title:
Joint Coordinated Precoding and Discrete Rate Selection in Multicell
  MIMO Networks

abstract:
  Many practical wireless communications systems select their transmit rate
from a finite set of modulation and coding schemes, which correspond to a set
of discrete rates. In this paper, we therefore formulate a joint coordinated
precoding and discrete rate selection problem for multiple-input
multiple-output (MIMO) multicell networks. Compared to the common assumption of
using the continuous Shannon rates as the user utilities, explicitly accounting
for the discrete rates more accurately models practical wireless communication
systems. The optimization problem that we formulate is combinatorial and
non-convex, however, and is thus hard to solve. We therefore rewrite the
problem using a discontinuous rate function, which we then bound using its
concave envelope in some domain. Based on block coordinate descent, we provide
a convergent resource allocation algorithm which can be implemented in a
semi-distributed fashion. Numerical performance evaluation shows performance
gains when the discrete rates are optimized using our model, as compared to the
traditional methods which use the continuous Shannon rates as the user
utilities.


title:
A Characterisation of the Euclidean Fourier transform on the Schwartz
  space

abstract:
  We obtain a characterisation of the Fourier transform on the space of
Schwartz class functions on $\mathbb{R}^n.$ The result states that any
appropriately additive bijection of the Schwartz space onto itself, which
interchanges convolution and pointwise products is essentially the Fourier
transform.


title: Restricted trichotomy in higher dimensions

abstract:
  I prove, answering a question of Zilber, that if $M$ is an algebraic variety
of dimension strictly greater than one and $(M, \ldots)$ is a strongly minimal
structure with atomic relations definable in the Zariski language on $M$, then
$M$ is locally modular.


title: Asymptotic behaviour in the robot rendezvous problem

abstract:
  We present a non-technical overview of the results obtained by the authors
(2015) concerning the so-called robot rendezvous problem studied by Feintuch
and Francis (2012). In particular, we present a necessary and sufficient
condition for convergence of the solution in terms of Ces\`aro convergence of
the translates $S^k x_0$, $k\ge0$, of the sequence $x_0$ of initial positions
under the right-shift operator $S$, thus shedding new light on questions left
open in by Feintuch and Francis. We also formulate a stronger ergodic condition
on $x_0$ which ensures that the corresponding solution converges to its limit
at the rate $O(t^{-1/2})$ as $t\to\infty$. We conclude with a brief discussion
of a natural two-sided variant of the robot rendezvous problem and by relating
the robot rendezvous problem to a more realistic model of vehicle platoons, for
which the authors' earlier general results lead to analogous statements.


title:
Dirac topological insulator in the d$_{z^2}$ manifold of a honeycomb
  oxide

abstract:
  We show by means of ab initio calculations and tight-binding modeling that an
oxide system based on a honeycomb lattice can sustain topologically non-trivial
states if a single orbital dominates the spectrum close to the Fermi level. In
such situation, the low energy spectra is described by two Dirac equations that
become non-trivially gapped when spin-orbit coupling (SOC) is switched on. We
provide one specific example for this but the recipe is general. We discuss a
realization of this starting from a conventional spin-a-half honeycomb
antiferromagnet whose states close to the Fermi energy are d$_{z^2}$ orbitals.
Switching off magnetism by atomic substitution and ensuring that the electronic
structure becomes two-dimensional is sufficient for topologicality to arise in
such a system. We show that the gap in such model scales linearly with SOC,
opposed to other oxide-based topological insulators, where smaller gaps tend to
appear by construction of the lattice. We also provide a study of the quantum
Hall effect in such system, showing the close connections with the physics of
graphene but in a d-electron system.


title: A Safety and Liveness Theory for Total Reversibility (Extended Abstract)

abstract:
  We study the theory of safety and liveness in a reversible calculus where
reductions are totally ordered and rollbacks lead the systems to past states.
Similar to previous work on communicating transactions, liveness and safety
respectively correspond to the should-testing and inverse may-testing
preorders. We develop fully abstract models for these preorders in a reversible
calculus, which are based only on forward transitions, thus providing a simple
proof technique for refinement of such systems. We show that with respect to
safety, total reversibility is a conservative extension to CCS. With respect to
liveness, however, adding total reversibility to CCS distinguishes more
systems. To our knowledge, this work provides the first characterisations of
safety and liveness, and the first testing theory for a reversible calculus.


title:
Universal correlations between shocks in the ground state of elastic
  interfaces in disordered media

abstract:
  The ground state of an elastic interface in a disordered medium undergoes
collective jumps upon variation of external parameters. These mesoscopic jumps
are called shocks, or static avalanches. Submitting the interface to a
parabolic potential centered at $w$, we study the avalanches which occur as $w$
is varied. We are interested in the correlations between the avalanche sizes
$S_1$ and $S_2$ occurring at positions $w_1$ and $w_2$. Using the Functional
Renormalization Group (FRG), we show that correlations exist for realistic
interface models below their upper critical dimension. Notably, the connected
moment $ \langle S_1 S_2 \rangle^c$ is up to a prefactor exactly the
renormalized disorder correlator, itself a function of $|w_2-w_1|$. The latter
is the universal function at the center of the FRG; hence correlations between
shocks are universal as well. All moments and the full joint probability
distribution are computed to first non-trivial order in an $\epsilon$-expansion
below the upper critical dimension. To quantify the local nature of the
coupling between avalanches, we calculate the correlations of their local
jumps. We finally test our predictions against simulations of a particle in
random-bond and random-force disorder, with surprisingly good agreement.


title: AGI and Reflexivity

abstract:
  We define a property of intelligent systems, which we call Reflexivity. In
human beings, it is one aspect of consciousness, and an element of
deliberation. We propose a conjecture, that this property is conditioned by a
topological property of the processes which implement this reflexivity. These
processes may be symbolic, or non symbolic e.g. connexionnist. An architecture
which implements reflexivity may be based on the interaction of one or several
modules of deep learning, which may be specialized or not, and interconnected
in a relevant way. A necessary condition of reflexivity is the existence of
recurrence in its processes, we will examine in which cases this condition may
be sufficient. We will then examine how this topology and this property make
possible the expression of a second property, the deliberation. In a final
paragraph, we propose an evaluation of intelligent systems, based on the
fulfillment of all or some of these properties.


title:
Interior eigenvalue density of large bi-diagonal matrices subject to
  random perturbations

abstract:
  We study the spectrum of large a bi-diagonal Toeplitz matrix subject to a
Gaussian random perturbation with a small coupling constant. We obtain a
precise asymptotic description of the average density of eigenvalues in the
interior of the convex hull of the range symbol.


title: Efficient Calculation of Bigram Frequencies in a Corpus of Short Texts

abstract:
  We show that an efficient and popular method for calculating bigram
frequencies is unsuitable for bodies of short texts and offer a simple
alternative. Our method has the same computational complexity as the old method
and offers an exact count instead of an approximation.


title:
Quadratic algebra for superintegrable monopole system in a Taub-NUT
  space

abstract:
  We introduce a Hartmann system in the generalized Taub-NUT space with Abelian
monopole interaction. This quantum system includes well known Kaluza-Klein
monopole and MIC-Zwanziger monopole as special cases. It is shown that the
corresponding Schrodinger equation of the Hamiltonian is separable in both
spherical and parabolic coordinates. We obtain the integrals of motion of this
superintegrable model and construct the quadratic algebra and Casimir operator.
This algebra can be realized in terms of a deformed oscillator algebra and has
finite dimensional unitary representations (unirreps) which provide energy
spectra of the system. This result coincides with the physical spectra obtained
from the separation of variables.


title:
Electric field control of deterministic current-induced magnetization
  switching in a hybrid ferromagnetic/ferroelectric structure

abstract:
  All-electrical and programmable manipulations of ferromagnetic bits are
highly pursued for the aim of high integration and low energy consumption in
modern information technology. Methods based on the spin-orbit torque switching
in heavy metal/ferromagnet structures have been proposed with magnetic field,
and recently are heading toward deterministic switching without external
magnetic field. Here we demonstrate that an in-plane effective magnetic field
can be induced by an electric field without breaking the symmetry of the
structure of the thin film, and realize the deterministic magnetization
switching in a hybrid ferromagnetic/ferroelectric structure with Pt/Co/Ni/Co/Pt
layers on PMN-PT substrate. The effective magnetic field can be reversed by
changing the direction of the applied electric field on the PMN-PT substrate,
which fully replaces the controllability function of the external magnetic
field. The electric field is found to generate an additional spin-orbit torque
on the CoNiCo magnets, which is confirmed by macrospin calculations.


title: Ad Exchange: Envy-Free Auctions with Mediators

abstract:
  Ad exchanges are an emerging platform for trading advertisement slots on the
web with billions of dollars revenue per year. Every time a user visits a web
page, the publisher of that web page can ask an ad exchange to auction off the
ad slots on this page to determine which advertisements are shown at which
price. Due to the high volume of traffic, ad networks typically act as
mediators for individual advertisers at ad exchanges. If multiple advertisers
in an ad network are interested in the ad slots of the same auction, the ad
network might use a "local" auction to resell the obtained ad slots among its
advertisers.
  In this work we want to deepen the theoretical understanding of these new
markets by analyzing them from the viewpoint of combinatorial auctions. Prior
work studied mostly single-item auctions, while we allow the advertisers to
express richer preferences over multiple items. We develop a game-theoretic
model for the entanglement of the central auction at the ad exchange with the
local auctions at the ad networks. We consider the incentives of all three
involved parties and suggest a three-party competitive equilibrium, an
extension of the Walrasian equilibrium that ensures envy-freeness for all
participants. We show the existence of a three-party competitive equilibrium
and a polynomial-time algorithm to find one for gross-substitute bidder
valuations.


title: Do we know what the temperature is?

abstract:
  Temperature, the central concept of thermal physics, is one of the most
frequently employed physical quantities in common practice. Even though the
operative methods of the temperature measurement are described in detail in
various practical instructions and textbooks, the rigorous treatment of this
concept is almost lacking in the current literature. As a result, the answer to
a simple question of "what the temperature is" is by no means trivial and
unambiguous. There is especially an appreciable gap between the temperature as
introduced in the frame of statistical theory and the only experimentally
observable quantity related to this concept, phenomenological temperature. Just
the logical and epistemological analysis of the present concept of
phenomenological temperature is the kernel of the contribution.


title:
Examples of Plentiful Discrete Spectra in0 Infinite Spatial Cruciform
  Quantum Waveguides

abstract:
  Spatial cruciform quantum waveguides (the Dirichlet problem for Laplace
operator) are constructed such that the total multiplicity of the discrete
spectrum exceeds any preassigned number.


title:
Complementarity of PALM and SOFI for super-resolution live cell imaging
  of focal adhesions

abstract:
  Live cell imaging of focal adhesions requires a sufficiently high temporal
resolution, which remains a challenging task for super-resolution microscopy.
We have addressed this important issue by combining photo-activated
localization microscopy (PALM) with super-resolution optical fluctuation
imaging (SOFI). Using simulations and fixed cell focal adhesion images, we
investigated the complementarity between PALM and SOFI in terms of spatial and
temporal resolution. This PALM-SOFI framework was used to image focal adhesions
in living cells, while obtaining a temporal resolution below 10 s. We
visualized the dynamics of focal adhesions, and revealed local mean velocities
around 190 nm per minute. The complementarity of PALM and SOFI was assessed in
detail with a methodology that integrates a quantitative resolution and
signal-to-noise metric. This PALM and SOFI concept provides an enlarged
quantitative imaging framework, allowing unprecedented functional exploration
of focal adhesions through the estimation of molecular parameters such as the
fluorophore density and the photo-activation and photo-switching rates.


title: Nature of the X(5568) : a critical Laplace sum rule analysis at N2LO

abstract:
  We scrutinize recent QCD spectral sum rules (QSSR) results to lowest order
(LO) predicting the masses of the BK molecule and (su)\bar(bd) four-quark
states. We improve these results by adding NLO and N2LO corrections to the PT
contributions giving a more precise meaning on the b-quark mass definition used
in the analysis. We extract our optimal predictions using Laplace sum rule
(LSR) within the standard stability criteria versus the changes of the external
free parameters (\tau-sum rule variable, t_c continuum threshold and
subtraction constant \mu). The smallness of the higher order PT corrections
justifies (a posteriori) the LO order results + the uses of the ambiguous heavy
quark mass to that order. However, our predicted spectra in the range (5173\sim
5226) MeV, summarized in Table 7, for exotic hadrons built with four different
flavours (buds), do not support some previous interpretations of the D0
candidate[1], X(5568), as a pure molecule or a four-quark state. If
experimentally confirmed, it could result from their mixing with an angle: sin
2\theta\approx 0.15. One can also scan the region (2327~ 2444) MeV (where the
D*_{s0}(2317) might be a good candidate) and the one (5173~ 5226) MeV for
detecting these (cuds) and (buds) unmixed exotic hadrons (if any) via,
eventually, their radiative or \pi+hadrons decays.


title: Nonlinear normal modes, modal interactions and isolated resonance curves

abstract:
  The objective of the present study is to explore the connection between the
nonlinear normal modes of an undamped and unforced nonlinear system and the
isolated resonance curves that may appear in the damped response of the forced
system. To this end, an energy balancing technique is used to predict the
amplitude of the harmonic forcing that is necessary to excite a specific
nonlinear normal mode. A cantilever beam with a nonlinear spring at its tip
serves to illustrate the developments. The practical implications of isolated
resonance curves are also discussed by computing the beam response to sine
sweep excitations of increasing amplitudes.


title: Fluctuational electrodynamics for nonlinear media

abstract:
  We develop fluctuational electrodynamics for media with nonlinear optical
response. In a perturbative manner, we amend the stochastic Helmholtz equation
to describe fluctuations in a nonlinear setting, in agreement with the
fluctuation dissipation theorem, and identify the local (Rytov) current
fluctuations. We show how the linear response (the solution of the scattering
problem) of a collection of objects is found from the individual responses, as
measured in isolation. As an example, we compute the Casimir force acting
between nonlinear objects which approaches the result for linear optics for
large separations, and deviates for small distances.


title: The Scale-Invariant Scotogenic Model

abstract:
  We investigate a minimal scale-invariant implementation of the scotogenic
model and show that viable electroweak symmetry breaking can occur while
simultaneously generating one-loop neutrino masses and the dark matter relic
abundance. The model predicts the existence of a singlet scalar (dilaton) that
plays the dual roles of triggering electroweak symmetry breaking and sourcing
lepton number violation. Important constraints are studied, including those
from lepton flavor violating effects and dark matter direct-detection
experiments. The latter turn out to be somewhat severe, already excluding large
regions of parameter space. None the less, viable regions of parameter space
are found, corresponding to dark matter masses below (roughly) 10 GeV and above
200 GeV.


title:
Real-Time Contingency Analysis with Corrective Transmission Switching -
  Part I: Methodology

abstract:
  Transmission switching (TS) has gained significant attention recently.
However, barriers still remain and must be overcome before the technology can
be adopted by the industry. The state of the art challenges include AC
feasibility and performance, computational complexity, the ability to handle
large-scale real power systems, and dynamic stability. This two-part paper
investigates these challenges by developing an AC TS-based real-time
contingency analysis (RTCA) tool that can handle large-scale systems within a
reasonable time. The tool proposes multiple corrective switching actions, after
detection of a contingency with potential violations. To reduce the
computational complexity, three heuristic algorithms are proposed to generate a
small set of candidates for switching. Parallel computing is implemented to
further speed up the solution time. Furthermore, stability analysis is
performed to check for dynamic stability of proposed TS solutions. Part I of
the paper presents a comprehensive literature review and the methodology. The
promising results, tested on the Tennessee Valley Authority (TVA) system and
actual energy management system (EMS) snapshots from Pennsylvania New Jersey
Maryland (PJM) and the Electric Reliability Council of Texas (ERCOT), are
presented in Part II. It is concluded that RTCA with corrective TS
significantly reduces potential post-contingency violations and is ripe for
industry adoption.


title:
Real-Time Contingency Analysis with Corrective Transmission Switching -
  Part II: Results and Discussion

abstract:
  This paper presents the performance of an AC transmission switching (TS)
based real-time contingency analysis (RTCA) tool that is introduced in Part I
of this paper. The approach quickly proposes high quality corrective switching
actions for relief of potential post-contingency network violations. The
approach is confirmed by testing it on actual EMS snapshots of two large-scale
systems, the Electric Reliability Council of Texas (ERCOT) and the Pennsylvania
New Jersey Maryland (PJM) Interconnection; the approach is also tested on data
provided by the Tennessee Valley Authority (TVA). The results show that the
tool effectively reduces post-contingency violations. Fast heuristics are used
along with parallel computing to reduce the computational difficulty of the
problem. The tool is able to handle the PJM system in about five minutes with a
standard desktop computer. Time-domain simulations are performed to check
system stability with corrective transmission switching (CTS). In conclusion,
the paper shows that corrective switching is ripe for industry adoption. CTS
can provide significant reliability benefits that can be translated into
significant cost savings.


title: Does Anonymity Increase the Chance to Get Feedback?

abstract:
  To generate a hypothesis about the effects of anonymity on user participation
in online communities, comments on Youtube were analysed for effects of the
change from allowing pseudonyms to Google+ with its real name policy. Small
differences were detected, leading to the hypothesis that the option to remain
anonymous leads to a less active environment for getting feedback, with less
polite and less rude comments on the expense of neutral ones.


title: On Efficient Decoding and Design of Sparse Random Linear Network Codes

abstract:
  Random linear network coding (RLNC) in theory achieves the max-flow capacity
of multicast networks, at the cost of high decoding complexity. To improve the
performance-complexity tradeoff, we consider the design of sparse network
codes. A generation-based strategy is employed in which source packets are
grouped into overlapping subsets called generations. RLNC is performed only
amongst packets belonging to the same generation throughout the network so that
sparseness can be maintained. In this paper, generation-based network codes
with low reception overheads and decoding costs are designed for transmitting
of the order of $10^2$-$10^3$ source packets. A low-complexity
overhead-optimized decoder is proposed that exploits "overlaps" between
generations. The sparseness of the codes is exploited through local processing
and multiple rounds of pivoting of the decoding matrix. To demonstrate the
efficacy of our approach, codes comprising a binary precode, random overlapping
generations, and binary RLNC are designed. The results show that our designs
can achieve negligible code overheads at low decoding costs, and outperform
existing network codes that use the generation based strategy.


title:
The role of initial state and final quench temperature on the aging
  properties in phase-ordering kinetics

abstract:
  We study numerically the two-dimensional Ising model with non-conserved
dynamics quenched from an initial equilibrium state at the temperature $T_i\ge
T_c$ to a final temperature $T_f$ below the critical one. By considering
processes initiating both from a disordered state at infinite temperature
$T_i=\infty$ and from the critical configurations at $T_i=T_c$ and spanning the
range of final temperatures $T_f\in [0,T_c[$ we elucidate the role played by
$T_i$ and $T_f$ on the aging properties and, in particular, on the behavior of
the autocorrelation $C$ and of the integrated response function $\chi$. Our
results show that for any choice of $T_f$, while the autocorrelation function
exponent $\lambda _C$ takes a markedly different value for $T_i=\infty$
[$\lambda _C(T_i=\infty)\simeq 5/4$] or $T_i=T_c$ [$\lambda _C(T_i=T_c)\simeq
1/8$] the response function exponents are unchanged. Supported by the outcome
of the analytical solution of the solvable spherical model we interpret this
fact as due to the different contributions provided to autocorrelation and
response by the large-scale properties of the system. As changing $T_f$ is
considered, although this is expected to play no role in the
large-scale/long-time properties of the system, we show important effects on
the quantitative behavior of $\chi$. In particular, data for quenches to
$T_f=0$ are consistent with a value of the response function exponent $\lambda
_\chi=\frac{1}{2}\lambda _C(T_i=\infty)=5/8$ different from the one [$\lambda
_\chi \in (0.5-0.56)$] found in a wealth of previous numerical determinations
in quenches to finite final temperatures. This is interpreted as due to
important pre-asymptotic corrections associated to $T_f>0$.


title:
Deciphering the complex intermediate role of health coverage through
  insurance in the context of well-being by network analysis

abstract:
  Recent initiatives that overstate health insurance coverage for well-being
conflict with the recognized antagonistic facts identified by the determinants
of health that identify health care as an intermediate factor. By using a
network of controlled interdependences among multiple social resources
including health insurance, which we reconstructed from survey data of the U.S.
and Bayesian networks structure learning algorithms, we examined why health
insurance through coverage, which in most countries is the access gate to
health care, is just an intermediate factor of well-being. We used social
network analysis methods to explore the complex relationships involved at
general, specific and particular levels of the model. All levels provide
evidence that the intermediate role of health insurance relies in a strong
relationship to income and reproduces its unfair distribution. Some signals
about the most efficient type of health coverage emerged in our analyses.


title: Using Apache Lucene to Search Vector of Locally Aggregated Descriptors

abstract:
  Surrogate Text Representation (STR) is a profitable solution to efficient
similarity search on metric space using conventional text search engines, such
as Apache Lucene. This technique is based on comparing the permutations of some
reference objects in place of the original metric distance. However, the
Achilles heel of STR approach is the need to reorder the result set of the
search according to the metric distance. This forces to use a support database
to store the original objects, which requires efficient random I/O on a fast
secondary memory (such as flash-based storages). In this paper, we propose to
extend the Surrogate Text Representation to specifically address a class of
visual metric objects known as Vector of Locally Aggregated Descriptors (VLAD).
This approach is based on representing the individual sub-vectors forming the
VLAD vector with the STR, providing a finer representation of the vector and
enabling us to get rid of the reordering phase. The experiments on a publicly
available dataset show that the extended STR outperforms the baseline STR
achieving satisfactory performance near to the one obtained with the original
VLAD vectors.


title:
Contribution to the Formal Specification and Verification of a
  Multi-Agent Robotic System

abstract:
  It is important to have multi-agent robotic system specifications that ensure
correctness properties of safety and liveness. As these systems have
concurrency, and often have dynamic environment, the formal specification and
verification of these systems along with step-wise refinement from abstract to
concrete concepts play a major role in system correctness. Formal verification
is used for exhaustive investigation of the system space thus ensuring that
undetected failures in the behavior are excluded. We construct the system
incrementally from subcomponents, based on software architecture. The challenge
is to develop a safe multi-agent robotic system, more specifically to ensure
the correctness properties of safety and liveness. Formal specifications based
on model-checking are flexible, have a concrete syntax, and play vital role in
correctness of a multi-agent robotic system. To formally verify safety and
liveness of such systems is important because they have high concurrency and in
most of the cases have dynamic environment. We have considered a case-study of
a multi-agent robotic system for the transport of stock between storehouses to
exemplify our formal approach. Our proposed development approach allows for
formal verification during specification definition. The development process
has been classified in to four major phases of requirement specifications,
verification specifications, architecture specifications and implementation.


title: A unified approach for summation formulae

abstract:
  Summation formulae are classical tools in analysis: Taylor-MacLaurin,
Euler-MacLaurin, Poisson, Vorono\"i, Circle formulae\ldots
  We will show how, from a single equation - referred to as the mother-equation
- it is possible to unify these formulae and many others within a common
formalism. Indeed, these formulae are paired up: every summation formula is
associated with an asymptotic expansion. For example, the Euler-MacLaurin's
formula turns out to be the asymptotic expansion associated with the Poisson's
formula, the Taylor-MacLaurin's formula being of course the expansion of the
function initially considered.
  As is generally the case in sciences, this unifying concept is also
generating new results. Asymptotic expansions for Vorono\"i and Circle formulae
are presented first, then we show how to develop a M\"obius-Poisson's summation
formula with its Euler-M\"obius-Poisson asymptotic expansion.


title:
On the bilinear square Fourier multiplier operators and related
  multilinear square functions

abstract:
  Let $n\ge 1$ and $\mathfrak{T}_{m}$ be the bilinear square Fourier multiplier
operator associated with a symbol $m$, which is defined by $$
\mathfrak{T}_{m}(f_1,f_2)(x) = \biggl(
\int_{0}^\infty\Big|\int_{(\mathbb{R}^n)^2} e^{2\pi ix\cdot (\xi_1 +\xi_2)
}m(t\xi_1,t\xi_2) \hat{f}_{1}(\xi_1)\hat{f}_{2}(\xi_2)d\xi_1
d\xi_2\Big|^2\frac{dt}{t } \biggr)^{\frac 12}. $$ Let $s$ be an integer with
$s\in[n+1,2n]$ and $p_0$ be a number satisfying $2n/s\le p_0\le 2$. Suppose
that $\nu_{\vec{\omega}}=\prod_{i=1}^2\omega_i^{p/ p_i}$ and each $\omega_i$ is
a nonnegative function on $\mathbb{R}^n$. In this paper, we show that
$\mathfrak{T}_{m}$ is bounded from $L^{p_1}(\omega_1)\times L^{p_2}(\omega_2)$
to $L^p(\nu_{\vec{\omega}})$ if $p_0< p_1, p_2<\infty$ with $1/p=1/p_1+ 1/p_2$.
Moreover, if $p_0>2n/s$ and $p_1=p_0$ or $p_2=p_0$, then $\mathfrak{T}_{m}$ is
bounded from $L^{p_1}(\omega_1)\times L^{p_2}(\omega_2)$ to
$L^{p,\infty}(\nu_{\vec{\omega}})$. The weighted end-point $L\log L$ type
estimate and strong estimate for the commutators of $\mathfrak{T}_{m}$ are also
given. These were done by considering the boundedness of some related
multilinear square functions associated with mild regularity kernels and
essentially improving some basic lemmas which have been used before.


title: Deterministic generation of large scale atomic W states

abstract:
  We present a deterministic scheme for generating large-scale atomic W states
in cavity QED system via a simple expansion mechanism, which is realized only
by a detuned interaction between two identical atoms and a vacuum cavity mode.
With the presented scheme, a W-type Bell pair can be created and an n-atom W
state can be expanded to a 2n-atom W state with a unit probability of success
in principle. No multi-atom gates, quantum memories or quantum non-demolition
measurements are required, greatly simplifying the experimental realization of
the scheme. The feasibility analysis shows that our expansion scheme can be
implemented with state-of-the-art technologies. Our scheme enables advances not
only in quantum information and communication but also in quantum
thermodynamics, where atomic W states plays a crucial role.


title: On the non-Paschian ordered planes

abstract:
  We give a non-Paschian plane based on the property of betweenness which
cannot be derived from an ordering of the points of a line. In this model there
is no possibility to define the congruence of segments but we can define angle,
triangle and angle measure, respectively. With respect to our definitions the
plane has an elliptic character, meaning that the sum of the angles of a
triangle is greater than $\pi$.


title: On Decay Centrality

abstract:
  We establish a relationship between decay centrality and two widely used and
computationally cheaper measures of centrality, namely degree and closeness. We
show that for low values of the decay parameter the nodes with maximum decay
centrality also have maximum degree, whereas for high values of the decay
parameter they also maximize closeness. For intermediate values, we provide
sufficient conditions that allow the comparison of decay centrality of
different nodes and we show via numerical simulations that in the vast majority
of networks, the nodes with maximum decay centrality are characterized by a
threshold on the decay parameter below which they belong to the set of nodes
with maximum degree and above which they belong to the set of nodes with
maximum closeness. We also propose a simple rule of thumb that ensures a nearly
optimal choice with very high probability.


title:
Scattering of oblique waves by permeable vertical flexible membrane wave
  barriers

abstract:
  The interaction of obliquely incident surface gravity waves with a vertical
flexible permeable membrane wave barrier is investigated in the context of
three-dimensional linear wave-structure interaction theory. A general
formulation for wave interaction with permeable submerged vertical membrane is
given. The analytic solution of the physical problem is obtained by using
eigenfunction expansion method, and boundary element method has been used to
get the numerical solution. In the boundary element method, since the boundary
condition on the membrane is not known in advance, membrane motions and
velocity potentials are solved simultaneously. From the general formulation of
the submerged membrane barrier, the performance of bottom-standing,
surface-piercing and fully extended membrane wave barriers are analyzed for
various wave and structural parameters. It is found that the efficiency of the
submerged, surface-piercing and bottom-standing membrane wave barriers can be
enhanced in waves for certain design conditions. From the analysis of various
membrane configurations and parameters, it can be concluded that permeable
membrane wave barrier can function as a very effective breakwater if it is
properly designed.


title:
Optimal investment and consumption with downside risk constraint in
  jump-diffusion models

abstract:
  This paper extends the results of the article [C. Kl\"{u}ppelberg and S. M.
Pergamenchtchikov. Optimal consumption and investment with bounded downside
risk for power utility functions. In Optimality and Risk: {\it Modern Trends in
Mathematical Finance. The Kabanov Festschrift}, pages 133-169, 2009] to a
jump-diffusion setting. We show that under the assumption that only positive
jumps in the asset prices are allowed, the explicit optimal strategy can be
found in the subset of admissible strategies satisfying the same risk
constraint as in the pure diffusion setting. When negative jumps probably
happen, the regulator should be more conservative. In that case, we suggest to
impose on the investor's portfolio a stricter constraint which depends on the
probability of having negative jumps in the assets during the whole considered
horizon.


title: Astrophysical components from Planck maps

abstract:
  The Planck Collaboration has recently released maps of the microwave sky in
both temperature and polarization. Diffuse astrophysical components (including
Galactic emissions, cosmic far infrared (IR) background, y-maps of the thermal
Sunyaev-Zeldovich (SZ) effect) and catalogs of many thousands of Galactic and
extragalactic radio and far-IR sources, and galaxy clusters detected through
the SZ effect are the main astrophysical products of the mission. A concise
overview of these results and of astrophysical studies based on Planck data is
presented.


title:
New tidal debris nearby the Sagittarius leading tail from the LAMOST DR2
  M giant stars

abstract:
  We report two new tidal debris nearby the Sagittarius (Sgr) tidal stream in
the north Galactic cap identified from the M giant stars in LAMOST DR2 data.
The M giant stars with sky area of $210^\circ<$\Lambda$<290^\circ$, distance of
10--20kpc, and [Fe/H]$<-0.75$ show clear bimodality in velocity distribution.
We denote the two peaks as Vel-3+83 for the one within mean velocity of
-3kms$^{-1}$ with respect to that of the well observed Sgr leading tail at the
same $\Lambda$ and Vel+162+26 for the other one with mean velocity of
162kms$^{-1}$ with respect to the Sgr leading tail. Although the projected
$\Lambda$--$V_{gar}$ relation of Vel-3+83 is very similar to the Sgr leading
tail, the opposite trend in $\Lambda$--distance relation against the Sgr
leading tail suggests Vel-3+83 has a different 3D direction of motion with any
branch of the simulated Sgr tidal stream from Law & Majewski. Therefore, we
propose it to be a new tidal debris not related to the Sgr stream. Similarly,
the another substructure Vel+162+26, which is the same one as the NGC group
discovered by Chou et al., also moves toward a different direction with the Sgr
stream, implying that it may have different origin with the Sgr tidal stream.


title:
Assessment of backgrounds of the ANAIS experiment for dark matter direct
  detection

abstract:
  A large effort has been carried out to characterize the background of sodium
iodide crystals within the ANAIS (Annual modulation with NaI Scintillators)
project. In this paper, the background models developed for three 12.5-kg
NaI(Tl) scintillators produced by Alpha Spectra Inc. and operated at the
Canfranc Underground Laboratory are presented together with an evaluation of
the background prospects for the full experiment. Measured spectra from
threshold to high energy in different conditions are well described by the
models based on quantified activities. At the region of interest, crystal bulk
contamination is the dominant background source. Contributions from 210Pb, 40K,
22Na and 3H are the most relevant. Those from 40K and 22Na could be efficiently
suppressed thanks to anticoincidence operation in a crystals matrix or inside a
Liquid Scintillator Veto (LSV), while that from 210Pb has been reduced by
improving crystal production methods and 3H production could be reduced by
shielding against cosmic rays during production. Assuming the activities of the
last characterized detector, for nine crystals with a total mass of 112.5 kg
the expected background rate is 2.5 counts/(keV kg d) in the region from 1 to 4
keV, which could be reduced at 1.4 counts/(keV kg d) by using a LSV.

categories: astro-ph.IM hep-ex nucl-ex physics.ins-det


title:
On planar variants of the monotone satisfiability problem with bounded
  variable appearances

abstract:
  We show NP-completeness for several planar variants of the monotone
satisfiability problem with bounded variable appearances. With one exception
the presented variants have an associated bipartite graph where the vertex
degree is bounded by at most four. Hence, a planar and orthogonal drawing for
these graphs can be computed efficiently, which may turn out to be useful in
reductions using these variants as a starting point for proving some decision
problem to be NP-hard.


title:
Coupling couples with copulas: analysis of assortative matching on risk
  attitude

abstract:
  We investigate patterns of assortative matching on risk attitude, using
self-reported (ordinal) data on risk attitudes for males and females within
married couples, from the German Socio-Economic Panel over the period
2004-2012. We apply a novel copula-based bivariate panel ordinal model.
Estimation is in two steps: firstly, a copula-based Markov model is used to
relate the marginal distribution of the response in different time periods,
separately for males and females; secondly, another copula is used to couple
the males' and females' conditional (on the past) distributions. We find
positive dependence, both in the middle of the distribution, and in the joint
tails, and we interpret this as positive assortative matching (PAM). Hence we
reject standard assortative matching theories based on risk-sharing
assumptions, and favour models based on alternative assumptions such as the
ability of agents to control income risk. We also find evidence of
"assimilation"; that is, PAM appearing to increase with years of marriage.


title: Locating a Small Cluster Privately

abstract:
  We present a new algorithm for locating a small cluster of points with
differential privacy [Dwork, McSherry, Nissim, and Smith, 2006]. Our algorithm
has implications to private data exploration, clustering, and removal of
outliers. Furthermore, we use it to significantly relax the requirements of the
sample and aggregate technique [Nissim, Raskhodnikova, and Smith, 2007], which
allows compiling of "off the shelf" (non-private) analyses into analyses that
preserve differential privacy.


title:
The flux dynamics behavior of the two competing high temperature
  superconducting phases in underdoped LaCuO4.06

abstract:
  In complex transition metal oxides (TMO) an arrested electronic phase
separation (PS) appears by tuning the system near a Lifshitz transition in
multiband Hubbard models. The PS in La2CuO4+y near insulator to metal
transition (IMT) is made of short range Charge Density Wave (CDW) order
inhomogeneity coexisting with quenched lattice disorder. While at high doping
y=0.1 percolation gives a single superconducting phase, near the IMT at y=0.06
two coexisting superconducting phases appear: the first one with a critical
temperature Tc1=16 K and the second one with Tc2=29K. It is known that the two
superconducting phases are characterized by two different space geometry
because of two different spatial distributions of both CDW order and dopants
self-organization. Here we show that these two phases show different flux
dynamic regimes using alternating current (AC) multi-harmonic susceptibility
experiments. This is a unique technique capable to investigate multi-phase
superconductors and characterize their transport properties in a percolative
scenario. Results point out that the low critical temperature phase is well
described by a bulk-like flux pinning with a 2D geometry while the phase with
higher critical temperature shows a barrier pinning mechanism providing direct
evidence of two different superconducting vortex dynamics in different complex
geometrical spaces.


title: WarpNet: Weakly Supervised Matching for Single-view Reconstruction

abstract:
  We present an approach to matching images of objects in fine-grained datasets
without using part annotations, with an application to the challenging problem
of weakly supervised single-view reconstruction. This is in contrast to prior
works that require part annotations, since matching objects across class and
pose variations is challenging with appearance features alone. We overcome this
challenge through a novel deep learning architecture, WarpNet, that aligns an
object in one image with a different object in another. We exploit the
structure of the fine-grained dataset to create artificial data for training
this network in an unsupervised-discriminative learning approach. The output of
the network acts as a spatial prior that allows generalization at test time to
match real images across variations in appearance, viewpoint and articulation.
On the CUB-200-2011 dataset of bird categories, we improve the AP over an
appearance-only network by 13.6%. We further demonstrate that our WarpNet
matches, together with the structure of fine-grained datasets, allow
single-view reconstructions with quality comparable to using annotated point
correspondences.


title:
$I=1$ and $I=2$ $\pi-\pi$ scattering phase shifts from $N_{\mathrm{f}} =
  2+1$ lattice QCD

abstract:
  The $I=1$ $p$-wave and $I=2$ $s$-wave elastic $\pi$-$\pi$ scattering
amplitudes are calculated from a first-principles lattice QCD simulation using
a single ensemble of gauge field configurations with $N_{\mathrm{f}} = 2+1$
dynamical flavors of anisotropic clover-improved Wilson fermions. This ensemble
has a large spatial volume $V=(3.7\mathrm{fm})^3$, pion mass $m_{\pi} =
230\mathrm{MeV}$, and spatial lattice spacing $a_s = 0.11\mathrm{fm}$.
Calculation of the necessary temporal correlation matrices is efficiently
performed using the stochastic LapH method, while the large volume enables an
improved energy resolution compared to previous work. For this single ensemble
we obtain $m_{\rho}/m_{\pi} = 3.350(24)$, $g_{\rho\pi\pi} = 5.99(26)$, and a
clear signal for the $I=2$ $s$-wave. The success of the stochastic LapH method
in this proof-of-principle large-volume calculation paves the way for
quantitative study of the lattice spacing effects and quark mass dependence of
scattering amplitudes using state-of-the-art ensembles.


title:
Average Regularity of the Solution to an Equation with the
  Relativistic-free Transport Operator

abstract:
  Let $u=u(t,{\bf x},{\bf p})$ satisfy the transport equation $\frac {\partial
u}{\partial t}+\frac {{\bf p}}{p_0}\frac{\partial u}{\partial{\bf x}}=f$, where
$f=f(t,\bf x,\bf p)$ belongs to $ L^{p}((0,T)\times {\bf R}^{3}\times {\bf
R}^{3})$ for $1<p<\infty$ and $\frac {\partial}{\partial t}+\frac {{\bf
p}}{p_0}\frac{\partial}{\partial{\bf x}}$ is the relativistic-free transport
operator. We show the regularity of $\int_{{\bf R}^{3}}u(t, {\bf x}, {\bf
p})d{\bf p}$ using the same method as given by Golse, Lions, Perthame and
Sentis. This average regularity is considered in terms of fractional Sobolev
spaces and it is very useful for the study of the existence of the solution to
the Cauchy problem on the relativistic Boltzmann equation.


title: Holographic equation of state in fluid/gravity duality

abstract:
  We establish a precise relation between mixed boundary conditions for scalar
fields in asymptotically anti de Sitter spacetimes and the equation of state of
the dual fluid. We provide a detailed derivation of the relation in the case of
five bulk-dimensions for scalar fields saturating the Breitenlohner-Freedman
bound. As a concrete example, we discuss the five dimensional scalar-tensor
theories describing a constant speed of sound.


title:
Tesla : an application for real-time data analysis in High Energy
  Physics

abstract:
  Upgrades to the LHCb computing infrastructure in the first long shutdown of
the LHC have allowed for high quality decay information to be calculated by the
software trigger making a separate offline event reconstruction unnecessary.
Furthermore, the storage space of the triggered candidate is an order of
magnitude smaller than the entire raw event that would otherwise need to be
persisted. Tesla, following the LHCb renowned physicist naming convention, is
an application designed to process the information calculated by the trigger,
with the resulting output used to directly perform physics measurements.


title: Atomic spin chain realization of a model for quantum criticality

abstract:
  The ability to manipulate single atoms has opened up the door to constructing
interesting and useful quantum structures from the ground up. On the one hand,
nanoscale arrangements of magnetic atoms are at the heart of future quantum
computing and spintronic devices; on the other hand, they can be used as
fundamental building blocks for the realization of textbook many-body quantum
models, illustrating key concepts such as quantum phase transitions,
topological order or frustration. Step-by-step assembly promises an interesting
handle on the emergence of quantum collective behavior as one goes from one, to
few, to many constituents. To achieve this, one must however maintain the
ability to tune and measure local properties as the system size increases.
Here, we use low-temperature scanning tunneling microscopy to construct arrays
of magnetic atoms on a surface, designed to behave like spin-1/2 XXZ Heisenberg
chains in a transverse field, for which a quantum phase transition from an
antiferromagnetic to a paramagnetic phase is predicted in the thermodynamic
limit. Site-resolved measurements on these finite size realizations reveal a
number of sudden ground state changes when the field approaches the critical
value, each corresponding to a new domain wall entering the chains. We observe
that these state crossings become closer for longer chains, indicating the
onset of critical behavior. Our results present opportunities for further
studies on quantum behavior of many-body systems, as a function of their size
and structural complexity.


title:
Regime switching vine copula models for global equity and volatility
  indices

abstract:
  For nearly every major stock market there exist equity and implied volatility
indices. These play important roles within finance: be it as a benchmark, a
measure of general uncertainty or a way of investing or hedging. It is well
known in the academic literature, that correlations and higher moments between
different indices tend to vary in time. However, to the best of our knowledge,
no one has yet considered a global setup including both, equity and implied
volatility indices of various continents, and allowing for a changing
dependence structure. We aim to close this gap by applying Markov-switching
$R$-vine models to investigate the existence of different, global dependence
regimes. In particular, we identify times of "normal" and "abnormal" states
within a data set consisting of North-American, European and Asian indices. Our
results confirm the existence of joint points in time at which global regime
switching takes place.


title: Simple J-Factors and D-Factors for Indirect Dark Matter Detection

abstract:
  J-factors (or D-factors) describe the distribution of dark matter in an
astrophysical system and determine the strength of the signal provided by
annihilating (or decaying) dark matter respectively. We provide simple analytic
formulae to calculate the J-factors for spherical cusps obeying the empirical
relationship between enclosed mass, velocity dispersion and half-light radius.
We extend the calculation to the spherical Navarro-Frenk-White (NFW) model, and
demonstrate that our new formulae give accurate results in comparison to more
elaborate Jeans models driven by Markov Chain Monte Carlo methods. Of the known
ultrafaint dwarf spheroidals, we show that Ursa Major II, Reticulum II, Tucana
II and Horologium I have the largest J-factors and so provide the most
promising candidates for indirect dark matter detection experiments. Amongst
the classical dwarfs, Draco, Sculptor and Ursa Minor have the highest
J-factors. We show that the behaviour of the J-factor as a function of
integration angle can be inferred for general dark halo models with inner slope
$\gamma$ and outer slope $\beta$. The central and asymptotic behaviour of the
J-factor curves are derived as a function of the dark halo properties. Finally,
we show that models obeying the empirical relation on enclosed mass and
velocity dispersion have J-factors that are most robust at the integration
angle equal to the projected half-light radius of the dSph divided by
heliocentric distance. For most of our results, we give the extension to the
D-factor which is appropriate for the decaying dark matter picture.


title:
Finding shared decisions in stakeholder networks: an agent-based
  approach

abstract:
  We address the problem of a participatory decision-making process where a
shared priority list of alternatives has to be obtained while avoiding
inconsistent decisions. An agent-based model (ABM) is proposed to mimic this
process in different social networks of stakeholders who interact according to
an opinion dynamics model. Simulations' results show the efficacy of
interaction in finding a transitive and, above all, shared decision. These
findings are in agreement with real participation experiences regarding
transport planning decisions and can give useful suggestions on how to plan an
effective participation process for sustainable policy-making based on opinion
consensus.


title:
New families of special numbers for computing negative order Euler
  numbers

abstract:
  The main purpose of this paper is to construct new families of special
numbers with their generating functions. These numbers are related to the many
well-known numbers, which are the Bernoulli numbers, the Fibonacci numbers, the
Lucas numbers, the Stirling numbers of the second kind and the central
factorial numbers. Our other inspiration of this paper is related to the
Golombek's problem \cite{golombek} \textquotedblleft Aufgabe 1088, El. Math. 49
(1994) 126-127\textquotedblright . Our first numbers are not only related to
the Golombek's problem, but also computation of the negative order Euler
numbers. We compute a few values of the numbers which are given by some tables.
We give some applications in Probability and Statistics. That is, special
values of mathematical expectation in the binomial distribution and the
Bernstein polynomials give us the value of our numbers. Taking derivative of
our generating functions, we give partial differential equations and also
functional equations. By using these equations, we derive recurrence relations
and some formulas of our numbers. Moreover, we give two algorithms for
computation our numbers. We also give some combinatorial applications, further
remarks on our numbers and their generating functions.


title: Deuteration of ammonia in the starless core Ophiuchus/H-MM1

abstract:
  Ammonia and its deuterated isotopologues probe physical conditions in dense
molecular cloud cores. With the aim of testing the current understanding of the
spin-state chemistry of these molecules, we observed spectral lines of NH3,
NH2D, NHD2, ND3, and N2D+ towards a dense, starless core in Ophiuchus with the
APEX, GBT, and IRAM 30-m telescopes. The observations were interpreted using a
gas-grain chemistry model combined with radiative transfer calculations. The
chemistry model distinguishes between the different nuclear spin states of
light hydrogen molecules, ammonia, and their deuterated forms. High deuterium
fractionation ratios with NH2D/NH3=0.4, NHD2/NH2D=0.2, and ND3/NHD2=0.06 were
found in the core. The observed ortho/para ratios of NH2D and NHD2 are close to
the corresponding nuclear spin statistical weights. The chemistry model can
approximately reproduce the observed abundances, but predicts uniformly too low
ortho/para-NH2D, and too large ortho/para-NHD2 ratios. The longevity of N2H+
and NH3 in dense gas, which is prerequisite to their strong deuteration, can be
attributed to the chemical inertia of N2 on grain surfaces. The discrepancies
between the chemistry model and the observations are likely to be caused by the
fact that the model assumes complete scrambling in principal gas-phase
deuteration reactions of ammonia, which means that all the nuclei are mixed in
reactive collisions. If, instead, these reactions occur through proton
hop/hydrogen abstraction processes, statistical spin ratios are to be expected.
The present results suggest that while the deuteration of ammonia changes with
physical conditions and time, the nuclear spin ratios of ammonia isotopologues
do not probe the evolutionary stage of a cloud.


title: Online Ad Assignment with an Ad Exchange

abstract:
  Ad exchanges are becoming an increasingly popular way to sell advertisement
slots on the internet. An ad exchange is basically a spot market for ad
impressions. A publisher who has already signed contracts reserving
advertisement impressions on his pages can choose between assigning a new ad
impression for a new page view to a contracted advertiser or to sell it at an
ad exchange. This leads to an online revenue maximization problem for the
publisher. Given a new impression to sell decide whether (a) to assign it to a
contracted advertiser and if so to which one or (b) to sell it at the ad
exchange and if so at which reserve price. We make no assumptions about the
distribution of the advertiser valuations that participate in the ad exchange
and show that there exists a simple primal-dual based online algorithm, whose
lower bound for the revenue converges to $R_{ADX} + R_A (1 - 1/e)$, where
$R_{ADX}$ is the revenue that the optimum algorithm achieves from the ad
exchange and $R_A$ is the revenue that the optimum algorithm achieves from the
contracted advertisers.


title:
Kinematically Identified Recoiling Supermassive Black Hole Candidates in
  SDSS QSOs with z $<$ 0.25

abstract:
  We have performed a spectral decomposition to search for recoiling
supermassive black holes (rSMBH) in the SDSS QSOs with $z<0.25$. Out of 1271
QSOs, we have identified 26 rSMBH candidates that are recoiling toward us. The
projected recoil velocities range from $-76\ \kms$ to $-307\ \kms$ with a mean
of $-149\pm58\ \kms$. Most of the rSMBH candidates are hosted by gas-rich
LIRGs/ULIRGs, but only 23\% of them shows signs of tidal features suggesting
majority of them are advanced mergers. We find that the black hole masses
$M_{BH}$ of the rSMBH candidates are on average $\sim$5 times smaller than that
of their stationary counterparts and cause a scatter in $M_{BH}-\sigma_*$
relation. The Eddington ratios of all of the rSMBH candidates are larger than
0.1, with mean of 0.52$\pm$0.27, suggesting they are actively accreting mass.
Velocity shifts in high-excitation coronal lines suggest that the rSMBH
candidates are recoiling with an average velocity of about $-265\ \kms$.
Electron density in the narrow line region of the H II rSMBH candidates is
about 1/10 of that in AGN rSMBH candidates probably because AGN in the former
was more spatially offset than that in the latter. The estimated spatial
offsets between the rSMBH candidate and center of host galaxy range from
0.21\as \ to 1.97\as \ and need to be confirmed spatially with high-resolution
adaptive optics imaging observations.


title: Right whale recognition using convolutional neural networks

abstract:
  We studied the feasibility of recognizing individual right whales (Eubalaena
glacialis) using convolutional neural networks. Prior studies have shown that
CNNs can be used in wide range of classification and categorization tasks such
as automated human face recognition. To test applicability of deep learning to
whale recognition we have developed several models based on best practices from
literature. Here, we describe the performance of the models. We conclude that
machine recognition of whales is feasible and comment on the difficulty of the
problem


title:
Mixed Hodge Structures on the rational homotopy type of intersection
  spaces

abstract:
  Let $X$ a complex projective variety of complex dimension $n$ with only
isolated singularities of simply connected links. We show that we can endow the
rational cohomology of the family of the $\overline{p}$-perverse intersection
spaces $\{ I^{\overline{p}}X \}$ with compatible mixed Hodge structures.


title: K-theory for the $C^*$-algebras of the solvable Baumslag-Solitar groups

abstract:
  We provide a new computation of the K-theory of the group $C^*$-algebra of
the solvable Baumslag-Solitar group $BS(1,n)\;(n\neq 1)$; our computation is
based on the Pimsner-Voiculescu 6-terms exact sequence, by viewing $BS(1,n)$ as
a semi-direct product $\mathbb{Z}[1/n]\rtimes\mathbb{Z}$. We deduce from it a
new proof of the Baum-Connes conjecture with trivial coefficients for
$BS(1,n)$.


title:
Computation Methods for combinatorial sums and Euler type numbers
  related to new families of numbers

abstract:
  The aim of this article is to define some new families of the special
numbers. These numbers provide some further motivation for computation of
combinatorial sums involving binomial coefficients and the Euler kind numbers
of negative order. We can show that these numbers are related to the well-known
numbers and polynomials such as the Stirling numbers of the second kind and the
central factorial numbers, the array polynomials, the rook numbers and
polynomials, the Bernstein basis functions and others. In order to derive our
new identities and relations for these numbers, we use a technique including
the generating functions and functional equations. Finally, we not only give a
computational algorithm for these numbers, but also some numerical values of
these numbers and the Euler numbers of negative order with tables. We also give
some combinatorial interpretations of our new numbers.


title: Approximation Algorithms for the Maximum Carpool Matching Problem

abstract:
  The Maximum Carpool Matching problem is a star packing problem in directed
graphs. Formally, given a directed graph $G = (V, A)$, a capacity function $ c:
V \to N $, and a weight function $w : A \to R $, a feasible \emph{carpool
matching} is a triple $(P, D, M)$, where $P$ (passengers) and $D$ (drivers)
form a partition of $V$, and $M$ is a subset of $A \cap (P \times D)$, under
the constraints that for every vertex $d \in D$, $din(d) \leq c(d)$, and for
every vertex $p \in P$, $dout(p) \leq 1$. In the Maximum Carpool Matching
problem we seek for a matching $(P, D, M)$ that maximizes the total weight of
$M$.
  The problem arises when designing an online carpool service, such as
Zimride~\cite{zimride}, that tries to connect between passengers and drivers
based on (arbitrary) similarity function. The problem is known to be NP-hard,
even for uniform weights and without capacity constraints.
  We present a $3$-approximation algorithm for the problem and
$2$-approximation algorithm for the unweighted variant of the problem.


title: Formation of the penumbra and start of the Evershed flow

abstract:
  We studied the variations of line-of-sight photospheric plasma flows during
the formation phase of the penumbra around a pore in Active Region NOAA 11490.
We used a high spatial, spectral, and temporal resolution data set acquired by
the Interferometric BIdimensional Spectrometer (IBIS) operating at the NSO/Dunn
Solar Telescope as well as data taken by the Helioseismic and Magnetic Imager
onboard the Solar Dynamics Observatory satellite (SDO/HMI). Before the penumbra
formed we observed a redshift of the spectral line in the inner part of the
annular zone surrounding the pore as well as a blueshift of material associated
with opposite magnetic polarity further away from the pore. We found that the
onset of the classical Evershed flow occurs in a very short time scale -- 1-3
hours -- while the penumbra is forming. During the same time interval we found
changes in the magnetic field inclination in the penumbra, with the vertical
field actually changing sign near the penumbral edge, while the total magnetic
field showed a significant increase, about 400 G. To explain these and other
observations related to the formation of the penumbra and the onset of the
Evershed flow we propose a scenario in which the penumbra is formed by magnetic
flux dragged down from the canopy surrounding the initial pore. The Evershed
flow starts when the sinking magnetic field dips below the solar surface and
magnetoconvection sets in.


title:
Trigonometric Parallaxes and Proper Motions of 134 Southern Late M, L,
  and T Dwarfs from the Carnegie Astrometric Planet Search Program

abstract:
  We report trigonometric parallaxes for 134 low mass stars and brown dwarfs,
of which 38 have no previously published measurement and 79 more have improved
uncertainties. Our survey targeted nearby targets, so 119 are closer than 30
pc. Of the 38 stars with new parallaxes, 14 are within 20 pc and seven are
likely brown dwarfs (spectral types later than L0). These parallaxes are useful
for studies of kinematics, multiplicity, and spectrophotometric calibration.
Two objects with new parallaxes are confirmed as young stars with membership in
nearby young moving groups: LP 870-65 in AB Doradus and G 161-71 in Argus. We
also report the first parallax for the planet-hosting star GJ 3470; this allows
us to refine the density of its Neptune-mass planet. One T-dwarf, 2MASS
J12590470-4336243, previously thought to lie within 4 pc, is found to be at 7.8
pc, and the M-type star 2MASS J01392170-3936088 joins the ranks of nearby stars
as it is found to be within 10 pc. Five stars that are over-luminous and/or too
red for their spectral types are identified and deserve further study as
possible young stars.


title:
Experimental observation of anomalous topological edge modes in a
  slowly-driven photonic lattice

abstract:
  The discovery of the quantised Hall effect, and its subsequent topological
explanation, demonstrated the important role topology can play in determining
the properties of quantum systems. This realisation led to the development of
topological band theory, where, in addition to band index and quasimomentum,
Bloch bands are also characterised by a set of topological invariants. This
topological theory can be readily extended to periodically-driven systems. In
the limit of fast driving, the topology of the system can still be captured by
the topological invariants used to describe static systems. In the limit of
slow driving, however, situations can arise where standard topological
invariants are zero, but yet, topologically protected edge modes are still
observed. These "anomalous" topological edge modes have no static analogue, and
are associated with a distinct topological invariant, which takes into account
the full time-evolution over a driving period. Here we demonstrate the first
experimental observation of such anomalous topological edge modes in an
ultrafast-laser-inscribed photonic lattice. This inscription technique allows
one to address each bond of a lattice independently and dynamically, generating
a rich band structure with robust anomalous chiral edge modes and the potential
for perfectly localised bulk states.


title:
A chemical solver to compute molecule and grain abundances and non-ideal
  MHD resistivities in prestellar core collapse calculations

abstract:
  We develop a detailed chemical network relevant to the conditions
characteristic of prestellar core collapse. We solve the system of
time-dependent differential equations to calculate the equilibrium abundances
of molecules and dust grains, with a size distribution given by size-bins for
these latter. These abundances are used to compute the different non-ideal
magneto-hydrodynamics resistivities (ambipolar, Ohmic and Hall), needed to
carry out simulations of protostellar collapse. For the first time in this
context, we take into account the evaporation of the grains, the thermal
ionisation of Potassium, Sodium and Hydrogen at high temperature, and the
thermionic emission of grains in the chemical network, and we explore the
impact of various cosmic ray ionisation rates. All these processes
significantly affect the non-ideal magneto-hydrodynamics resistivities, which
will modify the dynamics of the collapse. Ambipolar diffusion and Hall effect
dominate at low densities, up to n_H = 10^12 cm^-3, after which Ohmic diffusion
takes over. We find that the time-scale needed to reach chemical equilibrium is
always shorter than the typical dynamical (free fall) one. This allows us to
build a large, multi-dimensional multi-species equilibrium abundance table over
a large temperature, density and ionisation rate ranges. This table, which we
make accessible to the community, is used during first and second prestellar
core collapse calculations to compute the non-ideal magneto-hydrodynamics
resistivities, yielding a consistent dynamical-chemical description of this
process.


title:
Lifts of pseudo-Anosov homeomorphisms of nonorientable surfaces have
  vanishing SAF invariant

abstract:
  We show that any pseudo-Anosov map that is a lift of pseudo-Anosov
homeomorphism of a nonorientable surface has vanishing SAF invariant. We also
provide a criterion to certify that a pseudo-Anosov map is not such a lift.


title:
Tuning the work function in transition metal oxides and their
  heterostructures

abstract:
  The development of novel functional materials in experimental labs combined
with computer-based compound simulation brings the vision of materials design
on a microscopic scale continuously closer to reality. For many applications
interface and surface phenomena rather than bulk properties are key. One of the
most fundamental qualities of a material-vacuum interface is the energy
required to transfer an electron across this boundary, i.e. the work function.
It is a crucial parameter for numerous applications, including organic
electronics, field electron emitters, and thermionic energy converters. Being
generally very resistant to degradation at high temperatures, transition metal
oxides present a promising materials class for such devices. We have performed
a systematic study for perovskite oxides that provides reference values and,
equally important, reports on materials trends and the tunability of work
functions. Our results identify and classify dependencies of the work function
on several parameters including specific surface termination, surface
reconstructions, oxygen vacancies, and heterostructuring.


title: Finite time blowup for parabolic systems in two dimensions

abstract:
  We construct examples of finite time singularity from smooth data for linear
uniformly parabolic systems in the plane. We obtain similar examples for
quasilinear systems with coefficients that depend only on the solution.


title: Effective potential method for active particles

abstract:
  We investigate the steady state properties of an active fluid modeled as an
assembly of soft repulsive spheres subjected to Gaussian colored noise. Such a
noise captures one of the salient aspects of active particles, namely the
persistence of their motion and determines a variety of novel features with
respect to familiar passive fluids. We show that within the so-called
multidimensional unified colored noise approximation, recently introduced in
the field of active matter, the model can be treated by methods similar to
those employed in the study of standard molecular fluids. The system shows a
tendency of the particles to aggregate even in the presence of purely repulsive
forces because the combined action of colored noise and interactions enhances
the the effective friction between nearby particles. We also discuss whether an
effective two-body potential approach, which would allow to employ methods
similar to those of density functional theory, is appropriate. The limits of
such an approximation are discussed.


title: Modelling of Nonthermal Microwave Emission From Twisted Magnetic Loops

abstract:
  Microwave gyrosynchrotron radio emission generated by nonthermal electrons in
twisted magnetic loops is modelled using the recently developed simulation tool
GX Simulator. We consider isotropic and anisotropic pitch-angle distributions.
The main scope of the work is to understand impact of the magnetic field
twisted topology on resulted radio emission maps. We have found that nonthermal
electrons inside twisted magnetic loops produce gyrosynchrotron radio emission
with peculiar polarization distribution. The polarization sign inversion line
is inclined relatively to the axis of the loop. Radio emission source is more
compact in the case of less twisted loop, considering anisotropic pitch-angle
distribution of nonthermal electrons.


title: On Makarov's principle in conformal mapping

abstract:
  We examine several characteristics of conformal maps that resemble the
variance of a Gaussian: asymptotic variance, the constant in Makarov's law of
iterated logarithm and the second derivative of the integral means spectrum at
the origin. While these quantities need not be equal in general, they agree for
domains whose boundaries are regular fractals such as Julia sets or limit sets
of quasi-Fuchsian groups. We give a new proof of these dynamical equalities. We
also show that these characteristics have the same universal bounds and prove a
central limit theorem for extremals. Our method is based on analyzing the local
variance of dyadic martingales associated to Bloch functions.


title: Deuteron potential using the noncritical holographic model

abstract:
  Deuteron has been studied using a noncritical holographic
quantumchromodynamics model constructed in the six-dimensional Anti-de-Sitter
supergravity background. The nucleus potential energy is calculated. The
binding energy has been estimated as the minimum of the potential energy. The
roles of various mesons in producing the deuteron potential energy are
discussed in details.


title:
The harmonic balance method for bifurcation analysis of large-scale
  nonlinear mechanical systems

abstract:
  The harmonic balance (HB) method is widely used in the literature for
analyzing the periodic solutions of nonlinear mechanical systems. The objective
of this paper is to exploit the method for bifurcation analysis, i.e., for the
detection and tracking of bifurcations of nonlinear systems. To this end, an
algorithm that combines the computation of the Floquet exponents with bordering
techniques is developed. A new procedure for the tracking of Neimark-Sacker
bifurcations that exploits the properties of eigenvalue derivatives is also
proposed. The HB method is demonstrated using numerical experiments of a
spacecraft structure that possesses a nonlinear vibration isolation device.


title:
Understanding Noise and Interference Regimes in 5G Millimeter-Wave
  Cellular Networks

abstract:
  With the severe spectrum shortage in conventional cellular bands,
millimeter-wave (mmWave) frequencies have been attracting growing attention for
next-generation micro- and picocellular wireless networks. A fundamental and
open question is whether mmWave cellular networks are likely to be noise- or
interference-limited. Identifying in which regime a network is operating is
critical for the design of MAC and physical-layer procedures and to provide
insights on how transmissions across cells should be coordinated to cope with
interference. This work uses the latest measurement-based statistical channel
models to accurately assess the Interference-to-Noise Ratio (INR) in a wide
range of deployment scenarios. In addition to cell density, we also study
antenna array size and antenna patterns, whose effects are critical in the
mmWave regime. The channel models also account for blockage, line-of-sight and
non-line-of-sight regimes as well as local scattering, that significantly
affect the level of spatial isolation.


title: Channel Dynamics and SNR Tracking in Millimeter Wave Cellular Systems

abstract:
  The millimeter wave (mmWave) frequencies are likely to play a significant
role in fifth-generation (5G) cellular systems. A key challenge in developing
systems in these bands is the potential for rapid channel dynamics: since
mmWave signals are blocked by many materials, small changes in the position or
orientation of the handset relative to objects in the environment can cause
large swings in the channel quality. This paper addresses the issue of tracking
the signal to noise ratio (SNR), which is an essential procedure for rate
prediction, handover and radio link failure detection. A simple method for
estimating the SNR from periodic synchronization signals is considered. The
method is then evaluated using real experiments in common blockage scenarios
combined with outdoor statistical models.


title: On the origin of impinging tones at low supersonic flow

abstract:
  Impinging compressible jets may cause deafness and material fatigue due to
immensely loud tonal noise. It is generally accepted that a feedback mechanism
similar to the screech feedback loop is responsible for impinging tones. The
close of the loop remained unclear. One hypothesis hold up in the literature
explains the emanated sound with the direct interaction of vortices and the
wall. Other explanations name the standoff shock oscillations as the origin of
the tones. Using direct numerical simulations (DNS) we were able to identify
the source mechanism for under-expanded impinging jets with a nozzle pressure
ratio (NPR) of 2.15 and a plate distance of 5 diameters. We found two different
types of interactions between vortices and shocks to be responsible for the
generation of the impinging tones. They are not related to screech.


title:
Limits on the power-law mass and luminosity density profiles of
  elliptical galaxies from gravitational lensing systems

abstract:
  We use 118 strong gravitational lenses observed by the SLACS, BELLS, LSD and
SL2S surveys to constrain the total mass profile and the profile of luminosity
density of stars (light-tracers) in elliptical galaxies up to redshift $z \sim
1$. Assuming power-law density profiles for the total mass density,
$\rho=\rho_0(r/r_0)^{-\alpha}$, and luminosity density,
$\nu=\nu_0(r/r_0)^{-\delta}$, we investigate the power law index and its first
derivative with respect to the redshift. Using Monte Carlo simulations of the
posterior likelihood taking the Planck's best-fitted cosmology as a prior, we
find $\gamma= 2.132\pm0.055$ with a mild trend $\partial \gamma/\partial z_l=
-0.067\pm0.119$ when $\alpha=\delta=\gamma$, suggesting that the total density
profile of massive galaxies could have become slightly steeper over cosmic
time. Furthermore, similar analyses performed on sub-samples defined by
different lens redshifts and velocity dispersions, indicate the need of
treating low, intermediate and high-mass galaxies separately. Allowing $\delta$
to be a free parameter, we obtain $\alpha=2.070\pm0.031$, $\partial
\alpha/\partial z_l= -0.121\pm0.078$, and $\delta= 2.710\pm0.143$. The model in
which mass traces light is rejected at $>95\%$ confidence and our analysis
robustly indicates the presence of dark matter in the form of a mass component
that is differently spatially extended than the light. In this case,
intermediate-mass elliptical galaxies ($200$ km/s $ < \sigma_{ap} \leq 300$
km/s) show the best consistency with the singular isothermal sphere as an
effective model of galactic lenses.


title:
Observation of spin Seebeck contribution to the transverse thermopower
  in Ni-Pt and MnBi-Au bulk nanocomposites

abstract:
  Transverse thermoelectric devices produce electric fields perpendicular to an
incident heat flux. Classically, this process is driven by the Nernst effect in
bulk solids, wherein a magnetic field generates a Lorentz force on thermally
excited electrons. The spin Seebeck effect (SSE) also produces
magnetization-dependent transverse electric fields. SSE is traditionally
observed in thin metallic films deposited on electrically insulating
ferromagnets, but the films' high resistance limits thermoelectric conversion
efficiency. Combining Nernst and SSE in bulk materials would enable devices
with simultaneously large transverse thermopower and low electrical resistance.
Here we demonstrate experimentally this is possible in composites of conducting
ferromagnets (Ni or MnBi) containing metallic nanoparticles with strong
spin-orbit interactions (Pt or Au). These materials display positive shifts in
transverse thermopower attributable to inverse spin Hall electric fields in the
nanoparticles. This more than doubles the power output of the Ni-Pt materials,
establishing proof-of-principle that SSE persists in bulk nanocomposites.


title:
Non-thermal separation of electronic and structural orders in a
  persisting charge density wave

abstract:
  The simultaneous ordering of different degrees of freedom in complex
materials undergoing spontaneous symmetry-breaking transitions often involves
intricate couplings that have remained elusive in phenomena as wide ranging as
stripe formation, unconventional superconductivity or colossal
magnetoresistance. Ultrafast optical, x-ray and electron pulses can elucidate
the microscopic interplay between these orders by probing the electronic and
lattice dynamics separately, but a simultaneous direct observation of multiple
orders on the femtosecond scale has been challenging. Here we show that
ultrabroadband terahertz pulses can simultaneously trace the ultrafast
evolution of coexisting lattice and electronic orders. For the example of a
charge-density-wave (CDW) in 1T-TiSe2, we demonstrate that two components of
the CDW order parameter - excitonic correlations and a periodic lattice
distortion (PLD) - respond very differently to 12-fs optical excitation. Even
when the excitonic order of the CDW is quenched, the PLD can persist in a
coherently excited state. This observation proves that excitonic correlations
are not the sole driving force of the CDW transition in 1T-TiSe2, and
exemplifies the sort of profound insight that disentangling strongly coupled
components of order parameters in the time domain may provide for the
understanding of a broad class of phase transitions.


title: Firehose constraints for the solar wind suprathermal electrons

abstract:
  The indefinite increase of temperature predicted by the solar wind expansion
in the direction parallel to the interplanetary magnetic field is already
notorious for not being confirmed by the observations. In hot and dilute
plasmas from space particle-particle collisions are not efficient in
constraining large deviations from isotropy, but the resulting firehose
instability provides in this case plausible limitations for the temperature
anisotropy of the thermal (core) populations of both the electron and proton
species. The present paper takes into discussion the suprathermal (halo)
electrons, which are ubiquitous in the solar wind. Less dense but hotter than
the core, suprathermals may be highly anisotropic and susceptible to the
firehose instability. The main features of the instability are here derived
from a first-order theory for conditions specific to the suprathermal electrons
in the solar wind and terrestrial magnetospheres. Unveiled here, new regimes of
the electron firehose instability may be exclusively controlled by the
suprathermals. The instability is found to be systematically stimulated by the
suprathermal electrons, with thresholds that approach the limits of the
temperature anisotropy reported by the observations. These results represent
new and valuable evidences for the implication of the firehose instability in
the relaxation of the temperature anisotropy in space plasmas.


title: Projective Limits of State Spaces: Quantum Field Theory without a Vacuum

abstract:
  Instead of formulating the states of a Quantum Field Theory (QFT) as density
matrices over a single large Hilbert space, it has been proposed by Kijowski
[Kijowski, 1977] to construct them as consistent families of partial density
matrices, the latter being defined over small 'building block' Hilbert spaces.
In this picture, each small Hilbert space can be physically interpreted as
extracting from the full theory specific degrees of freedom. This allows to
reduce the quantization of a classical field theory to the quantization of
finite-dimensional sub-systems, thus sidestepping some of the common
ambiguities (specifically, the issues revolving around the choice of a 'vacuum
state'), while obtaining robust and well-controlled quantum states spaces.
  The present letter provides a self-contained introduction to this formalism,
detailing its motivations as well as its relations to other approaches to QFT
(such as conventional Fock-like Hilbert spaces, path-integral quantization, and
the algebraic formulation). At the same time, it can serve as a reading guide
to the series of more in-depth articles [arXiv:1411.3589, arXiv:1411.3590,
arXiv:1411.3591, arXiv:1510.01926].


title:
Large-N CP(N-1) sigma model on a finite interval: physical boundary
  effects

abstract:
  We analyze the two-dimensional CP(N-1) sigma model defined on a finite space
interval L, with various boundary conditions, in the large N limit. With the
Dirichlet boundary condition at the both ends, we show that the system has a
unique phase, which smoothly approaches in the large L limit the standard 2D
CP(N-1) sigma model in confinement phase, with a constant mass generated for
the n(i) fields. We study the full functional saddle-point equations for finite
L, and solve them numerically. The latter reduces to the well-known gap
equation in the large L limit. It is found that the solution satisfies actually
both the Dirichlet and Neumann conditions.


title:
Negative Refraction, Beam Steering, Mode Switching, and High-pass
  Filtering in a 1-D Periodic Laminate

abstract:
  In this paper we show that a 1-D phononic crystal (laminate) can exhibit
metamaterial wave phenomenon which is traditionally associated with 2-, and 3-D
crystals. Moreover, due to the absence of a length scale in 2 of its
dimensions, it can outperform higher dimensional crystals on some measures.
This includes allowing only negative refraction over large frequency ranges and
serving as a near-omnidirectional high-pass filter up to a large frequency
value. First we provide a theoretical discussion on the salient characteristics
of the dispersion relation of a laminate and formulate the solution of an
interface problem by the application of the normal mode decomposition
technique. We present a methodology with which to induce a pure negative
refraction in the laminate. As a corollary to our approach of negative
refraction, we show how the laminate can be used to steer beams over large
angles for small changes in the incident angles (beam steering). Furthermore,
we clarify how the transmitted modes in the laminate can be switched on and off
by varying the angle of the incident wave by a small amount. Finally, we show
that the laminate can be used as a remarkably efficient high-pass frequency
filter. An appropriately designed laminate will reflect all plane waves from
quasi-static to a large frequency, incident at it from all angles except for a
small set of near-normal incidences. This will be true even if the homogeneous
medium is impedance matched with the laminate. Due to the similarities between
SH waves and EM waves it is expected that some or all of these results may also
apply to EM waves in a layered periodic dielectric.


title: Ion Polarization Scheme for MEIC

abstract:
  The choice of a figure 8 shape for the booster and collider rings of MEIC
opens wide possibilities for preservation of the ion polarization during beam
acceleration as well as for control of the polarization at the collider's
interaction points. As in the case of accelerators with Siberian snakes, the
spin tune is energy independent but is equal to zero instead of one half. The
figure-8 topology eliminates the effect of arcs on the spin motion. There
appears a unique opportunity to control the polarization of any particle
species including deuterons, using longitudinal fields of small integrated
strength (weak solenoids). Contrary to existing schemes, using weak solenoids
in figure-8 colliders, one can control the polarization at the interaction
points without essentially any effect on the beam's orbital characteristics. A
universal scheme for control of the polarization using weak solenoids provides
an elegant solution to the problem of ion acceleration completely eliminating
resonant beam depolarization. It allows one to easily adjust the polarization
in any direction at any orbital location, which becomes necessary when
transferring the beam from one ring into another or when measuring the
polarization by polarimeters. It also allows for an easy manipulation of the
spin direction at an interaction point during an experiment. The latter feature
allows one to set up a spin-flipping system with a spin reversal time of less
than a second. By compensating the coherent part of the zero-integer spin
resonance strength, which arises due to errors in alignment of the magnetic
element of the lattice, one can reduce the field integrals of the control
solenoids by a few orders of magnitude.


title:
Online Human Action Detection using Joint Classification-Regression
  Recurrent Neural Networks

abstract:
  Human action recognition from well-segmented 3D skeleton data has been
intensively studied and has been attracting an increasing attention. Online
action detection goes one step further and is more challenging, which
identifies the action type and localizes the action positions on the fly from
the untrimmed stream data. In this paper, we study the problem of online action
detection from streaming skeleton data. We propose a multi-task end-to-end
Joint Classification-Regression Recurrent Neural Network to better explore the
action type and temporal localization information. By employing a joint
classification and regression optimization objective, this network is capable
of automatically localizing the start and end points of actions more
accurately. Specifically, by leveraging the merits of the deep Long Short-Term
Memory (LSTM) subnetwork, the proposed model automatically captures the complex
long-range temporal dynamics, which naturally avoids the typical sliding window
design and thus ensures high computational efficiency. Furthermore, the subtask
of regression optimization provides the ability to forecast the action prior to
its occurrence. To evaluate our proposed model, we build a large streaming
video dataset with annotations. Experimental results on our dataset and the
public G3D dataset both demonstrate very promising performance of our scheme.


title:
Non-invertible transformations for the classification of
  differential-difference equations

abstract:
  We discuss aspects of the theory of non-invertible transformations which
enter in the problem of classification of diffe\-ren\-tial-difference equations
and, in particular, the notion of Miura type transformation. We introduce the
concept of non--Miura type linearizable transformation and we present
techniques which allow one to construct simple linearizable transformations and
help us to solve the classification problem. This theory is illustrated by the
example of a new integrable differential--difference equation depending on 5
lattice points, interesting from the viewpoint of the non-invertible
transformation which relate it to an Itoh--Narita--Bogoyavlensky equation.


title: Roaming form factors for the tricritical to critical Ising flow

abstract:
  We study the massless flows described by the staircase model introduced by
Al.B. Zamolodchikov through the analytic continuation of the sinh-Gordon
S-matrix, focusing on the renormalisation group flow from the tricritical to
the critical Ising model. We show that the properly defined roaming limits of
certain sinh-Gordon form factors are identical to the form factors of the order
and disorder operators for the massless flow. As a by-product, we also
construct form factors for a semi-local field in the sinh-Gordon model, which
can be associated with the twist field in the ultraviolet limiting free
massless bosonic theory.


title:
Pattern-Based Approach to the Workflow Satisfiability Problem with
  User-Independent Constraints

abstract:
  The fixed parameter tractable (FPT) approach is a powerful tool in tackling
computationally hard problems. In this paper, we link FPT results to classic
artificial intelligence (AI) techniques to show how they complement each other.
Specifically, we consider the workflow satisfiability problem (WSP) which asks
whether there exists an assignment of authorised users to the steps in a
workflow specification, subject to certain constraints on the assignment. It
was shown by Cohen et al. (JAIR 2014) that WSP restricted to the class of
user-independent constraints (UI), covering many practical cases, admits FPT
algorithms, i.e. can be solved in time exponential only in the number of steps
$k$ and polynomial in the number of users $n$. Since usually $k << n$ in WSP,
such FPT algorithms are of great practical interest. We present a new
interpretation of the FPT nature of the WSP with UI constraints giving a
decomposition of the problem into two levels. Exploiting this two-level split,
we develop a new FPT algorithm that is by many orders of magnitude faster than
the previous state-of-the-art WSP algorithm and also has only polynomial-space
complexity. We also introduce new pseudo-Boolean (PB) and Constraint
Satisfaction (CSP) formulations of the WSP with UI constraints which
efficiently exploit this new decomposition of the problem and raise the novel
issue of how to use general-purpose solvers to tackle FPT problems in a fashion
that meets FPT efficiency expectations. In our computational study, we
investigate, for the first time, the phase transition (PT) properties of the
WSP, under a model for generation of random instances. We show how PT studies
can be extended, in a novel fashion, to support empirical evaluation of scaling
of FPT algorithms.


title:
Metallicity and conductivity crossover in white light illuminated
  CH$_3$NH$_3$PbI$_3$ perovskite

abstract:
  The intrinsic d.c. electrical resistivity ($\rho$) - measurable on single
crystals only - is often the quantity first revealing the properties of a given
material. In the case of CH$_3$NH$_3$PbI$_3$ perovskite measuring $\rho$ under
white light illumination provides insight into the coexistence of extended and
shallow localized states (0.1 eV below the conduction band). The former ones
dominate the electrical conduction while the latter, coming from neutral
defects, serve as a long-lifetime charge carrier reservoir accessible for
charge transport by thermal excitation. Remarkably, in the best crystals the
electrical resistivity shows a metallic behaviour under illumination up to room
temperature, giving a new dimension to the material in basic physical studies.


title:
Separability of test fields equations on the C-metric background II.
  Rotating case and the Meissner effect

abstract:
  We present the separation of the Teukolsky master equation for the test field
of arbitrary spin on the background of the rotating C-metric. We also summarize
and simplify some known results about Debye potentials of these fields on type
D background. The equation for the Debye potential is also separated.
  Solving for the Debye potential of the electromagnetic field we show that on
the extremely rotating C-metric no magnetic field can penetrate through the
outer black hole horizon --- we thus recover the Meissner effect for the
C-metric.


title: Quantum Rotor Theory of Systems of Spin-2 Bosons

abstract:
  We consider quantum phases of tightly-confined spin-2 bosons in an external
field under the presence of rotationally-invariant interactions. Generalizing
previous treatments, we show how this system can be mapped onto a quantum rotor
model. Within the rotor framework, low-energy excitations about fragmented
states, which cannot be accessed within standard Bogoliubov theory, can be
obtained. In the spatially extended system in the thermodynamic limit there
exists a mean-field ground state degeneracy between a family of nematic states
for appropriate interaction parameters. It has been established that quantum
fluctuations lift this degeneracy through the mechanism of order-by-disorder
and select either a uniaxial or square-biaxial ground state. On the other hand,
in the full quantum treatment of the analogous single-spatial mode problem with
finite particle number it is known that, due to symmetry restoring
fluctuations, there is a unique ground state across the entire nematic region
of the phase diagram. Within the established rotor framework we investigate the
possible quantum phases under the presence of a quadratic Zeeman field, a
problem which has previously received little attention. By investigating wave
function overlaps we do not find any signatures of the order-by-disorder
phenomenon which is present in the continuum case. Motivated by this we
consider an alternative external potential which breaks less symmetry than the
quadratic Zeeman field. For this case we do find the phenomenon of
order-by-disorder in the fully quantum system. This is established within the
rotor framework and with exact diagonalization.


title:
Achieving Super-Resolution in Multi-Rate Sampling Systems via Efficient
  Semidefinite Programming

abstract:
  Super-resolution theory aims to estimate the discrete components lying in a
continuous space that constitute a sparse signal with optimal precision. This
work investigates the potential of recent super-resolution techniques for
spectral estimation in multi-rate sampling systems. It shows that, under the
existence of a common supporting grid, and under a minimal separation
constraint, the frequencies of a spectrally sparse signal can be exactly
jointly recovered from the output of a semidefinite program (SDP). The
algorithmic complexity of this approach is discussed, and an equivalent SDP of
minimal dimension is derived by extending the Gram parametrization properties
of sparse trigonometric polynomials.


title:
An observational study of dust nucleation in Mira ($o$ Ceti): I.
  Variable features of AlO and other Al-bearing species

abstract:
  Context: Dust is efficiently produced by cool giant stars, but the
condensation of inorganic dust is poorly understood. Aims: Identify and
characterize aluminum bearing species in the circumstellar gas of Mira ($o$
Ceti) in order to elucidate their role in the production of Al$_2$O$_3$ dust.
Methods: Multiepoch spectral line observations at (sub-)millimeter,
far-infrared, and optical wavelengths including: maps with ALMA which probe the
gas distribution in the immediate vicinity of the star at ~30 mas; observations
with ALMA, APEX, and Herschel in 2013-2015 for studying cycle and inter-cycle
variability of the rotational lines of Al bearing molecules; optical records as
far back as 1965 to examine variations in electronic transitions over time
spans of days to decades; and velocity measurements and excitation analysis of
the spectral features which constrain the physical parameters of the gas.
Results: Three diatomic molecules AlO, AlOH, and AlH, and atomic Al I are the
main observable aluminum species in Mira, although a significant fraction of
aluminum might reside in other species that have not yet been identified.
Strong irregular variability in the (sub-)millimeter and optical features of
AlO (possibly the direct precursor of Al$_2$O$_3$) indicates substantial
changes in the excitation conditions, or varying abundance that is likely
related to shocks in the star. The inhomogeneous distribution of AlO might
influence the spatial and temporal characteristics of dust production.
Conclusions: We are unable to quantitatively trace aluminum depletion from the
gas, but the rich observational material constrains time dependent chemical
networks. Future improvements should include spectroscopic characterization of
higher aluminum oxides, coordinated observations of dust and gas species at
different variability phases, and tools to derive abundances in shock excited
gas.