title: Investigation of Bioglass-Electrode Interfaces after Thermal Poling

abstract:
  Electrical and electrochemical processes in a bioactive soda-lime
phosphosilicate glasses and in a bioabsorbable soda-lime phosphate glass during
thermal poling were studied by means of thermally stimulated depolarization
current measurements, ac impedance spectroscopy, and SEM/EDX analyses. The
thermal poling was done by sputtering thin Pt electrode films onto the faces of
the glass samples and by applying voltages up to 1 kV to the electrodes at
temperatures up to 513 K. The poling leads to the formation of interfacial
layers under the electrodes which are responsible for two depolarization
current peaks and for one additional semicircle in a Nyquist plot of the ac
impedance. The SEM/EDX profiles suggest that redox and transport processes of
Na+ ions are responsible for the formation of the interfacial layers and that
Ca2+ ions are immobile under the poling conditions. The sodium depletion layer
under the anode leads to a negative surface charge of the glass samples which
may enhance their bioactivity.


title: Quadratic supersymmetric transformations of the Dirac Green functions

abstract:
  We consider the quadratic supersymmetric aspect of the Darboux transformation
for the Green functions of the one-dimensional Dirac equation with a
generalized form of the potential. We obtain the relation between the initial
and the transformed Green functions on the whole real line. We also construct
the formula for the unabridged trace of the difference of the transformed and
the initial Green functions of the boundary problem on the whole real line. We
present an example illustrated our developments.


title:
Exchange between deep donors in semiconductors: a quantum defect
  approach

abstract:
  Exchange interactions among defects in semiconductors are commonly treated
within effective-mass theory using a scaled hydrogenic wave-function. However
such a wave-function is only applicable to shallow impurities; here we present
a simple but robust generalization to treat deep donors, in which we treat the
long-range part of the wavefunction using the well established quantum defect
theory, and include a model central-cell correction to fix the bound-state
eigenvalue at the experimentally observed value. This allows us to compute the
effect of binding energy on exchange interactions as a function of donor
distance; this is a significant quantity given recent proposals to carry out
quantum information processing using deep donors. As expected, exchange
interactions are suppressed (or increased), compared to the hydrogenic case, by
the greater localization (or delocalization) of the wavefunctions of deep
donors (or `super-shallow' donors with binding energy less then the hydrogenic
value). The calculated results are compared with a simple scaling of the
Heitler-London hydrogenic exchange; the scaled hydrogenic results give the
correct order of magnitude but fail to reproduce quantitatively our
calculations. We calculate the donor exchange in silicon including inter-valley
interference terms for donor pairs along the $\{100\}$ direction, and also show
the influence of the donor type on the distribution of nearest-neighbour
exchange constants at different concentrations. Our methods can be used to
compute the exchange interactions between two donor electrons with arbitrary
binding energy.


title: Strange non-chaotic attractors in quasiperiodically forced circle maps

abstract:
  The occurrence of strange non-chaotic attractors (SNA) in quasiperiodically
forced systems has attracted considerable interest over the last two decades,
in particular since it provides a rich class of examples for the possibility of
complicated dynamics in the absence of chaos. Their existence was discovered in
the early 1980's, independently by Herman for quasiperiodic SL(2,R)-cocycles
and by Grebogi et al for so-called 'pinched skew products'. However, except for
these two particular classes there are still hardly any rigorous results on the
topic, despite a large number of numerical studies which all confirmed the
widespread existence of SNA in quasiperiodically forced systems.
  Here, we prove the existence of SNA in quasiperiodically forced circle maps
under rather general conditions, which can be stated in terms of C 1
-estimates. As a consequence, we obtain the existence of strange non-chaotic
attractors for parameter sets of positive measure in suitable parameter
families. Further, we show that the considered systems have minimal dynamics.
The results apply in particular to a forced version of the Arnold circle map.
For this particular example, we also describe how the first Arnold tongue
collapses and looses its regularity due to the presence of strange non-chaotic
attractors and a related unbounded mean motion property.


title: X-ray reflection in accreting stellar-mass black hole systems

abstract:
  The X-ray spectra of accreting stellar-mass black hole systems exhibit
spectral features due to reflection, especially broad iron K alpha emission
lines. We investigate the reflection by the accretion disc that can be expected
in the high/soft state of such a system. First, we perform a self-consistent
calculation of the reflection that results from illumination of a hot, inner
portion of the disc with its atmosphere in hydrostatic equilibrium. Then we
present reflection spectra for a range of illumination strengths and disc
temperatures under the assumption of a constant-density atmosphere. Reflection
by a hot accretion disc differs in important ways from that of a much cooler
disc, such as that expected in an active galactic nucleus.


title:
Quantum Critical Phenomena, Entanglement Entropy and Hubbard Model in 1d
  with the Boundary Site with a Negative Chemical Potential -p and the Hubbard
  Coupling U Positive

abstract:
  Recently the ground state and some excited states of the half-filled case of
the 1d Hubbard model were discussed for an open chain with L sites. Authors
considered the case when the boundary site has a negative chemical potential -p
and the Hubbard coupling U is positive. They have shown by an analytic method
that when p is larger than the transfer integral some of the ground-state
solutions of the Bethe ansatz equations become complex-valued. They have found
that there is a surface phase transition at some critical value p_c; when p <
p_c all the charge excitations have the gap for this case, while there exists a
massless charge mode when p > p_c. To find whether this surface phase
transition is of the first order or of the second order we have used the
entanglement entropy concept. The entropy and its derivative has a
discontinuity there, so this transition is of the first order.


title: Strong Law of Large Numbers for branching diffusions

abstract:
  Let $X$ be the branching particle diffusion corresponding to the operator
  $Lu+\beta (u^{2}-u)$ on $D\subseteq \mathbb{R}^{d}$
  (where $\beta \geq 0$ and $\beta\not\equiv 0$). Let $\lambda_{c}$ denote the
generalized principal eigenvalue for the operator $L+\beta $ on $D$ and assume
that it is finite. When $\lambda_{c}>0$ and $L+\beta-\lambda_{c}$ satisfies
certain spectral theoretical conditions, we prove that the random measure $\exp
\{-\lambda_{c}t\}X_{t}$ converges almost surely in the vague topology as $t$
tends to infinity. This result is motivated by a cluster of articles due to
Asmussen and Hering dating from the mid-seventies as well as the more recent
work concerning analogous results for superdiffusions of \cite{ET,EW}. We
extend significantly the results in \cite{AH76,AH77} and include some key
examples of the branching process literature. As far as the proofs are
concerned, we appeal to modern techniques concerning martingales and `spine'
decompositions or `immortal particle pictures'.


title: Chemical evolution of Seyfert galaxies

abstract:
  We computed the chemical evolution of Seyfert galaxies, residing in spiral
bulges, based on an updated model for the Milky Way bulge with updated
calculations of the Galactic potential and of the feedback from the central
supermassive black hole (BH) in a spherical approximation. We followed the
evolution of bulges of masses $2\times 10^{9}-10^{11}M_{\odot}$ by scaling the
star-formation efficiency and the bulge scalelenght as in the inverse-wind
scenario for ellipticals. We successfully reproduced the observed relation
between the BH mass and that of the host bulge, and the observed peak nuclear
bolometric luminosity. The observed metal overabundances are easily achieved,
as well as the constancy of chemical abundances with the redshift.


title:
Extrinsic Isoperimetric Analysis on Submanifolds with Curvatures Bounded
  from Below

abstract:
  We obtain upper bounds for the isoperimetric quotients of extrinsic balls of
submanifolds in ambient spaces which have a lower bound on their radial
sectional curvatures. The submanifolds are themselves only assumed to have
lower bounds on the radial part of the mean curvature vector field and on the
radial part of the intrinsic unit normals at the boundaries of the extrinsic
spheres, respectively. In the same vein we also establish lower bounds on the
mean exit time for Brownian motion in the extrinsic balls. In those cases,
where we may extend our analysis to hold all the way to infinity, we apply a
capacity comparison technique to obtain a sufficient condition for the
submanifolds to be parabolic, i.e. a condition which will guarantee that any
Brownian particle, which is free to move around in the whole submanifold, is
bound to eventually revisit any given neighborhood of its starting point with
probability 1. The results of this paper are in a rough sense dual to similar
results obtained previously by the present authors in complementary settings
where we assume that the curvatures are bounded from above.


title:
R-matrix propagation with adiabatic bases for the photoionization
  spectra of atoms in magnetic fields

abstract:
  The photoionization spectrum of an atom in a magnetic field is calculated by
combining R-matrix propagation with local adiabatic basis expansions. This
approach considerably increases the speed and the energy range over which
calculations can be performed compared to previous methods, allowing one to
obtain accurate partial and total cross sections over an extended energy range
for an arbitrary magnetic field strength. In addition, the cross sections for
all atoms of interest can be calculated simultaneously in a single calculation.
Multichannel quantum defect theory allows for a detailed analysis of the
resonance structure in the continuum. Calculated cross sections for a range of
atoms in both laboratory and astrophysical field strengths are presented.


title:
Transport properties controlled by a thermostat: An extended dissipative
  particle dynamics thermostat

abstract:
  We introduce a variation of the dissipative particle dynamics (DPD)
thermostat that allows for controlling transport properties of molecular
fluids. The standard DPD thermostat acts only on a relative velocity along the
interatomic axis. Our extension includes the damping of the perpendicular
components of the relative velocity, yet keeping the advantages of conserving
Galilei invariance and within our error bar also hydrodynamics. This leads to a
second friction parameter for tuning the transport properties of the system.
Numerical simulations of a simple Lennard-Jones fluid and liquid water
demonstrate a very sensitive behaviour of the transport properties, e.g.,
viscosity, on the strength of the new friction parameter. We envisage that the
new thermostat will be very useful for the coarse-grained and adaptive
resolution simulations of soft matter, where the diffusion constants and
viscosity of the coarse-grained models are typically too high/low,
respectively, compared to all-atom simulations.


title: Nuclear Structure Aspects of the Neutrinoless Double Beta Decay

abstract:
  In this article, we analyze some nuclear structure aspects of the
neutrinoless double beta decay nuclear matrix elements (NME), in the framework
of the Interacting Shell Model. We give results for the decays of 48Ca, 76Ge,
82Se, 124Sn, 128Te, 130Te, and 136Xe, using improved effective interactions and
valence spaces. We examine the dependence of the NME's on the effective
interaction and the valence space, and analyze the effects of the short range
correlations and the finite size of the nucleon. Finally we study the influence
of the deformation on the values of the NME's.


title:
Galactic neutrino background from cosmic ray interaction with the ISM
  content

abstract:
  We use a diffusive model for the propagation of Galactic cosmic rays to
estimate the charged pion production in interactions with protons of the
interstellar medium. Cosmic ray nuclei from proton to iron are considered and
the corresponding contribution to the neutrino secondary flux produced as a
result of spallation is also estimated.


title:
Accounting for the Unresolved X-ray Background with Sterile Neutrino
  Dark Matter

abstract:
  We consider a scenario where keV sterile neutrinos constitute all of the
currently inferred dark matter abundance, whose radiative decays could
potentially account for the flux contributions to the X-ray background
attributed to unresolved sources. Here we apply integrated flux methods to
results from the observations of the North and South Chandra deep fields in
order to deduce constraints on the sterile neutrino mass-mixing parameters.


title:
Asteroseismological constraints on the coolest GW Vir variable star (PG
  1159-type)PG 0122+200

abstract:
  We present an asteroseismological study on PG 0122+200, the coolest known
pulsating PG1159 (GW Vir) star. Our results are based on an augmented set of
the full PG1159 evolutionary models recently presented by Miller Bertolami &
Althaus (2006). We perform extensive computations of adiabatic g-mode pulsation
periods on PG1159 evolutionary models with stellar masses ranging from 0.530 to
0.741 Msun. We derive a stellar mass of 0.626 Msun from a comparison between
the observed period spacing and the computed asymptotic period spacing, and a
stellar mass of 0.567 Msun by comparing the observed period spacing with the
average of the computed period spacing. We also find, on the basis of a
period-fit procedure, an asteroseismological model representative of PG
0122+200 which is able to reproduce the observed period pattern with an average
of the period differences of 0.88 s. The model has an effective temperature of
81500 K, a stellar mass of 0.556 Msun, a surface gravity log g= 7.65, a stellar
luminosity and radius of log(L/Lsun)= 1.14 and log(R/Rsun)= -1.73,
respectively, and a He-rich envelope thickness of Menv= 0.019 Msun. We derive a
seismic distance of about 614 pc and a parallax of about 1.6 mas. The results
of the period-fit analysis carried out in this work suggest that the
asteroseismological mass of PG 0122+200 could be 6-20 % lower than thought
hitherto and in closer agreement (to within 5 %) with the spectroscopic mass.
This result suggests that a reasonable consistency between the stellar mass
values obtained from spectroscopy and asteroseismology can be expected when
detailed PG1159 evolutionary models are considered.


title:
Detrended Cross-Correlation Analysis: A New Method for Analyzing Two
  Non-stationary Time Series

abstract:
  Here we propose a method, based on detrended covariance which we call
detrended cross-correlation analysis (DXA), to investigate power-law
cross-correlations between different simultaneously-recorded time series in the
presence of non-stationarity. We illustrate the method by selected examples
from physics, physiology, and finance.


title: Theoretical progress on the V_us determination from tau decays

abstract:
  A very precise determination of V_us can be obtained from the semi-inclusive
hadronic decay width of the tau lepton into final states with strangeness. The
ratio of the Cabibbo-suppressed and Cabibbo-allowed tau decay widths directly
measures (V_us/V_ud)^2, up to very small SU(3)-breaking corrections which can
be theoretically estimated with the needed accuracy. Together with previous LEP
and CLEO data, the recent measurements by Babar and Belle of some
Cabibbo-suppressed tau decays imply V_us= 0.2165 +- 0.0026_exp +- 0.0005_th,
which is already competitive with the standard extraction from K_l3 decays. The
uncertainty is largely dominated by experimental errors and should be easily
reduced with the high statistics of the B factories, providing the most
accurate determination of this parameter. A 1% experimental precision on the
Cabibbo-suppressed tau decay width would translate into a 0.6% uncertainty on
V_us.


title: Phylogenetic networks form partial trees

abstract:
  A contemporary and fundamental problem faced by many evolutionary biologists
is how to puzzle together a collection $\mathcal P$ of partial trees
(leaf-labelled trees whose leaves are bijectively labelled by species or, more
generally, taxa, each supported by e. g. a gene) into an overall parental
structure that displays all trees in $\mathcal P$. This already difficult
problem is complicated by the fact that the trees in $\mathcal P$ regularly
support conflicting phylogenetic relationships and are not on the same but only
overlapping taxa sets. A desirable requirement on the sought after parental
structure therefore is that it can accommodate the observed conflicts.
Phylogenetic networks are a popular tool capable of doing precisely this.
However, not much is known about how to construct such networks from partial
trees, a notable exception being the $Z$-closure super-network approach and the
recently introduced $Q$-imputation approach. Here, we propose the usage of
closure rules to obtain such a network. In particular, we introduce the novel
$Y$-closure rule and show that this rule on its own or in combination with one
of Meacham's closure rules (which we call the $M$-rule) has some very desirable
theoretical properties. In addition, we use the $M$- and $Y$-rule to explore
the dependency of Rivera et al.'s ``ring of life'' on the fact that the
underpinning phylogenetic trees are all on the same data set. Our analysis
culminates in the presentation of a collection of induced subtrees from which
this ring can be reconstructed.


title: Oort groups and lifting problems

abstract:
  Let k be an algebraically closed field of positive characteristic p. We
consider which finite groups G have the property that every faithful action of
G on a connected smooth projective curve over k lifts to characteristic zero.
Oort conjectured that cyclic groups have this property. We show that if a
cyclic-by-p group G has this property, then G must be either cyclic or
dihedral, with the exception of A_4 in characteristic 2. This proves one
direction of a strong form of the Oort Conjecture.


title: Gravitating Dyons with Large Electric Charge

abstract:
  We consider non-Abelian dyons in Einstein-Yang-Mills-Higgs theory. The dyons
are spherically symmetric with unit magnetic charge. For large values of the
electric charge the dyons approach limiting solutions, related to the Penney
solutions of Einstein-Maxwell-scalar theory.


title: COSY-11 : How will we remember it ?

abstract:
  A personal selection is made of the highlights of the COSY-11 physics program
undertaken at the COoler SYnchrotron of the Forschungszentrum Juelich. This has
been particularly rich in the field of strange and non-strange meson production
in proton-proton and proton-deuteron collisions. The results are considered in
relation to experiments carried out at other facilities and with respect to
their impact on theory.


title: The Dimension of the Torelli group

abstract:
  We prove that the cohomological dimension of the Torelli group for a closed
connected orientable surface of genus g at least 2 is equal to 3g-5. This
answers a question of Mess, who proved the lower bound and settled the case of
g=2. We also find the cohomological dimension of the Johnson kernel (the
subgroup of the Torelli group generated by Dehn twists about separating curves)
to be 2g-3. For g at least 2, we prove that the top dimensional homology of the
Torelli group is infinitely generated. Finally, we give a new proof of the
theorem of Mess that gives a precise description of the Torelli group in genus
2. The main tool is a new contractible complex, called the "complex of cycles",
on which the Torelli group acts.


title: Gluino Stransverse Mass

abstract:
  We introduce a new observable, 'gluino stransverse mass', which is an
application of the Cambridge $m_{T2}$ variable to the process where gluinos are
pair produced in proton-proton collision and each gluino subsequently decays
into two quarks and one LSP, $i.e. \tilde{g}\tilde{g} \to qq\tilde\chi_1^0\
qq\tilde\chi_1^0$. We show that the gluino stransverse mass can be utilized to
measure the gluino and the lightest neutralino masses separately, and also the
(1st and 2nd generation) squark masses if lighter than the gluino mass, thereby
providing a good first look at the pattern of sparticle masses experimentally.


title: Cryptography in the Bounded-Quantum-Storage Model

abstract:
  This thesis initiates the study of cryptographic protocols in the
bounded-quantum-storage model. On the practical side, simple protocols for
Rabin Oblivious Transfer, 1-2 Oblivious Transfer and Bit Commitment are
presented. No quantum memory is required for honest players, whereas the
protocols can only be broken by an adversary controlling a large amount of
quantum memory. The protocols are efficient, non-interactive and can be
implemented with today's technology.
  On the theoretical side, new entropic uncertainty relations involving
min-entropy are established and used to prove the security of protocols
according to new strong security definitions. For instance, in the realistic
setting of Quantum Key Distribution (QKD) against quantum-memory-bounded
eavesdroppers, the uncertainty relation allows to prove the security of QKD
protocols while tolerating considerably higher error rates compared to the
standard model with unbounded adversaries.


title:
$\mathbb{Z}_{2}^{2}$-cordiality of complete and complete bipartite
  graphs

abstract:
  We prove that $K_{n}$ is $\mathbb{Z}_{2}^{2}$-cordial if and only if $1 \leq
n \leq 3$ and that $K_{m,n}$ is $\mathbb{Z}_{2}^{2}$ if and only if it is false
that $m=n=2$.


title: Equivalences on Acyclic Orientations

abstract:
  The cyclic and dihedral groups can be made to act on the set Acyc(Y) of
acyclic orientations of an undirected graph Y, and this gives rise to the
equivalence relations ~kappa and ~delta, respectively. These two actions and
their corresponding equivalence classes are closely related to combinatorial
problems arising in the context of Coxeter groups, sequential dynamical
systems, the chip-firing game, and representations of quivers.
  In this paper we construct the graphs C(Y) and D(Y) with vertex sets Acyc(Y)
and whose connected components encode the equivalence classes. The number of
connected components of these graphs are denoted kappa(Y) and delta(Y),
respectively. We characterize the structure of C(Y) and D(Y), show how delta(Y)
can be derived from kappa(Y), and give enumeration results for kappa(Y).
Moreover, we show how to associate a poset structure to each kappa-equivalence
class, and we characterize these posets. This allows us to create a bijection
from Acyc(Y)/~kappa to the union of Acyc(Y')/~kappa and Acyc(Y'')/~kappa, Y'
and Y'' denote edge deletion and edge contraction for a cycle-edge in Y,
respectively, which in turn shows that kappa(Y) may be obtained by an
evaluation of the Tutte polynomial at (1,0).


title:
On the relation between the Schmidt and Kennicutt-Schmidt star formation
  laws and its implications for numerical simulations

abstract:
  When averaged over large scales, star formation in galaxies is observed to
follow the empirical Kennicutt-Schmidt (KS) law for surface densities above a
constant threshold. While the observed law involves surface densities,
theoretical models and simulations generally work with volume density laws
(i.e. Schmidt laws). We derive analytic relations between star formation laws
expressed in terms of surface densities, volume densities, and pressures and we
show how these relations depend on parameters such as the effective equation of
state of the multiphase interstellar medium. Our analytic relations enable us
to implement observed surface density laws into simulations. Because the
parameters of our prescription for star formation are observables, we are not
free to tune them to match the observations. We test our theoretical framework
using high-resolution simulations of isolated disc galaxies that assume an
effective equation of state for the multiphase interstellar medium. We are able
to reproduce the star formation threshold and both the slope and the
normalisation of arbitrary input KS laws without tuning any parameters and with
very little scatter, even for unstable galaxies and even if we use poor
numerical resolution. Moreover, we can do so for arbitrary effective equations
of state. Our prescription therefore enables simulations of galaxies to bypass
our current inability to simulate the formation of stars. On the other hand,
the fact that we can reproduce arbitrary input thresholds and KS laws, rather
than just the particular ones picked out by nature, indicates that simulations
that lack the physics and/or resolution to simulate the multiphase interstellar
medium can only provide limited insight into the origin of the observed star
formation laws.


title: The Effective Field Theory of Inflation

abstract:
  We study the effective field theory of inflation, i.e. the most general
theory describing the fluctuations around a quasi de Sitter background, in the
case of single field models. The scalar mode can be eaten by the metric by
going to unitary gauge. In this gauge, the most general theory is built with
the lowest dimension operators invariant under spatial diffeomorphisms, like
g^{00} and K_{mu nu}, the extrinsic curvature of constant time surfaces. This
approach allows us to characterize all the possible high energy corrections to
simple slow-roll inflation, whose sizes are constrained by experiments. Also,
it describes in a common language all single field models, including those with
a small speed of sound and Ghost Inflation, and it makes explicit the
implications of having a quasi de Sitter background. The non-linear realization
of time diffeomorphisms forces correlation among different observables, like a
reduced speed of sound and an enhanced level of non-Gaussianity.


title: Brane-world inflation: slow-roll corrections to the spectral index

abstract:
  We quantify the slow-roll corrections to primordial density perturbations
arising from inflation driven by a four-dimensional scalar field with a
monomial potential in a five-dimensional non-compact bulk spacetime. Although
the difference between the classical brane-world solutions and standard
four-dimensional solutions is large at early times, the change to the amplitude
at late times of perturbations generated from quantum fluctuations is
first-order in slow-roll parameters, leading to second-order slow-roll
corrections to the spectral index. This confirms that the leading-order effects
are correctly given by previous work in the literature.


title:
On the consistency relation of the 3-point function in single field
  inflation

abstract:
  The consistency relation for the 3-point function of the CMB is a very
powerful observational signature which is believed to be true for every
inflationary model in which there is only one dynamical degree of freedom. Its
importance relies on the fact that deviations from it might be detected in next
generation experiments, allowing us to rule out all single field inflationary
models. After making more precise the already existing proof of the consistency
relation, we use a recently developed effective field theory for inflationary
perturbations to provide an alternative and very explicit proof valid at
leading non trivial order in slow roll parameters.


title: The pattern of growth in viable f(R) cosmologies

abstract:
  We study the evolution of linear perturbations in metric f(R) models of
gravity and identify a potentially observable characteristic scale-dependent
pattern in the behavior of cosmological structures. While at the background
level viable f(R) models must closely mimic LCDM, the differences in their
prediction for the growth of large scale structures can be sufficiently large
to be seen with future weak lensing surveys. While working in the Jordan frame,
we perform an analytical study of the growth of structures in the Einstein
frame, demonstrating the equivalence of the dynamics in the two frames. We also
provide a physical interpretation of the results in terms of the dynamics of an
effective dark energy fluid with a non-zero shear. We find that the growth of
structure in f(R) is enhanced, but that there are no small scale instabilities
associated with the additional attractive "fifth force". We then briefly
consider some recently proposed observational tests of modified gravity and
their utility for detecting the f(R) pattern of structure growth.


title:
Goldilocks Supersymmetry: Simultaneous Solution to the Dark Matter and
  Flavor Problems of Supersymmetry

abstract:
  Neutralino dark matter is well motivated, but also suffers from two
shortcomings: it requires gravity-mediated supersymmetry breaking, which
generically violates flavor constraints, and its thermal relic density \Omega
is typically too large. We propose a simple solution to both problems:
neutralinos freezeout with \Omega ~10-100, but then decay to ~1 GeV gravitinos,
which are simultaneously light enough to satisfy flavor constraints and heavy
enough to be all of dark matter. This scenario is naturally realized in
high-scale gauge-mediation models, ameliorates small scale structure problems,
and implies that ``cosmologically excluded'' models may, in fact, be
cosmologically preferred.


title: Narrow-band surveys for very high redshift Lyman-alpha emitters

abstract:
  Context: Many current and future surveys aim to detect the highest redshift
(z >~ 7) sources through their Lyman-alpha (Ly-alpha) emission, using the
narrow-band imaging method. However, to date the surveys have only yielded
non-detections and upper limits as no survey has reached the necessary
combination of depth and area to detect these very young star forming galaxies.
  Aims: We aim to calculate model luminosity functions and mock surveys of
Ly-alpha emitters at z >~ 7 based on a variety of approaches.
  Methods: We calculate model luminosity functions at different redshifts based
on three different approaches: a semi-analytical model based on CDM, a simple
phenomenological model, and an extrapolation of observed Schechter functions at
lower redshifts. The results of the first two models are compared with
observations made at redshifts z ~ 5.7 and z ~ 6.5, and they are then
extrapolated to higher redshift.
  Results: We present model luminosity functions for redshifts between z = 7 -
12.5 and give specific number predictions for future planned or possible
narrow-band surveys for Ly-alpha emitters. We also investigate what constraints
future observations will be able to place on the Ly-alpha luminosity function
at very high redshift.
  Conclusion: It should be possible to observe z = 7 - 10 Ly-alpha emitters
with present or near-future instruments if enough observing time is allocated.
In particular, large area surveys such as ELVIS (Emission Line galaxies with
VISTA Survey) will be useful in collecting a large sample. However, to get a
large enough sample to constrain well the z >= 10 Ly-alpha luminosity function,
instruments further in the future, such as an ELT, will be necessary.


title: Binary black hole merger: symmetry and the spin expansion

abstract:
  We regard binary black hole (BBH) merger as a map from a simple initial state
(two Kerr black holes, with dimensionless spins {\bf a} and {\bf b}) to a
simple final state (a Kerr black hole with mass m, dimensionless spin {\bf s},
and kick velocity {\bf k}). By expanding this map around {\bf a} = {\bf b} = 0
and applying symmetry constraints, we obtain a simple formalism that is
remarkably successful at explaining existing BBH simulations. It also makes
detailed predictions and suggests a more efficient way of mapping the parameter
space of binary black hole merger. Since we rely on symmetry rather than
dynamics, our expansion complements previous analytical techniques.


title:
Decoding the spectra of SDSS early-type galaxies: New indicators of age
  and recent star formation

abstract:
  (Abridged) We apply Principal Component Analysis (PCA) to a sample of
early-type galaxies from the Sloan Digital Sky Survey (SDSS) in order to infer
differences in their star formation histories. Out of the first few principal
components (PC), we study four which give information about stellar populations
and velocity dispersion. We construct two parameters (eta and zeta) as linear
combinations of PC1 and PC2. We find zeta to be most sensitive to recent
episodes of star formation, and eta to be strongly dependent on the average age
of the stellar populations. The distribution of the eta component of the
composites appear to be indistinguishable between high and low density regions,
whereas the distribution of zeta parameters have a significant skew towards
lower values for galaxies in low density regions. This result suggests that
galaxies in lower density environments are less likely to present weak episodes
of recent star formation. In contrast, a significant number of galaxies from
our high density subsample -- which includes clusters (both outer regions and
centres) and groups -- underwent small but detectable recent star formation at
high metallicity, in agreement with recent estimates targeting elliptical
galaxies in Hickson Compact Groups and in the field (Ferreras et al.).


title: Geometrically induced singular behavior of entanglement

abstract:
  We show that the geometry of the set of quantum states plays a crucial role
in the behavior of entanglement in different physical systems. More
specifically it is shown that singular points at the border of the set of
unentangled states appear as singularities in the dynamics of entanglement of
smoothly varying quantum states. We illustrate this result by implementing a
photonic parametric down conversion experiment. Moreover, this effect is
connected to recently discovered singularities in condensed matter models.


title: SN 2005ap: A Most Brilliant Explosion

abstract:
  We present unfiltered photometric observations with ROTSE-III and optical
spectroscopic follow-up with the HET and Keck of the most luminous supernova
yet identified, SN 2005ap. The spectra taken about 3 days before and 6 days
after maximum light show narrow emission lines (likely originating in the dwarf
host) and absorption lines at a redshift of z=0.2832, which puts the peak
unfiltered magnitude at -22.7 +/- 0.1 absolute. Broad P-Cygni features
corresponding to H-alpha, CIII, NIII, and OIII, are further detected with a
photospheric velocity of ~20,000 km/s. Unlike other highly luminous supernovae
such as 2006gy and 2006tf that show slow photometric evolution, the light curve
of SN 2005ap indicates a 1-3 week rise to peak followed by a relatively rapid
decay. The spectra also lack the distinct emission peaks from moderately
broadened (FWHM ~ 2,000 km/s) Balmer lines seen in SN 2006gy and SN 2006tf. We
briefly discuss the origin of the extraordinary luminosity from a strong
interaction as may be expected from a pair instability eruption or a GRB-like
engine encased in a H/He envelope.


title: Navigability of Complex Networks

abstract:
  Routing information through networks is a universal phenomenon in both
natural and manmade complex systems. When each node has full knowledge of the
global network connectivity, finding short communication paths is merely a
matter of distributed computation. However, in many real networks nodes
communicate efficiently even without such global intelligence. Here we show
that the peculiar structural characteristics of many complex networks support
efficient communication without global knowledge. We also describe a general
mechanism that explains this connection between network structure and function.
This mechanism relies on the presence of a metric space hidden behind an
observable network. Our findings suggest that real networks in nature have
underlying metric spaces that remain undiscovered. Their discovery would have
practical applications ranging from routing in the Internet and searching
social networks, to studying information flows in neural, gene regulatory
networks, or signaling pathways.


title:
Wind and boundary layers in Rayleigh-Benard convection. I: analysis and
  modeling

abstract:
  The aim of this paper is to contribute to the understanding and to model the
processes controlling the amplitude of the wind of Rayleigh-Benard convection.
We analyze results from direct simulation of an L/H = 4 aspect-ratio domain
with periodic sidewalls at Ra = 1e5; 1e6; 1e7; 1e8 and at Pr = 1 by decomposing
independent realizations into wind and fluctuations. It is shown that deep
inside the thermal boundary layer, horizontal heat-fuxes exceed the average
vertical heat-fux by a factor 3 due to the interaction between the wind and the
mean temperature field. These large horizontal heat-fluxes are responsible for
spatial temperature differences that drive the wind by creating pressure
gradients. The wall fluxes and turbulent mixing in the bulk provide damping.
Using the DNS results to parameterise the unclosed terms, a simple model
capturing the essential processes governing the wind structure is derived. The
model consists of two coupled differential equations for wind velocity and
temperature amplitude. The equations indicate that the formation of a wind
structure is inevitable due to the positive feedback resulting from the
interaction between the wind and temperature field. Furthermore, the wind
velocity is largely determined by the turbulence in the bulk rather than by the
wall-shear stress. The model reproduces the Ra dependence of wind Reynolds
number and temperature amplitude.


title: A note on the uniqueness of global static decompositions

abstract:
  We discuss when static Killing vector fields are standard, that is, leading
to a global orthogonal splitting of the spacetime. We prove that such an
orthogonal splitting is unique whenever the natural space is compact. This is
carried out by proving that many notable spacelike submanifolds must be
contained in an orthogonal slice. Possible obstructions to the global splitting
are also considered.


title:
Hydrodynamic behavior of one dimensional subdiffusive exclusion
  processes with random conductances

abstract:
  Consider a system of particles performing nearest neighbor random walks on
the lattice $\ZZ$ under hard--core interaction. The rate for a jump over a
given bond is direction--independent and the inverse of the jump rates are
i.i.d. random variables belonging to the domain of attraction of an
$\a$--stable law, $0<\a<1$. This exclusion process models conduction in
strongly disordered one-dimensional media. We prove that, when varying over the
disorder and for a suitable slowly varying function $L$, under the
super-diffusive time scaling $N^{1 + 1/\alpha}L(N)$, the density profile
evolves as the solution of the random equation $\partial_t \rho = \mf L_W
\rho$, where $\mf L_W$ is the generalized second-order differential operator
$\frac d{du} \frac d{dW}$ in which $W$ is a double sided $\a$--stable
subordinator. This result follows from a quenched hydrodynamic limit in the
case that the i.i.d. jump rates are replaced by a suitable array $\{\xi_{N,x} :
x\in\bb Z\}$ having same distribution and fulfilling an a.s. invariance
principle. We also prove a law of large numbers for a tagged particle.


title: Nonlinear growth in modified gravity theories of dark energy

abstract:
  Theoretical differences in the growth of structure offer the possibility that
we might distinguish between modified gravity theories of dark energy and
\LambdaCDM. A significant impediment to applying current and prospective large
scale galaxy and weak lensing surveys to this problem is that, while the mildly
nonlinear regime is important, there is a lack of numerical simulations of
nonlinear growth in modified gravity theories. A major question exists as to
whether existing analytical fits, created using simulations of standard
gravity, can be confidently applied. In this paper we address this, presenting
results of N-body simulations of a variety of models where gravity is altered
including the Dvali, Gabadadze and Porrati model. We consider modifications
that alter the Poisson equation and also consider the presence of anisotropic
shear stress that alters how particles respond to the gravitational potential
gradient. We establish how well analytical fits of the matter power spectrum by
Peacock and Dodds and Smith et al. are able to predict the nonlinear growth
found in the simulations from z=50 up to today, and also consider implications
for the weak lensing convergence power spectrum. We find that the analytical
fits provide good agreement with the simulations, being within 1\sigma of the
simulation results for cases with and without anisotropic stress and for
scale-dependent and independent modifications of the Poisson equation. No
strong preference for either analytical fit is found.


title:
More Rings to rule them all : Fragmentation, 4D/5D and Split-Spectral
  Flows

abstract:
  In this note we set-up an explicit 5D construction of AdS-fragmentation,
whereby a single black ring splits-up into a multi-black ring configuration.
Furthermore it is seen that these fragmented rings are equivalent to a direct
5D lift of 4D multi-center black holes. Along the way we also determine the
4D/5D transformations relevant for multi-center charges. It is seen that the
physical charges involved in black ring fragmentation are Page charges arising
due to 5D Chern-Simons terms. As an application of these methods, we reproduce
the total angular momentum of concentric black rings, originally due to
Gauntlett and Gutowski. Finally we provide a geometric interpretation of
fragmented black rings using the idea of split-spectral flows, which seeks to
study charge shifts of a given black ring due to fluxes generated in a
multi-ring background.


title: Somewhat stochastic matrices

abstract:
  The standard theorem for regular stochastic matrices is generalized to
matrices with no sign restriction on the entries. The condition that column
sums be equal to 1 is kept, but the regularity condition is replaced by a
condition on the $\ell_1$-distances between columns.


title: On the uniformity of the Iitaka fibration

abstract:
  We study pluricanonical systems on smooth projective varieties of positive
Kodaira dimension, following the approach of Hacon-McKernan, Takayama and Tsuji
succesfully used in the case of varieties of general type. We prove a
uniformity result for the Iitaka fibration of smooth projective varieties of
positive Kodaira dimension, provided that the base of the Iitaka fibration is
not uniruled, the variation of the fibration is maximal, and the generic fiber
has a good minimal model.


title: Lower bounds for the volume of hyperbolic $n$-orbifolds

abstract:
  In this paper an explicit formula for a lower bound on the volume of a
hyperbolic orbifold, dependent on dimension and the maximal order of torsion in
the orbifolds' fundamental group, is constructed.


title: Vortices in a mesoscopic superconducting circular sector

abstract:
  In the present paper we develop an algorithm to solve the time dependent
Ginzburg-Landau (TDGL) equations, by using the link variables technique, for
circular geometries. In addition, we evaluate the Helmholtz and Gibbs free
energy, the magnetization, and the number of vortices. This algorithm is
applied to a circular sector. We evaluate the superconduting-normal magnetic
field transition, the magnetization, and the superconducting density.
Furthermore, we study the nucleation of giant and multi-vortex states for that
geometry.


title: Geodesic cusp excursions and metric diophantine approximation

abstract:
  We derive several results that describe the rate at which a generic geodesic
makes excursions into and out of a cusp on a finite area hyperbolic surface and
relate them to approximation with respect to the orbit of infinity for an
associated Fuchsian group. This provides proofs of some well known theorems
from metric diophantine approximation in the context of Fuchsian groups. It
also gives new results in the classical setting.


title: The Electric Dipole Moment of the Nucleons in Holographic QCD

abstract:
  We introduce the strong CP-violation in the framework of AdS/QCD model and
calculate the electric dipole moments of nucleons as well as the CP-violating
pion-nucleon coupling. Our holographic estimate of the electric dipole moments
gives for the neutron d_n=1.08 X 10^{-16} theta (e cm), which is comparable
with previous estimates. We also predict that the electric dipole moment of the
proton should be precisely the minus of the neutron electric dipole moment,
thus leading to a new sum rule on the electric dipole moments of baryons.


title: Suppression of Meszaros' Effect in coupled DE

abstract:
  A phaenomenological DM-DE coupling could indicate their common origin.
Various constraint however exist to such coupling; here we outline that it can
suppress Meszaros' effect, yielding transfered spectra with a softer bending
above k_{hor,eq}. It could be therefore hard to reconcile these models with
both CMB and deep sample data, using a constant spectral index.


title: Evolutionary Prisoner's Dilemma game on the Newman-Watts networks

abstract:
  Maintenance of cooperation was studied for a two-strategy evolutionary
Prisoner's Dilemma game where the players are located on a one-dimensional
chain and their payoff comes from games with the nearest and next-nearest
neighbor interactions. The applied host geometry makes possible to study the
impacts of two conflicting topological features. The evolutionary rule involves
some noise affecting the strategy adoptions between the interacting players.
Using Monte Carlo simulations and the extended versions of dynamical mean-field
theory we determined the phase diagram as a function of noise level and a
payoff parameter. The peculiar feature of the diagram is changed significantly
when the connectivity structure is extended by extra links as suggested by
Newman and Watts.


title:
Microstrain and defects in polycrystalline Zn_{1-x}Mg_{x}O (0 <= x <=
  0.15) studied by X-ray diffraction, and optical and Raman spectroscopies

abstract:
  The properties of polycrystalline wurtzite Zn_{1-x}Mg_{x}O (0 <= x <= 0.15)
have been studied, by powder X-ray diffraction, including an analysis of the
X-ray line-broadening, and by luminescence, absorption, and Raman
spectroscopies. We have previously established from synchrotron X-ray
difffraction that with increasing Mg-concentration, the c-axis compresses, and
the off-center cation displacement within each tetrahedral (Zn,Mg)O_{4} unit
decreases. Here we perform a size-strain line-broadening analysis of the XRD
peaks, which reveals that the Mg-substitution reduces the coherent crystallite
size and also develops the lattice microstrain. The optical properties of the
samples have been characterized by diffuse-reflectance spectroscopy and
fluorimetry. Both the optical band gap and the band-edge emission energies
gradually increase with the Mg-concentration in Zn_{1-x}Mg_{x}O. The
Mg-substituted samples show broader band tails near the absorption edge, due to
the increase of crystal imperfections. The peak broadening of the E_{2}{high}
Raman mode, upon the Mg-substitution, is also ascribed to the phonon shortening
lifetime mechanism via crystal defects.


title: Spin-Filtering Multiferroic-Semiconductor Heterojunctions

abstract:
  We report on the structural and electronic properties of the interface
between the multiferoic oxide YMnO$_3$ and wide band-gap semiconductor GaN
studied with the Hubbard-corrected local spin density approximation (LSDA+U) to
density-functional theory (DFT). We find that the band offsets at the interface
between antiferromagnetically ordered YMnO$_3$ and GaN are different for
spin-up and spin-down states. This behavior is due to the spin splitting of the
valence band induced by the interface. The energy barrier depends on the
relative orientation of the electric polarization with respect to the
polarization direction of the GaN substrate suggesting an opportunity to create
magnetic tunnel junctions in this materials system.


title:
On the Bohr radius relationship to spin-orbit interaction, spin
  magnitude, and Thomas precession

abstract:
  The dynamics of the spin-orbit interaction in atomic hydrogen are studied in
a classical electrodynamics-like setting. A Rutherfordian atomic model is used
assuming a circular electron orbit, without the quantum principle as imposed
arbitrarily in the Bohr model, but with an ad hoc incorporation in the electron
of intrinsic spin and associated magnetic dipole moment. Analyzing the motions
of the electron spin and orbital angular momenta, it is found that in the
presence of Thomas precession, the total angular momentum averaged over the
orbit is not generally a constant of the motion. It is noted this differs from
the finding of Thomas in a similar assessment of 1927, and the reason for this
difference is provided. It is found that although the total orbit-averaged
angular momentum is not a constant of the motion, it precesses around a fixed
axis similarly to the precession of the total angular momentum vector seen in
spin-orbit coupling in quantum theory. The magnitude of the angular velocity of
the total orbit-averaged angular momentum is seen to vanish only when the spin
and orbital angular momenta are antiparallel and their mutual precession
frequencies equate. It is then found, there is a unique radius where the mutual
precession frequencies equate. Assuming the electron magnetic moment is the
Bohr magneton, and an electron g-factor of two, this radius corresponds to
where the orbital angular momentum is the reduced Planck's constant. The orbit
radius for stationary total angular momentum for the circular orbit model with
nonzero orbital angular momentum is thus the ground-state radius of the Bohr
model.


title: Thermal Giant Graviton with Non-commutative Dipole Field

abstract:
  Using the type II near-extremal 3D-branes solution we apply the T-duality and
smeared twist to construct the supergravity backgrounds which dual to the 4D
finite temperature non-commutative dipole field theories. We first consider the
zero-temperature system in which, depending on the property of dipole vectors
it may be N=2, N=1 or N=0 theory. We investigate the rotating D3-brane
configurations moving on the spactimes and show that, for the cases of N=2 and
N =1 the rotating D3-brane could be blowed up to the stable spherical
configuration which is called as giant graviton and has a less energy than the
point-like graviton. The giant graviton configuration is stable only if its
angular momentum was less than a critical value of $P_c$ which is an increasing
function of the dipole strength. For the case of non-supersymmetric theory,
however, the spherical configuration has a larger energy than the point-like
graviton. We also find that the dipole field always render the dual giant
graviton to be more stable than the point-like graviton. The relation of dual
giant graviton energy with its angular momentum, which in the AdS/CFT
correspondence being the operator anomalous dimension is obtained. We
furthermore show that the temperature does not change the property of the giant
graviton, while it will render the dual giant graviton to be unstable.


title:
A first--order irreversible thermodynamic approach to a simple energy
  converter

abstract:
  Several authors have shown that dissipative thermal cycle models based on
Finite-Time Thermodynamics exhibit loop-shaped curves of power output versus
efficiency, such as it occurs with actual dissipative thermal engines. Within
the context of First-Order Irreversible Thermodynamics (FOIT), in this work we
show that for an energy converter consisting of two coupled fluxes it is also
possible to find loop-shaped curves of both power output and the so-called
ecological function against efficiency. In a previous work Stucki [J.W. Stucki,
Eur. J. Biochem. vol. 109, 269 (1980)] used a FOIT-approach to describe the
modes of thermodynamic performance of oxidative phosphorylation involved in
ATP-synthesis within mithochondrias. In that work the author did not use the
mentioned loop-shaped curves and he proposed that oxidative phosphorylation
operates in a steady state simultaneously at minimum entropy production and
maximum efficiency, by means of a conductance matching condition between
extreme states of zero and infinite conductances respectively. In the present
work we show that all Stucki's results about the oxidative phosphorylation
energetics can be obtained without the so-called conductance matching
condition. On the other hand, we also show that the minimum entropy production
state implies both null power output and efficiency and therefore this state is
not fulfilled by the oxidative phosphorylation performance. Our results suggest
that actual efficiency values of oxidative phosphorylation performance are
better described by a mode of operation consisting in the simultaneous
maximization of the so-called ecological function and the efficiency.


title: Promote cooperation by localised small-world communication

abstract:
  The emergence and maintenance of cooperation within sizable groups of
unrelated humans offer many challenges for our understanding. We propose that
the humans' capacity of communication, such as how many and how far away the
fellows can build up mutual communications, may affect the evolution of
cooperation. We study this issue by means of the public goods game (PGG) with a
two-layered network of contacts. Players obtain payoffs from five-person public
goods interactions on a square lattice (the interaction layer). Also, they
update strategies after communicating with neighbours in learning layer, where
two players build up mutual communication with a power law probability
depending on their spatial distance. Our simulation results indicate that the
evolution of cooperation is indeed sensitive to how players choose others to
communicate with, including the amount as well as the locations. The tendency
of localised communication is proved to be a new mechanism to promote
cooperation.


title:
Analysis of the Phase Structure of Thermal QED/QCD through the HTL
  Improved Ladder Dyson-Schwinger Equation --On the Gauge Dependence of the
  Solution--

abstract:
  We solved with a numerical procedure the HTL improved ladder DS equation for
the retarded fermion self-energy function $\Sigma_R$ to study the spontaneous
generation of fermion mass in thermal QCD/QED, and studied the gauge-dependence
of the solution within a general covariant gauge where the gauge parameter
$\xi$ is any constant number.
  With the numerical solutions thus obtained, we found the followings; i) The
fermion wave function renormalization function $A(P)$ always deviates largely
from unity even at the momentum where the mass is defined, thus the
corresponding solutions explicitly contradict with the Ward-Takahashi identity.
ii) As a result, the obtained solutions strongly depend on the choice of gauge
parameters: the critical temperatures and the critical coupling constants
significantly change gauge by gauge. In all gauges we studied in the present
analysis, we could not find any solution, having a possibility to be consistent
with the Ward-Takahashi identity. Thus we are forced to investigate the
procedure to find a gauge which enables us to get a solution being consistent
with the Ward-Takahashi identity, otherwise we can not obtain any physically
sensible conclusions through the analysis of the point-vertex ladder DS
equation no matter how the gauge propagator gets improved.


title: Final Fate of Subcritical Evolutions of Boson Stars

abstract:
  We present results from a study of Type I critical phenomena in the dynamics
of general relativistic boson stars in spherical symmetry. The boson stars are
modelled with a minimally coupled, massive complex field (with no explicit
self-interaction), and are driven to the threshold of black hole formation via
their gravitational interaction with an initially imploding pulse of massless
scalar field. Using a distinct coordinate system, we reproduce previous results
[1,2], including the scaling of the lifetime of near-critical configurations,
as well as the fact that such configurations are well described as perturbed,
one-mode-unstable boson stars. In addition, we make a detailed study of the
long-time evolution of marginally subcritical configurations. Contrary to
previous claims [1,2], we find that the end state in such cases does not
involve dispersal of the bulk of the boson star field to large radial
distances, but instead can be generically described by a stable boson star
executing large amplitude oscillations. Furthermore we show that these
oscillations can be largely identified as excitations of the fundamental mode
associated with the final boson star, as computed in perturbation theory.


title: Ore extensions of principally quasi-Baer rings

abstract:
  Let $R$ be a ring and $(\sigma,\delta)$ a quasi-derivation of $R$. In this
paper, we show that if $R$ is an $(\sigma,\delta)$-skew Armendariz ring and
satisfies the condition $(\mathcal{C_{\sigma}})$, then $R$ is right p.q.-Baer
if and only if the Ore extension $R[x;\sigma,\delta]$ is right p.q.-Baer. As a
consequence we obtain a generalization of \cite{hong/2000}.


title:
Monomial bases for the centres of the group algebra and Iwahori--Hecke
  algebra of S_4

abstract:
  G. E. Murphy showed in 1983 that the centre of every symmetric group algebra
has an integral basis consisting of a specific set of monomial symmetric
polynomials in the Jucys--Murphy elements. While we have shown in earlier work
that the centre of the group algebra of S_3 has exactly three additional such
bases, we show in this paper that the centre of the group algebra of S_4 has
infinitely many bases consisting of monomial symmetric polynomials in
Jucys--Murphy elements, which we characterize completely. The proof of this
result involves establishing closed forms for coefficients of class sums in the
monomial symmetric polynomials in Jucys--Murphy elements, and solving several
resulting exponential Diophantine equations with the aid of a computer.
  Our initial motivation was in finding integral bases for the centre of the
Iwahori--Hecke algebra, and we address this question also, by finding several
integral bases of monomial symmetric polynomials in Jucys--Murphy elements for
the centre of the Iwahori--Hecke algebra of S_4.


title:
The Faint Stellar Object SDSS J1257+3419 is a Dark Matter Dominated
  System

abstract:
  A recent study has revealed SDSS J1257+3419 is either a faint and small dwarf
galaxy or a faint and widely extended globular cluster. In this Letter, the
author suggests this stellar system is a dwarf spheroidal (dSph). Adopting an
observational relation between binding energy and mass of old stellar systems,
we derive a relation between mass and size of dSphs by assuming that they are
dark matter dominated and virialized objects. Letting half-light radius
represent size of SDSS J1257+3419, we find that its mass is $\sim 7\times 10^6$
solar mass. This indicates mass-to-light ratio ($M/L$) of SDSS J1257+3419 is
about 1000 in the solar unit. This large $M/L$ is expected from a Mateo plot of
dSphs. Thus, we insist SDSS J1257+3419 is a dSph.


title:
Candidate Members and Age Estimate of the Family of Kuiper Belt Object
  2003 EL61

abstract:
  The collisional family of Kuiper belt object (KBO) 2003 EL61 opens the
possibility for many interesting new studies of processes important in the
formation and evolution of the outer solar system. As the first family in the
Kuiper belt, it can be studied using techniques developed for studying asteroid
families, although some modifications are necessary. Applying these modified
techniques allows for a dynamical study of the 2003 EL61 family. The velocity
required to change orbits is used to quantitatively identify objects near the
collision. A method for identifying family members that have potentially
diffused in resonances (like 2003 EL61) is also developed. Known family members
are among the very closest KBOs to the collision and two new likely family
members are identified: 2003 UZ117 and 1999 OY3. We also give tables of
candidate family members which require future observations to confirm
membership. We estimate that a minimum of ~1 GYr is needed for resonance
diffusion to produce the current position of 2003 EL61, implying that the
family is likely primordial. Future refinement of the age estimate is possible
once (many) more resonant objects are identified. The ancient nature of the
collision contrasts with the seemingly fresh surfaces of known family members,
suggesting that our understanding of outer solar system surfaces is incomplete.


title: Schizophrenia - a parameters' game?

abstract:
  Schizophrenia is a severe, currently incurable, relatively common mental
condition. Its symptoms are complex and widespread. It structurally and
functionally affects cortical and subcortical regions involved in cognitive,
emotional and motivational aspects of behavior. Its cause is unknown, its
diagnosis is based on statistical behavior and its treatment is elusive.
  Our paradigm addresses the complexity of schizophrenic symptoms. Building
upon recent neural vulnerability and limbic dysregulation hypotheses, it offers
a mathematical model for the evolution of the limbic system under perturbation.
Dependence on parameters and the concept of "bifurcation" could be the key to
understanding the threshold between "normality" and "disease".


title:
Penrose Model potential, compared with Coleman-Weinberg Potential for
  early universe scalar evolution

abstract:
  We present an overview of Dr. Penrose's model of a cyclic universe, minus the
big crunch which relies upon black hole collection of matter after an a long
term expansion phase from an initial big bang . We affirm that the suggested
evolution equation presented at his lecture for his model meets requirements as
to an emergent quintessence field from a vacuum state . We try to offer
suggestions as to how to investigate his controversial conformal mapping of
matter/energy via Hawkings radiation from a potentially infinite number of
black holes to a new big bang. This is his 'ripples in a pond' effect which we
find highly unusual but worth serious study and investigation.


title: The use of cosmic muons in detecting heterogeneities in large volumes

abstract:
  The muon intensity attenuation method to detect heterogeneities in large
matter volumes is analyzed. Approximate analytical expressions to estimate the
collection time and the signal to noise ratio, are proposed and validated by
Monte Carlo simulations. Important parameters, including point spread function
and coordinate reconstruction uncertainty are also estimated using Monte Carlo
simulations.


title:
Effective base point free theorem for log canonical pairs--Koll\'ar type
  theorem

abstract:
  We prove Koll\'ar's effective base point free theorem for log canonical
pairs.


title:
Dynamic nuclear polarisation in biased quantum wires with spin-orbit
  interaction

abstract:
  We propose a new method for dynamic nuclear polarisation in a quasi
one-dimensional quantum wire utilising the spin-orbit interaction, the
hyperfine interaction, and a finite source-drain potential difference. In
contrast with current methods, our scheme does not rely on external magnetic or
optical sources which makes independent control of closely placed devices much
more feasible. Using this method, a significant polarisation of a few per cent
is possible in currently available InAs wires which may be detected by
conductance measurements. This may prove useful for nuclear-magnetic-resonance
studies in nanoscale systems as well as in spin-based devices where external
magnetic and optical sources will not be suitable.


title:
Maximum likelihood estimation of a log-concave density and its
  distribution function: Basic properties and uniform consistency

abstract:
  We study nonparametric maximum likelihood estimation of a log-concave
probability density and its distribution and hazard function. Some general
properties of these estimators are derived from two characterizations. It is
shown that the rate of convergence with respect to supremum norm on a compact
interval for the density and hazard rate estimator is at least
$(\log(n)/n)^{1/3}$ and typically $(\log(n)/n)^{2/5}$, whereas the difference
between the empirical and estimated distribution function vanishes with rate
$o_{\mathrm{p}}(n^{-1/2})$ under certain regularity assumptions.


title: Leptonic Decays of the W-Boson in a Strong Electromagnetic Field

abstract:
  The probability of W-boson decay into a lepton and a neutrino in a strong
electromagnetic field is calculated. On the basis of the method for deriving
exact solutions to relativistic wave equations for charged particles, an exact
analytic expression is obtained for the partial W-decay width at an arbitrary
value of the external field strength. It is found that, in the region of
comparatively weak fields, field-induced corrections to the standard decay
width of the W-boson in a vacuum are about a few percent. In these conditions
at first we observe the decrease of the W-boson partial decay width with the
increase of the external field strength parameter. At absolute minimum the
W-width deviates from the corresponding vacuum value by a factor 0,926. Then
with further augmentation of the background field intensity the W-boson decay
width grows monotonously. In superstrong fields the partial W-width is greater
than the corresponding one in vacuum in a dozen of times.


title:
Effective base point free theorem for log canonical pairs
  II--Angehrn--Siu type theorems--

abstract:
  We prove Angehrn-Siu type effective base point freeness and point separation
for log canonical pairs.


title:
Rigorous Solution of the Spin-1 Quantum Ising Model with Single-ion
  Anisotropy

abstract:
  We solve the spin-1 quantum Ising model with single-ion anisotropy by mapping
it onto a series of segmented spin-1/2 transverse Ising chains, separated by
the $S^z =0$ states called holes. A recursion formula is derived for the
partition function to simplify the summation of hole configurations. This
allows the thermodynamic quantities of this model to be rigorously determined
in the thermodynamic limit. The low temperature behavior is governed by the
interplay between the hole excitations and the fermionic excitations within
each spin-1/2 Ising segment. The quantum critical fluctuations around the Ising
critical point of the transverse Ising model are strongly suppressed by the
hole excitations.


title:
On The Orbital Evolution of Jupiter Mass Protoplanet Embedded in A
  Self-Gravity Disk

abstract:
  We performed a series of hydro-dynamic simulations to investigate the orbital
migration of a Jovian planet embedded in a proto-stellar disk. In order to take
into account of the effect of the disk's self gravity, we developed and adopted
an \textbf{Antares} code which is based on a 2-D Godunov scheme to obtain the
exact Reimann solution for isothermal or polytropic gas, with non-reflecting
boundary conditions. Our simulations indicate that in the study of the runaway
(type III) migration, it is important to carry out a fully self consistent
treatment of the gravitational interaction between the disk and the embedded
planet. Through a series of convergence tests, we show that adequate numerical
resolution, especially within the planet's Roche lobe, critically determines
the outcome of the simulations. We consider a variety of initial conditions and
show that isolated, non eccentric protoplanet planets do not undergo type III
migration. We attribute the difference between our and previous simulations to
the contribution of a self consistent representation of the disk's self
gravity. Nevertheless, type III migration cannot be completely suppressed and
its onset requires finite amplitude perturbations such as that induced by
planet-planet interaction. We determine the radial extent of type III migration
as a function of the disk's self gravity.


title: Evolutionary intermittency and the QCD critical point

abstract:
  We investigate the dynamics of the critical isoscalar condensate, formed
during heavy-ion collisions. Our analysis is based on a simplified model where
the sigma and the pions are the only degrees of freedom. In field description,
both in physical and momentum space, we find that the freeze-out profile
presents a structure which reveals clear traces of the critical fluctuations in
the sigma-component. In particle representation, using Monte-Carlo simulations
and factorial moment analysis, we show that signatures of the initial
criticality survive at the detected pions. We propose the distribution of
suitably defined intermittency indices, incorporating dynamical effects due to
sigma-pion interaction, as the basic observable for the exploration of critical
fluctuations in heavy-ion collision experiments.


title: Counterfactuals in Quantum Mechanics

abstract:
  A review of the term "counterfactuals" in various contexts of quantum
mechanics.


title: Anomalous diffusion coefficient in disordered media from NMR relaxation

abstract:
  Application of fractional calculus to the description of anomalous diffusion
and relaxation processes in complex media provided one of the most impressive
impulses to the development of statistical physics during the last decade. In
particular the so-called fractional diffusion equation enabled one to capture
the main features of anomalous diffusion. However the price for this
achievement is rather high - the fractional diffusion coefficient becomes an
involved function of a characteristic of the media (e.g., that of the radius of
pores in the case of the porous one). Revealing this dependence from the first
principles is one of the main problems in this field of science. Another one
still remains that of extracting this dependence from the experiment. The
latter problem is tackled in the present paper. Our aim is to provide detailed
and pedagogical deriving the relationship of the fractional diffusion
coefficient with experimentally observable value from nuclear magnetic
resonance (NMR) spin-lattice relaxation data. The result obtained promotes the
NMR relaxation method to become a powerful tool in solving the problem of
experimental measuring the fractional diffusion coefficient. Also the merits
and limitations of NMR relaxation method and pulsed-field gradient (PFG) NMR
for the research of anomalous diffusion are compared and discussed.


title:
Aggregation kinetics of stiff polyelectrolytes in the presence of
  multivalent salt

abstract:
  Using molecular dynamics simulations, the kinetics of bundle formation for
stiff polyelectrolytes such as actin is studied in the solution of multivalent
salt. The dominant kinetic mode of aggregation is found to be the case of one
end of one rod meeting others at right angle due to electrostatic interactions.
The kinetic pathway to bundle formation involves a hierarchical structure of
small clusters forming initially and then feeding into larger clusters, which
is reminiscent of the flocculation dynamics of colloids. For the first few
cluster sizes, the Smoluchowski formula for the time evolution of the cluster
size gives a reasonable account for the results of our simulation without a
single fitting parameter. The description using Smoluchowski formula provides
evidence for the aggregation time scale to be controlled by diffusion, with no
appreciable energy barrier to overcome.


title:
Exactly-solvable coupled-channel potential models of atom-atom magnetic
  Feshbach resonances from supersymmetric quantum mechanics

abstract:
  Starting from a system of $N$ radial Schr\"odinger equations with a vanishing
potential and finite threshold differences between the channels, a coupled $N
\times N$ exactly-solvable potential model is obtained with the help of a
single non-conservative supersymmetric transformation. The obtained potential
matrix, which subsumes a result obtained in the literature, has a compact
analytical form, as well as its Jost matrix. It depends on $N (N+1)/2$
unconstrained parameters and on one upper-bounded parameter, the factorization
energy. A detailed study of the model is done for the $2\times 2$ case: a
geometrical analysis of the zeros of the Jost-matrix determinant shows that the
model has 0, 1 or 2 bound states, and 0 or 1 resonance; the potential
parameters are explicitly expressed in terms of its bound-state energies, of
its resonance energy and width, or of the open-channel scattering length, which
solves schematic inverse problems. As a first physical application,
exactly-solvable $2\times 2$ atom-atom interaction potentials are constructed,
for cases where a magnetic Feshbach resonance interplays with a bound or
virtual state close to threshold, which results in a large background
scattering length.


title:
Cometary Dust Trail Associated with Rosetta Mission Target:
  67P/Churyumov-Gerasimenko

abstract:
  A thin, bright dust cloud, which is associated with the Rosetta mission
target object (67P/Churyumov-Gerasimenko), was observed after the 2002
perihelion passage. The neckline structure or dust trail nature of this cloud
is controversial. In this paper, we definitively identify the dust trail and
the neckline structure using a wide-field CCD camera attached to the Kiso
1.05-m Schmidt telescope. The dust trail of 67P/Churyumov-Gerasimenko was
evident as scattered sunlight in all images taken between September 9, 2002 and
February 1, 2003, whereas the neckline structure became obvious only after late
2002.
  We compared our images with a semi-analytical dynamic model of dust grains
emitted from the nucleus. A fading of the surface brightness of the dust trail
near the nucleus enabled us to determine the typical maximum size of the
grains. Assuming spherical compact particles with a mass density of 103 kg m-3
and an albedo of 0.04, we deduced that the maximum diameter of the dust
particles was approximately 1 cm. We found that the mass-loss rate of the comet
at the perihelion was 180 +/- 50 kg s-1 on or before the 1996 apparition, while
the mass-loss rate averaged over the orbit reached 20 +/- 6 kg s-1. The result
is consistent with the studies of the dust cloud emitted in the 2002/2003
return. Therefore, we can infer that the activity of 67P/Churyumov-Gerasimenko
has showed no major change over the past dozen years or so, and the largest
grains are cyclically injected into the dust tube lying along the cometary
orbit.


title: Branson's Q-curvature in Riemannian and Spin Geometry

abstract:
  On a closed 4-dimensional Riemannian manifold, we give a lower bound for the
square of the first eigenvalue of the Yamabe operator in terms of the total
Branson's Q-curvature. As a consequence, if the manifold is spin, we relate the
first eigenvalue of the Dirac operator to the total Branson's Q-curvature. On a
closed n-dimensional manifold, $n\ge 5$, we compare the three basic conformally
covariant operators : the Branson-Paneitz, the Yamabe and the Dirac operator
(if the manifold is spin) through their first eigenvalues. Equality cases are
also characterized.


title: On the optimal contact potential of proteins

abstract:
  We analytically derive the lower bound of the total conformational energy of
a protein structure by assuming that the total conformational energy is well
approximated by the sum of sequence-dependent pairwise contact energies. The
condition for the native structure achieving the lower bound leads to the
contact energy matrix that is a scalar multiple of the native contact matrix,
i.e., the so-called Go potential. We also derive spectral relations between
contact matrix and energy matrix, and approximations related to one-dimensional
protein structures. Implications for protein structure prediction are
discussed.


title: Statistical properties of planar Voronoi tessellations

abstract:
  I present a concise review of advances realized over the past three years on
planar Poisson-Voronoi tessellations. These encompass new analytic results, a
new Monte Carlo method, and application to experimental data.


title: A-D-E Quivers and Baryonic Operators

abstract:
  We study baryonic operators of the gauge theory on multiple D3-branes at the
tip of the conifold orbifolded by a discrete subgroup Gamma of SU(2). The
string theory analysis predicts that the number and the order of the fixed
points of Gamma acting on S^2 are directly reflected in the spectrum of
baryonic operators on the corresponding quiver gauge theory constructed from
two Dynkin diagrams of the corresponding type. We confirm the prediction by
developing techniques to enumerate baryonic operators of the quiver gauge
theory which includes the gauge groups with different ranks. We also find that
the Seiberg dualities act on the baryonic operators in a non-Abelian fashion.


title: Resonances and O-curves in Hamiltonian systems

abstract:
  We investigate the problem of the existence of trajectories asymptotic to
elliptic equilibria of Hamiltonian systems in the presence of resonances.


title: Cobordism invariants of fold maps

abstract:
  This is a survey paper of author's results on cobordism groups and semigroups
of fold maps and simple fold maps. The results include: establishing a relation
between fold maps and immersions through geometrical invariants of cobordism
classes of fold maps and simple fold maps in terms of immersions with
prescribed normal bundles, detecting stable homotopy groups of spheres as
direct summands of the cobordism semigroups of fold maps, Pontryagin-Thom type
construction for -1 codimensional fold maps and estimations about the cobordism
classes of manifolds which have fold maps into stably parallelizable manifolds.
In the last section some of these results are extended and we show that our
invariants also detect stable homotopy groups of the classifying spaces $BO(k)$
as direct summands of the cobordism semigroups of fold maps.


title: Tools for NNLO QCD Calculations

abstract:
  For precision studies with QCD observables at colliders, higher order
perturbative corrections are often mandatory. For exclusive observables, like
jet cross sections or differential distributions, these corrections were until
recently only known to next-to-leading order (NLO) in perturbation theory.
Owing to many new technical developments, first next-to-next-to-leading order
(NNLO) QCD calculations are now becoming available. We review the recent
progress in this field.


title:
Macroscopic Entanglement of a Bose Einstein Condensate on a
  Superconducting Atom Chip

abstract:
  We propose and analyse a practically implementable scheme to generate
macroscopic entanglement of a Bose-Einstein condensate in a micro-magnetic trap
magnetically coupled to a superconducting loop. We treat the superconducting
loop in a quantum superposition of two different flux states coupled with the
magnetic trap to generate macroscopic entanglement. Our scheme also provides a
platform to realise interferometry of entangled atoms through the Bose-Einstein
condensate and to explore physics at the quantum-classical interface.


title: A SINFONI view of circum-nuclear star-forming rings in spiral galaxies

abstract:
  We present near-infrared (H- and K-band) SINFONI integral-field observations
of the circumnuclear star formation rings in five nearby spiral galaxies. We
made use of the relative intensities of different emission lines (i.e. [FeII],
HeI, Brg) to age date the stellar clusters present along the rings. This
qualitative, yet robust, method allows us to discriminate between two distinct
scenarios that describe how star formation progresses along the rings. Our
findings favour a model where star formation is triggered predominantly at the
intersection between the bar major axis and the inner Lindblad resonance and
then passively evolves as the clusters rotate around the ring ('Pearls on a
string' scenario), although models of stochastically distributed star formation
('Popcorn' model) cannot be completely ruled out.


title: Model of Quantum Criticality in He3 bilayers Adsorbed on graphite

abstract:
  Recent experiments on He3 bilayers adsorbed on Graphite have shown striking
quantum critical properties at the point where the first layer localizes. We
model this system with the Anderson lattice plus inter-layer Coulomb repulsion
in two dimensions. Assuming that quantum critical fluctuations come from a
vanishing of the effective hybridization, we can reproduce several features of
the system, including the apparent occurrence of two quantum critical points
(QCP), the variation of the effective mass and coherence temperature with
coverage.


title: Solution of moving-boundary problems by the spectral element method

abstract:
  This paper describes a novel numerical model aiming at solving
moving-boundary problems such as free-surface flows or fluid-structure
interaction. This model uses a moving-grid technique to solve the
Navier--Stokes equations expressed in the arbitrary Lagrangian--Eulerian
kinematics. The discretization in space is based on the spectral element
method. The coupling of the fluid equations and the moving-grid equations is
essentially done through the conditions on the moving boundaries. Two- and
three-dimensional simulations are presented: translation and rotation of a
cylinder in a fluid, and large-amplitude sloshing in a rectangular tank. The
accuracy and robustness of the present numerical model is studied and
discussed.


title:
The molecular and dusty composition of Betelgeuse's inner circumstellar
  environment

abstract:
  The study of the atmosphere of red supergiant stars in general and of
Betelgeuse (alpha Orionis) in particular is of prime importance to understand
dust formation and how mass is lost to the interstellar medium in evolved
massive stars. A molecular shell, the MOLsphere (Tsuji, 2000a), in the
atmosphere of Betelgeuse has been proposed to account for the near- and
mid-infrared spectroscopic observations of Betelgeuse. The goal is to further
test this hypothesis and to identify some of the molecules in this MOLsphere.
We report on measurements taken with the mid-infrared two-telescope beam
combiner of the VLTI, MIDI, operated between 7.5 and 13.5 $\mu$m. The data are
compared to a simple geometric model of a photosphere surrounded by a warm
absorbing and emitting shell. Physical characteristics of the shell are
derived: size, temperature and optical depth. The chemical constituents are
determined with an analysis consistent with available infrared spectra and
interferometric data. We are able to account for the measured optical depth of
the shell in the N band, the ISO-SWS spectrum and K and L band interferometric
data with a shell whose inner and outer radii are given by the above range and
with the following species: H2O, SiO and Al2O3. These results confirm the
MOLsphere model. We bring evidence for more constituents and for the presence
of species participating in the formation of dust grains in the atmosphere of
the star, i.e. well below the distance at which the dust shell is detected. We
believe these results bring key elements to the understanding of mass loss in
Betelgeuse and red supergiants in general and bring support to the dust-driven
scenario.


title:
Towards a new classification of early-type galaxies: an integral-field
  view

abstract:
  In this proceeding we make use of the two-dimensional stellar kinematics of a
representative sample of E and S0 galaxies obtained with the SAURON
integral-field spectrograph to reveal that early-type galaxies appear in two
broad flavours, depending on whether they exhibit clear large-scale rotation or
not. We measure the level of rotation via a new parameter LambdaR and use it as
a basis for a new kinematic classification that separates early-type galaxies
into slow and fast rotators. With the aid of broad-band imaging we will
reinforce this finding by comparing our kinematic results to the photometric
properties of these two classes.


title:
The kinematics of Core and Cusp galaxies: comparing HST imaging and
  integral-field observations

abstract:
  In this proceeding we look at the relationship between the photometric
nuclear properties of early-type galaxies from Hubble Space Telescope imaging
and their overall kinematics as observed with the SAURON integral-field
spectrograph. We compare the inner slope of their photometric profiles and the
Slow/Fast rotator classes, defined by the amplitude of a newly defined LambdaR
parameter, to show that slow rotators tend to be more massive systems and
display shallower inner profiles and fast rotators steper ones. It is important
to remark, however, that there is not a one-to-one relationship between the two
photometric and kinematic groups.


title:
Adiabatic Fidelity for Atom-Molecule Conversion in a Nonlinear
  Three-Level \Lambda-system

abstract:
  We investigate the dynamics of the population transfer for atom-molecule
three-level $\Lambda$-system on stimulated Raman adiabatic passage(STIRAP). We
find that the adiabatic fidelity for the coherent population trapping(CPT)
state or dark state, as the function of the adiabatic parameter, approaches to
unit in a power law. The power exponent however is much less than the
prediction of linear adiabatic theorem. We further discuss how to achieve
higher adiabatic fidelity for the dark state through optimizing the external
parameters of STIRAP. Our discussions are helpful to gain higher atom-molecule
conversion yield in practical experiments.


title:
Periodically rippled graphene: growth and spatially resolved electronic
  structure

abstract:
  We studied the growth of an epitaxial graphene monolayer on Ru(0001). The
graphene monolayer covers uniformly the Ru substrate over lateral distances
larger than several microns reproducing the structural defects of the Ru
substrate. The graphene is rippled with a periodicity dictated by the
difference in lattice parameter between C and Ru. The theoretical model predict
inhomogeneities in the electronic structure. This is confirmed by measurements
in real space by means of scanning tunnelling spectroscopy. We observe electron
pockets at the higher parts of the ripples.


title: A Problem in Categories

abstract:
  The problem is posed to find out for arbitrary nonvoid sets $X$ which are all
the mappings $T : X \longrightarrow X$ that can be defined and each separately
identified through means of categories alone. As argued, this problem may have
a certain foundational relevance.


title:
Non-perturbative renormalization-group approach to zero-temperature Bose
  systems

abstract:
  We use a non-perturbative renormalization-group technique to study
interacting bosons at zero temperature. Our approach reveals the instability of
the Bogoliubov fixed point when $d\leq 3$ and yields the exact infrared
behavior in all dimensions $d>1$ within a rather simple theoretical framework.
It also enables to compute the low-energy properties in terms of the parameters
of a microscopic model. In one-dimension and for not too strong interactions,
it yields a good picture of the Luttinger-liquid behavior of the superfluid
phase.


title:
Electromagnetic cloaking by layered structure of homogeneous isotropic
  materials

abstract:
  Electromagnetic invisibility cloak requires material with anisotropic
distribution of the constitutive parameters deduced from a geometrical
transformation as first proposed by Pendry et al. [Science 312, 1780 (2006)].
In this paper, we proposed a useful method to realize the required
radius-dependent, anisotropic material parameters and to construct an
electromagnetic cloak through concentric layered structure of thin, alternating
layers of homogeneous isotropic materials. With proper design of the
permittivity or the thickness ratio of the alternating layers, we demonstrated
the low-reflection and power-flow bending properties of the proposed cloaking
structure through rigorous analysis of the scattered electromagnetic fields.
The proposed cloaking structure does not require anisotropy or inhomogeneity of
the material constitutive parameters usually realized by metamaterials with
subwavelength structured inclusions, therefore may lead to a practical path to
an experimental demonstration of electromagnetic cloaking, especially in the
optical range.


title: On the Hamiltonian whose spectrum coincides with the set of primes

abstract:
  The problem of construction of a simple one - dimensional Hamiltonian whose
spectrum coincides with the set of primes is considered. We note that
quasiclassically a Hamiltonian whose spectrum has the same counting function as
that of the primes in the leading order (i. e. integral logarithm) can be
constructed with the function V(x) whose inverse is asymptotically given by
x=li(V^(1/2)). Hamiltonians, whose spectra coincide with the first 1 - 1000
primes are constructed numerically and their fractal structure is revealed. The
possibility of using such a "prime-generating" Hamiltonian for investigation of
certain number-theoretical problems is discussed.


title:
Polarized Single Top Quark Production in e\gamma Collision and Anomalous
  Wtb Couplings

abstract:
  We investigate the potential of $e\gamma$ collisions to probe anomalous $Wtb$
couplings via the polarized single top quark production process $e^{+} \gamma
\to t \bar{b} \bar{\nu_{e}}$. We find 95% confidence level limits on the
anomalous coupling parameters $F_{2L}$ and $F_{2R}$ with an integrated
luminosity of $500 fb^{-1}$ and $\sqrt{s}=0.5, 1$ and 1.5 TeV energies. The
effects of top quark spin polarization on the anomalous $Wtb$ couplings are
discussed. It is shown that polarization leads to a considerable improvement in
the sensitivity limits.


title:
Control of the mean number of false discoveries, Bonferroni and
  stability of multiple testing

abstract:
  The Bonferroni multiple testing procedure is commonly perceived as being
overly conservative in large-scale simultaneous testing situations such as
those that arise in microarray data analysis. The objective of the present
study is to show that this popular belief is due to overly stringent
requirements that are typically imposed on the procedure rather than to its
conservative nature. To get over its notorious conservatism, we advocate using
the Bonferroni selection rule as a procedure that controls the per family error
rate (PFER). The present paper reports the first study of stability properties
of the Bonferroni and Benjamini--Hochberg procedures. The Bonferroni procedure
shows a superior stability in terms of the variance of both the number of true
discoveries and the total number of discoveries, a property that is especially
important in the presence of correlations between individual $p$-values. Its
stability and the ability to provide strong control of the PFER make the
Bonferroni procedure an attractive choice in microarray studies.


title:
Relationship between clustering and algorithmic phase transitions in the
  random k-XORSAT model and its NP-complete extensions

abstract:
  We study the performances of stochastic heuristic search algorithms on
Uniquely Extendible Constraint Satisfaction Problems with random inputs. We
show that, for any heuristic preserving the Poissonian nature of the underlying
instance, the (heuristic-dependent) largest ratio $\alpha_a$ of constraints per
variables for which a search algorithm is likely to find solutions is smaller
than the critical ratio $\alpha_d$ above which solutions are clustered and
highly correlated. In addition we show that the clustering ratio can be reached
when the number k of variables per constraints goes to infinity by the
so-called Generalized Unit Clause heuristic.


title:
Vortex spectrum in superfluid turbulence: interpretation of a recent
  experiment

abstract:
  We discuss a recent experiment in which the spectrum of the vortex line
density fluctuations has been measured in superfluid turbulence. The observed
frequency dependence of the spectrum, $f^{-5/3}$, disagrees with classical
vorticity spectra if, following the literature, the vortex line density is
interpreted as a measure of the vorticity or enstrophy. We argue that the
disagrement is solved if the vortex line density field is decomposed into a
polarised field (which carries most of the energy) and an isotropic field
(which is responsible for the spectrum).


title: Sea-quark effects in the pion charge form factor

abstract:
  It is shown that the data on the pion charge form factor admit the
possibility for a substantial sea-quark components in the pion wave function.
If the charge form factor is calculated with instant form kinematics in a
constituent quark model that is extended to include explicit $(q\bar q)^2$
components in the pion wave function, that component will give the dominant
contribution to the calculated $\pi^+$ charge form factor at large values of
momentum transfer. The present experimental values $Q^2$ can be described well
with $(q\bar q)^2$ component admixtures of up to 50%. The sensitivity of the
calculated $\pi^+$ charge form factor to whether one of the quarks or one of
the antiquarks is taken to be in the P-state is small.


title: An Integrated Simulation System for Human Factors Study

abstract:
  It has been reported that virtual reality can be a useful tool for ergonomics
study. The proposed integrated simulation system aims at measuring operator's
performance in an interactive way for 2D control panel design. By incorporating
some sophisticated virtual reality hardware/software, the system allows natural
human-system and/or human-human interaction in a simulated virtual environment;
enables dynamic objective measurement of human performance; and evaluates the
quality of the system design in human factors perspective based on the
measurement. It can also be for operation training for some 2D control panels.


title:
The contact conductance of a one-dimensional wire partly embedded in a
  superconductor

abstract:
  The conductance through a semi-infinite one-dimensional wire, partly embedded
in a superconducting bulk electrode, is studied. When the electron-electron
interactions within the wire are strongly repulsive, the wire effectively
decouples from the superconductor. If they are moderately or weakly repulsive,
the proximity of the superconductor induces superconducting order in the
segment of the wire embedded in it. In this case it is shown that the
conductance exhibits a crossover from conductive to insulating behavior as the
temperature is lowered down. The characteristic crossover temperature of this
transition has a stretched exponential dependence on the length of the part of
the wire embedded in the superconductor. The amount of this stretch is
determined by the nature of the electron interactions within the wire.


title:
A coupled approximate deconvolution and dynamic mixed scale model for
  large-eddy simulation

abstract:
  Large-eddy simulations of incompressible Newtonian fluid flows with
approximate deconvolution models based on the van Cittert method are reported.
The Legendre spectral element method is used for the spatial discretization to
solve the filtered Navier--Stokes equations. A novel variant of approximate
deconvolution models blended with a mixed scale model using a dynamic
evaluation of the subgrid-viscosity constant is proposed. This model is
validated by comparing the large-eddy simulation with the direct numerical
simulation of the flow in a lid-driven cubical cavity, performed at a Reynolds
number of 12'000. Subgrid modeling in the case of a flow with coexisting
laminar, transitional and turbulent zones such as the lid-driven cubical cavity
flow represents a challenging problem. Moreover, the coupling with the spectral
element method having very low numerical dissipation and dispersion builds a
well suited framework to analyze the efficiency of a subgrid model. First- and
second-order statistics obtained using this new model are showing very good
agreement with the direct numerical simulation. Filtering operations rely on an
invertible filter applied in a modal basis and preserving the C0-continuity
across elements. No clipping on dynamic parameters was needed to preserve
numerical stability.


title:
A long exact sequence in cohomology for deleted and restricted subspaces
  arrangements

abstract:
  The notions of deleted and restricted arrangements have been useful in the
study of arrangements of hyperplanes. If A is an arrangement of hyperplanes, x
in A and A', A'' the deleted and restricted arrangements, there is a formula
connecting the Poincare polynomials of the complement spaces M(A), M(A') and
M(A'').
  In this paper, we consider the extension of this formula to arbitrary
subspaces arrangements. The main result is the existence of a long exact
sequence connecting the rational cohomology of M(A), M(A') and M(A''). Using
this sequence, we obtain new results connecting the Betti numbers and Poincare
polynomials of deleted and restricted arrangements.


title: Accelerating Universe from an Evolving Lambda in Higher Dimension

abstract:
  We find exact solutions in five dimensional inhomogeneous matter dominated
model with a varying cosmological constant. Adjusting arbitrary constants of
integration one can also achieve acceleration in our model. Aside from an
initial singularity our spacetime is regular everywhere including the centre of
the inhomogeneous distribution. We also study the analogous homogeneous
universe in (4+d) dimensions. Here an initially decelerating model is found to
give late acceleration in conformity with the current observational demands. We
also find that both anisotropy and number of dimensions have a role to play in
determining the time of flip, in fact the flip is delayed in multidimensional
models. Some astrophysical parameters like the age, luminosity distance etc are
also calculated and the influence of extra dimensions is briefly discussed.
Interestingly our model yields a larger age of the universe compared to many
other quintessential models.