title: A Mean Field Game Approach to Scheduling in Cellular Systems

abstract:
  We study auction-theoretic scheduling in cellular networks using the idea of
mean field equilibrium (MFE). Here, agents model their opponents through a
distribution over their action spaces and play the best response. The system is
at an MFE if this action is itself a sample drawn from the assumed
distribution. In our setting, the agents are smart phone apps that generate
service requests, experience waiting costs, and bid for service from base
stations. We show that if we conduct a second-price auction at each base
station, there exists an MFE that would schedule the app with the longest queue
at each time. The result suggests that auctions can attain the same desirable
results as queue-length-based scheduling. We present results on the asymptotic
convergence of a system with a finite number of agents to the mean field case,
and conclude with simulation results illustrating the simplicity of computation
of the MFE.


title:
Efficient detection of a highly bright photon source using
  superconducting nanowire single photon detectors

abstract:
  We investigate the detection of an ultra-bright single-photon source using
highly efficient superconducting nanowire single-photon detectors (SNSPDs) at
telecom wavelengths. Both the single-photon source and the detectors are
characterized in detail. At a pump power of 100 mW (400 mW), the measured
coincidence counts can achieve 400 kcps (1.17 Mcps), which is the highest ever
reported at telecom wavelengths to the best of our knowledge. The multi-pair
contributions at different pump powers are analyzed in detail. We compare the
experimental and theoretical second order coherence functions $g^{(2)}(0)$ and
find that the conventional experimentally measured $g^{(2)}(0)$ values are
smaller than the theoretically expected ones. We also consider the saturation
property of SNSPD and find that SNSPD can be easier to saturate with a thermal
state rather than with a coherent state. The experimental data and theoretical
analysis should be useful for the future experiments to detect ultra-bright
down-conversion sources with high-efficiency detectors.


title: Domain walls in the coupled Gross-Pitaevskii equations

abstract:
  A thorough study of domain wall solutions in coupled Gross-Pitaevskii
equations on the real line is carried out including existence of these
solutions; their spectral and nonlinear stability; their persistence and
stability under a small localized potential. The proof of existence is
variational and is presented in a general framework: we show that the domain
wall solutions are energy minimizing within a class of vector-valued functions
with nontrivial conditions at infinity. The admissible energy functionals
include those corresponding to coupled Gross--Pitaevskii equations, arising in
modeling of Bose-Einstein condensates. The results on spectral and nonlinear
stability follow from properties of the linearized operator about the domain
wall. The methods apply to many systems of interest and integrability is not
germane to our analysis. Finally, sufficient conditions for persistence and
stability of domain wall solutions are obtained to show that stable pinning
occurs near maxima of the potential, thus giving rigorous justification to
earlier results in the physics literature.


title:
The initial mass function of star clusters that form in turbulent
  molecular clouds

abstract:
  We simulate the formation and evolution of young star clusters using the
combination of SPH simulations and direct N-body simulations. We start by
performing SPH simulations of the giant molecular cloud with a turbulent
velocity field, a mass of $4\times10^4$ to $5\times10^6M_{\odot}$, and a
density between $1.7\times10^3$ and $170cm^{-3}$. We continue the SPH
simulations for a free-fall time scale, and analyze the resulting structure of
the collapsed cloud. We subsequently replace a density-selected subset of SPH
particles with stars by adopting a local star-formation efficiency proportional
to $\rho^{1/2}$. As a consequence, the local star formation efficiency exceeds
30 %, whereas globally only a few % of the gas is converted to stars. The
stellar distribution by the time gas is converted to stars is very clumpy, with
typically a dozen bound conglomerates that consist of 100 to $10^4$ stars. We
continue to evolve the stars dynamically using the collisional N-body method,
which accurately treats all pairwise interactions, stellar collisions and
stellar evolution. We analyze the results of the N-body simulations when the
stars have an age of 2 Myr and 10 Myr. During the dynamical simulations,
massive clusters grow via hierarchical merging of smaller clusters. The shape
of the cluster mass function that originates from an individual molecular cloud
is consistent with a Schechter function with a power-law slope of -1.73 at 2
Myr and -1.67 at 10 Myr, which fits to observed cluster mass function of the
Carina region. The superposition of mass functions have a power-law slope of <
-2, which fits the observed mass function of star clusters in the Milky Way,
M31 and M83. We further find that the mass of the most massive cluster formed
in a single molecular cloud with a mass of $M_g$ scales with $6.1M_g^{0.51}$
which also agrees with recent observation of the GMC and young clusters in M51.


title: A study of Be stars in the Magellanic Clouds

abstract:
  We present the results of a photometric survey for Be stars in eleven young
clusters in the Large Magellanic Cloud and fourteen young clusters in the Small
Magellanic Cloud. B stars with hydrogen in emission are identified on the basis
of their R-H{\alpha} colour. We find that Be star fraction in clusters
decreases with cluster age, and also decreases with the metallicity.


title:
Random data Cauchy theory for nonlinear wave equations of power-type on
  $\mathbb{R}^3$

abstract:
  We consider the defocusing nonlinear wave equation of power-type on
$\mathbb{R}^3$. We establish an almost sure global existence result with
respect to a suitable randomization of the initial data. In particular, this
provides examples of initial data of super-critical regularity which lead to
global solutions. The proof is based upon Bourgain's high-low frequency
decomposition and improved averaging effects for the free evolution of the
randomized initial data.


title: Graded Causation and Defaults

abstract:
  Recent work in psychology and experimental philosophy has shown that
judgments of actual causation are often influenced by consideration of
defaults, typicality, and normality. A number of philosophers and computer
scientists have also suggested that an appeal to such factors can help deal
with problems facing existing accounts of actual causation. This paper develops
a flexible formal framework for incorporating defaults, typicality, and
normality into an account of actual causation. The resulting account takes
actual causation to be both graded and comparative. We then show how our
account would handle a number of standard cases.


title: Compact Representations of Extended Causal Models

abstract:
  Judea Pearl was the first to propose a definition of actual causation using
causal models. A number of authors have suggested that an adequate account of
actual causation must appeal not only to causal structure, but also to
considerations of normality. In earlier work, we provided a definition of
actual causation using extended causal models, which include information about
both causal structure and normality. Extended causal models are potentially
very complex. In this paper, we show how it is possible to achieve a compact
representation of extended causal models.


title:
Weighted regret-based likelihood: a new approach to describing
  uncertainty

abstract:
  Recently, Halpern and Leung suggested representing uncertainty by a weighted
set of probability measures, and suggested a way of making decisions based on
this representation of uncertainty: maximizing weighted regret. Their paper
does not answer an apparently simpler question: what it means, according to
this representation of uncertainty, for an event E to be more likely than an
event E'. In this paper, a notion of comparative likelihood when uncertainty is
represented by a weighted set of probability measures is defined. It
generalizes the ordering defined by probability (and by lower probability) in a
natural way; a generalization of upper probability can also be defined. A
complete axiomatic characterization of this notion of regret-based likelihood
is given.


title:
Electron spin and the origin of Bio-homochirality I. Extant enzymatic
  reaction model

abstract:
  In this paper, I tentatively put forward a new hypothesis that the emergence
of a single chiral form of biomolecules in living organisms is specifically
determined by the electron spin state during their enzyme-catalyzed synthesis
processes. Specifically speaking, the electrons released from the coenzyme
NAD(P)H of amino acid synthase are heterogeneous in spin states; however, when
they pass through the chiral alpha-helix structure of the enzymes to the site
of amino acid synthesis at the other end of the helix, their spin states are
filtered and polarized, producing only spin up electrons; once the
spin-polarized electrons participate in the reductive reaction between
alpha-oxo acid and ammonia, only L-amino acids are formed according to the
Pauli exclusion principle.


title: A GPU Implementation for Two-Dimensional Shallow Water Modeling

abstract:
  In this paper, we present a GPU implementation of a two-dimensional shallow
water model. Water simulations are useful for modeling floods, river/reservoir
behavior, and dam break scenarios. Our GPU implementation shows vast
performance improvements over the original Fortran implementation. By taking
advantage of the GPU, researchers and engineers will be able to study water
systems more efficiently and in greater detail.


title: Next to new minimal standard model

abstract:
  We suggest a minimal extension of the standard model, which can explain
current experimental data of the dark matter, small neutrino masses and baryon
asymmetry of the universe, inflation, and dark energy, and achieve gauge
coupling unification. The gauge coupling unification can explain the charge
quantization, and be realized by introducing six new fields. We investigate the
vacuum stability, coupling perturbativity, and correct dark matter abundance in
this model by use of current experimental data.


title: Bug Tracking and Reporting System

abstract:
  This is the world of information. The ever growing field Information
Technology has its many advanced notable features which made it what it was now
today. In this world, the information has to be processed, clearly distributed
and must be efficiently reachable to the end users intended for that. Otherwise
we know it lead to disastrous situations. The other coin of the same phase is
it is absolutely necessary to know any bugs that are hither to faced by the end
users. The project Bug Tracking and Reporting System aims to provide the
solution for that. The Bug Tracker can be made from any two types. The first
one being the system side, the other being the services side. Our project deals
with the second one. The paper is wholly dedicated to tracking the bugs that
are hither by arise. The administrator maintains the master details regarding
to the bugs id, bugs type, bugs description, bugs severity, bugs status, user
details. The administrator too has the authority to update the master details
of severity level, status level, etc, modules of the paper. The administrator
adds the users and assign them responsibility of completing the paper. Finally
on analyzing the paper assigned to the particular user, the administrator can
track the bugs, and it is automatically added to the tables containing the
bugs, by order of severity and status. The administrator can know the
information in tact the various paper s assigned to various users, their bug
tracking status, their description etc in the form of reports from time to
time.


title: Noisy Sparse Subspace Clustering

abstract:
  This paper considers the problem of subspace clustering under noise.
Specifically, we study the behavior of Sparse Subspace Clustering (SSC) when
either adversarial or random noise is added to the unlabelled input data
points, which are assumed to be in a union of low-dimensional subspaces. We
show that a modified version of SSC is \emph{provably effective} in correctly
identifying the underlying subspaces, even with noisy data. This extends
theoretical guarantee of this algorithm to more practical settings and provides
justification to the success of SSC in a class of real applications.


title:
KIC 7524178 -- an SU UMa-Type Dwarf Nova Showing Predominantly Negative
  Superhumps throughout Supercycle

abstract:
  We analyzed the Kepler long cadence data of KIC 7524178 (=KIS
J192254.92+430905.4), and found that it is an SU UMa-type dwarf nova with
frequent normal outbursts. The signal of the negative superhump was always the
dominant one even during the superoutburst, in contrast to our common knowledge
about superhumps in dwarf novae. The signal of the positive superhump was only
transiently seen during the superoutburst, and it quickly decayed after the
superoutburst. The frequency variation of the negative superhump was similar to
the two previously studied dwarf novae in the Kepler field, V1504 Cyg and V344
Lyr. This is the first object in which the negative superhumps dominate
throughout the supercycle. Nevertheless, the superoutburst was faithfully
accompanied by the positive superhump, indicating that the tidal eccentric
instability is essential for triggering a superoutburst. All the pieces of
evidence strengthen the thermal-tidal instability as the origin of the
superoutburst and supercycle, making this object the third such example in the
Kepler field. This object had unusually small (~1.0 mag) outburst amplitude and
we discussed that the object has a high mass-transfer rate close to the thermal
stability limit of the accretion disk. The periods of the negative and positive
superhumps, and that of the candidate orbital period were 0.07288 d (average,
variable in the range 0.0723-0.0731 d), 0.0785 d (average, variable in the
range 0.0772-0.0788 d) and 0.074606(1) d, respectively.


title: Infinite horizon control and minimax observer design for linear DAEs

abstract:
  In this paper we construct an infinite horizon minimax state observer for a
linear stationary differential-algebraic equation (DAE) with uncertain but
bounded input and noisy output. We do not assume regularity or existence of a
(unique) solution for any initial state of the DAE. Our approach is based on a
generalization of Kalman's duality principle. The latter allows us to transform
minimax state estimation problem into a dual control problem for the adjoint
DAE: the state estimate in the original problem becomes the control input for
the dual problem and the cost function of the latter is, in fact, the
worst-case estimation error. Using geometric control theory, we construct an
optimal control in the feed-back form and represent it as an output of a stable
LTI system. The latter gives the minimax state estimator. In addition, we
obtain a solution of infinite-horizon linear quadratic optimal control problem
for DAEs.


title: Baryon inhomogeneities in a charged quark gluon plasma

abstract:
  We study the generation of baryon inhomogeneities in regions of the quark
gluon plasma which have a charge imbalance. We find that the overdensity in the
baryon lumps for positively charged particles is different from the overdensity
due to the negatively charged particles. Since quarks are charged particles,
the probability of forming neutrons or protons in the lumps would thus be
changed. The probability of forming hadrons having quarks of the same charges
would be enhanced. This might have interesting consequences for the
inhomogeneous nucleosynthesis calculations.


title:
On Lower Central Series Quotients of Finitely Generated Algebras over
  $\mathbb{Z}$

abstract:
  Let $A$ be an associative unital algebra, $B_k$ its successive quotients of
lower central series and $N_k$ the successive quotients of ideals generated by
lower central series. The geometric and algebraic aspects of $B_k$ and $N_k$
have been of great interest since the pioneering work of \cite{feigin2007}. In
this paper, we will concentrate on the case where $A$ is a noncommutative
polynomial algebra over $\mathbb{Z}$ modulo a single homogeneous relation. Both
the torsion part and the free part of $B_k$ and $N_k$ are explored. Many
examples are demonstrated in detail, and several general theorems are proved.
Finally we end up with an appendix about the torsion subgroups of
$N_k(A_n(\mathbb{Z}))$ and some open problems.


title: Parametrization of degenerate density matrices

abstract:
  This paper presents a parametrization of a degenerate density matrix. The
problem needs to be approached first with a diagonalized form (the spectral
representation) to deal with degeneracy. Such a form is useful for this
parametrization in that the conditions to be a density matrix from a Hermitian
matrix are applied only to a diagonal eigenvalue matrix, not a unitary matrix.
Those conditions can be satisfied by parametrizing eigenvalues with squared
spherical coordinates in dimension of the matrix. Degeneracy in eigenvalues
brings symmetries between a eigenvalue matrix and a unitary matrix, which are
realized in a form of a commuting unitary matrix, called a commutant. The
associated redundant parameters in a unitary matrix have to be eliminated. It
is realized in this paper that degrees of degeneracies can be defined as the
total number of possible pairs of the same eigenvalues and one degree of
degeneracy corresponds to one phase and one two dimensional rotation in a
unitary matrix or a commutant. In this way all the degeneracies are identified
and assigned to one phase-one rotation block. Therefore, a unitary matrix or a
commutant is a product of these blocks and a general diagonal phase matrix. In
physics a unitary matrix is often parametrized by rotation and phase matrices,
called an angular representation here. There are many possible different phase
configurations. It is often not a trivial matter whether a given parametrized
unitary matrix is general. A simple diagram will be introduced to illustrate
how to transform one phase configuration to another.


title:
Generation of High-Energy Photons at Ultra-Relativistic Shock Breakout
  in Supernovae

abstract:
  We present theoretical expectations for non-thermal emission due to the bulk
Comptonization at the ultra-relativistic shock breakout. We calculate the
transfer of photons emitted from the shocked matter with a Monte Carlo code
fully taking into account special relativity. As a hydrodynamical model, we use
a self-similar solution of Nakayama & Shigeyama (2005). Our calculations reveal
that the spectral shape exhibits a double peak or a single peak depending on
the shock temperature at the shock breakout. If it is significantly smaller
than the rest energy of an electron, the spectrum has a double peak. We also
display a few example of light curves, and estimate the total radiation energy.
In comparison with observations of gamma-ray bursts, a part of the higher
energy component in the spectra and the total energy can be reproduced by some
parameter sets. Meanwhile, the lower energy counterpart in the Band function is
not reproduced by our results and the duration time seems too short to
represent the entire event of a gamma-ray burst. Therefore the subsequent phase
will constitute the lower energy part in the spectrum.


title:
Radio Jets Clearing the Way Through a Galaxy: Watching Feedback in
  Action

abstract:
  The energy released by an active galactic nucleus (AGN) has a strong impact
on the surrounding interstellar medium (ISM). This feedback is considered to be
the regulating factor for the growth of the central massive black hole, and for
the rate of star formation in a galaxy. We have located, using Very Long
Baseline Interferometry (VLBI), the fast outflow of neutral hydrogen in the
young, restarted radio loud AGN 4C12.50. The outflow is located 100 pc from the
nucleus where the radio jet interacts with the ISM, as well as around the
associated radio lobe. These observations show that the radio plasma drives the
outflow and removes gas from the central regions, and that jet driven outflows
can play a relevant role in feedback mechanisms.


title:
High-contrast Aharonov-Bohm oscillations in the acoustoelectric
  transport regime

abstract:
  Phase-coherent acoustoelectric transport is reported.Aharonov-Bohm
oscillations in the acoustoelectric current with visibility exceeding 100% were
observed in mesoscopic GaAs rings as a function of an external magnetic field
at cryogenic temperatures. A theoretical analysis of the acoustoelectric
transport in ballistic devices is proposed to model experimental observations.
Our findings highlight a close analogy between acoustoelectric transport and
thermoelectric properties in ballistic devices.


title:
3d-4f spin interaction induced giant magnetocaloric effect in
  zircon-type DyCrO4 and HoCrO4 compounds

abstract:
  We have investigated the influence of 3d-4f spin interaction on magnetic and
magnetocaloric properties of DyCrO$_4$ and HoCrO$_4$ compounds by magnetization
and heat capacity measurements. Both the compounds exhibit complicated magnetic
properties and huge magnetic entropy change around the ferromagnetic transition
due to the strong competition between ferromagnetic and antiferromagnetic
superexchange interactions. For a field change of 8 T, the maximum values of
magnetic entropy change ($\Delta S_{M}^{max}$), adiabatic temperature change
($\Delta T_{ad}$), and refrigerant capacity (RC) reach 29 J kg$^{-1}$ K$^{-1}$,
8 K, and 583 J kg$^{-1}$, respectively for DyCrO$_4$ whereas the corresponding
values for HoCrO$_4$ are 31 J kg$^{-1}$ K$^{-1}$, 12 K, and 622 J kg$^{-1}$.
$\Delta S_{M}^{max}$, $\Delta T_{ad}$, and RC are also quite large for a
moderate field change. The large values of magnetocaloric parameters suggest
that the zircon-type DyCrO$_4$ and HoCrO$_4$ could be the potential magnetic
refrigerant materials for liquefaction of hydrogen.


title:
Condensation of helium in aerogels and athermal dynamics of the Random
  Field Ising Model

abstract:
  High resolution measurements reveal that condensation isotherms of $^4$He in
a silica aerogel become discontinuous below a critical temperature. We show
that this behaviour does not correspond to an equilibrium phase transition
modified by the disorder induced by the aerogel structure, but to the
disorder-driven critical point predicted for the athermal out-of-equilibrium
dynamics of the Random Field Ising Model. Our results evidence the key role of
non-equilibrium effects in the phase transitions of disordered systems.


title: On Seiffert-like means

abstract:
  We investigate the representation of homogeneous, symmetric means in the form
M(x,y)=\frac{x-y}{2f((x-y)/(x+y))}. This allows for a new approach to comparing
means. As an example, we provide optimal estimate of the form (1-\mu)min(x,y)+
\mu max(x,y)<= M(x,y)<= (1-\nu)min(x,y)+ \nu max(x,y) and
M((x+y)/2-\mu(x-y)/2,(x+y)/2+\mu(x-y)/2)<= N(x,y)<=
M((x+y)/2-\nu(x-y)/2,(x+y)/2+\nu(x-y)/2) for some known means.


title:
Optical probe of ferroelectric order in bulk and thin film perovskite
  titanates

abstract:
  We have measured the temperature dependence of the direct band gap, $E_g$, in
SrTi$^{16}$O$_3$ and BaTiO$_3$ and related materials with quantum-paraelectric
and ferroelectric properties using optical spectroscopy. We show that $E_g$
exhibits an anomalous temperature dependence with pronounced changes in the
vicinity of the ferroelectric transition that can be accounted for in terms of
the Fr\"ohlich electron-phonon interaction with an optical phonon mode, the
so-called soft mode. We demonstrate that these characteristic changes of $E_g$
can be readily detected even in very thin films of SrTi$^{16}$O$_3$ with a
strain-induced ferroelectric order. Optical spectroscopy thus can be used as a
relatively simple but sensitive probe of ferroelectric order in very thin films
of these titanates and probably also in subsequent multilayers and devices.


title:
Holonomic Decent Minimization Method for Restricted Maximum Likelihood
  Estimation

abstract:
  Recently, the school of Takemura and Takayama have developed a quite
interesting minimization method called holonomic gradient descent method (HGD).
It works by a mixed use of Pfaffian differential equation satisfied by an
objective holonomic function and an iterative optimization method. They
successfully applied the method to several maximum likelihood estimation (MLE)
problems, which have been intractable in the past. On the other hand, in
statistical models, it is not rare that parameters are constrained and
therefore the MLE with constraints has been surely one of fundamental topics in
statistics. In this paper we develop HGD with constraints for MLE .


title: Position angles and coplanarity of multiple systems from transit timing

abstract:
  Aims: We compare the apparent difference in timing of transiting planets (or
eclipsing binaries) that are observed from widely separated locations
(parallactic delay).
  Methods: A simple geometrical argument allow us to show that the apparent
timing difference depends also on the on-sky position angle of the planetary
(or secondary) orbit, relative to the ecliptic plane.
  Results: We calculate that on-sky position angle would be readily observable
using the future PLATO and CHEOPS missions data, and possibility observable
already in many known radial-velocity systems (if they exhibit transits). We
also find that on-sky coplanarity of multiple objects in the same system can be
probed more easily than the on-sky position angle of each of the objects
separately. We calculate the magnitude of the effect for all currently known
planets (should they exhibit transits), finding that almost 200 of them --
mostly radial-velocity detected planets -- have predicted timing effect larger
than 1 second. We also compute the theoretical timing precision for the PLATO
mission, that will observe a similar stellar population, and find that a 1
second effect would be frequently readily observable. We also find that on-sky
coplanarity of multiple objects in the same system can be probed more easily
than the on-sky position angle of each of the objects separately.
  Conclusions: We show a new observable from transit photometry becomes
available when very high precision transit timing is available. We find that
there is a good match between projected capabilities of the future space
missions PLATO and CHEOPS and the new observable. We give some initial science
question that such a new observable may be related to and help addressing.


title: Bounded Representations of Interval and Proper Interval Graphs

abstract:
  Klavik et al. [arXiv:1207.6960] recently introduced a generalization of
recognition called the bounded representation problem which we study for the
classes of interval and proper interval graphs. The input gives a graph G and
in addition for each vertex v two intervals L_v and R_v called bounds. We ask
whether there exists a bounded representation in which each interval I_v has
its left endpoint in L_v and its right endpoint in R_v. We show that the
problem can be solved in linear time for interval graphs and in quadratic time
for proper interval graphs.
  Robert's Theorem states that the classes of proper interval graphs and unit
interval graphs are equal. Surprisingly the bounded representation problem is
polynomially solvable for proper interval graphs and NP-complete for unit
interval graphs [Klav\'{\i}k et al., arxiv:1207.6960]. So unless P = NP, the
proper and unit interval representations behave very differently.
  The bounded representation problem belongs to a wider class of restricted
representation problems. These problems are generalizations of the
well-understood recognition problem, and they ask whether there exists a
representation of G satisfying some additional constraints. The bounded
representation problems generalize many of these problems.


title:
Measurements of cosmic rays at the highest energies with the Pierre
  Auger Observatory

abstract:
  This paper summarizes the status and the recent measurements from the Pierre
Auger Observatory. The energy spectrum is described and its features discussed.
We report searches for anisotropy of cosmic ray arrival directions on large
scales and through correlation with catalogues of celestial objects. We also
present the search for anisotropies in the data without the use of astronomical
catalogues. The first measurement of the proton-air cross section around
10^{18} eV is discussed. Finally, the mass composition is addressed with
measurements of the variation of the depth of shower maximum with energy and
with the muon density at ground.


title:
CFBDS J111807-064016: A new L/T transition brown dwarf in a binary
  system

abstract:
  Stellar-substellar binary systems are quite rare, and provide interesting
benchmarks. They constrain the complex physics of substellar atmospheres,
because several physical parameters of the substellar secondary can be fixed
from the much better characterized main sequence primary. We report the
discovery of CFBDS J111807-064016, a T2 brown dwarf companion to 2MASS
J111806.99-064007.8, a low-mass M4.5-M5 star. The brown-dwarf was identified
from the Canada France Brown Dwarf Survey. At a distance of 50-120 pc, the 7.7
arcsec angular separation corresponds to projected separations of 390-900 AU.
The primary displays no Halpha emission, placing a lower limit on the age of
the system of about 6 Gyr. The kinematics is also consistent with membership in
the old thin disc. We obtained near-infrared spectra, which together with
recent atmosphere models allow us determine the effective temperature and
gravity of both components. From these parameters and the age constraint,
evolutionary models estimate masses of 0.10 to 0.15 Msol for the M dwarf, and
0.06 to 0.07 Msol for the T dwarf. This system is a particularly valuable
benchmark because the brown dwarf is an early T: the cloud-clearing that occurs
at the L/T transition is very sensitive to gravity, metallicity, and detailed
dust properties, and produces a large scatter in the colours. This T2 dwarf,
with its metallicity measured from the primary and its mass and gravity much
better constrained than those of younger early-Ts, will anchor our
understanding of the colours of L/T transition brown dwarfs. It is also one of
the most massive T dwarfs, just below the hydrogen-burning limit, and all this
makes it a prime probe a brown dwarf atmosphere and evolution models.


title:
Pattern Matching via Choice Existential Quantifications in Imperative
  Languages

abstract:
  Selection statements -- if-then-else, switch and try-catch -- are commonly
used in modern imperative programming languages. We propose another selection
statement called a {\it choice existentially quantified statement}. This
statement turns out to be quite useful for pattern matching among several
merits. Examples will be provided for this statement.


title:
Spherical steady accretion flows -- dependence on the cosmological
  constant, exact isothermal solutions and applications to cosmology

abstract:
  We investigate spherical, isothermal and polytropic steady accretion models
in the presence of the cosmological constant. Exact solutions are found for
three classes of isothermal fluids, assuming the test gas approximation. The
cosmological constant damps the mass accretion rate and - above certain limit -
completely stops the steady accretion onto black holes. A "homoclinic-type"
accretion flow of polytropic gas has been discovered in AdS spacetimes in the
test-gas limit. These results can have cosmological connotation, through the
Einstein--Straus vacuole model of embedding local structures into
Friedman-Lemaitre-Robertson-Walker spacetimes. In particular one infers that
steady accretion would not exist in the late phases of the Penrose's scenario
of the evolution of the Universe, known as the Weyl curvature hypothesis.


title:
The Nonexistence of Certain Representations of the Absolute Galois Group
  of Quadratic Fields

abstract:
  For a quadratic field K, we investigate continuous mod p representations of
the absolute Galois groups of K that are unramified away from p and infinity.
We prove that for certain pairs (K,p), there are no such irreducible
representations. We also list some imaginary quadratic fields for which such
irreducible representations exist. As an application, we look at elliptic
curves with good reduction away from 2 over quadratic fields.


title: Strong Normalization for HA + EM1 by Non-Deterministic Choice

abstract:
  We study the strong normalization of a new Curry-Howard correspondence for HA
+ EM1, constructive Heyting Arithmetic with the excluded middle on
Sigma01-formulas. The proof-term language of HA + EM1 consists in the lambda
calculus plus an operator ||_a which represents, from the viewpoint of
programming, an exception operator with a delimited scope, and from the
viewpoint of logic, a restricted version of the excluded middle. We give a
strong normalization proof for the system based on a technique of
"non-deterministic immersion".


title: Interpreting a Classical Geometric Proof with Interactive Realizability

abstract:
  We show how to extract a monotonic learning algorithm from a classical proof
of a geometric statement by interpreting the proof by means of interactive
realizability, a realizability sematics for classical logic.
  The statement is about the existence of a convex angle including a finite
collections of points in the real plane and it is related to the existence of a
convex hull. We define real numbers as Cauchy sequences of rational numbers,
therefore equality and ordering are not decidable. While the proof looks
superficially constructive, it employs classical reasoning to handle
undecidable comparisons between real numbers, making the underlying algorithm
non-effective.
  The interactive realizability interpretation transforms the non-effective
linear algorithm described by the proof into an effective one that uses
backtracking to learn from its mistakes. The effective algorithm exhibits a
"smart" behavior, performing comparisons only up to the precision required to
prove the final statement. This behavior is not explicitly planned but arises
from the interactive interpretation of comparisons between Cauchy sequences.


title: Hereditary Substitution for the \lambda\Delta-Calculus

abstract:
  Hereditary substitution is a form of type-bounded iterated substitution,
first made explicit by Watkins et al. and Adams in order to show normalization
of proof terms for various constructive logics. This paper is the first to
apply hereditary substitution to show normalization of a type theory
corresponding to a non-constructive logic, namely the lambda-Delta calculus as
formulated by Rehof. We show that there is a non-trivial extension of the
hereditary substitution function of the simply-typed lambda calculus to one for
the lambda-Delta calculus. Then hereditary substitution is used to prove
normalization.


title: Continuation calculus

abstract:
  Programs with control are usually modeled using lambda calculus extended with
control operators. Instead of modifying lambda calculus, we consider a
different model of computation. We introduce continuation calculus, or CC, a
deterministic model of computation that is evaluated using only head reduction,
and argue that it is suitable for modeling programs with control. It is
demonstrated how to define programs, specify them, and prove them correct. This
is shown in detail by presenting in CC a list multiplication program that
prematurely returns when it encounters a zero. The correctness proof includes
termination of the program. In continuation calculus we can model both
call-by-name and call-by-value. In addition, call-by-name functions can be
applied to call-by-value results, and conversely.


title: Induction by Coinduction and Control Operators in Call-by-Name

abstract:
  This paper studies emulation of induction by coinduction in a call-by-name
language with control operators. Since it is known that call-by-name
programming languages with control operators cannot have general initial
algebras, interaction of induction and control operators is often restricted to
effect-free functions. We show that some class of such restricted inductive
types can be derived from full coinductive types by the power of control
operators. As a typical example of our results, the type of natural numbers is
represented by the type of streams. The underlying idea is a counterpart of the
fact that some coinductive types can be expressed by inductive types in
call-by-name pure language without side-effects.


title: Combining and Relating Control Effects and their Semantics

abstract:
  Combining local exceptions and first class continuations leads to programs
with complex control flow, as well as the possibility of expressing powerful
constructs such as resumable exceptions. We describe and compare games models
for a programming language which includes these features, as well as
higher-order references. They are obtained by contrasting methodologies: by
annotating sequences of moves with "control pointers" indicating where
exceptions are thrown and caught, and by composing the exceptions and
continuations monads.
  The former approach allows an explicit representation of control flow in
games for exceptions, and hence a straightforward proof of definability (full
abstraction) by factorization, as well as offering the possibility of a
semantic approach to control flow analysis of exception-handling. However,
establishing soundness of such a concrete and complex model is a non-trivial
problem. It may be resolved by establishing a correspondence with the monad
semantics, based on erasing explicit exception moves and replacing them with
control pointers.


title:
153Eu and 69,71Ga Zero-Field NMR Study of Antiferromagnetic State in
  EuGa4

abstract:
  We report $^{153}$Eu and $^{69,71}$Ga NMR under a zero magnetic field on the
antiferromagnetic state of EuGa$_{4}$ with $T_{\rm{N}}\approx 16$ K. We have
successfully observed a $^{153}$Eu zero-field NMR signal with well-resolved
nuclear quadrupole splitting in the antiferromagnetic state of EuGa$_{4}$.
$^{69,71}$Ga zero-field NMR spectra were also observed below $T_{\rm{N}}$. The
internal field and nuclear quadrupole frequency are estimated from a simulation
of the spectra by the exact diagonalization of the nuclear spin Hamiltonian
matrix. The asymmetrically split zero-field NMR spectra were explained by
considering a configuration of the magnetic moments of Eu$^{2+}$ lying in the
basal $ab$-plane. The temperature dependence of the internal field, which is
proportional to the sublattice magnetization, can be explained by the Brillouin
function with $J=S=7/2$


title: Proving termination of evaluation for System F with control operators

abstract:
  We present new proofs of termination of evaluation in reduction semantics
(i.e., a small-step operational semantics with explicit representation of
evaluation contexts) for System F with control operators. We introduce a
modified version of Girard's proof method based on reducibility candidates,
where the reducibility predicates are defined on values and on evaluation
contexts as prescribed by the reduction semantics format. We address both
abortive control operators (callcc) and delimited-control operators (shift and
reset) for which we introduce novel polymorphic type systems, and we consider
both the call-by-value and call-by-name evaluation strategies.


title: Adaptive LASSO model selection in a multiphase quantile regression

abstract:
  We propose a general adaptive LASSO method for a quantile regression model.
Our method is very interesting when we know nothing about the first two moments
of the model error. We first prove that the obtained estimators satisfy the
oracle properties, which involves the relevant variable selection without using
hypothesis test. Next, we study the proposed method when the (multiphase) model
changes to unknown observations called change-points. Convergence rates of the
change-points and of the regression parameters estimators in each phase are
found. The sparsity of the adaptive LASSO quantile estimators of the regression
parameters is not affected by the change-points estimation. If the phases
number is unknown, a consistent criterion is proposed. Numerical studies by
Monte Carlo simulations show the performance of the proposed method, compared
to other existing methods in the literature, for models with a single phase or
for multiphase models. The adaptive LASSO quantile method performs better than
known variable selection methods, as the least squared method with adaptive
LASSO penalty, $L_1$-method with LASSO-type penalty and quantile method with
SCAD penalty.


title: Switchable thermal antenna by phase transition

abstract:
  We introduce a thermal antenna which can be actively switched by phase
transition. The source makes use of periodically patterned vanadium dioxide, a
metal-insulator phase transition material which supports a surface
phonon-polariton (SPP) in the infrared range in its crystalline phase. Using
electrodes properly registred with respect to the pattern, the phase transition
of VO2 can be localy triggered within few microseconds and the SPP can be
diffracted making the thermal emission highly directionnal. This switchable
antenna could find broad applications in the domain of active thermal coatings
or in those of infrared spectroscopy and sensing.


title: Reversible Logic Elements with Memory and Their Universality

abstract:
  Reversible computing is a paradigm of computation that reflects physical
reversibility, one of the fundamental microscopic laws of Nature. In this
survey, we discuss topics on reversible logic elements with memory (RLEM),
which can be used to build reversible computing systems, and their
universality. An RLEM is called universal, if any reversible sequential machine
(RSM) can be realized as a circuit composed only of it. Since a finite-state
control and a tape cell of a reversible Turing machine (RTM) are formalized as
RSMs, any RTM can be constructed from a universal RLEM. Here, we investigate
2-state RLEMs, and show that infinitely many kinds of non-degenerate RLEMs are
all universal besides only four exceptions. Non-universality of these
exceptional RLEMs is also argued.


title: Intrinsic universality and the computational power of self-assembly

abstract:
  This short survey of recent work in tile self-assembly discusses the use of
simulation to classify and separate the computational and expressive power of
self-assembly models. The journey begins with the result that there is a single
universal tile set that, with proper initialization and scaling, simulates any
tile assembly system. This universal tile set exhibits something stronger than
Turing universality: it captures the geometry and dynamics of any simulated
system. From there we find that there is no such tile set in the
noncooperative, or temperature 1, model, proving it weaker than the full tile
assembly model. In the two-handed or hierarchal model, where large assemblies
can bind together on one step, we encounter an infinite set, of infinite
hierarchies, each with strictly increasing simulation power. Towards the end of
our trip, we find one tile to rule them all: a single rotatable flipable
polygonal tile that can simulate any tile assembly system. It seems this could
be the beginning of a much longer journey, so directions for future work are
suggested.


title: Tiling Problems on Baumslag-Solitar groups

abstract:
  We exhibit a weakly aperiodic tile set for Baumslag-Solitar groups, and prove
that the domino problem is undecidable on these groups. A consequence of our
construction is the existence of an arecursive tile set on Baumslag-Solitar
groups.


title: How to Obtain Computational Completeness in P Systems with One Catalyst

abstract:
  Whether P systems with only one catalyst can already be computationally
complete, is still an open problem. Here we establish computational
completeness by using specific variants of additional control mechanisms. At
each step using only multiset rewriting rules from one set of a finite number
of sets of multiset rewriting rules allows for obtaining computational
completeness with one catalyst and only one membrane. If the targets are used
for choosing the multiset of rules to be applied, for getting computational
completeness with only one catalyst more than one membrane is needed. If the
available sets of rules change periodically with time, computational
completeness can be obtained with one catalyst in one membrane. Moreover, we
also improve existing computational completeness results for P systems with
mobile catalysts and for P systems with membrane creation.


title:
One-dimensional Array Grammars and P Systems with Array Insertion and
  Deletion Rules

abstract:
  We consider the (one-dimensional) array counterpart of contextual as well as
insertion and deletion string grammars and consider the operations of array
insertion and deletion in array grammars. First we show that the emptiness
problem for P systems with (one-dimensional) insertion rules is undecidable.
Then we show computational completeness of P systems using (one-dimensional)
array insertion and deletion rules even of norm one only. The main result of
the paper exhibits computational completeness of one-dimensional array grammars
using array insertion and deletion rules of norm at most two.


title:
Topology and Non-Deterministic Polynomial Time Computation : Avoidance
  of The Misbehaviour of Hub-Free Diagrams and Consequences

abstract:
  To study groups with small Dehn's function, Olshanskii and Sapir developed a
new invariant of bipartite chords diagrams and applied it to hub-free
realization of S-machines. In this paper we consider this new invariant
together with groups constructed from S-machines containing the hub relation.
The idea is to study the links between the topology of the asymptotic cones and
polynomial time computations. Indeed it is known that the topology of such
metric space depends on diagrams without hubs that do not correspond to the
computations of the considered S-machine. This work gives sufficient conditions
that avoid this misbehaviour, but as we shall see the method has a significant
drawback.


title:
Satisfiability of cross product terms is complete for real
  nondeterministic polytime Blum-Shub-Smale machines

abstract:
  Nondeterministic polynomial-time Blum-Shub-Smale Machines over the reals give
rise to a discrete complexity class between NP and PSPACE. Several problems,
mostly from real algebraic geometry / polynomial systems, have been shown
complete (under many-one reduction by polynomial-time Turing machines) for this
class. We exhibit a new one based on questions about expressions built from
cross products only.


title: Hyperbolic tilings and formal language theory

abstract:
  In this paper, we try to give the appropriate class of languages to which
belong various objects associated with tessellations in the hyperbolic plane.


title: Intrinsic Universality of Causal Graph Dynamics

abstract:
  Causal graph dynamics are transformations over graphs that capture two
important symmetries of physics, namely causality and homogeneity. They can be
equivalently defined as continuous and translation invariant transformations or
functions induced by a local rule applied simultaneously on every vertex of the
graph. Intrinsic universality is the ability of an instance of a model to
simulate every other instance of the model while preserving the structure of
the computation at every step of the simulation. In this work we present the
construction of a family of intrinsically universal instances of causal graphs
dynamics, each instance being able to simulate a subset of instances.


title: On the Equivalence of Cellular Automata and the Tile Assembly Model

abstract:
  In this paper, we explore relationships between two models of systems which
are governed by only the local interactions of large collections of simple
components: cellular automata (CA) and the abstract Tile Assembly Model (aTAM).
While sharing several similarities, the models have fundamental differences,
most notably the dynamic nature of CA (in which every cell location is allowed
to change state an infinite number of times) versus the static nature of the
aTAM (in which tiles are static components that can never change or be removed
once they attach to a growing assembly). We work with 2-dimensional systems in
both models, and for our results we first define what it means for CA systems
to simulate aTAM systems, and then for aTAM systems to simulate CA systems. We
use notions of simulate which are similar to those used in the study of
intrinsic universality since they are in some sense strict, but also
intuitively natural notions of simulation. We then demonstrate a particular
nondeterministic CA which can be configured so that it can simulate any
arbitrary aTAM system, and finally an aTAM tile set which can be configured so
that it can be used to simulate any arbitrary nondeterministic CA system which
begins with a finite initial configuration.


title: A Small Universal Petri Net

abstract:
  A universal deterministic inhibitor Petri net with 14 places, 29 transitions
and 138 arcs was constructed via simulation of Neary and Woods' weakly
universal Turing machine with 2 states and 4 symbols; the total time complexity
is exponential in the running time of their weak machine. To simulate the blank
words of the weakly universal Turing machine, a couple of dedicated transitions
insert their codes when reaching edges of the working zone. To complete a chain
of a given Petri net encoding to be executed by the universal Petri net, a
translation of a bi-tag system into a Turing machine was constructed. The
constructed Petri net is universal in the standard sense; a weaker form of
universality for Petri nets was not introduced in this work.


title: A polarization identity for multilinear maps

abstract:
  Given linear spaces $E$ and $F$ over the real numbers or a field of
characteristic zero, a simple argument is given to represent a symmetric
multilinear map $u(x_1, x_2, \ldots, x_n)$ from $E^n$ to $F$ in terms of its
restriction to the diagonal. As an application, a probabilistic expression for
Gaussian variables used by Nelson and by Schetzen is derived. An Appendix by
Tom H. Koornwinder notes an even further simplification by Bochnak and Siciak
(1971) of the proof of the main result.


title:
Charm Quark Energy Loss In Infinite QCD Matter Using A Parton Cascade
  Model

abstract:
  We utilize the Parton Cascade Model to study the evolution of charm quarks
propagating through a thermal brick of QCD matter. We determine the energy loss
and the transport coefficient '$\hat{q}$' for charm quarks. The calculations
are done at a constant temperature of 350 MeV and the results are compared to
analytical calculations of heavy quark energy loss in order to validate the
applicability of using a Parton Cascade Model for the study of heavy quarks
dynamics in hot and dense QCD matter.


title: Devil's Staircases and Continued Fractions in the Josephson Junctions

abstract:
  The detailed numerical simulations of the IV-characteristics of Josephson
junction under external electromagnetic radiation show devil's staircases
within different bias current intervals. We have found that the observed steps
form very precisely continued fractions. Increasing of the amplitude of
radiation shifts the devil's staircases to higher Shapiro steps. The algorithm
of appearing and detection of the subharmonics with increasing radiation
amplitude is proposed. We demonstrate that subharmonic steps registered in the
famous experiments by A. H. Dayem and J. J. Wiegand [Phys. Rev 155, 419 (1967)]
and J. Clarke [Phys. Rev. B 4, 2963 (1971)] also form continued fractions.


title:
Extra doublets - Global analyses of Standard Model extensions in the
  fermionic or scalar sector

abstract:
  I present comprehensive analyses of the viable parameter regions of the
Standard Model of particle physics and two of its extensions: the Standard
Model with four fermion generations and the Two-Higgs-Doublets model of type
II. Applying frequentist methods, I have performed global fits which show that
the Standard Model is compatible with electroweak precision data and the
measured Higgs signal strengths. The Standard Model with four generations is
excluded by the experimental results with a p-value corresponding to more than
five standard deviations. In the Two-Higgs-Doublets model of type II, the fit
prefers the decoupling limit where it mimics the Standard Model; however,
neutral heavy Higgs boson masses below 200 GeV are still allowed.


title: The $k$-in-a-tree problem for graphs of girth at least~$k$

abstract:
  For all integers $k\geq 3$, we give an $O(n^4)$ time algorithm for the
problem whose instance is a graph $G$ of girth at least $k$ together with $k$
vertices and whose question is "Does $G$ contains an induced subgraph
containing the $k$ vertices and isomorphic to a tree?". This directly follows
for $k=3$ from the three-in-a-tree algorithm of Chudnovsky and Seymour and for
$k=4$ from a result of Derhy, Picouleau and Trotignon. Here we solve the
problem for $k\geq 5$. Our algorithm relies on a structural description of
graphs of girth at least $k$ that do not contain an induced tree covering $k$
given vertices ($k\geq 5$).


title: The Vanishing Twist in the Restricted Three Body Problem

abstract:
  This paper demonstrates the existence of twistless tori and the associated
reconnection bifurcations and meandering curves in the planar circular
restricted three-body problem. Near the Lagrangian equilibrium $\mathcal{L}_4$
a twistless torus is created near the tripling bifurcation of the short period
family. Decreasing the mass ratio leads to twistless bifurcations which are
particularly prominent for rotation numbers 3/10 and 2/7. This scenario is
studied by numerically integrating the regularised Hamiltonian flow, and
finding rotation numbers of invariant curves in a two-dimensional Poincar\'{e}
map.
  To corroborate the numerical results the Birkhoff normal form at
$\mathcal{L}_4$ is calculated to eighth order. Truncating at this order gives
an integrable system, and the rotation numbers obtained from the Birkhoff
normal form agree well with the numerical results. A global overview for the
mass ratio $\mu \in (\mu_4, \mu_3)$ is presented by showing lines of constant
energy and constant rotation number in action space.


title:
On the radius of spatial analyticity for semilinear symmetric hyperbolic
  systems

abstract:
  We study the problem of propagation of analytic regularity for semi-linear
symmetric hyperbolic systems. We adopt a global perspective and we prove that
if the initial datum extends to a holomorphic function in a strip of radius
(=width) \epsilon_0, the same happens for the solution u(t,.) for a certain
radius \epsilon(t), as long as the solution exists. Our focus is on precise
lower bounds on the spatial radius of analyticity \epsilon(t) as t grows. We
also get similar results for the Schroedinger equation with a real-analytic
electromagnetic potential.


title:
The awakening of BL Lacertae: observations by Fermi, Swift, and the
  GASP-WEBT

abstract:
  Since the launch of the Fermi satellite, BL Lacertae has been moderately
active at gamma-rays and optical frequencies until May 2011, when the source
started a series of strong flares. The exceptional optical sampling achieved by
the GLAST-AGILE Support Program (GASP) of the Whole Earth Blazar Telescope
(WEBT) in collaboration with the Steward Observatory allows us to perform a
detailed comparison with the daily gamma-ray observations by Fermi. Discrete
correlation analysis between the optical and gamma-ray emission reveals
correlation with a time lag of 0 +- 1 d, which suggests cospatiality of the
corresponding jet emitting regions. A better definition of the time lag is
hindered by the daily gaps in the sampling of the extremely fast flux
variations. In general, optical flares present more structure and develop on
longer time scales than corresponding gamma-ray flares. Observations at X-rays
and at millimetre wavelengths reveal a common trend, which suggests that the
region producing the mm and X-ray radiation is located downstream from the
optical and gamma-ray-emitting zone in the jet. The mean optical degree of
polarisation slightly decreases over the considered period and in general it is
higher when the flux is lower. The optical electric vector polarisation angle
(EVPA) shows a preferred orientation of about 15 deg, nearly aligned with the
radio core EVPA and mean jet direction. Oscillations around it increase during
the 2011-2012 outburst. We investigate the effects of a geometrical
interpretation of the long-term flux variability on the polarisation. A helical
magnetic field model predicts an evolution of the mean polarisation that is in
reasonable agreement with the observations. These can be fully explained by
introducing slight variations in the compression factor in a transverse shock
waves model.


title: The Chemical Evolution of the Milky Way: the Three Infall Model

abstract:
  We present a new chemical evolution model for the Galaxy that assumes three
main infall episodes of primordial gas for the formation of halo, thick and
thin disk, respectively. We compare our results with selected data taking into
account NLTE effects. The most important parameters of the model are (i) the
timescale for gas accretion, (ii) the efficiency of star formation and (iii) a
threshold in the gas density for the star formation process, for each Galactic
component. We find that, in order to best fit the features of the solar
neighbourhood, the halo and thick disk must form on short timescales (~0.2 and
~1.25 Gyr, respectively), while a longer timescale is required for the
thin-disk formation. The efficiency of star formation must be maximum (10
Gyr-1) during the thick-disk phase and minimum (1 Gyr-1) during the thin-disk
formation. Also the threshold gas density for star formation is suggested to be
different in the three Galactic components. Our main conclusion is that in the
framework of our model an independent episode of accretion of extragalactic
gas, which gives rise to a burst of star formation, is fundamental to explain
the formation of the thick disk. We discuss our results in comparison to
previous studies and in the framework of modern galaxy formation theories.


title: On Roussel-Rubio-type lemmas and their consequences

abstract:
  Roussel and Rubio proved a lemma which is essential in the proof of the
Strong Perfect Graph Theorem. We give a new short proof of the main case of
this lemma. In this note, we also give a short proof of Hayward's decomposition
theorem for weakly chordal graphs, relying on a Roussel--Rubio-type lemma. We
recall how Roussel--Rubio-type lemmas yield very short proofs of the existence
of even pairs in weakly chordal graphs and Meyniel graphs.


title: Universality classes of inflation

abstract:
  We investigate all single-field, slow-roll inflationary models whose
slow-roll parameters scale as 1/N in the limit of a large number of e-folds N.
We proof that all such models belong to two universality classes, characterised
by a single parameter. One class contains small field models like hilltop
inflation, while the other class consists of large field models like chaotic
inflation. We give the leading expressions for the spectral index and
tensor-to-scalar ratio r, which are universal for each class, plus subleading
corrections for a number of models. This predicts r either to be unobservably
small, r<0.01, or close to the present observational limit, r~0.07.


title:
On a Family of Circulant Matrices for Quasi-Cyclic Low-Density Generator
  Matrix Codes

abstract:
  We present a new class of sparse and easily invertible circulant matrices
that can have a sparse inverse though not being permutation matrices. Their
study is useful in the design of quasi-cyclic low-density generator matrix
codes, that are able to join the inner structure of quasi-cyclic codes with
sparse generator matrices, so limiting the number of elementary operations
needed for encoding. Circulant matrices of the proposed class permit to hit
both targets without resorting to identity or permutation matrices that may
penalize the code minimum distance and often cause significant error floors.


title: Statistics of weighted Poisson events and its applications

abstract:
  The statistics of the sum of random weights where the number of weights is
Poisson distributed has important applications in nuclear physics, particle
physics and astrophysics. Events are frequently weighted according to their
acceptance or relevance to a certain type of reaction. The sum is described by
the compound Poisson distribution (CPD) which is shortly reviewed. It is shown
that the CPD can be approximated by a scaled Poisson distribution (SPD). The
SPD is applied to parameter estimation in situations where the data are
distorted by resolution effects. It performs considerably better than the
normal approximation that is usually used. A special Poisson bootstrap
technique is presented which permits to derive confidence limits for
observations following the CPD.


title:
Nuclear magnetization in gallium arsenide quantum dots at zero magnetic
  field

abstract:
  Optical and electrical control of the nuclear spin system allows enhancing
the sensitivity of NMR applications and spin-based information storage and
processing. Dynamic nuclear polarization in semiconductors is commonly achieved
in the presence of a stabilizing external magnetic field. Here we report
efficient optical pumping of nuclear spins at zero magnetic field in strain
free GaAs quantum dots. The strong interaction of a single, optically injected
electron spin with the nuclear spins acts as a stabilizing, effective magnetic
field (Knight field) on the nuclei. We optically tune the Knight field
amplitude and direction. In combination with a small transverse magnetic field,
we are able to control the longitudinal and transverse component of the nuclear
spin polarization in the absence of lattice strain i.e. nuclear quadrupole
effects, as reproduced by our model calculations.


title:
Two-dimensional percolation phenomena of single-component linear
  homopolymer brushes

abstract:
  Percolation phenomena of homopolymer brushes on a planar substrate are
simulated using the molecular Monte Carlo method in 3 dimensions. The grafted
polymers are isolated from each other at extremely low grafting density,
whereas a continuous polymer layer covers the whole substrate when the density
rises to extremely high values. This indicates that percolation clusters of the
grafted polymers, bridging both the edges of the substrate, appear at an
intermediate density. We construct phase diagrams of this percolation
phenomenon. Critical phenomena at the transition are also studied.


title: Logspace computations in graph products

abstract:
  We consider three important and well-studied algorithmic problems in group
theory: the word, geodesic, and conjugacy problem. We show transfer results
from individual groups to graph products. We concentrate on logspace complexity
because the challenge is actually in small complexity classes, only. The most
difficult transfer result is for the conjugacy problem. We have a general
result for graph products, but even in the special case of a graph group the
result is new. Graph groups are closely linked to the theory of Mazurkiewicz
traces which form an algebraic model for concurrent processes. Our proofs are
combinatorial and based on well-known concepts in trace theory. We also use
rewriting techniques over traces. For the group-theoretical part we apply
Bass-Serre theory. But as we need explicit formulae and as we design concrete
algorithms all our group-theoretical calculations are completely explicit and
accessible to non-specialists.


title: Path-dependent rough differential equations

abstract:
  We show in this work how the machinery of C^1-approximate flows introduced in
our previous work "Flows driven by rough paths", provides a very efficient tool
for proving well-posedness results for path-dependent rough differential
equations on flows of the form d\phi = V h(dt) + F X(dt), for smooth enough
path-dependent vector fields V,F = (V_1,...,V_\ell), any Holder weak geometric
p-rough path X and any a-Holder path h, with a+1/p>1.


title: $pp$ and $\bar pp$ total cross sections and elastic scattering

abstract:
  It is shown that $p p$ and $p\bar p$ data, including those from the TOTEM
experiment, agree well with Regge theory.


title: Quantum Materials: Shape Resonances in Superstripes

abstract:
  The significance of stripes in certain high-temperature superconductors has
been hotly debated for decades. Now a consensus is emerging that there may, in
fact, be two networks of different stripes in which shape resonances play a key
role in the superconductivity.


title:
Non-existence of faithful isometric action of compact quantum groups on
  compact, connected Riemannian manifolds

abstract:
  Suppose that a compact quantum group $\clq$ acts faithfully on a smooth,
compact, connected manifold $M$, i.e. has a $C^*$ (co)-action $\alpha$ on
$C(M)$, such that the action $\alpha$ is isometric in the sense of
\cite{Goswami} for some Riemannian structure on $M$.
  We prove that $\clq$ must be commutative as a $C^{\ast}$ algebra i.e.
$\clq\cong C(G)$ for some compact group $G$ acting smoothly on $M$. In
particular, the quantum isometry group of $M$ (in the sense of \cite{Goswami})
coincides with $C(ISO(M))$.


title:
Persistent photoconductivity in oxygen deficient YBCO/LCMO superlattices
  grown by PLD

abstract:
  We report a large persistent photoconductivity (PPC) in oxygen reduced PLD
grown YBa2Cu3O7-{\delta}/La2/3Ca1/3MnO3-y (YBCO/LCMO) superlattices scaling
with the oxygen deficiency and being similar to that observed in single layer
YBa2Cu3O7-{\delta} films. These results contradict previous observations where
in sputtered bilayer samples only a transient photoconductivity (TPC) was
found. We argue that the PPC effect in superlattices is caused by the PPC
effect due to the YBa2Cu3O7-x layers with limited charge transfer to
La2/3Ca1/3MnO3-y. The discrepancy arises from the different permeability of
charges across the interface and shed light on the sensitivity of oxide
interface properties on details of their preparation.


title:
Regression with an infinite number of observations applied to estimating
  the parameters of the stable distribution using the empirical characteristic
  function

abstract:
  A function of the empirical characteristic function,exists for the stable
distribution, which leads to a linear regression and can be used to estimate
the parameters. Two approaches are often used, one to find optimal values of t,
but these points are dependent on the unknown parameters. And using a fixed
number of values for t. In this work the results when all points in an interval
is used, thus where least squares using an infinite number of observations,is
approximated. It was found that this procedure performs good in small samples.


title:
Amplification and passing through the barrier of the exciton condensed
  phase pulse in double quantum wells

abstract:
  The peculiarities and the possibility of a control of exciton condensed pulse
movement in semiconductor double quantum well under the slot in the metal
electrode are studied. The condensed phase is considered phenomenologically
with the free energy in Landau-Ginzburg form taking into account the finite
value of the exciton lifetime. It was shown that the exciton condensed phase
pulse in the presence of an external linear potential moves along the slot
direction with a constant value of a maximum density during exciton lifetime,
while the exciton gas phase pulse is blurred. The penetration of the exciton
condensed phase pulse through the barrier and its stopping by the barrier are
studied. Also, it was shown that the exciton pulse in the condensedphase can be
amplified and recovered after damping by imposing an additional laser pulse.
Solutions for the system of excitons in double quantum well under the slot in
the electrode under steady-state irradiation in the form of bright and dark
autosolitons were found.


title:
Multi-wavelength landscape of the young galaxy cluster RXJ1257.2+4738 at
  z=0.866: I. The infrared view

abstract:
  We performed a thorough analysis of the star formation activity in the young
massive galaxy cluster RXJ1257+4738 at z=0.866, with emphasis on the
relationship between the local environment of the cluster galaxies and their
star formation activity. We present an optical and IR study that benefited from
the large amount of data available for this cluster, including new OSIRIS/GTC
and Herschel imaging observations. Using a optical-to-NIR multi-wavelength
catalogue, we measured photometric redshifts through a chi2 SED-fitting
procedure. We implemented a reliable and carefully chosen cluster membership
selection criterion including Monte Carlo simulations and derived a sample of
292 reliable cluster member galaxies for which we measured the following
properties: optical colours, stellar masses, ages, ultraviolet luminosities and
local densities. Using the MIPS 24um and Herschel data, we measured total IR
luminosities and SFR. Of the sample of 292 cluster galaxies, 38 show FIR
emission with an SFR between 0.5 and 45 Msun/yr. The spatial distribution of
the FIR emitters within the cluster density map and the filament-like
overdensities observed suggest that RXJ1257 is not virialised, but is in the
process of assembly. The average star formation as a function of the cluster
environment parametrised by the local density of galaxies does not show any
clear trend. However, the fraction of SF galaxies unveils that the cluster
intermediate-density regions is preferred for the SF activity to enhance, since
we observe a significant increase of the FIR-emitter fraction in this
environment. Focusing on the optically red SF galaxies, we can support the
interpretation of this population as dusty red galaxies, since we observe an
appreciable difference in their extinction compared with the blue population.


title: Reducibility of Killing tensors in d>4 NHEK geometry

abstract:
  An extremal rotating black hole in arbitrary dimension, along with time
translations and rotations, possesses a number of hidden symmetries
characterized by the second rank Killing tensors. As is known, in the near
horizon limit the isometry group of the metric is enhanced to include the
conformal factor SO(2,1). It is demonstrated that for the near horizon extremal
Kerr (NHEK) geometry in arbitrary dimension one of the Killing tensors
decomposes into a quadratic combination of the Killing vectors corresponding to
the conformal group, while the rest is functionally independent.


title: Electrical Structure-Based PMU Placement in Electric Power Systems

abstract:
  Recent work on complex networks compared the topological and electrical
structures of the power grid, taking into account the underlying physical laws
that govern the electrical connectivity between various components in the
network. A distance metric, namely, resistance distance was introduced to
provide a more comprehensive description of interconnections in power systems
compared with the topological structure, which is based only on geographic
connections between network components. Motivated by these studies, in this
paper we revisit the phasor measurement unit (PMU) placement problem by
deriving the connectivity matrix of the network using resistance distances
between buses in the grid, and use it in the integer program formulations for
several standard IEEE bus systems. The main result of this paper is rather
discouraging: more number of PMUs are required, compared with those obtained
using the topological structure, to meet the desired objective of complete
network observability without zero injection measurements. However, in light of
recent advances in the electrical structure of the grid, our study provides a
more realistic perspective of PMU placement in power systems. By further
exploring the connectivity matrix derived using the electrical structure, we
devise a procedure to solve the placement problem without resorting to linear
programming.


title: Extreme lattices: symmetries and decorrelations

abstract:
  We study statistical and structural properties of extreme lattices, which are
the local minima in the density landscape of lattice sphere packings, in
$d$-dimensional Euclidean space $\mathbb{R}^d$. Specifically, we ascertain the
distributions of densities, kissing numbers and numbers of symmetries of the
packings across a wide range of dimensions using the stochastic Voronoi
algorithm. The degree to which the packings decorrelate as well as the
correlations between the density maxima as the space dimension increases is
also investigated. We find that the extreme lattices decorrelate with
increasing dimension, the least symmetric lattices decorrelate faster. The
extreme lattices in a fixed dimension of space $d$ ($d\geq 8$) are dominated by
typical lattices that have similar packing properties, like packing densities
and kissing numbers, while the best and the worst packers are in the long tails
of the distribution of the extreme lattices.


title: Weighted Calderon-Zygmund and Rellich inequalities in L^p

abstract:
  We find necessary and sufficient conditions for the validity of weighted
Rellich and Calderon-Zygmund inequalities in L^p, 1 \leq p \leq \infty, in the
whole space and in the half-space with Dirichlet boundary conditions. General
operators like L=\Delta+c\frac{x}{|x|^2}\cdot\nabla-\frac{b}{|x|^2} are
considered. We compute best constants in some situations.


title: Symmetry breaking cilia-driven flow in the zebrafish embryo

abstract:
  Fluid mechanics plays a vital role in early vertebrate embryo development, an
example being the establishment of left-right asymmetry. Following the
dorsal-ventral and anterior-posterior axes, the left-right axis is the last to
be established; in several species it has been shown that an important process
involved with this is the production of a left-right asymmetric flow driven by
'whirling' cilia. It has previously been established in experimental and
mathematical models of the mouse ventral node that the combination of a
consistent rotational direction and posterior tilt creates left-right
asymmetric flow. The zebrafish organising structure, Kupffer's vesicle, has a
more complex internal arrangement of cilia than the mouse ventral node;
experimental studies show the flow exhibits an anticlockwise rotational motion
when viewing the embryo from the dorsal roof, looking in the ventral direction.
Reports of the arrangement and configuration of cilia suggest two possible
mechanisms for the generation of this flow from existing axis information: (1)
posterior tilt combined with increased cilia density on the dorsal roof, and
(2) dorsal tilt of 'equatorial' cilia. We develop a mathematical model of
symmetry breaking cilia-driven flow in Kupffer's vesicle using the regularized
Stokeslet boundary element method. Computations of the flow produced by tilted
whirling cilia in an enclosed domain suggest that a possible mechanism capable
of producing the flow field with qualitative and quantitative features closest
to those observed experimentally is a combination of posteriorly tilted roof
and floor cilia, and dorsally tilted equatorial cilia.

categories: physics.flu-dyn cond-mat.soft physics.bio-ph q-bio.OT


title: On Removable Sets For Convex Functions

abstract:
  In the present article we provide a sufficient condition for a closed set F
in R^d to have the following property which we call c-removability: Whenever a
function f:R^d->R is locally convex on the complement of F, it is convex on the
whole R^d. We also prove that no generalized rectangle of positive Lebesgue
measure in R^2 is c-removable. Our results also answer the following question
asked in an article by Jacek Tabor and Jozef Tabor [J. Math. Anal. Appl. 365
(2010)]: Assume the closed set F in R^d is such that any locally convex
function defined on R^d\F has a unique convex extension on R^d. Is F
necessarily intervally thin (a notion of smallness of sets defined by their
"essential transparency" in every direction)? We prove the answer is negative
by finding a counterexample in R^2.


abstract:
  In this paper we prove a version of the Berman-Konsowa principle for
reversible Markov jump processes on Polish spaces. The Berman-Konsowa principle
provides a variational formula for the capacity of a pair of disjoint
measurable sets. There are two versions, one involving a class of probability
measures for random finite paths from one set to the other, the other involving
a class of finite unit flows from one set to the other. The Berman-Konsowa
principle complements the Dirichlet principle and the Thomson principle, and
turns out to be especially useful for obtaining sharp estimates on crossover
times in metastable interacting particle systems.


title:
The Berlin Exoplanet Search Telescope II. Catalog of Variable Stars. I.
  Characterization of Three Southern Target Fields

abstract:
  A photometric survey of three Southern target fields with BEST II yielded the
detection of 2,406 previously unknown variable stars and an additional 617
stars with suspected variability. This study presents a catalog including their
coordinates, magnitudes, light curves, ephemerides, amplitudes, and type of
variability. In addition, the variability of 17 known objects is confirmed,
thus validating the results. The catalog contains a number of known and new
variables that are of interest for further astrophysical investigations, in
order to, e.g., search for additional bodies in eclipsing binary systems, or to
test stellar interior models.
  Altogether, 209,070 stars were monitored with BEST II during a total of 128
nights in 2009/2010. The overall variability fraction of 1.2-1.5% in these
target fields is well comparable to similar ground-based photometric surveys.
Within the main magnitude range of $R\in\left[11,17\right]$, we identify
0.67(3)% of all stars to be eclipsing binaries, which indicates a completeness
of about one third for this particular type in comparison to space surveys.


title: C++11 -- idea r-warto\'sci i przenoszenia

abstract:
  This paper presents a review of some new futures introduced to C++ language
by ISO/IEC 14882:2011 standard (known as C++11). It describes the ideas of
r-values and move constructors.
  ----
  Niniejszy artyku{\l} jest jednym z serii artyku{\l}\'ow w kt\'orych zawarto
przegl{\ka}d nowych element\'ow j{\ke}zyka C++ wprowadzonych przez standard
ISO/IEC 14882:2011, znany pod nazw{\ka} C++11. W artykule przedstawiono nowe
mo\.zliwo\'sci zwi{\ka}zane z przekazywaniem parametr\'ow i pisaniem
konstruktor\'ow. Zawarto w nim dok{\l}adne om\'owienie idei r-warto\'sci i
przenoszenia obiekt\'ow.


title: PGNAA neutron source moderation setup optimization

abstract:
  Monte Carlo simulations were carried out to design a prompt {\gamma}-ray
neutron activation analysis (PGNAA) thermal neutron output setup using MCNP5
computer code. In these simulations the moderator materials, reflective
materials and structure of the PGNAA 252Cf neutrons of thermal neutron output
setup were optimized. Results of the calcuations revealed that the thin layer
paraffin and the thick layer of heavy water moderated effect is best for 252Cf
neutrons spectrum. The new design compared with the conventional neutron source
design, the thermal neutron flux and rate were increased by 3.02 times and 3.27
times. Results indicate that the use of this design should increase the neutron
flux of prompt gamma-ray neutron activation analysis significantly.


title: Detection of multiple structural breaks in multivariate time series

abstract:
  We propose a new nonparametric procedure for the detection and estimation of
multiple structural breaks in the autocovariance function of a multivariate
(second- order) piecewise stationary process, which also identifies the
components of the series where the breaks occur. The new method is based on a
comparison of the estimated spectral distribution on different segments of the
observed time series and consists of three steps: it starts with a consistent
test, which allows to prove the existence of structural breaks at a controlled
type I error. Secondly, it estimates sets containing possible break points and
finally these sets are reduced to identify the relevant structural breaks and
corresponding components which are responsible for the changes in the
autocovariance structure. In contrast to all other methods which have been
proposed in the literature, our approach does not make any parametric
assumptions, is not especially designed for detecting one single change point
and addresses the problem of multiple structural breaks in the autocovariance
function directly with no use of the binary segmentation algorithm. We prove
that the new procedure detects all components and the corresponding locations
where structural breaks occur with probability converging to one as the sample
size increases and provide data-driven rules for the selection of all
regularization parameters. The results are illustrated by analyzing financial
returns, and in a simulation study it is demonstrated that the new procedure
outperforms the currently available nonparametric methods for detecting breaks
in the dependency structure of multivariate time series.


title:
Capillary Fluctuations and Film-Height-Dependent Surface Tension of an
  Adsorbed Liquid Film

abstract:
  Our understanding of both structure and dynamics of adsorbed liquids heavily
relies on the capillary wave Hamiltonian, but a thorough test of this model is
still lacking. Here we study the capillary wave fluctuations of a liquid film
with short range forces adsorbed on a solid exhibiting van der Waals
interactions. We show for the first time that the measured capillary wave
spectrum right above the first order wetting transition provides an interface
potential consistent with independent calculations from thermodynamic
integration. However, the surface tension exhibits an oscillatory film thick
dependence which reveals a hitherto unnoticed capillary wave broadening
mechanism beyond mere interfacial displacements.


title:
PDF uncertainties in the extraction of the W mass at LHC: a Snowmass
  Whitepaper

abstract:
  The precision measurement of the W boson mass is an important milestone for
the LHC physics program in the coming years. An accurate measurement of $M_W$
allows to perform stringent consistency tests of the Standard Model by means of
global electroweak fits, which in turn are sensitive to New Physics at scales
potentially higher than the ones explored in direct searches. From the
theoretical point of view, our limited knowledge of PDFs will be one of the
dominant sources of uncertainty in ongoing and future LHC determinations of
$M_W$. In this whitepaper, we have quantified the impact of PDF uncertainties
in the W mass extractions from the transverse mass distribution at the LHC. The
calculation has been performed using the NNPDF2.3 set, which includes direct
constrains on the W boson production kinematics with data for electroweak gauge
boson production from the LHC. Our results confirm previous estimates that PDF
uncertainties in the determination of $M_W$ from the $m_W^T$ distribution are
moderate, around 10 MeV at most. We briefly discuss also the case of the lepton
$p_T$ distribution.


title: Excluding induced subdivisions of the bull and related graphs

abstract:
  For any graph $H$, let ${\rm Forb}^*(H)$ be the class of graphs with no
induced subdivision of $H$. It was conjectured in [A.D. Scott, Induced trees in
graphs of large chromatic number, {\em Journal of Graph Theory}, 24:297--311,
1997] that, for every graph $H$, there is a function $f_H:\mathbb{N}
\rightarrow \mathbb{R}$ such that for every graph $G \in {\rm Forb}^*(H)$,
$\chi(G) \leq f_H(\omega(G))$. We prove this conjecture for several graphs $H$,
namely the paw (a triangle with a pendant edge), the bull (a triangle with two
vertex-disjoint pendant edges), and what we call a "necklace," that is, a graph
obtained from a path by choosing a matching such that no edge of the matching
is incident with an endpoint of the path, and for each edge of the matching,
adding a vertex adjacent to the ends of this edge.


title: Skyrmions in the Skyrme model revisited

abstract:
  The possible boundary value problems of the skyrmions are reexamined in the
original Skyrme model with two new viewpoints. The first one suggests to
replace the infinity boundary point by the finite radius R, which is related to
the density of the surrounding nuclear matter. The second viewpoint suggests to
combine the global analysis with the numerical computation to give better
results by avoiding the errors. It is interesting that the half integer
topological skyrmions do exist in the model. Finally, the static properties of
all possible skyrmions are calculated with the model parameters Subscript[F,
\[Pi]] = 186 MeV, Subscript[m, \[Pi]]= 138 MeV and 1.57 < e < 4.17. The baryon
masses are found to be too high compared to the experimental values, while the
mass splitting between them is too small. On the other hand, the isoscalar
radii and the axial coupling constant can be fitted with the experimental data
with an error of 20% within the Balachandra's bound.


title: The SUMER Data in the SOHO Archive

abstract:
  We have released an archive of all observational data of the VUV spectrometer
Solar Ultraviolet Measurements of Emitted Radiation (SUMER) on SOHO that has
been acquired until now. The operational phase started with 'first light'
observations on 27 January 1996 and will end in 2014. Future data will be added
to the archive when they become available. The archive consists of a set of raw
data (Level 0) and a set of data that are processed and calibrated to the best
knowledge we have today (Level 1). This communication describes step by step
the data acquisition and processing that has been applied in an automated
manner to build the archive. It summarizes the expertise and insights into the
scientific use of SUMER spectra that has accumulated over the years. It also
indicates possibilities for further enhancement of the data quality. With this
article we intend to convey our own understanding of the instrument performance
to the scientific community and to introduce the new, standard-FITS-format
database.


title: Super dominating sets in graphs

abstract:
  Let $G=(V,E)$ be a graph. A subset $D$ of $V(G)$ is called a super dominating
set if for every $v \in V(G)-D$ there exists an external private neighbour of
$v$ with respect to $V(G)-D.$ The minimum cardinality of a super dominating set
is called the super domination number of $G$ and is denoted by
$\gamma_{sp}(G)$. In this paper some results on the super domination number are
obtained. We prove that if $T$ is a tree with at least three vertices, then
$\frac{n}{2}\leq\gamma_{sp}(T)\leq n-s,$ where $s$ is the number of support
vertices in $T$ and we characterize the extremal trees.


title:
SteatoNet- Modelling steatosis identifies candidate systemic flux
  distribution deregulations

abstract:
  The functional diversity in factors identified in association with
non-alcoholic fatty liver disease (NAFLD) necessitates the utilization of
holistic approaches to investigate the network properties of NAFLD
pathogenesis. We describe the generation of the first mouse-specific
multi-tissue metabolic model, the SteatoNet, to investigate NAFLD-related
steatosis, by utilising an object-oriented modelling approach and incorporating
numerous hepatic metabolic pathways, their interaction with peripheral tissues
and hierarchical feedback regulation at the transcriptional and
post-translational level. The unique validated model is based on steady-state
analysis of ordinary differential equations that allows investigation of
systemic behaviour in the absence of estimated kinetic parameters. Model
analysis indicated the importance of the metabolic flux distribution parameter
in controlling metabolite concentration and identified critical focal points in
the network that may play a pivotal role in initiating NAFLD. Albeit requiring
experimental validation, the candidate triggers identified by SteatoNet provide
insight into the network properties of NAFLD and emphasize the promising scope
and potential of SteatoNet as a primary investigative tool for hypotheses
generation and exploring related metabolic diseases.


title:
Propagation of internal errors in explicit Runge--Kutta methods and
  internal stability of SSP and extrapolation methods

abstract:
  In practical computation with Runge--Kutta methods, the stage equations are
not satisfied exactly, due to roundoff errors, algebraic solver errors, and so
forth. We show by example that propagation of such errors within a single step
can have catastrophic effects for otherwise practical and well-known methods.
We perform a general analysis of internal error propagation, emphasizing that
it depends significantly on how the method is implemented. We show that for a
fixed method, essentially any set of internal stability polynomials can be
obtained by modifying the implementation details. We provide bounds on the
internal error amplification constants for some classes of methods with many
stages, including strong stability preserving methods and extrapolation
methods. These results are used to prove error bounds in the presence of
roundoff or other internal errors.


title:
Magnetic interactions in disordered perovskite PbFe_{1/2}Nb_{1/2}O_3 and
  related compounds. Dominance of nearest-neighbor interaction

abstract:
  We show that the magnetism of double perovskite AFe_{1/2}M_{1/2}O_3 systems
may be described by the Heisenberg model on the simple cubic lattice, where
only half of sites are occupied by localized magnetic moments. The
nearest-neighbor interaction J_1 is more than 20 times the next-nearest
neighbor interaction J_2, the third-nearest interaction along the space
diagonal of the cube being negligible. We argue that the variety of magnetic
properties observed in different systems is connected with the variety of
chemical ordering in them. We analyze six possible types of the chemical
ordering in 2x2x2 supercell, and argue that the probability to find them in a
real compound does not correspond to a random occupation of lattice sites by
magnetic ions. The exchange J_2 rather than J_1 define the magnetic energy
scale of most double perovskite compounds that means the enhanced probability
of 1:1 short range ordering. Two multiferroic compounds PbFe_{1/2}M_{1/2}O_3
(M=Nb, Ta) are exceptions. We show that the relatively high temperature of
antiferromagnetic transition is compatible with a layered short-range chemical
order, which was recently shown to be most stable for these two compounds [I.
P. Raevski, {\em et al.}, Phys.\ Rev.\ B \textbf{85}, 224412 (2012)]. We show
also that one of the types of ordering has ferrimagnetic ground state. The
clusters with short-range order of this type may be responsible for a
room-temperature superparamagnetism, and may form the cluster glass at low
temperatures.


title:
Characterization of the Least Periods of the Generalized Self-Shrinking
  Sequences

abstract:
  In 2004, Y. Hu and G. Xiao introduced the generalized self-shrinking
generator, a simple bit-stream generator considered as a specialization of the
shrinking generator as well as a generalization of the self-shrinking
generator. The authors conjectured that the family of generalized
self-shrinking sequences took their least periods in the set {1, 2, 2**(L-1)},
where L is the length of the Linear Feedback Shift Register included in the
generator. In this correspondence, it is proved that the least periods of such
generated sequences take values exclusively in such a set. As a straight
consequence of this result, other characteristics of such sequences (linear
complexity or pseudorandomness) and their potential use in cryptography are
also analyzed.


title: Kaluza-Klein wormholes with the compactified fifth dimension

abstract:
  We consider wormhole solutions in five-dimensional Kaluza-Klein gravity in
the presence of a massless ghost four-dimensional scalar field. The system
possesses two types of topological nontriviality connected with the presence of
the scalar field and of a magnetic charge. Mathematically, the presence of the
charge appears in the fact that the $S^3$ part of a spacetime metric is the
Hopf bundle $S^3 \rightarrow S^2$ with fibre $S^1$. We show that the fifth
dimension spanned on the sphere $S^1$ is compactified in the sense that
asymptotically, at large distances from the throat, the size of $S^1$ is equal
to some constant, the value of which can be chosen to lie, say, in the Planck
region. Then, from the four-dimensional point of view, such a wormhole contains
a radial magnetic (monopole) field, and an asymptotic four-dimensional observer
sees a wormhole with the compactified fifth dimension.


title: Asymmetric galaxy correlation functions

abstract:
  We study the two-point cross-correlation function between two populations of
galaxies: for instance a bright population and a faint population. We show that
this cross-correlation is asymmetric under the exchange of the line-of-sight
coordinate of the galaxies, i.e. that the correlation is different if the
bright galaxy is in front of, or behind, the faint galaxy. We give an
intuitive, quasi-Newtonian derivation of all the effects that contribute to
such an asymmetry in large-scale structure: gravitational redshift, Doppler
shift, lensing, light-cone, evolution and Alcock-Paczynski effects -
interestingly, the gravitational redshift term is exactly canceled by some of
the others, assuming geodesic motion. Most of these effects are captured by
previous calculations of general relativistic corrections to the observed
galaxy density fluctuation; the asymmetry arises from terms that are suppressed
by the ratio H/k - H is the Hubble constant and k is the wavenumber - which are
more readily observable than the terms suppressed by (H/k)^2. Some of the
contributions to the asymmetry, however, arise from terms that are generally
considered 'Newtonian' - the lensing and evolution - and thus represent a
contaminant in the search for general relativistic corrections. We propose
methods to disentangle these different contributions. A simple method reduces
the contamination to a level of < 10% for redshifts z<1. We also clarify the
relation to recent work on measuring gravitational redshifts by stacking
clusters.


title:
Unimodality of the Betti numbers for Hamiltonian circle action with
  isolated fixed points

abstract:
  Let $(M,\omega)$ be an eight-dimensional closed symplectic manifold equipped
with a Hamiltonian circle action with only isolated fixed points. In this
article, we will show that the Betti numbers of $M$ are unimodal, i.e. $b_0(M)
\leq b_2(M) \leq b_4(M)$.


title: From Instantly Decodable to Random Linear Network Coding

abstract:
  Our primary goal in this paper is to traverse the performance gap between two
linear network coding schemes: random linear network coding (RLNC) and
instantly decodable network coding (IDNC) in terms of throughput and decoding
delay. We first redefine the concept of packet generation and use it to
partition a block of partially-received data packets in a novel way, based on
the coding sets in an IDNC solution. By varying the generation size, we obtain
a general coding framework which consists of a series of coding schemes, with
RLNC and IDNC identified as two extreme cases. We then prove that the
throughput and decoding delay performance of all coding schemes in this coding
framework are bounded between the performance of RLNC and IDNC and hence
throughput-delay tradeoff becomes possible. We also propose implementations of
this coding framework to further improve its throughput and decoding delay
performance, to manage feedback frequency and coding complexity, or to achieve
in-block performance adaption. Extensive simulations are then provided to
verify the performance of the proposed coding schemes and their
implementations.


title:
Kondo effect and spin quenching in high-spin molecules on metal
  substrates

abstract:
  Using a state-of-the art combination of density functional theory and
impurity solver techniques we present a complete and parameter-free picture of
the Kondo effect in the high-spin ($S=3/2$) coordination complex known as
Manganese Phthalocyanine adsorbed on the Pb(111) surface. We calculate the
correlated electronic structure and corresponding tunnel spectrum and find an
asymmetric Kondo resonance, as recently observed in experiments. Contrary to
previous claims, the Kondo resonance stems from only one of three possible
Kondo channels with origin in the Mn 3d-orbitals, its peculiar asymmetric shape
arising from the modulation of the hybridization due to strong coupling to the
organic ligand. The spectral signature of the second Kondo channel is strongly
suppressed as the screening occurs via the formation of a many-body singlet
with the organic part of the molecule. Finally, a spin-1/2 in the 3d-shell
remains completely unscreened due to the lack of hybridization of the
corresponding orbital with the substrate, hence leading to a spin-3/2
underscreened Kondo effect.


title: Towards the C^0 flux conjecture

abstract:
  In this note, we generalise a result of Lalonde, McDuff and Polterovich
concerning the $ C^0 $ flux conjecture, thus confirming the conjecture in new
cases of a symplectic manifold. Also, we prove the continuity of the flux
homomorphism on the space of smooth symplectic isotopies endowed with the $ C^0
$ topology, which implies the $ C^0 $ rigidity of Hamiltonian paths,
conjectured by Seyfaddini.


title: Summary of progress on the Blaschke conjecture

abstract:
  The Blaschke conjecture claims that every compact Riemannian manifold whose
injectivity radius equals its diameter is, up to constant rescaling, a compact
rank one symmetric space. We summarize the intuition behind this problem, the
proof that such manifolds have the cohomology of compact rank one symmetric
spaces, and the proof of the conjecture for homology spheres and homology real
projective spaces. We also summarize what is known on the diffeomorphism,
homeomorphism and homotopy types of such manifolds.