title:
The "Horse'' Inside: Seeking Causes Behind the Behaviours of Music
  Content Analysis Systems

abstract:
  Building systems that possess the sensitivity and intelligence to identify
and describe high-level attributes in music audio signals continues to be an
elusive goal, but one that surely has broad and deep implications for a wide
variety of applications. Hundreds of papers have so far been published toward
this goal, and great progress appears to have been made. Some systems produce
remarkable accuracies at recognising high-level semantic concepts, such as
music style, genre and mood. However, it might be that these numbers do not
mean what they seem. In this paper, we take a state-of-the-art music content
analysis system and investigate what causes it to achieve exceptionally high
performance in a benchmark music audio dataset. We dissect the system to
understand its operation, determine its sensitivities and limitations, and
predict the kinds of knowledge it could and could not possess about music. We
perform a series of experiments to illuminate what the system has actually
learned to do, and to what extent it is performing the intended music listening
task. Our results demonstrate how the initial manifestation of music
intelligence in this state-of-the-art can be deceptive. Our work provides
constructive directions toward developing music content analysis systems that
can address the music information and creation needs of real-world users.


title: Stabilization of second order nonlinear equations with variable delay

abstract:
  For a wide class of second order nonlinear non-autonomous models, we
illustrate that combining proportional state control with the feedback that is
proportional to the derivative of the chaotic signal, allows to stabilize
unstable motions of the system. The delays are variable, which leads to more
flexible controls permitting delay perturbations; only delay bounds are
significant for stabilization by a delayed control. The results are applied to
the sunflower equation which has an infinite number of equilibrium points.


title:
An infinite class of exact static anisotropic spheres that break the
  Buchdal bound

abstract:
  An infinite class of exact static anisotropic spheres is developed. All
members of the class satisfy (i) regularity (meaning no singularities), and in
particular at the origin, (ii) positive but monotone decreasing energy density
($\rho(r)$), radial pressure ($p(r)$), and tangential pressure ($P(r)$), (iii)
a finite value of $r=R$ such that $p(R)=0$ defining the boundary surface onto
vacuum, (iv) $p \leq \rho$, and (v) $p + 2 P=3 \rho$. All standard energy
conditions are satisfied except for the dominant energy condition which has an
innocuous violation by the tangential stress since $\rho \leq P$ by
construction. An infinite number of the solutions violate the Buchdal bound.


title: Infrared behavior of dipolar Bose systems at low temperatures

abstract:
  We rigorously discuss the infrared behavior of the uniform three dimensional
dipolar Bose systems. In particular, it is shown that low-temperature physics
of the system is controlled by two parameters, namely isothermal
compressibility and intensity of the dipole-dipole interaction. By using
hydrodynamic approach we calculate the spectrum and damping of low-lying
excitations and analyze infrared behavior of the one-particle Green's function.
The low-temperature corrections to the anisotropic superfluid density as well
as condensate depletion are found. Additionally we derive equations of the
two-fluid hydrodynamics for dipolar Bose systems and calculate velocities of
first and second sound.


title: A Minimum Spanning Tree Representation of Anime Similarities

abstract:
  In this work, a new way to represent Japanese animation (anime) is presented.
We applied a minimum spanning tree to show the relation between anime. The
distance between anime is calculated through three similarity measurements,
namely crew, score histogram, and topic similarities. Finally, the centralities
are also computed to reveal the most significance anime. The result shows that
the minimum spanning tree can be used to determine the similarity anime.
Furthermore, by using centralities calculation, we found some anime that are
significant to others.


title:
Multidimensional van der Corput sets and small fractional parts of
  polynomials

abstract:
  We establish Diophantine inequalities for the fractional parts of generalized
polynomials $f$, in particular for sequences $\nu(n)=\lfloor n^c\rfloor+n^k$
with $c>1$ a non-integral real number and $k\in\mathbb{N}$, as well as for
$\nu(p)$ where $p$ runs through all prime numbers. This is related to classical
work of Heilbronn and to recent results of Bergelson \textit{et al.}


title: Phonon Anharmonicity in Bulk $T_d$-MoTe$_2$

abstract:
  We examine anharmonic contributions to the optical phonon modes in bulk
$T_d$-MoTe$_2$ through temperature-dependent Raman spectroscopy. At
temperatures ranging from 100 K to 200 K, we find that all modes redshift
linearly with temperature in agreement with the Gr\"{u}neisen model. However,
below 100 K we observe nonlinear temperature-dependent frequency shifts in some
modes. We demonstrate that this anharmonic behavior is consistent with the
decay of an optical phonon into multiple acoustic phonons. Furthermore, the
highest frequency Raman modes show large changes in intensity and linewidth
near $T\approx 250$ K that correlate well with the $T_d \to 1T^\prime$
structural phase transition. These results suggest that phonon-phonon
interactions can dominate anharmonic contributions at low temperatures in bulk
$T_d$-MoTe$_2$, an experimental regime that is currently receiving attention in
efforts to understand Weyl semimetals.


title: Augmenting momentum resolution with well tuned probability distributions

abstract:
  The realistic probability distributions of a previous article are applied to
the reconstruction of tracks in constant magnetic field. The complete forms and
their schematic approximations produce excellent momentum estimations,
drastically better than standard fits. A simplified derivation of one of our
probability distributions is illustrated. The momentum reconstructions are
compared with standard fits (least squares) with two different position
algorithms: the eta-algorithm and the two-strip center of gravity. The quality
of our results are expressed as the increase of the magnetic field and
signal-to-noise ratio that overlap the standard fit reconstructions with ours
best distributions. The data and the simulations are tuned on the tracker of a
running experiment and its double sided microstrip detectors, here each
detector side is simulated to measure the magnetic bending. To overlap with our
best distributions, the magnetic field must be increased by a factor 1.5 for
the least squares based on the eta-algorithm and 1.8 for the two-strip center
of gravity for the low noise side, and 1.8 and 2.0 for the high noise side. The
signal-to-noise ratio must be increased by 1.6 for the low noise side and 2.2
for the high noise side (eta-algorithms). The fits, built on the positioning
with the center of gravity, are not modified by a reduction of the
signal-to-noise ratio.}


title: Microscope Project for Undergraduate Laboratories

abstract:
  Optics is an important subfield of physics required for instrument design and
used in a variety of other disciplines, including materials science, physics,
and life sciences such as developmental biology and cell biology. It is
important to educate students from a variety of disciplines and backgrounds in
the basics of optics in order to train the next generation of interdisciplinary
researchers and instrumentalists who will push the boundaries of discovery. In
this paper, we present an experimental system developed to teach students in
the basics of geometric optics, including ray and wave optics. The students
learn these concepts through designing, building, and testing a home-built
light microscope made from component parts. We describe the experimental
equipment and basic measurements students can perform to learn principles,
technique, accuracy, and resolution of measurement. Students find the
magnification and test the resolution of the microscope system they build. The
system is open and versatile to allow advanced building projects, such as
epi-fluorescence, total internal reflection fluorescence, and optical trapping.
We have used this equipment in an optics course, an advanced laboratory course,
and graduate-level training modules.

categories: physics.ed-ph physics.bio-ph physics.ins-det physics.optics q-bio.QM


title:
Giant lobes of Centaurus A as seen in radio and gamma-ray images
  obtained with the Fermi-LAT and Planck satellites

abstract:
  The {\gamma}-ray data of Fermi-LAT on the giant lobes of Centaurus A are
analysed together with the high frequency radio data obtained with the Planck
satellite. The large {\gamma}-ray photon statistics, accumulated during seven
years of observations, and the recently updated Fermi collaboration software
tools allow substantial extension of the detected {\gamma}-ray emission towards
higher energy, up to 30 GeV, and lower energy, down to 60 MeV. Moreover, the
new {\gamma}-ray data allow us to explore the spatial features of {\gamma}-ray
emission of the lobes. For the north lobe, we confirm, with higher statistical
significance, our earlier finding on the extension of {\gamma}-ray emission
beyond the radio image. Moreover, the new analysis reveals significant spatial
variation of {\gamma}-ray spectra from both lobes. On the other hand, the
Planck observations at microwave frequencies contain important information on
spectra of synchrotron emission in the cutoff region, and thus allow
model-independent derivation of the strength of the magnetic field and the
distribution of relativistic electrons based on the combined {\gamma}-ray and
radio data. The interpretation of multiwavelength spectral energy distributions
(SEDs) of the lobes within a pure leptonic model requires strong enhancement of
the magnetic field at the edge of the south lobe. Alternatively, a more
complex, leptonic-hadronic model of the {\gamma}-ray emission, postulating a
non-negligible contribution of the {\pi}^0 -decay component at highest
energies, can explain the {\gamma}-ray data with a rather homogeneous
distribution of the magnetic field over the giant lobes.


title:
Demonstration of a white beam far-field neutron interferometer for
  spatially resolved small angle neutron scattering

abstract:
  We provide the first demonstration that a neutron far-field interferometer
can be employed to measure the microstructure of a sample. The interferometer
is based on the moir\'e pattern of two phase modulating gratings which was
previously realized in hard x-ray and visible light experiments. The
autocorrelation length of this interferometer, and hence the microstructure
length scale that is probed, is proportional to the grating spacing and the
neutron wavelength, and can be varied over several orders of magnitude for one
pair of gratings. We compare our measurements of the change in visibility from
monodisperse samples with calculations which show reasonable agreement. The
potential advantages of a far-field neutron interferometer include high fringe
visibility in a polychromatic beam (over 30 %), no requirement for an absorbing
grating to resolve the interference fringes, and the ability to measure the
microstructure in the length scale range of 100 nm to 10 \mum by varying either
the grating spacing or neutron wavelength with a broad wavelength range and
single set of gratings.


title: Optimizing quantization for Lasso recovery

abstract:
  This letter is focused on quantized Compressed Sensing, assuming that Lasso
is used for signal estimation. Leveraging recent work, we provide a framework
to optimize the quantization function and show that the recovered signal
converges to the actual signal at a quadratic rate as a function of the
quantization level. We show that when the number of observations is high, this
method of quantization gives a significantly better recovery rate than standard
Lloyd-Max quantization. We support our theoretical analysis with numerical
simulations.


title:
Spin dynamical phase and anti-resonance in a strongly coupled
  magnon-photon system

abstract:
  We experimentally studied a strongly coupled magnon-photon system via
microwave transmission measurements. An anti-resonance, i.e. the suppression of
the microwave transmission, is observed, indicating a relative phase change
between the magnon response and the driving microwave field. We show that this
anti-resonance feature can be used to interpret the phase evolution of the
coupled magnon-microwave system and apply this technique to reveal the phase
evolution of magnon dark modes. Our work provides a standard procedure for the
phase analysis of strongly coupled systems, enabling the phase characterization
of each subsystem, and can be generally applied to other strongly coupled
systems.


title: Testing for New Physics: Neutrinos and the Primordial Power Spectrum

abstract:
  We test the sensitivity of neutrino parameter constraints from combinations
of CMB and LSS data sets to the assumed form of the primordial power spectrum
(PPS) using Bayesian model selection. Significantly, none of the tested
combinations, including recent high-precision local measurements of
$\mathrm{H}_0$ and cluster abundances, indicate a signal for massive neutrinos
or extra relativistic degrees of freedom. For PPS models with a large, but
fixed number of degrees of freedom, neutrino parameter constraints do not
change significantly if the location of any features in the PPS are allowed to
vary, although neutrino constraints are more sensitive to PPS features if they
are known a priori to exist at fixed intervals in $\log k$. Although there is
no support for a non-standard neutrino sector from constraints on both neutrino
mass and relativistic energy density, we see surprisingly strong evidence for
features in the PPS when it is constrained with data from Planck 2015, SZ
cluster counts, and recent high-precision local measurements of $\mathrm{H}_0$.
Conversely combining Planck with matter power spectrum and BAO measurements
yields a much weaker constraint. Given that this result is sensitive to the
choice of data this tension between SZ cluster counts, Planck and
$\mathrm{H}_0$ measurements is likely an indication of unmodeled systematic
bias that mimics PPS features, rather than new physics in the PPS or neutrino
sector.


title: THz Time-Domain Spectroscopy of Mixed CO2-CH3OH Interstellar Ice Analogs

abstract:
  The icy mantles of interstellar dust grains are the birthplaces of the
primordial prebiotic molecular inventory that may eventually seed nascent solar
systems and the planets and planetesimals that form therein. Here, we present a
study of two of the most abundant species in these ices after water: carbon
dioxide (CO2) and methanol (CH3OH) using TeraHertz (THz) time-domain
spectroscopy and mid-infrared spectroscopy. We study pure and mixed-ices of
these species, and demonstrate the power of the THz region of the spectrum to
elucidate the long-range structure (i.e. crystalline versus amorphous) of the
ice, the degree of segregation of these species within the ice, and the thermal
history of the species within the ice. Finally, we comment on the utility of
the THz transitions arising from these ices for use in astronomical
observations of interstellar ices.


title:
Consistency and convergence rate of phylogenetic inference via
  regularization

abstract:
  It is common in phylogenetics to have some, perhaps partial, information
about the overall evolutionary tree of a group of organisms and wish to find an
evolutionary tree of a specific gene for those organisms. There may not be
enough information in the gene sequences alone to accurately reconstruct the
correct "gene tree." Although the gene tree may deviate from the "species tree"
due to a variety of genetic processes, in the absence of evidence to the
contrary it is parsimonious to assume that they agree. A common statistical
approach in these situations is to develop a likelihood penalty to incorporate
such additional information. Recent studies using simulation and empirical data
suggest that a likelihood penalty quantifying concordance with a species tree
can significantly improve the accuracy of gene tree reconstruction compared to
using sequence data alone. However, the consistency of such an approach has not
yet been established, nor have convergence rates been bounded. Because
phylogenetics is a non-standard inference problem, the standard theory does not
apply. In this paper, we propose a penalized maximum likelihood estimator for
gene tree reconstruction, where the penalty is the square of the
Billera-Holmes-Vogtmann geodesic distance from the gene tree to the species
tree. We prove that this method is consistent, and derive its convergence rate
for estimating the discrete gene tree structure and continuous edge lengths
(representing the amount of evolution that has occurred on that branch)
simultaneously. We find that the regularized estimator is "adaptive fast
converging," meaning that it can reconstruct all edges of length greater than
any given threshold from gene sequences of polynomial length. Our method does
not require the species tree to be known exactly; in fact, our asymptotic
theory holds for any such guide tree.


title: Network as a Service: The New Vista of Opportunities

abstract:
  The networking industry, compared to the compute industry, has been slow in
evolving from a closed ecosystem with limited abstractions to a more open
ecosystem with well-defined sophisticated high level abstractions. This has
resulted in an ossified Internet architecture that inhibits innovation and is
unnecessarily complex. Fortunately, there has been an exciting flux of rapid
developments in networking in recent times with prominent trends emerging that
have brought us to the cusp of a major paradigm shift. In particular, the
emergence of technologies such as cloud computing, software defined networking
(SDN), and network virtualization are driving a new vision of `networking as a
service' (NaaS) in which networks are managed flexibly and efficiently cloud
computing style. These technologies promise to both facilitate architectural
and technological innovation while also simplifying commissioning,
orchestration, and composition of network services. In this article, we
introduce our readers to these technologies. In the coming few years, the
trends of cloud computing, SDN, and network virtualization will further
strengthen each other's value proposition symbiotically and NaaS will
increasingly become the dominant mode of commissioning new networks.


title: Tapered Simplified Modal Method for Analysis of Non-rectangular Gratings

abstract:
  The Simplified Modal Method (SMM) provides a quick and intuitive way to
analyze the performance of gratings of rectangular shapes. For non-rectangular
shapes, a version of SMM has been developed, but it applies only to the
Littrow-mounting incidence case and it neglects reflection. Here, we use the
theory of mode-coupling in a tapered waveguide to improve SMM so that it
applies to non-rectangular gratings at arbitrary angles of incidence. Moreover,
this new 'Tapered Simplified Modal Method' (TSMM) allows us to properly account
for reflected light. We present here the analytical development of the theory
and numerical simulations, demonstrating the validity of the method.


title: Procrastination with variable present bias

abstract:
  Individuals working towards a goal often exhibit time inconsistent behavior,
making plans and then failing to follow through. One well-known model of such
behavioral anomalies is present-bias discounting: individuals over-weight
present costs by a bias factor. This model explains many time-inconsistent
behaviors, but can make stark predictions in many settings: individuals either
follow the most efficient plan for reaching their goal or procrastinate
indefinitely.
  We propose a modification in which the present-bias parameter can vary over
time, drawn independently each step from a fixed distribution. Following
Kleinberg and Oren (2014), we use a weighted task graph to model task planning,
and measure the cost of procrastination as the relative expected cost of the
chosen path versus the optimal path. We use a novel connection to optimal
pricing theory to describe the structure of the worst-case task graph for any
present-bias distribution. We then leverage this structure to derive conditions
on the bias distribution under which the worst-case ratio is exponential (in
time) or constant. We also examine conditions on the task graph that lead to
improved procrastination ratios: graphs with a uniformly bounded distance to
the goal, and graphs in which the distance to the goal monotonically decreases
on any path.


title:
Neural computation from first principles: Using the maximum entropy
  method to obtain an optimal bits-per-joule neuron

abstract:
  Optimization results are one method for understanding neural computation from
Nature's perspective and for defining the physical limits on neuron-like
engineering. Earlier work looks at individual properties or performance
criteria and occasionally a combination of two, such as energy and information.
Here we make use of Jaynes' maximum entropy method and combine a larger set of
constraints, possibly dimensionally distinct, each expressible as an
expectation. The method identifies a likelihood-function and a sufficient
statistic arising from each such optimization. This likelihood is a
first-hitting time distribution in the exponential class. Particular constraint
sets are identified that, from an optimal inference perspective, justify
earlier neurocomputational models. Interactions between constraints, mediated
through the inferred likelihood, restrict constraint-set parameterizations,
e.g., the energy-budget limits estimation performance which, in turn, matches
an axonal communication constraint. Such linkages are, for biologists,
experimental predictions of the method. In addition to the related likelihood,
at least one type of constraint set implies marginal distributions, and in this
case, a Shannon bits/joule statement arises.


title:
Finite subgroups of simple algebraic groups with irreducible
  centralizers

abstract:
  We determine all finite subgroups of simple algebraic groups that have
irreducible centralizers - that is, centralizers whose connected component does
not lie in a parabolic subgroup.


title:
Impact of Rocks and Minerals on Underground Magneto-Inductive
  Communication and Localization

abstract:
  In this paper, we analyze the effect of different underground materials on
very-low and low frequency magnetic fields used in the contexts of
magneto-inductive localization and communication applications, respectively. We
calculate the attenuation that these magnetic fields are subject to while
passing through most common rocks and minerals. Knowing the attenuation
properties is crucial in the design of underground magneto-inductive
communication systems. In addition, we provide means to predict the distortions
in the magnetic field that impair localization systems. The proposed work
offers basic design guidelines for communication and localization systems in
terms of channel path-loss, operation frequencies and bandwidth. For the sake
of the reproducibility of the results, we provide the raw data and processing
source code to be used by the two research communities.


title: The Effects of Latency Penalties in Evaluating Push Notification Systems

abstract:
  We examine the effects of different latency penalties in the evaluation of
push notification systems, as operationalized in the TREC 2015 Microblog track
evaluation. The purpose of this study is to inform the design of metrics for
the TREC 2016 Real-Time Summarization track, which is largely modeled after the
TREC 2015 evaluation design.


title: Exploring the Jet Multiplicity in the 750 GeV Diphoton Excess

abstract:
  The recent diphoton excess at the LHC has been explained tentatively by a
Standard Model (SM) singlet scalar of 750 GeV in mass, in the association of
heavy particles with SM gauge charges. These new particles with various SM
gauge charges induce loop-level couplings of the new scalar to $WW$, $ZZ$,
$Z\gamma$, $\gamma\gamma$, and $gg$. We show that the strength of the couplings
to the gauge bosons also determines the production mechanism of the scalar
particle via $WW,\, ZZ,\, Z\gamma,\, \gamma\gamma,\, gg$ fusion which leads to
individually distinguishable jet distributions in the final state where the
statistics will be improved in the ongoing run. The number of jets and the
leading jet's transverse momentum distribution in the excess region of the
diphoton signal can be used to determine the coupling of the scalar to the
gauge bosons arising from the protons which subsequently determine the charges
of the heavy particles that arise from various well-motivated models.


title:
Velocity Statistics in Holographic Fluids: Magnetized Quark-Gluon Plasma
  and Superfluid Flow

abstract:
  We study the velocity statistics distribution of an external heavy particle
in holographic fluids. We argue that when the dual supergravity background has
a finite temperature horizon the velocity statistics goes generically as $1/v$,
compatible with the jet-quenching intuition from the quark-gluon plasma. A
careful analysis of the behavior of the classical string whose apparent
worldsheet horizon deviates from the background horizon reveals that other
regimes are possible. We numerically discuss two cases: the magnetized
quark-gluon plasma and a model of superfluid flow. We explore a range of
parameters in these top-down supergravity solutions including, respectively,
the magnetic field and the superfluid velocity. We determine that the velocity
statistics goes largely as $1/v$, however, as we leave the non-relativistic
regime we observe some deviations.


title: Inequivalence of Correlation-based Measures of Non-Markovianity

abstract:
  We conclusively show that the entanglement- and the mutual information-based
measures of quantum non-Markovianity are inequivalent. To this aim, we first
analytically solve the optimization problem in the definition of the
entanglement-based measure for a two-level system. We demonstrate that the
optimal initial bipartite state of the open system and the ancillary is always
given by one of the Bell states for any one qubit dynamics. On top of this
result, we present an explicit example dynamics where memory effects emerge
according to the mutual information-based measure, even though the time
evolution remains memoryless with respect to the entanglement-based measure.
Finally, we explain this disagreement between the two measures in terms of the
information dynamics of the open system, exploring the accessible and
inaccessible parts of information.


title: Microwave-free magnetometry with nitrogen-vacancy centers in diamond

abstract:
  We use magnetic-field-dependent features in the photoluminescence of
negatively charged nitrogen-vacancy centers to measure magnetic fields without
the use of microwaves. In particular, we present a magnetometer based on the
level anti-crossing in the triplet ground state at 102.4 mT with a demonstrated
noise floor of 6 nT/$\sqrt{\text{Hz}}$, limited by the intensity noise of the
laser and the performance of the background-field power supply. The technique
presented here can be useful in applications where the sensor is placed closed
to conductive materials, e.g. magnetic induction tomography or magnetic field
mapping, and in remote-sensing applications since principally no electrical
access is needed.


title:
Modeling the dynamics of human brain activity with recurrent neural
  networks

abstract:
  Encoding models are used for predicting brain activity in response to sensory
stimuli with the objective of elucidating how sensory information is
represented in the brain. Encoding models typically comprise a nonlinear
transformation of stimuli to features (feature model) and a linear
transformation of features to responses (response model). While there has been
extensive work on developing better feature models, the work on developing
better response models has been rather limited. Here, we investigate the extent
to which recurrent neural network models can use their internal memories for
nonlinear processing of arbitrary feature sequences to predict feature-evoked
response sequences as measured by functional magnetic resonance imaging. We
show that the proposed recurrent neural network models can significantly
outperform established response models by accurately estimating long-term
dependencies that drive hemodynamic responses. The results open a new window
into modeling the dynamics of brain activity in response to sensory stimuli.


title:
Long term evolution of planetary systems with a terrestrial planet and a
  giant planet

abstract:
  We study the long term orbital evolution of a terrestrial planet under the
gravitational perturbations of a giant planet. In particular, we are interested
in situations where the two planets are in the same plane and are relatively
close. We examine both possible configurations: the giant planet orbit being
either outside or inside the orbit of the smaller planet. The perturbing
potential is expanded to high orders and an analytical solution of the
terrestrial planetary orbit is derived. The analytical estimates are then
compared against results from the numerical integration of the full equations
of motion and we find that the analytical solution works reasonably well. An
interesting finding is that the new analytical estimates improve greatly the
predictions for the timescales of the orbital evolution of the terrestrial
planet compared to an octupole order expansion. Finally, we briefly discuss
possible applications of the analytical estimates in astrophysical problems.


title: Convolutional Sketch Inversion

abstract:
  In this paper, we use deep neural networks for inverting face sketches to
synthesize photorealistic face images. We first construct a semi-simulated
dataset containing a very large number of computer-generated face sketches with
different styles and corresponding face images by expanding existing
unconstrained face data sets. We then train models achieving state-of-the-art
results on both computer-generated sketches and hand-drawn sketches by
leveraging recent advances in deep learning such as batch normalization, deep
residual learning, perceptual losses and stochastic optimization in combination
with our new dataset. We finally demonstrate potential applications of our
models in fine arts and forensic arts. In contrast to existing patch-based
approaches, our deep-neural-network-based approach can be used for synthesizing
photorealistic face images by inverting face sketches in the wild.


title:
PTF12os and iPTF13bvn. Two stripped-envelope supernovae from low-mass
  progenitors in NGC 5806

abstract:
  We investigate two stripped-envelope supernovae (SNe) discovered in the
nearby galaxy NGC 5806 by the (i)PTF. These SNe, designated PTF12os/SN 2012P
and iPTF13bvn, exploded at a similar distance from the host-galaxy center. We
classify PTF12os as a Type IIb SN based on our spectral sequence; iPTF13bvn has
previously been classified as Type Ib having a likely progenitor with zero age
main sequence (ZAMS) mass below ~17 solar masses. Our main objective is to
constrain the explosion parameters of iPTF12os and iPTF13bvn, and to put
constraints on the SN progenitors.
  We present comprehensive datasets on the SNe, and introduce a new
reference-subtraction pipeline (FPipe) currently in use by the iPTF. We perform
a detailed study of the light curves (LCs) and spectral evolution of the SNe.
The bolometric LCs are modeled using the hydrodynamical code HYDE. We use
nebular models and late-time spectra to constrain the ZAMS mass of the
progenitors. We perform image registration of ground-based images of PTF12os to
archival HST images of NGC 5806 to identify a potential progenitor candidate.
  Our nebular spectra of iPTF13bvn indicate a low ZAMS mass of ~12 solar masses
for the progenitor. The late-time spectra of PTF12os are consistent with a ZAMS
mass of ~15 solar masses. We successfully identify a progenitor candidate to
PTF12os using archival HST images. This source is consistent with being a
cluster of massive stars. Our hydrodynamical modeling suggests that the
progenitor of PTF12os had a compact He core with a mass of 3.25 solar masses,
and that 0.063 solar masses of strongly mixed 56Ni was synthesized. Spectral
comparisons to the Type IIb SN 2011dh indicate that the progenitor of PTF12os
was surrounded by a hydrogen envelope with a mass lower than 0.02 solar masses.
We also find tentative evidence that the progenitor of iPTF13bvn could have
been surrounded by a small amount of hydrogen.


title:
On the Global Hadamard form for the Green Function in Schwarzschild
  space-time

abstract:
  The retarded Green function of a wave equation on a 4-dimensional curved
background space-time is a (generalized) function of two space-time points and
diverges when these are connected by a null geodesic. The Hadamard form makes
explicit the form of this divergence but only when one of the points is in a
normal neighbourhood of the other point. In this paper we derive a global in
time representation for the retarded Green function for a scalar field in
Schwarzschild space-time which makes explicit its complete singularity
structure. We interpret this representation as a sum of Hadamard forms, the
summation being taken over the number of times the null wavefront has passed
through a caustic point. Our representation is valid everywhere except in a
neighbourhood of caustic points. We deal with these points by providing a
separate representation for the Green function which makes explicit its
(different) singularity structure specifically at caustics.


title:
Convergence Rate for Spectral Distribution of Addition of Random
  Matrices

abstract:
  Let $A$ and $B$ be two $N$ by $N$ deterministic Hermitian matrices and let
$U$ be an $N$ by $N$ Haar distributed unitary matrix. It is well known that the
spectral distribution of the sum $H=A+UBU^*$ converges weakly to the free
additive convolution of the spectral distributions of $A$ and $B$, as $N$ tends
to infinity. We establish the optimal convergence rate ${\frac{1}{N}}$ in the
bulk of the spectrum.


title: Efficient Robust Proper Learning of Log-concave Distributions

abstract:
  We study the {\em robust proper learning} of univariate log-concave
distributions (over continuous and discrete domains). Given a set of samples
drawn from an unknown target distribution, we want to compute a log-concave
hypothesis distribution that is as close as possible to the target, in total
variation distance. In this work, we give the first computationally efficient
algorithm for this learning problem. Our algorithm achieves the
information-theoretically optimal sample size (up to a constant factor), runs
in polynomial time, and is robust to model misspecification with nearly-optimal
error guarantees.
  Specifically, we give an algorithm that, on input $n=O(1/\eps^{5/2})$ samples
from an unknown distribution $f$, runs in time $\widetilde{O}(n^{8/5})$, and
outputs a log-concave hypothesis $h$ that (with high probability) satisfies
$\dtv(h, f) = O(\opt)+\eps$, where $\opt$ is the minimum total variation
distance between $f$ and the class of log-concave distributions. Our approach
to the robust proper learning problem is quite flexible and may be applicable
to many other univariate distribution families.


title:
Localized deformation for initial data sets with the dominant energy
  condition

abstract:
  We consider localized deformation for initial data sets of the Einstein field
equations with the dominant energy condition. Deformation results with the weak
inequality need to be handled delicately. We introduce a modified constraint
operator to absorb the first order change of the metric in the dominant energy
condition. By establishing the local surjectivity theorem, we can promote the
dominant energy condition to the strict inequality by compactly supported
variations and obtain new gluing results with the dominant energy condition.
The proof of local surjectivity is a modification of the earlier work for the
usual constraint map by the first named author and R. Schoen and by P.
Chru\'sciel and E. Delay, with some refined analysis.


title: Phase response curves for models of earthquake fault dynamics

abstract:
  We systematically study effects of external perturbations on models
describing earthquake fault dynamics. The latter are based on the framework of
the Burridge-Knopoff spring-block system, including the cases of a simple
mono-block fault, as well as the paradigmatic complex faults made up of two
identical or distinct blocks. The blocks exhibit relaxation oscillations, which
are representative for the stick-slip behavior typical for earthquake dynamics.
Our analysis is carried out by determining the phase response curves of first
and second order. For a mono-block fault, we consider the impact of a single
and two successive pulse perturbations, further demonstrating how the profile
of phase response curves depends on the fault parameters. For a homogeneous
two-block fault, our focus is on the scenario where each of the blocks is
influenced by a single pulse, whereas for heterogeneous faults, we analyze how
the response of the system depends on whether the stimulus is applied to the
block having a shorter or a longer oscillation period.


title: Factorization and dispersion relations for radiative leptonic $B$ decay

abstract:
  Applying the dispersion approach we compute perturbative QCD corrections to
the power suppressed soft contribution of $B \to \gamma \ell \nu$ at leading
twist. QCD factorization for the $B \to \gamma^{\ast}$ form factors is
demonstrated explicitly for the hard-collinear transverse polarized photon at
one loop, with the aid of the method of regions. While the one-loop hard
function is identical to the matching coefficient of the QCD weak current $\bar
u \, \gamma_{\mu \perp} \, (1- \gamma_5) \, b$ in soft-collinear effective
theory, the jet function from integrating out the hard-collinear fluctuations
differs from the corresponding one entering the factorization formula of $B \to
\gamma \ell \nu$. Furthermore, we evaluate the sub-leading power contribution
to the $B \to \gamma$ form factors from the three-particle $B$-meson
distribution amplitudes (DAs) at tree level. The soft contribution to the $B
\to \gamma$ form factors from the three-particle $B$-meson DAs is shown to be
of the same power compared with the corresponding hard correction, in contrast
to the two-particle counterparts. Numerically the next-to-leading-order QCD
correction to the soft two-particle contribution in $B \to \gamma$ form factors
will induce an approximately $\left (10 \sim 20 \right) \%$ shift to the
tree-level contribution at $\lambda_B(\mu_0)=354 \, {\rm MeV}$. Albeit of power
suppression parametrically, the soft two-particle correction can decrease the
leading power predictions for the $B \to \gamma$ form factors by an amount of
$\left (10 \sim 30 \right) \%$ with the same value of $\lambda_B(\mu_0)$.
Employing the phenomenological model of the three-particle $B$-meson DAs
inspired by a QCD sum rule analysis, the three-particle contribution to the $B
\to \gamma$ form factors is predicted to be of ${\cal O} (1 \%)$, at leading
order in $\alpha_s$, with the default theory inputs.


title: Counterfactual quantum erasure: spooky action without entanglement

abstract:
  We combine the eyebrow-raising quantum phenomena of erasure and
counterfactuality for the first time, proposing a simple yet unusual quantum
eraser: A distant Bob can decide to erase which-path information from Alice's
photon, dramatically restoring interference, without previously-shared
entanglement, and without Alice's photon ever leaving her lab.


title: Breaking the superfluid speed limit

abstract:
  Coherent condensates appear as emergent phenomena in many systems, sharing
the characteristic feature of an energy gap separating the lowest excitations
from the condensate ground state. This implies that a scattering object, moving
through the system with high enough velocity for the excitation spectrum in the
scatter frame to become gapless, can create excitations at no energy cost,
initiating the breakdown of the condensate. This limit is the well-known Landau
velocity. While, for the neutral Fermionic superfluid 3He-B in the T=0 limit,
flow around an oscillating body displays a very clear critical velocity for the
onset of dissipation, here we show that for uniform linear motion there is no
discontinuity whatsoever in the dissipation as the Landau critical velocity is
passed and exceeded. Since the Landau velocity is such a pillar of our
understanding of superfluidity, this is a considerable surprise, with
implications for the understanding of the dissipative effects of moving objects
in all coherent condensate systems.


title: Decay of photon with high as well as low energy

abstract:
  The decay of photon by the influence of magnetic field is considered. It is
shown here that if the photon energy is grater than 1 MeV then photon can decay
electron positron pair, but if it remains below 1 MeV then photon decays into
neutrino antineutrino pair. The decay rates for both of the processes are
calculated. All possible Feynman diagrams are taken into account to construct
the matrix element for either of the processes. In the second process all three
type of neutrinos are considered. The significance of these processes are
discussed briefly.


title: Eigenvalue problem in a solid with many inclusions: asymptotic analysis

abstract:
  We construct the asymptotic approximation to the first eigenvalue and
corresponding eigensolution of Laplace's operator inside a domain containing a
cloud of small rigid inclusions. The separation of the small inclusions is
characterised by a small parameter which is much larger compared with the
nominal size of inclusions. Remainder estimates for the approximations to the
first eigenvalue and associated eigenfield are presented. Numerical
illustrations are given to demonstrate the efficiency of the asymptotic
approach compared to conventional numerical techniques, such as the finite
element method, for three-dimensional solids containing clusters of small
inclusions.


title: Symmetries of quantum space-time in 3 dimensions

abstract:
  By applying loop quantum gravity techniques to 3D gravity with a positive
cosmological constant $\Lambda$, we show how the local gauge symmetry of the
theory, encoded in the constraint algebra, acquires the quantum group structure
of $so_q(4)$, with $ q = \exp{(i\hbar \sqrt{\Lambda}/2\kappa)}$. By means of an
Inonu-Wigner contraction of the quantum group bi-algebra, keeping $\kappa$
finite, we obtain the kappa-Poincar\'e algebra of the flat quantum space-time
symmetries.


title:
The Horizon-AGN simulation: morphological diversity of galaxies promoted
  by AGN feedback

abstract:
  The interplay between cosmic gas accretion on to galaxies and galaxy mergers
drives the observed morphological diversity of galaxies. By comparing the
state-of-the-art hydrodynamical cosmological simulations Horizon-AGN and
Horizon-noAGN, we unambiguously identify the critical role of active galactic
nuclei (AGN) in setting up the correct galaxy morphology for the massive end of
the population. With AGN feedback, typical kinematic and morpho-metric
properties of galaxy populations as well as the galaxy-halo mass relation are
in much better agreement with observations. Only AGN feedback allows massive
galaxies at the centre of groups and clusters to become ellipticals, while
without AGN feedback those galaxies reform discs. It is the merger-enhanced AGN
activity that is able to freeze the morphological type of the post-merger
remnant by durably quenching its quiescent star formation. Hence morphology is
shown to be driven not only by mass but also by the nature of cosmic accretion:
at constant galaxy mass, ellipticals are galaxies that are mainly assembled
through mergers, while discs are preferentially built from the in situ star
formation fed by smooth cosmic gas infall.


title: Detecting Asymmetric Dark Matter in the Sun with Neutrinos

abstract:
  Dark Matter (DM) may have a relic density that is in part determined by a
particle/antiparticle asymmetry, much like baryons. If this is the case, it can
accumulate in stars like the Sun to sizable number densities and annihilate to
Standard Model (SM) particles including neutrinos. We show that the combination
of neutrino telescope and direct detection data can be used in conjunction to
determine or constrain the DM asymmetry from data. Depending on the DM mass,
the current neutrino data from Super-K and IceCube give powerful constraints on
asymmetric DM unless its fractional asymmetry is $\lesssim 10^{-2}$. Future
neutrino telescopes and detectors like Hyper-K and KM3NeT can search for the
resulting signal of high-energy neutrinos from the center of the Sun. The
observation of such a flux yields information on both the DM-nucleus cross
section but also on the relative abundances of DM and anti-DM.


title: Magnon spin Nernst effect in antiferromagnets

abstract:
  We predict that a temperature gradient can induce a magnon-mediated spin Hall
response in an antiferromagnet with non-trivial magnon Berry curvature. We
develop a linear response theory which gives a general condition for a Hall
current to be well defined, even when the thermal Hall response is forbidden by
symmetry. We apply our theory to a honeycomb lattice antiferromagnet and
discuss a role of magnon edge states in a finite geometry.


title:
Mid-J CO Shock Tracing Observations of Infrared Dark Clouds III: SLED
  fitting

abstract:
  Giant molecular clouds contain supersonic turbulence that can locally heat
small fractions of gas to over 100 K. We run shock models for low-velocity,
C-type shocks propagating into gas with densities between 10^3 and 10^5 cm^(-3)
and find that CO lines are the most important cooling lines. Comparison to
photodissociation region (PDR) models indicates that mid-J CO lines (J = 8-7
and higher) should be dominated by emission from shocked gas. In Papers I and
II we presented CO J = 3-2, 8-7, and 9-8 observations toward four primarily
quiescent clumps within infrared dark clouds. Here we fit PDR models to the
combined spectral line energy distributions and show that the PDR models that
best fit the low-J CO emission underpredict the mid-J CO emission by orders of
magnitude, strongly hinting at a hot gas component within these clumps. The
low-J CO data clearly show that the integrated intensities of both the CO J =
8-7 and 9-8 lines are anomalously high, such that the line ratio can be used to
characterize the hot gas component. Shock models are reasonably consistent with
the observed mid-J CO emission, with models with densities near 10^(4.5)
cm^(-3) providing the best agreement. Where this mid-J CO is detected, the mean
volume filling factor of the hot gas is 0.1%. Much of the observed mid-J CO
emission, however, is also associated with known protostars and may be due to
protostellar feedback.


title:
Sky reconstruction from transit visibilities: PAON-4 and Tianlai Dish
  Array

abstract:
  The spherical harmonics $m$-mode decomposition is a powerful sky map
reconstruction method suitable for radio interferometers operating in transit
mode. It can be applied to various configurations, including dish arrays and
cylinders. We describe the computation of the instrument response function, the
point spread function (PSF), transfer function, the noise covariance matrix and
noise power spectrum. The analysis in this paper is focused on dish arrays
operating in transit mode. We show that arrays with regular spacing have more
pronounced side lobes as well as structures in their noise power spectrum,
compared to arrays with irregular spacing, specially in the north-south
direction. A good knowledge of the noise power spectrum
$C^{\mathrm{noise}}(\ell)$ is essential for intensity mapping experiments as
non uniform $C^{\mathrm{noise}}(\ell)$ is a potential problem for the
measurement of the HI power spectrum. Different configurations have been
studied to optimise the PAON-4 and Tianlai dish array layouts. We present their
expected performance and their sensitivities to the 21-cm emission of the Milky
Way and local extragalactic HI clumps


title: Generalized Splines and Graphic Arrangements

abstract:
  We define a chain complex for generalized splines on graphs, analogous to
that introduced by Billera and refined by Schenck-Stillman for splines on
polyhedral complexes. The hyperhomology of this chain complex yields bounds on
the projective dimension of the ring of generalized splines. We apply this
construction to the module of derivations of a graphic multi-arrangement,
yielding homological criteria for bounding its projective dimension and
determining freeness. As an application, we show that a graphic arrangement
admits a free constant multiplicity iff it splits as a product of braid
arrangements.


title:
Consistency of the growth rate in different environments with the 6dF
  Galaxy Survey: measurement of the void-galaxy and galaxy-galaxy correlation
  functions

abstract:
  We present a new test of gravitational physics by comparing the growth rate
of cosmic structure measured around voids with that measured around galaxies in
the same large-scale structure dataset, the low-redshift 6-degree Field Galaxy
Survey. By fitting a self-consistent Redshift Space Distortion model to the 2D
galaxy-galaxy and void-galaxy correlation functions, we recover growth rate
values f\sigma_8 = 0.42 \pm 0.06 and 0.39 \pm 0.11, respectively. The
environmental-dependence of cosmological statistics can potentially
discriminate between modified-gravity scenarios which modulate the growth rate
as a function of scale or environment and test the underlying assumptions of
homogeneity and isotropy.


title: Turbulence, Transport and Waves in Ohmic Dead Zones

abstract:
  We use local numerical simulations to study a vertically stratified accretion
disk with a resistive mid-plane that damps magnetohydrodynamic (MHD)
turbulence. This is an idealized model for the dead zones that may be present
at some radii in protoplanetary and dwarf novae disks. We vary the relative
thickness of the dead and active zones to quantify how forced fluid motions in
the dead zone change. We find that the residual Reynolds stress near the
mid-plane decreases with increasing dead zone thickness, becoming negligible in
cases where the active to dead mass ratio is less than a few percent. This
implies that purely Ohmic dead zones would be vulnerable to episodic accretion
outbursts via the mechanism of Martin & Lubow (2011). We show that even thick
dead zones support a large amount of kinetic energy, but this energy is largely
in fluid motions that are inefficient at angular momentum transport. Confirming
results from Oishi & Mac Low (2009), the perturbed velocity field in the dead
zone is dominated by an oscillatory, vertically extended circulation pattern
with a low frequency compared to the orbital frequency. This disturbance has
the properties predicted for the lowest order r mode in a hydrodynamic disk. We
suggest that in a global disk similar excitations would lead to propagating
waves, whose properties would vary with the thickness of the dead zone and the
nature of the perturbations (isothermal or adiabatic). Flows with similar
amplitudes would buckle settled particle layers and could reduce the efficiency
of pebble accretion.


title: Localization transition in one dimension using Wegner flow equations

abstract:
  The flow equation method was proposed by Wegner as a technique for studying
interacting systems in one dimension. Here, we apply this method to a
disordered one dimensional model with power-law decaying hoppings. This model
presents a transition as function of the decaying exponent $\alpha$. We derive
the flow equations, and the evolution of single-particle operators. The flow
equation reveals the delocalized nature of the states for $\alpha<1/2$.
Additionally, in the regime, $\alpha>1/2$, we present a strong-bond
renormalization group structure based on iterating the three-site clusters,
where we solve the flow equations perturbatively. This renormalization group
approach allows us to probe the critical point $\left(\alpha=1\right)$. This
method correctly reproduces the critical level-spacing statistics, and the
fractal dimensionality of the eigenfunctions.


title: Bubbles of Nothing and Supersymmetric Compactifications

abstract:
  We investigate the non-perturbative stability of supersymmetric
compactifications with respect to decay via a bubble of nothing. We show
examples where this kind of instability is not prohibited by the spin
structure, i.e., periodicity of fermions about the extra dimension. However,
such "topologically unobstructed" cases do exhibit an extra-dimensional analog
of the well-known Coleman-De Luccia suppression mechanism, which prohibits the
decay of supersymmetric vacua. We demonstrate this explicitly in a four
dimensional Abelian-Higgs toy model coupled to supergravity. The
compactification of this model to $M_3 \times S_1$ presents the possibility of
vacua with different windings for the scalar field. Away from the
supersymmetric limit, these states decay by the formation of a bubble of
nothing, dressed with an Abelian-Higgs vortex. We show how, as one approaches
the supersymmetric limit, the circumference of the topologically unobstructed
bubble becomes infinite, thereby preventing the realization of this decay. This
demonstrates the dynamical origin of the decay suppression, as opposed to the
more familiar argument based on the spin structure. We conjecture that this is
a generic mechanism that enforces stability of any topologically unobstructed
supersymmetric compactification.


title:
Universal corner entanglement of Dirac fermions and gapless bosons from
  the continuum to the lattice

abstract:
  A quantum critical (QC) fluid exhibits universal subleading corrections to
the area law of its entanglement entropies. In two dimensions when the
partition involves a corner of angle $\theta$, the subleading term is
logarithmic with coefficient $a_\alpha(\theta)$ for the $\alpha$-R\'enyi
entropy. In the smooth limit $\theta\!\to\!\pi$, $a_1(\theta)$ yields the
central charge of the stress tensor when the QC point is described by a
conformal field theory (CFT). For general R\'enyi indices and angles,
$a_\alpha(\theta)$ is richer and few general results exist. We study
$a_\alpha(\theta)$ focusing on two benchmark CFTs, the free Dirac fermion and
boson. We perform numerical lattice calculations to obtain high precision
results in $\theta,\alpha$ regimes hitherto unexplored. We derive field theory
estimates for $a_\alpha(\theta)$, including new exact results, and demonstrate
an excellent quantitative match with our numerical calculations. We also
develop and test strong lower bounds, which apply to both free and interacting
QC systems. Finally, we comment on the near collapse of $a_\alpha(\theta)$ for
various theories, including interacting $O(N)$ models.


title: A collider observable QCD axion

abstract:
  We present a model where the QCD axion is at the TeV scale and visible at a
collider via its decays. Conformal dynamics and strong CP considerations
account for the axion coupling strongly enough to the standard model to be
produced as well as the coincidence between the weak scale and the axion mass.
The model predicts additional pseudoscalar color octets whose properties are
completely determined by the axion properties rendering the theory testable.


title: The Segre zeta function of an ideal

abstract:
  We define a power series associated with a homogeneous ideal in a polynomial
ring, encoding information on the Segre classes defined by extensions of the
ideal in projective spaces of arbitrarily high dimension. We prove that this
power series is rational, with poles corresponding to generators of the ideal,
and with numerator of bounded degree and with nonnegative coefficients. We also
prove that this `Segre zeta function' only depends on the integral closure of
the ideal.
  The results follow from good functoriality properties of the `shadows' of
rational equivalence classes of projective bundles. More precise results can be
given if all homogeneous generators have the same degree, and for monomial
ideals.
  In certain cases, the general description of the Segre zeta function given
here leads to substantial improvements in the speed of algorithms for the
computation of Segre classes. We also compute the projective ranks of a
nonsingular variety in terms of the corresponding zeta function, and we discuss
the Segre zeta function of a local complete intersection of low codimension in
projective space.


title:
Prompt Signals and Displaced Vertices in Sparticle Searches for
  Next-to-Minimal Gauge Mediated Supersymmetric Models

abstract:
  We study the LHC phenomenology of the next-to-minimal model of gauge-mediated
supersymmetry breaking (NMGMSB), both for Run I and Run II. The Higgs
phenomenology of the model is consistent with observations: a 125 GeV Standard
Model-like Higgs which mixes with singlet-like state of mass around 90 GeV that
provides a 2$\sigma$ excess at LEP II. The model possesses regions of parameter
space where a longer-lived lightest neutralino decays in the detector into a
gravitino and a $b-$jet pair or a tau pair. We investigate current lower bounds
on sparticle masses and the discovery potential of the model, both via
conventional sparticle searches and via searches for displaced vertices. The
strongest bound from searches for promptly decaying sparticles yields a lower
limit on the gluino mass of 1080 GeV. An analysis of 100 fb$^{-1}$ from Run II,
on the other hand, is expected to be sensitive up to 1900 GeV. The displaced
vertex searches from Run I suffer from a very low signal efficiency, mainly due
to the presence of $b-$quarks in the final state. We show how the displaced
vertex cuts might be relaxed in order to improve signal efficiency, while
simultaneous prompt objects can be used to cut down background. We find that a
combined search strategy with both prompt and displaced cuts potentially has a
far better sensitivity to this model than either set alone, motivating a fully
fledged experimental study.


title: A novel mechanism for the distance-redshift relation

abstract:
  We consider a novel mechanism to account for the observed distance-redshift
relation. This is done by presenting a toy model for the large-scale matter
distribution in a static Universe. Our model mainly concerns particles with
masses far below those in the Standard Model of Particle Physics. The model is
founded on three main assumptions: (1) a mass spectrum dN$_{\rm i}$/dm$_{\rm
i}$ $=$ $\beta$m$_{\rm i}^{-\alpha}$ (where $\alpha$ and $\beta$ are both
positive constants) for low-mass particles with m$_{\rm i}$ $\ll$ 10$^{-22}$ eV
$\ll$ M$_{\rm P}$, where M$_{\rm P}$ is the Planck mass; (2) a particle
mass-wavelength relation of the form $\lambda_{\rm i} =$ $\hbar$/$\delta_{\rm
i}$m$_{\rm i}$c, where $\delta_{\rm i} =$ $\eta$m$_{\rm i}^{\gamma}$ and $\eta$
and $\gamma$ are both constants; and (3) For such low-mass particles, locality
can only be defined on large spatial scales, comparable to or exceeding the
particle wavelengths.
  We use our model to derive the cosmological redshift characteristic of the
Standard Model of Cosmology, which becomes a gravitational redshift in our
model. We compare the results of our model to empirical data and show that, in
order to reproduce the sub-linear form of the observed distance-redshift
relation, our model requires $\alpha$ + $\gamma$ $<$ 0. We further place our
toy model in the context of the Friedmann Universe via a superposition of
Einstein Universes, each with its own scale factor a$_{\rm i}$. Given the
overwhelming evidence supporting an expanding Universe, we then address
possible modifications to our base model that would be required to account for
the available empirical constraints, including the addition of some initial
expansion. Finally, we consider potentially observable distinctions between the
cosmological redshift and our proposed mechanism to account for the observed
distance-redshift relation.


title: An embedding constant for the Hardy space of Dirichlet series

abstract:
  A new and simple proof of the embedding of the Hardy--Hilbert space of
Dirichlet series into a conformally invariant Hardy space of the half-plane is
presented, and the optimal constant of the embedding is computed.


title:
Neutrino mass hierarchy and \delta^{CP} investigation within the
  biprobability (P-P^T ) plane

abstract:
  This article illustrates the possibility of investigating mass hierarchy and
CP-violating phase \delta^{CP}, in the context of CP trajectory diagrams in the
bi-probability plane. Separation between normal mass hierarchy (NH) and
inverted mass hierarchy (IH) CP trajectory ellipses in the P-P^T plane seems to
be very promising in order to investigate mass hierarchy. Illustration of
separation between two hierarchy ellipses in the E-L plane is very helping to
cover all the desired base lines and beam energies and also to analyze benefits
and drawbacks at single place. If we know the mass hierarchy, then from the
large sizes of CP trajectory ellipse which is possible at appropriately long
base line (L) and at specific value of beam energy (E), it becomes possible to
investigate at-least narrow ranges of CP/T-violating phase \delta^{CP}. The
Possibility of more than one set of (\theta_{13}; \delta^{CP}) parameters to
correspond to any chosen coordinate in P-P^T plane, known as parameter
degeneracy, may hinder exact determination of mass hierarchy as well as
\delta^{CP} value. To circumvent this degeneracy in the (\theta_{13};
\delta^{CP}) parameter space, in case of opposite sign solutions corresponding
to NH and IH case points toward the need of sufficiently long base lines, so as
to separate opposite hierarchy ellipses to observable separation, and in case
of same sign solutions corresponding to either NH or IH, we need to choose an
experimental configuration with L = 2,535 Km, E = 5 GeV for n=1 scenario.


title: Scattering with partial information

abstract:
  We study relativistic scattering when one only has access to a subset of the
particles, using the language of quantum measurement theory. We give an exact,
non-perturbative formula for the von Neumann entanglement entropy of an
apparatus particle scattered off an arbitrary set of system particles, in
either the elastic or inelastic regime, and show how to evaluate it
perturbatively. We give general formulas for the late-time expectation values
of apparatus observables. Some simple example applications are included: in
particular, a protocol to verify preparation of coherent superpositions of
spatially localized system states using position-space information in the
outgoing apparatus state, at lowest order in perturbation theory in a weak
apparatus-system coupling.


title: First Sound in Holographic Superfluids at Zero Temperature

abstract:
  Within the context of AdS/CFT, the gravity dual of an s-wave superfluid is
given by scalar QED on an asymptotically AdS spacetime. While this conclusion
is vastly supported by numerical arguments, here we provide an analytical proof
that this is indeed the case. Working at zero temperature, we explicitly find
the quadratic action for the superfluid phonon at the boundary in an arbitrary
number of dimensions and for an arbitrary scalar field potential, recovering
the known dispersion relation for conformal first sound.


title: On the discriminant of twisted tensor products

abstract:
  We provide formulas for computing the discriminant of noncommutative algebras
over central subalgebras in the case of Ore extensions and skew group
extensions. The formulas follow from a more general result regarding the
discriminants of certain twisted tensor products. We employ our formulas to
compute automorphism groups for examples in each case.


title: An extended footnote on finitely minimal martingale measures

abstract:
  This note contains a short discussion on the sufficiency of finite optimality
in martingale transport. It is shown that finitely minimal martingale measures
are solutions of the martingale transport problem when the cost function is
upper semi-continuous and bounded from above by a sum of integrable functions.
As an application a transparent proof of the uniqueness of left-monotone
martingale transport plans is given.


title:
Constraining anomalous Higgs boson couplings to the heavy flavor
  fermions using matrix element techniques

abstract:
  In this paper we investigate anomalous interactions of the Higgs boson with
heavy fermions, employing shapes of kinematic distributions. We study the
processes $pp \to t\bar{t} + H$, $b\bar{b} + H$, $tq+H$, and $pp \to
H\to\tau^+\tau^-$, and present applications of event generation, re-weighting
techniques for fast simulation of anomalous couplings, as well as matrix
element techniques for optimal sensitivity. We extend the MELA technique, which
proved to be a powerful matrix element tool for Higgs boson discovery and
characterization during Run I of the LHC, and implement all analysis tools in
the JHU generator framework. A next-to-leading order QCD description of the $pp
\to t\bar{t} + H$ process allows us to investigate the performance of MELA in
the presence of extra radiation. Finally, projections for LHC measurements
through the end of Run III are presented.


title: Ising Spin Glasses in dimension five

abstract:
  Ising spin glass models with bimodal, Gaussian, uniform and Laplacian
interaction distributions in dimension five are studied through detailed
numerical simulations. The data are analyzed in both the finite-size scaling
regime and the thermodynamic limit regime. It is shown that the values of
critical exponents and of dimensionless observables at criticality are model
dependent. Models in a single universality class have identical values for each
of these critical parameters, so Ising spin glass models in dimension five with
different interaction distributions each lie in different universality classes.
This result confirms conclusions drawn from measurements in dimension four and
dimension two.


title: On joint sum/max stability and sum/max domains of attraction

abstract:
  Let (W_i, J_i) be a sequence of i.i.d. R_+ x R-valued random vectors.
Considering the partial sum of the first component and the corresponding
maximum of the second component, we are interested in the limit distributions
that can be obtained under an appropriate scaling. In the case that W_i and J_i
are independent, the joint distribution of the sum and the maximum is the
product measure of the limit distributions of the two components. But if we
allow dependence between the two components, this dependence can still appear
in the limit, and we need a new theory to describe the possible limit
distributions. This is achieved via harmonic analysis on semigroups, which can
be utilized to characterize the scaling limit distributions and describe their
domains of attraction.


title: Boggio's formula for fractional polyharmonic Dirichlet problems

abstract:
  Boggio's formula in balls is known for integer-polyharmonic Dirichlet
problems and for fractional Dirichlet problems with fractional parameter less
than 1. We give here a consistent formulation for fractional polyharmonic
Dirichlet problems such that Boggio's formula in balls yields solutions also
for the general fractional case.


title: Dependence of two-proton radioactivity on nuclear pairing models

abstract:
  Sensitivity of two-proton emitting decay to nuclear pairing correlation is
discussed within a time-dependent three-body model. We focus on the $^6$Be
nucleus assuming $\alpha + p + p$ configuration, and its decay process is
described as a time-evolution of the three-body resonance state. For a
proton-proton subsystem, a schematic density-dependent contact (SDDC) pairing
model is employed. From the time-dependent calculation, we observed the
exponential decay rule of a two-proton emission. It is shown that the density
dependence does not play a major role in determining the decay width, which can
be controlled only by the asymptotic strength of the pairing interaction. This
asymptotic pairing sensitivity can be understood in terms of the dynamics of
the wave function driven by the three-body Hamiltonian, by monitoring the
time-dependent density distribution. With this simple SDDC pairing model, there
remains an impossible trinity problem: it cannot simultaneously reproduce the
empirical $Q$ value, decay width, and the nucleon-nucleon scattering length.
This problem suggests that a further sophistication of the theoretical pairing
model is necessary, utilizing the two-proton radioactivity data as the
reference quantities.


title: Absorption of a Particle by a Rotating Black Hole: The Potential Barrier

abstract:
  For a test particle approaching a rapidly rotating black hole we find a range
of values of the particle's energy and angular momentum, on the order of 1\% or
more of the corresponding values of the hole, such that three conditions are
satisfied. 1) The particle can reach the horizon. 2) After absorption the new
hole still has a horizon. 3) The area of the new hole is less than the area of
the original one, in apparent violation of a theorem of Hawking. We offer
support for the claim that the test particle approximation is the cause of the
violation.


title: Tilings in graphons

abstract:
  We introduce a counterpart to the notion of vertex disjoint tilings by copy
of a fixed graph F to the setting of graphons. The case F=K_2 gives the notion
of matchings in graphons. We give a transference statement that allows us to
switch between the finite and limit notion, and derive several favorable
properties, including the LP-duality counterpart to the classical relation
between the fractional vertex covers and fractional matchings/tilings, and
discuss connections with property testing. As an application of our theory, we
determine the asymptotically almost sure F-tiling number of inhomogeneous
random graphs \mathbb{G}(n,W). As another application, in an accompanying paper
[Hladky, Hu, Piguet: Komlos's tiling theorem via graphon covers, preprint] we
give a proof of a strengthening of a theorem of Komlos [Komlos: Tiling Tur\'an
Theorems, Combinatorica, 2000].


title:
The Alcock Paczynski test with Baryon Acoustic Oscillations: systematic
  effects for future surveys

abstract:
  We investigate the Alcock Paczynski (AP) test applied to the Baryon Acoustic
Oscillation (BAO) feature in the galaxy correlation function. By using a
general formalism that includes relativistic effects, we quantify the
importance of the linear redshift space distortions and gravitational lensing
corrections to the galaxy number density fluctuation. We show that redshift
space distortions significantly affect the shape of the correlation function,
both in radial and transverse directions, causing different values of galaxy
bias to induce offsets up to 1% in the AP test. On the other hand, we find that
the lensing correction around the BAO scale modifies the amplitude but not the
shape of the correlation function and therefore does not introduce any
systematic effect. Furthermore, we investigate in details how the AP test is
sensitive to redshift binning: a window function in transverse direction
suppresses correlations and shifts the peak position toward smaller angular
scales. We determine the correction that should be applied in order to account
for this effect, when performing the test with data from three future planned
galaxy redshift surveys: Euclid, the Dark Energy Spectroscopic Instrument
(DESI) and the Square Kilometer Array (SKA).


title:
On the role of dissipation in structure formation for dilute
  relativistic gases: the static background case

abstract:
  A correction to the Jeans stability criterion due to heat conduction is
established for the case of high temperature gases. This effect is only
relevant for relativistic fluids and includes an additional term due to a
density gradient driven heat flux. The result is obtained by thoroughly
analyzing the exponentially growing modes present in the dynamics of density
fluctuations in the linearized relativistic Navier-Stokes regime. The
corrections to the corresponding Jeans mass and wavenumber are explicitly
obtained and are compared to the non-relativistic and non-dissipative values
using the transport coefficients obtained in the BGK approximation.


title: Rubel's problem on bounded analytic functions

abstract:
  The paper shows that for any $G_\delta$ set $F$ of Lebesgue measure zero on
the unit circle $T$ there exists a function $f \in H^{\infty}$ such that the
radial limits of $f$ exist at each point of $T$ and vanish precisely on $F$.
This solves a problem proposed by Lee Rubel in 1973.


title: Analytic gravitational waveforms for generic precessing compact binaries

abstract:
  Binary systems of two compact objects circularize and spiral toward each
other via the emission of gravitational waves. The coupling of the spins of
each object with the orbital angular momentum causes the orbital plane to
precess, which leads to modulation of the gravitational wave signal. Until now,
generating frequency-domain waveforms for fully precessing systems for use in
gravitational wave data analysis meant numerically integrating the equations of
motion, then Fourier transforming the result, which is very computationally
intensive for systems that complete hundreds or thousands of cycles in the
sensitive band of a detector. Previously, analytic solutions were only
available for certain special cases or for simplified models. Here we describe
the construction of closed-form, frequency-domain waveforms for
fully-precessing, quasi-circular binary inspirals.


title: A Dwarf Protoplanetary Disk around XZ Tau B

abstract:
  We report the discovery of a dwarf protoplanetary disk around the star XZ Tau
B that shows all the features of a classical transitional disk but on a much
smaller scale. The disk has been imaged with the Atacama Large
Millimeter/Submillimeter Array (ALMA), revealing that its dust emission has a
quite small radius of ~ 3.4 au and presents a central cavity of ~ 1.3 au in
radius that we attribute to clearing by a compact system of orbiting
(proto)planets. Given the very small radii involved, evolution is expected to
be much faster in this disk (observable changes in a few months) than in
classical disks (observable changes requiring decades) and easy to monitor with
observations in the near future. From our modeling we estimate that the mass of
the disk is large enough to form a compact planetary system.


title: Derivations and Centroids of Four Dimensional Associative Algebras

abstract:
  In this paper, we focus on derivations and centroids of four dimensional
associative algebras. Using an existing classification result of low
dimensional associative algebras, we describe the derivations and centroids of
four dimensional associative algebras. We also identify algebra(s) that belong
to the characteristically nilpotent class among the algebras of four
dimensional associative algebras.


title: Photoassociative production of ultracold heteronuclear YbLi* molecules

abstract:
  We report on the production of ultracold heteronuclear YbLi* molecules in a
dual-species magneto-optical trap by photoassociation (PA). The formation of
the electronically excited molecules close to dissociation was observed by trap
loss spectroscopy. We find 4 rovibrational states within a range of $250\,$GHz
below the Yb($^1S_0$) + Li($^2P_{1/2}$) asymptote and observe isotopic PA line
shifts in mixtures of $^6$Li with $^{174}$Yb, $^{172}$Yb, and $^{176}$Yb. We
also describe our theoretical ab-initio calculation for the relevant electronic
potentials and utilize it to analyze and identify the lines in the
experimentally observed spectrum.


title: The role of turbulence, magnetic fields and feedback for star formation

abstract:
  Star formation is inefficient. Only a few percent of the available gas in
molecular clouds forms stars, leading to the observed low star formation rate
(SFR). The same holds when averaged over many molecular clouds, such that the
SFR of whole galaxies is again surprisingly low. Indeed, considering the low
temperatures, molecular clouds should be highly gravitationally unstable and
collapse on their global mean freefall timescale. And yet, they are observed to
live about 10-100 times longer, i.e., the SFR per freefall time is only a few
percent. Thus, other physical mechanisms must provide support against quick
global collapse. Magnetic fields, turbulence and stellar feedback have been
proposed as stabilising agents controlling star formation, but it is still
unclear which of these processes is the most important and what their relative
contributions are. Here I present high-resolution, adaptive-mesh-refinement
simulations of star cluster formation that include turbulence, magnetic fields,
and protostellar jet/outflow feedback. These simulations produce nearly
realistic star formation rates consistent with observations, but only if
turbulence, magnetic fields and feedback are included simultaneously.

categories: astro-ph.GA astro-ph.SR physics.comp-ph physics.plasm-ph


title:
Asymptotically Hilbertian Modular Banach Spaces: Examples of Uncountable
  Categoricity

abstract:
  We give a criterion ensuring that the elementary class of a modular Banach
space E (that is, the class of Banach spaces, some ultrapower of which is
linearly isometric to an ultrapower of E) consists of all direct sums E\oplus_m
H, where H is an arbitrary Hilbert space and \oplus_m denotes the modular
direct sum. Also, we give several families of examples in the class of Nakano
direct sums of finite dimensional normed spaces that satisfy this criterion.
This yields many new examples of uncountably categorical Banach spaces, in the
model theory of Banach space structures.


title:
Ternary borides Nb$_7$Fe$_3$B$_8$ and Ta$_7$Fe$_3$B$_8$ with Kagome-type
  iron framework

abstract:
  Two new ternary borides $TM$$_7$Fe$_3$B$_8$ ($TM$ = Nb, Ta) were synthesized
by high-temperature thermal treatment of samples obtained by arc-melting. This
new type of structure with space group $P$6/$mmm$, comprises $TM$ slabs
containing isolated planar hexagonal [B$_6$] rings and iron centered $TM$
columns in a Kagome type of arrangement. Chemical bonding analysis in
Nb$_7$Fe$_3$B$_8$ by means of the electron localizability approach reveals
two-center interactions forming the Kagome net of Fe and embedded B, while
weaker multicenter bonding present between this net and Nb atoms. Magnetic
susceptibility measurements reveal antiferromagnetic order below $T_N$ = 240 K
for Nb$_7$Fe$_3$B$_8$ and $T_N$ =265 K for Ta$_7$Fe$_3$B$_8$. Small remnant
magnetization below 0.01 $\mu_B$/f.u. is observed in the antiferromagnetic
state. The bulk nature of the magnetic transitions was confirmed by the
hyperfine splitting of the M\"o{\ss}bauer spectra, the sizable anomalies in the
specific heat capacity, and the kinks in the resistivity curves. The high-field
paramagnetic susceptibilities fitted by the Curie-Weiss law show effective
paramagnetic moments $\mu_{eff}$ about 3.1 $\mu_B$/Fe in both compounds. The
temperature dependence of the electrical resistivity also reveals metallic
character of both compounds. Density functional calculations corroborate the
metallic behaviour of both compounds and demonstrate the formation of a sizable
local magnetic moment on the Fe-sites. They indicate the presence of both
antiferro- and ferromagnetic interactions.


title: Random Matrix Theory of Resonances: an Overview

abstract:
  Scattering of electromagnetic waves in billiard-like systems has become a
standard experimental tool of studying properties associated with Quantum
Chaos. Random Matrix Theory (RMT) describing statistics of eigenfrequencies and
associated eigenfunctions remains one of the pillars of theoretical
understanding of quantum chaotic systems. In a scattering system coupling to
continuum via antennae converts real eigenfrequencies into poles of the
scattering matrix in the complex frequency plane and the associated
eigenfunctions into decaying resonance states. Understanding statistics of
these poles, as well as associated non-orthogonal resonance eigenfunctions
within RMT approach is still possible, though much more challenging task.


title: OGLE16aaa - a Signature of a Hungry Super Massive Black Hole

abstract:
  We present the discovery and first three months of follow-up observations of
a currently on-going unusual transient detected by the OGLE-IV survey, located
in the centre of a galaxy at redshift z=0.1655. The long rise to absolute
magnitude of -20.5 mag, slow decline, very broad He and H spectral features
make OGLE16aaa similar to other optical/UV Tidal Disruption Events (TDEs). Weak
narrow emission lines in the spectrum and archival photometric observations
suggest the host galaxy is a weak-line Active Galactic Nucleus (AGN), which has
been accreting at higher rate in the past. OGLE16aaa, along with SDSS J0748,
seems to form a sub-class of TDEs by weakly or recently active super-massive
black holes (SMBHs). This class might bridge the TDEs by quiescent SMBHs and
flares observed as "changing-look QSOs", if we interpret the latter as TDEs. If
this picture is true, the previously applied requirement for identifying a
flare as a TDE that it had to come from an inactive nucleus, could be leading
to observational bias in TDE selection, thus affecting TDE-rate estimations.


title: Key-Value Memory Networks for Directly Reading Documents

abstract:
  Directly reading documents and being able to answer questions from them is an
unsolved challenge. To avoid its inherent difficulty, question answering (QA)
has been directed towards using Knowledge Bases (KBs) instead, which has proven
effective. Unfortunately KBs often suffer from being too restrictive, as the
schema cannot support certain types of answers, and too sparse, e.g. Wikipedia
contains much more information than Freebase. In this work we introduce a new
method, Key-Value Memory Networks, that makes reading documents more viable by
utilizing different encodings in the addressing and output stages of the memory
read operation. To compare using KBs, information extraction or Wikipedia
documents directly in a single framework we construct an analysis tool,
WikiMovies, a QA dataset that contains raw text alongside a preprocessed KB, in
the domain of movies. Our method reduces the gap between all three settings. It
also achieves state-of-the-art results on the existing WikiQA benchmark.


title: Real Algebraic Geometry for Geometric Constraints

abstract:
  Real algebraic geometry adapts the methods and ideas from (complex) algebraic
geometry to study the real solutions to systems of polynomial equations and
polynomial inequalities. As it is the real solutions to such systems modeling
geometric constraints that are physically meaningful, real algebraic geometry
is a core mathematical input for geometric constraint systems.


title: Chevalley-Weil Theorem and Subgroups of Class Groups

abstract:
  We prove, under some mild hypothesis, that an \'etale cover of curves defined
over a number field has infinitely many specializations into an everywhere
unramified extension of number fields. This constitutes an "absolute" version
of the Chevalley-Weil theorem. Using this result, we are able to generalize the
techniques of Mestre, Levin and the second author for constructing and counting
number fields with large class group.


title:
The stabilizer group of honeycomb lattices and its application to
  deformed monolayers

abstract:
  Isospectral transformations of exactly solvable models constitute a fruitful
method for obtaining new structures with prescribed properties. In this paper
we study the stability group of the Dirac algebra in honeycomb lattices
representing graphene or boron nitride. New crystalline arrays with conical
(Dirac) points are obtained; in particular, a model for dichalcogenide
monolayers is proposed and analyzed. In our studies we encounter unitary and
non-unitary transformations. We show that the latter give rise to $\mbox{$\cal
P\,$}\mbox{$\cal T\,$}$-symmetric Hamiltonians, in compliance with known
results in the context of boosted Dirac equations. The results of the unitary
part are applied to the description of invariant bandgaps and dispersion
relations in materials such as MoS$_2$. A careful construction based on atomic
orbitals is proposed and the resulting dispersion relation is compared with
previous results obtained through DFT.

categories: quant-ph cond-mat.mtrl-sci math-ph math.MP


title: Coevolving complex networks in the model of social interactions

abstract:
  We analyze Axelrod's model of social interactions on coevolving complex
networks. We introduce four extensions with different mechanisms of edge
rewiring. The models are intended to catch two kinds of interactions -
preferential attachment, which can be observed in scientists or actors
collaborations, and local rewiring, which can be observed in friendship
formation in everyday relations. Numerical simulations show that proposed
dynamics can lead to the power-law distribution of nodes' degree and high value
of the clustering coefficient, while still retaining the small-world effect in
three models. All models are characterized by two phase transitions of a
different nature. In case of local rewiring we obtain order-disorder
discontinuous phase transition even in the thermodynamic limit, while in case
of long-distance switching discontinuity disappears in the thermodynamic limit,
leaving one continuous phase transition. In addition, we discover a new and
universal characteristic of the second transition point - an abrupt increase of
the clustering coefficient, due to formation of many small complete subgraphs
inside the network.


title: Asymptotics for moments of certain cotangent sums

abstract:
  In this paper we improve a result on the order of magnitude of certain
cotangent sums associated to the Estermann and the Riemann zeta functions.


title:
The $C^0$ integrability of symplectic twist maps without conjugate
  points

abstract:
  We prove that symplectic twist maps defined on the cotangent bundle of the
d-dimensional torus that have no conjugate points are $C^0$ integrable, i.e.
the cotangent bundle is continuously foliated by a family of invariant
Lagrangian graphs.


title:
Metastability of Mn$^{3+}$ in ZnO driven by strong $d$(Mn) intrashell
  Coulomb repulsion: experiment and theory

abstract:
  Depopulation of the Mn$^{2+}$ state in ZnO:Mn upon illumination, monitored by
quenching of the Mn$^{2+}$ EPR signal intensity, was observed at temperatures
below 80~K. Mn$^{2+}$ photoquenching is shown to result from the Mn$^{2+}$
$\to$ Mn$^{3+}$ ionization transition, promoting one electron to the conduction
band. Temperature dependence of this process indicates the existence of an
energy barrier for electron recapture of the order of 1~meV. GGA$+U$
calculations show that after ionization of Mn$^{2+}$ a moderate breathing
lattice relaxation in the 3+ charge state occurs, which increases energies of
$d$(Mn) levels. At its equilibrium atomic configuration, Mn$^{3+}$ is
metastable since the direct capture of photo-electron is not possible. The
metastability is mainly driven by the strong intra-shell Coulomb repulsion
between $d$(Mn) electrons. Both the estimated barrier for electron capture and
the photoionization energy are in good agreement with the experimental values.


title: Limits on Planetary Companions from Doppler Surveys of Nearby Stars

abstract:
  Most of our knowledge of planets orbiting nearby stars comes from Doppler
surveys. For spaced-based, high-contrast imaging missions, nearby stars with
Doppler-discovered planets are attractive targets. The known orbits tell
imaging missions where and when to observe, and the dynamically-determined
masses provide important constraints for the interpretation of planetary
spectra. Quantifying the set of planet masses and orbits that could have been
detected will enable more efficient planet discovery and characterization. We
analyzed Doppler measurements from Lick and Keck Observatories collected by the
California Planet Survey. We focused on stars that are likely targets for three
space-based planet imaging mission concepts studied by NASA--WFIRST-AFTA,
Exo-C, and Exo-S. The Doppler targets are primarily F8 and later main sequence
stars, with observations spanning 1987-2014. We identified 76 stars with
Doppler measurements from the prospective mission target lists. We developed an
automated planet search and a methodology to estimate the pipeline completeness
using injection and recovery tests. We applied this machinery to the Doppler
data and computed planet detection limits for each star as a function of planet
minimum mass and semi-major axis. For typical stars in the survey, we are
sensitive to approximately Saturn-mass planets inside of 1 AU, Jupiter-mass
planets inside of ~3 AU, and our sensitivity declines out to ~10 AU. For the
best Doppler targets, we are sensitive to Neptune-mass planets in 3 AU orbits.
Using an idealized model of Doppler survey completeness, we forecast the
precision of future surveys of non-ideal Doppler targets that are likely
targets of imaging missions.


title:
The Overlapped Radial Basis Function-Finite Difference (RBF-FD) Method:
  A Generalization of RBF-FD

abstract:
  We present a generalization of the RBF-FD method that computes RBF-FD weights
in finite-sized neighborhoods around the centers of RBF-FD stencils by
introducing an overlap parameter $\delta \in [0,1]$ such that $\delta=1$
recovers the standard RBF-FD method and $\delta=0$ results in a full decoupling
of stencils. We provide experimental evidence to support this generalization,
and develop an automatic stabilization procedure based on local Lebesgue
functions for the stable selection of stencil weights over a wide range of
$\delta$ values. We provide an a priori estimate for the speedup of our method
over RBF-FD that serves as a good predictor for the true speedup. We apply our
method to parabolic partial differential equations with time-dependent
inhomogeneous boundary conditions-- Neumann in 2D, and Dirichlet in 3D. Our
results show that our method can achieve as high as a 60x speedup in 3D over
existing RBF-FD methods in the task of forming differentiation matrices.


title: Dynamical sampling and systems from iterative actions of operators

abstract:
  We review some of the recent developments and prove new results concerning
frames and Bessel systems generated by iterations of the form $\{A^ng: g\in
G,\, n=0,1,2,\dots \}$, where $A$ is a bounded linear operators on a separable
complex Hilbert space $ \mathcal{H} $ and $G$ is a countable set of vectors in
$ \mathcal{H} $. The system of iterations mentioned above was motivated from
the so called dynamical sampling problem. In dynamical sampling, an unknown
function $f$ and its future states $A^nf$ are coarsely sampled at each time
level $n$, $0\leq n< L$, where $A$ is an evolution operator that drives the
system. The goal is to recover $f$ from these space-time samples.


title: Cooperative Inverse Reinforcement Learning

abstract:
  For an autonomous system to be helpful to humans and to pose no unwarranted
risks, it needs to align its values with those of the humans in its environment
in such a way that its actions contribute to the maximization of value for the
humans. We propose a formal definition of the value alignment problem as
cooperative inverse reinforcement learning (CIRL). A CIRL problem is a
cooperative, partial-information game with two agents, human and robot; both
are rewarded according to the human's reward function, but the robot does not
initially know what this is. In contrast to classical IRL, where the human is
assumed to act optimally in isolation, optimal CIRL solutions produce behaviors
such as active teaching, active learning, and communicative actions that are
more effective in achieving value alignment. We show that computing optimal
joint policies in CIRL games can be reduced to solving a POMDP, prove that
optimality in isolation is suboptimal in CIRL, and derive an approximate CIRL
algorithm.


title: Formal Modeling and Analysis of Pancreatic Cancer Microenvironment

abstract:
  The focus of pancreatic cancer research has been shifted from pancreatic
cancer cells towards their microenvironment, involving pancreatic stellate
cells that interact with cancer cells and influence tumor progression. To
quantitatively understand the pancreatic cancer microenvironment, we construct
a computational model for intracellular signaling networks of cancer cells and
stellate cells as well as their intercellular communication. We extend the
rule-based BioNetGen language to depict intra- and inter-cellular dynamics
using discrete and continuous variables respectively. Our framework also
enables a statistical model checking procedure for analyzing the system
behavior in response to various perturbations. The results demonstrate the
predictive power of our model by identifying important system properties that
are consistent with existing experimental observations. We also obtain
interesting insights into the development of novel therapeutic strategies for
pancreatic cancer.


title: Abstract Harmonic Analysis On the non Singular Matrix Lie Group

abstract:
  As well known that it is no way to do the abstract harmonic analysis on the
non connected Lie groups. The goal of this paper is to draw the attention of
Mathematicians to solve this problem. therefore let R be the group of nonzero
real numbers with multiplication and let H be the 3-dimensional Heisenberg
group. I denote by G the semi direct of the Heisenberg group with R3 which is
non connected solvable Lie group, and isomorphic onto the 6- dimensional non
singular triangular matrix Lie group. I define the Fourier-Mellin transform and
establish the Plancherel theorem on the group G. Besides I prove the
solvability of any non zero invariant differential operator on the identity
component of the group G. Finally, I give a classification of all left ideals
of the its group algebra


title:
Tsirelson's problem and an embedding theorem for groups arising from
  non-local games

abstract:
  Tsirelson's problem asks whether the commuting operator model for two-party
quantum correlations is equivalent to the tensor-product model. We give a
negative answer to this question by showing that there are non-local games
which have perfect commuting-operator strategies, but do not have perfect
tensor-product strategies. The weak Tsirelson problem, which is known to be
equivalent to Connes embedding problem, remains open.
  The examples we construct are instances of (binary) linear system games. For
such games, previous results state that the existence of perfect strategies is
controlled by the solution group of the linear system. Our main result is that
every finitely-presented group embeds in some solution group. As an additional
consequence, we show that the problem of determining whether a linear system
game has a perfect commuting-operator strategy is undecidable.

categories: quant-ph math-ph math.GR math.MP math.OA


title: Mutual Exclusivity Loss for Semi-Supervised Deep Learning

abstract:
  In this paper we consider the problem of semi-supervised learning with deep
Convolutional Neural Networks (ConvNets). Semi-supervised learning is motivated
on the observation that unlabeled data is cheap and can be used to improve the
accuracy of classifiers. In this paper we propose an unsupervised
regularization term that explicitly forces the classifier's prediction for
multiple classes to be mutually-exclusive and effectively guides the decision
boundary to lie on the low density space between the manifolds corresponding to
different classes of data. Our proposed approach is general and can be used
with any backpropagation-based learning method. We show through different
experiments that our method can improve the object recognition performance of
ConvNets using unlabeled data.


title:
Branched covers of elliptic curves and K\"ahler groups with exotic
  finiteness properties

abstract:
  We construct K\"ahler groups with arbitrary finiteness properties by mapping
products of closed Riemann surfaces holomorphically onto an elliptic curve: for
each $r\geq 3$, we obtain large classes of K\"ahler groups that have
classifying spaces with finite $(r-1)$-skeleton but do not have classifying
spaces with finitely many $r$-cells. We describe invariants which distinguish
many of these groups. Our construction is inspired by examples of Dimca,
Papadima and Suciu.


title: PerSum: Novel Systems for Document Summarization in Persian

abstract:
  In this paper we explore the problem of document summarization in Persian
language from two distinct angles. In our first approach, we modify a popular
and widely cited Persian document summarization framework to see how it works
on a realistic corpus of news articles. Human evaluation on generated summaries
shows that graph-based methods perform better than the modified systems. We
carry this intuition forward in our second approach, and probe deeper into the
nature of graph-based systems by designing several summarizers based on
centrality measures. Ad hoc evaluation using ROUGE score on these summarizers
suggests that there is a small class of centrality measures that perform better
than three strong unsupervised baselines.


title:
Sentence Similarity Measures for Fine-Grained Estimation of Topical
  Relevance in Learner Essays

abstract:
  We investigate the task of assessing sentence-level prompt relevance in
learner essays. Various systems using word overlap, neural embeddings and
neural compositional models are evaluated on two datasets of learner writing.
We propose a new method for sentence-level similarity calculation, which learns
to adjust the weights of pre-trained word embeddings for a specific task,
achieving substantially higher accuracy compared to other relevant baselines.