title:
On the Theoretical Framework of Magnetized Outflows from Stellar-Mass
  Black Holes and Related Observations

abstract:
  The spins of stellar-mass black holes (BHs) and the power outputs of their
jets are measurable quantities. Unfortunately, the currently employed methods
do not agree and the results are controversial. Two major issues concern the
measurements of BH spin and beam (jet) power. The former issue can be resolved
by future observations. But the latter issue can be resolved now, if we pay
attention to what is expected from theoretical considerations. The question of
whether a correlation has been found between the power outputs of few objects
and the spins of their BHs is moot because BH beam power does not scale with
the square of the spin of the BH. We show that the theoretical BH beam power is
a strongly nonlinear function of spin that cannot be approximated by a
quadratic relation, as is generally stated when the influence of the magnetic
field is not accounted for in the \cite{bla77} model. The BH beam power of
ballistic jets should scale a lot more steeply with BH spin irrespective of the
magnetic field assumed to thread the horizon and the spin range considered.
This behavior may already be visible in the analyses of radio observations by
\cite{nar12} and \cite{rus13}. In agreement with previous studies, we also find
that the power output that originates in the inner regions of the surrounding
accretion disks is higher than that from the BHs and it cannot be ignored in
investigations of continuous compact jets from these systems.


title: Topological phases from higher gauge symmetry in 3+1D

abstract:
  We propose an exactly solvable Hamiltonian for topological phases in $3+1$
dimensions utilising ideas from higher lattice gauge theory, where the gauge
symmetry is given by a finite 2-group. We explicitly show that the model is a
Hamiltonian realisation of Yetter's homotopy 2-type topological quantum field
theory whereby the groundstate projector of the model defined on the manifold
$M^3$ is given by the partition function of the underlying topological quantum
field theory for $M^3\times [0,1]$. We show that this result holds in any
dimension and illustrate it by computing the ground state degeneracy for a
selection of spatial manifolds and 2-groups. As an application we show that a
subset of our model is dual to a class of Abelian Walker-Wang models describing
$3+1$ dimensional topological insulators.


title:
Neural Morphological Tagging from Characters for Morphologically Rich
  Languages

abstract:
  This paper investigates neural character-based morphological tagging for
languages with complex morphology and large tag sets. We systematically explore
a variety of neural architectures (DNN, CNN, CNNHighway, LSTM, BLSTM) to obtain
character-based word vectors combined with bidirectional LSTMs to model
across-word context in an end-to-end setting. We explore supplementary use of
word-based vectors trained on large amounts of unlabeled data. Our experiments
for morphological tagging suggest that for "simple" model configurations, the
choice of the network architecture (CNN vs. CNNHighway vs. LSTM vs. BLSTM) or
the augmentation with pre-trained word embeddings can be important and clearly
impact the accuracy. Increasing the model capacity by adding depth, for
example, and carefully optimizing the neural networks can lead to substantial
improvements, and the differences in accuracy (but not training time) become
much smaller or even negligible. Overall, our best morphological taggers for
German and Czech outperform the best results reported in the literature by a
large margin.


title:
Impurity invisibility in graphene: Symmetry guidelines for the design of
  efficient sensors

abstract:
  Renowned for its sensitivity to detect the presence of numerous substances,
graphene is an excellent chemical sensor. Unfortunately, which general features
a dopant must have in order to enter the list of substances detectable by
graphene are not exactly known. Here we demonstrate with a simple model
calculation implemented in three different ways that one of such features is
the symmetry properties of the impurity binding to graphene. In particular, we
show that electronic scattering is suppressed when dopants are bound
symmetrically to both graphene sub-lattices, giving rise to impurity
invisibility. In contrast, dopants that affect the two sublattices
asymmetrically are more strongly scattered and therefore the most likely
candidates to being chemically sensed by graphene. Furthermore, we demonstrate
that impurity invisibility is lifted with the introduction of a
symmetry-breaking perturbation such as uniaxial strain. In this case, graphene
with sublattice-symmetric dopants will function as efficient strain sensors. We
argue that by classifying dopants through their bonding symmetry leads to a
more efficient way of identifying suitable components for graphene-based
sensors.


title:
Particle production and equilibrium properties within a new hadron
  transport approach for heavy-ion collisions

abstract:
  The microscopic description of heavy-ion reactions at low beam energies is
achieved within hadronic transport approaches. In this article a new approach
SMASH (Simulating Many Accelerated Strongly-interacting Hadrons) is introduced
and applied to study the production of non-strange particles in heavy-ion
reactions at $E_{\rm kin}=0.4-2A$ GeV. First, the model is described including
details about the collision criterion, the initial conditions and the resonance
formation and decays. To validate the approach, equilibrium properties such as
detailed balance are presented and the results are compared to experimental
data for elementary cross sections. Finally results for pion and proton
production in C+C and Au+Au collisions is confronted with HADES and FOPI data.
Predictions for particle production in $\pi+A$ collisions are made.


title: Supersymmetric black lenses in five dimensions

abstract:
  We present an asymptotically flat supersymmetric black lens solution with the
horizon topology L(n,1)=S^3/Z_n in the five-dimensional minimal ungauged
supergravity. We show that the black lens carries a mass, two independent
angular momenta, electric charge and (n-1) magnetic fluxes, among which only
the (n+1) quantities are independent.


title: How DNA Cryptography can help whistleblowers and refugees

abstract:
  The recent progress in DNA sequencing will probably revolutionize the world
of electronic. Hence, we went from DNA sequencing that only research centers
could realize, to portable, tiny and inexpensive tools. So, it is likely that
in a few years these DNA sequencers will be included in our smartphones.
  The purpose of this paper is to support this revolution, by using the DNA
cryptography, hash functions and social networks. The first application will
introduce a mutual entity authentication protocol in order to help waifs,
refugees, and victims of human trafficking to find their biological parents
online.
  The second application will also use the DNA cryptography and the social
networks to protect whistleblowers' actions. For example, this method will
allow whistleblowers to securely broadcast on social networks, their
information with one grape.


title: Sensitivity to Serial Dependency of Input Processes: A Robust Approach

abstract:
  Procedures in assessing the impact of serial dependency on performance
analysis are usually built on parametrically specified models. In this paper,
we propose a robust, nonparametric approach to carry out this assessment, by
computing the worst-case deviation of the performance measure due to arbitrary
dependence. The approach is based on optimizations, posited on the model space,
that have constraints specifying the level of dependency measured by a
nonparametric distance to some nominal i.i.d. input model. We study
approximation methods for these optimizations via simulation and
analysis-of-variance (ANOVA). Numerical experiments demonstrate how the
proposed approach can discover the hidden impacts of dependency beyond those
revealed by conventional parametric modeling and correlation studies.


title:
Photon-initiated production of a di-lepton final state at the LHC: cross
  section versus forward-backward asymmetry studies

abstract:
  We explore the effects of Photon Induced (PI) production of a dilepton final
state in the Large Hadron Collider environment. Using QED Parton Distribution
Function (PDF) sets we can treat the photons as real partons inside the protons
and compare their yield directly to that of the Drell-Yan (DY) process. In
particular, we concentrate on an error analysis of the two mechanisms. In order
to do so, we use the NNPDF set, which comes with a set of replicas to estimate
the systematic PDF error. On the one hand, we find that the PI contribution
becomes dominant over DY above a dilepton invariant mass of 3 TeV. On the other
hand, the PI predictions are affected by a large error coming from the QED
PDFs, well above the one affecting the DY mode. We assess the impact of these
uncertainties in the context of resonant and non-resonant searches for a
neutral massive vector boson (Z') through the differential cross section and
Forward-Backward Asymmetry (AFB) observables as a function of the dilepton
invariant mass. While the former is subject to the aforementioned significant
residual errors the latter shows the systematic error cancellation expected
(recall that AFB is a ratio of cross sections) even in presence of PI
contributions, so that the recently emphasized key role played by AFB as a
valid tool for both Z' discovery and interpretation in both resonant and
non-resonant mode is further consolidated.


title: A few comments to a method for producing positrons for ILC

abstract:
  We attracted attention to some peculiarities of positron production for
linear collider (ILC). The conversion system with many targets and low K-factor
is our primary interest.


title: A dynamical adaptive tensor method for the Vlasov-Poisson system

abstract:
  A numerical method is proposed to solve the full-Eulerian time-dependent
Vlasov-Poisson system in high dimension. The algorithm relies on the
construction of a tensor decomposition of the solution whose rank is adapted at
each time step. This decomposition is obtained through the use of an efficient
modified Progressive Generalized Decomposition (PGD) method, whose convergence
is proved. We suggest in addition a symplectic time-discretization splitting
scheme that preserves the Hamiltonian properties of the system. This scheme is
naturally obtained by considering the tensor structure of the approximation.
The efficiency of our approach is illustrated through time-dependent 2D-2D
numerical examples.


title:
Mobility induced unsaturated high linear magnetoresistance in
  transition-metal monopnictides Weyl semimetals

abstract:
  Discovery of Weyl fermions in semimetallic tansition-metal monopnictides is a
major breakthrough in condensed matter physics. A Weyl semimetal is
characterized by the existence of robust Weyl points and unclosed topological
surface states in the form of Fermi arc. All the four compounds of the Weyl
semimetal transition monopnictide family i.e. NbP, TaP, NbAs and TaAs exhibit
extremely high mobility and unsaturated high magnetoresistance (MR). For
example, MR values are 8.5x10^5% at 1.85 K for NbP and 1.5x10^5% at 3 K in 9 T
for TaAs. NbP also achieves very low value of residual resistivity 0.63
micro-ohm cm at 2 K due to suppression of scattering resulting in ultra-high
mobility 5x10^6 cm^2/Vs, Interestingly, we find that the mobility of these
compounds play an important role for such a large MR.


title: 3D U-Net: Learning Dense Volumetric Segmentation from Sparse Annotation

abstract:
  This paper introduces a network for volumetric segmentation that learns from
sparsely annotated volumetric images. We outline two attractive use cases of
this method: (1) In a semi-automated setup, the user annotates some slices in
the volume to be segmented. The network learns from these sparse annotations
and provides a dense 3D segmentation. (2) In a fully-automated setup, we assume
that a representative, sparsely annotated training set exists. Trained on this
data set, the network densely segments new volumetric images. The proposed
network extends the previous u-net architecture from Ronneberger et al. by
replacing all 2D operations with their 3D counterparts. The implementation
performs on-the-fly elastic deformations for efficient data augmentation during
training. It is trained end-to-end from scratch, i.e., no pre-trained network
is required. We test the performance of the proposed method on a complex,
highly variable 3D structure, the Xenopus kidney, and achieve good results for
both use cases.


title: Franckeite: a naturally occurring van der Waals heterostructure

abstract:
  The fabrication of van der Waals heterostructures, artificial materials
assembled by individually stacking atomically thin (2D) materials, is one of
the most promising directions in 2D materials research. Until now, the most
widespread approach to stack 2D layers relies on deterministic placement
methods which are cumbersome when fabricating multilayered stacks. Moreover,
they tend to suffer from poor control over the lattice orientations and the
presence of unwanted adsorbates between the stacked layers. Here, we present a
different approach to fabricate ultrathin heterostructures by exfoliation of
bulk franckeite which is a naturally occurring and air stable van der Waals
heterostructure (composed of alternating SnS2-like and PbS-like layers stacked
on top of each other). Presenting both an attractive narrow bandgap (<0.7 eV)
and p-type doping, we find that the material can be exfoliated both
mechanically and chemically down to few-layer thicknesses. We present extensive
theoretical and experimental characterizations of the material's electronic
properties and crystal structure, and explore applications for near-infrared
photodetectors (exploiting its narrow bandgap) and for p-n junctions based on
the stacking of MoS2 (n-doped) and franckeite (p-doped)


title: Lifting of the Vlasov-Maxwell Bracket by Lie-transform Method

abstract:
  The Vlasov-Maxwell equations possess a Hamiltonian structure expressed in
terms of a Hamiltonian functional and a functional bracket. In the present
paper, the transformation ("lift") of the Vlasov-Maxwell bracket induced by the
dynamical reduction of single-particle dynamics is investigated when the
reduction is carried out by Lie-transform perturbation methods. The ultimate
goal of this work is to derive explicit Hamiltonian formulations for the
guiding-center and gyrokinetic Vlasov-Maxwell equations that have important
applications in our understanding of turbulent magnetized plasmas. Here, it is
shown that the general form of the reduced Vlasov-Maxwell equations possesses a
Hamiltonian structure defined in terms of a reduced Hamiltonian functional and
a reduced bracket that automatically satisfies the standard bracket properties.


title: Tracking Time-Vertex Propagation using Dynamic Graph Wavelets

abstract:
  Graph Signal Processing generalizes classical signal processing to signal or
data indexed by the vertices of a weighted graph. So far, the research efforts
have been focused on static graph signals. However numerous applications
involve graph signals evolving in time, such as spreading or propagation of
waves on a network. The analysis of this type of data requires a new set of
methods that fully takes into account the time and graph dimensions. We propose
a novel class of wavelet frames named Dynamic Graph Wavelets, whose time-vertex
evolution follows a dynamic process. We demonstrate that this set of functions
can be combined with sparsity based approaches such as compressive sensing to
reveal information on the dynamic processes occurring on a graph. Experiments
on real seismological data show the efficiency of the technique, allowing to
estimate the epicenter of earthquake events recorded by a seismic network.


title: Characterizing HR3549B using SPHERE

abstract:
  Aims. In this work, we characterize the low mass companion of the A0 field
star HR3549. Methods. We observed HR3549AB in imaging mode with the the NIR
branch (IFS and IRDIS) of SPHERE@VLT, with IFS in YJ mode and IRDIS in the H
band. We also acquired a medium resolution spectrum with the IRDIS long slit
spectroscopy mode. The data were reduced using the dedicated SPHERE GTO
pipeline, purposely designed for this instrument. We employed algorithms such
as PCA and TLOCI to reduce the speckle noise. Results. The companion was
clearly visible both with IRDIS and IFS.We obtained photometry in four
different bands as well as the astrometric position for the companion. Based on
our astrometry, we confirm that it is a bound object and put constraints on its
orbit. Although several uncertainties are still present, we estimate an age of
~100-150 Myr for this system, yielding a most probable mass for the companion
of 40-50MJup and T_eff ~300-2400 K. Comparing with template spectra points to a
spectral type between M9 and L0 for the companion, commensurate with its
position on the color-magnitude diagram.


title: Stochastic Burgers equation from long range exclusion interactions

abstract:
  We consider one-dimensional exclusion processes with long jumps given by a
transition probability of the form $p_n(\cdot)=s(\cdot)+\gamma_na(\cdot)$, such
that its symmetric part $s(\cdot)$ is irreducible with finite variance and its
antisymmetric part is absolutely bounded by $s(\cdot).$ We prove that under
diffusive time scaling and strength of asymmetry $\sqrt n \gamma_n
\to_{n\to\infty} b\neq 0$, the equilibrium density fluctuations are given by
the unique energy solution of the stochastic Burgers equation.


title: Quantum Estimation Methods for Quantum Illumination

abstract:
  Quantum illumination consists in shining quantum light on a target region
immersed in a bright thermal bath, with the aim of detecting the presence of a
possible low-reflective object. If the signal is entangled with the receiver,
then a suitable choice of the measurement offers a gain with respect to the
optimal classical protocol employing coherent states. Here, we tackle this
detection problem by using quantum estimation techniques to measure the
reflectivity parameter of the object, showing an enhancement in the
signal-to-noise ratio up to 3 dB with respect to the classical case when
implementing only local measurements. Our approach employs the quantum Fisher
information to provide an upper bound for the error probability, supplies the
concrete estimator saturating the bound, and extends the quantum illumination
protocol to non-Gaussian states. As an example, we show how Schrodinger's cat
states may be used for quantum illumination.


title: A p-Laplacian supercritical Neumann problem

abstract:
  For $p>2$, we consider the quasilinear equation $-\Delta_p u+|u|^{p-2}u=g(u)$
in the unit ball $B$ of $\mathbb R^N$, with homogeneous Neumann boundary
conditions. The assumptions on $g$ are very mild and allow the nonlinearity to
be possibly supercritical in the sense of Sobolev embeddings. We prove the
existence of a nonconstant, positive, radially nondecreasing solution via
variational methods. In the case $g(u)=|u|^{q-2}u$, we detect the asymptotic
behavior of these solutions as $q\to\infty$.


title: On the Quasi-Stationary Distribution of the Shiryaev-Roberts Diffusion

abstract:
  We consider the diffusion $(R_t^r)_{t\ge0}$ generated by the equation
$dR_t^r=dt+\mu R_t^r dB_t$ with $R_0^r\triangleq r\ge0$ fixed, and where
$\mu\neq0$ is given, and $(B_t)_{t\ge0}$ is standard Brownian motion. We assume
that $(R_t^r)_{t\ge0}$ is stopped at
$\mathcal{S}_A^r\triangleq\inf\{t\ge0\colon R_t^r=A\}$ with $A>0$ preset, and
obtain a closed-from formula for the quasi-stationary distribution of
$(R_t^r)_{t\ge0}$, i.e., the limit
$Q_A(x)\triangleq\lim_{t\to+\infty}\Pr(R_t^r\le x|\mathcal{S}_A^r>t)$,
$x\in[0,A]$. Further, we also prove $Q_A(x)$ to be unimodal for any $A>0$, and
obtain its entire moment series. More importantly, the pair
$(\mathcal{S}_A^r,R_t^r)$ with $r\ge0$ and $A>0$ is the well-known Generalized
Shiryaev-Roberts change-point detection procedure, and its characteristics for
$r\sim Q_A(x)$ are of particular interest, especially when $A>0$ is large. In
view of this circumstance we offer an order-three large-$A$ asymptotic
approximation of $Q_A(x)$ valid for all $x\in[0,A]$. The approximation is
rather accurate even if $A$ is lower than what would be considered "large" in
practice.


title:
A fully Bayesian strategy for high-dimensional hierarchical modeling
  using massively parallel computing

abstract:
  Markov chain Monte Carlo (MCMC) is the predominant tool used in Bayesian
parameter estimation for hierarchical models. When the model expands due to an
increasing number of hierarchical levels, number of groups at a particular
level, or number of observations in each group, a fully Bayesian analysis via
MCMC can easily become computationally demanding, even intractable. We
illustrate how the steps in an MCMC for hierarchical models are predominantly
one of two types: conditionally independent draws or low-dimensional draws
based on summary statistics of parameters at higher levels of the hierarchy.
Parallel computing can increase efficiency by performing embarrassingly
parallel computations for conditionally independent draws and calculating the
summary statistics using parallel reductions. During the MCMC algorithm, we
record running means and means of squared parameter values to allow convergence
diagnosis and posterior inference while avoiding the costly memory transfer
bottleneck. We demonstrate the effectiveness of the algorithm on a model
motivated by next generation sequencing data, and we release our implementation
in R packages fbseq and fbseqCUDA.


title: Mapping polygons to the grid with small Hausdorff and Fr\'echet distance

abstract:
  We show how to represent a simple polygon $P$ by a grid (pixel-based) polygon
$Q$ that is simple and whose Hausdorff or Fr\'echet distance to $P$ is small.
For any simple polygon $P$, a grid polygon exists with constant Hausdorff
distance between their boundaries and their interiors. Moreover, we show that
with a realistic input assumption we can also realize constant Fr\'echet
distance between the boundaries. We present algorithms accompanying these
constructions, heuristics to improve their output while keeping the distance
bounds, and experiments to assess the output.


title: Coherent Processing of a Qubit Using One Squeezed State

abstract:
  We use a single squeezed state to represent a qubit, which can be coherently
processed in a deconvolution picture (DP) in the presence of noise. We avail
ourselves of the fact that when evolution is governed by a quadratic
dissipative equation, there exists a basis of squeezed states that evolves to
another basis of such states in the DP. An operator acts as an impurity filter,
restoring the coherence lost from the inexorable interactions of the qubit with
its surroundings.


title:
Strict lower bounds with separation of sources of error in
  non-overlapping domain decomposition methods

abstract:
  This article deals with the computation of guaranteed lower bounds of the
error in the framework of finite element (FE) and domain decomposition (DD)
methods. In addition to a fully parallel computation, the proposed lower bounds
separate the algebraic error (due to the use of a DD iterative solver) from the
discretization error (due to the FE), which enables the steering of the
iterative solver by the discretization error. These lower bounds are also used
to improve the goal-oriented error estimation in a substructured context.
Assessments on 2D static linear mechanic problems illustrate the relevance of
the separation of sources of error and the lower bounds' independence from the
substructuring. We also steer the iterative solver by an objective of precision
on a quantity of interest. This strategy consists in a sequence of solvings and
takes advantage of adaptive remeshing and recycling of search directions.


title: Contraction of graphs and spanning k-end trees

abstract:
  A tree with at most k leaves is called k-ended tree, and a tree with exactly
k leaves is called k-end tree, where a leaf is a vertex of degree one.
Contraction of a graph G along the edge e means deleting the edge e and
identifying its end vertices and deleting all edges between every two vertex
except one edge to gain again a simple graph and is denoted bye G/e. In this
paper we prove some theorems related to a graph and its contraction. For
example we prove the following theorem. If G is a connected graph that has a
spanning k-end tree and |V (G)| > K + 1 then there exist an edge e such G/e has
a spanning k-end tree.


title:
Inequity Aversion Pricing over Social Networks: Approximation Algorithms
  and Hardness Results

abstract:
  We study a revenue maximization problem in the context of social networks.
Namely, we consider a model introduced by Alon, Mansour, and Tennenholtz (EC
2013) that captures inequity aversion, i.e., prices offered to neighboring
vertices should not be significantly different. We first provide approximation
algorithms for a natural class of instances, referred to as the class of
single-value revenue functions. Our results improve on the current state of the
art, especially when the number of distinct prices is small. This applies, for
example, to settings where the seller will only consider a fixed number of
discount types or special offers. We then resolve one of the open questions
posed in Alon et al., by establishing APX-hardness for the problem.
Surprisingly, we further show that the problem is NP-complete even when the
price differences are allowed to be large, or even when the number of allowed
distinct prices is as small as three. Finally, we provide some extensions of
the model, regarding either the allowed set of prices or the demand type of the
clients.


title:
$P$-wave coupled-channel scattering of $B_s\pi,\,B_s^*\pi,\,B\overline
  K,\,B^{*}\overline K$ and the puzzling $X(5568)$

abstract:
  The D0 Collaboration has recently reported a narrow peak structure in the
$B_s^0\pi^\pm$ invariant-mass spectrum, that is called $X(5568)$. Its proposed
quantum numbers $J^P=0^+/1^+$ are not determined unambiguously, and we show
that one can fit the data assuming $J^P=1^-$ with the same mass and width for
the resonance signal. The corresponding isovector $P$-wave coupled-channel
scattering involving the states $B_s\pi$, $B_s^*\pi$, $B \overline{K}$ and
$B^*\overline K$ is studied employing leading-order Heavy Meson Chiral
Perturbation Theory, which is then unitarized making use of standard techniques
from Unitary Chiral Perturbation Theory. The subtraction constants that appear
in the unitarization process are determined by a $u$-channel crossing symmetry
constraint or by naturalness arguments, being the numerical values obtained in
both cases quite closed, and no further freedom is left in the model. A crucial
point is that if the $X(5568)$ is $1^-$ and decaying into $B_s^0\pi^\pm$ then
it should appear as a pole in the $T$-matrix elements. It finally turns out
that no $X(5568)$ pole is found that can be qualified as dynamically generated
from the isovector $P$-wave coupled-channel dynamics. This result disfavors the
interpretation of the $X(5568)$ within a "molecular" picture.


title:
Matrix Formalism of Excursion Set Theory: A new approach to statistics
  of dark matter halo counting

abstract:
  Excursion set theory (EST) is an analytical framework to study the
large-scale structure of the Universe. EST introduces a procedure to calculate
the number density of structures by relating the cosmological linear
perturbation theory to the nonlinear structures in late time. In this work, we
introduce a novel approach to reformulate the EST in matrix formalism. We
propose that the matrix representation of EST will facilitate the calculations
in this framework. The method is to discretize the two-dimensional plane of
variance and density contrast of EST, where the trajectories for each point in
the Universe lived there. The probability of having a density contrast in a
chosen variance is represented by a probability ket. Naturally, the concept of
the transition matrix pops up to define the trajectories. We also define the
probability transition rate which is used to obtain the first up-crossing of
trajectories and the number count of the structures. In this work we show that
the discretization let us study the non-Markov processes by forcing them to
look like a Wiener process. Also we discuss that the zero drift processes with
Gaussian and also non-Gaussian initial conditions can be studied by this
formalism. The continuous limit of the formalism is discussed, and the known
Fokker-Planck dispersion equation is recovered. Finally we show that the
probability of the most massive progenitors can be extracted in this framework.


title:
Viscoelasticity of model surfactant solutions determined by rotational
  magnetic spectroscopy

abstract:
  Being able to reduce the size of a rheometer down to the micron scale is a
unique opportunity to explore the mechanical response of expensive and/or
confined liquids and gels. To this aim, we synthesize micron size wires with
magnetic properties and examine the possibility of using them as microrheology
probes. In this work, we exploit the technique of rotational magnetic
spectroscopy by placing a wire in a rotating magnetic field and monitor its
temporal evolution by time-lapse microscopy. The wire-based microrheology
technique is tested on wormlike micellar surfactant solutions showing very
different relaxation dynamics and viscosities. A model for the wire rotation is
also developed and used to predict the wire behavior. It is shown that the
rheological parameters of the surfactant solutions including the static shear
viscosity, the entangled micellar network relaxation time and the elastic
modulus are in good agreement with those of conventional rheometry.


title:
Competitive binding of transcription factors drives Mendelian dominance
  in regulatory genetic pathways

abstract:
  We report a new mechanism for allelic dominance in regulatory genetic
interactions that we call binding dominance. We investigated a biophysical
model of gene regulation, where the fractional occupancy of a transcription
factor (TF) on the cis-regulated promoter site it binds to is determined by
binding energy (-{\Delta}G) and TF dosage. Transcription and gene expression
proceed when the TF is bound to the promoter. In diploids, individuals may be
heterozygous at the cis-site, at the TF's coding region, or at the TF's own
promoter, which determines allele-specific dosage. We find that when the TF's
coding region is heterozygous, TF alleles compete for occupancy at the cis
sites and the tighter-binding TF is dominant in proportion to the difference in
binding strength. When the TF's own promoter is heterozygous, the TF produced
at the higher dosage is also dominant. Cis-site heterozygotes have additive
expression and therefore codominant phenotypes. Binding dominance propagates to
affect the expression of downstream loci and it is sensitive in both magnitude
and direction to genetic background, but its detectability often attenuates.
While binding dominance is inevitable at the molecular level, it is difficult
to detect in the phenotype under some biophysical conditions, more so when TF
dosage is high and allele-specific binding affinities are similar. A body of
empirical research on the biophysics of TF binding demonstrates the
plausibility of this mechanism of dominance, but studies of gene expression
under competitive binding in heterozygotes in a diversity of genetic
backgrounds are needed.


title: Bad-Metal Relaxation Dynamics in a Fermi Lattice Gas

abstract:
  We report the discovery of phenomena consistent with bad-metal relaxation
dynamics in the metallic regime of an optical-lattice Hubbard model. The
transport lifetime induced by inter-particle scattering for a mass current of
atoms excited by stimulated Raman transitions is measured, and the
corresponding analog of resistivity is inferred. By exploring a range of
temperature, we demonstrate incompatibility with weak-scattering theory and a
key characteristic of bad metals: anomalous resistivity scaling consistent with
$T$-linear behavior. We also observe the onset of two behaviors---incoherent
transport and the approach to the Mott-Ioffe-Regel limit---associated with bad
metals. The interaction and temperature scaling of resistivity are verified to
be consistent with dynamic mean-field theory (DMFT) predictions of a bad metal,
which is associated with the reduction of quasiparticle weight by strong
interactions.


title: Simplified QCD fit method for BSM analysis of HERA data

abstract:
  The high-precision HERA data can be used as an input to a QCD analysis within
the DGLAP formalism to obtain the detailed description of the proton structure
in terms of the parton distribution functions (PDFs). However, when searching
for Beyond Standard Model (BSM) contributions in the data one should take into
account the possibility that the PDF set may already have been biased by
partially or totally absorbing previously unrecognised new physics
contributions. The ZEUS Collaboration has proposed a new approach to the BSM
analysis of the inclusive $ep$ data based on the simultaneous QCD fits of
parton distribution functions together with contributions of new physics
processes. Unfortunately, limit setting procedure in the frequentist approach
is very time consuming in this method, as full QCD analysis has to be repeated
for numerous data replicas. We describe a simplified approach, based on the
Taylor expansion of the cross section predictions in terms of PDF parameters,
which allowed us to reduce the calculation time for the BSM limits by almost
two orders of magnitude.


title: Verification Of The Jones Unknot Conjecture Up To 22 Crossings

abstract:
  We proved by computer enumeration that the Jones polynomial distinguishes the
unknot for knots up to 22 crossings. Following an approach of Yamada, we
generated knot diagrams by inserting algebraic tangles into Conway polyhedra,
computed their Jones polynomials by a divide-and-conquer method, and tested
those with trivial Jones polynomials for unknottedness with the computer
program SnapPy. We employed numerous novel strategies for reducing the
computation time per knot diagram and the number of knot diagrams to be
considered. That made computations up to 21 crossings possible on a single
processor desktop computer. We explain these strategies in this paper. We also
provide total numbers of algebraic tangles up to 18 crossings and of Conway
polyhedra up to 22 vertices. We encountered new unknot diagrams with no
crossing-reducing pass moves in our search. We report one such diagram in this
paper.


title:
Finite bias dependent evolution of superconductor-insulator transition
  and Zero Bias Conductance in boron doped nanodiamond films

abstract:
  We report on transport features in heavily boron doped nanocrystalline
diamond (BNCD) films which are not seen in conventional (s-wave) granular
superconductors. Observations include an anomalous resistance peak near to the
superconducting transition temperature as well as a strong zero bias
conductance peak in the current-voltage spectra. The effect of finite bias
current on the evolution of the resistance peak is systematically investigated
in this system. The shape of the resistance-temperature curves near the
critical temperature is seen to be strongly influenced by both magnetic field
and bias current. As the bias current is lowered the resistance peak becomes
more pronounced whereas when the magnetic field is varied the peak shifts
towards lower temperatures, the resistance upturn shows a quadratic temperature
dependence as expected for a Kondo transition. We find that a number of
transport features such as resistance peak height, zero bias conduction peak
height and width as well as magnetoresistance peaks scale according to a power
law dependence. We interpret these features as a result of a charge-Kondo
effect where hole dopants act as degenerate Kondo impurities by opening
additional pseudo-spin scattering channels.


title:
Locating topological phase transitions using nonequilibrium signatures
  in local bulk observables

abstract:
  Topological quantum phases cannot be characterized by local order parameters
in the bulk. In this work however, we show that signatures of a topological
quantum critical point do remain in local observables in the bulk, and manifest
themselves as non-analyticities in their expectation values taken over a family
of non-equilibrium states generated using a quantum quench protocol. The
signature can be used for precisely locating the critical points in parameter
space. A large class of initial states can be chosen for the quench (including
finite temperature states), the sufficient condition being existence of a
finite occupation-gradient with respect to energy for the single-particle
critical mode. We demonstrate these results in tractable models of
non-interacting fermions exhibiting topological phase transitions in one and
two spatial dimensions. We also show that the non-analyticities can be absent
if the gap-closing is non-topological, i.e., when it corresponds to no phase
transition.


title: Instruments on large optical telescopes -- A case study

abstract:
  In the distant past, telescopes were known, first and foremost, for the sizes
of their apertures. Advances in technology are now enabling astronomers to
build extremely powerful instruments to the extent that instruments have now
achieved importance comparable or even exceeding the usual importance accorded
to the apertures of the telescopes. However, the cost of successive generations
of instruments has risen at a rate noticeably above that of the rate of
inflation. Here, given the vast sums of money now being expended on optical
telescopes and their instrumentation, I argue that astronomers must undertake
"cost-benefit" analysis for future planning. I use the scientific output of the
first two decades of the W. M. Keck Observatory as a laboratory for this
purpose. I find, in the absence of upgrades, that the time to reach peak paper
production for an instrument is about six years. The prime lifetime of
instruments (sans upgrades), as measured by citations returns, is about a
decade. Well thought out and timely upgrades increase and sometimes even double
the useful lifetime. I investigate how well instrument builders are rewarded. I
find acknowledgements ranging from almost 100% to as low as 60%. Next, given
the increasing cost of operating optical telescopes, the management of existing
observatories continue to seek new partnerships. This naturally raises the
question "What is the cost of a single night of telescope time". I provide a
rational basis to compute this quantity. I then end the paper with some
thoughts on the future of large ground-based optical telescopes, bearing in
mind the explosion of synoptic precision photometric, astrometric and imaging
surveys across the electromagnetic spectrum, the increasing cost of
instrumentation and the rise of mega instruments.


title: Designing steep, sharp patterns on uniformly ion-bombarded surfaces

abstract:
  We propose and experimentally test a method to fabricate patterns of steep,
sharp features on surfaces, by exploiting the nonlinear dynamics of uniformly
ion bombarded surfaces. We show via theory, simulation, and experiment, that
the steepest parts of the surface evolve as one-dimensional curves which move
in the normal direction at constant velocity. The curves are a special solution
to the nonlinear equations that arises spontaneously whenever the initial
patterning on the surface contains slopes larger than a critical value;
mathematically they are traveling waves (shocks) that have the special property
of being undercompressive. We derive the evolution equation for the curves by
considering long-wavelength perturbations to the one-dimensional traveling
wave, using the unusual boundary conditions required for an undercompressive
shock, and we show this equation accurately describes the evolution of shapes
on surfaces, both in simulations and in experiments. Because evolving a
collection of one-dimensional curves is fast, this equation gives a
computationally efficient and intuitive method for solving the inverse problem
of finding the initial surface so the evolution leads to a desired target
pattern. We illustrate this method by solving for the initial surface that will
produce a lattice of diamonds connected by steep, sharp ridges, and
experimentally demonstrating the evolution of the initial surface into the
target pattern.


title: Regular Families of Kernels for Nonlinear Approximation

abstract:
  This article studies sufficient conditions on families of approximating
kernels which provide $N$--term approximation errors from an associated
nonlinear approximation space which match the best known orders of $N$--term
wavelet expansion. These conditions provide a framework which encompasses some
notable approximation kernels including splines, so-called cardinal functions,
and many radial basis functions such as the Gaussians and general
multiquadrics. Examples of such kernels are given to justify the criteria, and
some computational experiments are done to demonstrate the theoretical results.
Additionally, the techniques involved allow for some new results on $N$--term
interpolation of Sobolev functions via radial basis functions.


title: How Thermal Inflation can save Minimal Hybrid Inflation in Supergravity

abstract:
  Minimal hybrid inflation in supergravity has been ruled out by the 2015
Planck observations because the spectral index of the produced curvature
perturbation falls outside observational bounds. To resurrect the model, a
number of modifications have been put forward but many of them spoil the
accidental cancellation that resolves the eta-problem and require complicated
Kahler constructions to counterbalance the lost cancellation. In contrast, in
this paper the model is rendered viable by supplementing the scenario with a
brief period of thermal inflation, which follows the reheating of primordial
inflation. The scalar field responsible for thermal inflation requires a large
non-zero vacuum expectation value (VEV) and a flat potential. We investigate
the VEV of such a flaton field and its subsequent effect on the inflationary
observables. We find that, for large VEV, minimal hybrid inflation in
supergravity produces a spectral index within the 1-sigma Planck bound and a
tensor-to-scalar ratio which may be observable in the near future. The
mechanism is applicable to other inflationary models.


title:
Approximate formula for total cross section for moderately small eikonal
  function

abstract:
  The eikonal approximation for the total cross section for the scattering of
two unpolarized particles is studied. The approximate formula in the case when
the eikonal function chi(b) is moderately small, |chi(b)| < 0.1, is derived. It
is shown that the total cross section is given by the series of multiple
improper integrals of the Born amplitude A_B. Its advantage compared to
standard eikonal formulas is that the integrals contain no rapidly oscillating
Bessel functions. Two theorems which allow one to relate large-b behavior of
chi(b) with analytical properties of the Born amplitude are proved. Several
examples of these theorems are given. To check the efficiency of the main
formula, it is applied for numerical calculations of the total cross section
for a number of particular expressions of A_B. Only those Born amplitudes are
chosen which result in moderately small eikonal functions and lead to the
correct asymptotics of chi(b). The numerical calculations show that our formula
approximates the total cross section with the relative error of O(10^(-5)),
provided that the first three non-zero terms in it are taken into account.


title: Progressive Gauge U(1) Family Symmetry for Quarks and Leptons

abstract:
  The pattern of quark and lepton mass matrices is unexplained in the standard
model of particle interactions. I propose the novel idea of a progressive gauge
U(1) symmetry where it is a reflection of the regressive electroweak symmetry
breaking pattern, caused by an extended Higgs scalar sector. Phenomenological
implications of this new hypothesis are discussed.


title: The diffeology of Milnor's classifying space

abstract:
  We define a diffeology on the Milnor classifying space of a diffeological
group $G$, constructed in a similar fashion to the topological version using an
infinite join. Besides obtaining the expected classification theorem for smooth
principal bundles, we prove the existence of a diffeological connection on any
principal bundle (with mild conditions on the bundles and groups), and apply
the theory to some examples, including some infinite-dimensional groups, as
well as irrational tori.


title:
Crowdsourcing scoring of immunohistochemistry images: Evaluating
  Performance of the Crowd and an Automated Computational Method

abstract:
  The assessment of protein expression in immunohistochemistry (IHC) images
provides important diagnostic, prognostic and predictive information for
guiding cancer diagnosis and therapy. Manual scoring of IHC images represents a
logistical challenge, as the process is labor intensive and time consuming.
Since the last decade, computational methods have been developed to enable the
application of quantitative methods for the analysis and interpretation of
protein expression in IHC images. These methods have not yet replaced manual
scoring for the assessment of IHC in the majority of diagnostic laboratories
and in many large-scale research studies. An alternative approach is
crowdsourcing the quantification of IHC images to an undefined crowd. The aim
of this study is to quantify IHC images for labeling of ER status with two
different crowdsourcing approaches, image labeling and nuclei labeling, and
compare their performance with automated methods. Crowdsourcing-derived scores
obtained greater concordance with the pathologist interpretations for both
image labeling and nuclei labeling tasks (83% and 87%), as compared to the
pathologist concordance achieved by the automated method (81%) on 5,483 TMA
images from 1,909 breast cancer patients. This analysis shows that
crowdsourcing the scoring of protein expression in IHC images is a promising
new approach for large scale cancer molecular pathology studies.


title:
Plug-and-Play Model Predictive Control for Load Shaping and Voltage
  Control in Smart Grids

abstract:
  This paper presents a predictive controller for handling plug-and-play (P&P)
charging requests of flexible loads in a distribution system. We define two
types of flexible loads: (i) deferrable loads that have a fixed power profile
but can be deferred in time and (ii) shapeable loads that have flexible power
profiles but fixed energy requests, such as Plug-in Electric Vehicles (PEVs).
The proposed method uses a hierarchical control scheme based on a model
predictive control (MPC) formulation for minimizing the global system cost. The
first stage computes a reachable reference that trades off deviation from the
nominal voltage with the required generation control. The second stage uses a
price-based objective to aggregate flexible loads and provide load shaping
services, while satisfying system constraints and users' preferences at all
times. It is shown that the proposed controller is recursively feasible under
specific conditions, i.e. the flexible load demands are satisfied and bus
voltages remain within the desired limits. Finally, the proposed scheme is
illustrated on a 55 bus radial distribution network.


title:
Schlieren study of a sonic jet injected into a supersonic cross flow
  using high-current pulsed LEDs

abstract:
  Benefiting from the development of increasingly advanced high speed cameras,
flow visualization and analysis nowadays yield detailed data of the flow field
in many applications. Notwithstanding this progress, for high speed and
supersonic flows it is still not trivial to capture high quality images. In
this study we present a Schlieren setup that uses pulsed LEDs with high
currents (up to 18 Ampere) to increase the optical output to sufficient levels.
The bright and short pulses, down to 130 nanoseconds, allow detailed and sharp
imaging of the flow with a high spatial resolution adequate for supersonic
flow. The pulse circuit and pulse width determination are explained in detail.
As a test case we studied the near field of a 2 mm diameter sonic jet injected
transversely into a supersonic cross flow. This is a model flow for fuel
injection in scramjet engines, which is not yet fully understood. Owing to the
high resolution and accuracy of the images produced by the newly developed
system we prove the existence of a large (density) gradient wave traveling in
the windward subsonic region between the Mach barrel and the bowshock, which
hitherto was observed only in some numerical studies but not yet shown in
experiments. Furthermore, we demonstrate with this Schlieren setup that
time-correlated images can be obtained, with an interframe time of 2
microseconds, so that also flow unsteadiness can be studied such as the
movement of shock waves and trajectories of vortices. The obtained results of
the jet penetration height are presented as a power law correlation. The
results of this study show that the designed setup using a low-cost LED and
low-cost control system is a high potential option for application in
visualization studies of high speed flows.


title:
Perfect fractal sets with zero Fourier dimension and arbitrarily long
  arithmetic progressions

abstract:
  By considering a Moran-type construction of fractals on $[0,1]$, we show that
for any $0\le s\le 1$, there exists some Moran fractal set, which is perfect,
with Hausdorff dimension $s$ whose Fourier dimension is zero and it contains
arbitrarily long arithmetic progressions.


title: Ordered invariant ideals of Fourier-Stieltjes algebras

abstract:
  In a recent paper on exotic crossed products, we included a lemma concerning
ideals of the Fourier-Stieltjes algebra. Buss, Echterhoff, and Willett have
pointed out to us that our proof of this lemma contains an error. In fact, it
remains an open question whether the lemma is true as stated. In this note we
indicate how to contain the resulting damage.
  Our investigation of the above question leads us to define two properties
\emph{ordered} and \emph{weakly ordered} for invariant ideals of
Fourier-Stieltjes algebras, and we initiate a study of these properties.


title: On neutrinoless double beta decay in the $\nu$MSM

abstract:
  We consider the neutrinoless double beta ($0\nu \beta \beta$) decay in the
so-called $\nu$MSM, in which three right-handed neutrinos with masses below the
electroweak scale are additionally introduced to the Standard Model. In this
model there appear three heavy neutral leptons $N_1$, $N_2$, and $N_3$
corresponding to right-handed neutrinos. It has been known that the lightest
one $N_1$ with keV mass, which is a candidate for dark matter, gives a
negligible contribution to the $0 \nu \beta \beta$ decay. By contrast, the
heavier ones $N_2$ and $N_3$, which are responsible to the seesaw mechanism of
neutrino masses and baryogenesis, give the destructive contribution (compared
with one from active neutrinos). This is because their mass degeneracy at high
precision has been assumed, which is expected by analytical studies of
baryogengesis. In this analysis, we find that the effective mass of the $0\nu
\beta \beta$ decay becomes larger than one from active neutrinos due to the
$N_2$ and $N_3$ constructive contribution when the mass difference becomes
larger and the mass ordering of active neutrinos is inverted. Such a
possibility will be explored by the current and near future experiments of the
$0 \nu \beta \beta$ decay.


title: Lectures on the Quantum Hall Effect

abstract:
  The purpose of these lectures is to describe the basic theoretical structures
underlying the rich and beautiful physics of the quantum Hall effect. The focus
is on the interplay between microscopic wavefunctions, long-distance effective
Chern-Simons theories, and the modes which live on the boundary. The notes are
aimed at graduate students in any discipline where $\hbar=1$. A working
knowledge of quantum field theory is assumed. Contents:
  1. The Basics (Landau levels and Berry phase).
  2. The Integer Quantum Hall Effect.
  3. The Fractional Quantum Hall Effect.
  4. Non-Abelian Quantum Hall States.
  5. Chern-Simons Theories.
  6. Edge Modes.


title:
Generation of one-million-mode continuous-variable cluster state by
  unlimited time-domain multiplexing

abstract:
  In recent quantum optical continuous-variable experiments, the number of
fully inseparable light modes has drastically increased by introducing a
multiplexing scheme either in the time domain or in the frequency domain. Here,
modifying the time-domain multiplexing experiment reported in Nature Photonics
7, 982 (2013), we demonstrate successive generation of fully inseparable light
modes for more than one million modes. The resulting multi-mode state is useful
as a dual-rail CV cluster state. We circumvent the previous problem of optical
phase drifts, which has limited the number of fully inseparable light modes to
around ten thousands, by continuous feedback control of the optical system.


title: Three-Dimensional Orientation of Compact High Velocity Clouds

abstract:
  We present a proof-of-concept study of a method to estimate the inclination
angle of compact high velocity clouds (CHVCs), i.e. the angle between a CHVC's
trajectory and the line-of-sight. The inclination angle is derived from the
CHVC's morphology and kinematics. We calibrate the method with numerical
simulations, and we apply it to a sample of CHVCs drawn from HIPASS.
Implications for CHVC distances are discussed.


title:
Leptogenesis from Oscillations of Heavy Neutrinos with Large Mixing
  Angles

abstract:
  The extension of the Standard Model by heavy right-handed neutrinos can
simultaneously explain the observed neutrino masses via the seesaw mechanism
and the baryon asymmetry of the Universe via leptogenesis. If the mass of the
heavy neutrinos is below the electroweak scale, they may be found at the LHC,
BELLE II, NA62, the proposed SHiP experiment or a future high-energy collider.
In this mass range, the baryon asymmetry is generated via CP-violating
oscillations of the heavy neutrinos during their production. We study the
generation of the baryon asymmetry of the Universe in this scenario from first
principles of non-equilibrium quantum field theory,including spectator
processes and feedback effects. We eliminate several uncertainties from
previous calculations and find that the baryon asymmetry of the Universe can be
explained with larger heavy neutrino mixing angles, increasing the chance for
an experimental discovery. For the limiting cases of fast and strongly
overdamped oscillations of right-handed neutrinos, the generation of the baryon
asymmetry can be calculated analytically up to corrections of order one.


title:
On the $L^p$ boundedness of wave operators for four-dimensional
  Schr\"odinger Operators with a threshold eigenvalue

abstract:
  Let $H=-\Delta+V$ be a Schr\"odinger operator on $L^2(\mathbb R^4)$ with
real-valued potential $V$, and let $H_0=-\Delta$. If $V$ has sufficient
pointwise decay, the wave operators $W_{\pm}=s-\lim_{t\to \pm\infty}
e^{itH}e^{-itH_0}$ are known to be bounded on $L^p(\mathbb R^4)$ for all $1\leq
p\leq \infty$ if zero is not an eigenvalue or resonance, and on $\frac43<p<4$
if zero is an eigenvalue but not a resonance. We show that in the latter case,
the wave operators are also bounded on $L^p(\mathbb R^4)$ for $1\leq p\leq
\frac43$ by direct examination of the integral kernel of the leading terms.
Furthermore, if $\int_{\mathbb R^4} xV(x) \psi(x) \, dx=0$ for all zero energy
eigenfunctions $\psi$, then the wave operators are bounded on $L^p$ for $1 \leq
p<\infty$.


title: A Delay Optimal MAC and Packet Scheduler for Heterogeneous M2M Uplink

abstract:
  The uplink data arriving at the Machine-to-Machine (M2M) Application Server
(AS) via M2M Aggregators (MAs) is fairly heterogeneous along several dimensions
such as maximum tolerable packet delay, payload size and arrival rate, thus
necessitating the design of Quality-of-Service (QoS) aware packet scheduler. In
this paper, we classify the M2M uplink data into multiple QoS classes and use
sigmoidal function to map the delay requirements of each class onto utility
functions. We propose a proportionally fair delay-optimal multiclass packet
scheduler at AS that maximizes a system utility metric. We note that the
average class delay under any work-conserving scheduling policy can be realized
by appropriately time-sharing between all possible preemptive priority
policies. Therefore the optimal scheduler is determined using an iterative
process to determine the optimal time-sharing between all priority scheduling
policies, such that it results in maximum system utility. The proposed
scheduler can be implemented online with reduced complexity due to the
iterative optimization process. We then extend this work to determine jointly
optimal MA-AS channel allocation and packet scheduling scheme at the MAs and
AS. We first formulate a joint optimization problem that is solved centrally at
the AS and then propose a low complexity distributed optimization problem
solved independently at MAs and AS. We show that the distributed optimization
solution converges quickly to the centralized optimization result with minimal
information exchange overhead between MAs and AS. Using Monte-Carlo
simulations, we verify the optimality of the proposed scheduler and show that
it outperforms other state-of-the-art packet schedulers such as weighted round
robin, max-weight scheduler etc. Another desirable feature of proposed
scheduler is low delay jitter for delay-sensitive traffic.


title:
Incorporating doubly resonant $W^\pm$ data in a global fit of SMEFT
  parameters to lift flat directions

abstract:
  We calculate the double pole contribution to two to four fermion scattering
through $W^{\pm}$ currents at tree level in the Standard Model Effective Field
Theory (SMEFT). We assume all fermions to be massless, $\rm U(3)^5$ flavour and
$\rm CP$ symmetry. Using this result, we update the global constraint picture
on SMEFT parameters including LEPII data on these charged current processes,
and also include modifications to our fit procedure motivated by a companion
paper focused on $W^{\pm}$ mass extractions. The fit reported is now to 177
observables and emphasises the need for a consistent inclusion of theoretical
errors, and a consistent treatment of observables. Including charged current
data lifts the two-fold degeneracy previously encountered in LEP (and lower
energy) data, and allows us to set simultaneous constraints on 20 of 53 Wilson
coefficients in the SMEFT, consistent with our assumptions. This allows the
model independent inclusion of LEP data in SMEFT studies at LHC, which are
projected into the SMEFT in a consistent fashion. We show how stronger
constraints can be obtained by using some combinations of Wilson coefficients,
when making assumptions on the UV completion of the Standard Model, or in an
inconsistent analysis. We explain why strong bounds at the per-mille or
sub-per-mille level on some combinations of Wilson coefficients in the
Effective Lagrangian can be artificially enhanced in fits of this form in
detail. This explains some of the different claims present in the literature.


title: Anisotropic Non-Fermi Liquids

abstract:
  We study non-Fermi liquid states that arise at the quantum critical points
associated with the spin density wave (SDW) and charge density wave (CDW)
transitions in metals with twofold rotational symmetry. We use the dimensional
regularization scheme, where a one-dimensional Fermi surface is embedded in
$3-\epsilon$ dimensional momentum space. In three dimensions, quasilocal
marginal Fermi liquids arise both at the SDW and CDW critical points : the
speed of the collective mode along the ordering wavevector is logarithmically
renormalized to zero compared to that of Fermi velocity. Below three
dimensions, however, the SDW and CDW critical points exhibit drastically
different behaviors. At the SDW critical point, a stable anisotropic non-Fermi
liquid state is realized for small $\epsilon$, where not only time but also
different spatial coordinates develop distinct anomalous dimensions. The
non-Fermi liquid exhibits an emergent algebraic nesting as the patches of Fermi
surface are deformed into a universal power-law shape near the hot spots. Due
to the anisotropic scaling, the energy of incoherent spin fluctuations disperse
with different power laws in different momentum directions. At the CDW critical
point, on the other hand, the perturbative expansion breaks down immediately
below three dimensions as the interaction renormalizes the speed of charge
fluctuations to zero within a finite renormalization group scale through a
two-loop effect. The difference originates from the fact that the vertex
correction anti-screens the coupling at the SDW critical point whereas it
screens at the CDW critical point.


title:
Big Bang Nucleosynthesis in the presence of sterile neutrinos with
  altered dispersion relations

abstract:
  Big Bang Nucleosynthesis imposes stringent bounds on light sterile neutrinos
mixing with the active flavors. Here we discuss how altered dispersion
relations can weaken such bounds and allow compatibility of new sterile
neutrino degrees of freedom with a successful generation of the light elements
in the early Universe.


title: Resurgence of $Z'$ from the single electron-muon event at ATLAS

abstract:
  Inspired by the recent single $e^{\pm}\mu^{\mp}$ event at 2.1 TeV invariant
mass from the ATLAS at $\sqrt{s}=13$ TeV with 3.2 fb$^{-1}$ luminosity, we
propose an explanation using a $Z'$ gauge boson, which possesses
lepton-flavor-changing neutral currents originated from non-universal couplings
to charged leptons. We assume that the left-handed charged-lepton mixing matrix
equals to the PMNS matrix and no mixing in the neutrino sector to make this
phenomenological $Z'$ model more predictive. There are indeed some parameter
regions, where the $Z'$ can generate a large enough $e^{\pm}\mu^{\mp}$
production cross section, while at the same time satisfies various observables
from lepton-flavor violation and other constraints from the LHC.


title:
Beam Dynamics Studies and Design Optimisation of New Low Energy
  Antiproton Facilities

abstract:
  Antiprotons, stored and cooled at low energies in a storage ring or at rest
in traps, are highly desirable for the investigation of a large number of basic
questions on fundamental interactions. This includes the static structure of
antiprotonic atomic systems and the time-dependent quantum dynamics of
correlated systems. The Antiproton Decelerator (AD) at CERN is currently the
worlds only low energy antiproton factory dedicated to antimatter experiments.
New antiproton facilities, such as the Extra Low ENergy Antiproton ring (ELENA)
at CERN and the Ultra-low energy Storage Ring (USR) at FLAIR, will open unique
possibilities. They will provide cooled, high quality beams of extra-low energy
antiprotons at intensities exceeding those achieved presently at the AD by
factors of ten to one hundred. These facilities, operating in the energy regime
between 100 keV down to 20 keV, face several design and beam dynamics
challenges, for example nonlinearities, space charge and scattering effects
limiting beam life time. Detailed investigations into the low energy and long
term beam dynamics have been carried out to address many of those challenges
towards the design optimisation. Results from these studies are presented in
this contribution, showing some examples for ELENA.


title:
Vulnerability of Fixed-Time Control of Signalized Intersections to
  Cyber-Tampering

abstract:
  Recent experimental studies have shown that traffic management systems are
vulnerable to cyber-attacks on sensor data. This paper studies the
vulnerability of fixed-time control of signalized intersections when sensors
measuring traffic flow information are compromised and perturbed by an
adversary. The problems are formulated by considering three malicious
objectives: 1) worst-case network accumulation, which aims to destabilize the
overall network as much as possible; 2) worst-case lane accumulation, which
aims to cause worst-case accumulation on some target lanes; and 3) risk-averse
target accumulation, which aims to reach a target accumulation by making the
minimum perturbation to sensor data. The problems are solved using bilevel
programming optimization methods. Finally, a case study of a real network is
used to illustrate the results.


title:
Resilient Supervisory Control of Autonomous Intersections in the
  Presence of Sensor Attacks

abstract:
  Cyber-physical systems (CPS), such as autonomous vehicles crossing an
intersection, are vulnerable to cyber-attacks and their safety-critical nature
makes them a target for malicious adversaries. This paper studies the problem
of supervisory control of autonomous intersections in the presence of sensor
attacks. Sensor attacks are performed when an adversary gains access to the
transmission channel and corrupts the measurements before they are received by
the decision-making unit. We show that the supervisory control system is
vulnerable to sensor attacks that can cause collision or deadlock among
vehicles. To improve the system resilience, we introduce a detector in the
control architecture and focus on stealthy attacks that cannot be detected but
are capable of compromising safety. We then present a resilient supervisory
control system that is safe, non-deadlocking, and maximally permissive, despite
the presence of disturbances, uncontrolled vehicles, and sensor attacks.
Finally, we demonstrate how the resilient supervisor works by considering
illustrative examples.


title:
HIDES spectroscopy of bright detached eclipsing binaries from the
  $Kepler$ field - I. Single-lined objects

abstract:
  We present results of our spectroscopic observations of nine detached
eclipsing binaries (DEBs), selected from the $Kepler$ Eclipsing Binary Catalog,
that only show one set of spectral lines. Radial velocities (RVs) were
calculated from the high resolution spectra obtained with the HIDES instrument,
attached to the 1.88-m telescope at the Okayama Astrophysical Observatory, and
from the public APOGEE archive. In our sample we found five single-lined
binaries, with one component dominating the spectrum. The orbital and light
curve solutions were found for four of them, and compared with isochrones, in
order to estimate absolute physical parameters and evolutionary status of the
components. For the fifth case we only update the orbital parameters, and
estimate the properties of the unseen star. Two other systems show orbital
motion with a period known from the eclipse timing variations (ETVs). For these
we obtained parameters of outer orbits, by translating the ETVs to RVs of the
centre of mass of the eclipsing binary, and combining with the RVs of the outer
star. Of the two remaining ones, one is most likely a blend of a faint
background DEB with a bright foreground star, which lines we see in the
spectra, and the last case is possibly a quadruple bearing a sub-stellar mass
object. Where possible, we compare our results with literature, especially with
results from asteroseismology. We also report possible detections of solar-like
oscillations in our RVs.


title: On non-commutative rank and tensor rank

abstract:
  We study the relationship between the commutative and the non-commutative
rank of a linear matrix. We give examples that show that the ratio of the two
ranks comes arbitrarily close to 2. Such examples can be used for giving lower
bounds for the border rank of a given tensor. Landsberg used such techniques to
give nontrivial equations for the tensors of border rank at most $2m-3$ in
$K^m\otimes K^m\otimes K^m$ if $m$ is even. He also gave such equations for
tensors of border rank at most $2m-5$ in $K^m\otimes K^m\otimes K^m$ if $m$ is
odd. Using concavity of tensor blow-ups we show non-trivial equations for
tensors of border rank $2m-4$ in $K^m \otimes K^m \otimes K^m$ for odd $m$ for
any field $K$ of characteristic 0. We also give another proof of the regularity
lemma by Ivanyos, Qiao and Subrahmanyam.


title:
Crowdsourcing for Identification of Polyp-Free Segments in Virtual
  Colonoscopy Videos

abstract:
  Virtual colonoscopy (VC) allows a physician to virtually navigate within a
reconstructed 3D colon model searching for colorectal polyps. Though VC is
widely recognized as a highly sensitive and specific test for identifying
polyps, one limitation is the reading time, which can take over 30 minutes per
patient. Large amounts of the colon are often devoid of polyps, and a way of
identifying these polyp-free segments could be of valuable use in reducing the
required reading time for the interrogating radiologist. To this end, we have
tested the ability of the collective crowd intelligence of non-expert workers
to identify polyp candidates and polyp-free regions. We presented twenty short
videos flying through a segment of a virtual colon to each worker, and the
crowd was asked to determine whether or not a possible polyp was observed
within that video segment. We evaluated our framework on Amazon Mechanical Turk
and found that the crowd was able to achieve a sensitivity of 80.0% and
specificity of 86.5% in identifying video segments which contained a clinically
proven polyp. Since each polyp appeared in multiple consecutive segments, all
polyps were in fact identified. Using the crowd results as a first pass, 80% of
the video segments could in theory be skipped by the radiologist, equating to a
significant time savings and enabling more VC examinations to be performed.


title: On the fourth moment of Hecke Maass forms and the Random Wave Conjecture

abstract:
  Conditionally on the Generalized Lindel\"of Hypothesis, we obtain an
asymptotic for the fourth moment of Hecke Maass cusp forms of large Laplacian
eigenvalue for the full modular group. This lends support to the Random Wave
Conjecture.


title:
Improving Testability and Reuse by Transitioning to Functional
  Programming

abstract:
  Declarative styles such as functional programming (FP) are rapidly gaining
ground on their imperative cousins, including procedural and object-oriented
programming. The shift is subtle because it is happening within the context of
multiparadigm programming languages such as JavaScript. FP is better suited to
modern processes like test-driven development (TDD), and architectures like
massively parallel, cloud-based computing. This article describes the technical
details that characterize the shift from imperative to FP and implications for
software quality management, particularly reuse and testability.


title: A note on weighted iterated Hardy-type inequalities

abstract:
  In this paper the inequality $$ \bigg( \int_0^{\infty} \bigg( \int_x^{\infty}
\bigg( \int_t^{\infty} h \bigg)^q w(t)\,dt \bigg)^{r / q} u(x)\,ds
\bigg)^{1/r}\leq C \,\int_0^{\infty} h v, \quad h \in {\mathfrak M}^+(0,\infty)
$$ is characterized. Here $0 < q ,\, r < \infty$ and $u,\,v,\,w$ are weight
functions on $(0,\infty)$.


title:
On the equation $p
  \frac{\Gamma(\frac{n}{2}-\frac{s}{p-1})\Gamma(s+\frac{s}{p-1})}{\Gamma(\frac{s}{p-1})\Gamma(\frac{n-2s}{2}-\frac{s}{p-1})}
  =\frac{\Gamma(\frac{n+2s}{4})^2}{\Gamma(\frac{n-2s}{4})^2}$

abstract:
  The note is aimed at giving a complete characterization of the following
equation: $$\displaystyle
p\frac{\Gamma(\frac{n}{2}-\frac{s}{p-1})\Gamma(s+\frac{s}{p-1})}{\Gamma(\frac{s}{p-1})\Gamma(\frac{n-2s}{2}-\frac{s}{p-1})}
=\frac{\Gamma(\frac{n+2s}{4})^2}{\Gamma(\frac{n-2s}{4})^2}.$$
  The method is based on some key transformation and the properties of the
Gamma function. Applications to fractional nonlinear Lane-Emden equations will
be given.


title:
Optimal Thresholds for Anomaly-Based Intrusion Detection in Dynamical
  Environments

abstract:
  In cyber-physical systems, malicious and resourceful attackers could
penetrate the system through cyber means and cause significant physical damage.
Consequently, detection of such attacks becomes integral towards making these
systems resilient to attacks. To achieve this objective, intrusion detection
systems (IDS) that are able to detect malicious behavior can be deployed.
However, practical IDS are imperfect and sometimes they may produce false
alarms for a normal system behavior. Since alarms need to be investigated for
any potential damage, a large number of false alarms may increase the
operational costs significantly. Thus, IDS need to be configured properly, as
oversensitive IDS could detect attacks early but at the cost of a higher number
of false alarms. Similarly, IDS with low sensitivity could reduce the false
alarms while increasing the time to detect the attacks. The configuration of
IDS to strike the right balance between time to detecting attacks and the rate
of false positives is a challenging task, especially in dynamic environments,
in which the damage incurred by a successful attack is time-varying.
  In this paper, we study the problem of finding optimal detection thresholds
for anomaly-based detectors implemented in dynamical systems in the face of
strategic attacks. We formulate the problem as an attacker-defender security
game, and determine thresholds for the detector to achieve an optimal trade-off
between the detection delay and the false positive rates. In this direction,
first, we provide an algorithm that computes optimal fixed threshold that
remains fixed throughout. Second, we allow detector's threshold to change with
time to further minimize the defender's loss and provide an algorithm to
compute time-varying thresholds, which we call adaptive thresholds. Finally, we
numerically evaluate our results using a water distribution network as a
case-study.


title: Degenerate billiards

abstract:
  In an ordinary billiard system trajectories of a Hamiltonian system are
elastically reflected after a collision with a hypersurface (scatterer). If the
scatterer is a submanifold of codimension more than one, we say that the
billiard is degenerate. Then collisions are rare. We study trajectories of
degenerate billiards which have an infinite number of collisions with the
scatterer. Degenerate billiards appear as limits of systems with elastic
reflections or as limits of systems with singularities in celestial mechanics.
We prove the existence of trajectories of such systems shadowing trajectories
of the corresponding degenerate billiards. The proofs are based on a version of
the method of an anti-integrable limit.


title:
Guaranteed Cost Model Predictive Control-based Driver Assistance System
  for Vehicle Stabilization Under Tire Parameters Uncertainties

abstract:
  Road traffic crashes have been the leading cause of death among young people.
Most of these accidents occur when the driver becomes distracted and a
loss-of-control situation occurs. Steer-by-Wire systems were recently proposed
as an alternative to mitigate such accidents. This technology enables the
decoupling of the front wheel steering angles from the driver hand wheel angle
and, consequently, the measurement of road/tire friction limits and the
development of novel control systems capable of ensuring vehicle stabilization
and safety. However, vehicle safety boundaries are highly dependent on tire
characteristics which vary significantly with temperature, wear and the tire
manufacturing process. Therefore, design of autonomous vehicle and driver
assistance controllers cannot assume that these characteristics are constant or
known. Thus, this paper proposes a Guaranteed Cost Model Predictive Controller
Driver Assistance System able to avoid front and rear tire saturation and to
track the drivers intent up to the limits of handling for a vehicle with
uncertain tire parameters. Simulation results show the performance of the
proposed approach under time-varying uniformly distributed disturbances.


title: Correlation-based Intrinsic Evaluation of Word Vector Representations

abstract:
  We introduce QVEC-CCA--an intrinsic evaluation metric for word vector
representations based on correlations of learned vectors with features
extracted from linguistic resources. We show that QVEC-CCA scores are an
effective proxy for a range of extrinsic semantic and syntactic tasks. We also
show that the proposed evaluation obtains higher and more consistent
correlations with downstream tasks, compared to existing approaches to
intrinsic evaluation of word vectors that are based on word similarity.


title:
Investigations of temperature-dependent photoluminescence of uncoated
  and silver-coated CdS quantum dots

abstract:
  We report temperature-dependent photoluminescence (PL) studies and PL
relaxation dynamics for uncoated and silver-coated CdS quantum dots (QDs).
Room-temperature photoluminescence studies indicate that the presence of silver
coating on CdS QD samples enhances the blue luminescence corresponding to the
band-to-band transitions by a factor of ten compared to the uncoated samples.
Furthermore, the decay time measurements using Time Correlated Single Photon
Counting technique demonstrate F\"{o}rster resonance energy transfer (FRET)
between silver-shell and CdS-core in silver-coated CdS QD samples. A detailed
investigation of temperature-dependent PL spectra of uncoated CdS QD samples
reveals the role of thermally-activated surface-trap states, exciton-LO phonon
coupling and ionized impurity scattering. In case of silver-coated QDs, the
temperature-dependent PL peak energy corresponding to the band-to-band
transitions presents a consecutive red-blue-red shift (S-shaped) behavior.
Whereas, the full width at half maximum (FWHM) shows a successive blue-red-blue
shift (inverted S-shaped) characteristic with increasing temperature.


title: Open intersection numbers and free fields

abstract:
  A complete set of the Virasoro and W-constraints for the Kontsevich-Penner
model, which conjecturally describes intersections on moduli spaces of open
curves, was derived in our previous work. Here we show that these constraints
can be described in terms of free bosonic fields with twisted boundary
conditions, which gives a modification of the well-known construction of the
$W^{(3)}$ algebra in conformal field theory. This description is natural from
the point of view of the spectral curve description, and should serve as a new
important ingredient of the topological recursion/Givental decomposition.


title:
Predictive coupled-cluster isomer orderings for some Si${}_n$C${}_m$
  ($m, n\le 12$) clusters; A pragmatic comparison between DFT and complete
  basis limit coupled-cluster benchmarks

abstract:
  The accurate determination of the preferred ${\rm Si}_{12}{\rm C}_{12}$
isomer is important to guide experimental efforts directed towards synthesizing
SiC nano-wires and related polymer structures which are anticipated to be
highly efficient exciton materials for opto-electronic devices. In order to
definitively identify preferred isomeric structures for silicon carbon
nano-clusters, highly accurate geometries, energies and harmonic zero point
energies have been computed using coupled-cluster theory with systematic
extrapolation to the complete basis limit for set of silicon carbon clusters
ranging in size from SiC$_3$ to ${\rm Si}_{12}{\rm C}_{12}$. It is found that
post-MBPT(2) correlation energy plays a significant role in obtaining converged
relative isomer energies, suggesting that predictions using low rung density
functional methods will not have adequate accuracy. Utilizing the best
composite coupled-cluster energy that is still computationally feasible,
entailing a 3-4 SCF and CCSD extrapolation with triple-$\zeta$ (T) correlation,
the {\it closo} ${\rm Si}_{12}{\rm C}_{12}$ isomer is identified to be the
preferred isomer in support of previous calculations [J. Chem. Phys. 2015, 142,
034303]. Additionally we have investigated more pragmatic approaches to
obtaining accurate silicon carbide isomer energies, including the use of frozen
natural orbital coupled-cluster theory and several rungs of standard and
double-hybrid density functional theory. Frozen natural orbitals as a way to
compute post MBPT(2) correlation energy is found to be an excellent balance
between efficiency and accuracy.


title:
Subharmonic test functions and the distribution of zero sets of
  holomorphic functions

abstract:
  Let $m,n\geq 1$ are integers and $D$ be a domain in the $$ $\mathbb C^n$ or
in the $m$-dimensional real space $\mathbb R^m$. We build positive subharmonic
functions on $D$ vanishing on the boundary $\partial D$ of $D$.
  We use such (test) functions to study the distribution of zero sets of
holomorphic functions $f$ on $D\subset \mathbb C^n$ with restrictions on the
growth of $f$ near the boundary $\partial D$.


title:
Characterization of the scintillation anisotropy in crystalline stilbene
  scintillator detectors

abstract:
  This paper reports a series of measurements that characterize the directional
dependence of the scintillation response of crystalline melt-grown and
solution-grown stilbene to incident DT and DD neutrons. These measurements give
the amplitude and pulse shape dependence on the proton recoil direction over
one hemisphere of the crystal, confirming and extending previous results in the
literature for melt-grown stilbene and providing the first measurements for
solution-grown stilbene. In similar measurements of liquid and plastic
detectors, no directional dependence was observed, confirming the hypothesis
that the anisotropy in stilbene and other organic crystal scintillators is a
result of internal effects due to the molecular or crystal structure and not an
external effect on the measurement system.


title: A vanishing result for tautological classes on the moduli of K3 surfaces

abstract:
  Looijenga's vanishing theorem on the moduli space of curves $M_g$ says that
the tautological ring vanishes above degree $g-2$. We prove an analogous result
for the tautological cohomology ring of the moduli space of K3 surfaces.


title: On a Minimax Problem for Ovals

abstract:
  For a bounded metric space $ X $ one can consider the quantity $ \delta(X) :=
\text{inf\rule[-0.5ex]{0em}{1ex}}_{\,p\in X}\; \text{sup}_{q \in X} \; d(p,q)
$. This purely metric invariant is known from approximation theory as the
relative Chebyshev radius of $ X $ w.r.t. $ X $ itself. Despite its obvious
meaning, $ \delta(X) $ seems rather untouched in the geometric literature. In
this paper we discuss, for plane convex curves $ X $, an isoperimetric type
inequality, relating $ \delta(X) $ to the perimeter of the curve. Due to the
minimax character of $ \delta(X) $, its handling resists the usual principles
for extremal questions. It will be shown that the smooth case of the inequality
can be reduced to the polygonal case by approximation. However, for polygons,
there is the additional problem of the high dimensionality of the set of
vertices. So, in general, we only can offer conjectures. Definite solutions are
possible for restricted classes of curves. Even for short polygons, there
already arises a sort of `magic kites' which show that squares are definitely
not the extremal figures.


title: Iterating Symmetric Extensions

abstract:
  The notion of a symmetric extension extends the usual notion of forcing by
identifying a particular class of names which forms an intermediate model of ZF
between the ground model and the generic extension, and often the axiom of
choice fails in these models. Symmetric extensions are generally used to prove
choiceless consistency results. We develop a framework for iterating symmetric
extensions in order to construct new models of ZF. We show how to obtain some
well-known and lesser-known results using this framework. Specifically, we
discuss Kinna--Wagner principles and obtain some results related to their
failure.


title: Testable Baryogenesis in Seesaw Models

abstract:
  We revisit the production of baryon asymmetries in the minimal type I seesaw
model with heavy Majorana singlets in the GeV range. In particular we include
"washout" effects from scattering processes with gauge bosons, Higgs decays and
inverse decays, besides the dominant top scatterings. We show that in the
minimal model with two singlets, and for an inverted light neutrino ordering,
future measurements from SHiP and neutrinoless double beta decay could in
principle provide sufficient information to predict the matter-antimatter
asymmetry in the universe. We also show that SHiP measurements could provide
very valuable information on the PMNS CP phases.


title:
A mathematical model of demand-supply dynamics with collectability and
  saturation factors

abstract:
  We introduce a mathematical model on the dynamics of demand and supply
incorporating collectability and saturation factors. Our analysis shows that
when the fluctuation of the determinants of demand and supply is strong enough,
there is chaos in the demand-supply dynamics. Our numerical simulation shows
that such a chaos is not an attractor (i.e. dynamics is not approaching the
chaos), instead a periodic attractor (of period 3 under the Poincar\'e period
map) exists near the chaos, and co-exists with another periodic attractor (of
period 1 under the Poincar\'e period map) near the market equilibrium. Outside
the basins of attraction of the two periodic attractors, the dynamics
approaches infinity indicating market irrational exuberance or flash crash. The
period 3 attractor represents the product's market cycle of growth and
recession, while period 1 attractor near the market equilibrium represents the
regular fluctuation of the product's market. Thus our model captures more
market phenomena besides Marshall's market equilibrium. When the fluctuation of
the determinants of demand and supply is strong enough, a three leaf danger
zone exists where the basins of attraction of all attractors intertwine and
fractal basin boundaries are formed. Small perturbations in the danger zone can
lead to very different attractors. That is, small perturbations in the danger
zone can cause the market to experience oscillation near market equilibrium,
large growth and recession cycle, and irrational exuberance or flash crash.


title: Lebesgue inequalities for the greedy algorithm in general bases

abstract:
  We present various estimates for the Lebesgue constants of the thresholding
greedy algorithm, in the case of general bases in Banach spaces. We show the
optimality of these estimates in some situations. Our results recover and
slightly improve various estimates appearing earlier in the literature.


title:
Tuning the electronic hybridization in the heavy fermion cage compound
  YbFe$_{2}$Zn$_{20}$ with Cd-doping

abstract:
  Tuning of the electronic properties of heavy fermion compounds by chemical
substitutions provides excellent opportunities to further understand the
physics of hybridized ions in crystal lattices. Here we present an
investigation on the effects of Cd doping in flux-grown single crystals of the
complex intermetallic cage compound YbFe$_{2}$Zn$_{20}$, that has been
described as a heavy fermion with Sommerfeld coefficient of 535 mJ/mol.K$^{2}$.
Substitution of Cd for Zn disturbs the system by expanding the unit cell and,
in this case, the size of the Zn cages that surround Yb and Fe. With increasing
amount of Cd, the hybridization between Yb $4f$ electrons and the conduction
electrons is weakened, as evidenced by a decrease in the Sommerfeld
coefficient, which should be accompanied by a valence shift of the Yb$^{3+}$
due to the negative chemical pressure effect. This scenario is also supported
by the low temperature dc-magnetic susceptibility, that is gradually suppressed
and evidences an increment of the Kondo temperature, based on a shift to higher
temperatures of the characteristic broad susceptibility peak. Furthermore, the
DC resistivity decreases with the isoelectronic Cd substitution for Zn,
contrary to the expectation for an increasingly disordered system, and implying
that the valence shift is not related to charge carrier doping. The combined
results demonstrate excellent complementarity between positive physical
pressure and negative chemical pressure, and point to a rich playground for
exploring the physics and chemistry of strongly correlated electron systems in
the general family of Zn$_{20}$ compounds, despite their structural complexity.


title: Cutoff for random walks on graphs with bottlenecks

abstract:
  We examine the mixing time for random walks on graphs. In particular we are
interested on investigating graphs with bottlenecks. Furthermore, the cutoff
phenomenon is examined.


title: Tagger: Deep Unsupervised Perceptual Grouping

abstract:
  We present a framework for efficient perceptual inference that explicitly
reasons about the segmentation of its inputs and features. Rather than being
trained for any specific segmentation, our framework learns the grouping
process in an unsupervised manner or alongside any supervised task. By
enriching the representations of a neural network, we enable it to group the
representations of different objects in an iterative manner. By allowing the
system to amortize the iterative inference of the groupings, we achieve very
fast convergence. In contrast to many other recently proposed methods for
addressing multi-object scenes, our system does not assume the inputs to be
images and can therefore directly handle other modalities. For multi-digit
classification of very cluttered images that require texture segmentation, our
method offers improved classification performance over convolutional networks
despite being fully connected. Furthermore, we observe that our system greatly
improves on the semi-supervised result of a baseline Ladder network on our
dataset, indicating that segmentation can also improve sample efficiency.


title: Technical Considerations in Magnetic Analogue Models

abstract:
  The analogy between vorticity and magnetic fields has been a subject of
interest to researchers for a considerable period of time, mainly because of
the structural similarities between the systems of equations that govern the
evolution of the two fields. We recently presented the analysis of magnetic
fields and hydrodynamics vorticity fields and argued for a formal theory of
analogue magnetism. This article provides in depth technical details of the
relevant considerations for the simulation procedures and extends the analyses
to a range of fluids.

categories: physics.flu-dyn astro-ph.CO astro-ph.GA gr-qc


title:
Adaptive Just-in-time Value Class Optimization for Lowering Memory
  Consumption and Improving Execution Time Performance

abstract:
  The performance of value classes is highly dependent on how they are
represented in the virtual machine. Value class instances are immutable, have
no identity, and can only refer to other value objects or primitive values and
since they should be very lightweight and fast, it is important to optimize
them carefully. In this paper we present a technique to detect and compress
common patterns of value class usage to improve memory usage and performance.
The technique identifies patterns of frequent value object references and
introduces abbreviated forms for them. This allows to store multiple
inter-referenced value objects in an inlined memory representation, reducing
the overhead stemming from meta-data and object references. Applied to a small
prototype and an implementation of the Racket language, we found improvements
in memory usage and execution time for several micro-benchmarks.


title: Force-Free Foliations

abstract:
  Electromagnetic field configurations with vanishing Lorentz force density are
known as force-free and appear in terrestrial, space, and astrophysical
plasmas. We explore a general method for finding such configurations based on
formulating equations for the field lines rather than the field itself. The
basic object becomes a foliation of spacetime or, in the stationary
axisymmetric case, of the half-plane. We use this approach to find some new
stationary and axisymmetric solutions, one of which could represent a rotating
plasma vortex near a magnetic null point.

categories: math-ph astro-ph.HE gr-qc hep-th math.MP


title:
Brownian motion of massive black hole binaries and the final parsec
  problem

abstract:
  Massive black hole binaries (BHBs) are expected to be one of the most
powerful sources of gravitational waves (GWs) in the frequency range of the
pulsar timing array and of forthcoming space-borne detectors. They are believed
to form in the final stages of galaxy mergers, and then harden by slingshot
ejections of passing stars. However, evolution via the slingshot mechanism may
be ineffective if the reservoir of interacting stars is not readily
replenished, and the binary shrinking may come to a halt at roughly a parsec
separation. Recent simulations suggest that the departure from spherical
symmetry, naturally produced in merger remnants, leads to efficient loss cone
refilling, preventing the binary from stalling. However, current N-body
simulations able to accurately follow the evolution of BHBs are limited to very
modest particle numbers. Brownian motion may artificially enhance the loss cone
refilling rate in low-N simulations, where the binary encounters a larger
population of stars due its random motion. Here we study the significance of
Brownian motion of BHBs in merger remnants in the context of the final parsec
problem. We simulate mergers with various particle numbers (from 8k to 1M) and
with several density profiles. Moreover, we compare simulations where the BHB
is fixed at the centre of the merger remnant with simulations where the BHB is
free to random walk. We find that Brownian motion does not significantly affect
the evolution of BHBs in simulations with particle numbers in excess of one
million, and that the hardening measured in merger simulations is due to
collisionless loss cone refilling.


title:
A Neptune-sized transiting planet closely orbiting a
  5-10-million-year-old star

abstract:
  Theories of the formation and early evolution of planetary systems postulate
that planets are born in circumstellar disks, and undergo radial migration
during and after dissipation of the dust and gas disk from which they formed.
The precise ages of meteorites indicate that planetesimals - the building
blocks of planets - are produced within the first million years of a star's
life. A prominent question is: how early can one find fully formed planets like
those frequently detected on short orbital periods around mature stars? Some
theories suggest the in situ formation of planets close to their host stars is
unlikely and the existence of such planets is evidence for large scale
migration. Other theories posit that planet assembly at small orbital
separations may be common. Here we report on a newly-born, transiting planet
orbiting its star every 5.4 days. The planet is 50 per cent larger than
Neptune, and its mass is less than 3.6 times Jupiter (at 99.7 per cent
confidence), with a true mass likely to be within a factor of several of
Neptune's. The 5-10 million year old star has a tenuous dust disk extending
outwards from about 2 times the Earth-Sun separation, in addition to the large
planet located at less than one-twentieth the Earth-Sun separation.


title: Two-stage algorithms for covering array construction

abstract:
  Modern software systems often consist of many different components, each with
a number of options. Although unit tests may reveal faulty options for
individual components, functionally correct components may interact in
unforeseen ways to cause a fault. Covering arrays are used to test for
interactions among components systematically. A two-stage framework, providing
a number of concrete algorithms, is developed for the efficient construction of
covering arrays. %Our framework divides the construction in two stages. In the
first stage, a time and memory efficient randomized algorithm covers most of
the interactions. In the second stage, a more sophisticated search covers the
remainder in relatively few tests. In this way, the storage limitations of the
sophisticated search algorithms are avoided; hence the range of the number of
components for which the algorithm can be applied is extended, without
increasing the number of tests. Many of the framework instantiations can be
tuned to optimize a memory-quality trade-off, so that fewer tests can be
achieved using more memory. The algorithms developed outperform the currently
best known methods when the number of components ranges from 20 to 60, the
number of options for each ranges from 3 to 6, and $t$-way interactions are
covered for $t\in \{5,6\}$. In some cases a reduction in the number of tests by
more than $50\%$ is achieved.


title: The MAGNEX spectrometer: results and perspectives

abstract:
  This article discusses the main achievements and future perspectives of the
MAGNEX spectrometer at the INFN-LNS laboratory in Catania (Italy). MAGNEX is a
large acceptance magnetic spectrometer for the detection of the ions emitted in
nuclear collisions below Fermi energy. In the first part of the paper an
overview of the MAGNEX features is presented. The successful application to the
precise reconstruction of the momentum vector, to the identification of the ion
masses and to the determination of the transport efficiency is demonstrated by
in-beam tests. In the second part, an overview of the most relevant scientific
achievements is given. Results from nuclear elastic and inelastic scattering as
well as from transfer and charge exchange reactions in a wide range of masses
of the colliding systems and incident energies are shown. The role of MAGNEX in
solving old and new puzzles in nuclear structure and direct reaction mechanisms
is emphasized. One example is the recently observed signature of the long
searched Giant Pairing Vibration. Finally, the new challenging opportunities to
use MAGNEX for future experiments are briefly reported. In particular, the use
of double charge exchange reactions toward the determination of the nuclear
matrix elements entering in the expression of the half-life of neutrinoless
double beta decay is discussed. The new NUMEN project of INFN, aiming at these
investigations, is introduced. The challenges connected to the major technical
upgrade required by the project in order to investigate rare processes under
high fluxes of detected heavy ions are outlined.