title:
Instability of wormholes supported by a ghost scalar field. I. Linear
  stability analysis

abstract:
  We examine the linear stability of static, spherically symmetric wormhole
solutions of Einstein's field equations coupled to a massless ghost scalar
field. These solutions are parametrized by the areal radius of their throat and
the product of the masses at their asymptotically flat ends. We prove that all
these solutions are unstable with respect to linear fluctuations and possess
precisely one unstable, exponentially in time growing mode. The associated time
scale is shown to be of the order of the wormhole throat divided by the speed
of light. The nonlinear evolution is analyzed in a subsequent article.


title:
IR Dust Bubbles: Probing the Detailed Structure and Young Massive
  Stellar Populations of Galactic HII Regions

abstract:
  We present an analysis of wind-blown, parsec-sized, mid-infrared bubbles and
associated star-formation using GLIMPSE/IRAC, MIPSGAL/MIPS and MAGPIS/VLA
surveys. Three bubbles from the Churchwell et al. (2006) catalog were selected.
The relative distribution of the ionized gas (based on 20 cm emission), PAH
emission (based on 8 um, 5.8 um and lack of 4.5 um emission) and hot dust (24
um emission) are compared. At the center of each bubble there is a region
containing ionized gas and hot dust, surrounded by PAHs. We identify the likely
source(s) of the stellar wind and ionizing flux producing each bubble based
upon SED fitting to numerical hot stellar photosphere models. Candidate YSOs
are also identified using SED fitting, including several sites of possible
triggered star formation.


title: Photons from nuclear collisions at RHIC energies

abstract:
  We model the hot and dense strongly interacting mater produced in high energy
heavy ion collisions using relativistic hydrodynamics. Several different
sources of real photons produced during these collisions are considered and
their relative importance is assessed. We include contributions from QCD jets,
which are allowed to loose and gain energy as they proceed through the hot
matter. This is treated within the AMY formalism. We obtain photon spectra,
R_{AA}, and v_2 in agreement with measurements performed by the PHENIX
collaboration.


title:
Search for a scalar or vector particle decaying into Zgamma in ppbar
  collisions at sqrt(s) = 1.96 TeV

abstract:
  We present a search for a narrow scalar or vector resonance decaying into
Zgamma with a subsequent Z decay into a pair of electrons or muons. The data
for this search were collected with the D0 detector at the Fermilab Tevatron
ppbar collider at a center of mass energy sqrt(s) = 1.96 TeV. Using 1.1 (1.0)
fb-1 of data, we observe 49 (50) candidate events in the electron (muon)
channel, in good agreement with the standard model prediction. From the
combination of both channels, we derive 95% C.L. upper limits on the cross
section times branching fraction (sigma x B) into Zgamma. These limits range
from 0.19 (0.20) pb for a scalar (vector) resonance mass of 600 GeV/c^2 to 2.5
(3.1) pb for a mass of 140 GeV/c^2.


title: Local additive estimation

abstract:
  Additive models are popular in high--dimensional regression problems because
of flexibility in model building and optimality in additive function
estimation. Moreover, they do not suffer from the so-called {\it curse of
dimensionality} generally arising in nonparametric regression setting. Less
known is the model bias incurring from the restriction to the additive class of
models. We introduce a new class of estimators that reduces additive model bias
and at the same time preserves some stability of the additive estimator. This
estimator is shown to partially relieve the dimensionality problem as well. The
new estimator is constructed by localizing the assumption of additivity and
thus named {\it local additive estimator}. Implementation can be easily made
with any standard software for additive regression. For detailed analysis we
explicitly use the smooth backfitting estimator by Mammen, Linton and Nielsen
(1999).


title:
Unified $(q;\alpha,\beta,\gamma;\nu)$-deformation of one-parametric
  q-deformed oscillator algebras

abstract:
  We define a generalized $(q;\alpha,\beta,\gamma;\nu)$-deformed oscillator
algebra and study the number of its characteristics. We describe the structure
function of deformation, analyze the classification of irreducible
representations and discuss the asymptotic spectrum behaviour of the
Hamiltonian. For a special choice of the deformation parameters we construct
the deformed oscillator with discrete spectrum of its "quantized coordinate"
operator. We establish its connection with the (generalized) discrete Hermite I
polynomials.


title:
Theory of Helimagnons in Itinerant Quantum Systems III: Quasiparticle
  Description

abstract:
  In two previous papers we studied the problem of electronic properties in a
system with long-ranged helimagnetic order caused by itinerant electrons. A
standard many-fermion formalism was used. The calculations were quite tedious
because different spin projections were coupled in the action, and because of
the inhomogeneous nature of a system with long-ranged helimagnetic order. Here
we introduce a canonical transformation that diagonalizes the action in spin
space, and maps the problem onto a homogeneous fermion problem. This
transformation to quasiparticle degrees of freedom greatly simplifies the
calculations. We use the quasiparticle action to calculate single-particle
properties, in particular the single-particle relaxation rate. We first
reproduce our previous results for clean systems in a simpler fashion, and then
study the much more complicated problem of three-dimensional itinerant
helimagnets in the presence of an elastic relaxation rate 1/tau due to
nonmagnetic quenched disorder. Our most important result involves the
temperature dependence of the single-particle relaxation rate in the ballistic
limit, tau^2 T\epsilon_F > 1, for which we find a linear temperature
dependence. We show how this result is related to a similar result found in
nonmagnetic two-dimensional disordered metals.


title:
Nanoengineering of a Negative-Index Binary-Staircase Lens for the Optics
  Regime

abstract:
  We show that a binary-staircase optical element can be engineered to exhibit
an effective negative index of refraction, thereby expanding the range of
optical properties theoretically available for future optoelectronic devices.
The mechanism for achieving a negative-index lens is based on exploiting the
periodicity of the surface corrugation. By designing and nanofabricating a
plano-concave binary-staircase lens in the InP/InGaAsP platform, we have
experimentally demonstrated at 1.55 microns that such negative-index concave
lenses can focus plane waves. The beam propagation in the lens was studied
experimentally and was in excellent agreement with the three-dimensional
finite-difference time-domain numerical simulations.


title:
Backward Uniqueness and the existence of the spectral limit for some
  parabolic SPDEs

abstract:
  The aim of this article is to study the asymptotic behaviour for large times
of solutions to a certain class of stochastic partial differential equations of
parabolic type. In particular, we will prove the backward uniqueness result and
the existence of the spectral limit for abstract SPDEs and then show how these
results can be applied to some concrete linear and nonlinear SPDEs. For
example, we will consider linear parabolic SPDEs with gradient noise and
stochastic NSEs with multiplicative noise. Our results generalize the results
proved in \cite{[Ghidaglia-1986]} for deterministic PDEs.


title:
Stellar Structure of Dark Stars: a first phase of Stellar Evolution due
  to Dark Matter Annihilation

abstract:
  Dark Stars are the very first phase of stellar evolution in the history of
the universe: the first stars to form (typically at redshifts $z \sim 10-50$)
are powered by heating from dark matter (DM) annihilation instead of fusion (if
the DM is made of particles which are their own antiparticles). We find
equilibrium polytropic configurations for these stars; we start from the time
DM heating becomes important ($M \sim 1-10 M_\odot$) and build up the star via
accretion up to 1000 M$_\odot$. The dark stars, with an assumed particle mass
of 100 GeV, are found to have luminosities of a few times $10^6$ L$_\odot$,
surface temperatures of 4000--10,000 K, radii $\sim 10^{14}$ cm, lifetimes of
at least $ 0.5$ Myr, and are predicted to show lines of atomic and molecular
hydrogen. Dark stars look quite different from standard metal-free stars
without DM heating: they are far more massive (e.g. $\sim 800 M_\odot$ for 100
GeV WIMPs), cooler, and larger, and can be distinguished in future
observations, possibly even by JWST or TMT.


title:
Testing the Evolutionary Link Between Submillimetre Galaxies and
  Quasars: CO Observations of QSOs at z~2

abstract:
  We have used the IRAM Plateau de Bure mm interferometer and the UKIRT 1-5 um
Imager Spectrometer to test the connection between the major phases of spheroid
growth and nuclear accretion by mapping CO emission in nine submm-detected QSOs
at z=1.7-2.6 with black hole (BH) masses derived from near-infrared
spectroscopy. With a previously published QSO, we present sensitive CO(3-2)
observations of 10 submm-detected QSOs selected at the epoch of peak activity
in both QSOs and submm galaxies (SMGs). CO is detected in 5/6 very optically
luminous (M_B~-28) submm-detected QSOs with BH masses M_BH~10^9-10^10 Msun,
confirming the presence of large gas reservoirs of M_gas~3.4x10^10 Msun.
However, we find that their BH masses are ~30 times too large and their surface
density is ~300 times too small to be related to typical SMGs in an
evolutionary sequence. Conversely, we measure weaker CO emission in four
fainter (M_B~-25) submm-detected QSOs with properties, BH masses (M_BH~5x10^8
Msun), and surface densities similar to SMGs. These QSOs appear to lie near the
local M_BH/M_sph relation, making them plausible `transition objects' in the
proposed evolutionary sequence linking QSOs to the formation of massive young
galaxies and BHs at high-redshift. We show that SMGs have a higher incidence of
bimodal CO line profiles than seen in our QSO sample, which we interpret as an
effect of their relative inclinations, with the QSOs seen more face-on.
Finally, we find that the gas masses of the four fainter submm-detected QSOs
imply that their star formation episodes could be sustained for ~10 Myr, and
are consistent with representing a phase in the formation of massive galaxies
which overlaps a preceding SMG starburst phase, before subsequently evolving
into a population of present-day massive ellipticals. [abridged]


title: Non-gaussianity from the bispectrum in general multiple field inflation

abstract:
  We study the non-gaussianity from the bispectrum in multi-field inflation
models with a general kinetic term. The models include the multi-field
K-inflation and the multi-field Dirac-Born-Infeld (DBI) inflation as special
cases. We find that, in general, the sound speeds for the adiabatic and entropy
perturbations are different and they can be smaller than 1. Then the
non-gaussianity can be enhanced. The multi-field DBI-inflation is shown to be a
special case where both sound speeds are the same due to a special form of the
kinetic term. We derive the exact second and third order actions including
metric perturbations. In the small sound speed limit and at leading order in
the slow-roll expansion, we derive the three point function for the curvature
perturbation which depends on both adiabatic and entropy perturbations. The
contribution from the entropy perturbations has a different momentum dependence
if the sound speed for the entropy perturbations is different from the
adiabatic one, which provides a possibility to distinguish the multi-field
models from single field models. On the other hand, in the multi-field DBI
case, the contribution from the entropy perturbations has the same momentum
dependence as the pure adiabatic contributions and it only changes the
amplitude of the three point function. This could help to ease the constraints
on the DBI-inflation models.


title: Microscopic expression for the heat in the adiabatic basis

abstract:
  We derive a microscopic expression for the instantaneous diagonal elements of
the density matrix $\rho_{nn}(t)$ in the adiabatic basis for an arbitrary time
dependent process in a closed Hamiltonian system. If the initial density matrix
is stationary (diagonal) then this expression contains only squares of absolute
values of matrix elements of the evolution operator, which can be interpreted
as transition probabilities. We then derive the microscopic expression for the
heat defined as the energy generated due to transitions between instantaneous
energy levels. If the initial density matrix is passive (diagonal with
$\rho_{nn}(0)$ monotonically decreasing with energy) then the heat is
non-negative in agreement with basic expectations of thermodynamics. Our
findings also can be used for systematic expansion of various observables
around the adiabatic limit.


title: The early-type dwarf galaxy population of the Hydra I cluster

abstract:
  We analyse the properties of the early-type dwarf galaxy population in the
Hydra I cluster. We investigate the galaxy luminosity function (LF), the
colour-magnitude relation (CMR), and the magnitude-surface brightness relation
down to M_V~-10 mag. Another goal of this study is to find candidates for
ultra-compact dwarf galaxies (UCDs). Two spectroscopic surveys performed with
Magellan I/LDSS2 and VLT/VIMOS, as well as deep VLT/FORS1 images in V and I
bands were examined. We identify cluster members by radial velocity
measurements and select other cluster galaxy candidates by their morphology.
One possible UCD candidate with M_V=-13.26 mag is found. Our sample of 100
morphologically selected dwarf galaxies defines a CMR that extends the CMR of
the giant cluster galaxies to the magnitude limit of our survey (M_V~-10 mag).
It matches the relations found for the Local Group and the Fornax cluster
dwarfs almost perfectly. The Hydra I dwarfs also follow a magnitude-surface
brightness relation similar to that of the LG dwarfs. Moreover, we observe a
continuous relation for dwarf galaxies and giant early-type galaxies when
plotting the central surface brightness \mu_0 of a S\'ersic model vs. the
galaxy magnitude. The effective radius is found to be largely independent of
the luminosity for M_V>-18 mag, being R_e~0.8 kpc. We derive a very flat
faint-end slope of the LF (\alpha = -1.13 \pm 0.04) from fitting a Schechter
function, whereas fitting a power law for M_V>-14 mag gives \alpha = -1.40 \pm
0.18. Our findings suggest that early-type dwarf and giant galaxies are the
same class of objects. The similarity of the dwarf galaxy scaling relations to
other environments implies that internal processes could be more important for
their global photometric properties than external influences. (abridged)


title: Evidence for primordial mass segregation in globular clusters

abstract:
  We have studied the dissolution of initially mass segregated and unsegregated
star clusters due to two-body relaxation in external tidal fields, using
Aarseth's collisional N-body code NBODY4 on GRAPE6 special-purpose computers.
When extrapolating results of initially not mass segregated models to globular
clusters, we obtain a correlation between the time until destruction and the
slope of the mass function, in the sense that globular clusters which are
closer to dissolution are more strongly depleted in low-mass stars. This
correlation fits observed mass functions of most globular clusters. The mass
functions of several globular clusters are however more strongly depleted in
low-mass stars than suggested by these models. Such strongly depleted mass
functions can be explained if globular clusters started initially mass
segregated. Primordial mass segregation also explains the correlation between
the slope of the stellar mass function and the cluster concentration which was
recently discovered by De Marchi et al. (2007). In this case, it is possible
that all globular clusters started with a mass function similar to that seen in
young open clusters in the present-day universe, at least for stars below m=0.8
Msun. This argues for a near universality of the mass function for different
star formation environments and metallicities in the range -2 < [Fe/H] < 0. We
finally describe a novel algorithm which can initialise stationary mass
segregated clusters with arbitrary density profile and amount of mass
segregation.


title: Primordial non-gaussianity from multiple curvaton decay

abstract:
  We study a model where two scalar fields, that are subdominant during
inflation, decay into radiation some time after inflation has ended but before
primordial nucleosynthesis. Perturbations of these two curvaton fields can be
responsible for the primordial curvature perturbation. We write down the full
non-linear equations that relate the primordial perturbation to the curvaton
perturbations on large scales, and solve them in a sudden-decay approximation.
We calculate the power spectrum of the primordial perturbation, and finally go
to second order to find the non-linearity parameter, fNL.
  Not surprisingly, we find large positive values of fNL if the energy
densities of the curvatons are sub-dominant when they decay, as in the single
curvaton case. But we also find a novel effect, which can be present only in
multi-curvaton models: fNL becomes large even if the curvatons dominate the
total energy density in the case when the inhomogeneous radiation produced by
the first curvaton decay is diluted by the decay of a second nearly homogeneous
curvaton. The minimum value min(fNL)=-5/4 which we find is the same as in the
single-curvaton case.
  Using (non-)Gaussianity observations, Planck can be able to distinguish
between single-field inflation and curvaton model. Hence it is important to
derive theoretical predictions for curvaton model. From particle physics point
of view it is more natural to assume multiple scalar fields (rather than just
one ``curvaton'' in addition to inflaton). Our work updates the theoretical
predictions of curvaton model to this case.


title:
Observing white dwarfs orbiting massive black holes in the gravitational
  wave and electro-magnetic window

abstract:
  We consider a potentially new class of gravitational wave sources consisting
of a white dwarf coalescing into a massive black hole in the mass range
~10^4-10^5\msun. These sources are of particular interest because the
gravitational wave signal produced during the inspiral phase can be detected by
the Laser Interferometer Space Antenna (LISA) and is promptly followed, in an
extended portion of the black hole and white dwarf mass parameter space, by an
electro-magnetic signal generated by the tidal disruption of the star,
detectable with X-ray, optical and UV telescopes. This class of sources could
therefore yield a considerable number of scientific payoffs, that include
precise cosmography at low redshift, demographics of black holes in the mass
range ~10^4-10^5\Msun, insights into dynamical interactions and populations of
white dwarfs in the cores of dwarf galaxies, as well as a new probe into the
structure and equation of state of white dwarfs. By modelling the gravitational
and electromagnetic radiation produced by these events, we find them detectable
in both observational windows at a distance ~200 Mpc, and possibly beyond for
selected regions of the parameter space. We also estimate the detection rate
for a number of model assumptions about black hole and white dwarf mass
functions and dynamical interactions: the rate is (not surprisingly) highly
uncertain, ranging from ~0.01 yr^-1 to ~100 yr^-1. This is due to the current
limited theoretical understanding and minimal observational constraints for
these objects and processes. However, capture rate scaling arguments favor the
high end of the above range, making likely the detection of several events
during the LISA lifetime.


title: Detection of quiescent galaxies in a bicolor sequence from z=0-2

abstract:
  We investigate the properties of quiescent and star-forming galaxy
populations to z~2 with purely photometric data, employing a novel rest-frame
color selection technique. From the UKIDSS Ultra-Deep Survey Data Release 1,
with matched optical and mid-IR photometry taken from the Subaru XMM Deep
Survey and Spitzer Wide-Area Infrared Extragalactic Survey respectively, we
construct a K-selected galaxy catalog and calculate photometric redshifts.
Excluding stars, objects with uncertain z_phot solutions, those that fall in
bad or incomplete survey regions, and those for which reliable rest-frame
colors could not be derived, 30108 galaxies with K<22.4 (AB) and z<2.5 remain.
The galaxies in this sample are found to occupy two distinct populations in the
rest-frame U-V vs. V-J color space: a clump of red, quiescent galaxies
(analogous to the red sequence) and a track of star-forming galaxies extending
from blue to red U-V colors. This bimodal behavior is seen up to z~2. Due to a
combination of measurement errors and passive evolution, the color-color
diagram is not suitable to distinguish the galaxy bimodality at z>2 for this
sample, but we show that MIPS 24um data suggest that a significant population
of quiescent galaxies exists even at these higher redshifts. At z=1-2, the most
luminous objects in the sample are divided roughly equally between star-forming
and quiescent galaxies, while at lower redshifts most of the brightest galaxies
are quiescent. Moreover, quiescent galaxies at these redshifts are clustered
more strongly than those actively forming stars, indicating that galaxies with
early-quenched star formation may occupy more massive host dark matter halos.
This suggests that the end of star formation is associated with, and perhaps
brought about by, a mechanism related to halo mass.


title:
Deep Chandra X-ray Observations of Low Mass X-ray Binary Candidates in
  the Early-Type Galaxy NGC 4697

abstract:
  Chandra X-ray observations routinely resolve tens to hundreds of low-mass
X-ray binaries (LMXBs) per galaxy in nearby massive early-type galaxies. These
studies have raised important issues regarding the behavior of this population
of remnants of the once massive stars in early-type galaxies, namely the
connection between LMXBs and globular clusters (GCs) and the nature of the LMXB
luminosity function (LF). In this paper, we combine five epochs of Chandra
observations and one central field Hubble Space Telescope Advance Camera for
Surveys observation of NGC 4697, one of the nearest, optically luminous
elliptical (E6) galaxies, to probe the GC-LMXB connection and LMXB-LF down to a
detection/completeness limit of (0.6/1.4) x 10^{37} ergs/s. We detect 158
sources, present their luminosities and hardness ratios, and associate 34 LMXBs
with GCs. We confirm that GCs with higher encounter rates (\Gamma_h) and redder
colors (higher metallicity Z) are more likely to contain GCs, and find that the
expected number of LMXBs per GC is proportional to \Gamma_h^{0.79+0.18/-0.15}
Z^{0.50+0.20/-0.18}, consistent with fainter X-ray sources in Galactic GCs and
LMXBs in Virgo early-type galaxies. Approximately 11+/-2% / 8 +/-2% of GCs in
NGC 4697 contain an LMXB at the detection/completeness limit. We propose that
the larger proportion of metal-rich GCs in NGC 4697 compared to the Milky Way
explains why these fractions are much higher than those of the Milky Way at
similar luminosities. We confirm that a broken power-law is the best fit to the
LMXB-LF, although we cannot rule out a cutoff power-law, and argue that this
raises the possibility that there is no universal form for the LMXB-LF in
early-type galaxies. We find marginal evidence for different LFs of LMXBs in
GCs and the field and different spectra of GC-LMXBs and Field-LMXBs.


title:
Measurements of Variability of Low Mass X-ray Binary Candidates in the
  Early-Type Galaxy NGC 4697 from Multi-Epoch Chandra X-ray Observations

abstract:
  Multi-epoch Chandra X-ray observations of nearby massive early-type galaxies
open up the study of an important regime of low-mass X-ray binary (LMXB)
behavior -- long term variability. In a companion paper, we report on the
detection of 158 X-ray sources down to a detection/completeness limit of
0.6/1.4 x 10^{37} ergs/s using five Chandra observations of NGC 4697, one of
the nearest (11.3 Mpc), optically luminous (M_B < -20), elliptical (E6) galaxy.
In this paper, we report on the variability of LMXB candidates measured on
timescales from seconds to years. At timescales of seconds to hours, we detect
five sources with significant variability. Approximately 7% of sources show
variability between any two observations, and 16+/-4% of sources do not have a
constant luminosity over all five observations. Among variable sources, we
identify eleven transient candidates, with which we estimate that if all LMXBs
in NGC 4697 are long-term transients then they are on for ~ 100 yr and have a
7% duty cycle. These numbers are consistent with those found for brighter LMXBs
in M87 and NGC 1399, which suggests that there does not appear to be a
measurable difference between the outburst durations of long-term transient
neutron star LMXBs and black hole LMXBs. We discuss in detail a transient
supersoft source, whose properties are not easily explained by standard
explanations for supersoft sources.


title: Hawking radiation as seen by an infalling observer

abstract:
  We investigate an important question of Hawking-like radiation as seen by an
infalling observer during gravitational collapse. Using the functional
Schrodinger formalism we are able to probe the time dependent regime which is
out of the reach of the standard approximations like the Bogolyubov method. We
calculate the occupation number of particles whose frequencies are measured in
the proper time of an infalling observer in two crucially different space-time
foliations: Schwarzschild and Eddington-Finkelstein. We demonstrate that the
distribution in Schwarzschild reference frame is not quite thermal, though it
becomes thermal once the horizon is crossed. We approximately fit the
temperature and find that the local temperature increases as the horizon is
approached, and diverges exactly at the horizon. In Eddington-Finkelstein
reference frame the temperature at the horizon is finite, since the observer in
that frame is not accelerated. These results are in agreement with what is
generically expected in the absence of backreaction. We also discuss some
subtleties related to the physical interpretation of the infinite local
temperature in Schwarzschild reference frame.


title:
Periastron Precession Measurements in Transiting Extrasolar Planetary
  Systems at the Level of General Relativity

abstract:
  Transiting exoplanetary systems are surpassingly important among the
planetary systems since they provide the widest spectrum of information for
both the planet and the host star. If a transiting planet is on an eccentric
orbit, the duration of transits T_D is sensitive to the orientation of the
orbital ellipse relative to the line of sight. The precession of the orbit
results in a systematic variation in both the duration of individual transit
events and the observed period between successive transits, P_obs. The
periastron of the ellipse slowly precesses due to general relativity and
possibly the presence of other planets in the system. This secular precession
can be detected through the long-term change in P_obs (transit timing
variations, TTV) or in T_D (transit duration variations, TDV). We estimate the
corresponding precession measurement precision for repeated future observations
of the known eccentric transiting exoplanetary systems (XO-3b, HD 147506b, GJ
436b and HD 17156b) using existing or planned space-borne instruments. The TDV
measurement improves the precession detection sensitivity by orders of
magnitude over the TTV measurement. We find that TDV measurements over a ~4
year period can typically detect the precession rate to a precision well
exceeding the level predicted by general relativity.


title:
Observability of the General Relativistic Precession of Periastra in
  Exoplanets

abstract:
  The general relativistic precession rate of periastra in close-in exoplanets
can be orders of magnitude larger than the magnitude of the same effect for
Mercury. The realization that some of the close-in exoplanets have significant
eccentricities raises the possibility that this precession might be detectable.
We explore in this work the observability of the periastra precession using
radial velocity and transit light curve observations. Our analysis is
independent of the source of precession, which can also have significant
contributions due to additional planets and tidal deformations. We find that
precession of the periastra of the magnitude expected from general relativity
can be detectable in timescales of <~ 10 years with current observational
capabilities by measuring the change in the primary transit duration or in the
time difference between primary and secondary transits. Radial velocity curves
alone would be able to detect this precession for super-massive, close-in
exoplanets orbiting inactive stars if they have ~100 datapoints at each of two
epochs separated by ~20 years. We show that the contribution to the precession
by tidal deformations may dominate the total precession in cases where the
relativistic precession is detectable. Studies of transit durations with Kepler
might need to take into account effects arising from the general relativistic
and tidal induced precession of periastra for systems containing close-in,
eccentric exoplanets. Such studies may be able to detect additional planets
with masses comparable to that of Earth by detecting secular variations in the
transit duration induced by the changing longitude of periastron.


title: Exact universality from any entangling gate without inverses

abstract:
  This note proves that arbitrary local gates together with any entangling
bipartite gate V are universal. Previously this was known only when access to
both V and V^{-1} was given, or when approximate universality was demanded.


title: The existence problem for Steiner networks in strictly convex domains

abstract:
  We consider the existence problem for `Steiner networks' (trivalent graphs
with 120 degree angles at each junction) in strictly convex domains, with
`Neumann' boundary conditions (orthogonal intersection with the domain
boundary.) For each of the three possible combinatorial possibilities,
sufficient conditions on the domain are derived for existence; in addition, in
each case explicit examples of nonexistence are given.


title: Superdiffusion in quasi-two-dimensional Yukawa liquids

abstract:
  The emergence and vanishing of superdiffusion in quasi-two-dimensional Yukawa
systems are investigated by molecular dynamics simulations. Using both the
asymptotic behaviour of the mean-squared displacement of the particles and the
long-time tail of the velocity autocorrelation function as indicators for
superdiffusion, we confirm the existence of a transition from normal diffusion
to superdiffusion in systems changing from a three-dimensional to a
two-dimensional character. A connection between superdiffusion and
dimensionality is established by the behaviour of the projected pair
distribution function.


title: GUT Relations from String Theory Compactifications

abstract:
  Wilson line on a non-simply connected manifold is a nice way to break SU(5)
unified symmetry, and to solve the doublet--triplet splitting problem. This
mechanism also requires, however, that the two Higgs doublets are strictly
vector-like under all underlying gauge symmetries, and consequently there is a
limit in a class of modes and their phenomenology for which the Wilson line can
be used. An alternative is to turn on a non-flat line bundle in the U(1)_Y
direction on an internal manifold, which does not have to be non-simply
connected. The U(1)_Y gauge field has to remain in the massless spectrum, and
its coupling has to satisfy the GUT relation. In string theory
compactifications, however, it is not that easy to satisfy these conditions in
a natural way; we call it U(1)_Y problem. In this article, we explain how the
problem is solved in some parts of moduli space of string theory
compactifications. Two major ingredients are an extra strongly coupled U(1)
gauge field and parametrically large volume for compactification that is also
essential in accounting for the hierarchy between the Planck scale and the GUT
scale. Heterotic-M theory vacua and F-theory vacua are discussed. This article
also shows that the toroidal orbifold GUT approach using discrete Wilson lines
corresponds to the non-flat line-bundle breaking above when orbifold
singularities are blown up. Thus, the orbifold GUT approach also suffers from
the U(1)_Y problem, and this article shows how to fix it.


title: The Antinomy of the Liar and Provability

abstract:
  This work evidences that a sentence cannot be denominated by P and written as
P IS NOT TRUE. It demonstrates that in a system in which Q denominates the
sentence Q IS NOT PROVABLE it is not provable that Q is true and not provable.


title:
Asymptotically Unitary Equivalence and Classification of Simple Amenable
  C*-algebras

abstract:
  Let $C$ and $A$ be two unital separable amenable simple C*-algebras with
tracial rank no more than one. Suppose that $C$ satisfies the Universal
Coefficient Theorem and suppose that $\phi_1, \phi_2: C\to A$ are two unital
monomorphisms. We show that there is a continuous path of unitaries $\{u_t:
t\in [0, \infty)\}$ of $A$ such that $$
\lim_{t\to\infty}u_t^*\phi_1(c)u_t=\phi_2(c)\tforal c\in C $$ if and only if
$[\phi_1]=[\phi_2]$ in $KK(C,A),$ $\phi_1^{\ddag}=\phi_2^{\ddag},$
$(\phi_1)_T=(\phi_2)_T$ and a rotation related map $\bar{R}_{\phi_1,\phi_2}$
associated with $\phi_1$ and $\phi_2$ is zero.
  Applying this result together with a result of W. Winter, we give a
classification theorem for a class ${\cal A}$ of unital separable simple
amenable \CA s which is strictly larger than the class of separable \CA s whose
tracial rank are zero or one. The class contains all unital simple ASH-algebras
whose state spaces of $K_0$ are the same as the tracial state spaces as well as
the simple inductive limits of dimension drop circle algebras. Moreover it
contains some unital simple ASH-algebras whose $K_0$-groups are not Riesz. One
consequence of the main result is that all unital simple AH-algebras which are
${\cal Z}$-stable are isomorphic to ones with no dimension growth.


title: On "small geodesics" and free loop spaces

abstract:
  A topological group is constructed which is homotopy equivalent to the
pointed loop space of a path-connected Riemannian manifold $M$ and which is
given in terms of "composable small geodesics" on $M$. This model is analogous
to J. Milnor's free group construction \cite{Milnor} which provides a model for
the pointed loop space of a connected simplicial complex. Related function
spaces are constructed from "composable small geodesics" which provide models
for the free loop space of $M$ as well as the space of continuous maps from a
surface to $M$.


title: An extension of the Marsden-Ratiu reduction for Poisson manifolds

abstract:
  We propose a generalization of the reduction of Poisson manifolds by
distributions introduced by Marsden and Ratiu. Our proposal overcomes some of
the restrictions of the original procedure, and makes the reduced Poisson
structure effectively dependent on the distribution. Different applications are
discussed, as well as the algebraic interpretation of the procedure and its
formulation in terms of Dirac structures.


title:
Theory of Helimagnons in Itinerant Quantum Systems IV: Transport in the
  Weak-Disorder Regime

abstract:
  We apply a recent quasiparticle model for the electronic properties of
metallic helimagnets to calculate the transport properties of three-dimensional
systems in the helically ordered phase. We focus on the ballistic regime tau^2
T epsilon_F >> 1 at weak disorder (large elastic mean-free time tau) or
intermediate temperature. In this regime, we find a leading temperature
dependence of the electrical conductivity proportional to T. This is much
stronger than either the Fermi-liquid contribution (T^2) or the contribution
from helimagnon scattering in the clean limit (T^{5/2}). It is reminiscent of
the behavior of non-magnetic two-dimensional metals, but the sign of the effect
is opposite to that in the non-magnetic case. Experimental consequences of this
result are discussed.


title: On the Sum-Product Problem on Elliptic Curves

abstract:
  Let $\E$ be an ordinary elliptic curve over a finite field $\F_{q}$ of $q$
elements and $x(Q)$ denote the $x$-coordinate of a point $Q = (x(Q),y(Q))$ on
$\E$. Given an $\F_q$-rational point $P$ of order $T$, we show that for any
subsets $\cA, \cB$ of the unit group of the residue ring modulo $T$, at least
one of the sets $$ \{x(aP) + x(bP) : a \in \cA, b \in \cB\}
\quad\text{and}\quad \{x(abP) : a \in \cA, b \in \cB\} $$ is large. This
question is motivated by a series of recent results on the sum-product problem
over finite fields and other algebraic structures.


title:
Nuclear magnetic resonance probes for the Kondo scenario for the 0.7
  feature in semiconductor quantum point contact devices

abstract:
  We propose a probe based on nuclear relaxation and Knight shift measurements
for the Kondo scenario for the "0.7 feature" in semiconductor quantum point
contact (QPC) devices. We show that the presence of a bound electron in the QPC
would lead to a much higher rate of nuclear relaxation compared to nuclear
relaxation through exchange of spin with conduction electrons. Furthermore, we
show that the temperature dependence of this nuclear relaxation is very
non-monotonic as opposed to the linear-T relaxation from coupling with
conduction electrons. We present a qualitative analysis for the additional
relaxation due to nuclear spin diffusion (NSD) and study the extent to which
NSD affects the range of validity of our method. The conclusion is that nuclear
relaxation, in combination with Knight shift measurements, can be used to
verify whether the 0.7 feature is indeed due to the presence of a bound
electron in the QPC.


title: Thermodynamics of k-essence

abstract:
  We discuss thermodynamic properties of dark energy using the formalism of
field theory at finite temperature. In particular, we apply our formalism to a
purely kinetic type of k-essence. We show quite generally that the entropy
associated with dark-energy is always equal or greater than zero. Hence,
contrary to often stated claims, a violation of the null energy condition
(phantom dark energy) does not necessarily yield a negative entropy. In
addition, we find that the thermal fluctuations of a k-essence field may be
represented by a free boson gas with an effective number of degrees of freedom
equal to c_s^{-3}.


title: Pure Spinor Partition Function Using Pade Approximants

abstract:
  In a recent paper, the partition function (character) of ten-dimensional pure
spinor worldsheet variables was calculated explicitly up to the fifth
mass-level. In this letter, we propose a novel application of Pade approximants
as a tool for computing the character of pure spinors. We get results up to the
twelfth mass-level. This work is a first step towards an explicit construction
of the complete pure spinor partition function.


title: Di-Quarks and Tri-Quarks on the Lattice

abstract:
  The distribution of gluon fields in hadrons is of fundamental interest in
QCD. Using lattice QCD we have observed the formation of gluon flux tubes
within tri-quark (baryon) systems for a wide variety of spatial distributions
of the color sources. In particular we have investigated configurations where
two of the quarks are close together and the third quark is some distance away,
which approximates a quark plus diquark string. We find that the string tension
of the quark-diquark string is the same as that of the quark-antiquark string
on the same lattice. We also compare the longitudinal and transverse profiles
of the gluon flux tubes for both sets of strings, and find them to be of
similar radii and to have similar vacuum suppression.


title:
Hyperbolicity of the Trace Map for the Weakly Coupled Fibonacci
  Hamiltonian

abstract:
  We consider the trace map associated with the Fibonacci Hamiltonian as a
diffeomorphism on the invariant surface associated with a given coupling
constant and prove that the non-wandering set of this map is hyperbolic if the
coupling is sufficiently small. As a consequence, for these values of the
coupling constant, the local and global Hausdorff dimension and the local and
global box counting dimension of the spectrum of the Fibonacci Hamiltonian all
coincide and are smooth functions of the coupling constant.


title: Apodized Pupil Lyot Coronagraph Working Without Lyot Stop

abstract:
  In the context of high contrast imaging, we propose to evaluate the
performance of the Apodized Pupil Lyot Coronagraph (APLC) working without Lyot
Stop, namely Stop-less Lyot Coronagraph (SLLC). This coronagraph is a
combination of an entrance pupil apodizer and an opaque mask in the following
focal plane. However, contrary to APLC, SLLC is amputated by the traditional
pupil stop. Our goal is to stress the interest of using this coronagraphic
solution, in particular for instruments for which the introduction of a stellar
coronagraph with Lyot stop is made impossible. We estimate the intensity
attenuation achieved with SLLC and carry out our study with a focus on the case
of Gran Telescopio Canarias (GTC). In a first step, numerical simulations are
made assuming the absence of any aberration, thereafter SLLC performance is
evaluated considering AO corrected wavefronts in our approach for ground-based
instruments. SLLC performance proves to be equivalent to that obtained with
APLC in presence of AO compensated atmospheric turbulence images, which Strehl
ratio is S=0.552 at the wavelength lambda=1.57 mu m. This coronagraph allows to
remove the peak intensity of a star image and therefore, avoid detector
saturation. Moreover, it helps increasing the image dynamic range. A mean
contrast gain in stellar magnitudes Delta m=0.23 is obtained with SLLC whereas
APLC reaches a value Delta m=0.38.


title: Reconsidering Mermin's "In praise of measurement"

abstract:
  We critically analyze a recent paper by D. Mermin and we compare his
statements with Bell's position on the problems he is discussing.


title:
Observation of inverse diproton photodisintegration at intermediate
  energies

abstract:
  The reaction pp->{pp}_s\gamma, where {pp}_s is a proton pair with an
excitation energy E_{pp}<3 MeV, has been observed with the ANKE spectrometer at
COSY-Juelich for proton beam energies of T_p=0.353, 0.500, and 0.550 GeV. This
is equivalent to photodisintegration of a free 1S_0 diproton for photon
energies E\gamma ~ T_p/2. The differential cross sections measured for c.m.
angles 0 deg.<\theta_{pp}<20 deg. exhibit a steep increase with angle that is
compatible with E1 and E2 multipole contributions. The ratio of the measured
cross sections to those of np->d\gamma is on the 10^{-3}-10^{-2} level. The
increase of the pp->{pp}_s\gamma cross section with T_p might reflect the
influence of the Delta(1232) excitation.


title: Singular spectrum for radial trees

abstract:
  We prove several results showing that absolutely continuous spectrum for the
Laplacian on radial trees is a rare event. In particular, we show that metric
trees with unbounded edges have purely singular spectrum and that generically
(in the sense of Baire) radial trees have purely singular continuous spectrum.


title:
A Unified Catalog of Radio Objects Detected by NVSS, FIRST, WENSS, GB6,
  and SDSS

abstract:
  (Abridged) We construct a catalog of radio sources detected by the GB6 (6
cm), FIRST and NVSS (20 cm), and WENSS (92 cm) radio surveys, and the SDSS
optical survey. The 2.7 million entries in the publicly-available master
catalog are comprised of the closest three FIRST to NVSS matches (within 30
arcsec) and vice-versa, and unmatched sources from each survey. Entries are
supplemented by data from the other radio and optical surveys, where available.
We perform data analysis a ~3000 deg^2 region of sky where the surveys overlap,
which contains 140,000 NVSS-FIRST sources, of which 64,000 are detected by
WENSS and 12,000 by GB6. About one third of each sample is detected by SDSS. An
automated classification method based on 20 cm fluxes defines three radio
morphology classes: complex, resolved, and compact. Radio color-magnitude-
morphology diagrams for these classes show structure suggestive of strong
underlying physical correlations. Complex and resolved sources tend to have a
steep spectral slope (alpha ~ -0.8) that is nearly constant from 6 to 92 cm,
while the compact class contains a significant number of flat-spectrum (alpha ~
0) sources. In the optically-detected sample, quasars dominate the
flat-spectrum compact sources while steep-spectrum and resolved objects contain
substantial numbers of both quasars and galaxies. Differential radio counts of
quasars and galaxies are similar at bright flux levels (>100 mJy at 20 cm),
while at fainter levels the quasar counts are significantly reduced below
galaxy counts. The optically-undetected sample is strongly biased toward
steep-spectrum sources. In samples of quasars and galaxies with SDSS spectra,
we find that radio properties such as spectral slope, morphology, and radio
loudness are correlated with optical color and luminosity.


title: Linearization of the inverse conductivity problem

abstract:
  A positive function (conductivity) on the edges of a graph induces the
Dirichlet-to- Neumann map between boundary values of harmonic functions. The
inverse conductivity problem is to find the conductivity from the
Dirichlet-to-Neumann map. We will show that the map from logarithm of
conductivity to the certain logarithms of the determinants of the submatrices
of the Dirichlet-to-Neumann map is linear(!) and so the solution of the inverse
problem is reduced to solution of the system of linear equations that arise
from disjoint paths in the graph. We will make a calculation for a simple
tensor product lattice graph and conjecture that it generalizes to planar and
three dimensional graphs and also to the continuous case. Depending on the
graph the algorithm resembles or not the layer-stripping.


title: Bohr's atomic model revisited

abstract:
  Bohr's atomic model, its relationship to the radiation spectrum of the
hydrogen atom and the inherent hypotheses are revisited. It is argued that Bohr
could have adopted a different approach, focusing his analyzes on the
stationary orbit of the electron and its decomposition on two harmonic
oscillators and then imposing, as actually he did, Planck's quantization for
the oscillators' energies. Some consequences of this procedure are examined.


title: The Square of the Dirichlet-to-Neumann map equals minus Laplacian

abstract:
  The Dirichlet-to-Neumann maps connect boundary values of harmonic functions.
It is an amazing fact that the square of the non-local Dirichlet-to-Neumann map
for the uniform conductivity 1 on the unit disc equals minus the local(!)
Laplace operator on the boundary circle. To establish a new connection between
discrete and continuous Dirichlet-to-Neumann maps and for the approximations I
construct a finite and an infinite graphs which Dirichlet-to-Neumann map have
the same property: \Lambda^2(1) = - d^2/d \theta^2. The construction gives a
new continued fraction identity. It is interesting to consider the geometric
and probabilistic (trajectories of the random walk) consequences of this
localizing identity unifying discrete and continuous equations for potentials.


title: Efficient Toffoli Gates Using Qudits

abstract:
  The simplest decomposition of a Toffoli gate acting on three qubits requires
{\em five} 2-qubit gates. If we restrict ourselves to controlled-sign (or
controlled-NOT) gates this number climbs to six. We show that the number of
controlled-sign gates required to implement a Toffoli gate can be reduced to
just {\em three} if one of the three quantum systems has a third state that is
accessible during the computation, i.e. is actually a qutrit. Such a
requirement is not unreasonable or even atypical since we often artificially
enforce a qubit structure on multilevel quantums systems (eg. atoms, photonic
polarization and spatial modes). We explore the implementation of these
techniques in optical quantum processing and show that linear optical circuits
could operate with much higher probabilities of success.


title: Spectrum of analytic continuation

abstract:
  I will show that operator of analytic (harmonic) continuation on a lattice
graph has a positive spectrum. I use a theorem about positivity of eigenvalues
of totally positive matrices. I conjecture that by approximation the similar
result holds in continuous case on a plane.


title:
Non-linear realization of Poincare invariance in the
  graph-representation of extremal hypersurfaces

abstract:
  In the Born-Infeld 'harmonic gauge' description of M-branes moving in R^{M+1}
the underlying M+2 dimensional Poincare - invariance gives rise to an
interesting system of conservation laws showing signs of integrability.


title: Spectroscopic Confirmation Of An Extreme Starburst At Redshift 4.547

abstract:
  We report the spectroscopic confirmation of a sub-mm galaxy (SMG) at z=4.547
with an estimated L_IR=0.5-2.0x10^13 L_sun. The spectra, mid-IR, and X-ray
properties indicate the bolometric luminosity is dominated by star formation at
a rate of >1000M_sun per yr. Multiple, spatially separated components are
visible in the Ly-Alpha line with an observed velocity difference of up to 380
km/sec and the object morphology indicates a merger. The best fit spectral
energy distribution and spectral line indicators suggest the object is 2-8 Myr
old and contains >10^10 M_sun of stellar mass. This object is a likely
progenitor for the massive early type systems seen at z~2.


title: The generalized Cassels-Tate dual exact sequence for 1-motives

abstract:
  We establish a generalized Cassels-Tate dual exact sequence for 1-motives
over global fields. We thereby extend the main theorem of [4] from abelian
varieties to arbitrary 1-motives.


title:
Amplification and squeezing of quantum noise with a tunable Josephson
  metamaterial

abstract:
  It has recently become possible to encode the quantum state of
superconducting qubits and the position of nanomechanical oscillators into the
states of microwave fields. However, to make an ideal measurement of the state
of a qubit, or to detect the position of a mechanical oscillator with
quantum-limited sensitivity requires an amplifier that adds no noise. If an
amplifier adds less than half a quantum of noise, it can also squeeze the
quantum noise of the electromagnetic vacuum. Highly squeezed states of the
vacuum serve as an important quantum information resource. They can be used to
generate entanglement or to realize back-action-evading measurements of
position. Here we introduce a general purpose parametric device, which operates
in a frequency band between 4 and 8 GHz. It is a subquantum-limited microwave
amplifier, it amplifies quantum noise above the added noise of commercial
amplifiers, and it squeezes quantum fluctuations by 10 dB.


title: Lorentz-Covariant Non-Abelian Gauging of Supermembrane

abstract:
  We perform the Lorentz-covariant non-Abelian gauging of supermembrane (M-2
brane) action. This is a generalization of our previous work based on
teleparallel formulation, in which Lorentz covariance was not manifest. We
introduce the Killing supervector \xi^{A I} with the adjoint index I for a
non-Abelian gauge group H. This formulation is applicable to the
compactification of supermembrane from eleven dimensions into D dimensions,
such as H = SO(11-D) for the compactification M_{11} \to S^{11-D} \times M_D
(1\le D \le 9).


title: Computing a Generating Set of Arithmetic Kleinian Groups

abstract:
  The goal of this paper is to demonstrate the use of techniques from
hyperbolic geometry to compute generating sets of certain subgroups of
$SL^+(2,\mathbb{C})$; specifically, $SO^+(Q,\mathbb{Z})$ for $Q$ some integral
quadratic form of signature $(3,1)$ that does not represent 0. The algorithm is
illustrated for the form $Q_7=x_1^2+x_2^2+x_3-7x^4$, and explicit generating
matrices are found.


title:
Linked evolution of gas and star formation in galaxies over cosmic
  history

abstract:
  We compare the cosmic evolution of star formation rates in galaxies with that
of their neutral hydrogen densities. We highlight the need for neutral hydrogen
to be continually replenished from a reservoir of ionized gas to maintain the
observed star formation rates in galaxies. Hydrodynamic simulations indicate
that the replenishment may occur naturally through gas infall, although
measured rates of gas infall in nearby galaxies are insufficient to match
consumption. We identify an alternative mechanism for this replenishment,
associated with expanding supershells within galaxies. Pre-existing ionized gas
can cool and recombine efficiently in the walls of supershells, molecular gas
can form in situ in shell walls, and shells can compress pre-existing molecular
clouds to trigger collapse and star formation. We show that this mechanism
provides replenishment rates sufficient to maintain both the observed HI mass
density and the inferred molecular gas mass density over the redshift range
0<z<5.


title:
Controlling atomic vapor density in paraffin-coated cells using
  light-induced atomic desorption

abstract:
  Atomic-vapor density change due to light induced atomic desorption (LIAD) is
studied in paraffin-coated rubidium, cesium, sodium and potassium cells. In the
present experiment, low-intensity probe light is used to obtain an absorption
spectrum and measure the vapor density, while light from an argon-ion laser,
array of light emitting diodes, or discharge lamp is used for desorption.
Potassium is found to exhibit significantly weaker LIAD from paraffin compared
to Rb and Cs, and we were unable to observe LIAD with sodium. A simple LIAD
model is applied to describe the observed vapor-density dynamics, and the role
of the cell's stem is explored through the use of cells with lockable stems.
Stabilization of Cs vapor density above its equilibrium value over 25 minutes
is demonstrated. The results of this work could be used to assess the use of
LIAD for vapor-density control in magnetometers, clocks, and gyroscopes
utilizing coated cells.


title:
Classical analysis of the rotational dynamic of spiral galaxies: Quo
  Vadis Dark Matter?

abstract:
  In this paper we study a stellar dynamic model for the stars'
rotational-dynamics, with a distribution of its own mass, rotating around its
center with a higher density, like spiral galaxies happen, by means of a
classical calculus of the rotation velocities of a particle around its
rotational axis, inside a smoothed distribution of matter. The stars are
supposed to be particles and their distribution in the galaxy is modelled as a
matter distribution inversely proportional to its distance from its center. Two
kinds of matter distribution are supposed: one with constant density, and other
with radial distribution. Two types of galaxy symmetry are also considered:
spherical and oblate ellipsoidal. Using only classical mechanics arguments it
is shown that the calculated velocity distribution inside the galaxy is similar
to that obtained from astronomical observations, without the necessity of
suppose the existence of dark matter or other phenomena.


title: Indeterminacy of Holographic Quantum Geometry

abstract:
  An effective theory based on wave optics is used to describe indeterminacy of
position in holographic spacetime with a UV cutoff at the Planck scale.
Wavefunctions describing spacetime positions are modeled as complex
disturbances of quasi-monochromatic radiation. It is shown that the product of
standard deviations of two position wavefunctions in the plane of a holographic
light sheet is equal to the product of their normal separation and the Planck
length. For macroscopically separated positions the transverse uncertainty is
much larger than the Planck length, and is predicted to be observable as a
"holographic noise" in relative position with a distinctive shear spatial
character, and an absolutely normalized frequency spectrum with no parameters
once the fundamental wavelength is fixed from the theory of gravitational
thermodynamics. The spectrum of holographic noise is estimated for the GEO600
interferometric gravitational-wave detector, and is shown to approximately
account for currently unexplained noise between about 300 and 1400Hz. In a
holographic world, this result directly and precisely measures the fundamental
minimum interval of time.


title: (2+2)-free posets, ascent sequences and pattern avoiding permutations

abstract:
  We present bijections between four classes of combinatorial objects. Two of
them, the class of unlabeled (2+2)-free posets and a certain class of
involutions (or chord diagrams), already appeared in the literature, but were
apparently not known to be equinumerous. We present a direct bijection between
them. The third class is a family of permutations defined in terms of a new
type of pattern. An attractive property of these patterns is that, like
classical patterns, they are closed under the action of $D_8$, the symmetry
group of the square. The fourth class is formed by certain integer sequences,
called ascent sequences, which have a simple recursive structure and are shown
to encode (2+2)-free posets and permutations. Our bijections preserve numerous
statistics.
  We determine the generating function of these classes of objects, thus
recovering a non-D-finite series obtained by Zagier for the class of chord
diagrams. Finally, we characterize the ascent sequences that correspond to
permutations avoiding the barred pattern $3{\bar 1}52{\bar 4}$ and use this to
enumerate those permutations, thereby settling a conjecture of Pudwell.


title:
Testing Realistic Quark Mass Matrices in the Custodial Randall-Sundrum
  Model with Flavor Changing Top Decays

abstract:
  We study quark mass matrices in the Randall-Sundrum (RS) model with bulk
symmetry $SU(2)_L \times SU(2)_R \times U(1)_{B-L}$. The Yukawa couplings are
assumed to be within an order of magnitude of each other, and perturbative. We
find that quark mass matrices of the symmetrical form proposed by Koide
\textit{et. al.} [Y. Koide, H. Nishiura, K. Matsuda, T. Kikuchi and T.
Fukuyama, Phys. Rev. D {\bf 66}, 093006 (2002)] can be accommodated in the RS
framework with the assumption of hierarchyless Yukawa couplings, but not the
hermitian Fritzsch-type mass matrices. General asymmetrical mass matrices are
also found which fit well simultaneously with the quark masses and the
Cabibbo-Kobayashi-Maskawa matrix. Both left-handed (LH) and right-handed (RH)
quark rotation matrices are obtained that allow analysis of flavour changing
decay of both LH and RH top quarks. At a warped down scale of 1.65 TeV, the
total branching ratio of $t \ra Z$ + jets can be as high as $\sim 5 \times
10^{-6}$ for symmetrical mass matrices and $\sim 2 \times 10^{-5}$ for
asymmetrical ones. This level of signal is within reach of the LHC.


title: Planar scattering amplitudes from Wilson loops

abstract:
  We derive an expression for parton scattering amplitudes of planar gauge
theory in terms of sums of Wilson loops. We study in detail the example of
Yang-Mills theory with an adjoint Higgs field. The expression exhibits the
T-duality performed by Alday and Maldacena in the AdS dual as a Fourier
transform in loop space. When combined with the AdS/CFT correspondence for
Wilson loops and a strong coupling argument for the dominance of 1PI diagrams,
this leads to a derivation of the Alday-Maldacena holographic prescription for
scattering amplitudes in terms of momentum Wilson loops. The formula leads to a
conjecture for a relationship between position-space and momentum-space Wilson
loops in N=4 SYM at finite coupling.


title:
On the asymptotic spectrum of the reduced volume in cosmological
  solutions of the Einstein equations

abstract:
  Say S is a compact three-manifold with non-positive Yamabe invariant. We
prove that in any long time constant mean curvature Einstein flow over S,
having bounded C^{\alpha} space-time curvature at the cosmological scale, the
reduced volume (-k/3)^{3}Vol(g(k)) (g(k) is the evolving spatial three-metric
and k the mean curvature) decays monotonically towards the volume value of the
geometrization in which the cosmologically normalized flow decays. In more
basic terms, under the given assumptions, there is volume collapse in the
regions where the injectivity radius collapses (i.e. tends to zero) in the long
time. We conjecture that under the curvature assumption above the Thurston
geometrization is the unique global attractor. We validate it in some special
cases.


title:
Unified parametrization of quark and lepton mixing matrices in
  tri-bimaximal pattern

abstract:
  Parametrization of the quark and lepton mixing matrices is the first attempt
to understand the mixing of fermions. In this work, we parameterize the quark
and lepton matrices with the help of quark-lepton complementarity (QLC) in a
tri-bimaximal pattern of lepton mixing matrix. In this way, we combine the
parametrization of the two matrices with each other. We apply this new
parametrization to several physical quantities, and show its simplicity in the
expression of, e.g., the Jarlskog parameter of CP violation.


title: Observation of J/psi --> 3 gamma

abstract:
  We report the first observation of the decay J/psi --> 3 gamma. The signal
has a statistical significance of 6 sigma and corresponds to a branching
fraction of B(J/psi --> 3 gamma) = (1.2 +- 0.3 +- 0.2) x 10^-5, in which the
errors are statistical and systematic, respectively. The measurement uses
psi(2S) --> pi+ pi- J/psi events acquired with the CLEO-c detector operating at
the CESR e+e- collider.


title:
Particle Multiplicities in Nuclear Collisions at the LHC from Saturation
  Physics

abstract:
  The inclusion of running coupling effects in the BK-JIMWLK evolution
equations considerably reduces the energy dependence of the saturation scale
with respect to previous estimates based on fits to HERA data. We discuss how
such slowdown affects the expectations for particle multiplicities in Pb-Pb
collisions at LHC energies. Our prediction is based on the use of
k_t-factorization and on the use of unintegrated gluon distributions taken from
the numerical solutions of the BK equation with running coupling. We obtain a
central value dN/d\eta(sqrt{s}=5.5 TeV)(\eta=0)~1390.


title: Ricci Dark Energy in Brans-Dicke theory

abstract:
  A holographic dark energy from Ricci scalar curvature called Ricci dark
energy was proposed recently. In this model the future event horizon area is
replaced by the inverse of the Ricci scalar curvature. We study the evolution
of equation of state of the Ricci dark energy and the transition from
decelerated to accelerated expansion of the universe in the Brans-Dicke theory,
which is a natural extension of general relativity. We find that the current
acceleration of our universe is well explained.


title:
Simply branched covers of an elliptic curve and the moduli space of
  curves

abstract:
  Consider genus g curves that admit degree d covers to an elliptic curve
simply branched at 2g-2 points. Vary a branch point and the locus of such
covers forms a one-parameter family W. We investigate the geometry of W by
using admissible covers to study its slope, genus and components. The results
can also be applied to study slopes of effective divisors on the moduli space
of genus g curves.


title:
Phenomenological Model and Phase Behavior of Saturated and Unsaturated
  Lipids and Cholesterol

abstract:
  We present a phenomenological theory for the phase behavior of ternary
mixtures of cholesterol and saturated and unsaturated lipids, one which
describes both liquid and gel phases, and illuminates the mechanism of the
behavior. In a binary system of the lipids, the two phase separate when the
saturated chains are well ordered, as in the gel phase, simply due to packing
effects. In the liquid phase the saturated ones are not sufficiently well
ordered for separation to occur. The addition of cholesterol, however,
increases the saturated lipid order to the point that phase separation is once
again favorable. For the system above the main chain transition of the
saturated lipid, we can obtain phase diagrams in which there is liquid-liquid
phase separation in the ternary system but not in any of the binary ones, while
below that temperature we obtain the more common phase diagram in which a gel
phase, rich in saturated lipid, appears in addition to the two liquid phases.


title:
On Peak versus Average Interference Power Constraints for Protecting
  Primary Users in Cognitive Radio Networks

abstract:
  This paper considers spectrum sharing for wireless communication between a
cognitive radio (CR) link and a primary radio (PR) link. It is assumed that the
CR protects the PR transmission by applying the so-called
interference-temperature constraint, whereby the CR is allowed to transmit
regardless of the PR's on/off status provided that the resultant interference
power level at the PR receiver is kept below some predefined threshold. For the
fading PR and CR channels, the interference-power constraint at the PR receiver
is usually one of the following two types: One is to regulate the average
interference power (AIP) over all the fading states, while the other is to
limit the peak interference power (PIP) at each fading state. From the CR's
perspective, given the same average and peak power threshold, the AIP
constraint is more favorable than the PIP counterpart because of its more
flexibility for dynamically allocating transmit powers over the fading states.
On the contrary, from the perspective of protecting the PR, the more
restrictive PIP constraint appears at a first glance to be a better option than
the AIP. Some surprisingly, this paper shows that in terms of various forms of
capacity limits achievable for the PR fading channel, e.g., the ergodic and
outage capacities, the AIP constraint is also superior over the PIP. This
result is based upon an interesting interference diversity phenomenon, i.e.,
randomized interference powers over the fading states in the AIP case are more
advantageous over deterministic ones in the PIP case for minimizing the
resultant PR capacity losses. Therefore, the AIP constraint results in larger
fading channel capacities than the PIP for both the CR and PR transmissions.


title: Topological degeneracy and decoherence-protected qubits in circuit QED

abstract:
  We introduce an extended Dicke model with controllable long-range atom-atom
interaction to simulate topologically ordered states and achieve
decoherence-protected qubits. We illustrate our idea in an experimentally
feasible circuit quantum electrodynamics scenario. Due to the intrinsic
competition with the atom-field coupling strength, we first demonstrate that
this atom-atom interaction can exhibit a novel topological quantum interference
effect arising from the instanton and anti-instanton tunneling paths. As a
consequence, this proposed model only with a few odd-number of atoms has a
two-fold absolute degenerate ground-subspace with a large energy gap, which can
become larger with the increasing of the system-size. It may also support the
excitation of anyonic statistics, and thus can be regarded as a possible
candidate for processing topological quantum memory.


title:
On the behavior of quasi-local mass at the infinity along nearly round
  surfaces

abstract:
  In this paper, we study the limiting behavior of the Brown-York mass and
Hawking mass along nearly round surfaces at infinity of an asymptotically flat
manifold. Nearly round surfaces can be defined in an intrinsic way. Our results
show that the ADM mass of an asymptotically flat 3-manifold can be approximated
by some geometric invariants of a family of nearly round surfaces which
approach to infinity of the manifold.


title: Thin accretion disks in f(R) modified gravity models

abstract:
  We consider the basic physical properties of matter forming a thin accretion
disc in the static and spherically symmetric space-time metric of the vacuum
$f(R)$ modified gravity models. The Lagrangian of the generalized gravity
theory is also obtained in a parametric form, and the conditions of the
viability of the model are discussed. The exact Schwarzschild type solution of
the gravitational field equations in the $f(R)$ gravity contains a linearly
increasing term, as well as a logarithmic correction, as compared to the
standard Schwarzschild solution of general relativity, and it depends on four
arbitrary integration constants. The energy flux and the emission spectrum from
the accretion disk around the $f(R)$ gravity black holes are obtained, and they
are compared to the general relativistic case. Particular signatures can appear
in the electromagnetic spectrum, thus leading to the possibility of directly
testing modified gravity models by using astrophysical observations of the
emission spectra from accretion disks.


title: The equivariant Euler characteristic of real Coxeter toric varieties

abstract:
  Let $W$ be a Weyl group, and let $\CT_W$ be the complex toric variety
attached to the fan of cones corresponding to the reflecting hyperplanes of
$W$, and its weight lattice. The real locus $\CT_W(\R)$ is a smooth, connected,
compact manifold with a $W$-action. We give a formula for the equivariant Euler
characteristic of $\CT_W(\R)$ as a generalised character of $W$. In type
$A_{n-1}$ for $n$ odd, one obtains a generalised character of $\Sym_n$ whose
degree is (up to sign) the $n^{\text{th}}$ Euler number.


title: Automorphisms of polynomial algebras and Dirichlet series

abstract:
  Let GF(q)[x,y] be the polynomial algebra in two variables over the finite
field GF(q) with q elements. We give an exact formula and the asymptotics for
the number p(n) of automorphisms (f,g) of GF(q)[x,y] such that
max{deg(f),deg(g)}=n. We describe also the Dirichlet series generating function
p(1)/1^s+p(2)/2^s+p(3)/3^s+.... The same results hold for the automorphisms of
the free associative algebra GF(q)<x,y>. We have also obtained analogues for
free algebras with two generators in Nielsen - Schreier varieties of algebras.


title: On Phantom Thermodynamics

abstract:
  The thermodynamic properties of dark energy fluids described by an equation
of state parameter $\omega=p/\rho$ are rediscussed in the context of FRW type
geometries. Contrarily to previous claims, it is argued here that the phantom
regime $\omega<-1$ is not physically possible since that both the temperature
and the entropy of every physical fluids must be always positive definite. This
means that one cannot appeal to negative temperature in order to save the
phantom dark energy hypothesis as has been recently done in the literature.
Such a result remains true as long as the chemical potential is zero. However,
if the phantom fluid is endowed with a non-null chemical potential, the phantom
field hypothesis becomes thermodynamically consistent, that is, there are
macroscopic equilibrium states with $T>0$ and $S>0$ in the course of the
Universe expansion. Further, the negative value of the chemical potential
resulting from the entropy constraint ($S>0$) suggests a bosonic massless
nature to the phantom particles.


title: $\phi^2$ as Dark Matter

abstract:
  In this paper we consider $\phi^2$ scalar field potential as a candidate to
dark matter. If it is an ultralight boson particle, it condensates like a
Bose-Einstein system at very early times and forms the basic structure of the
Universe. Real scalar fields collapse in equilibrium configurations that
oscillate in space-time (oscillatons).The cosmological behavior of the field
equations are solved using the dynamical system formalism. We use the current
cosmological parameters as constraints for the present value of the scalar
field. We reproduce the cosmological predictions of the standard $\Lambda$CDM
model with this model. Therefore, scalar field dark matter seems to be a good
alternative to cold dark matter nature.


title:
A note on space dimensionality constraints relied on Anthropic
  arguments: methane structure and the origin of life

abstract:
  A general sketch of how the problem of space dimensionality depends on
Anthropic arguments is presented. A new argument in favor of a stable scenario
for space dimensionality for a time scale longer than that required for the
existence of human or another kind of highly-evolved life on Earth is proposed.


title: Geometries from Young Diagrams

abstract:
  Type IIB string theory on spacetimes that are asymptotically
AdS$_5\times$S$^5$ can be defined using four dimensional ${\cal N}=4$ super
Yang-Mills theory. Six of the dimensions of the string theory are
holographically reconstructed in the Yang-Mills theory. In this article we
study how these dimensions and local physics in these dimensions emerge. We
reorganize the dynamics of the ${1\over 2}$ BPS sector of the field theory by
rewriting it in terms of Schur polynomials. The Young diagram labeling of these
polynomials can be viewed as a book keeping device which summarizes how the
operator is constructed. We show that aspects of the geometry of the extra
holographic dimensions are captured very naturally by the Young diagram.
Gravitons which are localized at a specific position in the bulk correspond to
boxes added at a specific location on the Young diagram.


title: Matrix formulation of superspace on 1D lattice with two supercharges

abstract:
  Following the approach developed by some of the authors in recent papers and
using a matrix representation for the superfields, we formulate an exact
supersymmetric theory with two supercharges on a one dimensional lattice. In
the superfield formalism supersymmetry transformations are uniquely defined and
do not suffer of the ambiguities recently pointed out by some authors. The
action can be written in a unique way and it is invariant under all
supercharges. A modified Leibniz rule applies when supercharges act on a
superfield product and the corresponding Ward identities take a modified form
but hold exactly at least at the tree level, while their validity in presence
of radiative corrections is still an open problem and is not considered here.


title: A Temperley-Lieb analogue for the BMW algebra

abstract:
  The Temperley-Lieb algebra may be thought of as a quotient of the Hecke
algebra of type A, acting on tensor space as the commutant of the usual action
of quantum sl(2) on the n-th tensor power of the 2-dimensional irreducible
module. We define and study a quotient of the Birman-Wenzl-Murakami algebra,
which plays an analogous role for the 3-dimensional representation of quantum
sl(2). In the course of the discussion we prove some general results about the
radical of a cellular algebra, which may be of independent interest.


title: Correlation between structure and conductivity of stretched Nafion

abstract:
  We have used coarse-grained simulation methods to investigate the effect of
stretching-induced structure orientation on the proton conductivity of
Nafion-like polyelectrolyte membranes. Recent experimental data on the
morphology of ionomers describe Nafion as an aggregation of polymeric backbone
chains forming elongated objects embedded in a continuous ionic medium.
Uniaxial stretching of a recast Nafion film causes a preferential orientation
of these objects in the direction of stretching. Our simulations of humid
Nafion show that this has a strong effect on the proton conductivity, which is
enhanced along the stretching direction, while the conductivity perpendicular
to the stretched polymer backbone is reduced. Stretching also causes the
perfluorinated side chains to orient perpendicular to the stretching axis.
  This in turn affects the distribution of water at low water contents. The
water forms a continuous network with narrow bridges between small water
clusters absorbed in head-group multiplets.


title:
Directional Cross Diamond Search Algorithm for Fast Block Motion
  Estimation

abstract:
  In block-matching motion estimation (BMME), the search patterns have a
significant impact on the algorithm's performance, both the search speed and
the search quality. The search pattern should be designed to fit the motion
vector probability (MVP) distribution characteristics of the real-world
sequences. In this paper, we build a directional model of MVP distribution to
describe the directional-center-biased characteristic of the MVP distribution
and the directional characteristics of the conditional MVP distribution more
exactly based on the detailed statistical data of motion vectors of eighteen
popular sequences. Three directional search patterns are firstly designed by
utilizing the directional characteristics and they are the smallest search
patterns among the popular ones. A new algorithm is proposed using the
horizontal cross search pattern as the initial step and the horizontal/vertical
diamond search pattern as the subsequent step for the fast BMME, which is
called the directional cross diamond search (DCDS) algorithm. The DCDS
algorithm can obtain the motion vector with fewer search points than CDS, DS or
HEXBS while maintaining the similar or even better search quality. The gain on
speedup of DCDS over CDS or DS can be up to 54.9%. The simulation results show
that DCDS is efficient, effective and robust, and it can always give the faster
search speed on different sequences than other fast block-matching algorithm in
common use.


title: Phase Transitions, Chaos and Joint Action in the Life Space Foam

abstract:
  This paper extends our recently developed Life Space Foam (LSF) model of
motivated cognitive dynamics \cite{IA}. LSF uses adaptive path integrals to
generate Lewinian force--fields on smooth manifolds, in order to characterize
the dynamics of individual goal--directed action. According to explanatory
theories growing in acceptance in cognitive neuroscience, one of the key
properties of this dynamics, capable of linking it to microscopic-level
cortical neurodynamics, is its meta-stability and the resulting phase
transitions. Our extended LSF model incorporates the notion of phase
transitions and complements it with embedded geometrical chaos. To describe
this LSF phase transition, a general path--integral is used, along the
corresponding LSF topology change. As a result, our extended LSF model is able
to rigorously represent co-action by two or more actors in the common
LSF--manifold. The model yields substantial qualitative differences in
geometrical properties between bilateral and multi-lateral co-action due to
intrinsic chaotic coupling between $n$ actors when $n\geq 3$.
  Keywords: cognitive dynamics, adaptive path integrals, phase transitions,
chaos, topology change, human joint action, function approximation


title:
Ricci Flow and Entropy Model for Avascular Tumor Growth and Decay
  Control

abstract:
  Prediction and control of cancer invasion is a vital problem in medical
science. This paper proposes a modern geometric Ricci-flow and entropy based
model for control of avascular multicellular tumor spheroid growth and decay.
As a tumor growth/decay control tool, a monoclonal antibody therapy is
proposed.
  Keywords: avascular tumor growth and decay, multicellular tumor spheroid,
Ricci flow and entropy, nonlinear heat equation, monoclonal antibody cancer
therapy


title: Spin and Flavor Strange Quark Content of the Nucleon

abstract:
  Several spin and flavor dependent parameters characterizing the strangeness
content of the nucleon have been calculated in the chiral constituent quark
model with configuration mixing (\chiCQM_{config}) which is known to provide a
satisfactory explanation of the ``proton spin crisis'' and related issues. In
particular, we have calculated the strange spin polarization \Delta s, the
strangeness contribution to the weak axial vector couplings \Delta_8 etc.,
strangeness contribution to the magnetic moments \mu(p)^s etc., the strange
quark flavor fraction f_s, the strangeness dependent quark flavor ratios
\frac{2 \bar s}{u+d} and \frac{2 \bar s}{\bar u+ \bar d} etc.. Our results are
consistent with the recent experimental observations.


title:
Infinite-dimensionality of the Automorphism Groups of Homogeneous Stein
  Manifolds

abstract:
  We show that the group of holomorphic automorphisms of a Stein manifold X of
dimension greater than 1 is infinite-dimensional, provided X is a homogeneous
space of a holomorphic action of a complex Lie group.


title:
Two-particle bound states and one-particle structure factor in a
  Heisenberg bilayer system

abstract:
  The S=1/2 Heisenberg bilayer spin model at zero temperature is studied in the
dimerized phase using analytic triplet-wave expansions and dimer series
expansions. The occurrence of two-triplon bound states in the S=0 and S=1
channels, and antibound states in the S=2 channel, is predicted by the
triplet-wave theory, and confirmed by series expansions. All bound states are
found to vanish at or before the critical coupling separating the dimerized
phase from the Neel phase. The critical behaviour of the total and
single-particle static transverse structure factors is also studied by series,
and found to conform with theoretical expectations. The single-particle state
dominates the structure factor at all couplings.


title: Prospects for AGN studies with ALMA

abstract:
  These lecture notes provide an introduction to mm/submm extragalactic
astronomy, focused on AGN studies, with the final goal of preparing students to
their future exploitation of the ALMA capabilities. I first provide an overview
of the current results obtained through mm/submm observations of galaxies and
AGNs, both local and at high redshift. Then I summarize the main mm/submm
facilities that are currently available. ALMA is then presented with a general
description and by providing some details on its observing capabilities.
Finally, I discuss some of the scientific goals that will be achievable with
ALMA in extragalactic astronomy, and for AGN studies in particular.


title: Staggered t-structures on toric varieties

abstract:
  Achar has recently introduced a family of t-structures on the derived
category of equivariant coherent sheaves on a $G$-scheme, generalizing the
perverse coherent t-structures of Bezrukavnikov and Deligne. They are called
\emph{staggered} t-structures, and their main point of interest so far is that
they are more often self-dual. In this paper we investigate these t-structures
on the $T$-equivariant derived category of a toric variety.


title:
Non-cuspidality outside the middle degree of l-adic cohomology of the
  Lubin-Tate tower

abstract:
  In this article, we consider the representations of the general linear group
over a non-archimedean local field obtained from the vanishing cycle cohomology
of the Lubin-Tate tower. We give an easy and direct proof of the fact that no
supercuspidal representation appears as a subquotient of such representations
unless they are obtained from the cohomology of the middle degree. Our proof is
purely local and does not require Shimura varieties.


title: Maximise global gain in the minority game

abstract:
  We find a simple, partially altruistic mechanism that can increase global
gain for a community of selfish agents. The mechanism is implied in the
phenomena found in the minority game. We apply the mechanism to a two-road
traffic system to maximise traffic flow.


title: Principles of statistical physics: the energy duality

abstract:
  We argue that statistical mechanics of systems with relaxation implies
breaking the energy function of systems into two having different
transformation rules. With this duality the energy approach incorporates the
generalized vortex forces. We show general theorems and their implications and
apply the approach to the particle confinement in fields of rotational
symmetry. Misconceptions of extensive use of the quasienergy and generalized
thermodynamic potential theories are exposed.


title:
Nonlocal field theory driven by a deformed product. Generalization of
  Kalb-Ramond duality

abstract:
  A modification of the standard product used in local field theory by means of
an associative deformed product is proposed. We present a class of deformed
products, one for every spin S=0,1/2,1, that induces a nonlocal theory,
displaying different form for different fields. This type of deformed product
is naturally supersymmetric and it has an intriguing duality.


title: Number of connected spanning subgraphs on the Sierpinski gasket

abstract:
  We study the number of connected spanning subgraphs $f_{d,b}(n)$ on the
generalized Sierpinski gasket $SG_{d,b}(n)$ at stage $n$ with dimension $d$
equal to two, three and four for $b=2$, and layer $b$ equal to three and four
for $d=2$. The upper and lower bounds for the asymptotic growth constant,
defined as $z_{SG_{d,b}}=\lim_{v \to \infty} \ln f_{d,b}(n)/v$ where $v$ is the
number of vertices, on $SG_{2,b}(n)$ with $b=2,3,4$ are derived in terms of the
results at a certain stage. The numerical values of $z_{SG_{d,b}}$ are
obtained.


title:
A Small Step on the Long Road to Understanding the R-Stars: CNO Cycling
  in Candidate R-Star Progenitors

abstract:
  Recent work has proposed that a merger event between a red-giant and a He
white dwarf may be responsible for the production of R-stars (Izzard et al,
2007). We investigate the proposed evolution and nucleosynthesis of such a
model. We simulate the hypothesized late ignition of the core flash by
increasing the neutrino losses until the ignition occurs sufficiently far from
the centre that the subsequent evolution produces dredge-up of carbon to the
extent that the post-flash object is a carbon star. Detailed nucleosynthesis is
performed within this approximation, and we show that the overall properties
are broadly consistent with the observations. Details will depend on the
dynamics of the merger event.


title: Our Knowledge of High-Mass Star Formation at the Dawn of Herschel

abstract:
  We review the theories and observations of high-mass star formation
emphasizing the differences with those of low-mass star formation. We hereafter
describe the progress expected to be achieved with Herschel, thanks notably to
Key Programmes dedicated to the earliest phases of high-mass star formation.


title:
Coupling and Level Repulsion in the Localized Regime: From Isolated to
  Quasi-Extended Modes

abstract:
  We study the interaction of Anderson localized states in an open 1D random
system by varying the internal structure of the sample. As the frequencies of
two states come close, they are transformed into multiply-peaked quasi-extended
modes. Level repulsion is observed experimentally and explained within a model
of coupled resonators. The spectral and spatial evolution of the coupled modes
is described in terms of the coupling coefficient and Q-factors of resonators.


title:
Synchronization Engineering: Theoretical Framework and Application to
  Dynamical Clustering

abstract:
  A method for engineering the behavior of populations of rhythmic elements is
presented. The framework, which is based on phase models, allows a nonlinear
time-delayed global feedback signal to be constructed which produces an
interaction function corresponding to the desired behavior of the system. It is
shown theoretically and confirmed in numerical simulations that a polynomial,
delayed feedback is a versatile tool to tune synchronization patterns.
Dynamical states consisting of one to four clusters were engineered to
demonstrate the application of synchronization engineering in an experimental
electrochemical system.

categories: nlin.AO cond-mat.dis-nn nlin.PS physics.chem-ph


title: An astrophysical peek into Einstein's static universe

abstract:
  We derive here the metric for Einstein's static universe (ESU) directly from
Einstein equation, i.e., by considering both $G_{ik}$ and $T_{ik}$. We find
that in order that the fluid pressure and acceleration are {\em uniform} and
finite despite the presence of a coordinate singularity, the effective density
$\rho_e = \rho + \Lambda/8 \pi =0$, where $\Lambda$ is the cosmological
constant. Under weak energy condition, this would imply $\rho = \Lambda =0$ for
ESU. This means that if one would need to invoke a source of ``repulsive
gravity'' in some model, (i) the model must be non-static, (ii) the repulsive
gravity must be due to a ``quintessence'' or a ``dark energy'' fluid with
negative pressure and appear on the right hand side (RHS) of the Einstein
equation through $T_{ij}$ rather than through a fundamental constant residing
on the LHS of the same equation, and (iii) energy density of both normal matter
and the ``dark energy fluid'' should be time dependent. In fact, the repulsive
gravity would be due to a time independent $\Lambda$, it would be extremely
difficult to understand why the associated energy density should be
approximately $10^{120}$ times lower than the value predicted by quantum
gravity. On the other hand, for a dark energy fluid whose energy density is
time dependent, it would be much easier to understand such an extremely low
present energy density: the original initial value of the energy density of the
fluid could be equal to the quantum gravity value while the present low value
is due to decay with time.


title: Spin Hall Effect in Noncommutative Coordinates

abstract:
  A semiclassical constrained Hamiltonian system which was established to study
dynamical systems of matrix valued non-Abelian gauge fields is employed to
formulate spin Hall effect in noncommuting coordinates at the first order in
the constant noncommutativity parameter theta . The method is first illustrated
by studying the Hall effect on the noncommutative plane in a gauge independent
fashion. Then, the Drude model type and the Hall effect type formulations of
spin Hall effect are considered in noncommuting coordinates and \theta deformed
spin Hall conductivities which they provide are acquired. It is shown that by
adjusting \theta different formulations of spin Hall conductivity are
accomplished. Hence, the noncommutative theory can be envisaged as an effective
theory which unifies different approaches to similar physical phenomena.


title:
How to estimate the distance to the Warm Absorber in AGN from
  photoionized models

abstract:
  We present a method that allows us to estimate the distance from the
continuum source located in the center of AGN to the highly ionized gas called
warm absorber. We compute a set of constant total pressure photoionization
models compatible with the warm absorber conditions, where a metal-rich gas is
irradiated by a continuum in the form of a double power-law. The first
power-law is hard up to 100 keV and represents a radiation from an X-ray
source, while the second power-law extends downwards from several eVs and
illustrates a radiation from an accretion disk. When the ionized continuum is
dominated by the soft component, the warm absorber is heated by free-free
absorption, instead of Comptonization, and the transmitted spectra show
different absorption line characteristics for different values of the hydrogen
number density at the cloud illuminated surface. This fact results in the
possibility of deriving the number density at the cloud illuminated side from
observations and hence the distance to the warm absorber.


title: To sample or not to sample: Self-triggered control for nonlinear systems

abstract:
  Feedback control laws have been traditionally implemented in a periodic
fashion on digital hardware. Although periodicity simplifies the analysis of
the mismatch between the control design and its digital implementation, it also
leads to conservative usage of resources such as CPU utilization in the case of
embedded control. We present a novel technique that abandons the periodicity
assumption by using the current state of the plant to decide the next time
instant in which the state should be measured, the control law computed, and
the actuators updated. This technique, termed self-triggered control, is
developed for two classes of nonlinear control systems, namely, state-dependent
homogeneous systems and polynomial systems. The wide applicability of the
proposed results is illustrated in two well known physical examples: a jet
engine compressor and the rigid body.


title: High cadence observations of a global coronal wave by EUVI/STEREO

abstract:
  We report a large-scale coronal wave (so-called "EIT wave") observed with
high cadence by EUVI onboard STEREO in association with the GOES B9.5 flare and
double CME event on 19 May 2007. The EUVI instruments provide us with the
unprecedented opportunity to study the {\it dynamics} of flare/CME associated
coronal waves imaged in the extreme ultraviolet. The coronal wave under study
reveals deceleration, indicative of a freely propagating MHD wave.
Complementary analysis of the associated flare and erupting filament/CME hint
at wave initiation by the CME expanding flanks, which drive the wave only over
a limited distance. The associated flare is very weak and occurs too late to
account for the wave initiation.


title: Magnetization dynamics in optically excited nanostructured nickel films

abstract:
  In this work, Laser-induced magnetization dynamics of nanostructured nickel
films is investigated. The influence of the nanosize is discussed considering
the time-scale of hundreds of femtoseconds as well as the GHz regime. While no
nanosize effect is observed on the short time-scale, the excited magnetic mode
in the GHz regime can be identified by comparison with micromagnetic
simulations. The thickness dependence reveals insight on the dipole interaction
between single nickel structures. Also, transient reflectivity changes are
discussed.


title:
Symmetry of superconducting states with two orbitals on a tetragonal
  lattice: application to $LaO_{1-x}F_{x}FeAs$

abstract:
  We use group theory to classify the superconducting states of systems with
two orbitals on a tetragonal lattice. The orbital part of the superconducting
gap function can be either symmetric or anti-symmetric. For the orbital
symmetric state, the parity is even for spin singlet and odd for spin triplet;
for the orbital anti-symmetric state, the parity is odd for spin singlet and
even for spin triplet. The gap basis functions are obtained with the use of the
group chain scheme by taking into account the spin-orbit coupling. In the weak
pairing limit, the orbital anti-symmetric state is only stable for the
degenerate orbitals. Possible application to iron-based superconductivity is
discussed.


title: Spectroscopic factors for alpha decay in the $N_pN_n$ scheme

abstract:
  Lifetime values for alpha decay in even-even nuclei with $Z=84-98$ and
$N=128-152$ have been calculated in the superasymmetric fission model. The
interaction between the alpha particle and the daughter nucleus has been formed
in the double folding approach using a density dependent NN interaction. The
densities have been obtained using the Relativistic Mean Field formalism. The
spectroscopic factors for the decays have been deduced and are shown to vary
smoothly as a function of effective numbers of valence nucleons, $N_p$ and
$N_n$ chosen with a suitable core. The implication of such a smooth behaviour
has been discussed.


title: Track billiards

abstract:
  We study a class of planar billiards having the remarkable property that
their phase space consists up to a set of zero measure of two invariant sets
formed by orbits moving in opposite directions. The tables of these billiards
are tubular neighborhoods of differentiable Jordan curves that are unions of
finitely many segments and arcs of circles. We prove that under proper
conditions on the segments and the arcs, the billiards considered have non-zero
Lyapunov exponents almost everywhere. These results are then extended to a
similar class of of 3-dimensional billiards. Finally, we find that for some
subclasses of track billiards, the mechanism generating hyperbolicity is not
the defocusing one that requires every infinitesimal beam of parallel rays to
defocus after every reflection off of the focusing boundary.


title: Western Europe is warming much faster than expected

abstract:
  The warming trend of the last decades is now so strong that it is discernible
in local temperature observations. This opens the possibility to compare the
trend to the warming predicted by comprehensive climate models (GCMs), which up
to now could not be verified directly to observations on a local scale, because
the signal-to-noise ratio was too low. The observed temperature trend in
western Europe over the last decades appears much stronger than simulated by
state-of-the-art GCMs. The difference is very unlikely due to random
fluctuations, either in fast weather processes or in decadal climate
fluctuations. In winter and spring, changes in atmospheric circulation are
important; in spring and summer changes in soil moisture and cloud cover. A
misrepresentation of the North Atlantic Current affects trends along the coast.
Many of these processes continue to affect trends in projections for the 21st
century. This implies that climate predictions for western Europe probably
underestimate the effects of anthropogenic climate change.


title:
Nanolithography and manipulation of graphene using an atomic force
  microscope

abstract:
  We use an atomic force microscope (AFM) to manipulate graphene films on a
nanoscopic length scale. By means of local anodic oxidation with an AFM we are
able to structure isolating trenches into single-layer and few-layer graphene
flakes, opening the possibility of tabletop graphene based device fabrication.
Trench sizes of less than 30 nm in width are attainable with this technique.
Besides oxidation we also show the influence of mechanical peeling and
scratching with an AFM of few layer graphene sheets placed on different
substrates.