title:
Bi-invariant metrics and quasi-morphisms on groups of Hamiltonian
  diffeomorphisms of surfaces

abstract:
  Let \Sigma_g be a closed orientable surface let Diff_0(\Sigma_g; area) be the
identity component of the group of area-preserving diffeomorphisms of \Sigma_g.
In this work we present an extension of Gambaudo-Ghys construction to the case
of a closed hyperbolic surface \Sigma_g, i.e. we show that every non-trivial
homogeneous quasi-morphism on the braid group on n strings of \Sigma_g defines
a non-trivial homogeneous quasi-morphism on the group Diff_0(\Sigma_g; area).
As a consequence we give another proof of the fact that the space of
homogeneous quasi-morphisms on Diff_0(\Sigma_g; area) is infinite dimensional.
  Let Ham(\Sigma_g) be the group of Hamiltonian diffeomorphisms of \Sigma_g. As
an application of the above construction we construct two injective
homomorphisms from Z^m to Ham(\Sigma_g), which are bi-Lipschitz with respect to
the word metric on Z^m and the autonomous and fragmentation metrics on
Ham(\Sigma_g). In addition, we construct a new infinite family of Calabi
quasi-morphisms on Ham(\Sigma_g).


title:
The puzzle of metallicity and multiple stellar populations in the
  Globular Clusters in Fornax

abstract:
  We examine the photometric data for Fornax clusters, focussing our attention
on their horizontal branch color distribution and, when available, on the RR
Lyr variables fraction and period distribution. Based on our understanding of
the HB morphology in terms of varying helium content in the context of multiple
stellar generations, we show that clusters F2, F3 and F5 must contain
substantial fractions of second generation stars (~54-65%). On the basis of a
simple chemical evolution model we show that the helium distribution in these
clusters can be reproduced by models with cluster initial masses ranging from
values equal to ~4 to ~10 times larger than the current masses. Models with a
very short second generation star formation episode can also reproduce the
observed helium distribution but require larger initial masses up to about
twenty times the current mass. While the lower limit of this range of possible
initial GC masses is consistent with those suggested by the observations of the
low metallicity field stars, we also discuss the possibility that the
metallicity scale of field stars (based on CaII triplet spectroscopy) and the
metallicities derived for the clusters in Fornax may not be consistent with
each other. The reproduction of the HB morphology in F2,F3,F5 requires two
interesting hypotheses: 1) the first generation HB stars lie all at "red"
colours. According to this interpretation, the low metallicity stars in the
field of Fornax, populating the HB at colours bluer than the blue side
((V-I)o<=0.3 or (B-V)o<=0.2) of the RR Lyrs, should be second generation stars
born in the clusters;a preliminary analysis of available colour surveys of
Fornax field provides a fraction ~20% of blue HB stars, in the low metallicity
range; 2) the mass loss from individual second generation red giants is a few
percent of a solar mass larger than the mass loss from first generation stars.


title:
QCD Equation of State From a Chiral Hadronic Model Including Quark
  Degrees of Freedom

abstract:
  This work presents an effective model for strongly interacting matter and the
QCD equation of state (EoS). The model includes both hadron and quark degrees
of freedom and takes into account the transition of chiral symmetry restoration
as well as the deconfinement phase transition. At low temperatures $T$ and
baryonic densities $\rho_B$ a hadron resonance gas is described using a
SU(3)-flavor sigma-omega model and a quark phase is introduced in analogy to
PNJL models for higher $T$ and $\rho_B$. In this way, the correct asymptotic
degrees of freedom are used in a wide range of $T$ and $\rho_B$. Here, results
of this model concerning the chiral and deconfinement phase transitions and
thermodynamic model properties are presented. Large hadron resonance
multiplicities in the transition region emphasize the importance of heavy-mass
resonance states in this region and their impact on the chiral transition
behavior. The resulting phase diagram of QCD matter at small chemical
potentials is in line with latest lattice QCD and thermal model results.


title: Evidence for Semileptonic B- to p pbar l nubar Decays

abstract:
  We find evidence for the semileptonic baryonic decay $B^-\to p\bar
p\ell^-\bar\nu_\ell$ ($\ell=e,\mu$), based on a data sample of 772 million
$B\bar B$ pairs collected at the $\Upsilon(4S)$ resonance with the Belle
detector at the KEKB asymmetric-energy electron-positron collider. A
neural-network based hadronic $B$-meson tagging method is used in this study.
The branching fraction of $B^-\to p\bar p\ell^-\bar\nu_\ell$ is measured to be
$(5.8^{+2.4}_{-2.1}\textrm{(stat.)}\pm 0.9\textrm{(syst.)})\times 10^{-6}$ with
a significance of 3.2$\sigma$, where lepton universality is assumed. We also
estimate the corresponding upper limit: $\mathcal{B}(B^-\to p\bar
p\ell^-\bar\nu_\ell) < 9.6\times 10^{-6}$ at the 90% confidence level. This
measurement helps constrain the baryonic transition form factor in B decays.


title: First comparison of wave observations from CoMP and AIA/SDO

abstract:
  Waves have long been thought to contribute to the heating of the solar corona
and the generation of the solar wind. Recent observations have demonstrated
evidence of quasi-periodic longitudinal disturbances and ubiquitous transverse
wave propagation in many different coronal environments. This paper
investigates signatures of different types of oscillatory behaviour, both above
the solar limb and on-disk, by comparing findings from the Coronal
Multi-channel Polarimeter (CoMP) and the Atmospheric Imaging Assembly (AIA) on
board the Solar Dynamics Observatory (SDO) for the same active region. We study
both transverse and longitudinal motion by comparing and contrasting
time-distance images of parallel and perpendicular cuts along/across active
region fan loops. Comparisons between parallel space-time features in CoMP
Doppler velocity and transverse oscillations in AIA images are made, together
with space-time analysis of propagating quasi-periodic intensity features seen
near the base of loops in AIA. Signatures of transverse motions are observed
along the same magnetic structure using CoMP Doppler velocity
(Vphase=600-750km/s, P=3-6mins) and in AIA/SDO above the limb (P=3-8mins).
Quasi-periodic intensity features (Vphase=100-200km/s, P=6-11mins) also travel
along the base of the same structure. On the disk, signatures of both
transverse and longitudinal intensity features were observed by AIA; both show
similar properties to signatures found along structures anchored in the same
active region three days earlier above the limb. Correlated features are
recovered by space-time analysis of neighbouring tracks over perpendicular
distances of <2.6Mm.


title:
Recurrence relations for patterns of type $(2,1)$ in flattened
  permutations

abstract:
  We consider the problem of counting the occurrences of patterns of the form
$xy-z$ within flattened permutations of a given length. Using symmetric
functions, we find recurrence relations satisfied by the distributions on
$\mathcal{S}_n$ for the patterns 12-3, 21-3, 23-1 and 32-1, and develop a
unified approach to obtain explicit formulas. By these recurrences, we are able
to determine simple closed form expressions for the number of permutations
that, when flattened, avoid one of these patterns as well as expressions for
the average number of occurrences. In particular, we find that the average
number of 23-1 patterns and the average number of 32-1 patterns in
$\text{Flatten}(\pi)$, taken over all permutations $\pi$ of the same length,
are equal, as are the number of permutations avoiding either of these patterns.
We also find that the average number of 21-3 patterns in $\text{Flatten}(\pi)$
over all $\pi$ is the same as it is for 31-2 patterns.


title: Microlocal Properties of Bisingular Operators

abstract:
  We study the microlocal properties of bisingular operators, a class of
operators on the product of two compact manifolds. We define a wave front set
for such operators, and analyse its properties. We compare our wave front set
with the $SG$ wave front set, a global wave front set which shares with it
formal similarities.


title: Modification of cosmic-ray energy spectra by stochastic acceleration

abstract:
  Context: Typical space plasmas contain spatially and temporally variable
turbulent electromagnetic fields. Understanding the transport of energetic
particles and the acceleration mechanisms for charged particles is an important
goal of today's astroparticle physics. Aims: To understand the acceleration
mechanisms at the particle source, subsequent effects have to be known.
Therefore, the modification of a particle energy distribution, due to
stochastic acceleration, needs to be investigated. Methods: The diffusion in
momentum space was investigated by using both a Monte-Carlo simulation code and
by analytically solving the momentum-diffusion equation. For simplicity, the
turbulence was assumed to consist of one-dimensional Alfven waves. Results:
Using both methods, it is shown that, on average, all particles with velocities
comparable to the Alfven speeds are accelerated. This influences the energy
distribution by significantly increasing the energy spectral index.
Conclusions: Because of electromagnetic turbulence, a particle energy spectrum
measured at Earth can drastically deviate from its initial spectrum. However,
for particles with velocities significantly above the Alfven speed, the effect
becomes negligible.


title:
Building galaxies, stars, planets and the ingredients for life between
  the stars. A scientific proposal for a European Ultraviolet-Visible
  Observatory (EUVO)

abstract:
  The growth of luminous structures and the building blocks of life in the
Universe began as primordial gas was processed in stars and mixed at galactic
scales. The mechanisms responsible for this development are not well understood
and have changed over the intervening 13 billion years. To follow the evolution
of matter over cosmic time, it is necessary to study the strongest (resonance)
transitions of the most abundant species in the Universe. Most of them are in
the ultraviolet (UV; 950A-3000A) spectral range that is unobservable from the
ground. A versatile space observatory with UV sensitivity a factor of 50-100
greater than existing facilities will revolutionize our understanding of the
Universe.
  Habitable planets grow in protostellar discs under ultraviolet irradiation, a
by-product of the star-disk interaction that drives the physical and chemical
evolution of discs and young planetary systems. The electronic transitions of
the most abundant molecules are pumped by the UV field, providing unique
diagnostics of the planet-forming environment that cannot be accessed from the
ground. Earth's atmosphere is in constant interaction with the interplanetary
medium and the solar UV radiation field. A 50-100 times improvement in
sensitivity would enable the observation of the key atmospheric ingredients of
Earth-like exoplanets (carbon, oxygen, ozone), provide crucial input for models
of biologically active worlds outside the solar system, and provide the
phenomenological baseline to understand the Earth atmosphere in context.
  In this white paper, we outline the key science that such a facility would
make possible and outline the instrumentation to be implemented.


title:
Making Mean-Variance Hedging Implementable in a Partially Observable
  Market

abstract:
  The mean-variance hedging (MVH) problem is studied in a partially observable
market where the drift processes can only be inferred through the observation
of asset or index processes. Although most of the literatures treat the MVH
problem by the duality method, here we study a system consisting of three BSDEs
derived by Mania and Tevzadze (2003) and Mania et.al.(2008) and try to provide
more explicit expressions directly implementable by practitioners. Under the
Bayesian and Kalman-Bucy frameworks, we find that a relevant BSDE yields a
semi-closed solution via a simple set of ODEs which allow a quick numerical
evaluation. This renders remaining problems equivalent to solving European
contingent claims under a new forward measure, and it is straightforward to
obtain a forward looking non-sequential Monte Carlo simulation scheme. We also
give a special example where the hedging position is available in a semi-closed
form. For more generic setups, we provide explicit expressions of approximate
hedging portfolio by an asymptotic expansion. These analytic expressions not
only allow the hedgers to update the hedging positions in real time but also
make a direct analysis of the terminal distribution of the hedged portfolio
feasible by standard Monte Carlo simulation.


title:
Enhanced sensing with quasi-degenerate mode in fiber Bragg gratings ring
  cavities

abstract:
  In this paper, we report the model and the experimental demonstration of a
new optical resonator formed by inserting a Fiber Bragg Grating (FBG) in a
closed fiber loop. The spectral characteristics of the ring depend on the
reflectivity of the FBG. When the FBG reflectivity tends to zero, the overall
resonant system exhibits the usual degenerate mode conditions. On the other
hand, when the reflection coefficient FBG is not vanishing, the spectral
features of the resonator display split resonant modes associated to the
degeneracy removal of two counterpropagating modes that resonate within the
cavity. The splitting magnitude is maximal in the region of maximum
reflectivity of the FBG. Moreover, it varies by acting on the FBG physical
parameters (e.g. strain, temperature, group index). By considering the spectral
region where the splitting magnitude variation is almost maximal, i.e. quasi
degenerate mode condition, we prove that the device can be used also as a slow
light sensor by monitoring the power change associated with the applied strain
showing, in this case, a sensitivity of 3.6x10^(6)x eps^(-1). To the best of
our knowledge, this represents a factor 20 improvement over the best slow-light
FBG sensors.


title: Forbidden Kaon and Pion Decays in NA62

abstract:
  NA62, an experiment at the CERN SPS to measure the branching ratio for the
decay K+ -> pi+ nu nu-bar with ~10% precision, will observe ~10^13 K+ decays in
its fiducial volume, and will thus also be able to carry out a rich program to
search for forbidden K+ and pi0 decays, including in particular K+ decays that
violate the conservation of lepton flavor and/or number. NA62's potential
performance in searches for a number of forbidden K+ and pi0 decays is
discussed, with initial sensitivity estimates.


title: Sharp generalizations of the multilinear Bohnenblust--Hille inequality

abstract:
  We prove that the multilinear Bohnenblust--Hille is a particular case of a
quite general family of optimal inequalities.


title: Calculation of the quantum discord in many-qubit systems

abstract:
  For the first time, we compute the quantum discord in bipartite systems
containing up to nine qubits. An analytical expression is obtained for the
discord in a bipartite system with three qubits. The dependence of the discord
on the temperature and the structural parameter of the model is studied.


title: Detection of the Ammonium Ion in Space

abstract:
  We report on the detection of a narrow feature at 262816.73 MHz towards Orion
and the cold prestellar core B1-bS, that we attribute to the 1(0)-0(0) line of
the deuterated Ammonium ion, NH3D+. The observations were performed with the
IRAM 30m radio telescope. The carrier has to be a light molecular species as it
is the only feature detected over 3.6 GHz of bandwidth. The hyperfine structure
is not resolved indicating a very low value for the electric quadrupolar
coupling constant of Nitrogen which is expected for NH3D+ as the electric field
over the N nucleus is practically zero. Moreover, the feature is right at the
predicted frequency for the 1(0)-0(0) transition of the Ammonium ion, 262817(6)
MHz (3sigma), using rotational constants derived from new infrared data
obtained in our laboratory in Madrid. The estimated column density is
1.1(0.2)e12 cm-2. Assuming a deuterium enhancement similar to that of NH2D, we
derive N(NH4+) sim 2.6e13 cm-2, i.e., an abundance for Ammonium of a few
1e(-11).


title: Efficient demagnetization cooling of atoms and its limits

abstract:
  Demagnetization cooling relies on spin-orbit coupling that brings motional
and spin degrees of freedom into thermal equilibrium. In the case of a gas, one
has the advantage that the spin degree of freedom can be cooled very
efficiently using optical pumping. We investigate demagnetization cooling of a
chromium gas in a deep optical dipole trap over a large temperature range and
reach high densities up to $5\times 10^{19} m^{-3}$. We study the loss
mechanism under such extreme conditions and identify excited-state collisions
as the main limiting process. We discuss that in some systems demagnetization
cooling has a realistic potential of reaching degeneracy by optical cooling
only.


title:
Ultra-Large-Scale Continuous-Variable Cluster States Multiplexed in the
  Time Domain

abstract:
  Quantum computers promise ultrafast performance of certain tasks.
Experimentally appealing, measurement-based quantum computation (MBQC) requires
an entangled resource called a cluster state, with long computations requiring
large cluster states. Previously, the largest cluster state consisted of 8
photonic qubits or light modes, while the largest multipartite entangled state
of any sort involved 14 trapped ions. These implementations involve quantum
entities separated in space, and in general, each experimental apparatus is
used only once. Here, we circumvent this inherent inefficiency by multiplexing
light modes in the time domain. We deterministically generate and fully
characterise a continuous-variable cluster state containing more than 10,000
entangled modes. This is, by 3 orders of magnitude, the largest entangled state
ever created to date. The entangled modes are individually addressable
wavepackets of light in two beams. Furthermore, we present an efficient scheme
for MBQC on this cluster state based on sequential applications of quantum
teleportation.


title:
Time-dependent relaxation of strained silicon-on-insulator lines using a
  partially coherent x-ray nanobeam

abstract:
  We report on the quantitative determination of the strain map in a strained
Silicon-On-Insulator (sSOI) line with a 200x70 nm^2 cross-section. In order to
study a single line as a function of time, we used an X-ray nanobeam with
relaxed coherence properties as a compromise between beam size, coherence and
intensity. We demonstrate how it is possible to reconstruct the line
deformation at the nanoscale, and follow its evolution as the line relaxes
under the influence of the X-ray nanobeam.


title: Experimental plug&play quantum coin flipping

abstract:
  Performing complex cryptographic tasks will be an essential element in future
quantum communication networks. These tasks are based on a handful of
fundamental primitives, such as coin flipping, where two distrustful parties
wish to agree on a randomly generated bit. Although it is known that quantum
versions of these primitives can offer information-theoretic security
advantages with respect to classical protocols, a demonstration of such an
advantage in a practical communication scenario has remained elusive. Here, we
experimentally implement a quantum coin flipping protocol that performs
strictly better than classically possible over a distance suitable for
communication over metropolitan area optical networks. The implementation is
based on a practical plug&play system, designed for quantum key distribution.
We also show how to combine our protocol with coin flipping protocols that are
almost perfectly secure against bounded adversaries, hence enhancing them with
a level of information-theoretic security. Our results offer a powerful toolbox
for future secure quantum communications.


title: Gluon saturation scale from the KGBJS equation

abstract:
  The CCFM equation and its extended form with a quadratic term (KGBJS
equation) are solved with fixed and running coupling constant. The solution of
the KGBJS equation is compared to gluon densities resulting from the CCFM and
BK equations. As the saturation scale $Q_s$ now becomes available as a function
of the hard scale $p$ we observe that low values of $p$ impede its growth with
$\frac 1 x$. Also, at values much larger than partons transversal momentum the
saturation effects become independent on the hard scale what we call liberation
of saturation scale. We also introduce the hard-scale-related saturation scale
$P_s$ and investigate its energy dependence. We observe that the new scale as a
function of $x$ decreases starting from the value of transversal momentum of
gluon.


title: Observation of Entanglement-Dependent Two-Particle Holonomic Phase

abstract:
  Holonomic phases---geometric and topological---have long been an intriguing
aspect of physics. They are ubiquitous, ranging from observations in particle
physics to applications in fault tolerant quantum computing. However, their
exploration in particles sharing genuine quantum correlations lack in
observations. Here we experimentally demonstrate the holonomic phase of two
entangled-photons evolving locally, which nevertheless gives rise to an
entanglement-dependent phase. We observe its transition from geometric to
topological as the entanglement between the particles is tuned from zero to
maximal, and find this phase to behave more resilient to evolution changes with
increasing entanglement. Furthermore, we theoretically show that holonomic
phases can directly quantify the amount of quantum correlations between the two
particles. Our results open up a new avenue for observations of holonomic
phenomena in multi-particle entangled quantum systems.


title:
Adaptation and learning of molecular networks as a description of cancer
  development at the systems-level: Potential use in anti-cancer therapies

abstract:
  There is a widening recognition that cancer cells are products of complex
developmental processes. Carcinogenesis and metastasis formation are
increasingly described as systems-level, network phenomena. Here we propose
that malignant transformation is a two-phase process, where an initial increase
of system plasticity is followed by a decrease of plasticity at late stages of
carcinogenesis as a model of cellular learning. We describe the hallmarks of
increased system plasticity of early, tumor initiating cells, such as increased
noise, entropy, conformational and phenotypic plasticity, physical
deformability, cell heterogeneity and network rearrangements. Finally, we argue
that the large structural changes of molecular networks during cancer
development necessitate a rather different targeting strategy in early and late
phase of carcinogenesis. Plastic networks of early phase cancer development
need a central hit, while rigid networks of late stage primary tumors or
established metastases should be attacked by the network influence strategy,
such as by edgetic, multi-target, or allo-network drugs. Cancer stem cells need
special diagnosis and targeting, since their dormant and rapidly proliferating
forms may have more rigid, or more plastic networks, respectively. The
extremely high ability to change their rigidity/plasticity may be a key
differentiating hallmark of cancer stem cells. The application of early
stage-optimized anti-cancer drugs to late-stage patients may be a reason of
many failures in anti-cancer therapies. Our hypotheses presented here underlie
the need for patient-specific multi-target therapies applying the correct ratio
of central hits and network influences -- in an optimized sequence.


title:
Hydrodynamics of the Kuramoto-Vicsek model of rotating self-propelled
  particles

abstract:
  We consider an Individual-Based Model for self-rotating particles interacting
through local alignment and investigate its macroscopic limit. This model
describes self-propelled particles moving in the plane and trying to
synchronize their rotation motion with their neighbors. It combines the
Kuramoto model of synchronization and the Vicsek model of swarm formation. We
study the mean-field kinetic and hydrodynamic limits of this system within two
different scalings. In the small angular velocity regime, the resulting model
is a slight modification of the 'Self-Organized Hydrodynamic' model which has
been previously introduced by the first author. In the large angular velocity
case, a new type of hydrodynamic model is obtained. A preliminary study of the
linearized stability is proposed.


title:
A robust algorithm for template curve estimation based on manifold
  embedding

abstract:
  This paper considers the problem of finding a meaningful template function
that represents the common pattern of a sample of curves. To address this
issue, a novel algorithm based on a robust version of the isometric featuring
mapping (Isomap) algorithm is developed. Assuming that the functional data lie
on an intrinsically low-dimensional smooth manifold with unknown underlying
structure, we propose an approximation of the geodesic distance. This
approximation is used to compute the corresponding empirical Fr\'echet median
function, which provides an intrinsic estimator of the template function.
Unlike the Isomap method, the algorithm has the advantage of being parameter
free and easier to use. Comparisons with other methods, with both simulated and
real datasets, show that the algorithm works well and outperforms these
methods.


title:
Global bifurcations to subcritical magnetorotational dynamo action in
  Keplerian shear flow

abstract:
  Magnetorotational dynamo action in Keplerian shear flow is a
three-dimensional, nonlinear magnetohydrodynamic process whose study is
relevant to the understanding of accretion and magnetic field generation in
astrophysics. Transition to this form of dynamo is subcritical and shares many
characteristics of transition to turbulence in non-rotating hydrodynamic shear
flows. This suggests that these different fluid systems become active through
similar generic bifurcation mechanisms, which in both cases have eluded
detailed understanding so far. In this paper, we investigate numerically the
bifurcation mechanisms at work in the incompressible Keplerian
magnetorotational dynamo problem in the shearing box framework. Using numerical
techniques imported from dynamical systems research, we show that the onset of
chaotic dynamo action at magnetic Prandtl numbers larger than unity is
primarily associated with global homoclinic and heteroclinic bifurcations of
nonlinear magnetorotational dynamo cycles. These global bifurcations are
supplemented by local bifurcations of cycles marking the beginning of
period-doubling cascades. This suggests that nonlinear magnetorotational dynamo
cycles provide the pathway to turbulent injection of both kinetic and magnetic
energy in incompressible magnetohydrodynamic Keplerian shear flow in the
absence of an externally imposed magnetic field. Studying the nonlinear physics
and bifurcations of these cycles in different regimes and configurations may
subsequently help to better understand the conditions of excitation of
magnetohydrodynamic turbulence and instability-driven dynamos in various
astrophysical systems and laboratory experiments. The detailed characterization
of global bifurcations provided for this three-dimensional subcritical fluid
dynamics problem may also prove useful for the problem of transition to
turbulence in hydrodynamic shear flows.

categories: astro-ph.HE astro-ph.GA astro-ph.SR nlin.CD physics.flu-dyn


title: The essence of component-based design and coordination

abstract:
  Is there a characteristic of coordination languages that makes them
qualitatively different from general programming languages and deserves special
academic attention? This report proposes a nuanced answer in three parts. The
first part highlights that coordination languages are the means by which
composite software applications can be specified using components that are only
available separately, or later in time, via standard interfacing mechanisms.
The second part highlights that most currently used languages provide
mechanisms to use externally provided components, and thus exhibit some
elements of coordination. However not all do, and the availability of an
external interface thus forms an objective and qualitative criterion that
distinguishes coordination. The third part argues that despite the qualitative
difference, the segregation of academic attention away from general language
design and implementation has non-obvious cost trade-offs.


title: The Cauchy problem for D-modules on Ran spaces

abstract:
  We will adopt an elementary approach to D-modules on Ran spaces in terms of
two-limits; the aim here is to define the category of coherent D-modules,
characteristic varieties and non-characteristic maps. An application will be
the proof of the Cauchy-Kowaleski-Kashiwara theorem in this setting.


title:
Suppression of quantum-mechanical reflection by environmental
  decoherence

abstract:
  In quantum mechanics an incoming particle wave packet with sufficient energy
will undergo both transmission and reflection when encountering a barrier of
lower energy, but in classical mechanics there is no reflection, only
transmission. In this paper we seek to explain the disappearance of
quantum-mechanical reflection in the quasi-classical limit, using standard
methods of decoherence through environmental interaction. We consider two
models. In the first, the incoming particle is classicalized by coupling it to
an environment described by a standard Lindblad master equation diagonalizing
in position. We find, however, that suppression of reflection is achieved only
for environmental interaction so strong that large fluctuations in momentum are
generated which blurs the distinction between incoming and reflected wave
packets. This negative conclusion also holds for a complex potential which has
similar implications for attempts to understand the suppression of the Zeno
effect using the same mechanism (discussed in more detail in another paper). A
different Lindblad master diagonalizing in momentum is shown to be successful
in suppressing reflection without large fluctuations but such a master equation
is unphysical. We consider a second model in which the barrier is modelled
quantum-mechanically by a massive target particle coupled to an environment to
maintain it in a quasi-classical state. This avoids the fluctuations problem
since the incoming particle is not coupled to the environment directly. We find
that reflection is significantly suppressed as long as the decoherence
timescale of the target particle is much smaller than certain characteristic
scattering timescales of the incoming particle, or equivalently, as long as the
velocity fluctuations in the target are larger than the velocity of the
incoming particle.


title:
Approximate Consensus Multi-Agent Control Under Stochastic Environment
  with Application to Load Balancing

abstract:
  The paper is devoted to the approximate consensus problem for networks of
nonlinear agents with switching topology, noisy and delayed measurements. In
contrast to the existing stochastic approximation-based control algorithms
(protocols), a local voting protocol with nonvanishing step size is proposed.
Nonvanishing (e.g., constant) step size protocols give the opportunity to
achieve better convergence rate (by choosing proper step sizes) in coping with
time-varying loads and agent states. The price to pay is replacement of the
mean square convergence with an approximate one. To analyze dynamics of the
closed loop system, the so-called method of averaged models is used. It allows
to reduce analysis complexity of the closed loop system. In this paper the
upper bounds for mean square distance between the initial system and its
approximate averaged model are proposed. The proposed upper bounds are used to
obtain conditions for approximate consensus achievement.
  The method is applied to the load balancing problem in stochastic dynamic
networks with incomplete information about the current states of agents and
with changing set of communication links. The load balancing problem is
formulated as consensus problem in noisy model with switched topology. The
conditions to achieve the optimal level of load balancing (in the sense that if
no new task arrives, all agents will finish at the same time) are obtained.
  The performance of the system is evaluated analytically and by simulation. It
is shown that the performance of the adaptive multi-agent strategy with the
redistribution of tasks among "connected" neighbors is significantly better
than the performance without redistribution. The obtained results are important
for control of production networks, multiprocessor, sensor or multicomputer
networks, etc.


title:
Prototypes of higher algebroids with applications to variational
  calculus

abstract:
  Reductions of higher tangent bundles of Lie groupoids provide natural
examples of geometric structures which we would like to call higher algebroids.
Such objects can be also constructed abstractly starting from an arbitrary
almost Lie algebroid. A higher algebroid is, in principle, a graded bundle
equipped with a differential relation of special kind (a Zakrzewski morphism).
In the paper we investigate basic properties of higher algebroids and show some
applications. Namely, we develop a geometric framework for variational calculus
on higher algebroids (including both forces and momenta). Such a formalism
covers simultaneously variational problems on higher tangent bundles,
first-order problems on algebroids and higher-order problems reduced by
symmetries.


title: Constraints on Electroweak Effective Operators at One Loop

abstract:
  We derive bounds on nine dimension-six operators involving electroweak gauge
bosons and the Higgs boson from precision electroweak data. Four of these
operators contribute at tree level, and five contribute only at one loop. Using
the full power of effective field theory, we show that the bounds on the five
loop-level operators are much weaker than previously claimed, and thus much
weaker than bounds from tree-level processes at high-energy colliders.


title: Chern-Simons Theory on Seifert 3-Manifolds

abstract:
  We study Chern-Simons theory on 3-manifolds M that are circle-bundles over
2-dimensional orbifolds S by the method of Abelianisation. This method, which
completely sidesteps the issue of having to integrate over the moduli space of
non-Abelian flat connections, reduces the complete partition function of the
non-Abelian theory on M to a 2-dimensional Abelian theory on the orbifold S
which is easily evaluated.


title:
Spinful fermionic ladders at incommensurate filling: Phase diagram,
  local perturbations, and ionic potentials

abstract:
  We study the effect of external potential on transport properties of the
fermionic two-leg ladder model. The response of the system to a local
perturbation is strongly dependent on the ground state properties of the system
and especially on the dominant correlations. We categorise all phases and
transitions in the model (for incommensurate filling) and introduce
"hopping-driven transitions" that the system undergoes as the inter-chain
hopping is increased from zero. We also describe the response of the system to
an ionic potential. The physics of this effect is similar to that of the single
impurity, except that the ionic potential can affect the bulk properties of the
system and in particular induce true long range order.


title:
Autonomous Demand Side Management Based on Energy Consumption Scheduling
  and Instantaneous Load Billing: An Aggregative Game Approach

abstract:
  In this paper, we investigate a practical demand side management scenario
where the selfish consumers compete to minimize their individual energy cost
through scheduling their future energy consumption profiles. We propose an
instantaneous load billing scheme to effectively convince the consumers to
shift their peak-time consumption and to fairly charge the consumers for their
energy consumption. For the considered DSM scenario, an aggregative game is
first formulated to model the strategic behaviors of the selfish consumers. By
resorting to the variational inequality theory, we analyze the conditions for
the existence and uniqueness of the Nash equilibrium (NE) of the formulated
game. Subsequently, for the scenario where there is a central unit calculating
and sending the real-time aggregated load to all consumers, we develop a one
timescale distributed iterative proximal-point algorithm with provable
convergence to achieve the NE of the formulated game. Finally, considering the
alternative situation where the central unit does not exist, but the consumers
are connected and they would like to share their estimated information with
others, we present a distributed agreement-based algorithm, by which the
consumers can achieve the NE of the formulated game through exchanging
information with their immediate neighbors.


title:
Stable hydrogenated graphene edge types: Normal and reconstructed Klein
  edges

abstract:
  Hydrogenated graphene edges are assumed to be either armchair, zigzag or a
combination of the two. We show that the zigzag is not the most stable fully
hydrogenated structure along the <2-1-10> direction. Instead hydrogenated Klein
and reconstructed Klein based edges are found to be energetically more
favourable, with stabilities approaching that of armchair edges. These new
structures "unify" graphene edge topology, the most stable flat hydrogenated
graphene edges always consisting of pairwise bonded C2H4 edge groups,
irrespective the edge orientation. When edge rippling is included, CH3 edge
groups are most stable. These new fundamental hydrogen terminated edges have
important implications for graphene edge imaging and spectroscopy, as well as
mechanisms for graphene growth, nanotube cutting, and nanoribbon formation and
behaviour.


title:
Extensions for Finite Chevalley Groups III: Rational and Generic
  Cohomology

abstract:
  Let $G$ be a connected reductive algebraic group and $B$ be a Borel subgroup
defined over an algebraically closed field of characteristic $p>0$. In this
paper, the authors study the existence of generic $G$-cohomology and its
stability with rational $G$-cohomology groups via the use of methods from the
authors' earlier work. New results on the vanishing of $G$ and $B$-cohomology
groups are presented. Furthermore, vanishing ranges for the associated finite
group cohomology of $G({\mathbb F}_{q})$ are established which generalizes
earlier work of Hiller, in addition to stability ranges for generic cohomology
which improves on seminal work of Cline, Parshall, Scott and van der Kallen.


title:
Fully Convective Magnetorotational Turbulence in Stratified Shearing
  Boxes

abstract:
  We present a numerical study of turbulence and dynamo action in stratified
shearing boxes with zero magnetic flux. We assume that the fluid obeys the
perfect gas law and has finite (constant) thermal diffusivity. We choose
radiative boundary conditions at the vertical boundaries in which the heat flux
is propor- tional to the fourth power of the temperature. We compare the
results with the corresponding cases in which fixed temperature boundary
conditions are applied. The most notable result is that the formation of a
fully convective state in which the density is nearly constant as a function of
height and the heat is transported to the upper and lower boundaries by
overturning motions is robust and persists even in cases with radiative
boundary conditions. Interestingly, in the convective regime, although the
diffusive transport is negligible the mean stratification does not relax to an
adiabatic state.


title:
Measuring the Cooling of the Neutron Star in Cassiopeia A with all
  Chandra X-ray Observatory Detectors

abstract:
  The thermal evolution of young neutron stars (NSs) reflects the neutrino
emission properties of their cores. Heinke et al. (2010) measured a 3.6+/-0.6%
decay in the surface temperature of the Cassiopeia A (Cas A) NS between 2000
and 2009, using archival data from the Chandra X-ray Observatory ACIS-S
detector in Graded mode. Page et al. (2011) and Shternin et al. (2011)
attributed this decay to enhanced neutrino emission from a superfluid neutron
transition in the core. Here we test this decline, combining analysis of the
Cas A NS using all Chandra X-ray detectors and modes (HRC-S, HRC-I, ACIS-I,
ACIS-S in Faint mode, and ACIS-S in Graded mode) and adding a 2012 May ACIS-S
Graded mode observation, using the most current calibrations (CALDB 4.5.5.1).
We measure the temperature changes from each detector separately and test for
systematic effects due to the nearby filaments of the supernova remnant. We
find a 0.92%-2.0% decay over 10 years in the effective temperature, inferred
from HRC-S data, depending on the choice of source and background extraction
regions, with a best-fit decay of 1.0+/-0.7%. In comparison, the ACIS-S Graded
data indicate a temperature decay of 3.1%-5.0% over 10 years, with a best-fit
decay of 3.5+/-0.4%. Shallower observations using the other detectors yield
temperature decays of 2.6+/-1.9% (ACIS-I), 2.1+/-1.0% (HRC-I), and 2.1+/-1.9%
(ACIS-S Faint mode) over 10 years. Our best estimate indicates a decline of
2.9+/-0.9 (stat) +1.6/-0.3 (sys) % over 10 years. The complexity of the bright
and varying supernova remnant background makes a definitive interpretation of
archival Cas A Chandra observations difficult. A temperature decline of 1-3.5%
over 10 years would indicate extraordinarily fast cooling of the NS that can be
regulated by superfluidity of nucleons in the stellar core.


title: Quantum no-key protocol for secure communication of classical message

abstract:
  We propose a class of quantum no-key protocols for private communication of
classical message based on quantum computing of random Boolean permutations,
and demonstrate that they are information-theoretic secure. These protocols are
designed to resist middleman attack for two parties preshared authentication
key, and achieve perfect mutual data origin authentication which ensures the
permanent reusing of authentication key. Finally, we simplify the protocol to a
4-round one, and show that any protocol with 3 or less rounds cannot achieve
perfect security without consuming preshared key.


title: An inequality for adjoint rational surfaces

abstract:
  We generalize an inequality for convex lattice polygons -- aka toric surfaces
-- to general rational surfaces.


title: Degeneracy loci and polynomial equation solving

abstract:
  Let V be a smooth equidimensional quasi-affine variety of dimension r over
the complex numbers $C$ and let $F$ be a $(p\times s)$-matrix of coordinate
functions of $C[V]$, where $s\ge p+r$. The pair $(V,F)$ determines a vector
bundle $E$ of rank $s-p$ over $W:=\{x\in V:\mathrm{rk} F(x)=p\}$. We associate
with $(V,F)$ a descending chain of degeneracy loci of E (the generic polar
varieties of $V$ represent a typical example of this situation).
  The maximal degree of these degeneracy loci constitutes the essential
ingredient for the uniform, bounded error probabilistic pseudo-polynomial time
algorithm which we are going to design and which solves a series of
computational elimination problems that can be formulated in this framework. We
describe applications to polynomial equation solving over the reals and to the
computation of a generic fiber of a dominant endomorphism of an affine space.


title:
Local Convergence of an Algorithm for Subspace Identification from
  Partial Data

abstract:
  GROUSE (Grassmannian Rank-One Update Subspace Estimation) is an iterative
algorithm for identifying a linear subspace of R^n from data consisting of
partial observations of random vectors from that subspace. This paper examines
local convergence properties of GROUSE, under assumptions on the randomness of
the observed vectors, the randomness of the subset of elements observed at each
iteration, and incoherence of the subspace with the coordinate directions.
Convergence at an expected linear rate is demonstrated under certain
assumptions. The case in which the full random vector is revealed at each
iteration allows for much simpler analysis, and is also described. GROUSE is
related to incremental SVD methods and to gradient projection algorithms in
optimization.


title:
Unsupervised deconvolution of dynamic imaging reveals intratumor
  vascular heterogeneity

abstract:
  Intratumor heterogeneity is often manifested by vascular compartments with
distinct pharmacokinetics that cannot be resolved directly by in vivo dynamic
imaging. We developed tissue-specific compartment modeling (TSCM), an
unsupervised computational method of deconvolving dynamic imaging series from
heterogeneous tumors that can improve vascular phenotyping in many biological
contexts. Applying TSCM to dynamic contrast-enhanced MRI of breast cancers
revealed characteristic intratumor vascular heterogeneity and therapeutic
responses that were otherwise undetectable.


title:
Evidence of quiet Sun chromospheric activity related to an emerging
  small-scale magnetic loop

abstract:
  Aims: We investigate the temporal evolution of magnetic flux emergence in the
quiet Sun atmosphere close to disk center. Methods: We combine high-resolution
SoHO/MDI magnetograms with TRACE observations taken in the 1216 {\AA} channel
in order to analyze the temporal evolution of an emerging small-scale magnetic
loop and its traces in the chromosphere. Results: At first place, we find
signatures of flux emergence very close to the edge of a supergranular network
boundary located at disk center. The new emerging flux appears first in the MDI
magnetograms in form of an asymmetric bipolar element, i.e. the patch with
negative polarity is roughly two-times weaker than the corresponding patch with
opposite polarity. The average values of magnetic flux and magnetic flux
densities reach 1.6 x 10^18 Mx, -8.5 x 10^17 Mx, and 55 Mx cm^-2, -30 Mx cm^-2,
respectively. The spatial distance between the opposite polarity patches of the
emerged feature increases from about 2.5" to 5.0" during the lifetime of the
loop which was not longer than 36 min. A more precise lifetime-estimate of the
feature was not possible because of a gap in the temporal sequence of the MDI
magnetograms. The chromospheric response to the emerged magnetic dipole occurs
~ 9 minutes later with respect to the photospheric magnetograms. It consists of
a quasi-periodic sequence of time-localized brightenings visible in the 1216
{\AA} TRACE channel apparent for ~ 14 minutes and being co-spatial with the
axis connecting the two patches of opposite magnetic polarity. Conclusions: We
identify the observed event as a small-scale magnetic loop emerging at
photospheric layers and subsequently rising up to the chromosphere. We discuss
the possibility that the fluctuations detected in the chromospheric emission
probably reflect magnetic field oscillations which propagate to the
chromosphere in form of waves.


title: Light-controlled perfect absorption of light

abstract:
  We study coherent perfect absorption (CPA) of light in a Kerr nonlinear
metal-dielectric composite medium, illuminated from the opposite ends.
Elementary symmetry considerations reveal that equality of the incident light
intensities is a prerequisite to ensure CPA in both linear and nonlinear
systems for specific system parameters. We also derive the sufficient
conditions for having CPA. We further show that while CPA in a linear system is
insensitive to the incident power level, that in a nonlinear system can be
achieved only for discrete intensities with interesting hysteretic response.
Our unified formulation of CPA and waveguiding identifies them as opposite
scattering phenomena. We further investigate light-induced CPA in on- and off-
resonant systems.


title: Evolutionary Model of a Anonymous Consumer Durable Market

abstract:
  An analytic model is presented that considers the evolution of a market of
durable goods. The model suggests that after introduction goods spread always
according to a Bass diffusion. However, this phase will be followed by a
diffusion process for durable consumer goods governed by a
variation-selection-reproduction mechanism and the growth dynamics can be
described by a replicator equation. Describing the aggregate sales as the sum
of first, multiple and replacement purchase the product life cycle can be
derived. Replacement purchase causes periodic variations of the sales
determined by the finite lifetime of the good (Juglar cycles). The model
suggests that both, Bass- and Gompertz diffusion may contribute to the product
life cycle of a consumer durable. The theory contains the standard equilibrium
view of a market as a special case. It depends on the time scale, whether an
equilibrium or evolutionary description is more appropriate. The evolutionary
framework is used to derive also the size, growth rate and price distribution
of manufacturing business units. It predicts that the size distribution of the
business units (products) is lognormal, while the growth rates exhibit a
Laplace distribution. Large price deviations from the mean price are also
governed by a Laplace distribution (fat tails). These results are in agreement
with empirical findings. The explicit comparison of the time evolution of
consumer durables with empirical investigations confirms the close relationship
between price decline and Gompertz diffusion, while the product life cycle can
be described qualitatively for a long time period.


title:
Symmetry minimizes the principal eigenvalue: an example for the Pucci's
  sup operator

abstract:
  We explicitly evaluate the principal eigenvalue of the extremal Pucci's
sup--operator for a class of special plane domains, and we prove that, for
fixed area, the eigenvalue is minimal for the most symmetric set.


title:
Asymptotic formula for the tail of the maximum of smooth Stationary
  Gaussian fields on non locally convex sets

abstract:
  In this paper we consider the distribution of the maximum of a Gaussian field
defined on non locally convex sets. Adler and Taylor or Aza\"\i s and Wschebor
give the expansions in the locally convex case. The present paper generalizes
their results to the non locally convex case by giving a full expansion in
dimension 2 and some generalizations in higher dimension. For a given class of
sets, a Steiner formula is established and the correspondence between this
formula and the tail of the maximum is proved. The main tool is a recent result
of Aza\"\i s and Wschebor that shows that under some conditions the excursion
set is close to a ball with a random radius. Examples are given in dimension 2
and higher.


title: Significant Scales in Community Structure

abstract:
  Many complex networks show signs of modular structure, uncovered by community
detection. Although many methods succeed in revealing various partitions, it
remains difficult to detect at what scale some partition is significant. This
problem shows foremost in multi-resolution methods. We here introduce an
efficient method for scanning for resolutions in one such method. Additionally,
we introduce the notion of "significance" of a partition, based on subgraph
probabilities. Significance is independent of the exact method used, so could
also be applied in other methods, and can be interpreted as the gain in
encoding a graph by making use of a partition. Using significance, we can
determine "good" resolution parameters, which we demonstrate on benchmark
networks. Moreover, optimizing significance itself also shows excellent
performance. We demonstrate our method on voting data from the European
Parliament. Our analysis suggests the European Parliament has become
increasingly ideologically divided and that nationality plays no role.


title: Spin-phonon induced magnetic order in Kagome ice

abstract:
  We study the effects of lattice deformations on the Kagome spin ice, with
Ising spins coupled by nearest neighbor exchange and long range dipolar
interactions, in the presence of in-plane magnetic fields. We describe the
lattice energy according to the Einstein model, where each site distortion is
treated independently. Upon integration of lattice degrees of freedom,
effective quadratic spin interactions arise. Classical MonteCarlo simulations
are performed on the resulting model, retaining up to third neighbor
interactions, under different directions of the magnetic field. We find that,
as the effect of the deformation is increased, a rich plateau structure appears
in the magnetization curves.


title: Persistent random walk with exclusion

abstract:
  Modelling the propagation of a pulse in a dense {\em milieu} poses
fundamental challenges at the theoretical and applied levels. To this aim, in
this paper we generalize the telegraph equation to non-ideal conditions by
extending the concept of persistent random walk to account for spatial
exclusion effects. This is achieved by introducing an explicit constraint in
the hopping rates, that weights the occupancy of the target sites. We derive
the mean-field equations, which display nonlinear terms that are important at
high density. We compute the evolution of the mean square displacement (MSD)
for pulses belonging to a specific class of spatially symmetric initial
conditions. The MSD still displays a transition from ballistic to diffusive
behaviour. We derive an analytical formula for the effective velocity of the
ballistic stage, which is shown to depend in a nontrivial fashion upon both the
density (area) and the shape of the initial pulse. After a density-dependent
crossover time, nonlinear terms become negligible and normal diffusive
behaviour is recovered at long times.


title: Spectral analysis and slow spreading dynamics on complex networks

abstract:
  The Susceptible-Infected-Susceptible (SIS) model is one of the simplest
memoryless system for describing information/epidemic spreading phenomena with
competing creation and spontaneous annihilation reactions. The effect of
quenched disorder on the dynamical behavior has recently been compared to
quenched mean-field (QMF) approximations in scale-free networks. QMF can take
into account topological heterogeneity and clustering effects of the activity
in the steady state by spectral decomposition analysis of the adjacency matrix.
Therefore, it can provide predictions on possible rare-region effects, thus on
the occurrence of slow dynamics. I compare QMF results of SIS with simulations
on various large dimensional graphs. In particular, I show that for Erd\H
os-R\'enyi graphs this method predicts correctly the epidemic threshold and the
rare-region effects. Griffiths Phases emerge if the graph is fragmented or if
we apply strong, exponentially suppressing weighting scheme on the edges. The
latter model describes the connection time distributions in the face-to-face
experiments. In case of generalized Barab\'asi-Albert type of networks with
aging connections strong rare-region effects and numerical evidence for
Griffiths Phase dynamics are shown.

categories: physics.soc-ph cond-mat.dis-nn cond-mat.stat-mech q-bio.PE


title:
Localized modes in dense repulsive and attractive Bose-Einstein
  condensates with spin-orbit and Rabi couplings

abstract:
  We consider a binary Bose-Einstein condensate with linear and nonlinear
interactions between its components, which emulate the spinor system with
spin-orbit (SO) and Rabi couplings. For a relatively dense condensate, 1D
coupled equations with the nonpolynomial nonlinearity of both repulsive and
attractive signs are derived from the 3D Gross-Pitaevskii equations. Profiles
of modes confined in an external potential under the action of the
self-repulsion, and self-trapped solitons in the case of the self-attraction,
are found in a numerical form and by means of analytical approximations. In the
former case, the interplay of the SO and Rabi couplings with the repulsive
nonlinearity strongly distorts shapes of the trapped modes, adding conspicuous
side lobes to them. In the case of the attractive nonlinearity, the most
essential result is reduction of the collapse threshold under the action of the
SO and Rabi couplings.


title:
Limit sets for modules over groups on CAT(0) spaces -- from the
  Euclidean to the hyperbolic

abstract:
  The observation that the 0-dimensional Geometric Invariant $\Sigma ^{0}(G;A)$
of Bieri-Neumann-Strebel-Renz can be interpreted as a horospherical limit set
opens a direct trail from Poincar\'e's limit set $\Lambda (\Gamma)$ of a
discrete group $\Gamma $ of M\"obius transformations (which contains the
horospherical limit set of $\Gamma $) to the roots of tropical geometry
(closely related to $\Sigma ^{0}(G;A)$ when G is abelian). We explore this
trail by introducing the horospherical limit set, $\Sigma (M;A)$, of a G-module
A when G acts by isometries on a proper CAT(0) metric space M. This is a subset
of the boundary at infinity of M. On the way we meet instances where $\Sigma
(M;A)$ is the set of all conical limit points, the complement of a spherical
building, the complement of the radial projection of a tropical variety, or
(via the Bieri-Neumann-Strebel invariant) where it is closely related to the
Thurston norm.


title:
The origin of blue-shifted absorption features in the X-ray spectrum of
  PG 1211+143: Outflow or disc?

abstract:
  In some radio-quiet active galaxies (AGN), high-energy absorption features in
the x-ray spectra have been interpreted as Ultrafast Outflows (UFOs) -- highly
ionised material (e.g. Fe XXV and Fe XXVI) ejected at mildly relativistic
velocities. In some cases, these outflows can carry energy in excess of the
binding energy of the host galaxy. Needless to say, these features demand our
attention as they are strong signatures of AGN feedback and will influence
galaxy evolution. For the same reason, alternative models need to be discussed
and refuted or confirmed. Gallo & Fabian proposed that some of these features
could arise from resonance absorption of the reflected spectrum in a layer of
ionised material located above and corotating with the accretion disc.
Therefore, the absorbing medium would be subjected to similar blurring effects
as seen in the disc. A priori, the existence of such plasma above the disc is
as plausible as a fast wind. In this work, we highlight the ambiguity by
demonstrating that the absorption model can describe the ~7.6 keV absorption
feature (and possibly other features) in the quasar PG 1211+143, an AGN that is
often described as a classic example of an UFO. In this model, the 2-10 keV
spectrum would be largely reflection dominated (as opposed to power law
dominated in the wind models) and the resonance absorption would be originating
in a layer between about 6 and 60 gravitational radii. The studies of such
features constitutes a cornerstone for future X-ray observatories like Astro-H
and Athena+. Should our model prove correct, or at least important in some
cases, then absorption will provide another diagnostic tool with which to probe
the inner accretion flow with future missions.


title: Observation of surface states with algebraic localization

abstract:
  We introduce and experimentally demonstrate a class of surface bound states
with algebraic decay in a one-dimensional tight-binding lattice. Such states
have an energy embedded in the spectrum of scattered states and are
structurally stable against perturbations of lattice parameters. Experimental
demonstration of surface states with algebraic localization is presented in an
array of evanescently-coupled optical waveguides with tailored coupling rates.


title: Loss of anisotropy in strained ultrathin epitaxial L10 Mn-Ga films

abstract:
  In this work we are investigating the effect of strain in ultrathin Mn-Ga
thin films on the magnetic properties at room temperature. Two different Mn-Ga
compositions of which one is furthermore doped with Co were grown on Cr
buffered MgO (001) substrates. Films with a thickness below 12nm are highly
strained and it was observed that the ratio c/a vs. thickness is depending on
composition. Using c/a as an order parameter the PMA is shown to be drastically
reduced with increasing strain. These findings should be considered when
generalizing and downscaling results obtained from films >20nm. Furthermore it
has been shown, that the strain can be reduced by introducing an additional Pt
buffer and thus maintaining a high PMA for a thickness as low as 6nm.


title: Self-dual supersymmetric nonlinear sigma models

abstract:
  In four-dimensional N=1 Minkowski superspace, general nonlinear sigma models
with four-dimensional target spaces may be realised in term of CCL (chiral and
complex linear) dynamical variables which consist of a chiral scalar, a complex
linear scalar and their conjugate superfields. Here we introduce CCL sigma
models that are invariant under U(1) "duality rotations" exchanging the
dynamical variables and their equations of motion. The Lagrangians of such
sigma models prove to obey a partial differential equation that is analogous to
the self-duality equation obeyed by U(1) duality invariant models for nonlinear
electrodynamics. These sigma models are self-dual under a Legendre
transformation that simultaneously dualises (i) the chiral multiplet into a
complex linear one; and (ii) the complex linear multiplet into a chiral one.
Any CCL sigma model possesses a dual formulation given in terms of two chiral
multiplets. The U(1) duality invariance of the CCL sigma model proves to be
equivalent, in the dual chiral formulation, to a manifest U(1) invariance
rotating the two chiral scalars. Since the target space has a holomorphic
Killing vector, the sigma model possesses a third formulation realised in terms
of a chiral multiplet and a tensor multiplet.
  The family of U(1) duality invariant CCL sigma models includes a subset of
N=2 supersymmetric theories. Their target spaces are hyper Kahler manifolds
with a non-zero Killing vector field. In the case that the Killing vector field
is triholomorphic, the sigma model admits a dual formulation in terms of a
self-interacting off-shell N=2 tensor multiplet.
  We also identify a subset of CCL sigma models which are in a one-to-one
correspondence with the U(1) duality invariant models for nonlinear
electrodynamics. The target space isometry group for these sigma models
contains a subgroup U(1) x U(1).


title:
Investigation of the transfer and dissipation of energy in isotropic
  turbulence

abstract:
  A parallel pseudospectral code for the direct numerical simulation (DNS) of
isotropic turbulence has been developed. The code has been extensively
benchmarked using established results from literature.
  The code has been used to conduct a series of runs for freely-decaying
turbulence. We explore the use of power-law decay of the total energy to
determine an evolved time and compare with the use of dynamic quantities such
as the peak dissipation rate, maximum transport power and velocity derivative
skewness.
  Stationary turbulence has also been investigated, where we ensure that the
energy input rate remains constant for all runs. We present results for
Reynolds numbers up to R{\lambda} = 335 on a 1024^3 lattice. An exploitation of
the pseudospectral technique is used to calculate second and third-order
structure functions from the energy and transfer spectra, with a comparison
presented to the real-space calculation. An alternative to ESS is discussed,
with the second-order exponent found to approach 2/3.
  The dissipation anomaly is considered for forced and free-decay. The
K\'arm\'an-Howarth equation (KHE) is studied and a derivation of a new work
term presented. The balance of energy represented by the KHE is then
investigated. Based on the KHE, we develop a model for the behaviour of the
dimensionless dissipation coefficient that predicts C{\epsilon} =
C{\epsilon}(\infty) + C_L/R_L, with C{\epsilon}(\infty) = 0.47 and C_L = 19.1
obtained from DNS data.
  Theoretical methods based on RG and statistical closures are still being
developed to study turbulence. The dynamic RG procedure used by Forster, Nelson
and Stephen (FNS) is considered in some detail and a disagreement in the
literature is resolved here. The application of statistical closure and
renormalized perturbation theory is discussed and a new two-time model
probability density functional presented.

categories: physics.flu-dyn math-ph math.MP physics.comp-ph


title:
Constrained fractional set programs and their application in local
  clustering and community detection

abstract:
  The (constrained) minimization of a ratio of set functions is a problem
frequently occurring in clustering and community detection. As these
optimization problems are typically NP-hard, one uses convex or spectral
relaxations in practice. While these relaxations can be solved globally
optimally, they are often too loose and thus lead to results far away from the
optimum. In this paper we show that every constrained minimization problem of a
ratio of non-negative set functions allows a tight relaxation into an
unconstrained continuous optimization problem. This result leads to a flexible
framework for solving constrained problems in network analysis. While a
globally optimal solution for the resulting non-convex problem cannot be
guaranteed, we outperform the loose convex or spectral relaxations by a large
margin on constrained local clustering problems.


title: The Stable Rank of C*-modules

abstract:
  We prove equality between the Topological Stable Rank and the Bass Stable
Rank for finitely generated projective left modules over a unital C*-algebra.
In order to do so, the concept of Stable Rank of a Hilbert module is
introduced.


title: Bilinear Ideals in Operator Spaces

abstract:
  We introduce a concept of bilinear ideal of jointly completely bounded
mappings between operator spaces. In particular, we study the bilinear ideals
$\mathcal{N}$ of completely nuclear, $\mathcal{I }$ of completely integral,
$\mathcal{E}$ of completely extendible bilinear mappings, $\mathcal{MB}$
multiplicatively bounded and its symmetrization $\mathcal{SMB}$. We prove some
basic properties of them, one of which is the fact that $\mathcal{I}$ is
naturally identified with the ideal of (linear) completely integral mappings on
the injective operator space tensor product.


title:
Planetesimal formation via sweep-up growth at the inner edge of dead
  zones

abstract:
  The early stages of planet formation are still not well understood.
Coagulation models have revealed numerous obstacles to the dust growth, such as
the bouncing, fragmentation and radial drift barriers. We study the interplay
between dust coagulation and drift in order to determine the conditions in
protoplanetary disk that support the formation of planetesimals. We focus on
planetesimal formation via sweep-up and investigate whether it can take place
in a realistic protoplanetary disk. We have developed a new numerical model
that resolves spatial distribution of dust in the radial and vertical
dimension. The model uses representative particles approach to follow the dust
evolution in protoplanetary disk. The coagulation and fragmentation of solids
is taken into account using Monte Carlo method. A collision model adopting the
mass transfer effect, that can occur for different-sized dust aggregate
collisions, is implemented. We focus on a protoplanetary disk including a
pressure bump caused by a steep decline of turbulent viscosity around the snow
line. Our results show that sufficient resolution of the vertical disk
structure in dust coagulation codes is necessary to obtain adequately short
growth timescales, especially in the case of a low turbulence region. We find
that a sharp radial variation of the turbulence strength at the inner edge of
dead zone promotes planetesimal formation in several ways. It provides a
pressure bump that efficiently prevents the dust from drifting inwards. It also
causes a radial variation in the size of aggregates at which growth barriers
occur, favoring the growth of large aggregates via sweeping up of small
particles. In our model, by employing an ad hoc alpha viscosity change near the
snow line, it is possible to grow planetesimals by incremental growth on
timescales of approximately 10^5 years.


title:
Low-Dilution Limit of Zn_{1-x}Mn_{x}GeAs_{2}: electrical and magnetic
  properties

abstract:
  We present the studies of electrical transport and magnetic interactions in
Zn_{1-x}Mn_{x}GeAs_{2} crystals with low Mn content 0 \leq x \leq 0.043. We
show that the ionic-acceptor defects are mainly responsible for the strong
p-type conductivity of our samples. We found that the negative
magnetoresistance (MR) with maximum values of about -50% is related to the weak
localization phenomena. The magnetic properties of Zn1-xMnxGeAs2 samples show
that the random Mn-distribution in the cation sites of the host lattice occurs
only for the sample with the lowest Mn-content, x=0.003. The samples with
higher Mn-content show a high level of magnetic frustration. Nonzero
Curie-Weiss temperature observed in all our samples indicates that weak
ferromagnetic (for x=0.003) or antiferromagnetic (for x>0.005) interactions
with |{\Theta}|<3 K are present in this system. The RKKY model, used to
estimate the Mn-hole exchange integral Jpd for the diluted
Zn/0.997/Mn/0.003/GeAs/2/ sample, makes possible to estimate the value of Jpd
=(0.75+/-0.09) eV.


title: Slime Mould Memristors

abstract:
  In laboratory experiments we demonstrate that protoplasmic tubes of acellular
slime mould \emph{Physarum polycephalum} show current versus voltage profiles
consistent with memristive systems and that the effect is due to the living
protoplasm of the mould. This complements previous findings on memristive
properties of other living systems (human skin and blood) and contributes to
development of self-growing bio-electronic circuits. Distinctive asymmetric
$V$-$I$ curves which were occasionally observed when the internal current is on
the same order as the driven current, are well-modelled by the concept of
active memristors.


title: Live-wire 3D medical images segmentation

abstract:
  This report describes the design, implementation, evaluation and original
enhancements to the Live-Wire method for 2D and 3D image segmentation.
Live-Wire 2D employs a semi-automatic paradigm; the user is asked to select a
few boundary points of the object to segment, to steer the process in the right
direction, while the result is displayed in real time. In our implementation
segmentation is extended to three dimensions by performing this process on a
slice-by-slice basis. User's time and involvement is further reduced by
allowing him to specify object contours in planes orthogonal to the slices. If
these planes are chosen strategically, Live-Wire 3D can perform 2D segmentation
in the plane of each slice automatically. This report also proposes two
improvements to the original method, path heating and a new graph edge feature
function based on variance of path properties along the boundary. We show that
these improvements lead up to a 33% reduction in interaction with the user, and
improved delineation in presence of strong interfering edges.


title: Percolation of a general network of networks

abstract:
  Percolation theory is an approach to study vulnerability of a system. We
develop analytical framework and analyze percolation properties of a network
composed of interdependent networks (NetONet). Typically, percolation of a
single network shows that the damage in the network due to a failure is a
continuous function of the fraction of failed nodes. In sharp contrast, in
NetONet, due to the cascading failures, the percolation transition may be
discontinuous and even a single node failure may lead to abrupt collapse of the
system. We demonstrate our general framework for a NetONet composed of $n$
classic Erd\H{o}s-R\'{e}nyi (ER) networks, where each network depends on the
same number $m$ of other networks, i.e., a random regular network of
interdependent ER networks. In contrast to a \emph{treelike} NetONet in which
the size of the largest connected cluster (mutual component) depends on $n$,
the loops in the RR NetONet cause the largest connected cluster to depend only
on $m$. We also analyzed the extremely vulnerable feedback condition of
coupling. In the case of ER networks, the NetONet only exhibits two phases, a
second order phase transition and collapse, and there is no first phase
transition regime unlike the no feedback condition. In the case of NetONet
composed of RR networks, there exists a first order phase transition when $q$
is large and second order phase transition when $q$ is small. Our results can
help in designing robust interdependent systems.


title: Testing the Hadronuclear Origin of PeV Neutrinos Observed with IceCube

abstract:
  We consider implications of the IceCube excess for hadronuclear (pp)
scenarios of neutrino sources such as galaxy clusters/groups and star-forming
galaxies. Since the observed neutrino flux is comparable to the diffuse
gamma-ray background flux obtained by Fermi, we place new, strong upper limits
on the source spectral index, {\Gamma}<2.1-2.2. In addition, the new IceCube
data imply that these sources contribute at least 30%-40% of the diffuse
gamma-ray background in the 100 GeV range and even ~100% for softer spectra.
Our results, which are insensitive to details of the pp source models, are one
of the first strong examples of the multimessenger approach combining the
measured neutrino and gamma-ray fluxes. The pp origin of the IceCube excess can
further be tested by constraining {\Gamma} with sub-PeV neutrino observations,
by unveiling the sub-TeV diffuse gamma-ray background and by observing such pp
sources with TeV gamma-ray detectors. We also discuss specific pp source models
with a multi-PeV neutrino break/cutoff, which are consistent with the current
IceCube data.


title:
A Short Note on Two-Variable Logic with a Linear Order Successor and a
  Preorder Successor

abstract:
  The finite satisfiability problem of two-variable logic extended by a linear
order successor and a preorder successor is shown to be undecidable.


title: Dynamics of quantum turbulence of different spectra

abstract:
  Turbulence in a superfluid in the zero temperature limit consists of a
dynamic tangle of quantized vortex filaments. Different types of turbulence are
possible depending on the level of correlations in the orientation of vortex
lines. We provide an overview of turbulence in superfluid $^4$He with a
particular focus on recent experiments probing the decay of turbulence in the
zero temperature regime below 0.5 K. We describe extensive measurements of the
vortex line density during the free decay of different types of turbulence:
ultraquantum and quasiclassical turbulence in both stationary and rotating
containers. The observed decays and the effective dissipation as a function of
temperature are compared with theoretical models and numerical simulations.


title:
Algebraic Birkhoff Factorization and the Euler-Maclaurin Formula on
  Cones

abstract:
  We equip the space of lattice cones with a coproduct which makes it a
connected cograded colagebra. The exponential sum and exponential integral on
lattice cones can be viewed as linear maps on this space with values in the
space of meromorphic germs with linear poles at zero. We investigate the
subdivision properties-- reminiscent of the inclusion-exclusion principle for
the cardinal on finite sets-- of such linear maps and establish a compatibility
of these properties with respect to the convolution quotient of the coalgebra.
Implementing the Algebraic Birkhoff Factorization procedure on the linear maps
under consideration, we factorize the exponential sum as a convolution quotient
of two maps, with each of the maps in the factorization satisfying a
subdivision property. Consequently, the Algebraic Birkhoff Factorization
specializes to the Euler-Maclaurin formula on lattice cones and provides a
simple formula for the interpolating factor by means of a projection map.


title: The entropic lock and key of the histone code

abstract:
  The intricate pattern of chemical modifications on DNA and histones, the
"histone code", is considered to be a key gene regulation factor. Multivalency
is seen by many as an essential instrument to transmit the "encoded"
information to the transcription machinery via multi-domain effector proteins
and chromatin-associated complexes. However, as examples of multivalent histone
engagement accumulate, an apparent contradiction is emerging. The isolated
effector domains are notably weak binders, thus it is often asserted that the
entropic cost of orienting multiple domains can be "prepaid" by a rigid tether.
Meanwhile, evidence suggests that the tethers are largely disordered and offer
little rigidity. Here we consider a mechanism to "prepay" the entropic costs of
orienting the domains for binding, not through rigidity of the tether but
through the careful spacing of the modifications on chromatin. An all-atom
molecular dynamics study of the most fully characterized multivalent chromatin
effector conforms to the conditions for an optimal free-energy payout, as
predicted by the model discussed here.


title: Spontaneous centralization of control in a network of company ownerships

abstract:
  We introduce a model for the adaptive evolution of a network of company
ownerships. In a recent work it has been shown that the empirical global
network of corporate control is marked by a central, tightly connected "core"
made of a small number of large companies which control a significant part of
the global economy. Here we show how a simple, adaptive "rich get richer"
dynamics can account for this characteristic, which incorporates the increased
buying power of more influential companies, and in turn results in even higher
control. We conclude that this kind of centralized structure can emerge without
it being an explicit goal of these companies, or as a result of a
well-organized strategy.


title:
Capillary leveling of stepped films with inhomogeneous molecular
  mobility

abstract:
  A homogeneous thin polymer film with a stepped height profile levels due to
the presence of Laplace pressure gradients. Here we report on studies of
polymeric samples with precisely controlled, spatially inhomogeneous molecular
weight distributions. The viscosity of a polymer melt strongly depends on the
chain length distribution; thus, we learn about thin-film hydrodynamics with
viscosity gradients. These gradients are achieved by stacking two films with
different molecular weights atop one another. After a sufficient time these
samples can be well described as having one dimensional viscosity gradients in
the plane of the film, with a uniform viscosity normal to the film. We develop
a hydrodynamic model that accurately predicts the shape of the experimentally
observed self-similar profiles. The model allows for the extraction of a
capillary velocity, the ratio of the surface tension and the viscosity, in the
system. The results are in excellent agreement with capillary velocity
measurements of uniform mono- and bi-disperse stepped films and are consistent
with bulk polymer rheology.

categories: cond-mat.soft cond-mat.mes-hall cond-mat.mtrl-sci physics.chem-ph physics.flu-dyn


title:
Method of evaluating chemical shifts of X-ray emission lines in
  molecules and solids

abstract:
  Method of evaluating chemical shifts of X-ray emission lines for sufficiently
heavy atoms (beginning from period 4 elements) in chemical compounds is
developed. This method is based on the pseudopotential model and one-center
restoration method (to reconstruct the proper electronic structure in
heavy-atom cores). The approximations of instantaneous transition and frozen
inner core spinors of the atom are used for derivation of an expression for
chemical shift as a difference between mean values of some effective operator.
The method allows one to avoid evaluating small values (chemical shifts ~$
0.01{-}1$ eV) as differences of very large values (transition energies ~
$1{-}100$ keV in various compounds). The results of our calculations of
chemical shifts for the $K\alpha_1$, $K\alpha_2$, and L transitions of the
group 14 metal cations with respect to neutral atoms are presented. The
calculations of chemical shift of $K\alpha_1$-line in the Pb-core transition
within PbO and PbF$_2$ with respect to the neutral Pb are also performed and
discussed. The accuracy of the used approximations is discussed and quality of
the performed calculations is analyzed.


title:
A complete characterisation of the heralded noiseless amplification of
  photons

abstract:
  Heralded noiseless amplifcation of photons has recently been shown to provide
a means to overcome losses in complex quantum communication tasks. In
particular, to overcome transmission losses that could allow for the violation
of a Bell inequality free from the detection loophole, for Device Independent
Quantum Key Distribution (DI-QKD). Several implementations of a heralded photon
amplifier have been proposed and the first proof of principle experiments
realised. Here we present the first full characterisation of such a device to
test its functional limits and potential for DI-QKD. This device is tested at
telecom wavelengths and is shown to be capable of overcoming losses
corresponding to a transmission through $20\, \rm km$ of single mode telecom
fibre. We demonstrate heralded photon amplifier with a gain $>100$ and a
heralding probability $>83 % $, required by DI-QKD protocols that use the
Clauser-Horne-Shimony-Holt (CHSH) inequality. The heralded photon amplifier
clearly represents a key technology for the realisation of DI-QKD in the real
world and over typical network distances.


title:
Valuating Surface Surveillance Technology for Collaborative
  Multiple-Spot Control of Airport Departure Operations

abstract:
  Airport departure operations are a source of airline delays and passenger
frustration. Excessive surface traffic is a cause of increased controller and
pilot workload. It is also a source of increased emissions and delays, and does
not yield improved runway throughput. Leveraging the extensive past research on
airport departure management, this paper explores the environmental and safety
benefits that improved surveillance technologies can bring in the context of
gate- or spot-release strategies. The paper shows that improved surveillance
technologies can yield 4% to 6% reduction of aircraft on taxiway, and therefore
emissions, in addition to the savings currently observed by implementing
threshold starategies under evaluation at Boston Logan Airport and other busy
airports during congested periods. These calculated benefits contrast sharply
with our previous work, which relied on simplified airport ramp areas with a
single departure spot, and where fewer environmental and economic benefits of
advanced surface surveillance systems could be established. Our work is
illustrated by its application to New-York LaGuardia and Seattle Tacoma
airports.


title:
Phylogenetic analysis accounting for age-dependent death and sampling
  with applications to epidemics

abstract:
  The reconstruction of phylogenetic trees based on viral genetic sequence data
sequentially sampled from an epidemic provides estimates of the past
transmission dynamics, by fitting epidemiological models to these trees. To our
knowledge, none of the epidemiological models currently used in phylogenetics
can account for recovery rates and sampling rates dependent on the time elapsed
since transmission.
  Here we introduce an epidemiological model where infectives leave the
epidemic, either by recovery or sampling, after some random time which may
follow an arbitrary distribution.
  We derive an expression for the likelihood of the phylogenetic tree of
sampled infectives under our general epidemiological model. The analytic
concept developed in this paper will facilitate inference of past
epidemiological dynamics and provide an analytical framework for performing
very efficient simulations of phylogenetic trees under our model. The main idea
of our analytic study is that the non-Markovian epidemiological model giving
rise to phylogenetic trees growing vertically as time goes by, can be
represented by a Markovian "coalescent point process" growing horizontally by
the sequential addition of pairs of coalescence and sampling times.
  As examples, we discuss two special cases of our general model, namely an
application to influenza and an application to HIV. Though phrased in
epidemiological terms, our framework can also be used for instance to fit
macroevolutionary models to phylogenies of extant and extinct species,
accounting for general species lifetime distributions.


title: Chaotic oscillations in singularly perturbed FitzHugh-Nagumo systems

abstract:
  We consider the singularly perturbed limit of periodically excited
two-dimensional FitzHugh-Nagumo systems. We show that the dynamics of such
systems are essentially governed by an one-dimensional map and present a
numerical scheme to accurately compute it together with its Lyapunov exponent.
We then investigate the occurrence of chaos by varying the parameters of the
system, with especial emphasis on the simplest possible chaotic oscillations.
Our results corroborate and complement some recent works on bifurcations and
routes to chaos in certain particular cases corresponding to piecewise linear
FitzHugh-Nagumo-like systems.


title: Impact of Gate Assignment on Gate-Holding Departure Control Strategies

abstract:
  Gate holding reduces congestion by reducing the number of aircraft present on
the airport surface at any time, while not starving the runway. Because some
departing flights are held at gates, there is a possibility that arriving
flights cannot access the gates and have to wait until the gates are cleared.
This is called a gate conflict. Robust gate assignment is an assignment that
minimizes gate conflicts by assigning gates to aircraft to maximize the time
gap between two consecutive flights at the same gate; it makes gate assignment
robust, but passengers may walk longer to transfer flights. In order to
simulate the airport departure process, a queuing model is introduced. The
model is calibrated and validated with actual data from New York La Guardia
Airport (LGA) and a U.S. hub airport. Then, the model simulates the airport
departure process with the current gate assignment and a robust gate assignment
to assess the impact of gate assignment on gate-holding departure control. The
results show that the robust gate assignment reduces the number of gate
conflicts caused by gate holding compared to the current gate assignment.
Therefore, robust gate assignment can be combined with gate-holding departure
control to improve operations at congested airports with limited gate
resources.


title:
First-Principles Studies of Photoinduced Charge Transfer in
  Noncovalently Functionalized Carbon Nanotubes

abstract:
  We have studied the energetics, electronic structure, optical excitation, and
electron relaxation of dinitromethane molecules (CH$_{2}$N$_{2}$O$_{4}$)
adsorbed on semiconducting carbon nanotubes (CNTs) of chiral index (n,0) (n=7,
10, 13, 16, 19). Using first-principles density functional theory (DFT) with
generalized gradient approximations and van der Waals corrections, we have
calculated adsorption energies of dinitropentylpyrene, in which the
dinitromethane is linked to the pyrene via an aliphatic chain, on a CNT. A
75.26 kJ/mol binding energy has been found, which explains why such aliphatic
chain-pyrene units can be and have been used in experiments to bind functional
molecules to CNTs. The calculated electronic structures show that the
dinitromethane introduces a localized state inside the band gap of CNT systems
of n=10, 13, 16 and 19; such a state can trap an electron when the CNT is
photoexcited. We have therefore investigated the dynamics of intra-band
relaxations using the reduced density matrix formalism in conjunction with DFT.
For pristine CNTs, we have found that the calculated charge relaxation
constants agree well with the experimental time scales. Upon adsorption, these
constants are modified, but there is not a clear trend for the direction and
magnitude of the change. Nevertheless, our calculations predict that electron
relaxation in the conduction band is faster than hole relaxation in the valence
band for CNTs with and without molecular adsorbates.


title:
Star-forming fractions and galaxy evolution with redshift in rich
  X-ray-selected galaxy clusters

abstract:
  We have compared stacked spectra of galaxies, grouped by environment and
stellar mass, among 58 members of the redshift z = 1.24 galaxy cluster RDCS
J1252.9-2927 (J1252.9) and 134 galaxies in the z = 0.84 cluster RX J0152.7-1357
(J0152.7). These two clusters are excellent laboratories to study how galaxies
evolve from star-forming to passive at z ~ 1. We measured spectral indices and
star-forming fractions for our density- and mass-based stacked spectra. The
star-forming fraction among low-mass galaxies (< 7 x 10^10 M_sun) is higher in
J1252.9 than in J0152.7, at about 4 sigma significance. Thus star formation is
being quenched between z = 1.24 and z = 0.84 for a substantial fraction of
low-mass galaxies. Star-forming fractions were also found to be higher in
J1252.9 in all environments, including the core. Passive galaxies in J1252.9
have systematically lower D_n4000 values than in J0152.7 in all density and
mass groups, consistent with passive evolution at modestly super-solar
metallicities.


title: Supporting Lemmas for RISE-based Control Methods

abstract:
  A class of continuous controllers termed Robust Integral of the Signum of the
Error (RISE) have been published over the last decade as a means to yield
asymptotic convergence of the tracking error for classes of nonlinear systems
that are subject to exogenous disturbances and/or modeling uncertainties. The
development of this class of controllers relies on a property related to the
integral of the signum of an error signal. A proof for this property is not
available in previous literature. The stability of some RISE controllers is
analyzed using differential inclusions. Such results rely on the hypothesis
that a set of points is Lebesgue negligible. This paper states and proves two
lemmas related to the properties.


title: Room temperature multiferroism in CaTcO$_3$ by interface engineering

abstract:
  The structural instabilities of ATcO$_3$(A= Ca, Sr, Ba) are investigated by
first-principles calculations. In addiction to the large octahedral rotation
instability, a weak ferroelectric tendency is identified in CaTcO$_3$. We show
that the ferroelectricity in CaTcO$_3$ can be recovered by interface
engineering based on CaTcO$_3$/BaTcO$_3$ superlattices, where the octahedral
rotation is largely suppressed. The N{\'e}el temperature is found to be $\sim$
816 K, indicating that CaTcO$_3$ can be engineered into a new room temperature
multiferroic material.


title:
Delicacy of the Riemann hypothesis and certain subsequences of
  superabundant numbers

abstract:
  Robin's theorem is one of the ingenious reformulation of the Riemann
hypothesis (RH). It states that the RH is true if and only if
$\sigma(n)<e^\gamma n\log\log n$ for all $n>5040$ where $\sigma(n)$ is the sum
of divisors of $n$ and $\gamma$ is Euler's constant. In this paper we show that
how the RH is delicate in terms of certain subsets of superabundant numbers,
namely extremely abundant numbers and some of its specific supersets.


title:
New insight into light propagation and light-matter interactions with
  applications to experimental observations

abstract:
  The paper provides a new understanding of light propagation and light-matter
interactions by examining the physical implications of group velocity,
electromagnetic (EM) power flow, Poynting theorem, energy conservation law, and
Fermat's principle. A criterion is set up to identify the justification of the
group velocity definition, and a modified definition is proposed to remove the
flaws that the classical definition has. It is reasonably argued that energy
conservation law and Fermat's principle are physical postulates independent of
Maxwell equations. A ``superluminal power flow'' is constructed to show that
Poynting theorem cannot uniquely define the EM power flow if the energy
conservation law or Fermat's principle is not taken into account. As an
application, associated basic concepts in textbooks and experimental
observations reported in recent research works are also reviewed, including:
why the traditional formulation of Fermat's principle has a limited
application; how the Fermat's principle is formulated for a plane wave; why the
Fermat's principle is consistent with Maxwell EM theory; what the significant
difference is between Poynting theorem and energy conservation law; why
Poynting vector as EM power flow may break energy conservation law and Fermat's
principle in an anisotropic medium; why the physical explanations for
``spatially structured'' photons in Giovannini-coworkers experiments are not
consistent with the principle of relativity; why the traditionally-argued
invariance of information velocity contradicts Maxwell equations; and why the
superluminal light pulse propagation claimed in Wang-Kuzmich-Dogariu
experiments voilates Einstein causality.


title: MCPLOTS: a particle physics resource based on volunteer computing

abstract:
  The mcplots.cern.ch web site (MCPLOTS) provides a simple online repository of
plots made with high-energy-physics event generators, comparing them to a wide
variety of experimental data. The repository is based on the HEPDATA online
database of experimental results and on the RIVET Monte Carlo analysis tool.
The repository is continually updated and relies on computing power donated by
volunteers, via the LHC@HOME platform.


title:
A cutting surface algorithm for semi-infinite convex programming with an
  application to moment robust optimization

abstract:
  We present and analyze a central cutting surface algorithm for general
semi-infinite convex optimization problems, and use it to develop a novel
algorithm for distributionally robust optimization problems in which the
uncertainty set consists of probability distributions with given bounds on
their moments. Moments of arbitrary order, as well as non-polynomial moments
can be included in the formulation. We show that this gives rise to a hierarchy
of optimization problems with decreasing levels of risk-aversion, with classic
robust optimization at one end of the spectrum, and stochastic programming at
the other. Although our primary motivation is to solve distributionally robust
optimization problems with moment uncertainty, the cutting surface method for
general semi-infinite convex programs is also of independent interest. The
proposed method is applicable to problems with non-differentiable semi-infinite
constraints indexed by an infinite-dimensional index set. Examples comparing
the cutting surface algorithm to the central cutting plane algorithm of
Kortanek and No demonstrate the potential of our algorithm even in the solution
of traditional semi-infinite convex programming problems whose constraints are
differentiable and are indexed by an index set of low dimension. After the rate
of convergence analysis of the cutting surface algorithm, we extend the
authors' moment matching scenario generation algorithm to a probabilistic
algorithm that finds optimal probability distributions subject to moment
constraints. The combination of this distribution optimization method and the
central cutting surface algorithm yields a solution to a family of
distributionally robust optimization problems that are considerably more
general than the ones proposed to date.


title:
Rigidity results for non local phase transitions in the Heisenberg group
  $H$

abstract:
  In the Heisenberg group framework, we study rigidity properties for stable
solutions of $(-\Delta_H)^s v = f(v)$ in $H$, $s \in (0,1)$. We obtain a
Poincar\'e type inequality in connection with a degenerate elliptic equation in
$\R^4_+$; through an extension (or "lifting") procedure, this inequality will
be then used for giving a criterion under which the level sets of the above
solutions are minimal surfaces in $H$, i.e. they have vanishing mean curvature.


title:
Elliptic and triangular flow anisotropy in deuteron-gold collisions at
  RHIC and proton-lead collisions at the LHC

abstract:
  We study elliptic and triangular flow in the collisions of deuteron-gold
nuclei at $\sqrt{s_{\rm NN}} = 200$ GeV at RHIC and of proton-lead nuclei at
$\sqrt{s_{\rm NN}} = 5.02$ TeV at the LHC, utilizing (3+1)-dimensional ideal
hydrodynamics for the dynamic evolution of the fireball and a Glauber-based
Monte-Carlo energy deposition model for simulating the fluctuating initial
conditions. Sizable values of elliptic and triangular flow are obtained for
both colliding systems, and the results are consistent with PHENIX, ALICE,
ATLAS and CMS measurements. For these studied centralities, we find that the
elliptic flow in proton-lead collisions is smaller than deuteron-gold
collisions, while the triangular flows are comparable in both colliding
systems. Our results indicate that the observed collective anisotropic flow in
deuteron-gold and proton-lead collisions may be obtained from relativistic
hydrodynamic evolution of the fireball with initial state fluctuations.


title:
Comparison of OFDM and SC-DFE Capacities Without Channel Knowledge at
  the Transmitter

abstract:
  This letter provides a capacity analysis between OFDM and the ideal SC-DFE
when no channel knowledge is available at the transmitter. Through some
algebraic manipulation of the OFDM and SC-DFE capacities and using the
concavity property of the manipulated capacity function and Jensen's
inequality, we are able to prove that the SC-DFE capacity is always superior to
that of an OFDM scheme for 4- and 16-QAM for any given channel. For
higher-order modulations, however, the results indicate that OFDM may only
surpass the ideal SC-DFE capacity by a small amount in some specific scenarios.