title: Expanding plasmas from Anti de Sitter black holes

abstract:
  We introduce a new foliation of AdS$_5$ black holes such that the conformal
boundary takes the form of a $4$-dimensional FLRW spacetime with scale factor
$a(t)$. The foliation employs Eddington-Finkelstein-like coordinates and is
applicable to a large class of AdS black holes, supported by matter fields or
not, considerably extending previous efforts in the literature. We argue that
the holographic dual picture of a CFT plasma on a FLRW background provides an
interesting prototype to study the nonequilibrium dynamics of expanding plasmas
and use holographic renormalization to extract the renormalized energy-momentum
tensor of the dual plasma. We illustrate the procedure for three black holes of
interest, namely AdS-Schwarzschild, AdS-Gauss-Bonnet, and
AdS-Reissner-Nordstr\"om. For the latter, as a by-product, we show that the
nonequilibrium dynamics of a CFT plasma subject to a quench in the chemical
potential (i.e., a time-dependent chemical potential) resembles a cosmological
evolution with the scale factor $a(t)$ being inversely related to the quench
profile.


title:
Quantum annealing with a network of all-to-all connected, two-photon
  driven Kerr nonlinear oscillators

abstract:
  Quantum annealing aims to solve combinatorial optimization problems mapped on
to Ising interactions between quantum spins. A critical factor that limits the
success of a quantum annealer is its sensitivity to noise, and intensive
research is consequently focussed towards developing noise-resilient annealers.
Here we propose a new paradigm for quantum annealing with a scalable network of
all-to-all connected, two-photon driven Kerr-nonlinear resonators. Each of
these resonators encode an Ising spin in a robust degenerate subspace formed by
two coherent states of opposite phases. The fully-connected optimization
problem is mapped onto local fields driving the resonators, which are
themselves connected by local four-body interactions. We describe an adiabatic
annealing protocol in this system and analyze its performance in the presence
of photon loss. Numerical simulations indicate substantial resilience to this
noise channel, making it a promising platform for implementing a large scale
quantum Ising machine. Finally, we propose a realistic implementation of this
scheme in circuit QED.


title:
Stochastic win-stay-lose-shift strategy with dynamic aspirations in
  evolutionary social dilemmas

abstract:
  In times of plenty expectations rise, just as in times of crisis they fall.
This can be mathematically described as a Win-Stay-Lose-Shift strategy with
dynamic aspiration levels, where individuals aspire to be as wealthy as their
average neighbor. Here we investigate this model in the realm of evolutionary
social dilemmas on the square lattice and scale-free networks. By using the
master equation and Monte Carlo simulations, we find that cooperators coexist
with defectors in the whole phase diagram, even at high temptations to defect.
We study the microscopic mechanism that is responsible for the striking
persistence of cooperative behavior and find that cooperation spreads through
second-order neighbors, rather than by means of network reciprocity that
dominates in imitation-based models. For the square lattice the master equation
can be solved analytically in the large temperature limit of the Fermi
function, while for other cases the resulting differential equations must be
solved numerically. Either way, we find good qualitative agreement with the
Monte Carlo simulation results. Our analysis also reveals that the evolutionary
outcomes are to a large degree independent of the network topology, including
the number of neighbors that are considered for payoff determination on
lattices, which further corroborates the local character of the microscopic
dynamics. Unlike large-scale spatial patterns that typically emerge due to
network reciprocity, here local checkerboard-like patterns remain virtually
unaffected by differences in the macroscopic properties of the interaction
network.


title:
Sea-level projections representing deeply uncertain ice-sheet
  contributions

abstract:
  Future sea-level rise poses nontrivial risks for many coastal communities.
Managing these risks often relies on consensus projections like those provided
by the IPCC. Yet, there is a growing awareness that the surrounding
uncertainties may be much larger than typically perceived. Recently published
sea-level projections appear widely divergent and highly sensitive to
non-trivial model choices and the West Antarctic Ice Sheet (WAIS) may be much
less stable than previously believed, enabling a rapid disintegration. In
response, some agencies have already announced to update their projections
accordingly. Here, we present a set of probabilistic sea-level projections that
approximate deeply uncertain WAIS contributions. The projections aim to inform
robust decisions by clarifying the sensitivity to non-trivial or controversial
assumptions. We show that the deeply uncertain WAIS contribution can dominate
other uncertainties within decades. These deep uncertainties call for the
development of robust adaptive strategies. These decision-making needs, in
turn, require mission-oriented basic science, for example about potential
signposts and the maximum rate of WAIS induced sea-level changes.


title:
Not a Copernican observer: biased peculiar velocity statistics in the
  local Universe

abstract:
  We assess the effect of the local large scale structure on the estimation of
two-point statistics of the observed radial peculiar velocities of galaxies. A
large N-body simulation is used to examine these statistics from the
perspective of random observers as well as "Local Group (LG)-like" observers
conditioned to reside in an environment resembling the observed universe within
20 Mpc. The local environment systematically distorts the shape and amplitude
of velocity statistics with respect to ensemble-averaged measurements made by a
Copernican (random) observer. The Virgo cluster has the most significant
impact, introducing large systematic deviations in all the statistics. For a
simple "top-hat" selection function, an idealized survey extending to $\sim
160h^{-1}\,{\rm Mpc}$ or deeper is needed to completely mitigate the effects of
the local environment. Using shallower catalogues leads to systematic
deviations of the order of $50$ to $200\%$ depending on the scale considered.
For a flat redshift distribution similar to the one of the CosmicFlows-3
survey, the deviations are even more prominent in both the shape and amplitude
at all separations considered $({\stackrel{<}{{}_\sim}} 100h^{-1}\,{\rm Mpc})$.
Conclusions based on statistics calculated without taking into account the
impact of the local environment should be revisited.


title:
Threshold Singularities of the Spectral Shift Function for a Half-Plane
  Magnetic Hamiltonian

abstract:
  We consider the Schr\"odinger operator with constant magnetic field defined
on the half-plane with a Dirichlet boundary condition, $H_0$, and a decaying
electric perturbation $V$. We analyze the spectral density near the Landau
levels, which are thresholds in the spectrum of $H_0,$ by studying the Spectral
Shift Function (SSF) associated to the pair $(H_0+V,{H_0})$. For perturbations
of a fixed sign, we estimate the SSF in terms of the eigenvalue counting
function for certain compact operators. If the decay of $V$ is power-like, then
using pseudodifferential analysis, we deduce that there are singularities at
the thresholds and we obtain the corresponding asymptotic behavior of the SSF.
Our technique gives also results for the Neumann boundary condition.


title: UV complete composite Higgs models

abstract:
  We study confining gauge theories with fermions vectorial under the SM that
produce a Higgs doublet as a Nambu-Goldstone boson. The vacuum misalignment
required to break the electro-weak symmetry is induced by an elementary Higgs
doublet with Yukawa couplings to the new fermions. The physical Higgs is a
linear combination of elementary and composite Higgses while the SM fermions
remain elementary. The full theory is renormalizable and the SM Yukawa
couplings are generated from the ones of the elementary Higgs allowing to
eliminate all flavour problems but with interesting effects for Electric Dipole
Moments of SM particles. We also discuss how ideas on the relaxation of the
electro-weak scale could be realised within this framework.


title: Fractional quantum Hall states of bosons on cones

abstract:
  Motivated by a recent experiment which synthesizes Landau levels for photons
on cones [Schine {\em et al.}, Nature 534, 671 (2016)], and more generally the
interest in understanding gravitational responses of quantum Hall states, we
study fractional quantum Hall states of bosons on cones. A variety of trial
wave functions for conical systems are constructed and compared with exact
diagonalization results. The tip of a cone is a localized geometrical defect
with singular curvature which can modify the density profiles of quantum Hall
states. The density profiles on cones can be used to extract some universal
information about quantum Hall states. The values of certain quantities are
computed numerically using the density profiles of some quantum Hall states and
they agree with analytical predictions.


title:
Tree based machine learning framework for predicting ground state
  energies of molecules

abstract:
  We present an application of the boosted regression tree algorithm for
predicting ground state energies of molecules made up of C, H, N, O, P, and S
(CHNOPS). The PubChem chemical compound database has been incorporated to
construct a dataset of 16,242 molecules, whose electronic ground state energies
have been computed using density functional theory. This dataset is used to
train the boosted regression tree algorithm, which allows a computationally
efficient and accurate prediction of molecular ground state energies.
Predictions from boosted regression trees are compared with neural network
regression, a widely used method in the literature, and shown to be more
accurate with significantly reduced computational cost. The performance of the
regression model trained using the CHNOPS set is also tested on a set of
distinct molecules that contain additional Cl and Si atoms. It is shown that
the learning algorithms lead to a rich and diverse possibility of applications
in molecular discovery and materials informatics.


title: Proof of Bekenstein-Mukhanov ansatz in loop quantum gravity

abstract:
  A simple proof of Bekenstein-Mukhanov(BM) ansatz is given within the loop
quantum gravity(LQG) framework. The macroscopic area of an equilibrium black
hole horizon indeed manifests a linear quantization. The quantum number
responsible for this discreteness of the macroscopic area has a physical
meaning in the LQG framework, unlike the ad hoc one that remained unexplained
in BM ansatz.


title: Exact multiplicity of solutions for some semilinear Dirichlet problems

abstract:
  The classical result of A. Ambrosetti and G. Prodi [1], in the form of M.S.
Berger and E. Podolak [4], gives the exact number of solutions for the problem
\[ \Delta u+g(u)= \mu \phi _1(x)+e(x) \;\; \mbox{in $D$} , \;\; u=0 \;\;
\mbox{on $\partial D$} \,, \] depending on the real parameter $\mu$, for a
class of convex $g(u)$, and $\int _D e(x) \phi _1(x)\, dx=0$ (where $\phi
_1(x)>0$ is the principal eigenfunction of the Laplacian on $D$, and $D \subset
R^n$ is a smooth domain). By considering generalized harmonics, we give a
similar result for the problem \[ \Delta u+g(u)= \mu f(x) \;\; \mbox{in $D$} ,
\;\; u=0 \;\; \mbox{on $\partial D$} \,, \] with $f(x)>0$. Such problems occur,
for example, in "fishing" applications that we discuss, and propose a new
model.
  Our approach also produces a very simple proof of the anti-maximum principle
of Ph. Cl\'{e}ment and L.A. Peletier [5].


title:
Social Network Processes in the Isabelle and Coq Theorem Proving
  Communities

abstract:
  We identify the main actors in the Isabelle and Coq communities and describe
how they affect and influence their peers. This work explores selected
foundations of social networking analysis that we expect to be useful in the
context of the ProofPeer project, which is developing a new model for
interactive theorem proving based on collaboration and social interactions.


title:
Optimal Placement and Sizing of Distributed Battery Storage in Low
  Voltage Grids using Receding Horizon Control Strategies

abstract:
  In this paper we present a novel methodology for leveraging Receding Horizon
Control (RHC), also known as Model Predictive Control (MPC) strategies for
distributed battery storage in a planning problem using a Benders decomposition
technique. Longer prediction horizons lead to better storage placement
strategies but also higher computational complexity that can quickly become
computationally prohibitive. The here proposed MPC strategy in conjunction with
a Benders decomposition technique effectively reduces the computational
complexity to a manageable level. We use the CIGRE low voltage (LV) benchmark
grid as a case study for solving an optimal placement and sizing problem for
different control strategies with different MPC prediction horizons. The
objective of the MPC strategy is to maximize the photovoltaic (PV) utilization
and minimize battery degradation in a local residential area, while satisfying
all grid constraints. For this case study we show that the economic value of
battery storage is higher when using MPC based storage control strategies than
when using heuristic storage control strategies, because MPC strategies
explicitly exploit the value of forecast information. The economic merit of
this approach can be further increased by explicitly incorporating a battery
degradation model in the MPC strategy.


title:
Discovery of coherent pulsations from the Ultraluminous X-ray Source NGC
  7793 P13

abstract:
  We report the detection of coherent pulsations from the ultraluminous X-ray
source NGC 7793 P13. The ~0.42s nearly sinusoidal pulsations were initially
discovered in broadband X-ray observations using XMM-Newton and NuSTAR taken in
2016. We subsequently also found pulsations in archival XMM-Newton data taken
in 2013 and 2014. The significant (>>5 sigma) detection of coherent pulsations
demonstrates that the compact object in P13 is a neutron star with an observed
peak luminosity of ~1e40 erg/s (assuming isotropy), well above the Eddington
limit for a 1.4 M_sun accretor. This makes P13 the second ultraluminous X-ray
source known to be powered by an accreting neutron star. The pulse period
varies between epochs, with a slow but persistent spin up over the 2013-2016
period. This spin-up indicates a magnetic field of B ~ 1.5e12 G, typical of
many accreting pulsars. The most likely explanation for the extreme luminosity
is a high degree of beaming, however this is difficult to reconcile with the
sinusoidal pulse profile.


title: Ulrich Bundles on Veronese surfaces

abstract:
  We prove that every Ulrich bundle on the Veronese surface has a resolution in
terms of twists of the trivial bundle over $\mathbb{P}^{2}$. Using this
classification, we prove existence results for stable Ulrich bundles over
$\mathbb{P}^{k}$ with respect to an arbitrary polarization $dH$.


title: Inferring dissipation from current fluctuations

abstract:
  Complex physical dynamics can often be modeled as a Markov jump process
between mesoscopic configurations. When jumps between mesoscopic states are
mediated by thermodynamic reservoirs, the time-irreversibility of the jump
process is a measure of the physical dissipation. We rederive a recently
introduced inequality relating the dissipation rate to current fluctuations in
jump processes. We then adapt these results to diffusion processes via a
limiting procedure, reaffirming that diffusions saturate the inequality.
Finally, we study the impact of spatial coarse-graining in a two-dimensional
model with driven diffusion. By observing fluctuations in coarse-grained
currents, it is possible to infer a lower bound on the total dissipation rate,
including the dissipation associated with hidden dynamics. The tightness of
this bound depends on how well the spatial coarse-graining detects dynamical
events that are driven by large thermodynamic forces.


title: A Fully Convolutional Neural Network for Speech Enhancement

abstract:
  In hearing aids, the presence of babble noise degrades hearing
intelligibility of human speech greatly. However, removing the babble without
creating artifacts in human speech is a challenging task in a low SNR
environment. Here, we sought to solve the problem by finding a `mapping'
between noisy speech spectra and clean speech spectra via supervised learning.
Specifically, we propose using fully Convolutional Neural Networks, which
consist of lesser number of parameters than fully connected networks. The
proposed network, Redundant Convolutional Encoder Decoder (R-CED), demonstrates
that a convolutional network can be 12 times smaller than a recurrent network
and yet achieves better performance, which shows its applicability for an
embedded system: the hearing aids.


title: Strongly regular graphs from orthogonal groups $O^+(6,2)$ and $O^-(6,2)$

abstract:
  In this paper we construct all strongly regular graphs, with at most 600
vertices, admitting a transitive action of the orthogonal group $O^+(6,2)$ or
$O^-(6,2)$. Consequently, we prove the existence of strongly regular graphs
with parameters (216,40,4,8) and (540,187,58,68). We also construct a strongly
regular graph with parameters (540,224,88,96) that was to the best of our
knowledge previously unknown. Further, we show that under certain conditions an
orbit matrix $M$ of a strongly regular graph $\Gamma$ can be used to define a
new strongly regular graph $\widetilde{\Gamma}$, where the vertices of the
graph $\widetilde{\Gamma}$ correspond to the orbits of $\Gamma$ (the rows of
$M$). We show that some of the obtained graphs are related to each other in a
way that one can be constructed from an orbit matrix of the other.


title: Clifford algebras meet tree decompositions

abstract:
  We introduce the Non-commutative Subset Convolution - a convolution of
functions useful when working with determinant-based algorithms. In order to
compute it efficiently, we take advantage of Clifford algebras, a
generalization of quaternions used mainly in the quantum field theory.
  We apply this tool to speed up algorithms counting subgraphs parameterized by
the treewidth of a graph. We present an $O^*((2^\omega + 1)^{tw})$-time
algorithm for counting Steiner trees and an $O^*((2^\omega + 2)^{tw})$-time
algorithm for counting Hamiltonian cycles, both of which improve the previously
known upper bounds. The result for Steiner Tree also translates into a
deterministic algorithm for Feedback Vertex Set. All of these constitute the
best known running times of deterministic algorithms for decision versions of
these problems and they match the best obtained running times for pathwidth
parameterization under assumption $\omega = 2$.


title: Convergence of Regression Adjusted Approximate Bayesian Computation

abstract:
  We present asymptotic results for the regression-adjusted version of
approximate Bayesian computation introduced by Beaumont(2002). We show that for
an appropriate choice of the bandwidth, regression adjustment will lead to a
posterior that, asymptotically, correctly quantifies uncertainty. Furthermore,
for such a choice of bandwidth we can implement an importance sampling
algorithm to sample from the posterior whose acceptance probability tends to
unity as the data sample size increases. This compares favourably to results
for standard approximate Bayesian computation, where the only way to obtain a
posterior that correctly quantifies uncertainty is to choose a much smaller
bandwidth; one for which the acceptance probability tends to zero and hence for
which Monte Carlo error will dominate.


title: The Timescale-Dependent Color Variability of Quasars Viewed with GALEX

abstract:
  In recent work done by Sun et. al., the color variation of quasars, namely
the bluer-when-brighter trend, was found to be timescale-dependent using SDSS
$g/r$ band light curves in the Stripe 82. Such timescale dependence, i.e.,
bluer variation at shorter timescales, supports the thermal fluctuation origin
of the UV/optical variation in quasars, and can be well modeled with the
inhomogeneous accretion disk model. In this paper, we extend the study to much
shorter wavelengths in the rest frame (down to extreme UV), using GALaxy
Evolution eXplorer (GALEX) photometric data of quasars collected in two
ultraviolet bands (near-UV and far-UV). We develop Monte-Carlo simulations to
correct possible biases due to the considerably larger photometric
uncertainties in GALEX light curves (particularly in far-UV, comparing with
SDSS $g/r$ bands), which otherwise could produce artificial results. We
securely confirm the previously discovered timescale dependence of the color
variability with independent datasets and at shorter wavelengths. We further
find the slope of the correlation between the amplitude of color variation and
timescale however appears even steeper than that predicted by the inhomogeneous
disk model, which assumes that disk fluctuations follow damped random walk
process. In line with the much flatter structure function observed in far-UV
comparing with that at longer wavelengths, this implies deviation from DRW
process in the inner disk where rest frame extreme UV radiation is produced.


title: Hyperaccreting black holes in galactic nuclei

abstract:
  The rate at which matter flows into a galactic nucleus during early phases of
galaxy evolution can sometimes exceed the Eddington limit of the growing
central black hole by several orders of magnitude. We discuss the necessary
conditions for the black hole to actually accrete this matter at such a high
rate, and consider the observational appearance and detectability of a
hyperaccreting black hole. In order to be accreted at a hyper-Eddington rate,
the infalling gas must have a sufficiently low angular momentum. Although most
of the gas is accreted, a significant fraction accumulates in an optically
thick envelope with luminosity $\sim L_{\rm Edd}$, probably pierced by jets of
much higher power. If $\dot M > 10^3 \dot M_{\rm Edd}$, the envelope spectrum
resembles a blackbody with a temperature of a few thousand K, but for lower
(but still hyper-Eddington) accretion rates the spectrum becomes a very dilute
and hard Wien spectrum. We consider the likelihood of various regimes of
hyperaccretion, and discuss its possible observational signatures.


title:
Confronting lepton flavor universality violation in B decays with
  high-$p_T$ tau lepton searches at LHC

abstract:
  We confront the indications of lepton flavor universality (LFU) violation
observed in semi-tauonic $B$ meson decays with new physics (NP) searches using
high $p_T$ tau leptons at the LHC. Using effective field theory arguments we
correlate possible non-standard contributions to semi-tauonic charged currents
with the $\tau^+ \tau^-$ signature at high energy hadron colliders. Several
representative standard model extensions put forward to explain the anomaly are
examined in detail: (i) weak triplet of color-neutral vector resonances, (ii)
second Higgs doublet and (iii) scalar or (iv) vector leptoquark. We find that,
in general, $\tau^+ \tau^-$ searches pose a serious challenge to NP
explanations of the LFU anomaly. Recasting existing 8 TeV and 13 TeV LHC
analyses, stringent limits are set on all considered simplified models. Future
projections of the $\tau^+ \tau^-$ constraints as well as caveats in
interpreting them within more elaborate models are also discussed.


title: NEWS: the near-infrared Echelle for wideband spectroscopy

abstract:
  We present an updated optical and mechanical design of NEWS: the
Near-infrared Echelle for Wide-band Spectroscopy (formerly called HiJaK: the
High-resolution J, H and K spectrometer), a compact, high-resolution,
near-infrared spectrometer for 5-meter class telescopes. NEWS provides a
spectral resolution of 60,000 and covers the full 0.8-2.5 micron range in 5
modes. We adopt a compact, lightweight, monolithic design and developed NEWS to
be mounted to the instrument cube at the Cassegrain focus of the the new
4.3-meter Discovery Channel Telescope.


title:
Growth and proline content in NaCl stressed plants of annual medic
  species

abstract:
  Wild populations of Medicago ciliaris and Medicago polymorpha were subjected
to four salt treatments 0, 50, 100 and 150 mM NaCl, plant growth and proline
concentration in leaves were assessed. The analyzed data revealed significant
variability in salt response within and between the two species, depending on
the salinity level. It was found that high NaCl concentrations affected all the
growth parameters. However, the reduction was more important at higher NaCl
concentrations and the highest reduction was obtained for the populations of
Medicago polymorpha where it reached around 90% in root length at 150 mM NaCl
for Pmar. The Tunisian population of Medicago ciliaris, prospected on soils
affected by salinity, was the best tolerant in all ecotypes studied in this
work. This population, exhibits a particular adaptability to salt environment
at both germination and seedling stage. Furthermore, the correlation among the
studied plants sensitivity and leaf proline concentration showed that high
proline contents were related to their reactivity to salt. Consequently, it
appeared that proline biosynthesis occurred presumably as a consequence of
disturbance in cell homoeostasis and reflected poor performance and greater
damage in response to salt stress. These findings indicated that this osmolytes
content may be used as another useful criterion to differentiate salt-tolerant
from salt sensitive plant in annual medics.


title:
Quiescence correlates strongly with directly-measured black hole mass in
  central galaxies

abstract:
  Roughly half of all stars reside in galaxies without significant ongoing star
formation. However, galaxy formation models indicate that it is energetically
challenging to suppress the cooling of gas and the formation of stars in
galaxies that lie at the centers of their dark matter halos. In this Letter, we
show that the dependence of quiescence on black hole and stellar mass is a
powerful discriminant between differing models for the mechanisms that suppress
star formation. Using observations of 91 star-forming and quiescent central
galaxies with directly-measured black hole masses, we find that quiescent
galaxies host more massive black holes than star-forming galaxies with similar
stellar masses. This observational result is in qualitative agreement with
models that assume that effective, more-or-less continuous AGN feedback
suppresses star formation, strongly suggesting the importance of the black hole
in producing quiescence in central galaxies.


title: Gravitational-wave cosmography with LISA and the Hubble tension

abstract:
  We propose that stellar-mass binary black holes like GW150914 will become a
tool to explore the local Universe within ~100Mpc in the era of the Laser
Interferometer Space Antenna (LISA). High calibration accuracy and annual
motion of LISA could enable us to localize up to ~60 binaries more accurately
than the error volume of ~100Mpc^3 without electromagnetic counterparts under
moderately optimistic assumptions. This accuracy will give us a fair chance to
determine the host object solely by gravitational waves. By combining the
luminosity distance extracted from gravitational waves with the cosmological
redshift determined from the host, the local value of the Hubble parameter will
be determined up to a few % without relying on the empirically constructed
distance ladder. Gravitational-wave cosmography would pave the way for
resolution of the disputed Hubble tension, where the local and global
measurements disagree in the value of the Hubble parameter at 3.4sigma level,
which amounts to ~9%.


title:
Gravitational wave and collider implications of electroweak baryogenesis
  aided by non-standard cosmology

abstract:
  We consider various models realizing baryogenesis during the electroweak
phase transition (EWBG). Our focus is their possible detection in future
collider experiments and possible observation of gravitational waves emitted
during the phase transition. We also discuss the possibility of a non-standard
cosmological history which can facilitate EWBG. We show how acceptable
parameter space can be extended due to such a modification and conclude that
next generation precision experiments such as the ILC will be able to confirm
or falsify many models realizing EWBG. We also show that, in general, collider
searches are a more powerful probe than gravitational wave searches. However,
observation of a deviation from the SM without any hints of gravitational waves
can point to models with modified cosmological history that generically enable
EWBG with weaker phase transition and thus, smaller GW signals.


title: Orbifold Reduction and 2d (0,2) Gauge Theories

abstract:
  We introduce Orbifold Reduction, a new method for generating $2d$ $(0,2)$
gauge theories associated to D1-branes probing singular toric Calabi-Yau
4-folds starting from $4d$ $\mathcal{N}=1$ gauge theories on D3-branes probing
toric Calabi-Yau 3-folds. The new procedure generalizes dimensional reduction
and orbifolding. In terms of T-dual configurations, it generates brane brick
models starting from brane tilings. Orbifold reduction provides an agile
approach for generating $2d$ $(0,2)$ theories with a brane realization. We
present three practical applications of the new algorithm: the connection
between $4d$ Seiberg duality and $2d$ triality, a combinatorial method for
generating theories related by triality and a $2d$ $(0,2)$ generalization of
the Klebanov-Witten mass deformation.


title:
The Chandra Survey of Extragalactic Sources in the 3CR Catalog: X-ray
  Emission from Nuclei, Jets, and Hotspots in the Chandra Archival Observations

abstract:
  As part of our program to build a complete radio and X-ray database of all
the 3CR extragalactic radio sources, we present an analysis of 93 sources for
which Chandra archival data are available. Most of these sources have been
already published. Here we provide a uniform re-analysis and present nuclear
X-ray fluxes and X-ray emission associated with radio jet knots and hotspots
using both publicly available radio images and new radio images that have been
constructed from data available in the VLA archive. For about 1/3 of the
sources in the selected sample a comparison between the Chandra and the radio
observations was not reported in the literature: we find X-ray detections of 2
new radio jet knots and 17 hotspots. We also report the X-ray detection of
extended emission from the intergalactic medium of 15 galaxy clusters, two of
which were most likely unknown previously.


title:
Analytic treatment of the system of a Kerr-Newman black hole and a
  charged massive scalar field

abstract:
  Charged rotating Kerr-Newman black holes are known to be superradiantly
unstable to perturbations of charged massive bosonic fields whose proper
frequencies lie in the bounded regime $0 < \omega < \text{min}
\{\omega_{\text{c}} \equiv m \Omega_{\text{H}} + q\Phi_{\text{H}},\mu\}$ [here
$\{\Omega_{\text{H}}, \Phi_{\text{H}}\}$ are respectively the angular velocity
and electric potential of the Kerr-Newman black hole, and $\{m,q,\mu\}$ are
respectively the azimuthal harmonic index, the charge coupling constant, and
the proper mass of the field]. In this paper we study analytically the complex
resonance spectrum which characterizes the dynamics of linearized charged
massive scalar fields in a near-extremal Kerr-Newman black-hole spacetime.
Interestingly, it is shown that near the critical frequency $\omega_{\text{c}}$
for superradiant amplification and in the eikonal large-mass regime, the
superradiant instability growth rates of the explosive scalar fields are
characterized by a non-trivial (non-monotonic) dependence on the dimensionless
charge-to-mass ratio $q/\mu$. In particular, for given parameters $\{M,Q, J\}$
of the central Kerr-Newman black hole, we determine analytically the optimal
charge-to-mass ratio $q/\mu$ of the explosive scalar field which {\it
maximizes} the growth rate of the superradiant instabilities in the composed
Kerr-Newman-black-hole-charged-massive-scalar-field system.


title: What galaxy masses perturb the local cosmic expansion?

abstract:
  We use 12 cosmological $N$-body simulations of Local Group systems (the
Apostle models) to inspect the relation between the virial mass of the main
haloes ($M_{\rm vir,1}$ and $M_{\rm vir,2}$), the mass derived from the
relative motion of the halo pair ($M_{\rm tim}$), and that inferred from the
local Hubble flow ($M_{\rm lhf}$). We show that within the Spherical Collapse
Model (SCM), the correspondence between the three mass estimates is exact, i.e.
$M_{\rm lhf}=M_{\rm tim}=M_{\rm vir,1}+M_{\rm vir,2}$. However, comparison with
Apostle simulations reveals that, contrary to what the SCM states, a relatively
large fraction of the mass that perturbs the local Hubble flow and drives the
relative trajectory of the main galaxies is not contained within $R_{\rm vir}$,
and that the amount of "extra-virial" mass tends to increase in galaxies with a
slow accretion rate. In contrast, modelling the peculiar velocities around the
Local Group returns an unbiased constraint on the virial mass ratio of the main
galaxy pair. Adopting the outer halo profile found in $N$-body simulations,
which scales as $\rho\sim R^{-4}$ at $R\gtrsim R_{\rm vir}$, indicates that the
galaxy masses perturbing the local Hubble flow roughly correspond to the
asymptotically-convergent (total) masses of the individual haloes. We show that
estimates of $M_{\rm vir}$ based on the dynamics of tracers at $R\gg R_{\rm
vir}$ require a priori information on the internal matter distribution and the
growth rate of the main galaxies, both of which are typically difficult to
quantify.


title: X-ray and Ultraviolet Properties of AGN in Nearby Dwarf Galaxies

abstract:
  We present new Chandra X-ray Observatory and Hubble Space Telescope
observations of eight optically selected broad-line AGN candidates in nearby
dwarf galaxies ($z<0.055$). Including archival Chandra observations of three
additional sources, our sample contains all ten galaxies from Reines et al.
(2013) with both broad H$\alpha$ emission and narrow-line AGN ratios (6 AGNs, 4
Composites), as well as one low-metallicity dwarf galaxy with broad H$\alpha$
and narrow-line ratios characteristic of star formation. All eleven galaxies
are detected in X-rays. Nuclear X-ray luminosities range from $L_{0.5-7
\rm{keV}}\approx5\times10^{39}$ to $1\times10^{42}$ $\rm{erg}\rm{s^{-1}}$. In
all cases except for the star forming galaxy, the nuclear X-ray luminosities
are significantly higher than would be expected from X-ray binaries, providing
strong confirmation that AGN and composite dwarf galaxies do indeed host
actively accreting BHs. Using our estimated BH masses (which range from
$\sim7\times10^{4}-1\times10^{6}~M_{\odot}$), we find inferred Eddington
fractions ranging from $\sim0.1-50\%$, i.e. comparable to massive broad-line
quasars at higher redshift. We use the HST imaging to determine the ratio of
ultraviolet to X-ray emission for these AGN, finding that they appear to be
less X-ray luminous with respect to their UV emission than more massive quasars
(i.e. $\alpha_{\rm OX}$ values an average of 0.36 lower than expected based on
the relation between $\alpha_{\rm OX}$ and $2500{\rm \AA}$ luminosity).
Finally, we discuss our results in the context of different accretion models
onto nuclear BHs.


title: Improved jet substructure methods: Y-splitter and variants with grooming

abstract:
  It has recently been demonstrated with Monte Carlo studies that combining the
well-known Y-splitter and trimming techniques gives rise to important gains in
the signal significance achievable for boosted electroweak boson tagging at
high $p_t$. Here we carry out analytical calculations that explain these
findings from first principles of QCD both for grooming via trimming and via
the modified mass-drop tagger (mMDT). We also suggest modifications to
Y-splitter itself, which result in great simplifications to the analytical
results both for pure Y-splitter as well as its combination with general
grooming methods. The modifications also lead to further performance gains,
while making the results largely independent of choice of groomer. We discuss
the implications of these findings in the broader context of optimal methods
for boosted object studies at hadron colliders.


title:
The Gaia-ESO Survey: Lithium depletion in the Gamma Velorum cluster and
  inflated radii in low-mass pre-main-sequence stars

abstract:
  We show that non-magnetic models for the evolution of pre-main-sequence (PMS)
stars *cannot* simultaneously describe the colour-magnitude diagram (CMD) and
the pattern of lithium depletion seen in the cluster of young, low-mass stars
surrounding $\gamma^2$ Velorum. The age of 7.5+/-1 Myr inferred from the CMD is
much younger than that implied by the strong Li depletion seen in the cluster
M-dwarfs and the Li depletion occurs at much redder colours than predicted. The
epoch at which a star of a given mass depletes its Li and the surface
temperature of that star are both dependent on its radius. We demonstrate that
if the low-mass stars have radii ~10 per cent larger at a given mass and age,
then both the CMD and Li depletion pattern of the Gamma Vel cluster are
explained at a common age of 18-21 Myr. This radius inflation could be produced
by some combination of magnetic suppression of convection and extensive cool
starspots. Models that incorporate radius inflation suggest that PMS stars
similar to those in the Gamma Vel cluster, in the range 0.2<M/Msun<0.7, are at
least a factor of two older and ~7 per cent cooler than previously thought and
that their masses are much larger (by >30 per cent) than inferred from
conventional, non-magnetic models in the Hertzsprung-Russell diagram.
Systematic changes of this size may be of great importance in understanding the
evolution of young stars, disc lifetimes and the formation of planetary
systems.


title: Coulomb Artifacts and Bottomonium Hyperfine Splitting in Lattice NRQCD

abstract:
  We study the role of the lattice artifacts associated with the Coulomb
binding effects in the analysis of the heavy quarkonium within lattice NRQCD.
We find that a "naive" perturbative matching generates spurious linear Coulomb
artifacts, which result in a large systematic error in the lattice predictions
for the heavy quarkonium spectrum. This effect is responsible, in particular,
for the discrepancy between the recent determinations of the bottomonium
hyperfine splitting in the radiatively improved lattice NRQCD [1, 2]. We show
that the correct matching procedure which provides full control over
discretization errors is based on the asymptotic expansion of the lattice
theory about the continuum limit, which gives
$M_{\Upsilon(1S)}-M_{\eta_b(1S)}=52.9\pm 5.5~{\rm MeV}$ [1].


title: Input Convex Neural Networks

abstract:
  This paper presents the input convex neural network architecture. These are
scalar-valued (potentially deep) neural networks with constraints on the
network parameters such that the output of the network is a convex function of
(some of) the inputs. The networks allow for efficient inference via
optimization over some inputs to the network given others, and can be applied
to settings including structured prediction, data imputation, reinforcement
learning, and others. In this paper we lay the basic groundwork for these
models, proposing methods for inference, optimization and learning, and analyze
their representational power. We show that many existing neural network
architectures can be made input-convex with a minor modification, and develop
specialized optimization algorithms tailored to this setting. Finally, we
highlight the performance of the methods on multi-label prediction, image
completion, and reinforcement learning problems, where we show improvement over
the existing state of the art in many cases.


title:
On the Late-Time Behavior of Virasoro Blocks and a Classification of
  Semiclassical Saddles

abstract:
  Recent work has demonstrated that black hole thermodynamics and information
loss/restoration in AdS$_3$/CFT$_2$ can be derived almost entirely from the
behavior of the Virasoro conformal blocks at large central charge, with
relatively little dependence on the precise details of the CFT spectrum or OPE
coefficients. Here, we elaborate on the non-perturbative behavior of Virasoro
blocks by classifying all `saddles' that can contribute for arbitrary values of
external and internal operator dimensions in the semiclassical large central
charge limit. The leading saddles, which determine the naive semiclassical
behavior of the Virasoro blocks, all decay exponentially at late times, and at
a rate that is independent of internal operator dimensions. Consequently, the
semiclassical contribution of high-energy states does not resolve a well-known
version of the information loss problem in AdS$_3$. However, we identify two
infinite classes of sub-leading saddles, and one of these classes does not
decay at late times.


title:
A posteriori error estimates for a Virtual Elements Method for the
  Steklov eigenvalue problem

abstract:
  The paper deals with the a posteriori error analysis of a virtual element
method for the Steklov eigenvalue problem. The virtual element method has the
advantage of using general polygonal meshes, which allows implementing very
efficiently mesh refinement strategies. We introduce a residual type a
posteriori error estimator and prove its reliability and efficiency. We use the
corresponding error estimator to drive an adaptive scheme. Finally, we report
the results of a couple of numerical tests, that allow us to assess the
performance of this approach.


title:
Late time cooling of neutron star transients and the physics of the
  inner crust

abstract:
  An accretion outburst onto a neutron star transient heats the neutron star's
crust out of thermal equilibrium with the core. After the outburst the crust
thermally relaxes toward equilibrium with the neutron star core and the surface
thermal emission powers the quiescent X-ray light curve. Crust cooling models
predict that thermal equilibrium of the crust will be established $\approx 1000
\, \mathrm{d}$ into quiescence. Recent observations of the cooling neutron star
transient MXB 1659-29, however, suggest that the crust did not reach thermal
equilibrium with the core on the predicted timescale and continued to cool
after $\approx 2500 \, \mathrm{d}$ into quiescence. Because the quiescent light
curve reveals successively deeper layers of the crust, the observed late time
cooling of MXB 1659-29 depends on the thermal transport in the inner crust. In
particular, the observed late time cooling is consistent with a low thermal
conductivity layer near the depth predicted for nuclear pasta that maintains a
temperature gradient between the neutron star's inner crust and core for
thousands of days into quiescence. As a result, the temperature near the
crust-core boundary remains above the critical temperature for neutron
superfluidity and a layer of normal neutrons forms in the inner crust. We find
that the late time cooling of MXB 1659-29 is consistent with heat release from
a normal neutron layer near the crust-core boundary with a long thermal time.


title:
Observational Constraints on Water Sublimation from 24 Themis and 1
  Ceres

abstract:
  Recent observations have suggested that there is water ice present on the
surfaces of 24 Themis and 1 Ceres. We present upper limits on the H$_2$O
production rate on these bodies derived using a search for [OI]6300 Angstrom
emission. For Themis, the water production is less than 4.5 $\times$ 10$^{27}$
mol s$^{-1}$, while for Ceres our derived upper limit is 4.6 $\times$ 10$^{28}$
mol s$^{-1}$. The derived limits imply a very low fraction of the surface area
of each asteroid is active ($<$ 2 $\times$ 10$^{-4}$), though this estimate
varies by as much as an order of magnitude depending on thermal properties of
the surface. This is much lower than seen for comets, which have active areas
of 10$^{-2}$ - 10$^{-1}$. We discuss possible implications for our findings on
the nature of water ice on Themis and Ceres.


title: Synthesis of Disparate Optical Imaging Data for Space Domain Awareness

abstract:
  We present a Bayesian algorithm to combine optical imaging of unresolved
objects from distinct epochs and observation platforms for orbit determination
and tracking. By propagating the non-Gaussian uncertainties we are able to
optimally combine imaging of arbitrary signal-to-noise ratios, allowing the
integration of data from low-cost sensors. Our Bayesian approach to image
characterization also allows large compression of imaging data without loss of
statistical information. With a computationally efficient algorithm to combine
multiple observation epochs and multiple telescopes, we show statistically
optimal orbit inferences.


title: Blind Detection of Ultra-faint Streaks with a Maximum Likelihood Method

abstract:
  We have developed a maximum likelihood source detection method capable of
detecting ultra-faint streaks with surface brightnesses approximately an order
of magnitude fainter than the pixel level noise. Our maximum likelihood
detection method is a model based approach that requires no a priori knowledge
about the streak location, orientation, length, or surface brightness. This
method enables discovery of typically undiscovered objects, and enables the
utilization of low-cost sensors (i.e., higher-noise data). The method also
easily facilitates multi-epoch co-addition. We will present the results from
the application of this method to simulations, as well as real low earth orbit
observations.


title:
Low Frequency Carbon Radio Recombination Lines II: The Diffuse
  Interstellar Medium

abstract:
  In the second paper of the series, we have modeled low frequency carbon radio
recombination lines (CRRL) from the interstellar medium. Anticipating the LOw
Frequency ARray (LOFAR) survey of Galactic CRRLs, we focus our study on the
physical conditions of the diffuse cold neutral medium (CNM). We have used the
improved departure coefficients computed in the first paper of the series to
calculate line-to-continuum ratios. The results show that the line width and
integrated optical depths of CRRL are sensitive probes of the electron density,
gas temperature, and the emission measure of the cloud. Furthermore, the ratio
of CRRL to the [CII] at 158 $\mu$m line is a strong function of the temperature
and density of diffuse clouds. Guided by our calculations, we analyze CRRL
observations and illustrate their use with data from the literature.


title: Deep Learning in Multi-Layer Architectures of Dense Nuclei

abstract:
  We assume that, within the dense clusters of neurons that can be found in
nuclei, cells may interconnect via soma-to-soma interactions, in addition to
conventional synaptic connections. We illustrate this idea with a multi-layer
architecture (MLA) composed of multiple clusters of recurrent sub-networks of
spiking Random Neural Networks (RNN) with dense soma-to-soma interactions, and
use this RNN-MLA architecture for deep learning. The inputs to the clusters are
first normalised by adjusting the external arrival rates of spikes to each
cluster. Then we apply this architecture to learning from multi-channel
datasets. Numerical results based on both images and sensor based data, show
the value of this novel architecture for deep learning.


title:
Crystal structure and low-energy Einstein mode in ErV$_2$Al$_{20}$
  intermetallic cage compound

abstract:
  Single crystals of a new ternary aluminide ErV$_2$Al$_{20}$ were grown using
a self-flux method. The crystal structure was determined by powder X-ray
diffraction measurements and Rietveld refinement, and physical properties were
studied by means of electrical resistivity, magnetic susceptibility and
specific heat measurements. These measurements reveal that ErV$_2$Al$_{20}$ is
a Curie-Weiss paramagnet down to 1.95 K with an effective magnetic moment
$\mu_{eff}$ = 9.27(1) $\mu_B$ and Curie-Weiss temperature $\Theta_{CW}$ =
-0.55(4) K. The heat capacity measurements show a broad anomaly at low
temperatures that is attributed to the presence of a low-energy Einstein mode
with characteristic temperature $\Theta_E$ = 44 K, approximately twice as high
as in the isostructural 'Einstein solid' VAl$_{10.1}$.


title: A Note on Permutation Binomials and Trinomials over Finite Fields

abstract:
  Let $p$ be an odd prime and $e$ be a positive integer. We completely explain
the permutation binomials and trinomials arising from the reversed Dickson
polynomials of the $(k+1)$-th kind $D_{n,k}(1,x)$ over $\mathbb{F}_{p^e}$ when
$n=p^l+2$, where $l\in \mathbb{N}$.


title:
Fixed point results for a new mapping related to mean nonexpansive
  mappings

abstract:
  Mean nonexpansive mappings were first introduced in 2007 by Goebel and Japon
Pineda and advances have been made by several authors toward understanding
their fixed point properties in various contexts. For any given $(\alpha_1,
\alpha_2)$-nonexpansive mapping $T$ of a Banach space, many of the positive
results have been derived from properties of the mapping $T_\alpha = \alpha_1 T
+ \alpha_2T^2= (\alpha_1I + \alpha_2T)\circ T$ which is nonexpansive. However,
the related mapping $T \circ (\alpha_1I + \alpha_2T)$ has not yet been studied.
In this paper, we investigate some fixed point properties of this new mapping
and discuss relationships between $(\alpha_1I + \alpha_2T)\circ T$ and
$T\circ(\alpha_1I + \alpha_2T)$.


title: Fundamental building blocks of strongly correlated wave functions

abstract:
  The calculation of realistic N-body wave functions for identical fermions is
still an open problem in physics, chemistry, and materials science, even for N
as small as two. A recently discovered fundamental algebraic structure of
many-body Hilbert space allows an arbitrary many-fermion wave function to be
written in terms of a finite number of antisymmetric functions called shapes.
Shapes naturally generalize the single-Slater-determinant form for the ground
state to more than one dimension. Their number is exactly $N!^{d-1}$ in $d$
dimensions. An efficient algorithm is described to generate all fermion shapes
in spaces of odd dimension, which improves on a recently published general
algorithm. The results are placed in the context of contemporary investigations
of strongly correlated electrons.


title: Robust Confidence Intervals in High-Dimensional Left-Censored Regression

abstract:
  This paper develops robust confidence intervals in high-dimensional and
left-censored regression. Type-I censored regression models are extremely
common in practice, where a competing event makes the variable of interest
unobservable. However, techniques developed for entirely observed data do not
directly apply to the censored observations. In this paper, we develop smoothed
estimating equations that augment the de-biasing method, such that the
resulting estimator is adaptive to censoring and is more robust to the
misspecification of the error distribution. We propose a unified class of
robust estimators, including Mallow's, Schweppe's and Hill-Ryan's one-step
estimator.
  In the ultra-high-dimensional setting, where the dimensionality can grow
exponentially with the sample size, we show that as long as the preliminary
estimator converges faster than $n^{-1/4}$, the one-step estimator inherits
asymptotic distribution of fully iterated version. Moreover, we show that the
size of the residuals of the Bahadur representation matches those of the simple
linear models, $s^{3/4 } (\log (p \vee n))^{3/4} / n^{1/4}$ -- that is, the
effects of censoring asymptotically disappear. Simulation studies demonstrate
that our method is adaptive to the censoring level and asymmetry in the error
distribution, and does not lose efficiency when the errors are from symmetric
distributions. Finally, we apply the developed method to a real data set from
the MAQC-II repository that is related to the HIV-1 study.


title: Painlev\'e II transcendents and their squares

abstract:
  We examine the relationship between the homogeneous second Painlev\'e
equation and equation ${\bf XX}$ from the master list recorded by Ince.


title: Chains conditions in algebraic lattices

abstract:
  This work studies the relationship between the chains of an algebraic lattice
and the order structure of the join-semilattice of its compact elements. The
results are presented into four chapters, each corresponding to a paper written
in collaboration with Maurice Pouzet.


title:
Liquid Water through Density-Functional Molecular Dynamics: Plane-Wave
  vs Atomic-Orbital Basis Sets

abstract:
  We determine and compare structural, dynamical, and electronic properties of
liquid water at near ambient conditions through density-functional molecular
dynamics simulations, when using either plane-wave or atomic-orbital basis
sets. In both frameworks, the electronic structure and the atomic forces are
self-consistently determined within the same theoretical scheme based on a
nonlocal density functional accounting for van der Waals interactions. The
overall properties of liquid water achieved within the two frameworks are in
excellent agreement with each other. Thus, our study supports that
implementations with plane-wave or atomic-orbital basis sets yield equivalent
results and can be used indiscriminately in study of liquid water or aqueous
solutions.


title:
Triangular Quantum Profiles: transmission probability and energy
  spectrum

abstract:
  Analytical expressions for the transition probability and the energy spectrum
of the 1D Schr\"odinger equation with position dependent mass are presented for
the triangular quantum barrier and quantum well. The transmission coefficient
is obtained by using the wave functions written in terms of the Airy's
functions and of the solutions of the Kummer's differential equation. In order
to show the validity of our analyze, an example by taking some numerical values
for GaAs heterostructure is presented.


title: Deep Quality: A Deep No-reference Quality Assessment System

abstract:
  Image quality assessment (IQA) continues to garner great interest in the
research community, particularly given the tremendous rise in consumer video
capture and streaming. Despite significant research effort in IQA in the past
few decades, the area of no-reference image quality assessment remains a great
challenge and is largely unsolved. In this paper, we propose a novel
no-reference image quality assessment system called Deep Quality, which
leverages the power of deep learning to model the complex relationship between
visual content and the perceived quality. Deep Quality consists of a novel
multi-scale deep convolutional neural network, trained to learn to assess image
quality based on training samples consisting of different distortions and
degradations such as blur, Gaussian noise, and compression artifacts.
Preliminary results using the CSIQ benchmark image quality dataset showed that
Deep Quality was able to achieve strong quality prediction performance (89%
patch-level and 98% image-level prediction accuracy), being able to achieve
similar performance as full-reference IQA methods.


title:
Measuring the match between evaluators and evaluees: Cognitive distances
  between panel members and research groups at the journal level

abstract:
  When research groups are evaluated by an expert panel, it is an open question
how one can determine the match between panel and research groups. In this
paper, we outline two quantitative approaches that determine the cognitive
distance between evaluators and evaluees, based on the journals they have
published in. We use example data from four research evaluations carried out
between 2009 and 2014 at the University of Antwerp.
  While the barycenter approach is based on a journal map, the
similarity-adapted publication vector (SAPV) approach is based on the full
journal similarity matrix. Both approaches determine an entity's profile based
on the journals in which it has published. Subsequently, we determine the
Euclidean distance between the barycenter or SAPV profiles of two entities as
an indicator of the cognitive distance between them. Using a bootstrapping
approach, we determine confidence intervals for these distances. As such, the
present article constitutes a refinement of a previous proposal that operates
on the level of Web of Science subject categories.


title: AR Sco: A White Dwarf Synchronar

abstract:
  The emission of the white dwarf-M dwarf binary AR Sco is driven by the rapid
synchronization of its white dwarf, rather than by accretion. This requires a
comparatively large magnetic field $\sim 100$ gauss at the M dwarf and $\sim
10^8$ gauss on the white dwarf, larger than the fields of most intermediate
polars but within the range of fields of known magnetic white dwarfs. The
spindown power is dissipated in the atmosphere of the M dwarf by magnetic
reconnection, accelerating particles that produce the observed synchrotron
radiation. The displacement of the optical maximum from conjunction may be
explained either by dissipation in a bow wave as the white dwarf's magnetic
field sweeps past the M dwarf or by a misaligned white dwarf's rotation axis
and oblique magnetic moment. In the latter case the rotation axis precesses
with a period of decades, predicting a drift in the orbital phase of maximum.
Binaries whose emission is powered by synchronization may be termed
synchronars, in analogy to magnetars.


title: MHD-kinetic transition in imbalanced Alfv\'enic turbulence

abstract:
  Alfv\'enic turbulence in space is usually imbalanced: amplitudes of waves
propagating parallel and anti-parallel to the mean magnetic field $B_0$ are
unequal. It is commonly accepted that the turbulence is driven by
(counter-)collisions between these counter-propagating wave fractions. Contrary
to this, we found a new ion-scale dynamical range of the turbulence established
by (co-)collisions among waves co-propagating in the same direction along
$B_0$. Co-collisions become stronger than counter-collisions and produce steep
non-universal spectra above certain wavenumbers dependent on the imbalance.
Spectral indexes of the strong turbulence vary around -3, such that steeper
spectra follow larger imbalances. Intermittency steepens the -3 spectra
further, up to -3.7. Our theoretical predictions are compatible with steep
variable spectra observed in the solar wind at ion kinetic scales, but further
verifications are needed by correlating observed spectra with measured
imbalances.


title: Qudit quantum computation on matrix product states with global symmetry

abstract:
  Resource states that contain nontrivial symmetry-protected topological order
are identified for universal single-qudit measurement-based quantum
computation. Our resource states fall into two classes: one as the qudit
generalizations of the 1D qubit cluster state, and the other as the
higher-symmetry generalizations of the spin-1 Affleck-Kennedy-Lieb-Tasaki
(AKLT) state, namely, with unitary, orthogonal, or symplectic symmetry. The
symmetry in cluster states protects information propagation (identity gate),
while the higher symmetry in AKLT-type states enables nontrivial gate
computation. This work demonstrates a close connection between
measurement-based quantum computation and symmetry-protected topological order.


title:
Recovering 0 Kelvin Effective Hamiltonian Parameters from
  High-Temperature Disordered Phases

abstract:
  Effective Hamiltonians, when used in tandem with statistical mechanics
techniques, offer a rigorous connection between 0 Kelvin ab-initio predictions
and finite temperature experimental observations. For alloys, cluster expansion
Hamiltonians can coarse-grain out the complex, many-body electron problem of
density functional theory, yielding a series of simple site-wise basis
functions (e.g., products of site occupancy variables) on an atomic scale. The
resulting energy polynomial is computationally inexpensive, and hence suitable
for the (tens of) thousands of calculations of large systems required by
stochastic methods. We present a new method to run the statical mechanics
problem "in reverse", using high-temperature observations and thermodynamic
connections to construct an effective Hamiltonian and thereby predict the 0
Kelvin energy spectrum and associated ground states. By re-examining the
cluster expansion formalism through the lens of entropy-maximization
approaches, we develop an algorithm to select clusters and determine cluster
interactions using only a few, high-temperature experiments on disordered
phases. We demonstrate that our approach can recover not only the stable ground
states at 0 Kelvin, but also the full phase behavior for three realistic
two-dimensional and three-dimensional alloy test-cases.


title:
Initial energy density of $\sqrt{s}=$ 7 and 8 TeV p+p collisions at the
  LHC

abstract:
  Results from the RHIC and LHC experiments show, that in relativistic heavy
ion collisions, a new state of matter, a strongly interacting perfect fluid is
created. Accelerating, exact and explicit solutions of relativistic
hydrodynamics allow for a simple and natural description of this medium. A
finite rapidity distribution arises from these solutions, leading to an
advanced estimate of the initial energy density of high energy collisions.
These solutions can be utilized to describe various aspects of proton-proton
collisions, as originally suggested by Landau. We show that an advanced
estimate based on hydrodynamics yields an initial energy density in
$\sqrt{s}=7$ and 8 TeV p+p collisions at LHC on the same order as the critical
energy density from lattice QCD, and a corresponding initial temperature around
the critical temperature from QCD and the Hagedorn temperature. The
multiplicity dependence of the estimated initial energy density suggests that
in high multiplicity pp collisions at the LHC, there is large enough initial
energy density to create a non-hadronic perfect fluid.


title:
Simulating the radiofrequency dielectric response of relaxor
  ferroelectrics: Combination of Coarse-Grained Hamiltonians and Kinetic Monte
  Carlo

abstract:
  The radiofrequency dielectric response of the lead-free
Ba(Zr$_{0.5}$Ti$_{0.5}$)O$_3$ relaxor ferroelectric is simulated using a
coarse-grained Hamiltonian. This concept, taken from Real-Space Renormalization
Group theories, allows depicting the collective behavior of correlated local
modes gathered in blocks. Free-energy barriers for their thermally activated
collective hopping are deduced from this {\it ab-initio}-based approach, and
used as input data of Kinetic Monte Carlo simulations. The resulting numerical
scheme allows to simulate the dielectric response for external field
frequencies ranging from the kHz up to a few tens of MHz for the first time,
and to, e.g., demonstrate that local (electric or elastic) random fields lead
to the dielectric relaxation in the radiofrequency range that has been observed
in relaxors.


title:
Smooth Factors of Projective Actions of Higher Rank Lattices and
  Rigidity

abstract:
  We study smooth factors of the standard actions of lattices in higher rank
semisimple Lie groups on flag manifolds. Under a mild condition on existence of
a single differentiable sink, we show that these factors are
$C^{\infty}$-conjugate to the standard actions on flag manifolds.


title:
Cooperation in the two-population snowdrift game with punishment
  enforced through different mechanisms

abstract:
  I study two mechanisms based on punishment to promote cooperation in the
two-population snowdrift game. The first mechanism follows the traditional
approach in the literature and is based on the inclusion of a third additional
strategy in the payoff matrix of the stage-game. The second mechanism consists
of letting cooperators to punish defectors with a given exogenous frequency.
While both mechanisms share the same result regarding the minimum required
level of punishment in order to eliminate defectors in both populations,
stability in the mechanism following the second approach is more robust in the
sense that extinction of defectors is a globally asymptotically stable state
for any interior initial conditions in the phase space. Results were obtained
analytically through non-linear differential equations and also using an
agent-based simulation. There was a good level of agreement between both
approaches with respect to the evolutionary pattern over time and the possible
steady-states.


title: Low Rank Independence Samplers in Bayesian Inverse Problems

abstract:
  In Bayesian inverse problems, the posterior distribution is used to quantify
uncertainty about the reconstructed solution. In practice, Markov chain Monte
Carlo algorithms often are used to draw samples from the posterior
distribution. However, implementations of such algorithms can be
computationally expensive. We present a computationally efficient scheme for
sampling high-dimensional Gaussian distributions in ill-posed Bayesian linear
inverse problems. Our approach uses Metropolis-Hastings independence sampling
with a proposal distribution based on a low-rank approximation of the
prior-preconditioned Hessian. We show the dependence of the acceptance rate on
the number of eigenvalues retained and discuss conditions under which the
acceptance rate is high. We demonstrate our proposed sampler by using it with
Metropolis-Hastings-within-Gibbs sampling in numerical experiments in image
deblurring, computerized tomography, and NMR relaxometry.


title:
Primeval very low-mass stars and brown dwarfs. I. Six new L subdwarfs,
  classification and atmospheric properties

abstract:
  We have conducted a search for L subdwarf candidates within the photometric
catalogues of the UKIRT Infrared Deep Sky Survey and Sloan Digital Sky Survey.
Six of our candidates are confirmed as L subdwarfs spectroscopically at optical
and/or near infrared wavelengths. We also present new optical spectra of three
previously known L subdwarfs (WISEA J001450.17-083823.4, 2MASS
J00412179+3547133, ULAS J124425.75+102439.3). We examined the spectral types
and metallicity subclasses classification of known L subdwarfs. We summarised
the spectroscopic properties of L subdwarfs with different spectral types and
subclasses. We classify these new L subdwarfs by comparing their spectra to
known L subdwarfs and L dwarf standards. We estimate temperatures and
metallicities of 22 late type M and L subdwarfs by comparing their spectra to
BT-Settl models. We find that L subdwarfs have temperatures between 1500 K and
2700 K, which are higher than similarly-typed L dwarfs by around 100-400 K
depending on different subclasses and subtypes. We constrained the metallicity
ranges of subclasses of M, L and T subdwarfs. We also discussed the spectral
type and absolute magnitude relationships for L and T subdwarfs.


title:
An Enumeration of the Supercharacter Theories of $C_p \times C_2 \times
  C_2$ for Prime $p$

abstract:
  The supercharacter theories of $C_p \times C_2 \times C_2$ were classified in
the language of Schur rings by Evdokimov, Kov\'acs, and Ponomarenko in [EKP16].
It was shown that every nontrivial supercharacter theory of $C_p \times C_2
\times C_2$ can be constructed as a wedge product, a direct product, or is
generated by automorphisms. We use this classification to give a precise count
of the distinct supercharacter theories of $C_p\times C_2\times C_2$ and
describe when a supercharacter theory can be constructed by more than one
method. We also present an alternative proof of the classification using the
language of supercharacter theories.


title:
An extended characterization of a class of optimal three-weight cyclic
  codes over any finite field

abstract:
  A characterization of a class of optimal three-weight cyclic codes of
dimension 3 over any finite field was recently presented in [10]. Shortly after
this, a generalization for the sufficient numerical conditions of such
characterization was given in [3]. The main purpose of this work is to show
that the numerical conditions found in [3], are also necessary. As we will see
later, an interesting feature of the present work, in clear contrast with these
two preceding works, is that we use some new and non-conventional methods in
order to achieve our goals. In fact, through these non-conventional methods, we
not only were able to extend the characterization in [10], but also present a
less complex proof of such extended characterization, which avoids the use of
some of the sophisticated --but at the same time complex-- theorems, that are
the key arguments of the proofs given in [10] and [3]. Furthermore, we also
find the parameters for the dual code of any cyclic code in our extended
characterization class. In fact, after the analysis of some examples, it seems
that such dual codes always have the same parameters as the best known linear
codes.


title: Holomorphic Flexibility Properties of Spaces of Elliptic Functions

abstract:
  Let $X$ be an elliptic curve and $\mathbb{P}$ the Riemann sphere. Since $X$
is compact, it is a deep theorem of Douady that the set
$\mathcal{O}(X,\mathbb{P})$ consisting of holomorphic maps $X\to \mathbb{P}$
admits a complex structure. If $R_n$ denotes the set of maps of degree $n$,
then Namba has shown for $n\geq2$ that $R_n$ is a $2n$-dimensional complex
manifold. We study holomorphic flexibility properties of the spaces $R_2$ and
$R_3$. Firstly, we show that $R_2$ is homogeneous and hence an Oka manifold.
Secondly, we present our main theorem, that there is a $6$-sheeted branched
covering space of $R_3$ that is an Oka manifold. It follows that $R_3$ is
$\mathbb{C}$-connected and dominable. We show that $R_3$ is Oka if and only if
$\mathbb{P}_2\backslash C$ is Oka, where $C$ is a cubic curve that is the image
of a certain embedding of $X$ into $\mathbb{P}_2$. We investigate the strong
dominability of $R_3$ and show that if $X$ is not biholomorphic to
$\mathbb{C}/\Gamma_0$, where $\Gamma_0$ is the hexagonal lattice, then $R_3$ is
strongly dominable. As a Lie group, $X$ acts freely on $R_3$ by precomposition
by translations. We show that $R_3$ is holomorphically convex and that the
quotient space $R_3/X$ is a Stein manifold. We construct an alternative
$6$-sheeted Oka branched covering space of $R_3$ and prove that it is
isomorphic to our first construction in a natural way. This alternative
construction gives us an easier way of interpreting the fibres of the branched
covering map.


title:
Vacuum Cherenkov radiation and photon decay rates from generic Lorentz
  Invariance Violation

abstract:
  Among the most studied approaches to introduce the breaking of Lorentz
symmetry, the generic approach is one of the most frequently used for
phenomenology, it converges on the modification of the free particle dispersion
relation. Using this approach in the photon sector, we have calculated the
squared probability amplitude for vacuum Cherenkov radiation and photon decay
by correcting the QED coupling at tree level and first order in LIV parameters.
For the lower order energy correction we calculate the emission and decay rate
for each process.


title: Gapped Fermions in Top-down Holographic Superconductors

abstract:
  We use holography to compute spectral functions of certain fermionic
operators in three different finite-density, zero-temperature states of ABJM
theory with a broken U(1) symmetry. In each of the three states, dual to
previously studied domain wall solutions of four-dimensional gauged
supergravity, we find that the fermionic operators have gapped spectra. In one
case the gap can be traced to the small charge of the fermions, while in the
other cases it is due to a particular interaction that mixes particles and
holes.


title: Cavitation of Water by Volume-Controlled Stretching

abstract:
  A liquid subjected to negative pressure is thermodynamically metastable.
Confined within a small volume, negative pressure can build up until cavities
form spontaneously. The critical negative pressure for cavitation in water has
been theoretically predicted to be in the range of -100 to -200 MPa at room
temperature, whereas values around -30 MPa have been obtained by many
experiments. The discrepancy has yet to be resolved. In this study we perform
molecular dynamics simulations to study cavitation of water under volume
controlled stretching. It is found that liquid water exhibits a nonlinear
elastic compressibility (or stretchability) under hydrostatic tension and
remains stable within the confined volume until spontaneous cavitation occurs
at a critical strain. Subsequently, as the volume-controlled stretching
continues, the cavity grows stably and the hydrostatic tension decreases
continuously until the box volume is large enough for another transition to
form a water droplet. A modified nucleation theory is proposed to predict the
critical condition for cavitation. In particular, a strong dependence of the
critical strain and stress for cavitation on the initial liquid volume is
predicted by the modified nucleation theory, which may offer a possible
explanation for the discrepancies in the values of the critical negative
pressure obtained from experiments.


title: The Virial Relation and Intrinsic Shape of Early-Type Galaxies

abstract:
  Early-type galaxies (ETGs) are supposed to follow the virial relation $M =
k_e \sigma_*^2 R_e / G$, with $M$ being the mass, $\sigma_*$ being the stellar
velocity dispersion, $R_e$ being the effective radius, $G$ being Newton's
constant, and $k_e$ being the virial factor, a geometry factor of order unity.
Applying this relation to (a) the ATLAS3D sample of Cappellari et al. (2013)
and (b) the sample of Saglia et al. (2016) gives ensemble-averaged factors
$\langle k_e\rangle =5.15\pm0.09$ and $\langle k_e\rangle =4.01\pm0.18$,
respectively, with the difference arising from different definitions of
effective velocity dispersions. The two datasets reveal a statistically
significant tilt of the empirical relation relative to the theoretical virial
relation such that $M\propto(\sigma_*^2R_e)^{0.92}$. This tilt disappears when
replacing $R_e$ with the semi-major axis of the projected half-light ellipse,
$a$. All best-fit scaling relations show zero intrinsic scatter, implying that
the mass plane of ETGs is fully determined by the virial relation. Whenever a
comparison is possible, my results are consistent with, and confirm, the
results by Cappellari et al. (2013). The difference between the relations using
either $a$ or $R_e$ arises from a known lack of highly elliptical high-mass
galaxies; this leads to a scaling $(1-\epsilon) \propto M^{0.12}$, with
$\epsilon$ being the ellipticity and $R_e = a\sqrt{1-\epsilon}$. Accordingly,
$a$, not $R_e$, is the correct proxy for the scale radius of ETGs. By geometry,
this implies that early-type galaxies are axisymmetric and oblate in general,
in agreement with published results from modeling based on kinematics and light
distributions.


title: Shape of magnetic domain walls formed by coupling to mobile charges

abstract:
  Magnetic domain walls, which are crucially important in both fundamental
physics and technical applications, often have a preference in their form due
to many different origins, such as the crystalline shape, lattice symmetry, and
magnetic anisotropy. We theoretically investigate yet another origin stemming
from the coupling to mobile charges in itinerant magnets. Performing a
large-scale numerical simulation in a minimal model for itinerant magnets,
i.e., the Kondo lattice model with classical localized spins, we show that the
shape of magnetic domain walls depends on the electronic band structure and
electron filling. While Neel and 120 antiferromagnetic states do not show a
strong preference in the shape of domain walls, noncoplanar spin states with
scalar chiral ordering have distinct directional preferences of the domain
walls depending on the electron filling. We find that the directional
preference is rationalized by the wave-number dependence of the effective
magnetic interactions induced by the mobile charges, which are set by the band
structure and electron filling. We also observe that, in the noncoplanar chiral
states, an electric current is induced along the domain walls owing to the spin
Berry phase mechanism, with very different spatial distributions depending on
whether the bulk state is metallic or insulating.


title:
Tracking the Trackers: Towards Understanding the Mobile Advertising and
  Tracking Ecosystem

abstract:
  Third-party services form an integral part of the mobile ecosystem: they
allow app developers to add features such as performance analytics and social
network integration, and to monetize their apps by enabling user tracking and
targeted ad delivery. At present users, researchers, and regulators all have at
best limited understanding of this third-party ecosystem. In this paper we seek
to shrink this gap. Using data from users of our ICSI Haystack app we gain a
rich view of the mobile ecosystem: we identify and characterize domains
associated with mobile advertising and user tracking, thereby taking an
important step towards greater transparency. We furthermore outline our steps
towards a public catalog and census of analytics services, their behavior,
their personal data collection processes, and their use across mobile apps.


title: Simulated floating zone method

abstract:
  This paper provides the simulated floating zone (SFZ) method that is an
efficient simulation technique to obtain thermal equilibrium states, especially
useful when domain formation prevents the system from reaching a
spatially-uniform stable state. In the SFZ method, the system is heated up
locally, and the heated region is steadily shifted, similar to the floating
zone method for growing a single crystal with less lattice defect and impurity
in experiments. We demonstrate that the SFZ method suppresses domain formation
and accelerates the optimization of the state, taking an example of a magnetic
vortex crystal state realized in itinerant magnets. We show that the efficiency
is maximized when the local heating temperature is tuned to be comparable to
the characteristic energy scale of the ordered state.


title:
Hydra: Leveraging Functional Slicing for Efficient Distributed SDN
  Controllers

abstract:
  The conventional approach to scaling Software Defined Networking (SDN)
controllers today is to partition switches based on network topology, with each
partition being controlled by a single physical controller, running all SDN
applications. However, topological partitioning is limited by the fact that (i)
performance of latency-sensitive (e.g., monitoring) SDN applications associated
with a given partition may be impacted by co-located compute-intensive (e.g.,
route computation) applications; (ii) simultaneously achieving low convergence
time and response times might be challenging; and (iii) communication between
instances of an application across partitions may increase latencies. To tackle
these issues, in this paper, we explore functional slicing, a complementary
approach to scaling, where multiple SDN applications belonging to the same
topological partition may be placed in physically distinct servers. We present
Hydra, a framework for distributed SDN controllers based on functional slicing.
Hydra chooses partitions based on convergence time as the primary metric, but
places application instances across partitions in a manner that keeps response
times low while considering communication between applications of a partition,
and instances of an application across partitions. Evaluations using the
Floodlight controller show the importance and effectiveness of Hydra in
simultaneously keeping convergence times on failures small, while sustaining
higher throughput per partition and ensuring responsiveness to
latency-sensitive applications.


title: Recent results from the ARIANNA neutrino experiment

abstract:
  The ARIANNA experiment is currently taking data in its pilot-phase on the
Ross ice-shelf. Fully autonomous stations measure radio signals in the
frequency range from 100 MHz to 1 GHz. The seven station HRA was completed in
December 2014, and augmented by two special purpose stations with unique
configurations. In its full extent ARIANNA is targeted at detecting
interactions of cosmogenic neutrinos (> 1016eV) in the ice-shelf.
Downward-pointing antennas installed at the surface will record the radio
emission created by neutrino-induced showers in the ice and exploit the fact
that the ice- water surface acts as a mirror for radio emission. ARIANNA
stations are independent, low-powered, easy to install and equipped with
real-time communication via satellite modems. We report on the current status
of the HRA, as well as air shower detections that have been made over the past
year. Furthermore, we will discuss the search for neutrino emission, future
plans and the energy-dependent sensitivity of the experiment.


title:
Calculations of Magnetic properties of metals through the
  magnetic-field-containing relativistic tight-binding approximation method

abstract:
  Magnetic properties of metals are investigated through electronic structure
calculations based on the recently-proposed magnetic-field-containing
relativistic tight-binding approximation (MFRTB) method [Phys. Rev. B
\textbf{91}, 075122 (2015)]. It is found that electronic energy bands for the
metal immersed in the uniform magnetic field have a cluster structure in which
multiple energy bands lie within a small energy width. Each cluster corresponds
to the energy level that is derived on the basis of the semiclassical
approximation. While the cluster is responsible for the de Haas-van Alphen
(dHvA) oscillations, constituent energy bands of the cluster cause additional
oscillation peaks of the magnetization. Also, the energy width of the cluster
leads to the reduction of the amplitude of the dHvA oscillations, which can be
observed as the pseudo Dingle temperature and/or the overestimation of the
curvature of the Fermi surface.


title:
Balancing Statistical and Computational Precision and Applications to
  Penalized Linear Regression with Group Sparsity

abstract:
  Due to technological advances, large and high-dimensional data have become
the rule rather than the exception. Methods that allow for feature selection
with such data are thus highly sought after, in particular, since standard
methods, such as cross-validated lasso and group-lasso, can be challenging both
computationally and mathematically. In this paper, we propose a novel approach
to feature selection and group feature selection in linear regression. It
consists of simple optimization steps and tests, which makes it computationally
more efficient than standard approaches and suitable even for very large data
sets. Moreover, it satisfies sharp guarantees for estimation and feature
selection in terms of oracle inequalities. We thus expect that our contribution
can help to leverage the increasing volume of data in Biology, Public Health,
Astronomy, Economics, and other fields.


title: Review of multi-fidelity models

abstract:
  Simulations are often computationally expensive and the need for multiple
realizations, as in uncertainty quantification or optimization, makes surrogate
models an attractive option. For expensive high-fidelity models (HFMs),
however, even performing the number of simulations needed for fitting a
surrogate may be too expensive. Inexpensive but less accurate low-fidelity
models (LFMs) are often also available. Multi-fidelity models (MFMs) combine
HFMs and LFMs in order to achieve accuracy at a reasonable cost. With the
increasing popularity of MFMs in mind, the aim of this paper is to summarize
the state-of-the-art of MFM trends. For this purpose, publications in this
field are classified based on application, surrogate selection if any, the
difference between fidelities, the method used to combine these fidelities, the
field of application and the year published.
  Available methods of combining fidelities are also reviewed, focusing our
attention especially on multi-fidelity surrogate models in which fidelities are
combined inside a surrogate model. Computation time savings are usually the
reason for using MFMs, hence it is important to properly report the achieved
savings. Unfortunately, we find that many papers do not present sufficient
information to determine these savings. Therefore, the paper also includes
guidelines for authors to present their MFM savings in a way that is useful to
future MFM users. Based on papers that provided enough information, we find
that time savings are highly problem dependent and that MFM methods we surveyed
provided time savings up to 90%.
  Keywords: Multi-fidelity, Variable-complexity, Variable-fidelity, Surrogate
models, Optimization, Uncertainty quantification, Review, Survey


title:
Annotating Derivations: A New Evaluation Strategy and Dataset for
  Algebra Word Problems

abstract:
  We propose a new evaluation for automatic solvers for algebra word problems,
which can identify mistakes that existing evaluations overlook. Our proposal is
to evaluate such solvers using derivations, which reflect how an equation
system was constructed from the word problem. To accomplish this, we develop an
algorithm for checking the equivalence between two derivations, and show how
derivation an- notations can be semi-automatically added to existing datasets.
To make our experiments more comprehensive, we include the derivation
annotation for DRAW-1K, a new dataset containing 1000 general algebra word
problems. In our experiments, we found that the annotated derivations enable a
more accurate evaluation of automatic solvers than previously used metrics. We
release derivation annotations for over 2300 algebra word problems for future
evaluations.


title: The 17 MeV Anomaly in Beryllium Decays and $U(1)$ Portal to Dark Matter

abstract:
  The experiment of Krasznahorkay \textit{et al} observed the transition of a
$\rm{^{8}Be}$ excited state to its ground state and accompanied by an emission
of $e^{+}e^{-}$ pair with 17 MeV invariant mass. This 6.8$\sigma$ anomaly can
be fitted by a new light gauge boson. We consider the new particle as a $U(1)$
gauge boson, $Z'$, which plays as a portal linking dark sector and visible
sector. In particular, we study the new $U(1)$ gauge symmetry as a hidden or
non-hidden group separately. The generic hidden $U(1)$ model, referred to as
dark $Z$ model, is excluded by imposing various experimental constraints. On
the other hand, a non-hidden $Z'$ is allowed due to additional interactions
between $Z'$ and Standard Model fermions. We also study the implication of the
dark matter direct search on such a scenario. We found the search for the
DM-nucleon scattering excludes the range of DM mass above 500 MeV. However, the
DM-electron scattering for MeV-scale DM is still allowed by current constraints
for non-hidden $U(1)$ models. It is possible to test the underlying $U(1)$
portal model by the future Si and Ge detectors with $5e^{-}$ threshold charges.


title:
Critical Multipliers in Variational Systems via Second-order Generalized
  Differentiation

abstract:
  In this paper we introduce the notions of critical and noncritical
multipliers for subdifferential variational systems extending to a general
framework the corresponding notions by Izmailov and Solodov developed for
classical Karush-Kuhn-Tucker (KKT) systems. It has been well recognized that
critical multipliers are largely responsible for slow convergence of major
primal-dual algorithms of optimization. The approach of this paper allows us to
cover KKT systems arising in various classes of smooth and nonsmooth problems
of constrained optimization including composite optimization, minimax problems,
etc. Concentrating on a polyhedral subdifferential case and employing recent
results of second-order subdifferential theory, we obtain complete
characterizations of critical and noncritical multipliers via the problem data.
It is shown that noncriticality is equivalent to a certain error bound for a
perturbed variational system and that critical multipliers can be ruled out by
full stability of local minimizers in problems of composite optimization. For
the latter class we establish the equivalence between noncriticality of
multipliers and robust isolated calmness of the associated solution map and
then derive explicit characterizations of these notions via appropriate
second-order sufficient conditions. It is finally proved that the
Lipschitz-like/Aubin property of solution maps yields their robust isolated
calmness.


title: Multilayer Spectral Graph Clustering via Convex Layer Aggregation

abstract:
  Multilayer graphs are commonly used for representing different relations
between entities and handling heterogeneous data processing tasks. New
challenges arise in multilayer graph clustering for assigning clusters to a
common multilayer node set and for combining information from each layer. This
paper presents a theoretical framework for multilayer spectral graph clustering
of the nodes via convex layer aggregation. Under a novel multilayer signal plus
noise model, we provide a phase transition analysis that establishes the
existence of a critical value on the noise level that permits reliable cluster
separation. The analysis also specifies analytical upper and lower bounds on
the critical value, where the bounds become exact when the clusters have
identical sizes. Numerical experiments on synthetic multilayer graphs are
conducted to validate the phase transition analysis and study the effect of
layer weights and noise levels on clustering reliability.


title:
A Multiple-Comparison-Systems Method for Distributed Stability Analysis
  of Large-Scale Nonlinear Systems

abstract:
  Lyapunov functions provide a tool to analyze the stability of nonlinear
systems without extensively solving the dynamics. Recent advances in
sum-of-squares methods have enabled the algorithmic computation of Lyapunov
functions for polynomial systems. However, for general large-scale nonlinear
networks it is yet very difficult, and often impossible, both computationally
and analytically, to find Lyapunov functions. In such cases, a system
decomposition coupled to a vector Lyapunov functions approach provides a
feasible alternative by analyzing the stability of the nonlinear network
through a reduced-order comparison system. However, finding such a comparison
system is not trivial and often, for a nonlinear network, there does not exist
a single comparison system. In this work, we propose a multiple comparison
systems approach for the algorithmic stability analysis of nonlinear systems.
Using sum-of-squares methods we design a scalable and distributed algorithm
which enables the computation of comparison systems using only communications
between the neighboring subsystems. We demonstrate the algorithm by applying it
to an arbitrarily generated network of interacting Van der Pol oscillators.


title: Neighborhood growth dynamics on the Hamming plane

abstract:
  We initiate the study of general neighborhood growth dynamics on two
dimensional Hamming graphs. The decision to add a point is made by counting the
currently occupied points on the horizontal and the vertical line through it,
and checking whether the pair of counts lies outside a fixed Young diagram. We
focus on two related extremal quantities. The first is the size of the smallest
set that eventually occupies the entire plane. The second is the minimum of an
energy-entropy functional that comes from the scaling of the probability of
eventual full occupation versus the density of the initial product measure
within a rectangle. We demonstrate the existence of this scaling and study
these quantities for large Young diagrams.


title:
Performance degradation of superlattice MOSFETs due to scattering in the
  contacts

abstract:
  Ideal, completely coherent quantum transport calculations had predicted that
superlattice MOSFETs may offer steep subthreshold swing performance below
60mV/dec to around 39mV/dec. However, the high carrier density in the
superlattice source suggest that scattering may significantly degrade the ideal
device performance. Such effects of electron scattering and decoherence in the
contacts of superlattice MOSFETs are examined through a multiscale quantum
transport model developed in NEMO5. This model couples NEGF-based quantum
ballistic transport in the channel to a quantum mechanical density of states
dominated reservoir, which is thermalized through strong scattering with local
quasi-Fermi levels determined by drift-diffusion transport. The simulations
show that scattering increases the electron transmission in the nominally
forbidden minigap therefore degrading the subthreshold swing (S.S.) and the
ON/OFF DC current ratio. This degradation varies with both the scattering rate
and the length of the scattering dominated regions. Different superlattice
MOSFET designs are explored to mitigate the effects of such deleterious
scattering. Specifically, shortening the spacer region between the superlattice
and the channel from 3.5 nm to 0 nm improves the simulated S.S. from 51mV/dec.
to 40mV/dec. I. INTRODUCTION


title:
Geometric quantities arising from bubbling analysis of mean field
  equations

abstract:
  Let $E = \Bbb C/\Lambda$ be a flat torus and $G$ be its Green function with
singularity at $0$. Consider the multiple Green function $G_n$ on $E^n$:
$$G_{n}(z_1,\cdots,z_n) := \sum_{i < j} G(z_{i} - z_{j}) - n \sum_{i = 1} ^{n}
G(z_{i}).$$ A critical point $a = (a_1, \cdots, a_n)$ of $G_n$ is called
trivial if $\{a_1, \cdots, a_n\} = \{-a_1, \cdots, -a_n\}$. For such a point
$a$, two geometric quantities $D(a)$ and $H(a)$ arising from bubbling analysis
of mean field equations are introduced. $D(a)$ is a global quantity measuring
asymptotic expansion and $H(a)$ is the Hessian of $G_n$ at $a$. By way of
geometry of Lam\'e curves developed in our previous paper (Cambridge J. Math 3,
2015), we derive precise formulas to relate these two quantities.


title: The VINCIA Antenna Shower for Hadron Colliders

abstract:
  We summarise the main features of VINCIA's antenna-based treatment of QCD
initial- and final-state showers, which includes iterated tree-level
matrix-element corrections and automated evaluations of perturbative shower
uncertainties. The latter are computed on the fly and are cast as a set of
alternative weights for each generated event. The resulting algorithm has been
made publicly available as a plug-in to the PYTHIA 8 event generator.


title: Functional Laws for Trimmed Levy Processes

abstract:
  Two different ways of trimming the sample path of a stochastic process in
D[0, 1]: global ("trim as you go") trimming and record time ("lookback")
trimming are analysed to find conditions for the corresponding operators to be
continuous with respect to the (strong) J1-topology. A key condition is that
there should be no ties among the largest ordered jumps of the limit process.
As an application of the theory, via the continuous mapping theorem we prove
limit theorems for trimmed Levy processes, using the functional convergence of
the underlying process to a stable process. The results are applied to a
reinsurance ruin time problem.


title: Matching preclusion for $n$-grid graphs

abstract:
  A matching preclusion set of a graph is an edge set whose deletion results in
a graph without perfect matching or almost perfect matching. The Cartesian
product of $n$ paths is called an $n$-grid graph. In this paper, we study the
matching preclusion problems for $n$-grid graphs and obtain the following
results. If an $n$-grid graph has an even order, then it has the matching
preclusion number $n$, and every optimal matching preclusion set is trivial. If
the $n$-grid graph has an odd order, then it has the matching preclusion number
$n+1$, and all the optimal matching preclusion sets are characterized.


title: Holographic Photon Production in Heavy Ion Collisions

abstract:
  The thermal-photon emission from strongly coupled gauge theories at finite
temperature is calculated using holographic models for QCD in the Veneziano
limit (V-QCD). The emission rates are then embedded in hydrodynamic simulations
combined with prompt photons from hard scattering and the thermal photons from
hadron gas to analyze the spectra and anisotropic flow of direct photons at
RHIC and LHC. The results from different sources responsible for the thermal
photons in QGP including the weakly coupled QGP (wQGP) from perturbative
calculations, strongly coupled $\mathcal{N}=4$ super Yang-Mills (SYM) plasma
(as a benchmark for reference), and Gubser's phenomenological holographic model
are then compared. It is found that the direct-photon spectra are enhanced in
the strongly coupled scenario compared with the ones in the wQGP, especially at
high momenta. Moreover, both the elliptic flow and triangular flow of direct
photons are amplified at high momenta for V-QCD and the SYM plasma. The results
are further compared with experimental observations.


title:
Determining Hilbert Modular Forms by Central Values of Rankin-Selberg
  Convolutions: The Level Aspect

abstract:
  In this paper, we prove that a primitive Hilbert cusp form $\mathbf{g}$ is
uniquely determined by the central values of the Rankin-Selberg $L$-functions
$L(\mathbf{f}\otimes\mathbf{g}, \frac{1}{2})$, where $\mathbf{f}$ runs through
all primitive Hilbert cusp forms of level $\mathfrak{q}$ for infinitely many
prime ideals $\mathfrak{q}$. This result is a generalization of a theorem of
Luo to the setting of totally real number fields.


title: Commutator-based linearization of $N = 1$ nonlinear supersymmetry

abstract:
  We consider the linearization of $N = 1$ nonlinear supersymmetry (NLSUSY)
based on a commutator algebra in Volkov-Akulov NLSUSY theory. We show
explicitly that $U(1)$ gauge and scalar supermultiplets in addition to a vector
supermultiplet with general auxiliary fields in linear SUSY theories are
obtained from a same set of bosonic and fermionic functionals (composites)
which are expressed as simple products of the powers of a Nambu-Goldstone
fermion and a fundamental determinant in the NLSUSY theory.