title: A new search for planet transits in NGC 6791

abstract:
  Context. Searching for planets in open clusters allows us to study the
effects of dynamical environment on planet formation and evolution.
  Aims. Considering the strong dependence of planet frequency on stellar
metallicity, we studied the metal rich old open cluster NGC 6791 and searched
for close-in planets using the transit technique.
  Methods. A ten-night observational campaign was performed using the
Canada-France-Hawaii Telescope (3.6m), the San Pedro M\'artir telescope (2.1m),
and the Loiano telescope (1.5m). To increase the transit detection probability
we also made use of the Bruntt et al. (2003) eight-nights observational
campaign. Adequate photometric precision for the detection of planetary
transits was achieved.
  Results. Should the frequency and properties of close-in planets in NGC 6791
be similar to those orbiting field stars of similar metallicity, then detailed
simulations foresee the presence of 2-3 transiting planets. Instead, we do not
confirm the transit candidates proposed by Bruntt et al. (2003). The
probability that the null detection is simply due to chance coincidence is
estimated to be 3%-10%, depending on the metallicity assumed for the cluster.
  Conclusions. Possible explanations of the null-detection of transits include:
(i) a lower frequency of close-in planets in star clusters; (ii) a smaller
planetary radius for planets orbiting super metal rich stars; or (iii)
limitations in the basic assumptions. More extensive photometry with 3-4m class
telescopes is required to allow conclusive inferences about the frequency of
planets in NGC 6791.


title: Possible polarisation and spin dependent aspects of quantum gravity

abstract:
  We argue that quantum gravity theories that carry a Lie algebraic
modification of the Poincare' and Heisenberg algebras inevitably provide
inhomogeneities that may serve as seeds for cosmological structure formation.
Furthermore, in this class of theories one must expect a strong polarisation
and spin dependence of various quantum-gravity effects.


title: On the support genus of a contact structure

abstract:
  The algorithm given by Akbulut-Ozbagci constructs an explicit open book
decomposition on a contact three-manifold described by a contact surgery on a
link in the three-sphere. In this article, we will improve this algorithm by
using Giroux's contact cell decomposition process. Our algorithm is more
economical on choosing the supporting genus of the open book; in particular it
gives a good upper bound for the recently defined ``minimal supporting genus
invariant'' of contact structures.


title: Very Massive Stars in High-Redshift Galaxies

abstract:
  A significant fraction of Lyman Alpha (Lya) emitting galaxies (LAEs) at z>
5.7 have rest-frame equivalent widths (EW) greater than ~100 Angstrom. However
only a small fraction of the Lya flux produced by a galaxy is transmitted
through the IGM, which implies intrinsic Lya EWs that are in excess of the
maximum allowed for a population-II stellar population having a Salpeter mass
function. In this paper we study characteristics of the sources powering Lya
emission in high redshift galaxies. We propose a simple model for Lya emitters
in which galaxies undergo a burst of very massive star formation that results
in a large intrinsic EW, followed by a phase of population-II star formation
with a lower EW. We confront this model with a range of high redshift
observations and find that the model is able to simultaneously describe the
following eight properties of the high redshift galaxy population with
plausible values for parameters like the efficiency and duration of star
formation: i-iv) the UV and Lya luminosity functions of LAEs at z=5.7 and 6.5,
v-vi) the mean and variance of the EW distribution of Lya selected galaxies at
z=5.7, vii) the EW distribution of i-drop galaxies at z~6, and viii) the
observed correlation of stellar age with EW. Our modeling suggests that the
observed anomalously large intrinsic equivalent widths require a burst of very
massive star formation lasting no more than a few to ten percent of the
galaxies star forming lifetime. This very massive star formation may indicate
the presence of population-III star formation in a few per cent of i-drop
galaxies, and in about half of the Lya selected galaxies.


title:
Two center multipole expansion method: application to macromolecular
  systems

abstract:
  We propose a new theoretical method for the calculation of the interaction
energy between macromolecular systems at large distances. The method provides a
linear scaling of the computing time with the system size and is considered as
an alternative to the well known fast multipole method. Its efficiency,
accuracy and applicability to macromolecular systems is analyzed and discussed
in detail.


title: Holographic formula for Q-curvature

abstract:
  This paper derives an explicit formula for Branson's Q-curvature in
even-dimensional conformal geometry. The ingredients in the formula come from
the Poincare metric in one higher dimension; hence the formula is called
holographic. When specialized to the conformally flat case, the holographic
formula expresses Q-curvature as a multiple of the Pfaffian and the divergence
of a natural one-form. The paper also outlines the relation between holographic
formulae for Q-curvature and a new theory of conformally covariant families of
differential operators due to the second author.


title: The azimuth structure of nuclear collisions -- I

abstract:
  We describe azimuth structure commonly associated with elliptic and directed
flow in the context of 2D angular autocorrelations for the purpose of precise
separation of so-called nonflow (mainly minijets) from flow. We extend the
Fourier-transform description of azimuth structure to include power spectra and
autocorrelations related by the Wiener-Khintchine theorem. We analyze several
examples of conventional flow analysis in that context and question the
relevance of reaction plane estimation to flow analysis. We introduce the 2D
angular autocorrelation with examples from data analysis and describe a
simulation exercise which demonstrates precise separation of flow and nonflow
using the 2D autocorrelation method. We show that an alternative correlation
measure based on Pearson's normalized covariance provides a more intuitive
measure of azimuth structure.


title: Exploiting Social Annotation for Automatic Resource Discovery

abstract:
  Information integration applications, such as mediators or mashups, that
require access to information resources currently rely on users manually
discovering and integrating them in the application. Manual resource discovery
is a slow process, requiring the user to sift through results obtained via
keyword-based search. Although search methods have advanced to include evidence
from document contents, its metadata and the contents and link structure of the
referring pages, they still do not adequately cover information sources --
often called ``the hidden Web''-- that dynamically generate documents in
response to a query. The recently popular social bookmarking sites, which allow
users to annotate and share metadata about various information sources, provide
rich evidence for resource discovery. In this paper, we describe a
probabilistic model of the user annotation process in a social bookmarking
system del.icio.us. We then use the model to automatically find resources
relevant to a particular information domain. Our experimental results on data
obtained from \emph{del.icio.us} show this approach as a promising method for
helping automate the resource discovery task.


title: Personalizing Image Search Results on Flickr

abstract:
  The social media site Flickr allows users to upload their photos, annotate
them with tags, submit them to groups, and also to form social networks by
adding other users as contacts. Flickr offers multiple ways of browsing or
searching it. One option is tag search, which returns all images tagged with a
specific keyword. If the keyword is ambiguous, e.g., ``beetle'' could mean an
insect or a car, tag search results will include many images that are not
relevant to the sense the user had in mind when executing the query. We claim
that users express their photography interests through the metadata they add in
the form of contacts and image annotations. We show how to exploit this
metadata to personalize search results for the user, thereby improving search
performance. First, we show that we can significantly improve search precision
by filtering tag search results by user's contacts or a larger social network
that includes those contact's contacts. Secondly, we describe a probabilistic
model that takes advantage of tag information to discover latent topics
contained in the search results. The users' interests can similarly be
described by the tags they used for annotating their images. The latent topics
found by the model are then used to personalize search results by finding
images on topics that are of interest to the user.


title: Resummed Cross Section for Jet Production at Hadron Colliders

abstract:
  We study the resummation of large logarithmic perturbative corrections to the
single-inclusive jet cross section at hadron colliders. The corrections we
address arise near the threshold for the partonic reaction, when the incoming
partons have just enough energy to produce the high-transverse-momentum final
state. The structure of the resulting logarithmic corrections is known to
depend crucially on the treatment of the invariant mass of the produced jet at
threshold. We allow the jet to have a non-vanishing mass at threshold, which
most closely corresponds to the situation in experiment. Matching our results
to available semi-analytical next-to-leading-order calculations, we derive
resummed results valid to next-to-leading logarithmic accuracy. We present
numerical results for the resummation effects at Tevatron and RHIC energies.


title: Settling the Complexity of Computing Two-Player Nash Equilibria

abstract:
  We settle a long-standing open question in algorithmic game theory. We prove
that Bimatrix, the problem of finding a Nash equilibrium in a two-player game,
is complete for the complexity class PPAD Polynomial Parity Argument, Directed
version) introduced by Papadimitriou in 1991.
  This is the first of a series of results concerning the complexity of Nash
equilibria. In particular, we prove the following theorems:
  Bimatrix does not have a fully polynomial-time approximation scheme unless
every problem in PPAD is solvable in polynomial time. The smoothed complexity
of the classic Lemke-Howson algorithm and, in fact, of any algorithm for
Bimatrix is not polynomial unless every problem in PPAD is solvable in
randomized polynomial time. Our results demonstrate that, even in the simplest
form of non-cooperative games, equilibrium computation and approximation are
polynomial-time equivalent to fixed point computation. Our results also have
two broad complexity implications in mathematical economics and operations
research: Arrow-Debreu market equilibria are PPAD-hard to compute. The P-Matrix
Linear Complementary Problem is computationally harder than convex programming
unless every problem in PPAD is solvable in polynomial time.


title:
Equation of State in Relativistic Magnetohydrodynamics: variable versus
  constant adiabatic index

abstract:
  The role of the equation of state for a perfectly conducting, relativistic
magnetized fluid is the main subject of this work. The ideal constant
$\Gamma$-law equation of state, commonly adopted in a wide range of
astrophysical applications, is compared with a more realistic equation of state
that better approximates the single-specie relativistic gas. The paper focus on
three different topics. First, the influence of a more realistic equation of
state on the propagation of fast magneto-sonic shocks is investigated. This
calls into question the validity of the constant $\Gamma$-law equation of state
in problems where the temperature of the gas substantially changes across
hydromagnetic waves. Second, we present a new inversion scheme to recover
primitive variables (such as rest-mass density and pressure) from conservative
ones that allows for a general equation of state and avoids catastrophic
numerical cancellations in the non-relativistic and ultrarelativistic limits.
Finally, selected numerical tests of astrophysical relevance (including
magnetized accretion flows around Kerr black holes) are compared using
different equations of state. Our main conclusion is that the choice of a
realistic equation of state can considerably bear upon the solution when
transitions from cold to hot gas (or viceversa) are present. Under these
circumstances, a polytropic equation of state can significantly endanger the
solution.


title:
Carbon Nanotube Thin Film Field Emitting Diode: Understanding the System
  Response Based on Multiphysics Modeling

abstract:
  In this paper, we model the evolution and self-assembly of randomly oriented
carbon nanotubes (CNTs), grown on a metallic substrate in the form of a thin
film for field emission under diode configuration. Despite high output, the
current in such a thin film device often decays drastically. The present paper
is focused on understanding this problem. A systematic, multiphysics based
modelling approach is proposed. First, a nucleation coupled model for
degradation of the CNT thin film is derived, where the CNTs are assumed to
decay by fragmentation and formation of clusters. The random orientation of the
CNTs and the electromechanical interaction are then modeled to explain the
self-assembly. The degraded state of the CNTs and the electromechanical force
are employed to update the orientation of the CNTs. Field emission current at
the device scale is finally obtained by using the Fowler-Nordheim equation and
integration over the computational cell surfaces on the anode side. The
simulated results are in close agreement with the experimental results. Based
on the developed model, numerical simulations aimed at understanding the
effects of various geometric parameters and their statistical features on the
device current history are reported.


title: Demographics of Transition Objects

abstract:
  The unusual properties of transition objects (young stars with an optically
thin inner disc surrounded by an optically thick outer disc) suggest that
significant disc evolution has occured in these systems. We explore the nature
of these systems by examining their demographics, specifically their stellar
accretion rates (Mdot) and disc masses (Mdisc) compared to those of accreting T
Tauri stars of comparable age. We find that transition objects in Taurus occupy
a restricted region of the Mdot vs. Mdisc plane. Compared to non-transition
single stars in Taurus, they have stellar accretion rates that are typically
~10 times lower at the same disc mass and median disc masses ~4 times larger.
These properties are anticipated by several proposed planet formation theories
and suggest that the formation of Jovian mass planets may play a significant
role in explaining the origin of at least some transition objects. Considering
transition objects as a distinct demographic group among accreting T Tauri
stars leads to a tighter relationship between disc masses and stellar accretion
rates, with a slope between the two quantities that is close to the value of
unity expected in simple theories of disc accretion.


title:
Modeling the Field Emission Current Fluctuation in Carbon Nanotube Thin
  Films

abstract:
  Owing to their distinct properties, carbon nanotubes (CNTs) have emerged as
promising candidate for field emission devices. It has been found
experimentally that the results related to the field emission performance show
variability. The design of an efficient field emitting device requires the
analysis of the variabilities with a systematic and multiphysics based modeling
approach. In this paper, we develop a model of randomly oriented CNTs in a thin
film by coupling the field emission phenomena, the electron-phonon transport
and the mechanics of single isolated CNT. A computational scheme is developed
by which the states of CNTs are updated in time incremental manner. The device
current is calculated by using Fowler-Nordheim equation for field emission to
study the performance at the device scale.


title: Spectral averaging for trace compatible operators

abstract:
  In this note the notions of trace compatible operators and infinitesimal
spectral flow are introduced. We define the spectral shift function as the
integral of infinitesimal spectral flow. It is proved that the spectral shift
function thus defined is absolutely continuous and Krein's formula is
established. Some examples of trace compatible affine spaces of operators are
given.


title:
The molecular environment of massive star forming cores associated with
  Class II methanol maser emission

abstract:
  Methanol maser emission has proven to be an excellent signpost of regions
undergoing massive star formation (MSF). To investigate their role as an
evolutionary tracer, we have recently completed a large observing program with
the ATCA to derive the dynamical and physical properties of molecular/ionised
gas towards a sample of MSF regions traced by 6.7 GHz methanol maser emission.
We find that the molecular gas in many of these regions breaks up into multiple
sub-clumps which we separate into groups based on their association
with/without methanol maser and cm continuum emission. The temperature and
dynamic state of the molecular gas is markedly different between the groups.
Based on these differences, we attempt to assess the evolutionary state of the
cores in the groups and thus investigate the role of class II methanol masers
as a tracer of MSF.


title: Gravitating Global k-monopole

abstract:
  A gravitating global k-monopole produces a tiny gravitational field outside
the core in addition to a solid angular deficit in the k-field theory. As a new
feature, the gravitational field can be attractive or repulsive depending on
the non-canonical kinetic term.


title:
Effect of atomic beam alignment on photon correlation measurements in
  cavity QED

abstract:
  Quantum trajectory simulations of a cavity QED system comprising an atomic
beam traversing a standing-wave cavity are carried out. The delayed photon
coincident rate for forwards scattering is computed and compared with the
measurements of Rempe et al. [Phys. Rev. Lett. 67, 1727 (1991)] and Foster et
al. [Phys. Rev. A 61, 053821 (2000)]. It is shown that a moderate atomic beam
misalignment can account for the degradation of the predicted correlation. Fits
to the experimental data are made in the weak-field limit with a single
adjustable parameter--the atomic beam tilt from perpendicular to the cavity
axis. Departures of the measurement conditions from the weak-field limit are
discussed.


title:
Studies on optimizing potential energy functions for maximal intrinsic
  hyperpolarizability

abstract:
  We use numerical optimization to study the properties of (1) the class of
one-dimensional potential energy functions and (2) systems of point charges in
two-dimensions that yield the largest hyperpolarizabilities, which we find to
be within 30% of the fundamental limit. We investigate the character of the
potential energy functions and resulting wavefunctions and find that a broad
range of potentials yield the same intrinsic hyperpolarizability ceiling of
0.709.


title:
Critical test for Altshuler-Aronov theory: Evolution of the density of
  states singularity in double perovskite Sr$_2$FeMoO$_6$ with controlled
  disorder

abstract:
  With high-resolution photoemission spectroscopy measurements, the density of
states (DOS) near the Fermi level ($E_\mathrm{F}$) of double perovskite
Sr$_2$FeMoO$_6$ having different degrees of Fe/Mo antisite disorder has been
investigated with varying temperature. The DOS near $E_\mathrm{F}$ showed a
systematic depletion with increasing degree of disorder, and recovered with
increasing temperature. Altshuler-Aronov (AA) theory of disordered metals well
explains the dependences of the experimental results. Scaling analysis of the
spectra provides experimental indication for the functional form of the AA DOS
singularity.


title: Some Properties of and Open Problems on Hessian Nilpotent Polynomials

abstract:
  In the recent progress [BE1], [M], [Z1] and [Z2], the well-known Jacobian
conjecture ([BCW], [E]) has been reduced to a problem on HN (Hessian nilpotent)
polynomials (the polynomials whose Hessian matrix are nilpotent) and their
(deformed) inversion pairs. In this paper, we prove several results on HN
polynomials, their (deformed) inversion pairs as well as the associated
symmetric polynomial or formal maps. We also propose some open problems for
further study of these objects.


title: Two Results on Homogeneous Hessian Nilpotent Polynomials

abstract:
  Let $z=(z_1, ..., z_n)$ and $\Delta=\sum_{i=1}^n \frac {\partial^2}{\partial
z^2_i}$ the Laplace operator. A formal power series $P(z)$ is said to be {\it
Hessian Nilpotent}(HN) if its Hessian matrix $\Hes P(z)=(\frac {\partial^2
P}{\partial z_i\partial z_j})$ is nilpotent. In recent developments in [BE1],
[M] and [Z], the Jacobian conjecture has been reduced to the following
so-called {\it vanishing conjecture}(VC) of HN polynomials: {\it for any
homogeneous HN polynomial $P(z)$ $($of degree $d=4$$)$, we have $\Delta^m
P^{m+1}(z)=0$ for any $m>>0$.} In this paper, we first show that, the VC holds
for any homogeneous HN polynomial $P(z)$ provided that the projective
subvarieties ${\mathcal Z}_P$ and ${\mathcal Z}_{\sigma_2}$ of $\mathbb C
P^{n-1}$ determined by the principal ideals generated by $P(z)$ and
$\sigma_2(z):=\sum_{i=1}^n z_i^2$, respectively, intersect only at regular
points of ${\mathcal Z}_P$. Consequently, the Jacobian conjecture holds for the
symmetric polynomial maps $F=z-\nabla P$ with $P(z)$ HN if $F$ has no non-zero
fixed point $w\in \mathbb C^n$ with $\sum_{i=1}^n w_i^2=0$. Secondly, we show
that the VC holds for a HN formal power series $P(z)$ if and only if, for any
polynomial $f(z)$, $\Delta^m (f(z)P(z)^m)=0$ when $m>>0$.


title:
A Vanishing Conjecture on Differential Operators with Constant
  Coefficients

abstract:
  In the recent progress [BE1], [Me] and [Z2], the well-known JC (Jacobian
conjecture) ([BCW], [E]) has been reduced to a VC (vanishing conjecture) on the
Laplace operators and HN (Hessian nilpotent) polynomials (the polynomials whose
Hessian matrix are nilpotent). In this paper, we first show that the vanishing
conjecture above, hence also the JC, is equivalent to a vanishing conjecture
for all 2nd order homogeneous differential operators $\Lambda$ and
$\Lambda$-nilpotent polynomials $P$ (the polynomials $P(z)$ satisfying
$\Lambda^m P^m=0$ for all $m\ge 1$). We then transform some results in the
literature on the JC, HN polynomials and the VC of the Laplace operators to
certain results on $\Lambda$-nilpotent polynomials and the associated VC for
2nd order homogeneous differential operators $\Lambda$. This part of the paper
can also be read as a short survey on HN polynomials and the associated VC in
the more general setting. Finally, we discuss a still-to-be-understood
connection of $\Lambda$-nilpotent polynomials in general with the classical
orthogonal polynomials in one or more variables. This connection provides a
conceptual understanding for the isotropic properties of homogeneous
$\Lambda$-nilpotent polynomials for the 2nd order homogeneous full rank
differential operators $\Lambda$ with constant coefficients.


title:
Effects of accelerating growth on the evolution of weighted complex
  networks

abstract:
  Many real systems possess accelerating statistics where the total number of
edges grows faster than the network size. In this paper, we propose a simple
weighted network model with accelerating growth. We derive analytical
expressions for the evolutions and distributions for strength, degree, and
weight, which are relevant to accelerating growth. We also find that
accelerating growth determines the clustering coefficient of the networks.
Interestingly, the distributions for strength, degree, and weight display a
transition from scale-free to exponential form when the parameter with respect
to accelerating growth increases from a small to large value. All the
theoretical predictions are successfully contrasted with extensive numerical
simulations.


title: N_p N_n Scheme Based on New Empirical Formula for Excitation Energy

abstract:
  We examine the $N_p N_n$ scheme based on a recently proposed simple empirical
formula which is highly valid for the excitation energy of the first excited
natural parity even multipole states in even-even nuclei. We demonstrate
explicitly that the $N_p N_n$ scheme for the excitation energy emerges from the
separate exponential dependence of the excitation energy on the valence nucleon
numbers $N_p$ and $N_n$ together with the fact that only a limited set of
numbers is allowed for the $N_p$ and $N_n$ of the existing nuclei.


title:
Locally Decodable Codes From Nice Subsets of Finite Fields and Prime
  Factors of Mersenne Numbers

abstract:
  A k-query Locally Decodable Code (LDC) encodes an n-bit message x as an N-bit
codeword C(x), such that one can probabilistically recover any bit x_i of the
message by querying only k bits of the codeword C(x), even after some constant
fraction of codeword bits has been corrupted. The major goal of LDC related
research is to establish the optimal trade-off between length and query
complexity of such codes.
  Recently [Y] introduced a novel technique for constructing locally decodable
codes and vastly improved the upper bounds for code length. The technique is
based on Mersenne primes. In this paper we extend the work of [Y] and argue
that further progress via these methods is tied to progress on an old number
theory question regarding the size of the largest prime factors of Mersenne
numbers.
  Specifically, we show that every Mersenne number m=2^t-1 that has a prime
factor p>m^\gamma yields a family of k(\gamma)-query locally decodable codes of
length Exp(n^{1/t}). Conversely, if for some fixed k and all \epsilon > 0 one
can use the technique of [Y] to obtain a family of k-query LDCs of length
Exp(n^\epsilon); then infinitely many Mersenne numbers have prime factors arger
than known currently.


title: Pair production with neutrinos in an intense background magnetic field

abstract:
  We present a detailed calculation of the electron-positron production rate
using neutrinos in an intense background magnetic field. The computation is
done for the process nu -> nu e- e+ (where nu can be nu_e, nu_mu, or nu_tau)
within the framework of the Standard Model. Results are given for various
combinations of Landau-levels over a range of possible incoming neutrino
energies and magnetic field strengths.


title: Theoretical Aspects of the SOM Algorithm

abstract:
  The SOM algorithm is very astonishing. On the one hand, it is very simple to
write down and to simulate, its practical properties are clear and easy to
observe. But, on the other hand, its theoretical properties still remain
without proof in the general case, despite the great efforts of several
authors. In this paper, we pass in review the last results and provide some
conjectures for the future work.


title:
Effect of the Spatial Dispersion on the Shape of a Light Pulse in a
  Quantum Well

abstract:
  Reflectance, transmittance and absorbance of a symmetric light pulse, the
carrying frequency of which is close to the frequency of interband transitions
in a quantum well, are calculated. Energy levels of the quantum well are
assumed discrete, and two closely located excited levels are taken into
account. A wide quantum well (the width of which is comparable to the length of
the light wave, corresponding to the pulse carrying frequency) is considered,
and the dependance of the interband matrix element of the momentum operator on
the light wave vector is taken into account. Refractive indices of barriers and
quantum well are assumed equal each other. The problem is solved for an
arbitrary ratio of radiative and nonradiative lifetimes of electronic
excitations. It is shown that the spatial dispersion essentially affects the
shapes of reflected and transmitted pulses. The largest changes occur when the
radiative broadening is close to the difference of frequencies of interband
transitions taken into account.


title:
The origin of the anomalously strong influence of out-of-plane disorder
  on high-Tc superconductivity

abstract:
  The electronic structure of Bi2Sr2-xRxCuOy(R=La, Eu) near the (pi,0) point of
the first Brillouin zone was studied by means of angle-resolved photoemission
spectroscopy (ARPES). The temperature T* above which the pseudogap structure in
the ARPES spectrum disappears was found to have an R dependence that is
opposite to that ofthe superconducting transition temperature Tc. This
indicates that the pseudogap state is competing with high-Tc superconductivity,
and the large Tc suppression observed with increasing the out-of-plane disorder
is due to the stabilization of the pseudogap state.


title: Relativistic Hydrodynamics at RHIC and LHC

abstract:
  Recent development of a hydrodynamic model is discussed by putting an
emphasis on realistic treatment of the early and late stages in relativistic
heavy ion collisions. The model, which incorporates a hydrodynamic description
of the quark-gluon plasma with a kinetic approach of hadron cascades, is
applied to analysis of elliptic flow data at the Relativistic Heavy Ion
Collider energy. It is predicted that the elliptic flow parameter based on the
hybrid model increases with the collision energy up to the Large Hadron
Collider energy.


title: Retract rationality and Noether's problem

abstract:
  Let K be any field and G be a finite group. We will prove that, if K is any
field, p an odd prime number, and G is a non-abelian group of exponent p with
|G|=p^3 or p^4 satisfying [K(\zeta_p):K] <= 2, then K(G) is rational over K. We
will also show that K(G) is retract rational if G belongs to a much larger
class of p-groups. In particular, generic G-polynomials of G-Galois extensions
exist for these groups.


title: Noether's problem for some p-groups

abstract:
  Let K be any field and G be a finite group. Noether's problem asks whether
the fixed field is rational (=purely transcendental) over K. We will prove that
if G is a non-abelian p-group of order p^n containing a cyclic subgroup of
index p and K is any field containing a primitive p^{n-2}-th root of unity,
then K(G) is rational over K.


title: The canonical volume of threefolds of general type with $\chi<1$

abstract:
  We prove that the canonical volume $K^3\geq {1/30}$ for all projective
3-folds of general type with $\chi(\mathcal{O})\leq 0$. This bound is sharp.


title:
Very High Energy Gamma Rays from Supernova Remnants and Constraints on
  the Galactic Interstellar Radiation Field

abstract:
  The large-scale Galactic interstellar radiation field (ISRF) is the result of
stellar emission and dust re-processing of starlight. Where the energy density
of the ISRF is high (e.g., the Galactic Centre), the dominant gamma-ray
emission in individual supernova remnants (SNRs), such as G0.9+0.1, may come
from inverse Compton (IC) scattering of the ISRF. Several models of the ISRF
exist. The most recent one, which has been calculated by us, predicts a
significantly higher ISRF than the well-used model of Mathis, Mezger, and
Panagia. However,comparison with data is limited to local observations. Based
on our current estimate of the ISRF we predict the gamma-ray emission in the
SNRs G0.9+0.1 and RXJ1713, and pair-production absorption features above 20 TeV
in the spectra of G0.9+0.1, J1713-381, and J1634-472. We discuss how GLAST,
along with current and future very high energy instruments, may be able to
provide upper bounds on the large-scale ISRF.


title:
Magneto-oscillations due to electron-electron interactions in the ac
  conductivity of a 2D electron gas

abstract:
  Electron-electron interactions give rise to the correction,
\delta\sigma^{int}(\omega), to the ac magnetoconductivity, \sigma(\omega), of a
clean 2D electron gas that is periodic in \omega_c^{-1}, where \omega_c is the
cyclotron frequency. Unlike conventional harmonics of the cyclotron resonance,
which are periodic with \omega, this correction is periodic with \omega^{3/2}.
Oscillations in \delta\sigma^{int}(\omega) develop at low magnetic fields,
\omega_c\ll\omega, when the conventional harmonics are suppressed by the
disorder. Their origin is a {\em double} backscattering of an electron from the
impurity-induced Friedel oscillations. During the time \sim\omega^{-1} between
the two backscattering events the electron travels only a {\em small portion}
of the Larmour circle.


title: Optimal fluctuation approach to a directed polymer in a random medium

abstract:
  A modification of the optimal fluctuation approach is applied to study the
tails of the free energy distribution function P(F) for an elastic string in
quenched disorder both in the regions of the universal behavior of P(F) and in
the regions of large fluctuations, where the behavior of P(F) is non-universal.
The difference between the two regimes is shown to consist in whether it is
necessary or not to take into account the renormalization of parameters by the
fluctuations of disorder in the vicinity of the optimal fluctuation.


title:
Implementation of a Gauss convoluted Pandel PDF for track reconstruction
  in Neutrino Telescopes

abstract:
  A probability distribution function is presented which provides a realistic
description of the detection of scattered photons. The resulting probabilities
can be described analytically by means of a superposition of several special
functions. These exact expressions can be evaluated numerically only for small
distances and limited time residuals, due to computer accuracy limitations. In
this report we provide approximations for the exact expressions in different
regions of the distance-time residual space, defined by the detector geometry
and the space-time scale of an event. These approximations can be evaluated
numerically with a relative error with respect to the exact expression at the
boundaries of less than 0.001.


title:
A Cut-free Sequent Calculus for Bi-Intuitionistic Logic: Extended
  Version

abstract:
  Bi-intuitionistic logic is the extension of intuitionistic logic with a
connective dual to implication. Bi-intuitionistic logic was introduced by
Rauszer as a Hilbert calculus with algebraic and Kripke semantics. But her
subsequent ``cut-free'' sequent calculus for BiInt has recently been shown by
Uustalu to fail cut-elimination. We present a new cut-free sequent calculus for
BiInt, and prove it sound and complete with respect to its Kripke semantics.
Ensuring completeness is complicated by the interaction between implication and
its dual, similarly to future and past modalities in tense logic. Our calculus
handles this interaction using extended sequents which pass information from
premises to conclusions using variables instantiated at the leaves of failed
derivation trees. Our simple termination argument allows our calculus to be
used for automated deduction, although this is not its main purpose.


title:
From virtual work principle to least action principle for stochastic
  dynamics

abstract:
  After the justification of the maximum entropy principle for equilibrium
mechanical system from the principle of virtual work, i.e., the virtual work of
microscopic forces on the elements of a mechanical system vanishes in
thermodynamic equilibrium, we present in this paper an application of the same
principle to dynamical systems out of equilibrium. The aim of this work is to
justify a least action principle and the concurrent maximum path entropy
principle for nonequilibrium thermodynamic systems.


title: Traitement Des Donnees Manquantes Au Moyen De L'Algorithme De Kohonen

abstract:
  Nous montrons comment il est possible d'utiliser l'algorithme d'auto
organisation de Kohonen pour traiter des donn\'ees avec valeurs manquantes et
estimer ces derni\`eres. Apr\`es un rappel m\'ethodologique, nous illustrons
notre propos \`a partir de trois applications \`a des donn\'ees r\'eelles.
  -----
  We show how it is possible to use the Kohonen self-organizing algorithm to
deal with data which contain missing values and to estimate them. After a
methodological recall, we illustrate our purpose from three real databases
applications.


title:
Further Analysis of Excitations of Quarks at Finite Temperature -- Mass
  Effect and Pole Structure --

abstract:
  We calculate the spectral function of the massive quark at finite temperature
(T) using a Yukawa model and show that the peak in the negative energy region
among the three-peaks found in a previous work for the massless quark is
largely suppressed. To explore the underlying mechanism of this behavior, we
also investigate the pole structure of the retarded Green function of the
quark. We will show the result only for the massless quark. We find the
residues of the poles corresponding the three-peaks are all comparable at
$T\sim m_b$. We also show that the multi-peak structure of the quark spectra is
well described in the pole approximation which indicates that the quasi-paricle
picture is valid in this $T$ region.


title:
Dynamical Equilibrium, trajectories study in an economical system. The
  case of the labor market

abstract:
  The paper deals with the study of labor market dynamics, and aims to
characterize its equilibriums and possible trajectories. The theoretical
background is the theory of the segmented labor market. The main idea is that
this theory is well adapted to interpret the observed trajectories, due to the
heterogeneity of the work situations.


title: Borromean Entanglement Revisited

abstract:
  An interesting analogy between quantum entangled states and topological links
was suggested by Aravind. In particular, he emphasized a connection between the
Greenberger-Horne-Zeilinger (GHZ) state and the Borromean rings. However, he
made the connection in a way that depends on the choice of measurement basis.
We reconsider it in a basis-independent way by using the reduced density
matrix.


title: An SiO Maser Search off the Galactic Plane

abstract:
  We have searched for the SiO J=1--0 v= 1 and 2 maser lines at ~ 43 GHz in 277
2MASS/MSX/IRAS sources off the Galactic plane (|b|> 3 deg), which resulted in
119 (112 new) detections. Among the new detections, are two very faint objects
with MSX 12 micron flux densities below 2 Jy. These are likely to be O-rich
AGB-stars associated with dwarf-galaxy tidal tails. The sample also includes
medium bright MSX objects at moderately high Galactic latitudes (3 deg<|b|<5
deg) and in the IRAS gap at higher latitudes. A signature of a warp of the
inner Galactic disk is found for a disk subsample. This warp appears relatively
strongly in the area of 0<l<45 deg and 3<|b|<5 deg. We also found a group of
stars that does not follow to the Galactic rotation. This feature appears in
the Galactic disk at l~ 27 deg, and extends more than 15 deg in Galactic
latitude, like a stream of tidal debris from a dwarf galaxy.


title: Dislocation Dynamics in a Crystal Lattice (Peierls-Nabarro) Relief

abstract:
  The theory of the dislocation motion in the periodic potential relief of the
crystal lattice (the Peierls-Nabarro barriers) is reviewed. On the basis of the
kink mechanism the temperature dependence of the flow stress is described for a
wide class of materials. The theory of quantum mechanical dislocation
tunnelling through the Peierls-Nabarro barriers is extended and compared with
experimental data on the plasticity of alkali halides, BCC and HCP metals at
low temperatures. The behavior of the flow stress at the range of athermic
anomalies is modeled by changing the mechanism of the dislocation motion from
the thermally activated hopping over the barriers to the quantum tunnelling
through them. Some results of previous calculations are represented in a more
explicit convenient for applications form. The pronounced effect of the
switching between the normal and the superconducting states on the flow stress
of metals is explained on the basis of the change in the dissipative properties
of the electron subsystem affecting the dislocation motion.


title: Spectrum of cosmic rays, produced in supernova remnants

abstract:
  Nonlinear kinetic theory of cosmic ray (CR) acceleration in supernova
remnants is employed to calculate CR spectra. The magnetic field in SNRs is
assumed to be significantly amplified by the efficiently accelerating nuclear
CR component. It is shown that the calculated CR spectra agree in a
satisfactory way with the existing measurements up to the energy $10^{17}$ eV.
The power law spectrum of protons extends up to the energy $3\times 10^{15}$ eV
with a subsequent exponential cutoff. It gives a natural explanation for the
observed knee in the Galactic CR spectrum. The maximum energy of the
accelerated nuclei is proportional to their charge number $Z$. Therefore the
break in the Galactic CR spectrum is the result of the contribution of
progressively heavier species in the overall CR spectrum so that at $10^{17}$
eV the CR spectrum is dominated by iron group nuclei. It is shown that this
component plus a suitably chosen extragalactic CR component can give a
consistent description for the entire Galactic CR spectrum.


title: One-parameter families of functions in the Pick class

abstract:
  In the one-parameter family of power-law maps of the form
$f_a(x)=-|x|^{\alpha}+a,$ $\alpha >1,$ we give examples of mutually related
dynamically determined quantities, depending on the parameter $a$, such that
one is a Pick function of the following one. These Pick functions are
extendable by reflection through the $(1,+\infty)$ half-axis and have
completely monotone derivatives there.


title: The homology of the Steinberg variety and Weyl group coinvariants

abstract:
  Let G be a complex, connected, reductive algebraic group with Weyl group W
and Steinberg variety Z. We show that the graded Borel-Moore homology of Z is
isomorphic to the smash product of the coinvariant algebra of W and the group
algebra of W.


title: Spin-spin Correlation in Some Excited States of Transverse Ising Model

abstract:
  We consider the transverse Ising model in one dimension with
nearest-neighbour interaction and calculate exactly the longitudinal spin-spin
correlation for a class of excited states. These states are known to play an
important role in the perturbative treatment of one-dimensional transverse
Ising model with frustrated second-neighbour interaction. To calculate the
correlation, we follow the earlier procedure of Wu, use Szego's theorem and
also use Fisher-Hartwig conjecture. The result is that the correlation decays
algebraically with distance ($n$) as $1/\surd n$ and is oscillatory or
non-oscillatory depending on the magnitude of the transverse field.


title:
Radiative quarkonium decays and the NMSSM Higgs interpretation of the
  HyperCP Sigma+ --> p mu+mu- events

abstract:
  We study the potential of radiative decays of the Upsilon(1S) and of the phi
mesons to search for a light pseudoscalar Higgs boson, proposed as a possible
interpretation of Sigma+ --> p mu+mu- events observed by the HyperCP
collaboration at Fermilab. We conclude that the detection of this signal should
certainly be possible with the current CLEO Upsilon(1S) data, and is within the
reach of KLOE in at least part of the range of couplings suggested by the
HyperCP findings.


title:
A resummed perturbative estimate for the quarkonium spectral function in
  hot QCD

abstract:
  By making use of the finite-temperature real-time static potential that was
introduced and computed to leading non-trivial order in Hard Thermal Loop
resummed perturbation theory in recent work, and solving numerically a
Schr\"odinger-type equation, we estimate the quarkonium (in practice,
bottomonium) contribution to the spectral function of the electromagnetic
current in hot QCD. The spectral function shows a single resonance peak which
becomes wider and then disappears as the temperature is increased beyond 450
MeV or so. This behaviour can be compared with recently attempted lattice
reconstructions of the same quantity, based on the ``maximum entropy method'',
which generically show several peaks. We also specify the dependence of our
results on the spatial momentum of the electromagnetic current, as well as on
the baryon chemical potential characterising the hot QCD plasma.


title: An Exotic Approach to Hadron Physics

abstract:
  An exotic approach to hadrons is discussed. It is based on the recently
developed open-closed string duality explicitly conjectured as the AdS/CFT
correspondence. Mesons as well as pentaquarks are studied in this approach.
Spins are introduced as distribution functions over the string, and a second
quantization method of string theory is examined and used to estimate the mass
and decay width of various hadrons. This approach provides a way to understand
the structure of flavor by a configuration of probe branes.


title:
Fermi Surface Reconstruction without Breakdown of Kondo Screening at
  Quantum Critical Point

abstract:
  Motivated by recent Hall-effect experiment in YbRh$_2$Si$_2$, we study ground
state properties of a Kondo lattice model in a two-dimensional square lattice
using variational Monte Carlo method. We show that there are two types of phase
transition, antiferromagnetic transition and topological one (Fermi surface
reconstruction). In a wide region of parameters, these two transitions occur
simultaneously without the breakdown of Kondo screening, accompanied by a
discontinuous change of the Hall coefficient. This result is consistent with
the experiment and gives a novel theoretical picture for the quantum critical
point in heavy fermion systems.


title: A User-Friendly Code to Diagnose Chromospheric Plasmas

abstract:
  The physical interpretation of spectropolarimetric observations of lines of
neutral helium, such as those of the 10830 A multiplet, represents an excellent
opportunity for investigating the magnetism of plasma structures in the solar
chromosphere. Here we present a powerful forward modeling and inversion code
that permits either to calculate the emergent intensity and polarization for
any given magnetic field vector or to infer the dynamical and magnetic
properties from the observed Stokes profiles. This diagnostic tool is based on
the quantum theory of spectral line polarization, which self-consistently
accounts for the Hanle and Zeeman effects in the most general case of the
incomplete Paschen-Back effect regime. We also take into account radiative
transfer effects. An efficient numerical scheme based on global optimization
methods has been applied. Our Stokes inversion code permits a fast and reliable
determination of the global minimum.


title: Inhomogeneous color superconductivity and the cooling of compact stars

abstract:
  In this talk I discuss the inhomogeneous (LOFF) color superconductive phases
of Quantum Chromodynamics (QCD). In particular, I show the effect of a core of
LOFF phase on the cooling of a compact star.


title: Scaling anomaly in cosmic string background

abstract:
  We show that the classical scale symmetry of a particle moving in cosmic
string background is broken upon inequivalent quantization of the classical
system, leading to anomaly. The consequence of this anomaly is the formation of
single bound state in the coupling interval \gamma\in(-1,1). The inequivalent
quantization is characterized by a 1-parameter family of self-adjoint extension
parameter \omega. It has been conjectured that the formation of loosely bound
state in cosmic string background may lead to the so called anomalous
scattering cross section for the particles, which is usually seen in molecular
physics.


title:
On de Broglie's quantum particle as the soliton solution of linear
  Schr\"odinger equation

abstract:
  We develop a class of soliton solution of {\it linear} Schr\"odinger equation
without external potential. The quantum probability density generates its own
boundary inside which there is internal vibration whose wave number is
determined by the velocity of the particle as firstly conjectured by de
Broglie. Assuming resonance of the internal vibration will lead to quantization
of particle's momentum in term of wave number of the envelope quantum
probability density. We further show that the linearity of the Schr\"odinger
equation allows us to have non-interacting many solitons solution through
superposition, each describing a particle with equal mass.


title:
Stringy corrections to a time-dependent background solution of string
  and M-Theory

abstract:
  We consider one of the simplest time-dependent backgrounds in M-theory,
describing the shrinking away of the M-theory dimension with the other spatial
dimensions static. As the M-theory dimension becomes small, the situation
becomes well-described by string theory in a singular cosmological background
where the string coupling tends to zero but the $\alpha'$-corrections become
large, near the cosmic singularity. We compute these $\alpha'$-corrections,
both for the background and for linearized perturbations, in heterotic string
theory, and show they may be reproduced by a map from eleven-dimensional
M-theory.


title: Doubly Special Relativity and Finsler geometry

abstract:
  We discuss the recent proposal of implementing Doubly Special Relativity in
configuration space by means of Finsler geometry. Although this formalism leads
to a consistent description of the dynamics of a particle, it does not seem to
give a complete description of the physics. In particular, the Finsler line
element is not invariant under the deformed Lorentz transformations of Doubly
Special Relativity. We study in detail some simple applications of the
formalism.


title:
The Sedentary Survey of Extreme High Energy Peaked BL Lacs III. Results
  from Optical Spectroscopy

abstract:
  The multi-frequency Sedentary Survey is a flux limited, statistically
well-defined sample of highly X-ray dominated BL Lacertae objects (HBLs) which
includes 150 sources. In this paper, the third of the series, we report the
results of a dedicated optical spectroscopy campaign that, together with
results from other independent optical follow up programs, led to the
spectroscopic identification of all sources in the sample. We carried out a
systematic spectroscopic campaign for the observation of all unidentified
objects of the sample using the ESO 3.6m, the KPNO 4m, and the TNG optical
telescopes. We present new identifications and optical spectra for 76 sources,
50 of which are new BL Lac objects, 18 are sources previously referred as BL
Lacs but for which no redshift information was available, and 8 are broad
emission lines AGNs. We find that the multi-frequency selection technique used
to build the survey is highly efficient (about 90%) in selecting BL Lacs
objects. We present positional and spectroscopic information for all confirmed
BL Lac objects. Our data allowed us to determined 36 redshifts out of the 50
new BL Lacs and 5 new redshifts for the previously known objects. The redshift
distribution of the complete sample is presented and compared with that of
other BL Lacs samples. For 26 sources without recognizable absorption features,
we calculated lower limits to the redshift using a method based on simulated
optical spectra with different ratios between jet and galaxy emission. For a
subsample of 38 object with high-quality spectra, we find a correlation between
the optical spectral slope, the 1.4 GHz radio luminosity, and the Ca H&K break
value, indicating that for powerful/beamed sources the optical light is
dominated by the non-thermal emission from the jet.


title: Latin bitrades derived from groups

abstract:
  A latin bitrade is a pair of partial latin squares which are disjoint, occupy
the same set of non-empty cells, and whose corresponding rows and columns
contain the same set of entries. Dr\'apal (\cite{Dr9}) showed that a latin
bitrade is equivalent to three derangements whose product is the identity and
whose cycles pairwise have at most one point in common. By letting a group act
on itself by right translation, we show how some latin bitrades may be derived
from groups without specifying an independent group action. Properties of latin
trades such as homogeneousness, minimality (via thinness) and orthogonality may
also be encoded succinctly within the group structure. We apply the
construction to some well-known groups, constructing previously unknown latin
bitrades. In particular, we show the existence of minimal, $k$-homogeneous
latin trades for each odd $k\geq 3$. In some cases these are the smallest known
such examples.


title: Wormholes in the accelerating universe

abstract:
  We discuss different arguments that have been raised against the viability of
the big trip process, reaching the conclusions that this process can actually
occur by accretion of phantom energy onto the wormholes and that it is stable
and might occur in the global context of a multiverse model. We finally argue
that the big trip does not contradict any holographic bounds on entropy and
information.


title:
Spheroidal and torsional modes of quasistatic shear oscillations in the
  solid globe models of nuclear physics and pulsar astrophysics

abstract:
  The past three decades of investigation on nuclear physics and pulsar
astrophysics have seen gradual recognition that elastodynamic approach to the
continuum mechanics of nuclear matter provides proper account of macroscopic
motions of degenerate Fermi-matter constituting interior of the nuclear
material objects, the densest of all known today. This paper focuses on one
theoretical issue of this development which is concerned with oscillatory
behavior of a viscoelastic solid globe in the regime of quasistatic,
force-free, non-compressional oscillations less investigated in the literature
compared to oscillations in the regime of standing shear waves. We show that in
this case the problem of computing frequency and lifetime of spheroidal and
torsional modes of non-radial shear vibrations damped by viscosity can be
unambiguously resolved by working from the energy balance equation and taking
advantage of the Rayleigh's variational method. The efficiency of this method
is demonstrated by solid globe models of nuclear physics and pulsar
astrophysics dealing with oscillations of a spherical mass of a viscoelastic
Fermi-solid with homogeneous and non-homogeneous profiles of the bulk density,
the shear modulus, and the shear viscosity.


title: Extra force in $f(R)$ modified theories of gravity

abstract:
  The equation of motion for test particles in $f(R)$ modified theories of
gravity is derived. By considering an explicit coupling between an arbitrary
function of the scalar curvature, $R$, and the Lagrangian density of matter, it
is shown that an extra force arises. This extra force is orthogonal to the
four-velocity and the corresponding acceleration law is obtained in the weak
field limit. Connections with MOND and with the Pioneer anomaly are further
discussed.


title: Averaging and Cosmological Observations

abstract:
  The gravitational field equations on cosmological scales are obtained by
averaging the Einstein field equations of general relativity. By assuming
spatial homogeneity and isotropy on the largest scales, the local
inhomogeneities affect the dynamics though correction (backreaction) terms,
which can lead to behaviour qualitatively and quantitatively different from the
Friedmann-Lema\^{i}tre-Robertson-Walker models. The effects of averaging on
cosmological observations are discussed. It is argued that, based on estimates
from observational data, the backreaction (and, in particular, the averaged
spatial curvature) can have a very significant dynamical effect on the
evolution of the Universe and must be taken into account in observational
cosmology.


title: Calorimetry of Bose-Einstein condensates

abstract:
  We outline a practical scheme for measuring the thermodynamic properties of a
Bose-Einstein condensate as a function of internal energy. We propose using
Bragg scattering and controlled trap manipulations to impart a precise amount
of energy to a near zero temperature condensate. After thermalisation the
temperature can be measured using standard techniques to determine the state
equation $T(U,N,\omega)$. Our analysis accounts for interaction effects and the
excitation of constants of motion which restrict the energy available for
thermalisation.


title: Parallelizing Quantum Circuits

abstract:
  We present a novel automated technique for parallelizing quantum circuits via
forward and backward translation to measurement-based quantum computing
patterns and analyze the trade off in terms of depth and space complexity. As a
result we distinguish a class of polynomial depth circuits that can be
parallelized to logarithmic depth while adding only polynomial many auxiliary
qubits. In particular, we provide for the first time a full characterization of
patterns with flow of arbitrary depth, based on the notion of influencing paths
and a simple rewriting system on the angles of the measurement. Our method
leads to insightful knowledge for constructing parallel circuits and as
applications, we demonstrate several constant and logarithmic depth circuits.
Furthermore, we prove a logarithmic separation in terms of quantum depth
between the quantum circuit model and the measurement-based model.


title: Quantum memory for images - a quantum hologram

abstract:
  Matter-light quantum interface and quantum memory for light are important
ingredients of quantum information protocols, such as quantum networks,
distributed quantum computation, etc. In this Letter we present a spatially
multimode scheme for quantum memory for light, which we call a quantum
hologram. Our approach uses a multi-atom ensemble which has been shown to be
efficient for a single spatial mode quantum memory. Due to the multi-atom
nature of the ensemble it is capable of storing many spatial modes, a feature
critical for the present proposal. A quantum hologram has a higher storage
capacity compared to a classical hologram, and is capable of storing quantum
features of an image, such as multimode superposition and entangled quantum
states, something that a standard hologram is unable to achieve. Due to optical
parallelism, the information capacity of the quantum hologram will obviously
exceed that of a single-mode scheme.


title: Financial time-series analysis: A brief overview

abstract:
  Prices of commodities or assets produce what is called time-series. Different
kinds of financial time-series have been recorded and studied for decades.
Nowadays, all transactions on a financial market are recorded, leading to a
huge amount of data available, either for free in the Internet or commercially.
Financial time-series analysis is of great interest to practitioners as well as
to theoreticians, for making inferences and predictions. Furthermore, the
stochastic uncertainties inherent in financial time-series and the theory
needed to deal with them make the subject especially interesting not only to
economists, but also to statisticians and physicists. While it would be a
formidable task to make an exhaustive review on the topic, with this review we
try to give a flavor of some of its aspects.


title:
Integral representations for solutions of exponential Gauss-Manin
  systems

abstract:
  Let f,g be two algebraically independent regular functions from the smooth
affine complex variety U to the affine line. The associated exponential
Gauss-Manin systems on the affine line are defined to be the cohomology sheaves
of the direct image of the exponential differential system $\mathcal{O}_U e^g $
with respect to f. We prove that its holomorphic solutions admit
representations in terms of period integrals over topological chains with
possibly closed support and with rapid decay condition.


title: Charged current deep-inelastic scattering at three loops

abstract:
  We derive for deep-inelastic neutrino-proton scattering in the combination nu
P - nubar P the perturbative QCD corrections to three loops for the charged
current structure functions F_2, F_L and F_3. In leading twist approximation we
calculate the first five odd-integer Mellin moments in the case of F_2 and F_L
and the first five even-integer moments in the case of F_3. As a new result we
obtain the coefficient functions to O(alpha_s^3) while the corresponding
anomalous dimensions agree with known results in the literature.


title:
Detection of a 1258 Hz high-amplitude kilohertz quasi-periodic
  oscillation in the ultra-compact X-ray binary 1A 1246-588

abstract:
  We have observed the ultra-compact low-mass X-ray binary (LMXB) 1A 1246-588
with the Rossi X-ray Timing Explorer (RXTE). In this manuscript we report the
discovery of a kilohertz quasi-periodic oscillation (QPO) in 1A 1246-588. The
kilohertz QPO was only detected when the source was in a soft high-flux state
reminiscent of the lower banana branch in atoll sources. Only one kilohertz QPO
peak is detected at a relatively high frequency of 1258+-2 Hz and at a single
trial significance of more than 7 sigma. Kilohertz QPOs with a higher frequency
have only been found on two occasions in 4U 0614+09. Furthermore, the frequency
is higher than that found for the lower kilohertz QPO in any source, strongly
suggesting that the QPO is the upper of the kilohertz QPO pair often found in
LMXBs. The full-width at half maximum is 25+-4 Hz, making the coherence the
highest found for an upper kilohertz QPO. From a distance estimate of ~6 kpc
from a radius expansion burst we derive that 1A 1246-588 is at a persistent
flux of ~0.2-0.3 per cent of the Eddington flux, hence 1A 1246-588 is one of
the weakest LMXBs for which a kilohertz QPO has been detected. The
root-mean-square (rms) amplitude in the 5-60 keV band is 27+-3 per cent, this
is the highest for any kilohertz QPO source so far, in line with the general
anti-correlation between source luminosity and rms amplitude of the kilohertz
QPO peak identified before. Using the X-ray spectral information we produce a
colour-colour diagram. The source behaviour in this diagram provides further
evidence for the atoll nature of the source.


title: Surface gap solitons at a nonlinearity interface

abstract:
  We demonstrate existence of waves localized at the interface of two nonlinear
periodic media with different coefficients of the cubic nonlinearity via the
one-dimensional Gross--Pitaevsky equation. We call these waves the surface gap
solitons (SGS). In the case of smooth symmetric periodic potentials, we study
analytically bifurcations of SGS's from standard gap solitons and determine
numerically the maximal jump of the nonlinearity coefficient allowing for the
SGS existence. We show that the maximal jump vanishes near the thresholds of
bifurcations of gap solitons. In the case of continuous potentials with a jump
in the first derivative at the interface, we develop a homotopy method of
continuation of SGS families from the solution obtained via gluing of parts of
the standard gap solitons and study existence of SGS's in the photonic band
gaps. We explain the termination of the SGS families in the interior points of
the band gaps from the bifurcation of linear bound states in the continuous
non-smooth potentials.


title:
A Catalogue of Morphologically Classified Galaxies from the Sloan
  Digital Sky Survey: North Equatorial Region

abstract:
  We present a catalogue of morphologically classified bright galaxies in the
north equatorial stripe (230 deg$^2$) derived from the Third Data Release of
the Sloan Digital Sky Survey (SDSS). Morphological classification is performed
by visual inspection of images in the $g$ band. The catalogue contains 2253
galaxies complete to a magnitude limit of $r=16$ after Galactic extinction
correction, selected from 2658 objects that are judged as extended in the
photometric catalogue in the same magnitude limit. 1866 galaxies in our
catalogue have spectroscopic information. A brief statistical analysis is
presented for the frequency of morphological types and mean colours in the
catalogue. A visual inspection of the images reveals that the rate of
interacting galaxies in the local Universe is approximately 1.5% in the
$r\le16$ sample. A verification is made for the photometric catalogue generated
by the SDSS, especially as to its bright end completeness.


title: Blazar surveys with WMAP and Swift

abstract:
  We present the preliminary results from two new surveys of blazars that have
direct implications on the GLAST detection of extragalactic sources from two
different perspectives: microwave selection and a combined deep X-ray/radio
selection. The first one is a 41 GHz flux-limited sample extracted from the
WMAP 3-yr catalog of microwave point sources. This is a statistically well
defined sample of about 200 blazars and radio galaxies, most of which are
expected to be detected by GLAST. The second one is a new deep survey of
Blazars selected among the radio sources that are spatially coincident with
serendipitous sources detected in deep X-ray images (0.3-10 keV) centered on
the Gamma Ray Bursts (GRB) discovered by the Swift satellite. This sample is
particularly interesting from a statistical viewpoint since a) it is unbiased
as GRBs explode at random positions in the sky, b) it is very deep in the X-ray
band (\fx \simgt $10^{-15}$ \ergs) with a position accuracy of a few
arc-seconds, c) it will cover a fairly large (20-30 square deg.) area of sky,
d) it includes all blazars with radio flux (1.4 GHz) larger than 10 mJy, making
it approximately two orders of magnitude deeper than the WMAP sample and about
one order of magnitude deeper than the deepest existing complete samples of
radio selected blazars, and e) it can be used to estimate the amount of
unresolved GLAST high latitude gamma-ray background and its anisotropy
spectrum.


title: I. The mass gap and solution of the quark confinement problem in QCD

abstract:
  Using the previously derived confining gluon propagator, the corresponding
system of equations determining the quark propagator is derived. The system of
equations consists of the Schwinger-Dyson equation for the quark propagator
itself, which includes the zero momentum transfer quark-gluon vertex. It is
complemented by the Slavnov-Taylor identity for this vertex. The quark equation
depends explicitly on the mass gap, determining the scale of the truly
nonperturbative dynamics in the QCD ground state. The obtained system of
equations is manifestly gauge-invariant, i.e., does not depend explicitly on
the gauge-fixing parameter. It is also free from all the types of the
perturbative contributions ("contaminations"), which may appear at the
fundamental quark-gluon level.


title: Tunnelling from black holes and tunnelling into white holes

abstract:
  Hawking radiation is nowadays being understood as tunnelling through black
hole horizons. Here, the extension of the Hamilton-Jacobi approach to
tunnelling for non-rotating and rotating black holes in different non-singular
coordinate systems not only confirms this quantum emission from black holes but
also reveals the new phenomenon of absorption into white holes by quantum
mechanical tunnelling. The role of a boundary condition of total absorption or
emission is also clarified.


title: Solving algebraic equations in roots of unity

abstract:
  This paper is devoted to finding solutions of polynomial equations in roots
of unity. It was conjectured by S. Lang and proved by M. Laurent that all such
solutions can be described in terms of a finite number of parametric families
called maximal torsion cosets. We obtain new explicit upper bounds for the
number of maximal torsion cosets on an algebraic subvariety of the complex
algebraic $n$-torus ${\mathbb G}_{\rm m}^n$. In contrast to earlier works that
give the bounds of polynomial growth in the maximum total degree of defining
polynomials, the proofs of our results are constructive. This allows us to
obtain a new algorithm for determining maximal torsion cosets on an algebraic
subvariety of ${\mathbb G}_{\rm m}^n$.


title: Self-Organization applied to Dynamic Network Layout

abstract:
  As networks and their structure have become a major field of research, a
strong demand for network visualization has emerged. We address this challenge
by formalizing the well established spring layout in terms of dynamic
equations. We thus open up the design space for new algorithms. Drawing from
the knowledge of systems design, we derive a layout algorithm that remedies
several drawbacks of the original spring layout. This new algorithm relies on
the balancing of two antagonistic forces. We thus call it {\em arf} for
"attractive and repulsive forces". It is, as we claim, particularly suited for
a dynamic layout of smaller networks ($n < 10^3$). We back this claim with
several application examples from on going complex systems research.


title: VIMOS total transmission profiles for broad-band filters

abstract:
  VIMOS is a wide-field imager and spectrograph mounted on UT3 at the
  VLT, whose FOV consists of four 7'x8' quadrants. Here we present the
measurements of total transmission profiles -- i.e. the throughput of telescope
+ instrument -- for the broad band filters U, B, V, R, I, and z for each of its
four quadrants. Those measurements can also be downloaded from the public VIMOS
web-page. The transmission profiles are compared with previous estimates from
the VIMOS consortium.


title: Searches for Ultra-Compact Dwarf Galaxies in Galaxy Groups

abstract:
  We present the results of a search for ultra-compact dwarf galaxies (UCDs) in
six different galaxy groups: Dorado, NGC1400, NGC0681, NGC4038, NGC4697 and
NGC5084. We searched in the apparent magnitude range 17.5 < b_j < 20.5 (except
NGC5084: 19.2 < b_j < 21.0). We found 1 definite plus 2 possible UCD candidates
in the Dorado group and 2 possible UCD candidates in the NGC1400 group. No UCDs
were found in the other groups. We compared these results with predicted
luminosities of UCDs in the groups according to the hypothesis that UCDs are
globular clusters formed in galaxies. The theoretical predictions broadly agree
with the observational results, but deeper surveys are needed to fully test the
predictions.


title: Information Theoretic Proofs of Entropy Power Inequalities

abstract:
  While most useful information theoretic inequalities can be deduced from the
basic properties of entropy or mutual information, up to now Shannon's entropy
power inequality (EPI) is an exception: Existing information theoretic proofs
of the EPI hinge on representations of differential entropy using either Fisher
information or minimum mean-square error (MMSE), which are derived from de
Bruijn's identity. In this paper, we first present an unified view of these
proofs, showing that they share two essential ingredients: 1) a data processing
argument applied to a covariance-preserving linear transformation; 2) an
integration over a path of a continuous Gaussian perturbation. Using these
ingredients, we develop a new and brief proof of the EPI through a mutual
information inequality, which replaces Stam and Blachman's Fisher information
inequality (FII) and an inequality for MMSE by Guo, Shamai and Verd\'u used in
earlier proofs. The result has the advantage of being very simple in that it
relies only on the basic properties of mutual information. These ideas are then
generalized to various extended versions of the EPI: Zamir and Feder's
generalized EPI for linear transformations of the random variables, Takano and
Johnson's EPI for dependent variables, Liu and Viswanath's
covariance-constrained EPI, and Costa's concavity inequality for the entropy
power.


title:
Van der Waals interaction between a microparticle and a single-wall
  carbon nanotube

abstract:
  The Lifshitz-type formulas describing the free energy and the force of the
van der Waals interaction between an atom (molecule) and a single-wall carbon
nanotube are obtained. The single-wall nanotube is considered as a cylindrical
sheet carrying a two-dimensional free electron gas with appropriate boundary
conditions on the electromagnetic field. The obtained formulas are used to
calculate the van der Waals free energy and force between a hydrogen atom
(molecule) and single-wall carbon nanotubes of different radia. Comparison
studies of the van der Waals interaction of hydrogen atoms with single- and
multi-wall carbon nanotubes show that depending on atom-nanotube separation
distance the idealization of graphite dielectric permittivity is already
applicable to nanotubes with only two or three walls.


title: Relativistic corrections for two- and three-body flux tube model

abstract:
  We generalize the relativistic flux tube model for arbitrary two- or
three-body systems. The spin-independent and spin-dependent contributions of
the flux tube to the total Hamiltonian are computed in perturbation. In
particular, we show that the spin-dependent part exhibits a universal
spin-orbit form: It does not depend on the nature of the confined particles.
The general equations we present, being well-defined for light particles, can
thus be applied to usual as well as exotic hadrons such as hybrid mesons and
glueballs.


title: The No-Broadcasting Theorem and its Classical Counterpart

abstract:
  Although it is widely accepted that `no-broadcasting' -- the nonclonability
of quantum information -- is a fundamental principle of quantum mechanics, an
impossibility theorem for the broadcasting of general density matrices has not
yet been formulated. In this paper, we present a general proof for the
no-broadcasting theorem, which applies to arbitrary density matrices. The proof
relies on entropic considerations, and as such can also be directly linked to
its classical counterpart, which applies to probabilistic distributions of
statistical ensembles.


title: Quantum random walks and vanishing of the second Hochschild cohomology

abstract:
  Given a conditionally completely positive map $\mathcal L$ on a unital
$\ast$-algebra $\A$, we find an interesting connection between the second
Hochschild cohomology of $\A$ with coefficients in the bimodule $E_{\mathcal
L}=\B^a(\A \oplus M)$ of adjointable maps, where $M$ is the GNS bimodule of
$\mathcal L$, and the possibility of constructing a quantum random walk (in the
sense of \cite{AP,LP,L,KBS}) corresponding to $\mathcal L$.


title: The Invar Tensor Package

abstract:
  The Invar package is introduced, a fast manipulator of generic scalar
polynomial expressions formed from the Riemann tensor of a four-dimensional
metric-compatible connection. The package can maximally simplify any polynomial
containing tensor products of up to seven Riemann tensors within seconds. It
has been implemented both in Mathematica and Maple algebraic systems.


title:
Towards a Gauge Invariant Scattering Theory of Cylindrical Gravitational
  Waves

abstract:
  In this account we investigate an asymptotically flat space-time geometry. In
particular, we focus on a pure gravity model with cylindrical symmetry where no
matter fields are included. The Einstein-Rosen metric is introduced and the
corresponding Einstein equations are solved. By use of the ADM formalism, we
derive the observables of the cylindrical gravitational waves. We conclude with
an analysis of the algebra of the observables of the Einstein-Rosen waves.


title:
On axisymmetric MHD equilibria with incompressible flows under side
  conditions

abstract:
  Axisymmetric equilibria with incompressible flows of arbitrary direction are
studied in the framework of magnetohydrodynamics under a variety of physically
relevant side conditions. To this end a set of pertinent non-linear ODEs are
transformed to quasilinear ones and the respective initial value problem is
solved numerically with appropriately determined initial values near the
magnetic axis. Several equilibria are then constructed surface by surface. The
non field aligned flow results in novel configurations with a single magnetic
axis, toroidal shell configurations in which the plasma is confined within a
couple of magnetic surfaces and double shell-like configurations. In addition,
the flow affects the elongation and triangularity of the magnetic surfaces.


title:
Vertex-algebraic structure of the principal subspaces of certain
  A_1^(1)-modules, I: level one case

abstract:
  This is the first in a series of papers in which we study vertex-algebraic
structure of Feigin-Stoyanovsky's principal subspaces associated to standard
modules for both untwisted and twisted affine Lie algebras. A key idea is to
prove suitable presentations of principal subspaces, without using bases or
even ``small'' spanning sets of these spaces. In this paper we prove
presentations of the principal subspaces of the basic A_1^(1)-modules. These
convenient presentations were previously used in work of
Capparelli-Lepowsky-Milas for the purpose of obtaining the classical
Rogers-Ramanujan recursion for the graded dimensions of the principal
subspaces.


title: Galaxy Evolution and Environment

abstract:
  The properties of galaxies are strongly correlated with their environment,
with red galaxies dominating galaxy clusters and blue galaxies dominating the
general field. However, not all field galaxies are young: studies of the
colors, line strengths, and M/L ratios of massive early-type galaxies at
0<z<1.3 show that the most massive galaxies do not seem to care about their
surroundings, and have very similar ages irrespective of their environment.
There is good evidence that the growth of these galaxies does continue longer
in the field than in clusters, via (nearly) dissipationless mergers of already
old galaxies. These results are consistent with predictions of recent galaxy
formation models, which incorporate AGN feedback to suppress star formation in
the most massive halos. Systematic studies of the relation of galaxies with
their environment beyond z=1 are difficult, and still somewhat contradictory.
Intriguingly both the DEEP2 and VVDS surveys find that the color-density
relation disappears at z~1.3, unfortunately just at the point where both
surveys become highly incomplete. On the other hand, clustering studies at
z~2.5 have shown that red galaxies cluster more strongly than blue galaxies,
implying that the color-density relation was already in place at that redshift.


title: GLSM's for partial flag manifolds

abstract:
  In this paper we outline some aspects of nonabelian gauged linear sigma
models. First, we review how partial flag manifolds (generalizing
Grassmannians) are described physically by nonabelian gauged linear sigma
models, paying attention to realizations of tangent bundles and other aspects
pertinent to (0,2) models. Second, we review constructions of Calabi-Yau
complete intersections within such flag manifolds, and properties of the gauged
linear sigma models. We discuss a number of examples of nonabelian GLSM's in
which the Kahler phases are not birational, and in which at least one phase is
realized in some fashion other than as a complete intersection, extending
previous work of Hori-Tong. We also review an example of an abelian GLSM
exhibiting the same phenomenon. We tentatively identify the mathematical
relationship between such non-birational phases, as examples of Kuznetsov's
homological projective duality. Finally, we discuss linear sigma model moduli
spaces in these gauged linear sigma models. We argue that the moduli spaces
being realized physically by these GLSM's are precisely Quot and hyperquot
schemes, as one would expect mathematically.


title: Warm HCN, C2H2, and CO in the disk of GV Tau

abstract:
  We present the first high-resolution, ground-based observations of HCN and
C2H2 toward the T Tauri binary star system GV Tau. We detected strong
absorption due to HCN nu_3 and weak C2H2 (nu_3 and nu_2 + (nu_4 + nu_5)^0_+)
absorption toward the primary (GV Tau S) but not the infrared companion. We
also report CO column densities and rotational temperatures, and present
abundances relative to CO of HCN/CO ~0.6% and C2H2/CO ~1.2% and an upper limit
for CH4/CO < 0.37% toward GV Tau S. Neither HCN nor C2H2 were detected toward
the infrared companion and results suggest that abundances may differ between
the two sources.


title: Towards understanding of birds magnetoreceptor mechanism

abstract:
  In the present letter we suggest a new theoretical model for a quantitative
description of the magnetoreception mechanism in birds. The considered
mechanism involves two types of iron minerals (magnetite and maghemite) which
were found in subcellular compartments within sensory dendrites of the upper
beak of several bird species. The analysis of forces acting between the iron
particles shows that the orientation of the external geomagnetic field can
significantly change the probability of the mechanosensitive ion channels
opening and closing. The performed theoretical analysis shows that the
suggested magnetoreceptor system might be a sensitive biological magnetometer
providing an essential part of the magnetic map for navigation.


title: Another Riemann-Farey Computation

abstract:
  Another approach to constructing an upper bound for the Riemann-Farey sum is
described.


title:
Spitzer Mid-Infrared Spectroscopy of Infrared Luminous Galaxies at z~2
  II: Diagnostics

abstract:
  We present mid-IR spectral decomposition of a sample of 48 Spitzer-selected
ULIRGs spanning z~1-3 and likely L_IR~10^12-10^13Lsun. Our study aims at
quantifying the star-formation and AGN processes in these sources which recent
results suggest have evolved strongly between the observed epoch and today. To
do this, we study the mid-IR contribution of PAH emission, continuum, and
extinction. About 3/4 of our sample are continuum- (i.e. AGN) dominated
sources, but ~60% of these show PAH emission, suggesting the presence of
star-formation activity. These sources have redder mid-IR colors than typical
optically-selected quasars. About 25% of our sample have strong PAH emission,
but none are likely to be pure starbursts as reflected in their relatively high
5um hot dust continua. However, their steep 30um-to-14um slopes suggest that
star-formation might dominate the total infrared luminosity. Six of our z~2
sources have EW6.2>~0.3um and L_14um>~10^12Lsun (implying L_IR>~10^13Lsun). At
these luminosities, such high EW6.2 ULIRGs do not exist in the local Universe.
We find a median optical depth at 9.7um of <tau_9.7>=1.4. This is consistent
with local IRAS-selected ULIRGs, but differs from early results on
SCUBA-selected z~2 ULIRGs. Similar to local ULIRGs about 25% of our sample show
extreme obscuration (tau_9.7>~3) suggesting buried nuclei. In general, we find
that our sources are similar to local ULIRGs, but are an order of magnitude
more luminous. It is not clear whether our z~2 ULIRGs are simply scaled-up
versions of local ULIRGs, or subject to fundamentally different physical
processes.


title: Jeans instability of a galactic disk embedded in a live dark halo

abstract:
  We investigate the Jeans instability of a galactic disk embedded in a
dynamically responsive dark halo. It is shown that the disk-halo system becomes
nominally Jeans unstable. On small scales the instability is suppressed, if the
Toomre stability index Q_T is higher than a certain threshold, but on large
scales the Jeans instability sets invariably in. However, using a simple
self-consistent disk-halo model it is demonstrated that this occurs on scales
which are much larger than the system so that this is indeed only a nominal
effect. From a practical point of view the Jeans instability of galactic disks
is not affected by a live dark halo.


title:
The multiplicity of planet host stars - New low-mass companions to
  planet host stars

abstract:
  We present new results from our ongoing multiplicity study of exoplanet host
stars, carried out with the infrared camera SofI at ESO-NTT. We have identified
new low mass companions to the planet host stars HD101930 and HD65216.
HD101930AB is a wide binary systems composed of the planet host star HD101930A
and its companion HD101930B which is a M0 to M1 dwarf with a mass of about
0.7Msun separated from the primary by ~73arcsec (2200AU projected separation).
HD65216 forms a hierarchical triple system, with a projected separation of
253AU (angular separation of about 7arcsec) between the planet host star
HD65216A and its close binary companion HD65216BC, whose two components are
separated by only ~0.17arcsec (6AU of projected separation). Two VLT-NACO
images separated by 3 years confirm that this system is co-moving to the planet
host star. The infrared photometry of HD65216B and C is consistent with a M7 to
M8 (0.089Msun), and a L2 to L3 dwarf (0.078Msun), respectively, both close to
the sub-stellar limit. An infrared spectrum with VLT-ISAAC of the pair
HD65216BC, even though not resolved spatially, confirms this late spectral
type. Furthermore, we present H- and K-band ISAAC infrared spectra of HD16141B,
the recently detected co-moving companion of the planet host star HD16141A. The
infrared spectroscopy as well as the apparent infrared photometry of HD16141B
are both fully consistent with a M2 to M3 dwarf located at the distance of the
planet host star.


title:
Assessment and Propagation of Input Uncertainty in Tree-based Option
  Pricing Models

abstract:
  This paper aims to provide a practical example on the assessment and
propagation of input uncertainty for option pricing when using tree-based
methods. Input uncertainty is propagated into output uncertainty, reflecting
that option prices are as unknown as the inputs they are based on. Option
pricing formulas are tools whose validity is conditional not only on how close
the model represents reality, but also on the quality of the inputs they use,
and those inputs are usually not observable. We provide three alternative
frameworks to calibrate option pricing tree models, propagating parameter
uncertainty into the resulting option prices. We finally compare our methods
with classical calibration-based results assuming that there is no options
market established. These methods can be applied to pricing of instruments for
which there is not an options market, as well as a methodological tool to
account for parameter and model uncertainty in theoretical option pricing.


title:
Subdiffusion and weak ergodicity breaking in the presence of a reactive
  boundary

abstract:
  We derive the boundary condition for a subdiffusive particle interacting with
a reactive boundary with finite reaction rate. Molecular crowding conditions,
that are found to cause subdiffusion of larger molecules in biological cells,
are shown to effect long-tailed distributions with identical exponent for both
the unbinding times from the boundary to the bulk and the rebinding times from
the bulk. This causes a weak ergodicity breaking: typically, an individual
particle either stays bound or remains in the bulk for very long times. We
discuss why this may be beneficial for in vivo gene regulation by DNA-binding
proteins, whose typical concentrations are nanomolar


title:
Satellites of Simulated Galaxies: survival, merging, and their relation
  to the dark and stellar halos

abstract:
  We study the population of satellite galaxies formed in a suite of
N-body/gasdynamical simulations of galaxy formation in a LCDM universe. We find
little spatial or kinematic bias between the dark matter and the satellite
population. The velocity dispersion of the satellites is a good indicator of
the virial velocity of the halo: \sigma_{sat}/V_{vir}=0.9 +/- 0.2. Applied to
the Milky Way and M31 this gives V_{vir}^{MW}=109 +/- 22$ km/s and
V_{vir}^{M31} = 138 +/- 35 km/s, respectively, substantially lower than the
rotation speed of their disk components. The detailed kinematics of simulated
satellites and dark matter are also in good agreement. By contrast, the stellar
halo of the simulated galaxies is kinematically and spatially distinct from the
population of surviving satellites. This is because the survival of a satellite
depends on mass and on time of accretion; surviving satellites are biased
toward low-mass systems that have been recently accreted by the galaxy. Our
results support recent proposals for the origin of the systematic differences
between stars in the Galactic halo and in Galactic satellites: the elusive
``building blocks'' of the Milky Way stellar halo were on average more massive,
and were accreted (and disrupted) earlier than the population of dwarfs that
has survived self-bound until the present.


title: Fractional Generalization of Kac Integral

abstract:
  Generalization of the Kac integral and Kac method for paths measure based on
the Levy distribution has been used to derive fractional diffusion equation.
Application to nonlinear fractional Ginzburg-Landau equation is discussed.

categories: math-ph cond-mat.other math.MP nlin.CD physics.class-ph


title:
Analysis of the Velocity Field of F and G Dwarfs in the Solar
  Neighborhood as a Function of Age

abstract:
  The space velocities from the catalog of Nordstrom et al. (2004) are used to
trace variations of a number of kinematic parameters of single F and G dwarfs
as a function of their age. The vertex deviation of disk stars increases from
7+- 1 to 15+-2 degrees as the mean age decreases from 4.3 to 1.5 Gyr. The
two-dimensional velocity distributions in the UV, UW, and VW planes are
analyzed. The evolution of the main peaks in the velocity distributions can be
followed to an average age of approximately 9 Gyr. We find that: (1) in the
distributions of the UV velocity components, stars of different types are
concentrated toward several stable peaks (the Hyades, Pleiades, and Sirius
Cluster), suggesting that the stars belonging to these formations did not form
simultaneously; (2) the peak associated with the Hyades Cluster dominates in
all age intervals; and (3) the Hyades peak is strongest for stars with an
average age of 1.5 Gyr, suggesting that this peak contains a considerable
fraction of stars from the Hyades cluster. The age dependences of the kinematic
parameters exhibit a break near 4.5 Gyr, which can be explained as an effect of
the different contributions of stars of the thin and thick disks. The Stromberg
relation yields a solar LSR velocity of V_{\odot LSR} = (8.7, 6.2, 7.2)+- (0.5,
2.2, 0.8) km/s.


title:
Cosmic M\'enage \`a Trois: The Origin of Satellite Galaxies On Extreme
  Orbits

abstract:
  We examine the orbits of satellite galaxies identified in a suite of
N-body/gasdynamical simulations of the formation of $L_*$ galaxies in a LCDM
universe. Most satellites follow conventional orbits; after turning around,
they accrete into their host halo and settle on orbits whose apocentric radii
are steadily eroded by dynamical friction. However, a number of outliers are
also present, we find that ~1/3 of satellites identified at $z=0$ are on
unorthodox orbits, with apocenters that exceed their turnaround radii. This
population of satellites on extreme orbits consists typically of the faint
member of a satellite pair that has been ejected onto a highly-energetic orbit
during its first approach to the primary. Since the concurrent accretion of
multiple satellite systems is a defining feature of hierarchical models of
galaxy formation, we speculate that this three-body ejection mechanism may be
the origin of (i) some of the newly discovered high-speed satellites around M31
(such as Andromeda XIV); (ii) some of the distant fast-receding Local Group
members, such as Leo I; and (iii) the oddly isolated dwarf spheroidals Cetus
and Tucana in the outskirts of the Local Group. Our results suggest that care
must be exercised when using the orbits of the most weakly bound satellites to
place constraints on the total mass of the Local Group.


title:
Auxiliary Field Diffusion Monte Carlo calculation of nuclei with A<40
  with tensor interactions

abstract:
  We calculate the ground-state energy of 4He, 8He, 16O, and 40Ca using the
auxiliary field diffusion Monte Carlo method in the fixed phase approximation
and the Argonne v6' interaction which includes a tensor force. Comparison of
our light nuclei results to those of Green's function Monte Carlo calculations
shows the accuracy of our method for both open and closed shell nuclei. We also
apply it to 16O and 40Ca to show that quantum Monte Carlo methods are now
applicable to larger nuclei.


title:
Origin of Discrepancies in Inelastic Electron Tunneling Spectra of
  Molecular Junctions

abstract:
  We report inelastic electron tunneling spectroscopy (IETS) of multilayer
molecular junctions with and without incorporated metal nano-particles. The
incorporation of metal nanoparticles into our devices leads to enhanced IET
intensity and a modified line-shape for some vibrational modes. The enhancement
and line-shape modification are both the result of a low lying hybrid metal
nanoparticle-molecule electronic level. These observations explain the apparent
discrepancy between earlier IETS measurements of alkane thiolate junctions by
Kushmerick \emph{et al.} [Nano Lett. \textbf{4}, 639 (2004)] and Wang \emph{et
al.} [Nano Lett. \textbf{4}, 643 (2004)].


title:
Photoproduction of pi0-mesons off protons from the Delta(1232) region to
  E(gamma) = 3 GeV

abstract:
  Photoproduction of pi0 mesons was studied with the Crystal-Barrel detector at
ELSA for incident energies from 300 MeV to 3 GeV. Differential cross sections d
sigma /d Omega, d sigma/d t, and the total cross section are presented. For
E(gamma) < 3 GeV, the angular distributions agree well with the SAID
parametrization. At photon energies above 1.5 GeV, a strong forward peaking
indicates t-channel exchange to be the dominant process. The rapid variations
of the cross section with energy and angle indicate production of resonances.
An interpretation of the data within the Bonn-Gatchina partial wave analysis is
briefly discussed.


title: Magnetic and axial-vector transitions of the baryon antidecuplet

abstract:
  We report the recent results of the magnetic transitions and axial-vector
transitions of the baryon antidecuplet within the framework of the chiral
quark-soliton model. The dynamical model parameters are fixed by experimental
data for the magnetic moments of the baryon octet, for the hyperon semileptonic
decay constants, and for the singlet axial-vector constant. The transition
magnetic moments $\mu_{\Lambda\Sigma}$ and $\mu_{N\Delta}$ are well reproduced
and other octet-decuplet and octet-antidecuplet transitions are predicted. In
particular, the present calculation of $\mu_{\Sigma\Sigma^*}$ is found to be
below the upper bound $0.82\mu_N$ that the SELEX collaboration measured very
recently. The results explains consistently the recent findings of a new $N^*$
resonance from the GRAAL and Tohoku LNS group. We also obtain the transition
axial-vector constants for the $\Theta^+\to KN$ from which the decay width of
the $\Theta^{+}$ pentaquark baryon is determined as a function of the
pion-nucleon sigma term $\Sigma_{\pi N}$. We investigate the dependence of the
decay width of the $\Theta^{+}$ on the $g_{A}^{(0)}$, with the $g_{A}^{(0)}$
varied within the range of the experimental uncertainty. We show that a small
decay width of the $\Theta^{+}\to KN$, i.e. $\Gamma_{\Theta KN} \leq 1$ MeV, is
compatible with the values of all known semileptonic decays with the generally
accepted value of $g_{A}^{(0)} \approx 0.3$ for the proton.


title:
Quenched limits for transient, zero speed one-dimensional random walk in
  random environment

abstract:
  We consider a nearest-neighbor, one dimensional random walk
$\{X_n\}_{n\geq0}$ in a random i.i.d. environment, in the regime where the walk
is transient but with zero speed, so that $X_n$ is of order $n^s$ for some
$s<1$. Under the quenched law (i.e., conditioned on the environment), we show
that no limit laws are possible: There exist sequences $\{n_k\}$ and $\{x_k\}$
depending on the environment only, such that $X_{n_k}-x_k=o(\log n_k)^2$ (a
localized regime). On the other hand, there exist sequences $\{t_m\}$ and
$\{s_m\}$ depending on the environment only, such that $\log s_m/\log t_m\to
s<1$ and $P_{\omega}(X_{t_m}/s_m\leq x)\to1/2$ for all $x>0$ and $\to0$ for
$x\leq0$ (a spread out regime).


title: Reciprocal transformations and flat metrics on Hurwitz spaces

abstract:
  We consider hydrodynamic systems which possess a local Hamiltonian structure
of Dubrovin-Novikov type. To such a system there are also associated an
infinite number of nonlocal Hamiltonian structures. We give necessary and
sufficient conditions so that, after a nonlinear transformation of the
independent variables, the reciprocal system still possesses a local
Hamiltonian structure of Dubrovin-Novikov type. We show that, under our
hypotheses, bi-hamiltonicity is preserved by the reciprocal transformation.
Finally we apply such results to reciprocal systems of genus g Whitham-KdV
modulation equations.


title: HS1857+5144: A hot and young pre-cataclysmic variable

abstract:
  We report the discovery of a new white dwarf/M dwarf binary, HS1857+5144,
identified in the Hamburg Quasar Survey (HQS). Time-resolved optical
spectroscopy and photometry were carried out to determine the properties of
this new cataclysmic variable progenitor pre-CV). The light curves of
HS1857+5144 display a sinusoidal variation with a period of Porb=383.52 min and
peak-to-peak amplitudes of 0.7 mag and 1.1 mag in the B-band and R-band,
respectively. The large amplitude of the brightness variation results from a
reflection effect on the heated inner hemisphere of the companion star,
suggesting a very high temperature of the white dwarf. Our radial velocity
study confirms the photometric period as the orbital period of the system. A
model atmosphere fit to the spectrum of the white dwarf obtained at minimum
light provides limits to its mass and temperature of Mwd=~0.6-1.0 Msun and
Twd=~70000-100000 K, respectively. The detection of HeII 4686 absorption
classifies the primary star of HS1857+5144 as a DAO white dwarf. Combining the
results from our spectroscopy and photometry, we estimate the mass of the
companion star and the binary inclination to be Msec=~0.15-0.30 Msun and
i=~45-55 deg, respectively. We classify HS1857+5144 as one of the youngest
pre-CV known to date. The cooling age of the white dwarf suggests that the
present system has just emerged from a common envelope phase ~10^5 yr ago.
HS1857+5144 will start mass transfer within or below the 2-3h period gap.