title: Hybrid quantum computing with ancillas

abstract:
  In the quest to build a practical quantum computer, it is important to use
efficient schemes for enacting the elementary quantum operations from which
quantum computer programs are constructed. The opposing requirements of
well-protected quantum data and fast quantum operations must be balanced to
maintain the integrity of the quantum information throughout the computation.
One important approach to quantum operations is to use an extra quantum system
- an ancilla - to interact with the quantum data register. Ancillas can mediate
interactions between separated quantum registers, and by using fresh ancillas
for each quantum operation, data integrity can be preserved for longer. This
review provides an overview of the basic concepts of the gate model quantum
computer architecture, including the different possible forms of information
encodings - from base two up to continuous variables - and a more detailed
description of how the main types of ancilla-mediated quantum operations
provide efficient quantum gates.


title:
Conducting LaAlO3/SrTiO3 heterointerfaces on atomically flat substrates
  prepared by deionized-water

abstract:
  We have investigated how the recently-developed water-leaching method for
atomically-flat SrTiO3 (STO) substrates affects the transport properties of
LaAlO3 (LAO) and STO heterointerfaces. Using pulsed laser deposition at
identical growth conditions, we have synthesized epitaxial LAO thin-films on
two different STO substrates, which are prepared by water-leaching and buffered
hydrofluoric acid (BHF) etching methods. The structural, transport, and optical
properties of LAO/STO heterostructures grown on water-leached substrates show
the same high-quality as the samples grown on BHF-etched substrates. These
results indicate that the water-leaching method can be used to grow complex
oxide heterostructures with atomically well-defined heterointerfaces without
safety concerns.


title:
Polynomial collocation for handling an inaccurately known measurement
  configuration in electrical impedance tomography

abstract:
  The objective of electrical impedance tomography is to reconstruct the
internal conductivity of a physical body based on measurements of current and
potential at a finite number of electrodes attached to its boundary. Although
the conductivity is the quantity of main interest in impedance tomography, a
real-world measurement configuration includes other unknown parameters as well:
the information on the contact resistances, electrode positions and body shape
is almost always incomplete. In this work, the dependence of the electrode
measurements on all aforementioned model properties is parametrized via
polynomial collocation. The availability of such a parametrization enables
efficient simultaneous reconstruction of the conductivity and other unknowns by
a Newton-type output least squares algorithm, which is demonstrated by
two-dimensional numerical experiments based on both noisy simulated data and
experimental data from two water tanks.


title: Bit threads and holographic entanglement

abstract:
  The Ryu-Takayanagi (RT) formula relates the entanglement entropy of a region
in a holographic theory to the area of a corresponding bulk minimal surface.
Using the max flow-min cut principle, a theorem from network theory, we rewrite
the RT formula in a way that does not make reference to the minimal surface.
Instead, we invoke the notion of a "flow", defined as a divergenceless
norm-bounded vector field, or equivalently a set of Planck-thickness "bit
threads". The entanglement entropy of a boundary region is given by the maximum
flux out of it of any flow, or equivalently the maximum number of bit threads
that can emanate from it. The threads thus represent entanglement between
points on the boundary, and naturally implement the holographic principle. As
we explain, this new picture clarifies several conceptual puzzles surrounding
the RT formula. We give flow-based proofs of strong subadditivity and related
properties; unlike the ones based on minimal surfaces, these proofs correspond
in a transparent manner to the properties' information-theoretic meanings. We
also briefly discuss certain technical advantages that the flows offer over
minimal surfaces. In a mathematical appendix, we review the max flow-min cut
theorem on networks and on Riemannian manifolds, and prove in the network case
that the set of max flows varies Lipshitz continuously in the network
parameters.


title:
High order implicit time integration schemes on multiresolution adaptive
  grids for stiff PDEs

abstract:
  We consider high order, implicit Runge-Kutta schemes to solve time-dependent
stiff PDEs on dynamically adapted grids generated by multiresolution analysis
for unsteady problems disclosing localized fronts. The multiresolution finite
volume scheme yields highly compressed representations within a user-defined
accuracy tolerance, hence strong reductions of computational requirements to
solve large, coupled nonlinear systems of equations. SDIRK and RadauIIA
Runge-Kutta schemes are implemented with particular interest in those with
L-stability properties and accuracy-based time-stepping capabilities. Numerical
evidence is provided of the computational efficiency of the numerical strategy
to cope with highly unsteady problems modeling various physical scenarios with
a broad spectrum of time and space scales.


title:
A 3-photon process for producing a degenerate gas of metastable
  alkaline-earth atoms

abstract:
  We present a method for creating a quantum degenerate gas of metastable
alkaline-earth atoms. This has yet to be achieved due to inelastic collisions
that limit evaporative cooling in the metastable states. Quantum degenerate
samples prepared in the $^{1}S_{0}$ ground state can be rapidly transferred to
either the $^{3}P_{2}$ or $^{3}P_{0}$ state via a coherent 3-photon process.
Numerical integration of the density matrix evolution for the fine structure of
bosonic alkaline-earth atoms shows that transfer efficiencies of $\simeq90\%$
can be achieved with experimentally feasible laser parameters in both Sr and
Yb. Importantly, the 3-photon process can be set up such that it imparts no net
momentum to the degenerate gas during the excitation, which will allow for
studies of metastable samples outside the Lamb-Dicke regime. We discuss several
experimental challenges to successfully realizing our scheme, including the
minimization of differential AC Stark shifts between the four states connected
by the 3-photon transition.


title:
Beyond matroids: Secretary Problem and Prophet Inequality with general
  constraints

abstract:
  We study generalizations of the "Prophet Inequality" and "Secretary Problem",
where the algorithm is restricted to an arbitrary downward-closed set system.
For {0,1}-values, we give O(log n)-competitive algorithms for both problems.
This is close to the \Omega(log n / loglog n) lower bound due to Babaioff,
Immorlica, and Kleinberg. For general values, our results translate to O(log n
log r)-competitive algorithms, where r is the cardinality of the largest
feasible set. This resolves (up to the O(log r loglog n) factors) an open
question posed to us by Bobby Kleinberg.


title: An example of a Fra\"iss\'e class without a Kat\v{e}tov functor

abstract:
  We disprove a conjecture from [W. Kubi\'s, D. Ma\v{s}ulovi\'c, Kat\v{e}tov
functors, preprint, http://arxiv.org/abs/1412.1850] by showing the existence of
a Fra\"iss\'e class $\mathcal{C}$ which does not admit a Kat\v{e}tov functor.
On the other hand, we show that the automorphism group of the Fra\"iss\'e limit
of $\mathcal{C}$ is universal, as it happens in the presence of a Kat\v{e}tov
functor.


title:
Using Well-Understood Single-Objective Functions in Multiobjective
  Black-Box Optimization Test Suites

abstract:
  Several test function suites are being used for numerical benchmarking of
multiobjective optimization algorithms. While they have some desirable
properties, like well-understood Pareto sets and Pareto fronts of various
shapes, most of the currently used functions possess characteristics that are
arguably under-represented in real-world problems. They mainly stem from the
easier construction of such functions and result in improbable properties such
as separability, optima located exactly at the boundary constraints, and the
existence of variables that solely control the distance between a solution and
the Pareto front. Here, we propose an alternative way to constructing
multiobjective problems-by combining existing single-objective problems from
the literature. We describe in particular the bbob-biobj test suite with 55
bi-objective functions in continuous domain, and its extended version with 92
bi-objective functions (bbob-biobj-ext). Both test suites have been implemented
in the COCO platform for black-box optimization benchmarking. Finally, we
recommend a general procedure for creating test suites for an arbitrary number
of objectives. Besides providing the formal function definitions and presenting
their (known) properties, this paper also aims at giving the rationale behind
our approach in terms of groups of functions with similar properties, objective
space normalization, and problem instances. The latter allows us to easily
compare the performance of deterministic and stochastic solvers, which is an
often overlooked issue in benchmarking.


title:
A General World Model with Poiesis: Poppers Three Worlds updated with
  Software

abstract:
  With the famous Three Worlds of Karl Popper as template, the paper rigorously
introduces the concept of software to define the counterpart of the physical
subworld. Digesting the scientific-technical view of biology and neurology on a
high level, results in an updated Three Worlds scheme consistent with an
information technical view. Chance and mathematics complete the world model.
Some simple examples illustrate the move from Poppers view of the world with
physics, psyche and World 3, to a new extended model with physics, extended
software (which we call Poiesis), and Geist (the notion which embodies spirit,
mind and soul).


title:
Multi-symplectic structure of fully-nonlinear weakly-dispersive internal
  gravity waves

abstract:
  In this short communication we present the multi-symplectic structure for the
two-layer Serre-Green-Naghdi equations describing the evolution of large
amplitude internal gravity long waves. We consider only a two-layer
stratification with rigid bottom and lid for simplicity, generalisations to
several layers being straightforward. This multi-symplectic formulation allows
the application of various multi-symplectic integrators (such as Euler or
Preissman box schemes) that preserve exactly the multi-symplecticity at the
discrete level.

categories: physics.class-ph math.AP math.CA nlin.PS nlin.SI


title:
Fast and exact simulation of complex-valued stationary Gaussian
  processes through embedding circulant matrix

abstract:
  This paper is concerned with the study of the embedding circulant matrix
method to simulate stationary complex-valued Gaussian sequences. The method is,
in particular, shown to be well-suited to generate circularly-symmetric
stationary Gaussian processes. We provide simple conditions on the complex
co-variance function ensuring the theoretical validity of the minimal embedding
circulant matrix method. We show that these conditions are satisfied by many
examples and illustrate the algorithm. In particular, we present a simulation
study involving the circularly-symmetric fractional Brownian motion, a model
introduced in this paper.


title:
About the Heisenberg's uncertainty principle and the determination of
  effective optical indices in integrated photonics at high sub-wavelength
  regime

abstract:
  Within the Heisenberg's uncertainty principle it is explicitly discussed the
impact of these inequalities on the theory of integrated photonics at
sub-wavelength regime. More especially, the uncertainty of the effective index
values in nanophotonics at sub-wavelength regime, which is defined as the
eigenvalue of the overall opto-geometric problems in integrated photonics,
appears directly stemming from Heisenberg's uncertainty. An apt formula is
obtained allowing us to assume that the incertitude and the notion of
eigenvalue called effective optical index or propagation constant is inversely
proportional to the spatial dimensions of a given nanostructure yielding a
transfer of the fuzziness on relevant senses of eigenvalues below a specific
limit's volume.


title:
Chandra X-Ray Spectroscopy of the Focused Wind in the Cygnus X-1 System.
  II. The Nondip Spectrum in the Low/Hard State - Modulations with Orbital
  Phase

abstract:
  The accretion onto the black hole in the system HDE 226868/Cygnus X-1 is
powered by the strong line driven stellar wind of the O-type donor star. We
study the X-ray properties of the stellar wind in the hard state of Cyg X-1 as
determined with data from the Chandra High Energy Transmission Gratings. Large
density and temperature inhomogeneities are present in the wind, with a
fraction of the wind consisting of clumps of matter with higher density and
lower temperature embedded in a photoionized gas. Absorption dips observed in
the light curve are believed to be caused by these clumps. This work
concentrates on the non-dip spectra as a function of orbital phase. The spectra
show lines of H-like and He-like ions of S, Si, Na, Mg, Al and highly ionized
Fe (Fe xvii-Fe xxiv). We measure velocity shifts, column densities, and thermal
broadening of the line series. The excellent quality of these five observations
allows us to investigate the orbital phase dependence of these parameters. We
show that the absorber is located close to the black hole. Doppler shifted
lines point at a complex wind structure in this region, while emission lines
seen in some observations are from a denser medium than the absorber. The
observed line profiles are phase dependent. Their shapes vary from pure,
symmetric absorption at the superior conjunction to P Cygni profiles at the
inferior conjunction of the black hole.


title: The first stable homotopy groups of motivic spheres

abstract:
  We compute the 1-line of stable homotopy groups of motivic spheres over
fields of characteristic not two in terms of hermitian and Milnor K-groups.
This is achieved by solving questions about convergence and differentials in
the slice spectral sequence.


title: On Dirac's Conjecture

abstract:
  Let $G$ be a 2-connected graph, $l$ be the length of a longest path in $G$
and $c$ be the circumference - the length of a longest cycle in $G$. In 1952,
Dirac proved that $c>\sqrt{2l}$ and conjectured that $c\ge 2\sqrt{l}$. In this
paper we present more general sharp bounds in terms of $l$ and the length $m$
of a vine on a longest path in $G$ including Dirac's conjecture as a corollary:
if $c=m+y+2$ (generally, $c\ge m+y+2$) for some integer $y\ge 0$, then
$c\ge\sqrt{4l+(y+1)^2}$ if $m$ is odd; and $c\ge\sqrt{4l+(y+1)^2-1}$ if $m$ is
even.


title: Person Re-identification in Appearance Impaired Scenarios

abstract:
  Person re-identification is critical in surveillance applications. Current
approaches rely on appearance based features extracted from a single or
multiple shots of the target and candidate matches. These approaches are at a
disadvantage when trying to distinguish between candidates dressed in similar
colors or when targets change their clothing. In this paper we propose a
dynamics-based feature to overcome this limitation. The main idea is to capture
soft biometrics from gait and motion patterns by gathering dense short
trajectories (tracklets) which are Fisher vector encoded. To illustrate the
merits of the proposed features we introduce three new "appearance-impaired"
datasets. Our experiments on the original and the appearance impaired datasets
demonstrate the benefits of incorporating dynamics-based information with
appearance-based information to re-identification algorithms.


title: $n$-digit Benford converges to Benford

abstract:
  Using the sum invariance property of Benford random variables, we prove that
an $n$-digit Benford variable converges to a Benford variable as $n$ approaches
infinity.


title: The Mittag-Leffler Fitting of the Phillips Curve

abstract:
  In this paper, a mathematical model based on the one-parameter Mittag-Leffler
function is proposed to be used for the first time to describe the relation
between unemployment rate and inflation rate, also known as the Phillips curve.
The Phillips curve is in the literature often represented by an
exponential-like shape. On the other hand, Phillips in his fundamental paper
used a power function in the model definition. Considering that the ordinary as
well as generalised Mittag-Leffler function behaves between a purely
exponential function and a power function it is natural to implement it in the
definition of the model used to describe the relation between the data
representing the Phillips curve. For the modelling purposes the data of two
different European economies, France and Switzerland, were used and an
"out-of-sample" forecast was done to compare the performance of the
Mittag-Leffler model to the performance of the power-type and exponential-type
model. The results demonstrate that the ability of the Mittag-Leffler function
to fit data that manifest signs of stretched exponentials, oscillations or even
damped oscillations can be of use when describing economic relations and
phenomenons, such as the Phillips curve.


title: Massive charged BTZ black holes in asymptotically (a)dS spacetimes

abstract:
  Motivated by recent developments of BTZ black holes and interesting results
of massive gravity, we investigate massive BTZ black holes in the presence of
Maxwell and Born-Infeld (BI) electrodynamics. We study geometrical properties
such as type of singularity and asymptotical behavior as well as thermodynamic
structure of the solutions through canonical ensemble. We show that despite the
existence of massive term, obtained solutions are asymptotically (a)dS and have
a curvature singularity at the origin. Then, we regard varying cosmological
constant and examine the Van der Waals like behavior of the solutions in
extended phase space. In addition, we employ geometrical thermodynamic
approaches and show that using Weinhold, Ruppeiner and Quevedo metrics leads to
existence of ensemble dependency while HPEM metric yields consistent picture.
For neutral solutions, it will be shown that generalization to massive gravity
leads to the presence of non-zero temperature and heat capacity for vanishing
horizon radius. Such behavior is not observed for linearly charged solutions
while generalization to nonlinearly one recovers this property.


title: A percolation on directed graphs

abstract:
  Suppose each site independently and randomly chooses some sites around it,
and it is weakly (strongly) connected with them (if there choose each other).
What is the probability that the weak (strong) connected cluster is infinite?
We investigate a percolation model for this problem, which is a generalization
of site percolation. We give a relation between the probability of the number
of chosen sites around a site and the size of clusters. We also see the
expected number of infinite clusters, and the exponential tail decay of the
radius and the size of a cluster.


title: Statistical Analysis of I Stokes Parameter of Millisecond Pulsars

abstract:
  Using Detrended Fluctuation Analysis (DFA) and box counting method, we test
spacial correlation and fractality of Polarization Pulse Profiles (PPPs) of 24
millisecond pulsars (MSPs) which were observed in Parkes Pulsar Timing Array
(PPTA) project. DFA analysis indicates that MSPs' PPPs are persistent and the
results of box counting method confirm the fractality in the majority of PPPs.
A Kolmogorov-Smirnov test indicates that isolated MSPs have more complex PPPs
than binary ones. Then we apply our analysis on a random sample of normal
pulsars. Comparing the results of our analysis on MSPs and normal pulsars shows
that MSPs have more complex PPPs which is resulted from smaller angular
half-width of the emission cone and more peaks in MSPs PPPs. On the other hand,
high values of Hurst exponent in MSPs confirm compact emission regions in these
pulsars.


title: The influence of outflow in supercritical accretion flows

abstract:
  We solve the radiation-hydrodynamic (RHD) equations of supercritical
accretion flows in the presence of radiation force and outflow by using self
similar solutions. Compare with the pioneer works, in this paper we consider
power-law function for mass inflow rate as $ \dot{M} \propto r^{s} $. We found
that $ s = 1 $ when the radiative cooling term is included in the energy
equation. Correspondingly, the effective temperature profile with respect to
the radius was obtained as $ T_{\text{eff}} \varpropto r^{-1/2} $. In addition,
we investigated the influence of the outflow on the dynamics of the accretion
flow. We also calculated the continuum spectrum emitted from the disk surface
as well as the bolometric luminosity of the accretion flow. Furthermore, our
results show that the advection parameter, $ f $, strongly depends on mass
inflow rate.


title: Noise reduction of a Libbrecht--Hall style current driver

abstract:
  The Libbrecht--Hall circuit is a well-known, low-noise current driver for
narrow-linewidth diode lasers. An important feature of the circuit is a current
limit to protect the laser diode. As the current approaches the maximum limit,
however, the noise in the laser current increases dramatically. This paper
documents this behavior and explores simple circuit modifications to alleviate
this issue.


title: Twisted logarithmic modules of free field algebras

abstract:
  Given a non-semisimple automorphism $\varphi$ of a vertex algebra $V$, the
fields in a $\varphi$-twisted $V$-module involve the logarithm of the formal
variable, and the action of the Virasoro operator $L_0$ on such module is not
semisimple. We construct examples of such modules and realize them explicitly
as Fock spaces when $V$ is generated by free fields. Specifically, we consider
the cases of symplectic fermions (odd superbosons), free fermions, and
$\beta\gamma$-system (even superfermions). In each case, we determine the
action of the Virasoro algebra.


title:
Inferring network structure in non-normal and mixed discrete-continuous
  genomic data

abstract:
  Inferring dependence structure through undirected graphs is crucial for
uncovering the major modes of multivariate interaction among high-dimensional
genomic markers that are potentially associated with cancer. Traditionally,
conditional independence has been studied using sparse Gaussian graphical
models for continuous data and sparse Ising models for discrete data. However,
there are two clear situations when these approaches are inadequate. The first
occurs when the data are continuous but display non-normal marginal behavior
such as heavy tails or skewness, rendering an assumption of normality
inappropriate. The second occurs when a part of the data is ordinal or discrete
(e.g., presence or absence of a mutation) and the other part is continuous
(e.g., expression levels of genes or proteins). In this case, the existing
Bayesian approaches typically employ a latent variable framework for the
discrete part that precludes inferring conditional independence among the data
that are actually observed. The current article overcomes these two challenges
in a unified framework using Gaussian scale mixtures. Our framework is able to
handle continuous data that are not normal and data that are of mixed
continuous and discrete nature, while still being able to infer a sparse
conditional sign independence structure among the observed data. Extensive
performance comparison in simulations with alternative techniques and an
analysis of a real cancer genomics data set demonstrate the effectiveness of
the proposed approach.


title:
Reinforcement learning based local search for grouping problems: A case
  study on graph coloring

abstract:
  Grouping problems aim to partition a set of items into multiple mutually
disjoint subsets according to some specific criterion and constraints. Grouping
problems cover a large class of important combinatorial optimization problems
that are generally computationally difficult. In this paper, we propose a
general solution approach for grouping problems, i.e., reinforcement learning
based local search (RLS), which combines reinforcement learning techniques with
descent-based local search. The viability of the proposed approach is verified
on a well-known representative grouping problem (graph coloring) where a very
simple descent-based coloring algorithm is applied. Experimental studies on
popular DIMACS and COLOR02 benchmark graphs indicate that RLS achieves
competitive performances compared to a number of well-known coloring
algorithms.


title: Oscillating Filaments: I - Oscillation and Geometrical Fragmentation

abstract:
  We study the stability of filaments in equilibrium between gravity and
internal as well as external pressure using the grid based AMR-code RAMSES. A
homogeneous, straight cylinder below a critical line mass is marginally stable.
However, if the cylinder is bent, e.g. with a slight sinusoidal perturbation,
an otherwise stable configuration starts to oscillate, is triggered into
fragmentation and collapses. This previously unstudied behavior allows a
filament to fragment at any given scale, as long as it has slight bends. We
call this process `geometrical fragmentation'. In our realization the spacing
between the cores matches the wavelength of the sinusoidal perturbation,
whereas up to now, filaments were thought to be only fragmenting on the
characteristical scale set by the mass-to-line ratio. Using first principles,
we derive the oscillation period as well as the collapse timescale
analytically. To enable a direct comparison with observations, we study the
line-of-sight velocity for different inclinations. We show that the overall
oscillation pattern can hide the infall signature of cores.


title:
Photoinduced Magnetic Nanoprobe Excited by Azimuthally Polarized Vector
  Beam

abstract:
  The concept of magnetic nanoprobes (or magnetic nanoantennas) providing a
magnetic near-field enhancement and vanishing electric field is presented and
investigated, together with their excitation. It is established that a
particular type of cylindrical vector beams called azimuthally electric
polarized vector beams yield strong longitudinal magnetic field on the beam
axis where the electric field is ideally null. These beams with an electric
polarization vortex and cylindrical symmetry are important in generating high
magnetic to electric field contrast, i.e., large local field admittance, and in
allowing selective excitation of magnetic transitions in matter located on the
beam axis. We demonstrate that azimuthally polarized vector beam excitation of
a photoinduced magnetic nanoprobe made of a magnetically polarizable nano
cluster leads to enhanced magnetic near field with resolution beyond
diffraction limit. We introduce two figures of merit as magnetic field
enhancement and local field admittance normalized to that of a plane wave that
are useful to classify magnetic nanoprobes and their excitation. The
performance of magnetic nanoprobe and azimuthal polarized beams is quantified
in comparison to other illumination options and with several defect scenarios.


title:
High-speed ultrasound imaging in dense suspensions reveals
  impact-activated solidification due to dynamic shear jamming

abstract:
  A remarkable property of dense suspensions is that they can transform from
liquid-like at rest to solid-like under sudden impact. Previous work showed
that this impact-induced solidification involves rapidly moving jamming fronts;
however, details of this process have remained unresolved. Here we use
high-speed ultrasound imaging to probe non-invasively how the interior of a
dense suspension responds to impact. Measuring the speed of sound we
demonstrate that the solidification proceeds without a detectable increase in
packing fraction, and imaging the evolving flow field we find that the shear
intensity is maximized right at the jamming front. Taken together, this
provides direct experimental evidence for jamming by shear, rather than
densification, as driving the transformation to solid-like behavior. Based on
these findings we propose a new model to explain the anisotropy in the
propagation speed of the fronts and delineate the onset conditions for dynamic
shear jamming in suspensions.


title: The New Frontier in RAN Heterogeneity: Multi-tier Drone-Cells

abstract:
  In cellular networks, the locations of the radio access network (RAN)
elements are determined mainly based on the long-term traffic behaviour.
However, when the random and hard-to-predict spatio-temporal distribution of
the traffic (load,demand) does not fully match the fixed locations of the RAN
elements (supply), some performance degradation becomes inevitable. The concept
of multi-tier cells (heterogeneous networks, HetNets) has been introduced in 4G
networks to alleviate this mismatch. However, as the traffic distribution
deviates more and more from the long-term average, even the HetNet architecture
will have difficulty in coping up with the erratic supply-demand mismatch,
unless the RAN is grossly over-engineered (which is a financially non-viable
solution). In this article, we study the opportunistic utilization of
low-altitude unmanned aerial platforms equipped with base stations (BSs), i.e.,
drone-BSs, in 5G networks. In particular, we envisage a multi-tier drone-cell
network complementing the terrestrial HetNets. The variety of equipment, and
non-rigid placement options allow utilizing multitier drone-cell networks to
serve diversified demands. Hence, drone-cells bring the supply to where the
demand is, which sets new frontiers for the heterogeneity in 5G networks. We
investigate the advancements promised by drone-cells, and discuss the
challenges associated with their operation and management. We propose a
drone-cell management framework (DMF) benefiting from the synergy among
software defined networking (SDN), network functions virtualization (NFV), and
cloud-computing. We demonstrate DMF mechanisms via a case study, and
numerically show that it can reduce the cost of utilizing drone-cells in
multitenancy cellular networks.


title: Measurement Uncertainty for Finite Quantum Observables

abstract:
  Measurement uncertainty relations are lower bounds on the errors of any
approximate joint measurement of two or more quantum observables. The aim of
this paper is to provide methods to compute optimal bounds of this type. The
basic method is semidefinite programming, which we apply to arbitrary finite
collections of projective observables on a finite dimensional Hilbert space.
The quantification of errors is based on an arbitrary cost function, which
assigns a penalty to getting result $x$ rather than y, for any pair (x,y). This
induces a notion of optimal transport cost for a pair of probability
distributions, and we include an appendix with a short summary of optimal
transport theory as needed in our context. There are then different ways to
form an overall figure of merit from the comparison of distributions. We
consider three, which are related to different physical testing scenarios. The
most thorough test compares the transport distances between the marginals of a
joint measurement and the reference observables for every input state. Less
demanding is a test just on the states for which a "true value" is known in the
sense that the reference observable yields a definite outcome. Finally, we can
measure a deviation as a single expectation value by comparing the two
observables on the two parts of a maximally entangled state. All three error
quantities have the property that they vanish if and only if the tested
observable is equal to the reference. The theory is illustrated with some
characteristic examples.


title: Framing and localization in Chern-Simons theories with matter

abstract:
  Supersymmetric localization provides exact results that should match QFT
computations in some regularization scheme. The agreement is particularly
subtle in three dimensions where complex answers from localization procedure
sometimes arise. We investigate this problem by studying the expectation value
of the 1/6 BPS Wilson loop in planar ABJ(M) theory at three loops in
perturbation theory. We reproduce the corresponding term in the localization
result and argue that it originates entirely from a non-trivial framing of the
circular contour. Contrary to pure Chern-Simons theory, we point out that for
ABJ(M) the framing phase is a non-trivial function of the couplings and that it
potentially receives contributions from vertex-like diagrams. Finally, we
briefly discuss the intimate link between the exact framing factor and the
Bremsstrahlung function of the 1/2-BPS cusp.


title:
Proceedings 6th Workshop on Mathematically Structured Functional
  Programming

abstract:
  The sixth workshop on Mathematically Structured Functional Programming is
devoted to the derivation of functionality from structure. It is a celebration
of the direct impact of Theoretical Computer Science on programs as we write
them today. Modern programming languages, and in particular functional
languages, support the direct expression of mathematical structures, equipping
programmers with tools of remarkable power and abstraction. Where would Haskell
be without monads? Functional reactive programming without arrows?
Call-by-push-value without adjunctions? The list goes on. This workshop is a
forum for researchers who seek to reflect mathematical phenomena in data and
control.
  The sixth workshop on Mathematically Structured Functional Programming was
held on 8th April 2016 as a part of ETAPS 2016 in Eindhoven, the Netherlands.
There were five contributed talks and one invited talk.


title: Large-Scale Electron Microscopy Image Segmentation in Spark

abstract:
  The emerging field of connectomics aims to unlock the mysteries of the brain
by understanding the connectivity between neurons. To map this connectivity, we
acquire thousands of electron microscopy (EM) images with nanometer-scale
resolution. After aligning these images, the resulting dataset has the
potential to reveal the shapes of neurons and the synaptic connections between
them. However, imaging the brain of even a tiny organism like the fruit fly
yields terabytes of data. It can take years of manual effort to examine such
image volumes and trace their neuronal connections. One solution is to apply
image segmentation algorithms to help automate the tracing tasks. In this
paper, we propose a novel strategy to apply such segmentation on very large
datasets that exceed the capacity of a single machine. Our solution is robust
to potential segmentation errors which could otherwise severely compromise the
quality of the overall segmentation, for example those due to poor classifier
generalizability or anomalies in the image dataset. We implement our algorithms
in a Spark application which minimizes disk I/O, and apply them to a few large
EM datasets, revealing both their effectiveness and scalability. We hope this
work will encourage external contributions to EM segmentation by providing 1) a
flexible plugin architecture that deploys easily on different cluster
environments and 2) an in-memory representation of segmentation that could be
conducive to new advances.


title:
Large Scale Earth's Bow Shock with Northern IMF as simulated by PIC code
  in parallel with MHD model

abstract:
  In this paper, we propose a 3D kinetic model (Particle-in-Cell PIC ) for the
description of the large scale Earth's bow shock. The proposed version is
stable and does not require huge or extensive computer resources. Because PIC
simulations work with scaled plasma and field parameters, we also propose to
validate our code by comparing its results with the available MHD simulations
under same scaled Solar wind ( SW ) and ( IMF ) conditions. We report new
results from the two models. In both codes the Earth's bow shock position is
found to be ~14.8 RE along the Sun-Earth line, and ~ 29 RE on the dusk side.
Those findings are consistent with past in situ observations. Both simulations
reproduce the theoretical jump conditions at the shock. However, the PIC code
density and temperature distributions are inflated and slightly shifted sunward
when compared to the MHD results. Kinetic electron motions and reflected ions
upstream may cause this sunward shift. Species distributions in the foreshock
region are depicted within the transition of the shock (measured ~2
c/{\omega}pi for {\Theta}Bn =90o and MMS =4.7 ) and in the downstream. The size
of the foot jump in the magnetic field at the shock is measured to be (1.7
c/{\omega}pi ). In the foreshocked region, the thermal velocity is found equal
to 213 km.sec-1 at 15 RE and is equal to 63 km.sec-1at 12 RE (Magnetosheath
region). Despite the large cell size of the current version of the PIC code, it
is powerful to retain macrostructure of planets magnetospheres in very short
time, thus it can be used for a pedagogical test purposes. It is also likely
complementary with MHD to deepen our understanding of the large scale
magnetosphere


title:
Electron-hole asymmetry, Dirac fermions, and quantum magnetoresistance
  in BaMnBi2

abstract:
  We report two-dimensional quantum transport and Dirac fermions in BaMnBi2
single crystals. BaMnBi2 is a layered bad metal with highly anisotropic
conductivity and magnetic order below 290 K. Magnetotransport properties,
nonzero Berry phase, small cyclotronmass, and the first-principles band
structure calculations indicate the presence of Dirac fermions in Bi square
nets. Quantum oscillations in the Hall channel suggest the presence of both
electron and hole pockets, whereas Dirac and parabolic states coexist at the
Fermi level.


title: Dynamics of the Area Law of Entanglement Entropy

abstract:
  We study the evolution of the universal area law of entanglement entropy when
the Hamiltonian of the system undergoes a time dependent perturbation. In
particular, we derive a general formula for the time dependent first order
correction to the area law under the assumption that the field theory resides
in a vacuum state when a small time-dependent perturbation of a relevant
coupling constant is turned on. Using this formula, we carry out explicit
calculations in free field theories deformed by a time dependent mass, whereas
for a generic QFT we show that the time dependent first order correction is
governed by the spectral function defining the two-point correlation function
of the trace of the energy-momentum tensor. We also carry out holographic
calculations based on the HRT proposal and find qualitative and, in certain
cases, quantitative agreement with the field theory calculations.


title: The Internet of Things: Perspectives on Security from RFID and WSN

abstract:
  A massive current research effort focuses on combining pre-existing
'Intranets' of Things into one Internet of Things. However, this unification is
not a panacea; it will expose new attack surfaces and vectors, just as it
enables new applications. We therefore urgently need a model of security in the
Internet of Things. In this regard, we note that IoT descends directly from
pre-existing research (in embedded Internet and pervasive intelligence), so
there exist several bodies of related work: security in RFID, sensor networks,
cyber-physical systems, and so on. In this paper, we survey the existing
literature on RFID and WSN security, as a step to compiling all known attacks
and defenses relevant to the Internet of Things.


title: IR finite graviton propagators in de Sitter spacetime

abstract:
  Graviton propagator diverges in certain gauges in de Sitter spacetime. We
address this problem in this work by generalizing the infinitesimal BRST
transformations in de Sitter spacetime to finite field-dependent BRST (FFBRST)
transformations. These FFBRST transformations are symmetry of the classical
action, but do not leave path integral measure invariant for the graviton
theory in de Sitter spacetime. Due to the non-trivial Jacobian of such finite
transformation the path integral measure changes and hence FFBRST
transformation is capable of relating theories in two different gauges. We
explicitly construct FFBRST transformation which relates theory with diverging
graviton two-point function to theory with infrared (IR) finite graviton. The
FFBRST transformation thus establishes that divergence in graviton two-point
function may be only a gauge artifact.


title:
A Primal-Dual Algorithm for Link Dependent Origin Destination Matrix
  Estimation

abstract:
  Origin-Destination Matrix (ODM) estimation is a classical problem in
transport engineering aiming to recover flows from every Origin to every
Destination from measured traffic counts and a priori model information. In
addition to traffic counts, the present contribution takes advantage of probe
trajectories, whose capture is made possible by new measurement technologies.
It extends the concept of ODM to that of Link dependent ODM (LODM), keeping the
information about the flow distribution on links and containing inherently the
ODM assignment. Further, an original formulation of LODM estimation, from
traffic counts and probe trajectories is presented as an optimisation problem,
where the functional to be minimized consists of five convex functions, each
modelling a constraint or property of the transport problem: consistency with
traffic counts, consistency with sampled probe trajectories, consistency with
traffic conservation (Kirchhoff's law), similarity of flows having close
origins and destinations, positivity of traffic flows. A primal-dual algorithm
is devised to minimize the designed functional, as the corresponding objective
functions are not necessarily differentiable. A case study, on a simulated
network and traffic, validates the feasibility of the procedure and details its
benefits for the estimation of an LODM matching real-network constraints and
observations.


title: An Exponential Regulator for Rapidity Divergences

abstract:
  Finding an efficient and compelling regularization of soft and collinear
degrees of freedom at the same invariant mass scale, but separated in rapidity
is a persistent problem in high-energy factorization. In the course of a
calculation, one encounters divergences unregulated by dimensional
regularization, often called rapidity divergences. Once regulated, a general
framework exists for their renormalization, the rapidity renormalization group
(RRG), leading to fully resummed calculations of transverse momentum (to the
jet axis) sensitive quantities. We examine how this regularization can be
implemented via a multi-differential factorization of the soft-collinear
phase-space, leading to an (in principle) alternative non-perturbative
regularization of rapidity divergences. As an example, we examine the
fully-differential factorization of a color singlet's momentum spectrum in a
hadron-hadron collision at threshold. We show how this factorization acts as a
mother theory to both traditional threshold and transverse momentum
resummation, recovering the classical results for both resummations. Examining
the refactorization of the transverse momentum beam functions in the threshold
region, we show that one can directly calculate the rapidity renormalized
function, while shedding light on the structure of joint resummation. Finally,
we show how using modern bootstrap techniques, the transverse momentum spectrum
is determined by an expansion about the threshold factorization, leading to a
viable higher loop scheme for calculating the relevant anomalous dimensions for
the transverse momentum spectrum.


title: Polarization observables for millicharged particles in photon collisions

abstract:
  Particles in a hidden sector can potentially acquire a small electric charge
through their interaction with the Standard Model and can consequently be
observed as millicharged particles. We systematically compute the production of
millicharged scalar, fermion and vector boson particles in collisions of
polarized photons. The presented calculation is model independent and is based
purely on the assumptions of electromagnetic gauge invariance and unitarity.
Polarization observables are evaluated and analyzed for each spin case. We show
that the photon polarization asymmetries are a useful tool for discriminating
between the spins of the produced millicharged particles. Phenomenological
implications for searches of millicharged particles in dedicated photon-photon
collision experiments are also discussed.


title: Mass segregation in star clusters is not energy equipartition

abstract:
  Mass segregation in star clusters is often thought to indicate the onset of
energy equipartition, where the most massive stars impart kinetic energy to the
lower-mass stars and brown dwarfs/free floating planets. The predicted net
result of this is that the centrally concentrated massive stars should have
significantly lower velocities than fast-moving low-mass objects on the
periphery of the cluster. We search for energy equipartition in initially
spatially and kinematically substructured N-body simulations of star clusters
with N = 1500 stars, evolved for 100 Myr. In clusters that show significant
mass segregation we find no differences in the proper motions or radial
velocities as a function of mass. The kinetic energies of all stars decrease as
the clusters relax, but the kinetic energies of the most massive stars do not
decrease faster than those of lower-mass stars. These results suggest that
dynamical mass segregation -- which is observed in many star clusters -- is not
a signature of energy equipartition from two-body relaxation.


title: Double screening

abstract:
  Attempts to modify gravity in the infrared typically require a screening
mechanism to ensure consistency with local tests of gravity. These screening
mechanisms fit into three broad classes; we investigate theories which are
capable of exhibiting more than one type of screening. Specifically, we focus
on a simple model which exhibits both Vainshtein and kinetic screening. We
point out that due to the two characteristic length scales in the problem, the
type of screening that dominates depends on the mass of the sourcing object,
allowing for different phenomenology at different scales. We consider embedding
this double screening phenomenology in a broader cosmological scenario and show
that the simplest examples that exhibit double screening are radiatively
stable.


title: The ASAS-SN Bright Supernova Catalog $-$ I. 2013$-$2014

abstract:
  We present basic statistics for all supernovae discovered by the All-Sky
Automated Survey for SuperNovae (ASAS-SN) during its first year-and-a-half of
operations, spanning 2013 and 2014. We also present the same information for
all other bright ($m_V\leq17$), spectroscopically confirmed supernovae
discovered from 2014 May 1 through the end of 2014, providing a comparison to
the ASAS-SN sample starting from the point where ASAS-SN became operational in
both hemispheres. In addition, we present collected redshifts and near-UV
through IR magnitudes, where available, for all host galaxies of the bright
supernovae in both samples. This work represents a comprehensive catalog of
bright supernovae and their hosts from multiple professional and amateur
sources, allowing for population studies that were not previously possible
because the all-sky emphasis of ASAS-SN redresses many previously existing
biases. In particular, ASAS-SN systematically finds bright supernovae closer to
the centers of host galaxies than either other professional surveys or
amateurs, a remarkable result given ASAS-SN's poorer angular resolution. This
is the first of a series of yearly papers on bright supernovae and their hosts
that will be released by the ASAS-SN team.


title:
Evidence for Variable, Correlated X-ray and Optical/IR Extinction toward
  the Nearby, Pre-main Sequence Binary TWA 30

abstract:
  We present contemporaneous XMM-Newton X-ray and ground-based optical/near-IR
spectroscopic observations of the nearby ($D \approx 42$ pc), low-mass (mid-M)
binary system TWA 30A and 30B. The components of this wide (separation
$\sim$3400 AU) binary are notable for their nearly edge-on disk viewing
geometries, high levels of variability, and evidence for collimated stellar
outflows. We obtained XMM-Newton X-ray observations of TWA 30A and 30B in 2011
June and July, accompanied (respectively) by IRTF SpeX (near-IR) and VLT
XSHOOTER (visible/near-IR) spectroscopy obtained within $\sim$20 hours of the
X-ray observations. TWA 30A was detected in both XMM-Newton observations at
relatively faint intrinsic X-ray luminosities ($L_{X}$$\sim$$8\times10^{27}$
$erg$ $s^{-1}$) compared to stars of similar mass and age . The intrinsic
(0.15-2.0 keV) X-ray luminosities measured in 2011 had decreased by a factor
20-100 relative to a 1990 (ROSAT) X-ray detection. TWA 30B was not detected,
and we infer an upper limit of ($L_{X}$ $\lesssim$ 3.0 $\times$ $10^{27}$ erg
s$^{-1}$). We measured a large change in visual extinction toward TWA 30A (from
$A_V \approx 14.9$ to $A_V \approx 4.7$) between the two 2011 observing epochs,
and we find evidence for a corresponding significant decrease in X-ray
absorbing column ($N_H$). The apparent correlated change in $A_V$ and $N_H$ is
suggestive of variable obscuration of the stellar photosphere by disk material
composed of both gas and dust. However, in both observations, the inferred
$N_{H}$ to $A_{V}$ ratio is lower than that typical of the ISM, suggesting that
the disk is either depleted of gas or is deficient in metals in the gas phase.


title:
The TRENDS High-Contrast Imaging Survey. VI. Discovery of a Mass, Age,
  and Metallicity Benchmark Brown Dwarf

abstract:
  The mass and age of substellar objects are degenerate parameters leaving the
evolutionary state of brown dwarfs ambiguous without additional information.
Theoretical models are normally used to help distinguish between old, massive
brown dwarfs and young, low mass brown dwarfs but these models have yet to be
properly calibrated. We have carried out an infrared high-contrast imaging
program with the goal of detecting substellar objects as companions to nearby
stars to help break degeneracies in inferred physical properties such as mass,
age, and composition. Rather than using imaging observations alone, our targets
are pre-selected based on the existence of dynamical accelerations informed
from years of stellar radial velocity (RV) measurements. In this paper, we
present the discovery of a rare benchmark brown dwarf orbiting the nearby
($d=18.69\pm0.19$ pc), solar-type (G9V) star HD 4747 ([Fe/H]=$-0.22\pm0.04$)
with a projected separation of only $\rho=11.3\pm0.2$ AU ($\theta \approx$
0.6"). Precise Doppler measurements taken over 18 years reveal the companion's
orbit and allow us to place strong constraints on its mass using dynamics ($m
\sin(i) = 55.3\pm1.9M_J$). Relative photometry ($\Delta K_s=9.05\pm0.14$,
$M_{K_s}=13.00\pm0.14$, $K_s - L' = 1.34\pm0.46$) indicates that HD 4747 B is
most-likely a late-type L-dwarf and, if near the L/T transition, an intriguing
source for studying cloud physics, variability, and polarization. We estimate a
model-dependent mass of $m=72^{+3}_{-13}M_J$ for an age of $3.3^{+2.3}_{-1.9}$
Gyr based on gyrochronology. Combining astrometric measurements with RV data,
we calculate the companion dynamical mass ($m=60.2\pm3.3M_J$) and orbit
($e=0.740\pm0.002$) directly. As a new mass, age, and metallicity benchmark, HD
4747 B will serve as a laboratory for precision astrophysics to test
theoretical models that describe the emergent radiation of brown dwarfs.


title:
Feedback Control of Two-mode Output Entanglement and Steering in Cavity
  Optomechanics

abstract:
  We show that the closed-loop control obtained by feeding back the derivative
of the signal from the homodyne measurement of one mode of the light exiting a
two-mode optical cavity interacting with a mechanical resonator permits to
control and increase optical output entanglement. In particular, the proposed
feedback-enhanced setup allows to achieve a fidelity of coherent state
teleportation greater than the threshold value of 2/3 for secure teleportation,
and two-way steering between the two cavity's output modes down the line in
presence of loss, which otherwise would not be possible without feedback


title: Revisiting Summarization Evaluation for Scientific Articles

abstract:
  Evaluation of text summarization approaches have been mostly based on metrics
that measure similarities of system generated summaries with a set of human
written gold-standard summaries. The most widely used metric in summarization
evaluation has been the ROUGE family. ROUGE solely relies on lexical overlaps
between the terms and phrases in the sentences; therefore, in cases of
terminology variations and paraphrasing, ROUGE is not as effective. Scientific
article summarization is one such case that is different from general domain
summarization (e.g. newswire data). We provide an extensive analysis of ROUGE's
effectiveness as an evaluation metric for scientific summarization; we show
that, contrary to the common belief, ROUGE is not much reliable in evaluating
scientific summaries. We furthermore show how different variants of ROUGE
result in very different correlations with the manual Pyramid scores. Finally,
we propose an alternative metric for summarization evaluation which is based on
the content relevance between a system generated summary and the corresponding
human written summaries. We call our metric SERA (Summarization Evaluation by
Relevance Analysis). Unlike ROUGE, SERA consistently achieves high correlations
with manual scores which shows its effectiveness in evaluation of scientific
article summarization.


title:
The Ultraviolet and Infrared Star Formation Rates of Compact Group
  Galaxies: An Expanded Sample

abstract:
  Compact groups of galaxies provide insight into the role of low-mass, dense
environments in galaxy evolution because the low velocity dispersions and close
proximity of galaxy members result in frequent interactions that take place
over extended timescales. We expand the census of star formation in compact
group galaxies by \citet{tzanavaris10} and collaborators with Swift UVOT,
Spitzer IRAC and MIPS 24 \micron\ photometry of a sample of 183 galaxies in 46
compact groups. After correcting luminosities for the contribution from old
stellar populations, we estimate the dust-unobscured star formation rate
(SFR$_{\mathrm{UV}}$) using the UVOT uvw2photometry. Similarly, we use the MIPS
24 \micron\ photometry to estimate the component of the SFR that is obscured by
dust (SFR$_{\mathrm{IR}}$). We find that galaxies which are MIR-active
(MIR-"red"), also have bluer UV colours, higher specific star formation rates,
and tend to lie in H~{\sc i}-rich groups, while galaxies that are MIR-inactive
(MIR-"blue") have redder UV colours, lower specific star formation rates, and
tend to lie in H~{\sc i}-poor groups. We find the SFRs to be continuously
distributed with a peak at about 1 M$_{\odot}$ yr$^{-1}$, indicating this might
be the most common value in compact groups. In contrast, the specific star
formation rate distribution is bimodal, and there is a clear distinction
between star-forming and quiescent galaxies. Overall, our results suggest that
the specific star formation rate is the best tracer of gas depletion and galaxy
evolution in compact groups.


title: Averaging on $n$-dimensional rectangles

abstract:
  In this work we investigate families of translation invariant differentiation
bases $B$ of rectangles in $R^n$, for which $L\log^{n-1}L(R^n)$ is the largest
Orlicz space that $B$ differentiates. In particular, we improve on techniques
developed by A.~Stokolos 1988 and 2008.


title:
Lab notebooks as scientific communication: investigating development
  from undergraduate courses to graduate research

abstract:
  In experimental physics, lab notebooks play an essential role in the research
process. For all of the ubiquity of lab notebooks, little formal attention has
been paid to addressing what is considered `best practice' for scientific
documentation and how researchers come to learn these practices in experimental
physics. Using interviews with practicing researchers, namely physics graduate
students, we explore the different experiences researchers had in learning how
to effectively use a notebook for scientific documentation. We find that very
few of those interviewed thought that their undergraduate lab classes
successfully taught them the benefit of maintaining a lab notebook. Most
described training in lab notebook use as either ineffective or outright
missing from their undergraduate lab course experience. Furthermore, a large
majority of those interviewed explained that they did not receive any formal
training in maintaining a lab notebook during their graduate school experience
and received little to no feedback from their advisors on these records. Many
of the interviewees describe learning the purpose of, and how to maintain,
these kinds of lab records only after having a period of trial and error,
having already started doing research in their graduate program. Despite the
central role of scientific documentation in the research enterprise, these
physics graduate students did not gain skills in documentation through formal
instruction, but rather through informal hands-on practice.


title:
Exponential Splitting for Nonautonomous Linear Discrete-Time Systems in
  Banach Spaces

abstract:
  In this paper we consider some concepts of exponential splitting for
nonautonomous linear discrete-time systems. These concepts are generalizations
of some well-known concepts of (uniform and nonuniform) exponential
dichotomies. Connections between these concepts are presented and some
illustrating examples prove that these are distinct.


title: Constructing black hole entropy from gravitational collapse

abstract:
  Based on a recent proposal for the gravitational entropy of free
gravitational fields, we investigate the thermodynamic properties of black hole
formation through gravitational collapse in the framework of the semitetrad
1+1+2 covariant formalism. In the simplest case of an Oppenheimer-Snyder-Datt
collapse we prove that the change in gravitational entropy outside a collapsing
body is related to the variation of the surface area of the body itself, even
before the formation of horizons. As a result, we are able to relate the
Bekenstein-Hawking entropy of the black hole endstate to the variation of the
vacuum gravitational entropy outside the collapsing body.


title: Numerical multi-loop integrals and applications

abstract:
  Higher-order radiative corrections play an important role in precision
studies of the electroweak and Higgs sector, as well as for the detailed
understanding of large backgrounds to new physics searches. For corrections
beyond the one-loop level and involving many independent mass and momentum
scales, it is in general not possible to find analytic results, so that one
needs to resort to numerical methods instead. This article presents an overview
over a variety of numerical loop integration techniques, highlighting their
range of applicability, suitability for automatization, and numerical precision
and stability.
  In a second part of this article, the application of numerical loop
integration methods in the area of electroweak precision tests is illustrated.
Numerical methods were essential for obtaining full two-loop predictions for
the most important precision observables within the Standard Model. The
theoretical foundations for these corrections will be described in some detail,
including aspects of the renormalization, resummation of leading loop
contributions, and the evaluation of the theory uncertainty from missing higher
orders.


title: Modular Anomalies in (2+1) and (3+1)-D Edge Theories

abstract:
  The classification of topological phases of matter in the presence of
interactions is an area of intense interest. One possible means of
classification is via studying the partition function under modular transforms,
as the presence of an anomalous phase arising in the edge theory of a
D-dimensional system under modular transformation, or modular anomaly, signals
the presence of a (D+1)-D non-trivial bulk. In this work, we discuss the
modular transformations of conformal field theories along a (2+1)-D and a
(3+1)-D edge. Using both analytical and numerical methods, we show that chiral
complex free fermions in (2+1)-D and (3+1)-D are modular invariant. However, we
show in (3+1)-D that when the edge theory is coupled to a background U(1) gauge
field this results in the presence of a modular anomaly that is the
manifestation of a quantum Hall effect in a (4+1)-D bulk. Using the modular
anomaly, we find that the edge theory of (4+1)-D insulator with spacetime
inversion symmetry(P*T) and fermion number parity symmetry for each spin
becomes modular invariant when 8 copies of the edges exist.


title:
Generating photon pairs from a silicon microring resonator using an
  electronic step recovery diode for pump pulse generation

abstract:
  Generation of photon pairs from compact, manufacturable and inexpensive
silicon (Si) photonic devices at room temperature may help develop practical
applications of quantum photonics. An important characteristic of photon-pair
generation is the two-photon joint spectral intensity (JSI), which describes
the frequency correlations of the photon pair. In particular, heralded
single-photon generation requires uncorrelated photons, rather than the highly
anti-correlated photons conventionally obtained under continuous-wave (CW)
pumping. Recent attempts to achieve such a factorizable JSI have used short
optical pulses from mode-locked lasers, which are much more expensive and
bigger table-top or rack-sized instruments compared to the Si microchip pair
generator, dominate the cost and inhibit the miniaturization of the source.
Here, we generate photon pairs from a Si microring resonator by using an
electronic step-recovery diode to drive an electro-optic modulator which carves
the pump light from a CW optical diode into pulses of the appropriate width,
thus potentially eliminating the need for optical mode-locked lasers.


title: Structure from Motion on a Sphere

abstract:
  We describe a special case of structure from motion where the camera rotates
on a sphere. The camera's optical axis lies perpendicular to the sphere's
surface. In this case, the camera's pose is minimally represented by three
rotation parameters. From analysis of the epipolar geometry we derive a novel
and efficient solution for the essential matrix relating two images, requiring
only three point correspondences in the minimal case. We apply this solver in a
structure-from-motion pipeline that aggregates pairwise relations by rotation
averaging followed by bundle adjustment with an inverse depth parameterization.
Our methods enable scene modeling with an outward-facing camera and object
scanning with an inward-facing camera.


title: Multiband Effects and the Bose-Hubbard Model in One-Dimensional Lattices

abstract:
  We study phase diagrams of one-dimensional bosons with contact interactions
in the presence of a lattice. We use the worm algorithm in continuous space and
focus on the incommensurate superfluid Mott-insulator transition. Our results
are compared to those from the one-band Bose-Hubbard model. When Wannier states
are used to determine the Bose-Hubbard model parameters, the comparison unveils
an apparent breakdown of the one-band description for strong interactions, even
for the Mott-insulating state with an average of one particle per site ($n=1$)
in deep lattices. We introduce an inverse confined scattering analysis to
obtain the ratio $U/J$, with which the Bose-Hubbard model provides correct
results for strong interactions, deep lattices, and $n=1$.


title:
Explicit Salem sets and applications to metrical Diophantine
  approximation

abstract:
  Let $Q$ be an infinite subset of $\mathbb{Z}$, let $\Psi: \mathbb{Z}
\rightarrow [0,\infty)$ be positive on $Q$, and let $\theta \in \mathbb{R}$.
Define $$ E(Q,\Psi,\theta) = \{ x \in \mathbb{R} : \| q x - \theta \| \leq
\Psi(q) \text{ for infinitely many $q \in Q$} \}. $$ We prove a lower bound on
the Fourier dimension of $E(Q,\Psi,\theta)$. This generalizes theorems of
Kaufman and Bluhm and yields new explicit examples of Salem sets. We give
applications to metrical Diophantine approximation, including determining the
Hausdorff dimension of $E(Q,\Psi,\theta)$ in new cases. We also prove a
higher-dimensional analog of our result.


title: Stabilizing membrane domains antagonizes n-alcohol anesthesia

abstract:
  Diverse molecules induce general anesthesia with potency strongly correlated
both with their hydrophobicity and their effects on certain ion channels. We
recently observed that several n-alcohol anesthetics inhibit heterogeneity in
plasma membrane derived vesicles by lowering the critical temperature ($T_c$)
for phase separation. Here we exploit conditions that stabilize membrane
heterogeneity to further test the correlation between the anesthetic potency of
n-alcohols and effects on $T_c$. First we show that hexadecanol acts oppositely
to n-alcohol anesthetics on membrane mixing and antagonizes ethanol induced
anesthesia in a tadpole behavioral assay. Second, we show that two previously
described `intoxication reversers' raise $T_c$ and counter ethanol's effects in
vesicles, mimicking the findings of previous electrophysiological and
behavioral measurements. Third, we find that hydrostatic pressure, long known
to reverse anesthesia, also raises $T_c$ in vesicles with a magnitude that
counters the effect of butanol at relevant concentrations and pressures. Taken
together, these results demonstrate that $\Delta T_c$ predicts anesthetic
potency for n-alcohols better than hydrophobicity in a range of contexts,
supporting a mechanistic role for membrane heterogeneity in general anesthesia.

categories: physics.bio-ph cond-mat.soft q-bio.CB q-bio.NC


title:
Monsters in the Dark: Predictions for Luminous Galaxies in the Early
  Universe from the BlueTides Simulation

abstract:
  Using deep Hubble and Spitzer observations Oesch et al. (2016) have
identified a bright ($M_{\rm UV}\approx -22$) star forming galaxy candidate at
$z \approx 11$. The presence of GN-$z11$ implies a number density $\sim
10^{-6}\,{\rm Mpc^{-3}}$, roughly an order of magnitude higher than the
expected value based on extrapolations from lower redshift. Using the
unprecedented volume and high resolution of the BlueTides cosmological
hydrodynamical simulation, we study the population of luminous rare objects at
$z > 10$. The luminosity function in BlueTides implies an enhanced number of
massive galaxies, consistent with the observation of GN-$z11$. We find about 30
galaxies at $M_{\rm UV}\approx -22$ at $z = 11$ in the BlueTides volume,
including a few objects about 1.5 magnitudes brighter. The probability of
observing GN-$z11$ in the volume probed by Oesch et al. (2016) is $\sim 13$ per
cent. The predicted properties of the rare bright galaxies at $z = 11$ in
BlueTides closely match those inferred from the observations of GN-$z11$.
BlueTides predicts a negligible contribution from faint AGN in the observed
SED. The enormous increase in volume surveyed by WFIRST will provide
observations of $\sim1000$ galaxies with $M_{\rm UV} < -22$ beyond $z = 11$ out
to $z = 13.5$.


title:
Detection of extragalactic CF+ toward PKS1830-211 -- Chemical
  differentiation in the absorbing gas

abstract:
  We report the first extragalactic detection of CF+, the fluoromethylidynium
ion, in the z=0.89 absorber toward PKS1830-211. We estimate an abundance of
~3E-10 relative to H2 and that ~1% of fluorine is captured in CF+. The
absorption line profile of CF+ is found to be markedly different from that of
other species observed within the same tuning, and is notably anti-correlated
with CH3OH. On the other hand, the CF+ profile resembles that of [C I]. Our
results are consistent with expected fluorine chemistry and point to chemical
differentiation in the column of absorbing gas.


title:
On the H\"older regularity for the fractional Schr\"odinger equation and
  its improvement for radial data

abstract:
  We consider the linear, time-independent fractional Schr\"odinger equation $$
  (-\Delta)^s \psi+V\psi=f. $$ We are interested in the local H\"older
exponents of distributional solutions $\psi$, assuming local $L^p$
integrability of the functions $V$ and $f$. By standard arguments, we obtain
the formula $2s-N/p$ for the local H\"older exponent of $\psi$ where we take
some extra care regarding endpoint cases. For our main result, we assume that
$V$ and $f$ (but not necessarily $\psi$) are radial functions, a situation
which is commonplace in applications. We find that the regularity theory
"becomes one-dimensional" in the sense that the H\"older exponent improves from
$2s-N/p$ to $2s-1/p$ away from the origin. Similar results hold for
$\nabla\psi$ as well.


title:
Transfer functions and local spectral uniqueness for Sturm-Liouville
  operators, canonical systems and strings

abstract:
  It is shown that transfer functions, which play a crucial role in M.G.
Krein's study of inverse spectral problems, are a proper tool to formulate
local spectral uniqueness conditions.


title: Understanding and Overcoming Biases in Customer Reviews

abstract:
  Our paper contributes to the literature recommending approaches to make
online reviews more credible and representative. We analyze data from four
diverse major online retailers and find that verified customers who are
prompted (by an email) to write a review, submit, on average, up to 0.5 star
higher ratings than self-motivated web reviewers. Moreover, these
email-prompted reviews remain stable over time, whereas web reviews exhibit a
downward trend. This finding provides support for the existence of social
influence and selection biases during the submission of a web review, when
social signals are being displayed. In contrast, no information about the
current state of the reviews is displayed in the email promptings. Moreover, we
find that when a retailer decides to start sending email promptings, the
existing population of web reviewers is unaffected both in their volume as well
as the characteristics of their submitted reviews. We explore how our combined
findings can suggest ways to mitigate various biases that govern online review
submissions and help practitioners provide more credible, representative and
higher ratings to their customers.


title: Supersymmetric quantum mechanics of the flux tube

abstract:
  The Operator Product Expansion approach to scattering amplitudes in maximally
supersymmetric gauge theory operates in terms of pentagon transitions for
excitations propagating on a color flux tube. These obey a set of axioms which
allow one to determine them to all orders in 't Hooft coupling and confront
against explicit calculations. One of the simplifying features of the formalism
is the factorizability of multiparticle transitions in terms of single-particle
ones. In this paper we extend an earlier consideration of a sector populated by
one kind of excitations to the case of a system with fermionic as well as
bosonic degrees of freedom to address the origin of the factorization. While
the purely bosonic case was analyzed within an integrable noncompact open-spin
chain model, the current case is solved in the framework of a supersymmetric
sl(2|1) magnet. We find the eigenfunctions for the multiparticle system making
use of the R-matrix approach. Constructing resulting pentagon transitions, we
prove their factorized form. The discussion corresponds to leading order of
perturbation theory.


title: Estimating the interaction graph of stochastic neural dynamics

abstract:
  In this paper we address the question of statistical model selection for a
class of stochastic models of biological neural nets. Models in this class are
systems of interacting chains with memory of variable length. Each chain
describes the activity of a single neuron, indicating whether it spikes or not
at a given time. The spiking probability of a given neuron depends on the time
evolution of its presynaptic neurons since its last spike time. When a neuron
spikes, its potential is reset to a resting level and postsynaptic current
pulses are generated, modifying the membrane potential of all its postsynaptic
neurons. The relationship between a neuron and its pre- and postsynaptic
neurons defines an oriented graph, the interaction graph of the model. The goal
of this paper is to estimate this graph based on the observation of the spike
activity of a finite set of neurons over a finite time. We provide explicit
exponential upper bounds for the probabilities of under- and overestimating the
interaction graph restricted to the observed set and obtain the strong
consistency of the estimator. Our result does not require stationarity nor
uniqueness of the invariant measure of the process.


title:
Probing the Electronic States in Black Phosphorus Vertical
  Heterostructures

abstract:
  Atomically thin black phosphorus (BP) is a promising two-dimensional material
for fabricating electronic and optoelectronic nano-devices with high mobility
and tunable bandgap structures. However, the charge-carrier mobility in
few-layer phosphorene (monolayer BP) is mainly limited by the presence of
impurity and disorders. In this study, we demonstrate that vertical BP
heterostructure devices offer great advantages in probing the electron states
of monolayer and few-layer phosphorene at temperatures down to 2 K through
capacitance spectroscopy. Electronic states in the conduction and valence bands
of phosphorene are accessible over a wide range of temperature and frequency.
Exponential band tails have been determined to be related to disorders. Unusual
phenomena such as the large temperature-dependence of the electron state
population in few-layer phosphorene have been observed and systematically
studied. By combining the first-principles calculation, we identified that the
thermal excitation of charge trap states and oxidation-induced defect states
were the main reasons for this large temperature dependence of the electron
state population and degradation of the on-off ratio in phosphorene
field-effect transistors.


title:
Opinion dynamics over complex networks: kinetic modeling and numerical
  methods

abstract:
  In this paper we consider the modeling of opinion dynamics over time
dependent large scale networks. A kinetic description of the agents'
distribution over the evolving network is considered which combines an opinion
update based on binary interactions between agents with a dynamic creation and
removal process of new connections. The number of connections of each agent
influences the spreading of opinions in the network but also the way
connections are created is influenced by the agents' opinion. The evolution of
the network of connections is studied by showing that its asymptotic behavior
is consistent both with Poisson distributions and truncated power-laws. In
order to study the large time behavior of the opinion dynamics a mean field
description is derived which allows to compute exact stationary solutions in
some simplified situations. Numerical methods which are capable to describe
correctly the large time behavior of the system are also introduced and
discussed. Finally, several numerical examples showing the influence of the
agents' number of connections in the opinion dynamics are reported.


title:
The role of the short range magnetic correlations on the gap opening of
  the topological Kondo insulators

abstract:
  In this work we investigate the effects of the short range magnetic
correlations on the gap opening of the topological Kondo insulators. We
consider an additional narrow band to the otherwise completely localized
f-electrons, by adding a term to the periodic Anderson model which allows a
small hopping of the localized electrons between neighboring sites of the
lattice. This new model is adequate to study a novel class of intermetallic 4f
and 5f orbitals materials: the Kondo topological insulators, whose paradigmatic
material is the compound SmB6.
  For simplicity, we consider a version of the periodic Anderson model on a two
dimensional square lattice. The starting point of the model is the 4f-Ce ions
orbitals, with J=5/2 multiplet in the presence of spin-orbit coupling. We
present results of the correlation functions and we show that the short range
antiferromagnetic correlations favors the formation of magnetic moments on the
atoms, and at the same time the existence of these moments opens the
possibility of the spin-flip scattering by the conduction electrons, generating
the Kondo effect, which contribute to the opening of a gap in the density of
states of the system. We also calculate the phase diagram which shows that, as
we vary the Ef level position from the empty regime to the Kondo regime, the
system develops several phases: metallic, band insulator and Kondo topological
insulator. The band structure calculated shows that the model develops a strong
topological insulator.


title: Elliptic stable envelopes

abstract:
  We construct stable envelopes in equivariant elliptic cohomology of Nakajima
quiver varieties. In particular, this gives an elliptic generalization of the
results of arXiv:1211.1287. We apply them to the computation of the monodromy
of $q$-difference equations arising the enumerative K-theory of rational curves
in Nakajima varieties, including the quantum Knizhnik-Zamolodchikov equations.


title: Local sparsity and recovery of fusion frames structured signals

abstract:
  The problem of recovering signals of high complexity from low quality sensing
devices is analyzed via a combination of tools from signal processing and
harmonic analysis. By using the rich structure offered by the recent
development in fusion frames, we introduce a compressed sensing framework in
which we split the dense information into sub-channel or local pieces and then
fuse the local estimations. Each piece of information is measured by
potentially low quality sensors, modeled by linear matrices and recovered via
compressed sensing -- when necessary. Finally, by a fusion process within the
fusion frames, we are able to recover accurately the original signal.
  Using our new method, we show, and illustrate on simple numerical examples,
that it is possible, and sometimes necessary, to split a signal via local
projections and / or filtering for accurate, stable, and robust estimation. In
particular, we show that by increasing the size of the fusion frame, a certain
robustness to noise can also be achieved. While the computational complexity
remains relatively low, we achieve stronger recovery performance compared to
usual single-device compressed sensing systems.


title: Cross-lingual Models of Word Embeddings: An Empirical Comparison

abstract:
  Despite interest in using cross-lingual knowledge to learn word embeddings
for various tasks, a systematic comparison of the possible approaches is
lacking in the literature. We perform an extensive evaluation of four popular
approaches of inducing cross-lingual embeddings, each requiring a different
form of supervision, on four typographically different language pairs. Our
evaluation setup spans four different tasks, including intrinsic evaluation on
mono-lingual and cross-lingual similarity, and extrinsic evaluation on
downstream semantic and syntactic applications. We show that models which
require expensive cross-lingual knowledge almost always perform better, but
cheaply supervised models often prove competitive on certain tasks.


title:
The dense gas in the largest molecular complexes of the Antennae: HCN
  and HCO+ observations of NGC 4038/39 using ALMA

abstract:
  We present observations of the dense molecular gas tracers HCN, HNC, and HCO+
in the J=1-0 transition using ALMA. We supplement our datasets with previous
observations of CO J=1-0, which traces the total molecular gas content. We
separate the Antennae into 7 bright regions in which we detect emission from
all three molecules, including the nuclei of NGC 4038 and NGC 4039, 5 super
giant molecular complexes in the overlap region and 2 additional bright clouds.
We find that the ratio of L(HCN)/L(CO), which traces the dense molecular gas
fraction, is greater in the two nuclei (L(HCN)/L(CO) ~ 0.07 - 0.08) than in the
overlap region (L(HCN)/L(CO) <0.05). We attribute this to an increase in
pressure due to the stellar potential within the nuclei, similar to what has
been seen previously in the Milky Way and nearby spiral galaxies. Furthermore,
the ratio of L(HNC)/L(HCN) ~ 0.3-0.4 does not vary by more than a factor of 1.5
between regions. By comparing our measured ratios to PDR models including
mechanical heating, we find that the ratio of L(HNC)/L(HCN) is consistent with
mechanical heating contributing >= 5% - 10% of the PDR surface heating to the
total heating budget. Finally, the ratio of L(HCN)/L(HCO+) varies from ~1 in
the nucleus of NGC 4038 down to ~0.5 in the overlap region. The lower ratio in
the overlap region may be due to an increase in the cosmic ray rate from the
increased supernova rate within this region.


title:
Leaving Some Stones Unturned: Dynamic Feature Prioritization for
  Activity Detection in Streaming Video

abstract:
  Current approaches for activity recognition often ignore constraints on
computational resources: 1) they rely on extensive feature computation to
obtain rich descriptors on all frames, and 2) they assume batch-mode access to
the entire test video at once. We propose a new active approach to activity
recognition that prioritizes "what to compute when" in order to make timely
predictions. The main idea is to learn a policy that dynamically schedules the
sequence of features to compute on selected frames of a given test video. In
contrast to traditional static feature selection, our approach continually
re-prioritizes computation based on the accumulated history of observations and
accounts for the transience of those observations in ongoing video. We develop
variants to handle both the batch and streaming settings. On two challenging
datasets, our method provides significantly better accuracy than alternative
techniques for a wide range of computational budgets.


title:
Quenched Asymptotics for the Discrete Fourier Transforms of a Stationary
  Process

abstract:
  In this dissertation, we show that the Central Limit Theorem and the
Invariance Principle for Discrete Fourier Transforms discovered by Peligrad and
Wu can be extended to the quenched setting. We show that the random
normalization introduced to extend these results is necessary and we discuss
its meaning. We also show the validity of the quenched Invariance Principle for
fixed frequencies under some conditions of weak dependence. In particular, we
show that this result holds in the martingale case.
  The discussion needed for the proofs allows us to show some general facts
apparently not noticed before in the theory of convergence in distribution. In
particular, we show that in the case of separable metric spaces the set of test
functions in the Portmanteau theorem can be reduced to a countable one, which
implies that the notion of quenched convergence, given in terms of convergence
a.s. of conditional expectations, specializes in the right way in the regular
case when the state space is metrizable and second-countable.
  We also collect and organize several disperse facts from the existing theory
in a consistent manner towards the statistical spectral analysis of the
Discrete Fourier Transforms, providing a comprehensive introduction to topics
in this theory that apparently have not been systematically addressed in a
self-contained way by previous references.


title: On Universal Deformation Rings for Gorenstein Algebras

abstract:
  Let $\mathbf{k}$ be an algebraically closed field, and let $\Lambda$ be a
finite dimensional $\mathbf{k}$-algebra. We prove that if $\Lambda$ is a
Gorenstein algebra, then every finitely generated Cohen-Macaulay
$\Lambda$-module $V$ whose stable endomorphism ring is isomorphic to
$\mathbf{k}$ has a universal deformation ring $R(\Lambda,V)$, which is a
complete local commutative Noetherian $\mathbf{k}$-algebra with residue field
$\mathbf{k}$, and which is also stable under taking syzygies. We investigate a
particular non-self-injective Gorenstein algebra $\Lambda_0$, which is of
infinite global dimension and which has exactly three isomorphism classes of
finitely generated indecomposable Cohen-Macaulay $\Lambda_0$-modules $V$ whose
stable endomorphism ring is isomorphic to $\mathbf{k}$. We prove that in this
situation, $R(\Lambda_0,V)$ is isomorphic either to $\mathbf{k}$ or to
$\mathbf{k}[[t]]/(t^2)$.


title: The influence of quantum vacuum friction on pulsars

abstract:
  We firstly revisit the energy loss mechanism known as quantum vacuum friction
(QVF), clarifying some of its subtleties. Then we investigate the observables
that could easily differentiate QVF from the classical magnetic dipole
radiation for pulsars with braking indices (n) measured accurately. We show
this is specially the case for the time evolution of a pulsar's magnetic dipole
direction ($\dot{\phi}$) and surface magnetic field ($\dot{B}_0$). As it is
well known in the context of the classic magnetic dipole radiation, $n<3$ would
only be possible for positive $(\dot{B}_0/B_0 + \dot{\phi}/\tan\phi)$, which,
for instance, leads to $\dot{B}_0>0$ ($\dot{\phi}>0$) when $\phi$ ($B_0$) is
constant. On the other hand, we show that QVF can result in very contrasting
predictions with respect to the above ones. Finally, even in the case
$\dot{B}_0$ in both aforesaid models for a pulsar has the same sign, for a
given $\phi$, we show that they give rise to different associated timescales,
which could be another way to falsify QVF.


title:
Homoclinic Bifurcations that Give Rise to Heterodimensional Cycles near
  A Saddle-Focus Equilibrium

abstract:
  We show that heterodimensional cycles can be born at the bifurcations of a
pair of homoclinic loops to a saddle-focus equilibrium for flows in dimension 4
and higher. In addition to the classical heterodimensional connection between
two periodic orbits, we found two new types of heterodimensional connections:
one is a heteroclinic between a periodic orbit of index 2 and a homoclinic
loop, and the other connects a periodic orbit of index 3 to the saddle-focus
equilibrium.


title: Separably injective C*-algebras

abstract:
  We show that a C*-algebra is a $1$-separably injective Banach space if, and
only if, it is linearly isometric to the Banach space $C_0(\Omega)$ of complex
continuous functions vanishing at infinity on a substonean locally compact
Hausdorff space $\Omega$.


title: Adapting Models to Signal Degradation using Distillation

abstract:
  Model compression and knowledge distillation have been successfully applied
for cross-architecture and cross-domain transfer learning. However, a key
requirement is that training examples are in correspondence across the domains.
We show that in many scenarios of practical importance such aligned data can be
synthetically generated using computer graphics pipelines allowing domain
adaptation through distillation. We apply this technique to learn models for
recognizing low-resolution images using labeled high-resolution images,
non-localized objects using labeled localized objects, line-drawings using
labeled color images, etc. Experiments on various fine-grained recognition
datasets demonstrate that the technique improves recognition performance on the
low-quality data and beats strong baselines for domain adaptation. Finally, we
present insights into workings of the technique through visualizations and
relating it to existing literature.


title: Joint Optimization of Power and Data Transfer in Multiuser MIMO Systems

abstract:
  We present an approach to solve the nonconvex optimization problem that
arises when designing the transmit covariance matrices in multiuser
multiple-input multiple-output (MIMO) broadcast networks implementing
simultaneous wireless information and power transfer (SWIPT). The MIMO SWIPT
problem is formulated as a general multi-objective optimization problem, in
which data rates and harvested powers are optimized simultaneously. Two
different approaches are applied to reformulate the (nonconvex) multi-objective
problem. In the first approach, the transmitter can control the specific amount
of power to be harvested by power transfer whereas in the second approach the
transmitter can only control the proportion of power to be harvested among the
different harvesting users. The computational complexity will also be
different, with higher computational resources required in the first approach.
In order to solve the resulting formulations, we propose to use the
majorization-minimization (MM) approach. The idea behind this approach is to
obtain a convex function that approximates the nonconvex objective and, then,
solve a series of convex subproblems that will converge to a locally optimal
solution of the general nonconvex multi-objective problem. The solution
obtained from the MM approach is compared to the classical
block-diagonalization (BD) strategy, typically used to solve the nonconvex
multiuser MIMO network by forcing no interference among users. Simulation
results show that the proposed approach improves over the BD approach both the
system sum rate and the power harvested by users. Additionally, the
computational times needed for convergence of the proposed methods are much
lower than the ones required for classical gradient-based approaches.


title: Galaxy Zoo: Mergers - Dynamical Models of Interacting Galaxies

abstract:
  The dynamical history of most merging galaxies is not well understood.
Correlations between galaxy interaction and star formation have been found in
previous studies, but require the context of the physical history of merging
systems for full insight into the processes that lead to enhanced star
formation. We present the results of simulations that reconstruct the orbit
trajectories and disturbed morphologies of pairs of interacting galaxies. With
the use of a restricted three-body simulation code and the help of Citizen
Scientists, we sample 10^5 points in parameter space for each system. We
demonstrate a successful recreation of the morphologies of 62 pairs of
interacting galaxies through the review of more than 3 million simulations. We
examine the level of convergence and uniqueness of the dynamical properties of
each system. These simulations represent the largest collection of models of
interacting galaxies to date, providing a valuable resource for the
investigation of mergers. This paper presents the simulation parameters
generated by the project. They are now publicly available in electronic format
at http://data.galaxyzoo.org/mergers.html. Though our best-fit model parameters
are not an exact match to previously published models, our method for
determining uncertainty measurements will aid future comparisons between
models. The dynamical clocks from our models agree with previous results of the
time since the onset of star formation from star burst models in interacting
systems and suggests that tidally induced star formation is triggered very soon
after closest approach.


title: On the Poncelet triangle condition over finite fields

abstract:
  Let ${\mathbf P}^2$ denote the projective plane over a finite field ${\mathbb
F}_q$. A pair of nonsingular conics $({\mathcal A}, {\mathcal B})$ in the plane
is said to satisfy the Poncelet triangle condition if, considered as conics in
${\mathbf P}^2({\overline{\mathbb F}}_q)$, they intersect transverally and
there exists a triangle inscribed in ${\mathcal A}$ and circumscribed around
${\mathcal B}$. It is shown in this article that a randomly chosen pair of
conics satisfies the triangle condition with asymptotic probability $1/q$. We
also make a conjecture based upon computer experimentation which predicts this
probability for tetragons, pentagons and so on up to enneagons.


title:
A priori estimates for rough PDEs with application to rough conservation
  laws

abstract:
  We introduce a general weak formulation for PDEs driven by rough paths, as
well as a new strategy to prove well-posedness. Our procedure is based on a
combination of fundamental a priori estimates with (rough) Gronwall-type
arguments. In particular this approach does not rely on any sort of
transformation formula (flow transformation, Feynman--Kac representation
formula etc.) and is therefore rather flexible. As an application, we study
conservation laws driven by rough paths establishing well--posedness for the
corresponding kinetic formulation.


title: Some results on chromatic number as a function of triangle count

abstract:
  A variety of powerful extremal results have been shown for the chromatic
number of triangle-free graphs. Three noteworthy bounds are in terms of the
number of vertices, edges, and maximum degree given by Poljak \& Tuza (1994),
and Johansson. There have been comparatively fewer works extending these types
of bounds to graphs with a small number of triangles. One noteworthy exception
is a result of Alon et. al (1999) bounding the chromatic number for graphs with
low degree and few triangles per vertex; this bound is nearly the same as for
triangle-free graphs. This type of parametrization is much less rigid, and has
appeared in dozens of combinatorial constructions.
  In this paper, we show a similar type of result for $\chi(G)$ as a function
of the number of vertices $n$, the number of edges $m$, as well as the triangle
count (both local and global measures). Our results smoothly interpolate
between the generic bounds true for all graphs and bounds for triangle-free
graphs. Our results are tight for most of these cases; we show how an open
problem regarding fractional chromatic number and degeneracy in triangle-free
graphs can resolve the small remaining gap in our bounds.


title:
The Sensitivity of the Advanced LIGO Detectors at the Beginning of
  Gravitational Wave Astronomy

abstract:
  The Laser Interferometer Gravitational Wave Observatory (LIGO) consists of
two widely separated 4 km laser interferometers designed to detect
gravitational waves from distant astrophysical sources in the frequency range
from 10 Hz to 10 kHz. The first observation run of the Advanced LIGO detectors
started in September 2015 and ended in January 2016. A strain sensitivity of
better than $10^{-23}/\sqrt{\text{Hz}}$ was achieved around 100 Hz.
Understanding both the fundamental and the technical noise sources was critical
for increasing the observable volume in the universe. The average distance at
which coalescing binary black hole systems with individual masses of 30
$M_\odot$ could be detected was 1.3 Gpc. Similarly, the range for binary
neutron star inspirals was about 75 Mpc. With respect to the initial detectors,
the observable volume of Universe increased respectively by a factor 69 and 43.
These improvements allowed Advanced LIGO to detect the gravitational wave
signal from the binary black hole coalescence, known as GW150914.


title: Stop searches in flavourful supersymmetry

abstract:
  Natural realisations of supersymmetry require light stops ${\tilde t}_1$,
making them a prime target of LHC searches for physics beyond the Standard
Model. Depending on the kinematic region, the main search channels are ${\tilde
t_1}\to t \tilde \chi^0_1$, ${\tilde t_1}\to W b \tilde \chi^0_1$ and ${\tilde
t_1}\to c \tilde \chi^0_1$. We first examine the interplay of these decay modes
with ${\tilde c_1}\to c \tilde \chi^0_1$ in a model-independent fashion,
revealing the existence of large regions in parameter space which are excluded
for any ${\tilde t_1}\to c \tilde \chi^0_1$ branching ratio. This effect is
then illustrated for scenarios with stop-scharm mixing in the right-handed
sector, where it has previously been observed that the stop mass limits can be
significantly weakened for large mixing. Our analysis shows that once the LHC
bounds from ${\tilde c_1}\to c \tilde \chi^0_1$ searches are taken into
account, non-zero stop-scharm mixing leads only to a modest increase in the
allowed regions of parameter space, with large areas excluded for arbitrary
mixing angles.


title: A novel workflow for seismic net pay estimation with uncertainty

abstract:
  This paper presents a novel workflow for seismic net pay estimation with
uncertainty. It is demonstrated on the Cassra/Iris Field. The theory for the
stochastic wavelet derivation (which estimates the seismic noise level along
with the wavelet, time-to-depth mapping, and their uncertainties), the
stochastic sparse spike inversion, and the net pay estimation (using secant
areas) along with its uncertainty; will be outlined. This includes benchmarking
of this methodology on a synthetic model. A critical part of this process is
the calibration of the secant areas. This is done in a two step process. First,
a preliminary calibration is done with the stochastic reflection response
modeling using rock physics relationships derived from the well logs. Second, a
refinement is made to the calibration to account for the encountered net pay at
the wells. Finally, a variogram structure is estimated from the extracted
secant area map, then used to build in the lateral correlation to the ensemble
of net pay maps while matching the well results to within the nugget of the
variogram. These net pay maps are then integrated, over the area of full
saturation gas, to give the GIIP distribution (Gaussian distributions for the
porosity, gas expansion factor, and gas saturation for the sand end member are
assumed and incorporated in the estimate of GIIP). The method is demonstrated
on the Iris (UP5 turbidite) interval. The net pay is corrected for reduction in
the amplitudes over part of the area due to shallow gas. The sensitivity of the
GIIP to the independent stochastic variables is estimated (determining the
value of information) so that business decisions can be made that maximize the
value of the field.