title: Generation of chiral spin state by quantum simulation

abstract:
  Chirality of materials in nature appears when there are asymmetries in their
lattice structures or interactions in a certain environment. Recent development
of quantum simulation technology has enabled the manipulation of qubits.
Accordingly, chirality can be realized intentionally rather than passively
observed. Here we theoretically provide simple methods to create a chiral spin
state in a spin-1/2 qubit system on a square lattice. First, we show that
switching ON/OFF the Heisenberg and $XY$ interactions produces the chiral
interaction directly in the effective Hamiltonian without controlling local
fields. Moreover, when initial states of spin-qubits are appropriately
prepared, we prove that the chirality with desirable phase is dynamically
obtained. Finally, even for the case where switching ON/OFF the interactions is
infeasible and the interactions are always-on, we show that, by preparing an
asymmetric initial qubit state, the chirality whose phase is $\pi/2$ is
dynamically generated.


title: The Extreme Ultraviolet Spectra of Low Redshift Radio Loud Quasars

abstract:
  This paper reports on the extreme ultraviolet (EUV) spectrum of three low
redshift ($z \sim 0.6$) radio loud quasars, 3C 95, 3C 57 and PKS 0405-123. The
spectra were obtained with the Cosmic Origins Spectrograph (COS) of the Hubble
Space Telescope. The bolometric thermal emission, $L_{bol}$, associated with
the accretion flow is a large fraction of the Eddington limit for all of these
sources. We estimate the long term time averaged jet power, $\overline{Q}$, for
the three sources. $\overline{Q}/L_{bol}$, is shown to lie along the
correlation of $\overline{Q}/L_{bol}$ and $\alpha_{EUV}$ found in previous
studies of the EUV continuum of intermediate and high redshift quasars, where
the EUV continuum flux density between 1100 \AA\, and 700 \AA\, is defined by
$F_{\nu} \sim \nu^{-\alpha_{EUV}}$. The high Eddington ratios of the three
quasars extends the analysis into a wider parameter space. Selecting quasars
with high Eddington ratios has accentuated the statistical significance of the
partial correlation analysis of the data. Namely. the correlation of
$\overline{Q}/L_{\mathrm{bol}}$ and $\alpha_{EUV}$ is fundamental and the
correlation of $\overline{Q}$ and $\alpha_{EUV}$ is spurious at a very high
statistical significance level (99.8\%). This supports the regulating role of
ram pressure of the accretion flow in magnetically arrested accretion models of
jet production. In the process of this study, we use multi-frequency and
multi-resolution Very Large Array radio observations to determine that one of
the bipolar jets in 3C 57 is likely frustrated by galactic gas that keeps the
jet from propagating outside the host galaxy.


title:
Strategyproof Peer Selection using Randomization, Partitioning, and
  Apportionment

abstract:
  Peer reviews, evaluations, and selections are a fundamental aspect of modern
science. Funding bodies the world over employ experts to review and select the
best proposals from those submitted for funding. The problem of peer selection,
however, is much more general: a professional society may want to give a subset
of its members awards based on the opinions of all members; an instructor for a
Massive Open Online Course (MOOC) or an online course may want to crowdsource
grading; or a marketing company may select ideas from group brainstorming
sessions based on peer evaluation.
  We make three fundamental contributions to the study of peer selection, a
specific type of group decision-making problem, studied in computer science,
economics, and political science. First, we propose a novel mechanism that is
strategyproof, i.e., agents cannot benefit by reporting insincere valuations.
Second, we demonstrate the effectiveness of our mechanism by a comprehensive
simulation-based comparison with a suite of mechanisms found in the literature.
Finally, our mechanism employs a randomized rounding technique that is of
independent interest, as it solves the apportionment problem that arises in
various settings where discrete resources such as parliamentary representation
slots need to be divided proportionally.


title: Cooperation and Underlay Mode Selection in Cognitive Radio Network

abstract:
  In this research, we proposes a new method for cooperation and underlay mode
selection in cognitive radio networks. We characterize the maximum achievable
throughput of our proposed method of hybrid spectrum sharing. Hybrid spectrum
sharing is assumed where the Secondary User (SU) can access the Primary User
(PU) channel in two modes, underlay mode or cooperative mode with admission
control. In addition to access the channel in the overlay mode, secondary user
is allowed to occupy the channel currently occupied by the primary user but
with small transmission power. Adding the underlay access modes attains more
opportunities to the secondary user to transmit data. It is proposed that the
secondary user can only exploits the underlay access when the channel of the
primary user direct link is good or predicted to be in non-outage state.
Therefore, the secondary user could switch between underlay spectrum sharing
and cooperation with the primary user. Hybrid access is regulated through
monitoring the state of the primary link. By observing the simulation results,
the proposed model attains noticeable improvement in the system performance in
terms of maximum secondary user throughput than the conventional cooperation
and non-cooperation schemes.


title:
Theoretical study of photoproduction of $\eta ^{\prime} N$ bound state
  on deuteron target with forward proton emission

abstract:
  Possibilities of observing a signal of an $\eta ^{\prime} n$ bound state are
investigated by considering photoproductions of the $\eta$ and $\eta ^{\prime}$
mesons on a deuteron target with forward proton emission. For this purpose, we
take the $\eta ^{\prime} n$ interaction from the linear sigma model with a
coupling to $\eta n$, in which an $s$-wave $\eta ^{\prime} n$ bound state can
be dynamically generated, and we fix the $\gamma p \to \eta p$ and $\eta
^{\prime} p$ scattering amplitudes so as to reproduce the experimental cross
sections with forward proton emission. By using these $\gamma p \to \eta ^{(
\prime )} p$ and $\eta ^{( \prime )} n \to \eta ^{( \prime )} n$ amplitudes, we
calculate cross sections of the $\gamma d \to \eta n p$ and $\eta ^{\prime} n
p$ reactions with forward proton emission in single and $\eta ^{(\prime
)}$-exchange double scattering processes. As a result, we find that the signal
of the $\eta ^{\prime} n$ bound state can be seen below the $\eta ^{\prime} n$
threshold in the $\eta n$ invariant mass spectrum of the $\gamma d \to \eta n
p$ reaction and is comparable with the contribution from the quasifree $\eta
^{\prime}$ production above the $\eta ^{\prime} n$ threshold. We also discuss
the behavior of the signal of the $\eta ^{\prime} n$ bound state in several
experimental conditions and model parameters.


title: Online Multi-Target Tracking Using Recurrent Neural Networks

abstract:
  We present a novel approach to online multi-target tracking based on
recurrent neural networks (RNNs). Tracking multiple objects in real-world
scenes involves many challenges, including a) an a-priori unknown and
time-varying number of targets, b) a continuous state estimation of all present
targets, and c) a discrete combinatorial problem of data association. Most
previous methods involve complex models that require tedious tuning of
parameters. Here, we propose for the first time, an end-to-end learning
approach for online multi-target tracking. Existing deep learning methods are
not designed for the above challenges and cannot be trivially applied to the
task. Our solution addresses all of the above points in a principled way.
Experiments on both synthetic and real data show promising results obtained at
~300 Hz on a standard CPU, and pave the way towards future research in this
direction.


title:
Alternative approach to derive q-potential measures of refracted
  spectrally L\'evy processes

abstract:
  For a refracted L\'evy process driven by a spectrally negative L\'evy
process, we use a different approach to derive expressions for its q-potential
measures without killing. Unlike previous methods whose derivations depend on
scale functions which are defined only for spectrally negative L\'evy
processes, our approach is free of scale functions. This makes it possible to
extend the result here to a quite general refracted L\'evy process by applying
the approach presented below.


title: The Pierre Auger Observatory Upgrade - Preliminary Design Report

abstract:
  The Pierre Auger Observatory has begun a major Upgrade of its already
impressive capabilities, with an emphasis on improved mass composition
determination using the surface detectors of the Observatory. Known as
AugerPrime, the upgrade will include new 4 m$^2$ plastic scintillator detectors
on top of all 1660 water-Cherenkov detectors, updated and more flexible surface
detector electronics, a large array of buried muon detectors, and an extended
duty cycle for operations of the fluorescence detectors. This Preliminary
Design Report was produced by the Collaboration in April 2015 as an internal
document and information for funding agencies. It outlines the scientific and
technical case for AugerPrime. We now release it to the public via the arXiv
server. We invite you to review the large number of fundamental results already
achieved by the Observatory and our plans for the future.


title:
On the inference about the spectral distribution of high-dimensional
  covariance matrix based on high-frequency noisy observations

abstract:
  In practice, observations are often contaminated by noise, making the
resulting sample covariance matrix a signal-plus-noise sample covariance
matrix. Aiming to make inferences about the spectral distribution of the
population covariance matrix under such a situation, we establish an asymptotic
relationship that describes how the limiting spectral distribution of (signal)
sample covariance matrices depends on that of signal-plus-noise-type sample
covariance matrices. As an application, we consider inferences about the
spectral distribution of integrated covolatility (ICV) matrices of
high-dimensional diffusion processes based on high-frequency data with
microstructure noise. The (slightly modified) pre-averaging estimator is a
signal-plus-noise sample covariance matrix, and the aforementioned result,
together with a (generalized) connection between the spectral distribution of
signal sample covariance matrices and that of the population covariance matrix,
enables us to propose a two-step procedure to consistently estimate the
spectral distribution of ICV for a class of diffusion processes. An alternative
approach is further proposed, which possesses several desirable properties: it
is more robust, it eliminates the effects of microstructure noise, and the
asymptotic relationship that enables consistent estimation of the spectral
distribution of ICV is the standard Marcenko-Pastur equation. The performance
of the two approaches is examined via simulation studies under both synchronous
and asynchronous observation settings.


title: A Summary of Team MIT's Approach to the Amazon Picking Challenge 2015

abstract:
  The Amazon Picking Challenge (APC), held alongside the International
Conference on Robotics and Automation in May 2015 in Seattle, challenged
roboticists from academia and industry to demonstrate fully automated solutions
to the problem of picking objects from shelves in a warehouse fulfillment
scenario. Packing density, object variability, speed, and reliability are the
main complexities of the task. The picking challenge serves both as a
motivation and an instrument to focus research efforts on a specific
manipulation problem. In this document, we describe Team MIT's approach to the
competition, including design considerations, contributions, and performance,
and we compile the lessons learned. We also describe what we think are the main
remaining challenges.


title:
Bridging the Gaps Between Residual Learning, Recurrent Neural Networks
  and Visual Cortex

abstract:
  We discuss relations between Residual Networks (ResNet), Recurrent Neural
Networks (RNNs) and the primate visual cortex. We begin with the observation
that a special type of shallow RNN is exactly equivalent to a very deep ResNet
with weight sharing among the layers. A direct implementation of such a RNN,
although having orders of magnitude fewer parameters, leads to a performance
similar to the corresponding ResNet. We propose 1) a generalization of both RNN
and ResNet architectures and 2) the conjecture that a class of moderately deep
RNNs is a biologically-plausible model of the ventral stream in visual cortex.
We demonstrate the effectiveness of the architectures by testing them on the
CIFAR-10 and ImageNet dataset.


title: Just-in-Time Static Type Checking for Dynamic Languages

abstract:
  Dynamic languages such as Ruby, Python, and JavaScript have many compelling
benefits, but the lack of static types means subtle errors can remain latent in
code for a long time. While many researchers have developed various systems to
bring some of the benefits of static types to dynamic languages, prior
approaches have trouble dealing with metaprogramming, which generates code as
the program executes. In this paper, we propose Hummingbird, a new system that
uses a novel technique, just-in-time static type checking, to type check Ruby
code even in the presence of metaprogramming. In Hummingbird, method type
signatures are gathered dynamically at run-time, as those methods are created.
When a method is called, Hummingbird statically type checks the method body
against current type signatures. Thus, Hummingbird provides thorough static
checks on a per-method basis, while also allowing arbitrarily complex
metaprogramming. For performance, Hummingbird memoizes the static type checking
pass, invalidating cached checks only if necessary. We formalize Hummingbird
using a core, Ruby-like language and prove it sound. To evaluate Hummingbird,
we applied it to six apps, including three that use Ruby on Rails, a powerful
framework that relies heavily on metaprogramming. We found that all apps
typecheck successfully using Hummingbird, and that Hummingbird's performance
overhead is reasonable. We applied Hummingbird to earlier versions of one Rails
app and found several type errors that had been introduced and then fixed.
Lastly, we demonstrate using Hummingbird in Rails development mode to typecheck
an app as live updates are applied to it.


title: On the simplicity of induced modules for reductive Lie algebras. II

abstract:
  A sufficient condition for the simplicity of induced modules of reductive Lie
algebras is given.


title:
Envelope Hamiltonian for Charged-Particle Dynamics in General Linear
  Coupled Systems

abstract:
  We report the discovery of an envelope Hamiltonian describing the
charged-particle dynamics in general linear coupled lattices.


title:
Higher spin entanglement entropy at finite temperature with chemical
  potential

abstract:
  It is generally believed that the semiclassical AdS$_3$ higher spin gravity
could be described by a two dimensional conformal field theory with
${\cal{W}}$-algebra symmetry in the large central charge limit. In this paper,
we study the single interval entanglement entropy on the torus in the CFT with
a ${\cW}_3$ deformation. More generally we develop the monodromy analysis to
compute the two-point function of the light operators under a thermal density
matrix with a ${\cW}_3$ chemical potential to the leading order.
Holographically we compute the probe action of the Wilson line in the
background of the spin-3 black hole with a chemical potential. We find exact
agreement.


title: On the heteroclinic connection problem for multi-well gradient systems

abstract:
  We revisit the existence problem of heteroclinic connections in
$\mathbb{R}^N$ associated with Hamiltonian systems involving potentials
$W:\mathbb{R}^N\to \mathbb{R}$ having several global minima. Under very mild
assumptions on $W$ we present a simple variational approach to first find
geodesics minimizing length of curves joining any two of the potential wells,
where length is computed with respect to a degenerate metric having conformal
factor $\sqrt{W}.$ Then we show that when such a minimizing geodesic avoids
passing through other wells of the potential at intermediate times, it gives
rise to a heteroclinic connection between the two wells. This work improves
upon the approach of P.Sternberg in $\texttt{Vector-valued local minimizers of
nonconvex}$ $\texttt{variational problems}$, and represents a more geometric
alternative to the approaches for finding such connections described, for
example, by N.D. Alikakos and G.Fusco in $\texttt{On the connection problem for
potentials with}$ $\texttt{several global minima}$, by S.V. Bolotin in
$\texttt{Libration motions of natural dynamical systems}$, by J. Byeon, P.
Montecchiari, and P. Rabinowitz in $\texttt{A double well potential}$
$\texttt{system}$, and by P. Rabinowitz in $\texttt{Homoclinic and heteroclinic
orbits for a class of Hamiltonian}$ $\texttt{systems}$.


title: Multi-qubit entanglement in bi-directional chiral waveguide QED

abstract:
  We study the generation of entanglement induced by a single-photon Gaussian
wavepacket in multi-atom bi-directional waveguide QED. In particular, we
investigate the effect of increasing the number of atoms on the average
pairwise entanglement. We demonstrate by selecting smaller decay rates and in
chiral waveguide settings, that both entanglement survival times and maximum
generated entanglement can be increased by at least a factor of 3/2,
independent of the number of atoms. In addition, we analyze the influence of
detuning and delays on the robustness of the generated entanglement. There are
potential applications of our results in entanglement based multi-qubit quantum
networks


title:
Modeling Inter-Country Connection from Geotagged News Reports: A
  Time-Series Analysis

abstract:
  The development of theories and techniques for big data analytics offers
tremendous flexibility for investigating large-scale events and patterns that
emerge over space and time. In this research, we utilize a unique open-access
dataset "The Global Data on Events, Location and Tone" (GDELT) to model the
image of China in mass media, specifically, how China has related to the rest
of the world and how this connection has evolved upon time based on an
autoregressive integrated moving average (ARIMA) model. The results of this
research contribute both in methodological and empirical perspectives: We
examined the effectiveness of time series models in predicting trends in
long-term mass media data. In addition, we identified various types of
connection strength patterns between China and its top 15 related countries.
This study generates valuable input to interpret China's diplomatic and
regional relations based on mass media data, as well as providing
methodological references for investigating international relations in other
countries and regions in the big data era.


title: Robust regression for optimal individualized treatment rules

abstract:
  Because different patients may response quite differently to the same drug or
treatment, there is increasing interest in discovering individualized treatment
rule. In particular, people are eager to find the optimal individualized
treatment rules, which if followed by the whole patient population would lead
to the "best" outcome. In this paper, we propose new estimators based on robust
regression with general loss functions to estimate the optimal individualized
treatment rules. The new estimators possess the following nice properties:
first, they are robust against skewed, heterogeneous, heavy-tailed errors or
outliers; second, they are robust against misspecification of the baseline
function; third, under certain situations, the new estimator coupled with
pinball loss approximately maximizes the outcome's conditional quantile instead
of conditional mean, which leads to a different optimal individualized
treatment rule comparing with traditional Q- and A-learning. Consistency and
asymptotic normality of the proposed estimators are established. Their
empirical performance is demonstrated via extensive simulation studies and an
analysis of an AIDS data.


title:
Toward computer-assisted discovery and automated proofs of cutting plane
  theorems

abstract:
  Using a metaprogramming technique and semialgebraic computations, we provide
computer-based proofs for old and new cutting-plane theorems in
Gomory--Johnson's model of cut generating functions.


title:
Deep3D: Fully Automatic 2D-to-3D Video Conversion with Deep
  Convolutional Neural Networks

abstract:
  As 3D movie viewing becomes mainstream and Virtual Reality (VR) market
emerges, the demand for 3D contents is growing rapidly. Producing 3D videos,
however, remains challenging. In this paper we propose to use deep neural
networks for automatically converting 2D videos and images to stereoscopic 3D
format. In contrast to previous automatic 2D-to-3D conversion algorithms, which
have separate stages and need ground truth depth map as supervision, our
approach is trained end-to-end directly on stereo pairs extracted from 3D
movies. This novel training scheme makes it possible to exploit orders of
magnitude more data and significantly increases performance. Indeed, Deep3D
outperforms baselines in both quantitative and human subject evaluations.


title:
An efficient positive potential-density pair expansion for modelling
  galaxies

abstract:
  We present a novel positive potential-density pair expansion for modelling
galaxies, based on the Miyamoto-Nagai (MN) disc. By using three sets of such
discs, each one of them aligned along each symmetry axis, we are able to
reconstruct a broad range of potentials that correspond to density profiles
from exponential discs to 3D power law models with varying triaxiality
(henceforth simply "twisted" models). We increase the efficiency of our
expansion by allowing the scale length parameter of each disc to be negative.
We show that, for suitable priors on the scale length and height parameters,
these "MNn discs" have just one negative density minimum. This allows us to
ensure global positivity by demanding that the total density at the global
minimum is positive. We find that at better than 10\% accuracy in our density
reconstruction, we can represent a radial and vertical exponential disc over
$0.1-10$ scale lengths/heights with 4 MNn discs, an NFW profile over $0.1-10$
scale lengths with 4 MNn discs, and a twisted triaxial NFW profile with 3 MNn
discs per symmetry axis. Our expansion is efficient, fully analytic, and
well-suited to reproducing the density distribution and gravitational potential
of galaxies from discs to ellipsoids.


title: Two-photon entanglement in multi-qubit bi-directional waveguide QED

abstract:
  We study entanglement generation and control in bi-directional waveguide QED
driven by a two photon Gaussian wavepacket. In particular, we focus on how
increasing the number of qubits affects the overall average pairwise
entanglement in the system. We also investigate how the presence of a second
photon can introduce non-linearities, thereby manipulating the generated
entanglement. In addition, we show that through the introduction of chirality
and small decay rates, entanglement can be stored and enhanced up to factors of
2 and 3, respectively. Finally, we analyze the influence of finite detunnings
and time-delays on the generated entanglement.


title: Regularity of stationary solutions to the linearized Boltzmann equations

abstract:
  We consider the regularity of stationary solutions to the linearized
Boltzmann equations in bounded $C^1$ convex domains in $\mathbb{R}^3$ for gases
with cutoff hard potential and cutoff Maxwellian gases. We prove that the
stationary solutions solutions are H\"{o}lder continuous with order
$\frac1{2}^-$ away from the boundary provided the incoming data have the same
regularity. The key idea is to partially transfer the regularity in velocity
obtained by collision to space through transport and collision.


title:
Dynamic Planar Voronoi Diagrams for General Distance Functions and their
  Algorithmic Applications

abstract:
  We describe a new data structure for dynamic nearest neighbor queries in the
plane with respect to a general family of distance functions. These include
$L_p$-norms and additively weighted Euclidean distances. Our data structure
supports general (convex, pairwise disjoint) sites that have constant
description complexity (e.g., points, line segments, disks, etc.). Our
structure uses $O(n \log^3 n)$ storage, and requires polylogarithmic update and
query time, improving an earlier data structure of Agarwal, Efrat and Sharir
that required $O(n^\varepsilon)$ time for an update and $O(\log n)$ time for a
query [SICOMP, 1999]. Our data structure has numerous applications. In all of
them, it gives faster algorithms, typically reducing an $O(n^\varepsilon)$
factor in the previous bounds to polylogarithmic. In addition, we give here two
new applications: an efficient construction of a spanner in a disk intersection
graph, and a data structure for efficient connectivity queries in a dynamic
disk graph.


title:
A Discrete and Bounded Envy-Free Cake Cutting Protocol for Any Number of
  Agents

abstract:
  We consider the well-studied cake cutting problem in which the goal is to
find an envy-free allocation based on queries from $n$ agents. The problem has
received attention in computer science, mathematics, and economics. It has been
a major open problem whether there exists a discrete and bounded envy-free
protocol. We resolve the problem by proposing a discrete and bounded envy-free
protocol for any number of agents. The maximum number of queries required by
the protocol is $n^{n^{n^{n^{n^n}}}}$. We additionally show that even if we do
not run our protocol to completion, it can find in at most $n^3{(n^2)}^n$
queries a partial allocation of the cake that achieves proportionality (each
agent gets at least $1/n$ of the value of the whole cake) and envy-freeness.
Finally we show that an envy-free partial allocation can be computed in at most
$n^3{(n^2)}^n$ queries such that each agent gets a connected piece that gives
the agent at least $1/(3n)$ of the value of the whole cake.


title: Quasi-geostrophic dynamics in the presence of moisture gradients

abstract:
  The derivation of a quasi-geostrophic (QG) system from the rotating shallow
water equations on a midlatitude beta-plane coupled with moisture is presented.
Condensation is prescribed to occur whenever the moisture at a point exceeds a
prescribed saturation value. It is seen that a slow condensation time scale is
required to obtain a consistent set of equations at leading order. Further,
since the advecting wind fields are geostrophic, changes in moisture (and
hence, precipitation) occur only via non-divergent mechanisms. Following
observations, a saturation profile with gradients in the zonal and meridional
directions is prescribed. A purely meridional gradient has the effect of
slowing down the dry Rossby waves, through a reduction in the "equivalent
gradient" of the background potential vorticity. A large scale unstable moist
mode results on the inclusion of a zonal gradient by itself, or in conjunction
with a meridional moisture gradient. For gradients that are are representative
of the atmosphere, the most unstable moist mode propagates zonally in the
direction of increasing moisture, matures over an intraseasonal timescale and
has small phase speed.


title:
Angular width of Cherenkov radiation with inclusion of multiple
  scattering: an path-integral approach

abstract:
  Visible Cherenkov radiation can offers a method of the measurement of the
velocity of a charged particles. The angular width of the radiation is
important since it determines the resolution of the velocity measurement. In
this article, the angular width of Cherenkov radiation with inclusion of
multiple scattering is calculated through the path-integral method, and and the
analytical expressions are presented. The condition that multiple scattering
process dominates the angular distribution is obtained.


title:
Coherent electron-spin-resonance manipulation of three individual spins
  in a triple quantum dot

abstract:
  Quantum dot arrays provide a promising platform for quantum information
processing. For universal quantum simulation and computation, one central issue
is to demonstrate the exhaustive controllability of quantum states. Here, we
report the addressable manipulation of three single electron spins in a triple
quantum dot using a technique combining electron-spin-resonance and a
micro-magnet. The micro-magnet makes the local Zeeman field difference between
neighboring spins much larger than the nuclear field fluctuation, which ensures
the addressable driving of electron-spin-resonance by shifting the resonance
condition for each spin. We observe distinct coherent Rabi oscillations for
three spins in a semiconductor triple quantum dot with up to 25 MHz spin
rotation frequencies. This individual manipulation over three spins enables us
to arbitrarily change the magnetic spin quantum number of the three spin
system, and thus to operate a triple-dot device as a three-qubit system in
combination with the existing technique of exchange operations among three
spins.


title:
In-plane electric fields and the $\nu=\frac{5}{2}$ fractional quantum
  Hall effect in a disk geometry

abstract:
  The $\nu=\frac{5}{2}$ fractional quantum Hall effect is of experimental and
theoretical interest due to the possible non-Abelian statistics of the
excitations in the electron liquid. A small voltage difference across a sample
applied in experiments to probe the system is often ignored in theoretical
studies due to the Galilean invariance in the thermodynamic limit. No
experimental sample, however, is Galilean invariant. In this work, we explore
the effects of the probe electric fields in a disk geometry with finite
thickness. We find that weak probe fields enhance the Moore-Read Pfaffian state
but sufficiently strong electric fields destroy the incompressible state. In a
disk geometry, the behavior of the system depends on the polarity of the
applied radial field, which can potentially be observed in experiments using in
a Corbino disk configuration. Our simulation also shows that the application of
such a field enhances the coherence length of quasiholes propagating through
the edge channels


title:
Distributed Cooperative Detection for Multi-Receiver Molecular
  Communication

abstract:
  In this paper, a cooperative diffusion-based molecular communication system
is considered where distributed receivers collaboratively determine a
transmitter's signal. In this system, the receivers first make local hard
decisions about the current transmitted bit and then report these decisions to
a fusion center (FC). The FC combines the local hard decisions to make a global
decision using an N-out-of-K fusion rule. Asymmetric and symmetric topologies
are considered and for each topology, two reporting scenarios, namely, perfect
reporting and noisy reporting, are addressed. Closed-form analytical
expressions for the expected global error probability are derived for all
considered topologies and scenarios. Numerical and simulation results show that
system reliability can be greatly improved by combining the detection
information of distributed receivers.


title:
Sublinear Time Estimation of Degree Distribution Moments: The Degeneracy
  Connection

abstract:
  We revisit the classic problem of estimating the degree distribution moments
of an undirected graph. Consider an undirected graph $G=(V,E)$ with $n$
vertices, and define (for $s > 0$) $\mu_s = \frac{1}{n}\cdot\sum_{v \in V}
d^s_v$. Our aim is to estimate $\mu_s$ within a multiplicative error of
$(1+\epsilon)$ (for a given approximation parameter $\epsilon>0$) in sublinear
time. We consider the sparse graph model that allows access to: uniform random
vertices, queries for the degree of any vertex, and queries for a neighbor of
any vertex. For the case of $s=1$ (the average degree),
$\widetilde{O}(\sqrt{n})$ queries suffice for any constant $\epsilon$ (Feige,
SICOMP 06 and Goldreich-Ron, RSA 08). Gonen-Ron-Shavitt (SIDMA 11) extended
this result to all integral $s > 0$, by designing an algorithms that performs
$\widetilde{O}(n^{1-1/(s+1)})$ queries.
  We design a new, significantly simpler algorithm for this problem. In the
worst-case, it exactly matches the bounds of Gonen-Ron-Shavitt, and has a much
simpler proof. More importantly, the running time of this algorithm is
connected to the degeneracy of $G$. This is (essentially) the maximum density
of an induced subgraph. For the family of graphs with degeneracy at most
$\alpha$, it has a query complexity of
$\widetilde{O}\left(\frac{n^{1-1/s}}{\mu^{1/s}_s} \Big(\alpha^{1/s} +
\min\{\alpha,\mu^{1/s}_s\}\Big)\right) =
\widetilde{O}(n^{1-1/s}\alpha/\mu^{1/s}_s)$. Thus, for the class of bounded
degeneracy graphs (which includes all minor closed families and preferential
attachment graphs), we can estimate the average degree in $\widetilde{O}(1)$
queries, and can estimate the variance of the degree distribution in
$\widetilde{O}(\sqrt{n})$ queries. This is a major improvement over the
previous worst-case bounds. Our key insight is in designing an estimator for
$\mu_s$ that has low variance when $G$ does not have large dense subgraphs.


title: Tests of gravitational symmetries with radio pulsars

abstract:
  Symmetries play important roles in modern theories of physical laws. In this
paper, we review several experimental tests of important symmetries associated
with the gravitational interaction, including the universality of free fall for
self-gravitating bodies, time-shift symmetry in the gravitational constant,
local position invariance and local Lorentz invariance of gravity, and
spacetime translational symmetries. Recent experimental explorations for
post-Newtonian gravity are discussed, of which, those from pulsar astronomy are
highlighted. All of these tests, of very different aspects of gravity theories,
at very different length scales, favor to very high precision the predictions
of the strong equivalence principle (SEP) and, in particular, general
relativity which embodies SEP completely. As the founding principles of
gravity, these symmetries are motivated to be promoted to even stricter tests
in future.


title:
Quantum coherence between cavity and artificial atom in a
  superconducting circuit QED ladder system

abstract:
  We have created a quantum three-level ladder system with the cavity
dispersive energy level in a superconducting circuit quantum electrodynamics
system consisting of a transmon qubit and a cavity, and have directly observed
the Autler-Townes splitting effect instead of representing it by the
probability of the qubit being at each level. A coupler tone is applied on the
transition between the second excited state of transmon and cavity dispersive
level, while the cavity spectrum is probed. A doublet transmission and
anormalous dispersion spectrum of the cavity level is clearly shown. The
inverse Fourier transform of cavity spectrum indicates that there is a quantum
coherence Rabi oscillation of the populations between cavity and qubit.


title: On the photoelectric quantum yield of small dust particles

abstract:
  Photoelectron emission is crucial to electric charging of dust particles
around main-sequence stars and gas heating in various dusty environments. An
estimate of the photoelectric processes contains an ill-defined parameter
called the photoelectric quantum yield, which is the total number of electrons
ejected from a dust particle per absorbed photon. Here we revisit the so-called
small particle effect of photoelectron emission and provide an analytical model
to estimate photoelectric quantum yields of small dust particles in sizes down
to nanometers. We show that the small particle effect elevates the
photoelectric quantum yields of nanoparticles up to by a factor of $10^3$ for
carbon, water ice, and organics, and a factor of $10^2$ for silicate, silicon
carbide, and iron. We conclude the surface curvature of the particles is a
quantity of great importance to the small particle effect, unless the particles
are submicrometers in radius or larger.


title: Quantum phase transitions with dynamical flavors

abstract:
  We study the properties of a D6-brane probe in the ABJM background with
smeared massless dynamical quarks in the Veneziano limit. Working at zero
temperature and non-vanishing charge density, we show that the system undergoes
a quantum phase transition in which the topology of the brane embedding changes
from a black hole to a Minkowski embedding. In the unflavored background the
phase transition is of second order and takes place when the charge density
vanishes. We determine the corresponding critical exponents and show that the
scaling behavior near the quantum critical point has multiplicative logarithmic
corrections. In the background with dynamical quarks the phase transition is of
first order and occurs at non-zero charge density. In this case we compute the
discontinuity of several physical quantities as functions of the number $N_f$
of unquenched quarks of the background.


title: On Transience of L\'evy-Type Processes

abstract:
  In this paper, we study weak and strong transience of a class of Feller
processes associated with pseudo-differential operators, the so-called
L\'evy-type processes. As a main result, we derive Chung-Fuchs type conditions
(in terms of the symbol of the corresponding pseudo-differential operator) for
these properties, which are sharp for L\'evy processes. Also, as a consequence,
we discuss the weak and strong transience with respect to the dimension of the
state space and Pruitt indices, thus generalizing some well-known results
related to elliptic diffusion and stable L\'evy processes. Finally, in the case
when the symbol is radial (in the co-variable) we provide conditions for the
weak and strong transience in terms of the L\'evy measures.


title:
Hubble imaging of V1331 Cygni: Proper motion study of its circumstellar
  structures

abstract:
  The young star V1331 Cyg received previous attention because it is surrounded
by an optical, arc-like reflection nebula. V1331 Cyg is commonly considered to
be a candidate for an object that has undergone an FU-Ori (FUOR) the outbreak
in the past. This in turn could lead to a time-varying appearance of the dusty
arcs that may be revealed by multi-epoch imaging. In particular, a radial
colour analysis of the dust arcs can then be attempted to check whether radial
grain size distribution was modified by a previous FUOR wind. Second-epoch
imaging of V1331 Cyg was obtained by us in 2009 using the Hubble Space
Telescope (HST). By comparing this to archival HST data from 2000, we studied
the time evolution of the circumstellar nebulae. After a point spread function
subtraction using model point spread functions, we used customised routines to
perform a proper motion analysis. The nebula expansion was first derived by
deconvolving and correlating the two-epoch radial brightness profiles.
Additional data from other facilities TLS, UKIDSS, SPITZER, and HERSCHEL were
also incorporated to improve our understanding of the star in terms of
environment, viewing angle, bipolar outflow length, and the FUOR phenomenon.
The derived radial colour profiles do not indicate a spatial separation of the
dust grain sizes. The HERSCHEL 160 micron images show for the time thermal
emission from dust probably residing in the outer arc. By viewing V1331 Cyg
almost pole-on, the length of the bipolar outflow exceeds previous estimates by
far. The outer arc expansion timescale is consistent with the implantation time
of the CO torus, which supports the hypothesis of an outburst that occurred a
few thousand years ago. The azimuthal colour variation of the outer arc is
probably due to changes of the scattering angle, imposed by a tilt or helical
geometry of the dust configuration.


title:
Long Term Performance Studies of Large Oil-Free Bakelite Resistive Plate
  Chamber

abstract:
  Several high energy physics and neutrino physics experiments worldwide
require large-size RPCs to cover wide acceptances. The muon tracking systems in
the Iron calorimeter (ICAL) in the INO experiment, India and the near detector
in DUNE at Fermilab are two such examples. A (240 cm $\times$ 120 cm $\times$
0.2 cm) bakelite RPC has been built and tested at Variable Energy Cyclotron
Centre, Kolkata, using indigenous materials procured from the local market. No
additional lubricant, like oil has been used on the electrode surfaces for
smoothening. The chamber is in operation for $>$ 365 days. We have tested the
chamber for its long term operation. The leakage current, bulk resistivity,
efficiency, noise rate and time resolution of the chamber have been found to be
quite stable during the testing peroid. It showed an efficiency $>$ 95$\%$ with
an average time resolution of $\sim$0.83 ns at the point of measurement at 9000
V throughout the testing period. Details of the long term performance of the
chamber have been discussed.


title: A Rotation/Magnetism Analogy for the Quark-Gluon Plasma

abstract:
  In peripheral heavy ion collisions, the Quark-Gluon Plasma that may be formed
often has a large angular momentum per unit energy. This angular momentum may
take the form of (local) rotation. In many physical systems, rotation can have
effects analogous to those produced by a magnetic field; thus, there is a risk
that the effects of local rotation in the QGP might be mistaken for those of
the large genuine magnetic fields which are also known to arise in these
systems. Here we use the gauge-gravity duality to investigate this, and we find
indeed that, with realistic parameter values, local rotation has effects on the
QGP (at high values of the baryonic chemical potential) which are not only of
the same kind as those produced by magnetic fields, but which can in fact be
substantially larger. Furthermore, the combined effect of rotation and
magnetism is to change the shape of the main quark matter phase transition line
in an interesting way, reducing the magnitude of its curvature; again, local
rotation contributes to this phenomenon at least as strongly as magnetism.


title:
Interactive Perception: Leveraging Action in Perception and Perception
  in Action

abstract:
  Recent approaches in robotics follow the insight that perception is
facilitated by interaction with the environment. These approaches are subsumed
under the term of Interactive Perception (IP). It provides the following
benefits: (i) interaction with the environment creates a rich sensory signal
that would otherwise not be present and (ii) knowledge of the regularity in the
combined space of sensory data and action parameters facilitate the prediction
and interpretation of the signal. In this survey we postulate this as a
principle and collect evidence in support by analyzing and categorizing
existing work in this area. We also provide an overview of the most important
applications of Interactive Perception. We close this survey by discussing
remaining open questions. Thereby, we hope to define a field and inspire future
work.


title: On generalized non-commuting graph of a finite ring

abstract:
  Let $S, K$ be two subrings of a finite ring $R$. Then the generalized
non-commuting graph of subrings $S, K$ of $R$, denoted by $\Gamma_{S, K}$, is a
simple graph whose vertex set is $(S \cup K) \setminus (C_K(S) \cup C_S(K))$
and two distinct vertices $a, b$ are adjacent if and only if $a \in S$ or $b
\in S$ and $ab \neq ba$. We determine the diameter, girth and some dominating
sets for $\Gamma_{S, K}$. Some connections between the $\Gamma_{S, K}$ and
$\Pr(S, K)$ are also obtained. Further, $\Z$-isoclinism between two pairs of
finite rings is defined and showed that the generalized non-commuting graphs of
two $\Z$-isoclinic pairs are isomorphic under some condition.


title:
Observability Inequality of Backward Stochastic Heat Equations for
  Measurable Sets and Its Applications

abstract:
  This paper aims to provide directly the observability inequality of backward
stochastic heat equations for measurable sets. As an immediate application, the
null controllability of the forward heat equations is obtained. Moreover, an
interesting relaxed optimal actuator location problem is formulated, and the
existence of its solution is proved. Finally, the solution is characterized by
a Nash equilibrium of the associated game problem.


title: Accelerated Observers, Thermal Entropy, and Spacetime Curvature

abstract:
  Assuming that an accelerated observer with four-velocity ${\bf u}_{\rm R}$ in
a curved spacetime attributes the standard Bekenstein-Hawking entropy and Unruh
temperature to his "local Rindler horizon", we show that the $\rm \it change$
in horizon area under parametric displacements of the horizon has a very
specific thermodynamic structure. Specifically, it entails information about
the time-time component of the Einstein tensor: $\bf G({\bf u}_{\rm R}, {\bf
u}_{\rm R})$. Demanding that the result holds for all accelerated observers,
this actually becomes a statement about the full Einstein tensor, $\rm \bf G$.
  We also present some perspectives on the free fall with four-velocity ${\bf
u}_{\rm ff}$ across the horizon that leads to such a loss of entropy for an
accelerated observer. Motivated by results for some simple quantum systems at
finite temperature $T$, we conjecture that at high temperatures, there exists a
universal, system-independent curvature correction to partition function and
thermal entropy of $\rm \it any$ freely falling system, characterised by the
dimensional quantity $\Delta = {\bf R({\bf u}_{\rm ff}, {\bf u}_{\rm ff})}
\left(\hbar c/kT \right)^2$.


title:
Effect of total and pair configurational entropy in determining dynamics
  of supercooled liquids over a range of densities

abstract:
  In this paper, we present a study of supercooled liquids interacting with the
Lennard Jones (LJ) potential and the corresponding purely repulsive
(Weeks-Chandler-Andersen or WCA) potential, over a range of densities and
temperatures, in order to understand the origin of their different dynamics in
spite of their structures being similar. Using the configurational entropy as
the thermodynamic marker via the Adam Gibbs (AG) relation, we show that the
difference in the dynamics of these two systems at low temperatures can be
explained from thermodynamics. At higher densities both the thermodynamical and
dynamical difference between these model systems decrease, which is
quantitatively demonstrated in this paper by calculating different parameters.
The study also reveals the origin of the difference in pair entropy despite the
similarity in the structure. Although the maximum difference in structure is
obtained in the partial radial distribution function (rdf) of the B type of
particles, the rdf of AA pairs and AB pairs give rise to the differences in the
entropy and dynamics. This work supports the observation made in an earlier
study (Phys. Rev. Lett.,\textbf {113}, 225701, 2014) and shows that they are
generic in nature, independent of density.


title:
Three-dimensional single gyroid photonic crystals with a mid-infrared
  bandgap

abstract:
  A gyroid structure is a distinct morphology that is triply periodic and
consists of minimal isosurfaces containing no straight lines. We have designed
and synthesized amorphous silicon (a-Si) mid-infrared gyroid photonic crystals
that exhibit a complete bandgap in infrared spectroscopy measurements. Photonic
crystals were synthesized by deposition of a-Si/Al2O3 coatings onto a
sacrificial polymer scaffold defined by two-photon lithography. We observed a
100% reflectance at 7.5 \mum for single gyroids with a unit cell size of 4.5
\mum, in agreement with the photonic bandgap position predicted from full-wave
electromagnetic simulations, whereas the observed reflection peak shifted to 8
um for a 5.5 \mum unit cell size. This approach represents a
simulation-fabrication-characterization platform to realize three-dimensional
gyroid photonic crystals with well-defined dimensions in real space and
tailored properties in momentum space.


title:
Deterministic evolution of an asexual population under the action of
  beneficial and deleterious mutations on additive fitness landscapes

abstract:
  We study a continuous time model for the frequency distribution of an
infinitely large asexual population in which both beneficial and deleterious
mutations occur and the fitness is additive. When beneficial mutations are
ignored, the exact solution for the frequency distribution is known to be a
Poisson distribution. Here we include beneficial mutations and obtain exact
expressions for the frequency distribution at all times using an eigenfunction
expansion method. We find that the stationary distribution is non-Poissonian
and related to the Bessel function of the first kind. We also provide suitable
approximations for the stationary distribution and the time to relax to the
steady state. Our exact results, especially at mutation-selection equilibrium,
can be useful in developing semi-deterministic approaches to understand
stochastic evolution.


title: Robustness of Power-law Behavior in Cascading Failure Models

abstract:
  Inspired by reliability issues in electric transmission networks, we use a
probabilistic approach to study the occurrence of large failures in a stylized
cascading failure model. In this model, lines have random capacities that
initially meet the load demands imposed on the network. Every single line
failure changes the load distribution in the surviving network, possibly
causing further lines to become overloaded and trip as well. An initial single
line failure can therefore potentially trigger massive cascading effects, and
in this paper we measure the risk of such cascading events by the probability
that the number of failed lines exceeds a certain large threshold. Under
particular critical conditions, the exceedance probability follows a power-law
distribution, implying a significant risk of severe failures. We examine the
robustness of the power-law behavior by exploring under which assumptions this
behavior prevails.


title:
Electrical properties and porosity of the first meter of the nucleus of
  67P/Churyumov-Gerasimenko. As constrained by the Permittivity Probe
  SESAME-PP/Philae/Rosetta

abstract:
  Context. Comets are primitive objects, remnants of the volatile-rich
planetesimals from which the solar system condensed. Knowing their structure
and composition is thus crucial for the understanding of our origins. After the
successful landing of Philae on the nucleus of 67P/Churyumov-Gerasimenko in
November 2014, for the first time, the Rosetta mission provided the opportunity
to measure the low frequency electrical properties of a cometary mantle with
the permittivity probe SESAME-PP (Surface Electric Sounding and Acoustic
Monitoring Experiment - Permittivity Probe).
  Aims. In this paper, we conduct an in-depth analysis of the data from active
measurements collected by SESAME-PP at Abydos, which is the final landing site
of Philae, to constrain the porosity and, to a lesser extent, the composition
of the surface material down to a depth of about 1 meter.
  Methods. SESAME-PP observations on the surface are then analyzed by
comparison with data acquired during the descent toward the nucleus and with
numerical simulations that explore different possible attitudes and
environments of Philae at Abydos using a method called the Capacity-Influence
Matrix Method.
  Results. Reasonably assuming that the two receiving electrode channels have
not drifted with respect to each other during the ten-year journey of the
Rosetta probe to the comet, we constrain the dielectric constant of the first
meter below the surface at Abydos to be > 2.45 p/m 0.20, which is consistent
with a porosity < 50% if the dust phase is analogous to carbonaceous chondrites
and < 75% in the case of less primitive ordinary chondrites. This indicates
that the near surface of the nucleus of 67P/Churyumov-Gerasimenko nucleus is
more compacted than its interior and suggests that it could consist of a
sintered dust-ice layer.


title:
Coincidence spectroscopy of high-lying Rydberg states produced in strong
  laser fields

abstract:
  We report on the measurement of electron emission after the interaction of
strong laser pulses with atoms and molecules. These electrons originate from
high-lying Rydberg states with quantum numbers up to $n \lesssim 120$ formed by
frustrated field ionization. Simulations show that both tunneling ionization by
a weak dc field and photoionization by the black-body radiation contribute to
delayed electron emission on the nano- to microsecond scale. We measured
ionization rates from these Rydberg states by coincidence spectroscopy.
Further, the dependence of the Rydberg-state production on the ellipticity of
the driving laser field proves that such high-lying Rydberg states are
populated through electron recapture. The present experiment provides detailed
quantitative information on Rydberg production by frustrated field ionization.


title:
Measurement-based generation of shaped single photons and coherent state
  superpositions in optical cavities

abstract:
  We propose related schemes to generate arbitrarily shaped single photons,
i.e. photons with an arbitrary temporal profile, and coherent state
superpositions using simple optical elements. The first system consists of two
coupled cavities, a memory cavity and a shutter cavity, containing a second
order optical nonlinearity and electro-optic modulator (EOM) respectively.
Photodetection events of the shutter cavity output herald preparation of a
single photon in the memory cavity, which may be stored by immediately changing
the optical length of the shutter cavity with the EOM after detection.
On-demand readout of the photon, with arbitrary shaping, can be achieved
through modulation of the EOM. The second scheme consists of a memory cavity
with two outputs which are interfered, phase shifted, and measured. States that
closely approximate a coherent state superposition can be produced through
postselection for sequences of detection events, with more photon detection
events leading to a larger superposition. We furthermore demonstrate that
`No-Knowledge Feedback' can be easily implemented in this system and used to
preserve the superposition state, as well as provide an extra control mechanism
for state generation.


title:
Evaluable Jones-Wenzl idempotents at root of unity and modular
  representation on the center of U_qsl(2)

abstract:
  Let p an integer. We define a family of idempotents (and nilpotents) in the
Temperley - Lieb algebras at 4p-th roots of unity which generalize the usual
Jones-Wenzl idempotents. These new idempotents correspond to finite dimentional
simple and projective indecomposable representations of the restricted quantum
group Uqsl(2), where q is a 2p-th root of unity. In the manner of the [BHMV95]
topological quantum field theorie (TQFT), they provide a canonical basis in
colored skein modules to define mapping class groups representations. In the
torus case, this basis allows us to obtain a partial match between the negative
twist and the buckling actions, and the [LM94] induced representation of SL2(Z)
on the center of Uqsl(2), which extends non trivially the [RT91] representation
of SL2(Z).


title: Quantum Simulation with a Boson Sampling Circuit

abstract:
  In this work we study a system that consists of $2M$ matter qubits that
interact through a boson sampling circuit, i.e., an $M$-port interferometer,
embedded in two different architectures. We prove that, under the conditions
required to derive a master equation, the qubits evolve according to effective
bipartite XY spin Hamiltonians, with or without local and collective
dissipation terms. This opens the door to the simulation of any bipartite spin
or hard-core boson models and exploring dissipative phase transitions as the
competition between coherent and incoherent exchange of excitations. We also
show that in the purely dissipative regime this model has a large number of
exact and approximate dark states, whose structure and decay rates can be
estimated analytically. We finally argue that this system may be used for the
adiabatic preparation of boson sampling states encoded in the matter qubits.


title: A new concept of a high-energy space-based cosmic ray telescope

abstract:
  Cosmic ray science has proved to be a very active field, with several
important results from recent space-based instruments. Next generation
experiments will explore the multi-TeV energy range, trying to cope with the
mass and power budget constraints of artificial satellites that limits the
collecting area thus reducing the available statistics at the highest energy.
With the aim to improve the compromise between area and mass, we propose a new
concept for a cosmic-ray telescope in which the detector elements are organized
in bars along the 3 axis. In this way we can also maintain a good event shower
sampling (for direction and energy reconstruction) and a relatively small
number of channels (required power) as the detector size increases. A possible
implementation of the concept is also evaluated with a Geant4 simulation.


title: When are n-syzygy modules n-torsionfree?

abstract:
  Let R be a commutative noetherian ring. We consider the question of when
n-syzygy modules over R are n-torsionfree in the sense of Auslander and
Bridger. Our tools include Serre's condition and certain conditions on the
local Gorenstein property of R. Our main result implies the converse of a
celebrated theorem of Evans and Griffith.


title:
All optical implementation of a time-domain ptychographic pulse
  reconstruction set-up

abstract:
  An all optical implementation of pulse reconstruction using time-domain
ptychography is demonstrated showing excellent results. Setup and
reconstruction are easy to implement and a number of drawbacks found in other
second order techniques are removed, such as the beam splitter modifying the
pulse under consideration, the time ambiguity, or the strict correspondence
between time delay increment and temporal resolution. Ptychography generally
performs superior to algorithms based on general projections, requires
considerable less computational effort and is much less susceptible to noise.


title:
The shallow shell approach to Pogorelov's problem and the breakdown of
  `mirror buckling'

abstract:
  We present a detailed asymptotic analysis of the point indentation of an
unpressurized, spherical elastic shell. Previous analyses of this classic
problem have assumed that for sufficiently large indentation depths, such a
shell deforms by `mirror buckling' --- a portion of the shell inverts to become
a spherical cap with equal but opposite curvature to the undeformed shell. The
energy of deformation is then localized in a ridge in which the deformed and
undeformed portions of the shell join together, commonly referred to as
Pogorelov's ridge. Rather than using an energy formulation, we revisit this
problem from the point of view of the shallow shell equations and perform an
asymptotic analysis that exploits the largeness of the indentation depth. This
reveals first that the stress profile associated with mirror buckling is
singular as the indenter is approached. This consequence of point indentation
means that mirror buckling must be modified to incorporate the shell's bending
stiffness close to the indenter and gives rise to an intricate asymptotic
structure with seven different spatial regions. This is in contrast with the
three regions (mirror-buckled, ridge and undeformed) that are usually assumed
and yields new insight into the large compressive hoop stress that ultimately
causes the shell to buckle azimuthally.


title:
Democratic, Existential, and Consensus-Based Output Conventions in
  Stable Computation by Chemical Reaction Networks

abstract:
  We show that some natural output conventions for error-free computation in
chemical reaction networks (CRN) lead to a common level of computational
expressivity. Our main results are that the standard consensus-based output
convention have equivalent computational power to (1) existence-based and (2)
democracy-based output conventions. The CRNs using the former output convention
have only "yes" voters, with the interpretation that the CRN's output is yes if
any voters are present and no otherwise. The CRNs using the latter output
convention define output by majority vote among "yes" and "no" voters.
  Both results are proven via a generalized framework that simultaneously
captures several definitions, directly inspired by a Petri net result of
Esparza, Ganty, Leroux, and Majumder [CONCUR 2015]. These results support the
thesis that the computational expressivity of error-free CRNs is intrinsic, not
sensitive to arbitrary definitional choices.


title: A Practical Approach to Spatiotemporal Data Compression

abstract:
  Datasets representing the world around us are becoming ever more unwieldy as
data volumes grow. This is largely due to increased measurement and modelling
resolution, but the problem is often exacerbated when data are stored at
spuriously high precisions. In an effort to facilitate analysis of these
datasets, computationally intensive calculations are increasingly being
performed on specialised remote servers before the reduced data are transferred
to the consumer. Due to bandwidth limitations, this often means data are
displayed as simple 2D data visualisations, such as scatter plots or images. We
present here a novel way to efficiently encode and transmit 4D data fields
on-demand so that they can be locally visualised and interrogated. This nascent
"4D video" format allows us to more flexibly move the boundary between data
server and consumer client. However, it has applications beyond purely
scientific visualisation, in the transmission of data to virtual and augmented
reality.


title:
Modeling and Analysis of Cellular Networks using Stochastic Geometry: A
  Tutorial

abstract:
  This paper presents a tutorial on stochastic geometry (SG) based analysis for
cellular networks. This tutorial is distinguished by its depth with respect to
wireless communication details and its focus on cellular networks. The paper
starts by modeling and analyzing the baseband interference in a basic cellular
network model. Then, it characterizes signal-to-interference-plus-noise-ratio
(SINR) and its related performance metrics. In particular, a unified approach
to conduct error probability, outage probability, and rate analysis is
presented. Although the main focus of the paper is on cellular networks, the
presented unified approach applies for other types of wireless networks that
impose interference protection around receivers. The paper then extends the
baseline unified approach to capture cellular network characteristics (e.g.,
frequency reuse, multiple antenna, power control, etc.). It also presents
numerical examples associated with demonstrations and discussions. Finally, we
point out future research directions.


title: Droplet deformation and fragmentation by ultra-short laser pulses

abstract:
  We report on the experimental studies of the deformation and fragmentation of
liquid metal droplets by picosecond and subpicosecond laser pulses. The
experiments were performed with laser irradiance varying in 10E13-10E15 W/cm^2
range. The observed evolution of the droplet shape upon the impact dramatically
differs from the previously reported for nanosecond laser pulses. Instead of
flattening the droplet undergoes rapid asymmetric expansion and transforms into
a complex shape which can be interpreted as two conjunct spheroid shells and
finally fragments. We explain the described hydrodynamic response to the
ultra-short impact as a result of the propagation of the laser-induced
convergent shockwave through the volume of droplet.


title:
Nondiffractive feature of $\gamma N\to \rho^\pm N$ with $\rho$-meson
  electromagnetic multipole moments

abstract:
  We investigate photoproduction of charged $\rho$ off the nucleon using
$\rho(770)+\pi(140)$ Regge pole exchanges by considering the $\rho$-meson
electromagnetic multipole moments. The significance of the Ward identity at the
$\gamma\rho\rho$ vertex is emphasized for current conservation in the process.
Given $\pi$ exchange with the well-known coupling constants for $\gamma\pi\rho$
and $\pi NN$, we analyze the role of the $\rho$ exchange in the $\gamma p\to
\rho^+n$ and $\gamma n\to\rho^-p$ processes without model-dependences except
for the magnetic moment $\mu_{\rho^\pm}=\pm2.01$ and electric quadrupole moment
${\cal Q}_{\rho^\pm}=\pm0.027$ fm$^2$ taken from theoretical estimates. The
nondiffractive feature of both cross sections is reproduced with a rapid
decrease beyond the resonance region by the dominance of $\pi$ exchange over
the $\rho$\,. % Cross sections for differential and density matrix elements are
presented to compare with existing data. The parity and photon polarization
asymmetries are predicted to demonstrate the apparent roles of the $\rho$-meson
electromagnetic multipole moments.


title: Learning Social Affordance for Human-Robot Interaction

abstract:
  In this paper, we present an approach for robot learning of social affordance
from human activity videos. We consider the problem in the context of
human-robot interaction: Our approach learns structural representations of
human-human (and human-object-human) interactions, describing how body-parts of
each agent move with respect to each other and what spatial relations they
should maintain to complete each sub-event (i.e., sub-goal). This enables the
robot to infer its own movement in reaction to the human body motion, allowing
it to naturally replicate such interactions.
  We introduce the representation of social affordance and propose a generative
model for its weakly supervised learning from human demonstration videos. Our
approach discovers critical steps (i.e., latent sub-events) in an interaction
and the typical motion associated with them, learning what body-parts should be
involved and how. The experimental results demonstrate that our Markov Chain
Monte Carlo (MCMC) based learning algorithm automatically discovers
semantically meaningful interactive affordance from RGB-D videos, which allows
us to generate appropriate full body motion for an agent.


title: Universal three-body physics in ultracold KRb mixtures

abstract:
  Ultracold atomic gases have recently become a driving force in few-body
physics due to the observation of the Efimov effect. While initially observed
in equal mass systems, one expects even richer few-body physics in the
heteronuclear case. In previous experiments with ultracold mixtures of
potassium and rubidium, an unexpected non-universal behavior of Efimov
resonances was observed. In contrast, we measure the scattering length
dependent three-body recombination coefficient in ultracold heteronuclear
mixtures of $^{39}\mathrm{K}$-\87Rb and $^{41}\mathrm{K}$-\87Rb and do not
observe any signatures of Efimov resonances for accessible scattering lengths
in either mixture. Our results show good agreement with our theoretical model
for the scattering dependent three-body recombination coefficient and
reestablish universality across isotopic mixtures.


title:
Investigation on Radio Wave Propagation in Shallow Seawater: Simulations
  and Measurements

abstract:
  The authors present full wave simulations and experimental results of
propagation of electromagnetic waves in shallow seawaters. Transmitter and
receiver antennas are ten-turns loops placed on the seabed. Some propagation
frameworks are presented and simulated. Finally, simulation results are
compared with experimental ones.


title:
Spatially Common Sparsity Based Adaptive Channel Estimation and Feedback
  for FDD Massive MIMO

abstract:
  This paper proposes a spatially common sparsity based adaptive channel
estimation and feedback scheme for frequency division duplex based massive
multi-input multi-output (MIMO) systems, which adapts training overhead and
pilot design to reliably estimate and feed back the downlink channel state
information (CSI) with significantly reduced overhead. Specifically, a
non-orthogonal downlink pilot design is first proposed, which is very different
from standard orthogonal pilots. By exploiting the spatially common sparsity of
massive MIMO channels, a compressive sensing (CS) based adaptive CSI
acquisition scheme is proposed, where the consumed time slot overhead only
adaptively depends on the sparsity level of the channels. Additionally, a
distributed sparsity adaptive matching pursuit algorithm is proposed to jointly
estimate the channels of multiple subcarriers. Furthermore, by exploiting the
temporal channel correlation, a closed-loop channel tracking scheme is
provided, which adaptively designs the non-orthogonal pilot according to the
previous channel estimation to achieve an enhanced CSI acquisition. Finally, we
generalize the results of the multiple-measurement-vectors case in CS and
derive the Cramer-Rao lower bound of the proposed scheme, which enlightens us
to design the non-orthogonal pilot signals for the improved performance.
Simulation results demonstrate that the proposed scheme outperforms its
counterparts, and it is capable of approaching the performance bound.


title: BRST Symmetry: Boundary Conditions and Edge States in QED

abstract:
  In manifolds with spatial boundary, BRST formalism can be used to quantize
gauge theories. We show that, in a $U(1)$ gauge theory, only a subset of all
the boundary conditions allowed by the self-adjointness of the Hamiltonian
preserves BRST symmetry. Hence, the theory can be quantized using BRST
formalism only when that subset of boundary conditions is considered. We also
show that for such boundary conditions, there exist fermionic states which are
localized near the boundary.

categories: hep-th cond-mat.other cond-mat.supr-con math-ph math.MP


title:
Ultrafast spin density wave transition in Chromium governed by
  thermalized electron gas

abstract:
  The energy and momentum selectivity of time- and angle-resolved photoemission
spectroscopy is exploited to address the ultrafast dynamics of the
antiferromagnetic spin density wave (SDW) transition photoexcited in epitaxial
thin films of chromium. We are able to quantitatively extract the evolution of
the SDW order parameter $\Delta$ through the ultrafast phase transition.
$\Delta$ is defined by the transient temperature of the thermalized electron
gas. The complete destruction of SDW order on a sub-100~fs time scale is
observed, much faster than for conventional charge density wave materials. Our
results reveal that equilibrium concepts for phase transitions such as the
order parameter may be utilized even in the strongly non-adiabatic regime of
ultrafast photo-excitation.


title:
Frequency-domain equalization aided iterative detection of
  faster-than-Nyquist signaling with noise whitening

abstract:
  In this paper, we propose a serially concatenated turbo-encoded
faster-than-Nyquist signaling (FTNS) transceiver that takes into account
FTNS-specific colored noise effects. The proposed low-complexity receiver
carries out soft-decision frequency-domain equalization with the aid of the
minimum-mean square error criterion while whitening the colored noise.
Simulation results demonstrate that the proposed multi-stage-concatenated FTNS
system achieves a better error-ratio performance than previous systems that do
not consider colored noise effects in the high-symbol-packing FTNS regime.
Furthermore, as an explicit benefit of the proposed iterative decoder,
near-capacity performance is achieved with practical decoding complexity.


title:
Selective excitation in a three-state system using a hybrid
  adiabatic-nonadiabatic interaction

abstract:
  The chirped-pulse interaction in the adiabatic coupling regime induces cyclic
permutations of the energy states of a three-level system in the $V$-type
configuration, which process is known as the three-level chirped rapid
adiabatic passage. Here we show that a spectral hole in a chirped pulse can
turn on and off one of the two adiabatic crossing points of this process,
reducing the system to an effective two-level system. The given hybrid
adiabatic-nonadiabatic transition results in selective excitation of the
three-level system, controlled by the laser intensity and spectral position of
the hole as well as the sign of the chirp parameter. Experiments are performed
with shaped femtosecond laser pulses and the three lowest energy-levels
(5S$_{1/2}$, 5P$_{1/2}$, and 5P$_{3/2}$) of atomic rubidium ($^{85}$Rb), of
which the result shows good agreement with the theoretically analyzed dynamics.
The result indicates that our method, being combined with the ordinary
chirped-RAP, implements an adiabatic transitions between the two excited
states. Furthermore the laser intensity-dependent control may have applications
including selective excitations of atoms or ions arranged in space when being
used in conjunction with laser beam profile programming.


title:
Interactions and thermoelectric effects in a parallel-coupled double
  quantum dot

abstract:
  We investigate the nonequilibrium transport properties of a double quantum
dot system connected in parallel to two leads, including intradot
electron-electron interaction. In the absence of interactions the system
supports a bound state in the continuum. This state is revealed as a Fano
antiresonance in the transmission when the energy levels of the dots are
detuned. Using the Keldysh nonequilibrium Green's function formalism, we find
that the occurrence of the Fano antiresonance survives in the presence of
Coulomb repulsion. We give precise predictions for the experimental detection
of bound states in the continuum. First, we calculate the differential
conductance as a function of the applied voltage and the dot level detuning and
find that crossing points in the diamond structure are revealed as minima due
to the transmission antiresonances. Second, we determine the thermoelectric
current in response to an applied temperature bias. In the linear regime,
quantum interference gives rise to sharp peaks in the thermoelectric
conductance. Remarkably, we find interaction induced strong current
nonlinearities for large thermal gradients that may lead to several nontrivial
zeros in the thermocurrent. The latter property is especially attractive for
thermoelectric applications.


title: Birth of String Theory

abstract:
  This is a brief summary of an introductory lecture for students and scholars
in general given by the author at Nambu Memorial Symposium which was held at
Osaka City University on September 29, 2015. We review the invention of string
theory by Professor Yoichiro Nambu following the discovery of the Veneziano
amplitude. We also discuss Professor Nambu's proposal on string theory in the
Schild gauge in 1976 which is related to the matrix model of Yang-Mills type.


title:
A new computation of the critical point for the planar random-cluster
  model with $q\ge1$

abstract:
  We present a new computation of the critical value of the random-cluster
model with cluster weight $q\ge 1$ on $\mathbb{Z}^2$. This provides an
alternative approach to the result of Beffara and Duminil-Copin. We believe
that this approach has several advantages. First, most of the proof can easily
be extended to other planar graphs with sufficient symmetries. Furthermore, it
invokes RSW-type arguments which are not based on self-duality. And finally, it
contains a new way of applying sharp threshold results which avoid the use of
symmetric events and periodic boundary conditions.


title:
A communication-avoiding parallel algorithm for the symmetric eigenvalue
  problem

abstract:
  Many large-scale scientific computations require eigenvalue solvers in a
scaling regime where efficiency is limited by data movement. We introduce a
parallel algorithm for computing the eigenvalues of a dense symmetric matrix,
which performs asymptotically less communication than previously known
approaches. We provide analysis in the Bulk Synchronous Parallel (BSP) model
with additional consideration for communication between a local memory and
cache. Given sufficient memory to store $c$ copies of the symmetric matrix, our
algorithm requires $\Theta(\sqrt{c})$ less interprocessor communication than
previously known algorithms, for any $c\leq p^{1/3}$ when using $p$ processors.
The algorithm first reduces the dense symmetric matrix to a banded matrix with
the same eigenvalues. Subsequently, the algorithm employs successive reduction
to $O(\log p)$ thinner banded matrices. We employ two new parallel algorithms
that achieve lower communication costs for the full-to-band and band-to-band
reductions. Both of these algorithms leverage a novel QR factorization
algorithm for rectangular matrices.


title:
A catalogue of early-type emission-line stars and H{\alpha} line
  profiles from LAMOST DR2

abstract:
  We present a catalogue including 11,204 spectra for 10,436 early-type
emission-line stars from LAMOST DR2, among which 9,752 early-type emission-line
spectra are newly discovered. For these early-type emission-line stars, we
discuss the morphological and physical properties from their low-resolution
spectra. In this spectral sample, the H$\alpha$ emission profiles display a
wide variety of shapes. Based on the H$\alpha$ line profiles, these spectra are
categorized into five distinct classes: single-peak emission, single-peak
emission in absorption, double-peak emission, double-peak emission in
absorption, and P-Cygni profiles. To better understand what causes the
H$\alpha$ line profiles, we divide these objects into four types from the view
of physical classification, which include classical Be stars, Herbig Ae/Be
stars, close binaries and spectra contaminated by HII regions. The majority of
Herbig Ae/Be stars and classical Be stars are identified and separated using
the (H-K, K-W1) color-color diagram. We also discuss thirty one binary systems
as listed in SIMBAD on-line catalogue and identify 3,600 spectra contaminated
by HII regions after cross matching with positions in the Dubout-Crillon
catalogue. A statistical analysis of line profiles versus classifications is
then conducted in order to understand the distribution of H$\alpha$ profiles
for each type in our sample. Finally, we also provide a table of 172 spectra
with FeII emission lines and roughly calculate stellar wind velocities for
seven spectra with P-Cygni profiles.


title:
Integrability of geodesics and action-angle variables in Sasaki-Einstein
  space $T^{1,1}$

abstract:
  We briefly describe the construction of St\"{a}\-kel-Killing and Killing-Yano
tensors on toric Sasaki-Einstein manifolds without working out intricate
generalized Killing equations. The integrals of geodesic motions are expressed
in terms of Killing vectors and Kill\-ing-Yano tensors of the homogeneous
Sasaki-Einstein space $T^{1,1}$. We discuss the integrability of geodesics and
construct explicitly the action-angle variables. Two pairs of frequencies of
the geodesic motions are resonant giving way to chaotic behavior when the
system is perturbed.


title:
Magnon spin transport driven by the magnon chemical potential in a
  magnetic insulator

abstract:
  We develop a linear-response transport theory of diffusive spin and heat
transport by magnons in magnetic insulators with metallic contacts. The magnons
are described by a position dependent temperature and chemical potential that
are governed by diffusion equations with characteristic relaxation lengths.
Proceeding from a linearized Boltzmann equation, we derive expressions for
length scales and transport coefficients. For yttrium iron garnet (YIG) at room
temperature we find that long-range transport is dominated by the magnon
chemical potential. We compare the model's results with recent experiments on
YIG with Pt contacts [L.J. Cornelissen, et al., Nat. Phys. 11, 1022 (2015)] and
extract a magnon spin conductivity of $\sigma_{m}=5\times10^{5}$ S/m. Our
results for the spin Seebeck coefficient in YIG agree with published
experiments. We conclude that the magnon chemical potential is an essential
ingredient for energy and spin transport in magnetic insulators.


title: Perfect powers in products of terms of elliptic divisibility sequences

abstract:
  Diophantine problems involving recurrence sequences have a long history and
is an actively studied topic within number theory. In this paper, we connect to
the field by considering the equation \begin{align*} B_mB_{m+d}\dots
B_{m+(k-1)d}=y^\ell \end{align*} in positive integers $m,d,k,y$ with
$\gcd(m,d)=1$ and $k\geq 2$, where $\ell\geq 2$ is a fixed integer and
$B=(B_n)_{n=1}^\infty$ is an elliptic divisibility sequence, an important class
of non-linear recurrences. We prove that the above equation admits only
finitely many solutions. In fact, we present an algorithm to find all possible
solutions, provided that the set of $\ell$-th powers in $B$ is given. (Note
that this set is known to be finite.) We illustrate our method by an example.


title: Free-space quantum signatures using heterodyne detection

abstract:
  Digital signatures guarantee the authorship of electronic communications.
Currently used "classical" signature schemes rely on unproven computational
assumptions for security, while quantum signatures rely only on the laws of
quantum mechanics. Previous quantum signature schemes have used unambiguous
quantum measurements. Such measurements, however, sometimes give no result,
reducing the efficiency of the protocol. Here, we instead use heterodyne
detection, which always gives a result, although there is always some
uncertainty. We experimentally demonstrate feasibility in a real environment by
distributing signature states through a noisy 1.6km free-space channel. Our
results show that continuous-variable heterodyne detection improves the
signature rate for this type of scheme and therefore represents an interesting
direction in the search for practical quantum signature schemes.


title: Experimental testbed for seawater channel characterization

abstract:
  Shallow seawaters are problematic for acoustic and optical communications.
Sensor networks based on electromagnetic (EM) communications are evaluated in
this environment. In order to characterize the subaquatic channel, several
measurement systems have been designed, built and tested in the sea obtaining
very reliable results. Experiments carried out with dipoles and loop antennas
showed serious disagreement with the state of the art, especially when dipole
antennas are used. Dipoles performance was poor while magnetic loops showed
relevant results. Measurement system is described in detail and real
attenuation of the subaquatic channel is obtained for several distances and
antennas. Finally, measured and simulated results are compared with good
agreement.


title: Peculiar spaces of relativistic quantum fields

abstract:
  We study how quantum field theory models are modified under the
reparametrizations of the space-time coordinates and some simultaneous
transformations of the field function. The transformations that turn the action
of the massive field in the Minkowski space-time into the action of the
massless field in some curved space are presented.


title: Nondoubling Calder\'on-Zygmund theory -a dyadic approach-

abstract:
  Given a measure $\mu$ of polynomial growth, we refine a deep result by David
and Mattila to construct an atomic martingale filtration of
$\mathrm{supp}(\mu)$ which provides the right framework for a dyadic form of
nondoubling harmonic analysis. Despite this filtration being highly irregular,
its atoms are comparable to balls in the given metric |which in turn are all
doubling| and satisfy a weaker but crucial form of regularity. Our dyadic
formulation is effective to address three basic questions:
  i) A dyadic form of Tolsa's RBMO space which contains it.
  ii) Lerner's domination and $A_2$-type bounds for nondoubling measures.
  iii) A noncommutative form of nonhomogeneous Calder\'on-Zygmund theory.
  Our martingale RBMO space preserves the crucial properties of Tolsa's
original definition and reveals its interpolation behavior with the $L_p$ scale
in the category of Banach spaces, unknown so far. On the other hand, due to
some known obstructions for Haar shifts and related concepts over nondoubling
measures, our pointwise domination theorem via sparsity naturally deviates from
its doubling analogue. In a different direction, matrix-valued harmonic
analysis over noncommutative $L_p$ spaces has recently produced profound
applications. Our analogue for nondoubling measures was expected for quite some
time. Finally, we also find a dyadic form of the Calder\'on-Zygmund
decomposition which unifies those by Tolsa and
L\'opez-S\'anchez/Martell/Parcet.


title:
Quantum thermodynamics in chiral two--level systems. The quantum
  stochastic resonance

abstract:
  A Langevin canonical framework for a chiral two-level system coupled to a
bath of harmonic oscillators is used within a coupling scheme different from
the well-known spin-boson model. From this stochastic dynamics, within the
Markovian regime and Ohmic friction, some standard quantum thermodynamics
functions such as the energy average and heat capacity can be extracted. In
particular, special emphasis is put on the so-called quantum stochastic
resonance which is a cooperative effect of friction, noise and periodic driving
occurring in a bistable system.


title: Vector-boson production in p--Pb collisions with ALICE at the LHC

abstract:
  ALICE (A Large Ion Collider Experiment) is designed and optimized to study
ultra-relativistic heavy-ion collisions at the LHC, in which a hot and dense,
strongly-interacting medium is created. Vector bosons (W and Z) are produced in
hard scattering processes and interact weakly with the medium formed in
heavy-ion collisions. Thus, they present a suitable reference for processes
which are heavily affected by the medium. In proton-nucleus collisions their
production can be used to study the modification of parton distribution
functions in the nucleus and to test the validity of binary-collision scaling
for hard processes. The production of W and Z bosons is studied in p--Pb
collisions at a centre-of-mass energy of $\sqrt {s_{\rm NN}}$ = 5.02 TeV with
the ALICE muon spectrometer at forward ($2.03 < \mathit{y}^{\mu}_{\textrm{cms}}
< 3.53$) and backward ($-4.46< \mathit{y}^{\mu}_{\textrm{cms}} <-2.96$)
rapidity. W bosons are studied via the inclusive single muon differential
$p_{\rm T}$ spectrum whereas the Z-boson signal is observed in the invariant
mass distribution of unlike-sign muon pairs as a peak around the Z-boson mass.
In this presentation the measured cross sections of W and Z bosons and the
W-boson yield per centrality interval will be discussed. The cross-sections are
compared to theoretical calculations.


title: A global observer for attitude and gyro biases from vector measurements

abstract:
  We consider the classical problem of estimating the attitude and gyro biases
of a rigid body from vector measurements and a triaxial rate gyro. We propose a
simple "geometry-free" nonlinear observer with guaranteed uniform global
asymptotic convergence and local exponential convergence; the stability
analysis, which relies on a strict Lyapunov function, is rather simple. The
excellent behavior of the observer is illustrated through a detailed numerical
simulation.


title:
On the asymptotic stability in the energy space for multi-solitons of
  the Landau-Lifshitz equation

abstract:
  We establish the asymptotic stability of multi-solitons for the
one-dimensional Landau-Lifshitz equation with an easy-plane anisotropy. The
solitons have non-zero speed, are ordered according to their speeds and have
sufficiently separated initial positions. We provide the asymptotic stability
around solitons and between solitons. More precisely, we show that for an
initial datum close to a sum of $N$ dark solitons, the corresponding solution
converges weakly to one of the solitons in the sum, when it is translated to
the centre of this soliton, and converges weakly to zero when it is translated
between solitons.


title: Small minimal $(3, 3)$-Ramsey graphs

abstract:
  We say that $G$ is a $(3, 3)$-Ramsey graph if every $2$-coloring of the edges
of $G$ forces a monochromatic triangle. The $(3, 3)$-Ramsey graph $G$ is
minimal if $G$ does not contain a proper $(3, 3)$-Ramsey subgraph. In this work
we find all minimal $(3, 3)$-Ramsey graphs with up to 13 vertices with the help
of a computer, and we obtain some new results for these graphs. We also obtain
new upper bounds on the independence number and new lower bounds on the minimum
degree of arbitrary $(3, 3)$-Ramsey graphs.


title: Real Space Renormalization Group Theory of Disordered Models of Glasses

abstract:
  We develop a real space renormalisation group analysis of disordered models
of glasses, in particular of the spin models at the origin of the Random First
Order Transition theory. We find three fixed points respectively associated to
the liquid state, to the critical behavior and to the glass state. The latter
two are zero-temperature ones; this provides a natural explanation of the
growth of effective activation energy scale and the concomitant huge increase
of relaxation time approaching the glass transition. The lower critical
dimension depends on the nature of the interacting degrees of freedom and is
higher than three for all models. This does not prevent three dimensional
systems from being glassy. Indeed, we find that their renormalisation group
flow is affected by the fixed points existing in higher dimension and in
consequence is non-trivial. Within our theoretical framework the glass
transition results to be an avoided phase transition.


title:
Stabilization of the tetragonal structure in
  (Ba$_{1-x}$Sr$_{x}$)CuSi$_{2}$O$_{6}$

abstract:
  We present a structural analysis of the substituted system
(Ba$_{1-x}$Sr$_{x}$)CuSi$_{2}$O$_{6}$, which reveals a stable tetragonal
crystal structure down to 1.5 K. We explore the structural details with
lowtemperature neutron and synchrotron powder diffraction, room-temperature and
cryogenic highresolution NMR, as well as magnetic- and specific-heat
measurements and verify that a structural phase transition into the
orthorhombic structure which occurs in the parent compound BaCuSi2O6, is absent
for the x = 0.1 sample. Furthermore, synchrotron powder-diffraction patterns
show a reduction of the unit cell for x = 0.1 and magnetic measurements prove
that the Cu-dimers are preserved, yet with a slightly reduced intradimer
coupling Jintra. Pulse-field magnetization measurements reveal the emergence of
a field-induced ordered state, tantamount to Bose-Einsteincondensation (BEC) of
triplons, within the tetragonal crystal structure of $I\,4_{1}/acd$. This
material offers the opportunity to study the critical properties of triplon
condensation in a simple crystal structure.


title:
The Equatorial Current Sheet and other interesting features of the
  Pulsar Magnetosphere

abstract:
  We want to understand what drives magnetospheric dissipation in the
equatorial current sheet. Numerical simulations have limitations and, unless we
have a clear a priori understanding of the physical processes involved, their
results can be misleading. We argue that the canonical pulsar magnetosphere is
strongly dissipative and that a large fraction (up to 30-40% in an aligned
rotator) of the spindown luminosity is redirected towards the equator where it
is dissipated into particle acceleration and emission of radiation. We show
that this is due to the failure of the equatorial electric current to cross the
Y-point at the tip of the corotating zone.


title: About the Structure of a General Equation of State for Liquids and Gases

abstract:
  It is shown that the functional form of the equation of state of [4-8] is not
correct in general case.


title: Plasmonics of opalic surface: a combined near-and far-field approach

abstract:
  An opalic plasmonic sample, constituted by a hexagonal arrangement of
metallized silica spheres, presents remarkable optical properties due to the
mixing of periodic arrangement and singularities at the sphere touching points.
It is therefore an interesting candidate for exploiting the excitation of both
localized and propagating surface plasmons. Several channels of excitation
based on these properties or exploiting a certain level of disorder are
evidenced, opening new routes for the efficient excitation of plasmons on a
wide spectral range. The versatility of such hybrid system is evidenced in the
context of two complementary experiments: specular reflective spectrometry and
photoemission electron microscopy. Both techniques offer different points of
view on the same physical phenomenon and the link between them is discussed.
Such experiments evidence the opportunities offered by these 2D hybrid
materials in the context of nanophotonics.


title:
Gate-tunable transport properties of in-situ capped Bi$_2$Te$_3$
  topological insulator thin films

abstract:
  Combining the ability to prepare high-quality, intrinsic Bi$_2$Te$_3$
topological insulator thin films of low carrier density with in-situ protective
capping, we demonstrate a pronounced, gate-tunable change in transport
properties of Bi$_2$Te$_3$ thin films. Using a back-gate, the carrier density
is tuned by a factor of $\sim 7$ in Al$_2$O$_3$ capped Bi$_2$Te$_3$ sample and
by a factor of $\sim 2$ in Te capped Bi$_2$Te$_3$ films. We achieve full
depletion of bulk carriers, which allows us to access the topological transport
regime dominated by surface state conduction. When the Fermi level is placed in
the bulk band gap, we observe the presence of two coherent conduction channels
associated with the two decoupled surfaces. Our magnetotransport results show
that the combination of capping layers and electrostatic tuning of the Fermi
level provide a technological platform to investigate the topological
properties of surface states in transport experiments and pave the way towards
the implementation of a variety of topological quantum devices.


title: Affine Hirsch foliations on 3-manifolds

abstract:
  This paper is devoted to discussing affine Hirsch foliations on
$3$-manifolds. First, we prove that up to isotopic leaf-conjugacy, every closed
orientable $3$-manifold $M$ admits $0$, $1$ or $2$ affine Hirsch foliations.
Furthermore, every case is possible.
  Then, we analyze the $3$-manifolds admitting two affine Hirsch foliations
(abbreviated as Hirsch manifolds). On the one hand, we construct Hirsch
manifolds by using exchangeable braided links (abbreviated as DEBL Hirsch
manifolds); on the other hand, we show that every Hirsch manifold virtually is
a DEBL Hirsch manifold.
  Finally, we show that for every $n\in \mathbb{N}$, there are only finitely
many Hirsch manifolds with strand number $n$. Here the strand number of a
Hirsch manifold $M$ is a positive integer defined by using strand numbers of
braids.


title:
Sunspot numbers based on historic records in the 1610s - early
  telescopic observations by Simon Marius and others

abstract:
  Hoyt & Schatten (1998) claim that Simon Marius would have observed the sun
from 1617 Jun 7 to 1618 Dec 31 (Gregorian calendar) all days, except three
short gaps in 1618, but would never have detected a sunspot -- based on a
quotation from Marius in Wolf (1857), but misinterpreted by Hoyt & Schatten.
Marius himself specified in early 1619 that "for one and a half year ... rather
few or more often no spots could be detected ... which was never observed
before" (Marius 1619). The generic statement by Marius can be interpreted such
that the active day fraction was below 0.5 (but not zero) from fall 1617 to
spring 1619 and that it was 1 before fall 1617 (since August 1611). Hoyt &
Schatten cite Zinner (1952), who referred to Zinner (1942), where observing
dates by Marius since 1611 are given, but which were not used by Hoyt &
Schatten. We present all relevant texts from Marius where he clearly stated
that he observed many spots in different form on and since 1611 Aug 3 (Julian)
= Aug 13 (Greg.) (on the first day together with Ahasverus Schmidnerus), 14
spots on 1612 May 30 (Julian) = Jun 9 (Greg.), which is consistent with
drawings by Galilei and Jungius for that day, the latter is shown here for the
first time, at least one spot on 1611 Oct 3 and/or 11 (Julian), i.e. Oct 13
and/or 21 (Greg.), when he changed his sunspot observing technique, he also
mentioned that he has drawn sunspots for 1611 Nov 17 (Julian) = Nov 27 (Greg.),
in addition to those clearly datable detections, there is evidence in the texts
for regular observations. ... Sunspots records by Malapert from 1618 to 1621
show that the last low-latitude spot was seen in Dec 1620, while the first
high-latitude spots were noticed in June and Oct 1620, so that the Schwabe
cycle turnover (minimum) took place around that time, ...


title:
Dissipative Bose-Einstein condensation in contact with a thermal
  reservoir

abstract:
  We investigate the real-time dynamics of open quantum spin-$1/2$ or hardcore
boson systems on a spatial lattice, which are governed by a Markovian quantum
master equation. We derive general conditions under which the hierarchy of
correlation functions closes such that their time evolution can be computed
semi-analytically. Expanding our previous work [Phys. Rev. A 93, 021602 (2016)]
we demonstrate the universality of a purely dissipative quantum Markov process
that drives the system of spin-$1/2$ particles into a totally symmetric
superposition state, corresponding to a Bose-Einstein condensate of hardcore
bosons. In particular, we show that the finite-size scaling behavior of the
dissipative gap is independent of the chosen boundary conditions and the
underlying lattice structure. In addition, we consider the effect of a uniform
magnetic field as well as a coupling to a thermal bath to investigate the
susceptibility of the engineered dissipative process to unitary and nonunitary
perturbations. We establish the nonequilibrium steady-state phase diagram as a
function of temperature and dissipative coupling strength. For a small number
of particles $N$, we identify a parameter region in which the engineered
symmetrizing dissipative process performs robustly, while in the thermodynamic
limit $N\rightarrow \infty$, the coupling to the thermal bath destroys any
long-range order.