title: Trees of cylinders and canonical splittings

abstract:
  Let T be a tree with an action of a finitely generated group G. Given a
suitable equivalence relation on the set of edge stabilizers of T (such as
commensurability, co-elementarity in a relatively hyperbolic group, or
commutation in a commutative transitive group), we define a tree of cylinders
T_c. This tree only depends on the deformation space of T; in particular, it is
invariant under automorphisms of G if T is a JSJ splitting. We thus obtain
Out(G)-invariant cyclic or abelian JSJ splittings. Furthermore, T_c has very
strong compatibility properties (two trees are compatible if they have a common
refinement).


title: On Quasiconvexity and Relative Hyperbolic Structures

abstract:
  Let G be a group which is hyperbolic relative to a collection of subgroups A,
and it is also hyperbolic relative to a collection of subgroups B. Suppose that
the collection A contains B. We characterize, for subgroups of G, when
quasicovexity relative to A implies quasiconvexity relative to B. We also show
that quasiconvexity relative to B implies quasiconvexity relative to A. Some
applications are discussed.


title: Bounds on Light Dark Matter

abstract:
  In this talk we review existing cosmological and astrophysical bounds on
light (with the mass in keV - MeV range) and super-weakly interacting dark
matter candidates. A particular attention is paid to the sterile neutrino DM
candidate.


title: Dynamics of the inhomogeneous Dicke model

abstract:
  We study the time dynamics of a single boson coupled to a bath of two-level
systems (spins 1/2) with different excitation energies, described by an
inhomogeneous Dicke model. Analyzing the time-dependent Schrodinger equation
exactly we find that at resonance the boson decays in time to an oscillatory
state with a finite amplitude characterized by a single Rabi frequency if the
inhomogeneity is below a certain threshold. In the limit of small
inhomogeneity, the decay is suppressed and exhibits a complex (mainly
Gaussian-like) behavior, whereas the decay is complete and of exponential form
in the opposite limit. For intermediate inhomogeneity, the boson decay is
partial and governed by a combination of exponential and power laws.


title:
The homogenization of orthorhombic piezoelectric composites by the
  strong-property-fluctuation theory

abstract:
  The linear strong--property--fluctuation theory (SPFT) was developed in order
to estimate the constitutive parameters of certain homogenized composite
materials (HCMs) in the long--wavelength regime. The component materials of the
HCM were generally orthorhombic $mm2$ piezoelectric materials, which were
randomly distributed as oriented ellipsoidal particles. At the second--order
level of approximation, wherein a two--point correlation function and its
associated correlation length characterize the component material
distributions, the SPFT estimates of the HCM constitutive parameters were
expressed in terms of numerically--tractable two--dimensional integrals.
Representative numerical calculations revealed that: (i) the lowest--order SPFT
estimates are qualitatively similar to those provided by the corresponding
Mori--Tanaka homogenization formalism, but differences between the two
estimates become more pronounced as the component particles become more
eccentric in shape; and (ii) the second--order SPFT estimate provides a
significant correction to the lowest--order estimate, which reflects
dissipative losses due to scattering.


title:
Chiral Dynamics of the Polarizing Fracture Functions for Baryon
  Production

abstract:
  The concept of spin-directed momentum provides a useful and restrictive
framework for describing dynamical mechanisms that can lead to single-spin
observables. The value of this framework can be demonstrated by consideration
of the polarizing fracture functions that characterize the production of
polarized baryons in the target fragmentation region of semi-inclusive deep
inelastic scattering from an unpolarized target. When Bjorken x is chosen large
enough to indicate a hard scattering from a valence quark, the fracture
function formalism dynamically selects a quark-diquark basis for baryon
structure. Attention to sonstituent orbital angular momentum in the formation
process and its role in contribution to the transverse momentum of the produced
baryon illustrates important aspects of the generation of polarization
observables.


title: Scott and Swarup's regular neighbourhood as a tree of cylinders

abstract:
  Let G be a finitely presented group. Scott and Swarup have constructed a
canonical splitting of G which encloses all almost invariant sets over
virtually polycyclic subgroups of a given length. We give an alternative
construction of this regular neighbourhood, by showing that it is the tree of
cylinders of a JSJ splitting.


title:
Superconductivity induced by phosphorus doping and its coexistence with
  ferromagnetism in EuFe$_{2}$(As$_{0.7}$P$_{0.3}$)$_{2}$

abstract:
  We have studied EuFe$_{2}$(As$_{0.7}$P$_{0.3}$)$_{2}$ by the measurements of
x-ray diffraction, electrical resistivity, thermopower, magnetic
susceptibility, magnetoresistance and specific heat. Partial substitution of As
with P results in the shrinkage of lattice, which generates chemical pressure
to the system. It is found that EuFe$_{2}$(As$_{0.7}$P$_{0.3}$)$_{2}$ undergoes
a superconducting transition at 26 K, followed by ferromagnetic ordering of
Eu$^{2+}$ moments at 20 K. This finding is the first observation of
superconductivity stabilized by internal chemical pressure, and supplies a rare
example showing coexistence of superconductivity and ferromagnetism in the
ferro-arsenide family.


title: Integral-field spectroscopy of SLACS lenses

abstract:
  The combination of two-dimensional kinematics and gravitational lens
modelling permits detailed reconstruction of the phase-space structure of
early-type galaxies and sets constraints on the dark-matter distribution in
their inner regions. We describe a project which combines integral-field
spectroscopy from an ESO Large Programme using VIMOS on the VLT with deep HST
ACS and NICMOS images to study a sample of 17 early-type lens galaxies at
redshifts between 0.1 and 0.3, drawn from the Sloan Lens ACS survey (SLACS).


title:
Metallicities for 13 nearby open clusters from high-resolution
  spectroscopy of dwarf and giant stars. Stellar metallicity, stellar mass, and
  giant planets

abstract:
  We present a study of accurate stellar parameters and iron abundances for 39
giants and 16 dwarfs in the 13 open clusters IC2714, IC4651, IC4756, NGC2360,
NGC2423, NGC2447 (M93), NGC2539, NGC2682 (M67), NGC3114, NGC3680, NGC4349,
NGC5822, NGC6633. The analysis was done using a set of high-resolution and
high-S/N spectra obtained with the UVES spectrograph (VLT). These clusters are
currently being searched for planets using precise radial velocities. For all
the clusters, the derived average metallicities are close to solar.
Interestingly, the values derived seem to depend on the line-list used. This
dependence and its implications for the study of chemical abundances in giants
stars are discussed. We show that a careful choice of the lines may be crucial
for the derivation of metallicities for giant stars on the same metallicity
scale as those derived for dwarfs. Finally, we discuss the implications of the
derived abundances for the metallicity- and mass-giant planet correlation. We
conclude that a good knowledge of the two parameters is necessary to correctly
disentangle their influence on the formation of giant planets.


title: Finding critical points using improved scaling Ansaetze

abstract:
  Analyzing in detail the first corrections to the scaling hypothesis, we
develop accelerated methods for the determination of critical points from
finite size data. The output of these procedures are sequences of
pseudo-critical points which rapidly converge towards the true critical points.
In fact more rapidly than previously existing methods like the Phenomenological
Renormalization Group approach. Our methods are valid in any spatial
dimensionality and both for quantum or classical statistical systems. Having at
disposal fast converging sequences, allows to draw conclusions on the basis of
shorter system sizes, and can be extremely important in particularly hard cases
like two-dimensional quantum systems with frustrations or when the sign problem
occurs. We test the effectiveness of our methods both analytically on the basis
of the one-dimensional XY model, and numerically at phase transitions occurring
in non integrable spin models. In particular, we show how a new Homogeneity
Condition Method is able to locate the onset of the
Berezinskii-Kosterlitz-Thouless transition making only use of ground-state
quantities on relatively small systems.

categories: cond-mat.stat-mech cond-mat.str-el hep-th quant-ph


title: gamma* -> rhoT impact factor with twist three accuracy

abstract:
  We evaluate the impact factor of the transition gamma* -> rhoT taking into
account the twist 3 contributions. We show that a gauge invariant expression is
obtained with the help of QCD equations of motion. Our results are free of
end-point singularities. This opens the way to a consistent treatment of
factorization for exclusive processes with a transversally polarized vector
meson.


title: Flag Paraproducts

abstract:
  We describe the theory of "flag paraproducts" and their relationship with the
field of differential equations.


title: Starburst99 for Windows

abstract:
  We describe a Windows compatible version of the evolutionary synthesis code
Starburst99. Starburst99 for Windows was developed from the public UNIX based
version at STScI. We converted the original Fortran77 source code into a
version for a Win32 environment with an Absoft Fortran Pro x86 compiler.
Extensive testing showed no significant numerical differences in comparison
with the previous UNIX version. The software application consists of the source
code, executable, and a number of auxiliary files. The package installs on any
PC running Windows 2000, XP, or Vista and can be obtained as freeware at
http://www.stsci.edu/science/starburst/PCStarburst99.html. We give an overview
of the different running modes and provide instructions for getting started
with the initial set-up.


title: Emission line objects in NGC 6822. New Planetary Nebula candidates

abstract:
  Images obtained with the CTIO 4-m telescope and the MOSAIC-2 wide field
camera in [O III] 5007 and H\alpha on-band and off-band filters are analyzed to
search for emission lines objects in the galaxy NGC 6822. In particular we
search for PN candidates. In addition, data of a sub-sample of objects obtained
with ESO VLT-FORS2 are used to calibrate the MOSAIC imaging. A large number of
line emission regions were detected, for which we measured instrumental
magnitudes in all the filters. Based on some criteria to distinguish between
PNe and compact HII regions, we found 26 PN candidates, increasing the known
sample in 8 objects. Also we detected a number of compact HII regions and 20
stellar objects emitting in Halpha. For all the objects we present coordinates,
instrumental magnitudes and nebular [O III] and Halpha+[N II] fluxes. The
observed PNLF for the PN [O III] 5007 magnitudes and the cumulative PNLF were
calculated. We confirm that the PNLF presents a dip similar to the one detected
for the SMC at 2.5 mag down the maximum. The cumulative PNLF returns a value
M^\star_{5007}=-3.71^{+0.21}_{-0.42} for the peak absolute magnitude of the
PNLF which is faint compared to the value expected for galaxies with
metallicity similar to the one of NGC 6822 but similar within uncertainties.
  From our best fit to the observed PNLF we obtained a rough distance modulus
m-M = 23.64 ^{+0.23}_{-0.43} mag, which agrees within uncertainties with recent
values reported in the literature. The number of PN in the brightest 0.5 mag
normalized to the galactic bolometric luminosity, alpha_{0.5} was estimated to
be (3.8^{+0.90}_{-0.71}) E-9, which is similar to the values derived for
galaxies with recent star formation and small galaxies (M_B fainter than - 18
mag).


title:
Chiral Partners and their Electromagnetic Radiation -- Ingredients for a
  systematic in-medium calculation

abstract:
  It is argued that the chiral partners of the lowest-lying hadrons are
hadronic molecules and not three-quark or quark-antiquark states, respectively.
As an example the case of a_1 as the chiral partner of the rho is discussed.
Deconfinement -- or as a precursor large in-medium widths for hadronic states
-- is proposed as a natural way to accommodate for the fact that at chiral
restoration the respective in-medium spectra of chiral partners must become
degenerate. Ingredients for a systematic and self-consistent in-medium
calculation are presented with special emphasis on vector-meson dominance which
emerges from a recently proposed systematic counting scheme for the mesonic
sector including pseudoscalar and vector mesons as active degrees of freedom.


title: The coupled-channel analysis of $D_s$ and $B_s$ mesons

abstract:
  In the framework of the coupled channel model the mass shifts of the
$P$--wave excitations of $D_s$ and $B_s$ mesons have been calculated. The
corresponding coupling to $DK$ and $BK$ channels is provided by the effective
chiral Lagrangian which is deduced from QCD and does not contain fitting
parameters. The strong mass shifts down for $0^+$ and ${1^+}'$ states have been
obtained, while ${1^+}"$ and $2^+$ states remain almost at rest. Two factors
are essential for large mass shifts: strong coupling of the $0^+$ and $1^{+'}$
states to the $S$-wave decay channel, containing a Nambu-Goldstone meson, and
the chiral flip transitions due to the bispinor structure of both heavy-light
mesons. The masses $M(B^*_s(0^+))=5710(15)$ MeV and $M(B_s(1^{+'}))=5730(15)$
MeV are predicted. Experimental limit on the width $\Gamma(D_{s1}(2536))<2.3$
MeV puts strong restrictions on admittable mixing angle between the $1^+$ and
$1^{+'}$ states.


title: Solitonic ground states in (color-) superconductivity

abstract:
  We present a general framework for analyzing inhomogeneous (color-)
superconducting phases in mean-field approximation without restriction to the
Ginzburg-Landau approach. As a first application, we calculate real gap
functions with general one-dimensional periodic structures for a
3+1-dimensional toy model having two fermion species. The resulting solutions
are energetically favored against homogeneous superconducting (BCS) and normal
conducting phases in a window for the chemical potential difference which is
about twice as wide as for the most simple plane-wave ansatz ("Fulde-Ferrell
phase"). At the lower end of this window, we observe the formation of a soliton
lattice and a continuous phase transition to the BCS phase. At the higher end
of the window the gap functions are sinusoidal, and the transition to the
normal conducting phase is of first order. We also discuss the quasiparticle
excitation spectrum in the inhomogeneous phase. Finally, we compare the gap
functions with the known analytical solutions of the 1+1-dimensional theory.


title: Gravity Waves from Chain Inflation

abstract:
  Chain inflation proceeds through a series of first order phase transitions,
which can release considerable gravitational waves (GW). We demonstrate that
bubble collisions can leave an observable signature for future high-frequency
probes of GWs, such as advanced LIGO, LISA and BBO. A "smoking gun" for chain
inflation would be wiggles in the spectrum (and consequently in the tensor
spectral index) due to the multiple phase transitions. The spectrum could also
be distinguished from a single first order phase transition by a small
difference in the amplitude at low frequency. A second origin of GWs in chain
inflation are tensor modes from quantum fluctuations; these GW can dominate and
be observed on large scales. The consistency relation between scalar and tensor
modes is different for chain inflation than for standard rolling models and is
testable by Cosmic Microwave Background experiments. If inflation happened
through a series of rapid tunnelings in the string landscape, future high
frequency probes of GW can shed light on the structure of the landscape.


title:
A Realistic Cosmological Model Based on Observations and Some Theory
  Developed Over the Last 90 Years

abstract:
  This meeting is entitled "A Century of Cosmology." But most of the papers
being given here are based on work done very recently and there is really no
attempt being made to critically review what has taken place in the last 90 or
100 years. Instead, in general the participants accept without question that
cosmology equates to "hot big bang cosmology" with all of its bells and
whistles. All of the theory and the results obtained from observations are
interpreted on the assumption that this extremely popular model is the correct
one, and observers feel that they have to interpret its results in terms of
what this theory allows. No one is attempting to seriously test the model with
a view to accepting it or ruling it out. They are aware, as are the theorists,
that there are enough free parameters available to fix up almost any model of
the type.
  The current scheme given in detail for example by Spergel et al (206, 2007)
demonstrates this. How we got to this stage is never discussed, and little or
no attention is paid to the observations obtained since the 1960s on activity
in the centers of galaxies and what they imply. We shall show that they are an
integral part of a realistic cosmological model. In this paper I shall take a
different approach, showing first how cosmological ideas have developed over
the last 90 years and where mistakes have been made. I shall conclude with a
realistic model in which all of the observational material is included, and
compare it with the popular model. Not surprisingly I shall show that there
remain many unsolved problems, and previously unexpected observations, most of
which are ignored or neglected by current observers and theorists, who believe
that the hot big bang model must be correct.


title: Composite CDMA - A statistical mechanics analysis

abstract:
  Code Division Multiple Access (CDMA) in which the spreading code assignment
to users contains a random element has recently become a cornerstone of CDMA
research. The random element in the construction is particular attractive as it
provides robustness and flexibility in utilising multi-access channels, whilst
not making significant sacrifices in terms of transmission power. Random codes
are generated from some ensemble, here we consider the possibility of combining
two standard paradigms, sparsely and densely spread codes, in a single
composite code ensemble. The composite code analysis includes a replica
symmetric calculation of performance in the large system limit, and
investigation of finite systems through a composite belief propagation
algorithm. A variety of codes are examined with a focus on the high
multi-access interference regime. In both the large size limit and finite
systems we demonstrate scenarios in which the composite code has typical
performance exceeding sparse and dense codes at equivalent signal to noise
ratio.

categories: cond-mat.dis-nn cond-mat.stat-mech cs.IT math.IT


title:
Properties of warm absorbers in active galaxies: a systematic stability
  curve analysis

abstract:
  Signatures of warm absorbers are seen in soft X-ray spectra of about half of
all Seyfert1 galaxies observed and in some quasars and blazars. We use the
thermal equilibrium curve to study the influence of the shape of the ionizing
continuum, density and the chemical composition of the absorbing gas on the
existence and nature of the warm absorbers. We describe circumstances in which
a stable warm absorber can exist as a multiphase medium or one with continuous
variation in pressure. In particular we find the following results: i) the warm
absorber exists only if the spectral index of the X-ray power-law ionizing
continuum $\alpha > 0.2$ and has a multiphase nature if $\alpha \sim 0.8$,
which interestingly is the spectral index for most of the observed Seyfert 1
galaxies; ii) thermal and ionization states of highly dense warm absorbers are
sensitive to their density if the ionizing continuum is sufficiently soft, i.e.
dominated by the ultraviolet iii) absorbing gas with super-Solar metallicity is
more likely to have a multiphase nature; iv) the nature of the warm absorber is
significantly influenced by the absence of iron and associated elements which
are produced in the later stages of star formation history in supernovae of
type Ia.


title: On the Safe Use of Inconsistent Mathematics

abstract:
  A method is presented for using the consistent part of inconsistent axiomatic
systems.


title:
A Simple Proof of the Stability of Solitary Waves in the
  Fermi-Pasta-Ulam model near the KdV Limit

abstract:
  By combining results of Mizumachi on the stability of solitons for the Toda
lattice with a simple rescaling and a careful control of the KdV limit we give
a simple proof that small amplitude, long-wavelength solitary waves in the
Fermi-Pasta-Ulam (FPU) model are linearly stable and hence by the results of
Friesecke and Pego that they are also nonlinearly, asymptotically stable.


title: Regularity of smooth curves in biprojective spaces

abstract:
  Maclagan and Smith \cite{MaclaganSmith} developed a multigraded version of
Castelnuovo-Mumford regularity. Based on their definition we will prove in this
paper that for a smooth curve $C\subseteq \P^a\times\P^b$ $(a, b\geq 2)$ of
bidegree $(d_1,d_2)$ with nondegenerate birational projections the ideal sheaf
$\mathcal{I}_{C|\P^a\times\P^b}$ is $(d_2-b+1,d_1-a+1)$-regular. We also give
an example showing that in some cases this bound is the best possible.


title: An 84 microGauss Magnetic Field in a Galaxy at Redshift z=0.692

abstract:
  The magnetic field pervading our Galaxy is a crucial constituent of the
interstellar medium: it mediates the dynamics of interstellar clouds, the
energy density of cosmic rays, and the formation of stars. The field associated
with ionized interstellar gas has been determined through observations of
pulsars in our Galaxy. Radio-frequency measurements of pulse dispersion and the
rotation of the plane of linear polarization, i.e., Faraday rotation, yield an
average value B ~ 3 microGauss. The possible detection of Faraday rotation of
linearly polarized photons emitted by high-redshift quasars suggests similar
magnetic fields are present in foreground galaxies with redshifts z > 1. As
Faraday rotation alone, however, determines neither the magnitude nor the
redshift of the magnetic field, the strength of galactic magnetic fields at
redshifts z > 0 remains uncertain. Here we report a measurement of a magnetic
field of B ~ 84 microGauss in a galaxy at z =0.692, using the same
Zeeman-splitting technique that revealed an average value of B = 6 microGauss
in the neutral interstellar gas of our Galaxy. This is unexpected, as the
leading theory of magnetic field generation, the mean-field dynamo model,
predicts large-scale magnetic fields to be weaker in the past rather than
stronger.


title: The Phononic Casimir Effect: An Analog Model

abstract:
  We discuss the quantization of sound waves in a fluid with a linear
dispersion relation and calculate the quantum density fluctuations of the fluid
in several cases. These include a fluid in its ground state. In this case, we
discuss the scattering cross section of light by the density fluctuations, and
find that in many situations it is small compared to the thermal fluctuations,
but not negligibly small and might be observable at room temperature. We also
consider a fluid in a squeezed state of phonons and fluids containing
boundaries. We suggest that the latter may be a useful analog model for better
understanding boundary effects in quantum field theory. In all cases involving
boundaries which we consider, the mean squared density fluctuations are reduced
by the presence of the boundary. This implies a reduction in the light
scattering cross section, which is potentially an observable effect.


title: Exclusive photoproduction of dileptons at high energies

abstract:
  The exclusive photoproduction of lepton pairs on nucleon and nucleus target
is investigated within the high energy color dipole approach, where the main
physical quantity is the dipole-target elastic scattering amplitude that
captures the main features of the dependence on atomic number A, on energy and
on momentum transfer t. These calculations are input in predictions for
electromagnetic interactions in pp and AA collisions to be measured at the LHC.


title: Material point model and the geometry of the entropy form

abstract:
  In this work we investigate the material point model and exploit the
geometrical meaning of the "entropy form" introduced by B.Coleman and R.Owen.
We analyze full and partial integrability (closeness) condition of the entropy
form for the model of thermoelastic point and for the the deformable
ferroelectric crystal media point. We show that the thermodynamical phase space
(TPS) introduced by R.Hermann and widely exploited by R. Mrugala with his
collaborators and other researchers, extended possibly by time, with its
canonical contact structure is an appropriate setting for the development of
material point models in different physical situations. This allows us to
formulate the model of a material point and the corresponding entropy form in
terms similar to those of the homogeneous thermodynamics. Closeness condition
of the entropy form is reformulated as the requirement that the admissible
processes curves belongs to the constitutive surface S of the model.
  Our principal result is the description of the constitutive surfaces S of the
material point model as the Legendre submanifolds of the TPS shifted by the
flow of Reeb vector field. This shift is controlled, at the points of Legendre
submanifold by the entropy production function $\sigma$.


title:
Crystallinity and Crystallographic Texture in Isotactic Polypropylene
  during Deformation and Heating

abstract:
  The development of the crystallinity and of the crystallographic orientation
of isotactic polypropylene (iPP) during rolling deformation and subsequent heat
treatment is studied. The experiments are conducted by using X-ray diffraction
with an area detector. The evolution of crystallographic orientation is tracked
by calculating the pole figures and by applying a quantitative 3D texture
component fit method. The rolling orientation after a true strain of -1.5
mainly consists of the (010)[001], (130)[001], and [001]//RD fiber components
(RD: rolling direction). The results reveal that the crystallinity drastically
decreases during rolling. We suggest that decrystallization (disaggregation) is
a deformation mechanism which takes place as a microscopic alternative to
crystallographic intralamellar shear depending on the orientation of the
lamellae relative to the imposed deformation tensor. Heat treatment after
rolling leads to the recrystallization of amorphous material and to a strong
enhancement of the fiber orientation component. The recrystallization
orientation is explained in terms of an oriented nucleation mechanism where
amorphous material aligns along existing crystalline lamellae blocks which
prevailed during the preceding deformation.


title: Chiral shifts in heavy-light mesons

abstract:
  The mass shifts of the $P$-wave $D_s$ and $B_s$ mesons due to coupling to
$DK$ and $BK$ channels are calculated in the coupling channel model without
fitting parameters. The strong mass shifts down for $0^+$ and ${1^+}'$ states
have been obtained, while ${1^+}"$ and $2^+$ states remain almost in situ. The
masses of $0^+$ and ${1^+}'$ states of $B_s$ mesons have been predicted.


title: Fusion at deep subbarrier energies: potential inversion revisited

abstract:
  For a single potential barrier, the barrier penetrability can be inverted
based on the WKB approximation to yield the barrier thickness. We apply this
method to heavy-ion fusion reactions at energies well below the Coulomb barrier
and directly determine the inter-nucleus potential between the colliding
nuclei. To this end, we assume that fusion cross sections at deep subbarrier
energies are governed by the lowest barrier in the barrier distribution. The
inverted inter-nucleus potentials for the $^{16}$O +$^{144}$Sm and $^{16}$O
+$^{208}$Pb reactions show that they are much thicker than phenomenological
potentials. We discuss a consequence of such thick potential by fitting the
inverted potentials with the Bass function.


title: Introducing doubt in Bayesian model comparison

abstract:
  There are things we know, things we know we don't know, and then there are
things we don't know we don't know. In this paper we address the latter two
issues in a Bayesian framework, introducing the notion of doubt to quantify the
degree of (dis)belief in a model given observational data in the absence of
explicit alternative models. We demonstrate how a properly calibrated doubt can
lead to model discovery when the true model is unknown.


title: Fixing D7 Brane Positions by F-Theory Fluxes

abstract:
  To do realistic model building in type IIB supergravity, it is important to
understand how to fix D7-brane positions by the choice of fluxes. More
generally, F-theory model building requires the understanding of how fluxes
determine the singularity structure (and hence gauge group and matter content)
of the compactification. We analyse this problem in the simple setting of
M-theory on K3xK3. Given a certain flux which is consistent with the F-theory
limit, we can explicitly derive the positions at which D7 branes or stacks of
D7 branes are stabilised. The analysis is based on a parameterization of the
moduli space of type IIB string theory on T^2/Z_2 (including D7-brane
positions) in terms of the periods of integral cycles of M-theory on K3. This
allows us, in particular, to select a specific desired gauge group by the
choice of flux numbers.


title: Flavor Hierarchy From F-theory

abstract:
  It has recently been shown that F-theory based constructions provide a
potentially promising avenue for engineering GUT models which descend to the
MSSM. In this note we show that in the presence of background fluxes, these
models automatically achieve hierarchical Yukawa matrices in the quark and
lepton sectors. At leading order, the existence of a U(1) symmetry which is
related to phase rotations of the internal holomorphic coordinates at the brane
intersection point leads to rank one Yukawa matrices. Subleading corrections to
the internal wave functions from variations in the background fluxes generate
small violations of this U(1), leading to hierarchical Yukawa structures
reminiscent of the Froggatt-Nielsen mechanism. The expansion parameter for this
perturbation is in terms of alpha_(GUT)^(1/2). Moreover, we naturally obtain a
hierarchical CKM matrix with V_(12) ~ V_(21) ~ epsilon, V_(23) ~ V_(32) ~
epsilon^(2), V_(13) ~ V_(31) ~ epsilon^(3), where epsilon ~ alpha_(GUT)^(1/2),
in excellent agreement with observation.


title:
Medium-modified average multiplicity and multiplicity fluctuations in
  jets

abstract:
  The energy evolution of average multiplicities and multiplicity fluctuations
in jets produced in heavy-ion collisions is investigated from a toy
QCD-inspired model. In this model, we use modified splitting functions
accounting for medium-enhanced radiation of gluons by a fast parton which
propagates through the quark gluon plasma. The leading contribution of the
standard production of soft hadrons is enhanced by a factor $\sqrt{N_s}$ while
next-to-leading order (NLO) corrections are suppressed by $1/\sqrt{N_s}$, where
the parameter $N_s>1$ accounts for the induced-soft gluons in the medium. Our
results for such global observables are cross-checked and compared with their
limits in the vacuum.


title:
Large-Distance Asymptotic Behavior of the Correlation Functions of 1D
  Impenetrable Anyons at Finite Temperatures

abstract:
  The large-distance asymptotic behavior of the field-field correlators has
been computed for one-dimensional impenetrable anyons at finite temperatures.
The asymptotic behavior agrees with the predictions of conformal field theory
at low temperatures and reproduces the known results for impenetrable bosons
and free fermions in appropriate limits. We have also obtained an integrable
system of partial nonlinear differential equations which completely
characterizes the 2-point correlation functions. The system is the same as for
bosons but with different initial conditions.

categories: cond-mat.stat-mech math-ph math.MP quant-ph


title:
Emission-lines calibrations of the Star Formation Rate from the Sloan
  Digital Sky Survey

abstract:
  Our goal is to study the existing star formation rate calibrations based on
emission-line luminosities and to provide new ones. We use the SDSS data
release DR4, which gives star formation rates and emission-line luminosities of
more than 100000 star-forming galaxies. We confirm that the best results are
obtained with the Halpha calibration. This calibration has an uncertainty of
0.17 dex. We show that one has to check carefully the method used to derive the
dust attenuation and to use the adequate calibration: in some cases, the
standard scaling law has to be replaced by a more general power law. When data
is corrected for dust attenuation but the Halpha emission line not observed,
the use of the Hbeta emission line, has to be preferred to the [OII]3727
emission line. In the case of uncorrected data, the correction for dust
attenuation can be assumed as a constant value but we show that such method
leads to poor results, in terms of dispersion and residual slope.
Self-consistent corrections, based e.g. on the absolute magnitude, give better
results in terms of dispersion but still suffer from systematic shifts, and/or
residual slopes. The best results with data not corrected for dust attenuation
are obtained when using the observed [OII]3727 and Hbeta emission lines
together. This calibration has an uncertainty of 0.23 dex.


title:
Exceptional divisors which are not uniruled belong to the image of the
  Nash map

abstract:
  We prove that, if X is a variety over an uncountable algebraically closed
field k of characteristic zero, then any irreducible exceptional divisor E on a
resolution of singularities of X which is not uniruled, belongs to the image of
the Nash map, i.e. corresponds to an irreducible component of the space of arcs
on X centered in Sing X. This reduces the Nash problem of arcs to understanding
which uniruled essential divisors are in the image of the Nash map, more
generally, how to determine the uniruled essential divisors from the space of
arcs.


title:
Individual addressing of ions using magnetic field gradients in a
  surface-electrode ion trap

abstract:
  Dense array of ions in microfabricated traps represent one possible way to
scale up ion trap quantum computing. The ability to address individual ions is
an important component of such a scheme. We demonstrate individual addressing
of trapped ions in a microfabricated surface-electrode trap using a magnetic
field gradient generated on-chip. A frequency splitting of 310(2) kHz for two
ions separated by 5 um is achieved. Selective single qubit operations are
performed on one of two trapped ions with an average of 2.2+/-1.0% crosstalk.
Coherence time as measured by the spin-echo technique is unaffected by the
field gradient.


title: Giant Magnons in AdS4 x CP3: Embeddings, Charges and a Hamiltonian

abstract:
  This paper studies giant magnons in CP3, which in all known cases are old
solutions from S5 placed into two- and three-dimensional subspaces of CP3,
namely CP1, RP2 and RP3. We clarify some points about these subspaces, and
other potentially interesting three- and four-dimensional subspaces. After
confirming that E-(J1-J4)/2 is a Hamiltonian for small fluctuations of the
relevant 'vacuum' point particle solution, we use it to calculate the
dispersion relation of each of the inequivalent giant magnons. We comment on
the embedding of finite-J solutions, and use these to compare string solutions
to giant magnons in the algebraic curve.


title: Solar neutrinos and the solar composition problem

abstract:
  Standard solar models (SSM) are facing nowadays a new puzzle: the solar
composition problem. New determinations of solar metal abundances lead SSM
calculations to conflict with helioseismological measurements, showing
discrepancies that extend from the convection zone to the solar core and can
not be easily assigned to deficiencies in the modelling of the solar convection
zone. We present updated solar neutrino fluxes and uncertainties for two SSM
with high (old) and low (new) solar metallicity determinations. The
uncertainties in iron and carbon abundances are the largest contribution to the
uncertainties of the solar neutrino fluxes. The uncertainty on the ^14N+p ->
^15O+g rate is the largest of the non-composition uncertainties to the CNO
neutrino fluxes. We propose an independent method to help identify which SSM is
the correct one. Present neutrino data can not distinguish the solar neutrino
predictions of both models but ongoing measurements can help to solve the
puzzle.


title:
Time evolution of the energy density inside a non-static cavity with a
  thermal, coherent and a Schrodinger cat state

abstract:
  In this paper we investigate the time evolution of the energy density for a
real massless scalar field in a two-dimensional spacetime, inside a non-static
cavity, taking as basis the exact numerical approach purposed by Cole and
Schieve. Considering Neunmann and Dirichlet boundary conditions, we investigate
the following initial states of the field: vacuum, thermal state, the coherent
state and the Schrodinger cat state.


title:
A Merger Tree with Microsolar Mass Resolution: Application to
  $\gamma$-ray Emission from Subhalo Population

abstract:
  The hierarchical growth of dark matter haloes, in which galaxies are hosted,
has been studied and modeled using various approaches. In this paper we use a
modified version the Sheth & Lemson algorithm for a $\mathrm{\Lambda}$ cold
dark matter power spectrum, and model the growth of a Milky-Way sized halo with
microsolar mass resolution, corresponding to the typical Jeans mass for a dark
matter Weakly Interacting Massive Particle with mass of 100 GeV. We then
compute the \emph{unevolved} subhalo mass function and build-up a Milky-Way
halo placing and evolving its satellites. This subhalo population is used to
study the $\gamma$-ray emission from dark matter annihilation. In this case,
the subhaloes which populate the host halo have been computed considering only
progenitor haloes accreted by the main branch of the tree, so as to correctly
treat the embedding of sub-subhaloes inside subhaloes. Each subhalo will indeed
host atthe present-time sub-subhaloes accreted when it was an isolated system.
In order to compute the sub-subhalo population of a Milky-Way dwarf galaxy,
like Draco, and to study its $\gamma$-ray emission, we first estimate the Draco
virial mass at merging redshift $z_m$ and then we run the merger tree from
$z_m$ following the halo down to the dark matter Jeans mass. We then study the
effect on the Fermi-LAT (GLAST) detectability for both subhaloes in the
Milky-Way and in Draco, and we show how subhaloes cannot be responsible for the
boost factor needed for detection.


title:
Determining Reheating Temperature at LHC with Axino or Gravitino Dark
  Matter

abstract:
  After a period of inflationary expansion, the Universe reheated and reached
full thermal equilibrium at the reheating temperature. In this talk, based on
the paper, arXiv:0710.3349, we point out that, in the context of effective
low-energy supersymmetric models, LHC measurements may allow one to determine
reheating temperature as a function of the mass of the dark matter particle
assumed to be either an axino or a gravitino. An upper bound on their mass and
on the reheating temperature may also be derived.


title:
Asymptotic stability of oscillations of two-bodies vibrating screen with
  one-sided obstacle without clearances

abstract:
  We prove asymptotic stability of periodic oscillations in two-bodies
vibrating screen model under assumption that the frequencies w1 and w2 of the
generating system (without obstacle and periodic driving) satisfy the
assumption w1:w2=1:2. We also assume that the frequency of the external
periodic driving equals to w1. These settings correspond to nonlinear resonance
which is a well known phenomenon in industrial implementation of the vibrating
screen. The justification is performed over nonsmooth analog of the second
Bogolyubov's theorem proposed by the author in his previous papers. It is
rigorously proven that the periodic oscillations obtained have two frequencies,
in contrast with the case when the obtacle is absent.


title: Recent Progress in Lattice QCD Thermodynamics

abstract:
  This review gives a critical assessment of the current state of lattice
simulations of QCD thermodynamics and what it teaches us about hot hadronic
matter. It outlines briefly lattice methods for studying QCD at nonzero
temperature and zero baryon number density with particular emphasis on
assessing and reducing cutoff effects. It discusses a variety of difficulties
with methods for determining the transition temperature. It uses results
reported recently in the literature and at this conference for illustration,
especially those from a major study carried out by the HotQCD collaboration.


title: What particles that never met "know" of one another?

abstract:
  An experiment proposed by Yurke and Stoler, and similar to that realized
experimentally by Sciarrino et al., is analyzed. In Sciarrino's realization,
identical photons from a degenerated down-conversion pair are used, i.e. the
photons met in the past. In the experiment analyzed here the particles are also
identical, but from different sources. As long as one can tell from which
source came each particle, the joint wave function remains factorizable.
However, a configuration is created in which one cannot tell anymore which
particle came from which source. As a result, the wave function becomes
non-factorizable, symmetrical (for bosons) or antisymmetrical (for fermions).
In part of the cases the situation is even more surprising: the particles never
meet, s.t. the symmetry (antisymmetry) is produced at-a-distance without the
particles having had the possibility to interact in any way.


title: Calibration of a Highly Granular Hadronic Calorimeter with SiPM Readout

abstract:
  A highly granular hadronic calorimeter (HCAL) based on scintillator tiles
with individual readout by silicon photomultipliers (SiPMs) has been
constructed by the CALICE collaboration and has been tested extensively in
particle beams at CERN. The 7608 SiPMs coupled to scintillator tiles in the
approximately 1 cubic meter large calorimeter allow large sample studies of
behavior of these devices under varying voltage and temperature as well as
their saturation behavior. We also present detailed studies of the temperature
dependence of the calorimeter signal in muon and hadron beams. The calibration
of the full calorimeter using muons is discussed. In addition, a novel method
for calibration and detector studies using minimum-ionizing track segments in
hadronic showers, is explored.


title: The Forward GEM Tracker of STAR at RHIC

abstract:
  The STAR experiment at the Relativistic Heavy Ion Collider (RHIC) at
Brookhaven National Laboratory (BNL) is in the process of designing and
constructing a forward tracking system based on triple GEM technology. This
upgrade is necessary to give STAR the capability to reconstruct and identify
the charge sign of W bosons over an extended rapidity range through their
leptonic decay mode into an electron (positron) and a neutrino. This will allow
a detailed study of the flavor-separated spin structure of the proton in
polarized p + p collisions uniquely available at RHIC. The Forward GEM Tracker
FGT will consist of six triple GEM disks with an outer radius of ~39 cm and an
inner radius of ~10.5 cm, arranged along the beam pipe, covering the
pseudo-rapidity range from 1.0 to 2.0 over a wide range of collision vertices.
The GEM foils will be produced by Tech-Etch, Inc. Beam tests with test
detectors using 10 cm x 10 cm Tech-Etch GEM foils and a two dimensional
orthogonal strip readout have demonstrated a spatial resolution of 70 um or
better and high efficiency.


title: Is the Missing Ultra-Red Material Colorless Ice?

abstract:
  The extremely red colors of some transneptunian objects and Centaurs are not
seen among the Jupiter family comets which supposedly derive from them. Could
this mismatch result from sublimation loss of colorless ice? Radiative transfer
models show that mixtures of volatile ice and nonvolatile organics could be
extremely red, but become progressively darker and less red as the ice
sublimates away.


title:
Finite Square Lattice Vertex Cover by a Baseline Set Defined With a
  Minimum Sublattice

abstract:
  Each straight infinite line defined by two vertices of a finite square point
lattice contains (covers) these two points and a - possibly empty - subset of
points that happen to be collinear to these. This work documents vertex subsets
of minimum order such that the sum of the infinite straight lines associated
with the edges of their complete subgraph covers the entire set of vertices
(nodes). This is an abstraction to the problem of sending a light signal to all
stations (receivers) in a square array with a minimum number of stations also
equipped with transmitters to redirect the light to other transmitters.


title:
Stability structures, motivic Donaldson-Thomas invariants and cluster
  transformations

abstract:
  We define new invariants of 3d Calabi-Yau categories endowed with a stability
structure. Intuitively, they count the number of semistable objects with fixed
class in the K-theory of the category ("number of BPS states with given charge"
in physics language). Formally, our motivic DT-invariants are elements of
quantum tori over a version of the Grothendieck ring of varieties over the
ground field. Via the quasi-classical limit "as the motive of affine line
approaches to 1" we obtain numerical DT-invariants which are closely related to
those introduced by Behrend. We study some properties of both motivic and
numerical DT-invariants including the wall-crossing formulas and integrality.
We discuss the relationship with the mathematical works (in the
non-triangulated case) of Joyce, Bridgeland and Toledano-Laredo, as well as
with works of physicists on Seiberg-Witten model (string junctions),
classification of N=2 supersymmetric theories (Cecotti-Vafa) and structure of
the moduli space of vector multiplets. Relating the theory of 3d Calabi-Yau
categories with distinguished set of generators (called cluster collection)
with the theory of quivers with potential we found the connection with cluster
transformations and cluster varieties (both classical and quantum).


title: Stationary waves in a supersonic flow of a two-component Bose gas

abstract:
  A stationary wave pattern occurring in a flow of a two-component
Bose-Einstein condensate past an obstacle is studied. We consider the general
case of unequal velocities of two superfluid components. The Landau criterium
applied to the two-component system determines a certain region in the velocity
space in which superfluidity may take place. Stationary waves arise out of this
region, but under the additional condition that the relative velocity of the
components does not exceed some critical value. Under increase of the relative
velocity the spectrum of the excitations becomes complex valued and the
stationary wave pattern is broken. In case of equal velocities two sets of
stationary waves that correspond to the lower and the upper Bogolyubov mode can
arise. If one component flows and the other is at rest only one set of waves
may emerge. Two or even three interfere sets of waves may arise if the
velocities approximately of equal value and the angle between the velocities is
close to pi/2. In two latter cases the stationary waves correspond to the lower
mode and the densities of the components oscillate out-of-phase. The ratio of
amplitudes of the components in the stationary waves is computed. This quantity
depends on the relative velocity, is different for different sets of waves, and
varies along the crests of the waves. For the cases where two or three waves
interfere the density images are obtained.


title: The switching dynamics of the bacterial flagellar motor

abstract:
  Many swimming bacteria are propelled by flagellar motors that stochastically
switch between the clockwise and counterclockwise rotation direction. While the
switching dynamics are one of the most important characteristics of flagellar
motors, the mechanisms that control switching are poorly understood. We present
a statistical-mechanical model of the flagellar rotary motor, which consists of
a number of stator proteins that drive the rotation of a ring of rotor
proteins, which in turn drives the rotation of a flagellar filament. At the
heart of our model is the assumption that the rotor protein complex can exist
in two conformational states corresponding to the two respective rotation
directions, and that switching between these states depends on interactions
with the stator proteins. This naturally couples the switching dynamics to the
rotation dynamics, making the switch sensitive to torque and speed. Another key
element of our model is that after a switching event, it takes time for the
load to build up, due to polymorphic transitions of the filament. Our model
predicts that this slow relaxation dynamics of the filament, in combination
with the load dependence of the switching frequency, leads to a characteristic
switching time, in agreement with recent observations.


title: Theory Summary: International Symposium on Multiparticle Dynamics 2008

abstract:
  I summarize the theory talks presented at the International Symposium on
Multiparticle Dynamics 2008.


title: On the noncommutative geometry of square superpotential algebras

abstract:
  A superpotential algebra is square if its quiver admits an embedding into a
two-torus such that the image of its underlying graph is a square grid,
possibly with diagonal edges in the unit squares; examples are provided by
dimer models in physics. Such an embedding reveals much of the algebras
representation theory through a device we introduce called an impression. Let A
be a square superpotential algebra, Z its center, and \mathfrak{m} the maximal
ideal at the origin of Spec(Z). Using an impression, we give a classification
of all simple A-modules up to isomorphism, and give algebraic and homological
characterizations of the simple A-modules of maximal k-dimension; show that Z
is a 3-dimensional normal toric domain and Z_{\mathfrak{m}} is Gorenstein, by
determining transcendence bases and Z-regular sequences; and show that
A_{\mathfrak{m}} is a noncommutative crepant resolution of Z_{\mathfrak{m}},
and thus a local Calabi-Yau algebra.
  A particular class of square superpotential algebras, the Y^{p,q} algebras,
is considered in detail. We show that the Azumaya and smooth loci of the
centers coincide, and propose that each ramified maximal ideal sitting over the
singular locus is the exceptional locus of a blowup shrunk to zero size.


title:
Magnetic Moments of Delta and Omega^- Baryons with Dynamical Clover
  Fermions

abstract:
  We calculate the magnetic dipole moment of the Delta(1232) and Omega^-
baryons with 2+1-flavors of clover fermions on anisotropic lattices using a
background magnetic field. This is the first dynamical calculation of these
magnetic moments using a background field technique. The calculation for
Omega^- is done at the physical strange quark mass, with the result in units of
the physical nuclear magneton mu_Omega^-= -1.93(8)(12) (where the first error
is statistical and the second is systematic) compared to the experimental
number: -2.02(5). The Delta has been studied at three unphysical quark masses,
corresponding to pion mass m_pi = 366, 438, and 548 MeV. The pion mass
dependence is compared with the behavior obtained from chiral effective field
theory.


title: An agent-based approach to food web assembly

abstract:
  An agent-based model of population dynamics is presented. The model has as
its expected behaviour the population dynamics of the equation-based Webworld
model, within which large communities of species can be grown on evolutionary
time scales. Such communities can be used in the agent-based model without
disrupting the food web structure, and hence a unified model of evolutionary
time and individual-based dynamics can be realised. Individuals encounter
potential prey, and optimal foraging strategies are arrived at through natural
selection.


title: Weak Coupling Casimir Energies for Finite Plate Configurations

abstract:
  We derive and use an extremely simplified formula for the interaction Casimir
energy for two separate bodies in the weak coupling regime for massless scalar
fields. We derive closed form solutions for a general arrangement of two
$\delta$-function plates finite in one direction and infinite in another. We
examine the situation of two parallel plates finite in both transverse
directions.


title:
MMT/AO 5 micron Imaging Constraints on the Existence of Giant Planets
  Orbiting Fomalhaut at ~13-40 AU

abstract:
  A candidate < 3 Jupiter mass, extrasolar planet was recently imaged by Kalas
et al. (2008) using HST/ACS at 12.7" (96 AU) separation from the nearby (d =
7.7 pc) young (~200 Myr) A2V star Fomalhaut. Here we report results from M-band
(4.8 micron) imaging of Fomalhaut on 5 Dec 2006 using the Clio IR imager on the
6.5-m MMT with the adaptive secondary mirror. Our images are sensitive to giant
planets at orbital radii comparable to the outer solar system (~5-40 AU).
Comparing our 5-sigma M-band photometric limits to theoretical evolutionary
tracks for substellar objects, our results rule out the existence of planets
with masses greater than 2 Jupiter masses, from ~13-40 AU and objects greater
than 13 Jupiter masses from ~8-40 AU.


title: Renormalisation Group Analysis of Supersymmetric Particle Interactions

abstract:
  In the Minimal Supersymmetric Standard Model (MSSM), there are numerous
sources of flavour-violation in addition to the usual Kobayashi-Maskawa mixing
matrix of the Standard Model. We reexamine the renormalisation group equations
(RGEs) with a view to investigating flavour effects in a supersymmetric theory
with an arbitrary flavour structure at some high scale. To incorporate
(two-loop sized) threshold effects in the one-loop RGEs, we calculate the
beta-functions using a sequence of (non-supersymmetric) effective theories with
heavy particles decoupled at the scale of their mass, keeping track of the fact
that many couplings (such as gauge and gaugino couplings) which are equal in an
exact supersymmetric theory may no longer be equal once the supersymmetry
(SUSY) is broken. We find that this splitting, which is ignored in the
literature, may be larger than two-loop terms that are included. In addition,
gaugino couplings develop flavour structure that is absent without including
decoupling effects. A program (to be incorporated into ISAJET) has been
developed, which includes flavour-violating couplings of superparticles and
solves the two-loop threshold RGEs subject to specified high scale inputs. The
weak scale flavour structure derived in this way can be applied to the study of
flavour-changing decays of SUSY particles. As an illustration, we revisit the
branching ratio of the flavour-violating decay of the top squark. We find that,
in the minimal supergravity (mSUGRA) class of models, previous estimates for
the width of this decay have been too large by a factor 10-25. We also analyse
the consequences of introducing non-universality in the high scale soft
SUSY-breaking mass matrices and find that under these conditions the partial
width can be altered by a large amount.


title: The age of the Galaxy's thick disk

abstract:
  We discuss the age of the stellar disks in the solar neighbourhood. After
reviewing the various methods for age dating we discuss current estimates of
the age of both the thin and the thick disk. We present preliminary results for
kinematically-selected stars that belong to the thin as well as the thick disk.
All of these dwarf and sub-giant stars have been studied spectroscopically and
we have derived both elemental abundances as well as ages for them. A general
conclusion is that in the solar neighbourhood, on average, the thick disk is
older than the thin disk. However, we caution that the exclusion of stars with
effective temperatures around 6500 K might result in a biased view on the full
age distribution for the stars in the thick disk.


title: The Majorana Neutrinoless Double-Beta Decay Experiment

abstract:
  Neutrinoless double-beta decay searches play a major role in determining the
nature of neutrinos, the existence of a lepton violating process, and the
effective Majorana neutrino mass. The Majorana Collaboration proposes to
assemble an array of HPGe detectors to search for neutrinoless double-beta
decay in Ge-76. Our proposed method uses the well-established technique of
searching for neutrinoless double-beta decay in high purity Ge-diode radiation
detectors that play both roles of source and detector. The technique is
augmented with recent improvements in signal processing and detector design,
and advances in controlling intrinsic and external backgrounds. Initially,
Majorana aims to construct a prototype module containing 60 kg of Ge detectors
to demonstrate the potential of a future 1-tonne experiment. The design and
potential reach of this prototype Demonstrator module will be presented. This
paper will also discuss detector optimization and low-background requirements,
such as material purity, background rejection, and identification of rare
backgrounds required to reach the sensitivity goals of the Majorana experiment.


title:
Cataclysmic Variable Primary Effective Temperatures: Constraints on
  Binary Angular Momentum Loss

abstract:
  We review the most decisive currently available measurements of the surface
effective temperatures, Teff, of white dwarf (WD) primaries in cataclysmic
variables (CVs) during accretion quiescence, and use these as a diagnostic for
their time averaged accretion rate, <Mdot>. Using time-dependent calculations
of the WD envelope, we investigate the sensitivity of the quiescent Teff to
long term variations in the accretion rate. We find that the quiescent Teff
provides one of the best available tests of predictions for the angular
momentum loss and resultant mass transfer rates which govern the evolution of
CVs. While gravitational radiation is sufficient to explain the <Mdot> of
strongly magnetic CVs at all Porb, faster angular momentum loss is required by
the temperatures of dwarf nova primaries (non-magnetic systems). This provides
evidence that a normal stellar magnetic field structure near the secondary is
essential for the enhanced braking mechanism to work, supporting the well-known
stellar wind braking hypothesis. The contrast in <Mdot> is most prominent for
orbital periods Porb > 3 hours, above the period gap, but a modest enhancement
is also present at shorter Porb. The averaging time which <Mdot> reflects is as
much as 10^5 years for low-<Mdot> systems and as little as 10^3 years for
high-<Mdot> systems. We discuss the security of conclusions drawn about the CV
population in light of these time scales and our necessarily incomplete sample
of systems. Measurements for non-magnetic systems above the period gap fall
below predictions from traditional stellar wind braking prescriptions, but
above more recent predictions with somewhat weaker angular momentum loss. We
also discuss the apparently high Teff's found in the VY Scl stars. (abridged)


title: Mauna Kea Sky Transparency from CFHT SkyProbe Data

abstract:
  Nighttime sky transparency statistics on Mauna Kea are reported based on data
from the Canada-France-Hawaii Telescope SkyProbe monitor. We focus on the
period beginning with the start of MegaCam wide-field optical imager operations
in 2003, and continuing for almost three years. Skies were clear enough to
observe on 76% of those nights; attenuations were less than 0.2 magnitudes up
to 60% of the time. An empirical model of cloud attenuation and duration is
presented allowing us to further characterize the photometric conditions. This
is a good fit tothe SkyProbe data, and indicates that Mauna Kea skies are truly
photometric (without cloud) an average of 56% of the time, with moderate
seasonal variation. Continuous monitoring of transparency during the night is
necessary to overcome fluctuations in attenuation due to thin cloud.


title: Points in a triangle forcing small triangles

abstract:
  An old theorem of Alexander Soifer's is the following: Given five points in a
triangle of unit area, there must exist some three of them which form a
triangle of area 1/4 or less. It is easy to check that this is not true if
"five" is replaced by "four", but can the theorem be improved in any other way?
We discuss in this article two different extensions of the original result.
  First, we allow the value of "small", 1/4, to vary. In particular, our main
result is to show that given five points in a triangle of unit area, then there
must exist some three of them determining a triangle of area 6/25 or less.
  Second, we put bounds on the minimum number of small triangles determined by
n points in a triangle, and make a conjecture about the asymptotic right answer
as n tends to infinity.


title: Corresponding States of Structural Glass Formers

abstract:
  The variation with respect to temperature T of transport properties of 58
fragile structural glass forming liquids (68 data sets in total) are analyzed
and shown to exhibit a remarkable degree of universality. In particular,
super-Arrhenius behaviors of all super-cooled liquids appear to collapse to one
parabola for which there is no singular behavior at any finite temperature.
This behavior is bounded by an onset temperature To above which liquid
transport has a much weaker temperature dependence. A similar collapse is also
demonstrated, over the smaller available range, for existing numerical
simulation data.


title: Global Slim Accretion Disk Solutions Revisited

abstract:
  We show that there exists a maximal possible accretion rate, beyond which
global slim disk solutions cannot be constructed because in the vertical
direction the gravitational force would be unable to balance the pressure force
to gather the accreted matter. The principle for this restriction is the same
as that for the Eddington luminosity and the corresponding critical accretion
rate, which were derived for spherical accretion by considering the same force
balance in the radial direction. If the assumption of hydrostatic equilibrium
is waived and vertical motion is included, this restriction may become even
more serious as the value of the maximal possible accretion rate becomes
smaller. Previous understanding in the literature that global slim disk
solutions could stand for any large accretion rates is due to the
overestimation of the vertical gravitational force by using an approximate
potential. For accretion flows with large accretion rates at large radii,
outflows seem unavoidable in order for the accretion flow to reduce the
accretion rate and follow a global solution till the central black hole.


title: A new method for producing ultracold molecular ions

abstract:
  We propose a new method for the production of ultracold molecular ions. This
method utilizes sympathetic cooling due to the strong collisions between
appropriately chosen molecular ions and laser-cooled neutral atoms to realize
ultracold, internal ground-state molecular ions. In contrast to other
experiments producing cold molecular ions, our proposed method efficiently
cools both the internal and external molecular ion degrees of freedom. The
availability of an ultracold, absolute ground-state sample of molecular ions
would have broad impact to fields as diverse as quantum chemistry,
astrophysics, and fundamental physics; and may lead to the development of a
robust, scalable quantum computer.


title:
Das asymptotische Verhalten der Grundzustandsenergie des
  Muellerfunktionals fuer schwere Atome

abstract:
  The ground state energy of the Mueller functional of large (neutral) atoms of
atomic number Z agrees with the quantum mechanical ground state energy up to
order o(Z to the 5/3).
  -----
  Die Grundzustandsenergie des Muellerfunktionals von grossen (neutralen)
Atomen der Ordnungszahl Z stimmt mit der quantenmechanischen
Grundzustandsenergie bis zur Ordnung o(Z hoch 5/3) ueberein.

categories: math-ph cond-mat.str-el math.AP math.MP physics.atom-ph


title: Topologies on Quantum Effects

abstract:
  Quantum effects play an important role in quantum measurement theory. The set
of all quantum effects can be organized into an algebraical structure called
effect algebra. In this paper, we study various topologies on the Hilbert space
effect algebra and the projection lattice effect algebra.


title:
Half-metallic ferrimagnet formed by substituting Fe for Mn in
  semiconductor MnTe

abstract:
  A ternary ferrimagnetic half-metal, constructed through substituting 25% Fe
for Mn in zincblende semiconductor MnTe, is predicted in terms of accurate
first-principles calculations. It has a large half-metallic (HM) gap of 0.54eV
and its ferrimagnetic order is very stable against other magnetic fluctuations.
The HM ferrimagnetism is formed because the complete moment compensation in the
antiferromagnetic MnTe is replaced by an uncomplete one in the Fe-substituted
MnTe. This should make a novel approach to new HM materials. The half-metal
could be fabricated because Fe has good affinity with Mn, and useful for
spintronics.


title: Dynamics in two-leg spin ladder with a four-spin cyclic interaction

abstract:
  We study two-leg Heisenberg ladder with four-spin cyclic interaction using
the (dynamical) density-matrix renormalization group method. We demonstrate the
dependence of the low-lying excitations in the spin wave, staggered dimer
order, and scalar-chirality order structure factors on the four-spin cyclic
interaction. We find that the cyclic interaction enhances spin-spin
correlations with wave vector around momentum $(q_x,q_y)=(\frac{\pi}{2},0)$.
Also, the presence of long-range order in the staggered dimer and
scalar-chirality phases is confirmed by a $\delta$-function peak contribution
of the structure factors at energy $\omega=0$.


title: Perfect Matchings via Uniform Sampling in Regular Bipartite Graphs

abstract:
  In this paper we further investigate the well-studied problem of finding a
perfect matching in a regular bipartite graph. The first non-trivial algorithm,
with running time $O(mn)$, dates back to K\"{o}nig's work in 1916 (here $m=nd$
is the number of edges in the graph, $2n$ is the number of vertices, and $d$ is
the degree of each node). The currently most efficient algorithm takes time
$O(m)$, and is due to Cole, Ost, and Schirra. We improve this running time to
$O(\min\{m, \frac{n^{2.5}\ln n}{d}\})$; this minimum can never be larger than
$O(n^{1.75}\sqrt{\ln n})$. We obtain this improvement by proving a uniform
sampling theorem: if we sample each edge in a $d$-regular bipartite graph
independently with a probability $p = O(\frac{n\ln n}{d^2})$ then the resulting
graph has a perfect matching with high probability. The proof involves a
decomposition of the graph into pieces which are guaranteed to have many
perfect matchings but do not have any small cuts. We then establish a
correspondence between potential witnesses to non-existence of a matching
(after sampling) in any piece and cuts of comparable size in that same piece.
Karger's sampling theorem for preserving cuts in a graph can now be adapted to
prove our uniform sampling theorem for preserving perfect matchings. Using the
$O(m\sqrt{n})$ algorithm (due to Hopcroft and Karp) for finding maximum
matchings in bipartite graphs on the sampled graph then yields the stated
running time. We also provide an infinite family of instances to show that our
uniform sampling result is tight up to poly-logarithmic factors (in fact, up to
$\ln^2 n$).


title: Fundamental vibrational mode in a highly inhomogeneous star

abstract:
  The eigenfrequency problem of fundamental vibrational mode in a highly
inhomogeneous star, modeled by self-gravitating mass of viscous liquid with
singular density at the center, is considered in juxtaposition with that for
Kelvin fundamental mode in the liquid star model with uniform density.
Particular attention is given to the difference between spectral equations for
the frequency and lifetime of f-mode in the singular and homogeneous star
models. The newly obtained results are discussed in the context of theoretical
asteroseismology of pre-white dwarf stars and stellar cocoons -- spherical
gas-dust clouds with dense star-forming core at the center.


title:
Universality of shear-banding instability and crystallization in sheared
  granular fluid

abstract:
  The linear stability analysis of an uniform shear flow of granular materials
is revisited using several cases of a Navier-Stokes'-level constitutive model
in which we incorporate the global equation of states for pressure and thermal
conductivity (which are accurate up-to the maximum packing density $\nu_{m}$)
and the shear viscosity is allowed to diverge at a density $\nu_\mu$ ($<
\nu_{m}$), with all other transport coefficients diverging at $\nu_{m}$. It is
shown that the emergence of shear-banding instabilities (for perturbations
having no variation along the streamwise direction), that lead to shear-band
formation along the gradient direction, depends crucially on the choice of the
constitutive model. In the framework of a dense constitutive model that
incorporates only collisional transport mechanism, it is shown that an accurate
global equation of state for pressure or a viscosity divergence at a lower
density or a stronger viscosity divergence (with other transport coefficients
being given by respective Enskog values that diverge at $\nu_m$) can induce
shear-banding instabilities, even though the original dense Enskog model is
stable to such shear-banding instabilities. For any constitutive model, the
onset of this shear-banding instability is tied to a {\it universal} criterion
in terms of constitutive relations for viscosity and pressure, and the sheared
granular flow evolves toward a state of lower "dynamic" friction, leading to
the shear-induced band formation, as it cannot sustain increasing dynamic
friction with increasing density to stay in the homogeneous state. A similar
criterion of a lower viscosity or a lower viscous-dissipation is responsible
for the shear-banding state in many complex fluids.


title: Quantum Kolmogorov Complexity and Quantum Key Distribution

abstract:
  We discuss the Bennett-Brassard 1984 (BB84) quantum key distribution protocol
in the light of quantum algorithmic information. While Shannon's information
theory needs a probability to define a notion of information, algorithmic
information theory does not need it and can assign a notion of information to
an individual object. The program length necessary to describe an object,
Kolmogorov complexity, plays the most fundamental role in the theory. In the
context of algorithmic information theory, we formulate a security criterion
for the quantum key distribution by using the quantum Kolmogorov complexity
that was recently defined by Vit\'anyi. We show that a simple BB84 protocol
indeed distribute a binary sequence between Alice and Bob that looks almost
random for Eve with a probability exponentially close to 1.


title: A family of super Schrodinger invariant Chern-Simons matter systems

abstract:
  We investigate non-relativistic limits of the N=3 Chern-Simons matter system
in 1+2 dimensions. The relativistic theory can generate several inequivalent
super Schodinger invariant theories, depending on the degrees of freedom we
choose to retain in the non-relativistic limit. The maximally supersymmetric
Schrodinger invariant theory is obtained by keeping all particle degrees of
freedom. The other descendants, where particles and anti-particles coexist, are
also Schrodinger invariant but preserve less supersymmetries. Thus, we have a
family of super Schrodinger invariant field theories produced from the parent
relativistic theory.


title: Perturbation Theory of High-Tc Superconductivity in Iron Pnictides

abstract:
  The high-transition-temperature (high-Tc) superconductivity discovered
recently in iron pnictides is analyzed within a perturbation theory.
Specifically, the probable pairing symmetry, the doping dependence of the
transition temperature and the pairing mechanism are studied by solving the
Eliashberg equation for multi-band (2- and 5-band) Hubbard models with
realistic electronic structures. The effective pairing interaction is expanded
perturbatively in the on-site Coulomb integrals up to third order. Our
perturbative weak-coupling approach shows that sufficiently large eigenvalues
of the Eliashberg equation are obtained to explain the actual high transition
temperatures by taking realistic on-site Coulomb integrals in the 5-band model.
Thus, unconventional (non-phonon-mediated) superconductivity is highly likely
to be realized. The superconducting order parameter does not change its sign on
the Fermi surfaces, but it does change between the electron and hole Fermi
surfaces. Consequently, the probable pairing symmetry is always "a nodeless
extended s-wave symmetry (more specifically, an s_{+-}-wave symmetry)" over the
whole parameter region that we investigated. It is suggested that the 2-band
model is insufficient to explain the high values of Tc.


title:
Determination of the phase diagram of the electron doped superconductor
  Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$

abstract:
  Systematic measurements of the resistivity, heat capacity, susceptibility and
Hall coefficient are presented for single crystal samples of the electron-doped
superconductor Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$. These data delineate an $x-T$
phase diagram in which the single magnetic/structural phase transition that is
observed for undoped BaFe$_2$As$_2$ at 134 K apparently splits into two
distinct phase transitions, both of which are rapidly suppressed with
increasing Co concentration. Superconductivity emerges for Co concentrations
above $x \sim 0.025$, and appears to coexist with the broken symmetry state for
an appreciable range of doping, up to $x \sim 0.06$. The optimal
superconducting transition temperature appears to coincide with the Co
concentration at which the magnetic/structural phase transitions are totally
suppressed, at least within the resolution provided by the finite step size
between crystals prepared with different doping levels. Superconductivity is
observed for a further range of Co concentrations, before being completely
suppressed for $x \sim 0.018$ and above. The form of this $x-T$ phase diagram
is suggestive of an association between superconductivity and a quantum
critical point arising from suppression of the magnetic and/or structural phase
transitions.


title:
A model of underground ridership during the severe outbreaks of the SARS
  epidemic in a modern city

abstract:
  The outbreaks of the severe acute respiratory syndrome (SARS) epidemic in
2003 resulted in unprecedented impacts on people's daily life. One of the most
significant impacts to people is the risk of contacting SARS while engaging
daily routine activity. In this work we use data from daily underground
ridership in Taipei and daily reported SARS cases in Taiwan to model the
dynamics of the public underground usage during the wax and wane of the SARS
period. We found that for each reported SARS case there is an immediate loss of
about 1200 underground ridership. These loss rates propagate to the following
days with an e-folding decay time of about 28 days, reflecting the public
perception on the risk of contacting SARS disease when travelling with the
underground system. About 50% of daily ridership was lost during the peak of
the 2003 SARS period, compared with the loss of 80% daily ridership during the
closure of the underground system after Typhoon Nari, the loss of 50-70%
ridership due to the closure of the governmental offices and schools during
typhoon periods, and the loss of 60% daily ridership during Chinese New Year
holidays.


title: Assessing the efficiency of first-principles basin-hopping sampling

abstract:
  We present a systematic performance analysis of first-principles
basin-hopping (BH) runs, with the target to identify all low-energy isomers of
small Si and Cu clusters described within density-functional theory. As
representative and widely employed move classes we focus on single-particle and
collective moves, in which one or all atoms in the cluster at once are
displaced in a random direction by some prescribed move distance, respectively.
The analysis provides detailed insights into the bottlenecks and governing
factors for the sampling efficiency, as well as simple rules-of-thumb for
near-optimum move settings, that are intriguingly independent of the distinctly
different chemistry of Si and Cu. At corresponding settings, the observed
performance of the BH algorithm employing two simple, general-purpose move
classes is already very good, and for the small systems studied essentially
limited by frequent revisits to a few dominant isomers.


title:
gamma-ray emission from LS I +61 303: The impact of basic system
  uncertainties

abstract:
  LS I +61 303 has been recently detected as a periodic gamma-ray source by the
Major Atmospheric Imaging Cerenkov (MAGIC) telescope. A distinctive orbital
correlation of the $\gamma$-ray emission was found. This work shows that the
range of uncertainties yet at hand in the orbital elements of the binary system
LSI as well as in the possible assumptions on the stellar wind of the optical
companion play a non-negligible role in the computation of opacities to high
energy processes leading to $\gamma$-ray predictions. The geometry influence on
the propagation and escape of $\gamma$-ray photons is explored. With this study
at hand, we analyse the results of a pulsar wind zone model for the production
of gamma-rays and compare it with recent MAGIC observations.


title: Warm gas accretion onto the Galaxy

abstract:
  We present evidence that the accretion of warm gas onto the Galaxy today is
at least as important as cold gas accretion. For more than a decade, the source
of the bright H-alpha emission (up to 750 mR) along the Magellanic Stream has
remained a mystery. We present a hydrodynamical model that explains the known
properties of the H-alpha emission and provides new insights on the lifetime of
the Stream clouds. The upstream clouds are gradually disrupted due to their
interaction with the hot halo gas. The clouds that follow plough into gas
ablated from the upstream clouds, leading to shock ionisation at the leading
edges of the downstream clouds. Since the following clouds also experience
ablation, and weaker H-alpha (100-200 mR) is quite extensive, a disruptive
cascade must be operating along much of the Stream. In order to light up much
of the Stream as observed, it must have a small angle of attack (~20 deg) to
the halo, and this may already find support in new HI observations. Another
prediction is that the Balmer ratio will be substantially enhanced due to the
slow shock. We find that the clouds are evolving on timescales of 100-200 Myr,
such that the Stream must be replenished by the Magellanic Clouds at a fairly
constant rate (>0.1 Msun/yr). The ablated material falls onto the Galaxy as a
warm drizzle; diffuse ionized gas at 10^4 K is an important constituent of
galactic accretion. We consider the stability of HI clouds falling towards the
Galactic disk and show that most of these must break down into smaller
fragments that become partially ionized. The Galactic halo is expected to have
huge numbers of smaller neutral and ionized fragments. When the ionized
component is accounted for, the rate of gas accretion is ~0.4 Msun/yr, roughly
twice the rate deduced from HI observations alone.


title: Causality violating geodesics in Bonnor's rotating dust metric

abstract:
  We exhibit timelike geodesic paths for a metric, introduced by Bonnor [11]
and considered also by Steadman [13], and show that coordinate time runs
backward along a portion of these geodesics.


title:
A Family of Runge-Kutta Methods with Zero Phase-Lag and Derivatives for
  the Numerical Solution of the Schr\"odinger Equation and Related Problems

abstract:
  We construct a family of two new optimized explicit Runge-Kutta methods with
zero phase-lag and derivatives for the numerical solution of the
time-independent radial Schr\"odinger equation and related ordinary
differential equations with oscillating solutions. The numerical results show
the superiority of the new technique of nullifying both the phase-lag and its
derivatives.


title:
Two Optimized Symmetric Eight-Step Implicit Methods for Initial-Value
  Problems with Oscillating Solutions

abstract:
  In this paper we present two optimized eight-step symmetric implicit methods
with phase-lag order ten and infinite (phase-fitted). The methods are
constructed to solve numerically the radial time-independent Schr\"odinger
equation with the use of the Woods-Saxon potential. They can also be used to
integrate related IVPs with oscillating solutions such as orbital problems. We
compare the two new methods to some recently constructed optimized methods from
the literature. We measure the efficiency of the methods and conclude that the
new method with infinite order of phase-lag is the most efficient of all the
compared methods and for all the problems solved.


title: Frame dragging anomalies for rotating bodies

abstract:
  Examples of axially symmetric solutions to Einstein's field equations are
given that exhibit anomalous "negative frame dragging" in the sense that zero
angular momentum test particles acquire angular velocities in the opposite
direction of rotation from the source of the metric.


title: Interaction-Flip Identities in Spin Glasses

abstract:
  We study the properties of fluctuation for the free energies and internal
energies of two spin glass systems that differ for having some set of
interactions flipped. We show that their difference has a variance that grows
like the volume of the flipped region. Using a new interpolation method, which
extends to the entire circle the standard interpolation technique, we show by
integration by parts that the bound imply new overlap identities for the
equilibrium state. As a side result the case of the non-interacting random
field is analyzed and the triviality of its overlap distribution proved.


title:
A New Methodology for the Development of Numerical Methods for the
  Numerical Solution of the Schr\"odinger Equation

abstract:
  In the present paper we introduce a new methodology for the construction of
numerical methods for the approximate solution of the one-dimensional
Schr\"odinger equation. The new methodology is based on the requirement of
vanishing the phase-lag and its derivatives. The efficiency of the new
methodology is proved via error analysis and numerical applications.


title: A simple criterion for nonrotating reference frames

abstract:
  We prove a theorem that gives an easily verifiable necessary and sufficient
condition for a reference frame with fixed spacelike coordinates to be
nonrotating in the sense of Walker. Applications are discussed.


title: Commutative association schemes

abstract:
  Association schemes were originally introduced by Bose and his co-workers in
the design of statistical experiments. Since that point of inception, the
concept has proved useful in the study of group actions, in algebraic graph
theory, in algebraic coding theory, and in areas as far afield as knot theory
and numerical integration. This branch of the theory, viewed in this collection
of surveys as the "commutative case," has seen significant activity in the last
few decades. The goal of the present survey is to discuss the most important
new developments in several directions, including Gelfand pairs, cometric
association schemes, Delsarte Theory, spin models and the semidefinite
programming technique. The narrative follows a thread through this list of
topics, this being the contrast between combinatorial symmetry and
group-theoretic symmetry, culminating in Schrijver's SDP bound for binary codes
(based on group actions) and its connection to the Terwilliger algebra (based
on combinatorial symmetry). We propose this new role of the Terwilliger algebra
in Delsarte Theory as a central topic for future work.


title:
High Order Multistep Methods with Improved Phase-Lag Characteristics for
  the Integration of the Schr\"odinger Equation

abstract:
  In this work we introduce a new family of twelve-step linear multistep
methods for the integration of the Schr\"odinger equation. The new methods are
constructed by adopting a new methodology which improves the phase lag
characteristics by vanishing both the phase lag function and its first
derivatives at a specific frequency. This results in decreasing the sensitivity
of the integration method on the estimated frequency of the problem. The
efficiency of the new family of methods is proved via error analysis and
numerical applications.


title:
On certain diophantine equations related to triangular and tetrahedral
  numbers

abstract:
  In this paper we give solutions of certain diophantine equations related to
triangular and tetrahedral numbers and propose several problems connected with
these numbers.
  The material of this paper was presented in part at the 11th International
Workshop for Young Mathematicians - NUMBER THEORY, Krak\'{o}w, 14th-20th
september 2008.


title:
High Order Phase Fitted Multistep Integrators for the Schr\"odinger
  Equation with Improved Frequency Tolerance

abstract:
  In this work we introduce a new family of 14-steps linear multistep methods
for the integration of the Schr\"odinger equation. The new methods are phase
fitted but they are designed in order to improve the frequency tolerance. This
is achieved by eliminating the first derivatives of the phase lag function at
the fitted frequency forcing the phase lag function to be '\textit{flat}'
enough in the neighbor of the fitted frequency. The efficiency of the new
family of methods is proved via error analysis and numerical applications.


title: Negative-index media for matter-wave optics

abstract:
  We consider the extension of optical meta-materials to matter waves. We show
that the generic property of pulsed comoving magnetic fields allows us to
fashion the wave-number dependence of the atomic phase shift. It can be used to
produce a transient negative group velocity of an atomic wave packet, which
results into a negative refraction of the matter wave. Application to slow
metastable argon atoms Ar*(3P2) shows that the device is able to operate either
as an efficient beam splitter or an atomic meta-lens. Implications of
"meta-media" in atom optics are considered.


title:
Zero Dispersion and Zero Dissipation Implicit Runge-Kutta Methods for
  the Numerical Solution of Oscillating IVPs

abstract:
  In this paper we present two new methods based on an implicit Runge-Kutta
method Gauss which is of algebraic order fourth and has two stages: the first
one has zero dispersion and the second one has zero dispersion and zero
dissipation. The efficiency of these methods is measured while integrating the
radial Schr\"odinger equation and other well known initial value problems.


title:
A Phase-Fitted Runge-Kutta-Nystr\"om method for the Numerical Solution
  of Initial Value Problems with Oscillating Solutions

abstract:
  A new Runge-Kutta-Nystr\"om method, with phase-lag of order infinity, for the
integration of second-order periodic initial-value problems is developed in
this paper. The new method is based on the Dormand and Prince
Runge-Kutta-Nystr\"om method of algebraic order four\cite{pa}. Numerical
illustrations indicate that the new method is much more efficient than the
classical one.


title: Counting arithmetic lattices and surfaces

abstract:
  We give estimates on the number $AL_H(x)$ of arithmetic lattices $\Gamma$ of
covolume at most $x$ in a simple Lie group $H$. In particular, we obtain a
first concrete estimate on the number of arithmetic 3-manifolds of volume at
most $x$. Our main result is for the classical case $H=PSL(2,R)$ where we
compute the limit of $\log AL_H(x) / x\log x$ when $x\to\infty$. The proofs use
several different techniques: geometric (bounding the number of generators of
$\Gamma$ as a function of its covolume), number theoretic (bounding the number
of maximal such $\Gamma$) and sharp estimates on the character values of the
symmetric groups (to bound the subgroup growth of $\Gamma$).


title: Two-speed phase dynamics in Si(111) (7x7)-(1x1) phase transition

abstract:
  We propose a natural two-speed model for the phase dynamics of Si(111)
7$\times$7 phase transition to high temperature unreconstructed phase. We
formulate the phase dynamics by using phase-field method and adaptive mesh
refinement. Our simulated results show that a 7$\times$7 island decays with its
shape kept unchanged, and its area decay rate is shown to be a constant
increasing with its initial area. LEEM experiments concerned are explained,
which confirms that the dimer chains and corner holes are broken first in the
transition, and then the stacking fault is remedied slowly. This phase-field
method is a reliable approach to phase dynamics of surface phase transitions.


title: Observation and modelling of dusty, low gravity L, and M dwarfs

abstract:
  Observational facilities allow now the detection of optical and IR spectra of
young M- and L-dwarfs. This enables empirical comparisons with old M- and L-
dwarfs, and detailed studies in comparison with synthetic spectra. While
classical stellar atmosphere physics seems perfectly appropriate for old
M-dwarfs, more physical and chemical processes, cloud formation in particular,
needs to be modelled in the substellar regime to allow a detailed spectral
interpretation.
  Not much is known so far about the details of the inset of cloud formation at
the spectral transition region between M and L dwarfs. Furthermore there is
observational evidence for diversity in the dust properties of objects having
the same spectral type. Do we understand these differences? The question is
also how young M- and L-dwarfs need to be classified, which stellar parameter
do they have and whether degenerations in the stellar parameter space due to
the changing atmosphere physics are present, like in the L-T transition region.
  The Splinter was driven by these questions which we will use to encourage
interactions between observation and theory. Given the recent advances, both in
observations and spectral modelling, an intensive discussion between observers
and theoreticians will create new synergies in our field.


title: Activity and rotation of low mass stars in young open clusters

abstract:
  We present first results from a multi-object spectroscopy campaign in IC2602,
the Hyades, the Pleiades, and the Coma cluster using VLT/FLAMES. We analysed
the data for radial velocity, rotational velocity, and H-alpha activity. Here,
we highlight three aspects of this study in the context of rotational braking
and the rotation-activity relationship among low mass stars. Finally we discuss
the cluster membership of sources in IC2602.


title: A search for wide brown dwarf companions to stars within 10pc

abstract:
  We present the first results of a large imaging survey to identify wide brown
dwarf companions to stars within 10 pc. We have performed a deep (H-band limit
~ 19.0 mag), wide field (up to 16x16 arcmin) astrometric imaging campaign in
two epochs around more than 230 nearby stars.
  Preliminary results show that the wide low-mass companion fraction is far
lower than expected, indicating that interactions with the galactic disk may
have removed the weakly bound wide companions around old stars.


title:
The Number of Supertraces on the Superalgebra of Observables of Rational
  Calogero Model based on the Root System

abstract:
  In the Coxeter group W(R) generated by the root system R, let Q(R) be the
number of conjugacy classes having no eigenvalue -1. The superalgebra of
observables of the rational Calogero model based on the root system R possesses
Q(R) supertraces. The numbers Q(R) are determined for all irreducible root
systems (hence for all root systems).


title: Mechanisms of exclusive meson production at high energies

abstract:
  I discuss mechanisms of exclusive production of mesons at high energies. Some
illustrative examples for the FNAL Tevatron and CERN LHC as well as for lower
energies are shown.


title: Plykin-like attractor in non-autonomous coupled oscillators

abstract:
  A system of two coupled non-autonomous oscillators is considered. Dynamics of
complex amplitudes is governed by differential equations with periodic
piecewise continuous dependence of the coefficients on time. The Poincar\'{e}
map is derived explicitly. With exclusion of the overall phase, on which the
evolution of other variables does not depend, the Poincar\'{e} map is reduced
to 3D mapping. It possesses an attractor of Plykin type located on an invariant
sphere. Computer verification of the cone criterion confirms the hyperbolic
nature of the attractor in the 3D map. Some results of numerical studies of the
dynamics for the coupled oscillators are presented, including the attractor
portraits, Lyapunov exponents, and the power spectral density.


title:
Measurements of Charge Transfer Inefficiency in a CCD with High-Speed
  Column Parallel Readout

abstract:
  Charge Coupled Devices (CCDs) have been successfully used in several high
energy physics experiments over the past two decades. Their high spatial
resolution and thin sensitive layers make them an excellent tool for studying
short-lived particles. The Linear Collider Flavour Identification (LCFI)
collaboration is developing Column-Parallel CCDs (CPCCDs) for the vertex
detector of a future Linear Collider. The CPCCDs can be read out many times
faster than standard CCDs, significantly increasing their operating speed. A
test stand for measuring the charge transfer inefficiency (CTI) of a prototype
CPCCD has been set up. Studies of the CTI have been performed at a range of
readout frequencies and operating temperatures.


title: On the Dynamics of Inclined Neptune's Trojans

abstract:
  The dynamics of artificial asteroids on the Trojan-like orbits around Neptune
is investigated in this paper. We describe the dependence of the orbital
stability on the initial semimajor axis a and inclination i by constructing a
dynamical map on the (a,i)-plane. Rich details are revealed in the dynamical
map, especially a unstable gap at i=45 deg is determined and the mechanism
triggering chaos in this region is figured out. Our investigation can be used
to guide the observations.


title:
Soft Hubbard gaps in disordered itinerant models with short-range
  interaction

abstract:
  We study the Anderson-Hubbard model in the Hartree-Fock approximation and the
exact diagonalization under the coexistence of short-range interaction and
diagonal disorder. We show that there exist unconventional soft gaps, where the
single-particle (SP) density of states (DOS) $A$ follows a scaling in energy
$E$ as $A(E)\propto \exp[-(-\gamma\log |E-E_F|)^d]$ irrespective of electron
filling and long-range order. Here, $d$ is the spatial dimension, $E_F$ the
Fermi energy and $\gamma$ a non-universal constant. We propose a multi-valley
energy landscape as their origin. Possible experiments to verify the present
theory are proposed.


title: Electromagnetic interactions at RHIC and LHC

abstract:
  At LHC energies the Lorentz factor will be 3400 for the Pb + Pb collisions
and the electromagnetic interactions will play important roles. Cross sections
for the electromagnetic particle productions are very large and can not be
ignored for the lifetimes of the beams and background. In this article, we are
going to study some of the electromagnetic processes at RHIC and LHC and show
the cross section calculations of the electron-positron pair production with
the giant dipole resonance of the ions.


title:
Heat capacity measurements on FeAs-based compounds: a thermodynamic
  probe of electronic and magnetic states

abstract:
  We report heat capacity measurements of the pnictide materials
SmFeAsO$_{1-x}$F$_x$, NdFeAsO, LaFeAsO$_{1-x}$F$_x$ and LiFeAs. For
SmFeAsO$_{1-x}$F$_x$, with x close to 0.1, we use 3 He measurements to
demonstrate a transfer of entropy from the peak at TN to a previously
unidentified ~2 K feature which grows with increasing doping. Our results on
the Sm samples are compared with a similarly doped La sample to elucidate the
crystal field levels of the Sm3+ ion at 0, 23, and 56 meV which lead to a
Schottky-like anomaly, and also show that there is a significant increase in
the Sommerfeld coefficient $\gamma$ when La is replaced by Sm or Nd. The
lattice contribution to the heat capacity of the superconducting oxypnictides
is found to vary negligibly with chemical substitution. We also present a heat
capacity measurement of LiFeAs showing the feature at Tc, which is
significantly rounded and much smaller than the BCS value.


title: Synergy of multifrequency studies from observations of NGC6334I

abstract:
  We combine multifrequency observations from the millimeter to near infrared
wavelengths that demonstrate the spatial distributions of H2, CO, and NH3
emission, which are all manifestations of various shocks driven by outflows of
deeply embedded sources in NGC6334I. In addition to the well-known
northeast-southwest outflow we detect at least one more outflow in the region
by combining observations from APEX, ATCA, SMA, Spitzer and VLT/ISAAC.
Potential driving sources will be discussed. NGC6334I exhibits several signs of
active star formation and will be a major target for future observatories such
as Herschel and ALMA.