title:
Some issues concerning Large-Eddy Simulation of inertial particle
  dispersion in turbulent bounded flows

abstract:
  The problem of an accurate Eulerian-Lagrangian modeling of inertial particle
dispersion in Large Eddy Simulation (LES) of turbulent wall-bounded flows is
addressed. We run Direct Numerical Simulation (DNS) for turbulent channel flow
at shear Reynolds numbers equal to 150 and 300 and corresponding a-priori and
a-posteriori LES on differently coarse grids. We then tracked swarms of
different inertia particles and we examined the influence of filtering and of
Sub-Grid Scale (SGS) modeling for the fluid phase on particle velocity and
concentration statistics. We also focused on how particle preferential
segregation is predicted by LES. Results show that even ``well-resolved'' LES
is unable to reproduce the physics as demonstrated by DNS, both for particle
accumulation at the wall and for particle preferential segregation. Inaccurate
prediction is observed for the entire range of particles considered in this
study, even when the particle response time is much larger than the flow
timescales not resolved in LES. Both a-priori and a-posteriori tests indicate
that recovering the level of fluid and particle velocity fluctuations is not
enough to have accurate prediction of near-wall accumulation and local
segregation. This may suggest that reintroducing the correct amount of
higher-order moments of the velocity fluctuations is also a key point for SGS
closure models for the particle equation. Another important issue is the
presence of possible flow Reynolds number effects on particle dispersion. Our
results show that, in small Reynolds number turbulence and in the case of heavy
particles, the shear fluid velocity is a suitable scaling parameter to quantify
these effects.


title:
Estimating terrestrial uranium and thorium by antineutrino flux
  measurements

abstract:
  Uranium and thorium within the Earth produce a major portion of terrestrial
heat along with a measurable flux of electron antineutrinos. These elements are
key components in geophysical and geochemical models. Their quantity and
distribution drive the dynamics, define the thermal history, and are a
consequence of the differentiation of the Earth. Knowledge of uranium and
thorium concentrations in geological reservoirs relies largely on geochemical
model calculations. This research report describes the methods and criteria to
experimentally determine average concentrations of uranium and thorium in the
continental crust and in the mantle using site-specific measurements of the
terrestrial antineutrino flux. Optimal, model-independent determinations
involve significant exposures of antineutrino detectors remote from nuclear
reactors at both a mid-continental and a mid-oceanic site. This would require
major, new antineutrino detection projects. The results of such projects could
yield a greatly improved understanding of the deep interior of the Earth.


title: Effective Field Theories for Electrons in Crystalline Structures

abstract:
  We present an effective field theory formulation for a class of condensed
matter systems with crystalline structures for which some of the discrete
symmetries of the underlying crystal survive the long distance limit, up to
mesoscopic scales, and argue that this class includes interesting materials,
such as $Si$-doped $GaAs$. The surviving symmetries determine a limited set of
possible effective interactions, that we analyze in detail for the case of
$Si$-doped $GaAs$ materials. These coincide with the ones proposed in the
literature to describe the spin relaxation times for the $Si$-doped $Ga As$
materials, obtained here as a consequence of the choice of effective fields and
their symmetries. The resulting low-energy effective theory is described in
terms of three (six chiral) one-dimensional Luttinger liquid systems and their
corresponding intervalley transitions. We also discuss the Mott transition
within the context of the effective theory.

categories: cond-mat.mes-hall astro-ph cond-mat.other cond-mat.str-el hep-th


title: Feasibly Reducing KAT Equations to KA Equations

abstract:
  Kleene algebra (KA) is the algebra of regular events. Familiar examples of
Kleene algebras include regular sets, relational algebras, and trace algebras.
A Kleene algebra with tests (KAT) is a Kleene algebra with an embedded Boolean
subalgebra. The addition of tests allows one to encode {\tt while} programs as
KAT terms, thus the equational theory of KAT can express (propositional)
program equivalence. More complicated statements about programs can be
expressed in the Hoare theory of KAT, which suffices to encode Propositional
Hoare Logic.
  That the equational theory of KAT reduces to the equational theory of KA has
been shown by Cohen et al. Unfortunately, their reduction involves an
exponential blowup in the size of the terms involved. Here we give an alternate
feasible reduction.


title: Jet Geometrical Objects Depending on a Relativistic Time

abstract:
  In this paper we study a collection of jet geometrical concepts, we refer to
d-tensors, relativistic time dependent semisprays, harmonic curves and
nonlinear connections on the 1-jet space J1(R;M), necessary to the construction
of a Miron's-like geometrization for Lagrangians depending on a relativistic
time. The geometrical relations between these jet geometrical objects are
exposed.


title: One-Parameter Toric Deformations of Cyclic Quotient Singularities

abstract:
  In the case of two-dimensional cyclic quotient singularities, we classify all
one-parameter toric deformations in terms of certain Minkowski decompositions.
In particular, we describe to which components each such deformation maps, show
how to induce each deformation from a versal family, give explicit equations
for each deformation, describe the singularities in the general fibers, and
construct the corresponding partial simultaneous resolutions.


title: CLOUDS search for variability in brown dwarf atmospheres

abstract:
  Context: L-type ultra-cool dwarfs and brown dwarfs have cloudy atmospheres
that could host weather-like phenomena. The detection of photometric or
spectral variability would provide insight into unresolved atmospheric
heterogeneities, such as holes in a global cloud deck.
  Aims: It has been proposed that growth of heterogeneities in the global cloud
deck may account for the L- to T-type transition as brown dwarf photospheres
evolve from cloudy to clear conditions. Such a mechanism is compatible with
variability. We searched for variability in the spectra of five L6 to T6 brown
dwarfs in order to test this hypothesis.
  Methods: We obtained spectroscopic time series using VLT/ISAAC, over
0.99-1.13um, and IRTF/SpeX for two of our targets, in J, H and K bands. We
search for statistically variable lines and correlation between those.
  Results: High spectral-frequency variations are seen in some objects, but
these detections are marginal and need to be confirmed. We find no evidence for
large amplitude variations in spectral morphology and we place firm upper
limits of 2 to 3% on broad-band variability, on the time scale of a few hours.
The T2 transition brown dwarf SDSS J1254-0122 shows numerous variable features,
but a secure variability diagnosis would require further observations.
  Conclusions: Assuming that any variability arises from the rotation of
patterns of large-scale clear and cloudy regions across the surface, we find
that the typical physical scale of cloud cover disruption should be smaller
than 5-8% of the disk area for four of our targets. The possible variations
seen in SDSS J1254-0122 are not strong enough to allow us to confirm the cloud
breaking hypothesis.


title: Hyperbolicity of scalar-tensor theories of gravity

abstract:
  Two first order strongly hyperbolic formulations of scalar-tensor theories of
gravity (STT) allowing nonminimal couplings (Jordan frame) are presented along
the lines of the 3+1 decomposition of spacetime. One is based on the Bona-Masso
formulation while the other one employs a conformal decomposition similar to
that of Baumgarte-Shapiro-Shibata-Nakamura. A modified Bona-Masso slicing
condition adapted to the scalar-tensor theory is proposed for the analysis.
This study confirms that the scalar-tensor theory posses a well posed Cauchy
problem even when formulated in the Jordan frame.


title: Electron localization function for two-dimensional systems

abstract:
  The concept of the electron localization function (ELF) is extended to
two-dimensional (2D) electron systems. We show that the topological properties
of the ELF in 2D are considerably simpler than in molecules studied previously.
We compute the ELF and demonstrate its usefulness for various physical 2D
systems, focusing on semiconductor quantum dots that effectively correspond to
a confined 2D electron gas. The ELF visualizes the shell structure of harmonic
quantum dots and provides insight into electron bonding in quantum-dot
molecules. In external magnetic fields the ELF is found to be a useful measure
of vorticity when analyzing the properties of quantum-Hall droplets. We show
that the current-dependent term in the ELF expression is important in magnetic
fields.


title: NLO QCD corrections to W-b-bbar and Z-b-bbar production

abstract:
  We present NLO QCD results for W/Z gauge boson production with bottom quark
pairs at the Tevatron including full bottom-quark mass effects. We study the
impact of QCD corrections on both total cross-section and invariant mass
distribution of the bottom-quark pair. Including NLO QCD corrections greatly
reduces the dependence of the tree-level cross-section on the renormalization
and factorization scales. We also compare our calculation to a calculation that
considers massless bottom quarks and find that the bottom-quark mass effects
amount to about 8-10% of the total NLO QCD cross-section and can impact the
shape of the bottom-quark pair invariant mass distribution, in particular in
the low invariant mass region.


title:
A Comparison of Optical and Near-Infrared Colours of Magellanic Cloud
  Star Clusters with Predictions of Simple Stellar Population Models

abstract:
  We present integrated JHK_s 2MASS photometry and a compilation of
integrated-light optical photoelectric measurements for 84 star clusters in the
Magellanic Clouds. These clusters range in age from ~200 Myr to >10 Gyr, and
have [Fe/H] values from -2.2 to -0.1 dex. We find a spread in the intrinsic
colours of clusters with similar ages and metallicities, at least some of which
is due to stochastic fluctuations in the number of bright stars residing in
low-mass clusters. We use 54 clusters with the most reliable age and
metallicity estimates as test particles to evaluate the performance of four
widely used SSP models in the optical/NIR colour-colour space. All models
reproduce the reddening-corrected colours of the old (>10 Gyr) globular
clusters quite well, but model performance varies at younger ages. In order to
account for the effects of stochastic fluctuations in individual clusters, we
provide composite B-V, B-J, V-J, V-Ks and J-Ks colours for Magellanic Cloud
clusters in several different age intervals. The accumulated mass for most
composite clusters are higher than that needed to keep luminosity variations
due to stochastic fluctuations below the 10% level. The colours of the
composite clusters are clearly distinct in optical-NIR colour-colour space for
the following intervals of age: >10 Gyr, 2-9 Gyr, 1-2 Gyr, and 200 Myr-1 Gyr.
This suggests that a combination of optical plus NIR colours can be used to
differentiate clusters of different age and metallicity.


title: A Riemann mapping theorem for two-connected domains in the plane

abstract:
  We show how to express a conformal map of a general two connected domain in
the plane such that neither boundary component is a point to a representative
domain which has the virtue of having an explicit algebraic Bergman kernel
function. We shall explain why the representative domain is the best analogue
of the unit disc in the two connected setting. The conformal map will be given
as a simple and explicit algebraic function of an Ahlfors map of the domain
associated to a specially chosen point. It will follow that the conformal map
can be found by solving the same extremal problem that determines a Riemann map
in the simply connected case.


title: Rigid supersymmetry with boundaries

abstract:
  We construct rigidly supersymmetric bulk-plus-boundary actions, both in
$x$-space and in superspace. For each standard supersymmetric bulk action a
minimal supersymmetric bulk-plus-boundary action follows from an extended $F$-
or $D$-term formula. Additional separately supersymmetric boundary actions can
be systematically constructed using co-dimension one multiplets (boundary
superfields). We also discuss the orbit of boundary conditions which follow
from the Euler-Lagrange variational principle.


title: String algorithms and data structures

abstract:
  The string-matching field has grown at a such complicated stage that various
issues come into play when studying it: data structure and algorithmic design,
database principles, compression techniques, architectural features, cache and
prefetching policies. The expertise nowadays required to design good string
data structures and algorithms is therefore transversal to many computer
science fields and much more study on the orchestration of known, or novel,
techniques is needed to make progress in this fascinating topic. This survey is
aimed at illustrating the key ideas which should constitute, in our opinion,
the current background of every index designer. We also discuss the positive
features and drawback of known indexing schemes and algorithms, and devote much
attention to detail research issues and open problems both on the theoretical
and the experimental side.


title: The unusual Nova Cygni 2006 (V2362 Cyg)

abstract:
  Context: Optical nova lightcurves often have structures, such as rapid
declines and recoveries, due to nebular or dusty phases of the ejecta. Nova
Cygni 2006 (V2362 Cyg) underwent an unusual brightening after an early rapid
decline. The shape of the lightcurve can be compared to that of V1493 Aql, but
the whole event in that case was not as bright and only lasted a couple of
weeks. V2362 Cyg had a moderately fast decline of t_2 = 9.0 before
rebrightening, which lasted 250 days after maximum. Aims: We present an
analysis of our own spectroscopic investigations in combination with AAVSO
photometric data covering the whole rebrightening phase until the return to the
final decline. Methods: We used the medium resolution spectroscopy obtained in
ten nights over a period of 79 nights to investigate the change of the velocity
structure of the ejecta. The publicly available AAVSO photometry was used to
analyze the overall properties and the energy of the brightening. Results:
Although the behavior of the main outburst (velocity, outburst magnitude, and
decline timescales) resembles a ``normal'' classical nova, the shell clearly
underwent a second fast mass ejecting phase, causing the unusual properties.
The integrated flux during this event contributes ~ 40 % to the total radiation
energy of the outburst. The evolution of the H_alpha profile during the bump
event is obtained by subtracting the emission of the detached shells of the
main eruption by a simple optically thin model. A distance of D ~ 7.5
{+3.0}{-2.5} kpc and an interstellar extinction E(B-V) = 0.6 +/- 0.1 was also
derived.


title:
A STIS Survey for OVI Absorption Systems at 0.12 < z < 0.5 I.: The
  Statistical Properties of Ionized Gas

abstract:
  We have conducted a systematic survey for intervening OVI absorbers in
available echelle spectra of 16 QSOs at z_QSO = 0.17-0.57. These spectra were
obtained using HST/STIS with the E140M grating. Our search uncovered a total of
27 foreground OVI absorbers with rest-frame absorption equivalent width
W_r(1031) > 25mA. Ten of these QSOs exhibit strong OVI absorbers in their
vicinity. Our OVI survey does not require the known presence of Lya, and the
echelle resolution allows us to identify the OVI absorption doublet based on
their common line centroid and known flux ratio. We estimate the total redshift
survey path, \Delta z, using a series of Monte-Carlo simulations, and find that
\Delta z=1.66, 2.18, and 2.42 for absorbers of strength W_r = 30, 50 and 80mA,
respectively, leading to a number density of dN(W > 50mA)/dz = 6.7 +/- 1.7 and
dN(W > 30mA)/dz = 10.4 +/- 2.2. In contrast, we also measure dN/dz = 27 +/- 9
for OVI absorbers of W_r > 50mA at |\Delta v|< 5000 kms from the background
QSOs. Using the random sample of OVI absorbers with well characterized survey
completeness, we estimate a mean cosmological mass density of the OVI gas
\Omega(OVI)h = 1.7 +/- 0.3 x 10^-7. In addition, we show that <5% of OVI
absorbers originate in underdense regions that do not show a significant trace
of HI. Furthermore, we show that the neutral gas column N(HI) associated with
these OVI absorbers spans nearly five orders of magnitude, and show moderate
correlation with N(OVI). Finally, while the number density of OVI absorbers
varies substantially from one sightline to another, it also appears to be
inversely correlated with the number density of HI absorbers along individual
lines of sight.


title:
A STIS Survey for OVI Absorption Systems at 0.12 < z < 0.5 II.: Physical
  Conditions of the Ionised Gas

abstract:
  We present a complete catalogue of 27 O VI absorbers at low redshift (0.12 <
z < 0.5) from a blind survey of 16 QSO echelle spectra in the HST/STIS data
archive. These absorbers are identified based only upon matching line profiles
and the expected doublet ratio between the \lambda\lambda 1031, 1037
transitions. Subsequent searches are carried out to identify their associated
transitions. Here we present all relevant absorption properties. By considering
absorption components of different species which are well-aligned in
velocity-space, we derive gas temperatures and non-thermal broadening values,
b_{nt}. We show that in all 16 cases considered the observed line width is
dominated by non-thermal motion and that gas temperatures are well below those
expected for O^5+ in collisional ionization equilibrium. This result reaffirms
previous findings from studies of individual lines of sight, but are at odds
with expectations for a WHIM origin. At least half of the absorbers can be
explained by a simple photoionization model. In addition, in some absorbers we
find evidence for large variation in gas density/metallicity across components
in individual absorbers. Comparisons of multiple associated metal species
further show that under the assumption of the gas being photoionized by the
metagalacitic background radiation field, the absorbing clouds have gas
densities <n_H> < -2.9 and sizes L > 1\kpc. Finally, we compare our absorber
selection with the results of other independent studies.


title: A Deep 0.3-10 keV Spectrum of the H$_{2}$O Maser Galaxy IC 2560

abstract:
  We present a new XMM-Newton spectrum of the Seyfert 2 nucleus of IC 2560,
which hosts H$_{2}$O maser emission from an inclined Keplerian accretion disk.
The X-ray spectrum shows soft excess due to multi-temperature ionized plasma, a
hard continuum and strong emission features, from Mg, Si, S, Ca, Fe and Ni,
mainly due to fluorescence. It is consistent with reflection of the continuum
from a mostly neutral medium and obscuration due to a high column density, $>$
10$^{24}$ cm$^{-2}$. The amplitude of the reflected component may exceed 10% of
the central unobscured luminosity. This is higher than the reflected fraction,
of a few percent, observed in other Seyfert 2 sources like NGC 4945. We observe
an emission line at 6.7 keV, possibly due to FeXXV, undetected in previous
Chandra observations. The absorption column density associated with this line
is less than 10$^{23}$ cm$^{-2}$, lower than the obscuration of the central
source. We hypothesize that this highly ionized Fe line emission originates in
warm gas, also responsible for a scattered component of continuum emission that
may dominate the spectrum between 1 and 3 keV. We compare X-ray and maser
emission characteristics of IC 2560 and other AGN that exhibit water maser
emission originating in disk structures around central engines. The temperature
for the region of the disk associated with maser action is consistent with the
expected 400-1000K range. The clumpiness of disk structures (inferred from the
maser distribution) may depend on the unobscured luminosities of the central
engines.


title:
Observational Constraints on the Dependence of Radio-Quiet Quasar X-ray
  Emission on Black Hole Mass and Accretion Rate

abstract:
  In this work we use a sample of 318 radio-quiet quasars (RQQ) to investigate
the dependence of the ratio of optical/UV flux to X-ray flux, alpha_ox, and the
X-ray photon index, Gamma_X, on black hole mass, UV luminosity relative to
Eddington, and X-ray luminosity relative to Eddington. Our sample is drawn from
the SDSS, with X-ray data from ROSAT and Chandra, and optical data mostly from
the SDSS; 153 of these sources have estimates of Gamma_X from Chandra. We
estimate M_BH using standard estimates derived from the Hbeta, Mg II, and C IV
broad emission lines. Our sample spans a broad range in black hole mass (10^6 <
M_BH / M_Sun < 10^10) and redshift (z < 4.8). We find that alpha_ox increases
with increasing M_BH and L_UV / L_Edd, and decreases with increasing L_X /
L_Edd. In addition, we confirm the correlation seen in previous studies between
Gamma_X and M_BH and both L_UV / L_Edd and L_X / L_Edd; however, we also find
evidence that the dependence of Gamma_X of these quantities is not monotonic,
changing sign at M_BH ~ 3 x 10^8 M_Sun. We argue that the alpha_ox correlations
imply that the fraction of bolometric luminosity emitted by the accretion disk,
as compared to the corona, increases with increasing accretion rate relative to
Eddington. In addition, we argue that the Gamma_X trends are caused by a
dependence of X-ray spectral index on accretion rate. We discuss our results
within the context of accretion models with comptonizing corona, and discuss
the implications of the alpha_ox correlations for quasar feedback. To date,
this is the largest study of the dependence of RQQ X-ray parameters on black
hole mass and related quantities, and the first to attempt to correct for the
large statistical uncertainty in the broad line mass estimates.


title: Splitting finite antichains in the homomorphism order

abstract:
  A structural condition is given for finite maximal antichains in the
homomorphism order of relational structures to have the splitting property. It
turns out that non-splitting antichains appear only at the bottom of the order.
Moreover, we examine looseness and finite antichain extension property for some
subclasses of the homomorphism poset. Finally, we take a look at cut-points in
this order.


title: On Tree Amplitudes in Gauge Theory and Gravity

abstract:
  The BCFW recursion relations provide a powerful way to compute tree
amplitudes in gauge theories and gravity, but only hold if some amplitudes
vanish when two of the momenta are taken to infinity in a particular complex
direction. This is a very surprising property, since individual Feynman
diagrams all diverge at infinite momentum. In this paper we give a simple
physical understanding of amplitudes in this limit, which corresponds to a hard
particle with (complex) light-like momentum moving in a soft background, and
can be conveniently studied using the background field method exploiting
background light-cone gauge. An important role is played by enhanced spin
symmetries at infinite momentum--a single copy of a "Lorentz" group for gauge
theory and two copies for gravity--which together with Ward identities give a
systematic expansion for amplitudes at large momentum. We use this to study
tree amplitudes in a wide variety of theories, and in particular demonstrate
that certain pure gauge and gravity amplitudes do vanish at infinity. Thus the
BCFW recursion relations can be used to compute completely general gluon and
graviton tree amplitudes in any number of dimensions. We briefly comment on the
implications of these results for computing massive 4D amplitudes by KK
reduction, as well understanding the unexpected cancelations that have recently
been found in loop-level gravity amplitudes.


title:
Long-range potentials and $(n-1)d+ns$ molecular resonances in an
  ultracold rydberg gas

abstract:
  We have calculated long-range molecular potentials of the $0_g^{+}$,
$0_u^{-}$ and $1_u$ symmetries between highly-excited rubidium atoms. Strong
$np+np$ potentials characterized by these symmetries are important in
describing interaction-induced phenomena in the excitation spectra of high $np$
Rydberg states. Long-range molecular resonances are such phenomena and they
were first reported in S.M. Farooqi {\it et al.}, Phys. Rev. Lett. {\bf 91}
183002. One class of these resonances occurs at energies corresponding to
excited atom pairs $(n-1)d+ns$. Such resonances are attributed to $\ell$-mixing
due to Rydberg-Rydberg interactions so that otherwise forbidden molecular
transitions become allowed. We calculate molecular potentials in Hund's case
(c), use them to find the resonance lineshape and compare to experimental
results.


title: Mapping the Shores of the Brown Dwarf Desert I.: Upper Scorpius

abstract:
  We present the results of a survey for stellar and substellar companions to
82 young stars in the nearby OB association Upper Scorpius. This survey used
nonredundant aperture-mask interferometry to achieve typical contrast limits of
DeltaK~5-6 at the diffraction limit, revealing 12 new binary companions that
lay below the detection limits of traditional high-resolution imaging; we also
summarize a complementary snapshot imaging survey that discovered 7 directly
resolved companions. The overall frequency of binary companions (~35+5/-4% at
separations of 6-435 AU) appears to be equivalent to field stars of similar
mass, but companions could be more common among lower-mass stars than for the
field. The companion mass function has statistically significant differences
compared to several suggested mass functions for the field, and we suggest an
alternate log-normal parameterization of the mass-function. Our survey limits
encompass the entire brown dwarf mass range, but we only detected a single
companion that might be a brown dwarf; this deficit resembles the so-called
``brown dwarf desert'' that has been observed by radial-velocity planet
searches. Finally, our survey's deep detection limits extend into the top of
the planetary mass function, reaching 8-12 MJup for half of our sample. We have
not identified any planetary companions at high confidence (>99.5%), but we
have identified four candidate companions at lower confidence (>97.5%) that
merit additional followup to confirm or disprove their existence.


title:
On the Stellar Populations in Faint Red Galaxies in the Hubble Ultra
  Deep Field

abstract:
  We study the nature of faint, red-selected galaxies at z ~ 2-3 using the
Hubble Ultra Deep Field (HUDF) and Spitzer IRAC photometry. We detect candidate
galaxies to H < 26 mag, probing lower-luminosity (lower mass) galaxies at these
redshifts. We identify 32 galaxies satisfying the (J - H) > 1.0 mag color
selection, 16 of which have unblended [3.6um] and [4.5um] IRAC photometry. We
derive photometric redshifts, masses, and stellar population parameters for
these objects. We find that the selected objects span a diverse range of
properties over a large range of redshifts, 1 < z < 3.5. A substantial fraction
(11/32) appear to be lower-redshift (z < 2.5), heavily obscured dusty galaxies
or edge-on spiral galaxies, while others (12/32) appear to be galaxies at 2 < z
< 3.5 whose light at rest-frame optical wavelengths is dominated by evolved
stellar populations. Interestingly, by including Spitzer data many candidates
for galaxies dominated by evolved stellar populations are rejected, and for
only a subset of the sample (6/16) do the data favor this interpretation. We
place an upper limit on the space and stellar mass density of candidate massive
evolved galaxies. The z > 2.5 objects that are dominated by evolved stellar
populations have a space density at most one-third that of z ~ 0 red,
early-type galaxies. Therefore, at least two-thirds of present-day early-type
galaxies assemble or evolve into their current configuration at redshifts below
2.5. We find a dearth of candidates for low-mass galaxies at 1.5 < z < 3 that
are dominated by passively evolving stellar populations even though the data
should be sensitive to them; thus, at these redshifts, galaxies whose light is
dominated by evolved stellar populations are restricted to only those galaxies
that have assembled high stellar mass.[Abridged]


title:
The shape distribution of asteroid families -- evidence for evolution
  driven by small impacts

abstract:
  A statistical analysis of brightness variability of asteroids reveals how
their shapes evolve from elongated to rough spheroidal forms, presumably driven
by impact-related phenomena. Based on the Sloan Digital Sky Survey Moving
Object Catalog, we determined the shape distribution of 11,735 asteroids, with
special emphasis on eight prominent asteroid families. In young families,
asteroids have a wide range of shape elongations, implying
fragmentation-formation. In older families we see an increasing number of rough
spheroids, in agreement with the predictions of an impact-driven evolution. Old
families also contain a group of moderately elongated members, which we suggest
correspond to higher-density, more impact-resistant cores of former fragmented
asteroids that have undergone slow shape erosion. A few percent of asteroids
have very elongated shapes, and can either be young fragments or tidally
reshaped bodies. Our results confirm that the majority of asteroids are
gravitationally bound ``rubble piles''.


title: NUV-IR colours of red sequence galaxies in local clusters

abstract:
  We present GALEX near-UV (NUV) and 2MASS J band photometry for red sequence
galaxies in local clusters. We define quiescent samples according to a strict
emission threshold, removing galaxies with very recent star formation. We
analyse the NUV-J colour-magnitude relation (CMR) and find that the intrinsic
scatter is an order of magnitude larger than for the analogous optical CMR
(~0.35 rather than 0.05 mag), in agreement with previous studies. Comparing the
NUV-J colours with spectroscopically-derived stellar population parameters, we
find a strong (> 5.5sigma) correlation with metallicity, only a marginal trend
with age, and no correlation with the alpha/Fe ratio. We explore the origin of
the large scatter and conclude that neither aperture effects nor the UV upturn
phenomenon contribute significantly. We show that the scatter could be
attributed to simple `frosting' by either a young or a low metallicity
subpopulation.


title:
MAGIC observations of the unidentified TeV gamma-ray source TeV
  J2032+4130

abstract:
  We observed the first known very high energy (VHE) gamma-ray emitting
unidentified source, TeV J2032+4130, for 94 hours with the MAGIC telescope. The
source was detected with a significance of 5.6 sigma. The flux, position, and
angular extension are compatible with the previous ones measured by the HEGRA
telescope system five years ago. The integral flux amounts to
(4.5+-0.3stat+-0.35sys)x10^{-13} ph cm$^{-2}$ s$^{-1}$ above 1 TeV. The source
energy spectrum, obtained with the lowest energy threshold to date, is
compatible with a single power law with a hard photon index of
Gamma=-2.0+-0.3stat+-0.2sys.


title: Sublattices of the lattice of local clones

abstract:
  We investigate the complexity of the lattice of local clones over a countably
infinite base set. In particular, we prove that this lattice contains all
algebraic lattices with at most countably many compact elements as complete
sublattices, but that the class of lattices embeddable into the local clone
lattice is strictly larger than that.


title:
The volume and time comparison principle and transition probability
  estimates for random walks

abstract:
  This paper presents necessary and sufficient conditions for on- and
off-diagonal transition probability estimates for random walks on weighted
graphs. On the integer lattice and on may fractal type graphs both the volume
of a ball and the mean exit time from a ball is independent of the centre,
uniform in space. Here the upper estimate is given without such restriction and
two-sided estimate is given if uniformity in the space assumed only for the
mean exit time.


title:
Quantum kinetic equation and universal conductance fluctuations in
  graphene

abstract:
  We analyze universal conductance fluctuations (UCF) in graphene in the
framework of diagrammatic perturbation theory in the metallic regime. It is
shown that strong inter-valley scattering lifts the valley degeneracy of
electronic states, whereas at weak inter-valley scattering two valleys
contribute independently such that the variance of UCF would be expected to
show sample- and geometry-dependent behavior.


title:
Analogy between Three-Dimensional Helimagnetic Metals and
  Two-Dimensional Nonmagnetic Metals: Transport in the Weak-Disorder Regime

abstract:
  We present a quasi-particle model that allows for a simple description of the
electronic properties of metallic helimagnets. For weak quenched disorder, we
find a leading linear temperature dependence of the electrical conductivity for
3-d materials. This is reminiscent of the behavior of nonmagnetic 2-d systems,
and reflects a general tendency of certain properties of bulk helimagnets to
appear effectively 2-d. The sign of the effect is opposite to that in
nonmagnetic 2-d materials. These surprising predictions should be observable in
weak helimagnets.


title: Many-body dynamics of Rydberg excitation using the $\Omega$-expansion

abstract:
  We investigate the excitation dynamics of Rydberg atoms in ultracold atomic
samples by expanding the excitation probability and the correlation function
between excited atoms in powers of the isolated atom Rabi frequency $\Omega$.
In the Heisenberg picture, we give recurrence relations to calculate any order
of the expansions, which ere expected to be well-behaved for arbitrarily strong
interactions. For homogeneous large samples, we give the explicit form of the
expansions, up to $\Omega^4$, averaged over all possible random spatial
distributions of atoms, for the most important cases of excitation pulses and
interactions.


title: Quantum toroidal algebras and their representations

abstract:
  Quantum toroidal algebras (or double affine quantum algebras) are defined
from quantum affine Kac-Moody algebras by using the Drinfeld quantum
affinization process. They are quantum groups analogs of elliptic Cherednik
algebras (elliptic double affine Hecke algebras) to whom they are related via
Schur-Weyl duality. In this review paper, we give a glimpse on some aspects of
their very rich representation theory in the context of general quantum
affinizations. We illustrate with several examples. We also announce new
results and explain possible further developments, in particular on finite
dimensional representations at roots of unity.


title:
Removing the Stiffness of Elastic Force from the Immersed Boundary
  Method for the 2D Stokes Equations

abstract:
  The Immersed Boundary method has evolved into one of the most useful
computational methods in studying fluid structure interaction. On the other
hand, the Immersed Boundary method is also known to suffer from a severe
timestep stability restriction when using an explicit time discretization. In
this paper, we propose several efficient semi-implicit schemes to remove this
stiffness from the Immersed Boundary method for the two-dimensional Stokes
flow. First, we obtain a novel unconditionally stable semi-implicit
discretization for the immersed boundary problem. Using this unconditionally
stable discretization as a building block, we derive several efficient
semi-implicit schemes for the immersed boundary problem by applying the Small
Scale Decomposition to this unconditionally stable discretization. Our
stability analysis and extensive numerical experiments show that our
semi-implicit schemes offer much better stability property than the explicit
scheme. Unlike other implicit or semi-implicit schemes proposed in the
literature, our semi-implicit schemes can be solved explicitly in the spectral
space. Thus the computational cost of our semi-implicit schemes is comparable
to that of an explicit scheme, but with a much better stability property.


title: (No) Eternal Inflation and Precision Higgs Physics

abstract:
  Even if nothing but a light Higgs is observed at the LHC, suggesting that the
Standard Model is unmodified up to scales far above the weak scale, Higgs
physics can yield surprises of fundamental significance for cosmology. As has
long been known, the Standard Model vacuum may be metastable for low enough
Higgs mass, but a specific value of the decay rate holds special significance:
for a very narrow window of parameters, our Universe has not yet decayed but
the current inflationary period can not be future eternal. Determining whether
we are in this window requires exquisite but achievable experimental precision,
with a measurement of the Higgs mass to 0.1 GeV at the LHC, the top mass to 60
MeV at a linear collider, as well as an improved determination of alpha_s by an
order of magnitude on the lattice. If the parameters are observed to lie in
this special range, particle physics will establish that the future of our
Universe is a global big crunch, without harboring pockets of eternal
inflation, strongly suggesting that eternal inflation is censored by the
fundamental theory. This conclusion could be drawn even more sharply if
metastability with the appropriate decay rate is found in the MSSM, where the
physics governing the instability can be directly probed at the TeV scale.


title:
Inclination-Dependent Extinction Effects in Disk Galaxies in the Sloan
  Digital Sky Survey

abstract:
  We analyze the absolute magnitude (M_r) and color (u-r) of low redshift
(z<0.06) galaxies in the Sloan Digital Sky Survey Data Release 6. galaxies with
nearly exponential profiles (Sloan parameter fracDeV < 0.1) fall on the blue
sequence of the color - magnitude diagram; if, in addition, these exponential
galaxies have M_r < -19, they show a dependence of u-r color on apparent axis
ratio q expected for a dusty disk galaxy. By fitting luminosity functions for
exponential galaxies with different values of q, we find that the dimming is
well described by the relation Delta M_r = 1.27 (log q)^2, rather than the
Delta M = C log q law that is frequently assumed. When the absolute magnitudes
of bright exponential galaxies are corrected to their "face-on" value, M_r^f =
M_r - Delta M_r, the average u-r color is linearly dependent on M_r^f for a
given value of q. Nearly face-on exponential galaxies (q > 0.9) have a shallow
dependence of mean u-r color on M_r^f (0.096 magnitudes redder for every
magnitude brighter). By comparison, nearly edge-on exponential galaxies (q <
0.3) are 0.265 magnitudes redder for every magnitude brighter. When the dimming
law Delta M = 1.27 (log q)^2 is used to create an inclination-corrected sample
of bright exponential galaxies, their apparent shapes are confirmed to be
consistent with a distribution of mildly non-circular disks, with median
short-to-long axis ratio gamma = 0.22 and median disk ellipticity epsilon =
0.08.


title:
Strongly bound mesons at finite temperature and in magnetic fields from
  AdS/CFT

abstract:
  We study mesons in N=4 super Yang-Mills theory with fundamental flavors added
at large 't Hooft coupling using the gauge/gravity correspondence. High-spin
mesons are well described by using semiclassical string configurations. We
determine the meson spectrum at finite temperature and in a background magnetic
field.


title: Halperin (m, m',n) bilayer quantum Hall states on thin cylinders

abstract:
  The Halperin $(m,m',n)$ bilayer quantum Hall states are studied on thin
cylinders. In this limit, charge density wave patterns emerge that are
characteristic of the underlying quantum Hall state. The general patterns are
worked out from a variant of the plasma analogy. Torus degeneracies are
recovered, and for some important special cases a connection to well-known spin
chain physics is made. By including interlayer tunneling, we also work out the
critical behavior of a possible phase transition between the $(331)$ state and
the non-abelian Moore-Read state in the thin cylinder limit.


title:
The Effect of Mutators on Adaptability in Time-Varying Fitness
  Landscapes

abstract:
  This Letter studies the quasispecies dynamics of a population capable of
genetic repair evolving on a time-dependent fitness landscape. We develop a
model that considers an asexual population of single-stranded, conservatively
replicating genomes, whose only source of genetic variation is due to copying
errors during replication. We consider a time-dependent, single-fitness-peak
landscape where the master sequence changes by a single point mutation every
time $ \tau $. We are able to analytically solve for the evolutionary dynamics
of the population in the point-mutation limit. In particular, our model
provides an analytical expression for the fraction of mutators in the dynamic
fitness landscape that agrees well with results from stochastic simulations.


title: Towards an optimal algorithm for recognizing Laman graphs

abstract:
  Laman graphs are fundamental to rigidity theory. A graph G with n vertices
and m edges is a generic minimally rigid graph (Laman graph), if m=2n-3 and
every induced subset of k vertices spans at most 2k-3 edges. We consider the
verification problem: Given a graph G with n vertices, decide if it is Laman.
We present an algorithm that takes O(T(n)+n log n) time, where T(n) is the best
time to extract two edge disjoint spanning trees from G or decide no such trees
exist. Our algorithm exploits a known construction called red-black hierarchy
(RBH), that is a certificate for Laman graphs. First, we show how to verify if
G admits an RBH and argue this is enough to conclude whether G is Laman or not.
Second, we show how to construct the RBH using a two steps procedure that is
simple and easy to implement. Finally, we point out some difficulties in using
red-black hierarchies to compute a Henneberg construction, which seem to imply
super-quadratic time algorithms when used for embedding a planar Laman graph as
a pointed pseudo-triangulation.


title: Multiple Uncertainties in Time-Variant Cosmological Particle Data

abstract:
  Though the mediums for visualization are limited, the potential dimensions of
a dataset are not. In many areas of scientific study, understanding the
correlations between those dimensions and their uncertainties is pivotal to
mining useful information from a dataset. Obtaining this insight can
necessitate visualizing the many relationships among temporal, spatial, and
other dimensionalities of data and its uncertainties. We utilize multiple views
for interactive dataset exploration and selection of important features, and we
apply those techniques to the unique challenges of cosmological particle
datasets. We show how interactivity and incorporation of multiple visualization
techniques help overcome the problem of limited visualization dimensions and
allow many types of uncertainty to be seen in correlation with other variables.


title:
Many-body Rabi oscillations of Rydberg excitation in small mesoscopic
  samples

abstract:
  We investigate the collective aspects of Rydberg excitation in ultracold
mesoscopic systems. Strong interactions between Rydberg atoms influence the
excitation process and impose correlations between excited atoms. The
manifestations of the collective behavior of Rydberg excitation are the
many-body Rabi oscillations, spatial correlations between atoms as well as the
fluctuations of the number of excited atoms. We study these phenomena in detail
by numerically solving the many-body Schr\"edinger equation.


title:
Transmission behaviors of single mode hollow metallic waveguides
  dedicated to mid-infrared nulling interferometry

abstract:
  This paper reports the characterization of hollow metallic waveguides (HMW)
to be used as single-mode wavefront filters for nulling interferometry in the
6-20 microns range. The measurements presented here were performed using both
single-mode and multimode conductive waveguides at 10.6 microns. We found
propagation losses of about 16dB/mm, which are mainly due to the theoretical
skin effect absorption in addition to the roughness of the waveguide metallic
walls. The input and output coupling efficiency of our samples has been
improved by adding tapers to minimize the impedance mismatch. A proper
distinction between propagation losses and coupling losses is presented.
Despite their elevate propagation losses, HMW show excellent spatial filtering
capabilities in a spectral range where photonics technologies are only
emerging.


title: A Coaxial Vortex Ring Model for Vortex Breakdown

abstract:
  A simple - yet plausible - model for B-type vortex breakdown flows is
postulated; one that is based on the immersion of a pair of slender coaxial
vortex rings in a swirling flow of an ideal fluid rotating around the axis of
symmetry of the rings. It is shown that this model exhibits in the advection of
passive fluid particles (kinematics) just about all of the characteristics that
have been observed in what is now a substantial body of published research on
the phenomenon of vortex breakdown. Moreover, it is demonstrated how the very
nature of the fluid dynamics in axisymmetric breakdown flows can be predicted
and controlled by the choice of the initial ring configurations and their
vortex strengths. The dynamic intricacies produced by the two ring + swirl
model are illustrated with several numerical experiments.


title: Recurrence times and large deviations

abstract:
  We give a criterion to determine the large deviation rate functions for
abstract dynamical systems on towers. As an application of this criterion we
show the level 2 large deviation principle for some class of smooth interval
maps with nonuniform hyperbolicity.


title:
Finding Galaxy Groups In Photometric Redshift Space: the Probability
  Friends-of-Friends (pFoF) Algorithm

abstract:
  We present a structure finding algorithm designed to identify galaxy groups
in photometric redshift data sets: the probability friends-of-friends (pFoF)
algorithm. This algorithm is derived by combining the friends-of-friends
algorithm in the transverse direction and the photometric redshift probability
densities in the radial dimension. The innovative characteristic of our
group-finding algorithm is the improvement of redshift estimation via the
constraints given by the transversely connected galaxies in a group, based on
the assumption that all galaxies in a group have the same redshift. Tests using
the Virgo Consortium Millennium Simulation mock catalogs allow us to show that
the recovery rate of the pFoF algorithm is larger than 80% for mock groups of
at least $2\times10^{13}M_{\sun}$, while the false detection rate is about 10%
for pFoF groups containing at least $\sim8$ net members. Applying the algorithm
to the CNOC2 group catalogs gives results which are consistent with the mock
catalog tests. From all these results, we conclude that our group-finding
algorithm offers an effective yet simple way to identify galaxy groups in
photometric redshift catalogs.


title: Mobility and Social Network Effects on Extremist Opinions

abstract:
  Understanding the emergence of extreme opinions and in what kind of
environment they might become less extreme is a central theme in our modern
globalized society. A model combining continuous opinions and observed discrete
actions (CODA) capable of addressing the important issue of measuring how
extreme opinions might be has been recently proposed. In this paper I show
extreme opinions to arise in a ubiquitous manner in the CODA model for a
multitude of social network structures. Depending on network details reducing
extremism seems to be possible. However, a large number agents with extreme
opinions is always observed. A significant decrease in the number of extremists
can be observed by allowing agents to change their positions in the network.


title: Generalized permutation patterns -- a short survey

abstract:
  An occurrence of a classical pattern p in a permutation \pi is a subsequence
of \pi whose letters are in the same relative order (of size) as those in p. In
an occurrence of a generalized pattern, some letters of that subsequence may be
required to be adjacent in the permutation. Subsets of permutations
characterized by the avoidance--or the prescribed number of occurrences--of
generalized patterns exhibit connections to an enormous variety of other
combinatorial structures, some of them apparently deep. We give a short
overview of the state of the art for generalized patterns.


title: Continuity properties of transport coefficients in simple maps

abstract:
  We consider families of dynamics that can be described in terms of
Perron-Frobenius operators with exponential mixing properties. For piecewise
C^2 expanding interval maps we rigorously prove continuity properties of the
drift J(l) and of the diffusion coefficient D(l) under parameter variation. Our
main result is that D(l) has a modulus of continuity of order
O(|dl||log|dl|)^2), i.e. D(l) is Lipschitz continuous up to quadratic
logarithmic corrections. For a special class of piecewise linear maps we
provide more precise estimates at specific parameter values. Our analytical
findings are verified numerically for the latter class of maps by using exact
formulas for the transport coefficients. We numerically observe strong local
variations of all continuity properties.


title: LHC/ILC Interplay in SUSY Searches

abstract:
  Combined analyses at the Large Hadron Collider and at the International
Linear Collider are important to reveal precisely the new physics model as, for
instance, supersymmetry. Examples are presented where ILC results as input for
LHC analyses could be crucial for the identification of signals as well as of
the underlying model. The synergy of both colliders leads also to rather
accurate SUSY parameter determination and powerful mass constraints even if the
scalar particles have masses in the multi-TeV range.


title: Challenge of polarized beams at future colliders

abstract:
  A short overview about the potential of polarized beams at future colliders
is given. In particular the baseline design for polarized beams at the ILC is
presented and the physics case for polarized $e^-$ and $e^+$ is discussed. In
order to fulfil the precision requirements spin tracking from the source to the
interaction point is needed. Updates concerning the theoretical calculations as
well as their implementation in simulation codes are reported.


title: Dispersion forces between an atom and a perfectly conducting wedge

abstract:
  We consider the interaction between an electrically polarizable atom in its
fundamental state and a wedge constituted by two semi-infinite perfectly
conducting plates. Using a formalism based on a master equation, we compute the
dispersion force on the atom for both retarded and non-retarded regimes.


title: RHESSI Spectral Fits of Swift GRBs

abstract:
  One of the challenges of the Swift era has been accurately determining Epeak
for the prompt GRB emission. RHESSI, which is sensitive from 30 keV to 17 MeV,
can extend spectral coverage above the Swift-BAT bandpass. Using the public
Swift data, we present results of joint spectral fits for 26 bursts co-observed
by RHESSI and Swift-BAT through May 2007. We compare these fits to estimates of
Epeak which rely on BAT data alone. A Bayesian Epeak estimator gives better
correspondence with our measured results than an estimator relying on
correlations with the Swift power law indices.


title:
Cryptanalysis of the Hillery-Buzek-Berthiaume quantum secret-sharing
  protocol

abstract:
  The participant attack is the most serious threat for quantum secret-sharing
protocols. We present a method to analyze the security of quantum
secret-sharing protocols against this kind of attack taking the scheme of
Hillery, Buzek, and Berthiaume (HBB) [Phys. Rev. A 59 1829 (1999)] as an
example. By distinguishing between two mixed states, we derive the necessary
and sufficient conditions under which a dishonest participant can attain all
the information without introducing any error, which shows that the HBB
protocol is insecure against dishonest participants. It is easy to verify that
the attack scheme of Karlsson, Koashi, and Imoto [Phys. Rev. A 59, 162 (1999)]
is a special example of our results. To demonstrate our results further, we
construct an explicit attack scheme according to the necessary and sufficient
conditions. Our work completes the security analysis of the HBB protocol, and
the method presented may be useful for the analysis of other similar protocols.


title: A tidal disruption model for the gamma-ray burst of GRB 060614

abstract:
  The combination of a long duration and the absence of any accompanying
supernova clearly shows that GRB 060614 can not be grouped into the two
conventional classes of gamma-ray bursts, i.e. the long/soft bursts deemed to
be collapsars and the short/hard bursts deemed to be merging binary compact
stars. A new progenitor model is required for this anomalous gamma-ray burst.
We propose that GRB 060614 might be produced through the tidal disruption of a
star by an intermediate mass black hole. In this scenario, the long duration
and the lack of any associated supernova are naturally expected. The
theoretical energy output is also consistent with observations. The observed
9-s periodicity in the $\gamma$-ray light curve of GRB 060614 can also be
satisfactorily explained.


title:
Revisiting the security of quantum dialogue and bidirectional quantum
  secure direct communication

abstract:
  From the perspective of information theory and cryptography, we analyze the
security of two quantum dialogue protocols and a bidirectional quantum secure
direct communication (QSDC) protocol, and point out that the transmitted
information would be partly leaked out in them. That is, any eavesdropper can
elicit some information about the secrets from the public annunciations of the
legal users. This phenomenon should have been strictly forbidden in a quantum
secure communication. In fact, this problem exists in quite a few recent
proposals and, therefore, it deserves more research attention in the following
related study.


title: Abstract p-time proof nets for MALL: Conflict nets

abstract:
  This paper presents proof nets for multiplicative-additive linear logic
(MALL), called conflict nets. They are efficient, since both correctness and
translation from a proof are p-time (polynomial time), and abstract, since they
are invariant under transposing adjacent &-rules.
  A conflict net on a sequent is concise: axiom links with a conflict relation.
Conflict nets are a variant of (and were inspired by) combinatorial proofs
introduced recently for classical logic: each can be viewed as a maximal map
(homomorphism) of contractible coherence spaces (P_4-free graphs, or cographs),
from axioms to sequent.
  The paper presents new results for other proof nets: (1) correctness and cut
elimination for slice nets (Hughes / van Glabbeek 2003) are p-time, and (2) the
cut elimination proposed for monomial nets (Girard 1996) does not work. The
subtleties which break monomial net cut elimination also apply to conflict
nets: as with monomial nets, existence of a confluent cut elimination remains
an open question.


title: Towards the topological quantization of classical mechanics

abstract:
  We consider the method of topological quantization for conservative systems
with a finite number of degrees of freedom. Maupertuis' formalism for classical
mechanics provides an appropriate scenario which permit us to adapt the method
of topological quantization, originally formulated for gravitational field
configurations. We show that any conservative system in classical mechanics can
be associated with a principal fiber bundle. As an application of topological
quantization we derive expressions for the topological spectra of some simple
mechanical systems and show that they reproduce the discrete behavior of the
corresponding canonical spectra.


title: Design and Analysis of LDGM-Based Codes for MSE Quantization

abstract:
  Approaching the 1.5329-dB shaping (granular) gain limit in mean-squared error
(MSE) quantization of R^n is important in a number of problems, notably
dirty-paper coding. For this purpose, we start with a binary low-density
generator-matrix (LDGM) code, and construct the quantization codebook by
periodically repeating its set of binary codewords, or them mapped to m-ary
ones with Gray mapping. The quantization algorithm is based on belief
propagation, and it uses a decimation procedure to do the guessing necessary
for convergence. Using the results of a true typical decimator (TTD) as
reference, it is shown that the asymptotic performance of the proposed
quantizer can be characterized by certain monotonicity conditions on the code's
fixed point properties, which can be analyzed with density evolution, and
degree distribution optimization can be carried out accordingly. When the
number of iterations is finite, the resulting loss is made amenable to analysis
through the introduction of a recovery algorithm from ``bad'' guesses, and the
results of such analysis enable further optimization of the pace of decimation
and the degree distribution. Simulation results show that the proposed
LDGM-based quantizer can achieve a shaping gain of 1.4906 dB, or 0.0423 dB from
the limit, and significantly outperforms trellis-coded quantization (TCQ) at a
similar computational complexity.


title:
Foregrounds for redshifted 21 cm studies of reionization: GMRT 153 MHz
  observations

abstract:
  Foreground subtraction is the biggest challenge for future redshifted 21 cm
observations to probe reionization. We use a short GMRT observation at 153 MHz
to characterize the statistical properties of the background radiation across ~
one degree to sub-arcminutes angular scales, and across a frequency band of 5
MHz with 62.5 kHz resolution. The statistic we use is the visibility
correlation function, or equivalently the angular power spectrum C_l. We
present the results obtained from using relatively unsophisticated,
conventional data calibration procedures. We find that even fairly simple
minded calibration allows one to estimate the visibility correlation function
at a given frequency V_2(U,0). From our observations we find that V_2(U,0) is
consistent with foreground model predictions at all angular scales except the
largest ones probed by our observations where the the model predictions are
somewhat in excess. On the other hand the visibility correlation between
different frequencies kappa(U, Delta nu), seems to be much more sensitive to
calibration errors. We find a rapid decline in kappa(U, Delta nu), in contrast
with the prediction of less than 1 % variation across 2.5 MHz. In this case
however, it seems likely that a substantial part of the discrepancy may be due
to limitations of data reduction procedures.


title: Graphene Nanoribbon based T Junctions

abstract:
  Graphene nanoribbons (GNRs) based T junctions were designed and studied in
this paper. These junctions were made up of shoulders (zigzag GNRs) joined with
stems (armchair GNRs). We demonstrated the intrinsic transport properties and
effective boron (or nitrogen) doping of the junctions by using first principles
quantum transport simulation. Several interesting results were found: i) The
I-V characteristics of the pure-carbon T junctions were shown to obey Ohm law
and the electrical conductivity of the junction depends on the height of the
stem sensitively. ii) boron (or nitrogen) doping on the stems doesnt change the
Ohm law of the T junctions, but the result is opposite when doping process
occurs at the shoulders. This feature could make such quasi-2D T junction a
possible candidate for nanoscale junction devices in a 2D network of
nanoelectronic devices in which conducting pathways can be controlled.


title:
Non-Standard Neutrino Physics Probed by Tokai-to-Kamioka-Korea
  Two-Detector Complex

abstract:
  The discovery potentials of non-standard physics (NSP) which might be
possessed by neutrinos are examined by taking a concrete setting of
Tokai-to-Kamioka-Korea (T2KK) two detector complex which receives neutrino
superbeam from J-PARC. We restrict ourselves into \nu_{\mu} and \bar{\nu}_{\mu}
disappearance measurement. We describe here only the non-standard interactions
(NSI) of neutrinos with matter and the quantum decoherence. It is shown in some
favorable cases T2KK can significantly improve the current bounds on NSP. For
NSI, for example, epsilon_{\mu\tau} < 0.03, which is a factor 5 severer than
the current one.


title: Looking for Leptonic CP Violation with Neutrinos

abstract:
  I discuss some theoretical aspects of how to observe leptonic CP violation.
It is divided into two parts, one for CP violation due to Majorana, and the
other more conventional leptonic Kobayashi-Maskawa (KM) phases. In the first
part, I estimate the effect of Majorana phase to observable of neutrinoless
double beta decay experiments by paying a careful attention to the definition
of the atmospheric scale Delta m^2. In the second part, I discuss
Tokai-to-Kamioka-Korea two detector complex which receives neutrino superbeam
from J-PARC as a concrete setting for discovering CP violation due to the KM
phase, as well as resolving mass hierarchy and the theta_{23} octant
degeneracy. A cautionary remark is also given on comparison between various
projects aiming at exploring CP violation and the mass hierarchy.


title:
Magnetorotational instability in protoplanetary discs: The effect of
  dust grains

abstract:
  We investigate the linear growth and vertical structure of the MRI in
protoplanetary discs when dust grains are well mixed with the gas over the
entire disc thickness. All the grains have the same radius (a = 0.1, 1 or 3
micron) and constitute 1 % of the total mass of the gas. Solutions are obtained
at R = 5 and 10 AU for a minimum-mass solar nebula model and different choices
of the initially vertical magnetic field strength (B), configuration of the
diffusivity tensor and grain sizes. We find that when no grains are present, or
they are > 1 micron, the midplane remains magnetically coupled for B up to a
few gauss at both radii. In contrast, when a population of small grains (a =
0.1 micron) is present, the disc is magnetically inactive for z/H < 2 and only
B < 50 mG couple to the fluid. At 5 AU, Ohmic diffusion dominates for z/H < 1
when B < a few mG, irrespective of the properties of the grain population.
Conversely, at 10 AU this diffusion term is unimportant in all the scenarios
studied here. For z/H > 5, ambipolar diffusion is severe and prevents the field
from coupling to the gas for all B. Hall diffusion is dominant for a wide range
of field strengths at both radii when dust grains are present. The growth rate,
wavenumber and range of magnetic field strengths for which MRI-unstable modes
exist are all drastically diminished when dust grains are present, particularly
when they are small (a ~ 0.1 micron). We conclude that in protoplanetary discs,
the magnetic field is able to couple to the gas and shear over a wide range of
fluid conditions even when small dust grains are well mixed with the gas.
Despite the low magnetic coupling, MRI modes grow for an extended range of
magnetic field strengths and Hall diffusion largely determines the properties
of the perturbations in the inner regions of the disc (abridged).


title: Helicity Entanglement of Moving Bodies

abstract:
  We investigate the Lorentz transformation of the reduced helicity density
matrix for a pair of massive spin 1/2 particles. The corresponding Wootters
concurrence shows no invariant meaning, which implies that we can generate
helicity entanglement simply by the transformation from one reference frame to
another. The difference between the helicity and spin case is also discussed.


title: Weak approximation on del Pezzo surfaces of degree 1

abstract:
  We study del Pezzo surfaces of degree 1 of the form w^2 = z^3 + Ax^6 + By^6
in the weighted projective space P_k(1,1,2,3), where k is a perfect field of
characteristic not 2 or 3 and A,B \in k^*. Over a number field, we exhibit an
infinite family of (minimal) counterexamples to weak approximation amongst
these surfaces, via a Brauer-Manin obstruction.


title: Distinguishing Modified Gravity from Dark Energy

abstract:
  The acceleration of the universe can be explained either through dark energy
or through the modification of gravity on large scales. In this paper we
investigate modified gravity models and compare their observable predictions
with dark energy models. Modifications of general relativity are expected to be
scale-independent on super-horizon scales and scale-dependent on sub-horizon
scales. For scale-independent modifications, utilizing the conservation of the
curvature scalar and a parameterized post-Newtonian formulation of cosmological
perturbations, we derive results for large scale structure growth, weak
gravitational lensing, and cosmic microwave background anisotropy. For
scale-dependent modifications, inspired by recent $f(R)$ theories we introduce
a parameterization for the gravitational coupling $G$ and the post-Newtonian
parameter $\gamma$. These parameterizations provide a convenient formalism for
testing general relativity. However, we find that if dark energy is generalized
to include both entropy and shear stress perturbations, and the dynamics of
dark energy is unknown a priori, then modified gravity cannot in general be
distinguished from dark energy using cosmological linear perturbations.


title:
Spectral Properties of Prompt Emission of Four Short Gamma-Ray Bursts
  Observed by the Suzaku-WAM and the Konus-Wind

abstract:
  We have performed a joint analysis of prompt emission from four bright short
gamma-ray bursts (GRBs) with the Suzaku-WAM and the Konus-Wind experiments.
This joint analysis allows us to investigate the spectral properties of
short-duration bursts over a wider energy band with a higher accuracy. We find
that these bursts have a high E$_{\rm peak}$, around 1 MeV and have a harder
power-law component than that of long GRBs. However, we can not determine
whether these spectra follow the cut-off power-law model or the Band model. We
also investigated the spectral lag, hardness ratio, inferred isotropic
radiation energy and existence of a soft emission hump, in order to classify
them into short or long GRBs using several criteria, in addition to the burst
duration. We find that all criteria, except for the existence of the soft hump,
support the fact that our four GRB samples are correctly classified as
belonging to the short class. In addition, our broad-band analysis revealed
that there is no evidence of GRBs with a very large hardness ratio, as seen in
the BATSE short GRB sample, and that the spectral lag of our four short GRBs is
consistent with zero, even in the MeV energy band, unlike long GRBs. Although
our short GRB samples are still limited, these results suggest that the
spectral hardness of short GRBs might not differ significantly from that of
long GRBs, and also that the spectral lag at high energies could be a strong
criterion for burst classification.


title: Parametrized Post-Friedmann Signatures of Acceleration in the CMB

abstract:
  We extend the covariant, parametrized post-Friedmann treatment of cosmic
acceleration from modified gravity to an arbitrary admixture of matter,
radiation, relativistic components and spatial curvature. Explicit expressions
in the comoving, Newtonian and synchronous gauges facilitate the adaptation of
Einstein-Boltzmann codes for solving CMB and matter perturbations in the linear
regime. Using a comoving gauge code, we study the effect of metric evolution on
the CMB through the integrated Sachs-Wolfe effect. Modified gravity can alter
the low multipole spectrum, including lowering the power in the quadrupole.
From a principal component description of the primary metric ratio parameter,
we obtain general constraints from WMAP on modified gravity models of the
acceleration.


title:
Phase transition for black holes with scalar hair and topological black
  holes

abstract:
  We study phase transitions between black holes with scalar hair and
topological black holes in asymptotically anti-de Sitter spacetimes. As the
ground state solutions, we introduce the non-rotating BTZ black hole in three
dimensions and topological black hole with hyperbolic horizon in four
dimensions. For the temperature matching only, we show that the phase
transition between black hole with scalar hair (Martinez-Troncoso-Zanelli black
hole) and topological black hole is second-order by using differences between
two free energies. However, we do not identify what order of the phase
transition between scalar and non-rotating BTZ black holes occurs in three
dimensions, although there exists a possible decay of scalar black hole to
non-rotating BTZ black hole.


title: Grain Sedimentation in a Giant Gaseous Protoplanet

abstract:
  We present a calculation of the sedimentation of grains in a giant gaseous
protoplanet such as that resulting from a disk instability of the type
envisioned by Boss (1998). Boss (1998) has suggested that such protoplanets
would form cores through the settling of small grains. We have tested this
suggestion by following the sedimentation of small silicate grains as the
protoplanet contracts and evolves. We find that during the course of the
initial contraction of the protoplanet, which lasts some $4\times 10^5$ years,
even very small (> 1 micron) silicate grains can sediment to create a core both
for convective and non-convective envelopes, although the sedimentation time is
substantially longer if the envelope is convective, and grains are allowed to
be carried back up into the envelope by convection. Grains composed of organic
material will mostly be evaporated before they get to the core region, while
water ice grains will be completely evaporated. These results suggest that if
giant planets are formed via the gravitational instability mechanism, a small
heavy element core can be formed due to sedimentation of grains, but it will be
composed almost entirely of refractory material. Including planetesimal
capture, we find core masses between 1 and 10 M$_{\oplus}$, and a total high-Z
enhancement of ~40 M$_{\oplus}$. The refractories in the envelope will be
mostly water vapor and organic residuals.


title: Spectral signatures of modulated d-wave superconducting phases

abstract:
  We calculate within a mean-field theory the spectral signatures of various
striped d-wave superconducting phases. We consider both in-phase and anti-phase
modulations of the superconducting order across a stripe boundary, and the
effects of coexisting inhomogeneous orders, including spin stripes, charge
stripes, and modulated d-density-wave. We find that the anti-phase modulated
d-wave superconductor exhibits zero-energy spectral weight, primarily along
extended arcs in momentum space. Concomitantly, a Fermi surface appears and
typically includes both open segments and closed pockets. When weak homogeneous
superconductivity is also present the Fermi surface collapses onto nodal
points. Among them are the nodal points of the homogeneous d-wave
superconductor, but others typically exist at positions which depend on the
details of the modulation and the band structure. Upon increasing the amplitude
of the constant component these additional points move towards the edges of the
reduced Brillouin zone where they eventually disappear. The above signatures
are also manifested in the density of states of the clean, and the disordered
system. While the presence of coexisting orders changes some details of the
spectral function, we find that the evolution of the Fermi-surface and the
distribution of the low-energy spectral weight are largely unaffected by them.


title: Discontinuous Jamming Transitions in Soft Materials

abstract:
  Many systems in nature exhibit transitions between fluid-like states and
solid-like states, or "jamming transitions". There is a strong theoretical
foundation for understanding equilibrium phase transitions that involve
solidification, or jamming. Other jamming transitions, such as the glass
transition, are less well-understood. The jamming phase diagram has been
proposed to unify the description of equilibrium phase transitions, the glass
transitions, and other non-equilibrium jamming transitions. As with equilibrium
phase transitions, which can either be first order (discontinuous in a relevant
order parameter) or second order (continuous), one would expect that
generalized jamming transitions can be continuous or discontinuous. In studies
of flow in complex fluids, there is a wide range of evidence for discontinuous
transitions, mostly in the context of shear localization, or shear banding. In
this paper, I review the experimental evidence for discontinuous transitions. I
focus on systems in which there is a discontinuity in the rate of strain
between two, coexisting states: one in which the material is flowing and the
other in which it is solid-like.


title:
Dilaton Cosmology, Noncommutativity and Generalized Uncertainty
  Principle

abstract:
  The effects of noncommutativity and of the existence of a minimal length on
the phase space of a dilatonic cosmological model are investigated. The
existence of a minimum length, results in the Generalized Uncertainty Principle
(GUP), which is a deformed Heisenberg algebra between the minisuperspace
variables and their momenta operators. We extend these deformed commutating
relations to the corresponding deformed Poisson algebra. For an exponential
dilaton potential, the exact classical and quantum solutions in the commutative
and noncommutative cases, and some approximate analytical solutions in the case
of GUP, are presented and compared.


title:
Measurement of the ratio B(D0->pi+pi-pi0)/B(D0->K-pi+pi0) and the
  time-integrated CP asymmetry in D0->pi+pi-pi0

abstract:
  We report a high-statistics measurement of the relative branching fraction
B(D0->pi+pi-pi0)/B(D0->K-pi+pi0) using a 532 fb^{-1} data sample collected with
the Belle detector at the KEKB asymmetric-energy e+e- collider. The measured
value of the relative branching fraction is B(D0->pi+pi-pi0)/B(D0->K-pi+pi0) =
(10.12 +/- 0.04(stat) +/- 0.18(syst))x10^{-2} which has an accuracy comparable
to the world average. We also present a measurement of the time-integrated CP
asymmetry in D0->pi+pi-pi0 decay. The result, A_{CP} = (0.43 +/- 1.30)%, shows
no significant CP violation.


title:
Subluminal to superluminal propagation of an optical pulse in an
  f-deformed Bose- Einstein condensate

abstract:
  In this paper, we investigate the propagation of a weak optical probe pulse
in an f-deformed Bose- Einstein condensate (BEC) of a gas with the -type three-
level atoms in the electromagnetically induced transparency (EIT) regime. We
use an f- deformed generalization of an effective two- level quantum model of
the three- level configuration in which the Gardiner phonon operators for BEC
are deformed by an operator- valued function, f(n), of the particle- number
operator n. With making use of the quantum approach of the angular momentum
theory we obtain the eigenvalues and eigenfunctions of the system up to first
order approximation. We consider the collisions between the atoms as a special
kind of f- deformation. The collision rate k is regarded as the deformation
parameter and light propagation in the deformed BEC is analyzed. In particular,
we show that the absorptive and dispersive properties of the deformed
condensate can be controlled effectively by changing the deformation parameter
k and the total number of atoms. We find that by increasing the value of k the
group velocity of the probe pulse changes, through deformed condensate, from
subluminal to superluminal.


title: Perturbing singular solutions of the Gelfand problem

abstract:
  he equation $-\Delta u = \lambda e^u$ posed in the unit ball $B \subseteq
\R^N$, with homogeneous Dirichlet condition $u|_{\partial B} = 0$, has the
singular solution $U=\log\frac1{|x|^2}$ when $\lambda = 2(N-2)$. If $N\ge 4$ we
show that under small deformations of the ball there is a singular solution
$(u,\lambda)$ close to $(U,2(N-2))$. In dimension $N\ge 11$ it corresponds to
the extremal solution -- the one associated to the largest $\lambda$ for which
existence holds. In contrast, we prove that if the deformation is sufficiently
large then even when $N\ge 10$, the extremal solution remains bounded in many
cases.


title:
Perturbations of the seismic reflectivity of a fluid-saturated
  depth-dependent poro-elastic medium

abstract:
  Analytical formulas are derived to compute the first-order effects produced
by plane inhomogeneities on the point source seismic response of a fluid-filled
stratified porous medium. The derivation is achieved by a perturbation analysis
of the poro-elastic wave equations in the plane-wave domain using the Born
approximation. This approach yields the Fr\'echet derivatives of the P -- SV -
and SH-wave responses in terms of the Green's functions of the unperturbed
medium. The accuracy and stability of the derived operators are checked by
comparing, in the time-distance domain, differential seismograms computed from
these analytical expressions with complete solutions obtained by introducing
discrete perturbations into the model properties. For vertical and horizontal
point forces, it is found that the Fr\'echet derivative approach is remarkably
accurate for small and localized perturbations of the medium properties which
are consistent with the Born approximation requirements. Furthermore, the
first-order formulation appears to be stable at all source-receiver offsets.
The porosity, consolidation parameter, solid density and mineral shear modulus
emerge as the most sensitive parameters in forward and inverse modeling
problems. Finally, the Amplitude-Versus-Angle response of a thin layer shows
strong coupling effects between several model parameters.


title: Staircase Macdonald polynomials and the $q$-Discriminant

abstract:
  We prove that a $q$-deformation $\Disc k\X q$ of the powers of the
discriminant is equal, up to a normalization, to a specialization of a
Macdonald polynomial indexed by a staircase partition. We investigate the
expansion of $\Disc k\X q$ on different basis of symmetric functions. In
particular, we show that its expansion on the monomial basis can be explicitly
described in terms of standard tableaux and we generalize a result of
King-Toumazet-Wybourne about the expansion of the $q$-discriminant on the Schur
basis.


title:
Schubert presentation of the integral cohomology ring of the flag
  manifolds G/T

abstract:
  Let G be a compact connected Lie group with a maximal torus T\subsetG. In the
context of Schubert calculus we obtain a canonical presentation for the
integral cohomology ring H^{\ast}(G/T) of the complete flag manifold G/T.
  The result have been applied in [15] to construct the integral cohomology
ring H^{\ast}(G) in terms of Schubert classes on G/T, and in [16] to determine
the structure of the modp cohomology H^{\ast}(G;F_{p}) as a Hopf algebra over
the Steenrod algebra.


title: Stable solutions for the bilaplacian with exponential nonlinearity

abstract:
  Let $\lambda^*>0$ denote the largest possible value of $\lambda$ such that
\begin{align*} \left\{\begin{aligned} \Delta^2 u & = \la e^u && \text{in $B $}
u &= \pd{u}{n} = 0 && \text{on $ \pa B $} \end{aligned} \right. \end{align*}
has a solution, where $B$ is the unit ball in $\R^N$ and $n$ is the exterior
unit normal vector. We show that for $\lambda=\lambda^*$ this problem possesses
a unique {\em weak} solution $u^*$. We prove that $u^*$ is smooth if $N\le 12$
and singular when $N\ge 13$, in which case $ u^*(r) = - 4 \log r + \log
(8(N-2)(N-4) / \lambda^*) + o(1)$ as $r\to 0$. We also consider the problem
with general constant Dirichlet boundary conditions.


title:
Heat transport by Dirac fermions in normal/superconducting graphene
  junctions

abstract:
  We study heat transport in normal/superconducting graphene junctions. We find
that while the thermal conductance displays the usual exponential dependence on
temperature, reflecting the s-wave symmetry of the superconductor, it exhibits
an unusual oscillatory dependence on the potential height or the length of the
barrier region. This oscillatory dependence stems from the emergent low-energy
relativistic nature of fermions in graphene, essentially different from the
result in conventional normal metal/superconductor junctions.


title: Optimal metabolic pathway activation

abstract:
  This paper deals with temporal enzyme distribution in the activation of
biochemical pathways. Pathway activation arises when production of a certain
biomolecule is required due to changing environmental conditions. Under the
premise that biological systems have been optimized through evolutionary
processes, a biologically meaningful optimal control problem is posed. In this
setup, the enzyme concentrations are assumed to be time dependent and
constrained by a limited overall enzyme production capacity, while the
optimization criterion accounts for both time and resource usage.
  Using geometric arguments we establish the bang-bang nature of the solution
and reveal that each reaction must be sequentially activated in the same order
as they appear in the pathway. The results hold for a broad range of enzyme
dynamics which includes, but is not limited to, Mass Action, Michaelis-Menten
and Hill Equation kinetics.


title: Atom cooling with an atom-optical diode on a ring

abstract:
  We propose a method to cool atoms on a ring by combining an atom diode -a
laser valve for one-way atomic motion which induces robust internal state
excitation- and a trap. We demonstrate numerically that the atom is efficiently
slowed down at each diode crossing, and it is finally trapped when its velocity
is below the trap threshold.


title:
Entanglement renormalization in free bosonic systems: real-space versus
  momentum-space renormalization group transforms

abstract:
  The ability of entanglement renormalization (ER) to generate a proper
real-space renormalization group (RG) flow in extended quantum systems is
analysed in the setting of harmonic lattice systems in D=1 and D=2 spatial
dimensions. A conceptual overview of the steps involved in momentum-space RG is
provided and contrasted against the equivalent steps in the real-space setting.
The real-space RG flow, as generated by ER, is compared against the exact
results from momentum-space RG, including an investigation of a critical fixed
point and the effect of relevant and irrelevant perturbations.


title:
Observing the strong gravity regime of accreting black holes with
  Simbol-X

abstract:
  The X-ray reflection features of irradiated accretion disks around black
holes enable us to probe the effects of strong gravity. We investigate to which
precision the reflection signs, i.e. the iron K-line and the Comptonized hump,
can be observed with Simbol-X for nearby Seyfert galaxies. The simulations
presented include accurate computations of the local reprocessed spectra and
modifications due to general relativistic effects in the vicinity of the black
hole. We discuss the impact of global black hole parameters and of the
irradiation pattern of the disk on the resulting spectra as they will be
detected by the Simbol-X mission.


title: The two hybrid B-type pulsators: Nu Eridani and 12 Lacertae

abstract:
  The rich oscillation spectra determined for the two stars, Nu Eridani and 12
Lacertae, present an interesting challenge to stellar modelling. The stars are
hybrid objects showing a number of modes at frequencies typical for Beta Cep
stars but also one mode at frequency typical for SPB stars. We construct
seismic models of these stars considering uncertainties in opacity and element
distribution. We also present estimate of the interior rotation rate and
address the matter of mode excitation.
  We use both the OP and OPAL opacity data and find significant difference in
the results. Uncertainty in these data remains a major obstacle in precise
modelling of the objects and, in particular, in estimating the overshooting
distance. We find evidence for significant rotation rate increase between
envelope and core in the two stars.
  Instability of low-frequency g-modes was found in seismic models of Nu Eri
built with the OP data, but at frequencies higher than those measured in the
star. No such instability was found in models of 12 Lac. We do not have yet a
satisfactory explanation for low frequency modes. Some enhancement of opacity
in the driving zone is required but we argue that it cannot be achieved by the
iron accumulation, as it has been proposed.


title: Super-Solar Metallicity in Weak Mg II Absorption Systems at z ~ 1.7

abstract:
  Through photoionization modeling, constraints on the physical conditions of
three z ~ 1.7 single-cloud weak Mg II systems (W_r(2796) < 0.3A) are derived.
Constraints are provided by high resolution R = 45,000, high signal-to-noise
spectra of the three quasars HE0141-3932, HE0429-4091, and HE2243-6031 which we
have obtained from the ESO archive of VLT/UVES. Results are as follows:
  (1) The single-cloud weak Mg II absorption in the three z ~ 1.7 systems is
produced by clouds with ionization parameters of -3.8 < logU < -2.0 and sizes
of 1-100 pc.
  (2) In addition to the low-ionization phase Mg II clouds, all systems need an
additional 1-3 high-ionization phase C IV clouds within 100 km/s of the Mg II
component. The ionization parameters of the C IV phases range from -1.9 < logU
< -1.0, with sizes of tens of parsecs to kiloparsecs.
  (3) Two of the three single-cloud weak Mg II absorbers have near-solar or
super-solar metallicities, if we assume a solar abundance pattern. Although
such large metallicities have been found for z < 1 weak Mg II absorbers, these
are the first high metallicities derived for such systems at higher redshifts.
  (4) Two of the three weak Mg II systems also need additional low-metallicity,
broad Lya absorption lines, offset in velocity from the metal-line absorption,
in order to reproduce the full Lya profile.
  (5) Metallicity in single-cloud weak Mg II systems are more than an order of
magnitude larger than those in Damped Lya systems at z ~ 1.7. In fact, there
appears to be a gradual decrease in metallicity with increasing N(HI), from
these, the most metal-rich Lya forest clouds, to Lyman limit systems, to
sub-DLAs, and finally to the DLAs.


title: Quasiattractor dynamics of lambda-phi^4-inflation

abstract:
  At high e-foldings of expansion, the inflation with the quartic potential
exhibits the parametric attractor governed by the slowly running Hubble rate.
This quasiattractor simplifies the analysis of predictions for the
inhomogeneity generated by the quantum fluctuations of inflaton. The method
reveals the connection of inflation e-folding with general parameters of
preheating regime in various scenarios and observational data.


title:
The effect of dressing on high-order harmonic generation in vibrating
  H$_2$ molecules

abstract:
  We develop the strong-field approximation for high-order harmonic generation
in hydrogen molecules, including the vibrational motion and the laser-induced
coupling of the lowest two Born-Oppenheimer states in the molecular ion that is
created by the initial ionization of the molecule. We show that the field
dressing becomes important at long laser wavelengths ($\approx 2 \mu$m),
leading to an overall reduction of harmonic generation and modifying the ratio
of harmonic signals from different isotopes.


title:
Eulerian calculus for the displacement convexity in the Wasserstein
  distance

abstract:
  In this paper we give a new proof of the (strong) displacement convexity of a
class of integral functionals defined on a compact Riemannian manifold
satisfying a lower Ricci curvature bound. Our approach does not rely on
existence and regularity results for optimal transport maps on Riemannian
manifolds, but it is based on the Eulerian point of view recently introduced by
Otto-Westdickenberg and on the metric characterization of the gradient flows
generated by the functionals in the Wasserstein space.


title: Coding on countably infinite alphabets

abstract:
  This paper describes universal lossless coding strategies for compressing
sources on countably infinite alphabets. Classes of memoryless sources defined
by an envelope condition on the marginal distribution provide benchmarks for
coding techniques originating from the theory of universal coding over finite
alphabets. We prove general upper-bounds on minimax regret and lower-bounds on
minimax redundancy for such source classes. The general upper bounds emphasize
the role of the Normalized Maximum Likelihood codes with respect to minimax
regret in the infinite alphabet context. Lower bounds are derived by tailoring
sharp bounds on the redundancy of Krichevsky-Trofimov coders for sources over
finite alphabets. Up to logarithmic (resp. constant) factors the bounds are
matching for source classes defined by algebraically declining (resp.
exponentially vanishing) envelopes. Effective and (almost) adaptive coding
techniques are described for the collection of source classes defined by
algebraically vanishing envelopes. Those results extend ourknowledge concerning
universal coding to contexts where the key tools from parametric inference


title: Bubble effect on Kelvin-Helmholtz' instability

abstract:
  We derive boundary conditions at interfaces (contact discontinuities) for a
class of Lagrangian models describing, in particular, bubbly flows. We use
these conditions to study Kelvin-Helmholtz' instability which develops in the
flow of two superposed layers of a pure incompressible fluid and a fluid
containing gas bubbles, co-flowing with different velocities. We show that the
presence of bubbles in one layer stabilizes the flow in some intervals of wave
lengths.


title: Non-linear waves in fluids near the critical point

abstract:
  A non-linear model associated with a Landau-Ginzburg-like behavior in mean
field approximation forecasts phase transition waves and solitary kinks near
the critical point. The behavior of isothermal waves is different of the one of
isentropic waves as well in conservative cases as in dissipative cases.


title: Duality transformation of non-Abelian tensor gauge fields

abstract:
  For non-Abelian tensor gauge fields we have found an alternative form of
duality transformation, which has the property that the direct and the inverse
transformations coincide. This duality transformation has the desired property
that the direct and the inverse transformations map Lagrangian forms into each
other.


title:
Notes on the bunching peak of g(2) functions for correlated photons from
  single quantum dots

abstract:
  Second-order correlation functions for photon pulses associated with
exciton-biexciton cascades are theoretically derived. A finite efficiency in
photon detection and statistical distribution in exciton numbers are taken into
account. It is found that the bunching peak height of photon statistics
(g(2)(0)) depends on the mean number of excitons, N, and significant bunching
is only detectable at very low excitation, N<<2.


title: Quadratic Form Expansions for Unitaries

abstract:
  We introduce techniques to analyze unitary operations in terms of quadratic
form expansions, a form similar to a sum over paths in the computational basis
when the phase contributed by each path is described by a quadratic form over
$\mathbb R$. We show how to relate such a form to an entangled resource akin to
that of the one-way measurement model of quantum computing. Using this, we
describe various conditions under which it is possible to efficiently implement
a unitary operation U, either when provided a quadratic form expansion for U as
input, or by finding a quadratic form expansion for U from other input data.


title: A Resummable beta-Function for Massless QED

abstract:
  Within the set of schemes defined by generalized, manifestly gauge invariant
exact renormalization groups for QED, it is argued that the beta-function in
the four dimensional massless theory cannot possess any nonperturbative power
corrections. Consequently, the perturbative expression for the beta-function
must be resummable. This argument cannot be extended to flows of the other
couplings or to the anomalous dimension of the fermions and so perturbation
theory does not define a unique trajectory in the critical surface of the
Gaussian fixed point. Thus, resummability of the beta-function is not
inconsistent with the expectation that a non-trivial fixed point does not
exist.


title: Assisted Tunneling of a metastable state between barriers

abstract:
  The assisted tunneling of a metastable state between barriers is investigated
analytically by means of a simplified one dimensional model. A time dependent
perturbation changes the pole spectrum of the wave function introducing a
larger decay constant. New insights about the decay of a metastable state are
found. The scheme is exemplified for parameters corresponding to the nuclear
process of $\alpha$ decay.


title:
Nambu-Goto Like Action for the AdS_5 x S^5 Superstrings in the
  Generalized Light-Cone Gauge

abstract:
  We reinvestigate the kappa-symmetry-fixed Green-Schwarz action in the AdS_5 x
S^5 background in a version of the light-cone gauge. In the generalized
light-cone gauge, the action has been written in the phase space variables. We
convert it into the standard action written in terms of the fields and their
derivatives. We obtain a Nambu-Goto type action which has the correct
flat-space limit.


title: Hard X-ray Emission from Magnetars : A Case Study for Simbol X

abstract:
  The magnetar model involves an isolated neutron star with a very high
magnetic field (B~10^14-10^15 G), and is invoked to explain the emission
processes of two classes of sources, the Anomalous X-ray Pulsars (AXPs) and the
Soft Gamma-Ray Repeaters (SGRs). Five of them have been recently identified to
be persistent sources in the hard X-ray band (20-200 keV). AXPs, in particular,
present the hardest known persistent spectra in the hard X/soft gamma-ray
energy range. The broad band modeling of their spectra still suffers from the
non-simultaneity of the observations and from a lack of sensitivity above 20
keV. We present the Simbol X simulated observations of these objects and show
that that this mission could surely help to disentangle the contribution of the
different spectral components, and to understand how they contribute to the
secular flux variations observed in these sources.


title: Charge and Spin Currents Generated by Dynamical Spins

abstract:
  We demonstrate theoretically that a charge current and a spin current are
generated by spin dynamics in the presence of spin-orbit interaction in the
perturbative regime. We consider a general spin-orbit interaction including the
spatially inhomogeneous case. Spin current due to spin damping is identified as
one origin of generated charge current, but other contributions exist, such as
the one due to an induced conservative field and the one arising from the
inhomogeneity of spin-orbit interaction.


title: Integral Field Spectroscopy of Blue Compact Dwarf Galaxies

abstract:
  We present results on integral-field optical spectroscopy of five luminous
Blue Compact Dwarf galaxies. The data were obtained using the fiber system
INTEGRAL attached at the William Herschel telescope. The galaxies Mrk 370, Mrk
35, Mrk 297, Mrk 314 and III Zw 102 were observed. The central 33"x29" regions
of the galaxies were mapped with a spatial resolution of 2"/spaxel, except for
Mrk 314, in which we observed the central 16"x12" region with a resolution of
0.9"/spaxel$. We use high-resolution optical images to isolate the star-forming
knots in the objects; line ratios, electron densities and oxygen abundances in
each of these regions are computed. We build continuum and emission-line
intensity maps as well as maps of the most relevant line ratios: [OIII]5007\Hb,
[NII]6584\Ha, and Ha\Hb, which allow us to obtain spatial information on the
ionization structure and mechanisms. We also derive the gas velocity field from
the Ha and [OIII]5007 emission lines.
  We find that all the five galaxies are in the high end of the metallicity
range of Blue Compact Dwarf galaxies, with oxygen abundances varying from
Z\sun~0.3 to Z\sun~1.5. The objects show HII-like ionization in the whole field
of view, except the outer regions of IIIZw102 whose large [NII]6584/Ha values
suggest the presence of shocks. The five galaxies display inhomogeneous
extinction patterns, and three of them have high Ha/Hb ratios, indicative of a
large dust content; all galaxies display complex, irregular velocity fields in
their inner regions.


title: The Construction of the CMS Silicon Strip Tracker

abstract:
  The CMS Silicon Strip tracker is a very large scale tracker entirely based on
silicon strip detectors technology. The integration of modules, electronics,
mechanics and services has been completed within the last eighteen months;
first large standalone sub-structures (shells, disks, rods, petals depending on
the tracker subdetector) have been integrated and verified; then they have been
brought together into the final configuration. The CMS silicon tracker design
and its construction is reviewed with particular emphasis on the procedures and
quality checks deployed to successfully assembly several silicon strip modules
and all ancillary components into these large sub-structures. An overview of
the results and the lesson learned from the tracker integration are given, also
in terms of failure and damage rates.