title: The classification of algebras of level one

abstract:
  In the present paper we obtain the list of algebras, up to isomorphism, such
that closure of any complex finite-dimensional algebra contains one of the
algebra of the given list.


title: The 130 GeV gamma-ray line and Sommerfeld enhancements

abstract:
  Recently, possible indications of line spectral features in the Fermi-LAT
photon spectrum towards the galactic center have been reported. If the distinct
line features arise from dark matter (DM) annihilation into $\gamma X
(X=\gamma, Z^{0} or h^{0})$, the corresponding annihilation cross-section is
unnaturally large for typical loop-induced radiative processes. On the other
hand, it is still too small to be responsible for the observed DM relic
density. We show that the mechanism of Sommerfeld enhancement with scalar
force-carrier can provide a simple solution to these puzzles. The possibly
large Sommerfeld enhancement of the cross-section for s-wave DM annihilation
can significantly reduce the required effective couplings between DM and
charged particles in typical loop diagrams. The DM particles necessarily
annihilate into scalar force-carriers through tree-level p-wave process, which
can dominate the total DM annihilation cross-section at freeze out, resulting
in the correct thermal relic density, but has subdominant contributions to the
DM annihilation today due to velocity suppression. We perform detailed analysis
on the effects of p-wave Sommerfeld enhancement on freeze out. The results show
that with the constraints from the thermal relic density, the required
effective couplings can be reduced by an order of magnitude.


title: Reconstructing the Properties of Dark Energy using Standard Sirens

abstract:
  Future space-based gravity wave experiments such as the Big Bang Observatory
(BBO), with their excellent projected, one sigma angular resolution, will
measure the luminosity distance to a large number of gravity wave (GW) sources
to high precision, and the redshift of the single galaxies in the narrow solid
angles towards the sources will provide the redshifts of the gravity wave
sources. One sigma BBO beams contain the actual source only in 68 per cent
cases; the beams that do not contain the source may contain a spurious single
galaxy, leading to misidentification. To increase the probability of the source
falling within the beam, larger beams have to be considered, decreasing the
chances of finding single galaxies in the beams. Saini, Sethi and Sahni (2010)
argued, largely analytically, that identifying even a small number of GW source
galaxies furnishes a rough distance-redshift relation, which could be used to
further resolve sources that have multiple objects in the angular beam. In this
work we further develop this idea by introducing a self-calibrating iterative
scheme which works in conjunction with Monte-Carlo simulations to determine the
luminosity distance to GW sources with progressively greater accuracy. This
iterative scheme allows one to determine the equation of state of dark energy
to within an accuracy of a few percent for a gravity wave experiment possessing
a beam width an order of magnitude larger than BBO (and therefore having a far
poorer angular resolution). This is achieved with no prior information about
the nature of dark energy from other data sets such as SN Ia, BAO, CMB etc.


title:
Trace formulae and singular values of resolvent power differences of
  self-adjoint elliptic operators

abstract:
  In this note self-adjoint realizations of second order elliptic differential
expressions with non-local Robin boundary conditions on a domain
$\Omega\subset\dR^n$ with smooth compact boundary are studied. A Schatten--von
Neumann type estimate for the singular values of the difference of the $m$th
powers of the resolvents of two Robin realizations is obtained, and for
$m>\tfrac{n}{2}-1$ it is shown that the resolvent power difference is a trace
class operator. The estimates are slightly stronger than the classical singular
value estimates by M. Sh. Birman where one of the Robin realizations is
replaced by the Dirichlet operator. In both cases trace formulae are proved, in
which the trace of the resolvent power differences in $L^2(\Omega)$ is written
in terms of the trace of derivatives of Neumann-to-Dirichlet and
Robin-to-Neumann maps on the boundary space $L^2(\partial\Omega)$.


title:
The D/H ratio in the atmospheres of Uranus and Neptune from Herschel
  PACS observations

abstract:
  Herschel-PACS measurements of the rotational R(0) and R(1) HD lines in the
atmospheres of Uranus and Neptune are analyzed in order to derive a D/H ratio
with improved precision for both planets. The derivation of the D/H ratio
includes also previous measurements of the R(2) line by the Short Wavelength
Spectrometer on board the Infrared Space Observatory (ISO). The available
spectroscopic line information of the three rotational transitions is discussed
and applied in the radiative transfer calculations. The best simultaneous fit
of all three lines requires only a minor departure from the Spitzer temperature
profile of Uranus and a departure limited to 2K from the Voyager temperature
profile of Neptune (both around the tropopause). The resulting and remarkably
similar D/H ratios for Uranus and Neptune are found to be
(4.4$\pm$0.4)$\times10^{-5}$ and (4.1$\pm$0.4)$\times10^{-5}$ respectively.
Although the deuterium enrichment in both atmospheres compared to the
protosolar value is confirmed, it is found to be lower compared to previous
analysis. Using the interior models of Podolak et al. (1995), Helled et al.
(2011) and Nettelmann et al. (2013), and assuming that complete mixing of the
atmosphere and interior occured during the planets history, we derive a D/H in
protoplanetary ices between (5.75--7.0)$\times10^{-5}$ for Uranus and between
(5.1--7.7)$\times10^{-5}$ for Neptune. Conversely, adopting a cometary D/H for
the protoplanetary ices between (15-30)$\times10^{-5}$, we constrain the
interior models of both planets to have an ice mass fraction of 14-32%, i.e.
that the two planets are rock-dominated.


title:
Association between quality of clinical practice guidelines and
  citations given to their references

abstract:
  It has been suggested that bibliometric analysis of different document types
may reveal new aspects of research performance. In medical research a number of
study types play different roles in the research process and it has been shown,
that the evidence-level of study types is associated with varying citation
rates. This study focuses on clinical practice guidelines, which are supposed
to gather the highest evidence on a given topic to give the best possible
recommendation for practitioners. The quality of clinical practice guidelines,
measured using the AGREE score, is compared to the citations given to the
references used in these guidelines, as it is hypothesised, that better
guidelines are based on higher cited references. AGREE scores are gathered from
reviews of clinical practice guidelines on a number of diseases and treatments.
Their references are collected from Web of Science and citation counts are
normalised using the item-oriented z-score and the PPtop-10% indicators. A
positive correlation between both citation indicators and the AGREE score of
clinical practice guidelines is found. Some potential confounding factors are
identified. While confounding cannot be excluded, results indicate low
likelihood for the identified confounders. The results provide a new
perspective to and application of citation analysis.


title:
The Metallicity Dependence of the Minimum Mass for Core-Collapse
  Supernovae

abstract:
  Understanding the progenitors of core collapse supernovae and their
population statistics is a key ingredient for many current studies in astronomy
but as yet this remains elusive. Using the MESA stellar evolution code we study
the dependence of the lower mass limit for making core collapse supernovae
(SNe) as function of initial stellar metallicity. We find that this mass limit
is smallest at approximately [Z] = -2 with a value of ~ 8.3 Msun. At [Z] = 0
the limit is ~ 9.5 Msun and continues to rise with higher metallicity. As a
consequence, for a fixed initial mass function the supernova rate may be 20% to
25% higher at [Z] = -2. This affects the association of observed SN rates as a
probe for the cosmological star formation rate, rate predictions for supernova
surveys, and population synthesis studies.


title: Factorization in high energy nucleus-nucleus collisions

abstract:
  In this talk, we discuss the factorization of the logarithms of energy in the
Color Glass Condensate framework.


title: Powerful relativistic jets in narrow-line Seyfert 1 galaxies

abstract:
  The recent detection of high-energy gamma rays from Narrow-Line Seyfert 1
Galaxies has confirmed that also this type of active galactic nuclei can
generate powerful relativistic jets. I outline the evolution of the knowledge
in this research field and the implications on the unification of relativistic
jets at all scales.


title: Topological aspects of an exactly solvable spin chain

abstract:
  We analyse a spin-1/2 chain with two-spin interactions which shown to exactly
solvable by Lieb, Schultz and Mattis. We show that the model can be viewed as a
generalised Kitaev model that is analytically solvable for all defect sectors.
We present an alternate proof that the defect free sector is the ground state,
which is valid for a larger parameter range. We show that the defect sectors
have degenerate ground states corresponding to unpaired Majorana fermion modes
and that the degeneracy is topologically protected against disorder in the
spin-spin couplings. The unpaired Majorana fermions can be manipulated by
tuning the model parameters and can hence be used for topological quantum
computation.


title:
Neutron Transverse-Momentum Distributions and Polarized 3He within
  Light-Front Hamiltonian Dynamics

abstract:
  The possibility to extract the quark transverse-momentum distributions in the
neutron from semi-inclusive deep inelastic electron scattering off polarized
3He is illustrated through an impulse approximation analysis in the Bjorken
limit. The generalization of the analysis at finite momentum transfers in a
Poincare' covariant framework is outlined. The definition of the light-front
spin-dependent spectral function of a J=1/2 system allows us to show that
within the light-front dynamics only three of the six leading twist T-even
transverse-momentum distributions are independent.


title:
Phonon-Magnon coupling in CoF$_2$ investigated by time-of-flight neutron
  spectroscopy

abstract:
  We report the results of inelastic neutron scattering investigation on the
model antiferromagnet CoF$_2$ by time-of-flight neutron spectroscopy. We
measured the details of the scattering function $S(Q,\omega)$ as a function of
temperature with two different incident neutron wavelengths. The temperature
and Q dependence of the measured scattering function suggests the presence of
magnon-phonon coupling in almost all branches. The present results are in
agreement with the strong magnetoelastic effects observed previously.


title:
Optimal conditions for magnetization reversal of nanocluster assemblies
  with random properties

abstract:
  Magnetization dynamics in the system of magnetic nanoclusters with randomly
distributed properties are studied by means of computer simulations. The main
attention is paid to the possibility of coherent magnetization reversal from a
strongly nonequilibrium state with a mean cluster magnetization directed
opposite to an external magnetic field. Magnetic nanoclusters are known to be
characterized by large magnetic anisotropy and strong dipole interactions. It
is also impossible to produce a number of nanoclusters with identical
properties. As a result, any realistic system of nanoclusters is composed of
the clusters with randomly varying anisotropies, effective spins, and dipole
interactions. Despite this randomness, it is possible to find conditions when
the cluster spins move coherently and display fast magnetization reversal due
to the feedback action of resonator. By analyzing the influence of different
cluster parameters, we find their optimal values providing fast magnetization
reversal.


title:
Nucleon-Nucleon Scattering Parameters in the Limit of SU(3) Flavor
  Symmetry

abstract:
  The scattering lengths and effective ranges that describe low-energy
nucleon-nucleon scattering are calculated in the limit of SU(3)-flavor symmetry
at the physical strange-quark mass with Lattice Quantum Chromodynamics. The
calculations are performed with an isotropic clover discretization of the quark
action in three volumes with spatial extents of L \sim 3.4 fm, 4.5fm and 6.7
fm, and with a lattice spacing of b \sim 0.145 fm. With determinations of the
energies of the two-nucleon systems (both of which contain bound states at
these up and down quark masses) at rest and moving in the lattice volume,
Luscher's method is used to determine the low-energy phase shifts in each
channel, from which the scattering length and effective range are obtained. The
scattering parameters, in the 1S0 channel are found to be m_pi a^(1S0) =
9.50^{+0.78}_{-0.69}^{+1.10}_{-0.80} and m_pi r^(1S0) =
{4.61^{+0.29}_{-0.31}^{+0.24}_{-0.26}, and in the 3S1 channel are m_pi a^(3S1)
= 7.45^{+0.57}_{-0.53}^{+0.71}_{-0.49} and m_pi r^(3S1) =
3.71^{+0.28}_{-0.31}^{+0.28}_{-0.35}. These values are consistent with the
two-nucleon system exhibiting Wigner's supermultiplet symmetry, which becomes
exact in the limit of large-N_c. In both spin channels, the phase shifts change
sign at higher momentum, near the start of the t-channel cut, indicating that
the nuclear interactions have a repulsive core even at the SU(3)-symmetric
point.


title: Lightcurves of 32 Large Transneptunian Objects

abstract:
  We present observations of 32 primarily bright, newly discovered
Transneptunian objects observable from the Southern Hemisphere during 39 nights
of observation with the 2.5-m telescope at Las Campanas Observatory. Our
dataset includes objects in all dynamical classes, but is weighted towards
Scattered objects. We find 15 objects for which we can fit periods and
amplitudes to the data, and place lightcurve amplitude upper limits on the
other 17 objects. Combining our sample with the larger sample in the
literature, we find a 3-sigma correlation between lightcurve amplitude and
absolute magnitude with fainter objects having larger lightcurve amplitudes. We
looked for correlations between lightcurve and individual orbital properties,
but did not find any statistically significant results. However, if we consider
lightcurve properties with respect to dynamical classification, we find
statistically different distributions between the Classical-Scattered and
Classical-Resonant populations, respectively, with the Classical objects having
larger amplitude lightcurves. The properties of binary lightcurves are largely
consistent with the greater population except in the case of tidally locked
systems. All the Haumea family objects measured so far have measurable
amplitudes and rotation periods le 10 hr suggesting that they are not
significantly different from the larger TNO population. We expect multiple
factors are influencing object rotations: object size dominates lightcurve
properties except in the case of tidal, or proportionally large collisional
interactions with other objects, the influence of the latter being different
for each sub-population. We also present phase curves and colors for some
objects; our values are not significantly different from those presented in the
literature for other samples.


title: The Einstein-scalar field constraint system in the positive case

abstract:
  We prove the existence of solutions to the conformal Einstein-scalar
constraint system of equations for closed compact Riemannian manifolds in the
positive case. Our results apply to the vacuum case with positive cosmological
constant and to the massive Klein-Gordon setting.


title:
Video Tester -- A multiple-metric framework for video quality assessment
  over IP networks

abstract:
  This paper presents an extensible and reusable framework which addresses the
problem of video quality assessment over IP networks. The proposed tool
(referred to as Video-Tester) supports raw uncompressed video encoding and
decoding. It also includes different video over IP transmission methods (i.e.:
RTP over UDP unicast and multicast, as well as RTP over TCP). In addition, it
is furnished with a rich set of offline analysis capabilities. Video-Tester
analysis includes QoS and bitstream parameters estimation (i.e.: bandwidth,
packet inter-arrival time, jitter and loss rate, as well as GOP size and
I-frame loss rate). Our design facilitates the integration of virtually any
existing video quality metric thanks to the adopted Python-based modular
approach. Video-Tester currently provides PSNR, SSIM, ITU-T G.1070 video
quality metric, DIV and PSNR-based MOS estimations. In order to promote its use
and extension, Video-Tester is open and publicly available.


title: Size effects in dislocation depinning models for plastic yield

abstract:
  Typically, the plastic yield stress of a sample is determined from a
stress-strain curve by defining a yield strain and reading off the stress
required to attain it. However, it is not a priori clear that yield strengths
of microscale samples measured this way should display the correct finite size
scaling. Here we study plastic yield as a depinning transition of a 1+1
dimensional interface, and consider how finite size effects depend on the
choice of yield strain, as well as the presence of hardening and the strength
of elastic coupling. Our results indicate that in sufficiently large systems,
the choice of yield strain is unimportant, but in smaller systems one must take
care to avoid spurious effects.


title: Obstacle problem for semilinear parabolic equations with measure data

abstract:
  We consider the obstacle problem with two irregular reflecting barriers for
the Cauchy-Dirichlet problem for semilinear parabolic equations with measure
data. We prove the existence and uniqueness of renormalized solutions of the
problem and well as results on approximation of the solutions by the
penaliztion method. In the proofs we use probabilistic methods of the theory of
Markov processes and the theory of backward stochastic differential equations.


title:
Weak field approximation in a model of de Sitter gravity: Schwarzschild
  solutions and galactic rotation curves

abstract:
  Weak field approximate solutions in the Lambda-->0 limit of a model of de
Sitter gravity have been presented in the static and spherically symmetric
case. Although the model looks different from general relativity, among those
solutions, there still exist the weak Schwarzschild fields with the smooth
connection to regular internal solutions obeying the Newtonian gravitational
law. The existence of such solutions would determine the value of the coupling
constant, which is different from that of the previous literature. Moreover,
there also exist solutions that could deduce the galactic rotation curves
without invoking dark matter.


title:
The advanced setup for synthesis of composite long-length
  superconducting tape of Nb3Sn

abstract:
  The description of design of advanced technological setup for the synthesis
of composite long-length superconducting tape on the basis of Nb3Sn is
presented. The design of setup has allowed us to produce the Nb3Sn tape with
the record magnitudes of density of critical current Jc in the magnetic fields
H of above 10 T (H > 10 T). The high current density conductivity property is
reached as a result of both the optimization of technological process of the
Nb3Sn tape synthesis and the increase of thickness of superconductor layer,
which is characterized by the homogeneous physical properties.


title: Superfast solution of Toeplitz systems based on syzygy reduction

abstract:
  We present a new superfast algorithm for solving Toeplitz systems. This
algorithm is based on a relation between the solution of such problems and
syzygies of polynomials or moving lines. We show an explicit connection between
the generators of a Toeplitz matrix and the generators of the corresponding
module of syzygies. We show that this module is generated by two elements and
the solution of a Toeplitz system T u=g can be reinterpreted as the remainder
of a vector depending on g, by these two generators. We obtain these generators
and this remainder with computational complexity O(n log^2 n) for a Toeplitz
matrix of size nxn.


title: Noncommutative Valdivia compacta

abstract:
  We prove some generalizations of results concerning Valdivia compact spaces
(equivalently spaces with a commutative retractional skeleton) to the spaces
with a retractional skeleton (not necessarily commutative). Namely, we show
that the dual unit ball of a Banach space is Corson provided the dual unit ball
of every equivalent norm has a retractional skeleton. Another result to be
mentioned is the following. Having a compact space K, we show that K is Corson
if and only if every continuous image of K has a retractional skeleton.


title: Discovery of a Probable SX Phoenicis Star in M107 (NGC 6171)

abstract:
  Using V images taken in May and June 2012 with the SARA Consortium's
0.9-meter telescope located at Kitt Peak National Observatory, we searched for
variable stars in the globular cluster M107 (NGC 6171). The search was
accomplished using the ISIS v2.2 image subtraction software. We refined the
positions of the previously known variables and confirmed the 21 RR Lyrae
variables from Clement's Catalog of Variable Stars in Globular Clusters
(Clement et al. 2001). We also discovered a previously unknown variable which
is likely an SX Phoenicis star. For this SX Phoenicis star we measured a
fundamental pulsation frequency 19.0122/day (P=0.05257 days) and a mean
amplitude of 0.046 magnitudes in the V band. This variable had an average
V-band magnitude of 17.72, nearly 2 magnitudes dimmer than the horizontal
branch of M107, typical of SX Phoenicis stars and blue stragglers lying just
beyond the main sequence turn-off in globular clusters.


title: Avalanches, Breathers and Flow Reversal in a Continuous Lorenz-96 Model

abstract:
  For the discrete model suggested by Lorenz in 1996 a one-dimensional long
wave approximation with nonlinear excitation and diffusion is derived. The
model is energy conserving but non-Hamiltonian. In a low order truncation weak
external forcing of the zonal mean flow induces avalanche-like breather
solutions which cause reversal of the mean flow by a wave-mean flow
interaction. The mechanism is an outburst-recharge process similar to
avalanches in a sand pile model.


title: A model of Poissonian interactions and detection of dependence

abstract:
  This paper proposes a model of interactions between two point processes,
ruled by a reproduction function h, which is considered as the intensity of a
Poisson process. In particular, we focus on the context of neurosciences to
detect possible interactions in the cerebral activity associated with two
neurons. To provide a mathematical answer to this specific problem of
neurobiologists, we address so the question of testing the nullity of the
intensity h. We construct a multiple testing procedure obtained by the
aggregation of single tests based on a wavelet thresholding method. This test
has good theoretical properties: it is possible to guarantee the level but also
the power under some assumptions and its uniform separation rate over weak
Besov bodies is adaptive minimax. Then, some simulations are provided, showing
the good practical behavior of our testing procedure.


title:
Spectroscopy of $^{26}$F to probe proton-neutron forces close to the
  drip line

abstract:
  A long-lived $J^{\pi}=4_1^+$ isomer, $T_{1/2}=2.2(1)$ms, has been discovered
at 643.4(1) keV in the weakly-bound $^{26}_{9}$F nucleus. It was populated at
GANIL in the fragmentation of a $^{36}$S beam. It decays by an internal
transition to the $J^{\pi}=1_1^+$ ground state (82(14)%), by $\beta$-decay to
$^{26}$Ne, or beta-delayed neutron emission to $^{25}$Ne. From the beta-decay
studies of the $J^{\pi}=1_1^+$ and $J^{\pi}=4_1^+$ states, new excited states
have been discovered in $^{25,26}$Ne. Gathering the measured binding energies
of the $J^{\pi}=1_1^+-4_1^+$ multiplet in $^{26}_{9}$F, we find that the
proton-neutron $\pi 0d_{5/2} \nu 0d_{3/2}$ effective force used in shell-model
calculations should be reduced to properly account for the weak binding of
$^{26}_{9}$F. Microscopic coupled cluster theory calculations using
interactions derived from chiral effective field theory are in very good
agreement with the energy of the low-lying $1_1^+,2_1^+,4_1^+$ states in
$^{26}$F. Including three-body forces and coupling to the continuum effects
improve the agreement between experiment and theory as compared to the use of
two-body forces only.


title: A simple and fast algorithm for computing exponentials of power series

abstract:
  As was initially shown by Brent, exponentials of truncated power series can
be computed using a constant number of polynomial multiplications. This note
gives a relatively simple algorithm with a low constant factor.


title:
Translation-invariant bipolarons and the problem of high-temperature
  superconductivity

abstract:
  It is shown that the bipolaron ground state is described by a delocalized
wave function. For a two-parameter wave function, the lowest variation estimate
of the ground state energy in the strong coupling limit is found to be $E=-
0,414125 \alpha ^2$. This is much lower than that derived with the use of the
localized bipolaron wave function. The results obtained testify to the
possibility of a bipolaron mechanism of high-temperature superconductivity.


title:
Features of coal dust dynamics at action of differently oriented forces
  in granular filtering medium

abstract:
  The process of the coal dust particles transportation and structurization in
the experimental horizontal model of air filter with the cylindrical coal
adsorbent granules as in the iodine air filter at the nuclear power plant is
researched. In the investigated case the vector of carrying away force of air
flow and the vector of gravitation force are mutually perpendicular, and the
scattering of the dust particles on the granules occurs in the normal
directions. It is found that the phenomenon of non controlled spontaneous sharp
increase of aerodynamic resistance in the iodine air filter under the big
integral volumes of filtered air and the big masses of introduced coal dust
particles is not observed at the described experimental conditions in
distinction from the case of the parallel orientation of this forces as in the
vertical iodine air filters at the nuclear power plant. The quantitative
measurements of the main parameters of the process of the dust masses
transportation and structurization are made on a developed experimental model
of the iodine air filter with the cylindrical coal adsorbent granules.


title:
Relativistic mean field study of 'islands of inversion' in neutron rich
  Z = 17 - 23, 37 - 40 and 60 - 64 nuclei

abstract:
  We study the extremely neutron-rich nuclei for $Z = 17 - 23$, $37 - 40$ and
$60 - 64$ regions of the periodic table by using axially deformed relativistic
mean field formalism with NL3* parametrization. Based on the analysis of
binding energy, two neutron separation energy, quadrupole deformation and root
mean square radii, we emphasized the speciality of these considered regions
which are recently predicted islands of inversion.


title:
Testing the broad applicability of the PBEint GGA functional and its
  one-parameter hybrid form

abstract:
  We review the performance of the PBEint GGA functional (Phys. Rev. B 2010,
82, 113104) recently proposed to improve the description of hybrid interfaces,
and we introduce its one-parameter hybrid form (hPBEint). We consider different
well established benchmarks for energetic and structural properties of
molecular and solid-state systems as well as model systems and newly developed
benchmark sets for dipole moments and metal-molecule interactions. We find that
PBEint and hPBEint (with 16.67% Hartree-Fock exchange) yield the overall best
performance, working well for most of the considered properties and systems and
showing a balanced behavior for different problems. In particular, due to their
well-balanced accuracy, they perform well for the description of hybrid
metal-molecule interfaces.


title:
Producing a Unified Graph Representation from Multiple Social Network
  Views

abstract:
  In many social networks, several different link relations will exist between
the same set of users. Additionally, attribute or textual information will be
associated with those users, such as demographic details or user-generated
content. For many data analysis tasks, such as community finding and data
visualisation, the provision of multiple heterogeneous types of user data makes
the analysis process more complex. We propose an unsupervised method for
integrating multiple data views to produce a single unified graph
representation, based on the combination of the k-nearest neighbour sets for
users derived from each view. These views can be either relation-based or
feature-based. The proposed method is evaluated on a number of annotated
multi-view Twitter datasets, where it is shown to support the discovery of the
underlying community structure in the data.


title:
Studies of highly-boosted top quarks near the TeV scale using jet masses
  at the LHC

abstract:
  Studies of highly-boosted top quarks produced inclusively in pp collisions at
14 TeV are discussed. The hadronic decays of boosted top quarks was studied in
a data-driven approach by analysing shapes of jet-mass distributions. Using
Monte Carlo models after a fast detector simulation, it is shown that inclusive
production of boosted top quarks can be observed if it has a cross section at
least twice larger than the prediction from the approximate
next-to-next-to-leading-order (aNNLO) calculation for the ttbar process. The
ttbar process with the nominal aNNLO strength can be measured using the masses
of jets after a b-tagging.


title: The kernel bundle of a holomorphic Fredholm family

abstract:
  Let $\Y$ be a smooth connected manifold, $\Sigma\subset\C$ an open set and
$(\sigma,y)\to\scrP_y(\sigma)$ a family of unbounded Fredholm operators
$D\subset H_1\to H_2$ of index 0 depending smoothly on $(y,\sigma)\in \Y\times
\Sigma$ and holomorphically on $\sigma$. We show how to associate to $\scrP$,
under mild hypotheses, a smooth vector bundle $\kerb\to\Y$ whose fiber over a
given $y\in \Y$ consists of classes, modulo holomorphic elements, of
meromorphic elements $\phi$ with $\scrP_y\phi$ holomorphic. As applications we
give two examples relevant in the general theory of boundary value problems for
elliptic wedge operators.


title: Vacuum Stability in the Standard Model

abstract:
  The long-awaited Higgs particle H around 125 GeV has been observed at the
LHC. Interpreting it as the standard model Higgs boson and if there is no new
physics between electroweak and Planck scale, we then don't have a stable
vacuum. Here, we give a brief review of the electroweak vacuum stability and
some related theoretical issues in the standard model. Possible ways to save
the stability are also discussed.


title:
Nine months of monitoring of a V777-Her pulsator with the Kepler
  spacecraft

abstract:
  The V777 Her pulsator KIC 8626021 has been observed continuously by the
Kepler space telescope for nine months. Two new independent pulsation modes are
detected in the extended dataset, which both match the predicted sequence of
\ell = 2 modes. We demonstrate the photometric stability of the main pulsation
modes and discuss the prospect of measuring period changes within the context
of the extended Kepler mission.


title: On Singular Fibres in F-Theory

abstract:
  In this paper, we propose a connection between the field theory local model
(Katz-Vafa field theory) and the type of singular fibre in flat crepant
resolutions of elliptic Calabi-Yau fourfolds, a class of fourfolds considered
by Esole and Yau. We review the analysis of degenerate fibres for models with
gauge groups SU(5) and SO(10) in detail, and observe that the naively expected
fibre type is realized if and only if the Higgs vev in the field theory local
model is unramified. To test this idea, we implement a linear (unramified)
Higgs vev for the `E6' Yukawa point in a model with gauge group SU(5) and
verify that this indeed leads to a fibre of Kodaira type IV*. Based on this
observation, we argue i) that the singular fibre types appearing in the
fourfolds studied by Esole-Yau are not puzzling at all, (so that this class of
fourfolds does not have to be excluded from the candidate of input data of some
yet-unknown formulation of F-theory) and ii) that such fourfold geometries also
contain more information than just the eigenvalues of the Higgs field vev
configuration in the field theory local models.


title:
A continuation method for the efficient solution of parametric
  optimization problems in kinetic model reduction

abstract:
  Model reduction methods often aim at an identification of slow invariant
manifolds in the state space of dynamical systems modeled by ordinary
differential equations. We present a predictor corrector method for a fast
solution of an optimization problem the solution of which is supposed to
approximate points on slow invariant manifolds. The corrector method is either
an interior point method or a generalized Gauss--Newton method. The predictor
is an Euler prediction based on the parameter sensitivities of the optimization
problem. The benefit of a step size strategy in the predictor corrector scheme
is shown for an example.


title: Vertical mass hierarchy in the case study of a hybrid model

abstract:
  We study a hybrid model in which the Technicolor and fundamental heavy
scalars live together. We concern extreme case, where electroweak symmetry
breaking (EWSB) comes almost entirely from the strong dynamics of Technicolor,
but the masses of the light fermions, e.g. leptons arises due to the weakly
interacting scalars with one universal Yukawa interaction. We have found that
SU(2) scalar two doublets, which are private but universal for each generation,
offer a natural explanation of the vertical mass hierarchy. There is no large
Yukawa coupling in the theory and the scalar masses are expected to be quite
universal and large. The lepton mass hierarchy arises radiatively from the
quark mass hierarchy, which is affected by the scalar sector as well. Lepton
and down quark masses are calculated in a simplified case of neglected mixing.


title:
On vertical variations of gas flow in protoplanetary disks and their
  impact on the transport of solids

abstract:
  A major uncertainty in accretion disk theory is the nature and properties of
gas turbulence, which drives transport in protoplanetary disks. The commonly
used viscous prescription for the Maxwell-Reynolds stress tensor gives rise to
a meridional circulation where flow is outward near the midplane and inward
away from it. This meridional circulation has been proposed as an explanation
for the presence of high-temperature minerals (believed to be of inner solar
system provenance) in comets. However, it has not been observed in simulations
of magnetohydrodynamical (MHD) turbulence so far. In this study, we evaluate
the extent to which the net transport of solids can be diagnostic of the
existence of meridional circulation. To that end, we propose and motivate a
prescription for MHD turbulence which has the same free parameters as the
viscous one. We compare the effects of both prescriptions on the radial
transport of small solid particles and find that their net, vertically
integrated radial flux is actually quite insensitive to the flow structure for
a given vertical average of the turbulence parameter $\alpha$, which we
explain. Given current uncertainties on disk turbulence, one-dimensional models
are thus most appropriate to investigate radial transport of solids. A
corollary is that the presence of high-temperature material in comets cannot be
considered an unequivocal diagnostic of meridional circulation. In fact, we
argue that outward transport in viscous disk models is more properly attributed
to turbulent diffusion rather than to the mean flows of the gas.


title: Hypoellipticity and vanishing theorems

abstract:
  Let $-\im\Lie_\T$ (essentially Lie derivative with respect to $\T$, a smooth
nowhere zero real vector field) and $P$ be commuting differential operators,
respectively of orders 1 and $m\geq 1$, the latter formally normal, both acting
on sections of a vector bundle over a closed manifold. It is shown that if
$P+(-i\Lie_\T)^m$ is elliptic then the restriction of $-\im\Lie_\T$ to
$\Dom\subset \ker P\subset L^2$ yields a selfadjoint operator
$-\im\Lie_\T|_\Dom:\Dom\subset\ker P\to \ker P$ with compact resolvent ($\Dom$
is specified carefully). It is also shown that, in the presence of an
additional hypothesis on microlocal hypoellipticity of $P$, $-\im\Lie_\T|_\Dom$
is semi-bounded. These results are applied to CR manifolds on which $\T$ acts
as an infinitesimal CR transformation which are then shown to yield versions of
Kodaira's vanishing theorem.


title: On a Poincare lemma for foliations

abstract:
  In this paper we revisit a Poincare lemma for foliated forms, with respect to
a regular foliation, and compute the foliated cohomology for local models of
integrable systems with singularities of nondegenerate type. A key point in
this computation is the use of some analytical tools for integrable systems
with nondegenerate singularities, including a Poincare lemma for the
deformation complex associated to this singular foliation.


title: Elliptic systems of variable order

abstract:
  The general theory of boundary value problems for linear elliptic wedge
operators (on smooth manifolds with boundary) leads naturally, even in the
scalar case, to the need to consider vector bundles over the boundary together
with general smooth fiberwise multiplicative group actions. These actions,
essentially trivial (and therefore invisible) in the case of regular boundary
value problems, are intimately connected with what passes for Poisson and trace
operators, and to pseudodifferential boundary conditions in the more general
situation. Here the part of the theory pertaining pseudodifferential operators
is presented in its entirety. The symbols for the latter operators are defined
with the aid of an intertwining of the actions. Also presented here are the
ancillary Sobolev spaces, an index theorem for the elliptic elements of the
pseudodifferential calculus, and the essential ingredients of the APS boundary
condition in the more general theory.


title: Ecosystems perspective on financial networks: diagnostic tools

abstract:
  The economical world consists of a highly interconnected and interdependent
network of firms. Here we develop temporal and structural network tools to
analyze the state of the economy. Our analysis indicates that a strong
clustering can be a warning sign. Reduction in diversity, which was an
essential aspect of the dynamics surrounding the crash in 2008, is seen as a
key emergent feature arising naturally from the evolutionary and adaptive
dynamics inherent to the financial markets. Similarly, collusion amongst
construction firms in a number of regions in Japan in the 2000s can be
identified with the formation of clusters of anomalous highly connected
companies.


title: Fractional Fermions with Non-Abelian Statistics

abstract:
  We introduce a novel class of low-dimensional topological tight-binding
models that allow for bound states that are fractionally charged fermions and
exhibit non-Abelian braiding statistics. The proposed model consists of a
double (single) ladder of spinless (spinful) fermions in the presence of
magnetic fields. We study the system analytically in the continuum limit as
well as numerically in the tight-binding representation. We find a topological
phase transition with a topological gap that closes and reopens as a function
of system parameters and chemical potential. The topological phase is of the
type BDI and carries two degenerate mid-gap bound states that are localized at
opposite ends of the ladders. We show numerically that these bound states are
robust against a wide class of perturbations.


title:
Study of the Onset of Deconfinement and Search for the Critical Point of
  Strongly Interacting Matter

abstract:
  Collisions of lead nuclei have been studied at the CERN SPS since 1994. A
review is presented of the evidence for the production of deconfined matter,
the location of the energy of the onset of deconfinement and the search for the
critical point of stronly interacting matter


title:
Quantifying extrinsic noise in gene expression using the maximum entropy
  framework

abstract:
  We present a maximum entropy framework to separate intrinsic and extrinsic
contributions to noisy gene expression solely from the profile of expression.
We express the experimentally accessible probability distribution of the copy
number of the gene product (mRNA or protein) by accounting for possible
variations in extrinsic factors. The distribution of extrinsic factors is
estimated using the maximum entropy principle. Our results show that extrinsic
factors qualitatively and quantitatively affect the probability distribution of
the gene product. We work out, in detail, the transcription of mRNA from a
constitutively expressed promoter in {\it E. coli}. We suggest that the
variation in extrinsic factors may account for the observed {\it wider than
Poisson} distribution of mRNA copy numbers. We successfully test our framework
on a numerical simulation of a simple gene expression scheme that accounts for
the variation in extrinsic factors. We also make falsifiable predictions, some
of which are tested on previous experiments in {\it E. coli} while others need
verification. Application of the current framework to more complex situations
is also discussed.


title:
An ultracold analogue to star formation: Spontaneous concentration of
  energy in trapped quantum gases

abstract:
  Stars form when cold cosmic nebulae spontaneously develop hot spots that
steadily intensify until they reach fusion temperatures. Without this process,
the universe would be dark and dead. Yet the spontaneous concentration of heat
is exactly what the Second Law of Thermodynamics is in most cases supposed to
forbid. The formation of protostars has been much discussed, for its
consistency with the Second Law depends on a thermodynamical property that is
common in systems whose strongest force is their own gravity, but otherwise
very rare: negative specific heat. Negative specific heat turns the world
upside down, thermodynamically; it implies that entropy increases when energy
flows from lower to higher energy subsystems, opposite to the usual direction.
Recent experiments have reported negative specific heat in melting atomic
clusters and fragmenting nuclei, but these arguably represent transient
phenomena outside the proper scope of thermodynamics. Here we show that the
counter-intuitive thermodynamics of spontaneous energy concentration can be
studied experimentally with trapped quantum gases, by using optical lattice
potentials to realize weakly coupled arrays of simple dynamical subsystems that
share the peculiar property of self-gravitating protostars, of having negative
micro-canonical specific heat. Numerical solution of real-time evolution
equations confirms the spontaneous concentration of energy in such arrays, with
initially dispersed energy condensing quickly into dense 'droplets'. We
therefore propose laboratory studies of negative specific heat as an elusive
but fundamentally important aspect of thermodynamics, which may shed fresh
light on the general problem of how thermodynamics emerges from mechanics.


title: Thermodynamic properties of QCD in external magnetic fields

abstract:
  We consider the effect of strong external electromagnetic fields on
thermodynamic observables in QCD, through lattice simulations with 1+1+1
flavors of staggered quarks at physical quark masses. Continuum extrapolated
results are presented for the light quark condensates and for their tensor
polarizations, as functions of the temperature and the magnetic field. We find
the light condensates to undergo inverse magnetic catalysis in the transition
region, in a manner that the transition temperature decreases with growing
magnetic field. We also compare the results to other approaches and lattice
simulations. Furthermore, we relate the tensor polarization to the spin part of
the magnetic susceptibility of the QCD vacuum, and show that this contribution
is diamagnetic.


title:
1D to 2D Na Ion Diffusion Inherently Linked to Structural Transitions in
  Na$_{0.7}$CoO$_{2}$

abstract:
  We report the observation of a stepwise "melting" of the low-temperature
Na-vacancy order in the layered transition metal oxide Na0.7CoO2.
High-resolution neutron powder diffraction indicates the existence of two
first-order structural transitions, one at T1 = 290 K, followed by a second at
T2 = 400 K. Detailed analysis reveals that both transitions are linked to
changes in the Na mobility. Our data are consistent with a two-step
disappearance of Na-vacancy order through the successive opening of first
quasi-1D (T1 > T > T2) and then 2D (T > T2) Na diffusion paths. These results
shed new light on previous, seemingly incompatible, experimental
interpretations regarding the relationship between Na-vacancy order and Na
dynamics in this material. They also represent an important step towards the
tuning of physical properties and the design of tailored functional materials
through an improved control and understanding of ionic diffusion.


title:
Re-examining the role of curvature in the slowing down acceleration
  scenario

abstract:
  By incorporating the curvature $\Omega_k$ as a free parameter, it has been
found that the tension between the high redshift CMB shift parameter
$R(z^{\ast})$ data and the low redshift SNIa and BAO data from the combination
of SDSS and 2dFGRS can be ameliorated, and both SNIa+BAO and SNIa+BAO+CMB favor
that the decelerating parameter $q(z)$ shows a rapid variation in sign at small
redshift. In this paper, with the MCMC method, we re-examine the evolutionary
behavior of $q(z)$ using the latest observational data including the Union2
SNIa, BAO, and CMB data ($R(z^{\ast})$, $l_{A}(z^{\ast})$, $z^{\ast}$) from
WMAP7. For BAO data, four different data sets obtained from the 6dFGS, the
combination of SDSS and 2dFGRS, the WiggleZ dark energy survey and the BOSS,
are used. Except for the spatially flat case constrained by SNIa+ the WiggleZ
BAO data, both SNIa and other BAO+SNIa favor that the present cosmic
acceleration is slowing down irrespective of whether the spatial curvature is
included or not. However, once the WMAP7 CMB data is included, observations
favor strongly the $\Lambda$CDM model, a spatially flat universe, and a
speeding-up of the cosmic acceleration. Therefore, the inclusion of spatial
curvature seems to has no effect on alleviating the tension between SNIa+BAO
and CMB in clear contrast to the previous work in the literature.


title:
Chern class and Riemann-Roch theorem for cohomology theory without
  homotopy invariance

abstract:
  In this paper, we formulate axioms of certain graded cohomology theory for
which Chern class maps from higher K-theory are defined, following the method
of Gillet [Gi1]. We will not include homotopy invariance nor purity in our
axioms. It will turn out that the Grothendieck-Riemann-Roch theorem and the
Riemann-Roch theorem without denominators hold for our higher Chern classes. We
will also give two applications of our Riemann-Roch results.


title:
The nuclear structure and related properties of some low-lying isomers
  of free-space O_n clusters (n=6, 8, 12)

abstract:
  After some introductory comments relating to antiferromagnetism of
crystalline O_2, and brief remarks on the geometry of ozone, Hartree-Fock (HF)
theory plus second-order Moller-Plesset (MP2) corrections are used to predict
the nuclear structure of low-lying isomers of free-space O_n clusters, for n=6,
8, and 12. The equilibrium nuclear-nuclear potential energy is also discussed
in relation to the number n of oxygen atoms in the cluster.


title:
Canalization and control in automata networks: body segmentation in
  Drosophila melanogaster

abstract:
  We present schema redescription as a methodology to characterize canalization
in automata networks used to model biochemical regulation and signalling. In
our formulation, canalization becomes synonymous with redundancy present in the
logic of automata. This results in straightforward measures to quantify
canalization in an automaton (micro-level), which is in turn integrated into a
highly scalable framework to characterize the collective dynamics of
large-scale automata networks (macro-level). This way, our approach provides a
method to link micro- to macro-level dynamics -- a crux of complexity. Several
new results ensue from this methodology: uncovering of dynamical modularity
(modules in the dynamics rather than in the structure of networks),
identification of minimal conditions and critical nodes to control the
convergence to attractors, simulation of dynamical behaviour from incomplete
information about initial conditions, and measures of macro-level canalization
and robustness to perturbations. We exemplify our methodology with a well-known
model of the intra- and inter cellular genetic regulation of body segmentation
in Drosophila melanogaster. We use this model to show that our analysis does
not contradict any previous findings. But we also obtain new knowledge about
its behaviour: a better understanding of the size of its wild-type attractor
basin (larger than previously thought), the identification of novel minimal
conditions and critical nodes that control wild-type behaviour, and the
resilience of these to stochastic interventions. Our methodology is applicable
to any complex network that can be modelled using automata, but we focus on
biochemical regulation and signalling, towards a better understanding of the
(decentralized) control that orchestrates cellular activity -- with the
ultimate goal of explaining how do cells and tissues 'compute'.


title: A new extended quintessence

abstract:
  Extended quintessence is obtained by coupling a normal scalar field to the
Ricci scalar defined in the metric formalism. In this paper, we propose a new
extended quintessence dark energy by introducing a non-minimal coupling between
the quintessence and gravity, but with the Ricci scalar given from the Palatini
formalism rather than the metric one. We find that the equation of state of the
new extended quintessence can cross the phantom divide line, and moreover, it
oscillates around the -1 line. We also show that the universe driven by the new
extended quintessence will enter a dark energy dominated de Sitter phase in the
future.


title: Associating quantum vertex algebras to Lie algebra $\gl_{\infty}$

abstract:
  In this paper, we present a canonical association of quantum vertex algebras
and their $\phi$-coordinated modules to Lie algebra $\gl_{\infty}$ and its
1-dimensional central extension. To this end we construct and make use of
another closely related infinite-dimensional Lie algebra.


title:
Elasto-capillary meniscus: Pulling out a soft strip sticking to a liquid
  surface

abstract:
  A liquid surface touching a solid usually deforms in a near-wall meniscus
region. In this work, we replace part of the free surface with a soft polymer
and examine the shape of this elasto-capillary meniscus, result of the
interplay between elasticity, capillarity and hydrostatic pressure. We focus
particularly on the extraction threshold for the soft object. Indeed, we
demonstrate both experimentally and theoretically the existence of a limit
height of liquid tenable before breakdown of the compound, and extraction of
the object. Such an extraction force is known since Laplace and Gay-Lussac, but
only in the context of rigid floating objects. We revisit this classical
problem by adding the elastic ingredient and predict the extraction force in
terms of the strip elastic properties. It is finally shown that the critical
force can be increased with elasticity, as is commonplace in adhesion phenomena


title: C58 on Au(111): a scanning tunneling microscopy study

abstract:
  C58 fullerenes were adsorbed onto room temperature Au(111) surface by
low-energy (~6 eV) cluster ion beam deposition under ultrahigh vacuum
conditions. The topographic and electronic properties of the deposits were
monitored by means of scanning tunnelling microscopy (STM at 4.2 K).
Topographic images reveal that at low coverages fullerene cages are pinned by
point dislocation defects on the herringbone reconstructed gold terraces (as
well as by step edges). At intermediate coverages, pinned monomers, act as
nucleation centres for the formation of oligomeric C58 chains and 2D islands.
At the largest coverages studied, the surface becomes covered by 3D interlinked
C58 cages. STM topographic images of pinned single adsorbates are essentially
featureless. The corresponding local densities of states are consistent with
strong cage-substrate interactions. Topographic images of [C58]n oligomers show
a stripe-like intensity pattern oriented perpendicular to the axis connecting
the cage centers. This striped pattern becomes even more pronounced in maps of
the local density of states. As supported by density functional theory, DFT
calculations, and also by analogous STM images previously obtained for C60
polymers (M. Nakaya et al., J. Nanosci. Nanotechnol. 11, 2829 (2011)), we
conclude that these striped orbital patterns are a fingerprint of covalent
intercage bonds. For thick C58 films we have derived a band gap of 1.2 eV from
scanning tunnelling spectroscopy data, STS, confirming that the outermost C58
layer behaves as a wide band semiconductor.


title: Tight Hamilton cycles in random hypergraphs

abstract:
  We give an algorithmic proof for the existence of tight Hamilton cycles in a
random r-uniform hypergraph with edge probability p=n^{-1+eps} for every eps>0.
This partly answers a question of Dudek and Frieze [Random Structures
Algorithms], who used a second moment method to show that tight Hamilton cycles
exist even for p=omega(n)/n (r>2) where omega(n) tends to infinity arbitrary
slowly, and for p=(e+o(1))/n (r>3).
  The method we develop for proving our result applies to related problems as
well.


title: Gate controlled coupling of intersubband plasmons

abstract:
  The optical response of a heavily doped quantum well, with two occupied
subbands, has been investigated as a function of the electronic density. It is
shown that the two optically active transitions are mutually coupled by
dipole-dipole Coulomb interaction, which strongly renormalizes their absorption
amplitude. In order to demonstrate this effect, we have measured a set of
optical spectra on a device in which the electronic density can be tuned by the
application of a gate voltage. Our results show that the absorption spectra can
be correctly described only by taking into account the Coulomb coupling between
the two transitions. As a consequence, the optical dipoles originating from
intersubband transitions are not independent, but rather coupled oscillators
with an adjustable strength.


title:
Diffusion scale tightness of invariant distributions of a large-scale
  flexible service system

abstract:
  A large-scale service system with multiple customer classes and multiple
server pools is considered, with the mean service time depending both on the
customer class and server pool. The allowed activities (routing choices) form a
tree (in the graph with vertices being both customer classes and server pools).
We study the behavior of the system under a {\em Leaf Activity Priority} (LAP)
policy, introduced in [17]. An asymptotic regime is considered, where the
arrival rate of customers and number of servers in each pool tend to infinity
in proportion to a scaling parameter $r$, while the overall system load remains
strictly subcritical. We prove tightness of diffusion-scaled (centered at the
equilibrium point and scaled down by $r^{-1/2}$) invariant distributions. As a
consequence, we obtain a limit interchange result: the limit of
diffusion-scaled invariant distributions is equal to the invariant distribution
of the limiting diffusion process.


title:
Planck intermediate results. XII: Diffuse Galactic components in the
  Gould Belt System

abstract:
  We perform an analysis of the diffuse low-frequency Galactic components in
the Southern part of the Gould Belt system (130^\circ\leq l\leq 230^\circ and
-50^\circ\leq b\leq -10^\circ). Strong ultra-violet (UV) flux coming from the
Gould Belt super-association is responsible for bright diffuse foregrounds that
we observe from our position inside the system and that can help us improve our
knowledge of the Galactic emission. Free-free emission and anomalous microwave
emission (AME) are the dominant components at low frequencies (\nu < 40 GHz),
while synchrotron emission is very smooth and faint. We separate diffuse
free-free emission and AME from synchrotron emission and thermal dust emission
by using Planck data, complemented by ancillary data, using the "Correlated
Component Analysis" (CCA) component separation method and we compare with the
results of cross-correlation of foreground templates with the frequency maps.
We estimate the electron temperature T_e from H$\alpha$ and free-free emission
using two methods (temperature-temperature plot and cross-correlation) and we
obtain T_e ranging from 3100 to 5200 K, for an effective fraction of absorbing
dust along the line of sight of 30% (f_d=0.3). We estimate the frequency
spectrum of the diffuse AME and we recover a peak frequency (in flux density
units) of 25.5 \pm 1.5 GHz. We verify the reliability of this result with
realistic simulations that include the presence of biases in the spectral model
for the AME and in the free-free template. By combining physical models for
vibrational and rotational dust emission and adding the constraints from the
thermal dust spectrum from Planck and IRAS we are able to get a good
description of the frequency spectrum of the AME for plausible values of the
local density and radiation field.


title:
Transition of a particle between adjacent optical traps: A study using
  catastrophe theory

abstract:
  In spite of the widespread use of optical tweezers as a quantitative tool to
measure small forces, there exists no unambiguous and simple experimental
method for either validating its theoretically predicted form or empirically
parameterizing it over the entire range. This problem is addressed by studying
the transition of a colloidal particle between two spatially separated optical
traps. The transition as a function of the relative intensity of the traps and
the separation between them reveals a formal resemblance to the `butterfly
catastrophe' which also maps onto to phase transitions observed, for example in
ferroelectrics, on a phenomenological level. The method has been used to
experimentally determine the force-displacement curve for an optical trap over
its entire range.


title:
Rings and modules which are stable under automorphisms of their
  injective hulls

abstract:
  It is proved, among other results, that a prime right nonsingular ring (in
particular, a simple ring) $R$ is right self-injective if $R_R$ is invariant
under automorphisms of its injective hull. This answers two questions raised by
Singh and Srivastava, and Clark and Huynh. An example is given to show that
this conclusion no longer holds when prime ring is replaced by semiprime ring
in the above assumption. Also shown is that automorphism-invariant modules are
precisely pseudo-injective modules, answering a recent question of Lee and
Zhou. Furthermore, rings whose cyclic modules are automorphism-invariant are
investigated.


title: Approximation of grammar-based compression via recompression

abstract:
  In this paper we present a simple linear-time algorithm constructing a
context-free grammar of size O(g log(N/g)) for the input string, where N is the
size of the input string and g the size of the optimal grammar generating this
string. The algorithm works for arbitrary size alphabets, but the running time
is linear assuming that the alphabet \Sigma of the input string can be
identified with numbers from {1, ..., N^c} for some constant c. Otherwise,
additional cost of O(n log|\Sigma|) is needed.
  Algorithms with such approximation guarantees and running time are known, the
novelty of this paper is a particular simplicity of the algorithm as well as
the analysis of the algorithm, which uses a general technique of recompression
recently introduced by the author. Furthermore, contrary to the previous
results, this work does not use the LZ representation of the input string in
the construction, nor in the analysis.


title:
The different varieties of the Suyama-Yamaguchi consistency relation and
  its violation as a signal of statistical inhomogeneity

abstract:
  We present the different consistency relations that can be seen as variations
of the well known Suyama-Yamaguchi (SY) consistency relation \tau_{NL}
\geqslant ((6/5) f_{NL})^2. It has been claimed that the following variation:
\tau_{NL} ({\bf k}_1, {\bf k_3}) \geqslant (6/5)^2 f_{NL} ({\bf k}_1) f_{NL}
({\bf k}_3), which we call "the fourth variety", in the collapsed (for
\tau_{NL}) and squeezed (for f_{NL}) limits is always satisfied independently
of any physics; however, the proof depends sensitively on the assumption of
scale-invariance which only applies for cosmological models involving
Lorentz-invariant scalar fields (at least at tree level), leaving room for a
strong violation of this variety of the consistency relation when non-trivial
degrees of freedom, for instance vector fields, are in charge of the generation
of \zeta. With this in mind as a motivation, we explicitly state under which
conditions the SY consistency relation has been claimed to hold in its
different varieties (implicitly) presented in the literature; as a result, we
show for the first time that the variety \tau_{NL} ({\bf k}_1, {\bf k}_1)
\geqslant ((6/5) f_{NL} ({\bf k}_1))^2, which we call "the fifth variety", is
always satisfied even when there is strong scale-dependence as long as
statistical homogeneity holds: thus, an observed violation of this specific
variety would prevent the comparison between theory and observation, shaking
this way the foundations of cosmology as a science. Later, we concern about the
existence of non-trivial degrees of freedom, concretely vector fields for which
the levels of non-gaussianity have been calculated for very few models, finding
that the fourth variety of the SY consistency relation is indeed strongly
violated for some specific wavevector configurations while the fifth variety
continues to be well satisfied. (Abridged)


title: Ranking Games that have Competitiveness-based Strategies

abstract:
  An extensive literature in economics and social science addresses contests,
in which players compete to outperform each other on some measurable criterion,
often referred to as a player's score, or output. Players incur costs that are
an increasing function of score, but receive prizes for obtaining higher score
than their competitors. In this paper we study finite games that are
discretized contests, and the problems of computing exact and approximate Nash
equilibria. Our motivation is the worst-case hardness of Nash equilibrium
computation, and the resulting interest in important classes of games that
admit polynomial-time algorithms. For games that have a tie-breaking rule for
players' scores, we present a polynomial-time algorithm for computing an exact
equilibrium in the 2-player case, and for multiple players, a characterization
of Nash equilibria that shows an interesting parallel between these games and
unrestricted 2-player games in normal form. When ties are allowed, via a
reduction from these games to a subclass of anonymous games, we give
approximation schemes for two special cases: constant-sized set of strategies,
and constant number of players.


title:
Enhanced J/Psi-pair production from double parton scatterings in
  nucleus-nucleus collisions at the Large Hadron Collider

abstract:
  A generic expression of double-parton scattering cross sections in
high-energy nucleus-nucleus (A-A) collisions is derived as a function of the
corresponding single-parton hard cross sections and of the A-A event
centrality. We consider the case of prompt-J/psi production in lead-lead
(Pb-Pb) at the CERN Large Hadron Collider and find that about 20% (35%) of the
J/psi events in minimum-bias (most central) collisions contain a second J/psi
from double parton interactions. In Pb-Pb at 5.5 TeV, in the absence of
final-state effects, about 240 double-J/psi events are expected per unit
midrapidity and per inverse-nanobarn in the dilepton decay modes. The
implications of double-J/psi production on the interpretation of the observed
J/psi suppression in A-A collisions are discussed.


title: Measuring ultrasmall time delays of light by joint weak measurements

abstract:
  We propose to use weak measurements away from the weak-value amplification
regime to carry out precision measurements of time delays of light. Our scheme
is robust to several sources of noise that are shown to only limit the relative
precision of the measurement. Thus, they do not set a limit on the smallest
measurable phase shift contrary to standard interferometry and weak-value based
measurement techniques. Our idea is not restricted to phase-shift measurements
and could be used to measure other small effects using a similar protocol.


title: Slowly rotating gas-rich galaxies in modified Newtonian dynamics (MOND)

abstract:
  We have carried out a search for gas-rich dwarf galaxies that have lower
rotation velocities in their outskirts than MOdified Newtonian Dynamics (MOND)
predicts, so that the amplitude of their rotation curves cannot be fitted by
arbitrarily increasing the mass-to-light ratio of the stellar component or by
assuming additional undetected matter. With presently available data, the
gas-rich galaxies UGC 4173, Holmberg II, ESO 245-G05, NGC 4861 and ESO 364-G029
deviate most from MOND predictions and, thereby, provide a sample of promising
targets in testing the MOND framework. In the case of Holmberg II and NGC 4861,
we find that their rotation curves are probably inconsistent with MOND, unless
their inclinations and distances differ significantly from the nominal ones.
The galaxy ESO 364-G029 is a promising target because its baryonic mass and
rotation curve are similar to Holmberg II but presents a higher inclination.
Deeper photometric and HI observations of ESO 364-G029, together with further
decreasing systematic uncertainties, may provide a strong test to MOND.


title: Decentralized Coded Caching Attains Order-Optimal Memory-Rate Tradeoff

abstract:
  Replicating or caching popular content in memories distributed across the
network is a technique to reduce peak network loads. Conventionally, the main
performance gain of this caching was thought to result from making part of the
requested data available closer to end users. Instead, we recently showed that
a much more significant gain can be achieved by using caches to create
coded-multicasting opportunities, even for users with different demands,
through coding across data streams. These coded-multicasting opportunities are
enabled by careful content overlap at the various caches in the network,
created by a central coordinating server.
  In many scenarios, such a central coordinating server may not be available,
raising the question if this multicasting gain can still be achieved in a more
decentralized setting. In this paper, we propose an efficient caching scheme,
in which the content placement is performed in a decentralized manner. In other
words, no coordination is required for the content placement. Despite this lack
of coordination, the proposed scheme is nevertheless able to create
coded-multicasting opportunities and achieves a rate close to the optimal
centralized scheme.


title: Detecting the integrated Sachs-Wolfe effect with stacked voids

abstract:
  The stacking of cosmic microwave background (CMB) patches has been recently
used to detect the integrated Sachs-Wolfe effect (iSW). When focusing on the
locations of superstructures identified in the Sloan Digital Sky Survey (SDSS),
Granett et al. (2008a, Gr08) found a signal with strong significance and an
amplitude reportedly higher than expected within the LambdaCDM paradigm. We
revisit the analysis using our own robust protocol, and extend the study to the
two most recent and largest catalogues of voids publicly available. We quantify
and subtract the level of foreground contamination in the stacked images and
determine the contribution on the largest angular scales from the first
multipoles of the CMB. We obtain the radial temperature and photometry profiles
from the stacked images. Using a Monte Carlo approach, we computed the
statistical significance of the profiles for each catalogue and identified the
angular scale at which the signal-to-noise ratio (S/N) is maximum. We
essentially confirm the signal detection reported by Gr08, but for the other
two catalogues, a rescaling of the voids to the same size on the stacked image
is needed to find any significant signal (with a maximum at ~2.4 sigmas). This
procedure reveals that the photometry peaks at unexpectedly large angles in the
case of the Gr08 voids, in contrast to voids from other catalogues. Conversely,
the photometry profiles derived from the stacked voids of these other
catalogues contain small central hot spots of uncertain origin. We also stress
the importance of a posteriori selection effects that might arise when
intending to increase the S/N, and we discuss the possible impact of void
overlap and alignment effects. We argue that the interpretation in terms of an
iSW effect of any detected signal via the stacking method is far from obvious.


title:
Atomic polyadic algebras of infinite dimension are completely
  representable

abstract:
  We show that atomic polyadic algebras of infinite dimensions are completely
representable


title: Soliton dynamics of an atomic spinor condensate on a Ring Lattice

abstract:
  We study the dynamics of macroscopically-coherent matter waves of an
ultra-cold atomic spin-one or spinor condensate on a ring lattice of six sites
and demonstrate a novel type of spatio-temporal internal Josephson effect.
Using a discrete solitary mode of uncoupled spin components as an initial
condition, the time evolution of this many-body system is found to be
characterized by two dominant frequencies leading to quasiperiodic dynamics at
various sites. The dynamics of spatially-averaged and spin-averaged degrees of
freedom, however, is periodic enabling an unique identification of the two
frequencies. By increasing the spin-dependent atom-atom interaction strength we
observe a resonance state, where the ratio of the two frequencies is a
characteristic integer multiple and the spin-and-spatial degrees of freedom
oscillate in "unison". Crucially, this resonant state is found to signal the
onset to chaotic dynamics characterized by a broad band spectrum. In a
ferromagnetic spinor condensate with attractive spin-dependent interactions,
the resonance is accompanied by a transition from oscillatory- to
rotational-type dynamics as the time evolution of the relative phase of the
matter wave of the individual spin projections changes from bounded to
unbounded.


title: On a Multiple-Access in a Vector Disjunctive Channel

abstract:
  We address the problem of increasing the sum rate in a multiple-access system
from [1] for small number of users. We suggest an improved signal-code
construction in which in case of a small number of users we give more resources
to them. For the resulting multiple-access system a lower bound on the relative
sum rate is derived. It is shown to be very close to the maximal value of
relative sum rate in [1] even for small number of users. The bound is obtained
for the case of decoding by exhaustive search. We also suggest
reduced-complexity decoding and compare the maximal number of users in this
case and in case of decoding by exhaustive search.


title: Hierarchical Multiscale Modeling of Macromolecules and their Assemblies

abstract:
  Soft materials (e.g., enveloped viruses, liposomes, membranes and supercooled
liquids) simultaneously deform or display collective behaviors, while
undergoing atomic scale vibrations and collisions. While the multiple
space-time character of such systems often makes traditional molecular dynamics
simulation impractical, a multiscale approach has been presented that allows
for long-time simulation with atomic detail based on the co-evolution of
slowly-varying order parameters (OPs) with the quasi-equilibrium probability
density of atomic configurations. However, this approach breaks down when the
structural change is extreme, or when nearest-neighbor connectivity of atoms is
not maintained. In the current study, a self-consistent approach is presented
wherein OPs and a reference structure co-evolve slowly to yield long-time
simulation for dynamical soft-matter phenomena such as structural transitions
and self assembly. The development begins with the Liouville equation for N
classical atoms and an ansatz on the form of the associated N-atom probability
density. Multiscale techniques are used to derive Langevin equations for the
coupled OP configurational dynamics. The net result is a set of equations for
the coupled stochastic dynamics of the OPs and centers of mass of the
subsystems that constitute a soft material body. The theory is based on an
all-atom methodology and an interatomic force field, and therefore enables
calibration-free simulations of soft matter, such as macromolecular assemblies.


title: Dynamical Critical Phenomena in Driven-Dissipative Systems

abstract:
  We explore the nature of the Bose condensation transition in driven open
quantum systems, such as exciton-polariton condensates. Using a functional
renormalization group approach formulated in the Keldysh framework, we
characterize the dynamical critical behavior that governs decoherence and an
effective thermalization of the low frequency dynamics. We identify a critical
exponent special to the driven system, showing that it defines a new dynamical
universality class. Hence critical points in driven systems lie beyond the
standard classification of equilibrium dynamical phase transitions. We show how
the new critical exponent can be probed in experiments with driven cold atomic
systems and exciton-polariton condensates.


title:
Leptonic decay-constant ratio f_{K^+}/f_{pi^+} from lattice QCD with
  physical light quarks

abstract:
  A calculation of the ratio of leptonic decay constants f_{K^+}/f_{\pi^+}
makes possible a precise determination of the ratio of CKM matrix elements
|V_{us}|/|V_{ud}| in the Standard Model, and places a stringent constraint on
the scale of new physics that would lead to deviations from unitarity in the
first row of the CKM matrix. We compute f_{K^+}/f_{\pi^+} numerically in
unquenched lattice QCD using gauge-field ensembles recently generated that
include four flavors of dynamical quarks: up, down, strange, and charm. We
analyze data at four lattice spacings a ~ 0.06, 0.09, 0.12, and 0.15 fm with
simulated pion masses down to the physical value 135 MeV. We obtain
f_{K^+}/f_{\pi^+} = 1.1947(26)(37), where the errors are statistical and total
systematic, respectively. This is our first physics result from our N_f = 2+1+1
ensembles, and the first calculation of f_{K^+}/f_{\pi^+} from lattice-QCD
simulations at the physical point. Our result is the most precise lattice-QCD
determination of f_{K^+}/f_{\pi^+}, with an error comparable to the current
world average. When combined with experimental measurements of the leptonic
branching fractions, it leads to a precise determination of |V_{us}|/|V_{ud}| =
0.2309(9)(4) where the errors are theoretical and experimental, respectively.


title: Custodial Leptons and Higgs Decays

abstract:
  We study the effects of extended fermion sectors, respecting custodial
symmetry, on Higgs production and decay. The resulting protection for the
Z->b_L b_L and Z->\tau_R\tau_R decays allows for potentially interesting
signals in Higgs physics, while maintaining the good agreement of the Standard
Model with precision tests, without significant fine-tuning. Although being
viable setups on their own, the models we study can particularly be motivated
as the low energy effective theories of the composite Higgs models MCHM_5 and
MCHM_10 or the corresponding gauge-Higgs unification models. The spectra can be
identified with the light custodians present in these theories. These have the
potential to describe the relevant physics in their fermion sectors in a
simplified and transparent way. In contrast to previous studies of composite
models, we consider the impact of a realistic lepton sector on the Higgs
decays. We find significant modifications in the decays to \tau leptons and
photons due to the new leptonic resonances. While from a pure low energy
perspective an enhancement of the channel pp->h->\gamma\gamma turns out to be
possible, if one considers constraints on the parameters from the full
structure of the composite models, the decay mode into photons is always
reduced. We also demonstrate that taking into account the non-linearity of the
Higgs sector does not change the qualitative picture for the decays into
\tau-leptons or photons in the case of the dominant Higgs production mechanism.


title: Quantum theory of reactive collisions for 1/r^n potentials

abstract:
  We develop a general quantum theory for reactive collisions involving
power-law potentials (-1/r^n) valid from the ultracold up to the
high-temperature limit. Our quantum defect framework extends the conventional
capture models to include the non-universal case when the short-range reaction
probability P^{re} < 1. We present explicit analytical formulas as well as
numerical studies for the van der Waals (n = 6) and polarization (n = 4)
potentials, and relate our work to recent merged beam experiments on Penning
ionization for collision energies below 0.1 meV [Henson et al, Science 338,
234(2012)].


title: Non-Homogeneous Local $T1$ Theorem: Dual Exponents

abstract:
  We provide an alternative proof of a (local) T1 theorem for dual exponents in
the non-homogeneous setting of upper doubling measures. This previously known
theorem provides necessary and sufficient conditions for the L^p-boundedness of
Calder\'on-Zygmund operators in the described setting, and the novelty lies in
the method of proof.


title: Hamiltonian spinfoam gravity

abstract:
  This paper presents a Hamiltonian formulation of spinfoam-gravity, which
leads to a straight-forward canonical quantisation. To begin with, we derive a
continuum action adapted to the simplicial decomposition. The equations of
motion admit a Hamiltonian formulation, allowing us to perform the constraint
analysis. We do not find any secondary constraints, but only get restrictions
on the Lagrange multipliers enforcing the reality conditions. This comes as a
surprise. In the continuum theory, the reality conditions are preserved in
time, only if the torsionless condition (a secondary constraint) holds true.
Studying an additional conservation law for each spinfoam vertex, we discuss
the issue of torsion and argue that spinfoam gravity may indeed miss an
additional constraint. Next, we canonically quantise. Transition amplitudes
match the EPRL (Engle--Pereira--Rovelli--Livine) model, the only difference
being the additional torsional constraint affecting the vertex amplitude.


title: On the dimension of a certain measure in the plane

abstract:
  We study the Hausdorff dimension of a measure related to a positive weak
solution of a certain partial differential equation in a simply connected
domain in the plane.
  Our work generalizes work of Lewis and coauthors when the measure is $p$
harmonic and also for $p=2$, the well known theorem of Makarov regarding the
Hausdorff dimension of harmonic measure relative to a point in a simply
connected domain.


title:
Spin transport parameters in metallic multilayers determined by
  ferromagnetic resonance measurements of spin pumping

abstract:
  We measured spin transport in nonferromagnetic (NM) metallic multilayers from
the contribution to damping due to spin pumping from a ferromagnetic Co90Fe10
thin film. The multilayer stack consisted of NM1/NM2/Co90Fe10(2 nm)/NM2/NM3
with varying NM materials and thicknesses. Using conventional theory for one
dimensional diffusive spin transport in metals, we show that the effective
damping due to spin pumping can be strongly affected by the spin transport
properties of each NM in the multilayer, which permits the use of damping
measurements to accurately determine the spin transport properties of the
various NM layers in the full five-layer stack. We find that due to its high
electrical resistivity, amorphous Ta is a poor spin conductor, in spite of a
short spin-diffusion length of 1.0 nm, and that Pt is an excellent spin
conductor by virtue of its low electrical resistivity and a spin diffusion
length of only 0.5 nm. Spin Hall effect measurements may have underestimated
the spin Hall angle in Pt by assuming a much longer spin diffusion length.


title:
Bright Ray-like Features in the Aftermath of CMEs: White Light vs UV
  Spectra

abstract:
  Current sheets are important signatures of magnetic reconnection in the
eruption of confined solar magnetic structures. Models of Coronal Mass
Ejections (CMEs) involve formation of a current sheet connecting the ejected
flux rope with the post eruption magnetic loops. Current sheets have been
identified in white light images of CMEs as narrow rays trailing the outward
moving CME core, and in ultraviolet spectra as narrow bright features emitting
the Fe XVIII line. In this work samples of rays detected in white light images
or in ultraviolet spectra have been analyzed. Temperatures, widths, and line
intensities of the rays have been measured, and their correlation to the CME
properties has been studied. The samples show a wide range of temperatures with
hot, coronal and cool rays. In some cases, the UV spectra support the
identification of rays as current sheets, but they show that some white light
rays are cool material from the CME core. In many cases, both hot and cool
material are present, but offset from each other along the UltraViolet
Coronagraph Spectrometer (UVCS) slit. We find that about 18% of the white light
rays show very hot gas consistent with the current sheet interpretation, while
about 23% show cold gas that we attribute to cool prominence material draining
back from the CME core. The remaining events have ordinary coronal
temperatures, perhaps because they have relaxed back to a quiescent state.


title: On a class of fully nonlinear elliptic equations on Hermitian manifolds

abstract:
  We derive a priori $C^2$ estimates for a class of complex Monge-Ampere type
equations on Hermitian manifolds. As an application we solve the Dirichlet
problem for these equations under the assumption of existence of a subsolution;
the existence result, as well as the second order boundary estimates, is new
even for bounded domains in $\bfC^n$.


title: The Color-Magnitude Diagram of the Globular Cluster M14

abstract:
  Using the SARA 0.9 meter telescope at Kitt Peak National Observatory (KPNO)
we obtained R images during the summer of 2010 and V images during the summer
of 2012 of the globular cluster M14. These images were analyzed using the
DAOPHOT/ALLFRAME package of Stetson (1987,1994) to create a preliminary
color-magnitude diagram (CMD) of M14. We have positively identified the
positions of 64 of the 112 known RR Lyrae stars on the CMD. We find
considerable spread in both the magnitudes and color of the RR Lyrae stars
indicating a significant amount of differential reddening on relatively small
scales. This is also seen in the giant branch which shows up to ~0.15 magnitude
spread in V-R color. We also found the median magnitude of the RR Lyrae stars
and hence the horizontal branch to be V=17.2.


title: Quantization of massive Weyl fields in vacuum

abstract:
  We briefly review the main methods for the description of massive Weyl fields
in vacuum. On the classical level we discuss Weyl fields expressed through
Grassmann variables as well as having spinors with commuting components. In
both approaches we quantize the system. We get the correct anticommutation
relations between creation and annihilation operators, which result in the
proper form of the total energy of the field. However, the commuting classical
Weyl fields require the new method of quantization.


title:
Remote implementation of partially unknown operations and its
  entanglement costs

abstract:
  We present the generalized version of Wang's protocol[A.M.Wang, Phys.Rev.A
74,032317 (2006)] for the remote implementation(sometimes referred to as
quantum remote control) of partially unknown quantum operations. The protocol
only requires no more than half of the entanglements used in Bidirectional
Quantum State Teleportation. We also propose a protocol for another form of
quantum remote control. It can remotely implement a unitary operation which is
a combination of the projective representations of a group. Moreover, we prove
that the Schmidt rank of the entanglements cannot not be less than the number
of controlled parameters of the operations, which for the first time gives a
lower bound on entanglement costs in remote implementation of quantum
operations.


title: Global CKM Fits with the Scan Method

abstract:
  We present results of a unitary triangle fit based on the scan method. This
frequentist approach employs Gaussian uncertainties for experimental
quantities, but makes no arbitrary assumptions about the distribution of
theoretical errors. Instead, we perform a large number of fits, scanning over
regions of plausible theory errors for each quantity, and retain those fits
meeting a specific confidence level criterion, thereby constraining the $\bar
\rho - \bar \eta $ plane using the standard input measurements (CKM matrix
elements, $\sin2 \beta, B^0_{d,s}$ mixing, $\epsilon_K$) as well as branching
fraction and \CP asymmetry measurements of B decays to $PP, PV, VV$, and $a_1
P$ final states to determine $\alpha$, $D^{(*)}K^{(*)}$ modes to determine
$\gamma$, and $D^{(*)}\pi$ and $D\rho$ modes to determine $2\beta +\gamma$. We
parameterize individual decay amplitudes in terms of color-allowed tree,
color-suppressed tree, penguin, singlet penguin, electroweak penguin, as well
as $W$-exchange and $W$-annihilation amplitudes. With this parameterization, we
obtain a good fit to the measured branching fractions and \CP asymmetries
within the Standard Model {\it ansatz}, with no new physics contributions. This
simultaneous fit allows us to determine the correlation between $\alpha$ and
$\beta$ as well as between $\gamma$ and $\beta$.


title: Quiver Hecke algebras and categorification

abstract:
  This is a brief introduction to the quiver Hecke algebras of Khovanov, Lauda
and Rouquier, emphasizing their application to the categorification of quantum
groups. The text is based on lectures given by the author at the ICRA workshop
in Bielefeld in August, 2012.


title: Fixed point adjunctions for equivariant module spectra

abstract:
  We consider the Quillen adjunction between fixed points and inflation in the
context of equivariant module spectra over equivariant ring spectra, and give
numerous examples including some based on geometric fixed points and some on
the Eilenberg-Moore spectral sequence. These results were originally presented
as part of our equivalence between rational torus-equivariant spectra and an
algebraic model in arXiv:1101.2511. However, the present results apply in many
other interesting cases explored here, which are not rational and where the
ambient group is not a torus. The material in arXiv:1101.2511v3 will be revised
to refer to this paper.


title:
Groups of two galaxies in SDSS: implications of colours on star
  formation quenching time-scales

abstract:
  We have devised a method to select galaxies that are isolated in their dark
matter halo (N=1 systems) and galaxies that reside in a group of exactly two
(N=2 systems). Our N=2 systems are widely-separated (up to
$\sim$\,200\,$h^{-1}$\,kpc), where close galaxy-galaxy interactions are not
dominant. We apply our selection criteria to two volume-limited samples of
galaxies from SDSS DR6 with $M_{r}-5 \log_{10} h \leq$ -19 and -20 to study the
effects of the environment of very sparse groups on galaxy colour. For
satellite galaxies in a group of two, we find a red excess attributed to star
formation quenching of 0.15\,$\pm$\,0.01 and 0.14\,$\pm$\,0.01 for the -19 and
-20 samples, respectively, relative to isolated galaxies of the same stellar
mass. Assuming N=1 systems are the progenitors of N=2 systems, an
immediate-rapid star formation quenching scenario is inconsistent with these
observations. A delayed-then-rapid star formation quenching scenario with a
delay time of 3.3 and 3.7\,Gyr for the -19 and -20 samples, respectively,
yields a red excess prediction in agreement with the observations. The
observations also reveal that central galaxies in a group of two have a slight
blue excess of 0.06\,$\pm$\,0.02 and 0.02\,$\pm$\,0.01 for the -19 and -20
samples, respectively, relative to N=1 populations of the same stellar mass.
Our results demonstrate that even the environment of very sparse groups of
luminous galaxies influence galaxy evolution and in-depth studies of these
simple systems are an essential step towards understanding galaxy evolution in
general.


title: Towards a faster symbolic aggregate approximation method

abstract:
  The similarity search problem is one of the main problems in time series data
mining. Traditionally, this problem was tackled by sequentially comparing the
given query against all the time series in the database, and returning all the
time series that are within a predetermined threshold of that query. But the
large size and the high dimensionality of time series databases that are in use
nowadays make that scenario inefficient. There are many representation
techniques that aim at reducing the dimensionality of time series so that the
search can be handled faster at a lower-dimensional space level. The symbolic
aggregate approximation (SAX) is one of the most competitive methods in the
literature. In this paper we present a new method that improves the performance
of SAX by adding to it another exclusion condition that increases the exclusion
power. This method is based on using two representations of the time series:
one of SAX and the other is based on an optimal approximation of the time
series. Pre-computed distances are calculated and stored offline to be used
online to exclude a wide range of the search space using two exclusion
conditions. We conduct experiments which show that the new method is faster
than SAX.


title: The wind of the M-type AGB star RT Virginis probed by VLTI/MIDI

abstract:
  We study the circumstellar environment of the M-type AGB star RT Vir using
mid-infrared high spatial resolution observations from the ESO-VLTI focal
instrument MIDI. The aim of this study is to provide observational constraints
on theoretical prediction that the winds of M-type AGB objects can be driven by
photon scattering on iron-free silicate grains located in the close environment
(about 2 to 3 stellar radii) of the star. We interpreted
spectro-interferometric data, first using wavelength-dependent geometric
models. We then used a self-consistent dynamic model atmosphere containing a
time-dependent description of grain growth for pure forsterite dust particles
to reproduce the photometric, spectrometric, and interferometric measurements
of RT Vir. Since the hydrodynamic computation needs stellar parameters as
input, a considerable effort was first made to determine these parameters. MIDI
differential phases reveal the presence of an asymmetry in the stellar
vicinity. Results from the geometrical modeling give us clues to the presence
of aluminum and silicate dust in the close circumstellar environment (< ~5
stellar radii). Comparison between spectro-interferometric data and a
self-consistent dust-driven wind model reveals that silicate dust has to be
present in the region between 2 to 3 stellar radii to reproduce the 59 and 63 m
baseline visibility measurements around 9.8 micron. This gives additional
observational evidence in favor of winds driven by photon scattering on
iron-free silicate grains located in the close vicinity of an M-type star.
However, other sources of opacity are clearly missing to reproduce the 10-13
micron visibility measurements for all baselines. This study is a first attempt
to understand the wind mechanism of M-type AGB stars by comparing photometric,
spectrometric, and interferometric measurements with state-of-the-art,
self-consistent dust-driven wind models. The agreement of the dynamic model
atmosphere with interferometric measurements in the 8-10 micron spectral region
gives additional observational evidence that the winds of M-type stars can be
driven by photon scattering on iron-free silicate grains. Finally, a larger
statistical study and progress in advanced self-consistent 3D modeling are
still required to solve the remaining problems.


title: Spike detection from inaccurate samplings

abstract:
  This article investigates the support detection problem using the LASSO
estimator in the space of measures. More precisely, we study the recovery of a
discrete measure (spike train) from few noisy observations (Fourier samples,
moments...) using an $\ell_{1}$-regularization procedure. In particular, we
provide an explicit quantitative localization of the spikes.


title: Stein COnsistent Risk Estimator (SCORE) for hard thresholding

abstract:
  In this work, we construct a risk estimator for hard thresholding which can
be used as a basis to solve the difficult task of automatically selecting the
threshold. As hard thresholding is not even continuous, Stein's lemma cannot be
used to get an unbiased estimator of degrees of freedom, hence of the risk. We
prove that under a mild condition, our estimator of the degrees of freedom,
although biased, is consistent. Numerical evidence shows that our estimator
outperforms another biased risk estimator.


title:
Distillation of Multi-Party Non-Locality With and Without Partial
  Communication

abstract:
  Non-local correlations are one of the most fascinating consequences of
quantum physics from the point of view of information: Such correlations,
although not allowing for signaling, are unexplainable by pre-shared
information. The correlations have applications in cryptography, communication
complexity, and sit at the very heart of many attempts of understanding quantum
theory -- and its limits -- better in terms of classical information. In these
contexts, the question is crucial whether such correlations can be distilled,
i.e., whether weak correlations can be used for generating (a smaller amount
of) stronger. Whereas the question has been studied quite extensively for
bipartite correlations (yielding both pessimistic and optimistic results), only
little is known in the multi-partite case. We show that a natural
generalization of the well-known Popsecu-Rohrlich box can be distilled, by an
adaptive protocol, to the algebraic maximum. We use this result further to show
that a much bigger class of correlations, including all purely three-partite
correlations, can be distilled from arbitrarily weak to maximal strength with
partial communication, i.e., using only a subset of the channels required for
the creation of the same correlation from scratch. In other words, we show that
arbitrarily weak non-local correlations can have a "communication value" in the
context of the generation of maximal non-locality.


title: Modular forms, de Rham cohomology and congruences

abstract:
  In this paper we show that Atkin and Swinnerton-Dyer type of congruences hold
for weakly modular forms (modular forms that are permitted to have poles at
cusps). Unlike the case of original congruences for cusp forms, these
congruences are nontrivial even for congruence subgroups. On the way we provide
an explicit interpretation of the de Rham cohomology groups associated to
modular forms in terms of "differentials of the second kind". As an example, we
consider the space of cusp forms of weight 3 on a certain genus zero quotient
of Fermat curve X^N+Y^N=Z^N. We show that the Galois representation associated
to this space is Grossencharacter of a cyclotomic field $\Q(\zeta_N)$.
Moreover, for N=5 the space does not admit a "$p$-adic Hecke eigenbasis" for
(non-ordinary) primes $p\equiv 2,3 \pmod{5}$, which provides a counterexample
for original Atkin and Swinnerton-Dyer speculaction (see [2], [7], [8]).


title: Pricing Using a Homogeneously Saturated Equation

abstract:
  A homogeneously saturated equation for the time development of the price of a
financial asset is presented and investigated for the pricing of European call
options using noise that is distributed as a Student's t-distribution. In the
limit that the saturation parameter of the equation equals zero, the standard
model of geometric motion for the price of an asset is obtained. The
homogeneously saturated equation for the price of an asset is similar to a
simple equation for the output of a homogeneously broadened laser. The
homogeneously saturated equation tends to limit the range of returns and thus
seems to be realistic.
  Fits to linear returns obtained from the adjusted closing values for the S&P
500 index were used to obtain best-fit parameters for Student's t-distributions
and for normal distributions, and these fits were used to price options, and to
compare approaches to modelling prices.
  This work has value in understanding the pricing of assets and of European
call options.


title: How do you know your spreadsheet is right?

abstract: Principles, Techniques and Practice of Spreadsheet Style