title:
On the Accuracy of Fixed Sampled and Fixed Width Confidence Intervals
  Based on the Vertically Weighted Averages

abstract:
  Vertically weighted averages perform a bilateral filtering of data, in order
to preserve fine details of the underlying signal, especially discontinuities
such as jumps (in dimension one) or edges (in dimension two). In homogeneous
regions of the domain the procedure smoothes the data by averaging nearby data
points to reduce the noise, whereas in inhomogenous regions the neighboring
points are only taken into account when their value is close to the current
one. This results in a denoised reconstruction or estimate of the true signal
without blurring finer details.
  This paper addresses the lack of results about the construction and
evaluation of confidence intervals based on the vertically weighted average,
which is required for a proper statistical evaluation of its estimation
accuracy. Based on recent results we discuss and investigate in greater detail
fixed sample as well as fixed width (conditional) confidence intervals
constructed from this estimator. The fixed width approach allows to specify
explicitly the estimator's accuracy and determines a random sample size to
ensure the required coverage probability. This also fixes to some extent the
inherent property of the vertically weighted average that its variability is
higher in low-density regions than in high-density regions. To estimate the
variances required to construct the procedures, we rely on resampling
techniques, especially the bootstrap and the jackknife.
  Extensive Monte Carlo simulations show that the proposed confidence intervals
are reliable in terms of their coverage probabilities for a wide range of
parameter settings.


title:
A Novel Hybrid Fast Switching Adaptive No Delay Tanlock Loop Frequency
  Synthesizer

abstract:
  This paper presents a new fast switching hybrid frequency synthesizer with
wide locking range. The hybrid synthesizer is based on the tanlock loop with no
delay block (NDTL) and is capable of integer as well as fractional frequency
division. The system maintains the in-lock state following the division process
using an efficient adaptation mechanism. The fast switching and acquisition as
well as the wide locking range and the robust jitter performance of the new
hybrid NDTL synthesizer outperforms conventional time-delay tanlock loop (TDTL)
synthesizer by orders of magnitude, making it attractive for synthesis even in
Doppler environment. The performance of the hybrid synthesizer was evaluated
under various conditions and the results demonstrate that it achieves the
desired frequency division.


title:
Dynamical formation of Black Hole Low-Mass X-Ray Binaries in the field -
  an alternative to common envelope

abstract:
  Very wide binaries (> 500 AU) are subject to numerous encounters with
flying-by stars in the Galactic field and can be perturbated into highly
eccentric orbits (e ~ 0.99). For such systems tidal interactions at close
pericenter passages can lead to orbit circularization and possibly mass
transfer, consequently producing X-Ray binaries without the need for common
envelope. We test this scenario for the case of Black Hole Low-Mass X-Ray
Binaries (BH LMXBs) by performing a population synthesis from primordial
binaries with numerical treatment of random stellar encounters. We test various
models for the threshold pericenter distance under which tidal forces cause
circularization. We estimate that fly-by interactions can produce a current
population of ~ 60$-$220 BH LMXBs in the Galactic field. The results are
sensitive to the assumption on tidal circularization efficiency and zero to
very small BH natal kicks of a few km/s are required. We show that the most
likely donors are low-mass stars (< 1 Msun; at the onset of mass transfer) as
observed in the population of known sources (~ 20). However, the low number of
systems formed along this route is in tension with most recent observational
estimate of the number of dormant BH LMXBs in the Galaxy 10$^4-$10$^8$
(Tetarenko et al. 2016). If indeed the numbers are so high, alternative
formation channels of BHs with low-mass donors need to be identified.


title: Holographic free energy and thermodynamic geometry

abstract:
  We analytically obtain the free energy and thermodynamic geometry of
holographic superconductors in $2+1$-dimensions. The gravitational theory in
the bulk dual to this $2+1$-dimensional strongly coupled theory lives in the
$3+1$-dimensions and is that of a charged $AdS$ black hole together with a
massive charged scalar field. The matching method is applied to obtain the
nature of the fields near the horizon using which the holographic free energy
is computed through the gauge/gravity duality. The critical temperature is
obtained for a set of values of the matching point of the near horizon and the
boundary behaviour of the fields. The thermodynamic geometry is then computed
from the free energy of the boundary theory. From the divergence of the
thermodynamic scalar curvature, the critical temperature is obtained once
again. We then compare this result for the critical temperature with that
obtained from the matching method.


title: Behaviour of the reference measure on $\sf RCD$ spaces under charts

abstract:
  Mondino and Naber recently proved that finite dimensional $\sf RCD$ spaces
are rectifiable. Here we show that the push-forward of the reference measure
under the charts built by them is absolutely continuous with respect to the
Lebesgue measure. This result, read in conjunction with another recent work of
us, has relevant implications on the structure of tangent spaces to $\sf RCD$
spaces. A key tool that we use is a recent paper by De Philippis-Rindler about
the structure of measures on the Euclidean space.


title: On the Sensitivity Conjecture for Disjunctive Normal Forms

abstract:
  The sensitivity conjecture of Nisan and Szegedy [CC '94] asks whether for any
Boolean function $f$, the maximum sensitivity $s(f)$, is polynomially related
to its block sensitivity $bs(f)$, and hence to other major complexity measures.
Despite major advances in the analysis of Boolean functions over the last
decade, the problem remains widely open.
  In this paper, we consider a restriction on the class of Boolean functions
through a model of computation (DNF), and refer to the functions adhering to
this restriction as admitting the Normalized Block property. We prove that for
any function $f$ admitting the Normalized Block property, $bs(f) \leq 4s(f)^2$.
We note that (almost) all the functions mentioned in literature that achieve a
quadratic separation between sensitivity and block sensitivity admit the
Normalized Block property.
  Recently, Gopalan et al. [ITCS '16] showed that every Boolean function $f$ is
uniquely specified by its values on a Hamming ball of radius at most $2s(f)$.
We extend this result and also construct examples of Boolean functions which
provide the matching lower bounds.


title: Integrability of the eta-deformed Neumann-Rosochatius model

abstract:
  An integrable deformation of the well-known Neumann-Rosochatius system is
studied by considering generalised bosonic spinning solutions on the
eta-deformed AdS_5 x S^5 background. For this integrable model we construct a
4x4 Lax representation and a set of integrals of motion that ensures its
Liouville integrability. These integrals of motion correspond to the deformed
analogues of the Neumann-Rosochatius integrals and generalise the previously
found integrals for the eta-deformed Neumann and (AdS_5 x S^5)_eta geodesic
systems. Finally, we briefly comment on consistent truncations of this model.


title:
Room-temperature formation of Pt$_3$Si/Pt$_2$Si films on poly-Si
  substrates

abstract:
  We propose a way of formation of thin bilayer Pt$_3$Si/Pt$_2$Si films at room
temperature on poly-Si substrates by Pt magnetron sputtering and wet etching,
obtain such film, investigate its structure and phase composition and estimate
the thickness of its layers. We verify by direct x-ray
photoelectron-spectroscopic measurements our previous observation of the
Pt$_2$Si layer formaton between Pt and poly-Si films as a result of Pt
magnetron sputtering at room temperature. This layer likely appears due to high
enough temperature of Pt ions in the magnetron plasma sufficient for chemical
reaction of the silicide film formation on the Si surface. The Pt$_3$Si layer
likely forms from the Pt--Pt$_3$Si layer (Pt$_{95}$Si$_5$), which arises under
Pt film during the magnetron sputtering, as a result of Pt removal by wet
etching.


title: An Analysis of the Replicator Dynamics for an Asymmetric Hawk-Dove Game

abstract:
  We analyze, using a dynamical systems approach, the replicator dynamics for
the asymmetric Hawk-Dove game in which there is a set of four pure strategies
with arbitrary payoffs. We give a full account of the equilibrium points and
their stability and derive the Nash equilibria. We also give a detailed account
of the local bifurcations that the system exhibits based on choices of the
typical Hawk-Dove parameters and . We also give details on the connections
between the results found in this work and those of the standard two-strategy
Hawk-Dove game. We conclude the paper with some examples of numerical
simulations that further illustrate some global behaviours of the system.


title: The Integral Form of Supergravity

abstract:
  By using integral forms we derive the superspace action of D=3, N=1
supergravity as an integral on a supermanifold. The construction is based on
target space picture changing operators, here playing the role of Poincare'
duals to the lower-dimensional spacetime surfaces embedded into the
supermanifold. We show how the group geometrical action based on the group
manifold approach interpolates between the superspace and the component
supergravity actions, thus providing another proof of their equivalence.


title: HeMIS: Hetero-Modal Image Segmentation

abstract:
  We introduce a deep learning image segmentation framework that is extremely
robust to missing imaging modalities. Instead of attempting to impute or
synthesize missing data, the proposed approach learns, for each modality, an
embedding of the input image into a single latent vector space for which
arithmetic operations (such as taking the mean) are well defined. Points in
that space, which are averaged over modalities available at inference time, can
then be further processed to yield the desired segmentation. As such, any
combinatorial subset of available modalities can be provided as input, without
having to learn a combinatorial number of imputation models. Evaluated on two
neurological MRI datasets (brain tumors and MS lesions), the approach yields
state-of-the-art segmentation results when provided with all modalities;
moreover, its performance degrades remarkably gracefully when modalities are
removed, significantly more so than alternative mean-filling or other synthesis
approaches.


title:
Response to defects in multi- and bipartite entanglement of isotropic
  quantum spin networks

abstract:
  Quantum networks are an integral component in performing efficient
computation and communication tasks that are not accessible using classical
systems. A key aspect in designing an effective and scalable quantum network is
generating entanglement between its nodes, which is robust against defects in
the network. We consider an isotropic quantum network of spin-1/2 particles
with a finite fraction of defects, where the corresponding wave function of the
network is rotationally invariant under the action of local unitaries, and we
show that any reduced density matrix also remains unaltered under the local
actions. By using quantum information-theoretic concepts like strong
subadditivity of von Neumann entropy and approximate quantum telecloning, we
prove analytically that in the presence of defects, caused by loss of a finite
fraction of spins, the network sustains genuine multisite entanglement, and at
the same time may exhibit finite moderate-range bipartite entanglement, in
contrast to the network with no defects.


title:
J-freezing and Hund's rules in spin-orbit-coupled multiorbital Hubbard
  models

abstract:
  We investigate the phase diagram of the spin-orbit-coupled three orbital
Hubbard model at arbitrary filling by means of dynamical mean-field theory
combined with continuous-time quantum Monte Carlo. We find that the
spin-freezing crossover occurring in the metallic phase of the non-relativistic
multiorbital Hubbard model can be generalized to a $\mathbf{J}$-freezing
crossover, with $\mathbf{J}=\mathbf{L}+\mathbf{S}$, in the spin-orbit-coupled
case. In the $\mathbf{J}$-frozen regime the correlated electrons exhibit a
non-trivial flavor selectivity and energy dependence. Furthermore, in the
regions near $n=2$ and $n=4$ the metallic states are qualitatively different
from each other, which reflects the atomic Hund's third rule. Finally, we
explore the appearance of magnetic order from exciton condensation at $n=4$ and
discuss the relevance of our results for real materials.


title: Prime Power and Prime Product Distance Graphs

abstract:
  A graph $G$ is a $k$-prime product distance graph if its vertices can be
labeled with distinct integers such that for any two adjacent vertices, the
difference of their labels is the product of at most $k$ primes. A graph has
prime product number $ppn(G)=k$ if it is a $k$-prime product graph but not a
$(k-1)$-prime product graph. Similarly, $G$ is a prime $k$th-power graph
(respectively, strict prime $k$th-power graph) if its vertices can be labeled
with distinct integers such that for any two adjacent vertices, the difference
of their labels is the $j$th power of a prime, for $j \leq k$ (respectively,
the $k$th power of a prime exactly).
  We prove that $ppn(K_n) = \lceil \log_2(n)\rceil - 1$, and for a nonempty
$k$-chromatic graph $G$, $ppn(G) = \lceil \log_2(k)\rceil - 1$ or $ppn(G) =
\lceil \log_2(k)\rceil$. We determine $ppn(G)$ for all complete bipartite,
3-partite, and 4-partite graphs. We prove that $K_n$ is a prime $k$th-power
graph if and only if $n < 7$, and we determine conditions on cycles and
outerplanar graphs $G$ for which $G$ is a strict prime $k$th-power graph.
  We find connections between prime product and prime power distance graphs and
the Twin Prime Conjecture, the Green-Tao Theorem, and Fermat's Last Theorem.


title: A Traveling Feature in Saturn's Rings

abstract:
  The co-orbital satellites of Saturn, Janus and Epimetheus, swap radial
positions every 4.0 years. Since \textit{Cassini} has been in orbit about
Saturn, this has occurred on 21 January in 2006, 2010, and 2014. We describe
the effects of this radial migration in the Lindblad resonance locations of
Janus within the rings. When the swap occurs such that Janus moves towards
Saturn and Epimetheus away, nonlinear interference between now-relocated
density waves launches a solitary wave that travels through the rings with a
velocity approximately twice that of the local spiral density wave group
velocity in the A ring and commensurate with the spiral density wave group
velocity in the B ring.


title:
Gravitational Wave Signals from 3D Neutrino Hydrodynamics Simulations of
  Core-Collapse Supernovae

abstract:
  We present gravitational wave (GW) signal predictions from four 3D
multi-group neutrino hydrodynamics simulations of core-collapse supernovae of
progenitors with 11.2 Msun, 20 Msun, and 27 Msun. GW emission in the
pre-explosion phase strongly depends on whether the post-shock flow is
dominated by the standing accretion shock instability (SASI) or convection and
differs considerably from 2D models. SASI activity produces a strong signal
component below 250 Hz through asymmetric mass motions in the gain layer and a
non-resonant coupling to the proto-neutron star (PNS). Both convection- and
SASI-dominated models show GW emission above 250 Hz, but with considerably
lower amplitudes than in 2D. This is due to a different excitation mechanism
for high-frequency l=2 motions in the PNS surface, which are predominantly
excited by PNS convection in 3D. Resonant excitation of high-frequency surface
g-modes in 3D by mass motions in the gain layer is suppressed compared to 2D
because of smaller downflow velocities and a lack of high-frequency variability
in the downflows. In the exploding 20 Msun model, shock revival results in
enhanced low-frequency emission due to a change of the preferred scale of the
convective eddies in the PNS convection zone. Estimates of the expected excess
power in two frequency bands suggests that second-generation detectors will
only be able to detect very nearby events, but that third-generation detectors
could distinguish SASI- and convection-dominated models at distances of ~10
kpc.


title:
Constant entropy hybrid stars: a first approximation of cooling
  evolution

abstract:
  We aim to study the possibility of a hadron-quark phase transition in the
interior of neutron stars, taking into account different schematic evolutionary
stages at finite temperature. We also discuss the strange quark matter
stability in the quark matter phase. Furthermore, we aim to analyze the
astrophysical properties of hot and cold hybrid stars, considering the
constraint on maximum mass given by the pulsars J1614-2230 and J0348+0432. We
have developed a computational code to construct semi-analytical hybrid
equations of state at fixed entropy per baryon and to obtain different families
of hybrid stars. An analytical approximation of the Field Correlator Method is
developed for the quark matter equation of state. For the hadronic equation of
state we use a table based on the relativistic mean field theory, without
hyperons. We solved the relativistic structure equations of hydrostatic
equilibrium and mass conservation for hybrid star configurations. For the
different equations of state obtained, we calculated the stability window for
the strange quark matter, lepton abundances, temperature profiles and contours
profiles for the maximum mass star depending on the parameters of the Field
Correlator Method. We also computed the mass-radius and gravitational
mass-baryonic mass relationships for different hybrid star families. We have
analyzed different stages of hot hybrid stars as a first approximation of the
cooling evolution of neutron stars with quark matter cores. We obtain cold
hybrid stars with maximum masses $\geq 2 M_\odot$ for different combinations of
the Field Correlator Method parameters. In addition, our study based on the
gravitational mass - baryonic mass plane shows a late phase transition between
hadronic and quark matter during the proto-hybrid star evolution, in contrast
with previous studies of proto-neutron stars.


title: Covariant Symanzik identities

abstract:
  Classical isomorphism theorems due to Dynkin, Eisenbaum, Le Jan, and Sznitman
establish equalities between the correlation functions or distributions of
occupation times of random paths or ensembles of paths and Markovian fields,
such as the discrete Gaussian free field. We extend these results to the case
of real, complex, or quaternionic vector bundles of arbitrary rank over graphs
endowed with a connection, by providing distributional identities between
functionals of the Gaussian free vector field and holonomies of random paths.
As an application, we give a formula for computing moments of a large class of
random, in general non-Gaussian, fields in terms of holonomies of random paths
with respect to an annealed random gauge field, in the spirit of Symanzik's
foundational work on the subject.


title: Windows open for highly tunable magnetostructural phase transitions

abstract:
  An attempt was made to tailor the magnetostructural transitions (MSTs) over a
wide temperature range under the principle of isostructural alloying. A series
of wide Curie-temperature windows (CTWs) with a maximal width of 377 K between
69 and 446 K were established in the Mn1-yCoyNiGe1-xSix system. Throughout the
CTWs, the magnetic-field-induced metamagnetic behavior and giant magnetocaloric
effects are obtained. The (Mn,Co)Ni(Ge,Si) system shows great potential as
multifunctional phase-transition materials that work in a wide range covering
liquid-nitrogen and above water-boiling temperatures. Moreover, general
understanding to isostructural alloying and CTWs constructed in
(Mn,Co)Ni(Ge,Si) as well as (Mn,Fe)Ni(Ge,Si) are provided.


title:
BFKL evolution and the growth with energy of exclusive J/Psi and Upsilon
  photo-production cross-sections

abstract:
  We investigate whether the Balitsky-Fadin-Kuraev-Lipatov (BFKL) low x
evolution equation is capable to describe the energy dependence of the
exclusive photo-production cross-section of vector mesons J/Psi and Upsilon on
protons. Such cross-sections have been measured by both HERA experiments H1 and
ZEUS in electron-proton collisions and by LHC experiments ALICE, CMS and LHCb
in ultra-peripheral proton-proton and ultra-peripheral proton-lead collisions.
Our approach provides a perturbative description of the rise with energy and
relies only on a fit of the initial transverse momentum profile of the proton
impact factor, which can be extracted from BFKL fits to inclusive HERA data. We
find that BFKL evolution is capable to provide a very good description of the
energy dependence of the current data set, while the available fits of the
proton impact factor require an adjustment in the overall normalization.


title:
Manipulating Fock states of a harmonic oscillator while preserving its
  linearity

abstract:
  We present a new scheme for controlling the quantum state of a harmonic
oscillator by coupling it to an anharmonic multilevel system (MLS) with first
to second excited state transition frequency on-resonance with the oscillator.
In this scheme that we call "ef-resonant", the spurious oscillator Kerr
non-linearity inherited from the MLS is very small, while its Fock states can
still be selectively addressed via an MLS transition at a frequency that
depends on the number of photons. We implement this concept in a circuit-QED
setup with a microwave 3D cavity (the oscillator, with frequency 6.4 GHz and
quality factor QO=2E-6) embedding a frequency tunable transmon qubit (the MLS).
We characterize the system spectroscopically and demonstrate selective
addressing of Fock states and a Kerr non-linearity below 350 Hz. At times much
longer than the transmon coherence times, a non-linear cavity response with
driving power is also observed and explained.


title:
Shocks, rarefaction waves, and current fluctuations for anharmonic
  chains

abstract:
  The nonequilibrium dynamics of anharmonic chains is studied by imposing an
initial domain-wall state, in which the two half lattices are prepared in
equilibrium with distinct parameters. We analyse the Riemann problem for the
corresponding Euler equations and, in specific cases, compare with molecular
dynamics. Additionally, the fluctuations of time-integrated currents are
investigated. In analogy with the KPZ equation, their typical fluctuations
should be of size $t^{1/3}$ and have a Tracy-Widom GUE distributed amplitude.
The proper extension to anharmonic chains is explained and tested through
molecular dynamics. Our results are calibrated against the stochastic LeRoux
lattice gas.


title:
Crank-Nicolson finite element approximations for a linear stochastic
  fourth order equation with additive space-time white noise

abstract:
  We consider a model initial- and Dirichlet boundary- value problem for a
fourth-order linear stochastic parabolic equation, in one space dimension,
forced by an additive space-time white noise. First, we approximate its
solution by the solution of an auxiliary fourth-order stochastic parabolic
problem with additive, finite dimensional, spectral-type stochastic load. Then,
fully-discrete approximations of the solution to the approximate problem are
constructed by using, for the discretization in space, a standard Galerkin
finite element method based on $H^2$-piecewise polynomials, and, for
time-stepping, the Crank-Nicolson method. Analyzing the convergence of the
proposed discretization approach, we derive strong error estimates which show
that the order of strong convergence of the Crank-Nicolson finite element
method is equal to that reported in [Kosioris and Zouraris MMAN 44 (2010)] for
the Backward Euler finite element method.


title:
Effects of Crystal Anisotropy on Optical Phonon Resonances in the
  Mid-Infrared Second Harmonic Response of SiC

abstract:
  We study the effects of crystal anisotropy on optical phonon resonances in
the second harmonic generation (SHG) from silicon carbide (SiC) in its
Reststrahl region. By comparing experiments and simulations for isotropic
3C-SiC and anisotropic 4H-SiC in two crystal cuts, we identify several
pronounced effects in the nonlinear response which arise solely from the
crystal anisotropy. Specifically, we demonstrate that the axial and planar
transverse optical phonon resonances selectively and exclusively appear in the
corresponding tensor elements of the nonlinear susceptibility, enabling
observation of an intense SHG peak originating from a weak phonon mode due to
zone-folding along the c-axis of 4H-SiC. Similarly, we identify an anisotropy
factor $\zeta \equiv \epsilon_\perp/\epsilon_\parallel$ responsible for a steep
enhancement of the transmitted fundamental fields at the axial longitudinal
optical phonon frequency, resulting in strongly enhanced SHG. We develop a
general recipe to extract all these features that is directly applicable to all
wurtzite-structure polar dielectrics, where a very similar behavior is
expected. Our model study illustrates the opportunities for utilizing the
crystal anisotropy for selectively enhancing nonlinear-optical effects in polar
dielectrics, which could potentially be extended to built-in anisotropy in
artificially designed hybrid materials.


title: Bag of Attributes for Video Event Retrieval

abstract:
  In this paper, we present the Bag-of-Attributes (BoA) model for video
representation aiming at video event retrieval. The BoA model is based on a
semantic feature space for representing videos, resulting in high-level video
feature vectors. For creating a semantic space, i.e., the attribute space, we
can train a classifier using a labeled image dataset, obtaining a
classification model that can be understood as a high-level codebook. This
model is used to map low-level frame vectors into high-level vectors (e.g.,
classifier probability scores). Then, we apply pooling operations to the frame
vectors to create the final bag of attributes for the video. In the BoA
representation, each dimension corresponds to one category (or attribute) of
the semantic space. Other interesting properties are: compactness, flexibility
regarding the classifier, and ability to encode multiple semantic concepts in a
single video representation. Our experiments considered the semantic space
created by state-of-the-art convolutional neural networks pre-trained on 1000
object categories of ImageNet. Such deep neural networks were used to classify
each video frame and then different coding strategies were used to encode the
probability distribution from the softmax layer into a frame vector. Next,
different pooling strategies were used to combine frame vectors in the BoA
representation for a video. Results using BoA were comparable or superior to
the baselines in the task of video event retrieval using the EVVE dataset, with
the advantage of providing a much more compact representation.


title:
Constrained Dynamic Control Allocation in the Presence of Singularity
  and Infeasible Solutions

abstract:
  Reliable controllers with high flexibility and performance are necessary for
the control of intricate, advanced, and expensive systems such as aircraft,
marine vessels, automotive vehicles, and satellites. Meanwhile, control
allocation has an important role in the control system design strategies of
such complex plants. Although there are many proposed control allocation
methodologies, few papers deal with the problems of infeasible solutions or
system matrix singularity. In this paper, a pseudo inverse based method is
employed and modified by the null space, least squares, and singular value
decomposition concepts to handle such situations. The proposed method could
successfully give an appropriate solution in both the feasible and infeasible
sections in the presence of singularity. The analytical approach guarantees the
solution with pre-defined computational burden which is a noticeable privilege
than the linear and quadratic optimization methods. Furthermore, the algorithm
complexity is proportionately grown with the feasible, infeasible, and
singularity conditions. Simulation results are used to show the effectiveness
of the proposed methodology.


title: Hierarchical Approximate Proper Orthogonal Decomposition

abstract:
  Proper Orthogonal Decomposition (POD) is a widely used technique for the
construction of low-dimensional approximation spaces from high-dimensional
input data. For large-scale applications and an increasing amount of input data
vectors, however, computing the POD often becomes prohibitively expensive. This
work presents a generic, easy-to-implement approach to compute an approximate
POD based on arbitrary tree hierarchies of worker nodes, where each worker
computes a POD of only a small amount of input vectors. The tree hierarchy can
be freely adapted to optimally suit the available computational resources. In
particular, this hierarchical approximate POD (HAPOD) allows for both simple
parallelization with low communication overhead, as well as live sequential POD
computation under restricted memory capacities. Rigorous error estimates ensure
the reliability of our approach, and extensive numerical examples underline its
performance.


title:
Spacetime Variation of Lorentz-Violation Coefficients at Nonrelativistic
  Scale

abstract:
  When the Standard-Model Extension (SME) is applied in curved spacetime, the
Lorentz-violation coefficients must depend on spacetime position. This work
describes some of the consequences of this spacetime variation. We focus on
effects that appear at a nonrelativistic scale and extract sensitivity of
completed experiments to derivatives of SME coefficient fields.


title:
Polynomial Lower Bound for Distributed Graph Coloring in a Weak LOCAL
  Model

abstract:
  We show an $\Omega\big(\Delta^{\frac{1}{3}-\frac{\eta}{3}}\big)$ lower bound
on the runtime of any deterministic distributed
$\mathcal{O}\big(\Delta^{1+\eta}\big)$-graph coloring algorithm in a weak
variant of the \LOCAL\ model.
  In particular, given a network graph \mbox{$G=(V,E)$}, in the weak \LOCAL\
model nodes communicate in synchronous rounds and they can use unbounded local
computation. We assume that the nodes have no identifiers, but that instead,
the computation starts with an initial valid vertex coloring. A node can
\textbf{broadcast} a \textbf{single} message of \textbf{unbounded} size to its
neighbors and receives the \textbf{set of messages} sent to it by its
neighbors. That is, if two neighbors of a node $v\in V$ send the same message
to $v$, $v$ will receive this message only a single time; without any further
knowledge, $v$ cannot know whether a received message was sent by only one or
more than one neighbor.
  Neighborhood graphs have been essential in the proof of lower bounds for
distributed coloring algorithms, e.g., \cite{linial92,Kuhn2006On}. Our proof
analyzes the recursive structure of the neighborhood graph of the respective
model to devise an $\Omega\big(\Delta^{\frac{1}{3}-\frac{\eta}{3}}\big)$ lower
bound on the runtime for any deterministic distributed
$\mathcal{O}\big(\Delta^{1+\eta}\big)$-graph coloring algorithm.
  Furthermore, we hope that the proof technique improves the understanding of
neighborhood graphs in general and that it will help towards finding a lower
(runtime) bound for distributed graph coloring in the standard \LOCAL\ model.
Our proof technique works for one-round algorithms in the standard \LOCAL\
model and provides a simpler and more intuitive proof for an existing
$\Omega(\Delta^2)$ lower bound.


title: mpEAd: Multi-Population EA Diagrams

abstract:
  Multi-population evolutionary algorithms are, by nature, highly complex and
difficult to describe. Even two populations working in concert (or opposition)
present a myriad of potential configurations that are often difficult to relate
using text alone. Little effort has been made, however, to depict these kinds
of systems, relying solely on the simple structural connections (related using
ad hoc diagrams) between populations and often leaving out crucial details. In
this paper, we propose a notation and accompanying formalism for consistently
and powerfully depicting these structures and the relationships within them in
an intuitive and consistent way. Using our notation, we examine simple
co-evolutionary systems and discover new configurations by the simple process
of "drawing on a whiteboard". Finally, we demonstrate that even complex,
highly-interconnected systems with large numbers of populations can be
understood with ease using the advanced features of our formalism


title: Lattice Prediction for Deeply Bound Doubly Heavy Tetraquarks

abstract:
  We investigate the possibility of $qq^\prime \bar b \bar b$ tetraquark bound
states using $n_f=2+1$ lattice QCD ensembles with pion masses $\simeq 164$,
$299$, and $415$ MeV. Motivated by observations from heavy baryon
phenomenology, we consider two lattice interpolating operators both of which
are expected to couple efficiently to tetraquark states: one with
diquark-antidiquark and one with a meson-meson structure. Using nonrelativistic
QCD to simulate the bottom quarks, we study the $ud\bar b \bar b$, $\ell s\bar
b \bar b$ channels with $\ell=u,d$, and find unambiguous signals for
strong-interaction-stable $J^P=1^+$ tetraquarks. These states are found to lie
$189(10)$ and $98(7)$ MeV below the corresponding free two-meson thresholds.


title: Algebraic Generating Functions for Gegenbauer Polynomials

abstract:
  It is shown that several of Brafman's generating functions for the Gegenbauer
polynomials are algebraic functions of their arguments, if the Gegenbauer
parameter differs from an integer by one-fourth or one-sixth. Two examples are
given, which come from recently derived expressions for associated Legendre
functions with octahedral or tetrahedral monodromy. It is also shown that if
the Gegenbauer parameter is restricted as stated, the Poisson kernel for the
Gegenbauer polynomials can be expressed in terms of complete elliptic
integrals. An example is given.


title:
Enhancement of critical temperature in fractal metamaterial
  superconductors

abstract:
  Fractal metamaterial superconductor geometry has been suggested and analyzed
based on the recently developed theoretical description of critical temperature
increase in epsilon near zero (ENZ) metamaterial superconductors. Considerable
enhancement of critical temperature has been predicted in such materials due to
appearance of large number of additional poles in the inverse dielectric
response function of the fractal. Our results agree with the recent observation
(Fratini et al. Nature 466, 841 (2010)) that fractal defect structure promotes
superconductivity.


title: Generative Simultaneous Localization and Mapping (G-SLAM)

abstract:
  Environment perception is a crucial ability for robot's interaction into an
environment. One of the first steps in this direction is the combined problem
of simultaneous localization and mapping (SLAM). A new method, called G-SLAM,
is proposed, where the map is considered as a set of scattered points in the
continuous space followed by a probability that states the existence of an
obstacle in the subsequent point in space. A probabilistic approach with
particle filters for the robot's pose estimation and an adaptive recursive
algorithm for the map's probability distribution estimation is presented. Key
feature of the G-SLAM method is the adaptive repositioning of the scattered
points and their convergence around obstacles. In this paper the goal is to
estimate the best robot trajectory along with the probability distribution of
the obstacles in space. For experimental purposes a four wheel rear drive car
kinematic model is used and results derived from real case scenarios are
discussed.


title:
Autonomous Quantum Refrigerator in a Circuit-QED Architecture Based on a
  Josephson Junction

abstract:
  An implementation of a small quantum absorption refrigerator in a circuit QED
architecture is proposed. The setup consists of three harmonic oscillators
coupled to a Josephson unction. The refrigerator is autonomous in the sense
that it does not require any external control for cooling, but only thermal
contact between the oscillators and heat baths at different temperatures. In
addition, the setup features a built-in switch, which allows the cooling to be
turned on and off. If timing control is available, this enables the possibility
for coherence-enhanced cooling. Finally, we show that significant cooling can
be achieved with experimentally realistic parameters and that our setup should
be within reach of current technology.


title:
Andreev and Majorana bound states in single and double quantum dot
  structures

abstract:
  We present a numerical study of the emergence of Majorana and Andreev bound
states in a system composed by two quantum dots, in which one of then is
coupled to a conventional superconductor, SC1, and the other connects to a
topological superconductor, SC2. By controlling the interdot coupling we can
drive the system from a two single (uncoupled) quantum dots to a double
(coupled) dot system configurations. We employ a recursive Green's function
technique that provides us with numerically exact results for the local density
of states of the system. We first show that in the uncoupled dot configuration
(single dot behavior) the Majorana and the Andreev bound states appear in an
individual dot in two completely distinct regimes. Therefore, they cannot
coexist in the single quantum dot system. We then study the coexistence of
these states in the coupled double-dot configuration. In this situation we show
that in the trivial phase of the SC2, the Andreev states are bound to an
individual quantum dot in the atomic regime (weak interdot coupling) or
extended over the entire molecule in the molecular regime (strong interdot
coupling). More interesting features is actually seen in the topological phase
of the SC2. In this case, in the atomic limit, the Andreev states appear bound
to one of the quantum dots while a Majorana zero mode appears in the other one.
In the molecular regime, on the other hand, the Andreev bound states take over
the entire molecule while the Majorana state remains always bound to one of the
quantum dots.


title: Manolescu correction terms and knots in the three-sphere

abstract:
  Manolescu correction terms are numerical invariants of homology three-spheres
arising from $\mathrm{Pin}(2)$-equivariant Seiberg-Witten theory that contain
information about homology cobordism. We discuss several constraints on these
invariants for homology spheres obtained by Dehn surgery on a knot in the
three-sphere (and, more generally, in an integral homology $L$-space) in terms
of the surgery coefficient, the concordance order, and the genus.


title: Monte Carlo simulations of an Ising bilayer with non-equivalent planes

abstract:
  We study the thermodynamic and magnetic properties of an Ising bilayer
ferrimagnet. The system is composed of two interacting non-equivalent planes in
which the intralayer couplings are ferromagnetic while the interlayer
interactions are antiferromagnetic. Moreover, one of the planes is randomly
diluted. The study is carried out within a Monte Carlo approach employing the
multiple histogram reweighting method and finite-size scaling tools. The
occurrence of a compensation phenomenon is verified and the compensation
temperature, as well as the critical temperature for the model, are obtained as
functions of the Hamiltonian parameters. We present a detailed discussion of
the regions of the parameter space where the compensation effect is present or
absent. Our results are then compared to a mean-field-like approximation
applied to the same model by Balcerzak and Sza{\l}owski (2014). Although the
Monte Carlo and mean-field results agree qualitatively, our quantitative
results are significantly different.


title:
Information-theoretic bounds and phase transitions in clustering, sparse
  PCA, and submatrix localization

abstract:
  We study the problem of detecting a structured, low-rank signal matrix
corrupted with additive Gaussian noise. This includes clustering in a Gaussian
mixture model, sparse PCA, and submatrix localization. Each of these problems
is conjectured to exhibit a sharp information-theoretic threshold, below which
the signal is too weak for any algorithm to detect. We derive upper and lower
bounds on these thresholds by applying the first and second moment methods to
the likelihood ratio between these "planted models" and null models where the
signal matrix is zero. Our bounds differ by at most a factor of root two when
the rank is large (in the clustering and submatrix localization problems, when
the number of clusters or blocks is large) or the signal matrix is very sparse.
Moreover, our upper bounds show that for each of these problems there is a
significant regime where reliable detection is information- theoretically
possible but where known algorithms such as PCA fail completely, since the
spectrum of the observed matrix is uninformative. This regime is analogous to
the conjectured 'hard but detectable' regime for community detection in sparse
graphs.

categories: math.ST cond-mat.dis-nn cond-mat.stat-mech cs.IT math.IT math.PR stat.TH


title: Needlet estimation of cross-correlation between CMB lensing maps and LSS

abstract:
  In this paper we develop a novel needlet-based estimator to investigate the
cross-correlation between cosmic microwave background (CMB) lensing maps and
large-scale structure (LSS) data. We compare this estimator with its harmonic
counterpart and, in particular, we analyze the bias effects of different forms
of masking. In order to address this bias, we also implement a MASTER-like
technique in the needlet case. The resulting estimator turns out to have an
extremely good signal-to-noise performance. Our analysis aims at expanding and
optimizing the operating domains in CMB-LSS cross-correlation studies,
similarly to CMB needlet data analysis. It is motivated especially by next
generation experiments (such as Euclid) which will allow us to derive much
tighter constraints on cosmological and astrophysical parameters through
cross-correlation measurements between CMB and LSS.


title: A note on dynamical models on random graphs and Fokker-Planck equations

abstract:
  We address the issue of the proximity of interacting diffusion models on
large graphs with a uniform degree property and a corresponding mean field
model, i.e. a model on the complete graph with a suitably renormalized
interaction parameter. Examples include Erd\H{o}s-R\'enyi graphs with edge
probability $p_n$, $n$ is the number of vertices, such that $\lim_{n \to
\infty}p_n n= \infty$. The purpose of this note it twofold: (1) to establish
this proximity on finite time horizon, by exploiting the fact that both systems
are accurately described by a Fokker-Planck PDE (or, equivalently, by a
nonlinear diffusion process) in the $n=\infty$ limit; (2) to remark that in
reality this result is unsatisfactory when it comes to applying it to systems
with $N$ large but finite, for example the values of $N$ that can be reached in
simulations or that correspond to the typical number of interacting units in a
biological system.


title:
The effect of mechanical strain on properties of lubricated tablets
  compacted at different pressures

abstract:
  A full factorial design of experiments was used to study the effect of blend
shear strain on the compaction process, relative density and strength of
pharmaceutical tablets. The powder blends were subjected to different shear
strain levels (integral of shear rate with respect to time) using an ad hoc
Couette shear cell. Tablets were compressed at different compaction forces
using an instrumented compactor simulator, and compaction curves showing the
force-displacement profiles during compaction were obtained. Although the
die-fill blend porosity (initial porosity) and the minimum in-die tablet
porosity (at maximum compaction) decreased significantly with shear strain, the
final tablet porosity was surprisingly independent of shear strain. The
increase in the in-die maximum compaction with shear strain was, in fact,
compensated during post-compaction relaxation of the tables, which also
increased significantly with shear strain. Therefore, tablet porosity alone was
not sufficient to predict tablet tensile strength. A decrease in the 'work of
compaction' as a function of shear strain, and an increase in the recovered
elastic work was observed, which suggested weaker particle-particle bonding as
the shear strain increased. For each shear strain level, the Ryskewitch
Duckworth equation was a good fit to the tensile strength as a function of
tablet porosity, and the obtained asymptotic tensile strength at zero porosity
exhibited a 60% reduction as a function of shear strain. This was consistent
with a reduced bonding efficiency as the shear strain increased.


title:
Lagrangian theory for cosmic structure formation with vorticity:
  Newtonian and post-Friedmann approximations

abstract:
  We study the nonlinear gravitational dynamics of a universe filled with a
pressureless fluid and a cosmological constant $\Lambda$ in the context of
Newtonian gravity, and in the relativistic post-Friedmann approach proposed in
paper I [I. Milillo et al., Phys. Rev. D 92, 023519 (2015).]. The
post-Friedmann approximation scheme is based on the $1/c$ expansion of the
space-time metric and the energy-momentum tensor, and includes nonlinear
Newtonian cosmology. Here we establish the nonlinear post-Friedmann framework
in the Lagrangian-coordinates approach for structure formation. For this we
first identify a Lagrangian gauge which is suitable for incorporating nonzero
vorticity. We analyze our results in two limits: at the leading order we
recover the fully nonlinear Newtonian cosmological equations in the Lagrangian
formulation, and we provide a space-time metric consistent from the perspective
of general relativity. We then linearize our expressions and recover the
relativistic results at first order in cosmological perturbation theory.
Therefore, the introduced approximation scheme provides a unified treatment for
the two leading-order regimes, from the small scales described by Newtonian
gravity to the large linear scale, where first-order relativistic cosmological
perturbation theory gives a very good description of structure formation.


title:
Stabilization of the chiral phase of the SU($6m$) Heisenberg model on
  the honeycomb lattice with $m$ particles per site for $m$ larger than 1

abstract:
  We show that, when $N$ is a multiple of 6 ($N=6m$, $m$ integer), the \SU{N}
Heisenberg model on the honeycomb lattice with $m$ particles per site has a
clear tendency toward chiral order as soon as $m\geq 2$. This conclusion has
been reached by a systematic variational Monte Carlo investigation of
Gutzwiller projected wave-functions as a function of $m$ between the case of
one particle per site ($m=1$), for which the ground state has recently been
shown to be in a plaquette singlet state, and the $m\rightarrow \infty$ limit,
where a mean-field approach has established that the ground state has chiral
order. This demonstrates that the chiral phase can indeed be stabilized for not
too large values of $m$, opening the way to its experimental realisations in
other lattices.


title: Ideal webs, moduli spaces of local systems, and 3d Calabi-Yau categories

abstract:
  A decorated surface S is an oriented surface with punctures and a finite set
of marked points on the boundary, such that each boundary component has a
marked point. We introduce ideal bipartite graphs on S. Each of them is related
to a group G of type A, and gives rise to cluster coordinate systems on certain
spaces of G-local systems on S. These coordinate systems generalize the ones
assigned to ideal triangulations of S. A bipartite graph on S gives rise to a
quiver with a canonical potential. The latter determines a triangulated 3d CY
category with a cluster collection of spherical objects. Given an ideal
bipartite graph on S, we define an extension of the mapping class group of S
which acts by symmetries of the category. There is a family of open CY 3-folds
over the universal Hitchin base, whose intermediate Jacobians describe the
Hitchin system. We conjecture that the 3d CY category with cluster collection
is equivalent to a full subcategory of the Fukaya category of a generic
threefold of the family, equipped with a cluster collection of special
Lagrangian spheres. For SL(2) a substantial part of the story is already known
thanks to Bridgeland, Keller, Labardini-Fragoso, Nagao, Smith, and others. We
hope that ideal bipartite graphs provide special examples of the
Gaiotto-Moore-Neitzke spectral networks.


title: Number Theoretic Transforms for Secure Signal Processing

abstract:
  Multimedia contents are inherently sensitive signals that must be protected
whenever they are outsourced to an untrusted environment. This problem becomes
a challenge when the untrusted environment must perform some processing on the
sensitive signals; a paradigmatic example is Cloud-based signal processing
services. Approaches based on Secure Signal Processing (SSP) address this
challenge by proposing novel mechanisms for signal processing in the encrypted
domain and interactive secure protocols to achieve the goal of protecting
signals without disclosing the sensitive information they convey.
  This work presents a novel and comprehensive set of approaches and primitives
to efficiently process signals in an encrypted form, by using Number Theoretic
Transforms (NTTs) in innovative ways. This usage of NTTs paired with
appropriate signal pre- and post-coding enables a whole range of easily
composable signal processing operations comprising, among others, filtering,
generalized convolutions, matrix-based processing or error correcting codes.
The main focus is on unattended processing, in which no interaction from the
client is needed; for implementation purposes, efficient lattice-based somewhat
homomorphic cryptosystems are used. We exemplify these approaches and evaluate
their performance and accuracy, proving that the proposed framework opens up a
wide variety of new applications for secured outsourced-processing of
multimedia contents.


title:
Interface Characteristics at an Organic/Metal Junction: Pentacene on Cu
  Stepped Surfaces

abstract:
  The adsorption of pentacene on Cu(221), Cu(511) and Cu(911) is investigated
using density functional theory (DFT) with the self-consistent inclusion of van
der Waals (vdW) interactions. Cu(211) is a vicinal of Cu(111) while Cu(511) and
(911) are vicinals of Cu(100). For all the three surfaces, we found pentacene
to prefer to adsorb parallel to the surface and near the steps. The addition of
vdW interactions resulted in an enhancement in adsorption energies, with
reference to the PBE functional, of around 2 eV. With vdWs inclusion, the
adsorption energies were found to be 2.98 eV, 3.20 eV and 3.49 eV for Cu(211),
Cu(511) and Cu(911) respectively. These values reflect that pentacene adsorbs
stronger on (100) terraces with a preference for larger terraces. The molecule
tilts upon adsorption with a small tilt angle on the (100) vicinals (about a
few degrees) as compared to a large one on Cu(221) where the tilt angle is
found to be about 20o. We find that the adsorption results in a net charge
transfer to the molecule of ~1 electron, for all surfaces.


title: A theory of nonequilibrium steady states in quantum chaotic systems

abstract:
  Nonequilibrium steady state (NESS) is a quasistationary state, in which exist
currents that continuously produce entropy, but the local observables are
stationary everywhere. We propose a theory of NESS under the framework of
quantum chaos. In an isolated quantum system, there exist some initial states
for which the thermodynamic limit and the long-time limit are noncommutative.
The density matrix $\hat \rho$ of these states displays a universal structure.
Suppose that $\alpha$ and $\beta$ are different eigenstates of the Hamiltonian
with energies $E_\alpha$ and $E_\beta$, respectively. $<\alpha|\hat
\rho|\beta>$ behaves as a random number which approximately follows the Laplace
distribution with zero mean. In thermodynamic limit, the variance of
$<\alpha|\hat \rho|\beta>$ is a smooth function of
$\left|E_\alpha-E_\beta\right|$, scaling as $1/(E_\alpha-E_\beta)^2$ in the
limit $\left|E_\alpha-E_\beta\right|\to 0$. If and only if this scaling law is
obeyed, the initial state evolves into NESS in the long time limit. We present
numerical evidence of our hypothesis in a few chaotic models. Furthermore, we
find that our hypothesis implies the eigenstate thermalization hypothesis (ETH)
in a bipartite system.


title: Multitracing Anisotropic Non-Gaussianity with Galaxy Shapes

abstract:
  Correlations between intrinsic galaxy shapes on large-scales arise due to the
effect of the tidal field of the large-scale structure. Anisotropic primordial
non-Gaussianity induces a distinct scale-dependent imprint in these tidal
alignments on large scales. Motivated by the observational finding that the
alignment strength of luminous red galaxies depends on how galaxy shapes are
measured, we study the use of two different shape estimators as a multi-tracer
probe of intrinsic alignments. We show, by means of a Fisher analysis, that
this technique promises a significant improvement on anisotropic
non-Gaussianity constraints over a single-tracer method. For future weak
lensing surveys, the uncertainty in the anisotropic non-Gaussianity parameter,
$A_2$, is forecast to be $\sigma(A_2)\approx 50$, $\sim 40\%$ smaller than
currently available constraints from the bispectrum of the Cosmic Microwave
Background. This corresponds to an improvement of a factor of $4-5$ over the
uncertainty from a single-tracer analysis.


title: Ambitwistors, oscillators and massless fields on $AdS_5$

abstract:
  Positive energy unitary irreducible representations of $SU(2,2)$ can be
constructed with the aid of bosonic oscillators in (anti)fundamental
representation of $SU(2)_L\times SU(2)_R$ that are closely related to Penrose
twistors. Starting with the correspondence between the doubleton
representations, homogeneous functions on projective twistor space and on-shell
$SL(2,\mathbb C)$ generalized Weyl curvature spinors and their low-spin
counterparts, we study in the similar way the correspondence between the
massless representations, homogeneous functions on ambitwistor space and, via
the Penrose transform, with the gauge fields on Minkowski boundary of $AdS_5$.
The possibilities of reconstructing massless fields on $AdS_5$ and some
applications are also discussed.


title: BaSn$_2$: A new, wide-gap, strong topological insulator

abstract:
  BaSn$_2$ has been shown to form as layers of buckled stanene intercalated by
barium ions~\cite{Kim_2008}. However, despite an apparently straightforward
synthesis and significant interest in stanene as a topological material,
BaSn$_2$ has been left largely unexplored, and has only recently been
recognized as a potential topological insulator. Belonging to neither the lead
nor bismuth chalcogenide families, it would represent a unique manifestation of
the topological insulating phase. Here we present a detailed investigation of
BaSn$_2$, using both {\it ab initio} and experimental methods. First-principles
calculations demonstrate that this overlooked material is a indeed strong
topological insulator with a bulk band gap of 360meV, among the largest
observed for topological insulators. We characterize the surface state
dependence on termination chemistry, providing guidance for experimental
efforts to measure and manipulate its topological properties. Additionally,
through {\it ab initio} modeling and synthesis experiments we explore the
stability and accessibility of this phase, revealing a complicated phase
diagram that indicates a challenging path to obtaining single crystals.


title: Extracting Geography from Trade Data

abstract:
  Understanding international trade is a fundamental problem in economics --
one standard approach is via what is commonly called the "gravity equation",
which predicts the total amount of trade $F_ij$ between two countries $i$ and
$j$ as $$ F_{ij} = G \frac{M_i M_j}{D_{ij}},$$ where $G$ is a constant, $M_i,
M_j$ denote the "economic mass" (often simply the gross domestic product) and
$D_{ij}$ the "distance" between countries $i$ and $j$, where "distance" is a
complex notion that includes geographical, historical, linguistic and
sociological components. We take the \textit{inverse} route and ask ourselves
to which extent it is possible to reconstruct meaningful information about
countries simply from knowing the bilateral trade volumes $F_{ij}$: indeed, we
show that a remarkable amount of geopolitical information can be extracted. The
main tool is a spectral decomposition of the Graph Laplacian as a tool to
perform nonlinear dimensionality reduction. This may have further applications
in economic analysis and provides a data-based approach to "trade distance".


title: Helicity Selection Rules and Non-Interference for BSM Amplitudes

abstract:
  Precision studies of scattering processes at colliders provide powerful
indirect constraints on new physics. We study the helicity structure of
scattering amplitudes in the SM and in the context of an effective Lagrangian
description of BSM dynamics. Our analysis reveals a novel set of helicity
selection rules according to which, in the majority of 2 to 2 scattering
processes at high energy, the SM and the leading BSM effects do not interfere.
In such situations, the naive expectation that dimension-6 operators represent
the leading BSM contribution is compromised, as corrections from dimension-8
operators can become equally (if not more) important well within the validity
of the effective field theory approach.


title: A Direct Proof of Schwichtenberg's Bar Recursion Closure Theorem

abstract:
  In 1979 Schwichtenberg showed that the System $\text{T}$ definable
functionals are closed under a rule-like version Spector's bar recursion of
lowest type levels $0$ and $1$. More precisely, if the functional $Y$ which
controls the stopping condition of Spector's bar recursor is
$\text{T}$-definable, then the corresponding bar recursion of type levels $0$
and $1$ is already $\text{T}$-definable. Schwichtenberg's original proof,
however, relies on a detour through Tait's infinitary terms and the
correspondence between ordinal recursion for $\alpha < \varepsilon_0$ and
primitive recursion over finite types. This detour makes it hard to calculate
on given concrete system $\text{T}$ input, what the corresponding system
$\text{T}$ output would look like. In this paper we present an alternative
(more direct) proof based on an explicit construction which we prove correct
via a suitably defined logical relation. We show through an example how this
gives a straightforward mechanism for converting bar recursive definitions into
$\text{T}$-definitions under the conditions of Schwichtenberg's theorem.
Finally, with the explicit construction we can also easily state a sharper
result: if $Y$ is in the fragment $\text{T}_i$ then terms built from
$\text{BR}^{\mathbb{N}, \sigma}$ for this particular $Y$ are definable in the
fragment $\text{T}_{i + \max \{ 1, \text{level}{\sigma} \} + 2}$.


title:
Suppression of Superfluid Density and the Pseudogap State in the
  Cuprates by Impurities

abstract:
  We use scanning tunneling microscopy (STM) to study magnetic Fe impurities
intentionally doped into the high-temperature superconductor
Bi$_{2}$Sr$_{2}$Ca$_{2}$CuO$_{8+\delta}$. Our spectroscopic measurements reveal
that Fe impurities introduce low-lying resonances in the density of states at
\Omega$_{1}$ $\approx$ 4meV and \Omega$_{2}$ $\approx$ 15 meV allowing us to
determine that, despite having a large magnetic moment, potential scattering of
quasiparticles by Fe impurities dominates magnetic scattering. In addition,
using high-resolution spatial characterizations of the local density of states
near and away from Fe impurities, we detail the spatial extent of impurity
affected regions as well as provide a local view of impurity-induced effects on
the superconducting and pseudogap states. Our studies of Fe impurities, when
combined with a reinterpretation of earlier STM work in the context of a
two-gap scenario, allow us to present a unified view of the atomic-scale
effects of elemental impurities on the pseudogap and superconducting states in
hole-doped cuprates; this may help resolve a previously assumed dichotomy
between the effects of magnetic and non-magnetic impurities in these materials.


title: Random space and plane curves

abstract:
  We study random knots, which we define as a triple of random periodic
functions (where a random function is a random trigonometric series,
\[f(\theta) = \sum_{k=1}^\infty a_k \cos (k \theta) +b_k (\sin k \theta),\]
with $a_k, b_k$ are independent gaussian random variables with mean $0$ and
variance $\sigma(k)^2$ - our results will depend on the functional dependence
of $\sigma$ on $k.$ In particular, we show that if $\sigma(k) = k^\alpha,$ with
$\alpha < -3/2,$ then the probability of getting a knot type which admits a
projection with $N$ crossings, decays at least as fast as $1/N.$ The constant
$3/2$ is significant, because having $\alpha < -3/2$ is exactly the condition
for $f(\theta)$ to be a $C^1$ function, so our class is precisely the class of
random \emph{tame} knots. We also find some suprising experimental observations
on the zeros of Alexander polynomials of random knots (with slowly and
non-decaying coefficients), and even more surprising observations on their
coefficients. Our observations persist in other models of random knots, making
it likely that the results are universal.


title:
Orbital Magnetic Field Driven Metal-Insulator Transition in Spinless
  Extended Falicov-Kimball Model on A Triangular Lattice

abstract:
  Ground state properties of spinless, extended Falicov-Kimball model (FKM) on
a finite size triangular lattice with orbital magnetic field normal to the
lattice are studied using numerical diagonalization and Monte-Carlo simulation
methods. We show that the ground state configurations of localized electrons
strongly depend on the magnetic field. Magnetic field induces a metal to
insulator transition accompanied by segregated phase to an ordered regular
phase except at density $n_f = 1/2$ of localized electrons. It is proposed that
magnetic field can be used as a new tool to produce segregated phase which was
otherwise accessible only either with correlated hopping or with large on-site
interactions.


title: Imitation Learning with Recurrent Neural Networks

abstract:
  We present a novel view that unifies two frameworks that aim to solve
sequential prediction problems: learning to search (L2S) and recurrent neural
networks (RNN). We point out equivalences between elements of the two
frameworks. By complementing what is missing from one framework comparing to
the other, we introduce a more advanced imitation learning framework that, on
one hand, augments L2S s notion of search space and, on the other hand,
enhances RNNs training procedure to be more robust to compounding errors
arising from training on highly correlated examples.


title:
A simple analytical description of the non-stationary dynamics in Ising
  spin systems

abstract:
  The analytical description of the dynamics in models with discrete variables
(e.g. Ising spins) is a notoriously difficult problem, that can be tackled only
under some approximation. Recently a novel variational approach to solve the
stationary dynamical regime has been introduced by Pelizzola [Eur. Phys. J. B,
86 (2013) 120], where simple closed equations are derived under mean-field
approximations based on the cluster variational method. Here we propose to use
the same approximation based on the cluster variational method also for the
non-stationary regime, which has not been considered up to now within this
framework. We check the validity of this approximation in describing the
non-stationary dynamical regime of several Ising models defined on
Erdos-R\'enyi random graphs: we study ferromagnetic models with symmetric and
partially asymmetric couplings, models with random fields and also spin glass
models. A comparison with the actual Glauber dynamics, solved numerically,
shows that one of the two studied approximations (the so-called 'diamond'
approximation) provides very accurate results in all the systems studied. Only
for the spin glass models we find some small discrepancies in the very low
temperature phase, probably due to the existence of a large number of
metastable states. Given the simplicity of the equations to be solved, we
believe the diamond approximation should be considered as the 'minimal
standard' in the description of the non-stationary regime of Ising-like models:
any new method pretending to provide a better approximate description to the
dynamics of Ising-like models should perform at least as good as the diamond
approximation.


title: Symbol $p$-Algebras of Prime Degree and their $p$-Central Subspaces

abstract:
  We prove that the maximal dimension of a $p$-central subspace of the generic
symbol $p$-algebra of prime degree $p$ is $p+1$. We do it by proving the
following number theoretic fact: let $\{s_1,\dots,s_{p+1}\}$ be $p+1$ distinct
nonzero elements in the additive group $G=(\mathbb{Z}/p \mathbb{Z}) \times
(\mathbb{Z}/p \mathbb{Z})$; then every nonzero element $g \in G$ can be
expressed as $d_1 s_1+\dots+d_{p+1} s_{p+1}$ for some non-negative integers
$d_1,\dots,d_{p+1}$ with $d_1+\dots+d_{p+1} \leq p-1$.


title: On Ring Learning with Errors over the Tensor Product of Number Fields

abstract:
  The "Ring Learning with Errors" (RLWE) problem was formulated as a variant of
the "Learning with Errors" (LWE) problem, with the purpose of taking advantage
of an additional algebraic structure in the underlying considered lattices;
this enables improvements on the efficiency and cipher expansion on those
cryptographic applications which were previously based on the LWE problem. In
Eurocrypt 2010, Lyubashevsky et al. introduced this hardness problem and showed
its relation to some known hardness problems over lattices with a special
structure. In this work, we generalize these results and the problems presented
by Lyubashevsky et al. to the more general case of multivariate rings,
highlighting the main differences with respect to the security proof for the
RLWE counterpart. This hardness problem is denoted as "Multivariate Ring
Learning with Errors" ($m$-RLWE or multivariate RLWE) and we show its relation
to hardness problems over the tensor product of ideal lattices. Additionally,
the $m$-RLWE problem is more adequate than its univariate version for
cryptographic applications dealing with multidimensional structures.


title:
Nonlinear dynamics from the relativistic Boltzmann equation in the
  Friedmann-Lema\^itre-Robertson-Walker spacetime

abstract:
  The dissipative dynamics of an expanding massless gas with constant cross
section in a spatially flat Friedmann-Lema\^itre-Robertson-Walker (FLRW)
universe is studied. The mathematical problem of solving the full nonlinear
relativistic Boltzmann equation is recast into an infinite set of nonlinear
ordinary differential equations for the moments of the one-particle
distribution function. Momentum-space resolution is determined by the number of
non-hydrodynamic modes included in the moment hierarchy, i.e., by the
truncation order. We show that in the FLRW spacetime the non-hydrodynamic modes
decouple completely from the hydrodynamic degrees of freedom. This results in
the system flowing as an ideal fluid while at the same time producing entropy.
The solutions to the nonlinear Boltzmann equation exhibit transient tails of
the distribution function with nontrivial momentum dependence. The evolution of
this tail is not correctly captured by the relaxation time approximation nor by
the linearized Boltzmann equation. However, the latter probes additional
high-momentum details unresolved by the relaxation time approximation. While
the expansion of the FLRW spacetime is slow enough for the system to move
towards (and not away from) local thermal equilibrium, it is not sufficiently
slow for the system to actually ever reach complete local equilibrium.
Equilibration is fastest in the relaxation time approximation, followed, in
turn, by kinetic evolution with a linearized and a fully nonlinear Boltzmann
collision term.

categories: hep-ph cond-mat.stat-mech gr-qc hep-th nucl-th


title: Note on the best approximation in $L^1$ metric

abstract:
  We present one of the approaches to find the best approximation of the given
function by trigonometric polynomials in $L^1$ metric and applied it to find
the optimal constants in the Nikolsky's type inequality, concerning
approximation of Lipschitz functions by algebraic polynomials.


title:
Hypercontractivity, supercontractivity, ultraboundedness and stability
  in semilinear problems

abstract:
  We study the Cauchy problem associated to a family of nonautonomous
semilinear equations in the space of bounded and continuous functions over R^d
and in L^p-spaces with respect to tight evolution systems of measures. Here,
the linear part of the equation is a nonautonomous second-order elliptic
operator with unbounded coefficients defined in IxR^d, (I being a
right-halfline). To the above Cauchy problem we associate a nonlinear evolution
operator, which we study in detail, proving some summability improving
properties. We also study the stability of the null solution to the Cauchy
problem.


title: Two Small Planets Transiting HD 3167

abstract:
  We report the discovery of two super-Earth-sized planets transiting the
bright (V = 8.94, K = 7.07) nearby late G-dwarf HD 3167, using data collected
by the K2 mission. The inner planet, HD 3167 b, has a radius of 1.6 R_e and an
ultra-short orbital period of only 0.96 days. The outer planet, HD 3167 c, has
a radius of 2.9 R_e and orbits its host star every 29.85 days. At a distance of
just 45.8 +/- 2.2 pc, HD 3167 is one of the closest and brightest stars hosting
multiple transiting planets, making HD 3167 b and c well suited for follow-up
observations. The star is chromospherically inactive with low rotational
line-broadening, ideal for radial velocity observations to measure the planets'
masses. The outer planet is large enough that it likely has a thick gaseous
envelope which could be studied via transmission spectroscopy. Planets
transiting bright, nearby stars like HD 3167 are valuable objects to study
leading up to the launch of the James Webb Space Telescope.


title:
Performance of a Nonempirical Density Functional on Molecules and
  Hydrogen-Bonded Complexes

abstract:
  Recently, Tao and Mo (TM) derived a meta-generalized gradient approximation
functional based on a model exchange-correlation hole. In this work, the
performance of this functional is assessed on standard test sets, using the
6-311++G(3df,3pd) basis set. These test sets include 223 G3/99 enthalpies of
formation, 99 atomization energies, 76 barrier heights, 58 electron affinities,
8 proton affinities, 96 bond lengths, 82 harmonic vibrational frequencies, 10
hydrogen-bonded molecular complexes, and 22 atomic excitation energies. Our
calculations show that the TM functional can achieve high accuracy for most
properties considered, relative to the LSDA, PBE, and TPSS functionals. In
particular, it yields the best accuracy for proton affinities, harmonic
vibrational frequencies, hydrogen-bonded dissociation energies and bond
lengths, and atomic excitation energies.


title: A low upper limit on the subsurface rise speed of solar active regions

abstract:
  Magnetic field emerges at the surface of the Sun as sunspots and active
regions. This process generates a poloidal magnetic field from a rising
toroidal flux tube, it is a crucial but poorly understood aspect of the solar
dynamo. The emergence of magnetic field is also important because it is a key
driver of solar activity. We show that measurements of horizontal flows at the
solar surface around emerging active regions, in combination with numerical
simulations of solar magnetoconvection, can constrain the subsurface rise speed
of emerging magnetic flux. The observed flows imply that the rise speed of the
magnetic field is no larger than 150 m/s at a depth of 20 Mm, that is, well
below the prediction of the (standard) thin flux tube model but in the range
expected for convective velocities at this depth. We conclude that convective
flows control the dynamics of rising flux tubes in the upper layers of the Sun
and cannot be neglected in models of flux emergence.


title:
The Emergence of Gravitational Wave Science: 100 Years of Development of
  Mathematical Theory, Detectors, Numerical Algorithms, and Data Analysis Tools

abstract:
  On September 14, 2015, the newly upgraded Laser Interferometer
Gravitational-wave Observatory (LIGO) recorded a loud gravitational-wave (GW)
signal, emitted a billion light-years away by a coalescing binary of two
stellar-mass black holes. The detection was announced in February 2016, in time
for the hundredth anniversary of Einstein's prediction of GWs within the theory
of general relativity (GR). The signal represents the first direct detection of
GWs, the first observation of a black-hole binary, and the first test of GR in
its strong-field, high-velocity, nonlinear regime. In the remainder of its
first observing run, LIGO observed two more signals from black-hole binaries,
one moderately loud, another at the boundary of statistical significance. The
detections mark the end of a decades-long quest, and the beginning of GW
astronomy: finally, we are able to probe the unseen, electromagnetically dark
Universe by listening to it. In this article, we present a short historical
overview of GW science: this young discipline combines GR, arguably the
crowning achievement of classical physics, with record-setting, ultra-low-noise
laser interferometry, and with some of the most powerful developments in the
theory of differential geometry, partial differential equations,
high-performance computation, numerical analysis, signal processing,
statistical inference, and data science. Our emphasis is on the synergy between
these disciplines, and how mathematics, broadly understood, has historically
played, and continues to play, a crucial role in the development of GW science.
We focus on black holes, which are very pure mathematical solutions of
Einstein's gravitational-field equations that are nevertheless realized in
Nature, and that provided the first observed signals.

categories: gr-qc physics.comp-ph physics.data-an physics.hist-ph physics.ins-det


title:
Assessment of a nonempirical semilocal density functional on solids and
  surfaces

abstract:
  Recently, Tao and Mo developed a new nonempirical semilocal
exchange-correlation density functional. The exchange part of this functional
is derived from a density matrix expansion corrected to reproduce the
fourth-order gradient expansion in the slowly varying limit, while the
correlation part is based on the TPSS correlation model with a modification for
the low-density limit. In the present work, the Tao-Mo functional is assessed
by calculations on a variety of solids and jellium surfaces. This includes 22
lattice constants and bulk moduli, 7 cohesive energies, and jellium surface
exchange and correlation energies for the density parameter rs in the range
from 2 to 3 bohrs. Our calculations show that this meta-generalized gradient
approximation can yield consistently remarkable accuracy for the properties
considered here, with mean absolute errors of 0.017 {\AA} for lattice
constants, 7.0 GPa for bulk moduli, 0.08 eV for cohesive energies, and 35
erg/cm2 for surface exchange-correlation energies, substantially improving upon
existing nonempirical semilocal density functionals.


title:
Ag diffusion in SiC high-energy grain boundaries: kinetic Monte Carlo
  study with first-principle calculations

abstract:
  The diffusion of silver (Ag) impurities in high energy grain boundaries
(HEGBs) of cubic (3C) silicon carbide (SiC) is studied using an ab initio based
kinetic Monte Carlo (kMC) model. This study assesses the hypothesis that the
HEGB diffusion is responsible for Ag release in Tristructural-Isotropic fuel
particles, and provides a specific example to increase understanding of
impurity diffusion in highly disordered grain boundaries. The HEGB environment
was modeled by an amorphous SiC. The structure and stability of Ag defects were
calculated using density functional theory code. The defect energetics
suggested that the fastest diffusion takes place via an interstitial mechanism
in a-SiC. The formation energy of Ag interstitials and the kinetic resolved
activation energies between them were well approximated with Gaussian
distributions that were then sampled in the kMC. The diffusion of Ag was
simulated with the effective medium model using kMC. At 1200-1600C, Ag in a
HEGB is predicted to exhibit an Arrhenius type diffusion and with a diffusion
prefactor and effective activation energy of (2.73+-1.09)*10-10 m2s-1 and
2.79+-0.18 eV, respectively. The comparison between HEGB results to other
theoretical studies suggested not only that GB diffusion is predominant over
bulk diffusion, but also that the HEGB is one of fastest grain boundary paths
for Ag diffusion in SiC. The Ag diffusion coefficient in the HEGB shows a good
agreement with ion-implantation measurements, but is 2-3 orders of magnitude
lower than the diffusion coefficients extracted from integral release
measurements. The discrepancy between GB diffusion and integral release
measurements suggests that other contributions are responsible for the fast
release of Ag in some experiments and we propose that these contributions may
arise from radiation enhanced diffusion.


title:
Measuring the Edwards-Anderson order parameter of the Bose glass: a
  quantum gas microscope approach

abstract:
  With the advent of spatially resolved fluorescence imaging in quantum gas
microscopes, it is now possible to directly image glassy phases and probe the
local effects of disorder in a highly controllable setup. Here we present
numerical calculations using a spatially-resolved local mean-field theory, show
that it captures the essential physics of the disordered system and use it to
simulate the density distributions seen in single-shot fluorescence microscopy.
From these simulated images we extract local properties of the phases which are
measurable by a quantum gas microscope and show that unambiguous detection of
the Bose glass is possible. In particular, we show that experimental
determination of the Edwards-Anderson order parameter is possible in a strongly
correlated quantum system using existing experiments. We also suggest
modifications to the experiments which will allow further properties of the
Bose glass to be measured.


title: Surveying the Inner Solar System with an Infrared Space Telescope

abstract:
  We present an analysis of surveying the inner Solar System for objects that
may pose some threat to the Earth. Most of the analysis is based on
understanding the capability provided by Sentinel, a concept for an infrared
space-based telescope placed in a heliocentric orbit near the distance of
Venus. From this analysis, we show 1) the size range being targeted can affect
the survey design, 2) the orbit distribution of the target sample can affect
the survey design, 3) minimum observational arc length during the survey is an
important metric of survey performance, and 4) surveys must consider objects as
small as D=15-30 m to meet the goal of identifying objects that have the
potential to cause damage on Earth in the next 100 years. Sentinel will be able
to find 50% of all impactors larger than 40 meters in a 6.5 year survey. The
Sentinel mission concept is shown to be as effective as any survey in finding
objects bigger than D=140 m but is more effective when applied to finding
smaller objects on Earth-impacting orbits. Sentinel is also more effective at
finding objects of interest for human exploration that benefit from lower
propulsion requirements. To explore the interaction between space and ground
search programs, we also study a case where Sentinel is combined with the Large
Synoptic Survey Telescope and show the benefit of placing a space-based
observatory in an orbit that reduces the overlap in search regions with a
ground-based telescope. In this case, Sentinel+LSST can find more than 70% of
the impactors larger than 40 meters assuming a 6.5 year lifetime for Sentinel
and 10 years for LSST.


title:
The Complexity of Quantum States and Transformations: From Quantum Money
  to Black Holes

abstract:
  These are lecture notes from a weeklong course in quantum complexity theory
taught at the Bellairs Research Institute in Barbados, February 21-25, 2016.
The focus is quantum circuit complexity---i.e., the minimum number of gates
needed to prepare a given quantum state or apply a given unitary
transformation---as a unifying theme tying together several topics of recent
interest in the field. Those topics include the power of quantum proofs and
advice states; how to construct quantum money schemes secure against
counterfeiting; and the role of complexity in the black-hole information
paradox and the AdS/CFT correspondence (through connections made by
Harlow-Hayden, Susskind, and others). The course was taught to a mixed audience
of theoretical computer scientists and quantum gravity / string theorists, and
starts out with a crash course on quantum information and computation in
general.


title:
Lepton flavor violating Z decays: A promising window to low scale seesaw
  neutrinos

abstract:
  In this paper we study the Lepton Flavor Violating $Z$ boson decays $Z \to
\tau \mu$ and $Z \to \tau e$ in the context of low scale seesaw models with new
heavy Majorana neutrinos whose masses could be reachable at the LHC. Our
computations of the decay rates are done in the particular realization given by
the Inverse Seesaw Model with six extra heavy neutrinos which are
quasi-degenerate in three pseudo-Dirac pairs. In particular, we focus on
scenarios that are built ad-hoc to produce suppressed rates in all the
processes involving $\mu$-$e$ transitions, given the fact that these are by far
the most strongly constrained by present data. We will fully explore the $Z \to
\tau \mu$ and $Z \to \tau e$ rates, together with a set of observables that we
find to be the most constraining ones, and we will conclude that sizable rates
of up to $2 \times 10^{-7}$, accessible at future colliders, can be reached in
this model for Majorana masses in the few TeV range, potentially reachable at
LHC.


title: Deep learning trends for focal brain pathology segmentation in MRI

abstract:
  Segmentation of focal (localized) brain pathologies such as brain tumors and
brain lesions caused by multiple sclerosis and ischemic strokes are necessary
for medical diagnosis, surgical planning and disease development as well as
other applications such as tractography. Over the years, attempts have been
made to automate this process for both clinical and research reasons. In this
regard, machine learning methods have long been a focus of attention. Over the
past two years, the medical imaging field has seen a rise in the use of a
particular branch of machine learning commonly known as deep learning. In the
non-medical computer vision world, deep learning based methods have obtained
state-of-the-art results on many datasets. Recent studies in computer aided
diagnostics have shown deep learning methods (and especially convolutional
neural networks - CNN) to yield promising results. In this chapter, we provide
a survey of CNN methods applied to medical imaging with a focus on brain
pathology segmentation. In particular, we discuss their characteristic
peculiarities and their specific configuration and adjustments that are best
suited to segment medical images. We also underline the intrinsic differences
deep learning methods have with other machine learning methods.


title:
Mode analysis of higher-order transverse-mode correlation beams in
  turbulent atmosphere

abstract:
  Due to the transfer of the angular spectrum of the pump beam to the
two-photon state in spontaneous parametric down-conversion the generated twin
photons are entangled in Hermite-Gaussian (HG) modes. This enables one using HG
modes as an alphabet for quantum communication. For global quantum
communication purposes, we derive an analytic expression for two-photon
detection probability in terms of HG modes taking into account the effects of
the turbulent atmosphere. Our result is more general as it accounts for the
propagation of both, signal and idler photons through the atmosphere, as
opposed to other works considering one of the photons' propagation in vacuum.
We show that while the restrictions on both the parity and order of the
down-converted HG fields no longer hold due to the crosstalk between modes when
propagating in the atmosphere, the crosstalk is not uniform: there are more
robust modes that tend to keep the photons in them. These modes can be employed
in order to increase the fidelity of quantum communication.


title: Solitons in generalized galileon theories

abstract:
  We consider the existence and stability of solitons in generalized galileons,
scalar field theories with higher-derivative interactions but second-order
equations of motion. It has previously been proven that no stable, static
solitons exist in a single galileon theory using an argument invoking the
existence of zero modes for the perturbations. Here we analyze the
applicability of this argument to generalized galileons and discuss how this
may be avoided by having potential terms in the energy functional for the
perturbations, or by including time dependence. Given the presence of potential
terms in the Lagrangian for the perturbations, we find that stable, static
solitons are not ruled out in conformal and (A)dS galileons. For the case of
DBI and conformal galileons, we find that solitonic solutions moving at the
speed of light exist, the former being stable and the latter unstable if the
background soliton satisfies a certain condition.


title: Gauge field spectrum in massive Yang-Mills theory with Lorentz violation

abstract:
  The spectrum of the massive CPT-odd Yang-Mills propagator with Lorentz
violation is performed at tree-level. The modification is due to mass terms
generated by the exigence of multiplicative renormalizability of Yang-Mills
theory with Lorentz violation. The causality analysis is performed from group
and front velocities for both, spacelike and timelike background tensors. It is
show that, by demanding causality, it is always possible to define a physical
sector for the gauge propagator. Hence, it is expected that the model is also
unitary, if one takes the Faddeev-Popov ghost into account.


title:
On the minimum output entropy of single-mode phase-insensitive Gaussian
  channels

abstract:
  Recently de Palma et al. [IEEE Trans. Inf. Theory 63, 728 (2017)]
proved---using Lagrange multiplier techniques---that under a non-zero input
entropy constraint, a thermal state input minimizes the output entropy of a
pure-loss bosonic channel. In this note, we present our attempt to generalize
this result to all single-mode gauge-covariant Gaussian channels by using
similar techniques. Unlike the case of the pure-loss channel, we cannot prove
that the thermal input state is the only local extremum of the optimization
problem. %It is unclear to us why the same techniques do not lead to a proof
for amplifier channels. However, we do prove that, if the conjecture holds for
gauge-covariant Gaussian channels, it would also hold for gauge-contravariant
Gaussian channels. The truth of the latter leads to a solution of the triple
trade-off and broadcast capacities of quantum-limited amplifier channels. We
note that de Palma et al. [Phys. Rev. Lett. 118, 160503 (2017)] have now proven
the conjecture for all single-mode gauge-covariant Gaussian channels by
employing a different approach from what we outline here. Proving a multi-mode
generalization of de Palma et al.'s above mentioned result---i.e., given a
lower bound on the von Neumann entropy of the input to an $n$-mode lossy
thermal-noise bosonic channel, an $n$-mode product thermal state input
minimizes the output entropy---will establish an important special case of the
conjectured Entropy Photon-number Inequality (EPnI). The EPnI, if proven true,
would take on a role analogous to Shannon's EPI in proving coding theorem
converses involving quantum limits of classical communication over bosonic
channels.


title: 197 Candidates and 104 Validated Planets in K2's First Five Fields

abstract:
  We present 197 planet candidates discovered using data from the first year of
the NASA K2 mission (Campaigns 0-4), along with the results of an intensive
program of photometric analyses, stellar spectroscopy, high-resolution imaging,
and statistical validation. We distill these candidates into sets of 104
validated planets (57 in multi-planet systems), 30 false positives, and 63
remaining candidates. Our validated systems span a range of properties, with
median values of R_P = 2.3 R_E, P=8.6 d, Tef = 5300 K, and Kp=12.7 mag. Stellar
spectroscopy provides precise stellar and planetary parameters for most of
these systems. We show that K2 has increased by 30% the number of small planets
known to orbit moderately bright stars (1-4 R_E, Kp=9-13 mag). Of particular
interest are 37 planets smaller than 2 R_E, 15 orbiting stars brighter than
Kp=11.5, five receiving Earth-like irradiation levels, and several multi-planet
systems -- including four planets orbiting the M dwarf K2-72 near mean-motion
resonances. By quantifying the likelihood that each candidate is a planet we
demonstrate that our candidate sample has an overall false positive rate of
15-30%, with rates substantially lower for small candidates (< 2 R_E) and
larger for candidates with radii > 8 R_E and/or with P < 3 d. Extrapolation of
the current planetary yield suggests that K2 will discover between 500-1000
planets in its planned four-year mission -- assuming sufficient follow-up
resources are available. Efficient observing and analysis, together with an
organized and coherent follow-up strategy, is essential to maximize the
efficacy of planet-validation efforts for K2, TESS, and future large-scale
surveys.


title:
The Aerogel Cherenkov Detector for the SHMS magnetic spectrometer in
  Hall C at Jefferson Lab

abstract:
  Hadronic reactions producing strange quarks such as exclusive or
semi-inclusive kaon production, play an important role in studies of hadron
structure and the dynamics that bind the most basic elements of nuclear
physics. The small-angle capability of the new Super High Momentum Spectrometer
(SHMS) in Hall C, coupled with its high momentum reach - up to the anticipated
11-GeV beam energy in Hall C - and coincidence capability with the
well-understood High Momentum Spectrometer, will allow for probes of such
hadron structure involving strangeness down to the smallest distance scales to
date. To cleanly select the kaons, a threshold aerogel Cerenkov detector has
been constructed for the SHMS. The detector consists of an aerogel tray
followed by a diffusion box. Four trays for aerogel of nominal refractive
indices of n=1.030, 1.020, 1.015 and 1.011 were constructed. The tray
combination will allow for identification of kaons from 1 GeV/c up to 7.2
GeV/c, reaching 10^-2 proton and 10^-3 pion rejection, with kaon detection
efficiency better than 95%. The diffusion box of the detector is equipped with
14 five-inch diameter photomultiplier tubes. Its interior walls are covered
with Gore diffusive reflector, which is superior to the commonly used Millipore
paper and improved the detector performance by 35%. The inner surface of the
two aerogel trays with higher refractive index is covered with Millipore paper,
however, those two trays with lower aerogel refractive index are again covered
with Gore diffusive reflector for higher performance. The measured mean number
of photoelectrons in saturation is ~12 for n=1.030, ~sim8 for n=1.020, ~10 for
n=1.015, and ~5.5 for n=1.011. The design details, the results of component
characterization, and initial performance tests and optimization of the
detector are presented.


title:
Theory of neutrino emission from nucleon-hyperon matter in neutron
  stars: Angular integrals

abstract:
  Investigations of thermal evolution of neutron stars with hyperon cores
require neutrino emissivities for many neutrino reactions involving strongly
degenerate particles (nucleons, hyperons, electrons, muons). We calculate the
angular integrals $I_n$ (over orientations of momenta of $n$ degenerate
particles) for major neutrino reactions with $n$ =3, 4, 5 at all possible
combinations of particle Fermi momenta. The integrals $I_n$ are necessary
ingredients for constructing a uniform database of neutrino emissivities in
dense nucleon-hyperon matter. The results can also be used in many problems of
physical kinetics of strongly degenerate systems.


title:
The i-V curve curve characteristics of burner-stabilized premixed
  flames: detailed and reduced models

abstract:
  The i-V curve describes the current drawn from a flame as a function of the
voltage difference applied across the reaction zone. Since combustion
diagnostics and flame control strategies based on electric fields depend on the
amount of current drawn from flames, there is significant interest in modeling
and understanding i-V curves. We implement and apply a detailed model for the
simulation of the production and transport of ions and electrons in one
dimensional premixed flames. An analytical reduced model is developed based on
the detailed one, and analytical expressions are used to gain insight into the
characteristics of the i-V curve for various flame configurations. In order for
the reduced model to capture the spatial distribution of the electric field
accurately, the concept of a dead zone region, where voltage is constant, is
introduced, and a suitable closure for the spatial extent of the dead zone is
proposed and validated. The results from the reduced modeling framework are
found to be in good agreement with those from the detailed simulations. The
saturation voltage is found to depend significantly on the flame location
relative to the electrodes, and on the sign of the voltage difference applied.
Furthermore, at sub-saturation conditions, the current is shown to increase
linearly or quadratically with the applied voltage, depending on the flame
location. These limiting behaviors exhibited by the reduced model elucidate the
features of i-V curves observed experimentally. The reduced model relies on the
existence of a thin layer where charges are produced, corresponding to the
reaction zone of a flame. Consequently, the analytical model we propose is not
limited to the study of premixed flames, and may be applied easily to others
configurations, e.g. nonpremixed counterflow flames.


title: A superpowered Euclidean prime generator

abstract:
  When $k>1$ and $n$ is the product of the smallest $k$ primes, the $(k+1)$-st
smallest prime is the least divisor exceeding $1$ of $n^{n^n}-1$. This variant
of Euclid's prime generator is discussed with some of its cousins.


title:
Strong-coupling scale and frame-dependence of the initial conditions for
  chaotic inflation in models with modified (coupling to) gravity

abstract:
  A classical evolution in chaotic inflationary models starts at high energy
densities with semi-classical initial conditions presumably consistent with
universal quantum nature of all the fundamental forces. That is each quantum
contributes the same amount to the energy density. We point out the upper limit
on this amount inherent in this approach, so that all the quanta are inside the
weak-coupling domain. We discuss this issue in realistic models with modified
gravity, $R^2$- and Higgs-inflations, emphasizing the specific change of the
initial conditions with metric frame, while all the quanta still contribute
equal parts. The analysis can be performed straightforwardly in any model with
modified gravity ($F(R)$-gravity, scalars with non-minimal couplings to
gravity, etc).


title: Diffractive triangulation of radiative point sources

abstract:
  We describe a general method to determine the location of a point source of
waves relative to a two-dimensional active pixel detector. Based on the
inherent structural sensitivity of crystalline sensor materials, characteristic
detector diffraction patterns can be used to triangulate the location of a wave
emitter. As a practical application of the wide-ranging principle, a digital
hybrid pixel detector is used to localize a source of electrons for Kikuchi
diffraction pattern measurements in the scanning electron microscope. This
provides a method to calibrate Kikuchi diffraction patterns for accurate
measurements of microstructural crystal orientations, strains, and phase
distributions.


title:
Rare correlated sequences detection with DSSSD detector in a real-time
  mode at the Dubna gas-filled recoil separator

abstract:
  Method of active correlations is a key one to suppress radically beam
associated backgrounds in heavy ion induced complete fusion nuclear reactions.
This property is enhanced significantly when applying DSSSD detector instead of
position sensitive resistive strip detector. Example of application in the
240Pu+48Ca->114+3n reaction is presented. An edge effect between neighbor
strips is considered too. The value of the mentioned effect is measured as 15.9
percents for ER-alpha correlation chains. C++ Builder GFS2016 program package
for spectral analysis is presented. Calibration parameters (totally 352) were
obtained from natYb+48Ca nuclear reaction. New ultra intense FLNR DC280
cyclotron that is expected to be put into operation in the nearest future is
also discussed from the viewpoint of the described method developments.