title: Lyman Alpha Driven Outflows Around Star Forming Galaxies

abstract:
  We present accurate Monte-Carlo calculations of Lyman Alpha (hereafter Lya)
radiation pressure in a range of models which represent galaxies during various
epochs of our Universe. We show that the radiation force that Lya photons exert
on hydrogen gas in the neutral intergalactic medium (IGM), that surrounds
minihalos that host the first stars, may exceed gravity by orders of magnitude
and drive supersonic winds. Lya radiation pressure may also dominate over
gravity in the neutral IGM that surrounds the HII regions produced by the first
galaxies. However, the radiation force is likely too weak to result in
supersonic outflows in this case. Furthermore, we show that Lya radiation
pressure may drive outflows in the interstellar medium of star forming galaxies
that reach hundreds of km/s. This mechanism could also operate at lower
redshifts z<6, and may have already been indirectly detected in the spectral
line shape of observed Lya emission lines.


title:
Milliarcsecond angular resolution of reddened stellar sources in the
  vicinity of the Galactic Center

abstract:
  For the first time, the lunar occultation technique has been employed on a
very large telescope in the near-IR with the aim of achieving systematically
milliarcsecond resolution on stellar sources.
  We have demonstrated the burst mode of the ISAAC instrument, using a fast
read-out on a small area of the detector to record many tens of seconds of data
at a time on fields of few squared arcsec. We have used the opportunity to
record a large number of LO events during a passage of the Moon close to the
Galactic Center in March 2006. We have developed a data pipeline for the
treatment of LO data, including the automated estimation of the main data
analysis parameters using a wavelet-based method, and the preliminary fitting
and plotting of all light curves.
  We recorded 51 LO events over about four hours. Of these, 30 resulted of
sufficient quality to enable a detailed fitting. We detected two binaries with
subarcsec projected separation and three stars with a marginally resolved
angular diameter of about 2 mas. Two more SiO masers, were found to be resolved
and in one case we could recover the brightness profile of the extended
emission, which is well consistent with an optically thin shell. The remaining
unresolved stars were used to characterize the performance of the method.
  The LO technique at a very large telescope is a powerful and efficient method
to achieve angular resolution, sensitivity, and dynamic range that are among
the best possible today with any technique. The selection of targets is
naturally limited and LOs are fixed-time events, however each observation
requires only a few minutes including overheads. As such, LOs are ideally
suited to fill small gaps of idle time between standard observations.


title:
The Biermann Battery in Cosmological MHD Simulations of Population III
  Star Formation

abstract:
  We report the results of the first self-consistent three-dimensional adaptive
mesh refinement magnetohydrodynamical simulations of Population III star
formation including the Biermann Battery effect. We find that the Population
III stars formed including this effect are both qualitatively and
quantitatively similar to those from hydrodynamics-only (non-MHD) cosmological
simulations. We observe peak magnetic fields of ~10^-9 G in the center of our
star-forming halo at z ~ 17.55. The magnetic fields created by the Biermann
Battery effect are predominantly formed early in the evolution of the
primordial halo at low density and large spatial scales, and then grow through
compression and by shear flows. The fields seen in this calculation are never
large enough to be dynamically important (with beta >= 10^{15} at all times),
and should be considered the minimum possible fields in existence during
Population III star formation, and may be seed fields for the stellar dynamo or
the magnetorotational instability at higher densities and smaller spatial
scales.


title: On Endogenous Reconfiguration in Mobile Robotic Networks

abstract:
  In this paper, our focus is on certain applications for mobile robotic
networks, where reconfiguration is driven by factors intrinsic to the network
rather than changes in the external environment. In particular, we study a
version of the coverage problem useful for surveillance applications, where the
objective is to position the robots in order to minimize the average distance
from a random point in a given environment to the closest robot. This problem
has been well-studied for omni-directional robots and it is shown that optimal
configuration for the network is a centroidal Voronoi configuration and that
the coverage cost belongs to $\Theta(m^{-1/2})$, where $m$ is the number of
robots in the network. In this paper, we study this problem for more realistic
models of robots, namely the double integrator (DI) model and the differential
drive (DD) model. We observe that the introduction of these motion constraints
in the algorithm design problem gives rise to an interesting behavior. For a
\emph{sparser} network, the optimal algorithm for these models of robots mimics
that for omni-directional robots. We propose novel algorithms whose
performances are within a constant factor of the optimal asymptotically (i.e.,
as $m \to +\infty$). In particular, we prove that the coverage cost for the DI
and DD models of robots is of order $m^{-1/3}$. Additionally, we show that, as
the network grows, these novel algorithms outperform the conventional
algorithm; hence necessitating a reconfiguration in the network in order to
maintain optimal quality of service.


title: Gravitational radiation of generic isolated horizons

abstract:
  From the similarity between null infinity and horizons, we show how to set up
proper frames near generic isolated horizons. The asymptotic expansion and
reference spin frame are used to study gravitational radiation near generic
isolated horizons and it turns out that the news function appears on
non-expanding horizon. We also verify that the surface gravity is constant on
(weakly) isolated horizon. The corresponding conserved quantities and relevant
asymptotic symmetry groups which allow gravitational radiation of generic
isolated horizons are obtained from asymptotic expansion.


title:
Milliarcsecond angular resolution of reddened stellar sources in the
  vicinity of the Galactic Center. II. Additional observations

abstract:
  We present lunar occultation observations obtained in August 2006 with the
recently demonstrated burst mode of the ISAAC instrument at the ESO VLT. The
results presented here follow the previously reported observations carried out
in March 2006 on a similar but unrelated set of sources.
  Interstellar extinction in the inner regions of the galactic bulge amounts to
tens of magnitudes at visual wavelengths. As a consequence, the majority of
sources in that area are poorly studied and large numbers of potentially
interesting sources such as late-type giants with circumstellar shells, stellar
masers, infrared stars, remain excluded from the typical investigations which
are carried out in less problematic regions. Also undetected are a large
numbers of binaries. By observing LO events in this region, we gain the means
to investigate at least a selected number of sources with an unprecedented
combination of sensitivity and angular resolution. The LO technique permits to
achieve mas resolution with a sensitivity of K~12mag at a very large telescope.
We have used the opportunity of a favorable passage of the Moon over a crowded
region in the general direction of the Galactic Center to observe 78 LO events
of heavily reddened stellar sources. We have detected six new binary and one
triple star, with typical projected separation of ~0.01". We have also detected
the compact circumstellar emission around one maser and one central star of a
planetary nebula. Additionally we have measured the diameter and/or
circumstellar shell of two carbon stars and other IR sources. In agreement with
our previous result, we conclude that lunar occultations in fast read-out mode
on a detector subwindow at an 8m-class telescope can achieve an angular
resolution close to 0.001" with a sensitivity K~12mag.


title:
Getting More For Your Money: Identifying and Confirming Long-Period
  Planets with Kepler

abstract:
  Kepler will monitor enough stars that it is likely to detect single transits
of planets with periods longer than the mission lifetime. We show that by
combining the Kepler photometry of such transits with precise radial velocity
(RV) observations taken over ~3 months, and assuming circular orbits, it is
possible to estimate the periods of these transiting planets to better than 20%
(for planets with radii greater than that of Neptune) and the masses to within
a factor of 2 (for planet masses m_p > M_Jup). We also explore the effects of
eccentricity on our estimates of these uncertainties.


title:
The Barbero-Immirzi Parameter as a Scalar Field: K-Inflation from Loop
  Quantum Gravity?

abstract:
  We consider a loop-quantum gravity inspired modification of general
relativity, where the Holst action is generalized by making the Barbero-Immirzi
(BI) parameter a scalar field, whose value could be dynamically determined. The
modified theory leads to a non-zero torsion tensor that corrects the field
equations through quadratic first-derivatives of the BI field. Such a
correction is equivalent to general relativity in the presence of a scalar
field with non-trivial kinetic energy. This stress-energy of this field is
automatically covariantly conserved by its own dynamical equations of motion,
thus satisfying the strong equivalence principle. Every general relativistic
solution remains a solution to the modified theory for any constant value of
the BI field. For arbitrary time-varying BI fields, a study of cosmological
solutions reduces the scalar field stress-energy to that of a pressureless
perfect fluid in a comoving reference frame, forcing the scale factor dynamics
to be equivalent to those of a stiff equation of state. Upon ultraviolet
completion, this model could provide a natural mechanism for k-inflation, where
the role of the inflaton is played by the BI field and inflation is driven by
its non-trivial kinetic energy instead of a potential.


title:
Non-thermal emission in the core of Perseus: results from a long
  XMM-Newton observation

abstract:
  We employ a long XMM-Newton observation of the core of the Perseus cluster to
validate claims of a non-thermal component discovered with Chandra. From a
meticulous analysis of our dataset, which includes a detailed treatment of
systematic errors, we find the 2-10 keV surface brightness of the non-thermal
component to be smaller than about 5x10^-16 erg cm^-2s^-1arcsec^-2. The most
likely explanation for the discrepancy between the XMM-Newton and Chandra
estimates is a problem in the effective area calibration of the latter. Our
EPIC based magnetic field lower limits are not in disagreement with Faraday
rotation measure estimates on a few cool cores and with a minimum energy
estimate on Perseus. In the not too distant future Simbol-X may allow detection
of non-thermal components with intensities more than 10 times smaller than
those that can be measured with EPIC; nonetheless even the exquisite
sensitivity within reach for Simbol-X might be insufficient to detect the IC
emission from Perseus.


title: Immobilization of single strand DNA on solid substrate

abstract:
  Thin films based on Layer-by-Layer (LbL) self assembled technique are useful
for immobilization of DNA onto solid support. This communication reports the
immobilization of DNA onto a solid support by electrostatic interaction with a
polycation Poly (allylamine hydrochloride) (PAH). UV-Vis absorption and steady
state fluorescence spectroscopic studies exhibit the characteristics of DNA
organized in LbL films. The most significant observation is that single strand
DNA are immobilized on the PAH backbone of LbL films when the films are
fabricated above the melting temperature of DNA. DNA immobilized in this way on
LbL films remains as such when the temperature is restored at room temperature
and the organization remains unaffected even after several days. UV-Vis
absorption spectroscopic studies confirm this finding.


title:
A graphical extension for the Windows version of the Parallel Finite
  Element Micromagnetics Package (MagParExt)

abstract:
  In the current paper we present a graphical user interface useful for
settings input parameter of the Windows precompiled binaries for the Parallel
Finite Element Micromagnetics Package (MagPar). The Package is used for
magnetization dynamics analysis on a base of the Landau-Lifshitz-Gilbert (LLG)
equation. In an available version of the MagPar package there are several text
files which control simulations. Presented here graphical extension (MagParExt)
enables easy preparation of input and output data, stored in text files, and
additionally, direct and fast creation of figures obtained from dependencies
between simulated physical quantities.


title: Through a Glass Darkly

abstract:
  We consider the question of how mathematicians view themselves and how
non-mathematicians view us. What is our role in society? Is it effective? Is it
rewarding? How could it be improved? This paper will be part of a forthcoming
volume on this circle of questions.


title:
Signatures of Extra Dimensions from Upsilon Decays with a Light
  Gaugephobic Higgs Boson

abstract:
  We explore non-standard Higgs phenomenology in the Gaugephobic Higgs model in
which the Higgs can be lighter than the usually quoted current experimental
bound. The Higgs propagates in the bulk of a 5D space-time and Electroweak
Symmetry Breaking occurs by a combination of boundary conditions in the extra
dimension and an elementary Higgs. The Higgs can thus have a significantly
suppressed coupling to the other Standard Model fields. A large enough
suppression can be found to escape all limits and allow for a Higgs of any
mass, which would be associated with the discovery of W' and Z' Kaluza-Klein
resonances at the LHC. The Higgs can be precisely discovered at B-factories
while the LHC would be insensitive to it due to high backgrounds. In this
letter we study the Higgs discovery mode in Upsilon(3S), Upsilon(2S), and
Upsilon(1S) decays, and the model parameter space that will be probed by BaBar,
Belle, and CLEO data. In the absence of an early discovery of a heavy Higgs at
the LHC, A Super-B factory would be an excellent option to further probe this
region.


title: A categorification of the quantum sl(N)-link polynomials using foams

abstract:
  In this thesis we define and study a categorification of the sl(N)-link
polynomial using foams, for N\geq 3.
  For N=3 we define the universal sl(3)-link homology, using foams, which
depends on three parameters and show that it is functorial, up to scalars, with
respect to link cobordisms. Our theory is integral. We show that tensoring it
with Q yields a theory which is equivalent to the rational universal
Khovanov-Rozansky sl(3)-link homology.
  For N\geq 4 we construct a rational theory categorifying the sl(N)-link
polynomial using foams. Our theory is functorial, up to scalars, with respect
to link cobordisms. To evaluate closed foams we use the Kapustin-Li formula. We
show that for any link our homology is isomorphic to the Khovanov-Rozansky
homology. We conjecture that the theory is integral and we compute the
conjectured integral sl(N)-link homology for the (2,m)-torus links and show
that it has torsion of order N.


title:
Aggregation of P-terphenyl along with PMMA/SA at the Langmuir and
  Langmuir-Blodgett Films

abstract:
  Molecular aggregation and monolayer characteristics of non-amphiphilic
p-terphenyl (TP) mixed with either polymethyl methacrylate (PMMA) or stearic
acid (SA) at the air-water interface were investigated. The miscibility of the
two components was evaluated by measuring and analyzing surface pressure versus
area per molecule (pi-A) isotherm. Both attractive and repulsive interactions
between the sample (TP) and the matrix (PMMA or SA) were observed depending on
the composition and microenvironment. TP and PMMA/SA were not completely
miscible in the mixed monolayer. Aggregation and phase separation between
sample TP and matrix molecule was revealed by UV-Vis absorption spectroscopic
studies and confirmed by scanning electron micrograpgh of LB films.


title: Dynamics of Photo-excited Spins in InSb Based Quantum Wells

abstract:
  We report time resolved measurements of spin relaxation in doped and undoped
InSb quantum wells using degenerate and two-color magneto-optical Kerr effect
techniques. We observed that the photo-excited spin dynamics are strongly
influenced by laser excitation fluence and the doping profile of the samples.
In the low fluence regime, an oscillatory pattern was observed at low
temperatures ($\leq$ 77 K) in the samples with an asymmetric doping profile
which might be attributed to the quasi-collision-free spin relaxation regime.
Our measurements also suggest the influence of the barrier materials
(Al$_{x}$In$_{1-x}$Sb) on the spin relaxation in these material systems.


title:
Monolayer Characteristics of Pyrene Mixed with Stearic Acid at the
  Air-Water Interface

abstract:
  In the present communication we report the monolayer characteristics of
pyrene mixed with stearic acid (SA) at the air-water interface. The monolayer
properties are investigated by recording and analyzing the surface
pressure-area per molecule isotherm (pi-A) of the pyrene-SA mixed films. It is
observed that the pyrene and SA are miscible in the mixed monolayer. This
miscibility/nonideality leads to phase separation between the constituent
components (pyrene and SA). BAM image of the mixed monolayer confirms the
miscibility or nonideal mixing at the mixed monolayer.


title:
SMBH Spherically Symmetric Accretion Regulated by Violent Star Formation
  Feedback

abstract:
  The mounting evidence for violent nuclear star formation in Seyfert galaxies
has led us to consider the hydrodynamics of the matter reinserted by massive
stars through strong stellar winds and supernovae, under the presence of a
central massive BH. We show that in all cases there is a bimodal solution
strongly weighted by the location of the stagnation radius (Rst), which splits
the star cluster into two different zones. Matter reinserted within the
stagnation volume is to be accreted by the BH while its outer counterpart would
composed a star cluster wind. The mechanical power of the latter, ensures that
there is no accretion of the ISM into the BH and thus the BH accretion and its
luminosity is regulated by the star formation feedback. The location of the
stagnation radius is a function of three parameters: the BH mass, the
mechanical power (or mass) of the star formation event and the size of the star
forming region. Here we present our self-consistent, stationary solution,
discuss the accretion rates and BH luminosities and show that our model
predicts the intrinsic link between the BH activity and the starburst
parameters.


title: Finite baryon and isospin chemical potential in AdS/CFT with flavor

abstract:
  We investigate the thermodynamics of a thermal field theory in presence of
both a baryon and an isospin chemical potential. For this we consider a probe
of several D7-branes embedded in the AdS-Schwarzschild black hole background.
We determine the structure of the phase diagram and calculate the relevant
thermodynamical quantities both in the canonical and in the grand canonical
ensemble. We discuss how accidental symmetries present reflect themselves in
the phase diagram: In the case of two flavors, for small densities, there is a
rotational symmetry in the plane spanned by the baryon and isospin density
which breaks down at large densities, leaving a Z_4-symmetry. Finally, we
calculate vector mode spectral functions and determine their dependence on
either the baryon or the isospin density. For large densities, a new excitation
forms with energy below the known supersymmetric spectrum. Increasing the
density further, this excitation becomes unstable. We speculate that this
instability indicates a new phase of condensed mesons.


title:
Spectroscopic characterizations of the mixed Langmuir-Blodgett (LB)
  films of 2,2'-biquinoline molecules: evidence of dimer formation

abstract:
  This communication reports the -A isotherms and spectroscopic
characterizations of mixed Langmuir and Langmuir-Blodgett (LB) films of
nonamphiphilic 2, -biquinoline (BQ) molecules, mixed with polymethyl
methacrylate (PMMA) and stearic acid (SA). The pi-A isotherms and molefraction
versus area per molecule studies indicate complete immiscibility of sample (BQ)
and matrix (PMMA or SA) molecules. This immiscibility may lead to the formation
of microcrystalline aggregates of BQ molecules in the mixed LB films. The
scanning electron micrograph gives the visual evidence of microcrystalline
aggregates of BQ molecules in the mixed LB films. UV-Vis absorption,
fluorescence and excitation spectroscopic studies reveal the nature of these
microcrystalline aggregates. LB films lifted at higher surface pressure
indicate the formation of dimer or higher order n-mers.


title: Unifying Theories of Molecular, Community and Network Evolution

abstract:
  The origin of diversification and coexistence of genes and species have been
traditionally studied in isolated biological levels. Ecological and
evolutionary views have focused on the mechanisms that enable or constrain
species coexistence, genetic variation and the genetics of speciation, but a
unified theory linking those approaches is still missing. Here we introduce
evolutionary graphs in the context of neutral theories of molecular evolution
and biodiversity to provide a framework that simultaneously addresses
speciation rate and joint genetic and species diversities. To illuminate this
question we also study two models of evolution on graphs with fitness
differences, which provide insights on how genetic and ecological dynamics
drive the speed of diversification. Neutral evolution generates the highest
speed of speciation, species richness (i.e. five times and twice as many
species as compared to genetic and ecological graphs, respectively) and
genetic--species diversity (i.e., twice as many as genetic and ecological
graphs, respectively). Thus the speed of speciation, the genetic--species
diversity and coexistence can differ dramatically depending on whether genetic
factors versus ecological factors drive the evolution of the system. By linking
molecular, sexual and trophic behavior at ecological and evolutionary scales,
interacting graphs can illuminate the origin and evolution of diversity and
organismal coexistence.


title: Source and Channel Coding for Correlated Sources Over Multiuser Channels

abstract:
  Source and channel coding over multiuser channels in which receivers have
access to correlated source side information is considered. For several
multiuser channel models necessary and sufficient conditions for optimal
separation of the source and channel codes are obtained. In particular, the
multiple access channel, the compound multiple access channel, the interference
channel and the two-way channel with correlated sources and correlated receiver
side information are considered, and the optimality of separation is shown to
hold for certain source and side information structures. Interestingly, the
optimal separate source and channel codes identified for these models are not
necessarily the optimal codes for the underlying source coding or the channel
coding problems. In other words, while separation of the source and channel
codes is optimal, the nature of these optimal codes is impacted by the joint
design criterion.


title:
Multiscale modeling of plastic deformation of molybdenum and tungsten:
  I. Atomistic studies of the core structure and glide of 1/2<111> screw
  dislocations at 0 K

abstract:
  Owing to their non-planar cores 1/2<111> screw dislocations govern the
plastic deformation of BCC metals. Atomistic studies of the glide of these
dislocations at 0 K have been performed using Bond Order Potentials for
molybdenum and tungsten that account for the mixed metallic and covalent
bonding in transition metals. When applying pure shear stress in the slip
direction it displays significant twinning-antitwinning asymmetry for
molybdenum but not for tungsten. However, for tensile/compressive loading the
Schmid law breaks down in both metals, principally due to the effect of shear
stresses perpendicular to the slip direction that alter the dislocation core.
Recognition of this phenomenon forms a basis for the development of physically
based yield criteria that capture the breakdown of the Schmid law in BCC
metals. Moreover, dislocation glide may be preferred on {110} planes other than
the most highly stressed one, which is reminiscent of the anomalous slip
observed in many BCC metals.


title:
Mixing doubly stochastic quantum channels with the completely
  depolarizing channel

abstract:
  It is proved that every doubly stochastic quantum channel that is properly
averaged with the completely depolarizing channel can be written as a convex
combination of unitary channels. As a consequence, we find that the collection
of channels expressible as convex combinations of unitary channels has non-zero
Borel measure within the space of doubly stochastic channels.


title:
Elasticity and Viscosity of a Lyotropic Chromonic Nematic Studied with
  Dynamic Light Scattering

abstract:
  Using dynamic light scattering, we measure for the first time the
temperature-dependent elastic moduli and associated orientational viscosity
coefficients of the nematic phase in a self-assembled lyotropic chromonic
liquid crystal. The bend K3 and splay K1 moduli are an order of magnitude
higher than the twist K2 constant. The ratio K3/K1 shows an anomalous increase
with temperature; we attribute this to the shortening of the aggregates as
temperature increases. The viscosity coefficients also show a significant
anisotropy, as well as a strong temperature dependence; in particular, the bend
viscosity is three orders of magnitude smaller than the splay and twist
viscosities.


title: Visible spectroscopy in the neighborhood of 2003 EL61

abstract:
  Context: The recent discovery of a group of trans-neptunian objects (TNOs) in
a narrow region of the orbital parameter space and with surfaces composed of
almost pure water ice, being 2003 EL61 its largest member, promises new and
interesting results about the formation and evolution of the trans-neptunian
belt (TNb) and the outer Solar System.
  Aims: The aim of this paper is to obtain information of the surface
properties of two members of this group ((24835) 1995 SM55, (120178) 2003 OP32)
and three potential members (2003 UZ117, (120347) 2004 SB60 and 2005 UQ513) and
to use that in order to confirm or reject their association.
  Methods: We obtained visible spectra of five TNOs using the 3.58m Telescopio
Nazionale Galileo at the ''Roque de los Muchachos Observatory'' (La Palma,
Spain)
  Results: The spectra of the five TNOs are featureless within the
uncertainties and with colors from slightly blue to red (-2<
S'<18%/0.1microns). No signatures of any absorption are found.
  Conclusions: We confirm the association of 1995 SM55 and 2003 OP32 with the
group of 2003 EL61 as their spectra are almost identical to that of 2003 EL61.
Only one of the three candidates, 2003 UZ117, can be considered as a possible
member of the EL61-group, as its visible spectrum is compatible with a spectrum
of a surface composed of almost pure water ice and no complex organics. The
other two, 2004 SB60 and 2005 UQ513 are red and must be considered as
interlopers.


title:
Moving Vortex Phases, Dynamical Symmetry Breaking, and Jamming for
  Vortices in Honeycomb Pinning Arrays

abstract:
  We show using numerical simulations that vortices in honeycomb pinning arrays
can exhibit a remarkable variety of dynamical phases that are distinct from
those found for triangular and square pinning arrays. In the honeycomb arrays,
it is possible for the interstitial vortices to form dimer or higher n-mer
states which have an additional orientational degree of freedom that can lead
to the formation of vortex molecular crystals. For filling fractions where
dimer states appear, a novel dynamical symmetry breaking can occur when the
dimers flow in one of two possible alignment directions. This leads to
transport in the direction transverse to the applied drive. We show that
dimerization produces distinct types of moving phases which depend on the
direction of the driving force with respect to the pinning lattice symmetry.
When the dimers are driven along certain directions, a reorientation of the
dimers can produce a jamming phenomenon which results in a strong enhancement
in the critical depinning force. The jamming can also cause unusual effects
such as an increase in the critical depinning force when the size of the
pinning sites is reduced.


title: Cleaving-temperature dependence of layered-oxide surfaces

abstract:
  The surfaces generated by cleaving non-polar, two-dimensional oxides are
often considered to be perfect or ideal. However, single particle
spectroscopies on Sr2RuO4, an archetypal non-polar two dimensional oxide, show
significant cleavage temperature dependence. We demonstrate that this is not a
consequence of the intrinsic characteristics of the surface: lattice parameters
and symmetries, step heights, atom positions, or density of states. Instead, we
find a marked increase in the density of defects at the mesoscopic scale with
increased cleave temperature. The potential generality of these defects to
oxide surfaces may have broad consequences to interfacial control and the
interpretation of surface sensitive measurements.


title:
Applicability of the formulae of Bardin and Dokuchaeva for the radiative
  corrections analysis in the NuTeV experiment

abstract:
  We point out one of the possible sources of the "NuTeV anomaly": the effect
of the non-adequate application of the one-loop electroweak radiative
corrections including QED hard photon emission derived by Bardin and Dokuchaeva
(1986) in the NuTeV radiative corrections data analysis of deep inelastic
neutrino and anti-neutrino deep inelastic scattering.


title: Hadronic Decays of the X(3872) to chi_{cJ} in Effective Field Theory

abstract:
  The decays of the X(3872) to P-wave quarkonia are calculated under the
assumption that it is a shallow bound state of neutral charmed mesons. The
X(3872) is described using an effective theory of nonrelativistic D mesons and
pions (X-EFT). We calculate X(3872) decays by first matching heavy hadron
chiral perturbation theory (HHchiPT) amplitudes for D^0 bar{D}^{*0} -> chi_{cJ}
+ (pi^0,pi+pi) onto local operators in X-EFT, and then using these operators to
calculate the X(3872) decays. This procedure reproduces the factorization
theorems for X(3872) decays to conventional quarkonia previously derived using
the operator product expansion. For single pion decays, we find nontrivial
dependence on the pion energy from HHchiPT diagrams with virtual D mesons. This
nontrivial energy dependence can potentially modify heavy quark symmetry
predictions for the relative sizes of decay rates. At leading order, decays to
final states with two pions are dominated by the final state chi_{c1} + pi^0 +
pi^0, with a branching fraction just below that for the decay to chi_{c1} +
pi^0. Decays to all other final states with two pions are highly suppressed.


title:
Decay of a metastable state activated by non-Gaussian noise: A critical
  review of the generalized Kramers problem

abstract:
  We review the problem of the noise activated escape from a metastable state
in the presence of non-Gaussian noise, and present connections between various
theoretical approaches. We also respond to criticism of our work by Tom\'a\v{s}
Novotn\'y [arXiv:0807.0387] concerning the weak damping limit. The discrepancy
between our results is linked to uncontrolled approximations made by Novotn\'y.


title:
Global existence and uniqueness results for weak solutions of the
  focusing mass-critical non-linear Schr\"odinger equation

abstract:
  We consider the focusing mass-critical NLS $iu_t + \Delta u = - |u|^{4/d} u$
in high dimensions $d \geq 4$, with initial data $u(0) = u_0$ having finite
mass $M(u_0) = \int_{\R^d} |u_0(x)|^2 dx < \infty$. It is well known that this
problem admits unique (but not global) strong solutions in the Strichartz class
$C^0_{t,\loc} L^2_x \cap L^2_{t,\loc} L^{2d/(d-2)}_x$, and also admits global
(but not unique) weak solutions in $L^\infty_t L^2_x$. In this paper we
introduce an intermediate class of solution, which we call a
\emph{semi-Strichartz class solution}, for which one does have global existence
and uniqueness in dimensions $d \geq 4$. In dimensions $d \geq 5$ and assuming
spherical symmetry, we also show the equivalence of the Strichartz class and
the strong solution class (and also of the semi-Strichartz class and the
semi-strong solution class), thus establishing ``unconditional'' uniqueness
results in the strong and semi-strong classes. With these assumptions we also
characterise these solutions in terms of the continuity properties of the mass
function $t \mapsto M(u(t))$.


title: Algorithms for Dynamic Spectrum Access with Learning for Cognitive Radio

abstract:
  We study the problem of dynamic spectrum sensing and access in cognitive
radio systems as a partially observed Markov decision process (POMDP). A group
of cognitive users cooperatively tries to exploit vacancies in primary
(licensed) channels whose occupancies follow a Markovian evolution. We first
consider the scenario where the cognitive users have perfect knowledge of the
distribution of the signals they receive from the primary users. For this
problem, we obtain a greedy channel selection and access policy that maximizes
the instantaneous reward, while satisfying a constraint on the probability of
interfering with licensed transmissions. We also derive an analytical universal
upper bound on the performance of the optimal policy. Through simulation, we
show that our scheme achieves good performance relative to the upper bound and
improved performance relative to an existing scheme.
  We then consider the more practical scenario where the exact distribution of
the signal from the primary is unknown. We assume a parametric model for the
distribution and develop an algorithm that can learn the true distribution,
still guaranteeing the constraint on the interference probability. We show that
this algorithm outperforms the naive design that assumes a worst case value for
the parameter. We also provide a proof for the convergence of the learning
algorithm.


title:
Eigenfactor : Does the Principle of Repeated Improvement Result in
  Better Journal Impact Estimates than Raw Citation Counts?

abstract:
  Eigenfactor.org, a journal evaluation tool which uses an iterative algorithm
to weight citations (similar to the PageRank algorithm used for Google) has
been proposed as a more valid method for calculating the impact of journals.
The purpose of this brief communication is to investigate whether the principle
of repeated improvement provides different rankings of journals than does a
simple unweighted citation count (the method used by ISI).


title: A cabling formula for the colored Jones polynomial

abstract:
  We prove an explicit cabling formula for the colored Jones polynomial. As an
application we prove the volume conjecture for all zero volume knots and links,
i.e. all knots and links that are obtained from the unknot by repeated cabling
and connected sum.


title:
Group Divisible Codes and Their Application in the Construction of
  Optimal Constant-Composition Codes of Weight Three

abstract:
  The concept of group divisible codes, a generalization of group divisible
designs with constant block size, is introduced in this paper. This new class
of codes is shown to be useful in recursive constructions for constant-weight
and constant-composition codes. Large classes of group divisible codes are
constructed which enabled the determination of the sizes of optimal
constant-composition codes of weight three (and specified distance), leaving
only four cases undetermined. Previously, the sizes of constant-composition
codes of weight three were known only for those of sufficiently large length.


title:
Bounds on Bipartitiely Shared Entanglement Reduced from Superposed
  Tripartite Quantum States

abstract:
  For a tripartite pure state superposed by two individual states, the
bipartitely shared entanglement can always be achieved by local measurements of
the third party. Consider the different aims of the third party, i.e.
maximizing or minimizing the bipartitely shared entanglement, we find bounds on
both the possible bipartitely shared entanglement of the superposition state in
terms of the corresponding entanglement of the two states being superposed. In
particular, by choosing the concurrence as bipartite entanglement measure, we
obtain calculable bounds for tripartite $(2\otimes 2\otimes n)$ -dimensional
cases.


title: q-Euler Numbers and Polynomials Associated with Basic Zeta Functions

abstract:
  In this paper we give the q-extension of Euler numbers which can be viewed as
interpolating of the q-analogue of Euler zeta function ay negative integers, in
the same way that Riemann zeta function interpolates Bernoulli numbers at
negative integers. Finally we woll treat some identities of the q-extension of
the euler numbers by using fermionic p-adic q-integration on Z_p.


title:
Lattice Formulation of Two-Dimensional N=(2,2) SQCD with Exact
  Supersymmetry

abstract:
  We construct a lattice model for two-dimensional N=(2,2) supersymmetric QCD
(SQCD), with the matter multiplets belonging to the fundamental or
anti-fundamental representation of the gauge group U(N) or SU(N). The
construction is based on the topological field theory (twisted supercharge)
formulation and exactly preserves one supercharge along the line of the papers
[1]--[4] for pure supersymmetric Yang-Mills theories. In order to avoid the
species doublers of the matter multiplets, we introduce the Wilson terms and
the model is defined for the case of the number of the fundamental matters
(n_{+}) equal to that of the anti-fundamental matters (n_{-}). If some of the
matter multiplets decouple from the theory by sending the corresponding
anti-holomorphic twisted masses to the infinity, we can analyze the general
n_{+}\neq n_{-} case, although the lattice model is defined for n_{+} =n_{-}.
By computing the anomaly of the U(1)_A R-symmetry in the lattice perturbation,
we see that the decoupling is achieved and the anomaly for n_{+}\neq n_{-} is
correctly obtained.


title:
A new stochastic differential equation approach for waves in a random
  medium

abstract:
  We present a mathematical approach that simplifies the theoretical treatment
of electromagnetic localization in random media and leads to closed form
analytical solutions. Starting with the assumption that the dielectric
permittivity of the medium has delta-correlated spatial fluctuations, and using
the Ito lemma, we derive a linear stochastic differential equation for a one
dimensional random medium. The equation leads to localized wave solutions. The
localized wave solutions have a localization length that scales inversely with
the square of the frequency of the wave in the low frequency regime, whereas in
the high frequency regime, this length varies inversely with the frequency to
the power of two thirds.


title: Cardy-Verlinde Formula in Taub-NUT/Bolt-(A)dS space

abstract:
  We consider a finite action for a higher dimensional Taub-NUT/Bolt-(A)dS
space via the so-called counter term subtraction method. In the limit of high
temperature, we show that the Cardy-Verlinde formula holds for the
Taub-Bolt-AdS metric and for the specific dimensional Taub-NUT-(A)dS metric,
except for the Taub-Bolt-dS metric.


title: The Signature of the Chern Coefficients of Local Rings

abstract:
  This paper considers the following conjecture: If $R$ is an unmixed,
equidimensional local ring that is a homomorphic image of a Cohen-Macaulay
local ring, then for any ideal $J$ generated by a system of parameters, the
Chern coefficient $e_1(J)< 0$ is equivalent to $R$ being non Cohen-Macaulay.
The conjecture is established if $R$ is a homomorphic image of a Gorenstein
ring, and for all universally catenary integral domains containing fields.
Criteria for the detection of Cohen-Macaulayness in equi-generated graded
modules are derived.


title: Bayesian Limits on Primordial Isotropy Breaking

abstract:
  It is often assumed that primordial perturbations are statistically
isotropic, which implies, among other properties, that their power spectrum is
invariant under rotations. In this article, we test this assumption by placing
model-independent bounds on deviations from rotational invariance of the
primordial spectrum. Using five-year WMAP cosmic microwave anisotropy maps, we
set limits on the overall norm and the amplitude of individual components of
the primordial spectrum quadrupole. We find that there is no significant
evidence for primordial isotropy breaking, and that an eventually non-vanishing
quadrupole has to be subdominant.


title:
Coexistence of superconductivity and antiferromagnetism in self-doped
  bilayer t-t'-J model

abstract:
  A self-doped bilayer t-t'-J model of an electron- and a hole-doped planes is
studied by the slave-boson mean-field theory. A hopping integral between the
differently doped planes, which are generated by a site potential, are
renormalized by the electron-electron correlation. We find coexistent phases of
antiferromagnetic (AFM) and superconducting orders, although the magnitudes of
order parameters become more dissimilar in the bilayer away from half-filling.
Fermi surfaces (FS's) with the AFM order show two pockets around the nodal and
the anti-nodal regions. These results look like a composite of electron- and
hole-doped FS's. In the nodal direction, the FS splitting is absent even in the
bilayer system, since one band is flat due to the AFM order.


title: On kaleidoscopic pseudo-randomness of finite Euclidean graphs

abstract:
  In this paper we study the kaleidoscopic pseudo-randomness of finite
Euclidean graphs using probabilistic methods. Roughly speaking, we show that
sufficiently large subsets of d-dimensional vector spaces over finite fields
contain every possible finite configurations.


title: On the number of orthogonal systems in vector spaces over finite fields

abstract:
  Iosevich and Senger (2008) showed that if a subset of the d-dimensional
vector space over a finite field is large enough, then it contains many
k-tuples of mutually orthogonal vectors. In this note, we provide a graph
theoretic proof of this result.


title:
Statement of uncertainty principle for quantum measurements in terms of
  the Renyi entropies

abstract:
  The aim of the work is to give the explicit proofs of the Renyi-entropy
uncertainty relations presented in the previous work [A. Rastegin,
arXiv:0805.1777]. The relations with both the state-dependent and
state-independent entropic bounds are proved. For a pair of POVM measurements
the two relations are obtained. The first of them is generalization of the
known results, whereas the second is quite alternative. It is shown that both
these relations are meaty. The important case of POVM's with one-rank elements
is extra discussed. The measurements designed for distinction between two
non-orthogonal quantum states are considered as examples.


title: Explicit tough Ramsey graphs

abstract:
  A graph G is t-tough if any induced subgraph of it with x > 1 connected
components is obtained from G by deleting at least tx vertices. Chvatal
conjectured that there exists an absolute constant t_0 so that every t_0-tough
graph is pancyclic. This conjecture was disproved by Bauer, van den Heuvel and
Schmeichel by constructing a t_0-tough triangle-free graph for every real t_0.
For each finite field F_q with q odd, we consider graphs associated to the
finite Euclidean plane and the finite upper half plane over F_q. These graphs
have received serious attention as they have been shown to be Ramanujan (or
asymptotically Ramanujan) for large q. We will show that for infinitely many q,
these graphs provide further counterexamples to Chvatal's conjecture. They also
provide a good constructive lower bound for the Ramsey number R(3,k).


title:
On the volume functional of compact manifolds with boundary with
  constant scalar curvature

abstract:
  We study the volume functional on the space of constant scalar curvature
metrics with a prescribed boundary metric. We derive a sufficient and necessary
condition for a metric to be a critical point, and show that the only domains
in space forms, on which the standard metrics are critical points, are geodesic
balls. In the zero scalar curvature case, assuming the boundary can be
isometrically embedded in the Euclidean space as a compact strictly convex
hypersurface, we show that the volume of a critical point is always no less
than the Euclidean volume bounded by the isometric embedding of the boundary,
and the two volumes are equal if and only if the critical point is isometric to
a standard Euclidean ball. We also derive a second variation formula and apply
it to show that, on Euclidean balls and ''small'' hyperbolic and spherical
balls in dimensions 3 to 5, the standard space form metrics are indeed saddle
points for the volume functional.


title:
Algorithms for Scheduling Weighted Packets with Deadlines in a Bounded
  Queue

abstract:
  Motivated by the Quality-of-Service (QoS) buffer management problem, we
consider online scheduling of packets with hard deadlines in a finite capacity
queue. At any time, a queue can store at most $b \in \mathbb Z^+$ packets.
Packets arrive over time. Each packet is associated with a non-negative value
and an integer deadline. In each time step, only one packet is allowed to be
sent. Our objective is to maximize the total value gained by the packets sent
by their deadlines in an online manner. Due to the Internet traffic's chaotic
characteristics, no stochastic assumptions are made on the packet input
sequences. This model is called a {\em finite-queue model}.
  We use competitive analysis to measure an online algorithm's performance
versus an unrealizable optimal offline algorithm who constructs the worst
possible input based on the knowledge of the online algorithm. For the
finite-queue model, we first present a deterministic 3-competitive memoryless
online algorithm. Then, we give a randomized ($\phi^2 = ((1 + \sqrt{5}) / 2)^2
\approx 2.618$)-competitive memoryless online algorithm.
  The algorithmic framework and its theoretical analysis include several
interesting features. First, our algorithms use (possibly) modified
characteristics of packets; these characteristics may not be same as those
specified in the input sequence. Second, our analysis method is different from
the classical potential function approach.


title: Search for Lepton Flavor Violation in Upsilon Decays

abstract:
  In this Letter we describe a search for lepton flavor violation (LFV) in the
bottomonium system. We search for leptonic decays of Upsilon(nS)(n=1,2, and 3)
into muon and tau using the data collected with the CLEO III detector. We
identify the tau lepton using its leptonic decay into electron and utilize
multidimensional likelihood fitting with PDF shapes measured from independent
data samples. We report our estimates of 95% CL upper limits on LFV branching
fractions of Upsilon mesons. We interpret our results in terms of the exclusion
plot for the energy scale of a hypothetical new interaction versus its
effective LFV coupling in the framework of effective field theory.


title: Effective Action of QED in Electric Field Backgrounds

abstract:
  We use the evolution operator method to find the one-loop effective action of
scalar and spinor QED in electric field backgrounds in terms of the Bogoliubov
coefficient between the ingoing and the outgoing vacua. We obtain the exact
one-loop effective action for a Sauter-type electric field, E_0 sech^2 (t/tau),
and show that the imaginary part correctly yields the vacuum persistence. The
renormalized effective action shows the general relation between the vacuum
persistence and the total mean number of created pairs for the constant and the
Sauter-type electric field.


title:
The solar wind disappearance event of 11 May 1999: source region
  evolution

abstract:
  Context. A recent, detailed study of the well-known solar wind disappearance
event of 11 May 1999 traced its origin to a coronal hole (CH) lying adjacent to
a large active region (AR), AR8525 in Carrington rotation 1949. The AR was
located at central meridian on 05 May 1999 when the flows responsible for this
event began. We examine the evolution of the AR-CH complex during 5-6 May 1999
to study the changes that apparently played a key role in causing this
disappearance event. Aims. To study the evolution of the solar source region of
the disappearance event of 11 May 1999. Methods. Using images from the Soft
X-ray Telescope (SXT), the Extreme-ultraviolet Imaging Telescope (EIT) and the
Michelson Doppler Imager (MDI) to examine the evolution of the CH and AR
complex at the source region of the disappearance event. Results. We find a
dynamic evolution taking place in the CH-AR boundary at the source region of
the disappearance event of 11 May 1999. This evolution, which is found to
reduce the area of the CH, is accompanied by the formation of new loops in EUV
images that are spatially and temporally correlated with emerging flux regions
as seen in MDI data. Conclusions. In the period leading up to the disappearance
event of 11 May 1999, our observations, during quiet solar conditions and in
the absence of CMEs, provide the first clear evidence for Sun-Earth connection
originating from an evolving AR-CH region located at central meridian. With the
exception of corotating interacting regions (CIR), these observations provide
the first link between the Sun and space weather effects at 1 AU, arising from
non-explosive solar events.


title:
Mesoscopic model for mechanical characterization of biological protein
  materials

abstract:
  Mechanical characterization of protein molecules has played a role on gaining
insight into the biological functions of proteins, since some proteins perform
the mechanical function. Here, we present the mesoscopic model of biological
protein materials composed of protein crystals prescribed by Go potential for
characterization of elastic behavior of protein materials. Specifically, we
consider the representative volume element (RVE) containing the protein
crystals represented by alpha-carbon atoms, prescribed by Go potential, with
application of constant normal strain to RVE. The stress-strain relationship
computed from virial stress theory provides the nonlinear elastic behavior of
protein materials and their mechanical properties such as Young's modulus,
quantitatively and/or qualitatively comparable to mechanical properties of
biological protein materials obtained from experiments and/or atomistic
simulations. Further, we discuss the role of native topology on the mechanical
properties of protein crystals. It is shown that parallel strands (hydrogen
bonds in parallel) enhances the mechanical resilience of protein materials.


title:
Variation of Bar Strength with Central Velocity Dispersion in Spiral
  Galaxies

abstract:
  We investigate the variation of bar strength with central velocity dispersion
in a sample of barred spiral galaxies. The bar strength is characterized by
$Q_g$, the maximal tangential perturbation associated with the bar, normalized
by the mean axisymmetric force. It is derived from the galaxy potentials which
are obtained using near-infrared images of the galaxies. However, $Q_g$ is
sensitive to bulge mass. Hence we also estimated bar strengths from the
relative Fourier intensity amplitude ($A_{2}$) of bars in near-infrared images.
The central velocity dispersions were obtained from integral field spectroscopy
observations of the velocity fields in the centers of these galaxies; it was
normalized by the rotation curve amplitude obtained from HI line width for each
galaxy. We found a correlation between bar strengths (both $Q_g$ and $A_{2}$)
and the normalized central velocity dispersions in our sample. This suggests
that bars weaken as their central components become kinematically hotter. This
may have important implications for the secular evolution of barred galaxies.


title: Coulomb-nuclear interference in pion-nucleus bremsstrahlung

abstract:
  Pion-nucleus bremsstrahlung offers a possibility of measuring the structure
functions of pion-Compton scattering from a study of the
small-momentum-transfer region where the bremsstrahlung reaction is dominated
by the single-photon-exchange mechanism. The corresponding cross-section
distribution is characterized by a sharp peak at small momentum transfers. But
there is also a hadronic contribution which is smooth and constitutes an
undesired background. In this communication the modification of the
single-photon exchange amplitude by multiple-Coulomb scattering is investigated
as well as the Coulomb-nuclear interference term.


title:
A Cutting Plane Method based on Redundant Rows for Improving Fractional
  Distance

abstract:
  In this paper, an idea of the cutting plane method is employed to improve the
fractional distance of a given binary parity check matrix. The fractional
distance is the minimum weight (with respect to l1-distance) of vertices of the
fundamental polytope. The cutting polytope is defined based on redundant rows
of the parity check matrix and it plays a key role to eliminate unnecessary
fractional vertices in the fundamental polytope. We propose a greedy algorithm
and its efficient implementation for improving the fractional distance based on
the cutting plane method.


title:
Unitary isomorphism of Fock spaces of bosons and fermions arising from a
  representation of the Cuntz algebra $\co{2}$

abstract:
  Bosons and fermions are described by using canonical generators of Cuntz
algebras on any permutative representation. According to branching laws
associated with these descriptions, a certain representation of the Cuntz
algebra $\co{2}$ induces Fock representations ${\cal H}_{B}$ and ${\cal H}_{F}$
of bosons and fermions simultaneously. From this, a unitary operator $U$ from
${\cal H}_{B}$ to ${\cal H}_{F}$ is obtained. We show the explicit formula of
the action of $U$ on the standard basis of ${\cal H}_{B}$. It is shown that $U$
preserves the particle number of ${\cal H}_{B}$ and ${\cal H}_{F}$.


title: Coupled dynamics of an atom and an optomechanical cavity

abstract:
  We consider the motion of the end mirror of a cavity inside which a two-level
atom trapped. The fast vibrating mirror induces nonlinear couplings between the
cavity field and the atom. We analyze this optical effect by showing the
population of the atom in its internal degrees of freedom as a function of
time. On the other side, fast atom-field variables result in an additional
potential for the atomic center-of-mass motion and the mirror vibration,
leading to entanglement in the motion and the vibration. The entanglement has
been numerically simulated and discussed.


title: An Explicit Microreversibility Violating Thermodynamic Markov Process

abstract:
  We explicitly construct a non-microreversible transition matrix for a Markov
process and apply it to the standard three-state Potts model. This provides a
clear and simple demonstration that the usual micoreversibility property of
thermodynamical Monte Carlo algorithms is not strictly necessary from a
mathemetical point of view.


title:
Optimal lower bounds on the maximal p-negative type of finite metric
  spaces

abstract:
  This article derives lower bounds on the supremal (strict) p-negative type of
finite metric spaces using purely elementary techniques. The bounds depend only
on the cardinality and the (scaled) diameter of the underlying finite metric
space. Examples show that these lower bounds can easily be best possible under
clearly delineated circumstances. We further point out that the entire theory
holds (more generally) for finite semi-metric spaces without modification and
wherein the lower bounds are always optimal.


title: Anisotropic superconductivity in graphite intercalation compound YbC6

abstract:
  We report anisotropy of the upper critical field (Bc2) of an intercalated
graphite superconductor YbC6 (Tc = 6.5 K) determined from angular dependent
magnetoresistance measurements. Though the perpendicular coherence length is
much longer than interlayer spacing, measured angular dependences of Bc2 are
well fitted by the Lawrence-Doniach model or the Tinkham model, which are known
to be applicable to quasi two-dimensional materials or thin films, rather than
the effective mass model. This observation is similar to the measurements for
the other intercalated graphite superconductor, CaC6, by Jobiliong et al. [E.
Jobiliong, H.D. Zhou, J.A. Janik, Y.-J. Jo, L. Balicas, J.S. Brooks, C.R.
Wiebe, Phys. Rev. B 76 (2007) 31 052511]. A possible explanation for the
unexpected applicability of these models is that our YbC6 samples are
synthesized as thin flakes in the host graphite.


title: Latin trades in groups defined on planar triangulations

abstract:
  For a finite triangulation of the plane with faces properly coloured white
and black, let A be the abelian group constructed by labelling the vertices
with commuting indeterminates and adding relations which say that the labels
around each white triangle add to the identity. We show that A has free rank
exactly two. Let A* be the torsion subgroup of A, and B* the corresponding
group for the black triangles. We show that A* and B* have the same order, and
conjecture that they are isomorphic.
  For each spherical latin trade W, we show there is a unique disjoint mate B
such that (W,B) is a connected and separated bitrade. The bitrade (W,B) is
associated with a two-colourable planar triangulation and we show that W can be
embedded in A*, thereby proving a conjecture due to Cavenagh and Drapal. The
proof involves constructing a (0,1) presentation matrix whose permanent and
determinant agree up to sign. The Smith Normal Form of this matrix determines
A*, so there is an efficient algorithm to construct the embedding. Contrasting
with the spherical case, for each genus g>0 we construct a latin trade which is
not embeddable in any group and another that is embeddable in a cyclic group.
  We construct a sequence of spherical latin trades which cannot be embedded in
any family of abelian groups whose torsion ranks are bounded. Also, we show
that any trade that can be embedded in a finitely generated abelian group can
be embedded in a finite abelian group. As a corollary, no trade can be embedded
in a free abelian group.


title:
Copernicus's epicycles from Newton's gravitational force law via linear
  perturbation theory in geometric algebra

abstract:
  We derive Copernicus's epicycles from Newton's gravitational force law by
assuming that a planet's orbit is a perturbed circular orbit, with the
perturbation defined to be co-rotating with the said orbit. We substitute this
orbit expression into Newton's gravitation law and showed that the perturbation
satisfies the linear part of Hill's oscillator equation for lunar motion. We
solve this oscillator equation using an exponential Fourier series and impose
the boundary conditions at the aphelion and perihelion to derive Copernicus's
formulas for the eccentric, deferent, and epicycle. We show that for small
eccetricity, the Copernican orbit expression also leads to Kepler's law of
areas for planetary motion. The formalism we use is the Clifford (geometric)
algebra Cl_{2,0}.


title:
Large Magnetoresistance of a Dilute $p$-Si/SiGe/Si Quantum Well in a
  Parallel Magnetic Field

abstract:
  We report the results of an experimental study of the magnetoresistance
$\rho_{xx}$ in two samples of $p$-Si/SiGe/Si with low carrier concentrations
$p$=8.2$\times10^{10}$ cm$^{-2}$ and $p$=2$\times10^{11}$ cm$^{-2}$. The
research was performed in the temperature range of 0.3-2 K in the magnetic
fields of up to 18 T, parallel to the two-dimensional (2D) channel plane at two
orientations of the in-plane magnetic field $B_{\parallel}$ against the current
$I$: $B_{\parallel} \perp I$ and $B_{\parallel} \parallel I$. In the sample
with the lowest density in the magnetic field range of 0-7.2 T the temperature
dependence of $\rho_{xx}$ demonstrates the metallic characteristics ($d
\rho_{xx}/dT>$0). However, at $B_{\parallel}$ =7.2 T the derivative $d
\rho_{xx}/dT$ reverses the sign. Moreover, the resistance depends on the
current orientation with respect to the in-plane magnetic field. At
$B_{\parallel} \cong$ 13 T there is a transition from the dependence
$\ln(\Delta\rho_{xx} / \rho_{0})\propto B_{\parallel}^2$ to the dependence
$\ln(\Delta\rho_{xx} / \rho_{0})\propto B_{\parallel}$. The observed effects
can be explained by the influence of the in-plane magnetic field on the orbital
motion of the charge carriers in the quasi-2D system.


title: Observation of excited states in a graphene quantum dot

abstract:
  We demonstrate that excited states in single-layer graphene quantum dots can
be detected via direct transport experiments. Coulomb diamond measurements show
distinct features of sequential tunneling through an excited state. Moreover,
the onset of inelastic cotunneling in the diamond region could be detected. For
low magnetic fields, the positions of the single-particle energy levels
fluctuate on the scale of a flux quantum penetrating the dot area. For higher
magnetic fields, the transition to the formation of Landau levels is observed.
Estimates based on the linear energy-momentum relation of graphene give carrier
numbers of the order of 10 for our device.


title: Entanglement swapping between spacelike separated atoms

abstract:
  We show a mechanism that projects a pair of neutral two-level atoms from an
initially uncorrelated state to a maximally entangled state while they remain
spacelike separated. The atoms begin both excited in a common electromagnetic
vacuum, and the radiation is collected with a partial Bell-state analyzer. If
the interaction time is short enough and a certain two-photon Bell state is
detected after the interaction, a high degree of entanglement, even maximal,
can be generated while one atom is outside the light cone of the other, for
arbitrary large interatomic distances.


title: Time-dependent natural orbitals and occupation numbers

abstract:
  We report equations of motion for the occupation numbers of natural spin
orbitals and show that adiabatic extensions of common functionals employed in
ground-state reduced-density-matrix-functional theory have the shortcoming of
leading always to occupation numbers which are independent of time. We
illustrate the exact time-dependence of the natural spin orbitals and
occupation numbers for the case of electron-ion scattering and for atoms in
strong laser fields. In the latter case, we observe strong variations of the
occupation numbers in time.


title: Super Spin-Charge Separation for class A, C, and D disorder

abstract:
  We prove versions of super spin-charge separation for all three of the
symmetry groups SU(N), Sp(2N), and SO(N) of disordered Dirac fermions in 2+1
dimensions, which involve the supercurrent-algebras gl (1|1)_{N},
osp(2|2)_{-2N}, and osp(2|2)_N respectively. For certain restricted classes of
disordered potentials, the latter supercurrent algebra based conformal field
theories can arise as non-trivial low energy fixed points. For all cases with
such a fixed point, we compute the density of states exponents as a function of
N.

categories: math-ph cond-mat.dis-nn hep-ph hep-th math.MP


title:
The polynomial representation of the double affine Hecke algebra of type
  $(C^\vee_n, C_n)$ for specialized parameters

abstract:
  In this paper, we study the polynomial representation of the double affine
Hecke algebra of type $(C^\vee_n, C_n)$ for specialized parameters. Inductively
and combinatorially, we give a linear basis of the representation in terms of
linear combinations of non-symmetric Koornwinder polynomials. The basis
consists of generalized eigenfunctions with respect to $q$-Dunkl-Cherednik
operators $\hat{Y}_i$, and it gives a way to cancel out poles of non-symmetric
Koornwinder polynomials. We examine irreducibility and $Y$-semisimplicity of
the representation for the specialized parameters. For some cases, we give a
characterization of the subrepresentations by vanishing conditions for Laurent
polynomials.


title: Some properties of deformed Sine Gordon models

abstract:
  We study some properties of the deformed Sine Gordon models. These models,
presented by Bazeia et al, are natural generalisations of the Sine Gordon
models in (1+1) dimensions. There are two classes of them, each dependent on a
parameter n. For special values of this parameter the models reduce to the Sine
Gordon one; for other values of n they can be considered as generalisations of
this model. The models are topological and possess one kink solutions. Here we
investigate the existence of other solutions of these models - such as
breathers. The work is numerical and we find that the breathers, as such,
probably do not exist. However, we show that some of these models, namely, the
n = 1 of the first class possess breather-like solutions which are
quasi-stable; ie these quasi-breathers exist for long periods of time
(thousands of periods of oscillations). These results are found to be
independent of the discretisation used in the numerical part of our work.


title:
Efficient Turbulent Compressible Convection in the Deep Stellar
  Atmosphere

abstract:
  This paper reports an application of gas-kinetic BGK scheme to the
computation of turbulent compressible convection in the stellar interior. After
incorporating the Sub-grid Scale (SGS) turbulence model into the BGK scheme, we
tested the effects of numerical parameters on the quantitative relationships
among the thermodynamic variables, their fluctuations and correlations in a
very deep, initially gravity-stratified stellar atmosphere. Comparison
indicates that the thermal properties and dynamic properties are dominated by
different aspects of numerical models separately. An adjustable Deardorff
constant in the SGS model $c_\mu=0.25$ and an amplitude of artificial viscosity
in the gas-kinetic BGK scheme $C_2=0$ are appropriate for current study. We
also calculated the density-weighted auto- and cross-correlation functions in
Xiong's (\cite{xiong77}) turbulent stellar convection theories based on which
the gradient type of models of the non-local transport and the anisotropy of
the turbulence are preliminarily studied. No universal relations or constant
parameters were found for these models.


title: Delayed currents and interaction effects in mesoscopic capacitors

abstract:
  We propose an alternative derivation for the dynamic admittance of a gated
quantum dot connected by a single-channel lead to an electron reservoir. Our
derivation, which reproduces the result of Pr\^{e}tre, Thomas, and B\"{u}ttiker
for the universal charge-relaxation resistance, shows that at low frequencies,
the current leaving the dot lags after the entering one by the Wigner-Smith
delay time. We compute the capacitance when interactions are taken into account
only on the dot within the Hartree-Fock approximation and study the
Coulomb-blockade oscillations as a function of the Fermi energy in the
reservoir. In particular we find that those oscillations disappear when the dot
is fully `open', thus we reconcile apparently conflicting previous results.


title: Photosensitive Strip RETHGEM

abstract:
  An innovative photosensitive gaseous detector, consisting of a GEM like
amplification structure with double layered electrodes (instead of commonly
used metallic ones) coated with a CsI reflective photocathode, is described. In
one of our latest designs, the inner electrode consists of a metallic grid and
the outer one is made of resistive strips; the latter are manufactured by a
screen printing technology on the top of the metallic strips grid The inner
metallic grid is used for 2D position measurements whereas the resistive layer
provides an efficient spark protected operation at high gains - close to the
breakdown limit. Detectors with active areas of 10cm x10cm and 10cm x20cm were
tested under various conditions including the operation in photosensitive gas
mixtures containing ethylferrocene or TMAE vapors. The new technique could have
many applications requiring robust and reliable large area detectors for UV
visualization, as for example, in Cherenkov imaging devices.


title: Attractive and repulsive cracks in a heterogeneous material

abstract:
  We study experimentally the paths of an assembly of cracks growing in
interaction in a heterogeneous two-dimensional elastic brittle material
submitted to uniaxial stress. For a given initial crack assembly geometry, we
observe two types of crack path. The first one corresponds to a repulsion
followed by an attraction on one end of the crack and a tip to tip attraction
on the other end. The second one corresponds to a pure attraction. Only one of
the crack path type is observed in a given sample. Thus, selection between the
two types appears as a statistical collective process.


title:
The Berry phase: a topological test for the spectrum structure of
  frustrated quantum spin systems

abstract:
  The nature of the low energy spectrum of frustrated quantum spin systems is
investigated by means of a topological test introduced by Y. Hatsugai which
enables to infer the possible existence or absence of a gap between the ground
state and excited states of these systems. The test relies on the determination
of an order parameter which is a Berry phase. The structure of the spectra of
even and odd-legged systems in 2d and 3d is analyzed. Results are confronted
with previous work.


title: Heavy quarkonium hybrids from Coulomb gauge QCD

abstract:
  Using the non-relativisitc reduction of Coulomb gauge QCD we compute spectrum
of the low mass hybrid mesons containing a heavy quark-antiquark pair. The
gluon degrees of freedom are treated in the mean field approximation calibrated
to the gluelump spectrum. We discuss the role of the non-abelian nature of the
QCD Coulomb interaction in the ordering of the spin-parity levels.


title:
Model-independent description of $B\to \pi l\nu$ decays and a
  determination of $|V_{ub}|$

abstract:
  We propose a new parametrization of the $B\to\pi$ vector form factor,
$f_+(q^2)$, as an expansion in powers of a conformal mapping variable, which
satisfies unitarity, analyticity and perturbative QCD scaling. The unitarity
constraint is used also for defining the systematic error of the expansion. We
fit with the new parametrization the available experimental and theoretical
information on exclusive $B\to\pi l\nu$ decays, making a conservative estimate
of the effects of correlations in the systematic and statistical errors of the
lattice results. With four parameters to describe $f_+(q^2)$, the systematic
error is negligible in the whole semileptonic region. We also obtain
$|V_{ub}|=(3.54 \pm 0.30) \times 10^{-3}$ where, in our approach, the
uncertainty is predominantly statistical.


title:
Neutrino-Nucleus Reaction Cross Sections for Light Element Synthesis in
  Supernova Explosions

abstract:
  The neutrino-nucleus reaction cross sections of 4He and 12C are evaluated
using new shell model Hamiltonians. Branching ratios of various decay channels
are calculated to evaluate the yields of Li, Be, and B produced through the
nu-process in supernova explosions. The new cross sections enhance the yields
of 7Li and 11B produced during the supernova explosion of a 16.2 M_odot star
model compared to the case using the conventional cross sections by about 10%.
On the other hand, the yield of 10B decreases by a factor of two. The yields of
6Li, 9Be, and the radioactive nucleus 10Be are found at a level of 10^{-11}
M_odot. The temperature of nu_{mu,tau}- and bar{nu}_{mu,tau}-neutrinos inferred
from the supernova contribution of 11B in Galactic chemical evolution models is
constrained to the 4.3-6.5 MeV range. The increase in the 7Li and 11B yields
due to neutrino oscillations is demonstrated with the new cross sections.


title: An Asymptotic Analysis of the MIMO BC under Linear Filtering

abstract:
  We investigate the MIMO broadcast channel in the high SNR regime when linear
filtering is applied instead of dirty paper coding. Using a user-wise rate
duality where the streams of every single user are not treated as
self-interference as in the hitherto existing stream-wise rate dualities for
linear filtering, we solve the weighted sum rate maximization problem of the
broadcast channel in the dual multiple access channel. Thus, we can exactly
quantify the asymptotic rate loss of linear filtering compared to dirty paper
coding for any channel realization. Having converted the optimum covariance
matrices to the broadcast channel by means of the duality, we observe that the
optimal covariance matrices in the broadcast channel feature quite complicated
but still closed form expressions although the respective transmit covariance
matrices in the dual multiple access channel share a very simple structure. We
immediately come to the conclusion that block-diagonalization is the
asymptotically optimum transmit strategy in the broadcast channel. Out of the
set of block-diagonalizing precoders, we present the one which achieves the
largest sum rate and thus corresponds to the optimum solution found in the dual
multiple access channel. Additionally, we quantify the ergodic rate loss of
linear coding compared to dirty paper coding for Gaussian channels with
correlations at the mobiles.


title: Ratchet effect in inhomogeneous inertial systems: I. Adiabatic case

abstract:
  Risken's matrix continued fraction method is used to solve the Fokker-Planck
equation to calculate particle current in an inertial symmetric (sinusoidal)
periodic potential under the action of a constant force. The particle moves in
a medium with friction coefficient also varying periodically in space as the
potential but with a finite phase difference $\phi (\ne n\pi, n=0,1,2, ...)$.
The algebraic sum of current with applied forces $\pm|F|$ gives the ratchet
current in the adiabatic limit. Even though, the effect of frictional
inhomogeneity is weak, the ratchet current shows very rich qualitative
characteristics. The effects of variation of $F$, the temperature $T$, and the
average friction coefficient $\gamma_0$ on the performance characteristics of
the ratchet are presented.


title:
Penalized estimate of the number of states in Gaussian linear AR with
  Markov regime

abstract:
  We deal with the estimation of the regime number in a linear Gaussian
autoregressive process with a Markov regime (AR-MR). The problem of estimating
the number of regimes in this type of series is that of determining the number
of states in the hidden Markov chain controlling the process. We propose a
method based on penalized maximum likelihood estimation and establish its
strong consistency (almost sure) without assuming previous bounds on the number
of states.


title:
Identification of an average temperature and a dynamical pressure in a
  multitemperature mixture of fluids

abstract:
  We present a classical approach of a mixture of compressible fluids when each
constituent has its own temperature. The introduction of an average temperature
together with the entropy principle dictates the classical Fick law for
diffusion and also novel constitutive equations associated with the difference
of temperatures between the components. The constitutive equations fit with
results recently obtained through Maxwellian iteration procedure in extended
thermodynamics theory of multitemperature mixtures. The differences of
temperatures between the constituents imply the existence of a new dynamical
pressure even if the fluids have a zero bulk viscosity. The nonequilibrium
dynamical pressure can be measured and may be convenient in several physical
situations as for example in cosmological circumstances where - as many authors
assert - a dynamical pressure played a major role in the evolution of the early
universe.


title: Iterative ('Turbo') Multiuser Detectors For Impulse Radio Systems

abstract:
  In recent years, there has been a growing interest in multiple access
communication systems that spread their transmitted energy over very large
bandwidths. These systems, which are referred to as ultra wide-band (UWB)
systems, have various advantages over narrow-band and conventional wide-band
systems. The importance of multiuser detection for achieving high data or low
bit error rates in these systems has already been established in several
studies. This paper presents iterative ('turbo') multiuser detection for
impulse radio (IR) UWB systems over multipath channels. While this approach is
demonstrated for UWB signals, it can also be used in other systems that use
similar types of signaling. When applied to the type of signals used by UWB
systems, the complexity of the proposed detector can be quite low. Also, two
very low complexity implementations of the iterative multiuser detection scheme
are proposed based on Gaussian approximation and soft interference
cancellation. The performance of these detectors is assessed using simulations
that demonstrate their favorable properties.


title: Detection of vibrationally excited methyl formate in W51 e2

abstract:
  Methyl formate in its first torsionally excited state (vt=1 at 131 cm-1) is
detected for the first time toward W51 e2. All transitions from excited methyl
formate within the observed spectral range are actually detected (82
transitions) and no strong lines are missing. The column density of the excited
state is comparable to that of the ground state. For a source size of 7'' we
find that Trot = 104 +/- 14 K and N = 9.4 +4.0/-2.8 x 10^16 cm-2 for the
excited state and Trot = 176 +/- 24 K and N = 1.7 +.2/-.2 x 10^17 cm-2 for the
ground state. Lines from ethyl cyanide in its two first excited states (vt=1,
torsion mode at 212 cm-1) and (vb=1, CCN in-plane bending mode at 206 cm-1) are
also present in the observed spectrum. However blending problems prevent a
precise estimate of its abundance. With regard to the number of lines of
excited methyl formate and ethyl cyanide detected in W51 e2, it appears that
excited states of large molecules certainly account for a large number of
unidentified lines in spectral survey of molecular clouds.


title: Position Estimation via Ultra-Wideband Signals

abstract:
  The high time resolution of ultra-wideband (UWB) signals facilitates very
precise position estimation in many scenarios, which makes a variety
applications possible. This paper reviews the problem of position estimation in
UWB systems, beginning with an overview of the basic structure of UWB signals
and their positioning applications. This overview is followed by a discussion
of various position estimation techniques, with an emphasis on time-based
approaches, which are particularly suitable for UWB positioning systems.
Practical issues arising in UWB signal design and hardware implementation are
also discussed.


title:
Resource Letter: Bio-molecular Nano-machines: where Physics, Chemistry,
  Biology and Technology meet

abstract:
  Cell is the structural and functional unit of life. This Resource Letter
serves as a guide to the literature on nano-machines which drive not only
intracellular movements, but also motility of the cell. These machines are
usually proteins or macromolecular assemblies which require appropriate fuel
for their operations. Although, traditionally, these machines were subjects of
investigation in biology and biochemistry, increasing use of the concepts and
techniques of physics in recent years have contributed to the quantitative
understanding of the fundamental principles underlying their operational
mechanisms. The possibility of exploiting these principles for the design and
control of artificial nano-machines has opened up a new frontier in the
bottom-up approach to nano-technology.


title: Constraints on the spectra of 17,19C

abstract:
  Diverse means are used to investigate the spectra of the radioactive, exotic
ions, 17,19C. First, estimates have been made using a shell model for the
systems. Information from those shell model studies were then used in
evaluating cross sections of the scattering of 70A MeV 17,19C ions from
hydrogen. Complementing those studies, a multichannel algebraic scattering
(MCAS) theory for n+16,18C coupled-channel problems has been used to identify
structures of the compound systems. The results show that the shell model
structure assumed for these ions is reasonable with little need of effective
charges. The conditions that two excited states exist within a few hundred keV
of the ground state places some restriction upon the structure models. Other
positive parity states are expected in the low-lying spectra of the two nuclei.


title: SSC scenario for VHE emission from 2 radiogalaxies: M 87 and Cen A

abstract:
  M 87 is the first extragalactic source detected in the Very High Energy (VHE;
E > 100 GeV) gamma-ray domain that is not a blazar, its large scale jet not
being aligned to the line of sight. Slight modification of standard emission
models of TeV blazars allows to account for the gamma-ray spectra obtained with
H.E.S.S. We present a multi-blob synchrotron self-Compton model taking
explicitly into account large viewing angles and moderate values of the Lorentz
factor as inferred from MHD simulations of jet formation. Predictions of the
VHE emission for the nearby radiogalaxy Cen A and an interpretation of the
broadband radiation of M 87 are presented.


title: Lower bounds for posterior rates with Gaussian process priors

abstract:
  Upper bounds for rates of convergence of posterior distributions associated
to Gaussian process priors are obtained by van der Vaart and van Zanten in [14]
and expressed in terms of a concentration function involving the Reproducing
Kernel Hilbert Space of the Gaussian prior. Here lower-bound counterparts are
obtained. As a corollary, we obtain the precise rate of convergence of
posteriors for Gaussian priors in various settings. Additionally, we extend the
upper-bound results of [14] about Riemann-Liouville priors to a continuous
family of parameters.


title: Precision Standard Model Tests with Kaons

abstract:
  In kaon physics, several new precision measurements on flavour variables and
CP violation have performed in the recent years. Presented are a new precise
determination of the CKM parameter |V_us|, which combines the results of all
experiments together with recent theoretical progress, and new measurements of
the ratio R_K = Gamma(K+ -> e+ nu)/Gamma(K+ -> mu+ nu), which is sensitive to
contributions of a possible charged Higgs in the SUSY framework. Also, final
results of a precision search for direct CP violation in charged kaon decays
are presented.


title: Noncommutative Conformal Field Theory in the Twist-deformed context

abstract:
  We discuss conformal symmetry on the two dimensional noncommutative plane
equipped with Moyal product in the twist deformed context. We show that the
consistent use of the twist procedure leads to results which are free from
ambiguities. This lends support to the importance of the use of twist
symmetries in noncommutative geometry.


title:
INTEGRAL and BeppoSAX observations of the transient atoll source 4U
  1608-522: from quiescent to hard spectral state

abstract:
  In this paper we report on the spectral evolution of 4U 1608-522 performed as
part of the long Galactic Bulge monitoring with INTEGRAL. The data set include
the April 2005 outburst. BeppoSAX archival data (two observations, in 1998 and
2000) have been also analysed and compared with the INTEGRAL ones. Three
different spectral states have been identified from the hard Color-Intensity
diagram derived from INTEGRAL: the canonical Hard and Soft as well as an
Intermediate state. The hard state spectrum is well described by a weak black
body component plus a Comptonised plasma component with high electron
temperature (kTe~60 keV) extending up to 200 keV without any additional
cut-off. The soft spectra are characterized by a cold Comptonised plasma (kTe=
2-3 keV, and 7 keV for the intermediate state) and a strong disk black body
component. A reflection component, indicating reflection of the X-ray radiation
from the accretion disc, is also present in the soft state revealed by BeppoSAX
in 1998. The 2000 BeppoSAX observation revealed the source in quiescent state
modelled by a neutron star atmosphere (assuming a neutron star with radius 10
km and mass 1.4 Msun) with an effective temperature, kTeff of 0.1 keV plus a
power law component with Gamma~3 detected for the first time for this source.
This spectrum can also be modelled with a simple black body compatible with
emission originating from a small fraction of the NS surface of radius of 0.4
km.


title: Nonvanishing vector fields on orbifolds

abstract:
  We introduce a complete obstruction to the existence of nonvanishing vector
fields on a closed orbifold $Q$. Motivated by the inertia orbifold, the space
of multi-sectors, and the generalized orbifold Euler characteristics, we
construct for each finitely generated group $\Gamma$ an orbifold called the
space of $\Gamma$-sectors of $Q$. The obstruction occurs as the Euler-Satake
characteristics of the $\Gamma$-sectors for an appropriate choice of $\Gamma$;
in the case that $Q$ is oriented, this obstruction is expressed as a cohomology
class, the $\Gamma$-Euler-Satake class. We also acquire a complete obstruction
in the case that $Q$ is compact with boundary and in the case that $Q$ is an
open suborbifold of a closed orbifold.


title: Prospects for all-optical ultrafast muon acceleration

abstract:
  A scheme for fast, compact, and controllable acceleration of heavy particles
in vacuum has been recently proposed [F. Peano et al., New J. Phys. 10 033028
(2008)], wherein two counterpropagating laser beams with variable frequencies
drive a beat-wave structure with variable phase velocity, leading to particle
trapping and acceleration. The technique allows for fine control over the
energy distribution and the total charge of the accelerated beam, to be
obtained via tuning of the frequency variation. Here, the theoretical bases of
the acceleration scheme are described, and the possibility of applications to
ultrafast muon acceleration and to the prompt extraction of cold-muon beams is
discussed.


title:
Tolman-Oppenheimer-Volkoff equations in presence of the Chaplygin gas:
  stars and wormhole-like solutions

abstract:
  We study static solutions of the Tolman--Oppenheimer--Volkoff equations for
spherically symmetric objects (stars) living in a space filled with the
Chaplygin gas. Two cases are considered. In the normal case all solutions
(excluding the de Sitter one) realize a three-dimensional spheroidal geometry
because the radial coordinate achieves a maximal value (the "equator"). After
crossing the equator, three scenarios are possible: a closed spheroid having a
Schwarzschild-type singularity with infinite blue-shift at the "south pole", a
regular spheroid, and a truncated spheroid having a scalar curvature
singularity at a finite value of the radial coordinate. The second case arises
when the modulus of the pressure exceeds the energy density (the phantom
Chaplygin gas). There is no more equator and all solutions have the geometry of
a truncated spheroid with the same type of singularity. We consider also static
spherically symmetric configurations existing in a universe filled with the
phantom Chaplygin gas only. In this case two classes of solutions exist:
truncated spheroids and solutions of the wormhole type with a throat. However,
the latter are not asymptotically flat and possess curvature singularities at
finite values of the radial coordinate. Thus, they may not be used as models of
observable compact astrophysical objects.


title:
Prospects of long-time-series observations from Dome C for transit
  search

abstract:
  The detection of transiting extrasolar planets requires high-photometric
quality and long-duration photometric stellar time-series. In this paper, we
investigate the advantages provided by the Antarctic observing platform Dome C
for planet transit detections during its long winter period, which allows for
relatively long, uninterrupted time-series. Our calculations include limiting
effects due to the Sun and Moon, cloud coverage and the effect of reduced
photometric quality for high extinction of target fields. We compare the
potential for long time-series from Dome C with a single site in Chile, a
three-site low-latitude network as well as combinations of Dome C with Chile
and the network, respectively. Dome C is one of the prime astronomical sites on
Earth for obtaining uninterrupted long-duration observations in terms of
prospects for a high observational duty cycle. The duty cycle of a project can,
however, be significantly improved by integrating Dome C into a network of
sites.


title: On asymptotics of exchangeable coalescents with multiple collisions

abstract:
  We study the number of collisions $X_n$ of an exchangeable coalescent with
multiple collisions ($\Lambda$-coalescent) which starts with $n$ particles and
is driven by rates determined by a finite characteristic measure $\nu({\rm
d}x)=x^{-2}\Lambda({\rm d}x)$. Via a coupling technique we derive limiting laws
of $X_n$, using previous results on regenerative compositions derived from
stick-breaking partitions of the unit interval. The possible limiting laws of
$X_n$ include normal, stable with index $1\le\alpha<2$ and Mittag-Leffler
distributions. The results apply, in particular, to the case when $\nu$ is a
beta$(a-2,b)$ distribution with parameters $a>2$ and $b>0$. The approach taken
allows to derive asymptotics of three other functionals of the coalescent, the
absorption time, the length of an external branch chosen at random from the $n$
external branches, and the number of collision events that occur before the
randomly selected external branch coalesces with one of its neighbours.


title: Information Societies and Digital Divides

abstract:
  The book argues ICT are part of the set of goods and services that determine
quality of life, social inequality and the chances for economic development.
Therefore understanding the digital divide demands a broader discussion of the
place of ICT within each society and in the international system. The author
argues against the perspectives that either isolates ICT from other basic
social goods (in particular education and employment) as well as those that
argue that new technologies are luxury of a consumer society. Though the author
accepts that new technologies are not a panacea for the problems of inequality,
access to them become a condition of full integration of social life. Using
examples mainly from Latin America, the work presents some general policy
proposals on the fight against the digital divide which take in consideration
other dimensions of social inequality and access to public goods.
  Bernardo Sorj was born in Montevideo, Uruguay. He is a naturalized Brazilian,
living in Brazil since 1976. He studied anthropology and philosophy in Uruguay,
and holds a B.A. and an M.A. in History and Sociology from Haifa University,
Israel. He received his Ph.D. in Sociology from the University of Manchester in
England. Sorj was a professor at the Department of Political Science at the
Federal University of Minas Gerais and at the Institute for International
Relations, PUC/RJ. The author of 20 books and more than 100 articles, was
visiting professor and chair at many European and North American
universities...


title: A tomographic analysis of reflectometry data I: Component factorization

abstract:
  Many signals in Nature, technology and experiment have a multi-component
structure. By spectral decomposition and projection on the eigenvectors of a
family of unitary operators, a robust method is developed to decompose a
signals in its components. Different signal traits may be emphasized by
different choices of the unitary family. The method is illustrated in simulated
data and on data obtained from plasma reflectometry experiments in the tore
Supra.


title: On kappa-deformation and triangular quasibialgebra structure

abstract:
  We show that, up to terms of order 1/kappa^5, the kappa-deformed Poincare
algebra can be endowed with a triangular quasibialgebra structure. The
universal R matrix and coassociator are given explicitly to the first few
orders. In the context of kappa-deformed quantum field theory, we argue that
this structure, assuming it exists to all orders, ensures that states of any
number of identical particles, in any representation, can be defined in a
kappa-covariant fashion.


title:
Suppression of Weiss oscillations in the magnetoconductivity of
  modulated graphene monolayer

abstract:
  We have investigated the electrical transport properties of Dirac electrons
in a monolayer graphene sheet in the presence of both electric and magnetic
modulations. The effects of the modulations on quantum transport when they are
in phase and out of phase are considered. We present the energy spectrum and
the bandwidth of the Dirac electrons in the presence of both the modulations.
We determine the $\sigma_{yy}$ component of the magnetoconductivity tensor for
this system which is shown to exhibit Weiss oscillations.Asymptotic expressions
for $\sigma_{yy}$ are also calculated to better illustrate the effects of
in-phase and out-of-phase modulations.We find that the position of the
oscillations in magnetoconductivity depends on the relative strength of the two
modulations. When the two modulations are out-of-phase there is complete
suppression of Weiss oscillations for particular relative strength of the
modulations.


title: Observation of new quantum interference effect in solids

abstract:
  In order to achieve quantum interference of free electrons inside a solid, we
have modified the geometry of the solid so that de Broglie waves interfere
destructively inside the solid. Quantum interference of de Broglie waves leads
to a reduction in the density of possible quantum states of electrons inside
the solid and increases the Fermi energy level. This effect was studied
theoretically within the limit of the quantum theory of free electrons inside
the metal. It has been shown that if a metal surface is modified with patterned
indents, the Fermi energy level will increase and consequently the electron
work function will decrease. This effect was studied experimentally in both Au
and SiO2 thin films of special geometry and structure. Work function reductions
of 0.5 eV in Au films and 0.2 eV in SiO2 films were observed. Comparative
measurements of work function were made using the Kelvin Probe method based on
compensation of internal contact potential difference. Electron emission from
the same thin films was studied by two independent research groups using
Photoelectron Emission Microscopy (PEEM).


title:
Distinguished representations and exceptional poles of the
  Asai-L-function

abstract:
  In this article, we proove that it is equivalent for a generic irreducible
representation of GL(n,K), with K a p-adic field, to be distinguished, and for
its Rankin-Selberg Asai L-function to have an exceptional pole at zero. This
extends a criterion of Kable claiming that a discrete series representation is
distinguished if and only if its Asai L-function has a pole at zero. As an
application we compute by local methods Asai L-functions of ordinary
representations of GL(2,K), in particular we give a formula for Asai
L-functions of principal series representations of GL(2,K).


title:
Hot spots and waves in Bi2Sr2CaCu2O8 intrinsic Josephson junction stacks
  -a study by Low Temperature Scanning Laser Microscopy

abstract:
  Recently, it has been shown that large stacks of intrinsic Josephson
junctions in Bi2Sr2CaCu2O8 emit synchronous THz radiation, the synchronization
presumably triggered by a cavity resonance. To investigate this effect we use
Low Temperature Scanning Laser Microscopy to image electric field
distributions. Apart from verifying the appearance of cavity modes at low bias
we find that, in a high input power regime, standing-wave patterns are created
through interactions with a hot spot, possibly pointing to a new mode of
generating synchronized radiation in intrinsic Josephson junction stacks.


title:
Comments on "Rates of processes with coherent production of different
  particles and the GSI time anomaly"by C. Giunti, Phys. Lett. B 665, 92
  (2008), 0805.0431

abstract:
  We give comments on the recent paper by Giunti (Phys. Lett. B 665, 92 (2008),
arXiv: 0805.0431 [hep-ph]) with a critique of our explanation of the
experimentally observed periodic time-dependence of the interference term in
the rate of the K-shell electron capture decay of the H-like ions 140Pr58+ and
142Pm60+ as a two-neutrino-flavour mixing. We show also that this phenomenon
cannot be explained by a coherent mixing of two states of a mother ion as
proposed by Giunti.


title:
Is charge noise in single electron transistors and charge qubits caused
  by metallic grains?

abstract:
  We report on measurements of low frequency noise in a single electron
transistor from a few Hz up to 10 MHz. Measurements were done for different
bias and gate voltages, which allows us to separate noise contributions from
different noise sources. We find a 1/f noise spectrum with two Lorentzians
superimposed. The cut-off frequency of one of the Lorentzians varies
systematically with the potential of the SET island. Our data is consistent
with two single-charge fluctuators situated close to the tunnel barrier. We
suggest that these are due to random charging of aluminum grains, each acting
as a single electron box with tunnel coupling to one of the leads and
capacitively coupled to the SET island. We are able to fit the data to our
model and extract parameters for the fluctuators.