title:
Nine years of multi-frequency monitoring of the blazar PKS 0048-097:
  spectral and temporal variability

abstract:
  Blazars are highly variable, radio-loud active galactic nuclei with jets
oriented at a small angle to the line of sight. The observed emission of these
sources covers the whole electromagnetic spectrum from radio frequencies up to
the high or even very high energy gamma-ray range. To understand the complex
physics of these objects, multi-wavelength observations and studies on the
variability and correlations between different wavelengths are therefore
essential. The long-term multi-frequency observations of PKS 0048-097 are
analysed here to investigate its spectral and temporal features. The studies
includes nine years of observations of the blazar, which is well studied in the
optical and radio domain, but not in the other frequencies. Multi-wavelength
data collected with OVRO, KAIT, Catalina, Swift/UVOT, Swift/XRT and Fermi/LAT
were studied. The performed analysis revealed strong variability in all
wavelengths that is most clearly manifested in the X-ray range. The correlation
studies do not exhibit any relation between different wavelengths, except for
the very strong positive correlation between the optical emission in V and R
bands.


title:
A copula-based model for multivariate ordinal panel data: application to
  well-being composition

abstract:
  A novel copula-based multivariate panel ordinal model is developed to
estimate structural relations among components of well-being. Each ordinal
time-series is modelled using a copula-based Markov model to relate the
marginal distributions of the response at each time of observation and then, at
each observation time, the conditional distributions of each ordinal
time-series are joined using a multivariate t copula. Maximum simulated
likelihood based on evaluating the multidimensional integrals of the likelihood
with randomized quasi Monte Carlo methods is used for the estimation.
Asymptotic calculations show that our method is nearly as efficient as maximum
likelihood for fully specified multivariate copula models. Our findings
highlight the importance of one's relative position in evaluating their
well-being with no direct effects of socio-economic characteristics on
well-being but strong indirect effects through their impact on components of
well-being. Temporal resilience, habit formation and behavioural traits can
explain the dependence in the joint tails over time and across well-being
components.


title:
Imprints of a high velocity wind on the soft x-ray spectrum of PG
  1211+143

abstract:
  An extended XMM-Newton observation of the luminous narrow line Seyfert galaxy
PG 1211+143 in 2014 has revealed a more complex high velocity wind, with
components distinguished in velocity, ionization level, and column density.
Here we report soft x-ray emission and absorption features from the ionized
outflow, finding counterparts of both high velocity components, v ~ 0.129c and
v ~ 0.066c, recently identified in the highly ionized Fe K absorption spectrum.
The lower ionization of the co-moving soft x-ray absorbers imply a distribution
of higher density clouds embedded in the main outflow, while much higher column
densities for the same flow component in the hard x-ray spectra suggest
differing sight lines to the continuum x-ray source.


title:
Permanental Point Processes on Real Tori, Theta Functions and
  Monge-Amp\`ere Equations

abstract:
  Inspired by constructions in complex geometry we introduce a thermodynamic
framework for Monge-Amp\`ere equations on real tori. We show convergence in law
of the associated point processes and explain connections to complex
Monge-Amp\`ere equations and optimal transport.


title:
Predicting the size of droplets produced through Laplace pressure
  induced snap-off

abstract:
  Laplace pressure driven snap-off is a technique that is used to produce
droplets for emulsions and microfluidics purposes. Previous predictions of
droplet size have assumed a quasi-equilibrium low flow limit. We present a
simple model to predict droplet sizes over a wide range of flow rates,
demonstrating a rich landscape of droplet stability depending on droplet size
and growth rate. The model accounts for the easily adjusted experimental
parameters of geometry, interfacial tension, and the viscosities of both
phases.


title:
Design of nanobeam photonic crystal resonators for a
  silicon-on-lithium-niobate platform

abstract:
  We outline the design for a photonic crystal resonator made in a hybrid
Silicon/Lithium Niobate material system. Using the index contrast between
silicon and lithium niobate, it is possible to guide and confine photonic
resonances in a thin film of silicon bonded on top of lithium niobate. Quality
factors greater than $10^6$ at optical wavelength scale mode volumes are
achievable. We show that patterning electrodes on such a system can yield an
electro-optic coupling rate of 0.6 GHz/V (4 pm/V).


title: A consensus-based model for global optimization and its mean-field limit

abstract:
  We introduce a novel first-order stochastic swarm intelligence (SI) model in
the spirit of consensus formation models, namely a consensus-based optimization
(CBO) algorithm, which may be used for the global optimization of a function in
multiple dimensions. The CBO algorithm allows for passage to the mean-field
limit, which results in a nonstandard, nonlocal, degenerate parabolic partial
differential equation (PDE). Exploiting tools from PDE analysis we provide
convergence results that help to understand the asymptotic behavior of the SI
model. We further present numerical investigations underlining the feasibility
of our approach.


title: Decentralized Consensus Algorithm with Delayed and Stochastic Gradients

abstract:
  We analyze the convergence of decentralized consensus algorithm with delayed
gradient information across the network. The nodes in the network privately
hold parts of the objective function and collaboratively solve for the
consensus optimal solution of the total objective while they can only
communicate with their immediate neighbors. In real-world networks, it is often
difficult and sometimes impossible to synchronize the nodes, and therefore they
have to use stale gradient information during computations. We show that, as
long as the random delays are bounded in expectation and a proper diminishing
step size policy is employed, the iterates generated by decentralized gradient
descent method converge to a consensual optimal solution. Convergence rates of
both objective and consensus are derived. Numerical results on a number of
synthetic problems and real-world seismic tomography datasets in decentralized
sensor networks are presented to show the performance of the method.


title: Unveiling The Physics of Star Formation and Feedback in Galaxies

abstract:
  Recent studies show the importance of feedback in the evolution of the star
formation rate in the Universe. However, the nature and physics of the feedback
are still pressing questions. Radio continuum observations can provide unique
dust-unbiased tracers of massive star formation and of the interstellar medium
(ISM) and hence are ideal to address the regulation of star formation in
galaxies. Our multi-frequency and multi-resolution radio surveys in nearby
galaxies enable us to trace various phases of star formation and dissect the
thermal and nonthermal ISM in galaxies. Mapping the cosmic ray electron energy
index and magnetic field strength, we have found observational evidence that
massive star formation significantly affects the energy balance in the ISM
through the injection and acceleration of cosmic rays and the amplification of
magnetic fields. How the next generation of stars could form in such a
magnetized and turbulent ISM will be addressed in our 'EVLA cloud-scale survey
of the local group galaxy M33' and in forthcoming surveys with the SKA.


title: Is the exotic $X(5568)$ a bound state?

abstract:
  Stimulated by the recent observation of the exotic $X(5568)$ state by D0
Collaboration, we study the four-quark system $us\bar{b}\bar{d}$ with quantum
numbers $J^P=0^+$ in the framework of chiral quark model. Two structures,
diquark-antidiquark and meson-meson, with all possible color configurations are
investigated by using Gaussian expansion method. The results show that energies
of the tetraquark states with diquark-antiquark structure are too high to the
candidate of $X(5568)$, and no molecular structure can be formed in our
calculations. The calculation is also extended to the four-quark system
$us\bar{c}\bar{d}$ and the same results as that of $us\bar{b}\bar{d}$ are
obtained.


title: Steady states of continuous-time open quantum walks

abstract:
  Continuous-time open quantum walks (CTOQW) are introduced as the formulation
of quantum dynamical semigroups of trace-preserving and completely positive
linear maps (or quantum Markov semigroups) on graphs. We show that a CTOQW
always converges to a steady state regardless of the initial state when a graph
is connected. When the graph is both connected and regular, it is shown that
the steady state is the maximally mixed state. As shown by the examples in this
article, the steady states of CTOQW can be very unusual and complicated even
though the underlying graphs are simple. The examples demonstrate that the
structure of a graph can affect quantum coherence in CTOQW through a long time
run. Precisely, the quantum coherence persists throughout the evolution of the
CTOQW when the underlying topology is certain irregular graphs (such as a path
or a star as shown in the examples). In contrast, the quantum coherence will
eventually vanish from the open quantum system when the underlying topology is
a regular graph (such as a cycle).


title:
A computational approach for mode isolation for reaction-diffusion
  systems on arbitrary geometries

abstract:
  In this article we present a computational framework for isolating spatial
patterns arising in the steady states of reaction-diffusion systems. Such
systems have been used to model many different phenomena in areas such as
developmental and cancer biology, cell motility and material science. Often one
is interested in identifying parameters which will lead to a particular
pattern. To attempt to answer this, we compute eigenpairs of the Laplacian on a
variety of domains and use linear stability analysis to determine parameter
values for the system that will lead to spatially inhomogeneous steady states
whose patterns correspond to particular eigenfunctions. This method has
previously been used on domains and surfaces where the eigenvalues and
eigenfunctions are found analytically in closed form. Our contribution to this
methodology is that we numerically compute eigenpairs on arbitrary domains and
surfaces. Here we present various examples and demonstrate that mode isolation
is straightforward especially for low eigenvalues. Additionally we see that if
two or more eigenvalues are in a permissible range then the inhomogeneous
steady state can be a linear combination of the respective eigenfunctions.
Finally we show an example which suggests that pattern formation is robust on
similar surfaces in cases that the surface either has or does not have a
boundary.


title: Counting problem on wind-tree models

abstract:
  We study periodic wind-tree models, billiards in the plane endowed with
$\mathbb{Z}^2$-periodically located identical connected symmetric right-angled
obstacles. We show asymptotic formulas for the number of (isotopy classes of)
closed billiard trajectories (up to $\mathbb{Z}^2$-translations) on the
wind-tree billiard. We also compute explicitly the associated Siegel-Veech
constant for generic wind-tree billiards depending on the number of corners on
the obstacle.


title: Quantum computation and communication in strongly interacting systems

abstract:
  Each year, the gap between theoretical proposals and experimental endeavours
to create quantum computers gets smaller, driven by the promise of
fundamentally faster algorithms and quantum simulations. This occurs by the
combination of experimental ingenuity and ever simpler theoretical schemes.
This thesis comes from the latter perspective, aiming to find new, simpler ways
in which components of a quantum computer could be built. We first search for
ways to create quantum gates, the primitive building blocks of a quantum
computer. We find a novel, low-control way of performing a two-qubit gate on
qubits encoded in a decoherence-free subspace, making use of many-body
interactions that may already be present. This includes an analysis of the
effect of control errors and magnetic field fluctuations on the gate. We then
present novel ways to create three-qubit Toffoli and Fredkin gates in a single
step using linear arrays of qubits, including an assessment of how well these
gates could perform, for quantum or classical computation, using
state-of-the-art ion trap and silicon donor technology. We then focus on a very
different model from the normal circuit model, combining ideas from
measurement-based quantum computation (MBQC) and holonomic quantum computation,
showing that all MBQC patterns with a property called \emph{gflow} can be
converted into a holonomic computation. The manifestation of the properties of
MBQC in this adiabatically driven model is then explored. Finally, we
investigate ways in which quantum information can be communicated between
distant parties, using minimally engineered spin chains. The viability of using
1D Wigner crystals as a quantum channel is analysed, as well as schemes using
ideal uniform spin chains with next-neighbour interactions, and edge-locking
effects.


title: Enhanced superconductivity in atomically thin TaS2

abstract:
  The ability to exfoliate layered materials down to the single layer limit has
opened the opportunity to understand how a gradual reduction in dimensionality
affects the properties of bulk materials. Here we use this top-down approach to
address the problem of superconductivity in the two-dimensional limit. The
transport properties of electronic devices based on 2H tantalum disulfide
flakes of different thicknesses are presented. We observe that
superconductivity persists down to the thinnest layer investigated (3.5 nm),
and interestingly, we find a pronounced enhancement in the critical temperature
from 0.5 K to 2.2 K as the layers are thinned down. In addition, we propose a
tight-binding model, which allows us to attribute this phenomenon to an
enhancement of the effective electron-phonon coupling constant. This work
provides evidence that reducing dimensionality can strengthen superconductivity
as opposed to the weakening effect that has been reported in other 2D materials
so far.


title: Formal Design of Robot Integrated Task and Motion Planning

abstract:
  Integrated Task and Motion Planning (ITMP) for mobile robots in a dynamic
environment with moving obstacles is a challenging research question and
attracts more and more attentions recently. Most existing methods either
restrict to static environments or lack performance guarantees. This motivates
us to investigate the ITMP problem using formal methods and propose a bottom-up
compositional design approach called CoSMoP (Composition of Safe Motion
Primitives). Our basic idea is to synthesize a global motion plan through
composing simple local moves and actions, and to achieve its performance
guarantee through modular and incremental verifications. The design consists of
two steps. First, basic motion primitives are designed and verified locally.
Then, a global motion path is built upon these certified motion primitives by
concatenating them together. In particular, we model the motion primitives as
hybrid automata and verify their safety through formulating as Differential
Dynamic Logic (d$\mathcal{L}$). Furthermore, these proven safe motion
primitives are composed based on an encoding to Satisfiability Modulo Theories
(SMT) that takes into account the geometric constraints. Since d$\mathcal{L}$
allows compositional verification, the sequential composition of the safe
motion primitives also preserves safety properties. Therefore, the CoSMoP
generates correct plans for given task specifications that are formally proven
safe even for moving obstacles. Illustrative examples are presented to show the
effectiveness of the methods.


title: Sequential Monte Carlo Smoothing with Parameter Estimation

abstract:
  We propose two new Bayesian smoothing methods for general state-space models
with unknown parameters. The first approach is based on the particle learning
and smoothing algorithm, but with an adjustment in the backward resampling
weights. The second is a new method combining sequential parameter learning and
smoothing algorithms for general state-space models. This method is
straightforward but effective, and we find it is the best existing Sequential
Monte Carlo algorithm to solve the joint Bayesian smoothing problem. We first
illustrate the methods on three benchmark models using simulated data, and then
apply them to a stochastic volatility model for daily S&P 500 index returns
during the financial crisis.


title: One-Way Quantum Computer Simulation

abstract:
  In one-way quantum computation (1WQC) model, universal quantum computations
are performed using measurements to designated qubits in a highly entangled
state. The choices of bases for these measurements as well as the structure of
the entanglements specify a quantum algorithm. As scalable and reliable quantum
computers have not been implemented yet, quantum computation simulators are the
only widely available tools to design and test quantum algorithms. However,
simulating the quantum computations on a standard classical computer in most
cases requires exponential memory and time. In this paper, a general direct
simulator for 1WQC, called OWQS, is presented. Some techniques such as qubit
elimination, pattern reordering and implicit simulation of actions are used to
considerably reduce the time and memory needed for the simulations. Moreover,
our simulator is adjusted to simulate the measurement patterns with a
generalized flow without calculating the measurement probabilities which is
called extended one-way quantum computation simulator (EOWQS). Experimental
results validate the feasibility of the proposed simulators and that OWQS and
EOWQS are faster as compared with the well-known quantum circuit simulators,
i.e., QuIDDPro and libquantum for simulating 1WQC model.


title:
Comment on two papers claiming records for the lowest carrier
  concentration at which superconductivity has been observed

abstract:
  A recent paper and a preprint both claim records for the lowest carrier
concentration at which superconductivity has been observed. However colleagues
in Australia and I found evidence for superconductivity at concentrations of
the order of at least a hundred times lower in the 1980's, in a ceramic sample
of SrTiO_3 with 3% of Ti replaced by Zr.


title:
Objective Bayesian Analysis of the Yule-Simon Distribution with
  Applications

abstract:
  The Yule-Simon distribution is usually employed in the analysis of frequency
data. As the Bayesian literature, so far, ignored this distribution, here we
show the derivation of two objective priors for the parameter of the Yule-Simon
distribution. In particular, we discuss the Jeffreys prior and a loss-based
prior, which has recently appeared in the literature. We illustrate the
performance of the derived priors through a simulation study and the analysis
of real datasets.


title:
Mid-infrared surface plasmon polariton chemical sensing on fiber-coupled
  ITO coated glass

abstract:
  A novel fiber-coupled ITO coated glass slide sensor for performing surface
plasmon polariton chemical monitoring in the 3.5 um mid-IR range is reported.
Efficient mid-IR fiber coupling is achieved with 3D laser written waveguides,
and the coupling of glass waveguide modes to ITO SPPs is driven by the varying
phase matching conditions of different aqueous analytes across the anomalous
dispersion range determined by their molecular fingerprints. By means of using
both a mid-IR fiber supercontinuum source and a diode laser the excitation of
SPPs is demonstrated. The efficient optical monitoring of mid-IR SPPs in smart
glass could have a broad range of applications in biological and chemical
sensing.


title:
Three-input Majority Function as the Unique Optimal Function for the
  Bias Amplification using Nonlocal Boxes

abstract:
  Brassard et al. [Phys. Rev. Lett. 96, 250401 (2006)] showed that shared
nonlocal boxes with the CHSH probability greater than $\frac{3+\sqrt{6}}6$
yields trivial communication complexity. There still exists the gap with the
maximum CHSH probability $\frac{2+\sqrt{2}}4$ achievable by quantum mechanics.
It is an interesting open question to determine the exact threshold for the
trivial communication complexity. Brassard et al.'s idea is based on the
recursive bias amplification by the 3-input majority function. It was not
obvious if other choice of function exhibits stronger bias amplification. We
show that the 3-input majority function is the unique optimal, so that one
cannot improve the threshold $\frac{3+\sqrt{6}}6$ by Brassard et al.'s bias
amplification. In this work, protocols for computing the function used for the
bias amplification are restricted to be non-adaptive protocols or particular
adaptive protocol inspired by Paw{\l}owski et al.'s protocol for information
causality [Nature 461, 1101 (2009)]. We first show a new adaptive protocol
inspired by Paw{\l}owski et al.'s protocol, and then show that the new adaptive
protocol is better than any non-adaptive protocol. Finally, we show that the
3-input majority function is the unique optimal for the bias amplification if
we apply the new adaptive protocol to each step of the bias amplification.


title: Spectral analysis of two-dimensional Bose-Hubbard models

abstract:
  One-dimensional Bose-Hubbard models are well known to obey a transition from
regular to quantum-chaotic spectral statistics. We are extending this concept
to relatively simple two-dimensional many-body models. Also in two dimensions a
transition from regular to chaotic spectral statistics is found and discussed.
In particular, we analyze the dependence of the spectral properties on the bond
number of the two-dimensional lattices and the applied boundary conditions. For
maximal connectivity, the systems behave most regularly in agreement with the
applicability of mean-field approaches in the limit of many nearest-neighbor
couplings at each site.


title: On some pointwise inequalities involving nonlocal operators

abstract:
  The purpose of this paper is three-fold: first, we survey on several known
pointwise identities involving fractional operators; second, we propose a
unified way to deal with those identities; third, we prove some new pointwise
identities in different frameworks in particular geometric and
infinite-dimensional ones.


title: Propagation of heavy baryons in heavy-ion collisions

abstract:
  The drag and diffusion coefficients of heavy baryons ($\Lambda_c$ and
$\Lambda_b$) in the hadronic phase created in the latter stage of the heavy-ion
collisions at RHIC and LHC energies have been evaluated recently. In this work
we compute some experimental observables, such as the nuclear suppression
factor $R_{AA}$ and the elliptic flow $v_2$ of heavy baryons at RHIC and LHC
energies, highlighting the role of the hadronic phase contribution to these
observables, which are going to be measured at Run 3 of LHC. For the time
evolution of the heavy quarks in the QGP and heavy baryons in the hadronic
phase we use the Langevin dynamics. For the hadronization of the heavy quarks
to heavy baryons we employ Peterson fragmentation functions. We observe a
strong suppression of both the $\Lambda_c$ and $\Lambda_b$. We find that the
hadronic medium has a sizable impact on the heavy-baryon elliptic flow whereas
the impact of hadronic medium rescattering is almost unnoticeable on the
nuclear suppression factor. We evaluate the $\Lambda_c/D$ ratio at RHIC and
LHC. We find that $\Lambda_c/D$ ratio remain unaffected due to the hadronic
phase rescattering which enable it as a nobel probe of QGP phase dynamics along
with its hadronization.


title:
Time-dependent suppression of oscillatory power in evolving solar
  magnetic fields

abstract:
  Oscillation amplitudes are generally smaller within magnetically active
regions like sunspots and plage, when compared to their surroundings. Such
magnetic features, when viewed in spatially-resolved powermaps, appear as
regions of suppressed power due to reductions in the oscillation amplitudes.
Employing high spatial- and temporal-resolution observations from the Dunn
Solar Telescope (DST) in New Mexico, we study the power suppression in a region
of evolving magnetic fields adjacent to a pore. By utilising wavelet analysis,
we study for the first time, how the oscillatory properties in this region
change as the magnetic field evolves with time. Image sequences taken in the
blue continuum, G-band, Ca~\textsc{ii}~K and H$\alpha$ filters were used in
this study. It is observed that the suppression found in the chromosphere
occupies a relatively larger area confirming previous findings. Also, the
suppression is extended to structures directly connected to the magnetic region
and is found to get enhanced as the magnetic field strength increased with
time. The dependence of the suppression on the magnetic field strength is
greater at longer periods and higher formation heights. Furthermore, the
dominant periodicity in the chromosphere was found to be anti-correlated with
increases in the magnetic field strength.


title: Wiretapped Oblivious Transfer

abstract:
  In this paper, we study the problem of obtaining $1$-of-$2$ string oblivious
transfer (OT) between users Alice and Bob, in the presence of a passive
eavesdropper Eve. The resource enabling OT in our setup is a noisy broadcast
channel from Alice to Bob and Eve. Apart from the OT requirements between the
users, Eve is not allowed to learn anything about the users' inputs. When Alice
and Bob are honest-but-curious and the noisy broadcast channel is made up of
two independent binary erasure channels (connecting Alice-Bob and Alice-Eve),
we derive the $1$-of-$2$ string OT capacity for both $2$-privacy (when Eve can
collude with either Alice or Bob) and $1$-privacy (when no such collusion is
allowed). We generalize these capacity results to $1$-of-$N$ string OT and
study other variants of this problem. When Alice and/or Bob are malicious, we
present a different scheme based on interactive hashing. This scheme is shown
to be optimal for certain parameter regimes. We present a new formulation of
multiple, simultaneous OTs between Alice-Bob and Alice-Cathy. For this new
setup, we present schemes and outer bounds that match in all but one regime of
parameters. Finally, we consider the setup where the broadcast channel is made
up of a cascade of two independent binary erasure channels (connecting
Alice-Bob and Bob-Eve) and $1$-of-$2$ string OT is desired between Alice and
Bob with $1$-privacy. For this setup, we derive an upper and lower bound on the
$1$-of-$2$ string OT capacity which match in one of two possible parameter
regimes.


title: Particle Physics and Condensed Matter: The Saga Continues

abstract:
  Ideas from quantum field theory and topology have proved remarkably fertile
in suggesting new phenomena in the quantum physics of condensed matter. Here
I'll supply some broad, unifying context, both conceptual and historical, for
the abundance of results reported at the Nobel Symposium on "New Forms of
Matter, Topological Insulators and Superconductors". Since they distill some
most basic ideas in their simplest forms, these concluding remarks might also
serve, for non-specialists, as an introduction.


title: Spatial Distribution of Pair Production over the Pulsar Polar Cap

abstract:
  Using an analytic, axisymmetric approach that includes general relativity,
coupled to a condition for pair production deduced from simulations, we derive
general results about the spatial distribution of pair-producing field lines
over the pulsar polar cap. In particular, we show that pair production on
magnetic field lines operates over only a fraction of the polar cap for an
aligned rotator for general magnetic field configurations, assuming the
magnetic field varies spatially on a scale that is larger than the size of the
polar cap. We compare our result to force-free simulations of a pulsar with a
dipole surface field and find excellent agreement. Our work has implications
for first-principles simulations of pulsar magnetospheres, and for explaining
observations of pulsed radio and high-energy emission.


title: Sums involving the number of distinct prime factors function

abstract:
  The main object of this paper is to find closed form expressions for finite
and infinite sums that are weighted by $\omega(n)$, where $\omega(n)$ is the
number of distinct prime factors of $n$. We then derive general convergence
criteria for these series. The approach of this paper is use polynomial
theorems to prove several factorization identities for arbitrary complex
numbers, then apply these identities with arbitrary primes and values of
multiplicative functions evaluated at primes. This allows us to reinterpret
sums over arbitrary complex numbers as divisor sums and sums over the natural
numbers.


title: Risk Aversion and Catastrophic Risks: the Pill Experiment

abstract:
  This article focuses on the work of O. Chanel and G. Chichilnisky (2013) on
the flaws of expected utility theory while assessing the value of life.
Expected utility is a fundamental tool in decision theory. However, it does not
fit with the experimental results when it comes to catastrophic outcomes
---see, for example, Chichilnisky (2009) for more details. In the experiments
conducted by Olivier Chanel in 1998 and 2009, several subjects are ask to
imagine they are presented 1 billion identical pills. They are paid \$220,000
to take and swallow one, knowing that one out of 1 billion is deadly. The
objective of this article is to show that risk aversion phenomenon cannot
explain the experimental results found. This is an additional reason why a new
kind of utility function is necessary: the axioms proposed by Graciela
Chichilnisky will be briefly presented, and it will be shown that it better
fits with experiments than any risk aversion utility function.


title: The $K$-Theory of Finitely Many Commuting Endomorphisms

abstract:
  For a field $k$ we compute the $K$-theory of the exact category of
$k[t_1,\dots,t_n]$-modules that are finite-dimensional over $k$, generalising
the work of Kelley and Spanier.


title: Archaeoastronomy in the Khmer heartland

abstract:
  The heartland of the Khmer empire is literally crowded by magnificent
monuments built in the course of many centuries. These monuments include the
world-famous state-temples, such as Angkor Wat, but also many other temples and
huge water reservoirs. Using Google Earth data as well as GIS data and
reconstructing the ancient sky with Stellarium, we investigate here on the
relationships of astronomy with orientation and topography in a systematic
fashion, following the methods of modern Archaeoastronomy and strictly keeping
at a bay vague or esoteric proposals put forward by many authors in the past.
As a result, a very clear pattern of cardinal orientation and alignment arises,
connected with the temple's symbolism and the management of power by the Khmer
kings. As a bonus, the comparison with the Angkor monuments allows to put
forward a explanation for the anomalous orientation of the unique two
peripheral state temples of Cambodia.


title:
Multiverse effects on the CMB angular correlation function in the
  framework of NCG

abstract:
  Following many theories that predict the existence of the multiverse and by
conjecture that our space-time may have a generalized geometrical structure at
the fundamental level, we are interested in using a non-commutative geometry
(NCG) formalism to study a suggested two-layer space that contains our
4-dimensional (4-D) universe and a re-derived photon propagator. It can be
shown that the photon propagator and a cosmic microwave background (CMB)
angular correlation function are comparable, and if there exists such a
multiverse system, the distance between the two layers can be estimated to be
within the observable universe's radius. Furthermore, this study revealed that
our results are not limited to CMB but can be applied to many other types of
radiation, such as X-rays.


title:
Scientific Computing, High-Performance Computing and Data Science in
  Higher Education

abstract:
  We present an overview of current academic curricula for Scientific
Computing, High-Performance Computing and Data Science. After a survey of
current academic and non-academic programs across the globe, we focus on
Canadian programs and specifically on the education program of the SciNet HPC
Consortium, using its detailed enrollment and course statistics for the past
four to five years. Not only do these data display a steady and rapid increase
in the demand for research-computing instruction, they also show a clear shift
from traditional (high performance) computing to data-oriented methods. It is
argued that this growing demand warrants specialized research computing
degrees. The possible curricula of such degrees are described next, taking
existing programs as an example, and adding SciNet's experiences of student
desires as well as trends in advanced research computing.


title:
Stable Aqueous Dispersions of Optically and Electronically Active
  Phosphorene

abstract:
  Understanding and exploiting the remarkable optical and electronic properties
of phosphorene require mass production methods that avoid chemical degradation.
While solution-based strategies have been developed for scalable exfoliation of
black phosphorus, these techniques have thus far employed anhydrous organic
solvents in an effort to minimize exposure to known oxidants, but at the cost
of limited exfoliation yield and flake size distribution. Here, we present an
alternative phosphorene production method based on surfactant-assisted
exfoliation and post-processing of black phosphorus in deoxygenated water. From
comprehensive microscopic and spectroscopic analysis, this approach is shown to
yield phosphorene dispersions that are stable, highly concentrated, and
comparable to micromechanically exfoliated phosphorene in structure and
chemistry. Due to the high exfoliation efficiency of this process, the
resulting phosphorene flakes are thinner than anhydrous organic solvent
dispersions, thus allowing the observation of layer-dependent photoluminescence
down to the monolayer limit. Furthermore, to demonstrate preservation of
electronic properties following solution processing, the aqueous-exfoliated
phosphorene flakes are employed in field-effect transistors with high drive
currents and current modulation ratios. Overall, this method enables the
isolation and mass production of few-layer phosphorene, which will accelerate
ongoing efforts to realize a diverse range of phosphorene-based applications.


title: Lie algebras and torsion groups with identity

abstract:
  We prove that a finitely generated Lie algebra $L$ such that (i) every
commutator in generators is ad-nilpotent, and (ii) $ L$ satisfies a polynomial
identity, is nilpotent. As a corollary we get that a finitely generated
residually-$p$ torsion group whose pro-$p$ completion satisfies a pro-$p$
identity is finite.


title: Quantum and Classical Phases in Optomechanics

abstract:
  The control of quantum systems requires the ability to change and read-out
the phase of a system. The non-commutativity of canonical conjugate operators
can induce phases on quantum systems, which can be employed for implementing
phase gates and for precision measurements. Here we study the phase acquired by
a radiation field after its radiation pressure interaction with a mechanical
oscillator, and compare the classical and quantum contributions. The classical
description can reproduce the nonlinearity induced by the mechanical oscillator
and the loss of correlations between mechanics and optical field at certain
interaction times. Such features alone are therefore insufficient for probing
the quantum nature of the interaction. Our results thus isolate genuine quantum
contributions of the optomechanical interaction that could be probed in current
experiments.


title:
On Medium Chemical Reaction in Diffusion-Based Molecular Communication:
  a Two-Way Relaying Example

abstract:
  Chemical reactions are a prominent feature of molecular communication (MC)
systems, with no direct parallels in wireless communications. While chemical
reactions may be used inside the transmitter nodes, receiver nodes or the
communication medium, we focus on its utility in the medium in this paper. Such
chemical reactions can be used to perform computation over the medium as
molecules diffuse and react with each other (physical-layer computation). We
propose the use of chemical reactions for the following purposes: (i) to reduce
signal-dependent observation noise of receivers by reducing the signal density,
(ii) to realize molecular physical-layer network coding (molecular PNC) by
performing the natural XOR operation inside the medium, and (iii) to reduce the
inter-symbol interference (ISI) of other transmitters by canceling out the
remaining molecules from previous transmissions. To make the ideas formal, we
consider an explicit two-way relaying example with a transparent receiver
(which has a signal-dependent noise). The proposed ideas are used to define a
modulation scheme (which we call the PNC scheme). We compare the PNC with a
previously proposed scheme for this problem where the XOR operation is
performed at the relay node (using a molecular logic gate). We call the latter,
the straightforward network coding (SNC). It is observed that in addition to
the simplicity of the proposed PNC scheme, it outperforms the SNC scheme
especially when we consider ISI.


title: Automorphisms of fusion systems of sporadic simple groups

abstract:
  We prove here that with a very small number of exceptions, when $G$ is a
sporadic simple group and $p$ is a prime such that the Sylow $p$-subgroups of
$G$ are nonabelian, then $Out(G)$ is isomorphic to the outer automorphism
groups of the fusion and linking systems of $G$. In particular, the $p$-fusion
system of $G$ is tame in the sense of [AOV1], and is tamely realized by $G$
itself except when $G\cong M_{11}$ and $p=2$. From the point of view of
homotopy theory, these results also imply that $Out(G)\cong Out(BG^\wedge_p)$
in many (but not all) cases.


title:
H2O masers in a jet-driven bowshock: Episodic ejection from a massive
  young stellar object

abstract:
  We report the results of VERA multi-epoch VLBI 22 GHz water maser
observations of S255IR-SMA1, a massive young stellar object located in the S255
star forming region. By annual parallax the source distance was measured as D =
1.78 +-0.12 kpc and the source systemic motion was (u alpha cos d, u d) =
(-0.13 +- 0.20, -0.06 +- 0.27) mas yr-1. Masers appear to trace a U-shaped bow
shock whose morphology and proper motions are well reproduced by a jet-driven
outflow model with a jet radius of about 6 AU. The maser data, in the context
of other works in the literature, reveal ejections from S255IR-SMA1 to be
episodic, operating on timescales of ~1000 years.


title: Beyond Quartic Hamiltonians

abstract:
  We investigate the Hamiltonian system generated by a homogeneous binary
polynomial $U$ of order greater than four. In particular, we study the
circumstances under which the associated Hessian is a Weierstrass $\wp$
function and find that the vanishing of two covariants of $U$ is involved.


title: Structural properties of close II$_1$ factors

abstract:
  We show that a number of key structural properties transfer between
sufficiently close II$_1$ factors, including solidity, strong solidity,
uniqueness of Cartan masas and property $\Gamma$. We also examine II$_1$
factors close to tensor product factors, showing that such factors also
factorise as a tensor product in a fashion close to the original.


title: Structure models: from shell model to ab initio methods

abstract:
  A brief review of models to describe nuclear structure and reactions
properties is presented, starting from the historical shell model picture and
encompassing modern ab initio approaches. A selection of recent theoretical
results on observables for exotic light and medium-mass nuclei is shown.
Emphasis is given to the comparison with experiment and to what can be learned
about three-body forces and continuum properties.


title:
Two-dimensional phosphorus carbide: Competition between sp2 and sp3
  bonding

abstract:
  We propose previously unknown allotropes of phosphorus carbide (PC) in the
stable shape of an atomically thin layer. Different stable geometries, which
result from the competition between sp2 bonding found in graphitic C and sp3
bonding found in black P, may be mapped onto 2D tiling patterns that simplify
categorizing of the structures. Depending on the category, we identify 2D-PC
structures that can be metallic, semi-metallic with an anisotropic Dirac cone,
or direct-gap semiconductors with their gap tunable by in-layer strain.


title:
Modeling the initiation of the 2006 December 13 coronal mass ejection in
  AR 10930: the structure and dynamics of the erupting flux rope

abstract:
  We carry out a three-dimensional magneto-hydrodynamic (MHD) simulation to
model the initiation of the coronal mass ejection (CME) on 13 December 2006 in
the emerging {\delta}-sunspot active region NOAA 10930. The setup of the
simulation is similar to a previous simulation by Fan (2011), but with a
significantly widened simulation domain to accommodate the wide CME. The
simulation shows that the CME can result from the emergence of a east-west
oriented twisted flux rope whose positive, following emerging pole corresponds
to the observed positive rotating sunspot emerging against the southern edge of
the dominant pre-existing negative sunspot. The erupting flux rope in the
simulation accelerates to a terminal speed that exceeds 1500 km/s and undergoes
a counter-clockwise rotation of nearly 180 degrees such that its front and
flanks all exhibit southward directed magnetic fields, explaining the observed
southward magnetic field in the magnetic cloud impacting the Earth. With
continued driving of flux emergence, the source region coronal magnetic field
also shows the reformation of a coronal flux rope underlying the flare current
sheet of the erupting flux rope, ready for a second eruption. This may explain
the build up for another X-class eruptive flare that occurred the following day
from the same region.


title: Lorentz atom revisited by solving Abraham-Lorentz equation of motion

abstract:
  By solving the non-relativistic Abraham-Lorentz (AL) equation, I demonstrate
that AL equation of motion is not suited for treating the Lorentz atom, because
a steady-state solution does not exist. The AL equation serves as a tool,
however, for deducing appropriate parameters $\Omega,\Gamma$ to be used with
the equation of forced oscillations in modelling the Lorentz atom. The electric
polarizability, which many authors "derived" from AL equation in recent years,
is found to violate Kramers-Kronig relations rendering obsolete the extracted
photon-absorption rate, for example. Fortunately, errors turn out to be small
quantitatively, as long as light frequency $\omega$ is neither too close to nor
too far from resonance frequency $\Omega$. Polarizability and absorption cross
section are derived for the Lorentz atom by purely classical reasoning and
shown to agree with quantum-mechanical calculations of the same quantities. In
particular, oscillator parameters $\Omega,\,\Gamma$ deduced by treating the
atom as a quantum oscillator are found equivalent to those derived from
classical AL equation. The instructive comparison provides a deep insight into
understanding the great success of Lorentz's model which was suggested long
before the advent of quantum theory.


title: Accurate Online Full Charge Capacity Modeling of Smartphone Batteries

abstract:
  Full charge capacity (FCC) refers to the amount of energy a battery can hold.
It is the fundamental property of smartphone batteries that diminishes as the
battery ages and is charged/discharged. We investigate the behavior of
smartphone batteries while charging and demonstrate that the battery voltage
and charging rate information can together characterize the FCC of a battery.
We propose a new method for accurately estimating FCC without exposing
low-level system details or introducing new hardware or system modules. We also
propose and implement a collaborative FCC estimation technique that builds on
crowdsourced battery data. The method finds the reference voltage curve and
charging rate of a particular smartphone model from the data and then compares
the curve and rate of an individual user with the model reference curve. After
analyzing a large data set, we report that 55% of all devices and at least one
device in 330 out of 357 unique device models lost some of their FCC. For some
models, the median capacity loss exceeded 20% with the inter-quartile range
being over 20 pp. The models enable debugging the performance of smartphone
batteries, more accurate power modeling, and energy-aware system or application
optimization.


title: New ambiguity in probing CP violation in neutrino oscillations

abstract:
  If neutrinos get mass via the seesaw mechanism the mixing matrix describing
neutrino oscillations can be effectively non-unitary. We show that in this case
the neutrino appearance probabilities involve a new CP phase, phi, associated
to non-unitarity. This leads to an ambiguity in extracting the "standard"
three--neutrino phase delta_CP, which can survive even after neutrino and
antineutrino channels are combined. Its existence should be taken into account
in the planning of any oscillation experiment aiming at a robust measurement of
delta_CP.


title:
On the Effect of Rotation on Populations of Classical Cepheids II.
  Pulsation Analysis for Metallicities 0.014, 0.006, and 0.002

abstract:
  Classical Cepheid variable stars are high-sensitivity probes of stellar
evolution and fundamental tracers of cosmic distances. While rotational mixing
significantly affects the evolution of Cepheid progenitors (intermediate-mass
stars), the impact of the resulting changes in stellar structure and
composition on Cepheids on their pulsational properties is hitherto unknown.
Here we present the first detailed pulsational instability analysis of stellar
evolution models that include the effects of rotation, for both fundamental
mode and first overtone pulsation. We employ Geneva evolution models spanning a
three-dimensional grid in mass (1.7 - 15 $M_\odot$), metallicity (Z = 0.014,
0.006, 0.002), and rotation (non-rotating, average & fast rotation). We
determine (1) hot and cool instability strip (IS) boundaries taking into
account the coupling between convection and pulsation, (2) pulsation periods,
and (3) rates of period change. We investigate relations between period and (a)
luminosity, (b) age, (c) radius, (d) temperature, (e) rate of period change,
(f) mass, (g) the flux-weighted gravity-luminosity relation (FWGLR). We
confront all predictions aside from those for age with observations, finding
generally excellent agreement. We tabulate period-luminosity relations (PLRs)
for several photometric pass-bands and investigate how the finite IS width,
different IS crossings, metallicity, and rotation affect PLRs. We show that a
Wesenheit index based on H, V, and I photometry is expected to have the
smallest intrinsic PLR dispersion. We confirm that rotation resolves the
Cepheid mass discrepancy. Period-age relations depend significantly on rotation
(rotation increases Cepheid ages), offering a straightforward explanation for
evolved stars in binary systems that cannot be matched by conventional
isochrones assuming a single age. Finally, we show that Cepheids obey a tight
FWGLR.


title:
Proving the Incompatibility of Efficiency and Strategyproofness via SMT
  Solving

abstract:
  Two important requirements when aggregating the preferences of multiple
agents are that the outcome should be economically efficient and the
aggregation mechanism should not be manipulable. In this paper, we provide a
computer-aided proof of a sweeping impossibility using these two conditions for
randomized aggregation mechanisms. More precisely, we show that every efficient
aggregation mechanism can be manipulated for all expected utility
representations of the agents' preferences. This settles an open problem and
strengthens a number of existing theorems, including statements that were shown
within the special domain of assignment. Our proof is obtained by formulating
the claim as a satisfiability problem over predicates from real-valued
arithmetic, which is then checked using an SMT (satisfiability modulo theories)
solver. In order to verify the correctness of the result, a minimal
unsatisfiable set of constraints returned by the SMT solver was translated back
into a proof in higher-order logic, which was automatically verified by an
interactive theorem prover. To the best of our knowledge, this is the first
application of SMT solvers in computational social choice.


title: The higher sharp II: on $M_2^\#$

abstract:
  We establish the descriptive set theoretic representation of the mouse
$M_n^{\#}$, which is called $0^{(n+1)\#}$. This part partially deals with the
case $n=2$ by proving the many-one equivalence of $M_2^{\#}$ and the theory of
$L_{\boldsymbol{\delta}^1_3}[T_3]$ with the higher level analogs of
$L$-indiscernibles.


title: Proximal Distance Algorithms: Theory and Examples

abstract:
  Proximal distance algorithms combine the classical penalty method of
constrained minimization with distance majorization. If $f(\boldsymbol{x})$ is
the loss function, and $C$ is the constraint set in a constrained minimization
problem, then the proximal distance principle mandates minimizing the penalized
loss $f(\boldsymbol{x})+\frac{\rho}{2}\mathop{dist}(x,C)^2$ and following the
solution $\boldsymbol{x}_{\rho}$ to its limit as $\rho$ tends to $\infty$. At
each iteration the squared Euclidean distance
$\mathop{dist}(\boldsymbol{x},C)^2$ is majorized by the spherical quadratic $\|
\boldsymbol{x}-P_C(\boldsymbol{x}_k)\|^2$, where $P_C(\boldsymbol{x}_k)$
denotes the projection of the current iterate $\boldsymbol{x}_k$ onto $C$. The
minimum of the surrogate function
$f(\boldsymbol{x})+\frac{\rho}{2}\|\boldsymbol{x}-P_C(\boldsymbol{x}_k)\|^2$ is
given by the proximal map $\mathop{prox}_{\rho^{-1}f}[P_C(\boldsymbol{x}_k)]$.
The next iterate $\boldsymbol{x}_{k+1}$ automatically decreases the original
penalized loss for fixed $\rho$. Since many explicit projections and proximal
maps are known, it is straightforward to derive and implement novel
optimization algorithms in this setting. These algorithms can take hundreds if
not thousands of iterations to converge, but the stereotyped nature of each
iteration makes proximal distance algorithms competitive with traditional
algorithms. For convex problems, we prove global convergence. Our numerical
examples include a) linear programming, b) nonnegative quadratic programming,
c) projection to the closest kinship matrix, d) projection onto a second-order
cone constraint, e) calculation of Horn's copositive matrix index, f) linear
complementarity programming, and g) sparse principal components analysis. The
proximal distance algorithm in each case is competitive or superior in speed to
traditional methods.


title: Special subgroups of gyrogroups: Commutators, nuclei and radical

abstract:
  A gyrogroup is a nonassociative group-like structure modelled on the space of
relativistically admissible velocities with a binary operation given by
Einstein's velocity addition law. In this article, we present a few of groups
sitting inside a gyrogroup $G$, including the commutator subgyrogroup, the left
nucleus, and the radical of $G$. The normal closure of the commutator
subgyrogroup, the left nucleus, and the radical of $G$ are in particular normal
subgroups of $G$. We then give a criterion to determine when a subgyrogroup $H$
of a finite gyrogroup $G$, where the index $[G\colon H]$ is the smallest prime
dividing $|G|$, is normal in $G$.


title: Downlink Transmit Power Setting in LTE HetNets with Carrier Aggregation

abstract:
  Carrier aggregation, which allows users to aggregate several component
carriers to obtain up to 100 MHz of band- width, is one of the central features
envisioned for next generation cellular networks. While this feature will
enable support for higher data rates and improve quality of service, it may
also be employed as an effective interference mitigation technique, especially
in multi-tier heterogeneous networks. Having in mind that the aggregated
component carriers may belong to different frequency bands and, hence, have
varying propagation profiles, we argue that it is not necessary, indeed even
harmful, to transmit at maximum power at all carriers, at all times. Rather, by
using game theory, we design a distributed algorithm that lets eNodeBs and
micro base stations dynamically adjust the downlink transmit power for the
different component carriers. We compare our scheme to different power
strategies combined with popular interference mitigation techniques, in a
typical large-scale scenario, and show that our solution significantly
outperforms the other strategies in terms of global network utility, power
consumption and user throughput.


title: A new proof to the energy conservation for the Navier-Stokes equations

abstract:
  In this paper we give a new proof to the energy conservation for the weak
solutions of the incompressible Navier-Stokes equations. This result was first
proved by Shinbrot. The new proof relies on a lemma introduced by Lions.


title:
Cromlech, menhirs and celestial sphere: an unusual representation of the
  Lorentz group

abstract:
  We present a novel representation of the Lorentz group, the geometric version
of which uses "reversions" of a sphere while the algebraic version uses
pseudounitary 2x2 matrices over complex numbers and quaternions, and Clifford
algebras in general. A remarkably simple formula for relativistic composition
of velocities and an accompanying geometric construction follows. The method is
derived from the diffeomorphisms of the celestial sphere induced by Lorentz
boost.


title:
Absorption of acoustic phonons in Fluorinated Carbon Nanotubes with
  non-parabolic, double periodic band

abstract:
  We studied theoretically the absorption of acoustic phonons in the hypersound
regime in Fluorine modified Carbon Nanotube (F-CNT) $\Gamma_q^{F-CNT}$ and
compared it to that of undoped Single Walled Nanotube (SWNT) $\Gamma_q^{SWNT}$.
Per the numerical analysis, the F-CNT showed less absorption to that of SWNT
thus $\vert\Gamma_q^{F-CNT}\vert < \vert\Gamma_q^{SWNT}\vert $. This is due to
the fact that Fluorine is highly electronegative and weakens the walls of the
SWNT. Thus, the $\pi$-electrons associated with to the Fluorine which causes
less free charge carriers to interact with the phonons and hence changing the
metallic properties of the SWNT to semiconductor by the doping process. From
the graphs obtained, the ratio of hypersound absorption in SWNT to F-CNT at $T
= 45K$ is $\frac{\Gamma_{(SWNT)}}{\Gamma_{(F-CNT)}}\approx 29$ whilst at $T =
55K$, is $\frac{\Gamma_{(SWNT)}}{\Gamma_{(F-CNT)}}\approx 9$ and at $T = 65K$,
is $\frac{\Gamma_{(SWNT)}}{\Gamma_{(F-CNT)}}\approx 2$. Clearly, the ratio
decreases as the temperature increases.


title:
An X-Band Waveguide Measurement Technique for the Accurate
  Characterization of Materials with Low Dielectric Loss Permittivity

abstract:
  In this work, we present a new X-band waveguide (WR90) measurement method
that permits the broadband characterization of the complex permittivity for low
dielectric loss tangent material specimens with improved accuracy. An
electrically-long polypropylene specimen that partially fills the cross-section
is inserted into the waveguide and the transmitted scattering parameter (S21)
is measured. The extraction method relies on computational electromagnetic
simulations, coupled with a genetic algorithm, to match the experimental S21
measurement. The sensitivity of the technique to sample length was explored by
simulating specimen lengths from 2.54 to 15.24 cm, in 2.54 cm increments.
Analysis of our simulated data predicts the technique will have the sensitivity
to measure loss tangent values on the order of 10e-3 for materials such as
polymers with relatively low real permittivity values. The ability to
accurately characterize low-loss dielectric material specimens of polypropylene
is demonstrated experimentally. The method was validated by excellent agreement
with a free-space focused-beam system measurement of a polypropylene sheet.
This technique provides the material measurement community with the ability to
accurately extract material properties of low-loss material specimen over the
entire X-band range. This technique could easily be extended to other frequency
bands.


title: Constraints on dark-matter properties from large-scale structure

abstract:
  We use large-scale cosmological observations to place constraints on the
dark-matter pressure, sound speed and viscosity, and infer a limit on the mass
of warm-dark-matter particles. Measurements of the cosmic microwave background
(CMB) anisotropies constrain the equation of state and sound speed of the dark
matter at last scattering at the per mille level. Since the redshifting of
collisionless particles universally implies that these quantities scale like
$a^{-2}$ absent shell crossing, we infer that today $w_{\rm (DM)}< 10^{-10.0}$,
$c_{\rm s,(DM)}^2 < 10^{-10.7}$ and $c_{\rm vis, (DM)}^{2} < 10^{-10.3}$ at the
$99\%$ confidence level. This very general bound can be translated to
model-dependent constraints on dark-matter models: for warm dark matter these
constraints imply $m> 70$ eV, assuming it decoupled while relativistic around
the same time as the neutrinos; for a cold relic, we show that $m>100$ eV. We
separately constrain the properties of the DM fluid on linear scales at late
times, and find upper bounds $c_{\rm s, (DM)}^2<10^{-5.9}$, $c_{\rm vis,
(DM)}^{2} < 10^{-5.7}$, with no detection of non-dust properties for the DM.


title: The Geology of Pluto and Charon Through the Eyes of New Horizons

abstract:
  NASA's New Horizons spacecraft has revealed the complex geology of Pluto and
Charon. Pluto's encounter hemisphere shows ongoing surface geological activity
centered on a vast basin containing a thick layer of volatile ices that appears
to be involved in convection and advection, with a crater retention age no
greater than $\approx$10 Ma. Surrounding terrains show active glacial flow,
apparent transport and rotation of large buoyant water-ice crustal blocks, and
pitting, likely by sublimation erosion and/or collapse. More enigmatic features
include tall mounds with central depressions that are conceivably cryovolcanic,
and ridges with complex bladed textures. Pluto also has ancient cratered
terrains up to ~4 Ga old that are extensionally fractured and extensively
mantled and perhaps eroded by glacial or other processes. Charon does not
appear to be currently active, but experienced major extensional tectonism and
resurfacing (probably cryovolcanic) nearly 4 billion years ago. Impact crater
populations on Pluto and Charon are not consistent with the steepest proposed
impactor size-frequency distributions proposed for the Kuiper belt.


title:
A large deviations analysis of certain qualitative properties of
  parallel tempering and infinite swapping algorithms

abstract:
  Parallel tempering, or replica exchange, is a popular method for simulating
complex systems. The idea is to run parallel simulations at different
temperatures, and at a given swap rate exchange configurations between the
parallel simulations. From the perspective of large deviations it is optimal to
let the swap rate tend to infinity and it is possible to construct a
corresponding simulation scheme, known as infinite swapping. In this paper we
propose a novel use of large deviations for empirical measures for a more
detailed analysis of the infinite swapping limit in the setting of continuous
time jump Markov processes. Using the large deviations rate function and
associated stochastic control problems we consider a diagnostic based on
temperature assignments, which can be easily computed during a simulation. We
show that the convergence of this diagnostic to its a priori known limit is a
necessary condition for the convergence of infinite swapping. The rate function
is also used to investigate the impact of asymmetries in the underlying
potential landscape, and where in the state space poor sampling is most likely
to occur.


title:
The Impact of New Polarization Data from Bonn, Mainz and Jefferson
  Laboratory on $\gamma p \to \pi N$ Multipoles

abstract:
  New data on pion-photoproduction off the proton have been included in the
partial wave analyses Bonn-Gatchina and SAID and in the dynamical
coupled-channel approach J\"ulich-Bonn. All reproduce the recent new data well:
the double polarization data for E, G, H, P and T in $\gamma p \to \pi^0 p$
from ELSA, the beam asymmetry $\Sigma$ for $\gamma p \to \pi^0 p$ and $\pi^+ n$
from Jefferson Laboratory, and the precise new differential cross section and
beam asymmetry data $\Sigma$ for $\gamma p \to \pi^0 p$ from MAMI. The new fit
results for the multipoles are compared with predictions not taking into
account the new data. The mutual agreement is improved considerably but still
far from being perfect.


title: Thermodynamics of spinning AdS4 black holes in gauged supergravity

abstract:
  In this paper we study the thermodynamics of rotating black hole solutions
arising from four-dimensional gauged N=2 supergravity. We analyze two different
supergravity models, characterized by prepotentials $F = -i X^0 X^1$ and $F=
-2i \sqrt{X^0 (X^1)^3}$. The black hole configurations are supported by
electromagnetic charges and scalar fields with different kinds of boundary
conditions. We perform our analysis in the canonical ensemble, where we find a
first order phase transition for a suitable range of charges and angular
momentum. We perform the thermodynamic stability check on the configurations.
Using the holographic dictionary we interpret the phase transition in terms of
expectation values of operators in the dual field theory, which pertains to the
class of ABJM theories living on a rotating Einstein universe. We extend the
analysis to dyonic configurations as well. Lastly, we show the computation of
the on-shell action and mass via holographic renormalization techniques.


title:
Dynamical model reduction method for solving parameter-dependent
  dynamical systems

abstract:
  We propose a projection-based model order reduction method for the solution
of parameter-dependent dynamical systems. The proposed method relies on the
construction of time-dependent reduced spaces generated from evaluations of the
solution of the full-order model at some selected parameters values. The
approximation obtained by Galerkin projection is the solution of a reduced
dynamical system with a modified flux which takes into account the time
dependency of the reduced spaces. An a posteriori error estimate is derived and
a greedy algorithm using this error estimate is proposed for the adaptive
selection of parameters values. The resulting method can be interpreted as a
dynamical low-rank approximation method with a subspace point of view and a
uniform control of the error over the parameter set.


title:
Embeddings of Riemannian Manifolds with Finite Eigenvector Fields of
  Connection Laplacian

abstract:
  We study the problem asking if one can embed manifolds into finite
dimensional Euclidean spaces by taking finite number of eigenvector fields of
the connection Laplacian. This problem is essential for the dimension reduction
problem in massive data analysis. Singer-Wu proposed the vector diffusion map
which embeds manifolds into the Hilbert space $l^2$ using eigenvectors of
connection Laplacian. In this paper, we provide a positive answer to the
problem. Specifically, we use eigenvector fields to construct local coordinate
charts with low distortion, and show that the distortion constants depend only
on geometric properties of manifolds with metrics in the little H\"{o}lder
space $c^{2,\alpha}$. Next, we use the coordinate charts to embed the entire
manifold into a finite dimensional Euclidean space. The proof of the results
relies on solving the elliptic system and provide estimates for eigenvector
fields and the heat kernel and their gradients. We also provide approximation
results for eigenvector field under the $c^{2,\alpha}$ perturbation.


title:
Model-independent evidence for $J/\psi p$ contributions to
  $\Lambda_b^0\to J/\psi p K^-$ decays

abstract:
  The data sample of $\Lambda_b^0\to J/\psi p K^-$ decays acquired with the
LHCb detector from 7 and 8~TeV $pp$ collisions, corresponding to an integrated
luminosity of 3 fb$^{-1}$, is inspected for the presence of $J/\psi p$ or
$J/\psi K^-$ contributions with minimal assumptions about $K^- p$
contributions. It is demonstrated at more than 9 standard deviations that
$\Lambda_b^0\to J/\psi p K^-$ decays cannot be described with $K^- p$
contributions alone, and that $J/\psi p$ contributions play a dominant role in
this incompatibility. These model-independent results support the previously
obtained model-dependent evidence for $P_c^+\to J/\psi p$ charmonium-pentaquark
states in the same data sample.


title: Universality of random matrices with correlated entries

abstract:
  We consider an $N$ by $N$ real symmetric random matrix $X=(x_{ij})$ where
$\mathbb{E}x_{ij}x_{kl}=\xi_{ijkl}$. Under the assumption that $(\xi_{ijkl})$
is the discretization of a piecewise Lipschitz function and that the
correlation is short-ranged we prove that the empirical spectral measure of $X$
converges to a probability measure. The Stieltjes transform of the limiting
measure can be obtained by solving a functional equation. Under the slightly
stronger assumption that $(x_{ij})$ has a strictly positive definite covariance
matrix, we prove a local law for the empirical measure down to the optimal
scale $\text{Im} z \gtrsim N^{-1}$. The local law implies delocalization of
eigenvectors. As another consequence we prove that the eigenvalue statistics in
the bulk agrees with that of the GOE.


title: Long wave limit for Schrodinger maps

abstract:
  We study long wave limits for general Schrodinger maps systems into Kahler
manifolds with a constraining potential vanishing on a Lagrangian submanifold.
We obtain KdV type systems set on the tangent space of the submanifold. Our
general theory is applied to study the long wave limit of the Gross-Pitaevskii
equation, and of the Landau-Lifshitz systems for ferromagnetic and
antiferromagnetic chains.


title: A Matrix Model for WZW

abstract:
  We study a U(N) gauged matrix quantum mechanics which, in the large N limit,
is closely related to the chiral WZW conformal field theory. This manifests
itself in two ways. First, we construct the left-moving Kac-Moody algebra from
matrix degrees of freedom. Secondly, we compute the partition function of the
matrix model in terms of Schur and Kostka polynomials and show that, in the
large $N$ limit, it coincides with the partition function of the WZW model.
This same matrix model was recently shown to describe non-Abelian quantum Hall
states and the relationship to the WZW model can be understood in this
framework.


title: Phenomenology of current-induced skyrmion motion in antiferromagnets

abstract:
  We study current-driven skyrmion motion in uniaxial thin film
antiferromagnets in the presence of the Dzyaloshinskii-Moriya interactions and
in an external magnetic field. We phenomenologically include relaxation and
current-induced torques due to both spin-orbit coupling and spatially
inhomogeneous magnetic textures in the equation for the N\'eel vector of the
antiferromagnet. Using the collective coordinate approach we apply the theory
to a two-dimensional antiferromagnetic skyrmion and estimate the skyrmion
velocity under an applied DC electric current.


title:
Insulating and metallic spin glass in
  K$_{x}$Fe$_{2-\delta-y}$Ni$_{y}$Se$_{2}$ (0.06 $\leq$ $y$ $\leq$ 1.44) single
  crystals

abstract:
  We report electron doping effects by Ni in
K$_{x}$Fe$_{2-\delta-y}$Ni$_{y}$Se$_{2}$ (0.06 $\leq$ $y$ $\leq$ 1.44) single
crystal alloys. A rich ground state phase diagram is observed. Small amount of
Ni ($\sim$ 4\%) suppressed superconductivity below 1.8 K, inducing insulating
spin glass magnetic ground state for higher Ni content. With further Ni
substitution, metallic resistivity is restored. For high Ni concentration in
the lattice the unit cell symmetry is high symmetry $I4/mmm$ with no phase
separation whereas both $I4/m + I4/mmm$ space groups were detected in the phase
separated crystals when concentration of Ni $<$ Fe. The absence of
superconductivity coincides with the absence of crystalline Fe vacancy order.


title: ALMA suggests outflows in z~5.5 galaxies

abstract:
  We present the first attempt to detect outflows from galaxies approaching the
Epoch of Reionization (EoR) using a sample of 9 star-forming ($\rm SFR=31\pm
20~M_{\odot}~yr^{-1}$) $z\sim 5.5$ galaxies for which the [CII]158$\mu$m line
has been previously obtained with ALMA. We first fit each line with a Gaussian
function and compute the residuals by subtracting the best fitting model from
the data. We combine the residuals of all sample galaxies and find that the
total signal is characterised by a flux excess of $\sim 0.5$ mJy extended over
$\sim 1000$ km~s$^{-1}$. Although we cannot exclude that part of this signal is
due to emission from faint satellite galaxies, we show that the most probable
explanation for the detected flux excess is the presence of broad wings in the
[CII] lines, signatures of starburst-driven outflows. We infer an average
outflow rate of $\rm \dot{M}=54\pm23~ M_{\odot}~yr^{-1}$, providing a loading
factor $\eta=\rm \dot{M}/SFR=1.7\pm1.3$ in agreement with observed local
starbursts. Our interpretation is consistent with outcomes from zoomed
hydro-simulations of {\it Dahlia}, a $z\sim 6$ galaxy ($\rm SFR\sim 100~\rm
M_{\odot}~yr^{-1}$) whose feedback-regulated star formation results into an
outflow rate $\rm \dot{M}\sim 30~ M_{\odot}~yr^{-1}$. The quality of the ALMA
data is not sufficient for a detailed analysis of the [CII] line profile in
individual galaxies. Nevertheless, our results suggest that starburst-driven
outflows are in place in the EoR and provide useful indications for future ALMA
campaigns. Deeper observations of the [CII] line in this sample are required to
better characterise feedback at high-$z$ and to understand the role of outflows
in shaping early galaxy formation.


title: Thermodynamics of Benford's First Digit Law

abstract:
  Iafrate, Miller, and Strauch [Equipartition and a Distribution for Numbers: A
Statistical Model for Benford's Law," arXiv:1503.08259] construct and test a
statistical model for partitioning a conserved quantity. One consequence of
their model is Benford's law. This Comment amplifies their work by exploring
its thermodynamic consequences.


title: A Dark Matter Signature for Condensed Neutrinos

abstract:
  We derive the signature for condensed neutrino objects (CNOs) as the primary
source of Dark Matter. Restricting our source data to minimize systematic
errors, we find that by just using weak lensing data and Sunyaev-Zel'dovich
data, that there may be a weak CNO signature.


title: Positive maps which are bijective on the set of rank projections

abstract:
  Extending Wigner's theorem we give a characterization of positive maps of
$B(H)$ into itself which map the set of rank k projections onto itself.


title:
The new eclipsing CV MASTER OTJ192328.22+612413.5 - a possible SW
  Sextantis Star

abstract:
  We present optical photometry and spectroscopy of the new eclipsing
Cataclysmic Variable MASTER OTJ192328.22+612413.5, discovered by the MASTER
team. We find the orbital period to be P=0.16764612(5) day /4.023507(1) hour.
The depth of the eclipse (2.9$\pm$0.1 mag) suggests that the system is nearly
edge on, and modeling of the system confirms the inclination to be between
81.3-83.6 degree. The brightness outside of eclipse varies between
observations, with a change of 1.6$\pm$0.1 mag. Spectroscopy reveals
double-peaked Balmer emission lines. By using spectral features matching a late
M-type companion, we bound the distance to be 750$\pm$250 pc, depending on the
companion spectral type. The source displays 2 mag brightness changes on
timescales of days. The amplitude of these changes, along with the spectrum at
the faint state, suggest the system is possibly a dwarf nova. The lack of any
high excitation HeII lines suggests this system is not magnetically dominated.
The light curve in both quiescence and outburst resembles that of Lanning 386,
implying MASTER OTJ192328.22+612413.5 is a possible cross between a dwarf nova
and a SW Sextantis star.


title: ALMA Survey of Lupus Protoplanetary Disks I: Dust and Gas Masses

abstract:
  We present the first high-resolution sub-mm survey of both dust and gas for a
large population of protoplanetary disks. Characterizing fundamental properties
of protoplanetary disks on a statistical level is critical to understanding how
disks evolve into the diverse exoplanet population. We use ALMA to survey 89
protoplanetary disks around stars with $M_{\ast}>0.1~M_{\odot}$ in the young
(1--3~Myr), nearby (150--200~pc) Lupus complex. Our observations cover the
890~$\mu$m continuum and the $^{13}$CO and C$^{18}$O 3--2 lines. We use the
sub-mm continuum to constrain $M_{\rm dust}$ to a few Martian masses
(0.2--0.4~$M_{\oplus}$) and the CO isotopologue lines to constrain $M_{\rm
gas}$ to roughly a Jupiter mass (assuming ISM-like $\rm {[CO]/[H_2]}$
abundance). Of 89 sources, we detect 62 in continuum, 36 in $^{13}$CO, and 11
in C$^{18}$O at $>3\sigma$ significance. Stacking individually undetected
sources limits their average dust mass to $\lesssim6$ Lunar masses
(0.03~$M_{\oplus}$), indicating rapid evolution once disk clearing begins. We
find a positive correlation between $M_{\rm dust}$ and $M_{\ast}$, and present
the first evidence for a positive correlation between $M_{\rm gas}$ and
$M_{\ast}$, which may explain the dependence of giant planet frequency on host
star mass. The mean dust mass in Lupus is 3$\times$ higher than in Upper Sco,
while the dust mass distributions in Lupus and Taurus are statistically
indistinguishable. Most detected disks have $M_{\rm gas}\lesssim1~M_{\rm Jup}$
and gas-to-dust ratios $<100$, assuming ISM-like $\rm {[CO]/[H_2]}$ abundance;
unless CO is very depleted, the inferred gas depletion indicates that planet
formation is well underway by a few Myr and may explain the unexpected
prevalence of super-Earths in the exoplanet population.


title:
First Connection between Cold Gas in Emission and Absorption: CO
  Emission from a Galaxy-Quasar Pair

abstract:
  We present the first detection of molecular emission from a galaxy selected
to be near a projected background quasar using the Atacama Large
Millimeter/submillimeter Array (ALMA). The ALMA detection of CO(1$-$0) emission
from the $z=0.101$ galaxy toward quasar PKS 0439-433 is coincident with its
stellar disk and yields a molecular gas mass of $M_{\rm mol} \approx 4.2 \times
10^9 M_\odot$ (for a Galactic CO-to-H$_2$ conversion factor), larger than the
upper limit on its atomic gas mass. We resolve the CO velocity field, obtaining
a rotational velocity of $134 \pm 11$ km s$^{-1}$, and a resultant dynamical
mass of $\geq 4 \times 10^{10} M_\odot$. Despite its high metallicity and large
molecular mass, the $z=0.101$ galaxy has a low star formation rate, implying a
large gas consumption timescale, larger than that typical of late-type
galaxies. Most of the molecular gas is hence likely to be in a diffuse extended
phase, rather than in dense molecular clouds. By combining the results of
emission and absorption studies, we find that the strongest molecular
absorption component toward the quasar cannot arise from the molecular disk,
but is likely to arise from diffuse gas in the galaxy's circumgalactic medium.
Our results emphasize the potential of combining molecular and stellar emission
line studies with optical absorption line studies to achieve a more complete
picture of the gas within and surrounding high-redshift galaxies.


title: Ultrahigh Energy Cosmic Rays: A Galactic Origin?

abstract:
  It is suggested that essentially all of the UHECRs we detect, including those
at the highest energy, originate in our Galaxy. It is shown that even if the
density of sources decreases with Galactic radius, then the anisotropy and
composition can be understood. Inward anisotropy, as recently reported by the
Auger collaboration can be understood as drift along the current sheet of
UHECRs originating outside the solar circle, as predicted in Kumar and Eichler
(2014), while those originating within the solar circle exit the Galaxy at high
latitudes.


title:
Low-radio-frequency eclipses of the redback pulsar J2215+5135 observed
  in the image plane with LOFAR

abstract:
  The eclipses of certain types of binary millisecond pulsars (i.e. `black
widows' and `redbacks') are often studied using high-time-resolution,
`beamformed' radio observations. However, they may also be detected in images
generated from interferometric data. As part of a larger imaging project to
characterize the variable and transient sky at radio frequencies <200 MHz, we
have blindly detected the redback system PSR J2215+5135 as a variable source of
interest with the Low-Frequency Array (LOFAR). Using observations with cadences
of 2 weeks - 6 months, we find preliminary evidence that the eclipse duration
is frequency dependent ($\propto \nu^{-0.4}$), such that the pulsar is eclipsed
for longer at lower frequencies, in broad agreement with beamformed studies of
other similar sources. Furthermore, the detection of the eclipses in imaging
data suggests an eclipsing medium that absorbs the pulsed emission, rather than
scattering it. Our study is also a demonstration of the prospects of finding
pulsars in wide-field imaging surveys with the current generation of
low-frequency radio telescopes.


title:
ALMA Imaging and Gravitational Lens Models of South Pole
  Telescope-Selected Dusty, Star-Forming Galaxies at High Redshifts

abstract:
  The South Pole Telescope has discovered one hundred gravitationally lensed,
high-redshift, dusty, star-forming galaxies (DSFGs). We present 0.5" resolution
870um Atacama Large Millimeter/submillimeter Array imaging of a sample of 47
DSFGs spanning z=1.9-5.7, and construct gravitational lens models of these
sources. Our visibility-based lens modeling incorporates several sources of
residual interferometric calibration uncertainty, allowing us to properly
account for noise in the observations. At least 70% of the sources are strongly
lensed by foreground galaxies (mu_870um > 2), with a median magnification
mu_870um = 6.3, extending to mu_870um > 30. We compare the intrinsic size
distribution of the strongly lensed sources to a similar number of unlensed
DSFGs and find no significant differences in spite of a bias between the
magnification and intrinsic source size. This may indicate that the true size
distribution of DSFGs is relatively narrow. We use the source sizes to
constrain the wavelength at which the dust optical depth is unity and find this
wavelength to be correlated with the dust temperature. This correlation leads
to discrepancies in dust mass estimates of a factor of 2 compared to estimates
using a single value for this wavelength. We investigate the relationship
between the [CII] line and the far-infrared luminosity and find that the same
correlation between the [CII]L_FIR ratio and Sigma_FIR found for low-redshift
star-forming galaxies applies to high-redshift galaxies and extends at least
two orders of magnitude higher in Sigma_FIR. This lends further credence to the
claim that the compactness of the IR-emitting region is the controlling
parameter in establishing the "[CII] deficit."


title: Tomography of Majorana Fermions with STM Tips

abstract:
  We investigate numerically the possibility to detect the spatial profile of
Majorana fermions (MFs) modeling STM tips that are made of either normal or
superconducting material. In both cases, we are able to resolve the
localization length and the oscillation period of the MF wavefunction. We show
that the tunneling between the substrate and the tip, necessary to get the
information on the wave function oscillations, has to be smaller in the case of
a superconducting STM. In the strong tunneling regime, the differential
conductance saturates making it more difficult to observe the exponential decay
of MFs. The temperature broadening of the profile is strongly suppressed in
case of the superconducting lead resulting, generally, in better resolution.


title:
A map of the large day-night temperature gradient of a super-Earth
  exoplanet

abstract:
  Over the past decade, observations of giant exoplanets (Jupiter-size) have
provided key insights into their atmospheres, but the properties of lower-mass
exoplanets (sub-Neptune) remain largely unconstrained because of the challenges
of observing small planets. Numerous efforts to observe the spectra of
super-Earths (exoplanets with masses of one to ten times that of Earth) have so
far revealed only featureless spectra. Here we report a longitudinal thermal
brightness map of the nearby transiting super-Earth 55 Cancri e revealing
highly asymmetric dayside thermal emission and a strong day-night temperature
contrast. Dedicated space-based monitoring of the planet in the infrared
revealed a modulation of the thermal flux as 55 Cancri e revolves around its
star in a tidally locked configuration. These observations reveal a hot spot
that is located 41 +- 12 degrees east of the substellar point (the point at
which incident light from the star is perpendicular to the surface of the
planet). From the orbital phase curve, we also constrain the nightside
brightness temperature of the planet to 1380 +- 400 kelvin and the temperature
of the warmest hemisphere (centred on the hot spot) to be about 1300 kelvin
hotter (2700 +- 270 kelvin) at a wavelength of 4.5 microns, which indicates
inefficient heat redistribution from the dayside to the nightside. Our
observations are consistent with either an optically thick atmosphere with heat
recirculation confined to the planetary dayside, or a planet devoid of
atmosphere with low-viscosity magma flows at the surface.


title:
Baryon Number, Lepton Number, and Operator Dimension in the Standard
  Model

abstract:
  We prove that for a given operator in the Standard Model (SM) with baryon
number B and lepton number L, that the operator's dimension is even (odd) if
(B-L)/2 is even (odd). Consequently, this establishes the veracity of
statements that were long observed or expected to be true, but not proven,
e.g., operators with B-L=0 are of even dimension, B-L must be an even number,
etc. These results remain true even if the SM is augmented by any number of
right-handed neutrinos with L=1.


title: The 2015 hard-state only outburst of GS 1354-64

abstract:
  Since its outburst in 1997 GS 135-64 stayed in quiescence. In June 2015
renewed activity of GS 1354-64 was observed. Based on our analysis of energy
spectra and timing properties obtained from Swift/XRT monitoring data we found
that GS 1354-64 stayed in the hard state during the entire outburst. Such a
hard state only (or "failed" outburst) has also been observed in 1997. In
addition, we analysed an XMM-Newton observation taken on August 6th. We
compared variability on long and short time scales using covariance ratio and
found that the ratio showed a decrease towards lower energies instead of the
increase that has been found in other black hole X-ray binaries. There are now
two sources (H 1743-322 and GS 1354-64) that do not show an increase towards
lower energies in their covariance ratio. Both sources have been observed
during "failed" outbursts and showed photon indices much harder than what is
usually observed in black hole X-ray binaries.


title: A Cautionary Tale of Mis-measured Tails from $q/g$ Bias

abstract:
  Jet substructure techniques such as subjet $p_T$-asymmetry, mass-drop, and
grooming have become powerful and widely used tools in experimental searches at
the LHC. While these tools provide much-desired handles to separate signal from
background, they can introduce unexpected mass scales into the analysis. These
scales may be misinterpreted as excesses if these are not correctly
incorporated into background modeling. As an example, we study the ATLAS
hadronic di-$W/Z$ resonance search. There, we find that the substructure
analysis -- in particular the combination of a subjet asymmetry cut with the
requirement on the number of tracks within a jet -- induces a mass scale where
the dominant partonic subprocess in the background changes from $pp \to g \!+\!
q/\bar q$ to $pp \to q\bar{q}$. In light of this scale, modeling the QCD
background using a simple smooth function with monotonically decreasing slope
appears insufficient.


title:
Evidence for Cluster to Cluster Variations in Low-Mass Stellar
  Rotational Evolution

abstract:
  A concordance model for angular momentum evolution has been developed by
multiple investigators. This approach postulates that star forming regions and
clusters are an evolutionary sequence which can be modeled with assumptions
about the coupling between protostars and accretion disks, angular momentum
loss from magnetized winds that saturates in a mass-dependent fashion at high
rotation rates, and core-envelope decoupling for solar analogs. We test this
approach by combining established data with the large h Per dataset from the
MONITOR project and new low-mass Pleiades data. We confirm prior results that
young low-mass stars can be used to test star-disk coupling and angular
momentum loss independent of the treatment of internal angular momentum
transport. For slow rotators, we confirm the need for star-disk interactions to
evolve the ONC to older systems, using h Per (age 13~Myr) as our natural
post-disk case. Further interactions are not required to evolve slow rotators
from h Per to older systems, implying no justification for extremely long-lived
disks as an alternative to core-envelope decoupling. However, our wind models
cannot evolve rapid rotators from h Per to older systems consistently; this
appears to be a general problem for any wind model that becomes ineffective in
low-mass young stars. We outline two possible solutions: either there is cosmic
variance in the distribution of stellar rotation rates in different clusters or
there are substantially enhanced torques in low-mass rapid rotators. We favor
the former explanation and discuss observational tests that could be used to
distinguish them. If the distribution of initial conditions depends on
environment, models which test parameters by assuming a universal underlying
distribution of initial conditions will need to be re-evaluated.


title:
The peculiar Type Ia supernova iPTF14atg: Chandrasekhar-mass explosion
  or violent merger?

abstract:
  iPTF14atg, a subluminous peculiar Type Ia supernova (SN Ia) similar to SN
2002es, is the first SN Ia for which a strong UV flash was observed in the
early-time light curves. This has been interpreted as evidence for a
single-degenerate (SD) progenitor system where such a signal is expected from
interactions between the SN ejecta and the non-degenerate companion star. Here,
we compare synthetic observables of multi-dimensional state-of-the-art
explosion models for different progenitor scenarios to the light curves and
spectra of iPTF14atg. From our models, we have difficulties explaining the
spectral evolution of iPTF14atg within the SD progenitor channel. In contrast,
we find that a violent merger of two carbon-oxygen white dwarfs with 0.9 and
0.76 solar masses, respectively, provides an excellent match to the spectral
evolution of iPTF14atg from 10d before to several weeks after maximum light.
Our merger model does not naturally explain the initial UV flash of iPTF14atg.
We discuss several possibilities like interactions of the SN ejecta with the
circum-stellar medium and surface radioactivity from a He ignited merger that
may be able to account for the early UV emission in violent merger models.


title:
Delayed entanglement echo for individual control of a large number of
  nuclear spins

abstract:
  Methods for achieving quantum control and detection of individual nuclear
spins by single electrons of solid-state defects play a central role for
quantum information processing and nano-scale nuclear magnetic resonance (NMR).
However, with standard techniques, no more than 8 nuclear spins have been
resolved. Here we develop a method that improves significantly the ability to
spectrally resolve nuclear spins and demonstrate its capabilities with detailed
numerical simulations by using a nitrogen-vacancy (NV) centre as model system.
Based on delayed entanglement control, a technique combining microwave and
radio-frequency (rf) fields, nuclei with resonances in a broad frequency band
can be unambiguously and individually addressed by the sensor electron.
Additionally the spectral resolution can extend beyond the electron spin
relaxation time by using a long-lived qubit memory. Our method greatly
increases the number of useful register qubits accessible to a defect centre
and improves the signals of nano-scale NMR.


title:
Non-equilibrium properties of trapped ions under sudden application of a
  laser

abstract:
  Coherent quantum-state manipulation of trapped ions using classical laser
fields is a trademark of modern quantum technologies. In this work, we study
aspects of work statistics and irreversibility in a single trapped ion due to
sudden interaction with the impinging laser. This is clearly an
out-of-equilibrium process where work is performed through illumination of an
ion by the laser. Starting with the explicit evaluation of the first moments of
the work distribution, we proceed to a careful analysis of irreversibility as
quantified by the nonequilibrium lag. The treatment employed here is not
restricted to the Lamb-Dicke limit, which allows us to investigate the
interplay between nonlinearities and irreversibility. We show that in these
multiquantum or sideband regimes, variation of the Lamb-Dicke parameter causes
a non-monotonic behavior of the irreversibility indicator. Counterintuitively,
we find a working point where nonlinearity helps reversibility, making the
sudden quench of the Hamiltonian closer to what would have been obtained
quasistatically and isothermally.


title:
The Solar Twin Planet Search III. The [Y/Mg] clock: estimating stellar
  ages of solar-type stars

abstract:
  Solar twins are stars with similar stellar (surface) parameters to the Sun
that can have a wide range of ages. This provide an opportunity to analyze the
variation of their chemical abundances with age. Nissen (2015) recently
suggested that the abundances of the s-process element Y and the
$\alpha$-element Mg could be used to estimate stellar ages. This paper aims to
determine with high precision the Y, Mg, and Fe abundances for a sample of 88
solar twins that span a broad age range ($0.3-10.0$\,Gyr) and investigate their
use for estimating ages. We obtained high-quality Magellan Inamori Kyocera
Echelle (MIKE) spectra and determined Y and Mg abundances using equivalent
widths and a line-by-line differential method within a 1D LTE framework.
Stellar parameters and iron abundances were measured in Paper I of this series
for all stars, but a few (three) required a small revision. The [Y/Mg] ratio
shows a strong correlation with age. It has a slope of -0.041$\pm$0.001 dex/Gyr
and a significance of 41 $\sigma$. This is in excellent agreement with the
relation first proposed by Nissen (2015). We found some outliers that turned
out to be binaries where mass transfer may have enhanced the yttrium abundance.
Given a precise measurement of [Y/Mg] with typical error of 0.02 dex in solar
twins, our formula can be used to determine a stellar age with $\sim$0.8 Gyr
precision in the 0 to 10 Gyr range.


title: Data-driven priors and their posterior concentration rates

abstract:
  In high-dimensional problems, choosing a prior distribution such that the
corresponding posterior has desirable practical and theoretical properties can
be challenging. This begs the question: can the data be used to help choose a
good prior? In this paper, we develop a general strategy for constructing a
data-driven or empirical prior and sufficient conditions for the corresponding
posterior distribution to achieve a certain concentration rate. The idea is
that the prior should put sufficient mass on parameter values for which the
likelihood is large. An interesting byproduct of this data-driven centering is
that the asymptotic properties of the posterior are less sensitive to the prior
shape which, in turn, allows users to work with priors of computationally
convenient forms while maintaining the desired rates. General results on both
adaptive and non-adaptive rates based on empirical priors are presented, along
with illustrations in density estimation, nonparametric regression, and
high-dimensional structured normal models.


title: New Neutron-Capture Measurements in 23 Open Clusters. I. The R-Process

abstract:
  Neutron-capture elements, those with Z > 35, are the least well-understood in
terms of nucleosynthesis and formation environments. The rapid neutron-capture,
or r-process, elements are formed in the environments and/or remnants of
massive stars, while the slow neutron-capture, or s-process, elements are
primarily formed in low-mass AGB stars. These elements can provide much
information about Galactic star formation and enrichment, but observational
data is limited. We have assembled a sample of 68 stars in 23 open clusters
that we use to probe abundance trends for six neutron-capture elements (Eu, Gd,
Dy, Mo, Pr, and Nd) with cluster age and location in the disk of the Galaxy. In
order to keep our analysis as homogenous as possible, we use an automated
synthesis fitting program, which also enables us to measure multiple (3-10)
lines for each element. We find that the pure r-process elements (Eu, Gd, and
Dy) have positive trends with increasing cluster age, while the mixed r- and s-
process elements (Mo, Pr, and Nd) have insignificant trends consistent with
zero. Pr, Nd, Eu, Gd, and Dy have similar, slight (though mostly statistically
significant) gradients of ~0.04 dex/kpc. The mixed elements also appear to have
nonlinear relationships with Galactocentric radius.


title:
Spreading of correlations in exactly-solvable quantum models with
  long-range interactions in arbitrary dimensions

abstract:
  We study the out-of-equilibrium dynamics induced by quantum quenches in
quadratic Hamiltonians featuring both short- and long-range interactions. The
spreading of correlations in the presence of algebraic decaying interactions,
$1/R^\alpha$, is studied for lattice Bose models in arbitrary dimension $D$.
These models are exactly solvable and provide useful insight in the universal
description of more complex systems as well as comparisons to the known
universal upper bounds for the spreading of correlations. Using analytical
calculations of the dominant terms and full numerical integration of all
quasi-particle contributions, we identify three distinct dynamical regimes. For
strong decay of nteractions, $\alpha>D+1$, we find a causal regime,
qualitatively similar to what previously found for short-range interactions.
This regime is characterized by ballistic (linear cone) spreading of the
correlations with a cone velocity equal to twice the maximum group velocity of
the quasi-particles. For weak decay of interactions, $\alpha<D$, we find
instantaneous activation of correlations at arbitrary distance. This signals
the breaking of causality, which can be associated with the divergence of the
quasi-particle energy spectrum. Finite-size scaling of the activation time
precisely confirms this interpretation. For intermediate decay of interactions,
$D<\alpha<D+1$, we find a sub-ballistic, algebraic (bent cone) spreading and
determine the corresponding exponent as a function of $\alpha$. These outcomes
generalize existing results for one-dimensional systems to arbitrary dimension.
We precisely relate the three regimes to the first- and second-order
divergences of the quasi-particle energy spectrum for any dimension.


title:
On Removing Interloper Contamination from Intensity Mapping Power
  Spectrum Measurements

abstract:
  Line intensity mapping experiments seek to trace large scale structure by
measuring the spatial fluctuations in the combined emission, in some convenient
spectral line, from individually unresolved galaxies. An important systematic
concern for these surveys is line confusion from foreground or background
galaxies emitting in other lines that happen to lie at the same observed
frequency as the "target" emission line of interest. We develop an approach to
separate this "interloper" emission at the power spectrum level. If one adopts
the redshift of the target emission line in mapping from observed frequency and
angle on the sky to co-moving units, the interloper emission is mapped to the
wrong co-moving coordinates. Since the mapping is different in the line of
sight and transverse directions, the interloper contribution to the power
spectrum becomes anisotropic, especially if the interloper and target emission
are at widely separated redshifts. This distortion is analogous to the
Alcock-Paczynski test, but here the warping arises from assuming the wrong
redshift rather than an incorrect cosmological model. We apply this to the case
of a hypothetical [CII] emission survey at z~7 and find that the distinctive
interloper anisotropy can, in principle, be used to separate strong foreground
CO emission fluctuations. In our models, however, a significantly more
sensitive instrument than currently planned is required, although there are
large uncertainties in forecasting the high redshift [CII] emission signal.
With upcoming surveys, it may nevertheless be useful to apply this approach
after first masking pixels suspected of containing strong interloper
contamination.