title:
Entropy production in 2D $\lambda \phi^4$ theory in the Kadanoff-Baym
  approach

abstract:
  We study non-equilibrium quantum dynamics of the single-component scalar
field theory in 1+1 space-time dimensions on the basis of the Kadanoff-Baym
equation including the next-to-leading-order (NLO) skeleton diagrams. As an
extension of the non-relativistic case, we derive relativistic kinetic entropy
at the first order in the gradient expansion of the Kadanoff-Baym equations.
The derived entropy satisfies the H theorem. Next we perform numerical
simulations in spatially homogeneous configurations to investigate
thermalization properties of the system by evaluating the system entropy. We
find that at later times the kinetic entropy increases approaching the
equilibrium value, although the limited time interval in the early stage
invalidates the use of it.


title: On Stepwise Control of the Generalized Familywise Error Rate

abstract:
  A classical approach for dealing with the multiple testing problem is to
restrict attention to procedures that control the familywise error rate (FWER),
the probability of at least one false rejection. In many applications, one
might be willing to tolerate more than one false rejection provided the number
of such cases is controlled, thereby increasing the ability of the procedure to
detect false null hypotheses. This suggests replacing control of the FWER by
controlling the probability of $k$ or more false rejections, which is called
the $k$-FWER. In this article, a unified approach is presented for deriving the
$k$-FWER controlling procedures. We first generalize the well-known closure
principle in the context of the FWER to the case of controlling the $k$-FWER.
Then, we discuss how to derive the $k$-FWER controlling stepwise (stepdown or
stepup) procedures based on marginal $p$-values using this principle. We show
that, under certain conditions, generalized closed testing procedures can be
reduced to stepwise procedures, and any stepwise procedure is equivalent to a
generalized closed testing procedure. Finally, we generalize the well-known
Hommel procedure in two directions, and show that any generalized Hommel
procedure is equivalent to a generalized closed testing procedure with the same
critical values.


title: Ferroplasmas: Magnetic Dust Dynamics in a Conducting Fluid

abstract:
  We consider a dusty plasma, in which the dust particles have a magnetic
dipole moment. A Hall-MHD type of model, generalized to account for the
intrinsic magnetization, is derived. The model is shown to be energy
conserving, and the energy density and flux is derived. The general dispersion
relation is then derived, and we show that kinetic Alfv\'en waves exhibit an
instability for a low temperature and high density plasma. We discuss the
implication of our results.


title: Gauge coupling constant, compositeness and supersymmetry

abstract:
  We point out the possibility that the magnitude of the bare gauge coupling
constant is determined theoretically in a composite model of all particles in
SUSY theories. We show explicitly in two space-time dimensions that the NL/L
SUSY relation (i.e., a SUSY compositeness condition for all particles) between
N = 2 LSUSY QED and N = 2 NLSUSY determines the magnitude of the bare
electromagnetic coupling constant (i.e., the fine structure constant) of N = 2
LSUSY QED.


title:
Azimuthal asymmetries in Deeply Virtual Compton Scattering on an
  unpolarized proton target

abstract:
  Preliminary results on azimuthal asymmetries in leptoproduction of real
photons on an unpolarized hydrogen target measured at the HERMES experiment are
presented. The analysis of data taken with different beam charges and
helicities allows for a simultaneous extraction of asymmetries originating from
the interference term and the squared DVCS amplitude. Sizeable asymmetry
amplitudes for the first cosine moment of the beam-charge asymmetry and the
first sine moment of the beam-spin asymmetry have been found. The results are
compared to different theoretical calculations.


title: Lightlike p-Branes: Mass "Inflation" and Lightlike Braneworlds

abstract:
  Lagrangian description of lightlike p-branes is presented in two equivalent
forms - a Polyakov-type formulation and a dual to it Nambu-Goto-type
formulation. Next, the properties of lightlike brane dynamics in generic
gravitational backgrounds of spherically symmetric and axially symmetric type
are discussed in some detail: "horizon straddling" and "mass inflation" effects
for codimension-one lightlike branes and ground state behavior of
codimension-two lightlike "braneworlds".


title:
On an elliptic system with symmetric potential possessing two global
  minima

abstract:
  We consider the system {\Delta}u - W_u (u) = 0, for u: R^2 -> R^2, W: R^2 ->
R, where W_u (u) is a smooth potential, symmetric with respect to the u_1, u_2
axes, possessing two global minima a^\pm := (\pma,0) and two connections
e^\pm(x_1) connecting the minima. We prove that there exists an equivariant
solution u(x_1, x_2) satisfying u(x_1, x_2) -> a^\pm, as x_1 -> \pminfiniti,
and u(x_1, x_2) -> e^\pm(x_1), as x_2 -> \pminfiniti. The problem above was
first studied by Alama, Bronsard, and Gui under related hypotheses to the ones
introduced in the present paper. At the expense of one extra symmetry
assumption, we avoid their considerations with the normalized energy and
strengthen their result. We also provide examples for W.


title: On concrete models for local operator spaces

abstract:
  In this short note, we propose a concrete analogue of the space $\cL(H)$ for
local operator spaces, the multinormed $C^*$-algebra
$\displaystyle\prod_{\alpha} \cL(H_{\alpha})$.


title: Supersonic Cloud Collision - I

abstract:
  It has long been suggested that shocks might play an important role in
altering the form of the interstellar medium (ISM). Shocks enhance gas density
and sufficiently dense regions may become self gravitating. Potential star
forming clouds within larger molecular clouds, move randomly at supersonic
speeds.
  Depending on the precollision velocity, colliding molecular clouds produce a
slab that is either shock compressed or pressure confined. In a sequel of two
papers (I & II), we simulate molecular cloud collision and investigate the
dynamical evolution of such slabs. Shocked slabs are susceptible to
hydrodynamic instabilities and in the present paper (I) we study the effect of
strong shear between slab layers on the dynamic evolution of a shock compressed
gas slab. Both, head-on and off-centre cloud collisions have been examined in
this work. We include self gravity in all our simulations.
  Simulations presented here, are performed using the smoothed particle
hydrodynamics (SPH) numerical scheme. Individual, pre-collision clouds are
modelled as pressure confined Bonnor-Ebert spheres. However, in the interest of
brevity the thermodynamic details of the problem are simplified and the gas
temperature is simply evolved by a barytropic equation of state. Obviously, the
gas, to some extent suffers from thermal inertial effects. However, we note
that the dynamical timescale is much smaller than the local sound crossing time
so that such effects should have minimum influence.


title: Mean Curvature flow in Higher Co-dimension

abstract:
  We make several improvements on the results of M.-T. Wang in [8] and his
joint paper with M.-P. Tsui [7] concerning the long time existence and
convergence for solutions of mean curvature flow in higher co-dimension. Both
the curvature condition and lower bound of $*\Omega$ are weakened. New
applications are also obtained.


title:
Colossal magnetocapacitive effect in differently synthesized and doped
  CdCr2S4

abstract:
  In the present work, we address the question of an impurity-related origin of
the colossal magnetocapacitive effect in the spinel system CdCr2S4. We
demonstrate that a strong variation in the dielectric constant below the
magnetic transition temperature or in external magnetic fields also arises in
crystals prepared without chlorine. This excludes that an inhomogeneous
distribution of chlorine impurities at the surface or in the bulk material
gives rise to the unusual effects in the spinel multiferroics. In addition, we
show that colossal magnetocapacitive effects can be also generated in
chlorine-free ceramic samples of CdCr2S4, doped with indium.


title: Contact pair structures and associated metrics

abstract:
  We introduce the notion of contact pair structure and the corresponding
associated metrics, in the same spirit of the geometry of almost contact
structures. We prove that, with respect to these metrics, the integral curves
of the Reeb vector fields are geodesics and that the leaves of the Reeb action
are totally geodesic. Mreover, we show that, in the case of a metric contact
pair with decomposable endomorphism, the characteristic foliations are
orthogonal and their leaves carry induced contact metric structures.


title: Analytical Bethe ansatz for the open AdS/CFT SU(1|1) spin chain

abstract:
  We prove an inversion identity for the open AdS/CFT SU(1|1) quantum spin
chain which is exact for finite size. We use this identity, together with an
analytic ansatz, to determine the eigenvalues of the transfer matrix and the
corresponding Bethe ansatz equations. We also solve the closed chain by
algebraic Bethe ansatz.


title: Quantum Measurements with Dynamically Bistable System

abstract:
  Periodically modulated nonlinear oscillators often display bistability of
forced vibrations. This bistability can be used for new types of quantum
measurements. They are based on switching between coexisting vibrational
states. Since switching is accompanied by a large change of the amplitude and
phase of forced vibrations, the measurements are highly sensitive. Quantum and
classical noise plays dual role. It imposes a limitation on sensitivity in the
familiar regime of a bifurcation amplifier. On the other hand, it makes it
possible to use a bistable modulated oscillator in a new regime of a balanced
dynamical bridge. We discuss the switching probabilities and show that they
display scaling with control parameters. The critical exponents are found for
different types of bifurcations and for different types of noise.


title: Anomalous magnetization behavior in Ce(Fe,Si)2

abstract:
  We report the effect of Si doping on the magnetization behavior of CeFe2. It
is found that Si stabilizes the dynamic antiferromagnetic state of CeFe2.
Multi-step magnetization behavior, unusual relaxation effect, thermal and
magnetic history dependence, which are signatures of martensitic scenario, are
found to be present in this system. We also show that one can induce the
magnetization steps with the help of appropriate measurement protocol. Detailed
magnetization relaxation studies have been carried out to understand the
dynamics of magnetic phase transition.


title:
Dark energy, exotic matter and properties of horizons in black hole
  physics and cosmology

abstract:
  We summarize recent results on the properties of near-horizon metrics in
different spherically symmetric space-times, including Kantowski-Sachs
cosmological models whose evolution begins with a horizon (the so-called Null
Big Bang) and static metrics related to black holes. We describe the types of
matter compatible with cosmological and black-hole horizons. It turns out, in
particular, that a black hole horizon can be in equilibrium with a fluid of
disordered cosmic strings ("black holes can have curly hair"). We also discuss
different kinds of horizons from the viewpoint of the behavior of tidal forces
acting on an extended body and recently classified as "usual", "naked" and
"truly naked" ones; in the latter case, tidal forces are infinite in a freely
falling reference frame. It is shown that all truly naked horizons, as well as
many of those previously characterized as naked and even usual ones, do not
admit an extension and therefore must be considered as singularities. The whole
analysis is performed locally (in a neighborhood of a candidate horizon) in a
model-independent manner. Finally, the possible importance of some of these
models in generating dynamic, perturbatively small vacuum fluctuation
contributions to the cosmological constant (within a cosmological
Casimir-effect approach to this problem) is discussed.


title: Encoding information into precipitation structures

abstract:
  Material design at submicron scales would be profoundly affected if the
formation of precipitation patterns could be easily controlled. It would allow
the direct building of bulk structures, in contrast to traditional techniques
which consist of removing material in order to create patterns. Here, we
discuss an extension of our recent proposal of using electrical currents to
control precipitation bands which emerge in the wake of reaction fronts in
A^{+} + B^{-} -> C reaction-diffusion processes. Our main result, based on
simulating the reaction-diffusion-precipitation equations, is that the dynamics
of the charged agents can be guided by an appropriately designed time-dependent
electric current so that, in addition to the control of the band spacing, the
width of the precipitation bands can also be tuned. This makes straightforward
the encoding of information into precipitation patterns and, as an amusing
example, we demonstrate the feasibility by showing how to encode a musical
rhythm.

categories: cond-mat.stat-mech cond-mat.mtrl-sci nlin.PS physics.chem-ph


title: Electron temperature fluctuations in NGC 346

abstract:
  The existence and origin of large spatial temperature fluctuations in HII
regions and planetary nebulae are assumed to explain the differences between
the heavy element abundances inferred from collisionally excited and
recombination lines, although this interpretation remains significantly
controversial. We investigate the spatial variation in electron temperature
inside NGC 346, the brightest HII region in the Small Magellanic Cloud. Long
slit spectrophotometric data of high signal-to-noise were employed to derive
the electron temperature from measurements derived from localized observations
of the [OIII]($\lambda4959 + \lambda5007)/\lambda4363$ ratio in three
directions across the nebula. The electron temperature was estimated in 179
areas of 5$^{\prime\prime}\times1.5^{\prime\prime}$ of size distributed along
three different declinations. A largely homogeneous temperature distribution
was found with a mean temperature of 12 269 K and a dispersion of 6.1%. After
correcting for pure measurements errors, a temperature fluctuation on the plane
of the sky of $t^2_{\rm s} = 0.0021$ (corresponding to a dispersion of 4.5%)
was obtained, which indicates a 3D temperature fluctuation parameter of $t^2
\approx 0.008$. A large scale gradient in temperature of the order of
$-5.7\pm1.3$ K arcsec$^{-1}$ was found. The magnitude of the temperature
fluctuations observed agrees with the large scale variations in temperature
predicted by standard photoionization models, but is too small to explain the
abundance discrepancy problem. However, the possible existence of small spatial
scale temperature variations is not excluded.


title:
Exotic Collective Excitations at High Spin: Triaxial Rotation and
  Octupole Condensation

abstract:
  In this thesis work, two topics, triaxiality and reflection asymmetry, have
been discussed. Band structures in $^{163}$Tm were studied in a "thin" target
experiment as well as in a DSAM lifetime measurement. Two new excited bands
were shown to be characterized by a deformation larger than that of the yrast
sequence. These structures have been interpreted as Triaxial Strongly Deformed
bands associated with particle-hole excitations, rather than with wobbling.
Moreover, the Tilted-Axis Cranking calculations provide a natural explanation
for the presence of wobbling bands in the Lu isotopes and their absence in the
neighboring Tm, Hf and Ta nuclei. A series of so-called "unsafe" Coulomb
excitation experiments as well as one-neutron transfer measurements was carried
out to investigate the role of octupole correlations in the $^{238,240,242}$Pu
isotopes. Some striking differences exist between the level scheme and
deexcitation patterns seen in $^{240}$Pu, and to a lesser extent in $^{238}$Pu,
and those observed in $^{242}$Pu and in many other actinide nuclei such as
$^{232}$Th and $^{238}$U, for example. The differences can be linked to the
strength of octupole correlations, which are strongest in $^{240}$Pu. Further,
all the data find a natural explanation within the recently proposed
theoretical framework of octupole condensation.


title: Excitation and damping of p-mode oscillations of alpha Cen B

abstract:
  This paper presents an analysis of observational data on the p-mode spectrum
of the star alpha Cen B and a comparison with theoretical computations of the
stochastic excitation and damping of the modes. We find that at frequencies >
4500 micro-Hz, the model damping rates appear to be too weak to explain the
observed shape of the power spectral density of alpha Cen B. The conclusion
rests on the assumption that most of the disagreement is due to problems
modelling the damping rates, not the excitation rates, of the modes. This
assumption is supported by a parallel analysis of BiSON Sun-as-a-star data, for
which it is possible to use analysis of very long timeseries to place tight
constraints on the assumption. The BiSON analysis shows that there is a similar
high-frequency disagreement between theory and observation in the Sun.
  We demonstrate that by using suitable comparisons of theory and observation
it is possible to make inference on the dependence of the p-mode linewidths on
frequency, without directly measuring those linewidths, even though the alpha
Cen B dataset is only a few nights long. Use of independent measures from a
previous study of the alpha Cen B linewidths in two parts of its spectrum also
allows us to calibrate our linewidth estimates for the star. The resulting
calibrated linewidth curve looks similar to a frequency-scaled version of its
solar cousin, with the scaling factor equal to the ratio of the respective
acoustic cut-off frequencies of the two stars. The ratio of the frequencies at
which the onset of high-frequency problems is seen in both stars is also given
approximately by the same scaling factor.


title: Jump-Diffusions in Hilbert Spaces: Existence, Stability and Numerics

abstract:
  By means of an original approach, called "method of the moving frame", we
establish existence, uniqueness and stability results for mild and weak
solutions of stochastic partial differential equations (SPDEs) with path
dependent coefficients driven by an infinite dimensional Wiener process and a
compensated Poisson random measure. Our approach is based on a time-dependent
coordinate transform, which reduces a wide class of SPDEs to a class of simpler
SDE problems. We try to present the most general results, which we can obtain
in our setting, within a self-contained framework to demonstrate our approach
in all details. Also several numerical approaches to SPDEs in the spirit of
this setting are presented.


title: Operators in ultraviolet completions for collective symmetry breaking

abstract:
  We investigate the Lagrangian terms of scalar-gauge interactions in a
weakly-coupled gauge theory beyond the ultraviolet momentum cutoff of models
where the collective symmetry breaking mechanism protects the Higgs mass
squared against having quadratic divergence. We also propose a five-dimensional
model in which the gauge symmetry breaking is achieved by boundary conditions
consistent with local gauge transformations. It is shown that the scalar-gauge
operators in the two models differ in the absence of quadratic divergence.


title:
The radio remnant of SN1993J: an instrumental explanation for the
  evolving complex structure

abstract:
  We present simulated images of Supernova 1993J at 8.4 GHz using Very Long
Baseline Interferometry (VLBI) techniques. A spherically symmetric source model
is convolved with realistic uv-plane distributions, together with standard
imaging procedures, to assess the extent of instrumental effects on the
recovered brightness distribution. In order to facilitate direct comparisons
between the simulations and published VLBI images of SN1993J, the observed
uv-coverage is determined from actual VLBI observations made in the years
following its discovery.
  The underlying source model only exhibits radial variation in its density
profile, with no azimuthal dependence and, even though this model is
morphologically simple, the simulated VLBI observations qualitatively reproduce
many of the azimuthal features of the reported VLBI observations, such as
appearance and evolution of complex azimuthal structure and apparent rotation
of the shell. We demonstrate that such features are inexorably coupled to the
uv-plane sampling.
  The brightness contrast between the peaks and the surrounding shell material
are not as prominent in the simulations (which of course assume no antenna- or
baseline-based amplitude or phase errors, meaning no self-calibration
procedures will have incorporated any such features in models). It is
conclusive that incomplete uv-plane sampling has a drastic effect on the final
images for observations of this nature. Difference imaging reveals residual
emission up to the 8 sigma level. Extreme care should be taken when using
interferometric observations to directly infer the structure of objects such as
supernovae.


title: Disentangling the Nature of the Radio Emission in Wolf Rayet Stars

abstract:
  We present quasi-simultaneous, multi-frequency VLA observations at 4.8, 8.4,
and 22.5 GHz, of a sample of 13 Wolf Rayet (WR) stars, aimed at disentangling
the nature of their radio emission and the possible detection of a non-thermal
behavior in close binary systems. We detected 12 stars from our sample, for
which we derived spectral information and estimated their mass loss rates. From
our data, we identified four thermal sources (WR 89, 113, 138, and 141), and
three sources with a composite spectrum (similar contribution of thermal and
non-thermal emission; WR 8, 98, and 156). On the other hand, from the
comparison with previous observations, we confirm the non-thermal spectrum of
one (WR 105), and also found evidence of a composite spectrum for WR 79a, 98a,
104, and 133. Finally, we discuss the possible scenarios to explain the nature
of the emission for the observed objects.


title:
Prescribing curvatures on three dimensional Riemannian manifolds with
  boundaries

abstract:
  Let $(M,g)$ be a complete three dimensional Riemannian manifold with boundary
$\partial M$. Given smooth functions $K(x)>0$ and $c(x)$ defined on $M$ and
$\partial M$, respectively, it is natural to ask whether there exist metrics
conformal to $g$ so that under these new metrics, $K$ is the scalar curvature
and $c$ is the boundary mean curvature. All such metrics can be described by a
prescribing curvature equation with a boundary condition. With suitable
assumptions on $K$,$c$ and $(M,g)$ we show that all the solutions of the
equation can only blow up at finite points over each compact subset of $\bar
M$, some of them may appear on $\partial M$. We describe the asymptotic
behavior of the blowup solutions around each blowup point and derive an energy
estimate as a consequence.


title: New EUV Fe IX emission line identifications from Hinode/EIS

abstract:
  Four Fe IX transitions in the wavelength range 188--198 A are identified for
the first time in spectra from the EUV Imaging Spectrometer on board the Hinode
satellite. In particular the emission line at 197.86 A is unblended and close
to the peak of the EIS sensitivity curve, making it a valuable diagnostic of
plasma at around 800,000 K - a critical temperature for studying the interface
between the corona and transition region. Theoretical ratios amongst the four
lines predicted from the CHIANTI database reveal weak sensitivity to density
and temperature with observed values consistent with theory. The ratio of
197.86 relative to the 171.07 resonance line of Fe IX is found to be an
excellent temperature diagnostic, independent of density, and the derived
temperature in the analysed data set is log T=5.95, close to the predicted
temperature of maximum ionization of Fe IX.


title: On the Calder\'on-Zygmund lemma for Sobolev functions

abstract: We correct an inaccuracy in the original proof


title: Localisation de faisceaux caract\`eres

abstract:
  Nous obtenons une formule pour les valeurs de la fonction caract\'eristique
d'un faisceau caract\`ere en fonction de la th\'eorie des repr\'esentations de
certains groupes finis, li\'es au groupe de Weyl. Cette formule, qui
g\'en\'eralise des r\'esultats ant\'erieurs de M{\oe}glin et de Waldspurger,
d\'epend de la connaissance de certains sous-groupes r\'eductifs admettant un
faisceau caract\`ere cuspidal. Dans un second temps, afin de rendre la formule
plus explicite dans le cas d'un groupe quasi-simple, nous d\'eterminons ces
sous-groupes \`a conjugaison pr\`es.
  We obtain a formula for the values of the characteristic function of a
character sheaf, in terms of the representation theory of certain finite groups
related to the Weyl group. This formula, a generalization of previous results
due to M{\oe}glin and Waldspurger, depends on knowledge of certain reductive
subgroups that admit cuspidal character sheaves. For quasi-simple groups, we
make the formula truly explicit by determining all such subgroups upto
conjugation.


title: Addendum to "Maximal regularity and Hardy spaces"

abstract:
  We correct an inaccuracy in a previous article [Auscher, Pascal; Bernicot,
Fr\'ed\'eric; Zhao, Jiman. Maximal regularity and Hardy spaces. Collect. Math.
59 (2008), no. 1, 103-127.]


title: Uniqueness of Morava K-theory

abstract:
  We show that there is an essentially unique S-algebra structure on the Morava
K-theory spectrum K(n), while K(n) has uncountably many MU or \hE{n}-algebra
structures. Here \hE{n} is the K(n)-localized Johnson-Wilson spectrum. To prove
this we set up a spectral sequence computing the homotopy groups of the moduli
space of A-infinity structures on a spectrum, and use the theory of S-algebra
k-invariants for connective S-algebras due to Dugger and Shipley to show that
all the uniqueness obstructions are hit by differentials.


title: Cold Reactions of Alkali and Water Clusters inside Helium Nanodroplets

abstract:
  The reaction of alkali (Na, Cs) clusters with water clusters embedded in
helium nanodroplets is studied using femtosecond photo-ionization as well as
electron impact ionization. Unlike Na clusters, Cs clusters are found to
completely react with water in spite of the ultracold helium droplet
environment. Mass spectra of the Cs$_n$+(H$_2$O)$_m$ reaction products are
interpreted in terms of stability with respect to fragmentation using
high-level molecular structure calculations.


title:
Entanglement Dynamics in Two-Qubit Open System Interacting with a
  Squeezed Thermal Bath via Quantum Nondemolition interaction

abstract:
  We analyze the dynamics of entanglement in a two-qubit system interacting
with an initially squeezed thermal environment via a quantum nondemolition
system-reservoir interaction, with the system and reservoir assumed to be
initially separable. We compare and contrast the decoherence of the two-qubit
system in the case where the qubits are mutually close-by (`collective regime')
or distant (`localized regime') with respect to the spatial variation of the
environment. Sudden death of entanglement (as quantified by concurrence) is
shown to occur in the localized case rather than in the collective case, where
entanglement tends to `ring down'. A consequence of the QND character of the
interaction is that the time-evolved fidelity of a Bell state never falls below
$1/\sqrt{2}$, a fact that is useful for quantum communication applications like
a quantum repeater. Using a novel quantification of mixed state entanglement,
we show that there are noise regimes where even though entanglement vanishes,
the state is still available for applications like NMR quantum computation,
because of the presence of a pseudo-pure component.


title:
Consistent estimation of the critical current density of a
  superconductor from hysteresis loops

abstract:
  It has been noticed that the critical current density Jc of some of the
superconducting samples, calculated on the basis of Bean model, increases with
increasing magnetic field H up to a significant range above H=0. This is an
inconsistent behavior of Jc since the theory of Kim and the theories based on
vortex dynamics, all, lead to decreasing Jc with increasing H for H > 0. It has
been argued that a realistic variation of Jc for low H may be obtained within
Bean framework by redefining the width of the hysteresis loop. The new
definition of the loop width is guided by the requirement that Jc stays as
close to the Jc of the theory of Kim as possible. Illustrative calculations of
Jc show its considerable enhancement over the Bean values.


title: Dehn twists have roots

abstract: We construct nontrivial roots of Dehn twists about nonseparating curves.


title: Discretely Holomorphic Parafermions and Integrable Loop Models

abstract:
  We define parafermionic observables in various lattice loop models, including
examples where no Kramers-Wannier duality holds. For a particular rhombic
embedding of the lattice in the plane and a value of the parafermionic spin
these variables are discretely holomorphic (they satisfy a lattice version of
the Cauchy-Riemann equations) as long as the Boltzmann weights satisfy certain
linear constraints. In the cases considered, the weights then also satisfy the
critical Yang-Baxter equations, with the spectral parameter being related
linearly to the angle of the elementary rhombus.


title:
Scalar-tensor cosmologies: general relativity as a fixed point of the
  Jordan frame scalar field

abstract:
  We study the evolution of homogeneous and isotropic, flat cosmological models
within the general scalar-tensor theory of gravity with arbitrary coupling
function and potential and scrutinize its limit to general relativity. Using
the methods of dynamical systems for the decoupled equation of the Jordan frame
scalar field we find the fixed points of flows in two cases: potential
domination and matter domination. We present the conditions on the mathematical
form of the coupling function and potential which determine the nature of the
fixed points (attractor or other). There are two types of fixed points, both
are characterized by cosmological evolution mimicking general relativity, but
only one of the types is compatible with the Solar System PPN constraints.


title: Deformed spaces and loop cosmology

abstract:
  The non-singular bouncing solution of loop quantum cosmology is reproduced by
a deformed minisuperspace Heisenberg algebra. This algebra is a realization of
the Snyder space, is almost unique and is related to the $\kappa$-Poincar\'e
one. Since the sign of the deformation parameter it is not fixed, the Friedmann
equation of braneworlds theory can also be obtained. Moreover, the sign is the
only freedom in the picture and these frameworks are the only ones which can be
reproduced by our deformed scheme. A generalized uncertainty principle for loop
quantum cosmology is also proposed.


title:
On completeness of description of an equilibrium canonical ensemble by
  reduced s-particle distribution function

abstract:
  In this article it is shown that in a classical equilibrium canonical
ensemble of molecules with $s$-body interaction full Gibbs distribution can be
uniquely expressed in terms of a reduced s-particle distribution function. This
means that whenever a number of particles $N$ and a volume $V$ are fixed the
reduced $s$-particle distribution function contains as much information about
the equilibrium system as the whole canonical Gibbs distribution. The latter is
represented as an absolutely convergent power series relative to the reduced
$s$-particle distribution function. As an example a linear term of this
expansion is calculated. It is also shown that reduced distribution functions
of order less than $s$ don't possess such property and, to all appearance,
contain not all information about the system under consideration.


title: Explicit birational geometry of 3-folds of general type, I

abstract:
  Let $V$ be a complex nonsingular projective 3-fold of general type. We prove
$P_{12}(V):=\text{dim} H^0(V, 12K_V)>0$ and $P_{m_0}(V)>1$ for some positive
integer $m_0\leq 24$. A direct consequence is the birationality of the
pluricanonical map $\varphi_m$ for all $m\geq 126$. Besides, the canonical
volume $\text{Vol}(V)$ has a universal lower bound $\nu(3)\geq \frac{1}{63\cdot
126^2}$.


title:
A characterization of sub-riemannian spaces as length dilatation
  structures constructed via coherent projections

abstract:
  We introduce length dilatation structures on metric spaces, tempered
dilatation structures and coherent projections and explore the relations
between these objects and the Radon-Nikodym property and Gamma-convergence of
length functionals. Then we show that the main properties of sub-riemannian
spaces can be obtained from pairs of length dilatation structures, the first
being a tempered one and the second obtained via a coherent projection.
  Thus we get an intrinsic, synthetic, axiomatic description of sub-riemannian
geometry, which transforms the classical construction of a Carnot-Caratheodory
distance on a regular sub-riemannian manifold into a model for this abstract
sub-riemannian geometry.


title: On global H\"older estimates for optimal transportation

abstract:
  We generalize a well-known result of L. Caffarelli on Lipschitz estimates for
optimal transportation $T$ between uniformly log-concave probability measures.
Let $T : \R^d \to \R^d$ be an optimal transportation pushing forward $\mu =
e^{-V}dx$ to $\nu = e^{-W}dx$. Assume that 1) the second differential quotient
of $V$ can be estimated from above by a power function, 2) modulus of convexity
of $W$ can be estimated from below by $A_q |x|^{1+q}$, $q \ge 1$. Under these
assumptions we show that $T$ is globally H\"older with a dimension-free
coefficient. In addition, we study optimal transportation $T$ between $\mu$ and
the uniform measure on a bounded convex set $K \subset \R^d$. We get estimates
for the Lipschitz constant of $T$ in terms of $d$, ${diam(K)}$ and $D V, D^2
V$.


title: Explicit birational geometry of 3-folds of general type, II

abstract:
  Let $V$ be a complex nonsingular projective 3-fold of general type. We shall
give a detailed classification up to baskets of singularities on a minimal
model of $V$. We show that the $m$-canonical map of $V$ is birational for all
$m\geq 73$ and that the canonical volume $\text{Vol}(V)\geq {1/2660}$. When
$\chi(\mathcal{O}_V)\leq 1$, our result is $\text{Vol}(V)\geq {1/420}$, which
is optimal. Other effective results are also included in the paper.


title:
Well-Posedness of the Einstein-Euler System in Asymptotically Flat
  Spacetimes

abstract:
  We prove a local in time existence and uniqueness theorem of classical
solutions of the coupled Einstein--Euler system, and therefore establish the
well posedness of this system. We use the condition that the energy density
might vanish or tends to zero at infinity and that the pressure is a certain
function of the energy density, conditions which are used to describe
simplified stellar models. In order to achieve our goals we are enforced, by
the complexity of the problem, to deal with these equations in a new type of
weighted Sobolev spaces of fractional order. Beside their construction, we
develop tools for PDEs and techniques for elliptic and hyperbolic equations in
these spaces. The well posedness is obtained in these spaces. The results
obtained are related to and generalize earlier works of Rendall for the
Euler-Einstein system under the restriction of time symmetry and of Gamblin for
the simpler Euler--Poisson system.


title: Superfluid Bose-Fermi mixture from weak-coupling to unitarity

abstract:
  We investigate the zero-temperature properties of a superfluid Bose-Fermi
mixture by introducing a set of coupled Galilei-invariant nonlinear
Schr\"odinger equations valid from weak-coupling to unitarity. The Bose
dynamics is described by a Gross-Pitaevskii-type equation including
beyond-mean-field corrections possessing the correct weak-coupling and
unitarity limits. The dynamics of the two-component Fermi superfluid is
described by a density-functional equation including beyond-mean-field terms
with correct weak-coupling and unitarity limits. The present set of equations
is equivalent to the equations of generalized superfluid hydrodynamics, which
take into account also surface effects. The equations describe the mixture
properly as the Bose-Bose repulsive (positive) and Fermi-Fermi attractive
(negative) scattering lengths are varied from zero to infinity in the presence
of a Bose-Fermi interaction. The present model is tested numerically as the
Bose-Bose and Fermi-Fermi scattering lengths are varied over wide ranges
covering the weak-coupling to unitarity transition.


title: L2-Homogenization of Heat Equations on Tubular Neighborhoods

abstract:
  We consider the heat equation with Dirichlet boundary conditions on the
tubular neighborhood of a closed Riemannian submanifold. We show that, as the
tube radius decreases, the semigroup of a suitably rescaled and renormalized
generator can be effectively described by a Hamiltonian on the submanifold with
a potential that depends on the geometry of the submanifold and of the
embedding.


title:
Nitrogen defects and ferromagnetism of Cr-doped AlN diluted magnetic
  semiconductor from first principles

abstract:
  High Curie temperature of 900 K has been reported in Cr-doped AlN diluted
magnetic semiconductors prepared by various methods, which is exciting for
spintronic applications. It is believed that N defects play important roles in
achieving the high temperature ferromagnetism in good samples. Motivated by
these experimental advances, we use a full-potential density-functional-theory
method and supercell approach to investigate N defects and their effects on
ferromagnetism of (Al,Cr)N with N vacancies (V_N). Calculated results are in
agreement with experimental observations and facts of real Cr-doped AlN samples
and their synthesis. Our first-principles results are useful to elucidating the
mechanism for the ferromagnetism and exploring high-performance Cr-doped AlN
diluted magnetic semiconductors.


title:
Striped antiferromagnetism and electronic structures of SrFeAsF and
  their implications

abstract:
  We investigate structural, magnetic, and electronic properties of SrFeAsF as
a new parent for superconductors using state-of-the-art density-functional
theory method. Calculated results show that striped antiferromagnetic order is
the magnetic ground state in the Fe layer and interlayer magnetic interaction
is tiny. Calculated As and Sr positions are in agreement with experiment. There
are only two uniaxially-dispersed bands near the Fermi level. The valent charge
is mainly in the Fe and F layers, and the magnetic moment is confined to the Fe
atoms. Inter-Fe-spin couplings is due to superexchange through As atoms. These
are useful to understanding the SrFeAsF and should have helpful implications to
doped samples.


title:
Vulnerability of "A novel protocol-authentication algorithm ruling out a
  man-in-the-middle attack in Quantum Cryptography"

abstract:
  In this paper we review and comment on "A novel protocol-authentication
algorithm ruling out a man-in-the-middle attack in quantum cryptography", [M.
Peev et al., Int. J. Quant. Inform., 3, 225, (2005)]. In particular, we point
out that the proposed primitive is not secure when used in a generic protocol,
and needs additional authenticating properties of the surrounding
quantum-cryptographic protocol.


title:
Study of Warm Electron Injection in Double Gate SONOS by Full Band Monte
  Carlo Simulation

abstract:
  In this paper we investigate warm electron injection in a double gate SONOS
memory by means of 2D full-band Monte Carlo simulations of the Boltzmann
Transport Equation (BTE). Electrons are accelerated in the channel by a
drain-to-source voltage VDS smaller than 3 V, so that programming occurs via
electrons tunneling through a potential barrier whose height has been
effectively reduced by the accumulated kinetic energy. Particle energy
distribution at the semiconductor/oxide interface is studied for different bias
conditions and different positions along the channel. The gate current is
calculated with a continuum-based post-processing method as a function of the
particle distribution obtained from Monte Carlo. Simulation results show that
the gate current increases by several orders of magnitude with increasing drain
bias and warm electron injection can be an interesting option for programming
when short channel effects prohibit the application of larger drain bias.


title: Smooth Homogenization of Heat Equations on Tubular Neighborhoods

abstract:
  We consider the heat equation with Dirichlet boundary conditions on the
tubular neighborhood of a closed Riemannian submanifold. We show that, as the
tube diameter tends to zero, a suitably rescaled and renormalized semigroup
converges to a limit semigroup in Sobolev spaces of arbitrarily large Sobolev
index.


title: Origin of undesirable cracks during layer transfer

abstract:
  We investigate the origin of undesirable transverse cracks often observed in
thin films obtained by the layer transfer technique. During this process, two
crystals bonded to each other containing a weak plan produced by ion
implantation are heated to let a thin layer of one of the material on the
other. The level of stress imposed on the film during the heating phase due to
the mismatch of thermal expansion coefficients of the substrate and the film is
shown to be the relevant parameter of the problem. In particular, it is shown
that if the film is submitted to a tensile stress, the microcracks produced by
ion implantation are not stable and deviate from their straight trajectory
making the layer transfer process impossible. However, if the compressive
stress exceeds a threshold value, after layer transfer, the film can buckle and
delaminate, leading to transverse cracks induced by bending. As a result, we
show that the imposed stress \sigma_m - or equivalently the heating temperature
- must be within the range -\sigma_c < \sigma_m < 0 to produce an intact thin
film where \sigma_c depends on the interfacial fracture energy and the size of
defects at the interface between film and substrate.


title: Multipartite entanglement control via Quantum Zeno Effect

abstract:
  We develop a protocol based on 2M pairwise interacting qubits, which through
Quantum Zeno Effect controls the entanglement distribution of the system. We
also show that if the coupling constants are different the QZE may be used to
achieve perfect entanglement swap.


title:
Resolving the Structure and Kinematics of the BN Object at $0\rlap.{"}2$
  Resolution

abstract:
  We present sensitive 7 mm observations of the H53$\alpha$ recombination line
and adjacent continuum, made toward the Orion BN/KL region. In the continuum we
detect the BN object, the radio source I (GMR I) and the radio counterpart of
the infrared source n (Orion-n). Comparing with observations made at similar
angular resolutions but lower frequency, we discuss the spectral indices and
angular sizes of these sources. In the H53$\alpha$ line we only detect the BN
object. This is the first time that radio recombination lines are detected from
this source. The LSR radial velocity of BN from the H53$\alpha$ line, $v_{LSR}
= 20.1 \pm 2.1$ km s$^{-1}$, is consistent with that found from previous
studies in near-infared lines. While the continuum emission is expected to have
considerable optical depth at 7 mm, the observed H53$\alpha$ line emission is
consistent with an optically-thin nature and we discuss possible explanations
for this apparent discrepancy. There is evidence of a velocity gradient, with
the NE part of BN being redshifted by $\sim 10$ km s$^{-1}$ with respect to the
SW part. This is consistent with the suggestion of Jiang et al. that BN may be
driving an ionized outflow along that direction.


title: P is not equal to NP

abstract:
  SAT is not in P, is true and provable in a simply consistent extension B' of
a first order theory B of computing, with a single finite axiom characterizing
a universal Turing machine. Therefore, P is not equal to NP, is true and
provable in a simply consistent extension B" of B.


title:
Combining Advanced Visualization and Automatized Reasoning for
  Webometrics: A Test Study

abstract:
  This paper presents a first attempt at performing a precise and automatic
identification of the linking behaviour in a scientific domain through the
analysis of the communication of the related academic institutions on the web.
The proposed approach is based on the paradigm of multiple viewpoint data
analysis (MVDA) than can be fruitfully exploited to highlight relationships
between data, like websites, carrying several kinds of description. It uses the
MultiSOM clustering and mapping method. The domain that has been chosen for
this study is the domain of Computer Science in Germany. The analysis is
conduced on a set of 438 websites of this domain using all together, thematic,
geographic and linking information. It highlights interesting results
concerning both global and local linking behaviour.


title:
An exact property of the nonequilibrium photon Green function for
  bounded media

abstract:
  The nonequilibrium photon Green function for a bounded medium surrounded by
vacuum is analyzed on the basis of the Dyson equation. As its components, the
field-field fluctuations as well as the spectral function split up into parts
related to medium and vacuum. Particularly, it is shown that the vacuum-induced
fluctuations describe propagation of arbitrary, even nonclassical light in
terms of solutions of the classical wave propagation problem. The results
generalize previously obtained ones for steadily excited media in slab
geometry.


title:
Three-wave interactions of dispersive plasma waves propagating parallel
  to the magnetic field

abstract:
  Three-wave interactions of plasma waves propagating parallel to the mean
magnetic field at frequencies below the electron cyclotron frequency are
considered. We consider Alfv\'en--ion-cyclotron waves,
fast-magnetosonic--whistler waves, and ion-sound waves. Especially the weakly
turbulent low-beta plasmas like the solar corona are studied, using the
cold-plasma dispersion relation for the transverse waves and the
fluid-description of the warm plasma for the longitudinal waves. We analyse the
resonance conditions for the wave frequencies $\omega$ and wavenumbers $k$, and
the interaction rates of the waves for all possible combinations of the three
wave modes, and list those reactions that are not forbidden.


title: Geometry and stability of dynamical systems

abstract:
  We reconsider both the global and local stability of solutions of
continuously evolving dynamical systems from a geometric perspective. We
clarify that an unambiguous definition of stability generally requires the
choice of additional geometric structure that is not intrinsic to the dynamical
system itself. While global Lyapunov stability is based on the choice of
seminorms on the vector bundle of perturbations, we propose a definition of
local stability based on the choice of a linear connection. We show how this
definition reproduces known stability criteria for second order dynamical
systems. In contrast to the general case, the special geometry of Lagrangian
systems provides completely intrinsic notions of global and local stability. We
demonstrate that these do not suffer from the limitations occurring in the
analysis of the Maupertuis-Jacobi geodesics associated to natural Lagrangian
systems.


title:
Velocity distribution measurements in atomic beams generated using laser
  induced back-ablation

abstract:
  We present measurements of the velocity distribution of calcium atoms in an
atomic beam generated using a dual-stage laser back-ablation apparatus.
Distributions are measured using a velocity selective Doppler time-of-flight
technique. They are Boltzmann-like with rms velocities corresponding to
temperatures above the melting point for calcium. Contrary to a recent report
in the literature, this method does not generate a sub-thermal atomic beam.


title:
The dependence of HII region properties on global and local surface
  brightness within galaxy discs

abstract:
  Using B, R, and H-alpha images of roughly equal-sized samples of low surface
brightness (LSB) and high surface brightness (HSB) galaxies (~40 galaxies
apiece), we have explored the dependence of HII region properties on local and
global disc surface brightness. We have done this by constructing co-added HII
region luminosity functions (LFs) according to local and central disc surface
brightness and fitting Schechter functions to these LFs. The results show that
the shape of the HII region LF within LSB galaxies does not change noticeably
as different limiting (i.e., mu>mu_lim) local surface brightness values are
used. However, the LFs for HSB galaxies have larger values of L_* and are less
steep at the faint-end than those of LSB galaxies for limiting B-band local
surface brightness values as faint as mu_B,lim~23-24. Both the LFs and the data
for individual HII regions show that luminous (log L>39 ergs/s) HII regions are
much more common within HSB discs than within LSB discs, implying that the
newly formed star clusters are also larger. Taking this into account along with
the results of Monte Carlo simulations, the shapes of the LFs imply that the
regions within LSB discs and those within the LSB areas of HSB discs are
relatively old (~5 Myr) while the regions within HSB discs for mu_B<24 are
significantly younger (<1 Myr). Since the majority of the LSB galaxies do not
have noticeable spiral arms and the majority of the HSB galaxies do, this may
indicate a transition within HSB discs from spiral arm-driven star formation to
a more locally driven, possibly sporadic form of star formation at mu_B~24, a
transition that does not appear to occur within LSB discs.


title:
Structural properties of semilinear SPDEs driven by cylindrical stable
  processes

abstract:
  We consider a class of semilinear stochastic evolution equations driven by an
additive cylindrical stable noise.We investigate structural properties of the
solutions like Markov, irreducibility, stochastic continuity, Feller and strong
Feller properties, and study integrability of trajectories. The obtained
results can be applied to semilinear stochastic heat equations with Dirichlet
boundary conditions and bounded and Lipschitz nonlinearities.


title: A New Algorithm for Building Alphabetic Minimax Trees

abstract:
  We show how to build an alphabetic minimax tree for a sequence (W = w_1,
>..., w_n) of real weights in (O (n d \log \log n)) time, where $d$ is the
number of distinct integers (\lceil w_i \rceil). We apply this algorithm to
building an alphabetic prefix code given a sample.


title:
Trapped fermion mixtures with unequal masses: a Bogoliubov-de Gennes
  approach

abstract:
  We use the Bogoliubov-de Gennes formalism to analyze the ground state phases
of harmonically trapped two-species fermion mixtures with unequal masses. In
the weakly attracting limit and around unitarity, we find that the superfluid
order parameter is spatially modulated around the trap center, and that its
global maximum occurs at a finite distance away from the trap center where the
mixture is locally unpolarized. As the attraction strength increases towards
the molecular limit, the spatial modulations gradually disappear while the
Bardeen-Cooper-Schrieffer (BCS) type nonmodulated superfluid region expands
until the entire mixture becomes locally unpolarized.


title: The Classification of Highly Supersymmetric Supergravity Solutions

abstract:
  The spinorial geometry method is an effective method for constructing
systematic classifications of supersymmetric supergravity solutions. Recent
work on analysing highly supersymmetric solutions in type IIB supergravity
using this method is reviewed [arXiv:hep-th/0606049, arXiv:0710.1829]. It is
shown that all supersymmetric solutions of IIB supergravity with more than 28
Killing spinors are locally maximally supersymmetric.


title: Kirillov--Reshetikhin crystals for nonexceptional types

abstract:
  We provide combinatorial models for all Kirillov--Reshetikhin crystals of
nonexceptional type, which were recently shown to exist. For types D_n^(1),
B_n^(1), A_{2n-1}^(2) we rely on a previous construction using the Dynkin
diagram automorphism which interchanges nodes 0 and 1. For type C_n^(1) we use
a Dynkin diagram folding and for types A_{2n}^(2), D_{n+1}^(2) a similarity
construction. We also show that for types C_n^(1) and D_{n+1}^(2) the analog of
the Dynkin diagram automorphism exists on the level of crystals.


title: One-loop Corrections to the S Parameter in the Four-site Model

abstract:
  We compute the leading chiral-logarithmic corrections to the S parameter in
the four-site Higgsless model. In addition to the usual electroweak gauge
bosons of the Standard Model, this model contains two sets of heavy charged and
neutral gauge bosons. In the continuum limit, the latter gauge bosons can be
identified with the first excited Kaluza-Klein states of the W^\pm and Z bosons
of a warped extra-dimensional model with an SU(2)_L \times SU(2)_R \times
U(1)_X bulk gauge symmetry. We consider delocalized fermions and show that the
delocalization parameter must be considerably tuned from its tree-level ideal
value in order to reconcile experimental constraints with the one-loop results.
Hence, the delocalization of fermions does not solve the problem of large
contributions to the S parameter in this class of theories and significant
contributions to S can potentially occur at one-loop.


title: Dust and Gas as Seeds for Metal-Poor Star Formation

abstract:
  I address the issue of dust and gas as seeds for metal-poor star formation by
reviewing what we know about star formation in nearby dwarf galaxies and its
relationship to the gas and dust. I (try to) speculate on the extent to which
processes in nearby galaxies mimic star formation in the early universe.


title:
Constraints on chameleons and axion-like particles from the GammeV
  experiment

abstract:
  We present the most recent results of both aspects of the GammeV experiment.
The first aspect is a search for axion-like particles using a variable
baseline, "light-shining-through-a-wall" technique. This search excludes the
particle interpretation of the PVLAS signal with high confidence. The second
aspect of the GammeV experiment is a search for chameleon particles, scalar
particles which may be responsible for the dark energy of the universe. This is
accomplished by looking for a characteristic afterglow signature from a
"particle-in-a-jar" experiment whereby chameleon particles become trapped in a
region with a high magnetic field and slowly decay into detectable photons.
This is the first use of this experimental technique to probe for these
particles. We place interesting limits on a limited range of general chameleon
models. These limits are complimentary to other experiments, such as torsion
pendulum experiments, which probe for forces that would result from new scalar
particles.


title: Soft Photon Radiation in Particle Decays in SHERPA

abstract:
  In this paper the Yennie-Frautschi-Suura approach is used to simulate real
and virtual QED corrections in particle decays. It makes use of the universal
structure of soft photon corrections to resum the leading logarithmic QED
corrections to all orders, and it allows a systematic correction of this
approximate result to exact fixed order results from perturbation theory. The
approach has been implemented as a Monte Carlo algorithm, which a posteriori
modifies decay matrix elements through the emission of varying numbers of
photons. The corresponding computer code is incorporated into the SHERPA event
generator framework.


title:
Wall Crossing of BPS States on the Conifold from Seiberg Duality and
  Pyramid Partitions

abstract:
  In this paper we study the relation between pyramid partitions with a general
empty room configuration (ERC) and the BPS states of D-branes on the resolved
conifold. We find that the generating function for pyramid partitions with a
length n ERC is exactly the same as the D6/D2/D0 BPS partition function on the
resolved conifold in particular Kaehler chambers. We define a new type of
pyramid partition with a finite ERC that counts the BPS degeneracies in certain
other chambers.
  The D6/D2/D0 partition functions in different chambers were obtained by
applying the wall crossing formula. On the other hand, the pyramid partitions
describe T^3 fixed points of the moduli space of a quiver quantum mechanics.
This quiver arises after we apply Seiberg dualities to the D6/D2/D0 system on
the conifold and choose a particular set of FI parameters. The arrow structure
of the dual quiver is confirmed by computation of the Ext group between the
sheaves. We show that the superpotential and the stability condition of the
dual quiver with this choice of the FI parameters give rise to the rules
specifying pyramid partitions with length n ERC.


title:
Analog of Astrophysical Magnetorotational Instability in a
  Couette-Taylor Flow of Polymer Fluids

abstract:
  We report experimental observation of an instability in a Couette-Taylor flow
of a polymer fluid in a thin gap between two coaxially rotating cylinders in a
regime where their angular velocity decreases with the radius while the
specific angular momentum increases with the radius. In the considered regime,
neither the inertial Rayleigh instability nor the purely elastic instability
are possible. We propose that the observed "elasto-rotational" instability is
an analog of the magnetorotational instability which plays a fundamental role
in astrophysical Keplerian accretion disks.


title: Photon Distribution Amplitude in approach with nonlocal condensates

abstract:
  We investigate magnetic susceptibility and the leading twist light-cone
distribution amplitude for the real photon in the framework of the nonlocal
condensate approach at LO accuracy of perturbative expansion.


title: L^p Bernstein estimates and approximation by spherical basis functions

abstract:
  The purpose of this paper is to establish L^p error estimates, a Bernstein
inequality, and inverse theorems for approximation by a space comprising
spherical basis functions located at scattered sites on the unit n-sphere. In
particular, the Bernstein inequality estimates L^p Bessel-potential Sobolev
norms of functions in this space in terms of the minimal separation and the L^p
norm of the function itself. An important step in its proof involves measuring
the L^p stability of functions in the approximating space in terms of the l^p
norm of the coefficients involved. As an application of the Bernstein
inequality, we derive inverse theorems for SBF approximation in the L^P norm.
Finally, we give a new characterization of Besov spaces on the n-sphere in
terms of spaces of SBFs.


title: Phantom without phantom or how the PT symmetry saves us from the Big Rip

abstract:
  We consider the PT symmetric flat Friedmann model of two scalar fields with
positive kinetic terms. While the potential of one ("normal") field is taken
real, that of the other field is complex. We study a complex classical solution
of the system of the two Klein-Gordon equations together with the Friedmann
equation. The solution for the normal field is real while the solution for the
second field is purely imaginary, realizing classically the "phantom" behavior.
The energy density and pressure are real and the corresponding geometry is
well-defined. The Lagrangian for the linear perturbations has the correct
potential signs for both the fields, so that the problem of stability does not
arise. The background dynamics is determined by an effective action including
two real fields one normal and one "phantom". Remarkably, the phantom phase in
the cosmological evolution is transient and the Big Rip never occurs. Our model
is contrasted to well-known quintom models, which also include one normal and
one phantom fields.


title:
Alternative evaluation of a ln tan integral arising in quantum field
  theory

abstract:
  A certain dilogarithmic integral I_7 turns up in a number of contexts
including Feynman diagram calculations, volumes of tetrahedra in hyperbolic
geometry, knot theory, and conjectured relations in analytic number theory. We
provide an alternative explicit evaluation of a parameterized family of
integrals containing this particular case. By invoking the Bloch-Wigner form of
the dilogarithm function, we produce an equivalent result, giving a third
evaluation of I_7. We also alternatively formulate some conjectures which we
pose in terms of values of the specific Clausen function Cl_2.


title: Demonstrative and non-demonstrative reasoning by analogy

abstract:
  The paper analizes a set of issues related to analogy and analogical
reasoning, namely: 1) The problem of analogy and its duplicity; 2) The role of
analogy in demonstrative reasoning; 3) The role of analogy in non-demonstrative
reasoning; 4) The limits of analogy; 5) The convergence, particularly in
multiple analogical reasoning, of these two apparently distinct aspects and its
methodological and philosophical consequences. The paper, using example from
number theory, argues for an heuristc conception of analogy.


title: Hylomorphic solitons in the nonlinear Klein-Gordon equation

abstract:
  Roughly speaking a solitary wave is a solution of a field equation whose
energy travels as a localised packet and which preserves this localisation in
time. A soliton is a solitary wave which exhibits some strong form of stability
so that it has a particle-like behaviour. In this paper we show a new mechanism
which might produce solitary waves and solitons for a large class of equations,
such as the nonlinear Klein-Gordon equation. We show that the existence of
these kind of solitons, that we have called \emph{hylomorphic} solitons,
depends on a suitable energy/charge ratio. We show a variational method that
allows to prove the existence of hylomorphic solitons and that turns out to be
very useful for numerical applications. Moreover we introduce some classes of
nonlinearities which admit hylomorphic solitons of different shapes and with
different relations between charge, energy and frequency.


title: Structural instability of Friedmann-Robertson-Walker cosmological models

abstract:
  Cosmological singularity and asymptotic behaviour of scale factor of
generalized cosmological models are analyzed in respect of their structural
stability. It is shown, that cosmological singularity is structurally unstable
for the majority of models with barotropic perfect fluid with strong energy
condition. Inclusion of Lambda-term extends the set of structurally stable
cosmological models.


title:
Magnetic and Superfluid Transitions in the d=1 Spin-1 Boson Hubbard
  Model

abstract:
  The interplay between magnetism and metal-insulator transitions is
fundamental to the rich physics of the single band fermion Hubbard model (FHM).
Recent progress in experiments on trapped ultra-cold atoms have made possible
the exploration of similar effects in the boson Hubbard model (BHM). This paper
reports Quantum Monte Carlo (QMC) simulations of the spin-1 BHM in the ground
state. In the case of antiferromagnetic interactions, which favor singlet
formation within the Mott insulator lobes, we present exact numerical evidence
that the superfluid-insulator phase transition is first (second) order
depending on whether the Mott lobe is even (odd). In the ferromagnetic case,
the transitions are all continuous. We obtain the phase diagram in the case of
attractive spin interactions and demonstrate the existence of the ferromagnetic
superfluid. We also compare the QMC phase diagram with a third order
perturbation calculation.


title: Geometric Scaling of $F_2$ and $F_2^c$ in data and QCD Parametrisations

abstract:
  The scaling properties at low $x$ of the proton DIS cross section and its
charm component are analyzed with the help of the quality factor method.
Scaling properties are tested both in the deep inelastic scattering data and in
the structure functions reconstructed from CTEQ, MRST and GRV parametrisations
of parton density functions. The results for DIS cross sections are fully
compatible between data and parametrisations. Even with larger error bars, the
charm component data favors the same geometric scaling properties as the ones
of inclusive DIS. This is not the case for all parametrisations of the charm
component.


title: On some modular representations of the Borel subgroup of GL_2(Q_p)

abstract:
  Colmez has given a recipe to associate a smooth modular representation
Omega(W) of the Borel subgroup of GL_2(Q_p) to a F_p^bar-representation W of
Gal(Qp^bar/Qp) by using Fontaine's theory of (phi,Gamma)-modules. We compute
Omega(W) explicitly and we prove that if W is irreducible and dim(W)=2, then
Omega(W) is the restriction to the Borel subgroup of GL_2(Q_p) of the
supersingular representation associated to W in Breuil's correspondence.


title:
Thermodynamics of itinerant magnets in a classical spin fluctuation
  model

abstract:
  Thermodynamics of itinerant magnets is studied using a classical model with
one parameter characterizing the degree of itinerancy. Monte Carlo simulations
for bcc and fcc lattices are compared with the mean-field approximation and
with the Onsager cavity field approximation extended to itinerant systems. The
qualitative features of thermodynamics are similar to the known results of the
functional integral method. It is found that magnetic short-range order is weak
and almost independent on the degree of itinerancy, and the mean-field
approximation describes the thermodynamics reasonably well. Ambiguity of the
phase space measure for classical models is emphasized. The Onsager cavity
field method is extended to itinerant systems, which involves the
renormalization of both the Weiss field and the on-site exchange interaction.
The predictions of this approximation are in excellent agreement with Monte
Carlo results.


title:
The mass-radius relationship from solar-type stars to terrestrial
  planets: a review

abstract:
  In this review, we summarize our present knowledge of the behaviour of the
mass-radius relationship from solar-type stars down to terrestrial planets,
across the regime of substellar objects, brown dwarfs and giant planets.
Particular attention is paid to the identification of the main physical
properties or mechanisms responsible for this behaviour. Indeed, understanding
the mechanical structure of an object provides valuable information about its
internal structure, composition and heat content as well as its formation
history. Although the general description of these properties is reasonably
well mastered, disagreement between theory and observation in certain cases
points to some missing physics in our present modelling of at least some of
these objects. The mass-radius relationship in the overlaping domain between
giant planets and low-mass brown dwarfs is shown to represent a powerful
diagnostic to distinguish between these two different populations and shows
once again that the present IAU distinction between these two populations at a
given mass has no valid foundation.


title:
Foliations by Stable Spheres with Constant Mean Curvature for Isolated
  Systems with General Asymptotics

abstract:
  We prove the existence and uniqueness of constant mean curvature foliations
for initial data sets which are asymptotically flat satisfying the
Regge-Teitelboim condition near infinity. It is known that the (Hamiltonian)
center of mass is well-defined for manifolds satisfying this condition. We also
show that the foliation is asymptotically concentric, and its geometric center
is the center of mass. The construction of the foliation generalizes the
results of Huisken-Yau, Ye, and Metzger, where strongly asymptotically flat
manifolds and their small perturbations were studied.


title:
Resolved debris disk emission around eta Tel: a young Solar System or
  ongoing planet formation?

abstract:
  60% of the A star members of the 12 Myr old beta Pictoris moving group (BPMG)
show significant excess emission in the mid-infrared, several million years
after the proto-planetary disk is thought to disperse. Theoretical models
suggest this peak may coincide with the formation of Pluto-sized planetesimals
in the disk, stirring smaller bodies into collisional destruction. Here we
present resolved mid-infrared imaging of the disk of eta Tel (A0V in the BPMG)
and consider its implications for the state of planet formation in this system.
eta Tel was observed at 11.7 and 18.3um using T-ReCS on Gemini South. The
resulting images were compared to simple disk models to constrain the radial
distribution of the emitting material. The emission observed at 18.3um is shown
to be significantly extended beyond the PSF along a position angle 8 degrees.
This is the first time dust emission has been resolved around eta Tel.
Modelling indicates that the extension arises from an edge-on disk of radius
0.5 arcsec (~24 AU). Combining the spatial constraints from the imaging with
those from the spectral energy distribution shows that >50% of the 18um
emission comes from an unresolved dust component at ~4 AU. The radial structure
of the eta Tel debris disk is reminiscent of the Solar System, suggesting that
this is a young Solar System analogue. For an age of 12Myr, both the radius and
dust level of the extended cooler component are consistent with self-stirring
models for a protoplanetary disk of 0.7 times minimum mass solar nebula. The
origin of the hot dust component may arise in an asteroid belt undergoing
collisional destruction, or in massive collisions in ongoing terrestrial planet
formation.


title: Spitzer/IRS Mapping of Local Luminous Infrared Galaxies

abstract:
  We present results of our program Spitzer/IRS Mapping of local Luminous
Infrared Galaxies (LIRGs). The maps cover the central 20"x20" or 30"x 30"
regions of the galaxies, and use all four IRS modules to cover the full 5-38
microns spectral range. We have built spectral maps of the main mid-IR emission
lines, continuum and PAH features, and extracted 1D spectra for regions of
interest in each galaxy. The final goal is to fully characterize the mid-IR
properties of local LIRGs as a first step to understanding their more distant
counterparts.


title: On notions of harmonicity

abstract:
  In this paper, we address the equivalence of the analytic and probabilistic
notions of harmonicity in the context of general symmetric Hunt processes on
locally compact separable metric spaces. Extensions to general symmetric right
processes on Lusin spaces including infinite dimensional spaces are mentioned
at the end of this paper.


title:
Power-Bandwidth Tradeoff in Multiuser Relay Channels with Opportunistic
  Scheduling

abstract:
  The goal of this paper is to understand the key merits of multihop relaying
techniques jointly in terms of their energy efficiency and spectral efficiency
advantages in the presence of multiuser diversity gains from opportunistic
(i.e., channel-aware) scheduling and identify the regimes and conditions in
which relay-assisted multiuser communication provides a clear advantage over
direct multiuser communication. For this purpose, we use Shannon-theoretic
tools to analyze the tradeoff between energy efficiency and spectral efficiency
(known as the power-bandwidth tradeoff) over a fading multiuser relay channel
with $K$ users in the asymptotic regime of large (but finite) number of users
(i.e., dense network). Benefiting from the extreme-value theoretic results of
\cite{Oyman_isit07}, we characterize the power-bandwidth tradeoff and the
associated energy and spectral efficiency measures of the bandwidth-limited
high signal-to-noise ratio (SNR) and power-limited low SNR regimes, and utilize
them in investigating the large system behavior of the multiuser relay channel
as a function of the number of users and physical channel SNRs. Our analysis
results in very accurate closed-form formulas in the large (but finite) $K$
regime that quantify energy and spectral efficiency performance, and provides
insights on the impact of multihop relaying and multiuser diversity techniques
on the power-bandwidth tradeoff.


title: Legendrian links, causality, and the Low conjecture

abstract:
  Let $(X^{m+1}, g)$ be a globally hyperbolic spacetime with Cauchy surface
diffeomorphic to an open subset of $\mathbb R^m$. The Legendrian Low conjecture
formulated by Nat\'ario and Tod says that two events $x,y\in\ss$ are causally
related if and only if the Legendrian link of spheres $\mathfrak S_x, \mathfrak
S_y$ whose points are light geodesics passing through $x$ and $y$ is
non-trivial in the contact manifold of all light geodesics in $X$. The Low
conjecture says that for $m=2$ the events $x,y$ are causally related if and
only if $\mathfrak S_x, \mathfrak S_y$ is non-trivial as a topological link. We
prove the Low and the Legendrian Low conjectures. We also show that similar
statements hold for any globally hyperbolic $(X^{m+1}, g)$ such that a cover of
its Cauchy surface is diffeomorphic to an open domain in $\mathbb R^m.$


title:
Third Order Effect of Rotation on Stellar Oscillations of a
  $\beta$-Cephei Star

abstract:
  Here the effect of rotation up to third order in the angular velocity of a
star on the p, f and g modes is investigated. To do this, the third-order
perturbation formalism presented by Soufi et al. (1998) and revised by Karami
(2008), was used. I quantify by numerical calculations the effect of rotation
on the oscillation frequencies of a uniformly rotating $\beta$-Cephei star with
12 $M_\odot$. For an equatorial velocity of 90 $\rm km s^{-1}$, it is found
that the second- and third-order corrections for $(l,m)=(5,-4)$, for instance,
are of order of 0.07% of the frequency for radial order $n=-3$ and reaches up
to 0.6% for $n=-20$.


title: Direct observation of the superconducting gap in phonon spectra

abstract:
  We show that the superconducting energy gap $\Delta$ can be directly observed
in phonon spectra, as predicted by recent theories. In addition, since each
phonon probes the gap on only a small part of the Fermi surface, the gap
anisotropy can be studied in detail. Our neutron scattering investigation of
the anisotropic conventional superconductor YNi$_2$B$_2$C demonstrates this new
application of phonon spectroscopy.


title:
Mid-infrared VISIR and Spitzer observations of the surroundings of the
  magnetar SGR 1806-20

abstract:
  We report mid-infrared observations of SGR 1806-20 and its environment - with
the highest spatial resolution in this domain to date - using ESO/VISIR in 2005
and 2006, and we retrieved Spitzer/IRAC-MIPS archival data of the same field.
  We aimed at studying the mid-infrared emission of the stars associated with
the same cluster as SGR 1806-20, to detect variations that could be due to the
high-energy activity of the magnetar through interaction with the dust. We also
aimed at studying the morphology of the cloud close to the centre of the
cluster.
  We performed broadband photometry of three stars - LBV 1806-20, a WC9 and an
O/B supergiant - on our VISIR images, as well as on the IRAC data. We then
built and fitted their broadband spectral energy distributions with a
combination of two absorbed black bodies, representing their stellar
components, as well as a possible mid-infrared excess, in order to derive their
physical parameters.
  We show that LBV 1806-20 and the WC9 star exhibit a mid-infrared excess,
likely because of the presence of circumstellar dust related to their winds. We
also show that only LBV 1806-20 had a variable flux over a period of two years,
variability which is due to its LBV nature rather than to a heating of the gas
and dust cloud by the high-energy emission of SGR 1806-20. Finally, differences
in the intrinsic absorptions of the three stars show an inhomogeneous structure
of the density of the gas and dust cloud in the massive star cluster.


title:
Intrinsic Quantum Noise in Faraday Rotation Measurements of a Single
  Electron Spin

abstract:
  Faraday rotation is one way to realize quantum non-demolition measurement of
electron spin in quantum dots. To describe Faraday rotation, semiclassical
models are typically used, based on quantized electron spin states and
classical electromagnetic fields. Such treatments neglect the entanglement
between electronic and photonic degrees of freedom that produce intrinsic
quantum noise, limiting the ultimate sensitivity of this technique. We present
a fully quantum-mechanical description of Faraday rotation, and quantify this
intrinsic noise. A method for measuring the purity of a given spin state is
suggested based on this analysis.


title: On unique extension of time changed reflecting Brownian motions

abstract:
  Let $D$ be an unbounded domain in $\RR^d$ with $d\geq 3$. We show that if $D$
contains an unbounded uniform domain, then the symmetric reflecting Brownian
motion (RBM) on $\overline D$ is transient. Next assume that RBM $X$ on
$\overline D$ is transient and let $Y$ be its time change by Revuz measure
${\bf 1}_D(x) m(x)dx$ for a strictly positive continuous integrable function
$m$ on $\overline D$. We further show that if there is some $r>0$ so that
$D\setminus \overline {B(0, r)}$ is an unbounded uniform domain, then $Y$
admits one and only one symmetric diffusion that genuinely extends it and
admits no killings. In other words, in this case $X$ (or equivalently, $Y$) has
a unique Martin boundary point at infinity.


title:
Measurement of small photodestruction rates of cold, charged
  biomolecules in an ion trap

abstract:
  In this work, we demonstrate measurements of photodestruction rates of
translationally cold, charged biomolecules. The long-term stable storage of the
molecular ions in an ion trap at ultra-high vacuum conditions allows
measurement of small rates and verification that rates are linear in
photodestruction laser intensity. Measurements were performed on singly
protonated molecules of the organic compound glycyrrhetinic acid (C30H46O4),
dissociated by a continuous-wave UV laser (266 nm) using different intensities.
The molecules were sympathetically cooled by simultaneously trapped
laser-cooled barium ions to translational temperatures of below 150 mK.
Destruction rates of less than 0.05 s^-1 and a cross section of (1.1 +/- 0.1) *
10^-17 cm^2 have been determined. An extension to tunable UV laser sources
would permit high-resolution dissociation spectroscopic studies on a wide
variety of cold complex molecules.


title: Reliability Bounds for Delay-Constrained Multi-hop Networks

abstract:
  We consider a linear multi-hop network composed of multi-state discrete-time
memoryless channels over each hop, with orthogonal time-sharing across hops
under a half-duplex relaying protocol. We analyze the probability of error and
associated reliability function \cite{Gallager68} over the multi-hop network;
with emphasis on random coding and sphere packing bounds, under the assumption
of point-to-point coding over each hop. In particular, we define the system
reliability function for the multi-hop network and derive lower and upper
bounds on this function to specify the reliability-optimal operating conditions
of the network under an end-to-end constraint on the total number of channel
uses. Moreover, we apply the reliability analysis to bound the expected
end-to-end latency of multi-hop communication under the support of an automatic
repeat request (ARQ) protocol. Considering an additive white Gaussian noise
(AWGN) channel model over each hop, we evaluate and compare these bounds to
draw insights on the role of multi-hopping toward enhancing the end-to-end
rate-reliability-delay tradeoff.


title: Ein gesuchter, dennoch bislang unbekannter elementarer Satz

abstract:
  If and only if each point of a set of the phase-space is in the topological
hull of a trajectory running through any other point of this set, we call this
set a quasiergodic set. But which are these so defined quasiergodic sets in the
case of a given continuous dynamical system, which has piecewise differentiable
trajectories in a finit-dimensional real phase-space, which is compact? Let its
trajectories define a field of normed tangents, which is continuous in almost
each point of the phase-space: Then the topological hulls of all trajectories
of the phase-space form a partition of it. Thus the elements of this partition
are the quasiergodic sets of the given continuous dynamical system. This is the
important but rather trivial statement of the elementary theorem 1.1, which we
present in this tractatus. We call this theorem elementary, because it is
limited to finit-dimensional real phase-spaces. We also find, that there is a
linear homogeneous partial differential equation of first order, describing the
invariants of the system, which allow us the construction of the quasiergodic
sets. Furthermore we show, that any quasiergodic set is a sensitive attractor,
if it is neither a closed trajectory or a fixed point.


title:
High-order 3D Voronoi tessellation for identifying Isolated galaxies,
  Pairs and Triplets

abstract:
  Geometric method based on the high-order 3D Voronoi tessellation is proposed
for identifying the single galaxies, pairs and triplets. This approach allows
to select small galaxy groups and isolated galaxies in different environment
and find the isolated systems. The volume-limited sample of galaxies from the
SDSS DR5 spectroscopic survey was used. We conclude that in such small groups
as pairs and triplets the segregation by luminosity is clearly observed:
galaxies in the isolated pairs and triplets are on average two times more
luminous than isolated galaxies. We consider the dark matter content in
different systems. The median values of mass-to-luminosity ratio are 12
M_sol/L_sol for the isolated pairs and 44 M_sol/L_sol for the isolated
triplets; 7 (8) M_sol/L_sol for the most compact pairs (triplets). We found
also that systems in the denser environment have greater rms velocity and
mass-to-luminosity ratio.


title: Matching coefficients for alpha_s and m_b to O(alpha_s^2) in the MSSM

abstract:
  We compute the exact two-loop matching coefficients for the strong coupling
constant alpha_s and the bottom-quark mass m_b within the Minimal
Supersymmetric Standard Model (MSSM), taking into account
  O(alpha_s^2) contributions from Supersymmetric Quantum Chromodynamics (SQCD).
We find that the explicit mass pattern of the supersymmetric particles has a
significant impact on the predictions of alpha_s and m_b at high energies.
Further on, the three-loop corrections exceed the uncertainty due to the
current experimental accuracy. In case of the the running bottom-quark mass,
they can reach in the large tan(beta) regime up to 30% of the tree-level value.


title:
Translational cooling and storage of protonated proteins in an ion trap
  at subkelvin temperatures

abstract:
  Gas-phase multiply charged proteins have been sympathetically cooled to
translational temperatures below 1 K by Coulomb interaction with laser-cooled
barium ions in a linear ion trap. In one case, an ensemble of 53 cytochrome c
molecules (mass ~ 12390 amu, charge +17 e) was cooled by ~ 160 laser-cooled
barium ions to less than 0.75 K. Storage times of more than 20 minutes have
been observed and could easily be extended to more than an hour. The technique
is applicable to a wide variety of complex molecules.


title: Magnetization of the QCD vacuum at large fields

abstract:
  The response of the QCD vacuum to very large static external magnetic fields
(q B >> Lambda_QCD^2) is studied. In this regime, the magnetization of the QCD
vacuum is naturally described via perturbative QCD. Combining pQCD and the
Schwinger proper time formalism, we calculate the magnetization of the QCD
vacuum due to a strong magnetic field at leading order (one-loop) to be
proportional to B log B. We show that the leading perturbative correction
(two-loop) vanishes.


title: On the effective theory of type IIA AdS_4 compactifications

abstract:
  This is a summary of arXiv:0806.3458, where the low energy effective theory
of type IIA AdS_4 N=1 flux compactifications on nilmanifolds and cosets has
been analyzed. We compute the superpotential, the K\"ahler potential and the
mass spectrum for the light moduli. For the nilmanifold examples we perform a
cross-check on the result for the mass spectrum by calculating it from a direct
Kaluza-Klein reduction.


title:
Random Walks and Anderson Localisation in a Three-Dimensional Class C
  Network Model

abstract:
  We study the disorder-induced localisation transition in a three-dimensional
network model that belongs to symmetry class C. The model represents
quasiparticle dynamics in a gapless spin-singlet superconductor without
time-reversal invariance. It is a special feature of network models with this
symmetry that the conductance and density of states can be expressed as
averages in a classical system of dense, interacting random walks. Using this
mapping, we present a more precise numerical study of critical behaviour at an
Anderson transition than has been possible previously in any context.


title:
Tycho Brahe's 1572 supernova as a standard type Ia explosion revealed
  from its light echo spectrum

abstract:
  Type Ia supernovae (SNe Ia) are thermonuclear explosions of white dwarf stars
in close binary systems. They play an important role as cosmological distance
indicators and have led to the discovery of the accelerated expansion of the
Universe. Among the most important unsolved questions are how the explosion
actually proceeds and whether accretion occurs from a companion or via the
merging of two white dwarfs. Tycho Brahe's supernova of 1572 (SN 1572) is
thought to be one of the best candidates for a SN Ia in the Milky Way. The
proximity of the SN 1572 remnant has allowed detailed studies, such as the
possible identification of the binary companion, and provides a unique
opportunity to test theories of the explosion mechanism and the nature of the
progenitor. The determination of the yet unknown exact spectroscopic type of SN
1572 is crucial to relate these results to the diverse population of SNe Ia.
Here we report an optical spectrum of Tycho Brahe's supernova near maximum
brightness, obtained from a scattered-light echo more than four centuries after
the direct light of the explosion swept past Earth. We find that SN 1572
belongs to the majority class of normal SNe Ia. The presence of a strong Ca II
IR feature at velocities exceeding 20,000 km/s, which is similar to the
previously observed polarized features in other SNe Ia, suggests asphericity in
SN 1572.


title:
Software Holography: Interferometric Data Analysis for the Challenges of
  Next Generation Observatories

abstract:
  Next generation radio observatories such as the MWA, LWA, LOFAR, CARMA and
SKA provide a number of challenges for interferometric data analysis. These
challenges include heterogeneous arrays, direction-dependent instrumental gain,
and refractive and scintillating atmospheric conditions. From the analysis
perspective, this means that calibration solutions can not be described using a
single complex gain per antenna. In this paper we use the optimal map-making
formalism developed for CMB analyses to extend traditional interferometric
radio analysis techniques--removing the assumption of a single complex gain per
antenna and allowing more complete descriptions of the instrumental and
atmospheric conditions. Due to the similarity with holographic mapping of radio
antenna surfaces, we call this extended analysis approach software holography.
The resulting analysis algorithms are computationally efficient, unbiased, and
optimally sensitive. We show how software holography can be used to solve some
of the challenges of next generation observations, and how more familiar
analysis techniques can be derived as limiting cases.


title: C3, Semi-Clifford and Generalized Semi-Clifford Operations

abstract:
  Fault-tolerant quantum computation is a basic problem in quantum computation,
and teleportation is one of the main techniques in this theory. Using
teleportation on stabilizer codes, the most well-known quantum codes, Pauli
gates and Clifford operators can be applied fault-tolerantly. Indeed, this
technique can be generalized for an extended set of gates, the so called
${\mathcal{C}}_k$ hierarchy gates, introduced by Gottesman and Chuang (Nature,
402, 390-392). ${\mathcal{C}}_k$ gates are a generalization of Clifford
operators, but our knowledge of these sets is not as rich as our knowledge of
Clifford gates. Zeng et al. in (Phys. Rev. A 77, 042313) raise the question of
the relation between ${\mathcal{C}}_k$ hierarchy and the set of semi-Clifford
and generalized semi-Clifford operators. They conjecture that any
${\mathcal{C}}_k$ gate is a generalized semi-Clifford operator. In this paper,
we prove this conjecture for $k=3$. Using the techniques that we develop, we
obtain more insight on how to characterize ${\mathcal{C}}_3$ gates. Indeed, the
more we understand ${\mathcal{C}}_3$, the more intuition we have on
${\mathcal{C}}_k$, $k\geq 4$, and then we have a way of attacking the
conjecture for larger $k$.


title: NP vs QMA_log(2)

abstract:
  Although it is believed unlikely that $\NP$-hard problems admit efficient
quantum algorithms, it has been shown that a quantum verifier can solve
$\NP$-complete problems given a "short" quantum proof; more precisely,
$\NP\subseteq \QMA_{\log}(2)$ where $\QMA_{\log}(2)$ denotes the class of
quantum Merlin-Arthur games in which there are two unentangled provers who send
two logarithmic size quantum witnesses to the verifier. The inclusion
$\NP\subseteq \QMA_{\log}(2)$ has been proved by Blier and Tapp by stating a
quantum Merlin-Arthur protocol for 3-coloring with perfect completeness and gap
$\frac{1}{24n^6}$. Moreover, Aaronson {\it et al.} have shown the above
inclusion with a constant gap by considering $\widetilde{O}(\sqrt{n})$
witnesses of logarithmic size. However, we still do not know if
$\QMA_{\log}(2)$ with a constant gap contains $\NP$. In this paper, we show
that 3-SAT admits a $\QMA_{\log}(2)$ protocol with the gap
$\frac{1}{n^{3+\epsilon}}$ for every constant $\epsilon>0$.


title: The Monitor project: Rotation periods of low-mass stars in M50

abstract:
  We report on the results of a time-series photometric survey of M50 (NGC
2323), a ~130 Myr open cluster, carried out using the CTIO 4m Blanco telescope
and Mosaic-II detector as part of the Monitor project. Rotation periods were
derived for 812 candidate cluster members over the mass range 0.2 <~ M/Msol <~
1.1. The rotation period distributions show a clear mass-dependent morphology,
statistically indistinguishable from those in NGC 2516 and M35 taken from the
literature. Due to the availability of data from three observing runs separated
by ~10 and 1 month timescales, we are able to demonstrate clear evidence for
evolution of the photometric amplitudes, and hence spot patterns, over the 10
month gap, although we are not able to constrain the timescales for these
effects in detail due to limitations imposed by the large gaps in our sampling,
preventing use of the phase information.


title:
The rheology of hard sphere suspensions at arbitrary volume fractions:
  An improved differential viscosity model

abstract:
  We propose a simple and general model accounting for the dependence of the
viscosity of a hard sphere suspension at arbitrary volume fractions. The model
constitutes a continuum-medium description based on a recursive-differential
method that assumes a hierarchy of relaxation times. Geometrical information of
the system is introduced through an effective volume fraction that approaches
the usual filling fraction at low concentrations and becomes one at maximum
packing. The agreement of our expression for the viscosity with experiments at
low- and high-shear rates and in the high-frequency limit is remarkable for all
volume fractions.


title: Longitudinal Structure Function Measurements from HERA

abstract:
  Measurements of the longitudinal structure function FL at the ep collider
HERA are presented. They are derived from inclusive deep inelastic neutral
current e+p scattering cross section measurements based on data collected in
2007 with the H1 and ZEUS detectors at a positron beam energy of 27.5 GeV and
proton beam energies of 920, 575 and 460 GeV. Employing the energy dependence
of the cross sections, FL(x,Q2) is measured in the range of negative
four-momentum transfer squared from 12 to 800 GeV2 and low Bjorken-x from
0.00028 to 0.0353. The measured longitudinal structure function is compared
with higher order QCD predictions.


title: Generalizations of the Goulden-Jackson Cluster Method

abstract:
  We give several modifications of the Goulden-Jackson Cluster method for
finding generating functions for words avoiding a given set of forbidden words.
Our modifications include functions which can take into account various
'weights' on words, including single letter probability distributions, double
letter (i.e. pairwise) probability distributions, and triple letter probability
distributions. We also describe an alternative, recursive approach to finding
such generating functions. We describe Maple implementations of the various
modifications. The accompanying Maple package is available at the website for
this paper.


title: Field-induced Gap and Quantized Charge Pumping in Nano-helix

abstract:
  We propose several novel physical phenomena based on nano-scale helical
wires. Applying a static electric field transverse to the helical wire induces
a metal to insulator transition, with the band gap determined by the applied
voltage. Similar idea can be applied to "geometrically" constructing
one-dimensional systems with arbitrary external potential. With a quadrupolar
electrode configuration, the electric field could rotate in the transverse
plane, leading to a quantized dc charge current proportional to the frequency
of the rotation. Such a device could be used as a new standard for the high
precession measurement of the electric current. The inverse effect implies that
passing an electric current through a helical wire in the presence of a
transverse static electric field can lead to a mechanical rotation of the
helix. This effect can be used to construct nano-scale electro-mechanical
motors. Finally, our methodology also enables new ways of controlling and
measuring the electronic properties of helical biological molecules such as the
DNA.


title:
Transient Analysis of Warm Electron Injection Programming of Double Gate
  SONOS Memories by means of Full Band Monte Carlo Simulation

abstract:
  In this paper we investigate "Warm Electron Injection" as a mechanism for NOR
programming of double-gate SONOS memories through 2D full band Monte Carlo
simulations. Warm electron injection is characterized by an applied VDS smaller
than 3.15 V, so that electrons cannot easily accumulate a kinetic energy larger
than the height of the Si/SiO2 barrier. We perform a time-dependent simulation
of the program operation where the local gate current density is computed with
a continuum-based method and is adiabatically separated from the 2D full Monte
Carlo simulation used for obtaining the electron distribution in the phase
space. In this way we are able to compute the time evolution of the charge
stored in the nitride and of the threshold voltages corresponding to forward
and reverse bias. We show that warm electron injection is a viable option for
NOR programming in order to reduce power supply, preserve reliability and CMOS
logic level compatibility. In addition, it provides a well localized charge,
offering interesting perspectives for multi-level and dual bit operation, even
in devices with negligible short channel effects.


title: Ensemble Control of Finite Dimensional Time-Varying Linear Systems

abstract:
  In this article, we investigate the problem of simultaneously steering an
uncountable family of finite dimensional time-varying linear systems. We call
this class of control problems Ensemble Control, a notion coming from the study
of spin dynamics in Nuclear Magnetic Resonance (NMR) spectroscopy and imaging
(MRI). This subject involves controlling a continuum of parameterized dynamical
systems with the same open-loop control input. From a viewpoint of mathematical
control theory, this class of problems is challenging because it requires
steering a continuum of dynamical systems between points of interest in an
infinite dimensional state space by use of the same control function. The
existence of such a control raises fundamental questions of ensemble
controllability. We derive the necessary and sufficient controllability
conditions and an accompanying analytical optimal control law for ensemble
control of time-varying linear systems. We show that ensemble controllability
is in connection with singular values of the operator characterizing the system
dynamics. In addition, we study the problem of optimal ensemble control of
harmonic oscillators to demonstrate our main results. We show that the optimal
solutions are pertinent to the study of time-frequency limited signals and
prolate spheroidal wave functions. A systematic study of ensemble control
systems has immediate applications to systems with parameter uncertainties as
well as to broad areas of quantum control systems as arising in coherent
spectroscopy and quantum information processing. The new mathematical
structures appearing in such problems are an excellent motivation for new
developments in control theory.


title: A non-negative expansion for small Jensen-Shannon Divergences

abstract:
  In this report, we derive a non-negative series expansion for the
Jensen-Shannon divergence (JSD) between two probability distributions. This
series expansion is shown to be useful for numerical calculations of the JSD,
when the probability distributions are nearly equal, and for which,
consequently, small numerical errors dominate evaluation.