title: Knowledge Completion for Generics using Guided Tensor Factorization

abstract:
  Given a knowledge base or KB containing (noisy) facts about common nouns or
generics, such as "all trees produce oxygen" or "some animals live in forests",
we consider the problem of inferring additional such facts at a precision
similar to that of the starting KB. Such KBs capture general knowledge about
the world, and are crucial for various applications such as question answering.
Different from commonly studied named entity KBs such as Freebase, generics KBs
involve quantification, have more complex underlying regularities, tend to be
more incomplete, and violate the commonly used locally closed world assumption
(LCWA). We show that existing KB completion methods struggle with this new
task, and present the first approach that is successful. Our results
demonstrate that external information, such as relation schemas and entity
taxonomies, if used appropriately, can be a surprisingly powerful tool in this
setting. First, our simple yet effective knowledge guided tensor factorization
approach achieves state-of-the-art results on two generics KBs (80% precise)
for science, doubling their size at 74%-86% precision. Second, our novel
taxonomy guided, submodular, active learning method for collecting annotations
about rare entities (e.g., oriole, a bird) is 6x more effective at inferring
further new facts about them than multiple active learning baselines.


title:
Opportunistic Channel Sharing in Stochastic Networks with Dynamic
  Traffic

abstract:
  In this paper, we consider the stochastic network with dynamic traffic. The
spatial distribution of access points (APs) and users are first modeled as
mutually independent Poisson point processes (PPPs). Different from most
previous literatures which assume all the APs are fully loaded, we consider the
fact that APs having no data to transmit do not generate interference to users.
The APs opportunistically share the channel according to the existence of the
packet to be transmitted and the proposed interference suppression strategy. In
the interference suppression region, only one AP can be active at a time to
transmit the packet on the channel and the other adjacent APs keep silent to
reduce serious interference. The idle probability of any AP, influenced by the
traffic load and availability of the channels, is analyzed. The density of
simultaneously active APs in the network is obtained and the packet loss rate
is further elaborated. We reveal the impacts of network features (e.g., AP
density, user density and channel state) and service features (e.g., user
request, packet size) on the network performance. Simulation results validate
our proposed model.


title: Abstract matrix-tree theorem

abstract:
  The classical matrix-tree theorem discovered by G.Kirchhoff in 1847 relates
the principal minor of the nxn Laplace matrix to a particular sum of monomials
of matrix elements indexed by directed trees with n vertices and a single sink.
In this paper we consider a generalization of this statement: for any k \ge n
we define a degree k polynomial det_{n,k} of matrix elements and prove that
this polynomial applied to the Laplace matrix gives a sum of monomials indexed
by acyclic graphs with n vertices and k edges.


title:
Interaction between antiprotonic helium ion and He atom: Potential
  Energy Surface

abstract:
  Potential Energy Surface for the ($\mathrm{\bar{p}} - \mathrm{He}^{2+} -
\mathrm{He}$) system is calculated in the framework of the restricted (singlet
spin state) Hartree-Fock method with subsequent account of the electronic
correlations within the second order perturbation method (MP2). The geometry of
heavy particles is described in variables of distance $r$ from nucleus $a$ to
antiproton, distance $R$ from the center of mass of the $(\bar{p} - a)$ pair to
$\mathrm{He}$ atom containing nucleus $b$, and an angle $\theta$ between
$\mathbf{r}$ and $\mathbf{R}$. The potential $V(R,r,\cos\theta)$ of the
interaction between $\mathrm{He}$ atom and a $\bar{p} - a$ subsystem involves a
total energy of two electrons in the field of three heavy particles and Coulomb
interactions of the $b$ nucleus with antiproton and the $a$ nucleus. The
expansion of this potential in terms of Legendre polynomials
$\mathrm{P}_k(\cos\theta)$ is obtained. Matrices of the multipole terms
$V^k(r,R)$ ($k=0,1,2$) are obtained in the basis of antiprotonic helium ion
states. The results are compared with the model potential that was used earlier
in the calculations of collisional Stark transitions of
$(\mathrm{\bar{p}He}^{2+})$ ion.Total cross sections of collisional Stark
transitions obtained with the PES potentials exceed the model results by 15 -
20\% at $E \leq 12$ K.


title: Conditional Mutual Information and Quantum Steering

abstract:
  Quantum steering has recently been formalized in the framework of a resource
theory of steering, and several quantifiers have already been introduced. Here,
we propose an information-theoretic quantifier for steering called intrinsic
steerability, which uses conditional mutual information to measure the
deviation of a given assemblage from one having a local hidden-state model. We
thus relate conditional mutual information to quantum steering and introduce
monotones that satisfy certain desirable properties. The idea behind the
quantifier is to suppress the correlations that can be explained by an
inaccessible quantum system and then quantify the remaining intrinsic
correlations. A variant of the intrinsic steerability finds operational meaning
as the classical communication cost of sending the measurement choice and
outcome to an eavesdropper who possesses a purifying system of the underlying
bipartite quantum state that is being measured.


title:
eXtended Variational Quasicontinuum Methodology for Lattice Networks
  with Damage and Crack Propagation

abstract:
  Lattice networks with dissipative interactions are often employed to analyze
materials with discrete micro- or meso-structures, or for a description of
heterogeneous materials which can be modelled discretely. They are, however,
computationally prohibitive for engineering-scale applications. The
(variational) QuasiContinuum (QC) method is a concurrent multiscale approach
that reduces their computational cost by fully resolving the (dissipative)
lattice network in small regions of interest while coarsening elsewhere. When
applied to damageable lattices, moving crack tips can be captured by adaptive
mesh refinement schemes, whereas fully-resolved trails in crack wakes can be
removed by mesh coarsening. In order to address crack propagation efficiently
and accurately, we develop in this contribution the necessary generalizations
of the variational QC methodology. First, a suitable definition of crack paths
in discrete systems is introduced, which allows for their geometrical
representation in terms of the signed distance function. Second, special
function enrichments based on the partition of unity concept are adopted, in
order to capture kinematics in the wakes of crack tips. Third, a summation rule
that reflects the adopted enrichment functions with sufficient degree of
accuracy is developed. Finally, as our standpoint is variational, we discuss
implications of the mesh refinement and coarsening from an energy-consistency
point of view. All theoretical considerations are demonstrated using two
numerical examples for which the resulting reaction forces, energy evolutions,
and crack paths are compared to those of the direct numerical simulations.


title:
Searches for pair production of third-generation squarks in sqrt(s) = 13
  TeV pp collisions

abstract:
  Searches are presented for direct production of top or bottom squark pairs in
proton-proton collisions at the CERN LHC. Two searches, based on complementary
techniques, are performed in all-jet final states that are characterized by a
significant imbalance in transverse momentum. An additional search requires the
presence of a charged lepton isolated from other activity in the event. The
data were collected in 2015 at a centre-of-mass energy of 13 TeV with the CMS
detector and correspond to an integrated luminosity of 2.3 inverse femtobarns.
No statistically significant excess of events is found beyond the expected
contribution from standard model processes. Exclusion limits are set in the
context of simplified models of top or bottom squark pair production. Models
with top and bottom squark masses up to 830 and 890 GeV, respectively, are
probed for light neutralinos. For models with top squark masses of 675 GeV,
neutralino masses up to 260 GeV are excluded at 95% confidence level.


title: Forward hadron production in pA collisions beyond leading order

abstract:
  In this talk, we report our recent progress on pinning down the cause of
negativity in the NLO single inclusive hadron production in pA collisions at
forward rapidity.


title: Multi-centered AdS$_3$ solutions from Virasoro conformal blocks

abstract:
  We revisit the construction of multi-centered solutions in three-dimensional
anti-de Sitter gravity in the light of the recently discovered connection
between particle worldlines and classical Virasoro conformal blocks. We focus
on multi-centered solutions which represent the backreaction of point masses
moving on helical geodesics in global AdS$_3$, and argue that their
construction reduces to a problem in Liouville theory on the disk with
Zamolodchikov-Zamolodchikov boundary condition. In order to construct the
solution one needs to solve a certain monodromy problem which we argue is
solved by a vacuum classical conformal block on the sphere in a particular
channel. In this way we construct multi-centered gravity solutions by using
conformal blocks special functions. We show that our solutions represent
left-right asymmetric configurations of operator insertions in the dual CFT. We
also provide a check of our arguments in an example and comment on other types
of solutions.


title: Exact recovery in the Ising blockmodel

abstract:
  We consider the problem associated to recovering the block structure of an
Ising model given independent observations on the binary hypercube. This new
model, called the Ising blockmodel, is a perturbation of the mean field
approximation of the Ising model known as the Curie-Weiss model: the sites are
partitioned into two blocks of equal size and the interaction between those of
the same block is stronger than across blocks, to account for more order within
each block. We study probabilistic, statistical and computational aspects of
this model in the high-dimensional case when the number of sites may be much
larger than the sample size.


title:
Anomalous thermal conductivity and magnetic torque response in the
  honeycomb magnet $\alpha$-RuCl$_3$

abstract:
  We report on the unusual behavior of the in-plane thermal conductivity
($\kappa$) and torque ($\tau$) response in the Kitaev-Heisenberg material
$\alpha$-RuCl$_3$. $\kappa$ shows a striking enhancement with linear growth
beyond H = 7 T, where magnetic order disappears, while $\tau$ for both of the
in-plane symmetry directions shows an anomaly at the same field. The
temperature- and field-dependence of $\kappa$ are far more complex than
conventional phonon and magnon contributions, and require us to invoke the
presence of unconventional spin excitations whose properties are characteristic
of a field-induced spin-liquid phase related to the enigmatic physics of the
Kitaev model in an applied magnetic field


title:
Unified Framework for the Effective Rate Analysis of Wireless
  Communication Systems over MISO Fading Channels

abstract:
  This paper proposes a unified framework for the effective rate analysis over
arbitrary correlated and not necessarily identical multiple inputs single
output (MISO) fading channels, which uses moment generating function (MGF)
based approach and H transform representation. The proposed framework has the
potential to simplify the cumbersome analysis procedure compared to the
probability density function (PDF) based approach. Moreover, the effective
rates over two specific fading scenarios are investigated, namely independent
but not necessarily identical distributed (i.n.i.d.) MISO hyper Fox's H fading
channels and arbitrary correlated generalized K fading channels. The exact
analytical representations for these two scenarios are also presented. By
substituting corresponding parameters, the effective rates in various practical
fading scenarios, such as Rayleigh, Nakagami-m, Weibull/Gamma and generalized K
fading channels, are readily available. In addition, asymptotic approximations
are provided for the proposed H transform and MGF based approach as well as for
the effective rate over i.n.i.d. MISO hyper Fox's H fading channels.
Simulations under various fading scenarios are also presented, which support
the validity of the proposed method.


title:
Application of the complex scaling method in solving three-body Coulomb
  scattering problem

abstract:
  The three-body scattering problem in Coulombic systems is widespread, however
yet unresolved problem by the mathematically rigorous methods. In this work
this long term challenge has been undertaken by combining distorted waves and
Faddeev-Merkuriev equation formalisms in conjunction with the complex scaling
technique to overcome difficulties related with the boundary conditions. Unlike
the common belief, it is demonstrated that the smooth complex scaling method
can be applied to solve three-body Coulomb scattering problem in a wide energy
region, including fully elastic domain and extending to the energies well
beyond atom ionization threshold.
  Newly developed method is used to study electron scattering on ground states
of Hydrogen and Positronium atoms as well as a $e^+$+H(n=1) $\rightleftarrows$
p+Ps(n=1) reaction. Where available, obtained results are compared with the
experimental data and theoretical predictions, proving accuracy and efficiency
of the newly developed method.


title: The production rate of the system-bath mutual information

abstract:
  When an open system is contacted with several thermal baths, the entropy
produced by the irreversible processes
($dS_{\mathrm{i}}=dS-\sum_{\alpha}\text{\dj}Q_{\alpha}/T_{\alpha}$) keeps
increasing, and this entropy production rate is always non-negative. But when
the system is contacted with some non-thermal baths containing quantum
coherence or squeezing, this entropy production formula does not apply. In this
paper, we study the increasing rate of the mutual information between the open
system and its environment. When the baths are canonical thermal ones, we prove
that this mutual information production rate could exactly return to the
previous entropy production rate. Further, we study an example of a single
boson mode contacted with multiple squeezed thermal baths, where the
conventional entropy production rate does not apply, and we find that this
mutual information production rate still keeps non-negative, which means the
monotonic increasing of the correlation between the system and its environment.


title: Uniqueness from locality and BCFW shifts

abstract:
  We introduce a BCFW shift which can be used to recursively build the full
Yang-Mills tree-level amplitude as a function of polarization vectors.
Furthermore, in line with the recent results of arXiv:1612.02797, we conjecture
that the Yang-Mills tree-level scattering amplitude is uniquely fixed by
locality and demanding the usual asymptotic behavior under a sufficient number
of shifts. Unitarity therefore emerges from locality and constructability. We
prove this statement at the leading order in the soft expansion.


title: Full action of two deformation operators in the D1D5 CFT

abstract:
  We are interested in thermalization in the D1D5 CFT, since this process is
expected to be dual to black hole formation. We expect that the lowest order
process where thermalization occurs will be at second order in the perturbation
that moves us away from the orbifold point. The operator governing the
deformation off of the orbifold point consists of a twist operator combined
with a supercharge operator acting on this twist. In a previous paper we
computed the action of two twist operators on an arbitrary state of the CFT. In
the present work we compute the action of the supercharges on these twist
operators, thereby obtaining the full action of two deformation operators on an
arbitrary state of the CFT. We show that the full amplitude can be related to
the amplitude with just the twists through an action of the supercharge
operators on the initial and final states. The essential part of this
computation consists of moving the contours from the twist operators to the
initial and final states; to do this one must first map the amplitude to a
covering space where the twists are removed, and then map back to the original
space on which the CFT is defined.


title:
HILDCAA* events between 1998 and 2007 and their related interplanetary
  magnetic field and plasma values

abstract:
  We investigate the interplanetary conditions during 135 less strict
high-intensity, long-duration, continuous AE activity (HILDCAA*) events between
the years 1998-2007. The HILDCAA* events were chosen by following the three
"traditional" criteria which describe the high-intensity, long-duration,
continuous AE activity (HILDCAA). However, we include a small modification in
the criteria that considers: "the AE values do not drop below 200 nT for more
than 2 h at a time". This criteria is modified by changing 2 to 4 hours period
in which the AE values should not drop below 200 nT. Once the events are
selected, we perform a statistical analysis of the interplanetary parameters
during their occurrences. The distribution of HILDCAA* events along the solar
cycle shows a pattern of double peak, with a peak around the maximum of the
sunspot cycle, and an other in the descending phase. This kind of distribution
is similar to the distribution of low-latitude coronal holes. For each of the
HILDCAA* events, we have found its related Interplanetary Magnetic Field (IMF)
and plasma parameter signatures. The average values of AE, AU, AL, and Dst
indices, the density and temperature of the solar wind protons, the solar wind
speed, the Bz component of the IMF, the IMF intensity, dynamic pressure, and
plasma beta, among all the 135 HILDCAA* events, found here are: AE (348.1 $\pm$
67.1 nT), AU (123.9 $\pm$ 34.2 nT), AL (-224.2 $\pm$ 47.3 nT), Dst (-22.1 $\pm$
9.1 nT), Density (4.3 $\pm$ 1.3 cm-3), Temperature (170976.3 $\pm$ 58049.9 K),
Flow speed (547.1 $\pm$ 83.9 km/s), Bz (-0.70 $\pm$ 0.88 nT), IMF magnitude
average (6.6 $\pm$ 1.2 nT), pressure (2.4 $\pm$ 0.6 nPa), and plasma Beta (0.66
$\pm$ 0.27).


title: Triple Gauge Couplings at Future Hadron and Lepton Colliders

abstract:
  The $WW$ production is the primary channel to directly probe the triple gauge
couplings. We analyze the $e^+ e^- \rightarrow W^+ W^-$ process at the proposed
Circular Electron-Positron Collider (CEPC), and find that the anomalous triple
gauge couplings and relevant dimension six operators can be probed up to the
order of $10^{-4}$. We also estimate constraints at the 14 TeV LHC, with both
300 fb$^{-1}$ and 3000 fb$^{-1}$ integrated luminosity from the leading lepton
$p_T$ and azimuthal angle difference $\Delta \phi_{ll}$ in the di-lepton
channel. The constrain is somewhat weaker, up to the order of $10^{-3}$. The
limits on the triple gauge couplings are complementary to those on the
electroweak precision observables and Higgs couplings.


title:
Impact of resonance decays on critical point signals in net-proton
  fluctuations

abstract:
  The non-monotonic beam energy dependence of the higher cumulants of
net-proton fluctuations is a widely studied signature of the conjectured
presence of a critical point in the QCD phase diagram. In this work we study
the effect of resonance decays on critical fluctuations. We show that resonance
effects reduce the signatures of critical fluctuations, but that for reasonable
parameter choices critical effects in the net-proton cumulants survive. The
relative role of resonance decays has a weak dependence on the order of the
cumulants studied with a slightly stronger suppression of critical effects for
higher-order cumulants.


title: Number Density of Peaks in a Chi-Squared Field

abstract:
  We investigate the statistics of stationary points in the sum of squares of
$N$ Gaussian random fields, which we call a "chi-squared" field. The behavior
of such a field at a point is investigated, with particular attention paid to
the formation of topological defects. An integral to compute the number density
of stationary points at a given field amplitude is constructed. We compute
exact expressions for the integral in various limits and provide code to
evaluate it numerically in the general case. We investigate the dependence of
the number density of stationary points on the field amplitude, number of
fields, and power spectrum of the individual Gaussian random fields. This work
parallels the work of Bardeen, Bond, Kaiser and Szalay, who investigated the
statistics of peaks of Gaussian random fields. A number of results for
integrating over matrices are presented in appendices.


title: Loops in AdS from Conformal Field Theory

abstract:
  We propose and demonstrate a new use for conformal field theory (CFT)
crossing equations in the context of AdS/CFT: the computation of loop
amplitudes in AdS, dual to non-planar correlators in holographic CFTs. Loops in
AdS are largely unexplored, mostly due to technical difficulties in direct
calculations. We revisit this problem, and the dual $1/N$ expansion of CFTs, in
two independent ways. The first is to show how to explicitly solve the crossing
equations to the first subleading order in $1/N^2$, given a leading order
solution. This is done as a systematic expansion in inverse powers of the spin,
to all orders. These expansions can be resummed, leading to the CFT data for
finite values of the spin. Our second approach involves Mellin space. We show
how the polar part of the four-point, loop-level Mellin amplitudes can be fully
reconstructed from the leading-order data. The anomalous dimensions computed
with both methods agree. In the case of $\phi^4$ theory in AdS, our crossing
solution reproduces a previous computation of the one-loop bubble diagram. We
can go further, deriving part of the four-point function in $\phi^3+\phi^4$
theory in AdS which had never been computed. In the process, we show how to
analytically derive anomalous dimensions from Mellin amplitudes with an
infinite series of poles, and discuss applications to more complicated cases
such as the ${\cal N}=4$ super-Yang-Mills theory.


title: Spatial heterogeneity of W transmutation in a fusion device

abstract:
  Accurately quantifying the transmutation rate of tungsten (W) under neutron
irradiation is a necessary requirement in the assessment of its performance as
an armour material in a fusion power plant. The usual approach of calculating
average responses, assuming large, homogenised material volumes, is
insufficient to capture the full complexity of the transmutation picture in the
context of a realistic fusion power plant design, particularly for rhenium (Re)
production from W. Combined neutron transport and inventory simulations for
representative {\it spatially heterogeneous} models of a fusion power plant
show that the production rate of Re is strongly influenced by the local spatial
environment. Localised variation in neutron moderation (slowing down) due to
structural steel and coolant, particularly water, can dramatically increase Re
production because of the huge cross sections of giant resolved resonances in
the neutron-capture reaction of \(^{186}\)W at low neutron energies.
Calculations using cross section data corrected for temperature (Doppler)
effects suggest that temperature may have a relatively lesser influence on
transmutation rates.


title:
Phase-sensitive optical time-domain reflectometry with pulse mode EDFA:
  Probe pulse preparation

abstract:
  Probe pulse preparation techniques play an important role for fiber-optic
sensing. In this work, we investigate a setup for distributed sensors based on
phase-sensitive optical time domain reflectometry ($\Phi$-OTDR) with the use of
an erbium doped fibre amplifier (EDFA). In our $\Phi$-OTDR setup with pulse
mode EDFA, we reveal a regime providing us both sufficiently large
amplification of the probe pulse power together and adequately small probe
pulse distortion. We then show that the use of pulse mode EDFA is a
cost-effective solution, which allows one to avoid nonlinear effect and ensure
sufficient sensitivity of the setup.


title: Spectral dimension with deformed spacetime signature

abstract:
  Studies of the effective regime of loop quantum gravity (LQG) revealed that,
in the limit of Planckian curvature scales, spacetime may undergo a transition
from the Lorentzian to Euclidean signature. This effect is a consequence of
quantum modifications of the hypersurface deformation algebra, which in the
linearized case is equivalent to a deformed version of the Poincar\'e algebra.
In this paper the latter relation is applied to the LQG-inspired hypersurface
deformation algebra that is characterized by the above mentioned signature
change.
  While the exact form of the deformed Poincar\'e algebra is not uniquely
determined, the algebra under consideration is representative enough to capture
a number of qualitative features. In particular, the analysis reveals that the
signature change can be associated with two symmetric invariant energy scales,
which separate three physically disconnected momentum subspaces.
  Furthermore, the invariant measure on momentum space is derived, which allows
to properly define the average return probability, characterizing a fictitious
diffusion process on spacetime. The diffusion is subsequently studied in the
momentum representation for all possible variants of the model. Finally, the
spectral dimension of spacetime is calculated in each case as a function of the
scale parameter. In the most interesting case the deformation is of the
asymptotically ultralocal type and the spectral dimension undergoes a reduction
to $d_S = 1$ in the UV limit.


title: Waves in slowly varying band-gap media

abstract:
  This paper is concerned with the asymptotic description of high-frequency
waves in locally periodic media. A key issue is that the Bloch-dispersion
curves vary with the local microstructure, giving rise to hidden singularities
associated with band-gap edges and branch crossings. We describe an asymptotic
approach for overcoming this difficulty, and take a first step by studying in
detail the simplest case of 1D Helmholtz waves. The method entails matching
adiabatically propagating Bloch waves, captured by a multiple-scale
Wentzel-Kramers-Brillouin (WKB) approximation, with complementary
multiple-scale solutions spatially localised about dispersion singularities.
Within the latter regions the Bloch wavenumber is nearly critical; this allows
their homogenisation, following the method of high-frequency homogenisation
(HFH), over a naturally arising scale intermediate between the periodicity
(wavelength) and the macro-scale. Analogously to a classical turning-point
analysis, we show that close to a spatial band-gap edge the solution is an Airy
function, only that it is modulated on the short scale by a standing-wave Bloch
eigenfunction. By carrying out the asymptotic matching between the WKB and HFH
solutions we provide a detailed description of Bloch-wave reflection from a
band gap. Finally, we implement the asymptotic theory for a layered medium and
demonstrate excellent agreement with numerical computations.


title: Fun Facts: Automatic Trivia Fact Extraction from Wikipedia

abstract:
  A significant portion of web search queries directly refers to named
entities. Search engines explore various ways to improve the user experience
for such queries. We suggest augmenting search results with {\em trivia facts}
about the searched entity. Trivia is widely played throughout the world, and
was shown to increase users' engagement and retention.
  Most random facts are not suitable for the trivia section. There is skill
(and art) to curating good trivia. In this paper, we formalize a notion of
\emph{trivia-worthiness} and propose an algorithm that automatically mines
trivia facts from Wikipedia. We take advantage of Wikipedia's category
structure, and rank an entity's categories by their trivia-quality.
  Our algorithm is capable of finding interesting facts, such as Obama's Grammy
or Elvis' stint as a tank gunner. In user studies, our algorithm captures the
intuitive notion of "good trivia" 45\% higher than prior work. Search-page
tests show a 22\% decrease in bounce rates and a 12\% increase in dwell time,
proving our facts hold users' attention.


abstract:
  In this paper, we establish a theoretical connection between the classical
Lucas & Kanade (LK) algorithm and the emerging topic of Spatial Transformer
Networks (STNs). STNs are of interest to the vision and learning communities
due to their natural ability to combine alignment and classification within the
same theoretical framework. Inspired by the Inverse Compositional (IC) variant
of the LK algorithm, we present Inverse Compositional Spatial Transformer
Networks (IC-STNs). We demonstrate that IC-STNs can achieve better performance
than conventional STNs with less model capacity; in particular, we show
superior performance in pure image alignment tasks as well as joint
alignment/classification problems on real-world problems.


title: Internal Delensing of Cosmic Microwave Background Acoustic Peaks

abstract:
  We present a method to delens the acoustic peaks of the CMB temperature and
polarization power spectra internally, using lensing maps reconstructed from
the CMB itself. We find that when delensing CMB acoustic peaks with a lensing
potential map derived from the same CMB sky, a large bias arises in the
delensed power spectrum. The cause of this bias is that the noise in the
reconstructed potential map is derived from, and hence correlated with, the CMB
map when delensing. This bias is more significant relative to the signal than
an analogous bias found when delensing CMB B modes. We calculate the leading
term of this bias, which is present even in the absence of lensing. We also
demonstrate one method to remove this bias, using reconstructions from CMB
angular scales within given ranges to delens CMB scales outside of those
ranges. Some details relevant for a realistic analysis are also discussed, such
as the importance of removing mask-induced effects for successful delensing,
and a useful null test, obtained from randomizing the phases of the
reconstructed potential. Our findings should help current and next-generation
CMB experiments obtain tighter parameter constraints via the internal removal
of lensing-induced smoothing from temperature and E-mode acoustic peaks.


title: Weyl-Kondo Semimetal in Heavy Fermion Systems

abstract:
  Insulating states can be topologically nontrivial, a well-established notion
that is exemplified by the quantum Hall effect and topological insulators. By
contrast, topological metals have not been experimentally evidenced until
recently. In systems with strong correlations, they have yet to be identified.
Heavy fermion semimetals are a prototype of strongly correlated systems and,
given their strong spin-orbit coupling, present a natural setting to make
progress. Here we advance a Weyl-Kondo semimetal phase in a periodic Anderson
model on a noncentrosymmetric lattice. The quasiparticles near the Weyl nodes
develop out of the Kondo effect, as do the surface states that feature Fermi
arcs. We determine the key signatures of this phase, which are realized in the
heavy fermion semimetal Ce$_3$Bi$_4$Pd$_3$. Our findings provide the
much-needed theoretical foundation for the experimental search of topological
metals with strong correlations, and open up a new avenue for systematic
studies of such quantum phases that naturally entangle multiple degrees of
freedom.


title: Deep Supervised Hashing with Triplet Labels

abstract:
  Hashing is one of the most popular and powerful approximate nearest neighbor
search techniques for large-scale image retrieval. Most traditional hashing
methods first represent images as off-the-shelf visual features and then
produce hashing codes in a separate stage. However, off-the-shelf visual
features may not be optimally compatible with the hash code learning procedure,
which may result in sub-optimal hash codes. Recently, deep hashing methods have
been proposed to simultaneously learn image features and hash codes using deep
neural networks and have shown superior performance over traditional hashing
methods. Most deep hashing methods are given supervised information in the form
of pairwise labels or triplet labels. The current state-of-the-art deep hashing
method DPSH~\cite{li2015feature}, which is based on pairwise labels, performs
image feature learning and hash code learning simultaneously by maximizing the
likelihood of pairwise similarities. Inspired by DPSH~\cite{li2015feature}, we
propose a triplet label based deep hashing method which aims to maximize the
likelihood of the given triplet labels. Experimental results show that our
method outperforms all the baselines on CIFAR-10 and NUS-WIDE datasets,
including the state-of-the-art method DPSH~\cite{li2015feature} and all the
previous triplet label based deep hashing methods.


title:
Enhancing the Physical Layer Security of Non-orthogonal Multiple Access
  in Large-Scale Networks

abstract:
  This paper investigates the physical layer security of non-orthogonal
multiple access (NOMA) in large-scale networks with invoking stochastic
geometry. Both single-antenna and multiple-antenna aided transmission scenarios
are considered, where the base station (BS) communicates with randomly
distributed NOMA users. In the single-antenna scenario, we adopt a protected
zone around the BS to establish an eavesdropper-exclusion area with the aid of
careful channel-ordering of the NOMA users. In the multiple-antenna scenario,
artificial noise is generated at the BS for further improving the security of a
beamforming-aided system. In order to characterize the secrecy performance, we
derive new exact expressions of the security outage probability for both
single-antenna and multiple-antenna aided scenarios. To obtain further
insights, 1) for the single antenna scenario, we perform secrecy diversity
order analysis of the selected user pair. The analytical results derived
demonstrate that the secrecy diversity order is determined by the specific user
having the worse channel condition among the selected user pair; and 2) for the
multiple-antenna scenario, we derive the asymptotic secrecy outage probability,
when the number of transmit antennas tends to infinity. Monte Carlo simulations
are provided for verifying the analytical results derived and to show that:
i)~The security performance of the NOMA networks can be improved by invoking
the protected zone and by generating artificial noise at the BS; and ii)~The
asymptotic secrecy outage probability is close to the exact secrecy outage
probability.


title:
Design of Data-Driven Mathematical Laws for Optimal Statistical
  Classification Systems

abstract:
  This article will devise data-driven, mathematical laws that generate
optimal, statistical classification systems which achieve minimum error rates
for data distributions with unchanging statistics. Thereby, I will design
learning machines that minimize the expected risk or probability of
misclassification. I will devise a system of fundamental equations of binary
classification for a classification system in statistical equilibrium. I will
use this system of equations to formulate the problem of learning unknown,
linear and quadratic discriminant functions from data as a locus problem,
thereby formulating geometric locus methods within a statistical framework.
Solving locus problems involves finding equations of curves or surfaces defined
by given properties and finding graphs or loci of given equations. I will
devise three systems of data-driven, locus equations that generate optimal,
statistical classification systems. Each class of learning machines satisfies
fundamental statistical laws for a classification system in statistical
equilibrium. Thereby, I will formulate three classes of learning machines that
are scalable modules for optimal, statistical pattern recognition systems, all
of which are capable of performing a wide variety of statistical pattern
recognition tasks, where any given M-class statistical pattern recognition
system exhibits optimal generalization performance for an M-class feature
space.


title:
Spreading out and staying sharp - Creating diverse rotation curves via
  baryonic and self-interaction effects

abstract:
  Galactic rotation curves are a fundamental constraint for any cosmological
model. We use controlled N-body simulations of galaxies to study the
gravitational effect of baryons in a scenario with collisionless cold dark
matter (CDM) versus one with a self-interacting dark matter (SIDM) component.
In particular, we examine the inner profiles of the rotation curves in the
velocity range Vmax = 30-250 km/s, whose diversity has been found to be greater
than predicted by the Lambda-CDM scenario. We find that the scatter in the
observed rotation curves exceeds that predicted by dark matter only
mass-concentration relations in either the CDM nor SIDM models. Allowing for
realistic baryonic content and spatial distributions, however, helps create a
large variety of rotation curve shapes; which is in better agreement with
observations in the case of self-interactions due to the characteristic cored
profiles being more accommodating to the slowly rising rotation curves than
CDM. We find individual fits to model two of the most remarkable outliers of
similar Vmax, UGC 5721 and IC 2574, the former a cusp-like rotation curve and
the latter a seemingly 8 kpc cored profile. This diversity in SIDM arises as
permutations of overly concentrated halos with compact baryonic distributions
versus underdense halos with extended baryonic disks. The SIDM solution is
promising and its feasibility ultimately depends on the sampling of the halo
mass-concentration relation and its interplay with the baryonic profiles,
emphasising the need for a better understanding of the frequency of extreme
outliers present in current observational samples.


title:
On a consistent estimator of a useful signal in Ornstein-Uhlenbeck model
  in $\mathbb{C}[-l,l[$

abstract:
  ~It is considered a transmittion process of a useful signal in
Ornstein-Uhlenbeck model in $\mathbb{C}[-l,l[$ defined by the stochastic
differential equation $$ d\Psi(t,x,\omega)=\sum_{n=0}^{2m}
A_n\frac{\partial^{n}}{\partial x^{n}}\Psi(t,x,\omega)dt +\sigma d W(t,\omega)
$$ with initial condition $$\Psi(0,x,\omega)=\Psi_0(x) \in FD^{(0)}[-l,l[, $$
where $m \ge 1$, $(A_n)_{0 \le n \le 2m} \in \mathbb{R}^+\times
\mathbb{R}^{2m-1}$,$~((t,x,\omega) \in [0,+\infty[\times [-l,l[ \times
\Omega)$, $\sigma \in \mathbb{R}^+$, $\mathbb{C}[-l,l[$ is Banach space of all
real-valued bounded continuous functions on $[-l,l[$, $FD^{(0)}[-l,l[ \subset
\mathbb{C}[-l,l[ $ is class of all real-valued bounded continuous functions on
$[-l,l[$ whose Fourier series converges to himself everywhere on $[-l,l[$,
$(W(t,\omega))_{t \ge 0}$ is a Wiener process and $\Psi_0(x)$ is a useful
signal.
  By use a sequence of transformed signals $(Z_k)_{k \in
N}=(\Psi(t_0,x,\omega_k))_{k \in N}$ at moment $t_0>0$, consistent and
infinite-sample consistent estimations of the useful signal $\Psi_0$ is
constructed under assumption that parameters $(A_n)_{0 \le n \le 2m}$ and
$\sigma$ are known. Animation and simulation of the Ornstein-Uhlenbeck process
in $\mathbb{C}[-l,l[$ and an estimation of a useful signal are also presented.


title:
DIAPHANE: Muon tomography applied to volcanoes, civil engineering,
  archaelogy

abstract:
  Muography techniques applied to geological structures greatly improved in the
past ten years. Recent applications demonstrate the interest of the method not
only to perform structural imaging but also to monitor the dynamics of inner
movements like magma ascent inside volcanoes or density variations in
hydrothermal systems. Muography time-resolution has been studied thanks to
dedicated experiments, e.g. in a water tower tank. This paper presents the
activities of the DIAPHANE collaboration between particle- and geo-physicists
and the most recent results obtained in the field of volcanology, with a focus
on the main target, the Soufri\`ere of Guadeloupe active volcano. Special
emphasis is given on the monitoring of the dome's inner volumes opacity
variations, that could be inferred to the hydrothermal system dynamics
(vaporization of inner liquid water in coincidence with the appearance of new
fumaroles at the summit). I also breifly present results obtained in the fields
of civil engineering (study of urban underground tunnels) and archaelogy (greek
tumulus scanning).

categories: physics.geo-ph hep-ex hep-ph physics.data-an physics.ins-det


title:
Cosmic particle colliders: simulations of self-interacting dark matter
  with anisotropic scattering

abstract:
  We investigate how self-interacting dark matter (SIDM) with anisotropic
scattering affects the evolution of isolated dark matter haloes as well as
systems with two colliding haloes. For isolated haloes, we find that the
evolution can be adequately captured by treating the scattering as isotropic,
as long as the isotropic cross-section is appropriately matched to the
underlying anisotropic model. We find that this matching should not be done
using the momentum transfer cross-section, as has been done previously.
Matching should instead be performed via a modified momentum transfer
cross-section that takes into account that dark matter particles can be
relabelled after they scatter, without altering the dynamics. However, using
cross-sections that are matched to give the same behaviour in isolated haloes,
we find that treating dark matter scattering as isotropic under-predicts the
effects of anisotropic dark matter scattering when haloes collide. In
particular, the DM-galaxy offset induced by SIDM in colliding galaxy clusters
is larger when we simulate the underlying particle model, than if we use a
matched isotropic model. On the other hand, well motivated particle models with
anisotropic scattering typically have cross-sections with a strong velocity
dependence, and we discover a previously unrecognised effect that suppresses
DM-galaxy offsets in colliding clusters making it hard for these systems to
provide competitive constraints on such particle models.


title: A Transient Transit Signature Associated with the Young Star RIK-210

abstract:
  We find transient, transit-like dimming events within the K2 time series
photometry of the young star RIK-210 in the Upper Scorpius OB association.
These dimming events are variable in depth, duration, and morphology. High
spatial resolution imaging revealed the star is single, and radial velocity
monitoring indicated that the dimming events can not be due to an eclipsing
stellar or brown dwarf companion. Archival and follow-up photometry suggest the
dimming events are transient in nature. The variable morphology of the dimming
events suggests they are not due to a single, spherical body. The ingress of
each dimming event is always shallower than egress, as one would expect for an
orbiting body with a leading tail. The dimming events are periodic and
synchronous with the stellar rotation. However, we argue it is unlikely the
dimming events could be attributed to anything on the stellar surface based on
the observed depths and durations. Variable obscuration by a protoplanetary
disk is unlikely on the basis that the star is not actively accreting and lacks
the infrared excess associated with an inner disk. Rather, we explore the
possibilities that the dimming events are due to magnetospheric clouds, a
transiting protoplanet surrounded by circumplanetary dust and debris, eccentric
orbiting bodies undergoing periodic tidal disruption, or an extended field of
dust or debris near the corotation radius.


title: Modeling coherent errors in quantum error correction

abstract:
  Analysis of quantum error correcting codes is typically done using a
stochastic, Pauli channel error model for describing the noise on physical
qubits. However, it was recently found that coherent errors (systematic
rotations) on physical data qubits result in both physical and logical error
rates that differ significantly from those predicted by a Pauli model. Here we
examine the accuracy of the Pauli approximation for coherent errors on data
qubits under the repetition code. We analytically evaluate the logical error as
a function of concatenation level and code distance. We find that coherent
errors result in logical errors that are partially coherent and therefore
non-Pauli. However, the coherent part of the error is negligible after two or
more concatenation levels or at fewer than $\epsilon^{-(d-1)}$ error correction
cycles, where $\epsilon \ll 1$ is the rotation angle error per cycle for a
single physical qubit and $d$ is the code distance. These results lend support
to the validity of modeling coherent errors using a Pauli channel under some
minimum requirements for code distance and/or concatenation.


title:
Using the outskirts of galaxy clusters to determine their mass accretion
  rate

abstract:
  We explore the possibility of using the external regions of galaxy clusters
to measure their mass accretion rate (MAR). The main goal is to provide a
method to observationally investigate the growth of structures on the nonlinear
scales of galaxy clusters. We derive the MAR by using the mass profile beyond
the splashback radius, evaluating the mass of a spherical shell and the time it
takes to fall in. The infall velocity of the shell is extracted from $N$-body
simulations. The average MAR returned by our prescription in the redshift range
$z=[0, 2]$ is within $20-40 \%$ of the average MAR derived from the merger
trees of dark matter haloes in the reference $N$-body simulations. Our result
suggests that the external regions of galaxy clusters can be used to measure
the mean MAR of a sample of clusters.


title:
A numerical scheme for the compressible low-Mach number regime of ideal
  fluid dynamics

abstract:
  Based on the Roe solver a new technique that allows to correctly represent
low Mach number flows with a discretization of the compressible Euler equations
was proposed in Miczek et al.: New numerical solver for flows at various mach
numbers. A&A 576, A50 (2015). We analyze properties of this scheme and
demonstrate that its limit yields a discretization of the continuous limit
system. Furthermore we perform a linear stability analysis for the case of
explicit time integration and study the performance of the scheme under
implicit time integration via the evolution of its condition number. A
numerical implementation demonstrates the capabilities of the scheme on the
example of the Gresho vortex which can be accurately followed down to Mach
numbers of ~1e-10 .

categories: math.NA astro-ph.SR physics.comp-ph physics.flu-dyn


title:
Supernova ejecta with a relativistic wind from a central compact object:
  a unified picture for extraordinary supernovae

abstract:
  The hydrodynamical interaction between freely expanding supernova ejecta and
a relativistic wind injected from the central region is studied in analytic and
numerical ways. As a result of the collision between the ejecta and the wind, a
geometrically thin shell surrounding a hot bubble forms and expands in the
ejecta. We use a self-similar solution to describe the early dynamical
evolution of the shell and carry out a two-dimensional special relativistic
hydrodynamic simulation to follow further evolution. The Rayleigh-Taylor
instability inevitably develops at the contact surface separating the shocked
wind and ejecta, leading to the complete destruction of the shell and the
leakage of hot gas from the hot bubble. The leaking hot materials immediately
catch up with the outermost layer of the supernova ejecta and thus different
layers of the ejecta are mixed. We present the spatial profiles of
hydrodynamical variables and the kinetic energy distributions of the ejecta. We
stop the energy injection when a total energy of $10^{52}$ erg, which is 10
times larger than the initial kinetic energy of the supernova ejecta, is
deposited into the ejecta and follow the subsequent evolution. From the results
of our simulations, we consider expected emission from supernova ejecta powered
by the energy injection at the centre and discuss the possibility that
superluminous supernovae and broad-lined Ic supernovae could be produced by
similar mechanisms.


title: Hall-effect Mediated Magnetic Flux Transport in Protoplanetary Disks

abstract:
  The global evolution of protoplanetary disks (PPDs) has recently been shown
to be largely controlled by the amount of poloidal magnetic flux threading the
disk, which is further controlled by the poorly understood process of magnetic
flux transport. In weakly ionized gas as in PPDs, magnetic flux is largely
frozen in the electron fluid, except when resistivity is large. When the disk
is largely laminar, we show that the relative drift between the electrons and
ions (the Hall-drift), and the ions and neutral fluids (ambipolar-drift) can
play a dominant role on the transport of magnetic flux. Using two-dimensional
simulations that incorporate the Hall effect and ambipolar diffusion (AD) with
prescribed diffusivities, we show that when large-scale poloidal field is
aligned with disk rotation, the Hall effect rapidly drags magnetic flux inward
at the midplane region, while it slowly pushes flux outward above/below the
midplane. This leads to a highly radially elongated field configuration as a
global manifestation of the Hall-shear instability. This field configuration
further promotes rapid outward flux transport by AD at the midplane, leading to
instability saturation. In quasi-steady state, magnetic flux is transported
outward at approximately the same rate at all heights, and the rate is
comparable to the Hall-free case. For anti-aligned field polarity, the Hall
effect consistently transports magnetic flux outward, leading to a largely
vertical field configuration in the midplane region. The field lines in the
upper layer first bend radially inward and then outward to launch a disk wind.
Overall, the net rate of outward flux transport is about twice faster than the
aligned case. In addition, the rate of flux transport increases with increasing
disk magnetization. The absolute rate of transport is sensitive to disk
microphysics which remains to be explored in future studies.


title: GW150914-like Black Holes as Galactic High-Energy Sources

abstract:
  The first direct detections of gravitational waves (GWs) from black hole (BH)
mergers, GW150914, GW151226 and LVT151012, give a robust lower limit $\sim
70000$ on the number of merged, highly-spinning BHs in our Galaxy. The total
spin energy is comparable to all the kinetic energy of supernovae that ever
happened in our Galaxy. The BHs release the spin energy to relativistic jets by
accreting matter and magnetic fields from the interstellar medium (ISM). By
considering the distributions of the ISM density, BH mass and velocity, we
calculate the luminosity function of the BH jets, and find that they can
potentially accelerate TeV-PeV cosmic-ray particles in our Galaxy with total
power $\sim 10^{37\pm 3}$ erg s$^{-1}$ as PeVatrons, positron factories and/or
unidentified TeV gamma-ray sources. Additional $\sim 300$ BH jet nebulae could
be detectable by CTA (Cherenkov Telescope Array). We also argue that the
accretion from the ISM can evaporate and blow away cold material around the BH,
which has profound implications for some scenarios to predict electromagnetic
counterparts to BH mergers.


title: An $\epsilon'$ improvement from right-handed currents

abstract:
  Recent lattice QCD calculations of direct CP violation in $K_L \to \pi \pi$
decays indicate tension with the experimental results. Assuming this tension to
be real, we investigate a possible beyond-the-Standard Model explanation via
right-handed charged currents. By using chiral perturbation theory in
combination with lattice QCD results, we accurately calculate the modification
of $\epsilon'/\epsilon$ induced by right-handed charged currents and extract
values of the couplings that are necessary to explain the discrepancy, pointing
to a scale around $10^2$ TeV. We find that couplings of this size are not in
conflict with constraints from other precision experiments, but next-generation
hadronic electric dipole moment searches (such as neutron and ${}^{225}$Ra) can
falsify this scenario. We work out in detail a direct link, based on chiral
perturbation theory, between CP violation in the kaon sector and electric
dipole moments induced by right-handed currents which can be used in future
analyses of left-right symmetric models.


title: Dimensional renormalization in AdS/CFT

abstract:
  In this paper we present a dimensional renormalization scheme suitable for
holographic theories. We use the bulk physics in the supergravity limit as a
definition of the dual CFT. Similar to the perturbative quantization of a QFT,
one is free to choose a convenient renormalization scheme, and the holographic
renormalization method is only one such choice. We show how the bulk theory can
be rendered finite with a renormalization scheme that corresponds to
dimensional renormalization in the dual CFT. The method does not require any
cut-offs and does not introduce any dimensionful parameters. It delivers a
one-to-one map between bulk and boundary counterterms and leads to an exact and
unambiguous identification of field theoretical objects in terms of bulk data.
In particular, we resolve long standing issues regarding the identification of
the renormalization scale and beta functions on both sides of the AdS/CFT
correspondence. Furthermore, the method is considerably simpler than standard
holographic renormalization on a practical level when evaluating correlation
functions.


title:
IRAS 18153-1651: an H II region with a possible wind bubble blown by a
  young main-sequence B star

abstract:
  We report the results of spectroscopic observations and numerical modelling
of the H II region IRAS 18153-1651. Our study was motivated by the discovery of
an optical arc and two main-sequence stars of spectral type B1 and B3 near the
centre of IRAS 18153-1651. We interpret the arc as the edge of the wind bubble
(blown by the B1 star), whose brightness is enhanced by the interaction with a
photoevaporation flow from a nearby molecular cloud. This interpretation
implies that we deal with a unique case of a young massive star (the most
massive member of a recently formed low-mass star cluster) caught just tens of
thousands of years after its stellar wind has begun to blow a bubble into the
surrounding dense medium. Our two-dimensional, radiation-hydrodynamics
simulations of the wind bubble and the H II region around the B1 star provide a
reasonable match to observations, both in terms of morphology and absolute
brightness of the optical and mid-infrared emission, and verify the young age
of IRAS 18153-1651. Taken together our results strongly suggest that we have
revealed the first example of a wind bubble blown by a main-sequence B star.


title:
Dichroic subjettiness ratios to distinguish colour flows in boosted
  boson tagging

abstract:
  $N$-subjettiness ratios are in wide use for tagging heavy boosted objects, in
particular the ratio of 2-subjettiness to 1-subjettiness for tagging boosted
electroweak bosons. In this article we introduce a new, \emph{dichroic} ratio,
which uses different regions of a jet to determine the two subjettiness
measures, emphasising the hard substructure for the 1-subjettiness and the full
colour radiation pattern for the 2-subjettiness. Relative to existing
$N$-subjettiness ratios, the dichroic extension, combined with SoftDrop
(pre-)grooming, makes it possible to increase the ultimate signal significance
by about $25\%$ (for $2\,\text{TeV}$ jets), or to reduce non-perturbative
effects by a factor of $2{-}3$ at $50\%$ signal efficiency while maintaining
comparable background rejection. We motivate the dichroic approach through the
study of Lund diagrams, supplemented with resummed analytical calculations.


title:
Three-phase Interstellar medium in Galaxies Resolving Evolution with
  Star formation and Supernova feedback (TIGRESS): Algorithms, Fiducial model,
  and Convergence

abstract:
  We introduce TIGRESS, a novel framework for multi-physics numerical
simulations of the star-forming interstellar medium (ISM) implemented in the
Athena MHD code. The algorithms of TIGRESS are designed to spatially and
temporally resolve key physical features, including: (1) the gravitational
collapse and ongoing accretion of gas that leads to star formation in clusters,
(2) the explosions of supernovae (SNe) both near their progenitor birth sites
and from runaway OB stars, with time delays relative to star formation
determined by population synthesis, (3) explicit evolution of SN remnants prior
to the onset of cooling, which leads to the creation of the hot ISM, (4)
photoelectric heating of the warm and cold phases of the ISM that tracks the
time-dependent ambient FUV field from the young cluster population, (5)
large-scale galactic differential rotation, which leads to epicyclic motion and
shears out overdense structures, limiting large-scale gravitational collapse,
(6) accurate evolution of magnetic fields, which can be important for vertical
support of the ISM disk as well as angular momentum transport. We present tests
of the newly-implemented physics modules, and demonstrate application of
TIGRESS in a fiducial model representing the Solar neighborhood environment. We
use a resolution study to demonstrate convergence and evaluate the minimum
resolution dx required to correctly recover several ISM properties, including
the star formation rate, wind mass-loss rate, disk scale height, turbulent and
Alfvenic velocity dispersions, and volume fractions of warm and hot phases. For
the Solar neighborhood model, all these ISM properties are converged at dx <=
8pc.


title: Last Words on the Cuprates

abstract:
  Much of what I have to say in the following (not all) is contained in my
Informal History published in 2010 in the Intl Journ of Mod Phys and available
as arXiv:1011.2736 [cond-mat]. But because the literature on the subject
continues to burgeon, mostly without much if any reference to the fundamentals
that I laid out in that article, I think it is time to distribute a summary of
the conclusions I reached in that article, as well as a few newer thoughts.


title:
SDSS IV MaNGA: Deep observations of extra-planar, diffuse ionized gas
  around late-type galaxies from stacked IFU spectra

abstract:
  We have conducted a study of extra-planar diffuse ionized gas using the first
year data from the MaNGA IFU survey. We have stacked spectra from 49 edge-on,
late-type galaxies as a function of distance from the midplane of the galaxy.
With this technique we can detect the bright emission lines Halpha, Hbeta,
[OII]3726, 3729, [OIII]5007, [NII]6549, 6584, and [SII]6717, 6731 out to about
4 kpc above the midplane. With 16 galaxies we can extend this analysis out to
about 9 kpc, i.e. a distance of ~2R_e, vertically from the midplane. In the
halo, the surface brightnesses of the [OII] and Halpha emission lines are
comparable, unlike in the disk where Halpha dominates. When we split the sample
by specific star formation rate, concentration index, and stellar mass, each
subsample's emission line surface brightness profiles and ratios differ,
indicating that extra-planar gas properties can vary. The emission line surface
brightnesses of the gas around high specific star formation rate galaxies are
higher at all distances, and the line ratios are closer to ratios
characteristic of HII regions compared with low specific star formation rate
galaxies. The less concentrated and lower stellar mass samples exhibit line
ratios that are more like HII regions at larger distances than their more
concentrated and higher stellar mass counterparts. The largest difference
between different subsamples occurs when the galaxies are split by stellar
mass. We additionally infer that gas far from the midplane in more massive
galaxies has the highest temperatures and steepest radial temperature gradients
based on their [NII]/Halpha and [OII]/Halpha ratios between the disk and the
halo.


title:
Enhanced Conductivity Along Lateral Homojunction Interfaces of
  Atomically Thin Semiconductors

abstract:
  Energy band realignment at the interfaces between materials in
heterostructures can give rise to unique electronic characteristics and
non-trivial low-dimensional charge states. In a homojunction of monolayer and
multilayer MoS$_2$, the thickness-dependent band structure implies the
possibility of band realignment and a new interface charge state with
properties distinct from the isolated layers. In this report, we probe the
interface charge state using scanning photocurrent microscopy and
gate-dependent transport with source-drain bias applied along the interface.
Enhanced photoresponse observed at the interface is attributed to band bending.
The effective conductivity of a material with a monolayer-multilayer interface
of MoS$_2$ is demonstrated to be higher than that of independent monolayers or
multilayers of MoS$_2$. A classic heterostructure model is constructed to
interpret the electrical properties at the interface. Our work reveals that the
band engineering at the transition metal dichalcogenides monolayer/multilayer
interfaces can enhance the longitudinal conductance and field-effect mobility
of the composite monolayer and multilayer devices.


title: Building reverse plane partitions with rim-hook-shaped bricks

abstract:
  The generating function of reverse plane partitions of a fixed shape factors
into a product featuring the hook-lengths of this shape. This result, which was
first obtained by Stanley, can be explained bijectively using the
Hillman-Grassl correspondence between reverse plane partitions and tableaux
weighted by hook-lengths. In this extended abstract an alternative bijection
between the same families of objects is presented. This construction is best
perceived as a set of rules for building reverse plane partitions, viewed as
arrangements of stacks of cubes, using bricks in the shape of rim-hooks.


title: SU(5) Unification with TeV-scale Leptoquarks

abstract:
  It was previously noted that SU(5) unification can be achieved via the simple
addition of light scalar leptoquarks from two split $\bf10$ multiplets. We
explore the parameter space of this model in detail and find that unification
requires at least one leptoquark to have mass below $\approx16\,$TeV. We point
out that introducing splitting of the $\bf24$ allows the unification scale to
be raised beyond $10^{16}$ GeV, while a U(1)$_{PQ}$ symmetry can be imposed to
forbid dangerous proton decay mediated by the light leptoquarks. The latest
bounds from LHC searches are combined and we find that a leptoquark as light as
400 GeV is still permitted. Finally, we discuss the interesting possibility
that the leptoquarks required for unification could also be responsible for the
$2.6\sigma$ deviation observed in the ratio $R_K$ at LHCb.


title:
The pinching method for Galactic cosmic ray positrons: implications in
  the light of precision measurements

abstract:
  Two years ago, the AMS collaboration released the most precise measurement of
the cosmic ray positron flux. It confirms that pure secondary predictions fall
below the data above 10 GeV, suggesting the presence of a primary component,
e.g. annihilations of WIMPs dark matter. Most analyses have focused on the
high-energy part of the spectrum, disregarding the GeV energy region where
cosmic ray transport is harder to model and solar modulation comes into play.
Given the high quality of AMS measurements, it is timely to re-examine the
positron anomaly over the entire energy range, taking into account transport
processes so far neglected, e.g. convection or diffusive re-acceleration. We
devise a new semi-analytical method to take into account transport processes so
far neglected, but important below a few GeV. It is based on the pinching of
inverse Compton and synchrotron energy losses inside the Galactic disc. It
allows to carry out extensive scans over the cosmic ray propagation parameters,
which we strongly constrain by requiring that the secondary component does not
overshoot the AMS measurements. Only models with large diffusion coefficients
survive this test. The positron flux is a powerful and independent probe of
cosmic ray propagation, complementary to the boron-to-carbon ratio. We then
scan over WIMP mass to fit the annihilation cross section and branching ratios,
exploring both direct annihilations into standard model particles or through
light mediators. In the former case, the best fit yields a $p$-value of 0.4%
for a mass of 264 GeV, a value that does not allow to reproduce the highest
energy data points. Worse quality fits are found in the latter case. The
interpretation of the positron excess in terms of single DM species
annihilations is strongly disfavored. This conclusion is based solely on the
positron data, and no other observation needs to be invoked.


title:
3D fully convolutional networks for subcortical segmentation in MRI: A
  large-scale study

abstract:
  This study investigates a 3D and fully convolutional neural network (CNN) for
subcortical brain structure segmentation in MRI. 3D CNN architectures have been
generally avoided due to their computational and memory requirements during
inference. We address the problem via small kernels, allowing deeper
architectures. We further model both local and global context by embedding
intermediate-layer outputs in the final prediction, which encourages
consistency between features extracted at different scales and embeds
fine-grained information directly in the segmentation process. Our model is
efficiently trained end-to-end on a graphics processing unit (GPU), in a single
stage, exploiting the dense inference capabilities of fully CNNs.
  We performed comprehensive experiments over two publicly available datasets.
First, we demonstrate a state-of-the-art performance on the ISBR dataset. Then,
we report a {\em large-scale} multi-site evaluation over 1112 unregistered
subject datasets acquired from 17 different sites (ABIDE dataset), with ages
ranging from 7 to 64 years, showing that our method is robust to various
acquisition protocols, demographics and clinical factors. Our method yielded
segmentations that are highly consistent with a standard atlas-based approach,
while running in a fraction of the time needed by atlas-based methods and
avoiding registration/normalization steps. This makes it convenient for massive
multi-site neuroanatomical imaging studies. To the best of our knowledge, our
work is the first to study subcortical structure segmentation on such
large-scale and heterogeneous data.


title:
Preparation and coherent manipulation of pure quantum states of a single
  molecular ion

abstract:
  Laser cooling and trapping of atoms and atomic ions has led to numerous
advances including the observation of exotic phases of matter, development of
exquisite sensors and state-of-the-art atomic clocks. The same level of control
in molecules could also lead to profound developments such as controlled
chemical reactions and sensitive probes of fundamental theories, but the
vibrational and rotational degrees of freedom in molecules pose a formidable
challenge for controlling their quantum mechanical states. Here, we use
quantum-logic spectroscopy (QLS) for preparation and nondestructive detection
of quantum mechanical states in molecular ions. We develop a general technique
to enable optical pumping and preparation of the molecule into a pure initial
state. This allows for the observation of high-resolution spectra in a single
ion (here CaH+) and coherent phenomena such as Rabi flopping and Ramsey
fringes. The protocol requires a single, far-off resonant laser, which is not
specific to the molecule, so that many other molecular ions, including
polyatomic species, could be treated with the same methods in the same
apparatus by changing the molecular source. Combined with long interrogation
times afforded by ion traps, a broad range of molecular ions could be studied
with unprecedented control and precision, representing a critical step towards
proposed applications, such as precision molecular spectroscopy, stringent
tests of fundamental physics, quantum computing, and precision control of
molecular dynamics.


title: Twofold Symmetries of the Pure Gravity Action

abstract:
  We recast the action of pure gravity into a form that is invariant under a
twofold Lorentz symmetry. To derive this representation, we construct a general
parameterization of all theories equivalent to the Einstein-Hilbert action up
to a local field redefinition and gauge fixing. We then exploit this freedom to
eliminate all interactions except those exhibiting two sets of independently
contracted Lorentz indices. The resulting action is local, remarkably simple,
and naturally expressed in a field basis analogous to the exponential
parameterization of the nonlinear sigma model. The space of twofold Lorentz
invariant field redefinitions then generates an infinite class of equivalent
representations. By construction, all off-shell Feynman diagrams are twofold
Lorentz invariant while all on-shell tree amplitudes are automatically twofold
gauge invariant. We extend our results to curved spacetime and calculate the
analogue of the Einstein equations. While these twofold invariances are hidden
in the canonical approach of graviton perturbation theory, they are naturally
expected given the double copy relations for scattering amplitudes in gauge
theory and gravity.


title:
Paying More Attention to Attention: Improving the Performance of
  Convolutional Neural Networks via Attention Transfer

abstract:
  Attention plays a critical role in human visual experience. Furthermore, it
has recently been demonstrated that attention can also play an important role
in the context of applying artificial neural networks to a variety of tasks
from fields such as computer vision and NLP. In this work we show that, by
properly defining attention for convolutional neural networks, we can actually
use this type of information in order to significantly improve the performance
of a student CNN network by forcing it to mimic the attention maps of a
powerful teacher network. To that end, we propose several novel methods of
transferring attention, showing consistent improvement across a variety of
datasets and convolutional neural network architectures. Code and models for
our experiments are available at
https://github.com/szagoruyko/attention-transfer


title: Deep Active Learning for Dialogue Generation

abstract:
  We propose an online, end-to-end, neural generative conversational model for
open-domain dialogue. It is trained using a unique combination of offline
two-phase supervised learning and online human-in-the-loop active learning.
While most existing research proposes offline supervision or hand-crafted
reward functions for online reinforcement, we devise a novel interactive
learning mechanism based on hamming-diverse beam search for response generation
and one-character user-feedback at each step. Experiments show that our model
inherently promotes the generation of semantically relevant and interesting
responses, and can be used to train agents with customized personas, moods and
conversational styles.


title:
ManifoldOptim: An R Interface to the ROPTLIB Library for Riemannian
  Manifold Optimization

abstract:
  Manifold optimization appears in a wide variety of computational problems in
the applied sciences. In recent statistical methodologies such as sufficient
dimension reduction and regression envelopes, estimation relies on the
optimization of likelihood functions over spaces of matrices such as the
Stiefel or Grassmann manifolds. Recently, Huang, Absil, Gallivan, and Hand
(2016) have introduced the library ROPTLIB, which provides a framework and
state of the art algorithms to optimize real-valued objective functions over
commonly used matrix-valued Riemannian manifolds. This article presents
ManifoldOptim, an R package that wraps the C++ library ROPTLIB. ManifoldOptim
enables users to access functionality in ROPTLIB through R so that optimization
problems can easily be constructed, solved, and integrated into larger R codes.
Computationally intensive problems can be programmed with Rcpp and
RcppArmadillo, and otherwise accessed through R. We illustrate the practical
use of ManifoldOptim through several motivating examples involving dimension
reduction and envelope methods in regression.


title:
Hierarchical Matching and Regression with Application to Photometric
  Redshift Estimation

abstract:
  This work emphasizes that heterogeneity, diversity, discontinuity, and
discreteness in data is to be exploited in classification and regression
problems. A global a priori model may not be desirable. For data analytics in
cosmology, this is motivated by the variety of cosmological objects such as
elliptical, spiral, active, and merging galaxies at a wide range of redshifts.
Our aim is matching and similarity-based analytics that takes account of
discrete relationships in the data. The information structure of the data is
represented by a hierarchy or tree where the branch structure, rather than just
the proximity, is important. The representation is related to p-adic number
theory. The clustering or binning of the data values, related to the precision
of the measurements, has a central role in this methodology. If used for
regression, our approach is a method of cluster-wise regression, generalizing
nearest neighbour regression. Both to exemplify this analytics approach, and to
demonstrate computational benefits, we address the well-known photometric
redshift or `photo-z' problem, seeking to match Sloan Digital Sky Survey (SDSS)
spectroscopic and photometric redshifts.


title:
Towards a cognitive MAC layer: Predicting the MAC-level performance in
  Dynamic WSN using Machine learning

abstract:
  Predictable network performance is key in many low-power wireless sensor
network applications. In this paper, we use machine learning as an effective
technique for real-time characterization of the communication performance as
observed by the MAC layer. Our approach is data-driven and consists of three
steps: extensive experiments for data collection, offline modeling and
trace-driven performance evaluation. From our experiments and analysis, we find
that a neural networks prediction model shows best performance.


title:
Manifestation of the collective drift of molecules in argon according to
  their mean square displacements

abstract:
  The mean square displacement (MSD) of an argon molecule as a function of time
is studied. Its deviations from the standard asymptotic law for intermediate
times are analyzed in details. It is shown that these deviations are mainly
connected with the square-root contribution to the MSD which is proportional
the ratio of the collective part to the full self-diffusion coefficient. It is
established that the relative value of the collective contribution to the
self-diffusion coefficient of argon changes from 0.23 near the triple point up
to 0.4 at approaching the critical point. A new method for the determination of
the Maxwell relaxation time is proposed. Its temperature dependence on the
coexistence curve and one of isochors is investigated.


title:
Electron Weibel Instability in Relativistic Counter-Streaming Plasmas
  with Flow-Aligned External Magnetic Fields

abstract:
  The Weibel instability driven by two symmetric counter-streaming relativistic
electron plasmas, also referred to as current-filamentation instability, is
studied in a constant and uniform external magnetic field aligned with the
plasma flows. Both the linear and non linear stages of the instability are
investigated using analytical modeling and Particle-In-Cell (PIC) simulations.
While previous studies have already described the stabilizing effect of the
magnetic field, we show here that the saturation stage is only weakly affected.
The different mechanisms responsible for the saturation are discussed in detail
in the relativistic cold fluid framework considering a single unstable mode.
The application of an external field leads to a slighlt increase of the
saturation level for large wavelengths, while it does not affect the small
wavelengths. Multi-mode and temperature effects are then investigated. While at
large temperature the saturation level is independent of the external magnetic
field, at small but finite temperature the competition between different modes
in the presence of an external magnetic field leads to a saturation level lower
with respect to the unmagnetized case.


title:
Trident: a universal tool for generating synthetic absorption spectra
  from astrophysical simulations

abstract:
  Hydrodynamical simulations are increasingly able to accurately model physical
systems on stellar, galactic, and cosmological scales, however, the utility of
these simulations is often limited by our ability to directly compare them with
the datasets produced by observers: spectra, photometry, etc. To address this
problem, we have created Trident}, a Python-based, open-source tool for
post-processing hydrodynamical simulations to produce synthetic absorption
spectra and related data. Trident} can (i) create absorption-line spectra for
any trajectory through a simulated dataset mimicking both background quasar and
down-the-barrel configurations, (ii) reproduce the spectral characteristics of
common instruments like the Cosmic Origins Spectrograph, (iii) operate across
the ultraviolet, optical and infrared using customizable absorption line lists,
(iv) trace simulated physical structures directly to spectral features, (v)
approximate the presence of ion species absent from the simulation outputs,
(vi) generate column density maps for any ion, and (vii) provide support for
all major astrophysical hydrodynamical codes. The focus of Trident's
development is for using simulated datasets to better interpret observations of
the circumgalactic medium (CGM) and intergalactic medium (IGM), but it remains
a general tool applicable in other contexts.


title:
Multiplier algebras of complete Nevanlinna-Pick spaces: dilations,
  boundary representations and hyperrigidity

abstract:
  We study reproducing kernel Hilbert spaces on the unit ball with the complete
Nevanlinna-Pick property through the representation theory of their algebras of
multipliers. We give a complete description of the representations in terms of
the reproducing kernels. While representations always dilate to
$*$-representations of the ambient $C^*$-algebra, we show that in our setting
we automatically obtain coextensions. In fact, we show that in many cases, this
phenomenon characterizes the complete Nevanlinna-Pick property. We also deduce
operator theoretic dilation results which are in the spirit of work of Agler
and several other authors. Moreover, we identify all boundary representations,
compute the $C^*$-envelopes and determine hyperrigidity for certain analogues
of the disc algebra. Finally, we extend these results to spaces of functions on
homogeneous subvarieties of the ball.


title: FaaS: Federation-as-a-Service

abstract:
  This document is the main high-level architecture specification of the
SUNFISH cloud federation solution. Its main objective is to introduce the
concept of Federation-as-a-Service (FaaS) and the SUNFISH platform. FaaS is the
new and innovative cloud federation service proposed by the SUNFISH project.
The document defines the functionalities of FaaS, its governance and precise
objectives. With respect to these objectives, the document proposes the
high-level architecture of the SUNFISH platform: the software architecture that
permits realising a FaaS federation. More specifically, the document describes
all the components forming the platform, the offered functionalities and their
high-level interactions underlying the main FaaS functionalities. The document
concludes by outlining the main implementation strategies towards the actual
implementation of the proposed cloud federation solution.


title: A stellar over-density associated with the Small Magellanic Cloud

abstract:
  We report the discovery of a stellar over-density 8$^{\circ}$ north of the
center of the Small Magellanic Cloud (Small Magellanic Cloud Northern
Over-Density; SMCNOD) using data from the first two years of the Dark Energy
Survey (DES) and the first year of the MAGellanic SatelLITEs Survey (MagLiteS).
The SMCNOD is indistinguishable in age, metallicity and distance from the
nearby SMC stars, being primarly composed of intermediate-age stars (6 Gyr,
Z=0.001), with a small fraction of young stars (1 Gyr, Z=0.01). The SMCNOD has
an elongated shape with an ellipticity of 0.6 and a size of $\sim$ 6x2 deg. It
has an absolute magnitude of $M_V \cong$ -7.7, $r_h = 2.1$ kpc, and
$\mu_V(r<r_h)$ = 31.2 mag arcsec$^{-2}$. We estimate a stellar mass of $\sim
10^5$ $M_{\odot}$, following a Kroupa mass function. The SMCNOD was probably
removed from the SMC disk by tidal stripping, since it is located near the head
of the Magellanic Stream, and the literature indicates likely recent LMC-SMC
encounters. This scenario is supported by the lack of significant HI gas. Other
potential scenarios for the SMCNOD origin are a transient over-density within
the SMC tidal radius or a primordial SMC satellite in advanced stage of
disruption.


title:
The Exoplanet Mass-Ratio Function from the MOA-II Survey: Discovery of a
  Break and Likely Peak at a Neptune Mass

abstract:
  We report the results of the statistical analysis of planetary signals
discovered in MOA-II microlensing survey alert system events from 2007 to 2012.
We determine the survey sensitivity as a function of planet-star mass ratio,
$q$, and projected planet-star separation, $s$, in Einstein radius units. We
find that the mass ratio function is not a single power-law, but has a change
in slope at $q \sim 10^{-4}$, corresponding to $\sim 20 M_{\oplus}$ for the
median host star mass of $\sim 0.6 M_{\odot}$. We find significant planetary
signals in 23 of the 1474 alert events that are well characterized by the
MOA-II survey data alone. Data from other groups are used only to characterize
planetary signals that have been identified in the MOA data alone. The
distribution of mass ratios and separations of the planets found in our sample
are well fit by a broken power-law model of the form $dN_{\rm pl}/(d{\rm log}
q\ d{\rm log} s) = A (q/q_{\rm br})^n s^m \, {\rm dex}^{-2}$ for $q > q_{\rm
br}$ and $dN_{\rm pl}/(d{\rm log} q\ d{\rm log} s) = A (q/q_{\rm br})^p s^m \,
{\rm dex}^{-2}$ for $q < q_{\rm br}$, where $q_{\rm br}$ is the mass ratio of
the break. We also combine this analysis with the previous analyses of Gould et
al. and Cassan et al., bringing the total sample to 30 planets. This combined
analysis yields $A = 0.61^{+0.21}_{-0.16}$, $n =-0.93\pm 0.13$, $m =
0.49_{-0.49}^{+0.47}$ and $p = 0.6^{+0.5}_{-0.4}$ for $q_{\rm br}\equiv
1.7\times 10^{-4}$. The unbroken power law model is disfavored with a $p$-value
of 0.0022, which corresponds to a Bayes factor of 27 favoring the broken
power-law model. These results imply that cold Neptunes are likely to be the
most common type of planets beyond the snow line.


title:
Understanding the Impact of Precision Quantization on the Accuracy and
  Energy of Neural Networks

abstract:
  Deep neural networks are gaining in popularity as they are used to generate
state-of-the-art results for a variety of computer vision and machine learning
applications. At the same time, these networks have grown in depth and
complexity in order to solve harder problems. Given the limitations in power
budgets dedicated to these networks, the importance of low-power, low-memory
solutions has been stressed in recent years. While a large number of dedicated
hardware using different precisions has recently been proposed, there exists no
comprehensive study of different bit precisions and arithmetic in both inputs
and network parameters. In this work, we address this issue and perform a study
of different bit-precisions in neural networks (from floating-point to
fixed-point, powers of two, and binary). In our evaluation, we consider and
analyze the effect of precision scaling on both network accuracy and hardware
metrics including memory footprint, power and energy consumption, and design
area. We also investigate training-time methodologies to compensate for the
reduction in accuracy due to limited bit precision and demonstrate that in most
cases, precision scaling can deliver significant benefits in design metrics at
the cost of very modest decreases in network accuracy. In addition, we propose
that a small portion of the benefits achieved when using lower precisions can
be forfeited to increase the network size and therefore the accuracy. We
evaluate our experiments, using three well-recognized networks and datasets to
show its generality. We investigate the trade-offs and highlight the benefits
of using lower precisions in terms of energy and memory footprint.


title:
Herschel far-infrared photometry of the Swift Burst Alert Telescope
  active galactic nuclei sample of the local universe - III. Global
  star-forming properties and the lack of a connection to nuclear activity

abstract:
  We combine the Herschel Space Observatory PACS and SPIRE photometry with
archival WISE photometry to construct the spectral energy distributions (SED)
for over 300 local ($z < 0.05$), ultra-hard X-ray (14 - 195 keV) selected
active galactic nuclei (AGN) from the Swift Burst Alert Telescope (BAT) 58
month catalogue. Using a simple analytical model that combines an exponentially
cut-off powerlaw with a single temperature modified blackbody, we decompose the
SEDs into a host-galaxy and AGN component. We calculate dust masses, dust
temperatures, and star-formation rates (SFR) for our entire sample and compare
them to a stellar mass-matched sample of local non-AGN galaxies. We find AGN
host galaxies have systematically higher dust masses, dust temperatures, and
SFRs due to the higher prevalence of late-type galaxies to host an AGN, in
agreement with previous studies of the Swift/BAT AGN. We provide a scaling to
convert X-ray luminosities into 8 - 1000 $\mu$m AGN luminosities, as well as
determine the best mid-to-far IR colors for identifying AGN dominated galaxies
in the IR regime. We find that for nearly 30 per cent of our sample, the 70
$\mu$m emission contains a significant contribution from the AGN ($> 0.5$),
especially at higher luminosities ($L_{14-195\,\rm{keV}} > 10^{42.5}$ ergs
s$^{-1}$). Finally, we measure the local SFR-AGN luminosity relationship,
finding a slope of 0.18, large scatter (0.37 dex), and no evidence for an
upturn at high AGN luminosity. We conclude with a discussion on the
implications of our results within the context of galaxy evolution with and
without AGN feedback.


title: Probing Anderson Localization using the Dynamics of a Qubit

abstract:
  Anderson localization is a consequence of coherent interference of multiple
scattering events in the presence of disorder, which leads to an exponential
suppression of the transmission. The decay of the transmission is typically
probed at a given energy or frequency. Here we show that this decay affects the
dynamics of a qubit coupled to the disordered system and we express the
relaxation rate of the qubit in terms of the localization properties.
Conversely, adding static disorder to a channel coupled to a qubit will reduce
the decoherence rate of the qubit. Hence, when designing electrodes that couple
to qubits it is possible to improve their performance by adding impurities to
the channel.


title:
Polarization Signatures of Kink Instabilities in the Blazar Emission
  Region from Relativistic Magnetohydrodynamic Simulations

abstract:
  Kink instabilities are likely to occur in the current-carrying magnetized
plasma jets. Recent observations of the blazar radiation and polarization
signatures suggest that the blazar emission region may be considerably
magnetized. While the kink instability has been studied with first-principle
magnetohydrodynamic (MHD) simulations, the corresponding time-dependent
radiation and polarization signatures have not been investigated. In this
paper, we perform comprehensive polarization-dependent radiation modeling of
the kink instability in the blazar emission region based on relativistic MHD
(RMHD) simulations. We find that the kink instability may give rise to strong
flares with polarization angle (PA) swings or weak flares with polarization
fluctuations, depending on the initial magnetic topology and magnetization.
These findings are consistent with observations. Compared with the shock model,
the kink model generates polarization signatures that are in better agreement
with the general polarization observations. Therefore, we suggest that kink
instabilities may widely exist in the jet environment, and provide an efficient
way to convert the magnetic energy and produce multiwavelength flares and
polarization variations.


title:
Green's functions of electrons in group-VI dichalcogenides in a magnetic
  field

abstract:
  Closed expression for the Green's function of the stationary two-dimensional
Schrodinger equation for an electron in group-VI dichalcogenides in the
presence of a magnetic field is obtained in terms of the Whittaker functions.
The resulting Green's function operator is a~$8 \times 8$ matrix consisting of
four block-diagonal~$2\times 2$ matrices, each of them characterized by
different values of valley index and electron spin. The obtained results are
used to calculate local density of states induced by a neutral delta-like
impurity in the presence of a magnetic field within the lowest Born
approximation. The spatial electron density experiences either the Friedel-like
oscillations or an exponential decay as a function of the distance from the
impurity.

categories: cond-mat.mes-hall cond-mat.other math-ph math.MP


title: A note on the ring of invariant jet differentials

abstract:
  In this article we briefly discuss the finite generation of fiber rings of
invariant k-jets of holomorphic curves in a complex projective manifold, using
differential Galois theory.


title:
On the Identification of SM and Alamouti Coded SC-FDMA Signals: A
  Statistical-Based Approach

abstract:
  Signal identification represents the task of a receiver to identify the
signal type and its parameters, with applications to both military and
commercial communications. In this paper, we investigate the identification of
spatial multiplexing (SM) and Alamouti (AL) space-time block code (STBC) with
single carrier frequency division multiple access (SC-FDMA) signals, when the
receiver is equipped with a single antenna. We develop a discriminating feature
based on a fourth-order statistic of the received signal, as well as a constant
false alarm rate decision criterion which relies on the statistical properties
of the feature estimate. Furthermore, we present the theoretical performance
analysis of the proposed identification algorithm. The algorithm does not
require channel or noise power estimation, modulation classification, and block
synchronization. Simulation results show the validity of the proposed
algorithm, as well as a very good agreement with the theoretical analysis.


title:
Measuring the electron neutrino mass with improved sensitivity: the
  HOLMES experiment

abstract:
  HOLMES is a new experiment aiming at directly measuring the neutrino mass
with a sensitivity below 2 eV. HOLMES will perform a calorimetric measurement
of the energy released in the decay of $^{163}$Ho. The calorimetric measurement
eliminates systematic uncertainties arising from the use of external beta
sources, as in experiments with spectrometers. This measurement was proposed in
1982 by A. De Rujula and M. Lusignoli, but only recently the detector
technological progress has allowed to design a sensitive experiment. HOLMES
will deploy a large array of low temperature microcalorimeters with implanted
$^{163}$Ho nuclei. HOLMES, besides being an important step forward in the
direct neutrino mass measurement with a calorimetric approach, will also
establish the potential of this approach to extend the sensitivity down to 0.1
eV and lower. In its final configuration HOLMES will collect about $3\cdot
10^{13}$ decays with 1000 detectors characterized by an instrumental energy
resolution of the order of few eV and a time resolution of few microseconds. To
embed the $^{163}$Ho into the gold absorbers a custom mass separator ion
implanter is being developed. The detectors used for the HOLMES experiment will
be Mo/Cu bilayers TESs (Transition Edge Sensors) on SiN$_x$ membrane with gold
absorbers. Microwave multiplexed rf-SQUIDs are the best available technique to
read out large array of such detectors. An extensive R&D activity is in
progress in order to maximize the multiplexing factor while preserving the
performances of the individual detectors. The current activities are focused on
the the single detector performances optimization and on the $^{163}$Ho isotope
production and embedding. A preliminary measurement of a sub-array of $4\times
16$ detectors is planned late in 2017. In this contribution we present the
HOLMES project with its technical challenges, its status and perspectives.


title:
Identification of release sources in advection-diffusion system by
  machine learning combined with Green function inverse method

abstract:
  The identification of sources of advection-diffusion transport is based
usually on solving complex ill-posed inverse models against the available
state- variable data records. However, if there are several sources with
different locations and strengths, the data records represent mixtures rather
than the separate influences of the original sources. Importantly, the number
of these original release sources is typically unknown, which hinders
reliability of the classical inverse-model analyses. To address this challenge,
we present here a novel hybrid method for identification of the unknown number
of release sources. Our hybrid method, called HNMF, couples unsupervised
learning based on Nonnegative Matrix Factorization (NMF) and inverse-analysis
Green functions method. HNMF synergistically performs decomposition of the
recorded mixtures, finds the number of the unknown sources and uses the Green
function of advection-diffusion equation to identify their characteristics. In
the paper, we introduce the method and demonstrate that it is capable of
identifying the advection velocity and dispersivity of the medium as well as
the unknown number, locations, and properties of various sets of synthetic
release sources with different space and time dependencies, based only on the
recorded data. HNMF can be applied directly to any problem controlled by a
partial-differential parabolic equation where mixtures of an unknown number of
sources are measured at multiple locations.


title:
Expanding the Catalog: Considering the Importance of Carbon, Magnesium,
  and Neon in the Evolution of Stars and Habitable Zones

abstract:
  Building on previous work, we have expanded our catalog of evolutionary
models for stars with variable composition; here we present models for stars of
mass 0.5 - 1.2 Msol, at scaled metallicities of 0.1 - 1.5 Zsol, and specific
C/Fe, Mg/Fe, and Ne/Fe values of 0.58 - 1.72 C/Fe_sol, 0.54 - 1.84 Mg/Fe_sol
and 0.5 - 2.0 Ne/Fe_sol, respectively. We include a spread in abundance values
for carbon and magnesium based on observations of their variability in nearby
stars; we choose an arbitrary spread in neon abundance values commensurate with
the range seen in other low Z elements due to the difficult nature of obtaining
precise measurements of neon abundances in stars. As indicated by the results
of Truitt et al. (2015), it is essential that we understand how differences in
individual elemental abundances, and not just the total scaled metallicity, can
measurably impact a star's evolutionary lifetime and other physical
characteristics. In that work we found that oxygen abundances significantly
impacted the stellar evolution; carbon, magnesium, and neon are potentially
important elements to individually consider due to their relatively high (but
also variable) abundances in stars. We present 528 new stellar main sequence
models, and we calculate the time-dependent evolution of the associated
habitable zone boundaries for each based on mass, temperature, and luminosity.
We also reintroduce the 2 Gyr "Continuously Habitable Zone" as a useful tool to
help gauge the habitability potential for a given planetary system.


title:
Nonnegative Matrix Factorization for identification of unknown number of
  sources emitting delayed signals

abstract:
  Factor analysis is broadly used as a powerful unsupervised machine learning
tool for reconstruction of hidden features in recorded mixtures of signals. In
the case of a linear approximation, the mixtures can be decomposed by a variety
of model-free Blind Source Separation (BSS) algorithms. Most of the available
BSS algorithms consider an instantaneous mixing of signals, while the case when
the mixtures are linear combinations of signals with delays is less explored.
Especially difficult is the case when the number of sources of the signals with
delays is unknown and has to be determined from the data as well. To address
this problem, in this paper, we present a new method based on Nonnegative
Matrix Factorization (NMF) that is capable of identifying: (a) the unknown
number of the sources, (b) the delays and speed of propagation of the signals,
and (c) the locations of the sources. Our method can be used to decompose
records of mixtures of signals with delays emitted by an unknown number of
sources in a nondispersive medium, based only on recorded data. This is the
case, for example, when electromagnetic signals from multiple antennas are
received asynchronously; or mixtures of acoustic or seismic signals recorded by
sensors located at different positions; or when a shift in frequency is induced
by the Doppler effect. By applying our method to synthetic datasets, we
demonstrate its ability to identify the unknown number of sources as well as
the waveforms, the delays, and the strengths of the signals. Using Bayesian
analysis, we also evaluate estimation uncertainties and identify the region of
likelihood where the positions of the sources can be found.