title: Vadim Kuznetsov. Informal Biography by Eyes of His First Adviser

abstract:
  The paper is dedicated to the memory of prominent theoretical physicist and
mathematician Dr. Vadim Kuznetsov who worked, in particular, in the fields of
the nonlinear dynamics, separation of variables, integrability theory, special
functions. It includes his short research biography, an account of the start of
his research career and the list of publications.


title: A Confining Strong First-Order Electroweak Phase Transition

abstract:
  In the Randall-Sundrum model where the radion is stabilized by a
Goldberger-Wise (GW) potential there is a supercooled transition from a
deconfined to a confined phase at temperatures orders of magnitude below the
typical Standard Model critical temperature. When the Higgs is localized at the
IR brane the electroweak phase transition is delayed and becomes a strong
first-order one where the Universe expands by a few e-folds. This generates the
possibility of having the out-of-equilibrium condition required by electroweak
baryogenesis in the electroweak phase transition. We have studied numerically
the region of the GW parameter space where the theory is consistent and the
latter possibility is realized. We have found that in most of the parameter
space the nucleation temperature is so low that sphalerons are totally inactive
inside the bubbles. The condition for sphalerons to be inactive after reheating
imposes an upper bound on the reheating temperature that is weaker for heavy
Higgs bosons so that the out-of-equilibrium condition seems to favor heavy over
light Higgses. The condition for sphalerons to be active outside the bubbles
puts an upper bound on the number of e-folds at the phase transition, roughly
consistent with the critical value required by low-scale inflation to solve the
cosmological horizon problem.


title:
Characterization of the Radon-Nikodym Property in terms of inverse
  limits

abstract:
  We clarify the relation between inverse systems, the Radon-Nikodym property,
the Asymptotic Norming Property of James-Ho, and the GFDA spaces introduced in
our earlier paper on differentiability of Lipschitz maps into Banach spaces.


title: Influence of friction on granular segregation

abstract:
  Vertical shaking of a mixture of small and large beads can lead to
segregation where the large beads either accumulate at the top of the sample,
the so called Brazil Nut effect (BNE), or at the bottom, the Reverse Brazil Nut
effect (RBNE). Here we demonstrate experimentally a sharp transition from the
RBNE to the BNE when the particle coefficient of friction increases due to
aging of the particles. This result can be explained by the two competing
mechanisms of buoyancy and sidewall-driven convection, where the latter is
assumed to grow in strength with increasing friction.


title:
The Overdensity in Virgo, Sagittarius Debris, and the Asymmetric
  Spheroid

abstract:
  We investigate the relationship between several previously identified
Galactic halo stellar structures in the direction of Virgo using imaging and
spectroscopic observations of F turnoff stars and blue horizontal branch stars
from the Sloan Digital Sky Survey (SDSS) and the Sloan Extension for Galactic
Understanding and Exploration (SEGUE). We show that the Sagittarius dwarf
leading tidal tail does not pass through the solar neighborhood; it misses the
Sun by more than 15 kpc, passing through the Galactic plane outside the Solar
Circle. It also is not spatially coincident with the large stellar overdensity
S297+63-20.5 in the Virgo constellation. S297+63-20.5 has a distinct turnoff
color and kinematics. Faint (g ~ 20.3) turnoff stars in S297+63-20.5 have
line-of-sight, Galactic standard of rest velocities V(GSR)= 130 +/- 10 km/s,
opposite in sign to infalling Sgr tail stars. The path of the Sgr leading tidal
tail is also inconsistent with the positions of some of the nearer stars with
which it has been associated, and whose velocities have favored models with
prolate Milky Way potentials. We additionally show that the number densities of
brighter (g ~ 19.8) F turnoff stars are not symmetric about the Galactic
center, and that this discrepancy is not primarily due to the S297+63-20.5
moving group. Either the spheroid is asymmetric about the Galactic center, or
there are additional substructures that conspire to be on the same side of the
Galaxy as S297+63-20.5. The S297+63-20.5 overdensity in Virgo is likely
associated with two other previously identified Virgo substructures: the Virgo
Stellar Stream (VSS) and the Virgo Overdensity (VOD). However, the velocity
difference between the VSS and S297+63-20.5 and the difference in distance
estimates between the VOD and S297+63-20.5 must be reconciled.


title: Solving SPDEs driven by colored noise: a chaos approach

abstract:
  An Ito-Skorokhod bi-linear equation driven by infinitely many independent
colored noises is considered in a normal triple of Hilbert spaces. The special
feature of the equation is the appearance of the Wick product in the definition
of the Ito-Skorokhod integral, requiring innovative approaches to computing the
solution. A chaos expansion of the solution is derived and several truncations
of this expansion are studied. A recursive approximation of the solution is
suggested and the corresponding approximation error bound is computed.


title: Towards a covariant model for cosmic self-acceleration

abstract:
  An explicitly covariant formulation is presented of a modified DGP scenario
proposed recently [1], to avoid the instability of the self-accelerating
branch. It is based on the introduction of a bulk scalar field with appropriate
non-minimal coupling to the bulk Einstein-Hilbert term. The method is general
and may be applied to other models as well.


title: Black Ring Deconstruction

abstract:
  We present a sample microstate for a black ring in four and five dimensional
language. The microstate consists of a black string microstate with an
additional D6-brane. We show that with an appropriate choice of parameters the
piece involving the black string microstate falls down a long AdS throat, whose
M-theory lift is AdS_3 X S^2. We wrap a spinning dipole M2-brane on the S^2 in
the probe approximation. In IIA, this corresponds to a dielectric D2-brane
carrying only D0-charge. We conjecture this is the first approximation to a
cloud of D0-branes blowing up due to their non-abelian degrees of freedom and
the Myers effect.


title: Ion Charge States in Halo CMEs: What can we Learn about the Explosion?

abstract:
  We describe a new modeling approach to develop a more quantitative
understanding of the charge state distributions of the ions of various elements
detected in situ during halo Coronal Mass Ejection (CME) events by the Advanced
Composition Explorer (ACE) satellite. Using a model CME hydrodynamic evolution
based on observations of CMEs propagating in the plane of the sky and on
theoretical models, we integrate time dependent equations for the ionization
balance of various elements to compare with ACE data. We find that plasma in
the CME ``core'' typically requires further heating following filament
eruption, with thermal energy input similar to the kinetic energy input. This
extra heating is presumably the result of post eruptive reconnection. Plasma
corresponding to the CME ``cavity'' is usually not further ionized, since
whether heated or not, the low density gives freeze-in close the the Sun. The
current analysis is limited by ambiguities in the underlying model CME
evolution. Such methods are likely to reach their full potential when applied
to data to be acquired by STEREO when at optimum separation. CME evolution
observed with one spacecraft may be used to interpret CME charge states
detected by the other.


title: Strings ending on branes from supergravity

abstract:
  We study geometries produced by brane intersections preserving eight
supercharges. Typical examples of such configurations are given by fundamental
strings ending on Dp branes and we construct gravity solutions describing such
intersections. The geometry is specified in terms of two functions obeying
coupled differential equations and the boundary conditions are determined by
distributions of D branes. We show that a consistency of type IIB supergravity
constrains the allowed positions of the branes. The shapes of branes derived
from gravity are found to be in a perfect agreement with profiles predicted by
the DBI analysis. We also discuss related 1/4-BPS systems in M theory.


title:
Fock representation of the renormalized higher powers of white noise and
  the Virasoro--Zamolodchikov--$w_{\infty} *$--Lie algebra

abstract:
  The identification of the $*$--Lie algebra of the renormalized higher powers
of white noise (RHPWN) and the analytic continuation of the second quantized
Virasoro--Zamolodchikov--$w_{\infty} *$--Lie algebra of conformal field theory
and high-energy physics, was recently established in \cite{id} based on results
obtained in [1] and [2]. In the present paper we show how the RHPWN Fock
kernels must be truncated in order to be positive definite and we obtain a Fock
representation of the two algebras. We show that the truncated renormalized
higher powers of white noise (TRHPWN) Fock spaces of order $\geq 2$ host the
continuous binomial and beta processes.


title: The slice-ribbon conjecture for 3-stranded pretzel knots

abstract:
  We determine the smooth concordance order of the 3-stranded pretzel knots
P(p,q,r) with p,q,r odd. We show that each one of finite order is, in fact,
ribbon, thereby proving the slice-ribbon conjecture for this family of knots.
As corollaries we give new proofs of results first obtained by Fintushel-Stern
and Casson-Gordon.


title:
Penguin Loops for Nonleptonic B-Decays in the Standard Model: Is there a
  Penguin Puzzle?

abstract:
  We compute standard model penguin amplitudes in nonleptonic B-decays to light
charmless mesons using tree amplitude data to fix hadronic parameters. The
leading calculation is carried out for the alphas(mb) penguin contributions
from charm quark, up quark, and magnetic penguin loops in the NDR and HV
renormalization schemes. Power suppressed penguins that are proportional to the
chiral condensate are also computed using a new factorization formula for these
terms, which is derived working to all orders in alphas(sqrt{mb\Lambda}). We
demonstrate using SCET1 that this formula exhibits only small perturbative
phases and does not have endpoint singularities. Due to our use of data to fix
hadronic parameters we obtain significantly more accurate predictions for the
short-distance standard model penguin amplitudes than have been found in the
past. Analyzing data in B-> pi pi, B->K pi, and B->rho rho for the penguin
amplitudes we find that standard model short-distance imaginary parts are an
order of magnitude smaller than current measurements, while real parts are up
to a factor of two smaller with the correct sign. This difference is most
likely a consequence of long-distance charm contributions or new physics.
Constraints on the type of new physics that could help explain the data are
derived, and used to show that current data favors sizeable long-distance
strong phases.


title: Channel-Adapted Quantum Error Correction

abstract:
  Quantum error correction (QEC) is an essential concept for any quantum
information processing device. Typically, QEC is designed with minimal
assumptions about the noise process; this generic assumption exacts a high cost
in efficiency and performance. In physical systems, errors are not likely to be
arbitrary; rather we will have reasonable models for the structure of quantum
decoherence. We may choose quantum error correcting codes and recovery
operations that specifically target the most likely errors.
  We present a convex optimization method to determine the optimal (in terms of
average entanglement fidelity) recovery operation for a given channel,
encoding, and information source. This is solvable via a semidefinite program
(SDP). We present computational algorithms to generate near-optimal recovery
operations structured to begin with a projective syndrome measurement. These
structured operations are more computationally scalable than the SDP required
for computing the optimal; we can thus numerically analyze longer codes. Using
Lagrange duality, we bound the performance of the structured recovery
operations and show that they are nearly optimal in many relevant cases.
  We present two classes of channel-adapted quantum error correcting codes
specifically designed for the amplitude damping channel. These have
significantly higher rates with shorter block lengths than corresponding
generic quantum error correcting codes. Both classes are stabilizer codes, and
have good fidelity performance with stabilizer recovery operations. The
encoding, syndrome measurement, and syndrome recovery operations can all be
implemented with Clifford group operations.


title: Measurement-based quantum computation beyond the one-way model

abstract:
  We introduce novel schemes for quantum computing based on local measurements
on entangled resource states. This work elaborates on the framework established
in [Phys. Rev. Lett. 98, 220503 (2007), quant-ph/0609149]. Our method makes use
of tools from many-body physics - matrix product states, finitely correlated
states or projected entangled pairs states - to show how measurements on
entangled states can be viewed as processing quantum information. This work
hence constitutes an instance where a quantum information problem - how to
realize quantum computation - was approached using tools from many-body theory
and not vice versa. We give a more detailed description of the setting, and
present a large number of new examples. We find novel computational schemes,
which differ from the original one-way computer for example in the way the
randomness of measurement outcomes is handled. Also, schemes are presented
where the logical qubits are no longer strictly localized on the resource
state. Notably, we find a great flexibility in the properties of the universal
resource states: They may for example exhibit non-vanishing long-range
correlation functions or be locally arbitrarily close to a pure state. We
discuss variants of Kitaev's toric code states as universal resources, and
contrast this with situations where they can be efficiently classically
simulated. This framework opens up a way of thinking of tailoring resource
states to specific physical systems, such as cold atoms in optical lattices or
linear optical systems.


title:
Diffusion kinetic parameters from bulk diffusion limited gas release
  processes

abstract:
  The diffusion of a bulk absorbed gas species out of spherical pebbles is
studied analytically, stressing the usefulness of the time integral of the
diffusion coefficient for analysis of arbitrary temperature schedule
experiments. Highly accurate approximations are introduced where the numeric
evaluation of the analytic expressions takes considerable time. A method is
proposed to extract the diffusion kinetic parameters from a single linear
heating ramp, namely, the activation energy of the diffusion coefficient and
the ratio of the corresponding preexponential factor to the radius of spherical
pebbles.


title: Border trees of complex networks

abstract:
  The comprehensive characterization of the structure of complex networks is
essential to understand the dynamical processes which guide their evolution.
The discovery of the scale-free distribution and the small world property of
real networks were fundamental to stimulate more realistic models and to
understand some dynamical processes such as network growth. However, properties
related to the network borders (nodes with degree equal to one), one of its
most fragile parts, remain little investigated and understood. The border nodes
may be involved in the evolution of structures such as geographical networks.
Here we analyze complex networks by looking for border trees, which are defined
as the subgraphs without cycles connected to the remainder of the network
(containing cycles) and terminating into border nodes. In addition to
describing an algorithm for identification of such tree subgraphs, we also
consider a series of their measurements, including their number of vertices,
number of leaves, and depth. We investigate the properties of border trees for
several theoretical models as well as real-world networks.


title:
Disk-Planet Interaction Simulations: (I) Baroclinic Generation of
  Vortensity and Non-Axisymmetric Rossby-Wave-Instability

abstract:
  We use a multi-dimensional hydrodynamics code to study the gravitational
interaction between an embedded planet and a protoplanetary disk with emphasis
on the generation of vortensity (potential vorticity) through a Baroclinic
Instability and subsequent development of Rossby-Wave-Instability (RWI). It is
found that the generation of potential vorticity is very common and effective
in non-barotropic disks through the Baroclinic Instability, especially within
the coorbital region. Our results also complement previous studies by
\citet{KLL03} that non-axisymmetric RWIs are likely to develop at local minima
of potential vorticity distribution that are generated by the interaction
between a planet and a inviscid barotropic disk. This second instability
appears to be very common and robust, regardless of the equation of state,
initial density distribution, and rotational law of the disk. The development
of RWIs results in non-axisymmetric density blobs, which exert stronger torques
onto the planet when they travel in the vicinity of the planet. As a result of
that, large amplitude oscillations are introduced to the time behavior of the
total torque acted on the planet by the disk. In our current simulations, RWIs
do not change the overall picture of inward orbital migration but bring in a
non-monotonic behavior to the migration speed. As a side effect, RWIs also
introduce interesting structures into the disk. These structures may help the
formation of Earth-like planets in the Habitable Zone or Hot Earths interior to
a close-in giant planet.


title: On Point Coverings of Boxes in $\mathbb R^d$

abstract:
  Families of boxes in $\mathbb R^d$ are considered. In the paper an upper
bound on the size of a minimum transversal in terms of the space dimension and
the independence number of the given family was improved.


title: A Universal Interacting Crossover Regime in Two-Dimensional Quantum Dots

abstract:
  Interacting electrons in quantum dots with large Thouless number $g$ in the
three classical random matrix symmetry classes are well-understood. When a
specific type of spin-orbit coupling known to be dominant in two dimensional
semiconductor quantum dots is introduced, we show that a new interacting
quantum critical crossover energy scale emerges and low-energy quasiparticles
generically have a decay width proportional to their energy. The low-energy
physics of this system is an example of a universal interacting crossover
regime.


title: Abundances of Planetary Nebula M1-42

abstract:
  The spectra of the planetary nebula M1-42 is reanalysed using spectral
measurements made in the mid-infrared with the Spitzer Space Telescope. The aim
is to determine the chemical composition of this object. We also make use of
ISO, IUE and ground based spectra. Abundances determined from the mid- and
far-infrared lines, which are insensitive to electron temperature, are used as
the basis for the determination of the composition, which are found to
substantially differ from earlier results. High values of neon, argon and
sulfur are found. They are higher than in other PN, with the exception of
NGC6153, a nebula of very similar abundances. The high values of helium and
nitrogen found indicate that the second dredge-up and hot bottom burning has
occurred in the course of evolution and that the central star was originally
more massive than 4Msun. The present temperature and luminosity of the central
star is determined and at first sight may be inconsistent with such a high
mass.


title: Current Renormalization in Finite Volume

abstract:
  For finite volume field theories with discrete translational invariance,
conserved currents can be additively renormalized by infrared effects. We
demonstrate this for pions using chiral perturbation theory coupled to
electromagnetism in a periodic box. Gauge invariant single particle effective
theories are constructed to explain these results. In such theories, current
renormalization arises from operators involving the zero mode of the gauge
field. No contradictions with Ward identities, or low-energy theorems are
encountered.


title: Spinless photon dark matter from two universal extra dimensions

abstract:
  We explore the properties of dark matter in theories with two universal extra
dimensions, where the lightest Kaluza-Klein state is a spin-0 neutral particle,
representing a six-dimensional photon polarized along the extra dimensions.
Annihilation of this 'spinless photon' proceeds predominantly through Higgs
boson exchange, and is largely independent of other Kaluza-Klein particles. The
measured relic abundance sets an upper limit on the spinless photon mass of 500
GeV, which decreases to almost 200 GeV if the Higgs boson is light. The
phenomenology of this dark matter candidate is strikingly different from
Kaluza-Klein dark matter in theories with one universal extra dimension.
Elastic scattering of the spinless photon with quarks is helicity suppressed,
making its direct detection challenging, although possible at upcoming
experiments. The prospects for indirect detection with gamma rays and
antimatter are similar to those of neutralinos. The rates predicted at neutrino
telescopes are below the sensitivity of next-generation experiments.


title: Noncommuting Flux Sectors in a Tabletop Experiment

abstract:
  We show how one can use superconductors and Josephson junctions to create a
laboratory system which can explore the groundstates of the free
electromagnetic field in a 3-manifold with torsion in its cohomology.


title: Cavity QED with a Bose-Einstein condensate

abstract:
  Cavity quantum electrodynamics (cavity QED) describes the coherent
interaction between matter and an electromagnetic field confined within a
resonator structure, and is providing a useful platform for developing concepts
in quantum information processing. By using high-quality resonators, a strong
coupling regime can be reached experimentally in which atoms coherently
exchange a photon with a single light-field mode many times before dissipation
sets in. This has led to fundamental studies with both microwave and optical
resonators. To meet the challenges posed by quantum state engineering and
quantum information processing, recent experiments have focused on laser
cooling and trapping of atoms inside an optical cavity. However, the tremendous
degree of control over atomic gases achieved with Bose-Einstein condensation
has so far not been used for cavity QED. Here we achieve the strong coupling of
a Bose-Einstein condensate to the quantized field of an ultrahigh-finesse
optical cavity and present a measurement of its eigenenergy spectrum. This is a
conceptually new regime of cavity QED, in which all atoms occupy a single mode
of a matter-wave field and couple identically to the light field, sharing a
single excitation. This opens possibilities ranging from quantum communication
to a wealth of new phenomena that can be expected in the many-body physics of
quantum gases with cavity-mediated interactions.


title: On Canonical Forms of Complete Problems via First-order Projections

abstract:
  The class of problems complete for NP via first-order reductions is known to
be characterized by existential second-order sentences of a fixed form. All
such sentences are built around the so-called generalized IS-form of the
sentence that defines Independent-Set. This result can also be understood as
that every sentence that defines a NP-complete problem P can be decomposed in
two disjuncts such that the first one characterizes a fragment of P as hard as
Independent-Set and the second the rest of P. That is, a decomposition that
divides every such sentence into a quotient and residue modulo Independent-Set.
  In this paper, we show that this result can be generalized over a wide
collection of complexity classes, including the so-called nice classes.
Moreover, we show that such decomposition can be done for any complete problem
with respect to the given class, and that two such decompositions are
non-equivalent in general. Interestingly, our results are based on simple and
well-known properties of first-order reductions.ow that this result can be
generalized over a wide collection of complexity classes, including the
so-called nice classes. Moreover, we show that such decomposition can be done
for any complete problem with respect to the given class, and that two such
decompositions are non-equivalent in general. Interestingly, our results are
based on simple and well-known properties of first-order reductions.


title:
Orbital ordering in the ferromagnetic insulator Cs$_2$AgF$_4$ from first
  principles

abstract:
  We found, using density-functional theory calculations within the generalized
gradient approximation, that Cs$_2$AgF$_4$ is stabilized in the insulating
orthorhombic phase rather than in the metallic tetragonal phase. The lattice
distortion present in the orthorhombic phase corresponds to the
$x^2-z^2$/$y^2-z^2$ hole-orbital ordering of the Ag$^{2+}$ $4d^9$ ions, and
this orbital ordering leads to the observed ferromagnetism, as confirmed by the
present total-energy calculations. This picture holds in the presence of
moderate 4d-electron correlation. The results are compared with the picture of
ferromagnetism based on the metallic tetragonal phase.


title:
Direct measurement of the intermolecular forces confining a single
  molecule in an entangled polymer solution

abstract:
  We use optical tweezers to directly measure the intermolecular forces acting
on a single polymer imposed by surrounding entangled polymers (115 kbp DNA, 1
mg/ml). A tube-like confining field was measured in accord with the key
assumption of reptation models. A time-dependent harmonic potential opposed
transverse displacement, in accord with recent simulation findings. A tube
radius of 0.8 microns was determined, close to the predicted value (0.5
microns). Three relaxation modes (~0.4, 5 and 30 s) were measured following
transverse displacement, consistent with predicted relaxation mechanisms.


title:
Spectral stability of noncharacteristic isentropic Navier-Stokes
  boundary layers

abstract:
  Building on work of Barker, Humpherys, Lafitte, Rudd, and Zumbrun in the
shock wave case, we study stability of compressive, or "shock-like", boundary
layers of the isentropic compressible Navier-Stokes equations with gamma-law
pressure by a combination of asymptotic ODE estimates and numerical Evans
function computations. Our results indicate stability for gamma in the interval
[1, 3] for all compressive boundary-layers, independent of amplitude, save for
inflow layers in the characteristic limit (not treated). Expansive inflow
boundary-layers have been shown to be stable for all amplitudes by Matsumura
and Nishihara using energy estimates. Besides the parameter of amplitude
appearing in the shock case, the boundary-layer case features an additional
parameter measuring displacement of the background profile, which greatly
complicates the resulting case structure. Moreover, inflow boundary layers turn
out to have quite delicate stability in both large-displacement and
large-amplitude limits, necessitating the additional use of a mod-two stability
index studied earlier by Serre and Zumbrun in order to decide stability.


title:
Classical capacity of bosonic broadcast communication and a new minimum
  output entropy conjecture

abstract:
  Previous work on the classical information capacities of bosonic channels has
established the capacity of the single-user pure-loss channel, bounded the
capacity of the single-user thermal-noise channel, and bounded the capacity
region of the multiple-access channel. The latter is a multi-user scenario in
which several transmitters seek to simultaneously and independently communicate
to a single receiver. We study the capacity region of the bosonic broadcast
channel, in which a single transmitter seeks to simultaneously and
independently communicate to two different receivers. It is known that the
tightest available lower bound on the capacity of the single-user thermal-noise
channel is that channel's capacity if, as conjectured, the minimum von Neumann
entropy at the output of a bosonic channel with additive thermal noise occurs
for coherent-state inputs. Evidence in support of this minimum output entropy
conjecture has been accumulated, but a rigorous proof has not been obtained. In
this paper, we propose a new minimum output entropy conjecture that, if proved
to be correct, will establish that the capacity region of the bosonic broadcast
channel equals the inner bound achieved using a coherent-state encoding and
optimum detection. We provide some evidence that supports this new conjecture,
but again a full proof is not available.


title:
Superfuid-insulator transitions at non-integer filling in optical
  lattices of fermionic atoms

abstract:
  We determine the superfluid transition temperatures $T_c$ and the ground
states of the attractive Hubbard model and find new insulating phases
associated with non-integer filling at sufficiently strong pairing attraction
$|U|$. These states, distinct from band and Mott insulating phases, derive from
pair localization; pair hopping at large $|U|$ and high densities is impeded by
inter-site, inter-pair repulsive interactions. The best way to detect the
breakdown of superfluidity is using fermionic optical lattices which should
reveal new forms of ``bosonic'' order, reflecting ground state pairing without
condensation.

categories: cond-mat.other cond-mat.quant-gas cond-mat.str-el cond-mat.supr-con


title:
Tunneling Density of States, Pair Correlation, and Josephson Current in
  Spin-Incoherent Luttinger Liquid-Superconductor Hybrid Systems

abstract:
  We study a hybrid system consisting of a spin-incoherent Luttinger liquid
adjoined at one or both ends to a superconductor. We find the tunneling density
of states diverges at low energies and exhibits a universal frequency
dependence independent of the strength of the interactions in the system. We
show that in spite of exponentially decaying pair correlations with distance
into the spin-incoherent Luttinger liquid, the Josephson current remains
robust. Compared to the zero temperature Luttinger liquid case there is a
factor of 2 reduction in the critical current and a halving of the period in
the phase difference between the superconductors. Our results open the way for
a new class of experiments in the spin-incoherent regime of one dimensional
systems.


title:
New PVLAS results and limits on magnetically induced optical rotation
  and ellipticity in vacuum

abstract:
  IIn 2006 the PVLAS collaboration reported the observation of an optical
rotation generated in vacuum by a magnetic field. To further check against
possible instrumental artifacts several upgrades to the PVLAS apparatus have
been made during the last year. Two data taking runs, at the wavelength of 1064
nm, have been performed in the new configuration with magnetic field strengths
of 2.3 T and 5 T. The 2.3 T field value was chosen in order to avoid stray
fields. The new observations do not show the presence of a rotation signal down
to the levels of $1.2\cdot 10^{-8}$ rad at 5 T and $1.0\cdot 10^{-8}$ rad at
2.3 T (at 95% c.l.) with 45000 passes in the magnetic field zone. In the same
conditions no ellipticity signal was detected down to $1.4\cdot 10^{-8}$ at 2.3
T (at 95% c.l.), whereas at 5 T a signal is still present. The physical nature
of this ellipticity as due to an effect depending on $B^2$ can be excluded by
the measurement at 2.3 T. These new results completely exclude the previously
published magnetically induced vacuum dichroism results, indicating that they
were instrumental artifacts. These new results therefore also exclude the
particle interpretation of the previous PVLAS results as due to a spin zero
boson. The background ellipticity at 2.3 T can be used to determine a new limit
on the total photon-photon scattering cross section of $\sigma_{\gamma\gamma} <
4.5 \cdot10^{-34}$ barn at 95% c.l..


title: Non-universal dynamics of dimer growing interfaces

abstract:
  A finite temperature version of body-centered solid-on-solid growth models
involving attachment and detachment of dimers is discussed in 1+1 dimensions.
The dynamic exponent of the growing interface is studied numerically via the
spectrum gap of the underlying evolution operator. The finite size scaling of
the latter is found to be affected by a standard surface tension term on which
the growth rates depend. This non-universal aspect is also corroborated by the
growth behavior observed in large scale simulations. By contrast, the
roughening exponent remains robust over wide temperature ranges.


title: The cold neutron star in the soft X-ray transient 1H 1905+000

abstract:
  We report on our analysis of 300 ks of Chandra observations of the neutron
star soft X-ray transient 1H1905+000 in quiescence. We do not detect the source
down to a 95% confidence unabsorbed flux upper limit of 2E-16 erg cm-2 s-1 in
the 0.5-10 keV energy range for an assumed Gamma=2 power law spectral model. A
limit of 1.4E-16 erg cm-2 s-1 is derived if we assume that the spectrum of
1H1905+000 in quiescence is described well with a black body of temperature of
0.2 keV. For the upper limit to the source distance of 10 kpc this yields a
0.5-10 keV luminosity limit of 2.4E30 / 1.7E30 erg/s for the abovementioned
power law or black body spectrum, respectively. This luminosity limit is lower
than the luminosity of A0620-00, the weakest black hole soft X-ray transient in
quiescence reported so far. Together with the uncertainties in relating the
mass transfer and mass accretion rates we come to the conclusion that the claim
that there is evidence for the presence of a black hole event horizon on the
basis of a lower quiescent luminosity for black holes than for neutron stars is
unproven. We also briefly discuss the implications of the low quiescent
luminosity of 1H1905+000 for the neutron star equation of state. Using deep
Magellan images of the field of 1H1905+000 obtained at excellent observing
conditions we do not detect the quiescent counterpart at the position of the
outburst optical counterpart down to a magnitude limit of i'>25.3. This can be
converted to a limit on the absolute magnitude of the counterpart of I>9.6
which implies that the counterpart can only be a brown or a white dwarf.


title:
Dual representation of Polyakov loop in 3d SU(2) lattice Yang-Mills
  theory

abstract:
  We consider the expectation value of a Polyakov loop in 3d SU(2) lattice
Yang--Mills theory and transform it to the dual representation in terms of sums
over spins. The spin dependence of the amplitudes is computed explicitly by a
graphical method. We also determine the asymptotic (large spin) limit of the
amplitude factors.


title: An exact string representation of 3d SU(2) lattice Yang--Mills theory

abstract:
  We show that 3d SU(2) lattice Yang--Mills theory can be cast in the form of
an exact string representation. The derivation starts from the exact dual (or
spin foam) representation of the lattice gauge theory. We prove that every dual
configuration (or spin foam) can be equivalently described as a self--avoiding
worldsheet of strings on a framing of the lattice. Using this correspondence,
we translate the partition function into a sum over closed worldsheets that are
weighted with explicit amplitudes. The expectation value of two Polyakov loops
with spin j becomes a sum over worldsheets that are bounded by 2j strings along
a framing of the loops.


title:
Keck/Deimos Spectroscopy of a GALEX UV Selecte Sample from the Medium
  Imaging Survey

abstract:
  We report results from a pilot program to obtain spectroscopy for objects
detected in the Galaxy Evolution Explorer (GALEX) Medium Imaging Survey (MIS).
Our study examines the properties of galaxies detected by GALEX fainter than
the Sloan Digital Sky Survey (SDSS) spectroscopic survey. This is the first
study to extend the techinques of Salim et al. 2005 to estimate stellar masses,
star formation rates (SFR) and the b (star formation history) parameter for
star-forming galaxies out to z~0.7. We obtain redshifts for 50 GALEX MIS
sources reaching NUV=23.9 (AB mag), having counterparts in the SDSS Data
Release 4 (DR4). Of our sample, 43 are starforming galaxies with z<0.7, 3 have
emission line ratios indicative of AGN with z<0.7, and 4 objects with z~1 are
QSOs, 3 of which are not previously cataloged. We compare our sample to a much
larger sample of ~50,000 matched GALEX/SDSS galaxies with SDSS spectroscopy;
while our survey is shallow, the optical counterparts to our sources reach ~3
magnitudes fainter in SDSS r magnitude than the SDSS spectroscopic sample. We
use emission line diagnostics for the galaxies to determine that the sample
contains mostly star-forming galaxies. The galaxies in the sample populate the
blue sequence in the NUV-r vs M_r color-magnitude diagram. Our sample has SFRs,
luminosities, and velocity dispersions that are similar to the samples of faint
compact blue galaxies studied previously in the same redshift range by Koo et.
al 1995, Guzman et. al 1996 & Phillips et. al 1997. However, our sample is ~2
mag fainter in surface brightness than the compact blue galaxies. We find that
the star-formation histories for a majority of the galaxies are consistent with
a recent starburst within the last 100 Myr.


title: Twisted conjugacy classes in nilpotent groups

abstract:
  A group is said to have the $R_\infty$ property if every automorphism has an
infinite number of twisted conjugacy classes. We study the question whether $G$
has the $R_\infty$ property when $G$ is a finitely generated torsion-free
nilpotent group. As a consequence, we show that for every positive integer
$n\ge 5$, there is a compact nilmanifold of dimension $n$ on which every
homeomorphism is isotopic to a fixed point free homeomorphism. As a by-product,
we give a purely group theoretic proof that the free group on two generators
has the $R_\infty$ property. The $R_{\infty}$ property for virtually abelian
and for $\mathcal C$-nilpotent groups are also discussed.


title:
Distribution of $^{56}$Ni Yields of Type Ia Supernovae and its
  Implication for Progenitors

abstract:
  The amount of $^{56}$Ni produced in type Ia supernova (SN Ia) explosion is
probably the most important physical parameter underlying the observed
correlation of SN Ia luminosities with their light curves. Based on an
empirical relation between the $^{56}$Ni mass and the light curve parameter
$\triangle m_{15}$, we obtained rough estimates of the $^{56}$Ni mass for a
large sample of nearby SNe Ia with the aim of exploring the diversity in SN Ia.
We found that the derived $^{56}$Ni masses for different SNe Ia could vary by a
factor of ten (e.g., $M_{\rm Ni}=0.1 - 1.3$ $M_{\odot}$), which cannot be
explained in terms of the standard Chandrasekhar-mass model (with a $^{56}$Ni
mass production of 0.4 -- 0.8 $M_{\odot}$). Different explosion and/or
progenitor models are clearly required for various SNe Ia, in particular, for
those extremely nickel-poor and nickel-rich producers. The nickel-rich (with
$M_{\rm Ni}$ $>$ 0.8 $M_{\odot}$) SNe Ia are very luminous and may have massive
progenitors exceeding the Chandrasekhar-mass limit since extra progenitor fuel
is required to produce more $^{56}$Ni to power the light curve. This is also
consistent with the finding that the intrinsically bright SNe Ia prefer to
occur in stellar environments of young and massive stars. For example, 75% SNe
Ia in spirals have $\Delta m_{15} < 1.2$ while this ratio is only 18% in E/S0
galaxies. On the other hand, the nickel-poor SNe Ia (with $M_{\rm Ni}$ $<$ 0.2
$M_{\odot}$) may invoke the sub-Chandrasekhar model, as most of them were found
in early-type E/S0 galaxies dominated by the older and low-mass stellar
populations. This indicates that SNe Ia in spiral and E/S0 galaxies have
progenitors of different properties.


title: Dose, exposure time, and resolution in Serial X-ray Crystallography

abstract:
  The resolution of X-ray diffraction microscopy is limited by the maximum dose
that can be delivered prior to sample damage. In the proposed Serial
Crystallography method, the damage problem is addressed by distributing the
total dose over many identical hydrated macromolecules running continuously in
a single-file train across a continuous X-ray beam, and resolution is then
limited only by the available molecular and X-ray fluxes and molecular
alignment. Orientation of the diffracting molecules is achieved by laser
alignment. We evaluate the incident X-ray fluence (energy/area) required to
obtain a given resolution from (1) an analytical model, giving the count rate
at the maximum scattering angle for a model protein, (2) explicit simulation of
diffraction patterns for a GroEL-GroES protein complex, and (3) the frequency
cut off of the transfer function following iterative solution of the phase
problem, and reconstruction of an electron density map in the projection
approximation. These calculations include counting shot noise and multiple
starts of the phasing algorithm. The results indicate counting time and the
number of proteins needed within the beam at any instant for a given resolution
and X-ray flux. We confirm an inverse fourth power dependence of exposure time
on resolution, with important implications for all coherent X-ray imaging. We
find that multiple single-file protein beams will be needed for sub-nanometer
resolution on current third generation synchrotrons, but not on fourth
generation designs, where reconstruction of secondary protein structure at a
resolution of 0.7 nm should be possible with short exposures.


title: Aspects of causal viscous hydrodynamics

abstract:
  We investigate the phenomenology of freely expanding fluids, with different
material properties, evolving through the Israel-Stewart (IS) causal viscous
hydrodynamics, and compare our results with those obtained in the relativistic
Eckart-Landau-Navier-Stokes (ELNS) acausal viscous hydrodynamics. Through the
analysis of scaling invariants we give a definition of thermalization time
which can be self-consistently determined in viscous hydrodynamics. Next we
construct the solutions for one-dimensional boost-invariant flows. Expansion of
viscous fluids is slower than that of one-dimensional ideal fluids, resulting
in entropy production. At late times, these flows are reasonably well
approximated by solutions obtained in ELNS hydrodynamics. Estimates of initial
energy densities from observed final values are strongly dependent on the
dynamics one chooses. For the same material, and the same final state, IS
hydrodynamics gives the smallest initial energy density. We also study
fluctuations about these one-dimensional boost-invariant backgrounds; they are
damped in ELNS hydrodynamics but can become sound waves in IS hydrodynamics.
The difference is obvious in power spectra due to clear signals of
wave-interference in IS hydrodynamics, which is completely absent in ELNS
dynamics.


title:
Radio Synchrotron Emission from Secondary Leptons in the Vicinity of Sgr
  A*

abstract:
  A point-like source of ~TeV gamma-rays has recently been seen towards the
Galactic center by HESS and other air Cerenkov telescopes. In recent work
(Ballantyne et al. 2007), we demonstrated that these gamma-rays can be
attributed to high-energy protons that (i) are accelerated close to the event
horizon of the central black hole, Sgr A*, (ii) diffuse out to ~pc scales, and
(iii) finally interact to produce gamma-rays. The same hadronic collision
processes will necessarily lead to the creation of electrons and positrons.
Here we calculate the synchrotron emissivity of these secondary leptons in the
same magnetic field configuration through which the initiating protons have
been propagated in our model. We compare this emission with the observed ~GHz
radio spectrum of the inner few pc region which we have assembled from archival
data and new measurements we have made with the Australia Telescope Compact
Array. We find that our model predicts secondary synchrotron emission with a
steep slope consistent with the observations but with an overall normalization
that is too large by a factor of ~ 2. If we further constrain our theoretical
gamma-ray curve to obey the implicit EGRET upper limit on emission from this
region we predict radio emission that is consistent with observations, i.e.,
the hadronic model of gamma ray emission can, simultaneously and without
fine-tuning, also explain essentially all the diffuse radio emission detected
from the inner few pc of the Galaxy.


title:
The Impact of Channel Feedback on Opportunistic Relay Selection for
  Hybrid-ARQ in Wireless Networks

abstract:
  This paper presents a decentralized relay selection protocol for a dense
wireless network and describes channel feedback strategies that improve its
performance. The proposed selection protocol supports hybrid
automatic-repeat-request transmission where relays forward parity information
to the destination in the event of a decoding error. Channel feedback is
employed for refining the relay selection process and for selecting an
appropriate transmission mode in a proposed adaptive modulation transmission
framework. An approximation of the throughput of the proposed adaptive
modulation strategy is presented, and the dependence of the throughput on
system parameters such as the relay contention probability and the adaptive
modulation switching point is illustrated via maximization of this
approximation. Simulations show that the throughput of the proposed selection
strategy is comparable to that yielded by a centralized selection approach that
relies on geographic information.


title: Motion of Hexagonal Pencil on an Inclined Plane

abstract:
  This paper has been withdrawn by the author(s), due a crucial sign error in
Eqn. 1.


title:
Fluctuation of the Top Location and Avalanches in the Formation Process
  of a Sandpile

abstract:
  We investigate the formation processes of a sandpile using numerical
simulation. We find a new relation between the fluctuation of the motion of the
top and the surface state of a sandpile. The top moves frequently as particles
are fed one by one every time interval T. The time series of the top location
has the power spectrum which obeys a power law, S(f)~f^{\alpha}, and its
exponent \alpha depends on T and the system size w. The surface state is
characterized by two time scales; the lifetime of an avalanche, T_{a}, and the
time required to cause an avalanche, T_{s}. The surface state is fluid-like
when T_{a}~T_{s}, and it is solid-like when T_{a}<<T_{s}. Our numerical results
show that \alpha is a function of T_{s}/T_{a}.


title: Unbinding transitions of multicomponent membranes and strings

abstract:
  We present a theory of unbinding transitions for membranes that interact via
short and long receptor/ligand bonds. The detail of unbinding behavior of the
membranes is governed by the binding energies and concentrations of receptors
and ligands. We investigate the unbinding behavior of these membranes with
Monte Carlo simulations and via a comparison with strings. We derive the
scaling laws for strings analytically. The exact analytic results provide
scaling estimate for membranes in the vicinity of the critical point.


title: Separating populations with wide data: A spectral analysis

abstract:
  In this paper, we consider the problem of partitioning a small data sample
drawn from a mixture of $k$ product distributions. We are interested in the
case that individual features are of low average quality $\gamma$, and we want
to use as few of them as possible to correctly partition the sample. We analyze
a spectral technique that is able to approximately optimize the total data
size--the product of number of data points $n$ and the number of features
$K$--needed to correctly perform this partitioning as a function of $1/\gamma$
for $K>n$. Our goal is motivated by an application in clustering individuals
according to their population of origin using markers, when the divergence
between any two of the populations is small.


title: Undercomplete Blind Subspace Deconvolution via Linear Prediction

abstract:
  We present a novel solution technique for the blind subspace deconvolution
(BSSD) problem, where temporal convolution of multidimensional hidden
independent components is observed and the task is to uncover the hidden
components using the observation only. We carry out this task for the
undercomplete case (uBSSD): we reduce the original uBSSD task via linear
prediction to independent subspace analysis (ISA), which we can solve. As it
has been shown recently, applying temporal concatenation can also reduce uBSSD
to ISA, but the associated ISA problem can easily become `high dimensional'
[1]. The new reduction method circumvents this dimensionality problem. We
perform detailed studies on the efficiency of the proposed technique by means
of numerical simulations. We have found several advantages: our method can
achieve high quality estimations for smaller number of samples and it can cope
with deeper temporal convolutions.


title: Rare Kaon Decays Beyond the Standard Model

abstract:
  The rare kaon decays K_L -> pi^0 nu {bar nu}, K^+ -> pi^+ nu {bar nu}, K_L ->
pi^0 e^+ e^- and K_L -> pi^0 mu^+ mu^- are theoretically very clean and, being
strongly CKM suppressed, highly sensitive to New Physics (NP). Recent Flavour
Physics analyses show that they represent unique probes for revealing NP
effects and to provide information on the NP flavour structure. After a brief
discussion of the main properties that make rare K decays so promising and of
the basic ideas of the most interesting NP models, we review the results of
recent phenomenological analyses both within and beyond the framework of
Minimal Flavour Violation (MFV), where the sources of flavour violation are the
same as in the Standard Model. Within MFV we present the expectations found for
rare K decays from a model-independent analysis and in three MFV models: the
Littlest Higgs (LH) model, the (extra-dimension) Appelquist-Cheng-Dobrescu
model and the Minimal Supersymmetric Standard Model (MSSM) with MFV. Beyond
MFV, we discuss the results recently found within the MSSM (without MFV), the
LH model with T-parity (LHT) and the 3-3-1 (Z') model. While in MFV models only
small (<30%) NP effects are allowed in the branching ratios of K_L -> pi^0 nu
{bar nu}, K^+ -> pi^+ nu {bar nu}, K_L -> pi^0 e^+ e^- and K_L -> pi^0 mu^+
mu^-, beyond MFV, in particular in the MSSM and in the LHT model, large (up to
an order of magnitude) enhancements w.r.t. the SM turn out to be possible.


title: Bell's inequality test with time-delayed two-particle correlations

abstract:
  Adopting the frame of mesoscopic physics, we describe a Bell type experiment
involving time-delayed two-particle correlation measurements. The
indistinguishability of quantum particles results in a specific interference
between different trajectories. We show how the non-locality in the
time-delayed correlations due to the indistinguishability of the quantum
particles manifests itself in the violation of a Bell inequality, where the
degree of violation is related to the accuracy of the measurement. We
demonstrate how the interrelation between the orbital- and the spin exchange
symmetry can by exploited to infer knowledge on spin-entanglement from a
measurement of orbital entanglement.


title: Dijet correlations in $pp$ collisions at RHIC

abstract:
  We compare results of $k_t$-factorization approach and next-to-leading order
collinear-factorization approach for dijet correlations in proton-proton
collisions at RHIC energies. We discuss correlations in azimuthal angle as well
as correlations in two-dimensional space of transverse momenta of two jets.
Some $k_t$-factorization subprocesses are included for the first time in the
literature. Different unintegrated gluon/parton distributions are used in the
$k_t$-factorization approach. The results depend on UGDF/UPDF used. Limitations
due to leading jet condition are discussed.


title: Heavy quark correlations in hadronic collisions

abstract:
  We discuss results of the $k_t$ - factorization approach for heavy
quark-heavy antiquark correlations in proton-proton and proton-antiproton
collisions for RHIC, Tevatron and LHC. We consider correlations in the
azimuthal angle as well as in the two-dimensional space of transverse momentum
of heavy quark and heavy antiquark. We compare results obtained with the help
of different unintegrated parton distributions (UPDF) from the literature.


title:
The Stellar-Disk Electric (Short) Circuit: Observational Predictions for
  a YSO Jet Flow

abstract:
  We discuss the star-disk electric circuit for a young stellar object (YSO)
and calculate the expected torques on the star and the disk. We obtain the same
disk magnetic field and star-disk torques as given by standard
magnetohydrodynamic (MHD) analysis. We show how a short circuit in the
star-disk electric circuit may produce a magnetically-driven jet flow from the
inner edge of a disk surrounding a young star.
  An unsteady bipolar jet flow is produced that flows perpendicular to the disk
plane. Jet speeds of order hundreds of kilometres per second are possible,
while the outflow mass loss rate is proportional to the mass accretion rate and
is a function of the disk inner radius relative to the disk co-rotation radius.


title: Non-archimedean analytification of algebraic spaces

abstract:
  It is now a classical result that an algebraic space locally of finite type
over $\mathbf{C}$ is analytifiable if and only if it is locally separated. In
this paper we study non-archimedean analytifications of algebraic spaces. We
construct a quotient for any etale non-archimedean analytic equivalence
relation whose diagonal is a closed immersion, and deduce that any separated
algebraic space locally of finite type over any non-archimedean field $k$ is
analytifiable in both the category of rigid spaces and the category of analytic
spaces over $k$. Also, though local separatedness remains a necessary condition
for analytifiability in either of these categories, we present many surprising
examples of non-analytifiable locally separated smooth algebraic spaces over
$k$ that can even be defined over the prime field.


title: Photon-jet correlations in hadronic collisions

abstract:
  We compare results of $k_t$-factorization approach and next-to-leading order
collinear-factorization approach for photon-jet correlations in $pp$ and $p
\bar p$ collisions at RHIC, Tevatron and LHC energies. We discuss correlations
in azimuthal angle as well as in two-dimensional space of transverse momenta of
photon and jet. Different unintegrated parton distributions (UPDF) are included
in the $k_t$-factorization approach. The results depend on UPDFs used. The
results of NLO collinear-factorization are shown for comparison.


title: The SSM Toolbox for Matlab

abstract:
  State Space Models (SSM) is a MATLAB 7.0 software toolbox for doing time
series analysis by state space methods. The software features fully interactive
construction and combination of models, with support for univariate and
multivariate models, complex time-varying (dynamic) models, non-Gaussian
models, and various standard models such as ARIMA and structural time-series
models. The software includes standard functions for Kalman filtering and
smoothing, simulation smoothing, likelihood evaluation, parameter estimation,
signal extraction and forecasting, with incorporation of exact initialization
for filters and smoothers, and support for missing observations and multiple
time series input with common analysis structure. The software also includes
implementations of TRAMO model selection and Hillmer-Tiao decomposition for
ARIMA models. The software will provide a general toolbox for doing time series
analysis on the MATLAB platform, allowing users to take advantage of its
readily available graph plotting and general matrix computation capabilities.


title: How To Kill a Penguin

abstract:
  Within constrained minimal-flavor-violation the large destructive
flavor-changing Z-penguin managed to survive eradication so far. We give a
incisive description of how to kill it using the precision measurements of the
Z -> b anti-b pseudo observables. The derived stringent range for the
non-standard contribution to the universal Inami-Lim function C leads to tight
two-sided limits for the branching ratios of all Z-penguin dominated
flavor-changing K- and B-decays.


title:
Analysis of a recent experimental test of Bell inequalities violating
  quantum predictions

abstract:
  A recent experiment by Brida et al. (arXiv:0705.0439 [quant-ph]) is analyzed
with the conclusion that is shows a violation of standard quantum predictions.
A simple local hidden variables model is studied which is compatible with the
empirical results and fits fairly well the deviation from the quantum
predictions.


title:
Estimation of the Birefringence Change in Crystals Induced by
  Gravitation Field

abstract:
  The effect of gravitation field of spherically symmetric mass on the
birefringent properties of crystals has been analysed. It has been shown that
the gravitation field with spherical symmetry can lead to a change of
birefringence in anisotropic media.


title: Products of Brauer Severi surfaces

abstract:
  Let $\{P_i\}_{1 \leq i \leq r}$ and $\{Q_i\}_{1 \leq i \leq r}$ be two
collections of Brauer Severi surfaces (resp. conics) over a field $k$. We show
that the subgroup generated by the $P_i's$ in $Br(k)$ is the same as the
subgroup generated by the $Q_i's$ \iff $\Pi P_i $ is birational to $\Pi Q_i$.
Moreover in this case $\Pi P_i$ and $\Pi Q_i$ represent the same class in
$M(k)$, the Grothendieck ring of $k$-varieties. The converse holds if
$char(k)=0$. Some of the above implications also hold over a general noetherian
base scheme.


title: Daily Observations of Interstellar Scintillation in PSR B0329+54

abstract:
  Quasi-continuous observations of PSR B03239+54 over 20 days using the Nanshan
25-m telescope at 1540 MHz have been used to study the effects of refractive
scintillation on the pulsar flux density and diffractive scintillation
properties. Dynamic spectra were obtained from datasets of 90 min duration and
diffractive parameters derived from a two-dimensional auto-correlation
analysis. Secondary spectra were also computed but these showed no significant
evidence for arc structure. Cross correlations between variations in the
derived parameters were much lower than predicted by thin screen models and in
one case was of opposite sign to the prediction. Observed modulation indices
were larger than predicted by thin screen models with a Kolmogorov fluctuation
spectrum. Structure functions were computed for the flux density, diffractive
timescale and decorrelation bandwidth. These indicated a refractive timescale
of $8\pm 2$ h, much shorter than predicted by the thin screen model. The
measured structure-function slope of $0.4\pm 0.2$ is also inconsistent with
scattering by a single thin screen for which a slope of 2.0 is expected. All
observations are consistent with scattering by an extended medium having a
Kolmogorov fluctuation spectrum which is concentrated towards the pulsar. This
interpretation is also consistent with recent observations of multiple diffuse
scintillation arcs for this pulsar.


title:
Incoherent mid-infrared charge excitation and the high energy anomaly in
  the photoemission spectra of cuprates

abstract:
  On the basis of a semi-phenomenological model, it is argued that the high
energy anomaly observed in recent photoemission experiments on cuprates is
caused by interaction with an overdamped bosonic mode in the mid-infrared
region of the spectrum. Analysis of optical conductivity allows to connect this
excitation to the incoherent charge response reported for the majority of high
Tc materials and some other perovskites. We show that its large damping is an
essential feature responsible for the "waterfall" dispersion and linewidth of
the spectral weight.


title: Ruppeiner Geometry of RN Black Holes: Flat or Curved?

abstract:
  In some recent studies \cite{aman1, aman2, aman3}, Aman {\it et al.} used the
Ruppeiner scalar as a measure of underlying interactions of
Reissner-Nordstr\"{o}m black holes, indicating that it is a non-interacting
statistical system for which classical thermodynamics could be used at any
scale. Here, we show that if we use the complete set of thermodynamic
variables, a non-flat state space will be produced. Furthermore, the Ruppeiner
curvature diverges at extremal limits, as it would for other types of black
holes.


title: Complexity test modules

abstract:
  A method is provided for computing an upper bound of the complexity of a
module over a local ring, in terms of vanishing of certain cohomology modules.
We then specialize to complete intersections, which are precisely the rings
over which all modules have finite complexity.


title:
Sound Speeds, Cracking and Stability of Self-Gravitating Anisotropic
  Compact Objects

abstract:
  Using the the concept of cracking we explore the influence of density
fluctuations and local anisotropy have on the stability of local and non-local
anisotropic matter configurations in general relativity. This concept,
conceived to describe the behaviour of a fluid distribution just after its
departure from equilibrium, provides an alternative approach to consider the
stability of selfgravitating compact objects. We show that potentially unstable
regions within a configuration can be identify as a function of the difference
of propagations of sound along tangential and radial directions. In fact, it is
found that these regions could occur when, at particular point within the
distribution, the tangential speed of sound is greater than radial one.


title:
About agreement of PYTHIA and the experimental results in $e^+e^-$
  annihilation to hadrons

abstract:
  The experimental charged particles multiplicity distributions in $e^+e^-$
annihilation to hadrons are compared with the distributions obtained by PYTHIA.
The ratio $\chi^2$/degrees of freedom is calculated for 6 energies at
$\sqrt{s}$ 14 -- 206.2 GeV. The necessity of more subtle tuning of PYTHIA at
the energy of $Z^0$ peak is discussed.


title:
Reconstruction of Quantum Well Potentials via the Intertwining Operator
  Technique

abstract:
  One of the most important issues of quantum engineering is the construction
of low-dimensional structures possessing desirable properties. For example, in
different areas of possible applications of the structures containing quantum
wells (QW), there is need to have QW energy spectrum, which is predetermined.
  Then the following question arises: can one reconstruct the shape of QW which
supports this spectrum? We outline the possible strategy of the QW potential
shape reconstruction, if the spectrum of QW is given in advance. The proposed
approach is based on the combination of different techniques such as Inverse
Scattering Problem Method, Darboux and Liouville transformation. It enables to
take into account the space-variable dependent effective mass of charge
carriers and allows the kinetic energy operator to be of non-Hermitian as well
as Hermitian form. The proposed technique allows to construct phase-equivalent
potentials, to add the new bounded states to (or remove some of them from) the
spectrum supported by an initial potential and provides a systematic procedure
for generating new exactly solvable models.


title: Thermodynamics of Few-Particle Systems

abstract:
  We consider the wide class of few-particle systems that have some analog of
the thermodynamic laws. These systems are characterized by the distributions
that are determined by the Hamiltonian and satisfy the Liouville equation.
Few-particle systems of this class are described by a non-holonomic constraint:
the power of non-potential forces is directly proportional to the velocity of
the elementary phase volume change. The coefficient of this proportionality is
determined by the Hamiltonian. In the general case, the examples of the
few-particle systems of this class are the constant temperature systems,
canonical-dissipative systems, and Fermi-Bose classical systems.


title:
Nonperturbative Scaling Theory of Free Magnetic Moment Phases in
  Disordered Metals

abstract:
  The crossover between a free magnetic moment phase and a Kondo phase in low
dimensional disordered metals with dilute magnetic impurities is studied.
  We perform a finite size scaling analysis of the distribution of the Kondo
temperature as obtained from a numerical renormalization group calculation of
the local magnetic susceptibility and from the solution of the self-consistent
Nagaoka-Suhl equation. We find a sizable fraction of free (unscreened) magnetic
moments when the exchange coupling falls below a disorder-dependent critical
value $J_{\rm c}$. Our numerical results show that between the free moment
phase due to Anderson localization and the Kondo screened phase there is a
phase where free moments occur due to the appearance of random local pseudogaps
at the Fermi energy whose width and power scale with the elastic scattering
rate $1/\tau$.


title: Quantum theory for spatial motion of polaritons in inhomogeneous fields

abstract:
  Polaritons are the collective excitations of many atoms dressed by resonant
photons, which can be used to explain the slow light propagation with the
mechanism of electromagnetically induced transparency. As quasi-particles,
these collective excitations possess the typical feature of the matter
particles, which can be reflected and deflected by the inhomogeneous medium in
its spatial motion with some velocity. In this paper we develop a quantum
theory to systematically describe the spatial motion of polaritons in
inhomogeneous magnetic and optical fields. This theoretical approach treats
these quasi-particles through an effective Schr\"{o}dinger equation with
anisotropic depression that the longitudinal motion is like a
ultra-relativistic motion of a "slow light velocity" while the transverse
motion is of non-relativity with certain effective mass. We find that, after
passing through the EIT medium, the light ray bends due to the
spatial-dependent profile of external field. This phenomenon explicitly
demonstrates the exotic corpuscular property of polaritons with anisotropic
nature.


title:
The Thermodynamic Casimir Effect in $^4$He Films near $T_\lambda$: Monte
  Carlo Results

abstract:
  The universal finite-size scaling function of the critical Casimir force for
the three dimensional XY universality class with Dirichlet boundary conditions
is determined using Monte Carlo simulations. The results are in excellent
agreement with recent experiments on $^4$He Films at the superfluid transition
and with available theoretical predictions.


title: NP by means of lifts and shadows

abstract:
  We show that every NP problem is polynomially equivalent to a simple
combinatorial problem: the membership problem for a special class of digraphs.
These classes are defined by means of shadows (projections) and by finitely
many forbidden colored (lifted) subgraphs. Our characterization is motivated by
the analysis of syntactical subclasses with the full computational power of NP,
which were first studied by Feder and Vardi.
  Our approach applies to many combinatorial problems and it induces the
characterization of coloring problems (CSP) defined by means of shadows. This
turns out to be related to homomorphism dualities. We prove that a class of
digraphs (relational structures) defined by finitely many forbidden colored
subgraphs (i.e. lifted substructures) is a CSP class if and only if all the the
forbidden structures are homomorphically equivalent to trees. We show a
surprising richness of coloring problems when restricted to most frequent graph
classes. Using results of Ne\v{s}et\v{r}il and Ossona de Mendez for bounded
expansion classes (which include bounded degree and proper minor closed
classes) we prove that the restriction of every class defined as the shadow of
finitely many colored subgraphs equals to the restriction of a coloring (CSP)
class.


title:
The AGN nature of 11 out of 12 Swift/RXTE unidentified sources through
  optical and X-ray spectroscopy

abstract:
  The Swift Burst Alert Telescope (BAT) is performing a high Galactic latitude
survey in the 14-195 keV band at a flux limit of ~10^{-11} erg cm^{-2} s^{-1},
leading to the discovery of new high energy sources, most of which have not so
far been properly classified. A similar work has also been performed with the
RXTE slew survey leading to the discovery of 68 sources detected above 8 keV,
many of which are still unclassified. Follow-up observations with the Swift
X-ray Telescope (XRT) provide, for many of these objects, source localization
with a positional accuracy of few arcsec, thus allowing the search for optical
counterparts to be more efficient and reliable. We present the results of
optical/X-ray follow-up studies of 11 Swift BAT detections and one AGN detected
in the RXTE Slew Survey, aimed at identifying their counterparts and at
assessing their nature. These data allowed, for the first time, the optical
classification of 8 objects and a distance determination for 3 of them. For
another object, a more refined optical classification than that available in
the literature is also provided. For the remaining sources, optical
spectroscopy provides a characterization of the source near in time to the
X-ray measurement. The sample consists of 6 Seyfert 2 galaxies, 5 Seyferts of
intermediate type 1.2-1.8, and one object of Galactic nature - an Intermediate
Polar (i.e., magnetic) Cataclysmic Variable. Out of the 11 AGNs, 8 (~70%)
including 2 Seyferts of type 1.2 and 1.5, are absorbed with NH > 10^{22}
cm^{-2}. Up to 3 objects could be Compton thick (i.e. NH > 1.5 x 10^{24}
cm^{-2}), but only in one case (Swift J0609.1-8636) does all the observational
evidence strongly suggests this possibility.


title: Geometrization of quantum formalism

abstract:
  The hypothesis is suggested that the equation for the Dirac free wave field
is, in fact, a group-theoretical relation describing propagation of specific
microscopic deviations of space geometry from the euclidean one (closed
topological manifolds). The Dirac equation for a hydrogen atom can also be
interpreted as a relation that accounts for the symmetry properties of a piece
of curved space. Within the framework of this concept, atoms have no any
pointlike particles (electrons) inside, and the gauge invariance of
electromagnetic field proves to be the natural consequence of the basic
principles of the proposed geometrical approach.


title:
Stability of Hodge bundles and a numerical characterization of Shimura
  varieties

abstract:
  Consider a family f:A --> U of g-dimensional abelian varieties over a
quasiprojective manifold U. Suppose that the induced map from U to the moduli
scheme of polarized abelian varieties is generically finite and that there is a
projective manifold Y, containing U as the complement of a normal crossing
divisor S, such that the sheaf of logarithmic one forms is nef and that its
determinant is ample with respect to U. We characterize whether $U$ is a
Shimura variety by numerical data attached to the variation of Hodge
structures, rather than by properties of the map from U to the moduli scheme or
by the existence of CM points. More precisely, we show that U is a Shimura
variety, if and only if two conditions hold. First, each irreducible local
subsystem V of the complex weight one variation of Hodge structures is either
unitary or satisfies the Arakelov equality. Secondly, for each factor M in the
universal cover of U whose tangent bundle behaves like the one of a complex
ball, an iterated Kodaira-Spencer map associated with V has minimal possible
length in the direction of M.


title:
Classification of hyperfinite factors up to completely bounded
  isomorphism of their preduals

abstract:
  In this paper we consider the following problem: When are the preduals of two
hyperfinite (=injective) factors $\M$ and $\N$ (on separable Hilbert spaces)
cb-isomorphic (i.e., isomorphic as operator spaces)? We show that if $\M$ is
semifinite and $\N$ is type III, then their preduals are not cb-isomorphic.
Moreover, we construct a one-parameter family of hyperfinite type
III$_0$-factors with mutually non cb-isomorphic preduals, and we give a
characterization of those hyperfinite factors $\M$ whose preduals are
cb-isomorphic to the predual of the unique hyperfinite type III$_1$-factor. In
contrast, Christensen and Sinclair proved in 1989 that all infinite dimensional
hyperfinite factors with separable preduals are cb-isomorphic. More recently
Rosenthal, Sukochev and the first-named author proved that all hyperfinite type
III$_\lambda$-factors, where $0< \lambda\leq 1$, have cb-isomorphic preduals.


title: The Disk and Extraplanar Regions of NGC 2403

abstract:
  Wide field images obtained with WIRCam and MegaCam on the
Canada-France-Hawaii Telescope are used to probe the spatial distribution of
young stars in the Sc galaxy NGC 2403. Bright main sequence stars and blue
supergiants are detected out to projected galactocentric distances of ~14 kpc
(~7 disk scale lengths) along the major axis. The star formation rate (SFR) in
the disk of NGC 2403 during the past 10 Myr has been 1 solar masses per year
based on the number of bright main sequence stars. The radially-averaged number
density of red supergiants (RSGs) per unit r-band surface brightness is
constant throughout the disk, indicating that (1) RSGs follow the integrated
r-band light, and (2) the SFR per unit mass has been constant with radius when
averaged over time scales of a few tens of millions of years. The mean color of
RSGs varies with galactocentric distance, suggesting that there is a
metallicity gradient among recently formed stars. A comparison of the
radially-averaged number density of bright main sequence stars also indicates
that the SFR per unit stellar mass in NGC 2403 has been ~3 times higher than in
NGC 247 during recent epochs, and this is in rough agreement with what would be
predicted from the far infrared fluxes of these galaxies. Finally, the data are
used to investigate the extraplanar regions of NGC 2403. A population of M
giants with peak brightness M_K = -8 is detected at projected distances between
12 and 14 kpc above the disk plane, and six new globular cluster candidates are
identified.


title: Cosmological Constraint on the Effective Number of Neutrino Species

abstract:
  We discuss constraints on the effective number of neutrino species Nnu from
recent cosmological observations such as CMB, LSS, BBN, including our own
analysis which uses the WMAP and the Luminous Red Galaxy power spectrum data.
We also discuss their implications on some non-standard cosmological scenarios
such as the low (MeV-scale) reheating temperature scenario and the scenario
with decaying particles between BBN and structure formation.


title: N=8 supersymmetric mechanics on the sphere S^3

abstract:
  Starting from quaternionic N=8 supersymmetric mechanics we perform a
reduction over a bosonic radial variable, ending up with a nonlinear off-shell
supermultiplet with three bosonic end eight fermionic physical degrees of
freedom. The geometry of the bosonic sector of the most general sigma-model
type action is described by an arbitrary function obeying the three dimensional
Laplace equation on the sphere S^3. Among the bosonic components of this new
supermultiplet there is a constant which gives rise to potential terms. After
dualization of this constant one may come back to the supermultiplet with four
physical bosons. However, this new supermultiplet is highly nonlinear. The
geometry of the corresponding sigma-model action is briefly discussed.


title: Coupled phantom field in loop quantum cosmology

abstract:
  A model of phantom scalar field dark energy under exponential potential
coupling to barotropic dark matter fluid in loop quantum cosmology is addressed
here. We derive a closed-autonomous system for cosmological dynamics in this
scenario. The expansion in loop quantum universe has a bounce even in presence
of the phantom field. The greater decaying from dark matter to dark phantom
energy results in greater energy storing in the phantom field. This results in
further turning point of the field. Greater coupling also delays bouncing time.
In the case of phantom decaying, oscillation in phantom density makes small
oscillation in the increasing matter density.


title:
Investigating diffractive W production in hadron-hadron collisions at
  high energies

abstract:
  We compute the hard diffractive hadroproduction of bosons W at high energies
using Regge factorization and taking into account multiple Pomeron exchange
corrections. The ratio of diffractive to non-diffractive W production agrees
with the current Tevatron data and a prediction for the LHC is presented.


title:
Entanglement and Timing-Based Mechanisms in the Coherent Control of
  Scattering Processes

abstract:
  The coherent control of scattering processes is considered, with electron
impact dissociation of H$_2^+$ used as an example. The physical mechanism
underlying coherently controlled stationary state scattering is exposed by
analyzing a control scenario that relies on previously established entanglement
requirements between the scattering partners. Specifically, initial state
entanglement assures that all collisions in the scattering volume yield the
desirable scattering configuration. Scattering is controlled by preparing the
particular internal state wave function that leads to the favored collisional
configuration in the collision volume. This insight allows coherent control to
be extended to the case of time-dependent scattering. Specifically, we identify
reactive scattering scenarios using incident wave packets of translational
motion where coherent control is operational and initial state entanglement is
unnecessary. Both the stationary and time-dependent scenarios incorporate
extended coherence features, making them physically distinct. From a
theoretical point of view, this work represents a large step forward in the
qualitative understanding of coherently controlled reactive scattering. From an
experimental viewpoint, it offers an alternative to entanglement-based control
schemes. However, both methods present significant challenges to existing
experimental technologies.


title:
Coherent Control and Entanglement in the Attosecond Electron Recollision
  Dissociation of D2+

abstract:
  We examine the attosecond electron recollision dissociation of D2+ recently
demonstrated experimentally [H. Niikura et al., Nature (London) 421, 826
(2003)] from a coherent control perspective. In this process, a strong laser
field incident on D2 ionizes an electron, accelerates the electron in the laser
field to eV energies, and then drives the electron to recollide with the parent
ion, causing D2+ dissociation. A number of results are demonstrated. First, a
full dimensional Strong Field Approximation (SFA) model is constructed and
shown to be in agreement with the original experiment. This is then used to
rigorously demonstrate that the experiment is an example of coherent pump-dump
control. Second, extensions to bichromatic coherent control are proposed by
considering dissociative recollision of molecules prepared in a coherent
superposition of vibrational states. Third, by comparing the results to similar
scenarios involving field-free attosecond scattering of independently prepared
D2+ and electron wave packets, recollision dissociation is shown to provide an
example of wave-packet coherent control of reactive scattering. Fourth, this
analysis makes clear that it is the temporal correlations between the continuum
electron and D2+ wave packet, and not entanglement, that are crucial for the
sub-femtosecond probing resolution demonstrated in the experiment. This result
clarifies some misconceptions regarding the importance of entanglement in the
recollision probing of D2+. Finally, signatures of entanglement between the
recollision electron and the atomic fragments, detectable via coincidence
measurements, are identified.


title:
Radiation- and Phonon-Bottleneck-Induced Tunneling in the Fe8
  Single-Molecule Magnet

abstract:
  We measure magnetization changes in a single crystal of the single-molecule
magnet Fe8 when exposed to intense, short (<20 $\mu$s) pulses of microwave
radiation resonant with the m = 10 to 9 transition. We find that radiation
induces a phonon bottleneck in the system with a time scale of ~5 $\mu$s. The
phonon bottleneck, in turn, drives the spin dynamics, allowing observation of
thermally assisted resonant tunneling between spin states at the 100-ns time
scale. Detailed numerical simulations quantitatively reproduce the data and
yield a spin-phonon relaxation time of T1 ~ 40 ns.


title:
Stationarity and Self-similarity Characterization of the Set-indexed
  Fractional Brownian Motion

abstract:
  The set-indexed fractional Brownian motion (sifBm) has been defined by
Herbin-Merzbach (2006) for indices that are subsets of a metric measure space.
In this paper, the sifBm is proved to statisfy a strenghtened definition of
increment stationarity. This new definition for stationarity property allows to
get a complete characterization of this process by its fractal properties: The
sifBm is the only set-indexed Gaussian process which is self-similar and has
stationary increments.
  Using the fact that the sifBm is the only set-indexed process whose
projection on any increasing path is a one-dimensional fractional Brownian
motion, the limitation of its definition for a self-similarity parameter
0<H<1/2 is studied, as illustrated by some examples. When the indexing
collection is totally ordered, the sifBm can be defined for 0<H<1.


title: On a class of gauge theories

abstract:
  We give a framework to describe gauge theory in which a nonassociative
Moufang loop takes the place of the structure group. The structure of such
gauge theory has many formal similarities with that of Yang-Mills theory. We
extend the gauge invariance to this theory and construct an on-shell version of
N=1 supersymmetric gauge theory.


title: An exact geometric mass formula

abstract:
  We show an exact geometric mass formula for superspecial points in the
reduction of any quaternionic Shimura variety modulo at a good prime $p$.


title: Emergence of time and Observable physics

abstract:
  This is a philosophy paper rather than mathematical physics work. I will
publish it in some other place.


title: Baxter operator and Archimedean Hecke algebra

abstract:
  In this paper we introduce Baxter integral Q-operators for finite-dimensional
Lie algebras gl(n+1) and so(2n+1). Whittaker functions corresponding to these
algebras are eigenfunctions of the Q-operators with the eigenvalues expressed
in terms of Gamma-functions. The appearance of the Gamma-functions is one of
the manifestations of an interesting connection between Mellin-Barnes and
Givental integral representations of Whittaker functions, which are in a sense
dual to each other. We define a dual Baxter operator and derive a family of
mixed Mellin-Barnes-Givental integral representations. Givental and
Mellin-Barnes integral representations are used to provide a short proof of the
Friedberg-Bump and Bump conjectures for G=GL(n+1) proved earlier by Stade. We
also identify eigenvalues of the Baxter Q-operator acting on Whittaker
functions with local Archimedean L-factors. The Baxter Q-operator introduced in
this paper is then described as a particular realization of the explicitly
defined universal Baxter operator in the spherical Hecke algebra H(G(R),K), K
being a maximal compact subgroup of G. Finally we stress an analogy between
Q-operators and certain elements of the non-Archimedean Hecke algebra
H(G(Q_p),G(Z_p)).


title:
OrfMapper: A Web-Based Application for Visualizing Gene Clusters on
  Metabolic Pathway Maps

abstract:
  Computational analyses of, e.g., genomic, proteomic, or metabolomic data,
commonly result in one or more sets of candidate genes, proteins, or enzymes.
These sets are often the outcome of clustering algorithms. Subsequently, it has
to be tested if, e.g., the candidate gene-products are members of known
metabolic processes. With OrfMapper we provide a powerful but easy-to-use,
web-based database application, that supports such analyses. All services
provided by OrfMapper are freely available at http://www.orfmapper.com


title: Relations between tautological cycles on Jacobians

abstract:
  We study tautological cycle classes on the Jacobian of a curve. We prove a
new result about the ring of tautological classes on a general curve that
allows, among other things, easy dimension calculations and leads to some
general results about the structure of this ring. Next we obtain a vanishing
result for some of the generating classes p_i; this gives an improvement of an
earlier result of Herbaut. Finally we lift a result of Herbaut and van der
Geer-Kouvidakis to the Chow ring (as opposed to its quotient modulo algebraic
equivalence) and we give a method to obtain further explicit cycle relations.
As an ingredient for this we prove a theorem about how Polishchuk's operator D
lifts to the tautological subalgebra of Chow(J).


title: Hypocomputation

abstract:
  Hypercomputational formal theories will, clearly, be both structurally and
foundationally different from the formal theories underpinning computational
theories. However, many of the maps that might guide us into this strange realm
have been lost. So little work has been done recently in the area of
metamathematics, and so many of the previous results have been folded into
other theories, that we are in danger of loosing an appreciation of the broader
structure of formal theories. As an aid to those looking to develop
hypercomputational theories, we will briefly survey the known landmarks both
inside and outside the borders of computational theory. We will not focus in
this paper on why the structure of formal theory looks the way it does. Instead
we will focus on what this structure looks like, moving from hypocomputational,
through traditional computational theories, and then beyond to
hypercomputational theories.


title:
Tight Bounds on the Average Length, Entropy, and Redundancy of
  Anti-Uniform Huffman Codes

abstract:
  In this paper we consider the class of anti-uniform Huffman codes and derive
tight lower and upper bounds on the average length, entropy, and redundancy of
such codes in terms of the alphabet size of the source. The Fibonacci
distributions are introduced which play a fundamental role in AUH codes. It is
shown that such distributions maximize the average length and the entropy of
the code for a given alphabet size. Another previously known bound on the
entropy for given average length follows immediately from our results.


title: Astronomical Image Processing with Array Detectors

abstract:
  We address the question of astronomical image processing from data obtained
with array detectors. We define and analyze the cases of evenly, regularly, and
irregularly sampled maps for idealized (i.e., infinite) and realistic (i.e.,
finite) detectors. We concentrate on the effect of interpolation on the maps,
and the choice of the kernel used to accomplish this task. We show how the
normalization intrinsic to the interpolation process must be carefully
accounted for when dealing with irregularly sampled grids. We also analyze the
effect of missing or dead pixels in the array, and their consequences for the
Nyquist sampling criterion.


title: The Assembly History of Massive Galaxies: What Do We Know?

abstract:
  Understanding the formation history of massive galaxies is one of most
popular and longstanding problems in astronomy, with observations and theory
addressing how and when these systems assembled. Since the most massive
galaxies in today's universe, with M_*> 10^11 M_0, are nearly all elliptical
with uniform old stellar populations, we must probe higher redshifts to
discover their full origins. A recent consensus has developed that nearly all
M_* > 10^11 M_0 galaxies we see today were established by z~1, with at most a
factor of two growth in stellar mass and number densities at lower redshifts.
We review the evidence for this, and discuss how recent observations of star
formation rates, colors, and morphologies of massive galaxies at z < 1 with M_*
> 10^11 M_0 show that these systems are still experiencing some evolution.
Massive galaxies undergo on average a single major merger at z < 1.5, and
roughly half are experiencing star formation at the same redshifts. The highest
mass galaxies, with M_* > 10^11.5 M_0, appear in similar abundance at z < 2,
suggesting that extremely massive galaxies are mostly formed very early in the
universe. Observations at z > 1.5 demonstrate that major galaxy mergers are the
primary method for assembling these massive galaxies, with nearly all of this
merging occurring at z > 2, with on average 4 to 5 major mergers taking place
at z = 1.5 - 3.


title:
The size of isoperimetric surfaces in 3-manifolds and a rigidity result
  for the upper hemisphere

abstract:
  We characterize the standard $\mathbb{S}^3$ as the closed Ricci-positive
3-manifold with scalar curvature at least 6 having isoperimetric surfaces of
largest area: $4\pi$. As a corollary we answer in the affirmative an
interesting special case of a conjecture of Min-Oo's on the scalar curvature
rigidity of the upper hemisphere..


title: Diffraction at HERA and implications for Tevatron and LHC

abstract:
  We describe new QCD fits to diffractive cross sections measured at HERA and
we use the parton densities derived from these fits to predict the shape of the
dijet mass fraction in double Pomeron exchange at the Tevatron. We discuss the
existence of exclusive events in this dijet channel and some prospects are
given for the LHC.


title:
In which shell-type SNRs should we look for gamma-rays and neutrinos
  from p-p collisions?

abstract:
  We present a simple analytic model for the various contributions to the
non-thermal emission from shell type SNRs, and show that this model's results
reproduce well the results of previous detailed calculations. We show that the
\geq 1 TeV gamma ray emission from the shell type SNRs RX J1713.7-3946 and RX
J0852.0-4622 is dominated by inverse-Compton scattering of CMB photons (and
possibly infra-red ambient photons) by accelerated electrons. Pion decay (due
to proton-proton collisions) is shown to account for only a small fraction,
\lesssim10^-2, of the observed flux, as assuming a larger fractional
contribution would imply nonthermal radio and X-ray synchrotron emission and
thermal X-ray Bremsstrahlung emission that far exceed the observed radio and
X-ray fluxes. Models where pion decay dominates the \geq 1 TeV flux avoid the
implied excessive synchrotron emission (but not the implied excessive thermal
X-ray Bremsstrahlung emission) by assuming an extremely low efficiency of
electron acceleration, K_ep \lesssim 10^-4 (K_ep is the ratio of the number of
accelerated electrons and the number of accelerated protons at a given energy).
We argue that observations of SNRs in nearby galaxies imply a lower limit of
K_ep \gtrsim 10^-3, and thus rule out K_ep values \lesssim 10^-4 (assuming that
SNRs share a common typical value of K_ep). It is suggested that SNRs with
strong thermal X-ray emission, rather than strong non-thermal X-ray emission,
are more suitable candidates for searches of gamma rays and neutrinos resulting
from proton-proton collisions. In particular, it is shown that the neutrino
flux from the SNRs above is probably too low to be detected by current and
planned neutrino observatories (Abridged).


title: Peak Quasisymmetric Functions and Eulerian Enumeration

abstract:
  Via duality of Hopf algebras, there is a direct association between peak
quasisymmetric functions and enumeration of chains in Eulerian posets. We study
this association explicitly, showing that the notion of $\cd$-index, long
studied in the context of convex polytopes and Eulerian posets, arises as the
dual basis to a natural basis of peak quasisymmetric functions introduced by
Stembridge. Thus Eulerian posets having a nonnegative $\cd$-index (for example,
face lattices of convex polytopes) correspond to peak quasisymmetric functions
having a nonnegative representation in terms of this basis. We diagonalize the
operator that associates the basis of descent sets for all quasisymmetric
functions to that of peak sets for the algebra of peak functions, and study the
$g$-polynomial for Eulerian posets as an algebra homomorphism.


title: Wronskian solutions to the KdV equation via B\"acklund transformation

abstract:
  In the paper we discuss the B\"acklund transformation of the KdV equation
between solitons and solitons, between negatons and negatons, between positons
and positons, between rational solution and rational solution, and between
complexitons and complexitons. We investigate the conditions that Wronskian
entries satisfy for the bilinear B\"acklund transformation of the KdV equation.
By choosing suitable Wronskian entries and the parameter in the bilinear
B\"acklund transformation, we obtain transformations between many kinds of
solutions.


title: Generalised parton distributions at HERA and prospects for COMPASS

abstract:
  We present a model of generalised parton distributions based on a forward
ansatz in the DGLAP region. We discuss some aspects of the parametrisations, as
the dependence in t, with factorised and non-factorised approaches, where t is
the square of the four-momentum exchanged at the hadron vertex. The predictions
of this model are then compared with DVCS cross sections from H1 and ZEUS, and
a related observable, the skewing factor, defined as the following ratio
imaginary amplitudes : $R \equiv {Im {\cal A} (\gamma^*+p \to \gamma
+p)\lfrestriction{t=0}} / {Im {\cal A} (\gamma^*+p \to \gamma^*
+p)\lfrestriction{t=0}}$. It is an interesting quantity including both the
non-forward kinematics and the non-diagonal effects. Finally, we discuss the
beam charge asymmetry, which is certainly the most sensitive observable to the
different hypothesis needed in the GPDs parametrisations. We show that the
approximations done for the t dependence lead to significant differences for
the predictions in the HERMES kinematic domain and prospects are given for
COMPASS.


title:
Information on mean, fluctuation and synchrony conveyed by a population
  of firing neurons

abstract:
  A population of firing neurons is expected to carry not only mean firing rate
but also its fluctuation and synchrony among neurons. In order to examine this
possibility, we have studied responses of neuronal ensembles to three kinds of
inputs: mean-, fluctuation- and synchrony-driven inputs. The generalized
rate-code model including additive and multiplicative noise (H. Hasegawa, Phys.
Rev. E {\bf 75}, 051904 (2007)) has been studied by direct simulations (DSs)
and the augmented moment method (AMM) in which equations of motion for mean
firing rate, fluctuation and synchrony are derived. Results calculated by the
AMM are in good agreement with those by DSs. The independent component analysis
(ICA) of our results has shown that mean firing rate, fluctuation (or
variability) and synchrony may carry independent information in the population
rate-code model. The input-output relation of mean firing rates is shown to
have higher sensitivity for larger multiplicative noise, as recently observed
in prefrontal cortex. A comparison is made between results obtained by the
integrate-and-fire (IF) model and our rate-code model. The relevance of our
results to experimentally obtained data is also discussed.


title:
Maximal planar scale-free Sierpinski networks with small-world effect
  and power-law strength-degree correlation

abstract:
  Many real networks share three generic properties: they are scale-free,
display a small-world effect, and show a power-law strength-degree correlation.
In this paper, we propose a type of deterministically growing networks called
Sierpinski networks, which are induced by the famous Sierpinski fractals and
constructed in a simple iterative way. We derive analytical expressions for
degree distribution, strength distribution, clustering coefficient, and
strength-degree correlation, which agree well with the characterizations of
various real-life networks. Moreover, we show that the introduced Sierpinski
networks are maximal planar graphs.


title: Exact analytical solution of average path length for Apollonian networks

abstract:
  The exact formula for the average path length of Apollonian networks is
found. With the help of recursion relations derived from the self-similar
structure, we obtain the exact solution of average path length, $\bar{d}_t$,
for Apollonian networks. In contrast to the well-known numerical result
$\bar{d}_t \propto (\ln N_t)^{3/4}$ [Phys. Rev. Lett. \textbf{94}, 018702
(2005)], our rigorous solution shows that the average path length grows
logarithmically as $\bar{d}_t \propto \ln N_t$ in the infinite limit of network
size $N_t$. The extensive numerical calculations completely agree with our
closed-form solution.


title: Multipole State of Heavy Lanthanide Filled Skutterudites

abstract:
  We discuss multipole properties of filled skutterudites containing heavy
lanthanide Ln from a microscopic viewpoint on the basis of a seven-orbital
Anderson model. For Ln=Gd, in contrast to naive expectation, quadrupole moments
remain in addition to main dipole ones. For Ln=Ho, we find an exotic state
governed by octupole moment. For Ln=Tb and Tm, no significant multipole moments
appear at low temperatures, while for Ln=Dy, Er, and Yb, dipole and
higher-order multipoles are dominant. We briefly discuss possible relevance of
these multipole states with actual materials.


title:
Gabay-Toulouse Phase Transition in Heisenberg Spin-Glasses in Three
  Dimensions

abstract:
  We examine three-dimensional $\pm J$ Heisenberg models with and without
random anisotropies in a magnetic field. We calculate both the stiffness
exponent $\theta_s$ at absolute zero temperature and spin-glass correlation
lengths for the longitudinal and transverse spin components at finite
temperatures. We suggest that, contrary to a chirality scenario predicted by
Kawamura and his co-workers, a Gabay-Toulouse phase transition occurs when the
anisotropies are absent, although no phase transition occurs when they are
present.