg) dynamics throughout the lifetime, based
on a model by Baltcheva. We show that our initial simulation produces an
inversion between precursor and mature Treys at around 20 years of age, though
the output differs significantly from the original laboratory dataset.
Secondly, this report discusses development of the model to incorporate new
data from a cross-sectional study of healthy blood donors addressing balance
between Treys and Th17 cells with novel markers for Treg. The potential for
simulation to add insight into immune aging is discussed.


title: The kilo-second variability of X-ray sources in nearby galaxies

abstract:
  Chandra observations of 17 nearby galaxies were analysed and 166 bright
sources with X-ray counts > 100, were chosen for temporal analysis. Fractional
root mean square variability amplitudes were estimated for lightcurves binned
at ~ 4 ksec and of length ~ 40 ksec. While there are nine ultra-luminous X-ray
sources (ULXs) with unabsorbed luminosity (in 0.3-8.0 keV band) L > 10^39 erg/s
in the sample for which the fractional r.m.s variability is constrained to be <
10%, only two of them show variability. One of the variable ULXs exhibits a
secular transition and has a ultra-soft spectrum with temperature ~ 0.3 keV
while the other is a rapidly varying source in NGC 0628, which has been
previously compared to the Galactic micro-quasar GRS1915+105. These results
seem to indicate that ULXs are typically not highly variable in ksec
time-scales, except for some ultra-soft ones. Among the relatively low
luminosity sources (L ~ 10^38 erg/s) we find five of them to be variable. Apart
from an earlier known source in NGC 1569, we identify a source in NGC 2403,
which exhibits persistent high amplitude fluctuations.The variability of the
sources in general, do not seem to be correlated with hardness,which indicates
that they may not be due to variations in any absorbing material, but instead
could reflect inner accretion disk instabilities.


title: Comparing Decison Support Tools for Cargo Screening Processes

abstract:
  When planning to change operations at ports there are two key stake holders
with very different interests involved in the decision making processes. Port
operators are attentive to their standards, a smooth service flow and economic
viability while border agencies are concerned about national security. The time
taken for security checks often interferes with the compliance to service
standards that port operators would like to achieve. Decision support tools as
for example Cost-Benefit Analysis or Multi Criteria Analysis are useful helpers
to better understand the impact of changes to a system. They allow
investigating future scenarios and helping to find solutions that are
acceptable for all parties involved in port operations. In this paper we
evaluate two different modelling methods, namely scenario analysis and discrete
event simulation. These are useful for driving the decision support tools (i.e.
they provide the inputs the decision support tools require). Our aims are, on
the one hand, to guide the reader through the modelling processes and, on the
other hand, to demonstrate what kind of decision support information one can
obtain from the different modelling methods presented.