title:
A generalization of unimodular gravity with vacuum-matter energy
  exchange

abstract:
  An effective theory of gravity in the infrared is proposed, which involves
the determinant of the metric relative to the determinant of a prior metric
taken to be that of Minkowski spacetime. This effective theory can be
interpreted as a generalization of unimodular gravity. In a cosmological
context with ultrarelativistic or cold matter, the resulting field equations
have only one solution, empty Minkowski spacetime (selected by the prior metric
of the theory). The introduction of energy exchange between vacuum and matter
gives rise to nonstatic cosmic solutions. It is found that Minkowski spacetime
(from the prior metric) appears as an attractor of the dynamic equations. A
further result is that energy-momentum conservation of any localized material
system is violated in a nonconstant gravitational background. The impact for
experiment appears, however, negligible if the vacuum-energy mass scale is of
order meV.


title: Shot noise in NS junctions with Weyl superconductor

abstract:
  We demonstrate that current-current correlations (in particular the shot
noise), can be used to study the intrinsic superconductivity in a slightly
doped Weyl semi-metal. The systems studied is an N-WS tunneling junction where
the left electrode is a normal metal while the right electrode is a Weyl
superconductor (WS).
  The superconductivity supports surface state with crossed flat bands thereby
impact the low energy spectrum.
  This spectrum displays a modified density of states in the gap region that
strongly affects transport characteristics of the N-WS junction. The Fano
factor is calculated as function of the applied bias, and shown to be dependent
essentially on the orientation of the surface of WS relative to the tunneling
direction. If this orientation supports the occurrence of low energy state,
then the shot noise power decreases with decreasing voltage, a property similar
to that prevailing in a junction with Majorana bound state.


title: The transfer map of free loop spaces

abstract:
  For any perfect fibration $E \rightarrow B$, there is a "free loop transfer
map" $LB_+ \rightarrow LE_+$, defined using topological Hochschild homology. We
prove that this transfer is compatible with the Becker-Gottlieb transfer,
allowing us to extend a result of Dorabia\l{}a and Johnson on the transfer map
in Waldhausen's $A$-theory. In the case where $E \rightarrow B$ is a smooth
fiber bundle, we also give a concrete geometric model for the free loop
transfer in terms of Pontryagin-Thom collapse maps. We recover the previously
known computations of the free loop transfer due to Schlichtkrull, and make a
few new computations as well.


title:
Existence of 1D vectorial Absolute Minimisers in $L^\infty$ under
  minimal assumptions

abstract:
  We prove the existence of vectorial Absolute Minimisers in the sense of
Aronsson to the supremal functional $E_\infty(u,\Omega') =
\|\mathscr{L}(\cdot,u,D u)\|_{L^\infty(\Omega')}$, $\Omega'\Subset \Omega$,
applied to $W^{1,\infty}$ maps $u:\Omega\subseteq \mathbb{R}\longrightarrow
\mathbb{R}^N$ with given boundary values. The assumptions on $\mathscr{L}($ are
minimal, improving earlier existence results previously established by
Barron-Jensen-Wang and by the second author.


title:
First principles calculation of the valence band offsets for \b{eta}-
  polytype of A3B6 layered crystals

abstract:
  The valence band offsets (VBO) for the \b{eta}-type A3B6 layered compounds
depending on the thickness of the crystals have been investigated from the
first principles, based on the density functional theory. To simulate the
structure of a given thickness the periodic slab model was used. Two adjacent
crystal slabs consisting of several layers were separated by a vacuum region of
two-layer width. It is shown that at the crystal thickness more than 12 layers,
photothreshold practically becomes independent on the thickness of the crystal.


title: A Vector Equilibrium Problem for Muttalib-Borodin Biorthogonal Ensembles

abstract:
  The Muttalib-Borodin biorthogonal ensemble is a joint density function for
$n$ particles on the positive real line that depends on a parameter $\theta$.
There is an equilibrium problem that describes the large $n$ behavior. We show
that for rational values of $\theta$ there is an equivalent vector equilibrium
problem.


title: metaSPAdes: a new versatile de novo metagenomics assembler

abstract:
  While metagenomics has emerged as a technology of choice for analyzing
bacterial populations, assembly of metagenomic data remains difficult thus
stifling biological discoveries. metaSPAdes is a new assembler that addresses
the challenge of metagenome analysis and capitalizes on computational ideas
that proved to be useful in assemblies of single cells and highly polymorphic
diploid genomes. We benchmark metaSPAdes against other state-of-the-art
metagenome assemblers across diverse da-tasets and demonstrate that it results
in high-quality assemblies.


title:
Fast Computation of Isomorphisms Between Finite Fields Using Elliptic
  Curves

abstract:
  We propose a randomized algorithm to compute isomorphisms between finite
fields using elliptic curves. To compute an isomorphism between two fields of
cardinality $q^n$, our algorithm takes $$n^{1+o(1)} \log^{1+o(1)}q +
\max_{\ell} \left(\ell^{n_\ell + 1+o(1)} \log^{2+o(1)} q + O(\ell
\log^5q)\right)$$ time, where $\ell$ runs through primes dividing $n$ but not
$q(q-1)$ and $n_\ell$ denotes the highest power of $\ell$ dividing $n$. Prior
to this work, the best known run time dependence on $n$ was quadratic. Our run
time dependence on $n$ is at worst quadratic but is subquadratic if $n$ has no
large prime factor. In particular, the $n$ for which our run time is nearly
linear in $n$ have natural density at least $3/10$. The crux of our approach is
finding a point on an elliptic curve of a prescribed prime power order or
equivalently finding preimages under the Lang map on elliptic curves over
finite fields. We formulate this as an open problem whose resolution would
solve the finite field isomorphism problem with run time nearly linear in $n$.


title:
Reservoir computing for spatiotemporal signal classification without
  trained output weights

abstract:
  Reservoir computing is a recently introduced machine learning paradigm that
has been shown to be well-suited for the processing of spatiotemporal data.
Rather than training the network node connections and weights via
backpropagation in traditional recurrent neural networks, reservoirs instead
have fixed connections and weights among the `hidden layer' nodes, and
traditionally only the weights to the output layer of neurons are trained using
linear regression. We claim that for signal classification tasks one may forgo
the weight training step entirely and instead use a simple supervised
clustering method based upon principal components of norms of reservoir states.
The proposed method is mathematically analyzed and explored through numerical
experiments on real-world data. The examples demonstrate that the proposed may
outperform the traditional trained output weight approach in terms of
classification accuracy and sensitivity to reservoir parameters.


title: From leaf to tree: upscaling of artificial photosynthesis

abstract:
  Energy storage becomes crucial for energy systems with an increasing share of
renewable energy sources. Artificial photosynthesis, in particular photovoltaic
water splitting, provides both sustainable energy generation and energy storage
in the form of hydrogen. However, only a few concepts for scalable devices were
reported in the literature. Here, we introduce a new concept which, by design,
is scalable and compatible with every thin-film photovoltaic technology. The
concept allows for independent geometrical optimization of the photovoltaic and
the electrochemical part. The scalability is achieved by continuous mirroring
of a base unit. We demonstrate a fully integrated, wireless device with a
stable and bias-free operation for 40 hours. The concept was scaled to an area
of 64 cm2 comprising 13 base units and exhibited a solar-to-hydrogen efficiency
of 3.9%. The concept and its successful realization is an important
contribution towards the large scale application of artificial photosynthesis.


title: Fully-Automatic Synapse Prediction and Validation on a Large Data Set

abstract:
  Extracting a connectome from an electron microscopy (EM) data set requires
identification of neurons and determination of synapses between neurons. As
manual extraction of this information is very time-consuming, there has been
extensive research effort to automatically segment the neurons to help guide
and eventually replace manual tracing. Until recently, there has been
comparatively less research on automatically detecting the actual synapses
between neurons. This discrepancy can, in part, be attributed to several
factors: obtaining neuronal shapes is a prerequisite first step in extracting a
connectome, manual tracing is much more time-consuming than annotating
synapses, and neuronal contact area can be used as a proxy for synapses in
determining connections.
  However, recent research has demonstrated that contact area alone is not a
sufficient predictor of synaptic connection. Moreover, as segmentation has
improved, we have observed that synapse annotation is consuming a more
significant fraction of overall reconstruction time. This ratio will only get
worse as segmentation improves, gating overall possible speed-up. Therefore, we
address this problem by developing algorithms that automatically detect
pre-synaptic neurons and their post-synaptic partners. In particular,
pre-synaptic structures are detected using a Deep and Wide Multiscale Recursive
Network, and post-synaptic partners are detected using a MLP with features
conditioned on the local segmentation.
  This work is novel because it requires minimal amount of training, leverages
advances in image segmentation directly, and provides a complete solution for
polyadic synapse detection. We further introduce novel metrics to evaluate our
algorithm on connectomes of meaningful size. These metrics demonstrate that
complete automatic prediction can be used to effectively characterize most
connectivity correctly.


title: A universal gate for fixed-frequency qubits via a tunable bus

abstract:
  A challenge for constructing large circuits of superconducting qubits is to
balance addressability, coherence and coupling strength. High coherence can be
attained by building circuits from fixed-frequency qubits, however, leading
techniques cannot couple qubits that are far detuned. Here we introduce a
method based on a tunable bus which allows for the coupling of two
fixed-frequency qubits even at large detunings. By parametrically oscillating
the bus at the qubit-qubit detuning we enable a resonant exchange (XX+YY)
interaction. We use this interaction to implement a 183ns two-qubit iSWAP gate
between qubits separated in frequency by 854MHz with a measured average
fidelity of 0.9823(4) from interleaved randomized benchmarking. This gate may
be an enabling technology for surface code circuits and for analog quantum
simulation.


title:
A Blind Search for Prompt Gamma-ray Counterparts of Fast Radio Bursts
  with Fermi-LAT Data

abstract:
  Fast Radio Bursts (FRBs) are a mysterious flash phenomenon detected in radio
wavelengths with a duration of only a few milliseconds, and they may also have
prompt gamma-ray flashes. Here we carry out a blind search for msec-duration
gamma-ray flashes using the 7-year Fermi Large Area Telescope (Fermi-LAT)
all-sky gamma-ray data. About 100 flash candidates are detected, but after
removing those associated with bright steady point sources, we find no flash
events at high Galactic latitude region (|b|>20 deg). Events at lower latitude
regions are consistent with statistical flukes originating from the diffuse
gamma-ray background. From these results, we place an upper limit on the GeV
gamma-ray to radio flux ratio of FRBs as xi \equiv (nu L_nu)_gamma / (nu
L_nu)_radio < 10^8, depending on the assumed FRB rate evolution. This limit is
comparable with the largest value found for pulsars, though xi of pulsars is
distributed in a wide range. We also compare this limit with the spectral
energy distribution of the 2004 giant flare of the magnetar SGR 1806-20.


title: G\"odel's Natural Deduction

abstract:
  This is a companion to a paper by the authors entitled "G\"odel on
deduction", which examined the links between some philosophical views ascribed
to G\"odel and general proof theory. When writing that other paper, the authors
were not acquainted with a system of natural deduction that G\"odel presented
with the help of Gentzen's sequents, which amounts to Ja\'skowski's natural
deduction system of 1934, and which may be found in G\"odel's unpublished notes
for the elementary logic course he gave in 1939 at the University of Notre
Dame. Here one finds a presentation of this system of G\" odel accompanied by a
brief reexamination in the light of the notes of some points concerning his
interest in sequents made in the preceding paper. This is preceded by a brief
summary of G\"odel's Notre Dame course, and is followed by comments concerning
G\"odel's natural deduction system.


title: Construction of automorphisms of hyperk\"ahler manifolds

abstract:
  Let $M$ be an irreducible holomorphic symplectic (hyperk\"ahler) manifold. If
$b_2(M)\geq 5$, we construct a deformation $M'$ of $M$ which admits a
symplectic automorphism of infinite order. This automorphism is hyperbolic,
that is, its action on the space of real $(1,1)$-classes is hyperbolic. If
$b_2(M) \geq 14$, similarly, we construct a deformation which admits a
parabolic automorphism.


title: Interacting Quintessence in a New Scalar-Torsion Gravity

abstract:
  In the framework of teleparallel equivalent of general relativity, we study a
gravity theory where a scalar field beyond its minimal coupling, is also
coupled with the vector torsion through a non-minimal derivative coupling.
After a suitable choice of auxiliary variables that allows us to perform the
phase-space analysis of the model we obtain the critical points and their
stability. While there is no scaling attractor in non-interacting scenario, by
considering an interaction between dark energy and dark matter, we find scaling
attractors in which the fractional densities of dark energy and matter are
non-vanishing constants over there. The universe can evolve to these scaling
attractors regardless of initial conditions and the cosmological coincidence
problem could be alleviated without fine-tunings.


title:
AptaTRACE: Elucidating Sequence-Structure Binding Motifs by Uncovering
  Selection Trends in HT-SELEX Experiments

abstract:
  Aptamers, short synthetic RNA/DNA molecules binding specific targets with
high affinity and specificity, are utilized in an increasing spectrum of
bio-medical applications. Aptamers are identified in vitro via the Systematic
Evolution of Ligands by Exponential Enrichment (SELEX) protocol. SELEX selects
binders through an iterative process that, starting from a pool of random
ssDNA/RNA sequences, amplifies target-affine species through a series of
selection cycles. HT-SELEX, which combines SELEX with high throughput
sequencing, has recently transformed aptamer development and has opened the
field to even more applications. HT-SELEX is capable of generating over half a
billion data points, challenging computational scientists with the task of
identifying aptamer properties such as sequence structure motifs that determine
binding. While currently available motif finding approaches suggest partial
solutions to this question, none possess the generality or scalability required
for HT-SELEX data, and they do not take advantage of important properties of
the experimental procedure.
  We present AptaTRACE, a novel approach for the identification of
sequence-structure binding motifs in HT-SELEX derived aptamers. Our approach
leverages the experimental design of the SELEX protocol and identifies
sequence-structure motifs that show a signature of selection. Because of its
unique approach, AptaTRACE can uncover motifs even when these are present in
only a minuscule fraction of the pool. Due to these features, our method can
help to reduce the number of selection cycles required to produce aptamers with
the desired properties, thus reducing cost and time of this rather expensive
procedure. The performance of the method on simulated and real data indicates
that AptaTRACE can detect sequence-structure motifs even in highly challenging
data.


title:
Monodromy dependence and connection formulae for isomonodromic tau
  functions

abstract:
  We discuss an extension of the Jimbo-Miwa-Ueno differential 1-form to a form
closed on the full space of extended monodromy data of systems of linear
ordinary differential equations with rational coefficients. This extension is
based on the results of M. Bertola generalizing a previous construction by B.
Malgrange. We show how this 1-form can be used to solve a long-standing problem
of evaluation of the connection formulae for the isomonodromic tau functions
which would include an explicit computation of the relevant constant factors.
We explain how this scheme works for Fuchsian systems and, in particular,
calculate the connection constant for generic Painlev\'e VI tau function. The
result proves the conjectural formula for this constant proposed in
\cite{ILT13}. We also apply the method to non-Fuchsian systems and evaluate
constant factors in the asymptotics of Painlev\'e II tau function.


title: Detector Based Radio Tomographic Imaging

abstract:
  Received signal strength based radio tomographic imaging is a popular
device-free indoor localization method which reconstructs the spatial loss
field of the environment using measurements from a dense wireless network.
Existing methods solve an associated inverse problem using algebraic or
compressed sensing reconstruction algorithms. We propose an alternative imaging
method that reconstructs spatial field of occupancy using a back-projection
based reconstruction algorithm. The introduced system has the following
advantages over the other imaging based methods: i.) significantly lower
computational complexity such that no floating point multiplication is
required; ii.) each link's measured data is compressed to a single bit,
providing improved scalability; iii.) physically significant and repeatable
parameters. The proposed method is validated using measurement data. Results
show that the proposed method achieves the above advantages without loss of
accuracy compared to the other available methods.


title: A Nearly Tight Sum-of-Squares Lower Bound for the Planted Clique Problem

abstract:
  We prove that with high probability over the choice of a random graph $G$
from the Erd\H{o}s-R\'enyi distribution $G(n,1/2)$, the $n^{O(d)}$-time degree
$d$ Sum-of-Squares semidefinite programming relaxation for the clique problem
will give a value of at least $n^{1/2-c(d/\log n)^{1/2}}$ for some constant
$c>0$. This yields a nearly tight $n^{1/2 - o(1)}$ bound on the value of this
program for any degree $d = o(\log n)$. Moreover we introduce a new framework
that we call \emph{pseudo-calibration} to construct Sum of Squares lower
bounds. This framework is inspired by taking a computational analog of Bayesian
probability theory. It yields a general recipe for constructing good
pseudo-distributions (i.e., dual certificates for the Sum-of-Squares
semidefinite program), and sheds further light on the ways in which this
hierarchy differs from others.


title: Hereditary $C^*$-subalgebras of graph $C^*$-algebras

abstract:
  We show that a $C^*$-algebra $\mathfrak{A}$ which is stably isomorphic to a
unital graph $C^*$-algebra, is isomorphic to a graph $C^*$-algebra if and only
if it admits an approximate unit of projections. As a consequence, a hereditary
$C^*$-subalgebra of a unital real rank zero graph $C^*$-algebra is isomorphic
to a graph $C^*$-algebra. Furthermore, if a $C^*$-algebra $\mathfrak{A}$ admits
an approximate unit of projections, then its minimal unitization is isomorphic
to a graph $C^*$-algebra if and only if $\mathfrak{A}$ is stably isomorphic to
a unital graph $C^*$-algebra.


title:
SMC west halo: a slice of the galaxy that is being tidally stripped?
  Star clusters trace age and metallicity gradients

abstract:
  (ABRIDGED) The evolution and structure of the Magellanic Clouds is presently
under debate. The classical scenario where both the Large and Small Magellanic
Clouds (LMC, SMC) are orbiting the Milky Way has been challenged by an
alternative where the LMC and SMC are in their first close passage to our
Galaxy. Detailed studies of stellar populations in the galaxies should
constrain the proposed scenarios. In particular, the west halo of the SMC was
recently characterized with radial trends in age and metallicity which
indicates tidal disruption. We increase the sample of star clusters in the west
halo of the SMC with homogeneous age, metallicity, and distance derivations, to
determine better age and metallicity gradients. Comparisons of observed and
synthetic V,(B-V) colour-magnitude diagrams are used to derive parameters for
west halo star clusters. We derived age and metallicity for the reference
cluster NGC 152 compatible with literature parameters. Age and metallicity
gradients are confirmed in the west halo: 2.6 +/- 0.6 Gyr/deg and -0.19 +/-
0.09 dex/deg, respectively. Age-metallicity relation for the west halo has low
dispersion in metallicity and it is compatible with a burst model of chemical
enrichment. All WH clusters seem to follow the same predicted stellar
distribution, with exception of AM-3 that should belong to the counter-bridge.
Bruck 6 is only 130 +/- 40 Myr old and it could have been formed during a
recent tidal interaction of the SMC-LMC. We suggest that it is crucial to split
the SMC cluster population in groups: main body, wing/bridge, counter-bridge
and west halo. This is the way to analyse the complex star formation and
dynamical history of our neighbour. In particular we show that west halo has
clear age and metallicity gradients and age-metallicity relation, also
compatible with the dynamical model of tidal influence of the LMC over the SMC.


title: On the Dynamics of Glassy Systems

abstract:
  Glassy systems are disordered systems characterized by extremely slow
dynamics. Examples are supercooled liquids, whose dynamics slow down under
cooling. The specific pattern of slowing-down depends on the material
considered. This dependence is poorly understood, in particular, it remains
generally unclear which aspects of the microscopic structures control the
dynamics and other macroscopic properties. Attacking this question is one of
the two main aspects of this dissertation. We have introduced a new class of
models of supercooled liquids, which captures the central aspects of the
correspondence between structure and elasticity on the one hand, the
correlation of structure and thermodynamic and dynamic properties on the other.
Our results shed new light on the temperature-dependence of the topology of
covalent networks, in particular, on the rigidity transition that occurs when
the valence is increased.
  Other questions appear in glassy systems at zero temperature. In that
situation, a glassy system can flow if an external driving force is imposed
above some threshold. The first example we will consider is the erosion of a
riverbed. Experiments support the existence of a threshold forcing, below which
no erosion flux is observed. In this dissertation, we present a novel
microscopic model to describe the erosion near threshold. This model makes new
quantitative predictions for the spatial reparation of the flux. To study
further the self-organization of driven glassy systems, we investigate the
athermal dynamics of mean-field spin glasses. The spin glass self-organizes
into the configurations that are stable, but barely so. Such marginal stability
appears with the presence of a pseudogap in soft excitations. We show that the
emergence of a pseudogap is deeply related to very strong anti-correlations
emerging among soft excitations.


title: Non-abelian gauge extensions for B-decay anomalies

abstract:
  We study the generic features of minimal gauge extensions of the Standard
Model in view of recent hints of lepton-flavor non-universality in
semi-leptonic $b \to s \ell^+ \ell^-$ and $b \to c \ell \nu$ decays. We
classify the possible models according to the symmetry-breaking pattern and the
source of flavor non-universality. We find that in viable models the
$\mathrm{SU(2)}_L$ factor is embedded non-trivially in the extended gauge
group, and that gauge couplings should be universal, hinting to the presence of
new degrees of freedom sourcing non-universality. Finally, we provide an
explicit model that can explain the $B$-decay anomalies in a coherent way and
confront it with the relevant phenomenological constraints.


title:
Different quantum f-divergences and the reversibility of quantum
  operations

abstract:
  The concept of classical $f$-divergences gives a unified framework to
construct and study measures of dissimilarity of probability distributions;
special cases include the relative entropy and the R\'enyi divergences. Various
quantum versions of this concept, and more narrowly, the concept of R\'enyi
divergences, have been introduced in the literature with applications in
quantum information theory; most notably Petz' quasi-entropies (standard
$f$-divergences), Matsumoto's maximal $f$-divergences, measured
$f$-divergences, and sandwiched and $\alpha$-$z$-R\'enyi divergences.
  In this paper we give a systematic overview of the various concepts of
quantum $f$-divergences with a main focus on their monotonicity under quantum
operations, and the implications of the preservation of a quantum
$f$-divergence by a quantum operation. In particular, we compare the standard
and the maximal $f$-divergences regarding their ability to detect the
reversibility of quantum operations. We also show that these two quantum
$f$-divergences are strictly different for non-commuting operators unless $f$
is a polynomial, and obtain some analogous partial results for the relation
between the measured and the standard $f$-divergences.
  We also study the monotonicity of the $\alpha$-$z$-R\'enyi divergences under
the special class of bistochastic maps that leave one of the arguments of the
R\'enyi divergence invariant, and determine domains of the parameters
$\alpha,z$ where monotonicity holds, and where the preservation of the
$\alpha$-$z$-R\'enyi divergence implies the reversibility of the quantum
operation.


title:
One single static measurement predicts wave localization in complex
  structures

abstract:
  A recent theoretical breakthrough has brought a new tool, called
\emph{localization landscape}, to predict the localization regions of vibration
modes in complex or disordered systems. Here, we report on the first experiment
which measures the localization landscape and demonstrates its predictive
power. Holographic measurement of the static deformation under uniform load of
a thin plate with complex geometry provides direct access to the landscape
function. When put in vibration, this system shows modes precisely confined
within the sub-regions delineated by the landscape function. Also the maxima of
this function match the measured eigenfrequencies, while the minima of the
valley network gives the frequencies at which modes become extended. This
approach fully characterizes the low frequency spectrum of a complex structure
from a single static measurement. It paves the way to the control and
engineering of eigenmodes in any vibratory system, especially where a
structural or microscopic description is not accessible.


title: Non-Markovianity in a non-thermal bath

abstract:
  We study the dynamics of an open quantum system interacting with a
non-thermal bath. Here, "non-thermal" means that the bath modes do not need to
have the same temperature, but they have an effective temperature distribution.
We find that, when a quantum system is interacting with such a non-thermal bath
far from thermal equilibrium, it is no longer proper to use any coarse-grained
Markovian description for the system, even when their coupling strength is
quite weak. Especially, when there is coherent transition with strong
interference strength in the quantum system, the Markovian master equation
would bring in a serious problem of negative probability. After we consider
some proper non-Markovian corrections, the problem can be naturally resolved.


title: Circumstellar Debris and Pollution at White Dwarf Stars

abstract:
  Circumstellar disks of planetary debris are now known or suspected to closely
orbit hundreds of white dwarf stars. To date, both data and theory support
disks that are entirely contained within the preceding giant stellar radii, and
hence must have been produced during the white dwarf phase. This picture is
strengthened by the signature of material falling onto the pristine stellar
surfaces; disks are always detected together with atmospheric heavy elements.
The physical link between this debris and the white dwarf host abundances
enables unique insight into the bulk chemistry of extrasolar planetary systems
via their remnants. This review summarizes the body of evidence supporting
dynamically active planetary systems at a large fraction of all white dwarfs,
the remnants of first generation, main-sequence planetary systems, and hence
provide insight into initial conditions as well as long-term dynamics and
evolution.


title:
Breakdown Current Density in BN-Capped Quasi-1D TaSe3 Metallic
  Nanowires: Prospects of Interconnect Applications

abstract:
  We report results of investigation of the current-carrying capacity of
nanowires made from the quasi-1D van der Waals metal tantalum triselenide
capped with quasi-2D boron nitride. The chemical vapor transport method
followed by chemical and mechanical exfoliation were used to fabricate mm-long
TaSe3 wires with lateral dimensions in the 20 to 70 nm range. Electrical
measurements establish that TaSe3/h-BN nanowire heterostructures have a
breakdown current density exceeding 10 MA/cm2 - an order-of-magnitude higher
than that in copper. Some devices exhibited an intriguing step-like breakdown,
which can be explained by the atomic thread bundle structure of the nanowires.
The quasi-1D single crystal nature of TaSe3 results in low surface roughness
and the absence of grain boundaries; these features potentially can enable the
downscaling of these wires to lateral dimensions in the few-nm range. These
results suggest that quasi-1D van der Waals metals have potential for
applications in the ultimately downscaled local interconnects.


title: Polariton excitation rates from time dependent dielectrics

abstract:
  In recent years, a rigorous quantum mechanical model for the interaction
between light and macroscopic dispersive, lossy dielectrics has emerged
-macroscopic QED- allowing the application of the usual methods of quantum
field theory. Here, we apply time dependent perturbation theory to a general
class of problems involving time dependent lossy, dispersive dielectrics. The
model is used to derive polariton excitation rates in three illustrative cases,
including that of a travelling Gaussian perturbation to the susceptibility of
an otherwise infinite homogeneous dielectric, motivated by recent experiments
on analogue Hawking radiation. We find that the excitation rate is increased
when the wave--vector and frequency of each polariton in the pair either
satisfies (or nearly satisfies) the dispersion relation for electromagnetic
waves, or is close to a material resonance.


title: Smooth Causal Patches for AdS Black Holes

abstract:
  We review the paradox of low energy excitations about an AdS black hole. An
appropriately chosen unitary operator in the boundary theory can create a
locally strong excitation near the black hole horizon, whose global energy is
small as a result of the gravitational redshift. The paradox is that this seems
to violate a general rule of statistical mechanics, which states that an
operator with energy parametrically smaller than $k T$ cannot create a
significant excitation in a thermal system. When we carefully examine the
position dependence of the boundary unitary operator that produces the
excitation and the bulk observable necessary to detect the anomalously large
effect, we find that they do not both fit in a single causal patch. This
follows from a remarkable property of position space AdS correlators that we
establish explicitly, and resolves the paradox in a generic state of the
system, since no combination of observers can both create the excitation and
observe its effect. As a special case of our analysis, we show how this
resolves the "Born rule" paradox of arXiv:1506.01337 and we verify our solution
using an independent calculation. We then consider boundary states that are
finely tuned to display a spontaneous excitation outside the causal patch of
the infalling observer, and we propose a version of causal patch
complementarity in AdS/CFT that resolves the paradox for such states as well.


title: Minimal models for topological Weyl semimetals

abstract:
  Topological Weyl semimetals (TWS) can be classified as type-I TWS, in which
the density of states vanishes at the Weyl nodes, and type-II TWS where an
electron and a hole pocket meet with finite density of states at the nodal
energy. The dispersions of type-II Weyl nodes are tilted and break Lorentz
invariance, allowing for physical properties distinct from those in a type-I
TWS. We present minimal lattice models for both time-reversal-breaking and
inversion-breaking type-II Weyl semimetals, and investigate their bulk
properties and topological surface states. These lattice models capture the
extended Fermi pockets and the connectivities of Fermi arcs. In addition to the
Fermi arcs, which are topologically protected, we identify surface "track
states" that arise out of the topological Fermi arc states at the transition
from type-I to type-II with multiple Weyl nodes, and persist in the type-II
TWS.


title:
Modified Korteweg-de Vries solitons at supercritical densities in
  two-electron temperature plasmas

abstract:
  The supercritical composition of a plasma model with cold positive ions in
the presence of a two-temperature electron population is investigated,
initially by a reductive perturbation approach, under the combined requirements
that there be neither quadratic nor cubic nonlinearities in the evolution
equation. This leads to a unique choice for the set of compositional parameters
and a modified Korteweg-de Vries equation (mKdV) with a quartic nonlinear term.
The conclusions about its one-soliton solution and integrability will also be
valid for more complicated plasma compositions. Only three polynomial
conservation laws can be obtained. The mKdV equation with quartic nonlinearity
is not completely integrable, thus precluding the existence of multi-soliton
solutions. Next, the full Sagdeev pseudopotential method has been applied and
this allows for a detailed comparison with the reductive perturbation results.
This comparison shows that the mKdV solitons have slightly larger amplitudes
and widths than those obtained from the more complete Sagdeev solution and that
only slightly superacoustic mKdV solitons have acceptable amplitudes and
widths, in the light of the full solutions.


title:
Patterns on data described by vague limits, vague colimits and vague
  commutativity

abstract:
  The development of machine learning in particular and artificial intelligent
in general has been strongly conditioned by the lack of an appropriated
framework to specify and integrate learning processes, data transformation
processes and data models. In this work we extend traditional algebraic
specification methods to this type of framework. Limits and colimits of
diagrams are universal constructions fundamental in different mathematical
domains importance in semantic modeling. The aim of our work is to study the
possibility of extending these algebraic frameworks to the specification of
vague structures and to the description of vague patterns on data.


title: Symbolic Knowledge Extraction using {\L}ukasiewicz Logics

abstract:
  This work describes a methodology that combines logic-based systems and
connectionist systems. Our approach uses finite truth-valued {\L}ukasiewicz
logic, wherein every connective can be defined by a neuron in an artificial
network. This allowed the injection of first-order formulas into a network
architecture, and also simplified symbolic rule extraction. For that we trained
a neural networks using the Levenderg-Marquardt algorithm, where we restricted
the knowledge dissemination in the network structure. This procedure reduces
neural network plasticity without drastically damaging the learning
performance, thus making the descriptive power of produced neural networks
similar to the descriptive power of {\L}ukasiewicz logic language and
simplifying the translation between symbolic and connectionist structures. We
used this method for reverse engineering truth table and in extraction of
formulas from real data sets.


title: Edge anisotropy and the geometric perspective on flow networks

abstract:
  Spatial networks have recently attracted great interest in various fields of
research. While the traditional network-theoretic viewpoint is commonly
restricted to their topological characteristics (often disregarding existing
spatial constraints), this work takes a geometric perspective, which considers
vertices and edges as objects in a metric space and quantifies the
corresponding spatial distribution and alignment. For this purpose, we
introduce the concept of edge anisotropy and define a class of measures
characterizing the spatial directedness of connections. Specifically, we
demonstrate that the local anisotropy of edges incident to a given vertex
provides useful information about the local geometry of geophysical flows based
on networks constructed from spatio-temporal data, which is complementary to
topological characteristics of the same flow networks. Taken both structural
and geometric viewpoints together can thus assist the identification of
underlying flow structures from observations of scalar variables.


title: Comment on "Hybridized Tetraquarks"

abstract:
  In this comment, I illustrate that the formula $\Gamma=A\sqrt{\delta}$
suggested in arXiv:1603.07667 comes from a kinematical factor, and has no
relation to the existence or non-existence of the $X(5568)$.


title: Track segment finding with CGEM-IT and matching to tracks in ODC

abstract:
  The relative differences in coordinates of
Cylindrical-Gas-Electron-Multiplier-Detector-based Inner Tracker (CGEM-IT)
clusters are studied to search for track segments in CGEM-IT. With the full
simulation of single muon track samples, clear patterns are found and
parameterized for the correct cluster combinations. The cluster combinations
satisfying the patterns are selected as track segment candidates in CGEM-IT
with an efficiency higher than 99%. The parameters of the track segments are
obtained by a helix fitting. Some chi-squared quantities, evaluating the
differences in track parameters between the track segments in CGEM-IT and the
tracks found in Outer-Drift-Chamber (ODC), are calculated and used to match
them. Proper chi-squared requirements are determined as a function of
transverse momentum and the matching efficiency is found reasonable.


title:
A Factor of Four Increase in Attenuation Length of Dipped Lightguides
  for Liquid Argon TPCs Through Improved Coating

abstract:
  This paper describes new techniques for producing lightguides for detection
of scintillation light in liquid argon time projection chambers. These can be
used in future neutrino experiments such as SBND and DUNE. These new results
build on a dipped-coating technique that was previously reported and is
reviewed here. The improvements to the approach indicate a factor of four
improvement in attenuation length of the lightguides compared to past studies.
The measured attenuation lengths, which are >2 m, are consistent with the bulk
attenuation length of the material. Schematics for a mechanical dipping system
are provided in this paper. This system is shown to result in coatings with <
10% variations


title: Carbon to oxygen ratios in extrasolar planetesimals

abstract:
  Observations of small extrasolar planets with a wide range of densities imply
a variety of planetary compositions and structures. Currently, the only
technique to measure the bulk composition of extrasolar planetary systems is
the analysis of planetary debris accreting onto white dwarfs, analogous to
abundance studies of meteorites. We present measurements of the carbon and
oxygen abundances in the debris of planetesimals at ten white dwarfs observed
with the Hubble Space Telescope, along with C/O ratios of debris in six systems
with previously reported abundances. We find no evidence for carbon-rich
planetesimals, with C/O<0.8 by number in all 16 systems. Our results place an
upper limit on the occurrence of carbon-rich systems at <17 percent with a 2
sigma confidence level. The range of C/O of the planetesimals is consistent
with that found in the Solar System, and appears to follow a bimodal
distribution: a group similar to the CI chondrites, with log(<C/O>)=-0.92, and
oxygen-rich objects with C/O less than or equal to that of the bulk Earth. The
latter group may have a higher mass fraction of water than the Earth,
increasing their relative oxygen abundance.


title: The Gauge-Higgs Legacy of the LHC Run I

abstract:
  The effective Lagrangian expansion provides a framework to study effects of
new physics at the electroweak scale. To make full use of LHC data in
constraining higher-dimensional operators we need to include both the Higgs and
the electroweak gauge sector in our study. We first present an analysis of the
relevant di-boson production LHC results to update constraints on triple gauge
boson couplings. Our bounds are several times stronger than those obtained from
LEP data. Next, we show how in combination with Higgs measurements the triple
gauge vertices lead to a significant improvement in the entire set of
operators, including operators describing Higgs couplings.


title:
Thermal SZ fluctuations in the ICM: probing turbulence and
  thermodynamics in Coma cluster with ${\it Planck}$

abstract:
  We report the detection of thermal Sunyaev-Zeldovich effect (SZ) fluctuations
in the intracluster medium (ICM) of Coma cluster observed with ${\it Planck}$.
The SZ data links the maximum observable X-ray scale to the large Mpc scale,
extending our knowledge of the power spectrum of ICM fluctuations. Deprojecting
the 2-d SZ perturbations into 3-d pressure fluctuations, we find an amplitude
spectrum which peaks at $\delta P/P = 33\pm 12\%$ and $74\pm19\%$ in the $15'$
and $40'$ radius region, respectively. We perform tests to ensure fluctuations
are intrinsic to the cluster and not due to noise contamination. By using
high-resolution hydrodynamical models, we improve the ICM turbulence
constraints in Coma, finding 3-d Mach number ${\rm Ma_{3d}}= 0.8\pm0.3$ (15'
region), increasing to supersonic values at larger radii (40'), and an
injection scale $L_{\rm inj}\approx 500$ kpc. Such properties are consistent
with driving due to mergers, in particular tied to internal galaxy groups. The
large pressure fluctuations show that Coma is in adiabatic mode (mediated by
sound waves), rather than isobaric mode (mediated by buoyancy waves). As
predicted by turbulence models, the distribution of SZ fluctuations is
log-normal with mild non-Gaussianities (heavy tails). The substantial
non-thermal pressure support implies hydrostatic mass bias $b_M=-15\%$ to
$-45\%$ from the core to the outskirt region, respectively. While total SZ
power probes the thermal energy content, the SZ fluctuations constrain the
non-thermal deviations important for precision cosmology. The proposed, novel
approach can be exploited by multifrequency observations using ground based
interferometers and future space CMB missions.

categories: astro-ph.CO astro-ph.GA astro-ph.HE physics.flu-dyn physics.plasm-ph


title:
The Occurrence of Additional Giant Planets Inside the Water-Ice Line in
  Systems with Hot Jupiters: Evidence Against High-Eccentricity Migration

abstract:
  The origin of Jupiter-mass planets with orbital periods of only a few days is
still uncertain. It is widely believed that these planets formed near the
water-ice line of the protoplanetary disk, and subsequently migrated into much
smaller orbits. Most of the proposed migration mechanisms can be classified
either as disk-driven migration, or as excitation of a very high eccentricity
followed by tidal circularization. In the latter scenario, the giant planet
that is destined to become a hot Jupiter spends billions of years on a
highly-eccentric orbit, with apastron near the water-ice line. Eventually,
tidal dissipation at periastron shrinks and circularizes the orbit. If this is
correct, then it should be especially rare for hot Jupiters to be accompanied
by another giant planet interior to the water-ice line. Using the current
sample of giant planets discovered with the Doppler technique, we find that hot
Jupiters with P_orb < 10 days are no more or less likely to have exterior
Jupiter-mass companions than longer-period giant planets with P_orb >= 10 days.
This result holds for exterior companions both inside and outside of the
approximate location of the water-ice line. These results are difficult to
reconcile with the high-eccentricity migration scenario for hot Jupiter
formation.


title: Searching for Additional Higgs Bosons via Higgs Cascades

abstract:
  The discovery of a 125 GeV Higgs boson at the Large Hadron Collider strongly
motivates direct searches for additional Higgs bosons. In a type I two Higgs
doublet model there is a large region of parameter space at $\tan\beta > 5$
that is currently unconstrained experimentally. We show that the process $gg
\to H \to A Z \to ZZh$ can probe this region, and can be the discovery mode for
an extended Higgs sector at the LHC. We analyze 9 promising decay modes for the
$ZZh$ state, and we find that the most sensitive final states are
$\ell\ell\ell\ell bb$, $\ell\ell jjbb$, $\ell\ell\nu\nu\gamma\gamma$ and
$\ell\ell\ell\ell +{}$missing energy.


title:
Characterising Strong Lensing Galaxy Clusters using the Millennium-XXL
  and MOKA simulations

abstract:
  In this paper we investigate the strong lensing statistics in galaxy
clusters. We extract dark matter haloes from the Millennium-XXL simulation,
compute their Einstein radius distribution, and find a very good agreement with
Monte Carlo predictions produced with the MOKA code. The distribution of the
Einstein radii is well described by a log-normal distribution, with a
considerable fraction of the largest systems boosted by different projection
effects. We discuss the importance of substructures and triaxiality in shaping
the size of the critical lines for cluster size haloes. We then model and
interpret the different deviations, accounting for the presence of a Bright
Central Galaxy (BCG) and two different stellar mass density profiles. We
present scaling relations between weak lensing quantities and the size of the
Einstein radii. Finally we discuss how sensible is the distribution of the
Einstein radii on the cosmological parameters {\Omega}_M-{\sigma}_8 finding
that cosmologies with higher {\Omega}_M and {\sigma}_8 possess a large sample
of strong lensing clusters. The Einstein radius distribution may help
distinguish Planck13 and WMAP7 cosmology at 3{\sigma}.


title: A Stereoscopic Look into the Bulk

abstract:
  We present the foundation for a holographic dictionary with depth perception.
The dictionary consists of natural CFT operators whose duals are simple,
diffeomorphism-invariant bulk operators. The CFT operators of interest are the
"OPE blocks," contributions to the OPE from a single conformal family. In
holographic theories, we show that the OPE blocks are dual at leading order in
1/N to integrals of effective bulk fields along geodesics or homogeneous
minimal surfaces in anti-de Sitter space. One widely studied example of an OPE
block is the modular Hamiltonian, which is dual to the fluctuation in the area
of a minimal surface. Thus, our operators pave the way for generalizing the
Ryu-Takayanagi relation to other bulk fields.
  Although the OPE blocks are non-local operators in the CFT, they admit a
simple geometric description as fields in kinematic space--the space of pairs
of CFT points. We develop the tools for constructing local bulk operators in
terms of these non-local objects. The OPE blocks also allow for conceptually
clean and technically simple derivations of many results known in the
literature, including linearized Einstein's equations and the relation between
conformal blocks and geodesic Witten diagrams.


title:
Quantum Diagrammatic Theory of the Extrinsic Spin Hall Effect in
  Graphene

abstract:
  We present a rigorous microscopic theory of the extrinsic spin Hall effect in
disordered graphene based on a nonperturbative quantum diagrammatic treatment
incorporating skew scattering and anomalous---impurity
concentration-independent---quantum corrections on equal footing. The leading
skew scattering contribution to the spin Hall conductivity is shown to
quantitatively agree with Boltzmann transport theory over a wide range of
parameters. Our self-consistent approach---where all topologically equivalent
noncrossing diagrams are resummed---unveils that the skewness generated by
spin--orbit-active impurities deeply influences the anomalous component of the
spin Hall conductivity, even in the weak scattering regime. This seemingly
counterintuitive result is explained by the rich sublattice structure of
scattering potentials in graphene, for which traditional Gaussian disorder
approximations fail to capture the intricate correlations between skew
scattering and side jumps generated through diffusion. Finally, we assess the
role of quantum interference corrections by evaluating an important subclass of
crossing diagrams recently considered in the context of the anomalous Hall
effect, the $X$ and $\Psi$ diagrams [Ado et al., EPL 111, 37004 (2015)]. We
show that $\Psi$ diagrams---encoding quantum coherent skew scattering---display
a strong Fermi energy dependence, dominating the anomalous spin Hall component
away from the Dirac point. Our findings have direct implications for nonlocal
transport experiments in spin--orbit-coupled graphene systems.


title: Nodal-chain metals

abstract:
  The band theory of solids is arguably the most successful theory of condensed
matter physics, providing the description of the electronic energy levels in a
variety of materials. Electronic wavefunctions obtained from the band theory
allow for a topological characterization of the system and the electronic
spectrum may host robust, topologically protected fermionic quasiparticles.
Many of these quasiparticles are analogs of the elementary particles of the
Standard Model, but others do not have a counterpart in relativistic
high-energy theories. A full list of possible quasiparticles in solids is still
unknown, even in the non-interacting case. Here, we report on a new type of
fermionic excitation that appears in metals. This excitation forms a nodal
chain -- a chain of connected loops in momentum space -- along which conduction
and valence band touch. We prove that the nodal chain is topologically distinct
from any other excitation reported before. We discuss the symmetry requirements
for the appearance of this novel excitation and predict that it is realized in
an existing material IrF$_4$, as well as in other compounds of this material
class. Using IrF$_4$ as an example, we provide a detailed discussion of the
topological surface states associated with the nodal chain. Furthermore, we
argue that the presence of the novel quasiparticles results in anomalous
magnetotransport properties, distinct from those of the known materials.


title: How Lyman Alpha Emission Depends On Galaxy Stellar Mass

abstract:
  In this work, we show how the stellar mass (M) of galaxies affects the
3<z<4.6 Ly-alpha equivalent width (EW) distribution. To this end, we design a
sample of 629 galaxies in the M range 7.6 < logM/Msun < 10.6 from the
3D-HST/CANDELS survey. We perform spectroscopic observations of this sample
using the Michigan/Magellan Fiber System, allowing us to measure Ly-alpha
fluxes and use 3D-HST/CANDELS ancillary data. In order to study the Ly-alpha EW
distribution dependence on M, we split the whole sample in three stellar mass
bins. We find that, in all bins, the distribution is best represented by an
exponential profile of the form dN(M)/dEW= A(M)exp(-EW/W0(M))/W0(M). Through a
Bayesian analysis, we confirm that lower M galaxies have higher Ly-alpha EWs.
We also find that the fraction A of galaxies featuring emission and the
e-folding scale W0 of the distribution anti- correlate with M, recovering
expressions of the forms A(M)= -0.26(.13) logM/Msun+3.01(1.2) and W0(M)=
-15.6(3.5) logM/Msun +166(34). These results are crucial for proper
interpretation of Ly-alpha emission trends reported in the literature that may
be affected by strong M selection biases.


title: Conversational flow in Oxford-style debates

abstract:
  Public debates are a common platform for presenting and juxtaposing diverging
views on important issues. In this work we propose a methodology for tracking
how ideas flow between participants throughout a debate. We use this approach
in a case study of Oxford-style debates---a competitive format where the winner
is determined by audience votes---and show how the outcome of a debate depends
on aspects of conversational flow. In particular, we find that winners tend to
make better use of a debate's interactive component than losers, by actively
pursuing their opponents' points rather than promoting their own ideas over the
course of the conversation.

categories: cs.CL cs.AI cs.SI physics.soc-ph stat.ML


title: A broad class of shellable lattices

abstract:
  We introduce a new class of lattices, the modernistic lattices, and their
duals, the comodernistic lattices. We show that every modernistic or
comodernistic lattice has shellable order complex. We go on to exhibit a large
number of examples of (co)modernistic lattices. We show comodernism for two
main families of lattices that were not previously known to be shellable: the
order congruence lattices of finite posets, and a weighted generalization of
the k-equal partition lattices.
  We also exhibit many examples of (co)modernistic lattices that were already
known to be shellable. To start with, the definition of modernistic is a common
weakening of the definitions of semimodular and supersolvable. We thus obtain a
unified proof that lattice in these classes are shellable.
  Subgroup lattices of solvable groups form another family of comodernistic
lattices that were already proved to be shellable. We show not only that
subgroup lattices of solvable groups are comodernistic, but that solvability of
a group is equivalent to the comodernistic property on its subgroup lattice.
Indeed, the definition of comodernistic exactly requires on every interval a
lattice-theoretic analogue of the composition series in a solvable group. Thus,
the relation between comodernistic lattices and solvable groups resembles, in
several respects, that between supersolvable lattices and supersolvable groups.


title:
The Appearance of Spicules in High Resolution Observations of Ca II H
  and H-alpha

abstract:
  Solar spicules are chromospheric fibrils that appear everywhere on the Sun,
yet their origin is not understood. Using high resolution observations of
spicules obtained with the Swedish 1-m Solar Telescope, we aim to understand
how spicules appear in filtergrams and Dopplergrams, how they compare in Ca II
H and H-alpha, and what can make them appear and disappear. We find
thatspicules display a rich and detailed spatial structure, and show a
distribution of transverse velocities that when aligned with the line of sight
can make them appear at different H-alpha wing positions. They become more
abundant at positions closer to the line core, reflecting a distribution of
Doppler shifts and widths. In H-alpha width maps they stand out as bright
features both on disk and off limb, reflecting their large Doppler motions and
possibly higher temperatures than in the typical H-alpha formation region.
Spicule lifetimes measured from narrowband images at only a few positions will
be an underestimate because Doppler shifts can make them disappear prematurely
from such images; for such cases, width maps are a more robust tool. In H-alpha
and Ca II H filtergrams, off limb spicules essentially have the same
properties, appearance, and evolution. We find that the sudden appearance of
spicules can be explained by Doppler shifts from their transverse motions, and
does not require other convoluted explanations.


title: A Hamiltonian approach to Thermodynamics

abstract:
  In the present work we develop a strictly Hamiltonian approach to
Thermodynamics. A thermodynamic description based on symplectic geometry is
introduced, where all thermodynamic processes can be described within the
framework of Analytic Mechanics. Our proposal is constructed on top of a usual
symplectic manifold, where phase space is even dimensional and one has
well-defined Poisson brackets. The main idea is the introduction of an extended
phase space where thermodynamic equations of state are realized as constraints.
We are then able to apply the canonical transformation toolkit to thermodynamic
problems. Throughout this development, Dirac's theory of constrained systems is
extensively used. To illustrate the formalism, we consider paradigmatic
examples, namely, the ideal, van der Waals and Clausius gases.

categories: hep-th cond-mat.stat-mech math-ph math.MP


title: Deriving Grover's lower bound from simple physical principles

abstract:
  Grover's algorithm constitutes the optimal quantum solution to the search
problem and provides a quadratic speed-up over all possible classical search
algorithms. Quantum interference between computational paths has been posited
as a key resource behind this computational speed-up. However there is a limit
to this interference, at most pairs of paths can ever interact in a fundamental
way. Could more interference imply more computational power? Sorkin has defined
a hierarchy of possible interference behaviours---currently under experimental
investigation---where classical theory is at the first level of the hierarchy
and quantum theory belongs to the second. Informally, the order in the
hierarchy corresponds to the number of paths that have an irreducible
interaction in a multi-slit experiment. In this work, we consider how Grover's
speed-up depends on the order of interference in a theory. Surprisingly, we
show that the quadratic lower bound holds regardless of the order of
interference. Thus, at least from the point of view of the search problem,
post-quantum interference does not imply a computational speed-up over quantum
theory.


title: Radial profiles of the Phoebe ring, a vast debris disk around Saturn

abstract:
  We present observations at optical wavelengths with the Cassini Spacecraft's
Imaging Science System of the Phoebe ring, a vast debris disk around Saturn
that seems to be collisionally generated by its irregular satellites. The
analysis reveals a radial profile from 80-260 Saturn radii ($R_S$) that changes
behavior interior to $\approx 110 R_S$, which we attribute to either the moon
Iapetus sweeping up small particles, or to orbital instabilities that cause the
ring to flare up vertically. Our study yields an integrated I/F at 0.635 $\mu$m
along Saturn's shadow in the Phoebe ring's midplane from 80-250 $R_S$ of
$2.7^{+0.9}_{-0.3} \times 10^{-9}$. We develop an analytical model for the
size-dependent secular dynamics of retrograde Phoebe ring grains, and compare
this model to the observations. This analysis implies that 1) the "Phoebe" ring
is partially sourced by debris from irregular satellites beyond Phoebe's orbit
and 2) the scattered light signal is dominated by small grains ($\lesssim
20\mu$m in size). If we assume that the Phoebe ring is generated through
steady-state micrometeoroid bombardment, this implies a power-law size
distribution with index $> 4$, which is unusually steep among solar system
rings. This suggests either a steep size distribution of ejecta when material
is initially released, or a subsequent process that preferentially breaks up
large grains.


title: Affleck-Dine Baryogenesis in Type IIB String Models

abstract:
  We present a viable string embedding of Affleck-Dine baryogenesis in type IIB
sequestered models where the late-time decay of the lightest modulus reheats
the universe to relatively low temperatures. We show that if inflation is
driven by a blow-up Kaehler modulus, the Affleck-Dine field can become
tachyonic during inflation if the Kaehler metric for matter fields has an
appropriate inflaton-dependent contribution. We find that the Affleck-Dine
mechanism can generate the observed baryon asymmetry for natural values of the
underlying parameters which lead also to successful inflation and low-energy
gaugino masses in a split supersymmetry scenario. The reheating temperature
from the lightest modulus decay is high enough to allow thermal Higgsino-like
dark matter.


title: Planet Scattering Around Binaries: Ejections, Not Collisions

abstract:
  Transiting circumbinary planets discovered by Kepler provide unique insight
into binary star and planet formation. Several features of this new found
population, for example the apparent pile-up of planets near the innermost
stable orbit, may distinguish between formation theories. In this work, we
determine how planet-planet scattering shapes planetary systems around binaries
as compared to single stars. In particular, we look for signatures that arise
due to differences in dynamical evolution in binary systems. We carry out a
parameter study of N-body scattering simulations for four distinct planet
populations around both binary and single stars. While binarity has little
influence on the final system multiplicity or orbital distribution, the
presence of a binary dramatically effects the means by which planets are lost
from the system. Most circumbinary planets are lost due to ejections rather
than planet-planet or planet-star collisions. The most massive planet in the
system tends to control the evolution. Systems similar to the only observed
multi-planet circumbinary system, Kepler-47, can arise from much more tightly
packed, unstable systems. Only extreme initial conditions introduce differences
in the final planet populations. Thus, we suggest that any intrinsic
differences in the populations are imprinted by formation.


title:
Large $N$ matrix models for 3d ${\cal N}=2$ theories: twisted index,
  free energy and black holes

abstract:
  We provide general formulae for the topologically twisted index of a general
three-dimensional ${\cal N}\geq 2$ gauge theory with an M-theory or massive
type IIA dual in the large $N$ limit. The index is defined as the
supersymmetric path integral of the theory on $S^2\times S^1$ in the presence
of background magnetic fluxes for the R- and global symmetries and it is
conjectured to reproduce the entropy of magnetically charged static BPS AdS$_4$
black holes. For a class of theories with an M-theory dual, we show that the
logarithm of the index scales indeed as $N^{3/2}$ (and $N^{5/3}$ in the massive
type IIA case). We find an intriguing relation with the (apparently unrelated)
large $N$ limit of the partition function on $S^3$. We also provide a universal
formula for extracting the index from the large $N$ partition function on $S^3$
and its derivatives and point out its analogy with the attractor mechanism for
AdS black holes.


title: On the symmetries of the 12C nucleus

abstract:
  The consequences of some symmetries of the three-alpha system are discussed.
In particular, the recent description of the low-energy spectrum of the 12C
nucleus in terms of the Algebraic Cluster Model (ACM) is compared to that of
the Semimicroscopic Algebraic Cluster Model (SACM). The previous one applies
interactions of a D3h geometric symmetry [1], while the latter one has a U(3)
multichannel dynamical symmetry, that connects the shell and cluster pictures.
The available data is in line with both descriptions.


title: Analog Quantum Simulation of (1+1)D Lattice QED with Trapped Ions

abstract:
  The prospect of quantum simulating lattice gauge theories opens exciting
possibilities for understanding fundamental forms of matter. Here, we show that
trapped ions represent a promising platform in this context when simultaneously
exploiting internal pseudo-spins and external phonon vibrations. We illustrate
our ideas with two complementary proposals for simulating lattice-regularized
quantum electrodynamics (QED) in (1+1) space-time dimensions. The first scheme
replaces the gauge fields by local vibrations with a high occupation number. By
numerical finite-size scaling, we demonstrate that this model recovers Wilson's
lattice gauge theory in a controlled way. Its implementation can be scaled up
to tens of ions in an array of micro-traps. The second scheme represents the
gauge fields by spins 1/2, and thus simulates a quantum link model. As we show,
this allows the fermionic matter to be replaced by bosonic degrees of freedom,
permitting small-scale implementations in a linear Paul trap. Both schemes work
on energy scales significantly larger than typical decoherence rates in
experiments, thus enabling the investigation of phenomena such as string
breaking, Coleman's quantum phase transition, and false-vacuum decay. The
underlying ideas of the proposed analog simulation schemes may also be adapted
to other platforms, such as superconducting qubits.


title:
Covalent functionalization by cycloaddition reactions of pristine,
  defect-free graphene

abstract:
  Based on a low temperature scanning tunneling microscopy study, we present a
direct visualization of a cycloaddition reaction performed for some specific
fluorinated maleimide molecules deposited on graphene. These studies showed
that the cycloaddition reactions can be carried out on the basal plane of
graphene, even when there are no pre-existing defects. In the course of
covalently grafting the molecules to graphene, the sp2 conjugation of carbon
atoms was broken and local sp3 bonds were created. The grafted molecules
perturbed the graphene lattice, generating a standing-wave pattern with an
anisotropy which was attributed to a (1,2) cycloaddition, as revealed by
T-matrix approximation calculations. DFT calculations showed that while both
(1,4) and (1,2) cycloaddition were possible on free standing graphene, only the
(1,2) cycloaddition could be obtained for graphene on SiC(0001). Globally
averaging spectroscopic techniques, XPS and ARPES, were used to determine the
modification in the elemental composition of the samples induced by the
reaction, indicating an opening of an electronic gap in graphene.


title: A planar four-loop form factor and cusp anomalous dimension in QCD

abstract:
  We compute the fermionic contribution to the photon-quark form factor to
four-loop order in QCD in the planar limit in analytic form. From the divergent
part of the latter the cusp and collinear anomalous dimensions are extracted.
Results are also presented for the finite contribution. We briefly describe our
method to compute all planar master integrals at four-loop order.


title: Occurrence of exact $R^2$ inflation in non-local UV-complete gravity

abstract:
  The $R+R^2$, shortly named "$R^2$" ("Starobinsky") inflationary model,
represents a fully consistent example of a one-parameter inflationary scenario.
This model has a "graceful exit" from inflation and provides a mechanism for
subsequent creation and final thermalization of the standard matter. Moreover,
it produces a very good fit of the observed spectrum of primordial
perturbations. In the present paper we show explicitly that the $R^2$
inflationary spacetime is an exact solution of a range of weakly non-local
(quasi-polynomial) gravitational theories, which provide an ultraviolet
completion of the $R^2$ theory. These theories are ghost-free,
super-renormalizable or finite at quantum level, and perturbatively unitary.
Their spectrum consists of the graviton and the scalaron that is responsible
for driving the inflation. Notably, any further extension of the spectrum leads
to propagating ghost degrees of freedom. We are aimed at presenting a detailed
construction of such theories in the so called Weyl basis. Further, we give a
special account to the cosmological implications of this theory by considering
perturbations during inflation. The highlight of the non-local model is the
prediction of a modified, in comparison to a local $R^2$ model, value for the
ratio of tensor and scalar power spectra $r$, depending on the parameters of
the theory. The relevant parameters are under control to be successfully
confronted with existing observational data. Furthermore, the modified $r$ can
surely meet future observational constraints.


title:
The Secret Lives of Cepheids: Evolution, Mass Loss, and Ultraviolet
  Emission of the Long-Period Classical Cepheid $l$ Carinae

abstract:
  The classical Cepheid $l$ Carinae is an essential calibrator of the Cepheid
Leavitt Law as a rare long-period Galactic Cepheid. Understanding the
properties of this star will also constrain the physics and evolution of
massive ($M \ge 8$ $M_\odot$) Cepheids. The challenge, however, is precisely
measuring the star's pulsation period and its rate of period change. The former
is important for calibrating the Leavitt Law and the latter for stellar
evolution modeling. In this work, we combine previous time-series observations
spanning more than a century with new observations to remeasure the pulsation
period and compute the rate of period change. We compare our new rate of period
change with stellar evolution models to measure the properties of $l$ Car, but
find models and observations are, at best, marginally consistent. The results
imply that $l$ Car does not have significantly enhanced mass-loss rates like
that measured for $\delta$ Cephei. We find that the mass of $l$ Car is about 8
- 10 $M_\odot$. We present Hubble Space Telescope COS observations that also
differ from measurements for $\delta$ Cep, and $\beta$ Dor. These measurements
further add to the challenge of understanding the physics of Cepheids, but do
hint at the possible relation between enhanced mass loss and ultraviolet
emission, perhaps both due to the strength of shocks propagating in the
atmospheres of Cepheids.


title:
Large Bragg Reflection from One-Dimensional Chains of Trapped Atoms Near
  a Nanoscale Waveguide

abstract:
  We report experimental observations of large Bragg reflection from arrays of
cold atoms trapped near a one-dimensional nanoscale waveguide. By using an
optical lattice in the evanescent field surrounding a nanofiber with a period
nearly commensurate with the resonant wavelength, we observe a reflectance of
up to 75% for the guided mode. Each atom behaves as a partially-reflecting
mirror and an ordered chain of about 2000 atoms is sufficient to realize an
efficient Bragg mirror. Measurements of the reflection spectra as a function of
the lattice period and the probe polarization are reported. The latter shows
the effect of the chiral character of nanoscale waveguides on this reflection.
The ability to control photon transport in 1D waveguides coupled to spin
systems would enable novel quantum network capabilities and the study of
many-body effects emerging from long-range interactions.


title: Video Analysis for Body-worn Cameras in Law Enforcement

abstract:
  The social conventions and expectations around the appropriate use of imaging
and video has been transformed by the availability of video cameras in our
pockets. The impact on law enforcement can easily be seen by watching the
nightly news; more and more arrests, interventions, or even routine stops are
being caught on cell phones or surveillance video, with both positive and
negative consequences. This proliferation of the use of video has led law
enforcement to look at the potential benefits of incorporating video capture
systematically in their day to day operations. At the same time, recognition of
the inevitability of widespread use of video for police operations has caused a
rush to deploy all types of cameras, including body worn cameras. However, the
vast majority of police agencies have limited experience in utilizing video to
its full advantage, and thus do not have the capability to fully realize the
value of expanding their video capabilities. In this white paper, we highlight
some of the technology needs and challenges of body-worn cameras, and we relate
these needs to the relevant state of the art in computer vision and multimedia
research. We conclude with a set of recommendations.


title: Earth-mass haloes and the emergence of NFW density profiles

abstract:
  We simulate neutralino dark matter ($\chi$DM) haloes from their initial
collapse, at $\sim$ earth mass, up to a few percent solar. Our results confirm
that the density profiles of the first haloes are described by a $\sim
r^{-1.5}$ power-law. As haloes grow in mass, their density profiles evolve
significantly. In the central regions, they become shallower and reach on
average $\sim r^{-1}$, the asymptotic form of an NFW profile. Using
non-cosmological controlled simulations, we observe that temporal variations in
the gravitational potential caused by major mergers lead to a shallowing of the
inner profile. This transformation is more significant for shallower initial
profiles and for a higher number of merging systems. Depending on the merger
details, the resulting profiles can be shallower or steeper than NFW in their
inner regions. Interestingly, mergers have a much weaker effect when the
profile is given by a broken power-law with an inner slope of $-1$ (such as NFW
or Hernquist profiles). This offers an explanation for the emergence of
NFW-like profiles: after their initial collapse, $r^{-1.5}$ $\chi$DM haloes
suffer copious major mergers, which progressively shallows the profile. Once an
NFW-like profile is established, subsequent merging do not change the profile
anymore. This suggests that halo profiles are not universal but rather a
combination of (1) the physics of the formation of the microhaloes and (2)
their early merger history -- both set by the properties of the dark matter
particle -- as well as (3) the resilience of NFW-like profiles to
perturbations.


title: Efficient Index Maintenance Under Dynamic Genome Modification

abstract:
  Efficient text indexing data structures have enabled large-scale genomic
sequence analysis and are used to help solve problems ranging from assembly to
read mapping. However, these data structures typically assume that the
underlying reference text is static and will not change over the course of the
queries being made. Some progress has been made in exploring how certain text
indices, like the suffix array, may be updated, rather than rebuilt from
scratch, when the underlying reference changes. Yet, these update operations
can be complex in practice, difficult to implement, and give fairly pessimistic
worst-case bounds. We present a novel data structure, SkipPatch, for
maintaining a k-mer-based index over a dynamically changing genome. SkipPatch
pairs a hash-based k-mer index with an indexable skip list that is used to
efficiently maintain the set of edits that have been applied to the original
genome. SkipPatch is practically fast, significantly outperforming the dynamic
extended suffix array in terms of update and query speed.


title:
An Update on Local Universality Limits for Correlation Functions
  Generated by Unitary Ensembles

abstract:
  We survey the current status of universality limits for $m$-point correlation
functions in the bulk and at the edge for unitary ensembles, primarily when the
limiting kernels are Airy, Bessel, or Sine kernels. In particular, we consider
underlying measures on compact intervals, and fixed and varying exponential
weights, as well as universality limits for a variety of orthogonal systems.
The scope of the survey is quite narrow: we do not consider $\beta$ ensembles
for $\beta \neq 2$, nor general Hermitian matrices with independent entries,
let alone more general settings. We include some open problems.


title: Protoplanetary Disks in the Orion OMC1 Region Imaged with ALMA

abstract:
  We present ALMA observations of the Orion Nebula that cover the OMC1 outflow
region. Our focus in this paper is on compact emission from protoplanetary
disks. We mosaicked a field containing $\sim 600$ near-IR-identified young
stars, around which we can search for sub-mm emission tracing dusty disks.
Approximately 100 sources are known proplyds identified with HST. We detect
continuum emission at 1 mm wavelengths towards $\sim 20\%$ of the proplyd
sample, and $\sim 8\%$ of the larger sample of near-IR objects. The noise in
our maps allows 4$\sigma$ detection of objects brighter than $\sim 1.5$ mJy,
corresponding to protoplanetary disk masses larger than 1.5 M$_{\rm J}$ (using
standard assumptions about dust opacities and gas-to-dust ratios). None of
these disks are detected in contemporaneous CO(2-1) or C$^{18}$O(2-1)
observations, suggesting that the gas-to-dust ratios may be substantially
smaller than the canonical value of 100. Furthermore, since dust grains may
already be sequestered in large bodies in ONC disks, the inferred masses of
disk solids may be underestimated. Our results suggest that the distribution of
disk masses in this region is compatible with the detection rate of massive
planets around M dwarfs, which are the dominant stellar constituent in the ONC.


title:
The Impact of Stellar Rotation on the Detectability of Habitable Planets
  Around M Dwarfs

abstract:
  Stellar activity and rotation frustrate the detection of exoplanets through
the radial velocity technique. This effect is particularly of concern for M
dwarfs, which can remain magnetically active for billions of years. We compile
rotation periods for late-type stars and for the M dwarf planet-host sample in
order to investigate the rotation periods of older field stars across the main
sequence. We show that for stars with masses between 0.25 and 0.5 solar masses
(M4V to M1V), the stellar rotation period typical of field stars coincides with
the orbital periods of planets in the habitable zone. This will pose a
fundamental challenge to the discovery and characterization of potentially
habitable planets around early M dwarfs. Due to the longer rotation periods
reached by mid M dwarfs and the shorter orbital period at which the planetary
habitable zone is found, stars with masses between 0.1 and 0.25 solar masses
(M6V to M4V) offer better opportunities for the detection of habitable planets
via radial velocities.


title: Shallow Parsing Pipeline for Hindi-English Code-Mixed Social Media Text

abstract:
  In this study, the problem of shallow parsing of Hindi-English code-mixed
social media text (CSMT) has been addressed. We have annotated the data,
developed a language identifier, a normalizer, a part-of-speech tagger and a
shallow parser. To the best of our knowledge, we are the first to attempt
shallow parsing on CSMT. The pipeline developed has been made available to the
research community with the goal of enabling better text analysis of Hindi
English CSMT. The pipeline is accessible at http://bit.ly/csmt-parser-api .


title: Measures and slaloms

abstract:
  We examine measure-theoretic properties of spaces constructed using certain
technique of Todor\v{c}evi\'{c}. We show that the existence of strictly
positive measures on such spaces depends on combinatorial properties of certain
families of slaloms. As a corollary we get that if $\mathrm{add}(\mathcal{N}) =
\mathrm{non}(\mathcal{M})$ then there is a non-separable space which supports a
measure and which cannot be mapped continuously onto $[0,1]^{\omega_1}$. Also,
without any additional axioms we prove that there is a non-separable growth of
$\omega$ supporting a measure and that there is a compactification $L$ of
$\omega$ with growth of such properties and such that the natural copy of $c_0$
is complemented in $C(L)$. Finally, we discuss examples of spaces not
supporting measures but satisfying quite strong chain conditions. Our main tool
is a characterization due to Kamburelis of Boolean algebras supporting measures
in terms of their chain conditions in generic extensions by a measure algebra.


title: Torsion in the cohomology of torus orbifolds

abstract:
  We study torsion in the integral cohomology of a certain family of
$2n$-dimensional orbifolds $X$ with actions of the $n$-dimensional compact
torus. Compact simplicial toric varieties are in our family. For a prime number
$p$, we find a necessary condition for the integral cohomology of $X$ to have
no $p$-torsion. Then we prove that the necessary condition is sufficient in
some cases. We also give an example of $X$ which shows that the necessary
condition is not sufficient in general.


title: Experimental overview on quarkonium production

abstract:
  Quarkonium production in heavy-ion collisions is a well-known signature of
the formation of a plasma of quarks and gluons (QGP). After thirty years from
the first measurements at SPS energies, a large wealth of results is now
accessible from high-energy experiments at RHIC and LHC, and these new data are
contributing to sharpen the picture of the quarkonium behaviour in A-A
collisions. In this paper, an overview of the main results on both charmonium
and bottomonium production in p-A and A-A collisions is presented, focussing on
the most recent achievements from the RHIC and LHC experiments.


title: Optimal Binary Coding for $q^+$ -state Data Embedding

abstract:
  In steganography, we always hope to maximize the embedding payload subject to
an upper-bounded distortion. We need suitable distortion measurement to
evaluate the embedding impact. However, different distortion functions exposes
different levels of distortion evaluation, implying that we have different
optimization distributions by applying different distortion functions. In
applications, the embedding distortion is caused by a certain number of
embedding operations. Instead of a predefined distortion, we actually utilize a
number of modifications to embed as many message bits as possible as long as
the modifications are acceptable. This paper focuses on the design of optimal
binary codewords for data embedding with a limited number of modification
candidates. We have proved the optimality of the designed codewords, and
proposed the way to construct the optimal binary codewords. It is pointed out
that the optimal binary code is not unique, and an optimal code can be computed
within a low computational cost.


title:
North/South Hemispheric Periodicities in the >25 MeV Solar Proton Event
  Rate During the Rising and Peak Phases of Solar Cycle 24

abstract:
  We present evidence that $>25$ MeV solar proton events show a clustering in
time at intervals of $\approx$ six months that persisted during the rising and
peak phases of Solar Cycle 24. This phenomenon is most clearly demonstrated by
considering events originating in the northern or southern solar hemispheres
separately. We examine how these variations in the solar energetic particle
(SEP) event rate are related to other phenomena, such as hemispheric sunspot
numbers and areas, rates of coronal mass ejections, and the mean solar magnetic
field. Most obviously, the SEP event rate closely follows the sunspot number
and area in the same hemisphere. The $\approx$ six-month variations are
associated with features in many of the other parameters we examine, indicating
that they are just one signature of the episodic development of Cycle 24. They
may be related to the "$\approx$150~day" periodicities reported in various
solar and interplanetary phenomena during previous solar cycles. The clear
presence of $\approx$six-month periodicities in Cycle 24 that evolve
independently in each hemisphere conflicts with a scenario suggested by
McIntosh et al. (2015, Nature Com. 6, 6491) for the variational time scales of
solar magnetism.


title: Analytical Solution to the Fractional Polytropic Gas Spheres

abstract:
  Lane-Emden equation could be used to model stellar interiors, star clusters
and many configurations in astrophysics. Unfortunately, there is an exact
solution only for the polytropic index and . In the present paper, a series
solution for the fractional Lane-Emden equation is presented. The solution is
performed in the frame of modified Rienmann Liouville derivatives. The obtained
results recover the well-known series solutions when . Fractional model of n=3
has been calculated and mass-radius relation, density ratio, pressure ratio and
temperature ratio have been investigated. We found that the fractional star has
a smaller volume and mass than that of the integer star.


title: Radial Velocity Planet Detection Biases at the Stellar Rotational Period

abstract:
  Future generations of precise radial velocity (RV) surveys aim to achieve
sensitivity sufficient to detect Earth mass planets orbiting in their stars'
habitable zones. A major obstacle to this goal is astrophysical radial velocity
noise caused by active areas moving across the stellar limb as a star rotates.
In this paper, we quantify how stellar activity impacts exoplanet detection
with radial velocities as a function of orbital and stellar rotational periods.
We perform data-driven simulations of how stellar rotation affects planet
detectability and compile and present relations for the typical timescale and
amplitude of stellar radial velocity noise as a function of stellar mass. We
show that the characteristic timescales of quasi-periodic radial velocity
jitter from stellar rotational modulations coincides with the orbital period of
habitable zone exoplanets around early M-dwarfs. These coincident periods
underscore the importance of monitoring the targets of RV habitable zone planet
surveys through simultaneous photometric measurements for determining rotation
periods and activity signals, and mitigating activity signals using
spectroscopic indicators and/or RV measurements at different wavelengths.


title: Boundary Conditions at Infinity for Physical Theories

abstract:
  The Sommerfeld boundary conditions, imposed on hyperbolic differential
equations to obtain solutions in the form of outgoing waves, are formulated
here so as to make explicit the role of an appropriate null vector field. When
applied to the scalar and Maxwell equations, they lead to the asymptotic form
of the energy-momentum tensor representing radiation as a null, perfect dust.


title: Radiation and Boundary Conditions in the Theory of Gravitation

abstract:
  The Sommerfeld boundary conditions, applied to an asymptotically weak
gravitational field, are shown to imply that the 1/r part of the curvature
tensor of a space-time, satisfying the Einstein equations, is of type null in
the Petrov classification and that there is then a flux of energy carried away
by the outgoing gravitational wave.


title: Single crystal growth of CeTAl$_3$ (T = Cu, Ag, Au, Pd and Pt)

abstract:
  We report single crystal growth of the series of CeTAl$_3$ compounds with T =
Cu, Ag, Au, Pd and Pt by means of optical float zoning. High crystalline
quality was confirmed in a thorough characterization process. With the
exception of CeAgAl$_3$, all compounds crystallize in the non-centrosymmetric
tetragonal BaNiSn$_{3}$ structure (space group: I4mm, No. 107), whereas
CeAgAl$_3$ adopts the related orthorhombic PbSbO$_2$Cl structure (Cmcm, No.
63). An attempt to grow CeNiAl$_3$ resulted in the composition CeNi$_2$Al$_5$.
Low temperature resistivity measurements down to $\sim$0.1K did not reveal
evidence suggestive of magnetic order in CePtAl$_3$ and CePdAl$_3$. In
contrast, CeAuAl$_3$, CeCuAl$_3$ and CeAgAl$_3$ display signatures of magnetic
transitions at 1.3K, 2.1K and 3.2K, respectively. This is consistent with
previous reports of antiferromagnetic order in CeAuAl$_3$, and CeCuAl$_3$ as
well as ferromagnetism in CeAgAl$_3$, respectively.


title: Graph-based Collaborative Ranking

abstract:
  Data sparsity, that is a common problem in neighbor-based collaborative
filtering domain, usually complicates the process of item recommendation. This
problem is more serious in collaborative ranking domain, in which calculating
the users similarities and recommending items are based on ranking data. Some
graph-based approaches have been proposed to address the data sparsity problem,
but they suffer from two flaws. First, they fail to correctly model the users
priorities, and second, they cannot be used when the only available data is a
set of ranking instead of rating values. In this paper, we propose a novel
graph-based approach, called GRank, that is designed for collaborative ranking
domain. GRank can correctly model users priorities in a new tripartite graph
structure, and analyze it to directly infer a recommendation list. The
experimental results show a significant improvement in recommendation quality
compared to the state of the art graph-based recommendation algorithms and
other collaborative ranking techniques.


title: Electrostatic Attraction between Overall Neutral Surfaces

abstract:
  Two overall neutral surfaces with positive and negative charged domains
("patches") have been shown in recent experiments to exhibit long-range
attraction when immersed in an ionic solution. Motivated by the experiments, we
calculate analytically the osmotic pressure between such surfaces within the
Poisson-Boltzmann framework, using a variational principle for the
surface-averaged free energy. The electrostatic potential, calculated beyond
the linear Debye-H\"uckel theory, yields an {\it overall attraction} at large
inter-surface separations, over a wide range of the system's controlled length
scales. In particular, the attraction is stronger and occurs at smaller
separations for surface patches of larger size and charge density. In this
large patch limit, we find that the attraction-repulsion crossover separation
is inversely proportional to the square of the patch charge-density and to the
Debye screening length.

categories: cond-mat.soft cond-mat.mtrl-sci cond-mat.stat-mech physics.bio-ph physics.chem-ph


title:
A theta expression of the Hilbert modular functions for $\sqrt{5}$ via
  the periods of $K3$ surfaces

abstract:
  In this paper, we give an extension of the classical story of the elliptic
modular function to the Hilbert modular case for $\mathbb{Q}(\sqrt{5})$. We
construct the period mapping for a family $\mathcal{F}=\{S(X,Y)\}$ of $K3 $
surfaces with $2$ complex parameters $X$ and $Y$. The inverse correspondence of
the period mapping gives a system of generators of Hilbert modular functions
for $\mathbb{Q}(\sqrt{5})$.
  Moreover, we show an explicit expression of this inverse correspondence by
theta constants.


title:
Environmental coupling in ecosystems: From oscillation quenching to
  rhythmogenesis

abstract:
  How do landscape fragmentation affects ecosystems diversity and stability is
an important and complex question in ecology with no simple answer, as
spatially separated habitats where species live are highly dynamic rather than
just static. Taking into account the species dispersal among nearby connected
habitats (or patches) through a common dynamic environment, we model the
consumer-resource interactions with ring type coupled network. Characterizing
the dynamics of consumer-resource interactions in a coupled ecological system
with three fundamental mechanisms: such as the interaction within the patch,
the interaction between the patch and the interaction through a common dynamic
environment, we report the occurrence of various atypical collective behaviors.
We show that, the interplay between dynamic environment and dispersal among
connected patches exhibits the mechanism of generation of oscillations, i.e.,
rhythmogenesis, as well as suppression of oscillations, i.e., amplitude death
and oscillation death. Also, the transition of homogeneous steady state to
inhomogeneous steady state occurs through a co-dimension-2 bifurcation.
Emphasizing a network of spatially extended system, the coupled model exposes
the collective behavior of synchrony-stability relationship with various
synchronization occurrences such as in-phase and out-of-phase.


title: The Fine Structure Constant and Habitable Planets

abstract:
  We use the existence of habitable planets to impose anthropic requirements on
the fine structure constant, $\alpha$. To this effect, we present two
considerations that restrict its value to be very near the one observed. The
first, that the end product of stellar fusion is iron and not one of its
neighboring elements, restricts $\alpha^{-1}$ to be $145\pm 50$. The second,
that radiogenic heat in the Earth's interior remains adequately productive for
billions of years, restricts it to be $145\pm9$. A connection with the grand
unified theory window is discussed, effectively providing a route to probe
ultra-high energy physics with upcoming advances in planetary science.


title: Fractal trajectories of the dynamical system

abstract:
  The scope of the paper is a theoretical analysis of the dynamical system, the
model of which was reduced to Weierstrasse function. A fractal structure of the
trajectory was proved and the entropy of the system information designated.


title:
Functional limit laws for recurrent excited random walks with periodic
  cookie stacks

abstract:
  We consider one-dimensional excited random walks (ERWs) with periodic cookie
stacks in the recurrent regime. We prove functional limit theorems for these
walks which extend the previous results of D. Dolgopyat and E. Kosygina for
excited random walks with "boundedly many cookies per site." In particular, in
the non-boundary recurrent case the rescaled excited random walk converges in
the standard Skorokhod topology to a Brownian motion perturbed at its extrema
(BMPE). While BMPE is a natural limiting object for excited random walks with
boundedly many cookies per site, it is far from obvious why the same should be
true for our model which allows for infinitely many "cookies" at each site.
Moreover, a BMPE has two parameters $\alpha,\beta<1$ and the scaling limits in
this paper cover a larger variety of choices for $\alpha$ and $\beta$ than can
be obtained for ERWs with boundedly many cookies per site.


title: Semicontinuity in Ordered Banach Spaces

abstract:
  We extend the C*-algebra semicontinuity theory of Akemann, Brown and Pedersen
to (pre)ordered Banach spaces.


title: Fast convolution with free-space Green's functions

abstract:
  We introduce a fast algorithm for computing volume potentials - that is, the
convolution of a translation invariant, free-space Green's function with a
compactly supported source distribution defined on a uniform grid. The
algorithm relies on regularizing the Fourier transform of the Green's function
by cutting off the interaction in physical space beyond the domain of interest.
This permits the straightforward application of trapezoidal quadrature and the
standard FFT, with superalgebraic convergence for smooth data. Moreover, the
method can be interpreted as employing a Nystrom discretization of the
corresponding integral operator, with matrix entries which can be obtained
explicitly and rapidly. This is of use in the design of preconditioners or fast
direct solvers for a variety of volume integral equations. The method proposed
permits the computation of any derivative of the potential, at the cost of an
additional FFT.


title:
Regular ambitoric $4$-manifolds: from Riemannian Kerr to a complete
  classification

abstract:
  We show that the conformal structure for the Riemannian analogues of Kerr
black-hole metrics can be given an ambitoric structure. We then discuss the
properties of the moment maps. In particular, we observe that the moment map
image is not locally convex near the singularity corresponding to the ring
singularity in the interior of the black hole. We then proceed to classify
regular ambitoric $4$-orbifolds with some completeness assumptions. The tools
developed also allow us to prove a partial classification of compact Riemannian
$4$-manifolds which admit a Killing $2$-form.


title:
Asymptotic behavior of weighted power variations of fractional Brownian
  motion in Brownian time

abstract:
  We study the asymptotic behavior of weighted power variations of fractional
Brownian motion in Brownian time Z_t:= X_{Y_t}, t >= 0, where X is a fractional
Brownian motion and Y is an independent Brownian motion.


title: An extremely fast halo hot subdwarf star in a wide binary system

abstract:
  New spectroscopic observations of the halo hyper-velocity star candidate SDSS
J121150.27+143716.2 ($V=17.92$ mag) revealed a cool companion to the hot
subdwarf primary. The components have a very similar radial velocity and their
absolute luminosities are consistent with the same distance, confirming the
physical nature of the binary, which is the first double-lined hyper-velocity
candidate. Our spectral decomposition of the Keck/ESI spectrum provided an
sdB+K3V pair, analogous to many long-period subdwarf binaries observed in the
Galactic disk. We found the subdwarf atmospheric parameters: $T_{\rm
eff}=30\,600\pm500$ K, $\log{g}=5.57\pm0.06$ cm s$^{-2}$ and He abundance
$\log(n{\rm He}/n{\rm H})=-3.0\pm0.2$. Oxygen is the most abundant metal in the
hot subdwarf atmosphere, and Mg and Na lines are the most prominent spectral
features of the cool companion, consistent with a metallicity of $[{\rm
Fe}/{\rm H}]=-1.3$. The non-detection of radial velocity variations suggest the
orbital period to be a few hundred days, in agreement with similar binaries
observed in the disk. Using the SDSS-III flux calibrated spectrum we measured
the distance to the system $d=5.5\pm0.5$ kpc, which is consistent with
ultraviolet, optical, and infrared photometric constraints derived from binary
spectral energy distributions. Our kinematic study shows that the Galactic
rest-frame velocity of the system is so high that an unbound orbit cannot be
ruled out. On the other hand, a bound orbit requires a massive dark matter
halo. We conclude that the binary either formed in the halo or it was accreted
from the tidal debris of a dwarf galaxy by the Milky Way.