title: Can degenerate bound states occur in one dimensional quantum mechanics?

abstract:
  We point out that bound states, degenerate in energy but differing in parity,
may form in one dimensional quantum systems even if the potential is
non-singular in any finite domain. Such potentials are necessarily unbounded
from below at infinity and occur in several different contexts, such as in the
study of localised states in brane-world scenarios. We describe how to
construct large classes of such potentials and give explicit analytic
expressions for the degenerate bound states. Some of these bound states occur
above the potential maximum while some are below. Various unusual features of
the bound states are described and after highlighting those that are ansatz
independent, we suggest that it might be possible to observe such parity-paired
degenerate bound states in specific mesoscopic systems.


title: Multiple hits in wire chambers and other particle detectors

abstract:
  We propose an analysis of the dead time losses in counting imaging detectors
such as MWPC which can resolve $k$ simultaneous hits, and analyze in more
detail an $X-Y$ detector which has a third wire set which allows for the
recognition of simultaneous impacts.


title: Automatically Restructuring Practice Guidelines using the GEM DTD

abstract:
  This paper describes a system capable of semi-automatically filling an XML
template from free texts in the clinical domain (practice guidelines). The XML
template includes semantic information not explicitly encoded in the text
(pairs of conditions and actions/recommendations). Therefore, there is a need
to compute the exact scope of conditions over text sequences expressing the
required actions. We present a system developed for this task. We show that it
yields good performance when applied to the analysis of French practice
guidelines.


title: Generalized Jacobian Conjectures -- A purely Algebraic Approach

abstract:
  Our goal is to settle a fading problem, the Jacobian Conjecture $(JC_n)$~:
  If $f_1, \cdots, f_n$ are elements in a polynomial ring $k[X_1, \cdots, X_n]$
over a field $k$ of characteristic zero such that $ \det(\partial f_i/ \partial
X_j) $ is a nonzero constant, then $k[f_1, \cdots, f_n] = k[X_1, \cdots, X_n]$.
  Practically, what we deal with is the generalized one,
  \noindent
  The Generalized Jacobian Conjecture$(GJC)$ :{\it Let $S \hookrightarrow T$ be
an unramified homomorphism of Noetherian domains. Assume that $S$ is a simply
connected UFD ({\sl i.e.,} ${\rm Spec}(S)$ is simply connected and $S$ is a
unique factorization domain) and that $T^\times \cap S = S^\times$. Then $T =
S$.}
  In addition, for consistency of the discussion, we raise some serious (or
idiot) questions and some comments about the examples appeared in the papers
published by the certain excellent mathematicians (though we are not willing to
deal with them). However, the existence of such examples would be against our
Main Result above, so that we have to dispute in Appendix B their arguments
about the existence of their respective (so called) counter-examples. Our
conclusion is that they are not perfect counter-examples which is shown
explicitly.


title: Non adiabatic quantum search algorithms

abstract:
  We present two new continuous time quantum search algorithms similar to the
adiabatic search algorithm, but now without an adiabatic evolution. We find
that both algorithms work for a wide range of values of the parameters of the
Hamiltonian, and one of them has, as an additional feature that, for values of
time larger than a characteristic one, it will converge to a state which can be
close to the searched state.


title:
Physical Investigation of the Potentially Hazardous Asteroid (144898)
  2004 VD17

abstract:
  In this paper we present the observational campaign carried out at ESO NTT
and VLT in April and May 2006 to investigate the nature and the structure of
the Near Earth Object (144898) 2004 VD17. In spite of a great quantity of
dynamical information, according to which it will have a close approach with
the Earth in the next century, the physical properties of this asteroid are
largely unknown. We performed visible and near--infrared photometry and
spectroscopy, as well as polarimetric observations. Polarimetric and
spectroscopic data allowed us to classify 2004 VD17 as an E-type asteroid. A
good agreement was also found with the spectrum of the aubrite meteorite Mayo
Belwa. On the basis of the polarimetric albedo (p_v=0.45) and of photometric
data, we estimated a diameter of about 320 m and a rotational period of about 2
hours. The analysis of the results obtained by our complete survey have shown
that (144898) 2004 VD17 is a peculiar NEO, since it is close to the breakup
limits for fast rotator asteroids, as defined by Pravec and Harris (2000).
These results suggest that a more robust structure must be expected, as a
fractured monolith or a rubble pile in a "strength regime" (Holsapple 2002).


title:
Multimedia Content Distribution in Hybrid Wireless Networks using
  Weighted Clustering

abstract:
  Fixed infrastructured networks naturally support centralized approaches for
group management and information provisioning. Contrary to infrastructured
networks, in multi-hop ad-hoc networks each node acts as a router as well as
sender and receiver. Some applications, however, requires hierarchical
arrangements that-for practical reasons-has to be done locally and
self-organized. An additional challenge is to deal with mobility that causes
permanent network partitioning and re-organizations. Technically, these
problems can be tackled by providing additional uplinks to a backbone network,
which can be used to access resources in the Internet as well as to inter-link
multiple ad-hoc network partitions, creating a hybrid wireless network. In this
paper, we present a prototypically implemented hybrid wireless network system
optimized for multimedia content distribution. To efficiently manage the ad-hoc
communicating devices a weighted clustering algorithm is introduced. The
proposed localized algorithm deals with mobility, but does not require
geographical information or distances.


title: Localized Support for Injection Point Election in Hybrid Networks

abstract:
  Ad-hoc networks, a promising trend in wireless technology, fail to work
properly in a global setting. In most cases, self-organization and cost-free
local communication cannot compensate the need for being connected, gathering
urgent information just-in-time. Equipping mobile devices additionally with GSM
or UMTS adapters in order to communicate with arbitrary remote devices or even
a fixed network infrastructure provides an opportunity. Devices that operate as
intermediate nodes between the ad-hoc network and a reliable backbone network
are potential injection points. They allow disseminating received information
within the local neighborhood. The effectiveness of different devices to serve
as injection point differs substantially. For practical reasons the
determination of injection points should be done locally, within the ad-hoc
network partitions. We analyze different localized algorithms using at most
2-hop neighboring information. Results show that devices selected this way
spread information more efficiently through the ad-hoc network. Our results can
also be applied in order to support the election process for clusterheads in
the field of clustering mechanisms.


title: Negative forms and path space forms

abstract:
  We present an account of negative differential forms within a natural
algebraic framework of differential graded algebras, and explain their
relationship with forms on path spaces.


title: Block scaling in the directed percolation universality class

abstract:
  The universal behaviour of the directed percolation universality class is
well understood, both the critical scaling as well as finite size scaling. This
article focuses on the block (finite size) scaling of the order parameter and
its fluctuations, considering (sub-)blocks of linear size l in systems of
linear size L. The scaling depends on the choice of the ensemble, as only the
conditional ensemble produces the block-scaling behaviour as established in
equilibrium critical phenomena. The dependence on the ensemble can be
understood by an additional symmetry present in the unconditional ensemble. The
unconventional scaling found in the unconditional ensemble is a reminder of the
possibility that scaling functions themselves have a power-law dependence on
their arguments.


title:
Search for Tidal Dwarf Galaxies Candidates in a Sample of Ultraluminous
  Infrared Galaxies

abstract:
  (ABRIDGED) Star-forming small galaxies made out of collisional debris have
been found in a variety of merging systems. So far only a few of them are known
in ULIRGs although they show clear signs of interactions. Whether external star
formation may take place in such objects is an open question. The aim of this
paper is to identify and characterise the physical and kinematic properties of
the external star forming regions in a sample of ULIRGs, including TDG
candidates, using optical IFS and high angular resolution HST imaging. We have
found that the presence of external star-forming regions is common with 12
objects being identified in 5 ULIRGs. These regions show a large range of
dynamical mass up to 1x10^{10} M_sun, with average sizes of ~750 pc. In
addition, the line ratios, metallicities and H\alpha equivalent widths are
typical of young bursts of star formation (age ~ 5-8 Myr), and similar to those
of other TDG candidates. Their extinction corrected H\alpha luminosities lead
to masses for the young stellar component of ~2x10^6 - 7x10^8 M_sun. The
likelihood of survival of these regions as TDGs is discussed based on their
structural and kinematic properties. Most of these systems follow the relation
between effective radius and velocity dispersion found for globular clusters
and Ellipticals, which suggests they are stable against internal motions. The
stability against forces from the parent galaxy have been studied and a
comparison of the data with the predictions of dynamical evolutionary models is
also performed. Five regions out of twelve show High-Medium or High likelihood
of survival. Our best candidate, which satisfy all the utilized criteria, is
located in the advanced merger IRAS15250+3609 and presents a velocity field
decoupled from the relatively distant parent galaxy.


title:
Extended Theories of Gravity and their Cosmological and Astrophysical
  Applications

abstract:
  We review Extended Theories of Gravity in metric and Palatini formalism
pointing out their cosmological and astrophysical application. The aim is to
propose an alternative approach to solve the puzzles connected to dark
components.


title: Dimensional regularization and renormalization of non-commutative QFT

abstract:
  Using the recently introduced parametric representation of non-commutative
quantum field theory, we implement here the dimensional regularization and
renormalization of the vulcanized $\Phi^{\star 4}_4$ model on the Moyal space.


title: Coherent control and decoherence of charge states in quantum dots

abstract:
  This Chapter contains a review of the recent results, both experimental and
theoretical, related to optical control of carriers confined in semiconductor
quantum dots. The physics of Rabi oscillations of exciton and biexciton
occupations, as well as time-domain interference experiments are discussed.
Next, the impact of carrier--phonon interaction in a semiconductor structure is
described and modern methods of theoretical description of the carrier--phonon
kinetics and of the resulting dephasing are presented.


title: OH main line masers in the M82 starburst

abstract:
  A study of the distribution of OH gas in the central region of the nearby
active starburst galaxy M82 has confirmed two previously known bright masers
and revealed several new main line masers. Three of these are seen only at 1665
MHz, one is detected only at 1667 MHz, while the rest are detected in both
lines. Observations covering both the 1665 and 1667 MHz lines, conducted with
both the Very Large Array (VLA) and the Multi-Element Radio Linked
Interferometer Network (MERLIN), have been used to accurately measure the
positions and velocities of these features. This has allowed a comparison with
catalogued continuum features in the starburst such as HII regions and
supernova remnants, as well as known water and satellite line OH masers. Most
of the main line masers appear to be associated with known HII regions although
the two detected only at 1665 MHz are seen along the same line of sight as
known supernova remnants.


title:
Generalized analysis on $B\to K^* \rho$ within and beyond the Standard
  Model $-$ Can it help understand the $B \to K \pi$ puzzle?

abstract:
  We study $B \to K^* \rho$ modes that are analogues of the much studied $B\to
K \pi$ modes with B decaying to two vector mesons instead of pseudoscalar
mesons, using topological amplitudes in the quark diagram approach. We show how
$B \to K^*\rho$ modes can be used to obtain many more observables than those
for $B \to K \pi$ modes, even though the quark level subprocesses of both modes
are exactly the same. All the theoretical parameters (except for the weak phase
$\gamma$), such as the magnitudes of the topological amplitudes and their
strong phases, can be determined in terms of the observables without any
model-dependent assumption. We demonstrate how $B\to K^*\rho$ can also be used
to verify if there exist any relations between theoretical parameters, such as
the hierarchy relations between the topological amplitudes and possible
relations between the strong phases. Conversely, if there exist reliable
theoretical estimates of amplitudes and strong phases, the presence of New
physics could be probed. We show that if the tree and color-supressed tree are
related to the electroweak penguins and color-supressed electroweak penguins,
it is not only possible to verify the validity of such relations but also to
have a clean measurement of New Physics parameters. We also present a numerical
study to examine which of the observables are more sensitive to New Physics.


title: A taxonomic Approach to Topology Control in Ad-hoc and Wireless Networks

abstract:
  Topology Control (TC) aims at tuning the topology of highly dynamic networks
to provide better control over network resources and to increase the efficiency
of communication. Recently, many TC protocols have been proposed. The protocols
are designed for preserving connectivity, minimizing energy consumption,
maximizing the overall network coverage or network capacity. Each TC protocol
makes different assumptions about the network topology, environment detection
resources, and control capacities. This circumstance makes it extremely
difficult to comprehend the role and purpose of each protocol. To tackle this
situation, a taxonomy for TC protocols is presented throughout this paper.
Additionally, some TC protocols are classified based upon this taxonomy.


title: Global Potential Energy Minima of (H$_{2}$O)$_{n}$ Clusters on Graphite

abstract:
  Likely candidates for the global potential energy minima of (H$_{2}$O)$_{n}$
clusters with $n\leq21$ on the (0001)-surface of graphite are found using
basin-hopping global optimization. The potential energy surfaces are
constructed using the TIP4P intermolecular potentials for the water molecules
(the TIP3P is also explored as a secondary choice), a Lennard-Jones
water-graphite potential, and a water-graphite polarization potential that is
built from classical electrostatic image methods and takes into account both
the perpendicular and parallel electric polarizations of graphite. This
potential energy surface produces a rather hydrophobic water-graphite
interaction. As a consequence, the water component of the lowest
graphite-(H$_{2}$O)$_{n}$ minima is quite closely related to low-lying minima
of the corresponding TIP4P (H$_{2}$O)$_{n}$ clusters. In about half of the
cases the geometrical substructure of the water molecules in the
graphite-(H$_{2}$O)$_{n}$ global minimum coincides with that of the
corresponding free water cluster. Exceptions occur when the interaction with
graphite induces a change in geometry. A comparison of our results with
available theoretical and experimental data is performed.


title:
Phase diagram of quark-antiquark and diquark condensates at finite
  temperature and density in the 3-dimensional Gross Neveu model

abstract:
  We construct the phase diagrams of the quark-antiquark and diquark
condensates at finite temperature and density in the 3D (dimensional) 2-flavor
Gross Neveu model. We found that, in contrast to the case of the 4D Nambu
Jona-Lasinio model, there is no region where the quark-antiquark and diquark
condensates coexist. The phase diagrams obtained for some parameter region show
similar structure with the 4D QCD phase diagram.


title: Additive Regression Model for Continuous Time Processes

abstract:
  In the setting of additive regression model for continuous time process, we
establish the optimal uniform convergence rates and optimal asymptotic
quadratic error of additive regression. To build our estimate, we use the
marginal integration method.


title: Evolution of interstellar dust and stardust in the solar neighbourhood

abstract:
  The abundance evolution of interstellar dust species originating from stellar
sources and from condensation in molecular clouds in the local interstellar
medium of the Milky Way is studied and the input of dust material to the Solar
System is determined. A one-zone chemical evolution model of the Milky Way for
the elemental composition of the disk combined with an evolution model for its
interstellar dust component similar to that of Dwek (1998) is developed. The
dust model considers dust-mass return from AGB stars as calculated from
synthetic AGB models combined with models for dust condensation in stellar
outflows. Supernova dust formation is included in a simple parameterized form
which is gauged by observed abundances of presolar dust grains with supernova
origin. For dust growth in the ISM a simple method is developed for coupling
this with disk and dust evolution models. The time evolution of the abundance
of the following dust species is followed in the model: silicate, carbon,
silicon carbide, and iron dust from AGB stars and from SNe as well as silicate,
carbon, and iron dust grown in molecular clouds. It is shown that the
interstellar dust population is dominated by dust accreted in molecular clouds;
most of the dust material entering the Solar System at its formation does not
show isotopic abundance anomalies of the refractory elements, i.e.,
inconspicuous isotopic abundances do not point to a Solar System origin of dust
grains. The observed abundance ratios of presolar dust grains formed in SN
ejecta and in AGB star outflows requires that for the ejecta from SNe the
fraction of refractory elements condensed into dust is 0.15 for carbon dust and
is quite small ($\sim10^{-4}$) for other dust species.


title: Temperature and doping dependence of high-energy kink in cuprates

abstract:
  It is shown that spectral functions within the extended t-J model, evaluated
using the finite-temperature diagonalization of small clusters, exhibit the
high-energy kink in single-particle dispersion consistent with recent
angle-resolved photoemission results on hole-doped cuprates. The kink and
waterfall-like features persist up to large doping and to temperatures beyond
$J$ hence the origin can be generally attributed to strong correlations and
incoherent hole propagation at large binding energies. In contrast, our
analysis predicts that electron-doped cuprates do not exhibit these phenomena
in photoemission.


title: Regular accelerating Universe without dark energy

abstract:
  Homogeneous isotropic cosmological models with two torsion functions filled
with scalar fields and usual gravitating matter are built and investigated in
the framework of the Poincar\'e gauge theory of gravity. It is shown that by
certain restrictions on indefinite parameters of gravitational Lagrangian the
cosmological equations at asymptotics contain an effective cosmological
constant that can explain observable acceleration of cosmological expansion.
The behavior of inflationary cosmological solutions at extremely high energy
densities is analyzed, regular bouncing solutions are obtained. The role of the
space-time torsion provoking the acceleration of cosmological expansion is
discussed.


title: Deformations of Bundles and the Standard Model

abstract:
  We modify a recently proposed heterotic model hep-th/0703210, giving three
net-generations of standard model fermions, to get rid of an additional U(1)
factor in the gauge group. The method employs a stable SU(5) bundle on a
Calabi-Yau threefold admitting a free involution. The bundle has to be built as
a deformation of the direct sum of a stable SU(4) bundle and the trivial line
bundle.


title:
A one dimensional analysis of turbulence and its intermittence for the
  d-dimensional stochastic Burgers equation

abstract:
  The inviscid limit of the stochastic Burgers equation is discussed in terms
of the level surfaces of the minimising Hamilton-Jacobi function, the classical
mechanical caustic and the Maxwell set and their algebraic pre-images under the
classical mechanical flow map. The problem is analysed in terms of a reduced
(one dimensional) action function. We demonstrate that the geometry of the
caustic, level surfaces and Maxwell set can change infinitely rapidly causing
turbulent behaviour which is stochastic in nature. The intermittence of this
turbulence is demonstrated in terms of the recurrence of two processes.


title: Anomalous diffusion of epicentres

abstract:
  The classification of earthquakes in main shocks and aftershocks by a method
recently proposed by M. Baiesi and M. Paczuski allows to the generation of a
complex network composed of clusters that group the most correlated events. The
spatial distribution of epicentres inside these structures corresponding to the
catalogue of earthquakes in the eastern region of Cuba shows anomalous
anti-diffusive behaviour evidencing the attractive nature of the main shock and
the possible description in terms of fractional kinetics.


title: Some Uniform Limit Results in Additive Regression Model

abstract:
  We establish some uniform limit results in the setting of additive regression
model estimation. Our results allow to give an asymptotic 100% confidence bands
for these components. These results are stated in the framework of i.i.d random
vectors when the marginal integration estimation method is used.


title:
The multiple viewpoints as approach to information retrieval within
  collaborative development context

abstract:
  Nowadays, to achieve competitive advantage, the industrial companies are
considering that success is sustained to great product development. That is to
manage the product throughout its entire lifecycle. Achieving this goal
requires a tight collaboration between actors from a wide variety of domains,
using different software tools producing various product data types and
formats. The actors' collaboration is mainly based on the exchange /share
product information. The representation of the actors' viewpoints is the
underlying requirement of the collaborative product development. The multiple
viewpoints approach was designed to provide an organizational framework
following the actors' perspectives in the collaboration, and their
relationships. The approach acknowledges the inevitability of multiple
integration of product information as different views, promotes gathering of
actors' interest, and encourages retrieved adequate information while providing
support for integration through PLM and/or SCM collaboration. In this paper, a
multiple viewpoints representation is proposed. The product, process,
organization information models are discussed. A series of issues referring to
the viewpoints representation are discussed in detail. Based on XML standard,
taking electrical connector as an example, an application case of part of
product information modeling is stated.


title: AdS/CFT Correspondence as a Consequence of Scale Invariance

abstract:
  We study an anisotropic scale transformation in the worldsheet description of
D3-branes in Type IIB theory, and show that the transformation is really a
symmetry in a region near D3-branes. AdS/CFT correspondence follows from this
symmetry. We will explicitly show that Wilson loops in N=4 supersymmetric
Yang-Mills theory and minimal surfaces in AdS_5 are related by the symmetry.
The functional form of a supersymmetric Wilson loop operator is naturally
derived from our worldsheet point of view.


title: Local Charged States in La_{0.89}Sr_{0.11}MnO_3 Single Crystals

abstract:
  We report the direct evidence of the possibility of charge segregation in
manganites. The high contrast of electric-field-induced local charged states is
observed during more than 100 hours at room temperature. These induced states
display a piezoelectric response and polar properties. This effect may be an
example of a new kind of polar ordering in solid state.


title:
On the existence of two-dimensional nonlinear steady states in plane
  Couette flow

abstract:
  The problem of two-dimensional steady nonlinear dynamics in plane Couette
flow is revisited using homotopy from either plane Poiseuille flow or from
plane Couette flow perturbed by a small symmetry-preserving identity operator.
Our results show that it is not possible to obtain the nonlinear plane Couette
flow solutions reported by Cherhabili and Ehrenstein [Eur. J. Mech. B/Fluids,
14, 667 (1995)] using their Poiseuille-Couette homotopy. We also demonstrate
that the steady solutions obtained by Mehta and Healey [Phys. Fluids, 17, 4108
(2005)] for small symmetry-preserving perturbations are influenced by an
artefact of the modified system of equations used in their paper. However,
using a modified version of their model does not help to find plane Couette
flow solution in the limit of vanishing symmetry-preserving perturbations
either. The issue of the existence of two-dimensional nonlinear steady states
in plane Couette flow remains unsettled.


title: The Liu-Yau mass as a good quasi-local energy in general relativity

abstract:
  A quasi-local mass has been a long sought after quantity in general
relativity. A recent candidate has been the Liu-Yau mass. One can show that the
Liu-Yau mass of any two-surface is the maximum of the Brown-York energy for
that two-surface. This means that it has significant disadvantages as a mass.
It is much better interpreted as an energy and I will show one way of doing so.
The Liu-Yau mass is especially interesting in spherical geometries, where mass
and energy are indistinguishable. For a spherical two-surface, it equals the
minimum of the amount of energy at rest that one needs to put inside the
two-surface to generate the given surface geometry. Thus it gives interesting
information about the interior, something no other mass or energy function
does.


title: Extremal black holes in D=5: SUSY vs. Gauss-Bonnet corrections

abstract:
  We analyse near-horizon solutions and compare the results for the black hole
entropy of five-dimensional spherically symmetric extremal black holes when the
N=2 SUGRA actions are supplied with two different types of higher-order
corrections: (1) supersymmetric completion of gravitational Chern-Simons term,
and (2) Gauss-Bonnet term. We show that for large BPS black holes lowest order
\alpha' corrections to the entropy are the same, but for non-BPS are generally
different. We pay special attention to the class of prepotentials connected
with K3\times T^2 and T^6 compactifications. For supersymmetric correction we
find beside BPS also a set of non-BPS solutions. In the particular case of T^6
compactification (equivalent to the heterotic string on $T^4\times S^1$) we
find the (almost) complete set of solutions (with exception of some non-BPS
small black holes), and show that entropy of small black holes is different
from statistical entropy obtained by counting of microstates of heterotic
string theory. We also find complete set of solutions for K3\times T^2 and T^6
case when correction is given by Gauss-Bonnet term. Contrary to
four-dimensional case, obtained entropy is different from the one with
supersymmetric correction. We show that in Gauss-Bonnet case entropy of small
``BPS'' black holes agrees with microscopic entropy in the known cases.


title:
Suzaku Observations of Active Galactic Nuclei Detected in the Swift/BAT
  Survey: Discovery of "New Type" of Buried Supermassive Black Holes

abstract:
  We present the Suzaku broad band observations of two AGNs detected by the
Swift/BAT hard X-ray (>15 keV) survey that did not have previous X-ray data,
Swift J0601.9-8636 and Swift J0138.6-4001. The Suzaku spectra reveals in both
objects a heavily absorbed power law component with a column density of NH =~
10^{23.5-24} cm^{-2} that dominates above 10 keV, and an intense reflection
component with a solid angle >~ $2\pi$ from a cold, optically thick medium. We
find that these AGNs have an extremely small fraction of scattered light from
the nucleus, <~ 0.5% with respect to the intrinsic power law component. This
indicates that they are buried in a very geometrically-thick torus with a small
opening angle and/or have unusually small amount of gas responsible for
scattering. In the former case, the geometry of Swift J0601.9-8636 should be
nearly face-on as inferred from the small absorption for the reflection
component. The discovery of two such objects in this small sample implies that
there must be a significant number of yet unrecognized, very Compton thick AGNs
viewed at larger inclination angles in the local universe, which are difficult
to detect even in the currently most sensitive optical or hard X-ray surveys.


title: Vector Precoding for Wireless MIMO Systems: A Replica Analysis

abstract:
  We apply the replica method to analyze vector precoding, a method to reduce
transmit power in antenna array communications. The analysis applies to a very
general class of channel matrices. The statistics of the channel matrix enter
the transmitted energy per symbol via its R-transform. We find that vector
precoding performs much better for complex than for real alphabets. As a
byproduct, we find a nonlinear precoding method with polynomial complexity that
outperforms NP-hard Tomlinson-Harashima precoding for binary modulation on
complex channels if the number of transmit antennas is slightly larger than
twice the number of receive antennas.


title:
A lattice of microtraps for ultracold atoms based on patterned magnetic
  films

abstract:
  We have realized a two dimensional permanent magnetic lattice of
Ioffe-Pritchard microtraps for ultracold atoms. The lattice is formed by a
single 300 nm magnetized layer of FePt, patterned using optical lithography.
Our magnetic lattice consists of more than 15000 tightly confining microtraps
with a density of 1250 traps/mm$^2$. Simple analytical approximations for the
magnetic fields produced by the lattice are used to derive relevant trap
parameters. We load ultracold atoms into at least 30 lattice sites at a
distance of approximately 10 $\mu$m from the film surface. The present result
is an important first step towards quantum information processing with neutral
atoms in magnetic lattice potentials.


title: Intermittency on catalysts

abstract:
  The present paper provides an overview of results obtained in four recent
papers by the authors. These papers address the problem of intermittency for
the Parabolic Anderson Model in a \emph{time-dependent random medium},
describing the evolution of a ``reactant'' in the presence of a ``catalyst''.
Three examples of catalysts are considered: (1) independent simple random
walks; (2) symmetric exclusion process; (3) symmetric voter model. The focus is
on the annealed Lyapunov exponents, i.e., the exponential growth rates of the
successive moments of the reactant. It turns out that these exponents exhibit
an interesting dependence on the dimension and on the diffusion constant.


title:
Stein's method and Poisson process approximation for a class of
  Wasserstein metrics

abstract:
  Based on Stein's method, we derive upper bounds for Poisson process
approximation in the $L_1$-Wasserstein metric $d_2^{(p)}$, which is based on a
slightly adapted $L_p$-Wasserstein metric between point measures. For the case
$p=1$, this construction yields the metric $d_2$ introduced in [Barbour and
Brown Stochastic Process. Appl. 43 (1992) 9--31], for which Poisson process
approximation is well studied in the literature. We demonstrate the usefulness
of the extension to general $p$ by showing that $d_2^{(p)}$-bounds control
differences between expectations of certain $p$th order average statistics of
point processes. To illustrate the bounds obtained for Poisson process
approximation, we consider the structure of 2-runs and the hard core model as
concrete examples.


title:
A one dimensional analysis of singularities and turbulence for the
  stochastic Burgers equation in d-dimensions

abstract:
  The inviscid limit of the stochastic Burgers equation, with body forces white
noise in time, is discussed in terms of the level surfaces of the minimising
Hamilton-Jacobi function, the classical mechanical caustic and the Maxwell set
and their algebraic pre-images under the classical mechanical flow map. The
problem is analysed in terms of a reduced (one dimensional) action function. We
give an explicit expression for an algebraic surface containing the Maxwell set
and caustic in the polynomial case. Those parts of the caustic and Maxwell set
which are singular are characterised. We demonstrate how the geometry of the
caustic, level surfaces and Maxwell set can change infinitely rapidly causing
turbulent behaviour which is stochastic in nature, and we determine its
intermittence in terms of the recurrent behaviour of two processes.


title:
Asymptotic stability of solitons of the gKdV equations with general
  nonlinearity

abstract:
  We consider the generalized Korteweg-de Vries equation
  \partial_t u + \partial_x (\partial_x^2 u + f(u))=0, \quad (t,x)\in
[0,T)\times \mathbb{R}, (1)
  with general $C^3$ nonlinearity $f$. Under an explicit condition on $f$ and
$c>0$, there exists a solution in the energy space $H^1$ of (1) of the type
$u(t,x)=Q_c(x-x_0-ct)$, called soliton.
  In this paper, under general assumptions on $f$ and $Q_c$, we prove that the
family of soliton solutions around $Q_c$ is asymptotically stable in some local
sense in $H^1$, i.e. if $u(t)$ is close to $Q_{c}$ (for all $t\geq 0$), then
$u(t)$ locally converges in the energy space to some $Q_{c_+}$ as $t\to
+\infty$. Note in particular that we do not assume the stability of $Q_{c}$.
This result is based on a rigidity property of equation (1) around $Q_{c}$ in
the energy space whose proof relies on the introduction of a dual problem.
These results extend the main results in previous works devoted to the pure
power case.


title:
Two-sided optimal bounds for Green function of half-spaces for
  relativistic $\alpha$-stable process

abstract:
  The purpose of this paper is to find optimal estimates for the Green function
of a half-space of {\it the relativistic $\alpha$-stable process} with
parameter $m$ on $\Rd$ space. This process has an infinitesimal generator of
the form $mI-(m^{2/\alpha}I-\Delta)^{\alpha/2},$ where $0<\alpha<2$, $m>0$, and
reduces to the isotropic $\alpha$-stable process for $m=0$. Its potential
theory for open bounded sets has been well developed throughout the recent
years however almost nothing was known about the behaviour of the process on
unbounded sets. The present paper is intended to fill this gap and we provide
two-sided sharp estimates for the Green function for a half-space. As a
byproduct we obtain some improvements of the estimates known for bounded sets
specially for balls. The advantage of these estimates is a clarification of the
relationship between the diameter of the ball and the parameter $m$ of the
process.
  The main result states that the Green function is comparable with the Green
function for the Brownian motion if the points are away from the boundary of a
half-space and their distance is greater than one. On the other hand for the
remaining points the Green function is somehow related the Green function for
the isotropic $\alpha$-stable process. For example, for $d\ge3$, it is
comparable with the Green function for the isotropic $\alpha$-stable process,
provided that the points are close enough.


title:
Laplacian spectra of complex networks and random walks on them: Are
  scale-free architectures really important?

abstract:
  We study the Laplacian operator of an uncorrelated random network and, as an
application, consider hopping processes (diffusion, random walks, signal
propagation, etc.) on networks. We develop a strict approach to these problems.
We derive an exact closed set of integral equations, which provide the averages
of the Laplacian operator's resolvent. This enables us to describe the
propagation of a signal and random walks on the network. We show that the
determining parameter in this problem is the minimum degree $q_m$ of vertices
in the network and that the high-degree part of the degree distribution is not
that essential. The position of the lower edge of the Laplacian spectrum
$\lambda_c$ appears to be the same as in the regular Bethe lattice with the
coordination number $q_m$. Namely, $\lambda_c>0$ if $q_m>2$, and $\lambda_c=0$
if $q_m\leq2$. In both these cases the density of eigenvalues
$\rho(\lambda)\to0$ as $\lambda\to\lambda_c+0$, but the limiting behaviors near
$\lambda_c$ are very different. In terms of a distance from a starting vertex,
the hopping propagator is a steady moving Gaussian, broadening with time. This
picture qualitatively coincides with that for a regular Bethe lattice. Our
analytical results include the spectral density $\rho(\lambda)$ near
$\lambda_c$ and the long-time asymptotics of the autocorrelator and the
propagator.


title: Stochastic Loewner Evolution

abstract:
  Stochastic Loewner evolution also called Schramm Loewner evolution
(abbreviated, SLE) is a rigorous tool in mathematics and statistical physics
for generating and studying scale invariant or fractal random curves in two
dimensions. The method is based on the older deterministic Loewner evolution
introduced by Karl Loewner, who demonstrated that an arbitrary curve not
crossing itself can be generated by a real function by means of a conformal
transformation. In 2000 Oded Schramm extended this method and demonstrated that
driving the Loewner evolution by a one-dimensional Brownian motion, the curves
in the complex plane become scale invariant; the fractal dimension turns out to
be determined by the strength of the Brownian motion. SLE fills a gap in our
understanding of the critical properties of a variety of lattice models in
their scaling limits and supplements the result obtained by means of conformal
field theory. In this paper we attempt to provide a simple and heuristic
discussion of some of the important aspects of SLE.


title: Refined asymptotics around solitons for gKdV equations

abstract:
  We consider the generalized Korteweg-de Vries equation $$ \partial_t u +
\partial_x (\partial_x^2 u + f(u))=0, \quad (t,x)\in [0,T)\times \mathbb{R}$$
with general $C^2$ nonlinearity $f$. Under an explicit condition on $f$ and
$c>0$, there exists a solution in the energy space $H^1$ of the type
$u(t,x)=Q_c(x-x_0-ct)$, called soliton. Stability theory for $Q_c$ is
well-known.
  In previous works, we have proved that for $f(u)=u^p$, $p=2,3,4$, the family
of solitons is asymptotically stable in some local sense in $H^1$, i.e. if
$u(t)$ is close to $Q_{c}$ (for all $t\geq 0$), then $u(t,.+\rho(t))$ locally
converges in the energy space to some $Q_{c_+}$ as $t\to +\infty$, for some
$c^+\sim c$.
  Then, the asymptotic stability result could be extended to the case of
general assumptions on $f$ and $Q_c$.
  The objective of this paper is twofold.
  The main objective is to prove that in the case $f(u)=u^p$, $p=2,3,4$,
$\rho(t)-c_+ t$ has limit as $t\to +\infty$ under the additional assumption
$x_+ u\in L^2$.
  The second objective of this paper is to provide large time stability and
asymptotic stability results for two soliton solutions for the case of general
nonlinearity $f(u)$, when the ratio of the speeds of the solitons is small. The
motivation is to accompany forthcoming works devoted to the collision of two
solitons in the nonintegrable case. The arguments are refinements of previous
works specialized to the case $u(t)\sim Q_{c_1}+Q_{c_2}$, for $0< c_2 \ll c_1$.


title: Collaborative product and process model: Multiple Viewpoints approach

abstract:
  The design and development of complex products invariably involves many
actors who have different points of view on the problem they are addressing,
the product being developed, and the process by which it is being developed.
The actors' viewpoints approach was designed to provide an organisational
framework in which these different perspectives or points of views, and their
relationships, could be explicitly gathered and formatted (by actor activity's
focus). The approach acknowledges the inevitability of multiple interpretation
of product information as different views, promotes gathering of actors'
interests, and encourages retrieved adequate information while providing
support for integration through PLM and/or SCM collaboration. In this paper, we
present our multiple viewpoints approach, and we illustrate it by an industrial
example on cyclone vessel product.


title: Large Deviations in the Free-Energy of Mean-Field Spin-Glasses

abstract:
  We compute analytically the probability distribution of large deviations in
the spin-glass free energy for the Sherrington-Kirkpatrick mean field model,
i.e. we compute the exponentially small probability of finding a system with
intensive free energy smaller than the most likely one. This result is obtained
by computing the average value of the partition function to the power $n$ as a
function of $n$. At zero temperature this absolute prediction displays a
remarkable quantitative agreement with the numerical data.


title:
Polarization and angular distribution of the radiation emitted in
  laser-assisted recombination

abstract:
  The effect of an intense external linear polarized radiation field on the
angular distributions and polarization states of the photons emitted during the
radiative recombination is investigated. It is predicted, on symmetry grounds,
and corroborated by numerical calculations of approximate recombination rates,
that emission of elliptically polarized photons occurs when the momentum of the
electron beam is not aligned to the direction of the oscillating field.
Moreover, strong modifications to the angular distributions of the emitted
photons are induced by the external radiation field.


title:
Some estimates of the source counts at Planck Surveyor frequencies,
  using the 9C survey at 15 GHz

abstract:
  We have used multi-frequency follow-up observations of a sample of
extragalactic sources from the 9C survey at 15 GHz to make deductions about the
expected source population at higher radio frequencies, such as those in the
lower frequency bands of the Planck Surveyor satellite. In particular, we have
made empirical estimates of the source counts at 22 GHz, 30 GHz, 43 GHz and 70
GHz and compared these with both known data and current theoretical
predictions. We have also made an estimate of the count at the ALMA frequency
of 90 GHz, with a view to assessing the possible population of point sources
available for the phase calibration of that instrument.


title: Aspects of higher curvature terms and U-duality

abstract:
  We discuss various aspects of dimensional reduction of gravity with the
Einstein-Hilbert action supplemented by a lowest order deformation formed as
the Riemann tensor raised to powers two, three or four. In the case of R^2 we
give an explicit expression, and discuss the possibility of extended coset
symmetries, especially SL(n+1,Z) for reduction on an n-torus to three
dimensions. Then we start an investigation of the dimensional reduction of R^3
and R^4 by calculating some terms relevant for the coset formulation, aiming in
particular towards E_8(8)/(Spin(16)/Z_2) in three dimensions and an
investigation of the derivative structure. We emphasise some issues concerning
the need for the introduction of non-scalar automorphic forms in order to
realise certain expected enhanced symmetries.


title: The Role of Surface Plasmons in The Casimir Effect

abstract:
  In this paper we study the role of surface plasmon modes in the Casimir
effect. The Casimir energy can be written as a sum over the modes of a real
cavity and one may identify two sorts of modes, two evanescent surface plasmon
modes and propagative modes. As one of the surface plasmon modes becomes
propagative for some choice of parameters we adopt an adiabatic mode definition
where we follow this mode into the propagative sector and count it together
with the surface plasmon contribution, calling this contribution "plasmonic".
We evaluate analytically the contribution of the plasmonic modes to the Casimir
energy. Surprisingly we find that this becomes repulsive for intermediate and
large mirror separations. The contribution of surface plasmons to the Casimir
energy plays a fundamental role not only at short but also at large distances.
This suggests possibilities to taylor the Casimir force via a manipulation of
the surface plasmons properties.


title: Holographic tachyon model

abstract:
  We propose in this Letter a holographic model of tachyon dark energy. A
connection between the tachyon scalar-field and the holographic dark energy is
established, and accordingly, the potential of the holographic tachyon field is
constructed. We show that the holographic evolution of the universe with
$c\geqslant 1$ can be described completely by the resulting tachyon model in a
certain way.


title: Flavor Symmetry for Quarks and Leptons

abstract:
  Present data on neutrino masses and mixing favor the highly symmetric
tribimaximal neutrino mixing matrix which suggests an underlying flavor
symmetry. A systematic study of non-abelian finite groups of order $g \leq 31$
reveals that tribimaximal mixing can be derived not only from the well known
tetrahedral flavor symmetry $T \equiv A_4$, but also by using the binary
tetrahedral symmetry $T^{'} \equiv SL_2(F_3)$ which does not contain the
tetrahedral group as a subgroup. $T^{'}$ has the further advantage that it can
also neatly accommodate the quark masses including a heavy top quark.


title:
Gravity-like potential traps light and stretches supercontinuum in
  photonic crystal fibers

abstract:
  The use of photonic crystal fibers pumped by femtosecond pulses has enabled
the generation of broad optical supercontinua with nano-joule input energies.
This striking discovery has applications ranging from spectroscopy and
metrology to telecommunication and medicine. Amongst the physical principles
underlying supercontinuum generation are soliton fission, a variety of
four-wave mixing processes, Raman induced soliton self-frequency shift, and
dispersive wave generation mediated by solitons. Although all of the above
effects contribute to supercontinuum generation none of them can explain the
generation of blue and violet light from infrared femtosecond pump pulses,
which has been seen already in the first observations of the supercontinuum in
photonic crystal fibers. In this work we argue that the most profound role in
the shaping of the short-wavelength edge of the continuum is played by the
effect of radiation trapping in a gravity-like potential created by
accelerating solitons. The underlying physics of this effect has a
straightforward analogy with the inertial forces acting on an observer moving
with a constant acceleration.


title:
GRB 060206 and the quandary of achromatic breaks in afterglow light
  curves

abstract:
  Gamma-ray burst afterglow observations in the Swift era have a perceived lack
of achromatic jet breaks compared to the BeppoSAX era. We present our
multi-wavelength analysis of GRB 060206 as an illustrative example of how
inferences of jet breaks from optical and X-ray data might differ. The results
of temporal and spectral analyses are compared, and attempts are made to fit
the data within the context of the standard blast wave model. We find that
while the break appears more pronounced in the optical and evidence for it from
the X-ray alone is weak, the data are actually consistent with an achromatic
break at about 16 hours. This break and the light curves fit standard blast
wave models, either as a jet break or as an injection break. As the pre-Swift
sample of afterglows are dominated by optical observations, and in the Swift
era most well sampled light curves are in the X-ray, caution is needed when
making a direct comparison between the two samples, and when making definite
statements on the absence of achromatic breaks.


title:
Efficient implementation of finite volume methods in Numerical
  Relativity

abstract:
  Centered finite volume methods are considered in the context of Numerical
Relativity. A specific formulation is presented, in which third-order space
accuracy is reached by using a piecewise-linear reconstruction. This
formulation can be interpreted as an 'adaptive viscosity' modification of
centered finite difference algorithms. These points are fully confirmed by 1D
black-hole simulations. In the 3D case, evidence is found that the use of a
conformal decomposition is a key ingredient for the robustness of black hole
numerical codes.


title: All creatures great and small

abstract:
  Let kappa be an uncountable regular cardinal. Assuming 2^kappa=kappa^+, we
show that the clone lattice on a set of size kappa is not dually atomic.


title: The VLA Low-frequency Sky Survey

abstract:
  The Very Large Array (VLA) Low-frequency Sky Survey (VLSS) has imaged 95% of
the 3*pi sr of sky north of declination = -30 degrees at a frequency of 74 MHz
(4 meter wavelength). The resolution is 80" (FWHM) throughout, and the typical
RMS noise level is ~0.1 Jy/beam. The typical point-source detection limit is
0.7 Jy/beam and so far nearly 70,000 sources have been catalogued. This survey
used the 74 MHz system added to the VLA in 1998. It required new imaging
algorithms to remove the large ionospheric distortions at this very low
frequency throughout the entire ~11.9 degree field of view. This paper
describes the observation and data reduction methods used for the VLSS and
presents the survey images and source catalog. All of the calibrated images and
the source catalog are available online (http://lwa.nrl.navy.mil/VLSS) for use
by the astronomical community.


title:
A Computational Approach to Essential and Nonessential Objective
  Functions in Linear Multicriteria Optimization

abstract:
  The question of obtaining well-defined criteria for multiple criteria
decision making problems is well-known. One of the approaches dealing with this
question is the concept of nonessential objective function. A certain objective
function is called nonessential if the set of efficient solutions is the same
both with or without that objective function. In this paper we put together two
methods for determining nonessential objective functions. A computational
implementation is done using a computer algebra system.


title:
Are generalized and transverse momentum dependent parton distributions
  related ?

abstract:
  The present knowledge on non-trivial relations between generalized parton
distributions on the one hand and transverse momentum dependent distributions
on the other is reviewed. While various relations can be found in the framework
of spectator models, so far no model-independent non-trivial relations have
been established.


title: Symmetry of Planar Four-Body Convex Central Configurations

abstract:
  We study the relationship between the masses and the geometric properties of
central configurations. We prove that in the planar four-body problem, a convex
central configuration is symmetric with respect to one diagonal if and only if
the masses of the two particles on the other diagonal are equal. If these two
masses are unequal, then the less massive one is closer to the former diagonal.
Finally, we extend these results to the case of non-planar central
configurations of five particles.


title:
Valley polarization and susceptibility of composite fermions around
  nu=3/2

abstract:
  We report magnetotransport measurements of fractional quantum Hall states in
an AlAs quantum well around Landau level filling factor nu = 3/2, demonstrating
that the quasiparticles are composite Fermions (CFs) with a valley degree of
freedom. By monitoring the valley level crossings for these states as a
function of applied symmetry-breaking strain, we determine the CF valley
susceptibility and polarization. The data can be explained well by a simple
Landau level fan diagram for CFs, and are in nearly quantitative agreement with
the results reported for CF spin polarization.


title: Single Transverse-Spin Asymmetry in Hadronic Dijet Production

abstract:
  We study the single transverse-spin asymmetry for dijet production in
hadronic collisions in both the collinear QCD factorization approach and the
Brodsky-Hwang-Schmidt model. We show that a nonvanishing asymmetry is generated
by both initial-state and final-state interactions, and that the final-state
interactions dominate. We find that in the leading kinematic region where the
transverse momentum imbalance of the two jets, q_\perp = P_{1\perp}+P_{2\perp},
is much less than the momentum of either jet, the contribution from the lowest
non-trivial perturbative order to both the spin-averaged and the spin-dependent
dijet cross sections can be factorized into a hard part that is a function only
of the averaged jet momentum P_\perp = (P_{1\perp}-P_{2\perp})/2, and
perturbatively generated transverse momentum dependent (TMD) parton
distributions. We show that the spin asymmetry at this non-trivial perturbative
order can be described by the TMD parton distributions defined in either
semi-inclusive DIS or the Drell-Yan process. We derive the same hard parts from
both the collinear factorization approach and in the context of the
Brodsky-Hwang-Schmidt model, verifying that they are not sensitive to details
of the factorized long distance physics.


title: Observational Bounds on Modified Gravity Models

abstract:
  Modified gravity provides a possible explanation for the currently observed
cosmic accelaration. In this paper, we study general classes of modified
gravity models. The Einstein-Hilbert action is modified by using general
functions of the Ricci and the Gauss-Bonnet scalars, both in the metric and in
the Palatini formalisms. We do not use an explicit form for the functions, but
a general form with a valid Taylor expansion up to second order about redshift
zero in the Riemann-scalars. The coefficients of this expansion are then
reconstructed via the cosmic expansion history measured using current
cosmological observations. These are the quantities of interest for theoretical
considerations relating to ghosts and instabilities. We find that current data
provide interesting constraints on the coefficients. The next-generation dark
energy surveys should shrink the allowed parameter space for modifed gravity
models quite dramatically.


title:
Spectral plots and the representation and interpretation of biological
  data

abstract:
  It is basic question in biology and other fields to identify the char-
acteristic properties that on one hand are shared by structures from a
particular realm, like gene regulation, protein-protein interaction or neu- ral
networks or foodwebs, and that on the other hand distinguish them from other
structures. We introduce and apply a general method, based on the spectrum of
the normalized graph Laplacian, that yields repre- sentations, the spectral
plots, that allow us to find and visualize such properties systematically. We
present such visualizations for a wide range of biological networks and compare
them with those for networks derived from theoretical schemes. The differences
that we find are quite striking and suggest that the search for universal
properties of biological networks should be complemented by an understanding of
more specific features of biological organization principles at different
scales.


title:
Inertial Effects in Nonequilibrium Work Fluctuations by a Path Integral
  Approach

abstract:
  Inertial effects in fluctuations of the work to sustain a system in a
nonequilibrium steady state are discussed for a dragged massive Brownian
particle model using a path integral approach. We calculate the work
distribution function in the laboratory and comoving frames and prove the
asymptotic fluctuation theorem for these works for any initial condition.
Important and observable differences between the work fluctuations in the two
frames appear for finite times and are discussed concretely for a
nonequilibrium steady state initial condition. We also show that for finite
times a time oscillatory behavior appears in the work distribution function for
masses larger than a nonzero critical value.


title: Resolved Conifolds in Supergravity Solutions

abstract:
  We construct generalized 11D supergravity solutions of fully localized
intersecting D2/D4 brane systems. These solutions are obtained by embedding
six-dimensional resolved Eguchi-Hanson conifolds lifted to M-theory. We reduce
these solutions to ten dimensions, obtaining new D-brane systems in type IIA
supergravity. We discuss the limits in which the dynamics of the D2 brane
decouples from the bulk for these solutions.


title:
Developing a Collaborative and Autonomous Training and Learning
  Environment for Hybrid Wireless Networks

abstract:
  With larger memory capacities and the ability to link into wireless networks,
more and more students uses palmtop and handheld computers for learning
activities. However, existing software for Web-based learning is not
well-suited for such mobile devices, both due to constrained user interfaces as
well as communication effort required. A new generation of applications for the
learning domain that is explicitly designed to work on these kinds of small
mobile devices has to be developed. For this purpose, we introduce CARLA, a
cooperative learning system that is designed to act in hybrid wireless
networks. As a cooperative environment, CARLA aims at disseminating teaching
material, notes, and even components of itself through both fixed and mobile
networks to interested nodes. Due to the mobility of nodes, CARLA deals with
upcoming problems such as network partitions and synchronization of teaching
material, resource dependencies, and time constraints.


title:
On the Interpretation of the Age Distribution of Star Clusters in the
  Small Magellanic Cloud

abstract:
  We re-analyze the age distribution (dN/dt) of star clusters in the Small
Magellanic Cloud (SMC) using age determinations based on the Magellanic Cloud
Photometric Survey. For ages younger than 3x10^9 yr the dN/dt distribution can
be approximated by a power-law distribution, dN/dt propto t^-beta, with
-beta=-0.70+/-0.05 or -beta=-0.84+/-0.04, depending on the model used to derive
the ages. Predictions for a cluster population without dissolution limited by a
V-band detection result in a power-law dN/dt distribution with an index of
~-0.7. This is because the limiting cluster mass increases with age, due to
evolutionary fading of clusters, reducing the number of observed clusters at
old ages. When a mass cut well above the limiting cluster mass is applied, the
dN/dt distribution is flat up to 1 Gyr. We conclude that cluster dissolution is
of small importance in shaping the dN/dt distribution and incompleteness causes
dN/dt to decline. The reason that no (mass independent) infant mortality of
star clusters in the first ~10-20 Myr is found is explained by a detection bias
towards clusters without nebular emission, i.e. cluster that have survived the
infant mortality phase. The reason we find no evidence for tidal (mass
dependent) cluster dissolution in the first Gyr is explained by the weak tidal
field of the SMC. Our results are in sharp contrast to the interpretation of
Chandar et al. (2006), who interpret the declining dN/dt distribution as rapid
cluster dissolution. This is due to their erroneous assumption that the sample
is limited by cluster mass, rather than luminosity.


title: Black Stars and Gamma Ray Bursts

abstract:
  Stars that are collapsing toward forming a black hole but are frozen near the
Schwarzschild horizon are termed "black stars". Collisions of black stars, in
contrast to black hole collisions, may be sources of gamma ray bursts, whose
basic parameters are estimated quite simply and are found to be consistent with
observed gamma ray bursts. Black star gamma ray bursts should be preceded by
gravitational wave emission similar to that from the coalescence of black
holes.


title:
Analytical Form of Current-Voltage Characteristic of a Parallel-Plane
  Ionization Chamber

abstract:
  The elementary processes taking place in the formation of charged particles
and their flow in the ionization chamber are considered. On the basic of
particles and charges balance a differential equation describing the
distribution of current densities in the ionization chamber volume is obtained.
As a result of the differential equation solution an analytical form of the
current-voltage characteristic of a parallel-plane ionization chamber is
obtained.


title: Single particle spectrum of resonant population imbalanced Fermi gases

abstract:
  We use a T-matrix approximation to calculate the single particle spectrum of
the normal state of a gas of Fermionic atoms at low temperature.
  In the strongly interacting regime of the polarized gas, we find that the
spectrum is separated in two branches, leading to a double-peaked
radiofrequency spectral feature.


title: Constant terms in threshold resummation and the quark form factor

abstract:
  We verify to order alpha_s^4 two previously conjectured relations, valid in
four dimensions, between constant terms in threshold resummation (for Deep
Inelastic Scattering and the Drell-Yan process) and the second logarithmic
derivative of the massless quark form factor. The same relations are checked to
all orders in the large beta_0 limit; as a byproduct a dispersive
representation of the form factor is obtained. These relations allow to compute
in a symmetrical way the three-loop resummation coefficients B_3 and D_3 in
terms of the three-loop contributions to the virtual diagonal splitting
function and to the quark form factor, confirming results obtained in the
literature.


title: Effective potentials, thermodynamics, and twisted mass quarks

abstract:
  Using effective Lagrangian arguments, I explore the qualitative behavior
expected at finite temperature for two flavor lattice QCD formulated with
Wilson fermions and a twisted mass term. A rather rich phase structure is
predicted, exhibiting Aoki's parity violating phase along with a deconfinement
region forming a conical structure in the space of coupling, hopping parameter,
and twisted mass variables.


title: Soft particle model for block copolymers

abstract:
  A soft particle model for diblock (AB) copolymer melts is proposed. Each
molecule is mapped onto two soft spheres built by Gaussian A- and B-monomer
distributions. An approximate analytical expression for the joint distribution
function for the distance between both spheres and their radii of gyration is
derived, which determines the entropic contribution to the intramolecular free
energy. Adding a mean-field expression for the intermolecular interactions, we
obtain the total free energy of the system. Based on this free energy, Monte
Carlo simulations are carried out to study the kinetics of microphase ordering
in the bulk and its effect on molecular diffusion. This is followed by an
analysis of thin films with emphasis on pattern transfer from walls with a
periodic structure. It is shown that the level of coarse graining in the soft
particle model is suitable to describe structural and kinetic properties of
copolymers on mesoscopic scales.


title: Strings for Quantumchromodynamics

abstract:
  During the last ten years, intriguing dualities between gauge and string
theory have been found and explored. They provide a novel window on strongly
coupled gauge physics, including QCD-like models. Based on a short historical
review of modern string theory, we shall explain how so-called AdS/CFT
dualities emerged at the end of the 1990s. Some of their concrete implications
and remarkable recent progress are then illustrated for the simplest example,
namely the multicolor limit of \N=4 Super Yang-Mills theory in four dimensions.
We end with a few comments on existing extensions to more realistic models and
applications, in particular to strongly coupled quark gluon plasmas. This text
is meant as a non-technical introduction to gauge/string dualities for
(particle) physicists.


title:
On the equivalence between Implicit Regularization and Constrained
  Differential Renormalization

abstract:
  Constrained Differential Renormalization (CDR) and the constrained version of
Implicit Regularization (IR) are two regularization independent techniques that
do not rely on dimensional continuation of the space-time. These two methods
which have rather distinct basis have been successfully applied to several
calculations which show that they can be trusted as practical, symmetry
invariant frameworks (gauge and supersymmetry included) in perturbative
computations even beyond one-loop order.
  In this paper, we show the equivalence between these two methods at one-loop
order. We show that the configuration space rules of CDR can be mapped into the
momentum space procedures of Implicit Regularization, the major principle
behind this equivalence being the extension of the properties of regular
distributions to the regularized ones.


title:
Experimental Generation of Intrinsic Localized Modes in a discrete
  electrical transmission line

abstract:
  Experimental evidence for the generation of intrinsic localized modes (ILMs)
in a nonlinear electrical transmission line is presented both via modulational
instability (MI) of the uniform mode and via driving the lattice locally. The
spatial profiles of these modes localized on the order of the lattice spacing
can be directly measured in this macroscopic lattice, in contrast to most other
systems where ILMs have so far been detected.


title: Testing the surface detector simulation for the Pierre Auger Observatory

abstract:
  The building block of the surface detector of the Pierre Auger Observatory is
a water Cherenkov tank. The response to shower particles is simulated using a
dedicated program based on GEANT4. To check the simulation chain, we compare
the simulated signals produced by cosmic muons at various zenith angles with
experimental data from a special Cherenkov detector equipped with a muon
hodoscope. The signals from muon-decay electrons and the evolution of the
charge with water level are also studied.


title: Resumption of mass accretion in RS Oph

abstract:
  The latest outburst of the recurrent nova RS Oph occurred in 2006 February.
Photometric data presented here show evidence of the resumption of optical
flickering, indicating re-establishment of accretion by day 241 of the
outburst. Magnitude variations of up to 0.32 mag in V-band and 0.14 mag in B on
timescales of 600-7000 s are detected. Over the two week observational period
we also detect a 0.5 mag decline in the mean brightness, from V~11.4 to V~11.9,
and record B~12.9 mag. Limits on the mass accretion rate of ~10^{-10} to
10^{-9} Msun/yr are calculated, which span the range of accretion rates modeled
for direct wind accretion and Roche lobe overflow mechanisms. The current
accretion rates make it difficult for thermonuclear runaway models to explain
the observed recurrence interval, and this implies average accretion rates are
typically higher than seen immediately post-outburst.


title:
A High-Resolution Survey of Low-Redshift QSO Absorption Lines:
  Statistics and Physical Conditions of O VI Absorbers

abstract:
  Using high-resolution UV spectra of 16 low-z QSOs, we study the physical
conditions and statistics of O VI absorption in the IGM at z < 0.5. We identify
51 intervening (z_{abs} << z_{QSO}) O VI systems comprised of 77 individual
components, and we find 14 "proximate" systems (z_{abs} ~ z_{QSO}) containing
34 components. For intervening systems [components] with rest-frame equivalent
width W_{r} > 30 mA, the number of O VI absorbers per unit redshift dN/dz =
15.6(+2.9/-2.4) [21.0(+3.2/-2.8)], and this decreases to dN/dz = 0.9(+1.0/-0.5)
[0.3(+0.7/-0.3)] for W_{r} > 300 mA. The number per redshift increases steeply
as z_{abs} approaches z_{QSO}, and some proximate absorbers have substantially
lower H I/O VI ratios. The lower proximate ratios could be partially due to
ionization effects but also require higher metallicities. We find that 37% of
the intervening O VI absorbers have velocity centroids that are well-aligned
with corresponding H I absorption. If the O VI and the H I trace the same gas,
the relatively small differences in line widths imply the absorbers are cool
with T < 10^{5} K. Most of these well-aligned absorbers have the
characteristics of metal-enriched photoionized gas. However, the O VI in the
apparently simple and cold systems could be associated with a hot phase with T
~ 10^{5.5} K if the metallicity is high enough to cause the associated broad Ly
alpha absorption to be too weak to detect. We show that 53% of the intervening
O VI systems are complex multiphase absorbers that can accommodate both lower
metallicity collisionally-ionized gas with T > 10^{5} K and cold photoionzed
gas.


title: Depth three towers and Jacobson-Bourbaki correspondence

abstract:
  We introduce a notion of depth three tower of three rings C < B < A as a
useful generalization of depth two ring extension. If A = End B_C and B | C is
a Frobenius extension, this also captures the notion of depth three for a
Frobenius extension in math.RA/0107064 and math.RA/0108067 such that if B | C
is depth three, then A | C is depth two (cf. math.QA/0001020). If A, B and C
correspond to a tower of subgroups G > H > K via the group algebra over a fixed
base ring, the depth three condition is the condition that subgroup K has
normal closure K^G contained in H. For a depth three tower of rings, there is a
pre-Galois theory for the ring End {}_BA_C and coring (A \otimes_B A)^C
involving Morita context bimodules and left coideal subrings. This is applied
in the last two sections to a specialization of a Jacobson-Bourbaki
correspondence theorem for augmented rings to depth two extensions with depth
three intermediate division rings.


title: Do charged leptons oscillate?

abstract:
  The question of whether charged leptons oscillate is discussed in detail,
with a special emphasis on the coherence properties of the charged lepton
states created via weak interactions. This analysis allows one to clarify also
an important issue of the theory of neutrino oscillations.


title: Constant Weight Codes: A Geometric Approach Based on Dissections

abstract:
  We present a novel technique for encoding and decoding constant weight binary
codes that uses a geometric interpretation of the codebook. Our technique is
based on embedding the codebook in a Euclidean space of dimension equal to the
weight of the code. The encoder and decoder mappings are then interpreted as a
bijection between a certain hyper-rectangle and a polytope in this Euclidean
space. An inductive dissection algorithm is developed for constructing such a
bijection. We prove that the algorithm is correct and then analyze its
complexity. The complexity depends on the weight of the code, rather than on
the block length as in other algorithms. This approach is advantageous when the
weight is smaller than the square root of the block length.


title: A general convergence result for the Ricci flow in higher dimensions

abstract:
  Let (M,g_0) be a compact Riemannian manifold of dimension n \geq 4. We show
that the normalized Ricci flow deforms g_0 to a constant curvature metric
provided that (M,g_0) x R has positive isotropic curvature. This condition is
stronger than 2-positive flag curvature but weaker than 2-positive curvature
operator.


title: Efficient Quantum Algorithm for Identifying Hidden Polynomials

abstract:
  We consider a natural generalization of an abelian Hidden Subgroup Problem
where the subgroups and their cosets correspond to graphs of linear functions
over a finite field F with d elements. The hidden functions of the generalized
problem are not restricted to be linear but can also be m-variate polynomial
functions of total degree n>=2.
  The problem of identifying hidden m-variate polynomials of degree less or
equal to n for fixed n and m is hard on a classical computer since
Omega(sqrt{d}) black-box queries are required to guarantee a constant success
probability. In contrast, we present a quantum algorithm that correctly
identifies such hidden polynomials for all but a finite number of values of d
with constant probability and that has a running time that is only
polylogarithmic in d.


title:
H-alpha tail, intracluster HII regions and star-formation: ESO137-001 in
  Abell 3627

abstract:
  We present the discovery of a 40 kpc H-alpha tail and at least 29
emission-line objects downstream of a star-forming galaxy ESO 137-001 in the
rich, nearby cluster A3627. The galaxy is known to possess a dramatic 70 kpc
X-ray tail. The detected H-alpha tail coincides positionally with the X-ray
tail. The H-alpha emission in the galaxy is sharply truncated on the front and
the sides near the nucleus, indicating significant ram pressure stripping. ESO
137-001 is thus the first cluster late-type galaxy known unambiguously with
both an X-ray tail and an H-alpha tail. The emission-line objects are all
distributed downstream of the galaxy, with projected distance up to 39 kpc from
the galaxy. From the analysis on the H-alpha_{off} frame and the estimate of
the background emission-line objects, we conclude that it is very likely all 29
emission-line objects are HII regions in A3627. The high surface number density
and luminosities of these HII regions (up to 10^40 ergs/s) dwarf the previously
known examples of isolated HII regions in clusters. We suggest that star
formation may proceed in the stripped ISM, in both the galactic halo and
intracluster space. The total mass of formed stars in the stripped ISM of ESO
137-001 may approach several times 10^7 solar masses. Therefore, stripping of
the ISM not only contributes to the ICM, but also adds to the intracluster
stellar light through subsequent star formation. The data also imply that ESO
137-001 is in an active stage of transformation, accompanied by the build-up of
a central bulge and depletion of the ISM.


title: Radial Velocities of Six OB Stars

abstract:
  We present new results from a radial velocity study of six bright OB stars
with little or no prior measurements. One of these, HD 45314, may be a
long-period binary, but the velocity variations of this Be star may be related
to changes in its circumstellar disk. Significant velocity variations were also
found for HD 60848 (possibly related to nonradial pulsations) and HD 61827
(related to wind variations). The other three targets, HD 46150, HD 54879, and
HD 206183, are constant velocity objects, but we note that HD 54879 has
H$\alpha$ emission that may originate from a binary companion. We illustrate
the average red spectrum of each target.


title: All orders proton breakup from exotic nuclei

abstract:
  We present a semiclassical method to treat the proton breakup from a weakly
bound state in an exotic nucleus. The Coulomb interactions between the proton,
core and target are treated to all orders and including the full multipole
expansion of the Coulomb potential. The nuclear proton-target interaction is
also treated to all orders. The core-target interaction is included as an
absorption. The method is semi-analytical thus allowing for a detailed
understanding of the short range and long range effects of the interactions in
the reaction dynamics. It explains also the origin of possible asymmetries in
the core parallel momentum distributions when the full multipole expansion of
the Coulomb potential is used. Calculations are compared to results of other,
fully numerical, methods and to experimental data in order to establish the
accuracy and reliability of the method.


title: The phase space view of f(R) gravity

abstract:
  We study the geometry of the phase space of spatially flat
Friedmann-Lemaitre-Robertson-Walker models in f(R) gravity, for a general form
of the function f(R). The equilibrium points (de Sitter spaces) and their
stability are discussed, and a comparison is made with the phase space of the
equivalent scalar-tensor theory. New effective Lagrangians and Hamiltonians are
also presented.


title: Constructive Matrix Theory

abstract:
  We extend the technique of constructive expansions to compute the connected
functions of matrix models in a uniform way as the size of the matrix
increases. This provides the main missing ingredient for a non-perturbative
construction of the $\phi^{\star 4}_4$ field theory on the Moyal four
dimensional space.


title:
Enrichment of the ISM by metal-rich droplets and the abundance bias in
  HII regions

abstract:
  We critically examine a scenario for the enrichment of the interstellar
medium (ISM) in which supernova ejecta follow a long (10^8 yr) journey before
falling back onto the galactic disk in the form of metal-rich ``droplets'',
These droplets do not become fully mixed with the interstellar medium until
they become photoionized in HII regions. We investigate the hypothesis that the
photoionization of these highly metallic droplets can explain the observed
``abundance discrepancy factors'' (ADFs), which are found when comparing
abundances derived from recombination lines and from collisionally excited
lines, both in Galactic and extragalactic HII regions. We derive bounds of
10^{13}--10^{15} cm on the droplet sizes inside HII regions in order that (1)
they should not have already been detected by direct imaging of nearby nebulae,
and (2) they should not be too swiftly destroyed by diffusion in the ionized
gas. From photoionization modelling we find that, if this inhomogeneous
enrichment scenario holds, then the recombination lines strongly overestimate
the metallicities of the fully mixed HII regions. The abundances derived from
collisionally excited lines also suffer some bias, although to a much lesser
extent. In the absence of any recipe for correcting these biases, we recommend
the discarding of all objects showing large ADFs from studies of galactic
chemical evolution. These biases must also be kept in mind when comparing the
galactic abundance gradients for elements derived from recombination lines with
those derived from collisionally excited lines. Finally, we propose a set of
observations that could be undertaken to test our scenario and improve our
understanding of element mixing in the ISM.


title: On the cost-subdifferentials of cost-convex functions

abstract:
  We are interested in the cost-convex potentials in optimal mass transport
theory, and we show by direct and geometric arguments the equivalence between
cost-subdifferentials and ordinary subdifferentials of cost-convex functions,
under the assumptions A0, A1, A2, and A3W on cost functions introduced by Ma,
Trudinger, and Wang. The connectivity of contact sets of optimal transport maps
follows as a direct corollary. Our approach is quite different from the
previous result of Loeper which he obtained as the first step toward his
Hoelder regularity theory of potential functions, and which was based upon
approximation using the regularity theory of Ma, Trudinger, and Wang. The
result in this paper improves his result, by relaxing certain geometrical
assumptions on the domains and targets; it also completes his Hoelder
regularity theory of potential functions on the round sphere, by making it
self-contained.


title:
Invisible Z decay width bounds on active-sterile neutrino mixing in the
  (3+1) and (3+2) models

abstract:
  In this work we consider the standard model extended with singlet sterile
neutrinos with mass in the eV range and mixed with the active neutrinos. The
active-sterile neutrino mixing renders new contributions to the invisible Z
decay width which, in the case of light sterile neutrinos, depends on the
active-sterile mixing matrix elements only. We then use the current
experimental value of the invisible Z decay width to obtain bounds on these
mixing matrix elements for both (3+1) and (3+2) models.


title:
Quantum information technology with Sagnac interferometer:
  Interaction-free measurement, quantum key distribution and quantum secret
  sharing

abstract:
  The interferometry of single-photon pulses has been used to implement quantum
technology systems, like quantum key distribution, interaction-free measurement
and some other quantum communication protocols. In most of these
implementations, Mach-Zehnder, Michelson and Fabry-Perot interferometers are
the most used. In this work we present optical setups for interaction-free
measurement, quantum key distribution and quantum secret sharing using the
Sagnac interferometer. The proposed setups are described as well the quantum
protocols using them are explained.


title: Cosmological Charge Asymmetry and Rare Processes in Particle Physics

abstract:
  Two scenarios of low temperature baryogenesis in theories with TeV scale
gravity are discussed. It is argued that strong gravity at TeV energies is very
favorable for baryogenesis. In both scenarios the proton decay is either absent
or suppressed far below existing bounds. On the other hand, neutron-antineutron
oscillations are at the verge of discovery. Some other rare decays with
non-conservation of lepton or baryon numbers are predicted.


title:
Three bodies bind even when two do not: Efimov states and Fano
  resonances in atoms and nuclei

abstract:
  Efimov's prediction more than three decades ago that three-body bound states
can exist when the pairwise attractions do not bind or only support weakly
bound states of a pair, has remained unconfirmed till just the past year. This
lecture provides the pedagogical background for recent work on Efimov states in
neutron-rich nuclei done with I. Mazumdar (TIFR) and V. S. Bhasin (Delhi
University), and published in Phys. Rev. Lett. 97, 062503 (2006). Both these
nuclear systems and recent observations of cold cesium atoms provide the first
clear evidence for the existence of Efimov states.


title: The Black Di-Ring: An Inverse Scattering Construction

abstract:
  We use the inverse scattering method (ISM) to derive concentric
non-supersymmetric black rings. The approach used here is fully
five-dimensional, and has the modest advantage that it generalizes readily to
the construction of more general axi-symmetric solutions.


title: New Insights on Time-Symmetry in Quantum Mechanics

abstract: A review of new aspects concerning time-symmetry in Quantum Mechanics.


title: Universes out of almost empty space

abstract:
  Baby universes (inflationary or non--inflationary) are regions of spacetime
that disconnect from the original ambient spacetime, which we take to be
asymptotically flat spacetime. A particular kind of baby universe solution,
involving string--like matter, is studied to show that it can be formed by
``investing'' an arbitrarily small amount of energy, i.e. it can appear from an
almost flat space at the classical level. Since this possibility has not yet
been clearly recognized in the literature, we then discuss in detail its
properties, relevance and possible generalizations.


title:
Convergence of iterated Aluthge transform sequence for diagonalizable
  matrices II: $\lambda$-Aluthge transform

abstract:
  Let $\lambda \in (0,1)$ and let $T$ be a $r\times r$ complex matrix with
polar decomposition $T=U|T|$. Then, the $\la$- Aluthge transform is defined by
$$ \Delta_\lambda (T )= |T|^{\lambda} U |T |^{1-\lambda}. $$ Let
$\Delta_\lambda^{n}(T)$ denote the n-times iterated Aluthge transform of $T$,
$n\in\mathbb{N}$. We prove that the sequence
$\{\Delta_\lambda^{n}(T)\}_{n\in\mathbb{N}}$ converges for every $r\times r$
{\bf diagonalizable} matrix $T$. We show regularity results for the two
parameter map $(\la, T) \mapsto \alulit{\infty}{T}$, and we study for which
matrices the map $(0,1)\ni \lambda \mapsto \Delta_\lambda^{\infty}(T)$ is
constant.


title:
From mean-motion resonances to scattered planets: Producing the Solar
  System, eccentric exoplanets and Late Heavy Bombardments

abstract:
  We show that interaction with a gas disk may produce young planetary systems
with closely-spaced orbits, stabilized by mean-motion resonances between
neighbors. On longer timescales, after the gas is gone, interaction with a
remnant planetesimal disk tends to pull these configurations apart, eventually
inducing dynamical instability. We show that this can lead to a variety of
outcomes; some cases resemble the Solar System, while others end up with
high-eccentricity orbits reminiscent of the observed exoplanets. A similar
mechanism has been previously suggested as the cause of the lunar Late Heavy
Bombardment. Thus, it may be that a large-scale dynamical instability, with
more or less cataclysmic results, is an evolutionary step common to many
planetary systems, including our own.


title:
Kinetic-Ion Simulations Addressing Whether Ion Trapping Inflates
  Stimulated Brillouin Backscattering Reflectivities

abstract:
  An investigation of the possible inflation of stimulated Brillouin
backscattering (SBS) due to ion kinetic effects is presented using
electromagnetic particle simulations and integrations of three-wave
coupled-mode equations with linear and nonlinear models of the nonlinear ion
physics. Electrostatic simulations of linear ion Landau damping in an ion
acoustic wave, nonlinear reduction of damping due to ion trapping, and
nonlinear frequency shifts due to ion trapping establish a baseline for
modeling the electromagnetic SBS simulations. Systematic scans of the laser
intensity have been undertaken with both one-dimensional particle simulations
and coupled-mode-equations integrations, and two values of the electron-to-ion
temperature ratio (to vary the linear ion Landau damping) are considered. Three
of the four intensity scans have evidence of SBS inflation as determined by
observing more reflectivity in the particle simulations than in the
corresponding three-wave mode-coupling integrations with a linear ion-wave
model, and the particle simulations show evidence of ion trapping.


title: Tailoring Graphene with Metals on Top

abstract:
  We study the effects of metallic doping on the electronic properties of
graphene using density functional theory in the local density approximation in
the presence of a local charging energy (LDA+U). The electronic properties are
sensitive to whether graphene is doped with alkali or transition metals. We
estimate the the charge transfer from a single layer of Potassium on top of
graphene in terms of the local charging energy of the graphene sheet. The
coating of graphene with a non-magnetic layer of Palladium, on the other hand,
can lead to a magnetic instability in coated graphene due to the hybridization
between the transition-metal and the carbon orbitals.


title: Backreacting Flavors in the Klebanov-Strassler Background

abstract:
  In this paper we present new analytic solutions of pure Type IIB supergravity
plus D7-branes describing the addition of an arbitrary number of flavors to the
Klebanov-Tseytlin and Klebanov-Strassler backgrounds. We provide a precise
field theory dual and a detailed analysis of the duality cascade which
describes its RG flow. Matchings of beta functions and anomalies between the
field theory and the string setup are presented. We give an understanding of
Seiberg duality as a large gauge transformation on the RR and NSNS potentials.
We also analyze the UV behavior of the field theory, that as suggested by the
string background can be associated with a duality wall.


title:
Water vapour and hydrogen in the terrestrial-planet-forming region of a
  protoplanetary disk

abstract:
  Planetary systems, ours included, are formed in disks of dust and gas around
young stars. Disks are an integral part of the star and planet formation
process, and knowledge of the distribution and temperature of inner disk
material is crucial for understanding terrestrial planet formation, giant
planet migration, and accretion onto the central star. While the inner regions
of protoplanetary disks in nearby star forming regions subtend only a few
nano-radians, near-IR interferometry has recently enabled the spatial
resolution of these terrestrial zones. Most observations have probed only dust,
which typically dominates the near-IR emission. Here I report spectrally
dispersed near-IR interferometric observations that probe gas (which dominates
the mass and dynamics of the inner disk), in addition to dust, within one
astronomical unit of the young star MWC 480. I resolve gas, including water
vapor and atomic hydrogen, interior to the edge of the dust disk; this
contrasts with results of previous spectrally dispersed interferometry
observations. Interactions of this accreting gas with migrating planets may
lead to short-period exoplanets like those detected around main-sequence stars.
The observed water vapor is likely produced by the sublimation of migrating icy
bodies, and provides a potential reservoir of water for terrestrial planets.


title: Phenomenology of D-Brane Inflation with General Speed of Sound

abstract:
  A characteristic of D-brane inflation is that fluctuations in the inflaton
field can propagate at a speed significantly less than the speed of light. This
yields observable effects that are distinct from those of single-field slow
roll inflation, such as a modification of the inflationary consistency relation
and a potentially large level of non-Gaussianities. We present a numerical
algorithm that extends the inflationary flow formalism to models with general
speed of sound. For an ensemble of D-brane inflation models parameterized by
the Hubble parameter and the speed of sound as polynomial functions of the
inflaton field, we give qualitative predictions for the key inflationary
observables. We discuss various consistency relations for D-brane inflation,
and compare the qualitative shapes of the warp factors we derive from the
numerical models with analytical warp factors considered in the literature.
Finally, we derive and apply a generalized microphysical bound on the inflaton
field variation during brane inflation. While a large number of models are
consistent with current cosmological constraints, almost all of these models
violate the compactification constraint on the field range in four-dimensional
Planck units. If the field range bound is to hold, then models with a
detectable level of non-Gaussianity predict a blue scalar spectral index, and a
tensor component that is far below the detection limit of any future
experiment.


title:
Inside-Out Evacuation of Transitional Protoplanetary Disks by the
  Magneto-Rotational Instability

abstract:
  How do T Tauri disks accrete? The magneto-rotational instability (MRI)
supplies one means, but protoplanetary disk gas is typically too poorly ionized
to be magnetically active. Here we show that the MRI can, in fact, explain
observed accretion rates for the sub-class of T Tauri disks known as
transitional systems. Transitional disks are swept clean of dust inside rim
radii of ~10 AU. Stellar coronal X-rays ionize material in the disk rim,
activating the MRI there. Gas flows from the rim to the star, at a rate limited
by the depth to which X-rays ionize the rim wall. The wider the rim, the larger
the surface area that the rim wall exposes to X-rays, and the greater the
accretion rate. Interior to the rim, the MRI continues to transport gas; the
MRI is sustained even at the disk midplane by super-keV X-rays that Compton
scatter down from the disk surface. Accretion is therefore steady inside the
rim. Blown out by radiation pressure, dust largely fails to accrete with gas.
Contrary to what is usually assumed, ambipolar diffusion, not Ohmic
dissipation, limits how much gas is MRI-active. We infer values for the
transport parameter alpha on the order of 0.01 for GM Aur, TW Hyd, and DM Tau.
Because the MRI can only afflict a finite radial column of gas at the rim, disk
properties inside the rim are insensitive to those outside. Thus our picture
provides one robust setting for planet-disk interaction: a protoplanet interior
to the rim will interact with gas whose density, temperature, and transport
properties are definite and decoupled from uncertain initial conditions. Our
study also supplies half the answer to how disks dissipate: the inner disk
drains from the inside out by the MRI, while the outer disk photoevaporates by
stellar ultraviolet radiation.


title:
Subtractive renormalization of the NN scattering amplitude at leading
  order in chiral effective theory

abstract:
  The leading-order nucleon-nucleon (NN) potential derived from chiral
perturbation theory consists of one-pion exchange plus a short-distance contact
interaction. We show that in the 1S0 and 3S1-3D1 channels renormalization of
the Lippmann-Schwinger equation for this potential can be achieved by
performing one subtraction. This subtraction requires as its only input
knowledge of the NN scattering lengths. This procedure leads to a set of
integral equations for the partial-wave NN t-matrix which give
cutoff-independent results for the corresponding NN phase shifts. This
reformulation of the NN scattering equation offers practical advantages,
because only observable quantities appear in the integral equation. The
scattering equation may then be analytically continued to negative energies,
where information on bound-state energies and wave functions can be extracted.


title:
A Cosmological Framework for the Co-Evolution of Quasars, Supermassive
  Black Holes, and Elliptical Galaxies: I. Galaxy Mergers & Quasar Activity

abstract:
  (Abridged) We develop a model for the cosmological role of mergers in the
evolution of starbursts, quasars, and spheroidal galaxies. Combining halo mass
functions (MFs) with empirical halo occupation models, we calculate where major
galaxy-galaxy mergers occur and what kinds of galaxies merge, at all redshifts.
We compare with observed merger MFs, clustering, fractions, and small-scale
environments, and show that this yields robust estimates in good agreement with
observations. Making the simple ansatz that major, gas-rich mergers cause
quasar activity, we demonstrate that this naturally reproduces the observed
rise and fall of the quasar luminosity density from z=0-6, as well as quasar
LFs, fractions, host galaxy colors, and clustering as a function of redshift
and luminosity. The observed excess of quasar clustering on small scales is a
natural prediction of the model, as mergers preferentially occur in regions
with excess small-scale galaxy overdensities. We show that quasar environments
at all observed redshifts correspond closely to the empirically determined
small group scale, where mergers of gas-rich galaxies are most efficient. We
contrast with a secular model in which quasar activity is driven by bars/disk
instabilities, and show that while these modes probably dominate at Seyfert
luminosities, the constraints from clustering (large and small-scale),
pseudobulge populations, disk MFs, luminosity density evolution, and host
galaxy colors argue that they must be a small contributor to the z>1 quasar
luminosity density.


title:
Supersymmetric sources, integrability and generalized-structure
  compactifications

abstract:
  In the context of supersymmetric compactifications of type II supergravity to
four dimensions, we show that orientifold sources can be compatible with a
generalized SU(3) x SU(3)-structure that is neither strictly SU(3) nor static
SU(2). We illustrate this with explicit examples, obtained by suitably
T-dualizing known solutions on the six-torus. In addition we prove the
following integrability statements, valid under certain mild assumptions: (a)
for general type II supergravity backgrounds with orientifold and/or D-brane
generalized-calibrated sources, the source-corrected Einstein and dilaton
equations of motion follow automatically from the supersymmetry equations once
the likewise source-corrected form equations of motion and Bianchi identities
are imposed; (b) in the special case of supersymmetric compactifications to
four-dimensional Minkowski space, the equations of motion of all fields,
including the NSNS three-form, follow automatically once the supersymmetry and
the Bianchi identities of the forms are imposed. Both (a) and (b) are equally
valid whether the sources are smeared or localized. As a byproduct we obtain
the calibration form for a space-filling NS5-brane.


title:
Evidence for a ferromagnetic quantum critical point in URhGe doped with
  Ru

abstract:
  We have investigated the evolution of ferromagnetic order in the correlated
metal series URh_{1-x}Ru_{x}Ge. Magnetization, transport and specific heat
measurements provide convincing evidence for a ferromagnetic quantum critical
point at the critical concentration x_{c} = 0.38. Here we report
ac-susceptibility and magnetization measurements on selected samples with Ru
doping concentrations near the critical point.