title: New method for studying neutrino mixing and mass differences

abstract:
  Neutrino masses and mixing can be investigated by studying the behavior of a
radioactive bare nucleus which decays by emitting an electron into the open
atomic K shell BEFORE and DURING its weak decay by neutrino emission. The
initial nuclear state has a momentum spread required by Heisenberg. The wave
packet contains pairs of components with different momenta which can produce
neutrinos in two mass eigenstates with exactly the same energy and different
momenta. These neutrino amplitudes mix to produce a single electron-neutrino
state with the same energy. Since there is no information on which mass
eigenstates produced the neutrino this is a typical quantum mechanics
"two-slit" or "which path" experiment. A transition between the same initial
and a final states can go via two paths with a phase difference producing
interference and oscillations. Here the two paths are in momentum space
  A new oscillation phenomenon providing information about neutrino mixing is
obtained by following the nucleus before and during the decay. The analysis
starts with Stodolsky's proof that interference between states having different
energies cannot be observed in realistic experiments. Results then follow from
simple rigorous quantum mechanics without the hand waving and loopholes which
have confused many previous neutrino oscillation investigations.


title:
Phase glass and zero-temperature phase transition in a randomly
  frustrated two-dimensional quantum rotor model

abstract:
  The ground state of the quantum rotor model in two dimensions with random
phase frustration is investigated. Extensive Monte Carlo simulations are
performed on the corresponding (2+1)-dimensional classical model under the
entropic sampling scheme. For weak quantum fluctuation, the system is found to
be in a phase glass phase characterized by a finite compressibility and a
finite value for the Edwards-Anderson order parameter, signifying long-ranged
phase rigidity in both spatial and imaginary time directions. Scaling
properties of the model near the transition to the gapped, Mott insulator state
with vanishing compressibility are analyzed. At the quantum critical point, the
dynamic exponent $z_{\rm dyn}\simeq 1.17$ is greater than one. Correlation
length exponents in the spatial and imaginary time directions are given by
$\nu\simeq 0.73$ and $\nu_z\simeq 0.85$, respectively, both assume values
greater than 0.6723 of the pure case. We speculate that the phase glass phase
is superconducting rather than metallic in the zero current limit.


title: Chiral SU(3) Dynamics and Antikaon-Nuclear quasibound States

abstract:
  Recent developments are summarised concerning low-energy KbarN interactions
as they relate to the possible existence of antikaon-nuclear quasibound states.
An exploratory study of antikaons bound to finite nuclei is performed, with
emphasis on the evolution of such states from light to heavy nuclei (A = 16 -
208). The energy dependent, driving attractive KbarN interactions are
constructed using the s-wave coupled-channel amplitudes involving the
Lambda(1405) and resulting from chiral SU(3) dynamics, plus p-wave amplitudes
dominated by the Sigma(1385). Effects of Pauli and short-range correlations are
discussed. The decay width induced by K^-NN two-body absorption is estimated
and found to be substantial. It is concluded that Kbar-nuclear quasibound
states can possibly exist with binding energies ranging from 60 to 100 MeV, but
with short life times corresponding to decay widths of the similar magnitudes.


title:
Magnetic coupling in highly-ordered NiO/Fe3O4(110): Ultrasharp magnetic
  interfaces vs. long-range magnetoelastic interactions

abstract:
  We present a laterally resolved X-ray magnetic dichroism study of the
magnetic proximity effect in a highly ordered oxide system, i.e. NiO films on
Fe3O4(110). We found that the magnetic interface shows an ultrasharp
electronic, magnetic and structural transition from the ferrimagnet to the
antiferromagnet. The monolayer which forms the interface reconstructs to
NiFe2O4 and exhibits an enhanced Fe and Ni orbital moment, possibly caused by
bonding anisotropy or electronic interaction between Fe and Ni cations. The
absence of spin-flop coupling for this crystallographic orientation can be
explained by a structurally uncompensated interface and additional
magnetoelastic effects.


title: Analyticity Properties of Graham-Witten Anomalies

abstract:
  Analytic properties of Graham-Witten anomalies are considered. Weyl anomalies
according to their analytic properties are of type A (coming from
$\delta$-singularities in correlators of several energy-momentum tensors) or of
type B (originating in counterterms which depend logarithmically on a mass
scale). It is argued that all Graham-Witten anomalies can be divided into 2
groups: internal and external, and that all external anomalies are of type B,
whereas among internal anomalies there is one term of type A and all the rest
are of type B. This argument is checked explicitly for the case of a free
scalar field in a 6-dimensional space with a 2-dimensional submanifold.


title: An axisymmetric, hydrodynamical model for the torus wind in AGN

abstract:
  We report on time-dependent axisymmetric simulations of an X-ray excited flow
from a parsec-scale, rotating, cold torus around an active galactic nucleus.
Our simulations account for radiative heating and cooling and radiation
pressure force. The simulations follow the development of a broad bi-conical
outflow induced mainly by X-ray heating. We compute synthetic spectra predicted
by our simulations. The wind characteristics and the spectra support the
hypothesis that a rotationally supported torus can serve as the source of a
wind which is responsible for the warm absorber gas observed in the X-ray
spectra of many Seyfert galaxies.


title: Orbits in corotating and counterrotating double bars

abstract:
  The backbone of double bars is made out of double-frequency orbits, and
loops, their maps, indicate the bars' extent, morphology and dynamics.


title: Tremaine-Weinberg integrals for gas flows in double bars

abstract:
  We report on our attempts to achieve a nearly steady-state gas flow in
hydrodynamical simulations of doubly barred galaxies. After exploring the
parameter space, we construct two models, for which we evaluate the photometric
and the kinematic integrals, present in the Tremaine-Weinberg method, in search
of observational signatures of two rotating patterns. We show that such
signatures are often present, but a direct fit to data points is likely to
return incorrect pattern speeds. However, for a particular distribution of the
tracer, presented here, the values of the pattern speeds can be retrieved
reliably even with the direct fit.


title:
Compatibility of Einstein minimally coupled self interacting scalar
  field theory with the solar system tests of gravity

abstract:
  We examine the compatibility of the Einstein minimally coupled
self-interacting scalar field theory with the local tests of gravity. We find
that apart from the trivial case of the Schwarzschild-de Sitter solution with
constant scalar field the theory does not admit any other static solution,
which is consistent with the solar system tests of gravity.


title:
The performance of the blue prime focus Large Binocular Camera at the
  Large Binocular Telescope

abstract:
  We present the characteristics and some early scientific results of the first
instrument at the Large Binocular Telescope (LBT), the Large Binocular Camera
(LBC). Each LBT telescope unit will be equipped with similar prime focus
cameras. The blue channel is optimized for imaging in the UV-B bands and the
red channel for imaging in the VRIz bands. The corrected field-of-view of each
camera is approximately 30 arcminutes in diameter, and the chip area is
equivalent to a 23x23 arcmin2 field. In this paper we also present the
commissioning results of the blue channel. The scientific and technical
performance of the blue channel was assessed by measurement of the astrometric
distortion, flat fielding, ghosts, and photometric calibrations. These
measurements were then used as input to a data reduction pipeline applied to
science commissioning data. The measurements completed during commissioning
show that the technical performance of the blue channel is in agreement with
original expectations. Since the red camera is very similar to the blue one we
expect similar performance from the commissioning that will be performed in the
following months in binocular configuration. Using deep UV image, acquired
during the commissioning of the blue camera, we derived faint UV galaxy-counts
in a ~500 sq. arcmin. sky area to U(Vega)=26.5. These galaxy counts imply that
the blue camera is the most powerful UV imager presently available and in the
near future in terms of depth and extent of the field-of-view. We emphasize the
potential of the blue camera to increase the robustness of the UGR multicolour
selection of Lyman break galaxies at redshift z~3.


title: A Multifractal Analysis of Asian Foreign Exchange Markets

abstract:
  We analyze the multifractal spectra of daily foreign exchange rates for
Japan, Hong-Kong, Korea, and Thailand with respect to the United States Dollar
from 1991 to 2005. We find that the return time series show multifractal
spectrum features for all four cases. To observe the effect of the Asian
currency crisis, we also estimate the multifractal spectra of limited series
before and after the crisis. We find that the Korean and Thai foreign exchange
markets experienced a significant increase in multifractality compared to
Hong-Kong and Japan. We also show that the multifractality is stronge related
to the presence of high values of returns in the series.


title:
Fresnel Number Concept and Revision of some Characteristics in the
  Linear Theory of Focused Acoustic Beams

abstract:
  The advisability of the use of the Fresnel number as the measure
(characteristic) of the ratio of diffraction and focusing properties for
ultrasonic transducers and its radiated beams is proposed and demonstrated.
Althought this characteristic is more habitual in optics, in acoustics the
equivalent (mathematically although not fully in its physical meaning)
parameter of linear gain is used as a rule. However, the preference and the
more accuracy of the Fresnel number use is demonstrated here on the basis that
the usual determination of the linear gain parameter ceases to correspond to
the real value of the gain for low Fresnel number acoustic beams. It connects
with the linear effect of axial maximum pressure shift from the geometrical
focus towards the transducer. This effect is known for a long time, but here
the analytical formulas describing this shift with a high accuracy for
arbitrary Fresnel numbers are presented. As a consequence, also the analytical
dependence of the real gain on the Fresnel number is obtained.


title:
Bigravity : A bimetric model of the Universe. Positive and negative
  gravitational lensings

abstract:
  After a short summary of our bimetric model of the Universe, an exact
nonlinear solution is built, which demonstrates the existence of solutions for
our two coupled field equations system. In addition to the classical positive
gravitational lensing, this solution is shown to also lead to negative
gravitational lensing, a phenomenon previously described in 1995 (Astrophysics
and Space Science). Such negative lensing provides an alternative
interpretation for the observed faint magnitudes of high redshift galaxies, so
far considered as dwarf galaxies.


title:
Algebraic and combinatorial properties of ideals and algebras of uniform
  clutters of TDI systems

abstract:
  Let C be a uniform clutter, i.e., all the edges of C have the same size, and
let A be the incidence matrix of C. We denote the column vectors of A by
v1,...,vq. The vertex covering number of C, denoted by g, is the smallest
number of vertices in any minimal vertex cover of C. Under certain conditions
we prove that C is vertex critical. If C satisfies the max-flow min-cut
property, we prove that A diagonalizes over the integers to an identity matrix
and that v1,...,vq is a Hilbert basis. It is shown that if C has a perfect
matching such that C has the packing property and g=2, then A diagonalizes over
the integers to an identity matrix. If A is a balanced matrix we prove that any
regular triangulation of the cone generated by v1,...,vq is unimodular. Some
examples are presented to show that our results only hold for uniform clutters.
These results are closely related to certain algebraic properties, such as the
normality or torsion freeness, of blowup algebras of edge ideals and to
finitely generated abelian groups. They are also related to the theory of
Gr\"obner bases of toric ideals and to Ehrhart rings.


title:
Nonlinear change of on-axis pressure and intensity maxima positions and
  its relation with the linear focal shift effect

abstract:
  Experimental results related with the movement of the position of pressure
and intensity maxima along the axis of focused acoustic beams under increasing
driving voltages and its interpretation are presented. It is shown that in the
nonlinear regime the points of the pressure and intensity maximum are separated
and move differently along the axis, contrary to the linear regime, where these
points coincide. The considered effects are particularly strong in the case of
low-Fresnel-number beams.


title: A thermodynamic model for agglomeration of DNA-looping proteins

abstract:
  In this paper, we propose a thermodynamic mechanism for the formation of
transcriptional foci via the joint agglomeration of DNA-looping proteins and
protein-binding domains on DNA: The competition between the gain in protein-DNA
binding free energy and the entropy loss due to DNA looping is argued to result
in an effective attraction between loops. A mean-field approximation can be
described analytically via a mapping to a restricted random-graph ensemble
having local degree constraints and global constraints on the number of
connected components. It shows the emergence of protein clusters containing a
finite fraction of all looping proteins. If the entropy loss due to a single
DNA loop is high enough, this transition is found to be of first order.

categories: q-bio.SC cond-mat.soft cond-mat.stat-mech physics.bio-ph q-bio.GN


title:
The black hole mass -- stellar velocity dispersion correlation: bulges
  versus pseudobulges

abstract:
  We investigate the correlation between the supermassive black holes (SMBHs)
mass ($M_{\rm bh}$) and the stellar velocity dispersion ($\sigma_*$) in two
types of host galaxies: the early-type bulges (disk galaxies with classical
bulges or elliptical galaxies) and pseudobulges. In the form $\log (M_{\rm
bh}/{\rm M_\odot})=\alpha+\beta\log(\sigma_*/200 {\rm km s^{-1}})$, the
best-fit results for the 39 early-type bulges are the slope $\beta=4.06\pm0.28$
and the normalization $\alpha=8.28\pm0.05$; the best-fit results for the 9
pseudobulges are $\beta=4.5\pm1.3$, $\alpha=7.50\pm0.18$. Both relations have
intrinsic scatter in $\log M_{\rm bh}$ of $\lesssim$0.27 dex. The $M_{\rm
bh}$-$\sigma_*$ relation for pseudobulges is different from the relation in the
early-type bulges over the 3$\sigma$ significance level. The contrasting
relations indicate the formation and growth histories of SMBHs depend on their
host type. The discrepancy between the slope of the $M_{\rm bh}$-$\sigma_*$
relations using different definition of velocity dispersion vanishes in our
sample, a uniform slope will constrain the coevolution theories of the SMBHs
and their host galaxies more effectively. We also find the slope for the
``core'' elliptical galaxies at the high mass range of the relation appears
steeper ($\beta\simeq$ 5-6), which may be the imprint of their origin of
dissipationless mergers.


title: Currents in a Tokamak

abstract:
  A self-consistent analysis of the currents in a tokamak yields the result
that the parallel neutralizing current is given simply by the sum of currents
commonly called the bootstrap current and the Pfirsch-Schlueter current. An
expression is given relating the parallel and perpendicular pressure gradient
induced species flow velocities to the total current.


title: On k-resonant fullerene graphs

abstract:
  A fullerene graph $F$ is a 3-connected plane cubic graph with exactly 12
pentagons and the remaining hexagons. Let $M$ be a perfect matching of $F$. A
cycle $C$ of $F$ is $M$-alternating if the edges of $C$ appear alternately in
and off $M$. A set $\mathcal H$ of disjoint hexagons of $F$ is called a
resonant pattern (or sextet pattern) if $F$ has a perfect matching $M$ such
that all hexagons in $\mathcal H$ are $M$-alternating. A fullerene graph $F$ is
$k$-resonant if any $i$ ($0\leq i \leq k$) disjoint hexagons of $F$ form a
resonant pattern. In this paper, we prove that every hexagon of a fullerene
graph is resonant and all leapfrog fullerene graphs are 2-resonant. Further, we
show that a 3-resonant fullerene graph has at most 60 vertices and construct
all nine 3-resonant fullerene graphs, which are also $k$-resonant for every
integer $k>3$. Finally, sextet polynomials of the 3-resonant fullerene graphs
are computed.


title:
Reply to Comment on ``Ab Initio Study of 40-Ca with an Importance
  Truncated No-Core Shell Model''

abstract:
  We respond to Comment on our recent letter (Phys.Rev.Lett.99:092501,2007) by
Dean et al (arXiv:0709.0449).


title: A metamaterial analog of electromagnetically induced transparency

abstract:
  We present a new type of electromagnetic planar metamaterial that exhibit
strong dispersion at a local minimum of losses and is believed to be the first
metamaterial analog of electromagnetically induced transparency. We demonstrate
that pulses propagating through such metamaterials experience considerable
delay, whereas the thickness of the structure along the direction of wave
propagation is much smaller than the wavelength, which allows successive
stacking of multiple metamaterial slabs. This leads to a significant increase
in the band of normal dispersion, as well as in transmission levels.


title: A cosmic vector for dark energy

abstract:
  In this work we show that the presence of a vector field on cosmological
scales could explain the present phase of accelerated expansion of the
universe. The proposed theory contains no dimensional parameters nor potential
terms and does not require unnatural initial conditions in the early universe,
thus avoiding the so called cosmic coincidence problem. In addition, it fits
the data from high-redshift supernovae with excellent precision, making
definite predictions for cosmological parameters. Upcoming observations will be
able to clearly discriminate this model from standard cosmology with
cosmological constant.


title:
GLAST testing of a pulsar model matching H.E.S.S. observations of LS
  5039

abstract:
  LS 5039 is one of a handful of X-ray binaries that have been recently
detected at high-energy $\gamma$-rays, in this case, by the High-Energy
Stereoscopy Array (H.E.S.S.). The nature of this system is unknown: both a
black hole and a pulsar have been invoked as possible compact object
companions. Here we work with a model of the high energy phenomenology of the
system in which it is assumed that the companion object is a pulsar rotating
around an O6.5V star in the $\sim 3.9$ days orbit. The model assumes two
different sets of power-law spectral parameters of the interacting primary
leptons corresponding to the two orbital phase intervals defined by H.E.S.S. as
having different gamma-ray spectra and very-high-energy (VHE) cutoffs. We show
the H.E.S.S. phenomenology is completely explained by this model. We present
predictions for photons with lower energies (for $E>1 $ GeV), subject to test
in the forthcoming months with the GLAST satellite. We find that GLAST is able
to judge on this model within one year.


title:
Mapping of the molecular gas inflow towards the Seyfert nucleus of
  NGC4051 using Gemini NIFS

abstract:
  We present two-dimensional (2D) stellar and gaseous kinematics of the inner
~130x180 pc^2 of the Narrow Line Seyfert 1 galaxy NGC4051 at a sampling of 4.5
pc, from near-infrared K-band spectroscopic observations obtained with the
Gemini's Near-infrared Integral Field Spectrograph (NIFS). The turnover of the
stellar rotation curve at only ~55 pc from the nucleus, revealing a highly
concentrated gravitational potential. The stellar velocity dispersion of the
bulge is ~60 km/s -- implying on a nuclear black hole mass of ~10^6 M_sun --
within which patches of lower velocity dispersion suggest the presence of
regions of more recent star formation. The Brgamma emission-line shows no
rotation as well as no blueshifts or redshifts in excess of 30 km/s, and is
thus not restricted to the galaxy plane. The [CaVIII] coronal region is compact
but resolved, extending over the inner 75 pc. It shows the highest blueshifts
-- of up to -250 km/s, and the highest velocity dispersions, interpreted as due
to outflows from the active nucleus, supporting an origin close to the nucleus.
Subtraction of the stellar velocity field from the gaseous velocity field has
allowed us to isolate non-circular motions observed in the H_2 emitting gas.
The most conspicuous kinematic structures are two nuclear spiral arms. We
interpret these structures as inflows towards the nucleus, a result similar to
those of previous studies in which we have found streaming motions along
nuclear spirals in ionized gas using optical IFU observations. We have
calculated the mass inflow rate along the nuclear spiral arms, obtaining
$\dot{M}_{H_2} ~ 4x10^{-5} M_Sun/yr, value ~100 times smaller than the
accretion rate necessary to power the active nucleus.


title:
Relativistic echo dynamics and the stability of a beam of Landau
  electrons

abstract:
  We extend the concepts of echo dynamics and fidelity decay to relativistic
quantum mechanics, specifically in the context of Klein-Gordon and Dirac
equations under external electromagnetic fields. In both cases we define
similar expressions for the fidelity amplitude under perturbations of these
fields, and a covariant version of the echo operator. Transformation properties
under the Lorentz group are established. An alternate expression for fidelity
is given in the Dirac case in terms of a 4-current. As an application we study
a beam of Landau electrons perturbed by field inhomogeneities.


title:
CP-Conserving Unparticle Phase Effects on the Unpolarized and Polarized
  Direct CP Asymmetry in $b \to d \ell^+\ell^-$ Transition

abstract:
  We examine the unparticle CP-conserving phase effects on the direct CP
asymmetry for both polarized and unpolarized lepton in the inclusive $b\to d
\ell^+ \ell^-$ transition, where the flavor changing neutral currents are
forbidden at tree level but are induced by one-loop penguin diagrams. The
averaged polarized and unpolarized CP asymmetries depict strong dependency on
the unparticle parameters. In particular, a sizable discrepancy corresponding
to the standard model is achieved when the scale dimension value is $1<d_{\UP}<
2$. We see that the unparticle stuff significantly enhances, suppresses or
changes the sign of the CP asymmetry depending on the definite value of the
scaling dimension $d_{\UP}$. Especially, when $d_{\UP}\sim 1.1$ the CP
asymmetries vanish.


title: High resolution CMB power spectrum from the complete ACBAR data set

abstract:
  In this paper, we present results from the complete set of cosmic microwave
background (CMB) radiation temperature anisotropy observations made with the
Arcminute Cosmology Bolometer Array Receiver (ACBAR) operating at 150 GHz. We
include new data from the final 2005 observing season, expanding the number of
detector-hours by 210% and the sky coverage by 490% over that used for the
previous ACBAR release. As a result, the band-power uncertainties have been
reduced by more than a factor of two on angular scales encompassing the third
to fifth acoustic peaks as well as the damping tail of the CMB power spectrum.
The calibration uncertainty has been reduced from 6% to 2.1% in temperature
through a direct comparison of the CMB anisotropy measured by ACBAR with that
of the dipole-calibrated WMAP5 experiment. The measured power spectrum is
consistent with a spatially flat, LambdaCDM cosmological model. We include the
effects of weak lensing in the power spectrum model computations and find that
this significantly improves the fits of the models to the combined ACBAR+WMAP5
power spectrum. The preferred strength of the lensing is consistent with
theoretical expectations. On fine angular scales, there is weak evidence (1.1
sigma) for excess power above the level expected from primary anisotropies. We
expect any excess power to be dominated by the combination of emission from
dusty protogalaxies and the Sunyaev-Zel'dovich effect (SZE). However, the
excess observed by ACBAR is significantly smaller than the excess power at ell
> 2000 reported by the CBI experiment operating at 30 GHz. Therefore, while it
is unlikely that the CBI excess has a primordial origin; the combined ACBAR and
CBI results are consistent with the source of the CBI excess being either the
SZE or radio source contamination.


title: Muonium spectrum beyond the nonrelativistic limit

abstract:
  A generalization of the Gell-Mann-Low theorem is applied to the
antimuon-electron system. The bound state spectrum is extracted numerically. As
a result, fine and hyperfine structure are reproduced correctly near the
nonrelativistic limit (and for arbitrary masses). We compare the spectrum for
the relativistic value alpha = 0.3 with corresponding calculations in
light-front quantization.


title: Differential Galois Theory of Linear Difference Equations

abstract:
  We present a Galois theory of difference equations designed to measure the
differential dependencies among solutions of linear difference equations. With
this we are able to reprove Hoelder's Theorem that the Gamma function satisfies
no polynomial differential equation and are able to give general results that
imply, for example, that no differential relationship holds among solutions of
certain classes of q-hypergeometric functions.


title:
A new twist to an old story: HE 0450-2958, and the ULIRG$\to $(optically
  bright QSO) transition hypothesis

abstract:
  We report on interferometric imaging of the CO J=1--0 and J=3--2 line
emission from the controversial QSO/galaxy pair HE 0450--2958. {\it The
detected CO J=1--0 line emission is found associated with the disturbed
companion galaxy not the luminous QSO,} and implies $\rm M_{gal}(H_2)\sim
(1-2)\times 10^{10} M_{\odot}$, which is $\ga 30% $ of the dynamical mass in
its CO-luminous region. Fueled by this large gas reservoir this galaxy is the
site of an intense starburst with $\rm SFR\sim 370 M_{\odot} yr^{-1}$, placing
it firmly on the upper gas-rich/star-forming end of Ultra Luminous Infrared
Galaxies (ULIRGs, $\rm L_{IR}>10^{12} L_{\odot}$). This makes HE 0450--2958 the
first case of extreme starburst and powerful QSO activity, intimately linked
(triggered by a strong interaction) but not coincident. The lack of CO emission
towards the QSO itself renews the controversy regarding its host galaxy by
making a gas-rich spiral (the typical host of Narrow Line Seyfert~1 AGNs) less
likely. Finally, given that HE 0450--2958 and similar IR-warm QSOs are
considered typical ULIRG$\to $(optically bright QSO) transition candidates, our
results raise the possibility that some may simply be {\it gas-rich/gas-poor
(e.g. spiral/elliptical) galaxy interactions} which ``activate'' an optically
bright unobscured QSO in the gas-poor galaxy, and a starburst in the gas-rich
one. We argue that such interactions may have gone largely unnoticed even in
the local Universe because the combination of tools necessary to disentagle the
progenitors (high resolution and S/N optical {\it and} CO imaging) became
available only recently.


title: Solving One Dimensional Scalar Conservation Laws by Particle Management

abstract:
  We present a meshfree numerical solver for scalar conservation laws in one
space dimension. Points representing the solution are moved according to their
characteristic velocities. Particle interaction is resolved by purely local
particle management. Since no global remeshing is required, shocks stay sharp
and propagate at the correct speed, while rarefaction waves are created where
appropriate. The method is TVD, entropy decreasing, exactly conservative, and
has no numerical dissipation. Difficulties involving transonic points do not
occur, however inflection points of the flux function pose a slight challenge,
which can be overcome by a special treatment. Away from shocks the method is
second order accurate, while shocks are resolved with first order accuracy. A
postprocessing step can recover the second order accuracy. The method is
compared to CLAWPACK in test cases and is found to yield an increase in
accuracy for comparable resolutions.


title:
Parameters and Predictions for the Long-Period Transiting Planet HD
  17156b

abstract:
  We report high-cadence time-series photometry of the recently-discovered
transiting exoplanet system HD 17156, spanning the time of transit on UT 2007
October 1, from three separate observatories. We present a joint analysis of
our photometry, previously published radial velocity measurements, and times of
transit center for 3 additional events. Adopting the
spectroscopically-determined values and uncertainties for the stellar mass and
radius, we estimate a planet radius of Rp = 1.01 +/- 0.09 RJup and an
inclination of i = 86.5 +1.1 -0.7 degrees. We find a time of transit center of
Tc = 2454374.8338 +/- 0.0020 HJD and an orbital period of P = 21.21691 +/-
0.00071 days, and note that the 4 transits reported to date show no sign of
timing variations that would indicate the presence of a third body in the
system. Our results do not preclude the existence of a secondary eclipse, but
imply there is only a 9.2% chance for this to be present, and an even lower
probability (6.9%) that the secondary eclipse would be a non-grazing event. Due
to its eccentric orbit and long period, HD 17156b is a fascinating object for
the study of the dynamics of exoplanet atmospheres. To aid such future studies,
we present theoretical light curves for the variable infrared emission from the
visible hemisphere of the planet throughout its orbit.


title: Discovery of an Excited Pair State in Superfluid 3He

abstract:
  Order parameter collective modes are the fingerprint of a condensed phase.
The spectroscopy of these modes in superfluid $^3$He and unconventional
superconductors can provide key information on the symmetry of the condensate
as well as the microscopic pairing mechanism responsible for the ground state
and excitation energies. We report the discovery of a new collective mode in
superfluid $^3$He-B which we identify as an excited bound state of Cooper
pairs. We use interferometry within an acoustic cavity that is very sensitive
to changes in the velocity of transverse sound. Our measurements of sound
velocity and mode frequency, together with the observation of acoustic
birefringence indicate that this new mode is weakly bound with an excitation
energy within 1% of the pair-breaking edge of $2\Delta$. Based on the selection
rules for coupling of transverse sound to a collective mode in $^3$He-B,
combined with the observation of acoustic birefringence near the collective
mode frequency, we infer that the new mode is most likely a spin-triplet (S=1),
$f$-wave pair exciton (L=3) with total angular momentum, J=4. The existence of
a pair exciton with J=4 suggests an attractive, sub-dominant, $f$-wave pairing
interaction in liquid $^3$He.


title: Pion emission in 2H, 12C, 27Al, gamma pi+ reactions at threshold

abstract:
  The first data from MAX-lab in Lund, Sweden on pion production in
photonuclear reactions at threshold energies, is presented. The decrease of the
total yield of pi+ in gamma + 12C, 27Al reactions below 200 MeV as well as
differential, dsigma/dOmega, cross sections follow essentially predictions from
an intranuclear cascade model with an attractive potential for pion-nucleus
interaction in its simplest form. Double differential, d2sigma/dOmegadT, cross
sections at 176 MeV show, however, deviations from the model, which call for
refinements of nuclear and Coulomb potentials and possibly also for coherent
pion production mechanisms.


title:
The dynamic electric polarizability of a particle bound by a double
  delta potential

abstract:
  In this paper we derive an expression for the dynamic electric polarizability
of a particle bound by a double delta potential for frequencies below and above
the absolute value of the particle's ground state energy. The derived
expression will be used to study some of the fundamental features of the system
and its representation of real systems. In addition we derive a general
expression of the dynamic electric polarizability for a potential of
multi-delta functions.


title: Toward the Graphics Turing Scale on a Blue Gene Supercomputer

abstract:
  We investigate raytracing performance that can be achieved on a class of Blue
Gene supercomputers. We measure a 822 times speedup over a Pentium IV on a 6144
processor Blue Gene/L. We measure the computational performance as a function
of number of processors and problem size to determine the scaling performance
of the raytracing calculation on the Blue Gene. We find nontrivial scaling
behavior at large number of processors. We discuss applications of this
technology to scientific visualization with advanced lighting and high
resolution. We utilize three racks of a Blue Gene/L in our calculations which
is less than three percent of the the capacity of the worlds largest Blue Gene
computer.


title:
The Period-Luminosity Relation for the Large Magellanic Cloud Cepheids
  Derived from Spitzer Archival Data

abstract:
  Using Spitzer archival data from the SAGE (Surveying the Agents of a Galaxy's
Evolution) program, we derive the Cepheid period-luminosity (P-L) relation at
3.6, 4.5, 5.8 and 8.0 microns for Large Magellanic Cloud (LMC) Cepheids. These
P-L relations can be used, for example, in future extragalactic distance scale
studies carried out with the James Webb Space Telescope. We also derive Cepheid
period-color (P-C) relations in these bands and find that the slopes of the P-C
relations are relatively flat. We test the nonlinearity of these P-L relations
with the F statistical test, and find that the 3.6 micron, 4.5 micron and 5.8
micron P-L relations are consistent with linearity. However the 8.0 micron P-L
relation presents possible but inconclusive evidence of nonlinearity.


title: Heavy-quark contributions to the ratio F_L/F_2 at low x

abstract:
  We study the heavy-quark contribution to the proton structure functions
F_2^i(x,Q^2) and F_L^i(x,Q^2), with i=c,b, for small values of Bjorken's x
variable at next-to-lading order and provide compact formulas for their ratios
R_i=F_L^i/F_2^i that are useful to extract F_2^i(x,Q^2) from measurements of
the doubly differential cross section of inclusive deep-inelastic scattering at
DESY HERA. Our approach naturally explains why R_i is approximately independent
of x and the details of the parton distributions in the small-x regime.


title: Transient Detection and Classification

abstract:
  I provide an incomplete inventory of the astronomical variability that will
be found by next-generation time-domain astronomical surveys. These phenomena
span the distance range from near-Earth satellites to the farthest Gamma Ray
Bursts. The surveys that detect these transients will issue alerts to the
greater astronomical community; this decision process must be extremely robust
to avoid a slew of ``false'' alerts, and to maintain the community's trust in
the surveys. I review the functionality required of both the surveys and the
telescope networks that will be following them up, and the role of VOEvents in
this process. Finally, I offer some ideas about object and event
classification, which will be explored more thoroughly by other articles in
these proceedings.


title:
The Finite Temperature Pairing Gap of a Unitary Fermi Gas by Quantum
  Monte Carlo Calculations

abstract:
  We calculate the one-body temperature Green's (Matsubara) function of the
unitary Fermi gas via Quantum Monte Carlo, and extract the spectral weight
function $A(p,\omega)$ using the methods of maximum entropy and singular value
decomposition. From $A(p,\omega)$ we determine the quasiparticle spectrum,
which can be accurately parametrized by three functions of temperature: an
effective mass $m^*$, a mean-field potential $U$, and a gap $\Delta$. Below the
critical temperature $T_c=0.15\varepsilon_F$ the results for $m^*$, $U$ and
$\Delta$ can be accurately reproduced using an independent quasiparticle model.
We find evidence of a pseudogap in the fermionic excitation spectrum for
temperatures up to {$T^*\approx 0.20\varepsilon_{F} > T_c$}.


title: The Tully-Fisher Zero Point Problem

abstract:
  A long standing problem for hierarchical disk galaxy formation models has
been the simultaneous matching of the zero point of the Tully-Fisher relation
and the galaxy luminosity function (LF). We illustrate this problem for a
typical disk galaxy and discuss three solutions: low stellar mass-to-light
ratios, low initial dark halo concentrations, and no halo contraction. We
speculate that halo contraction may be reversed through a combination of mass
ejection through feedback and angular momentum exchange brought about by
dynamical friction between baryons and dark matter during the disk formation
process.


title:
Confronting Scaling Relations of Spiral Galaxies with Hierarchical
  Models of Disk Formation

abstract:
  The scaling relations between rotation velocity, size and luminosity form a
benchmark test for any theory of disk galaxy formation. We confront recent
theoretical models of disk formation to a recent large compilation of such
scaling relations. We stress the importance of achieving a fair comparison
between models and observations.


title:
Tetrahedra system Cudaca: high-temperature manifold of molecular
  configurations governing low-temperature properties

abstract:
  The Cudaca system composed of isolated Cu2+ S=1/2 tetrahedra with
antiferromagnetic exchange should exhibit properties of a frustrated quantum
spin system. ab initio density functional theory calculations for electronic
structure and molecular dynamics computations suggest a complex interplay
between magnetic exchange, electron delocalization and molecular vibrations.
Yet, extensive experimental characterization of Cudaca by means of synchrotron
x-ray diffraction, magnetization, specific heat and inelastic neutron
scattering reveal that properties of the real material can be only partly
explained by proposed theoretical models as the low temperature properties seem
to be governed by a manifold of molecular configurations coexisting at high
temperatures.


title:
STRINGVACUA: A Mathematica Package for Studying Vacuum Configurations in
  String Phenomenology

abstract:
  We give a simple tutorial introduction to the Mathematica package
STRINGVACUA, which is designed to find vacua of string-derived or inspired
four-dimensional N=1 supergravities. The package uses powerful
algebro-geometric methods, as implemented in the free computer algebra system
Singular, but requires no knowledge of the mathematics upon which it is based.
A series of easy-to-use Mathematica modules are provided which can be used both
in string theory and in more general applications requiring fast polynomial
computations. The use of these modules is illustrated throughout with simple
examples.


title:
WASP-4b: a 12th-magnitude transiting hot-Jupiter in the Southern
  hemisphere

abstract:
  We report the discovery of WASP-4b, a large transiting gas-giant planet with
an orbital period of 1.34 days. This is the first planet to be discovered by
the SuperWASP-South observatory and CORALIE collaboration and the first planet
orbiting a star brighter than 16th magnitude to be discovered in the Southern
hemisphere. A simultaneous fit to high-quality lightcurves and precision
radial-velocity measurements leads to a planetary mass of 1.22 +/- 0.1 MJup and
a planetary radius of 1.42 +/- 0.08 RJup. The host star is USNO-B1.0
0479-0948995, a G7V star of visual magnitude 12.5. As a result of the short
orbital period, the predicted surface temperature of the planet is 1776 K,
making it an ideal candidate for detections of the secondary eclipse at
infrared wavelengths.


title: Discovery and Study of Nearby Habitable Planets with Mesolensing

abstract:
  We demonstrate that gravitational lensing can be used to discover and study
planets in the habitable zones of nearby dwarf stars. If appropriate software
is developed, a new generation of monitoring programs will automatically
conduct a census of nearby planets in the habitable zones of dwarf stars. In
addition, individual nearby dwarf stars can produce lensing events at
predictable times; careful monitoring of these events can discover any planets
located in the zone of habitability. Because lensing can discover planets (1)
in face-on orbits, and (2) in orbit around the dimmest stars, lensing
techniques will provide complementary information to that gleaned through
Doppler and/or transit investigations. The ultimate result will be a
comprehensive understanding of the variety of systems with conditions similar
to those that gave rise to life on Earth.


title:
Discovery and Study of Nearby Planetary and Binary Systems Via
  Mesolensing

abstract:
  This paper is devoted to exploring how we can discover and study nearby (<
1-2 kpc) planetary and binary systems by observing their action as
gravitational lenses. Lensing can extend the realm of nearby binaries and
planets that can be systematically studied to include dark and dim binaries,
and face-on systems. As with more traditional studies, which use light from the
system, orbital parameters (including the total mass, mass ratio, and orbital
separation) can be extracted from lensing data, Also in common with these
traditional methods, individual systems can be targeted for study. We discuss
the specific observing strategies needed in order to optimize the discovery and
study of nearby planetary and binary systems by observing their actions as
lenses.


title: Theory of Bergman spaces (I)

abstract:
  These notes are part of the research seminar with title "Theory of Bergman
spaces and related function spaces" that took place in the University of Crete,
Department of Mathematics (September 2006- December 2007), in the framework of
the research program PYTHAGORAS II(75% European funds--25% Greek national
funds).


title: Symplectic 4-manifolds with a free circle action

abstract:
  The content of this unpublished paper is subsumed in successive work of the
authors, in particular arXiv:1102.0820, arXiv:1102.0821 and arXiv:1205.2434.


title:
Teaching spreadsheet development using peer audit and self-audit methods
  for reducing error

abstract:
  Recent research has highlighted the high incidence of errors in spreadsheet
models used in industry. In an attempt to reduce the incidence of such errors,
a teaching approach has been devised which aids students to reduce their
likelihood of making common errors during development. The approach comprises
of spreadsheet checking methods based on the commonly accepted educational
paradigms of peer assessment and self-assessment. However, these paradigms are
here based upon practical techniques commonly used by the internal audit
function such as peer audit and control and risk self-assessment. The result of
this symbiosis between educational assessment and professional audit is a
method that educates students in a set of structured, transferable skills for
spreadsheet error-checking which are useful for increasing error-awareness in
the classroom and for reducing business risk in the workplace.


title:
Impact of in-plane currents on magnetoresistance properties of an
  exchange-biased spin-valve with insulating antiferromagnetic layer

abstract:
  The impact of in-plane alternating currents on the exchange bias, resistance,
and magnetoresistance of a CoFe/NiCoO/CoFe/Cu/CoFe spin-valve is studied. With
increasing current, the resistance is increased while the maximum
magnetoresistance ratio decreases. Noticeably, the reversal of the pinned layer
is systematically suppressed in both field sweeping directions. Since the NiCoO
oxide is a good insulator, it is expected that the ac current flows only in the
CoFe/Cu/CoFe top layers, thus ruling out any presence of spin-transfer torque
acting on the spins in the antiferromagnetic layer. Instead, our measurements
show clear evidences for the influence of Joule heating caused by the current.
Moreover, results from temperature-dependent measurements very much resemble
those of the current dependence, indicating that the effect of Joule heating
plays a major role in the current-in-plane spin-valve configurations. The
results also suggest that spin-transfer torques between ferromagnetic layers
might still exist and compete with the exchange bias at sufficiently high
currents.


title: An Evaluation of a Structured Spreadsheet Development Methodology

abstract:
  This paper presents the results of an empirical evaluation of the quality of
a structured methodology for the development of spreadsheet models, proposed in
numerous previous papers by Rajalingham K, Knight B and Chadwick D et al. This
paper also describes an improved version of their methodology, supported by
appropriate examples. The principal objective of a structured and disciplined
methodology for the construction of spreadsheet models is to reduce the
occurrence of user-generated errors in the models. The evaluation of the
effectiveness of the methodology has been carried out based on a number of
real-life experiments. The results of these experiments demonstrate the
methodology's potential for improved integrity control and enhanced
comprehensibility of spreadsheet models.


title:
Polarization evolution accompanying the very early sharp decline of GRB
  X-ray afterglows

abstract:
  In the synchrotron radiation model, the polarization property depends on both
the configuration of the magnetic field and the geometry of the visible
emitting region. Some peculiar behaviors in the X-ray afterglows of {\it Swift}
gamma-ray bursts (GRBs), such as energetic flares and the plateau followed by a
sharp drop, might by highly linearly-polarized because the outflows powering
these behaviors may be Poynting-flux dominated. Furthermore, the broken-down of
the symmetry of the visible emitting region may be hiding in current X-ray data
and will give rise to interesting polarization signatures. In this work we
focus on the polarization accompanying the very early sharp decline of GRB
X-ray afterglows. We show that strong polarization evolution is possible in
both the high latitude emission model and the dying central engine model which
are used to interpret this sharp X-ray decline. It is thus not easy to
efficiently probe the physical origin of the very early X-ray sharp decline
with future polarimetry. Strong polarization evolution is also possible in the
decline phase of X-ray flares and in the shallow decline phase of X-ray light
curves characterized by chromatic X-ray VS. Optical breaks. An {\it XRT}-like
detector but with polarization capability on board a {\em Swift}-like satellite
would be suitable to test our predictions.


title: On the excluded space in applications of Feshbach projection formalism

abstract:
  Various model applications in nuclear structure and reactions have been
formulated starting with the Feshbach projection formalism. In recent studies a
truncated excluded space has been enumerated to facilitate calculation and
identify a convergence in expansions within that truncation. However, the
effect of any remainder must be addressed before results from such can be
considered physical.


title: Transport in a Clean Graphene Sheet at Finite Temperature and Frequency

abstract:
  We calculate the conductivity of a clean graphene sheet at finite
temperatures starting from the tight-binding model. We obtain a finite value
for the dc-conductivity at zero temperature. For finite temperature, the
spontaneous electron-hole creation, responsible for the finite conductivity at
zero temperature, is washed out and the dc-conductivity yields zero. Our
results are in agreement with calculations based on the field-theoretical model
for graphene.


title: A Gravity Dual of Metastable Dynamical Supersymmetry Breaking

abstract:
  Metastable, supersymmetry-breaking configurations can be created in flux
geometries by placing antibranes in warped throats. Via gauge/gravity duality,
such configurations should have an interpretation as supersymmetry-breaking
states in the dual field theory. In this paper, we perturbatively determine the
asymptotic supergravity solutions corresponding to anti-D3-brane probes placed
at the tip of the cascading warped deformed conifold geometry, which is dual to
an SU(N+M) x SU(N) gauge theory. The backreaction of the antibranes has the
effect of introducing imaginary anti-self-dual flux, squashing the compact part
of the space and forcing the dilaton to run. Using the generalization of
holographic renormalization to cascading geometries, we determine the
expectation values of operators in the dual field theory in terms of the
asymptotic values of the supergravity fields.


title: A new bound on the number of special fibers in a pencil of curves

abstract:
  In the previous paper by Pereira and the author, it was proved that any
pencil of plane curves of degree greater than one with irreducible generic
fiber can have at most five completely reducible fibers although no examples
with five such fibers were ever found. Recently Janis Stipins has proved that
if any two fibers of a pencil intersect transversally then it cannot have five
completely reducible fibers. In this paper we generalize the Stipins result to
arbitrary pencils. We also include into consideration more general special
fibers that are the unions of lines and non-reduced curves. These fibers are
important for characteristic varieties of line complements.


title:
Approximate stabilization of a quantum particle in a 1D infinite square
  potential well

abstract:
  We consider a non relativistic charged particle in a 1-dimensional infinite
square potential well. This quantum system is subjected to a control, which is
a uniform (in space) time depending electric field. It is represented by a
complex probability amplitude solution of a Schrodinger equation on a
1-dimensional bounded domain, with Dirichlet boundary conditions. We prove the
almost global approximate stabilization of the eigenstates by explicit feedback
laws.


title:
Determination of the Equation of State of a Two-Component Fermi Gas at
  Unitarity

abstract:
  We report on the measurement of the equation of state of a two-component
Fermi gas of $^6$Li atoms with resonant interactions. By analyzing the
\textit{in situ} density distributions of a population-imbalanced Fermi mixture
reported in the recent experiment [Y. Shin \textit{et al.}, Nature
\textbf{451}, 689 (2008)], we determine the energy density of a resonantly
interacting Fermi gas as a function of the densities of the two components. We
present a method to determine the equation of state directly from the shape of
the trapped cloud, where the fully-polarized, non-interacting ideal Fermi gas
in the outer region provides the absolute calibration of particle density. From
the density profiles obtained at the lowest temperature, we estimate the
zero-temperature equation of state.


title: Sparse Fourier Transform via Butterfly Algorithm

abstract:
  We introduce a fast algorithm for computing sparse Fourier transforms
supported on smooth curves or surfaces. This problem appear naturally in
several important problems in wave scattering and reflection seismology. The
main observation is that the interaction between a frequency region and a
spatial region is approximately low rank if the product of their radii are
bounded by the maximum frequency. Based on this property, equivalent sources
located at Cartesian grids are used to speed up the computation of the
interaction between these two regions. The overall structure of our algorithm
follows the recently-introduced butterfly algorithm. The computation is further
accelerated by exploiting the tensor-product property of the Fourier kernel in
two and three dimensions. The proposed algorithm is accurate and has an $O(N
\log N)$ complexity. Finally, we present numerical results in both two and
three dimensions.


title: Dynamical Mass of GJ 802B: a brown dwarf in a triple system

abstract:
  We report a dynamical measurement of the mass of the brown dwarf GJ 802B
using aperture-masking interferometry and astrometry. In addition, we report
the discovery that GJ 802A is itself a close spectroscopic non-eclipsing binary
with a 19 hour period. We find the mass of GJ 802B to be
$0.063\pm0.005$M$_\sun$. GJ 802 has kinematics inconsistent with a young star
and more consistent with the thick disk population, implying a system age of
$\sim$10 GYr. However, model evolutionary tracks for GJ 802B predict system
ages of $\sim$2 GYr, suggesting that brown dwarf evolutionary models may be
underestimating luminosity for old brown dwarfs.


title: Multiplicity matrices for the affine graded Hecke algebra

abstract:
  In this paper, we look at the problem of determining the composition factors
for the affine graded Hecke algebra via the computation of Kazhdan-Lusztig type
polynomials. We review the algorithms of \cite{L1,L2}, and use them in
particular to compute, at every real central character which admits tempered
modules, the geometric parameterization, the Kazhdan-Lusztig polynomials, the
composition series, and the Iwahori-Matsumoto involution for the
representations with Iwahori fixed vectors of the split $p$-adic groups of type
$G_2$ and $F_4$.


title: Helioscope Bounds on Hidden Sector Photons

abstract:
  The flux of hypothetical "hidden photons" from the Sun is computed under the
assumption that they interact with normal matter only through kinetic mixing
with the ordinary standard model photon. Requiring that the exotic luminosity
is smaller than the standard photon luminosity provides limits for the mixing
parameter down to 10^-14, depending on the hidden photon mass. Furthermore, it
is pointed out that helioscopes looking for solar axions are also very
sensitive to hidden photons. The recent results of the CAST collaboration are
used to further constrain the mixing parameter at low masses m<1 eV where the
luminosity bound is weaker. In this regime the solar hidden photon flux has a
sizable contribution of longitudinally polarized hidden photons of low energy
which are invisible for current helioscopes.


title: Acceleration and Classical Electromagnetic Radiation

abstract:
  Classical radiation from an accelerated charge is reviewed along with the
reciprocal topic of accelerated observers detecting radiation from a static
charge. This review commemerates Bahram Mashhoon's 60th birthday.


title:
Low excitation structure of $^{10}$B probed by scattering of electron
  and of 197 MeV polarized protons

abstract:
  Cross-section and analyzing power data from 197 MeV $(p,p')$ scattering and
longitudinal and transverse form factors for electron scattering to low lying
states in $^{10}$B have been analyzed as tests of the structure of the nuclear
states when they are described using a no-core $(0+2)\hbar\omega$ shell model.
While the results obtained from the shell model clearly show the need of other
elements, three-body forces in particular, to explain the observed spectrum,
the reasonable level of agreement obtained in the analyses of the scattering
data suggest that the wavefunctions from our shell model using only a two-body
potential are credible. Any changes to the wavefunctions with the introduction
of three-body forces in the shell model Hamiltonian should therefore be
relatively minor.


title:
A Lie-theoretic construction of representations of the degenerate affine
  and double affine Hecke algebras of type $BC_n$

abstract:
  Let G=GL(N), K=GL(p)xGL(q), where p+q=N, and n be a positive integer. We
construct a functor from the category of Harish-Chandra modules for the pair
(G,K) to the category of representations of the degenerate affine Hecke algebra
of type B_n, and a functor from the category of K-monodromic twisted D-modules
on G/K to the category of representations of the degenerate double affine Hecke
algebra of type BC_n; the second functor is an extension of the first one.
These functors are generalizations of the type A functors from q-alg/9710037
and math/0702670, respectively.


title:
Scintillation time dependence and pulse shape discrimination in liquid
  argon

abstract:
  Using a single-phase liquid argon detector with a signal yield of 4.85
photoelectrons per keV of electronic-equivalent recoil energy (keVee), we
measure the scintillation time dependence of both electronic and nuclear
recoils in liquid argon down to 5 keVee. We develop two methods of pulse shape
discrimination to distinguish between electronic and nuclear recoils. Using one
of these methods, we measure a background and statistics-limited level of
electronic recoil contamination to be $7.6\times10^{-7}$ between 60 and 128 keV
of nuclear recoil energy (keVr) for a nuclear recoil acceptance of 50% with no
nuclear recoil-like events above 72 keVr. Finally, we develop a maximum
likelihood method of pulse shape discrimination using the measured
scintillation time dependence and predict the sensitivity to WIMP-nucleon
scattering in three configurations of a liquid argon dark matter detector.


title: Left inverses of matrices with polynomial decay

abstract:
  The algebra of Schur operators on l^2 is known not to be inverse-closed. When
l^2=l^2(X) where X is a metric space, we can consider elements of the Schur
algebra with certain decay at infinity. For instance if X has the doubling
property, then Q. Sun has proved that the weighted Schur algebra for a strictly
polynomial weight is inverse-closed. Here, we prove a result dealing with
left-invertibility. Namely, if such an operator is bounded below in l^p for
some p, then it is bounded below for all q, and it admits a left-inverse in the
weighted Schur algebra.


title: The Higher Transvectants are Redundant

abstract:
  Let A, B denote generic binary forms, and let u_r = (A,B)_r denote their r-th
transvectant in the sense of classical invariant theory. In this paper we
classify all the quadratic syzygies between the u_r. As a consequence, we show
that each of the higher transvectants u_r, r>1, is redundant in the sense that
it can be completely recovered from u_0 and u_1. This result can be
geometrically interpreted in terms of the incomplete Segre imbedding. The
calculations rely upon the Cauchy exact sequence of SL_2-representations, and
the notion of a 9-j symbol from the quantum theory of angular momentum. We give
explicit computational examples for SL_3, g_2 and S_5 to show that this result
has possible analogues for other categories of representations.


title: Unparticle Self-Interactions and Their Collider Implications

abstract:
  In unparticle physics, operators of the conformal sector have
self-interactions, and these are unsuppressed for strong coupling. The 3-point
interactions are completely determined by conformal symmetry, up to a constant.
We do not know of any theoretical upper bounds on this constant. Imposing
current experimental constraints, we find that these interactions mediate
spectacular collider signals, such as $pp -> U -> UU -> \gamma \gamma \gamma
\gamma$, $\gamma \gamma ZZ$, $ZZZZ$, $\gamma \gamma l^+ l^-$, $ZZ l^+ l^-$, and
$4l$, with cross sections of picobarns or larger at the Large Hadron Collider.
Self-interactions may therefore provide the leading discovery prospects for
unparticle physics.


title: Comments on "Reverse auction: the lowest positive integer game"

abstract:
  In Zeng et al. [Fluct. Noise Lett. 7 (2007) L439--L447] the analysis of the
lowest unique positive integer game is simplified by some reasonable
assumptions that make the problem tractable for arbitrary numbers of players.
However, here we show that the solution obtained for rational players is not a
Nash equilibrium and that a rational utility maximizer with full computational
capability would arrive at a solution with a superior expected payoff. An exact
solution is presented for the three- and four-player cases and an approximate
solution for an arbitrary number of players.


title: Plasmonic Metamaterial With Coupling Induced Transparency

abstract:
  A plasmonic "molecule" consisting of a radiative element coupled with a
sub-radiant (dark) element is theoretically investigated. The plasmonic
"molecule" shows close resemblance to the electromagnetically induced
transparency (EIT) in an atomic system. Because of its sub-wavelength
dimension, this EIT-like "molecule" can be used as building block to construct
a "slow light" plasmonic metamaterial.


title: Unified electronic phase diagram for hole-doped high-Tc cuprates

abstract:
  We have analyzed various characteristic temperatures and energies of
hole-doped high-Tc cuprates as a function of a dimensionless hole-doping
concentration (pu). Entirely based on the experimental grounds we construct a
unified electronic phase diagram (UEPD), where three characteristic
temperatures (T*'s) and their corresponding energies (E*'s) converge as pu
increases in the underdoped regime. T*'s and E*'s merge together with the Tc
curve and 3.5kBTc curve at pu - 1.1 in the overdoped regime, respectively. They
finally go to zero at pu - 1.3. The UEPD follows an asymmetric half-dome-shaped
Tc curve in which Tc appears at pu - 0.4, reaches a maximum at pu - 1, and
rapidly goes to zero at pu - 1.3. The asymmetric half-dome-shaped Tc curve is
at odds with the well-known symmetric superconducting dome for La2-xSrxCuO4
(SrD-La214), in which two characteristic temperatures and energies converge as
pu increases and merge together at pu - 1.6, where Tc goes to zero. The UEPD
clearly shows that pseudogap phase precedes and coexists with high temperature
superconductivity in the underdoped and overdoped regimes, respectively. It is
also clearly seen that the upper limit of high-Tc cuprate physics ends at a
hole concentration that equals to 1.3 times the optimal doping concentration
for almost all high-Tc cuprate materials, and 1.6 times the optimal doping
concentration for the SrD-La214. Our analysis strongly suggests that pseudogap
is a precursor of high-Tc superconductivity, the observed quantum critical
point inside the superconducting dome may be related to the end point of UEPD,
and the normal state of the underdoped and overdoped high temperature
superconductors cannot be regarded as a conventional Fermi liquid phase.

categories: cond-mat.supr-con astro-ph cond-mat.mtrl-sci cond-mat.str-el


title: Razborov flag algebras as algebras of measurable functions

abstract:
  These are some brief notes on the translation from Razborov's
recently-developed notion of flag algebra into the lexicon of functions and
measures on certain abstract Cantor spaces (totally disconnected compact metric
spaces).


title:
Demonstration of One Cutoff Phase Space Slicing Method: Next-to-Leading
  Order QCD Corrections to the $tW$ Associated Production in Hadron Collision

abstract:
  We present a detailed calculation of next-to-leading order QCD corrections to
the $tW$ associated production using the one cutoff phase space slicing method.
Such QCD corrections have been calculated independently by two groups already,
however, a number of differences were found. It is desirable to have a third
party calculation to make a crossing check. In this note, we present our
complete results of the virtual corrections which are not shown in the
literature so far. The numerical comparison will be presented in the
forthcoming paper. As a demonstration of the one cutoff phase space slicing
method, we also show in details how to organize the color ordered amplitudes
and how to slice the soft and collinear phase space regions.


title:
A Morphological Approach to the Pulsed Emission from Soft Gamma
  Repeaters

abstract:
  We present a geometrical methodology to interpret the periodical light curves
of Soft Gamma Repeaters based on the magnetar model and the numerical
arithmetic of the three-dimensional magnetosphere model for the young pulsars.
The hot plasma released by the star quake is trapped in the magnetosphere and
photons are emitted tangent to the local magnetic field lines. The variety of
radiation morphologies in the burst tails and the persistent stages could be
well explained by the trapped fireballs on different sites inside the closed
field lines. Furthermore, our numerical results suggests that the pulse profile
evolution of SGR 1806-20 during the 27 December 2004 giant flare is due to a
lateral drift of the emitting region in the magnetosphere.


title: The canonical sheaf of Du Bois singularities

abstract:
  We prove that a Cohen-Macaulay normal variety $X$ has Du Bois singularities
if and only if $\pi_*\omega_{X'}(G) \simeq \omega_X$ for a log resolution $\pi:
X' \to X$, where $G$ is the reduced exceptional divisor of $\pi$. Many basic
theorems about Du Bois singularities become transparent using this
characterization (including the fact that Cohen-Macaulay log canonical
singularities are Du Bois).
  We also give a straightforward and self-contained proof that (generalizations
of) semi-log-canonical singularities are Du Bois, in the Cohen-Macaulay case.
It also follows that the Kodaira vanishing theorem holds for semi-log-canonical
varieties and that Cohen-Macaulay semi-log-canonical singularities are
cohomologically insignificant in the sense of Dolgachev.


title: Scattering on the Moduli Space of N=4 Super Yang-Mills

abstract:
  We calculate one-loop scattering amplitudes in N=4 super Yang-Mills theory
away from the origin of the moduli space and demonstrate that the results are
extremely simple, in much the same way as in the conformally invariant theory.
Specifically, we consider the model where an SU(2) gauge group is spontaneously
broken down to U(1). The complete component Lagrange density of the model is
given in a form useful for perturbative calculations. We argue that the
scattering amplitudes with massive external states deserve further study.
Finally, our work shows that loop corrections can be readily computed in a
mass-regulated N=4 theory, which may be relevant in trying to connect
weak-coupling results with those at strong coupling, as discussed recently by
Alday and Maldacena.


title:
Current-voltage characteristics of a graphene nanoribbon field-effect
  transistor

abstract:
  We present an analytical device model for a field-effect transistor based on
a heterostructure which consists of an array of nanoribbons clad between the
highly conducting substrate (the back gate) and the top gate controlling the
source-drain current. The equations of the model of a graphene nanoribbon
field-effect transistor (GNR-FET) include the Poisson equation in the weak
nonlocality approximation. Using this model, we find explicit analytical
formulas for the spatial distributions of the electric potential along the
channel and for the GNR-FET current-voltage characteristics (the dependences of
the source-drain current on the drain voltages as well as on the back gate and
top gate voltages) for different geometric parameters of the device. It is
shown that the shortening of the top gate can result in a substantial
modification of the GNR-FET current-voltage characteristics.


title:
Secure Multiparty Quantum Computation with (Only) a Strict Honest
  Majority

abstract:
  Secret sharing and multiparty computation (also called "secure function
evaluation") are fundamental primitives in modern cryptography, allowing a
group of mutually distrustful players to perform correct, distributed
computations under the sole assumption that some number of them will follow the
protocol honestly. This paper investigates how much trust is necessary -- that
is, how many players must remain honest -- in order for distributed quantum
computations to be possible.
  We present a verifiable quantum secret sharing (VQSS) protocol, and a general
secure multiparty quantum computation (MPQC) protocol, which can tolerate any
(n-1)/2 (rounded down) cheaters among n players. Previous protocols for these
tasks tolerated (n-1)/4 (rounded down) and (n-1)/6 (rounded down) cheaters,
respectively. The threshold we achieve is tight - even in the classical case,
``fair'' multiparty computation is not possible if any set of n/2 players can
cheat.
  Our protocols rely on approximate quantum error-correcting codes, which can
tolerate a larger fraction of errors than traditional, exact codes. We
introduce new families of authentication schemes and approximate codes tailored
to the needs of our protocols, as well as new state purification techniques
along the lines of those used in fault-tolerant quantum circuits.


title:
Characteristics and benchmarks of entanglement of mixed states -- the
  two qubit case

abstract:
  We propose that the entanglement of mixed states is characterised properly in
terms of a probability density function $\mathcal{P}_{\rho}(\mathcal{E})$.
There is a need for such a measure since the prevalent measures (such as
\textit{concurrence} and \textit{negativity}) for two qubit systems are rough
benchmarks, and not monotones of each other. Focussing on the two qubit states,
we provide an explicit construction of $\mathcal{P}_{\rho}(\mathcal{E})$ and
show that it is characterised by a set of parameters, of which concurrence is
but one particular combination. $\mathcal{P}_{\rho}(\mathcal{E})$ is manifestly
invariant under $SU(2) \times SU(2)$ transformations. It can, in fact,
reconstruct the state up to local operations - with the specification of at
most four additional parameters. Finally the new measure resolves the
controversy regarding the role of entanglement in quantum computation in NMR
systems.


title: Structure Formation, Backreaction and Weak Gravitational Fields

abstract:
  There is an ongoing debate in the literature as to whether the effects of
averaging out inhomogeneities (``backreaction'') in Cosmology can be large
enough to account for the acceleration of the scale factor in the FLRW models.
In particular, some simple models of structure formation studied in the
literature seem to indicate that this is indeed possible, and it has also been
suggested that the perturbed FLRW framework is no longer a good approximation
during structure formation, when the density contrast becomes nonlinear. In
this work we attempt to clarify the situation to some extent, using a fully
relativistic model of pressureless spherical collapse. We find that whereas
averaging during structure formation can lead to acceleration via a selective
choice of averaging domains, the acceleration is not present when more generic
domains are used for averaging. Further, we show that for most of the duration
of the collapse, matter velocities remain small, and the perturbed FLRW form of
the metric can be explicitly recovered, in the structure formation phase. We
also discuss the fact that the magnitude of the average effects of
inhomogeneities depends on the scale of averaging, and while it may not be
completely negligible on intermediate scales, it is expected to remain small
when averaging on suitably large scales.


title: Einstein-aether gravity: a status report

abstract:
  This paper reviews the theory, phenomenology, and observational constraints
on the coupling parameters of Einstein-aether gravity, i.e. General Relativity
coupled to a dynamical unit timelike vector field. A discussion of open
questions concerning both phenomenology and fundamental issues is included.


title:
Fundamental Planes, and the "barless" M-sigma relation, for supermassive
  black holes

abstract:
  The residuals about the standard M-sigma relation correlate with the
effective radius, absolute magnitude, and Sersic index of the host bulge -
although, it is noted here that the elliptical galaxies do not partake in such
correlations. Moreover, it is revealed that barred galaxies (with their
relatively small, faint, and low stellar concentration bulges) can deviate from
the M-sigma relation by delta(log M) = -0.5 to -1.0 dex (in the sense that
their sigma values are too large) and generate much of the aforementioned
correlations. Removal of the seven barred galaxies from the Tremaine et al. set
of 31 galaxies results in a ``barless M-sigma'' relation with an intrinsic
scatter of 0.17 dex (cf. 0.27 dex for the 31 galaxies) and a total scatter of
0.25 dex (cf. 0.34 dex for the 31 galaxies). The introduction of third
parameters does not reduce the scatter of the barless M-sigma relation.
Furthermore, removal of the barred galaxies, or all the disk galaxies, from an
expanded and updated set of 40 galaxies with reliable black hole mass
measurements gives a consistent result, such that log(M_bh/M_sun) =
(8.25+/-0.05) + (3.68+/-0.25)log [sigma/200].
  The "barless" sigma-L relation for galaxies with black hole mass measurements
is found to be consistent with that from the SDSS sample of early-type
galaxies. In addition, the barless M-sigma relation, the M-L relation, and the
M-n relation are all shown to yield SMBH masses less than 2-4 x 10^9 M_sun.


title: Non-Hermitian Hamiltonian versus E=0 localized states

abstract:
  We analyze the zero energy solutions, of a two dimensional system which
undergoes a non-radial symmetric, complex potential V(r,$\phi$). By virtue of
the coherent states concept, the localized states are constructed, and the
consequences of the imaginary part of the potential are found both analytically
and schematically.


title: 3D spectroscopy of the ionized gas kinematics in galactic rings

abstract:
  The kinematics of galactic rings were studied with a scanning Fabry-Perot
interferometer mounted in the multi-mode focal reducer SCORPIO (Afanasiev &
Moiseev 2005) at the SAO RAS 6-m telescope. The analysis of the ionized gas
velocity fields allows us to understand the nature of the ring formation in
several galaxies. The different types of the rings in the presented objects
(resonanced, collisional, polar) were caused by the various sorts of
interactions: merging, head-on collisions.


title:
Merging as a key to reforming of disk and AGN triggering in Sy galaxy
  Mrk334

abstract:
  We have studied the kinematics of the ionized gas and stellar component in
Mrk334 using methods of panoramic (3D) spectroscopy. The observations were
performed at the prime focus of the SAO RAS 6-m telescope with the
integral-field spectrograph MPFS (Afanasiev et al. 2001) and with a scanning
Fabry-Perot interferometer (FPI), installed on the multimode device SCORPIO
(Afanasiev & Moiseev 2005). Based on these data, the monochromatic maps and
velocity fields in different emission lines of the ionized gas were
constructed. The diagnostic diagrams have been made based on the emission lines
ratios.


title: Controllable spin transport in ferromagnetic graphene junctions

abstract:
  We study spin transport in normal/ferromagnetic/normal graphene junctions
where a gate electrode is attached to the ferromagnetic graphene. We find that
due to the exchange field of the ferromagnetic graphene, spin current through
the junctions has an oscillatory behavior with respect to the chemical
potential in the ferromagnetic graphene, which can be tuned by the gate
voltage. Especially, we obtain a controllable spin current reversal by the gate
voltage. Our prediction of high controllability of spin transport in
ferromagnetic graphene junction may contribute to the development of the
spintronics.


title: Helicity Spectra and Dissipation

abstract:
  Both dissipation of helicity and it spectrum we are study on the basis of
asymptotic model. Introduction into model dependence of angle between turbulent
components vorticity and velocity on the governing parameters leads to the
spectra of helicity observed experimentally and obtained by DNS model
computations by various authors. At the same time, it settles the problem of
helicity dissipation divergence with growing Reynolds number.


title:
Einstein-Yang-Mills black hole solution in higher dimensions by the
  Wu-Yang Ansatz

abstract:
  By employing the higher dimensional version of the Wu-Yang Ansatz we obtain
black hole solutions in the spherically symmetric Einstein-Yang-Mills (EYM)
theory. Although these solutions were found recently by other means, our method
provides an alternative way in which one identifies the contribution from the
Yang-Mills (YM) charge. Our method has the advantage to be carried out
analytically as well. We discuss some interesting features of the black hole
solutions obtained.


title:
The Sloan Lens ACS Survey. VI: Discovery and analysis of a double
  Einstein ring

abstract:
  We report the discovery of two concentric Einstein rings around the
gravitational lens SDSSJ0946+1006, as part of the Sloan Lens ACS Survey. The
main lens is at redshift zl=0.222, while the inner ring (1) is at zs1=0.609 and
Einstein radius $Re_1=1.43\pm0.01"$. The wider image separation ($Re_2=2.07\pm
0.02"$) of the outer ring (2) implies that it is at higher redshift. Its
detection in the F814W filter implies zs2<6.9. The configuration can be well
described by a total density profile $\rho_{tot} ~ r^-g'$ with $g'=2.00\pm0.03$
and velocity dispersion $\sigma_{SIE}=287\pm5\kms$. [...] We consider whether
this configuration can be used to constrain cosmological parameters exploiting
angular distance ratios entering the lens equations. Constraints for
SDSSJ0946+1006, are uninteresting due to the sub-optimal lens and source
redshifts. We then consider the perturbing effect of the mass associated with
Ring 1 building a double lens plane compound lens model. This introduces minor
changes to the mass of the main lens and allows to estimate the mass of Ring 1
$(\sigma_{SIE,s1}=94\pm30\kms)$. We examine the prospects of doing cosmography
with a sample of 50 double lenses, expected from future space based surveys
such as DUNE or JDEM. Taking full account of the model uncertainties, such a
sample could be used to measure $\Omega_m$ and $w$ with 10% accuracy, for a
flat cosmology.


title: Compactification des vari\'et\'es de Deligne-Lusztig

abstract:
  We construct explicitly the normalisation of the
Bott-Samelson-Demazure-Hansen compactification of Deligne-Lusztig varieties
$X(w)$ in their covering $Y(w)$: we retrieve a result by Deligne-Lusztig about
the local monodromy around the divisors of the compactification.


title: Magic angles and cross-hatching instability in hydrogel fracture

abstract:
  The full 2D analysis of roughness profiles of fracture surfaces resulting
from quasi-static crack propagation in gelatin gels reveals an original
behavior characterized by (i) strong anisotropy with maximum roughness at
$V$-independent symmetry-preserving angles, (ii) a sub-critical instability
leading, below a critical velocity, to a cross-hatched regime due to straight
macrosteps drifting at the same magic angles and nucleated on crack-pinning
network inhomogeneities. Step height values are determined by the width of the
strain-hardened zone, governed by the elastic crack blunting characteristic of
soft solids with breaking stresses much larger that low strain moduli.


title: The Variation of Galaxy Morphological Type with the Shear of Environment

abstract:
  Recent N-body simulations have shown that the assembly history of galactic
halos depend on the density of large-scale environment. It implies that the
galaxy properties like age and size of bulge may also vary with the surrounding
large-scale structures, which are characterized by the tidal shear as well as
the density. By using a sample of 15,882 well-resolved nearby galaxies from the
Tully Catalog and the real space tidal field reconstructed from the 2Mass
Redshift Survey (2MRS), we investigate the dependence of galaxy morphological
type on the shear of large-scale environment where the galaxies are embedded.
We first calculate the large scale dimensionless overdensities (d) and the
large-scale ellipticities (e) of the regions where the Tully galaxies are
located and classify the Tully galaxies according to their morphological types
and create subsamples selected at similar value of d but span different ranges
in e. We calculate the mean ellipticity, <e>, averaged over each subsample and
find a signal of variation of <e> with galaxy morphological type: For the case
of 0.5<=d<=1.0, the ellipticals are found to be preferentially located in the
regions with low ellipticity. For the case of -0.3<=d<=0.1, the latest-type
spirals are found to be preferentially located in the regions with high
ellipticity. The null hypothesis that the mean ellipticities of the regions
where the ellipticals and the latest type spirals are located are same as the
global mean ellipticity averaged over all types is rejected at 3 sigma level
when -0.3<=d<=0.1. Yet, no signal of galaxy-shear correlation is found in the
highly overdense/underdense regions. The observed trend suggests that the
formation epochs of galactic halos might be a function not only of halo mass
and large-scale density but also of large-scale shear.


title:
From the ideal gas to an ideal glass: reversible path to random close
  packing

abstract:
  A reproducible RCP state is obtained by a well-defined rate process, which is
first-order in free volume, starting from an equilibrium thermodynamic state of
the hard-sphere fluid. The RCP state is also reproduced by a thermodynamic
pathway that inhibits the frequent production of small crystal nucleites which
can lead to heterogeneities at close packing. The simple-cubic single-occupancy
(SCSO) cell system, in which crystallization is de facto prohibited, provides a
reversible path all the way from the ideal gas to the ideal glass (RCP). By
such a route, unique characterization of RCP becomes possible.


title:
On differences between fractional and integer order differential
  equations for dynamical games

abstract:
  We argue that fractional order (FO) differential equations are more suitable
to model complex adaptive systems (CAS). Hence they are applied in replicator
equations for non-cooperative game. Rock-Scissors-Paper game is discussed. It
is known that its integer order model does not have a stable equilibrium. Its
fractional order model is shown to have a locally asymptotically stable
internal solution. A FO asymmetric game is shown to have a locally
asymptotically stable internal solution. This is not the case for its integer
order counterpart.


title:
Superstring in the plane-wave background with RR flux as a conformal
  field theory

abstract:
  We study the type IIB superstring in the plane-wave background with
Ramond-Ramond flux and formulate it as an exact conformal field theory in
operator formalism. One of the characteristic features of the superstring in a
consistent background with RR flux, such as the AdS5xS5 and its plane-wave
limit, is that the left- and the right-moving degrees of freedom on the
worldsheet are inherently coupled. In the plane-wave case, it is manifested in
the well-known fact that the Green-Schwarz formulation of the theory reduces to
that of free massive bosons and fermions in the light-cone gauge. This raises
the obvious question as to how this feature is reconciled with the underlying
conformal symmetry of the string theory. By adopting the semi-light-cone
conformal gauge, we will show that, despite the existence of such non-linear
left-right couplings, one can construct two independent sets of quantum
Virasoro operators in terms of fields obeying the free-field commutation
relations. Furthermore, we demonstrate that the BRST cohomology analysis
reproduces the physical spectrum obtained in the light-cone gauge.


title: 5D-Black Hole Solution in Einstein-Yang-Mills-Gauss-Bonnet Theory

abstract:
  By adopting the 5D version of the Wu-Yang Ansatz we present in closed form a
black hole solution in the Einstein-Yang-Mills-Gauss-Bonnet (EYMGB) theory. In
the EYM limit, we recover the 5D black hole solution already known.


title:
Characteristics of the asymmetric simple exclusion process in the
  presence of quenched spatial disorder

abstract:
  We investigate the effect of quenched spatial disordered hopping rates on the
characteristics of the asymmetric simple exclusion process (ASEP) with open
boundaries both numerically and by extensive simulations. Disorder averages of
the bulk density and current are obtained in terms of various input and output
rates. We study the binary and uniform distributions of disorder. It is
verified that the effect of spatial inhomogeneity is generically to enlarge the
size of the maximal current phase. This is in accordance with the mean field
results obtained by Harris and Stinchcombe. Furthermore, we obtain the
dependence of the current and the bulk density on the characteristics of the
disorder distribution function. It is shown that the impact of disorder
crucially depends on the particle input and out rates. In some situations,
disorder can constructively enhance the current.


title: The Evolution of Black Hole Mass and Spin in Active Galactic Nuclei

abstract:
  We argue that supermassive black hole growth in AGN occurs via sequences of
randomly--oriented accretion discs with angular momentum limited by
self--gravity. These stably co-- or counter--align with the black hole spin
with almost equal frequency. Accretion from these discs very rapidly adjusts
the hole's spin parameter to average values $\bar a \sim 0.1-0.3$ (the precise
range depending slightly on the disc vertical viscosity coefficient $\alpha_2$)
from any initial conditions, but with significant fluctuations ($\Delta a\sim
\pm 0.2$) about these. We conclude (a) AGN black holes should on average spin
moderately, with the mean value $\bar a$ decreasing slowly as the mass
increases; (b) SMBH coalescences leave little long--term effect on $\bar a$;
(c) SMBH coalescence products in general have modest recoil velocities, so that
there is little likelihood of their being ejected from the host galaxy; (d)
black holes can grow even from stellar masses to $\sim 5\times 10^9 \msun$ at
high redshift $z\sim 6$; (e) jets produced in successive accretion episodes can
have similar directions, but after several episodes the jet direction deviates
significantly. Rare examples of massive holes with larger spin parameters could
result from prograde coalescences with SMBH of similar mass, and are most
likely to be found in giant ellipticals. We compare these results with
observation.
  (abridged)


title: Dynamics of dark energy with a coupling to dark matter

abstract:
  Dark energy and dark matter are the dominant sources in the evolution of the
late universe. They are currently only indirectly detected via their
gravitational effects, and there could be a coupling between them without
violating observational constraints. We investigate the background dynamics
when dark energy is modelled as exponential quintessence, and is coupled to
dark matter via simple models of energy exchange. We introduce a new form of
dark sector coupling, which leads to a more complicated dynamical phase space
and has a better physical motivation than previous mathematically similar
couplings.


title:
Center-Symmetric Effective Theory for High-Temperature SU(2) Yang-Mills
  Theory

abstract:
  We construct and study a dimensionally reduced effective theory for
high-temperature SU(2) Yang-Mills theory that respects all the symmetries of
the underlying theory. Our main motivation is to study, whether the correct
treatment of the center symmetry can help extend the applicability of the
dimensional reduction procedure towards the confinement transition. After
performing perturbative matching to the full theory at asymptotically high
temperatures, we map the phase diagram of the effective theory using
non-perturbative lattice simulations. We find that at lower temperature the
theory undergoes a second order confining phase transition, in complete analogy
with the full theory, which is a direct consequence of having incorporated the
center symmetry.


title: Semifluxons in Superconductivity and Cold Atomic Gases

abstract:
  Josephson junctions and junction arrays are well studied devices in
superconductivity. With external magnetic fields one can modulate the phase in
a long junction and create traveling, solitonic waves of magnetic flux, called
fluxons. Today, it is also possible to device two different types of junctions:
depending on the sign of the critical current density, they are called 0- or
pi-junction. In turn, a 0-pi junction is formed by joining two of such
junctions. As a result, one obtains a pinned Josephson vortex of fractional
magnetic flux, at the 0-pi boundary. Here, we analyze this arrangement of
superconducting junctions in the context of an atomic bosonic quantum gas,
where two-state atoms in a double well trap are coupled in an analogous
fashion. There, an all-optical 0-pi Josephson junction is created by the phase
of a complex valued Rabi-frequency and we a derive a discrete four-mode model
for this situation, which qualitatively resembles a semifluxon.


title: Basic differential geometry as a sequence of interesting problems

abstract:
  This book is expository and is in Russian (sample English translation of two
pages is given). It is shown how in the course of solution of interesting
geometric problems (close to applications) naturally appear different notions
of curvature, which distinguish given geometry from the 'ordinary' one. Direct
elementary definitions of these notions are presented. The book is accessible
for students familiar with analysis of several variables, and could be an
interesting easy reading for professional mathematicians. The material is
presented as a sequence of problems, which is peculiar not only to Zen
monasteries but also to serious mathematical education.


title: Bounds and asymptotic minimal growth for Gorenstein Hilbert functions

abstract:
  We determine new bounds on the entries of Gorenstein Hilbert functions, both
in any fixed codimension and asymptotically.
  Our first main theorem is a lower bound for the degree $i+1$ entry of a
Gorenstein $h$-vector, in terms of its entry in degree $i$. This result carries
interesting applications concerning unimodality: indeed, an important
consequence is that, given $r$ and $i$, all Gorenstein $h$-vectors of
codimension $r$ and socle degree $e\geq e_0=e_0(r,i)$ (this function being
explicitly computed) are unimodal up to degree $i+1$. This immediately gives a
new proof of a theorem of Stanley that all Gorenstein $h$-vectors in
codimension three are unimodal.
  Our second main theorem is an asymptotic formula for the least value that the
$i$-th entry of a Gorenstein $h$-vector may assume, in terms of codimension,
$r$, and socle degree, $e$. This theorem broadly generalizes a recent result of
ours, where we proved a conjecture of Stanley predicting that asymptotic value
in the specific case $e=4$ and $i=2$, as well as a result of Kleinschmidt which
concerned the logarithmic asymptotic behavior in degree $i= \lfloor \frac{e}{2}
\rfloor $.


title:
Coherent Delocalization of Atomic Wave Packets in Driven Lattice
  Potentials

abstract:
  Atomic wave packets loaded into a phase-modulated vertical optical-lattice
potential exhibit a coherent delocalization dynamics arising from intraband
transitions among Wannier-Stark levels. Wannier-Stark intraband transitions are
here observed by monitoring the in situ wave-packet extent. By varying the
modulation frequency, we find resonances at integer multiples of the Bloch
frequency. The resonances show a Fourier-limited width for interrogation times
up to 2 s. This can also be used to determine the gravity acceleration with ppm
resolution.


title: Classical and quantum constraints in spin physics

abstract:
  Constraints on spin observables coming from discrete symmetries such as P, C,
T and identical particles may be divided in two types: 1) classical ones, which
insure the invariance of the cross sections under the symmetry operation; 2)
non-classical ones, which can only be obtained at the level of amplitudes.
Similarly, positivity constraints can be divided into classical and
non-classical constraints. The former insure the positivity of the cross
section for arbitrary individual polarisations of the external particles, the
latter extend this requirement to the case of entangled external spins. The
domain of classical positivity is shown to be dual to the domain of
separability


title: Preliminary analysis of a recent experiment by F. A. Bovino

abstract:
  An analysis is made of the results of a recent polarization correlation
experiment by Bovino (unpublished) where about 60,000 data have been obtained.
I assume that the state of the photon pairs produced in the source (a
non-linear crystal) are in a (slightly)non-maximally entangled state and the
most relevant non-idealities of the set-up are taken into account. A comparison
is made between the predictions of quantum mechanics and a simple family of
local hidden varaibles models with the result that the former is violated by
more than 4 standard deviations whislt the data are compatible with the family
of local models.


title: Taking a shower in Youth Hostels: risks and delights of heterogeneity

abstract:
  Tuning one's shower in some hotels may turn into a challenging coordination
game with imperfect information. The temperature sensitivity increases with the
number of agents, making the problem possibly unlearnable. Because there is in
practice a finite number of possible tap positions, identical agents are
unlikely to reach even approximately their favorite water temperature. We show
that a population of agents with homogeneous strategies is evolutionary
unstable, which gives insights into the emergence of heterogeneity, the latter
being tempting but risky.


title: Massive stars, globular clusters and elliptical galaxies

abstract:
  Globular clusters as $\omega$ Cen and NGC 2808 appear to have a population of
very He-rich stars. From a theoretical point of view, one expects the presence
of He-rich stars in all globular clusters showing an oxygen-sodium (O-Na)
anticorrelation. In this paper, we briefly recall how fast rotating massive
stars could be the main source of the material from which He-rich stars have
formed. We speculate that the UV-upturn phenomenon observed in all elliptical
galaxies might be due to He-rich stars. If this hypothesis is correct then fast
rotating massive stars may have played in the early evolutionary phases of
these systems a similar role as the one they played in the nascent globular
clusters.


title: On the Refractive Index of Ageing Dispersions of Laponite

abstract:
  Aqueous dispersion of Laponite at low ionic concentration is of interest
since it undergoes structural evolution with respect to time, which is usually
termed as ageing. In this work we study the refractive index behavior as a
function of ageing time, concentration and temperature. We observed that the
extended Lorenz-Lorentz equation fitted the refractive index dependence on
concentration and temperature very well. The refractive index did not show any
dependence on ageing time. However, the dependence of refractive index on
concentration showed a marked change as the system underwent transition from an
isotropic to a biphasic state. The slope of the refractive index-density data
is remarkably close to that of water at all Laponite concentrations. In the
context of transport phenomena, optical measurements such as interferometry can
exploit the water-like behavior of Laponite dispersions.


title: Measurable Concurrence of Mixed States

abstract:
  We show that bipartite concurrence for rank-2 mixed states of qubits is
written by an observable which can be exactly and directly measurable in
experiment by local projective measurements, provided that four copies of the
composite quantum system are available. In addition, for a tripartite quantum
pure state of qubits, the 3-tangle is also shown to be measurable only by
projective measurements on the reduced density matrices of a pair of qubits
conditioned on four copies of the state.


title:
A calendar Quipu of the early 17th century and its relationship with the
  Inca astronomy

abstract:
  The so-called Miccinelli documents are a set of documents which were written
by Jesuit scholars in Peru within the first half of the 17th century. Among
such documents, one contains the depiction of a Quipu, that is, a device made
out of cords of different nature and colors which, with the help of nodes, were
used by the Incas for storing data. This Quipu is claimed by the author, Blas
Valera, to be a reproduction of the Inca calendar of the year of the Spanish
conquest. We give here a complete analysis of the astronomical events occurred
in Cusco in that year, showing that they actually correspond closely to the
data reported in the Quipu, and compare the calendrical information - such as
the names and the rituals of each month - with those given by other documents,
especially the Nuova Coronica by G. Poma de Ayala. The possible relevance of
the document for the knowledge of the original Inca lore of the sky is
discussed in details.


title: Probing the centre of the large circumstellar disc in M17

abstract:
  We investigated the nature of the hitherto unresolved elliptical infrared
emission in the centre of the ~20000 AU disc silhouette in M 17. We combined
high-resolution JHKsL'M' band imaging carried out with NAOS/CONICA at the VLT
with [Fe II] narrow band imaging using SOFI at the NTT. The analysis is
supported by Spitzer/GLIMPSE archival data and by already published SINFONI/VLT
Integral Field Spectroscopy data. For the first time, we resolve the elongated
central infrared emission into a point-source and a jet-like feature that
extends to the northeast in the opposite direction of the recently discovered
collimated H2 jet. They are both orientated almost perpendicular to the disc
plane. In addition, our images reveal a curved southwestern emission nebula
whose morphology resembles that of the previously detected northeastern one.
Both nebulae are located at a distance of 1500 AU from the disc centre. We
describe the infrared point-source in terms of a protostar that is embedded in
circumstellar material producing a visual extinction of 60 <= Av <= 82. The
observed Ks band magnitude is equivalent to a stellar mass range of 2.8 Msun <=
Mstar <= 8 Msun adopting conversions for a main-sequence star. Altogether, we
suggest that the large M 17 accretion disc is forming an intermediate to
high-mass protostar. Part of the accreted material is expelled through a
symmetric bipolar jet/outflow.