title: Probing the Interiors of Very Hot Jupiters Using Transit Light Curves

abstract:
  Accurately understanding the interior structure of extra-solar planets is
critical for inferring their formation and evolution. The internal density
distribution of a planet has a direct effect on the star-planet orbit through
the gravitational quadrupole field created by the rotational and tidal bulges.
These quadrupoles induce apsidal precession that is proportional to the
planetary Love number ($k_{2p}$, twice the apsidal motion constant), a bulk
physical characteristic of the planet that depends on the internal density
distribution, including the presence or absence of a massive solid core. We
find that the quadrupole of the planetary tidal bulge is the dominant source of
apsidal precession for very hot Jupiters ($a \lesssim 0.025$ AU), exceeding the
effects of general relativity and the stellar quadrupole by more than an order
of magnitude. For the shortest-period planets, the planetary interior induces
precession of a few degrees per year. By investigating the full photometric
signal of apsidal precession, we find that changes in transit shapes are much
more important than transit timing variations. With its long baseline of
ultra-precise photometry, the space-based \emph{Kepler} mission can
realistically detect apsidal precession with the accuracy necessary to infer
the presence or absence of a massive core in very hot Jupiters with orbital
eccentricities as low as $e \simeq 0.003$. The signal due to $k_{2p}$ creates
unique transit light curve variations that are generally not degenerate with
other parameters or phenomena. We discuss the plausibility of measuring
$k_{2p}$ in an effort to directly constrain the interior properties of
extra-solar planets.


title:
Abelian Chern-Simons theory with toral gauge group, modular tensor
  categories, and group categories

abstract:
  Classical and quantum Chern-Simons with gauge group $\text{U}(1)^N$ were
classified by Belov and Moore in \cite{belov_moore}. They studied both ordinary
topological quantum field theories as well as spin theories. On the other hand
a correspondence is well known between ordinary $(2+1)$-dimensional TQFTs and
modular tensor categories. We study group categories and extend them slightly
to produce modular tensor categories that correspond to toral Chern-Simons.
Group categories have been widely studied in other contexts in the literature
\cite{frolich_kerler},\cite{quinn},\cite{joyal_street},\cite{eno},\cite{dgno}.
The main result is a proof that the associated projective representation of the
mapping class group is isomorphic to the one from toral Chern-Simons. We also
remark on an algebraic theorem of Nikulin that is used in this paper.


title:
Superintegrability with third order integrals of motion, cubic algebras
  and supersymmetric quantum mechanics I:Rational function potentials

abstract:
  We consider a superintegrable Hamiltonian system in a two-dimensional space
with a scalar potential that allows one quadratic and one cubic integral of
motion. We construct the most general cubic algebra and we present specific
realizations. We use them to calculate the energy spectrum. All classical and
quantum superintegrable potentials separable in Cartesian coordinates with a
third order integral are known. The general formalism is applied to quantum
reducible and irreducible rational potentials separable in Cartesian
coordinates in E2. We also discuss these potentials from the point of view of
supersymmetric and PT-symmetric quantum mechanics.


title:
The Transport Capacity of a Wireless Network is a Subadditive Euclidean
  Functional

abstract:
  The transport capacity of a dense ad hoc network with n nodes scales like
\sqrt(n). We show that the transport capacity divided by \sqrt(n) approaches a
non-random limit with probability one when the nodes are i.i.d. distributed on
the unit square. We prove that the transport capacity under the protocol model
is a subadditive Euclidean functional and use the machinery of subadditive
functions in the spirit of Steele to show the existence of the limit.


title:
Flows and Non-thermal Velocities in Solar Active Regions Observed with
  the Extreme-ultraviolet Imaging Spectrometer on Hinode: A Tracer of Active
  Region Sources of Heliospheric Magnetic Fields?

abstract:
  From Doppler velocity maps of active regions constructed from spectra
obtained by the Extreme-ultraviolet Imaging Spectrometer (EIS) on the Hinode
spacecraft we observe large areas of outflow (20-50 km/s) that can persist for
at least a day. These outflows occur in areas of active regions that are faint
in coronal spectral lines formed at typical quiet Sun and active region
temperatures. The outflows are positively correlated with non-thermal
velocities in coronal plasmas. The bulk mass motions and non-thermal velocities
are derived from spectral line centroids and line widths, mostly from a strong
line of Fe XII at 195.12 Angstroms. The electron temperature of the outflow
regions estimated from an Fe XIII to Fe XII line intensity ratio is about
1.2-1.4 MK. The electron density of the outflow regions derived from a density
sensitive intensity ratio of Fe XII lines is rather low for an active region.
Most regions average around 7E10+8 cm(-3), but there are variations on pixel
spatial scales of about a factor of 4. We discuss results in detail for two
active regions observed by EIS. Images of active regions in line intensity,
line width, and line centroid are obtained by rastering the regions. We also
discuss data from the active regions obtained from other orbiting spacecraft
that support the conclusions obtained from analysis of the EIS spectra. The
locations of the flows in the active regions with respect to the longitudinal
photospheric magnetic fields suggest that these regions might be tracers of
long loops and/or open magnetic fields that extend into the heliosphere, and
thus the flows could possibly contribute significantly to the solar wind.


title:
Giant magnons in AdS_4/CFT_3: dispersion, quantization and finite--size
  corrections

abstract:
  We study giant magnon solutions in AdS4 \times CP3. We compute quantum
corrections to their dispersion relation. We find out that the one--loop
correction vanishes in infinite volume. This implies that the interpolating
function h(\lambda) between strong and weak coupling regimes does not have a
constant term \lambda^0 at strong coupling. We also compute first nonvanishing
finite volume correction to the one--loop expression. When compared to the
L\"{u}sher formula, our results could provide a nontrivial check of the AdS4
\times CP3 S--matrix proposed recently in arXiv:0807.1924.


title: Testing Magnetic Star Formation Theory

abstract:
  We report here observations of the Zeeman effect in the 18-cm lines of OH in
the envelope regions surrounding four molecular cloud cores toward which
detections of B(LOS) have been achieved in the same lines, and evaluate the
ratio of mass to magnetic flux, M/Phi, between the cloud core and envelope.
This relative M/Phi measurement reduces uncertainties in previous studies, such
as the angle between B and the line of sight and the value of [OH/H]. Our
result is that for all four clouds, the ratios R of the core to the envelope
values of M/Phi are less than 1. Stated another way, the ratios R' of the core
to the total cloud M/Phi are less than 1. The extreme case or idealized (no
turbulence) ambipolar diffusion theory of core formation requires the ratio of
the central to total M/Phi to be approximately equal to the inverse of the
original subcritical M/Phi, or R' > 1. The probability that all four of our
clouds have R' > 1 is 3 x 10^{-7}; our results are therefore significantly in
contradiction with the hypothesis that these four cores were formed by
ambipolar diffuson. Highly super-Alfvenic turbulent simulations yield a wide
range of relative M/Phi, but favor a ratio R < 1, as we observe. Our experiment
is limited to four clouds, and we can only directly test the predictions of the
extreme-case "idealized" models of ambipolar-diffusion driven star formation
that have a regular magnetic field morphology. Nonetheless, our experimental
results are not consistent with the "idealized" strong field, ambipolar
diffusion theory of star formation.


title: Cold Dark Matter Substructure and Galactic Disks

abstract:
  We perform a set of high-resolution, dissipationless N-body simulations to
investigate the influence of cold dark matter (CDM) substructure on the
dynamical evolution of thin galactic disks. Our method combines cosmological
simulations of galaxy-sized CDM halos to derive the properties of substructure
populations and controlled numerical experiments of consecutive subhalo impacts
onto initially-thin, fully-formed disk galaxies. We demonstrate that close
encounters between massive subhalos and galactic disks since z~1 should be
common occurrences in LCDM models. In contrast, extremely few satellites in
present-day CDM halos are likely to have a significant impact on the disk
structure. One typical host halo merger history is used to seed controlled
N-body experiments of subhalo-disk encounters. As a result of these accretion
events, the disk thickens considerably at all radii with the disk scale height
increasing in excess of a factor of 2 in the solar neighborhood. We show that
interactions with the subhalo population produce a wealth of distinctive
morphological signatures in the disk stars including: conspicuous flares; bars;
low-lived, ring-like features in the outskirts; and low-density, filamentary
structures above the disk plane. We compare a resulting dynamically-cold,
ring-like feature in our simulations to the Monoceros ring stellar structure in
the MW. The comparison shows quantitative agreement in both spatial
distribution and kinematics, suggesting that such observed complex stellar
components may arise naturally as disk stars are excited by encounters with
subhalos. These findings highlight the significant role of CDM substructure in
setting the structure of disk galaxies and driving galaxy evolution.


title: The Instability of Vacua in Gauss-Bonnet Gravity

abstract:
  Owing to the quadratic nature of the theory, Einstein-Gauss-Bonnet gravity
generically permits two distinct vacuum solutions. One solution (the "Einstein"
vacuum) has a well defined limit as the Gauss-Bonnet coupling goes to zero,
whereas the other solution (the "stringy" vacuum) does not. There has been some
debate regarding the stability of these vacua, most recently from Deser and
Tekin who have argued that the corresponding black hole solutions have positive
mass and as such both vacua are stable. Whilst the statement about the mass is
correct, we argue that the stringy vacuum is still perturbatively unstable.
Simply put, the stringy vacuum suffers from a ghost-like instability that is
not excited by the spherically symmetric black hole, but would be excited by
any source likely to emit gravitational waves, such as a binary system. This
result is reliable except in the strongly coupled regime close to the
Chern-Simons limit, when the two vacua are almost degenerate. In this regime,
we study instanton transitions between branches via bubble nucleation, and
calculate the nucleation probability. This demonstrates that there is large
mixing between the vacua, so that neither of them can accurately describe the
true quantum vacuum. We also present a new gravitational instanton describing
black hole pair production in de Sitter space on the Einstein branch, which is
preferred to the usual Nariai instantons, and is not present in pure Einstein
gravity.


title: Thin position and planar surfaces for graphs in the 3-sphere

abstract:
  We show that given a trivalent graph in $S^3$, either the graph complement
contains an essential almost meridional planar surface or thin position for the
graph is also bridge position. This can be viewed as an extension of a theorem
of Thompson to graphs. It follows that any graph complement always contains a
useful planar surface.


title: Bounding the stable genera of Heegaard splittings from below

abstract:
  We describe for each postive integer $k$ a 3-manifold with Heegaard surfaces
of genus $2k$ and $2k-1$ such that any common stabilization of these two
surfaces has genus at least $3k-1$. We also show that for every positive $n$,
there is a 3-manifold that has $n$ pairwise non-isotopic Heegaard splittings of
the same genus all of which are stabilized.


title: Onset of an Insulating Zero-Plateau Quantum Hall State in Graphene

abstract:
  We analyze the dissipative conductance of the zero-plateau quantum Hall state
appearing in undoped graphene in strong magnetic fields. Charge transport in
this state is assumed to be carried by a magnetic domain wall, which forms by
hybridization of two counter--propagating edge states of opposing spin due to
interactions. The resulting non--chiral edge mode is a Luttinger liquid of
parameter K, which enters a gapped, perfectly conducting state below a critical
value K_c\approx 1/2. Backscattering in this system involves spin flip, so that
interaction with localized magnetic moments generates a finite resistivity
R_{xx} via a "chiral Kondo effect". At finite temperatures T, R_{xx}(T)
exhibits a crossover from metallic to insulating behavior as K is tuned across
a threshold K_{MI}. For T->0, R_{xx} in the intermediate regime K_{MI}<K<K_c is
finite, but diverges as K approaches K_c. This model provides a natural
interpretation of recent experiments.


title:
Dissipation and Extra Light in Galactic Nuclei: IV. Evolution in the
  Scaling Relations of Spheroids

abstract:
  We develop a model for the origins and redshift evolution of spheroid scaling
relations. We consider spheroid sizes, velocity dispersions, masses, profile
shapes (Sersic indices), and black hole (BH) masses, and their related
scalings. Our approach combines advantages of observational constraints in halo
occupation models and hydrodynamic merger simulations. This allows us to
separate the relative roles of dissipation, dry mergers, formation time, and
progenitor evolution, and identify their effects on scalings at each redshift.
Dissipation is the most important factor determining spheroid sizes and
fundamental plane (FP) scalings, and can account for the FP tilt and
differences between disk and spheroid scalings. Because disks at high-z have
higher gas fractions, mergers are more gas-rich, yielding more compact
spheroids. This predicts mass-dependent evolution in spheroid sizes, in
agreement with observations. This relates to subtle evolution in the FP,
important to studies that assume a fixed intrinsic FP. This also predicts mild
evolution in BH-host correlations, towards larger BHs at higher z. Dry mergers
are significant, but only for massive systems which form early: they form
compact, but undergo dry mergers (consistent with observations) such that their
sizes at later times are similar to spheroids of similar mass formed more
recently. We model descendants of observed compact high-z spheroids: most will
become cores of BCGs, with sizes, velocity dispersions, and BH masses
consistent with observations, but we identify a fraction that might survive to
z=0 intact.


title: Heegaard surfaces and the distance of amalgamation

abstract:
  Let $M_1$ and $M_2$ be orientable irreducible 3--manifolds with connected
boundary and suppose $\partial M_1\cong\partial M_2$. Let $M$ be a closed
3--manifold obtained by gluing $M_1$ to $M_2$ along the boundary. We show that
if the gluing homeomorphism is sufficiently complicated, then $M$ is not
homeomorphic to $S^3$ and all small-genus Heegaard splittings of $M$ are
standard in a certain sense. In particular, $g(M)=g(M_1)+g(M_2)-g(\partial
M_i)$, where $g(M)$ denotes the Heegaard genus of $M$. This theorem is also
true for certain manifolds with multiple boundary components.


title: Travelling waves and impact-parameter correlations

abstract:
  It is usually assumed that the high-energy evolution of partons in QCD
remains local in coordinate space. In particular, fixed impact-parameter
scattering is thought to be in the universality class of one-dimensional
reaction-diffusion processes as if the evolutions at different points in the
transverse plane became uncorrelated through rapidity evolution. We check this
assumption by numerically comparing a toy model with QCD-like impact-parameter
dependence to its exact counterpart with uniform evolution in impact-parameter
space. We find quantitative differences, but which seem to amount to a mere
rescaling of the strong coupling constant. Since the rescaling factor does not
show any strong alpha_s-dependence, we conclude that locality is well verified,
up to subleading terms at small alpha_s.


title:
Algorithms and Classification in Groups of Piecewise-Linear
  Homeomorphisms

abstract:
  This manuscript represents the author's PhD dissertation thesis.The first
part studies decision problems in Thompson's groups F,T,V and some
generalizations. The simultaneous conjugacy problem is determined to be
solvable for Thompson's group F and suitable larger groups of piecewise-linear
homeomorphisms of the unit interval. We determine algorithms to compute roots
and centralizers in these groups and to detect periodic points and their
behavior by looking at a particular diagram associated to an element.
  In the second part, we describe the structure of subgroups of the group of
all homeomorphisms of the unit circle, with the additional requirement that
they contain no non-abelian free subgroup. It is shown that in this setting the
rotation number map is a group homomorphism. We give a classification of such
subgroups as subgroups of certain wreath products and we show that such
subgroups can exist by building examples. Similar techniques are then used to
compute centralizers in these groups.


title: Some Explorations of New Physics Beyond The Standard Model

abstract:
  Some new physics beyond the Standard Model of particle physics, like
Supersymmetry, Extra-dimensions etc., and their effect on the nature of
different standard model phenomena are explored in this thesis. We discuss the
power law scaling of the gauge, Yuakawa and quartic scalar couplings in the
Universal Extra-Dimensional scenario assuming compactification on an $S^1/Z_2$
orbifold. We get a low unification scale around 30 TeV for a radius $R \sim 1
TeV^{-1}$. We show that the effect of one (two) extra-dimension(s) will allow
to relax the upper limit on the mass of the lightest CP-even neutral Higgs in
the minimal supersymmetric standard model upto around 200 GeV (300 GeV). We
obtain a low intermediate scale $(M_R)$, a desirable feature to accommodate
leptogenesis, within minimal supersymmetric SO(10) Grand Unified Theory with
the help of any one of three options -- threshold corrections,
non-renormalizable operators or presence of additional light Higgs multiplets.
In the triplet Higgs scalar model irrespective of these corrections, from the
perturbitivity requirement, we find a lower bound $M_R > 10^9$ GeV. On the
other hand remaining in the standard quark model we estimate the pentaquark
mass after taking care of the colour-spin symmetry properties for the triquark
$(qq\bar q)$ state.


title: Theory of the pairbreaking superconductor-metal transition in nanowires

abstract:
  We present a detailed description of a zero temperature phase transition
between superconducting and diffusive metallic states in very thin wires due to
a Cooper pair breaking mechanism. The dissipative critical theory contains
current reducing fluctuations in the guise of both quantum and thermally
activated phase slips. A full cross-over phase diagram is computed via an
expansion in the inverse number of complex components of the superconducting
order parameter (one in the physical case). The fluctuation corrections to the
direct current electrical and thermal conductivities are determined, and we
find that the electrical conductivity has a non-monotonic temperature
dependence in the metallic phase which may be consistent with recent
experimental results on ultra-narrow wires. In the quantum critical regime, the
ratio of the thermal to electrical conductivity displays a linear temperature
dependence and thus the Wiedemann-Franz law is obeyed, with a new universal
experimentally verifiable Lorenz number.


title: Polynomial functors and trees

abstract:
  We explore the relationship between polynomial functors and (rooted) trees.
In the first part we use polynomial functors to derive a new convenient
formalism for trees, and obtain a natural and conceptual construction of the
category $\Omega$ of Moerdijk and Weiss; its main properties are described in
terms of some factorisation systems. Although the constructions are motivated
and explained in terms of polynomial functors, they all amount to elementary
manipulations with finite sets. In the second part we describe polynomial
endofunctors and monads as structures built from trees, characterising the
images of several nerve functors from polynomial endofunctors and monads into
presheaves on categories of trees. Polynomial endofunctors and monads over a
base are characterised by a sheaf condition on categories of decorated trees.
In the absolute case, one further condition is needed, a certain projectivity
condition, which serves also to characterise polynomial endofunctors and monads
among (coloured) collections and operads.


title:
Characterization of Subgraphs Relationships and Distribution in Complex
  Networks

abstract:
  A network can be analyzed at different topological scales, ranging from
single nodes to motifs, communities, up to the complete structure. We propose a
novel intermediate-level topological analysis that considers non-overlapping
subgraphs (connected components) and their interrelationships and distribution
through the network. Though such subgraphs can be completely general, our
methodology focuses the cases in which the nodes of these subgraphs share some
special feature, such as being critical for the proper operation of the
network. Our methodology of subgraph characterization involves two main
aspects: (i) a distance histogram containing the distances calculated between
all subgraphs, and (ii) a merging algorithm, developed to progressively merge
the subgraphs until the whole network is covered. The latter procedure
complements the distance histogram by taking into account the nodes lying
between subgraphs, as well as the relevance of these nodes to the overall
interconnectivity. Experiments were carried out using four types of network
models and four instances of real-world networks, in order to illustrate how
subgraph characterization can help complementing complex network-based studies.


title: Stabilizer states and local realism

abstract:
  The central focus of this work is to make progress towards understanding
entanglement as a resource for computation by examining the quantum
correlations that can be extracted from stabilizer states. As such, we focus on
the stabilizer formalism, local realism, and the convergence of the two.


title:
Spreading of a liquid drop over a plane rigid substrate due to
  intermolecular forces

abstract:
  Self-similar solutions of the equation that describes spreading of a liquid
layer due to intermolecular forces are found. It is supposed that, when the
thickness of the layer reaches some magnitude of the order of the molecular
size, it turns into a monomolecular layer, which can be liquid or gaseous. To
describe the spreading of a drop, the solutions of the equations that describe
evolution of liquid or gaseous monomolecular layers are matched with the
self-similar solutions with using relevant boundary conditions.


title: A Singularity in the First-order PY Equation for a Square Well Fluid

abstract:
  It is shown that a nearest nieghbor Square Well (SW) potential leads to
singular behavior in first order. A solution of the first-order perturbative PY
equation for an attractive nearest neighbor square well of width less than the
core diameter reveals singular behavior. Neither the width of the well nor the
depth of the well affects the location of the singularity in the inverse
isothermal compressibility. The analysis is carried out in one dimension.


title: A PNJL model in 0+1 Dimensions

abstract:
  We formulate the Polyakov-Nambu-Jona-Lasinio (PNJL) model in 0+1 dimensions.
The thermodynamics captured by the partition function yields a bulk pressure,
as well as quark susceptibilities versus temperature that are similar to the
ones in 3+1 dimensions. Around the transition temperature the behavior in the
pressure and quark susceptibilities follows from the interplay between the
lowest Matsubara frequency and the Polyakov line. The reduction to the lowest
Matsubara frequency yields a matrix Model. In the presence of the Polyakov line
the UV part of the Dirac spectrum features oscillations when close to the
transition temperature.


title:
Beyond Nadel's Paradox. A computational approach to structural and
  cultural dimensions of social cohesion

abstract:
  Nadel's Paradox states that it is not possible to take into account
simultaneously cultural and relational dimensions of social structure. By means
of a simple computational model, the authors explore a dynamic perspective of
the concept of social cohesion that enables the integration of both structural
and cultural dimensions in the same analysis. The design of the model
reproduces a causal path from the level of conflict suffered by a population to
variations on its social cohesiveness, observed both from a structural and
cognitive viewpoint. Submitted to sudden variations on its environmental
conflict level, the model is able to reproduce certain characteristics
previously observed in real populations under situations of emergency or
crisis.


title: Generalized Long-Moody representations of braid groups

abstract:
  Long and Moody gave a method of constructing representations of the braid
group B_n. We discuss some ways to generalize their construction. One of these
gives representations of subgroups of B_n, including the Gassner representation
of the pure braid group as a special case. Another gives representations of the
Hecke algebra.


title: Nonlinear response of the vacuum Rabi resonance

abstract:
  On the level of single atoms and photons, the coupling between atoms and the
electromagnetic field is typically very weak. By employing a cavity to confine
the field, the strength of this interaction can be increased many orders of
magnitude to a point where it dominates over any dissipative process. This
strong-coupling regime of cavity quantum electrodynamics has been reached for
real atoms in optical cavities, and for artificial atoms in circuit QED and
quantum-dot systems. A signature of strong coupling is the splitting of the
cavity transmission peak into a pair of resolvable peaks when a single resonant
atom is placed inside the cavity - an effect known as vacuum Rabi splitting.
The circuit QED architecture is ideally suited for going beyond this linear
response effect. Here, we show that increasing the drive power results in two
unique nonlinear features in the transmitted heterodyne signal: the
supersplitting of each vacuum Rabi peak into a doublet, and the appearance of
additional peaks with the characteristic sqrt(n) spacing of the Jaynes-Cummings
ladder. These constitute direct evidence for the coupling between the quantized
microwave field and the anharmonic spectrum of a superconducting qubit acting
as an artificial atom.


title: A K-theoretic L2-index theorem for families

abstract: This paper has been withdrawn due to a error in Theorem 3.1.


title:
Atmospheric Calorimetry above 10$^{19}$ eV: Shooting Lasers at the
  Pierre Auger Cosmic-Ray Observatory

abstract:
  The Pierre Auger Cosmic-Ray Observatory uses the earth's atmosphere as a
calorimeter to measure extensive air-showers created by particles of
astrophysical origin. Some of these particles carry joules of energy. At these
extreme energies, test beams are not available in the conventional sense. Yet
understanding the energy response of the observatory is important. For example,
the propagation distance of the highest energy cosmic-rays through the cosmic
microwave background radiation (CMBR) is predicted to be strong function of
energy. This paper will discuss recently reported results from the observatory
and the use of calibrated pulsed UV laser "test-beams" that simulate the
optical signatures of ultra-high energy cosmic rays. The status of the much
larger 200,000 km$^3$ companion detector planned for the northern hemisphere
will also be outlined.


title: Quasi-reversible Magnetoresistance in Exchange Spring Tunnel Junctions

abstract:
  We report a large, quasi-reversible tunnel magnetoresistance in
exchange-biased ferromagnetic semiconductor tunnel junctions wherein a soft
ferromagnetic semiconductor (\gma) is exchange coupled to a hard ferromagnetic
metal (MnAs). Our observations are consistent with the formation of a region of
inhomogeneous magnetization (an "exchange spring") within the biased \gma
layer. The distinctive tunneling anisotropic magnetoresistance of \gma produces
a pronounced sensitivity of the magnetoresistance to the state of the exchange
spring.


title: AFM local oxidation nanolithography of graphene

abstract:
  We demonstrate the local oxidation nanopatterning of graphene films by an
atomic force microscope. The technique provides a method to form insulating
trenches in graphene flakes and to fabricate nanodevices with sub-nm precision.
We demonstrate fabrication of a 25-nm-wide nanoribbon and sub-micron size
nanoring from a graphene flake. We also found that we can write either trenches
or bumps on the graphene surface depending on the lithography conditions. We
attribute the bumps to partial oxidation of the surface and incorporation of
oxygen into the graphene lattice.


title:
Characterizing the intermediate phases of elastic networks through
  topological analysis

abstract:
  I review computational studies of different models of elastic network
self-organization leading to the existence of a globally isostatic (rigid but
unstressed) or nearly isostatic intermediate phase. A common feature of all
models considered here is that only the topology of the elastic network is
taken into account; this allows the use of an extremely efficient constraint
counting algorithm, the pebble game. In models with bond insertion without
equilibration, the intermediate phase is rigid with probability one but
stress-free; in models with equilibration, the network in the intermediate
phase is maintained in a self-organized critical state on the verge of
rigidity, fluctuating between percolating and nonpercolating but remaining
nearly isostatic. I also consider the connectivity analogs of these models,
some of which correspond to well-studied cases of loopless percolation and
where another kind of intermediate phase, with existing but nonpercolating
stress, was studied.


title: Trigonometric Darboux transformations and Calogero-Moser matrices

abstract:
  We characterize in terms of Darboux transformations the spaces in the
Segal-Wilson rational Grassmannian, which lead to commutative rings of
differential operators having coefficients which are rational functions of e^x.
The resulting subgrassmannian is parametrized in terms of trigonometric
Calogero-Moser matrices.


title:
Structure and Kinematics of the Broad-Line Region and Torus of Active
  Galactic Nuclei

abstract:
  Energetics considerations imply that the broad-line region (BLR) has a high
covering factor. The absence of absorption from the BLR means that the BLR has
to have a flattened distribution and be seen through a polar hole. The BLR is
the inward extension of the torus and they have similar geometries and covering
factors. Reconciling velocity-resolved reverberation mapping,
spectropolarimetry, and the increasing blueshifting of BLR lines with
decreasing distance from the centre, implies that the BLR has a significant
inflow component. This inflow provides the mass inflow rate needed to power the
AGN. We suggest that the mechanism producing the outward transport of angular
momentum necessary for the net inflow of the BLR is the magneto-rotational
instability, and that the BLR and outer accretion disc are one and the same.


title: Jumping sequences

abstract:
  An integer sequence a(n) is called a jump sequence if a(1)=1 and 1<=a(n)<n
for n>=2. Such a sequence has the property that a^k(n)=a(a(...(a(n))...)) goes
to 1 in finitely many steps and we call the pattern
(n,a(n),a^2(n),...,a^k(n)=1) a jumping pattern from n down to 1. In this paper
we look at jumping sequences which are weight minimizing with respect to
various weight functions (where a weight w(i,j) is given to each jump from j
down to i).
  Our main result is to show that if w(i,j)=(i+j)/i^2 then the cost minimizing
jump sequence has the property that the number m satisfies m=a^q(p) for
arbitrary q and some p (depending on q) if and only if m is a Pell number.


title: Testing the Copernican Principle via Cosmological Observations

abstract:
  Observations of distances to Type-Ia supernovae can be explained by
cosmological models that include either a gigaparsec-scale void, or a cosmic
flow, without the need for Dark Energy. Instead of invoking dark energy, these
inhomogeneous models instead violate the Copernican Principle. we show that
current cosmological observations (Supernovae, Baryon Acoustic Oscillations and
estimates of the Hubble parameters based on the age of the oldest stars) are
not able to rule out inhomogeneous anti-Copernican models. The next generation
of surveys for baryonic acoustic oscillations will be sufficiently precise to
either validate the Copernican Principle or determine the existence of a local
Gpc scale inhomogeneity.


title:
Slip-Squashing Factors as a Measure of Three-Dimensional Magnetic
  Reconnection

abstract:
  A general method for describing magnetic reconnection in arbitrary
three-dimensional magnetic configurations is proposed. The method is based on
the field-line mapping technique previously used only for the analysis of
magnetic structure at a given time. This technique is extended here so as to
analyze the evolution of magnetic structure. Such a generalization is made with
the help of new dimensionless quantities called "slip-squashing factors". Their
large values define the surfaces that border the reconnected or
to-be-reconnected magnetic flux tubes for a given period of time during the
magnetic evolution. The proposed method is universal, since it assumes only
that the time sequence of evolving magnetic field and the tangential boundary
flows are known. The application of the method is illustrated for simple
examples, one of which was considered previously by Hesse and coworkers in the
framework of the general magnetic reconnection theory. The examples help us to
compare these two approaches; they reveal also that, just as for magnetic null
points, hyperbolic and cusp minimum points of a magnetic field may serve as
favorable sites for magnetic reconnection. The new method admits a
straightforward numerical implementation and provides a powerful tool for the
diagnostics of magnetic reconnection in numerical models of solar-flare-like
phenomena in space and laboratory plasmas.


title:
Neuronal Shot Noise and Brownian $1/f^2$ Behavior in the Local Field
  Potential

abstract:
  We demonstrate that human electrophysiological recordings of the local field
potential (LFP) from intracranial electrodes, acquired from a variety of
cerebral regions, show a ubiquitous $1/f^2$ scaling within the power spectrum.
We develop a quantitative model that treats the generation of these fields in
an analogous way to that of electronic shot noise, and use this model to
specifically address the cause of this $1/f^2$ Brownian noise. The model gives
way to two analytically tractable solutions, both displaying Brownian noise: 1)
uncorrelated cells that display sharp initial activity, whose extracellular
fields slowly decay and 2) rapidly firing, temporally correlated cells that
generate UP-DOWN states.


title: Microscopic approach to current-driven domain wall dynamics

abstract:
  This review describes in detail the essential techniques used in microscopic
theories on spintronics. We have investigated the domain wall dynamics induced
by electric current based on the $s$-$d$ exchange model. The domain wall is
treated as rigid and planar and is described by two collective coordinates: the
position and angle of wall magnetization. The effect of conduction electrons on
the domain wall dynamics is calculated in the case of slowly varying spin
structure (close to the adiabatic limit) by use of a gauge transformation. The
spin-transfer torque and force on the wall are expressed by Feynman diagrams
and calculated systematically using non-equilibrium Green's functions, treating
electrons fully quantum mechanically. The wall dynamics is discussed based on
two coupled equations of motion derived for two collective coordinates. The
force is related to electron transport properties, resistivity, and the Hall
effect. Effect of conduction electron spin relaxation on the torque and wall
dynamics is also studied.


title: Wavelength Shifters for Water Cherenkov Detectors

abstract:
  The light yield of a water-based Cherenkov detector can be significantly
improved by adding a wavelength shifter. Wavelength shifter (WLS) molecules
absorb ultraviolet photons and re-emit them at longer wavelengths where typical
photomultiplier tubes are more sensitive. In this study, several wavelength
shifter compounds are tested for possible deployment in the Sudbury Neutrino
Observatory (SNO). Test results on optical properties and chemical
compatibility for a few WLS candidates are reported; together with timing and
gain measurements. A Monte Carlo simulation of the SNO detector response is
used to estimate the total light gain with WLS. Finally, a cosmic ray Cherenkov
detector was built to investigate the optical properties of WLS.


title:
Quantized Berry Phases of a Spin-1/2 Frustrated Two-Leg Ladder with
  Four-Spin Exchange

abstract:
  A spin-1/2 frustrated two-leg ladder with four-spin exchange interaction is
studied by quantized Berry phases. We found that the Berry phase successfully
characterizes the Haldane phase in addition to the rung-singlet phase, and the
dominant vector-chirality phase. The Hamiltonian of the Haldane phase is
topologically identical to the S=1 antiferromagnetic Heisenberg chain.
Decoupled models connected to the dominant vector-chirality phase revealed that
the local object identified by the non-trivial ($\pi$) Berry phase is the
direct product of two diagonal singlets.


title: A New Holographic Model of Chiral Symmetry Breaking

abstract:
  A new family of models of flavour chiral symmetry breaking is proposed. The
models are based on the embedding of a stack of D7-branes and a stack of anti
D7-branes in the conifold background. This family of gravity models is dual to
a field theory with spontaneous breaking of conformal invariance and chiral
flavour symmetry. We identify the corresponding Goldstone bosons and compute
the spectra of massive scalar and vector mesons. The dual quiver gauge theory
is also discussed. We further analyse a model where chiral symmetry is not
broken.


title:
Heavily Damped Motion of One-Dimensional Bose Gases in an Optical
  Lattice

abstract:
  We study the dynamics of strongly correlated one-dimensional Bose gases in a
combined harmonic and optical lattice potential subjected to sudden
displacement of the confining potential. Using the time-evolving block
decimation method, we perform a first-principles quantum many-body simulation
of the experiment of Fertig {\it et al.} [Phys. Rev. Lett. {\bf 94}, 120403
(2005)] across different values of the lattice depth ranging from the
superfluid to the Mott insulator regimes. We find good quantitative agreement
with this experiment: the damping of the dipole oscillations is significant
even for shallow lattices, and the motion becomes overdamped with increasing
lattice depth as observed. We show that the transition to overdamping is
attributed to the decay of superfluid flow accelerated by quantum fluctuations,
which occurs well before the emergence of Mott insulator domains.


title: First detection of CO lines in a water fountain star

abstract:
  [Context] Water fountain stars are very young post-AGB stars with high
velocity water maser jets. They are the best objects to study the onset of
bipolar jets from evolved stars due to their young dynamical ages. [Methods] We
use the Arizona Radio Observatory 10m telescope to observe the CO J=2-1 line
and compare the line parameters with that of masers. [Results] We report the
detection of 12CO and 13COJ=2-1 lines from IRAS 16342-3814. The inferred 12CO
mass loss rate is an order of magnitude lower than the infrared and OH mass
loss rates, indicating a very cold and thick O-rich circumstellar envelope
around the star. We also find a 12CO expansion velocity of Vexp = 46 +- 1 km/s
that is too high for an AGB wind and confirm the systemic velocity of 44 +- 1
km/s. In addition we measure a very low 12CO/13CO line ratio of 1.7.
[Conclusions] The first detection of CO lines has provided a new way to
investigate the water fountain stars. Given the high expansion velocity of the
CO gas and its relation to maser velocities, we infer that the CO emission
region is co-located with the OH mainline masers in the warm base of the
optical bipolar lobes, while the high velocity OH1612MHz and H2O masers are
located in the side walls and at the farthest ends of the bipolar lobes,
respectively. Further observations are highly desired to understand the very
low 12CO/13CO line ratio.


title: Exploiting Low-Dimensional Structure in Astronomical Spectra

abstract:
  Dimension-reduction techniques can greatly improve statistical inference in
astronomy. A standard approach is to use Principal Components Analysis (PCA).
In this work we apply a recently-developed technique, diffusion maps, to
astronomical spectra for data parameterization and dimensionality reduction,
and develop a robust, eigenmode-based framework for regression. We show how our
framework provides a computationally efficient means by which to predict
redshifts of galaxies, and thus could inform more expensive redshift estimators
such as template cross-correlation. It also provides a natural means by which
to identify outliers (e.g., misclassified spectra, spectra with anomalous
features). We analyze 3835 SDSS spectra and show how our framework yields a
more than 95% reduction in dimensionality. Finally, we show that the prediction
error of the diffusion map-based regression approach is markedly smaller than
that of a similar approach based on PCA, clearly demonstrating the superiority
of diffusion maps over PCA for this regression task.


title: Current-induced dynamics of spiral magnet

abstract:
  We study the dynamics of the spiral magnet under the charge current by
solving the Landau-Lifshitz-Gilbert equation numerically. In the steady state,
the current ${\vec j}$ induces (i) the parallel shift of the spiral pattern
with velocity $v=(\beta/\alpha)j$ ($\alpha$, $\beta$: the Gilbert damping
coefficients), (ii) the uniform magnetization $M$ parallel or anti-parallel to
the current depending on the chirality of the spiral and the ratio $\beta /
\alpha $, and (iii) the change in the wavenumber $k$ of the spiral. These are
analyzed by the continuum effective theory using the scaling argument, and the
various nonequilibrium phenomena such as the chaotic behavior and
current-induced annealing are also discussed.


title: Complexity of Quantum States and Reversibility of Quantum Motion

abstract:
  We present a quantitative analysis of the reversibility properties of
classically chaotic quantum motion. We analyze the connection between
reversibility and the rate at which a quantum state acquires a more and more
complicated structure in its time evolution. This complexity is characterized
by the number ${\cal M}(t)$ of harmonics of the (initially isotropic, i.e.
${\cal M}(0)=0$) Wigner function, which are generated during quantum evolution
for the time $t$. We show that, in contrast to the classical exponential
increase, this number can grow not faster than linearly and then relate this
fact with the degree of reversibility of the quantum motion. To explore the
reversibility we reverse the quantum evolution at some moment $T$ immediately
after applying at this moment an instant perturbation governed by a strength
parameter $\xi$. It follows that there exists a critical perturbation strength,
$\xi_c\approx \sqrt{2}/{\cal M}(T)$, below which the initial state is well
recovered, whereas reversibility disappears when $\xi\gtrsim \xi_c(T)$. In the
classical limit the number of harmonics proliferates exponentially with time
and the motion becomes practically irreversible. The above results are
illustrated in the example of the kicked quartic oscillator model.


title: Degeneracies in the length spectra of metric graphs

abstract:
  The spectral theory of quantum graphs is related via an exact trace formula
with the spectrum of the lengths of periodic orbits (cycles) on the graphs. The
latter is a degenerate spectrum, and understanding its structure (i.e.,finding
out how many different lengths exist for periodic orbits with a given period
and the average number of periodic orbits with the same length) is necessary
for the systematic study of spectral fluctuations using the trace formula. This
is a combinatorial problem which we solve exactly for complete (fully
connected) graphs with arbitrary number of vertices.


title:
Comment on "Electronic structure and orbital ordering of
  SrRu$_{1-x}$Ti$_x$O$_3$: GGA+U investigations"

abstract:
  In the paper, PRB {\bf 77}, 085118 (2008), the authors conclude that the
observation of Ti-doping induced half-metallicity in SrRu$_{1-x}$TI$_x$O$_3$
within the limit of local density approximations is not valid as the
experimental results indicate insulating behavior. It was described that the
metal-insulator transition (MIT) at x = 0.5 observed in this system appears due
to the enhancement of on-site Coulomb repulsion strength, U with Ti
substitutions, x. The MIT primarily depends on U and partially on x and/or
disorder. All these conclusions are in sharp contrast to the experimental
observations, which predicted Anderson insulating phase at x = 0.5 (finite
localized density of states at the Fermi level). The hard gap due to electron
correlation appears at much higher x (~ 0.8). In addition, it is well
established that homovalent substitution has negligible influence on on-site
$U$ (a local variable). These inconsistencies appear due to the fact that the
calculated results representing the bulk electronic structure are compared with
the experimental results dominated by surface contributions. The experimental
bulk spectra, already available in the literature exhibit finite density of
states at the Fermi level even for x >= 0.5 sample, which suggests that the
conclusion of half metallic phase in an earlier study is reasonable. Thus, the
insulator to metal transition in these systems is driven by bandwidth, W rather
than U and disorder plays dominant role in the metal-insulator transition. One
needs to consider the bulk spectra to reproduce numerically the bulk electronic
structure.


title:
Precision measurement of the branching fractions of the 4P3/2 decay of
  Ca II

abstract:
  We perform precision measurements of the branching ratios of the 4P3/2 level
decay of a single 40Ca+ ion suspended in a linear Paul trap. High precision is
achieved by a novel technique based on monitoring the population transfer when
repeatedly pumping the ion between different internal states. The branching
fractions into the 4S1/2, 3D5/2 and 3D3/2 levels are found to be 0.9347(3),
0.0587(2) and 0.00661(4), respectively. For the branching ratio
A(P3/2-S1/2)/\sum_J A(P3/2-D_J)=14.31(5), we find a forty-fold improvement in
accuracy as compared to the best previous measurement.


title: Fermi gas energetics in low-dimensional metals of spessial geometry

abstract:
  Changes in the metal properties, caused by periodic indents in the metal
surface, have been studied within the limit of quantum theory of free
electrons. It was shown that due to destructive interference of de Broglie
waves, some quantum states inside the low-dimensional metal become quantum
mechanically forbidden for free electrons. Wave vector density in k space,
reduce dramatically. At the same time, number of free electrons does not
change, as metal remains electrically neutral. Because of Pauli exclusion
principle some free electrons have to occupy quantum states with higher wave
numbers. Fermi vector and Fermi energy of low-dimensional metal increase and
consequently its work function decrease. In experiment, magnitude of the effect
is limited by the roughness of metal surface. Rough surface causes scattering
of the de Broglie waves and compromise their interference. Recent experiments
demonstrated reduction of work function in thin metal films, having periodic
indents in the surface. Experimental results are in good qualitative agreement
with the theory. This effect could exist in any quantum system comprising
fermions inside a potential energy box of special geometry.


title:
Linearly repetitive Delone systems have a finite number of non periodic
  Delone system factors

abstract:
  We prove linearly repetitive Delone systems have finitely many Delone system
factors up to conjugacy. This result is also applicable to linearly repetitive
tiling systems.


title: Charge-statistics separation and probing non-Abelian states

abstract:
  Several states were proposed as candidates for the $\nu=5/2$ quantum Hall
plateau. We suggest an experiment which can determine the physical state. The
proposal involves transport measurements in the geometry with three quantum
Hall edges connected by two quantum point contacts. In contrast to interference
experiments, this approach can distinguish the Pfaffian and anti-Pfaffian
states as well as different states with identical Pfaffian or anti-Pfaffian
statistics. The transport is not sensitive to the fluctuations of the number of
the quasiparticles trapped in the system.


title: Aberration cancellation in quantum interferometry

abstract:
  We report the first experimental demonstration of even-order aberration
cancellation in quantum interferometry. The effect is a spatial counterpart of
the spectral group velocity dispersion cancellation, which is associated with
spectral entanglement. It is manifested in temporal interferometry by virtue of
the multi-parameter spatial-spectral entanglement. Spatially-entangled photons,
generated by spontaneous parametric down conversion, were subjected to spatial
aberrations introduced by a deformable mirror that modulates the wavefront. We
show that only odd-order spatial aberrations affect the quality of quantum
interference.


title:
A jet model for Galactic black-hole X-ray sources: Some constraining
  correlations

abstract:
  Some recent observational results impose significant constraints on all the
models that have been proposed to explain the Galactic black-hole X-ray sources
in the hard state. In particular, it has been found that during the hard state
of Cyg X-1 the power-law photon number spectral index is correlated with the
average time lag between hard and soft X-rays. Furthermore, the peak
frequencies of the four Lorentzians that fit the observed power spectra are
correlated with both the photon index and the time lag. We performed Monte
Carlo simulations of Compton upscattering of soft, accretion-disk photons in
the jet and computed the time lag between hard and soft photons and the
power-law index of the resulting photon number spectra. We demonstrate that our
jet model naturally explains the above correlations, with no additional
requirements and no additional parameters.


title:
Constraints on $w_0$ and $w_a$ of Dark Energy from High Redshift Gamma
  Ray Bursts

abstract:
  We extend the Hubble diagram up to $z = 5.6$ using 63 gamma-ray bursts (GRBs)
via peak energy-peak luminosity relation (so called Yonetoku relation), and
obtain constraints on cosmological parameters including dynamical dark energy
parametrized by $P/\rho\equiv w(z) = w_0 + w_a \cdot z/(1+z)$. It is found that
the current GRB data are consistent with the concordance model, ($\Omega_m =
0.28, \Omega_{\Lambda} = 0.72, w_0 = -1, w_a = 0$), within two sigma level.
Although constraints from GRBs themselves are not so strong, they can improve
the conventional constraints from SNeIa because GRBs have much higher
redshifts. Further we estimate the constraints on the dark-energy parameters
expected by future observations with GLAST (Gamma-ray Large Area Space
Telescope) and \swift by Monte-Carlo simulation. Constraints would improve
substantially with another 150 GRBs.


title:
Electronic structure of Fe (0-5 at. %) doped MoO2 thin films studied by
  resonant photoemission spectroscopy

abstract:
  The electronic structure of pulsed laser deposited Mo1-xFexO2 (x=0, 0.02 and
0.05) thin films has been investigated using resonant photoemission
spectroscopy near Mo-4p absorption edge. In all the samples a broad Fano- like
resonance peak at ~46 eV is observed in the whole area of the valence band
which indicates the contribution of the Mo-4d states in the entire valence band
region. The doping of Fe in these films leads to decrease in Mo 4d states
contributing to electronic states at lower binding energy region. In addition
to this, we also observe a shoulder at 4.9 eV in the valence band spectra of
doped samples. It is proposed that the origin of this shoulder is due to the Fe
hybridised states.


title:
Role of the $N^*$(1535) in the $J/\psi\to \bar{p}\eta p$ and $J/\psi\to
  \bar{p}K^+\Lambda$ reactions

abstract:
  We study the $J/\psi\to \bar{p}\eta p$ and $J/\psi\to \bar{p}K^+\Lambda$
reactions with a unitary chiral approach. We find that the unitary chiral
approach, which generates the $N^*(1535)$ dynamically, can describe the data
reasonably well, particularly the ratio of the integrated cross sections. This
study provides further support for the unitary chiral description of the
$N^*(1535)$. We also discuss some subtle differences between the coupling
constants determined from the unitary chiral approach and those determined from
phenomenological studies.


title:
Coupled-channel evaluations of cross sections for scattering involving
  particle-unstable resonances

abstract:
  How does the scattering cross section change when the colliding bound-state
fragments are allowed particle-emitting resonances? This question is explored
in the framework of a multi-channel algebraic scattering method of determining
nucleon-nucleus cross sections at low energies. Two cases are examined, the
first being a gedanken investigation in which n + carbon-12 scattering is
studied with the target states assigned artificial widths. The second is a
study of neutron scattering from beryllium-8; a nucleus that is particle
unstable. Resonance character of the target states markedly varies evaluated
cross sections from those obtained assuming stability in the target spectrum.


title: Electromagnetic radiation, motion of a particle and energy-mass relation

abstract:
  Equation of motion of an uncharged arbitrarily shaped dust particle under the
effects of (stellar) electromagnetic radiation and thermal emission is derived.
The resulting relativistically covariant equation of motion is expressed in
terms of standard optical parameters. Relations between energy and mass of the
incoming and outgoing radiation are obtained, together with relations between
radiation energy and mass of the particle. The role of the diffraction nicely
fits the relativistic formulation of the momentum of the outgoing radiation.
  The inequality 0 < $\bar{Q}'_{pr, 1} / \bar{Q}'_{ext}$ < 2 is a simple
relativistic consequence for the Poynting-Robertson (P-R) effect
($\bar{Q}'_{ext}$ and $\bar{Q}'_{pr, 1}$ are dimensionless efficiency factors
for the extinction and radial direction of the radiation pressure, integrated
over stellar spectrum). The condition for the P-R effect is $\vec{p}'_{o}$ = (1
- $\bar{Q}'_{pr, 1} / \bar{Q}'_{ext}$) $\vec{p}'_{i}$, where $\vec{p}'_{i}$ and
$\vec{p}'_{o}$ are incoming and outgoing radiation momenta (per unit time)
measured in the proper frame of reference of the particle. The case of
"perfectly absorbing spherical dust particle", within geometrical optics
approximation, corresponds to the condition $\vec{p}'_{o}$ = 0.5
$\vec{p}'_{i}$. As for arbitrarily shaped dust particle, the condition 0 <
$\bar{C}'_{pr, 1}$ / $\bar{C}'_{ext}$ < 2 / ($1 ~+~ \sum_{j=2}^{3}
\bar{C}'_{pr, j} / \bar{C}'_{pr, 1}$) holds for cross sections of extinction
and radiation pressure components. The condition can add a new information to
the results obtained from observations, measurements and numerical calculations
of the optical properties of the particle.


title:
Scattering norm estimate near the threshold for energy-critical focusing
  semilinear wave equation

abstract:
  We consider the energy-critical semilinear focusing wave equation in
dimension $N=3,4,5$. An explicit solution $W$ of this equation is known. By the
work of C. Kenig and F. Merle, any solution of initial condition $(u_0,u_1)$
such that $E(u_0,u_1)<E(W,0)$ and $\|\nabla u_0\|_{L^2}<\|\nabla W\|_{L^2}$ is
defined globally and has finite $L^{\frac{2(N+1)}{N-2}}_{t,x}$-norm, which
implies that it scatters. In this note, we show that the supremum of the
$L^{\frac{2(N+1)}{N-2}}_{t,x}$-norm taken on all scattering solutions at a
certain level of energy below $E(W,0)$ blows-up logarithmically as this level
approaches the critical value $E(W,0)$. We also give a similar result in the
case of the radial energy-critical focusing semilinear Schr\"odinger equation.
The proofs rely on the compactness argument of C. Kenig and F. Merle, on a
classification result, due to the authors, at the energy level $E(W,0)$, and on
the analysis of the linearized equation around $W$.


title:
QCD Vacuum Properties in a Magnetic Field from AdS/CFT: Chiral
  Condensate and Goldstone Mass

abstract:
  Chiral condensate and $\eta^\prime$ meson mass spectrum are studied under the
influence of an external Abelian magnetic field. We work within the D3/D7
Karch--Katz model of flavoured AdS/CFT with supersymmetry broken by the
Constable--Myers deformation of the metric. It is shown that this setting
yields a quadratic dependence of condensate on field, rather than the
non-analytic (linear in field) dependence, typical for chiral perturbation
theory in the exact chiral limit. We argue that the analytic (quadratic) result
must be put into correspondence with the leading-order in the $1/N_c$
decomposition for the condensate, whereas the existing chiral perturbation
theory result, which is linear in field strength, is $1/N_c$ suppressed.


title: Wigner symmetry, Large Nc and Renormalized One Boson Exchange Potential

abstract:
  Wigner symmetry in Nuclear Physics provides a unique example of a
non-perturbative long distance symmetry, a symmetry strongly broken at short
distances. We analyse the consequences of such a concept within the framework
of One Boson Exchange Potentials in NN scattering and keeping the leading Nc
contributions. Phenomenologically successful relations between singlet 1S0 and
triplet 3S1 scattering phase shifts are provided in the entire elastic region.
We establish symmetry breaking relations among non-central phase shifts which
are successfully fulfilled by even-L partial waves and strongly violated by
odd-L partial waves, in full agreement with large Nc requirements.


title: Molecular Gas and Star formation in ARP 302

abstract:
  We present the Submillimeter Array observation of the CO J=2-1 transition
towards the northern galaxy, ARP 302N, of the early merging system, ARP 302.
Our high angular resolution observation reveals the extended spatial
distribution of the molecular gas in ARP 302N. We find that the molecular gas
has a very asymmetric distribution with two strong concentrations on either
side of the center together with a weaker one offset by about 8 kpc to the
north. The molecular gas distribution is also found to be consistent with that
from the hot dust as traced by the 24 micro continuum emission observed by the
Spitzer. The line ratio of CO J=2-1/1-0 is found to vary strongly from about
0.7 near the galaxy center to 0.4 in the outer part of the galaxy. Excitation
analysis suggests that the gas density is low, less than 10$^3$ cm$^{-3}$, over
the entire galaxy. By fitting the SED of ARP 302N in the far infrared we obtain
a dust temperature of $T\rm_d$=26-36 K and a dust mass of M$\rm
_{dust}$=2.0--3.6$\times10^8$ M$\rm_\odot$. The spectral index of the radio
continuum is around 0.9. The spatial distribution and spectral index of the
radio continuum emission suggests that most of the radio continuum emission is
synchrotron emission from the star forming regions at the nucleus and
ARP302N-cm. The good spatial correspondance between the 3.6 cm radio continuum
emission, the Spitzer 8 & 24 $\mu$m data and the high resolution CO J=2-1
observation from the SMA shows that there is the asymmetrical star forming
activities in ARP 302N.


title:
Monolithic Active Pixel Sensors (MAPS) in a quadruple well technology
  for nearly 100% fill factor and full CMOS pixels

abstract:
  In this paper we present a novel, quadruple well process developed in a
modern 0.18mu CMOS technology called INMAPS. On top of the standard process, we
have added a deep P implant that can be used to form a deep P-well and provide
screening of N-wells from the P-doped epitaxial layer. This prevents the
collection of radiation-induced charge by unrelated N-wells, typically ones
where PMOS transistors are integrated. The design of a sensor specifically
tailored to a particle physics experiment is presented, where each 50mu pixel
has over 150 PMOS and NMOS transistors. The sensor has been fabricated in the
INMAPS process and first experimental evidence of the effectiveness of this
process on charge collection is presented, showing a significant improvement in
efficiency.


title: Thinking transport as a twist

abstract:
  The determination of the conductivity of a deterministic or stochastic
classical system coupled to reservoirs at its ends can in general be mapped
onto the problem of computing the stiffness (the `energy' cost of twisting the
boundaries) of a quantum-like operator. The nature of the coupling to the
reservoirs determines the details of the mechanical coupling of the torque at
the ends.


title: Electromagnetic form factors of the Delta in a S-wave approach

abstract:
  Without any further adjusting of parameters, a relativistic constituent quark
model, successful in the description of the data for the nucleon elastic form
factors and of the dominant contribution for the nucleon to Delta
electromagnetic transition, is used here to predict the dominant
electromagnetic form factors of the Delta baryon. The model is based on a
simple Delta wave function corresponding to a quark-diquark system in an
S-state. The results for E0 and M1 are consistent both with experimental
results and lattice calculations. The remaining form factors E2 and M3 vanish,
given the symmetric structure taken for the Delta.


title:
Polarized superfluidity in the attractive Hubbard model with population
  imbalance

abstract:
  We study a two-component Fermi system with attractive interactions and
different populations of the two species in a cubic lattice. For an
intermediate coupling we find a uniformly polarized superfluid which is stable
down to very low temperatures. The momentum distribution of this phase closely
resembles that of the Sarma phase, characterized by two Fermi surfaces. This
phase is shown to be stabilized by a potential energy gain, as in a BCS
superfluid, in contrast to the unpolarized BEC which is stabilized by kinetic
energy. We present general arguments suggesting that preformed pairs in the
unpolarized superfluid favor the stabilization of a polarized superfluid phase.


title: Coverings, correspondences, and noncommutative geometry

abstract:
  We construct an additive category where objects are embedded graphs in the
3-sphere and morphisms are geometric correspondences given by 3-manifolds
realized in different ways as branched covers of the 3-sphere, up to branched
cover cobordisms. We consider dynamical systems obtained from associated
convolution algebras endowed with time evolutions defined in terms of the
underlying geometries. We describe the relevance of our construction to the
problem of spectral correspondences in noncommutative geometry.


title: Depth Two Hopf Subalgebras of Semisimple Hopf algebras

abstract:
  Let H be a finite dimensional semisimple Hopf algebra over an algebraically
closed field of characteristic zero. In this note we give a short proof of the
fact that a Hopf subalgebra of H is a depth two subalgebra if and only if it is
normal Hopf subalgebra.


title: Solar neutrino limit on axions and keV-mass bosons

abstract:
  The all-flavor solar neutrino flux measured by the Sudbury Neutrino
Observatory (SNO) constrains nonstandard energy losses to less than about 10%
of the Sun's photon luminosity, superseding a helioseismological argument and
providing new limits on the interaction strength of low-mass particles. For the
axion-photon coupling strength we find g_a\gamma < 7E-10 1/GeV. We also derive
explicit limits on the Yukawa coupling to electrons of pseudoscalar, scalar and
vector bosons with keV-scale masses.


title: Completeness of dagger-categories and the complex numbers

abstract:
  The complex numbers are an important part of quantum theory, but are
difficult to motivate from a theoretical perspective. We describe a simple
formal framework for theories of physics, and show that if a theory of physics
presented in this manner satisfies certain completeness properties, then it
necessarily includes the complex numbers as a mathematical ingredient. Central
to our approach are the techniques of category theory, and we introduce a new
category-theoretical tool, called the dagger-limit, which governs the way in
which systems can be combined to form larger systems. These dagger-limits can
be used to characterize the dagger-functor on the category of
finite-dimensional Hilbert spaces, and so can be used as an equivalent
definition of the inner product. One of our main results is that in a
nontrivial monoidal dagger-category with all finite dagger-limits and a simple
tensor unit, the semiring of scalars embeds into an involutive field of
characteristic 0 and orderable fixed field.


title: Visual Grouping by Neural Oscillators

abstract:
  Distributed synchronization is known to occur at several scales in the brain,
and has been suggested as playing a key functional role in perceptual grouping.
State-of-the-art visual grouping algorithms, however, seem to give
comparatively little attention to neural synchronization analogies. Based on
the framework of concurrent synchronization of dynamic systems, simple networks
of neural oscillators coupled with diffusive connections are proposed to solve
visual grouping problems. Multi-layer algorithms and feedback mechanisms are
also studied. The same algorithm is shown to achieve promising results on
several classical visual grouping problems, including point clustering, contour
integration and image segmentation.


title:
A Family of Multistep Methods with Zero Phase-Lag and Derivatives for
  the Numerical Integration of Oscillatory ODEs

abstract:
  In this paper we develop a family of three 8-step methods, optimized for the
numerical integration of oscillatory ordinary differential equations. We have
nullified the phase-lag of the methods and the first r derivatives, where
r=1,2,3. We show that with this new technique, the method gains efficiency with
each derivative of the phase-lag nullified. This is the case for the
integration of both the Schrodinger equation and the N-body problem. A local
truncation error analysis is performed, which, for the case of the Schrodinger
equation, also shows the connection of the error and the energy, revealing the
importance of the zero phase-lag derivatives. Also the stability analysis shows
that the methods with more derivatives vanished, have a bigger interval of
periodicity.


title: Comportement asymptotique des hauteurs des points de Heegner

abstract:
  The leading order term for the average, over quadratic discriminants
satisfying the so-called Heegner condition, of the Neron-Tate height of Heegner
points on a rational elliptic curve E has been determined in [12]. In addition,
the second order term has been conjectured. In this paper, we prove that this
conjectured second order term is the right one; this yields a power saving in
the remainder term. Cancellations of Fourier coefficients of GL(2)-cusp forms
in arithmetic progressions lie in the core of the proof.


title: Learning from Experts: A Survey

abstract:
  The survey is concerned with the issue of information transmission from
experts to non-experts. Two main approaches to the use of experts can be
traced. According to the game-theoretic approach expertise is a case of
asymmetric information between the expert, who is the better informed agent,
and the non-expert, who is either a decision-maker or an evaluator of the
expert's performance. According to the Bayesian decision-theoretic approach the
expert is the agent who announces his probabilistic opinion, and the non-expert
has to incorporate that opinion into his beliefs in a consistent way, despite
his poor understanding of the expert's substantive knowledge. The two
approaches ground the relationships between experts and non-experts on so
different premises that their results are very poorly connected.


title: Codimension one subgroups and boundaries of hyperbolic groups

abstract:
  We construct hyperbolic groups with the following properties: The boundary of
the group has big dimension, it is separated by a Cantor set and the group does
not split. This shows that Bowditch's theorem that characterizes splittings of
hyperbolic groups over 2-ended groups in terms of the boundary can not be
extended to splittings over more complicated subgroups.


title: Cooling dynamics of pure and random Ising chains

abstract:
  Dynamics of quenching temperature is studied in pure and random Ising chains.
Using the Kibble-Zurek argument, we obtain for the pure Ising model that the
density of kinks after quenching decays as 1/\sqrt{\tau} with the quench rate
of temperature 1/\tau for large \tau. For the random Ising model, we show that
decay rates of the density of kinks and the residual energy are 1/\ln\tau and
1/(\ln\tau)^2 for large \tau respectively. Analytic results for the random
Ising model are confirmed by the Monte-Carlo simulation. Our results reveal a
clear difference between classical and quantum quenches in the random Ising
chain.


title: On Blocking Numbers of Surfaces

abstract:
  The blocking number of a manifold is the minimal number of points needed to
block out lights between any two given points in the manifold. It has been
conjectured that if the blocking number of a manifold is finite, then the
manifold must be flat. In this paper we prove that this is true for
2-dimensional manifolds with non-trivial fundamental groups.


title:
Optical properties of ZnCr2Se4 - Spin-phonon coupling and electronic
  d-d-like excitations

abstract:
  We studied the optical properties of antiferromagnetic ZnCr2Se4 by infrared
spectroscopy up to 28,000 cm-1 and for temperatures from 5 to 295 K. At the
magnetic phase transition at 21 K, one of the four phonon modes reveals a clear
splitting of 3 cm-1 as a result of spin-phonon coupling, the other three
optical eigenmodes only show shifts of the eigenfrequencies. The
antiferromagnetic ordering and the concomitant splitting of the phonon mode can
be suppressed in a magnetic field of 7 T. At higher energies we observed a
broad excitation band which is dominated by a two-peak-structure at about
18,000 cm-1 and 22,000 cm-1, respectively. These energies are in good agreement
with the expected spin-allowed crystal-field transition of the Cr3+ ions. The
unexpected strength of these forbidden onsite d-d transitions is attributed to
a considerable hybridization of the selenium p with the chromium d orbitals.


title: The dipole-quadrupole theory of surface-enhanced Raman scattering

abstract:
  The review is devoted to explanation of SERS in terms of the dipole and
quadrupole light-molecule interactions arising in surface fields strongly
varying in space in the region of the strongly irregular surface roughness. The
main SERS characteristics, the theory of electromagnetic fields near some model
kinds of rough surfaces and some other systems, the theory of SERS Raman tensor
for arbitrary and symmetrical molecules, selection rules and analysis of the
SER spectra, some anomalies in the SER spectra of symmetrical molecules for
some specific conditions, electrodynamic forbiddance of the quadrupole
scattering mechanism for the methane molecule and molecules with cubic symmetry
groups are considered. The huge enhancement and blinking of the SERS signal
arising in the phenomenon of Single Molecule detection by the SERS method are
explained. The above theory is compared with some another SERS mechanisms, and
the phenomena accompanying SERS are accounted for. It is demonstrated that the
theory is in a good agreement with the experiment and explains quite a number
of characteristics related to the SERS phenomenon.


title:
Evolution of self-assembled InAs/Gas(001) quantum dots grown by
  growth-interrupted molecular beam epitaxy

abstract:
  Self-assembled InAs quantum dots (QDs) grown on GaAs(001) surface by
molecular beam epitaxy under continuous and growth-interruption modes exhibit
two families of QDs, quasi-3D (Q3D) and 3D QDs, whose volume density evolution
is quantitatively described by a rate-equation kinetic model. The volume
density of small Q3D QDs decreases exponentially with time during the
interruption, while the single-dot mean volume of the large QDs increases by
Ostwald ripening. The kinetics of growth involves conversion of quasi-3D to 3D
QDs at a rate determined by superstress and participation of the wetting layer
adatoms. The data analysis excludes that quasi-3D QDs are extrinsic surface
features due to inefficient cooling after growth.


title: Rippling of Graphene

abstract:
  Meyer et al (2007) found that free-standing graphene sheets, just one atom
thick, display spontaneous ripples. The ripples are of order 2-20 {\AA} high
and 20-200 {\AA} wide. The sheets in which they appear are only one atom thick,
and extend for around 5000 {\AA} through vacuum between metal struts that
support them. Other groups have since created free-standing graphene as well
(Garcia-Sanchez 2008 ; Bolotin et al. 2008), and similar ripples have been
found for graphene on a glass substrate (Geringer et al. 2008). Here we show
that these ripples can be explained as a consequence of adsorbed molecules
sitting on random sites. The adsorbates cause the bonds between carbon atoms to
lengthen slightly. Static buckles then result from a mechanism like the one
that leads to buckling of leaves; buckles caused by roughly 20% coverage of
adsorbates are consistent with experimental observations. We explain why this
mechanism is more likely to explain rippled than thermal fluctuations or the
Mermin-Wagner theorem, which have previously been invoked.


title: Phase Lag Sensitivity Analysis for Numerical Integration

abstract:
  In the field of numerical integration, methods specially tuned on oscillating
functions, are of great practical importance. Such methods are needed in
various branches of natural sciences, particularly in physics, since a lot of
physical phenomena exhibit a pronounced oscillatory behavior. Among others,
probably the most important tool used to construct efficient methods for
oscillatory problems is the exponential (trigonometric) fitting. The basic
characteristic of these methods is that their phase lag vanishes at a
predefined frequency. In this work, we introduce a new tool which improves the
behavior of exponentially fitted numerical methods. The new technique is based
on the vanishing of the first derivatives of the phase lag function at the
fitted frequency. It is proved in the text that these methods present improved
characteristics in oscillatory problems.


title:
On the commutant of $C(X)$ in $C^*$-crossed products by $\mathbb{Z}$ and
  their representations

abstract:
  For the $C^*$-crossed product $C^*(\Sigma)$ associated with an arbitrary
topological dynamical system $\Sigma = (X, \sigma)$, we provide a detailed
analysis of the commutant, in $C^* (\Sigma)$, of $C(X)$ and the commutant of
the image of $C(X)$ under an arbitrary Hilbert space representation
$\tilde{\pi}$ of $C^* (\Sigma)$. In particular, we give a concrete description
of these commutants, and also determine their spectra. We show that, regardless
of the system $\Sigma$, the commutant of $C(X)$ has non-zero intersection with
every non-zero, not necessarily closed or self-adjoint, ideal of $C^*
(\Sigma)$. We also show that the corresponding statement holds true for the
commutant of $\tilde{\pi}(C(X))$ under the assumption that a certain family of
pure states of $\tilde{\pi}(C^* (\Sigma))$ is total. Furthermore we establish
that, if $C(X) \subsetneq C(X)'$, there exist both a $C^*$-subalgebra properly
between $C(X)$ and $C(X)'$ which has the aforementioned intersection property,
and such a $C^*$-subalgebra which does not have this property. We also discuss
existence of a projection of norm one from $C^*(\Sigma)$ onto the commutant of
$C(X)$.


title:
A New Family of Multistep Methods with Improved Phase Lag
  Characteristics for the Integration of Orbital Problems

abstract:
  In this work we introduce a new family of ten-step linear multistep methods
for the integration of orbital problems. The new methods are constructed by
adopting a new methodology which improves the phase lag characteristics by
vanishing both the phase lag function and its first derivatives at a specific
frequency. The efficiency of the new family of methods is proved via error
analysis and numerical applications.


title: Scaling in rupture of polymer chains

abstract:
  We consider the rupture dynamics of a homopolymer chain pulled at one end at
a constant loading rate r. Compared to single bond breaking, the existence of
the chain introduces two new aspects into rupture dynamics: the non-Markovian
aspect in the barrier crossing and the slow-down of the force propagation to
the breakable bond. The relative impact of both these processes is
investigated, and the second one was found to be the most important at moderate
loading rates. The most probable rupture force is found to decrease with the
number of bonds as f_{max} const-(ln(N/r))^(2/3) and finally to approach a
saturation value independent on N. All our analytical findings are confirmed by
extensive numerical simulations.


title:
Infrared study of the southern Galactic star forming regions associated
  with IRAS 10049-5657 and IRAS 10031-5632

abstract:
  The physical conditions of the interstellar medium and stellar components in
the regions of the southern Galactic star forming complexes associated with
IRAS 10049-5657 and IRAS 10031-5632 have been investigated. These regions have
been mapped simultaneously in two far infrared bands lambda_eff ~ 150 & 210
micron, with ~ 1' angular resolution using the TIFR 1-m balloon borne
telescope. Spatial distribution of the temperature of cool dust and optical
depth at 200 micron have been obtained. Using the 2MASS sources, the stellar
populations of the embedded young clusters have been studied. A rich cluster of
OB stars in the IRAS 10049-5657 region has been found with a cluster radius ~ 2
pc. The source in the cluster closest to the IRAS peak, lies above the ZAMS
curve of spectral type O5 in the colour-magnitude diagram. Unlike IRAS
10049-5657, a small cluster comprising of a few deeply embedded sources is seen
at the location of IRAS 10031-5632. Self consistent radiative transfer
modelling aimed at extracting important physical and geometrical details of the
two IRAS sources show that the best fit models are in good agreement with the
observed spectral energy distributions. The geometric details of the associated
cloud and optical depths (at 100 micron) have been estimated. A uniform density
distribution of dust and gas is implied for both the sources. In addition, the
infrared ionic fine-structure line emission from gas has been modelled for both
these regions and compared with data from IRAS-Low Resolution Spectrometer. For
IRAS 10049-5657, the observed and modelled luminosities for most lines agree to
within a factor of four while for IRAS 10031-5632, we find a discrepancy of a
factor of 100.


title:
Quenched lattice calculation of the vector channel B --> D* l nu decay
  rate

abstract:
  We calculate, in the continuum limit of quenched lattice QCD, the form factor
that enters the decay rate of the semileptonic decay B --> D* l nu. By using
the step scaling method (SSM), previously introduced to handle two scale
problems in lattice QCD, and by adopting flavor twisted boundary conditions we
extract F(w) at finite momentum transfer and at the physical values of the
heavy quark masses. Our results can be used in order to extract the CKM matrix
element Vcb by the experimental decay rate without model dependent
extrapolations. The value of Vcb agrees with the one obtained from the B --> D
l nu channel and makes us confident that the quenched approximation well
applies to these transitions.


title: Science Requirements for EAGLE for the E-ELT

abstract:
  We present an overview of the EAGLE science case, which spans
spatially-resolved spectroscopy of targets from five key science areas -
ranging from studies of heavily-obscured Galactic star clusters, right out to
the first galaxies at the highest redshifts. Here we summarise the requirements
adopted for study and also evaluate the availability of natural guide stars in
example fields, which will impact on the adaptive optics performance and
architecture.


title:
Dust Extinction and Emission in a Clumpy Galactic Disk. An Application
  of the Radiative Transfer Code TRADING

abstract:
  AIMS: I present the Monte Carlo radiative transfer code TRADING (Transfer of
RAdiation through Dust In Galaxies). The code computes self-consistently the
extinction of radiation in a dusty medium (including absorption and scattering)
and the dust emission. METHODS: A binary-tree adaptive grid is used for the
description of the dust distribution. Dust radiation is computed at thermal
equilibrium or under stochastic heating condition, for a distribution of grains
of different radii and materials. The code is applied to the case of a clumpy
galactic disk, including both diffuse dust and a distribution of spherical
clouds modelled on the GMCs of local galaxies. Diffuse and localised sources of
starlight are used, with independent spectra. RESULTS: A model is provided for
the edge-on galaxy NGC 891. The SED of the galaxy from the UV to the submm/mm
range can be well reproduced by: a bulge/disk configuration of old stars
together with an extended dust disk, as suggested by the analysis of
optical/near-infrared images; a clumpy dust distribution of the same mass as
the diffuse dust disk, together with a UV emitting component, half of which in
the form of a diffuse disk and half in sources embedded in clouds. In total, it
is found that about 35% of the bolometric radiation is absorbed (and emitted)
by dust; and that absorption of starlight from the old population contributes
to about 60% of the dust emission. A significant component of the dust emission
from clouds is due to absorption of diffuse radiation. Radial profiles of dust
emission in a clumpy disk are almost independent of the wavelength, with the
exception of the wavelength range on the Wien side of the thermal equilibrium
peak.


title: Strange mesons in nuclear matter at finite temperature

abstract:
  We study the properties of $K$ and $\bar K$ mesons in nuclear matter at
finite temperature from a chiral unitary approach in coupled channels which
incorporates the $s$- and p-waves of the kaon-nucleon interaction. The
in-medium solution accounts for Pauli blocking effects, mean-field binding on
all the baryons involved, and $\pi$ and kaon self-energies. We calculate $K$
and $\bar K$ (off-shell) spectral functions and single particle properties. The
$\bar K$ effective mass gets lowered by about -50 MeV in cold nuclear matter at
saturation density and by half this reduction at T=100 MeV. The p-wave
contribution to the ${\bar K}$ optical potential, due to $\Lambda$, $\Sigma$
and $\Sigma^*$ excitations, becomes significant for momenta larger than 200
MeV/c and reduces the attraction felt by the $\bar K$ in the nuclear medium.The
$\bar K$ spectral function spreads over a wide range of energies, reflecting
the melting of the $\Lambda (1405)$ resonance and the contribution of $YN^{-1}$
components at finite temperature. In the $KN$ sector, we find that the
low-density theorem is a good approximation for the $K$ self-energy close to
saturation density due to the absence of resonance-hole excitations. The $K$
potential shows a moderate repulsive behavior, whereas the quasi-particle peak
is considerably broadened with increasing density and temperature. We discuss
the implications for the decay of the $\phi$ meson at SIS/GSI energies as well
as in the future FAIR/GSI project.


title: Double beta decay: present status

abstract:
  The present status of double beta decay experiments (including the search for
$2\beta^{+}$, EC$\beta^{+}$ and ECEC processes) are reviewed. The results of
the most sensitive experiments are discussed. Average and recommended half-life
values for two-neutrino double beta decay are presented. Conservative upper
limits on effective Majorana neutrino mass and the coupling constant of the
Majoron to the neutrino are established as $<m_{\nu} > < 0.75$ eV and $<g_{ee}
> < 1.9 \cdot 10^{-4}$, respectively. Proposals for future double beta decay
experiments with a sensitivity for the $<m_{\nu}>$ at the level of (0.01-0.1)
eV are considered.


title: Three X-ray transients in M31 observed with Swift

abstract:
  The purpose of this study is to find transient X-ray sources in M31, and to
investigate and classify their nature. Three X-ray transients were observed
with Swift. For each of the three X-ray transients we use the Swift X-ray and
optical data together with observations from XMM-Newton and Chandra to
investigate the lightcurves and the spectra of the outburst, and thereby to
identify the source types. The outburst of XMMU J004215.8+411924 lasted for
about one month. The source had a hard power-law spectrum with a photon index
of 1.6. It was previously identified as a Be/X-ray binary based on the optical
identification with a star. However, we show that with improved source
coordinates it is clear that the optical source is not the counterpart to the
X-ray source. The source SWIFT J004217.3+411532 had a bright outburst, after
which it slowly decayed over half a year. The spectrum was soft, corresponding
to a thermal accretion disk with innermost temperature of 250-600 eV. The
source was not seen in the optical, and the soft spectrum indicates that the
source is most likely a black hole low mass X-ray binary. M31N 2006-11a is a
nova that was previously observed in the optical. We detected it both in X-rays
and UV with Swift half a year after the optical maximum, after which it decayed
below the Swift detection threshold within a month. The spectrum of the X-ray
transient can be modelled by a black-body with a temperature of 50 eV. We use
catalogues of X-ray transients in M31 to estimate their rate, and we find a
lower limit of 9/yr.


title: Casimir effect in a superconducting cavity and the thermal controversy

abstract:
  One of the most important and still unresolved problems in the field of
dispersion forces, is that of determining the influence of temperature on the
Casimir force between two metallic plates. While alternative theoretical
approaches lead to contradictory predictions for the magnitude of the effect,
no experiment has yet detected the thermal correction to the Casimir force. In
this paper we show that a superconducting cavity provides a new opportunity to
investigate the problem of the thermal dependence of the Casimir force in real
materials, by looking at the change of the Casimir force determined by a small
change of temperature. The actual feasibility of the proposed scheme is briefly
discussed.


title: The four site Higgsless model at the LHC

abstract:
  We consider the four-site Higgsless model, which predicts the existence of
four charged and two neutral extra gauge bosons, $W_{1,2}^\pm$ and $Z_{1,2}$.
In contrast to other Higgsless models, characterized by fermiophobic extra
gauge bosons, here sizeable fermion-boson couplings are allowed by the
electroweak precision data. We thus analyse the prospects of detecting the new
predicted particles in the mostly favored Drell-Yan channel at the LHC.


title:
Limit theorems for some adaptive MCMC algorithms with subgeometric
  kernels

abstract:
  This paper deals with the ergodicity and the existence of a strong law of
large numbers for adaptive Markov Chain Monte Carlo. We show that a diminishing
adaptation assumption together with a drift condition for positive recurrence
is enough to imply ergodicity. Strengthening the drift condition to a
polynomial drift condition yields a strong law of large numbers for possibly
unbounded functions. These results broaden considerably the class of adaptive
MCMC algorithms for which rigorous analysis is now possible. As an example, we
give a detailed analysis of the Adaptive Metropolis Algorithm of Haario et al.
(2001) when the target distribution is sub-exponential in the tails.


title:
An estimate from below for the Buffon needle probability of the
  four-corner Cantor set

abstract:
  Let $\Cant_n$ be the $n$-th generation in the construction of the middle-half
Cantor set. The Cartesian square $\K_n = \Cant_n \times \Cant_n$ consists of
$4^n$ squares of side-length $4^{-n}$. The chance that a long needle thrown at
random in the unit square will meet $\K_n$ is essentially the average length of
the projections of $\K_n$, also known as the Favard length of $\K_n$. A
classical theorem of Besicovitch implies that the Favard length of $\K_n$ tends
to zero. It is still an open problem to determine its exact rate of decay.
Until recently, the only explicit upper bound was $\exp(- c\log_* n)$, due to
Peres and Solomyak. ($\log_* n$ is the number of times one needs to take log to
obtain a number less than 1 starting from $n$). In Nazarov-Peres-Volberg paper
(arxiv:math 0801.2942) the power estimate from above was obtained. The exponent
in this paper was less than 1/6 but could have been slightly improved. On the
other hand, a simple estimate shows that from below we have the estimate
$\frac{c}{n}$. Here we apply the idea from papers of Nets Katz (MRL (1996),
527-536) and Bateman-Katz (arxiv:math/0609187v1 2006) to show that the estimate
from below can be in fact improved to $c \frac{\log n}{n}$. This is in drastic
difference from the case of {\em random} Cantor sets studied by Peres and
Solomyak in Pacific J. Math. 204 (2002), 473-496.


title:
Long-range correlations of density in a Bose-Einstein condensate
  expanding in a random potential

abstract:
  We study correlations of atomic density in a weakly interacting Bose-Einstein
condensate, expanding diffusively in a random potential. We show that these
correlations are long-range and that they are strongly enhanced at long times.
Density at distant points exhibits negative correlations.


title: Classical Theory of Fourier Series:Demystified and Generalised

abstract:
  For a Riemann integrable function on an interval and for a point therein,we
define 'Fourier series at the point on the interval' and bring out how and when
the function element becomes expressible as Fourier series.In this process,we
also generalise the theory by bringing in such concepts as finite Fourier
series,right/left hand Fourier series.We also sum up subseries corresponding to
terms in an arithmetic progression,of the basic Fourier series.


title: Gorenstein Modules of Finite Length

abstract:
  In Commutative Algebra structure results on minimal free resolutions of
Gorenstein modules are of classical interest. We define Gorenstein modules of
finite length over the weighted polynomial ring via symmetric matrices in
divided powers. We show that their graded minimal free resolution is selfdual
in a strong sense. Applications include a proof of the dependence of the monoid
of Betti tables of Cohen-Macaulay modules on the characteristic of the base
field. Moreover we give a new proof of the failure of the generalization of
Green's Conjecture to characteristic 2 in the case of general curves of genus
$2^n -1$.


title: Conductance spectra of metallic nanotube bundles

abstract:
  We report a first principles analysis of electronic transport characteristics
for (n,n) carbon nanotube bundles. When n is not a multiple of 3, inter-tube
coupling causes universal conductance suppression near Fermi level regardless
of the rotational arrangement of individual tubes. However, when n is a
multiple of 3, the bundles exhibit a diversified conductance dependence on the
orientation details of the constituent tubes. The total energy of the bundle is
also sensitive to the orientation arrangement only when n is a multiple of 3.
All the transport properties and band structures can be well understood from
the symmetry consideration of whether the rotational symmetry of the individual
tubes is commensurate with that of the bundle.


title:
Negative Compressibility of Single Selenium Chain Confined in Zeolite
  Pore

abstract:
  Pressure induced structural and electronic transitions of Se helical chains
confined inside nano-channels are studied. Raman scattering and optical
absorption experiments show strong evidence of band gap reduction under high
pressure. Ab initio calculations reveal that under hydrostatic compression, the
Se chains should elongate and the change in morphology leads to a softening of
phonons and narrowing of band gaps, and these signatures are observed in
experiments. Our investigation demonstrates a negative compressibility in one
dimension.


title: Disk Sizes in a LCDM Universe

abstract:
  We introduce a model which uses semi-analytic techniques to trace formation
and evolution of galaxy disks in their cosmological context. For the first time
we model the growth of gas and stellar disks separately. In contrast to
previous work we follow in detail the angular momentum accumulation history
through the gas cooling, merging and star formation processes. Our model
successfully reproduces the stellar mass--radius distribution and
gas-to-stellar disk size ratio distribution observed locally. We also
investigate the dependence of clustering on galaxy size and find qualitative
agreement with observation. There is still some discrepancy at small scale for
less massive galaxies, indicating that our treatment of satellite galaxies
needs to be improved.


title:
The stochastic approximation method for the estimation of a multivariate
  probability density

abstract:
  We apply the stochastic approximation method to construct a large class of
recursive kernel estimators of a probability density, including the one
introduced by Hall and Patil (1994). We study the properties of these
estimators and compare them with Rosenblatt's nonrecursive estimator. It turns
out that, for pointwise estimation, it is preferable to use the nonrecursive
Rosenblatt's kernel estimator rather than any recursive estimator. A contrario,
for estimation by confidence intervals, it is better to use a recursive
estimator rather than Rosenblatt's estimator.


title:
Perturbed affine arithmetic for invariant computation in numerical
  program analysis

abstract:
  We completely describe a new domain for abstract interpretation of numerical
programs. Fixpoint iteration in this domain is proved to converge to finite
precise invariants for (at least) the class of stable linear recursive filters
of any order. Good evidence shows it behaves well also for some non-linear
schemes. The result, and the structure of the domain, rely on an interesting
interplay between order and topology.


title: Superhedging in illiquid markets

abstract:
  We study contingent claims in a discrete-time market model where trading
costs are given by convex functions and portfolios are constrained by convex
sets. In addition to classical frictionless markets and markets with
transaction costs or bid-ask spreads, our framework covers markets with
nonlinear illiquidity effects for large instantaneous trades. We derive dual
characterizations of superhedging conditions for contingent claim processes in
a market without a cash account. The characterizations are given in terms of
stochastic discount factors that correspond to martingale densities in a market
with a cash account. The dual representations are valid under a topological
condition and a weak consistency condition reminiscent of the ``law of one
price'', both of which are implied by the no arbitrage condition in the case of
classical perfectly liquid market models. We give alternative sufficient
conditions that apply to market models with nonlinear cost functions and
portfolio constraints.


title: Remarks on cycle classes of sections of the arithmetic fundamental group

abstract:
  Given a smooth and separated K(pi,1) variety X over a field k, we associate a
"cycle class" in etale cohomology with compact supports to any continuous
section of the natural map from the arithmetic fundamental group of X to the
absolute Galois group of k. We discuss the algebraicity of this class in the
case of curves over p-adic fields, and deduce in particular a new proof of
Stix's theorem according to which the index of a curve X over a p-adic field k
must be a power of p as soon as the natural map from the arithmetic fundamental
group of X to the absolute Galois group of k admits a section. Finally, an
etale adaptation of Beilinson's geometrization of the pronilpotent completion
of the topological fundamental group allows us to lift this cycle class in
suitable cohomology groups.