title:
Covariants of binary sextics and vector-valued Siegel modular forms of
  genus two

abstract:
  We extend Igusa's description of the relation between invariants of binary
sextics and Siegel modular forms of degree two to a relation between covariants
and vector-valued Siegel modular forms of degree two. We show how this relation
can be used to effectively calculate the Fourier expansions of Siegel modular
forms of degree two.


title: Joint M-Best-Diverse Labelings as a Parametric Submodular Minimization

abstract:
  We consider the problem of jointly inferring the M-best diverse labelings for
a binary (high-order) submodular energy of a graphical model. Recently, it was
shown that this problem can be solved to a global optimum, for many practically
interesting diversity measures. It was noted that the labelings are, so-called,
nested. This nestedness property also holds for labelings of a class of
parametric submodular minimization problems, where different values of the
global parameter $\gamma$ give rise to different solutions. The popular example
of the parametric submodular minimization is the monotonic parametric max-flow
problem, which is also widely used for computing multiple labelings. As the
main contribution of this work we establish a close relationship between
diversity with submodular energies and the parametric submodular minimization.
In particular, the joint M-best diverse labelings can be obtained by running a
non-parametric submodular minimization (in the special case - max-flow) solver
for M different values of $\gamma$ in parallel, for certain diversity measures.
Importantly, the values for $\gamma$ can be computed in a closed form in
advance, prior to any optimization. These theoretical results suggest two
simple yet efficient algorithms for the joint M-best diverse problem, which
outperform competitors in terms of runtime and quality of results. In
particular, as we show in the paper, the new methods compute the exact M-best
diverse labelings faster than a popular method of Batra et al., which in some
sense only obtains approximate solutions.


title: Modelling the nuclear parton distributions

abstract:
  We review a semi-microscopic model of nuclear parton distributions, which
takes into account a number of nuclear effects including Fermi motion and
nuclear binding, nuclear meson-exchange currents and off-shell corrections to
bound nucleon distributions as well as nuclear shadowing effect. We also
discuss applications of the model to the lepton-nuclear deep-inelastic
scattering, Drell-Yan process and neutrino total cross sections.


title:
On Takens' Last Problem: tangencies and time averages near heteroclinic
  networks

abstract:
  We obtain a structurally stable family of smooth ordinary differential
equations exhibiting heteroclinic tangencies for a dense subset of parameters.
We use this to find vector fields $C^2$-close to an element of the family
exhibiting a tangency, for which the set of solutions with historic behaviour
contains an open set. This provides an affirmative answer to Taken's Last
Problem (F. Takens (2008) Nonlinearity, 21(3) T33--T36). A limited solution
with historic behaviour is one for which the time averages do not converge as
time goes to infinity. Takens' problem asks for dynamical systems where
historic behaviour occurs persistently for initial conditions in a set with
positive Lebesgue measure.
  The family appears in the unfolding of a degenerate differential equation
whose flow has an asymptotically stable heteroclinic cycle involving
two-dimensional connections of non-trivial periodic solutions. We show that the
degenerate problem also has historic behaviour, since for an open set of
initial conditions starting near the cycle, the time averages approach the
boundary of a polygon whose vertices depend on the centres of gravity of the
periodic solutions and their Floquet multipliers.
  We illustrate our results with an explicit example where historic behaviour
arises $C^2$-close of a $\textbf{SO(2)}$-equivariant vector field.


title: Absolute continuity of stable foliations for mappings of Banach spaces

abstract:
  We prove the absolute continuity of stable foliations for mappings of Banach
spaces satisfying conditions consistent with time-t maps of certain classes of
dissipative PDEs. This property is crucial for passing information from
submanifolds transversal to the stable foliation to the rest of the phase
space; it is also used in proofs of ergodicity. Absolute continuity of stable
foliations is well known in finite dimensional hyperbolic theory. On Banach
spaces, the absence of nice geometric properties poses some additional
difficulties.


title:
The area integral and boundary values of octonion-valued monogenic
  functions

abstract:
  We introduce the Area Integral for octonion-valued monogenic functions in the
half-space. It is used to prove the existence of the non-tangential boundary
values almost everywhere and of the normal boundary values at a given boundary
point for these classes of functions. It is also proved that the non-tangential
limit for the scalar component of a monogenic function and those limits for all
of its other seven components exist or not exist simultaneously. It turns out
that non-commutativity and non-associativity of octonions in certain problems
can be circumvented by making use of P. Stein method and employing subharmonic
functions.


title: Low-loss single-mode integrated waveguides in soda-lime glass

abstract:
  Low-loss single-mode optical waveguide fabrication process in extra-white
soda-lime glass is demonstrated. Waveguiding structures are formed in bulk
substrates employing femtosecond laser writing technology. The combination of a
slit beam-shaping method and a multiscan fabrication process enables printing
of waveguides with a well-defined symmetric cross-section profile. Fabricated
waveguides exhibit 0.86 dB/cm propagation loss for 800~nm wavelength. Bending
loss in the waveguides are addressed experimentally and compared with a model
for radiation loss.


title:
Taming the divergent terms that occur during adiabatic switching in
  perturbation theory

abstract:
  A potential problem with adiabatic switching in perturbation theory is that
divergent terms appear in the series solution. An example of this was presented
by C. Brouder et al [4] for a simple 2 state system where the evolution of
system in the presence of a time dependent perturbation was considered. One of
their results is that the evolution operator has no well-defined limit for
adiabatic switching. We will rework this problem to show that for adiabatic
switching the evolved states are well-defined with any divergences being
absorbed in a time independent phase factor which can be removed. These results
will then be applied to the more general problem of a system with an arbitrary
number of states. It will be shown that for this case, also, the potentially
divergent terms all appear in a time-independent phase factor.


title: Moment convergence of balanced P\'olya processes

abstract:
  It is known that in an irreducible small P\'olya urn process, the composition
of the urn after suitable normalization converges in distribution to a normal
distribution. We show that if the urn also is balanced, this normal convergence
holds with convergence of all moments, thus giving asymptotics of (central)
moments.


title: A Special Theorem Related to the Fagnano's Problem

abstract:
  A special theorem related to the Fagnano's problem is proved and an example
of the theorem is shown in a golden rectangle.


title: Autoantibody recognition mechanisms of MUC1

abstract:
  The most cost-effective blood-based, noninvasive molecular cancer biomarkers
are based on p53 epitopes and MUC1 tandem repeats. Here we use dimensionally
compressed bioinformatic fractal scaling analysis to compare the two distinct
and comparable probes, which examine different sections of the autoantibody
population, achieving combined sensitivities of order 50%. We discover a
promising MUC1 epitope in the SEA region outside the tandem repeats.


title: Efficient Attack Graph Analysis through Approximate Inference

abstract:
  Attack graphs provide compact representations of the attack paths that an
attacker can follow to compromise network resources by analysing network
vulnerabilities and topology. These representations are a powerful tool for
security risk assessment. Bayesian inference on attack graphs enables the
estimation of the risk of compromise to the system's components given their
vulnerabilities and interconnections, and accounts for multi-step attacks
spreading through the system. Whilst static analysis considers the risk posture
at rest, dynamic analysis also accounts for evidence of compromise, e.g. from
SIEM software or forensic investigation. However, in this context, exact
Bayesian inference techniques do not scale well. In this paper we show how
Loopy Belief Propagation - an approximate inference technique - can be applied
to attack graphs, and that it scales linearly in the number of nodes for both
static and dynamic analysis, making such analyses viable for larger networks.
We experiment with different topologies and network clustering on synthetic
Bayesian attack graphs with thousands of nodes to show that the algorithm's
accuracy is acceptable and converge to a stable solution. We compare sequential
and parallel versions of Loopy Belief Propagation with exact inference
techniques for both static and dynamic analysis, showing the advantages of
approximate inference techniques to scale to larger attack graphs.


title:
"Dark" systems in globular clusters: GWs emission and limits on the
  formation of IMBHs

abstract:
  Many observed globular clusters (GCs) seem to show a central overabundance of
mass whose nature has not yet fully understood. Indeed, it is not clear whether
it is due to a central intermediate mass black hole (IMBH) or to a massive
stellar system (MSS) composed of mass segregated stars. In this contribution we
present a semi-analytic approach to the problem complemented by 12 $N$-body
simulations in which we followed the formation of MSSs in GCs with masses up to
$3\times 10^5$ \Ms. Some implications for the formation of IMBHs and
gravitational waves emission are discussed in perspective of a future work.


title:
Modeling Stellar Proton Event-induced particle radiation dose on
  close-in exoplanets

abstract:
  Kepler observations have uncovered the existence of a large number of
close-in exoplanets and serendipitously of stellar superflares with emissions
several orders of magnitude higher than those observed on the Sun. The
interaction between the two and its implications on planetary habitability is
of great interest to the community. Stellar Proton Events interact with
planetary atmospheres, generate secondary particles and increase the radiation
dose on the surface. This effect is amplified for close-in exoplanets and can
be a serious threat to potential planetary life. Monte Carlo simulations are
used to model the SPE-induced particle radiation dose on the surface of such
exoplanets. The results show a wide range of surface radiation doses on planets
in close-in configurations with varying atmospheric column depths, magnetic
moments and orbital radii. It can be concluded that for close-in exoplanets
with sizable atmospheres and magnetospheres, the radiation dose contributed by
stellar superflares may not be high enough to sterilize a planet (for life as
we know it) but can result in frequent extinction level events. In light of
recent reports, the interaction of hard-spectrum SPEs with the atmosphere of
Proxima Centauri b is modeled and implications on its habitability is
discussed.


title:
The inflow signature toward different evolutionary phases of massive
  star formation

abstract:
  We analyzed both HCN J=1-0 and HNC J=1-0 line profiles to study the inflow
motions in different evolutionary stages of massive star formation: 54 infrared
dark clouds (IRDCs), 69 high-mass protostellar object (HMPOs), and 54
ultra-compact HII regions (UCHIIs). The inflow asymmetry in HCN spectra seems
to be prevalent throughout all the three evolutionary phases, with IRDCs
showing the largest excess in blue profile. In the case of HNC spectra, the
prevalence of blue sources does not appear, excepting for IRDCs. We suggest
that this line is not appropriate to trace inflow motion in evolved stages of
massive star formation because the abundance of HNC decreases at high
temperatures. This result spotlights the importance of considering chemistry in
the dynamics study of massive star-forming regions. The fact that the IRDCs
show the highest blue excess in both transitions indicates that the most active
inflow occurs in the early phase of star formation, i.e., the IRDC phase rather
than in the later phases. However, mass is still inflowing onto some UCHIIs. We
also found that the absorption dips of the HNC spectra in 6 out of 7 blue
sources are red-shifted relative to their systemic velocities. These
red-shifted absorption dips may indicate global collapse candidates, although
mapping observations with better resolution are needed to examine this feature
in more detail.


title: Sparse convolutional coding for neuronal ensemble identification

abstract:
  Cell ensembles, originally proposed by Donald Hebb in 1949, are subsets of
synchronously firing neurons and proposed to explain basic firing behavior in
the brain. Despite having been studied for many years no conclusive evidence
has been presented yet for their existence and involvement in information
processing such that their identification is still a topic of modern research,
especially since simultaneous recordings of large neuronal population have
become possible in the past three decades. These large recordings pose a
challenge for methods allowing to identify individual neurons forming cell
ensembles and their time course of activity inside the vast amounts of spikes
recorded. Related work so far focused on the identification of purely simulta-
neously firing neurons using techniques such as Principal Component Analysis.
In this paper we propose a new algorithm based on sparse convolution coding
which is also able to find ensembles with temporal structure. Application of
our algorithm to synthetically generated datasets shows that it outperforms
previous work and is able to accurately identify temporal cell ensembles even
when those contain overlapping neurons or when strong background noise is
present.


title:
Conductance in inhomogeneous quantum wires: Luttinger liquid predictions
  and quantum Monte Carlo results

abstract:
  We study electron and spin transport in interacting quantum wires contacted
by noninteracting leads. We theoretically model the wire and junctions as an
inhomogeneous chain where the parameters at the junction change on the scale of
the lattice spacing. We study such systems analytically in the appropriate
limits based on Luttinger liquid theory and compare the results to quantum
Monte Carlo calculations of the conductances and local densities near the
junction. We first consider an inhomogeneous spinless fermion model with a
nearest-neighbor interaction and then generalize our results to a spinful model
with an onsite Hubbard interaction.


title:
Criteria on group G for Goldie theorems to be true for all G-graded
  rings

abstract:
  We present two criteria for a group $G$ to satisfy the following statements:
any $G$-graded gr-prime (gr-semiprime) right gr-Goldie ring admits a
gr-semisimple graded right classical quotient ring. The criterion for
gr-semiprime rings is that the group $G$ is periodic. Actually, the sufficiency
of periodicity was proved by the author in 2011 and the necessity of it follows
from the well-known counterexample (1979). The main result of the paper
concerns the gr-prime case. In this case, Goodearl and Stafford proved the
graded version of Goldie's Theorem for rings graded by an Abelian group (2000).
Developing their idea we extend the class of groups to the following: $(\forall
g,h\in G)(\exists n\in \mathbb{N})(gh^n=h^ng)$. Moreover, for any group $G$
outside this class, we construct a counterexample, precisely, a~$G$-graded ring
$R$ such that $Q^{gr}_{cl}(R)=R$ is gr-Noetherian but not gr-Artinian.


title: Stable Postnikov data of Picard 2-categories

abstract:
  Picard 2-categories are symmetric monoidal 2-categories with invertible 0-,
1-, and 2-cells. The classifying space of a Picard 2-category $\mathcal{D}$ is
an infinite loop space, the zeroth space of the $K$-theory spectrum
$K\mathcal{D}$. This spectrum has stable homotopy groups concentrated in levels
0, 1, and 2. In this paper, we describe part of the Postnikov data of
$K\mathcal{D}$ in terms of categorical structure. We use this to show that
there is no strict skeletal Picard 2-category whose $K$-theory realizes the
2-truncation of the sphere spectrum. As part of the proof, we construct a
categorical suspension, producing a Picard 2-category $\Sigma C$ from a Picard
1-category $C$, and show that it commutes with $K$-theory in that $K\Sigma C$
is stably equivalent to $\Sigma K C$.


title: Alternating Montesinos knots and Conjecture $\mathbb{Z}$

abstract:
  Conjecture $\mathbb{Z}$ is a knot theoretical equivalent form of the Kervaire
Conjecture. We say that a knot have property $\mathbb{Z}$ if it satisfies
Conjecture $\mathbb{Z}$ for that specific knot. In this work, we show that
alternating Montesinos knots with three tangles have property $\mathbb{Z}$. We
also show that all the pretzel knots of the form $P(p,q,r)$ (not necessarily
alternating) have property $\mathbb{Z}$.


title: The log-Sobolev inequality with quadratic interactions

abstract:
  We assume one site measures without a boundary $e^{-\phi(x)}dx/Z$ that
satisfy a log-Sobolev inequality. We prove that if these measures are perturbed
with quadratic interactions, then the associated infinite dimensional Gibbs
measure on the lattice always satisfies a log-Sobolev inequality. Furthermore,
we present examples of measures that satisfy the inequality with a phase that
goes beyond convexity at infinity.


title: Ancestral Causal Inference

abstract:
  Constraint-based causal discovery from limited data is a notoriously
difficult challenge due to the many borderline independence test decisions.
Several approaches to improve the reliability of the predictions by exploiting
redundancy in the independence information have been proposed recently. Though
promising, existing approaches can still be greatly improved in terms of
accuracy and scalability. We present a novel method that reduces the
combinatorial explosion of the search space by using a more coarse-grained
representation of causal information, drastically reducing computation time.
Additionally, we propose a method to score causal predictions based on their
confidence. Crucially, our implementation also allows one to easily combine
observational and interventional data and to incorporate various types of
available background knowledge. We prove soundness and asymptotic consistency
of our method and demonstrate that it can outperform the state-of-the-art on
synthetic data, achieving a speedup of several orders of magnitude. We
illustrate its practical feasibility by applying it on a challenging protein
data set.


title:
When Does Spatial Correlation Add Value to Delayed Channel State
  Information?

abstract:
  Fast fading wireless networks with delayed knowledge of the channel state
information have received significant attention in recent years. An exception
is networks where channels are spatially correlated. This paper characterizes
the capacity region of two-user erasure interference channels with delayed
knowledge of the channel state information and spatially correlated channels.
There are instances where spatial correlation eliminates any potential gain
from delayed channel state information and instances where it enables the same
performance that is possible with instantaneous knowledge of channel state. The
key is an extremal entropy inequality for spatially correlated channels that
separates the two types of instances. It is also shown that to achieve the
capacity region, each transmitter only needs to rely on the delayed knowledge
of the channels to which it is connected.


title: The Origin of Chaos in the Orbit of Comet 1P/Halley

abstract:
  According to Munoz-Gutierrez et al. (2015) the orbit of comet 1P/Halley is
chaotic with a surprisingly small Lyapunov time scale of order its orbital
period. In this work we analyse the origin of chaos in Halley's orbit and the
growth of perturbations, in order to get a better understanding of this
unusually short time scale. We perform N-body simulations to model Halley's
orbit in the Solar System and measure the separation between neighbouring
trajectories. To be able to interpret the numerical results, we use a
semi-analytical map to demonstrate different growth modes, i.e. linear,
oscillatory or exponential, and transitions between these modes. We find the
Lyapunov time scale of Halley's orbit to be of order 300 years, which is
significantly longer than previous estimates in the literature. This
discrepancy could be due to the different methods used to measure the Lyapunov
time scale. A surprising result is that next to Jupiter, also encounters with
Venus contribute to the exponential growth in the next 3000 years. Finally, we
note an interesting application of the sub-linear, oscillatory growth mode to
an ensemble of bodies moving through the Solar System. Whereas in the absence
of encounters with a third body the ensemble spreads out linearly in time, the
accumulation of weak encounters can increase the lifetime of such systems due
to the oscillatory behaviour.


title:
Twists of Mukai bundles and the geometry of the level $3$ modular
  variety over $\overline{\mathcal{M}}_8$

abstract:
  For a curve $C$ of genus $6$ or $8$ and a torsion bundle $\eta$ of order
$\ell$ we study the vanishing of the space of global sections of the twist $E_C
\otimes \eta$ of the rank two Mukai bundle $E_C$ of $C$. The bundle $E_C$ was
used in a well-known construction of Mukai which exhibits general canonical
curves of low genus as sections of Grassmannians in the Pl\"ucker embedding.
  Globalizing the vanishing condition, we obtain divisors on the moduli spaces
$\overline{\mathcal{R}}_{6,\ell}$ and $\overline{\mathcal{R}}_{8,\ell}$ of
pairs $[C, \eta]$. First we characterize these divisors by different conditions
on linear series on the level curves, afterwards we calculate the divisor
classes. As an application, we are able to prove that
$\overline{\mathcal{R}}_{8,3}$ is of general type.


title:
Science Impacts of the SPHEREx All-Sky Optical to Near-Infrared Spectral
  Survey: Report of a Community Workshop Examining Extragalactic, Galactic,
  Stellar and Planetary Science

abstract:
  SPHEREx is a proposed SMEX mission selected for Phase A. SPHEREx will carry
out the first all-sky spectral survey and provide for every 6.2" pixel a
spectra between 0.75 and 4.18 $\mu$m [with R$\sim$41.4] and 4.18 and 5.00
$\mu$m [with R$\sim$135]. The SPHEREx team has proposed three specific science
investigations to be carried out with this unique data set: cosmic inflation,
interstellar and circumstellar ices, and the extra-galactic background light.
It is readily apparent, however, that many other questions in astrophysics and
planetary sciences could be addressed with the SPHEREx data. The SPHEREx team
convened a community workshop in February 2016, with the intent of enlisting
the aid of a larger group of scientists in defining these questions. This paper
summarizes the rich and varied menu of investigations that was laid out. It
includes studies of the composition of main belt and Trojan/Greek asteroids;
mapping the zodiacal light with unprecedented spatial and spectral resolution;
identifying and studying very low-metallicity stars; improving stellar
parameters in order to better characterize transiting exoplanets; studying
aliphatic and aromatic carbon-bearing molecules in the interstellar medium;
mapping star formation rates in nearby galaxies; determining the redshift of
clusters of galaxies; identifying high redshift quasars over the full sky; and
providing a NIR spectrum for most eROSITA X-ray sources. All of these
investigations, and others not listed here, can be carried out with the nominal
all-sky spectra to be produced by SPHEREx. In addition, the workshop defined
enhanced data products and user tools which would facilitate some of these
scientific studies. Finally, the workshop noted the high degrees of synergy
between SPHEREx and a number of other current or forthcoming programs,
including JWST, WFIRST, Euclid, GAIA, K2/Kepler, TESS, eROSITA and LSST.


title:
Novel constraints on fermionic dark matter from galactic observables I:
  The Milky Way

abstract:
  We have recently introduced a new model for the distribution of dark matter
(DM) in galaxies based on a self-gravitating system of massive fermions at
finite temperatures, the Ruffini-Arg\"uelles-Rueda (RAR) model. We show that
this model, for fermion masses in the keV range, explains the DM halo of the
Galaxy and predicts the existence of a denser quantum core at the center. We
demonstrate here that the introduction of a cutoff in the fermion phase-space
distribution, necessary to account for the finite Galaxy size, defines a new
solution with a central core which represents an alternative to the black hole
(BH) scenario for SgrA*. For a fermion mass in the range $mc^2 = 48$ --
$345$~keV, the DM halo distribution is in agreement with the Milky Way rotation
curve data, while harbors a dense quantum core of about $4\times10^6 M_\odot$
within the S2-star pericenter.


title:
Covariant theory of Bose-Einstein condensates in curved spacetimes with
  electromagnetic interactions: the hydrodynamic approach

abstract:
  We develop a hydrodynamic representation of the Klein-Gordon-Maxwell-Einstein
equations. These equations combine quantum mechanics, electromagnetism, and
general relativity. We consider the case of an arbitrary curved spacetime, the
case of weak gravitational fields in a static or expanding background, and the
nonrelativistic (Newtonian) limit. The Klein-Gordon-Maxwell-Einstein equations
govern the evolution of a complex scalar field, possibly describing
self-gravitating Bose-Einstein condensates, coupled to an electromagnetic
field. They may find applications in the context of dark matter, boson stars,
and neutron stars with a superfluid core.


title:
Incentivizing Evaluation via Limited Access to Ground Truth:
  Peer-Prediction Makes Things Worse

abstract:
  In many settings, an effective way of evaluating objects of interest is to
collect evaluations from dispersed individuals and to aggregate these
evaluations together. Some examples are categorizing online content and
evaluating student assignments via peer grading. For this data science problem,
one challenge is to motivate participants to conduct such evaluations carefully
and to report them honestly, particularly when doing so is costly. Existing
approaches, notably peer-prediction mechanisms, can incentivize truth telling
in equilibrium. However, they also give rise to equilibria in which agents do
not pay the costs required to evaluate accurately, and hence fail to elicit
useful information. We show that this problem is unavoidable whenever agents
are able to coordinate using low-cost signals about the items being evaluated
(e.g., text labels or pictures). We then consider ways of circumventing this
problem by comparing agents' reports to ground truth, which is available in
practice when there exist trusted evaluators---such as teaching assistants in
the peer grading scenario---who can perform a limited number of unbiased (but
noisy) evaluations. Of course, when such ground truth is available, a simpler
approach is also possible: rewarding each agent based on agreement with ground
truth with some probability, and unconditionally rewarding the agent otherwise.
Surprisingly, we show that the simpler mechanism achieves stronger incentive
guarantees given less access to ground truth than a large set of
peer-prediction mechanisms.


title:
Toward Interpretable Topic Discovery via Anchored Correlation
  Explanation

abstract:
  Many predictive tasks, such as diagnosing a patient based on their medical
chart, are ultimately defined by the decisions of human experts. Unfortunately,
encoding experts' knowledge is often time consuming and expensive. We propose a
simple way to use fuzzy and informal knowledge from experts to guide discovery
of interpretable latent topics in text. The underlying intuition of our
approach is that latent factors should be informative about both correlations
in the data and a set of relevance variables specified by an expert.
Mathematically, this approach is a combination of the information bottleneck
and Total Correlation Explanation (CorEx). We give a preliminary evaluation of
Anchored CorEx, showing that it produces more coherent and interpretable topics
on two distinct corpora.


title:
Magnetic Lenz lenses increase the limit-of-detection in nuclear magnetic
  resonance

abstract:
  A high NMR detection sensitivity is indispensable when dealing with mass and
volume-limited samples, or whenever a high spatial resolution is required. The
use of miniaturised RF coils is a proven way to increase sensitivity, but may
be impractical and is not applicable to every experimental situation. We
present the use of magnetic lenses, denoted as Lenz lenses due to their working
principle, to focus the magnetic flux of a macroscopic RF coil into a smaller
volume and thereby locally enhance the sensitivity of the NMR experiment - at
the expense of the total sensitive volume. Besides focusing, such lenses
facilitate re-guiding or re-shaping of magnetic fields much like optical lenses
do with light beams. For the first time we experimentally demonstrate the use
of Lenz lenses in magnetic resonance and provide a compact mathematical
description of the working principle. Through simulations we show that optimal
arrangements can be found.


title: Evading the non-continuity equation in the f(R, T) formalism

abstract:
  We present a new approach for the $f(R,T)$ formalism, by exploring the extra
terms of its effective energy-momentum tensor $T_{\mu\nu}^{eff}$, namely
$\tilde{T}_{\mu\nu}$. Those arise from the consideration of quantum effects,
which are usually neglected in general relativity and $f(R)$ theories, and are
summed to the usual matter energy-momentum tensor, yielding
$T_{\mu\nu}^{eff}=T_{\mu\nu}+\tilde{T}_{\mu\nu}$. Purely from the Bianchi
identities, the conservation of both parts of the effective energy-momentum
tensor is obtained, rather than the non-conservation of the matter one,
originally approached in the $f(R,T)$ theories. In this way, the intriguing
scenario of matter-creation, which still lacks observational evidences, is
evaded. One is left, then, with two sets of cosmological equations to be
solved: the Friedmann-like equations along with the conservation of
$T_{\mu\nu}$ and along with the conservation of $\tilde{T}_{\mu\nu}$. We
present a physical interpretation for the conservation of the extra terms of
the effective energy-momentum tensor, which is related to the presence of stiff
matter in the universe. The cosmological features of this approach are
presented and discussed as well as the benefits of evading the matter
energy-momentum tensor non-conservation.


title:
Semantic Parsing to Probabilistic Programs for Situated Question
  Answering

abstract:
  Situated question answering is the problem of answering questions about an
environment such as an image or diagram. This problem requires jointly
interpreting a question and an environment using background knowledge to select
the correct answer. We present Parsing to Probabilistic Programs (P3), a novel
situated question answering model that can use background knowledge and global
features of the question/environment interpretation while retaining efficient
approximate inference. Our key insight is to treat semantic parses as
probabilistic programs that execute nondeterministically and whose possible
executions represent environmental uncertainty. We evaluate our approach on a
new, publicly-released data set of 5000 science diagram questions,
outperforming several competitive classical and neural baselines.


title: Deciding Hyperproperties

abstract:
  Hyperproperties, like observational determinism or symmetry, cannot be
expressed as properties of individual computation traces, because they describe
a relation between multiple computation traces. HyperLTL is a temporal logic
that captures such relations through trace variables, which are introduced
through existential and universal trace quantifiers and can be used to refer to
multiple computations at the same time. In this paper, we study the
satisfiability problem of HyperLTL. We show that the problem is PSPACE-complete
for alternation-free formulas (and, hence, no more expensive than LTL
satisfiability), EXPSPACE-complete for exists-forall-formulas, and undecidable
for forall-exists-formulas. Many practical hyperproperties can be expressed as
alternation-free formulas. Our results show that both satisfiability and
implication are decidable for such properties.


title:
An example of a map which is $C^2$ robustly transitive but not $C^1$
  (robustly transitive)

abstract:
  The aim of this work is to exhibit an example of an endomorphism of $\T^{2}$
which is $C^2$-robustly transitive but not $C^1$-robustly transitive.


title:
Axial, Scalar and Tensor Charges of the Nucleon from 2+1+1-flavor
  Lattice QCD

abstract:
  We present results for the isovector axial, scalar and tensor charges
$g^{u-d}_A$, $g^{u-d}_S$ and $g^{u-d}_T$ of the nucleon needed to probe the
Standard Model and novel physics. The axial charge is a fundamental parameter
describing the weak interactions of nucleons. The scalar and tensor charges
probe novel interactions at the TeV scale in neutron and nuclear
$\beta$-decays, and the flavor-diagonal tensor charges $g^{u}_T$, $g^{d}_T$ and
$g^{s}_T$ are needed to quantify the contribution of the quark electric dipole
moment (EDM) to the neutron EDM. The 9 ensembles, generated by the MILC
Collaboration using the HISQ action with 2+1+1 dynamical flavors, span three
lattice spacings $a \approx 0.06, 0.09$ and 0.12 fm and light-quark masses
corresponding to the pion masses $M_\pi \approx 135, 225$ and 315 MeV.
High-statistics estimates on five ensembles using the all-mode-averaging method
allow us to quantify all systematic uncertainties and perform a simultaneous
extrapolation in the lattice spacing, lattice volume and light-quark masses for
the connected contributions. Our final estimates, in the $\overline{\text{MS}}$
scheme at 2 GeV, of the isovector charges are $g_A^{u-d} = 1.195(33)(20)$,
$g_S^{u-d} = 0.97(12)(6) $ and $g_T^{u-d} = 0.987(51)(20)$. The first error
includes statistical and all systematic uncertainties except that due to the
extrapolation Ansatz, which is given by the second error estimate. Combining
our estimate for $g_S^{u-d}$ with the difference of light quarks masses
$(m_d-m_u)^{\rm QCD}=2.67(35)$ MeV given by FLAG, we obtain $(M_N-M_P)^{\rm
QCD} = 2.59(49)$ MeV. Estimates of the connected part of the flavor-diagonal
tensor charges of the proton are $g^{u}_T=0.792(42)$ and $g^{d}_T=-0.194(14)$.
Combining our new estimates with precision low-energy experiments, we update
constraints on novel scalar and tensor interactions, $\epsilon_{S,T}$, at the
TeV scale.


title: A complete knot invariant from contact homology

abstract:
  We construct an enhanced version of knot contact homology, and show that we
can deduce from it the group ring of the knot group together with the
peripheral subgroup. In particular, it completely determines a knot up to
smooth isotopy. The enhancement consists of the (fully noncommutative)
Legendrian contact homology associated to the union of the conormal torus of
the knot and a disjoint cotangent fiber sphere, along with a product on a
filtered part of this homology. As a corollary, we obtain a new,
holomorphic-curve proof of a result of the third author that the Legendrian
isotopy class of the conormal torus is a complete knot invariant.


title:
Kondo effect from a Lorentz-violating domain wall description of
  superconductivity

abstract:
  We extend recent results on domain wall description of superconductivity in
an Abelian Higgs model by introducing a particular Lorentz-violating term. The
temperature of the system is interpreted through the fact that the soliton
following accelerating orbits is a Rindler observer experiencing a thermal
bath. We show that this term can be associated with the {\sl Kondo effect},
that is, the Lorentz-violating parameter is closely related to the
concentration of magnetic impurities living on a superconducting domain wall.
We also found that the critical temperature decreasing with the impurity
concentration as a non single-valued function, for the case $T_K < T_{c0}$,
develops a negative curvature and presents deviations from the Abrikosov and
Gor'kov theory, a phenomenon already supported by experimental evidence.


title: On the wellposedness of the defocusing mKdV equation below $L^{2}$

abstract:
  We prove that the renormalized defocusing mKdV equation on the circle is
locally in time $C^{0}$-wellposed on the Fourier Lebesgue space
${\mathcal{F}\ell}^p$ for any $2 < p < \infty$. The result implies that the
defocusing mKdV equation itself is illposed on these spaces since the
renormalizing phase factor becomes infinite. The proof is based on the fact
that the mKdV equation is an integrable PDE whose Hamiltonian is in the NLS
hierarchy. A key ingredient is a novel way of representing the bi-infinite
sequence of frequencies of the renormalized defocusing mKdV equation, allowing
to analytically extend them to ${\mathcal{F}\ell}^p$ for any $2 \le p < \infty$
and to deduce asymptotics for $n \to \pm \infty$.


title: Uniform Distribution of Eigenstates on a Torus with Two Point Scatterers

abstract:
  We study the Laplacian perturbed by two delta potentials on a two-dimensional
flat torus. There are two types of eigenfunctions for this operator: old, or
unperturbed eigenfunctions which are eigenfunctions of the standard Laplacian,
and new, perturbed eigenfunctions which are affected by the scatterers. We
prove that along a density one sequence, the new eigenfunctions are uniformly
distributed in configuration space, provided that the difference of the
scattering points is Diophantine.


title:
Single and two-mode mechanical squeezing of an optically levitated
  nanodiamond via dressed-state coherence

abstract:
  Nonclassical states of macroscopic objects are promising for ultrasensitive
metrology as well as testing quantum mechanics. In this work, we investigate
dissipative mechanical quantum state engineering in an optically levitated
nanodiamond. First, we study single-mode mechanical squeezed states by
magnetically coupling the mechanical motion to a dressed three-level system
provided by a Nitrogen-vacancy center in the nanoparticle. Quantum coherence
between the dressed levels is created via microwave fields to induce a
two-phonon transition, which results in mechanical squeezing. Remarkably, we
find that in ultrahigh vacuum quantum squeezing is achievable at room
temperature with feedback cooling. For moderate vacuum, quantum squeezing is
possible with cryogenic temperature. Second, we present a setup for two
mechanical modes coupled to the dressed three levels, which results in two-mode
squeezing analogous to the mechanism of the single-mode case. In contrast to
previous works, our study provides a deterministic method for engineering
macroscopic squeezed states without the requirement for a cavity.


title:
Dimension of the SLE light cone, the SLE fan, and SLE$_\kappa(\rho)$ for
  $\kappa \in (0,4)$ and $\rho \in [\tfrac{\kappa}{2}-4,-2)$

abstract:
  Suppose that $h$ is a Gaussian free field (GFF) on a planar domain. Fix
$\kappa \in (0,4)$. The SLE$_\kappa$ light cone ${\mathbf L}(\theta)$ of $h$
with opening angle $\theta \in [0,\pi]$ is the set of points reachable from a
given boundary point by angle-varying flow lines of the (formal) vector field
$e^{i h/\chi}$, $\chi = \tfrac{2}{\sqrt{\kappa}} - \tfrac{\sqrt{\kappa}}{2}$,
with angles in $[-\tfrac{\theta}{2},\tfrac{\theta}{2}]$. We derive the
Hausdorff dimension of ${\mathbf L}(\theta)$.
  If $\theta =0$ then ${\mathbf L}(\theta)$ is an ordinary SLE$_{\kappa}$ curve
(with $\kappa < 4$); if $\theta = \pi$ then ${\mathbf L}(\theta)$ is the range
of an SLE$_{\kappa'}$ curve ($\kappa' = 16/\kappa > 4$). In these extremes,
this leads to a new proof of the Hausdorff dimension formula for SLE.
  We also consider SLE$_\kappa(\rho)$ processes, which were originally only
defined for $\rho > -2$, but which can also be defined for $\rho \leq -2$ using
L\'evy compensation. The range of an SLE$_\kappa(\rho)$ is qualitatively
different when $\rho \leq -2$. In particular, these curves are
self-intersecting for $\kappa < 4$ and double points are dense, while ordinary
SLE$_\kappa$ is simple. It was previously shown (Miller-Sheffield, 2016) that
certain SLE$_\kappa(\rho)$ curves agree in law with certain light cones.
Combining this with other known results, we obtain a general formula for the
Hausdorff dimension of SLE$_\kappa(\rho)$ for all values of $\rho$.
  Finally, we show that the Hausdorff dimension of the so-called SLE$_\kappa$
fan is the same as that of ordinary SLE$_\kappa$.


title:
Emulating Human Conversations using Convolutional Neural Network-based
  IR

abstract:
  Conversational agents ("bots") are beginning to be widely used in
conversational interfaces. To design a system that is capable of emulating
human-like interactions, a conversational layer that can serve as a fabric for
chat-like interaction with the agent is needed. In this paper, we introduce a
model that employs Information Retrieval by utilizing convolutional deep
structured semantic neural network-based features in the ranker to present
human-like responses in ongoing conversation with a user. In conversations,
accounting for context is critical to the retrieval model; we show that our
context-sensitive approach using a Convolutional Deep Structured Semantic Model
(cDSSM) with character trigrams significantly outperforms several conventional
baselines in terms of the relevance of responses retrieved.


title:
Dumbbell Defects in FeSe Films: A Scanning Tunneling Microscopy and
  First-Principles Investigation

abstract:
  The properties of iron-based superconductors (Fe-SCs) can be varied
dramatically with the introduction of dopants and atomic defects. As a pressing
example, FeSe, parent phase of the highest-$T_c$ Fe-SC, exhibits prevalent
defects with atomic-scale "dumbbell" signatures as imaged by scanning tunneling
microscopy (STM). These defects spoil superconductivity when their
concentration exceeds 2.5%. Resolving their chemical identity is prerequisite
to applications such as nanoscale patterning of
superconducting/nonsuperconducting regions in FeSe, as well as fundamental
questions such as the mechanism of superconductivity and the path by which the
defects destroy it. We use STM and density functional theory to characterize
and identify the dumbbell defects. In contrast to previous speculations about
Se adsorbates or substitutions, we find that an Fe-site vacancy is the most
energetically favorable defect in Se-rich conditions, and reproduces our
observed STM signature. Our calculations shed light more generally on the
nature of Se capping, the removal of Fe vacancies via annealing, and their
ordering into a $\sqrt{5}$$\times$$\sqrt{5}$ superstructure in FeSe and related
alkali-doped compounds.


title:
The quantum 1/2 BPS Wilson loop in ${\cal N}=4$ Chern-Simons-matter
  theories

abstract:
  In three dimensional ${\cal N}=4$ Chern-Simons-matter theories two
independent fermionic Wilson loop operators can be defined, which preserve half
of the supersymmetry charges and are cohomologically equivalent at classical
level. We compute their three-loop expectation value in a convenient color
sector and prove that the degeneracy is uplifted by quantum corrections. We
expand the matrix model prediction in the same regime and by comparison we
conclude that the quantum 1/2 BPS Wilson loop is the average of the two
operators. We provide an all-loop argument to support this claim at any order.
As a by-product, we identify the localization result at three loops as a
correction to the framing factor induced by matter interactions. Finally, we
comment on the quantum properties of the non-1/2 BPS Wilson loop operator
defined as the difference of the two fermionic ones.


title: Can transition radiation explain the ANITA event 3985267?

abstract:
  We investigate whether transition radiation from a particle shower crossing
the interface between Earth and air and induced by an Earth-skimming neutrino
can explain the upward event announced recently by the ANITA Collaboration.
While the properties of the observed signal can in principle be explained with
transition radiation, the flux necessary for a successful explanation is in
tension with the current best limits from the Pierre Auger Observatory, the
IceCube neutrino detector and the ANITA balloon. We also show that in this
scenario, the direction of the incoming neutrino is determined precisely to
within a few degrees, from the polarization properties of the observed events
and thanks to the Earth opacity to ultra high energy neutrinos.


title:
Bell's Nonlocality Can be Detected by the Violation of
  Einstein-Podolsky-Rosen Steering Inequality

abstract:
  Recently quantum nonlocality has been classified into three distinct types:
quantum entanglement, Einstein-Podolsky-Rosen steering, and Bell's nonlocality.
Among which, Bell's nonlocality is the strongest type. Bell's nonlocality for
quantum states is usually detected by violation of some Bell's inequalities,
such as Clause-Horne-Shimony-Holt inequality for two qubits. Steering is a
manifestation of nonlocality intermediate between entanglement and Bell's
nonlocality. This peculiar feature has led to a curious quantum phenomenon, the
one-way Einstein-Podolsky-Rosen steering. The one-way steering was an important
open question presented in 2007, and positively answered in 2014 by Bowles
\emph{et al.}, who presented a simple class of one-way steerable states in a
two-qubit system with at least thirteen projective measurements. The inspiring
result for the first time theoretically confirms quantum nonlocality can be
fundamentally asymmetric. Here, we propose another curious quantum phenomenon:
Bell nonlocal states can be constructed from some steerable states. This novel
finding not only offers a distinctive way to study Bell's nonlocality without
Bell's inequality but with steering inequality, but also may avoid locality
loophole in Bell's tests and make Bell's nonlocality easier for demonstration.
Furthermore, a nine-setting steering inequality has also been presented for
developing more efficient one-way steering and detecting some Bell nonlocal
states.


title:
Large-scale retrospective relative spectro-photometric self-calibration
  in space

abstract:
  We consider the application of relative self-calibration using overlap
regions to spectroscopic galaxy surveys that use slit-less spectroscopy. This
method is based on that developed for the SDSS by Padmanabhan at al. (2008) in
that we consider jointly fitting and marginalising over calibrator brightness,
rather than treating these as free parameters. However, we separate the
calibration of the detector-to-detector from the full-focal-plane
exposure-to-exposure calibration. To demonstrate how the calibration procedure
will work, we simulate the procedure for a potential implementation of the
spectroscopic component of the wide Euclid survey. We study the change of
coverage and the determination of relative multiplicative errors in flux
measurements for different dithering configurations. We use the new method to
study the case where the flat-field across each exposure or detector is
measured precisely and only exposure-to-exposure or detector-to-detector
variation in the flux error remains. We consider several base dither patterns
and find that they strongly influence the ability to calibrate, using this
methodology. To enable self-calibration, it is important that the survey
strategy connects different observations with at least a minimum amount of
overlap, and we propose an "S"-pattern for dithering that fulfills this
requirement. The final survey strategy adopted by Euclid will have to optimise
for a number of different science goals and requirements. The large-scale
calibration of the spectroscopic galaxy survey is clearly cosmologically
crucial, but is not the only one.


title: Merging WW and WW+jet with MINLO

abstract:
  We present a simulation program for the production of a pair of W bosons in
association with a jet, that can be used in conjunction with general-purpose
shower Monte Carlo generators, according to the POWHEG method. We have further
adapted and implemented the MINLO' method on top of the NLO calculation
underlying our WW+jet generator. Thus, the resulting simulation achieves NLO
accuracy not only for inclusive distributions in WW+jet production but also WW
production, i.e. when the associated jet is not resolved, without the
introduction of any unphysical merging scale. This work represents the first
extension of the MINLO' method, in its original form, to the case of a genuine
underlying 2->2 process, with non-trivial virtual corrections.


title: Jet substructure using semi-inclusive jet functions within SCET

abstract:
  We propose a new method to evaluate jet substructure observables in inclusive
jet measurements, based upon semi-inclusive jet functions in the framework of
Soft Collinear Effective Theory (SCET). As a first example, we consider the jet
fragmentation function, where a hadron $h$ is identified inside a fully
reconstructed jet. We introduce a new semi-inclusive fragmenting jet function
${\mathcal G}^h_i(z= \omega_J/\omega,z_h=\omega_h/\omega_J,\omega_J, R,\mu)$,
which depends on the jet radius $R$ and the large light-cone momenta of the
parton `$i$' initiating the jet ($\omega$), the jet ($\omega_J$), and the
hadron $h$ ($\omega_h$). The jet fragmentation function can then be expressed
as a semi-inclusive observable, in the spirit of actual experimental
measurements, rather than as an exclusive one. We demonstrate the consistency
of the effective field theory treatment and standard perturbative QCD
calculations of this observable at next-to-leading order (NLO). The
renormalization group (RG) equation for the semi-inclusive fragmenting jet
function ${\mathcal G}_i^h(z,z_h, \omega_J, R,\mu)$ are also derived and shown
to follow exactly the usual timelike DGLAP evolution equations for
fragmentation functions. The newly obtained RG equations can be used to perform
the resummation of single logarithms of the jet radius parameter $R$ up to
next-to-leading logarithmic (NLL$_R$) accuracy. In combination with the fixed
NLO calculation, we obtain NLO+NLL$_R$ results for the hadron distribution
inside the jet. We present numerical results for $pp\to(\mathrm{jet}\,h)X$ in
the new framework, and find excellent agreement with existing LHC experimental
data.


title: Collinear scattering of photoexcited carriers in graphene

abstract:
  We propose an explicitly solvable model for collinear scattering of
photoexcited carriers in intrinsic graphene irradiated by monochromatic light.
We find that the collinear scattering rate is directly proportional to the
photocarrier energy and derive an analytic expression for the corresponding
relaxation time. The result agrees with the recent numerical prediction [Mihnev
et al. Nat. Commun. vol. 7, 11617 (2016)] and is able to describe the
photocarrier evolution at low energies, where scattering on optical phonons is
strongly suppressed.


title: Gas absorption and dust extinction towards the Orion Nebula Cluster

abstract:
  We characterise the relation between the gas and dust content of the
interstellar medium towards young stellar objects in the Orion Nebula Cluster.
X-ray observations provide estimates of the absorbing equivalent hydrogen
column density N_H based on spectral fits. Near-infrared extinction values are
calculated from intrinsic and observed colour magnitudes (J-H) and (H-K_s) as
given by the VISTA Orion A survey. A linear fit of the correlation between
column density and extinction values A_V yields an estimate of the N_H/A_V
ratio. We investigate systematic uncertainties of the results by describing and
(if possible) quantifying the influence of circumstellar material and the
adopted extinction law, X-ray models, and elemental abundances on the N_H/A_V
ratio. Assuming a Galactic extinction law with R_V=3.1 and solar abundances by
Anders & Grevesse (1989), we deduce an N_H/A_V ratio of (1.39 +- 0.14) x 10^21
cm^-2 mag^-1 for Class III sources in the Orion Nebula Cluster where the given
error does not include systematic uncertainties. This ratio is consistent with
similar studies in other star-forming regions and approximately 31% lower than
the Galactic value. We find no obvious trends in the spatial distribution of
N_H/A_V ratios. Changes in the assumed extinction law and elemental abundances
are demonstrated to have a relevant impact on deduced A_V and N_H values,
respectively. Large systematic uncertainties associated with metal abundances
in the Orion Nebula Cluster represent the primary limitation for the deduction
of a definitive N_H/A_V ratio and the physical interpretation of these results.


title:
Dark matter concentrations in galactic nuclei according to polytropic
  models

abstract:
  We calculate the radial profiles of galaxies where the nuclear region is
self-gravitating, consisting of self-interacting dark matter (SIDM) with $F$
degrees of freedom. For sufficiently high density this dark matter becomes
collisional, regardless of its behaviour on galaxy scales. Our calculations
show a spike in the central density profile, with properties determined by the
dark matter microphysics, and the densities can reach the `mean density' of a
black hole (from dividing the black-hole mass by the volume enclosed by the
Schwarzschild radius). For a galaxy halo of given compactness
($\chi=2GM/Rc^2$), certain values for the dark matter entropy yield a dense
central object lacking an event horizon. For some soft equations of state of
the SIDM (e.g. $F\ge6$), there are multiple horizonless solutions at given
compactness. Although light propagates around and through a sphere composed of
dark matter, it is gravitationally lensed and redshifted. While some
calculations give non-singular solutions, others yield solutions with a central
singularity. In all cases the density transitions smoothly from the central
body to the dark-matter envelope around it, and to the galaxy's dark matter
halo. We propose that pulsar timing observations will be able to distinguish
between systems with a centrally dense dark matter sphere (for different
equations of state) and conventional galactic nuclei that harbour a
supermassive black hole.

categories: astro-ph.GA astro-ph.CO astro-ph.HE gr-qc


title: Stability of $SU(N_c)$ QCD3 from the $\epsilon$-Expansion

abstract:
  QCD with gauge group $SU(N_c)$ flows to an interacting conformal fixed point
in three spacetime dimensions when the number of four-component Dirac fermions
$N_f \gg N_c$. We study the stability of this fixed point via the
$\epsilon$-expansion about four dimensions. We find that when the number of
fermions is lowered to $N_f^{\rm crit} \approx {11 \over 2} N_c + (6 + {4 \over
N_c}) \epsilon$, a certain four-fermion operator becomes relevant and the
theory flows to a new infrared fixed point (massless or massive). F-theorem or
entanglement monotonicity considerations complement our $\epsilon$-expansion
calculation.


title: Debris Disks in the Scorpius-Centaurus OB Association Resolved by ALMA

abstract:
  We present a CO(2-1) and 1240 um continuum survey of 23 debris disks with
spectral types B9-G1, observed at an angular resolution of 0.5-1 arcsec with
the Atacama Large Millimeter/Submillimeter Array (ALMA). The sample was
selected for large infrared excess and age ~10 Myr, to characterize the
prevalence of molecular gas emission in young debris disks. We identify three
CO-rich debris disks, plus two additional tentative (3-sigma) CO detections.
Twenty disks were detected in the continuum at the >3-sigma level. For the 12
disks in the sample that are spatially resolved by our observations, we perform
an independent analysis of the interferometric continuum visibilities to
constrain the basic dust disk geometry, as well as a simultaneous analysis of
the visibilities and broad-band spectral energy distribution to constrain the
characteristic grain size and disk mass. The gas-rich debris disks exhibit
preferentially larger outer radii in their dust disks, and a higher prevalence
of characteristic grain sizes smaller than the blowout size. The gas-rich disks
do not exhibit preferentially larger dust masses, contrary to expectations for
a scenario in which a higher cometary destruction rate would be expected to
result in a larger mass of both CO and dust. The three debris disks in our
sample with strong CO detections are all around A stars: the conditions in
disks around intermediate-mass stars appear to be the most conducive to the
survival or formation of CO.


title: All one-loop scalar vertices in the effective potential approach

abstract:
  Using the one-loop Coleman-Weinberg effective potential, we derive a general
analytic expression for all the derivatives of the effective potential with
respect to any number of classical scalar fields. The result is valid for a
renormalisable theory in four dimensions with any number of scalars, fermions
or gauge bosons. This result corresponds to the zero-external momentum
contribution to a general one-loop diagram with N scalar external legs. We
illustrate the use of the general result in two simple scalar singlet
extensions of the Standard Model, to obtain the dominant contributions to the
triple couplings of light scalar particles under the zero external momentum
approximation


title: Twisted sectors from plane partitions

abstract:
  Twisted sectors arise naturally in the bosonic higher spin CFTs at their free
points, as well as in the associated symmetric orbifolds. We identify the coset
representations of the twisted sector states using the description of W_\infty
representations in terms of plane partitions. We confirm these proposals by a
microscopic null-vector analysis, and by matching the excitation spectrum of
these representations with the orbifold prediction.


title: Global Seismology of the Sun

abstract:
  The seismic study of the Sun and other stars offers a unique window into the
interior of these stars. Thanks to helioseismology, we know the structure of
the Sun to admirable precision. In fact, our knowledge is good enough to use
the Sun as a laboratory. We have also been able to study the dynamics of the
Sun in great detail. Helioseismic data also allow us to probe the changes that
take place in the Sun as solar activity waxes and wanes. The seismic study of
stars other than the Sun is a fairly new endeavour, but we are making great
strides in this field. In this review I discuss some of the techniques used in
helioseismic analyses and the results obtained using those techniques. In this
review I focus on results obtained with global helioseismology, i.e., the study
of the Sun using its normal modes of oscillation. I also briefly touch upon
asteroseismology, the seismic study of stars other than the Sun, and discuss
how seismic data of others stars are interpreted.


title: Edge pseudo-magnetoplasmons

abstract:
  We study the properties of edge plasmons in two-component electron liquids in
the presence of pseudomagnetic fields, which have opposite signs for the two
different electronic populations and therefore preserve the time-reversal
symmetry. The physical realizations of such systems are many. We discuss the
cases of strained graphene and of electrons in proximity to a Skyrmion lattice,
solving the problem with the Wiener-Hopf technique. We show (i) that two
charged counter-propagating acoustic edge modes exist at the boundary and (ii)
that, in the limit of large pseudomagnetic fields, each of them involves
oscillations of only one of the two electronic components. We suggest that the
edge pseudo-magnetoplasmons of graphene can be used to selectively address the
electrons of one specific valley, a feature relevant for the emerging field of
valleytronics. Conversely, the spin-polarized plasmons at the boundary of
Skyrmion lattices can be exploited for spintronics applications. Our solution
highlights new features missing in previous (similar) results obtained with
uncontrolled approximations, namely a logarithmic divergence of the plasmon
velocity, and the absence of gapped edge modes inside the bulk-plasmon gap.


title:
Lyman-Alpha Emitter Galaxies at z ~ 2.8 in the Extended Chandra Deep
  Field-South: I. Tracing the Large-Scale Structure via Lyman-Alpha Imaging

abstract:
  We present a narrowband survey with three adjacent filters for z=2.8--2.9
Lyman Alpha Emitter (LAE) galaxies in the Extended Chandra Deep Field South
(ECDFS), along with spectroscopic followup. With a complete sample of 96 LAEs
in the narrowband NB466, we confirm a large-scale structure at z~ 2.8. Compared
to the blank field in NB470 and NB475, the LAE density excess in the NB466
field is ~6.0+/-0.8 times the standard deviation expected at z~2.8, assuming a
linear bias of 2. The overdense large scale structure in NB466 can be
decomposed into 4 protoclusters, whose overdensities are 4.6 - 6.6. These 4
protoclusters are expected to evolve into a Coma-like cluster at z~ 0. In the
meanwhile, we investigate the average star-formation rates derived from
Ly{\alpha}, rest-frame UV and X-ray, the Ly{\alpha} luminosity functions, the
Ly{\alpha} photon densities and their dependence on the environment. We find
that the Ly{\alpha} photon density in the overdense field (NB466) is ~50\%
higher than that in the blank field (NB470+NB475). The 3 brightest LAEs,
including a quasar at z=2.81, are all detected in X-ray and in NB466. These
three LAE-AGNs contribute an extra 20--30\% Ly{\alpha} photon density.
Furthermore, we find that LAEs in overdense regions are younger and less dusty.
We conclude that the structure we found is a significant and rare density peak,
and narrowband imaging is an efficient method to detect and study such
structures in the high-z universe.


title:
First-principles mode-by-mode analysis for electron-phonon scattering
  channels and mean free path spectra in GaAs

abstract:
  We present a first-principles framework to investigate the electron
scattering channels and transport properties for polar material by combining
the exact solution of linearized electron-phonon (e-ph) Boltzmann transport
equation in its integral-differential form associated with the e-ph coupling
matrices obtained from polar Wannier interpolation scheme. No ad hoc parameter
is required throughout this calculation, and GaAs, a well-studied polar
material, is used as an example to demonstrate this method. In this work, the
long-range and short-range contributions as well as the intravalley and
intervalley transitions in the e-ph interactions (EPIs) have been
quantitatively addressed. Promoted by such mode-by-mode analysis, we find that
in GaAs, the piezoelectric scattering is comparable to deformation-potential
scattering for electron scatterings by acoustic phonons in EPI even at room
temperature and makes a significant contribution to mobility. Furthermore, we
achieved good agreements with experimental data for the mobility, and
identified that electrons with mean free paths between 130 and 210 nm
contribute dominantly to the electron transport at 300 K. Such information
provides deeper understandings on the electron transport in GaAs, and the
presented framework can be readily applied to other polar materials.


title: Strange Quark Magnetic Moment of the Nucleon at Physical Point

abstract:
  We report a lattice QCD calculation of the strange quark contribution to the
nucleon's magnetic moment and charge radius. This analysis presents the first
direct determination of strange electromagnetic form factors including at the
physical pion mass. We perform a model-independent extraction of the strange
magnetic moment and the strange charge radius from the electromagnetic form
factors in the momentum transfer range of $0.051 \,\text{GeV}^2 \lesssim Q^2
\lesssim 1.31 \,\text{GeV}^2 $. The finite lattice spacing and finite volume
corrections are included in a global fit with $24$ valence quark masses on four
lattices with different lattice spacings, different volumes, and four sea quark
masses including one at the physical pion mass. We obtain the strange magnetic
moment $G^s_M(0) = - 0.064(14)(09)\, \mu_N$. The four-sigma precision in
statistics is achieved partly due to low-mode averaging of the quark loop and
low-mode substitution to improve the statistics of the nucleon propagator. We
also obtain the strange charge radius $\langle r_s^2\rangle_E = -0.0043
(16)(14)\,$ $\text{fm}^2$.


title: Quantum Entanglement of Locally Excited States in Maxwell Theory

abstract:
  In 4 dimensional Maxwell gauge theory, we study the changes of (Renyi)
entangle-ment entropy which are defined by subtracting the entropy for the
ground state from the one for the locally excited states generated by acting
with the gauge invariant local operators on the state. The changes for the
operators which we consider in this paper reflect the electric-magnetic
duality. The late-time value of changes can be interpreted in terms of
electromagnetic quasi-particles. When the operator constructed of both electric
and magnetic fields acts on the ground state, it shows that the operator acts
on the late-time structure of quantum entanglement differently from free scalar
fields.


title:
A Portrait of Cold Gas in Galaxies at 60pc Resolution and a Simple
  Method to Test Hypotheses That Link Small-Scale ISM Structure to Galaxy-Scale
  Processes

abstract:
  The cloud-scale density, velocity dispersion, and gravitational boundedness
of the interstellar medium (ISM) vary within and among galaxies. In turbulent
models, these properties play key roles in the ability of gas to form stars.
New high fidelity, high resolution surveys offer the prospect to measure these
quantities across galaxies. We present a simple approach to make such
measurements and to test hypotheses that link small-scale gas structure to star
formation and galactic environment. Our calculations capture the key physics of
the Larson scaling relations, and we show good correspondence between our
approach and a traditional "cloud properties" treatment. However, we argue that
our method is preferable in many cases because of its simple, reproducible
characterization of all emission. Using, low-J 12CO data from recent surveys,
we characterize the molecular ISM at 60pc resolution in the Antennae, the Large
Magellanic Cloud, M31, M33, M51, and M74. We report the distributions of
surface density, velocity dispersion, and gravitational boundedness at 60pc
scales and show galaxy-to-galaxy and intra-galaxy variations in each. The
distribution of flux as a function of surface density appears roughly lognormal
with a 1sigma width of ~0.3 dex, though the center of this distribution varies
from galaxy to galaxy. The 60pc resolution line width and molecular gas surface
density correlate well, which is a fundamental behavior expected for virialized
or free-falling gas. Varying the measurement scale for the LMC and M31, we show
that the molecular ISM has higher surface densities, lower line widths, and
more self-gravity at smaller scales.


title: Bagger-Witten line bundles on moduli spaces of elliptic curves

abstract:
  In this paper we discuss Bagger-Witten line bundles over moduli spaces of
SCFTs. We review how in general they are `fractional' line bundles, not honest
line bundles, twisted on triple overlaps. We discuss the special case of moduli
spaces of elliptic curves in detail. There, the Bagger-Witten line bundle does
not exist as an ordinary line bundle, but rather is necessarily fractional. As
a fractional line bundle, it is nontrivial (though torsion) over the
uncompactified moduli stack, and its restriction to the interior, excising
corners with enhanced stabilizers, is also fractional. It becomes an honest
line bundle on a moduli stack defined by a quotient of the upper half plane by
a metaplectic group, rather than SL(2,Z). We review and compare to results of
recent work arguing that well-definedness of the worldsheet metric implies that
the Bagger-Witten line bundle admits a flat connection (which includes torsion
bundles as special cases), and give general arguments on the existence of
universal structures on moduli spaces of SCFTs, in which superconformal
deformation parameters are promoted to nondynamical fields ranging over the
SCFT moduli space.


title: SICS: Secure In-Cloud Service Function Chaining

abstract:
  There is an increasing trend that enterprises outsource their network
functions to the cloud for lower cost and ease of management. However, network
function outsourcing brings threats to the privacy of enterprises since the
cloud is able to access the traffic and rules of in-cloud network functions.
Current tools for secure network function outsourcing either incur large
performance overhead or do not support real-time updates. In this paper, we
present SICS, a secure service function chain outsourcing framework. SICS
encrypts each packet header and use a label for in-cloud rule matching, which
enables the cloud to perform its functionalities correctly with minimum header
information leakage. Evaluation results show that SICS achieves higher
throughput, faster construction and update speed, and lower resource overhead
at both enterprise and cloud sides, compared to existing solutions.


title: Domain Name System Security and Privacy: Old Problems and New Challenges

abstract:
  The domain name system (DNS) is an important protocol in today's Internet
operation, and is the standard naming convention between domain names, names
that are easy to read, understand, and remember by humans, to IP address of
Internet resources. The wealth of research activities on DNS in general and
security and privacy in particular suggest that all problems in this domain are
solved. Reality however is that despite the large body of literature on various
aspects of DNS, there are still many challenges that need to be addressed. In
this paper, we review the various activities in the research community on DNS
operation, security, and privacy, and outline various challenges and open
research directions that need to be tackled.


title: Finite Sample Prediction and Recovery Bounds for Ordinal Embedding

abstract:
  The goal of ordinal embedding is to represent items as points in a
low-dimensional Euclidean space given a set of constraints in the form of
distance comparisons like "item $i$ is closer to item $j$ than item $k$".
Ordinal constraints like this often come from human judgments. To account for
errors and variation in judgments, we consider the noisy situation in which the
given constraints are independently corrupted by reversing the correct
constraint with some probability. This paper makes several new contributions to
this problem. First, we derive prediction error bounds for ordinal embedding
with noise by exploiting the fact that the rank of a distance matrix of points
in $\mathbb{R}^d$ is at most $d+2$. These bounds characterize how well a
learned embedding predicts new comparative judgments. Second, we investigate
the special case of a known noise model and study the Maximum Likelihood
estimator. Third, knowledge of the noise model enables us to relate prediction
errors to embedding accuracy. This relationship is highly non-trivial since we
show that the linear map corresponding to distance comparisons is
non-invertible, but there exists a nonlinear map that is invertible. Fourth,
two new algorithms for ordinal embedding are proposed and evaluated in
experiments.


title: The phenomenology of the di-photon excess and $h\to\tau\mu$ within 2HDM

abstract:
  The diphoton excess around $m_S=750$ GeV observed at ATLAS and CMS can be
interpreted as coming from $S=H$ and $A$, the neutral components of a second
Higgs doublet. If so, then the consistency of the light Higgs decays with the
Standard Model predictions provides upper bounds on the rates of $S\to VV, hZ,
hh$ decays. On the other hand, if $h\to\tau\mu$ decay is established, then a
lower bound on the rate of $S\to\tau\mu$ decay arises. Requiring that
$\Gamma_S\lesssim45$ GeV gives both an upper and a lower bound on the rotation
angle from the Higgs basis $(\Phi_v,\Phi_A)$ to the mass basis
$(\Phi_h,\Phi_H)$. The charged scalar, with $m_{H^\pm}\simeq750$ GeV, is
produced in association with a top quark, and can decay to $\mu^\pm\nu$,
$\tau^\pm\nu$, $tb$ and $W^\pm h$


title: Lovelock gravities from Born-Infeld gravity theory

abstract:
  We present a Born-Infeld gravity theory based on generalizations of Maxwell
symmetries denoted as $\mathfrak{C}_{m}$. We analyze different configuration
limits allowing to recover diverse Lovelock gravity actions in six dimensions.
Further, the generalization to higher even dimensions is also considered.


title: Proving relations between modular graph functions

abstract:
  We consider modular graph functions that arise in the low energy expansion of
the four graviton amplitude in type II string theory. The vertices of these
graphs are the positions of insertions of vertex operators on the toroidal
worldsheet, while the links are the scalar Green functions connecting the
vertices. Graphs with four and five links satisfy several non--trivial
relations, which have been proved recently. We prove these relations by using
elementary properties of Green functions and the details of the graphs. We also
prove a relation between modular graph functions with six links.


title:
From NoSQL Accumulo to NewSQL Graphulo: Design and Utility of Graph
  Algorithms inside a BigTable Database

abstract:
  Google BigTable's scale-out design for distributed key-value storage inspired
a generation of NoSQL databases. Recently the NewSQL paradigm emerged in
response to analytic workloads that demand distributed computation local to
data storage. Many such analytics take the form of graph algorithms, a trend
that motivated the GraphBLAS initiative to standardize a set of matrix math
kernels for building graph algorithms. In this article we show how it is
possible to implement the GraphBLAS kernels in a BigTable database by
presenting the design of Graphulo, a library for executing graph algorithms
inside the Apache Accumulo database. We detail the Graphulo implementation of
two graph algorithms and conduct experiments comparing their performance to two
main-memory matrix math systems. Our results shed insight into the conditions
that determine when executing a graph algorithm is faster inside a database
versus an external system---in short, that memory requirements and relative I/O
are critical factors.


title:
Collider and Dark Matter Searches in the Inert Doublet Model from
  Peccei-Quinn Symmetry

abstract:
  Weakly Interacting Massive Particles (WIMPs) and axions are arguably the most
compelling dark matter candidates in the literature. Could they coexist as dark
matter particles? More importantly, can they be incorporated in a well
motivated framework in agreement with experimental data? In this work, we show
that this two component dark matter can be realized in the Inert Doublet Model
in an elegant and natural manner by virtue of the spontaneous breaking of a
Peccei-Quinn $U(1)_{PQ}$ symmetry into a residual $Z_2$ symmetry. The WIMP
stability is guaranteed by the $Z_{2}$ symmetry and a new dark matter
component, the axion, arises. There are two interesting outcomes: (i)
vector-like quarks needed to implement the Peccei-Quinn symmetry in the model
act as a portal between the dark sector and the SM fields with a
supersymmetry-type phenomenology at colliders; (ii) two-component Inert Doublet
Model re-opens the phenomenologically interesting 100-500 GeV mass region. We
show that the model can plausibly have two component dark matter and at the
same time avoid low and high energy physics constraints such as monojet and
dijet plus missing energy, as well as indirect and direct dark matter detection
bounds.


title:
Constraining the mass of the planet(s) sculpting a disk cavity. The
  intriguing case of 2MASS J16042165-2130284

abstract:
  The large cavities observed in the dust and gas distributions of transition
disks may be explained by planet-disk interactions. At ~145 pc, 2MASS
J16042165-2130284 (J1604) is a 5-12 Myr old transitional disk with different
gap sizes in the mm- and $\mu$m-sized dust distributions (outer edges at ~79
and at ~63 au, respectively). Its $^{12}$CO emission shows a ~30 au cavity.
This radial structure suggests that giant planets are sculpting this disk. We
aim to constrain the masses and locations of plausible giant planets around
J1604. We observed J1604 with the Spectro-Polarimetric High-contrast Exoplanet
REsearch (SPHERE) at the Very Large Telescope (VLT), in IRDIFS\_EXT,
pupil-stabilized mode, obtaining YJH- band images with the integral field
spectrograph (IFS) and K1K2-band images with the Infra-Red Dual-beam Imager and
Spectrograph (IRDIS). The dataset was processed exploiting the angular
differential imaging (ADI) technique with high-contrast algorithms. Our
observations reach a contrast of $\Delta K, YH$ ~12 mag from 0.15" to 0.80"
(~22 to 115 au), but no planet candidate is detected. The disk is directly
imaged in scattered light at all bands from Y to K, and it shows a red color.
This indicates that the dust particles in the disk surface are mainly
$\gtrsim0.3\,\mu$m-sized grains. We confirm the sharp dip/decrement in
scattered light in agreement with polarized light observations. Comparing our
images with a radiative transfer model we argue that the southern side of the
disk is most likely the nearest. This work represents the deepest search yet
for companions around J1604. We reach a mass sensitivity of $\gtrsim
2-3M_{Jup}$ from ~22 to ~115 au according to a hot start scenario. We propose
that a brown dwarf orbiting inside of ~15 au and additional Jovian planets at
larger radii could account for the observed properties of J1604 while
explaining our lack of detection.


title: Revealing Hidden Connections in Recommendation Networks

abstract:
  Companies have been increasingly seeking new mechanisms for making their
electronic marketing campaigns to become viral, thus obtaining a cascading
recommendation effect similar to word-of-mouth. We analysed a dataset of a
magazine publisher that uses email as the main marketing strategy and found out
that networks emerging from those campaigns form a very sparse graph. We show
that online social networks can be effectively used as a means to expand
recommendation networks. Starting from a set of users, called seeders, we
crawled Google's Orkut and collected about 20 million users and 80 million
relationships. Next, we extended the original recommendation network by adding
new edges using Orkut relationships that built a much denser network.
Therefore, we advocate that online social networks are much more effective than
email-based marketing campaigns


title:
A Direct Determination of the Temperature of Overheated Electrons in an
  Insulator

abstract:
  Highly disordered superconductors, in the magnetic-field-driven insulating
state, can show discontinuous current-voltage characteristics. Electron
overheating has been shown to give a consistent description of this behavior,
but there are other, more exotic, explanations including a novel,
superinsulating state and a many-body localized state. We present AC-DC
crossed-measurements, in which the application of a DC voltage is applied along
our sample, while a small AC voltage is applied in the transverse direction. We
varied the DC voltage and observed a simultaneous discontinuity in both AC and
DC currents. We show that the inferred electron-temperature in the transverse
measurement matches that in the longitudinal one, strongly supporting electron
overheating as the source of observed current-voltage characteristics. Our
measurement technique may be applicable as a method of probing electron
overheating in many other physical systems, which show discontinuous or
non-linear current-voltage characteristics.


title: Dirac vs Majorana gauginos at a 100 TeV collider

abstract:
  We compare the prospects for observing theories with Majorana or Dirac
gauginos at a future 100 TeV proton-proton collider. Calculating the expected
discovery and exclusion regions, we find that for heavy gluino masses the
squark discovery reach is significantly reduced in Dirac gluino models relative
to the Majorana case. However, if the squark and gluino masses are close the
reach is similar in both scenarios. We also consider the electroweak fine
tuning of theories observable at such a collider, and the impact of existing
constraints from flavour and CP violating observables. Models with Majorana
gluinos that are fine tuned to less than one part in 10,000 can typically be
discovered or excluded, and Dirac models with tuning of one part in 1,000 can
be probed. The flavour structure of Majorana models is highly constrained if
they have observable squarks, while O(1) violation is possible in accessible
Dirac models. In both cases new sources of CP violation must be very
suppressed. Future collider searches can also give important information on
possible dark matter candidates. We study the relation of this to indirect and
direct detection searches, and find that if dark matter is a neutralino, a 100
TeV collider could probe the viable dark matter candidates in large classes of
both Dirac and Majorana models.


title: The formation and evolution of star clusters in interacting galaxies

abstract:
  Observations of globular clusters show that they have universal lognormal
mass functions with a characteristic peak at $\sim 2\times 10^{5}\,
{\rm{M_{\odot}}}$, but the origin of this peaked distribution is highly
debated. Here we investigate the formation and evolution of star clusters in
interacting galaxies using high-resolution hydrodynamical simulations performed
with two different codes in order to mitigate numerical artifacts. We find that
massive star clusters in the range of $\sim 10^{5.5} - 10^{7.5}\,
{\rm{M_{\odot}}}$ form preferentially in the highly-shocked regions produced by
galaxy interactions. The nascent cluster-forming clouds have high gas pressures
in the range of $P/k \sim 10^8 - 10^{12}\, \rm{K}\,\rm{cm^{-3}}$, which is
$\sim 10^4 - 10^8$ times higher than the typical pressure of the interstellar
medium but consistent with recent observations of a pre-super star cluster
cloud in the Antennae Galaxies. Furthermore, these massive star clusters have
quasi-lognormal initial mass functions with a peak around $\sim 10^{6}\,
{\rm{M_{\odot}}}$. The number of clusters declines with time due to destructive
processes, but the shape and the peak of the mass functions do not change
significantly during the course of galaxy collisions. Our results suggest that
gas-rich galaxy mergers may provide a favorable environment for the formation
of massive star clusters such as globular clusters, and that the lognormal mass
functions and the unique peak may originate from the extreme high-pressure
conditions of the birth clouds and may survive the dynamical evolution.


title: Artificial Fun: Mapping Minds to the Space of Fun

abstract:
  Yampolskiy and others have shown that the space of possible minds is vast,
actually infinite (Yampolskiy, 2015). A question of interest is 'Which
activities can minds perform during their lifetime?' This question is very
broad, thus in this article restricted to 'Which non-boring activities can
minds perform?' The space of potential non-boring activities has been called by
Yudkowsky 'fun space' (Yudkowsky, 2009). This paper aims to discuss the
relation between various types of minds and the part of the fun space, which is
accessible for them.


title:
On the Lebesgue Constant of Weighted Leja Points for Lagrange
  Interpolation on Unbounded Domains

abstract:
  This work focuses on weighted Lagrange interpolation on an unbounded domain,
and analyzes the Lebesgue constant for a sequence of weighted Leja points. The
standard Leja points are a nested sequence of points defined on a compact
subset of the real line, and can be extended to unbounded domains with the
introduction of a weight function $w:\mathbb{R}\rightarrow [0,1]$. Due to a
simple recursive formulation in one dimension, such abscissas provide a
foundation for high-dimensional approximation methods such as sparse grid
collocation, deterministic least squares, and compressed sensing. Just as in
the unweighted case of interpolation on a compact domain, we use results from
potential theory to prove that the Lebesgue constant for the Leja points grows
subexponentially with the number of interpolation nodes.


title: Sharp Adams-Moser-Trudinger type inequalities in the hyperbolic space

abstract:
  The purpose of this paper is to establish some Adams-Moser-Trudinger
inequalities, which are the borderline cases of the Sobolev embedding, in the
hyperbolic space $\mathbb H^n$. First, we prove a sharp Adams inequality of
order two with the exact growth condition in $\mathbb H^n$. Then we use it to
derive a sharp Adams-type inequality and an Adachi-Tanaka-type inequality. We
also prove a sharp Adams-type inequality with Navier boundary condition on any
bounded domain of $\mathbb H^n$, which generalizes the result of Tarsi to the
setting of hyperbolic spaces. Finally, we establish a Lions-type lemma and an
improved Adams-type inequality in the spirit of Lions in $\mathbb H^n$. Our
proofs rely on the symmetrization method extended to hyperbolic spaces.


title: Finding Proofs in Tarskian Geometry

abstract:
  We report on a project to use a theorem prover to find proofs of the theorems
in Tarskian geometry. These theorems start with fundamental properties of
betweenness, proceed through the derivations of several famous theorems due to
Gupta and end with the derivation from Tarski's axioms of Hilbert's 1899 axioms
for geometry. They include the four challenge problems left unsolved by Quaife,
who two decades ago found some \Otter proofs in Tarskian geometry (solving
challenges issued in Wos's 1998 book). There are 212 theorems in this
collection. We were able to find \Otter proofs of all these theorems. We
developed a methodology for the automated preparation and checking of the input
files for those theorems, to ensure that no human error has corrupted the
formal development of an entire theory as embodied in two hundred input files
and proofs. We distinguish between proofs that were found completely
mechanically (without reference to the steps of a book proof) and proofs that
were constructed by some technique that involved a human knowing the steps of a
book proof. Proofs of length 40--100, roughly speaking, are difficult exercises
for a human, and proofs of 100-250 steps belong in a Ph.D. thesis or
publication. 29 of the proofs in our collection are longer than 40 steps, and
ten are longer than 90 steps. We were able to derive completely mechanically
all but 26 of the 183 theorems that have "short" proofs (40 or fewer deduction
steps). We found proofs of the rest, as well as the 29 "hard" theorems, using a
method that requires consulting the book proof at the outset. Our "subformula
strategy" enabled us to prove four of the 29 hard theorems completely
mechanically. These are Ph.D. level proofs, of length up to 108.


title: The X-ray Pulsar M82 X-2 on its Propeller Line

abstract:
  {\it NuSTAR} has detected pulsations from the ultraluminous X-ray source X-2
in M82 and archival {\it Chandra} observations have given us a good idea of its
duty cycle. The newly discovered pulsar exhibited at least 4 super-Eddington
outbursts in the past 15 years but, in its lowest-power state, it radiates just
below the Eddington limit and its properties appear to be typical of high-mass
X-ray binaries. M82 X-2 has been described as a common neutron star with a 1~TG
magnetic field that occasionally accretes above the Eddington rate and as a
magnetar-like pulsar with a 10-100~TG magnetic field that reaches above the
quantum limit. We argue in favor of the former interpretation. Using standard
accretion theory and the available observations, we calculate the stellar
magnetic field of this pulsar in two independent ways and we show that it
cannot exceed 3~TG in either case. We discuss the implications of our results
for other ultraluminous X-ray sources that occasionally exhibit similar
powerful outbursts.


title:
$N-$body dynamics of Intermediate mass-ratio inspirals in globular
  clusters

abstract:
  The intermediate mass-ratio inspiral of a stellar compact remnant into an
intermediate mass black hole (IMBH) can produce a gravitational wave (GW)
signal that is potentially detectable by current ground-based GW detectors
(e.g., Advanced LIGO) as well as by planned space-based interferometers (e.g.,
eLISA). Here, we present results from a direct integration of the
post-Newtonian $N$-body equations of motion describing stellar clusters
containing an IMBH and a population of stellar-mass black holes (BHs) and solar
mass stars. We take particular care to simulate the dynamics closest to the
IMBH, including post-Newtonian effects up to order $2.5$. Our simulations show
that the IMBH readily forms a binary with a BH companion. This binary is
gradually hardened by transient 3-body or 4-body encounters, leading to
frequent substitutions of the BH companion, while the binary's eccentricity
experiences large amplitude oscillations due to the Lidov-Kozai resonance. We
also demonstrate suppression of these resonances by the relativistic precession
of the binary orbit. We find an intermediate mass-ratio inspiral in one of the
12 cluster models we evolved for $\sim 100$ Myr. This cluster hosts a $100
M_\odot$ IMBH embedded in a population of 32 $10M_\odot$ BH and 32,000
$1M_\odot$ stars. At the end of the simulation, after $\sim 100$ Myr of
evolution, the IMBH merges with a BH companion. The IMBH--BH binary inspiral
starts in the eLISA frequency window ($\gtrsim 1\rm mHz$) when the binary
reaches an eccentricity $1-e\simeq 10^{-3}$. After $\simeq 10^5$ years the
binary moves into the LIGO frequency band with a negligible eccentricity. We
comment on the implications for GW searches, with a possible detection within
the next decade.


title: Decoherence and the Branching of Chaos-less Classical Trajectory

abstract:
  This study was started to know mysterious classicality of nuclei.
  This time, I found a new rule for decoherence. I used a model without chaos.
As a result, it was shown that not only the intersection of classical
trajectories but also branching of classical trajectories are needed for
decoherence. In other words, it was shown that interactions between a main
system and environments have to make enough branchings of classical
trajectories of the main system for decoherence.


title:
Traffic dynamics on dynamical networks: The connection between network
  lifetime and traffic congestion

abstract:
  For many power-limited networks, such as wireless sensor networks and mobile
ad hoc networks, maximizing the network lifetime is the first concern in the
related designing and maintaining activities. We study the network lifetime
from the perspective of network science. In our dynamic network, nodes are
assigned a fixed amount of energy initially and consume the energy in the
delivery of packets. We divided the network traffic flow into four states: no,
slow, fast, and absolute congestion states. We derive the network lifetime by
considering the state of the traffic flow. We find that the network lifetime is
generally opposite to traffic congestion in that the more congested traffic,
the less network lifetime. We also find the impacts of factors such as packet
generation rate, communication radius, node moving speed, etc., on network
lifetime and traffic congestion.


title:
Fate of topological states in incommensurate generalized Aubry-Andr\'e
  models

abstract:
  We study one-dimensional optical lattices described by generalized
Aubry-Andr\'e models that include both commensurate and incommensurate
modulations of the hopping amplitude. This brings together two interesting
features of this class of systems: Anderson localization and the existence of
topological edge states. We follow changes of the single-particle energy
spectrum induced by variations of the system parameters, with focus on the
survival of topological states in the localized regime.


title:
Probing Many-Body Interactions in Monolayer Transition-Metal
  Dichalcogenides

abstract:
  Many-body interactions in monolayer transition-metal dichalcogenides are
strongly affected by their unique band structure. We study these interactions
by measuring the energy shift of neutral excitons (bound electron-hole pairs)
in gated WSe$_2$ and MoSe$_2$. Surprisingly, while the blueshift of the neutral
exciton, $X^0$, in electron-doped samples can be more than 10~meV, the
blueshift in hole-doped samples is nearly absent. Taking into account dynamical
screening and local-field effects, we present a transparent and analytical
model that elucidates the crucial role played by intervalley plasmons in
electron-doped conditions. The energy shift of $X^0$ as a function of charge
density is computed showing agreement with experiment, where the
renormalization of $X^0$ by intervalley plasmons yields a stronger blueshift in
MoSe$_2$ than in WSe$_2$ due to differences in their band ordering.


title:
Friends of Hot Jupiters. IV. Stellar companions beyond 50 AU might
  facilitate giant planet formation, but most are unlikely to cause Kozai-Lidov
  migration

abstract:
  Stellar companions can influence the formation and evolution of planetary
systems, but there are currently few observational constraints on the
properties of planet-hosting binary star systems. We search for stellar
companions around 77 transiting hot Jupiter systems to explore the statistical
properties of this population of companions as compared to field stars of
similar spectral type. After correcting for survey incompleteness, we find that
$47\%\pm7\%$ of hot Jupiter systems have stellar companions with semi-major
axes between 50-2000 AU. This is 2.9 times larger than the field star companion
fraction in this separation range, with a significance of $4.4\sigma$. In the
1-50AU range, only $3.9^{+4.5}_{-2.0}\%$ of hot Jupiters host stellar
companions compared to the field star value of $16.4\%\pm0.7\%$, which is a
$2.7\sigma$ difference. We find that the distribution of mass ratios for
stellar companions to hot Jupiter systems peaks at small values and therefore
differs from that of field star binaries which tend to be uniformly distributed
across all mass ratios. We conclude that either wide separation stellar
binaries are more favorable sites for gas giant planet formation at all
separations, or that the presence of stellar companions preferentially causes
the inward migration of gas giant planets that formed farther out in the disk
via dynamical processes such as Kozai-Lidov oscillations. We determine that
less than 20% of hot Jupiters have stellar companions capable of inducing
Kozai-Lidov oscillations assuming initial semi-major axes between 1-5 AU,
implying that the enhanced companion occurrence is likely correlated with
environments where gas giants can form efficiently.


title:
Deep Feature Fusion Network for Answer Quality Prediction in Community
  Question Answering

abstract:
  Community Question Answering (cQA) forums have become a popular medium for
soliciting direct answers to specific questions of users from experts or other
experienced users on a given topic. However, for a given question, users
sometimes have to sift through a large number of low-quality or irrelevant
answers to find out the answer which satisfies their information need. To
alleviate this, the problem of Answer Quality Prediction (AQP) aims to predict
the quality of an answer posted in response to a forum question. Current AQP
systems either learn models using - a) various hand-crafted features (HCF) or
b) use deep learning (DL) techniques which automatically learn the required
feature representations.
  In this paper, we propose a novel approach for AQP known as - "Deep Feature
Fusion Network (DFFN)" which leverages the advantages of both hand-crafted
features and deep learning based systems. Given a question-answer pair along
with its metadata, DFFN independently - a) learns deep features using a
Convolutional Neural Network (CNN) and b) computes hand-crafted features using
various external resources and then combines them using a deep neural network
trained to predict the final answer quality. DFFN achieves state-of-the-art
performance on the standard SemEval-2015 and SemEval-2016 benchmark datasets
and outperforms baseline approaches which individually employ either HCF or DL
based techniques alone.


title: Manifold Approximation by Moving Least-Squares Projection (MMLS)

abstract:
  In order to avoid the curse of dimensionality, frequently encountered in Big
Data analysis, there was a vast development in the field of linear and
nonlinear dimension reduction techniques in recent years. These techniques
(sometimes referred to as manifold learning) assume that the scattered input
data is lying on a lower dimensional manifold, thus the high dimensionality
problem can be overcome by learning the lower dimensionality behavior. However,
in real life applications, data is often very noisy. In this work, we propose a
method to approximate $\mathcal{M}$ a $d$-dimensional $C^{m+1}$ smooth
submanifold of $\mathbb{R}^n$ ($d \ll n$) based upon noisy scattered data
points (i.e., a data cloud). We assume that the data points are located "near"
the lower dimensional manifold and suggest a non-linear moving least-squares
projection on an approximating $d$-dimensional manifold. Under some mild
assumptions, the resulting approximant is shown to be infinitely smooth and of
high approximation order (i.e., $O(h^{m+1})$, where $h$ is the fill distance
and $m$ is the degree of the local polynomial approximation). The method
presented here assumes no analytic knowledge of the approximated manifold and
the approximation algorithm is linear in the large dimension $n$. Furthermore,
the approximating manifold can serve as a framework to perform operations
directly on the high dimensional data in a computationally efficient manner.
This way, the preparatory step of dimension reduction, which induces
distortions to the data, can be avoided altogether.