title:
Polynomial hierarchy, Betti numbers and a real analogue of Toda's
  theorem

abstract:
  Toda proved in 1989 that the (discrete) polynomial time hierarchy,
$\mathbf{PH}$, is contained in the class $\mathbf{P}^{#\mathbf{P}}$, namely the
class of languages that can be decided by a Turing machine in polynomial time
given access to an oracle with the power to compute a function in the counting
complexity class $#\mathbf{P}$. This result which illustrates the power of
counting is considered to be a seminal result in computational complexity
theory. An analogous result in the complexity theory over the reals (in the
sense of Blum-Shub-Smale real machines) has been missing so far. In this paper
we formulate and prove a real analogue of Toda's theorem. Unlike Toda's proof
in the discrete case, which relied on sophisticated combinatorial arguments,
our proof is topological in nature. As a consequence of our techniques we are
also able to relate the computational hardness of two extremely well-studied
problems in algorithmic semi-algebraic geometry -- namely the problem of
deciding sentences in the first order theory of the reals with a constant
number of quantifier alternations, and that of computing Betti numbers of
semi-algebraic sets. We obtain a polynomial time reduction of the compact
version of the first problem to the second. This latter result might be of
independent interest to researchers in algorithmic semi-algebraic geometry.


title:
Evolution of the dynamical pairing across the phase diagram of a
  strongly correlated high-temperature superconductor

abstract:
  We study the dynamics of the Cooper pairing across the T=0 phase diagram of
the two-dimensional Hubbard Model, relevant for high-temperature
superconductors, using a cluster extension of dynamical mean field theory. We
find that the superconducting pairing function evolves from an unconventional
form in the over-doped region into a more conventional boson-mediated retarded
form in the under-doped region of the phase diagram. The boson, however,
promotes the rise of a pseudo-gap in the electron density of states rather than
a superconducting gap as in the standard theory of superconductivity. We
discuss our results in terms of Mott-related phenomena, and we show that they
can be observed in tunneling experiments.


title:
Superallowed 0+ to 0+ nuclear beta decays: A new survey with precision
  tests of the conserved vector current hypothesis and the standard model

abstract:
  A new critical survey is presented of all half-life, decay-energy and
branching-ratio measurements related to 20 0+ to 0+ beta decays. Compared with
our last review, there are numerous improvements: First, we have added 27
recently published measurements and eliminated 9 references; of particular
importance, the new data include a number of high-precision Penning-trap
measurements of decay energies. Second, we have used the recently improved
isospin symmetry-breaking corrections. Third, our calculation of the
statistical rate function now accounts for possible excitation in the daughter
atom. Finally, we have re-examined the systematic uncertainty associated with
the isospin symmetry-breaking corrections by evaluating the radial-overlap
correction using Hartree-Fock radial wave functions and comparing the results
with our earlier calculations, which used Saxon-Woods wave functions; the
provision for systematic uncertainty has been changed as a consequence. The new
corrected Ft values are impressively constant and their average, when combined
with the muon liftime, yields the up-down quark-mixing element of the
Cabibbo-Kobayashi-Maskawa (CKM) matrix, V_{ud} = 0.97425(22). The unitarity
test on the top row of the matrix becomes |V_{ud}|^2 + |V_{us}|^2 + |V_{ub}|^2
= 0.99995(61). Both V_{ud} and the unitarity sum have significantly reduced
uncertainties compared with our previous survey, although the new value of
V_{ud} is statistically consistent with the old one. From these data we also
set limits on the possible existence of scalar interactions, right-hand
currents and extra Z bosons. Finally, we discuss the priorities for future
theoretical and experimental work with the goal of making the CKM unitarity
test even more definitive.


title:
An Efficient Adaptive Distributed Space-Time Coding Scheme for
  Cooperative Relaying

abstract:
  A non-regenerative dual-hop wireless system based on a distributed space-time
coding strategy is considered. It is assumed that each relay retransmits an
appropriately scaled space-time coded version of its received signal. The main
goal of this paper is to investigate a power allocation strategy in relay
stations, which is based on minimizing the outage probability. In the high
signal-to-noise ratio regime for the relay-destination link, it is shown that a
threshold-based power allocation scheme (i.e., the relay remains silent if its
channel gain with the source is less than a prespecified threshold) is optimum.
Monte-Carlo simulations show that the derived on-off power allocation scheme
performs close to optimum for finite signal-to-noise ratio values. Numerical
results demonstrate a dramatic improvement in system performance as compared to
the case that the relay stations forward their received signals with full
power. In addition, a hybrid amplify-and-forward/detect-and-forward scheme is
proposed for the case that the quality of the source-relay link is good.
Finally, the robustness of the proposed scheme in the presence of channel
estimation errors is numerically evaluated.


title: Phase-diffusion dynamics in weakly coupled Bose-Einstein condensates

abstract:
  We study the phase-sensitivity of collisional phase-diffusion between weakly
coupled Bose-Einstein condensates, using a semiclassical picture of the
two-mode Bose-Hubbard model. When weak-coupling is allowed, zero relative phase
locking is attained in the Josephson-Fock transition regime, whereas a $\pi$
relative phase is only locked in Rabi-Josephson point. Our analytic
semiclassical estimates agree well with the numerical results.


title: Dark torsion as the cosmic speed-up

abstract:
  It is shown that the recently detected acceleration of the universe can be
understood by considering a modification of the teleparallel equivalent of
General Relativity (TEGR), with no need of dark energy. The solution also
exhibits phases dominated by matter and radiation as expected in the standard
cosmological evolution. We perform a joint analysis with measurements of the
most recent type Ia supernovae (SNe Ia), Baryon Acoustic Oscillation (BAO) peak
and estimates of the CMB shift parameter data to constraint the only new
parameter this theory has.


title:
Search for double beta decay with HPGe detectors at the Gran Sasso
  underground laboratory

abstract:
  Neutrinoless double-beta decay is practically the only way to establish the
Majorana nature of the neutrino mass and its decay rate provides a probe of an
effective neutrino mass. Double beta experiments are long-running underground
experiments with specific challenges concerning the background reduction and
the long term stability. These problems are addressed in this work for the
Heidelberg-Moscow (HdM), GENIUS Test Facility (TF) and GERDA experiments. The
HdM experiment collected data with enriched 76Ge high purity (HPGe) detectors
from 1990 to 2003. An improved analysis of HdM data is presented, exploiting
new calibration and spectral shape measurements with the HdM detectors.
GENIUS-TF was a test-facility that verified the feasibility of using bare
germanium detectors in liquid nitrogen. The first year results of this
experiment are discussed. The GERDA experiment has been designed to further
increase the sensitivity by operating bare germanium detectors in a high purity
cryogenic liquid, which simultaneously serves as a shielding against background
and as a cooling media. In the preparatory stage of GERDA, an external
background gamma flux measurement was done at the experimental site in the Hall
A of the Gran Sasso laboratory. The characterization of the enriched detectors
from the HdM and IGEX experiments was performed in the underground detector
laboratory for the GERDA collaboration. Long term stability measurements of a
bare HPGe detector in liquid argon were carried out. Based on these
measurements, the first lower limit on the half-life of neutrinoless double
electron capture of 36Ar was established to be 1.85*10^18 years at 68% C.L.


title: Analysis of multi-configuration Kohn-Sham methods

abstract:
  We consider the extension of the standard single-determinant Kohn-Sham method
to the case of a multiconfiguration trial wavefunction. By applying the
rigorous Kohn-Sham method to this case, we construct the proper interacting and
non-interacting energy functionals. Following the Hohenberg-Kohn theorem for
both energy functionals, we derive the corre-sponding multiconfiguration
Kohn-Sham equations. At the end of the analysis we show that, at the ground
state, the multiconfiguration wavefunction must collapse into a
single-determinant wavefunction, equal to the regular KS wavefunction. We also
discuss the non-collapse of the wavefunction in other multiconfiguration
density functional theory methods where the auxiliary system is partially
interacting.


title: Homology representations arising from the half cube, II

abstract:
  In a previous work (arXiv:0806.1503v2), we defined a family of subcomplexes
of the $n$-dimensional half cube by removing the interiors of all half cube
shaped faces of dimension at least $k$, and we proved that the homology of such
a subcomplex is concentrated in degree $k-1$. This homology group supports a
natural action of the Coxeter group $W(D_n)$ of type $D$. In this paper, we
explicitly determine the characters (over ${\Bbb C}$) of these homology
representations, which turn out to be multiplicity free. Regarded as
representations of the symmetric group $S_n$ by restriction, the homology
representations turn out to be direct sums of certain representations induced
from parabolic subgroups. The latter representations of $\sym_n$ agree (over
${\Bbb C}$) with the representations of $\sym_n$ on the $(k-2)$-nd homology of
the complement of the $k$-equal real hyperplane arrangement.


title:
Transient dynamics and momentum redistribution in cold atoms via
  recoil-induced resonances

abstract:
  We use an optically dense, anisotropic magneto-optical trap to study
recoil-induced resonances (RIRs) in the transient, high-gain regime. We find
that two distinct mechanisms govern the atomic dynamics: the finite,
frequency-dependent atomic response time, and momentum-space population
redistribution. At low input probe intensities, the residual Doppler width of
the atoms, combined with the finite atomic response time, result in a linear,
transient hysteretic effect that modifies the locations, widths, and magnitudes
of the resulting gain spectra depending on the sign of the scan chirp. When
larger intensities (\textit{i.e.}, greater than a few $\mu$W/cm$^2$) are
incident on the atomic sample for several $\mu$s, hole-burning in the atomic
sample's momentum distribution leads to a coherent population redistribution
that persists for approximately 100 $\mu$s. We propose using RIRs to engineer
the atomic momentum distribution to enhance the nonlinear atom-photon coupling.
We present a numerical model, and compare the calculated and experimental
results to verify our interpretation.


title:
Alternative Data Reduction Procedures for UVES: Wavelength Calibration
  and Spectrum Addition

abstract:
  This paper addresses alternative procedures to the ESO supplied pipeline
procedures for the reduction of UVES spectra of two quasar spectra to determine
the value of the fundamental constant mu = Mp/Me at early times in the
universe. The procedures utilize intermediate product images and spectra
produced by the pipeline with alternative wavelength calibration and spectrum
addition methods. Spectroscopic studies that require extreme wavelength
precision need customized wavelength calibration procedures beyond that usually
supplied by the standard data reduction pipelines. An example of such studies
is the measurement of the values of the fundamental constants at early times in
the universe. This article describes a wavelength calibration procedure for the
UV-Visual Echelle Spectrometer on the Very Large Telescope, however, it can be
extended to other spectrometers as well. The procedure described here provides
relative wavelength precision of better than 3E-7 for the long-slit
Thorium-Argon calibration lamp exposures. The gain in precision over the
pipeline wavelength calibration is almost entirely due to a more exclusive
selection of Th/Ar calibration lines.


title: A Global Algebraic Treatment for XY2 Molecules : Application to D2S

abstract:
  We suggest to use for $XY_2$ molecules some results previously established in
a series of articles for vibrational modes and electronic states with an $E$
symmetry type. We first summarize the formalism for the standard $u(2)\supset
su(2)\supset so(2)$ chain which, for its most part, can be kept for the study
of both stretching and bending modes of $XY_2$ molecules. Next the also
standard chain $u(3)\supset u(2) \supset su(2) \supset so(2)$ which is
necessary, within the considered approach, is introduced for the stretching
modes. All operators acting within the irreducible representation
(\textit{irrep}) $[N00]\equiv [N\dot{0}]$ of $u(3)$ are built and their matrix
elements computed within the standard basis. All stretch-bend interaction
operators taking into account the polyad structure associated with a resonance
$\omega_1\approx \omega_3 \approx 2 \omega_2$ are obtained. As an illustration,
an application to the $D_2S$ molecular system is considered, especially the
symmetrization in $C_{2v}$. It is shown that our unitary formalism allows to
reproduce in an extremely satisfactory way all the experimental data up to the
dissociation limit.


title: Exotic baryon resonances in the Skyrme model

abstract:
  We outline how one can understand the Skyrme model from the modern
perspective. We review the quantization of the SU(3) rotations of the Skyrmion,
leading to the exotic baryons that cannot be made of three quarks. It is shown
that in the limit of large number of colours the lowest-mass exotic baryons can
be studied from the kaon-Skyrmion scattering amplitudes, an approach known
after Callan and Klebanov. We follow this approach and find, both analytically
and numerically, a strong Theta+ resonance in the scattering amplitude that is
traced to the rotational mode. The Skyrme model does predict an exotic
resonance Theta+ but grossly overestimates the width. To understand better the
factors affecting the width, it is computed by several methods giving, however,
identical results. In particular, we show that insofar as the width is small,
it can be found from the transition axial constant. The physics leading to a
narrow Theta+ resonance is briefly reviewed and affirmed.


title: Selfduality and Chern-Simons Theory

abstract:
  We propose a relation between the operator of S-duality (of N=4 super
Yang-Mills theory in 3+1D) and a topological theory in one dimension lower. We
construct the topological theory by compactifying N=4 super Yang-Mills on a
circle with an S-duality and R-symmetry twist. The S-duality twist requires a
selfdual coupling constant. We argue that for a sufficiently low rank of the
gauge group the three-dimensional low-energy description is a topological
theory, which we conjecture to be a pure Chern-Simons theory. This conjecture
implies a connection between the action of mirror symmetry on the sigma-model
with Hitchin's moduli space as target space and geometric quantization of the
moduli space of flat connections on a Riemann surface.


title:
Evidence for strongly coupled charge-density-wave ordering in
  three-dimensional RE5Ir4Si10 compounds by optical measurements

abstract:
  We report optical spectra of Lu$_5$Ir$_4$Si$_{10}$ and Er$_5$Ir$_4$Si$_{10}$,
exhibiting the phenomenon of coexisting superconductivity or antiferromagnetism
and charge density wave (CDW) order. We measure the maximum value of the charge
density wave gap present on part of the Fermi surface of Lu5Ir4Si10,
corresponding to a ratio 2\Delta/k_B T_CDW \approx 10, well above the value in
the limit of weak electron-phonon coupling. Strong electron-phonon coupling was
confirmed by analyzing the optical conductivity with the Holstein model
describing the electron-phonon interactions, indicating the coupling to phonons
centered at 30 meV, with a coupling constant \lambda \approx 2.6. Finally we
provide evidence that approximately 16 % of the Fermi surface of Lu5Ir4Si10
becomes gapped in the CDW state.


title:
Electronic and lattice dynamical properties of the iron-based
  superconductors LiFeAs and NaFeAs

abstract:
  The electronic structure and lattice vibrational frequencies of the newly
discovered superconductors, LiFeAs and NaFeAs, are calculated within density
functional theory. We show that in the vicinity of the Fermi energy, the
density of states is dominated by contributions from Fe 3d states. We also
calculate the electron-phonon coupling strength and show that it is too weak to
account for the observed values of the superconducting transition temperatures.
This seems to indicate that the iron-based superconductors are not of the
conventional type.


title: Massive Black Hole Recoil in High Resolution Hosts

abstract:
  The final inspiral and coalescence of a black hole binary can produce highly
beamed gravitational wave radiation. To conserve linear momentum, the black
hole remnant can recoil with "kick" velocity as high as 4000 km/s. We present
two sets of full N-body simulations of recoiling massive black holes (MBH) in
high-resolution, non-axisymmetric potentials. The host to the first set of
simulations is the main halo of the Via Lactea I simulation (Diemand et al.
2007). The nature of the resulting orbits is investigated through a numerical
model where orbits are integrated assuming an evolving, triaxial NFW potential,
and dynamical friction is calculated directly from the velocity dispersion
along the major axes of the main halo of Via Lactea I. By comparing the
triaxial case to a spherical model, we find that the wandering time spent by
the MBH is significantly increased due to the asphericity of the halo. For
kicks larger than 200 km/s, the remnant MBH does not return to the inner 200 pc
within 1 Gyr, a timescale an order of magnitude larger than the upper limit of
the estimated QSO lifetime. The second set of simulations is run using the
outcome of a high-resolution gas-rich merger (Mayer et al. 2007) as host
potential. In this case, a recoil velocity of 500 km/s cannot remove the MBH
from the nuclear region.


title:
Late time observations of GRB080319B: jet break, host galaxy and
  accompanying supernova

abstract:
  The Swift discovered GRB080319B was by far the most distant source ever
observed at naked eye brightness, reaching a peak apparent magnitude of 5.3 at
a redshift of z=0.937. We present our late-time optical (HST, Gemini & VLT) and
X-ray (Chandra) observations, which confirm that an achromatic break occurred
in the power-law afterglow light curve at ~11 days post-burst. This most likely
indicates that the gamma-ray burst (GRB) outflow was collimated, which for a
uniform jet would imply a total energy in the jet E_{jet} \gsim 10^{52} erg.
Our observations also show a late-time excess of red light, which is well
explained if the GRB was accompanied by a supernova (SN), similar to those seen
in some other long-duration GRBs. The latest observations are dominated by
light from the host and show that the GRB took place in a faint dwarf galaxy
(r(AB)\approx27.0, rest-frame M_B\approx-17.2). This galaxy is small even by
the standards of other GRB hosts, which is suggestive of a low metallicity
environment. Intriguingly, the properties of this extreme event - a small host
and bright supernova - are entirely typical of the very low-luminosity bursts
such as GRB980425 and GRB060218.


title:
The Impact of New Technologies in Public Financial Management and
  Performance: Agenda for Public Financial Management Reformance in the Context
  of Global Best Practices

abstract:
  Information and Communication Technologies (ICT) has practically penetrated
into all spheres of life. Therefore a closer look at the impact of ICT in
public financial management and performance is highly justified. Public finance
is defined as a field of economics concerned with paying for collective or
governmental activities, and with the administration and design of those
activities. Activities will be viewed as services or more precisely as public
services. We believe that there is need to consider performance from the
perspective of effective performance and the perceived performance. In fact the
real or effective performance might not correspond to the perceived
performance. A service can be considered from the perspective of the
decision-maker, who in our case could be a government or a collectivity. ICT
can be employed in the three phases that concern the decision-maker: design,
implementation and evaluation. The beneficiaries of a service can employ ICT in
any of the three phases - awareness, exploitation and assessment - for
guarantying a high level of efficiency. Each phase in the environment of a
service will be presented as well as illustrations of how ICT can be employed
in order to improve the end-result of each one of them. We believe that a high
efficiency of each phase will produce a high global efficiency. It should be
noted however that the effectiveness of any system is highly dependent on the
human engagement in the system. Therefore, the impact of ICT in public
financial management will be felt only if the decision-makers and the end-users
of the services engage themselves in the success of the system. Instead of
giving a catalog of services, the focus has been on the model (or methodology)
to adopt in designing services for which ICT could enhance the implementation.


title: Mixed type multiple orthogonal polynomials for two Nikishin systems

abstract:
  We study the logarithmic and ratio asymptotic of linear forms constructed
from a Nikishin system which satisfy orthogonality conditions with respect to a
system of measures generated from another Nikishin system. This construction
combines type I and type II multiple orthogonal polynomials. The logarithmic
asymptotic of the linear forms is expressed in terms of the extremal solution
of an associated vector valued equilibrium problem for the logarithmic
potential. The ratio asymptotic is described by means of a conformal
representation of an appropriate Riemann surface of genus zero onto the
extended complex plane.


title: A First Look at Rotation in Inactive Late-Type M Dwarfs

abstract:
  We have examined the relationship between rotation and activity in 14
late-type (M6-M7) M dwarfs, using high resolution spectra taken at the W.M.
Keck Observatory and flux-calibrated spectra from the Sloan Digital Sky Survey.
Most were selected to be inactive at a spectral type where strong H-alpha
emission is quite common. We used the cross-correlation technique to quantify
the rotational broadening; six of the stars in our sample have vsini > 3.5
km/s. Our most significant and perplexing result is that three of these stars
do not exhibit H-alpha emission, despite rotating at velocities where previous
work has observed strong levels of magnetic field and stellar activity. Our
results suggest that rotation and activity in late-type M dwarfs may not always
be linked, and open several additional possibilities including a
rotationally-dependent activity threshold, or a possible dependence on stellar
parameters of the Rossby number at which magnetic/activity "saturation" takes
place in fully convective stars.


title: Chi Values for Blue Emission Lines in M Dwarfs

abstract:
  We compute chi values for blue emission lines in active M dwarfs. Using
flux-calibrated spectra from nearby M dwarfs and spectral M dwarf templates
from SDSS, we derive analytic relations that describe how the chi values for
the CaII H and K as well as the H-beta, H-gamma, H-delta, H-epsilon and H8
Balmer emission lines vary as a function of spectral type and color. The chi
values are useful for numerous M dwarf studies where the intrinsic luminosity
of emission lines cannot be estimated due to uncertain distances and/or
non-flux-calibrated spectra. We use these results to estimate the mean
properties of blue emission lines in active field M dwarfs from SDSS.


title:
B\"acklund Transformations and the Atiyah-Ward ansatz for Noncommutative
  Anti-Self-Dual Yang-Mills Equations

abstract:
  We present Backlund transformations for the noncommutative anti-self-dual
Yang-Mills equation where the gauge group is G=GL(2) and use it to generate a
series of exact solutions from a simple seed solution. The solutions generated
by this approach are represented in terms of quasideterminants. We also explain
the origins of all of the ingredients of the Backlund transformations within
the framework of noncommutative twistor theory. In particular we show that the
generated solutions belong to a noncommutative version of the Atiyah-Ward
ansatz.


title:
Using Magnetic Activity and Galactic Dynamics to Constrain the Ages of M
  Dwarfs

abstract:
  We present a study of the dynamics and magnetic activity of M dwarfs using
the largest spectroscopic sample of low-mass stars ever assembled. The age at
which strong surface magnetic activity (as traced by H-alpha) ceases in M
dwarfs has been inferred to have a strong dependence on mass (spectral type,
surface temperature) and explains previous results showing a large increase in
the fraction of active stars at later spectral types. Using spectral
observations of more than 40000 M dwarfs from the Sloan Digital Sky Survey, we
show that the fraction of active stars decreases as a function of vertical
distance from the Galactic plane (a statistical proxy for age), and that the
magnitude of this decrease changes significantly for different M spectral
types. Adopting a simple dynamical model for thin disk vertical heating, we
assign an age for the activity decline at each spectral type, and thus
determine the activity lifetimes for M dwarfs. In addition, we derive a
statistical age-activity relation for each spectral type using the dynamical
model, the vertical distance from the Plane and the H-alpha emission line
luminosity of each star (the latter of which also decreases with vertical
height above the Galactic plane).


title:
Feast and Famine: Regulation of Black Hole Growth in Low Redshift
  Galaxies

abstract:
  We analyze the observed distribution of Eddington ratios as a function of
supermassive black hole mass for a large sample of nearby galaxies drawn from
the Sloan Digital Sky Survey. We demonstrate that there are two distinct
regimes of black hole growth in nearby galaxies. The first is associated with
galaxies with significant star formation in their central kiloparsec regions,
and is characterized by a broad log-normal distribution of accretion rates
peaked at about one percent of the Eddington limit. In this regime, the
Eddington ratio distribution is independent of the mass of the black hole and
shows no further dependence on the central stellar population of the galaxy.
The second regime is associated with galaxies with old central stellar
populations, and is characterized by a power-law distribution function of
Eddington ratios. In this regime, the time-averaged mass accretion rate onto
black holes is proportional to the mass of stars in the galaxy bulge, with a
constant of proportionality that depends on the mean stellar age of the stars.
This result is once again independent of black hole mass. We show that both the
slope of the power-law and the decrease in the accretion rate onto black holes
in old galaxies are consistent with population synthesis model predictions of
the decline in stellar mass loss rates as a function of mean stellar age. Our
results lead to a very simple picture of black hole growth in the local
Universe. If the supply of cold gas in a galaxy bulge is plentiful, the black
hole regulates its own growth at a rate that does not further depend on the
properties of the interstellar medium. Once the gas runs out, black hole growth
is regulated by the rate at which evolved stars lose their mass.


title: The impact of TP-AGB stars on hierarchical galaxy formation models

abstract:
  The spectro-photometric properties of galaxies in galaxy formation models are
obtained by combining the predicted history of star formation and mass
accretion with the physics of stellar evolution through stellar population
models. In the recent literature, significant differences have emerged
regarding the implementation of the Thermally-Pulsing Asymptotic Giant Branch
phase of stellar evolution. The emission in the TP-AGB phase dominates the
bolometric and near-IR spectrum of intermediate-age (~1 Gyr) stellar
populations, hence it is crucial for the correct modeling of the galaxy
luminosities and colours. In this paper for the first time, we incorporate a
full prescription of the TP-AGB phase in a semi-analytic model of galaxy
formation. We find that the inclusion of the TP-AGB in the model spectra
dramatically alters the predicted colour-magnitude relation and its evolution
with redshift. When the TP-AGB phase is active, the rest-frame V-K galaxy
colours are redder by almost 2 magnitudes in the redshift range z~2-3 and by 1
magnitude at z~1. Very red colours are produced in disk galaxies, so that the
V-K colour distributions of disk and spheroids are virtually undistinguishable
at low redshifts. We also find that the galaxy K-band emission is more than 1
magnitude higher in the range z~1-3. This may alleviate the difficulties met by
the hierarchical clustering scenario in predicting the red galaxy population at
high redshifts. The comparison between simulations and observations have to be
revisited in the light of our results.


title:
The Chandra survey of the SMC "Bar": II. Optical counterparts of X-ray
  sources

abstract:
  We present the most likely optical counterparts of 113 X-ray sources detected
in our Chandra survey of the central region of the Small Magellanic Cloud (SMC)
based on the OGLE-II and MCPS catalogs. We estimate that the foreground
contamination and chance coincidence probability are minimal for the bright
optical counterparts (corresponding to OB type stars; 35 in total). We propose
here for the first time 13 High-Mass X-ray Binaries (HMXBs), of which 4 are
Be/X-ray binaries (Be-XRBs), and we confirm the previous classification of 18
Be-XRBs. We estimate that the new candidate Be-XRBs have an age of 15-85 Myr,
consistent with the age of Be stars. We also examine the "overabundance" of
Be-XRBs in the SMC fields covered by Chandra, in comparison with the Galaxy. In
luminosities down to about 10^{34} erg/s, we find that SMC Be-XRBs are 1.5
times more common when compared to the Milky Way even after taking into account
the difference in the formation rates of OB stars. This residual excess can be
attributed to the lower metallicity of the SMC. Finally, we find that the
mixing of Be-XRBs with other than their natal stellar population is not an
issue in our comparisons of Be-XRBs and stellar populations in the SMC.
Instead, we find indication for variation of the SMC XRB populations on
kiloparsec scales, related to local variations of the formation rate of OB
stars and slight variation of their age, which results in different relative
numbers of Be stars and therefore XRBs.


title: Observing the r-Process Signature in the Oldest Stars

abstract:
  The abundance patterns of metal-poor stars provide us a wealth of chemical
information about various stages of the chemical evolution of the Galaxy. In
particular, these stars allow us to study the formation and evolution of the
elements and the involved nucleosynthesis processes. Metal-poor stars are the
local equivalent of the high-redshift Universe, and thus offer crucial
observational constraints on a variety of issues regarding the early Universe.
This review presents an introduction to metal-poor stars and their role as
"cosmic lab" for the study of neutron-capture nucleosynthesis processes,
particularly that of the r-process. The metal-poor star HE 1523-0901 serves as
an example for this group of objects. It displays in its spectrum the strongest
overabundance of neutron-capture elements associated with the r-process. Heavy
neutron-capture elements such as Eu, Os, and Ir were measured, as well as the
radioactive elements Th and U. Abundance of Th and U, in conjunction with those
of stable elements make possible nucleo-chronomtery, i.e., the determination of
stellar ages. HE 1523-0901 appears to be ~13 Gyr old. Age uncertaintites range
from 2-5 Gyr for individual chronometers, and are largly due to theoretical
uncertainties in the initial production ratio of the employed chronometers. The
decay product of the radioactive elements, lead, can be used to constrain
r-process calculations. Only few such stars are currently known with detected
U. These objects, however, are crucial for the study of this nucleosynthesis
process.


title: Pairing dynamics in strongly correlated superconductivity

abstract:
  Confirmation of the phononic origin of Cooper pair formation in
superconductors came with the demonstration that the interaction was retarded
and that the corresponding energy scales were associated with phonons. Using
cellular dynamical mean-field theory for the two-dimensional Hubbard model, we
identify such retardation effects in d-wave pairing and associate the
corresponding energy scales with short-range spin fluctuations. We find which
frequencies are relevant for pairing as a function of interaction strength and
doping and show that the disappearance of superconductivity on the overdoped
side coincides with the disappearance of the low energy feature in the
antiferromagnetic fluctuations, as observed in neutron scattering experiments.


title: SUSY Without Prejudice at Linear Colliders

abstract:
  We explore the physics of the general CP-conserving MSSM with Minimal Flavor
Violation, the pMSSM. The 19 soft SUSY breaking parameters are chosen so to
satisfy all existing experimental and theoretical constraints assuming that the
WIMP is the lightest neutralino. We scan this parameter space twice using both
flat and log priors and compare the results which yield similar conclusions.
Constraints from both LEP and the Tevatron play an important role in obtaining
our final model samples. Implications for future TeV-scale $e^+e^-$ linear
colliders(LC) are discussed.


title: Towards a non-abelian electric-magnetic symmetry: the skeleton group

abstract:
  We propose an electric-magnetic symmetry group in non-abelian gauge theory,
which we call the skeleton group. We work in the context of non-abelian
unbroken gauge symmetry, and provide evidence for our proposal by relating the
representation theory of the skeleton group to the labelling and fusion rules
of charge sectors. We show that the labels of electric, magnetic and dyonic
sectors in non-abelian Yang-Mills theory can be interpreted in terms of
irreducible representations of the skeleton group. Decomposing tensor products
of these representations thus gives a set of fusion rules which contain
information about the full fusion rules of these charge sectors. We demonstrate
consistency of the skeleton's fusion rules with the known fusion rules of the
purely electric and purely magnetic magnetic sectors, and extract new
predictions for the fusion rules of dyonic sectors in particular cases. We also
implement S-duality and show that the fusion rules obtained from the skeleton
group commute with S-duality.


title:
Instability of the ACW model, and problems with massive vectors during
  inflation

abstract:
  We prove that the anisotropic inflationary background of the
Ackerman-Carroll-Wise model, characterized by a fixed-norm vector field, is
unstable. We found the instability by explicitly solving the linearized
equations for the most general set of perturbations around this background, and
by noticing that the solutions diverge close to horizon crossing. This happens
because one perturbation becomes a ghost at that moment. A simplified
computation, with only the perturbations of the vector field included, shows
the same instability, clarifying the origin of the problem. We then discuss
several other models, with a particular emphasis on the case of a nonminimal
coupling to the curvature, in which vector fields are used either to support an
anisotropic expansion, or to generate cosmological perturbations on an
isotropic background. In many cases, the mass term of the vector needs to have
the ``wrong'' sign; we show that, as a consequence, the longitudinal vector
mode is a ghost (a field with negative kinetic term, and negative energy; not
simply a tachyon). We comment on problems that arise at the quantum level. In
particular, the presence of a ghost can be a serious difficulty for the UV
completion that such models require in the sub-horizon regime.


title:
Petrov D vacuum spaces revisited: Identities and Invariant
  Classification

abstract:
  For Petrov D vacuum spaces, two simple identities are rederived and some new
identities are obtained, in a manageable form, by a systematic and transparent
analysis using the GHP formalism. This gives a complete involutive set of
tables for the four GHP derivatives on each of the four GHP spin coefficients
and the one Weyl tensor component. It follows directly from these results that
the theoretical upper bound on the order of covariant differentiation of the
Riemann tensor required for a Karlhede classification of these spaces is
reduced to two.


title:
Ultracold molecules from ultracold atoms: a case study with the KRb
  molecule

abstract:
  Ultracold collisions of cold atoms or molecules make the bound states of the
collision complex formed from the two colliding species accessible for control
and manipulation of the cold species or the complex. Such resonances are best
treated by a resonant scattering theory, which in the ultracold domain can take
advantage of the properties of the long-range potential and the methods of
multichannel quantum defect theory. Coupled channels calculations on the
threshold scattering states and bound states of the 40K87Rb molecule illustrate
the ideas and methodology of quantum defect theory using the long-range
potential and also demonstrate the spin properties of the bound states
throughout the spectrum.


title: Jamming in Systems Composed of Frictionless Ellipse-Shaped Particles

abstract:
  We study the structural and mechanical properties of jammed ellipse packings,
and find that the nature of the jamming transition in these systems is
fundamentally different from that for spherical particles. Ellipse packings are
generically hypostatic with more degrees of freedom than constraints. The
spectra of low energy excitations possess two gaps and three distinct branches
over a range of aspect ratios. In the zero compression limit, the energy of the
modes in the lowest branch increases {\it quartically} with deformation
amplitude, and the density of states possesses a $\delta$-function at zero
frequency. We identify scaling relations that collapse the low-frequency part
of the spectra for different aspect ratios. Finally, we find that the degree of
hypostaticity is determined by the number of quartic modes of the packing.


title:
Heavy baryon mass spectrum from lattice QCD with 2+1 dynamical sea quark
  flavors

abstract:
  We investigate the mass differences of charm and bottom heavy baryons, using
MILC lattice gauge configurations with 2+1 dynamical sea quark flavors. We
extend our previous work to three lattice spacings: fine (a~0.09), coarse
(a~0.12), and medium-coarse (a~0.15) ensembles. For extrapolations and
interpolations, we apply simultaneous quadratic fits and simple linear fits
with the full QCD data points for the valence quark masses as well as the sea
quark masses.


title: Hadronic interactions and nuclear physics

abstract:
  I give an overview of efforts in the last year to calculate interactions
among hadrons using lattice QCD. Results discussed include the extraction of
low-energy phase shifts and three-body interactions, and the study of pion and
kaon condensation. A critical appraisal is offered of recent attempts to
calculate nucleon-nucleon and nucleon-hyperon potentials on the lattice.


title: A novel changepoint detection algorithm

abstract:
  We propose an algorithm for simultaneously detecting and locating
changepoints in a time series, and a framework for predicting the distribution
of the next point in the series. The kernel of the algorithm is a system of
equations that computes, for each index i, the probability that the last (most
recent) change point occurred at i. We evaluate this algorithm by applying it
to the change point detection problem and comparing it to the generalized
likelihood ratio (GLR) algorithm. We find that our algorithm is as good as GLR,
or better, over a wide range of scenarios, and that the advantage increases as
the signal-to-noise ratio decreases.


title: Polaronic hole-trapping in doped $\rm BaBiO_3$

abstract:
  The present {\em ab initio} study shows that in BaBiO$_3$, Bi$^{3+}$ sites
can trap two holes from the valence band to form Bi$^{5+}$ cations. The
trapping is accompanied by large local lattice distortions, therefore the
composite particle consisting of the electronic-hole and the local lattice
phonon field forms a polaron. Our study clearly shows that even $sp$ elements
can trap carriers at lattice sites, if local lattice relaxations are
sufficiently large to screen the localised hole. The derived model describes
all relevant experimental results, and settles the issue of why hole doped
BaBiO$_3$ remains semiconducting upon moderate hole doping.


title: The solar Julia sets of basic quadratic Cremer polynomials

abstract:
  In general, little is known about the exact topological structure of Julia
sets containing a Cremer point. In this paper we show that there exist
quadratic Cremer Julia sets of positive area such that for a full Lebesgue
measure set of angles the impressions are degenerate, the Julia set is
connected im kleinen at the landing points of these rays, and these points are
contained in no other impression.


title:
A one-dimensional Vlasov-Maxwell equilibrium for the force-free Harris
  sheet

abstract:
  In this paper the first non-linear force-free Vlasov-Maxwell equilibrium is
presented. One component of the equilibrium magnetic field has the same spatial
structure as the Harris sheet, but whereas the Harris sheet is kept in force
balance by pressure gradients, in the force-free solution presented here force
balance is maintained by magnetic shear. Magnetic pressure, plasma pressure and
plasma density are constant. The method used to find the equilibrium is based
on the analogy of the one-dimensional Vlasov-Maxwell equilibrium problem to the
motion of a pseudo-particle in a two-dimensional conservative potential. This
potential is equivalent to one of the diagonal components of the plasma
pressure tensor. After finding the appropriate functional form for this
pressure tensor component, the corresponding distribution functions can be
found using a Fourier transform method. The force-free solution can be
generalized to a complete family of equilibria that describe the transition
between the purely pressure-balanced Harris sheet to the force-free Harris
sheet.


title:
On the necessity of Reidemeister move 2 for simplifying immersed planar
  curves

abstract:
  In 2001, Oestlund conjectured that Reidemeister moves 1 and 3 are sufficient
to describe a homotopy from any generic immersion from the circle into the
plane to the standard embedding of the circle. We show that this conjecture is
false.


title: Mapping change in large networks

abstract:
  Change is a fundamental ingredient of interaction patterns in biology,
technology, the economy, and science itself: Interactions within and between
organisms change; transportation patterns by air, land, and sea all change; the
global financial flow changes; and the frontiers of scientific research change.
Networks and clustering methods have become important tools to comprehend
instances of these large-scale structures, but without methods to distinguish
between real trends and noisy data, these approaches are not useful for
studying how networks change. Only if we can assign significance to the
partitioning of single networks can we distinguish meaningful structural
changes from random fluctuations. Here we show that bootstrap resampling
accompanied by significance clustering provides a solution to this problem. To
connect changing structures with the changing function of networks, we
highlight and summarize the significant structural changes with alluvial
diagrams and realize de Solla Price's vision of mapping change in science:
studying the citation pattern between about 7000 scientific journals over the
past decade, we find that neuroscience has transformed from an
interdisciplinary specialty to a mature and stand-alone discipline.


title: Detection of node group membership in networks with group overlap

abstract:
  Most networks found in social and biochemical systems have modular
structures. An important question prompted by the modularity of these networks
is whether nodes can be said to belong to a single group. If they cannot, we
would need to consider the role of "overlapping communities." Despite some
efforts in this direction, the problem of detecting overlapping groups remains
unsolved because there is neither a formal definition of overlapping community,
nor an ensemble of networks with which to test the performance of group
detection algorithms when nodes can belong to more than one group. Here, we
introduce an ensemble of networks with overlapping groups. We then apply three
group identification methods--modularity maximization, k-clique percolation,
and modularity-landscape surveying--to these networks. We find that the
modularity-landscape surveying method is the only one able to detect
heterogeneities in node memberships, and that those heterogeneities are only
detectable when the overlap is small. Surprisingly, we find that the k-clique
percolation method is unable to detect node membership for the overlapping
case.


title:
Decomposition Principles and Online Learning in Cross-Layer Optimization
  for Delay-Sensitive Applications

abstract:
  In this paper, we propose a general cross-layer optimization framework in
which we explicitly consider both the heterogeneous and dynamically changing
characteristics of delay-sensitive applications and the underlying time-varying
network conditions. We consider both the independently decodable data units
(DUs, e.g. packets) and the interdependent DUs whose dependencies are captured
by a directed acyclic graph (DAG). We first formulate the cross-layer design as
a non-linear constrained optimization problem by assuming complete knowledge of
the application characteristics and the underlying network conditions. The
constrained cross-layer optimization is decomposed into several cross-layer
optimization subproblems for each DU and two master problems. The proposed
decomposition method determines the necessary message exchanges between layers
for achieving the optimal cross-layer solution. However, the attributes (e.g.
distortion impact, delay deadline etc) of future DUs as well as the network
conditions are often unknown in the considered real-time applications. The
impact of current cross-layer actions on the future DUs can be characterized by
a state-value function in the Markov decision process (MDP) framework. Based on
the dynamic programming solution to the MDP, we develop a low-complexity
cross-layer optimization algorithm using online learning for each DU
transmission. This online algorithm can be implemented in real-time in order to
cope with unknown source characteristics, network dynamics and resource
constraints. Our numerical results demonstrate the efficiency of the proposed
online algorithm.


title:
Mathematical Framework for Fast and Rigorous Track Fit for the ZEUS
  Detector

abstract:
  In this note we present a mathematical framework for a rigorous approach to a
common track fit for trackers located in the inner region of the ZEUS detector.
The approach makes use of the Kalman filter and offers a rigorous treatment of
magnetic field inhomogeneity, multiple scattering and energy loss. We describe
mathematical details of the implementation of the Kalman filter technique with
a reduced amount of computations for a cylindrical drift chamber, barrel and
forward silicon strip detectors and a forward straw drift chamber. Options with
homogeneous and inhomogeneous field are discussed. The fitting of tracks in one
ZEUS event takes about of 20ms on standard PC.


title:
Physical model of continuous two-qubit parity measurement in a
  cavity-QED network

abstract:
  We propose and analyze a physical implementation of two-qubit parity
measurements as required for continuous error correction, assuming a setup in
which the individual qubits are strongly coupled to separate optical cavities.
A single optical probe beam scatters sequentially from the two cavities and the
continuous parity measurement is realized via fixed quadrature homodyne
photo-detection. We present models based on quantum stochastic differential
equations (QSDE's) for both an ideal continuous parity measurement and our
proposed cavity quantum electrodynamics (cavity QED) implementation; a recent
adiabatic elimination theorem for QSDE's is used to assert strong convergence
of the latter to the former in an appropriate limit of physical parameters.
Performance of the cavity QED scheme is studied via numerical simulation with
experimentally realistic parameters.


title:
Revisiting Molecular Dissociation in Density Functional Theory: A Simple
  Model

abstract:
  A two-electron one-dimensional model of a heteroatomic molecule composed of
two open-shell atoms is considered. Including only two electrons isolates and
examines the effect that the highest occupied molecular orbital has on the
Kohn-Sham potential as the molecule dissociates. We reproduce the
characteristic step and peak that previous high-level wavefunction methods have
shown to exist for real molecules in the low-density internuclear region. The
simplicity of our model enables us to investigate in detail their development
as a function of bond-length, with little computational effort, and derive
properties of their features in the dissociation limit. We show that the onset
of the step is coincident with the internuclear separation at which an avoided
crossing between the ground-state and lowest charge-transfer excited state is
approached. Although the step and peak features have little effect on the
ground-state energetics, we discuss their important consequences for dynamics
and response.


title: Rhythmogenic neuronal networks, pacemakers, and k-cores

abstract:
  Neuronal networks are controlled by a combination of the dynamics of
individual neurons and the connectivity of the network that links them
together. We study a minimal model of the preBotzinger complex, a small
neuronal network that controls the breathing rhythm of mammals through periodic
firing bursts. We show that the properties of a such a randomly connected
network of identical excitatory neurons are fundamentally different from those
of uniformly connected neuronal networks as described by mean-field theory. We
show that (i) the connectivity properties of the networks determines the
location of emergent pacemakers that trigger the firing bursts and (ii) that
the collective desensitization that terminates the firing bursts is determined
again by the network connectivity, through k-core clusters of neurons.


title: The f-vector of the descent polytope

abstract:
  For a positive integer n and a subset S of [n-1], the descent polytope DP_S
is the set of points x_1, ..., x_n in the n-dimensional unit cube [0,1]^n such
that x_i >= x_{i+1} for i in S and x_i <= x_{i+1} otherwise. First, we express
the f-vector of DP_S as a sum over all subsets of [n-1]. Second, we use certain
factorizations of the associated word over a two-letter alphabet to describe
the f-vector. We show that the f-vector is maximized when the set S is the
alternating set {1,3,5, ...}. We derive a generating function for the
f-polynomial F_S(t) of DP_S, written as a formal power series in two
non-commuting variables with coefficients in Z[t]. We also obtain the
generating function for the Ehrhart polynomials of the descent polytopes.


title: The structure of thin Lie algebras up to the second diamond

abstract:
  Thin Lie algebras are Lie algebras L, graded over the positive integers, with
all homogeneous components of dimension at most two, and satisfying a more
stringent but natural narrowness condition modeled on an analogous one for
pro-p groups. The two-dimensional homogeneous components of L, which include
that of degree one, are named diamonds. Infinite-dimensional thin Lie algebras
with various diamond patterns have been produced, over fields of positive
characteristic, as loop algebras of suitable finite-dimensional simple Lie
algebras, of classical or of Cartan type depending on the location of the
second diamond. The goal of this paper is a description of the initial
structure of a thin Lie algebra, up to the second diamond.
  Specifically, if L_k is the second diamond of L, then the quotient L/L^k is a
graded Lie algebras of maximal class. In characteristic not two, L/L^k is known
to be metabelian, and hence uniquely determined up to isomorphism by its
dimension k, which ranges in an explicitly known set of possible values. The
quotient L/L^k need not be metabelian in characteristic two. We describe here
all the possibilities for L/L^k up to isomorphism. In particular, we prove that
k+1 equals a power of two.


title:
A factorization theorem for classical group characters, with
  applications to plane partitions and rhombus tilings

abstract:
  We prove that a Schur function of rectangular shape $(M^n)$ whose variables
are specialized to $x_1,x_1^{-1},...,x_n,x_n^{-1}$ factorizes into a product of
two odd orthogonal characters of rectangular shape, one of which is evaluated
at $-x_1,...,-x_n$, if $M$ is even, while it factorizes into a product of a
symplectic character and an even orthogonal character, both of rectangular
shape, if $M$ is odd. It is furthermore shown that the first factorization
implies a factorization theorem for rhombus tilings of a hexagon, which has an
equivalent formulation in terms of plane partitions. A similar factorization
theorem is proven for the sum of two Schur functions of respective rectangular
shapes $(M^n)$ and $(M^{n-1})$.


title:
Resonance amplification of left-handed transmission at optical
  frequencies by stimulated emission of radiation in active metamaterials

abstract:
  We demonstrate that left-handed resonance transmission from metallic
metamaterial, composed of periodically arranged double rings, can be extended
to visible spectrum by introducing an active medium layer as the substrate. The
severe ohmic loss inside metals at optical frequencies is compensated by
stimulated emission of radiation in this active system. Due to the resonance
amplification mechanism of recently proposed lasing spaser, the left-handed
transmission band can be restored up to 610 nm wavelength, in dependence on the
gain coefficient of the active layer. Additionally, threshold gains for
different scaling levels of the double-ring unit are investigated to evaluate
the gain requirement of left-handed transmission restoration at different
frequency ranges.


title:
Big Bang Nucleosynthesis with Independent Neutrino Distribution
  Functions

abstract:
  We have performed new Big Bang Nucleosynthesis calculations which employ
arbitrarily-specified, time-dependent neutrino and antineutrino distribution
functions for each of up to four neutrino flavors. We self-consistently couple
these distributions to the thermodynamics, the expansion rate and scale
factor-time/temperature relationship, as well as to all relevant weak,
electromagnetic, and strong nuclear reaction processes in the early universe.
With this approach, we can treat any scenario in which neutrino or antineutrino
spectral distortion might arise. These scenarios might include, for example,
decaying particles, active-sterile neutrino oscillations, and active-active
neutrino oscillations in the presence of significant lepton numbers. Our
calculations allow lepton numbers and sterile neutrinos to be constrained with
observationally-determined primordial helium and deuterium abundances. We have
modified a standard BBN code to perform these calculations and have made it
available to the community.


title:
Recent topics of mesic atoms and mesic nuclei -- $\phi$ mesic nuclei
  exist ?--

abstract:
  We study $\phi$-meson production in nuclei to investigate the in-medium
modification of the $\phi$-meson spectral function at finite density. We
consider (${\bar p},\phi$), ($\gamma,p$) and ($\pi^-,n$) reactions to produce a
$\phi$-meson inside the nucleus and evaluate the effects of the medium
modifications to reaction cross sections. The structures of the bound states,
$\phi$-mesic nuclei, are also studied. For strong absorptive interaction cases,
we need to know the spectrum shape in a wide energy region to deduce the
properties of $\phi$.


title: Searching for Transient Pulses with the ETA Radio Telescope

abstract:
  Array-based, direct-sampling radio telescopes have computational and
communication requirements unsuited to conventional computer and cluster
architectures. Synchronization must be strictly maintained across a large
number of parallel data streams, from A/D conversion, through operations such
as beamforming, to dataset recording. FPGAs supporting multi-gigabit serial I/O
are ideally suited to this application. We describe a recently-constructed
radio telescope called ETA having all-sky observing capability for detecting
low frequency pulses from transient events such as gamma ray bursts and
primordial black hole explosions. Signals from 24 dipole antennas are processed
by a tiered arrangement of 28 commercial FPGA boards and 4 PCs with FPGA-based
data acquisition cards, connected with custom I/O adapter boards supporting
InfiniBand and LVDS physical links. ETA is designed for unattended operation,
allowing configuration and recording to be controlled remotely.


title: q-analog of tableau containment

abstract:
  We prove a $q$-analog of the following result due to McKay, Morse and Wilf:
the probability that a random standard Young tableau of size $n$ contains a
fixed standard Young tableau of shape $\lambda\vdash k$ tends to
$f^{\lambda}/k!$ in the large $n$ limit, where $f^{\lambda}$ is the number of
standard Young tableaux of shape $\lambda$. We also consider the probability
that a random pair $(P,Q)$ of standard Young tableaux of the same shape
contains a fixed pair $(A,B)$ of standard Young tableaux.


title: Masas and Bimodule Decompositions of $\rm{II}_{1}$ Factors

abstract:
  The measure-multiplicity-invariant for masas in $\rm{II}_{1}$ factors was
introduced in \cite{MR2261688} to distinguish masas that have the same
Puk\'{a}nszky invariant. In this paper we study the measure class in the
measure-multiplicity-invariant. This is equivalent to studying the standard
Hilbert space as an associated bimodule. We characterize the type of any masa
depending on the left-right-measure using Baire category methods (selection
principle of Jankov and von Neumann). We present a second proof of Chifan's
result on normalisers and a measure theoretic proof of the equivalence of weak
asymptotic homomorphism property (WAHP) and singularity that appeared in
\cite{MR2417416}.


title: The homogeneity conjecture for supergravity backgrounds

abstract:
  These notes record three lectures given at the workshop "Higher symmetries in
Physics", held at the Universidad Complutense de Madrid in November 2008. In
them we explain how to construct a Lie (super)algebra associated to a spin
manifold, perhaps with extra geometric data, and a notion of privileged
spinors. The typical examples are supersymmetric supergravity backgrounds;
although there are more classical instances of this construction. We focus on
two results: the geometric constructions of compact real forms of the simple
Lie algebras of type B_4, F_4 and E_8 from S^7, S^8 and S^15, respectively; and
the construction of the Killing superalgebra of eleven-dimensional supergravity
backgrounds. As an application of this latter construction we show that
supersymmetric supergravity backgrounds with enough supersymmetry are
necessarily locally homogeneous.


title: On the integers of the form $p^2+b^2+2^n$ and $b_1^2+b_2^2+2^{n^2}$

abstract:
  We prove that the sumset {p^2+b^2+2^n: p is prime and b,n\in N} has positive
lower density. We also construct a residue class with odd modulo, which
contains no integer of the form p^2+b^2+2^n. And similar results are
established for the sumset {b_1^2+b_2^2+2^{n^2}: b_1,b_2,n\in N}.


title:
Only rational homology spheres admit $\Omega(f)$ to be union of DE
  attractors

abstract:
  If there exists a diffeomorphism $f$ on a closed, orientable $n$-manifold $M$
such that the non-wandering set $\Omega(f)$ consists of finitely many
orientable $(\pm)$ attractors derived from expanding maps, then $M$ must be a
rational homology sphere; moreover all those attractors are of topological
dimension $n-2$.
  Expanding maps are expanding on (co)homologies.


title:
Age-Related Observations of Low Mass Pre-Main and Young Main Sequence
  Stars (Invited Review)

abstract:
  This overview summarizes the age dating methods available for young sub-solar
mass stars. Pre-main sequence age diagnostics include the Hertzsprung-Russell
(HR) diagram, spectroscopic surface gravity indicators, and lithium depletion;
asteroseismology is also showing recent promise. Near and beyond the zero-age
main sequence, rotation period or vsini and activity (coronal and
chromospheric) diagnostics along with lithium depletion serve as age proxies.
Other authors in this volume present more detail in each of the aforementioned
areas. Herein, I focus on pre-main sequence HR diagrams and address the
questions: Do empirical young cluster isochrones match theoretical isochrones?
Do isochrones predict stellar ages consistent with those derived via other
independent techniques? Do the observed apparent luminosity spreads at constant
effective temperature correspond to true age spreads? While definitive answers
to these questions are not provided, some methods of progression are outlined.


title: Stellar Age Estimation from ~3 Myr to ~3 Gyr

abstract:
  We present recent progress on quantitative estimation of stellar ages using
ind icators such as theoretical evolutionary tracks, rotation, rotation-driven
chrom ospheric and coronal activity, and lithium depletion. Our focus is on
roughly so lar-mass and solar-metallicity stars younger than the Sun. We
attempt to charac terize the systematic and random error sources and then
derive "best" ages alo ng with the dispersion in age arising among the various
age estimation methods. Our main application of these techniques is to the
evolution of debris disks.


title: Casimir Energy of 5D Warped System and Sphere Lattice Regularization

abstract:
  Casimir energy is calculated for the 5D electromagnetism and 5D scalar theory
in the {\it warped} geometry. It is compared with the flat
case(arXiv:0801.3064). A new regularization, called {\it sphere lattice
regularization}, is taken. In the integration over the 5D space, we introduce
two boundary curves (IR-surface and UV-surface) based on the {\it minimal area
principle}. It is a {\it direct} realization of the geometrical approach to the
{\it renormalization group}. The regularized configuration is {\it
closed-string like}. We do {\it not} take the KK-expansion approach. Instead,
the position/momentum propagator is exploited, combined with the {\it
heat-kernel method}. All expressions are closed-form (not KK-expanded form).
The {\it generalized} P/M propagators are introduced. We numerically evaluate
$\La$(4D UV-cutoff), $\om$(5D bulk curvature, warp parameter) and $T$(extra
space IR parameter) dependence of the Casimir energy. We present two {\it new
ideas} in order to define the 5D QFT: 1) the summation (integral) region over
the 5D space is {\it restricted} by two minimal surfaces (IR-surface,
UV-surface) ; or 2) we introduce a {\it weight function} and require the
dominant contribution is given by the {\it minimal surface}. Based on these, 5D
Casimir energy is {\it finitely} obtained after the {\it proper renormalization
procedure.} The {\it warp parameter} $\om$ suffers from the {\it
renormalization effect}. We examine the meaning of the weight function and
reach a {\it new definition} of the Casimir energy where {\it the 4D momenta(or
coordinates) are quantized} with the extra coordinate as the Euclidean time
(inverse temperature). We comment on the cosmological constant term and present
an answer to the problem at the end. Dirac's large number naturally appears.


title:
Oscillator model on Lie-algebraically deformed nonrelativistic
  space-time

abstract:
  The classical and quantum oscillator model on Lie-algebraically deformed
nonrelativistic space-time is introduced and analyzed. The corresponding
equations of motions are studied using mostly numerical methods. The
time-dependent energy spectrum is presented as well.


title:
$L^{p}$ Boundedness of Riesz transform related to Schr\"odinger
  operators on a manifold

abstract:
  We establish various $L^{p}$ estimates for the Schr\"odinger operator
$-\Delta+V$ on Riemannian manifolds satisfying the doubling property and a
Poincar\'e inequality, where $\Delta $ is the Laplace-Beltrami operator and $V$
belongs to a reverse H\"{o}lder class. At the end of this paper we apply our
result on Lie groups with polynomial growth.


title: CFT Hydrodynamics: Symmetries, Exact Solutions and Gravity

abstract:
  We consider the hydrodynamics of relativistic conformal field theories at
finite temperature and its slow motions limit, where it reduces to the
incompressible Navier-Stokes equations. The symmetries of the equations and
their solutions are analyzed. We construct exact solutions with finite time
singularities of one-dimensional relativistic conformal hydrodynamic motions,
and use them to generate multi-dimensional solutions via special conformal
transformations. These solutions, however, are shown to have no non-trivial
slow motions limit. A simple non-equilibrium steady state in the form of a
shock solution is constructed, and its inner structure is analyzed. We
demonstrate that the derivation of the gravitational dual description of
conformal hydrodynamics is analogous to the derivation of hydrodynamics
equations from the Boltzmann equation. The shock solution is shown to
correspond to a domain-wall solution in gravity. We show that the solutions to
the non-relativistic incompressible Navier-Stokes equations play a special role
in the construction of global solutions to gravity.


title:
CoRoT measures solar-like oscillations and granulation in stars hotter
  than the Sun

abstract:
  Oscillations of the Sun have been used to understand its interior structure.
The extension of similar studies to more distant stars has raised many
difficulties despite the strong efforts of the international community over the
past decades. The CoRoT (Convection Rotation and Planetary Transits) satellite,
launched in December 2006, has now measured oscillations and the stellar
granulation signature in three main sequence stars that are noticeably hotter
than the sun. The oscillation amplitudes are about 1.5 times as large as those
in the Sun; the stellar granulation is up to three times as high. The stellar
amplitudes are about 25% below the theoretic values, providing a measurement of
the nonadiabaticity of the process ruling the oscillations in the outer layers
of the stars.


title: Local Inertial Coordinate System and The Principle of Equivalence

abstract:
  In this paper, the local inertial coordinate system is calculated through
coordinate transformations from laboratory coordinate system. We derived the
same free falling equations as those in General Relativity. However, the
definitions of second and higher order covariant derivatives are different. Our
results are different from the classic view of the principle of equivalence,
and suggest that all the laws of physics in gravitational field can be given by
doing coordinate transformations from local inertial coordinate system to lab
coordinate system.


title:
Well-posedness of a parabolic moving-boundary problem in the setting of
  Wasserstein gradient flows

abstract:
  We develop a gradient-flow framework based on the Wasserstein metric for a
parabolic moving-boundary problem that models crystal dissolution and
precipitation. In doing so we derive a new weak formulation for this
moving-boundary problem and we show that this formulation is well-posed. In
addition, we develop a new uniqueness technique based on the framework of
gradient flows with respect to the Wasserstein metric. With this uniqueness
technique, the Wasserstein framework becomes a complete well-posedness setting
for this parabolic moving-boundary problem.


title: Piecewise linear loop quantum gravity

abstract:
  We define a modification of LQG in which graphs are required to consist in
piecewise linear edges, which we call piecewise linear LQG (plLQG). At the
diffeomorphism invariant level, we prove that plLQG is equivalent to standard
LQG, as long as one chooses the class of diffeomorphisms appropriately. That
is, we exhibit a unitary map between the diffeomorphism invariant Hilbert
spaces that maps physically equivalent operators into each other. In addition,
using the same ideas as in standard LQG, one can define a Hamiltonian and
Master constraint in plLQG, and the unitary map between plLQG and LQG then
provides an exact isomorphism of dynamics in the two frameworks.
  Furthermore, loop quantum cosmology (LQC) can be exactly embedded into plLQG.
This allows a prior program of the author to embed LQC into LQG at the
dynamical level to proceed. In particular, this allows a formal expression for
a physically motivated embedding of LQC into LQG at the diffeomorphism
invariant level to be given.


title: New method for deciphering free energy landscape of three-state proteins

abstract:
  We have developed a new simulation method to estimate the distance between
the native state and the first transition state, and the distance between the
intermediate state and the second transition state of a protein which
mechanically unfolds via intermediates. Assuming that the end-to-end extension
$\Delta R$ is a good reaction coordinate to describe the free energy landscape
of proteins subjected to an external force, we define the midpoint extension
$\Delta R^*$ between two transition states from either constant-force or
constant loading rate pulling simulations. In the former case, $\Delta R^*$ is
defined as a middle point between two plateaus in the time-dependent curve of
$\Delta R$, while, in the latter one, it is a middle point between two peaks in
the force-extension curve. Having determined $\Delta R^*$, one can compute
times needed to cross two transition state barriers starting from the native
state. With the help of the Bell and microscopic kinetic theory, force
dependencies of these unfolding times can be used to locate the intermediate
state and to extract unfolding barriers. We have applied our method to the
titin domain I27 and the fourth domain of {\em Dictyostelium discoideum}
filamin (DDFLN4), and obtained reasonable agreement with experiments, using the
C$_{\alpha}$-Go model.


title: Piezonuclear Neutrons

abstract:
  We report the results of neutron measurements carried out during the
application of ultrasounds to a solution containing only stable elements like
Iron and Chlorine, without any other radioactive source of any kind. These
measurements, carried out by CR39 detectors and a Boron TriFouride electronic
detector, evidenced the emission of neutron pulses. These pulses stand well
above the electronic noise and the background of the laboratory where the
measurements were carried out.


title:
Levy defects in fluctuating pattern of liquids. A quasi thermodynamic
  approach to the dynamic glass transition in classical molecular liquids

abstract:
  This theoretical paper is to advance a phenomenological, quasi thermodynamic
approach to the dynamics of classical liquids which uses the Levy distribution
of probability theory. Doubts from the chemical physics community about the
application of its unusual properties to this field are tried to be removed. In
particular, to understand the preponderant component of the Levy sum for Glarum
Levy defects and Fischer speckles, the classical mathematical proof [D. A.
Darling, Trans. Amer. Math. Soc. 73, 95 (1952)] for the existence and the
influence of this component is accompanied by addition of physical arguments
related to these defects. It is tried to explain an underlying fluctuating
spatial pattern of free volume with weak contrast and a pattern of mobility
with strong contrast, and to explain the characteristic lengths for the main
transition and the Fischer modes. The structure of the relaxation chart
(dynamic glass transition) and several properties of, and relations between,
the slower dispersion zones therein, are reviewed for classical glassforming
liquids of moderate complexity. For the main transition, the preponderant
component is pushed in the midst of the defect and induces the molecule to its
diffusion step across the cage door of the next neighbors. An Experimentum
Crucis for an indirect proof of the existence of defects - via characteristic
lengths - is also described.


title: Probing the Mechanisms of Fibril Formation Using Lattice Models

abstract:
  Using exhaustive Monte Carlo simulations we study the kinetics and mechanism
of fibril formation using lattice models as a function of temperature and the
number of chains. While these models are, at best, caricatures of peptides, we
show that a number of generic features thought to govern fibril assembly are
present in the toy model. The monomer, which contains eight beads made from
three letters (hydrophobic, polar, and charged), adopts a compact conformation
in the native state. The kinetics of fibril assembly occurs in three distinct
stages. In each stage there is a cascade of events that transforms the monomers
and oligomers to ordered structures. In the first "burst" stage highly mobile
oligomers of varying sizes form. The conversion to the aggregation-prone
conformation occurs within the oligomers during the second stage. As time
progresses, a dominant cluster emerges that contains a majority of the chains.
In the final stage, the aggregation-prone conformation particles serve as a
template onto which smaller oligomers or monomers can dock and undergo
conversion to fibril structures. The overall time for growth in the latter
stages is well described by the Lifshitz-Slyazov growth kinetics for
crystallization from super-saturated solutions.


title: Some geometrical aspects of control points for toric patches

abstract:
  We use ideas from algebraic geometry and dynamical systems to explain some
ways that control points influence the shape of a B\'ezier curve or patch. In
particular, we establish a generalization of Birch's Theorem and use it to
deduce sufficient conditions on the control points for a patch to be injective.
We also explain a way that the control points influence the shape via
degenerations to regular control polytopes. The natural objects of this
investigation are irrational patches, which are a generalization of
Krasauskas's toric patches, and include B\'ezier and tensor product patches as
important special cases.


title: On minimal prime graphs and posets

abstract:
  We show that there are four infinite prime graphs such that every infinite
prime graph with no infinite clique embeds one of these graphs. We derive a
similar result for infinite prime posets with no infinite chain or no infinite
antichain.


title: Ground state properties of a Tonks-Girardeau Gas in a periodic potential

abstract:
  In this paper, we investigate the ground-state properties of a bosonic
Tonks-Girardeau gas confined in a one-dimensional periodic potential. The
single-particle reduced density matrix is computed numerically for systems up
to $N=265$ bosons. Scaling analysis of the occupation number of the lowest
orbital shows that there are no Bose-Einstein Condensation(BEC) for the
periodically trapped TG gas in both commensurate and incommensurate cases. We
find that, in the commensurate case, the scaling exponents of the occupation
number of the lowest orbital, the amplitude of the lowest orbital and the
zero-momentum peak height with the particle numbers are 0, -0.5 and 1,
respectively, while in the incommensurate case, they are 0.5, -0.5 and 1.5,
respectively. These exponents are related to each other in a universal
relation.


title:
Claw-freeness, 3-homogeneous subsets of a graph and a reconstruction
  problem

abstract:
  We describe $Forb\{K_{1,3}, \overline {K_{1,3}}\}$, the class of graphs $G$
such that
  $G$ and its complement $ \overline{G}$ are claw-free. With few exceptions, it
is made of graphs whose connected components consist of cycles of length at
least 4, paths or isolated vertices, and of the complements of these graphs.
Considering the hypergraph ${\mathcal H} ^{(3)}(G)$ made of the 3-element
subsets of the vertex set of a graph $G$ on which $G$ induces a clique or an
independent subset, we deduce from above a description of the Boolean sum
$G\dot{+}G'$ of two graphs $G$ and $G'$ giving the same hypergraph. We indicate
the role of this latter description in a reconstruction problem of graphs up to
complementation.


title: Species competition: coexistence, exclusion and clustering

abstract:
  We present properties of Lotka-Volterra equations describing ecological
competition among a large number of competing species. First we extend to the
case of a non-homogeneous niche space stability conditions for solutions
representing species coexistence. Second, we discuss mechanisms leading to
species clustering and obtain an analytical solution for a lumped state in a
specific instance of the system. We also discuss how realistic ecological
interactions may result in different types of competition coefficients.


title: On scattered posets with finite dimension

abstract:
  We discuss a possible characterization, by means of forbidden configurations,
of posets which are embeddable in a product of finitely many scattered chains.


title: Directional Coupling for Quantum Computing and Communication

abstract:
  We introduce the concept of directional coupling, i.e., the selective
transfer of a state between adjacent quantum wires, in the context of quantum
computing and short-distance communication. Our analysis rests upon a
mathematical analogy between a dual-channel directional coupler and a composite
spin system.


title: Contact line dynamics in binary lattice Boltzmann simulations

abstract:
  We show that, when a single relaxation time lattice Boltzmann algorithm is
used to solve the hydrodynamic equations of a binary fluid for which the two
components have different viscosities, strong spurious velocities in the steady
state lead to incorrect results for the equilibrium contact angle. We identify
the origins of these spurious currents, and demonstrate how the results can be
greatly improved by using a lattice Boltzmann method based on a
multiple-relaxation-time algorithm. By considering capillary filling we
describe the dependence of the advancing contact angle on the interface
velocity.


title: The quadrupole moment of slowly rotating fluid balls

abstract:
  In this paper we use the second order formalism of Hartle to study slowly and
rigidly rotating stars with focus on the quadrupole moment of the object. The
second order field equations for the interior fluid are solved numerically for
different classes of possible equations of state and these solutions are then
matched to a vacuum solution that includes the general asymptotically flat
axisymmetric metric to second order, using the Darmois-Israel procedure. For
these solutions we find that the quadrupole moment differs from that of the
Kerr metric, as has also been found for some equations of state in other
studies. Further we consider the post-Minkowskian limit analytically. In the
paper we also illustrate how the relativistic multipole moments can be
calculated from a complex gravitational potential.


title:
Multiple scattering of waves by a pair of gravitationally stratified
  flux tubes

abstract:
  We study the near-field coupling of a pair of flux tubes embedded in a
gravitationally stratified environment. The mutual induction of the near-field
{\it jackets} of the two flux tubes can considerably alter the scattering
properties of the system, resulting in sizable changes in the magnitudes of
scattering coefficients and bizarre trends in the phases. The dominant length
scale governing the induction zone turns out to be approximately half the
horizontal wave length of the incident mode, a result that fits in quite
pleasantly with extant theories of scattering. Higher-$\beta$ flux tubes are
more strongly coupled than weaker ones, a consequence of the greater role that
the near-field jacket modes play in the such tubes. We also comment on the
importance of incorporating the effects of multiple scattering when studying
the effects of mode absorption in plage and interpreting related scattering
measurements. That the near-field plays such an important role in the
scattering process lends encouragement to the eventual goal of observationally
resolving sub-wavelength features of flux tubes using techniques of
helioseismology.


title: Holographic Geometry and Noise in Matrix Theory

abstract:
  Using Matrix Theory as a concrete example of a fundamental holographic
theory, we show that the emergent macroscopic spacetime displays a new
macroscopic quantum structure, holographic geometry, and a new observable
phenomenon, holographic noise, with phenomenology similar to that previously
derived on the basis of a quasi-monochromatic wave theory. Traces of matrix
operators on a light sheet with a compact dimension of size $R$ are interpreted
as transverse position operators for macroscopic bodies. An effective quantum
wave equation for spacetime is derived from the Matrix Hamiltonian. Its
solutions display eigenmodes that connect longitudinal separation and
transverse position operators on macroscopic scales. Measurements of transverse
relative positions of macroscopically separated bodies, such as signals in
Michelson interferometers, are shown to display holographic nonlocality,
indeterminacy and noise, whose properties can be predicted with no parameters
except $R$. Similar results are derived using a detailed scattering calculation
of the matrix wavefunction. Current experimental technology will allow a
definitive and precise test or validation of this interpretation of holographic
fundamental theories. In the latter case, they will yield a direct measurement
of $R$ independent of the gravitational definition of the Planck length, and a
direct measurement of the total number of degrees of freedom.


title: The Dark Universe Riddle

abstract:
  In this work we review some of the theoretical efforts and experimental
evidences related to Dark matter and Dark energy problems in the universe.
These dilemmas show us how incomplete our knowledge of gravity is, and how our
concepts about the universe must at least be revised. Mainly, on the Wilkinson
Microwave Anisotropy Probe (WMAP) fifth year, the data indicates that more than
90% of the total energy density of the universe is dark. Here we discuss the
impact of these phenomena imprint on gravitational and quantum field theory's
standard history. Moreover, we point out some recent and upcoming projects on
Cosmology intended to shed light on these problems.


title: The Spin Glass Phase in the Four-State, Three-Dimensional Potts Model

abstract:
  We perform numerical simulations, including parallel tempering, on the Potts
glass model with binary random quenched couplings using the JANUS
application-oriented computer. We find and characterize a glassy transition,
estimating the location of the transition and the value of the critical
exponents. We show that there is no ferromagnetic transition in a large
temperature range around the glassy critical temperature. We also compare our
results with those obtained recently on the "random permutation" Potts glass.


title:
The Ks-band Tully-Fisher Relation - A Determination of the Hubble
  Parameter from 218 ScI Galaxies and 16 Galaxy Clusters

abstract:
  The value of the Hubble Parameter (H0) is determined using the
morphologically type dependent Ks-band Tully-Fisher Relation (K-TFR). The slope
and zero point are determined using 36 calibrator galaxies with ScI morphology.
Calibration distances are adopted from direct Cepheid distances, and group or
companion distances derived with the Surface Brightness Fluctuation Method or
Type Ia Supernova. Distances are determined to 16 galaxy clusters and 218 ScI
galaxies with minimum distances of 40.0 Mpc. From the 16 galaxy clusters a
weighted mean Hubble Parameter of H0=84.2 +/-6 km s-1 Mpc-1 is found. From the
218 ScI galaxies a Hubble Parameter of H0=83.4 +/-8 km s-1 Mpc-1 is found. When
the zero point of the K-TFR is corrected to account for recent results that
find a Large Magellanic Cloud distance modulus of 18.39 +/-0.05 a Hubble
Parameter of 88.0 +/-6 km s-1 Mpc-1 is found. A comparison with the results of
the Hubble Key Project (Freedman et al 2001) is made and discrepancies between
the K-TFR distances and the HKP I-TFR distances are discussed. Implications for
Lamda-CDM cosmology are considered with H0=84 km s-1 Mpc-1. (Abridged)


title: Artinian and non-artinian local cohomology modules

abstract:
  Let $M$ be a finite module over a commutative noetherian ring $R$. For ideals
$\fa$ and $\fb$ of $R$, the relations between cohomological dimensions of $M$
with respect to $\fa, \fb$, $\fa\cap\fb$ and $\fa+ \fb$ are studied. When $R$
is local, it is shown that $M$ is generalized Cohen-Macaulay if there exists an
ideal $\fa$ such that all local cohomology modules of $M$ with respect to $\fa$
have finite lengths. Also, when $r$ is an integer such that $0\leq r<
\dim_R(M)$, any maximal element $\fq$ of the non-empty set of ideals $\{\fa$ :
$\H_\fa^i(M)$ is not artinian for some $i$, $i\geq r$$\}$ is a prime ideal and
that all Bass numbers of $\H_\fq^i(M)$ are finite for all $i\geq r$.


title: A Topos Formulation of Consistent Histories

abstract:
  Topos theory has been suggested by Doring and Isham as an alternative
mathematical structure with which to formulate physical theories. In particular
it has been used to reformulate standard quantum mechanics in such a way that a
novel type of logic is used to represent propositions. In this paper we extend
this formulation to include temporally-ordered collections of propositions as
opposed to single-time propositions. That is to say, we have developed a
quantum history formalism in the language of topos theory where truth values
can be assigned to temporal propositions. We analyse the extent to which such
truth values can be derived from the truth values of the constituent,
single-time propositions.


title: Unary finite automata vs. arithmetic progressions

abstract:
  We point out a subtle error in the proof of Chrobak's theorem that every
unary NFA can be represented as a union of arithmetic progressions that is at
most quadratically large. We propose a correction for this and show how
Martinez's polynomial time algorithm, which realizes Chrobak's theorem, can be
made correct accordingly. We also show that Martinez's algorithm cannot be
improved to have logarithmic space, unless L = NL.


title:
Hermitian Symmetric Spaces of Tube Type and Multivariate
  Meixner-Pollaczek Polynomials

abstract:
  Harmonic analysis on Hermitian symmetric spaces of tube type is a natural
framework for introducing multivariate Meixner-Pollaczek polynomials. Their
main properties are established in this setting: generating and determinantal
formulae, difference equations. As an application we consider the problem of
evaluating moments related to a multivariate Barnes type integral involving the
Harish-Chandra $c$-function of a symmetric cone.


title:
Group theory analysis of electrons and phonons in N-layer graphene
  systems

abstract:
  In this work we study the symmetry properties of electrons and phonons in
graphene systems as function of the number of layers. We derive the selection
rules for the electron-radiation and for the electron-phonon interactions at
all points in the Brillouin zone. By considering these selection rules, we
address the double resonance Raman scattering process. The monolayer and
bilayer graphene in the presence of an applied electric field are also
discussed.


title: Foundations of anisotropic relativistic mechanics

abstract:
  We lay down the foundations of particle dynamics in mechanical theories that
satisfy the relativity principle and whose kinematics can be formulated
employing reference frames of the type usually adopted in special relativity.
Such mechanics allow for the presence of anisotropy, both conventional (due to
non-standard synchronisation protocols) and real (leading to detectable
chronogeometrical effects, independent of the choice of synchronisation). We
give a general method for finding the fundamental dynamical quantities
(Lagrangian, energy and momentum), and write their explicit expression in all
the kinematics compatible with the basic requirements. We also write the
corresponding dispersion relations and outline a formulation of these theories
in terms of a pseudo-Finslerian spacetime geometry. Although the treatment is
restricted to the case of one spatial dimension, an extension to three
dimensions is almost straightforward.


title: SDSS J162718.39+120435.0 - a dwarf nova in the period gap

abstract:
  SDSS J162718.39+120435.0 was suspected of being a dwarf nova from
spectroscopic observations made available by the Sloan Digital Sky Survey.
Photometry conducted during the 2008 outburst, the first ever outburst of this
object detected and followed up in real time, shows that the outburst reached
magnitude 14.6 at maximum, had an amplitude of 4.6 magnitudes and lasted for at
least 18 days. Common superhumps were detected with an amplitude of up to 0.4
magnitudes, confirming it to be a member of the SU UMa family. Initially the
superhump period, Psh, was 0.10993(7) days (2.638 hours), but it subsequently
reduced to Psh = 0.10890(9) days (2.614 hours) later in the outburst. The
period change corresponds to the end of the plateau period of the outburst. The
orbital period, Porb, was estimated from the two Psh values as between 0.1026 d
and 0.1016 d, which places SDSS1627 near the centre of the period gap in the
orbital period distribution of cataclysmic variables.


title: Dynamics of Strategic Three-Choice Voting

abstract:
  In certain parliamentary democracies, there are two major parties that move
in and out of power every few elections, and a third minority party that
essentially never governs. We present a simple model to account for this
phenomenon, in which minority party supporters sometimes vote ideologically
(for their party) and sometimes strategically (against the party they like the
least). The competition between these disparate tendencies reproduces the
empirical observation of two parties that frequently exchange majority status
and a third party that is almost always in the minority.

categories: physics.soc-ph cond-mat.stat-mech nlin.AO physics.gen-ph


title: Entanglement control in coupled two-mode boson systems

abstract:
  A two-mode boson model, widely used for the physics of fast rotating nuclei
and Bose-Einstein condensates, is studied in the context of entanglement
control. We derive an analytical expression for the entanglement between the
fields in this model as a function of time. We found that depending on the
interaction strengths between boson modes and the nature of the initial boson
states the dynamical evolution of the entanglement and the squeezing can occur
independently.


abstract:
  We investigate the consequences of the ambiguity of minimal coupling
procedure for Einstein-Cartan gravity with Holst term and fermions. A new
insight is provided into the nature and physical relevance of coupling
procedures considered hitherto in the context of Ashtekar-Barbero-Immirzi
formalism with fermions. The issue of physical effects of the Immirzi parameter
in semi--classical theory is reinvestigated. We argue that the conclusive
answer to the question of its measurability will not be possible until the more
fundamental problem of nonuniqueness of gravity--induced fermion interaction in
Einstein-Cartan theory is solved.


title:
Saturation and Confinement: Analyticity, Unitarity and AdS/CFT
  Correspondence

abstract:
  In $1/N_c$ expansion, analyticity and crossing lead to crossing even and odd
($C=\pm 1$) vacuum exchanges at high-energy, the {\em Pomeron} and the {\em
Odderon}. We discuss how, using {\em String/Gauge duality}, these can be
identified with a reggeized {\em Graviton} and the anti-symmetric {\em
Kalb-Ramond fields} in $AdS$ background. With confinement, these Regge
singularities interpolate with glueball states. We also discuss unitarization
based on eikonal sum in $AdS$.


title:
Comparison of volumes of convex bodies in real, complex, and
  quaternionic spaces

abstract:
  The classical Busemann-Petty problem (1956) asks, whether origin-symmetric
convex bodies in $\mathbb {R}^n$ with smaller hyperplane central sections
necessarily have smaller volumes. It is known, that the answer is affirmative
if $n\le 4$ and negative if $n>4$. The same question can be asked when volumes
of hyperplane sections are replaced by other comparison functions having
geometric meaning. We give unified exposition of this circle of problems in
real, complex, and quaternionic $n$-dimensional spaces. All cases are treated
simultaneously. In particular, we show that the Busemann-Petty problem in the
quaternionic $n$-dimensional space has an affirmative answer if and only if $n
=2$. The method relies on the properties of cosine transforms on the unit
sphere. Possible generalizations are discussed.


title: Interlaced solitons and vortices in coupled DNLS lattices

abstract:
  In the present work, we propose a new set of coherent structures that arise
in nonlinear dynamical lattices with more than one components, namely
interlaced solitons. These are waveforms in which in the relevant
anti-continuum limit, i.e. when the sites are uncoupled, one component has
support where the other component does not. We illustrate systematically how
one can combine dynamically stable unary patterns to create ones such for the
binary case of two-components. In the one-dimensional setting, we provide also
a detailed theoretical analysis of the existence and stability of these
waveforms, while in higher dimensions, where such analytical computations are
far more involved, we resort to corresponding numerical computations. Lastly,
we perform direct numerical simulations to showcase how these structures break
up, when exponentially or oscillatorily unstable, to structures with a smaller
number of participating sites.


title:
Dynamics of the time to the most recent common ancestor in a large
  branching population

abstract:
  If we follow an asexually reproducing population through time, then the
amount of time that has passed since the most recent common ancestor (MRCA) of
all current individuals lived will change as time progresses. The resulting
"MRCA age" process has been studied previously when the population has a
constant large size and evolves via the diffusion limit of standard
Wright--Fisher dynamics. For any population model, the sample paths of the MRCA
age process are made up of periods of linear upward drift with slope +1
punctuated by downward jumps. We build other Markov processes that have such
paths from Poisson point processes on $\mathbb{R}_{++}\times\mathbb{R}_{++}$
with intensity measures of the form $\lambda\otimes\mu$ where $\lambda$ is
Lebesgue measure, and $\mu$ (the "family lifetime measure") is an arbitrary,
absolutely continuous measure satisfying $\mu((0,\infty))=\infty$ and
$\mu((x,\infty))<\infty$ for all $x>0$. Special cases of this construction
describe the time evolution of the MRCA age in $(1+\beta)$-stable continuous
state branching processes conditioned on nonextinction--a particular case of
which, $\beta=1$, is Feller's continuous state branching process conditioned on
nonextinction. As well as the continuous time process, we also consider the
discrete time Markov chain that records the value of the continuous process
just before and after its successive jumps. We find transition probabilities
for both the continuous and discrete time processes, determine when these
processes are transient and recurrent and compute stationary distributions when
they exist.


title: On the Taylor Coefficients of the Hurwitz Zeta Function

abstract:
  We find a representation for the Maclaurin coefficients of the Hurwitz
zeta-function in terms of semi-convergent series involving the Bernoulli
polynomials and the Stirling numbers of the first kind. In particular, this
gives a representation for the coefficients of the Riemann zeta function. Our
main instrument is a certain series transformation formula. A similar result is
proved also for the Maclaurin coefficients of the Lerch zeta function.


title: On (strongly) Gorenstein (semi)hereditary rings

abstract:
  In this paper, we introduce and study the rings of Gorenstein homological
dimensions small or equal than 1, which we call Gorenstein (semi)hereditary
rings, specially particular cases of these rings, which we call strongly
Gorenstein (semi)hereditary rings.