title:
The Impact of Simulations in Cosmology and Galaxy Formation A summary of
  the Workshop NOVICOSMO 2008

abstract:
  In the study of the process of cosmic structure formation numerical
simulations are crucial tools to interface observational data to theoretical
models and to investigate issues otherwise unexplored. Enormous advances have
been achieved in the last years thanks to the availability of sophisticated
codes, now allowing to tackle the problem of cosmic structure formation and
subsequent evolution by covering larger and larger dynamical ranges. Moreover,
computational cosmology is the ideal interpretative framework for the
overwhelming amount of new data from extragalactic surveys and from large
sample of individual objects. The Workshop Novicosmo 2008 "The Impact of
Simulations in Cosmology and Galaxy Formation' held in SISSA was aimed at
providing the state-of-the-art on the latest numerical simulations in Cosmology
and in Galaxy Formation. Particular emphasis was given to the implementation of
new physical processes in simulation codes, to the comparison between different
codes and numerical schemes and how to use best supercomputing facilities of
the next generation. Finally, the impact on our knowledge on the Physics of the
Universe brought by this new channel of investigation has also been focused.
The Workshop was divided in three sections corresponding (roughly) to three
main areas of study: Reionization and Intergalactic medium; Dark and Luminous
matter in galaxies; Clusters of galaxies and Large scale Structures. This paper
will provide i) a short resume' of the scientific results of the Workshop ii)
the complete list of the talks and the instructions on how to retrieve the .pdf
of the related (powerpoint) presentations iii) a brief presentation of the
associated Exhibition "Space Art"


title: On the spectrum of closed k=2 flux tubes in D=2+1 SU(N) gauge theories

abstract:
  We calculate the energy spectrum of a k=2 flux tube that is closed around a
spatial torus, as a function of its length l. We do so for SU(4) and SU(5)
gauge theories in 2 space dimensions. We find that to a very good approximation
the eigenstates belong to the irreducible representations of the SU(N) group
rather than just to its center, Z_N. We obtain convincing evidence that the
low-lying states are, for l not too small, very close to those of the
Nambu-Goto free string theory (in flat space-time). The correction terms appear
to be typically of O(1) in appropriate units, much as one would expect if the
bosonic string model were an effective string theory for the dynamics of these
flux tubes. This is in marked contrast to the case of fundamental flux tubes
where such corrections have been found to be unnaturally small. Moreover we
find that these corrections appear to be particularly small when the `phonons'
along the string have the same momentum, and large when their momentum is
opposite. This provides information about the detailed nature of the
interactions in the effective string theory. We have searched for, but not
found, extra states that would arise from the excitation of the massive modes
presumably associated with the non-trivial structure of the flux tube.


title:
Einstein manifolds with nonnegative isotropic curvature are locally
  symmetric

abstract:
  Let (M,g) be an Einstein manifold of dimension n \geq 4 with nonnegative
isotropic curvature. We show that (M,g) is locally symmetric.


title:
Novel recoil nuclei detectors to qualify the AMANDE facility as a
  Standard for mono-energetic neutron fields

abstract:
  The AMANDE facility at IRSN-Cadarache produces mono-energetic neutron fields
from 2 keV to 20 MeV with metrological quality. To be considered as a standard
facility, characteristics of neutron field i.e fluence distribution must be
well known by a device using absolute measurements. The development of new
detector systems allowing a direct measurement of neutron energy and fluence
has started in 2006. Using the proton recoil telescope principle with the goal
of increase the efficiency, two systems with full localization are studied. A
proton recoil telescope using CMOS sensor (CMOS-RPT) is studied for
measurements at high energies and the helium 4 gaseous micro-time projection
chamber (microTPC He4) will be dedicated to the lowest energies. Simulations of
the two systems were performed with the transport Monte Carlo code MCNPX, to
choose the components and the geometry, to optimize the efficiency and
detection limits of both devices or to estimate performances expected. First
preliminary measurements realised in 2008 demonstrated the proof of principle
of these novel detectors for neutron metrology.


title:
Stability window and mass-radius relation for magnetized strange quark
  stars

abstract:
  The stability of magnetized strange quark matter (MSQM) is investigated
within the phenomenological MIT bag model, taking into account the variation of
the relevant input parameters, namely, the strange quark mass, baryon density,
magnetic field and bag parameter. We obtain that the energy per baryon
decreases as the magnetic field increases, and its minimum value at vanishing
pressure is lower than the value found for SQM. This implies that MSQM is more
stable than non-magnetized SQM. Furthermore, the stability window of MSQM is
found to be wider than the corresponding one of SQM. The mass-radius relation
for magnetized strange quark stars is also derived in this framework.


title: Self-Diffusion in 2D Dusty Plasma Liquids: Numerical Simulation Results

abstract:
  We perform Brownian dynamics simulations for studying the self-diffusion in
two-dimensional (2D) dusty plasma liquids, in terms of both mean-square
displacement and velocity autocorrelation function (VAF). Super-diffusion of
charged dust particles has been observed to be most significant at infinitely
small damping rate $\gamma$ for intermediate coupling strength, where the
long-time asymptotic behavior of VAF is found to be the product of $t^{-1}$ and
$\exp{(-\gamma t)}$. The former represents the prediction of early theories in
2D simple liquids and the latter the VAF of a free Brownian particle. This
leads to a smooth transition from super-diffusion to normal diffusion, and then
to sub-diffusion with an increase of the damping rate. These results well
explain the seemingly contradictory scattered in recent classical molecular
dynamics simulations and experiments of dusty plasmas.


title: Forward Shock Proper Motions of Kepler's Supernova Remnant

abstract:
  The X-ray structure of Kepler's supernova remnant shows a rounded shape
delineated by forward shocks. We measure proper motions of the forward shocks
on overall rims of the remnant, by using archival Chandra data taken in two
epochs with time difference of 6.09 yr. The proper motions of the forward
shocks on the northern rim are measured to be from 0.076" (+/-0.032"+/-0.016")
to 0.110" (+/-0.014"+/-0.016") per yr, while those on the rest of the rims are
measured to be from 0.150" (+/-0.017"+/-0.016") to 0.300" (+/-0.048"+/-0.016")
per yr, here the first-term errors are statistical uncertainties and the
second-term errors are systematic uncertainties. Combining the best-estimated
shock velocity of 1660+/-120 km/sec measured for Balmer-dominated filaments in
the northern and central portions of the remnant (Sankrit et al. 2005) with the
proper motions derived for the forward shocks on the northern rim, we estimate
the distance of 3.3 (2.9-4.9) kpc to the remnant. We measure the expansion
indices to be 0.47-0.82 for most of the rims. These values are consistent with
those expected in Type-Ia SN explosion models, in which the ejecta and the
circumstellar medium have power-law density profiles whose indices are 5-7 and
0-2, respectively. Also, we should note the slower expansion on the northern
rim than that on the southern rim. This is likely caused by the inhomogeneous
circumstellar medium; the density of the circumstellar medium is higher in the
north than that in the south of the remnant. The newly estimated geometric
center, around which we believe the explosion point exists, is located at about
5" offset in the north of the radio center.


title:
A Matlab Implementation of a Flat Norm Motivated Polygonal Edge Matching
  Method using a Decomposition of Boundary into Four 1-Dimensional Currents

abstract:
  We describe and provide code and examples for a polygonal edge matching
method.


title:
Integrability and the variational formulation of non-conservative
  mechanical systems

abstract:
  It is shown that one can obtain canonically-defined dynamical equations for
non-conservative mechanical systems by starting with a first variation
functional, instead of an action functional, and finding their zeroes. The
kernel of the first variation functional, as an integral functional, is a
1-form on the manifold of kinematical states, which then represents the
dynamical state of the system. If the 1-form is exact then the first variation
functional is associated with the first variation of an action functional in
the usual manner. The dynamical equations then follow from the vanishing of the
dual of the Spencer operator that acts on the dynamical state. This operator,
in turn, relates to the integrability of the kinematical states. The method is
applied to the modeling of damped oscillators.


title: Gauge coupling unification, the GUT scale, and magic fields

abstract:
  We consider field sets that do not form complete SU(5) multiplets, but
exactly preserve the one-loop MSSM prediction for $\alpha_3(M_Z)$ independently
of the value of their mass. Such fields can raise the unification scale in
different ways, through a delayed convergence of the gauge couplings, a fake
unified running below the GUT scale, or a postponed unification after a hoax
crossing at a lower scale. The $\alpha_3(M_Z)$ prediction is independent of the
mass of the new fields, while the GUT scale often is not, which allows to vary
the GUT scale. Such "magic" fields represent a useful tool in GUT model
building. For example, they can be used to fix gauge coupling unification in
certain two step breakings of the unified group, to suppress large KK
thresholds in models with extra dimensions, or they can be interpreted as
messengers of supersymmetry breaking in GMSB models.


title:
Near-degeneracy of several pairing channels in multiorbital models for
  the Fe-pnictides

abstract:
  Weak-coupling approaches to the pairing problem in the iron pnictide
superconductors have predicted a wide variety of superconducting ground states.
We argue here that this is due both to the inadequacy of certain approximations
to the effective low-energy band structure, and to the natural near-degeneracy
of different pairing channels in superconductors with many distinct Fermi
surface sheets. In particular, we review attempts to construct two-orbital
effective band models, the argument for their fundamental inconsistency with
the symmetry of these materials, and the comparison of the dynamical
susceptibilities in two- and five-orbital models. We then present results for
the magnetic properties, pairing interactions, and pairing instabilities within
a five-orbital Random Phase Approximation model. We discuss the robustness of
these results for different dopings, interaction strengths, and variations in
band structure. Within the parameter space explored, an anisotropic,
sign-changing s-wave state and a d_x2-y2 state are nearly degenerate, due to
the near nesting of Fermi surface sheets.


title: Electromagnetic corrections in eta --> 3 pi decays

abstract:
  We re-evaluate the electromagnetic corrections to eta --> 3 pi decays at
next-to-leading order in the chiral expansion, arguing that effects of order
e^2(m_u-m_d) disregarded so far are not negligible compared to other
contributions of order e^2 times a light quark mass. Despite the appearance of
the Coulomb pole in eta --> pi+ pi- pi0 and cusps in eta --> 3 pi0, the overall
corrections remain small.


title:
Probing For New Physics and Detecting non linear vacuum QED effects
  using gravitational wave interferometer antennas

abstract:
  Low energy non linear QED effects in vacuum have been predicted since 1936
and have been subject of research for many decades. Two main schemes have been
proposed for such a 'first' detection: measurements of ellipticity acquired by
a linearly polarized beam of light passing through a magnetic field and direct
light-light scattering. The study of the propagation of light through an
external field can also be used to probe for new physics such as the existence
of axion-like particles and millicharged particles. Their existence in nature
would cause the index of refraction of vacuum to be different from unity in the
presence of an external field and dependent of the polarization direction of
the light propagating. The major achievement of reaching the project
sensitivities in gravitational wave interferometers such as LIGO an VIRGO has
opened the possibility of using such instruments for the detection of QED
corrections in electrodynamics and for probing new physics at very low
energies. In this paper we discuss the difference between direct birefringence
measurements and index of refraction measurements. We propose an almost
parasitic implementation of an external magnetic field along the arms of the
VIRGO interferometer and discuss the advantage of this choice in comparison to
a previously proposed configuration based on shorter prototype interferometers
which we believe is inadequate. Considering the design sensitivity in the
strain, for the near future VIRGO+ interferometer, of $h<2\cdot10^{-23}
\frac{1}{\sqrt{\rm Hz}}$ in the range 40 Hz $- 400$ Hz leads to a variable
dipole magnet configuration at a frequency above 20 Hz such that $B^{2}D \ge
13000$ T$^{2}$m/$\sqrt{\rm Hz}$ for a `first' vacuum non linear QED detection.


title:
Cosmic rays and the magnetic field in the nearby starburst galaxy NGC
  253 I. The distribution and transport of cosmic rays

abstract:
  The diffusive and convective CR transport in NGC 253 from the disk into the
halo is investigated using the local CR bulk speed. The connection between the
CR transport and the galactic wind is outlined. We observed NGC 253 with the
VLA at lambda 6.2 cm in a mosaic with 15 pointings. The missing zero-spacing
flux density of the VLA mosaic was filled in using observations with the 100-m
Effelsberg telescope. We also obtained a new lambda 3.6 cm map from Effelsberg
observations and reproduced VLA maps at lambda 20 cm and lambda 90 cm. We find
a thin and a thick radio disk with exponential scaleheights of 0.3 kpc and 1.7
kpc at lambda 6.2 cm. The equipartition total magnetic field strength between 7
micro G and 18 micro G in the disk is remarkably high. We use the spectral
aging of the cosmic ray electrons (CREs) seen in the vertical profiles of the
spectral index to determine a lower limit for the global CR bulk speed as
(170+/-70) km/s. The linear correlation between the scaleheights and the CRE
lifetimes, as evident from the dumbbell shaped halo, requires a vertical CR
transport with a bulk speed of (300+/-30) km/s in the northeastern halo,
similar to the escape velocity of 280 km/s. This shows the presence of a "disk
wind" in NGC253. In the southwestern halo, the transport is mainly diffusive
with a diffusion coefficient of (2.0+/-0.2) 10E29 cm^2 s^-1. In the
northeastern halo, the CR transport is convective and more efficient than in
the southwestern halo. The luminous material is transported by the disk wind,
which can explain the different amounts of extra-planar HI, Halpha, and soft
X-ray emission in the two halo parts. Future low-frequency radio observations
will provide the data to analyze the vertical velocity profile of galactic
winds.


title:
The point spread function of electrons in a magnetic field, and the
  decay of the free neutron

abstract:
  Experiments in nuclear and particle physics often use magnetic fields to
guide charged reaction products to a detector. Due to their gyration in the
guide field, the particles hit the detector within an area that can be
considerably larger than the diameter of the source where the particles are
produced. This blurring of the image of the particle source on the detector
surface is described by a suitable point spread function (PSF), which is
defined as the image of a point source. We derive simple analytical expressions
for such magnetic PSFs, valid for any angular distribution of the emitted
particles that can be developed in Legendre polynomials. We investigate this
rather general problem in the context of neutron beta decay spectrometers and
study the effect of limited detector size on measured neutron decay correlation
parameters. To our surprise, insufficient detector size does not affect much
the accuracy of such measurements, even for rather large radii of gyration.
This finding can considerably simplify the layout of the respective
spectrometers.


title:
$0\nu\beta\beta$ nuclear matrix elements and the occupancy of individual
  orbits

abstract:
  The measured occupancies of valence orbits in $^{76}$Ge and $^{76}$Se are
used as a guideline for modification of the effective mean field energies that
results in better description of these quantities. With them, in combination
with the selfconsitent renormalized quasiparticle random phase approximation
(SRQRPA) method that ensures conservation of the mean particle number in the
correlated ground state, we show that the resulting $0\nu\beta\beta$ nuclear
matrix element for the $^{76}$Ge $\to$ $^{76}$Se transition is reduced by
$\sim$25% compared to the previous QRPA value, and therefore the difference
between the present approach and the interacting shell model predictions
becomes correspondingly smaller. Analogous modification of the mean field
energies for the A=82 system also results in a reduction of $0\nu\beta\beta$
matrix element for the $^{82}$Se $\to$ $^{82}$Kr transition, making it also
closer to the shell model prediction.


title: Nonlocality without nonlocality

abstract:
  Bell's theorem is purported to demonstrate the impossibility of a local
"hidden variable" theory underpinning quantum mechanics. It relies on the
well-known assumption of `locality', and also on a little-examined assumption
called `statistical independence' (SI). Violations of this assumption have
variously been thought to suggest "backward causation", a "conspiracy" on the
part of nature, or the denial of "free will". It will be shown here that these
are spurious worries, and that denial of SI simply implies nonlocal correlation
between spacelike degrees of freedom. Lorentz-invariant theories in which SI
does not hold are easily constructed: two are exhibited here. It is
conjectured, on this basis, that quantum-mechanical phenomena may be modeled by
a local theory after all.


title: Uniform Time Average Consistency of Monte Carlo Particle Filters

abstract:
  We prove that bootstrap type Monte Carlo particle filters approximate the
optimal nonlinear filter in a time average sense uniformly with respect to the
time horizon when the signal is ergodic and the particle system satisfies a
tightness property. The latter is satisfied without further assumptions when
the signal state space is compact, as well as in the noncompact setting when
the signal is geometrically ergodic and the observations satisfy additional
regularity assumptions.


title: The Trace Anomaly and Massless Scalar Degrees of Freedom in Gravity

abstract:
  The trace anomaly of quantum fields in electromagnetic or gravitational
backgrounds implies the existence of massless scalar poles in physical
amplitudes involving the stress-energy tensor. Considering first the axial
anomaly and using QED as an example, we compute the full one-loop triangle
amplitude of the fermionic stress tensor with two current vertices, <T^{mn} J^a
J^b>, and exhibit the scalar pole in this amplitude associated with the trace
anomaly, in the limit of zero electron mass m -> 0. To emphasize the infrared
aspect of the anomaly, we use a dispersive approach and show that this
amplitude and the existence of the massless scalar pole is determined
completely by its ultraviolet finite terms, together with the requirements of
Poincare invariance of the vacuum, Bose symmetry under interchange of J^a and
J^b, and vector current and stress tensor conservation. We derive a sum rule
for the appropriate positive spectral function corresponding to the
discontinuity of the triangle amplitude, showing that it becomes proportional
to delta function of k^2, and therefore contains a massless scalar intermediate
state in the conformal limit of zero electron mass. The effective action
corresponding to the trace of the triangle amplitude can be expressed in local
form by the introduction of two scalar auxiliary fields which satisfy massless
wave equations. These massless scalar degrees of freedom couple to classical
sources, contribute to gravitational scattering processes, and can have long
range gravitational effects.


title:
On-sky wide field adaptive optics correction using multiple laser guide
  stars at the MMT

abstract:
  We describe results from the first astronomical adaptive optics system to use
multiple laser guide stars, located at the 6.5-m MMT telescope in Arizona. Its
initial operational mode, ground-layer adaptive optics (GLAO), provides uniform
stellar wavefront correction within the 2 arc minute diameter laser beacon
constellation, reducing the stellar image widths by as much as 53%, from 0.70
to 0.33 arc seconds at lambda = 2.14 microns. GLAO is achieved by applying a
correction to the telescope's adaptive secondary mirror that is an average of
wavefront measurements from five laser beacons supplemented with image motion
from a faint stellar source. Optimization of the adaptive optics system in
subsequent commissioning runs will further improve correction performance where
it is predicted to deliver 0.1 to 0.2 arc second resolution in the
near-infrared during a majority of seeing conditions.


title:
On the Soft-Gluon Resummation in Top Quark Pair Production at Hadron
  Colliders

abstract:
  We uncover a contribution to the NLO/NLL threshold resummed total cross
section for top quark pair production at hadron colliders, which has not been
taken into account in earlier literature. We derive this contribution - the
difference between the singlet and octet hard (matching) coefficients - in
exact analytic form. The numerical impact of our findings on the Sudakov
resummed cross section turns out to be large, and comparable in size to the
current estimates for the theoretical uncertainty of the total cross section. A
rough estimate points toward a few percent decrease of the latter at the LHC.


title: Odderon in Gauge/String Duality

abstract:
  At high energies, elastic hadronic cross sections, such as $pp, \overline p
p, \pi^{\pm} p$, are dominated by vacuum exchange, which in leading order of
the $1/N_c$ expansion has been identified as the BFKL Pomeron or its strong AdS
dual the closed string Reggeized graviton \cite{Brower:2006ea}. However the
difference of particle anti-particle cross sections are given by a so-called
Odderon, carrying C = -1 vacuum quantum numbers identified in weak coupling
with odd numbers of exchanged gluons. Here we show that in the dual description
the Odderon is the Reggeized Kalb-Ramond field ($B_{\mu\nu}$) in the
Neveu-Schwartz sector of closed string theory. To first order in strong
coupling, the high energy contribution of Odderon is evaluated for ${\cal N} =
4$ Super Yang-Mills by a generalization of the gravity dual analysis for
Pomeron in Ref. \cite{Brower:2006ea}. The consequence of confinement on the
Odderon are estimated in the confining QCD-like $AdS^5$ hardwall model of
Polchinski and Strassler \cite{Polchinski:2001tt}.


title: Time and Reality of Worldtubes

abstract:
  In this essay, dedicated to the one hundredth anniversary of Hermann
Minkowski's talk "Space and Time", I argue that physicists should face the
issue of the reality of spacetime and worldtubes of physical objects for two
reasons. First, this issue is not a philosophical question, as some appear to
think, since the kinematical special relativistic effects would be impossible,
as will be demonstrated, if the physical objects involved in these effects did
not exist as four-dimensional worldtubes. Second, taking into account that
worldtubes are real four-dimensional objects provides an unexpected insight
into the origin of inertia, the nature of the force acting on a body supported
in a gravitational field, and possibly even the nature of quantum objects.


title: Polaritons and Pairing Phenomena in Bose--Hubbard Mixtures

abstract:
  Motivated by recent experiments on cold atomic gases in ultra high finesse
optical cavities, we consider the problem of a two-band Bose--Hubbard model
coupled to quantum light. Photoexcitation promotes carriers between the bands
and we study the non-trivial interplay between Mott insulating behavior and
superfluidity. The model displays a global U(1) X U(1) symmetry which supports
the coexistence of Mott insulating and superfluid phases, and yields a rich
phase diagram with multicritical points. This symmetry property is shared by
several other problems of current experimental interest, including
two-component Bose gases in optical lattices, and the bosonic BEC-BCS crossover
problem for atom-molecule mixtures induced by a Feshbach resonance. We
corroborate our findings by numerical simulations.


title:
Comment on "Twofold Advance in the Theoretical Understanding of
  Far-From-Equilibrium Properties of Interacting Nanostructures"

abstract:
  Boulat, Saleur and Schmitteckert (BSS) reported results on the full $I-V$
characteristics of the interacting resonant level model (IRLM) exhibiting
region with unexpected negative differential conductance (NDC). Using
time-dependent density matrix renormalization group complemented with the exact
solution performed at a special point (the self-dual point) in the parameter
space BSS have shown that at nonzero Coulomb interaction $U$ the current
flowing through the impurity level (IL) exhibits a power-law asymptotics as a
function of large applied bias voltage. Similar conclusion was earlier reached
by Doyon. Even though their results are solid and supported by both analytic
and numeric arguments, BSS concluded that "the NDC at large voltage seems a
truly nonperturbative behavior, with unclear physical origin". On the contrary,
the remarkable physics of NDC can be explained by simple physical arguments
and, as we shall show in this Comment, in certain circumstances can be
calculated in the framework of perturbation theory.


title:
Utilizing Type Ia Supernovae in a Large, Fast, Imaging Survey to
  Constrain Dark Energy

abstract:
  We study the utility of a large sample of type Ia supernovae that might be
observed in an imaging survey that rapidly scans a large fraction of the sky
for constraining dark energy. We consider information from the traditional
luminosity distance test as well as the spread in SNeIa fluxes at fixed
redshift induced by gravitational lensing. We include a treatment of
photometric redshift uncertainties in our analysis. Our primary result is that
the information contained in the mean distance moduli of SNeIa and the
dispersion among SNeIa distance moduli complement each other, breaking a
degeneracy between the present dark energy equation of state and its time
variation without the need for a high-redshift supernova sample. To address
photometric redshift uncertainties, we present dark energy constraints as a
function of the size of an external set of spectroscopically-observed SNeIa
that may be used for redshift calibration, nspec. We find that an imaging
survey can constrain the dark energy equation of state at the epoch where it is
best constrained with a 1-sigma error of sigma(wpiv)~0.03-0.09$, depending upon
various assumptions. In addition, the marginal improvement in the error
sigma(wpiv) from an increase in the spectroscopic calibration sample drops once
nspec ~ 10^3. This result is important because it is of the order of the size
of calibration samples likely to be compiled in the coming decade and because,
for samples of this size, the spectroscopic and imaging surveys individually
place comparable constraints on the dark energy equation of state. In all
cases, it is best to calibrate photometric redshifts with a set of
spectroscopically-observed SNeIa with relatively more objects at high redshift
than the parent sample of imaging SNeIa.


title: Center vortices, the functional Schrodinger equation, and CSB

abstract:
  The functional Schrodinger equation (FSE) for QCD gives a unique perspective
on generation of a gluon mass m, as required for center vortices. The FSE,
which yields a special d=3 gauge action, combined with lattice calculations
strictly in d=3 give a value for the dimensionless ratio of d=3 coupling to
mass g_3^2/m. From this we infer a reasonably accurate value for the d=4
running coupling g^2(0) in the region of low momentum where it is nearly
constant. The result, consistent with other estimates, is too low to drive
chiral symmetry breaking (CSB) for quarks in a standard gap equation that has
no explicit confinement effects. We recall and improve on old work showing that
confinement implies CSB for quarks, and consider CSB for test (that is,
quenched) Dirac fermions in the adjoint representation. Here the
previously-found value of $g^2(0)$ is large enough to drive CSB in a gap
equation, which we relate to the presence of center vortices (non-confining,
for the adjoint) and nexuses that drive fermionic zero modes. We discuss the
extension of adjoint CSB to finite temperature.


title:
Can the WIMP annihilation boost factor be boosted by the Sommerfeld
  enhancement?

abstract:
  We demonstrate that the Sommerfeld correction to CDM annihilations can be
appreciable if even a small component of the dark matter is extremely cold.
Subhalo substructure provides such a possibility given that the smallest clumps
are relatively cold and contain even colder substructure due to incomplete
phase space mixing. Leptonic channels can be enhanced for plausible models and
the solar neighbourhood boost required to account for PAMELA/ATIC data is
plausibly obtained, especially in the case of a few TeV mass neutralino for
which the Sommerfeld-corrected boost is found to be $\sim10^4-10^5.$ Saturation
of the Sommerfeld effect is shown to occur below $\beta\sim 10^{-4},$ thereby
constraining the range of contributing substructures to be above $\sim 10^5\rm
M_\odot.$ We find that the associated diffuse gamma ray signal from
annihilations would exceed EGRET constraints unless the channels annihilating
to heavy quarks or to gauge bosons are suppressed. The lepton channel gamma
rays are potentially detectable by the FERMI satellite, not from the inner
galaxy where substructures are tidally disrupted, but rather as a
quasi-isotropic background from the outer halo, unless the outer substructures
are much less concentrated than the inner substructures and/or the CDM density
profile out to the virial radius steepens significantly.


title: Stimulated Raman adiabatic passage analogs in classical physics

abstract:
  Stimulated Raman adiabatic passage (STIRAP) is a well established technique
for producing coherent population transfer in a three-state quantum system. We
here exploit the resemblance between the Schrodinger equation for such a
quantum system and the Newton equation of motion for a classical system
undergoing torque to discuss several classical analogs of STIRAP, notably the
motion of a moving charged particle subject to the Lorentz force of a
quasistatic magnetic field, the orientation of a magnetic moment in a slowly
varying magnetic field, the Coriolis effect and the inertial frame dragging
effect. Like STIRAP, those phenomena occur for counterintuitively ordered field
pulses and are robustly insensitive to small changes in the interaction
properties.

categories: quant-ph math-ph math.MP physics.class-ph


title:
Phase-space structure in the local dark matter distribution and its
  signature in direct detection experiments

abstract:
  We study predictions for dark matter phase-space structure near the Sun based
on high-resolution simulations of six galaxy halos taken from the Aquarius
Project. The local DM density distribution is predicted to be remarkably
smooth; the density at the Sun differs from the mean over a best-fit
ellipsoidal equidensity contour by less than 15% at the 99.9% confidence level.
The local velocity distribution is also very smooth, but it differs
systematically from a (multivariate) Gaussian distribution. This is not due to
the presence of individual clumps or streams, but to broad features in the
velocity modulus and energy distributions that are stable both in space and
time and reflect the detailed assembly history of each halo. These features
have a significant impact on the signals predicted for WIMP and axion searches.
For example, WIMP recoil rates can deviate by ~10% from those expected from the
best-fit multivariate Gaussian models. The axion spectra in our simulations
typically peak at lower frequencies than in the case of multivariate Gaussian
velocity distributions. Also in this case, the spectra show significant
imprints of the formation of the halo. This implies that once direct DM
detection has become routine, features in the detector signal will allow us to
study the dark matter assembly history of the Milky Way. A new field, "dark
matter astronomy", will then emerge.


title:
Diagnoses to unravel secular hydrodynamical processes in rotating main
  sequence stars

abstract:
  (Abridged) We present a detailed analysis of the main physical processes
responsible for the transport of angular momentum and chemical species in the
radiative regions of rotating stars. We focus on cases where meridional
circulation and shear-induced turbulence only are included in the simulations.
Our analysis is based on a 2-D representation of the secular hydrodynamics,
which is treated using expansions in spherical harmonics. We present a full
reconstruction of the meridional circulation and of the associated fluctuations
of temperature and mean molecular weight along with diagnosis for the transport
of angular momentum, heat and chemicals. In the present paper these tools are
used to validate the analysis of two main sequence stellar models of 1.5 and 20
Msun for which the hydrodynamics has been previously extensively studied in the
literature. We obtain a clear visualization and a precise estimation of the
different terms entering the angular momentum and heat transport equations in
radiative zones. This enables us to corroborate the main results obtained over
the past decade by Zahn, Maeder, and collaborators concerning the secular
hydrodynamics of such objects. We focus on the meridional circulation driven by
angular momentum losses and structural readjustements. We confirm
quantitatively for the first time through detailed computations and separation
of the various components that the advection of entropy by this circulation is
very well balanced by the barotropic effects and the thermal relaxation during
most of the main sequence evolution. This enables us to derive simplifications
for the thermal relaxation on this phase. The meridional currents in turn
advect heat and generate temperature fluctuations that induce differential
rotation through thermal wind thus closing the transport loop.


title:
Young L Dwarfs Identified in the Field: A Preliminary Low-Gravity,
  Optical Spectral Sequence from L0 to L5

abstract:
  We present an analysis of 23 L dwarfs whose optical spectra display unusual
features. Twenty-one were uncovered during our search for nearby, late-type
objects using the Two Micron All-Sky Survey while two were identified in the
literature. The unusual spectral features, notably weak FeH molecular
absorption and weak Na I and K I doublets, are attributable to low-gravity and
indicate that these L dwarfs are young, low-mass brown dwarfs. We use these
data to expand the spectral classification scheme for L0 to L5-type dwarfs to
include three gravity classes. Most of the low-gravity L dwarfs have southerly
declinations and distance estimates within 60 pc. Their implied youth, on-sky
distribution, and distances suggest that they are members of nearby,
intermediate-age (~10-100 Myr), loose associations such as the Beta Pictoris
moving group, the Tucana/Horologium association, and the AB Doradus moving
group. At an age of 30 Myr and with effective temperatures from 1500 to 2400 K,
evolutionary models predict masses of 11-30 M_Jupiter for these objects. One
object, 2M 0355+11, with J-K_s=2.52+/-0.03, is the reddest L dwarf found in the
field and its late spectral type and spectral features indicative of a very low
gravity suggest it might also be the lowest-mass field L dwarf. However, before
ages and masses can be confidently adopted for any of these low-gravity L
dwarfs, additional kinematic observations are needed to confirm cluster
membership.


title:
On the Time Variability of Geometrically-Thin Black Hole Accretion Disks
  II: Viscosity-Induced Global Oscillation Modes in Simulated Disks

abstract:
  We examine the evolution and influence of viscosity-induced diskoseismic
modes in simulated black hole accretion disks. Understanding the origin and
behavior of such oscillations will help us to evaluate their potential role in
producing astronomically observed high-frequency quasi-periodic oscillations in
accreting black hole binary systems.
  Our simulated disks are geometrically-thin with a constant half-thickness of
five percent the radius of the innermost stable circular orbit. A
pseudo-Newtonian potential reproduces the relevant effects of general
relativity, and an alpha-model viscosity achieves angular momentum transport
and the coupling of orthogonal velocity components in an otherwise ideal
hydrodynamic numerical treatment.
  We find that our simulated viscous disks characteristically develop and
maintain trapped global mode oscillations with properties similar to those
expected of trapped g-modes and inner p-modes in a narrow range of frequencies
just below the maximum radial epicyclic frequency. Although the modes are
driven in the inner portion of the disk, they generate waves that propagate at
the trapped mode frequencies out to larger disk radii. This finding is
contrasted with the results of global magnetohydrodynamic disk simulations, in
which such oscillations are not easily identified. Such examples underscore
fundamental physical differences between accretion systems driven by the
magneto-rotational instability and those for which alpha viscosity serves as a
proxy for the physical processes that drive accretion, and we explore potential
approaches to the search for diskoseismic modes in full magnetohydrodynamic
disks.


title:
Imaging the Black Hole Silhouette of M87: Implications for Jet Formation
  and Black Hole Spin

abstract:
  The silhouette cast by the horizon of the supermassive black hole in M87 can
now be resolved with the emerging millimeter very-long baseline interferometry
(VLBI) capability. Despite being ~2000 times farther away than SgrA* (the
supermassive black hole at the center of the Milky-Way and the primary target
for horizon-scale imaging), M87's much larger black hole mass results in a
horizon angular scale roughly half that of SgrA*'s, providing another practical
target for direct imaging. However, unlike SgrA*, M87 exhibits a powerful radio
jet, providing an opportunity to study jet formation physics on horizon scales.
We employ a simple, qualitatively correct force-free jet model to explore the
expected high-resolution images of M87 at wavelengths of 1.3mm and 0.87mm
(230GHz and 345GHz), for a variety of jet parameters. We show that future VLBI
data will be able to constrain the size of the jet footprint, the jet
collimation rate, and the black hole spin. Polarization will further probe the
structure of the jet's magnetic field and its effect on the emitting gas.
Horizon-scale imaging of M87 and SgrA* will enable for the first time the
empirical exploration of the relationship between the mass and spin of a black
hole and the characteristics of the gas inflow/outflow around it.


title: Multi-Field Inflation on the Landscape

abstract:
  We examine a wide class of multi-field inflationary models based on fields
that decay or stabilize during inflation in a staggered fashion. The fields
driving assisted inflation are on flat, short stretches, before they encounter
a sharp drop; whenever a field encounters such a drop due to its slow roll
evolution, its energy is transferred to other degrees of freedom, i.e.
radiation. The rate at which fields decay is determined dynamically and it is
not a free parameter in this class of models. To compute observables, we
generalize the analytic framework of staggered inflation, allowing for more
general initial conditions and varying potentials. By searching for generic
situations arising on the landscape, we arrive at a setup involving linear or
hilltop potentials and evenly spread out initial field values. This scenario is
not more fine tuned than large-field models, despite the fact that many more
degrees of freedom are involved. Further, the $\eta$-problem can be alleviated.
  The additional decrease of the potential energy caused by the decay of fields
provides leading order contribution to observables, such as the scalar and
tensor spectral index or the tensor to scalar ratio, for which we derive
general expressions. We compare the predictions with WMAP5 constraints and find
that hilltop potentials are borderline ruled out at the $2\sigma$-level, while
linear potentials are in excellent agreement with observations. We further
comment on additional sources of gravitational waves and non-Gaussianities that
could serve as a smoking gun for staggered inflation.


title: A Strongly Coupled Fourth Generation at the LHC

abstract:
  We study extensions of the standard model with a strongly coupled fourth
generation. This occurs in models where electroweak symmetry breaking is
triggered by the condensation of at least some of the fourth-generation
fermions. With focus on the phenomenology at the LHC, we study the pair
production of fourth-generation down quarks, D4. We consider the typical masses
that could be associated with a strongly coupled fermion sector, in the range
(300--600) GeV. We show that the production and successive decay of these heavy
quarks into final states with same-sign dileptons, trileptons and four leptons,
can be easily seen above background with relatively low luminosity. On the
other hand, in order to confirm the presence of a new strong interaction
responsible for fourth-generation condensation, we study its contribution to D4
pair-production, and the potential to separate it from standard QCD-induced
heavy quark production. We show that this separation might require large
amounts of data. This is true even if it is assumed that the new interaction is
mediated by a massive colored vector boson, since its strong coupling to the
fourth generation renders its width of the order of its mass. We conclude that,
although this class of models can be falsified at early stages of the LHC
running, its confirmation would require high integrated luminosities.


title: An Effective Description of the Landscape - I

abstract:
  We study under what conditions massive fields can be "frozen" rather than
integrated out in certain four dimensional theories with global or local N=1
supersymmetry. We focus on models without gauge fields, admitting a
superpotential of the form W = W0(H) + epsilon W1(H,L), with epsilon << 1,
where H and L schematically denote the heavy and light chiral superfields. We
find that the fields H can always be frozen to constant values H0, if they
approximately correspond to supersymmetric solutions along the H directions,
independently of the form of the Kahler potential K for H and L, provided K is
sufficiently regular. In supergravity W0 is required to be of order epsilon at
the vacuum to ensure a mass hierarchy between H and L. The backreaction induced
by the breaking of supersymmetry on the heavy fields is always negligible,
leading to suppressed F^H--terms. For factorizable Kahler potentials W0 can
instead be generic. Our results imply that the common way complex structure and
dilaton moduli are stabilized, as in Phys. Rev. D 68 (2003) 046005 by Kachru et
al., for instance, is reliable to a very good accuracy, provided W0 is small
enough.


title:
Like vs. Like: Strategy and Improvements in Supernova Cosmology
  Systematics

abstract:
  Control of systematic uncertainties in the use of Type Ia supernovae as
standardized distance indicators can be achieved through contrasting subsets of
observationally-characterized, like supernovae. Essentially, like supernovae at
different redshifts reveal the cosmology, and differing supernovae at the same
redshift reveal systematics, including evolution not already corrected for by
the standardization. Here we examine the strategy for use of empirically
defined subsets to minimize the cosmological parameter risk, the quadratic sum
of the parameter uncertainty and systematic bias. We investigate the optimal
recognition of subsets within the sample and discuss some issues of
observational requirements on accurately measuring subset properties.
Neglecting like vs. like comparison (i.e. creating only a single Hubble
diagram) can cause cosmological constraints on dark energy to be biased by
1\sigma or degraded by a factor 1.6 for a total drift of 0.02 mag. Recognition
of subsets at the 0.016 mag level (relative differences) erases bias and
reduces the degradation to 2%.


title: Gross--Schoen Cycles and Dualising Sheaves

abstract:
  The aim of this paper is to study the modified diagonal cycle in the triple
product of a curve over a global field defined by Gross and Schoen. Our main
result is an identity between the height of this cycle and the
self-intersection of the relative dualising sheaf. We have some applications to
the following problems in number theory and algebraic geometry.


title: Non-degenerate colorings in the Brook's Theorem

abstract:
  Let $c\geq 2$ and $p\geq c$ be two integers. We will call a proper coloring
of the graph $G$ a \textit{$(c,p)$-nondegenerate}, if for any vertex of $G$
with degree at least $p$ there are at least $c$ vertices of different colors
adjacent to it. In our work we prove the following result, which generalizes
Brook's Theorem. Let $D\geq 3$ and $G$ be a graph without cliques on $D+1$
vertices and the degree of any vertex in this graph is not greater than $D$.
Then for every integer $c\geq 2$ there is a proper $(c,p)$-nondegenerate vertex
$D$-coloring of $G$, where $p=(c^3+8c^2+19c+6)(c+1).$ During the primary proof,
some interesting corollaries are derived.


title:
Probing Electron Correlation via Attosecond XUV Pulses in the Two-Photon
  Double Ionization of Helium

abstract:
  Recent experimental developments of high-intensity, short-pulse XUV light
sources are enhancing our ability to study electron-electron correlations. We
perform time-dependent calculations to investigate the so-called "sequential"
regime (photon energy above 54.4 eV) in the two-photon double ionization of
helium. We show that attosecond pulses allow to induce and probe angular and
energy correlations of the emitted electrons. The final momentum distribution
reveals regions dominated by the Wannier ridge break-up scenario and by
post-collision interaction.


title: Asteroseismology of chemically peculiar stars

abstract:
  Pulsational variability is observed in several types of main sequence stars
with anomalous chemical abundances. In this contribution I summarize the
relationship between pulsations and chemical peculiarities, giving special
emphasis to rapid oscillations in magnetic Ap stars. These magneto-acoustic
pulsators provide unique opportunities to study the interaction of pulsations,
chemical inhomogeneities, and strong magnetic fields. Time-series monitoring of
rapidly oscillating Ap stars using high-resolution spectrometers at large
telescopes and ultra-precise space photometry has led to a number of important
breakthroughs in our understanding of these interesting objects. Interpretation
of the roAp frequency spectra has allowed constraining fundamental stellar
parameters and probing poorly known properties of the stellar interiors. At the
same time, investigation of the pulsational wave propagation in chemically
stratified atmospheres of roAp stars has been used as a novel asteroseismic
tool to study pulsations as a function of atmospheric height and to map in
detail the horizontal structure of the magnetically-distorted p-modes.


title:
Effects of a phase transition on HBT correlations in an integrated
  Boltzmann+Hydrodynamics approach

abstract:
  A systematic study of HBT radii of pions, produced in heavy ion collisions in
the intermediate energy regime (SPS), from an integrated (3+1)d
Boltzmann+hydrodynamics approach is presented. The calculations in this hybrid
approach, incorporating an hydrodynamic stage into the Ultra-relativistic
Quantum Molecular Dynamics transport model, allow for a comparison of different
equations of state retaining the same initial conditions and final freeze-out.
The results are also compared to the pure cascade transport model calculations
in the context of the available data. Furthermore, the effect of different
treatments of the hydrodynamic freeze-out procedure on the HBT radii are
investigated. It is found that the HBT radii are essentially insensitive to the
details of the freeze-out prescription as long as the final hadronic
interactions in the cascade are taken into account. The HBT radii $R_L$ and
$R_O$ and the $R_O/R_S$ ratio are sensitive to the EoS that is employed during
the hydrodynamic evolution. We conclude that the increased lifetime in case of
a phase transition to a QGP (via a Bag Model equation of state) is not
supported by the available data.


title: Measuring dark energy spatial inhomogeneity with supernova data

abstract:
  The gravitational lensing distortion of distant sources by the large-scale
distribution of matter in the Universe has been extensively studied. In
contrast, very little is known about the effects due to the large-scale
distribution of dark energy. We discuss the use of Type Ia supernovae as probes
of the spatial inhomogeneity and anisotropy of dark energy. We show that a
shallow, almost all-sky survey can limit rms dark energy fluctuations at the
horizon scale down to a fractional energy density of ~10^-4


title:
Splitting and composition methods in the numerical integration of
  differential equations

abstract:
  We provide a comprehensive survey of splitting and composition methods for
the numerical integration of ordinary differential equations (ODEs). Splitting
methods constitute an appropriate choice when the vector field associated with
the ODE can be decomposed into several pieces and each of them is integrable.
This class of integrators are explicit, simple to implement and preserve
structural properties of the system. In consequence, they are specially useful
in geometric numerical integration. In addition, the numerical solution
obtained by splitting schemes can be seen as the exact solution to a perturbed
system of ODEs possessing the same geometric properties as the original system.
This backward error interpretation has direct implications for the qualitative
behavior of the numerical solution as well as for the error propagation along
time. Closely connected with splitting integrators are composition methods. We
analyze the order conditions required by a method to achieve a given order and
summarize the different families of schemes one can find in the literature.
Finally, we illustrate the main features of splitting and composition methods
on several numerical examples arising from applications.


title:
Geometrical dependence of low frequency noise in superconducting flux
  qubits

abstract:
  A general method for directly measuring the low-frequency flux noise (below
10 Hz) in compound Josephson junction superconducting flux qubits has been used
to study a series of 85 devices of varying design. The variation in flux noise
across sets of qubits with identical designs was observed to be small. However,
the levels of flux noise systematically varied between qubit designs with
strong dependence upon qubit wiring length and wiring width. Furthermore,
qubits fabricated above a superconducting ground plane yielded lower noise than
qubits without such a layer. These results support the hypothesis that
localized magnetic impurities in the vicinity of the qubit wiring are a key
source of low frequency flux noise in superconducting devices.


title: Forming a Large Disc Galaxy from a z<1 Major Merger

abstract:
  Using high resolution SPH simulations in a fully cosmological Lambda CDM
context we study the formation of a bright disk dominated galaxy that
originates from a "wet" major merger at z=0.8. The progenitors of the disk
galaxy are themselves disk galaxies that formed from early major mergers
between galaxies with blue colors. A substantial thin stellar disk grows
rapidly following the last major merger and the present day properties of the
final remnant are typical of early type spiral galaxies, with an i band B/D
~0.65, a disk scale length of 7.2 kpc, g-r = 0.5 mag, an HI line width
(W_{20}/2) of 238 km/sec and total magnitude i = -22.4. The key ingredients for
the formation of a dominant stellar disk component after a major merger are: i)
substantial and rapid accretion of gas through cold flows followed at late
times by cooling of gas from the hot phase, ii) supernova feedback that is able
to partially suppress star formation during mergers and iii) relative fading of
the spheroidal component. The gas fraction of the progenitors' disks does not
exceed 25% at z<3, emphasizing that the continuous supply of gas from the local
environment plays a major role in the regrowth of disks and in keeping the
galaxies blue. The results of this simulation alleviate the problem posed for
the existence of disk galaxies by the high likelihood of interactions and
mergers for galaxy sized halos at relatively low z.


title: Quantum algorithms for algebraic problems

abstract:
  Quantum computers can execute algorithms that dramatically outperform
classical computation. As the best-known example, Shor discovered an efficient
quantum algorithm for factoring integers, whereas factoring appears to be
difficult for classical computers. Understanding what other computational
problems can be solved significantly faster using quantum algorithms is one of
the major challenges in the theory of quantum computation, and such algorithms
motivate the formidable task of building a large-scale quantum computer. This
article reviews the current state of quantum algorithms, focusing on algorithms
with superpolynomial speedup over classical computation, and in particular, on
problems with an algebraic flavor.


title: Collective states of non-abelian quasiparticles in a magnetic field

abstract:
  Motivated by the physics of the Moore-Read \nu = 1/2 state away from
half-filling, we investigate collective states of non-abelian e/4
quasiparticles in a magnetic field. We consider two types of collective states:
incompressible liquids and Wigner crystals. In the incompressible liquid case,
we construct a natural series of states which can be thought of as a
non-abelian generalization of the Laughlin states. These states are associated
with a series of hierarchical states derived from the Moore-Read state - the
simplest of which occur at filling fraction 8/17 and 7/13. Interestingly, we
find that the hierarchical states are abelian even though their parent state is
non-abelian. In the Wigner crystal case, we construct two candidate states. We
find that they, too, are abelian - in agreement with previous analysis.


title: k-means requires exponentially many iterations even in the plane

abstract:
  The k-means algorithm is a well-known method for partitioning n points that
lie in the d-dimensional space into k clusters. Its main features are
simplicity and speed in practice. Theoretically, however, the best known upper
bound on its running time (i.e. O(n^{kd})) can be exponential in the number of
points. Recently, Arthur and Vassilvitskii [3] showed a super-polynomial
worst-case analysis, improving the best known lower bound from \Omega(n) to
2^{\Omega(\sqrt{n})} with a construction in d=\Omega(\sqrt{n}) dimensions. In
[3] they also conjectured the existence of superpolynomial lower bounds for any
d >= 2.
  Our contribution is twofold: we prove this conjecture and we improve the
lower bound, by presenting a simple construction in the plane that leads to the
exponential lower bound 2^{\Omega(n)}.


title: A Chandra X-ray view of Stephan's Quintet: Shocks and Star-formation

abstract:
  We use a deep Chandra observation to examine the structure of the hot
intra-group medium of the compact group of galaxies Stephan's Quintet. The
group is thought to be undergoing a strong dynamical interaction as an
interloper, NGC 7318b, passes through the group core at ~850 km/s. A bright
ridge of X-ray and radio continuum emission has been interpreted as the result
of shock heating, with support from observations at other wavelengths. We find
that gas in this ridge has a similar temperature (~0.6 keV) and abundance (~0.3
solar) to the surrounding diffuse emission, and that a hard emission component
is consistent with that expected from high-mass X-ray binaries associated with
star-formation in the ridge. The cooling rate of gas in the ridge is consistent
with the current star formation rate, suggesting that radiative cooling is
driving the observed star formation. The lack of a high-temperature gas
component is used to place constraints on the nature of the interaction and
shock, and we find that an oblique shock heating a pre-existing filament of HI
may be the most likely explanation of the X-ray gas in the ridge. The mass of
hot gas in the ridge is only ~2 per cent of the total mass of hot gas in the
group, which is roughly equal to the deficit in observed HI mass compared to
predictions. The hot gas component is too extended to have been heated by the
current interaction, strongly suggesting that it must have been heated during
previous dynamical encounters.


title:
Discovery of Drifting High-frequency QPOs in Global Simulations of
  Magnetic Boundary Layers

abstract:
  We report on the numerical discovery of quasi-periodic oscillations (QPOs)
associated with accretion through a non-axisymmetric magnetic boundary layer in
the unstable regime, when two ordered equatorial streams form and rotate
synchronously at approximately the angular velocity of the inner disk The
streams hit the star's surface producing hot spots. Rotation of the spots leads
to high-frequency QPOs. We performed a number of simulation runs for different
magnetospheric sizes from small to tiny, and observed a definite correlation
between the inner disk radius and the QPO frequency: the frequency is higher
when the magnetosphere is smaller. In the stable regime a small magnetosphere
forms and accretion through the usual funnel streams is observed, and the
frequency of the star is expected to dominate the lightcurve. We performed
exploratory investigations of the case in which the magnetosphere becomes
negligibly small and the disk interacts with the star through an equatorial
belt. We also performed investigation of somewhat larger magnetospheres where
one or two ordered tongues may dominate over other chaotic tongues. In
application to millisecond pulsars we obtain QPO frequencies in the range of
350 Hz to 990 Hz for one spot. The frequency associated with rotation of one
spot may dominate if spots are not identical or antipodal. If the spots are
similar and antipodal then the frequencies are twice as high. We show that
variation of the accretion rate leads to drift of the QPO peak.


title:
The ubiquitous $\zeta$-function and some of its "usual" and "unusual"
  meromorphic properties

abstract:
  In this contribution we announce a complete classification and new exotic
phenomena of the meromorphic structure of $\z$-functions associated to conic
manifolds proved in \cite{KLP1}. In particular, we show that the meromorphic
extensions of these $\z$-functions have, in general, countably many logarithmic
branch cuts on the nonpositive real axis and unusual locations of poles with
arbitrarily large multiplicity. Moreover, we give a precise
algebraic-combinatorial formula to compute the coefficients of the leading
order terms of the singularities.


title: Introduccion a la Teoria de los Monopolos Magneticos

abstract:
  This is a paper with the aim of give the student a detailed calculation of
magnetic monopole's Dirac theory.


title: Delaunay Triangulations in Linear Time? (Part I)

abstract:
  We present a new and simple randomized algorithm for constructing the
Delaunay triangulation using nearest neighbor graphs for point location. Under
suitable assumptions, it runs in linear expected time for points in the plane
with polynomially bounded spread, i.e., if the ratio between the largest and
smallest pointwise distance is polynomially bounded. This also holds for point
sets with bounded spread in higher dimensions as long as the expected
complexity of the Delaunay triangulation of a sample of the points is linear in
the sample size.


title:
The Calibration of Stromgren uvby-Hbeta Photometry for Late-Type Stars
  -- a Model Atmosphere Approach

abstract:
  We aim to test the power of theoretical calibrations based on a new
generation of MARCS models by comparisons with observational photomteric data.
We calculate synthetic uvby-Hbeta colour indices from synthetic spectra. A
sample of 388 field stars as well as stars in globular clusters is used for a
direct comparison of the synthetic indices versus empirical data and for
scrutinizing the possibilities of theoretical calibrations for temperature,
metallicity and gravity. We show that the temperature sensitivity of the
synthetic (b-y) colour is very close to its empirical counterpart, whereas the
temperature scale based upon Hbeta shows a slight offset. The theoretical
metallicity sensitivity of the m1 index (and for G-type stars its combination
with c1) is somewhat larger than the empirical one, based upon spectroscopic
determinations. The gravity sensitivity of the synthetic c1 index shows a
satisfactory behaviour when compared to obervations of F stars. For stars
cooler than the sun a deviation is significant in the c1-(b-y) diagram. The
theoretical calibrations of (b-y), (v-y) and c1 seem to work well for Pop II
stars and lead to effective temperatures for globular cluster stars supporting
recent claims by Korn et al. (2007) that atomic diffusion occurs in stars near
the turnoff point of NGC 6397. Synthetic colours of stellar atmospheres can
indeed be used, in many cases, to derive reliable fundamental stellar
parameters. The deviations seen when compared to observational data could be
due to incomplete linelists but are possibly also due to effects of assuming
plane-parallell or spherical geometry and LTE.


title: Approximation Algorithms for Bregman Co-clustering and Tensor Clustering

abstract:
  In the past few years powerful generalizations to the Euclidean k-means
problem have been made, such as Bregman clustering [7], co-clustering (i.e.,
simultaneous clustering of rows and columns of an input matrix) [9,18], and
tensor clustering [8,34]. Like k-means, these more general problems also suffer
from the NP-hardness of the associated optimization. Researchers have developed
approximation algorithms of varying degrees of sophistication for k-means,
k-medians, and more recently also for Bregman clustering [2]. However, there
seem to be no approximation algorithms for Bregman co- and tensor clustering.
In this paper we derive the first (to our knowledge) guaranteed methods for
these increasingly important clustering settings. Going beyond Bregman
divergences, we also prove an approximation factor for tensor clustering with
arbitrary separable metrics. Through extensive experiments we evaluate the
characteristics of our method, and show that it also has practical impact.


title:
Qualitative Properties of Local Random Invariant Manifolds for SPDEs
  with Quadratic Nonlinearity

abstract:
  The qualitative properties of local random invariant manifolds for stochastic
partial differential equations with quadratic nonlinearities and multiplicative
noise is studied by a cut off technique. By a detail estimates on the Perron
fixed point equation describing the local random invariant manifold, the
structure near a bifurcation is given.


title:
Classical Mobius-Ring Resonators Exhibit Fermion-Boson Rotational
  Symmetry

abstract:
  The behavior of coupled harmonic oscillators in systems with specified
boundary conditions is typically characterized by resonances whose frequency
spectra represent harmonics according to properties of the individual
oscillators, the interactions between them, and the overall symmetry of the
system. Here it is demonstrated that classical one- and two-dimensional
radiofrequency resonators constrained to a Mobius topology are the formal
partners of cylindrical ring resonators, and specifically give rise to
half-integral harmonic excitations that are orthogonal to the integral
excitations of a ring. In particular, the half-integral harmonics are formally
invariant under rotations at a minimum of 4pi rather than 2pi radians, in
analogy to the rotational symmetry of fermions in quantum mechanics. The
results offer a pathway for discovery in other physical systems as well as the
design of novel materials and electronic instrumentation.


title:
Quantization of the Hall conductance and delocalization in ergodic
  Landau Hamiltonians

abstract:
  We prove quantization of the Hall conductance for continuous ergodic Landau
Hamiltonians under a condition on the decay of the Fermi projections. This
condition and continuity of the integrated density of states are shown to imply
continuity of the Hall conductance. In addition, we prove the existence of
delocalization near each Landau level for these two-dimensional Hamiltonians.
More precisely, we prove that for some ergodic Landau Hamiltonians there exists
an energy $E$ near each Landau level where a ``localization length'' diverges.
For the Anderson-Landau Hamiltonian we also obtain a transition between
dynamical localization and dynamical delocalization in the Landau bands, with a
minimal rate of transport, even in cases when the spectral gaps are closed.


title: Dynamics of a double pendulum with distributed mass

abstract:
  We investigate a variation of the simple double pendulum in which the two
point masses are replaced by square plates. The double square pendulum exhibits
richer behavior than the simple double pendulum and provides a convenient
demonstration of nonlinear dynamics and chaos. It is also an example of an
asymmetric compound double pendulum, which has not been studied in detail. We
obtain the equilibrium configurations and normal modes of oscillation and
derive the equations of motion, which are solved numerically to produce
Poincar\'{e} sections. We show how the behavior varies from regular motion at
low energies, to chaos at intermediate energies, and back to regular motion at
high energies. We also show that the onset of chaos occurs at a significantly
lower energy than for the simple double pendulum.


title:
Ignition of a deuterium micro-detonation with a gigavolt super marx
  generator

abstract:
  The Centurion-Halite experiment demonstrated the feasibility of igniting a
deuterium-tritium micro-explosion with an energy of not more than a few
megajoule, and the Mike test, the feasibility of a pure deuterium explosion
with an energy of more than 10^6 megajoule. In both cases the ignition energy
was supplied by a fission bomb explosive. While an energy of a few megajoule,
to be released in the time required of less than 10^-9 sec, can be supplied by
lasers and intense particle beams, this is not enough to ignite a pure
deuterium explosion. Because the deuterium-tritium reaction depends on the
availability of lithium, the non-fusion ignition of a pure deuterium fusion
reaction would be highly desirable. It is shown that this goal can conceivably
be reached with a "Super Marx Generator", where a large number of "ordinary"
Marx generators charge (magnetically insulated) fast high voltage capacitors of
a second stage Marx generator, called a "Super Marx Generator", ultimately
reaching gigavolt potentials with an energy output of 100 megajoule. An intense
10^7 Ampere-GeV proton beam drawn from a "Super Marx Generator" can ignite a
deuterium thermonuclear detonation wave in a compressed deuterium cylinder,
where the strong magnetic field of the proton beam entraps the charged fusion
reaction products inside the cylinder. In solving the stand-off problem, the
stiffness of a GeV proton beam permits to place the deuterium target at a
comparatively large distance from the wall of a cavity confining the deuterium
micro-explosion.


title:
Local Two-Photon Couplings and the J=0 Fixed Pole in Real and Virtual
  Compton Scattering

abstract:
  The local coupling of two photons to the fundamental quark currents of a
hadron gives an energy-independent contribution to the Compton amplitude
proportional to the charge squared of the struck quark, a contribution which
has no analog in hadron scattering reactions. We show that this local
contribution has a real phase and is universal, giving the same contribution
for real or virtual Compton scattering for any photon virtuality and skewness
at fixed momentum transfer squared t. The t-dependence of this J=0 fixed Regge
pole is parameterized by a yet unmeasured even charge-conjugation form factor
of the target nucleon. The t=0 limit gives an important constraint on the
dependence of the nucleon mass on the quark mass through the Weisberger
relation. We discuss how this 1/x form factor can be extracted from high energy
deeply virtual Compton scattering and examine predictions given by models of
the H generalized parton distribution.


title:
Stabilization of higher-order vortices and multi-hump solitons in media
  with synthetic nonlocal nonlinearities

abstract:
  We address the evolution of higher-order excited states, such as vortex and
multi-hump solitons, in nonlocal media with synthetic, competing focusing and
defocusing nonlinearities with different nonlocal transverse scales. We reveal
that introduction of suitable competing effects makes possible the
stabilization of vortex solitons with topological charge m>2, as well as
one-dimensional multi-hump solitons with number of humps p>4, all of which are
highly unstable in natural nonlocal materials with focusing nonlinearities.


title: Deuterium microbomb rocket propulsion

abstract:
  Large scale manned space flight within the solar system is still confronted
with the solution of two problems: 1. A propulsion system to transport large
payloads with short transit times between different planetary orbits. 2. A cost
effective lifting of large payloads into earth orbit. For the solution of the
first problem a deuterium fusion bomb propulsion system is proposed where a
thermonuclear detonation wave is ignited in a small cylindrical assembly of
deuterium with a gigavolt-multimegampere proton beam, drawn from the
magnetically insulated spacecraft acting in the ultrahigh vacuum of space as a
gigavolt capacitor. For the solution of the second problem, the ignition is
done by argon ion lasers driven by high explosives, with the lasers destroyed
in the fusion explosion and becoming part of the exhaust.


title:
Multi-Scale Morphological Analysis of SDSS DR5 Survey using the Metric
  Space Technique

abstract:
  Following novel development and adaptation of the Metric Space Technique
(MST), a multi-scale morphological analysis of the Sloan Digital Sky Survey
(SDSS) Data Release 5 (DR5) was performed. The technique was adapted to perform
a space-scale morphological analysis by filtering the galaxy point
distributions with a smoothing Gaussian function, thus giving quantitative
structural information on all size scales between 5 and 250 Mpc. The analysis
was performed on a dozen slices of a volume of space containing many newly
measured galaxies from the SDSS DR5 survey. Using the MST, observational data
were compared to galaxy samples taken from N-body simulations with current best
estimates of cosmological parameters and from random catalogs. By using the
maximal ranking method among MST output functions we also develop a way to
quantify the overall similarity of the observed samples with the simulated
samples.


title: Thermodynamics and phases in quantum gravity

abstract:
  We give an approach for studying quantum gravity effects on black hole
thermodynamics. This combines a quantum framework for gravitational collapse
with quasi-local definitions of energy and surface gravity. Our arguments
suggest that (i) the specific heat of a black hole becomes positive after a
phase transition near the Planck scale,(ii) its entropy acquires a logarithmic
correction, and (iii) the mass loss rate is modified such that Hawking
radiation stops near the Planck scale. These results are due essentially to a
realization of fundamental discreteness in quantum gravity, and are in this
sense potentially theory independent.


title:
Seebeck coefficient of thermoelectric moleculat junction:
  First-principles calculations

abstract:
  A first-principles approach is presented for the thermoelectricity in
molecular junctions formed by a single molecule contact. The study investigates
the Seebeck coefficient considering the source-drain electrodes with distinct
temperatures and chemical potentials in a three-terminal geometry junction. We
compare the Seebeck coefficient in the amino-substituted and unsubstituted
butanethiol junction and observe interesting thermoelectric properties in the
amino-substituted junction. Due to the novel states around the Fermi levels
introduced by the amino-substitution, the Seebeck coefficient could be easily
modulated by using gate voltages and biases. When the temperature in one of the
electrodes is fixed, the Seebeck coefficient varies significantly with the
temperature in the other electrode, and such dependence could be modulated by
varying the gate voltages. As the biases increase, richer features in the
Seebeck coefficient are observed, which are closely related to the transmission
functions in the vicinity of the left and right Fermi levels.


title: Laser-driven high-power X- and gamma-ray ultra-short pulse source

abstract:
  A novel ultra-bright high-intensity source of X-ray and gamma radiation is
suggested. It is based on the double Doppler effect, where a relativistic
flying mirror reflects a counter-propagating electromagnetic radiation causing
its frequency multiplication and intensification, and on the inverse double
Doppler effect, where the mirror acquires energy from an ultra-intense
co-propagating electromagnetic wave. The role of the flying mirror is played by
a high-density thin plasma slab accelerating in the radiation pressure dominant
regime. Frequencies of high harmonics generated at the flying mirror by a
relativistically strong counter-propagating radiation undergo multiplication
with the same factor as the fundamental frequency of the reflected radiation,
approximately equal to the quadruple of the square of the mirror Lorentz
factor.


title:
Magnetization Plateau of Classical Ising Model on Shastry-Sutherland
  Lattice

abstract:
  We study the magnetization for the classical antiferromagnetic Ising model on
the Shastry-Sutherland lattice using the tensor renormalization group approach.
With this method, one can probe large spin systems with little finite-size
effect. For a range of temperature and coupling constant, a single
magnetization plateau at one third of the saturation value is found. We
investigate the dependence of the plateau width on temperature and on the
strength of magnetic frustration. Furthermore, the spin configuration of the
plateau state at zero temperature is determined.


title:
Graphene magnetoresistance in a parallel magnetic field: Spin
  polarization effect

abstract:
  We develop a theory for graphene magnetotransport in the presence of carrier
spin polarization as induced, for example, by the application of an in-plane
magnetic field ($B$) parallel to the 2D graphene layer. We predict a negative
magnetoresistance $\sigma \propto B^2$ for intrinsic graphene, but for
extrinsic graphene we find a non-monotonic magnetoresistance which is positive
at lower magnetic fields (below the full spin-polarization) and negative at
very high fields (above the full spin-polarization). The conductivity of the
minority spin band $(-)$ electrons does not vanish as the minority carrier
density ($n_-$) goes to zero. The residual conductivity of $(-)$ electrons at
$n_- = 0$ is unique to graphene. We discuss experimental implications of our
theory.


title: Thermodynamics of the pion gas using the O(N) model in 1/N expansion

abstract:
  We investigate the thermodynamics of a pion gas within the O(N) model in the
1/N expansion. Using the auxiliary field technique, we compute the effective
potential up to the next-to-leading order (NLO) and show that it can be
renormalized in a temperature-independent manner. The crucial step for the
consistency of the calculation turns out to be the elimination of the auxiliary
field prior to renormalization. Subsequently, we solve the NLO gap equation for
the chiral condensate as a function of temperature both in the chiral limit and
with explicit symmetry breaking. We propose a simple semi-analytic estimate of
the NLO correction to the condensate and compare it to the exact numerical
solution. Finally, we show that in the chiral limit the chiral symmetry is
restored at finite temperature by a second-order phase transition, and
determine the critical scaling of the order parameter. We study the dependence
of the critical temperature on the renormalized coupling and find that in
contrast to the weak-coupling limit, at strong coupling the critical
temperature increases at NLO.


title: Bipartite states of low rank are almost surely entangled

abstract:
  We show that a bipartite state on a tensor product of two matrix algebras is
almost surely entangled if its rank is not greater than that of one of its
reduced density matrices.


title:
Relation between Superconducting Gap Minima and Nesting Vector in
  YNi2B2C

abstract:
  We have performed ultrahigh-resolution angle-resolved photoemission
spectroscopy to directly observe the large superconducting (SC) gap anisotropy
(GA) of YNi2B2C. The result shows large SC GA with a smooth variation along an
intersection of a Fermi surface (FS) around the $\Gamma$-Z line and nearly
isotropic SC gap values for two intersections of FSs around the X-P line but
with a point-like non-zero minimum only for one sheet. The point-like SC gap
minimum can be connected by the nesting vector reported from band calculations.
The results show unexpectedly complicated SC GA of borocarbide superconductors.


title:
Classical and Quantum Transport Through Entropic Barriers Modelled by
  Hardwall Hyperboloidal Constrictions

abstract:
  We study the quantum transport through entropic barriers induced by hardwall
constrictions of hyperboloidal shape in two and three spatial dimensions. Using
the separability of the Schrodinger equation and the classical equations of
motion for these geometries we study in detail the quantum transmission
probabilities and the associated quantum resonances, and relate them to the
classical phase structures which govern the transport through the
constrictions. These classical phase structures are compared to the analogous
structures which, as has been shown only recently, govern reaction type
dynamics in smooth systems. Although the systems studied in this paper are
special due their separability they can be taken as a guide to study entropic
barriers resulting from constriction geometries that lead to non-separable
dynamics.


title:
Nuclear constraints on gravitational waves from rapidly rotating neutron
  stars

abstract:
  Gravitational waves are tiny disturbances in space-time and are a
fundamental, although not yet directly confirmed, prediction of General
Relativity. Rapidly rotating neutron stars are one of the possible sources of
gravitational radiation dependent upon pulsar's rotational frequency, details
of the equation of state of stellar matter, and distance to detector. Applying
an equation of state with symmetry energy constrained by recent nuclear
laboratory data, we set an upper limit on the strain-amplitude of gravitational
waves emitted by rapidly rotating neutron stars.


title: Weak omega-categories from intensional type theory

abstract:
  We show that for any type in Martin-L\"of Intensional Type Theory, the terms
of that type and its higher identity types form a weak omega-category in the
sense of Leinster. Precisely, we construct a contractible globular operad of
definable composition laws, and give an action of this operad on the terms of
any type and its identity types.


title:
Which infinite abelian groups admit an almost maximally almost-periodic
  group topology?

abstract:
  A topological group G is said to be almost maximally almost-periodic if its
von Neumann radical is non-trivial, but finite. In this paper, we prove that
every abelian group with an infinite torsion subgroup admits a (Hausdorff)
almost maximally almost-periodic group topology. Some open problems are also
formulated.


title: Hyperon Physics from Lattice QCD

abstract:
  I review recent lattice calculations of hyperon physics, including hyperon
spectroscopy, axial coupling constants, form factors and semileptonic decays.


title: Buchsteiner loops: associators and constructions

abstract:
  Let $Q$ be a Buchsteiner loop. We describe the associator calculus in three
variables, and show that $|Q| \ge 32$ if $Q$ is not conjugacy closed. We also
show that $|Q| \ge 64$ if there exists $x \in Q$ such that $x^2$ is not in the
nucleus of $Q$. Furthermore, we describe a general construction that yields all
proper Buchsteiner loops of order 32. Finally, we produce a Buchsteiner loop of
order 128 that is nilpotency class 3 and possesses an abelian inner mapping
group.


title: Lattice QCD with Eight Degenerate Quark Flavors

abstract:
  We report on simulations of QCD with many flavors of degenerate quarks, the
DBW2 gauge action and naive staggered fermions, using the rational hybrid Monte
Carlo algorithm. We primarily focus on eight degenerate quark flavors where a
variety of values of the coupling constant and quark mass have been used in the
simulations. The scaling behavior of the hadron spectrum and the string tension
of the heavy quark potential is studied, to probe whether the zero temperature,
continuum limit of the theory breaks chiral symmetry.


title: Odds of observing the multiverse

abstract:
  Eternal inflation predicts our observable universe lies within a bubble (or
pocket universe) embedded in a volume of inflating space. The interior of the
bubble undergoes inflation and standard cosmology, while the bubble walls
expand outward and collide with other neighboring bubbles. The collisions
provide either an opportunity to make a direct observation of the multiverse
or, if they produce unacceptable anisotropy, a threat to inflationary theory.
The probability of an observer in our bubble detecting the effects of
collisions has an absolute upper bound set by the odds of being in the part of
our bubble that lies in the forward light-cone of a collision; in the case of
collisions with bubbles of identical vacua, this bound given by the bubble
nucleation rate times ($H_{\rm{O}}/H_{\rm{I}})^2$, where $H_{\rm{O}}$ is the
Hubble scale outside the bubbles and $H_{\rm{I}}$ is the scale of the second
round of inflation that occurs inside our bubble. Similar results were obtained
by Freigovel \emph{et al.} using a different method for the case of collisions
with bubbles of much larger cosmological constant; here it is shown to hold in
the case of collisions with identical bubbles as well. A significant error in a
previous draft was corrected in order to arrive at this result.


title: Color Visualization of Blaschke Product Mappings

abstract:
  A visualization of Blaschke product mappings can be obtained by treating them
as canonical projections of covering Riemann surfaces and finding fundamental
domains and covering transformations corresponding to these surfaces. A working
tool is the technique of simultaneous continuation we introduced in previous
papers. Here, we are refining this technique for some particular types of
Blaschke products for which coloring pre-images of annuli centered at the
origin allow us to describe the mappings with a high degree of fidelity.


title: Survey of nucleon electromagnetic form factors

abstract:
  A dressed-quark core contribution to nucleon electromagnetic form factors is
calculated. It is defined by the solution of a Poincare' covariant Faddeev
equation in which dressed-quarks provide the elementary degree of freedom and
correlations between them are expressed via diquarks. The nucleon-photon vertex
involves a single parameter; i.e., a diquark charge radius. It is argued to be
commensurate with the pion's charge radius. A comprehensive analysis and
explanation of the form factors is built upon this foundation. A particular
feature of the study is a separation of form factor contributions into those
from different diagram types and correlation sectors, and subsequently a
flavour separation for each of these. Amongst the extensive body of results
that one could highlight are: r_1^{n,u}>r_1^{n,d}, owing to the presence of
axial-vector quark-quark correlations; and for both the neutron and proton the
ratio of Sachs electric and magnetic form factors possesses a zero.


title: Fermionic Molecular Dynamics for nuclear dynamics and thermodynamics

abstract:
  A new Fermionic Molecular Dynamics (FMD) model based on a Skyrme functional
is proposed in this paper. After introducing the basic formalism, some first
applications to nuclear structure and nuclear thermodynamics are presented


title: Reality - an emerging representation of the world

abstract:
  Some unique source -- the world, W -- must underlie all the information
realized in the universe throughout time. Perceived reality, R, is a
progressively emerging representation of W in the form of the geometrical
universe. Time corresponds to the process of emergence. When first represented
in R, information about W is expressed in a non-localized, quantum manner. As
the emergence proceeds, most information becomes inaccessible (entropy),
supporting the robust, redundant encoding of accessible records. The past is
encoded in and inferred from present records; the anticipated future will
preserve present information and reveal unpredictable new information about W.
Emergence of the future demands non-unitary reduction of quantum states and
increased Kolmogorov complexity of the quasi-classical records in terms of
which the quantum states are known. Given the limited information content of
records, the quasi-classical universe lacks fine details; whereas the future
must be uncertain to admit new information.


title: Cosmological constraints from 21cm surveys after reionization

abstract:
  21cm emission from residual neutral hydrogen after the epoch of reionization
can be used to trace the cosmological power spectrum of density fluctuations.
Using a Fisher matrix formulation, we provide a detailed forecast of the
constraints on cosmological parameters that are achievable with this probe. We
consider two designs: a scaled-up version of the MWA observatory as well as a
Fast Fourier Transform Telescope. We find that 21cm observations dedicated to
post-reionization redshifts may yield significantly better constraints than
next generation Cosmic Microwave Background (CMB) experiments. We find the
constraints on $\Omega_\Lambda$, $\Omega_{\rm m}h^2$, and $\Omega_\nu h^2$ to
be the strongest, each improved by at least an order of magnitude over the
Planck CMB satellite alone for both designs. Our results do not depend as
strongly on uncertainties in the astrophysics associated with the ionization of
hydrogen as similar 21cm surveys during the epoch of reionization. However, we
find that modulation of the 21cm power spectrum from the ionizing background
could potentially degrade constraints on the spectral index of the primordial
power spectrum and its running by more than an order of magnitude. Our results
also depend strongly on the maximum wavenumber of the power spectrum which can
be used due to non-linearities.


title: Metric fluctuations and decoherence

abstract:
  Recently a model of metric fluctuations has been proposed which yields an
effective Schr\"odinger equation for a quantum particle with a modified
inertial mass, leading to a violation of the weak equivalence principle. The
renormalization of the inertial mass tensor results from a local space average
over the fluctuations of the metric over a fixed background metric. Here, we
demonstrate that the metric fluctuations of this model lead to a further
physical effect, namely to an effective decoherence of the quantum particle. We
derive a quantum master equation for the particle's density matrix, discuss in
detail its dissipation and decoherence properties, and estimate the
corresponding decoherence time scales. By contrast to other models discussed in
the literature, in the present approach the metric fluctuations give rise to a
decay of the coherences in the energy representation, i. e., to a localization
in energy space.


title:
Study of the de Almeida-Thouless line using power-law diluted
  one-dimensional Ising spin glasses

abstract:
  We test for the existence of a spin-glass phase transition, the de
Almeida-Thouless line, in an externally-applied (random) magnetic field by
performing Monte Carlo simulations on a power-law diluted one-dimensional Ising
spin glass for very large system sizes. We find that an Almeida-Thouless line
only occurs in the mean field regime, which corresponds, for a short-range spin
glass, to dimension d larger than 6.


title: On the $\pd$- and $\barpd$-Operators of a Generalized Complex Structure

abstract:
  In this note, we prove that the $\pd$- and $\barpd$-operators introduced by
Gualtieri for a generalized complex structure coincide with the $\bdees$- and
$\bdel$-operators introduced by Alekseev-Xu for Evens-Lu-Weinstein modules of a
Lie bialgebroid.


title: A proximal method for composite minimization

abstract:
  We consider minimization of functions that are compositions of convex or
prox-regular functions (possibly extended-valued) with smooth vector functions.
A wide variety of important optimization problems fall into this framework. We
describe an algorithmic framework based on a subproblem constructed from a
linearized approximation to the objective and a regularization term. Properties
of local solutions of this subproblem underlie both a global convergence result
and an identification property of the active manifold containing the solution
of the original problem. Preliminary computational results on both convex and
nonconvex examples are promising.


title:
Cross-Correlation between UHECR Arrival Distribution and Large-Scale
  Structure

abstract:
  We investigate correlation between the arrival directions of
ultra-high-energy cosmic rays (UHECRs) and the large-scale structure (LSS) of
the Universe by using statistical quantities which can find the angular scale
of the correlation. The Infrared Astronomical Satellite Point Source Redshift
Survey (IRAS PSCz) catalog of galaxies is adopted for LSS. We find a positive
correlation of the highest energy events detected by the Pierre Auger
Observatory (PAO) with the IRAS galaxies inside $z=0.018$ within the angular
scale of $\sim 15^{\circ}$. This positive correlation observed in the southern
sky implies that a significant fraction of the highest energy events comes from
nearby extragalactic objects. We also analyze the data of the Akeno Giant Air
Shower Array (AGASA) which observed the northern hemisphere, but the obvious
signals of positive correlation with the galaxy distribution are not found.
Since the exposure of the AGASA is smaller than the PAO, the cross-correlation
in the northern sky should be tested using a larger number of events detected
in the future. We also discuss the correlation using the all-sky combined data
sets of both the PAO and AGASA, and find a significant correlation within $\sim
8^{\circ}$. These angular scales can constrain several models of intergalactic
magnetic field. These cross-correlation signals can be well reproduced by a
source model in which the distribution of UHECR sources is related to the IRAS
galaxies.


title: Quandle and hyperbolic volume

abstract:
  We show that the hyperbolic volume of a hyperbolic knot is a quandle cocycle
invariant. Further we show that it completely determines invertibility and
positive/negative amphicheirality of hyperbolic knots.


title: Repulsive Casimir force at zero and finite temperature

abstract:
  We study the zero and finite temperature Casimir force acting on a perfectly
conducting piston with arbitrary cross section moving inside a closed cylinder
with infinitely permeable walls. We show that at any temperature, the Casimir
force always tends to move the piston away from the walls and towards its
equilibrium position. In the case of rectangular piston, exact expressions for
the Casimir force are derived. In the high temperature regime, we show that the
leading term of the Casimir force is linear in temperature and therefore the
Casimir force has a classical limit. Due to duality, all these result also hold
for an infinitely permeable piston moving inside a closed cylinder with
perfectly conducting walls.


title: The IR Luminosity Functions of Rich Clusters

abstract:
  We present MIPS observations of the cluster A3266. About 100 spectroscopic
cluster members have been detected at 24 micron. The IR luminosity function in
A3266 is very similar to that in the Coma cluster down to the detection limit
L_IR~10^43 ergs/s, suggesting a universal form of the bright end IR LF for
local rich clusters with M~10^15 M_sun. The shape of the bright end of the
A3266-Coma composite IR LF is not significantly different from that of nearby
field galaxies, but the fraction of IR-bright galaxies (SFR > 0.2M_sun/yr) in
both clusters increases with cluster-centric radius. The decrease of the blue
galaxy fraction toward the high density cores only accounts for part of the
trend; the fraction of red galaxies with moderate SFRs (0.2 < SFR < 1 M_sun/yr)
also decreases with increasing galaxy density. These results suggest that for
the IR bright galaxies, nearby rich clusters are distinguished from the field
by a lower star-forming galaxy fraction, but not by a change in L*_IR. The
composite IR LF of Coma and A3266 shows strong evolution when compared with the
composite IR LF of two z~0.8 clusters, MS 1054 and RX J0152, with L*_IR \propto
(1+z)^{3.2+/-0.7},Phi*_IR \propto (1+z)^{1.7+/-1.0}. This L*_IR evolution is
indistinguishable from that in the field, and the Phi*_IR evolution is
stronger, but still consistent with that in the field. The similarity of the
evolution of bright-end IR LF in very different cluster and field environments
suggests either this evolution is driven by the mechanism that works in both
environments, or clusters continually replenish their star-forming galaxies
from the field, yielding an evolution in the IR LF that is similar to the
field. The mass-normalized integrated star formation rates (SFRs) of clusters
within 0.5R_200 also evolve strongly with redshift, as (1+z)^5.3.


title: Torsion and Axial Current

abstract:
  The role of torsion and a scalar field $\phi$ in gravitation, especially, in
the presence of a Dirac field in the background of a particular class of the
Riemann-Cartan geometry is considered here. Recently, a Lagrangian density with
Lagrange multipliers has been proposed by the author which has been obtained by
picking some particular terms from the SO(4,1) Pontryagin density, where the
scalar field $\phi$ causes the de Sitter connection to have the proper
dimension of a gauge field. In this formalism, conserved axial vector matter
current can be constructed, irrespective of any gauge choice, in any manifold
having arbitrary background geometry. This current is not a Noether current.


title: Photonic Feshbach Resonance

abstract:
  Hermann Feshbach predicted fifty years ago that when two atomic nuclei are
scattered within an open entrance channel-- the state observable at infinity,
they may enter an intermediate closed channel -- the locally bounded state of
the nuclei. If the energy of a bound state of in the closed channel is
fine-tuned to match the relative kinetic energy, then the open channel and the
closed channel "resonate", so that the scattering length becomes divergent. We
find that this so-called Feshbach resonance phenomenon not only exists during
the collisions of massive particles, but also emerges during the coherent
transport of massless particles, that is, photons confined in the coupled
resonator arrays \cite{lzhou08}. We implement the open and the closed channels
inside a pair of such arrays, linked by a separated cavity or a tunable qubit.
When a single photon is bounded inside the closed channel by setting the
relevant physical parameters appropriately, the vanishing transmission appears
to display this photonic Feshbach resonance. The general construction can be
implemented through various experimentally feasible solid state systems, such
as the couple defected cavities in photonic crystals. The numerical simulation
based on finite-different time-domain(FDTD) method confirms our conceive about
physical implementation.


title:
Combined approach of density functional theory and quantum Monte Carlo
  method to electron correlation in dilute magnetic semiconductors

abstract:
  We present a realistic study for electronic and magnetic properties in dilute
magnetic semiconductor (Ga,Mn)As. A multi-orbital Haldane-Anderson model
parameterized by density-functional calculations is presented and solved with
the Hirsch-Fye quantum Monte Carlo algorithm. Results well reproduce
experimental results in the dilute limit. When the chemical potential is
located between the top of the valence band and an impurity bound state, a
long-range ferromagnetic correlations between the impurities, mediated by
antiferromagnetic impurity-host couplings, are drastically developed. We
observe an anisotropic character in local density of states at the
impurity-bound-state energy, which is consistent with the STM measurements. The
presented combined approach thus offers a firm starting point for realistic
calculations of the various family of dilute magnetic semiconductors.