title:
Optical structure and function of the white filamentary hair covering
  the edelweiss bracts

abstract:
  The optical properties of the inflorescence of the high-altitude
''Leontopodium nivale'' subsp. ''alpinum'' (edelweiss) is investigated, in
relation with its submicrometer structure, as determined by scanning electron
microscopy. The filaments forming the hair layer have been found to exhibit an
internal structure which may be one of the few examples of a photonic structure
found in a plant. Measurements of light transmission through a self-supported
layer of hair pads taken from the bracts supports the idea that the wooly layer
covering the plant absorbs near-ultraviolet radiation before it reaches the
cellular tissue. Calculations based on a photonic-crystal model provides
insight on the way radiation can be absorbed by the filamentary threads.


title: Time Machine at the LHC

abstract:
  Recently, black hole and brane production at CERN's Large Hadron Collider
(LHC) has been widely discussed. We suggest that there is a possibility to test
causality at the LHC. We argue that if the scale of quantum gravity is of the
order of few TeVs, proton-proton collisions at the LHC could lead to the
formation of time machines (spacetime regions with closed timelike curves)
which violate causality. One model for the time machine is a traversable
wormhole. We argue that the traversable wormhole production cross section at
the LHC is of the same order as the cross section for the black hole
production. Traversable wormholes assume violation of the null energy condition
(NEC) and an exotic matter similar to the dark energy is required. Decay of the
wormholes/time machines and signatures of time machine events at the LHC are
discussed.


title:
Ly Alpha-Emitting Galaxies at z=3.1: L* Progenitors Experiencing Rapid
  Star Formation

abstract:
  We studied the clustering properties and multiwavelength spectral energy
distributions of a complete sample of 162 Ly Alpha-Emitting (LAE) galaxies at
z=3.1 discovered in deep narrow-band MUSYC imaging of the Extended Chandra Deep
Field South. LAEs were selected to have observed frame equivalent widths >80A
and emission line fluxes >1.5E-17 erg/cm^2/s. Only 1% of our LAE sample appears
to host AGN. The LAEs exhibit a moderate spatial correlation length of
r_0=3.6+0.8-1.0 Mpc, corresponding to a bias factor b=1.7+0.3-0.4, which
implies median dark matter halo masses of log10(M_med) = 10.9+0.5-0.9 M_sun.
Comparing the number density of LAEs, (1.5+-0.3)E-3/Mpc^3, with the number
density of these halos finds a mean halo occupation ~1-10%. The evolution of
galaxy bias with redshift implies that most z=3.1 LAEs evolve into present-day
galaxies with L<2.5L*, whereas other z>3 galaxy populations typically evolve
into more massive galaxies. Halo merger trees show that z=0 descendants occupy
halos with a wide range of masses, with a median descendant mass close to that
of L*. Only 30% of LAEs have sufficient stellar mass (>~3E9 M_sun) to yield
detections in deep Spitzer-IRAC imaging. A two-population SED fit to the
stacked UBVRIzJK+[3.6,4.5,5.6,8.0]micron fluxes of the IRAC-undetected objects
finds that the typical LAE has low stellar mass (1.0+0.6-0.4 E9 M_sun),
moderate star formation rate (2+-1 M_sun/yr), a young component age of 20+30-10
Myr, and little dust (A_V<0.2). The best fit model has 20% of the mass in the
young stellar component, but models without evolved stars are also allowed.


title:
Photon storage in Lambda-type optically dense atomic media. IV. Optimal
  control using gradient ascent

abstract:
  We use the numerical gradient ascent method from optimal control theory to
extend efficient photon storage in Lambda-type media to previously inaccessible
regimes and to provide simple intuitive explanations for our optimization
techniques. In particular, by using gradient ascent to shape classical control
pulses used to mediate photon storage, we open up the possibility of high
efficiency photon storage in the non-adiabatic limit, in which analytical
solutions to the equations of motion do not exist. This control shaping
technique enables an order-of-magnitude increase in the bandwidth of the
memory. We also demonstrate that the often discussed connection between time
reversal and optimality in photon storage follows naturally from gradient
ascent. Finally, we discuss the optimization of controlled reversible
inhomogeneous broadening.


title: Lower bounds for warping functions on warped-product AHE manifolds

abstract:
  Let $[\gamma]$ be the conformal boundary of a warped product $C^{3,\alpha}$
AHE metric $g=g_M+u^2h$ on $N=M \times F$, where $(F,h)$ is compact with unit
volume and nonpositive curvature. We show that if $[\gamma]$ has positive
Yamabe constant, then $u$ has a positive lower bound that depends only on
$[\gamma]$.


title: Percolative Effects on Noise in Pentacene Transistors

abstract:
  The 1/f noise in pentacene thin film transistors has been measured as a
function of device thickness from well above the effective conduction channel
thickness to only two conducting layers. Over the entire thickness range, the
spectral noise form is 1/f, and the noise parameter varies as (gate voltage)-1,
confirming that the noise is due to mobility fluctuations, even in the thinnest
films. Hooge's parameter varies as an inverse power-law with conductivity for
all film thicknesses. The magnitude and transport characteristics of the
spectral noise are well explained in terms of percolative effects arising from
the grain boundary structure.


title: Chaotic quantum dots with strongly correlated electrons

abstract:
  Quantum dots pose a problem where one must confront three obstacles:
randomness, interactions and finite size. Yet it is this confluence that allows
one to make some theoretical advances by invoking three theoretical tools:
Random Matrix theory (RMT), the Renormalization Group (RG) and the 1/N
expansion. Here the reader is introduced to these techniques and shown how they
may be combined to answer a set of questions pertaining to quantum dots


title:
Blob formation and acceleration in the solar wind: role of converging
  flows and viscosity

abstract:
  The effect of viscosity and of converging flows on the formation of blobs in
the slow solar wind is analysed by means of resistive MHD simulations. The
regions above coronal streamers where blobs are formed (Sheeley et al., 1997)
are simulated using a model previously proposed by Einaudi et al. (1999). The
result of our investigation is twofold. First, we demonstrate a new mechanism
for enhanced momentum transfer between a forming blob and the fast solar wind
surrounding it. The effect is caused by the longer range of the electric field
caused by the tearing instability forming the blob. The electric field reaches
into the fast solar wind and interacts with it, causing a viscous drag that is
global in nature rather than local across fluid layers as it is the case in
normal uncharged fluids (like water). Second, the presence of a magnetic cusp
at the tip of a coronal helmet streamer causes a converging of the flows on the
two sides of the streamer and a direct push of the forming island by the fast
solar wind, resulting in a more efficient momentum exchange.


title: Monte Carlo study of two-dimensional Bose-Hubbard model

abstract:
  One of the most promising applications of ultracold gases in optical lattices
is the possibility to use them as quantum emulators of more complex condensed
matter systems. We provide benchmark calculations, based on exact quantum Monte
Carlo simulations, for the emulator to be tested against. We report results for
the ground state phase diagram of the two-dimensional Bose-Hubbard model at
unity filling factor. We precisely trace out the critical behavior of the
system and resolve the region of small insulating gaps, \Delta << J. The
critical point is found to be (J/U)_c=0.05974(3), in perfect agreement with the
high-order strong-coupling expansion method of Ref. 1. In addition, we present
data for the effective mass of particle and hole excitations inside the
insulating phase and obtain the critical temperature for the superfluid-normal
transition at unity filling factor.


title: Low regularity solutions of two fifth-order KdV type equations

abstract:
  The Kawahara and modified Kawahara equations are fifth-order KdV type
equations and have been derived to model many physical phenomena such as
gravity-capillary waves and magneto-sound propagation in plasmas. This paper
establishes the local well-posedness of the initial-value problem for Kawahara
equation in $H^s({\mathbf R})$ with $s>-\frac74$ and the local well-posedness
for the modified Kawahara equation in $H^s({\mathbf R})$ with $s\ge-\frac14$.
To prove these results, we derive a fundamental estimate on dyadic blocks for
the Kawahara equation through the $[k; Z]$ multiplier norm method of Tao
\cite{Tao2001} and use this to obtain new bilinear and trilinear estimates in
suitable Bourgain spaces.


title: Fingerprinting with Minimum Distance Decoding

abstract:
  This work adopts an information theoretic framework for the design of
collusion-resistant coding/decoding schemes for digital fingerprinting. More
specifically, the minimum distance decision rule is used to identify 1 out of t
pirates. Achievable rates, under this detection rule, are characterized in two
distinct scenarios. First, we consider the averaging attack where a random
coding argument is used to show that the rate 1/2 is achievable with t=2
pirates. Our study is then extended to the general case of arbitrary $t$
highlighting the underlying complexity-performance tradeoff. Overall, these
results establish the significant performance gains offered by minimum distance
decoding as compared to other approaches based on orthogonal codes and
correlation detectors. In the second scenario, we characterize the achievable
rates, with minimum distance decoding, under any collusion attack that
satisfies the marking assumption. For t=2 pirates, we show that the rate
$1-H(0.25)\approx 0.188$ is achievable using an ensemble of random linear
codes. For $t\geq 3$, the existence of a non-resolvable collusion attack, with
minimum distance decoding, for any non-zero rate is established. Inspired by
our theoretical analysis, we then construct coding/decoding schemes for
fingerprinting based on the celebrated Belief-Propagation framework. Using an
explicit repeat-accumulate code, we obtain a vanishingly small probability of
misidentification at rate 1/3 under averaging attack with t=2. For collusion
attacks which satisfy the marking assumption, we use a more sophisticated
accumulate repeat accumulate code to obtain a vanishingly small
misidentification probability at rate 1/9 with t=2. These results represent a
marked improvement over the best available designs in the literature.


title:
Kawamata-Viehweg Vanishing on Rational Surfaces in Positive
  Characteristic

abstract:
  We prove that the Kawamata-Viehweg vanishing theorem holds on rational
surfaces in positive characteristic by means of the lifting property to W_2(k)
of certain log pairs on smooth rational surfaces. As a corollary, the
Kawamata-Viehweg vanishing theorem holds on log del Pezzo surfaces in positive
characteristic.


title: The Polyakov Loop and the Eigenvalues of the Dirac Operator

abstract:
  Aiming at the link between confinement and chiral symmetry the Polyakov loop
represented as a spectral sum of eigenvalues of the Dirac operator was subject
of recent studies. We analyze the volume dependence as well as the continuum
behavior of this quantity for quenched QCD using staggered fermions.
Furthermore, we present first results using dynamical configurations.


title: Hodge-theoretic aspects of the Decomposition Theorem

abstract:
  Given a projective morphism of compact, complex, algebraic varieties and a
relatively ample line bundle on the domain we prove that a suitable choice,
dictated by the line bundle, of the decomposition isomorphism of the
Decomposition Theorem of Beilinson, Bernstein, Deligne and Gabber, yields
isomorphisms of pure Hodge structures. The proof is based on a new
cohomological characterization of the decomposition isomorphism associated with
the line bundle. We prove some corollaries concerning the intersection form in
intersection cohomology, the natural map from cohomology to intersection
cohomology, projectors and Hodge cycles, and induced morphisms in intersection
cohomology.


title: Dynamical black holes with symmetry in Einstein-Gauss-Bonnet gravity

abstract:
  We explore various aspects of dynamical black holes defined by a future outer
trapping horizon in $n(\ge 5)$-dimensional Einstein-Gauss-Bonnet gravity. In
the present paper, we assume that the spacetime has symmetries corresponding to
the isometries of an $(n-2)$-dimensional maximally symmetric space and the
Gauss-Bonnet coupling constant is non-negative. Depending on the existence or
absence of the general relativistic limit, solutions are classified into GR and
non-GR branches, respectively. Assuming the null energy condition on matter
fields, we show that a future outer trapping horizon in the GR branch possesses
the same properties as that in general relativity. In contrast, that in the
non-GR branch is shown to be non-spacelike with its area non-increasing into
the future. We can recognize this peculiar behavior to arise from a fact that
the null energy condition necessarily leads to the null convergence condition
for radial null vectors in the GR branch, but not in the non-GR branch. The
energy balance law yields the first law of a trapping horizon, from which we
can read off the entropy of a trapping horizon reproducing Iyer-Wald's
expression. The entropy of a future outer trapping horizon is shown to be
non-decreasing in both branches along its generator.


title: Fluctuation-dissipation theorem for thermo-refractive noise

abstract:
  We introduce a simple prescription for calculating the spectra of thermal
fluctuations of temperature-dependent quantities of the form $\hat{\delta
T}(t)=\int d^3\vec{r} \delta T(\vec{r},t) q(\vec{r})$. Here $T(\vec{r}, t)$ is
the local temperature at location $\vec{r}$ and time $t$, and $q(\vec{r})$ is
an arbitrary function. As an example of a possible application, we compute the
spectrum of thermo-refractive coating noise in LIGO, and find a complete
agreement with the previous calculation of Braginsky, Gorodetsky and
Vyatchanin. Our method has computational advantage, especially for non-regular
or non-symmetric geometries, and for the cases where $q(\vec{r})$ is
non-negligible in a significant fraction of the total volume.


title:
High photo-excited carrier multiplication by charged InAs dots in
  AlAs/GaAs/AlAs resonant tunneling diode

abstract:
  We present an approach for the highly sensitive photon detection based on the
quantum dots (QDs) operating at temperature of 77K. The detection structure is
based on an AlAs/GaAs/AlAs double barrier resonant tunneling diode combined
with a layer of self-assembled InAs QDs (QD-RTD). A photon rate of 115 photons
per second had induced 10nA photocurrent in this structure, corresponding to
the photo-excited carrier multiplication factor of 10^7. This high
multiplication factor is achieved by the quantum dot induced memory effect and
the resonant tunneling tuning effect of QD-RTD structure.


title: The structures of standard (g,K)-modules of SL(3,R)

abstract:
  We describe explicitely the structures of standard $(g,K)$-modules of
$SL(3,R)$.


title:
Leptonic CP Violation Induced by Approximately mu-tau Symmetric Seesaw
  Mechanism

abstract:
  Assuming a minimal seesaw model with two heavy neutrinos (N), we examine
effects of leptonic CP violation induced by approximate mu-tau symmetric
interactions. As long as N is subject to the mu-tau symmetry, we can choose CP
phases of Dirac mass terms without loss of generality in such a way that these
phases arise from mu-tau symmetry breaking interactions. In the case that no
phase is present in heavy neutrino mass terms, leptonic CP phases are
controlled by two phases alpha and beta. The similar consideration is extended
to N blind to the mu-tau symmetry. It is argued that N subject (blind) to the
mu-tau symmetry necessarily describes the normal (inverted) mass hierarchy. We
restrict ourselves to mu-tau symmetric textures giving the tri-bimaximal mixing
and calculate flavor neutrino masses to estimate CP-violating Dirac and
Majorana phases as well as neutrino mixing angles as functions of alpha and
beta. Since alpha and beta are generated by mu-tau symmetry breaking
interactions, CP-violating Majorana phase tends to be suppressed and is found
to be at most O(0.1) radian. On the other hand, CP-violating Dirac phase tends
to show a proportionality to alpha or to beta.


title:
On the Brink of Major Discoveries in Weak Charm Decays -- a Bismarckian
  Chance to Make History

abstract:
  The recently obtained strong evidence for $D^0 - \bar D^0$ oscillations from
the $B$ factories provides an important benchmark in our search for New Physics
in charm transitions. While the theoretical verdict on the observed values of
$x_D$ and $y_D$ is ambiguous -- they could be fully generated by SM dynamics,
yet could contain also a sizable contribution from New Physics -- such
oscillations provide a new stage for \cp violation driven by New Physics. After
emphasizing the unique role of charm among up-type quarks, I describe in some
detail the \cp phenomenology for charm decays.


title: Off-shell dimensional reduction of 5D orbifold supergravity

abstract:
  We present a systematic way for deriving a four-dimensional (4D) effective
action of the five-dimensional (5D) orbifold supergravity respecting the N=1
{\it off-shell} structure. As an illustrating example, we derive a 4D effective
theory of the 5D gauged supergravity with a universal hypermultiplet and {\it
generic} gaugings, which includes the 5D heterotic M-theory and the
supersymmetric Randall-Sundrum model as special limits of the gauging
parameters. We show the vacuum structure of such model, especially the nature
of moduli stabilization, introducing perturbative superpotential terms at the
orbifold fixed points.


title: Cost and Effects of Pinning Control for Network Synchronization

abstract:
  In this paper, the problem of pinning control for synchronization of complex
dynamical networks is discussed. A cost function of the controlled network is
defined by the feedback gain and the coupling strength of the network. An
interesting result is that lower cost is achieved by the control scheme of
pinning nodes with smaller degrees. Some rigorous mathematical analysis is
presented for achieving lower cost in the synchronization of different
star-shaped networks. Numerical simulations on some non-regular complex
networks generated by the Barabasi-Albert model and various star-shaped
networks are shown for verification and illustration.


title: Probing Nonequilibrium Fluctuations through Linear Response

abstract:
  Linear response analysis in the nonequilibrium steady state (Gaussian regime)
provides two independent fluctuation-response relations. One, in the form of
the symmetric matrix, manifests the departure from the equilibrium formula
through the quantity so-called {\it irreversible circulation}. The other, in
the anti-symmetric form, connects the asymmetries in the fluctuation and the
response function. These formulas represent characteristic features of
fluctuations far from equilibrium, which have no counterparts in thermal
equilibrium.


title: Stochastic resonance in a single electron turnstile

abstract:
  In this paper, we report stochastic resonance (SR) in a single electron
turnstile. It has been known that SR emerges by the cooperation of a weak
periodic signal and noise in a bistable system. A periodic signal produces
switching between two stable states by lowering the potential barrier. Even if
the amplitude of the signal is not large enough to make the potential barrier
disappear, the switching can occur with the help of noise. As a result, an
output signal-to-noise ratio (SNR), which shows how much the switching is
synchronized with the signal, can be enhanced by increasing the noise. We have
formulated the SR in a single electron turnstile into the adiabatic two-state
theory of McNamara-Wiesenfeld and confirmed its manifestation by numerical
simulation. These results could be applied to detection of the periodic motion
of very small electric charge under noisy environment.


title: Branes on Poisson varieties

abstract:
  We first extend the notion of connection in the context of Courant algebroids
to obtain a new characterization of generalized Kaehler geometry. We then
establish a new notion of isomorphism between holomorphic Poisson manifolds,
which is non-holomorphic in nature. Finally we show an equivalence between
certain configurations of branes on Poisson varieties and generalized Kaehler
structures, and use this to construct explicitly new families of generalized
Kaehler structures on compact holomorphic Poisson manifolds equipped with
positive Poisson line bundles (e.g. Fano manifolds). We end with some
speculations concerning the connection to non-commutative algebraic geometry.


title: Schubert Polynomials for the affine Grassmannian of the symplectic group

abstract:
  We study the Schubert calculus of the affine Grassmannian Gr of the
symplectic group. The integral homology and cohomology rings of Gr are
identified with dual Hopf algebras of symmetric functions, defined in terms of
Schur's P and Q-functions. An explicit combinatorial description is obtained
for the Schubert basis of the cohomology of Gr, and this is extended to a
definition of the affine type C Stanley symmetric functions. A homology Pieri
rule is also given for the product of a special Schubert class with an
arbitrary one.


title:
Large nonlinear absorption and refraction coefficients of carbon
  nanotubes estimated from femtosecond Z-scan measurements

abstract:
  Nonlinear transmission of 80 and 140 femtosecond pulsed light with $0.79 \mu
m$ wavelength through single walled carbon nanotubes suspended in water
containing sodium dodecyl sulphate is studied. Pulse-width independent
saturation absorption and negative cubic nonlinearity are observed,
respectively, in open and closed aperture Z-scan experiments. The theoretical
expressions derived to analyze the z-dependent transmission in the saturable
limit require two photon absorption coefficient $\beta_0\sim$ $1.4 cm/MW$ and a
nonlinear index $\gamma \sim -5.5 \times10^{-11} cm^2/W$ to fit the data.


title: The 2006 Radio Outburst of a Microquasar Cyg X-3: Observation and Data

abstract:
  We present the results of the multi-frequency observations of radio outburst
of the microquasar Cyg X-3 in February and March 2006 with the Nobeyama 45-m
telescope, the Nobeyama Millimeter Array, and the Yamaguchi 32-m telescope.
Since the prediction of a flare by RATAN-600, the source has been monitored
from Jan 27 (UT) with these radio telescopes. At the eighteenth day after the
quench of the activity, successive flares exceeding 1 Jy were observed
successfully. The time scale of the variability in the active phase is
presumably shorter in higher frequency bands.
  We also present the result of a follow-up VLBI observation at 8.4 GHz with
the Japanese VLBI Network (JVN) 2.6 days after the first rise. The VLBI image
exhibits a single core with a size of <8 mas (80 AU). The observed image was
almost stable, although the core showed rapid variation in flux density. No jet
structure was seen at a sensitivity of $T_b = 7.5\times 10^5$ K.


title: Boundary conditions for Dirac fermions on a terminated honeycomb lattice

abstract:
  We derive the boundary condition for the Dirac equation corresponding to a
tight-binding model on a two-dimensional honeycomb lattice terminated along an
arbitary direction. Zigzag boundary conditions result generically once the
boundary is not parallel to the bonds. Since a honeycomb strip with zigzag
edges is gapless, this implies that confinement by lattice termination does not
in general produce an insulating nanoribbon. We consider the opening of a gap
in a graphene nanoribbon by a staggered potential at the edge and derive the
corresponding boundary condition for the Dirac equation. We analyze the edge
states in a nanoribbon for arbitrary boundary conditions and identify a class
of propagating edge states that complement the known localized edge states at a
zigzag boundary.


title: General Solution of the Quantum Damped Harmonic Oscillator

abstract:
  In this paper the general solution of the quantum damped harmonic oscillator
is given.


title: A moduli scheme of embedded curve singularities

abstract:
  The main purpose of this paper is to prove the existence of the moduli space
parameterizing the embedded curve singularities of $(k^N,0)$ with an admissible
Hilbert polynomial and to study its basic properties.


title: Log Structures on Generalized Semi-Stable Varieties

abstract:
  This is my PhD Thesis, part of it has published in Acta Mathematica Sinica.
In this paper, a class of morphisms which have a kind of singularity weaker
than normal crossing is considered. We construct the obstruction such that the
so-called semi-stable log structures exists if and only if the obstruction
vanishes. In the case of no power, if the obstruction vanishes, then the
semi-stable log structure is unique up to a unique isomorphism. So we obtain a
kind of canonical structures on this family of morphisms.


title: Effect of contact induced states on minimum conductivity in graphene

abstract:
  The objective of this paper is to point out that contact induced states can
help explain the structure dependence of the minimum conductivity observed
experimentally even if the samples were purely ballistic. Contact induced
states are similar to the well-known metal induced gap states (MIGS) in
metal-semiconductor Schottky junctions, which typically penetrate only a few
atomic lengths into the semiconductor, while the depth of penetration decreases
with increasing band gap. However, in graphene we find that these states
penetrate a much longer distance of the order of the width of the contacts. As
a result, ballistic graphene samples with a length less than their width can
exhibit a resistance proportional to length that is not Ohmic in origin, but
arises from a reduced role of contact-induced states. While actual samples are
probably not ballistic and involve scattering processes, our results show that
these contact induced effects need to be taken into account in interpreting
experiments and minimum conductivity depends strongly on the structure and
configuration (two- vs. four-terminal) used.


title: Primes in Tuples II

abstract:
  We prove that there are infinitely often pairs of primes much closer than the
average spacing between primes - almost within the square root of the average
spacing. We actually prove a more general result concerning the set of values
taken on by the differences between primes.


title:
Light localization signatures in backscattering from periodic disordered
  media

abstract:
  The backscattering line shape is analytically predicted for thick disordered
medium films where, remarkably, the medium configuration is periodic along the
direction perpendicular to the incident light. A blunt triangular peak is found
to emerge on the sharp top. The phenomenon roots in the coexistence of quasi-1D
localization and 2D extended states.


title: Lattice simulation of 2+1 flavors of overlap light quarks

abstract:
  We report on the status of the dynamical overlap QCD simulation project by
the JLQCD collaboration. After completing two-flavor QCD simulation on a
16^3x32 lattice at lattice spacing a 0.12 fm, we started a series of runs with
2+1 flavors. In this report, we describe an outline of our algorithms,
parameter choices, and some early physics results of this second phase of our
project.


title:
Group Analysis of Variable Coefficient Diffusion-Convection Equations.
  I. Enhanced Group Classification

abstract:
  We discuss the classical statement of group classification problem and some
its extensions in the general case. After that, we carry out the complete
extended group classification for a class of (1+1)-dimensional nonlinear
diffusion--convection equations with coefficients depending on the space
variable. At first, we construct the usual equivalence group and the extended
one including transformations which are nonlocal with respect to arbitrary
elements. The extended equivalence group has interesting structure since it
contains a non-trivial subgroup of non-local gauge equivalence transformations.
The complete group classification of the class under consideration is carried
out with respect to the extended equivalence group and with respect to the set
of all point transformations. Usage of extended equivalence and correct choice
of gauges of arbitrary elements play the major role for simple and clear
formulation of the final results. The set of admissible transformations of this
class is preliminary investigated.


title: Probabilistic communication complexity over the reals

abstract:
  Deterministic and probabilistic communication protocols are introduced in
which parties can exchange the values of polynomials (rather than bits in the
usual setting). It is established a sharp lower bound $2n$ on the communication
complexity of recognizing the $2n$-dimensional orthant, on the other hand the
probabilistic communication complexity of its recognizing does not exceed 4. A
polyhedron and a union of hyperplanes are constructed in $\RR^{2n}$ for which a
lower bound $n/2$ on the probabilistic communication complexity of recognizing
each is proved. As a consequence this bound holds also for the EMPTINESS and
the KNAPSACK problems.


title: Breakdown of Coherence ?

abstract:
  In a recent paper, Albrecht Kyrieleis, Jeff Forshaw and I discovered a new
tower of super-leading logarithms in gaps between jets cross sections. After
discussions with the referee of our paper and further investigation, we have
come to view this as a breakdown of naive coherence for initial state
radiation. In this talk I illustrate this statement in a simple way, and show
how it results in the super-leading logarithms.


title:
Quark Masses in Supersymmetric SU(3)color x SU(3)W x U(1)X Model with
  Discrete T' flavor symmetry

abstract:
  We propose a supersymmetric model of quark flavor symmetry based on
SU(3)colorxSU(3)WxU(1)X x T' where T' (binary tetrahedral group) is a discrete
flavor symmetry group. The third (heavy) generation of quarks are assigned to
singlet representation of T' while light quark generations are treated
differently and assigned to doublet representation of T' . The model generates
masses for heavy quarks as in 3-3-1 case. The quark mass terms for the second
generation are obtained when T' symmetry is broken at leading order and for
first generation with small higher order corrections .The flavor-changing
neutral current (FCNC) effects are suppressed at leading order for third to
second generation quark transitions due to T' breaking which is an attractive
feature of the 3-3-1 model with T' symmetry.


title:
Effects of polarisation on study of anomalous VVH interactions at a
  Linear Collider

abstract:
  We investigate the use of beam polarisation as well as final state $\tau$
polarisation effects in probing the interaction of the Higgs boson with a pair
of heavy vector bosons in the process $e^+ e^- \to f \bar f H$, where $f$ is
any light fermion. The sensitivity of the International Linear Collider (ILC)
operating at $\sqrt s=500$ GeV, to such $VVH$($V = W/Z$) couplings is examined
in a model independent way. The effects of ISR and beamstrahlung are discussed.


title:
L2 norm performance index of synchronization and optimal control
  synthesis of complex networks

abstract:
  In this paper, the synchronizability problem of dynamical networks is
addressed, where better synchronizability means that the network synchronizes
faster with lower-overshoot. The L2 norm of the error vector e is taken as a
performance index to measure this kind of synchronizability. For the
equilibrium synchronization case, it is shown that there is a close
relationship between the L2 norm of the error vector e and the H2 norm of the
transfer function G of the linearized network about the equilibrium point.
Consequently, the effect of the network coupling topology on the H2 norm of the
transfer function G is analyzed. Finally, an optimal controller is designed,
according to the so-called LQR problem in modern control theory, which can
drive the whole network to its equilibrium point and meanwhile minimize the L2
norm of the output of the linearized network.


title:
The history of mass assembly of faint red galaxies in 28 galaxy clusters
  since z=1.3

abstract:
  We measure the relative evolution of the number of bright and faint (as faint
as 0.05 L*) red galaxies in a sample of 28 clusters, of which 16 are at 0.50<=
z<=1.27, all observed through a pair of filters bracketing the 4000 Angstrom
break rest-frame. The abundance of red galaxies, relative to bright ones, is
constant over all the studied redshift range, 0<z<1.3, and rules out a
differential evolution between bright and faint red galaxies as large as
claimed in some past works. Faint red galaxies are largely assembled and in
place at z=1.3 and their deficit does not depend on cluster mass, parametrized
by velocity dispersion or X-ray luminosity. Our analysis, with respect to
previous one, samples a wider redshift range, minimizes systematics and put a
more attention to statistical issues, keeping at the same time a large number
of clusters.


title: CdZnTe room-temperature semiconductor operation in liquid scintillator

abstract:
  We demonstrate the first operation of CdZnTe room-temperature detectors in a
liquid scintillator environment. This work follows conceptually the
Heusser-type detector method of operating HPGe detectors in liquid nitrogen and
liquid argon but instead for a far more practical room-temperature ensemble
with the aim of achieving ultra-low background levels for radiation detection.


title: The look-ahead effect of phenotypic mutations

abstract:
  The evolution of complex molecular traits such as disulphide bridges often
requires multiple mutations. The intermediate steps in such evolutionary
trajectories are likely to be selectively neutral or deleterious. Therefore,
large populations and long times may be required to evolve such traits. We
propose that errors in transcription and translation may allow selection for
the intermediate mutations if the final trait provides a large enough selective
advantage. We test this hypothesis using a population based model of protein
evolution. If an individual acquires one of two mutations needed for a novel
trait, the second mutation can be introduced into the phenotype due to
transcription and translation errors. If the novel trait is advantageous
enough, the allele with only one mutation will spread through the population,
even though the gene sequence does not yet code for the complete trait. The
first mutation then has a higher frequency than expected without phenotypic
mutations giving the second mutation a higher probability of fixation. Thus,
errors allow protein sequences to ''look-ahead'' for a more direct path to a
complex trait.


title: Reliability of Module Based Software System

abstract:
  This paper consider the problem of determining the reliability of a software
system which can be decomposed in a number of modules. We have derived the
expression of the reliability of a system using the Markovian model for the
transfer of control between modules in order. We have given the expression of
reliability by considering both benign and catastrophic failure. The expression
of reliability presented in this work is applicable for some control software
which are designed to detect its own internal errors.


title: Dark Energy, Induced Gravity and Broken Scale Invariance

abstract:
  We study the cosmological evolution of an induced gravity model with a
self-interacting scalar field $\sigma$ and in the presence of matter and
radiation. Such model leads to Einstein Gravity plus a cosmological constant as
a stable attractor among homogeneous cosmologies and is therefore a viable
dark-energy (DE) model for a wide range of scalar field initial conditions and
values for its positive $\gamma$ coupling to the Ricci curvature $\gamma
\sigma^{2}R$.


title: Relic gravitons from super-inflation

abstract:
  The super-inflationary phase is predicted by the Loop Quantum Cosmology. In
this paper we study the creation of gravitational waves during this phase. We
consider the inverse volume corrections to the equation for the tensor modes
and calculate the spectrum of the produced gravitons. The amplitude of the
obtained spectrum as well as maximal energy of gravitons strongly depend on the
evolution of the Universe after the super-inflation. We show that a further
standard inflationary phase is necessary to lower the amount of gravitons below
the present bound. In case of the lack of the standard inflationary phase, the
present intensity of gravitons would be extremely large. These considerations
give us another motivation to introduce the standard phase of inflation.


title:
Non-minimal coupling as a mechanism for spontaneous symmetry breaking on
  the brane

abstract:
  Motivated by the dimensional asymmetry characteristic of braneworlds, we
populate the bulk spacetime with matter scalar fields, both real and complex,
and couple them non-minimally to gravity. We derive the effective equations of
motion on the brane and realize the case when the fields acquire a
non-vanishing vacuum expectation value. This entails a change in the effective
cosmological constant and in the effective mass of the scalar fields. We find
that the non-minimal coupling provides a mechanism for generating spontaneous
symmetry breaking at Planck energies on the brane. This mechanism is however
rendered unviable for the generation of masses at the energy scales of the
standard model.


title: Electromagnetic form factors of the Delta baryon

abstract:
  We develop a methodology that enables us to extract accurately the
electromagnetic Delta form factors and their momentum dependence. We test our
approach in the quenched approximation as a preparation for a study using
dynamical fermions. Our calculation of the four form factors covers pion masses
between about 410 MeV and 560 MeV on lattices with a size of 2.9 fm and a
lattice spacing 0.09 fm. From the form factors we are able to obtain estimates
of the magnetic moment and the charge radius of the Delta, which we compare to
existing experimental and theoretical results.Our non-zero result for the
electric quadrupole form factor signals a deformation of the Delta, pointing to
an oblate charge distribution.


title:
Two-dimensional multisolitons and azimuthons in Bose-Einstein
  condensates with attraction

abstract:
  We present spatially localized nonrotating and rotating (azimuthon)
multisolitons in the two-dimensional (2D) ("pancake-shaped configuration")
Bose-Einstein condensate (BEC) with attractive interaction. By means of a
linear stability analysis, we investigate the stability of these structures and
show that rotating dipole solitons are stable provided that the number of atoms
is small enough. The results were confirmed by direct numerical simulations of
the 2D Gross-Pitaevskii equation.


title:
Kullback Leibler property of kernel mixture priors in Bayesian density
  estimation

abstract:
  Positivity of the prior probability of Kullback-Leibler neighborhood around
the true density, commonly known as the Kullback-Leibler property, plays a
fundamental role in posterior consistency. A popular prior for Bayesian
estimation is given by a Dirichlet mixture, where the kernels are chosen
depending on the sample space and the class of densities to be estimated. The
Kullback-Leibler property of the Dirichlet mixture prior has been shown for
some special kernels like the normal density or Bernstein polynomial, under
appropriate conditions. In this paper, we obtain easily verifiable sufficient
conditions, under which a prior obtained by mixing a general kernel possesses
the Kullback-Leibler property. We study a wide variety of kernel used in
practice, including the normal, $t$, histogram, gamma, Weibull densities and so
on, and show that the Kullback-Leibler property holds if some easily verifiable
conditions are satisfied at the true density. This gives a catalog of
conditions required for the Kullback-Leibler property, which can be readily
used in applications.


title:
Simulations of the consequences of tongue surgery on tongue mobility:
  implications for speech production in post-surgery conditions

abstract:
  This paper presents simulations of the impact of tongue surgery on tongue
movements and on speech articulation. For this, a 3D biomechanical Finite
Element (FE) model of the tongue is used. Muscles are represented within the FE
structure by specific subsets of elements. The tongue model is inserted in the
upper airways including jaw, palate and pharyngeal walls. Two examples of
tongue surgery, which are quite common in the treatment of cancers of the oral
cavity are modelled: hemiglossectomy and large resection of the mouth floor.
Three kinds of reconstruction are also modelled, assuming flaps with a low,
medium or high stiffnesses. The impact of the surgery without any
reconstruction and with the three different reconstructions is quantitatively
measured and compared during simulated speech production sequences. More
precisely, differences in global 3D tongue shape and in velocity patterns
during tongue displacements are evaluated.


title:
Algebraic curves for commuting elements in the q-deformed Heisenberg
  algebra

abstract:
  In this paper we extend the eliminant construction of Burchnall and Chaundy
for commuting differential operators in the Heisenberg algebra to the
q-deformed Heisenberg algebra and show that it again provides annihilating
curves for commuting elements, provided q satisfies a natural condition. As a
side result we obtain estimates on the dimensions of the eigenspaces of
elements of this algebra in its faithful module of Laurent series.


title: Coupling of Surface and Volume Dipole Oscillations in C-60 Molecules

abstract:
  We first give a short review of the ``local-current approximation'' (LCA),
derived from a general variation principle, which serves as a semiclassical
description of strongly collective excitations in finite fermion systems
starting from their quantum-mechanical mean-field ground state. We illustrate
it for the example of coupled translational and compressional dipole
excitations in metal clusters. We then discuss collective electronic dipole
excitations in C$_{60}$ molecules (Buckminster fullerenes). We show that the
coupling of the pure translational mode (``surface plasmon'') with
compressional volume modes in the semiclasscial LCA yields semi-quantitative
agreement with microscopic time-dependent density functional (TDLDA)
calculations, while both theories yield qualitative agreement with the recent
experimental observation of a ``volume plasmon''.

categories: physics.atm-clus nucl-th physics.atom-ph physics.flu-dyn


title: Transition from galactic to extragalactic cosmic rays

abstract:
  The transition from galactic to extragalactic cosmic rays is discussed. One
of critical indications for transition is given by the Standard Model of
Galactic cosmic rays, according to which the maximum energy of acceleration for
iron nuclei is of order of $E_{\rm Fe}^{\rm max} \approx 1\times 10^{17}$ eV.
At $E > E_{\rm Fe}^{\rm max}$ the spectrum is predicted to be very steep and
thus the Standard Model favours the transition at energy not much higher than
$E_{\rm Fe}^{\rm max}$. As observations are concerned there are two signatures
of transition: change of energy spectra and elongation rate (depth of shower
maximum in the atmosphere $X_{\rm max}$ as function of energy). Three models of
transition are discussed: dip-based model, mixed composition model and ankle
model. In the latter model the transition occurs at the observed spectral
feature, ankle, which starts at $E_a \approx 1\times 10^{19}$ eV and is
characterised by change of mass compostion from galactic iron to extragalactic
protons. In the dip model the transition occures at the second knee observed at
energy $(4 -8)\times 10^{17}$ eV and is characterised by change of mass
composition from galactic iron to extragalactic protons. The mixed composition
model describes transition at $E \sim 3\times 10^{18}$ eV with mass composition
changing from galactic iron to extragactic mixed composition of different
nuclei. These models are confronted with observational data on spectra and
elongation rates from different experiments, including Auger.


title:
A note on mean volume and surface densities for a class of
  birth-and-growth stochastic processes

abstract:
  Many real phenomena may be modelled as locally finite unions of
$d$-dimensional time dependent random closed sets in $\mathbb{R}^d$, described
by birth-and-growth stochastic processes, so that their mean volume and surface
densities, as well as the so called mean \emph{extended} volume and surface
densities, may be studied in terms of relevant quantities characterizing the
process. We extend here known results in the Poissonian case to a wider class
of birth-and-growth stochastic processes, proving in particular the absolute
continuity of the random time of capture of a point $x\in\R^d$ by processes of
this class.


title:
Future plan for observation of cosmic gamma rays in the 100 TeV energy
  region with the Tibet air shower array : simulation and sensitivity

abstract:
  The Tibet air shower array, which has an effective area of 37,000 square
meters and is located at 4300 m in altitude, has been observing air showers
induced by cosmic rays with energies above a few TeV. We have a plan to add a
large muon detector array to it for the purpose of increasing its sensitivity
to cosmic gamma rays in the 100 TeV energy region by discriminating them from
cosmic-ray hadrons. We have deduced the attainable sensitivity of the muon
detector array using our Monte Carlo simulation. We report here on the detailed
procedure of our Monte Carlo simulation.


title:
Effects of anharmonic vibration on large-angle quasi-elastic scattering
  of 16O+144Sm

abstract:
  We study the effects of double octupole and quadrupole phonon excitations in
the 144Sm nucleus on quasi-elastic 16O+144Sm scattering at backward angles. To
this end, we use the coupled-channels framework, taking into account explicitly
the anharmonicities of the vibrations. We use the same coupling scheme as that
previously employed to explain the experimental data of sub-barrier fusion
cross sections for the same system. We show that the experimental data for the
quasi-elastic cross sections are well reproduced in this way, although the
quasi-elastic barrier distribution has a distinct high energy peak which is
somewhat smeared in the experimental barrier distribution. We also discuss the
effects of proton transfer on the quasi-elastic barrier distribution. Our study
indicates that the fusion and quasi-elastic barrier distributions for this
system cannot be accounted for simultaneously with the standard
coupled-channels approach.


title:
A comparison between detailed and configuration-averaged
  collisional-radiative codes applied to non-local thermal equilibrium plasma

abstract:
  A collisional-radiative model describing nonlocal-thermodynamic-equilibrium
plasmas is developed. It is based on the HULLAC (Hebrew University Lawrence
Livermore Atomic Code) suite for the transitions rates, in the zero-temperature
radiation field hypothesis. Two variants of the model are presented: the first
one is configuration averaged, while the second one is a detailed level
version. Comparisons are made between them in the case of a carbon plasma; they
show that the configuration-averaged code gives correct results for an
electronic temperature Te=10 eV (or higher) but fails at lower temperatures
such as Te=1 eV. The validity of the configuration-averaged approximation is
discussed: the intuitive criterion requiring that the average
configuration-energy dispersion must be less than the electron thermal energy
turns out to be a necessary but far from sufficient condition. Another
condition based on the resolution of a modified rate-equation system is
proposed. Its efficiency is emphasized in the case of low-temperature plasmas.
Finally, it is shown that near-threshold autoionization cascade processes may
induce a severe failure of the configuration-average formalism.


title: Reduced branching processes with very heavy tails

abstract:
  The reduced Markov branching process is a stochastic model for the genealogy
of an unstructured biological population. Its limit behavior in the critical
case is well studied for the Zolotarev-Slack regularity parameter
$\alpha\in(0,1]$. We turn to the case of very heavy tailed reproduction
distribution $\alpha=0$ assuming Zubkov's regularity condition with parameter
$\beta\in(0,\infty)$. Our main result gives a new asymptotic pattern for the
reduced branching process conditioned on non-extinction during a long time
interval.


title:
From Holonomy of the Ising Model Form Factors to n-Fold Integrals and
  the Theory of Elliptic Curve

abstract:
  We recall the form factors $ f^{(j)}_{N,N}$ corresponding to the
$\lambda$-extension $C(N,N; \lambda)$ of the two-point diagonal correlation
function of the Ising model on the square lattice and their associated linear
differential equations which exhibit both a ``Russian-doll'' nesting, and a
decomposition of the linear differential operators as a direct sum of operators
(equivalent to symmetric powers of the differential operator of the complete
elliptic integral $E$). The scaling limit of these differential operators
breaks the direct sum structure but not the ``Russian doll'' structure, the
``scaled'' linear differential operators being no longer Fuchsian. We then
introduce some multiple integrals of the Ising class expected to have the same
singularities as the singularities of the $n$-particle contributions
$\chi^{(n)}$ to the susceptibility of the square lattice Ising model. We find
the Fuchsian linear differential equations satisfied by these multiple
integrals for $n=1,2,3,4$ and, only modulo a prime, for $n=5$ and 6, thus
providing a large set of (possible) new singularities of the $\chi^{(n)}$. ...

categories: math-ph cond-mat.stat-mech hep-th math.CA math.MP


title:
Future plan for observation of cosmic gamma rays in the 100 TeV energy
  region with the Tibet air shower array : physics goal and overview

abstract:
  The Tibet air shower array, which has an effective area of 37,000 square
meters and is located at 4300 m in altitude, has been observing air showers
induced by cosmic rays with energies above a few TeV. We are planning to add a
large muon detector array to it for the purpose of increasing its sensitivity
to cosmic gamma rays in the 100 TeV (10 - 1000 TeV) energy region by
discriminating them from cosmic-ray hadrons. We report on the possibility of
detection of gamma rays in the 100 TeV energy region in our field of view,
based on the improved sensitivity of our air shower array deduced from the full
Monte Carlo simulation.


title:
The fundamental theorem of asset pricing under proportional transaction
  costs

abstract:
  We extend the fundamental theorem of asset pricing to a model where the risky
stock is subject to proportional transaction costs in the form of bid-ask
spreads and the bank account has different interest rates for borrowing and
lending. We show that such a model is free of arbitrage if and only if one can
embed in it a friction-free model that is itself free of arbitrage, in the
sense that there exists an artificial friction-free price for the stock between
its bid and ask prices and an artificial interest rate between the borrowing
and lending interest rates such that, if one discounts this stock price by this
interest rate, then the resulting process is a martingale under some
non-degenerate probability measure. Restricting ourselves to the simple case of
a finite number of time steps and a finite number of possible outcomes for the
stock price, the proof follows by combining classical arguments based on
finite-dimensional separation theorems with duality results from linear
optimisation.


title:
Structural anomalies, spin transitions and charge disproportionation in
  LnCoO3

abstract:
  The diamagnetic-paramagnetic and insulator-metal transitions in LnCoO3
perovskites (Ln = La, Y, rare earths) are reinterpreted and modeled as a
two-level excitation process. In distinction to previous models, the present
approach can be characterized as a LS-HS-IS (low-high-intermediate spin)
scenario. The first level is the local excitation of HS Co3+ species in the LS
ground state. The second excitation is based on the interatomic electron
transfer between the LS/HS pairs, leading finally to a stabilization of the
metallic phase based on IS Co3+. The model parameters have been quantified for
Ln = La, Pr and Nd samples using the powder neutron diffraction on the thermal
expansion of Co-O bonds, that is associated with the two successive spin
transitions. The same model is applied to interpret the magnetic susceptibility
of LaCoO3 and YCoO3.


title:
A quantitative study of quasiparticle traps using the
  single-Cooper-pair-transistor

abstract:
  We use radio-frequency reflectometry to measure quasiparticle tunneling rates
in the single-Cooper-pair-transistor. Devices with and without quasiparticle
traps in proximity to the island are studied. A $10^2$ to $10^3$-fold reduction
in the quasiparticle tunneling rate onto the island is observed in the case of
quasiparticle traps. In the quasiparticle trap samples we also measure a
commensurate decrease in quasiparticle tunneling rate off the island.


title:
VLT-VIMOS integral field spectroscopy of luminous and ultraluminous
  infrared galaxies. I. The sample and first results

abstract:
  (Ultra)Luminous Infrared Galaxies [(U)LIRGs] are much more numerous at
cosmological distances than locally, and are likely precursors of elliptical
galaxies. Our goal is to carry out an integral field spectroscopic survey of a
representative sample of low redshift (z < 0.26) (U)LIRGs, covering different
morphologies from spirals to mergers over the entire infrared luminosity range.
The present study is based on optical IFS obtained with the VIMOS instrument on
the VLT. The first results of this survey are presented here with the study of
two galaxies representative of the two major morphological types observed in
(U)LIRGs, interacting pairs and morphologically- regular, weakly-interacting
spirals, respectively. We have found that IRAS 06076-2139 consists of two
low-intermediate mass (0.15 and 0.4 m*) galaxies with relative velocities of ~
550 km/s and, therefore, it is unlikely that they will merge. The VIMOS IFS has
also discovered the presence of a rapidly expanding and rotating ring of gas in
the southern galaxy (Gs), likely due to a nearly central head-on passage of an
intruder about 140 million years ago. IRASF 12115-4656 is a spiral for which we
have found a mass of 1.2 m*. The neutral gas (traced by the NaI doublet) and
ionized gas components are spatially and kinematically decoupled. The analysis
presented here illustrates the full potential of IFS in two important aspects:
(i) the study of the kinematics and ionization structure of complex
interacting/merging systems, and (2i) the study of the kinematics of the
different gas phases, neutral (cool) and ionized (warm), traced by the NaD and
Halpha lines, respectively. (abbreviated)


title: Valence and spin states in perovskites LaCo0.95M0.05O3 (M = Mg, Ga, Ti)

abstract:
  The samples LaCoO3 with dilute substitutions on cobalt sites have been
studied using the resistivity, thermopower and magnetic susceptibility
measurements over the temperature range up to ~900 K. The Co-site substitution
does not affect the magnetic transition at ~100 K and the onset of massive
population of hole carriers at ~500 K, characteristic for undoped LaCoO3. On
the other hand, the low-temperature transport and magnetism is markedly
distinct for samples with extra charge on cobalt ions introduced by the
heterovalent dopants (Mg2+, Ti4+) compared to samples with minor
non-stoichiometry (LaCoO3, Ga3+ doped sample). Magnetic properties suggest that
these extra charges create thermally stable magnetic polarons of total S ~ 2-3.
Common features of Co-site doped and La-site doped samples (La1-xSrxCoO3) are
discussed


title: Threefolds with big and nef anticanonical bundles II

abstract:
  In continuation of our paper in Math. Ann. 333 we classify smooth complex
projective threefolds X with -K_X big and nef but not ample and Picard number
2, whose anticanonical map is small. We assume also that the Mori contraction
of X and of its flop are not both birational.


title:
On the Equivalent Theory of the Generalized \tau^{(2)}-model and the
  Chiral Potts Model with two Alternating Vertical Rapidities

abstract:
  By the Baxter's $Q_{72}$-operator method, we demonstrate the equivalent
theory between the generalized $\tau^{(2)}$-model (other than two special cases
with a pseudovacuum state) and the $N$-state chiral Potts model with two
alternating vertical rapidities, where the degenerate models are included. As a
consequence, the theory of the XXZ chain model associated to cyclic
representations (with the parameter $\varsigma$) of $U_{\sf q}(sl_2)$ with
${\sf q}^N=1$ for odd $N$ is identified with either (for $\varsigma^N=1$) the
chiral Potts model with two superintegrable vertical rapidities, or (for
$\varsigma^N \neq 1$) the degenerate model for the selfdual solution of the
star-triangle relation. In all these identifications, the transfer matrices $T,
\hat{T}$ of the chiral Potts model (including the degenerate ones) serve as the
$Q_R, Q_L$-operators of the corresponding $\tau^{(2)}$-model, so that the
functional relations hold as in the solvable $N$-state chiral Potts model.

categories: cond-mat.stat-mech hep-th math-ph math.AG math.MP nlin.SI


title:
Note on the existence theorem in ``Emergent Quantum Mechanics and
  Emergent Symmetries''

abstract:
  Recently 't Hooft demonstrated that ``For any quantum system there exists at
least one deterministic model that reproduces all its dynamics after
prequantization''. An extension is presented here which covers quantum systems
that are characterized by a complete set of mutually commuting Hermitian
operators (``beables''). We introduce the symmetry of beables: any complete set
of beables is as good as any other one which is obtained through a real general
linear group transformation. The quantum numbers of a specific set are related
to symmetry breaking initial and boundary conditions in a deterministic model.
The Hamiltonian, in particular, can be taken as the emergent beable which
provides the best resolution of the evolution of the model universe.


title:
Thermodynamic properties of Holstein polarons and the effects of
  disorder

abstract:
  The ground state and finite temperature properties of polarons are studied
considering a two-site and a four-site Holstein model by exact diagonalization
of the Hamiltonian. The kinetic energy, Drude weight, correlation functions
involving charge and lattice deformations, and the specific heat have been
evaluated as a function of electron-phonon (e-ph) coupling strength and
temperature. The effects of site diagonal disorder on the above properties have
been investigated. The disorder is found to suppress the kinetic energy and the
Drude weight, reduces the spatial extension of the polaron, and makes the
large-to-small polaron crossover smoother. Increasing temperature also plays
similar role. For strong coupling the kinetic energy arises mainly from the
incoherent hopping processes owing to the motion of electrons within the
polaron and is almost independent of the disorder strength. From the coherent
and incoherent contributions to the kinetic energy, the temperature above which
the incoherent part dominates is determined as a function of e-ph coupling
strength.


title: Irreducible polynomials with prescribed trace and restricted norm

abstract:
  Let GF(q), q=p^r, be a finite field with a primitive element g. In this paper
we use exponential sums and Jacobi sums to compute the number of the
irreducible polynomials of degree m over GF(q) with trace fixed and norm
restricted to a coset of a subgroup <g^s>, s|(q-1). We give the number
explicitly for s=2, 3, 4 when q=p, and for s|(p^e+1) when r=2en. Finally, we
give explicit formulae for the number when both trace and norm are fixed, p=2
and m =< 30.


title: On a problem of Juhasz and van Mill

abstract:
  A 27 years old and still open problem of Juhasz and van Mill asks whether
there exists a cardinal kappa such that every regular dense in itself countably
compact space has a dense in itself subset of cardinality at most kappa. We
give a negative answer for the analogous question where_regular_ is weakened
to_Hausdorff_, and_coutnably compact_ is strengthened to_sequentially compact_.


title:
Renormalization of the vacuum angle in quantum mechanics, Berry phase
  and continuous measurements

abstract:
  The vacuum angle $\theta$ renormalization is studied for a toy model of a
quantum particle moving around a ring, threaded by a magnetic flux $\theta$.
Different renormalization group (RG) procedures lead to the same generic RG
flow diagram, similar to that of the quantum Hall effect. We argue that the
renormalized value of the vacuum angle may be observed if the particle's
position is measured with finite accuracy or coupled to additional slow
variable, which can be viewed as a coordinate of a second (heavy) particle on
the ring. In this case the renormalized $\theta$ appears as a magnetic flux
this heavy particle sees, or the Berry phase, associated with its slow
rotation.


title: Renormalizing the Schrodinger Equation for NN scattering

abstract:
  The renormalization of the Schr"odinger equation with regular One Boson
Exchange and singular chiral potentials including One and Two-Pion exchanges is
analyzed within the context of NN scattering.


title: Hard exclusive scattering at Jlab

abstract:
  The various factorization schemes for hard exclusive processes and the status
of their applications is briefly reviewed.


title:
Significant g-factor values of a two-electron ground state in quantum
  dots with spin-orbit coupling

abstract:
  The magnetization of semiconductor quantum dots in the presence of spin-orbit
coupling and interactions is investigated numerically. When the dot is occupied
by two electrons we find that a level crossing between the two lowest many-body
eigenstates may occur as a function of the spin-orbit coupling strength. This
level crossing is accompanied by a non-vanishing magnetization of the
ground-state. Using first order perturbation theory as well as exact numerical
diagonalization of small clusters we show that the tendency of interactions to
cause Stoner-like instability is enhanced by the SO coupling. The resulting
g-factor can have a significant value, and thus may influence g-factor
measurements. Finally we propose an experimental method by which the predicted
phenomenon can be observed.


title:
Ramond-Ramond Fields, Fractional Branes and Orbifold Differential
  K-Theory

abstract:
  We study D-branes and Ramond-Ramond fields on global orbifolds of Type II
string theory with vanishing H-flux using methods of equivariant K-theory and
K-homology. We illustrate how Bredon equivariant cohomology naturally realizes
stringy orbifold cohomology. We emphasize its role as the correct cohomological
tool which captures known features of the low-energy effective field theory,
and which provides new consistency conditions for fractional D-branes and
Ramond-Ramond fields on orbifolds. We use an equivariant Chern character from
equivariant K-theory to Bredon cohomology to define new Ramond-Ramond couplings
of D-branes which generalize previous examples. We propose a definition for
groups of differential characters associated to equivariant K-theory. We derive
a Dirac quantization rule for Ramond-Ramond fluxes, and study flat
Ramond-Ramond potentials on orbifolds.


title: Final state interaction and \Delta I=1/2 rule

abstract:
  Contrary to wide-spread opinion that the final state interaction (FSI)
enhances the amplitude <2\pi;I=0|K^0>, we argue that FSI does not increase the
absolute value of this amplitude.


title: Dam Rain and Cumulative Gain

abstract:
  We consider a financial contract that delivers a single cash flow given by
the terminal value of a cumulative gains process. The problem of modelling and
pricing such an asset and associated derivatives is important, for example, in
the determination of optimal insurance claims reserve policies, and in the
pricing of reinsurance contracts. In the insurance setting, the aggregate
claims play the role of the cumulative gains, and the terminal cash flow
represents the totality of the claims payable for the given accounting period.
A similar example arises when we consider the accumulation of losses in a
credit portfolio, and value a contract that pays an amount equal to the
totality of the losses over a given time interval. An explicit expression for
the value process is obtained. The price of an Arrow-Debreu security on the
cumulative gains process is determined, and is used to obtain a closed-form
expression for the price of a European-style option on the value of the asset.
The results obtained make use of various remarkable properties of the gamma
bridge process, and are applicable to a wide variety of financial products
based on cumulative gains processes such as aggregate claims, credit portfolio
losses, defined-benefit pension schemes, emissions, and rainfall.


title:
New constraints on the membership of the T dwarf S Ori 70 in the sigma
  Orionis cluster

abstract:
  (Abridged) The nature of S Ori 70, a faint mid-T type object found towards
the direction of the young sigma Orionis cluster, is still under debate. We
intend to disentangle whether it is a field brown dwarf or a 3-Myr old
planetary-mass member of the cluster. We report on near-infrared JHK_s and
mid-infrared [3.6] and [4.5] IRAC/Spitzer photometry recently obtained for S
Ori 70. The new near-infrared images (taken 3.82 yr after the discovery data)
have allowed us to derive a very small proper motion (11.0 +/- 5.9 mas/yr) for
this object, which is consistent with the proper motion of the cluster within
1.5 sigma the astrometric uncertainty. The colors (H-K_s), (J-K_s) and
K_s-[3.6] appear discrepant when compared to T4-T7 dwarfs in the field. This
behavior could be ascribed to a low-gravity atmosphere or alternatively to an
atmosphere with a metallicity significantly different than solar. Taking into
account the small proper motion of S Ori 70 and its new near- and mid-infrared
colors, a low-gravity atmosphere remains as the most likely explanation to
account for our observations. This supports S Ori 70's membership in sigma
Orionis, with an estimated mass in the interval 2-7 Mjup, in agreement with our
previous derivation.


title: Teleportation of two-mode squeezed states

abstract:
  We consider two-mode squeezed states which are parametrized by the squeezing
parameter and the phase. We present a scheme for teleporting such entangled
states of continuous variables from Alice to Bob. Our protocol is
operationalized through the creation of a four-mode entangled state shared by
Alice and Bob using linear amplifiers and beam splitters. Teleportation of the
entangled state proceeds with local operations and the classical communication
of four bits. We compute the fidelity of teleportation and find that it
exhibits a trade-off with the magnitude of entanglement of the resultant
teleported state.


title:
Determining the crystal-field ground state in rare earth Heavy Fermion
  materials using soft-x-ray absorption spectroscopy

abstract:
  We infer that soft-x-ray absorption spectroscopy is a versatile method for
the determination of the crystal-field ground state symmetry of rare earth
Heavy Fermion systems, complementing neutron scattering. Using realistic and
universal parameters, we provide a theoretical mapping between the polarization
dependence of Ce $M_{4,5}$ spectra and the charge distribution of the Ce $4f$
states. The experimental resolution can be orders of magnitude larger than the
$4f$ crystal field splitting itself. To demonstrate the experimental
feasibility of the method, we investigated CePd$_2$Si$_2$, thereby settling an
existing disagreement about its crystal-field ground state.


title:
Quantum degenerate two-species Fermi-Fermi mixture coexisting with a
  Bose-Einstein condensate

abstract:
  We report on the generation of a quantum degenerate Fermi-Fermi mixture of
two different atomic species. The quantum degenerate mixture is realized
employing sympathetic cooling of fermionic Li-6 and K-40 gases by an
evaporatively cooled bosonic Rb-87 gas. We describe the combination of trapping
and cooling methods that proved crucial to successfully cool the mixture. In
particular, we study the last part of the cooling process and show that the
efficiency of sympathetic cooling of the Li-6 gas by Rb-87 is increased by the
presence of K-40 through catalytic cooling. Due to the differing physical
properties of the two components, the quantum degenerate Li-6 K-40 Fermi-Fermi
mixture is an excellent candidate for a stable, heteronuclear system allowing
to study several so far unexplored types of quantum matter.


title:
The Optical Gravitational Lensing Experiment. Period-Luminosity
  Relations of Variable Red Giant Stars

abstract:
  Period-luminosity (PL) relations of variable red giants in the Large (LMC)
and Small Magellanic Clouds (SMC) are presented. The PL diagrams are plotted in
three planes: logP-K_S, logP-W_{JK}, and logP-W_I. Fourteen PL sequences are
distinguishable, and some of them consist of three closely spaced ridges. Each
of the sequences is fitted with a linear or quadratic function. The
similarities and differences between the PL relations in both galaxies are
discussed for four types of red giant variability: OGLE Small Amplitude Red
Giants (OSARGs), Miras and Semiregular Variables (SRVs), Long Secondary Periods
(LSPs) and ellipsoidal variables. We propose a new method of separating OSARGs
from non-variable stars and SRVs. The method employs the position in the
reddening-free PL diagrams and the characteristic period ratios of these
multiperiodic variables. The PL relations for the LMC OSARG are compared with
the calculated relations for RGB models along isochrones of relevant ages and
metallicities. We also compare measured periods and amplitudes of the OSARGs
with predictions based on the relations valid for less luminous solar-like
pulsators. Miras and SRVs seem to follow PL relation of the same slopes in the
LMC and SMC, while for LSP and ellipsoidal variables slopes in both galaxies
are different. The PL sequences defined by LSP variables and binary systems
overlap in the whole range of analyzed wavebands. We put forward new arguments
for the binary star scenario as an explanation of the LSP variability and
elaborate on it further. The measured pulsation to orbital period ratio implies
nearly constant ratio of the star radius to orbital distance, R/A=0.4, as we
find. Combined effect of tidal friction and mass loss enhanced by the low-mass
companion may explain why such a value is preferred.


title: Rhombus Filtrations and Rauzy Algebras

abstract:
  Peach introduced rhombal algebras associated to quivers given by tilings of
the plane by rhombi. We develop general techniques to analyse rhombal algebras,
including a filtration by what we call rhombus modules.
  We introduce a way to relate the infinite-dimensional rhombal algebra
corresponding to a complete tiling of the plane to finite-dimensional algebras
corresponding to finite portions of the tiling. Throughout, we apply our
general techniques to the special case of the Rauzy tiling, which is built in
stages reflecting an underlying self-similarity. Exploiting this self-similar
structure allows us to uncover interesting features of the associated
finite-dimensional algebras, including some of the tree classes in the stable
Auslander-Reiten quiver.


title: Effective linkage learning using low-order statistics and clustering

abstract:
  The adoption of probabilistic models for the best individuals found so far is
a powerful approach for evolutionary computation. Increasingly more complex
models have been used by estimation of distribution algorithms (EDAs), which
often result better effectiveness on finding the global optima for hard
optimization problems. Supervised and unsupervised learning of Bayesian
networks are very effective options, since those models are able to capture
interactions of high order among the variables of a problem. Diversity
preservation, through niching techniques, has also shown to be very important
to allow the identification of the problem structure as much as for keeping
several global optima. Recently, clustering was evaluated as an effective
niching technique for EDAs, but the performance of simpler low-order EDAs was
not shown to be much improved by clustering, except for some simple multimodal
problems. This work proposes and evaluates a combination operator guided by a
measure from information theory which allows a clustered low-order EDA to
effectively solve a comprehensive range of benchmark optimization problems.


title: Void Statistics and Void Galaxies in the 2dFGRS

abstract:
  For the 2dFGRS we study the properties of voids and of fainter galaxies
within voids that are defined by brighter galaxies. Our results are compared
with simulated galaxy catalogues from the Millenium simulation coupled with a
semianalytical galaxy formation recipe. We derive the void size distribution
and discuss its dependence on the faint magnitude limit of the galaxies
defining the voids. While voids among faint galaxies are typically smaller than
those among bright galaxies, the ratio of the void sizes to the mean galaxy
separation reaches larger values. This is well reproduced in the mock galaxy
samples studied. We provide analytic fitting functions for the void size
distribution. Furthermore, we study the galaxy population inside voids defined
by objects with $B_J -5\log{h}< -20$ and diameter larger than 10 \hMpc. We find
a clear bimodality of the void galaxies similar to the average comparison
sample. We confirm the enhanced abundance of galaxies in the blue cloud and a
depression of the number of red sequence galaxies. There is an indication of a
slight blue shift of the blue cloud. Furthermore, we find that galaxies in void
centers have higher specific star formation rates as measured by the $\eta$
parameter. We determine the radial distribution of the ratio of early and late
type galaxies through the voids. We find and discuss some differences between
observations and the Millenium catalogues.


title: Routes to thermodynamic limit on scale-free networks

abstract:
  We show that there are two classes of finite size effects for dynamic models
taking place on a scale-free topology. Some models in finite networks show a
behavior that depends only on the system size N. Others present an additional
distinct dependence on the upper cutoff k_c of the degree distribution. Since
the infinite network limit can be obtained by allowing k_c to diverge with the
system size in an arbitrary way, this result implies that there are different
routes to the thermodynamic limit in scale-free networks. The contact process
(in its mean-field version) belongs to this second class and thus our results
clarify the recent discrepancy between theory and simulations with different
scaling of k_c reported in the literature.


title: Monte Carlo Generators for the LHC

abstract:
  The status of two Monte Carlo generators, HELAC-PHEGAS, a program for
multi-jet processes and VBFNLO, a parton level program for vector boson fusion
processes at NLO QCD, is briefly presented. The aim of these tools is the
simulation of events within the Standard Model at current and future high
energy experiments, in particular the LHC. Some results related to the
production of multi-jet final states at the LHC are also shown.


title: Higgsless electroweak symmetry breaking at the LHC

abstract:
  While the Higgs model is the best studied scenario of electroweak symmetry
breaking, a number strongly-coupled models exist, predicting new signatures.
Recent studies of WW and WZ final states at the ATLAS and CMS experiments are
summarized and expected sensitivities are presented within the frameworks of
the technicolor straw-man model and the electroweak chiral Lagrangian.


title: The shuffle Hopf algebra and quasiplanar Wick products

abstract:
  The operator valued distributions which arise in quantum field theory on the
noncommutative Minkowski space can be symbolized by a generalization of chord
diagrams, the dotted chord diagrams. In this framework, the combinatorial
aspects of quasiplanar Wick products are understood in terms of the shuffle
Hopf algebra of dotted chord diagrams, leading to an algebraic characterization
of quasiplanar Wick products as a convolution. Moreover, it is shown that the
distributions do not provide a weight system for universal knot invariants.


title:
Exploring the QCD vacuum - (some) recent developments in confinement and
  topology

abstract:
  I start by giving a brief overview over new developments in the area of
confinement and topology. As an example for the interrelations between
topological objects, instantons at finite temperature are discussed. Then I
focus on new insights into the structure of the QCD vacuum obtained through
filtering methods, in particular those based on decompositions w.r.t. fermionic
eigenmodes.


title:
SGR 1806-20 about two years after the giant flare: Suzaku, XMM-Newton
  and INTEGRAL observations

abstract:
  In December 2004, the soft gamma-ray repeater SGR 1806-20 emitted the most
powerful giant flare ever observed. This probably involved a large-scale
rearrangement of the magnetosphere leading to observable variations in the
properties of its X-ray emission. Here we present the results of the first
Suzaku observation of SGR 1806-20, together with almost simultaneous
observations with XMM-Newton and INTEGRAL. The source seems to have reached a
state characterized by a flux close to the pre-flare level and by a relatively
soft spectrum. Despite this, SGR 1806-20 remained quite active also after the
giant flare, allowing us to study several short bursts observed by Suzaku in
the 1-100 keV range. We discuss the broad-band spectral properties of SGR
1806-20, covering both persistent and bursting emission, in the context of the
magnetar model, and consider its recent theoretical developments.


title: PNJL model with a Van der Monde term

abstract:
  We extend the Polyakov-Nambu-Jona-Lasinio (PNJL) model for two degenerate
flavours by including the effect of the SU(3) measure with a Van der Monde
(VdM) term. This ensures that the Polyakov loop always remains in the domain
[0,1]. The pressure, energy density, specific heat, speed of sound and
conformal measure show small or negligible effects from this term. However
various quark number and isospin susceptibilities are all found to approach
their respective ideal gas limits around 2 $T_c$. We compare our methods with
other similar approaches in PNJL model and also present a quantitative
comparison with Lattice QCD data.


title: Drift instability and tunneling of lattice solitons

abstract:
  We derive an analytic formula for the lateral dynamics of solitons in a
general inhomogeneous nonlinear media, and show that it can be valid over tens
of diffraction lengths. In particular, we show that solitons centered at a
lattice maximum can be ``mathematically unstable'' but ``physically stable''.
We also derive an analytic upper bound for the critical velocity for tunneling,
which is valid even when the standard Peierls-Nabarro potential approach fails.


title: Market completion using options

abstract:
  Mathematical models for financial asset prices which include, for example,
stochastic volatility or jumps are incomplete in that derivative securities are
generally not replicable by trading in the underlying. In earlier work (2004)
the first author provided a geometric condition under which trading in the
underlying and a finite number of vanilla options completes the market. We
complement this result in several ways. First, we show that the geometric
condition is not necessary and a weaker, necessary and sufficient, condition is
presented. While this condition is generally not directly verifiable, we show
that it simplifies to matrix non-degeneracy in a single point when the pricing
functions are real analytic functions. In particular, any stochastic volatility
model is then completed with an arbitrary European type option. Further, we
show that adding path-dependent options such as a variance swap to the set of
primary assets, instead of plain vanilla options, also completes the market.


title: The SGR 1806-20 magnetar signature on the Earth's magnetic field

abstract:
  SGRs denote ``soft $\gamma$-ray repeaters'', a small class of slowly spinning
neutron stars with strong magnetic fields. On 27 December 2004, a giant flare
was detected from magnetar SGR 1806-20. The initial spike was followed by a
hard-X-ray tail persisting for 380 s with a modulation period of 7.56 s. This
event has received considerable attention, particularly in the astrophysics
area. Its relevance to the geophysics community lies in the importance of
investigating the effects of such an event on the near-earth electromagnetic
environment. However, the signature of a magnetar flare on the geomagnetic
field has not previously been investigated. Here, by applying wavelet analysis
to the high-resolution magnetic data provided by the CHAMP satellite, a
modulated signal with a period of 7.5 s over the duration of the giant flare
appears in the observed data. Moreover, this event was detected by the
energetic ion counters onboard the DEMETER satellite.


title:
Fermion loop simulations in 2--d lattice theories -- results and
  limitations

abstract:
  We review our results for the simulation of the 2--d lattice Gross--Neveu
model in a fermion loop representation. Possible extensions of our techniques
to other models and higher dimensions are discussed, as well as the limitations
of loop--type representations.


title: Charmonium properties in the quark-gluon plasma

abstract:
  We present results for charmonium correlators and spectral functions in
2-flavour CD on anisotropic lattices. Our results indicate that the S-waves
(J/psi and eta_c) survive up to temperatures close to 2T_c, while the P-waves
(chi_c0 and chi_c1) melt away below 1.2T_c.


title: On the Limitations of the Color Dipole Picture

abstract:
  We discuss two aspects of the color dipole picture of high energy
photon-proton scattering. First we present bounds on various ratios of deep
inelastic structure functions resulting from the dipole picture that, together
with the measured data, can be used to restrict the kinematical range of its
applicability. The second issue that we address is the choice of energy
variable in the dipole-proton cross section.


title: Unparticles and holography

abstract:
  We construct the holographic dual theory of unparticles. The Randall-Sundrum
type hard wall model is shown to produce deconstructing particles, whose
spectrum has a finite mass gap proportional to the inverse of the fifth
direction segment. The introduction of new scale corresponds to setting a brane
in ${\rm AdS}_5$. The broken conformal symmetry due to this brane is restored
when it is moved to infinity. Unparticles then emerge as an infinite tower of
massless particles.


title:
A common integrable structure in the hermitian matrix model and
  Hele-Shaw flows

abstract:
  It is proved that the system of string equations of the dispersionless 2-Toda
hierarchy which arises in the planar limit of the hermitian matrix model also
underlies certain processes in Hele-Shaw flows.


title:
Study of the topological vacuum structure of SU(2) gluodynamics at T > 0
  with overlap fermions and improved action

abstract:
  We study SU(2) gluodynamics at finite temperature near the deconfining phase
transition. We create the lattice ensembles using the tadpole improved
Luscher-Weisz action. The overlap Dirac operator is used to determine the
following three aspects of vacuum structure: (i) The topological susceptibility
is evaluated at various temperatures across the phase transition, (ii) the
overlap fermion spectral density is determined and found to depend on the
Polyakov loop above the phase transition and (iii) the corresponding
localization properties of low lying eigenmodes are investigated.


title:
A weight two phenomenon for the moduli of rank one local systems on open
  varieties

abstract:
  The twistor space of representations on an open variety maps to a weight two
space of local monodromy transformations around a divisor component at infinty.
The space of $\sigma$-invariant sections of this slope-two bundle over the
twistor line is a real 3 dimensional space whose parameters correspond to the
complex residue of the Higgs field, and the real parabolic weight of a harmonic
bundle.


title: Multi-Gap Superconductivity in MgB2: Magneto-Raman Spectroscopy

abstract:
  Electronic Raman scattering studies on MgB2 single crystals as a function of
excitation and polarization have revealed three distinct superconducting
features: a clean gap below 37 cm-1 and two coherence peaks at 109 cm-1 and 78
cm-1 which we identify as the superconducting gaps in \pi- and \sigma-bands and
as the Leggett's collective mode arising from the fluctuation in the relative
phase between two superconducting condensates residing on corresponding bands.
The temperature and field dependencies of the superconducting features have
been established. A phononic Raman scattering study of the E2g boron stretching
mode anharmonicity and of superconductivity induced self-energy effects is
presented. We show that anharmonic two phonon decay is mainly responsible for
the unusually large linewidth of the E2g mode. We observe ~2.5% hardening of
the E2g phonon frequency upon cooling into the superconducting state and
estimate the electron-phonon coupling strength associated with this
renormalization.


title:
Investigation of Strongly Correlated Electron Systems with Cellular
  Dynamical Mean Field Theory

abstract:
  In this thesis we study the strongly-correlated-electron physics of the
longstanding H-Tc-superconductivity problem using a non-perturbative method,
the Dynamical Mean Field Theory (DMFT), capable to go beyond standard
perturbation-theory techniques. DMFT is by construction a local theory which
neglects spatial correlation. Experiments have however shown that the latter is
a fundamental property of cuprate materials. In a first step, we approach the
problem of spatial correlation in the normal state of cuprate materials using a
phenomenological Fermi-Liquid-Boltzmann model. We then introduce and develop in
detail an extension to DMFT, the Cellular Dynamical Mean Field Theory (CDMFT),
capable of considering short-ranged spatial correlation in a system, and we
implement it using the exact diagonalization algorithm . After benchmarking
CDMFT with the exact one-dimensional solution of the Hubbard Model, we employ
it to study the density-driven Mott metal-insulator transition in the
two-dimensional Hubbard Model, focusing in particular on the anomalous
properties of the doped normal state close to the Mott insulator. We finally
study the superconducting state. We show that within CDMFT the one-band Hubbard
Model supports a d-wave superconductive state, which strongly departs from the
standard BCS theory. We conjecture a link between the instabilities found in
the normal state and the onset of superconductivity.


title:
Observation of Leggett's collective mode in a multi-band MgB2
  superconductor

abstract:
  We report observation of Leggett's collective mode in a multi-band MgB2
superconductor with T_c=39K arising from the fluctuations in the relative phase
between two superconducting condensates. The novel mode is observed by Raman
spectroscopy at 9.4 meV in the fully symmetric scattering channel. The observed
mode frequency is consistent with theoretical considerations based on the first
principle computations.


title: Inelastic soliton processes generated by the perturbed KdV equation

abstract:
  Perturbations commonly added to the KdV equation contain terms that represent
inelastic interac-tions among KdV solitons in multiple-soliton solutions. These
terms trigger the emergence of new waves in the first-order correction to the
solution of the perturbed equation. The new waves can represent
soliton-anti-soliton creation, annihilation and scattering. Other possible
waves represent soliton decay and production.


title: Nouvelle analyse des ph\'enom\`enes vibratoires en tournage

abstract:
  In the cutting process, machine-tools vibrations are generally a real problem
when the amplitude crosses the limits of dimensional or surface quality
workpiece precision required. It is necessary to develop models taking into
account the three-dimensional vibratory approach to control the vibrations
phenomena. An experimental study has been realized to understand the behavior
of the cutting system and to identify its vibrations properties. The
displacement's localization of the tool in a spatial plan, showed by the
experimental results, allows us to simplify the three-dimensional dynamical
model. In this study, the experimental approach is completely presented and the
first points of the three dimensional vibratory model are proposed according to
the experimental results.


title:
Direct measurement of the coherence length of edge states in the Integer
  Quantum Hall Regime

abstract:
  We have determined the finite temperature coherence length of edge states in
the Integer Quantum Hall Effect (IQHE) regime. This was realized by measuring
the visibility of electronic Mach-Zehnder interferometers of different sizes,
at filling factor 2. The visibility shows an exponential decay with the
temperature. The characteristic temperature scale is found inversely
proportional to the length of the interferometer arm, allowing to define a
coherence length $\l_\phi$. The variations of $\l_\phi$ with magnetic field are
the same for all samples, with a maximum located at the upper end of the
quantum hall plateau. Our results provide the first accurate determination of
$\l_\phi$ in the quantum Hall regime.


title: Metal-rich debris discs around white dwarfs

abstract:
  We have identified two moderately hot (~18000-22000K) white dwarfs,
SDSSJ1228+1040 and SDSSJ1043+0855, which exhibit double-peaked emission lines
in the CaII 8600A triplet. These line profiles are unambiguous signatures of
gaseous discs with outer radii of ~1Rsun orbiting the two white dwarfs. Both
stars accrete from the circumstellar material, resulting in large photospheric
Mg abundances. The absence of hydrogen emission from the discs, and helium
absorption in the white dwarf photospheres demonstrates that the circumstellar
material is depleted in volatile elements, and the most likely origin of these
gaseous rings are tidally disrupted rocky asteroids. The relatively high mass
of SDSSJ1228+1040 implies that planetary systems can not only form around
4-5Msun stars, but may also survive their post main-sequence evolution.


title:
Identification of specificity determining residues in enzymes using
  environment specific substitution tables

abstract:
  Environment specific substitution tables have been used effectively for
distinguishing structural and functional constraints on proteins and thereby
identify their active sites (Chelliah et al. (2004)). This work explores
whether a similar approach can be used to identify specificity determining
residues (SDRs) responsible for cofactor dependence, substrate specificity or
subtle catalytic variations. We combine structure-sequence information and
functional annotation from various data sources to create structural alignments
for homologous enzymes and functional partitions therein. We develop a scoring
procedure to predict SDRs and assess their accuracy using information from
bound specific ligands and published literature.


title: Rescuing H -> bb in VBF at the LHC by requiring a central photon

abstract:
  The LHC potential for a measurement of the Higgs boson coupling to the b
quark in the standard model is not well established yet. We show that requiring
a large transverse momentum photon in the light Higgs boson production via
vector-boson fusion (with subsequent H->bb decay) could provide a further
handle on the Hbb coupling determination, and on the measurement of the HWW
coupling as well.


title: A note on the mass splitting of K*(892)

abstract:
  Belle Collaboration reported a new observed value of K*-(892) mass by
studying tau --> K_S pi nu_tau decay, which is significantly different from the
current world average value given by Particle Data Group 2006. Motivated by
this new data, we revisit the issue on the K*0(892)-K*+(892) mass splitting.
Our theoretical estimation favors the new measurement by Belle Collaboration.
Therefore further experimental efforts are urgently needed to improve our
understanding of these issues.


title:
Charge disproportionation and collinear magnetic order in the frustrated
  triangular antiferromagnet AgNiO2

abstract:
  We report a high-resolution neutron diffraction study of the crystal and
magnetic structure of the orbitally-degenerate frustrated metallic magnet
AgNiO2. At high temperatures the structure is hexagonal with a single
crystallographic Ni site, low-spin Ni3+ with spin-1/2 and two-fold orbital
degeneracy, arranged in an antiferromagnetic triangular lattice with frustrated
spin and orbital order. A structural transition occurs upon cooling below 365 K
to a tripled hexagonal unit cell containing three crystallographically-distinct
Ni sites with expanded and contracted NiO6 octahedra, naturally explained by
spontaneous charge order on the Ni triangular layers. No Jahn-Teller
distortions occur, suggesting that charge order occurs in order to lift the
orbital degeneracy. Symmetry analysis of the inferred Ni charge order pattern
and the observed oxygen displacement pattern suggests that the transition could
be mediated by charge fluctuations at the Ni sites coupled to a soft oxygen
optical phonon breathing mode. At low temperatures the electron-rich Ni
sublattice (assigned to a valence close to Ni2+ with S = 1) orders magnetically
into a collinear stripe structure of ferromagnetic rows ordered
antiferromagnetically in the triangular planes. We discuss the stability of
this uncommon spin order pattern in the context of an easy-axis triangular
antiferromagnet with additional weak second neighbor interactions and
interlayer couplings.


title:
Ultra-Broadband Radial Polarization Conversion based on Goos-Hanchen
  Shift

abstract:
  We demonstrate, for the first time, a scheme that generates
radially-polarized light using Goos-Hanchen shift of a cylindrically symmetric
Total Internal Reflection. It allows ultra-broadband radial polarization
conversion for wavelengths differing >1 micron.


title:
A Search for Mid-Infrared Molecular Hydrogen Emission from
  Protoplanetary Disks

abstract:
  We observed the Herbig Ae/Be stars UX Ori, HD 34282, HD 100453, HD 101412, HD
104237 and HD 142666, and the T Tauri star HD 319139 and searched for H2 0-0
S(2) emission at 12.278 micron and H2 0-0 S(1) emission at 17.035 micron with
VISIR, ESO-VLT's high-resolution MIR spectrograph. None of the sources present
evidence for H2 emission. Stringent 3sigma upper limits to the integrated line
fluxes and the mass of optically thin warm gas in the disks are derived. The
disks contain less than a few tenths of Jupiter mass of optically thin H2 gas
at 150 K at most, and less than a few Earth masses of optically thin H2 gas at
300 K and higher temperatures. We compare our results to a Chiang and Goldreich
(1997, CG97) two-layer disk model. The upper limits to the disk's optically
thin warm gas mass are smaller than the amount of warm gas in the interior
layer of the disk, but they are much larger than the amount of molecular gas in
the surface layer. We present a calculation of the expected thermal H2 emission
from optically thick disks, assuming a CG97 disk structure, a gas-to-dust ratio
of 100 and Tgas = Tdust. The expected H2 thermal emission fluxes from typical
disks around Herbig Ae/Be stars (10^-16 to 10^-17 erg/s/cm2 at 140 pc) are much
lower than the detection limits of our observations (5*10^-15 erg/s/cm2). H2
emission levels are very sensitive to departures from the thermal coupling
between the molecular gas and dust. Additional sources of heating of gas in the
disk's surface layer could have a major impact on the expected H2 disk
emission. In the observed sources the molecular gas and dust in the surface
layer have not significantly departed from thermal coupling (Tgas/Tdust< 2) and
that the gas-to-dust ratio in the surface layer is very likely lower than 1000.


title:
CO abundances in a protostellar cloud: freeze-out and desorption in the
  envelope and outflow of L483

abstract:
  CO isotopes are able to probe the different components in protostellar
clouds. These components, core, envelope and outflow have distinct physical
conditions and sometimes more than one component contributes to the observed
line profile. In this study we determine how CO isotope abundances are altered
by the physical conditions in the different components. We use a 3D molecular
line transport code to simulate the emission of four CO isotopomers, 12CO
J=2-1, 13CO J=2-1, C18O J=2-1 and C17O J=2-1 from the Class 0/1 object L483,
which contains a cold quiescent core, an infalling envelope and a clear
outflow. Our models replicate JCMT (James Clerk Maxwell Telescope) line
observations with the inclusion of freeze-out, a density profile and infall.
Our model profiles of 12CO and 13CO have a large linewidth due to a high
velocity jet. These profiles replicate the process of more abundant material
being susceptible to a jet. C18O and C17O do not display such a large linewidth
as they trace denser quiescent material deep in the cloud.