title:
A photon-photon quantum gate based on a single atom in an optical
  resonator

abstract:
  Two photons in free space pass each other undisturbed. This is ideal for the
faithful transmission of information, but prohibits an interaction between the
photons as required for a plethora of applications in optical quantum
information processing. The long-standing challenge here is to realise a
deterministic photon-photon gate. This requires an interaction so strong that
the two photons can shift each others phase by pi. For polarisation qubits,
this amounts to the conditional flipping of one photon's polarisation to an
orthogonal state. So far, only probabilistic gates based on linear optics and
photon detectors could be realised, as "no known or foreseen material has an
optical nonlinearity strong enough to implement this conditional phase
shift..." [Science 318, 1567]. Meanwhile, tremendous progress in the
development of quantum-nonlinear systems has opened up new possibilities for
single-photon experiments. Platforms range from Rydberg blockade in atomic
ensembles to single-atom cavity quantum electrodynamics. Applications like
single-photon switches and transistors, two-photon gateways, nondestructive
photon detectors, photon routers and nonlinear phase shifters have been
demonstrated, but none of them with the ultimate information carriers, optical
qubits. Here we employ the strong light-matter coupling provided by a single
atom in a high-finesse optical resonator to realise the Duan-Kimble protocol of
a universal controlled phase flip (CPF, pi phase shift) photon-photon quantum
gate. We achieve an average gate fidelity of F=(76.2+/-3.6)% and specifically
demonstrate the capability of conditional polarisation flipping as well as
entanglement generation between independent input photons. Our gate could
readily perform most of the hitherto existing two-photon operations. It also
discloses avenues towards new quantum information processing applications where
photons are essential.


title: A disk asymmetry in motion around the B[e] star MWC158

abstract:
  MWC158 is a star with the B[e] phenomenon that shows strong
spectrophotometric variability (in lines and in UV and visible continuum)
attributed to phases of shell ejection. The evolutionary stage of this star was
never clearly determined. Previous interferometric, spectropolarimetric and
spectro-interferometric studies suggest a disk morphology for its environment.
We investigate the origin of the variability within the inner astronomical unit
of the central star using near-infrared interferometric observations with
PIONIER at the VLTI over a two-year period. We performed an image
reconstruction of the circumstellar environment using the SPARCO method. We
discovered that the morphology of the circumstellar environment could vary on
timescales of weeks or days. We carried out a parametric fit of the data with a
model consisting of a star, a disk and a bright spot that represents a brighter
emission in the disk. We detect strong morphological changes in the first
astronomical unit around the star, that happen on a timescale of few months. We
cannot account for such variability well with a binary model. Our parametric
model fits the data well and allows us to extract the location of the asymmetry
for different epochs. For the first time, we detect a morphological variability
in the environment of MWC158. This variability is reproduced by a model of a
disk and a bright spot. The locations of the bright spot suggest that it is
located in the disk, but its precise motion is not determined. The origin of
the asymmetry in the disk is complex and may be related to asymmetric shell
ejections.


title: Spin-3/2 fields in $D$-dimensional Schwarzschild black hole space-times

abstract:
  In previous works we have studied spin-3/2 fields near 4-dimensional
Schwarzschild black holes. The techniques we developed in that case have now
been extended here to show that it is possible to determine the potential of
spin-3/2 fields near $D$-dimensional black holes by exploiting the radial
symmetry of the system. This removes the need to use the Newman-Penrose
formalism, which is difficult to extend to $D$-dimensional space-times. In this
paper we will derive a general $D$-dimensional gauge invariant effective
potential for spin-3/2 fields near black hole systems. We then use this
potential to determine the quasi-normal modes and absorption probabilities of
spin-3/2 fields near a $D$-dimensional Schwarzschild black hole.


title:
Analytic study of the effect of dark energy-dark matter interaction on
  the growth of structures

abstract:
  Large-scale structure has been shown as a promising cosmic probe for
distinguishing and constraining dark energy models. Using the growth index
parametrization, we obtain an analytic formula for the growth rate of
structures in a coupled dark energy model in which the exchange of
energy-momentum is proportional to the dark energy density. We find that the
evolution of $f \sigma_8$ can be determined analytically once we know the
coupling, the dark energy equation of state, the present value of the dark
energy density parameter and the current mean amplitude of dark matter
fluctuations. After correcting the growth function for the correspondence with
the velocity field through the continuity equation in the interacting model, we
use our analytic result to compare the model's predictions with large-scale
structure observations.


title: Almost Primes in Thin Orbits of Pythagorean Triangles

abstract:
  Let $F=x^2+y^2-z^2$, $x_0 \in \mathbb{Z}^3$ primitive with $F(x_0)=0$, and
$\Gamma \leq SO_F(\mathbb{Z})$ be a finitely generated thin subgroup. We
consider the resulting thin orbits of Pythagorean triples $x_0 \cdot \Gamma$ -
specifically which hypotenuses, areas, and products of all three coordinates
arise. We produce infinitely many $R$-almost primes in these three cases
whenever $\Gamma$ has exponent $\delta_\Gamma>\delta_0(R)$ for explicit $R$,
$\delta_0$.


title: Remarks on functions with bounded Laplacian

abstract:
  $\Delta \psi:=\frac{\partial^2 \psi}{\partial x_1^2}+\frac{\partial^2
\psi}{\partial x_2^2}$ being locally bounded does not imply that $D^2\psi$ is
locally bounded. However, we prove that if $\psi$ is invariant under rotation
by $\frac{2\pi}{m}$, for some $m\geq 3$, and $\Delta \psi$ is locally bounded,
then $$\sup_{x\in B_1(0)}\frac{|\nabla \psi(x)|}{|x|}<\infty.$$ This is sharp
in that there are examples of functions $\psi$ for which $\Delta \psi$ is
locally bounded, which are invariant under rotation by $\pi$ with
$|\psi(x)-\psi(0)|\approx |x|^2 |\log|x||$ as $|x|\rightarrow 0$. This bound
and its generalizations could be of use in different contexts, particularly for
questions about singularity formation in evolution equations. We came upon it
while studying certain singular solutions of the incompressible Euler equations
in two dimensions (see \cite{E}). One other application is to prove boundedness
of $D^2 \psi$ when $\Delta \psi$ is the characteristic function of a set with
self-intersection points (see Section 5). In fact, if $\Delta \psi=\chi_{A}$
and $A$ is the union of sectors emanating from a single point, one can give
necessary and sufficient conditions on $A$ for $D^2 \psi$ to be locally bounded
(see Section 6).


title: Deformation theory of scalar-flat K\"ahler ALE surfaces

abstract:
  We prove a Kuranishi-type theorem for deformations of complex structures on
ALE K\"ahler surfaces. This is used to prove that for any scalar-flat K\"ahler
ALE surface, all small deformations of complex structure also admit scalar-flat
K\"ahler ALE metrics. A local moduli space of scalar-flat K\"ahler ALE metrics
is then constructed, which is shown to be universal up to small diffeomorphisms
(that is, diffeomorphisms which are close to the identity in a suitable sense).
A formula for the dimension of the local moduli space is proved in the case of
a scalar-flat K\"ahler ALE surface which deforms to a minimal resolution of
$\mathbb{C}^2/\Gamma$, where $\Gamma$ is a finite subgroup of ${\rm{U}}(2)$
without complex reflections.


title:
Realistic Observable in Background-Free Quantum Gravity: the Planck-Star
  Tunnelling-Time

abstract:
  A gravitationally collapsed object can bounce-out from its horizon via a
tunnelling process that violates the classical equations in a finite region.
Since tunnelling is a non-perturbative phenomenon, it cannot be described in
terms of quantum fluctuations around a classical solution and a background-free
formulation of quantum gravity is needed to analyze it. Here we use Loop
Quantum Gravity to compute the amplitude for this process, in a first
approximation. The amplitude determines the tunnelling time as a function of
the mass. This is the key information to evaluate the astrophysical relevance
of this process. The calculation offers a template and a concrete example of
how a background-free quantum theory of gravity can be used to compute a
realistical observable quantity.


title:
Large Sets of Orthogonal Sequences Suitable for Applications in CDMA
  Systems

abstract:
  In this paper, we employ the so-called semi-bent functions to achieve
significant improvements over currently known methods regarding the number of
orthogonal sequences per cell that can be assigned to a regular tessellation of
hexagonal cells, typical for certain code-division multiple-access (CDMA)
systems. Our initial design method generates a large family of orthogonal sets
of sequences derived from vectorial semi-bent functions. A modification of the
original approach is proposed to avoid a hard combinatorial problem of
allocating several such orthogonal sets to a single cell of a regular hexagonal
network, while preserving the orthogonality to adjacent cells. This
modification increases the number of users per cell by starting from shorter
codewords and then extending the length of these codewords to the desired
length. The specification and assignment of these orthogonal sets to a regular
tessellation of hexagonal cells have been solved regardless of the parity and
size of $m$ (where $2^m$ is the length of the codewords). In particular, when
the re-use distance is $D=4$ the number of users per cell is $2^{m-2}$ for
almost all $m$, which is twice as many as can be obtained by the best known
methods.


title:
Electric quadrupole transitions of the Bohr Hamiltonian with
  Manning-Rosen potential

abstract:
  Analytical expressions of the wave functions are derived for a Bohr
Hamiltonian with the Manning{Rosen potential in the cases of {\gamma}-unstable
nuclei and axially symmetric prolate deformed ones with {\gamma}=0. By
exploiting the results we have obtained in a recent work on the same theme Ref.
[1], we have calculated the B(E2) transition rates for 34 {\gamma}-unstable and
38 rotational nuclei and compared to experimental data, revealing a qualitative
agreement with the experiment and phase transitions within the ground state
band and showing also that the Manning-Rosen potential is more appropriate for
such calculations than other potentials.


title: Countable Successor Ordinals as Generalized Ordered Topological Spaces

abstract:
  A topological space $L$ is called a linear ordered topological space (LOTS)
whenever there is a linear order $\leq$ on $L$ such that the topology on $L$ is
generated by the open sets of the form $(a, b)$ with $a < b$ and $a, b \in L
\cup \{ -\infty, +\infty \}$. A topological space $X$ is called a generalized
ordered space (GO-space) whenever $X$ is topologically embeddable in a LOTS.
Main Theorem: Let $X$ be a Hausdorff topological space. Assume that any
continuous image of $X$ is a GO-space. Then $X$ is homeomorphic to a countable
successor ordinal (with the order topology).
  The converse trivially holds.


title:
Fast and Accurate Algorithm for Eye Localization for Gaze Tracking in
  Low Resolution Images

abstract:
  Iris centre localization in low-resolution visible images is a challenging
problem in computer vision community due to noise, shadows, occlusions, pose
variations, eye blinks, etc. This paper proposes an efficient method for
determining iris centre in low-resolution images in the visible spectrum. Even
low-cost consumer-grade webcams can be used for gaze tracking without any
additional hardware. A two-stage algorithm is proposed for iris centre
localization. The proposed method uses geometrical characteristics of the eye.
In the first stage, a fast convolution based approach is used for obtaining the
coarse location of iris centre (IC). The IC location is further refined in the
second stage using boundary tracing and ellipse fitting. The algorithm has been
evaluated in public databases like BioID, Gi4E and is found to outperform the
state of the art methods.


title: Learning Convolutional Neural Networks for Graphs

abstract:
  Numerous important problems can be framed as learning from graph data. We
propose a framework for learning convolutional neural networks for arbitrary
graphs. These graphs may be undirected, directed, and with both discrete and
continuous node and edge attributes. Analogous to image-based convolutional
networks that operate on locally connected regions of the input, we present a
general approach to extracting locally connected regions from graphs. Using
established benchmark data sets, we demonstrate that the learned feature
representations are competitive with state of the art graph kernels and that
their computation is highly efficient.


title: Java Generics are Turing Complete

abstract:
  This paper describes a reduction from the halting problem of Turing machines
to subtype checking in Java. It follows that subtype checking in Java is
undecidable, which answers a question posed by Kennedy and Pierce in 2007. It
also follows that Java's type checker can recognize any recursive language,
which improves a result of Gil and Levy from 2016. The latter point is
illustrated by a parser generator for fluent interfaces.


title:
Electronic Structure of the Ferromagnetic Semiconductor Fe-doped Ge
  Revealed by Soft X-ray Angle-Resolved Photoemission Spectroscopy

abstract:
  Ge$_{1-x}$Fe$_{x}$ (Ge:Fe) shows ferromagnetic behavior up to a relatively
high temperature of 210 K, and hence is a promising material for spintronic
applications compatible with Si technology. We have studied its electronic
structure by soft x-ray angle-resolved photoemission spectroscopy (SX-ARPES)
measurements in order to elucidate the mechanism of the ferromagnetism. We
observed finite Fe 3$d$ components in the states at the Fermi level ($E_{F}$)
in a wide region in momentum space and $E_{F}$ was located above the
valence-band maximum (VBM). First-principles supercell calculation also
suggested that the $E_{F}$ is located above the VBM, within the narrow
spin-down $d$($e$) band and within the spin-up impurity band of the deep
acceptor-level origin derived from the strong $p$-$d$($t_{2}$) hybridization.
We conclude that the narrow $d$($e$) band is responsible for the ferromagnetic
coupling between Fe atoms while the acceptor-level-originated band is
responsible for the transport properties of Ge:Fe.


title: Linear continuous surjections of $C_{p}$-spaces over compacta

abstract:
  Let $X$ and $Y$ be compact Hausdorff spaces and suppose that there exists a
linear continuous surjection $T:C_{p}(X) \to C_{p}(Y)$, where $C_{p}(X)$
denotes the space of all real-valued continuous functions on $X$ endowed with
the pointwise convergence topology. We prove that $\dim X=0$ implies $\dim Y =
0$. This generalizes a previous theorem \cite[Theorem 3.4]{LLP} for compact
metrizable spaces. Also we point out that the function space $C_{p}(P)$ over
the pseudo-arc $P$ admits no densely defined linear continuous operator
$C_{p}(P) \to C_{p}([0,1])$ with a dense image.


title:
Tropical and non-Archimedean limits of degenerating families of volume
  forms

abstract:
  We study the asymptotic behavior of volume forms on a degenerating family of
compact complex manifolds. Under rather general conditions, we prove that the
volume forms converge in a natural sense to a Lebesgue-type measure on a
certain simplicial complex. In particular, this provides a measure-theoretic
version of a conjecture by Kontsevich--Soibelman and Gross--Wilson, bearing on
maximal degenerations of Calabi--Yau manifolds.


title:
Exact Simulation of Noncircular or Improper Complex-Valued Stationary
  Gaussian Processes using Circulant Embedding

abstract:
  This paper provides an algorithm for simulating improper (or noncircular)
complex-valued stationary Gaussian processes. The technique utilizes recently
developed methods for multivariate Gaussian processes from the circulant
embedding literature. The method can be performed in $\mathcal{O}(n\log_2 n)$
operations, where $n$ is the length of the desired sequence. The method is
exact, except when eigenvalues of prescribed circulant matrices are negative.
We evaluate the performance of the algorithm empirically, and provide a
practical example where the method is guaranteed to be exact for all $n$, with
an improper fractional Gaussian noise process.


title: Lattices of homomorphisms and pro-Lie groups

abstract:
  Early this century K. H. Hofmann and S. A. Morris introduced the class of
pro-Lie groups which consists of projective limits of finite-dimensional Lie
groups and proved that it contains all compact groups, all locally compact
abelian groups, and all connected locally compact groups and is closed under
the formation of products and closed subgroups. They defined a topological
group $G$ to be almost connected if the quotient group of $G$ by the connected
component of its identity is compact.
  We show here that all almost connected pro-Lie groups as well as their
continuous homomorphic images are $R$-factorizable and
\textit{$\omega$-cellular}, i.e.~every family of $G_\delta$-sets contains a
countable subfamily whose union is dense in the union of the whole family. We
also prove a general result which implies as a special case that if a
topological group $G$ contains a compact invariant subgroup $K$ such that the
quotient group $G/K$ is an almost connected pro-Lie group, then $G$ is
$R$-factorizable and $\omega$-cellular.
  Applying the aforementioned result we show that the sequential closure and
the closure of an arbitrary $G_{\delta,\Sigma}$-set in an almost connected
pro-Lie group $H$ coincide.


title: SPAM: Signal Processing to Analyze Malware

abstract:
  In this article, we explored orthogonal methods to analyze malware motivated
by signal and image processing. Malware samples are represented as images or
signals. Image and signal-based features are extracted to characterize malware.
Our extensive experiments demonstrate the efficacy of our methods on malware
classification and retrieval. We believe that our techniques will open the
scope of signal-and image-based methods to broader fields in computer security.


title:
$d$-imbalance WOM Codes for Reduced Inter-Cell Interference in
  Multi-Level NVMs

abstract:
  In recent years, due to the spread of multi-level non-volatile memories
(NVM), $q$-ary write-once memories (WOM) codes have been extensively studied.
By using WOM codes, it is possible to rewrite NVMs $t$ times before erasing the
cells. The use of WOM codes enables to improve the performance of the storage
device, however, it may also increase errors caused by inter-cell interference
(ICI). This work presents WOM codes that restrict the imbalance between code
symbols throughout the write sequence, hence decreasing ICI. We first specify
the imbalance model as a bound $d$ on the difference between codeword levels.
Then a $2$-cell code construction for general $q$ and input size is proposed.
An upper bound on the write count is also derived, showing the optimality of
the proposed construction. In addition to direct WOM constructions, we derive
closed-form optimal write regions for codes constructed with continuous
lattices. On the coding side, the proposed codes are shown to be competitive
with known codes not adhering to the bounded imbalance constraint. On the
memory side, we show how the codes can be deployed within flash wordlines, and
quantify their BER advantage using accepted ICI models.


title: On Properties of Polynomials in Random Elements

abstract:
  The paper deals with different properties of polynomials in random elements:
bounds for characteristics functionals of polynomials, stochastic
generalization of the Vinogradov mean value theorem, characterization problem,
bounds for probabilities to hit the balls. These results cover the cases where
the random elements take values in finite as well as infinite dimensional
Hilbert spaces.


title:
Initial Conditions for Accurate N-Body Simulations of Massive Neutrino
  Cosmologies

abstract:
  The set-up of the initial conditions in cosmological N-body simulations is
usually implemented by rescaling the desired low-redshift linear power spectrum
to the required starting redshift consistently with the Newtonian evolution of
the simulation. The implementation of this practical solution requires more
care in the context of massive neutrino cosmologies, mainly because of the
non-trivial scale-dependence of the linear growth that characterises these
models. In this work we consider a simple two-fluid, Newtonian approximation
for cold dark matter and massive neutrinos perturbations that can reproduce the
cold matter linear evolution predicted by Boltzmann codes such as CAMB or CLASS
with a 0.1% accuracy or below for all redshift relevant to nonlinear structure
formation. We use this description, in the first place, to quantify the
systematic errors induced by several approximations often assumed in numerical
simulations, including the typical set-up of the initial conditions for massive
neutrino cosmologies adopted in previous works. We then take advantage of the
flexibility of this approach to rescale the late-time linear power spectra to
the simulation initial redshift, in order to be as consistent as possible with
the dynamics of the N-body code and the approximations it assumes. We implement
our method in a public code providing the initial displacements and velocities
for cold dark matter and neutrino particles that will allow accurate, i.e.
one-percent level, numerical simulations for this cosmological scenario.


title: Minimax Lower Bounds for Kronecker-Structured Dictionary Learning

abstract:
  Dictionary learning is the problem of estimating the collection of atomic
elements that provide a sparse representation of measured/collected signals or
data. This paper finds fundamental limits on the sample complexity of
estimating dictionaries for tensor data by proving a lower bound on the minimax
risk. This lower bound depends on the dimensions of the tensor and parameters
of the generative model. The focus of this paper is on second-order tensor
data, with the underlying dictionaries constructed by taking the Kronecker
product of two smaller dictionaries and the observed data generated by sparse
linear combinations of dictionary atoms observed through white Gaussian noise.
In this regard, the paper provides a general lower bound on the minimax risk
and also adapts the proof techniques for equivalent results using sparse and
Gaussian coefficient models. The reported results suggest that the sample
complexity of dictionary learning for tensor data can be significantly lower
than that for unstructured data.


title: Variational Convergence of Discrete Minimal Surfaces

abstract:
  Building on and extending tools from variational analysis, we prove
Kuratowski convergence of sets of simplicial area minimizers to minimizers of
the smooth Douglas-Plateau problem under simplicial refinement. This
convergence is with respect to a topology that is stronger than uniform
convergence of both positions and surface normals.


title: Testing the spherical evolution of cosmic voids

abstract:
  We study the spherical evolution model for voids in $\Lambda$CDM, where the
evolution of voids is governed by dark energy at an earlier time than that for
the whole universe or in overdensities. We show that the presence of dark
energy suppresses the growth of peculiar velocities, causing void
shell-crossing to occur at progressively later epochs as $\Omega_{\Lambda}$
increases. We apply the spherical model to evolve the initial conditions of
N-body simulated voids and compare the resulting final void profiles. We find
that the model is successful in tracking the evolution of voids with radii
greater than $30 h^{-1} \rm Mpc$, implying that void profiles could be used to
constrain dark energy. We find that the initial peculiar velocities of voids
play a significant role in shaping their evolution. Excluding the peculiar
velocity in the evolution model delays the time of shell crossing.


title: Compatible polynomials and edgewise subdivisions

abstract:
  In this paper we answer a question posed by C. A. Athanasiadis. Namely, we
prove that the local $h$-polynomial of the $r$th edgewise subdivision of the
$(n-1)$-dimensional simplex $2^V$ has only real zeros. In doing so we find a
tool, using compatible polynomials, that can be used to check if polynomials in
certain types of families of polynomials have only real zeros.


title:
Reconstructing spacetime from the hologram, even in the classical limit,
  requires physics beyond the Planck scale

abstract:
  We argue in this essay that for classical configurations of gravity in the
AdS/CFT setup, it is in general impossible to reconstruct the bulk geometry
from the leading asymptotic behavior of the classical fields in gravity alone.
This is possible sufficiently near the vacuum, but not more generally. We argue
this by using a counter-example that utilizes the supersymmetric geometries
constructed by Lin, Lunin, and Maldacena. In the dual quantum field theory, the
additional data required to complete the geometry is encoded in modes that near
the vacuum geometry lie beyond the Planck scale.


title:
Thermal Spectrum of Heavy Vector and Axial Vector Mesons in the
  Framework of QCD Sum Rules Method

abstract:
  The masses and the leptonic decay constants of vector and axial vector
heavy-heavy mesons are calculated using the thermal QCD sum rules approach.
While obtaining the QCD sum rules, additional operators in the Wilson expansion
and also temperature dependency of the continuum threshold are taken into
account. The masses and the decay constants remained unchanged up to
$T\simeq100~MeV$. After that point, they start to diminish. At the critical
temperature, the masses decreased about $3\%$, $5\%$ and $14\%$ for the vector
mesons $\Upsilon$, $B_{c}$ and $J/\psi$; $6\%$, $7\%$ and $22\%$ for the axial
vector mesons $\chi_{b1}$, $B_{c}$ and $\chi_{c1}$, respectively. The decay
constants reached about less than $20\%$ of their vacuum values. The obtained
results of the thermal mass and decay constant calculations at zero temperature
are in a very good agreement with the other non-perturbative calculations at
vacuum as well as with the experimental data.


title: Hybrid dynamics in delay-coupled swarms with "mothership" networks

abstract:
  Swarming behavior continues to be a subject of immense interest because of
its centrality in many naturally occurring systems in physics and biology, as
well as its importance in applications such as robotics. Here we examine the
effects on swarm pattern formation from delayed communication and topological
heterogeneity, and in particular, the inclusion of a relatively small number of
highly connected nodes, or "motherships", in a swarm's communication network.
We find generalized forms of basic patterns for networks with general degree
distributions, and a variety of new behaviors including new parameter regions
with multi-stability and hybrid motions in bimodal networks. The latter is an
interesting example of how heterogeneous networks can have dynamics that is a
mix of different states in homogeneous networks, where high and low-degree
nodes have simultaneously distinct behavior.


title:
Multistep Model for Predicting Upper-Limb 3D Isometric Force Application
  from Pre-Movement Electrocorticographic Features

abstract:
  Neural correlates of movement planning onset and direction may be present in
human electrocorticography in the signal dynamics of both motor and non-motor
cortical regions. We use a three-stage model of jPCA reduced-rank hidden Markov
model (jPCA-RR-HMM), regularized shrunken-centroid discriminant analysis (RDA),
and LASSO regression to extract direction-sensitive planning information and
movement onset in an upper-limb 3D isometric force task in a human subject.
This mode achieves a relatively high true positive force-onset prediction rate
of 60% within 250ms, and an above-chance 36% accuracy (17% chance) in
predicting one of six planned 3D directions of isometric force using
pre-movement signals. We also find direction-distinguishing information up to
400ms before force onset in the pre-movement signals, captured by electrodes
placed over the limb-ipsilateral dorsal premotor regions. This approach can
contribute to more accurate decoding of higher-level movement goals, at earlier
timescales, and inform sensor placement. Our results also contribute to further
understanding of the spatiotemporal features of human motor planning.


title:
The scalar-scalar-tensor inflationary three-point function in the axion
  monodromy model

abstract:
  The axion monodromy model involves a canonical scalar field that is governed
by a linear potential with superimposed modulations. The modulations in the
potential are responsible for a resonant behavior which gives rise to
persisting oscillations in the scalar and, to a smaller extent, in the tensor
power spectra. Interestingly, such spectra have been shown to lead to an
improved fit to the cosmological data than the more conventional, nearly scale
invariant, primordial power spectra. The scalar bi-spectrum in the model too
exhibits continued modulations and the resonance is known to boost the
amplitude of the scalar non-Gaussianity parameter to rather large values. An
analytical expression for the scalar bi-spectrum had been arrived at earlier
which, in fact, has been used to compare the model with the cosmic microwave
background anisotropies at the level of three-point functions involving
scalars. In this work, with future applications in mind, we arrive at a similar
analytical template for the scalar-scalar-tensor cross-correlation. We also
analytically establish the consistency relation (in the squeezed limit) for
this three-point function. We conclude with a summary of the main results
obtained.


title:
In-drop capillary spooling of spider capture thread inspires hybrid
  fibers with mixed solid-liquid mechanical properties

abstract:
  An essential element in the web-trap architecture, the capture silk spun by
ecribellate orb spiders consists of glue droplets sitting astride a silk
filament. Mechanically this thread presents a mixed solid-liquid behavior
unknown to date. Under extension, capture silk behaves as a particularly
stretchy solid, owing to its molecular nanosprings, but it totally switches
behavior in compression to now become liquid-like: It shrinks with no apparent
limit while exerting a constant tension. Here, we unravel the physics
underpinning the unique behavior of this "liquid wire" and demonstrate that its
mechanical response originates in the shape-switching of the silk filament
induced by buckling within the droplets. Learning from this natural example of
geometry and mechanics, we manufactured programmable liquid wires that present
previously unidentified pathways for the design of new hybrid solid-liquid
materials. This article is available in open access with supplementary
materials on the PNAS website.


title:
Migration and Growth of Protoplanetary Embryos III: Mass and Metallicity
  Dependence for FGKM main-sequence stars

abstract:
  Radial velocity and transit surveys have found that the fraction of FGKM
stars with close-in super-Earth(s) ($\eta_\oplus$) is around $30 \%- 50\%$,
independent of the stellar mass $M_\ast$ and metallicity $Z_\ast$. In contrast,
the fraction of solar-type stars harboring one or more gas giants ($\eta_J $)
with masses $M_{\rm p} > 100 \ M_\oplus $ is nearly $ 10\%-15\%$, and it
appears to increase with both $M_\ast$ and $Z_\ast$. Regardless of the
properties of their host stars, the total mass of some multiple super-Earth
systems exceeds the core mass of Jupiter and Saturn. We suggest that both
super-Earths and supercritical cores of gas giants were assembled from a
population of embryos that underwent convergent type I migration from their
birthplaces to a transition location between viscously heated and irradiation
heated disk regions. We attribute the cause for the $\eta_\oplus$-$\eta_{\rm
J}$ dichotomy to conditions required for embryos to merge and to acquire
supercritical core mass ($M_c \sim 10 \ M_\oplus$) for the onset of efficient
gaseous envelope accretion. We translate this condition into a critical disk
accretion rate, and our analysis and simulation results show that it weakly
depends on $M_\ast$ and decreases with metallicity of disk gas $Z_{\rm d}$. We
find that embryos are more likely to merge into supercritical cores around
relatively massive and metal-rich stars. This dependence accounts for the
observed $\eta_{\rm J}$-$M_\ast$. We also consider the $Z_{\rm d}$-$Z_\ast$
dispersed relationship and reproduce the observed $\eta_J$-$Z_\ast$
correlation.


title: Shear Viscosity of Turbulent Chiral Plasma

abstract:
  It is well known that the difference between the chemical potentials of
left-handed and right-handed particles in a parity violating (chiral) plasma
can lead to an instability. We show that the chiral instability may drive
turbulent transport. Further we estimate the anomalous viscosity of chiral
plasma arising from the enhanced collisionality due to turbulence.


title:
Dataflow matrix machines as programmable, dynamically expandable,
  self-referential generalized recurrent neural networks

abstract:
  Dataflow matrix machines are a powerful generalization of recurrent neural
networks. They work with multiple types of linear streams and multiple types of
neurons, including higher-order neurons which dynamically update the matrix
describing weights and topology of the network in question while the network is
running. It seems that the power of dataflow matrix machines is sufficient for
them to be a convenient general purpose programming platform. This paper
explores a number of useful programming idioms and constructions arising in
this context.


title:
A Preconditioned Low-Rank Projection Method with a Rank-Reduction Scheme
  for Stochastic Partial Differential Equations

abstract:
  In this study, we consider the numerical solution of large systems of linear
equations obtained from the stochastic Galerkin formulation of stochastic
partial differential equations. We propose an iterative algorithm that exploits
the Kronecker product structure of the linear systems. The proposed algorithm
efficiently approximates the solutions in low-rank tensor format. Using
standard Krylov subspace methods for the data in tensor format is
computationally prohibitive due to the rapid growth of tensor ranks during the
iterations. To keep tensor ranks low over the entire iteration process, we
devise a rank-reduction scheme that can be combined with the iterative
algorithm. The proposed rank-reduction scheme identifies an important subspace
in the stochastic domain and compresses tensors of high rank on-the-fly during
the iterations. The proposed reduction scheme is a multilevel method in that
the important subspace can be identified inexpensively in a coarse spatial grid
setting. The efficiency of the proposed method is illustrated by numerical
experiments on benchmark problems.


title:
Flow sensing by buckling monitoring of electrothermally actuated
  double-clamped micro beams

abstract:
  We report on a flow sensing approach based on deflection monitoring of micro
beams buckled by the compressive thermal stress due to electrothermal Joules
heating. The air stream convectively cooling the device affects both the
critical buckling values of the electric current and the postbuckling
deflections of the structure. After calibration, the flow velocity was obtained
from the deflections measurements. The quasi-static responses of 2000 microns
long, 10 microns wide and 30 microns high single crystal silicon beam
transduced using image processing were consistent with the prediction of the
reduced order model, which couples thermoelectric, thermofluidic and structural
domains. The deflection sensitivity of 1.5 microns/(m/s) and the critical
current sensitivity of 0.4 mA/(m/s) were registered in the experiments. Our
model and experimental results collectively demonstrate feasibility of the
sensing approach and further suggest that simple, robust and potentially
downscalable beam-type devices may have use in flow velocity and wall shear
stress sensors.


title:
Behavior of $R$-groups for $p$-adic inner forms of quasi-split special
  unitary groups

abstract:
  We study $R$-groups for $p$-adic inner forms of quasi-split special unitary
groups. We prove Arthur's conjecture, the isomorphism between the Knapp-Stein
$R$-group and the Langlands-Arthur $R$-group, for quasi-split special unitary
groups and their inner forms. Furthermore, we investigate the invariance of the
Knapp-Stein $R$-group within $L$-packets and between inner forms. This work is
applied to transferring known results in the second-named author's earlier work
for quasi-split special unitary groups to their non quasi-split inner forms.


title: On realization of some twisted toroidal Lie algebras

abstract:
  Toroidal Lie algebras are generalizations of affine Lie algebras. In 1990,
Moody, Rao and Yokonuma gave a presentation for untwisted toroidal Lie
algebras. In this paper we give a presentation for the twisted toroidal Lie
algebras of type $A$ and $D$ constructed by Fu and Jiang.


title:
Critical percolation on any quasi-transitive graph of exponential growth
  has no infinite clusters

abstract:
  We prove that critical percolation on any quasi-transitive graph of
exponential volume growth does not have a unique infinite cluster. This allows
us to deduce from earlier results that critical percolation on any graph in
this class does not have any infinite clusters. The result is new when the
graph in question is either amenable or nonunimodular.


title:
Ponderomotive laser channelling and multi-channelling in homogeneous
  underdense plasma

abstract:
  We have studied laser pulse channeling in underdense plasma by means of
analytical theory and 3D PIC simulations. The most significant result of this
paper is the demonstration of the single fully evacuated stationary channel
solution can be reached an asymptotic state in PIC simulations. In the lower
density and for a laser power above channeling power, we were able to reproduce
in PIC simulations the analytical curve. We showed that single channels are
stable structures against symmetric perturbations. We also studied the
formation of the ring structure in theory and simulations. An evacuated ring
enclosed by an electron filament was observed in our 3D simulations. However
they always coexist with the main laser mode. The threshold power for ring
structure formation is found. Our studies on stability of the rings against
asymmetric perturbations show that ring structure is not stable against
azimuthal perturbations. The growth rate of the instability is shorter for
higher densities and it is therefore more effective at higher densities.


title: Fuzzy Sets Across the Natural Language Generation Pipeline

abstract:
  We explore the implications of using fuzzy techniques (mainly those commonly
used in the linguistic description/summarization of data discipline) from a
natural language generation perspective. For this, we provide an extensive
discussion of some general convergence points and an exploration of the
relationship between the different tasks involved in the standard NLG system
pipeline architecture and the most common fuzzy approaches used in linguistic
summarization/description of data, such as fuzzy quantified statements,
evaluation criteria or aggregation operators. Each individual discussion is
illustrated with a related use case. Recent work made in the context of
cross-fertilization of both research fields is also referenced. This paper
encompasses general ideas that emerged as part of the PhD thesis "Application
of fuzzy sets in data-to-text systems". It does not present a specific
application or a formal approach, but rather discusses current high-level
issues and potential usages of fuzzy sets (focused on linguistic summarization
of data) in natural language generation.


title: Thermodynamics of perfect fluids from scalar field theory

abstract:
  The low-energy dynamics of relativistic continuous media is given by a
shift-symmetric effective theory of four scalar fields. These scalars describe
the embedding in spacetime of the medium and play the role of St\"uckelberg
fields for spontaneously broken spatial and time translations. Perfect fluids
are selected imposing a stronger symmetry group or reducing the field content
to a single scalar. We explore the relation between the field theory
description of perfect fluids to thermodynamics. By drawing the correspondence
between the allowed operators at leading order in derivatives and the
thermodynamic variables, we find that a complete thermodynamic picture requires
the four Stuckelberg fields. We show that thermodynamic stability plus the
null-energy condition imply dynamical stability. We also argue that a
consistent thermodynamic interpretation is not possible if any of the shift
symmetries is explicitly broken.


title: Combat Models for RTS Games

abstract:
  Game tree search algorithms, such as Monte Carlo Tree Search (MCTS), require
access to a forward model (or "simulator") of the game at hand. However, in
some games such forward model is not readily available. This paper presents
three forward models for two-player attrition games, which we call "combat
models", and show how they can be used to simulate combat in RTS games. We also
show how these combat models can be learned from replay data. We use StarCraft
as our application domain. We report experiments comparing our combat models
predicting a combat output and their impact when used for tactical decisions
during a real game.


title:
Resonant optomechanics with a vibrating carbon nanotube and a
  radio-frequency cavity

abstract:
  In an optomechanical setup, the coupling between cavity and resonator can be
increased by tuning them to the same frequency. We study this interaction
between a carbon nanotube resonator and a radio-frequency circuit. In this
resonant regime, the vacuum optomechanical coupling is enhanced by the DC
voltage coupling the cavity and the mechanical resonator. Using the cavity to
detect the nanotube's motion, we observe and simulate interference between
mechanical and electrical oscillations. We measure the mechanical ring-down and
show that further improvements to the system could enable measurement of
mechanical motion at the quantum limit.


title: A note on Grothendieck's standard conjectures of type C and D

abstract:
  Grothendieck conjectured in the sixties that the even Kunneth projector (with
respect to a Weil cohomology theory) is algebraic and that the homological
equivalence relation on algebraic cycles coincides with the numerical
equivalence relation. In this note we extend these celebrated conjectures from
smooth projective schemes to the broad setting of smooth proper dg categories.
As an application, we prove that Grothendieck's original conjectures are
invariant under homological projective duality. This leads to a proof of
Grothendieck's conjectures in the case of intersections of quadrics, linear
sections of determinantal varieties, and intersections of bilinear divisors.
Along the way, we prove also the case of quadric fibrations.


title:
Global well-posedness of advective Lotka-Volterra competition systems
  with nonlinear diffusion

abstract:
  This paper investigates the global well-posedness of a class of
reaction-advection-diffusion models with nonlinear diffusion and Lotka-Volterra
dynamics. We prove the existence and uniform boundedness of the global-in-time
solutions to the fully parabolic systems under certain growth conditions on the
diffusion and sensitivity functions. Global existence and uniform boundedness
of the corresponding parabolic-elliptic system are also obtained. Our results
suggest that attraction (positive taxis) inhibits blowups in Lotka-Volterra
competition systems.


title:
Identification and Estimation of Causal Effects with Outcomes Truncated
  by Death

abstract:
  It is common in medical studies that the outcome of interest is truncated by
death, meaning that a subject has died before the outcome could be measured. In
this case, restricted analysis among survivors may be subject to selection
bias. Hence, it is of interest to estimate the survivor average causal effect,
defined as the average causal effect among the subgroup consisting of subjects
who would survive under either exposure. In this paper, we consider the
identification and estimation problems of the survivor average causal effect.
We propose to use a substitution variable in place of the latent membership in
the always-survivor group. The identification conditions required for a
substitution variable are conceptually similar to conditions for a conditional
instrumental variable, and may apply to both randomized and observational
studies. We show that the survivor average causal effect is identifiable with
use of such a substitution variable, and propose novel model parameterizations
for estimation of the survivor average causal effect under our identification
assumptions. Our approaches are illustrated via simulation studies and a data
analysis.


title:
Iwasawa theory of elliptic modular forms over imaginary quadratic fields
  at non-ordinary primes

abstract:
  We formulate integral Iwasawa main conjectures for suitable twists of a
newform $f$ that is non-ordinary at $p$, over the cyclotomic
$\mathbb{Z}_p$-extension, the anticyclotomic $\mathbb{Z}_p$-extensions (in both
the definite and the indefinite cases) as well as the
$\mathbb{Z}_p^2$-extension of an imaginary quadratic field $K$ where $p$
splits. In order to do so, we define Kobayashi-Sprung-style signed Coleman
maps, which we use to introduce doubly-signed Selmer groups. In the same
spirit, we construct signed (integral) Beilinson-Flach elements (out of the
collection of unbounded Beilinson-Flach elements of Loeffler-Zerbes), which we
use to define doubly-signed $p$-adic $L$-functions. The main conjecture then
relates these two set of objects. Furthermore, we show that the integral
Beilinson-Flach elements form a locally restricted Euler system, that in turn
allows us to deduce (under certain technical assumptions) one inclusion in each
one of the four main conjectures we formulate here (which may be turned into
equalities under favourable circumstances).


title:
Axion Experiments to Algebraic Geometry: Testing Quantum Gravity via the
  Weak Gravity Conjecture

abstract:
  Common features of known quantum gravity theories may hint at the general
nature of quantum gravity. The absence of continuous global symmetries is one
such feature. This inspired the Weak Gravity Conjecture, which bounds masses of
charged particles. We propose the Lattice Weak Gravity Conjecture, which
further requires the existence of an infinite tower of particles of all
possible charges under both abelian and nonabelian gauge groups and directly
implies a cutoff for quantum field theory. It holds in a wide variety of string
theory examples and has testable consequences for the real world and for pure
mathematics. We sketch some implications of these ideas for models of
inflation, for the QCD axion (and LIGO), for conformal field theory, and for
algebraic geometry.


title:
Interference of the Bloch phase in layered materials with stacking
  shifts

abstract:
  In periodic systems, electronic wave functions of the eigenstates exhibit the
periodically modulated Bloch phases and are characterized by their wave numbers
${\bf k}$. We theoretically address the effects of the Bloch phase in general
layered materials with stacking shift. When the interlayer shift and the Bloch
wave vector ${\bf k}$ satisfy certain conditions, interlayer transitions of
electrons are prohibited by the interference of the Bloch phase. We specify the
manifolds in the ${\bf k}$ space where the hybridization of the Bloch states
between the layers is suppressed in accord with the stacking shift. These
manifolds, named stacking-adapted interference manifolds (SAIM), are obviously
applicable to general layered materials regardless of detailed atomic
configuration within the unit cell. We demonstrate the robustness and
usefulness of the SAIM with first-principles calculations for layered boron
nitride, transition-metal dichalcogenide, graphite, and black phosphorus. We
also apply the SAIM to general three-dimensional crystals to derive special
${\bf k}$-point paths for the respective Bravais lattices, along which the
Bloch-phase interference strongly suppresses the band dispersion. Our theory
provides a general and novel view on the anisotropic electronic kinetics
intrinsic to the periodic-lattice structure.


title: The Di-Photon Excess in a Perturbative SUSY Model

abstract:
  We show that a 750 GeV di-photon excess as reported by the ATLAS and CMS
experiments can be reproduced by the Minimal Dirac Gaugino Supersymmetric
Standard Model (MDGSSM) without the need of any ad-hoc addition of new states.
The scalar resonance is identified with the spin-0 partner of the Dirac bino.
We perform a thorough analysis of constraints coming from the mixing of the
scalar with the Higgs boson, the stability of the vacuum and the requirement of
perturbativity of the couplings up to very high energy scales. We exhibit
examples of regions of the parameter space that respect all the constraints
while reproducing the excess. We point out how trilinear couplings that are
expected to arise in supersymmetry-breaking mediation scenarios, but were
ignored in the previous literature on the subject, play an important role.


title:
Differences in the structural properties and star-formation rates of
  field and cluster galaxies at z~1

abstract:
  We investigate the dependance of galaxy sizes and star-formation rates (SFRs)
on environment using a mass-limited sample of quiescent and star-forming
galaxies with M>10^9.5 at z=0.92 selected from the NMBS survey. Using the GEEC2
spectroscopic cluster catalog and the accurate photometric redshifts from NMBS,
we select quiescent and star-forming cluster (sigma=490 km/s) galaxies within
two virial radius, Rvir, intervals of 0.5<Rvir<2 and Rvir<0.5. Galaxies
residing outside of 2 Rvir of both the cluster centres and additional candidate
over-densities are defined as our field sample. Galaxy structural parameters
are measured from the COSMOS legacy HST/ACS F814W image. The sizes and Sersic
indices of quiescent field and cluster galaxies have the same distribution
regardless of Rvir. However, cluster star-forming galaxies within 0.5 Rvir have
lower mass-normalised average sizes, by 16${\pm}7\%$, and a higher fraction of
Sersic indices with n>1, than field star-forming galaxies. The average SFRs of
star-forming cluster galaxies show a trend of decreasing SFR with clustocentric
radius. The mass-normalised average SFR of cluster star-forming galaxies is a
factor of 2-2.5 (7-9 sigma) lower than that of star-forming galaxies in the
field. While we find no significant dependence on environment for quiescent
galaxies, the properties of star-forming galaxies are affected, which could be
the result of environment acting on their gas content.


title:
Direct Imaging discovery of a second planet candidate around the
  possibly transiting planet host CVSO 30

abstract:
  We surveyed the 25 Ori association for direct-imaging companions. This
association has an age of only few million years. Among other targets, we
observed CVSO 30, which has recently been identified as the first T Tauri star
found to host a transiting planet candidate. We report on photometric and
spectroscopic high-contrast observations with the Very Large Telescope, the
Keck telescopes, and the Calar Alto observatory. They reveal a directly imaged
planet candidate close to the young M3 star CVSO 30. The JHK-band photometry of
the newly identified candidate is at better than 1 sigma consistent with
late-type giants, early-T and early-M dwarfs, and free-floating planets. Other
hypotheses such as galaxies can be excluded at more than 3.5 sigma. A lucky
imaging z' photometric detection limit z'= 20.5 mag excludes early-M dwarfs and
results in less than 10 MJup for CVSO 30 c if bound. We present spectroscopic
observations of the wide companion that imply that the only remaining
explanation for the object is that it is the first very young (< 10 Myr)
L-T-type planet bound to a star, meaning that it appears bluer than expected as
a result of a decreasing cloud opacity at low effective temperatures. Only a
planetary spectral model is consistent with the spectroscopy, and we deduce a
best-fit mass of 4-5 Jupiter masses (total range 0.6-10.2 Jupiter masses). This
means that CVSO 30 is the first system in which both a close-in and a wide
planet candidate are found to have a common host star. The orbits of the two
possible planets could not be more different: they have orbital periods of
10.76 hours and about 27000 years. The two orbits may have formed during a
mutual catastrophic event of planet-planet scattering.


title:
Real hypersurfaces in the complex quadric with parallel structure Jacobi
  operator

abstract:
  First we introduce the notion of parallel structure Jacobi operator for real
hypersurfaces in the complex quadric $Q^m = SO_{m+2}/SO_mSO_2$ . Next we give a
complete classification of real hypersurfaces in $Q^m = SO_{m+2}/SO_mSO_2$ with
parallel structure Jacobi operator.


title: Existence and uniqueness theorem for ODE: an overview

abstract:
  The study of existence and uniqueness of solutions became important due to
the lack of general formula for solving nonlinear ordinary differential
equations (ODEs). Compact form of existence and uniqueness theory appeared
nearly 200 years after the development of the theory of differential equation.
In the article, we shall discuss briefly the differences between linear and
nonlinear first order ODE in context of existence and uniqueness of solutions.
Special emphasis is given on the Lipschitz continuous functions in the
discussion.


title:
Maximal $L^p-L^q$ regularity to the Stokes Problem with Navier boundary
  conditions

abstract:
  We prove in this paper some results on the complex and fractional powers of
the Stokes operator with slip frictionless boundary conditions involving the
stress tensor. This is fundamental and plays an important role in the
associated parabolic problem and will be used to prove maximal $L^{p}-L^{q}$
regularity results for the non-homogeneous Stokes problem.


title: Lossless Intra Coding in HEVC with Integer-to-Integer DST

abstract:
  It is desirable to support efficient lossless coding within video coding
standards, which are primarily designed for lossy coding, with as little
modification as possible. A simple approach is to skip transform and
quantization, and directly entropy code the prediction residual, but this is
inefficient for compression. A more efficient and popular approach is to
process the residual block with DPCM prior to entropy coding. This paper
explores an alternative approach based on processing the residual block with
integer-to-integer (i2i) transforms. I2i transforms map integers to integers,
however, unlike the integer transforms used in HEVC for lossy coding, they do
not increase the dynamic range at the output and can be used in lossless
coding. We use both an i2i DCT from the literature and a novel i2i
approximation of the DST. Experiments with the HEVC reference software show
competitive results.


title: Adjoint Methods for Guiding Adaptive Mesh Refinement in Tsunami Modeling

abstract:
  One difficulty in developing numerical methods for tsunami modeling is the
fact that solutions contain regions where much higher resolution is required
than elsewhere in the domain, particularly since the solution may contain
discontinuities or other localized features. The Clawpack software deals with
this issue by using block-structured adaptive mesh refinement to selectively
refine around propagating waves. For problems where only a target area of the
total solution is of interest (e.g. one coastal community), a method that
allows identifying and refining the grid only in regions that influence this
target area would significantly reduce the computational cost of finding a
solution.
  In this work, we show that solving the time-dependent adjoint equation and
using a suitable inner product with the forward solution allows more precise
refinement of the relevant waves. We present examples solving the shallow water
equations in one and two dimensions. To perform these simulations, the use of
the adjoint method has been integrated into the adaptive mesh refinement
strategy of the open source GeoClaw software. We also present results that show
that the accuracy of the solution is maintained and the computational time
required is significantly reduced through the integration of the adjoint method
into adaptive mesh refinement.


title: Discovery of a Long-Lived, High Amplitude Dusty Infrared Transient

abstract:
  We report the detection of an infrared selected transient which has lasted at
least 5 years, first identified by a large mid-infrared and optical outburst
from a faint X-ray source detected with the Chandra X-ray Observatory. In this
paper we rule out several scenarios for the cause of this outburst, including a
classical nova, a luminous red nova, AGN flaring, a stellar merger, and
intermediate luminosity optical transients, and interpret this transient as the
result of a Young Stellar Object (YSO) of at least solar mass accreting
material from the remains of the dusty envelope from which it formed, in
isolation from either a dense complex of cold gas or massive star formation.
This object does not fit neatly into other existing categories of large
outbursts of YSOs (FU Orionis types) which may be a result of the object's
mass, age, and environment. It is also possible that this object is a new type
of transient unrelated to YSOs.


title: Quantum Spin Liquid in a Breathing Kagome Lattice

abstract:
  Motivated by recent experiments on the vanadium oxyfluoride material DQVOF,
we examine possible spin liquid phases on a breathing kagome lattice of S=1/2
spins. By performing a projective symmetry group analysis, we determine the
possible phases for both fermionic and bosonic $\mathbb{Z}_2$ spin liquids on
this lattice, and establish the correspondence between the two. The nature of
the ground state of the Heisenberg model on the isotropic kagome lattice is a
hotly debated topic, with both $\mathbb{Z}_2$ and U(1) spin liquids argued to
be plausible ground states. Using variational Monte Carlo techniques, we show
that a gapped $\mathbb{Z}_2$ spin liquid emerges as the clear ground state in
the presence of this breathing anisotropy. Our results suggest that the
breathing anisotropy helps to stabilize this spin liquid ground state, which
may aid us in understanding the results of experiments and help to direct
future numerical studies on these systems.


title:
NIHAO IX: the role of gas inflows and outflows in driving the
  contraction and expansion of cold dark matter haloes

abstract:
  We use ~100 cosmological galaxy formation zoom-in simulations using the
smoothed particle hydrodynamics code {\sc gasoline} to study the effect of
baryonic processes on the mass profiles of cold dark matter haloes. The haloes
in our study range from dwarf (M_{200}~10^{10}Msun) to Milky Way
(M_{200}~10^{12}Msun) masses. Our simulations exhibit a wide range of halo
responses, primarily varying with mass, from expansion to contraction, with up
to factor ~10 changes in the enclosed dark matter mass at one per cent of the
virial radius. Confirming previous studies, the halo response is correlated
with the integrated efficiency of star formation:
e_SF=(M_{star}/M_{200})/(\Omega_b/\Omega_m). In addition we report a new
correlation with the compactness of the stellar system: e_R=r_{1/2}/R_{200}. We
provide an analytic formula depending on e_SF and e_R for the response of cold
dark matter haloes to baryonic processes. An observationally testable
prediction is that, at fixed mass, larger galaxies experience more halo
expansion, while the smaller galaxies more halo contraction. This diversity of
dark halo response is captured by a toy model consisting of cycles of adiabatic
inflow (causing contraction) and impulsive gas outflow (causing expansion). For
net outflow, or equal inflow and outflow fractions, f, the overall effect is
expansion, with more expansion with larger f. For net inflow, contraction
occurs for small f (large radii), while expansion occurs for large f (small
radii), recovering the phenomenology seen in our simulations. These
regularities in the galaxy formation process provide a step towards a fully
predictive model for the structure of cold dark matter haloes.


title:
Minute-Timescale >100 MeV gamma-ray variability during the giant
  outburst of quasar 3C 279 observed by Fermi-LAT in 2015 June

abstract:
  On 2015 June 16, Fermi-LAT observed a giant outburst from the flat spectrum
radio quasar 3C 279 with a peak $>100$ MeV flux of $\sim3.6\times10^{-5}\;{\rm
photons}\;{\rm cm}^{-2}\;{\rm s}^{-1}$ averaged over orbital period intervals.
It is the historically highest $\gamma$-ray flux observed from the source
including past EGRET observations, with the $\gamma$-ray isotropic luminosity
reaching $\sim10^{49}\;{\rm erg}\;{\rm s}^{-1}$. During the outburst, the Fermi
spacecraft, which has an orbital period of 95.4 min, was operated in a special
pointing mode to optimize the exposure for 3C 279. For the first time,
significant flux variability at sub-orbital timescales was found in blazar
observations by Fermi-LAT. The source flux variability was resolved down to
2-min binned timescales, with flux doubling times less than 5 min. The observed
minute-scale variability suggests a very compact emission region at hundreds of
Schwarzschild radii from the central engine in conical jet models. A minimum
bulk jet Lorentz factor ($\Gamma$) of 35 is necessary to avoid both internal
$\gamma$-ray absorption and super-Eddington jet power. In the standard
external-radiation-Comptonization scenario, $\Gamma$ should be at least 50 to
avoid overproducing the synchrotron-self-Compton component. However, this
predicts extremely low magnetization ($\sim5\times10^{-4}$). Equipartition
requires $\Gamma$ as high as 120, unless the emitting region is a small
fraction of the dissipation region. Alternatively, we consider $\gamma$ rays
originating as synchrotron radiation of $\gamma_{\rm e}\sim1.6\times10^6$
electrons, in magnetic field $B\sim1.3$ kG, accelerated by strong electric
fields $E\sim B$ in the process of magnetoluminescence. At such short distance
scales, one cannot immediately exclude production of $\gamma$ rays in hadronic
processes.


title:
Unveiling the nature of bright z ~ 7 galaxies with the Hubble Space
  Telescope

abstract:
  We present new Hubble Space Telescope/Wide Field Camera 3 imaging of 25
extremely luminous (-23.2 < M_ UV < -21.2) Lyman-break galaxies (LBGs) at z ~
7. The sample was initially selected from 1.65 deg^2 of ground-based imaging in
the UltraVISTA/COSMOS and UDS/SXDS fields, and includes the extreme Lyman-alpha
emitters, `Himiko' and `CR7'. A deconfusion analysis of the deep Spitzer
photometry available suggests that these galaxies exhibit strong rest-frame
optical nebular emission lines (EW_0(H_beta + [OIII]) > 600A). We find that
irregular, multiple-component morphologies suggestive of clumpy or merging
systems are common (f_multi > 0.4) in bright z ~ 7 galaxies, and ubiquitous at
the very bright end (M_UV < -22.5). The galaxies have half-light radii in the
range r_1/2 ~ 0.5-3 kpc. The size measurements provide the first determination
of the size-luminosity relation at z ~ 7 that extends to M_UV ~ -23. We find
the relation to be steep with r_1/2 ~ L^1/2. Excluding clumpy, multi-component
galaxies however, we find a shallower relation that implies an increased
star-formation rate surface density in bright LBGs. Using the new, independent,
HST/WFC3 data we confirm that the rest-frame UV luminosity function at z ~ 7
favours a power-law decline at the bright-end, compared to an exponential
Schechter function drop-off. Finally, these results have important implications
for the Euclid mission, which we predict will detect > 1000 similarly bright
galaxies at z ~ 7. Our new HST imaging suggests that the vast majority of these
galaxies will be spatially resolved by Euclid, mitigating concerns over dwarf
star contamination.


title:
Comparing rotation curve observations to hydrodynamic {\Lambda}CDM
  simulations of galaxies

abstract:
  The formation of the disk and feedback from supernova winds impacts the
distribution of dark matter in galaxies. Recently, Di Cintio et al. (2014b)
characterized the halo response from baryonic processes in hydrodynamical
simulations via a dependence on the ratio of stellar-to-halo mass
($M_{\star}/M_{{\rm halo}}$). The (stellar) mass dependent halo profile links
together the local and global properties of the halo (e.g. inner slope and
$M_{{\rm halo}}$) which allows for measurements of $M_{{\rm halo}}$ without
virial tracers. We compile a large sample of rotation curves from the
literature to test this halo profile. We find that this halo profile can
explain rotation curve observations over a wide range of $M_{\star}$. However,
the global results from our sample are inconsistent with a $\Lambda$ cold dark
matter universe. We do not find the expected correlation between the halo
concentration and $M_{{\rm halo}}$ and there is significantly larger scatter
than expected. Furthermore, a large portion of galaxies below $M_{\star} \sim
10^{9}\,M_{\odot}$ are found to be hosted by smaller halos than expectations
from the abundance matching technique. We find our results are robust to
statistical priors and systematic effects such as inclination angle, asymmetric
drift correction, data source, and uncertainties in stellar mass-to-light
ratios. This suggests either a mischaracterization of the halo response due to
baryonic processes or additional non-standard dark matter physics.


title: Soft Gamma Rays from Heavy WIMPs

abstract:
  We propose an explanation of the galactic center gamma ray excess by
supersymmetric WIMPs as heavy as 500 GeV. The lightest neutralino annihilates
into vector-like leptons or quarks which cascade decay through intermediate
Higgs bosons. Due to the long decay chains, the gamma ray spectrum is much
softer than naively expected and peaks at GeV energies. The model predicts
correlated diboson and dijet signatures to be tested at the LHC.


title: Lepton number symmetry as a way to testable leptogenesis

abstract:
  We propose a minimal and motivated extension of the Standard Model
characterised by an approximate lepton number conservation, which is able to
simultaneously generate neutrino masses and to account for a successful
baryogenesis via leptogenesis. The sterile fermions involved in the
leptogenesis process have masses at the GeV scale. We determine the viable
parameter space that complies with both the neutrino and baryogenesis
phenomenology, and analyse the different regimes for the generation of a lepton
asymmetry in the early Universe (weak and strong-washout) in order to determine
their testability in future experimental facilities.


title:
High Frequency Cluster Radio Galaxies: Luminosity Functions and
  Implications for SZE Selected Cluster Samples

abstract:
  We study the overdensity of point sources in the direction of X-ray-selected
galaxy clusters from the Meta-Catalog of X-ray detected Clusters of galaxies
(MCXC; $\langle z \rangle = 0.14$) at South Pole Telescope (SPT) and Sydney
University Molonglo Sky Survey (SUMSS) frequencies. Flux densities at 95, 150
and 220 GHz are extracted from the 2500 deg$^2$ SPT-SZ survey maps at the
locations of SUMSS sources, producing a multi-frequency catalog of radio
galaxies. In the direction of massive galaxy clusters, the radio galaxy flux
densities at 95 and 150 GHz are biased low by the cluster Sunyaev-Zel'dovich
Effect (SZE) signal, which is negative at these frequencies. We employ a
cluster SZE model to remove the expected flux bias and then study these
corrected source catalogs. We find that the high frequency radio galaxies are
centrally concentrated within the clusters and that their luminosity functions
(LFs) exhibit amplitudes that are characteristically an order of magnitude
lower than the cluster LF at 843 MHz. We use the 150 GHz LF to estimate the
impact of cluster radio galaxies on an SPT-SZ like survey. The radio galaxy
flux typically produces a small bias on the SZE signal and has negligible
impact on the observed scatter in the SZE mass-observable relation. If we
assume there is no redshift evolution in the radio galaxy LF then $1.8\pm0.7$
percent of the clusters would be lost from the sample. Allowing for redshift
evolution of the form $(1+z)^{2.5}$ increases the incompleteness to $5.6\pm1.0$
percent. Improved constraints on the evolution of the cluster radio galaxy LF
require a larger cluster sample extending to higher redshift.


title: The putative old, nearby cluster Lod\'{e}n 1 does not exist

abstract:
  Astronomers have access to precious few nearby, middle-aged benchmark star
clusters. Within 500 pc, there are only NGC 752 and Ruprecht 147 (R147), at 1.5
and 3 Gyr respectively. The Database for Galactic Open Clusters (WEBDA) also
lists Lod\'{e}n 1 as a 2 Gyr cluster at a distance of 360 pc. If this is true,
Lod\'{e}n 1 could become a useful benchmark cluster. This work details our
investigation of Lod\'{e}n 1. We assembled archival astrometry (PPMXL) and
photometry (2MASS, Tycho-2, APASS), and acquired medium resolution spectra for
radial velocity measurements with the Robert Stobie Spectrograph (RSS) at the
Southern African Large Telescope. We observed no sign of a cluster
main-sequence turnoff or red giant branch amongst all stars in the field
brighter than $J < 11$. Considering the 29 stars identified by L.O. Lod\'{e}n
and listed on SIMBAD as the members of Lod\'{e}n 1, we found no compelling
evidence of kinematic clustering in proper motion or radial velocity. Most of
these candidates are A stars and red giants, and their observed properties are
consistent with distant field stars in the direction of Lod\'{e}n 1 in the
Galactic plane. We conclude that the old nearby cluster Lod\'{e}n 1 is neither
old, nor nearby, nor a cluster.


title: Exocometary gas in the HD 181327 debris ring

abstract:
  An increasing number of observations have shown that gaseous debris discs are
not an exception. However, until now we only knew of cases around A stars. Here
we present the first detection of 12CO (2-1) disc emission around an F star, HD
181327, obtained with ALMA observations at 1.3 mm. The continuum and CO
emission are resolved into an axisymmetric disc with ring-like morphology.
Using a Markov chain Monte Carlo method coupled with radiative transfer
calculations we study the dust and CO mass distribution. We find the dust is
distributed in a ring with a radius of 86.0 +- 0.4 AU and a radial width of
23.2 +- 1.0 AU. At this frequency the ring radius is smaller than in the
optical, revealing grain size segregation expected due to radiation pressure.
We also report on the detection of low level continuum emission beyond the main
ring out to ~200 AU. We model the CO emission in the non-LTE regime and we find
that the CO is co-located with the dust, with a total CO gas mass ranging
between 1.2x10^-6 Mearth and 2.9x10^-6 Mearth, depending on the gas kinetic
temperature and collisional partners densities. The CO densities and location
suggest a secondary origin, i.e. released from icy planetesimals in the ring.
We derive a CO+CO2 cometary composition that is consistent with Solar system
comets. Due to the low gas densities it is unlikely that the gas is shaping the
dust distribution.


title: On Lithium-Rich Red Giants. I. Engulfment of Sub-Stellar Companions

abstract:
  A small fraction of red giants are known to be lithium (Li) rich, in
contradiction with expectations from stellar evolutionary theory. A possible
explanation for these atypical giants is the engulfment of a Li-rich planet or
brown dwarf by the star. In this work, we model the evolution of Li abundance
in canonical red giants including the accretion of a sub-stellar mass
companion. We consider a wide range of stellar and companion masses, Li
abundances, stellar metallicities, and planetary orbital periods. Based on our
calculations, companions with masses lower than 15 M_J dissolve in the
convective envelope and can induce Li enrichment in regimes where extra mixing
does not operate. Our models indicate that the accretion of a substellar
companion can explain abundances up to A(Li)~2.2, setting an upper limit for
Li-rich giants formed by this mechanism. Giants with higher abundances need
another mechanism to be explained. For reasonable planetary distributions, we
predict the Li abundance distribution of low-mass giants undergoing planet
engulfment, finding that between 1% to 3% of them should have A(Li)>1.5. We
show that depending on the stellar mass range, this traditional definition of
Li-rich giants is misleading, as isolated massive stars would be considered
anomalous while giants engulfing a companion would be set aside, flagged as
normal. We explore the detectability of companion engulfment, finding that
planets with masses higher than ~7 M_J produce a distinct signature, and that
descendants of stars originating in the Li-dip and low luminosity red giants
are ideal tests of this channel.


title: Time Delay Cosmography

abstract:
  Gravitational time delays, observed in strong lens systems where the variable
background source is multiply-imaged by a massive galaxy in the foreground,
provide direct measurements of cosmological distance that are very
complementary to other cosmographic probes. The success of the technique
depends on the availability and size of a suitable sample of lensed quasars or
supernovae, precise measurements of the time delays, accurate modeling of the
gravitational potential of the main deflector, and our ability to characterize
the distribution of mass along the line of sight to the source. We review the
progress made during the last 15 years, during which the first competitive
cosmological inferences with time delays were made, and look ahead to the
potential of significantly larger lens samples in the near future.


title: MCMC with Strings and Branes: The Suburban Algorithm (Extended Version)

abstract:
  Motivated by the physics of strings and branes, we develop a class of Markov
chain Monte Carlo (MCMC) algorithms involving extended objects. Starting from a
collection of parallel Metropolis-Hastings (MH) samplers, we place them on an
auxiliary grid, and couple them together via nearest neighbor interactions.
This leads to a class of "suburban samplers" (i.e., spread out Metropolis).
Coupling the samplers in this way modifies the mixing rate and speed of
convergence for the Markov chain, and can in many cases allow a sampler to more
easily overcome free energy barriers in a target distribution. We test these
general theoretical considerations by performing several numerical experiments.
For suburban samplers with a fluctuating grid topology, performance is strongly
correlated with the average number of neighbors. Increasing the average number
of neighbors above zero initially leads to an increase in performance, though
there is a critical connectivity with effective dimension d_eff ~ 1, above
which "groupthink" takes over, and the performance of the sampler declines.

categories: physics.comp-ph cond-mat.dis-nn hep-th stat.CO


title:
Variable Synaptic Strengths Controls the Firing Rate Distribution in
  Feedforward Neural Networks

abstract:
  Heterogeneity of firing rate statistics is known to have severe consequences
on neural coding. Recent experimental recordings in weakly electric fish
indicate that the distribution-width of superficial pyramidal cell firing rates
(trial- and time-averaged) in the electrosensory lateral line lobe (ELL)
depends on the stimulus, and also that network inputs can mediate changes in
the firing rate distribution across the population. We previously developed
theoretical methods to understand how two attributes (synaptic and intrinsic
heterogeneity) interact and alter the firing rate distribution in a population
of integrate-and-fire neurons with random recurrent coupling. Inspired by our
experimental data, we extend these theoretical results to a delayed feedforward
spiking network that qualitatively capture the changes of firing rate
heterogeneity observed in in-vivo recordings. We demonstrate how heterogeneous
neural attributes alter firing rate heterogeneity, accounting for the effect
with various sensory stimuli. The model predicts how the strength of the
effective network connectivity is related to intrinsic heterogeneity in such
delayed feedforward networks: the strength of the feedforward input is
positively correlated with excitability (threshold value for spiking) with low
firing rate heterogeneity and is negatively correlated with excitability with
high firing rate heterogeneity. We also show how our theory can be use to
predict effective neural architecture. We demonstrate that neural attributes do
not interact in a simple manner but rather in a complex stimulus-dependent
fashion to control neural heterogeneity and discuss how it can ultimately shape
population codes.


title:
Stable Interacting (2 + 1)d Conformal Field Theories at the Boundary of
  a class of (3 + 1)d Symmetry Protected Topological Phases

abstract:
  Motivated by recent studies of symmetry protected topological (SPT) phases,
we explore the possible gapless quantum disordered phases in the $(2+1)d$
nonlinear sigma model defined on the Grassmannian manifold
$\frac{U(N)}{U(n)\times U(N - n)}$ with a Wess-Zumino-Witten (WZW) term at
level $k$, which is the effective low energy field theory of the boundary of
certain $(3+1)d$ SPT states. With $k = 0$, this model has a well-controlled
large-$N$ limit, $i.e.$ its renormalization group equations can be computed
exactly with large-$N$. However, with the WZW term, the large-$N$ and large-$k$
limit alone is not sufficient for a reliable study of the nature of the quantum
disordered phase. We demonstrate that through a combined large-$N$, large-$k$
and $\epsilon-$generalization, a stable fixed point in the quantum disordered
phase can be reliably located in the large$-N$ limit and leading order
$\epsilon-$expansion, which corresponds to a $(2+1)d$ strongly interacting
conformal field theory.


title: Measurement of a Cosmographic Distance Ratio with Galaxy and CMB Lensing

abstract:
  We measure the gravitational lensing shear signal around dark matter halos
hosting CMASS galaxies using light sources at $z\sim 1$ (background galaxies)
and at the surface of last scattering at $z\sim 1100$ (the cosmic microwave
background). The galaxy shear measurement uses data from the CFHTLenS survey,
and the microwave background shear measurement uses data from the {\it Planck}
satellite. The ratio of shears from these cross-correlations provides a purely
geometric distance measurement across the longest possible cosmological lever
arm. This is because the matter distribution around the halos, including
uncertainties in galaxy bias and systematic errors such as miscentering,
cancels in the ratio for halos in thin redshift slices. We measure this
distance ratio in three different redshift slices of the CMASS sample, and
combine them to obtain a $17\%$ measurement of the distance ratio,
$r=0.390^{+0.070}_{-0.062}$ at an effective redshift of $z=0.53$. This is
consistent with the predicted ratio from the {\it Planck} best-fit $\Lambda$CDM
cosmology of $r=0.419$.


title:
At the survey limits: discovery of the Aquarius 2 dwarf galaxy in the
  VST ATLAS and the SDSS data

abstract:
  We announce the discovery of the Aquarius~2 dwarf galaxy, a new distant
satellite of the Milky Way, detected on the fringes of the VST ATLAS and the
SDSS surveys. The object was originally identified as an overdensity of Red
Giant Branch stars, but chosen for subsequent follow-up based on the presence
of a strong Blue Horizontal Branch, which was also used to measure its distance
of $\sim 110$ kpc. Using deeper imaging from the IMACS camera on the 6.5m Baade
and spectroscopy with DEIMOS on Keck, we measured the satellite's half-light
radius $5.1\pm 0.8$ arcmin, or $\sim 160$ pc at this distance, and its stellar
velocity dispersion of $5.4^{+3.4}_{-0.9}$ km s$^{-1}$. With $\mu=30.2$ mag
arcsec$^{-2}$ and $M_V=-4.36$, the new satellite lies close to two important
detection limits: one in surface brightness; and one in luminosity at a given
distance, thereby making Aquarius~2 one of the hardest dwarfs to find.


title:
Gradient-Based Estimation of Air Flow and Geometry Configurations in a
  Building Using Fluid Dynamic Adjoint Equations

abstract:
  Real-time estimations of temperature distributions and geometric
configurations are important to energy efficient buildings and the development
of smarter cities. In this paper we formulate a gradient-based estimation
algorithm capable of reconstructing the states of doors in a building, as well
as its temperature distribution, based on a floor plan and a set of
thermostats. Our algorithm solves in real time a convection-diffusion Computer
Fluid Dynamics (CFD) model for the air flow in the building as a function of
its geometric configuration. We formulate the estimation algorithm as an
optimization problem, and we solve it by computing the adjoint equations of our
CFD model, which we then use to obtain the gradients of the cost function with
respect to the flow's temperature and door states. We evaluate the performance
of our method using simulations of a real apartment in the St. Louis area. Our
results show that the estimation method is both efficient and accurate,
establishing its potential for the design of smarter control schemes in the
operation of high-performance buildings.


title: The Euler--Maxwell system for electrons: global solutions in $2D$

abstract:
  A basic model for describing plasma dynamics is given by the Euler-Maxwell
system, in which compressible ion and electron fluids interact with their own
self-consistent electromagnetic field. In this paper we consider the
"one-fluid" Euler--Maxwell model for electrons, in 2 spatial dimensions, and
prove global stability of a constant neutral background.


title: Observational strong gravity and quantum black hole structure

abstract:
  Quantum considerations have led many theorists to believe that classical
black hole physics is modified not just deep inside black holes but at {\it
horizon scales}, or even further outward. The near-horizon regime has just
begun to be observationally probed for astrophysical black holes -- both by
LIGO, and by the Event Horizon Telescope. This suggests exciting prospects for
observational constraints on or discovery of new quantum black hole structure.
This paper overviews arguments for certain such structure and these prospects.


title:
Improvement of algorithms to identify transportation modes for
  MobilitApp, an Android Application to anonymously track citizens in Barcelona

abstract:
  MobilitApp is an Android application whose objective is to obtain mobility
data from the citizens of the metropolitan area of Barcelona. The current
project is based on the research of more trustful and stronger transport
decision algorithms using advantages of accelerometry techniques. The developed
algorithm reads data from the mobile's accelerometer and gyroscope and writes
it in a file that is afterwards sent to the server. This process is executed in
background without interfering in the main application activity. Collected data
has been processed and used to analyze the behaviour of the mobility pattern of
the distinct transport modalities. The obtained result has been parameters
which allow us to configure a model for each mean activity and designing a
transport mode detection algorithm which would use information obtained from
the mobile's own sensors. MobilitApp is still executing its main functionality,
monitoring mobility data from the citizens. In future versions the solution
proposed to detect the transport systems will be integrated into the
application, in this way the app will work with information obtained from the
device and will not depend on any other services.


title: Top quark production at the LHC

abstract:
  Twenty years past its discovery, the top quark continues attracting great
interest as experiments keep unveiling its properties. An overview of the
latest measurements in the domain of top quark production, performed by the
ATLAS and CMS experiments at the CERN LHC, is given. The latest measurements of
top quark production rates via strong and electroweak processes are reported
and compared to different perturbative QCD predictions. Fundamental properties,
such as the mass or the couplings of the top quark, as well as
re-interpretations seeking for beyond the standard model contributions in the
top quark sector, are extracted from these measurements. In each case an
attempt to highlight the first results and main prospects for the on-going Run
2 of the LHC is made.


title: Suppression of two-bounce windows in kink-antikink collisions

abstract:
  We consider a class of topological defects in $(1,1)$-dimensions with a
deformed $\phi^4$ kink structure whose stability analysis leads to a
Schr\"odinger-like equation with a zero-mode and at least one vibrational
(shape) mode. We are interested in the dynamics of kink-antikink collisions,
focusing on the structure of two-bounce windows. For small deformation and for
one or two vibrational modes, the observed two-bounce windows are explained by
the standard mechanism of a resonant effect between the first vibrational and
the translational modes. With the increasing of the deformation, the effect of
the appearance of more than one vibrational mode is the gradual disappearance
of the initial two-bounce windows. The total suppression of two-bounce windows
even with the presence of a vibrational mode offers a counterexample from what
expected from the standard mechanism. For even larger deformation, some
two-bounce windows reappear, but with a non-standard structure.


title:
Treatment of gastric cancer cells with non-thermal atmospheric plasma
  generated in water

abstract:
  Non-thermal atmospheric plasma (NTAP) can be applied to living tissues and
cells as a novel technology for cancer therapy. Even though studies report on
the successful use of NTAP to directly irradiate cancer cells, this technology
can cause cell death only in the upper 3-5 cell layers. We report on a NTAP
argon solution generated in DI water for treating human gastric cancer cells
(NCl-N87). Our findings showed that the plasma generated in DI water during a
30-minute treatment had the strongest affect in inducing apoptosis in cultured
human gastric cancer cells. This result can be attributed to presence of
reactive oxygen species (ROS) and reactive nitrogen species (RNS) produced in
water during treatment. Furthermore, the data showed that elevated levels of
RNS may play an even more significant role than ROS in the rate of apoptosis in
gastric cancer cells.


title: A computation of modular forms of weight one and small level

abstract:
  We report on a computation of holomorphic cuspidal modular forms of weight
one and small level (currently level at most $1500$) and classification of them
according to the projective image of their attached Artin representations. The
data we have gathered, such as Fourier expansions and projective images of
Hecke newforms and dimensions of space of forms, is available in both Magma and
\texttt{Sage} readable formats on a webpage created in support of this ongoing
project. We explain some of the novel aspects of these computations and what
they have uncovered.


title: Dual QED3 at "NF = 1/2" is an interacting CFT in the infrared

abstract:
  We study the fate of weakly coupled dual QED3 in the infrared, that is, a
single two-component Dirac fermion coupled to an emergent U(1) gauge field, but
without Chern-Simons term. This theory has recently been proposed as a dual
description of 2D surfaces of certain topological insulators. Using the
renormalization group, we find that the interplay of gauge fluctuations with
generated interactions in the four-fermi sector stabilizes an interacting
conformal field theory (CFT) with finite four-fermi coupling in the infrared.
The emergence of this CFT is due to cancellations in the $\beta$-function of
the four-fermi coupling special to "NF = 1/2". We also quantify how a possible
"strong" Dirac fermion duality between a free Dirac cone and dual QED3 would
constrain the universal constants of the topological current correlator of the
latter.


title:
Programmable Potentials: Approximate N-body potentials from coarse-level
  logic

abstract:
  This paper gives a systematic method for constructing an N-body potential,
approximating the true potential, that accurately captures meso-scale behavior
of the chemical or biological system using pairwise potentials coming from
experimental data or ab initio methods. The meso-scale behavior is translated
into logic rules for the dynamics. Each pairwise potential has an associated
logic function that is constructed using the logic rules, a class of elementary
logic functions, and AND, OR, and NOT gates. The effect of each logic function
is to turn its associated potential on and off. The N-body potential is
constructed as linear combination of the pairwise potentials, where the
"coefficients" of the potentials are smoothed versions of the associated logic
functions. These potentials allow a potentially low-dimensional description of
complex processes while still accurately capturing the relevant physics at the
meso-scale. We present the proposed formalism to construct coarse-grained
potential models for three examples: an inhibitor molecular system, bond
breaking in chemical reactions, and DNA transcription from biology. The method
can potentially be used in reverse for design of molecular processes by
specifying properties of molecules that can carry them out.


title:
Orthogonal symmetric non-negative matrix factorization under the
  stochastic block model

abstract:
  We present a method based on the orthogonal symmetric non-negative matrix
tri-factorization of the normalized Laplacian matrix for community detection in
complex networks. While the exact factorization of a given order may not exist
and is NP hard to compute, we obtain an approximate factorization by solving an
optimization problem. We establish the connection of the factors obtained
through the factorization to a non-negative basis of an invariant subspace of
the estimated matrix, drawing parallel with the spectral clustering. Using such
factorization for clustering in networks is motivated by analyzing a
block-diagonal Laplacian matrix with the blocks representing the connected
components of a graph. The method is shown to be consistent for community
detection in graphs generated from the stochastic block model and the degree
corrected stochastic block model. Simulation results and real data analysis
show the effectiveness of these methods under a wide variety of situations,
including sparse and highly heterogeneous graphs where the usual spectral
clustering is known to fail. Our method also performs better than the state of
the art in popular benchmark network datasets, e.g., the political web blogs
and the karate club data.


title:
A Monte Carlo method for critical systems in infinite volume: the planar
  Ising model

abstract:
  In this paper we propose a Monte Carlo method for generating finite-domain
marginals of critical distributions of statistical models in infinite volume.
The algorithm corrects the problem of the long-range effects of boundaries
associated to generating critical distributions on finite lattices. It uses the
advantage of scale invariance combined with ideas of the renormalization group
in order to construct a type of "holographic" boundary condition that encodes
the presence of an infinite volume beyond it. We check the quality of the
distribution obtained in the case of the planar Ising model by comparing
various observables with their infinite-plane prediction. We accurately
reproduce planar two-, three- and four-point functions of spin and energy
operators. We also define a lattice stress-energy tensor, and numerically
obtain the associated conformal Ward identities and the Ising central charge.


title:
The Problem of Projecting the Origin of Euclidean Space onto the Convex
  Polyhedron

abstract:
  This paper is aimed at presenting a systematic survey of the existing now
different formulations for the problem of projection of the origin of the
Euclidean space onto the convex polyhedron (PPOCP). In the present paper, there
are investigated the reduction of the projection program to the problems of
quadratic programming, maximin, linear complementarity, and nonnegative least
squares. Such reduction justifies the opportunity of utilizing a much more
broad spectrum of powerful tools of mathematical programming for solving PPOCP.
  The paper's goal is to draw the attention of a wide range of research at the
different formulations of the projection problem, which remain largely unknown
due to the fact that the papers (addressing the subject of concern) are
published even though on the adjacent, but other topics, or only in the
conference proceedings.


title:
Linear redshift space distortions for cosmic voids based on galaxies in
  redshift space

abstract:
  Cosmic voids found in galaxy surveys are defined based on the galaxy
distribution in redshift space. We show that the large scale distribution of
voids in redshift space traces the fluctuations in the dark matter density
field \delta(k) (in Fourier space with \mu being the line of sight projected
k-vector): \delta_v^s(k) = (1 + \beta_v \mu^2) b^s_v \delta(k), with a beta
factor that will be in general different than the one describing the
distribution of galaxies. Only in case voids could be assumed to be quasi-local
transformations of the linear (Gaussian) galaxy redshift space field, one gets
equal beta factors \beta_v=\beta_g=f/b_g with f being the growth rate, and b_g,
b^s_v being the galaxy and void bias on large scales defined in redshift space.
Indeed, in our mock void catalogs we measure void beta factors being in good
agreement with the galaxy one. Further work needs to be done to confirm the
level of accuracy of the beta factor equality between voids and galaxies, but
in general the void beta factor needs to be considered as a free parameter for
RSD studies.


title:
Hardware Based Projection onto The Parity Polytope and Probability
  Simplex

abstract:
  This paper is concerned with the adaptation to hardware of methods for
Euclidean norm projections onto the parity polytope and probability simplex. We
first refine recent efforts to develop efficient methods of projection onto the
parity polytope. Our resulting algorithm can be configured to have either
average computational complexity $\mathcal{O}\left(d\right)$ or worst case
complexity $\mathcal{O}\left(d\log{d}\right)$ on a serial processor where $d$
is the dimension of projection space. We show how to adapt our projection
routine to hardware. Our projection method uses a sub-routine that involves
another Euclidean projection; onto the probability simplex. We therefore
explain how to adapt to hardware a well know simplex projection algorithm. The
hardware implementations of both projection algorithms achieve area scalings of
$\mathcal{O}(d\left(\log{d}\right)^2)$ at a delay of
$\mathcal{O}(\left(\log{d}\right)^2)$. Finally, we present numerical results in
which we evaluate the fixed-point accuracy and resource scaling of these
algorithms when targeting a modern FPGA.


title: One-sided almost specification and intrinsic ergodicity

abstract:
  Shift spaces with the specification property are intrinsically ergodic, i.e.
they have a unique measure of maximal entropy. This can fail for shifts with
the weaker almost specification property. We define a new property called
one-sided almost specification, which lies in between specification and almost
specification, and prove that it guarantees intrinsic ergodicity if the
corresponding mistake function g is bounded. We also show that uniqueness may
fail for unbounded g such as log log n. Our results have consequences for
almost specification: we prove that almost specification with g=1 implies
one-sided almost specification (with g=1), and hence uniqueness. On the other
hand, the second author showed recently that almost specification with g=4 does
not imply uniqueness. This leaves open the question of whether almost
specification implies intrinsic ergodicity when g=2 or g=3.