title:
A Novel phase in the phase structure of the $(g\phi^4 + h\phi^6)_{1+1}$
  field theoretic model

abstract:
  In view of the newly discovered and physically acceptable $PT$ symmetric and
non-Hermitian models, we reinvestigated the phase structure of the
($g\phi^{4}+h\phi^{6}$)$_{1+1}$ Hermitian model. The reinvestigation concerns
the possibility of a phase transition from the original Hermitian and $PT$
symmetric phase to a non-Hermitian and $PT$ symmetric one. This kind of phase
transition, if verified experimentally, will lead to the first proof that
non-Hermitian and $PT$ symmetric models are not just a mathematical research
framework but are a nature desire. To do the investigation, we calculated the
effective potential up to second order in the couplings and found a Hermitian
to Non-Hermitian phase transition. This leads us to introduce, for the first
time, hermiticity as a symmetry which can be broken due to quantum corrections,
\textit{i.e.}, when starting with a model which is Hermitian in the classical
level, quantum corrections can break hermiticity while the theory stays
physically acceptable. In fact, ignoring this phase will lead to violation of
universality when comparing this model predictions with other models in the
same class of universality. For instance, in a previous work we obtained a
second order phase transition for the $PT$ symmetric and non-Hermitian
$(-g\phi^{4})$ and according to universality, this phase should exist in the
phase structure of the ($g\phi^{4}+h\phi^{6}$) model for negative $g$. Finally,
among the novelties in this letter, in our calculation for the effective
potential, we introduced a new renormalization group equation which describes
the invariance of the bare vacuum energy under the change of the scale. We
showed that without this invariance, the original theory and the effective one
are inequivalent.


title: Long-Distance Entanglement Distribution with Single-Photon Sources

abstract:
  We present an efficient architecture for quantum repeaters based on
single-photon sources in combination with quantum memories for photons. Errors
inherent to previous repeater protocols using photon-pair sources are
eliminated, leading to a significant gain in efficiency. We establish the
requirements on the single-photon sources and on the photon detectors.


title: Hamiltonian Theory of Adiabatic Motion of Relativistic Charged Particles

abstract:
  A general Hamiltonian theory for the adiabatic motion of relativistic charged
particles confined by slowly-varying background electromagnetic fields is
presented based on a unified Lie-transform perturbation analysis in extended
phase space (which includes energy and time as independent coordinates) for all
three adiabatic invariants. First, the guiding-center equations of motion for a
relativistic particle are derived from the particle Lagrangian. Covariant
aspects of the resulting relativistic guiding-center equations of motion are
discussed and contrasted with previous works. Next, the second and third
invariants for the bounce motion and drift motion, respectively, are obtained
by successively removing the bounce phase and the drift phase from the
guiding-center Lagrangian. First-order corrections to the second and third
adiabatic invariants for a relativistic particle are derived. These results
simplify and generalize previous works to all three adiabatic motions of
relativistic magnetically-trapped particles.


title: Towards understanding and modelling office daily life

abstract:
  Measuring and modeling human behavior is a very complex task. In this paper
we present our initial thoughts on modeling and automatic recognition of some
human activities in an office. We argue that to successfully model human
activities, we need to consider both individual behavior and group dynamics. To
demonstrate these theoretical approaches, we introduce an experimental system
for analyzing everyday activity in our office.


title: The Heegaard structure of Dehn filled manifolds

abstract:
  We expect manifolds obtained by Dehn filling to inherit properties from the
knot manifold. To what extent does that hold true for the Heegaard structure?
We study four changes to the Heegaard structure that may occur after filling:
(1) Heegaard genus decreases, (2) a new Heegaard surface is created, (3) a
non-stabilized Heegaard surface destabilizes, and (4) two or more non-isotopic
Heegaard surfaces become isotopic. We survey general results that give quite
satisfactory restrictions to phenomena (1) and (2) and, in a parallel thread,
give a complete classification of when all four phenomena occur when filling
most torus knot exteriors. This latter thread yields sufficient (and perhaps
necessary) conditions for the occurrence of phenomena (3) and (4).


title:
Generalized Continuous-Time Random Walks (CTRW), Subordination by
  Hitting Times and Fractional Dynamics

abstract:
  Functional limit theorem for continuous-time random walks (CTRW) are found in
general case of dependent waiting times and jump sizes that are also position
dependent. The limiting anomalous diffusion is described in terms of fractional
dynamics. Probabilistic interpretation of generalized fractional evolution is
given in terms of the random time change (subordination) by means of hitting
times processes.


title: Proof of Riemann Hypothesis

abstract:
  In this article, we will prove Riemann Hypothesis by using the mean value
theorem of integrals. The function $ \xi(s) $ is introduced by Riemann, which
zeros are identical equal to non-trivial zeros of zeta function.The function $
\xi(s) $ is an entire function, and its real part and imaginary part can be
represented as infinite integral form. In the special condition, the mean value
theorem of integrals is established for infinite integral. Using the mean value
theorem of integrals and the isolation of zeros of analytic function, we
determined that all zeros of the function $ \xi(s) $ have real part equal
to$\frac{1}{2}$, namely, all non-trivial zeros of zeta function lies on the
critical line. Riemann Hypothesis is true.


title: LARES/WEBER-SAT and the equivalence principle

abstract:
  It has often been claimed that the proposed Earth artificial satellite
LARES/WEBER-SAT-whose primary goal is, in fact, the measurement of the general
relativistic Lense-Thirring effect at a some percent level-would allow to
greatly improve, among (many) other things, the present-day (10^-13) level of
accuracy in testing the equivalence principle as well. Recent claims point
towards even two orders of magnitude better, i.e. 10^-15. In this note we show
that such a goal is, in fact, unattainable by many orders of magnitude being,
instead, the achievable level of the order of 10^-9.


title:
Systematic corrections to the measured cosmological constant as a result
  of local inhomogeneity

abstract:
  We calculate the systematic inhomogeneity-induced correction to the
cosmological constant that one would infer from an analysis of the luminosities
and redshifts of Type Ia supernovae, assuming a homogeneous universe. The
calculation entails a post-Newtonian expansion within the framework of second
order perturbation theory, wherein we consider the effects of subhorizon
density perturbations in a flat, dust dominated universe. Within this
formalism, we calculate luminosity distances and redshifts along the past light
cone of an observer. The resulting luminosity distance-redshift relation is fit
to that of a homogeneous model in order to deduce the best-fit cosmological
constant density Omega_Lambda. We find that the luminosity distance-redshift
relation is indeed modified, by a small fraction of order 10^{-5}. When fitting
this perturbed relation to that of a homogeneous universe, we find that the
inferred cosmological constant can be surprisingly large, depending on the
range of redshifts sampled. For a sample of supernovae extending from z=0.02
out to z=0.15, we find that Omega_Lambda=0.004. The value of Omega_Lambda has a
large variance, and its magnitude tends to get larger for smaller redshifts,
implying that precision measurements from nearby supernova data will require
taking this effect into account. However, we find that this effect is likely
too small to explain the observed value of Omega_Lambda=0.7. There have been
previous claims of much larger backreaction effects. By contrast to those
calculations, our work is directly related to how observers deduce cosmological
parameters from astronomical data.


title: Probabilistic purification of noisy coherent states

abstract:
  A basic feasible probabilistic purification of unknown noisy coherent states,
outgoing from different state preparations with unknown mean number of thermal
photons, is proposed. The scheme is based only on a linear-optical network with
an avalanche photo-diode or heterodyne (homodyne) detection used to post-select
a successful processing. The suggested probabilistic method can produce an
output state with a lower noise than both quantum deterministic and classical
probabilistic distillation method. The purification applied in the state
preparation can increase classical capacity of communication and security of
quantum key distribution.


title:
Nonlocal explanation of stationary and nonstationary regimes in cascaded
  soliton pulse compression

abstract:
  We study soliton pulse compression in materials with cascaded quadratic
nonlinearities, and show that the group-velocity mismatch creates two different
temporally nonlocal regimes. They correspond to what is known as the stationary
and nonstationary regimes. The theory accurately predicts the transition to the
stationary regime, where highly efficient pulse compression is possible.


title: Low Mass Dimuons Produced in Relativistic Nuclear Collisions

abstract:
  The NA60 experiment has measured low-mass muon pair production in In-In
collisions at 158 A GeV with unprecedented precision. We show that this data is
reproduced very well by a dynamical model with parameters scaled from fits to
measurements of hadronic transverse mass spectra and Hanbury-Brown and Twiss
correlations in Pb-Pb and Pb-Au collisions at the same energy. The data is
consistent with in-medium properties of $\rho$ and $\omega$-mesons at finite
temperature and density as deduced from empirical forward-scattering
amplitudes. Inclusion of the vacuum decay of the $\rho$-meson after freeze-out
is necessary for an understanding of the mass and transverse momentum spectrum
of dimuons with $M \apprle 0.9 {\rm GeV}/c^2$.


title: Toward Forecasting Volcanic Eruptions using Seismic Noise

abstract:
  During inter-eruption periods, magma pressurization yields subtle changes of
the elastic properties of volcanic edifices. We use the reproducibility
properties of the ambient seismic noise recorded on the Piton de la Fournaise
volcano to measure relative seismic velocity variations of less than 0.1 % with
a temporal resolution of one day. Our results show that five studied volcanic
eruptions were preceded by clearly detectable seismic velocity decreases within
the zone of magma injection. These precursors reflect the edifice dilatation
induced by magma pressurization and can be useful indicators to improve the
forecasting of volcanic eruptions.


title:
The characterization of the Carleson measures for analytic Besov spaces:
  a simple proof

abstract:
  We give a simple proof of the characterization of the Carleson measures for
the weighted analytic Besov spaces. Such characterization provides some
information on the radial variation of an analytic Besov function.


title:
Secondary invariants for Frechet algebras, quasihomomorphisms, and the
  residue Chern character

abstract: This paper has been replaced by arXiv:0804.1042 and arXiv:0804.1048


title: Comments on the Quantum Afterburner

abstract:
  A process has been proposed to increase the efficiency of an ideal Otto cycle
via a quantum heat engine that has no cooler reservoir. We show that such a
process is not feasible.


title: 3-He in the Milky Way Interstellar Medium: Ionization Structure

abstract:
  The cosmic abundance of the 3-He isotope has important implications for many
fields of astrophysics. We are using the 8.665 GHz hyperfine transition of
3-He+ to determine the 3-He/H abundance in Milky Way HII regions and planetary
nebulae. This is one in a series of papers in which we discuss issues involved
in deriving accurate 3-He/H abundance ratios from the available measurements.
Here we describe the ionization correction we use to convert the 3-He+/H+
abundance, y3+, to the 3-He/H abundance, y3. In principle the nebular
ionization structure can significantly influence the y3 derived for individual
sources. We find that in general there is insufficient information available to
make a detailed ionization correction. Here we make a simple correction and
assess its validity. The correction is based on radio recombination line
measurements of H+ and 4-He+, together with simple core-halo source models. We
use these models to establish criteria that allow us to identify sources that
can be accurately corrected for ionization and those that cannot. We argue that
this effect cannot be very large for most of the sources in our observational
sample. For a wide range of models of nebular ionization structure we find that
the ionization correction factor varies from 1 to 1.8. Although large
corrections are possible, there would have to be a conspiracy between the
density and ionization structure for us to underestimate the ionization
correction by a substantial amount.


title:
Efficient method for detection of periodic orbits in chaotic maps and
  flows

abstract:
  An algorithm for detecting unstable periodic orbits in chaotic systems [Phys.
Rev. E, 60 (1999), pp. 6172-6175] which combines the set of stabilising
transformations proposed by Schmelcher and Diakonos [Phys. Rev. Lett., 78
(1997), pp. 4733-4736] with a modified semi-implicit Euler iterative scheme and
seeding with periodic orbits of neighbouring periods, has been shown to be
highly efficient when applied to low-dimensional system. The difficulty in
applying the algorithm to higher dimensional systems is mainly due to the fact
that the number of stabilising transformations grows extremely fast with
increasing system dimension. In this thesis, we construct stabilising
transformations based on the knowledge of the stability matrices of already
detected periodic orbits (used as seeds). The advantage of our approach is in a
substantial reduction of the number of transformations, which increases the
efficiency of the detection algorithm, especially in the case of
high-dimensional systems. The performance of the new approach is illustrated by
its application to the four-dimensional kicked double rotor map, a
six-dimensional system of three coupled H\'enon maps and to the
Kuramoto-Sivashinsky system in the weakly turbulent regime.


title: Twistor Actions for Self-Dual Supergravities

abstract:
  We give holomorphic Chern-Simons-like action functionals on supertwistor
space for self-dual supergravity theories in four dimensions, dealing with
N=0,...,8 supersymmetries, the cases where different parts of the R-symmetry
are gauged, and with or without a cosmological constant. The gauge group is
formally the group of holomorphic Poisson transformations of supertwistor space
where the form of the Poisson structure determines the amount of R-symmetry
gauged and the value of the cosmological constant. We give a formulation in
terms of a finite deformation of an integrable \dbar-operator on a supertwistor
space, i.e., on regions in CP^{3|8}. For N=0, we also give a formulation that
does not require the choice of a background.


title: On Jordan Derivations of Triangular Algebras

abstract:
  In this short note we prove that every Jordan derivation of triangular
algebras is a derivation.


title: The wreath product of Z with Z has Hilbert compression exponent 2/3

abstract:
  Let G be a finitely generated group, equipped with the word metric d
associated with some finite set of generators. The Hilbert compression exponent
of G is the supremum over all $\alpha\ge 0$ such that there exists a Lipschitz
mapping $f:G\to L_2$ and a constant $c>0$ such that for all $x,y\in G$ we have
$\|f(x)-f(y)\|_2\ge cd(x,y)^\alpha.$ In \cite{AGS06} it was shown that the
Hilbert compression exponent of the wreath product $\Z\bwr \Z $ is at most
$\frac34$, and in \cite{NP07} was proved that this exponent is at least
$\frac23$. Here we show that $\frac23$ is the correct value. Our proof is based
on an application of K. Ball's notion of Markov type.


title:
On the nature of optical nuclei in FR I radio-galaxies from ACS/HST
  imaging polarimetry

abstract:
  We obtained optical imaging polarimetry with the ACS/HRC aboard the HST of
the 9 closest radio-galaxies in the 3C catalogue with an FR I morphology. The
nuclear sources seen in direct HST images in these galaxies are found to be
highly polarized with levels in the range ~2-11 % with a median value of 7 %.
We discuss the different mechanisms that produce polarized emission and
conclude that the only viable interpretation is a synchrotron origin for the
optical nuclei. This idea is strengthened by the analogy with the polarization
properties of BL Lac objects, providing also further support to the FRI/BL Lac
unified model. This confirms previous suggestions that the dominant emission
mechanism in low luminosity radio-loud AGN is related to non-thermal radiation
produced by the base of their jets. In addition to the nuclear polarization
(and to the large scale optical jets), polarization is detected co-spatially
with the dusty circumnuclear disks, likely due to dichroic transmission; the
polarization vectors are tangential to the disks as expected when the magnetic
field responsible for the grains alignment is stretched by differential
rotation. We explored the possibility to detect the polarimetric signature of a
misaligned radiation beam in FR I, expected in our sources in the frame of the
FR I/ BL Lac unification. We did not find this effect in any of the galaxies,
but our the results are not conclusive on whether a misaligned beam is indeed
present in FR I.


title:
Non-circular motion evidences in the circumnuclear region of M100 (NGC
  4321)

abstract:
  We analyse new integral field spectroscopy of the inner region (central 2.5
kpc) of the spiral galaxy NGC 4321 to study the peculiar kinematics of this
region. Fourier analysis of the velocity residuals obtained by subtracting an
axisymmetric rotation model from the $\rm H\alpha$ velocity field, indicates
that the distortions are {\em global} features generated by an $m=2$
perturbation of the gravitational potential which can be explained by the
nuclear bar. This bar has been previously observed in the near-infrared but not
in the optical continuum dominated by star formation. We detect the optical
counterpart of this bar in the 2D distribution of the old stellar population
(inferred from the equivalent width map of the stellar absorption lines). We
apply the Tremaine--Weinberg method to the stellar velocity field to calculate
the pattern speed of the inner bar, obtaining a value of
$\Omega_b$=160$\pm70\rm km s^{-1} kpc^{-1} $. This value is considerably la
rger than the one obtained when a simple bar model is considered. However the
uncertainties in the pattern speed determination prevent us to give support to
alternative scenarios.


title: Origin of matter in the universe

abstract:
  We extend the standard model with two iso-singlet color triplet scalars, one
singlet real scalar and one singlet fermion. The new fields are odd under an
unbroken Z_2 discrete symmetry while the standard model particles are even. The
decays of the singlet real scalar into three standard model quarks (antiquarks)
with three singlet antifermions (fermions), which explicitly violate the baryon
number, will become effective after the electroweak phase transition and then
produce the observed baryon asymmetry in the universe through the loop diagram
involving the exchange of the W gauge boson. The singlet fermion can serve as
the candidate for cold dark matter. In our model, all new particles with masses
below the TeV scale can be detected by the forthcoming collider experiments or
the next generation experiments for neutron-antineutron oscillations.


title: Macroscopic effects in attosecond pulse generation

abstract:
  We examine how the generation and propagation of high-order harmonics in a
partly ionized gas medium affect their strength and synchronization. The
temporal properties of the resulting attosecond pulses generated in long gas
targets can be significantly influenced by macroscopic effects, in particular
by the intensity in the medium and the degree of ionization. Under some
conditions, the use of gas targets longer than the absorption length can lead
to the generation of self-compressed attosecond pulses. We show this effect
experimentally, using long argon-filled gas cells as generating medium.


title:
Electronic spin transport and spin precession in single graphene layers
  at room temperature

abstract:
  The specific band structure of graphene, with its unique valley structure and
Dirac neutrality point separating hole states from electron states has led to
the observation of new electronic transport phenomena such as anomalously
quantized Hall effects, absence of weak localization and the existence of a
minimum conductivity. In addition to dissipative transport also supercurrent
transport has already been observed. It has also been suggested that graphene
might be a promising material for spintronics and related applications, such as
the realization of spin qubits, due to the low intrinsic spin orbit
interaction, as well as the low hyperfine interaction of the electron spins
with the carbon nuclei. As a first step in the direction of graphene
spintronics and spin qubits we report the observation of spin transport, as
well as Larmor spin precession over micrometer long distances using single
graphene layer based field effect transistors. The non-local spin valve
geometry was used, employing four terminal contact geometries with
ferromagnetic cobalt electrodes, which make contact to the graphene sheet
through a thin oxide layer. We observe clear bipolar (changing from positive to
negative sign) spin signals which reflect the magnetization direction of all 4
electrodes, indicating that spin coherence extends underneath all 4 contacts.
No significant changes in the spin signals occur between 4.2K, 77K and room
temperature. From Hanle type spin precession measurements we extract a spin
relaxation length between 1.5 and 2 micron at room temperature, only weakly
dependent on charge density, which is varied from n~0 at the Dirac neutrality
point to n = 3.6 10^16/m^2. The spin polarization of the ferromagnetic contacts
is calculated from the measurements to be around 10%.


title:
Ising spin glass models versus Ising models: an effective mapping at
  high temperature III. Rigorous formulation and detailed proof for general
  graphs

abstract:
  Recently, it has been shown that, when the dimension of a graph turns out to
be infinite dimensional in a broad sense, the upper critical surface and the
corresponding critical behavior of an arbitrary Ising spin glass model defined
over such a graph, can be exactly mapped on the critical surface and behavior
of a non random Ising model. A graph can be infinite dimensional in a strict
sense, like the fully connected graph, or in a broad sense, as happens on a
Bethe lattice and in many random graphs. In this paper, we firstly introduce
our definition of dimensionality which is compared to the standard definition
and readily applied to test the infinite dimensionality of a large class of
graphs which, remarkably enough, includes even graphs where the tree-like
approximation (or, in other words, the Bethe-Peierls approach), in general, may
be wrong. Then, we derive a detailed proof of the mapping for all the graphs
satisfying this condition. As a byproduct, the mapping provides immediately a
very general Nishimori law.


title:
Electron-phonon and electron-electron interactions in organic field
  effect transistors

abstract:
  Recent experiments have demonstrated that the performances of organic FETs
strongly depend on the dielectric properties of the gate insulator. In
particular, it has been shown that the temperature dependence of the mobility
evolves from a metallic-like to an insulating behavior upon increasing the
dielectric constant of the gate material. This phenomenon can be explained in
terms of the formation of small polarons, due to the polar interaction of the
charge carriers with the phonons at the organic/dielectric interface. Building
on this model, the possible consequences of the Coulomb repulsion between the
carriers at high concentrations are analyzed.


title: Wigner crystals of ions as quantum hard drives

abstract:
  Atomic systems in regular lattices are intriguing systems for implementing
ideas in quantum simulation and information processing. Focusing on laser
cooled ions forming Wigner crystals in Penning traps, we find a robust and
simple approach to engineering non-trivial 2-body interactions sufficient for
universal quantum computation. We then consider extensions of our approach to
the fast generation of large cluster states, and a non-local architecture using
an asymmetric entanglement generation procedure between a Penning trap system
and well-established linear Paul trap designs.


title:
Canonical representatives for residue classes of a polynomial ideal and
  orthogonality

abstract:
  The aim of this paper is to unveil an unexpected relationship between the
normal form of a polynomial with respect to a polynomial ideal and the more
geometric concept of orthogonality. We present a new way to calculate the
normal form of a polynomial with respect to a polynomial ideal I in the ring of
multivariate polynomials over a field K, provided the field K is finite and the
ideal I is a vanishing ideal. In order to use the concept of orthogonality, we
introduce a symmetric bilinear form on a vector space over a finite field.


title: Generators of II_1 Factors

abstract:
  In 2005, Shen introduced a new invariant, $\mathcal G(N)$, of a diffuse von
Neumann algebra $N$ with a fixed faithful trace, and he used this invariant to
give a unified approach to showing that large classes of ${\mathrm{II}}_1$
factors $M$ are singly generated. This paper focuses on properties of this
invariant. We relate $\mathcal G(M)$ to the number of self-adjoint generators
of a ${\mathrm{II}}_1$ factor $M$: if $\mathcal G(M)<n/2$, then $M$ is
generated by $n+1$ self-adjoint operators, whereas if $M$ is generated by $n+1$
self-adjoint operators, then $\mathcal G(M)\leq n/2$. The invariant $\mathcal
G(\cdot)$ is well-behaved under amplification, satisfying $\mathcal
G(M_t)=t^{-2}\mathcal G(M)$ for all $t>0$. In particular, if $\mathcal
G(\mathcal L\mathbb F_r)>0$ for any particular $r>1$, then the free group
factors are pairwise non-isomorphic and are not singly generated for
sufficiently large values of $r$. Estimates are given for forming free products
and passing to finite index subfactors and the basic construction. We also
examine a version of the invariant $\mathcal G_{\text{sa}}(M)$ defined only
using self-adjoint operators; this is proved to satisfy $\mathcal
G_{\text{sa}}(M)=2\mathcal G(M)$. Finally we give inequalities relating a
quantity involved in the calculation of $\mathcal G(M)$ to the free-entropy
dimension $\delta_0$ of a collection of generators for $M$.


title: SPM Bulletin 21

abstract:
  Contents: 1. Editor's note; 2. Personal impressions from the SPM07 meeting;
3. Research announcements; 3.1. Coloring ordinals by reals; 3.2. Long Borel
Hierarchies; 3.3. Rothberger's property in finite powers; 3.4. Special subsets
of the reals and tree forcing notions; 3.5. All automorphisms of the Calkin
algebra are inner; 3.6. Continuous selections and sigma-spaces; 3.7. On the
closure of the diagonal of a T1-space; 3.8. Splitting families and Noetherian
type; 3.9. Even more simple cardinal invariants; 3.10. A classification of CO
spaces which are continuous images of compact ordered spaces; 4. Problem of the
Issue


title: Effect of disorder on a Pomeranchuk instability

abstract:
  We study the effect of disorder on the order parameter equation and
transition temperature of a Pomeranchuk-type Fermi-surface instability using
replica mean field theory. We consider the example of a phase transition to a
$d_{x^2 +y^2}$ type Fermi surface distortion, and show that, in the regime
where such a transition is second order, the transition temperature is reduced
by disorder in essentially the same way as that for a d-wave superconductor. We
argue that observing this disorder dependence of metal-to-metal transition
might be a useful indicator of a finite angular momentum Fermi surface
distortion.


title:
Spherical Continuous Wavelet Transforms arising from sections of the
  Lorentz group

abstract:
  We consider the conformal group of the unit sphere $S^{n-1},$ the so-called
proper Lorentz group Spin$^+(1,n),$ for the study of spherical continuous
wavelet transforms (CWT). Our approach is based on the method for construction
of general coherent states associated to square integrable group
representations over homogeneous spaces. The underlying homogeneous space is an
extension to the whole of the group Spin$^+(1,n)$ of the factorization of the
gyrogroup of the unit ball by an appropriate gyro-subgroup. Sections on this
homogeneous space are constituted by rotations of the subgroup Spin$(n)$ and
M\"{o}bius transformations of the type $\phi_a(x)=(x-a)(1+ax)^{-1},$ where $a$
belongs to a given section on a homogeneous space of the unit ball. This
extends in a natural way the work of Antoine and Vandergheynst to anisotropic
conformal dilations.


title:
Level-rank duality of untwisted and twisted D-branes of the so(N)_K WZW
  model

abstract:
  We analyze the level-rank duality of untwisted and epsilon-twisted D-branes
of the so(N)_K WZW model. Untwisted D-branes of so(N)_K are characterized by
integrable tensor and spinor representations of so(N)_K. Level-rank duality
maps untwisted so(N)_K D-branes corresponding to (equivalence classes of)
tensor representations onto those of so(K)_N. The epsilon-twisted D-branes of
so(2n)_2k are characterized by (a subset of) integrable tensor and spinor
representations of so(2n-1)_2k+1. Level-rank duality maps spinor
epsilon-twisted so(2n)_2k D-branes onto those of so(2k)_2n. For both untwisted
and epsilon-twisted D-branes, we prove that the spectrum of an open string
ending on these D-branes is isomorphic to the spectrum of an open string ending
on the level-rank-dual D-branes.


abstract:
  In this note we study Fano threefolds with noncyclic torsion in the divisor
class group. Since they can all be obtained as quotients of Fano threefolds, we
get also all examples that can be obtained as quotients of low codimension
Fanos in the weighted projective space.


title: The Black Hole Mass of Abell 1836-BCG and Abell 3565-BCG

abstract:
  Two brightest cluster galaxies (BCGs), namely Abell 1836-BCG and Abell
3565-BCG, were observed with the Advanced Camera for Surveys (ACS) and the
Space Telescope Imaging Spectrograph (STIS) on board the Hubble Space
Telescope. By modeling the available photometric and kinematic data, it
resulted that the mass of Abell 1836-BCG and Abell 3565-BCG are
M_bh=4.8(+0.8,-0.7)x10^9 M_sun and M_bh=1.3(+0.3,-0.4)x10^9 M_sun at 1 sigma
confidence level, respectively.


title: Compressibility and equation of state of finite nuclei

abstract:
  We present a new approach for calculating the nuclear equation of state and
compressibility for finite nuclei using the density-constrained Hartree-Fock
method.


title: Kleinian groups with ubiquitous surface subgroups

abstract:
  We show that every finitely-generated free subgroup of a right-angled,
co-compact Kleinian reflection group is contained in a surface subgroup.


title:
Dynamical and Observational Constraints on Additional Planets in Highly
  Eccentric Planetary Systems

abstract:
  Long time coverage and high radial velocity precision have allowed for the
discovery of additional objects in known planetary systems. Many of the
extrasolar planets detected have highly eccentric orbits, which raises the
question of how likely those systems are to host additional planets. We
investigate six systems which contain a very eccentric (e>0.6) planet: HD 3651,
HD 37605, HD 45350, HD 80606, HD 89744, and 16 Cyg B. We present updated
radial-velocity observations and orbital solutions, search for additional
planets, and perform test particle simulations to find regions of dynamical
stability. The dynamical simulations show that short-period planets could exist
in the HD 45350 and 16 Cyg B systems, and we use the observational data to set
tight detection limits, which rule out additional planets down to a few Neptune
masses in the HD 3651, HD 45350, and 16 Cyg B systems.


title:
Galaxy Cluster Gas Mass Fraction and Hubble Parameter versus Redshift
  Constraints on Dark Energy

abstract:
  Galaxy cluster gas mass fraction versus redshift data and Hubble parameter
versus redshift data are used to jointly constrain dark energy models. These
constraints favor the Einstein cosmological constant limit of dark energy but
do not strongly rule out slowly-evolving dark energy.


title: Testing Radiative Neutrino Mass Generation at the LHC

abstract:
  We have investigated in detail a model that contains an additional SU(2)
singlet and triplet scalar fields than the Standard Model (SM). This allows the
radiative generation of Majorana neutrino masses at two-loop order with the
help of doubly charged Higgs bosons that arise from the extended Higgs sector.
We studied in detail the phenomenology of the Higgs and neutrino sectors of the
model. We give the analytical form of the masses of scalar and pseudoscalar
bosons and their mixings, and the structure of the active neutrino mass matrix.
It is found that the model accommodates only normal neutrino mass hierarchy,
and that there is a large parameter space where the doubly charged Higgs can be
observed at the LHC, thereby making it testable at the LHC. Furthermore, the
neutrino-less double beta ($\nonu$) decays arise predominantly from exchange
processes involving the doubly charged Higgs, whose existence is thus
unmistakable if $\nonu$ decays are observed. The production and decays of the
doubly charged Higgs are analyzed, and distinct and distinguishing signals are
discussed.


title: SDSS J080531.84+481233.0: An Unresolved L Dwarf/T Dwarf Binary

abstract:
  SDSS J080531.84+481233.0 is a peculiar L-type dwarf that exhibits unusually
blue near-infrared and mid-infrared colors and divergent optical (L4) and
near-infrared (L9.5) spectral classifications. These peculiar spectral traits
have been variously attributed to condensate cloud effects or subsolar
metallicity. Here I present an improved near-infrared spectrum of this source
which further demonstrates the presence of weak CH4 absorption at 1.6 micron
but no corresponding band at 2.2 micron. It is shown that these features can be
collectively reproduced by the combined light spectrum of a binary with L4.5
and T5 components, as deduced by spectral template matching. Thus, SDSS
J080531.84+481233.0 appears to be a new low-mass binary straddling the L
dwarf/T dwarf transition, an evolutionary phase for brown dwarfs that remains
poorly understood by current theoretical models. The case of SDSS
J080531.84+481233.0 further illustrates how a select range of L dwarf/T dwarf
binaries could be identified and characterized without the need for high
angular resolution imaging or radial velocity monitoring, potentially
alleviating some of the detection biases and limitations inherent to such
techniques.


title:
On the lack of relation between physics and "Quantum discord and
  Maxwell's demons"

abstract:
  The information-theoretic arguments presented in a recent publication on
"Quantum discord and Maxwell's demons" are discussed, and found not to address
the problem specified by Maxwell. Two interrelated and definitive exorcisms of
the demon, one purely thermodynamic, and the other quantum-thermodynamic are
briefly discussed. For each of the two exorcisms, the demon is shown to be
incapable to accomplish his assignment neither because of limitations arising
from information-theoretic tools at his disposal, nor because of the value of
his IQ. The limitations are due to the physics of the state of the system on
which he is asked to perform his demonic acts.


title:
Chemical evolution of the Small Magellanic Cloud based on planetary
  nebulae

abstract:
  We investigate the chemical evolution of the Small Magellanic Cloud (SMC)
based on abundance data of planetary nebulae (PNe). The main goal is to
investigate the time evolution of the oxygen abundance in this galaxy by
deriving an age-metallicity relation. Such a relation is of fundamental
importance as an observational constraint of chemical evolution models of the
SMC. We have used high quality PNe data in order to derive the properties of
the progenitor stars, so that the stellar ages could be estimated. We collected
a large number of measured spectral fluxes for each nebula, and derived
accurate physical parameters and nebular abundances. New spectral data for a
sample of SMC PNe obtained between 1999 and 2002 are also presented. These data
are used together with data available in the literature to improve the accuracy
of the fluxes for each spectral line. We obtained accurate chemical abundances
for PNe in the Small Magellanic Cloud, which can be useful as tools in the
study of the chemical evolution of this galaxy and of Local Group galaxies. We
present the resulting oxygen versus age diagram and a similar relation
involving the [Fe/H] metallicity based on a correlation with stellar data. We
discuss the implications of the derived age-metallicity relation for the SMC
formation, in particular by suggesting a star formation burst in the last 2-3
Gyr.


title:
The Riemann hypothesis - an elementary analytic approach based on
  complex Laplace transform

abstract:
  An elementary analytic proof of the famous Riemann hypothesis is given. The
main "accent" of the proof is a both using of the 2-dimensional double real and
complex Laplace integral representations of the Green function $\mid z
\mid^{-2}$.


title:
Formation of singularities for a transport equation with nonlocal
  velocity

abstract:
  We study a 1D transport equation with nonlocal velocity and show the
formation of singularities in finite time for a generic family of initial data.
By adding a diffusion term the finite time singularity is prevented and the
solutions exist globally in time.


title:
Energy Density-Flux Correlations in an Unusual Quantum State and in the
  Vacuum

abstract:
  In this paper we consider the question of the degree to which negative and
positive energy are intertwined. We examine in more detail a previously studied
quantum state of the massless minimally coupled scalar field, which we call a
``Helfer state''. This is a state in which the energy density can be made
arbitrarily negative over an arbitrarily large region of space, but only at one
instant in time. In the Helfer state, the negative energy density is
accompanied by rapidly time-varying energy fluxes. It is the latter feature
which allows the quantum inequalities, bounds which restrict the magnitude and
duration of negative energy, to hold for this class of states. An observer who
initially passes through the negative energy region will quickly encounter
fluxes of positive energy which subsequently enter the region. We examine in
detail the correlation between the energy density and flux in the Helfer state
in terms of their expectation values. We then study the correlation function
between energy density and flux in the Minkowski vacuum state, for a massless
minimally coupled scalar field in both two and four dimensions. In this latter
analysis we examine correlation functions rather than expectation values.
Remarkably, we see qualitatively similar behavior to that in the Helfer state.
More specifically, an initial negative energy vacuum fluctuation in some region
of space is correlated with a subsequent flux fluctuation of positive energy
into the region. We speculate that the mechanism which ensures that the quantum
inequalities hold in the Helfer state, as well as in other quantum states
associated with negative energy, is, at least in some sense, already
``encoded'' in the fluctuations of the vacuum.


title:
Low-lying Wilson Dirac operator eigenvector mixing in dynamical overlap
  Hybrid Monte-Carlo

abstract:
  Current dynamical overlap fermion hybrid Monte Carlo simulations encounter
large fermionic forces when there is mixing between near zero-eigenvectors of
the kernel operator. This leads to low acceptance rates when there is a large
density of near zero eigenvectors. I present a method where these large forces
are eliminated and the large action jumps seen when two eigenvectors approach
zero are significantly reduced. This significantly increases the stability of
the algorithm, and allows the use of larger integration time steps.


title: Excitonic Mott transition in type-II quantum dots

abstract:
  Photoluminescence spectra measured on a type-II GaSb/GaAs quantum dot
ensemble at high excitation power indicate a Mott transition from the low
density state comprising of spatially-indirect excitons to a high density
electron-plasma state. Under the influence of a very high magnetic field, the
electron-plasma that is formed at high excitation powers is `frozen-out' into a
state of optically inactive magneto-excitons.


title: Skew-Hadamard matrices of orders 436, 580 and 988 exist

abstract:
  We construct two difference families on each of the cyclic groups of order
109, 145 and 247, and use them to construct skew-Hadamard matrices of orders
436, 580 and 988. Such difference families and matrices are constructed here
for the first time. The matrices are constructed by using the Goethals-Seidel
array.


title:
Towards a microscopic theory of toroidal moments in bulk periodic
  crystals

abstract:
  We present a theoretical analysis of magnetic toroidal moments in periodic
systems, in the limit in which the toroidal moments are caused by a time and
space reversal symmetry breaking arrangement of localized magnetic dipole
moments. We summarize the basic definitions for finite systems and address the
question of how to generalize these definitions to the bulk periodic case. We
define the toroidization as the toroidal moment per unit cell volume, and we
show that periodic boundary conditions lead to a multivaluedness of the
toroidization, which suggests that only differences in toroidization are
meaningful observable quantities. Our analysis bears strong analogy to the
modern theory of electric polarization in bulk periodic systems, but we also
point out some important differences between the two cases. We then discuss the
instructive example of a one-dimensional chain of magnetic moments, and we show
how to properly calculate changes of the toroidization for this system.
Finally, we evaluate and discuss the toroidization (in the local dipole limit)
of four important example materials: BaNiF_4, LiCoPO_4, GaFeO_3, and BiFeO_3.


title: Proper Motions in the Galactic Bulge: Plaut's Window

abstract:
  A proper motion study of a field of 20' x 20' inside Plaut's low extinction
window (l,b)=(0 deg,-8 deg), has been completed. Relative proper motions and
photographic BV photometry have been derived for ~21,000 stars reaching to
V~20.5 mag, based on the astrometric reduction of 43 photographic plates,
spanning over 21 years of epoch difference. Proper motion errors are typically
1 mas/yr and field dependent systematics are below 0.2 mas/yr.
Cross-referencing with the 2MASS catalog yielded a sample of ~8,700 stars, from
which predominantly disk and bulge subsamples were selected photometrically
from the JH color-magnitude diagram. The two samples exhibited different
proper-motion distributions, with the disk displaying the expected reflex solar
motion as a function of magnitude. Galactic rotation was also detected for
stars between ~2 and ~3 kpc from us. The bulge sample, represented by red
giants, has an intrinsic proper motion dispersion of (sigma_l,sigma_b)=(3.39,
2.91)+/-(0.11,0.09) mas/yr, which is in good agreement with previous results,
and indicates a velocity anisotropy consistent with either rotational
broadening or tri-axiality. A mean distance of 6.37^{+0.87}_{-0.77} kpc has
been estimated for the bulge sample, based on the observed K magnitude of the
horizontal branch red clump. The metallicity [M/H] distribution was also
obtained for a subsample of 60 bulge giants stars, based on calibrated
photometric indices. The observed [M/H] shows a peak value at [M/H]~-0.1 with
an extended metal poor tail and around 30% of the stars with supersolar
metallicity. No change in proper motion dispersion was observed as a function
of [M/H]. We are currently in the process of obtaining CCD UBVRI photometry for
the entire proper-motion sample of ~21,000 stars.


title: Tidal dwarf galaxies as a test of fundamental physics

abstract:
  Within the cold dark matter (CDM) framework tidal dwarf galaxies (TDGs)
cannot contain dark matter, so the recent results by Bournaud et al. (2007)
that 3 rotating TDGs do show significant evidence for being dark matter
dominated is inconsistent with the current concordance cosmological theory
unless yet another dark matter component is postulated. We confirm that the TDG
rotation curves are consistent with Newtonian dynamics only if either an
additional dark matter component is postulated, or if all 3 TDGs happen to be
viewed nearly edge-on, which is unlikely given the geometry of the tidal
debris. We also find that the observed rotation curves are very naturally
explained without any free parameters within the modified Newtonian dynamics
(MOND) framework if inclinations are adopted as derived by Bournaud et al. We
explore different inclination angles and two different assumptions about the
external field effect. The results do not change significantly, and we conclude
therefore that Newtonian dynamics has severe problems while MOND does
exceedingly well in explaining the observed rotation curves of the 3 TDGs
studied by Bournaud et al.


title: Challenging the Cosmological Constant

abstract:
  We outline a dynamical dark energy scenario whose signatures may be
simultaneously tested by astronomical observations and laboratory experiments.
The dark energy is a field with slightly sub-gravitational couplings to matter,
a logarithmic self-interaction potential with a scale tuned to $\sim 10^{-3}
{\rm eV}$, as is usual in quintessence models, and an effective mass $m_\phi$
influenced by the environmental energy density. Its forces may be suppressed
just below the current bounds by the chameleon-like mimicry, whereby only outer
layers of mass distributions, of thickness $1/m_\phi$, give off appreciable
long range forces. After inflation and reheating, the field is relativistic,
and attains a Planckian expectation value before Hubble friction freezes it.
This can make gravity in space slightly stronger than on Earth. During the
matter era, interactions with nonrelativistic matter dig a minimum close to the
Planck scale. However, due to its sub-gravitational matter couplings the field
will linger away from this minimum until the matter energy density dips below
$\sim 10^{-12} {\rm eV}^4$. Then it starts to roll to the minimum, driving a
period of cosmic acceleration. Among the signatures of this scenario may be
dark energy equation of state $w \ne -1$, stronger gravity in dilute mediums,
that may influence BBN and appear as an excess of dark matter, and
sub-millimeter corrections to Newton's law, close to the present laboratory
limits.


title: On the Stopping Time of a Bouncing Ball

abstract:
  We study a simple model of a bouncing ball that takes explicitely into
account the elastic deformability of the body and the energy dissipation due to
internal friction. We show that this model is not subject to the problem of
inelastic collapse, that is, it does not allow an infinite number of impacts in
a finite time. We compute asymptotic expressions for the time of flight and for
the impact velocity. We also prove that contacts with zero velocity of the
lower end of the ball are possible, but non-generic. Finally, we compare our
findings with other models and laboratory experiments.


title: Black hole radiation spectrum in LQG: Isolated Horizon framework

abstract:
  Recent detailed analysis within the Loop Quantum Gravity calculation of black
hole entropy shows a stair-like structure in the behavior of entropy as a
function of horizon area. The non-trivial distribution of the degeneracy of the
black hole horizon area eigenstates is at the origin of this behavior. This
degeneracy distribution is analyzed and a phenomenological model is put forward
to study the implications of this distribution in the black hole radiation
spectrum. Some qualitative quantum effects are obtained within the isolated
horizon framework. This result provides us with a possible observational test
of this model for quantum black holes.


title: Bubbles in the Self-Accelerating Universe

abstract:
  We revisit the issue of the stability in the Dvali-Gabadadze-Porrati model,
by considering the nucleation of bubbles of the conventional branch within the
self-accelerating branch. We construct an instanton describing this process in
the thin wall approximation. On one side of the bubble wall, the bulk consists
of the exterior of the brane while on the other side it is the interior. The
solution requires the presence of a 2-brane (the bubble wall) which induces the
transition. However, we show that this instanton cannot be realized as the thin
wall limit of any smooth solution. Once the bubble thickness is resolved, the
equations of motion do not allow O(4) symmetric solutions joining the two
branches. We conclude that the thin wall instanton is unphysical, and that one
cannot have processes connecting the two branches, unless negative tension
bubble walls are introduced. This also suggests that the self-accelerating
branch does not decay into the conventional branch nucleating bubbles. We
comment on other kinds of bubbles that could interpolate between the two
branches.


title: Equilibrium configurations of two charged masses in General Relativity

abstract:
  An asymptotically flat static solution of Einstein-Maxwell equations which
describes the field of two non-extreme Reissner - Nordstr\"om sources in
equilibrium is presented. It is expressed in terms of physical parameters of
the sources (their masses, charges and separating distance). Very simple
analytical forms were found for the solution as well as for the equilibrium
condition which guarantees the absence of any struts on the symmetry axis. This
condition shows that the equilibrium is not possible for two black holes or for
two naked singularities. However, in the case when one of the sources is a
black hole and another one is a naked singularity, the equilibrium is possible
at some distance separating the sources. It is interesting that for
appropriately chosen parameters even a Schwarzschild black hole together with a
naked singularity can be "suspended" freely in the superposition of their
fields.


title:
Limits on primordial power spectrum resolution: An inflationary flow
  analysis

abstract:
  We investigate the ability of current CMB data to reliably constrain the form
of the primordial power spectrum generated during inflation. We attempt to
identify more exotic power spectra that yield equally good fits to the data as
simple power-law spectra. In order to test a wide variety of spectral shapes,
we combine the flow formalism, which is a method of stochastic model
generation, with a numerical integration of the mode equations of quantum
fluctuations. This allows us to handle inflation models that yield spectra that
are not well described by the standard spectral parameterization. Using the
latest WMAP data-set, we find a high degree of variation in possible spectral
shapes. In particular, we find strongly running spectra arising from
fast-rolling inflaton fields providing equally good fits to the data as
power-law spectra arising from slowly-rolling fields. Current data poorly
constrains the spectrum on scales (k < 0.01 h{\rm Mpc}^{-1}), where the error
due to cosmic variance is large. Among the statistically degenerate models, we
identify spectra with strong running on these larger scales, but with reduced
running at smaller scales. These models predict values for the tensor-to-scalar
ratio, (r), that lie outside the 2-(\sigma) confidence interval obtained from
SDSS+WMAP data for spectra that are parametrized as power-laws or spectra with
constant running. By considering more generalized power spectra, we therefore
open up regions of parameter space excluded for simpler models.


title: The Heavy Ion Physics Program with ATLAS at the LHC

abstract:
  The first Pb+Pb collisions at the Large Hadron Collider (LHC) at sqrts_NN =
5.52 TeV are imminent. Heavy ion collisions at the LHC provide an extended
energy lever arm to the existing measurements made at RHIC and SPS, especially
in hard (large-Q^2) processes. In this contribution an overview of the ATLAS
detector is given and the current physics focus of Heavy Ion Working Group is
discussed.


title: Measurements of Top Properties at the Tevatron

abstract:
  The large data samples of thousands of top events collected at the Tevatron
experiments CDF and D0 allow for a variety of measurements to analyze the
properties of the top quark. Guided by the question "Is the top quark observed
at the Tevatron really the top quark of the standard model,'' we present
Tevatron analyses studying the top production mechanism including resonant
$t\bar{t}$ production, the V-A structure of the $t\to Wb$ decay vertex, the
charge of the top quark, and single-top production via flavor-changing neutral
currents.


title: Examining the Location of the Magnetopause in an Undergraduate Lab

abstract:
  Integrating areas of current research into undergraduate physics labs can be
a difficult task. The location of the magnetopause is one problem that can be
examined with no prior exposure to space physics. The magnetopause location can
be viewed as a pressure balance between the dynamic pressure of the solar wind
and the magnetic pressure of the magnetosphere. In this lab sophomore and
junior students examine the magnetopause location using simulation results from
BATS-R-US global MHD code run at NASA's Community Coordinated Modeling Center.
Students also analyze data from several spacecraft to find magnetopause
crossings. The students get reasonable agreement between their results and
model predictions from this lab as well as exposure to the tools and techniques
of space physics.


title:
Electronic band structure and carrier effective mass in calcium
  aluminates

abstract:
  First-principles electronic band structure investigations of five compounds
of the CaO-Al2O3 family, 3CaO.Al2O3, 12CaO.7Al2O3, CaO.Al2O3, CaO.2Al2O3 and
CaO.6Al2O3, as well as CaO and alpha-, theta- and kappa-Al2O3 are performed. We
find that the conduction band in the complex oxides is formed from the oxygen
antibonding p-states and, although the band gap in Al2O3 is almost twice larger
than in CaO, the s-states of both cations. Such a hybrid nature of the
conduction band leads to isotropic electron effective masses which are nearly
the same for all compounds investigated. This insensitivity of the effective
mass to variations in the composition and structure suggests that upon a proper
degenerate doping, both amorphous and crystalline phases of the materials will
possess mobile extra electrons.


title:
Dynamics of the solar chromosphere. V. High-frequency modulation in
  ultraviolet image sequences from TRACE

abstract:
  We search for signatures of high-frequency oscillations in the upper solar
photosphere and low chromosphere in the context of acoustic heating of outer
stellar atmospheres. We use ultraviolet image sequences of a quiet center-disk
area from the Transition Region and Coronal Explorer (TRACE) mission which were
taken with strict cadence regularity. The latter permits more reliable
high-frequency diagnosis than in earlier work. Spatial Fourier power maps,
spatially averaged coherence and phase-difference spectra, and spatio-temporal
k-f decompositions all contain high-frequency features that at first sight seem
of considerable intrinsic interest but actually are more likely to represent
artifacts of different nature. Spatially averaged phase difference measurement
provides the most sensitive diagnostic and indicates the presence of acoustic
modulation up to f=20 mHz (periods down to 50 seconds) in internetwork areas.


title: Lectures on Astronomy, Astrophysics, and Cosmology

abstract:
  This is a written version of a series of lectures aimed at undergraduate
students in astrophysics/particle theory/particle experiment. We summarize the
important progress made in recent years towards understanding high energy
astrophysical processes and we survey the state of the art regarding the
concordance model of cosmology.


title:
Interplay and optimization of decoherence mechanisms in the optical
  control of spin quantum bits implemented on a semiconductor quantum dot

abstract:
  We study the influence of the environment on an optically induced rotation of
a single electron spin in a charged semiconductor quantum dot. We analyze the
decoherence mechanisms resulting from the dynamical lattice response to the
charge evolution induced in a trion-based optical spin control scheme.
Moreover, we study the effect of the finite trion lifetime and of the
imperfections of the unitary evolution such as off-resonant excitations and the
nonadiabaticity of the driving. We calculate the total error of the operation
on a spin-based qubit in an InAs/GaAs quantum dot system and discuss possible
optimization against the different contributions. We indicate the parameters
which allow for coherent control of the spin with a single qubit gate error as
low as $10^{-4}$.


title: Applying Extensive Air Shower Universality to Ground Detector Data

abstract:
  Air shower universality states that the electromagnetic part of
hadron-induced extensive air showers (EAS) can be completely described in terms
of the primary energy and shower age. In addition, simulations show that the
muon part is well characterized by an overall normalization which depends on
the primary particle and hadronic interaction model. We investigate the
consequences of EAS universality for ground arrays, which sample EAS at large
core distances, and show how universality can be used to experimentally
determine the muon content as well as the primary energy of cosmic ray air
showers in a model-independent way.


title:
Antiproliferative MCR peptides block physical interaction of insulin
  with retinoblastoma protein (RB) in human lung cancer cells

abstract:
  Fifteen years ago, a structural analysis of the hormone insulin and the
retinoblastoma tumor suppressor protein (RB) revealed that they may physically
interact with one another. Subsequently, an RB peptide corresponding to the
proposed RB binding site for insulin was found to recognize full-length insulin
in vitro. As part of efforts aimed at developing this RB peptide into an
anti-cancer drug, this molecule was chemically coupled to a cellular
internalization signal and termed "MCR peptide". Meanwhile, several such MCR
peptide variants have been demonstrated to restrain the proliferation of
different human cancer cells in vitro and in vivo. Moreover, one of the MCR
peptides coined MCR-10 was shown to be capable of interfering with the complex
formation between insulin and RB in HepG2 human hepatoma cells, as monitored by
immunofluorescence. This latter result indicating an in vivo association
between insulin and RB was confirmed by a follow-up study combining the methods
of co-immunoprecipitation and immunoblotting. Here, we provide evidence for the
existence of the insulin-RB complex in A549 human non-small cell lung cancer
cells. Specifically, we demonstrate this heterodimer by means of a magnetic
beads-based immunoprecipitation approach and equally show that this dimer can
be disrupted by MCR-4 or MCR-10 each of which is known to possess
antiproliferative properties, yet to a much lesser extent by a control peptide.
Thus, this investigation has yielded another important proof for the occurrence
of the insulin-RB dimer and, furthermore, its validity as a target for
antineoplastic MCR peptides.


title: Masses and decay modes of charmonia using a confinement model

abstract:
  The masses of charmonium s and p-states, pseudoscalar and vector decay
constants, leptonic, hadronic as well as radiative decay widths for charmonia
have been computed in the framework of extended harmonic confinement model
without any additional parameters. The outcome in comparison with other
contemporary theoretical and experimental results is presented.


title:
On pathwise uniqueness for reflecting Brownian motion in $C^{1+\gamma}$
  domains

abstract:
  Pathwise uniqueness holds for the Skorokhod stochastic differential equation
in $C^{1+\gamma}$ domains in $\mathbb{R}^d$ for $\gamma >1/2$ and $d\geq3$.


title: On the Quantum Jarzynski Identity

abstract:
  In this note, we will discuss how to compactly express and prove the
Jarzynski identity for an open quantum system with dissipative dynamics. We
will avoid explicitly measuring the work directly, which is tantamount to
continuously monitoring the system, and instead measure the heat flow from the
environment. We represent the measurement of heat flow with Hermitian map
superoperators that act on the system density matrix. Hermitian maps provide a
convenient and compact representation of sequential measurement and correlation
functions.


title: The Leo Elliptical NGC 3379: A Metal-Poor Halo Emerges

abstract:
  We have used the ACS camera on HST to obtain (V,I) photometry for 5300
red-giant stars in the halo of the dominant Leo-group member NGC 3379, a galaxy
usually regarded as a classic normal giant elliptical. We use this sample of
stars to derive the metallicity distribution function (MDF) for its outer-halo
field stars 33 kpc from the galaxy center. The MDF is distinctly unlike all the
other E galaxies for which we have similar data (including the Local Group
dwarf ellipticals, the intermediate-luminosity NGC 3377, and the giant NGC
5128). First, the MDF for the NGC 3379 outer halo is broad and flat, with many
stars at every interval in [m/H]. Second, we see a metallicity gradient across
our ACS field such that in its outermost region the blue, low-metallicity stars
([m/H] < -0.7) are beginning to dominate and the higher-metallicity stars are
rapidly diminishing. Our target field is centered at a projected distance about
equal to 12 R_e, twice as far out in units of effective radius as in any of the
other galaxies that we have surveyed. If NGC 3379 is indeed representative of
large E/S0 galaxies, we predict that such galaxies in general will reveal
diffuse low-metallicity subpopulations, but that photometry at radii r ~ 10 -
15 R_e will be necessary to see the faint low-metallicity component clearly.


title:
Planet RB: a personal contribution to a proteomic map of human
  retinoblastoma protein

abstract:
  As I compress on the canvas of a few pages here major results of my research
on the retinoblastoma tumor suppressor protein (RB) spreading over the past 15
years, an exciting picture emerges on this unique host molecule which surpasses
in its complexity even that of the most capable viral proteins known to date.
Accordingly, RB has the potential to bind not only growth-promoting proteins
such as insulin, but also to attach itself to calcium and oxygen, as well as to
be secreted into the extracellular environment. Moreover, RB may exert
proteolytic, antimicrobial and anti-aging activities. These condensed
structure-based insights on RB are the substance of a scientific revolution I
have initiated a long time ago, yet likely to gain even further speed in the
years to come, thus expanding both our understanding of life at the molecular
level and the possibilities for pharmacological modulation of fundamental
biological phenomena, particularly in oncology and gerontology.


title: HST Photometry for the Halo Stars in the Leo Elliptical NGC 3377

abstract:
  We have used the ACS camera on HST to obtain (V,I) photometry for 57,000
red-giant stars in the halo of the Leo elliptical NGC 3377. We use this sample
of stars to derive the metallicity distribution function (MDF) for its halo
field stars, and comment on its chemical evolution history compared with both
larger and smaller E galaxies. Our ACS/WFC field spans a radial range extending
from 4 to 18 kpc projected distance from the center of NGC 3377 and thus covers
a significant portion of this galaxy's halo. We find that the MDF is broad,
reaching a peak at [m/H] ~ -0.6$, but containing virtually no stars more
metal-poor than log [m/H] = -1.5$. It may, in addition, have relatively few
stars more metal-rich than [m/H] = -0.3$, although interpretation of the
high-metallicity end of the MDF is limited by photometric completeness that
affects the detection of the reddest, most metal-rich stars. NGC 3377 appears
to have an enrichment history intermediate between those of normal dwarf
ellipticals and the much larger giants. As yet, we find no clear evidence that
the halo of NGC 3377 contains a significant population of ``young'' (< 3 Gy)
stars.


title:
Proposal for a two-channel quantum dot setup: Prediction for the
  capacitance lineshape

abstract:
  We have made a detailed proposal for a two-channel quantum dot setup. The
energy scales in the problem are such that we are able to make connection with
the two-channel Anderson model, which, in spite of being well-known in the
context of heavy-Fermion systems remained theoretically elusive until recently
and lacked a mesoscopic realization. Verification of our precise and robust
predictions for the differential capacitance lineshape of the dot will provide
an experimental signature of the two-channel behavior.


title: Spacetime Indeterminacy and Holographic Noise

abstract:
  A new kind of quantum indeterminacy of transverse position is shown to arise
from quantum degrees of freedom of spacetime, based on the assumption that
classical trajectories can be defined no better than the diffraction limit of
Planck scale waves. Indeterminacy of the angular orientation of particle
trajectories due to wave/particle duality at the Planck scale leads to
indeterminacy of a nearly-flat spacetime metric, described as a small
nonvanishing quantum commutation relation between transverse position operators
at different events along a null trajectory. An independent derivation of the
same effect is presented based on the requirement of unitarity in black hole
evaporation. The indeterminacy is interpreted as a universal holographic
quantum spacetime noise, with a frequency-independent spectrum of metric
perturbation amplitude, h_H^2^{1/2} \simeq \sqrt{l_P}=2.3 \times 10^{-22}
/\sqrt{Hz}, where l_P denotes the Planck length. The effect is estimated to be
directly measurable using current interferometer technology similar to LIGO and
LISA.


title: General Depolarized Pure States: Identification and Properties

abstract:
  The Schmidt decomposition is an important tool in the study of quantum
systems especially for the quantification of the entanglement of pure states.
However, the Schmidt decomposition is only unique for bipartite pure states,
and some multipartite pure states. Here a generalized Schmidt decomposition is
given for states which are equivalent to depolarized pure states. Experimental
methods for the identification of this class of mixed states are provided and
some examples are discussed which show the utility of this description. A
particularly interesting example provides, for the first time, an
interpretation of the number of negative eigenvalues of the density matrix.


title: Polymers in a vacuum

abstract:
  In a variety of situations, isolated polymer molecules are found in a vacuum
and here we examine their properties. Angular momentum conservation is shown to
significantly alter the average size of a chain and its conservation is only
broken slowly by thermal radiation. The time autocorrelation for monomer
position oscillates with a characteristic time proportional to chain length.
The oscillations and damping are analyzed in detail. Short range repulsive
interactions suppress oscillations and speed up relaxation but stretched chains
still show damped oscillatory time correlations.


title: Neutron Transfer Reactions for Deformed Nuclei Using Sturmian Basis

abstract:
  We study the spin-parity distribution P(J$^{\pi}$,E) of $^{156}$Gd excited
states above the neutron separation energy that are expected to be populated
via the neutron pickup reaction $^{157}$Gd($^{3}$He,$^{4}$He)$^{156}$Gd. In
general, modeling of the spin-parity distribution is important for the
applicability of the surrogate reaction technique as a method of deducing
reaction cross sections. We model excited states in $^{156}$Gd as rotational
states built on intrinsic states consisting of a hole in the core where the
hole represents neutron removal form a deformed single particle state. The
reaction cross section to each excited state is calculated using standard
reaction code that uses spherical reaction form-factor input. The spectroscopic
factor associated with each form-factor is the expansion coefficient of the
deformed neutron state in a spherical Sturmian basis consisting of the
spherical reaction form-factors.


title: Numerical Measurements of the Spectrum in Magnetohydrodynamic Turbulence

abstract:
  We report the results of an extensive set of direct numerical simulations of
forced, incompressible, magnetohydrodynamic turbulence with a strong guide
field. The aim is to resolve the controversy regarding the power law exponent
(\alpha, say) of the field perpendicular energy spectrum E(k_\perp) \propto
k_\perp ^ {\alpha}. The two main theoretical predictions, \alpha=-3/2 and
\alpha=-5/3, have both received some support from numerical simulations carried
out by different groups. Our simulations have a resolution of 512^3 mesh
points, a strong guide field, an anisotropic simulation domain, and implement a
broad range of large-scale forcing routines, including those previously
reported in the literature. Our findings indicate that the spectrum of well
developed, strong incompressible MHD turbulence with a strong guide field is
E(k_{\perp})\propto k_{\perp}^{-3/2}.

categories: astro-ph nlin.CD physics.flu-dyn physics.plasm-ph


title:
Bifurcations and chaos in semiconductor superlattices with a tilted
  magnetic field

abstract:
  We study the effects of dissipation on electron transport in a semiconductor
superlattice with an applied bias voltage and a magnetic field that is tilted
relative to the superlattice axis.In previous work, we showed that although the
applied fields are stationary,they act like a THz plane wave, which strongly
couples the Bloch and cyclotron motion of electrons within the lowest miniband.
As a consequence,the electrons exhibit a unique type of Hamiltonian chaos,
which creates an intricate mesh of conduction channels (a stochastic web) in
phase space, leading to a large resonant increase in the current flow at
critical values of the applied voltage. This phase-space patterning provides a
sensitive mechanism for controlling electrical resistance. In this paper, we
investigate the effects of dissipation on the electron dynamics by modifying
the semiclassical equations of motion to include a linear damping term. We
demonstrate that even in the presence of dissipation,deterministic chaos plays
an important role in the electron transport process. We identify mechanisms for
the onset of chaos and explore the associated sequence of bifurcations in the
electron trajectories. When the Bloch and cyclotron frequencies are
commensurate, complex multistability phenomena occur in the system. In
particular, for fixed values of the control parameters several distinct stable
regimes can coexist, each corresponding to different initial conditions. We
show that this multistability has clear, experimentally-observable, signatures
in the electron transport characteristics.


title: QCD String as Vortex String in Seiberg-Dual Theory

abstract:
  We construct a classical vortex string solution in a Seiberg-dual theory of
N=1 supersymmetric SO(N_c) QCD which flows to a confining phase. We claim that
this vortex string is a QCD string, as previouly argued by M.Strassler. In
SO(N_c) QCD, it is known that stable QCD strings exist even in the presence of
dynamical quarks. We show that our vortex strings are stable in the
Seiberg-dual theory.


title: The Nature of the Far-UV Break in the Energy Distribution of Quasars

abstract:
  A prominent continuum steepening is observed in quasar energy distributions
near 1100A. We review possible interpretations for the physical origin of this
so-called far-UV break.


title:
Reconstruction of metabolic networks from high-throughput metabolite
  profiling data: in silico analysis of red blood cell metabolism

abstract:
  We investigate the ability of algorithms developed for reverse engineering of
transcriptional regulatory networks to reconstruct metabolic networks from
high-throughput metabolite profiling data. For this, we generate synthetic
metabolic profiles for benchmarking purposes based on a well-established model
for red blood cell metabolism. A variety of data sets is generated, accounting
for different properties of real metabolic networks, such as experimental
noise, metabolite correlations, and temporal dynamics. These data sets are made
available online. We apply ARACNE, a mainstream transcriptional networks
reverse engineering algorithm, to these data sets and observe performance
comparable to that obtained in the transcriptional domain, for which the
algorithm was originally designed.


title:
DOT tomography of the solar atmosphere. IV. Magnetic patches in
  internetwork areas

abstract:
  We use G-band and Ca II H image sequences from the Dutch Open Telescope (DOT)
to study magnetic elements that appear as bright points in internetwork parts
of the quiet solar photosphere and chromosphere. We find that many of these
bright points appear recurrently with varying intensity and horizontal motion
within longer-lived magnetic patches. We develop an algorithm for detection of
the patches and find that all patches identified last much longer than the
granulation. The patches outline cell patterns on mesogranular scales,
indicating that magnetic flux tubes are advected by granular flows to
mesogranular boundaries. Statistical analysis of the emergence and
disappearance of the patches points to an average patch lifetime as long as
530+-50 min (about nine hours), which suggests that the magnetic elements
constituting strong internetwork fields are not generated by a local turbulent
dynamo.


title: Satellite Galaxies and Fossil Groups in the Millennium Simulation

abstract:
  We use a semianalytic galaxy catalogue constructed from the Millennium
Simulation to study the satellites of isolated galaxies in the LCDM cosmogony.
This sample (~80,000$ bright primaries, surrounded by ~178,000 satellites)
allows the characterization, with minimal statistical uncertainty, of the
dynamical properties of satellite/primary galaxy systems in a LCDM universe. We
find that, overall, the satellite population traces the dark matter rather
well: its spatial distribution and kinematics may be approximated by an NFW
profile with a mildly anisotropic velocity distribution. Their spatial
distribution is also mildly anisotropic, with a well-defined ``anti-Holmberg''
effect that reflects the misalignment between the major axis and angular
momentum of the host halo. The isolation criteria for our primaries picks not
only galaxies in sparse environments, but also a number of primaries at the
centre of ''fossil'' groups. We find that the abundance and luminosity function
of these unusual systems are in reasonable agreement with the few available
observational constraints. We recover the expected L_{host} \sigma_{sat}^3
relation for LCDM models for truly-isolated primaries. Less strict primary
selection, however, leads to substantial modification of the scaling relation.
Our analysis also highlights a number of difficulties afflicting studies that
rely on blind stacking of satellite systems to constrain the mean halo mass of
the primary galaxies.


title: Information-theoretic security without an honest majority

abstract:
  We present six multiparty protocols with information-theoretic security that
tolerate an arbitrary number of corrupt participants. All protocols assume
pairwise authentic private channels and a broadcast channel (in a single case,
we require a simultaneous broadcast channel). We give protocols for veto, vote,
anonymous bit transmission, collision detection, notification and anonymous
message transmission. Not assuming an honest majority, in most cases, a single
corrupt participant can make the protocol abort. All protocols achieve
functionality never obtained before without the use of either computational
assumptions or of an honest majority.


title: Dynamic fibrils in H-alpha and C IV

abstract:
  Aim: To study the interaction of the solar chromosphere with the transition
region, in particular active-region jets in the transition region and their
relation to chromospheric fibrils. Methods: We carefully align image sequences
taken simultaneously in C IV with the Transition Region and Coronal Explorer
and in H-alpha with the Swedish 1-m Solar Telescope. We examine the temporal
evolution of "dynamic fibrils", i.e., individual short-lived active-region
chromospheric jet-like features in H-alpha. Results: All dynamic fibrils appear
as absorption features in H-alpha that progress from the blue to the red wing
through the line, and often show recurrent behavior. Some of them, but not all,
appear also as bright features in C IV which develop at or just beyond the apex
of the H-alpha darkening. They tend to best resemble the H-alpha fibril at +700
mA half a minute earlier. Conclusions: Dynamic chromospheric fibrils observed
in H-alpha regularly correspond to transition-region jets observed in the
ultraviolet. This correspondence suggests that some plasma associated with
dynamic fibrils is heated to transition-region temperatures.


title:
Spinons and triplons in spatially anisotropic frustrated
  antiferromagnets

abstract:
  The search for elementary excitations with fractional quantum numbers is a
central challenge in modern condensed matter physics. We explore the
possibility in a realistic model for several materials, the spin-1/2 spatially
anisotropic frustrated Heisenberg antiferromagnet in two dimensions. By
restricting the Hilbert space to that expressed by exact eigenstates of the
Heisenberg chain, we derive an effective Schr\"odinger equation valid in the
weak interchain-coupling regime. The dynamical spin correlations from this
approach agree quantitatively with inelastic neutron measurements on the
triangular antiferromagnet Cs_2CuCl_4. The spectral features in such
antiferromagnets can be attributed to two types of excitations: descendents of
one-dimensional spinons of individual chains, and coherently propagating
"triplon" bound states of spinon pairs. We argue that triplons are generic
features of spatially anisotropic frustrated antiferromagnets, and arise
because the bound spinon pair lowers its kinetic energy by propagating between
chains.


title: A transient Markov chain with finitely many cutpoints

abstract:
  We give an example of a transient reversible Markov chain that almost surely
has only a finite number of cutpoints. We explain how this is relevant to a
conjecture of Diaconis and Freedman and a question of Kaimanovich. We also
answer Kaimanovich's question when the Markov chain is a nearest-neighbor
random walk on a tree.


title: Fourier analysis of active-region plage

abstract:
  We study the dynamical interaction of the solar chromosphere with the
transition region in mossy and non-mossy active-region plage. We carefully
align image sequences taken with the Transition Region And Coronal Explorer
(TRACE) in the ultraviolet passbands around 1550, 1600, and 1700 A and the
extreme ultraviolet passbands at 171 and 195 A. We compute Fourier
phase-difference spectra that are spatially averaged separately over mossy and
non-mossy plage to study temporal modulations as a function of temporal
frequency. The 1550 versus 171 A comparison shows zero phase difference in
non-mossy plage. In mossy plage, the phase differences between all UV and EUV
passbands show pronounced upward trends with increasing frequency, which
abruptly changes into zero phase difference beyond 4-6 mHz. The phase
difference between the 171 and 195 A sequences exhibits a shallow dip below 3
mHz and then also turns to zero phase difference beyond this value. We
attribute the various similarities between the UV and EUV diagnostics that are
evident in the phase-difference diagrams to the contribution of the C IV
resonance lines in the 1550 and 1600 A passbands. The strong upward trend at
the lower frequencies indicates the presence of upward-traveling disturbances.
It points to correspondence between the lower chromosphere and the upper
transition region, perhaps by slow-mode magnetosonic disturbances, or by a
connection between chromospheric and coronal heating mechanisms. The transition
from this upward trend to zero phase difference at higher frequencies is due to
the intermittent obscuration by fibrils that occult the foot points of hot
loops, which are bright in the EUV and C IV lines, in oscillatory manner.


title: Infrared Limit of Gluon Amplitudes at Strong Coupling

abstract:
  In this note, we propose that the infrared structure of gluon amplitudes at
strong coupling can be fully extracted from a local consideration near cusps.
This is consistent with field theory and correctly reproduces the infrared
divergences of the four-gluon amplitude at strong coupling calculated recently
by Alday and Maldacena.


title: Observations of Water Masers in the NGC 1333 IRAS 4 Region

abstract:
  The NGC 1333 IRAS 4 region was observed in the 22 GHz H2O maser line with an
angular resolution of about 0.08 arcseconds. Two groups of masers were
detected, one near IRAS 4A and the other near BI. Among the eight maser spots
detected near IRAS 4A, six spots are located close to A2, within 100 AU, and
the maser velocities are also near the systemic velocity of the cloud core.
These masers are probably related with the circumstellar disk. Since there is
no maser spot detected around A1, the star forming process is relatively more
active in A2 than in A1. Four maser spots were detected near IRAS 4BI. Since
most of them are distributed along a straight line in the direction of the
outflow, BI masers are most likely related with the jet or outflow. The
disk-outflow dichotomy of H2O masers is discussed briefly. No maser was
detected near H2O(C), another maser source reported previously.


title: Twisted Alexander polynomial of links in the projective space

abstract:
  We use Reidemeister torsion to study a twisted Alexander polynomial, as
defined by Turaev, for links in the projective space. Using sign-refined
torsion we derive a skein relation for a normalized form of this polynomial.


title:
Space-like and time-like pion-rho transition form factors in the
  light-cone formalism

abstract:
  Having calculated the light-cone wave function of the pseudoscalar meson by
using two equivalent and fully covariant methods, we generalize such methods to
the valence Fock states of the vector meson in the light-cone formalism. We
investigate the decay constant of the $\rho$ meson $f_{\rho}$, the
$\gamma^{\ast} \pi \to \rho $ and $\gamma^* \rho \to \pi $ transition form
factors and especially the transition magnetic moments. By using two groups of
constraint parameters, we predict the space-like and time-like form factors
$F_{\pi \rho}(Q^2)$ and $F_{\rho \pi}(Q^2)$ at low and moderate energy scale
and the electromagnetic radius of these transition processes. In addition, we
extend our calculation to $\gamma^* \pi \to \omega$ space-like and time-like
form factors by using the same sets of parameters.


title: An operational interpretation for multipartite entanglement

abstract:
  We introduce an operational interpretation for pure-state global multipartite
entanglement based on quantum estimation. We show that the estimation of the
strength of low-noise locally depolarizing channels, as quantified by the
regularized quantum Fisher information, is directly related to the
Meyer-Wallach multipartite entanglement measure. Using channels that depolarize
across different partitions, we obtain related multipartite entanglement
measures. We show that this measure is the sum of expectation values of local
observables on two copies of the state.


title: Eigenvalue statistics of the real Ginibre ensemble

abstract:
  The real Ginibre ensemble consists of random $N \times N$ matrices formed
from i.i.d. standard Gaussian entries. By using the method of skew orthogonal
polynomials, the general $n$-point correlations for the real eigenvalues, and
for the complex eigenvalues, are given as $n \times n$ Pfaffians with explicit
entries. A computationally tractable formula for the cumulative probability
density of the largest real eigenvalue is presented. This is relevant to May's
stability analysis of biological webs.


title:
Structural fingerprinting in the transmission electron microscope:
  Overview and opportunities to implement enhanced strategies for nanocrystal
  identification

abstract:
  This paper illustrates the prospective need for structural fingerprinting
methods for nanocrystals. A review of the existing fingerprinting methods for
crystal structures by means of transmission electron microscopy which work for
a single setting of the specimen goniometer is given. Suggestions are made on
how some of these methods could be enhanced when nanocrystals and novel
instrumentation are involved, i.e. when either the kinematic or quasi-kinematic
scattering approximations are sufficiently well satisfied. A novel strategy for
lattice-fringe fingerprinting of nanocrystals from Fourier transforms of
high-resolution phase contrast transmission electron microscopy images is
briefly outlined. Nanocrystal structure specific limitations to the application
of this strategy are discussed. An appeal is made to share the structural data
of nanocrystals freely over the internet and infrastructure that would allow
this sharing is mentioned. A shorter version of this paper has been accepted
for publication in a special issue on the Structure of Nanocrystals of the
Zeitschrift fuer Kristallographie, International journal for structural,
physical, and chemical aspects of crystalline materials.


title: The Unusual Spectrum of Comet 96P/Machholz

abstract:
  We report spectra from 3000-5900 A for comet 96P/Machholz, obtained on 2007
Apr 27 UT with the 3-m Shane telescope at Lick Observatory. The spectra are
extremely carbon poor, and show a prominent NH_2 series, but no CN emission.
NH, NH_2, and C_2 gas production rates are (8.36 +/- 2.18)x10^25, (29.88 +/-
3.66)x10^25, and (4.52 +/- 0.61)x10^23 molecules sec^-1, respectively, as
determined from Haser model fits to the data. Upper limits to the gas
production rates for CN and C_3 are 7.5x10^22 and 2.0x10^23, respectively.
Though 96P is depleted in C_2 and C_3 relative to NH, it is even more depleted
in CN than other so-called "carbon-chain depleted" comets.


title: Electric fields in plasmas under pulsed currents

abstract:
  Electric fields in a plasma that conducts a high-current pulse are measured
as a function of time and space. The experiment is performed using a coaxial
configuration, in which a current rising to 160 kA in 100 ns is conducted
through a plasma that prefills the region between two coaxial electrodes. The
electric field is determined using laser spectroscopy and line-shape analysis.
Plasma doping allows for 3D spatially resolved measurements. The measured peak
magnitude and propagation velocity of the electric field is found to match
those of the Hall electric field, inferred from the magnetic-field front
propagation measured previously.


title: Generation interval contraction and epidemic data analysis

abstract:
  The generation interval is the time between the infection time of an infected
person and the infection time of his or her infector. Probability density
functions for generation intervals have been an important input for epidemic
models and epidemic data analysis. In this paper, we specify a general
stochastic SIR epidemic model and prove that the mean generation interval
decreases when susceptible persons are at risk of infectious contact from
multiple sources. The intuition behind this is that when a susceptible person
has multiple potential infectors, there is a ``race'' to infect him or her in
which only the first infectious contact leads to infection. In an epidemic, the
mean generation interval contracts as the prevalence of infection increases. We
call this global competition among potential infectors. When there is rapid
transmission within clusters of contacts, generation interval contraction can
be caused by a high local prevalence of infection even when the global
prevalence is low. We call this local competition among potential infectors.
Using simulations, we illustrate both types of competition.
  Finally, we show that hazards of infectious contact can be used instead of
generation intervals to estimate the time course of the effective reproductive
number in an epidemic. This approach leads naturally to partial likelihoods for
epidemic data that are very similar to those that arise in survival analysis,
opening a promising avenue of methodological research in infectious disease
epidemiology.


title:
On the Performance Evaluation of Encounter-based Worm Interactions Based
  on Node Characteristics

abstract:
  An encounter-based network is a frequently disconnected wireless ad-hoc
network requiring nearby neighbors to store and forward data utilizing mobility
and encounters over time. Using traditional approaches such as gateways or
firewalls for deterring worm propagation in encounter-based networks is
inappropriate. Because this type of network is highly dynamic and has no
specific boundary, a distributed counter-worm mechanism is needed. We propose
models for the worm interaction approach that relies upon automated beneficial
worm generation to alleviate problems of worm propagation in such networks. We
study and analyze the impact of key mobile node characteristics including node
cooperation, immunization, on-off behavior on the worm propagations and
interactions. We validate our proposed model using extensive simulations. We
also find that, in addition to immunization, cooperation can reduce the level
of worm infection. Furthermore, on-off behavior linearly impacts only timing
aspect but not the overall infection. Using realistic mobile network
measurements, we find that encounters are non-uniform, the trends are
consistent with the model but the magnitudes are drastically different.
Immunization seems to be the most effective in such scenarios. These findings
provide insight that we hope would aid to develop counter-worm protocols in
future encounter-based networks.


title: Quantum Teichm\"uller spaces and Kashaev's 6j-symbols

abstract:
  The Kashaev invariants of 3-manifolds are based on $6j$-symbols from the
representation theory of the Weyl algebra, a Hopf algebra corresponding to the
Borel subalgebra of $U_q(sl(2,\C))$. In this paper, we show that Kashaev's
$6j$-symbols are intertwining operators of local representations of quantum
Teichm\"uller spaces. This relates Kashaev's work with the theory of quantum
Teichm\"uller space, which was developed by Chekhov-Fock, Kashaev and continued
by Bonahon-Liu.


title:
Collective behavior in a granular jet: Emergence of a liquid with zero
  surface-tension

abstract:
  We perform the analog to the "water bell" experiment using non-cohesive
granular material. When a jet of granular material, many particles wide,
rebounds from a fixed cylindrical target, it deforms into a sharply-defined
sheet or cone with a shape that mimics a liquid with zero surface tension. The
particulate nature of granular material becomes apparent when the number of
particles in the cross-section of the jet is decreased and the emerging sheets
and cones broaden and gradually disintegrate into a broad spray. This
experiment has its counterpart in the behavior of the quark-gluon plasma
generated by collisions of gold ions at the Relativistic Heavy Ion Collider.
There a high density of inter-particle collisions gives rise to collective
behavior that has also been described as a liquid.


title: Eigenvalues and lambda constants on Riemannian submersions

abstract:
  Given a Riemannian submersion, we study the relation between lambda constants
introduced by G.Perelman on the base manifold and the total space of a
Riemannian submersion. We also discuss the relationship between the first
eigenvalues of Laplacians on the base manifold and that of the total space. The
quantities on warped products are discussed in detail.


title:
The Chemical Compositions of the Type II Cepheids -- The BL Her and W
  Vir Variables

abstract:
  Abundance analyses from high-resolution optical spectra are presented for 19
Type II Cepheids in the Galactic field. The sample includes both short-period
(BL Her) and long-period (W Vir) stars. This is the first extensive abundance
analysis of these variables. The C, N, and O abundances with similar spreads
for the BL Her and W Vir show evidence for an atmosphere contaminated with
$3\alpha$-process and CN-cycling products. A notable anomaly of the BL Her
stars is an overabundance of Na by a factor of about five relative to their
presumed initial abundances. This overabundance is not seen in the W Vir stars.
The abundance anomalies running from mild to extreme in W Vir stars but not
seen in the BL Her stars are attributed to dust-gas separation that provides an
atmosphere deficient in elements of high condensation temperature, notably Al,
Ca, Sc, Ti, and $s$-process elements. Such anomalies have previously been seen
among RV Tau stars which represent a long-period extension of the variability
enjoyed by the Type II Cepheids. Comments are offered on how the contrasting
abundance anomalies of BL Her and W Vir stars may be explained in terms of the
stars' evolution from the blue horizontal branch.


title: Hot Topics from the BABAR Experiment

abstract:
  With a sample of about 384 million BBbar pairs recorded with the BABAR
detector, we search for the flavor-changing charged current transition B+ ->
\tau\nu and perform an amplitude analysis of the effective flavor-changing
neutral current transition B+ -> \phi(1020)K*(892)+. We also extend our search
for other K* final states in the decay B0 -> phi(1020)K*0 with a large K*0 ->
K+pi- invariant mass. Two samples of events with one reconstructed hadronic B
decay or one reconstructed semileptonic B decay are selected, and in the recoil
a search for B+ -> \tau\nu is performed. We find a 2.6 sigma (3.2 sigma not
including expected background uncertainty) excess in data which can be
converted to a preliminary branching fraction central value of BR(B+ -> \tau\nu
) = (1.20 +0.40-0.38 +0.29-0.30 +-0.22) 10^-4. With the decay B+- ->
\phi(1020)K*(892)+-, twelve parameters are measured, where our measurements of
f_L=0.49+-0.05+-0.03, f_perp=0.21+-0.05+-0.02, and the strong phases point to
the presence of a substantial helicity-plus amplitude from a presently unknown
source.


title: Relativity tests by complementary rotating Michelson-Morley experiments

abstract:
  We report Relativity tests based on data from two simultaneous
Michelson-Morley experiments, spanning a period of more than one year. Both
were actively rotated on turntables. One (in Berlin, Germany) uses optical
Fabry-Perot resonators made of fused silica; the other (in Perth, Australia)
uses microwave whispering-gallery sapphire resonators. Within the standard
model extension, we obtain simultaneous limits on Lorentz violation for
electrons (5 coefficients) and photons (8) at levels down to $10^{-16}$,
improved by factors between 3 and 50 compared to previous work.

categories: physics.class-ph gr-qc hep-ph physics.hist-ph


title: Heegaard Floer homology and fibred 3--manifolds

abstract:
  Given a closed 3--manifold $Y$, we show that the Heegaard Floer homology
determines whether $Y$ fibres over the circle with a fibre of negative Euler
characteristic. This is an analogue of an earlier result about knots proved by
Ghiggini and the author.


title: Power Allocation for Discrete-Input Delay-Limited Fading Channels

abstract:
  We consider power allocation algorithms for fixed-rate transmission over
Nakagami-m non-ergodic block-fading channels with perfect transmitter and
receiver channel state information and discrete input signal constellations,
under both short- and long-term power constraints. Optimal power allocation
schemes are shown to be direct applications of previous results in the
literature. We show that the SNR exponent of the optimal short-term scheme is
given by m times the Singleton bound. We also illustrate the significant gains
available by employing long-term power constraints. In particular, we analyze
the optimal long-term solution, showing that zero outage can be achieved
provided that the corresponding short-term SNR exponent with the same system
parameters is strictly greater than one. Conversely, if the short-term SNR
exponent is smaller than one, we show that zero outage cannot be achieved. In
this case, we derive the corresponding long-term SNR exponent as a function of
the Singleton bound. Due to the nature of the expressions involved, the
complexity of optimal schemes may be prohibitive for system implementation. We
therefore propose simple sub-optimal power allocation schemes whose outage
probability performance is very close to the minimum outage probability
obtained by optimal schemes. We also show the applicability of these techniques
to practical systems employing orthogonal frequency division multiplexing.