title: Bose-Einstein Condensation in Magnetic Insulators

abstract:
  The elementary excitations in antiferromagnets are magnons, quasiparticles
with integer spin and Bose statistics. In an experiment their density is
controlled efficiently by an applied magnetic field and can be made finite to
cause the formation of a Bose-Einstein condensate (BEC). Studies of magnon
condensation in a growing number of magnetic materials provide a unique window
into an exciting world of quantum phase transitions (QPT) and exotic quantum
states.


title: Multigraded regularity and the Koszul property

abstract:
  We give a criterion for the section ring of an ample line bundle to be Koszul
in terms of multigraded regularity. We discuss an application to polytopal
semigroup rings.


title: Macroscopic Resonant Tunneling through Andreev Interferometers

abstract:
  We investigate the conductance through and the spectrum of ballistic chaotic
quantum dots attached to two s-wave superconductors, as a function of the phase
difference $\phi$ between the two order parameters. A combination of analytical
techniques -- random matrix theory, Nazarov's circuit theory and the
trajectory-based semiclassical theory -- allows us to explore the
quantum-to-classical crossover in detail. When the superconductors are not
phase-biased, $\phi=0$, we recover known results that the spectrum of the
quantum dot exhibits an excitation gap, while the conductance across two normal
leads carrying $N_{\rm N}$ channels and connected to the dot via tunnel
contacts of transparency $\Gamma_{\rm N}$ is $\propto \Gamma_{\rm N}^2 N_{\rm
N}$. In contrast, when $\phi=\pi$, the excitation gap closes and the
conductance becomes $G \propto \Gamma_{\rm N} N_{\rm N}$ in the universal
regime. For $\Gamma_{\rm N} \ll 1$, we observe an order-of-magnitude
enhancement of the conductance towards $G \propto N_{\rm N}$ in the
short-wavelength limit. We relate this enhancement to resonant tunneling
through a macroscopic number of levels close to the Fermi energy. Our
predictions are corroborated by numerical simulations.


title: Large Deviations for Random Trees

abstract:
  We consider large random trees under Gibbs distributions and prove a Large
Deviation Principle (LDP) for the distribution of degrees of vertices of the
tree. The LDP rate function is given explicitly. An immediate consequence is a
Law of Large Numbers for the distribution of vertex degrees in a large random
tree. Our motivation for this study comes from the analysis of RNA secondary
structures.


title: On free profinite subgroups of free profinite monoids

abstract:
  We answer a question of Margolis from 1997 by establishing that the maximal
subgroup of the minimal ideal of a finitely generated free profinite monoid is
a free profinite group. More generally if $\mathbf H$ is variety of finite
groups closed under extension and containing $\mathbb Z/p\mathbb Z$ for
infinitely may primes $p$, the corresponding result holds for free
pro-$\bar{\mathbf H}$ monoids.


title: Human-Machine Symbiosis, 50 Years On

abstract:
  Licklider advocated in 1960 the construction of computers capable of working
symbiotically with humans to address problems not easily addressed by humans
working alone. Since that time, many of the advances that he envisioned have
been achieved, yet the time spent by human problem solvers in mundane
activities remains large. I propose here four areas in which improved tools can
further advance the goal of enhancing human intellect: services, provenance,
knowledge communities, and automation of problem-solving protocols.


title: Spin-orbit coupled Bose-Einstein condensates

abstract:
  We consider a many-body system of pseudo-spin-1/2 bosons with spin-orbit
interactions, which couple the momentum and the internal pseudo-spin degree of
freedom created by spatially varying laser fields. The corresponding single-
particle spectrum is generally anisotropic and contains two degenerate minima
at finite momenta. At low temperatures, the many-body system condenses into
these minima generating a new type of entangled Bose-Einstein condensate. We
show that in the presence of weak density-density interactions the many-body
ground state is characterized by a twofold degeneracy. The corresponding
many-body wave function describes a condensate of ``left-'' and
``right-moving'' bosons. By fine-tuning the parameters of the laser field, one
can obtain a bosonic version of the spin-orbit coupled Rashba model. In this
symmetric case, the degeneracy of the ground state is very large, which may
lead to phases with nontrivial topological properties. We argue that the
predicted new type of Bose-Einstein condensates can be observed experimentally
via time-of-flight imaging, which will show characteristic multipeak structures
in momentum distribution.


title: On the sound of snapping shrimp

abstract:
  Fluid dynamics video: Snapping shrimp produce a snapping sound by an
extremely rapid closure of their snapper claw. Our high speed imaging of the
claw closure has revealed that the sound is generated by the collapse of a
cavitation bubble formed in a fast flowing water jet forced out from the claws
during claw closure. The produced sound originates from the cavitation collapse
of the bubble. At collapse a short flash of light is emitted, just as in single
bubble sonoluminescence. A model based on the Rayleigh-Plesset equation can
quantitatively account for the visual and acoustical observations.


title:
Subspace correction methods for total variation and
  $\ell_1-$minimization

abstract:
  This paper is concerned with the numerical minimization of energy functionals
in Hilbert spaces involving convex constraints coinciding with a semi-norm for
a subspace. The optimization is realized by alternating minimizations of the
functional on a sequence of orthogonal subspaces. On each subspace an iterative
proximity-map algorithm is implemented via \emph{oblique thresholding}, which
is the main new tool introduced in this work. We provide convergence conditions
for the algorithm in order to compute minimizers of the target energy.
Analogous results are derived for a parallel variant of the algorithm.
Applications are presented in domain decomposition methods for singular
elliptic PDE's arising in total variation minimization and in accelerated
sparse recovery algorithms based on $\ell_1$-minimization. We include numerical
examples which show efficient solutions to classical problems in signal and
image processing.


title: Poisson-Lie T-Duality and non trivial monodromies

abstract:
  We describe a general framework for studying duality between different phase
spaces which share the same symmetry group $\mathrm{H}$. Solutions
corresponding to collective dynamics become dual in the sense that they are
generated by the same curve in $\mathrm{H}$. Explicit examples of phase spaces
which are dual with respect to a common non trivial coadjoint orbit
$\mathcal{O}_{c,0}(\mathbf{\alpha},1) \subset\mathfrak{h}^{\ast}$ are
constructed on the cotangent bundles of the factors of a double Lie group
$\mathrm{H}=\mathrm{N}\Join\mathrm{N}^{\ast}$. In the case $\mathrm{H}=LD$, the
loop group of a Drinfeld double Lie group $D$, a hamiltonian description of
Poisson-Lie T-duality for non trivial monodromies and its relation with non
trivial coadjoint orbits is obtained.


abstract:
  The initial value problem of scalar-tensor theories of gravity (STT) is
analyzed in the physical (Jordan) frame using a 3+1 decomposition of spacetime.
A first order strongly hyperbolic system is obtained for which the well
posedness of the Cauchy problem can be established. We provide two simple
applications of the 3+1 system of equations: one for static and spherically
symmetric spacetimes which allows the construction of unstable initial data
(compact objects) for which a further black hole formation and scalar
gravitational wave emission can be analyzed, and another application is for
homogeneous and isotropic spacetimes that permits to study the dynamics of the
Universe in the framework of STT.


title: When Worlds Collide

abstract:
  We analyze the cosmological signatures visible to an observer in a Coleman-de
Luccia bubble when another such bubble collides with it. We use a gluing
procedure to generalize the results of Freivogel, Horowitz, and Shenker to the
case of a general cosmological constant in each bubble and study the resulting
spacetimes. The collision breaks the isotropy and homogeneity of the bubble
universe and provides a cosmological "axis of evil" which can affect the cosmic
microwave background in several unique and potentially detectable ways. Unlike
more conventional perturbations to the inflationary initial state, these
signatures can survive even relatively long periods of inflation. In addition,
we find that for a given collision the observers in the bubble with smaller
cosmological constant are safest from collisions with domain walls, possibly
providing another anthropic selection principle for small positive vacuum
energy.


title:
The Earth System Grid: Supporting the Next Generation of Climate
  Modeling Research

abstract:
  Understanding the earth's climate system and how it might be changing is a
preeminent scientific challenge. Global climate models are used to simulate
past, present, and future climates, and experiments are executed continuously
on an array of distributed supercomputers. The resulting data archive, spread
over several sites, currently contains upwards of 100 TB of simulation data and
is growing rapidly. Looking toward mid-decade and beyond, we must anticipate
and prepare for distributed climate research data holdings of many petabytes.
The Earth System Grid (ESG) is a collaborative interdisciplinary project aimed
at addressing the challenge of enabling management, discovery, access, and
analysis of these critically important datasets in a distributed and
heterogeneous computational environment. The problem is fundamentally a Grid
problem. Building upon the Globus toolkit and a variety of other technologies,
ESG is developing an environment that addresses authentication, authorization
for data access, large-scale data transport and management, services and
abstractions for high-performance remote data access, mechanisms for scalable
data replication, cataloging with rich semantic and syntactic information, data
discovery, distributed monitoring, and Web-based portals for using the system.


title:
Two-dimensional correlation spectroscopy of two-exciton resonances in
  semiconductor quantum wells

abstract:
  We propose a three-pulse coherent ultrafast optical technique that is
particularly sensitive to two-exciton correlations. Two Liouville-space
pathways for the density matrix contribute to this signal which reveals double
quantum coherences when displayed as a two-dimensional correlation plot.
Two-exciton couplings spread the cross peaks along both axes, creating a
characteristic highly resolved pattern. This level of detail is not available
from conventional one-dimensional four-wave mixing or other two-dimensional
correlation spectroscopy signals such as the photo echo, in which two-exciton
couplings show up along a single axis and are highly congested.


title: Phenomenology of Infrared Smooth Warped Extra Dimensions

abstract:
  We study the effect of the infrared (IR) geometry on the phenomenology of
warped extra dimensions with gauge and fermion fields in the bulk. We focus in
particular on a "mass gap" metric which is AdS in the ultraviolet, but
asymptotes to flat space in the IR, breaking conformal symmetry. These metrics
can be dialed to approximate well the geometries arising in certain classes of
warped string compactifications. We find, similar to our earlier results on the
Kaluza-Klein (KK) graviton, that these metrics give rise to phenomenologically
significant shifts in the separation of KK gauge modes in the mass spectrum (up
to factors of ~2) and their couplings to IR localized fields (up to factors of
~5-10 increase). We find that, despite shifts in the spectra, the constraint
m_KK > 3 TeV from S remains robust in the class of 5-d mass gap metrics, and
that the change to T is not significant enough to remove the need for custodial
symmetry.


title: The de Finetti theorem for test spaces

abstract:
  We prove a de Finetti theorem for exchangeable sequences of states on test
spaces, where a test space is a generalization of the sample space of classical
probability theory and the Hilbert space of quantum theory. The standard
classical and quantum de Finetti theorems are obtained as special cases. By
working in a test space framework, the common features that are responsible for
the existence of these theorems are elucidated. In addition, the test space
framework is general enough to imply a de Finetti theorem for classical
processes. We conclude by discussing the ways in which our assumptions may
fail, leading to probabilistic models that do not have a de Finetti theorem.


title: Dalitz Plot Analyses at CLEO-c

abstract:
  We present several recent analyses of Dalitz plots from the CLEO-c
experiment, including published and preliminary analyses of D+ to pi- pi+ pi+,
D+ to K- pi+ pi+, and D0 to K0_{S,L} pi+ pi- decays. More information on these
analyses can be found in References [1-3]. New preliminary analyses we present
include a search for CP asymmetry in D+ to K+ K- pi+ decays and a Dalitz plot
analysis of D0 to K0_{S} pi0 pi0. We report on a search for the CP asymmetry in
the singly Cabibbo-suppressed decay D+ to K+ K- pi+ using a data sample of 572
pb^{-1} accumulated with the CLEO-c detector and taken at the e+ e- to
psi(3770) resonance. We have searched for CP asymmetries using a Dalitz plot
based analysis that determines the amplitudes and relative phases of the
intermediate states. We also use a 281 pb^{-1} CLEO-c data sample taken at the
e+ e- to psi(3770) resonance to study the D0 to K0_S pi0 pi0 Dalitz plot. Our
nominal fit includes the K0_S, K*(892), f_0(980), f_0(1370), and K*(1680)
resonances.


title:
An Interaction of a Magellanic Leading Arm High Velocity Cloud with the
  Milky Way Disk

abstract:
  The Leading Arm of the Magellanic System is a tidally formed HI feature
extending $\sim 60\arcdeg$ from the Magellanic Clouds ahead of their direction
of motion. Using atomic hydrogen (HI) data from the Galactic All Sky-Survey
(GASS), supplemented with data from the Australia Telescope Compact Array, we
have found evidence for an interaction between a cloud in the Leading Arm and
the Galactic disk where the Leading Arm crosses the Galactic plane. The
interaction occurs at velocities permitted by Galactic rotation, which allows
us to derive a kinematic distance to the cloud of 21 kpc, suggesting that the
Leading Arm crosses the Galactic Plane at a Galactic radius of $R\approx 17$
kpc.


title:
Solar system and equivalence principle constraints on f(R) gravity by
  chameleon approach

abstract:
  We study constraints on f(R) dark energy models from solar system experiments
combined with experiments on the violation of equivalence principle. When the
mass of an equivalent scalar field degree of freedom is heavy in a region with
high density, a spherically symmetric body has a thin-shell so that an
effective coupling of the fifth force is suppressed through a chameleon
mechanism. We place experimental bounds on the cosmologically viable models
recently proposed in literature which have an asymptotic form f(R)=R-lambda R_c
[1-(R_c/R)^{2n}] in the regime R >> R_c. From the solar-system constraints on
the post-Newtonian parameter gamma, we derive the bound n>0.5, whereas the
constraints from the violations of weak and strong equivalence principles give
the bound n>0.9. This allows a possibility to find the deviation from the
LambdaCDM cosmological model. For the model f(R)=R-lambda R_c(R/R_c)^p with
0<p<1 the severest constraint is found to be p<10^{-10}, which shows that this
model is hardly distinguishable from the LambdaCDM cosmology.


title:
Ordered Phases of the Anisotropic Kagome Lattice Antiferromagnet in a
  Field

abstract:
  The antiferromagnetic Heisenberg model on an anisotropic kagome lattice may
be a good minimal model for real magnetic systems as well as a limit from which
the isotropic case can be better understood. We therefore study the
nearest-neighbor Heisenberg antiferromagnet on an anisotropic kagome lattice in
a magnetic field. Such a system should be well described by weakly interacting
spin chains, and we motivate a general form for the interaction by symmetry
considerations and by perturbatively projecting out the inter-chain spins. In
the spin 1/2 case, we find that the system exhibits a quantum phase transition
from a ferrimagnetic ordered state to an XY ordered state as the field is
increased. Finally, we discuss the appearance of magnetization plateaux in the
ferrimagnetic phase.


title: A Realization of Measurable Sets as Limit Points

abstract:
  Starting with a sigma finite measure on an algebra, we define a pseudometric
and show how measurable sets from the Caratheodory Extension Theorem can be
thought of as limit points of Cauchy sequences in the algebra.


title:
One- and two-dimensional Coulomb Green's function matrices in parabolic
  Sturmians basis

abstract:
  One- and two-dimensional operators which originate from the asymptotic form
of the three-body Coulomb wave equation in parabolic coordinates are treated
within the context of square integrable basis set. The matrix representations
of Green's functions corresponding to these operators are obtained.


title: Symmetry aspects of nonholonomic field theories

abstract:
  The developments in this paper are concerned with nonholonomic field theories
in the presence of symmetries. Having previously treated the case of vertical
symmetries, we now deal with the case where the symmetry action can also have a
horizontal component. As a first step in this direction, we derive a new and
convenient form of the field equations of a nonholonomic field theory.
Nonholonomic symmetries are then introduced as symmetry generators whose
virtual work is zero along the constraint submanifold, and we show that for
every such symmetry, there exists a so-called momentum equation, describing the
evolution of the associated component of the momentum map. Keeping up with the
underlying geometric philosophy, a small modification of the derivation of the
momentum lemma allows us to treat also generalized nonholonomic symmetries,
which are vector fields along a projection. Such symmetries arise for example
in practical examples of nonholonomic field theories such as the Cosserat rod,
for which we recover both energy conservation (a previously known result), as
well as a modified conservation law associated with spatial translations.


title:
Fabrication of high performance MgB2 wires by an internal Mg diffusion
  process

abstract:
  We succeeded in the fabrication of high-Jc MgB2/Fe wires applying the
internal Mg diffusion (IMD) process with pure Mg core and SiC addition. A pure
Mg rod with 2 mm diameter was placed at the center of a Fe tube, and the space
between Mg and Fe tube was filled with B powder or the powder mixture of
B-(5mol%)SiC. The composite was cold worked into 1.2mm diameter wire and
finally heat treated at temperatures above the melting point of Mg(~650oC).
During the heat treatment liquid Mg infiltrated into B layer and reacted with B
to form MgB2. X-ray diffraction analysis indicated that the major phase in the
reacted layer is MgB2. SEM analysis shows that the density of MgB2 layer is
higher than that of usual powder-in-tube(PIT) processed wires. The wires with
5mol% SiC addition heat treated at 670oC showed Jc values higher than 105A/cm2
in 8T and 41,000A/cm2 in 10T at 4.2K. These values are much higher than those
of usual PIT processed wires even compared to the ones with SiC addition.
Higher density of MgB2 layer obtained by the diffusion reaction is the major
cause of this excellent Jc values.


title:
Distributed MAC Strategy for Exploiting Multi-user Diversity in
  Multi-rate IEEE 802.11 Wireless LANs

abstract:
  Fast rate adaptation has been established as an effective way to improve the
PHY-layer raw date rate of wireless networks. However, within the current IEEE
802.11 legacy, MAC-layer throughput is dominated by users with the lowest data
rates, resulting in underutilization of bandwidth. In this paper, we propose
and analyze a novel distributed MAC strategy, referred to as Rate-aware DCF
(R-DCF), to leverage the potential of rate adaptation in IEEE 802.11 WLANs. The
key feature of R-DCF is that by introducing different mini slots according to
the instantaneous channel conditions, only contending stations with the highest
data rate can access the channel. In this way, the R-DCF protocol not only
exploits multi-user diversity in a fully distributed manner but also reduces
the loss of throughput due to collisions. Through analysis, we develop an
analytical model to derive the throughput of R-DCF in general multi-rate WLANs.
Using the analytical model we investigate the performance of R-DCF protocol in
various network settings with different rate adaptation strategies and channel
variations. Based on the analysis, we further derive the maximal throughput
achievable by R-DCF. For practical implementation, an offline adaptive backoff
method is developed to achieve a close-to-optimal performance at low runtime
complexity. The superiority of R-DCF is proven via extensive analyses and
simulations.


title:
PLATYPUS: a code for fusion and breakup in reactions induced by
  weakly-bound nuclei within a classical trajectory model with stochastic
  breakup

abstract:
  A self-contained Fortran-90 program based on a classical trajectory model
with stochastic breakup is presented, which should be a powerful tool for
quantifying complete and incomplete fusion, and breakup in reactions induced by
weakly-bound two-body projectiles near the Coulomb barrier. The code calculates
complete and incomplete fusion cross sections and their angular momentum
distribution, as well as breakup observables (angle, kinetic energy and
relative energy distributions).


title:
Approximation and limit theorems for quantum stochastic models with
  unbounded coefficients

abstract:
  We prove a limit theorem for quantum stochastic differential equations with
unbounded coefficients which extends the Trotter-Kato theorem for contraction
semigroups. From this theorem, general results on the convergence of
approximations and singular perturbations are obtained. The results are
illustrated in several examples of physical interest.


title: High-resolution temporal constraints on the dynamics of dark energy

abstract:
  We use the recent type Ia supernova, cosmic microwave background and
large-scale structure data to shed light on the temporal evolution of the dark
energy equation of state $w(z)$ out to redshift one. We constrain the most
flexible parametrization of dark energy to date, and include the dark energy
perturbations consistently throughout. Interpreting our results via the
principal component analysis, we find no significant evidence for dynamical
dark energy: the cosmological constant model is consistent with data everywhere
between redshift zero and one at 95% C.L.


title: Carbon in the trigonal prismatic environment of rheniums complexes

abstract:
  The electronic state of carbon in trigonal prismatic environment of rheniums
was studied with electron localization function and was shown to be
characterized by sp2 hybridisation and oxidation state minus 4.


title: A Cheerful Introduction to Forcing and the Continuum Hypothesis

abstract:
  This is an introduction to the set-theoretic method of forcing, including its
application in proving the independence of the Continuum Hypothesis from the
Zermelo-Fraenkel axioms of set theory. I presuppose no particular mathematical
background beyond some familiarity with set theory and mathematical logic - in
particular, no algebra is presupposed, though it can be useful. The goal is to
have a document that makes this material accessible to mathematics graduate
students in all fields, and to philosophers with an interest in set theory and
mathematical logic but no other mathematical background.


title: The assembly bias of dark matter haloes to higher orders

abstract:
  We use an extremely large volume ($2.4h^{-3}{\rm Gpc}^{3}$), high resolution
N-body simulation to measure the higher order clustering of dark matter haloes
as a function of mass and internal structure. As a result of the large
simulation volume and the use of a novel ``cross-moment'' counts-in-cells
technique which suppresses discreteness noise, we are able to measure the
clustering of haloes corresponding to rarer peaks than was possible in previous
studies; the rarest haloes for which we measure the variance are 100 times more
clustered than the dark matter. We are able to extract, for the first time,
halo bias parameters from linear up to fourth order. For all orders measured,
we find that the bias parameters are a strong function of mass for haloes more
massive than the characteristic mass $M_{*}$. Currently, no theoretical model
is able to reproduce this mass dependence closely. We find that the bias
parameters also depend on the internal structure of the halo up to fourth
order. For haloes more massive than $M_{*}$, we find that the more concentrated
haloes are more weakly clustered than the less concentrated ones. We see no
dependence of clustering on concentration for haloes with masses $M<M_{*}$;
this is contrary to the trend reported in the literature when segregating
haloes by their formation time. Our results are insensitive to whether haloes
are labelled by the total mass returned by the friends-of-friends group finder
or by the mass of the most massive substructure. This implies that our
conclusions are not an artefact of the particular choice of group finding
algorithm. Our results will provide important input to theoretical models of
galaxy clustering.


title: Type IIA orientifolds and orbifolds on non-factorizable tori

abstract:
  We investigate Type II orientifolds on non-factorizable torus with and
without its oribifolding. We explicitly calculate the Ramond-Ramond tadpole
from string one-loop amplitudes, and confirm that the consistent number of
orientifold planes is directly derived from the Lefschetz fixed point theorem.
We furthermore classify orientifolds on non-factorizable Z_N x Z_M orbifolds,
and construct new supersymmetric Type IIA orientifold models on them.


title:
Stability of de Sitter spacetime under isotropic perturbations in
  semiclassical gravity

abstract:
  A spatially flat Robertson-Walker spacetime driven by a cosmological constant
is non-conformally coupled to a massless scalar field. The equations of
semiclassical gravity are explicitly solved for this case, and a
self-consistent de Sitter solution associated with the Bunch-Davies vacuum
state is found (the effect of the quantum field is to shift slightly the
effective cosmological constant). Furthermore, it is shown that the corrected
de Sitter spacetime is stable under spatially-isotropic perturbations of the
metric and the quantum state. These results are independent of the free
renormalization parameters.


title: Dynamical Coupled-Channels Effects on Pion Photoproduction

abstract:
  The electromagnetic pion production reactions are investigated within the
dynamical coupled-channels model developed in {\bf Physics Reports, 439, 193
(2007)}. The meson-baryon channels included in this study are $\gamma N$, $\pi
N$, $\eta N$, and the $\pi\Delta$, $\rho N$ and $\sigma N$ resonant components
of the $\pi\pi N$ channel. With the hadronic parameters of the model determined
in a recent study of $\pi N$ scattering, we show that the pion photoproduction
data up to the second resonance region can be described to a very large extent
by only adjusting the bare $\gamma N \to N^*$ helicity amplitudes, while the
non-resonant electromagnetic couplings are taken from previous works. It is
found that the coupled-channels effects can contribute about 10 - 20 % of the
production cross sections in the $\Delta$ (1232) resonance region, and can
drastically change the magnitude and shape of the cross sections in the second
resonance region. The importance of the off-shell effects in a dynamical
approach is also demonstrated. The meson cloud effects as well as the
coupled-channels contributions to the $\gamma N \to N^*$ form factors are found
to be mainly in the low $Q^2$ region. For the magnetic M1 $\gamma N \to \Delta$
(1232) form factor, the results are close to that of the Sato-Lee Model.
Necessary improvements to the model and future developments are discussed.


title:
The PennState/Toru\'n Center for Astronomy Search for Planets around
  Evolved Stars

abstract:
  We present the motivation for and the first results from a large radial
velocity search for planets around red giants with the 9.2-m Hobby-Eberly
Telescope.


title:
The PSU/TCfA Search for Planets Around Evolved Stars: Bisector Analysis
  of Activity of a Sample of Red Giants

abstract:
  Searches for planets around evolved G-K subgiant and giant stars are
essential for developing general understanding of planet formation and
evolution of the planetary systems. Precise radial velocity (RV) measurements
of giants have lead to the discovery of ten planets around such star. However,
the long period radial velocity variations of red giants may also have other
than planetary nature. Non-radial oscillations or rotational modulation due to
starspots can also induce RV variations, thereby mimicking the gravitational
influence of low-mass companions. In this work we present bisector analysis of
five carefully selected lines for two stars from our survey.


title:
The PSU/TCfA Search for Planets Around Evolved Stars: Vsin(i)
  Measurements for Slow Rotating F-K Giants

abstract:
  We present results of our projected rotational velocities (Vsin(i))
measurements of F, G and K giants obtained from the cross-correlation function
(CCF) constructed from high signal to noise spectra. We also present the
calibration of the HET/HRS cross-correlation function to determine accurate
projected rotational velocities Vsin(i) for slowly-rotating F-K giants.


title:
The PennState/Toru\'n Center for Astronomy Search for Planets Around
  Evolved Stars. Basic parameters of a sample of evolved stars

abstract:
  The objective of the PSU/TCfA Search for Planets Around Evolved Stars is to
study evolution of planetary systems in the stellar evolution timescale. For
such an analysis precise physical parameters of the hosts of the planetary
systems are essential. In this paper we present an attempt to obtain basic
physical parameters for a sample of evolved stars observed within our survey
with the High Resolution Spectrograph of the Hobby-Eberly Telescope.


title: CP Measurement in Quantum Teleportation of Neutral Mesons

abstract:
  Quantum teleportation using neutral pseudoscalar mesons shows novel
connections between particle physics and quantum information. The projection
basis, which is crucial in the teleportation process, is determined by the
conservation laws of particle physics, and is different from the Bell basis, as
in the usual case. Here we show that one can verify the teleportation process
by CP measurement. This method significantly simplifies the high energy quantum
teleportation protocol. Especially, it is rigorous, and is independent of
whether CP is violated in weak decays. This method can also be applied to
general verification of Einstein-Podolsky-Rosen correlations in particle
physics.


title: Non-equilibrium thermodynamics near the horizon and holography

abstract:
  Small perturbations of a black brane are interpreted as small deviations from
thermodynamic equilibrium in a dual theory with the AdS/CFT correspondence. In
this paper, we calculate hydrodynamics of the dual Yang-Mills theory in the
gravity side using membrane paradigm. This method is different from the usual
AdS/CFT correspondence and evaluate classical solutions not at boundaries but
at the place slightly away from a horizon. There are sound modes or shear modes
for gravity perturbation. For sound modes, such calculation at the horizon has
not yet been done. Then, we find that boundary stress tensor at the horizon
satisfies conservation law in flat space and can represent dissipative parts of
stress tensor in the dual theory by holography. Using them, we can read off
directly shear and bulk viscosity of the dual theory. Quasinormal modes are
solutions to linearized equations obeyed by classical fluctuations of a
gravitational background subject to specific boundary conditions and are also
gauge-invariant quantities. We use solutions for each fluctuation that compose
such quantities and show that quasinormal modes are consistent with the
membrane paradigm.


title: Irreducible plane sextics with large fundamental groups

abstract:
  We compute the fundamental group of the complement of each irreducible sextic
of weight eight or nine (in a sense, the largest groups for irreducible
sextics), as well as of 169 of their derivatives (both of and not of torus
type). We also give a detailed geometric description of sextics of weight eight
and nine and of their moduli spaces and compute their Alexander modules; the
latter are shown to be free over an appropriate ring.


title:
Phase Structure and Critical Behavior of Multi-Higgs U(1) Lattice Gauge
  Theory in Three Dimensions

abstract:
  We study the three-dimensional (3D) compact U(1) lattice gauge theory coupled
with $N$-flavor Higgs fields by means of the Monte Carlo simulations. This
model is relevant to multi-component superconductors, antiferromagnetic spin
systems in easy plane, inflational cosmology, etc. It is known that there is no
phase transition in the N=1 model. For N=2, we found that the system has a
second-order phase transition line $\tilde{c}_1(c_2)$ in the $c_2$(gauge
coupling)$-c_1$(Higgs coupling) plane, which separates the confinement phase
and the Higgs phase. Numerical results suggest that the phase transition
belongs to the universality class of the 3D XY model as the previous works by
Babaev et al. and Smiseth et al. suggested. For N=3, we found that there exists
a critical line similar to that in the N=2 model, but the critical line is
separated into two parts; one for $c_2 < c_{2{\rm tc}}=2.4\pm 0.1$ with
first-order transitions, and the other for $ c_{2{\rm tc}} < c_2$ with
second-order transitions, indicating the existence of a tricritical point. We
verified that similar phase diagram appears for the N=4 and N=5 systems. We
also studied the case of anistropic Higgs coupling in the N=3 model and found
that there appear two second-order phase transitions or a single second-order
transition and a crossover depending on the values of the anisotropic Higgs
couplings. This result indicates that an "enhancement" of phase transition
occurs when multiple phase transitions coincide at a certain point in the
parameter space.


title: QCD factorization at twist-3: the two parton contributions

abstract:
  In this paper, the twist-3 two parton corrections in charmless $B\to PP$
decays are shown to be factorizable under the QCD factorization approach. The
factorizability of the twist-3 two parton corrections is constructed on the
following findings. Under the energetic meson limit, the pseudoscalar
distribution amplitude for a light pseudoscalar meson is allowed to be
non-constant by the equations of motion for the quark. The non-constant
pseudoscalar distribution amplitude is then used to regularize the end-point
divergences in the hard spectator corrections at twist-3 order. By retaining
the momentum fraction variable of the spectator quark of the $B$ meson in the
propagators, the end-point divergence in the weak annihilation corrections at
twist-3 order is resolved. The factorization of the $O(\alpha_s)$ corrections
under the two parton approximation is shown valid up-to $O(1/m_b)$ . The hard
scattering kernels of order $O(\alpha_s)$ and $O(\Lambda_{QCD}/m_b)$ are
explicitly given and found to be infrared finite. The results are applied for
making predictions for the branching ratios of $B\to \pi K $ decays.


title:
Representation theory of the $\alpha$-determinant and zonal spherical
  functions

abstract:
  We prove that the multiplicity of each irreducible component in the
$\mathcal{U}(\mathfrak{gl}_n)$-cyclic module generated by the $l$-th power
$\det^{(\alpha)}(X)^l$ of the $\alpha$-determinant is given by the rank of a
matrix whose entries are given by a variation of the spherical Fourier
transformation for $(\mathfrak{S}_{nl},\mathfrak{S}_l^n)$. Further, we
calculate the matrix explicitly when $n=2$. This gives not only another proof
of the result by Kimoto-Matsumoto-Wakayama (2007) but also a new aspect of the
representation theory of the $\alpha$-determinants.


title: On the Solar System-Debris Disk Connecction

abstract:
  This paper emphasizes the connection between solar and extra-solar debris
disks: how models and observations of the Solar System are helping us
understand the debris disk phenomenon, and vice versa, how debris disks are
helping us place our Solar System into context.


title: Efficient One-way Quantum Computations for Quantum Error Correction

abstract:
  We show how to explicitly construct an $O(nd)$ size and constant quantum
depth circuit which encodes any given $n$-qubit stabilizer code with $d$
generators. Our construction is derived using the graphic description for
stabilizer codes and the one-way quantum computation model. Our result
demonstrates how to use cluster states as scalable resources for many
multi-qubit entangled states and how to use the one-way quantum computation
model to improve design of quantum algorithms.


title:
Lusztig's conjecture for finite classical groups with even
  characteristic

abstract:
  The determination of scalars involved in Lusztig's conjecture for finite
reductive groups $G(F_q)$ was achieved by Waldspurger in the case of symplectic
groups or orthogonal groups, under the condition that $p,q$ are large enough.
Here $p$ is the characteristic of the finite field $F_q$. In this paper, we
determine the scalars in the case of symplectic groups with $p = 2$, by
applying the theory of symmetric spaces over a finite field due to Kawanaka and
Lusztig. We also obtain a partial result in the case of special orthogonal
groups with $p = 2$.


title: A HET search for planets around evolved stars

abstract:
  We present our ongoing survey of ~1000 GK-giants with the 9.2-m Hobby-Eberly
Telescope in search for planets around evolved stars. The stars selected for
this survey are brighter than 11 mag and are located in the section of the
HR-diagram, which is approximately delimited by the main sequence, the
instability strip, and the coronal dividing line. We use the High Resolution
Spectrograph to obtain stellar spectra for radial velocity measurements with a
4-6 m/s precision. So far, the survey has discovered a planetary-mass companion
to the K0-giant HD 17092, and it has produced a number of plausible planet
candidates around other stars. Together with other similar efforts, our program
provides information on planet formation around intermediate mass main
sequence-progenitors and it will create the experimental basis with which to
study dynamics of planetary systems around evolving stars.


title:
The PSU/TCfA Search for Planets around Evolved Stars. Stellar parameters
  and activity indicators of targets

abstract:
  The main objective of the Penn State/Torun Centre for Astronomy Search for
Planets around Evolved Stars is the detection of planetary systems around
massive, evolved stars. We are also interested in the evolution of these
systems on stellar evolution timescales. In this paper we present our approach
to determine the basic physical parameters of our targets GK-giants. We also
discuss the stellar activity indicators used in our survey: line bisector and
curvature, and Halpha variability.


title: What is a superrigid subgroup?

abstract:
  This is an expository paper. It is well known that a linear transformation
can be defined to have any desired action on a basis. From this fact, one can
show that every group homomorphism from Z^k to R^d extends to a homomorphism
from R^k to R^d, and we will see other examples of discrete subgroups H of
connected groups G, such that the homomorphisms defined on $H$ can ("almost")
be extended to homomorphisms defined on all of G. This is related to a very
classical topic in geometry, the study of linkages.


title: Simulations of the periodic flaring rate on YY Gem

abstract:
  The binary YY Gem shows many interesting properties, one of which is the
periodicity in its flaring rate. The period, which is about $48 \pm 3$ min, was
ever interpreted in terms of the oscillation of a filament. In this paper, we
propose a new model to explain this phenomenon by means of 2.5-dimensional MHD
numerical simulations. It is found that magnetic reconnection is induced as the
coronal loops rooted on both stars inflate and approach each other, which is
driven by the differential stellar rotation. The magnetic reconnection is
modulated by fast-mode magnetoacoustic waves which are trapped between the
surfaces of the two stars, so that the reconnection rate presents a periodic
behaviour. With the typical parameters for the binary system, the observed
period can be reproduced. We also derive an empirical formula to relate the
period of the flaring rate to the coronal temperature and density, as well as
the magnetic field.


title:
Galaxy Orbits for Galaxy Clusters in Sloan Digital Sky Survey and 2dF
  Galaxy Redshift Survey

abstract:
  We present the results of a study for galaxy orbits in galaxy clusters using
a spectroscopic sample of galaxies in Sloan Digital Sky Survey (SDSS) and 2dF
Galaxy Redshift Survey (2dFGRS). We have determined the member galaxies of
Abell clusters covered by these surveys using the galaxies' redshift and
positional data. We have selected 10 clusters using three criteria: the number
of member galaxies is greater than or equal to 40, the spatial coverage is
complete, and X-ray mass profile is available in the literature. We derive the
radial profile of the galaxy number density and velocity dispersion using all,
early-type, and late-type galaxies for each cluster. We have investigated the
galaxy orbits for our sample clusters with constant and variable velocity
anisotropies over the clustercentric distance using Jeans equation. Using all
member galaxies, the galaxy orbits are found to be isotropic within the
uncertainty for most of sample clusters, although it is difficult to conclude
strongly for some clusters due the large errors and the variation as a function
of the clustercentric distance in the calculated velocity anisotropies. We
investigated the orbital difference between early-type and late-type galaxies
for four sample clusters, and found no significant difference between them.


title:
Data access optimizations for highly threaded multi-core CPUs with
  multiple memory controllers

abstract:
  Processor and system architectures that feature multiple memory controllers
are prone to show bottlenecks and erratic performance numbers on codes with
regular access patterns. Although such effects are well known in the form of
cache thrashing and aliasing conflicts, they become more severe when memory
access is involved. Using the new Sun UltraSPARC T2 processor as a prototypical
multi-core design, we analyze performance patterns in low-level and application
benchmarks and show ways to circumvent bottlenecks by careful data layout and
padding.


title:
The Standing Wave Phenomenon in Radio Telescopes; Frequency Modulation
  of the WSRT Primary Beam

abstract:
  Inadequacies in the knowledge of the primary beam response of current
interferometric arrays often form a limitation to the image fidelity. We hope
to overcome these limitations by constructing a frequency-resolved,
full-polarization empirical model for the primary beam of the Westerbork
Synthesis Radio Telescope (WSRT). Holographic observations, sampling angular
scales between about 5 arcmin and 11 degrees, were obtained of a bright compact
source (3C147). These permitted measurement of voltage response patterns for
seven of the fourteen telescopes in the array and allowed calculation of the
mean cross-correlated power beam. Good sampling of the main-lobe, near-in, and
far-side-lobes out to a radius of more than 5 degrees was obtained. A robust
empirical beam model was detemined in all polarization products and at
frequencies between 1322 and 1457 MHz with 1 MHz resolution. Substantial
departures from axi-symmetry are apparent in the main-lobe as well as
systematic differences between the polarization properties. Surprisingly, many
beam properties are modulated at the 5 to 10% level with changing frequency.
These include: (1) the main beam area, (2) the side-lobe to main-lobe power
ratio, and (3) the effective telescope aperture. These semi-sinusoidsal
modulations have a basic period of about 17 MHz, consistent with the natural
'standing wave' period of a 8.75 m focal distance. The deduced frequency
modulations of the beam pattern were verified in an independent long duration
observation using compact continuum sources at very large off-axis distances.
Application of our frequency-resolved beam model should enable higher dynamic
range and improved image fidelity for interferometric observations in complex
fields. (abridged)


title:
On simultaneous rational approximations to a real number, its square,
  and its cube

abstract:
  We provide an upper bound on the uniform exponent of approximation to a
triple (xi, xi^2, xi^3) by rational numbers with the same denominator, valid
for any transcendental real number xi. This upper bound refines a previous
result of Davenport and Schmidt. As a consequence, we get a sharper lower bound
on the exponent of approximation of such a number xi by algebraic integers of
degree at most 4.


title: Electric self inductance of quasi-2D magnetic-dipolar-mode ferrite disks

abstract:
  An electric current flowing around a loop produces a magnetic field and hence
a magnetic flux through the loop. The ratio of the magnetic flux to the
electric current is called the (magnetic) self inductance. Can there be a dual
situation with a magnetic current flowing around a loop and producing an
electric field and hence an electric flux through the loop? Following the
classical electrodynamics laws an answer to this question should be negative.
Nevertheless special spectral properties of magnetic dipolar modes in a
quasi-2D ferrite disk show there are the double-valued-function loop magnetic
currents which may produce eigen electric fields and hence eigen electric
fluxes through the loop. In this case one can definitely introduce the notion
of the electric self inductance as the ratio of the electric flux to the
magnetic current. In this paper we show experimentally that in the
magnetic-dipolar-mode ferrite disks there exist eigen electric fluxes. These
fluxes are very sensitive to permittivity parameters of materials abutting to
the ferrite disk. Dielectric samples above a ferrite disk with a higher
permittivity than air confine the electric field closely outside the ferrite,
thereby changing the loop magnetic currents and thus transforming the
magnetic-dipolar-mode oscillating spectrum.


title:
Time-dependent density-functional theory with self-interaction
  correction

abstract:
  We discuss an extension of time-dependent density-functional theory by a
self-interaction correction (SIC). A strictly variational formulation is given
taking care of the necessary constraints. A manageable and transparent
propagation scheme using two sets of wavefunctions is proposed and applied to
laser excitation with subsequent ionization of a dimer molecule.


title:
On the local and non-local content of bipartite qubit and qutrit
  correlations

abstract:
  The local and non-local contents of non-local probability distributions are
studied using the approach of Elitzur, Popescu and Rohrlich [Phys. Lett. A
\textbf{162}, 25 (1992)]. This work focuses on distributions that can be
obtained by single-copy von Neumann measurements on bipartite quantum systems.
For pure two-qubit states Psi(theta)=cos(theta)|00>+sin(theta)|11>, with
cos(theta)>=sin(theta), the local content of the corresponding probability
distribution is found to lie between 1-sin(2*theta) and cos(2*theta). For the
family Psi(gamma)= (|00>+|11>+gamma*|22>)/sqrt(2+gamma^2) of two-qutrit states,
non-zero local content is found for gamma>2.


title: How to compute the Stanley depth of a monomial ideal

abstract:
  Let $J\subset I$ be monomial ideals. We show that the Stanley depth of $I/J$
can be computed in a finite number of steps. We also introduce the $\fdepth$ of
a monomial ideal which is defined in terms of prime filtrations and show that
it can also be computed in a finite number of steps. In both cases it is shown
that these invariants can be determined by considering partitions of suitable
finite posets into intervals.


title: The $n$-Queens Problem in Higher Dimensions

abstract:
  A well-known chessboard problem is that of placing eight queens on the
chessboard so that no two queens are able to attack each other. (Recall that a
queen can attack anything on the same row, column, or diagonal as itself.) This
problem is known to have been studied by Gauss, and can be generalized to an (n
\times n) board, where (n \geq 4). We consider this problem in $d$-dimensional
chess spaces, where (d \geq 3), and obtain the result that in higher
dimensions, $n$ queens do not always suffice (in any arrangement) to attack all
board positions. Our methods allow us to obtain the first lower bound on the
number of queens that are necessary to attack all positions in a
$d$-dimensional chess space of size $n$, and further to show that for any $k$,
there are higher-dimensional chess spaces in which not all positions can be
attacked by (n^k) queens.


title: From Boltzmann-Gibbs ensemble to generalized ensembles

abstract:
  We reconsider the Boltzmann-Gibbs statistical ensemble in thermodynamics
using the multinomial coefficient approach. We show that an ensemble is defined
by the determination of four statistical quantities, the element probabilities
$p_i$, the configuration probabilities $P_j$, the entropy $S$ and the extremum
constraints (EC). This distinction is of central importance for the
understanding of the conditions under which a microcanonical, canonical and
macrocanonical ensemble is defined. These three ensembles are characterized by
the conservation of their sizes. A variation of the ensemble size creates
difficulties in the definitions of the quadruplet $\{p_i, P_j, S, \mt{EC}\}$,
giving rise for a generalization of the Boltzmann-Gibbs formalism, such one as
introduced by Tsallis. We demonstrate that generalized thermodynamics represent
a transformation of ordinary thermodynamics in such a way that the energy of
the system remains conserved.
  From our results it becomes evident that Tsallis's formalism is a very
specific generalization, however, not the only one. We also revisit the
Jaynes's Maximum Entropy Principle, showing that in general it can lead to
incorrect results and consider the appropriate corrections.


title: Conformal maps from a 2-torus to the 4-sphere

abstract:
  We study the space of conformal immersions of a 2-torus into the 4-sphere.
The moduli space of generalized Darboux transforms of such an immersed torus
has the structure of a Riemann surface, the spectral curve. This Riemann
surface arises as the zero locus of the determinant of a holomorphic family of
Dirac type operators parameterized over the complexified dual torus. The kernel
line bundle of this family over the spectral curve describes the generalized
Darboux transforms of the conformally immersed torus. If the spectral curve has
finite genus the kernel bundle can be extended to the compactification of the
spectral curve and we obtain a linear 2-torus worth of algebraic curves in
projective 3-space. The original conformal immersion of the 2-torus is
recovered as the orbit under this family of the point at infinity on the
spectral curve projected to the 4-sphere via the twistor fibration.


title:
Positrons from dark matter annihilation in the galactic halo:
  theoretical uncertainties

abstract:
  Indirect detection signals from dark matter annihilation are studied in the
positron channel. We discuss in detail the positron propagation inside the
galactic medium: we present novel solutions of the diffusion and propagation
equations and we focus on the determination of the astrophysical uncertainties
which affect the positron dark matter signal. We find dark matter scenarios and
propagation models that nicely fit existing data on the positron fraction.
Finally, we present predictions both on the positron fraction and on the flux
for already running or planned space experiments, concluding that they have the
potential to discriminate a possible signal from the background and, in some
cases, to distinguish among different astrophysical propagation models.


title:
Critical dynamics of ballistic and Brownian particles in a heterogeneous
  environment

abstract:
  The dynamic properties of a classical tracer particle in a random, disordered
medium are investigated close to the localization transition. For Lorentz
models obeying Newtonian and diffusive motion at the microscale, we have
performed large-scale computer simulations, demonstrating that universality
holds at long times in the immediate vicinity of the transition. The scaling
function describing the crossover from anomalous transport to diffusive motion
is found to vary extremely slowly and spans at least 5 decades in time. To
extract the scaling function, one has to allow for the leading universal
corrections to scaling. Our findings suggest that apparent power laws with
varying exponents generically occur and dominate experimentally accessible time
windows as soon as the heterogeneities cover a decade in length scale. We
extract the divergent length scales, quantify the spatial heterogeneities in
terms of the non-Gaussian parameter, and corroborate our results by a thorough
finite-size analysis.


title: Side-gated transport in FIB-fabricated multilayered graphene nanoribbons

abstract:
  In this Letter, we present the patterning, exfoliation and micromanipulation
of thin graphitic discs which are subsequently connected and patterned into
sub-100nm wide ribbons with a resist-free process using Focused Ion Beam (FIB)
lithography and deposition. The electronic transport properties of the double
side-gated nanoribbons are then investigated down to 40 K and interpreted with
a simple model of 1D array of tunnelling junctions.


title: Phase switching in a voltage-biased Aharonov-Bohm interferometer

abstract:
  Recent experiment [Sigrist et al., Phys. Rev. Lett. {\bf 98}, 036805 (2007)]
reported switches between 0 and $\pi$ in the phase of Aharonov-Bohm
oscillations of the two-terminal differential conductance through a two-dot
ring with increasing voltage bias. Using a simple model, where one of the dots
contains multiple interacting levels, these findings are explained as a result
of transport through the interferometer being dominated at different biases by
quantum dot levels of different "parity" (i.e. the sign of the overlap integral
between the dot state and the states in the leads). The redistribution of
electron population between different levels with bias leads to the fact that
the number of switching events is not necessarily equal to the number of dot
levels, in agreement with experiment. For the same reason switching does not
always imply that the parity of levels is strictly alternating. Lastly, it is
demonstrated that the correlation between the first switching of the phase and
the onset of the inelastic cotunneling, as well as the sharp (rather than
gradual) change of phase when switching occurs, give reason to think that the
present interpretation of the experiment is preferable to the one based on
electrostatic AB effect.


title:
Boundary Ring or a Way to Construct Approximate NG Solutions with
  Polygon Boundary Conditions. II. Polygons which admit an inscribed circle

abstract:
  We further develop the formalism of arXiv:0712.0159 for approximate solution
of Nambu-Goto (NG) equations with polygon conditions in AdS backgrounds, needed
in modern studies of the string/gauge duality. Inscribed circle condition is
preserved, which leaves only one unknown function y_0(y_1,y_2) to solve for,
what considerably simplifies our presentation. The problem is to find a
delicate balance -- if not exact match -- between two different structures: NG
equation -- a non-linear deformation of Laplace equation with solutions
non-linearly deviating from holomorphic functions, -- and the boundary ring,
associated with polygons made from null segments in Minkovski space. We provide
more details about the theory of these structures and suggest an extended class
of functions to be used at the next stage of Alday-Maldacena program:
evaluation of regularized NG actions.


title: A nonlinear Stein based estimator for multichannel image denoising

abstract:
  The use of multicomponent images has become widespread with the improvement
of multisensor systems having increased spatial and spectral resolutions.
However, the observed images are often corrupted by an additive Gaussian noise.
In this paper, we are interested in multichannel image denoising based on a
multiscale representation of the images. A multivariate statistical approach is
adopted to take into account both the spatial and the inter-component
correlations existing between the different wavelet subbands. More precisely,
we propose a new parametric nonlinear estimator which generalizes many reported
denoising methods. The derivation of the optimal parameters is achieved by
applying Stein's principle in the multivariate case. Experiments performed on
multispectral remote sensing images clearly indicate that our method
outperforms conventional wavelet denoising techniques


title:
Mixed anomalies of chiral algebras compactified to smooth
  quasi-projective surfaces

abstract:
  Some time ago, the chiral algebra theory of Beilinson-Drinfeld was expected
to play a central role in the convergence of divergence in mathematical physics
of superstring theory for quantization of gauge theory and gravity. Naively,
this algebra plays an important role in a holomorphic conformal field theory
with a non-negative integer graded conformal dimension, whose target space does
not necessarily have the vanishing first Chern class. This algebra has two
definitions until now: one is that by Malikov-Schechtman-Vaintrob by gluing
affine patches, and the other is that of Kapranov-Vasserot by gluing the formal
loop spaces. I will use the new definition of Nekrasov by simplifying
Malikov-Schechtman-Vaintrob in order to compute the obstruction classes of
gerbes of chiral differential operators.
  In this paper, I will examine the two independent Ans$\"{a}$tze (or working
hypotheses) of Witten's $\mathcal{N}=(0,2)$ heterotic strings and Nekrasov's
generalized complex geometry, after Hitchin and Gualtieri, are consistent in
the case of $\mathbb{CP}^2$, which has $3$ affine patches and is expected to
have the "first Pontryagin anomaly".
  I also scrutinized the physical meanings of $2$ dimensional toric Fano
manifolds, or rather toric del Pezzo surfaces, obtained by blowing up the
non-colinear $1, 2, 3$ points of $\mathbb{CP}^2$. The obstruction classes of
gerbes of them coincide with the second Chern characters obtained by the
Riemann-Roch theorem and in particular vanishes for $1$ point blowup, which
means that one of the gravitational anomalies vanishes for a non-Calabi-Yau
manifold compactification.
  The future direction towards the geometric Langlands program is also
discussed in the last section.


title:
Room-temperature magnetoresistance switching of Py thin films induced by
  Fe-nanoparticles grown by STM-assisted CVD

abstract:
  Arrays of Fe-nanoparticles grown by STM-assited CVD have been placed on top
of a narrow stripe of Py. The magnetic coupling between the nanoparticles and
the underlying Py film results in distinct negative jumps of the Py
magnetoresistance. The switching of the magnetization orientation of individual
particles is clearly reflected in the Py magnetoresistance as a consequence of
AMR and DWMR, with a homogeneous particle magnetization orientation yielding
the highest resistances.


title:
Real forms and finite order automorphisms of affine Kac-Moody algebras -
  an outline of a new approach

abstract:
  We outline a new approach to classify real forms and automorphisms of finite
order of affine Kac-Moody algebras.


title:
Remarks on confinement driven by axion-like particles in Yang-Mills
  theories

abstract:
  Features of screening and confinement are studied for a non-Abelian gauge
theory with a mixture of pseudoscalar and scalar coupling, in the case where a
constant chromo-electric, or chromo-magnetic, strength expectation value is
present. Our discussion is carried out using the gauge-invariant but
path-dependent variables formalism. We explicitly show that the static
potential profile is the sum of a Yukawa and a linear potential, leading to the
confinement of static probe charges. Interestingly, similar results have been
obtained in the context of gluodynamics in curved space-time. For only
pseudoscalar coupling, the results are radically different.


title:
Solitons in one-dimensional nonlinear Schr\"{o}dinger lattices with a
  local inhomogeneity

abstract:
  In this paper we analyze the existence, stability, dynamical formation and
mobility properties of localized solutions in a one-dimensional system
described by the discrete nonlinear Schr\"{o}dinger equation with a linear
point defect. We consider both attractive and repulsive defects in a focusing
lattice. Among our main findings are: a) the destabilization of the on--site
mode centered at the defect in the repulsive case; b) the disappearance of
localized modes in the vicinity of the defect due to saddle-node bifurcations
for sufficiently strong defects of either type; c) the decrease of the
amplitude formation threshold for attractive and its increase for repulsive
defects; and d) the detailed elucidation as a function of initial speed and
defect strength of the different regimes (trapping, trapping and reflection,
pure reflection and pure transmission) of interaction of a moving localized
mode with the defect.


title:
On the Absolutely Continuous Spectrum of Sturm-Liouville Operators with
  Applications to Radial Quantum Trees

abstract:
  We consider standard subordinacy theory for general Sturm--Liouville
operators and give criteria when boundedness of solutions implies that no
subordinate solutions exist. As applications, we prove a Weidmann-type result
for general Sturm--Liouville operators and investigate the absolutely
continuous spectrum of radially symmetric quantum trees.


title:
Myosin V passing over Arp2/3 junctions: branching ratio calculated from
  the elastic lever arm model

abstract:
  Myosin V is a two-headed processive motor protein that walks in a
hand-over-hand fashion along actin filaments. When it encounters a filament
branch, formed by the Arp2/3 complex, it can either stay on the straight mother
filament, or switch to the daughter filament. We study both probabilities using
the elastic lever arm model for myosin V. We calculate the shapes and bending
energies of all relevant configurations in which the trail head is bound to the
actin filament before Arp2/3 and the lead head is bound either to the mother or
to the daughter filament. Based on the assumption that the probability for a
head to bind to a certain actin subunit is proportional to the Boltzmann factor
obtained from the elastic energy, we calculate the mother/daughter filament
branching ratio. Our model predicts a value of 27% for the daughter and 73% for
the mother filament. This result is in good agreement with recent experimental
data.


title: Confined Ge-Pt states in self-organized Pt nanowire arrays on Ge(001)

abstract:
  By means of band structure calculations within the density functional theory
and the generalized gradient approximation, we investigate the electronic
structure of self-organized Pt nanowires on the Ge(001) surface. In particular,
we deal with a novel one-dimensional surface state confined in the nanowire
array and clarify its origin. Due to large Pt contributions, the novel state is
rather a mixed Ge-Pt hybrid state than a confined Ge surface state. Moreover,
we compare our results to data from scanning tunneling microscopy.


title:
INTEGRAL discovery of non-thermal hard X-ray emission from the Ophiuchus
  cluster

abstract:
  We present the results of deep observations of the Ophiuchus cluster of
galaxies with INTEGRAL in the 3-80 keV band. We analyse 3 Ms of INTEGRAL data
on the Ophiuchus cluster with the IBIS/ISGRI hard X-ray imager and the JEM-X
X-ray monitor. In the X-ray band using JEM-X, we show that the source is
extended, and that the morphology is compatible with the results found by
previous missions. Above 20 keV, we show that the size of the source is
slightly larger than the PSF of the instrument, and is consistent with the soft
X-ray morphology found with JEM-X and ASCA. Thanks to the constraints on the
temperature provided by JEM-X, we show that the spectrum of the cluster is not
well fitted by a single-temperature thermal Bremsstrahlung model, and that
another spectral component is needed to explain the high energy data. We detect
the high energy tail with a higher detection significance (6.4 sigma) than the
BeppoSAX claim (2 sigma). Because of the imaging capabilities of JEM-X and
ISGRI, we are able to exclude the possibility that the excess emission comes
from very hot regions or absorbed AGN, which proves that the excess emission is
indeed of non-thermal origin. Using the available radio data together with the
non-thermal hard X-ray flux, we estimate a magnetic field B ~ 0.1-0.2 mu G.


title: Invariant Amplitudes for Pion Electroproduction

abstract:
  The invariant amplitudes for pion electroproduction on the nucleon are
evaluated by dispersion relations at constant t with MAID as input for the
imaginary parts of these amplitudes. In the threshold region these amplitudes
are confronted with the predictions of several low-energy theorems derived in
the soft-pion limit. In general agreement with Chiral Perturbation Theory, the
dispersive approach yields large corrections to these theorems because of the
finite pion mass.


title: $L^2$-stability of explicit schemes for incompressible Euler equations

abstract:
  We present an original study on the numerical stabiliy of explicit schemes
solving the incompressible Euler equations on an open domain with slipping
boundary conditions. Relying on the skewness property of the non-linear term,
we demonstrate that some explicit schemes are numerically stable for small
perturbations under the condition $\delta t\leq C \delta x^{2r/(2r-1)}$ where
$r$ is an integer, $\delta t$ the time step and $\delta x$ the space step.


title:
Fixed points of circle actions on spaces with rational cohomology of
  $S^n V S^{2n} V S^{3n}$ or $P^2(n) V S^{3n}$

abstract:
  Let $X$ be a finitistic space with its rational cohomology isomorphic to that
of the wedge sum $P^2(n)\vee S^{3n} $ or $S^{n} \vee S^{2n}\vee S^{3n}$. We
study continuous $\mathbb{S}^1$ actions on $X$ and determine the possible fixed
point sets up to rational cohomology depending on whether or not $X$ is totally
non-homologous to zero in $X_{\mathbb{S}^1}$ in the Borel fibration
$X\hookrightarrow X_{\mathbb{S}^1} \longrightarrow B_{\mathbb{S}^1}$. We also
give examples realizing the possible cases.


title: Periodic minimizers in 1D local mean field theory

abstract:
  Using reflection positivity techniques we prove the existence of minimizers
for a class of mesoscopic free-energies representing 1D systems with competing
interactions. All minimizers are either periodic, with zero average, or of
constant sign. If the local term in the free energy satisfies a convexity
condition, then all minimizers are either periodic or constant. Examples of
both phenomena are given. This extends our previous work where such results
were proved for the ground states of lattice systems with ferromagnetic nearest
neighbor interactions and dipolar type antiferromagnetic long range
interactions.


title:
Forced Imbibition - a Tool for Determining Laplace Pressure, Drag Force
  and Slip Length in Capillary Filling Experiments

abstract:
  When a very thin capillary is inserted into a liquid, the liquid is sucked
into it: this imbibition process is controlled by a balance of capillary and
drag forces, which are hard to quantify experimentally, in particularly
considering flow on the nanoscale. By computer experiments using a generic
coarse-grained model, it is shown that an analysis of imbibition forced by a
controllable external pressure quantifies relevant physical parameter such as
the Laplace pressure, Darcy's permeability, effective pore radius, effective
viscosity, dynamic contact angle and slip length of the fluid flowing into the
pore. In determining all these parameters independently, the consistency of our
analysis of such forced imbibition processes is demonstrated.


title:
From Geometry to Numerics: interdisciplinary aspects in mathematical and
  numerical relativity

abstract:
  This article reviews some aspects in the current relationship between
mathematical and numerical General Relativity. Focus is placed on the
description of isolated systems, with a particular emphasis on recent
developments in the study of black holes. Ideas concerning asymptotic flatness,
the initial value problem, the constraint equations, evolution formalisms,
geometric inequalities and quasi-local black hole horizons are discussed on the
light of the interaction between numerical and mathematical relativists.


title: Models for Dust and Molecular Emission of High-Mass Protostars

abstract:
  We present the results of a detailed modeling aimed to reproduce the spectral
energy distribution (SED) of dust and molecular line emission of massive
protostars under the hypothesis that they form via an accretion process. We
model the emission originated in the infalling envelopes at scales smaller than
0.1 pc from the central protostar. To do that, we compared our model results
with observational data covering a wide range of wavelengths, paying special
attention to the high angular resolution mid-infrared data obtained with the
Gemini Observatory and the ammonia line emission observed with the VLA at
centimeter wavelengths. We have explored two kind of model envelopes. In the
first kind of models, spherical symmetry is assumed and the SED as well as the
ammonia emission of the infalling envelope are calculated. In this way, the
temperature, density, velocity, velocity dispersion, and ammonia abundance
variations along the core can be obtained. The second approach takes into
account deviations from the spherical symmetry, and parameters such as the
rotation, degree of elongation of the core, or inclination of the system can be
constrained through the SED fitting. Using these two approaches we have been
able to model the formation of massive stars with a degree of detail similar to
that reached for the low mass stars.


title: Application of a curvature adjusted method in image segmentation

abstract:
  This article deals with flow of plane curves driven by the curvature and
external force. We make use of such a geometric flow for the purpose of image
segmentation. A parametric model for evolving curves with uniform and curvature
adjusted redistribution of grid points will be described and compared.


title: Nonlinear theory and tests of earthquake recurrence times

abstract:
  We develop an efficient numerical scheme to solve accurately the set of
nonlinear integral equations derived previously in (Saichev and Sornette,
2007), which describes the distribution of inter-event times in the framework
of a general model of earthquake clustering with long memory. Detailed
comparisons between the linear and nonlinear versions of the theory and direct
synthetic catalogs show that the nonlinear theory provides an excellent fit to
the synthetic catalogs, while there are significant biases resulting from the
use of the linear approximation. We then address the suggestions proposed by
some authors to use the empirical distribution of inter-event times to obtain a
better determination of the so-called clustering parameter. Our theory and
tests against synthetic and empirical catalogs find a rather dramatic lack of
power for the distribution of inter-event times to distinguish between quite
different sets of parameters, casting doubt on the usefulness of this
statistics for the specific purpose of identifying the clustering parameter.


title: Polarised Geant4 - Applications at the ILC

abstract:
  Geant4 is a Monte Carlo simulation framework for the description of
interactions of particles and matter. Starting with version 8.2 a new package
of QED physics processes is available, allowing for the studies of interactions
of polarised particles with polarised media dedicated to beam applications. In
this contribution some details about the implementation are presented and
applications to the linear collider are discussed.


title: Mould expansions for the saddle-node and resurgence monomials

abstract:
  This article is an introduction to some aspects of \'Ecalle's mould calculus,
a powerful combinatorial tool which yields surprisingly explicit formulas for
the normalising series attached to an analytic germ of singular vector field or
of map. This is illustrated on the case of the saddle-node, a two-dimensional
vector field which is formally conjugate to Euler's vector field
$x^2\frac{\pa}{\pa x}+(x+y)\frac{\pa}{\pa y}$, and for which the formal
normalisation is shown to be resurgent in $1/x$. Resurgence monomials adapted
to alien calculus are also described as another application of mould calculus.


title: Competing Particle Systems and the Ghirlanda-Guerra Identities

abstract:
  We study point processes on the real line whose configurations X can be
ordered decreasingly and evolve by increments which are functions of correlated
gaussian variables. The correlations are intrinsic to the points and quantified
by a matrix Q={q_ij}. Quasi-stationary systems are those for which the law of
(X,Q) is invariant under the evolution up to translation of X. It was
conjectured by Aizenman and co-authors that the matrix Q of robustly
quasi-stationary systems must exhibit a hierarchal structure. This was
established recently, up to a natural decomposition of the system, whenever the
set S_Q of values assumed by q_ij is finite. In this paper, we study the
general case where S_Q may be infinite. Using the past increments of the
evolution, we show that the law of robustly quasi-stationary systems must obey
the Ghirlanda-Guerra identities, which first appear in the study of spin glass
models. This provides strong evidence that the above conjecture also holds in
the general case.


title:
The topological meaning of Levinson's theorem, half-bound states
  included

abstract:
  We propose to interpret Levinson's theorem as an index theorem. This exhibits
its topological nature. It furthermore leads to a more coherent explanation of
the corrections due to resonances at thresholds.


title: Polarised Positrons for the ILC

abstract:
  For the planned International Linear Collider it is intended to have both --
electron and positron -- beams polarised. This offers a great benefit for many
physics studies, but also provides a challenge for the engineering of the
machine. A polarised positron source that meets the machine parameters is topic
of current design studies and prototype experiments.


title: From the Nambu-Goto the Sigma-Model Action, Memoirs from Long Ago

abstract:
  In this article I describe my own stumblings in the first string era. This
was a time when most of the active people were very young, not very
knowledgeable and the field was completely new. Many of us had little training
for what we came to work on, and it took quite some time to accomplish the new
conceptual discoveries.


title: Empirical analysis of the Lieb-Oxford bound in ions and molecules

abstract:
  Universal properties of the Coulomb interaction energy apply to all
many-electron systems. Bounds on the exchange-correlation energy, inparticular,
are important for the construction of improved density functionals. Here we
investigate one such universal property -- the Lieb-Oxford lower bound -- for
ionic and molecular systems. In recent work [J. Chem. Phys. 127, 054106
(2007)], we observed that for atoms and electron liquids this bound may be
substantially tightened. Calculations for a few ions and molecules suggested
the same tendency, but were not conclusive due to the small number of systems
considered. Here we extend that analysis to many different families of ions and
molecules, and find that for these, too, the bound can be empirically tightened
by a similar margin as for atoms and electron liquids. Tightening the
Lieb-Oxford bound will have consequences for the performance of various
approximate exchange-correlation functionals.


title: Radiation damage of the ILC positron source target

abstract:
  The radiation damage of the positron source target for the International
Linear Collider (ILC) has been studied. The displacement damage in target
material due to multi-MeV photons has been calculated by combining FLUKA
simulations for secondary particle production, SPECTER data for neutron
displacement cross-sections and the Lindhard model for estimations of
displacement damage by ions. The radiation damage of a stationary Ti6Al4V
target in units of displacements per atom (dpa) has been estimated for photons
from an undulator with strength 0.92 and period 1.15 cm. The calculated damage
is 7 dpa. Approximately 12.5% of displacement damage result from neutrons.


title: The Dynamical Mordell-Lang Conjecture

abstract:
  We prove a special case of a dynamical analogue of the classical Mordell-Lang
conjecture. In particular, let $\phi$ be a rational function with no
superattracting periodic points other than exceptional points. If the
coefficients of $\phi$ are algebraic, we show that the orbit of a point outside
the union of proper preperiodic subvarieties of $(\bP^1)^g$ has only finite
intersection with any curve contained in $(\bP^1)^g$. We also show that our
result holds for indecomposable polynomials $\phi$ with coefficients in $\bC$.
Our proof uses results from $p$-adic dynamics together with an integrality
argument. The extension to polynomials defined over $\bC$ uses the method of
specializations coupled with some new results of Medvedev and Scanlon for
describing the periodic plane curves under the action of $(\phi,\phi)$ on
$\bA^2$.


title: Inflationary NonGaussianity from Thermal Fluctuations

abstract:
  We calculate the contribution of the fluctuations with the thermal origin to
the inflationary nonGaussianity. We find that even a small component of
radiation can lead to a large nonGaussianity. We show that this thermal
nonGaussianity always has positive $f_{\rm NL}$. We illustrate our result in
the chain inflation model and the very weakly dissipative warm inflation model.
We show that $f_{NL}\sim {\cal O}(1)$ is general in such models. If we allow
modified equation of state, or some decoupling effects, the large thermal
nonGaussianity of order $f_{\rm NL}>5$ or even $f_{\rm NL}\sim 100$ can be
produced. We also show that the power spectrum of chain inflation should have a
thermal origin. In the Appendix A, we made a clarification on the different
conventions used in the literature related to the calculation of $f_{\rm NL}$.


title:
Comparison of Distances from RR Lyrae Stars, the Tip of the Red-Giant
  Branch and Classical Cepheids

abstract:
  The extragalactic distance scale relies heavily on Cepheids. However, it has
become clear from observations and pulsation models that the slope and zero
point of their P-L relations differ from galaxy to galaxy. This makes the
determination of Cepheid distances complex and calls for an independent test of
their differences. The test is provided by RR Lyrae star distances of 24
galaxies which calibrate the tip of the red-giant branch (TRGB; M_I = -4.05),
which in turn confirms the adopted Cepheids distances on our 2006 distance
scale in 18 cases to within 0.1 mag on average. Relative SN Ia and velocity
distances deny a remaining significant metallicity effect of the adopted
distances. The new support for these Cepheid distances increases the weight of
our previous calibration of the SN Ia luminosity and of the 21cm line width -
luminosity (TF) relation. The value of H_0 = 62.3 (+/-5) is confirmed on all
scales.


title: Virtual Bridge Number One Knots

abstract:
  We define the virtual bridge number $vb(K)$ and the virtual unknotting number
$vu(K)$ invariants for virtual knots. For ordinary knots $K$ they are closely
related to the bridge number $b(K)$ and the unknotting number $u(K)$ and we
have $vu(K)\leq u(K), vb(K)\leq b(K).$
  There are no ordinary knots $K$ with $b(K)=1.$ We show there are infinitely
many homotopy classes of virtual knots each of which contains infinitely many
isotopy classes of $K$ with $vb(K)=1.$ In fact for each $i\in \N$ there exists
$K$ virtually homotopic (but not virtually isotopic) to the unknot with
$vb(K)=1$ and $vu(K)=i.$


title:
Measurement of Lifetime and Decay-Width Difference in B0s -> J/psi phi
  Decays

abstract:
  We measure the mean lifetime, tau=2/(Gamma_L+Gamma_H), and the width
difference, DeltaGamma=Gamma_L-Gamma_H, of the light and heavy mass eigenstates
of the B0s meson, B0sL and B0sH, in B0s -> J/psi phi decays using 1.7 fb^-1 of
data collected with the CDF II detector at the Fermilab Tevatron ppbar
collider. Assuming CP conservation, a good approximation for the B0s system in
the Standard Model, we obtain DeltaGamma = 0.076^+0.059_-0.063 (stat.) +- 0.006
(syst.) ps^-1 and tau = 1.52 +- 0.04 (stat.) +- 0.02 (syst.) ps, the most
precise measurements to date. Our constraints on the weak phase and DeltaGamma
are consistent with CP conservation.
  Dedicated to the memory of our dear friend and colleague, Michael P. Schmidt


title: Optimization and Scale-freeness for Complex Networks

abstract:
  Complex networks are mapped to a model of boxes and balls where the balls are
distinguishable. It is shown that the scale-free size distribution of boxes
maximizes the information associated with the boxes provided configurations
including boxes containing a finite fraction of the total amount of balls are
excluded. It is conjectured that for a connected network with only links
between different nodes, the nodes with a finite fraction of links are
effectively suppressed. It is hence suggested that for such networks the
scale-free node-size distribution maximizes the information encoded on the
nodes. The noise associated with the size distributions is also obtained from a
maximum entropy principle. Finally explicit predictions from our least bias
approach are found to be born out by metabolic networks.


title:
Orbital-polarization terms: from a phenomenological to a
  first-principles description of orbital magnetism in density-functional
  theory

abstract:
  Phenomenological orbital-polarization (OP) terms have been repeatedly
introduced in the single-particle equations of spin-density-functional theory,
in order to improve the description of orbital magnetic moments in systems
containing transition metal ions. Here we show that these ad hoc corrections
can be interpreted as approximations to the exchange-correlation vector
potential A_xc of current-density-functional theory (CDFT). This connection
provides additional information on both approaches: Phenomenological OP terms
are connected to first-principles theory, leading to a rationale for their
empirical success and a reassessment of their limitations and the
approximations made in their derivation. Conversely, the connection of OP terms
with CDFT leads to a set of simple approximations to the CDFT potential A_xc,
with a number of desirable features that are absent from electron-gas-based
functionals.


title: Chaotic D-Term Inflation

abstract:
  A simple model for chaotic inflation in supergravity is proposed. The model
is N=1 supersymmetric massive U(1) gauge theory via the Stuckelberg superfield
and gives rise to D-term inflation with a quadratic term of inflaton in the
potential. The Fayet-Iliopoulos field plays a role of the inflaton.


title:
Robustly estimating the flow direction of information in complex
  physical systems

abstract:
  We propose a new measure to estimate the direction of information flux in
multivariate time series from complex systems. This measure, based on the slope
of the phase spectrum (Phase Slope Index) has invariance properties that are
important for applications in real physical or biological systems: (a) it is
strictly insensitive to mixtures of arbitrary independent sources, (b) it gives
meaningful results even if the phase spectrum is not linear, and (c) it
properly weights contributions from different frequencies. Simulations of a
class of coupled multivariate random data show that for truly unidirectional
information flow without additional noise contamination our measure detects the
correct direction as good as the standard Granger causality. For random
mixtures of independent sources Granger Causality erroneously yields highly
significant results whereas our measure correctly becomes non-significant. An
application of our novel method to EEG data (88 subjects in eyes-closed
condition) reveals a strikingly clear front-to-back information flow in the
vast majority of subjects and thus contributes to a better understanding of
information processing in the brain.


title: Recent Belle results on CP violation

abstract:
  The Belle experiment's recent results on CP violation in B meson decays are
summarized.


title:
Intrinsic optical bistability of thin films of linear molecular
  aggregates: The two-exciton approximation

abstract:
  We generalize our recent work on the optical bistability of thin films of
molecular aggregates [J. Chem. Phys. 127, 164705 (2007); arXiv:0707.1264v1
[cond-mat.dis-nn]] by accounting for the optical transitions from the
one-exciton manifold to the two-exciton manifold as well as the exciton-exciton
annihilation of the two-exciton states via a high-lying molecular vibronic
term. We also include the relaxation from the vibronic level back to both the
one-exciton manifold and the ground state. By selecting the dominant optical
transitions between the ground state, the one-exciton manifold, and the
two-exciton manifold, we reduce the problem to four levels, enabling us to
describe the nonlinear optical response of the film. The one- and two-exciton
states are obtained by diagonalizing a Frenkel Hamiltonian with an uncorrelated
on-site (diagonal) disorder. The optical dynamics is described by means of the
density matrix equations coupled to the electromagnetic field in the film. We
show that the one-to-two exciton transitions followed by a fast exciton-exciton
annihilation promote the occurrence of bistability and reduce the switching
intensity. We provide estimates of pertinent parameters for actual materials
and conclude that the effect can be realized.


title: Top pair invariant mass distribution: a window on new physics

abstract:
  We explore in detail the physics potential of a measurement of the ttbar
invariant mass distribution. First, we assess the accuracy of the best
available predictions for this observable and find that in the low invariant
mass region, the shape is very well predicted and could be used to perform a
top mass measurement. Second, we study the effects of a heavy s-channel
resonance on the ttbar invariant mass distribution, in a model independent way.
We provide the necessary Monte Carlo tools to perform the search and outline a
simple three-step analysis.


title: ILC Reference Design Report Volume 4 - Detectors

abstract:
  This report, Volume IV of the International Linear Collider Reference Design
Report, describes the detectors which will record and measure the charged and
neutral particles produced in the ILC's high energy e+e- collisions. The
physics of the ILC, and the environment of the machine-detector interface, pose
new challenges for detector design. Several conceptual designs for the detector
promise the needed performance, and ongoing detector R&D is addressing the
outstanding technological issues. Two such detectors, operating in push-pull
mode, perfectly instrument the ILC interaction region, and access the full
potential of ILC physics.


title:
At the Bottom of the Main Sequence: Activity and magnetic fields beyond
  the threshold to complete convection

abstract:
  The bottom of the main sequence hosts objects with fundamentally different
properties. At masses of about 0.3 M$_{\odot}$, stars become fully convective
and at about 0.08 M$_{\odot}$ the hydrogen-burning main sequence ends; less
massive objects are brown dwarfs. While stars and brown dwarfs experience very
different evolutions, their inner structure has relatively little impact on the
atmospheres. The generation of magnetic fields and activity is obviously
connected to the threshold between partial and complete convection, because
dynamo mechanisms involving a layer of shear like the solar
$\alpha\Omega$-dynamo must cease. Hence a change in stellar activity can be
expected there. Observations of stellar activity do not confirm a rapid break
in activity at the convection boundary, but the fraction of active stars and
rapid rotators is higher on the fully convective side. I summarize the current
picture of stellar activity and magnetic field measurements at the bottom of
the main sequence and present recent results on rotational braking beyond.


title:
Using Physics to Learn Mathematica to Do Physics: From Homework Problems
  to Research Examples

abstract:
  We describe the development of a junior-senior level course for Physics
majors designed to teach Mathematica skills in support of their undergraduate
coursework, but also to introduce students to modern research level results.
Standard introductory and intermediate level Physics homework-style problems
are used to teach Mathematica commands and programming methods, which are then
applied, in turn, to more sophisticated problems in some of the core
undergraduate subjects, along with making contact with recent research papers
in a variety of fields.


title:
Decoupling of kinematical time dilation and gravitational time dilation
  in particular geometries

abstract:
  Two different forms of time dilation, namely, the kinematical time dilation
of special relativity and gravitational red shift are coupled during
observations of systems moving through a gravitational field. In the particular
situation of free fall in a Schwarzschild geometry these two effects are
decoupled and in consequence the time dilation, as observed by a distant
observer, factorises. Such a factorization is not a universal feature. We
define here a necessary and sufficient criterion for time dilation and
gravitational red-shift decoupling. This property is manifested in a particular
form of the Doppler shift in Schwarzschild geometry.


title:
CPsuperH2.0: an Improved Computational Tool for Higgs Phenomenology in
  the MSSM with Explicit CP Violation

abstract:
  We describe the Fortran code CPsuperH2.}, which contains several improvements
and extensions of its predecessor CPsuperH. It implements improved calculations
of the Higgs-boson pole masses, notably a full treatment of the 4 times 4
neutral Higgs propagator matrix including the Goldstone boson and a more
complete treatment of threshold effects in self-energies and Yukawa couplings,
improved treatments of two-body Higgs decays, some important three-body decays,
and two-loop Higgs-mediated contributions to electric dipole moments.
CPsuperH2.0 also implements an integrated treatment of several B-meson
observables, including the branching ratios of B_s to mu^+ mu^-, B_d to tau^+
tau^-, B_u to tau nu, B to X_s gamma and the latter's CP-violating asymmetry
A_CP, and the supersymmetric contributions to the B^0_{s,d} - \bar B^0_{s,d}
mass differences. These additions make CPsuperH2.0 an attractive integrated
tool for analyzing supersymmetric CP and flavour physics as well as searches
for new physics at high-energy colliders such as the Tevatron, LHC and linear
colliders. The program may be obtained from
http://www.hep.man.ac.uk/u/jslee/CPsuperH.html


title: ILC Reference Design Report Volume 3 - Accelerator

abstract:
  The International Linear Collider (ILC) is a 200-500 GeV center-of-mass
high-luminosity linear electron-positron collider, based on 1.3 GHz
superconducting radio-frequency (SCRF) accelerating cavities. The ILC has a
total footprint of about 31 km and is designed for a peak luminosity of 2x10^34
cm^-2 s^-1. The complex includes a polarized electron source, an
undulator-based positron source, two 6.7 km circumference damping rings,
two-stage bunch compressors, two 11 km long main linacs and a 4.5 km long beam
delivery system. This report is Volume III (Accelerator) of the four volume
Reference Design Report, which describes the design and cost of the ILC.


title: Quantum Elastic Net and the Traveling Salesman Problem

abstract:
  Theory of computer calculations strongly depends on the nature of elements
the computer is made of. Quantum interference allows to formulate the Shor
factorization algorithm turned out to be more effective than any one written
for classical computers. Similarly, quantum wave packet reduction allows to
devise the Grover search algorithm which outperforms any classical one. In the
present paper we argue that the quantum incoherent tunneling can be used for
elaboration of new algorithms able to solve some NP-hard problems, such as the
Traveling Salesman Problem, considered to be intractable in the classical
theory of computer computations.


title:
Constraints on the angular distribution of satellite galaxies about
  spiral hosts

abstract:
  We present, using a novel technique, a study of the angular distribution of
satellite galaxies around a sample of isolated, blue host galaxies selected
from the sixth data release of the Sloan Digital Sky Survey. As a complement to
previous studies we subdivide the sample of galaxies into bins of differing
inclination and use the systematic differences that would exist between the
different bins as the basis for our approach. We parameterize the cumulative
distribution function of satellite galaxies and apply a maximum likelihood,
Monte-Carlo technique to determine allowable distributions, which we show as an
exclusion plot. We find that the allowed distributions of the satellites of
spiral hosts are very nearly isotropic. We outline our formalism and our
analysis and discuss how this technique may be refined for future studies and
future surveys.


title: Singularities of the Secant Variety

abstract:
  We give positivity conditions on the embedding of a smooth variety which
guarantee the normality of the secant variety, generalizing earlier results of
the author and others. We also give classes of secant varieties satisfying the
Hodge conjecture as well as a result on the singular locus of degenerate secant
varieties.


title: Ternary cyclotomic polynomials having a large coefficient

abstract:
  Let $\Phi_n(x)$ denote the $n$th cyclotomic polynomial. In 1968 Sister Marion
Beiter conjectured that $a_n(k)$, the coefficient of $x^k$ in $\Phi_n(x)$,
satisfies $|a_n(k)|\le (p+1)/2$ in case $n=pqr$ with $p<q<r$ primes (in this
case $\Phi_n(x)$ is said to be ternary). Since then several results towards
establishing her conjecture have been proved (for example $|a_n(k)|\le 3p/4$).
Here we show that, nevertheless, Beiter's conjecture is false for every $p\ge
11$. We also prove that given any $\epsilon>0$ there exist infinitely many
triples $(p_j,q_j,r_j)$ with $p_1<p_2<... $ consecutive primes such that
$|a_{p_jq_jr_j}(n_j)|>(2/3-\epsilon)p_j$ for $j\ge 1$.


title: Thermal shifts and intermittent linear response of aging systems

abstract:
  At time $t$ after an initial quench, an aging system responds to a
perturbation turned on at time $ t_{\rm w} < t$ in a way mainly depending on
the number of intermittent energy fluctuations, so-called quakes, which fall
within the observation interval $(t_{\rm w},t]$ [Sibani et al. Phys. Rev. B,
74, 224407 and Eur. J. of Physics B, 58,483-491, 2007]. The temporal
distribution of the quakes implies a functional dependence of the average
response on the ratio $t/t_{\rm w}$. Further insight is obtained imposing small
temperature steps, so-called $T$-shifts. The average response as a function of
$t/t_{\rm w,eff}$, where $t_{\rm w,eff}$ is the effective age, is similar to
the response of a system aged isothermally at the final temperature. Using an
Ising model with plaquette interactions, the applicability of analytic formulae
for the average isothermal magnetization is confirmed. The $T$-shifted aging
behavior of the model is described using effective ages. Large positive shifts
nearly reset the effective age. Negative $T$-shifts offer a more detailed probe
of the dynamics. Assuming the marginal stability of the `current' attractor
against thermal noise fluctuations, the scaling form $t_{\rm w,eff} = t_{\rm
w}^x$, and the dependence of the exponent $x$ on the aging temperatures before
and after the shift are theoretically available. The predicted form of $x$ has
no adjustable parameters. Both the algebraic scaling of the effective age and
the form of the exponent agree with the data. The simulations thus confirm the
crucial r\^{o}le of marginal stability in glassy relaxation.


title: Petri map for rank two bundles with canonical determinant

abstract:
  We prove the Bertram-Feinberg-Mukai conjecture for a generic curve $C$ of
genus $g$ and a semistable vector bundle $E$ of rank two and determinant $K$ on
$C$, namely we prove the injectivity of the Petri-canonical map $S^2(H^0(E))\to
H^0(S^2(E))$.