title: TruthDiscover: Resolving Object Conflicts on Massive Linked Data

abstract:
  Considerable effort has been made to increase the scale of Linked Data.
However, because of the openness of the Semantic Web and the ease of extracting
Linked Data from semi-structured sources (e.g., Wikipedia) and unstructured
sources, many Linked Data sources often provide conflicting objects for a
certain predicate of a real-world entity. Existing methods cannot be trivially
extended to resolve conflicts in Linked Data because Linked Data has a
scale-free property. In this demonstration, we present a novel system called
TruthDiscover, to identify the truth in Linked Data with a scale-free property.
First, TruthDiscover leverages the topological properties of the Source Belief
Graph to estimate the priori beliefs of sources, which are utilized to smooth
the trustworthiness of sources. Second, the Hidden Markov Random Field is
utilized to model interdependencies among objects for estimating the trust
values of objects accurately. TruthDiscover can visualize the process of
resolving conflicts in Linked Data. Experiments results on four datasets show
that TruthDiscover exhibits satisfactory accuracy when confronted with data
having a scale-free property.


title: Bootstrap percolation on geometric inhomogeneous random graphs

abstract:
  Geometric inhomogeneous random graphs (GIRGs) are a model for scale-free
networks with underlying geometry. We study bootstrap percolation on these
graphs, which is a process modelling the spread of an infection of vertices
starting within a (small) local region. We show that the process exhibits a
phase transition in terms of the initial infection rate in this region. We
determine the speed of the process in the supercritical case, up to lower order
terms, and show that its evolution is fundamentally influenced by the
underlying geometry. For vertices with given position and expected degree, we
determine the infection time up to lower order terms. Finally, we show how this
knowledge can be used to contain the infection locally by removing relatively
few edges from the graph. This is the first time that the role of geometry on
bootstrap percolation is analysed mathematically for geometric scale-free
networks.


title:
Performances piecewise defined functions in analytic form,
  prime-counting function, $\xi$ sets

abstract:
  The article discusses the representation of discrete functions defined in an
analytic form without the use of approximations, namely the Heaviside function,
identity function, the Dirac delta function and the prime-counting function.
Also in the article introduced and considered a new type of sets ($\xi$ set) by
analogy taken from finding the sum of a number of grants and other
contradictions in mathematics and physics. With the help of $\xi$ sets
interpreted Russell's paradox in the system of axioms of naive set theory.


title: Graph theoretic uncertainty and feasibility

abstract:
  We expand upon a graph theoretic set of uncertainty principles with tight
bounds for difference estimators acting simultaneously in the graph domain and
the frequency domain. We show that the eigenfunctions of a modified graph
Laplacian and a modified normalized graph Laplacian operator dictate the upper
and lower bounds for the inequalities. Finally, we establish the feasibility
region of difference estimator values in $\mathbb{R}^2$.


title:
On the dynamic pull-in instability in a mass-spring model of
  electrostatically actuated MEMS devices

abstract:
  In this work we study the mass-spring system \begin{equation} \ddot x +
\alpha \dot x + x = - \frac{\lambda} {(1+x)^{2}}, \label{e:inertia}
\end{equation} which is a simplified model for an electrostatically actuated
MEMS device. The static pull-in value is $\lambda^{*}=\frac{4}{27}$, which
corresponds to the largest value of $\lambda$ for which there exists at least
one stationary solution. For $\lambda > \lambda^{*}$ there are no stationary
solutions and $x(t)$ achieves the value $-1$ in finite time: {\it touchdown}
occurs. We establish the existence of a dynamic pull-in value
$\lambda_{d}^{*}(\alpha) \in (0, \lambda^{*})$, defined for $\alpha \in
[0,\infty)$, which is a threshold in the sense that $x(t)$ approaches a stable
stationary solution as $t \to \infty$ for $0 < \lambda <
\lambda_{d}^{*}(\alpha)$, while touchdown occurs for $\lambda >
\lambda_{d}^{*}(\alpha)$. This dynamic pull-in value is a continuous, strictly
increasing function of $\alpha$ and $\lim_{\alpha\to\infty}
\lambda_{d}^{*}(\alpha)= \lambda^{*}$.


title:
A Pragmatic Smoothing Method for Improving the Quality of the Results in
  Atomic Spectroscopy

abstract:
  A new smoothing method for the improvement on the identification and
quantification of spectral functions based on the previous knowledge of the
signals that are expected to be quantified, is presented. These signals are
used as weighted coefficients in the smoothing algorithm. This smoothing method
was conceived to be applied in atomic and nuclear spectroscopies preferably to
these techniques where net counts are proportional to acquisition time, such as
particle induced X-ray emission (PIXE) and other X-ray fluorescence
spectroscopic methods, etc. This algorithm, when properly applied, does not
distort the form nor the intensity of the signal, so it is well suited for all
kind of spectroscopic techniques. This method is extremely effective at
reducing high-frequency noise in the signal much more efficient than a single
rectangular smooth of the same width. As all of smoothing techniques, the
proposed method improves the precision of the results, but in this case we
found also a systematic improvement on the accuracy of the results. We still
have to evaluate the improvement on the quality of the results when this method
is applied over real experimental results. We expect better characterization of
the net area quantification of the peaks, and smaller Detection and
Quantification Limits.
  We have applied this method to signals that obey Poisson statistics, but with
the same ideas and criteria, it could be applied to time series. In a general
case, when this algorithm is applied over experimental results, also it would
be required that the sought characteristic functions, required for this
weighted smoothing method, should be obtained from a system with strong
stability. If the sought signals are not perfectly clean, this method should be
carefully applied


title:
Extracellular stimulation of nerve cells with electric current spikes
  induced by voltage steps

abstract:
  A new stimulation paradigm is presented for the stimulation of nerve cells by
extracellular electric currents. In the new paradigm stimulation is achieved
with the current spike induced by a voltage step whenever the voltage step is
applied to a live biological tissue. By experimental evidence and theoretical
arguments, it is shown that this spike is well suited for the stimulation of
nerve cells. Stimulation of the human tongue is used for proof of principle.
Charge injection thresholds are measured for various voltages. The time-profile
of the current spike used in the experiment has a half-width of about 1
microsecond. The decay of the spike is non-exponential. The spike has at least
three distinctly different phases. A Maxwell phase is followed by a
charge-rearrangement phase. Charging of cell membranes is completed in a third
phase. All three phases contribute to depolarization or hyperpolarization of
cell membranes. Due to the short duration of the spike the charge transfer is
very small. The activation time (time of no return) of nerve cell membranes
leading to an action potential is measured and found to be unexpectedly short.
It can become as short as 3 microseconds for a voltage step of 10 V or higher.


title: Aggregated 2D Range Queries on Clustered Points

abstract:
  Efficient processing of aggregated range queries on two-dimensional grids is
a common requirement in information retrieval and data mining systems, for
example in Geographic Information Systems and OLAP cubes. We introduce a
technique to represent grids supporting aggregated range queries that requires
little space when the data points in the grid are clustered, which is common in
practice. We show how this general technique can be used to support two
important types of aggregated queries, which are ranked range queries and
counting range queries. Our experimental evaluation shows that this technique
can speed up aggregated queries up to more than an order of magnitude, with a
small space overhead.


title:
On the integral functional equations: On the integral d'Alembert's and
  Wilson's functional equations

abstract:
  Let $G$ be a locally compact group, and let $K$ be a compact subgroup of $G$.
Let $\mu : G\longrightarrow\mathbb{C}\backslash\{0\}$ be a character of $G$. In
this paper, we deal with the integral equations $$W_{\mu}(K):\;
\;\int_{K}f(xkyk^{-1})dk+\mu(y)\int_{K}f(xky^{-1}k^{-1})dk=2f(x)g(y),$$ and
$$D_{\mu}(K):\;
\;\int_{K}f(xkyk^{-1})dk+\mu(y)\int_{K}f(xky^{-1}k^{-1})dk=2f(x)f(y)$$ for all
$x, y\in G$ where $f, g: G\longrightarrow \mathbb{C}$, to be determined, are
complex continuous functions on $G$.
  When $K\subset Z(G)$, the center of $G$, $D_{\mu}(K)$ reduces to the new
version of d'Almbert's functional equation $f(xy)+\mu(y)f(xy^{-1})=2f(x)f(y)$,
recently studied by Davison [18] and Stetk{\ae}r [35].
  We derive the following link between the solutions of $W_{\mu}(K)$ and
$D_{\mu}(K)$ in the following way :
  If $(f,g)$ is a solution of equation $W_{\mu}(K)$ such that
$C_{K}f=\int_{K}f(kxk^{-1})d\omega_{K}(k)\neq 0$ then $g$ is a solution of
$D_{\mu}(K)$. This result is used to establish the superstability problem of
$W_{\mu}(K)$. In the case where $(G,K)$ is a central pair, we show that the
solutions are expressed by means of $K$-spherical functions and related
functions. Also we give explicit formulas of solutions of $D_{\mu}(K)$ in terms
of irreducible representations of $G$. These formulas generalize Euler's
formula $\cos(x)=\frac{e^{ix}+e^{-ix}}{2}$ on $G=\mathbb{R}$.


title: A class of functional equations on monoids

abstract:
  In \cite{05} B. Ebanks and H. Stetk{\ae}r obtained the solutions of the
functional equation $f(xy)-f(\sigma(y)x)=g(x)h(y)$ where $\sigma$ is an
involutive automorphism and $f,g,h$ are complex-valued functions, in the
setting of a group $G$ and a monoid $M$.
  Our main goal is to determine the complex-valued solutions of the following
more general version of this equation, viz $f(xy)-\mu(y)f(\sigma(y)x)=g(x)h(y)$
where $\mu: G\longrightarrow \mathbb{C}$ is a multiplicative function such that
$\mu(x\sigma(x))=1$ for all $x\in G$. As an application we find the
complex-valued solutions $(f,g,h)$ on groups of the equation
$f(xy)+\mu(y)g(\sigma(y)x)=h(x)h(y)$.


title: On the symmetric squares of complex and quaternionic projective space

abstract:
  The problem of computing the integral cohomology ring of the symmetric square
of a topological space has been of interest since the 1930s, but limited
progress has been made on the general case until recently. In this work we
offer a solution for the complex and quaternionic projective spaces $KP^n$, by
taking advantage of their rich geometrical structure. Our description is in
terms of generators and relations, and our methods entail ideas that have
appeared in the literature of quantum chemistry, theoretical physics, and
combinatorics. We deal first with the case $KP^\infty$, and proceed by
identifying the truncation required for passage to finite n. The calculations
rely upon a ladder of long exact cohomology sequences, which arises by
comparing cofibrations associated to the diagonals of the symmetric square and
the corresponding Borel construction. The cofibrations involve classic
configuration spaces of unordered pairs of 1-dimensional subspaces of
$K^{n+1}$, and their one-point compactifications; the latter are identified as
Thom spaces by combining Lowdin's symmetric orthogonalisation process (and its
quaternionic extension) with a dash of Pin geometry. The ensuing integral
cohomology rings may be conveniently expressed using generalised Fibonacci
polynomials. By way of validation, we note that our conclusions are compatible
with mod 2 computations of Nakaoka and with homological results of Milgram.


title: Numerical Solution of a Nonlinear Integro-Differential Equation

abstract:
  An algorithm for the numerical solution of a nonlinear integro-differential
equation arising in the single-species annihilation reaction $A + A
\rightarrow\varnothing$ modeling is discussed. Finite difference method
together with the linear approximation of the unknown function is considered.
For divergent integrals presented in the equation for dimension $d=2$ a
regularization is used. Some numerical results are presented.


title:
Holographic superconductivity in the presence of dark matter: basic
  issues

abstract:
  The holographic approach to study strongly coupled superconductors in the
presence of dark matter is reviewed. We discuss the influence of dark matter on
the superconducting transition temperature of both s-wave and p-wave
holographic superconductors. The upper critical field, coherence length,
penetration depth of holographic superconductors as well as the metal-insulator
transitions have also been analysed. Issues related to the validity of AdS/CFT
correspondence for the description of superconductors studied in the laboratory
and possible experiments directed towards the detection of dark matter are
discussed. In doing so we shall compare our assumptions and assertions with
those generally accepted in the elementary particle experiments aimed at the
detection of dark matter particles.


title:
A Study of Fractional Schrodinger Equation-composed via Jumarie
  fractional derivative

abstract:
  One of the motivations for using fractional calculus in physical systems is
due to fact that many times, in the space and time variables we are dealing
which exhibit coarse-grained phenomena, meaning that infinitesimal quantities
cannot be placed arbitrarily to zero-rather they are non-zero with a minimum
length. Especially when we are dealing in microscopic to mesoscopic level of
systems. Meaning if we denote x the point in space and t as point in time; then
the differentials dx (and dt) cannot be taken to limit zero, rather it has
spread. A way to take this into account is to use infinitesimal quantities as
(\Deltax)^\alpha (and (\Deltat)^\alpha) with 0<\alpha<1, which for very-very
small \Deltax (and \Deltat); that is trending towards zero, these 'fractional'
differentials are greater that \Deltax (and \Deltat). That is
(\Deltax)^\alpha>\Deltax. This way defining the differentials-or rather
fractional differentials makes us to use fractional derivatives in the study of
dynamic systems. In fractional calculus the fractional order trigonometric
functions play important role. The Mittag-Leffler function which plays
important role in the field of fractional calculus; and the fractional order
trigonometric functions are defined using this Mittag-Leffler function. In this
paper we established the fractional order Schrodinger equation-composed via
Jumarie fractional derivative; and its solution in terms of Mittag-Leffler
function with complex arguments and derive some properties of the fractional
Schrodinger equation that are studied for the case of particle in one
dimensional infinite potential well.


title:
On Hermite-Hadamard Inequalities for differentiable $\lambda$-preinvex
  functions via Riemann-Liouville Fractional Integrals

abstract:
  In this paper, we consider a new class of convex functions which is called
$\lambda$-preinvex functions. We prove several Hermite-Hadamard type
inequalities for differentiable $\lambda$-preinvex functions via Fractional
Integrals. Some special cases are also discussed.


title:
A new technique for ultra-fast physical random number generation using
  optical chaos

abstract:
  In this paper, we numerically demonstrate a new extraction scheme for
generating ultra-fast physically random sequence of bits. For this purpose, we
utilize a dual-channel optical chaos source with suppressed time delayed (TD)
signature in both the intensity and the phase of its two channels. The proposed
technique uses M 1-bit analog-to-digital converters (ADCs) to compare the level
of the chaotic intensity signal at time t with its levels after incommensurable
delay-interval Tm, where m = {1,2,...,M}. The binary output of each 1-bit ADC
is then sampled by a positive-edge-triggered D flip-flop. The clock sequence
applied to the flip-flops is relatively delayed such that the rising edge of
the clock triggering the m flip-flop precedes the rising edge of the clock of a
subsequent m+1 flip-flop by a fixed period. The outputs of all flip-flops are
then combined by means of a parity-check logic. Numerical simulations are
carried out using values of parameters at which TD signature is suppressed for
chosen values of setup parameters. The 15 statistical tests in Special
Publication 800-22 from NIST are applied to the generated random bits in order
to examine the randomness quality of these bits for different values of M. The
results show that all tests are passed from M = 1 to M = 39 at sampling rate up
to 34.5 GHz which indicates that the maximum generation rate of random bits is
2.691 Tb/sec using a chaotic source of single VCSEL and without employing any
pre-processing techniques.


title:
On Paley-type and Hausdorff-Young-Paley-type inequalities for
  generalized Gegenbauer expansions

abstract:
  We establish Paley-type and Hausdorff-Young-Paley-type inequalities for
generalized Gegenbauer expansions.


title: The test of the electronics system for the BESIII ETOF upgrade

abstract:
  It is proposed to upgrade the endcap time-of-flight (ETOF) of the Beijing
Spectrometer III (BESIII) with multi-gap resistive plate chamber (MRPC), aiming
at overall time resolution about 80 ps. After the entire electronics system is
ready, some experiments, such as heat radiating, irradiation hardness and
large-current beam tests,are carried out to certify the electronics'
reliability and stability. The on-detector test of the electronics is also
performed with the beam at BEPCII E3 line, the test results indicate that the
electronics system fulfills its design requirements.


title: Optimal dictionary for least squares representation

abstract:
  Dictionaries are collections of vectors used for representations of random
vectors in Euclidean spaces. Recent research on optimal dictionaries is focused
on constructing dictionaries that offer sparse representations, i.e.,
$\ell_0$-optimal representations. Here we consider the problem of finding
optimal dictionaries with which representations of samples of a random vector
are optimal in an $\ell_2$-sense: optimality of representation is defined as
attaining the minimal average $\ell_2$-norm of the coefficients used to
represent the random vector. With the help of recent results on rank-$1$
decompositions of symmetric positive semidefinite matrices, we provide an
explicit description of $\ell_2$-optimal dictionaries as well as their
algorithmic constructions in polynomial time.


title:
A New Approach to Inverting Backscatter and Extinction from
  Photon-Limited Lidar Observations

abstract:
  Atmospheric lidar observations provide a unique capability to directly
observe the vertical column of cloud and aerosol scattering properties.
Detector and solar background noise, however, hinder the ability of lidar
systems to provide reliable backscatter and extinction cross-section estimates.
Standard methods for solving this inverse problem are most effective with high
signal-to-noise ratio observations that are only available at low-resolution in
uniform scenes. This paper describes a novel method for solving the inverse
problem with high-resolution, lower signal-to-noise ratio observations that are
effective in non-uniform scenes. The novelty is twofold. First, the inference
of the backscatter and extinction are done on images, whereas current lidar
algorithms only use the information content of single profiles. Hence, the
latent spatial and temporal information in the noisy images are utilized to
infer the cross-sections. Second, the noise associated with photon-counting
lidar observations can be modeled using a Poisson distribution, and
state-of-the-art tools for solving Poisson inverse problems are adapted to the
atmospheric lidar problem. It is demonstrated through photon-counting High
Spectral Resolution Lidar (HSRL) simulations that the proposed algorithm yield
inverted backscatter and extinction cross-sections (per unit volume) with
smaller Mean Squared Error (MSE) values at higher spatial and temporal
resolutions, compared to the standard approach. Two case studies of real
experimental data are also provided where the proposed algorithm is applied on
HSRL observations and the inverted backscatter and extinction cross-sections
are compared against the standard approach.


title:
Searching for a continuum limit in causal dynamical triangulation
  quantum gravity

abstract:
  We search for a continuum limit in the causal dynamical triangulation (CDT)
approach to quantum gravity by determining the change in lattice spacing using
two independent methods. The two methods yield similar results that may
indicate how to tune the relevant couplings in the theory in order to take a
continuum limit.


title: The hard-sphere model of strongly interacting fermion systems

abstract:
  The formalism based on Correlated Basis Functions (CBF) and the
cluster-expansion technique has been recently employed to derive an effective
interaction from a realistic nuclear Hamiltonian. One of the main objectives of
the work described in this Thesis is establishing the accuracy of this novel
approach--that allows to combine the flexibility of perturbation theory in the
basis of eigenstates of the noninteracting system with a realistic description
of short-range correlations in coordinate space--by focusing on the hard-sphere
fermion system.
  As a first application of the formalism, the quasiparticle properties of hard
spheres of degeneracy four have been determined from the two-point Green's
function. The calculation has been performed carrying out a perturbative
expansion of the self-energy, up to the second order in the CBF effective
interaction. The main results of this study are the momentum distributions, the
quasiparticle spectra and their description in terms of effective mass.
  The investigation of the hard-sphere fermion fluid has been extended to study
the shear viscosity and thermal conductivity coefficients of the system with
degeneracy two, that can be regarded as a model of pure neutron matter. The
resulting transport coefficients show a strong sensitivity to the quasiparticle
effective mass, reflecting the effect of second order contributions to the
self-energy which are not taken into account in nuclear matter studies
available in the literature. The difference between first and second order
results is likely to play an important role in astrophysical applications and
needs to be carefully investigated extending our analysis to nuclear matter.


title: A novel learning-based frame pooling method for Event Detection

abstract:
  Detecting complex events in a large video collection crawled from video
websites is a challenging task. When applying directly good image-based feature
representation, e.g., HOG, SIFT, to videos, we have to face the problem of how
to pool multiple frame feature representations into one feature representation.
In this paper, we propose a novel learning-based frame pooling method. We
formulate the pooling weight learning as an optimization problem and thus our
method can automatically learn the best pooling weight configuration for each
specific event category. Experimental results conducted on TRECVID MED 2011
reveal that our method outperforms the commonly used average pooling and max
pooling strategies on both high-level and low-level 2D image features.


title:
Magnetic structures and magnetoelastic coupling of Fe-doped hexagonal
  manganites LuMn1-xFexO3 (0 < x < 0.3)

abstract:
  We have studied the crystal and magnetic structures of Fe-doped hexagonal
manganites LuMn1-xFexO3 (x = 0, 0.1, 0.2, and 0.3) by using bulk magnetization
and neutron powder diffraction methods. The samples crystalize consistently in
a hexagonal structure and maintain the space group P63cm from 2 to 300 K. The
N\'eel temperature TN increases continuously with increasing Fe-doping. In
contrast to a single {\Gamma}4 representation in LuMnO3, the magnetic ground
state of the Fe-doped samples can only be described with a spin configuration
described by a mixture of {\Gamma}3 (P63'cm') and {\Gamma}4 (P63'c'm)
representations, whose contributions have been quantitatively estimated. The
drastic effect of Fe-doping is highlighted by composition-dependent spin
reorientations. A phase diagram of the entire composition series is proposed
based on the present results and those reported in literature. Our result
demonstrates the importance of tailoring compositions in increasing magnetic
transition temperatures of multiferroic systems.


title: How to Cut Corners and Get Bounded Convex Curvature

abstract:
  We describe an algorithm for solving an important geometric problem arising
in computer-aided manufacturing. When cutting away a region from a solid piece
of material -- such as steel, wood, ceramics, or plastic -- using a rough tool
in a milling machine, sharp convex corners of the region cannot be done
properly, but have to be left for finer tools that are more expensive to use.
We want to determine a toolpath that maximizes the use of the rough tool. In
order to formulate the problem in mathematical terms, we introduce the notion
of bounded convex curvature. A region of points in the plane $Q$ has
\emph{bounded convex curvature} if for any point $x\in\partial Q$, there is a
unit disk $U$ and $\varepsilon>0$ such that $x\in \partial U$ and all points in
$U$ within distance $\varepsilon$ from $x$ are in $Q$. This translates to
saying that as we traverse the boundary $\partial Q$ with the interior of $Q$
on the left side, then $\partial Q$ turns to the left with curvature at most
$1$. There is no bound on the curvature where $\partial Q$ turns to the right.
Given a region of points $P$ in the plane, we are now interested in computing
the maximum subset $Q\subseteq P$ of bounded convex curvature. The difference
in the requirement to left- and right-curvature is a natural consequence of
different conditions when machining convex and concave areas of $Q$. We devise
an algorithm to compute the unique maximum such set $Q$, when the boundary of
$P$ consists of $n$ line segments and circular arcs of arbitrary radii. In the
general case where $P$ may have holes, the algorithm runs in time $O(n^2)$ and
uses $O(n)$ space. If $P$ is simply-connected, we describe a faster $O(n\log
n)$ time algorithm.


title:
Extreme Contractility and Torsional Compliance of Soft Ribbons under
  High Twist

abstract:
  We investigate experimentally and model the mechanical response of a soft
Hookean ribbon submitted to large twist $\eta$ and longitudinal tension $T$,
under clamped boundary conditions. We derive a formula for the torque $M$ using
the \FvK equations up to third order in twist, incorporating a twist-tension
coupling. In the stable helicoid regime, quantitative agreement with
experimental data is obtained. When twisted above a critical twist $\eta_L(T)$,
ribbons develop wrinkles and folds which modify qualitatively the mechanical
behavior. We show a surprisingly large longitudinal contraction upon twist,
reminiscent of a Poynting effect, and a much lower torsional stiffness. Far
from threshold, we identify two regimes depending on the applied $T$. In a
high-$T$ regime, we find that the torque scales as $\eta\cdot T$ and the
contraction as $\eta^2$, in agreement with a far from threshold analysis where
compression and bending stresses are neglected. In a low-$T$ regime, the
contraction still scales as $\eta^2$ but the torque appears $T$-independent and
linear with $\eta$. We argue that the large curvature of the folds now
contribute significantly to the torque. This regime is discussed in the context
of asymptotic isometry for very thin plates submitted to vanishing tension but
large change of shape, as in crumpling.


title: Realising a quantum absorption refrigerator with an atom-cavity system

abstract:
  An autonomous quantum thermal machine comprising a trapped atom or ion placed
inside an optical cavity is proposed and analysed. Such a machine can operate
as a heat engine whose working medium is the quantised atomic motion, or as an
absorption refrigerator which cools without any work input. Focusing on the
refrigerator mode, we predict that it is possible with state-of-the-art
technology to cool a trapped ion almost to its motional ground state using a
thermal light source such as sunlight. We nonetheless find that a laser or
similar reference system is necessary to stabilise the cavity frequencies.
Furthermore, we establish a direct and heretofore unacknowledged connection
between the abstract theory of quantum absorption refrigerators and practical
sideband cooling techniques. We also highlight and clarify some assumptions
underlying several recent theoretical studies on self-contained quantum engines
and refrigerators. Our work indicates that cavity quantum electrodynamics is a
promising and versatile experimental platform for the study of autonomous
thermal machines in the quantum domain.


title:
Fluctuations in Charged Particle Multiplicities in Relativistic
  Heavy-Ion Collisions

abstract:
  Multiplicity distributions of charged particles and their event-by-event
fluctuations have been compiled for relativistic heavy-ion collisions from the
available experimental data at Brookhaven National Laboratory and CERN and also
by the use of an event generator. Multiplicity fluctuations are sensitive to
QCD phase transition and to the presence of critical point in the QCD phase
diagram. In addition, multiplicity fluctuations provide baselines for other
event-by-event measurements. Multiplicity fluctuation expressed in terms of the
scaled variance of the multiplicity distribution is an intensive quantity, but
is sensitive to the volume fluctuation of the system. The importance of the
choice of narrow centrality bins and the corrections of centrality bin width
effect for controlling volume fluctuations have been discussed. It is observed
that the mean and width of the multiplicity distributions monotonically
increase as a function of increasing centrality at all collision energies,
whereas the multiplicity fluctuations show minimal variations with centrality.
The beam energy dependence shows that the multiplicity fluctuations have a slow
rise at lower collision energies and remain constant at higher energies.


title:
Constraining the Existence of Magnetic Monopoles by Dirac-Dual Electric
  Charge Renormalization Effect Under the Planck Scale Limit

abstract:
  It was suggested by dimensional analysis that there exists a limit called the
Planck energy scale coming close to which the gravitational effects of physical
processes would inflate and struggle for equal rights so as to spoil the
validity of pure non-gravitational physical theories that governed well below
the Planck energy. Near the Planck scale, the Planck charges, Planck currents,
or Planck parameters can be defined and assigned to physical quantities such as
the single particle electric charge and magnetic charge as the ceiling value
obeyed by the low energy ordinary physics. The Dirac electric-magnetic charge
quantization relation as one form of electric-magnetic duality dictates that,
the present low value electric charge corresponds to a huge magnetic charge
value already passed the Planck limit so as to render theories of magnetic
monopoles into the strong coupling regime, and vice versa, that small and
tractable magnetic charge values correspond to huge electric charge values. It
suggests that for theoretic models in which the renormalization group equation
provides rapid growth for the running electric coupling constant, it is easier
for the dual magnetic monopoles to emerge at lower energy scales. Allowing
charges to vary with the Dirac electric-magnetic charge quantization relation
while keeping values under the Planck limit informs that the magnetic charge
value drops below the Planck ceiling value into the manageable region when the
electric coupling constant grows to one fourth at a model dependent energy
scale, and continues dropping towards half the value of the Planck magnetic
charge as the electric coupling constant continues growing at the model
dependent rate towards one near Planck energy scale.


title: The 2PI effective action at four loop order in $\varphi^4$ theory

abstract:
  It is well known that perturbative pressure calculations show poor
convergence. Calculations using a two particle irreducible (2PI) effective
action show improved convergence at the 3 loop level, but no calculations have
been done at 4 loops. We consider the 2PI effective theory for a symmetric
scalar theory with quartic coupling in 4-dimensions. We calculate the pressure
and two different non-perturbative vertices as functions of coupling and
temperature. Our results show that the 4 loop contribution can become larger
than the 3 loop term when the coupling is large. This indicates a breakdown of
the 2PI approach, and the need for higher order $n$PI approximations. In
addition, our results demonstrate the renormalizability of 2PI calculations at
the 4 loop level. This is interesting because the counterterm structure of the
2PI theory at 4 loops is different from the structure at $n\le 3$ loops. Two
vertex counterterms are required at the 4 loop level, but not at lower loop
order. This unique feature of the 2PI theory has not previously been verified
numerically.


title: Homogeneous Beta-type functions

abstract:
  All beta-type functions, which are p-homogeneous, are determined. Applying
this result, we show that a beta-type function is a homogeneous mean iff it is
the harmonic one. A reformulation of a result due to Heuvers in terms of a
Cauchy difference and the harmonic mean is given.


title: Prospects of probing quintessence with HI 21-cm intensity mapping survey

abstract:
  We investigate the prospect of constraining scalar field dark energy models
using HI 21-cm intensity mapping surveys. We consider a wide class of coupled
scalar field dark energy models whose predictions about the background
cosmological evolution are different from the $\Lambda$CDM predictions by a few
percent. We find that these models can be statistically distinguished from
$\Lambda$CDM through their imprint on the 21-cm angular power spectrum. At the
fiducial $z= 1.5$, corresponding to a radio interferometric observation of the
post-reionization HI 21 cm observation at frequency $568 \rm MHz$, these models
can infact be distinguished from the $\Lambda$CDM model at $ {\rm SNR }> 3
\sigma$ level using a 10,000 hr radio observation distributed over 40 pointings
of a SKA1-mid like radio-telescope. We also show that tracker models are more
likely to be ruled out in comparison with $\Lambda$CDM than the thawer models.
Future radio observations can be instrumental in obtaining tighter constraints
on the parameter space of dark energy models and supplement the bounds obtained
from background studies.


title: Shape programming for narrow ribbons of nematic elastomers

abstract:
  Using the theory of $\Gamma$-convergence, we derive from three-dimensional
elasticity new one-dimensional models for non-Euclidean elastic ribbons, i.e.
ribbons exhibiting spontaneous curvature and twist. We apply the models to
shape-selection problems for thin films of nematic elastomers with twist and
splay-bend texture of the nematic director. For the former, we discuss the
possibility of helicoid-like shapes as an alternative to spiral ribbons.


title: Observation of quantum fingerprinting beating the classical limit

abstract:
  Quantum communication has historically been at the forefront of advancements,
from fundamental tests of quantum physics to utilizing the quantum-mechanical
properties of physical systems for practical applications. In the field of
communication complexity, quantum communication allows the advantage of an
exponential reduction in the information transmitted over classical
communication to accomplish distributed computational tasks. However, to date,
demonstrating this advantage in a practical setting continues to be a central
challenge. Here, we report an experimental demonstration of a quantum
fingerprinting protocol that for the first time surpasses the ultimate
classical limit to transmitted information. Ultra-low noise superconducting
single-photon detectors and a stable fibre-based Sagnac interferometer are used
to implement a quantum fingerprinting system that is capable of transmitting
less information than the classical proven lower bound over 20 km standard
telecom fibre for input sizes of up to two Gbits. The results pave the way for
experimentally exploring the advanced features of quantum communication and
open a new window of opportunity for research in communication complexity and
testing the foundations of physics.


title:
Quality of the Peccei-Quinn symmetry in the Aligned QCD Axion and
  Cosmological Implications

abstract:
  We show that the required high quality of the Peccei-Quinn symmetry can be
naturally explained in the aligned QCD axion models where the QCD axion arises
from multiple axions with decay constants much smaller than the axion window,
e.g., around the weak scale. Even in the presence of general Planck-suppressed
Peccei-Quinn symmetry breaking operators, the effective strong CP phase remains
sufficiently small in contrast to the standard axion models without the
alignment. The QCD axion potential has small or large modulations due to the
symmetry breaking operators, which can significantly affect the axion
cosmology. When the axions are trapped in different minima, domain walls appear
and their scaling behavior suppresses the axion isocurvature perturbations at
super-horizon scales. Our scenario predicts many axions and saxions coupled to
gluons, and they may be searched for at collider experiments. In particular,
the recently found diphoton excess at 750 GeV could be due to one of such
(s)axions.


title:
The Ext group in the categories of topological abelian groups and
  topological vector spaces

abstract:
  This paper is devoted to the study of the group ${\rm Ext} (G,H)$ of all
extensions of topological abelian groups $0\to H\to X\to G\to 0$ and the group
${\rm Ext}_{TVS} (Z,Y)$ of all extensions of topological vector spaces $0\to
Y\to X\to Z\to 0$. We focus on their behaviour under taking products, countable
coproducts, dense subgroups and open subgroups. Finally, we apply the obtained
properties to formulate in a more general setting some known results in the
category of locally compact abelian groups and to determine conditions in which
being a topological vector space is a three space property.


title: A survey on mixed spin P-fields

abstract:
  This is a survey on the mixed spin P-fields (MSP fields for short) theory
which provides a platform to understand the phase transition between
Gromov-Witten theory of quintic CY 3-folds and Landau-Ginzburg theory of the
corresponding quintic polynomials. It discusses key ideas that lead to the
definition of MSP fields and how moduli of stable maps to the quintic and that
of 5-spin curves appear in the moduli of MSP fields. It also explains some
properties of the moduli of MSP fields such as the cosection localisation, the
properness of the degeneracy locus, and a torus action on the moduli.. Some
vanishings arising from the torus action provide polynomial relations among
GW-invarants and FJRW-invaraints which give an effective algorithm for the
computation of those invariants. Some examples of computations of genus 1 low
degree of GW invariants are provided.


title: Monoids with absorbing elements and their associated algebras

abstract:
  Combinatorial and topological aspects of monoids with an absorbing element
and their associated algebras are considered. Phd thesis.


title:
Quality and Cost of Deterministic Network Calculus - Design and
  Evaluation of an Accurate and Fast Analysis

abstract:
  Networks are integral parts of modern safety-critical systems and
certification demands the provision of guarantees for data transmissions.
Deterministic Network Calculus (DNC) can compute a worst-case bound on a data
flow's end-to-end delay. Accuracy of DNC results has been improved steadily,
resulting in two DNC branches: the classical algebraic analysis and the more
recent optimization-based analysis. The optimization-based branch provides a
theoretical solution for tight bounds. Its computational cost grows, however,
(possibly super-)exponentially with the network size. Consequently, a heuristic
optimization formulation trading accuracy against computational costs was
proposed. In this paper, we challenge optimization-based DNC with a new
algebraic DNC algorithm.
  We show that: (i) no current optimization formulation scales well with the
network size and (ii) algebraic DNC can be considerably improved in both
aspects, accuracy and computational cost. To that end, we contribute a novel
DNC algorithm that transfers the optimization's search for best attainable
delay bounds to algebraic DNC. It achieves a high degree of accuracy and our
novel efficiency improvements reduce the cost of the analysis dramatically. In
extensive numerical experiments, we observe that our delay bounds deviate from
the optimization-based ones by only 1.142% on average while computation times
simultaneously decrease by several orders of magnitude.


title: Quasinormal modes of relativistic stars and interacting fields

abstract:
  The quasinormal modes of relativistic compact objects encode important
information about the gravitational response associated with astrophysical
phenomena. Detecting such oscillations would provide us with a unique
understanding of the properties of compact stars, and may give definitive
evidence for the existence of black holes. However, computing quasinormal modes
in realistic astrophysical environments is challenging due to the complexity of
the spacetime background and of the dynamics of the perturbations. We discuss
two complementary methods for computing the quasinormal modes of spherically
symmetric astrophysical systems, namely, the direct integration method and the
continued-fraction method. We extend these techniques to dealing with generic
coupled systems of linear equations, with the only assumption being the
interaction between different fields is effectively localized within a finite
region. In particular, we adapt the continued-fraction method to include cases
where a series solution can be obtained only outside an effective region. As an
application, we compute the polar quasinormal modes of boson stars by using the
continued-fraction method for the first time. The methods discussed here can be
applied to other situations in which the perturbations effectively couple only
within a finite region of space.


title:
Measure valued solutions to the spatially homogeneous Boltzmann equation
  without angular cutoff

abstract:
  A uniform approach is introduced to study the existence of measure valued
solutions to the homogeneous Boltzmann equation for both hard potential with
finite energy, and soft potential with finite or infinite energy, by using
Toscani metric. Under the non-angular cutoff assumption on the cross-section,
the solutions obtained are shown to be in the Schwartz space in the velocity
variable as long as the initial data is not a single Dirac mass without any
extra moment condition for hard potential, and with the boundedness on moments
of any order for soft potential.


title:
Well-posedness and long-time behavior for the Westervelt equation with
  absorbing boundary conditions of order zero

abstract:
  We investigate the Westervelt equation from nonlinear acoustics, subject to
nonlinear absorbing boundary conditions of order zero, which were recently
proposed by Kaltenbacher & Shevchenko. We apply the concept of maximal
regularity of type $L_p$ to prove global well-posedness for small initial data.
Moreover, we show that the solutions regularize instantaneously which means
that they are $C^\infty$ with respect to time $t$ as soon as $t>0$. Finally, we
show that each equilibrium is stable and each solution which starts
sufficiently close to an equilibrium converges at an exponential rate to a
possibly different equilibrium.


title: Exotic mapping class group actions on the circle

abstract:
  It has been known since the time of Nielsen that the mapping class group
$\text{Mod}_{g,1}$ of a surface of genus $g$ and one puncture acts faithfully
by homeomorphisms on the circle. In this note, we show that this standard
representation of the mapping class group is not rigid, precisely, if
$G<\text{Mod}_{g,1}$ is a finite index subgroup then there exist infinitely
many non--conjugate faithful representations $G\to \text{Homeo}^+(S^1)$. We
thus answer a question of B. Farb.


title:
Analysis of the SDFEM in a modified streamline diffusion norm for
  singularly perturbed convection diffusion problems

abstract:
  In this paper we consider a model singularly perturbed convection diffusion
problem which is solved by a streamline diffusion finite element method (SDFEM)
on a Shishkin rectangular mesh. To put insight into the influences of
stabilization parameters on SDFEM's solutions, we discuss how to obtain the
uniform estimates in the streamline diffusion norm which have not been analyzed
up to now. By decreasing the standard stabilization parameters properly near
the exponential layers, we obtain the uniform estimates in a norm, which is
stronger than the $\varepsilon-$energy norm and weaker than the standard
streamline diffusion norm. Numerical experiments show that the presented
stabilization parameters provide enough stability for the numerical schemes and
yield same accurate solutions as the standard ones.


title: Structural Properties of ${\cal R}_2$ Part I

abstract:
  This is the first of two papers establishing structural properties of ${\cal
R}_2$.


title: Spatio-spectral concentration of convolutions

abstract:
  Differential equations may possess coefficients that vary on a spectrum of
scales. Because coefficients are typically multiplicative in real space, they
turn into convolution operators in spectral space, mixing all wavenumbers.
However, in many applications, only the largest scales of the solution are of
interest and so the question turns to whether it is possible to build effective
coarse-scale models of the coefficients in such a manner that the large scales
of the solution are left intact. Here we apply the method of numerical
homogenization to deterministic linear equations to generate sub-grid-scale
models of coefficients at desired frequency cutoffs. We use the Fourier basis
to project, filter and compute correctors for the coefficients. The method is
tested in 1D and 2D scenarios and found to reproduce the coarse scales of the
solution to varying degrees of accuracy depending on the cutoff. We relate this
method to mode-elimination Renormalization Group (RG) and discuss the
connection between accuracy and the cutoff wavenumber. The tradeoff is governed
by a form of the uncertainty principle for convolutions, which states that as
the convolution operator is squeezed in the spectral domain, it broadens in
real space. As a consequence, basis sparsity is a high virtue and the choice of
the basis can be critical.


title:
Classical-field description of the quantum effects in the light-atom
  interaction

abstract:
  In this paper I show that light-atom interaction can be described using
purely classical field theory without any quantization. In particular, atom
excitation by light that accounts for damping due to spontaneous emission is
fully described in the framework of classical field theory. I show that three
well-known laws of the photoelectric effect can also be derived and that all of
its basic properties can be described within classical field theory.


title:
The Upper Bound of Radiation Energy in the Myers-Perry Black Hole
  Collision

abstract:
  We have investigated the upper bound of the radiation energy in the head-on
collision of two Myers-Perry black holes. Initially, the two black holes are
far away from each other, and they become one black hole after the collision.
We have obtained the upper bound of the radiation energy thermodynamically
allowed in the process. The upper bound of the radiation energy is obtained in
general dimensions. The radiation bound depends on the alignments of rotating
axes for a given initial condition due to spin-spin interaction. We have found
that the collision may not be occurred for a initially ultra-spinning black
hole.


title: Symmetric powers of Severi-Brauer varieties

abstract:
  We classify products of symmetric powers of a Severi-Brauer variety, up-to
stable birational equivalence. The description also includes Grassmannians and
moduli spaces of genus 0 stable maps.


title: A new bicommutant theorem

abstract:
  We prove an analogue of Voiculescu's theorem: Relative bicommutant of a
separable unital subalgebra $A$ of an ultraproduct of simple unital C*-algebras
is equal to $A$.


title:
Carrier Phase Estimation in Dispersion-Unmanaged Optical Transmission
  Systems

abstract:
  The study on carrier phase estimation (CPE) approaches, involving a one-tap
normalized least-mean-square (NLMS) algorithm, a block-wise average algorithm,
and a Viterbi-Viterbi algorithm has been carried out in the long-haul
high-capacity dispersion-unmanaged coherent optical systems. The close-form
expressions and analytical predictions for bit-error-rate behaviors in these
CPE methods have been analyzed by considering both the laser phase noise and
the equalization enhanced phase noise. It is found that the Viterbi-Viterbi
algorithm outperforms the one-tap NLMS and the block-wise average algorithms
for a small phase noise variance (or effective phase noise variance), while the
three CPE methods converge to a similar performance for a large phase noise
variance (or effective phase noise variance). In addition, the differences
between the three CPE approaches become smaller for higher-level modulation
formats.

categories: cs.IT math.IT physics.class-ph physics.optics


title: Structural Properties of ${\cal R}_2$ Part II

abstract:
  This is the second of two papers establishing structural properties of ${\cal
R}_2$.


title:
Numerical study of incommensurate and decoupled phases of spin-1/2
  chains with isotropic exchange J1, J2 between first and second neighbors

abstract:
  The spin-1/2 chain with isotropic exchange J1, J2 > 0 between first and
second neighbors is frustrated for either sign of J1 and has a singlet ground
state (GS) for J1/J2 $\ge - 4$. Its rich quantum phase diagram supports
gapless, gapped, commensurate (C), incommensurate (IC) and other phases.
Critical points J1/J2 are evaluated using exact diagonalization (ED) and
density matrix renormalization group (DMRG) calculations. The wave vector $q_G$
of spin correlations is related to GS degeneracy and obtained as the peak of
the spin structure factor $S(q)$. Variable $q_G$ indicates IC phases in two
$J1/J2$ intervals, [ -4, -1.24] and [0.44, 2], and a C-IC point at J1/J2 = 2.
The decoupled C phase in [-1.24, 0.44] has constant $q_G = {\pi}/2$,
nondegenerate GS, and a lowest triplet state with broken spin density on
sublattices of odd and even numbered sites. The lowest triplet and singlet
excitations, $E_m$ and $E_{\sigma}$, are degenerate in finite systems at
specific frustration $J1/J2$. Level crossing extrapolates in the thermodynamic
limit to the same critical points as $q_G$. The $S(q)$ peak diverges at $q_G =
{\pi}$ in the gapless phase with $J1/J2 > 4.148$ and quasi-long-range order
(QLRO({$\pi$})). $S(q)$ diverges at $\pm {\pi}/2$ in the decoupled phase with
QLRO({$\pi$}/2), but is finite in gapped phases with finite range correlations.
Numerical results and field theory agree at small $J2/J1$ but disagree for the
decoupled phase with weak exchange $J1$ between sublattices. Two related models
are summarized: one has an exact gapless decoupled phase with QLRO({$\pi$}/2)
and no IC phases; the other has a single IC phase without a decoupled phase in
between.


title:
Dynamics of skyrmions and edge states in the resistive regime of
  mesoscopic \emph{p}-wave superconductors

abstract:
  In a mesoscopic sample of a chiral $p\,$-wave superconductor, novel states
comprising skyrmions and edge states have been stabilized in out-of-plane
applied magnetic field. Using the time-dependent Ginzburg-Landau equations we
shed light on the dynamic response of such states to an external applied
current. Three different regimes are obtained, namely, the superconducting
(stationary), resistive (non-stationary) and normal regime, similarly to
conventional $s$-wave superconductors. However, in the resistive regime and
depending on the external current, we found that moving skyrmions and the edge
state behave distinctly different from the conventional kinematic vortex,
thereby providing new fingerprints for identification of $p\,$-wave
superconductivity.


title: Distinct surface and bulk charge density waves in ultrathin 1T-TaS2

abstract:
  We employ low-frequency Raman spectroscopy to study the nearly commensurate
(NC) to commensurate (C) charge density wave (CDW) transition in 1T-TaS2
ultrathin flakes protected from oxidation. We identify new modes originating
from C phase CDW phonons that are distinct from those seen in bulk 1T-TaS2. We
attribute these to CDW modes from the surface layers. By monitoring individual
modes with temperature, we find that surfaces undergo a separate,
low-hysteresis NC-C phase transition that is decoupled from the transition in
the bulk layers. This indicates the activation of a secondary phase nucleation
process in the limit of weak interlayer interaction, which can be understood
from energy considerations.


title: Q-factor enhancement in all-dielectric anisotropic nanoresonators

abstract:
  It is proposed and demonstrated that Q-factor of optical resonators can be
significantly enhanced by introducing an extra anisotropic cladding. We study
the optical resonances of all-dielectric core-shell nanoresonators and reveal
that radially anisotropic claddings can be employed to squeeze more energy into
the core area, leading to stronger light confinement and thus significant
Q-factor enhancement. We further show that the required homogenous claddings of
unusual anisotropy parameters can be realized through all-dielectric
multi-layered isotropic structures, which offers realistic extra flexibilities
of resonance manipulations for optical resonators.


title: Infinite sharply multiply transitive groups

abstract:
  The finite sharply $2$-transitive groups were classified by Zassenhaus in the
1930's. They essentially all look like the group of affine linear
transformations $x\mapsto ax+b$ for some field (or at least near-field) $K$.
However, the question remained open whether the same is true for infinite
sharply $2$-transitive groups. There has been extensive work on the structures
associated to such groups indicating that Zassenhaus' results might extend
might extend to the infinite setting. For many specific classes of groups, like
Lie groups, linear groups, or groups definable in o-minimal it was indeed
proved that all examples inside the given class arise in this way as affine
groups. However, it recently turned out that the reason for the lack of a
general proof was the fact that there are plenty of sharply $2$-transitive
groups which do not arise from fields or near-fields! In fact, it is not too
hard to construct concrete examples (see below). In this note, we survey
general sharply $n$-transitive groups and describe how to construct examples
not arising from fields.


title:
Observation of topological Faraday and Kerr rotations in quantum
  anomalous Hall state by terahertz magneto-optics

abstract:
  Electrodynamic responses from three-dimensional (3D) topological insulators
(TIs) are characterized by the universal magnetoelectric $E\cdot B$ term
constituent of the Lagrangian formalism. The quantized magnetoelectric
coupling, which is generally referred to as topological magnetoelectric (TME)
effect, has been predicted to induce exotic phenomena including the universal
low-energy magneto-optical effects. Here we report the experimental
demonstration of the long-sought TME effect, which is exemplified by
magneto-optical Faraday and Kerr rotations in the quantum anomalous Hall (QAH)
states of magnetic TI surfaces by terahertz magneto-optics. The universal
relation composed of the observed Faraday and Kerr rotation angles but not of
any material parameters (e.g. dielectric constant and magnetic susceptibility)
well exhibits the trajectory toward the fine structure constant $\alpha$ $(=
2\pi e^2/hc \sim 1/137)$ in the quantized limit. Our result will pave a way for
versatile TME effects with emergent topological functions.


abstract:
  In this note we investigate the generating series of the Euler
characteristics of Hilbert scheme of points on cyclic quotient singularities of
type (p,1). We link the appearing combinatorics to p-fountains, a
generalization of the notion of fountain of coins. We obtain a representation
of the generating series as coefficient of a two variable generating series.


title: Importance of effective dimensionality in manganese pnictides

abstract:
  In this paper we investigate the two manganese pnictides BaMn$_2$As$_2$ and
LaMnAsO, using fully charge self-consistent density functional plus dynamical
mean-field theory calculations. These systems have a nominally half-filled d
shell, and as a consequence, electronic correlations are strong, placing these
compounds at the verge of a metal-insulator transition. Although their crystal
structure is composed of similar building blocks, our analysis shows that the
two materials exhibit a very different effective dimensionality, LaMnAsO being
a quasi-two-dimensional material in contrast to the much more three-dimensional
BaMn$_2$As$_2$. We demonstrate that the experimentally observed differences in
the N\'eel temperature, the band gap, and the optical properties of the
manganese compounds under consideration can be traced back to exactly this
effective dimensionality. Our calculations show excellent agreement with
measured optical spectra.


title: Properly immersed surfaces in hyperbolic 3-manifolds

abstract:
  We study complete finite topology immersed surfaces $\Sigma$ in complete
Riemannian $3$-manifolds $N$ with sectional curvature $K_N\leq -a^2\leq 0$,
such that the absolute mean curvature function of $\Sigma$ is bounded from
above by $a$ and its injectivity radius function is not bounded away from zero
on each of its annular end representatives. We prove that such a surface
$\Sigma$ must be proper in $N$ and its total curvature must be equal to $2\pi
\chi(\Sigma)$. If $N$ is a hyperbolic $3$-manifold of finite volume and
$\Sigma$ is a properly immersed surface of finite topology with nonnegative
constant mean curvature less than 1, then we prove that each end of $\Sigma$ is
asymptotic (with finite positive multiplicity) to a totally umbilic annulus,
properly embedded in $N$.


title: One dimensional random walk killed on a finite set

abstract:
  We study the transition probability, say $p_A^n(x,y)$, of a one-dimensional
random walk on the integer lattice killed when entering into a non-empty finite
set $A$. The random walk is assumed to be irreducible and have zero mean and a
finite variance $\sigma^2$. We derive the asymptotic form of $p_A^n(x, y)$ for
large $n$ valid uniformly in the regime characterized by the conditions
$|x|\vee |y| =O(\sqrt n)$ and $|x|\wedge |y|= o(\sqrt n)$, in which $p^A_t({\bf
x},{\bf y})$ behaves for large $n$ like $[g_A^{+}(x)\hat g_{A}^{\,+}(y) +
g_A^-(x)\hat g_{A}^{\,-}(y)] (\sigma^{2}/2n) p^n(y-x)$. Here $p^n(y-x)$ is the
transition kernel of the random walk (without killing); $g^\pm_A$ are the Green
functions for the "exterior" of $A$ with "pole at $\pm \infty$" normalized so
that $g^\pm_A(x) \sim 2|x|/\sigma^2$ as $x \to \pm\infty$; and $\hat g_A^{\,
\pm}$ are the corresponding Green functions for the time-reversed walk.


title: Growth of balls of holomorphic sections on projective toric varieties

abstract:
  Let $\mathcal{O}(D)$ be an equivariant line bundle which is big and nef on a
complex projective nonsingular toric variety $X$. Given a continuous toric
metric $\|\cdot\|$ on $\mathcal{O}(D)$, we define the energy at equilibrium of
$(X,\phi_{\bar{D}})$ where $\phi_{\bar{D}}$ is the weight of the metrized toric
divisor $\bar{D}=(D,\|\cdot\|)$. We show that this energy describes the
asymptotic behaviour as $k\rightarrow \infty$ of the volume of the $L^2$-norm
unit ball induced by $(X,k\phi_{\bar{D}})$ on the space of global holomorphic
sections $H^0(X,\mathcal{O}(kD))$.


title: Asymptotic stability of $N$-solitons in the cubic NLS equation

abstract:
  In this article we consider the Cauchy problem for the cubic focusing
nonlinear Schr\"o\-dinger (NLS) equation on the line with initial datum close
to a particular $N$-soliton. Using inverse scattering and the $\bar{\partial}$
method we establish the decay of the $L^{\infty}$ norm of the residual term in
time.


title: A new relaxed HSS preconditioner for saddle point problems

abstract:
  We present a preconditioner for saddle point problems. The proposed
preconditioner is extracted from a stationary iterative method which is
convergent under a mild condition. Some properties of the preconditioner as
well as the eigenvalues distribution of the preconditioned matrix are
presented. The preconditioned system is solved by a Krylov subspace method like
restarted GMRES. Finally, some numerical experiments on test problems arisen
from finite element discretization of the Stokes problem are given to show the
effectiveness of the preconditioner.


title: Hardy spaces of vector-valued Dirichlet series

abstract:
  Given a Banach space $X$ and $1 \leq p \leq \infty$, it is well known that
the two Hardy spaces $H_p(\mathbb{T},X)$ ($\mathbb{T}$ the torus) and
$H_p(\mathbb{D},X)$ ($\mathbb{D}$ the disk) have to be distinguished carefully.
This motivates us to define and study two different types of Hardy spaces
$\mathcal{H}_p(X)$ and $\mathcal{H}^+_p(X)$ of Dirichlet series $\sum_n a_n
n^{-s}$ with coefficients in $X$. We characterize them in terms of summing
operators as well as holomorphic functions in infinitely many variables, and
prove that they coincide whenever $X$ has the analytic Radon-Nikod\'{y}m
Property. Consequences are, among others, a vector-valued version of the
Brother's Riesz Theorem in the infinite-dimensional torus, and an answer to the
question when $\mathcal{H}_1(X^{\ast})$ is a dual space.


title: Zeptonewton force sensing with nanospheres in an optical lattice

abstract:
  Optically trapped nanospheres in high-vaccum experience little friction and
hence are promising for ultra-sensitive force detection. Here we demonstrate
measurement times exceeding $10^5$ seconds and zeptonewton force sensitivity
with laser-cooled silica nanospheres trapped in an optical lattice. The
sensitivity achieved exceeds that of conventional room-temperature solid-state
force sensors, and enables a variety of applications including electric field
sensing, inertial sensing, and gravimetry. The optical potential allows the
particle to be confined in a number of possible trapping sites, with precise
localization at the anti-nodes of the optical standing wave. By studying the
motion of a particle which has been moved to an adjacent trapping site, the
known spacing of the lattice anti-nodes can be used to calibrate the
displacement spectrum of the particle. Finally, we study the dependence of the
trap stability and lifetime on the laser intensity and gas pressure, and
examine the heating rate of the particle in high vacuum in the absence of
optical feedback cooling.


title:
Conditions for Lorentz-invariant superluminal information transfer
  without signaling

abstract:
  We understand emergent quantum mechanics in the sense that quantum mechanics
describes processes of physical emergence relating an assumed sub-quantum
physics to macroscopic boundary conditions. The latter can be shown to entail
top-down causation, in addition to usual bottom-up scenarios. With this example
it is demonstrated that definitions of "realism" in the literature are simply
too restrictive. A prevailing manner to define realism in quantum mechanics is
in terms of pre-determination independent of the measurement. With our
counter-example, which actually is ubiquitous in emergent, or self-organizing,
systems, we argue for realism without pre-determination. We refer to earlier
results of our group showing how the guiding equation of the de Broglie-Bohm
interpretation can be derived from a theory with classical ingredients only.
Essentially, this corresponds to a "quantum mechanics without wave functions"
in ordinary 3-space, albeit with nonlocal correlations.
  This, then, leads to the central question of how to deal with the nonlocality
problem in a relativistic setting. We here show that a basic argument
discussing the allegedly paradox time ordering of events in EPR-type
two-particle experiments falls short of taking into account the contextuality
of the experimental setup. Consequently, we then discuss under which
circumstances (i.e. physical premises) superluminal information transfer (but
not signaling) may be compatible with a Lorentz-invariant theory. Finally, we
argue that the impossibility of superluminal signaling - despite the presence
of superluminal information transfer - is not the result of some sort of
conspiracy (a la "Nature likes to hide"), but the consequence of the
impossibility to exactly reproduce in repeated experimental runs a state's
preparation, or of the no-cloning theorem, respectively.


title:
High-harmonic generation in a quantum electron gas trapped in a
  nonparabolic and anisotropic well

abstract:
  An effective self-consistent model is derived and used to study the dynamics
of an electron gas confined in a nonparabolic and anisotropic quantum well.
This approach is based on the equations of quantum hydrodynamics, which
incorporate quantum and nonlinear effects in an approximate fashion. The
effective model consists of a set of six coupled differential equations
(dynamical system) for the electric dipole and the size of the electron gas.
Using this model we show that: (i) High harmonic generation is related to the
appearance of chaos in the phase space, as attested by related Poincar\'e
sections; (ii) Higher order harmonics can be excited efficiently and with
relatively weak driving fields by making use of chirped electromagnetic waves.


title:
Millimeter and Submillimeter Excess Emission in M33 revealed by Planck
  and LABOCA

abstract:
  Previous studies have shown the existence of an excess of emission at
submillimeter (submm) and millimeter (mm) wavelengths in the spectral energy
distribution (SED) of many low-metallicity galaxies. The goal of the present
study is to model separately the emission from the star forming (SF) component
and the emission from the diffuse interstellar medium (ISM) in the nearby
spiral galaxy M33. We decomposed the observed SED of M33 into its SF and
diffuse components. Mid-infrared (MIR) and far-infrared (FIR) fluxes were
extracted from Spitzer and Herschel data. At submm and mm wavelengths, we used
ground-based observations from APEX to measure the emission from the SF
component and data from the Planck space telescope to estimate the diffuse
emission. Both components were separately fitted using radiation transfer
models based on standard dust properties and a realistic geometry. Both modeled
SEDs were combined to build the global SED of M33. In addition, the radiation
field necessary to power the dust emission in our modeling was compared with
observations from GALEX, Sloan, and Spitzer. Our modeling is able to reproduce
the observations at MIR and FIR wavelengths, but we found a strong excess of
emission at submm and mm wavelengths, where the model expectations severely
underestimate the LABOCA and Planck fluxes. We also found that the ultraviolet
(UV) radiation escaping the galaxy is 70% higher than the model predictions. We
determined a gas-to-dust mass ratio Gdust~100, significantly lower than the
value expected from the sub-solar metallicity of M33. We discussed different
hypotheses to explain the discrepancies found in our study (i.e., excess of
emission at submm and mm wavelengths, deficit of UV attenuation, and abnormally
low value of Gdust), concluding that different dust properties in M33 is the
most plausible explanation.


title:
An Efficient Feedback Calibration Algorithm for Direct Imaging Radio
  Telescopes

abstract:
  We present the E-field Parallel Imaging Calibration (EPICal) algorithm, which
addresses the need for a fast calibration method for direct imaging radio
astronomy correlators. Direct imaging involves a spatial fast Fourier transform
of antenna signals, alleviating an $\mathcal{O}(N_{\mathrm{ant}}^2)$
computational bottleneck typical in radio correlators, and yielding a more
gentle $\mathcal{O}(N_g \log_2 N_g)$ scaling, where $N_{\mathrm{ant}}$ is the
number of antennas in the array and $N_g$ is the number of grid points in the
imaging analysis. This can save orders of magnitude in computation cost for
next generation arrays consisting of hundreds or thousands of antennas.
However, because antenna signals are mixed in the imaging correlator without
creating visibilities, gain correction must be applied prior to imaging, rather
than on visibilities post-correlation. We develop the EPICal algorithm to form
gain solutions quickly and without ever forming visibilities. This method
scales as the number of antennas, and produces results comparable to those from
visibilities. We use simulations to demonstrate the EPICal technique and study
the noise properties of our gain solutions, showing they are similar to
visibility based solutions in realistic situations. By applying EPICal to two
seconds of Long Wavelength Array data we achieve a 65% dynamic range
improvement compared to uncalibrated images, showing this algorithm is a
promising solution for next generation instruments.


title: Growth behaviour of periodic tame friezes

abstract:
  We examine the growth behaviour of the entries occurring in $n$-periodic tame
friezes of real numbers. Extending \cite{T}, we prove that generalised
recursive relations exist between all entries of such friezes. These recursions
are parametrised by a sequence of so-called growth coefficients, which are
shown to satisfy itself a recursive relation. Thus, all growth coefficients are
determined by a \emph{principle growth coefficients}, which can be read off
directly from the frieze.
  We place special emphasis on periodic tame friezes of positive integers,
specifying the values the growth coefficients take for any such frieze. We
establish that the growth coefficients of the pair of friezes arising from a
triangulation of an annulus coincide. The entries of both are shown to grow
asymptotically exponentially, while triangulations of a punctured disc are seen
to provide the only friezes of linear growth.


title: Optimal comparison of $P$-norms of Dirichlet Polynomials

abstract:
  Let $1 \leq p < q < \infty$. We show that \[ \sup{\frac{\left\|
D\right\|_{\mathcal{H}_{q}}}{\left\| D\right\|_{\mathcal{H}_{p}}}} =
\exp{\left( \frac{\log{x}}{\log{\log{x}}} \left(\log{\sqrt{\frac{q}{p}}} +
\left(\frac{\log{\log{\log{x}}}}{\log{\log{x}}}\right)\right) \right)} \,,\]
where the supremum is taken over all non-zero Dirichlet polynomials of the form
$D(s)=\sum_{n \leq x}{a_{n} n^{-s}}$. An aplication is given to the study of
multipliers between Hardy spaces of Dirichlet series.


title:
Strong deformation retraction of the space of Zoll Finsler projective
  planes

abstract:
  We show that the infinite-dimensional space of Zoll Finsler metrics on the
projective plane strongly deformation retracts to the canonical round metric.
In particular, this space of Zoll Finsler metrics is connected. Moreover, the
strong deformation retraction arises from a deformation of the geodesic flow of
every Zoll Finsler projective plane to the geodesic flow of the round metric
through a family of smooth free circle actions induced by the curvature flow of
the canonical round projective plane. This construction provides a description
of the geodesics of the Zoll Finsler metrics along the retraction.


title: From Design Contracts to Component Requirements Verification

abstract:
  During the development and verification of complex airborne systems, a
variety of languages and development environments are used for different levels
of the system hierarchy. As a result, there may be manual steps to translate
requirements between these different environments. This paper presents a
tool-supported export technique that translates high-level requirements from
the software architecture modeling environment into observers of requirements
that can be used for verification in the software component environment. This
allows efficient verification that the component designs comply with their
high-level requirements. It also provides an automated tool chain supporting
formal verification from system requirements down to low-level software
requirements that is consistent with certification guidance for avionics
systems. The effectiveness of the technique has been evaluated and demonstrated
on a medical infusion pump and an aircraft wheel braking system.


title:
Integrability Condition in the Statistical Model and the Addition
  Formula of g = 2 Hyperelliptic Function

abstract:
  The integrability condition of the Ising model is understood as the SU(2)
integrability condition and also as the model parameterized by the elliptic
function, where the integrability condition is understood as the addition
theorem of the elliptic function. The generalization of this integrability
condition is to find the solution of the higher rank Lie group integrability
condition and also to find the model parameterized by higher genus
hyperelliptic function. For the preparation of this purpose, we give the
explicit formula of the addition formula for g = 2 hyperelliptic function.


title: Plasmonic Films Can Easily Be Better: Rules and Recipes

abstract:
  High-quality materials are critical for advances in plasmonics, especially as
researchers now investigate quantum effects at the limit of single surface
plasmons or exploit ultraviolet- or CMOS-compatible metals such as aluminum or
copper. Unfortunately, due to inexperience with deposition methods, many
plasmonics researchers deposit metals under the wrong conditions, severely
limiting performance unnecessarily. This is then compounded as others follow
their published procedures. In this perspective, we describe simple rules
collected from the surface-science literature that allow high-quality plasmonic
films of aluminum, copper, gold, and silver to be easily deposited with
commonly available equipment (a thermal evaporator). Recipes are also provided
so that films with optimal optical properties can be routinely obtained.


title: Von Neumann Algebras form a Model for the Quantum Lambda Calculus

abstract:
  We present a model of Selinger and Valiron's quantum lambda calculus based on
von Neumann algebras, and show that the model is adequate with respect to the
operational semantics.


title:
High-pressure melt growth and transport properties of SiP, SiAs, GeP,
  and GeAs 2D layered semiconductors

abstract:
  Silicon and Germanium monopnictides SiP, SiAs, GeP and GeAs form a family of
2D layered semiconductors. We have succeeded in growing bulk single crystals of
these compounds by melt-growth under high pressure (0.5-1 GPa) in a cubic anvil
hot press. Large (mm-size), shiny, micaceous crystals of GeP, GeAs and SiAs
were obtained, and could be exfoliated into 2D flakes. Small and brittle
crystals of SiP were yielded by this method. High-pressure sintered
polycrystalline SiP and GeAs have also been successfully used as a precursor in
the Chemical Vapor Transport growth of these crystals in the presence of
I$_{2}$ as a transport agent. All compounds are found to crystallize in the
expected layered structure and do not undergo any structural transition at low
temperature, as shown by Raman spectroscopy down to T=5K. All materials exhibit
a semiconducting behavior. The electrical resistivity of GeP, GeAs and SiAs is
found to depend on temperature following a 2D-Variable Range Hopping conduction
mechanism. The availability of bulk crystals of these compounds opens new
perspectives in the field of 2D semiconducting materials for device
applications.


title:
Non-Equilibrium Thermodynamics and Stochasticity, A Phenomenological
  Look on Jarzynki's Equality

abstract:
  The theory of phenomenological Non-equilibrium Thermodynamics is extended by
includimg stochastic processes in order to account for recently derived
thermodynamical relations such as the Jarzynski equality. Four phenomenological
axioms are postulated resulting in a phenomenological interpretation of
Jarzynski's equality. Especially, considering the class of Jarzynski processes
Jarzynski's equality follows from the axiom that the statistical average of the
exponential work is protocol independent.


title: Embeddings of the "New Massive Gravity"

abstract:
  Using different types of embeddings of equations of motion we investigate the
existence of generalizations of the "New Massive Gravity" (NMG) model with the
same particle content (massive gravitons). By using the Weyl symmetry as a
guiding principle for the embeddings we show that the Noether gauge embedding
approach leads us to a sixth order model in derivatives with either a massive
or a massless ghost. If the Weyl symmetry is implemented by means of a
Stueckelberg field we obtain a new scalar-tensor model for massive gravitons.
It is ghost free and Weyl invariant at linearized level. The model can be
nonlinearly completed into a scalar field coupled to the NMG theory. The
elimination of the scalar field leads to a nonlocal modification of the NMG.
  We also prove to all orders in derivatives that there is no local, ghost free
embedding of the linearized NMG equations of motion around Minkowski space when
written in terms of one symmetric tensor. Regarding that point, NMG differs
from the Fierz-Pauli theory, since in later case we can replace the
Einstein-Hilbert action by specific $f(R,\Box\, R)$ generalizations and still
keep the theory ghost free at linearized level.


title: Spectrum analysis with quantum dynamical systems

abstract:
  Measuring the power spectral density of a stochastic process, such as a
stochastic force or magnetic field, is a fundamental task in many sensing
applications. Quantum noise is becoming a major limiting factor to such a task
in future technology, especially in optomechanics for temperature, stochastic
gravitational wave, and decoherence measurements. Motivated by this concern,
here we prove a measurement-independent quantum limit to the accuracy of
estimating the spectrum parameters of a classical stochastic process coupled to
a quantum dynamical system. We demonstrate our results by analyzing the data
from a continuous optical phase estimation experiment and showing that the
experimental performance with homodyne detection is close to the quantum limit.
We further propose a spectral photon counting method that can attain
quantum-optimal performance for weak modulation and a coherent-state input,
with an error scaling superior to that of homodyne detection at low
signal-to-noise ratios.


title:
Modeling and related results for current-actuated piezoelectric beams by
  including magnetic effects

abstract:
  Piezo-electric material can be controlled with current as the electrical
variable, instead of voltage. The main purpose of this paper is to derive the
governing equations for a current-controlled piezo-electric beam and to
investigate stabilizability. Besides the consideration of current control,
there are several new aspects to the model here. Most significantly, magnetic
effects are included. For the electromagnetic part of the model, electrical
potential and magnetic vector potential are chosen to be quadratic-through
thickness to include the induced effects of the electromagnetic field. Two sets
of decoupled system of partial differential equations are obtained; one for
stretching motion and another one for bending motion. Hamilton's principle is
used to derive a boundary value problem that models a single piezo-electric
beam actuated by a charge (or current) source at the electrodes. Current or
charge controllers at the electrodes can only control the stretching motion.
Attention is therefore focused on control of the stretching equations in this
paper. It is shown that the Lagrangian of the beam is invariant under certain
transformations. A Coulomb-type gauge condition which is widely used in the
electromagnetic theory is used here. This gauge condition decouples the
electrical potential equation from the equations of the magnetic potential. A
semigroup approach is used to prove that the Cauchy problem is well-posed.
Unlike the voltage or charge actuation, a bounded control operator in the
natural energy space is obtained in the current actuation case. The paper
concludes with analysis of stabilizability and comparison with other actuation
approaches and models.


title: Learning a Discriminative Null Space for Person Re-identification

abstract:
  Most existing person re-identification (re-id) methods focus on learning the
optimal distance metrics across camera views. Typically a person's appearance
is represented using features of thousands of dimensions, whilst only hundreds
of training samples are available due to the difficulties in collecting matched
training images. With the number of training samples much smaller than the
feature dimension, the existing methods thus face the classic small sample size
(SSS) problem and have to resort to dimensionality reduction techniques and/or
matrix regularisation, which lead to loss of discriminative power. In this
work, we propose to overcome the SSS problem in re-id distance metric learning
by matching people in a discriminative null space of the training data. In this
null space, images of the same person are collapsed into a single point thus
minimising the within-class scatter to the extreme and maximising the relative
between-class separation simultaneously. Importantly, it has a fixed dimension,
a closed-form solution and is very efficient to compute. Extensive experiments
carried out on five person re-identification benchmarks including VIPeR,
PRID2011, CUHK01, CUHK03 and Market1501 show that such a simple approach beats
the state-of-the-art alternatives, often by a big margin.


title:
Direct observation of local Rashba spin polarization and spin-layer
  locking in centrosymmetric monolayer PtSe$_2$

abstract:
  The generally accepted view that spin polarization is induced by the
asymmetry of the global crystal space group has limited the search for
spintronics [1] materials to non-centrosymmetric materials. Recently it has
been suggested that spin polarization originates fundamentally from local
atomic site asymmetries [2], and therefore centrosymmetric materials may
exhibit previously overlooked spin polarizations. Here by using spin- and
angle-resolved photoemission spectroscopy (spin-ARPES), we report helical spin
texture induced by local Rashba effect (R-2) in centrosymmetric monolayer
PtSe$_2$ film. First-principles calculations and effective analytical model
support the spin-layer locking picture: in contrast to the spin splitting in
conventional Rashba effect (R-1), the opposite spin polarizations induced by
R-2 are degenerate in energy while spatially separated in the top and bottom Se
layers. These results not only enrich our understanding of spin polarization
physics, but also may find applications in electrically tunable spintronics.


title:
The minimum mass of detectable planets in protoplanetary discs and the
  derivation of planetary masses from high resolution observations

abstract:
  We investigate the minimum planet mass that produces observable signatures in
infrared scattered light and submm continuum images and demonstrate how these
images can be used to measure planet masses to within a factor of about two. To
this end we perform multi-fluid gas and dust simulations of discs containing
low mass planets, generating simulated observations at $1.65 \mu$m, $10 \mu$m
and $850 \mu$m. We show that the minimum planet mass that produces a detectable
signature is $\sim 15 M_\oplus$: this value is strongly dependent on disc
temperature and changes slightly with wavelength (favouring the submm). We also
confirm previous results that there is a minimum planet mass of $\sim 20
M_\oplus$ that produces a pressure maximum in the disc: only planets above this
threshold mass generate a dust trap that can eventually create a hole in the
submm dust. Below this mass, planets produce annular enhancements in dust
outward of the planet and a reduction in the vicinity of the planet. These
features are in steady state and can be understood in terms of variations in
the dust radial velocity, imposed by the perturbed gas pressure radial profile,
analogous to a traffic jam. We also show how planet masses can be derived from
structure in scattered light and sub-mm images. We emphasise that simulations
with dust need to be run over thousands of planetary orbits so as to allow the
gas profile to achieve a steady state and caution against the estimation of
planet masses using gas only simulations.


title: Lid-driven cavity flow of viscoelastic liquids

abstract:
  The lid-driven cavity flow is a well-known benchmark problem for the
validation of new numerical methods and techniques. In experimental and
numerical studies with viscoelastic fluids in such lid-driven flows,
purely-elastic instabilities have been shown to appear even at very low
Reynolds numbers. A finite-volume viscoelastic code, using the log-conformation
formulation, is used in this work to probe the effect of viscoelasticity on the
appearance of such instabilities in two-dimensional lid-driven cavities for a
wide range of aspect ratios (0.125 < height/length < 4.0), at different Deborah
numbers under creeping-flow conditions and to understand the effects of
regularization of the lid velocity. The effect of the viscoelasticity on the
steady-state results and on the critical conditions for the onset of the
elastic instabilities are described and compared to experimental results.


title:
CGC/saturation approach for high energy soft interactions:
  $\mathbf{v_2}$ in proton-proton collisions

abstract:
  In this paper we continue our program to construct a model for high energy
soft interactions, based on the CGC/saturation approach. We demonstrate that in
our model which describes diffractive physics as well as multi-particle
production at high energy, the density variation mechanism leads to the value
of $v_2$ which is about $60\% \div 70\%$ of the measured $v_2$. Bearing in mind
that in CGC/saturation approach there are two other mechanisms present: Bose
enhancement in the wave function and local anisotropy, we believe that the
azimuthal long range rapidity correlations in proton-proton collisions stem
from the CGC/saturation physics, and not from quark-gluon plasma production.


title:
Coeval Observations of a Complete Sample of Blazars with Effelsberg,
  IRAM 30m, and Planck

abstract:
  We present the outline and first results of a project using the synergies of
the long term blazar radiomillimetre monitoring program F-GAMMA, the continued
scanning of the millimetre-submillimetre sky by the Planck satellite, together
with several dedicated observing programs at the Effelsberg 100m telescope, to
obtain a data sample unprecedented in both time resolution and frequency span.


title: Couplings between QCD axion and photon from string compactification

abstract:
  The QCD axion couplings of various invisible axion models are presented. In
particular, the exact global symmetry U(1)$_{\rm PQ}$ in the superpotential is
possible for the anomalous U(1) from string compactification, broken only by
the gauge anomalies at one loop level, and is shown to have the resultant
invisible axion coupling to photon, $c_{a\gamma\gamma}\ge
\frac83-c_{a\gamma\gamma}^{\rm ch\,br}$ where $c_{a\gamma\gamma}^{\rm
ch\,br}\simeq 2$. However, this bound is not applicable in approximate
U(1)$_{\rm PQ}$ models with sufficiently suppressed U(1)$_{\rm PQ}$-breaking
superpotential terms. We also present a simple method to obtain
$c_{a\gamma\gamma}^0$ which is the value obtained above the electroweak scale.


title: Six Functor Formalisms and Fibered Multiderivators

abstract:
  We develop the theory of (op)fibrations of 2-multicategories and use it to
define abstract six-functor-formalisms. We also give axioms for Wirthm\"uller
and Grothendieck formalisms (where either $f^!=f^*$ or $f_!=f_*$) or
intermediate formalisms where we have e.g. a natural morphism $f_! \rightarrow
f_*$. Finally, it is shown that a fibered multiderivator (in particular, a
closed monoidal derivator) can be interpreted as a six-functor-formalism on
diagrams (small categories). This gives, among other things, a considerable
simplification of the axioms and of the proofs of basic properties, and
clarifies the relation between the internal and external monoidal products in a
(closed) monoidal derivator. Our main motivation is the development of a theory
of derivator versions of six-functor-formalisms.


title:
Functional renormalization group analysis of the soft mode at the QCD
  critical point

abstract:
  We make an intensive investigation of the soft mode at the quantum
chromodynamics (QCD) critical point on the basis of the functional
renormalization group (FRG) method in the local potential approximation. We
calculate the spectral functions $\rho_{\sigma, \pi}(\omega,\, p)$ in the
scalar ($\sigma$) and pseudoscalar ($\pi$) channels beyond the random phase
approximation in the quark--meson model. At finite baryon chemical potential
$\mu$ with a finite quark mass, the baryon-number fluctuation is coupled to the
scalar channel and the spectral function in the $\sigma$ channel has a support
not only in the time-like ($\omega\,>\,p$) but also in the space-like
($\omega\,<\, p$) regions, which correspond to the mesonic and the
particle--hole phonon excitations, respectively. We find that the energy of the
peak position of the latter becomes vanishingly small with the height being
enhanced as the system approaches the QCD critical point, which is a
manifestation of the fact that the phonon mode is the {\em soft mode}
associated with the second-order transition at the QCD critical point, as has
been suggested by some authors. Moreover, our extensive calculation of the
spectral function in the $(\omega, p)$ plane enables us to see that the mesonic
and phonon modes have the respective definite dispersion relations
$\omega_{\sigma.{\rm ph}}(p)$, and it turns out that $\omega_{\sigma}(p)$
crosses the light-cone line into the space-like region, and then eventually
merges into the phonon mode as the system approaches the critical point more
closely. This implies that the sigma-mesonic mode also becomes soft at the
critical point. We also provide numerical stability conditions that are
necessary for obtaining the accurate effective potential from the flow
equation.


title: Complete Elgot Monads and Coalgebraic Resumptions

abstract:
  Monads are extensively used nowadays to abstractly model a wide range of
computational effects such as nondeterminism, statefulness, and exceptions. It
turns out that equipping a monad with a (uniform) iteration operator satisfying
a set of natural axioms allows for modelling iterative computations just as
abstractly. The emerging monads are called complete Elgot monads. It has been
shown recently that extending complete Elgot monads with free effects (e.g.
operations of sending/receiving messages over channels) canonically leads to
generalized coalgebraic resumption monads, previously used as semantic domains
for non-wellfounded guarded processes. In this paper, we continue the study of
the relationship between abstract complete Elgot monads and those that capture
coalgebraic resumptions, by comparing the corresponding categories of
(Eilenberg-Moore) algebras. To this end we first provide a characterization of
the latter category; even more generally, we formulate this characterization in
terms of Uustalu's parametrized monads. This is further used for establishing a
characterization of complete Elgot monads as precisely those monads whose
algebras are coherently equipped with the structure of algebras of coalgebraic
resumption monads.


title: Kinematically Detected Halo Streams

abstract:
  Clues to the origins and evolution of our Galaxy can be found in the
kinematics of stars around us. Remnants of accreted satellite galaxies produce
over- densities in velocity-space, which can remain coherent for much longer
than spatial over-densities. This chapter reviews a number of studies that have
hunted for these accretion relics, both in the nearby solar-neighborhood and
the more-distant stellar halo. Many observational surveys have driven this
field forwards, from early work with the Hipparcos mission, to contemporary
surveys like RAVE & SDSS. This active field continues to flourish, providing
many new discoveries, and will be revolutionised as the Gaia mission delivers
precise proper motions for a billion stars in our Galaxy.


title: Descent for coherent sheaves along formal/open coverings

abstract:
  For a regular noetherian scheme $X$ with a divisor with strict normal
crossings $D$ we prove that coherent sheaves satisfy descent w.r.t. the
'covering' consisting of the open parts in the various completions of $X$ along
the components of $D$ and their intersections.


title:
Measurements of $W^\pm Z$ production cross sections in $pp$ collisions
  at $\sqrt{s} = 8$ TeV with the ATLAS detector and limits on anomalous gauge
  boson self-couplings

abstract:
  This paper presents measurements of $W^\pm Z$ production in $pp$ collisions
at a center-of-mass energy of 8 TeV. The gauge bosons are reconstructed using
their leptonic decay modes into electrons and muons. The data were collected in
2012 by the ATLAS experiment at the Large Hadron Collider, and correspond to an
integrated luminosity of 20.3 fb$^{-1}$. The measured inclusive cross section
in the detector fiducial region is $\sigma_{W^\pm Z \rightarrow \ell^{'} \nu\
\ell \ell} = 35.1 \pm$ 0.9 (stat.) $\pm 0.8$ (sys.) $\pm 0.8$ (lumi.) fb, for
one leptonic decay channel. In comparison, the next-to-leading-order Standard
Model expectation is 30.0 $\pm$ 2.1 fb. Cross sections for $W^+Z$ and $W^-Z$
production and their ratio are presented as well as differential cross sections
for several kinematic observables. Limits on anomalous triple gauge boson
couplings are derived from the transverse mass spectrum of the $W^\pm Z$
system. From the analysis of events with a $W$ and a $Z$ boson associated with
two or more forward jets an upper limit at 95% confidence level on the $W^\pm
Z$ scattering cross section of 0.63 fb, for each leptonic decay channel, is
established, while the Standard Model prediction at next-to-leading order is
0.13 fb. Limits on anomalous quartic gauge boson couplings are also extracted.


title:
Right-angled Coxeter groups with n-dimensional Sierpi\'nski compacta as
  boundaries

abstract:
  For arbitrary integer n, we describe a large class of right-angled Coxeter
systems for which the visual baundary (of the corresponding Coxeter-Davis
complex) is homeomorphic to the n-dimensional Sierpi\'nski compactum. We also
provide a necessary and sufficient condition for a planar simplicial complex L
under which the right-angled Coxeter system whose nerve is L has the visual
boundary homeomorphic to the Sierpi\'nski curve.


title: Non-Abelian Parton Fractional Quantum Hall Effect in Multilayer Graphene

abstract:
  The current proposals for producing non-Abelian anyons and Majorana
particles, which are neither fermions nor bosons, are primarily based on the
realization of topological superconductivity in two dimensions. We show
theoretically that the unique Landau level structure of bilayer graphene
provides a new possible avenue for achieving such exotic particles.
Specifically, we demonstrate the feasibility of a "parton" fractional quantum
Hall (FQH) state, which supports non-Abelian particles without the usual
topological superconductivity. Furthermore, we advance this state as the
fundamental explanation of the puzzling $1/2$ FQH effect observed in bilayer
graphene [Kim {\em et al.}, Nano Lett. {\bf 15}, 7445 (2015)], and predict that
it will also occur in trilayer graphene. We indicate experimental signatures
that differentiate the parton state from other candidate non-Abelian FQH states
and predict that a transverse electric field can induce a topological quantum
phase transition between two distinct non-Abelian FQH states.


title:
Counting surface-kernel epimorphisms from a co-compact Fuchsian group to
  a cyclic group with motivations from string theory and QFT

abstract:
  Graphs embedded into surfaces have many important applications, in
particular, in combinatorics, geometry, and physics. For example, ribbon graphs
and their counting is of great interest in string theory and quantum field
theory (QFT). Recently, Koch, Ramgoolam, and Wen [Nuclear Phys.\,B {\bf 870}
(2013), 530--581] gave a refined formula for counting ribbon graphs and
discussed its applications to several physics problems. An important factor in
this formula is the number of surface-kernel epimorphisms from a co-compact
Fuchsian group to a cyclic group. The aim of this paper is to give an explicit
and practical formula for the number of such epimorphisms. As a consequence, we
obtain an `equivalent' form of the famous Harvey's theorem on the cyclic groups
of automorphisms of compact Riemann surfaces. Our main tool is an explicit
formula for the number of solutions of restricted linear congruence recently
proved by Bibak et al. using properties of Ramanujan sums and of the finite
Fourier transform of arithmetic functions.