title:
Gravitational scattering, post-Minkowskian approximation and Effective
  One-Body theory

abstract:
  A novel approach to the Effective One-Body description of gravitationally
interacting two-body systems is introduced. This approach is based on the
post-Minkowskian approximation scheme (perturbation theory in G, without
assuming small velocities), and employs a new dictionary focussing on the
functional dependence of the scattering angle on the total energy and the total
angular momentum of the system. Using this approach, we prove to all orders in
v/c two results that were previously known to hold only to a limited
post-Newtonian accuracy: (i) the relativistic gravitational dynamics of a
two-body system is equivalent, at first post-Minkowskian order, to the
relativistic dynamics of an effective test particle moving in a Schwarzschild
metric; and (ii) this equivalence requires the existence of an exactly
quadratic map between the real (relativistic) two-body energy and the
(relativistic) energy of the effective particle. The same energy map is also
shown to apply to the effective one-body description of two masses interacting
via tensor-scalar gravity.


title:
HD 240121 - an ACV variable showing anti-phase variations of the B and V
  light curves

abstract:
  The variability of HD 240121 = BD+59 2602 was first suspected by S\"arg &
Wramdemark (1970) and later confirmed by Gr\"obel (1992a,b). Because of the
observed anti-phase variations of the B and V light curves, the latter author
tentatively suggested an ACV type. Apart from its inclusion in the catalog of
New Suspected Variables (NSV 25977), no further investigations of the star have
been published. HD 240121 was included into our target list of ACV candidates
and investigated in order to determine the reason for the observed brightness
variations. All available information on HD 240121 were collected via an
exhaustive data mining procedure. Data from Gr\"obel (1992a,b) were re-analysed
and photometric observations from the NSVS and Hipparcos archives were procured
and investigated. Line-of-sight reddening and stellar parameters were
calculated from archival photometric data. HD 240121 is a young, late B-type
CP2 star of the silicon subgroup. The observed period, amplitude of light
variations and variability pattern (anti-phase variations) are typical of ACV
variables. The occurrence of anti-phase variations of the B and V light curves
is rarely observed and points to the existence of a null wavelength in the
visual spectrum. We therefore strongly encourage further multi-colour
photometric observations of this star.


title:
Spinning test-body orbiting around Schwarzschild black hole: circular
  dynamics and gravitational-wave fluxes

abstract:
  We consider a spinning test-body in circular motion around a nonrotating
black hole and analyze different prescriptions for the body's dynamics. We
compare, for the first time, the Mathisson-Papapetrou formalism under the
Tulczyjew spin-supplementary-condition (SSC), the Pirani SSC and the
Ohashi-Kyrian-Semerak SSC, and the spinning particle limit of the
effective-one-body Hamiltonian of [Phys.~Rev.~D.90,~044018(2014)]. We analyze
the four different dynamics in terms of the ISCO shifts and in terms of the
coordinate invariant binding energies, separating higher-order spin
contributions from spin-orbit contributions. The asymptotic gravitational wave
fluxes produced by the spinning body are computed by solving the inhomogeneous
$(2+1)D$ Teukolsky equation and contrasted for the different cases. For small
orbital frequencies $\Omega$, all the prescriptions reduce to the same dynamics
and the same radiation fluxes. For large frequencies, ${x \equiv (M
\Omega)^{2/3} >0.1 }$, where $M$ is the black hole mass, and especially for
positive spins (aligned with orbital angular momentum) a significant
disagreement between the different dynamics is observed. The ISCO shifts can
differ up to a factor two for large positive spins; for the
Ohashi-Kyrian-Semerak and the Pirani SSC the ISCO diverges around dimensionless
spins $\sim0.52$ and $\sim0.94$ respectively. In the spin-orbit part of the
energetics the deviation from the Hamiltonian dynamics is largest for the
Ohashi-Kyrian-Semerak SSC; it exceeds $10\%$ for $x>0.17$. The Tulczyjew and
the Pirani SSCs behave compatible across almost the whole spin and frequency
range. Our results will have direct application in including spin effects to
effective-one-body waveform models for circularized binaries in the
extreme-mass-ratio limit.


title: Theory of condensation of indirect excitons in a trap

abstract:
  We present theoretical studies of condensation of indirect excitons in a
trap. Our model quantifies the effect of screening of the trap potential by
indirect excitons on exciton condensation. The theoretical studies are applied
to a system of indirect excitons in a GaAs/AlGaAs coupled quantum well
structure in a diamond-shaped electrostatic trap where exciton condensation was
studied in earlier experiments. The estimated condensation temperature of the
indirect excitons in the trap reaches hundreds of milliKelvin.


title: Lorentzian manifolds with a conformal action of SL(2,R)

abstract:
  We consider conformal actions of simple Lie groups on compact Lorentzian
manifolds. Mainly motivated by the Lorentzian version of a conjecture of
Lichnerowicz, we establish the alternative: Either the group acts isometrically
for some metric in the conformal class, or the manifold is conformally flat -
that is, everywhere locally conformally diffeomorphic to Minkowski space-time.
When the group is non-compact and not locally isomorphic to SO(1,n), n>1, we
derive global conclusions, extending a theorem of Frances and Zeghib to some
simple Lie groups of real-rank 1. This result is also a first step towards a
classification of the conformal groups of compact Lorentz manifolds, analogous
to a classification of their isometry groups due to Adams, Stuck and,
independently, Zeghib at the end of the 1990's.


title:
Non-Markovian dynamics of a superconducting qubit in an open multimode
  resonator

abstract:
  We study the dynamics of a transmon qubit that is capacitively coupled to an
open multimode superconducting resonator. Our effective equations are derived
by eliminating resonator degrees of freedom while encoding their effect in the
Green's function of the electromagnetic background. We account for the
dissipation of the resonator exactly by employing a spectral representation for
the Green's function in terms of a set of non-Hermitian modes and show that it
is possible to derive effective Heisenberg-Langevin equations without resorting
to the rotating wave, two level or Markov approximations. A well-behaved time
domain perturbation theory is derived to systematically account for the
nonlinearity of the transmon. We apply this method to the problem of
spontaneous emission, capturing accurately the non-Markovian features of the
qubit dynamics, valid for any qubit-resonator coupling strength.


title:
A Network Object Method to Uncover Hidden Disorder-Related Brain
  Connectome

abstract:
  Neuropsychiatric disorders impact functional connectivity of the brain at the
network level. The identification and statistical testing of disorder-related
networks remains challenging. We propose novel methods to streamline the
detection and testing of the hidden, disorder-related connectivity patterns as
network-objects. We define an abnormal connectome subnetwork as a
network-object that includes three classes: nodes of brain areas, edges
representing brain connectomic features, and an organized graph topology formed
by these nodes and edges. Comparing to the conventional statistical methods,
the proposed approach simultaneously reduces false positive and negative
discovery rates by letting edges borrow strengths precisely with the guidance
of graph topological information, which effectively improves the
reproducibility of findings across brain connectome studies. The network-object
analyses may provide insights into how brain connectome is systematically
impaired by brain illnesses.


title:
Autonomous driving challenge: To Infer the property of a dynamic object
  based on its motion pattern using recurrent neural network

abstract:
  In autonomous driving applications a critical challenge is to identify action
to take to avoid an obstacle on collision course. For example, when a heavy
object is suddenly encountered it is critical to stop the vehicle or change the
lane even if it causes other traffic disruptions. However,there are situations
when it is preferable to collide with the object rather than take an action
that would result in a much more serious accident than collision with the
object. For example, a heavy object which falls from a truck should be avoided
whereas a bouncing ball or a soft target such as a foam box need not be.We
present a novel method to discriminate between the motion characteristics of
these types of objects based on their physical properties such as bounciness,
elasticity, etc.In this preliminary work, we use recurrent neural net-work with
LSTM cells to train a classifier to classify objects based on their motion
trajectories. We test the algorithm on synthetic data, and, as a proof of
concept, demonstrate its effectiveness on a limited set of real-world data.


title: Ancient eruptions of Eta Carinae: A tale written in proper motions

abstract:
  We analyze eight epochs of Hubble Space Telescope H$\alpha$+[N II] imaging of
Eta Carinae's outer ejecta. Proper motions of nearly 800 knots reveal that the
detected ejecta are divided into three apparent age groups, dating to around
1250 A.D., to around 1550 A.D., and to during or shortly before the Great
Eruption of the 1840s. Ejecta from these groups reside in different locations
and provide a firm constraint that Eta Car experienced multiple major eruptions
prior to the 19th century. The 1250 and 1550 events did not share the same
axisymmetry as the Homunculus; the 1250 event was particularly asymmetric, even
one-sided. In addition, the ejecta in the S ridge, which have been associated
with the Great Eruption, appear to predate the ejection of the Homunculus by
several decades. We detect essentially ballistic expansion across multiple
epochs. We find no evidence for large-scale deceleration of the observed knots
that could power the soft X-ray shell by plowing into surrounding material,
suggesting that the observed X-rays arise instead from fast, rarefied ejecta
from the 1840s overtaking the older dense knots. Early deceleration and
subsequent coasting cannot explain the origin of the older outer
ejecta---significant episodic mass loss prior to the 19th century is required.
The timescale and geometry of the past eruptions provide important constraints
for any theoretical physical mechanisms driving Eta Car's behavior.
Non-repeating mechanisms such as the merger of a close binary in a triple
system would require additional complexities to explain the observations.


title: Towards Quantum Turbulence in Cold Atomic Fermionic Superfluids

abstract:
  Fermionic superfluids provide a new realization of quantum turbulence,
accessible to both experiment and theory, yet relevant to phenomena from both
cold atoms to nuclear astrophysics. In particular, the strongly interacting
Fermi gas realized in cold-atom experiments is closely related to dilute
neutron matter in neutron star crusts. Unlike the liquid superfluids 4He
(bosons) and 3He (fermions) where quantum turbulence has been studied in the
laboratory, superfluid Fermi gases stand apart for a number of reasons. They
admit a reliable theoretical description based on a DFT called the TDSLDA that
describes both static and dynamic phenomena. Cold atom experiments demonstrate
exquisite control over particle number, spin polarization, density,
temperature, and interaction strength. Topological defects such as domain walls
and quantized vortices, which lie at the heart of quantum turbulence, can be
created and manipulated with time-dependent external potentials, and agree with
the time-dependent theoretical techniques. While similar experimental and
theoretical control exists for weakly interacting Bose gases, the unitary Fermi
gas is strongly interacting. The resulting vortex line density is extremely
high, and quantum turbulence may thus be realized in small systems where
classical turbulence is suppressed. Fermi gases also permit the study of exotic
superfluid phenomena such as a 3D LOFF supersolid, and a finite temperature
pseudo-gap in the regime of classical turbulence. The dynamics associated with
these phenomena has only started to be explored. Finally, superfluid mixtures
have recently been realized, providing experimental access to phenomena like
Andreev-Bashkin entrainment. Superfluid Fermi gases thus provide a rich forum
for addressing phenomena related to quantum turbulence with applications
ranging from terrestrial superfluidity to astrophysical dynamics in neutron
stars.


title: Inflation from Nilpotent K\"ahler Corrections

abstract:
  We develop a new class of supergravity cosmological models where inflation is
induced by terms in the K\"ahler potential which mix a nilpotent superfield $S$
with a chiral sector $\Phi$. As the new terms are non-(anti)holomorphic, and
hence cannot be removed by a K\"ahler transformation, these models are
intrinsically K\"ahler potential driven. Such terms could arise for example due
to a backreaction of an anti-D3 brane on the string theory bulk geometry. We
show that this mechanism is very general and allows for a unified description
of inflation and dark energy, with controllable SUSY breaking at the vacuum.
When the internal geometry of the bulk field is hyperbolic, we prove that small
perturbative K\"ahler corrections naturally lead to $\alpha$-attractor
behaviour, with inflationary predictions in excellent agreement with the latest
Planck data


title: State Estimation for Piecewise Affine State-Space Models

abstract:
  We propose a filter for piecewise affine state-space (PWASS) models. In each
filtering recursion, the true filtering posterior distribution is a mixture of
truncated normal distributions. The proposed filter approximates the mixture
with a single normal distribution via moment matching. The proposed algorithm
is compared with the extended Kalman filter (EKF) in a numerical simulation
where the proposed method obtains, on average, better root mean square error
(RMSE) than the EKF.


title:
Rigidity of Free Boundary Surfaces in Compact 3-Manifolds with Strictly
  Convex Boundary

abstract:
  In this paper we obtain an analogue of Toponogov theorem in dimension 3 for
compact manifolds $M^3$ with nonnegative Ricci curvature and strictly convex
boundary $\partial M$. Here we obtain a sharp upper bound for the length
$L(\partial\Sigma)$ of the boundary $\partial\Sigma$ of a free boundary minimal
surface $\Sigma^2$ in $M^3$ in terms of the genus of $\Sigma$ and the number of
connected components of $\partial\Sigma$, assuming $\Sigma$ has index one.
After, under a natural hypothesis on the geometry of $M$ along $\partial M$, we
prove that if $L(\partial\Sigma)$ saturates the respective upper bound, then
$M^3$ is isometric to the Euclidean 3-ball and $\Sigma^2$ is isometric to the
Euclidean disk. In particular, we get a sharp upper bound for the area of
$\Sigma$, when $M^3$ is a strictly convex body in $\mathbb R^3$, which is
saturated only on the Euclidean 3-balls (by the Euclidean disks). We also
consider similar results for stationary stable surfaces.


title: The Higgs boson at high $p_T$

abstract:
  We present a calculation of $H+j$ at NLO including the effect of a finite
top-mass. Where possible we include the complete dependence on $m_t$. This
includes the leading order amplitude, the infrared poles of the two-loop
amplitude and the real radiation amplitude. The remaining finite piece of the
virtual correction is considered in an asymptotic expansion in $m_t$, which is
accurate to $m_t^{-4}$. By successively including more $m_t$-exact pieces, the
dependence on the asymptotic series diminishes and we find convergent behavior
for $p_T^H>m_t$ for the first time. Our results justify rescaling by the
$m_t$-exact LO cross section to model top-mass effects in EFT results up to
$p_T$ of 250 to 300 GeV. We show that the error made by using the LO rescaling
becomes comparable to the NNLO scale uncertainty for such large energies. We
implement our results into the Monte Carlo code MCFM.


title: Ten Steps of EM Suffice for Mixtures of Two Gaussians

abstract:
  The Expectation-Maximization (EM) algorithm is a widely used method for
maximum likelihood estimation in models with latent variables. For estimating
mixtures of Gaussians, its iteration can be viewed as a soft version of the
k-means clustering algorithm. Despite its wide use and applications, there are
essentially no known convergence guarantees for this method. We provide global
convergence guarantees for mixtures of two Gaussians with known covariance
matrices. We show that the population version of EM, where the algorithm is
given access to infinitely many samples from the mixture, converges
geometrically to the correct mean vectors, and provide simple, closed-form
expressions for the convergence rate. As a simple illustration, we show that,
in one dimension, ten steps of the EM algorithm initialized at infinity result
in less than 1\% error estimation of the means. In the finite sample regime, we
show that, under a random initialization, $\tilde{O}(d/\epsilon^2)$ samples
suffice to compute the unknown vectors to within $\epsilon$ in Mahalanobis
distance, where $d$ is the dimension. In particular, the error rate of the EM
based estimator is $\tilde{O}\left(\sqrt{d \over n}\right)$ where $n$ is the
number of samples, which is optimal up to logarithmic factors.


title:
Harmonic oscillators at resonance, perturbed by a non-linear friction
  force

abstract:
  This note is an addendum to the results of P.O. Frederickson and A.C. Lazer
[1], and A.C. Lazer [4] on periodic oscillations, with linear part at
resonance. We show that a small modification of the argument in [4] provides a
more general result. It turns out that things are different for the
corresponding Dirichlet boundary value problem.


title: Quantum phase estimation using squeezed quasi-Bell states

abstract:
  In this paper we present a study of the quantum phase estimation problem
employing continuous-variable, entangled squeezed coherent (quasi-Bell) states
as probe states. We show that their inherent squeezing and entanglement
properties might bring advantages, increasing the precision of phase estimation
compared to protocols which employ other continuous variable states e.g.,
two-mode, entangled coherent states or single-mode, squeezed states. We also
analyze the phase estimation process considering: i) a linear (unitary)
perturbation, and ii) dissipation, and conclude that the use of entangled
squeezed coherent states as probe states may still be advantageous even under
non-ideal conditions.


title:
Precise Higgs mass calculations in (non-)minimal supersymmetry at both
  high and low scales

abstract:
  We present FlexibleEFTHiggs, a method for calculating the SM-like Higgs pole
mass in SUSY (and even non-SUSY) models, which combines an effective field
theory approach with a diagrammatic calculation. It thus achieves an all order
resummation of leading logarithms together with the inclusion of all
non-logarithmic 1-loop contributions. We implement this method into
FlexibleSUSY and study its properties in the MSSM, NMSSM, E6SSM and MRSSM. In
the MSSM, it correctly interpolates between the known results of effective
field theory calculations in the literature for a high SUSY scale and
fixed-order calculations in the full theory for a sub-TeV SUSY scale. We
compare our MSSM results to those from public codes and identify the origin of
the most significant deviations between the DR-bar programs. We then perform a
similar comparison in the remaining three non-minimal models. For all four
models we estimate the theoretical uncertainty of FlexibleEFTHiggs and the
fixed-order DR-bar programs thereby finding that the former becomes more
precise than the latter for a SUSY scale above a few TeV. Even for sub-TeV SUSY
scales, FlexibleEFTHiggs maintains the uncertainty estimate around 2-3 GeV,
remaining a competitive alternative to existing fixed-order computations.


title:
Detecting topological superconductivity using low-frequency doubled
  Shapiro steps

abstract:
  The fractional Josephson effect has been observed in many instances as a
signature of a topological superconducting state containing zero-energy
Majorana modes. We present a nontopological scenario which can produce a
fractional Josephson effect generically in semiconductor-based Josephson
junctions, namely, a resonant impurity bound state weakly coupled to a highly
transparent channel. We show that the fractional ac Josephson effect can be
generated by the Landau-Zener processes which flip the electron occupancy of
the impurity bound state. The Josephson effect signature for Majorana modes
become distinct from this nontopological scenario only at low frequency. We
prove that a variant of the fractional ac Josephson effect, namely, the
low-frequency doubled Shapiro steps, can provide a more reliable signature of
the topological superconducting state.


title:
A study of the Structural Properties of finite $G$-graphs and their
  Characterisation

abstract:
  The $G$-graph $\Gamma(G,S)$ is a graph from the group $G$ generated by
$S\subseteq G$, where the vertices are the right cosets of the cyclic subgroups
$\langle s \rangle, s\in S$ with $k$-edges between two distinct cosets if there
is an intersection of $k$ elements. In this thesis, after presenting some
important properties of $G$-graphs, we show how the $G$-graph depends on the
generating set of the group. We give the $G$-graphs of the symmetric group,
alternating group and the semi-dihedral group with respect to various
generating sets. We give a characterisation of finite $G$-graphs; in the
general case and a bipartite case. Using these characterisations, we give
several classes of graphs that are $G$-graphs. For instance, we consider the
Tur\'{a}n graphs, the platonic graphs and biregular graphs such as the Levi
graphs of geometric configurations. We emphasis the structural properties of
$G$-graphs and their relations to the group $G$ and the generating set $S$.
  As preliminary results for further studies, we give the adjacency matrix and
spectrum of various finite $G$-graphs. As an application, we compute the energy
of these graphs. We also present some preliminary results on infinite
$G$-graphs where we consider the $G$-graphs of the infinite group
$SL_2(\mathbb{Z})$ and an infinite non-Abelian matrix group.


title: The Phoenix galaxy as seen by NuSTAR

abstract:
  Aims. We study the long-term variability of the well-known Seyfert 2 galaxy
Mrk 1210 (a.k.a. UGC 4203, or the Phoenix galaxy).
  Methods. The source was observed by many X-ray facilities in the last 20
years. Here we present a NuSTAR observation and put the results in context of
previously published observations.
  Results. NuSTAR observed Mrk 1210 in 2012 for 15.4 ks. The source showed
Compton-thin obscuration similar to that observed by Chandra, Suzaku, BeppoSAX
and XMM-Newton over the past two decades, but different from the first
observation by ASCA in 1995, in which the active nucleus was caught in a low
flux state - or obscured by Compton-thick matter, with a reflection-dominated
spectrum. Thanks to the high-quality hard X-ray spectrum obtained with NuSTAR
and exploiting the long-term spectral coverage spanning 16.9 years, we can
precisely disentangle the transmission and reflection components and put
constraints on both the intrinsic long-term variability and hidden nucleus
scenarios. In the former case, the distance between the reflector and the
source must be at least ~ 2 pc, while in the latter one the eclipsing cloud may
be identified with a water maser-emitting clump.


title:
Testing for X-ray-SZ Differences and Redshift Evolution in the X-ray
  Morphology of Galaxy Clusters

abstract:
  We present a quantitative study of the X-ray morphology of galaxy clusters,
as a function of their detection method and redshift. We analyze two separate
samples of galaxy clusters: a sample of 36 clusters at 0.35 < z < 0.9 selected
in the X-ray with the ROSAT PSPC 400 deg2 survey, and a sample of 90 clusters
at 0.25 < z < 1.2 selected via the Sunyaev-Zel'dovich (SZ) effect with the
South Pole Telescope. Clusters from both samples have similar-quality Chandra
observations, which allow us to quantify their X-ray morphologies via two
distinct methods: centroid shifts and photon asymmetry. The latter technique
provides nearly unbiased morphology estimates for clusters spanning a broad
range of redshift and data quality. We further compare the X-ray morphologies
of X-ray- and SZ-selected clusters with those of simulated clusters. We do not
find a statistically significant difference in the measured X-ray morphology of
X-ray and SZ-selected clusters over the redshift range probed by these samples,
suggesting that the two are probing similar populations of clusters. We find
that the X-ray morphologies of simulated clusters are statistically
indistinguishable from those of X-ray- or SZ-selected clusters, implying that
the most important physics for dictating the large-scale gas morphology
(outside of the core) is well-approximated in these simulations. Finally, we
find no statistically significant redshift evolution in the X-ray morphology
(both for observed and simulated clusters), over the range z ~ 0.3 to z ~ 1,
seemingly in contradiction with the redshift-dependent halo merger rate
predicted by simulations.


title:
Testing the Completeness of the SDSS Colour Selection for Ultramassive,
  Slowly Spinning Black Holes

abstract:
  We investigate the sensitivity of the colour-based quasar selection algorithm
of the Sloan Digital Sky Survey to several key physical parameters of
supermassive black holes (SMBHs), focusing on BH spin ($a_{\star}$) at the high
BH-mass regime ($M_{BH} \geqslant10^9\, M_{\odot}$). We use a large grid of
model spectral energy distribution, assuming geometrically-thin,
optically-thick accretion discs, and spanning a wide range of five physical
parameters: BH mass $M_{BH}$, BH spin $a_{\star}$, Eddington ratio $L /
L_{Edd}$ , redshift $z$, and inclination angle $inc$. Based on the expected
fluxes in the SDSS imaging ugriz bands, we find that $\sim 99.8\%$ of our
models with $M_{BH} \leqslant 10^{9.5}\, M_{\odot}$ are selected as quasar
candidates and thus would have been targeted for spectroscopic follow-up.
However, in the extremely high-mass regime, $\geqslant 10^{10} M_{\odot}$, we
identify a bias against slowly/retrograde spinning SMBHs. The fraction of SEDs
that would have been selected as quasar candidates drops below $\sim50\%$ for
$a_{\star} <0$ across $0.5<z<2$. For particularly massive BHs, with $M_{BH}
\simeq 3\times10^{10}\, M_{\odot}$, this rate drops below $\sim20\%$, and can
be yet lower for specific redshifts. We further find that the chances of
identifying any hypothetical sources with $M_{BH} = 10^{11}\, M_{\odot}$ by
colour selection would be extremely low at the level of $\sim 3\%$. Our
findings, along with several recent theoretical arguments and empirical
findings, demonstrate that the current understanding of the SMBH population at
the high-$M_{BH}$, and particularly the low- or retrograde-spinning regime, is
highly incomplete.


title:
Application of the Feynman-tree theorem together with BCFW recursion
  relations

abstract:
  Recently, it has been shown that on-shell scattering amplitudes can be
constructed by the Feynman-tree theorem combined with the BCFW recursion
relations. Since the BCFW relations are restricted to tree diagrams, the
preceding application of the Feynman-tree theorem is essential. In this way
amplitudes can be constructed by on-shell and gauge-invariant tree amplitudes.
Here we want to apply this method to the electron-photon vertex correction. We
present all the single, double, and triple phase-space tensor integrals
explicitly and show that the sum of amplitudes coincides with the result of the
conventional calculation of a virtual loop correction.


title: Detailed HI kinematics of Tully-Fisher calibrator galaxies

abstract:
  We present spatially-resolved HI kinematics of 32 spiral galaxies which have
Cepheid or/and Tip of the Red Giant Branch distances, and define a calibrator
sample for the Tully-Fisher relation. The interferometric HI data for this
sample were collected from available archives and supplemented with new GMRT
observations. This paper describes an uniform analysis of the HI kinematics of
this inhomogeneous data set. Our main result is an atlas for our calibrator
sample that presents global HI profiles, integrated HI column-density maps, HI
surface density profiles and, most importantly, detailed kinematic information
in the form of high-quality rotation curves derived from highly-resolved,
two-dimensional velocity fields and position-velocity diagrams.


title: Numerical evaluation of the bispectrum in multiple field inflation

abstract:
  We present a complete framework for numerical calculation of the power
spectrum and bispectrum in canonical inflation with an arbitrary number of
light or heavy fields. Our method includes all relevant effects at tree-level
in the loop expansion, including (i) interference between growing and decaying
modes near horizon exit; (ii) correlation and coupling between species near
horizon exit and on superhorizon scales; (iii) contributions from mass terms;
and (iv) all contributions from coupling to gravity. We track the evolution of
each correlation function from the vacuum state through horizon exit and the
superhorizon regime, with no need to match quantum and classical parts of the
calculation; when integrated, our approach corresponds exactly with the
tree-level Schwinger or 'in-in' formulation of quantum field theory. In this
paper we give the equations necessary to evolve all two- and three-point
correlation functions together with suitable initial conditions. The final
formalism is suitable to compute the amplitude, shape, and scale dependence of
the bispectrum in models with |fNL| of order unity or less, which are a target
for future galaxy surveys such as Euclid, DESI and LSST. As an illustration we
apply our framework to a number of examples, obtaining quantitatively accurate
predictions for their bispectra for the first time. Two accompanying reports
describe publicly-available software packages that implement the method.


title:
CppTransport: a platform to automate calculation of inflationary
  correlation functions

abstract:
  CppTransport is a numerical platform that can automatically generate and
solve the evolution equations for the 2- and 3-point correlation functions (in
field space and for the curvature perturbation) for any inflationary model with
canonical kinetic terms. It makes no approximations beyond the applicability of
tree-level perturbation theory. Given an input Lagrangian, CppTransport
performs symbolic calculations to determine the 'Feynman rules' of the model
and generates efficient C++ to integrate the correlation functions of interest.
It includes a visualization suite that automates extraction of observable
quantities from the raw n-point functions and generates high quality plots with
minimal manual intervention. It is intended to be used as a collaborative
platform, promoting the rapid investigation of models and systematizing their
comparison with observation. This guide describes how to install and use the
system, and illustrates its use through some simple examples.


title:
PyTransport: A Python package for the calculation of inflationary
  correlation functions

abstract:
  PyTransport constitutes a straightforward code written in C++ together with
Python scripts which automatically edit, compile and run the C++ code as a
Python module. It has been written for Unix-like systems (OS X and Linux).
Primarily the module employs the transport approach to inflationary cosmology
to calculate the tree-level power-spectrum and bispectrum of user specified
models of multi-field inflation, accounting for all sub and super-horizon
effects. The transport method we utilise means only coupled differential
equations need to be solved, and the implementation presented here combines the
speed of C++ with the functionality and convenience of Python. This document
details the code and illustrates how to use it with a worked example. It has
been updated to be a companion to the second version of the code, PyTransport
2.0, which includes functionality to deal with models of inflation with a
curved field space metric.


title: Imaging an 80 AU Radius Dust Ring Around the F5V Star HD 157587

abstract:
  We present $H$-band near-infrared polarimetric imaging observations of the
F5V star HD~157587 obtained with the Gemini Planet Imager (GPI) that reveal the
debris disk as a bright ring structure at a separation of $\sim$80$-$100~AU.
The new GPI data complement recent HST/STIS observations that show the disk
extending out to over 500~AU. The GPI image displays a strong asymmetry along
the projected minor axis as well as a fainter asymmetry along the projected
major axis. We associate the minor and major axis asymmetries with polarized
forward scattering and a possible stellocentric offset, respectively. To
constrain the disk geometry we fit two separate disk models to the polarized
image, each using a different scattering phase function. Both models favor a
disk inclination of $\sim 70\degr$ and a $1.5\pm0.6$ AU stellar offset in the
plane of the sky along the projected major axis of the disk. We find that the
stellar offset in the disk plane, perpendicular to the projected major axis is
degenerate with the form of the scattering phase function and remains poorly
constrained. The disk is not recovered in total intensity due in part to strong
adaptive optics residuals, but we recover three point sources. Considering the
system's proximity to the galactic plane and the point sources' positions
relative to the disk, we consider it likely that they are background objects
and unrelated to the disk's offset from the star.


title:
Dynamical Screening of $\alpha$-$\alpha$ Resonant Scattering and Thermal
  Nuclear Scattering Rate in a Plasma

abstract:
  We use effective field theory and thermal field theory to study the dynamical
screening effect in the QED plasma on the $\alpha$-$\alpha$ scattering at the
$^8$Be resonance. Dynamical screening leads to an imaginary part of the
potential which results in a thermal width for the resonance and dominates over
the previously considered static screening effect. As a result, both the
resonance energy and width increase with the plasma temperature. Furthermore,
dynamical screening can have a huge impact on the $\alpha$-$\alpha$ thermal
nuclear scattering rate. For example, when the temperature is around $10$ keV,
the rate is suppressed by a factor of about $900$. We expect similar thermal
suppressions of nuclear reaction rates to occur in those reactions dominated by
an above threshold resonance with a thermal energy. Dynamical screening effects
on nuclear reactions can be relevant to cosmology and astrophysics.


title:
From Exoplanets to Quasars: Detection of Potential Damped Lyman Alpha
  Absorbing Galaxies Using Angular Differential Imaging

abstract:
  The advantages of angular differential imaging (ADI) has been previously
untested in imaging the host galaxies of damped Lyman alpha (DLA) systems. In
this pilot study, we present the first application of ADI to directly imaging
the host galaxy of the DLA seen towards the quasar J1431+3952. K-band imaging
of the field surrounding J1431+3952 was obtained on the Gemini North telescope
with the adaptive optics system and a laser guide star. We computed a
sensitivity curve that demonstrates the sensitivity of our observations as a
function of K-band magnitude, impact parameter and DLA angular size. For an
impact parameter of 0.5" (3.4 kpc at the redshift of the absorber) our mass
sensitivity is log (M_star/M_sun) ~ 9.2 and drops to ~ 9.0 at separations
beyond ~ 6 kpc for the smallest size model galaxy. Three candidate galaxies are
identified within 5". Stellar masses were computed from the K-band photometry
yielding values of log (M_star/M_sun) ~ 9.9, 9.7 and 11.1 respectively. The
likely identification of the absorbing galaxy is discussed, and we conclude
that the galaxy with the largest impact parameter and highest stellar mass is
unlikely to be the host, based on its inconsistency with the N(HI) impact
parameter relation and inconsistent photometric redshift. Whilst we cannot
distinguish between the remaining two candidates as the DLA host, we note that
despite the low spin temperature and relatively high metallicity of the DLA,
the host does not appear to be a particularly luminous (high mass) galaxy.


title: Refining the boundaries of the classical de Sitter landscape

abstract:
  We derive highly constraining no-go theorems for classical de Sitter
backgrounds of string theory, with parallel sources; this should impact the
embedding of cosmological models. We study ten-dimensional vacua of type II
supergravities with parallel and backreacted orientifold Op-planes and
Dp-branes, on four-dimensional de Sitter space-time times a compact manifold.
Vacua for p=3, 7 or 8 are completely excluded, and we obtain tight constraints
for p=4, 5, 6. This is achieved through the derivation of an enlightening
expression for the four-dimensional Ricci scalar. Further interesting
expressions and no-go theorems are obtained. The paper is self-contained so
technical aspects, including conventions, might be of more general interest.


title: One loop graviton corrections to dynamical photons in de Sitter

abstract:
  We employ a recent, general gauge computation of the one loop graviton
contribution to the vacuum polarization on de Sitter to solve for one loop
corrections to the photon mode function. The vacuum polarization takes the form
of a gauge independent, spin 2 contribution and a gauge dependent, spin 0
contribution. We show that the leading secular corrections derive entirely from
the spin 2 contribution.


title:
Bow Ties in the Sky I: The Angular Structure of Inverse Compton
  Gamma-ray Halos in the Fermi Sky

abstract:
  Extended inverse Compton halos are generally anticipated around extragalactic
sources of gamma rays with energies above 100 GeV. These result from inverse
Compton scattered cosmic microwave background photons by a population of
high-energy electron/positron pairs produced by the annihilation of the
high-energy gamma rays on the infrared background. Despite the observed
attenuation of the high-energy gamma rays, the halo emission has yet to be
directly detected. Here, we demonstrate that in most cases these halos are
expected to be highly anisotropic, distributing the up-scattered gamma rays
along axes defined either by the radio jets of the sources or oriented
perpendicular to a global magnetic field. We present a pedagogical derivation
of the angular structure in the inverse Compton halo and provide an analytic
formalism that facilitates the generation of mock images. We discuss exploiting
this fact for the purpose of detecting gamma-ray halos in a set of companion
papers.


title:
Faint Submillimeter Galaxies identified through their
  optical/near-infrared colours I: spatial clustering and halo masses

abstract:
  The properties of submillimeter galaxies (SMGs) that are fainter than the
confusion limit of blank-field single-dish surveys ($S_{850} \lesssim$ 2 mJy)
are poorly constrained. Using a newly developed color selection technique,
Optical-Infrared Triple Color (OIRTC), that has been shown to successfully
{select} such faint SMGs, we identify a sample of 2938 OIRTC-selected galaxies,
dubbed Triple Color Galaxies (TCGs), in the UKIDSS-UDS field. We show that
these galaxies have a median 850 $\mu$m flux of S$_{850} = 0.96\pm0.04$ mJy
(equivalent to a star-formation rate SFR $\sim60-100$ M$_\odot$ yr$^{-1}$ based
on SED fitting), representing the first large sample of faint SMGs that bridges
the gap between bright SMGs and normal star-forming galaxies in S$_{850}$ and
$L_{\rm IR}$. We assess the basic properties of TCGs and their relationship
with other galaxy populations at $z\sim2$. We measure the two-point
autocorrelation function for this population and derive a typical halo mass of
log$_{10}$(M$_{\rm halo}$) $=12.9^{+0.2}_{-0.3}$, $12.7^{+0.1}_{-0.2}$, and
$12.9^{+0.2}_{-0.3}$ $h^{-1}$M$_\odot$ at $z=1-2$, $2-3$, and $3-5$,
respectively. Together with the bright SMGs (S$_{850} \gtrsim 2$ mJy) and a
comparison sample of less far-infrared luminous star-forming galaxies, we find
a lack of dependence between spatial clustering and S$_{850}$ (or SFR),
suggesting that the difference between these populations may lie in their local
galactic environment. Lastly, on the scale of $\sim8-17$ kpc at $1<z<5$ we find
a tentative enhancement of the clustering of TCGs over the comparison
star-forming galaxies, suggesting that some faint SMGs are physically
associated pairs, perhaps reflecting a merging origin in their triggering.


title: QED-driven laser absorption

abstract:
  Absorption covers the physical processes which convert intense photon flux
into energetic particles when a high-power laser illuminates optically-thick
matter. It underpins important petawatt-scale applications today, e.g.,
medical-quality proton beam production. However, development of
ultra-high-field applications has been hindered since no study so far has
described absorption throughout the entire transition from the classical to the
quantum electrodynamical (QED) regime of plasma physics. Here we present a
model of absorption that holds over an unprecedented six orders-of-magnitude in
optical intensity and lays the groundwork for QED applications of laser-driven
particle beams. We demonstrate 58% efficient \gamma-ray production at
$1.8\times 10^{25}~\mathrm{W~ cm^{-2}}$ and the creation of an anti-matter
source achieving $4\times 10^{24}\ \mathrm{positrons}\ \mathrm{cm^{-3}}$,
$10^{6}~\times$ denser than of any known photonic scheme. These results will
find applications in scaled laboratory probes of black hole and pulsar winds,
\gamma-ray radiography for materials science and homeland security, and
fundamental nuclear physics.


title: A Floquet Model for the Many-Body Localization Transition

abstract:
  The nature of the dynamical quantum phase transition between the many-body
localized (MBL) phase and the thermal phase remains an open question, and one
line of attack on this problem is to explore this transition numerically in
finite-size systems. To maximize the contrast between the MBL phase and the
thermal phase in such finite-size systems, we argue one should choose a Floquet
model with no local conservation laws and rapid thermalization to "infinite
temperature" in the thermal phase. Here we introduce and explore such a Floquet
spin chain model, and show that standard diagnostics of the MBL-to-thermal
transition behave well in this model even at modest sizes. We also introduce a
physically motivated spacetime correlation function which peaks at the
transition in the Floquet model, but is strongly affected by conservation laws
in Hamiltonian models.


title:
The MASSIVE Survey - V. Spatially-Resolved Stellar Angular Momentum,
  Velocity Dispersion, and Higher Moments of the 41 Most Massive Local
  Early-Type Galaxies

abstract:
  We present spatially-resolved two-dimensional stellar kinematics for the 41
most massive early-type galaxies (MK <~ -25.7 mag, stellar mass M* >~ 10^11.8
Msun) of the volume-limited (D < 108 Mpc) MASSIVE survey. For each galaxy, we
obtain high-quality spectra in the wavelength range of 3650 to 5850 A from the
246-fiber Mitchell integral-field spectrograph (IFS) at McDonald Observatory,
covering a 107" x 107" field of view (often reaching 2 to 3 effective radii).
We measure the 2-D spatial distribution of each galaxy's angular momentum
(lambda and fast or slow rotator status), velocity dispersion (sigma), and
higher-order non-Gaussian velocity features (Gauss-Hermite moments h3 to h6).
Our sample contains a high fraction (~80% ) of slow and non-rotators with
lambda <~ 0.2. When combined with the lower-mass ETGs in the ATLAS3D survey, we
find the fraction of slow-rotators to increase dramatically with galaxy mass,
reaching ~50% at MK ~ -25.5 mag and ~90% at MK <~ -26 mag. All of our fast
rotators show a clear anti-correlation between h3 and V/sigma, and the slope of
the anti-correlation is steeper in more round galaxies. The radial profiles of
sigma show a clear luminosity and environmental dependence: the 12 most
luminous galaxies in our sample (MK <~ -26 mag) are all brightest cluster/group
galaxies (except NGC 4874) and all have rising or nearly flat sigma profiles,
whereas five of the seven "isolated" galaxies are all fainter than MK = -25.8
mag and have falling sigma. All of our galaxies have positive average h4; the
most luminous galaxies have average h4 ~ 0.05 while less luminous galaxies have
a range of values between 0 and 0.05. Most of our galaxies show positive radial
gradients in h4, and those galaxies also tend to have rising sigma profiles. We
discuss the implications for the relationship among dynamical mass, sigma, h4,
and velocity anisotropy for these massive galaxies.


title:
The donor of Aquila X-1 revealed by high angular resolution
  near-infrared spectroscopy

abstract:
  The low mass X-ray binary Aquila X-1 is one of the most active neutron star
X-ray transients. Despite it has a relatively bright quiescent optical
counterpart, the detection of its companion has been hampered by the presence
of a nearby interloper star. Using the infrared integral field spectrograph
SINFONI on the VLT-8.2m telescope, we unambiguously single out Aquila X-1 from
the interloper. Phase-resolved near infrared spectroscopy reveals absorption
features from a K4 +- 2 companion star moving at a projected velocity of K_2=
136 +- 4 km/s. We here present the first dynamical solution and associated
fundamental parameters of Aquila X-1, imposing new constraints to the orbital
inclination (36 deg < i < 47 deg) and the distance (d = 6 +- 2 kpc) to this
prototypical neutron star transient.


title: On the thermodynamics of scale factor dual Universes

abstract:
  The thermodynamical aspects of the conformal time scale factor duality (SFD)
of cosmological models within Einstein Gravity are investigated. We derive the
SFD transformations of the thermodynamical quantities describing the thermal
evolution of the matter fluid and of the apparent horizon. The thermodynamical
properties of the self-dual cosmological models with a modified Chaplygin gas
are studied in detail. We deduce the restrictions on the equation of state
parameters that allow to extend scale factor duality as a UV/IR symmetry of the
cosmological models consistent with their thermodynamical behavior.


title: 60dB high-extinction auto-configured Mach--Zehnder interferometer

abstract:
  Imperfections in integrated photonics manufacturing have a detrimental effect
on the maximal achievable visibility in interferometric architectures. These
limits have profound implications for further photonics technological
developments and in particular for quantum photonics technologies. Active
optimisation approaches, together with reconfigurable photonics, have been
proposed as a solution to overcome this. In this paper, we demonstrate an
ultra-high (>60 dB) extinction ratio in a silicon photonic device consisting of
cascaded Mach-Zehnder interferometers, in which additional interferometers
function as variable beamsplitters. The imperfections of fabricated
beamsplitters are compensated using an automated progressive optimization
algorithm with no requirement for pre-calibration. This work shows the
possibility of integrating and accurately controlling linear-optical components
for large-scale quantum information processing and other applications.


title:
Anisotropically Weighted and Nonholonomically Constrained Evolutions on
  Manifolds

abstract:
  We present evolution equations for a family of paths that results from
anisotropically weighting curve energies in non-linear statistics of manifold
valued data. This situation arises when performing inference on data that have
non-trivial covariance and are anisotropic distributed. The family can be
interpreted as most probable paths for a driving semi-martingale that through
stochastic development is mapped to the manifold. We discuss how the paths are
projections of geodesics for a sub-Riemannian metric on the frame bundle of the
manifold, and how the curvature of the underlying connection appears in the
sub-Riemannian Hamilton-Jacobi equations. Evolution equations for both metric
and cometric formulations of the sub-Riemannian metric are derived. We
furthermore show how rank-deficient metrics can be mixed with an underlying
Riemannian metric, and we relate the paths to geodesics and polynomials in
Riemannian geometry. Examples from the family of paths are visualized on
embedded surfaces, and we explore computational representations on finite
dimensional landmark manifolds with geometry induced from right-invariant
metrics on diffeomorphism groups.


title: Language Classes Associated with Automata Over Matrix Groups

abstract:
  We investigate the language classes recognized by group automata over matrix
groups. We present a summary of the results obtained so far together with a
number of new results. We look at the computational power of time-bounded group
automata where the group under consideration has polynomial growth.


title:
Late-time decay of coupled electromagnetic and gravitational
  perturbations outside an extremal charged black hole

abstract:
  In this paper we employ the results of a previous paper on the late-time
decay of scalar-field perturbations of an extreme Reissner-Nordstrom black
hole, in order to find the late-time decay of coupled electromagnetic and
gravitational perturbations of this black hole. We explicitly write the
late-time tails of Moncrief's gauge invariant variables and of the
perturbations of the metric tensor and the electromagnetic field tensor in the
Regge-Wheeler gauge. We discuss some of the consequences of the results and
relations to previous works.


title: Net Baryon Fluctuations from a Crossover Equation of State

abstract:
  We have constructed an equation of state which smoothly interpolates between
an excluded volume hadron resonance gas at low energy density to a plasma of
quarks and gluons at high energy density. This crossover equation of state
agrees very well with lattice calculations at both zero and nonzero baryon
chemical potential. We use it to compute the variance, skewness, and kurtosis
of fluctuations of baryon number, and compare to measurements of proton number
fluctuations in central Au-Au collisions as measured by the STAR collaboration
in a beam energy scan at the Relativistic Heavy Ion Collider. The crossover
equation of state can reproduce the data if the fluctuations are frozen out at
temperatures well below than the average chemical freeze-out.


title:
Can the relic density of self-interacting dark matter be due to
  annihilations into Standard Model particles?

abstract:
  Motivated by the hypothesis that dark matter self-interactions provide a
solution to the small-scale structure formation problems, we investigate the
possibilities that the relic density of a self-interacting dark matter
candidate can proceed from the thermal freeze-out of annihilations into
Standard Model particles. We find that scalar and Majorana dark matter in the
mass range of $10-500$ MeV, coupled to a slightly heavier massive gauge boson,
are the only possible candidates in agreement with multiple current
experimental constraints. Here dark matter annihilations take place at a much
slower rate than the self-interactions simply because the interaction
connecting the Standard Model and the dark matter sectors is small. We also
discuss prospects of establishing or excluding these two scenarios in future
experiments.


title:
On an invariant bilinear form on the space of automorphic forms via
  asymptotics

abstract:
  This article concerns the study of a new invariant bilinear form $\mathcal B$
on the space of automorphic forms of a split reductive group $G$ over a
function field. We define $\mathcal B$ using the asymptotics maps from
Bezrukavnikov-Kazhdan and Sakellaridis-Venkatesh, which involve the geometry of
the wonderful compactification of $G$. We show that $\mathcal B$ is naturally
related to miraculous duality in the geometric Langlands program through the
functions-sheaves dictionary. In the proof, we highlight the connection between
the classical non-Archimedean Gindikin-Karpelevich formula and certain
factorization algebras acting on geometric Eisenstein series. We then give
another definition of $\mathcal B$ using the constant term operator and the
inverse of the standard intertwining operator. The form $\mathcal B$ defines an
invertible operator $L$ from the space of compactly supported automorphic forms
to a new space of "pseudo-compactly" supported automorphic forms. We give a
formula for $L^{-1}$ in terms of pseudo-Eisenstein series and constant term
operators which suggests that $L^{-1}$ is an analog of the Aubert-Zelevinsky
involution.


title:
Time-multiplexed amplification in a hybrid-less and coil-less Josephson
  parametric converter

abstract:
  Josephson parametric converters (JPCs) are superconducting devices capable of
performing nondegenerate, three-wave mixing in the microwave domain without
losses. One drawback limiting their use in scalable quantum architectures is
the large footprint of the auxiliary circuit needed for their operation, in
particular, the use of off-chip, bulky, broadband hybrids and magnetic coils.
Here, we realize a JPC which eliminates the need for these bulky components.
The pump drive and flux bias are applied in the new device through an on-chip,
lossless, three-port power divider and on-chip flux line, respectively. We show
that the new design considerably simplifies the circuit and reduces the
footprint of the device while maintaining a comparable performance to
state-of-the-art JPCs. Furthermore, we exploit the tunable bandwidth property
of the JPC and the added capability of applying alternating currents to the
flux line in order to switch the resonance frequencies of the device, hence
demonstrating time-multiplexed amplification of microwave tones that are
separated by more than the dynamical bandwidth of the amplifier. Such a
measurement technique can potentially serve to perform time-multiplexed,
high-fidelity readout of superconducting qubits.


title:
Multivariate Location and Scatter Matrix Estimation Under Cellwise and
  Casewise Contamination

abstract:
  We consider the problem of multivariate location and scatter matrix
estimation when the data contain cellwise and casewise outliers. Agostinelli et
al. (2015) propose a two-step approach to deal with this problem: first, apply
a univariate filter to remove cellwise outliers and second, apply a generalized
S-estimator to downweight casewise outliers. We improve this proposal in three
main directions. First, we introduce a consistent bivariate filter to be used
in combination with the univariate filter in the first step. Second, we propose
a new fast subsampling procedure to generate starting points for the
generalized S-estimator in the second step. Third, we consider a non-monotonic
weight function for the generalized S-estimator to better deal with casewise
outliers in high dimension. A simulation study and real data example show that,
unlike the original two-step procedure, the modified two-step approach performs
and scales well for high dimension. Moreover, the modified procedure
outperforms the original one and other state-of-the-art robust procedures under
cellwise and casewise data contamination.


title:
Laboratory Measurements of the K-shell transition energies in L-shell
  ions of Si and S

abstract:
  We have measured the energies of the strongest 1s-2ell (ell=s,p) transitions
in He- through Ne-like silicon and sulfur ions to an accuracy of better than
1eV using Lawrence Livermore National Laboratory's electron beam ion traps,
EBIT-I and SuperEBIT, and the NASA/GSFC EBIT Calorimeter Spectrometer (ECS). We
identify and measure the energies of 18 and 21 X-ray features from silicon and
sulfur, respectively. The results are compared to new Flexible Atomic Code
calculations and to semi-relativistic Hartree Fock calculations by Palmeri et
al. (2008). These results will be especially useful for wind diagnostics in
high mass X-ray binaries, such as Vela X-1 and Cygnus X-1, where
high-resolution spectral measurements using Chandra's high energy transmission
grating has made it possible to measure Doppler shifts of 100km/s. The accuracy
of our measurements is consistent with that needed to analyze Chandra
observations, exceeding Chandra's 100km/s limit. Hence, the results presented
here not only provide benchmarks for theory, but also accurate rest energies
that can be used to determine the bulk motion of material in astrophysical
sources. We show the usefulness of our results by applying them to redetermine
Doppler shifts from Chandra observations of Vela X-1.


title: Comments on "On q-non-extensive statistics with non-Tsallisian entropy"

abstract:
  Recently, in [P. Jizba and J. Korbel, Physica A 444, 2016, 808-827], four
generalized Shannon-Khinchin [GSK] axioms have been proposed and a generalized
entropy which uniquely satisfies the GSK axioms has been derived. In this
comment, we show that the unique class of the entropies derived in the
aforementioned paper is not correct, as it violates the fourth GSK axiom, and
we derive the correct one. Nevertheless, the class of entropies proposed in the
commented paper still can serve as a basis for generalized statistical
mechanics. We propose a new axiomatic system which characterizes the class of
entropies.


title:
Angular dependence of giant Zeeman effect for semi-magnetic cavity
  polaritons

abstract:
  The observation of spin-related phenomena of microcavity polaritons has been
limited due to weak Zeeman effect of non-magnetic semiconductors. We
demonstrate that the incorporation of magnetic ions into quantum wells placed
in a non-magnetic microcavity results in enhanced effects of magnetic field on
exciton-polaritons. We show that in such a structure the Zeeman splitting of
exciton-polaritons strongly depends on the photon - exciton detuning and
polariton wavevector. Our experimental data are explained by a model where the
impact of magnetic field on the lower polariton state is directly inherited
from the excitonic component, and the coupling strength to cavity photon is
modified by external magnetic field.


title:
Antisymmetric Couplings Enable Direct Observation of Chirality in
  Nuclear Magnetic Resonance Spectroscopy

abstract:
  Here we demonstrate that a term in the nuclear spin Hamiltonian, the
antisymmetric \textit{J}-coupling, is fundamentally connected to molecular
chirality. We propose and simulate a nuclear magnetic resonance (NMR)
experiment to observe this interaction and differentiate between enantiomers
without adding any additional chiral agent to the sample. The antisymmetric
\textit{J}-coupling may be observed in the presence of molecular orientation by
an external electric field. The opposite parity of the antisymmetric coupling
tensor and the molecular electric dipole moment yields a sign change of the
observed coupling between enantiomers. We show how this sign change influences
the phase of the NMR spectrum and may be used to discriminate between
enantiomers.


title: Cosmology in Weyl Transverse Gravity

abstract:
  We study the Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmology in the
Weyl-transverse (WTDiff) gravity in a general space-time dimension. The WTDiff
gravity is invariant under both the local Weyl (conformal) transformation and
the volume preserving diffeormorphisms (transverse diffeomorphisms) and is
believed to be equivalent to general relativity at least at the classical level
(perhaps, even in the quantum regime). It is explicitly shown by solving the
equations of motion that the FLRW metric is a classical solution in the WTDiff
gravity only when the spatial metric is flat, that is, the Euclidean space, and
the lapse function is a nontrivial function of the scale factor.


title: Defeating Image Obfuscation with Deep Learning

abstract:
  We demonstrate that modern image recognition methods based on artificial
neural networks can recover hidden information from images protected by various
forms of obfuscation. The obfuscation techniques considered in this paper are
mosaicing (also known as pixelation), blurring (as used by YouTube), and P3, a
recently proposed system for privacy-preserving photo sharing that encrypts the
significant JPEG coefficients to make images unrecognizable by humans. We
empirically show how to train artificial neural networks to successfully
identify faces and recognize objects and handwritten digits even if the images
are protected using any of the above obfuscation techniques.


title: Spanier-Whitehead K-duality for $C^*$-algebras

abstract:
  Classical Spanier-Whitehead duality was introduced for the stable homotopy
category of finite CW complexes. Here we provide a comprehensive treatment of a
noncommutative version, termed Spanier-Whitehead $K$-duality, which is defined
on the category of $C^*$-algebras whose $K$-theory is finitely generated and
that satisfy the UCT with morphisms the $KK$-groups. We explore what happens
when these assumptions are relaxed in various ways. In particular, we consider
the relationship between Paschke duality and Spanier-Whitehead $K$-duality.


title:
On the local-global divisibility of torsion points on elliptic curves
  and ${\rm GL}_2$-type varieties

abstract:
  Let $p$ be a prime number and let $k$ be a number field. Let $E$ be an
elliptic curve defined over $k$. We prove that if $p$ is odd, then the
local-global divisibility by any power of $p$ holds for the torsion points of
$E$. We also show with an example that the hypothesis over $p$ is necessary.
  We get a weak generalization of the result on elliptic curves to the larger
family of ${\rm GL}_2$-type varieties over $k$. In the special case of the
abelian surfaces $A/k$ with quaternionic multiplication over $k$ we obtain that
for all prime $p$, except a finite number depending on $A$, the local-global
divisibility by any power of $p$ holds for the torsion points of $A$


title:
Pullback attractors for a class of non-autonomous thermoelastic plate
  systems

abstract:
  In this article we study the asymptotic behavior of solutions, in sense of
global pullback attractors, of the evolution system $$ \begin{cases} u_{tt}
+\eta\Delta^2 u+a(t)\Delta\theta=f(t,u), & t>\tau,\ x\in\Omega,\\
\theta_t-\kappa\Delta \theta-a(t)\Delta u_t=0, & t>\tau,\ x\in\Omega,
\end{cases} $$ subject to boundary conditions $$ u=\Delta u=\theta=0,\ t>\tau,\
x\in\partial\Omega, $$ where $\Omega$ is a bounded domain in $\mathbb{R}^N$
with $N\geqslant 2$, which boundary $\partial\Omega$ is assumed to be a
$\mathcal{C}^4$-hypersurface, $\eta>0$ and $\kappa>0$ are constants, $a$ is an
H\"older continuous function, $f$ is a dissipative nonlinearity locally
Lipschitz in the second variable.


title:
An asymptotic preserving method for transport equations with oscillatory
  scattering coefficients

abstract:
  We design a numerical scheme for transport equations with oscillatory
periodic scattering coefficients. The scheme is asymptotic preserving in the
diffusion limit as Knudsen number goes to zero. It also captures the
homogenization limit as the length scale of the scattering coefficient goes to
zero. The proposed method is based on the construction of multiscale finite
element basis and a Galerkin projection based on the even-odd decomposition.
The method is analyzed in the asymptotic regime, as well as validated
numerically.


title:
Hyperbolic Metamaterials and Coupled Surface Plasmon Polaritons:
  comparative analysis

abstract:
  We investigate the optical properties of sub-wavelength layered
metal/dielectric structures, also known as hyperbolic metamaterials (HMMs),
using exact analytical Kronig Penney (KP) model. We show that hyperbolic
isofrequency surfaces exist for all combinations of layer permittivities and
thicknesses, and the largest Purcell enhancements (PE) of spontaneous radiation
are achieved away from the nominally hyperbolic region. Detailed comparison of
field distributions, dispersion curves, and Purcell factors (PF) between the
HMMs and Surface Plasmon Polaritons (SPPs) guided modes in metal/dielectric
waveguides demonstrates that HMMs are nothing but weakly coupled gap or slab
SPPs modes. Broadband PE is not specific to the HMMs and can be easily attained
in single thin metallic layers. Furthermore, large wavevectors and PE are
always combined with high loss, short propagation distances and large
impedances; hence PE in HMMs is essentially a direct coupling of the energy
into the free electron motion in the metal, or quenching of radiative lifetime.
PE in HMMs is not related to the hyperbolicity per se but is simply the
consequence of the strong dispersion of permittivity in the metals or polar
dielectrics, as our conclusions are relevant also for the infrared HMMs
occurring in nature. When it comes to enhancement of radiating processes and
field concentrations, HMMs are not superior to far simpler plasmonic
structures.


title:
Magnetic Field Induced Vortex Lattice Transition in
  HgBa$_{2}$CuO$_{4+\delta}$

abstract:
  Measurements of the $^{17}$O nuclear magnetic resonance (NMR) quadrupolar
spectrum of apical oxygen in HgBa$_{2}$CuO$_{4+\delta}$ were performed over a
range of magnetic fields from 6.4 to 30\,T in the superconducting state. Oxygen
isotope exchanged single crystals were investigated with doping corresponding
to superconducting transition temperatures from 74\,K underdoped, to 78\,K
overdoped. The apical oxygen site was chosen since its NMR spectrum has narrow
quadrupolar satellites that are well separated from any other resonance.
Non-vortex contributions to the spectra can be deconvolved in the time domain
to determine the local magnetic field distribution from the vortices. Numerical
analysis using Brandt's Ginzburg-Landau theory was used to find structural
parameters of the vortex lattice, penetration depth, and coherence length as a
function of magnetic field in the vortex solid phase. From this analysis we
report a vortex structural transition near 15\,T from an oblique lattice with
an opening angle of $73^{\circ}$ at low magnetic fields to a triangular lattice
with $60^{\circ}$ stabilized at high field. The temperature for onset of vortex
dynamics has been identified with vortex lattice melting. This is independent
of the magnetic field at sufficiently high magnetic field similar to that
reported for YBa$_2$Cu$_3$O$_7$ and Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$
and is correlated with mass anisotropy of the material. This behavior is
accounted for theoretically only in the limit of very high anisotropy.


title:
Does Infrastructure Investment Lead to Economic Growth or Economic
  Fragility? Evidence from China

abstract:
  The prevalent view in the economics literature is that a high level of
infrastructure investment is a precursor to economic growth. China is
especially held up as a model to emulate. Based on the largest dataset of its
kind, this paper punctures the twin myths that, first, infrastructure creates
economic value, and, second, China has a distinct advantage in its delivery.
Far from being an engine of economic growth, the typical infrastructure
investment fails to deliver a positive risk adjusted return. Moreover, China's
track record in delivering infrastructure is no better than that of rich
democracies. Where investments are debt-financed, overinvesting in unproductive
projects results in the buildup of debt, monetary expansion, instability in
financial markets, and economic fragility, exactly as we see in China today. We
conclude that poorly managed infrastructure investments are a main explanation
of surfacing economic and financial problems in China. We predict that, unless
China shifts to a lower level of higher-quality infrastructure investments, the
country is headed for an infrastructure-led national financial and economic
crisis, which is likely also to be a crisis for the international economy.
China's infrastructure investment model is not one to follow for other
countries but one to avoid.


title: An atom interferometer with a shaken optical lattice

abstract:
  We introduce shaken lattice interferometry with atoms trapped in a
one-dimensional optical lattice. By phase modulating (shaking) the lattice, we
control the momentum state of the atoms. Through a sequence of shaking
functions, the atoms undergo an interferometer sequence of splitting,
propagation, reflection, reverse propagation, and recombination. Each shaking
function in the sequence is optimized with a genetic algorithm to achieve the
desired momentum state transitions. As with conventional atom interferometers,
the sensitivity of the shaken lattice interferometer increases with
interrogation time. The shaken lattice interferometer may also be optimized to
sense signals of interest while rejecting others, such as the measurement of an
AC inertial signal in the presence of an unwanted DC signal.


title:
The MARS15-based FermiCORD code system for calculation of the
  accelerator-induced residual dose

abstract:
  The FermiCORD code system, a set of codes based on MARS15 that calculates the
accelerator-induced residual doses at experimental facilities of arbitrary
configurations, has been developed. FermiCORD is written in C++ as an add-on to
Fortran-based MARS15. The FermiCORD algorithm consists of two stages: 1)
simulation of residual doses on contact with the surfaces surrounding the
studied location and of radionuclide inventories in the structures surrounding
those locations using MARS15, and 2) simulation of the emission of the nuclear
decay $\gamma$-quanta by the residuals in the activated structures and scoring
the prompt doses of these $\gamma$-quanta at arbitrary distances from those
structures. The FermiCORD code system has been benchmarked against similar
algorithms based on other code systems and against experimental data from the
CERF facility at CERN, and FermiCORD showed reasonable agreement with these.
The code system has been applied for calculation of the residual dose of the
target station for the Mu2e experiment and the results have been compared to
approximate dosimetric approaches.


title: Topical Review: Spins and mechanics in diamond

abstract:
  There has been rapidly growing interest in hybrid quantum devices involving a
solid-state spin and a macroscopic mechanical oscillator. Such hybrid devices
create exciting opportunities to mediate interactions between disparate qubits
and to explore the quantum regime of macroscopic mechanical objects. In
particular, a system consisting of the nitrogen-vacancy defect center in
diamond coupled to a high quality factor mechanical oscillator is an appealing
candidate for such a hybrid quantum device, as it utilizes the highly coherent
and versatile spin properties of the defect center. In this paper, we will
review recent experimental progress on diamond-based hybrid quantum devices in
which the spin and orbital dynamics of single defects are driven by the motion
of a mechanical oscillator. In addition, we discuss prospective applications
for this device, including long range, phonon-mediated spin-spin interactions,
and phonon cooling in the quantum regime. We conclude the review by evaluating
the experimental limitations of current devices and identifying alternative
device architectures that may reach the strong coupling regime.


title: Spatially Correlated Content Caching for Device-to-Device Communications

abstract:
  We study optimal geographic content placement for device-to-device (D2D)
networks in which each file's popularity follows the Zipf distribution. The
locations of the D2D users (caches) are modeled by a Poisson point process
(PPP) and have limited communication range and finite storage. Inspired by the
Mat\'{e}rn hard-core (type II) point process that captures pairwise
interactions between nodes, we devise a novel spatially correlated caching
strategy called {\em hard-core placement} (HCP) such that the D2D nodes caching
the same file are never closer to each other than the {\em exclusion radius}.
The exclusion radius plays the role of a substitute for caching probability. We
derive and optimize the exclusion radii to maximize the {\em hit probability},
which is the probability that a given D2D node can find a desired file at
another node's cache within its communication range. Contrasting it with
independent content placement, which is used in most prior work, our HCP
strategy often yields a significantly higher cache hit probability. We further
demonstrate that the HCP strategy is effective for small cache sizes and a
small communication radius, which are likely conditions for D2D.


title: Note on von Neumann and R\'enyi entropies of a Graph

abstract:
  We conjecture that all connected graphs of order $n$ have von Neumann entropy
at least as great as the star $K_{1,n-1}$ and prove this for almost all graphs
of order $n$. We show that connected graphs of order $n$ have R\'enyi 2-entropy
at least as great as $K_{1,n-1}$ and for $\alpha>1$, $K_n$ maximizes R\'enyi
$\alpha$-entropy over graphs of order $n$. We show that adding an edge to a
graph can lower its von Neumann entropy.


title: Lattice methods and the nuclear few- and many-body problem

abstract:
  We begin with a brief overview of lattice calculations using chiral effective
field theory and some recent applications. We then describe several methods for
computing scattering on the lattice. After that we focus on the main goal,
explaining the theory and algorithms relevant to lattice simulations of nuclear
few- and many-body systems. We discuss the exact equivalence of four different
lattice formalisms, the Grassmann path integral, transfer matrix operator,
Grassmann path integral with auxiliary fields, and transfer matrix operator
with auxiliary fields. Along with our analysis we include several coding
examples and a number of exercises for the calculations of few- and many-body
systems at leading order in chiral effective field theory.


title:
Nuclear relaxation rates in the Herbertsmithite Kagome antiferromagnets
  ZnCu3(OH)6Cl2

abstract:
  Local spectral functions and Nuclear Magnetic Relaxation (NMR) rates, 1/T1,
for the spin-half Heisenberg antiferromagnet on the Kagome Lattice are
calculated using Moriyas Gaussian approximation, as well as through an
extrapolation of multiple frequency moments. The temperature dependence of the
calculated rates is compared with the oxygen 1/T1 NMR data in Herbertsmithite.
We find that the Gaussian approximation for 1/T1 shows behavior qualitatively
similar to experiments with a sharp drop in rates at low temperatures,
consistent with a spin-gapped behavior. However, this approximation
significantly underestimates the magnitude of 1/T1 even at room temperature.
Rates obtained from extrapolation of multiple frequency moments give very good
agreement with the room temperature NMR data with J = 195 +/- 20 K and
hyperfine couplings determined independently from other measurements. The use
of multiple frequency moments also leads to additional low frequency weight in
the local structure factors. The convergence of our calculations with higher
frequency moments breaks down at low temperatures suggesting the existence of
longer range dynamic correlations in the system despite the very short-range
static correlations.


title: Night sky brightness at San Pedro Martir Observatory

abstract:
  We present optical UBVRI zenith night sky brightness measurements collected
on eighteen nights during 2013--2016 and SQM measurements obtained daily over
twenty months during 2014--2016 at the Observatorio Astronomico Nacional on the
Sierra San Pedro Martir (OAN-SPM) in Mexico. The UBVRI data is based upon CCD
images obtained with the 0.84m and 2.12m telescopes, while the SQM data is
obtained with a high-sensitivity, low-cost photometer. The typical moonless
night sky brightness at zenith averaged over the whole period is U = 22.68, B =
23.10, V = 21.84, R = 21.04, I = 19.36, and SQM = 21.88 mag/square arcsec, once
corrected for zodiacal light. We find no seasonal variation of the night sky
brightness measured with the SQM. The typical night sky brightness values found
at OAN-SPM are similar to those reported for other astronomical dark sites at a
similar phase of the solar cycle. We find a trend of decreasing night sky
brightness with decreasing solar activity during period of the observations.
This trend implies that the sky has become darker by delta_U =0.7, delta_B
=0.5, delta_V =0.3, delta_R =0.5 mag/square arcsec since early 2014 due to the
present solar cycle.


title: Multi-Path Low Delay Network Codes

abstract:
  The capability of mobile devices to use multiple interfaces to support a
single session is becoming more prevalent. Prime examples include the desire to
implement WiFi offloading and the introduction of 5G. Furthermore, an
increasing fraction of Internet traffic is becoming delay sensitive. These two
trends drive the need to investigate methods that enable communication over
multiple parallel heterogeneous networks, while also ensuring that delay
constraints are met. This paper approaches these challenges using a multi-path
streaming code that uses forward error correction to reduce the in-order
delivery delay of packets in networks with poor link quality and transient
connectivity. A simple analysis is developed that provides a good approximation
of the in-order delivery delay. Furthermore, numerical results help show that
the delay penalty of communicating over multiple paths is insignificant when
considering the potential throughput gains obtained through the fusion of
multiple networks.


title: Identifying Dogmatism in Social Media: Signals and Models

abstract:
  We explore linguistic and behavioral features of dogmatism in social media
and construct statistical models that can identify dogmatic comments. Our model
is based on a corpus of Reddit posts, collected across a diverse set of
conversational topics and annotated via paid crowdsourcing. We operationalize
key aspects of dogmatism described by existing psychology theories (such as
over-confidence), finding they have predictive power. We also find evidence for
new signals of dogmatism, such as the tendency of dogmatic posts to refrain
from signaling cognitive processes. When we use our predictive model to analyze
millions of other Reddit posts, we find evidence that suggests dogmatism is a
deeper personality trait, present for dogmatic users across many different
domains, and that users who engage on dogmatic comments tend to show increases
in dogmatic posts themselves.


title:
New Rain Rate Statistics for Emerging Regions: Implications for Wireless
  Backhaul Planning

abstract:
  As demand for broadband service increases in emerging regions, high-capacity
wireless links can accelerate and cost-reduce the deployment of new networks
(both backhaul and customer site connection). Such links are increasingly
common in developed countries, but their reliability in emerging regions is
questioned where very heavy tropical rain is present. Here, we investigate the
robustness of the standard (ITU-R P.837-6) method for estimating rain rates
using an expanded test dataset. We illustrate how bias/variance issues cause
problematic predictions at higher rain rates. We confirm (by construction) that
an improved rainfall climatology can largely address these prediction issues
without compromising standard ITU fit evaluation metrics.


title:
No Time to Observe: Adaptive Influence Maximization with Partial
  Feedback

abstract:
  Although influence maximization problem has been extensively studied over the
past ten years, majority of existing work adopt one of the following models:
\emph{full-feedback model} or \emph{zero-feedback model}. In the zero-feedback
model, we have to commit the seed users all at once in advance, this strategy
is also known as non-adaptive policy. In the full-feedback model, we select one
seed at a time and wait until the diffusion completes, before selecting the
next seed. Full-feedback model has better performance but potentially huge
delay, zero-feedback model has zero delay but poorer performance since it does
not utilize the observation that may be made during the seeding process. To
fill the gap between these two models, we propose \emph{Partial-feedback
Model}, which allows us to select a seed at any intermediate stage. We develop
two novel greedy policies that, for the first time, achieve bounded
approximation ratios under both uniform and non-uniform cost settings.


title:
A Birman-Series type result for geodesics with infinitely many
  self-intersections

abstract:
  Given a hyperbolic surface $\S$, a classic result of Birman and Series states
that for each $K$, all complete geodesics with at most $K$ self-intersections
can only pass through a certain nowhere dense, Hausdorff dimension 1 subset of
$\S$. We define a self-intersection function for each complete geodesic, which
bounds the number of self-intersections in finite length subarcs. We then
extend the Birman-Series result to sets of complete geodesics with certain
bounds on their self-intersection functions. In fact, we get the same
conclusion as the Birman-Series result for sets of complete geodesics whose
self-intersection functions are in $o(l^2)$, where $l$ measures arclength.


title:
NbN superconducting nanowire single photon detector with efficiency over
  90% at 1550 nm wavelength operational at compact cryocooler temperature

abstract:
  The fast development of superconducting nanowire single photon detector
(SNSPD) in the past decade has enabled many advances in quantum information
technology. The best system detection efficiency (SDE) record at 1550 nm
wavelength was 93% obtained from SNSPD made of amorphous WSi which usually
operated at sub-kelvin temperatures. We first demonstrate SNSPD made of
polycrystalline NbN with SDE of 90.2% for 1550 nm wavelength at 2.1K,
accessible with a compact cryocooler. The SDE saturated to 92.1% when the
temperature was lowered to 1.8K. The results lighten the practical and high
performance SNSPD to quantum information and other high-end applications.


title:
Ab initio effective rotational and rovibrational Hamiltonians for
  non-rigid systems via curvilinear second order vibrational M{\o}ller-Plesset
  perturbation theory

abstract:
  We present a perturbative method for ab initio calculations of rotational and
rovibrational effective Hamiltonians of both rigid and non-rigid molecules. Our
approach is based on a curvilinear implementation of second order vibrational
M{\o}ller-Plesset perturbation theory (VMP2) extended to include rotational
effects via a second order contact transformation. Though more expensive, this
approach is significantly more accurate than standard second order vibrational
perturbation theory (VPT2) for systems that are poorly described to zeroth
order by rectilinear normal mode harmonic oscillators. We apply this method and
demonstrate its accuracy on two molecules: Si$_2$C, a quasilinear triatomic
with significant bending anharmonicity, and CH$_3$NO$_2$, which contains a
completely unhindered methyl rotor. In addition to these two examples, we
discuss several key technical aspects of the method, including an efficient
implementation of Eckart and quasi-Eckart frame embedding that does not rely on
numerical finite differences.


title: Symmetry-Breaking Zeeman-Coherence Parametric Wave Mixing Magnetometry

abstract:
  The nonlinear magneto-optical effect has significantly impacted modern
society with prolific applications ranging from precision mapping of the
Earth's magnetic field to bio-magnetic sensing. Pioneering works on collisional
spin-exchange effects have led to ultra-high magnetic field detection
sensitivities at the level of $fT/\sqrt{Hz}$ using a single linearly-polarized
probe light field. Here we demonstrate a nonlinear Zeeman-coherence parametric
wave-mixing optical-atomic magnetometer using room temperature rubidium vapor
that results in more than a three-order-of-magnitude optical signal-to-noise
ratio (SNR) enhancement for extremely weak magnetic field sensing. This
unprecedented enhancement was achieved with nearly a two-order-of-magnitude
reduction in laser power while preserving the sensitivity of the widely-used
single-probe beam optical-atomic magnetometry method. This new method opens a
myriad of applications ranging from bio-magnetic imaging to precision
measurement of the magnetic properties of subatomic particles.


title: Network reconstruction from infection cascades

abstract:
  Accessing the network through which a propagation dynamics diffuse is
essential for understanding and controlling it. In a few cases, such
information is available through direct experiments or thanks to the very
nature of propagation data. In a majority of cases however, available
information about the network is indirect and comes from partial observations
of the dynamics, rendering the network reconstruction a fundamental inverse
problem. Here we show that it is possible to reconstruct the whole structure of
an interaction network and to simultaneously infer the complete time course of
activation spreading, relying just on single epoch (i.e. snapshot) or
time-scattered observations of a small number of activity cascades. The method
that we present is built on a Belief Propagation approximation, that has shown
impressive accuracy in a wide variety of relevant cases, and is able to infer
interactions in presence of incomplete time-series data by providing a detailed
modeling of the posterior distribution of trajectories conditioned to the
observations. Furthermore, we show by experiments that the information content
of full cascades is relatively smaller than that of sparse observations or
single snapshots.

categories: physics.soc-ph cond-mat.dis-nn cs.SI q-bio.PE


title: Non-anti-hermitian quaternionic quantum mechanics

abstract:
  The breakdown of Ehrenfest's theorem imposes serious limitations on
quaternionic quantum mechanics (QQM). In order to determine the conditions in
which the theorem is valid, we examined the conservation of the probability
density, the expectation value and the classical limit for a non-anti-hermitian
formulation of QQM. The results also indicated that the non-anti-hermitian
quaternionic theory is related to non-hermitian quantum mechanics, and thus the
physical problems described with both of the theories should be related.


title: The quantum Rabi model: solution and dynamics

abstract:
  This article presents a review of recent developments on various aspects of
the quantum Rabi model. Particular emphasis is given on the exact analytic
solution obtained in terms of confluent Heun functions. The analytic solutions
for various generalisations of the quantum Rabi model are also discussed.
Results are also reviewed on the level statistics and the dynamics of the
quantum Rabi model. The article concludes with an introductory overview of
several experimental realisations of the quantum Rabi model. An outlook towards
future developments is also given.


title: Citation Classification for Behavioral Analysis of a Scientific Field

abstract:
  Citations are an important indicator of the state of a scientific field,
reflecting how authors frame their work, and influencing uptake by future
scholars. However, our understanding of citation behavior has been limited to
small-scale manual citation analysis. We perform the largest behavioral study
of citations to date, analyzing how citations are both framed and taken up by
scholars in one entire field: natural language processing. We introduce a new
dataset of nearly 2,000 citations annotated for function and centrality, and
use it to develop a state-of-the-art classifier and label the entire ACL
Reference Corpus. We then study how citations are framed by authors and use
both papers and online traces to track how citations are followed by readers.
We demonstrate that authors are sensitive to discourse structure and
publication venue when citing, that online readers follow temporal links to
previous and future work rather than methodological links, and that how a paper
cites related work is predictive of its citation count. Finally, we use changes
in citation roles to show that the field of NLP is undergoing a significant
increase in consensus.


title:
Subelliptic Resolvent Estimates for Non-self-adjoint Semiclassical
  Schrodinger Operators

abstract:
  In this paper we prove a subelliptic resolvent estimate for a class of
semiclassical non-self-adjoint Schr\"odinger operators with purely imaginary
potentials when the spectral parameter is in a parabolic neighborhood of the
imaginary axis.


title: Evolution of Protoplanetary Discs with Magnetically Driven Disc Winds

abstract:
  Aims: We investigate the evolution of protoplanetary discs (PPDs hereafter)
with magnetically driven disc winds and viscous heating. Methods: We consider
an initially massive disc with ~0.1 Msun to track the evolution from the early
stage of PPDs. We solve the time evolution of surface density and temperature
by taking into account viscous heating and the loss of the mass and the angular
momentum by the disc winds within the framework of a standard alpha model for
accretion discs. Our model parameters, turbulent viscosity, disc wind mass
loss, and disc wind torque, which are adopted from local magnetohydrodynamical
simulations and constrained by the global energetics of the gravitational
accretion, largely depends on the physical condition of PPDs, particularly on
the evolution of the vertical magnetic flux in weakly ionized PPDs. Results:
Although there are still uncertainties concerning the evolution of the vertical
magnetic flux remaining, surface densities show a large variety, depending on
the combination of these three parameters, some of which are very different
from the surface density expected from the standard accretion. When a PPD is in
a "wind-driven accretion" state with the preserved vertical magnetic field, the
radial dependence of the surface density can be positive in the inner region
<1-10 au. The mass accretion rates are consistent with observations, even in
the very low level of magnetohydrodynamical turbulence. Such a positive radial
slope of the surface density gives a great impact on planet formation because
(i)it inhibits the inward drift or even results in the outward drift of
pebble/boulder-sized solid bodies, and (ii) it also makes the inward type-I
migration of proto-planets slower or even reversed. Conclusions: The variety of
our calculated PPDs should yield a wide variety of exoplanet systems.


title:
Quasi-two-dimensional Bose-Einstein condensation of spin triplets in
  dimerized quantum magnet Ba$_2$CuSi$_2$O$_6$Cl$_2$

abstract:
  We synthesized single crystals of composition Ba$_2$CuSi$_2$O$_6$Cl$_2$ and
investigated its quantum magnetic properties. The crystal structure is closely
related to that of the quasi-two-dimensional (2D) dimerized magnet
BaCuSi$_2$O$_6$ also known as Han purple. Ba$_2$CuSi$_2$O$_6$Cl$_2$ has a
singlet ground state with an excitation gap of ${\Delta}/k_{\rm B}\,{=}\,20.8$
K. The magnetization curves for two different field directions almost perfectly
coincide when normalized by the $g$-factor except for a small jump anomaly for
a magnetic field perpendicular to the $c$ axis. The magnetization curve with a
nonlinear slope above the critical field is in excellent agreement with
exact-diagonalization calculations based on a 2D coupled spin-dimer model.
Individual exchange constants are also evaluated using density functional
theory (DFT). The DFT results demonstrate a 2D exchange network and weak
frustration between interdimer exchange interactions, supported by weak
spin-lattice coupling implied from our magnetostriction data. The
magnetic-field-induced spin ordering in Ba$_2$CuSi$_2$O$_6$Cl$_2$ is described
as the quasi-2D Bose-Einstein condensation of triplets.


title:
Qualitative Framing of Financial Incentives - A Case of Emotion
  Annotation

abstract:
  Online labor platforms, such as the Amazon Mechanical Turk, provide an
effective framework for eliciting responses to judgment tasks. Previous work
has shown that workers respond best to financial incentives, especially to
extra bonuses. However, most of the tested incentives involve describing the
bonus conditions in formulas instead of plain English. We believe that
different incentives given in English (or in qualitative framing) will result
in differences in workers' performance, especially when task difficulties vary.
In this paper, we report the preliminary results of a crowdsourcing experiment
comparing workers' performance using only qualitative framings of financial
incentives. Our results demonstrate a significant increase in workers'
performance using a specific well-formulated qualitative framing inspired by
the Peer Truth Serum. This positive effect is observed only when the difficulty
of the task is high, while when the task is easy there is no difference of
which incentives to use.


title: On the subgroup generated by solutions of Pell's equation

abstract:
  Equivalence classes of solutions of the Diophantine equation $a^2+mb^2=c^2$
form an infinitely generated abelian group $G_m$, where $m$ is a fixed
square-free positive integer. Solutions of Pell's equation $x^2-my^2=1$
generate a subgroup $P_m$ of $G_m$. We prove that $P_m$ and $G_m/P_m$ have
infinite rank for all $m>1$. We also give several examples of $m$ for which
$G_m/P_m$ has nontrivial torsion.


title: Characterizing the structure of protein-protein interaction networks

abstract:
  Network theorists have developed methods to characterize the complex
interactions in natural phenomena. The structure of the network of interactions
between proteins is important in the field of proteomics, and has been subject
to intensive research in recent years, as scientists have become increasingly
capable and interested in describing the underlying structure of interactions
in both normal and pathological biological processes. In this paper, we survey
the graph-theoretic characterization of protein-protein interaction networks
(PINs) in terms of structural features, and discuss its possible applications
in biomedical research. We also perform a brief revision of network theory's
classical literature and discuss modern statistical and computational
techniques to describe the structure of PINs


title:
The role of $a_1(1260)$ in $\pi^- p \to a^-_1(1260) p$ and $\pi^- p \to
  \pi^- \rho^0 p$ reactions near threshold

abstract:
  We report on a theoretical study of the $\pi^- p \to a^-_1(1260) p$ and
$\pi^- p \to \pi^- \rho^0 p$ reactions near threshold within an effective
Lagrangian approach. The production process is described by $t$-channel
$\rho^0$ meson exchange. For the $\pi^- p \to \pi^- \rho^0 p$ reaction, the
final $\pi^- \rho^0$ results from the decay of the $a_1(1260)$ resonance which
is assumed as a dynamically generated state from the $K^* \bar K$ and $\rho
\pi$ coupled channel interactions. We calculate the total cross section of the
$\pi^- p \to a^-_1(1260) p$ reaction. It is shown that, with the coupling
constant of the $a_1(1260)$ to $\rho \pi$ channel obtained from the chiral
unitary theory and a cut off parameter $\Lambda_\rho \sim 1.5$ GeV in the form
factors, the experimental measurement can be reproduced. Furthermore, the total
and differential cross sections of $\pi^- p \to a^-_1(1260) p \to \pi^- \rho^0
p$ reaction are evaluated, and it is expected that our model calculations can
be tested by future experiments. These reactions are important for the study of
the $a_1(1260)$ resonance and would provide further clue for the nature of
$a_1(1260)$ state.


title: Counter-term for the Palatini action of general relativity

abstract:
  In this paper, we analysis the counter-term for the general relativity in the
Palatini framework. The expression is valid for both the null boundary and
non-null boundary. We show that final results coincide with that in
Ref.\cite{pad1} which starts form the Einstein-Hilbert action.


title: Beam test of CSES silicon strip detector module

abstract:
  The silicon-strip tracker of the China Seismo-Electromagnetic Satellite
(CSES) consists of two double-sided silicon strip detectors (DSSDs) which
provide incident particle tracking information. The low-noise analog ASIC VA140
was used in this study for DSSD signal readout. A beam test on the DSSD module
was performed at the Beijing Test Beam Facility of the Beijing Electron
Positron Collider (BEPC) using a 400~800 MeV/c proton beam. The pedestal
analysis results, RMSE noise, gain correction, and particle incident position
reconstruction of the DSSD module are presented.


title:
Controlling effective dimensionality and competition between spin liquid
  and chiral orders by new multiorbital effects in $S=\frac{1}{2}$ pyrochlore
  oxides

abstract:
  In frustrated systems, some or many states are competed due to frustration of
exchange interactions, and this competition often results in exotic states,
such as spin liquid and chiral orders. We consider a pyrochlore oxide, a
three-dimensional frustrated system, and study its $S=\frac{1}{2}$ effective
model, consisting of the Heisenberg-type and Dzyaloshinsky-Moriya-type
superexchange interactions between the nearest-neighbor transition-metal ions.
We show that by using new multiorbital effects of the $t_{2g}$ orbitals on
coefficients of those interactions, we can change the effective dimensionality
from three-dimensional to two-dimensional, and control the competition between
chiral orders and spin liquid. We also show that the new multiorbital effects
are vital to stabilize three-in-one-out chiral order, distorted
four-in-four-out chiral order, and distorted three-in-one-out chiral order, and
can be used to hold macroscopic degeneracy, resulting in the spin liquid, even
with the finite Dzyaloshinsky-Moriya interactions. Those results open up new
multiorbital physics in spin systems, and make the essential step for the
realistic mechanism for the spin liquid in pyrochlore oxides.