title:
Planetary Nebulae in Face-On Spiral Galaxies. I. Planetary Nebula
  Photometry and Distances

abstract:
  As the first step to determine disk mass-to-light ratios for normal spiral
galaxies, we present the results of an imaging survey for planetary nebulae
(PNe) in six nearby, face-on systems: IC 342, M74 (NGC 628), M83 (NGC 5236),
M94 (NGC 4736), NGC 5068, and NGC 6946. Using Blanco/Mosaic II and WIYN/OPTIC,
we identify 165, 153, 241, 150, 19, and 71 PN candidates, respectively, and use
the Planetary Nebula Luminosity Function (PNLF) to obtain distances. For M74
and NGC 5068, our distances of 8.6 +/- 0.3 Mpc and 5.4 +0.2/-0.4 Mpc are the
first reliable estimates to these objects; for IC 342 (3.5 +/- 0.3 Mpc), M83
(4.8 +/- 0.1 Mpc), M94 (4.4 +0.1/-0.2 Mpc), and NGC 6946 (6.1 +/- 0.6 Mpc) our
values agree well with those in the literature. In the larger systems, we find
no evidence for any systematic change in the PNLF with galactic position,
though we do see minor field-to-field variations in the luminosity function. In
most cases, these changes do not affect the measurement of distance, but in one
case the fluctuations result in a ~0.2 mag shift in the location of the PNLF
cutoff. We discuss the possible causes of these small-scale changes, including
internal extinction in the host galaxies and age/metallicity changes in the
underlying stellar population.


title:
The Mass Distribution and Lifetime of Prestellar Cores in Perseus,
  Serpens, and Ophiuchus

abstract:
  We present an unbiased census of starless cores in Perseus, Serpens, and
Ophiuchus, assembled by comparing large-scale Bolocam 1.1 mm continuum emission
maps with Spitzer c2d surveys. We use the c2d catalogs to separate 108 starless
from 92 protostellar cores in the 1.1 mm core samples from Enoch et al. (2006),
Young et al. (2006), and Enoch et al. (2007). A comparison of these populations
reveals the initial conditions of the starless cores. Starless cores in Perseus
have similar masses but larger sizes and lower densities on average than
protostellar cores, with sizes that suggest density profiles substantially
flatter than r^-2. By contrast, starless cores in Serpens are compact and have
lower masses than protostellar cores; future star formation will likely result
in lower mass objects than the currently forming protostars. Comparison to
dynamical masses estimated from the NH_3 survey of Perseus cores by Rosolowsky
et al. (2007) suggests that most of the starless cores are likely to be
gravitationally bound, and thus prestellar. The combined prestellar core mass
distribution includes 108 cores and has a slope of -2.3+/-0.4 for M>0.8 Msun.
This slope is consistent with recent measurements of the stellar initial mass
function, providing further evidence that stellar masses are directly linked to
the core formation process. We place a lower limit on the core-to-star
efficiency of 25%. There are approximately equal numbers of prestellar and
protostellar cores in each cloud, thus the dense prestellar core lifetime must
be similar to the lifetime of embedded protostars, or 4.5x10^5 years, with a
total uncertainty of a factor of two. Such a short lifetime suggests a dynamic,
rather than quasi-static, core evolution scenario, at least at the relatively
high mean densities (n>2x10^4 cm^-3) to which we are sensitive.


title: Some Directions beyond Traditional Quantum Secret Sharing

abstract:
  We investigate two directions beyond the traditional quantum secret sharing
(QSS). First, a restriction on QSS that comes from the no-cloning theorem is
that any pair of authorized sets in an access structure should overlap. From
the viewpoint of application, this places an unnatural constraint on secret
sharing. We present a generalization, called assisted QSS (AQSS), where access
structures without pairwise overlap of authorized sets is permissible, provided
some shares are withheld by the share dealer. We show that no more than
$\lambda-1$ withheld shares are required, where $\lambda$ is the minimum number
of {\em partially linked classes} among the authorized sets for the QSS. Our
result means that such applications of QSS need not be thwarted by the
no-cloning theorem. Secondly, we point out a way of combining the features of
QSS and quantum key distribution (QKD) for applications where a classical
information is shared by quantum means. We observe that in such case, it is
often possible to reduce the security proof of QSS to that of QKD.


title: Eigenvalues of sums of pseudo-Hermitian matrices

abstract:
  We study analogues of classical inequalities for the eigenvalues of sums of
pseudo-Hermitian matrices.


title:
Direction-dependent Jeans instability in an anisotropic Bianchi type I
  space-time

abstract:
  We derive the metric for a Bianchi type I space-time with energy density that
is dominated by that of a perfect fluid with equation of state $p=w\rho$ and
whose anisotropy is seeded by a fixed norm spacelike vector field. We solve for
the evolution of perturbations about this space-time. In particular, the Jeans
instability in an expanding flat Friedmann-Robertson-Walker universe is
modified by the presence of the vector field so that energy density
perturbations develop direction-dependent growth. We also briefly consider
observational limits on the vector field vacuum expectation value, $m$. We find
that, if $m$ is constant during recombination and thereafter, $m \lesssim
10^{14} GeV$.


title: Electromagnetic Circuits

abstract:
  The electromagnetic analog of an elastic spring-mass network is constructed.
These electromagnetic circuits offer the promise of manipulating
electromagnetic fields in new ways, and linear electrical circuits correspond
to a subclass of them. They consist of thin triangular magnetic components
joined at the edges by cylindrical dielectric components. (There are also dual
electromagnetic circuits consisting of thin triangular dielectric components
joined at the edges by cylindrical magnetic components.) Some of the edges can
be terminal edges to which electric fields are applied. The response is
measured in terms of the real or virtual free currents that are associated with
the terminal edges. The relation between the terminal electric fields and the
terminal free currents is governed by a symmetric complex matrix $\BW$. In the
case where all the terminal edges are disjoint, and the frequency is fixed, a
complete characterization is obtained of all possible response matrices $\BW$
both in the lossless and lossy cases. This is done by introducing a subclass of
electromagnetic circuits, called electromagnetic ladder networks. It is shown
that an electromagnetic ladder network, structured as a cubic network, can have
a macroscopic electromagnetic continuum response which is non-Maxwellian, and
novel.


title: Dynamical chiral symmetry breaking in strangelets at finite temperature

abstract:
  A model for strangelets at finite temperature is built, in which the quark
masses are dynamically generated. The dynamical chiral symmetry breaking inside
strangelets at finite temperature is investigated. It is found that the chiral
symmetry is going to break spontaneously inside the strangelets at some finite
temperature, and then the masses of strange quarks inside the strangelets
increase as the temperature rises. The phenomenon that strange quark mass
increases with temperature after the chiral symmetry breaks spontaneously is
illustrated by some typical numerical examples.


title: Periodic giant-persistent current in sharp pulses on a ring

abstract:
  We show here a mesoscopic device based on a narrow ring containing an
electron. In the device, an amount of energy is stored in advance. Similar to
the pendulum, an exact periodic motion of the electron is thereby initiated
afterward. The motion appears as a series of sharp pulses, and is in nature
different from the well known Aharonov-Bohm (A-B) oscillation. In particular,
the pulses of current can be tuned to be very strong (say, more than two orders
stronger than the usual A-B current). Related theory and numerical results are
presented.


title: Elliptic Dedekind Domains Revisited

abstract:
  We give an affirmative answer to a 1976 question of M. Rosen: every abelian
group is isomorphic to the class group of an elliptic Dedekind domain R. We can
choose R to be the integral closure of a PID in a separable quadratic field
extension. In particular, this yields new and -- we feel -- simpler proofs of
theorems of L. Claborn and C.R. Leedham-Green.


title:
Electrically driven single electron spin resonance in a slanting Zeeman
  field

abstract:
  The rapidly rising fields of spintronics and quantum information science have
led to a strong interest in developing the ability to coherently manipulate
electron spins. Electron spin resonance (ESR) is a powerful technique to
manipulate spins that is commonly achieved by applying an oscillating magnetic
field. However, the technique has proven very challenging when addressing
individual spins. In contrast, by mixing the spin and charge degrees of freedom
in a controlled way through engineered non-uniform magnetic fields, electron
spin can be manipulated electrically without the need of high-frequency
magnetic fields. Here we realize electrically-driven addressable spin rotations
on two individual electrons by integrating a micron-size ferromagnet to a
double quantum dot device. We find that the electrical control and spin
selectivity is enabled by the micro-magnet's stray magnetic field which can be
tailored to multi-dots architecture. Our results demonstrate the feasibility of
manipulating electron spins electrically in a scalable way.


title:
Galactic clusters with associated Cepheid variables. VII. Berkeley 58
  and CG Cassiopeiae

abstract:
  Photoelectric, photographic, and CCD UBV photometry, spectroscopic
observations, and star counts are presented for the open cluster Berkeley 58 to
examine a possible association with the 4.37d Cepheid CG Cas. The cluster is
difficult to separate from the early-type stars belonging to the Perseus spiral
arm, in which it is located, but has reasonably well-defined parameters: an
evolutionary age of ~10^8 years, a mean reddening of E(B-V)_(B0)=0.70+-0.03
s.e., and a distance of 3.03+-0.17 kpc (V_0-M_V=12.40+-0.12 s.d.). CG Cas is a
likely cluster coronal member on the basis of radial velocity, and its period
increase of +0.170+-0.014 s yr^(-1) and large light amplitude describe a
Cepheid in the third crossing of the instability strip lying slightly blueward
of strip centre. Its inferred reddening and luminosity are E(B-V)=0.64+-0.02
s.e. and <M_V> =-3.06+-0.12. A possible K supergiant may also be a cluster
member.


title: On the Law of Directionality of Genome Evolution

abstract:
  The problem of the directionality of genome evolution is studied from the
information-theoretic view. We propose that the function-coding information
quantity of a genome always grows in the course of evolution through sequence
duplication, expansion of code, and gene transfer between genomes. The
function-coding information quantity of a genome consists of two parts,
p-coding information quantity which encodes functional protein and n-coding
information quantity which encodes other functional elements except amino acid
sequence. The relation of the proposed law to the thermodynamic laws is
indicated. The evolutionary trends of DNA sequences revealed by bioinformatics
are investigated which afford further evidences on the evolutionary law. It is
argued that the directionality of genome evolution comes from species
competition adaptive to environment. An expression on the evolutionary rate of
genome is proposed that the rate is a function of Darwin temperature
(describing species competition) and fitness slope (describing adaptive
landscape). Finally, the problem of directly experimental test on the
evolutionary directionality is discussed briefly.


title: Construction of topological defect networks with complex scalar fields

abstract:
  This work deals with the construction of networks of topological defects in
models described by a single complex scalar field. We take advantage of the
deformation procedure recently used to describe kinklike defects in order to
build networks of topological defects, which appear from complex field models
with potentials that engender a finite number of isolated minima, both in the
case where the minima present discrete symmetry, and in the non symmetric case.
We show that the presence of symmetry guide us to the construction of regular
networks, while the non symmetric case gives rise to irregular networks which
spread throughout the complex field space. We also discuss bifurcation, a
phenomenon that appear in the non symmetric case, but is washed out by the
deformation procedure used in the present work.


title: N=8 superconformal gauge theories and M2 branes

abstract:
  Based on recent developments, in this letter we find 2+1 dimensional gauge
theories with scale invariance and N=8 supersymmetry. The gauge theories are
defined by a Lagrangian and are based on an infinite set of 3-algebras,
constructed as an extension of ordinary Lie algebras. Recent no-go theorems on
the existence of 3-algebras are circumvented by relaxing the assumption that
the invariant metric is positive definite. The gauge group is non compact, and
its maximally compact subgroup can be chosen to be any ordinary Lie group,
under which the matter fields are adjoints or singlets. The theories are parity
invariant and do not admit any tunable coupling constant. In the case of SU(N)
the moduli space of vacua contains a branch of the form (R^8)^N/S_N. These
properties are expected for the field theory living on a stack of M2 branes.


title: Network Coding for Speedup in Switches

abstract:
  We present a graph theoretic upper bound on speedup needed to achieve 100%
throughput in a multicast switch using network coding. By bounding speedup, we
show the equivalence between network coding and speedup in multicast switches -
i.e. network coding, which is usually implemented using software, can in many
cases substitute speedup, which is often achieved by adding extra switch
fabrics. This bound is based on an approach to network coding problems called
the "enhanced conflict graph". We show that the "imperfection ratio" of the
enhanced conflict graph gives an upper bound on speedup. In particular, we
apply this result to K-by-N switches with traffic patterns consisting of
unicasts and broadcasts only to obtain an upper bound of min{(2K-1)/K,
2N/(N+1)}.


title:
Optical and IR observations of SN 2002dj: some possible common
  properties of fast expanding SNe Ia

abstract:
  As part of the European Supernova Collaboration we obtained extensive
photometry and spectroscopy of the type Ia SN 2002dj covering epochs from 11
days before to nearly two years after maximum. Detailed optical and
near-infrared observations show that this object belongs to the class of the
high-velocity gradient events as indicated by Si, S and Ca lines. The light
curve shape and velocity evolution of SN 2002dj appear to be nearly identical
to SN 2002bo. The only significant difference is observed in the optical to
near-IR colours and a reduced spectral emission beyond 6500 A. For
high-velocity gradient Type Ia supernovae, we tentatively identify a faster
rise to maximum, a more pronounced inflection in the V and R light curves after
maximum and a brighter, slower declining late-time B light curve as common
photometric properties of this class of objects. They also seem to be
characterized by a different colour and colour evolution with respect to
``normal'' SNe Ia. The usual light curve shape parameters do not distinguish
these events. Stronger, more blueshifted absorption features of
intermediate-mass elements and lower temperatures are the most prominent
spectroscopic features of Type Ia supernovae displaying high velocity
gradients. It appears that these events burn more intermediate-mass elements in
the outer layers. Possible connections to the metallicity of the progenitor
star are explored.


title: Relative entropy of entanglement for certain multipartite mixed states

abstract:
  We prove conjectures on the relative entropy of entanglement (REE) for two
families of multipartite qubit states. Thus, analytic expressions of REE for
these families of states can be given. The first family of states are composed
of mixture of some permutation-invariant multi-qubit states. The results
generalized to multi-qudit states are also shown to hold. The second family of
states contain D\"ur's bound entangled states. Along the way, we have discussed
the relation of REE to two other measures: robustness of entanglement and
geometric measure of entanglement, slightly extending previous results.


title: CANGAROO-III Search for Gamma Rays from Kepler's Supernova Remnant

abstract:
  Kepler's supernova, discovered in October 1604, produced a remnant that has
been well studied observationally in the radio, infrared, optical, and X-ray
bands, and theoretically. Some models have predicted a TeV gamma-ray flux that
is detectable with current Imaging Cherenkov Atmospheric Telescopes. We report
on observations carried out in 2005 April with the CANGAROO-III telescope. No
statistically significant excess was observed, and limitations on the allowed
parameter range in the model are discussed.


title:
Exact and non-stiff sampling of highly oscillatory systems: an implicit
  mass-matrix penalization approach

abstract:
  We propose and analyze an implicit mass-matrix penalization (IMMP) technique
which enables efficient and exact sampling of the (Boltzmann/Gibbs) canonical
distribution associated to Hamiltonian systems with fast degrees of freedom
(fDOFs). The penalty parameters enable arbitrary tuning of the timescale for
the selected fDOFs, and the method is interpreted as an interpolation between
the exact Hamiltonian dynamics and the dynamics with infinitely slow fDOFs
(equivalent to geometrically corrected rigid constraints). This property
translates in the associated numerical methods into a tunable trade-off between
stability and dynamical modification. The penalization is based on an extended
Hamiltonian with artificial constraints associated with each fDOF. By
construction, the resulting dynamics is statistically exact with respect to the
canonical distribution in position variables.
  The algorithms can be easily implemented with standard geometric integrators
with algebraic constraints given by the expected fDOFs, and has no additional
complexity in terms of enforcing the constraint and force evaluations. The
method is demonstrated on a high dimensional system with non-convex
interactions. Prescribing the macroscopic dynamical timescale, it is shown that
the IMMP method increases the time-step stability region with a gain that grows
linearly with the size of the system. The latter property, as well as
consistency of the macroscopic dynamics of the IMMP method is proved rigorously
for linear interactions. Finally, when a large stiffness parameter is
introduced, the IMMP method can be tuned to be asymptotically stable,
converging towards the heuristically expected Markovian effective dynamics on
the slow manifold.


title: Heavy Quark Production from Jet Conversions in a Quark-Gluon Plasma

abstract:
  Recently, it has been demonstrated that the chemical composition of jets in
heavy ion collisions is significantly altered compared to jets in the vacuum.
This signal can be used to probe the medium formed in nuclear collisions. In
this study we investigate the possibility that fast light quarks and gluons can
convert to heavy quarks when passing through a quark gluon plasma. We study the
rate of light to heavy jet conversions in a consistent Fokker-Planck framework
and investigate their impact on the production of high-$p_T$ charm and bottom
quarks at RHIC and LHC.


title:
The Rapidly Flaring Afterglow of the Very Bright and Energetic GRB
  070125

abstract:
  We report on multi-wavelength observations, ranging from the X-ray to radio
wave bands, of the IPN-localized gamma-ray burst GRB 070125. Spectroscopic
observations reveal the presence of absorption lines due to O I, Si II, and C
IV, implying a likely redshift of z = 1.547. The well-sampled light curves, in
particular from 0.5 to 4 days after the burst, suggest a jet break at 3.7 days,
corresponding to a jet opening angle of ~7.0 degrees, and implying an intrinsic
GRB energy in the 1 - 10,000 keV band of around E = (6.3 - 6.9)x 10^(51) erg
(based on the fluences measured by the gamma-ray detectors of the IPN network).
GRB 070125 is among the brightest afterglows observed to date. The spectral
energy distribution implies a host extinction of Av < 0.9 mag. Two
rebrightening episodes are observed, one with excellent time coverage, showing
an increase in flux of 56% in ~8000 seconds. The evolution of the afterglow
light curve is achromatic at all times. Late-time observations of the afterglow
do not show evidence for emission from an underlying host galaxy or supernova.
Any host galaxy would be subluminous, consistent with current GRB host-galaxy
samples. Evidence for strong Mg II absorption features is not found, which is
perhaps surprising in view of the relatively high redshift of this burst and
the high likelihood for such features along GRB-selected lines of sight.


title: Horizons vs. singularities in spherically symmetric space-times

abstract:
  We discuss different kinds of Killing horizons possible in static,
spherically symmetric configurations and recently classified as "usual",
"naked" and "truly naked" ones depending on the near-horizon behavior of
transverse tidal forces acting on an extended body. We obtain necessary
conditions for the metric to be extensible beyond a horizon in terms of an
arbitrary radial coordinate and show that all truly naked horizons, as well as
many of those previously characterized as naked and even usual ones, do not
admit an extension and therefore must be considered as singularities. Some
examples are given, showing which kinds of matter are able to create specific
space-times with different kinds of horizons, including truly naked ones. Among
them are fluids with negative pressure and scalar fields with a particular
behavior of the potential. We also discuss horizons and singularities in
Kantowski-Sachs spherically symmetric cosmologies and present horizon
regularity conditions in terms of an arbitrary time coordinate and proper
(synchronous) time. It turns out that horizons of orders 2 and higher occur in
infinite proper times in the past or future, but one-way communication with
regions beyond such horizons is still possible.


title: Adaptive Affinity Propagation Clustering

abstract:
  Affinity propagation clustering (AP) has two limitations: it is hard to know
what value of parameter 'preference' can yield an optimal clustering solution,
and oscillations cannot be eliminated automatically if occur. The adaptive AP
method is proposed to overcome these limitations, including adaptive scanning
of preferences to search space of the number of clusters for finding the
optimal clustering solution, adaptive adjustment of damping factors to
eliminate oscillations, and adaptive escaping from oscillations when the
damping adjustment technique fails. Experimental results on simulated and real
data sets show that the adaptive AP is effective and can outperform AP in
quality of clustering results.


title:
Minimum Dissipative Relaxed States Applied to Laboratory and Space
  Plasmas

abstract:
  The usual theory of plasma relaxation, based on the selective decay of
magnetic energy over the (global) magnetic helicity, predicts a force-free
state for a plasma. Such a force-free state is inadequate to describe most
realistic plasma systems occurring in laboratory and space plasmas as it
produces a zero pressure gradient and cannot couple magnetic fields with flow.
A different theory of relaxation has been proposed by many authors, based on a
well-known principle of irreversible thermodynamics, the principle of minimum
entropy production rate which is equivalent to the minimum dissipation rate
(MDR) of energy. We demonstrate the applicability of minimum dissipative
relaxed states to various self-organized systems of magnetically confined
plasma in the laboratory and in the astrophysical context. Such relaxed states
are shown to produce a number of basic characteristics of laboratory plasma
confinement systems and solar arcade structure.


title:
Electron Shock Surfing Acceleration in Multidimensions: Two-dimensional
  Particle-In-Cell Simulation of Collisionless Perpendicular Shock

abstract:
  Electron acceleration mechanism at high Mach number collisionless shocks
propagating in a weakly magnetized medium is investigated by a self-consistent
two-dimensional particle-in-cell simulation. Simulation results show that
strong electrostatic waves are excited via the electron-ion electrostatic
two-stream instability at the leading edge of the shock transition region as in
the case of earlier one-dimensional simulations. We observe strong electron
acceleration that is associated with the turbulent electrostatic waves in the
shock transition region. The electron energy spectrum in the shock transition
region exhibits a clear power-law distribution with spectral index of $2.0 {\rm
-} 2.5$. By analyzing the trajectories of accelerated electrons, we find that
the acceleration mechanism is very similar to shock surfing acceleration of
ions. In contrast to the ion shock surfing, however, the energetic electrons
are reflected by electron-scale electrostatic fluctuations in the shock
transition region, but not by the ion-scale cross-shock electrostatic
potential. The reflected electrons are then accelerated by the convective
electric field in front of the shock. We conclude that the multidimensional
effects as well as the self-consistent shock structure are essential for the
strong electron acceleration at high Mach number shocks.


title: Systematic effects in apparent proper motion of radio sources

abstract:
  The galactocentric rotation of the Solar system generates the systematic
effect in proper motions known as 'secular aberration drift'. This tiny effect
(about five microseconds per year) in the quasar proper motion can be measured
by VLBI. However, the motions of relativistic jets from the active
extragalactic nuclei can reach several hundred microseconds per year and mimic
the proper motion of the observed radio sources. These apparent motions exceed
the secular aberration drift by factor of 10-100. In this paper we search the
ways to overcome the difficulties and discuss our estimates of the secular
aberration drift using OCCAM software.


title: Time-Periodic Solutions of the Einstein's Field Equations

abstract:
  In this paper, we develop a new method to find the exact solutions of the
Einstein's field equations by using which we construct time-periodic solutions.
The singularities of the time-periodic solutions are investigated and some new
physical phenomena, such as the time-periodic event horizon, are found. The
applications of these solutions in modern cosmology and general relativity are
expected.


title: On a degenerate parabolic equation arising in pricing of Asian options

abstract:
  We study a certain one dimensional, degenerate parabolic partial differential
equation with a boundary condition which arises in pricing of Asian options.
Due to degeneracy of the partial differential operator and the non-smooth
boundary condition, regularity of the generalized solution of such a problem
remained unclear. We prove that the generalized solution of the problem is
indeed a classical solution.


title:
A note on the (anti-)BRST invariant Lagrangian densities for the free
  abelian 2-form gauge theory

abstract:
  We show that the previously known off-shell nilpotent (s_{(a)b}^2 = 0) and
absolutely anticommuting (s_b s_{ab} + s_{ab} s_b = 0)
Becchi-Rouet-Stora-Tyutin (BRST) transformations (s_b) and anti-BRST
transformations (s_{ab}) are the symmetry transformations of the appropriate
Lagrangian densities of a four (3 + 1)-dimensional (4D) free Abelian 2-form
gauge theory which do not explicitly incorporate a very specific constrained
field condition through a Lagrange multiplier 4D vector field. The above
condition, which is the analogue of the Curci-Ferrari restriction of the
non-Abelian 1-form gauge theory, emerges from the Euler-Lagrange equations of
motion of our present theory and ensures the absolute anticommutativity of the
transformations s_{(a)b}. Thus, the coupled Lagrangian densities, proposed in
our present investigation, are aesthetically more appealing and more
economical.


title:
A Characteristic Planetary Feature in Double-Peaked, High-Magnification
  Microlensing Events

abstract:
  A significant fraction of microlensing planets have been discovered in
high-magnification events, and a significant fraction of these events exhibit a
double-peak structure at their peak. However, very wide or very close binaries
can also produce double-peaked high-magnification events, with the same gross
properties as those produced by planets. Traditionally, distinguishing between
these two interpretations has relied upon detailed modeling, which is both
time-consuming and generally does not provide insight into the observable
properties that allow discrimination between these two classes of models. We
study the morphologies of these two classes of double-peaked high-magnification
events, and identify a simple diagnostic that can be used to immediately
distinguish between perturbations caused by planetary and binary companions,
without detailed modeling. This diagnostic is based on the difference in the
shape of the intra-peak region of the light curves. The shape is smooth and
concave for binary lensing, while it tends to be either boxy or convex for
planetary lensing. In planetary lensing this intra-peak morphology is due to
the small, weak cusp of the planetary central caustic located between the two
stronger cusps. We apply this diagnostic to five observed double-peaked
high-magnification events to infer their underlying nature. A corollary of our
study is that good coverage of the intra-peak region of double-peaked
high-magnification events is likely to be important for their unique
interpretation.


title: Lopsided galaxies: the case of NGC 891

abstract:
  It has been known for a long time that a large fraction of disc galaxies are
lopsided. We simulate three different mechanisms that can induce lopsidedness:
flyby interactions, gas accretion from cosmological filaments and ram pressure
from the intergalactic medium. Comparing the morphologies, HI spectrum,
kinematics and m=1 Fourier components, we find that all of these mechanisms can
induce lopsidedness in galaxies, although in different degrees and with
observable consequences. The timescale over which lopsidedness persists
suggests that flybys can contribute to ~20 per cent of lopsided galaxies. We
focus our detailed comparison on the case of NGC 891, a lopsided, edge-on
galaxy with a nearby companion (UGC 1807). We find that the main properties of
NGC 891 (morphology, HI spectrum, rotation curve, existence of a gaseous
filament pointing towards UGC 1807) favour a flyby event for the origin of
lopsidedness in this galaxy.


title: Theory of huge tunneling magnetoresistance in graphene

abstract:
  We investigate theoretically the spin-independent tunneling magnetoresistance
effect in a graphene monolayer modulated by two parallel ferromagnets deposited
on a dielectric layer. For the parallel magnetization configuration, Klein
tunneling can be observed in the transmission spectrum, but at specific oblique
incident angles. For the antiparallel magnetization configuration, the
transmission can be blocked by the magnetic-electric barrier provided by the
ferromagnets. Such a transmission discrepancy results in a tremendous
magnetoresistance ratio and can be tuned by the inclusion of an electric
barrier.


title:
Spin current diode based on an electron waveguide with spin-orbit
  interaction

abstract:
  We propose a spin current diode which can work even in a small applied bias
condition (the linear-response regime). The prototypal device consists of a
hornlike electron waveguide with Rashba spin-orbit interaction, which is
connected to two leads with different widths. It is demonstrated that when
electrons are incident from the narrow lead, the generated spin conductance
fluctuates around a constant value in a wide range of incident energy. When the
transport direction is reversed, the spin conductance is suppressed strongly.
Such a remarkable difference arises from spin-flipped transitions caused by the
spin-orbit interaction.


title:
Coherent control of spontaneous emission of a three-level atom in a
  coherent photonic band gap reservoir

abstract:
  By studying the fluorescence and optical properties of a three-level system,
we propose a new point of view on the coherent control of these spectra. With
the definite phase difference between the fields of the air band and dielectric
band in photonic band gap (PBG) reservoirs, the spectra of spontaneous
emission, absorption, and dispersion exhibit the coherent property and quantum
interference effect. This coherent interference depending on the position of
the embedded atom and the width of band gap causes the coupling of the
free-space light and the PBG light to result in blue shift of spectra and the
appearance of dark lines and kinks. By coherently controlling the
position-dependent dispersion, we can tune the frequency of slow light.


title: Self-similar cosmologies in 5D: spatially flat anisotropic models

abstract:
  In the context of theories of Kaluza-Klein type, with a large extra
dimension, we study self-similar cosmological models in 5D that are
homogeneous, anisotropic and spatially flat. The "ladder" to go between the
physics in 5D and 4D is provided by Campbell-Maagard's embedding theorems. We
show that the 5-dimensional field equations $R_{AB} = 0$ determine the form of
the similarity variable. There are three different possibilities: homothetic,
conformal and "wave-like" solutions in 5D. We derive the most general
homothetic and conformal solutions to the 5D field equations. They require the
extra dimension to be spacelike, and are given in terms of one arbitrary
function of the similarity variable and three parameters. The Riemann tensor in
5D is not zero, except in the isotropic limit, which corresponds to the case
where the parameters are equal to each other. The solutions can be used as 5D
embeddings for a great variety of 4D homogeneous cosmological models, with and
without matter, including the Kasner universe. Since the extra dimension is
spacelike, the 5D solutions are invariant under the exchange of spatial
coordinates. Therefore they also embed a family of spatially {\it
inhomogeneous} models in 4D. We show that these models can be interpreted as
vacuum solutions in braneworld theory. Our work (I) generalizes the 5D
embeddings used for the FLRW models; (II) shows that anisotropic cosmologies
are, in general, curved in 5D, in contrast with FLRW models which can always be
embedded in a 5D Riemann-flat (Minkowski) manifold; (III) reveals that
anisotropic cosmologies can be curved and devoid of matter, both in 5D and 4D,
even when the metric in 5D explicitly depends on the extra coordinate, which is
quite different from the isotropic case.


title:
Broadband dielectric spectroscopy of mixed $CuInP_2(S_xSe_{1-x})_6$
  crystals

abstract:
  In this article mixed CuInP$_2$(S$_x$Se$_{1-x}$)$_6$ crystals were
investigated by broadband dielectric spectroscopy (20 Hz - 3 GHz). The complete
phase diagram has been obtained from these results. The phase diagram of
investigated crystals is strongly asymmetric - the decreasing of ferroelectric
phase transition temperatures in CuInP$_2$(S$_x$Se$_{1-x}$)$_6$ is much more
flat with small admixture of sulphur then with small admixture of selenium. In
the middle part of the phase diagram (x=0.4-0.9) the dipolar glass phase has
been observed. In boundary region between ferroelectric order and dipolar glass
disorder with small amount of sulphur (x=0.2-0.25) at low temperatures the
nonergodic relaxor phase appears. The phase diagram was discussed in terms of
random bonds and random fields.


title:
Orbital periods of cataclysmic variables identified by the SDSS. IV.
  SDSS J220553.98+115553.7 has stopped pulsating

abstract:
  We present time-series VLT spectroscopy and NTT photometry of the cataclysmic
variable SDSS J220553.98+115553.7, which contains a pulsating white dwarf. We
determine a spectroscopic orbital period of 82.825 +/- 0.089 min from velocity
measurements of the Halpha emission line. A period analysis of the light curves
reveals a dominant periodicity at 44.779 +/- 0.038 min which is not related to
the spectroscopic period. However, the light curves do not exhibit a variation
at any frequency which is attributable to GW Lib type pulsations, to a
detection limit of 5 mmag. This non-detection is in contrast to previous
studies which have found three pulsation frequencies with amplitudes of 9 to 11
mmag at optical wavelengths. Destructive interference and changes to the
thermal properties of the driving layer in direct response to accretion can be
ruled out as causes of the non-detection. Alternatively, it is feasible that
the object has cooled out of the instability strip since a previous
(unobserved) dwarf nova superoutburst. This would be the first time this
behaviour has been seen in a cataclysmic variable pulsator. Another possibility
is that changes in the surface characteristics, possibly induced by accretion
phenomena, have modified the surface visibility of the pulsation modes. Further
observations, particularly improved constraints on the timescale for changes in
the mode spectrum, are needed to distinguish among possible explanations.


title:
Characterisation of nanostructured GaSb : Comparison between large-area
  optical and local direct microscopic techniques

abstract:
  Low energy ion-beam sputtering of GaSb results in self-organized
nanostructures, with the potential of structuring large surface areas.
Characterisation of such nanostructures by optical methods is studied and
compared to direct (local) microscopic methods. The samples consist of densely
packed GaSb cones on bulk GaSb, approximately 30, 50 and 300 nm in height,
prepared by sputtering at normal incidence. The optical properties are studied
by spectroscopic ellipsometry, in the range 0.6-6.5 eV, and with Mueller matrix
ellipsometry in the visible range, 1.46-2.88 eV. The optical measurements are
compared to direct topography measurements obtained by Scanning Electron
Microscopy (SEM), High Resolution Transmission Electron Microscopy (HR-TEM),
and Atomic Force Microscopy (AFM). Good agreement is achieved between the two
classes of methods when the experimental optical response of the short cones
(<55 nm) is inverted with respect to topological surface information via a
graded anisotropic effective medium model. The main topological parameter
measured was the average cone height, but estimates of typical cone shape and
density (in terms of volume fractions) were also obtained. The graded
anisotropic effective medium model treats the cones as a stack of concentric
cylinders (discs) of non-increasing radii. Optical methods are shown to
represent a valuable characterization tool for nanostructured surfaces, in
particular when large coverage area is desirable. Due to the fast and
non-destructive properties of optical techniques, they may readily be adapted
to in-situ configurations.


title:
Electronic Structure, Phonons and Dielectric Anomaly in Ferromagnetic
  Insulating Double Perovskite La2NiMnO6

abstract:
  Using first-principles density functional calculations, we study the
electronic and magnetic properties of ferromagnetic insulating
double-perovskite compound La2NiMnO6, which has been reported to exhibit
interesting magnetic field sensitive dielectric anomaly as a function of
temperature. Our study reveals existence of very soft infra-red active phonons
that couple strongly with spins at the Ni and Mn sites through modification of
the super-exchange interaction. We suggest that these modes are the origin for
observed dielectric anomaly in La2NiMnO6.


title:
Electron spin resonance signal of Luttinger liquids and single-wall
  carbon nanotubes

abstract:
  A comprehensive theory of electron spin resonance (ESR) for a Luttinger
liquid (LL) state of correlated metals is presented. The ESR measurables such
as the signal intensity and the line-width are calculated in the framework of
Luttinger liquid theory with broken spin rotational symmetry as a function of
magnetic field and temperature. We obtain a significant temperature dependent
homogeneous line-broadening which is related to the spin symmetry breaking and
the electron-electron interaction. The result crosses over smoothly to the ESR
of itinerant electrons in the non-interacting limit. These findings explain the
absence of the long-sought ESR signal of itinerant electrons in single-wall
carbon nanotubes when considering realistic experimental conditions.


title:
The impedance-matched reduced acoustic cloaking with realizable mass and
  its layered design

abstract:
  The authors present an impedance-matched reduced version of acoustic cloaking
whose mass is in a reasonable range. A layered cloak design with isotropic
material is also proposed for the reduced cloak. Numerical calculations from
the transfer matrix methods show that the present layered cloak can reduce the
scattering of an air cylinder substantially.


title: Neutral Higgs bosons in the MNMSSM with explicit CP violation

abstract:
  Within the framework of the minimal non-minimal supersymmetric standard model
(MNMSSM) with tadpole terms, CP violation effects in the Higgs sector are
investigated at the one-loop level, where the radiative corrections from the
loops of the quark and squarks of the third generation are taken into account.
Assuming that the squark masses are not degenerate, the radiative corrections
due to the stop and sbottom quarks give rise to CP phases, which trigger the CP
violation explicitly in the Higgs sector of the MNMSSM. The masses, the
branching ratios for dominant decay channels, and the total decay widths of the
five neutral Higgs bosons in the MNMSSM are calculated in the presence of the
explicit CP violation. The dependence of these quantities on the CP phases is
quite recognizable, for given parameter values.


title:
An Algorithm For Photometric Identification Of Transiting Circumbinary
  Planets

abstract:
  Transiting planets manifest themselves by a periodic dimming of their host
star by a fixed amount. On the other hand, light curves of transiting
circumbinary (CB) planets are expected to be neither periodic nor to have a
single depth while in transit. These propertied make the popular transit
finding algorithm BLS almost ineffective so a modified version of BLS for the
identification of CB planets was developed - CB-BLS. We show that using this
algorithm it is possible to find CB planets in the residuals of light curves of
eclipsing binaries that have noise levels of 1% and more - quality that is
routinely achieved by current ground-based transit surveys. Previous searches
for CB planets using variation of eclipse times minima of CM Dra and elsewhere
are more closely related to radial velocity than to transit searches and so are
quite distinct from CB-BLS. Detecting CB planets is expected to have
significant impact on our understanding of exoplanets in general, and exoplanet
formation in particular. Using CB-BLS will allow to easily harness the massive
ground- and space- based photometric surveys in operation to look for these
hard-to-find objects.


title: First-order formalism for the quintom model of dark energy

abstract:
  The present paper deals to the quintom model of dark energy. We introduce a
first-order formalism, which shows how to relate the potential that specifies
the scalar field model to Hubble parameter. Reviewing briefly the quintom
scenario of dark energy, we present a general procedure to solve the equations
of motion for quintom model driven by a couple scalar fields with first-order
differential equations.


title:
On using the WMAP distance priors in constraining the time evolving
  equation of state of dark energy

abstract:
  Recently, the WMAP group has published their five-year data and considered
the constraints on the time evolving equation of state of dark energy for the
first time from the WMAP distance information. In this paper, we study the
effectiveness of the usage of these distance information and find that these
compressed CMB information can give similar constraints on dark energy
parameters compared with the full CMB power spectrum if dark energy
perturbations are included, however, once incorrectly neglecting the dark
energy perturbations, the difference of the results are sizable.


title:
Search for a promising tetraquark candidate $X(ud\bar{s}\bar{s})$ in
  $pn\to \Lambda\Lambda X$

abstract:
  We propose to search for a tetraquark candidate $X(ud\bar{s}\bar{s})$ in
$pn\to \Lambda\Lambda X(ud\bar{s}\bar{s})\to \Lambda\Lambda K^+K^0$ or
$\Lambda\Lambda KK^*$. The existence of tetraquark state $X(ud\bar{s}\bar{s})$
with $J^P=0^+$, $1^-$ or $1^+$ was predicted in the literature based on
specific diquark effective degrees of freedom inside hadrons. In order to
understand the underlying dynamics for exotic hadrons, a search for the
tetraquark $X(ud\bar{s}\bar{s})$ is strongly recommended. The proposed reaction
involves two $\Lambda$ production, of which the narrow widths make it a great
advantage in the analysis of the final state missing mass spectrum. We make an
estimate of the production rate of $X(ud\bar{s}\bar{s})$ in an effective
Lagrangian theory and find that for $J^P=1^-$ the sample events of $\sim 2200 \
nb^{-1}$ will be able to identify $X(ud\bar{s}\bar{s})$ with five standard
deviations at a width of 10 MeV to $K^+K^0$ near threshold. For $J^P=1^+$ with
a width of 20 MeV to $KK^*$, the sample events of $\sim 130 nb^{-1}$ will be
needed. Large production cross sections are expected in a kinematic region
beyond the threshold. We emphasize the advantage of low background in this
transition channel, and in the meantime caution the large uncertainties in the
present estimate due to lack of knowledge about the $X(ud\bar{s}\bar{s})$
state. Implications for its heavy-flavored partners $qq\bar{c}\bar{c}$ and
$qq\bar{b}\bar{b}$ are briefly discussed.


title:
Anomalous Hall Effect in Magnetite: Universal Scaling Relation Between
  Hall and Longitudinal Conductivity in Low-Conductivity Ferromagnets

abstract:
  The anomalous Hall effect (AHE) has been studied systematically in the
low-conductivity ferromagnetic oxide Fe$_{3-x}$Zn$_x$O$_4$ with $x = 0$, 0.1,
and 0.5. We used (001), (110), and (111) oriented epitaxial
Fe$_{3-x}$Zn$_x$O$_4$ films grown on MgO and sapphire substrates in different
oxygen partial pressure to analyze the dependence of the AHE on
crystallographic orientation, Zn content, strain state, and oxygen deficiency.
Despite substantial differences in the magnetic properties and magnitudes of
the anomalous Hall conductivity $\sigma_{xy}^{\rm AHE}$ and the longitudinal
conductivity $\sigma_{xx}$ over several orders of magnitude, a universal
scaling relation $\sigma_{xy}^{\rm AHE} \propto \sigma_{xx}^{\alpha}$ with
$\alpha = 1.69 \pm 0.08$ was found for all investigated samples. Our results
are in agreement with recent theoretical and experimental findings for
ferromagnetic metals in the dirty limit, where transport is by metallic
conduction. We find the same scaling relation for magnetite, where hopping
transport prevails. The fact that this relation is independent of
crystallographic orientation, Zn content, strain state, and oxygen deficiency
suggests that it is universal and particularly does not depend on the nature of
the transport mechanism.


title: Fluorine in carbon-enhanced metal-poor stars: a binary scenario

abstract:
  A super-solar fluorine abundance was observed in the carbon-enhanced
metal-poor (CEMP) star HE 1305+0132 ([F/Fe] = +2.90, [Fe/H] = -2.5). We propose
that this observation can be explained using a binary model that involve mass
transfer from an asymptotic giant branch (AGB) star companion and, based on
this model, we predict F abundances in CEMP stars in general. We discuss wether
F can be used to discriminate between the formation histories of most CEMP
stars: via binary mass transfer or from the ejecta of fast-rotating massive
stars. We compute AGB yields using different stellar evolution and
nucleosynthesis codes to evaluate stellar model uncertainties. We use a simple
dilution model to determine the factor by which the AGB yields should be
diluted to match the abundances observed in HE 1305+0132. We further employ a
binary population synthesis tool to estimate the probability of F-rich CEMP
stars. The abundances observed in HE 1305+0132 can be explained if this star
accreted 3-11% of the mass lost by its former AGB companion. The primary AGB
star should have dredged-up at least 0.2 Msun of material from its He-rich
region into the convective envelope via third dredge-up, which corresponds to
AGB models of Z ~ 0.0001 and mass ~ 2 Msun. Many AGB model uncertainties, such
as the treatment of convective borders and mass loss, require further
investigation. We find that in the binary scenario most CEMP stars should also
be FEMP stars, that is, have [F/Fe] > +1, while fast-rotating massive stars do
not appear to produce fluorine. We conclude that fluorine is a signature of
low-mass AGB pollution in CEMP stars, together with elements associated with
the slow neutron-capture process.


title:
Electroweak and supersymmetric two-loop corrections to lepton anomalous
  magnetic and electric dipole moments

abstract:
  Using the effective Lagrangian method, we analyze the electroweak corrections
to the anomalous dipole moments of lepton from some special two-loop diagrams
where a closed neutralino/chargino loop is inserted into relevant two Higgs
doublet one-loop diagrams in the minimal supersymmetric extension of the
standard model with CP violation. Considering the translational invariance of
loop momenta and the electromagnetic gauge invariance, we get all dimension 6
operators and derive their coefficients. After applying equations of motion to
the external leptons, we obtain the anomalous dipole moments of lepton. The
numerical results imply that there is parameter space where the contributions
to the muon anomalous dipole moments from this sector may be significant.


title:
Measurement and control of spatial qubits generated by passing photons
  through double-slits

abstract:
  We present an experimental study of the non-classical correlations of a pair
of spatial qubits formed by passing two down-converted photons through a pair
of double slits. After confirming the entanglement generated in our setup by
quantum tomography using separate measurements of the slit images and the
interference patterns, we show that the complete Hilbert space of the spatial
qubits can be accessed by measurements performed in a single plane between the
image plane and the focal plane of a lens. Specifically, it is possible to
obtain both the which-path and the interference information needed for quantum
tomography in a single scan of the transversal distribution of photon
coincidences. Since this method can easily be extended to multi-dimensional
systems, it may be a valuable tool in the application of spatial qudits to
quantum information processes.


title: Radio continuum imaging of the R CrA star-forming region with the ATCA

abstract:
  The aim of this study is to investigate the nature of radio sources
associated with young stellar objects (YSOs) belonging to the R CrA cluster. By
combining the centimetre radio data with the wealth of shorter wavelength data
accumulated recently we wish to refine estimates of the evolutionary stages of
the YSOs. Fluxes and spectral indices for the brightest radio sources were
derived from the observations at 3, 6, and 20 cm using the ATCA. Seven of
detected sources can be assigned to YSOs, which have counterparts in the
X-rays, infrared or submm. One of the YSOs, Radio Source 9, is a Class 0
candidate, and another, IRS 7B, is suggested to be in the Class 0/I transition
stage. IRS 7B is associated with extended radio lobes at 6 and 20 cm. The lobes
may have a gyrosynchrotron emission component, which could be understood in
terms of Fermi accleration in shocks. The Class I objects detected here seem to
be a mixed lot. One of these, the wide binary IRS 5, shows a negative spectral
index, rapid variability, and a high degree of circular polarisation with
$V/I\approx33$ % on one of the days of observation. These signs of magnetic
activity suggest that at least one of the binary components has advanced beyond
the Class I stage. The radio source without YSO assigment, Radio Source 5, has
been suggested to be a brown dwarf. The radio properties, in particular its
persistent strong emission, do not support this classification. The radio
characteristics of the detected YSOs roughly agree with the scheme where the
dominant emission mechanism changes with age. The heterogeneity of the Class I
group can possibly be explained by a drastic decline in the jet activity during
this stage, which also changes the efficiency of free-free absorption around
the protostar.


title:
Analyticity of Event Horizons of Five-Dimensional Multi-Black Holes with
  Non-Trivial Asymptotic Structure

abstract:
  We show that there exist five-dimensional multi-black hole solutions which
have analytic event horizons when the space-time has non-trivial asymptotic
structure, unlike the case of five-dimensional multi-black hole solutions in
asymptotically flat space-time.


title:
Dynamic force spectroscopy: analysis of reversible bond-breaking
  dynamics

abstract:
  The problem of diffusive bond-dissociation in a double well potential under
application of an external force is scrutinized. We compute the probability
distribution of rupture forces and present a detailed discussion of the
influence of finite rebinding probabilities on the dynamic force spectrum. In
particular, we focus on barrier crossing upon extension, i.e. under linearly
increased load, and upon relaxation starting from completely separated bonds.
For large loading rates the rupture force and the rejoining force depend on the
loading rate in the expected manner determined by the shape of the potential.
For small loading rates the mean forces obtained from pull and relax modes
approach each other as the system reaches equilibrium. We investigate the
dependence of the rupture force distributions and mean rupture forces on
external parameters like cantilever stiffness and influence of a soft linker.
We find that depending on the implementation of a soft linker the equilibrium
rupture force is either unaffected by the presence of the linker or changes in
a predictable way with the linker-compliance. Additionally, we show that it is
possible to extract the equilibrium constant of the on- and off-rates from the
determination of the equilibrium rupture forces.


title: Sizes of flaring kernels in various parts of the H-alpha line profile

abstract:
  In this paper we present new results of spectraphotometrical investigations
of the flaring kernels sizes and their intensities measured simultaneously in
various parts of the H-alpha line profile. Our investigations were based on the
very high temporal resolution spectral-imaging observations of the solar flares
collected with Large Coronagraph (LC), Multi-channel Subtractive Double Pass
Spectrograph and Solar Eclipse Coronal Imaging System (MSDP-SECIS) at Bialkow
Observatory (University of Wroclaw, Poland). We have found that the areas of
the investigated individual flaring kernels vary in time and in wavelengths as
well as the intensities and areas of the H-alpha flaring kernels decreased
systematically when observed in consecutive wavelengths toward the wings of the
H-alpha line. Our result could be explained as an effect of the cone-shaped
lower parts of the magnetic loops channeling high energy particle beams
exciting chromospheric plasma.


title: An algebraic hypothesis about the primeval genetic code

abstract:
  A plausible architecture of an ancient genetic code is derived from an
extended base triplet vector space over the Galois field of the extended base
alphabet {D, G, A, U, C}, where the letter D represents one or more
hypothetical bases with unspecific pairing. We hypothesized that the high
degeneration of a primeval genetic code with five bases and the gradual origin
and improvements of a primitive DNA repair system could make possible the
transition from the ancient to the modern genetic code. Our results suggest
that the Watson-Crick base pairing and the non-specific base pairing of the
hypothetical ancestral base D used to define the sum and product operations are
enough features to determine the coding constraints of the primeval and the
modern genetic code, as well as, the transition from the former to the later.
Geometrical and algebraic properties of this vector space reveal that the
present codon assignment of the standard genetic code could be induced from a
primeval codon assignment.Besides, the Fourier spectrum of the extended DNA
genome sequences derived from the multiple sequence alignment suggests that the
called period-3 property of the present coding DNA sequences could also exist
in the ancient coding DNA sequences.


title: Electroweak & QCD corrections to Drell Yan processes

abstract:
  The relevance of single-W and single-Z production processes at hadron
colliders is well known: in the present paper the status of theoretical
calculations of Drell-Yan processes is summarized and some results on the
combination of electroweak and QCD corrections to a sample of observables of
the process $p p \to W^\pm \to \mu^\pm + X$ at the LHC are discussed. The
phenomenological analysis shows that a high-precision knowledge of QCD and a
careful combination of electroweak and strong contributions is mandatory in
view of the anticipated LHC experimental accuracy. One of the authors (O.N.)
dedicates these notes to Prof. S. Jadach, in honour of his 60th birthday and
grateful for all that Prof. Jadach taught him during their fruitful
collaboration.


title:
On the Convergence Time of the Best Response Dynamics in Player-specific
  Congestion Games

abstract:
  We study the convergence time of the best response dynamics in
player-specific singleton congestion games. It is well known that this dynamics
can cycle, although from every state a short sequence of best responses to a
Nash equilibrium exists. Thus, the random best response dynamics, which selects
the next player to play a best response uniformly at random, terminates in a
Nash equilibrium with probability one. In this paper, we are interested in the
expected number of best responses until the random best response dynamics
terminates.
  As a first step towards this goal, we consider games in which each player can
choose between only two resources. These games have a natural representation as
(multi-)graphs by identifying nodes with resources and edges with players. For
the class of games that can be represented as trees, we show that the
best-response dynamics cannot cycle and that it terminates after O(n^2) steps
where n denotes the number of resources. For the class of games represented as
cycles, we show that the best response dynamics can cycle. However, we also
show that the random best response dynamics terminates after O(n^2) steps in
expectation.
  Additionally, we conjecture that in general player-specific singleton
congestion games there exists no polynomial upper bound on the expected number
of steps until the random best response dynamics terminates. We support our
conjecture by presenting a family of games for which simulations indicate a
super-polynomial convergence time.


title: Sufficient conditions for superstability of many-body interactions

abstract:
  A detailed analysis of necessary conditions on a family of many-body
potentials, which ensure stability, superstability or strong superstability of
a statistical system is given in present work.There has been given also an
example of superstable many-body interaction.


title:
Absence of self-averaging and of homogeneity in the large scale galaxy
  distribution

abstract:
  The properties of the galaxy distribution at large scales are usually studied
using statistics which are assumed to be self-averaging inside a given sample.
We present a new analysis able to quantitatively map galaxy large scale
structures while testing for the stability of average statistical quantities in
different sample regions. We find that the newest samples of the Sloan Digital
Sky Survey provide unambiguous evidence that galaxy structures correspond to
large amplitude density fluctuations at all scales limited only by sample
sizes. The two-point correlations properties are self-averaging up to
approximately 30 Mpc/h and are characterized by a fractal dimension D=2.1 +-
0.1. Then at all larger scales probed density fluctuations are too large in
amplitude and too extended in space to be self-averaging inside the considered
volumes. These inhomogeneities are compatible with a continuation of fractal
correlations but incompatible with: (i) a homogeneity scale smaller than 100
Mpc/h, (ii) predictions of standard theoretical models, (iii) mock galaxy
catalogs generated from cosmological Nbody simuations.


title: High Energy Cosmic Rays from the Decay of Gravitino Dark Matter

abstract:
  We study gamma ray and positron in high energy cosmic ray from the decay of
the gravitino dark matter in the framework of supersymmetric model with
R-parity violation. Even though R-parity is violated, the lifetime of the
gravitino, which is assumed to be the lightest superparticle, can be longer
than the present age of the universe if R-parity violating interactions are
weak enough. In such a case, gravitino can be dark matter of the universe and
its decay produces high energy cosmic rays. We calculate the fluxes of gamma
ray and positron from the decay of the gravitino dark matter and discuss
implications of such a scenario to present and future observations. In
particular, we show that excesses of the fluxes of gamma ray and positron
observed by EGRET and HEAT experiments, respectively, can be simultaneously
explained as the cosmic rays from the decay of the gravitino dark matter.


title: Role of the tetraquark in the chiral phase transition

abstract:
  We investigate the implications of a tetraquark field on chiral symmetry
restoration at nonzero temperature. In order for the chiral phase transition to
be cross-over, as shown by lattice QCD studies, a strong mixing between scalar
quarkonium and tetraquark fields is required. This leads to a light ($\sim0.4$
GeV), predominantly tetraquark state, and a heavy ($\sim1.2$ GeV),
predominantly quarkonium state in the vacuum, in accordance with recently
advocated interpretations of spectroscopy data. The mixing even increases with
temperature and leads to an interchange of the roles of the originally heavy,
predominantly quarkonium state and the originally light, predominantly
tetraquark state. Then, as expected, the scalar quarkonium is a light state
when becoming degenerate in mass with the pion as chiral symmetry is restored
at nonzero temperature.


title:
Electron transmission through step- and barrier-like potentials in
  graphene ribbons

abstract:
  The list of textbook tunneling formulas is extended by deriving exact
expressions for the transmission coefficient in graphene ribbons with armchair
edges and the step-like and barrier-like profiles of site energies along the
ribbon. These expressions are obtained by matching wave functions at the
interfaces between the regions, where quasiparticles have constant but
different potential energies. It is shown that for an $U_0$ high barrier and
low-energy electrons and holes, the mode transmission of charge carriers in
this type of ribbons is described by the textbook formula, where the constant
barrier is replaced by an effective, energy-dependent barrier, $U_0\to U(E)$.
For the lowest/highest electron/hole mode, $U(E)$ goes, respectively, to zero
and nonzero value in metallic and semiconducting ribbons. This and other
peculiarities of through-barrier/step transmission in graphene are discussed
and compared with related earlier results.


title:
Rotation of the swing plane of Foucault's pendulum and Thomas spin
  precession: Two faces of one coin

abstract:
  Using elementary geometric tools, we apply essentially the same methods to
derive expressions for the rotation angle of the swing plane of Foucault's
pendulum and the rotation angle of the spin of a relativistic particle moving
in a circular orbit (Thomas precession effect).


title:
The ghost of a dwarf galaxy: fossils of the hierarchical formation of
  the nearby spiral galaxy NGC 5907

abstract:
  We present an extragalactic perspective of an extended stellar tidal stream
wrapping around the edge-on, spiral galaxy NGC 5907. Our deep images reveal for
the first time a large scale complex of arcing loops that is an excellent
example of how a low-mass satellite accretion can produce an interwoven,
rosette-like structure of debris dispersed in the halo of its host galaxy. The
existence of this structure, which has probably formed and survived for several
Gigayears, confirms that halos of spiral galaxies in the Local Universe may
still contain a significant number of galactic fossils from their hierarchical
formation. To examine the validity of the external accretion scenario, we
present N-body simulations of the tidal disruption of a dwarf galaxy-like
system in a disk galaxy plus dark halo potential that demonstrate that most of
the observed tidal features observed in NGC 5907 can be explained by a single
accretion event. Unfortunately, with no kinematic data and only the projected
geometry of the stream as constraint, the parameters of our model are
considerably degenerate and, for now, must be considered illustrative only.
Interestingly, NGC 5907 has long been considered a prototypical example of a
warped spiral in relative isolation. The presence of an extended tidal stream
challenges this picture and suggests that the gravitational perturbations
induced by the stream progenitor may be the cause for the warp. The detection
of an old, complex tidal stream in a nearby galaxy with rather modest
instrumentation points to the viability of surveys to find extragalactic tidal
substructures around spiral galaxies in the Local Volume (< 15 Mpc) -- with the
prospect of obtaining a census with enough statistical significance to be
compared with cosmological simulations.


title:
Hydrodynamical simulations of Galactic fountains I: evolution of single
  fountains

abstract:
  The ejection of the gas out of the disk in late-type galaxies is related to
star formation and is due mainly to Type II supernovae. In this paper we
studied in detail the development of the Galactic fountains in order to
understand their dynamical evolution and their influence in the redistribution
of the freshly delivered metals over the disk. To this aim, we performed a
number of 3D hydrodynamical radiative cooling simulations of the gas in the
Milky Way where the whole Galaxy structure, the Galactic differential rotation
and the supernovae explosions generated by a single OB association are
considered. A typical fountain powered by 100 Type II supernovae may eject
material up to $\sim 2$ kpc which than collapses back mostly in form of dense,
cold clouds and filaments. The majority of the gas lifted up by the fountains
falls back on the disk remaining within a radial distance $\Delta R=0.5$ kpc
from the place where the fountain originated. This localized circulation of
disk gas does not influence the radial chemical gradients on large scale, as
required by the chemical models of the Milky Way which reproduce the
metallicity distribution without invoking large fluxes of metals. Simulations
of multiple fountains fuelled by Type II supernovae of different OB
associations will be presented in a companion paper.


title:
Absolute absorption on the rubidium D lines: comparison between theory
  and experiment

abstract:
  We study the Doppler-broadened absorption of a weak monochromatic probe beam
in a thermal rubidium vapour cell on the D lines. A detailed model of the
susceptibility is developed which takes into account the absolute linestrengths
of the allowed electric dipole transitions and the motion of the atoms parallel
to the probe beam. All transitions from both hyperfine levels of the ground
term of both isotopes are incorporated. The absorption and refractive index as
a function of frequency are expressed in terms of the complementary error
function. The absolute absorption profiles are compared with experiment, and
are found to be in excellent agreement provided a sufficiently weak probe beam
with an intensity under one thousandth of the saturation intensity is used. The
importance of hyperfine pumping for open transitions is discussed in the
context of achieving the weak-probe limit. Theory and experiment show excellent
agreement, with an rms error better than 0.2% for the D2 line at 16.5 degrees
C.


title: A Chebyshev criterion for Abelian integrals

abstract:
  We present a criterion that provides an easy sufficient condition in order
that a collection of Abelian integrals has the Chebyshev property. This
condition involves the functions in the integrand of the Abelian integrals and
can be checked, in many cases, in a purely algebraic way. By using this
criterion, several known results are obtained in a shorter way and some new
results, which could not be tackled by the known standard methods, can also be
deduced.


title:
Properties of synchronization in the systems of non-identical coupled
  van der Pol and van der Pol - Duffing oscillators. Broadband synchronization

abstract:
  The particular properties of dynamics are discussed for the dissipatively
coupled van der Pol oscillators, non-identical in values of parameters
controlling the Hopf bifurcation. Possibility of a special synchronization
regime in an infinitively long band between oscillation death and quasiperiodic
areas is shown for such system. Features of the bifurcation picture are
discussed for different values of the control parameters and for the case of
additional Duffing-type nonlinearity. Analysis of the abridged equations is
presented.


title:
The Fundamental Plane for early-type galaxies. Dependence on the
  magnitude range

abstract:
  Studying 3 samples of early-type galaxies, which include approximately 8800
galaxies and cover a relatively ample magnitude range ($<\Delta M>$ $\sim 5$
$mag$), we find that the coefficients as well as the intrinsic dispersion of
the Fundamental Plane depend on the width of the magnitude range within which
the galaxies are distributed. We analyse this dependence and the results show
that it could be due to the fact that the distribution of galaxies in the space
defined by the variables $\log (r_{e}), <\mu>_{e}, \log(\sigma)$ depends on the
luminosity.


title: AGB stars as tracers of metallicity and mean age across M33

abstract:
  Wide-field JHKs near-infrared observations covering an area of 1.8x1.8 sq.
deg. centred on M33 were obtained using WFCAM at UKIRT. These data show a large
population of intermediate-age asymptotic giant branch stars (AGB). We have
used both C-type and M-type AGB stars to determine spatial variations in
metallicity and mean age across the galaxy. We distinguished between C-type and
M-type AGB stars from their location in the colour-magnitude diagram (J-Ks,
Ks). The distribution of these stars is supported by a cross-identification
between our sample and a catalogue of optically confirmed, long-period variable
stars, as well as with the list of sources detected by Spitzer in the
mid-infrared. We calculated the C/M ratio and the orientation of the galaxy in
the sky, and compared the Ks magnitude distribution with theoretical
distributions spanning a range of metallicities and star formation rates
(SFRs). The C/M ratio surface map confirms a metallicity gradient in the galaxy
corresponding to a spread in [Fe/H]=0.6 dex with substructures in the inner and
outer galaxy. Magnitude and colour variations suggest orientation and
extinction effects on the galaxy disc. Maps showing the distribution of mean
age and metallicity obtained from the Ks method suggest that: the outer galaxy
disc/halo is metal poorer than the nuclear region and metal-rich clumps in the
inner galaxy change location with time. The average outer ring and nuclear
stellar population is ~6 Gyr old while central regions are a few Gyr younger.


title: f-Vectors of 3-Manifolds

abstract:
  In 1970, Walkup completely described the set of $f$-vectors for the four
3-manifolds $S^3$, $S^2 twist S^1$, $S^2 \times S^1$, and $RP^3$. We improve
one of Walkup's main restricting inequalities on the set of $f$-vectors of
3-manifolds. As a consequence of a bound by Novik and Swartz, we also derive a
new lower bound on the number of vertices that are needed for a combinatorial
$d$-manifold in terms of its $\beta_1$-coefficient, which partially settles a
conjecture of K\"uhnel. Enumerative results and a search for small
triangulations with bistellar flips allow us, in combination with the new
bounds, to completely determine the set of $f$-vectors for twenty further
3-manifolds, that is, for the connected sums of sphere bundles $(S^2 \times
S^1)^{# k}$ and twisted sphere bundles $(S^2 twist S^1)^{# k}$, where
$k=2,3,4,5,6,7,8,10,11,14$. For many more 3-manifolds of different geometric
types we provide small triangulations and a partial description of their set of
$f$-vectors. Moreover, we show that the 3-manifold $RP^3 # RP^3$ has (at least)
two different minimal $g$-vectors.


title:
The relation between star formation, morphology and local density in
  high redshift clusters and groups

abstract:
  We investigate how the [OII] properties and the morphologies of galaxies in
clusters and groups at z=0.4-0.8 depend on projected local galaxy density, and
compare with the field at similar redshifts and clusters at low-z. In both
nearby and distant clusters, higher-density regions contain proportionally
fewer star-forming galaxies, and the average [OII] equivalent width of
star-forming galaxies is independent of local density. However, in distant
clusters the average current star formation rate (SFR) in star-forming galaxies
seems to peak at densities ~15-40 galaxies Mpc^{-2}. At odds with low-z
results, at high-z the relation between star-forming fraction and local density
varies from high- to low-mass clusters. Overall, our results suggest that at
high-z the current star formation (SF) activity in star-forming galaxies does
not depend strongly on global or local environment, though the possible SFR
peak seems at odds with this conclusion. We find that the cluster SFR
normalized by cluster mass anticorrelates with mass and correlates with the
star-forming fraction. These trends can be understood given a) that the average
star-forming galaxy forms about 1 Msun/yr in all clusters; b) that the total
number of galaxies scales with cluster mass and c) the dependence of
star-forming fraction on cluster mass. We present the morphology-density (MD)
relation for our z=0.4-0.8 clusters, and uncover that the decline of the spiral
fraction with density is entirely driven by galaxies of types Sc or later. For
galaxies of a given Hubble type, we see no evidence that SF properties depend
on local environment. In contrast with recent findings at low-z, in our distant
clusters the SF-density relation and the MD-relation are equivalent, suggesting
that neither of the two is more fundamental than the other.(abr.)


title:
Effective Hamiltonian for fluid membranes in the presence of long-ranged
  forces

abstract:
  If the constituent particles of fluid phases interact via long-ranged van der
Waals forces, the effective Hamiltonian for \emph{interfaces} between such
fluid phases contains - in lateral Fourier space - non-analytic terms $ \sim
q^4 \ln q$. Similar non-analytic terms characterize the effective Hamiltonian
for two interacting interfaces which can emerge between the three possible
coexisting fluid phases in binary liquid mixtures. This is in contrast with the
structure of the phenomenological Helfrich Hamiltonian for membranes which does
not contain such non-analytic terms. We show that under favorable conditions
for the bulk densities characterizing a binary liquid mixture and for the
long-ranged interparticle interactions the corresponding effective Hamiltonian
for a model fluid \emph{membrane} does not exhibit such non-analytic
contributions. We discuss the properties of the resulting effective
Hamiltonian, with a particular emphasis on the influence of the long range of
the interactions on the coefficient of the bending rigidity.


title: A cellular algebra with certain idempotent decomposition

abstract:
  For a cellular algebra $\A$ with a cellular basis $\ZC$, we consider a
decomposition of the unit element $1_\A$ into orthogonal idempotents (not
necessary primitive) satisfying some conditions. By using this decomposition,
the cellular basis $\ZC$ can be partitioned into some pieces with good
properties. Then by using a certain map $\a$, we give a coarse partition of
$\ZC$ whose refinement is the original partition. We construct a Levi type
subalgebra $\aA$ of $\A$ and its quotient algebra $\oA$, and also construct a
parabolic type subalgebra $\tA$ of $\A$, which contains $\aA$ with respect to
the map $\a$. Then, we study the relation of standard modules, simple modules
and decomposition numbers among these algebras. Finally, we study the
relationship of blocks among these algebras.


title:
Comparisons between isothermal and NFW mass profiles for strong-lensing
  galaxy clusters

abstract:
  While both isothermal and NFW-based mass models for galaxy clusters are
widely adopted in strong-lensing studies, they cannot easily be distinguished
based solely on observed positions of arcs and arclets. We compare the
magnifications predicted for giant arcs obtained from isothermal and NFW
profiles, taking axially-symmetric and asymmetric mass distributions into
account. We find that arc magnifications can differ strongly between the two
types of density profiles even if the image morphology is well reproduced.
Magnifications by lenses with NFW density profiles are usually larger than
those for lenses with singular or nearly singular isothermal density profiles,
unless the latter have large cores. Asymmetries play an important role. We
illustrate our results with the two well-studied clusters MS 2137 and A~370. We
confirm earlier results showing that both isothermal and NFW mass models can
very well reproduce the observed arcs, radial arcs and other arclets. While the
mass model for MS 2137 is not very well constrained, the two types of mass
models produce strongly differing critical curves and caustics for A~370. We
find that the NFW mass profile is preferred for A~370. We identify new arclet
candidates in the field of A~370. Redshift estimates allowed by the lens model
are consistent with results in the literature, where available. Three newly
found counter-images are suggested to arise from an active, dust-enshrouded
star-forming galaxy at $z\approx1.1$.


title: Superluminality in the Fierz--Pauli massive gravity

abstract:
  We study the propagation of helicity-1 gravitons in the Fierz--Pauli massive
gravity in nearly Minkowski backgrounds. We show that, generically, there exist
backgrounds consistent with field equations, in which the propagation is
superluminal. The relevant distances are much longer than the ultraviolet
cutoff length inherent in the Fierz--Pauli gravity, so superluminality occurs
within the domain of validity of the effective low energy theory. There remains
a possibility that one may get rid of this property by imposing fine tuning
relations between the coefficients in the non-linear generalization of the
Fierz--Pauli mass term, order by order in non-linearity; however, these
relations are not protected by any obvious symmetry. Thus, among others,
superluminality is a problematic property to worry about when attempting to
construct infrared modifications of General Relativity.


title: Unparticle effects in rare (t -> c g g) decay

abstract:
  Rare (t -> c g g) decay can only appear at loop level in the Standard Model
(SM), and naturally they are strongly suppressed. These flavor changing decays
induced by the mediation of spin-0 and spin-2 unparticles, can appear at tree
level in unparticle physics. In this work the virtual effects of unparticle
physics in the flavor-changing (t -> c g g) decay is studied. Using the SM
result for the branching ratio of the (t -> c g g) decay, the parameter space
of d_U and Lambda_U, where the branching ratio of this decay exceeds the one
predicted by the SM, is obtained. Measurement of the branching ratio larger
than 10^(-9) can give valuable information for establishing unparticle physics.


title:
Enhanced low-temperature entropy and flat-band ferromagnetism in the t-J
  model on the sawtooth lattice

abstract:
  Using the example of the sawtooth chain, we argue that the t-J model shares
important features with the Hubbard model on highly frustrated lattices. The
lowest single-fermion band is completely flat (for a specific choice of the
hopping parameters $t_{i,j}$ in the case of the sawtooth chain), giving rise to
single-particle excitations which can be localized in real space. These
localized excitations do not interact for sufficient spatial separations such
that exact many-electron states can also be constructed. Furthermore, all these
excitations acquire zero energy for a suitable choice of the chemical potential
$\mu$. This leads to: (i) a jump in the particle density at zero temperature,
(ii) a finite zero-temperature entropy, (iii) a ferromagnetic ground state with
a charge gap when the flat band is fully occupied and (iv) unusually large
temperature variations when $\mu$ is varied adiabatically at finite
temperature.


title: The real analytic Feigenbaum-Coullet-Tresser attractor in the disk

abstract:
  We consider a real analytic diffeomorphism $\psi_0$ on a n-dimensional disk
D, n >= 2, exhibiting a Feigenbaum-Coullet-Tresser (F.C.T.) attractor, being
far, in the standard topology of the real analytic diffeomorphism space C(D),
from the standard F.C.T. map $\phi_0$ fixed by the double renormalization. We
prove that $\psi_0$ persists along a codimension-one manifold M \subset C(D),
and that it is the bifurcating map along any one-parameter family in $C(D)$
transversal to M, from diffeomorphisms attracted to sinks, to those which
exhibit chaos. The main tool in the proofs is a theorem of Functional Analysis,
which we state and prove in this paper, characterizing the existence of
codimension one submanifolds in any abstract functional Banach space.


title: Contact state analysis using NFIS and SOM

abstract:
  This paper reports application of neuro- fuzzy inference system (NFIS) and
self organizing feature map neural networks (SOM) on detection of contact state
in a block system. In this manner, on a simple system, the evolution of contact
states, by parallelization of DDA, has been investigated. So, a comparison
between NFIS and SOM results has been presented. The results show applicability
of the proposed methods, by different accuracy, on detection of contact's
distribution.


title: Clustering of scientific citations in Wikipedia

abstract:
  The instances of templates in Wikipedia form an interesting data set of
structured information. Here I focus on the cite journal template that is
primarily used for citation to articles in scientific journals. These citations
can be extracted and analyzed: Non-negative matrix factorization is performed
on a (article x journal) matrix resulting in a soft clustering of Wikipedia
articles and scientific journals, each cluster more or less representing a
scientific topic.


title:
Spin Hall effect in a two-dimensional electron gas in the presence of a
  magnetic field

abstract:
  We study the spin Hall effect of a two-dimensional electron gas in the
presence of a magnetic field and both the Rashba and Dresselhaus spin-orbit
interactions. We show that the value of the spin Hall conductivity, which is
finite only if the Zeeman spin splitting is taken into account, may be tuned by
varying the ratio of the in-plane and out-of-plane components of the applied
magnetic field. We identify the origin of this behavior with the different role
played by the interplay of spin-orbit and Zeeman couplings for in-plane and
out-of-plane magnetic field components.


title: Hydrogen tunneling in the perovskite ionic conductor BaCe(1-x)Y(x)O(3-d)

abstract:
  We present low-temperature anelastic and dielectric spectroscopy measurements
on the perovskite ionic conductor BaCe(1-x)Y(x)O(3-x/2) in the protonated,
deuterated and outgassed states. Three main relaxation processes are ascribed
to proton migration, reorientation about an Y dopant and tunneling around a
same O atom. An additional relaxation maximum appears only in the dielectric
spectrum around 60 K, and does not involve H motion, but may be of electronic
origin, e.g. small polaron hopping. The peak at the lowest temperature,
assigned to H tunneling, has been fitted with a relaxation rate presenting
crossovers from one-phonon transitions, nearly independent of temperature, to
two-phonon processes, varying as T^7, to Arrhenius-like. Substituting H with D
lowers the overall rate by 8 times. The corresponding peak in the dielectric
loss has an intensity nearly 40 times smaller than expected from the classical
reorientation of the electric dipole associated with the OH complex. This fact
is discussed in terms of coherent tunneling states of H in a cubic and
orthorhombically distorted lattice, possibly indicating that only H in the
symmetric regions of twin boundaries exhibit tunneling, and in terms of
reduction of the effective dipole due to lattice polarization.


title: Fermions and Emergent Noncommutative Gravity

abstract:
  Fermions coupled to Yang-Mills matrix models are studied from the point of
view of emergent gravity. We show that the simple matrix model action provides
an appropriate coupling for fermions to gravity, albeit with a non-standard
spin connection. Integrating out the fermions in a nontrivial geometrical
background induces indeed the Einstein-Hilbert action and a dilaton-like term,
at least for on-shell geometries. This explains and precisely reproduces the
UV/IR mixing for fermions in noncommutative gauge theory, extending recent
results for scalar fields. It also explains why some UV/IR mixing remains even
in supersymmetric models, except in the N=4 case.


title: Spin-Electric Coupling in Molecular Magnets

abstract:
  We study the triangular antiferromagnet Cu$_3$ in external electric fields,
using symmetry group arguments and a Hubbard model approach. We identify a
spin-electric coupling caused by an interplay between spin exchange, spin-orbit
interaction, and the chirality of the underlying spin texture of the molecular
magnet. This coupling allows for the electric control of the spin (qubit)
states, e.g. by using an STM tip or a microwave cavity. We propose an
experimental test for identifying molecular magnets exhibiting spin-electric
effects.


title: Particle Dynamics And Emergent Gravity

abstract:
  The emergent gravity proposal is examined within the framework of
noncommutative QED/gravity correspondence from particle dynamics point of view.


title: The viability of theories with matter coupled to the Ricci scalar

abstract:
  Recently there has been a proposal for modified gravitational f(R) actions
which include a direct coupling between the matter action and the Ricci scalar,
R. Of particular interest is the specific case where both the action and the
coupling are linear in R. It is shown that such an action leads to a theory of
gravity which includes higher order derivatives of the matter fields without
introducing more dynamics in the gravity sector and, therefore, cannot be a
viable theory for gravitation.


title: Essential dimension of Hermitian spaces

abstract:
  Given an hermitian space we compute its essential dimension, Chow motive and
prove its incompressibility in certain dimensions.


title:
Thermodynamics of Friedmann Equation and Masslike Function in General
  Braneworld

abstract:
  Using the generalized procedure proposed by \emph{Wu et al}\cite{wu}
recently, we construct the first law of thermodynamics on apparent horizon in a
general braneworld model with curvature correction terms on the brane and in
the bulk, respectively. The explicit entropy formulary of apparent horizon in
the general braneworld is worked out. We also discuss the masslike function
which associated with a new type first law of thermodynamics of the general
braneworld in detail. We analyze the difference between the conventional
thermodynamics and the new type thermodynamics on apparent horizon. At last,
the discussions about the physical meanings of the masslike function have also
been given.


title:
Strong coupling expansion for finite temperature Yang-Mills theory in
  the confined phase

abstract:
  We perform euclidean strong coupling expansions for Yang Mills theory on the
lattice at finite temperature. After setting up the formalism for general
SU(N), we compute the first few terms of the series for the free energy density
and the lowest screening mass in the case of SU(2). To next-to-leading order
the free energy series agrees with that of an ideal gas of glueballs. This
demonstrates that in the confined phase the quasi-particles indeed correspond
to the T=0 hadron excitations, as commonly assumed in hadron resonance gas
models. Our result also fixes the lower integration constant for Monte Carlo
calculations of the thermodynamic pressure via the integral method. In accord
with Monte Carlo results, we find screening masses to be nearly temperature
independent in the confined phase. This and the exponential smallness of the
pressure can be understood as genuine strong coupling effects. Finally, we
analyse Pade approximants to estimate the critical couplings of the phase
transition, which for our short series are only ~25% accurate. However, up to
these couplings the equation of state agrees quantitatively with numerical
results on N_t=1-4 lattices.


title: Collaborate, compete and share

abstract:
  We introduce and study a model of an interacting population of agents who
collaborate in groups which compete for limited resources. Groups are formed by
random matching agents and their worth is determined by the sum of the efforts
deployed by agents in group formation. Agents, on their side, have to share
their effort between contributing to their group's chances to outcompete other
groups and resource sharing among partners, when the group is successful. A
simple implementation of this strategic interaction gives rise to static and
evolutionary properties with a very rich phenomenology. A robust emerging
feature is the coexistence in the population of agents who invest mainly in the
success of their group and agents who concentrate in getting the largest share
of their group's profits.


title:
The period and amplitude changes of Polaris (alpha UMi) from 2003 to
  2007 measured with SMEI

abstract:
  We present an analysis of 4.5 years of high precision (0.1%) space-based
photometric measurements of the Cepheid variable Polaris, obtained by the broad
band Solar Mass Ejection Imager (SMEI) instrument on board the Coriolis
satellite. The data span from April 2003 to October 2007, with a cadence of 101
minutes and a fill factor of 70%. We have measured the mean peak to peak
amplitude across the whole set of observations to be 25 mmag. There is,
however, a clear trend that the size of the oscillations has been increasing
during the observations, with peak to peak variations less than 22 mmag in
early 2003, increasing to around 28 mmag by October 2007, suggesting that the
peak to peak amplitude is increasing at a rate of 1.39 \pm 0.12 mmag yr^{-1}.
Additionally, we have combined our new measurements with archival measurements
to measure a rate of period change of 4.90 \pm 0.26 s yr^{-1} over the last 50
years. However, there is some suggestion that the period of Polaris has
undergone a recent decline, and combined with the increased amplitude, this
could imply evolution away from an overtone pulsation mode into the fundamental
or a double pulsation mode depending on the precise mass of Polaris.


title: The Physics of Ghost Imaging

abstract:
  One of the most surprising consequences of quantum mechanics is the nonlocal
multi-particle interference observable in joint-detection of distant
particle-detectors. Ghost imaging is one of such phenomena. Two types of ghost
imaging have been experimentally demonstrated since 1995. Type-one ghost
imaging uses entangled photon pairs as the light source. The nonlocal
point-to-point image-forming correlation is the result of a
constructive-destructive superposition among a large number of biphoton
amplitudes, a nonclassical entity corresponding to different yet
indistinguishable alternative ways of producing a joint-detction event between
distant photodetectors. Type-two ghost imaging uses chaotic-thermal light. The
type-two image-forming correlation is the result of interferences between
paired two-photon amplitudes, corresponding to two different yet
indistinguishable alternative ways of triggering a join-detection event by two
independent photons. A great deal of confusion about ghost imaging comes from
"ghost shadow". Similar to x-ray photography, a ghost shadow can be made in
coincidences by "blocking-partial blocking-unblocking" of either co-rotating
laser beams or classically correlated "speckles". "Ghost shadow" is indeed a
classical phenomenon. The physics of ghost imaging, however, is fundamentally
different. This article is aimed at exploring the nonlocal two-photon
interference nature of ghost imaging.


title:
The Stellar Populations of Starburst Galaxies Through near infrared
  spectroscopy

abstract:
  We study the central (inner few hundred parsecs) stellar populations of four
starburst galaxies (NGC34, NGC1614, NGC3310 and NGC7714) in the near-infrared
(NIR), from 0.8 to 2.4microns, by fitting combinations of stellar population
models of various ages and metallicities. The NIR spectra of these galaxies
feature many absorption lines. For the first time, we fit simultaneously as
much as 15 absorption features in the NIR. The observed spectra are best
explained by stellar populations containing a sizable amount (20 to 56 % by
mass) of ~1Gyr old stellar population with Thermally Pulsing-Asymptotic Giant
Branch stars. We found that the metallicity of the stars which dominates the
light is solar. Metallicities substantially different from solar give a worse
fit. Though the ages and metallicities we estimate using the NIR spectroscopy
are in agreement with values from the literature based on the UV/optical, we
find older ages and a larger age spread. This may be due to the fact that the
optical is mostly sensitive to the last episode of star formation, while the
NIR better maintains the record of previous stellar generations. Another
interesting result is that the reddening estimated from the whole NIR spectrum
is considerably lower than that based on emission lines. Finally, we find a
good agreement of the free emission line spectrum with photoionization models,
using as input spectral energy distribution the synthetic composite template we
derived as best-fit.


title: Note on 2-rational fields

abstract:
  We compute the Galois group of the maximal 2-ramified and complexified
pro-2-extension of any 2-rational number field.


title: Geometric Approach to Pontryagin's Maximum Principle

abstract:
  Since the second half of the 20th century, Pontryagin's Maximum Principle has
been widely discussed and used as a method to solve optimal control problems in
medicine, robotics, finance, engineering, astronomy. Here, we focus on the
proof and on the understanding of this Principle, using as much geometric ideas
and geometric tools as possible. This approach provides a better and clearer
understanding of the Principle and, in particular, of the role of the abnormal
extremals. These extremals are interesting because they do not depend on the
cost function, but only on the control system. Moreover, they were discarded as
solutions until the nineties, when examples of strict abnormal optimal curves
were found. In order to give a detailed exposition of the proof, the paper is
mostly self\textendash{}contained, which forces us to consider different areas
in mathematics such as algebra, analysis, geometry.


title:
Path integral formulation of fractional Brownian motion for general
  Hurst exponent

abstract:
  In J. Phys. A: Math. Gen. 28, 4305 (1995), K. L. Sebastian gave a path
integral computation of the propagator of subdiffusive fractional Brownian
motion (fBm), i.e. fBm with a Hurst or self-similarity exponent $H\in(0,1/2)$.
The extension of Sebastian's calculation to superdiffusion, $H\in(1/2,1]$,
becomes however quite involved due to the appearance of additional boundary
conditions on fractional derivatives of the path. In this paper, we address the
construction of the path integral representation in a different fashion, which
allows to treat both subdiffusion and superdiffusion on an equal footing. The
derivation of the propagator of fBm for general Hurst exponent is then
performed in a neat and unified way.


title: Racetrack Inflation and Cosmic Strings

abstract:
  We consider the coupling of racetrack inflation to matter fields as realised
in the D3/D7 brane system. In particular, we investigate the possibility of
cosmic string formation in this system. We find that string formation before or
at the onset of racetrack inflation is possible, but they are then inflated
away. Furthermore, string formation at the end of inflation is prevented by the
presence of the moduli sector. As a consequence, no strings survive racetrack
inflation.