title: Secure Transmission with Multiple Antennas: The MISOME Wiretap Channel

abstract:
  The role of multiple antennas for secure communication is investigated within
the framework of Wyner's wiretap channel. We characterize the secrecy capacity
in terms of generalized eigenvalues when the sender and eavesdropper have
multiple antennas, the intended receiver has a single antenna, and the channel
matrices are fixed and known to all the terminals, and show that a beamforming
strategy is capacity-achieving. In addition, we show that in the high
signal-to-noise (SNR) ratio regime the penalty for not knowing eavesdropper's
channel is small--a simple ``secure space-time code'' that can be thought of as
masked beamforming and radiates power isotropically attains near-optimal
performance. In the limit of large number of antennas, we obtain a
realization-independent characterization of the secrecy capacity as a function
of the number $\beta$: the number of eavesdropper antennas per sender antenna.
We show that the eavesdropper is comparatively ineffective when $\beta<1$, but
that for $\beta\ge2$ the eavesdropper can drive the secrecy capacity to zero,
thereby blocking secure communication to the intended receiver. Extensions to
ergodic fading channels are also provided.


title: RMS Radio Source Contributions to the Microwave Sky

abstract:
  Cross-correlations of the WMAP full sky K, Ka, Q, V, and W band maps with the
1.4 GHz NVSS source count map and the HEAO I A2 2-10 keV full sky X-ray flux
map are used to constrain rms fluctuations due to unresolved microwave sources
in the WMAP frequency range. In the Q band (40.7 GHz), a lower limit, taking
account of only those fluctuations correlated with the 1.4 GHz radio source
counts and X-ray flux, corresponds to an rms Rayleigh-Jeans temperature of ~ 2
microKelvin for a solid angle of one square degree. The correlated fluctuations
at the other bands are consistent with a beta = -2.1 +- 0.4 frequency spectrum.
Using the rms fluctuations of the X-ray flux and radio source counts, and the
cross-correlation of these two quantities as a guide, the above lower limit
leads to a plausible estimate of ~ 5 microKelvin for Q-band rms fluctuations in
one square degree. This value is similar to that implied by the excess, small
angular scale fluctuations observed in the Q band by WMAP, and is consistent
with estimates made by extrapolating low-frquency source counts.


title: Quantum Structures for Lagrangian Submanifolds

abstract:
  We discuss various algebraic quantum structures associated to monotone
Lagrangian submanifolds and we present a number of applications, computations
and examples.


title: $Z^+(4430)$ as a resonance in the $D_1(D_1^\prime)D^*$ channel

abstract:
  We study the possibility that the $Z^+(4430)$ state observed by Belle is a
$D_1D^*$ (or $D_1'D^*$) resonance in S-wave. Focusing on its decays, We find
that the open-charm decay into $D^*D^*\pi$ is dominant. Furthermore, we use the
re-scattering mechanism to study its hidden-charm decays and find that the
re-scattering effects are significant in $D_1D^*$ channel but not in $D_1'D^*$
channel. For the $J^P=1^-$ candidate, with chosen parameters, we can get
$\Gamma(Z^+\to\psi'\pi^+)/\Gamma(Z^+\to J/\psi\pi^+)\thickapprox 5.3$, which
tends to account for why the $Z^+(4430)$ is difficult to be found in
$J/\psi\pi^+$. However, the $0^-$ candidate can not be ruled out by our
calculations.


title: Riemann zeta function and quantum chaos

abstract:
  A brief review of recent developments in the theory of the Riemann zeta
function inspired by ideas and methods of quantum chaos is given.


title:
The First Direct Distance and Luminosity Determination for a
  Self-Luminous Giant Exoplanet: The Trigonometric Parallax to
  2MASS1207334-393254Ab

abstract:
  We present the first trigonometric parallax and distance for a young
planetary mass object. A likely TW Hya cluster member, 2MASSW J1207334-393254Ab
(hereafter 2M1207Ab) is an M8 brown dwarf with a mid to late L type planetary
mass companion. Recent observations of spectral variability have uncovered
clear signs of disk accretion and outflow, constraining the age of the system
to <10 Myr. Because of its late spectral type and the clearly youthful nature
of the system, 2M1207b is very likely a planetary mass object. We have measured
the first accurate distance and luminosity for a self-luminous planetary mass
object. Our parallax measurements are accurate to <2 mas (1sigma) for 2M1207Ab.
With 11 total epochs of data taken from January 2006 through April 2 007 (475
images for 2M1207Ab), we determine a distance of 58.8+-7.0 pc (17.0{+2.3}{-1.8}
mas, 1.28sigma) to 2M1207Ab and a calculated luminosity of 0.68-2.2x10^-5 Lsun
for 2M1207b. Hence 2M1207Ab is a clear member of the TW Hya cluster in terms of
its distance, proper motions, and youthful nature. However, as previously noted
by Mohanty and co-workers, 2M1207b's luminosity appears low compared to its
temperature according to evolutionary models.


title: Searches for Mixing and CP Violation in the D0-D0bar System

abstract:
  We review searches for mixing and CP violation in the D0-D0bar system and
discuss the first evidence for mixing recently obtained by the Belle and BABAR
collaborations. We also present world average values for the mixing parameters
x=Delta m/Gamma and y=Delta Gamma/(2 Gamma) as calculated by the Heavy Flavors
Averaging Group.


title: Effects of Dust Geometry in Lyman Alpha Galaxies at z = 4.4

abstract:
  Equivalent widths (EWs) observed in high-redshift Lyman alpha galaxies could
be stronger than the EW intrinsic to the stellar population if dust is present
residing in clumps in the inter-stellar medium (ISM). In this scenario,
continuum photons could be extinguished while the Lyman alpha photons would be
resonantly scattered by the clumps, eventually escaping the galaxy. We
investigate this radiative transfer scenario with a new sample of six Lyman
alpha galaxy candidates in the GOODS CDF-S, selected at z = 4.4 with
ground-based narrow-band imaging obtained at CTIO. Grism spectra from the HST
PEARS survey confirm that three objects are at z = 4.4, and that another object
contains an active galactic nuclei (AGN). If we assume the other five (non-AGN)
objects are at z = 4.4, they have rest-frame EWs from 47 -- 190 A. We present
results of stellar population studies of these objects, constraining their
rest-frame UV with HST and their rest-frame optical with Spitzer. Out of the
four objects which we analyzed, three objects were best-fit to contain stellar
populations with ages on the order of 1 Myr and stellar masses from 3 - 10 x
10^8 solar masses, with dust in the amount of A_1200 = 0.9 - 1.8 residing in a
quasi-homogeneous distribution. However, one object (with a rest EW ~ 150 A)
was best fit by an 800 Myr, 6.6 x 10^9 solar mass stellar population with a
smaller amount of dust (A_1200 = 0.4) attenuating the continuum only. In this
object, the EW was enhanced ~ 50% due to this dust. This suggests that large EW
Lyman alpha galaxies are a diverse population. Preferential extinction of the
continuum in a clumpy ISM deserves further investigation as a possible cause of
the overabundance of large-EW objects that have been seen in narrow-band
surveys in recent years.


title:
Suzaku Observations of the North Polar Spur: Evidence for Nitrogen
  Enhancement

abstract:
  We present observations of the North Polar Spur (NPS) using the X-ray Imaging
Spectrometer (XIS) aboard the Suzaku X-ray satellite. The NPS is a large region
of enhanced soft X-ray and radio emission projected above the plane of the
Galaxy, likely produced by a series of supernovae and stellar winds from the
nearby Sco-Cen OB association. The exceptional sensitivity and spectral
resolution of the XIS below 1 keV allow unprecedented probing of low-energy
spectral lines, including CVI (0.37 keV) and NVII (0.50 keV), and we have
detected highly-ionized nitrogen toward the NPS for the first time. For this
single pointing toward the brightest 3/4 keV emission (l = 26.8 deg, b = +22.0
deg), the best-fit NPS emission model implies a hot (kT ~ 0.3 keV), collisional
ionization equilibrium (CIE) plasma with depleted C, O, Ne, Mg, and Fe
abundances of less than 0.5 solar, but an enhanced N abundance, with N/O = 4.0
+0.4,-0.5 times solar. The temperature and total thermal energy of the gas
suggest heating by one or more supernovae, while the enhanced nitrogen
abundance is best explained by enrichment from stellar material that has been
processed by the CNO cycle. Due to the time required to develop AGB stars, we
conclude that this N/O enhancement cannot be caused by the Sco-Cen OB
association, but may result from a previous enrichment episode in the solar
neighborhood.


title: Opacity Build-up in Impulsive Relativistic Sources

abstract:
  Opacity effects in relativistic sources of high-energy gamma-rays, such as
gamma-ray bursts (GRBs) or Blazars, can probe the Lorentz factor of the outflow
and the distance of the emission site from the source, and thus help constrain
the composition of the outflow (protons, pairs, magnetic field) and the
emission mechanism. Most previous works consider the opacity in steady state.
Here we study time dependent effects of the opacity to pair production
($\gamma\gamma \to e^+e^-$) in impulsive relativistic sources. We present a
simple, yet rich, semi-analytic model for the time and energy dependence of the
optical depth, $\tau$, where an ultra-relativistic thin spherical shell emits
isotropically in its own rest frame over a finite range of radii, $R_0 < R <
R_0 + \Delta R$. This is very relevant for GRB internal shocks. We find that in
an impulsive source ($\Delta R <~ R_0$), while the instantaneous spectrum has
an exponential cutoff above the photon energy $\epsilon_1(T)$ where $\tau = 1$,
the time integrated spectrum has a power-law high-energy tail above a photon
energy $\epsilon_{1*} \sim \epsilon_1(\Delta T)$ where $\Delta T$ is the
duration of the emission episode. Furthermore, photons with $\epsilon >
\epsilon_{1*}$ will arrive mainly near the onset of the spike or flare from to
the short emission episode, as in impulsive sources it takes time to build-up
the (target) photon field, and thus $\tau(\epsilon)$ initially increases with
time and $\epsilon_1(T)$ decreases with time, so that photons of energy
$\epsilon > \epsilon_{1*}$ are able to escape the source mainly very early on
while $\epsilon_1(T) > \epsilon$. As the source approaches a quasi-steady state
($\Delta R >> R_0$), the time integrated spectrum develops an exponential
cutoff, while the power-law tail becomes increasingly suppressed.


title:
In-vivo measurement of the human soft tissues constitutive laws.
  Applications to Computer Aided Surgery

abstract:
  In the 80's, biomechanicians were asked to work on Computer Aided Surgery
applications since orthopaedic surgeons were looking for numerical tools able
to predict risks of fractures. More recently, biomechanicians started to
address soft tissues arguing that most of the human body is made of such
tissues that can move as well as deform during surgical gestures [1]. An
intra-operative use of a continuous Finite Element (FE) Model of a given tissue
mainly faces two problems: (1) the numerical simulations have to be
"interactive", i.e. sufficiently fast to provide results during surgery (which
can be a strong issue in the context of hyperelastic models for example) and
(2) during the intervention, the surgeon needs a device that can be used to
provide to the model an estimation of the patient-specific constitutive
behaviour of the soft tissues. This work proposes an answer to the second
point, with the design of a new aspiration device aiming at characterizing the
in vivo constitutive laws of human soft tissues. The device was defined in
order to permit sterilization as well an easy intra-operative use.


title:
Implicitization of Bihomogeneous Parametrizations of Algebraic Surfaces
  via Linear Syzygies

abstract:
  We show that the implicit equation of a surface in 3-dimensional projective
space parametrized by bi-homogeneous polynomials of bi-degree (d,d), for a
given positive integer d, can be represented and computed from the linear
syzygies of its parametrization if the base points are isolated and form
locally a complete intersection.


title: TASI Lectures on the Cosmological Constant

abstract:
  The energy density of the vacuum, Lambda, is at least 60 orders of magnitude
smaller than several known contributions to it. Approaches to this problem are
tightly constrained by data ranging from elementary observations to precision
experiments. Absent overwhelming evidence to the contrary, dark energy can only
be interpreted as vacuum energy, so the venerable assumption that Lambda=0
conflicts with observation. The possibility remains that Lambda is
fundamentally variable, though constant over large spacetime regions. This can
explain the observed value, but only in a theory satisfying a number of
restrictive kinematic and dynamical conditions. String theory offers a concrete
realization through its landscape of metastable vacua.


title: Heavy quark diffusion in perturbative QCD at next-to-leading order

abstract:
  We compute the momentum diffusion coefficient of a nonrelativistic heavy
quark in a hot QCD plasma, to next-to-leading order in the weak coupling
expansion. Corrections arise at O(g); physically they represent interference
between overlapping scatterings, as well as soft, electric scale ($p\sim gT$)
gauge field physics, which we treat using the hard thermal loop (HTL) effective
theory. In 3-color, 3-flavor QCD, the momentum diffusion constant of a
fundamental representation heavy quark at NLO is $\kappa = \frac{16\pi}{3}
\alpha_s^2 T^3 (\ln \frac{1}{g} + 0.07428 + 1.8869 g)$. The convergence of the
weak coupling expansion is poor.


title: WHIZARD: Simulating Multi-Particle Processes at LHC and ILC

abstract:
  We describe the universal Monte-Carlo event generator WHIZARD.
  The program automatically computes complete tree-level matrix elements,
integrates them over phase space, evaluates distributions of observables, and
generates unweighted event samples that can be used directly in detector
simulation. There is no principal limit on the process complexity; using
current hardware, the program has successfully been applied to hard scattering
processes with up to eight particles in the final state. Matrix elements are
computed as helicity amplitudes, so spin and color correlations are retained.
The Standard Model, the MSSM, and many alternative models such as Little Higgs,
anomalous couplings, or effects of extra dimensions or noncommutative SM
extensions have been implemented. Using standard interfaces to PDF,
beamstrahlung, parton shower and hadronization programs, WHIZARD generates
complete physical events and covers physics at hadron, lepton, and photon
colliders.


title: Algebraic G-functions associated to matrices over a group-ring

abstract:
  Given a square matrix with elements in the group-ring of a group, one can
consider the sequence formed by the trace (in the sense of the group-ring) of
its powers. We prove that the corresponding generating series is an algebraic
$G$-function (in the sense of Siegel) when the group is free of finite rank.
Consequently, it follows that the norm of such elements is an exactly
computable algebraic number, and their Green function is algebraic. Our proof
uses the notion of rational and algebraic power series in non-commuting
variables and is an easy application of a theorem of Haiman. Haiman's theorem
uses results of linguistics regarding regular and context-free language. On the
other hand, when the group is free abelian of finite rank, then the
corresponding generating series is a $G$-function. We ask whether the latter
holds for general hyperbolic groups. This version has an expanded introduction
following suggestions from Lehner, Voiculescu and others.


title: Minimal Distortion Bending and Morphing of Compact Manifolds

abstract:
  Let $M$ and $N$ be compact smooth oriented Riemannian $n$-manifolds without
boundary embedded in $\mathbb{R}^{n+1}$. Several problems about minimal
distortion bending and morphing of $M$ to $N$ are posed. Cost functionals that
measure distortion due to stretching or bending produced by a diffeomorphism
$h:M \to N$ are defined, and new results on the existence of minima of these
cost functionals are presented. In addition, the definition of a morph between
two manifolds $M$ and $N$ is given, and the theory of minimal distortion
morphing of compact manifolds is reviewed.


title: Anticipating a New Golden Age

abstract:
  The standard model of fundamental interactions is remarkably successful, but
it leaves an unfinished agenda. Several major questions seem ripe for
exploration in the near future. I anticipate that the coming decade will be a
Golden Age of discovery in fundamental physics.


title:
Restricted quantum-classical correspondence and counting statistics for
  a coherent transition

abstract:
  The conventional probabilistic point of view implies that if a particle has a
probability $p$ to make a transition from one site to another site, then the
average transport should be $<Q>=p}$ with a variance $Var(Q)=(1-p)p$. In the
quantum mechanical context this observation becomes a non-trivial manifestation
of restricted quantum-classical correspondence. We demonstrate this observation
by considering the full counting statistics which is associated with a two
level coherent transition in the context of a continuous quantum measurement
process. In particular we test the possibility of getting a valid result for
$Var(Q)$ within the framework of the adiabatic picture, analyzing the simplest
non-trivial example of a Landau-Zener crossing.


title:
Ambipolar Diffusion in Molecular Cloud Cores and the Gravomagneto
  Catastrophe

abstract:
  This paper re-examines the problem of ambipolar diffusion as a mechanism for
the production and runaway evolution of centrally condensed molecular cloud
cores, a process that has been termed the gravomagneto catastrophe. Our
calculation applies in the geometric limit of a highly flattened core and
allows for a semi-analytic treatment of the full problem, although physical
fixes are required to resolve a poor representation of the central region. A
noteworthy feature of the overall formulation is that the solutions for the
ambipolar diffusion portion of the evolution for negative times ($t < 0$) match
smoothly onto the collapse solutions for positive times ($t > 0$). The
treatment shows that the resulting cores display non-zero, but
sub-magnetosonic, inward velocities at the end of the diffusion epoch, in
agreement with current observations. Another important result is the derivation
of an analytic relationship between the dimensionless mass to flux ratio
$\lambda_0\equiv f_0^{-1}$ of the central regions produced by runaway core
condensation and the dimensionless measure of the rate of ambipolar diffusion
$\epsilon$. In conjunction with previous work showing that ambipolar diffusion
takes place more quickly in the presence of turbulent fluctuations, i.e., that
the effective value of $\epsilon$ can be enhanced by turbulence, the resultant
theory provides a viable working hypothesis for the formation of isolated
molecular-cloud cores and their subsequent collapse to form stars and planetary
systems.


title: Thermodynamic modeling of the Hf-Si-O system

abstract:
  The Hf-O system has been modeled by combining existing experimental data and
first-principles calculations results through the CALPHAD approach. Special
quasirandom structures of $\alpha$ and $\beta$ hafnium were generated to
calculate the mixing behavior of oxygen and vacancies. For the total energy of
oxygen, vibrational, rotational and translational degrees of freedom were
considered. The Hf-O system was combined with previously modeled Hf-Si and Si-O
systems, and the ternary compound in the Hf-Si-O system, HfSiO$_4$ has been
introduced to calculate the stability diagrams pertinent to the thin film
processing.


title: A dynamical mean-field theory study of Nagaoka ferromagnetism

abstract:
  We revisit Nagaoka ferromagnetism in the U=oo Hubbard model within the
dynamical mean-field theory (DMFT) using the recently developed continuous time
quantum Monte Carlo method as the impurity solver. The stability of Nagaoka
ferromagnetism is studied as a function of the temperature, the doping level,
and the next-nearest-neighbor lattice hopping t'. We found that the nature of
the phase transition as well as the stability of the ferromagnetic state is
very sensitive to the t' hopping. Negative t'=-0.1t stabilizes ferromagnetism
up to higher doping levels. The paramagnetic state is reached through a first
order phase transition. Alternatively, a second order phase transition is
observed at t'=0. Very near half-filling, the coherence temperature T_{coh} of
the paramagnetic metal becomes very low and ferromagnetism evolves out of an
incoherent metal rather than conventional Fermi liquid. We use the DMFT results
to benchmark slave-boson method which might be useful in more complicated
geometries.


title: Light Pseudoscalars in Little Higgs Models at the ILC

abstract:
  We discuss the properties of light pseudoscalar particles, the so-called
pseudoaxions, within Little Higgs models, focusing on their phenomenology at
the ILC. We especially discuss a method of how to distinguish between the two
basic classes of Little Higgs models, the product and simple group models, by a
specific production channel and decay mode. These are strictly forbidden in the
product group models.


title: Gaussianity of LISA's confusion backgrounds

abstract:
  Data analysis for the proposed Laser Interferometer Space Antenna (LISA) will
be complicated by the huge number of sources in the LISA band. Throughout much
of the band, galactic white dwarf binaries (GWDBs) are sufficiently dense in
frequency space that it will be impossible to resolve most of them, and
"confusion noise" from the unresolved Galactic binaries will dominate over
instrumental noise in determining LISA's sensitivity to other sources in that
band. Confusion noise from unresolved extreme-mass-ratio inspirals (EMRIs)
could also contribute significantly to LISA's total noise curve. To date,
estimates of the effect of LISA's confusion noise on matched-filter searches
and their detection thresholds have generally approximated the noise as
Gaussian, based on the Central Limit Theorem. However in matched-filter
searches, the appropriate detection threshold for a given class of signals may
be located rather far out on the tail of the signal-to-noise probability
distribution, where a priori it is unclear whether the Gaussian approximation
is reliable. Using the Edgeworth expansion and the theory of large deviations,
we investigate the probability distribution of the usual matched-filter
detection statistic, far out on the tail of the distribution. We apply these
tools to four somewhat idealized versions of specific LISA searches.


title: On the torsion of Drinfeld modules of rank two

abstract:
  We study rational points and torsion points on Drinfeld modular curves
defined over rational function fields. As a consequence we derive a conjecture
of Schweizer describing completely the torsion of Drinfeld modules of rank two
over $\Bbb F_2(T)$ implying Poonen's uniform boundedness conjecture in this
particular case.


title:
Hurwitz-Hodge Integrals, the E6 and D4 root systems, and the Crepant
  Resolution Conjecture

abstract:
  Let G be the group A_4 or Z_2xZ_2. We compute the integral of \lambda_g on
the Hurwitz locus H_G\subset M_g of curves admitting a degree 4 cover of P^1
having monodromy group G. We compute the generating functions for these
integrals and write them as a trigonometric expression summed over the positive
roots of the E_6 and D_4 root systems respectively. As an application, we prove
the Crepant Resolution Conjecture for the orbifolds [C^3/A_4] and
[C^3/(Z_2xZ_2)].


title:
Cyclic motion and inversion of surface flow direction in a dense polymer
  brush under shear

abstract:
  Using molecular simulations, we study the properties of a polymer brush in
contact with an explicit solvent under Couette and Poiseuille flow. The solvent
is comprised of chemically identical chains. We present evidence that
individual, unentangled chains in the dense brush exhibit cyclic, tumbling
motion and non-Gaussian fluctuations of the molecular orientations similar to
the behaviour of isolated tethered chains in shear flow. The collective
molecular motion gives rise to an inversion of hydrodynamic flow direction in
the vicinity of the brush-coated surface. Utilising Couette and Poiseuille
flow, we investigate to what extend the effect of a brush-coated surface can be
described by a Navier slip condition.


title: Radio and Infrared observations of Transition Objects

abstract:
  Observing objects in transition from pre- to young Planetary Nebula (PN),
when the central star radiation starts to excite the envelope, can help us to
understand the evolution of the circumstellar ejecta and their shaping
mechanism/s. In our project we have selected a sample of hot post-AGB stars as
Transition Phase candidates. Radio observations have led to detect free-free
radiation from an ionized shell in about half of our targets, providing us with
two sub-samples of ionized and non ionized Transition Objects. We are now using
IRAC and IRS on the Spitzer Space Telescope to determine if extended emission
is present (IRAC) and to study our targets' chemistry (IRS). In particular, by
comparing spectra from the two sub-samples, the IRS observations will enable us
to check how the presence of an ionization front effects the circumstellar
envelope. The IRAC measurements, combined with previous ones in the literature,
will give us information on the extent and physical conditions of the dust
components.


title:
Symmetries, conservation laws and exact solutions of static plasma
  equilibrium systems in three dimensions

abstract:
  For static reductions of isotropic and anisotropic Magnetohydrodynamics
plasma equilibrium models, a complete classification of admitted point
symmetries and conservation laws up to first order is presented. It is shown
that the symmetry algebra for the isotropic equations is finite-dimensional,
whereas anisotropic equations admit infinite symmetries depending on a free
function defined on the set of magnetic surfaces. A direct transformation is
established between isotropic and anisotropic equations, which provides an
efficient way of constructing new exact anisotropic solutions. In particular,
axially and helically symmetric anisotropic plasma equilibria arise from
classical Grad-Shafranov and JFKO equations.


title:
The Band Excitation Method in Scanning Probe Microscopy for Rapid
  Mapping of Energy Dissipation on the Nanoscale

abstract:
  Mapping energy transformation pathways and dissipation on the nanoscale and
understanding the role of local structure on dissipative behavior is a
challenge for imaging in areas ranging from electronics and information
technologies to efficient energy production. Here we develop a novel Scanning
Probe Microscopy (SPM) technique in which the cantilever is excited and the
response is recorded over a band of frequencies simultaneously rather than at a
single frequency as in conventional SPMs. This band excitation (BE) SPM allows
very rapid acquisition of the full frequency response at each point (i.e.
transfer function) in an image and in particular enables the direct measurement
of energy dissipation through the determination of the Q-factor of the
cantilever-sample system. The BE method is demonstrated for force-distance and
voltage spectroscopies and for magnetic dissipation imaging with sensitivity
close to the thermomechanical limit. The applicability of BE for various SPMs
is analyzed, and the method is expected to be universally applicable to all
ambient and liquid SPMs.


title: Examples of the Zeroth Theorem of the History of Physics

abstract:
  The zeroth theorem of the history of science (enunciated by E. P. Fischer)
and widely known in the mathematics community as Arnol'd's Principle (decreed
by M. V. Berry), states that a discovery (rule, regularity, insight) named
after someone (often) did not originate with that person. I present five
examples from physics: the Lorentz condition defining the Lorentz gauge of the
electromagnetic potentials; the Dirac delta function (x); the Schumann
resonances of the earth-ionosphere cavity; the Weizsacker-Williams method of
virtual quanta; the BMT equation of spin dynamics. I give illustrated thumbnail
sketches of both the true and reputed discoverers and quote from their
"discovery" publications.


title: Conjugacy and Dynamics in Thompson's Groups

abstract:
  We give a unified solution to the conjugacy problem for Thompson's groups F,
T, and V. The solution uses strand diagrams, which are similar in spirit to
braids and generalize tree-pair diagrams for elements of Thompson's groups.
Strand diagrams are closely related to piecewise-linear functions for elements
of Thompson's groups, and we use this correspondence to investigate the
dynamics of elements of F. Though many of the results in this paper are known,
our approach is new, and it yields elegant proofs of several old results.


title:
Evidence for alignment of the rotation and velocity vectors in pulsars.
  II. Further data and emission heights

abstract:
  We have conducted observations of 22 pulsars at frequencies of 0.7, 1.4 and
3.1 GHz and present their polarization profiles. The observations were carried
out for two main purposes. First we compare the orientation of the spin and
velocity vectors to verify the proposed alignment of these vectors by Johnston
et al. (2005). We find, for the 14 pulsars for which we were able to determine
both vectors, that 7 are plausibly aligned, a fraction which is lower than, but
consistent with, earlier measurements. Secondly, we use profiles obtained
simultaneously at widely spaced frequencies to compute the radio emission
heights. We find, similar to other workers in the field, that radiation from
the centre of the profile originates from lower in the magnetosphere than the
radiation from the outer parts of the profile.


title: The area of horizons and the trapped region

abstract:
  This paper considers some fundamental questions concerning marginally trapped
surfaces, or apparent horizons, in Cauchy data sets for the Einstein equation.
An area estimate for outermost marginally trapped surfaces is proved. The proof
makes use of an existence result for marginal surfaces, in the presence of
barriers, curvature estimates, together with a novel surgery construction for
marginal surfaces. These results are applied to characterize the boundary of
the trapped region.


title:
An exhaustive exploration of the parameter space of the Prisoners'
  Dilemma in one-dimensional cellular automata

abstract:
  The Prisoner's Dilemma (PD) is one of the most popular games of the Game
Theory due to the emergence of cooperation among competitive rational players.
In this paper, we present the PD played in cells of one-dimension cellular
automata, where the number of possible neighbors that each cell interacts, z,
can vary. This makes possible to retrieve results obtained previously in
regular lattices. Exhaustive exploration of the parameters space is presented.
We show that the final state of the system is governed mainly by the number of
neighbors z and there is a drastic difference if it is even or odd.


title: Virtual Yang-Baxter cocycle invariants

abstract:
  We extend the Yang-Baxter cocycle invariants for virtual knots by augmenting
Yang-Baxter 2-cocycles with cocycles from a cohomology theory associated to a
virtual biquandle structure. These invariants coincide with the classical
Yang-Baxter cocycle invariants for classical knots but provide extra
information about virtual knots and links. In particular, they provide a method
for detecting non-classicality of virtual knots and links.


title: Meta-Stable Brane Configurations of Triple Product Gauge Groups

abstract:
  From an N=1 supersymmetric electric gauge theory with the gauge group SU(N_c)
x SU(N_c') x SU(N_c'') with fundamentals for each gauge group and the
bifundamentals, we apply Seiberg dual to each gauge group and obtain the N=1
supersymmetric dual magnetic gauge theories with dual matters including the
additional gauge singlets. By analyzing the F-term equations of the dual
magnetic superpotentials, we describe the intersecting brane configurations of
type IIA string theory corresponding to the meta-stable nonsupersymmetric vacua
of this gauge theory. We apply also to the case for N=1 supersymmetric electric
gauge theory with the gauge group Sp(N_c) x SO(2N_c') x Sp(N_c'') with flavors
for each gauge group and the bifundamentals. Finally, we describe the
meta-stable brane configurations of multiple product gauge groups.


title:
Upper critical field of aligned Na_{x}(H_{3}O)_{z}CoO_{2}\cdot yH_{2}O
  superconductor by magnetization measurement

abstract:
  We present magnetization measurements for the upper critical field $H_{c2}$
on aligned Na$_{x}$(H$_{3}$O)$_{z}$CoO$_{2}\cdot y$H$_{2}$O superconductors
with magnetic field parallel to CoO$_2$ layers. The temperature-dependent part
of the normal-state magnetization $M(H,T)$ can be well scaled with Brillouin
function, suggesting the existence of impurity moments. By subtracting the
contribution of the magnetic impurity moments, a well defined onset of
superconducting diamagnetism allows the in-field superconducting transition
temperature $T_{c}$($H$) accurately determined. No superconducting transition
was observed down to 1.9 K under an applied field of 8 Tesla. The result
suggests that the $H^{\|ab}_{c2}(0)$ value is just within the Pauli
paramagnetic limit, supporting spin-singlet superconductivity in the cobalt
oxyhydrate superconductor. Additionally, the upward curvature near $T_{c}$ in
the $H^{\|ab}_{c2}-T$ phase diagram was confirmed to be intrinsic. Possible
origin of the anomaly was discussed.


title:
Giant magnetoelectric effect under high bias fields in cylindrical
  bilayered Ni-PZT composites

abstract:
  For conventional plate and disc layered magnetoelectric (ME) composites, the
ME effect appeared under low bias magnetic fields, which caused by line
magnetostriction. In this paper, we present a new structure ME composites,
cylindrical bilayered composites. Unexpectedly, the ME effect also appeared
under high magnetic fields in this cylindrical bilayered Ni-lead zirconate
titanate (PZT) composite. We thought this ME effect caused by volume
magnetostriction. The results showed that the ME voltage coefficient of the
cylindrical bilayered composite of Ni-PZT was the sum of aE(l) caused by line
magnetostriction under low bias fields and aE(w) induced by volume
magnetostriction under high fields. At the resonance frequency, aE,A(w)
increased linearly with bias magnetic field HDC to 30 V/cm Oe at HDC =8 kOe,
and was much larger than aE,A(l) at Hm=0.6 kOe. The novel characteristic of ME
voltage coefficient increased linearly with the rise of HDC after 1 kOe in
axial mode makes the cylindrical composite a promising candidate for
application in high magnetic field sensor.


title:
On hitting times and fastest strong stationary times for skip-free and
  more general chains

abstract:
  An (upward) skip-free Markov chain with the set of nonnegative integers as
state space is a chain for which upward jumps may be only of unit size; there
is no restriction on downward jumps. In a 1987 paper, Brown and Shao
determined, for an irreducible continuous-time skip-free chain and any d, the
passage time distribution from state 0 to state d. When the nonzero eigenvalues
nu_j of the generator are all real, their result states that the passage time
is distributed as the sum of d independent exponential random variables with
rates nu_j. We give another proof of their theorem. In the case of
birth-and-death chains, our proof leads to an explicit representation of the
passage time as a sum of independent exponential random variables. Diaconis and
Miclo recently obtained the first such representation, but our construction is
much simpler.
  We obtain similar (and new) results for a fastest strong stationary time T of
an ergodic continuous-time skip-free chain with stochastically monotone
time-reversal started in state 0, and we also obtain discrete-time analogs of
all our results.
  In the paper's final section we present extensions of our results to more
general chains.


title: Phonon anharmonicities in graphite and graphene

abstract:
  We determine from first-principles the finite-temperature
properties--linewidths, line shifts, and lifetimes--of the key vibrational
modes that dominate inelastic losses in graphitic materials. In graphite, the
phonon linewidth of the Raman-active E2g mode is found to decrease with
temperature; such anomalous behavior is driven entirely by electron-phonon
interactions, and does not appear in the nearly-degenerate infrared-active E1u
mode. In graphene, the phonon anharmonic lifetimes and decay channels of the
A'1 mode at K dominate over E2g at G and couple strongly with acoustic phonons,
highlighting how ballistic transport in carbon-based interconnects requires
careful engineering of phonon decays and thermalization.


title: Driven waves in a two-fluid plasma

abstract:
  We study the physics of wave propagation in a weakly ionised plasma, as it
applies to the formation of multifluid, MHD shock waves. We model the plasma as
separate charged and neutral fluids which are coupled by ion-neutral friction.
At times much less than the ion-neutral drag time, the fluids are decoupled and
so evolve independently. At later times, the evolution is determined by the
large inertial mismatch between the charged and neutral particles. The neutral
flow continues to evolve independently; the charged flow is driven by and
slaved to the neutral flow by friction. We calculate this driven flow
analytically by considering the special but realistic case where the charged
fluid obeys linearized equations of motion. We carry out an extensive analysis
of linear, driven, MHD waves. The physics of driven MHD waves is embodied in
certain Green functions which describe wave propagation on short time scales,
ambipolar diffusion on long time scales, and transitional behavior at
intermediate times. By way of illustration, we give an approximate solution for
the formation of a multifluid shock during the collision of two identical
interstellar clouds. The collision produces forward- and reverse J shocks in
the neutral fluid and a transient in the charged fluid. The latter rapidly
evolves into a pair of magnetic precursors on the J shocks, wherein the ions
undergo force free motion and the magnetic field grows monotonically with time.
The flow appears to be self similar at the time when linear analysis ceases to
be valid.


title:
World Sheet Commuting \beta\gamma CFT and Non-Relativistic String
  Theories

abstract:
  We construct a sigma model in two dimensions with Galilean symmetry in flat
target space similar to the sigma model of the critical string theory with
Lorentz symmetry in 10 flat spacetime dimensions. This is motivated by the
works of Gomis and Ooguri\cite{Gomis:2000bd} and Danielsson et. al.
\cite{Danielsson:2000gi, Danielsson:2000mu}. Our theory is much simpler than
their theory and does not assume a compact coordinate. This non-relativistic
string theory has a bosonic matter $\beta\gamma$ CFT with the conformal weight
of $\beta$ as 1. It is natural to identify time as a linear combination of
$\gamma$ and $\bar{\gamma}$ through an explicit realization of the Galilean
boost symmetry. The angle between $\gamma$ and $\bar{\gamma}$ parametrizes one
parameter family of selection sectors. These selection sectors are responsible
for having a non-relativistic dispersion relation without a nontrivial topology
in the non-relativistic setup, which is one of the major differences from the
previous works\cite{Gomis:2000bd, Danielsson:2000gi, Danielsson:2000mu}. This
simple theory is the non-relativistic analogue of the critical string theory,
and there are many different avenues ahead to be investigated. We mention a
possible consistent generalization of this theory with different conformal
weights for the $\beta\gamma$ CFT. We also mention supersymmetric
generalizations of these theories.


title:
The spectral sequence of an equivariant chain complex and homology with
  local coefficients

abstract:
  We study the spectral sequence associated to the filtration by powers of the
augmentation ideal on the (twisted) equivariant chain complex of the universal
cover of a connected CW-complex X. In the process, we identify the d^1
differential in terms of the coalgebra structure of H_*(X,\k), and the
\k\pi_1(X)-module structure on the twisting coefficients. In particular, this
recovers in dual form a result of Reznikov, on the mod p cohomology of cyclic
p-covers of aspherical complexes. This approach provides information on the
homology of all Galois covers of X. It also yields computable upper bounds on
the ranks of the cohomology groups of X, with coefficients in a prime-power
order, rank one local system. When X admits a minimal cell decomposition, we
relate the linearization of the equivariant cochain complex of the universal
abelian cover to the Aomoto complex, arising from the cup-product structure of
H^*(X,\k), thereby generalizing a result of Cohen and Orlik.


title: Screening of Coulomb Impurities in Graphene

abstract:
  We calculate exactly the vacuum polarization charge density in the field of a
subcritical Coulomb impurity, $Z|e|/r$, in graphene. Our analysis is based on
the exact electron Green's function, obtained by using the operator method, and
leads to results that are exact in the parameter $Z\alpha$, where $\alpha$ is
the "fine structure constant" of graphene. Taking into account also
electron-electron interactions in the Hartree approximation, we solve the
problem self-consistently in the subcritical regime, where the impurity has an
effective charge $Z_{eff}$, determined by the localized induced charge. We find
that an impurity with bare charge Z=1 remains subcritical, $Z_{eff} \alpha <
1/2$, for any $\alpha$, while impurities with $Z=2,3$ and higher can become
supercritical at certain values of $\alpha$.


title: Regularity of a inverse problem for generic parabolic equations

abstract:
  The paper studies some inverse boundary value problem for simplest parabolic
equations such that the homogenuous Cauchy condition is ill posed at initial
time. Some regularity of the solution is established for a wide class of
boundary value inputs.


title: Measurement of electro-magnetic radiation at RHIC-PHENIX

abstract:
  Recent results on direct photons and dileptons from the PHENIX experiment
opened up a possibility of landscaping electro-magnetic radiation over various
kinetic energies in heavy ion collisions. Results on direct photon measurement
in Au+Au collisions at $\sqrt{s_{NN}}$=200GeV are discussed from the point of
view of structure function and isospin effect. It is supported by the first
measurement of direct photons at $\sqrt{s_{NN}}$=62.4GeV in the same
collisional system.


title: Absorbing boundary conditions for Einstein's field equations

abstract:
  A common approach for the numerical simulation of wave propagation on a
spatially unbounded domain is to truncate the domain via an artificial
boundary, thus forming a finite computational domain with an outer boundary.
Absorbing boundary conditions must then be specified at the boundary such that
the resulting initial-boundary value problem is well posed and such that the
amount of spurious reflection is minimized. In this article, we review recent
results on the construction of absorbing boundary conditions in General
Relativity and their application to numerical relativity.


title: Soft-pulse dynamical decoupling in a cavity

abstract:
  Dynamical decoupling is a coherent control technique where the intrinsic and
extrinsic couplings of a quantum system are effectively averaged out by
application of specially designed driving fields (refocusing pulse sequences).
This entails pumping energy into the system, which can be especially dangerous
when it has sharp spectral features like a cavity mode close to resonance. In
this work we show that such an effect can be avoided with properly constructed
refocusing sequences. To this end we construct the average Hamiltonian
expansion for the system evolution operator associated with a single ``soft''
pi-pulse. To second order in the pulse duration, we characterize a symmetric
pulse shape by three parameters, two of which can be turned to zero by shaping.
We express the effective Hamiltonians for several pulse sequences in terms of
these parameters, and use the results to analyze the structure of error
operators for controlled Jaynes-Cummings Hamiltonian. When errors are cancelled
to second order, numerical simulations show excellent qubit fidelity with
strongly-suppressed oscillator heating.


title: Shell model study of the pairing correlations

abstract:
  A systematic study of the pairing correlations as a function of temperature
and angular momentum has been performed in the sd-shell region using the
spherical shell model approach. The pairing correlations have been derived for
even-even, even-odd and odd-odd systems near N=Z and also for the asymmetric
case of N=Z+4. The results indicate that the pairing content and the behavior
of pair correlations is similar in even-even and odd-mass nuclei. For odd-odd
N=Z system, angular momentum I=0 state is an isospin, t=1 neutron-proton paired
configuration. Further, these t=1 correlations are shown to be dramatically
reduced for the asymmetric case of N=Z+4. The shell model results obtained are
qualitatively explained within a simplified degenerate model.


title: Van der Waals interactions in DFT made easy by Wannier functions

abstract:
  Ubiquitous Van der Waals interactions between atoms and molecules are
important for many molecular and solid structures. These systems are often
studied from first principles using the Density Functional Theory (DFT).
However, the commonly used DFT functionals fail to capture the essence of Van
der Waals effects. Many attempts to correct for this problem have been
proposed, which are not completely satisfactory because they are either very
complex and computationally expensive or have a basic semiempirical character.
We here describe a novel approach, based on the use of the Maximally-Localized
Wannier functions, that appears to be promising, being simple, efficient,
accurate, and transferable (charge polarization effects are naturally
included). The results of test applications are presented.


title: New Construction of \Delta-Operator in Field-Antifield Formalism

abstract:
  It is proven that the nilpotent $\Delta$-operator in the field-antifield
formalism can be constructed in terms of an antisymplectic structure only.


title: Canonical 2-forms on the moduli space of Riemann surfaces

abstract:
  As was shown by Harer the second homology of ${\mathbb M}_g$, the moduli
space of compact Riemann surfaces of genus $g$, is of rank 1, provided $g \geq
3$. This means a nontrivial second de Rham cohomology class on ${\mathbb M}_g$
is unique up to constant factor. But several canonical 2-forms on the moduli
space have been constructed in various geometric contexts, and differ from each
other. In this article we review some of constructions in order to provide
materials for future research on "secondary geometry" of the moduli space
${\mathbb M}_g$.


title:
Normal approximation for nonlinear statistics using a concentration
  inequality approach

abstract:
  Let $T$ be a general sampling statistic that can be written as a linear
statistic plus an error term. Uniform and non-uniform Berry--Esseen type bounds
for $T$ are obtained. The bounds are the best possible for many known
statistics. Applications to U-statistics, multisample U-statistics,
L-statistics, random sums and functions of nonlinear statistics are discussed.


title:
Decision table for classifying point sources based on FIRST and 2MASS
  databases

abstract:
  With the availability of multiwavelength, multiscale and multiepoch
astronomical catalogues, the number of features to describe astronomical
objects has increases. The better features we select to classify objects, the
higher the classification accuracy is. In this paper, we have used data sets of
stars and quasars from near infrared band and radio band. Then best-first
search method was applied to select features. For the data with selected
features, the algorithm of decision table was implemented. The classification
accuracy is more than 95.9%. As a result, the feature selection method improves
the effectiveness and efficiency of the classification method. Moreover the
result shows that decision table is robust and effective for discrimination of
celestial objects and used for preselecting quasar candidates for large survey
projects.


title: Comparison of decision tree methods for finding active objects

abstract:
  The automated classification of objects from large catalogues or survey
projects is an important task in many astronomical surveys. Faced with various
classification algorithms, astronomers should select the method according to
their requirements. Here we describe several kinds of decision trees for
finding active objects by multi-wavelength data, such as REPTree, Random Tree,
Decision Stump, Random Forest, J48, NBTree, AdTree. All decision tree
approaches investigated are in the WEKA package. The classification performance
of the methods is presented. In the process of classification by decision tree
methods, the classification rules are easily obtained, moreover these rules are
clear and easy to understand for astronomers. As a result, astronomers are
inclined to prefer and apply them, thus know which attributes are important to
discriminate celestial objects. The experimental results show that when various
decision trees are applied in discriminating active objects (quasars, BL Lac
objects and active galaxies) from non-active objects (stars and galaxies),
ADTree is the best only in terms of accuracy, Decision Stump is the best only
considering speed, J48 is the optimal choice considering both accuracy and
speed.


title: Continuation of solutions of coupled dynamical systems

abstract:
  Recently, the synchronization of coupled dynamical systems has been widely
studied. Synchronization is referred to as a process wherein two (or many)
dynamical systems are adjusted to a common behavior as time goes to infinity,
due to coupling or forcing. Therefore, before discussing synchronization, a
basic problem on continuation of the solution must be solved: For given initial
conditions, can the solution of coupled dynamical systems be extended to the
infinite interval $[0,+\infty)$? In this paper, we propose a general model of
coupled dynamical systems, which includes previously studied systems as special
cases, and prove that under the assumption of QUAD, the solution of the general
model exists on $[0,+\infty)$.


title: Observation of False Spherical Micrometeorites

abstract:
  The work describes the results of the study of the spherical particles that
can be found in the environment and that were often considered as
micrometeorites. The results have demonstrated that in the most of cases these
spherical particles are the results of the human activity.


title: Rare tau decays

abstract:
  A review is presented of the current status of experimental searches for
physics beyond the standard model in rare $\tau$ decays.


title: Lefschetz numbers for C*-algebras

abstract:
  Using Poincare duality, we formulate a formula of Lefschetz type which
computes the Lefschetz number of an endomorphism of a separable, nuclear
C*-algebra satisfying Poincare duality and the Kunneth theorem. (The Lefschetz
number of an endomorphism is the graded trace of the induced map on K-theory
tensored with the complex numbers, as in the classical case.) We then consider
endomorphisms of Cuntz-Krieger algebras O_A. An endomorphism has an invariant,
which is a permutation of an infinite set, and the contracting and expanding
behavior of this permutation describes the Lefschetz number of the
endomorphism. Using this description we derive a closed polynomial formula for
the Lefschetz number depending on the matrix A and the presentation of the
endomorphism.


title: A Lefschetz fixed-point formula for certain orbifold C*-algebras

abstract:
  Using Poincar\'e duality in K-theory, we state and prove a Lefschetz fixed
point formula for endomorphisms of cross product C*-algebras $C_0(X)\cross G$
coming from covariant pairs. Here $G$ is assumed countable, $X$ a manifold, and
$X\cross G$ cocompact and proper.
  The formula in question expresses the graded trace of the map on rationalized
K-theory of $C_0(X)\cross G$ induced by the endomorphism, \emph{i.e.} the
Lefschetz number, in terms of fixed orbits and representation-theoretic data
connected with certain isotropy subgroups of the isotropy group at that point.
The technique is to use noncommutative Poinca\'e duality and the formal
Lefschetz lemma of the second author.


title: Compact radio jets and nuclear regions in active galaxies

abstract:
  VLBI observations of relativistic outflows (jets) in galactic nuclei,
complemented with detailed studies made in other spectral domains, have become
an effective tool for investigating the physics of nuclear regions in galaxies.
High-resolution radio observations access directly the regions where the jets
are formed, and trace their evolution and interaction with the nuclear
environment. The emission properties, dynamics, and evolution of jets in AGN
are intimately connected to the characteristics of the central supermassive
black hole, accretion disk, and broad-line region (BLR) in active galaxies.
Large VLBI surveys (15GHz VLBA survey, MOJAVE) and dedicated monitoring
programmes follow systematically the evolution of several hundreds of
relativistic jets. These observations, combined with optical and X-ray studies,
yield arguably the most detailed picture of the galactic nuclei. Recent results
from studies of the nuclear regions in several active galaxies with prominent
outflows are reviewed in this contribution.


title: Multi-channel architecture for electronic quantum-Hall interferometry

abstract:
  We propose a new architecture for implementing electronic interferometry in
quantum Hall bars. It exploits scattering among parallel edge channels. In
contrast to previous developments, this one employs a simply-connected mesa
admitting serial concatenation of building elements closer to optical
analogues. Implementations of Mach-Zehnder and Hambury-Brown-Twiss
interferometers are discussed together with new structures yet unexplored in
quantum electronics.


title: Asymptotic Error Rates in Quantum Hypothesis Testing

abstract:
  We consider the problem of discriminating between two different states of a
finite quantum system in the setting of large numbers of copies, and find a
closed form expression for the asymptotic exponential rate at which the
specified error probability tends to zero. This leads to the identification of
the quantum generalisation of the classical Chernoff distance.
  The proof relies on two new techniques that have been introduced in
[quant-ph/0610027] and [quant-ph/0607216], respectively, and that are also well
suited to prove the quantum generalisation of the Hoeffding bound, which is a
modification of the Chernoff distance and specifies the optimal achievable
asymptotic error rate in the context of asymmetric hypothesis testing. This has
been done subsequently by Hayashi [quant-ph/0611013] and Nagaoka
[quant-ph/0611289] for the special case where both hypotheses have full
support.
  Moreover, quantum Stein's Lemma and quantum Sanov's theorem may be derived
directly from the quantum Hoeffding bound combining it with a result obtained
recently in [math/0703772].
  The goal of this paper is to present the proofs of the above mentioned
results in a unified way and in full generality (allowing hypothetic states
with different supports). Additionally, we give an in-depth treatment of the
properties of the quantum Chernoff distance. We argue that, although it is not
a metric, it is a natural distance measure on the set of density operators, due
to its clear operational meaning.


title:
Correction to: The scaling limit behaviour of periodic stable-like
  processes

abstract:
  Correction to Bernoulli (2006), 12, 551--570
http://projecteuclid.org/euclid.bj/1151525136


title: Optimal Per-Edge Processing Times in the Semi-Streaming Model

abstract:
  We present semi-streaming algorithms for basic graph problems that have
optimal per-edge processing times and therefore surpass all previous
semi-streaming algorithms for these tasks. The semi-streaming model, which is
appropriate when dealing with massive graphs, forbids random access to the
input and restricts the memory to O(n*polylog n) bits.
  Particularly, the formerly best per-edge processing times for finding the
connected components and a bipartition are O(alpha(n)), for determining
k-vertex and k-edge connectivity O(k^2n) and O(n*log n) respectively for any
constant k and for computing a minimum spanning forest O(log n). All these time
bounds we reduce to O(1).
  Every presented algorithm determines a solution asymptotically as fast as the
best corresponding algorithm up to date in the classical RAM model, which
therefore cannot convert the advantage of unlimited memory and random access
into superior computing times for these problems.


title: Constraints on Wrapped DBI Inflation in a Warped Throat

abstract:
  We derive constraints on the tensor to scalar ratio and on the background
charge of the warped throat for DBI inflation driven by D5- and D7-branes
wrapped over cycles of the throat. It is shown that the background charge well
beyond the known maximal value is required in most cases for DBI inflation to
generate cosmological observables compatible with the WMAP3 data. Most of the
results derived in this paper are insensitive to the details of the inflaton
potential, and could be applied to generic warped throats.


title:
Tunability of wire-grid metamaterial immersed into nematic liquid
  crystal

abstract:
  We propose electrically tunable hybrid metamaterial consisting of special
wire grid immersed into nematic liquid crystal. The plasma-like permittivity of
the structure can be substantially varied due to switching of the liquid
crystal alignment by external voltages applied to the wires. Depending on the
scale of the structure, the effect is available for both microwave and optical
frequency ranges.


title: Dynamical sensitivity of the infinite cluster in critical percolation

abstract:
  In dynamical percolation, the status of every bond is refreshed according to
an independent Poisson clock. For graphs which do not percolate at criticality,
the dynamical sensitivity of this property was analyzed extensively in the last
decade. Here we focus on graphs which percolate at criticality, and investigate
the dynamical sensitivity of the infinite cluster. We first give two examples
of bounded degree graphs, one which percolates for all times at criticality and
one which has exceptional times of nonpercolation. We then make a nearly
complete analysis of this question for spherically symmetric trees with
spherically symmetric edge probabilities bounded away from 0 and 1. One
interesting regime occurs when the expected number of vertices at the nth level
that connect to the root at a fixed time is of order n(\log n)^\alpha. R. Lyons
(1990) showed that at a fixed time, there is an infinite cluster a.s. if and
only if \alpha >1. We prove that the probability that there is an infinite
cluster at all times is 1 if \alpha > 2, while this probability is 0 if
1<\alpha \le 2. Within the regime where a.s. there is an infinite cluster at
all times, there is yet another type of ``phase transition'' in the behavior of
the process: if the expected number of vertices at the nth level connecting to
the root at a fixed time is of order n^\theta with \theta > 2, then the number
of connected components of the set of times in [0,1] at which the root does not
percolate is finite a.s., while if 1<\theta < 2, then the number of such
components is infinite with positive probability.


title: Pattern Matching in Trees and Strings

abstract:
  We study the design of efficient algorithms for combinatorial pattern
matching. More concretely, we study algorithms for tree matching, string
matching, and string matching in compressed texts.


title:
The rest mass of a system of two photons in different inertial reference
  frames: 0+0=0 and 0+0>0

abstract:
  We show that the rest mass of a system consisting of two photons is a
relativistic invariant having the same magnitude in all inertial reference
frames in relative motion. A scenario which starts with two photons where
theirs frequencies are equal to each other the magnitude of the rest mass of
the system depends on the angle made by the momentums of the two photons. The
behavior of the photons when detected from two inertial reference frames is
illustrated using a relativistic diagram which displays in true values the
physical quantities (scalar and vector) introduced in order to characterize the
dynamical properties of the photon. We consider that the obtained results
should be taken in the discussions, some time fierce, between those who ban the
concept of relativistic mass and those who consider that its use is harmless.


title:
Near-infrared and Mid-infrared Spectroscopy with the Infrared Camera
  (IRC) for AKARI

abstract:
  The Infrared Camera (IRC) is one of the two instruments on board the AKARI
satellite. In addition to deep imaging from 1.8-26.5um for the pointed
observation mode of the AKARI, it has a spectroscopic capability in its
spectral range. By replacing the imaging filters by transmission-type
dispersers on the filter wheels, it provides low-resolution (lambda/d_lambda ~
20-120) spectroscopy with slits or in a wide imaging field-of-view
(approximately 10'X10'). The IRC spectroscopic mode is unique in space infrared
missions in that it has the capability to perform sensitive wide-field
spectroscopic surveys in the near- and mid-infrared wavelength ranges. This
paper describes specifications of the IRC spectrograph and its in-orbit
performance.


title:
Polymer and surface roughness effects on the drag crisis for falling
  spheres

abstract:
  We make time resolved velocity measurements of steel spheres in free fall
through liquid using a continuous ultrasound technique. We explore two
different ways to induce large changes in drag on the spheres: 1) a small
quantity of viscoelastic polymer added to water and 2) altering the surface of
the sphere. Low concentration polymer solutions and/or a pattern of grooves in
the sphere surface induce an early drag crisis, which may reduce drag by more
than 50 percent compared to smooth spheres in pure water. On the other hand,
random surface roughness and/or high concentration polymer solutions reduce
drag progressively and suppress the drag crisis. We also present a
qualititative argument which ties the drag reduction observed in low
concentration polymer solutions to the Weissenberg number and normal stress
difference.


title:
The evolution of planetary nebulae IV. On the physics of the luminosity
  function

abstract:
  The nebular evolution is followed from the vicinity of the asymptotic-giant
branch across the Hertzsprung-Russell diagram until the white-dwarf domain is
reached, using various central-star models coupled to different initial
envelope configurations. Along each sequence the relevant line emissions of the
nebulae are computed and analysed. Maximum line luminosities in Hbeta and
[OIII] 5007A are achieved at stellar effective temperatures of about 65000K and
95000-100000K, respectively, provided the nebula remains optically thick for
ionising photons. In the optically thin case, the maximum line emission occurs
at or shortly after the thick/thin transition. Our models suggest that most
planetary nebulae with hotter (>~ 45000K) central stars are optically thin in
the Lyman continuum, and that their [OIII] 5007A emission fails to explain the
bright end of the observed planetary nebulae luminosity function. However,
sequences with central stars of >~ 0.6 Msun and rather dense initial envelopes
remain virtually optically thick and are able to populate the bright end of the
luminosity function. Individual luminosity functions depend strongly on the
central-star mass and on the variation of the nebular optical depth with time.
Hydrodynamical simulations of planetary nebulae are essential for any
understanding of the basic physics behind their observed luminosity function.
In particular, our models do not support the claim of Marigo et.al (2004)
according to which the maximum 5007A luminosity occurs during the recombination
phase well beyond 100 000K when the stellar luminosity declines and the nebular
models become, at least partially, optically thick. Consequently, there is no
need to invoke relatively massive central stars of, say > 0.7 Msun, to account
for the bright end of the luminosity function.


title: Viscous Withdrawal of Miscible Liquid Layers

abstract:
  In viscous withdrawal, a converging flow imposed in an upper layer of viscous
liquid entrains liquid from a lower, stably stratified layer. Using the idea
that a thin tendril is entrained by a local straining flow, we propose a
scaling law for the volume flux of liquid entrained from miscible liquid
layers. A long-wavelength model including only local information about the
withdrawal flow is degenerate, with multiple tendril solutions for one
withdrawal condition. Including information about the global geometry of the
withdrawal flow removes the degeneracy while introducing only a logarithmic
dependence on the global flow parameters into the scaling law.


title:
Large sample asymptotics for the two-parameter Poisson--Dirichlet
  process

abstract:
  This paper explores large sample properties of the two-parameter
$(\alpha,\theta)$ Poisson--Dirichlet Process in two contexts. In a Bayesian
context of estimating an unknown probability measure, viewing this process as a
natural extension of the Dirichlet process, we explore the consistency and weak
convergence of the the two-parameter Poisson--Dirichlet posterior process. We
also establish the weak convergence of properly centered two-parameter
Poisson--Dirichlet processes for large $\theta+n\alpha.$ This latter result
complements large $\theta$ results for the Dirichlet process and
Poisson--Dirichlet sequences, and complements a recent result on large
deviation principles for the two-parameter Poisson--Dirichlet process. A
crucial component of our results is the use of distributional identities that
may be useful in other contexts.


title:
Numerical study on Schramm-Loewner Evolution in nonminimal conformal
  field theories

abstract:
  The Schramm-Loewner evolution (SLE) is a powerful tool to describe fractal
interfaces in 2D critical statistical systems. Yet the application of SLE is
well established for statistical systems described by quantum field theories
satisfying only conformal invariance, the so called minimal conformal field
theories (CFTs). We consider interfaces in Z(N) spin models at their self-dual
critical point for N=4 and N=5. These lattice models are described in the
continuum limit by non-minimal CFTs where the role of a Z_N symmetry, in
addition to the conformal one, should be taken into account. We provide
numerical results on the fractal dimension of the interfaces which are SLE
candidates for non-minimal CFTs. Our results are in excellent agreement with
some recent theoretical predictions.


title: Nuclear physics with spherically symmetric supernova models

abstract:
  Few years ago, Boltzmann neutrino transport led to a new and reliable
generation of spherically symmetric models of stellar core collapse and
postbounce evolution. After the failure to prove the principles of the
supernova explosion mechanism, these sophisticated models continue to
illuminate the close interaction between high-density matter under extreme
conditions and the transport of leptons and energy in general relativistically
curved space-time. We emphasize that very different input physics is likely to
be relevant for the different evolutionary phases, e.g. nuclear structure for
weak rates in collapse, the equation of state of bulk nuclear matter during
bounce, multidimensional plasma dynamics in the postbounce evolution, and
neutrino cross sections in the explosive nucleosynthesis. We illustrate the
complexity of the dynamics using preliminary 3D MHD high-resolution simulations
based on parameterized deleptonization. With established spherically symmetric
models we show that typical features of the different phases are reflected in
the predicted neutrino signal and that a consistent neutrino flux leads to
electron fractions larger than 0.5 in neutrino-driven supernova ejecta.


title:
The Two-Photon-Exchange and \gamma Z-Exchange Corrections to
  parity-Violating Elastic Electron-Proton Scattering

abstract:
  Leading electroweak corrections play an important role in precision
measurements of the strange form factors. We calculate the two-photon-exchange
(TPE) and $\gamma Z$-exchange corrections to the parity-violating asymmetry of
the elastic electron-proton scattering in a simple hadronic model including the
finite size of the proton. We find both can reach a few percent and are
comparable in size with the current experimental measurements of strange-quark
effects in the proton neutral weak current. The effect of $\gamma Z$-exchange
is in general larger than that of TPE, especially at low momentum transfer
$Q^2\le 1 GeV^2$. Their combined effects on the values of $G^s_E+\beta G^s_M$
extracted in recent experiments can be as large as -40% in certain kinematics.


title: Dilatation structures in sub-riemannian geometry

abstract:
  Based on the notion of dilatation structure arXiv:math/0608536, we give an
intrinsic treatment to sub-riemannian geometry, started in the paper
arXiv:0706.3644 .
  Here we prove that regular sub-riemannian manifolds admit dilatation
structures. From the existence of normal frames proved by Bellaiche we deduce
the rest of the properties of regular sub-riemannian manifolds by using the
formalism of dilatation structures.


title:
Robinson-Trautman spacetimes with an electromagnetic field in higher
  dimensions

abstract:
  We investigate higher dimensional Robinson-Trautman spacetimes with an
electromagnetic field aligned with the hypersurface orthogonal, non-shearing,
expanding geodesic null congruence. After integrating the system of
Einstein-Maxwell equations with an arbitrary cosmological constant, we present
the complete family of solutions. In odd spacetime dimensions they represent
(generalized) Reissner-Nordstrom-de Sitter black holes. The event horizon (more
generically, the transverse space) may be any Einstein space, and the full
metric is specified by three independent parameters related to mass, electric
charge and cosmological constant. These solutions also exhaust the class of
Robinson-Trautman spacetimes with an aligned Maxwell-Chern-Simons field (the CS
term must vanish because of the alignment assumption and of the Einstein
equations). In even dimensions an additional magnetic "monopole-like" parameter
is also allowed provided now the transverse space is an (almost-)Kahler
Einstein manifold. The Weyl tensor of all such solutions is of algebraic type
D. We also consider the possible inclusion of aligned pure radiation.


title:
Limits on the 2.2 microns contrast ratio of the close orbiting planet HD
  189733b

abstract:
  We obtained 238 spectra of the close orbiting extrasolar giant planet HD
189733b with resolution R ~ 15,000 during one night of observations with the
near infrared spectrograph, NIRSPEC, at the Keck II Telescope. We have searched
for planetary absorption signatures in the 2.0 - 2.4 micron region where H_2O
and CO are expected to be the dominant atmospheric opacities. We employ a phase
dependent orbital model and tomographic techniques to search for the planetary
absorption signatures in the combined stellar and planetary spectra. Because
potential absorption signatures are hidden in the noise of each single
exposure, we use a model list of lines to apply a spectral deconvolution. The
resulting mean profile possesses a S/N ratio that is 20 times greater than that
found in individual lines. Our spectral timeseries thus yields spectral
signatures with a mean S/N = 2720. We are unable to detect a planetary
signature at a contrast ratio of log_10(F_p/F_*) = -3.40, with 63.8 per cent
confidence. Our findings are not consistent with model predictions which
nevertheless give a good fit to mid-infrared observations of HD 189733. The
1-sigma result is a factor of 1.7 times less than the predicted 2.185 micron
planet/star flux ratio of log_10(F_p/F_*) ~ -3.16.


title: Zooming into the large circumstellar disk in M 17

abstract: This paper has been withdrawn by the authors.


title: On the photon polarization in radiative B -> phi K gamma decay

abstract:
  The photon polarization in radiative decays B -> Y gamma is known to be a
subtle probe of the effective Lagrangian structure and possible New Physics
effects. We discuss exclusive decay mode B -> phi K gamma where the
experimentally distinct final state makes analysis especially promising. The
possibility to extract information on the photon polarization out of the data
entirely depends on the partial waves interference pattern in the phi K system.


title: Nonperturbative ghost dynamics in the maximal Abelian gauge

abstract:
  We construct the effective potential for the ghost condensate
<f^{abi}\bar{c}^a c^b> in the maximal Abelian gauge. This condensate is an
order parameter for a global continuous symmetry, which is spontaneously broken
since a nonvanishing value of <f^{abi}\bar{c}^a c^b> lowers the vacuum energy.
The associated Goldstone mode turns out to be unphysical.


title: Control of atomic currents using a quantum stirring device

abstract:
  We propose a BEC stirring device which can be regarded as the incorporation
of a quantum pump into a closed circuit: it produces a DC circulating current
in response to a cyclic adiabatic change of two control parameters of an
optical trap. We demonstrate the feasibility of this concept and point out that
such device can be utilized in order to probe the interatomic interactions.


title: Gauge-Higgs Unification from the Heterotic String

abstract:
  We present a 6D orbifold model on $T^2/\Z2$ which emerges as intermediate
step in the compactification of the heterotic string to the supersymmetric
standard model in four dimensions. It has $\SU6$ gauge symmetry in the bulk and
two pairs of inequivalent fixed points with unbroken $\SU5$ and $\SU2 \times
\SU4$ symmetry, respectively. All anomalies are cancelled by the Green-Schwarz
mechanism. Two quark-lepton generations are located at the $\SU5$ branes, the
third family is composed of split bulk hypermultiplets. The model has vacua
with partial or full gauge-Higgs unification and non-vanishing Yukawa couplings
which generically avoid the unsuccessful $\SU5$ mass relations.


title: Blazar microvariability at hard X-rays

abstract:
  Blazars are known to display strong and erratic variability at almost all the
wavelengths of electromagnetic spectrum. Presently, variability studies at
high-energies (hard X-rays, gamma-rays) are hampered by low sensitivity of the
instruments. Nevertheless, the latest generation of satellites (INTEGRAL,
Swift) have given suggestions not yet fully confirmed of variability on
intraday timescales. Some specific cases recently observed are presented and
physical implications are discussed (e.g. NRAO 530). The contribution that
SIMBOL-X could give in this research topic is also outlined.


title: Vector Optimization by Two Objective Functions

abstract:
  Recently wide application in engineering-economic problems was received with
problems of vector optimization. Development of methods of the decision of
these problems it is executed in works A. Messac and others. Complexity of the
offered methods consists in construction of an aggregate objective function. In
the given work an algorithm of the solution of a vector optimization problem is
suggested carry out by use analytical representation of Pareto cone.


title:
Piecing Together the X-ray Background: Bolometric Corrections for Active
  Galactic Nuclei

abstract:
  (Abridged) The X-ray background can be used to constrain the accretion
history of Supermassive Black Holes (SMBHs) in Active Galactic Nuclei (AGN). A
knowledge of the hard X-ray bolometric correction, \kappa_{2-10keV} is a vital
input into these studies. Variations in the disk emission in the UV have not
previously been taken into account in calculating \kappa_{2-10keV}; we show
that such variations are important by constructing optical--to--X-ray SEDs for
54 AGN. In particular, we use FUSE UV and X-ray data from the literature to
constrain the disk emission as well as possible. Previous work has suggested a
dependence of \kappa_{2-10keV} on AGN luminosity, but we find significant
spread in \kappa_{2-10keV} with no simple dependence on luminosity. Populations
such as Narrow-Line Seyfert 1 nuclei (NLS1s), Radio Loud and X-ray Weak AGN may
have values of \kappa_{2-10keV} differing systematically from the rest of the
AGN population. Other sources of uncertainty include intrinsic extinction in
the optical--UV, X-ray and UV variability and uncertainties in SMBH mass
estimates. Our results suggest a more well-defined relationship between
\kappa_{2-10keV} and Eddington ratio in AGN, with a transitional region at an
Eddington ratio of ~0.1, below which the bolometric correction is typically 15
- 25, and above which it is typically 40 - 70. We consider the potential
implied parallels with the low/hard and high/soft states in Galactic Black Hole
(GBH) accretion, and present bolometric corrections for the GBH binary GX 339-4
for comparison. Our findings reinforce previous studies proposing a multi-state
description of AGN accretion analogous to that for GBH binaries. Future
calculations of the SMBH mass density may need to account for the possible
dependence of \kappa_{2-10keV} on Eddington ratio.


title:
Hinode EUV Imaging Spectrometer Observations of Solar Active Region
  Dynamics

abstract:
  The EUV Imaging Spectrometer (EIS) on the Hinode satellite is capable of
measuring emission line center positions for Gaussian line profiles to a
fraction of a spectral pixel, resulting in relative solar Doppler-shift
measurements with an accuracy of less than a km/s for strong lines. We show an
example of the application of that capability to an active region sit-and-stare
observation in which the EIS slit is placed at one location on the Sun and many
exposures are taken while the spacecraft tracking keeps the same solar location
within the slit. For the active region examined (NOAA 10930), we find that
significant intensity and Doppler-shift fluctuations as a function of time are
present at a number of locations. These fluctuations appear to be similar to
those observed in high-temperature emission lines with other space-borne
spectroscopic instruments. With its increased sensitivity over earlier
spectrometers and its ability to image many emission lines simultaneously, EIS
should provide significant new constraints on Doppler-shift oscillations in the
corona.


title: Z_2 actions on complexes with three non-trivial cells

abstract:
  In this paper, we study $Z_2$ actions on a cell complex X having the
cohomology ring isomorphic to that of the wedge sum $P^2 (n) V S^{3n}$ or $S^n
V S^{2n} V S^{3n}$. We determine the possible fixed point sets depending on
whether or not X is totally non-homologous to zero in $X_{Z_2}$ and give
examples realizing the possible cases.


title:
2006: Celebrating 75 years of AI - History and Outlook: the Next 25
  Years

abstract:
  When Kurt Goedel layed the foundations of theoretical computer science in
1931, he also introduced essential concepts of the theory of Artificial
Intelligence (AI). Although much of subsequent AI research has focused on
heuristics, which still play a major role in many practical AI applications, in
the new millennium AI theory has finally become a full-fledged formal science,
with important optimality results for embodied agents living in unknown
environments, obtained through a combination of theory a la Goedel and
probability theory. Here we look back at important milestones of AI history,
mention essential recent results, and speculate about what we may expect from
the next 25 years, emphasizing the significance of the ongoing dramatic
hardware speedups, and discussing Goedel-inspired, self-referential,
self-improving universal problem solvers.


title: Qubit Entanglement Driven by Remote Optical Fields

abstract:
  We examine the entanglement between two qubits, supposed to be remotely
located and driven by independent quantized optical fields. No interaction is
allowed between the qubits, but their degree of entanglement changes as a
function of time. We report a collapse and revival of entanglement that is
similar to the collapse and revival of single-atom properties in cavity QED.


title:
Hopping transport of interacting carriers in disordered organic
  materials

abstract:
  Computer simulation of the hopping charge transport in disordered organic
materials has been carried out explicitly taking into account charge-charge
interactions. This approach provides a possibility to take into account dynamic
correlations that are neglected by more traditional approaches like mean field
theory. It was found that the effect of interaction is no less significant than
the usually considered effect of filling of deep states by non-interacting
carriers. It was found too that carrier mobility generally increases with the
increase of carrier density, but the effect of interaction is opposite for two
models of disordered organic materials: for the non-correlated random
distribution of energies with Gaussian DOS mobility decreases with the increase
of the interaction strength, while for the model with long range correlated
disorder mobility increases with the increase of interaction strength.


title: Vector meson electroproduction within GPD approach

abstract:
  We analyze electroproduction of light vector meson at small Bjorken $x$
within the generalized parton distribution (GPD) approach. Calculation is based
on the modified perturbative approach, where the quark transverse degrees of
freedom in the hard subprocess are considered. Our results on the cross section
are in fair agreement with experiment from HERMES to HERA energies.


title: Brittle fracture down to femto-Joules - and below

abstract:
  We analyze large sets of energy-release data created by stress-induced
brittle fracture in a pure sapphire crystal at close to zero temperature where
stochastic fluctuations are minimal. The waiting-time distribution follows that
observed for fracture in rock and for earthquakes. Despite strong time
correlations of the events and the presence of large-event precursors, simple
prediction algorithms only succeed in a very weak probabilistic sense. We also
discuss prospects for further cryogenic experiments reaching close to
single-bond sensitivity and able to investigate the existence of a
transition-stress regime.


title: High energy QCD beyond the mean field approximation

abstract:
  It has been recently understood how to deal with high-energy scattering
beyond the mean field approximation. We review some of the main steps of this
theoretical progress, like the role of Lorentz invariance and unitarity
requirements, the importance of discreteness and fluctuations of gluon numbers
(Pomeron loops), the high-energy QCD/statistical physics correspondence and the
consequences for the saturation scale, the scattering amplitude and other, also
measurable, quantities.


title: Bifurcation in electrostatic resistive drift wave turbulence

abstract:
  The Hasegawa-Wakatani equations, coupling plasma density and electrostatic
potential through an approximation to the physics of parallel electron motions,
are a simple model that describes resistive drift wave turbulence. We present
numerical analyses of bifurcation phenomena in the model that provide new
insights into the interactions between turbulence and zonal flows in the
tokamak plasma edge region. The simulation results show a regime where, after
an initial transient, drift wave turbulence is suppressed through zonal flow
generation. As a parameter controlling the strength of the turbulence is tuned,
this zonal flow dominated state is rapidly destroyed and a turbulence-dominated
state re-emerges. The transition is explained in terms of the Kelvin-Helmholtz
stability of zonal flows. This is the first observation of an upshift of
turbulence onset in the resistive drift wave system, which is analogous to the
well-known Dimits shift in turbulence driven by ion temperature gradients.


title:
Coupling hidden Markov models for the discovery of Cis-regulatory
  modules in multiple species

abstract:
  Cis-regulatory modules (CRMs) composed of multiple transcription factor
binding sites (TFBSs) control gene expression in eukaryotic genomes.
Comparative genomic studies have shown that these regulatory elements are more
conserved across species due to evolutionary constraints. We propose a
statistical method to combine module structure and cross-species orthology in
de novo motif discovery. We use a hidden Markov model (HMM) to capture the
module structure in each species and couple these HMMs through multiple-species
alignment. Evolutionary models are incorporated to consider correlated
structures among aligned sequence positions across different species. Based on
our model, we develop a Markov chain Monte Carlo approach, MultiModule, to
discover CRMs and their component motifs simultaneously in groups of
orthologous sequences from multiple species. Our method is tested on both
simulated and biological data sets in mammals and Drosophila, where significant
improvement over other motif and module discovery methods is observed.


title: The Phenomenology of Elastic Energy Loss

abstract:
  The unexpectedly strong suppression of high p_T heavy-quarks in heavy-ion
collisions has given rise to the idea that partons propagating through a medium
in addition to energy loss by induced radiation also undergo substantial energy
loss due to elastic collisions. However, the precise magnitude of this elastic
energy loss component is highly controversial. While it is for a parton inside
a medium surprisingly difficult to define the difference between elastic and
radiative processes rigorously, the main phenomenological difference is in the
dependence of energy loss on in-medium pathlength: in a constant medium
radiative energy loss is expected to grow quadratically with pathlength,
elastic energy loss linearly. In this paper, we investigate a class of energy
loss models with such a linear pathlength dependence and demonstrate that they
are incompatible with measured data on hard hadronic back-to-back correlations
where a substantial variation of pathlength is probed. This indicates that any
elastic energy loss component has to be small.


title: Power-law running of the effective gluon mass

abstract:
  The dynamically generated effective gluon mass is known to depend
non-trivially on the momentum, decreasing sufficiently fast in the deep
ultraviolet, in order for the renormalizability of QCD to be preserved. General
arguments based on the analogy with the constituent quark masses, as well as
explicit calculations using the operator-product expansion, suggest that the
gluon mass falls off as the inverse square of the momentum, relating it to the
gauge-invariant gluon condensate of dimension four. In this article we
demonstrate that the power-law running of the effective gluon mass is indeed
dynamically realized at the level of the non-perturbative Schwinger-Dyson
equation. We study a gauge-invariant non-linear integral equation involving the
gluon self-energy, and establish the conditions necessary for the existence of
infrared finite solutions, described in terms of a momentum-dependent gluon
mass. Assuming a simplified form for the gluon propagator, we derive a
secondary integral equation that controls the running of the mass in the deep
ultraviolet. Depending on the values chosen for certain parameters entering
into the Ansatz for the fully-dressed three-gluon vertex, this latter equation
yields either logarithmic solutions, familiar from previous linear studies, or
a new type of solutions, displaying power-law running. In addition, it
furnishes a non-trivial integral constraint, which restricts significantly (but
does not determine fully) the running of the mass in the intermediate and
infrared regimes. The numerical analysis presented is in complete agreement
with the analytic results obtained, showing clearly the appearance of the two
types of momentum-dependence, well-separated in the relevant space of
parameters. Open issues and future directions are briefly discussed.


title: Non-Gaussianities from ekpyrotic collapse with multiple fields

abstract:
  We compute the non-Gaussianity of the curvature perturbation generated by
ekpyrotic collapse with multiple fields. The transition from the multi-field
scaling solution to a single-field dominated regime converts initial
isocurvature field perturbations to an almost scale-invariant comoving
curvature perturbation. In the specific model of two fields, $\phi_1$ and
$\phi_2$, with exponential potentials, $-V_i \exp (-c_i \phi_i)$, we calculate
the bispectrum of the resulting curvature perturbation. We find that the
non-Gaussianity is dominated by non-linear evolution on super-Hubble scales and
hence is of the local form. The non-linear parameter of the curvature
perturbation is given by $f_{NL} = 5 c_j^2 /12$, where $c_j$ is the exponent of
the potential for the field which becomes sub-dominant at late times. Since
$c_j^2$ must be large, in order to generate an almost scale invariant spectrum,
the non-Gaussianity is inevitably large. By combining the present observational
constraints on $f_{\rm NL}$ and the scalar spectral index, the specific model
studied in this paper is thus ruled out by current observational data.


title: On the behaviour of R(pA) at high energy

abstract:
  We discuss the behaviour of R(pA), the ratio of the unintegrated gluon
distribution of a nucleus over the unintegrated gluon distribution of a proton
scaled up by A^{1/3}, at high energy and fixed coupling. We show that R(pA)
exhibits a rising gluon shadowing with growing rapidity, approaching 1/A^{1/3}
at asymptotic rapidity, which means total gluon shadowing due to gluon number
fluctuations or Pomeron loops.


title:
Phase diagram analysis and crystal growth of solid solutions
  Ca_{1-x}Sr_xF_2

abstract:
  The binary phase diagram CaF$_2$--SrF$_2$ was investigated by differential
thermal analysis (DTA). Both substances exhibit unlimited mutual solubility
with an azeotropic point showing a minimum melting temperature of
T_\mathrm{min}=1373^{\circ}$C for the composition
Ca$_{0.582}$Sr$_{0.418}$F$_2$. Close to this composition, homogeneous single
crystals up to 30 mm diameter without remarkable segregation could be grown by
the Czochralski method.


title:
Sensitivity Analysis of the Orthoglide, a 3-DOF Translational Parallel
  Kinematic Machine

abstract:
  This paper presents a sensitivity analysis of the Orthoglide, a 3-DOF
translational Parallel Kinematic Machine. Two complementary methods are
developed to analyze its sensitivity to its dimensional and angular variations.
First, a linkage kinematic analysis method is used to have a rough idea of the
influence of the dimensional variations on the location of the end-effector.
Besides, this method shows that variations in the design parameters of the same
type from one leg to the other have the same influence on the end-effector.
However, this method does not take into account the variations in the
parallelograms. Thus, a differential vector method is used to study the
influence of the dimensional and angular variations in the parts of the
manipulator on the position and orientation of the end-effector, and
particularly the influence of the variations in the parallelograms. It turns
out that the kinematic isotropic configuration of the manipulator is the least
sensitive one to its dimensional and angular variations. On the contrary, the
closest configurations to its kinematic singular configurations are the most
sensitive ones to geometrical variations.


title: Instantons and the \theta vacuum in non-linear \sigma model and QCD

abstract:
  This is a talk given on the $\theta $vacuum and cluster properties and the
non-linear sigma model proposed to be given on occasion of an invitation to the
seventh international conference on Symmetry in Nonlinear Physics,June 24 - 30,
2007, Kiev.


title: The Tensor Part of the Skyrme Energy Density Functional

abstract:
  We systematically study the effect of the J^2 tensor terms in the Skyrme
energy functional on properties of spherical nuclei. We build a set of 36
parameterizations covering a wide range of the corresponding parameter space.
We analyze the impact of the tensor terms on the evolution of
single-particle-level splittings along chains of semi-magic nuclei in spherical
calculations. We find that positive values of the coupling constants of
proton-neutron and like-particle tensor terms allow for a qualitative
description of the evolution of neutron and proton single-particle level
splittings in chains of Ca, Ni and Sn isotopes.


title: Group cocycles and the ring of affiliated operators

abstract:
  In this article we study cocycles of discrete countable groups with values in
l^2(G) and the ring of affiliated operators UG. We clarify properties of the
first cohomology of a group G with coefficients in l^2(G) and answer several
questions from [CTV]. Moreover, we obtain strong results about the existence of
free subgroups and the subgroup structure, provided the group has a positive
first l^2-Betti number. We give numerous applications and examples of groups
which satisfy our assumptions.


title: Dualities Between Entropy Functions and Network Codes

abstract:
  This paper provides a new duality between entropy functions and network
codes. Given a function $g\geq 0$ defined on all proper subsets of $N$ random
variables, we provide a construction for a network multicast problem which is
solvable if and only if $g$ is entropic. The underlying network topology is
fixed and the multicast problem depends on $g$ only through edge capacities and
source rates. Relaxing the requirement that the domain of $g$ be subsets of
random variables, we obtain a similar duality between polymatroids and the
linear programming bound. These duality results provide an alternative proof of
the insufficiency of linear (and abelian) network codes, and demonstrate the
utility of non-Shannon inequalities to tighten outer bounds on network coding
capacity regions.


title:
Detailed Analysis of Balmer Lines in a Sloan Digital Sky Survey Sample
  of 90 Broad Line Active Galactic Nuclei

abstract:
  In order to contribute to the general effort aiming at the improvement of our
knowledge about the physical conditions within the Broad Line Region (BLR) of
Active Galactic Nuclei (AGN), here we present the results achieved by our
analysis of the spectral properties of a sample of 90 broad line emitting
sources, collected at the Sloan Digital Sky Survey (SDSS) database. By focusing
our attention mainly onto the Balmer series of hydrogen emission lines, which
is the dominant feature in the optical wavelength range of many BLR spectra, we
extracted several flux and profile measurements, which we related to other
source properties, such as optical continuum luminosities, inferred black hole
masses, and accretion rates. Using the Boltzmann Plot method to investigate the
Balmer line flux ratios as a function of the line profiles, we found that
broader line emitting AGN typically have larger H_alpha / H_beta and smaller
H_gamma / H_beta and H_delta / H_beta line ratios. With the help of some recent
investigations, we model the structure of the BLR and we study the influence of
the accretion process on the properties of the BLR plasma.


title:
Radio morphology and spectral analysis of cD galaxies in rich and poor
  galaxy clusters

abstract:
  We present a radio morphological study and spectral analysis for a sample of
13 cD galaxies in rich and poor clusters of galaxies.} Our study is based on
new high sensitivity Giant Metrewave Radio Telescope (GMRT) observations at
1.28 GHz, 610 MHz and 235 MHz, and on archival data. From a statistical sample
of cluster cD galaxies we selected those sources with little information
available in the literature and promising for the detection of aged radio
emission. Beyond the high sensitivity images for all 13 radio galaxies, we
present also a detailed spectral analysis for 7 of them. We found a variety of
morphologies and linear sizes, as typical for radio galaxies in the radio power
range sampled here (low to intermediate power radio galaxies). The spectral
analysis shows that 10/13 radio galaxies have steep radio spectrum, with
spectral index $\alpha \ge 1$. In general, the radiative ages and growth
velocities are consistent with previous findings that the evolution of radio
galaxies at the cluster centres is affected by the dense external medium (i.e.
low growth velocities and old ages. We suggest that the dominant galaxies in A
2622 and MKW 03s are dying radio sources, which at present are not fed by
nuclear activity. On the other hand, the spectacular source at the centre of A
2372 might be a very interesting example of restarted radio galaxy. For this
source we estimated a life cycle of the order of 10$^6$ yr.


title: Structure and finiteness properties of subdirect products of groups

abstract:
  We investigate the structure of subdirect products of groups, particularly
their finiteness properties. We pay special attention to the subdirect products
of free groups, surface groups and HNN extensions. We prove that a finitely
presented subdirect product of free and surface groups virtually contains a
term of the lower central series of the direct product or else fails to
intersect one of the direct summands. This leads to a characterization of the
finitely presented subgroups of the direct product of 3 free or surface groups,
and to a solution to the conjugacy problem for arbitrary finitely presented
subgroups of direct products of surface groups. We obtain a formula for the
first homology of a subdirect product of two free groups and use it to show
there is no algorithm to determine the first homology of a finitely generated
subgroup.