title:
Virulence as a Model for Interplanetary and Interstellar Colonisation -
  Parasitism or Mutualism

abstract:
  In the light of current scientific assessments of human-induced climate
change, we investigate an experimental model to inform how resource-use
strategies may influence interplanetary and interstellar colonisation by
intelligent civilisations. In doing so, we seek to provide an additional aspect
for refining the famed Fermi Paradox. The model described is necessarily
simplistic, and the intent is to simply obtain some general insights to inform
and inspire additional models. We model the relationship between an intelligent
civilisation and its host planet as symbiotic, where the the relationship
between the symbiont and the host species (the civilisation and the planets
ecology, respectively) determines the fitness and ultimate survival of both
organisms.
  We perform a series of Monte Carlo Realisation simulations, where
civilisations pursue a variety of different relationships/strategies with their
host planet, from mutualism to parasitism, and can consequently 'infect' other
planets/hosts. We find that parasitic civilisations are generally less
effective at survival than mutualist civilisations, provided that interstellar
colonisation is inefficient (the maximum velocity of colonisation/infection is
low). However, as the colonisation velocity is increased, the strategy of
parasitism becomes more successful, until they dominate the 'population'. This
is in accordance with predictions based on island biogeography and r/K
selection theory. While heavily assumption dependent, we contend that this
provides a fertile approach for further application of insights from
theoretical ecology for extraterrestrial colonisation - while also potentially
offering insights for understanding the human-Earth relationship and the
potential for extraterrestrial human colonisation.


title: Investigating potential planetary nebula/cluster pairs

abstract:
  Fundamental parameters characterizing the end-state of intermediate-mass
stars may be constrained by discovering planetary nebulae (PNe) in open
clusters (OCs). Cluster membership may be exploited to establish the distance,
luminosity, age, and physical size for PNe, and the intrinsic luminosity and
mass of its central star. Four potential PN-OC associations were investigated,
to assess the cluster membership for the PNe. Radial velocities were measured
from intermediate-resolution optical spectra, complemented with previous
estimates in the literature. When the radial velocity study supported the PN/OC
association, we analyzed if other parameters (e.g., age, distance, reddening,
central star brightness) were consistent with this conclusion. Our measurements
imply that the PNe VBe3 and HeFa1 are not members of the OCs NGC5999 and
NGC6067, respectively, and likely belong to the background bulge population.
Conversely, consistent radial velocities indicate that NGC2452/NGC2453 could be
associated, but our results are not conclusive and additional observations are
warranted. Finally, we demonstrate that all the available information point to
He2-86 being a young, highly internally obscured PN member of NGC4463. New
near-infrared photometry acquired via the Vista Variables in the Via Lactea ESO
public survey was used in tandem with existing UBV photometry to measure the
distance, reddening, and age of NGC4463, finding d=1.55+-0.10 kpc,
E(B-V)=0.41+-0.02, and tau=65+-10 Myr, respectively. The same values should be
adopted for the PN if the proposed cluster membership will be confirmed.


title:
Null controllability for parabolic equations with dynamic boundary
  conditions of reactive-diffusive type

abstract:
  We prove null controllability for linear and semilinear heat equations with
dynamic boundary conditions of surface diffusion type. The results are based on
a new Carleman estimate for this type of boundary conditions.


title: Observation of $Z_c(3900)$ both by BESIII and Belle

abstract:
  Using $525$ pb$^{-1}$ data collected with the BESIII detector at $e^+e^-$
central-of-mass energy 4.26 GeV, the BESIII Collaboration observed a charged
charmoniumlike state $Z_c(3900)\to\pi^{\pm}J/\psi$ with mass
$M[Z_c(3900)]=3899.0\pm 3.6 \pm 4.9$ MeV/c$^2$, and width
$\Gamma[Z_c(3900)]=46\pm 10 \pm 20$ MeV. The significance of this state was
estimated to be $>8\sigma$ in all kinds of systematic tests. Using $967$
fb$^{-1}$ data recorded by the Belle detector on or near $\Upsilon(nS)$, n=1,
2, $\cdots$, 5 resonances, the $e^+e^- \to \pi^+\pi^-J/\psi$ process has been
studied through initial-state-radiation (ISR) method. Except for the $Y(4260)$
resonance, an intermediate state $Z(3900)^{\pm}$ has been observed in the
$\pi^{\pm}J/\psi$ mass spectrum, with significance $>5.2\sigma$. The measured
mass $M[Z(3900)^{\pm}]=3894.5\pm6.6\pm4.5$ MeV/c$^2$ and width
$\Gamma[Z(3900)^{\pm}]=63\pm24\pm26$ MeV, shows good agreement with the BESIII
measurement within errors, which means $Z_c(3900)$ and $Z(3900)^{\pm}$ is the
same state.


title: Gravitomagnetism and Non-commutative Geometry

abstract:
  Similarity between the gravitoelectromagnetism and the electromagnetism is
discussed. We show that the gravitomagnetic field (similar to the magnetic
field) can be equivalent to the non-commutative effect of the momentum sector
of the phase space when one maintains only the first order of the
non-commutative parameters. This is performed through two approaches. In one
approach, by employing the Feynman proof, the existence of a Lorentz-like force
in the gravitoelectromagnetism is indicated. The appearance of such a force is
subjected to the slow motion and the weak field approximations for stationary
fields. The analogy between this Lorentz-like force and the motion equation of
a test particle in a non-commutative space leads to the mentioned equivalency.
In fact, this equivalency is achieved by the comparison of the two motion
equations. In the other and quietly independent approach, we demonstrate that a
gravitomagnetic background can be treated as a Dirac constraint. That is, the
gravitoelectromagnetic field can be regarded as a constrained system from the
sense of the Dirac theory. Indeed, the application of the Dirac formalism for
the gravitoelectromagnetic field reveals that the phase space coordinates have
non-commutative structure from the view of the Dirac bracket. Particularly, the
gravitomagnetic field as a weak field induces the non-trivial Dirac bracket of
the momentum sector which displays the non-commutativity.

categories: gr-qc hep-th math-ph math.MP physics.class-ph


title: Submatrices of Hadamard matrices: complementation results

abstract:
  Two submatrices $A,D$ of a Hadamard matrix $H$ are called complementary if,
up to a permutation of rows and columns, $H=[^A_C{\ }^B_D]$. We find here an
explicit formula for the polar decomposition of $D$. As an application, we show
that under suitable smallness assumptions on the size of $A$, the complementary
matrix $D$ is an almost Hadamard sign pattern, i.e. its rescaled polar part is
an almost Hadamard matrix.


title: The Tao of It and Bit

abstract:
  The main mystery of quantum mechanics is contained in Wheeler's delayed
choice experiment, which shows that the past is determined by our choice of
what quantum property to observe. This gives the observer a participatory role
in deciding the past history of the universe. Wheeler extended this
participatory role to the emergence of the physical laws ("law without law").
Since what we know about the universe comes in yes/no answers to our
interrogations, this led him to the idea of "it from bit" (which includes the
participatory role of the observer as a key component).
  The yes/no answers to our observations ("bit") should always be compatible
with the existence of at least a possible reality - a global solution ("it") of
the Schrodinger equation. I argue that there is in fact an interplay between
"it" and "bit". The requirement of global consistency leads to apparently
acausal and nonlocal behavior, explaining the weirdness of quantum phenomena.
  As an interpretation of Wheeler's "it from bit" and "law without law", I
discuss the possibility that the universe is mathematical, and that there is a
"mother of all possible worlds" - named the "Axiom Zero".


title: Polyhedral Covers of Tree Space

abstract:
  The phylogenetic tree space, introduced by Billera, Holmes, and Vogtmann, is
a cone over a simplicial complex. In this short article, we construct this
complex from local gluings of classical polytopes, the associahedron and the
permutohedron. Its homotopy is also reinterpreted and calculated based on
polytope data.


title: Weak symmetry breaking in two dimensional topological insulators

abstract:
  We show that there exist two dimensional (2D) time reversal invariant
fractionalized insulators with the property that both their boundary with the
vacuum and their boundary with a topological insulator can be fully gapped
without breaking time reversal or charge conservation symmetry. This result
leads us to an apparent paradox: we consider a geometry in which a disk-like
region made up of a topological insulator is surrounded by an annular strip of
a fractionalized insulator, which is in turn surrounded by the vacuum. If we
gap both boundaries of the strip, we naively obtain an example of a gapped
interface between a topological insulator and the vacuum that does not break
any symmetries -- an impossibility. The resolution of this paradox is that this
system spontaneously breaks time reversal symmetry in an unusual way, which we
call \emph{weak symmetry breaking}. In particular, we find that the only order
parameters that are sensitive to the symmetry breaking are nonlocal operators
that describe quasiparticle tunneling processes between the two edges of the
strip; expectation values of local order parameters vanish exponentially in the
limit of a wide strip. Also, we find that the symmetry breaking in our system
comes with a ground state degeneracy, but this ground state degeneracy is
topologically protected, rather than symmetry protected. We show that this kind
of symmetry breaking can also occur at the edge of 2D fractional topological
insulators.


title: Abstract Acceleration of General Linear Loops

abstract:
  We present abstract acceleration techniques for computing loop invariants for
numerical programs with linear assignments and conditionals. Whereas abstract
interpretation techniques typically over-approximate the set of reachable
states iteratively, abstract acceleration captures the effect of the loop with
a single, non-iterative transfer function applied to the initial states at the
loop head. In contrast to previous acceleration techniques, our approach
applies to any linear loop without restrictions. Its novelty lies in the use of
the Jordan normal form decomposition of the loop body to derive symbolic
expressions for the entries of the matrix modeling the effect of n>=0
iterations of the loop. The entries of such a matrix depend on $n$ through
complex polynomial, exponential and trigonometric functions. Therefore, we
introduces an abstract domain for matrices that captures the linear inequality
relations between these complex expressions. This results in an abstract matrix
for describing the fixpoint semantics of the loop.
  Our approach integrates smoothly into standard abstract interpreters and can
handle programs with nested loops and loops containing conditional branches. We
evaluate it over small but complex loops that are commonly found in control
software, comparing it with other tools for computing linear loop invariants.
The loops in our benchmarks typically exhibit polynomial, exponential and
oscillatory behaviors that present challenges to existing approaches. Our
approach finds non-trivial invariants to prove useful bounds on the values of
variables for such loops, clearly outperforming the existing approaches in
terms of precision while exhibiting good performance.


title: Bosonic thermoelectric transport and breakdown of universality

abstract:
  In this paper we compare Bose transport in normal phase atomic gases with its
counterpart in Fermi gases, illustrating the non-universality of two
dimensional bosonic transport associated with different dissipation mechanisms.
Near the superfluid transition temperature $T_c$, a striking similarity between
the fermionic and bosonic transport emerges because super-conducting(fluid)
fluctuation transport for Fermi gases is dominated by the bosonic, Cooper pair
component. As in fluctuation theory, one finds that the Seebeck coefficient
changes sign at $T_c$ and the Lorenz number approaches zero at $T_c$. Our
findings appear semi-quantitatively consistent with recent Bose gas
experiments.


title:
Comment on "Thermodynamic properties of rock-salt ZnO" by Leitner et al.
  [Thermochimica Acta 572 (2013) 1-5]

abstract:
  Very recently Leitner et al. [Thermochimica Acta 572 (2013) 1-5] have tried
to extract the thermodynamic data of rock-salt ZnO from ab initio and
experimental data available in the literature. In this Comment we show that
neglecting (i) the strongly pronounced kinetic features of the pressure-induced
phase transition in ZnO at room temperature and (ii) results of calorimetric
measurements available in the literature [Russ. Chem. Bull. 59 (2010) 325-328]
makes the proposed set of thermodynamic functions completely incorrect.


title:
Discovery of weak 6.7-GHz CH3OH masers in a sample of high-mass Hi-GAL
  sources

abstract:
  Maser lines from different molecular species, including water, hydroxyl, and
methanol, are common observational phenomena associated with massive star
forming regions. In particular, the methanol maser appears as an ideal tool to
study the early phases of massive star formation. However, it is difficult to
establish the exact start of the methanol maser phase, and it would then be
interesting to detect and study low-flux density methanol masers (i.e., < 0.1
Jy or even << 0.1 Jy), in order to determine if they can effectively be used to
mark a specific evolutionary phase in high-mass star formation. Past surveys
have been unable to systematically detect many low-flux density methanol
masers, and thus we do not yet know how many such masers exist in the Galaxy
and what is their physical nature. Out of a sample of 107 observed Hi-GAL
sources we detected a total of 32 methanol masers, with 22 sources being new
and weak (median peak flux density 0.07 Jy) detections, in the Galactic
longitude range [32.0, 59.8]deg. We also detected 12 6.035-GHz OH maser, with 9
objects being new detections. Our survey covers a similar range of source
distances as the "Arecibo Methanol Maser Galactic Plane Survey", but the
methanol masers detected by us are clearly shifted towards lower integrated
flux densities. The newly detected methanol masers are mostly of low-luminosity
and, except for some sources, their weakness is not due to distance effects or
positional offsets. No specific correlation is found with the physical
parameters of the Hi-GAL clumps, except for sources with both CH3OH and OH
masers which tend to have higher mass and luminosity. The intensity of the
methanol masers correlates well with the velocity range of the maser emission,
which suggests that the low brightness of these masers is related to the number
of maser spots in the emitting region and their evolution with time.


title:
Automorphism Groups of Countable Arithmetically Saturated Models of
  Peano Arithmetic

abstract:
  If M,N are countable, arithmetically saturated models of Peano Arithmetic and
Aut(M) is isomorphic to Aut(N), then the Turing-jumps of Th(M) and Th(N) are
recursively equivalent.


title: A Cartan-Hadamard type result for relatively hyperbolic groups

abstract:
  In this article, we prove that if a finitely presented group has an
asymptotic cone which is tree-graded with respect to a precise set of pieces
then it is relatively hyperbolic. This answers a question of M. Sapir.


title:
Physics implications of correlation data from the RHIC and LHC heavy-ion
  programs

abstract:
  Two-dimensional angular correlation data from the STAR experiment at RHIC and
from the LHC experiments provide critical information about dynamical processes
in relativistic heavy-ion collisions. The principal correlation structures of
interest are a broad jet-related peak at small relative azimuth ($\phi$)
extending to large relative pseudorapidity ($\eta$), the dijet ridge at large
relative azimuth, and an independent double ridge on $\phi$ represented by a
quadrupole function. The broad peak at small relative azimuth has been
attributed, in large part, to initial-state fluctuations and hydrodynamic flow
which produce higher-order harmonics on $\phi$. That conjecture is challenged
in this paper. It is shown that the net effect of additional higher harmonic
model elements is to describe small, non-Gaussian (NG) shapes in the broad
jet-related peak. The quadrupole correlation, which is also conventionally
attributed to hydrodynamic flow, is considered within the Balitsky - Fadin -
Kuraev - Lipatov (BFKL) Pomeron framework. Preliminary results using this model
for the quadrupole correlation for particle production from 200 GeV $p+p$
collisions are shown to be consistent with recent data from STAR.


title: Towards the minimal renormalizable supersymmetric $E_6$ model

abstract:
  We find an explicit renormalizable supersymmetric $E_6$ model with all the
ingredients for being realistic. It consists of the Higgs sector
$351'+\overline{351'}+27+\overline{27}$, which breaks $E_6$ directly to the
Standard Model gauge group. Three copies of $27$ dimensional representations
then describe the matter sector, while an extra $27+\overline{27}$ pair is
needed to successfully split the Standard Model Higgs doublet from the heavy
Higgs triplet. We perform the analysis of the vacuum structure and the Yukawa
sector of this model, as well as compute contributions to proton decay. Also,
we show why some other simpler $E_6$ models fail to be realistic at the
renormalizable level.


title: The Composition Theorem for Differential Privacy

abstract:
  Sequential querying of differentially private mechanisms degrades the overall
privacy level. In this paper, we answer the fundamental question of
characterizing the level of overall privacy degradation as a function of the
number of queries and the privacy levels maintained by each privatization
mechanism. Our solution is complete: we prove an upper bound on the overall
privacy level and construct a sequence of privatization mechanisms that
achieves this bound. The key innovation is the introduction of an operational
interpretation of differential privacy (involving hypothesis testing) and the
use of new data processing inequalities. Our result improves over the
state-of-the-art, and has immediate applications in several problems studied in
the literature including differentially private multi-party computation.


title: Natural modes and resonances in a dispersive stratified N-layer medium

abstract:
  The properties of the natural modes in a dispersive stratified N-layer medium
are investigated. The focus is on the (over)completeness properties of these
modes. Also the distribution of the natural frequencies is considered. Both the
degree of (over)completeness and the natural frequency distribution turn out to
be totally different from what is known for the non-dispersive case.


title: Testing our conceptual understanding of V1 function

abstract:
  Here we test our conceptual understanding of V1 function by asking two
experimental questions: 1) How do neurons respond to the spatiotemporal
structure contained in dynamic, natural scenes? and 2) What is the true range
of visual responsiveness and predictability of neural responses obtained in an
unbiased sample of neurons across all layers of cortex? We address these
questions by recording responses to natural movie stimuli with 32 channel
silicon probes. By simultaneously recording from cells in all layers, and
taking all recorded cells, we reduce recording bias that results from "hunting"
for neural responses evoked from drifting bars and gratings. A nonparametric
model reveals that many cells that are visually responsive do not appear to be
captured by standard receptive field models. Using nonlinear Radial Basis
Function kernels in a support vector machine, we can explain the responses of
some of these cells better than standard linear and phase-invariant complex
cell models. This suggests that V1 neurons exhibit more complex and diverse
responses than standard models can capture, ranging from simple and complex
cells strongly driven by their classical receptive fields, to cells with more
nonlinear receptive fields inferred from the nonparametric and RFB model, and
cells that are not visually responsive despite robust firing.


title:
Converting homotopies to isotopies and dividing homotopies in half in an
  effective way

abstract:
  We prove two theorems about homotopies of curves on 2-dimensional Riemannian
manifolds. We show that, for any epsilon > 0, if two simple closed curves are
homotopic through curves of bounded length L, then they are also isotopic
through curves of length bounded by L + epsilon. If the manifold is orientable,
then for any epsilon > 0 we show that, if we can contract a curve gamma
traversed twice through curves of length bounded by L, then we can also
contract gamma through curves bounded in length by L + epsilon.
  Our method involves cutting curves at their self-intersection points and
reconnecting them in a prescribed way. We consider the space of all curves
obtained in this way from the original homotopy, and use a novel approach to
show that this space contains a path which yields the desired homotopy.


title:
The renormalization flow of the hierarchical Anderson model at weak
  disorder

abstract:
  We study the flow of the renormalized model parameters obtained from a
sequence of simple transformations of the 1D Anderson model with long-range
hierarchical hopping. Combining numerical results with a perturbative approach
for the flow equations, we identify three qualitatively different regimes at
weak disorder. For a sufficiently fast decay of the hopping energy, the Cauchy
distribution is the only stable fixed-point of the flow equations, whereas for
sufficiently slowly decaying hopping energy the renormalized parameters flow to
a delta peak fixed-point distribution. In an intermediate range of the hopping
decay, both fixed-point distributions are stable and the stationary solution is
determined by the initial configuration of the random parameters. We present
results for the critical decay of the hopping energy separating the different
regimes.


title:
Dynamics of coronal rain and descending plasma blobs in solar
  prominences: I. Fully ionised case

abstract:
  Observations of active regions and limb prominences often show cold, dense
blobs descending with an acceleration smaller than that of free fall. The
dynamics of these condensations falling in the solar corona is investigated in
this paper using a simple fully ionised plasma model. We find that the presence
of a heavy condensation gives rise to a dynamical rearrangement of the coronal
pressure that results in the formation of a large pressure gradient that
opposes gravity. Eventually this pressure gradient becomes so large that the
blob acceleration vanishes or even points upwards. Then, the blob descent is
characterised by an initial acceleration phase followed by an essentially
constant velocity phase. These two stages can be identified in published
time-distance diagrams of coronal rain events. Both the duration of the first
stage and the velocity attained by the blob increase for larger values of the
ratio of blob to coronal density, for larger blob mass, and for smaller coronal
temperature. Dense blobs are characterised by a detectable density growth (up
to 60% in our calculations) and by a steepening of the density in their lower
part, that could lead to the formation of a shock. They also emit sound waves
that could be detected as small intensity changes with periods of the order of
100 s and lasting between a few and about ten periods. Finally, the curvature
of the falling path is only relevant when a very dense blob falls along
inclined magnetic field lines.


title: Fusion (semi)rings arising from quantum groups

abstract:
  We study the fusion semirings arising from easy quantum groups. We classify
all the possible free ones, answering a question of T. Banica and R. Vergnioux
: these are exactly the fusion rings of quantum groups without any nontrivial
one-dimensional representation. We then classify the possible groups of
one-dimensional representations for free easy quantum groups. As an
application, we give a unified proof of the Haagerup property for a broad class
of easy quantum groups, recovering as special cases previous results by M.
Brannan and F. Lemeux. We end with some considerations on the description of
the full fusion ring in the general case.


title:
Carrier localization and electronic phase separation in a doped
  spin-orbit driven Mott phase in Sr3(Ir1-xRux)2O7

abstract:
  Interest in many strongly spin-orbit coupled 5d-transition metal oxide
insulators stems from mapping their electronic structures to a J=1/2 Mott
phase. One of the hopes is to establish their Mott parent states and explore
these systems' potential of realizing novel electronic states upon carrier
doping. However, once doped, little is understood regarding the role of their
reduced Coulomb interaction U relative to their strongly correlated 3d-electron
cousins. Here we show that, upon hole-doping a candidate J=1/2 Mott insulator,
carriers remain localized within a nanoscale phase separated ground state. A
percolative metal-insulator transition occurs with interplay between localized
and itinerant regions, stabilizing an antiferromagnetic metallic phase beyond
the critical region. Our results demonstrate a surprising parallel between
doped 5d- and 3d-electron Mott systems and suggest either through the near
degeneracy of nearby electronic phases or direct carrier localization that U is
essential to the carrier response of this doped spin-orbit Mott insulator.


title: On the invariant spectrum on $\mathbb{P}^1$

abstract:
  Motivated by the work of Abreu and Freitas, we study the invariant spectrum
of the Laplace operator associated to hermitian line bundles endowed with
invariant metrics over $\mathbb{p}^1$.


title: On new maximal supergravity and its BPS domain-walls

abstract:
  We revise the SU(3)-invariant sector of $\mathcal{N}=8$ supergravity with
dyonic SO(8) gaugings. By using the embedding tensor formalism, analytic
expressions for the scalar potential, superpotential(s) and fermion mass terms
are obtained as a function of the electromagnetic phase $\omega$ and the
scalars in the theory. Equipped with these results, we explore
non-supersymmetric AdS critical points at $\omega \neq 0$ for which
perturbative stability could not be analysed before. The $\omega$-dependent
superpotential is then used to derive first-order flow equations and obtain new
BPS domain-wall solutions at $\omega \neq 0$. We numerically look at
steepest-descent paths motivated by the (conjectured) RG flows.


title:
Consequences of Symmetries and Consistency Relations in the Large-Scale
  Structure of the Universe for Non-local bias and Modified Gravity

abstract:
  Consistency relations involving the soft limit of the (n + 1)-correlator
functions of dark matter and galaxy overdensities can be obtained, both in real
and redshift space, thanks to the symmetries enjoyed by the Newtonian equations
of motion describing the dark matter and galaxy fluids coupled through gravity.
We study the implications of such symmetries for the theory of galaxy bias and
for the theories of modified gravity. We find that the invariance of the fluid
equations under a coordinate transformation that induces a long-wavelength
velocity constrain the bias to depend only on a set of invariants, while the
symmetry of such equations under Lifshitz scalings in the case of matter
domination allows one to compute the time-dependence of the coefficients in the
bias expansion. We also find that in theories of modified gravity which violate
the equivalence principle induce a violation of the consistency relation which
may be a signature for their observation. Thus, given adiabatic Gaussian
initial conditions, the observation of a deviation from the consistency
relation for galaxies would signal a break-down of the so-called non-local
Eulerian bias model or the violation of the equivalence principle in the
underlying theory of gravity.


title: On the Distributed Construction of a Collision-Free Schedule in WLANs

abstract:
  In wireless local area networks (WLANs), a media access protocol arbitrates
access to the channel. In current IEEE 802.11 WLANs, carrier sense multiple
access with collision avoidance (CSMA/CA) is used. Carrier sense multiple
access with enhanced collision avoidance (CSMA/ECA) is a subtle variant of the
well-known CSMA/CA algorithm that offers substantial performance benefits.
CSMA/ECA significantly reduces the collision probability and, under certain
conditions, leads to a completely collision-free schedule. The only difference
between CSMA/CA and CSMA/ECA is that the latter uses a deterministic backoff
after successful transmissions. This deterministic backoff is a constant and is
the same for all the stations.
  The first part of the paper is of tutorial nature, offering an introduction
to the basic operation of CSMA/ECA and describing the benefits of this approach
in a qualitative manner. The second part of the paper surveys related
contributions, briefly summarizing the main challenges and potential solutions,
and also introducing variants and derivatives of CSMA/ECA.


title:
Low X-Ray Luminosity Galaxy Clusters. II. Optical properties and
  morphological content at 0.18 < z < 0.70

abstract:
  This is the second of a series of papers on low X-ray luminosity galaxy
clusters, in which we present the $r^\prime$, $g^\prime$ and $i^\prime$
photometry obtained with GMOS-IMAGE at Gemini North and South telescopes for
seven systems in the redshift range of 0.18 to 0.70. Optical magnitudes,
colours and morphological parameters, namely, concentration index, ellipticity
and visual morphological classification, are also given.
  At lower redshifts, the presence of a well-defined red cluster sequence
extending by more than 4 magnitudes showed that these intermediate-mass
clusters had reached a relaxed stage. This was confirmed by the small fraction
of blue galaxy members observed in the central regions of $\sim$ 0.75 Mpc.
  In contrast, galaxy clusters at higher redshifts had a less important red
cluster sequence. We also found that the galaxy radial density profiles in
these clusters were well fitted by a single power law.
  At 0.18 $<$ z $<$ 0.70, we observed an increasing fraction of blue galaxies
and a decreasing fraction of lenticulars, with the early-type fraction
remaining almost constant. Overall, the results of these intermediate-mass
clusters are in agreement with those for high mass clusters.


title:
Rank Properties of Multiplicative Semigroup Reduct of Affine
  Near-Semirings over $B_n$

abstract:
  This work investigates the rank properties of $A^+(B_n)$, the multiplicative
semigroup reduct of the affine near-semirings over an aperiodic Brandt
semigroup $B_n$. In this connection, the work obtains the small rank, lower
rank and large rank of $A^+(B_n)$. Further, the work provides lower bounds for
intermediate rank and upper rank of $A^+(B_n)$.


title:
A Discontinuous Galerkin Time Domain Framework for Periodic Structures
  Subject To Oblique Excitation

abstract:
  A nodal Discontinuous Galerkin (DG) method is derived for the analysis of
time-domain (TD) scattering from doubly periodic PEC/dielectric structures
under oblique interrogation. Field transformations are employed to elaborate a
formalism that is free from any issues with causality that are common when
applying spatial periodic boundary conditions simultaneously with incident
fields at arbitrary angles of incidence. An upwind numerical flux is derived
for the transformed variables, which retains the same form as it does in the
original Maxwell problem for domains without explicitly imposed periodicity.
This, in conjunction with the amenability of the DG framework to non-conformal
meshes, provides a natural means of accurately solving the first order TD
Maxwell equations for a number of periodic systems of engineering interest.
Results are presented that substantiate the accuracy and utility of our method.


title: Engineering nonlinear response of nanomaterials using Fano resonances

abstract:
  We show that, nonlinear optical processes of nanoparticles can be controlled
by the presence of interactions with a molecule or a quantum dot. By choosing
the appropriate level spacing for the quantum emitter, one can either suppress
or enhance the nonlinear frequency conversion. We reveal the underlying
mechanism for this effect, which is already observed in recent experiments: (i)
Suppression occurs simply because transparency induced by Fano resonance does
not allow an excitation at the converted frequency. (ii) Enhancement emerges
since nonlinear process can be brought to resonance. Path interference effect
cancels the nonresonant frequency terms. We demonstrate the underlying physics
using a simplified model, and we show that the predictions of the model are in
good agreement with the 3-dimensional boundary element method (MNPBEM toolbox)
simulations. Here, we consider the second harmonic generation in a plasmonic
converter as an example to demonstrate the control mechanism. The phenomenon is
the semi-classical analog of nonlinearity enhancement via electromagnetically
induced transparency.


title:
Lie-Hamilton systems on the plane: properties, classification and
  applications

abstract:
  We study Lie-Hamilton systems on the plane, i.e. systems of first-order
differential equations describing the integral curves of a $t$-dependent vector
field taking values in a finite-dimensional real Lie algebra of planar
Hamiltonian vector fields with respect to a Poisson structure. We start with
the local classification of finite-dimensional real Lie algebras of vector
fields on the plane obtained in [A. Gonz\'alez-L\'opez, N. Kamran and P.J.
Olver, Proc. London Math. Soc. 64, 339 (1992)] and we interpret their results
as a local classification of Lie systems. Moreover, by determining which of
these real Lie algebras consist of Hamiltonian vector fields with respect to a
Poisson structure, we provide the complete local classification of Lie-Hamilton
systems on the plane. We present and study through our results new Lie-Hamilton
systems of interest which are used to investigate relevant non-autonomous
differential equations, e.g. we get explicit local diffeomorphisms between such
systems. In particular, the Milne-Pinney, second-order Kummer-Schwarz, complex
Riccati and Buchdahl equations as well as some Lotka-Volterra and nonlinear
biomathematical models are analysed from this Lie-Hamilton approach.


title: Topological freeness for $*$-commuting covering maps

abstract:
  A countable family of $*$-commuting surjective, non-injective local
homeomorphisms of a compact Hausdorff space $X$ gives rise to an action
$\theta$ of a countably generated, free abelian monoid $P$. For such a triple
$(X,P,\theta)$, which we call an irreversible $*$-commutative dynamical system,
we construct a universal $C^*$-algebra $\mathcal{O}[X,P,\theta]$. Within this
setting we show that the following four conditions are equivalent:
$(X,P,\theta)$ is topologically free, $C(X) \subset \mathcal{O}[X,P,\theta]$
has the ideal intersection property, the natural representation of
$\mathcal{O}[X,P,\theta]$ on $\ell^2(X)$ is faithful, and $C(X)$ is a masa in
$\mathcal{O}[X,P,\theta]$. As an application, we characterise simplicity of
$\mathcal{O}[X,P,\theta]$ by minimality of $(X,P,\theta)$. We also show that
$\mathcal{O}[X,P,\theta]$ is isomorphic to the Cuntz-Nica-Pimsner algebra of a
product system of Hilbert bimodules naturally associated to $(X,P,\theta)$.
Moreover, we find a close connection between $*$-commutativity and independence
of group endomorphisms, a notion introduced by Cuntz and Vershik. This leads to
the observation that, for commutative irreversible algebraic dynamical systems
of finite type $(G,P,\theta)$, the dual model $(\hat{G},P,\hat{\theta})$ is an
irreversible $*$-commutative dynamical system and
$\mathcal{O}[\hat{G},P,\hat{\theta}]$ is canonically isomorphic to
$\mathcal{O}[G,P,\theta]$. This allows us to conclude that minimality of
$(G,P,\theta)$ is not only sufficient, but also necessary for simplicity of
$\mathcal{O}[G,P,\theta]$ if $(G,P,\theta)$ is commutative and of finite type.


title:
Perturbed vortex lattices and the stability of nucleated topological
  phases

abstract:
  We study the stability of nucleated topological phases that can emerge when
interacting non-Abelian anyons form a regular array. The studies are carried
out in the context of Kitaev's honeycomb model, where we consider three
distinct types of perturbations in the presence of a lattice of Majorana mode
binding vortices -- spatial anisotropy of the vortices, dimerization of the
vortex lattice and local random disorder. While all the nucleated phases are
stable with respect to weak perturbations of each kind, strong perturbations
are found to result in very different behavior. Anisotropy of the vortices
stabilizes the strong-pairing like phases, while dimerization can recover the
underlying non-Abelian phase. Local random disorder, on the other hand, can
drive all the nucleated phases into a gapless thermal metal state. We show that
all these distinct behavior can be captured by an effective staggered
tight-binding model for the Majorana modes. By studying the pairwise
interactions between the vortices, i.e. the amplitudes for the Majorana modes
to tunnel between vortex cores, the locations of phase transitions and the
nature of the resulting states can be predicted. We also find that due to
oscillations in the Majorana tunneling amplitude, lattices of Majorana modes
may exhibit a Peierls-like instability, where a dimerized configuration is
favored over a uniform lattice. As the nature of the nucleated phases depends
only on the Majorana tunneling, our results apply also to other system
supporting localized Majorana mode arrays, such as Abrikosov lattices in p-wave
superconductors, Wigner crystals in Moore-Read fractional quantum Hall states
or arrays of topological nanowires.


title:
Regularity for anisotropic fully nonlinear integro-differential
  equations

abstract:
  We consider fully nonlinear integro-differential equations governed by
kernels that have different homogeneities in different directions. We prove a
nonlocal version of the ABP estimate, a Harnack inequality and the interior
$C^{1, \gamma}$ regularity, extending the results of [Caffarelli and Silvestre,
CPAM 62, 2009] to the anisotropic case.


title: A note on H_infinity structures

abstract:
  We give a source of examples of H_infinity ring structures that do not lift
to E_infinity ring structures, based on Mandell's equivalence between certain
cochain algebras and spaces.


title:
Identification of new Galactic symbiotic stars with SALT. I. Initial
  discoveries and other emission line objects

abstract:
  We introduce the first results from an ongoing, systematic survey for new
symbiotic stars selected from the AAO/UKST SuperCOSMOS H$\alpha$ Survey (SHS).
The survey aims to identify and characterise the fainter population of
symbiotic stars underrepresented in extant catalogues. The accreting white
dwarfs (WDs) in symbiotic stars, fuelled by their red giant donors with high
mass loss rate winds, make them promising candidates for type Ia supernovae.
Several candidates were observed spectroscopically with the Southern African
Large Telescope (SALT). A total of 12 bona-fide and 3 possible symbiotic stars
were identified. The most remarkable example is a rare carbon-rich symbiotic
star that displays coronal [Fe X] $\lambda$6375 emission, suggesting it may be
a supersoft X-ray source with a massive WD. Several other emission line objects
with near-infrared colours similar to symbiotic stars are listed in an
appendix, including 6 B[e] stars, 4 planetary nebulae (PNe), 2 possible Be
stars, one [WC9] Wolf-Rayet (WR) central star of a PN and one WC9 WR star.
These initial discoveries will help shape and refine the candidate selection
criteria that we expect will uncover several more symbiotic stars as the survey
progresses.


title:
Fast Self-Stabilizing Minimum Spanning Tree Construction Using Compact
  Nearest Common Ancestor Labeling Scheme

abstract:
  We present a novel self-stabilizing algorithm for minimum spanning tree (MST)
construction. The space complexity of our solution is $O(\log^2n)$ bits and it
converges in $O(n^2)$ rounds. Thus, this algorithm improves the convergence
time of previously known self-stabilizing asynchronous MST algorithms by a
multiplicative factor $\Theta(n)$, to the price of increasing the best known
space complexity by a factor $O(\log n)$. The main ingredient used in our
algorithm is the design, for the first time in self-stabilizing settings, of a
labeling scheme for computing the nearest common ancestor with only
$O(\log^2n)$ bits.


title: Kicked Dirac particle in a box

abstract:
  We study quantum dynamics of a kicked relativistic spin-half particle in a
one dimensional box. Time-dependence of the average kinetic energy and
evolution of the wave packet are explored. Kicking potential is introduced as
the Lorentz-scalar, i.e., through the mass-term in the Dirac equation. It is
found that depending on the values of the kicking parameters E(t) can be
periodic, monotonically growing and non-periodic function of time. Particle
transport in the system is studied by considering spatio-temporal evolution of
the Gaussian wave packet.Splitting of the packet into two symmetric parts and
restoration of the profile of the packet is found.

categories: quant-ph cond-mat.mes-hall math-ph math.MP nlin.CD


title: Distributed Exploration in Multi-Armed Bandits

abstract:
  We study exploration in Multi-Armed Bandits in a setting where $k$ players
collaborate in order to identify an $\epsilon$-optimal arm. Our motivation
comes from recent employment of bandit algorithms in computationally intensive,
large-scale applications. Our results demonstrate a non-trivial tradeoff
between the number of arm pulls required by each of the players, and the amount
of communication between them. In particular, our main result shows that by
allowing the $k$ players to communicate only once, they are able to learn
$\sqrt{k}$ times faster than a single player. That is, distributing learning to
$k$ players gives rise to a factor $\sqrt{k}$ parallel speed-up. We complement
this result with a lower bound showing this is in general the best possible. On
the other extreme, we present an algorithm that achieves the ideal factor $k$
speed-up in learning performance, with communication only logarithmic in
$1/\epsilon$.


title:
Using Surface-Motions for Locomotion of Microscopic Robots in Viscous
  Fluids

abstract:
  Microscopic robots could perform tasks with high spatial precision, such as
acting in biological tissues on the scale of individual cells, provided they
can reach precise locations. This paper evaluates the feasibility of in vivo
locomotion for micron-size robots. Two appealing methods rely only on surface
motions: steady tangential motion and small amplitude oscillations. These
methods contrast with common microorganism propulsion based on flagella or
cilia, which are more likely to damage nearby cells if used by robots made of
stiff materials. The power potentially available to robots in tissue supports
speeds ranging from one to hundreds of microns per second, over the range of
viscosities found in biological tissue. We discuss design trade-offs among
propulsion method, speed, power, shear forces and robot shape, and relate those
choices to robot task requirements. This study shows that realizing such
locomotion requires substantial improvements in fabrication capabilities and
material properties over current technology.


title:
Molecular responses of mouse macrophages to copper and copper oxide
  nanoparticles inferred from proteomic analyses

abstract:
  The molecular responses of macrophages to copper-based nanoparticles have
been investigated via a combination of proteomic and biochemical approaches,
using the RAW264.7 cell line as a model. Both metallic copper and copper oxide
nanoparticles have been tested, with copper ion and zirconium oxide
nanoparticles used as controls. Proteomic analysis highlighted changes in
proteins implicated in oxidative stress responses (superoxide dismutases and
peroxiredoxins), glutathione biosynthesis, the actomyosin cytoskeleton, and
mitochondrial proteins (especially oxidative phosphorylation complex subunits).
Validation studies employing functional analyses showed that the increases in
glutathione biosynthesis and in mitochondrial complexes observed in the
proteomic screen were critical to cell survival upon stress with copper-based
nanoparticles; pharmacological inhibition of these two pathways enhanced cell
vulnerability to copper-based nanoparticles, but not to copper ions.
Furthermore, functional analyses using primary macrophages derived from bone
marrow showed a decrease in reduced glutathione levels, a decrease in the
mitochondrial transmembrane potential, and inhibition of phagocytosis and of
lipopolysaccharide-induced nitric oxide production. However, only a fraction of
these effects could be obtained with copper ions. In conclusion, this study
showed that macrophage functions are significantly altered by copper-based
nanoparticles. Also highlighted are the cellular pathways modulated by cells
for survival and the exemplified cross-toxicities that can occur between
copper-based nanoparticles and pharmacological agents.


title: When "I cut, you choose" method implies intransitivity

abstract:
  There is a common belief that humans and many animals follow transitive
inference (choosing A over C on the basis of knowing that A is better than B
and B is better than C). Transitivity seems to be the essence of rational
choice. We present a theoretical model of a repeated game in which the players
make a choice between three goods (e.g. food). The rules of the game refer to
the simple procedure of fair division among two players, known as the "I cut,
you choose" mechanism which has been widely discussed in the literature. In
this game one of the players has to make intransitive choices in order to
achieve the optimal result (for him/her and his/her co-player). The point is
that an intransitive choice can be rational. Previously, an increase in the
significance of intransitive strategies was achieved by referring to models of
quantum games. We show that \textit{relevant intransitive strategies} also
appear in the classic description of decision algorithms.


title: Innovation \'educative en sciences de l'information

abstract:
  Concerning its development in the virtual classroom, the web 2.0 educational
innovation means the use and the production of textbooks and the
personalisation of the classnotes. The controversy, that is a precondition of
awareness, organized around the assignment of knowledge to a central authority
vs its grant to individuals who need it to share their plans with others, would
meet the present dynamism of e-learning. To introduce these training strategies
with scientific information in marine sciences, an online course was
transformed into an opportunity for evaluating and living open access.


title:
On the inequality of the 3V's of Big Data Architectural Paradigms: A
  case for heterogeneity

abstract:
  The well-known 3V architectural paradigm for Big Data introduced by Laney
(2011), provides a simplified framework for defining the architecture of a big
data platform to be deployed in various scenarios tackling processing of
massive datasets. While additional components such as Variability and Veracity
have been discussed as an extension to the 3V model, the basic components
(volume, variety, velocity) provide a quantitative framework while variability
and veracity target a more qualitative approach. In this paper we argue why the
basic 3V's are not equal due to the different requirements that need to be
covered in case higher demands for a particular "V". Similar to other
conjectures such as the CAP theorem 3V based architectures differ on their
implementation. We call this paradigm heterogeneity and we provide a taxonomy
of the existing tools (as of 2013) covering the Hadoop ecosystem from the
perspective of heterogeneity. This paper contributes on the understanding of
the Hadoop ecosystem from the perspective of different workloads and aims to
help researchers and practitioners on the design of scalable platforms
targeting different operational needs.


title:
Initial validation of a virtual-reality learning environment for
  prostate biopsies: realism matters!

abstract:
  : Introduction-objectives: A virtual-reality learning environment dedicated
to prostate biopsies was designed to overcome the limitations of current
classical teaching methods. The aim of this study was to validate reliability,
face, content and construct of the simulator. Materials and methods: The
simulator is composed of a) a laptop computer, b) a haptic device with a stylus
that mimics the ultrasound probe, c) a clinical case database including three
dimensional (3D) ultrasound volumes and patient data and d) a learning
environment with a set of progressive exercises including a randomized 12-core
biopsy procedure. Both visual (3D biopsy mapping) and numerical (score)
feedback are given to the user. The simulator evaluation was conducted in an
academic urology department on 7 experts and 14 novices who each performed a
virtual biopsy procedure and completed a face and content validity
questionnaire. Results: The overall realism of the biopsy procedure was rated
at a median of 9/10 by non-experts (7.1-9.8). Experts rated the usefulness of
the simulator for the initial training of urologists at 8.2/10 (7.9-8.3), but
reported the range of motion and force feedback as significantly less realistic
than novices (p=0.01 and 0.03 respectively). Pearson's r correlation
coefficient between correctly placed biopsies on the right and left side of the
prostate for each user was 0.79 (p<0.001). The 7 experts had a median score of
64% (59-73), and the 14 novices a median score of 52% (43-67), without reaching
statistical significance (p=0,19). Conclusion: The newly designed virtual
reality learning environment proved its versatility and its reliability, face
and content were validated. Demonstrating the construct validity will require
improvements to the realism and scoring system used.


title:
Delineating the magnetic field line escape pattern and stickiness in a
  poloidally diverted tokamak

abstract:
  We analyze a Hamiltonian model with five wire loops that delineates the
magnetic surfaces of the tokamak ITER, including a similar safety factor
profile and the X-point related to the presence of a poloidal divertor.
Non-axisymmetric magnetic perturbations are added by external coils, similar to
the correction coils installed at the tokamak DIII-D and those that will be
installed at ITER. To show the influence of magnetic perturbations on the field
line escape, we integrate numerically the field line differential equations and
obtain the footprints and deposition patterns on the divertor plate. Moreover,
we show that the homoclinic tangle describes the deposition patterns in the
divertor plate, agreeing with results observed in sophisticated simulation
codes. Additionally, we show that while chaotic lines escape to the divertor
plates, some of them are trapped, for many toroidal turns, in complex
structures around magnetic islands, embedded in the chaotic region, giving rise
to the so called stickiness effect characteristic of chaotic Hamiltonian
systems. Finally, we introduce a random collisional term to the field line
mapping to investigate stickiness alterations due to particle collisions.
Within this model, we conclude that, even reduced by collisions, stickiness
still influences the field line transport.


title: Magnetic Field Line Stickiness in Tokamaks

abstract:
  We present simulated figures of the diverted magnetic field lines of the
tokamak ITER, obtained by numerically integrating a Hamiltonian model with
electrical currents in five wire loops and control coils. We show evidences of
a sticky island embedded in the chaotic region near the divertor plates, which
traps magnetic field lines for many toroidal turns increasing their connection
lengths to these plates.


title:
Stability Analysis and Classification of Runge-Kutta Methods for Index 1
  Stochastic Differential-Algebraic Equations with Scalar Noise

abstract:
  The problem of solving stochastic differential-algebraic equations (SDAEs) of
index one with a scalar driving Brownian motion is considered. Recently, the
authors proposed a class of stiffly accurate stochastic Runge-Kutta (SRK)
methods that do not involve any pseudo-inverses or projectors for the numerical
solution of the problem. Based on this class of approximation methods, a
classification for the coefficients of stiffly accurate SRK methods attaining
strong order 0.5 as well as strong order 1.0 are calculated. Further, the
mean-square stability for the considered class of SRK methods is analysed. As
the main result, families of A-stable efficient order 0.5 and 1.0 stiffly
accurate SRK methods with a minimal number of stages for SDEs as well as for
SDAEs are presented.


title: On the emergence of an "intention field" for socially cohesive agents

abstract:
  We argue that when a social convergence mechanism exists and is strong
enough, one should expect the emergence of a well defined "field", i.e. a
slowly evolving, local quantity around which individual attributes fluctuate in
a finite range. This condensation phenomenon is well illustrated by the
Deffuant-Weisbuch opinion model for which we provide a natural extension to
allow for spatial heterogeneities. We show analytically and numerically that
the resulting dynamics of the emergent field is a noisy diffusion equation that
has a slow dynamics. This random diffusion equation reproduces the long-ranged,
logarithmic decrease of the correlation of spatial voting patterns empirically
found in [1, 2]. Interestingly enough, we find that when the social cohesion
mechanism becomes too weak, cultural cohesion breaks down completely, in the
sense that the distribution of intentions/opinions becomes infinitely broad. No
emerging field exists in this case. All these analytical findings are confirmed
by numerical simulations of an agent-based model.


title: Oracle Inequalities for High Dimensional Vector Autoregressions

abstract:
  This paper establishes non-asymptotic oracle inequalities for the prediction
error and estimation accuracy of the LASSO in stationary vector autoregressive
models. These inequalities are used to establish consistency of the LASSO even
when the number of parameters is of a much larger order of magnitude than the
sample size. We also give conditions under which no relevant variables are
excluded.
  Next, non-asymptotic probabilities are given for the Adaptive LASSO to select
the correct sparsity pattern. We then give conditions under which the Adaptive
LASSO reveals the correct sparsity pattern asymptotically. We establish that
the estimates of the non-zero coefficients are asymptotically equivalent to the
oracle assisted least squares estimator. This is used to show that the rate of
convergence of the estimates of the non-zero coefficients is identical to the
one of least squares only including the relevant covariates.


title:
Fermi surface in the hidden-order state of URu$_2$Si$_2$ under intense
  pulsed magnetic fields up to 81~T

abstract:
  We present measurements of the resistivity $\rho_{x,x}$ of URu2Si2
high-quality single crystals in pulsed high magnetic fields up to 81~T at a
temperature of 1.4~K and up to 60~T at temperatures down to 100~mK. For a field
\textbf{H} applied along the magnetic easy-axis \textbf{c}, a strong
sample-dependence of the low-temperature resistivity in the hidden-order phase
is attributed to a high carrier mobility. The interplay between the magnetic
and orbital properties is emphasized by the angle-dependence of the phase
diagram, where magnetic transition fields and crossover fields related to the
Fermi surface properties follow a 1/$\cos\theta$-law, $\theta$ being the angle
between \textbf{H} and \textbf{c}. For $\mathbf{H}\parallel\mathbf{c}$, a
crossover defined at a kink of $\rho_{x,x}$, as initially reported in [Shishido
et al., Phys. Rev. Lett. \textbf{102}, 156403 (2009)], is found to be strongly
sample-dependent: its characteristic field $\mu_0H^*$ varies from $\simeq20$~T
in our best sample with a residual resistivity ratio RRR of $225$ to
$\simeq25$~T in a sample with a RRR of $90$. A second crossover is defined at
the maximum of $\rho_{x,x}$ at the sample-independent characteristic field
$\mu_0H_{\rho,max}^{LT}\simeq30$~T. Fourier analyzes of SdH oscillations show
that $H_{\rho,max}^{LT}$ coincides with a sudden modification of the Fermi
surface, while $H^*$ lies in a regime where the Fermi surface is smoothly
modified. For $\mathbf{H}\parallel\mathbf{a}$, i) no phase transition is
observed at low temperature and the system remains in the hidden-order phase up
to 81~T, ii) quantum oscillations surviving up to 7~K are related to a new and
almost-spherical orbit - for the first time observed here - at the frequency
$F_\lambda\simeq1400$~T and associated with a low effective mass
$m^*_\lambda=(1\pm0.5)\cdot m_0$, and iii) no Fermi surface modification occurs
up to 81~T.


title: Quantropy

abstract:
  There is a well-known analogy between statistical and quantum mechanics. In
statistical mechanics, Boltzmann realized that the probability for a system in
thermal equilibrium to occupy a given state is proportional to exp(-E/kT) where
E is the energy of that state. In quantum mechanics, Feynman realized that the
amplitude for a system to undergo a given history is proportional to exp(-S/i
hbar) where S is the action of that history. In statistical mechanics we can
recover Boltzmann's formula by maximizing entropy subject to a constraint on
the expected energy. This raises the question: what is the quantum mechanical
analogue of entropy? We give a formula for this quantity, which we call
"quantropy". We recover Feynman's formula from assuming that histories have
complex amplitudes, that these amplitudes sum to one, and that the amplitudes
give a stationary point of quantropy subject to a constraint on the expected
action. Alternatively, we can assume the amplitudes sum to one and that they
give a stationary point of a quantity we call "free action", which is analogous
to free energy in statistical mechanics. We compute the quantropy, expected
action and free action for a free particle, and draw some conclusions from the
results.


title: The foundation axiom and elementary self-embeddings of the universe

abstract:
  We consider the role of the foundation axiom and various anti-foundation
axioms in connection with the nature and existence of elementary
self-embeddings of the set-theoretic universe.


title:
Geonic black holes and remnants in Eddington-inspired Born-Infeld
  gravity

abstract:
  We show that electrically charged solutions within the Eddington-inspired
Born-Infeld theory of gravity replace the central singularity by a wormhole
supported by the electric field. As a result, the total energy associated with
the electric field is finite and similar to that found in the Born-Infeld
electromagnetic theory. When a certain charge-to-mass ratio is satisfied, in
the lowest part of the mass and charge spectrum the event horizon disappears
yielding stable remnants. We argue that quantum effects in the matter sector
can lower the mass of these remnants from the Planck scale down to the TeV
scale.


title: On Leonardo da Vinci's proof of the Theorem of Pythagoras

abstract:
  We show that Leonardo da Vinci's well known proof of the Pythagorean theorem
is due to Mayer and not to da Vinci.


title: On curves and polygons with the equiangular chord property

abstract:
  Let $C$ be a smooth, convex curve on either the sphere $\mathbb{S}^{2}$, the
hyperbolic plane $\mathbb{H}^{2}$ or the Euclidean plane $\mathbb{E}^{2}$, with
the following property: there exists $\alpha$, and parameterizations $x(t),
y(t)$ of $C$ such that for each $t$, the angle between the chord connecting
$x(t)$ to $y(t)$ and $C$ is $\alpha$ at both ends.
  Assuming that $C$ is not a circle, E. Gutkin completely characterized the
angles $\alpha$ for which such a curve exists in the Euclidean case. We study
the infinitesimal version of this problem in the context of the other two
constant curvature geometries, and in particular we provide a complete
characterization of the angles $\alpha$ for which there exists a non-trivial
infinitesimal deformation of a circle through such curves with corresponding
angle $\alpha$. We also consider a discrete version of this property for
Euclidean polygons, and in this case we give a complete description of all
non-trivial solutions.


title:
On the role of AGN feedback on the thermal and chemodynamical properties
  of the hot intra-cluster medium

abstract:
  We present an analysis of the properties of the ICM in an extended set of
cosmological hydrodynamical simulations of galaxy clusters and groups performed
with the TreePM+SPH GADGET-3 code. Besides a set of non-radiative simulations,
we carried out two sets of simulations including radiative cooling, star
formation, metal enrichment and feedback from supernovae, one of which also
accounts for the effect of feedback from AGN resulting from gas accretion onto
super-massive black holes. These simulations are analysed with the aim of
studying the relative role played by SN and AGN feedback on the general
properties of the diffuse hot baryons in galaxy clusters and groups: scaling
relations, temperature, entropy and pressure radial profiles, and ICM chemical
enrichment. We find that simulations including AGN feedback produce scaling
relations that are in good agreement with X-ray observations at all mass
scales. However, our simulations are not able to account for the observed
diversity between CC and NCC clusters: unlike for observations, we find that
temperature and entropy profiles of relaxed and unrelaxed clusters are quite
similar and resemble more the observed behaviour of NCC clusters. As for the
pattern of metal enrichment, we find that an enhanced level of iron abundance
is produced by AGN feedback with respect to the case of purely SN feedback. As
a result, while simulations including AGN produce values of iron abundance in
groups in agreement with observations, they over-enrich the ICM in massive
clusters. The efficiency of AGN feedback in displacing enriched gas from halos
into the inter-galactic medium at high redshift also creates a widespread
enrichment in the outskirts of clusters and produces profiles of iron abundance
whose slope is in better agreement with observations.


title:
Phoneme discrimination using neurons with symmetric nonlinear response
  over a spectral range

abstract:
  We consider the ability of a very simple feed-forward neural network to
discriminate phonemes based on just relative power spectrum. The network
consists of two neurons with symmetric nonlinear response over a spectral
range. The output of the neurons is subsequently fed to a comparator. We show
that often this is enough to achieve complete separation of data. We compare
the performance of found discriminants with that of more general neurons. Our
conclusion is that not much is gained in passing to real-valued weights. More
likely higher number of neurons and preprocessing of input will yield better
discrimination results. The networks considered are directly amenable to
hardware (neuromorphic) designs. Other advantages include interpretability,
guarantees of performance on unseen data and low Kolmogorov complexity.


title: Polynomial representations of GL(n) and Schur-Weyl duality

abstract:
  Polynomial representations of general linear groups and modules over Schur
algebras are compared. We work over an arbitrary commutative ring and show that
Schur-Weyl duality is the key for an equivalence between both categories.


title:
Enzymatic AND Logic Gate with Sigmoid Response Induced by
  Photochemically Controlled Oxidation of the Output

abstract:
  We report a study of a system which involves an enzymatic cascade realizing
an AND logic gate, with an added photochemical processing of the output
allowing to make the gate's response sigmoid in both inputs. New functional
forms are developed for quantifying the kinetics of such systems, specifically
designed to model their response in terms of signal and information processing.
These theoretical expressions are tested for the studied system, which also
allows us to consider aspects of biochemical information processing such as
noise transmission properties and control of timing of the chemical and
physical steps.


title: Properties of maximum Lempel-Ziv complexity strings

abstract:
  The properties of maximum Lempel-Ziv complexity strings are studied for the
binary case. A comparison between MLZs and random strings is carried out. The
length profile of both type of sequences show different distribution functions.
The non-stationary character of the MLZs are discussed. The issue of
sensitiveness to noise is also addressed. An empirical ansatz is found that
fits well to the Lempel-Ziv complexity of the MLZs for all lengths up to $10^6$
symbols.


title:
Influence of lithium doping on the thermodynamic properties of graphene
  based superconductors

abstract:
  It has been recently observed that the conventional electron-phonon mediated
superconducting phase in graphene can be easily induced by doping its surface
with the lihitum adatoms. Due to the emerging interest in this field of
research we present our theoretical discussion of the thermodynamic properties
of this novel structures within the strong-coupling limit. We show, that
together with the increase of the adatom doping, from one (LiC$_{6}$) to two
(Li$_{2}$C$_{6}$) lithium atoms per unit cell, the critical temperature ($T_C$)
changes from 8.55 K to 21.83 K. Such trend is also observed for other
thermodynamic properties which moreover differ from the predictions of the
Bardeen-Cooper-Schrieffer theory. In particular, the zero-temperature energy
gap to the critical temperature ratio: R$_{\Delta}^{{\rm LiC}_6}$=3.72 and
R$_{\Delta}^{{\rm Li}_{2}{\rm C}_6}$=4.21; the ratio of the specific heat for
superconducting and the normal state: R$_{\rm C}^{{\rm LiC}_6}$=1.47 and
R$_{\rm C}^{{\rm Li}_{2}{\rm C}_6}$=1.79; and the parameter connected with the
zero-temperature thermodynamic critical field: R$_{\rm H}^{{\rm LiC}_6}$=0.167
and R$_{\rm H}^{{\rm Li}_{2}{\rm C}_6}$=0.144. Finally the electron effective
mass at $T_c$ is calculated to be: $(1.62m_e)_{{\rm LiC}_6}$ and
$(2.48m_e)_{{\rm Li}_{2}{\rm C}_6}$.


title: A numerical model for the trans-membrane voltage of vesicles

abstract:
  The Immersed Interface Method is employed to solve the time-varying electric
field equations around a three-dimensional vesicle. To achieve second-order
accuracy the implicit jump conditions for the electric potential, up to the
second normal derivative, are derived. The trans-membrane potential is
determined implicitly as part of the algorithm. The method is compared to an
analytic solution based on spherical harmonics and verifies the second-order
accuracy of the underlying discretization even in the presence of solution
discontinuities. A sample result for an elliptic interface is also presented.


title:
Unconditional Security of Time-energy Entanglement Quantum Key
  Distribution using Dual-basis Interferometry

abstract:
  High-dimensional quantum key distribution (HDQKD) offers the possibility of
high secure-key rate with high photon-information efficiency. We consider HDQKD
based on the time-energy entanglement produced by spontaneous parametric
downconversion, and show that it is secure against collective attacks. Its
security rests upon visibility data -- obtained from Franson and
conjugate-Franson interferometers -- that probe photon-pair frequency
correlations and arrival-time correlations. From these measurements an upper
bound can be established on the eavesdropper's Holevo information by
translating the Gaussian-state security analysis for continuous-variable
quantum key distribution so that it applies to our protocol. We show that
visibility data from just the Franson interferometer provides a weaker, but
nonetheless useful, secure-key rate lower bound. To handle multiple-pair
emissions, we incorporate the decoy-state approach into our protocol. Our
results show that over 200\,km transmission distance in optical fiber,
time-energy entanglement HDQKD could permit a 700 bit/sec secure-key rate, and
a photon information efficiency of 2 secure-key bits per photon coincidence in
the key-generation phase using receivers with 15% system efficiency.


title:
Characterizing the Dust Coma of Comet C/2012 S1 (ISON) at 4.15 AU from
  the Sun

abstract:
  We report results from broadband visible images of comet C/2012 S1 (ISON)
obtained with the Hubble Space Telescope Wide Field Camera 3 on 2013 April 10.
C/ISON's coma brightness follows a 1/{\rho} (where {\rho} is the projected
distance from the nucleus) profile out to 5000 km, consistent with a constant
speed dust outflow model. The turnaround distance in the sunward direction
suggests that the dust coma is composed of sub-micron-sized particles emitted
at speeds of tens of meters s$^{-1}$. A({\theta})f{\rho}, which is commonly
used to characterize the dust production rate, was 1340 and 1240 cm in the
F606W and F438W filters, respectively, in apertures <1.6" in radius. The dust
colors are slightly redder than solar, with a slope of 5.0$\pm$0.2% per 100 nm,
increasing to >10% per 100 nm 10,000 km down the tail. The colors are similar
to those of comet C/1995 O1 (Hale-Bopp) and other long-period comets, but
somewhat bluer than typical values for short-period comets. The spatial color
variations are also reminiscent of C/Hale-Bopp. A sunward jet is visible in
enhanced images, curving to the north and then tailward in the outer coma. The
1.6"-long jet is centered at a position angle of 291$^\circ$, with an opening
angle of about 45$^\circ$. The jet morphology remains unchanged over 19 hours
of our observations, suggesting that it is near the rotational pole of the
nucleus, and implying that the pole points to within 30 deg of (RA, Dec) =
(330$^\circ$, 0$^\circ$). This pole orientation indicates a high obliquity of
50$^\circ$-80$^\circ$.


title: Prediction of Neutrino Mixing based on $C_2\times D_3$

abstract:
  The lepton mixing angles of the PMNS matrix are predicted based on the lepton
flavor symmetry of a finite group $C_2\times D_3$, where the cyclic group $C_2$
acts on the charged lepton mass terms and the dihedral group $D_3$ on the
neutrino ones. All three mixing angles of the PMNS matrix are given in terms of
just one parameter, the charged lepton mixing angle, and fit extremely well to
the observed values. In particular, the smallness of $\theta_{13}$ is explained
in terms of the smallness of the muon-to-tau mass ratio.


title: Estimating Uncertainties in Statistics Computed from DNS

abstract:
  Rigorous assessment of uncertainty is crucial to the utility of DNS results.
Uncertainties in the computed statistics arise from two sources: finite
statistical sampling and the discretization of the Navier-Stokes equations. Due
to the presence of non-trivial sampling error, standard techniques for
estimating discretization error (such as Richardson extrapolation) fail or are
unreliable. This work provides a systematic and unified approach for estimating
these errors. First, a sampling error estimator that accounts for correlation
in the input data is developed. Then, this sampling error estimate is used as
part of a Bayesian extension of Richardson extrapolation in order to
characterize the discretization error. These methods are tested using the
Lorenz equations and are shown to perform well. These techniques are then used
to investigate the sampling and discretization errors in the DNS of a
wall-bounded turbulent flow. For both cases, it is found that while the
sampling uncertainty is large enough to make the order of accuracy difficult to
determine, the estimated discretization errors are quite small. This indicates
that the commonly used heuristics provide ad- equate resolution for this class
of problems. However, it is also found that, for some quantities, the
discretization error is not small relative to sampling error, indicating that
the conventional wisdom that sampling error dominates discretization error for
this class of simulations needs to be reevaluated.


title:
Dust Scattering In Turbulent Media: Correlation Between The Scattered
  Light and Dust Column Density

abstract:
  Radiative transfer models in a spherical, turbulent interstellar medium (ISM)
in which the photon source is situated at the center are calculated to
investigate the correlation between the scattered light and the dust column
density. The medium is modeled using fractional Brownian motion structures that
are appropriate for turbulent ISM. The correlation plot between the scattered
light and optical depth shows substantial scatter and deviation from simple
proportionality. It was also found that the overall density contrast is
smoothed out in scattered light. In other words, there is an enhancement of the
dust-scattered flux in low-density regions, while the scattered flux is
suppressed in high-density regions. The correlation becomes less significant as
the scattering becomes closer to be isotropic and the medium becomes more
turbulent. Therefore, the scattered light observed in near-infrared wavelengths
would show much weaker correlation than the observations in optical and
ultraviolet wavelengths. We also find that the correlation plot between
scattered lights at two different wavelengths shows a tighter correlation than
that of the scattered light versus the optical depth.


title: The Squared-Error of Generalized LASSO: A Precise Analysis

abstract:
  We consider the problem of estimating an unknown signal $x_0$ from noisy
linear observations $y = Ax_0 + z\in R^m$. In many practical instances, $x_0$
has a certain structure that can be captured by a structure inducing convex
function $f(\cdot)$. For example, $\ell_1$ norm can be used to encourage a
sparse solution. To estimate $x_0$ with the aid of $f(\cdot)$, we consider the
well-known LASSO method and provide sharp characterization of its performance.
We assume the entries of the measurement matrix $A$ and the noise vector $z$
have zero-mean normal distributions with variances $1$ and $\sigma^2$
respectively. For the LASSO estimator $x^*$, we attempt to calculate the
Normalized Square Error (NSE) defined as $\frac{\|x^*-x_0\|_2^2}{\sigma^2}$ as
a function of the noise level $\sigma$, the number of observations $m$ and the
structure of the signal. We show that, the structure of the signal $x_0$ and
choice of the function $f(\cdot)$ enter the error formulae through the summary
parameters $D(cone)$ and $D(\lambda)$, which are defined as the Gaussian
squared-distances to the subdifferential cone and to the $\lambda$-scaled
subdifferential, respectively. The first LASSO estimator assumes a-priori
knowledge of $f(x_0)$ and is given by $\arg\min_{x}\{{\|y-Ax\|_2}~\text{subject
to}~f(x)\leq f(x_0)\}$. We prove that its worst case NSE is achieved when
$\sigma\rightarrow 0$ and concentrates around $\frac{D(cone)}{m-D(cone)}$.
Secondly, we consider $\arg\min_{x}\{\|y-Ax\|_2+\lambda f(x)\}$, for some
$\lambda\geq 0$. This time the NSE formula depends on the choice of $\lambda$
and is given by $\frac{D(\lambda)}{m-D(\lambda)}$. We then establish a mapping
between this and the third estimator $\arg\min_{x}\{\frac{1}{2}\|y-Ax\|_2^2+
\lambda f(x)\}$. Finally, for a number of important structured signal classes,
we translate our abstract formulae to closed-form upper bounds on the NSE.


title:
Interaction-free all-optical switching at low light Intensities in a
  multi-atom cavity QED system

abstract:
  We propose a scheme of the interaction-free all-optical switching in a
multi-atom cavity QED system consisting of three-level atoms confined in a
cavity and coupled by a free-space control laser. A signal laser field is
coupled into the cavity and its transmission through and reflection from the
cavity form two output channels. We show that the free-space control laser
induces destructive quantum interference in the excitation of the intra-cavity
normal mode, which can be used to switch on or off of the output signal light
of the reflection and the transmission channels. When the control light is
coupled to the atoms, the input signal light is nearly totally reflected and
this means that there is no direct coupling of the control light and the signal
light through the cavity-confined atoms. We present analytical and numerical
calculations that show this type of the interaction-free all-optical switching
in the coupled cavity-atom system can be realized with high switching
efficiencies and at low light intensities.


title: On the Chern-Ricci flow and its solitons for Lie groups

abstract:
  This paper is concerned with Chern-Ricci flow evolution of left-invariant
hermitian structures on Lie groups. We study the behavior of a solution, as t
is approaching the first time singularity, by rescaling in order to prevent
collapsing and obtain convergence in the pointed (or Cheeger-Gromov) sense to a
Chern-Ricci soliton. We give some results on the Chern-Ricci form and the Lie
group structure of the pointed limit in terms of the starting hermitian metric
and, as an application, we obtain a complete picture for the class of solvable
Lie groups having a codimension one normal abelian subgroup. We have also found
a Chern-Ricci soliton hermitian metric on most of the complex surfaces which
are solvmanifolds, including an unexpected shrinking soliton example.


title:
A Comparative Study on Linguistic Feature Selection in Sentiment
  Polarity Classification

abstract:
  Sentiment polarity classification is perhaps the most widely studied topic.
It classifies an opinionated document as expressing a positive or negative
opinion. In this paper, using movie review dataset, we perform a comparative
study with different single kind linguistic features and the combinations of
these features. We find that the classic topic-based classifier(Naive Bayes and
Support Vector Machine) do not perform as well on sentiment polarity
classification. And we find that with some combination of different linguistic
features, the classification accuracy can be boosted a lot. We give some
reasonable explanations about these boosting outcomes.


title: Smooth backfitting in additive inverse regression

abstract:
  We consider the problem of estimating an additive regression function in an
inverse regres- sion model with a convolution type operator. A smooth
backfitting procedure is developed and asymptotic normality of the resulting
estimator is established. Compared to other meth- ods for the estimation in
additive models the new approach neither requires observations on a regular
grid nor the estimation of the joint density of the predictor. It is also
demonstrated by means of a simulation study that the backfitting estimator
outperforms the marginal in- tegration method at least by a factor two with
respect to the integrated mean squared error criterion.


title:
Optimal designs for nonlinear regression models with respect to
  non-informative priors

abstract:
  In nonlinear regression models the Fisher information depends on the
parameters of the model. Consequently, optimal designs maximizing some
functional of the information matrix cannot be implemented directly but require
some preliminary knowledge about the unknown parameters. Bayesian optimality
criteria provide an attractive solution to this problem. These criteria depend
sensitively on a reasonable specification of a prior distribution for the model
parameters which might not be available in all applications. In this paper we
investigate Bayesian optimality criteria with non-informative prior dis-
tributions. In particular, we study the Jeffreys and the Berger-Bernardo prior
for which the corresponding optimality criteria are not necessarily concave.
Several examples are investigated where optimal designs with respect to the new
criteria are calculated and compared to Bayesian optimal designs based on a
uniform and a functional uniform prior.


title:
New Regimes of Stringy (Holographic) Pomeron and High Multiplicity pp
  and pA Collisions

abstract:
  Holographic AdS/QCD models of the Pomeron unite a string-based description of
hadronic reactions of the pre-QCD era with the perturbative BFKL approach. The
specific version we will use due to Stoffers and Zahed, is based on a
semiclassical quantization of a "tube" (closed string exchange or open string
virtual pair production) in its Euclidean formulation using the scalar Polyakov
action. This model has a number of phenomenologically successful results. The
periodicity of a coordinate around the tube allows the introduction of a
Matsubara time and therefore an effective temperature Teff on the string. We
observe that at the LHC energies and for sufficiently small impact parameter,
Teff approaches and even exceeds the Hagedorn temperature of the QCD strings.
Based on studies of the stringy thermodynamics of pure gauge theories we
suggest that there should exist two new regimes of the Pomeron: the
"near-critical" and the "post-critical" ones. In the former one, string
excitations create a high entropy "string ball", with high energy and entropy
but small pressure/free energy. If heavy enough this ball becomes a (dual)
black hole (BH). As the intrinsic temperature of the string exceeds the
Hagedorn temperature, the ball becomes a post-critical explosive "QGP ball".
The hydrodynamical explosion resulting from this scenario was predicted by us
to have radial flow exceeding that ever seen even in heavy ion collisions,
which was recently confirmed by CMS and ALICE at LHC. We also discuss the
elastic scattering profile, finding some hints for new phases in it, as well as
two-particle correlations.


title: Heisenberg uncertainty for qubit measurements

abstract:
  Reports on experiments recently performed in Vienna [Erhard et al, Nature
Phys. 8, 185 (2012)] and Toronto [Rozema et al, Phys. Rev. Lett. 109, 100404
(2012)] include claims of a violation of Heisenberg's error-disturbance
relation. In contrast, we have presented and proven a Heisenberg-type relation
for joint measurements of position and momentum [Phys. Rev. Lett. 111, 160405
(2013)]. To resolve the apparent conflict, we formulate here a new general
trade-off relation for errors in qubit measurements, using the same concepts as
we did in the position-momentum case. We show that the combined errors in an
approximate joint measurement of a pair of +/-1 valued observables A,B are
tightly bounded from below by a quantity that measures the degree of
incompatibility of A and B. The claim of a violation of Heisenberg is shown to
fail as it is based on unsuitable measures of error and disturbance. Finally we
show how the experiments mentioned may directly be used to test our error
inequality.


title:
Electron Energy Loss Function of Silicene and Germanene Multilayers on
  Silver

abstract:
  We calculate electron energy loss spectra (EELS) for composite plasmonic
structures based on silicene and germanene. A continued-fraction expression for
the effective dielectric function is used to perform multiscale calculations of
EELS for both silicene and germanene-based structures on silver substrates. A
distinctive change in plasmonic response occurs for structures with a germanene
or silicene surface coating of more than three layers. These differences may be
exploited using spectroscopic characterization in order to determine if a
few-layer coating has been successfully fabricated.


title: Computation of hyperspherical Bessel functions

abstract:
  In this paper we present a fast and accurate numerical algorithm for the
computation of hyperspherical Bessel functions of large order and real
arguments. For the hyperspherical Bessel functions of closed type, no stable
algorithm existed so far due to the lack of a backwards recurrence. We solved
this problem by establishing a relation to Gegenbauer polynomials. All our
algorithms are written in C and are publicly available at Github
[https://github.com/lesgourg/class_public]. A Python wrapper is available upon
request.


title: Median statistics cosmological parameter values

abstract:
  We present median statistics central values and ranges for 12 cosmological
parameters, using 582 measurements (published during 1990-2010) collected by
Croft & Dailey (2011). On comparing to the recent Planck collaboration Ade et
al. 2013 estimates of 11 of these parameters, we find good consistency in nine
cases.


title: A multi-terabyte relational database for geo-tagged social network data

abstract:
  Despite their relatively low sampling factor, the freely available, randomly
sampled status streams of Twitter are very useful sources of geographically
embedded social network data. To statistically analyze the information Twitter
provides via these streams, we have collected a year's worth of data and built
a multi-terabyte relational database from it. The database is designed for fast
data loading and to support a wide range of studies focusing on the statistics
and geographic features of social networks, as well as on the linguistic
analysis of tweets. In this paper we present the method of data collection, the
database design, the data loading procedure and special treatment of geo-tagged
and multi-lingual data. We also provide some SQL recipes for computing network
statistics.


title: An Intuitive Design Approach For Implementing Real Time Audio Effects

abstract:
  Audio effect implementation on random musical signal is a basic application
of digital signal processors. In this paper, the compatibility features of
MATLAB R2008a with Code Composer Studio 3.3 has been exploited to develop
Simulink models which when emulated on TMS320C6713 DSK generate real time audio
effects. Each design has been done by two different asynchronous scheduling
techniques: (i) Idle task Scheduling and (ii) DSP/BIOS task Scheduling. A basic
COCOMO analysis has been done for the generated code to justify the industrial
viability of this design approach.
  KEYWORDS: Musical signal processing, Real time Audio effects, Echo, Stress
Generation, Reverberation, Reverberated Chorus, Real Time Scheduling.


title:
Resource Allocation for Network-Integrated Device-to-Device
  Communications Using Smart Relays

abstract:
  With increasing number of autonomous heterogeneous devices in future mobile
networks, an efficient resource allocation scheme is required to maximize
network throughput and achieve higher spectral efficiency. In this paper,
performance of network-integrated device-to-device (D2D) communication is
investigated where D2D traffic is carried through relay nodes. An optimization
problem is formulated for allocating radio resources to maximize end-to-end
rate as well as conversing QoS requirements for cellular and D2D user equipment
under total power constraint. Numerical results show that there is a distance
threshold beyond which relay-assisted D2D communication significantly improves
network performance when compared to direct communication between D2D peers.


title:
Predicting the Sun's Polar Magnetic Fields with a Surface Flux Transport
  Model

abstract:
  The Sun's polar magnetic fields are directly related to solar cycle
variability. The strength of the polar fields at the start (minimum) of a cycle
determine the subsequent amplitude of that cycle. In addition, the polar field
reversals at cycle maximum alter the propagation of galactic cosmic rays
throughout the heliosphere in fundamental ways. We describe a surface magnetic
flux transport model that advects the magnetic flux emerging in active regions
(sunspots) using detailed observations of the near-surface flows that transport
the magnetic elements. These flows include the axisymmetric differential
rotation and meridional flow and the non-axisymmetric cellular convective flows
(supergranules) all of which vary in time in the model as indicated by direct
observations. We use this model with data assimilated from full-disk
magnetograms to produce full surface maps of the Sun's magnetic field at
15-minute intervals from 1996 May to 2013 July (all of sunspot cycle 23 and the
rise to maximum of cycle 24). We tested the predictability of this model using
these maps as initial conditions, but with daily sunspot area data used to give
the sources of new magnetic flux. We find that the strength of the polar fields
at cycle minimum and the polar field reversals at cycle maximum can be reliably
predicted up to three years in advance. We include a prediction for the cycle
24 polar field reversal.


title: Search for the Higgs Boson $H_2^0$ at LHC in 3-3-1 Model

abstract:
  We present an analysis of production and signature of neutral Higgs boson
($H_{2}^{0}$) on the version of the 3-3-1 model containing heavy leptons at the
Large Hadron Collider. We studied the possibility to identify it using the
respective branching ratios. Cross section are given for the collider energy,
$\sqrt{s} =$ 14 TeV. Event rates and significances are discussed for two
possible values of integrated luminosity, 300 fb$^{-1}$ and 3000 fb$^{-1}$.


title: The Weyl Tensor of Gradient Ricci Solitons

abstract:
  This paper derives new identities for the Weyl tensor on a gradient Ricci
soliton, particularly in dimension four. First, we prove a
Bochner-Weitzenb\"ock type formula for the norm of the self-dual Weyl tensor
and discuss its applications, including connections between geometry and
topology. In the second part, we are concerned with the interaction of
different components of Riemannian curvature and (gradient and Hessian of) the
soliton potential function. The Weyl tensor arises naturally in these
investigations. Applications here are rigidity results.


title:
Factorizations in SL(2,Z) and simple examples of inequivalent Stein
  fillings

abstract:
  We give simple examples of elements of SL(2,Z) admitting inequivalent
factorizations into products of Dehn twists. This can be interpreted in terms
of inequivalent Stein fillings of a same contact 3-manifold by genus 1
Lefschetz fibrations over the disk.


title: Infrared Fixed Points in the minimal MOM Scheme

abstract:
  We analyze the behavior of several renormalization group functions at
infrared fixed points for $SU(N)$ gauge theories with fermions in the
fundamental and two-indexed representations. This includes the beta function of
the gauge coupling, the anomalous dimension of the gauge parameter and the
anomalous dimension of the mass. The scheme in which the analysis is performed
is the minimal momentum subtraction scheme through third loop order. Due to the
fact that scheme dependence is inevitable once the perturbation theory is
truncated we compare to previous identical studies done in the minimal
subtraction scheme and the modified regularization invariant scheme. We find
only mild to moderate scheme dependence.


title: Unary languages recognized by two-way one-counter automata

abstract:
  A two-way deterministic finite state automaton with one counter (2D1CA) is a
fundamental computational model that has been examined in many different
aspects since sixties, but we know little about its power in the case of unary
languages. Up to our knowledge, the only known unary nonregular languages
recognized by 2D1CAs are those formed by strings having exponential length,
where the exponents form some trivial unary regular language. In this paper, we
present some non-trivial subsets of these languages. By using the input head as
a second counter, we present simulations of two-way deterministic finite
automata with linearly bounded counters and linear--space Turing machines. We
also show how a fixed-size quantum register can help to simplify some of these
languages. Finally, we compare unary 2D1CAs with two--counter machines and
provide some insights about the limits of their computational power.


title: Using large galaxy surveys to distinguish z~0.5 quiescent galaxy models

abstract:
  One of the most striking properties of galaxies is the bimodality in their
star-formation rates. A major puzzle is why any given galaxy is star-forming or
quiescent, and a wide range of physical mechanisms have been proposed as
solutions. We consider how observations, such as might be available in upcoming
large galaxy surveys, might distinguish different galaxy quenching scenarios.
To do this, we combine an N-body simulation and multiple prescriptions from the
literature to create several quiescent galaxy mock catalogues. Each
prescription uses a different set of galaxy properties (such as history,
environment, centrality) to assign individual simulation galaxies as quiescent.
We find how and how much the resulting quiescent galaxy distributions differ
from each other, both intrinsically and observationally. In addition to tracing
observational consequences of different quenching mechanisms, our results
indicate which sorts of quenching models might be most readily disentangled by
upcoming observations and which combinations of observational quantities might
provide the most discriminatory power.
  Our observational measures are auto, cross, and marked correlation functions,
pro- jected density distributions, and group multiplicity functions, which rely
upon galaxy positions, stellar masses and of course quiescence. Although
degeneracies between models are present for individual observations, using
multiple observations in concert allows us to distinguish between all ten
models we consider. In addition to identifying intrinsic and observational
consequences of quiescence prescriptions and testing these quiescence models
against each other and observations, these methods can also be used to validate
colors (or other history and environment dependent properties) in simulated
mock catalogues.


title: Optimal Shrinkage of Eigenvalues in the Spiked Covariance Model

abstract:
  We show that in a common high-dimensional covariance model, the choice of
loss function has a profound effect on optimal estimation. In an asymptotic
framework based on the Spiked Covariance model and use of orthogonally
invariant estimators, we show that optimal estimation of the population
covariance matrix boils down to design of an optimal shrinker $\eta$ that acts
elementwise on the sample eigenvalues. Indeed, to each loss function there
corresponds a unique admissible eigenvalue shrinker $\eta^*$ dominating all
other shrinkers. The shape of the optimal shrinker is determined by the choice
of loss function and, crucially, by inconsistency of both eigenvalues and
eigenvectors of the sample covariance matrix. Details of these phenomena and
closed form formulas for the optimal eigenvalue shrinkers are worked out for a
menagerie of 26 loss functions for covariance estimation found in the
literature, including the Stein, Entropy, Divergence, Frechet,
Bhattacharya/Matusita, Frobenius Norm, Operator Norm, Nuclear Norm and
Condition Number losses.


title:
Interplay of many-body and single-particle interactions in iridates and
  rhodates

abstract:
  Motivated by recent experiments exploring the spin-orbit-coupled magnetism in
$4d$- and $5d$-band transition metal oxides, we study magnetic interactions in
Ir- and Rh-based compounds. In these systems, the comparable strength of
spin-orbit coupling (SOC), crystal field splitting (CF) and Coulomb and Hund's
coupling leads to a rich variety of magnetic exchange interactions, leading to
new types of ground states. Using a strong coupling approach, we derive
effective low-energy super-exchange Hamiltonians from the multi-orbital Hubbard
model by taking full account of the Coulomb and Hund's interactions in the
intermediate states. We find that in the presence of strong SOC and lattice
distortions the super-exchange Hamiltonian contains various kinds of magnetic
anisotropies.
  Here we are primarily interested in the magnetic properties of Sr$_2$IrO$_4$
and Sr$_2$Ir$_{1-x}$Rh$_x$O$_4$ compounds. We perform a systematic study of how
magnetic interactions in these systems depend on the microscopic parameters and
provide a thorough analysis of the resulting magnetic phase diagram. Comparison
of our results with experimental data shows good agreement. Finally, we discuss
the parameter space in which the spin-flop transition in Sr$_2$IrO$_4$,
experimentally observed under pressure, can be realized.


title: Dunkl operators at infinity and Calogero-Moser systems

abstract:
  We define the Dunkl and Dunkl-Heckman operators in infinite number of
variables and use them to construct the quantum integrals of the
Calogero-Moser-Sutherland problems at infinity. As a corollary we have a simple
proof of integrability of the deformed quantum CMS systems related to classical
Lie superalgebras. We show how this naturally leads to a quantum version of the
Moser matrix, which in the deformed case was not known before.


title:
An $O(N^3)$ algorithm for the calculation of far field radiation
  patterns

abstract:
  We present a new method for computing the Near-To-Far-Field (NTFF)
transformation in FDTD simulations which has an overall scaling of $O(N^3)$
instead of the standard $O(N^4)$. By mapping the far field with a cartesian
coordinate system the 2D surface integral can be split into two successive 1D
integrals. For a near field spanned by $N_X \times N_Y$ discrete sample points,
and a far field spanned by $N_{\theta} \times N_{\phi}$ points, the calculation
can then be performed in $O(N_{\theta}N_X N_Y) + O(N_{\theta}N_{\phi}N_Y)$
operations instead of $O(N_{\theta}N_{\phi}N_X N_Y)$.


title: Partial periodic quotient of groups acting on a hyperbolic space

abstract:
  In this article, we construct partial periodic quotients of groups which have
a non-elementary acylindrical action on a hyperbolic space. In particular, we
provide infinite quotients of mapping class groups where a fixed power of every
pseudo-Anosov homeomorphism is identified with a periodic or reducible element.