title:
Bulk high-Tc superconductors with drilled holes: how to arrange the
  holes to maximize the trapped magnetic flux ?

abstract:
  Drilling holes in a bulk high-Tc superconductor enhances the oxygen annealing
and the heat exchange with the cooling liquid. However, drilling holes also
reduces the amount of magnetic flux that can be trapped in the sample. In this
paper, we use the Bean model to study the magnetization and the current line
distribution in drilled samples, as a function of the hole positions. A single
hole perturbs the critical current flow over an extended region that is bounded
by a discontinuity line, where the direction of the current density changes
abruptly. We demonstrate that the trapped magnetic flux is maximized if the
center of each hole is positioned on one of the discontinuity lines produced by
the neighbouring holes. For a cylindrical sample, we construct a polar
triangular hole pattern that exploits this principle; in such a lattice, the
trapped field is ~20% higher than in a squared lattice, for which the holes do
not lie on discontinuity lines. This result indicates that one can
simultaneously enhance the oxygen annealing, the heat transfer, and maximize
the trapped field.


title: Quark number susceptibility around the critical end point

abstract:
  The quark number susceptibility is expressed as an integral in terms of
dressed quark propagator and dressed vector vertex. It is then investigated
with the latter two- and three-point functions confronted with a
Dyson-Schwinger equation model which accommodates both finite temperature and
baryon chemical potential. The critical end point in the phase diagram is
identified and the behavior of the quark number susceptibility around the
critical end point is highlighted. The characteristic features found agree well
with recent lattice QCD simulation results.


title:
Slow Dynamics in Hard Condensed Matter: A Case Study of the Phase
  Separating System NdNiO$_3$

abstract:
  We report the time dependent response of electrical resistivity in the
non-magnetic perovskite oxide NdNiO$_3$ in its phase separated state and
provide a physical explanation of the observations. We also model the system
and do an accurate Monte Carlo simulation of the observed behavior. While
cooling a phase separation takes place in this system below its metal-insulator
transition temperature and in this state the material exhibits various
dynamical phenomena such as relaxation of resistivity, dependence of
resistivity on cooling rate and rejuvenation of the material after ageing.
These phenomena signal that the phase separated state of NdNiO$_3$ is not in
thermodynamic equilibrium and we conjecture that it consists of supercooled
paramagnetic metallic and antiferromagnetic insulating phases. The supercooled
phases are metastable and they switch over to the insulating equilibrium state
stochastically and this can account for the slow dynamics observed in our
system. We also verify the predictive power of our model by simulating the
result of a new experiment and confirming it by actual measurements.


title: Young Brown Dwarfs in the Core of the W3 Main Star-Forming Region

abstract:
  We present the results of deep and high-resolution (FWHM ~ 0".35) JHK NIR
observations with the Subaru telescope, to search for very low mass young
stellar objects (YSOs) in the W3 Main star-forming region. The NIR survey
covers an area of ~ 2.6 arcmin^2 with 10-sigma limiting magnitude exceeding 20
mag in the JHK bands. The survey is sensitive enough to provide unprecedented
details in W3 IRS 5 region and reveals a census of the stellar population down
to objects below the hydrogen-burning limit. We construct JHK color-color (CC)
and J-H/J and H-K/K color-magnitude (CM) diagrams to identify very low
luminosity YSOs and to estimate their masses. Based on these CC and CM
diagrams, we identified a rich population of embedded YSO candidates with
infrared excesses (Class I and Class II), associated with the W3 Main region. A
large number of red sources (H-K > 2) have also been detected around W3 Main.
We argue that these red stars are most probably pre-main-sequence (PMS) stars
with intrinsic color excesses. Based on the comparison between theoretical
evolutionary models of very low-mass PMS objects with the observed CM diagram,
we find there exists a substantial substellar population in the observed
region. The mass function (MF) does not show the presence of cutoff and sharp
turnover around the substellar limit, at least at the hydrogen-burning limit.
Furthermore, the MF slope indicates that the number ratio of young brown dwarfs
and hydrogen-burning stars in the W3 Main is probably higher than those in
Trapezium and IC 348. The presence of mass segregation, in the sense that
relatively massive YSOs lie near the cluster center, is seen. The estimated
dynamical evolution time indicates that the observed mass segregation in the W3
Main may be the imprint of the star formation process.


title: Magnetic Response of NiFe2O4 nanoparticles in polymer matrix

abstract:
  We report the magnetic properties of magnetic nano-composite, consisting of
different quantity of NiFe2O4 nanoparticles in polymer matrix. The
nanoparticles exhibited a typical magnetization blocking, which is sensitive on
the variation of magnetic field, mode of zero field cooled/field cooled
experiments and particle quantity in the matrix. The samples with lower
particle quantity showed an upturn of magnetization down to 5 K, whereas the
blocking of magnetization dominates at lower temperatures as the particle
quantity increases in the polymer. We examine such magnetic behaviour in terms
of the competitive magnetic ordering between core and surface spins of
nanoparticles, taking into account the effect of inter-particle (dipole-dipole)
interactions on nanoparticle magnetic dynamics.


title:
Possible canonical distributions for finite systems with nonadditive
  energy

abstract:
  It is shown that a small system in thermodynamic equilibrium with a finite
thermostat can have a q-exponential probability distribution which closely
depends on the energy nonextensivity and the particle number of the thermostat.
The distribution function will reduce to the exponential one at the
thermodynamic limit. However, the nonextensivity of the system should not be
neglected.


title: Elasticity and electrostatics of plectonemic DNA

abstract:
  We present a self-contained theory for the mechanical response of DNA in
single molecule experiments. Our model is based on a 1D continuum description
of the DNA molecule and accounts both for its elasticity and for DNA-DNA
electrostatic interactions. We consider the classical loading geometry used in
experiments where one end of the molecule is attached to a substrate and the
other one is pulled by a tensile force and twisted by a given number of turns.
We focus on configurations relevant to the limit of a large number of turns,
which are made up of two phases, one with linear DNA and the other one with
superhelical DNA. The model takes into account thermal fluctuations in the
linear phase and electrostatic interactions in the superhelical phase. The
values of the torsional stress, of the supercoiling radius and angle, and key
features of the experimental extension-rotation curves, namely the slope of the
linear region and thermal buckling threshold, are predicted. They are found in
good agreement with experimental data.


title:
Structural relaxation effects on interface and transport properties of
  Fe/MgO(001) tunnel junctions

abstract:
  The interface structure of Fe/MgO(100) magnetic tunnel junctions predicted by
density functional theory (DFT) depends significantly on the choice of exchange
and correlation functional. Bader analysis reveals that structures obtained by
relaxing the cell with the local spin-density approximation (LSDA) display a
different charge transfer than those relaxed with the generalized gradient
approximation (GGA). As a consequence, the electronic transport is found to be
extremely sensitive to the interface structure. In particular, the conductance
for the LSDA-relaxed geometry is about one order of magnitude smaller than that
of the GGA-relaxed one. The high sensitivity of the electronic current to the
details of the interface might explain the discrepancy between the experimental
and calculated values of magnetoresistance.


title:
A General formulation for standardization of rates as a method to
  control confounding by measured and unmeasured disease risk factors

abstract:
  Standardization, a common approach for controlling confounding in
population-studies or data from disease registries, is defined to be a weighted
average of stratum specific rates. Typically, discussions on the construction
of a particular standardized rate regard the strata as fixed, and focus on the
considerations that affect the specification of weights. Each year the data
from the SEER cancer registries are analyzed using a weighting procedure
referred to as ``direct standardization for age.'' To evaluate the performance
of direct standardization, we define a general class of standardization
operators. We regard a particular standardized rate to be the output of an
operator and a given data set. Based on the functional form of the operators,
we define a subclass of standardization operators that controls for confounding
by measured risk factors. Using the fundamental disease probability paradigm
for inference, we establish the conclusions that can be drawn from year-to-year
contrasts of standardized rates produced by these operators in the presence of
unmeasured cancer risk factors. These conclusions take the form of falsifying
specific assumptions about the conditional probabilities of disease given all
the risk factors (both measured and unmeasured), and the conditional
probabilities of the unmeasured risk factors given the measured risk factors.
We show the one-to-one correspondence between these falsifications and the
inferences made from the contrasts of directly standardized rates reported each
year in the Annual Report to the Nation on the Status of Cancer.


title: An Investigation on Cooling of CZT Co-Planar Grid Detectors

abstract:
  The effect of moderate cooling on CdZnTe semiconductor detectors has been
studied for the COBRA experiment. Improvements in energy resolution and low
energy threshold were observed and quantified as a function of temperature.
Leakage currents are found to contribute typically $\sim$5 keV to the widths of
photopeaks.


title: Quantum simulations based on measurements and feedback control

abstract:
  We propose a scheme for performing quantum simulations with atoms in cavities
based on a photon detection feedback loop that requires only linear optical
elements. Atoms can be stored individually without the need of directly
interacting with one another. The scheme is able to simulate any time evolution
that can be written as a sum of two-qubit Hamiltonians, .e.g., any next
neighbor interaction on a lattice. It can also be made robust against photon
losses.


title: Non-universal scalar-tensor theories and big bang nucleosynthesis

abstract:
  We investigate the constraints that can be set from big-bang nucleosynthesis
on two classes of models: extended quintessence and scalar-tensor theories of
gravity in which the equivalence principle between standard matter and dark
matter is violated. In the latter case, and for a massless dilaton with
quadratic couplings, the phase space of theories is investigated. We delineate
those theories where attraction toward general relativity occurs. It is shown
that big-bang nucleosynthesis sets more stringent constraints than those
obtained from Solar system tests.


title:
Some Probabilistic and Statistical Properties of a Random Coefficient
  Autoregressive Model

abstract:
  A statistical inference for random coefficient first-order autoregressive
model $[RCAR(1)]$ was investigated by P.M. ROBINSON (1978) in which the
coefficients varying over individuals. In this paper we attempt to generalize
this result to random coefficient autoregressive model of order $p$
$[RCAR(p)]$. The stationarity condition will derived for this model.


title: Stochastic integrals and conditional full support

abstract:
  We present conditions that imply the conditional full support (CFS) property,
introduced by Guasoni, R\'asonyi, and Schachermayer [Ann. Appl. Probab., 18
(2008), pp. 491--520], for processes Z := H + K \cdot W, where W is a Brownian
motion, H is a continuous process, and processes H and K are either progressive
or independent of W. Moreover, in the latter case under an additional
assumption that K is of finite variation, we present conditions under which Z
has CFS also when W is replaced with a general continuous process with CFS. As
applications of these results, we show that several stochastic volatility
models and the solutions of certain stochastic differential equations have CFS.


title: Active Galactic Nuclei: Sources for ultra high energy cosmic rays?

abstract:
  The origin of ultra high energy cosmic rays promises to lead us to a deeper
understanding of the structure of matter. This is possible through the study of
particle collisions at center-of-mass energies in interactions far larger than
anything possible with the Large Hadron Collider, albeit at the substantial
cost of no control over the sources and interaction sites. For the extreme
energies we have to identify and understand the sources first, before trying to
use them as physics laboratories. Here we describe the current stage of this
exploration. The most promising contenders as sources are radio galaxies and
gamma ray bursts. The sky distribution of observed events yields a hint
favoring radio galaxies. Key in this quest are the intergalactic and galactic
magnetic fields, whose strength and structure are not yet fully understood.
Current data and statistics do not yet allow a final judgment. We outline how
we may progress in the near future.


title: On the decay of solutions to a class of defocusing NLS

abstract:
  We consider the following family of Cauchy problems: {equation*} i\partial_t
u= \Delta u - u|u|^\alpha, (t,x) \in \R \times \R^d {equation*}
$$u(0)=\varphi\in H^1(\R^d)$$ where $0<\alpha<\frac 4{d-2}$ for $d\geq 3$ and
$0<\alpha<\infty$ for $d=1,2$. We prove that the $L^r$-norms of the solutions
decay as $t\to \pm \infty$, provided that $2<r<\frac{2d}{d-2}$ when $d\geq 3$
and $2<r<\infty$ when $d=1,2$. In particular we extend previous results
obtained by Ginibre and Velo for $d\geq 3$ and by Nakanishi for $d=1,2$, where
the same decay results are proved under the extra assumption $\alpha >\frac
4d$.


title:
Two complex problems on the lattice: transport coefficients and finite
  chemical potential

abstract:
  After a few remarks about the problem of extracting transport coefficients
from lattice QCD calculations, I report on recent developments in applying
stochastic quantization and complex Langevin dynamics to field theories with a
complex action due to a nonzero chemical potential. First results demonstrate
that the sign problem poses no obstacle for this approach, even in the
thermodynamic limit. I conclude with a comparison of two simple one-link
models, describing a euclidean system at finite chemical potential and a
Minkowski system in real time.


title: Dynamics of substructures in warm dark-matter cosmologies

abstract:
  We performed cosmological simulations based upon both a cold dark matter
(CDM) and a warm dark matter (WDM) model. The focus of our investigations lies
with selected spatial and kinematic properties of substructure halos (subhalos)
orbiting within host halos, that form in both dark-matter cosmologies. We aim
at using the dynamics of the subhalos as a probe of the respective cosmology.


title:
Development of CMOS monolithic pixel sensors with in-pixel correlated
  double sampling and fast readout

abstract:
  This paper presents the design and results of detailed tests of a CMOS active
pixel chip for charged particle detection with in-pixel charge storage for
correlated double sampling and readout in rolling shutter mode at frequencies
up to 25 MHz. This detector is developed in the framework of R&D for the Vertex
Tracker for a future e+e- Linear Collider.


title:
Universal Characteristics of Fractal Fluctuations in Prime Number
  Distribution

abstract:
  The frequency of occurrence of prime numbers at unit number spacing intervals
exhibits selfsimilar fractal fluctuations concomitant with inverse power law
form for power spectrum generic to dynamical systems in nature such as fluid
flows, stock market fluctuations, population dynamics, etc. The physics of
long-range correlations exhibited by fractals is not yet identified. A recently
developed general systems theory visualises the eddy continuum underlying
fractals to result from the growth of large eddies as the integrated mean of
enclosed small scale eddies, thereby generating a hierarchy of eddy
circulations, or an inter-connected network with associated long-range
correlations. The model predictions are as follows: (i) The probability
distribution and power spectrum of fractals follow the same inverse power law
which is a function of the golden mean. The predicted inverse power law
distribution is very close to the statistical normal distribution for
fluctuations within two standard deviations from the mean of the distribution.
(ii) Fractals signify quantumlike chaos since variance spectrum represents
probability density distribution, a characteristic of quantum systems such as
electron or photon. (ii) Fractal fluctuations of frequency distribution of
prime numbers signify spontaneous organisation of underlying continuum number
field into the ordered pattern of the quasiperiodic Penrose tiling pattern. The
model predictions are in agreement with the probability distributions and power
spectra for different sets of frequency of occurrence of prime numbers at unit
number interval for successive 1000 numbers. Prime numbers in the first 10
million numbers were used for the study.


title: Amido Rhenium Trioxides: Cases of Hindered Agostic C-H-M Interactions?

abstract:
  The amido rhenium trioxides of composition (iPr2N)ReO3, (iPrCyN)ReO3 and
(Cy2N)ReO3 (Cy = cyclohexyl) were synthesized in a one pot reaction starting
from Re2O7, Me3SiCl and the corresponding amines (iPr)2NH, (iPr)(Cy)NH, and
(Cy)2NH, respectively. In the solid state the amido ligands of all three
complexes are asymmetrically coordinated to the ReO3 core allowing for one
short Re-H-C contact in each case which might indicate the presence of
beta-agostic interaction. However, analysis of the charge density distribution
provided us clear-cut criteria that beta-agostic interactions are suppressed by
the trans-influence of the oxo-groups. Comparison with structurally related
tetra-coordinated d0 titanium amido complexes highlighted a systematic concept
how the extent of beta-agostic interactions in these complexes can be
controlled by reducing the trans-influence of the co-ligands. We therefore
suggest to employ the expression "hindered agostic interactions" in cases where
covalent M-H-C are in principle supported by vacant coordination sites at
Lewis-acidic metal centers but are actually hindered for electronic reasons. We
further point out that electronic hindrance originating from the transinfluence
might be overruled by changing the s/p-donor characteristics of ligands.


title:
Are there basic physical constraints on future anthropogenic emissions
  of carbon dioxide?

abstract:
  Global Climate Models (GCMs) provide forecasts of future climate warming
using a wide variety of highly sophisticated anthropogenic CO2 emissions models
as input, each based on the evolution of four emissions "drivers": population
p, standard of living g, energy productivity (or efficiency) f and energy
carbonization c. The range of scenarios considered is extremely broad, however,
and this is a primary source of forecast uncertainty. Here, it is shown both
theoretically and observationally how the evolution of the human system can be
considered from a surprisingly simple thermodynamic perspective in which it is
unnecessary to explicitly model two of the emissions drivers: population and
standard of living. Specifically, the human system grows through a
self-perpetuating feedback loop in which the consumption rate of primary energy
resources stays tied to the historical accumulation of global economic
production - or p times g - through a time-independent factor of 9.7 +/- 0.3
milliwatts per inflation-adjusted 1990 US dollar. This important constraint,
and the fact that f and c have historically varied rather slowly, points
towards substantially narrowed visions of future emissions scenarios for
implementation in GCMs.


title:
Al doped graphene: A promising material for hydrogen storage at room
  temperature

abstract:
  A promising material for hydrogen storage at room temperature-Al doped
graphene was proposed theoretically by using density functional theory
calculation. Hydrogen storage capacity of 5.13 wt% was predicted at T = 300 K
and P = 0.1 Gpa with adsorption energy Eb = -0.260 eV/H2. This is close to the
target of 6 wt% and satisfies the requirement of immobilization hydrogen with
Eb of -0.2 ~ -0.4 eV/H2 at ambient temperature and modest pressure for
commercial applications specified by U.S. Department of Energy. It is believed
that the doped Al varies the electronic structures of both C and H2. The bands
of H2 overlapping with those of Al and C synchronously are the underlying
mechanism of hydrogen storage capacity enhancement.


title: Generic phase diagram of "electron-doped" T' cuprates

abstract:
  We investigated the generic phase diagram of the electron doped
superconductor, Nd2-xCexCuO4, using films prepared by metal organic
decomposition. After careful oxygen reduction treatment to remove interstitial
Oap atoms, we found that the Tc increases monotonically from 24 K to 29 K with
decreasing x from 0.15 to 0.00, demonstrating a quite different phase diagram
from the previous bulk one. The implication of our results is discussed on the
basis of tremendous influence of Oap "impurities" on superconductivity and also
magnetism in T' cuprates. Then we conclude that our result represents the
generic phase diagram for oxygen-stoichiometric Nd2-xCexCuO4.


title: Synthesis of infinite-layer LaNiO2 films by metal-organic deposition

abstract:
  We report the synthesis of infinite-layer LaNiO2 thin films by metal organic
decomposition. Our work is aimed to synthesize perovskite-like oxides with 3d9
electronic configuration, which is common to high-Tc copper oxides. The 3d9
configuration is very rare in oxides other than cuprates. Ni1+ oxides, even
though Ni1+ is an unusual oxidation state, may be one of very few candidates.
One example of the Ni1+ phases is infinite-layer LaNiO2. The bulk synthesis of
LaNiO2 is difficult, but we demonstrate in this article that the thin-film
synthesis of LaNiO2 by metal organic decomposition is rather easy. This is due
to the advantage of thin films with a large-surface-to-volume ratio, which
makes oxygen diffusion prompt. Resistivity measurements indicate that LaNiO2 is
essentially a metal but unfortunately with no trace of superconductivity yet.


title:
A Basic Framework for the Cryptanalysis of Digital Chaos-Based
  Cryptography

abstract:
  Chaotic cryptography is based on the properties of chaos as source of
entropy. Many different schemes have been proposed to take advantage of those
properties and to design new strategies to encrypt information. However, the
right and efficient use of chaos in the context of cryptography requires a
thorough knowledge about the dynamics of the selected chaotic system. Indeed,
if the final encryption system reveals enough information about the underlying
chaotic system it could be possible for a cryptanalyst to get the key, part of
the key or some information somehow equivalent to the key just analyzing those
dynamical properties leaked by the cryptosystem. This paper shows what those
dynamical properties are and how a cryptanalyst can use them to prove the
inadequacy of an encryption system for the secure exchange of information. This
study is performed through the introduction of a series of mathematical tools
which should be the basic framework of cryptanalysis in the context of digital
chaos-based cryptography.


title: Heat transfer mechanisms in bubbly Rayleigh-Benard convection

abstract:
  The heat transfer mechanism in Rayleigh-Benard convection in a liquid with a
mean temperature close to its boiling point is studied through numerical
simulations with point-like vapor bubbles, which are allowed to grow or shrink
through evaporation and condensation and which act back on the flow both
thermally and mechanically. It is shown that the effect of the bubbles is
strongly dependent on the ratio of the sensible heat to the latent heat as
embodied in the Jacob number Ja. For very small Ja the bubbles stabilize the
flow by absorbing heat in the warmer regions and releasing it in the colder
regions. With an increase in Ja, the added buoyancy due to the bubble growth
destabilizes the flow with respect to single-phase convection and considerably
increases the Nusselt number.


title:
The physical properties of Lyalpha emitting galaxies: not just primeval
  galaxies?

abstract:
  We have analyzed a sample of LBGs from z =3.5 to z=6 selected from the
GOODS-S field as B,V and i-dropouts, and with spectroscopic observations
showing that they have the Lyalpha line in emission. Our main aim is to
investigate their physical properties and their dependence on the emission line
characteristics, to shed light on the relation between galaxies with Lyalpha
emission and the general LBG population.The objects were selected from their
continuum colors and then spectroscopically confirmed by the GOODS
collaboration and other campaigns. From the spectra we derived the line flux
and EW. We then used U-band to mid-IR photometry from GOODS-MUSIC to derive the
physical properties of the galaxies, such as total stellar mass, age and so on,
through standard SED fitting techniques.Although most galaxies are fit by young
stellar populations, a small but non negligible fraction has SEDs that require
considerably older stellar component, up to 1 Gyr. There is no apparent
relation between age and EW: some of the oldest galaxies have large EW, and
should be also selected in narrow band surveys. Therefore not all Lyalpha
emitters are primeval galaxies in the very early stages of formation,as is
commonly assumed. We also find a large range of stellar populations, with
masses from 5x10^8 Msol to 5x10^10 Msol and SFR from few to 60 Msol/yr.
Although there is no correlation between mass and EW, we find a significant
lack of massive galaxies with high EW, which could be explained if the most
massive galaxies were more dusty and/or contained more neutral gas than less
massive objects. Finally we find that more than half of the galaxies contain
small but non negligible amounts of dust: the mean E(B-V) and the EW are well
correlated, although with a large scatter, as already found at lower redshift


title:
On optimality of the barrier strategy in de Finetti's dividend problem
  for spectrally negative L\'{e}vy processes

abstract:
  We consider the classical optimal dividend control problem which was proposed
by de Finetti [Trans. XVth Internat. Congress Actuaries 2 (1957) 433--443].
Recently Avram, Palmowski and Pistorius [Ann. Appl. Probab. 17 (2007) 156--180]
studied the case when the risk process is modeled by a general spectrally
negative L\'{e}vy process. We draw upon their results and give sufficient
conditions under which the optimal strategy is of barrier type, thereby helping
to explain the fact that this particular strategy is not optimal in general. As
a consequence, we are able to extend considerably the class of processes for
which the barrier strategy proves to be optimal.


title: Airy processes with wanderers and new universality classes

abstract:
  Consider $n+m$ nonintersecting Brownian bridges, with $n$ of them leaving
from 0 at time $t=-1$ and returning to 0 at time $t=1$, while the $m$ remaining
ones (wanderers) go from $m$ points $a_i$ to $m$ points $b_i$. First, we keep
$m$ fixed and we scale $a_i,b_i$ appropriately with $n$. In the large-$n$
limit, we obtain a new Airy process with wanderers, in the neighborhood of
$\sqrt{2n}$, the approximate location of the rightmost particle in the absence
of wanderers. This new process is governed by an Airy-type kernel, with a
rational perturbation. Letting the number $m$ of wanderers tend to infinity as
well, leads to two Pearcey processes about two cusps, a closing and an opening
cusp, the location of the tips being related by an elliptic curve. Upon tuning
the starting and target points, one can let the two tips of the cusps grow very
close; this leads to a new process, which might be governed by a kernel,
represented as a double integral involving the exponential of a quintic
polynomial in the integration variables.


title:
Angular distribution of positrons in coherent pair production in
  deformed crystals

abstract:
  We investigate the angular distribution of positrons in the coherent process
electronpositron pair creation process by high-energy photons in a periodically
deformed single crystal with a complex base. The formula for the corresponding
differential cross-section is derived for an arbitrary deformation field. The
case is considered in detail when the photon enters into the crystal at small
angles with respect to a crystallographic axis. The results of the numerical
calculations are presented for${\mathrm{SiO}}_{2}$ and diamond single crystals
and Moliere parameterization of the screened atomic potentials in the case of
the deformation field generated by the acoustic wave of S-type.


title: First Nonlinear Syzygies of Ideals Associated to Graphs

abstract:
  Consider an ideal $I\subset K[x_1,..., x_n]$, with $K$ an arbitrary field,
generated by monomials of degree two. Assuming that $I$ does not have a linear
resolution, we determine the step $s$ of the minimal graded free resolution of
$I$ where nonlinear syzygies first appear, we show that at this step of the
resolution nonlinear syzygies are concentrated in degree $s+3$, and we compute
the corresponding graded Betti number $\beta_{s,s+3}$. The multidegrees of
these nonlinear syzygies are also determined and the corresponding multigraded
Betti numbers are shown to be all equal to 1.


title: Perturbative Reheating and Gravitino Production in Inflationary Models

abstract:
  The low reheat temperature at the end of inflation from the gravitino bound
constrains the creation of heavy Majorana neutrinos associated with models of
leptogenesis. However, a detailed view of the reheating of the Universe at the
end of inflation implies that the maximum temperature during reheating,
$\Tmax$, can be orders of magnitude higher than the final reheat temperature.
This then allows for the production of the heavy Majorana neutrinos needed for
leptogenesis. We carry out the complementary calculation of the gravitino
production during reheating and its dependence on $\Tmax$. We find that the
gravitino abundance generated during reheating for a quartic potential is
comparable to the standard estimate of the abundance generated after reheating
and study its consequences for leptogenesis.


title:
Probing Cosmic Dust of the Early Universe through High-Redshift
  Gamma-Ray Bursts

abstract:
  We explore the extinction properties of the dust in the distant universe
through the afterglows of high-redshifted GRBs based on the "Drude" model
which, unlike previous studies, does not require a prior assumption of template
extinction laws. We select GRB070802 at z~2.45 (which shows clear evidence for
the 2175\AA extinction bump) and GRB050904 at z~6.29, the 2nd most distant GRB
observed to date. We fit their afterglow spectra to determine the extinction of
their host galaxies. We find that (1) their extinction curves differ
substantially from that of the Milky Way, the Small and Large Magellanic Clouds
(which were widely adopted as template extinction laws in literature); (2) the
2175\AA extinction feature appears to be also present in GRB050904 at z~6.29;
and (3) there does not appear to show strong evidence for a dependence of dust
extinction on redshifts. The inferred extinction curves are closely reproduced
in terms of a mixture of amorphous silicate and graphite, both of which are
expected supernova condensates and have been identified in primitive meteorites
as presolar grains originating from supernovae (which are considered as the
main source of dust at high-z).


title:
Necessary Conditions for Discontinuities of Multidimensional Size
  Functions

abstract:
  Some new results about multidimensional Topological Persistence are
presented, proving that the discontinuity points of a k-dimensional size
function are necessarily related to the pseudocritical or special values of the
associated measuring function.


title: Matter induced charge symmetry violating NN potential

abstract:
  We construct density dependent Class $III$ charge symmetry violating (CSV)
potential due to mixing of $\rho$-$\omega$ meson with off-shell corrections.
Here in addition to the usual vacuum contribution, the matter induced mixing of
$\rho$-$\omega$ is also included. It is observed that the contribution of
density dependent CSV potential is comparable to that of the vacuum
contribution.


title: Extension of the EGS theorem to metric and Palatini f(R) gravity

abstract:
  By using the equivalence between metric and Palatini f(R) (or "modified")
gravities with omega=0, -3/2 Brans-Dicke theories, it is shown that the
Ehlers-Geren-Sachs theorem of general relativity is extended to modified
gravity. In the case of metric f(R) gravity previously studied, this agrees
with previous literature.


title: Cyclic shifts of the van der Corput set

abstract:
  In [13], K. Roth showed that the expected value of the $L^2$ discrepancy of
the cyclic shifts of the $N$ point van der Corput set is bounded by a constant
multiple of $\sqrt{\log N}$, thus guaranteeing the existence of a shift with
asymptotically minimal $L^2$ discrepancy, [11]. In the present paper, we
construct a specific example of such a shift.


title: On the long time behavior of Hilbert space diffusion

abstract:
  Stochastic differential equations in Hilbert space as random nonlinear
modified Schroedinger equations have achieved great attention in recent years;
of particular interest is the long time behavior of their solutions. In this
note we discuss the long time behavior of the solutions of the stochastic
differential equation describing the time evolution of a free quantum particle
subject to spontaneous collapses in space. We explain why the problem is subtle
and report on a recent rigorous result, which asserts that any initial state
converges almost surely to a Gaussian state having a fixed spread both in
position and momentum.


title: Density profiles of polarized Fermi gases confined in harmonic traps

abstract:
  On the basis of the phase diagram of the uniform system we calculate the
density profiles of a trapped polarized Fermi gas at zero temperature using the
local density approximation. By varying the overall polarization and the
interaction strength we analyze the appearance of a discontinuity in the
profile, signalling a first order phase transition from a superfluid inner core
to a normal outer shell. The local population imbalance between the two
components and the size of the various regions of the cloud corresponding to
different phases are also discussed. The calculated profiles are quantitatively
compared with the ones recently measured by Shin {\it et al.}, Phys. Rev. Lett.
{\bf 101}, 070404 (2008).


title:
High-pressure growth of fluorine-free SmFeAsO$_{1-x}$ superconducting
  single crystals

abstract:
  Superconducting single crystals of SmFeAsO$_{1-x}$ without fluorine doping
were grown at a pressure of 3.3 GPa and a temperature of 1350-1450 $^\circ$C by
using the self-flux method. Plate-like single crystals of a few-150 $\mu$m in
their lateral size were obtained. Single crystals showed the superconducting
transition at about 53.5 K with a narrow transition width of 0.5 K. The
synchrotron-irradiated x-ray diffractometry patterns and
high-angle-annular-dark-field scanning transmission electron microscopy images
point to the high quality of the crystals with a well-defined layered
tetragonal structure. The chemical compositions of the crystals were estimated
by using the electron-probe x-ray microanalysis.


title: Exact Exponential Time Algorithms for Max Internal Spanning Tree

abstract:
  We consider the NP-hard problem of finding a spanning tree with a maximum
number of internal vertices. This problem is a generalization of the famous
  Hamiltonian Path problem. Our dynamic-programming algorithms for general and
degree-bounded graphs have running times of the form O*(c^n) (c <= 3). The main
result, however, is a branching algorithm for graphs with maximum degree three.
It only needs polynomial space and has a running time of O*(1.8669^n) when
analyzed with respect to the number of vertices. We also show that its running
time is 2.1364^k n^O(1) when the goal is to find a spanning tree with at least
k internal vertices. Both running time bounds are obtained via a Measure &
Conquer analysis, the latter one being a novel use of this kind of analyses for
parameterized algorithms.


title:
Disorder Effects in La substituted ferrimagnetic Ca2FeMoO6 double
  perovskite

abstract:
  Ca2-xLaxFeMoO6 double perovskite with La concentration x = 0 to 0.6 was
synthesized using solid state sintering route. The standard techniques of XRD,
SEM and EDX were applied to characterize the material. Crystal structure of the
samples was stabilized in monoclinic phase with space group P2I/n and lattice
expansion was indicated with the increase of x. The increase of La
concentration gradually suppressed the coexisting minor secondary phase in the
material and simultaneously, EDX results indicated the accommodation of more Mo
atoms in the crystal structure. A significant modification in the surface
morphology of the material was noted from adhesive type surface for x = 0 to
brittle type surface with more grain boundary contributions for La doped
samples. We understand a significant change in magnetic properties (appearance
of cluster glass component, reduction of magnetic moment and indication of
higher TC) and in electrical properties (reduction of metallic character) in
terms of enhanced internal disorder in the material, introduced due to La
doping in double perovskite structure.


title: On the long time behavior of stochastic Schroedinger evolutions

abstract:
  We discuss the time evolution of the wave function which is solution of a
stochastic Schroedinger equation describing the dynamics of a free quantum
particle subject to spontaneous localizations in space. We prove global
existence and uniqueness of solutions. Observing that there exist three time
regimes, namely the collapse regime, after which the wave function is localized
in space; the classical regime, during which the collapsed wave function moves
along a classical path and the diffusive regime, in which diffusion overlaps
significantly the deterministic motion, we study the long time behavior of the
wave function. We assert that the general solution converges a.s. to a
diffusing Gaussian wave function having a finite spread both in position as
well as in momentum. This paper corrects and completes earlier works on this.


title: Action Theory Evolution

abstract:
  Like any other logical theory, domain descriptions in reasoning about actions
may evolve, and thus need revision methods to adequately accommodate new
information about the behavior of actions. The present work is about changing
action domain descriptions in propositional dynamic logic. Its contribution is
threefold: first we revisit the semantics of action theory contraction that has
been done in previous work, giving more robust operators that express minimal
change based on a notion of distance between Kripke-models. Second we give
algorithms for syntactical action theory contraction and establish their
correctness w.r.t. our semantics. Finally we state postulates for action theory
contraction and assess the behavior of our operators w.r.t. them. Moreover, we
also address the revision counterpart of action theory change, showing that it
benefits from our semantics for contraction.


title: On Binomial Summations and a Generalised Quantum SWAP Gate

abstract:
  We give a quantum gate construction - composed entirely from incidents of the
CNOT gate - that generalises the qubit SWAP gate to higher dimensions. This new
construction is more regular than and is an improvement on the WilNOT quantum
gate construction.


title:
First results on the interactions of relativistic $^9$C nuclei in
  nuclear track emulsion

abstract:
  \indent First results of the exposure of nuclear track emulsions in a
secondary beam enriched by $^9$C nuclei at energy of 1.2 A GeV are described.
The presented statistics corresponds to the most peripheral $^9$C interactions.
For the first time a dissociation $^9$C $\to3^3$He not accompanied by target
fragments and mesons is identified.\par


title: The 2D Hubbard model on the honeycomb lattice

abstract:
  We consider the 2D Hubbard model on the honeycomb lattice, as a model for a
single layer graphene sheet in the presence of screened Coulomb interactions.
At half filling and weak enough coupling, we compute the free energy, the
ground state energy and we construct the correlation functions up to zero
temperature in terms of convergent series; analiticity is proved by making use
of constructive fermionic renormalization group methods. We show that the
interaction produces a modification of the Fermi velocity and of the wave
function renormalization without changing the asymptotic infrared properties of
the model with respect to the unperturbed non-interacting case; this rules out
the possibility of superconducting or magnetic instabilities in the ground
state. We also prove that the correlations verify a Ward Identity similar to
the one for massless Dirac fermions, up to asymptotically negligible
corrections and a renormalization of the charge velocity.


title: Ferrers Dimension and Boxicity

abstract:
  This note explores the relation between the boxicity of undirected graphs and
the Ferrers dimension of digraphs.


title: 3C66B as a TeV radiogalaxy

abstract:
  The MAGIC collaboration reported the detection of a new VHE source, MAGIC
J0223+430, located close to the position of the blazar 3C66A, considered a
candidate TeV blazar since a long time. A careful analysis showed that the
events with energies above 150 GeV are centered on the position of the FRI
radiogalaxy 3C66B (at 6 arcmin from 3C66A), with a probability of 95.4% (85.4%
including systematic uncertainties) that the source is not related to 3C66A. We
present a model for the possible emission of 3C66B based on the structured jet
model already used to interpret the TeV emission of the radiogalaxy M87. The
model requires parameters similar to those used for M87 but a larger luminosity
for the layer, to account for the more luminous TeV emission. We also show that
the spectrum obtained by MAGIC can be interpreted as the combined emission of
3C66B, dominating above ~200 GeV, and of 3C66A. The high-energy emission from
the latter source, being strongly attenuated by the interaction with the
extragalactic background light, can only contribute at low energies. If we were
to see the jet emission of 3C 66B at small viewing angles we would see a
spectral energy distribution closely resembling the one of S5 0716+714, a
typical blazar.


title:
Semiclassical Theory for Decay and Fragmentation Processes in Chaotic
  Quantum Systems

abstract:
  We consider quantum decay and photofragmentation processes in open chaotic
systems in the semiclassical limit. We devise a semiclassical approach which
allows us to consistently calculate quantum corrections to the classical decay
to high order in an expansion in the inverse Heisenberg time. We present
results for systems with and without time reversal symmetry and also for the
symplectic case, as well as extending recent results to non-localized initial
states. We further analyze related photodissociation and photoionization
phenomena and semiclassically compute cross-section correlations, including
their Ehrenfest time dependence.


title: The Expressive Power of Binary Submodular Functions

abstract:
  It has previously been an open problem whether all Boolean submodular
functions can be decomposed into a sum of binary submodular functions over a
possibly larger set of variables. This problem has been considered within
several different contexts in computer science, including computer vision,
artificial intelligence, and pseudo-Boolean optimisation. Using a connection
between the expressive power of valued constraints and certain algebraic
properties of functions, we answer this question negatively.
  Our results have several corollaries. First, we characterise precisely which
submodular functions of arity 4 can be expressed by binary submodular
functions. Next, we identify a novel class of submodular functions of arbitrary
arities which can be expressed by binary submodular functions, and therefore
minimised efficiently using a so-called expressibility reduction to the Min-Cut
problem. More importantly, our results imply limitations on this kind of
reduction and establish for the first time that it cannot be used in general to
minimise arbitrary submodular functions. Finally, we refute a conjecture of
Promislow and Young on the structure of the extreme rays of the cone of Boolean
submodular functions.


title:
Controllable transport mean free path of light in xerogel matrixes
  embedded with polystyrene spheres

abstract:
  Xerogel matrices, made by sol-gel techniques, are embedded with polystyrene
spheres to promote multiple scattering of light. Varying the concentration of
the spheres inside the matrix allows one to adjust the transport mean free path
of light inside the material. Coherent backscattering measurements show that a
range of transport mean free paths from 90 to 600 nm is easily achieved. The
determination of the matrix refractive index permits a direct comparison to
multiple scattering and Mie theory. Such tunable diffusive sol-gel derived
samples can be further optimized as random laser materials.


title: Finite volume effects and dynamical chiral symmetry breaking in QED3

abstract:
  We investigate the impact of finite volume effects on the critical number of
flavours, N_f^c, for chiral symmetry restoration in QED3. To this end we solve
a set of coupled Dyson-Schwinger equations on a torus. For order parameters
such as the anomalous dimension of the fermion wave function or the chiral
condensate we find substantial evidence for a large dependence on the volume.
We observe a shift in N_f^c from values in the range of 3.61 \le N_f^c \le 3.84
in the infinite volume/continuum limit down to values below N_f \le 1.5 at
finite volumes in agreement with earlier results of Gusynin and Reenders in a
simpler truncation scheme. These findings explain discrepancies in N_f^c
between continuum and lattice studies.


title:
Central Limit Theorem and the Bootstrap for U-Statistics of Strongly
  Mixing Data

abstract:
  The asymptotic normality of U-statistics has so far been proved for iid data
and under various mixing conditions such as absolute regularity, but not for
strong mixing. We use a coupling technique introduced in 1983 by Bradley to
prove a new generalized covariance inequality similar to Yoshihara's. It
follows from the Hoeffding-decomposition and this inequality that U-statistics
of strongly mixing observations converge to a normal limit if the kernel of the
U-statistic fulfills some moment and continuity conditions.
  The validity of the bootstrap for U-statistics has until now only been
established in the case of iid data (see Bickel and Freedman). For mixing data,
Politis and Romano proposed the circular block bootstrap, which leads to a
consistent estimation of the sample mean's distribution. We extend these
results to U-statistics of weakly dependent data and prove a CLT for the
circular block bootstrap version of U-statistics under absolute regularity and
strong mixing. We also calculate a rate of convergence for the bootstrap
variance estimator of a U-statistic and give some simulation results.


title:
Bond analysis of cobalt and iron based skutterudites: elongated
  lanthanum bonds in LaFe4P12

abstract:
  Motivated by the possibility of further improving the thermoelectric
properties of skutterudites we investigate charge transfer and bonding in this
class of materials using density functional calculations. Results for the CoP3,
CoSb3, LaFe4P12 and the hypothetical FeP3 compounds are presented using the
procrystal as the non-binding reference. Spherical integration and Bader
analysis are performed to illustrate charge transfer differences between these
compounds. The results are in good qualitative agreement with simple
electronegativity considerations. The calculations confirm that the transition
metal-pnictogen and the pnictogen-pnictogen bonds are covalent, while the
filler atom-pnictogen bond is of a more polar and complex nature. The success
of the "rattling" cage as phonon inhibitor is explained by a unique
semi-correlated bonding scheme between lanthanum and phosphorus. Elongated
bonds along the crystal axes surrounds the lanthanum ion and generate a
dodecahedra grid. Vibrations along the crystal axes are then closely connected
to and scatter from the phosphorus rings. In the other directions, a more
uncorrelated vibration is possible. This duality widens the phonon dampening
possibilities.


title:
The Berry phase of dislocations in graphene and valley conserving
  decoherence

abstract:
  We demonstrate that dislocations in the graphene lattice give rise to
electron Berry phases equivalent to quantized values {0,1/3,-1/3} in units of
the flux quantum, but with an opposite sign for the two valleys. An elementary
scale consideration of a graphene Aharonov-Bohm ring equipped with valley
filters on both terminals, encircling a dislocation, says that in the regime
where the intervalley mean free path is large compared to the intravalley phase
coherence length, such that the valley quantum numbers can be regarded as
conserved on the relevant scale, the coherent valley-polarized currents
sensitive to the topological phases have to traverse the device many times
before both valleys contribute, and this is not possible at intermediate
temperatures where the latter length becomes of order of the device size, thus
leading to an apparent violation of the basic law of linear transport that
magnetoconductance is even in the applied flux. We discuss this discrepancy in
the Feynman path picture of dephasing, when addressing the transition from
quantum to classical dissipative transport. We also investigate this device in
the scattering matrix formalism, accounting for the effects of decoherence by
the Buttiker dephasing voltage probe type model which conserves the valleys,
where the magnetoconductance remains even in the flux, also when different
decoherence times are allowed for the individual, time reversal connected,
valleys.


title:
Wave patterns generated by a supersonic moving body in a binary
  Bose-Einstein condensate

abstract:
  Generation of wave structures by a two-dimensional object (laser beam) moving
in a two-dimensional two-component Bose-Einstein condensate with a velocity
greater than both sound velocities of the mixture is studied by means of
analytical methods and systematic simulations of the coupled Gross-Pitaevskii
equations. The wave pattern features three regions separated by two Mach cones.
Two branches of linear patterns similar to the so-called "ship waves" are
located outside the corresponding Mach cones, and oblique dark solitons are
found inside the wider cone. An analytical theory is developed for the linear
patterns. A particular dark-soliton solution is also obtained, its stability is
investigated, and two unstable modes of transverse perturbations are
identified. It is shown that, for a sufficiently large flow velocity, this
instability has a convective character in the reference frame attached to the
moving body, which makes the dark soliton effectively stable. The analytical
findings are corroborated by numerical simulations.


title: Nuclear effects in proton decay

abstract:
  An experimental observation of proton decay would be a spectacular proof of
grand unification. Currently, the best constraint on the proton lifetime for
the p->e+ pi0 decay channel, coming from the Super-Kamiokande experiment,
reaches 8*10^33 years. To improve the measurement, much bigger detectors should
be constructed. Moreover, a better description of the bound-nucleon states and
of the propagation of the proton-decay products through nuclear matter have to
be developed. In this article special attention is paid to the argon nucleus
because a liquid argon detector is a promising candidate for the future large
apparatus.


title:
Radio Detector Array Simulation - A Full Simulation Chain for an Array
  of Antenna Detectors

abstract:
  Recently radio signals originating from extensive air showers have been
observed at the Pierre Auger Observatory. In this note we present software to
simulate the response of an array of antenna detectors and to reconstruct the
radio signals. With this software it is possible to investigate design
parameters of an antenna array and to visualize the radio data. We show
comparisons between measurements of radio signals from air showers and
simulated data which were generated with the REAS2 generator and then processed
with the detector simulation and reconstruction software.


title:
Measurement of the magnetic field inside the holes of a drilled bulk
  high-Tc superconductor

abstract:
  We use macroscopic holes drilled in a bulk YBCO superconductor to probe its
magnetic properties in the volume of the sample. The sample is subjected to an
AC magnetic flux with a density ranging from 30mT to 130mT and the flux in the
superconductor is probed by miniature coils inserted in the holes. In a given
hole, three different penetration regimes can be observed: (i) the shielded
regime, where no magnetic flux threads the hole; (ii) the gradual penetration
regime, where the waveform of the magnetic field has a clipped sine shape whose
fundamental component scales with the applied field; and (iii) the flux
concentration regime, where the waveform of the magnetic field is nearly a sine
wave, with an amplitude exceeding that of the applied field by up to a factor
of two. The distribution of the penetration regimes in the holes is compared
with that of the magnetic flux density at the top and bottom surfaces of the
sample, and is interpreted with the help of optical polarized light micrographs
of these surfaces. We show that the measurement of the magnetic field inside
the holes can be used as a local characterization of the bulk magnetic
properties of the sample.


title: Curvature-induced frustration in the $XY$ model on hyperbolic surfaces

abstract:
  We study low-temperature properties of the $XY$ spin model on a negatively
curved surface. Geometric curvature of the surface gives rise to frustration in
local spin configuration, which results in the formation of high-energy spin
clusters scattered over the system. Asymptotic behavior of the spin-glass
susceptibility suggests a zero-temperature glass transition, which is
attributed to multiple optimal configurations of spin clusters due to nonzero
surface curvature of the system. It implies that a constant ferromagnetic spin
interaction on a regular lattice can exhibit glasslike behavior without
possessing any disorder if the lattice is put on top of a negatively curved
space such as a hyperbolic surface.


title: Binomial approximations of shortfall risk for game options

abstract:
  We show that the shortfall risk of binomial approximations of game (Israeli)
options converges to the shortfall risk in the corresponding Black--Scholes
market considering Lipschitz continuous path-dependent payoffs for both
discrete- and continuous-time cases. These results are new also for usual
American style options. The paper continues and extends the study of Kifer
[Ann. Appl. Probab. 16 (2006) 984--1033] where estimates for binomial
approximations of prices of game options were obtained. Our arguments rely, in
particular, on strong invariance principle type approximations via the
Skorokhod embedding, estimates from Kifer [Ann. Appl. Probab. 16 (2006)
984--1033] and the existence of optimal shortfall hedging in the discrete time
established by Dolinsky and Kifer [Stochastics 79 (2007) 169--195].


title: Black Hole Spins of Radio Sources

abstract:
  A new approach to constraining or determining the spin of a massive black
hole is proposed. A key parameter in the analysis is the dimensionless ratio,
r, of the energy released to the mass of the hole. It is shown that the black
hole spin, j, may be written as a function of the dimensionless ratio of the
black hole spin energy to the black hole mass. When extraction of the black
hole spin energy powers an outflow from the hole, the ratio r provides an
indication of the black hole spin. The method is applied to a sample of 19 very
powerful classical double radio galaxies with a range of size and redshift. The
sources are found to have remarkably similar values of r and j, implying that
the sources have very similar physical conditions at the time the outflow is
generated. A sample of 29 central dominant galaxies is also studied; most of
these sources have amorphous or FRI radio structure. The sources have a broad
range of ratios r, and correspondingly broad range of black hole spins. The
broad range probably results from the fact that each source is observed at a
different stage in its lifetime. The intrinsic range of parameters could be as
tight as it is for the powerful classical double radio galaxies.


title:
A novel experimental method for the measurement of the caloric curves of
  clusters

abstract:
  A novel experimental scheme has been developed in order to measure the heat
capacity of mass selected clusters. It is based on controlled sticking of atoms
on clusters. This allows one to construct the caloric curve, thus determining
the melting temperature and the latent heat of fusion in the case of
first-order phase transitions. This method is model-free. It is transferable to
many systems since the energy is brought to clusters through sticking
collisions. As an example, it has been applied to Na\_90\^+ and Na\_140\^+. Our
results are in good agreement with previous measurements.


title:
Slow conductance relaxations; Distinguishing the Electron Glass from
  extrinsic mechanisms

abstract:
  Slow conductance relaxations are observable in a many condensed matter
systems. These are sometimes described as manifestations of a glassy phase. The
underlying mechanisms responsible for the slow dynamics are often due to
structural changes which modify the potential landscape experienced by the
charge-carriers and thus are reflected in the conductance. Sluggish conductance
dynamics may however originate from the interplay between electron-electron
interactions and quenched disorder. Examples for both scenarios and the
experimental features that should help to distinguish between them are shown
and discussed. In particular, it is suggested that the `memory-dip' observable
through field-effect measurements is a characteristic signature of the inherent
electron-glass provided it obeys certain conditions.


title: Dynamic interfaces in an organic thin film

abstract:
  Low-dimensional boundaries between phases and domains in organic thin films
are important in charge transport and recombination. Here, fluctuations of
interfacial boundaries in an organic thin film, acridine-9-carboxylic acid
(ACA) on Ag(111), have been visualized in real time, and measured
quantitatively, using Scanning Tunneling Microscopy. The boundaries fluctuate
via molecular exchange with exchange time constants of 10-30 ms at room
temperature, yielding length mode fluctuations that should yield characteristic
f-1/2 signatures for frequencies less than ~100 Hz. Although ACA has highly
anisotropic intermolecular interactions, it forms islands that are compact in
shape with crystallographically distinct boundaries that have essentially
identical thermodynamic and kinetic properties . The physical basis of the
modified symmetry is shown to arise from significantly different substrate
interactions induced by alternating orientations of successive molecules in the
condensed phase. Incorporating this additional set of interactions in a lattice
gas model leads to effective multi-component behavior, as in the
Blume-Emery-Griffiths (BEG) model, and can straightforwardly reproduce the
experimentally observed isotropic behavior. The general multi-component
description allows the domain shapes and boundary fluctuations to be tuned from
isotropic to highly anisotropic in terms of the balance between intermolecular
interactions and molecule-substrate interactions. Key words: Organic thin film,
fluctuations, STM, molecular interactions, diffusion kinetics, phase
coexistence


title: Non-holonomic Constraints and the Principle of Extremal Curvature

abstract: This paper has been withdrawn by the author(s)


title:
Equality of critical points for polymer depinning transitions with loop
  exponent one

abstract:
  We consider a polymer with configuration modelled by the trajectory of a
Markov chain, interacting with a potential of form $u+V_n$ when it visits a
particular state 0 at time $n$, with $\{V_n\}$ representing i.i.d. quenched
disorder. There is a critical value of $u$ above which the polymer is pinned by
the potential. A particular case not covered in a number of previous studies is
that of loop exponent one, in which the probability of an excursion of length
$n$ takes the form $\phi(n)/n$ for some slowly varying $\phi$; this includes
simple random walk in two dimensions. We show that in this case, at all
temperatures, the critical values of $u$ in the quenched and annealed models
are equal, in contrast to all other loop exponents, for which these critical
values are known to differ, at least at low temperatures.


title: Magnetic coronae of active main-sequence stars

abstract:
  The coronal structure of main sequence stars continues to puzzle us. While
the solar corona is relatively well understood, it has become clear that even
stars of the same mass as the Sun can display very non-solar coronal behaviour,
particularly if they are rapid rotators or in a binary system. At masses
greater than and also less than that of the Sun, the non-solar internal
structure appears to affect both the geometry and dynamics of the stellar
corona and the nature of the X-ray and radio emission. In this talk I will
describe some recent advances in our understanding of the structure of the
coronae of some of the most active (and interesting) main sequence stars.


title: On conformal field theories with low number of primary fields

abstract:
  Using Verlinde formula and the symmetry of the modular matrix we describe an
algorithm to find all conformal field theories with low number of primary
fields. We employ the algorithm on up to eight primary fields. Four new
conformal field theories are found which do not appear to come from current
algebras. This supports evidence to the fact that rational conformal field
theories are far richer than suspected before.


title: Time in relativistic and nonrelativistic quantum mechanics

abstract:
  The kinematic time operator can be naturally defined in relativistic and
nonrelativistic quantum mechanics (QM) by treating time on an equal footing
with space. The spacetime-position operator acts in the Hilbert space of
functions of space and time. Dynamics, however, makes eigenstates of the time
operator unphysical. This poses a problem for the standard interpretation of QM
and reinforces the role of alternative interpretations such as the Bohmian one.
The Bohmian interpretation, despite of being nonlocal in accordance with the
Bell theorem, is shown to be relativistic covariant.


title: Stellar mass ejections

abstract:
  It has been known for some time now that rapidly-rotating solar-like stars
possess the stellar equivalent of solar prominences. These may be three orders
of magnitude more massive than their solar counterparts, and their ejection
from the star may form a significant contribution to the loss of angular
momentum and mass in the stellar wind. In addition, their number and
distribution provide valuable clues as to the structure of the stellar corona
and hence to the nature of magnetic activity in other stars.
  Until recently, these "slingshot prominences" had only been observed in
mature stars, but their recent detection in an extremely young star suggests
that they may be more widespread than previously thought. In this review I will
summarise our current understanding of these stellar prominences, their
ejection from their stars and their role in elucidating the (sometimes very
non-solar) behaviour of stellar magnetic fields.


title:
The genesis of morphologies in extended radio sources: X-shapes,
  off-axis distortions and giant radio sources

abstract:
  We examine relationships between the morphology in double radio sources and
the radio-optical position angle offset--the relative orientation of the radio
axis with respect to the major axis of the host galaxy. The study was done for
a representative sample of radio sources: the nearby (redshift z < 0.5) 3CRR
sources, and separately for samples of giant radio sources and X-shaped radio
sources. We find that radio morphological features have a dependence on the
radio-optical position angle offset and on whether the source is a major- or
minor-axis source. The evidence indicates an anisotropic galaxy environment,
related to the ellipticity of the host galaxy, that causes the source linear
size evolution, strength of backflow in the radio lobes, off-axis lobe
distortions and the formation of wings and X-shaped radio sources to depend on
the radio-optical position angle offset. We identify a class of X-shaped radio
sources, which are either edge-darkened or lacking hotspots, and appear to have
inner doubles suggesting a restarting of activity. We suggest a common
formation mechanism, requiring backflows, for these apparently FR-I X-shaped
radio sources as well as the edge-brightened X-shaped sources.


title:
Nonlinear stability of self-similar solutions for semilinear wave
  equations

abstract:
  We prove nonlinear stability of the fundamental self--similar solution of the
wave equation with a focusing power nonlinearity $\psi_{tt}-\Delta \psi=\psi^p$
for $p=3,5,7,...$ in the radial case. The proof is based on a semigroup
formulation of the wave equation in similarity coordinates.


title: Superconformal indices for N=1 theories with multiple duals

abstract:
  Following a recent work of Dolan and Osborn, we consider superconformal
indices of four dimensional ${\mathcal N}=1$ supersymmetric field theories
related by an electric-magnetic duality with the SP(2N) gauge group and fixed
rank flavour groups. For the SP(2) (or SU(2)) case with 8 flavours, the
electric theory has index described by an elliptic analogue of the Gauss
hypergeometric function constructed earlier by the first author. Using the
$E_7$-root system Weyl group transformations for this function, we build a
number of dual magnetic theories. One of them was originally discovered by
Seiberg, the second model was built by Intriligator and Pouliot, the third one
was found by Cs\'aki et al. We argue that there should be in total 72 theories
dual to each other through the action of the coset group $W(E_7)/S_8$. For the
general $SP(2N), N>1,$ gauge group, a similar multiple duality takes place for
slightly more complicated flavour symmetry groups. Superconformal indices of
the corresponding theories coincide due to the Rains identity for a
multidimensional elliptic hypergeometric integral associated with the
$BC_N$-root system.


title:
Solitons with Cubic and Quintic Nonlinearities Modulated in Space and
  Time

abstract:
  This work deals with soliton solutions of the nonlinear Schroedinger equation
with cubic and quintic nonlinearities. We extend the procedure put forward in a
recent Letter and we solve the equation in the presence of linear background,
and cubic and quintic interactions which are modulated in space and time. As a
result, we show how a simple parameter can be used to generate brightlike or
darklike localized nonlinear waves which oscillate in several distinct ways,
driven by the space and time dependence of the parameters that control the
trapping potential, and the cubic and quintic nonlinearities.


title: On factorization scheme suitable for NLO Monte Carlo event generators

abstract:
  The choice of a factorization scheme suitable for Monte Carlo simulations of
NLO initial state parton showers is discussed in this contribution.


title: Mass Distributions Beyond TDHF

abstract:
  The mass distributions for giant dipole resonances in 32S and 132Sn decaying
through particle emission and for deep-inelastic collisions between 16O nuclei
have been investigated by implementing the Balian-Veneroni variational
technique based upon a three-dimensional time-dependent Hartree-Fock code with
realistic Skyrme interactions. The mass distributions obtained have been shown
to be significantly larger than the standard TDHF results.


title: Scanning Quantum Decoherence Microscopy

abstract:
  The use of qubits as sensitive magnetometers has been studied theoretically
and recent demonstrated experimentally. In this paper we propose a
generalisation of this concept, where a scanning two-state quantum system is
used to probe the subtle effects of decoherence (as well as its surrounding
electromagnetic environment). Mapping both the Hamiltonian and decoherence
properties of a qubit simultaneously, provides a unique image of the magnetic
(or electric) field properties at the nanoscale. The resulting images are
sensitive to the temporal as well as spatial variation in the fields created by
the sample. As an example we theoretically study two applications of this
technology; one from condensed matter physics, the other biophysics. The
individual components required to realise the simplest version of this device
(characterisation and measurement of qubits, nanoscale positioning) have
already been demonstrated experimentally.


title: A TLA+ Proof System

abstract:
  We describe an extension to the TLA+ specification language with constructs
for writing proofs and a proof environment, called the Proof Manager (PM), to
checks those proofs. The language and the PM support the incremental
development and checking of hierarchically structured proofs. The PM translates
a proof into a set of independent proof obligations and calls upon a collection
of back-end provers to verify them. Different provers can be used to verify
different obligations. The currently supported back-ends are the tableau prover
Zenon and Isabelle/TLA+, an axiomatisation of TLA+ in Isabelle/Pure. The proof
obligations for a complete TLA+ proof can also be used to certify the theorem
in Isabelle/TLA+.


title: The many vacua of gauged extended supergravities

abstract:
  A novel method is presented which employs advanced numerical techniques used
in the engineering sciences to find and study the properties of nontrivial
vacua of gauged extended supergravity models. While this method only produces
approximate numerical data rather than analytic results, it overcomes the
previous limitation of only being able to find vacua with large residual
unbroken gauge symmetry groups. The effectiveness of this method is
demonstrated by applying it to the technically most challenging D>=3 scalar
potential -- that of SO(8) X SO(8) gauged N=16 Chern-Simons Supergravity in
D=3. Extensive data on the properties of 99 different vacua (92 of them new) of
this model are given. Furthermore, techniques are briefly discussed which
should allow using this numerical information as an input to the construction
of semi-automatic stringent analytic proofs on the locations and properties of
vacua. It hence is argued that these combined techniques presumably are
powerful enough to systematically map all the nontrivial vacua of every
supergravity model.


title: Towards Loop Quantum Gravity without the time gauge

abstract:
  The Hamiltonian formulation of the Holst action is reviewed and it is
provided a solution of second-class constraints corresponding to a generic
local Lorentz frame. Within this scheme the form of rotation constraints can be
reduced to a Gauss-like one by a proper generalization of
Ashtekar-Barbero-Immirzi connections. This result emphasizes that the Loop
Quantum Gravity quantization procedure can be applied when the time-gauge
condition does not stand.


title: Aggregation of autoregressive processes and long memory

abstract:
  We study the aggregation of AR processes and generalized Ornstein-Uhlenbeck
(OU) processes. Mixture of spectral densities with random poles are the main
tool. In this context, we apply our results for the aggregation of doubly
stochastic interactives processes, see Dacunha-Castelle and Fermin (2006).
Thus, we study the relationship between aggregation of autoregressive processes
and long memory considering complex interaction structures. We precise a very
interesting qualitative phenomena: how the long memory creation depends on the
poles concentration near to the boundary of stability (measured in the
Prokhorov sense). Our results extends the results given by Oppenheim and Viano
(2004), and highlight the importance of the angular dispersion measure of poles
in the appearance of the long memory.


title:
Interplay of the emission from thermal and direct sources in
  relativistic heavy ion collisions

abstract:
  The separation of the source created in ultrarelativistic heavy-ion
collisions into a thermalized dense core and an outer mantle consisting of
independent nucleon-nucleon collisions is discussed. Evidence for such a two
component picture is found in transverse mass spectra of kaon, protons and
antiprotons produced in Au-Au collisions at 200GeV. Estimates of the sizes of
the thermal and direct sources are compared to models separating the
interaction zone into a core and a corona, according to the density of
participants or to the number of collisions. Consequences for the modeling of
the dynamics of the small size, thermalized core are described. New initial
conditions corresponding to the dense core lead to a stronger azimuthal
asymmetry of the hydrodynamically expanding fireball, pressure gradients also
increase. 2+1-dimensional hydrodynamic simulations are presented starting from
all the matter in the interaction region or from the dense, thermal part of the
source. We find faster transverse expansion and stronger elliptic flow for
dense core initial conditions. For different impact parameters we find very
similar spectra of the thermal part of the source and only adding particles
emitted directly from nucleon-nucleon collisions in the corona the
experimentally observed softening of the spectra with increasing impact
parameter is reproduced. The elliptic flow is stronger for particles emitted
from a source separated into a core and a corona.


title: Air Shower Measurements with the LOPES Radio Antenna Array

abstract:
  LOPES is set up at the location of the KASCADE-Grande extensive air shower
experiment in Karlsruhe, Germany and aims to measure and investigate radio
pulses from Extensive Air Showers. Since radio waves suffer very little
attenuation, radio measurements allow the detection of very distant or highly
inclined showers. These waves can be recorded day and night, and provide a
bolometric measure of the leptonic shower component. LOPES is designed as a
digital radio interferometer using high bandwidths and fast data processing and
profits from the reconstructed air shower observables of KASCADE-Grande. The
LOPES antennas are absolutely amplitude calibrated allowing to reconstruct the
electric field strength which can be compared with predictions from detailed
Monte Carlo simulations. We report about the analysis of correlations present
in the radio signals measured by the LOPES 30 antenna array. Additionally,
LOPES operates antennas of a different type (LOPES-STAR) which are optimized
for an application at the Pierre Auger Observatory. Status, recent results of
the data analysis and further perspectives of LOPES and the possible large
scale application of this new detection technique are discussed.


title:
Identifying Decaying Supermassive Black Hole Binaries from their
  Variable Electromagnetic Emission

abstract:
  Supermassive black hole binaries (SMBHBs) with masses in the range 10^4-10^7
M_sun/(1+z), produced in galaxy mergers, are thought to complete their
coalescence due to the emission of gravitational waves (GWs). The anticipated
detection of the GWs by the LISA will constitute a milestone for fundamental
physics and astrophysics. While the GW signatures themselves will provide a
treasure trove of information, if the source can be securely identified in
electromagnetic (EM) bands, this would open up entirely new scientific
opportunities, to probe fundamental physics, astrophysics, and cosmology. We
discuss several ideas, involving wide-field telescopes, that may be useful in
locating electromagnetic counterparts to SMBHBs detected by LISA. In
particular, the binary may produce a variable electromagnetic flux, such as a
roughly periodic signal due to the orbital motion prior to coalescence, or a
prompt transient signal caused by shocks in the circumbinary disk when the
SMBHB recoils and "shakes" the disk. We discuss whether these time-variable EM
signatures may be detectable, and how they can help in identifying a unique
counterpart within the localization errors provided by LISA. We also discuss a
possibility of identifying a population of coalescing SMBHBs statistically, in
a deep optical survey for periodically variable sources, before LISA detects
the GWs directly. The discovery of such sources would confirm that gas is
present in the vicinity and is being perturbed by the SMBHB - serving as a
proof of concept for eventually finding actual LISA counterparts.


title:
Symmetry-Breaking and Symmetry-Restoring Dynamics of a Mixture of
  Bose-Einstein Condensates in a Double Well

abstract:
  We study the coherent nonlinear tunneling dynamics of a binary mixture of
Bose-Einstein condensates in a double-well potential. We demonstrate the
existence of a new type of mode associated with the "swapping" of the two
species in the two wells of the potential. In contrast to the symmetry breaking
macroscopic quantum self-trapping (MQST) solutions, the swapping modes
correspond to the tunneling dynamics that preserves the symmetry of the double
well potential. As a consequence of two distinct types of broken symmetry MQST
phases where the two species localize in the different potential welils or
coexist in the same well, the corresponding symmetry restoring swapping modes
result in dynamics where the the two species either avoid or chase each other.
In view of the possibility to control the interaction between the species, the
binary mixture offers a very robust system to observe these novel effects as
well as the phenomena of Josephson oscillations and pi-modes


title: A Hypergraph Dictatorship Test with Perfect Completeness

abstract:
  A hypergraph dictatorship test is first introduced by Samorodnitsky and
Trevisan and serves as a key component in their unique games based $\PCP$
construction. Such a test has oracle access to a collection of functions and
determines whether all the functions are the same dictatorship, or all their
low degree influences are $o(1).$ Their test makes $q\geq3$ queries and has
amortized query complexity $1+O(\frac{\log q}{q})$ but has an inherent loss of
perfect completeness. In this paper we give an adaptive hypergraph dictatorship
test that achieves both perfect completeness and amortized query complexity
$1+O(\frac{\log q}{q})$.


title:
Electrohydrodynamic model of vesicle deformation in alternating electric
  fields

abstract:
  We develop an analytical theory to explain the experimentally-observed
morphological transitions of giant vesicles induced by AC electric fields (1).
The model treats the inner and suspending media as lossy dielectrics, while the
membrane as an ion-impermeable flexible incompressible-fluid sheet. The vesicle
shape is obtained by balancing electric, hydrodynamic, and bending stresses
exerted on the membrane. Considering a nearly spherical vesicle, the solution
to the electrohydrodynamic problem is obtained as a regular perturbation
expansion in the excess area.
  The theory predicts that stationary vesicle deformation depends on field
frequency and conductivity conditions. If the inner fluid is more conducting
than the suspending medium, the vesicle always adopts a prolate shape. In the
opposite case, the vesicle undergoes a transition from a prolate to oblate
ellipsoid at a critical frequency, which the theory identifies with the inverse
membrane charging time. At frequencies higher than the inverse Maxwell-Wagner
polarization time, the electrohydrodynamic stresses become too small to alter
the vesicle's quasi-spherical rest shape. The analysis shows that the evolution
towards the stationary vesicle deformation strongly depends on membrane
properties such as viscosity. The model can be applied to rationalize the
transient and steady deformation of biological cells in electric fields.


title:
Effect of doping-- and field--induced charge carrier density on the
  electron transport in nanocrystalline ZnO

abstract:
  Charge transport properties of thin films of sol--gel processed undoped and
Al-doped zinc oxide nanoparticles with variable doping level between 0.8 at%
and 10 at% were investigated. The X-ray diffraction studies revealed a decrease
of the average crystallite sizes in highly doped samples. We provide estimates
of the conductivity and the resulting charge carrier densities with respect to
the doping level. The increase of charge carrier density due to extrinsic
doping were compared to the accumulation of charge carriers in field effect
transistor structures. This allowed to assess the scattering effects due to
extrinsic doping on the electron mobility. The latter decreases from 4.6*10^-3
cm^2/Vs to 4.5*10^-4 cm^2/Vs with increasing doping density. In contrast, the
accumulation leads to an increasing mobility up to 1.5*10^-2 cm^2/Vs. The
potential barrier heights related to grain boundaries between the crystallites
were derived from temperature dependent mobility measurements. The extrinsic
doping initially leads to a grain boundary barrier height lowering, followed by
an increase due to doping-induced structural defects. We conclude that the
conductivity of sol--gel processed nanocrystalline ZnO:Al is governed by an
interplay of the enhanced charge carrier density and the doping-induced charge
carrier scattering effects, achieving a maximum at 0.8 at% in our case.


title: Enumeration of derangements with descents in prescribed positions

abstract:
  We enumerate derangements with descents in prescribed positions. A generating
function was given by Guo-Niu Han and Guoce Xin in 2007. We give a
combinatorial proof of this result, and derive several explicit formulas. To
this end, we consider fixed point $\lambda$-coloured permutations, which are
easily enumerated. Several formulae regarding these numbers are given, as well
as a generalisation of Euler's difference tables. We also prove that except in
a trivial special case, if a permutation $\pi$ is chosen uniformly among all
permutations on $n$ elements, the events that $\pi$ has descents in a set $S$
of positions, and that $\pi$ is a derangement, are positively correlated.


title:
The physics of the relativistic counter-streaming instability that
  drives mass inflation inside black holes

abstract:
  If you fall into a real astronomical black hole (choosing a supermassive
black hole, to make sure that the tidal forces don't get you first), then you
will probably meet your fate not at a central singularity, but rather in the
exponentially growing, relativistic counter-streaming instability at the inner
horizon first pointed out by Poisson & Israel (1990), who called it mass
inflation. The chief purpose of this paper is to present a clear exposition of
the physical cause and consequence of inflation in spherical, charged black
holes. Inflation acts like a particle accelerator in that it accelerates cold
ingoing and outgoing streams through each other to prodigiously high energies.
Inflation feeds on itself: the acceleration is powered by the gravity produced
by the streaming energy. The paper: (1) uses physical arguments to develop
simple approximations that follow the evolution of inflation from ignition,
through inflation itself, to collapse; (2) confirms that the simple
approximations capture accurately the results of fully nonlinear one- and
two-fluid self-similar models; (3) demonstrates that, counter-intuitively, the
smaller the accretion rate, the more rapidly inflation exponentiates; (4) shows
that in single perfect-fluid models, inflation occurs only if the sound speed
equals the speed of light, supporting the physical idea that inflation in
single fluids is driven by relativistic counter-streaming of waves; (5) shows
that what happens during inflation up to the Planck curvature depends not on
the distant past or future, but rather on events happening only a few hundred
black hole crossing times into the past or future; (6) shows that, if quantum
gravity does not intervene, then the generic end result of inflation is not a
general relativistic null singularity, but rather a spacelike singularity at
zero radius.


title: Optimal protocol for quantum state tomography

abstract:
  We develop a practical quantum tomography protocol and implement measurements
of pure states of ququarts realized with polarization states of photon pairs
(biphotons). The method is based on an optimal choice of the measuring scheme's
parameters that provides better quality of reconstruction for the fixed set of
statistical data. A high accuracy of the state reconstruction (above 0.99)
indicates that developed methodology is adequate.


title: Asymmetric simple exclusion process with periodic boundary driving

abstract:
  We consider the asymmetric simple exclusion process (ASEP) on a semi-infinite
chain which is coupled at the end to a reservoir with a particle density that
changes periodically in time. It is shown that the density profile assumes a
time-periodic sawtooth-like shape. This shape does not depend on initial
conditions and is found analytically in the hydrodynamic limit. In a finite
system, the stationary state is shown to be governed by effective boundary
densities and the extremal flux principle. Effective boundary densities are
determined numerically via Monte Carlo simulations and compared with those
given by mean field approach and numerical integration of the hydrodynamic
limit equation which is the Burgers equation. Our results extend
straightforwardly beyond the ASEP to a wide class of driven diffusive systems
with one conserved particle species.


title: Precision Kaon and Hadron Physics with KLOE

abstract:
  We describe the KLOE detector at DAFNE, and its physics program. The impact
of our results on flavor and hadron physics to date, as well as an outlook for
further improvement in the near future, are discussed.


title:
Determinants in the Kronecker product of matrices: The incidence matrix
  of a complete graph

abstract:
  We investigate the least common multiple of all subdeterminants, lcmd(A x B),
of a Kronecker product of matrices, of which one is an integral matrix A with
two columns and the other is the incidence matrix of a complete graph with n
vertices. We prove that this quantity is the least common multiple of lcmd(A)
to the power n-1 and certain binomial functions of the entries of A.


title: Revisiting strong coupling QCD at finite temperature and baryon density

abstract:
  The strong coupling limit ($\beta_{gauge}=0$) of lattice QCD with staggered
fermions enjoys the same non-perturbative properties as continuum QCD, namely
confinement and chiral symmetry breaking. In contrast to the situation at weak
coupling, the sign problem which appears at finite density can be brought under
control for a determination of the full (mu,T) phase diagram by Monte Carlo
simulations. Further difficulties with efficiency and ergodicity of the
simulations, especially at the strongly first-order, low-T, finite-mu
transition, are addressed respectively with a worm algorithm and multicanonical
sampling. Our simulations reveal sizeable corrections to the old results of
Karsch and Muetter. Comparison with analytic mean-field determinations of the
phase diagram shows discrepancies of O(10) in the location of the QCD critical
point.


title:
Nonuniqueness of gravity-induced fermion interaction in the
  Einstein-Cartan theory

abstract:
  The problem of nonuniqueness of minimal coupling procedure for
Einstein--Cartan (EC) gravity with matter is investigated. It is shown that the
predictions of the theory of gravity with fermionic matter can radically change
if the freedom of addition of a divergence to the flat space matter Lagrangean
density is exploited. The well--known gravity induced four--fermion interaction
is shown to reveal unexpected features. The solution to the problem of
nonuniqueness of minimal coupling of EC gravity is argued to be necessary in
order for the theory to produce definite predictions. In particular, the EC
theory with fermions is shown to be indistinguishable from usual General
Relativity on the effective level, if the flat space fermionic Lagrangean is
appropriately chosen. Hence, the solution to the problem of nonuniqueness of
minimal coupling procedure is argued to be necessary if EC theory is to be
experimentally verifiable. It could also enable experimental tests of theories
based on EC, such as loop approach to quantisation of gravitational field. Some
ideas of how the arbitrariness incorporated in EC theory could be restricted or
even eliminated are presented.


title:
Space-Dependent Step Features: Transient Breakdown of Slow-roll,
  Homogeneity and Isotropy During Inflation

abstract:
  A step feature in the inflaton potential can model a transient breakdown of
slow-roll inflation. Here we generalize the step feature to include
space-dependence, allowing it also to model a breakdown of homogeneity and
isotropy. The space-dependent inflaton potential generates a classical
curvature perturbation mode characterized by the wavenumber of the step
inhomogeneity. For inhomogeneities small compared with the horizon at the step,
space-dependence has a small effect on the curvature perturbation. Therefore
the smoothly oscillating quantum power spectrum predicted by the homogeneous
step is robust with respect to sub-horizon space-dependence. For
inhomogeneities equal to or greater than the horizon at the step, the
space-dependent classical mode can dominate, producing a curvature perturbation
in which modes of wavenumber determined by the step inhomogeneity are
superimposed on the oscillating power spectrum. Generation of a space-dependent
step feature may therefore provide a mechanism to introduce primordial
anisotropy into the curvature perturbation. Space-dependence also modifies the
quantum fluctuations, in particular via resonance-like features coming from
mode coupling to amplified superhorizon modes. However these effects are small
relative to the classical modes.


title: The \infty eigenvalue problem and a problem of optimal transportation

abstract:
  The so-called eigenvalues and eigenfunctions of the infinite Laplacian
$\Delta_\infty$ are defined through an asymptotic study of that of the usual
$p$-Laplacian $\Delta_p$, this brings to a characterization via a non-linear
eigenvalue problem for a PDE satisfied in the viscosity sense. In this paper,
we obtain an other characterization of the first eigenvalue via a problem of
optimal transportation, and recover properties of the first eigenvalue and
corresponding positive eigenfunctions.


title: An Elementary Proof of Hawkes's Conjecture on Galton-Watson Trees

abstract:
  In 1981, J. Hawkes conjectured the exact form of the Hausdorff gauge function
for the boundary of supercritical Galton-Watson trees under a certain
assumption on the tail at the infinity of the total mass of the branching
measure. Hawkes's conjecture has been proved by T. Watanabe in 2007 as well as
other other precise results on fractal properties of the boundary of
Galton-Watson trees. The goal of this paper is to provide an elementary proof
of Hawkes's conjecture under a less restrictive assumption than in T.
Watanabe's paper, by use of size-biased Galton-Watson trees introduced by
Lyons, Pemantle and Peres in 1995.


title:
Semiclassical investigation of revival phenomena in one dimensional
  system

abstract:
  In a quantum revival, a localized wavepacket re-forms or "revives" into a
compact reincarnation of itself long after it has spread in an unruly fashion
over a region restricted only by the potential energy. This is a purely quantum
phenomenon, which has no classical analog. Quantum revival, and Anderson
localization, are members of a small class of subtle interference effects
resulting in a quantum distribution radically different from the classical
after long time evolution under classically nonlinear evolution. However it is
not clear that semiclassical methods, which start with the classical density
and add interference effects, are in fact capable of capturing the revival
phenomenon. Here we investigate two different one dimensional systems, the
infinite square well and Morse potential. In both cases, after a long time the
underlying classical manifolds are spread rather uniformly over phase space and
are correspondingly spread in coordinate space, yet the semiclassical
amplitudes are able to destructively interfere over most of coordinate space
and constructively interfere in a small region, correctly reproducing a quantum
revival. Further implications of this ability are discussed.


title: Diffusive Transport in Quasi-2D and Quasi-1D Electron Systems

abstract:
  Quantum-confined semiconductor structures are the cornerstone of modern-day
electronics. Spatial confinement in these structures leads to formation of
discrete low-dimensional subbands. At room temperature, carriers transfer among
different states due to efficient scattering with phonons, charged impurities,
surface roughness and other electrons, so transport is scattering-limited
(diffusive) and well described by the Boltzmann transport equation. In this
review, we present the theoretical framework used for the description and
simulation of diffusive electron transport in quasi-two-dimensional and
quasi-one-dimensional semiconductor structures. Transport in silicon MOSFETs
and nanowires is presented in detail.


title:
Competition of breakup and dissipative processes in peripheral
  collisions at Fermi energies

abstract:
  Heavy ion collisions in the Fermi energy regime may simultaneously show
features of direct and dissipative processes. To investigate this behavior in
detail, we study isotope and velocity distributions of projectile-like
fragments in the reactions $^{18}$O (35 $A\cdot$MeV) + $^9$Be($^{181}$Ta) at
forward angles. We decompose the experimental velocity distributions
empirically into two contributions: a direct, `breakup' component centered at
beam velocity and a dissipative component at lower velocities leading to a tail
of the velocity distributions. The direct component is interpreted in the
Goldhaber model, and the widths of the velocity distributions are extracted.
The dissipative component is then successfully described by transport
calculations. The ratio of the yields of the direct and the dissipative
contributions can be understood from the behavior of the deflection functions.
The isotope distributions of the dissipative component agree qualitatively with
the data, but the modification due to secondary de-excitation needs to be
considered. We conclude, that such reactions are of interest to study the
equilibration mechanism in heavy ion collisions.


title: Optimum and equilibrium in a transport problem with queue effects

abstract:
  Consider a distribution of citizens in an urban area in which some services
(supermarkets, post offices...) are present. Each citizen, in order to use a
service, spends an amount of time which is due both to the travel time to the
service and to the queue time waiting in the service. The choice of the service
to be used is made by every citizen in order to be served more quickly. Two
types of problems can be considered: a global optimization of the total time
spent by the citizens of the whole city (we define a global optimum and we
study it with techniques from optimal mass transportation) and an individual
optimization, in which each citizen chooses the service trying to minimize just
his own time expense (we define the concept of equilibrium and we study it with
techniques from game theory). In this framework we are also able to exhibit two
time-dependent strategies (based on the notions of prudence and memory
respectively) which converge to the equilibrium.


title:
Progress Towards A Permanent Octupole Magnetic Ultra-Cold Neutron Trap
  for Lifetime Measurements

abstract:
  The current knowledge of the neutron $\beta$-decay lifetime has come under
scrutiny as of late due to large disagreements between recent precise
measurements. Measurements using magnetically trapped Ultra-Cold Neutrons
(UCNs) offer the possibility of storage without spurious losses which can
provide a reliable value for the neutron lifetime. The progress towards
realizing a neutron lifetime measurement using a Ioffe-type trap made with a
Halbach-type permanent octupole magnet is presented here. The experimental
procedure extracts a gas of UCNs into vacuum, which reduces many known channels
of neutron losses, and detects the neutron decays via in-situ detection of the
produced protons.


title:
Nature of the axial-vector mesons from their Nc behavior within the
  chiral unitary approach

abstract:
  By describing within the chiral unitary approach the s-wave interaction of
the vector meson nonet with the octet of pseudoscalar Goldstone Bosons, we find
that the main component of the axial vector mesons b_1(1235), h_1(1170),
h_1(1380), a_1(1260), f_1(1285) and the two states associated to the K_1(1270)
does not follow the QCD dependence on the number of colors for ordinary qqbar
mesons.