title:
Neutrino-induced one-pion production revisited: the $\nu_\mu n\to\mu^-
  n\pi^+$ channel

abstract:
  Understanding single pion production reactions on free nucleons is the first
step towards a correct description of these processes in nuclei, which are
important for signal and background contributions in current and near future
accelerator neutrino oscillation experiments. In this work, we reanalyze our
previous studies of neutrino-induced one-pion production on nucleons for
outgoing $\pi N$ invariant masses below 1.4 GeV. Our motivation is to get a
better description of the $\nu_\mu n\to\mu^- n\pi^+$ cross section, for which
current theoretical models give values significantly below data. This channel
is very sensitive to the crossed $\Delta (1232)$ contribution and thus to spin
1/2 components in the Rarita-Schwinger $\Delta$ propagator. We show how these
spin 1/2 components are nonpropagating and give rise to contact interactions.
In this context, we point out that the discrepancy with experiment might be
corrected by the addition of appropriate extra contact terms and argue that
this procedure will provide a natural solution to the $\nu_\mu n\to\mu^-
n\pi^+$ puzzle. To keep our model simple, in this work we propose to change the
strength of the spin 1/2 components in the $\Delta$ propagator and use the
$\nu_\mu n\to\mu^- n\pi^+$ data to constraint its value. With this
modification, we now find a good reproduction of the $\nu_\mu n\to\mu^- n\pi^+$
cross section without affecting the good results previously obtained for the
other channels. We also explore how this change in the $\Delta$ propagator
affects our predictions for pion photoproduction and find also a better
agreement with experiment than with the previous model.


title: Formation of coalition structures as a non-cooperative game 1: theory

abstract:
  The paper defines a non-cooperative simultaneous finite game to study
coalition structure formation with intra and inter-coalition externalities. The
novelty of the game is that the game definition embeds a \textit{coalition
structure formation mechanism}. This mechanism portions a set of strategies of
the game into partition-specific strategy domains, what makes every partition
to be a non-cooperative game with partition-specific payoffs for every player.
The mechanism includes a maximum coalition size, a set of eligible partitions
with coalitions sizes no greater than this number (which also serves as a
restriction for a maximum number of deviators) and a coalition structure
formation rule. The paper defines a family of nested non-cooperative games
parametrized by a size of a maximum coalition size. Every game in the family
has an equilibrium in mixed strategies. The equilibrium can generate more than
one coalition and encompasses intra and inter group externalities, what makes
it different from the Shapley value. Presence of individual payoff allocation
makes it different from a strong Nash, coalition-proof equilibrium, and some
other equilibrium concepts. The accompanying papers demonstrate applications of
the proposed toolkit.


title: Chemotaxis and Haptotaxis on Cellular Level

abstract:
  Chemotaxis and haptotaxis have been a main theme in the macroscopic study of
bacterial and cellular motility. In this work we investigate the influence
these processes have on the shape and motility of fast migrating cells. We note
that despite their biological and modelling differences, the cells exhibit many
similarities in their migration. We moreover see, that after an initial
adjustment phase, the cells obtain a stable shape and their motion is similar
to advection.


title: Quotient inductive-inductive types

abstract:
  Higher inductive types (HITs) in Homotopy Type Theory (HoTT) allow the
definition of datatypes which have constructors for equalities over the defined
type. HITs generalise quotient types and allow to define types which are not
sets in the sense of HoTT (i.e. do not satisfy uniqueness of equality proofs)
such as spheres, suspensions and the torus. However, there are also interesting
uses of HITs to define sets, such as the Cauchy reals, the partiality monad,
and the internal, total syntax of type theory. In each of these examples we
define several types that depend on each other mutually, i.e. they are
inductive-inductive definitions. We call those HITs quotient
inductive-inductive types (QIITs).
  Although there has been recent progress on the general theory of HITs, there
isn't yet a theoretical foundation of the combination of equality constructors
and induction-induction, despite having many interesting applications. In the
present paper we present a first step towards a semantic definition of QIITs.
In particular, we give an initial-algebra semantics and show that this is
equivalent to the section induction principle, which justifies the intuitively
expected elimination rules.


title: General quadrupolar statistical anisotropy: Planck limits

abstract:
  Several early Universe scenarios predict a direction-dependent spectrum of
primordial curvature perturbations. This translates into the violation of the
statistical isotropy of cosmic microwave background radiation. Previous
searches for statistical anisotropy mainly focussed on a quadrupolar
direction-dependence characterised by a single multipole vector and an overall
amplitude $g_*$. Generically, however, the quadrupole has a more complicated
geometry described by two multipole vectors and $g_*$. This is the subject of
the present work. In particular, we limit the amplitude $g_*$ for different
shapes of the quadrupole by making use of Planck 2015 maps. We also constrain
certain inflationary scenarios which predict this kind of more general
quadrupolar statistical anisotropy.


title: Lower solar atmosphere and magnetism at ultra-high spatial resolution

abstract:
  We present the scientific case for a future space-based telescope aimed at
very high spatial and temporal resolution imaging of the solar photosphere and
chromosphere. Previous missions (e.g., HINODE, SUNRISE) have demonstrated the
power of observing the solar photosphere and chromosphere at high spatial
resolution without contamination from Earth's atmosphere. We argue here that
increased spatial resolution (from currently 70 km to 25 km in the future) and
high temporal cadence of the observations will vastly improve our understanding
of the physical processes controlling solar magnetism and its characteristic
scales. This is particularly important as the Sun's magnetic field drives solar
activity and can significantly influence the Sun-Earth system. At the same time
a better knowledge of solar magnetism can greatly improve our understanding of
other astrophysical objects.


title: On the supersoluble residual of mutually permutable products

abstract:
  We prove that if a group $G=AB$ is the mutually permutable product of the
supersoluble subgroups $A$ and $B$, then the supersoluble residual of $G$
coincides with the nilpotent residual of the derived subgroup $G'$.


title:
An Information-theoretic Approach to Machine-oriented Music
  Summarization

abstract:
  Music summarization allows for higher efficiency in processing, storage, and
sharing of datasets. Machine-oriented approaches, being agnostic to human
consumption, optimize these aspects even further. Such summaries have already
been successfully validated in some MIR tasks. We now generalize previous
conclusions by evaluating the impact of generic summarization of music from a
probabilistic perspective. We estimate Gaussian distributions for original and
summarized songs and compute their relative entropy, in order to measure
information loss incurred by summarization. Our results suggest that relative
entropy is a good predictor of summarization performance in the context of
tasks relying on a bag-of-features model. Based on this observation, we further
propose a straightforward yet expressive summarizer, which minimizes relative
entropy with respect to the original song, that objectively outperforms
previous methods and is better suited to avoid potential copyright issues.


title: Phase-space representations of SIC-POVM fiducial states

abstract:
  The problem of finding symmetric informationally complete POVMs (SIC-POVMs)
has been solved numerically for all dimensions $d$ up to 67 (A.J. Scott and M.
Grassl, {\it J. Math. Phys.} 51:042203, 2010), but a general proof of existence
is still lacking. For each dimension, it was shown that it is possible to find
a SIC-POVM which is generated from a fiducial state upon application of the
operators of the Heisenberg-Weyl group. We draw on the numerically determined
fiducial states to study their phase-space features, as displayed by the
characteristic function and the Wigner, Bargmann and Husimi representations,
adapted to a Hilbert space of finite dimension. We analyze the phase-space
localization of fiducial states, and observe that the SIC-POVM condition is
equivalent to a maximal delocalization property. Finally, we explore the
consequences in phase space of the conjectured Zauner symmetry. In particular,
we construct an Hermitian operator commuting with this symmetry that leads to a
representation of fiducial states in terms of eigenfunctions with definite
semiclassical features.


title:
An Accelerated Composite Gradient Method for Large-scale Composite
  Objective Problems

abstract:
  We introduce a framework, which we denote as the augmented estimate sequence,
for deriving fast algorithms with provable convergence guarantees. We use this
framework to construct a new first-order scheme, the Accelerated Composite
Gradient Method (ACGM), for large-scale problems with composite objective
structure. ACGM surpasses the state-of-the-art methods for this problem class
in terms of provable convergence rate, both in the strongly and non-strongly
convex cases, and is endowed with an efficient step size search procedure. We
support the effectiveness of our new method with simulation results.


title: Efficient Certified RAT Verification

abstract:
  Clausal proofs have become a popular approach to validate the results of SAT
solvers. However, validating clausal proofs in the most widely supported format
(DRAT) is expensive even in highly optimized implementations. We present a new
format, called LRAT, which extends the DRAT format with hints that facilitate a
simple and fast validation algorithm. Checking validity of LRAT proofs can be
implemented using trusted systems such as the languages supported by theorem
provers. We demonstrate this by implementing two certified LRAT checkers, one
in Coq and one in ACL2.


title: On the adiabatic theorem when eigenvalues dive into the continuum

abstract:
  We consider a reduced two-channel model of an atom consisting of a quantum
dot coupled to an open scattering channel described by a three-dimensional
Laplacian. We are interested in the survival probability of a bound state when
the dot energy varies smoothly and adiabatically in time. The initial state
corresponds to a discrete eigenvalue which dives into the continuous spectrum
and re-emerges from it as the dot energy is varied in time and finally returns
to its initial value. Our main result is that for a large class of couplings,
the survival probability of this bound state vanishes in the adiabatic limit.
At the end of the paper we present a short outlook on how our method may be
extended to cover other classes of Hamiltonians; details will be given
elsewhere.


title: Real- and redshift-space halo clustering in $f(R)$ cosmologies

abstract:
  We present two-point correlation function statistics of the mass and the
halos in the chameleon $f(R)$ modified gravity scenario using a series of large
volume N-body simulations. Three distinct variations of $f(R)$ are considered
(F4, F5 and F6) and compared to a fiducial $\Lambda$CDM model in the redshift
range $z \in [0,1]$. We find that the matter clustering is indistinguishable
for all models except for F4, which shows a significantly steeper slope. The
ratio of the redshift- to real-space correlation function at scales $> 20
h^{-1} \mathrm{Mpc}$ agrees with the linear General Relativity (GR) Kaiser
formula for the viable $f(R)$ models considered. We consider three halo
populations characterized by spatial abundances comparable to that of luminous
red galaxies (LRGs) and galaxy clusters. The redshift-space halo correlation
functions of F4 and F5 deviate significantly from $\Lambda$CDM at intermediate
and high redshift, as the $f(R)$ halo bias is smaller or equal to that of the
$\Lambda$CDM case. Finally we introduce a new model independent clustering
statistic to distinguish $f(R)$ from GR: the relative halo clustering ratio --
$\mathcal{R}$. The sampling required to adequately reduce the scatter in
$\mathcal{R}$ will be available with the advent of the next generation galaxy
redshift surveys. This will foster a prospective avenue to obtain largely
model-independent cosmological constraints on this class of modified gravity
models.


title: Sphere branched coverings and the growth rate inequality

abstract:
  We show that the growth inequality rate $$\limsup \frac{1}{n} \log (\# Fix
(f^n))\geq \log d$$ holds for branched coverings of degree $d$ of the sphere
$S^2$ having a completely invariant simply connected region $R$ with locally
connected boundary, except in some degenerate cases with known couterexamples.


title:
Methods and Tools for Bayesian Variable Selection and Model Averaging in
  Univariate Linear Regression

abstract:
  In this paper we briefly review the main methodological aspects concerned
with the application of the Bayesian approach to model choice and model
averaging in the context of variable selection in regression models. This
includes prior elicitation, summaries of the posterior distribution and
computational strategies. We then examine and compare various publicly
available {\tt R}-packages for its practical implementation summarizing and
explaining the differences between packages and giving recommendations for
applied users. We find that all packages reviewed lead to very similar results,
but there are potentially important differences in flexibility and efficiency
of the packages.


title:
A-optimal encoding weights for nonlinear inverse problems, with
  applications to the Helmholtz inverse problem

abstract:
  The computational cost of solving an inverse problem governed by PDEs, using
multiple experiments, increases linearly with the number of experiments. A
recently proposed method to decrease this cost uses only a small number of
random linear combinations of all experiments for solving the inverse problem.
This approach applies to inverse problems where the PDE solution depends
linearly on the right-hand side function that models the experiment. As this
method is stochastic in essence, the quality of the obtained reconstructions
can vary, in particular when only a small number of combinations are used. We
develop a Bayesian formulation for the definition and computation of encoding
weights that lead to a parameter reconstruction with the least uncertainty. We
call these weights A-optimal encoding weights. Our framework applies to inverse
problems where the governing PDE is nonlinear with respect to the inversion
parameter field. We formulate the problem in infinite dimensions and follow the
optimize-then-discretize approach, devoting special attention to the
discretization and the choice of numerical methods in order to achieve a
computational cost that is independent of the parameter discretization. We
elaborate our method for a Helmholtz inverse problem, and derive the
adjoint-based expressions for the gradient of the objective function of the
optimization problem for finding the A-optimal encoding weights. The proposed
method is potentially attractive for real-time monitoring applications, where
one can invest the effort to compute optimal weights offline, to later solve an
inverse problem repeatedly, over time, at a fraction of the initial cost.


title:
Dielectric properties of graphene on transition metal dichalcogenide
  substrate

abstract:
  The tunability of the dielectric properties induced by the substrate driven
interactions (SDI) and the exchange field (M) due to the ferro-magnetic
impurities in graphene monolayer on transition metal dichalcogenide (TMDC)
(viz., XY2 , X = Mo, W; Y = S, Se) around K and K prime points is reported
here. The cavalcade of interactions involve sub-lattice-resolved, strongly
enhanced intrinsic spin-orbit couplings(SOC), the extrinsic Rashba spin-orbit
coupling (RSOC), and the orbital gap related to the transfer of the electronic
charge from graphene to XY2. The RSOC allows for external tuning of the band
gap in graphene and connects the nearest neighbors with spin-flip. We obtain
the usual gapped bands with an effective, RSOC-dependent Zeeman field due to
the interplay of SDI. Using these bands we obtain the closed analytical
expression of the dielectric function in the finite doping case. The zero of
the dielectric function corresponds to the collective mode. Upon including the
full dispersion of graphene on TMDC, we find that there is in fact only one
collective mode and it corresponds to charge plasmons. The dispersion of the
latter yields the q^2/3 behavior and not the well known q^1/2 behavior. We also
find that the plasmon frequency could be changed by the tuning of the chemical
potential.


title: Gilbert damping of magnetostatic modes in a yttrium iron garnet sphere

abstract:
  The magnetostatic mode (MSM) spectrum of a 300$\mu$m diameter single
crystalline sphere of yttrium iron garnet is investigated using broadband
ferromagnetic resonance (FMR). The individual MSMs are identified via their
characteristic dispersion relations and the corresponding mode number tuples
$(nmr)$ are assigned. Taking FMR data over a broad frequency and magnetic field
range allows to analyze both the Gilbert damping parameter~$\alpha$ and the
inhomogeneous line broadening contribution to the total linewidth of the MSMs
separately. The linewidth analysis shows that all MSMs share the same Gilbert
damping parameter $\alpha=2.7(5) \times 10^{-5}$ irrespective of their mode
index. In contrast, the inhomogeneous line broadening shows a pronounced mode
dependence. This observation is modeled in terms of two-magnon scattering
processes of the MSMs into the spin-wave manifold, mediated by surface and
volume defects.


title: Bounds of Zagreb indices and hyper Zagreb indices

abstract:
  The hyper Zagreb index is a kind of extensions of Zagreb index, used for
predicting physicochemical properties of organic compounds. Given a graph $G=
(V(G), E(G))$, the first hyper-Zagreb index is the sum of the square of edge
degree over edge set $E(G)$ and defined as $HM_1(G)=\sum_{e=uv\in E(G)}d(e)^2$,
where $d(e)=d(u)+d(v)$ is the edge degree. In this work we define the second
hyper-Zagreb index on the adjacent edges as $HM_2(G)=\sum_{e\sim f}d(e)d(f)$,
where $e\sim f$ represents the adjacent edges of $G$. By inequalities, we
explore some upper and lower bounds of these hyper-Zagreb indices, and provide
the relation between Zagreb indices and hyper Zagreb indices.


title:
Designing Perturbative Metamaterials from Discrete Models: From Veselago
  lenses to topological insulators

abstract:
  Discrete models provide concise descriptions of complex physical phenomena,
such as negative refraction, topological insulators, and Anderson localization.
While there are multiple tools to obtain discrete models that demonstrate
particular phenomena, it remains a challenge to find metamaterial designs that
replicate the behavior of desired nontrivial discrete models. Here we solve
this problem by introducing a new class of metamaterial, which we term
'perturbative metamaterial', consisting of weakly interacting unit cells. The
weak interaction allows us to associate each element of the discrete model
(individual masses and springs) to individual geometric features of the
metamaterial, thereby enabling a systematic design process. We demonstrate our
approach by designing 2D mechanical metamaterials that realize Veselago lenses,
zero-dispersion bands, and topological insulators. While our selected examples
are within the mechanical domain, the same design principle can be applied to
acoustic, thermal, and photonic metamaterials composed of weakly interacting
unit cells.


title: More ${\mathcal N}=4$ superconformal bootstrap

abstract:
  In this long overdue second installment, we continue to develop the conformal
bootstrap program for ${\mathcal N}=4$ superconformal field theories in four
dimensions via an analysis of the correlation function of four stress-tensor
supermultiplets. We review analytic results for this correlator and make
contact with the SCFT/chiral algebra correspondence of arXiv:1312.5344. We
demonstrate that the constraints of unitarity and crossing symmetry require the
central charge $c$ to be greater than or equal to $3/4$ in any interacting
${\mathcal N}=4$ SCFT. We apply numerical bootstrap methods to derive upper
bounds on scaling dimensions and OPE coefficients for several low-lying,
unprotected operators as a function of the central charge. We interpret our
bounds in the context of ${\mathcal N}=4$ super Yang-Mills (SYM) theories,
formulating a series of conjectures regarding the embedding of the conformal
manifold --- parametrized by the complexified gauge coupling --- into the space
of scaling dimensions and OPE coefficients. Our conjectures assign a
distinguished role to points on the conformal manifold that are self-dual under
a subgroup of the S-duality group. This paper contains a more detailed
exposition of a number of results previously reported in arXiv:1304.1803 in
addition to new results.


title:
Slope and curvature of the hadron vacuum polarization at vanishing
  virtuality from lattice QCD

abstract:
  We compute the slope and curvature, at vanishing four-momentum transfer
squared, of the leading order hadron vacuum polarization function, using
lattice QCD. Calculations are performed with 2+1+1 flavors of staggered
fermions directly at the physical values of the quark masses and in volumes of
linear extent larger than 6fm. The continuum limit is carried out using six
different lattice spacings. All connected and disconnected contributions are
calculated, up to and including those of the charm.


title:
Quantum phases of interacting three-component fermions under the
  influence of spin-orbit coupling and Zeeman fields

abstract:
  We describe the quantum phases of interacting three component fermions in the
presence of spin-orbit coupling, as well as linear and quadratic Zeeman fields.
We classify the emerging superfluid phases in terms of the loci of zeros of
their quasi-particle excitation spectrum in momentum space, and we identify
several Lifshitz-type topological transitions. In the particular case of
vanishing quadratic Zeeman field, a quintuple point exists where four gapless
superfluid phases with surface and line nodes converge into a fully gapped
superfluid phase. Lastly, we also show that the simultaneous presence of
spin-orbit and Zeeman fields transforms a momentum-independent scalar order
parameter into an explicitly momentum-dependent tensor in the generalized
helicity basis.


title: Galaxy kinematics in the XMMU J2235-2557 cluster field at z~1.4

abstract:
  We took spatially resolved slit FORS2 spectra of 19 cluster galaxies at
z=1.4, and 8 additional field galaxies at 1<z<1.2 using the ESO Very Large
Telescope. The targets were selected from previous spectroscopic and
photometric campaigns. Our spectroscopy was complemented with HST-ACS imaging
in the F775W and F850LP filters, which is mandatory to derive the galaxy
structural parameters accurately. We analyzed the ionized gas kinematics by
extracting rotation curves from the two-dimensional spectra. Taking into
account all geometrical, observational, and instrumental effects, we used these
rotation curves to derive the intrinsic maximum rotation velocity (Vmax). Vmax
was robustly determined for 6 cluster galaxies and 3 field galaxies. Galaxies
with sky contamination or insufficient spatial rotation curve extent were not
included in our analysis. We compared our sample to the local B-band
Tully-Fisher relation (TFR) and the local Velocity-Size relation (VSR), finding
that cluster galaxies are on average 1.6 mags brighter and a factor 2-3
smaller. We tentatively divided our cluster galaxies by total mass (i.e., Vmax)
to investigate a possible mass dependency in the environmental evolution of
galaxies. The average deviation from the local B-band TFR is -0.7 mags for the
high-mass subsample. This mild evolution may be driven by younger stellar
populations of distant galaxies with respect to their local counterparts, and
thus, an increasing luminosity is expected towards higher redshifts. However,
the low-mass group is made of 3 highly overluminous galaxies with average TFR
offsets of -2.4 mags. This deviation can no longer be explained by the gradual
evolution of SP with lookback time and thus, we suspect that we see rather
compact galaxies that got an enhancement of star formation during their infall
towards the dense regions of the cluster due to interactions with the
intracluster medium.


title:
Subcritical multiplicative chaos for regularized counting statistics
  from random matrix theory

abstract:
  For an $N \times N$ random unitary matrix $U_N$, we consider the random field
defined by counting the number of eigenvalues of $U_N$ in a mesoscopic arc of
the unit circle, regularized at an $N$-dependent scale $\epsilon_N>0$. We prove
that the renormalized exponential of this field converges as $N \to \infty$ to
a Gaussian multiplicative chaos measure in the whole subcritical phase. In
addition, we show that the moments of the total mass converge to a Selberg-like
integral and by taking a further limit as the size of the arc diverges, we
establish part of the conjectures in \cite{Ost16}. By an analogous
construction, we prove that the multiplicative chaos measure coming from the
sine process has the same distribution, which strongly suggests that this
limiting object should be universal. The proofs are based on the asymptotic
analysis of certain Toeplitz or Fredholm determinants using the
Borodin-Okounkov formula or a Riemann-Hilbert problem for integrable operators.
Our approach to the $L^{1}$-phase is based on a generalization of the
construction in Berestycki \cite{Berestycki15} to random fields which are only
\textit{asymptotically} Gaussian. In particular, our method could have
applications to other random fields coming from either random matrix theory or
a different context.


title: Approximate quadrature measures on data--defined spaces

abstract:
  An important question in the theory of approximate integration is to study
the conditions on the nodes $x_{k,n}$ and weights $w_{k,n}$ that allow an
estimate of the form $$ \sup_{f\in \mathcal{B}_\gamma}|\sum_k
w_{k,n}f(x_{k,n})-\int_\mathbb{X} fd\mu^*| \le cn^{-\gamma}, \qquad
n=1,2,\cdots, $$ where $\mathbb{X}$ is often a manifold with its volume measure
$\mu^*$, and $\mathcal{B}_\gamma$ is the unit ball of a suitably defined
smoothness class, parametrized by $\gamma$. In this paper, we study this
question in the context of a quasi-metric, locally compact, measure space
$\mathbb{X}$ with a probability measure $\mu^*$. We show that quadrature
formulas exact for integrating the so called diffusion polynomials of degree
$<n$ satisfy such estimates. Without requiring exactness, such formulas can be
obtained as a solutions of some kernel-based optimization problem. We discuss
the connection with the question of optimal covering radius. Our results
generalize in some sense many recent results in this direction.


title: Virtual Element Method for the Laplace-Beltrami equation on surfaces

abstract:
  We present and analyze a Virtual Element Method (VEM) of arbitrary polynomial
order $k\in\mathbb{N}$ for the Laplace-Beltrami equation on a surface in
$\mathbb{R}^3$. The method combines the Surface Finite Element Method (SFEM)
[Dziuk, Elliott, \emph{Finite element methods for surface PDEs}, 2013] and the
recent VEM [Beirao da Veiga et al, \emph{Basic principles of Virtual Element
Methods}, 2013] in order to handle arbitrary polygonal and/or nonconforming
meshes. We account for the error arising from the geometry approximation and
extend to surfaces the error estimates for the interpolation and projection in
the virtual element function space. In the case $k=1$ of linear Virtual
Elements, we prove an optimal $H^1$ error estimate for the numerical method.
The presented method has the capability of handling the typically nonconforming
meshes that arise when two ore more meshes are pasted along a straight line.
Numerical experiments are provided to confirm the convergence result and to
show an application of mesh pasting.


title: Supersymmetry Across the Light and Heavy-Light Hadronic Spectrum II

abstract:
  We extend our analysis of the implications of hadronic supersymmetry for
heavy-light hadrons in light-front holographic QCD. Although conformal symmetry
is strongly broken by the heavy quark mass, supersymmetry and the holographic
embedding of semiclassical light-front dynamics derived from five-dimensional
anti-de Sitter (AdS) space nevertheless determines the form of the confining
potential in the light-front Hamiltonian to be harmonic. The resulting
light-front bound-state equations lead to a heavy-light Regge-like spectrum for
both mesons and baryons. The confinement hadron mass scale and their Regge
slopes depend, however, on the mass of the heavy quark in the meson or baryon
as expected from Heavy Quark Effective Theory (HQET). This procedure reproduces
the observed spectra of heavy-light hadrons with good precision and makes
predictions for yet unobserved states.


title: Charm Production and QCD Analysis at HERA and LHC

abstract:
  This review is devoted to the study of charm production in ep and pp
collisions. The total set of measurements obtained by the two collaborations H1
and ZEUS from HERA and their combination is outlined, as well as complementary
data obtained by the LHCb collaboration at the LHC. After fitting the parton
distribution functions the charm production cross sections are predicted within
perturbative QCD at next-to-leading order using the fixed-flavour-number
scheme. Agreement with the data is found. The combined HERA charm data are
sensitive to the $c$-quark mass and enabled its accurate determination. The
predictions crucially depend upon the knowledge of the gluon distribution
function. It is shown that the shape of the gluon distribution based on the
HERA data is considerably improved by adding the measurements from LHCb and
applicable down to values x of about 10^{-6}, where x is the proton momentum
fraction carried by a parton.


title: Differential Angular Imaging for Material Recognition

abstract:
  Material recognition for real-world outdoor surfaces has become increasingly
important for computer vision to support its operation "in the wild."
Computational surface modeling that underlies material recognition has
transitioned from reflectance modeling using in-lab controlled radiometric
measurements to image-based representations based on internet-mined images of
materials captured in the scene. We propose to take a middle-ground approach
for material recognition that takes advantage of both rich radiometric cues and
flexible image capture. We realize this by developing a framework for
differential angular imaging, where small angular variations in image capture
provide an enhanced appearance representation and significant recognition
improvement. We build a large-scale material database, Ground Terrain in
Outdoor Scenes (GTOS) database, geared towards real use for autonomous agents.
The database consists of over 30,000 images covering 40 classes of outdoor
ground terrain under varying weather and lighting conditions. We develop a
novel approach for material recognition called a Differential Angular Imaging
Network (DAIN) to fully leverage this large dataset. With this novel network
architecture, we extract characteristics of materials encoded in the angular
and spatial gradients of their appearance. Our results show that DAIN achieves
recognition performance that surpasses single view or coarsely quantized
multiview images. These results demonstrate the effectiveness of differential
angular imaging as a means for flexible, in-place material recognition.


title: Relativistic Dynamics and Mass Exchange in Binary Black Hole Mini-Disks

abstract:
  We present the first exploration of relativistic gas dynamics in the
immediate vicinity of binary black holes as the system inspirals close to
merger in the gravitational radiation-driven regime. We focus on 2D
hydrodynamical studies of comparable-mass, non-spinning systems. Relativistic
effects alter the dynamics of gas in this environment in several ways. Because
the gravitational potential between the two black holes becomes shallower than
in the Newtonian regime, the mini-disks stretch toward the L1 point and the
amount of gas passing back and forth between the mini-disks increases sharply
with decreasing binary separation. This "sloshing" is quasi-periodically
modulated at $2$ and $2.75$ times the binary orbital frequency, corresponding
to timescales of hours to days for supermassive binary black holes. In
addition, relativistic effects add an $m=1$ component to the tidally-driven
spiral waves in the disks that are purely $m=2$ in Newtonian gravity; this
component becomes dominant when the separation is $\lesssim 100$ gravitational
radii. Both the sloshing and the spiral waves have the potential to create
distinctive radiation features that may uniquely mark supermassive binary black
holes in the relativistic regime.


title:
Automatic Detection of ADHD and ASD from Expressive Behaviour in RGBD
  Data

abstract:
  Attention Deficit Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder
(ASD) are neurodevelopmental conditions which impact on a significant number of
children and adults. Currently, the diagnosis of such disorders is done by
experts who employ standard questionnaires and look for certain behavioural
markers through manual observation. Such methods for their diagnosis are not
only subjective, difficult to repeat, and costly but also extremely time
consuming. In this work, we present a novel methodology to aid diagnostic
predictions about the presence/absence of ADHD and ASD by automatic visual
analysis of a person's behaviour. To do so, we conduct the questionnaires in a
computer-mediated way while recording participants with modern RGBD
(Colour+Depth) sensors. In contrast to previous automatic approaches which have
focussed only detecting certain behavioural markers, our approach provides a
fully automatic end-to-end system for directly predicting ADHD and ASD in
adults. Using state of the art facial expression analysis based on Dynamic Deep
Learning and 3D analysis of behaviour, we attain classification rates of 96%
for Controls vs Condition (ADHD/ASD) group and 94% for Comorbid (ADHD+ASD) vs
ASD only group. We show that our system is a potentially useful time saving
contribution to the diagnostic field of ADHD and ASD.


title:
Distribution of Cell Area in Bounded Poisson Voronoi Tessellations with
  Application to Secure Local Connectivity

abstract:
  Poisson Voronoi tessellations have been used in modeling many types of
systems across different sciences, from geography and astronomy to
telecommunications. The existing literature on the statistical properties of
Poisson Voronoi cells is vast, however, little is known about the properties of
Voronoi cells located close to the boundaries of a compact domain. In a domain
with boundaries, some Voronoi cells would be naturally clipped by the boundary,
and the cell area falling inside the deployment domain would have different
statistical properties as compared to those of non-clipped Voronoi cells
located in the bulk of the domain. In this paper, we consider the planar
Voronoi tessellation induced by a homogeneous Poisson point process of
intensity $\lambda\!>\!0$ in a quadrant, where the two half-axes represent
boundaries. We show that the mean cell area is less than $\lambda^{-1}$ when
the seed is located exactly at the boundary, and it can be larger than
$\lambda^{-1}$ when the seed lies close to the boundary. In addition, we
calculate the second moment of cell area at two locations for the seed: (i) at
the corner of a quadrant, and (ii) at the boundary of the half-plane. We
illustrate that the two-parameter Gamma distribution, with location-dependent
parameters calculated using the method of moments, can be of use in
approximating the distribution of cell area. As a potential application, we use
the Gamma approximations to study the degree distribution for secure
connectivity in wireless sensor networks deployed over a domain with
boundaries.


title: Muon g-2 in GMSB with Adjoint Messengers

abstract:
  We explored the sparticle mass spectrum in light of the muon g-2 anomaly and
the little hierarchy problem in a class of gauge mediated supersymmetry
breaking model. Here the messenger fields transform in the adjoint
representation of the Standard Model gauge symmetry. To avoid unacceptably
light right-handed slepton masses the standard model is supplemented by
additional U(1)_B-L gauge symmetry. Considering a non-zero U(1)_B-L D-term
leads to an additional contribution to the soft supersymmetry breaking mass
terms which makes the right-handed slepton masses compatible with the current
experimental bounds. We show that in the framework of Lambda_{3}<0 and mu < 0,
the muon g-2 anomaly and the observed 125 GeV Higgs boson mass a can be
simultaneously accommodated. The slepton masses in this case are predicted to
lie in the few hundred GeV range, which can be tested at LHC. Despite the heavy
colored spectrum the the little hierarchy problem in this model can be
ameliorated and electroweak fine tuning parameter can be as low as 10 or so.


title: A Method for Group Extraction and Analysis in Multilayer Social Networks

abstract:
  The main subject studied in this dissertation is a multi-layered social
network (MSN) and its analysis. One of the crucial problems in multi-layered
social network analysis is community extraction. To cope with this problem the
CLECC measure (Cross Layered Edge Clustering Coefficient) was proposed in the
thesis. It is an edge measure which expresses how much the neighbors of two
given users are similar each other. Based on this measure the CLECC algorithm
for community extraction in the multi-layered social networks was designed. The
algorithm was tested on the real single-layered social networks (SSN) and
multi-layered social networks (MSN), as well as on benchmark networks from GN
Benchmark (SSN), LFR Benchmark (SSN) and mLFR Benchmark (MSN) a special
extension of LFR Benchmark, designed as a part of this thesis, which is able to
produce multi-layered benchmark networks. The second research problem
considered in the thesis was group evolution discovery. Studies on this problem
have led to the development of the inclusion measure and the Group Evolution
Discovery (GED) method, which is designed to identify events between two groups
in successive time frames in the social network. The method was tested on a
real social network and compared with two well-known algorithms regarding
accuracy, execution time, flexibility and ease of implementation. Finally, a
new approach to prediction of group evolution in the social network was
developed. The new approach involves usage of the outputs of the GED method. It
is shown, that using even a simple sequence, which consists of several
preceding groups sizes and events, as an input for the classifier, the learned
model can produce very good results also for simple classifiers.


title: The arrow of time and the Bell inequalities

abstract:
  It is recalled that closed (isolated) systems are essentially reversible
whilst open systems like the Earth, or living beings on it, are irreversible
because they are not isolated. Earth and life irreversibility derives from the
evolution of the universe, which is a consequence of its special initial
conditions. It is stressed that, although relativity theory forbids that
information travels faster than light, it does not forbid influences of an
event on its past light cone. Therefore the violation of Bell inequalities in
loophole-free experiments is compatible with relativity theory. A correlation
formula, alternative to Bell's, is proposed as the starting point for hidden
variables models fitting in relativity.


title: Structural studies of silicate glasses with PbS and PbSe nanoparticles

abstract:
  Optical materials with semiconductor nanoparticles within dielectric matrices
are of interest for construction of non-linear optical elements, selective
filters, spectral converters, etc. In the present work, we concern the glasses
with PbS and PbSe fabricated by the two-step technique on the basis of silicate
glass matrix and report the recent studied using the small-angle neutron
scattering (SANS) technique. A proper understanding the structure of material,
size of particles and spectral features need to control optical functionality
of glasses. SANS is efficient non-destructive technique allowing a wide range
of structural models in the size range from atomic clusters to submicron size.
Here we combine SANS measurements with wide-angle X-ray diffraction (WXRD) and
electron microscopy to get information on nanoparticles formed in a series of
PbS and PbSe-doped silicate glasses.


title:
Thermodynamic formalism for transport coefficients with an application
  to the shear modulus and shear viscosity

abstract:
  We discuss Onsager's thermodynamic formalism for transport coefficients and
apply it to the calculation of the shear modulus and shear viscosity of a
monodisperse system of repulsive particles. We focus on the concept of
extensive "distance" and intensive "field" conjugated via a Fenchel-Legendre
transform involving a thermodynamic(-like) potential, which allows to switch
ensembles. Employing Brownian dynamics, we calculate both the shear modulus and
the shear viscosity from strain fluctuations and show that they agree with
direct calculations from strained and non-equilibrium simulations,
respectively. We find a dependence of the fluctuations on the coupling strength
to the strain reservoir, which can be traced back to the discrete-time
integration. These results demonstrate the viability of exploiting fluctuations
of extensive quantities for the numerical calculation of transport
coefficients.


title: Stability of Springer representations for type $A$

abstract:
  We prove certain stability properties of Springer representations for type
$A$.


title:
A Model-Based Approach to Wildland Fire Reconstruction Using Sediment
  Charcoal Records

abstract:
  Lake sediment charcoal records are used in paleoecological analyses to
reconstruct fire history including the identification of past wildland fires.
One challenge of applying sediment charcoal records to infer fire history is
the separation of charcoal associated with local fire occurrence and charcoal
originating from regional fire activity. Despite a variety of methods to
identify local fires from sediment charcoal records, an integrated statistical
framework for fire reconstruction is lacking. We develop a Bayesian point
process model to estimate probability of fire associated with charcoal counts
from individual-lake sediments and estimate mean fire return intervals. A
multivariate extension of the model combines records from multiple lakes to
reduce uncertainty in local fire identification and estimate a regional mean
fire return interval. The univariate and multivariate models are applied to 13
lakes in the Yukon Flats region of Alaska. Both models resulted in similar mean
fire return intervals (100-350 years) with reduced uncertainty under the
multivariate model due to improved estimation of regional charcoal deposition.
The point process model offers an integrated statistical framework for
paleo-fire reconstruction and extends existing methods to infer regional fire
history from multiple lake records with uncertainty following directly from
posterior distributions.


title:
An Exact Redatuming Procedure for the Inverse Boundary Value Problem for
  the Wave Equation

abstract:
  Redatuming is a data processing technique to transform measurements recorded
in one acquisition geometry to an analogous data set corresponding to another
acquisition geometry, for which there are no recorded measurements. We consider
a redatuming problem for a wave equation on a bounded domain, or on a manifold
with boundary, and model data acquisition by a restriction of the associated
Neumann-to-Dirichlet map. This map models measurements with sources and
receivers on an open subset $\Gamma$ contained in the boundary of the manifold.
We model the wavespeed by a Riemannian metric, and suppose that the metric is
known in some coordinates in a neighborhood of $\Gamma$. Our goal is to move
sources and receivers into this known near boundary region. We formulate
redatuming as a collection of unique continuation problems, and provide a two
step procedure to solve the redatuming problem. We investigate the stability of
the first step in this procedure, showing that it enjoys conditional H\"{o}lder
stability under suitable geometric hypotheses. In addition, we provide
computational experiments that demonstrate our redatuming procedure.


title: Subquadratic Algorithms for Algebraic Generalizations of 3SUM

abstract:
  The 3SUM problem asks if an input $n$-set of real numbers contains a triple
whose sum is zero. We consider the 3POL problem, a natural generalization of
3SUM where we replace the sum function by a constant-degree polynomial in three
variables. The motivations are threefold. Raz, Sharir, and de Zeeuw gave a
$O(n^{11/6})$ upper bound on the number of solutions of trivariate polynomial
equations when the solutions are taken from the cartesian product of three
$n$-sets of real numbers. We give algorithms for the corresponding problem of
counting such solutions. Gr\o nlund and Pettie recently designed subquadratic
algorithms for 3SUM. We generalize their results to 3POL. Finally, we shed
light on the General Position Testing (GPT) problem: "Given $n$ points in the
plane, do three of them lie on a line?", a key problem in computational
geometry.
  We prove that there exist bounded-degree algebraic decision trees of depth
$O(n^{\frac{12}{7}+\varepsilon})$ that solve 3POL, and that 3POL can be solved
in $O(n^2 {(\log \log n)}^\frac{3}{2} / {(\log n)}^\frac{1}{2})$ time in the
real-RAM model. Among the possible applications of those results, we show how
to solve GPT in subquadratic time when the input points lie on $o({(\log
n)}^\frac{1}{6}/{(\log \log n)}^\frac{1}{2})$ constant-degree polynomial
curves. This constitutes a first step towards closing the major open question
of whether GPT can be solved in subquadratic time.
  To obtain these results, we generalize important tools --- such as batch
range searching and dominance reporting --- to a polynomial setting. We expect
these new tools to be useful in other applications.


title: Decoupling inequalities for the Ginzburg-Landau $\nabla \varphi$ models

abstract:
  We consider a class of of massless gradient Gibbs measures, in dimension
greater or equal to three, and prove a decoupling inequality for these fields.
As a result, we obtain detailed information about their geometry, and the
percolative and non-percolative phases of their level sets, thus generalizing
results obtained in arXiv:1202.5172, to the non-Gaussian case. Inequalities of
similar flavor have also been successfully used in the study of random
interlacements, see arXiv:1010.1490, arXiv:1212.1605. A crucial aspect is the
development of a suitable sprinkling technique, which relies on a particular
representation of the correlations in terms of a random walk in a dynamic
random environment, due to Helffer and Sj\"{o}strand. The sprinkling can be
effectively implemented by studying the Dirichlet problem for the corresponding
Poisson equation, and quantifiying in how far a change in boundary condition
along a sufficiently "small" part of the boundary affects the solution. Our
results allow for uniformly convex potentials, and extend to non-convex
perturbations thereof.


title:
Complexity Reduction in Large Quantum Systems: Fragment Identification
  and Population Analysis via a Local Optimized Minimal Basis

abstract:
  We present, within Kohn-Sham Density Functional Theory calculations, a
quantitative method to identify and assess the partitioning of a large quantum
mechanical system into fragments. We then show how within this framework simple
generalizations of other well-known population analyses can be used to extract,
from first principles, reliable electrostatic multipoles for the identified
fragments. Our approach reduces arbitrariness in the fragmentation procedure,
and enables the possibility to assess, quantitatively, whether the
corresponding fragment multipoles can be interpreted as observable quantities
associated to a system's moiety. By applying our formalism within the code
BigDFT, we show that the use of a minimal set of in-situ optimized basis
functions allows at the same time a proper fragment definition and an accurate
description of the electronic structure.


title: Unblinding the Dark Matter Blind Spots

abstract:
  The dark matter (DM) blind spots in the Minimal Supersymmetric Standard Model
(MSSM) refer to the parameter regions where the couplings of the DM particles
to the $Z$-boson or the Higgs boson are almost zero, leading to vanishingly
small signals for the DM direct detections. In this paper, we carry out
comprehensive analyses for the DM searches under the blind-spot scenarios in
MSSM. Guided by the requirement of acceptable DM relic abundance, we explore
the complementary coverage for the theory parameters at the LHC, the projection
for the future underground DM direct searches, and the indirect searches from
the relic DM annihilation into photons and neutrinos. We find that (i) the
spin-independent (SI) blind spots may be rescued by the spin-dependent (SD)
direct detection in the future underground experiments, and possibly by the
indirect DM detections from IceCube and SuperK neutrino experiments; (ii) the
detection of gamma rays from Fermi-LAT may not reach the desirable sensitivity
for searching for the DM blind-spot regions; (iii) the SUSY searches at the LHC
will substantially extend the discovery region for the blind-spot parameters.
The dark matter blind spots thus may be unblinded with the collective efforts
in future DM searches.


title:
Concentrating solutions for a class of nonlinear fractional
  Schr\"odinger equations in $\mathbb{R}^{N}$

abstract:
  We deal with the existence of positive solutions for the following fractional
Schr\"odinger equation $$ \varepsilon ^{2s} (-\Delta)^{s} u + V(x) u = f(u)
\mbox{ in } \mathbb{R}^{N}, $$ where $\varepsilon>0$ is a parameter, $s\in (0,
1)$, $N>2s$, $(-\Delta)^{s}$ is the fractional Laplacian operator, and
$V:\mathbb{R}^{N}\rightarrow \mathbb{R}$ is a continuous positive function.
Under the assumptions that the nonlinearity $f$ is either asymptotically linear
or superlinear at infinity, we prove the existence of a family of positive
solutions which concentrates at a local minimum of $V$ as $\varepsilon$ tends
to zero.


title: Marginal relevance for the $\gamma$-stable pinning model

abstract:
  We investigate disorder relevance for the pinning of a renewal when the law
of the random environment is in the domain of attraction of a stable law with
parameter $\gamma \in (1,2)$. Assuming that the renewal jumps have power-law
decay, we determine under which condition the critical point of the system
modified by the introduction of a small quantity of disorder. In an earlier
study of the problem, we have shown that the answer depends on the value of the
tail exponent $\alpha$ associated to the distribution of renewal jumps: when
$\alpha>1-\gamma^{-1}$ a small amount of disorder shifts the critical point
whereas it does not when $\alpha<1-\gamma^{-1}$. The present paper is focused
on the boundary case $\alpha=1-\gamma^{-1}$. We show that a critical point
shifts occurs in this case, and obtain an estimate for its intensity.


title: Quantum parameter estimation with the Landau-Zener transition

abstract:
  We investigate the fundamental limits in precision allowed by quantum
mechanics from Landau-Zener transitions, concerning Hamiltonian parameters.
While the Landau-Zener transition probabilities depend sensitively on the
system parameters, much more precision may be obtained using the acquired
phase, quantified by the quantum Fisher information. This information scales
with a power of the elapsed time for the quantum case, whereas it is
time-independent if the transition probabilities alone are used. We add
coherent control to the system, and increase the permitted maximum precision in
this time-dependent quantum system. The case of multiple passes before
measurement, "Landau-Zener-Stueckelberg interferometry", is considered, and we
demonstrate that proper quantum control can cause the quantum Fisher
information about the oscillation frequency to scale as $T^4$, where $T$ is the
elapsed time.


title: Semi-Supervised linear regression

abstract:
  We study a regression problem where for some part of the data we observe both
the label variable ($Y$) and the predictors (${\bf X}$), while for other part
of the data only the predictors are given. Such a problem arises, for example,
when observations of the label variable are costly and may require a skilled
human agent. When the conditional expectation $E[Y | {\bf X}]$ is not exactly
linear, one can consider the best linear approximation to the conditional
expectation, which can be estimated consistently by the least squares estimates
(LSE). The latter depends only on the labeled data. We suggest improved
alternative estimates to the LSE that use also the unlabeled data. Our
estimation method can be easily implemented and has simply described asymptotic
properties.The new estimates asymptotically dominate the usual standard
procedures under certain non-linearity condition of $E[Y | {\bf X}]$;
otherwise, they are asymptotically equivalent.The performance of the new
estimator for small sample size is investigated in an extensive simulation
study. A real data example of inferring homeless population is used to
illustrate the new methodology.


title:
The Kepler Follow-Up Observation Program. I. A Catalog of Companions to
  Kepler Stars from High-Resolution Imaging

abstract:
  We present results from high-resolution, optical to near-IR imaging of host
stars of Kepler Objects of Interest (KOIs), identified in the original Kepler
field. Part of the data were obtained under the Kepler imaging follow-up
observation program over seven years (2009 - 2015). Almost 90% of stars that
are hosts to planet candidates or confirmed planets were observed. We combine
measurements of companions to KOI host stars from different bands to create a
comprehensive catalog of projected separations, position angles, and magnitude
differences for all detected companion stars (some of which may not be bound).
Our compilation includes 2297 companions around 1903 primary stars. From
high-resolution imaging, we find that ~10% (~30%) of the observed stars have at
least one companion detected within 1" (4"). The true fraction of systems with
close (< ~4") companions is larger than the observed one due to the limited
sensitivities of the imaging data. We derive correction factors for planet
radii caused by the dilution of the transit depth: assuming that planets orbit
the primary stars or the brightest companion stars, the average correction
factors are 1.06 and 3.09, respectively. The true effect of transit dilution
lies in between these two cases and varies with each system. Applying these
factors to planet radii decreases the number of KOI planets with radii smaller
than 2 R_Earth by ~2-23% and thus affects planet occurrence rates. This effect
will also be important for the yield of small planets from future transit
missions such as TESS.


title:
Examples of computation of exact moment dynamics for chemical reaction
  networks

abstract:
  We review in a unified way results for two types of stochastic chemical
reaction systems for which moments can be effectively computed: feedforward
networks and complex-balanced networks.


title:
Discerning the $\gamma$-ray emitting region in the flat spectrum radio
  quasars

abstract:
  A model-dependent method is proposed to determine the location of the
$\gamma$-ray emitting region for a given flat spectrum radio quasar (FSRQ). In
the model, the extra-relativistic electrons are injected at the base of the jet
and non-thermal photons are produced by both synchrotron radiation and
inverse-Comtpon (IC) scattering in the energy dissipation region. The target
photons dominating inverse-Comtpon scattering originate from both synchrotron
photons and external ambient photon fields, and the energy density of external
radiation field is a function of the distance between the position of
dissipation region and a central super-massive black hole, and their spectra
are seen in the comoving frame. Moreover, the energy dissipation region could
be determined by the model parameter through reproducing the $\gamma$-ray
spectra. Such a model is applied to reproduce the quasi-simultaneous
multi-wavelength observed data for 36 FSRQs. In order to define the width of
the broad-line region shell and dusty molecular torus shell, a simple numerical
constraint is used to determine the outer boundary of the broad-line region and
dusty molecular torus. Our results show that 1) the $\gamma$-ray emitting
regions are located at the range from 0.1 pc to 10 pc; 2) the $\gamma$-ray
emitting regions are located outside the broad-line regions and within the
dusty molecular tori; and 3) the $\gamma$-ray emitting region are located
closer to the dusty molecular torus ranges than the broad-line regions.
Therefore, it may concluded that a direct evidence for the \emph{far site}
scenario could be obtained on the basis of the model results.


title:
Updates to the Fermi-GBM Short GRB Targeted Offline Search in
  Preparation for LIGO's Second Observing Run

abstract:
  We detail the improvements made to the targeted offline search of Fermi-GBM
data for coincident signals to LIGO gravitational wave triggers. Description of
the changes are included, as well as comparisons between the ranking statistics
and False Alarm Rate distributions for the search during LIGO O1 and O2.


title:
Effects of uniaxial pressure on the quantum tunneling of magnetization
  in a high-symmetry Mn12 single-molecule magnet

abstract:
  The symmetry of single-molecule magnets dictates their spin quantum dynamics,
influencing how such systems relax via quantum tunneling of magnetization
(QTM). By reducing a system's symmetry, through the application of a magnetic
field or uniaxial pressure, these dynamics can be modified. We report
measurements of the magnetization dynamics of a crystalline sample of the
high-symmetry [Mn12O12(O2CMe)16(MeOH)4]MeOH single-molecule magnet as a
function of uniaxial pressure applied either parallel or perpendicular to the
sample's "easy" magnetization axis. At temperatures between 1.8 and 3.3 K,
magnetic hysteresis loops exhibit the characteristic steplike features that
signal the occurrence of QTM. After applying uniaxial pressure to the sample in
situ, both the magnitude and field position of the QTM steps changed. The step
magnitudes were observed to grow as a function of pressure in both arrangements
of pressure, while pressure applied along (perpendicular to) the sample's easy
axis caused the resonant-tunneling fields to increase (decrease). These
observations were compared with simulations in which the system's Hamiltonian
parameters were changed. From these comparisons, we determined that parallel
pressure induces changes to the second-order axial anisotropy parameter as well
as either the fourth-order axial or fourth-order transverse parameter, or to
both. In addition, we find that pressure applied perpendicular to the easy axis
induces a rhombic anisotropy E ~ D/2000 per kbar that can be understood as
deriving from a symmetry-breaking distortion of the molecule.


title:
Anisotropic interpolation error estimate for arbitrary quadrilateral
  isoparametric elements

abstract:
  The aim of this paper is to show that, for any $p \in [1,\infty)$, the
$W^{1,p}$-anisotropic interpolation error estimate holds on quadrilateral
isoparametric elements verifying the maximum angle condition ($MAC$) and the
property of comparable lengths for opposite sides ($clos$), i.e., on all those
quadrilaterals with interior angles uniformly bounded away from $\pi$ and with
both pairs of opposite sides having comparable lengths.
  For rectangular elements our interpolation error estimate agrees with the
usual one whereas for perturbations of rectangles (the most general
quadrilateral elements previously considered as far as we know) our result has
some advantages with respect to the pre-existing ones: the interpolation error
estimate that we proved is written by using two neighboring sides of the
element instead of the sides of the unknown perturbed rectangle and, on the
other hand, conditions $MAC$ and $clos$ are much simpler requirements to verify
and with a clearer geometrical sense than those involved in the definition of
perturbations of a rectangle.


title: The Interaction of Successive Coronal Mass Ejections: A Review

abstract:
  We present a review of the different aspects associated with the interaction
of successive CMEs in the corona and inner heliosphere, focusing on the
initiation of series of CMEs, their interaction in the heliosphere, the
particle acceleration associated with successive CMEs, and the effect of
compound events on Earth's magnetosphere. The two main mechanisms resulting in
the eruption of series of CMEs are sympathetic eruptions and homologous
eruptions. The interaction of successive CMEs has been observed remotely in
coronagraphs and heliospheric imagers, and inferred from in situ measurements.
It is associated with magnetic reconnection, momentum exchange, the propagation
of a fast magnetosonic shock through a magnetic ejecta and changes in CME
expansion. The presence of a CME a few hours before a fast eruption is
connected with higher fluxes of SEPs, while CME-CME interaction occurring in
the corona is often associated with unusual radio bursts. Higher suprathermal
population, enhanced turbulence and wave activity, stronger shocks, and
shock-shock or shock-CME interaction have been proposed as physical mechanisms
to explain these SEP events. When measured in situ, CME-CME interaction may be
associated with relatively well organized multiple-magnetic cloud events,
instances of shocks propagating through a previous magnetic ejecta or more
complex ejecta. The compression of a CME by another and the propagation of a
shock inside a magnetic ejecta can lead to extreme values of the southward
magnetic field, sometimes associated with large values of the dynamic pressure.
This can result in intense geomagnetic storms, but also trigger substorms and
large earthward motions of the magnetopause, potentially associated with
changes in the outer radiation belts. Future measurements by Solar Probe+ and
Solar Orbiter may shed light on the evolution of CMEs as they interact.


title: Black holes with halos

abstract:
  We present new AdS4 black hole solutions in N = 2 gauged supergravity coupled
to vector and hypermultiplets. We focus on a particular consistent truncation
of M-theory on the homogeneous Sasaki-Einstein seven-manifold M111,
characterized by the presence of one Betti vector multiplet. We numerically
construct static and spherically symmetric black holes with electric and
magnetic charges, corresponding to M2 and M5 branes wrapping non-contractible
cycles of the internal manifold. These configurations have nonzero temperature
and are moreover surrounded by a massive vector field halo. For these solutions
we verify the first law of black hole mechanics and we analyze the
thermodynamics and phase transitions in the canonical ensemble, interpreting
the process in the corresponding dual field theory.


title:
Multiple solutions for a class of nonhomogeneous fractional
  Schr\"odinger equations in $\mathbb{R}^{N}$

abstract:
  This paper is concerned with the following fractional Schr\"odinger equation
\begin{equation*} \left\{ \begin{array}{ll} (-\Delta)^{s} u+u= k(x)f(u)+h(x)
\mbox{ in } \mathbb{R}^{N}\\ u\in H^{s}(\R^{N}), \, u>0 \mbox{ in }
\mathbb{R}^{N}, \end{array} \right. \end{equation*} where $s\in (0,1)$, $N>
2s$, $(-\Delta)^{s}$ is the fractional Laplacian, $k$ is a bounded positive
function, $h\in L^{2}(\mathbb{R}^{N})$, $h\not \equiv 0$ is nonnegative and $f$
is either asymptotically linear or superlinear at infinity.\\ By using the
$s$-harmonic extension technique and suitable variational methods, we prove the
existence of at least two positive solutions for the problem under
consideration, provided that $|h|_{2}$ is sufficiently small.


title: DeMoN: Depth and Motion Network for Learning Monocular Stereo

abstract:
  In this paper we formulate structure from motion as a learning problem. We
train a convolutional network end-to-end to compute depth and camera motion
from successive, unconstrained image pairs. The architecture is composed of
multiple stacked encoder-decoder networks, the core part being an iterative
network that is able to improve its own predictions. The network estimates not
only depth and motion, but additionally surface normals, optical flow between
the images and confidence of the matching. A crucial component of the approach
is a training loss based on spatial relative differences. Compared to
traditional two-frame structure from motion methods, results are more accurate
and more robust. In contrast to the popular depth-from-single-image networks,
DeMoN learns the concept of matching and, thus, better generalizes to
structures not seen during training.


title:
Descendant log Gromov-Witten invariants for toric varieties and tropical
  curves

abstract:
  Using degeneration techniques, we prove the correspondence of tropical curve
counts and log Gromov-Witten invariants with general incidence and psi-class
conditions in toric varieties for genus zero curves and all non-superabundant
higher-genus situations. We also relate the log invariants to the ordinary
ones, in particular explaining the appearance of negative multiplicities in the
descendant correspondence result of Mark Gross.


title: Identification of Jet-like events using a Multiplicity Detector

abstract:
  We present a method for studying the detection of jets in high energy
hadronic collisions using multiplicity detector in forward rapidities. Such a
study enhances the physics scope of multiplicity detectors at forward
rapidities in LHC. At LHC energies the jets may be produced with significant
cross section in forward rapidities. A multi resolution wavelet analysis
technique can locate the spatial position of jets due to its feature of
space-scale locality. The discrete wavelet proves to be very effective in
probing physics simultaneously at different locations in phase space and at
different scales to identify jet-like events. The key feature this analysis
exploits is the difference in particle density in localized regions of the
detector due to jet-like and underlying events. We find that this method has a
significant sensitivity towards detecting jet position and its size. The jets
can be found with the efficiency and purity of the order of 46%.


title: AF algebras in the quantum Gromov-Hausdorff propinquity space

abstract:
  For unital AF algebras with faithful tracial states, we provide criteria for
convergence in the quantum Gromov-Hausdorff propinquity. For any unital AF
algebra, we introduce new Leibniz Lip-norms using quotient norms. Next, we show
that any unital AF algebra is the limit of its defining inductive sequence of
finite dimensional C*-algebras in quantum propinquity given any Lip-norm
defined on the inductive sequence. We also establish sufficient conditions for
when a *-isomorphism between two AF algebras produces a quantum isometry in the
context of various Lip-norms.


title:
An iterative algorithm for joint covariate and random effect selection
  in mixed effects models

abstract:
  We consider joint selection of fixed and random effects in general
mixed-effects models. The interpretation of estimated mixed-effects models is
challenging since changing the structure of one set of effects can lead to
different choices of important covariates in the model. We propose a stepwise
selection algorithm to perform simultaneous selection of the fixed and random
effects. It is based on BIC-type criteria whose penalties are adapted to
mixed-effects models. The proposed procedure performs model selection in both
linear and nonlinear models. It should be used in the low-dimension setting
where the number of covariates and the number of random effects are moderate
with respect to the total number of observations. The performance of the
algorithm is assessed via a simulation study, that includes also a comparative
study with alternatives when available in the literature. The use of the method
is illustrated in the clinical study of an antibiotic agent kinetics.


title: The qc Yamabe problem on non-spherical quaternionic contact manifolds

abstract:
  It is shown that the qc Yamabe problem has a solution on any compact qc
manifold which is non-locally qc equivalent to the standard 3-Sasakian sphere.
Namely, it is proved that on a compact non-locally spherical qc manifold there
exists a qc conformal qc structure with constant qc scalar curvature


title:
Comparison of weak and strong moments for vectors with independent
  coordinates

abstract:
  We show that for $p\ge 1$, the $p$-th moment of suprema of linear
combinations of independent centered random variables are comparable with the
sum of the first moment and the weak $p$-th moment provided that $2q$-th and
$q$-th integral moments of these variables are comparable for all $ q \ge 2$.
The latest condition turns out to be necessary in the i.i.d. case.


title:
Study of chiral vortical and magnetic effects in the anomalous transport
  model

abstract:
  We extend our recent study of chiral magnetic effect in relativistic heavy
ion collisions based on an anomalous transport model by including also the
chiral vortical effect. We find that although vorticities in the chirally
restored quark matter, which result from the large angular momentum in
non-central collisions, can generate an axial charge dipole moment in the
transverse plane of a heavy ion collision, it does not produce a difference in
the eccentricities of negatively and positively charged particles. As a result,
including the chiral vortical effect alone cannot lead to a splitting between
the elliptic flows of negatively and positively charged particles. On the other
hand, negatively and positively charged particles do develop a splitting in
their elliptic flows if the effect due to a strong and long-lived magnetic
field is also included. However, to have a positive slope in the dependence of
the elliptic flow splitting on the charge asymmetry of the quark matter, as
seen in experiments, requires the neglect of the effect of the Lorentz force.
In this case, an elliptic flow splitting appears even at vanishing charge
asymmetry.


title:
Van der Waals interaction between a moving nano-cylinder and a liquid
  thin film

abstract:
  We study the static and dynamic interaction between a horizontal cylindrical
nano-probe and a thin liquid film. The effects of the physical and geometrical
parameters, with a special focus on the film thickness, the probe speed, and
the distance between the probe and the free surface are analyzed. Deformation
profiles have been computed numerically from a Reynolds lubrication equation,
coupled to a modified Young-Laplace equation, which takes into account the
probe/liquid and the liquid/substrate non-retarded van der Waals interactions.
We have found that the film thickness and the probe speed have a significant
effect on the threshold separation distance below which the jump-to-contact
instability is triggered. These results encourage the use of horizontal
cylindrical nano-probes to scan thin liquid films, in order to determine either
the physical or geometrical properties of the latter, through the measurement
of interaction forces.

categories: cond-mat.mes-hall cond-mat.mtrl-sci cond-mat.soft physics.flu-dyn physics.ins-det


title:
A general trace formula for the differential operator on a segment with
  the last coefficient perturbed by a finite signed measure

abstract:
  A first order trace formula is obtained for a regular differential operator
perturbed by a finite signed measure multiplication operator.


title:
A New Two-Fluid Radiation-Hydrodynamical Model for X-ray Pulsar
  Accretion Columns

abstract:
  Previous research centered on the hydrodynamics in X-ray pulsar accretion
columns has largely focused on the single-fluid model, in which the
super-Eddington luminosity inside the column decelerates the flow to rest at
the stellar surface. This type of model has been relatively successful in
describing the overall properties of the accretion flows, but it does not
account for the possible dynamical effect of the gas pressure. On the other
hand, the most successful radiative transport models for pulsars generally do
not include a rigorous treatment of the dynamical structure of the column,
instead assuming an ad hoc velocity profile. In this paper, we explore the
structure of X-ray pulsar accretion columns using a new, self-consistent,
"two-fluid" model, which incorporates the dynamical effect of the gas and
radiation pressure, the dipole variation of the magnetic field, the
thermodynamic effect of all of the relevant coupling and cooling processes, and
a rigorous set of physical boundary conditions. The model has six free
parameters, which we vary in order to approximately fit the phase-averaged
spectra in Her X-1, Cen X-3, and LMC X-4. In this paper, we focus on the
dynamical results, which shed new light on the surface magnetic field strength,
the inclination of the magnetic field axis relative to the rotation axis, the
relative importance of gas and radiation pressure, and the radial variation of
the ion, electron, and inverse-Compton temperatures. The results obtained for
the X-ray spectra are presented in a separate paper.


title: Shortcuts for the Circle

abstract:
  Let $C$ be the unit circle in $\mathbb{R}^2$. We can view $C$ as a plane
graph whose vertices are all the points on $C$, and the distance between any
two points on $C$ is the length of the smaller arc between them. We consider a
graph augmentation problem on $C$, where we want to place $k\geq 1$
\emph{shortcuts} on $C$ such that the diameter of the resulting graph is
minimized.
  We analyze for each $k$ with $1\leq k\leq 7$ what the optimal set of
shortcuts is. Interestingly, the minimum diameter one can obtain is not a
strictly decreasing function of~$k$. For example, with seven shortcuts one
cannot obtain a smaller diameter than with six shortcuts. Finally, we prove
that the optimal diameter is $2 + \Theta(1/k^{\frac{2}{3}})$ for any~$k$.


title: Release-free silicon-on-insulator cavity optomechanics

abstract:
  We demonstrate optically coupled nanomechanical resonators fabricated on
silicon-on-insulator. Silicon fin waveguides are used to control the dispersion
of mechanical waves and engineer localized resonances by modulation of the fin
properties. A photonic crystal cavity is designed to localize laser light near
the fin and the mechanical motion is read out and modified by radiation
pressure back-action. We expect devices and systems made from similar
structures to enable co-integration of signal transduction and processing
capabilities via electronic, photonic, and phononic degrees freedom in a single
scalable platform.


title: Evidence for a Localised Source of the Argon in the Lunar Exosphere

abstract:
  We perform the first tests of various proposed explanations for observed
features of the Moon's argon exosphere, including models of: spatially varying
surface interactions; a source that reflects the lunar near-surface potassium
distribution; and temporally varying cold trap areas. Measurements from the
Lunar Atmosphere and Dust Environment Explorer (LADEE) and the Lunar Atmosphere
Composition Experiment (LACE) are used to test whether these models can
reproduce the data. The spatially varying surface interactions hypothesized in
previous work cannot reproduce the persistent argon enhancement observed over
the western maria. They also fail to match the observed local time of the
near-sunrise peak in argon density, which is the same for the highland and mare
regions, and is well reproduced by simple surface interactions with a
ubiquitous desorption energy of 28 kJ/mol. A localised source can explain the
observations, with a trade-off between an unexpectedly localised source or an
unexpectedly brief lifetime of argon atoms in the exosphere. To match the
observations, a point-like source requires source and loss rates of
~$1.9\times10^{21}$ atoms/s. A more diffuse source, weighted by the
near-surface potassium, requires much higher rates of ~$1.1\times10^{22}$
atoms/s, corresponding to a mean lifetime of just 1.4 lunar days. We do not
address the mechanism for producing a localised source, but demonstrate that
this appears to be the only model that can reproduce the observations. Large,
seasonally varying cold traps could explain the long-term fluctuation in the
global argon density observed by LADEE, but not that by LACE.


title: Cycles, derived categories, and rationality

abstract:
  Our main goal is to give a sense of recent developments in the (stable)
rationality problem from the point of view of unramified cohomology and
0-cycles as well as derived categories and semiorthogonal decompositions, and
how these perspectives intertwine and reflect each other. In particular, in the
case of algebraic surfaces, we explain the relationship between Bloch's
conjecture, Chow-theoretic decompositions of the diagonal, categorical
representability, and the existence of phantom subcategories of the derived
category.


title: Testing the fit of relational models

abstract:
  Relational models generalize log-linear models to arbitrary discrete sample
spaces by specifying effects associated with any subsets of their cells. A
relational model may include an overall effect, pertaining to every cell after
a reparameterization, and in this case, the properties of the maximum
likelihood estimates (MLEs) are analogous to those computed under traditional
log-linear models, and the goodness-of-fit tests are also the same. If an
overall effect is not present in any reparameterization, the properties of the
MLEs are considerably different, and the Poisson and multinomial MLEs are not
equivalent. In the Poisson case, if the overall effect is not present, the
observed total is not always preserved by the MLE, and thus, the likelihood
ratio statistic is not identical with twice the Kullback-Leibler divergence.
However, as demonstrated, its general form may be obtained from the Bregman
divergence. The asymptotic equivalence of the Pearson chi-squared and
likelihood ratio statistics holds, but the generality considered here requires
extended proofs.


title: Conservative methods for dynamical systems

abstract:
  We show a novel systematic way to construct conservative finite difference
schemes for quasilinear first-order system of ordinary differential equations
with conserved quantities. In particular, this includes both autonomous and
non-autonomous dynamical systems with conserved quantities of arbitrary forms,
such as time-dependent conserved quantities. Sufficient conditions to construct
conservative schemes of arbitrary order are derived using the multiplier
method. General formulas for first-order conservative schemes are constructed
using divided difference calculus. New conservative schemes are found for
various dynamical systems such as Euler's equation of rigid body rotation,
Lotka-Volterra systems, the planar restricted three-body problem and the damped
harmonic oscillator.


title: Precursors of Short Gamma-Ray Bursts in the SPI-ACS/INTEGRAL Experiment

abstract:
  We have analyzed the light curves of 519 short gamma-ray bursts (GRBs)
detected in the SPI-ACS/INTEGRAL experiment from December 2002 to May 2014 to
search for precursors. Both the light curves of 519 individual events and the
averaged light curve of 372 brightest bursts have been analyzed. In a few
cases, we have found and thoroughly studied precursor candidates based on
SPI-ACS/INTEGRAL, GBM/Fermi, and LAT/Fermi data. A statistical analysis of the
averaged light curve for the entire sample of short bursts has revealed no
regular precursor. Upper limits for the relative intensity of precursors have
been estimated. No convincing evidence for the existence of precursors of short
GRBs has been found. We show that the fraction of short GRBs with precursors is
less than 0.4% of all short bursts.


title: Dynamical crossovers in prethermal critical states

abstract:
  We study the prethermal dynamics of an interacting quantum field theory with
a N-component order parameter and $O(N)$ symmetry, suddenly quenched in the
vicinity of a dynamical critical point. Depending on the initial conditions,
the evolution of the order parameter, and of the response and correlation
functions, can exhibit a temporal crossover between universal dynamical scaling
regimes governed, respectively, by a quantum and a classical prethermal fixed
point, as well as a crossover from a Gaussian to a non-Gaussian prethermal
dynamical scaling. Together with a recent experiment, this suggests that
quenches may be used in order to explore the rich variety of dynamical critical
points occurring in the non-equilibrium dynamics of a quantum many-body system.
We illustrate this fact by using a combination of renormalization group
techniques and a non-perturbative large-$N$ limit.


title: TeV Solar Gamma Rays From Cosmic-Ray Interactions

abstract:
  The Sun is a bright source of GeV gamma rays, due to cosmic rays interacting
with solar matter and photons. Key aspects of the underlying processes remain
mysterious. The emission in the TeV range, for which there are neither
observational nor theoretical studies, could provide crucial clues. The new
experiments HAWC (running) and LHAASO (planned) can look at the Sun with
unprecedented sensitivity. In this paper, we predict the very high-energy (up
to 1000 TeV) gamma-ray flux from the solar disk and halo, due to cosmic-ray
hadrons and electrons ($e^++e^-$), respectively. We neglect solar magnetic
effects, which is valid at TeV energies; at lower energies, this gives a
theoretical lower bound on the disk flux and a theoretical upper bound on the
halo flux. We show that the solar-halo gamma-ray flux allows the first test of
the $\sim 5$--70 TeV cosmic-ray electron spectrum. Further, we show that HAWC
can immediately make an even stronger test with nondirectional observations of
cosmic-ray electrons. Together, these gamma-ray and electron studies will
provide new insights about the local density of cosmic rays and their
interactions with the Sun and its magnetic environment. These studies will also
be an important input to tests of new physics, including dark matter.


title:
High-Q photonic resonators and electro-optic coupling using
  silicon-on-lithium-niobate

abstract:
  Future quantum networks in which superconducting quantum processors are
connected via optical links, will require microwave-to-optical photon
converters that preserve entanglement. A doubly-resonant electro-optic
modulator (EOM) is a promising platform to realize this conversion. Here, we
present our progress towards building such a modulator by demonstrating the
optically-resonant half of the device. We demonstrate high quality factor ring,
disk and photonic crystal resonators using a hybrid silicon-on-lithium-niobate
material system. Optical quality factors up to 730,000 are achieved,
corresponding to propagation loss of 0.8 dB/cm. We also use the electro-optic
effect to modulate the resonance frequency of a photonic crystal cavity,
achieving a electro-optic modulation coefficient between 1 and 2 pm/V. In
addition to quantum technology, we expect that our results will be useful both
in traditional silicon photonics applications and in high-sensitivity
acousto-optic devices.


title:
How geometric frustration shapes twisted fibers, inside and out:
  Competing morphologies of chiral filament assembly

abstract:
  Chirality frustrates and shapes the assembly of flexible filaments in
rope-like, twisted bundles and fibers by introducing gradients of both filament
shape (i.e. curvature) and packing throughout the structure. Previous models of
chiral filament bundle formation have shown that this frustration gives rise to
several distinct morphological responses, including self-limiting bundle
widths, anisotropic domain (tape-like) formation and topological defects in the
lateral inter-filament order. In this paper, we employ a combination of
continuum elasticity theory and discrete filament bundle simulations to explore
how these distinct morphological responses compete in the broader phase diagram
of chiral filament assembly. We show that the most generic model of bundle
formation exhibits at least four classes of equilibrium structure --
finite-width, twisted bundles with isotropic and anisotropic shapes, with and
without topological defects, as well as bulk phases of untwisted, columnar
assembly (i.e. "frustration escape"). These competing equilibrium morphologies
are selected by only a relatively small number of parameters describing
filament assembly: bundle surface energy, preferred chiral twist and stiffness
of chiral filament interactions, and mechanical stiffness of filaments and
their lateral interactions. Discrete filament bundle simulations test and
verify continuum theory predictions for dependence of bundle structure (shape,
size and packing defects of 2D cross section) on these key parameters.


title: Towards Background-free RENP using a Photonic Crystal Waveguide

abstract:
  We study how to suppress multiphoton emission background in QED against
radiative emission of neutrino pair (RENP) from atoms. We purse the possibility
of background suppression using the photonic band structure of periodic
dielectric media, called photonic crystals. The modification of photon emission
rate in photonic crystal waveguides is quantitatively examined to clarify the
condition of background-free RENP.


title: VLBI studies of TANAMI radio galaxies

abstract:
  Radio galaxies are relatively faint at $\gamma$-ray energies, where they make
up only 1-2% of all AGN detected by Fermi-LAT. However, they offer a unique
perspective to study the intrinsic properties of AGN jets. For this reason, the
combination of $\gamma$-ray and multi-wavelength data with high-resolution VLBI
monitoring is a powerful tool to tackle the basic unanswered questions about
AGN jets. Here we present preliminary results from a sample study of radio
galaxies in the Southern hemisphere observed by the TANAMI VLBI monitoring
program. We obtain high-resolution maps at 8.4 and 22.3 GHz, and study the jet
kinematics using multi-epoch data. We present a preliminary kinematic analysis
for the peculiar $\gamma$-ray AGN PKS 0521$-$36.


title: Detection of the atmosphere of the 1.6 Earth mass exoplanet GJ 1132b

abstract:
  Detecting the atmospheres of low-mass low-temperature exoplanets is a
high-priority goal on the path to ultimately detect biosignatures in the
atmospheres of habitable exoplanets. High-precision HST observations of several
super-Earths with equilibrium temperatures below 1000K have to date all
resulted in featureless transmission spectra, which have been suggested to be
due to high-altitude clouds. We report the detection of an atmospheric feature
in the atmosphere of a 1.6 Mearth transiting exoplanet, GJ 1132b, with an
equilibrium temperature of ~600K and orbiting a nearby M dwarf. We present
observations of nine transits of the planet obtained simultaneously in the griz
and JHK passbands. We find an average radius of 1.43 +/- 0.16 Rearth for the
planet, averaged over all the passbands, and a radius of 0.255 +/- 0.023 Rsun
for the star, both of which are significantly greater than previously found.
The planet radius can be decomposed into a "surface radius" at ~1.375 Rearth
overlaid by atmospheric features which increase the observed radius in the z
and K bands. The z-band radius is 4sigma higher than the continuum, suggesting
a strong detection of an atmosphere. We deploy a suite of tests to verify the
reliability of the transmission spectrum, which are greatly helped by the
existence of repeat observations. The large z-band transit depth indicates
strong opacity from H2O and/or CH4 or a hitherto unconsidered opacity. A
surface radius of 1.375 +/- 0.16 Rearth allows for a wide range of interior
compositions ranging from a nearly Earth-like rocky interior, with ~70%
silicate and ~30% Fe, to a substantially H2O-rich water world.


title: The Hawaii Infrared Parallax Program. II. Young Ultracool Field Dwarfs

abstract:
  (Abridged) We present a large, uniform analysis of young (~10-150 Myr)
ultracool dwarfs, based on new high-precision IR parallaxes for 68 objects. We
find that low-gravity (VL-G) late-M and L dwarfs form a continuous sequence in
IR color-magnitude diagrams, separate from field objects and current
theoretical models. VL-G objects also appear distinct from young substellar
(brown dwarf and exoplanet) companions, suggesting the two populations have a
different range of physical properties. In contrast, at the L/T transition,
young, old, and peculiar objects all span a narrow range in near-IR absolute
magnitudes. At a given spectral type, the IR absolute magnitudes of young
objects can be offset from ordinary field dwarfs, with the largest offsets
occurring in the Y and J bands for late-M dwarfs (brighter than the field) and
mid/late-L dwarfs (fainter than the field). Overall, low-gravity (VL-G) objects
have the most uniform photometric behavior while intermediate-gravity (INT-G)
objects are more diverse, suggesting a third governing parameter beyond
spectral type and gravity class. We examine the moving group memberships for
all young ultracool dwarfs with parallaxes, changing/refuting the status of 23
objects and fortifying the status of another 28 objects. We use our resulting
age-calibrated sample to establish empirical young isochrones and find a
declining frequency of VL-G objects relative to INT-G objects with increasing
age. Notable objects in our sample include high-velocity INT-G objects; very
red, late-L dwarfs with high surface gravities; candidate disk-bearing members
of the MBM20 cloud and beta Pic moving group; and very young distant
interlopers. Finally, we provide a comprehensive summary of the absolute
magnitudes and spectral classifications of 102 young ultracool dwarfs, found in
the field and as substellar companions to young stars.


title: A Gaussian Variational Approach to cMERA for Interacting Fields

abstract:
  We use the Gaussian variational principle to apply cMERA to interacting
quantum field theories in arbitrary spacetime dimensions. By establishing a
correspondence between the first two terms in the variational expansion and the
Gaussian Effective Potential, we can exactly solve for a variational
approximation to the cMERA entangler. As examples, we treat scalar $\varphi^4$
theory and the Gross-Neveu model and extract non-perturbative behavior. We also
comment on the connection between generalized squeezed coherent states and more
generic entanglers.


title: HI-to-H2 Transition Layers in the Star-Forming Region W43

abstract:
  The process of atomic-to-molecular (HI-to-H$_2$) gas conversion is
fundamental for molecular-cloud formation and star formation. 21 cm
observations of the star-forming region W43 revealed extremely high HI column
densities, of 120-180 M$_{\odot}$ pc$^{-2}$, a factor of 10-20 larger than
predicted by HI-to-H$_2$ transition theories. We analyze the observed HI with
an HI-to-H$_2$ transition theoretical model, and show that the
theory-observation discrepancy cannot be explained by the intense radiation in
W43, nor by variations of the assumed volume density or H$_2$ formation-rate
coefficient. We show that the large observed HI columns are naturally explained
by several ($9-22$) HI-to-H$_2$ transition layers, superimposed along the
sightlines of W43. We discuss other possible interpretations such as a
non-steady-state scenario, and inefficient dust absorption. The case of W43
suggests that HI thresholds reported in extra-galactic observations are
probably not associated with a single HI-to-H$_2$ transition, but are rather a
result of several transition layers (clouds) along the sightlines, beam-diluted
with diffuse inter-cloud gas.


title:
Obscured Active Galactic Nuclei triggered in compact star-forming
  galaxies

abstract:
  We present a structural study of 182 obscured Active Galactic Nuclei (AGNs)
at z<=1.5, selected in the COSMOS field from their extreme infrared to X-ray
luminosity ratio and their negligible emission at optical wavelengths. We fit
optical to far-infrared spectral energy distributions and analyze deep HST
imaging to derive the physical and morphological properties of their host
galaxies. We find that such galaxies are more compact than normal star-forming
sources at similar redshift and stellar mass, and we show that it is not an
observational bias related to the emission of the AGN. Based on the
distribution of their UVJ colors, we also argue that this increased compactness
is not due to the additional contribution of a passive bulge. We thus postulate
that a vast majority of obscured AGNs reside in galaxies undergoing dynamical
compaction, similar to processes recently invoked to explain the formation of
compact star-forming sources at high redshift.


title: Turbulent magnetic relaxation in pulsar wind nebulae

abstract:
  We present a model for magnetic energy dissipation in a pulsar wind nebula.
Better understanding of this process is required to assess the likelihood that
certain astrophysical transients may be powered by the spin-down of a
"millisecond magnetar." Examples include superluminous supernovae, gamma-ray
bursts, and anticipated electromagnetic counterparts to gravitational wave
detections of binary neutron star coalescence. Our model leverages recent
progress in the theory of turbulent magnetic relaxation to specify a
dissipative closure of the stationary magnetohydrodynamic (MHD) wind equations,
yielding predictions of the magnetic energy dissipation rate throughout the
nebula. Synchrotron losses are treated self-consistently. To demonstrate the
model's efficacy, we show that it can reproduce many features of the Crab
Nebula, including its expansion speed, radiative efficiency, peak photon
energy, and mean magnetic field strength. Unlike ideal MHD models of the Crab
(which lead to the so-called sigma problem) our model accounts for the
transition from ultra to weakly magnetized plasma flow, and for the associated
heating of relativistic electrons. We discuss how the predicted heating rates
may be utilized to improve upon models of particle transport and acceleration
in pulsar wind nebulae. We also discuss implications for the Crab Nebula's
gamma-ray flares, and point out potential modifications to models of
astrophysical transients invoking the spin-down of a millisecond magnetar.


title:
Accretion and Magnetic Reconnection in the Classical T Tauri Binary DQ
  Tau

abstract:
  Binary star-formation theory predicts that close binaries (a<100 AU) will
experience periodic pulsed accretion events as streams of material form at the
inner edge of a circumbinary disk, cross a dynamically cleared gap, and feed
circumstellar disks or accrete directly onto the stars. The archetype for the
pulsed-accretion theory is the eccentric, short-period, classical T Tauri
binary DQ Tau. Low-cadence (~daily) broadband photometry has shown brightening
events near most periastron passages, just as numerical simulations would
predict for an eccentric binary. Magnetic reconnection events (flares) during
the collision of stellar magnetospheres near periastron could, however, produce
the same periodic, broadband behavior when observed at a one-day cadence. To
reveal the dominate physical mechanism seen in DQ Tau's low-cadence
observations, we have obtained continuous, moderate-cadence, multi-band
photometry over 10 orbital periods, supplemented with 27 nights of
minute-cadence photometry centered on 4 separate periastron passages. While
both accretion and stellar flares are present, the dominant timescale and
morphology of brightening events are characteristic of accretion. On average,
the mass accretion rate increases by a factor of 5 near periastron, in good
agreement with recent models. Large variability is observed in the morphology
and amplitude of accretion events from orbit-to-orbit. We argue this is due to
the absence of stable circumstellar disks around each star, compounded by
inhomogeneities at the inner edge of the circumbinary disk and within the
accretion streams themselves. Quasi-periodic apastron accretion events are also
observed, which are not predicted by binary accretion theory.