title: Classification of automatic software build methods

abstract:
  The process of creating working software from source code and other
components (like libraries, database files, etc.) is called "software build".
Apart from linking and compiling, it can include other steps like automated
testing, static code analysis, documentation generation, deployment and other.
All that steps can be automated using a build description of some sort (e.g.
script). This article classifies the automatic software build processes
beginning at build script and reaching the various types of continuous
integration.


title: Unitary representations of N-conformal Galilei group

abstract:
  All unitary irreducible representations of centrally extended (N-odd)
N-conformal Galilei group are constructed. The "on-shell" action of the group
is derived and shown to coincide, in special but most important case, with that
obtained in: J. Gomis, K. Kamimura, Phys. Rev. {\bf D85} (2012), 045023.


title:
Zero-sum repeated games: Counterexamples to the existence of the
  asymptotic value and the conjecture
  $\operatorname{maxmin}=\operatorname{lim}v_n$

abstract:
  Mertens [In Proceedings of the International Congress of Mathematicians
(Berkeley, Calif., 1986) (1987) 1528-1577 Amer. Math. Soc.] proposed two
general conjectures about repeated games: the first one is that, in any
two-person zero-sum repeated game, the asymptotic value exists, and the second
one is that, when Player 1 is more informed than Player 2, in the long run
Player 1 is able to guarantee the asymptotic value. We disprove these two
long-standing conjectures by providing an example of a zero-sum repeated game
with public signals and perfect observation of the actions, where the value of
the $\lambda$-discounted game does not converge when $\lambda$ goes to 0. The
aforementioned example involves seven states, two actions and two signals for
each player. Remarkably, players observe the payoffs, and play in turn.


title: 21 cm Angular Spectrum of Cosmic String Loops

abstract:
  The 21 cm signatures induced by moving cosmic string loops are investigated.
Moving cosmic string loops seed filamentary nonlinear objects. We analytically
evaluate the differential 21 cm brightness temperature from these objects. We
show that the brightness temperature reaches 200 mK for a loop whose tension is
about the current upper limit, $G\mu\sim10^{-7}$. We also calculate the angular
power spectrum, assuming scaling in loop distribution. We find that the angular
power spectrum for $G\mu>10^{-8}$ at $z=30$ or $G\mu>10^{-10}$ at $z=20$ can
dominate the spectrum of the primordial density fluctuations. Finally we show
that a future SKA-like observation has the potential to detect the power
spectrum due to loops with $G\mu=10^{-8}$ at $z=20$.


title: Exterior Critical Series of Persistence Modules

abstract:
  The persistence barcode is a well-established complete discrete invariant for
finitely generated persistence modules [5] [1]. Its definition, however, does
not extend to multi- dimensional persistence modules. In this paper, we
introduce a new discrete invariant: the exterior critical series. This
invariant is complete in the one-dimensional case and can be defined for
multi-dimensional persistence modules, like the rank invariant [2]. However,
the exterior critical series can detect some features that are not captured by
the rank invariant.


title:
Computational molecular engineering as an emerging technology in process
  engineering

abstract:
  The present level of development of molecular force field methods is assessed
from the point of view of simulation-based engineering, outlining the immediate
perspective for further development and highlighting the newly emerging
discipline of Computational Molecular Engineering (CME) which makes basic
research in soft matter physics fruitful for industrial applications. Within
the coming decade, major breakthroughs can be reached if a research focus is
placed on processes at interfaces, combining aspects where an increase in the
accessible length and time scales due to massively parallel high-performance
computing will lead to particularly significant improvements.


title: Gaussian tripartite entanglement out of equilibrium

abstract:
  The stationary multipartite entanglement between three interacting harmonic
oscillators subjected to decoherence is analyzed in the largely unexplored
non-equilibrium strong dissipation regime. We compute the exact asymptotic
Gaussian state of the system and elucidate its separability properties,
qualitatively assessing the regions of the space of parameters in which fully
inseparable states are generated. Interestingly, the sharing structure of
bipartite entanglement is seen to degrade as dissipation increases even for
very low temperatures, at which the system approaches its ground state. We also
find that establishing stationary energy currents across the harmonic chain
does not correspond with the build-up of biseparable steady states, which
relates instead just to the relative intensity of thermal fluctuations.


title: On Weingarten transformations of hyperbolic nets

abstract:
  Weingarten transformations which, by definition, preserve the asymptotic
lines on smooth surfaces have been studied extensively in classical
differential geometry and also play an important role in connection with the
modern geometric theory of integrable systems. Their natural discrete analogues
have been investigated in great detail in the area of (integrable) discrete
differential geometry and can be traced back at least to the early 1950s. Here,
we propose a canonical analogue of (discrete) Weingarten transformations for
hyperbolic nets, that is, C^1-surfaces which constitute hybrids of smooth and
discrete surfaces "parametrized" in terms of asymptotic coordinates. We prove
the existence of Weingarten pairs and analyse their geometric and algebraic
properties.


title:
Abelian Hopfions of the CP^n model on R^{2n+1} and a fractionally
  powered topological lower bound

abstract:
  Regarding the Skyrme-Faddeev model on $\mathbb R^3$ as a $\mathbb C \mathbb
P^1$ sigma model, we propose $\mathbb C \mathbb P^n$ sigma models on $\mathbb
R^{2n+1}$ as generalisations which may support finite energy Hopfion solutions
in these dimensions. The topological charge stabilising these field
configurations is the Chern-Simons charge, namely the volume integral of the
Chern-Simons density which has a local expression in terms of the composite
connection and curvature of the CP^n field. It turns out that subject to the
sigma model constraint, this density is a total divergence. We prove the
existence of a topological lower bound on the energy, which, as in the
Vakulenko-Kapitansky case in R^3, is a fractional power of the topological
charge, depending on $n$. The numerical construction of the simplest ring
shaped un-knot Hopfion on R^5 is also discussed.


title: Explicit description of spherical rigid hypersurfaces in C^2

abstract:
  We provide an explicit description of all rigid hypersurfaces that are
equivalent to a Heisenberg sphere. These hypersurfaces are determined by 4 real
parameters. The defining equations of the rigid spheres can also be viewed as
the complete solution of a non-linear PDE that expresses the vanishing Cartan
curvature condition for rigid hypersurfaces.


title: Reliable Reception of Wireless Metering Data with Protocol Coding

abstract:
  Stationary collectors reading wireless, battery powered smart meters, often
operate in harsh channel conditions to cut network installation cost to a
minimum, challenging the individual link to each meter. The desired performance
measure is reliable reception of at least some data from as many as possible
meters, rather than increasing the fraction of received packets from one meter.
As a first step for improving reliable reception, and motivated by the recent
revision of Wireless M-Bus, we propose the use of a deterministic packet
transmission interval to group packets from the same meter. We derive the
probability of falsely pairing packets from different senders in the simple
case of no channel errors, and show through simulation and data from an
experimental deployment the probability of false pairing with channel errors.
The pairing is an essential step towards recovery of metering data from as many
as possible meters under harsh channel conditions. From the experiment we find
that more than 15% of all conducted pairings are between two erroneous packets,
which sets an upper bound on the number of additional meters that can be
reliably recovered.


title:
Errors and their mitigation at the Kirchhoff-law-Johnson-noise secure
  key exchange

abstract:
  A method to quantify the error probability at the Kirchhoff-law-Johnson-noise
(KLJN) secure key exchange is introduced. The types of errors due to
statistical inaccuracies in noise voltage measurements are classified and the
error probability is calculated. The most interesting finding is that the error
probability decays exponentially with the duration of the time window of single
bit exchange. The results indicate that it is feasible to have so small error
probabilities of the exchanged bits that error correction algorithms are not
required. The results are demonstrated with practical considerations.


title:
Magnetohydrostatic equilibrium. I: Three-dimensional open magnetic flux
  tube in the stratified solar atmosphere

abstract:
  A single open magnetic flux tube spanning the solar photosphere (solar radius
R) and the lower corona (R + 10 Mm) is modelled in magnetohydrostatic
equilibrium within a realistic stratified atmosphere subject to solar gravity.
Such flux tubes are observed to remain relatively stable for up to a day or
more, and it is our aim to apply the model as the background condition for
numerical studies of energy transport mechanisms from the surface to the
corona. We solve analytically an axially symmetric 3D structure for the model,
with magnetic field strength, plasma density, pressure and temperature all
consistent with observational and theoretical estimates. The self similar
construction ensures the magnetic field is divergence free. The equation of
pressure balance for this particular set of flux tubes can be integrated
analytically to find the pressure and density corrections required to preserve
the magnetohydrostatic equilibrium. The model includes a number of free
parameters, which makes the solution applicable to a variety of other physical
problems and it may therefore be of more general interest.


title: The Stability and Charge Carriers in Bilayer Silicene

abstract:
  The structure optimization, phonon, and ab initio finite temperature
molecular dynamics calculations have been performed to predict that bilayer
silicene has stable structure with AB stacking geometry and is more favorable
energetically to synthesize than monolayer silicene, a two-dimensional
honeycomb lattice with buckled geometry. Marvellously, its electronic bands
show that the charge carriers behave like relativistic Dirac fermions with
linear energy dispersions near the K points. An insightful analysis has been
presented to understand the low-energy electronic excitations based on
tight-binding approximation, and we suggest that the component of sp3
hybridization in the buckled geometry blocks the interlayer hopping, so the
linear dispersion can be preserved.


title: Non-singular quantum-inspired gravitational collapse

abstract:
  We consider general relativistic homogeneous gravitational collapses for dust
and radiation. We show that replacing the density profile with an effective
density justified by some quantum gravity framework leads to the avoidance of
the final singularity. The effective density acts on the collapsing cloud by
introducing an isotropic pressure, which is negligible at the beginning of the
collapse and becomes negative and dominant in the strong field regime. Event
horizons never form and therefore the outcome of the collapse is not a black
hole, in the sense that there are no regions causally disconnected from future
null infinity. Apparent horizons form when the mass of the object exceeds a
critical value, disappear when the matter density approaches an upper bound and
gravity becomes very weak (asymptotic freedom regime), form again after the
bounce as a consequence of the decrease in the matter density, and eventually
disappear when the density becomes too low and the matter is radiated away. The
possibility of detecting radiation coming from the high density region of a
collapsing astrophysical object in which classically there would be the
creation of a singularity could open a new window to experimentally test
theories of quantum gravity.


title:
Star formation properties in the Local Volume galaxies via $H\alpha$ and
  FUV fluxes

abstract:
  A distance-limited sample of 869 objects from the Updated Nearby Galaxy
Catalog is used to characterize the star formation status of the Local Volume
population. We present a compiled list of 1217 star formation rate (SFR)
estimates for 802 galaxies within 11 Mpc from us, derived from the H-alpha
imaging surveys and GALEX far-ultraviolet survey. We briefly discuss some basic
scaling relations between SFR and luminosity, morphology, HI-mass, surface
brightness, as well as environment of the galaxies. About 3/4 of our sample
consist of dwarf galaxies, for which we offer a more refined classification. We
note that the specific star formation rate of nearly all luminous and dwarf
galaxies does not exceed the maximum value: $\log(SFR/L_K) = -9.4$ [yr$^{-1}$].
The bulk of spiral and blue dwarf galaxies have enough time to generate their
stellar mass during the cosmological time, $T_0$, with the observed SFRs. They
dispose of a sufficient amount of gas to support their present SFRs over the
next $T_0$ term. We note that only a minor part of BCD, Im, and Ir galaxies
(about 1/20) proceeds in a mode of vigorous star-burst activity. In general,
the star formation history of spiral and blue dwarf galaxies is mainly driven
by their internal processes. The present SFRs of E, S0 and dSph galaxies are
typically (1/30 - 1/300) of their former activity.


title:
Efficient inference about the tail weight in multivariate Student $t$
  distributions

abstract:
  We propose a new testing procedure about the tail weight parameter of
multivariate Student $t$ distributions by having recourse to the Le Cam
methodology. Our test is asymptotically as efficient as the classical
likelihood ratio test, but outperforms the latter by its flexibility and
simplicity: indeed, our approach allows to estimate the location and scatter
nuisance parameters by any root-$n$ consistent estimators, hereby avoiding
numerically complex maximum likelihood estimation. The finite-sample properties
of our test are analyzed in a Monte Carlo simulation study, and we apply our
method on a financial data set. We conclude the paper by indicating how to use
this framework for efficient point estimation.


title:
Symmetric and asymmetric solitons in dual-core couplers with competing
  quadratic and cubic nonlinearities

abstract:
  We consider the model of a dual-core spatial-domain coupler with chi^(2) and
chi^(3) nonlinearities acting in two parallel cores. We construct families of
symmetric and asymmetric solitons in the system with self-defocusing chi^(3)
terms, and test their stability. The transition from symmetric to asymmetric
soliton branches, and back to the symmetric ones proceeds via a bifurcation
loop. A pair of stable asymmetric branches emerge from the symmetric family via
a supercritical bifurcation; eventually, the asymmetric branches merge back
into the symmetric one through a reverse bifurcation. The existence of the loop
is explained by means of an extended version of the cascading approximation for
the chi^(2) interaction, which takes into regard the XPM part of the chi(3)
interaction. When the inter-core coupling is weak, the bifurcation loop
features a concave shape, with the asymmetric branches losing their stability
at the turning points. In addition to the two-color solitons, which are built
of the fundamental-frequency (FF) and second-harmonic (SH) components, in the
case of the self-focusing chi^(3) nonlinearity we also consider single-color
solitons, which contain only the SH component, but may be subject to the
instability against FF perturbations. Asymmetric single-color solitons are
always unstable, whereas the symmetric ones are stable, provided that they do
not coexist with two-color counterparts. Collisions between tilted solitons are
studied too.


title: Relic Vector Field and CMB Large Scale Anomalies

abstract:
  We study the most general effects of relic vector fields on the inflationary
background and density perturbations. Such effects are observable if the number
of inflationary e-folds is close to the minimum requirement to solve the
horizon problem. We show that this can potentially explain two CMB large scale
anomalies: the quadrupole-octopole alignment and the quadrupole power
suppression. We discuss its effect on the parity anomaly. We also provide
analytical template for more detailed data comparison.


title:
Alpha-reliable combined mean traffic equilibrium model with stochastic
  travel times

abstract:
  Based on the reliability budget and percentile travel time (PTT) concept, a
new travel time index named combined mean travel time (CMTT) under stochastic
traffic network was proposed. CMTT here was defined as the convex combination
of the conditional expectations of PTT-below and PTT-excess travel times. The
former was designed as a risk-optimistic travel time index, and the latter was
a risk-pessimistic one. Hence, CMTT was able to describe various routing
risk-attitudes. The central idea of CMTT was comprehensively illustrated and
the difference among the existing travel time indices was analysed. The
Wardropian combined mean traffic equilibrium (CMTE) model was formulated as a
variational inequality and solved via an alternating direction algorithm
nesting extra-gradient projection process. Some mathematical properties of CMTT
and CMTE model were rigorously proved. In the end, a numerical example was
performed to characterize the CMTE network. It is founded that that
risk-pessimism is of more benefit to a modest (or low) congestion and risk
network, however, it changes to be risk-optimism for a high congestion and risk
network.


title:
Extended Czjzek model applied to NMR parameter distributions in sodium
  metaphosphate glass

abstract:
  The Extended Czjzek Model (ECM) is applied to the distribution of NMR
parameters of a simple glass model (sodium metaphosphate, $\mathrm{NaPO_3}$)
obtained by Molecular Dynamics (MD) simulations. Accurate NMR tensors, Electric
Field Gradient (EFG) and Chemical Shift Anisotropy (CSA), are calculated from
Density Functional Theory (DFT) within the well-established PAW/GIPAW
framework. Theoretical results are compared to experimental high-resolution
solid-state NMR data and are used to validate the considered structural model.
The distributions of the calculated coupling constant $C_Q\propto |V_{zz}|$ and
of the asymmetry parameter $\eta_Q$ that characterize the quadrupolar
interaction are discussed in terms of structural considerations with the help
of a simple point charge model. Finally, the ECM analysis is shown to be
relevant for studying the distribution of CSA tensor parameters and gives new
insight into the structural characterization of disordered systems by
solid-state NMR.


title:
Isospin asymmetries in $B\to (K^*,\rho) \gamma/ l^+ l^-$ and $B \to K
  l^+ l^-$ in and beyond the Standard Model

abstract:
  We compute the isospin asymmetries in $B \to (K^*,\rho) \gamma$ and $B\to
(K,K^*,\rho) l^+l^-$ for low lepton pair invariant mass $q^2$, within the
Standard Model (SM) and beyond the SM (BSM) in a generic dimension six operator
basis. Within the SM the CP-averaged isospin asymmetries for $B \to
(K,K^*,\rho) ll$, between $1{\rm GeV}^2 \leq q^2 \leq 4m_c^2$, are predicted to
be small (below 1.5%) though with significant cancellation. In the SM the
non-CP averaged asymmetries for $B \to \rho ll$ deviate by $\approx \pm 5%$
from the CP-averaged ones. We provide physical arguments, based on resonances,
of why isospin asymmetries have to decrease for large $q^2$ (towards the
endpoint). Two types of isospin violating effects are computed: ultraviolet
(UV) isospin violation due to differences between operators coupling to up and
down quarks, and infrared (IR) isospin violation where a photon is emitted from
the spectator quark and is hence proportional to the difference between the up-
and down-quark charges. These isospin violating processes may be subdivided
into weak annihilation (WA), quark loop spectator scattering (QLSS) and a
chromomagnetic contribution. Furthermore we discuss generic selection rules
based on parity and angular momentum for the $B \to Kll$ transition as well as
specific selection rules valid for WA at leading order in the strong coupling
constant. We clarify that the relation between the $K$ and the longitudinal
part of the $K^*$ only holds for leading twist and for left-handed currents. In
general the $B \to \rho ll$ and $B \to K^*ll$ isospin asymmetries are
structurally different yet the closeness of $\alpha_{\rm CKM}$ to ninety
degrees allows us to construct a (quasi) null test for the SM out of the
respective isospin symmetries. We provide an update on ${\cal B}(B^0 \to
K^{*0}\gamma)/{\cal B}(B_s \to \phi \gamma)$ which is sensitive to WA.


title:
Self-consistent field predictions for quenched spherical biocompatible
  triblock copolymer micelles

abstract:
  We have used the Scheutjens-Fleer self-consistent field (SF-SCF) method to
predict the self-assembly of triblock copolymers with a solvophilic middle
block and sufficiently long solvophobic outer blocks. We model copolymers
consisting of polyethylene oxide (PEO) as solvophilic block and
poly(lactic-co-glycolic) acid (PLGA) or poly({\ko}-caprolactone) (PCL) as
solvophobic block. These copolymers form structurally quenched spherical
micelles provided the solvophilic block is long enough. Predictions are
calibrated on experimental data for micelles composed of PCL-PEO-PCL and
PLGA-PEO-PLGA triblock copolymers prepared via the nanoprecipitation method. We
establish effective interaction parameters that enable us to predict various
micelle properties such as the hydrodynamic size, the aggregation number and
the loading capacity of the micelles for hydrophobic species that are
consistent with experimental finding.


title: String theory at the tip of the cigar

abstract:
  In arXiv:1208.3930 we argued that string theory at the tip of the cigar
geometry, obtained by a Wick rotation of the Schwarzschild background, exhibits
unexpected features that include degrees of freedom that are confined to the
tip. Using the exact worldsheet description of near extremal NS5-branes we
further study string theory at the tip of the cigar and find more evidence to
its surprising properties.


title:
Amplitude and phase effects in Josephson qubits driven by a biharmonic
  electromagnetic field

abstract:
  We investigate the amplitude and phase effects of qubit dynamics and
excited-state population under the influence of a biharmonic control field. It
is demonstrated that the biharmonic driving field can have a significant effect
on the behavior of quasi-energy level crossing as well as on multiphoton
transitions. Also, the interference pattern for the populations of qubit
excited states is sensitive to the signal parameters. We discuss the
possibility of using these effects for manipulating qubit states and
calibrating nanosecond pulses.


title: Mining top-k granular association rules for recommendation

abstract:
  Recommender systems are important for e-commerce companies as well as
researchers. Recently, granular association rules have been proposed for
cold-start recommendation. However, existing approaches reserve only globally
strong rules; therefore some users may receive no recommendation at all. In
this paper, we propose to mine the top-k granular association rules for each
user. First we define three measures of granular association rules. These are
the source coverage which measures the user granule size, the target coverage
which measures the item granule size, and the confidence which measures the
strength of the association. With the confidence measure, rules can be ranked
according to their strength. Then we propose algorithms for training the
recommender and suggesting items to each user. Experimental are undertaken on a
publicly available data set MovieLens. Results indicate that the appropriate
setting of granule can avoid over-fitting and at the same time, help obtaining
high recommending accuracy.


title:
The tensor hypercontracted parametric reduced density matrix algorithm:
  coupled-cluster accuracy with O(r^4) scaling

abstract:
  Tensor hypercontraction is a method that allows the representation of a
high-rank tensor as a product of lower-rank tensors. In this paper, we show how
tensor hypercontraction can be applied to both the electron repulsion integral
(ERI) tensor and the two-particle excitation amplitudes used in the parametric
reduced density matrix (pRDM) algorithm. Because only O(r) auxiliary functions
are needed in both of these approximations, our overall algorithm can be shown
to scale as O(r4), where r is the number of single-particle basis functions. We
apply our algorithm to several small molecules, hydrogen chains, and alkanes to
demonstrate its low formal scaling and practical utility. Provided we use
enough auxiliary functions, we obtain accuracy similar to that of the
traditional pRDM algorithm, somewhere between that of CCSD and CCSD(T).


title:
Improving predictive power of physically based rainfall-induced shallow
  landslide models: a probabilistic approach

abstract:
  Distributed models to forecast the spatial and temporal occurrence of
rainfall-induced shallow landslides are based on deterministic laws. These
models extend spatially the static stability models adopted in geotechnical
engineering, and adopt an infinite-slope geometry to balance the resisting and
the driving forces acting on the sliding mass. An infiltration model is used to
determine how rainfall changes pore-water conditions, modulating the local
stability/instability conditions. A problem with the operation of the existing
models lays in the difficulty in obtaining accurate values for the several
variables that describe the material properties of the slopes. The problem is
particularly severe when the models are applied over large areas, for which
sufficient information on the geotechnical and hydrological conditions of the
slopes is not generally available. To help solve the problem, we propose a
probabilistic Monte Carlo approach to the distributed modeling of
rainfall-induced shallow landslides. For the purpose, we have modified the
Transient Rainfall Infiltration and Grid-Based Regional Slope-Stability
Analysis (TRIGRS) code. The new code (TRIGRS-P) adopts a probabilistic approach
to compute, on a cell-by-cell basis, transient pore-pressure changes and
related changes in the factor of safety due to rainfall infiltration.
Infiltration is modeled using analytical solutions of partial differential
equations describing one-dimensional vertical flow in isotropic, homogeneous
materials. Both saturated and unsaturated soil conditions can be considered.
TRIGRS-P copes with the natural variability inherent to the mechanical and
hydrological properties of the slope materials by allowing values of the TRIGRS
model input parameters to be sampled randomly from a given probability
distribution. [..]

categories: physics.geo-ph physics.ao-ph physics.comp-ph physics.data-an


title: The galaxy population of the complex cluster system Abell 3921

abstract:
  We present a spectrophotometric analysis of the galaxy pop. in the area of
the merging cluster Abell 3921 at redshift 0.093. We investigate the impact of
the complex cluster environment on galaxy properties such as morphology or star
formation rate. We combine multi-object spectroscopy from the 2dF spectrograph
with optical imaging taken with the ESO WFI. We carry out a redshift analysis
and determine cluster velocity dispersions using biweight statistics. Applying
a Dressler-Shectman (DS-)test we seek evidence for cluster substructure.
Cluster and field galaxies are investigated with respect to [OII] and H{\alpha}
equivalent width, SFR and morphological descriptors such as concentration index
and Gini coefficient. We study these cluster galaxy properties as a function of
clustercentric distance and investigate the spatial distribution of various
galaxy types. Applying the DS-test we find a 3rd component (A3921-C) in
addition to the two main subclusters (A3921-A and A3921-B) already known. The
re-determined mass ratio between the main components A and B is approx. 2:1.
Similar to prev. studies of galaxy clusters, we find that a large fraction of
the disk galaxies close to the cluster core show no detectable star formation.
These are likely systems that are quenched due to ram pressure stripping. We
also find quenched spirals at rather large distances of 3 to 4 Mpc from the
cluster core. A3921-C might be a group of galaxies falling onto the main
cluster components. We speculate that the unexpected population of quenched
spirals at large clustercentric radii in A3921-A and A3921-B might be an effect
of the ongoing cluster merger: shocks in the ICM might give raise to enhanced
ram pressure stripping and at least in part be the cause for the quenching of
star formation. These quenched spirals might be an interm. stage in the
morphological transformation of field spirals into cluster S0s.


title:
Bimodal substrate biasing to control \gamma-Al2O3 deposition during
  reactive magnetron sputtering

abstract:
  Al2O3 thin films have been deposited at substrate temperatures between
500{\deg}C to 600{\deg}C by reactive magnetron sputtering using an additional
arbitrary substrate bias to tailor the energy distribution of the incident
ions. The films were characterized by X-ray diffraction (XRD) and Fourier
transform infrared spectroscopy (FTIR). The film structure being amorphous,
nanocrystalline, or crystalline was correlated with characteristic ion energy
distributions. The evolving crystalline structure is connected with different
levels of displacements per atom (dpa) in the growing film as being derived
from TRIM simulations. The boundary between the formation of crystalline films
and amorphous or nanocrystalline films was at 0.9 dpa for a substrate
temperature of 500{\deg}C. This threshold shifts to 0.6 dpa for films grown at
550{\deg}C.


title: Switching of a single ferromagnetic layer driven by spin Hall effect

abstract:
  The magnetization switching of a thin ferromagnetic layer placed on top of a
heavy metal (such as Pt, Ta or W) driven by an in-plane current has been
observed in recent experiments. The magnetization dynamics of these processes
is studied in a full micromagnetic framework which takes into account the
transfer-torque from spin Hall effect due to the spin-orbit coupling.
Simulations indicate that the reversal occurs via nucleation of complex
magnetization patterns. In particular, magnetic bubbles appear during the
reversal of the magnetization in the perpendicular configuration while for the
in-plane configuration, nucleation of vortexes are observed.


title:
Memory in network flows and its effects on spreading dynamics and
  community detection

abstract:
  Random walks on networks is the standard tool for modelling spreading
processes in social and biological systems. This first-order Markov approach is
used in conventional community detection, ranking, and spreading analysis
although it ignores a potentially important feature of the dynamics: where flow
moves to may depend on where it comes from. Here we analyse pathways from
different systems, and while we only observe marginal consequences for disease
spreading, we show that ignoring the effects of second-order Markov dynamics
has important consequences for community detection, ranking, and information
spreading. For example, capturing dynamics with a second-order Markov model
allows us to reveal actual travel patterns in air traffic and to uncover
multidisciplinary journals in scientific communication. These findings were
achieved only by using more available data and making no additional
assumptions, and therefore suggest that accounting for higher-order memory in
network flows can help us better understand how real systems are organized and
function.


title: B ->K*ll: The New Frontier of New Physics searches in Flavor

abstract:
  The exclusive decay mode B ->K*ll has become one of the key players in the
search for New Physics in flavor. An increasing number of observables are being
studied experimentally, and with increasing precision. Its theoretical
description is well under control, and an interesting set of clean observables
have been identified, reducing further the theoretical uncertainties.
Model-independent analyses show that in the near future this mode will either
reveal NP through a pattern of correlated deviations from the SM, or pose very
stringent constraints on radiative and semileptonic operators.


title: Are the 'weak measurements' really measurements?

abstract:
  Weak measurements can be seen as an attempt at answering the 'Which way?'
question without destroying interference between the pathways involved. Unusual
mean values obtained in such measurements represent the response of a quantum
system to this 'forbidden' question, in which the 'true' composition of virtual
pathways is hidden from the observer. Such values indicate a failure of a
measurement where the uncertainty principle says it must fail, rather than
provide an additional insight into physical reality.


title: On the Dirac Monopole Mass Scale

abstract:
  It is shown, by a semi-classical argument, that the Dirac charge quantization
is still valid in the (classical) Born-Infeld electromagnetic theory. Then it
is possible to calculate Dirac's monopole mass in the framework of this theory,
which is not possible in Maxwell's theory. The existence of an upper limit for
the field intensities in this theory plays an important role in this proof.


title: Polarizations on limiting mixed Hodge structures

abstract:
  We construct a polarization on the relative log de Rham cohomology groups of
a projective log deformation. To this end, we study the behavior of weight and
Hodge filtrations under the cup product and construct a trace morphism for a
log deformation.


title:
Effect of Hole Shape on Spin-Wave Band Structure in One-Dimensional
  Magnonic Antidot Waveguide

abstract:
  We present the possibility of tuning the spin-wave band structure,
particularly the bandgaps in a nanoscale magnonic antidot waveguide by varying
the shape of the antidots. The effects of changing the shape of the antidots on
the spin-wave dispersion relation in a waveguide have been carefully monitored.
We interpret the observed variations by analysing the equilibrium magnetic
configuration and the magnonic power and phase distribution profiles during
spin-wave dynamics. The inhomogeneity in the exchange fields at the antidot
boundaries within the waveguide is found to play a crucial role in controlling
the band structure at the discussed length scales. The observations recorded
here will be important for future developments of magnetic antidot based
magnonic crystals and waveguides.


title:
On doubly periodic minimal surfaces in $\mathbb H^2 \times \mathbb R$
  with finite total curvature in the quotient space

abstract:
  In this paper we develop the theory of properly immersed minimal surfaces in
the quotient space $\mathbb H^2\times\mathbb R/G,$ where $G$ is a subgroup of
isometries generated by a vertical translation and a horizontal isometry in
$\mathbb H^2$ without fixed points. The horizontal isometry can be either a
parabolic translation along horocycles in $\mathbb H^2$ or a hyperbolic
translation along a geodesic in $\mathbb H^2.$ In fact, we prove that if a
properly immersed minimal surface in $\mathbb H^2\times\mathbb R/G$ has finite
total curvature then its total curvature is a multiple of $2\pi,$ and moreover,
we understand the geometry of the ends. These theorems hold true more generally
for properly immersed minimal surfaces in $M\times\mathbb S^1,$ where $M$ is a
hyperbolic surface with finite topology whose ends are isometric to one of the
ends of the above spaces $\mathbb H^2\times\mathbb R/G.$


title: Analytic formulas for complete hyperbolic affine spheres

abstract:
  We classify all regular three-dimensional convex cones which possess an
automorphism group of dimension at least two, and provide analytic expressions
for the complete hyperbolic affine spheres which are asymptotic to the
boundaries of these cones. The affine spheres are represented by explicit
hypersurface immersions into three-dimensional real space. The generic member
of the family of immersions is given by elliptic integrals.


title:
Two-loop low-energy effective actions in N=2 and N=4 three-dimensional
  SQED

abstract:
  We study two-loop Euler-Heisenberg effective actions in three-dimensional N=2
and N=4 supersymmetric quantum electrodynamics (SQED) without Chern-Simons
term. We find exact expressions for propagators of chiral superfields
interacting with slowly-varying N=2 gauge superfield. Using these propagators
we compute two-loop effective actions in the N=2 and N=4 SQED as the
functionals of superfield strengths and their covariant spinor derivatives. The
obtained effective actions contain new terms having no four-dimensional
analogs. As an application, we find two-loop quantum corrections to the moduli
space metric in the N=2 SQED.


title: A note on irreducible maps with several boundaries

abstract:
  We derive a formula for the generating function of d-irreducible bipartite
planar maps with several boundaries, i.e. having several marked faces of
controlled degrees. It extends a formula due to Collet and Fusy for the case of
arbitrary (non necessarily irreducible) bipartite planar maps, which we recover
by taking d=0. As an application, we obtain an expression for the number of
d-irreducible bipartite planar maps with a prescribed number of faces of each
allowed degree. Very explicit expressions are given in the case of maps without
multiple edges (d=2), 4-irreducible maps and maps of girth at least 6 (d=4).
Our derivation is based on a tree interpretation of the various encountered
generating functions.


title: Two measures of isochronal superposition

abstract:
  A liquid obeys isochronal superposition if its dynamics is invariant along
the isochrones in the thermodynamic phase diagram (the curves of constant
relaxation time). This paper introduces two quantitative measures of isochronal
superposition. The measures are used to test the following six liquids for
isochronal superposition: 1,2,6 hexanetriol, glycerol, polyphenyl ether,
diethyl phthalate, tetramethyl tetraphenyl trisiloxane, and dibutyl phthalate.
The latter four van der Waals liquids obey isochronal superposition to a higher
degree than the two hydrogen-bonded liquids. This is a predic- tion of the
isomorph theory, and it confirms findings by other groups.


title:
Computer-Assisted Proofs of Some Identities for Bessel Functions of
  Fractional Order

abstract:
  We employ computer algebra algorithms to prove a collection of identities
involving Bessel functions with half-integer orders and other special
functions. These identities appear in the famous Handbook of Mathematical
Functions, as well as in its successor, the DLMF, but their proofs were lost.
We use generating functions and symbolic summation techniques to produce new
proofs for them.


title:
Nature of the epidemic threshold for the
  susceptible-infected-susceptible dynamics in networks

abstract:
  We develop an analytical approach to the susceptible-infected-susceptible
(SIS) epidemic model that allows us to unravel the true origin of the absence
of an epidemic threshold in heterogeneous networks. We find that a delicate
balance between the number of high degree nodes in the network and the
topological distance between them dictates the existence or absence of such a
threshold. In particular, small-world random networks with a degree
distribution decaying slower than an exponential have a vanishing epidemic
threshold in the thermodynamic limit.


title:
Nouvelle approche de recommandation personnalisee dans les folksonomies
  basee sur le profil des utilisateurs

abstract:
  In folksonomies, users use to share objects (movies, books, bookmarks, etc.)
by annotating them with a set of tags of their own choice. With the rise of the
Web 2.0 age, users become the core of the system since they are both the
contributors and the creators of the information. Yet, each user has its own
profile and its own ideas making thereby the strength as well as the weakness
of folksonomies. Indeed, it would be helpful to take account of users' profile
when suggesting a list of tags and resources or even a list of friends, in
order to make a personal recommandation, instead of suggesting the more used
tags and resources in the folksonomy. In this paper, we consider users' profile
as a new dimension of a folksonomy classically composed of three dimensions
<users, tags, ressources> and we propose an approach to group users with
equivalent profiles and equivalent interests as quadratic concepts. Then, we
use such structures to propose our personalized recommendation system of users,
tags and resources according to each user's profile. Carried out experiments on
two real-world datasets, i.e., MovieLens and BookCrossing highlight encouraging
results in terms of precision as well as a good social evaluation.


title: Newton's Old Bucket Experiment and the Modern Liquid Telescope

abstract:
  In nature there are various pairs of observed phenomena and observing
scientific techniques which are elegantly coupled with each other. A very
general and well known example is the fact that the metal we use to build
telescopes were once built in stars by nuclear fusion. Hence in a fundamental
sense, stars themselves have helped us indirectly in observing them in great
detail. In this article I mention a bit more scientifically subtle and an even
more interesting example of such a pair which raises interesting thoughts about
an old experiment, its beauty and relevance in a very modern tool for
astronomy.


title:
Solvable model of quantum phase transitions and the
  symbolic-manipulation-based study of its multiply degenerate exceptional
  points and of their unfolding

abstract:
  The practical use of non-Hermitian (i.e., typically, PT-symmetric)
phenomenological quantum Hamiltonians is discussed as requiring an explicit
reconstruction of the {\em ad hoc} Hilbert-space metrics which would render the
time-evolution unitary. Just the N-dimensional matrix toy models Hamiltonians
are considered, therefore. For them, the matrix elements of alternative metrics
are constructed via solution of a coupled set of polynomial equations, using
the computer-assisted symbolic manipulations for the purpose. The feasibility
and some consequences of such a model-construction strategy are illustrated via
a discrete square well model endowed with multi-parametric
close-to-the-boundary real bidiagonal-matrix interaction. The degenerate
exceptional points marking the phase transitions are then studied numerically.
A way towards classification of their unfoldings in topologically
non-equivalent dynamical scenarios is outlined.


title: Magnetoplasmons in quasi-neutral epitaxial graphene nanoribbons

abstract:
  We present infrared transmission spectroscopy study of the inter-Landau-level
excitations in quasi-neutral epitaxial graphene nanoribbon arrays. We observed
a substantial deviation in energy of the $L_{0(-1)}$$\to$$L_{1(0)}$ transition
from the characteristic square root magnetic-field dependence of
two-dimensional graphene. This deviation arises from the formation of
upper-hybrid mode between the Landau level transition and the plasmon
resonance. In the quantum regime the hybrid mode exhibits a distinct dispersion
relation, markedly different from that expected for conventional
two-dimensional systems and highly doped graphene.


title: Tracing a relativistic Milky Way within the RAMOD measurement protocol

abstract:
  Advancement in astronomical observations and technical instrumentation
implies taking into account the general relativistic effects due the
gravitational fields encountered by the light while propagating from the star
to the observer. Therefore, data exploitation for Gaia-like space astrometric
mission (ESA, launch 2013) requires a fully relativistic interpretation of the
inverse ray-tracing problem, namely the development of a highly accurate
astrometric models in accordance with the geometrical environment affecting
light propagation itself and the precepts of the theory of measurement. This
could open a new rendition of the stellar distances and proper motions, or even
an alternative detection perspective of many subtle relativistic effects
suffered by light while it is propagating and subsequently recorded in the
physical measurements.


title: Learning subgaussian classes : Upper and minimax bounds

abstract:
  We obtain sharp oracle inequalities for the empirical risk minimization
procedure in the regression model under the assumption that the target Y and
the model F are subgaussian. The bound we obtain is sharp in the minimax sense
if F is convex. Moreover, under mild assumptions on F, the error rate of ERM
remains optimal even if the procedure is allowed to perform with constant
probability. A part of our analysis is a new proof of minimax results for the
gaussian regression model.


title: Locally quasi-convex topologies on the group of the integers

abstract:
  \noindent The most natural group topology on $\Z$ is the discrete one. There
are other well-known group topologies on $\Z$, like the $p$-adic, defined for
any prime number $p$. It is also an important group topology the weak topology
with respect to the group of homomorphisms from $\Z$ to the unit circle of the
complex plane; that is, the one defined by the characters and which is known as
"the Bohr topology" on $\Z$.
  \noindent In \cite{tesislorenzo}, it is proved that taking as a neighbourhood
basis at 0 the subsets $\{W_n\mid n\in\N\}$, defined by
$W_n:=\{k\in\Z\mid\forall x\in S$, $ k\cdot
x\in[-\frac{1}{4n},\frac{1}{4n}]+\Z\}$, where $S$ is a quasi-convex sequence in
$\T$, a group topology on $\Z$ is obtained, $\tau_S$. We know that the topology
$\tau_S$ is metrizable and locally quasi-convex.
  \noindent In this monograph we characterize convergent sequences in $\tau_S$,
for some $S\subset\T$. We give sufficient conditions on the elements of $\Z$ in
order that they belong to a neighbourhood $W_n$. For a fixed sequence $(b_n)$
of natural numbers, restricted to mild conditions, we have considered the
"linear topology associated" whose neighbourhood basis at 0 is $\{b_n\Z\mid
n\in\N\}$ and the "topology of uniform convergence" on
$S=\{\frac{1}{b_n}+\Z\mid n\in\N\}\subset\T$. We make a comparative study
between both classes of topologies.


title: Neutrino mass, mixing and discrete symmetries

abstract:
  Status of the discrete symmetry approach to explanation of the lepton masses
and mixing is summarized in view of recent experimental results, in particular,
establishing relatively large 1-3 mixing. The lepton mixing can originate from
breaking of discrete flavor symmetry $G_f$ to different residual symmetries
$G_{\ell}$ and $G_\nu$ in the charged lepton and neutrino sectors. In this
framework the {\it symmetry group condition} has been derived which allows to
get relations between the lepton mixing elements immediately without explicit
model building. The condition has been applied to different residual neutrino
symmetries $G_\nu$. For generic (mass independent) $G_\nu = {\bf Z}_2$ the
condition leads to two relations between the mixing parameters and fixes one
column of the mixing matrix. In the case of $G_\nu = {\bf Z}_2 \times {\bf
Z}_2$ the condition fixes the mixing matrix completely. The non-generic (mass
spectrum dependent) $G_\nu$ lead to relations which include mixing angles,
neutrino masses and Majorana phases. The symmetries $G_{\ell}$, $G_\nu$, $G_f$
are identified which lead to the experimentally observed values of the mixing
angles and allow to predict the CP phase.


title:
BEEC: An event generator for simulating the $B_c$ meson production at an
  $e^+e^-$ collider

abstract:
  The $B_c$ meson is a doubly heavy quark-antiquark bound state and carries
flavors explicitly, which provides a fruitful laboratory for testing potential
models and understanding the weak decay mechanisms for heavy flavors. In view
of the prospects in $B_c$ physics at the hadronic colliders as Tevatron and
LHC, $B_c$ physics is attracting more and more attention. It has been shown
that a high luminosity $e^+e^-$ collider running around the $Z^0$-peak is also
helpful for studying the properties of $B_c$ meson and has its own advantages.
For the purpose, we write down an event generator for simulating $B_c$ meson
production through $e^+e^-$ annihilation according to relevant publications. We
name it as BEEC, in which the color-singlet $S$-wave and $P$-wave
$(c\bar{b})$-quarkonium states together with the color-octet $S$-wave
$(c\bar{b})$-quarkonium states can be generated. BEEC can also be adopted to
generate the similar charmonium and bottomnium states via the semi-exclusive
channels $e^{+}+e^{-}\rightarrow |(Q\bar{Q})[n]\rangle +Q +\bar{Q}$ with $Q=b$
and $c$ respectively. To increase the simulation efficiency, we simplify the
amplitude as compact as possible by using the improved trace technology. BEEC
is a Fortran programme written in a PYTHIA-compatible format and is written in
a modularization structure, one may apply it to various situations or
experimental environments conveniently by using the GNU C compiler {\bf make}.
A method to improve the efficiency of generating unweighted events within
PYTHIA environment has been suggested. Moreover, BEEC will generate a standard
Les Houches Event data file that contains useful information of the meson and
its accompanying partons, which can be conveniently imported into PYTHIA to do
further hadronization and decay simulation.


title:
Exact calculation of current correlations and admittance in the
  fractional quantum Hall regime

abstract:
  In this work, we focus on the finite frequency current-current correlations
between edge states in a fractional quantum Hall two dimensional gas and on
their relations to the quantum admittance. Using a refermionization method, we
calculate these quantities within the same framework. Our results apply
whatever the values of backscattering amplitude, frequency, voltage and
temperature, allowing us to reach different regimes. Auto-correlations and
cross-correlations exhibit distinct frequency dependencies that we discuss in
detail.


title: Lattice point counting via Einstein metrics

abstract:
  We obtain a growth estimate for the number of lattice points inside any
Q-Gorenstein cone. Our proof uses the result of Futaki-Ono-Wang on
Sasaki-Einstein metric for the toric Sasakian manifold associated to the cone,
a Yau's inequality, and the Kawasaki-Riemann-Roch formula for orbifolds.


title:
Contrasting behavior of the structural and magnetic properties in Mn-
  and Fe-doped In$_2$O$_3$ films

abstract:
  We have observed room temperature ferromagnetism (FM) in In$_2$O$_3$ thin
films doped with either 5 at.% Mn or Fe, prepared by pulsed laser deposition
(PLD) at substrate temperatures ranging from 300 to 600$\,^{\circ}{\rm C}$. The
dependence of saturation magnetization on grain size was investigated for both
types of In$_2$O$_3$ films. It is revealed that, for the Mn-doped films, the
magnetization was largest with small grains, indicating the importance of grain
boundaries. In contrast, for Fe-doped films, the largest magnetization was
observed with large grains.


title: Secure Biometrics: Concepts, Authentication Architectures and Challenges

abstract:
  BIOMETRICS are an important and widely used class of methods for identity
verification and access control. Biometrics are attractive because they are
inherent properties of an individual. They need not be remembered like
passwords, and are not easily lost or forged like identifying documents. At the
same time, bio- metrics are fundamentally noisy and irreplaceable. There are
always slight variations among the measurements of a given biometric, and,
unlike passwords or identification numbers, biometrics are derived from
physical characteristics that cannot easily be changed. The proliferation of
biometric usage raises critical privacy and security concerns that, due to the
noisy nature of biometrics, cannot be addressed using standard cryptographic
methods. In this article we present an overview of "secure biometrics", also
referred to as "biometric template protection", an emerging class of methods
that address these concerns.


title:
PDF uncertainties in the determination of the W boson mass and of the
  effective lepton mixing angle at the LHC

abstract:
  The precision measurement of the W boson mass allows to perform stringent
consistency tests of the Standard Model by means of global electroweak fits.
The accurate determination of the W boson mass is one of the legacy results of
the Tevatron, where the experimental accuracy is such that $M_W$ is now limited
by theoretical uncertainties related to the parton distributions of the proton.
In this contribution, we show how to quantify the impact of PDF uncertainties
in the measurement of $M_W$ at the Tevatron and the LHC by means of a template
method, and study both the use of the W transverse mass and the lepton pT
kinematical distributions to generate these templates. We also present
preliminary results on the quantification of the PDF uncertainties in the
determination of the effective lepton mixing angle at the LHC, based on the
same template method as for the W mass determination


title:
On the high energy spin excitations in the high temperature
  superconductors: an RVB theory

abstract:
  The high energy spin excitation in the high T$_{c}$ cuprates is studied in
the single mode approximation for the $t-t'-J$ model. An exact form for the
mode dispersion is derived. When the Gutzwiller projected BCS state is used as
the variational ground state, a spin-wave-like dispersion of about 2.2$J$ is
uncovered along the $\Gamma=(0,0)$ to $\mathrm{M}=(\pi,0)$ line. Both the mode
energy and the integrated intensity of the spin fluctuation spectrum are found
to be almost doping independent in large doping range, which agrees very well
with the observations of recent RIXS measurements. Together with previous
studies on the quasiparticle properties of the Gutzwiiler projected BCS state,
our results indicate that such a Fermionic RVB theory can provide a consistent
description of both the itinerant and the local aspect of electronic
excitations in the high T$_{c}$ cuprates.


title:
Magnetic susceptibility and Landau diamagnetism of quantum collisional
  degenerate plasmas

abstract:
  With the use of correct expression of the electric conductivity of quantum
collisional degenerate plasmas (A. V. Latyshev and A. A. Yushkanov, Transverse
electrical conductivity of a quantum collisional plasma in the Mermin approach,
- Theor. and Math. Phys., {\bf 175}(1): 559-569 (2013)) the kinetic description
of a magnetic susceptibility is obtained and the formula for calculation of
Landau diamagnetism is deduced.


title: Semiparametric posterior limits

abstract:
  We review the Bayesian theory of semiparametric inference following Bickel
and Kleijn (2012) and Kleijn and Knapik (2013). After an overview of efficiency
in parametric and semiparametric estimation problems, we consider the
Bernstein-von Mises theorem (see, e.g., Le Cam and Yang (1990)) and generalize
it to (LAN) regular and (LAE) irregular semiparametric estimation problems. We
formulate a version of the semiparametric Bernstein-von Mises theorem that does
not depend on least-favourable submodels, thus bypassing the most restrictive
condition in the presentation of Bickel and Kleijn (2012). The results are
applied to the (regular) estimation of the linear coefficient in partial linear
regression (with a Gaussian nuisance prior) and of the kernel bandwidth in a
model of normal location mixtures (with a Dirichlet nuisance prior), as well as
the (irregular) estimation of the boundary of the support of a monotone family
of densities (with a Gaussian nuisance prior).


title:
Variable stars in the globular cluster NGC 7492. New discoveries and
  physical parameters determination

abstract:
  We have performed a photometric V, R, I CCD time-series analysis with a
baseline of ~8 years of the outer-halo globular cluster NGC 7492 with the aim
of searching for new variables and using these (and the previously known
variables) to determine the physical parameters of interest for the cluster
(e.g. metallicity, absolute magnitude of the horizontal branch, distance,
etc.).
  We use difference image analysis (DIA) to extract precise light curves in the
relatively crowded star field, especially towards the densely populated central
region. Several approaches are used for variability detection that recover the
known variables and lead to new discoveries. We determine the physical
parameters of the only RR0 star using light curve Fourier decomposition
analysis.
  We find one new long period variable and two SX Phe stars in the blue
straggler region. We also present one candidate SX Phe star which requires
follow-up observations. Assuming that the SX Phe stars are cluster members and
using the period-luminosity relation for these stars, we estimate their
distances as ~25.2+-1.8 and 26.8+-1.8 kpc, and identify their possible modes of
oscillation. We refine the periods of the two RR Lyrae stars in our field of
view. We find that the RR1 star V2 is undergoing a period change and possibly
exhibits the Blazhko effect. Fourier decomposition of the light curve of the
RR0 star V1 allows us to estimate the metallicity [Fe/H]_ZW-1.68+-0.10 or
[Fe/H]_UVES-1.64+-0.13, log-luminosity ~1.76+-0.02, absolute magnitude
~0.38+-0.04 mag, and true distance modulus of ~16.93+-0.04 mag, which is
equivalent to a distance of ~24.3+-0.5 kpc. All of these values are consistent
with previous estimates in the literature.


title: On the Quantization of Special K\"ahler Manifolds

abstract:
  We show how affine and projective special K\"ahler manifolds emerge from the
structure of quantization. We quantize them and construct natural
(wavefunction) representations for the corresponding coherent states. These in
turn are shown to satisfy the precise generalizations of the BCOV holomorphic
anomaly equation (hep-th/9309140), thus extending the work in hep-th/9306122.
As a byproduct of the analysis we construct the explicit general solution to
the holomorphic anomaly equation.


title: On a discrete symmetry of the Bremsstrahlung function in N=4 SYM

abstract:
  We consider the quark anti-quark potential on the three sphere in planar N=4
SYM and the associated vacuum potential in the near BPS limit with L units of
R-charge. The associated Bremsstrahlung function B_L has been recently computed
analytically by means of the Thermodynamical Bethe Ansatz. We discuss it at
strong coupling by computing it at large but finite L. We provide strong
support to a special symmetry of the Bremsstrahlung function under the formal
discrete Z_2 symmetry L -> -1-L. In this context, it is the counterpart of the
reciprocity invariance discovered in the past in the spectrum of various gauge
invariant composite operators. The Z_2 symmetry has remarkable consequences in
the scaling limit where L is taken to be large with fixed ratio to the 't Hooft
coupling. This limit organizes in inverse powers of the coupling and resembles
the semiclassical expansion of the dual string theory which is indeed known to
capture the leading classical term. We show that the various higher-order
contributions to the Bremsstrahlung function obey several constraints and, in
particular, the next-to-leading term, formally associated with the string
one-loop correction, is completely determined by the classical contribution.
The large L limit at strong coupling is also discussed.


title:
An upper bound of Singleton type for componentwise products of linear
  codes

abstract:
  We give an upper bound that relates the minimum weight of a nonzero
componentwise product of codewords from some given number of linear codes, with
the dimensions of these codes. Its shape is a direct generalization of the
classical Singleton bound.


title: Holographic thermalization in Gauss-Bonnet gravity

abstract:
  In the spirit of AdS/CFT correspondence, we study the thermalization of a
dual conformal field theory to Gauss-Bonnet gravity by modeling a thin-shell of
dust that interpolates between a pure AdS and a Gauss-Bonnet AdS black brane.
The renormalized geodesic length and minimal area surface, which in the dual
conformal field theory correspond to two-point correlation function and
expectation value of Wilson loop, are investigated respectively as
thermalization probes. The result shows that as the Gauss-Bonnet coefficient
increases, the thermalization time decreases for both the thermalization
probes, which can also be confirmed by studying the motion profile of the
geodesic and minimal area surface. In addition, for both the renormalized
geodesic length and minimal area surface, there is an overlapped region for a
fixed boundary separation, which implies that the Gauss-Bonnet coupling
constant has little effect on the thermalization probes there.


title: Autonomous Spacecraft Navigation With Pulsars

abstract:
  An external reference system suitable for deep space navigation can be
defined by fast spinning and strongly magnetized neutron stars, called pulsars.
Their beamed periodic signals have timing stabilities comparable to atomic
clocks and provide characteristic temporal signatures that can be used as
natural navigation beacons, quite similar to the use of GPS satellites for
navigation on Earth. By comparing pulse arrival times measured on-board a
spacecraft with predicted pulse arrivals at a reference location, the
spacecraft position can be determined autonomously and with high accuracy
everywhere in the solar system and beyond. The unique properties of pulsars
make clear already today that such a navigation system will have its
application in future astronautics. In this paper we describe the basic
principle of spacecraft navigation using pulsars and report on the current
development status of this novel technology.


title: Transport of spin-anisotropy without spin currents

abstract:
  We revisit the transport of spin-degrees of freedom across an electrically
and thermally biased tunnel junction between two ferromagnets with
non-collinear magnetizations. Besides the well-known charge and spin currents
we show that a non-zero spin-quadrupole current flows between the ferromagnets.
This tensor-valued current describes the non-equilibrium transport of
spin-anisotropy relating to both local and non-local multi-particle spin
correlations of the circuit. This quadratic spin-anisotropy, quantified in
terms of the spin-quadrupole moment, is fundamentally a two-electron quantity.
In spin-valves with an embedded quantum dot such currents have been shown to
result in a quadrupole accumulation that affects the measurable quantum dot
spin and charge dynamics. The spin-valve model studied here allows fundamental
questions about spin-quadrupole storage and transport to be worked out in
detail, while ignoring the detection by a quantum dot. This physical
understanding of this particular device is of importance for more complex
devices where spin-quadrupole transport can be detected. We demonstrate that,
as far as storage and transport are concerned, the spin anisotropy is only
partly determined by the spin polarization. In fact, for a thermally biased
spin-valve the charge- and spin-current may vanish, while a pure exchange
spin-quadrupole current remains, which appears as a fundamental consequence of
Pauli's principle. We extend the real-time diagrammatic approach to efficiently
calculate the average of multi-particle spin-observables, in particular the
spin-quadrupole current. Although the paper addresses only leading order and
spin-conserving tunneling we formulate the technique for arbitrary order in an
arbitrary, spin-dependent tunnel coupling in a way that lends itself to
extension to quantum-dot spin-valve structures.


title: From Josephson junction metamaterials to tunable pseudo-cavities

abstract:
  The scattering through a Josephson junction interrupting a superconducting
line is revisited including power leakage. We discuss also how to make tunable
and broadband resonant mirrors by concatenating junctions. As an application,
we show how to construct cavities using these mirrors, thus connecting two
research fields: JJ quantum metamaterials and coupled cavity arrays. We finish
by discussing the first non-linear corrections to the scattering and their
measurable effects.


title: One Component Dynamical Equation and Noise Induced Adiabaticity

abstract:
  The adiabatic theorem addresses the dynamics of a target instantaneous
eigenstate of a time-dependent Hamiltonian. We use a Feshbach P-Q partitioning
technique to derive a closed one-component integro-differential equation. The
resultant equation properly traces the footprint of the target eigenstate. The
physical significance of the derived dynamical equation is illustrated by both
general analysis and concrete examples. Surprisingly, we find an anomalous
phenomenon showing that a dephasing white noise can enhance and even induce
adiabaticity. This new phenomenon may naturally occur in many physical systems.
We also show that white noises can also shorten the total duration of dynamic
processes such as adiabatic quantum computing.


title: Minimal see-saw model predicting best fit lepton mixing angles

abstract:
  We discuss a minimal predictive see-saw model in which the right-handed
neutrino mainly responsible for the atmospheric neutrino mass has couplings to
(nu_e, nu_mu, nu_tau) proportional to (0,1,1) and the right-handed neutrino
mainly responsible for the solar neutrino mass has couplings to (nu_e, nu_mu,
nu_tau) proportional to (1,4,2), with a relative phase eta = -2pi/5. We show
how these patterns of couplings could arise from an A_4 family symmetry model
of leptons, together with Z_3 and Z_5 symmetries which fix eta = -2pi/5 up to a
discrete phase choice. The PMNS matrix is then completely determined by one
remaining parameter which is used to fix the neutrino mass ratio m_2/m_3. The
model predicts the lepton mixing angles theta12=34 degrees, theta23=41 degrees,
theta13=9.5 degrees, which exactly coincide with the current best fit values
for a normal neutrino mass hierarchy, together with the distinctive prediction
for the CP violating oscillation phase delta =106 degrees.


title: A multi-domain approach to asteroid families identification

abstract:
  Previous works have identified families halos by an analysis in proper
elements domains, or by using Sloan Digital Sky Survey-Moving Object Catalog
data, fourth release (SDSS-MOC4) multi-band photometry to infer the asteroid
taxonomy, or by a combination of the two methods. The limited number of
asteroids for which geometric albedo was known until recently discouraged in
the past the extensive use of this additional parameter, which is however of
great importance in identifying an asteroid taxonomy. The new availability of
geometric albedo data from the Wide-field Infrared Survey Explorer (WISE)
mission for about 100,000 asteroids significantly increased the sample of
objects for which such information, with some errors, is now known.
  In this work we proposed a new method to identify families halos in a
multi-domain space composed by proper elements, SDSS-MOC4 (a*,i-z) colors, and
WISE geometric albedo for the whole main belt (and the Hungaria and Cybele
orbital regions). Assuming that most families were created by the breakup of an
undifferentiated parent body, they are expected to be homogeneous in colors and
albedo. The new method is quite effective in determining objects belonging to a
family halo, with low percentages of likely interlopers, and results that are
quite consistent in term of taxonomy and geometric albedo of the halo members.


title: A Note on Supersymmetric Chiral Bosons

abstract:
  In this note we extend the Pasti-Sorokin-Tonin formalism for chiral bosons in
two dimensions to $N=(1,1)$ and $N=(2,2)$ superspace. In the latter case the
formalism is developed for chiral, twisted chiral and semi-chiral superfields.


title:
Optimal maps and exponentiation on finite dimensional spaces with Ricci
  curvature bounded from below

abstract:
  We prove existence and uniqueness of optimal maps on $RCD^*(K,N)$ spaces
under the assumption that the starting measure is absolutely continuous. We
also discuss how this result naturally leads to the notion of exponentiation.


title: Distribution of resonances for hyperbolic surfaces

abstract:
  We study the distribution of resonances for geometrically finite hyperbolic
surfaces of infinite area by countting resonances numerically. The resonances
are computed as zeros of the Selberg zeta function, using an algorithm for
computation of the zeta function for Schottky groups. Our particular focus is
on three aspects of the resonance distribution that have attracted attention
recently: the fractal Weyl law, the spectral gap, and the concentration of
decay rates.


title:
Gravitational-thermodynamic instabilities of isothermal spheres in dS
  and AdS

abstract:
  Thermodynamical stability of fluid spheres is studied in the presence of a
cosmological constant, both in the Newtonian limit, as well as in General
Relativity. In all cases, an increase of the cosmological constant tends to
stabilize the system, making asymptotically de Sitter space more
thermodynamically stable than anti-de Sitter at the purely classical level. In
addition, in the Newtonian case reentrant phase transitions are observed for a
positive cosmological constant, due to its repelling property in this case. In
General Relativity is studied the case of radiation, for which is found that
the critical radius, at which an instability sets in, is always bigger than the
black hole radius of the system and furthermore, at some value of the
cosmological constant this critical radius hits at the cosmological horizon.


title:
Graphene Metallization of High-Stress Silicon Nitride Resonators for
  Electrical Integration

abstract:
  High stress stoichiometric silicon nitride resonators, whose quality factors
exceed one million, have shown promise for applications in sensing and signal
processing. Yet, electrical integration of the insulating silicon nitride
resonators has been challenging, as depositing even a thin layer of metal
degrades the quality factor significantly. In this work, we show that graphene
used as a conductive coating for Si3N4 membranes reduces the quality factor by
less than 30 % on average, which is minimal when compared to the effect of
conventional metallization layers such as chromium or aluminum. The electrical
integration of Si3N4-Graphene (SiNG) heterostructure resonators is demonstrated
with electrical readout and electro-static tuning of the frequency by up to 1 %
per volt. These studies demonstrate the feasibility of hybrid graphene/nitride
mechanical resonators in which the electrical properties of graphene are
combined with the superior mechanical performance of silicon nitride.


title: N = (2, 2) Non-Linear sigma-Models: A Synopsis

abstract:
  We review N=(2,2) supersymmetric non-linear sigma-models in two dimensions
and their relation to generalized Kahler and Calabi-Yau geometry. We illustrate
this with an explicit non-trivial example.


title: An overview on the proof of the splitting theorem in non-smooth context

abstract:
  We give a quite detailed overview on the proof of the Cheeger-Colding-Gromoll
splitting theorem in the abstract framework of spaces with Riemannian Ricci
curvature bounded from below.


title: GPU Enhancement of the Trigger to Extend Physics Reach at the LHC

abstract:
  Significant new challenges are continuously confronting the High Energy
Physics (HEP) experiments, in particular the two detectors at the Large Hadron
Collider (LHC) at CERN, where nominal conditions deliver proton-proton
collisions to the detectors at a rate of 40 MHz. This rate must be
significantly reduced to comply with both the performance limitations of the
mass storage hardware and the capabilities of the computing resources to
process the collected data in a timely fashion for physics analysis. At the
same time, the physics signals of interest must be retained with high
efficiency.
  The quest for rare new physics phenomena at the LHC leads us to evaluate a
Graphics Processing Unit (GPU) enhancement of the existing High-Level Trigger
(HLT), made possible by the current flexibility of the trigger system, which
not only provides faster and more efficient event selection, but also includes
the possibility of new complex triggers that were not previously feasible. A
new tracking algorithm is evaluated on a NVIDIA Tesla K20c GPU, allowing for
the first time the reconstruction of long-lived particles at the tracker system
in the trigger. Preliminary time performance and efficiency will be presented.


title:
Self-potentials in partially saturated media: the importance of explicit
  modeling of electrode effects

abstract:
  Self-potential (SP) data are of interest to vadose zone hydrology because of
their direct sensitivity to water flow and ionic transport. There is
unfortunately little consensus in the literature about how to best model SP
data under partially saturated conditions and different approaches (often
supported by one laboratory data set alone) have been proposed. We argue herein
that this lack of agreement can largely be traced to electrode effects that
have not been properly taken into account. A series of drainage and imbibition
experiments are considered, in which we find that previously proposed
approaches to remove electrode effects are unlikely to provide adequate
corrections. Instead, we explicitly model the electrode effects together with
classical SP contributions using a flow and transport model. The simulated data
agree overall with the observed SP signals and allow decomposing the different
signal contributions to analyze them separately. By reviewing other published
experimental data, we suggest that most of them include electrode effects that
have not been properly taken into account. Our results suggest that previously
presented SP theory works well when considering the modeling uncertainties
presently associated with electrode effects. Additional work is warranted to
not only develop suitable electrodes for laboratory experiments, but also to
assure that associated electrode effects that appear inevitable in longer-term
experiments are predictable, such that they can be incorporated in the modeling
framework.


title: Two old ways to measure the electron-neutrino mass

abstract:
  Three decades ago, the measurement of the electron neutrino mass in atomic
electron capture (EC) experiments was scrutinized in its two variants: single
EC and neutrino-less double EC. For certain isotopes an atomic resonance
enormously enhances the expected decay rates. The favoured technique, based on
calorimeters as opposed to spectrometers, has the advantage of greatly
simplifying the theoretical analysis of the data. After an initial surge of
measurements, the EC approach did not seem to be competitive. But very
recently, there has been great progress on micro-calorimeters and the
measurement of atomic mass differences. Meanwhile, the beta-decay neutrino-mass
limits have improved by a factor of 15, and the difficulty of the experiments
by the cube of that figure. Can the "calorimetric" EC theory cope with this
increased challenge? I answer this question affirmatively. In so doing I
briefly review the subject and extensively address some persistent
misunderstandings of the underlying quantum physics.


title:
Thresholding of Semantic Similarity Networks using a Spectral Graph
  Based Technique

abstract:
  Semantic similarity measures (SSMs) refer to a set of algorithms used to
quantify the similarity of two or more terms belonging to the same ontology.
Ontology terms may be associated to concepts, for instance in computational
biology gene and proteins are associated with terms of biological ontologies.
Thus, SSMs may be used to quantify the similarity of genes and proteins
starting from the comparison of the associated annotations. SSMs have been
recently used to compare genes and proteins even on a system level scale. More
recently some works have focused on the building and analysis of Semantic
Similarity Networks (SSNs) i.e. weighted networks in which nodes represents
genes or proteins while weighted edges represent the semantic similarity score
among them. SSNs are quasi-complete networks, thus their analysis presents
different challenges that should be addressed. For instance, the need for the
introduction of reliable thresholds for the elimination of meaningless edges
arises. Nevertheless, the use of global thresholding methods may produce the
elimination of meaningful nodes, while the use of local thresholds may
introduce biases. For these aims, we introduce a novel technique, based on
spectral graph considerations and on a mixed global-local focus. The
effectiveness of our technique is demonstrated by using markov clustering for
the extraction of biological modules. We applied clustering to simplified
networks demonstrating a considerable improvements with respect to the original
ones.


title: Extract ABox Modules for Efficient Ontology Querying

abstract:
  The extraction of logically-independent fragments out of an ontology ABox can
be useful for solving the tractability problem of querying ontologies with
large ABoxes. In this paper, we propose a formal definition of an ABox module,
such that it guarantees complete preservation of facts about a given set of
individuals, and thus can be reasoned independently w.r.t. the ontology TBox.
With ABox modules of this type, isolated or distributed (parallel) ABox
reasoning becomes feasible, and more efficient data retrieval from ontology
ABoxes can be attained. To compute such an ABox module, we present a
theoretical approach and also an approximation for $\mathcal{SHIQ}$ ontologies.
Evaluation of the module approximation on different types of ontologies shows
that, on average, extracted ABox modules are significantly smaller than the
entire ABox, and the time for ontology reasoning based on ABox modules can be
improved significantly.


title: The stellar content of the young open cluster Trumpler 37

abstract:
  With an apparent cluster diameter of 1.5{\deg} and an age of ~4 Myr, Trumpler
37 is an ideal target for photometric monitoring of young stars as well as for
the search of planetary transits, eclipsing binaries and other sources of
variability. The YETI consortium has monitored Trumpler 37 throughout 2010 and
2011 to obtain a comprehensive view of variable phenomena in this region. In
this first paper we present the cluster properties and membership determination
as derived from an extensive investigation of the literature. We also compared
the coordinate list to some YETI images. For 1872 stars we found literature
data. Among them 774 have high probability of being member and 125 a medium
probability. Based on infrared data we re-calculate a cluster extinction of
0.9-1.2 mag. We can confirm the age and distance to be 3-5 Myr and ~870 pc.
Stellar masses are determined from theoretical models and the mass function is
fitted with a power-law index of alpha=1.90 (0.1-0.4 M_sun) and alpha=1.12
(1-10 M_sun).


title:
First-order perturbative calculation of the frequency-shifts caused by
  static cylindrically-symmetric electric and magnetic imperfections of a
  Penning trap

abstract:
  The ideal Penning trap consists of a uniform magnetic field and an
electrostatic quadrupole potential. Cylindrically-symmetric deviations thereof
are parametrized by the coefficients Bn and Cn, respectively. Relativistic
mass-increase aside, the three characteristic eigenfrequencies of a charged
particle stored in an ideal Penning trap are independent of the three motional
amplitudes. This three-fold harmonicity is a highly-coveted virtue for
precision experiments that rely on the measurement of at least one
eigenfrequency in order to determine fundamental properties of the stored
particle, such as its mass. However, higher-order contributions to the ideal
fields result in amplitude-dependent frequency-shifts. In turn, these
frequency-shifts need to be understood for estimating systematic experimental
errors, and eventually for correcting them by means of calibrating the
imperfections. The problem of calculating the frequency-shifts caused by small
imperfections of a near-ideal trap yields nicely to perturbation theory,
producing analytic formulas that are easy to evaluate for the relevant
parameters of an experiment. In particular, the frequency-shifts can be
understood on physical rather than purely mathematical grounds by considering
which terms actually drive them. Based on identifying these terms, we derive
general formulas for the first-order frequency-shifts caused by any
perturbation parameter Bn or Cn.


title:
Increase of cationic concentration due to bending of overcharged DNA in
  strong Coulomb coupling regime

abstract:
  This study reveals that, in strong coulomb coupling regime, bending a
straight and fully overcharged DNA (up to its maximal acceptance by multivalent
counterions) to a circle releases some of the adsorbed (correlated)counterions
but still remains fully overcharged. This phenomenon seems to be inherent to
the minimum energy state of a DNA. By definition, the total electrostatic
potential energy of a macroion-counterion system reaches to its lowest point at
maximal acceptance of overcharging counterions that ensures the most stable
conformation. This intermediate phenomenon of release of cations from DNA
surface due to bending can be taken into account in theoretical modeling of
some ionic concentration dependent physico-chemical aspects of DNA solutions in
strong Coulomb coupling regimes.


title:
Symbiotic stars and other Halpha emission line stars towards the
  Galactic Bulge

abstract:
  Symbiotic stars are interacting binaries with the longest orbital periods and
their multi-component structure makes them rich astrophysical laboratories. The
accretion of a high mass loss rate red giant wind on to a white dwarf (WD)
makes them promising Type Ia supernovae (SNe Ia) progenitors. Systematic
surveys for new Galactic symbiotic stars are critical to identify new promising
SNe Ia progenitors (e.g. RS Oph) and to better estimate the total population
size to compare against SNe Ia rates. Central to the latter objective is
building a complete census of symbiotic stars towards the Galactic Bulge. Here
we report on the results of a systematic survey of Halpha emission line stars
covering 35 deg^2. It is distinguished by the combination of deep optical
spectroscopy and long-term lightcurves that improve the certainty of our
classifications. A total of 20 bona-fide symbiotic stars are found (13 S-types,
6 D-types and 1 D'-type), 35% of which show the symbiotic specific
Raman-scattered OVI emission bands, as well as 15 possible symbiotic stars that
require further study (6 S-types and 9 D-types). Lightcurves show a diverse
range of variability including stellar pulsations (semi-regular and Mira),
orbital variations and slow changes due to dust. Orbital periods are determined
for 5 S-types and pulsation periods for 3 D-types. The most significant D-type
found is H1-45 and its carbon Mira with a pulsation period of 408.6 days,
corresponding to a distance of ~6.2+-1.4 kpc and M_K=-8.06+-0.12 mag. If H1-45
belongs to the Galactic Bulge, then it would be the first bona-fide luminous
Galactic Bulge carbon star. The lack of luminous carbon stars in the Bulge is a
longstanding unsolved problem. A possible explanation for H1-45 may be that the
carbon enhancement was accreted from the progenitor of the WD companion. A wide
variety of unusual emission line stars were also identified. (abridged)


title: Atomic scale friction of molecular adsorbates during diffusion

abstract:
  Experimental observations suggest that molecular adsorbates exhibit a larger
friction coefficient than atomic species of comparable mass, yet the origin of
this increased friction is not well understood. We present a study of the
microscopic origins of friction experienced by molecular adsorbates during
surface diffusion. Helium spin-echo measurements of a range of five-membered
aromatic molecules, cyclopentadienyl (Cp), pyrrole and thiophene, on a
copper(111) surface are compared with molecular dynamics simulations of the
respective systems. The adsorbates have different chemical interactions with
the surface and differ in bonding geometry, yet the measurements show that the
friction is greater than 2 ps$^{-1}$ for all these molecules. We demonstrate
that the internal and external degrees of freedom of these adsorbate species
are a key factor in the underlying microscopic processes and identify the
rotation modes as the ones contributing most to the total measured friction
coefficient.


title:
VLBI astrometry of PSR J2222-0137: a pulsar distance measured to 0.4%
  accuracy

abstract:
  The binary pulsar J2222-0137 is an enigmatic system containing a partially
recycled millisecond pulsar and a companion of unknown nature. Whilst the low
eccentricity of the system favors a white dwarf companion, an unusual double
neutron star system is also a possibility, and optical observations will be
able to distinguish between these possibilities. In order to allow the absolute
luminosity (or upper limit) of the companion object to be properly calibrated,
we undertook astrometric observations with the Very Long Baseline Array to
constrain the system distance via a measurement of annual geometric parallax.
With these observations, we measure the parallax of the J2222-0137 system to be
3.742 +0.013 -0.016 milliarcseconds, yielding a distance of 267.3 +1.2 -0.9 pc,
and measure the transverse velocity to be 57.1 +0.3 -0.2 km/s. Fixing these
parameters in the pulsar timing model made it possible to obtain a measurement
of Shapiro delay and hence the system inclination, which shows that the system
is nearly edge-on (sin i = 0.9985 +/- 0.0005). Furthermore, we were able to
detect the orbital motion of J2222-0137 in our VLBI observations and measure
the longitude of ascending node. The VLBI astrometry yields the most accurate
distance obtained for a radio pulsar to date, and is furthermore the most
accurate parallax for any radio source obtained at "low" radio frequencies
(below ~5 GHz, where the ionosphere dominates the error budget). Using the
astrometric results, we show the companion to J2222-0137 will be easily
detectable in deep optical observations if it is a white dwarf. Finally, we
discuss the implications of this measurement for future ultra-high-precision
astrometry, in particular in support of pulsar timing arrays.


title:
Collapse of a cylindrically symmetric, self-similar scalar field with
  non-minimal coupling: Solutions with a regular axis

abstract:
  We investigate self-similar scalar field solutions to the Einstein equations
in whole cylinder symmetry. Imposing self-similarity on the spacetime gives
rise to a set of single variable functions describing the metric. Furthermore,
it is shown that the scalar field is dependent on a single unknown function of
the same variable and that the scalar field potential has exponential form. The
Einstein equations then take the form of a set of ODEs. Self-similarity also
gives rise to a singularity at the scaling origin. We discuss the number of
degrees of freedom at an arbitrary point and prove existence and uniqueness of
a 2-parameter family of solutions with a regular axis. We discuss the evolution
of these solutions away from the axis toward the past null cone of the
singularity, determining the maximal interval of existence in each case.


title: Suzaku observations of the low surface brightness cluster A76

abstract:
  Context: We present results of Suzaku observations of a nearby galaxy cluster
A76 at z=0.0395. This cluster is characterized by extremely low X-ray surface
brightness and is hereafter referred to as the LSB cluster. Aims: To understand
the nature and thermodynamic evolution of the LSB cluster by studying the
physical properties of the hot intracluster medium in A76. Methods: We
conducted two-pointed Suzaku observations of A76 and examined the global gas
properties of the cluster by XIS spectral analysis. We also performed
deprojection analysis of annular spectra and derived radial profiles of gas
temperature, density and entropy out to approximately 850 kpc (~ 0.6 r_200) and
560 kpc (~0.4 r_200) in A76 East and A76 West, respectively. Results: The
measured global temperature and metal abundance are approximately 3.3 keV and
0.24 solar, respectively. From the deprojection analysis, the entropy profile
is found to be flat with respect to radius. The entropy within the central
region (r < 0.2r_200) is exceptionally high (~400 keV cm^2). This phenomenon is
not readily explained by either gravitational heating or preheating. The X-ray
morphology is clumped and irregular, and the electron density is extremely low
(1e-4 -- 1e-3 cm^-3) for the observed high temperature, suggesting that A76 is
in the early phase of cluster formation and the gas compression due to
gravitational potential confinement is lagging behind the gas heating.


title: Asynchronous BFT Storage with 2t+1 Data Replicas

abstract:
  The cost of Byzantine Fault Tolerant (BFT) storage is the main concern
preventing its adoption in practice. This cost stems from the need to maintain
at least 3t+1 replicas in different storage servers in the asynchronous model,
so that t Byzantine replica faults can be tolerated. In this paper, we present
MDStore, the first fully asynchronous read/write BFT storage protocol that
reduces the number of data replicas to as few as 2t+1, maintaining 3t+1
replicas of metadata at (possibly) different servers. At the heart of MDStore
store is its metadata service that is built upon a new abstraction we call
timestamped storage. Timestamped storage both allows for conditional writes
(facilitating the implementation of a metadata service) and has consensus
number one (making it implementable wait-free in an asynchronous system despite
faults). In addition to its low data replication factor, MDStore offers very
strong guarantees implementing multi-writer multi-reader atomic wait-free
semantics and tolerating any number of Byzantine readers and crash-faulty
writers. We further show that MDStore data replication overhead is optimal;
namely, we prove a lower bound of 2t+1 on the number of data replicas that
applies even to crash-tolerant storage with a fault-free metadata service
oracle. Finally, we prove that separating data from metadata for reducing the
cost of BFT storage is not possible without cryptographic assumptions. However,
our MDStore protocol uses only lightweight cryptographic hash functions.


title:
The Infinitesimal-Operator Algebras of Continuous Groups with Antilinear
  Operations

abstract:
  Continuous groups with antilinear operations of the form $G+a_0G$, where $G$
denotes a linear Lie group, and $a_0$ is an antilinear operation which fulfills
the condition $a^2_0=\pm 1$, were defined and their matrix algebras were
investigated in \cite{Kocinski4}. In this paper infinitesimal-operator algebras
are defined for any group of the form $G+a_0G$, and their properties are
determined.


title:
Six-Dimensional Superconformal Field Theories from Principal 3-Bundles
  over Twistor Space

abstract:
  We construct manifestly superconformal field theories in six dimensions which
contain a non-Abelian tensor multiplet. In particular, we show how principal
3-bundles over a suitable twistor space encode solutions to these self-dual
tensor field theories via a Penrose-Ward transform. The resulting higher or
categorified gauge theories significantly generalise those obtained previously
from principal 2-bundles in that the so-called Peiffer identity is relaxed in a
systematic fashion. This transform also exposes various unexplored structures
of higher gauge theories modelled on principal 3-bundles such as the relevant
gauge transformations. This enables us to formulate the non-Abelian
differential cohomology that describes principal 3-bundles with connective
structures.


title:
Hypernuclear spectroscopy of products from 6Li projectiles on a carbon
  target at 2 AGeV

abstract:
  A novel experiment, aiming at demonstrating the feasibility of hypernuclear
spectroscopy with heavy-ion beams, was conducted. Using the invariant mass
method, the spectroscopy of hypernuclear products of 6Li projectiles on a
carbon target at 2 AGeV was performed. Signals of the \Lambda-hyperon and
3\Lambda H and 4\Lambda H hypernuclei were observed for final states of
p+\pi^-, 3He+\pi^- and 4He+\pi^-, respectively, with significance values of
6.7, 4.7 and 4.9\sigma. By analyzing the proper decay time from secondary
vertex distribution with the unbinned maximum likelihood fitting method, their
lifetime values were deduced to be $262 ^{+56}_{-43} \pm 45$ ps for \Lambda,
$183 ^{+42}_{-32} \pm 37$ ps for 3\Lambda H, and $140 ^{+48}_{-33}\pm 35 $ ps
for 4\Lambda H.


title: Property of rapid decay for extensions of compactly generated groups

abstract:
  In the article we settle down the problem of permanence of property RD under
group extensions. We show that if $1\to N\to G\to Q\to 1$ is a short exact
sequence of compactly generated groups such that $Q$ has property RD, and $N$
has property RD with respect to the restriction of a word-length on $G$, then
$G$ has property RD.
  We also generalize the result of Ji and Schweitzer stating that locally
compact groups with property RD are unimodular. Namely, we show that any
automorphism of a locally compact group with property RD which distorts
distances subexponentially, preserves the Haar measure.


title:
Spin-orbit torques in Co/Pt(111) and Mn/W(001) magnetic bilayers from
  first principles

abstract:
  An applied electric current through a space-inversion asymmetric magnet
induces spin-orbit torques (SOTs) on the magnetic moments, which holds much
promise for future memory devices. We discuss general Green's function
expressions suitable to compute the linear-response SOT in disordered
ferromagnets. The SOT can be decomposed into an even and an odd component with
respect to magnetization reversal, where in the limit of vanishing disorder the
even SOT is given by the constant Berry curvature of the occupied states, while
the odd part exhibits a divergence with respect to disorder strength. Within
this formalism, we perform first principles density-functional theory
calculations of the SOT in Co/Pt(111) and Mn/W(001) magnetic bilayers. We find
the even and odd torque components to be of comparable magnitude. Moreover, the
odd torque depends strongly on an additional capping layer, while the even
torque is less sensitive. We show that the even torque is nearly entirely
mediated by spin currents in contrast to the odd torque, which can contain an
important contribution not due to spin transfer. Our results are in agreement
with experiments, showing that our linear response theory is well-suited for
the description of SOTs in complex ferromagnets.


title: The Query Complexity of Correlated Equilibria

abstract:
  We consider the complexity of finding a correlated equilibrium of an
$n$-player game in a model that allows the algorithm to make queries on
players' payoffs at pure strategy profiles. Randomized regret-based dynamics
are known to yield an approximate correlated equilibrium efficiently, namely,
in time that is polynomial in the number of players $n$. Here we show that both
randomization and approximation are necessary: no efficient deterministic
algorithm can reach even an approximate correlated equilibrium, and no
efficient randomized algorithm can reach an exact correlated equilibrium. The
results are obtained by bounding from below the number of payoff queries that
are needed.


title:
Combinatorial theory of the semiclassical evaluation of transport
  moments I: Equivalence with the random matrix approach

abstract:
  To study electronic transport through chaotic quantum dots, there are two
main theoretical approachs. One involves substituting the quantum system with a
random scattering matrix and performing appropriate ensemble averaging. The
other treats the transport in the semiclassical approximation and studies
correlations among sets of classical trajectories. There are established
evaluation procedures within the semiclassical evaluation that, for several
linear and non-linear transport moments to which they were applied, have always
resulted in the agreement with random matrix predictions. We prove that this
agreement is universal: any semiclassical evaluation within the accepted
procedures is equivalent to the evaluation within random matrix theory.
  The equivalence is shown by developing a combinatorial interpretation of the
trajectory sets as ribbon graphs (maps) with certain properties and exhibiting
systematic cancellations among their contributions. Remaining trajectory sets
can be identified with primitive (palindromic) factorisations whose number
gives the coefficients in the corresponding expansion of the moments of random
matrices. The equivalence is proved for systems with and without time reversal
symmetry.