title: White Dwarfs in the Metal-Rich Open Cluster NGC 6253

abstract:
  We have obtained 53 images with the $g$ filter and 19 images with the $i$
filter, each with 600-second exposures of the super metal rich open cluster NGC
6253 with the Gemini-South telescope to create deep images of the cluster to
observe the cluster white dwarfs for the first time. We will analyze the white
dwarf luminosity function to measure the cluster's white dwarf age, search for
any anomalous features (as has been seen in the similarly metal rich cluster
NGC 6791), and constrain the initial-final mass relation at high metallicities.
We present an update on these observations and our program to study the
formation of white dwarfs in super high metallicity environments.


title: Ramsey goodness of bounded degree trees

abstract:
  Given a pair of graphs $G$ and $H$, the Ramsey number $R(G,H)$ is the
smallest $N$ such that every red-blue coloring of the edges of the complete
graph $K_N$ contains a red copy of $G$ or a blue copy of $H$. If a graph $G$ is
connected, it is well known and easy to show that $R(G,H) \geq
(|G|-1)(\chi(H)-1)+\sigma(H)$, where $\chi(H)$ is the chromatic number of $H$
and $\sigma(H)$ is the size of the smallest color class in a $\chi(H)$-coloring
of $H$. A graph $G$ is called $H$-good if $R(G,H)=
(|G|-1)(\chi(H)-1)+\sigma(H)$. The notion of Ramsey goodness was introduced by
Burr and Erd\H{o}s in 1983 and has been extensively studied since then.
  In this paper we show that if $n\geq \Omega(|H| \log^4 |H|)$ then every
$n$-vertex bounded degree tree $T$ is $H$-good. The dependency between $n$ and
$|H|$ is tight up to $\log$ factors. This substantially improves a result of
Erd\H{o}s, Faudree, Rousseau, and Schelp from 1985, who proved that $n$-vertex
bounded degree trees are $H$-good when when $n \geq \Omega(|H|^4)$.


title:
Many-body computations by stochastic sampling in Hartree-Fock-Bogoliubov
  space

abstract:
  We describe the computational ingredients for an approach to treat
interacting fermion systems in the presence of pairing fields, based on
path-integrals in the space of Hartree-Fock-Bogoliubov (HFB) wave functions.
The path-integrals can be evaluated by Monte Carlo, via random walks of HFB
wave functions whose orbitals evolve stochastically. The approach combines the
advantage of HFB theory in paired fermion systems and many-body quantum Monte
Carlo (QMC) techniques. The properties of HFB states, written in the form of
either product states or Thouless states, are discussed. The states are shown
to be propagated by generalized one-body operators. The states can be
stabilized for numerical iteration, and overlaps between two such states and
one-body Green's functions can be computed. A constrained-path or phaseless
approximation can be applied to the random walks of the HFB states if a sign
problem or phase problem is present. The method is illustrated with an exact
numerical projection in the Kitaev model, and in the Hubbard model with
attractive interaction under an external pairing field.


title:
A Multi-State Conditional Logistic Regression Model for the Analysis of
  Animal Movement

abstract:
  A multi-state version of an animal movement analysis method based on
conditional logistic regression, called Step Selection Function (SSF), is
proposed. In ecology SSF is developed from a comparison between the observed
location of an animal and randomly sampled locations at each time step.
Interpretation of the parameters in the multi-state model and the impact of
different sampling schemes for the random locations are discussed. We prove the
equivalence between the new model and a random walk model on the plane. This
equivalence allows one to use both pure movement and local discrete choice
behaviors in identifying the model's hidden states. The new method is used to
model the movement behavior of GPS-collared bison in Prince Albert National
Park, Canada. The multi-state SSF successfully teases apart areas used to
forage and to travel. The analysis thus provides valuable insights into how
bison adjust their movement to habitat features, thereby revealing spatial
determinants of functional connectivity in heterogeneous landscapes.


title:
Comparison of Gluon Bundle based QCD Curves with ISR Elastic pp
  Scattering Data

abstract:
  Using previously described functional techniques for exact, non-perturbative,
gauge-invariant renormalized QCD processes, a simplified version of the
amplitudes - in which forms akin to Pomerons naturally appear - provides fits
to ISR Elastic pp scattering data. Extension of this work to LHC reactions is
presently underway.


title: Electromagnetic and transport properties of QGP within PLSM approach

abstract:
  In order to study the response of the quantum chromodynamic matter to finite
electromagnetic fields, we utilize the Polyakov linear - sigma model (PLSM) in
mean-field approximation. Due to participants' momentum imbalance and
off-center relativistic motion of the spectators' electric charges, localized,
short-lived, huge electromagnetic fields are to be generated in the
relativistic heavy-ion collisions. We report on various electromagnetic and
transport properties of the new-state-of matter; the quark-gluon plasma (QGP)
within the QCD-like approach, PLSM. We find an excellent agreement between our
PLSM calculations and various recent lattice QCD simulations and notice that
the magnetization and the magnetic susceptibility and the relative permeability
obviously increase in the QGP phase. We predict that increasing the magnetic
field remarkable decreases the viscosity, especially in hadron phase. while in
QGP phase, the viscous properties seem not being affected with.


title: SU($4$) Polyakov linear-sigma model at finite temperature and density

abstract:
  In mean-field approximation, the SU($4$) Polyakov linear - sigma model (PLSM)
is constructed in order to characterize the quark-hadron phase structure in a
wide range of temperatures and densities. The chiral condensates $\sigma_l$,
$\sigma_s$ and $\sigma_c$ for light, strange and charm quarks, respectively,
and the deconfinement order-parameters $\phi$ and $\phi^*$ shall be analyzed at
finite temperatures and densities. We conclude that the critical temperatures
corresponding to charm condensates are greater than that to strange and light
ones, respectively. Thus, the charm condensates are likely not affected by the
QCD phase transition. Furthermore, increasing the chemical potentials decreases
the corresponding critical temperatures.


title: Notes on countably generated complete Boolean algebras

abstract:
  We give a necessary and sufficient condition for an atomless Boolean algebra
to be countably generated, and use it to give new proofs of some some know
facts due to Gaifman-Hales and Solovay and also due to Jech, Kunen and Magidor.
We also show that Jensen's coding theorem can be used to provide cardinal
preserving countably generated complete Boolean algebras of arbitrary large
cardinality. This answers a question of Jech [5] from 1976.


title:
Automatic recognition of child speech for robotic applications in noisy
  environments

abstract:
  Automatic speech recognition (ASR) allows a natural and intuitive interface
for robotic educational applications for children. However there are a number
of challenges to overcome to allow such an interface to operate robustly in
realistic settings, including the intrinsic difficulties of recognising child
speech and high levels of background noise often present in classrooms. As part
of the EU EASEL project we have provided several contributions to address these
challenges, implementing our own ASR module for use in robotics applications.
We used the latest deep neural network algorithms which provide a leap in
performance over the traditional GMM approach, and apply data augmentation
methods to improve robustness to noise and speaker variation. We provide a
close integration between the ASR module and the rest of the dialogue system,
allowing the ASR to receive in real-time the language models relevant to the
current section of the dialogue, greatly improving the accuracy. We integrated
our ASR module into an interactive, multimodal system using a small humanoid
robot to help children learn about exercise and energy. The system was
installed at a public museum event as part of a research study where 320
children (aged 3 to 14) interacted with the robot, with our ASR achieving 90%
accuracy for fluent and near-fluent speech.


title: Reduced Graphene Oxide and Its Natural Counterpart Shungite Carbon

abstract:
  Large variety of structure and chemical-composition of reduced graphene oxide
(RGO) is explained from a quantum-chemical standpoint. The related molecular
theory of graphene oxide, supported by large experience gained by the modern
graphene science, has led the foundation of the concept of a multi-stage
graphene oxide reduction. This microscopic approach has found a definite
confirmation when analyzing the available empirical data concerning both
synthetic and natural RGO products, the latter in view of shungite carbon,
suggesting the atomic-microscopic model for its structure.


title:
Calculation of gluon contribution to the proton spin by using the
  non-perturbative quantization \`a la Heisenberg

abstract:
  The contribution of crossed gluon fields in flux tubes connecting quarks to
the proton spin is calculated. The calculations are performed following
non-perturbative Heisenberg's quantization technique. In our approach a proton
is considered as consisting of three quarks connected by three flux tubes. The
flux tubes contain color longitudinal electric and transversal electric and
magnetic fields. The transversal fields causes the appearance of the angular
momentum density. The dimensionless relation between the angular momentum and
the mass of the gluon fields is obtained. The contribution to proton spin from
rotating quarks and flux tubes connecting quarks is estimated. Simple numerical
relation between the proton mass, the speed of light and the proton radius,
which is of the same order as the Planck constant, is discussed.


title: Emulated Inertia and Damping of Converter-Interfaced Power Source

abstract:
  Converter-interfaced power sources (CIPSs), like wind turbine and energy
storage, can be switched to the inertia emulation mode when the detected
frequency deviation exceeds a pre-designed threshold, i.e. dead band, to
support the frequency response of a power grid. This letter proposes an
approach to derive the emulated inertia and damping from a CIPS based on the
linearized model of the CIPS and the power grid, where the grid is represented
by an equivalent single machine. The emulated inertia and damping can be
explicitly expressed in time and turn out to be time-dependent.


title: Making Distinct Dynamical Systems Appear Spectrally Identical

abstract:
  We show that a laser pulse can always be found that induces a desired optical
response from an arbitrary dynamical system. As illustrations, driving fields
are computed to induce the same optical response from a variety of distinct
systems (open and closed, quantum and classical). As a result, the observed
induced dipolar spectra without detailed information on the driving field is
not sufficient to characterize atomic and molecular systems. The formulation
may also be applied to design materials with specified optical characteristics.
These findings reveal unexplored flexibilities of nonlinear optics.


title:
The LOFAR Two-metre Sky Survey - I. Survey Description and Preliminary
  Data Release

abstract:
  The LOFAR Two-metre Sky Survey (LoTSS) is a deep 120-168 MHz imaging survey
that will eventually cover the entire Northern sky. Each of the 3170 pointings
will be observed for 8 hrs, which, at most declinations, is sufficient to
produce ~5arcsec resolution images with a sensitivity of ~0.1mJy/beam and
accomplish the main scientific aims of the survey which are to explore the
formation and evolution of massive black holes, galaxies, clusters of galaxies
and large-scale structure. Due to the compact core and long baselines of LOFAR,
the images provide excellent sensitivity to both highly extended and compact
emission. For legacy value, the data are archived at high spectral and time
resolution to facilitate subarcsecond imaging and spectral line studies. In
this paper we provide an overview of the LoTSS. We outline the survey strategy,
the observational status, the current calibration techniques, a preliminary
data release, and the anticipated scientific impact. The preliminary images
that we have released were created using a fully-automated but
direction-independent calibration strategy and are significantly more sensitive
than those produced by any existing large-area low-frequency survey. In excess
of 44,000 sources are detected in the images that have a resolution of
25arcsec, typical noise levels of less than 0.5 mJy/beam, and cover an area of
over 350 square degrees in the region of the HETDEX Spring Field (right
ascension 10h45m00s to 15h30m00s and declination 45d00m00s to 57d00m00s).


title: Three Dimensional Visualization of Qutrit States

abstract:
  The qutrit comes next in complexity after qubit as a resource for quantum
information processing. The qubit density matrix can be easily visualized using
Bloch sphere representation of its states. In contrast, this simplicity is in
general unavailable for the 8-dimensional state space of a qutrit. In this work
a new way to visualize them in a 3-dimensional Cartesian space is presented and
compared with earlier similar efforts.


title: Toward a Holographic Theory for General Spacetimes

abstract:
  We study a holographic theory of general spacetimes that does not rely on the
existence of asymptotic regions. This theory is to be formulated in a
holographic space. When a semiclassical description is applicable, the
holographic space is assumed to be a holographic screen: a codimension-1
surface that is capable of encoding states of the gravitational spacetime. Our
analysis is guided by conjectured relationships between gravitational spacetime
and quantum entanglement in the holographic description. To understand basic
features of this picture, we catalog predictions for the holographic
entanglement structure of cosmological spacetimes. We find that qualitative
features of holographic entanglement entropies for such spacetimes differ from
those in AdS/CFT but that the former reduce to the latter in the appropriate
limit. The Hilbert space of the theory is analyzed, and two plausible
structures are found: a direct sum and "spacetime equals entanglement"
structure. The former preserves a naive relationship between linear operators
and observable quantities, while the latter respects a more direct connection
between holographic entanglement and spacetime. We also discuss the issue of
selecting a state in quantum gravity, in particular how the state of the
multiverse may be selected in the landscape.


title: Lepton Flavor Non-Universality in B decays from Dynamical Yukawas

abstract:
  The basic features of quark and lepton mass matrices can be successfully
explained by natural minima of a generic potential with dynamical Yukawa fields
invariant under the $[\mathrm{SU(3)}]^5\times \mathcal{O}(3)$ flavor symmetry.
If this symmetry is gauged, in order to avoid potentially dangerous Goldstone
bosons, and small perturbations are added to exactly fit the observed pattern
of fermion masses, the spectrum of massive flavor gauge bosons can naturally
explain the hints for new physics in $b\to s \ell^+\ell^-$ transitions,
including $R_K$. In particular, the desired pattern of the Standard Model
Yukawa couplings is compatible with a gauged $\mathrm{U(1)}_q$ in the quark
sector, and $\mathrm{U(1)}_{\mu-\tau}$ in the lepton sector spontaneously
broken around the TeV scale. In order to explain the aforementioned
experimental hints, the corresponding neutral gauge bosons are required to mix,
yielding to potentially observable signals in dimuon resonance searches at the
LHC.


title: Accelerating the BSM interpretation of LHC data with machine learning

abstract:
  The interpretation of Large Hadron Collider (LHC) data in the framework of
Beyond the Standard Model (BSM) theories is hampered by the need to run
computationally expensive event generators and detector simulators. Performing
statistically convergent scans of high-dimensional BSM theories is consequently
challenging, and in practice unfeasible for very high-dimensional BSM theories.
We present here a new machine learning method that accelerates the
interpretation of LHC data, by learning the relationship between BSM theory
parameters and data. As a proof-of-concept, we demonstrate that this technique
accurately predicts natural SUSY signal events in two signal regions at the
High Luminosity LHC, up to four orders of magnitude faster than standard
techniques. The new approach makes it possible to rapidly and accurately
reconstruct the theory parameters of complex BSM theories, should an excess in
the data be discovered at the LHC.


title: Heavy Fields and Gravity

abstract:
  We study the effects of heavy fields on 4D spacetimes with flat, de Sitter
and anti-de Sitter asymptotics. At low energies, matter generates specific,
calculable higher derivative corrections to the GR action which perturbatively
alter the Schwarzschild-$(A)dS$ family of solutions. The effects of massive
scalars, Dirac spinors and gauge fields are each considered. The six-derivative
operators they produce, such as $\sim R^{3}$ terms, generate the leading
corrections. The induced changes to horizon radii, Hawking temperatures and
entropies are found. Modifications to the energy of large $AdS$ black holes are
derived by imposing the first law. An explicit demonstration of the replica
trick is provided, as it is used to derive black hole and cosmological horizon
entropies. Considering entropy bounds, it's found that scalars and fermions
increase the entropy one can store inside a region bounded by a sphere of fixed
size, but vectors lead to a decrease, oddly. We also demonstrate, however, that
many of the corrections fall below the resolving power of the effective field
theory and are therefore untrustworthy. Defining properties of black holes,
such as the horizon area and Hawking temperature, prove to be remarkably robust
against higher derivative gravitational corrections.


title: The WEAVE-LOFAR Survey

abstract:
  In these proceedings we highlight the primary scientific goals and design of
the WEAVE-LOFAR survey, which will use the new WEAVE spectrograph on the 4.2m
William Herschel Telescope to provide the primary source of spectroscopic
information for the LOFAR Surveys Key Science Project. Beginning in 2018,
WEAVE-LOFAR will generate more than 10$^6$ R=5000 365-960 nm spectra of
low-frequency selected radio sources, across three tiers designed to
efficiently sample the redshift-luminosity plane, and produce a data set of
enormous legacy value. The radio frequency selection, combined with the high
multiplex and throughput of the WEAVE spectrograph, make obtaining redshifts in
this way very efficient, and we expect that the redshift success rate will
approach 100 per cent at $z < 1$. This unprecedented spectroscopic sample -
which will be complemented by an integral field component - will be
transformational in key areas, including studying the star formation history of
the Universe, the role of accretion and AGN-driven feedback, properties of the
epoch of reionisation, cosmology, cluster haloes and relics, as well as the
nature of radio galaxies and protoclusters. Each topic will be addressed in
unprecedented detail, and with the most reliable source classifications and
redshift information in existence.


title: High-resolution studies of the Majorana atomic chain platform

abstract:
  Ordered assemblies of magnetic atoms on the surface of conventional
superconductors can be used to engineer topological superconducting phases and
realize Majorana fermion quasiparticles (MQPs) in a condensed matter setting.
Recent experiments have shown that chains of Fe atoms on Pb generically have
the required electronic characteristics to form a 1D topological superconductor
and have revealed spatially resolved signatures of localized MQPs at the ends
of such chains. Here we report higher resolution measurements of the same
atomic chain system performed using a dilution refrigerator scanning tunneling
microscope (STM). With significantly better energy resolution than previous
studies, we show that the zero bias peak (ZBP) in Fe chains has no detectable
splitting from hybridization with other states. The measurements also reveal
that the ZBP exhibits a distinctive 'double eye' spatial pattern on nanometer
length scales. Theoretically we show that this is a general consequence of STM
measurements of MQPs with substantial spectral weight in the superconducting
substrate, a conclusion further supported by measurements of Pb overlayers
deposited on top of the Fe chains. Finally, we report experiments performed
with superconducting tips in search of the particle-hole symmetric MQP
signature expected in such measurements.


title:
Ultra Violet Escape Fractions from Giant Molecular Clouds During Early
  Cluster Formation

abstract:
  The UV photon escape fraction from molecular clouds is a key parameter for
understanding the ionization of the Interstellar Medium (ISM), and
extragalactic processes, such as cosmic reionization. We present the ionizing
photon flux and the corresponding photon escape fraction (f$_{esc}$) arising as
a consequence of star cluster formation in a turbulent, 10$^6$ M$_{\odot}$ GMC,
simulated using the code FLASH. We make use of sink particles to represent
young, star-forming clusters coupled with a radiative transfer scheme to
calculate the emergent UV flux. We find that the ionizing photon flux across
the cloud boundary is highly variable in time and space due to the turbulent
nature of the intervening gas. The escaping photon fraction remains at $\sim$5%
for the first 2.5 Myr, followed by two pronounced peaks at 3.25 and 3.8 Myr
with a maximum f$_{esc}$ of 30% and 37%, respectively. These peaks are due to
the formation of large HII regions, that expand into regions of lower density
and some of which reach the cloud surface. However, these phases are short
lived and f$_{esc}$ drops sharply as the HII regions are quenched by the
central cluster passing through high-density material due to the turbulent
nature of the cloud. We find an average f$_{esc}$ of 15% with factor of two
variations over 1 Myr timescales. Our results suggest that assuming a single
value for f$_{esc}$ from a molecular cloud is in general a poor approximation,
and that the dynamical evolution of the system leads to large temporal
variation.


title:
OGLE-ing the Magellanic System: Three-Dimensional Structure of the
  Clouds and the Bridge Using RR Lyrae Stars

abstract:
  We present a three-dimensional analysis of a sample of 22 859 type $ab$ RR
Lyrae stars in the Magellanic System from the OGLE-IV Collection of RR Lyrae
stars. The distance to each object was calculated based on its photometric
metallicity and a theoretical relation between color, absolute magnitude and
metallicity.
  The LMC RR Lyrae distribution is very regular and does not show any
substructures. We demonstrate that the bar found in previous studies may be an
overdensity caused by blending and crowding effects. The halo is asymmetrical
with a higher stellar density in its north-eastern area, which is also located
closer to us. Triaxial ellipsoids were fitted to surfaces of a constant number
density. Ellipsoids farther from the LMC center are less elongated and slightly
rotated toward the SMC. The inclination and position angle change significantly
with the $a$ axis size. The median axis ratio is $1:1.23:1.45$.
  The RR Lyrae distribution in the SMC has a very regular, ellipsoidal shape
and does not show any substructures or asymmetries. All triaxial ellipsoids
fitted to surfaces of a constant number density have virtually the same shape
(axis ratio) and are elongated along the line of sight. The median axis ratio
is $1:1.10:2.13$. The inclination angle is very small and thus the position
angle is not well defined.
  We present the distribution of RR Lyrae stars in the Magellanic Bridge area,
showing that the Magellanic Clouds' halos overlap.
  A comparison of the distributions of RR Lyrae stars and Classical Cepheids
shows that the former are significantly more spread and distributed regularly,
while the latter are very clumped and form several distinct substructures.


title: AGN jet-driven stochastic cold accretion in cluster cores

abstract:
  Several arguments suggest that stochastic condensation of cold gas and its
accretion onto the central supermassive black hole (SMBH) is essential for
active galactic nuclei (AGN) feedback to work in the most massive galaxies that
lie at the centres of galaxy clusters. Our 3-D hydrodynamic AGN jet-ICM
(intracluster medium) simulations, looking at the detailed angular momentum
distribution of cold gas and its time variability for the first time, show that
the angular momentum of the cold gas crossing $\lesssim 1$ kpc is essentially
isotropic. With almost equal mass in clockwise and counter-clockwise
orientations, we expect a cancellation of angular momentum on roughly the
dynamical time. This means that a compact accretion flow with a short viscous
time ought to form, through which enough accretion power can be channeled into
jet mechanical energy sufficiently quickly to prevent a cooling flow. The
inherent stochasticity, expected in feedback cycles driven by cold gas
condensation, gives rise to a large variation in the cold gas mass at the
centres of galaxy clusters, for similar cluster and SMBH masses, in agreement
with the observations. Such correlations are expected to be much tighter for
the smoother hot/Bondi accretion. The weak correlation between cavity power and
Bondi power obtained from our simulations also match observations.


title: Large Fluctuations in the High-Redshift Metagalactic Ionizing Background

abstract:
  Recent observations have shown that the scatter in opacities among coeval
segments of the Lyman-alpha forest increases rapidly at z > 5. In this paper,
we assess whether the large scatter can be explained by fluctuations in the
ionizing background in the post-reionization intergalactic medium. We find that
matching the observed scatter at z ~ 5.5 requires a short spatially averaged
mean free path of < 15 comoving Mpc/h, a factor of > 3 shorter than direct
measurements at z ~ 5.2. We argue that such rapid evolution in the mean free
path is difficult to reconcile with our measurements of the global H I
photoionization rate, which stay approximately constant over the interval z ~
4.8 - 5.5. However, we also show that measurements of the mean free path at z >
5 are likely biased towards higher values by the quasar proximity effect. This
bias can reconcile the short values of the mean free path that are required to
explain the large scatter in opacities. We discuss the implications of this
scenario for cosmological reionization. Finally, we investigate whether other
statistics applied to the z > 5 Lyman-alpha forest can shed light on the origin
of the scatter. Compared to a model with a uniform ionizing background, models
that successfully account for the scatter lead to enhanced power in the
line-of-sight flux power spectrum on scales k < 0.1 h/Mpc. We find tentative
evidence for this enhancement in observations of the high-redshift Lyman-alpha
forest.


title:
Using the Multi-Object Adaptive Optics demonstrator RAVEN to observe
  metal-poor stars in and towards the Galactic Centre

abstract:
  The chemical abundances for five metal-poor stars in and towards the Galactic
bulge have been determined from H-band infrared spectroscopy taken with the
RAVEN multi-object adaptive optics science demonstrator and the IRCS
spectrograph at the Subaru 8.2-m telescope. Three of these stars are in the
Galactic bulge and have metallicities between -2.1 < [Fe/H] < -1.5, and high
[alpha/Fe] ~+0.3, typical of Galactic disk and bulge stars in this metallicity
range; [Al/Fe] and [N/Fe] are also high, whereas [C/Fe] < +0.3. An examination
of their orbits suggests that two of these stars may be confined to the
Galactic bulge and one is a halo trespasser, though proper motion values used
to calculate orbits are quite uncertain. An additional two stars in the
globular cluster M22 show [Fe/H] values consistent to within 1 sigma, although
one of these two stars has [Fe/H] = -2.01 +/- 0.09, which is on the low end for
this cluster. The [alpha/Fe] and [Ni/Fe] values differ by 2 sigma, with the
most metal-poor star showing significantly higher values for these elements.
M22 is known to show element abundance variations, consistent with a
multi-population scenario (i.e. Marino et al. 2009, 2011; Alves-Brito et al.
2012) though our results cannot discriminate this clearly given our abundance
uncertainties. This is the first science demonstration of multi-object adaptive
optics with high resolution infrared spectroscopy, and we also discuss the
feasibility of this technique for use in the upcoming era of 30-m class
telescope facilities.


title:
Evidence for Reduced Specific Star Formation Rates in the Centers of
  Massive Galaxies at z = 4

abstract:
  We perform the first spatially-resolved stellar population study of galaxies
in the early universe (z = 3.5 - 6.5), utilizing the Hubble Space Telescope
Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS)
imaging dataset over the GOODS-S field. We select a sample of 418 bright and
extended galaxies at z = 3.5 - 6.5 from a parent sample of ~ 8000
photometric-redshift selected galaxies from Finkelstein et al. (2015). We first
examine galaxies at 3.5< z < 4.0 using additional deep K-band survey data from
the HAWK-I UDS and GOODS Survey (HUGS) which covers the 4000A break at these
redshifts. We measure the stellar mass, star formation rate, and dust
extinction for galaxy inner and outer regions via spatially-resolved spectral
energy distribution fitting based on a Markov Chain Monte Carlo algorithm. By
comparing specific star formation rates (sSFRs) between inner and outer parts
of the galaxies we find that the majority of galaxies with the high central
mass densities show evidence for a preferentially lower sSFR in their centers
than in their outer regions, indicative of reduced sSFRs in their central
regions. We also study galaxies at z ~ 5 and 6 (here limited to high spatial
resolution in the rest-frame ultraviolet only), finding that they show sSFRs
which are generally independent of radial distance from the center of the
galaxies. This indicates that stars are formed uniformly at all radii in
massive galaxies at z ~ 5 - 6, contrary to massive galaxies at z < 4.


title:
The Doppler effect on indirect detection of dark matter using dark
  matter only simulations

abstract:
  Indirect detection of dark matter is a major avenue for discovery. However,
baryonic backgrounds are diverse enough to mimic many possible signatures of
dark matter. In this work, we study the newly proposed technique of dark matter
velocity spectroscopy\,\cite{speckhard2016}. The non-rotating dark matter halo
and the Solar motion produce a distinct longitudinal dependence of the signal
which is opposite in direction to that produced by baryons. Using collisionless
dark matter only simulations of Milky Way like halos, we show that this new
signature is robust and holds great promise. We develop mock observations by
high energy resolution X-ray spectrometer on a sounding rocket, the Micro-X
experiment, to our test case, the 3.5 keV line. We show that by using six
different pointings, Micro-X can exclude a constant line energy over various
longitudes at $\geq$ 3$\sigma$. The halo triaxiality is an important effect and
it will typically reduce the significance of this signal. We emphasize that
this new {\it smoking gun in motion} signature of dark matter is general, and
is applicable to any dark matter candidate which produces a sharp photon
feature in annihilation or decay.

categories: astro-ph.CO astro-ph.HE astro-ph.IM hep-ex hep-ph


title:
The SpaceInn-SISMA database: characterization of a large sample of
  variable and active stars by means of HARPS spectra

abstract:
  We created a large database of physical parameters and variability indicators
by fully reducing and analysing the large number of spectra taken to complement
the asteroseismic observations of the CoRoT satellite. 7103 spectra of 261
stars obtained with the ESO echelle spectrograph HARPS have been stored in the
VO-compliant database Spectroscopic Indicators in a SeisMic Archive (SISMA),
along with the CoRoT photometric data of the 72 CoRoT asteroseismic targets.
The remaining stars belong to the same variable classes of the CoRoT targets
and were observed to better characterize the properties of such classes.
Several useful variability indicators (mean line profiles; indices of
differential rotation, activity and emission lines) together with vsini and
radial velocity measurements have been extracted from the spectra. The
atmospheric parameters Teff, logg and [Fe/H] have been computed following a
homogeneous procedure. As a result, we fully characterize a sample of new and
known variable stars by computing several spectroscopic indicators, also
providing some cases of simultaneous photometry and spectroscopy.


title:
How the Self-Interacting Dark Matter Model Explains the Diverse Galactic
  Rotation Curves

abstract:
  The rotation curves of spiral galaxies exhibit a diversity that has been
difficult to understand in the cold dark matter (CDM) paradigm. We show that
the self-interacting dark matter (SIDM) model provides excellent fits to the
rotation curves of a sample of galaxies with asymptotic velocities in the 25 to
300 km/s range that exemplify the full range of diversity. We only assume the
halo concentration-mass relation predicted by the CDM model and a fixed value
of the self-interaction cross section.In dark matter dominated galaxies,
thermalization due to self-interactions creates large cores and reduces dark
matter densities. In contrast, thermalization leads to denser and smaller cores
in more luminous galaxies, and naturally explains the flat rotation curves of
the highly luminous galaxies. Our results demonstrate that the impact of the
baryons on the SIDM halo profile and the scatter from the assembly history of
halos as encoded in the concentration-mass relation can explain the diverse
rotation curves of spiral galaxies.


title:
Resilience Design Patterns - A Structured Approach to Resilience at
  Extreme Scale (version 1.0)

abstract:
  In this document, we develop a structured approach to the management of HPC
resilience based on the concept of resilience-based design patterns. A design
pattern is a general repeatable solution to a commonly occurring problem. We
identify the commonly occurring problems and solutions used to deal with
faults, errors and failures in HPC systems. The catalog of resilience design
patterns provides designers with reusable design elements. We define a design
framework that enhances our understanding of the important constraints and
opportunities for solutions deployed at various layers of the system stack. The
framework may be used to establish mechanisms and interfaces to coordinate
flexible fault management across hardware and software components. The
framework also enables optimization of the cost-benefit trade-offs among
performance, resilience, and power consumption. The overall goal of this work
is to enable a systematic methodology for the design and evaluation of
resilience technologies in extreme-scale HPC systems that keep scientific
applications running to a correct solution in a timely and cost-efficient
manner in spite of frequent faults, errors, and failures of various types.


title:
Radial Drift of Dust in Protoplanetary Disks: The Evolution of Ice lines
  and Dead zones

abstract:
  We have developed a new model for the astrochemical structure of a viscously
evolving protoplanetary disk that couples an analytic description of the disk's
temperature and density profile, chemical evolution, and an evolving dust
distribution. We compute evolving radial distributions for a range of dust
grain sizes, which depend on coagulation, fragmentation and radial drift
processes. In particular we find that the water ice line plays an important
role in shaping the radial distribution of the maximum grain size because ice
coated grains are significantly less susceptible to fragmentation than their
dry counterparts. This in turn has important effects on disk ionization and
therefore on the location of dead zones. In comparison to a simple constant
gas-to-dust ratio model for the dust as an example, we find that the new model
predicts an outer dead zone edge that moves in by a factor of about 3 at 1 Myr
(to 5 AU) and by a factor of about 14 by 3 Myr (to 0.5 AU). We show that the
changing position of the dead zone and heat transition traps have important
implications for the formation and trapping of planets in protoplanetary disks.
Finally, we consider our results in light of recent ALMA observations of HL Tau
and TW Hya.


title:
Precise measurement of the $K_{e2}/K_{{\mu}2}$ branching ratio and
  search for new physics beyond the Standard Model

abstract:
  The E36 experiment recently conducted at J-PARC by the TREK Collaboration
will provide a precise mesurement of the decay ratio $ R_K = \Gamma(K^+
\rightarrow e^+\nu_e) / \Gamma(K^+ \rightarrow \mu^+\nu_{\mu}) $ with the aim
of testing lepton universality, a basic assumption of the Standard Model (SM).
The SM prediction for the decay ratio $R_K$ is highly precise ($\delta R_K /
R_K = 4 \times 10^{-4}$) and any observed deviation from this prediction would
clearly indicate the existence of new physics. The E36 experimental apparatus,
designed to offer small systematic errors, was installed at the J-PARC K1.1BR
kaon beam line in the fall of 2014, fully commissioned in the spring of 2015,
and the production data were collected in the fall of 2015. A scintillating
fiber target was used to stop a beam of $1.2 \times 10^6 K^+$ per spill. The
$K^+$ decay products were then momentum analyzed by a 12-sector superconducting
toroidal spectrometer and charged particles were tracked with high precision by
Multi-Wire Proportional Chambers (MWPC) combined with a photon calorimeter with
a large solid angle ($75\%$ of $4\pi$) and 3 different particle identification
systems. Details of the E36 experimental apparatus, as well as the status of
the data analysis will be presented.


title:
A Proposal for measuring Anisotropic Shear Viscosity in Unitary Fermi
  Gases

abstract:
  We present a proposal to measure anisotropic shear viscosity in a strongly
interacting, ultra-cold, unitary Fermi gas confined in a harmonic trap. We
introduce anisotropy in this setup by strongly confining the gas in one of the
directions with relatively weak confinement in the remaining directions. This
system has a close resemblance to anisotropic strongly coupled field theories
studied recently in the context of gauge-gravity duality. Computations in such
theories (which have gravity duals) revealed that some of the viscosity
components of the anisotropic shear viscosity tensor can be made much smaller
than the entropy density, thus parametrically violating the bound proposed by
Kovtun, Son and Starinets (KSS): $\frac {\eta} {s} \geq \frac{1}{4 \pi}$. A
Boltzmann analysis performed in a system of weakly interacting particles in a
linear potential also shows that components of the viscosity tensor can be
reduced. Motivated by these exciting results, we propose two hydrodynamic modes
in the unitary Fermi gas whose damping is governed by the component of shear
viscosity expected to violate the KSS bound. One of these modes is the well
known scissor mode. We estimate trap parameters for which the reduction in the
shear viscosity is of order unity and find that the trap geometry, the damping
timescales, and mode amplitudes are within the range of existing experimental
setups on ultra-cold Fermi gases.


title: Unit circle MVDR beamformer

abstract:
  The array polynomial is the z-transform of the array weights for a narrowband
planewave beamformer using a uniform linear array (ULA). Evaluating the array
polynomial on the unit circle in the complex plane yields the beampattern. The
locations of the polynomial zeros on the unit circle indicate the nulls of the
beampattern. For planewave signals measured with a ULA, the locations of the
ensemble MVDR polynomial zeros are constrained on the unit circle. However,
sample matrix inversion (SMI) MVDR polynomial zeros generally do not fall on
the unit circle. The proposed unit circle MVDR (UC MVDR) projects the zeros of
the SMI MVDR polynomial radially on the unit circle. This satisfies the
constraint on the zeros of ensemble MVDR polynomial. Numerical simulations show
that the UC MVDR beamformer suppresses interferers better than the SMI MVDR and
the diagonal loaded MVDR beamformer and also improves the white noise gain
(WNG).


title: Ballistic quantum transport through Ge/Si core/shell nanowires

abstract:
  We study ballistic hole transport through Ge/Si core/shell nanowires at low
temperatures. We observe Fabry-P$\acute{e}$rot interference patterns as well as
conductance plateaus at integer multiples of 2e$^2$/h at zero magnetic field.
Magnetic field evolution of these plateaus reveals large effective
Land$\acute{e}$ g-factors. Ballistic effects are observed in nanowires with
silicon shell thicknesses of 1 - 3 nm, but not in bare germanium wires. These
findings inform the future development of spin and topological quantum devices
which rely on ballistic subband-resolved transport.


title:
Bandwidth Enhancement in Multimode Polymer Waveguides Using Waveguide
  Layout for Optical Printed Circuit Boards

abstract:
  Dispersion studies demonstrate that waveguide layout can be used to enhance
the bandwidth performance of multimode polymer waveguides for use in
board-level optical interconnects, providing >40 GHzxm without the need for any
launch conditioning.


title: 3D shaping of electron beams using amplitude masks

abstract:
  Shaping the electron wavefunction in three dimensions may prove to be an
indispensable tool for research involving atomic-sized particle trapping,
manipulation, and synthesis. We utilize computer-generated holograms to sculpt
electron wavefunctions in a standard transmission electron microscope in 3D,
and demonstrate the formation of electron beams exhibiting high intensity along
specific trajectories as well as shaping the beam into a 3D lattice of
hot-spots. The concepts presented here are similar to those used in light
optics for trapping and tweezing of particles, but at atomic scale resolutions.


title:
A Three State NDI Switch: Integration of Pendant Redox Unit for
  Conductance Tuning

abstract:
  We studied charge transport phenomena through a core substituted
naphthalenediimide (NDI) single-molecule junctions using the electrochemical
STM-based break junction technique in combination with DFT calculations. The
conductance switch among three well-defined states is acquired by
electrochemically controlling the redox state of the pendent diimide unit of
the molecule in ionic liquid, and the conductance difference is more than one
order of magnitude between di-anion states and neutral state. The potential
dependent charge transport characteristics of the NDI molecules are confirmed
by DFT calculations accounting for electrochemical double-layer effects on the
conductance of the NDI junctions. This work suggests that the integration of
redox unit in the pendent position with strong coupling to molecular backbone
can significantly tune the charge transport of the single-molecule device by
controlling different redox states.


title:
Single-photon detectors combining ultra-high efficiency,
  detection-rates, and timing resolution

abstract:
  Single-photon detection with high efficiency, high timing resolution, low
dark counts and high photon detection-rates is crucial for a wide range of
optical measurements. Although efficient detectors have been reported before,
combining all performance parameters in a single device remains a challenge.
Here, we show a broadband NbTiN superconducting nanowire detector with an
efficiency exceeding 92%, over 150MHz photon detection-rate, a dark count-rate
below 130Hz, operated in a Gifford-McMahon cryostat. Furthermore, with careful
optimization of the detector design and readout electronics, we reach an
ultra-low system timing jitter of 14.80ps (13.95ps decoupled) while maintaining
high detection efficiencies.

categories: physics.ins-det cond-mat.mes-hall physics.optics quant-ph


title:
On the structure of Selmer groups of $p$-ordinary modular forms over
  $\mathbf{Z}_p$-extensions

abstract:
  We prove analogues of the major algebraic results of Greenberg-Vatsal for
Selmer groups of $p$-ordinary newforms over $\mathbf{Z}_p$-extensions which may
be neither cyclotomic nor anticyclotomic, under a number of technical
hypotheses, including a cotorsion assumption on the Selmer groups. The main
complication which arises in our work is the possible presence of finite primes
which can split completely in the $\mathbf{Z}_p$-extension being considered,
resulting in the local cohomology groups that appear in the definition of the
Selmer groups being significantly larger than they are in the case of a
finitely decomposed prime. We give a careful analysis of the $\Lambda$-module
structure of these local cohomology groups and identify the relevant finiteness
condition one must impose to make the proof of the key cohomological
surjectivity result used by Greenberg-Vatsal work in our more general setting.


title: Unoriented 3d TFTs

abstract:
  This paper generalizes two facts about oriented 3d TFTs to the unoriented
case. On one hand, it is known that oriented 3d TFTs having a topological
boundary condition admit a state-sum construction known as the Turaev-Viro
construction. This is related to the string-net construction of fermionic
phases of matter. We show how Turaev-Viro construction can be generalized to
unoriented 3d TFTs. On the other hand, it is known that the "fermionic"
versions of oriented TFTs, known as Spin-TFTs, can be constructed in terms of
"shadow" TFTs which are ordinary oriented TFTs with an anomalous $\mathbb{Z}_2$
1-form symmetry. We generalize this correspondence to Pin$^+$-TFTs by showing
that they can be constructed in terms of ordinary unoriented TFTs with
anomalous $\mathbb{Z}_2$ 1-form symmetry having a mixed anomaly with
time-reversal symmetry. The corresponding Pin$^+$-TFT does not have any anomaly
for time-reversal symmetry however and hence it can be unambiguously defined on
a non-orientable manifold. In case a Pin$^+$-TFT admits a topological boundary
condition, one can combine the above two statements to obtain a
Turaev-Viro-like construction of Pin$^+$-TFTs. As an application of these
ideas, we construct a large class of Pin$^+$-SPT phases.


title:
Characterization of Vegetation and Soil Scattering Mechanisms across
  Different Biomes using P-band SAR Polarimetry

abstract:
  Understanding the scattering mechanisms from the ground surface in the
presence of different vegetation densities is necessary for the interpretation
of P-band Synthetic Aperture Radar (SAR) observations and for the design of
geophysical retrieval algorithms. In this study, a quantitative analysis of
vegetation and soil scattering mechanisms estimated from the observations of an
airborne P-band SAR instrument across nine different biomes in North America is
presented. The goal is to apply a hybrid (model- and eigen- based) three
component decomposition approach to separate the contributions of surface,
double-bounce and vegetation volume scattering across a wide range of biome
conditions. The decomposition makes no prior assumptions about vegetation
structure. We characterize the dynamics of the decomposition across different
North American biomes and assess their characteristic range. Impacts of
vegetation cover seasonality and soil surface roughness on the contributions of
each scattering mechanism are also investigated. Observations used here are
part of the NASA Airborne Microwave Observatory of Subcanopy and Subsurface
(AirMOSS) mission and data have been collected between 2013 and 2015.


title:
Robust Cardiac Motion Estimation using Ultrafast Ultrasound Data: A
  Low-Rank-Topology-Preserving Approach

abstract:
  Cardiac motion estimation is an important diagnostic tool to detect heart
diseases and it has been explored with modalities such as MRI and conventional
ultrasound (US) sequences. US cardiac motion estimation still presents
challenges because of the complex motion patterns and the presence of noise. In
this work, we propose a novel approach to estimate the cardiac motion using
ultrafast ultrasound data. -- Our solution is based on a variational
formulation characterized by the L2-regularized class. The displacement is
represented by a lattice of b-splines and we ensure robustness by applying a
maximum likelihood type estimator. While this is an important part of our
solution, the main highlight of this paper is to combine a low-rank data
representation with topology preservation. Low-rank data representation
(achieved by finding the k-dominant singular values of a Casorati Matrix
arranged from the data sequence) speeds up the global solution and achieves
noise reduction. On the other hand, topology preservation (achieved by
monitoring the Jacobian determinant) allows to radically rule out distortions
while carefully controlling the size of allowed expansions and contractions.
Our variational approach is carried out on a realistic dataset as well as on a
simulated one. We demonstrate how our proposed variational solution deals with
complex deformations through careful numerical experiments. While maintaining
the accuracy of the solution, the low-rank preprocessing is shown to speed up
the convergence of the variational problem. Beyond cardiac motion estimation,
our approach is promising for the analysis of other organs that experience
motion.


title: Variational Lossy Autoencoder

abstract:
  Representation learning seeks to expose certain aspects of observed data in a
learned representation that's amenable to downstream tasks like classification.
For instance, a good representation for 2D images might be one that describes
only global structure and discards information about detailed texture. In this
paper, we present a simple but principled method to learn such global
representations by combining Variational Autoencoder (VAE) with neural
autoregressive models such as RNN, MADE and PixelRNN/CNN. Our proposed VAE
model allows us to have control over what the global latent code can learn and
, by designing the architecture accordingly, we can force the global latent
code to discard irrelevant information such as texture in 2D images, and hence
the VAE only "autoencodes" data in a lossy fashion. In addition, by leveraging
autoregressive models as both prior distribution $p(z)$ and decoding
distribution $p(x|z)$, we can greatly improve generative modeling performance
of VAEs, achieving new state-of-the-art results on MNIST, OMNIGLOT and
Caltech-101 Silhouettes density estimation tasks.


title:
Existence of superconducting solutions for a reduced Ginzburg-Landau
  model in the presence of strong electric currents

abstract:
  In this work we consider a reduced Ginzburg-Landau model in which the
magnetic field is neglected and the magnitude of the current density is
significantly stronger than that considered in a recent work by the same
authors. We prove the existence of a solution which can be obtained by solving
a non-convex minimization problem away from the boundary of the domain. Near
the boundary, we show that this solution is essentially one-dimensional. We
also establish some linear stability results for a simplified, one-dimensional
version of the original problem.


title:
Minimum node degree in inhomogeneous random key graphs with unreliable
  links

abstract:
  We consider wireless sensor networks under a heterogeneous random key
predistribution scheme and an on-off channel model. The heterogeneous key
predistribution scheme has recently been introduced by Ya\u{g}an - as an
extension to the Eschenauer and Gligor scheme - for the cases when the network
consists of sensor nodes with varying level of resources and/or connectivity
requirements, e.g., regular nodes vs. cluster heads. The network is modeled by
the intersection of the inhomogeneous random key graph (induced by the
heterogeneous scheme) with an Erd\H{o}s-R\'enyi graph (induced by the on/off
channel model). We present conditions (in the form of zero-one laws) on how to
scale the parameters of the intersection model so that with high probability
all of its nodes are connected to at least $k$ other nodes; i.e., the minimum
node degree of the graph is no less than $k$. We also present numerical results
to support our results in the finite-node regime. The numerical results suggest
that the conditions that ensure $k$-connectivity coincide with those ensuring
the minimum node degree being no less than $k$.


title:
Globular Cluster Abundances from High-Resolution, Integrated-Light
  Spectroscopy. II. Expanding the Metallicity Range for Old Clusters and
  Updated Analysis Techniques

abstract:
  We present abundances of globular clusters in the Milky Way and Fornax from
integrated light spectra. Our goal is to evaluate the consistency of the
integrated light analysis relative to standard abundance analysis for
individual stars in those same clusters. This sample includes an updated
analysis of 7 clusters from our previous publications and results for 5 new
clusters that expand the metallicity range over which our technique has been
tested. We find that the [Fe/H] measured from integrated light spectra agrees
to $\sim$0.1 dex for globular clusters with metallicities as high as
[Fe/H]=$-0.3$, but the abundances measured for more metal rich clusters may be
underestimated. In addition we systematically evaluate the accuracy of
abundance ratios, [X/Fe], for Na I, Mg I, Al I, Si I, Ca I, Ti I, Ti II, Sc II,
V I, Cr I, Mn I, Co I, Ni I, Cu I, Y II, Zr I, Ba II, La II, Nd II, and Eu II.
The elements for which the integrated light analysis gives results that are
most similar to analysis of individual stellar spectra are Fe I, Ca I, Si I, Ni
I, and Ba II. The elements that show the greatest differences include Mg I and
Zr I. Some elements show good agreement only over a limited range in
metallicity. More stellar abundance data in these clusters would enable more
complete evaluation of the integrated light results for other important
elements.


title: Low pH, high salinity: too much for Microbial Fuel Cells?

abstract:
  Twelve single chambered, air-cathode Tubular Microbial Fuel Cells (TMFCs)
have been filled up with fruit and vegetable residues. The anodes were realized
by means of a carbon fiber brush, while the cathodes were realized through a
graphite-based porous ceramic disk with Nafion membranes (117 Dupont). The
performances in terms of polarization curves and power production were assessed
according to different operating conditions: percentage of solid substrate
water dilution, adoption of freshwater and a 35mg/L NaCl water solution and,
finally, the effect of an initial potentiostatic growth.
  All TMFCs operated at low pH (pH$=3.0 \pm 0.5$), as no pH amendment was
carried out. Despite the harsh environmental conditions, our TMFCs showed a
Power Density (PD) ranging from 20 to 55~mW/m$^2 \cdot$kg$_{\text{waste}}$ and
a maximum CD of 20~mA/m$^2 \cdot$kg$_{\text{waste}}$, referred to the cathodic
surface. COD removal after a $28-$day period was about $45 \%$.
  The remarkably low pH values as well as the fouling of Nafion membrane very
likely limited TMFC performances. However, a scale-up estimation of our
reactors provides interesting values in terms of power production, compared to
actual anaerobic digestion plants. These results encourage further studies to
characterize the graphite-based porous ceramic cathodes and to optimize the
global TMFC performances, as they may provide a valid and sustainable
alternative to anaerobic digestion technologies.


title: Non-conservative Forces via Quantum Reservoir Engineering

abstract:
  A systematic approach is given for engineering dissipative environments that
steer quantum wavepackets along desired trajectories. The methodology is
demonstrated with several illustrative examples: environment-assisted
tunneling, trapping, effective mass assignment, and pseudo-relativistic
behavior. Non-conservative stochastic forces do not inevitably lead to
decoherence - we show that purity can be well-preserved. These findings
highlight the flexibility offered by non-equilibrium open quantum dynamics.


title: Efficient Discovery of Ontology Functional Dependencies

abstract:
  Poor data quality has become a pervasive issue due to the increasing
complexity and size of modern datasets. Constraint based data cleaning
techniques rely on integrity constraints as a benchmark to identify and correct
errors. Data values that do not satisfy the given set of constraints are
flagged as dirty, and data updates are made to re-align the data and the
constraints. However, many errors often require user input to resolve due to
domain expertise defining specific terminology and relationships. For example,
in pharmaceuticals, 'Advil' \emph{is-a} brand name for 'ibuprofen' that can be
captured in a pharmaceutical ontology. While functional dependencies (FDs) have
traditionally been used in existing data cleaning solutions to model syntactic
equivalence, they are not able to model broader relationships (e.g., is-a)
defined by an ontology. In this paper, we take a first step towards extending
the set of data quality constraints used in data cleaning by defining and
discovering \emph{Ontology Functional Dependencies} (OFDs). We lay out
theoretical and practical foundations for OFDs, including a set of sound and
complete axioms, and a linear inference procedure. We then develop effective
algorithms for discovering OFDs, and a set of optimizations that efficiently
prune the search space. Our experimental evaluation using real data show the
scalability and accuracy of our algorithms.


title:
The Meaning of the Wave Function: In Search of the Ontology of Quantum
  Mechanics

abstract:
  The meaning of the wave function has been a hot topic of debate since the
early days of quantum mechanics. Recent years have witnessed a growing interest
in this long-standing question. Is the wave function ontic, directly
representing a state of reality, or epistemic, merely representing a state of
(incomplete) knowledge, or something else? If the wave function is not ontic,
then what, if any, is the underlying state of reality? If the wave function is
indeed ontic, then exactly what physical state does it represent? In this book,
I aim to make sense of the wave function in quantum mechanics and find the
ontological content of the theory. The book can be divided into three parts.
The first part addresses the question of the nature of the wave function
(Chapters 1-5). After giving a comprehensive and critical review of the
competing views of the wave function, I present a new argument for the ontic
view in terms of protective measurements. In addition, I also analyze the
origin of the wave function by deriving the free Schroedinger equation. The
second part analyzes the ontological meaning of the wave function (Chapters 6,
7). I propose a new ontological interpretation of the wave function in terms of
random discontinuous motion of particles, and give two main arguments
supporting this interpretation. The third part investigates whether the
suggested quantum ontology is complete in accounting for our definite
experience and whether it needs to be revised in the relativistic domain
(Chapters 8, 9).


title:
Recursive Regression with Neural Networks: Approximating the HJI PDE
  Solution

abstract:
  The majority of methods used to compute approximations to the
Hamilton-Jacobi-Isaacs partial differential equation (HJI PDE) rely on the
discretization of the state space to perform dynamic programming updates. This
type of approach is known to suffer from the curse of dimensionality due to the
exponential growth in grid points with the state dimension. In this work we
present an approximate dynamic programming algorithm that computes an
approximation of the solution of the HJI PDE by alternating between solving a
regression problem and solving a minimax problem using a feedforward neural
network as the function approximator. We find that this method requires less
memory to run and to store the approximation than traditional gridding methods,
and we test it on a few systems of two, three and six dimensions.


title:
Wild oscillations in a nonlinear neuron model with resets: (I) Bursting,
  spike adding and chaos

abstract:
  In a series of two papers, we investigate the mechanisms by which complex
oscillations are generated in a class of nonlinear dynamical systems with
resets modeling the voltage and adaptation of neurons. This first paper
presents mathematical analysis showing that the system can support bursts of
any period as a function of model parameters. In continuous dynamical systems
with resets, period-incrementing structures are complex to analyze. In the
present context, we use the fact that bursting patterns correspond to periodic
orbits of the adaptation map that governs the sequence of values of the
adaptation variable at the resets. Using a slow-fast approach, we show that
this map converges towards a piecewise linear discontinuous map whose orbits
are exactly characterized. That map shows a period-incrementing structure with
instantaneous transitions. We show that the period-incrementing structure
persists for the full system with non-constant adaptation, but the transitions
are more complex. We investigate the presence of chaos at the transitions.


title:
Quadratic Weighted Geometric Mean in Hermitian Unital Banach
  Star-Algebras

abstract:
  In this paper we introduce the quadratic weighted geometric mean for
invertible elements x, y in a Hermitian unital Banach star-algebra and provide
some inequalities for this mean under various assumptions for the elements
involved.


title:
Unconventional fractional quantum Hall states and Wigner crystallization
  in suspended Corbino graphene

abstract:
  Competition between liquid and solid states in two-dimensional electron
system is an intriguing problem in condensed matter physics. We have
investigated competing Wigner crystal and fractional quantum Hall ( FQH )
liquid phases in atomically thin suspended graphene devices in Corbino
geometry. Low temperature magnetoconductance and transconductance measurements
along with $IV$ characteristics all indicate strong charge density dependent
modulation of electron transport. Our results show unconventional FQH phases
which do not fit the standard Jain's series for conventional FQH states,
instead they appear to originate from residual interactions of composite
fermions in partially filled higher Landau levels. And at very low charge
density with filling factors $\nu \lesssim$ 1/5, electrons crystallize into an
ordered Wigner solid which eventually transforms into an incompressible Hall
liquid at filling factors around $\nu \leq$ 1/7. Building on the unique sample
structure, our experiments pave the way for enhanced understanding of the
ordered phases of interacting electrons.


title: Points with finite orbits for trace maps

abstract:
  We study an action of ${\rm Aut}(F_n)$ on $\mathbb{R}^{2^n-1}$ by trace maps,
defined using the traces of $n$-tuples of matrices in
$\mathrm{SL}(2,\mathbb{C})$ having real traces.
  We determine the finite orbits for this action. These orbits essentially come
from (i) the finite subgroups of $\mathrm{SL}(2,\mathbb C)$, and (ii) a dense
set of (rational) points in an embedded quotient of an $n$-torus.


title:
Asymmetric pentagonal metal meshes for flexible transparent electrodes
  and heaters

abstract:
  Metal meshes have emerged as an important class of flexible transparent
electrodes. We report on the characteristics of a new class of asymmetric
meshes, tiled using a recently-discovered family of pentagons. Micron-scale
meshes were fabricated on flexible polyethylene terephthalate substrates via
optical lithography, metal evaporation (Ti 10 nm, Pt 50 nm) and lift-off. Three
different designs were assessed, each with the same tessellation pattern and
linewidth (5 micron), but with different sizes of the fundamental pentagonal
unit. The designs corresponded to areal coverage of the metal patterns of 27%
(Design#1), 14% (Design#2) and 9% (Design#3), respectively. Good mechanical
stability was observed for both tensile strain and compressive strain. After
1,000 bending cycles, devices subjected to tensile strain showed fractional
resistance increases in the range 8% to 17% with the lowest changes observed
for Design#2. Devices subjected to compressive strain showed fractional
resistance increases in the range 0% to 7% with best results observed for
Design#1. The performance of the pentagonal metal mesh devices as visible
transparent heaters via Joule heating was also assessed. A saturation
temperature of 88 +/- 1 degrees C was achieved at low voltage (5 V) with a fast
response time (~ 20 s) and a high thermal resistance (168 +/- 6 degrees C
cm2/W). Finally, de-icing was successfully demonstrated (45 s at 5 V) for an
ice layer on a glass coupon placed on top of the PET substrate.


title:
Fermi-edge singularity and related interaction induced phenomena in
  multilevel quantum dots

abstract:
  We study the manifestation of the non-perturbative effects of interaction in
sequential tunnelling between a quasi-one dimensional system of chiral quantum
Hall edge channels and a multilevel quantum dot (QD). We use the formal
scattering theory approach to the bosonization technique to present an
alternative derivation of the Fermi-edge singularity (FES) effect and
demonstrate the origin of its universality. This approach allows us to address,
within the same framework, plasmon assisted sequential tunnelling to relatively
large dots and investigate the interaction induced level broadening. The
results are generalised by taking into account the dispersion in the spectrum
of plasmons in the QD. We then discuss their modification in the presence of
neutral modes, which can be realised either in a QD with two chiral strongly
interacting edge channels or in a three dimensional QD in the Coulomb blockade
regime. In the former case a universal behaviour of the tunnelling rate is
discovered.


title: The $\alpha$-representation for the characteristic function of a matroid

abstract:
  Let $M=(E,\mathcal B)$ be an $\mathbb F_q$-linear matroid; denote by
${\mathcal B}$ the family of its bases, $s(M;\alpha)=\sum_{B\in\mathcal
B}\prod_{e \in B} \alpha_e$, where ${\alpha_e\in \mathbb F_q}$. According to
the Kontsevich conjecture stated in 1997, the number of nonzero values of
$s(M;\alpha)$ is a polynomial with respect to $q$ for all matroids. This
conjecture was disproved by P. Brosnan and P. Belkale. In this paper we express
the characteristic polynomial of the dual matroid $M^\perp$ in terms of the
"correct" Kontsevich formula (for $\mathbb F_q$-linear matroids). This
representation generalizes the formula for a flow polynomial of a graph which
was obtained by us earlier (and with the help of another technique). In
addition, generalizing the correlation (announced by us earlier) that connects
flow and chromatic polynomials, we define the characteristic polynomial of
$M^\perp$ in two ways, namely, in terms of characteristic polynomials of $M/A$
and $M|_A$, respectively, $A\subseteq E$. The latter expressions are close to
convolution-multiplication formulas established by V. Reiner and J. P. S. Kung.


title: Eddy diffusivities of inertial particles in random Gaussian flows

abstract:
  We investigate the large-scale transport of inertial particles. We derive
explicit analytic expressions for the eddy diffusivities for generic Stokes
times. These latter expressions are exact for any shear flow while they
correspond to the leading contribution either in the deviation from the shear
flow geometry or in the P\'eclet number of general random Gaussian velocity
fields. Our explicit expressions allow us to investigate the role of inertia
for such a class of flows and to make exact links with the analogous transport
problem for tracer particles.


title: Absence of long wavelength nematic fluctuations in LiFeAs

abstract:
  We investigated long-wavelength nematic fluctuations in an Fe-based
superconductor LiFeAs near q=(0.05,0,0) by measuring temperature-dependent
renormalization of acoustic phonons through inelastic neutron scattering. We
found that the phonons have conventional behavior, as would be expected in the
absence of electronic nematic fluctuations. This observation implies that
either electron-phonon coupling is too weak to see any effect or that nematic
fluctuations are not present.


title:
Next-to-Next-to-Leading Order $N$-Jettiness Soft Function for One
  Massive Colored Particle Production at Hadron Colliders

abstract:
  The $N$-jettiness subtraction has proven to be an efficient method to perform
differential QCD next-to-next-to-leading order (NNLO) calculations in the last
few years. One important ingredient of this method is the NNLO soft function.
We calculate this soft function for one massive colored particle production at
hadron colliders. We select the color octet and color triplet cases to present
the final results. We also discuss its application in NLO and NNLO differential
calculations.


title:
CALIS - a CALibration Insertion System for the DarkSide-50 dark matter
  search experiment

abstract:
  This paper describes the design, fabrication, commissioning and use of a
CALibration source Insertion System (CALIS) in the DarkSide-50 direct dark
matter search experiment. CALIS deploys radioactive sources into the liquid
scintillator veto to characterize the detector response and detection
efficiency of the DarkSide-50 Liquid Argon Time Projection Chamber, and the
surrounding 30 t organic liquid scintillator neutron veto. It was commissioned
in September 2014 and has been used successfully in several gamma and neutron
source campaigns since then. A description of the hardware and an excerpt of
calibration analysis results are given below.


title:
The effect of inclusion of $\Delta$ resonances in relativistic
  mean-field model with scaled hadron masses and coupling constants

abstract:
  Knowledge of the equation of state of the baryon matter plays a decisive role
in the description of neutron stars. With an increase of the baryon density the
filling of Fermi seas of hyperons and $\Delta$ isobars becomes possible. Their
inclusion into standard relativistic mean-field models results in a strong
softening of the equation of state and a lowering of the maximum neutron star
mass below the measured values. We extend a relativistic mean-field model with
scaled hadron masses and coupling constants developed in our previous works and
take into account now not only hyperons but also the $\Delta$ isobars. We
analyze available empirical information to put constraints on coupling
constants of $\Delta$s to mesonic mean fields. We show that the resulting
equation of state satisfies majority of presently known experimental
constraints.


title: Row Cones, Perron Similarities, and Nonnegative Spectra

abstract:
  In further pursuit of the diagonalizable \emph{real nonnegative inverse
eigenvalue problem} (RNIEP), we study the relationship between the \emph{row
cone} $\mathcal{C}_r(S)$ and the \emph{spectracone} $\mathcal{C}(S)$ of a
Perron similarity $S$. In the process, a new kind of matrix, \emph{row Hadamard
conic} (RHC), is defined and related to the D-RNIEP. Characterizations are
given when $\mathcal{C}_r(S) = \mathcal{C}(S)$, and explicit examples are given
for all possible set-theoretic relationships between the two cones. The
symmetric NIEP is the special case of the D-RNIEP in which the Perron
similarity $S$ is also orthogonal.


title:
Peak-height formula for higher-order breathers of the nonlinear
  Schr\"odinger equation on non-uniform backgrounds

abstract:
  Given any background (or seed) solution of the nonlinear Schr\"odinger
equation, the Darboux transformation can be used to generate higher-order
breathers with much greater peak intensities. The Darboux transformation is
generic in iterating a pair of generating solutions of the Lax-pair equation
which preserves the solution of the nonlinear Schr\"odinger equation as a
consistency condition. The Darboux transformation itself knows nothing about
the background solution except through the initial pair of Lax solutions.
Because of this, in this work, we can prove in an unified manner, and without
knowing the analytical form of the background solution, that the peak-height of
a high-order breather, is just a sum of peak-heights of first-order breathers
plus that of the background, {\it irrespective} of the specific choice of the
background. Detailed results are verified for breathers on a cnoidal
background. Generalizations to more extended nonlinear Schr\"odinger equations
are also indicated.


title: Gradient-informed basis adaptation for Legendre Chaos expansions

abstract:
  The recently introduced basis adaptation method for Homogeneous (Wiener)
Chaos expansions is explored in a new context where the rotation/projection
matrices are computed by discovering the active subspace where the random input
exhibits most of its variability. In the case where a 1-dimensional active
subspace exists, the methodology can be applicable to generalized Polynomial
Chaos expansions, thus enabling the projection of a high dimensional input to a
single input variable and the efficient estimation of a univariate chaos
expansion. Attractive features of this approach, such as the significant
computational savings and the high accuracy in computing statistics of interest
are investigated.


title: Recursive Decomposition for Nonconvex Optimization

abstract:
  Continuous optimization is an important problem in many areas of AI,
including vision, robotics, probabilistic inference, and machine learning.
Unfortunately, most real-world optimization problems are nonconvex, causing
standard convex techniques to find only local optima, even with extensions like
random restarts and simulated annealing. We observe that, in many cases, the
local modes of the objective function have combinatorial structure, and thus
ideas from combinatorial optimization can be brought to bear. Based on this, we
propose a problem-decomposition approach to nonconvex optimization. Similarly
to DPLL-style SAT solvers and recursive conditioning in probabilistic
inference, our algorithm, RDIS, recursively sets variables so as to simplify
and decompose the objective function into approximately independent
sub-functions, until the remaining functions are simple enough to be optimized
by standard techniques like gradient descent. The variables to set are chosen
by graph partitioning, ensuring decomposition whenever possible. We show
analytically that RDIS can solve a broad class of nonconvex optimization
problems exponentially faster than gradient descent with random restarts.
Experimentally, RDIS outperforms standard techniques on problems like structure
from motion and protein folding.


title: Peeling Bipartite Networks for Dense Subgraph Discovery

abstract:
  Finding dense bipartite subgraphs and detecting the relations among them is
an important problem for affiliation networks that arise in a range of domains,
such as social network analysis, word-document clustering, the science of
science, internet advertising, and bioinformatics. However, most dense subgraph
discovery algorithms are designed for classic, unipartite graphs. Subsequently,
studies on affiliation networks are conducted on the co-occurrence graphs
(e.g., co-author and co-purchase) that project the bipartite structure to a
unipartite structure by connecting two entities if they share an affiliation.
Despite their convenience, co-occurrence networks come at a cost of loss of
information and an explosion in graph sizes, which limit the quality and the
efficiency of solutions. We study the dense subgraph discovery problem on
bipartite graphs. We define a framework of bipartite subgraphs based on the
butterfly motif (2,2-biclique) to model the dense regions in a hierarchical
structure. We introduce efficient peeling algorithms to find the dense
subgraphs and build relations among them. We can identify denser structures
compared to the state-of-the-art algorithms on co-occurrence graphs in
real-world data. Our analyses on an author-paper network and a user-product
network yield interesting subgraphs and hierarchical relations such as the
groups of collaborators in the same institution and spammers that give fake
ratings.


title: Integer Lattice Dynamics for Vlasov-Poisson

abstract:
  We revisit the integer lattice (IL) method to numerically solve the
Vlasov-Poisson equations, and show that a slight variant of the method is a
very easy, viable, and efficient numerical approach to study the dynamics of
self-gravitating, collisionless systems. The distribution function lives in a
discretized lattice phase-space, and each time-step in the simulation
corresponds to a simple permutation of the lattice sites. Hence, the method is
Lagrangian, conservative, and fully time-reversible. IL complements other
existing methods, such as N-body/particle mesh (computationally efficient, but
affected by Monte-Carlo sampling noise and two-body relaxation) and finite
volume (FV) direct integration schemes (expensive, accurate but diffusive). We
also present improvements to the FV scheme, using a moving mesh approach
inspired by IL, to reduce numerical diffusion and the time-step criterion.
Being a direct integration scheme like FV, IL is memory limited (memory
requirement for a full 3D problem scales as N^6, where N is the resolution per
linear phase-space dimension). However, we describe a new technique for
achieving N^4 scaling. The method offers promise for investigating the full 6D
phase-space of collisionless systems of stars and dark matter.


title:
ZeroTouch Provisioning (ZTP) Model and Infrastructure Components for
  Multi-provider Cloud Services Provisioning

abstract:
  This paper presents results of the ongoing development of the Cloud Services
Delivery Infrastructure (CSDI) that provides a basis for infrastructure centric
cloud services provisioning, operation and management in multi-cloud
multi-provider environment defined as a Zero Touch Provisioning, Operation and
Management (ZTP/ZTPOM) model. The presented work refers to use cases from data
intensive research that require high performance computation resources and
large storage volumes that are typically distributed between datacenters often
involving multiple cloud providers. Automation for large scale scientific (and
industrial) applications should include provisioning of both inter-cloud
network infrastructure and intra-cloud application resources. It should provide
support for the complete application operation workflow together with the
possible application infrastructure and resources changes that can occur during
the application lifecycle. The authors investigate existing technologies for
automation of the service provisioning and management processes aiming to
cross-pollinate best practices from currently disconnected domains such as
cloud based applications provisioning and multi-domain high-performance network
provisioning. The paper refers to the previous and legacy research by authors,
the Open Cloud eXchange (OCX), that has been proposed to address the last mile
problem in cloud services delivery to campuses over trans-national backbone
networks such as GEANT. OCX will serve as an integral component of the
prospective ZTP infrastructure over the GEANT network. Another important
component, the Marketplace, is defined for providing cloud services and
applications discovery (in generally intercloud environment) and may also
support additional services such as services composition and trust brokering
for establishing customer-provider federations.


title:
Free time evolution of a tracer particle coupled to a Fermi gas in the
  high-density limit

abstract:
  The dynamics of a particle coupled to a dense and homogeneous ideal Fermi gas
in two spatial dimensions is studied. We analyze the model for coupling
parameter g=1 (i.e., not in the weak coupling regime), and prove closeness of
the time evolution to an effective dynamics for large densities of the gas and
for long time scales of the order of some power of the density. The effective
dynamics is generated by the free Hamiltonian with a large but constant energy
shift which is given at leading order by the spatially homogeneous mean field
potential of the gas particles. Here, the mean field approximation turns out to
be accurate although the fluctuations of the potential around its mean value
can be arbitrarily large. Our result is in contrast to a dense bosonic gas in
which the free motion of a tracer particle would be disturbed already on a very
short time scale. The proof is based on the use of strong phase cancellations
in the deviations of the microscopic dynamics from the mean field time
evolution.

categories: math-ph cond-mat.quant-gas math.MP quant-ph


title: The missing assets and the size of Shadow Banking: an update

abstract:
  In a recent paper, using data from Forbes Global 2000, we have observed that
the upper tail of the firm size distribution (by assets) falls off much faster
than a Pareto distribution. The missing mass was suggested as an indicator of
the size of the Shadow Banking (SB) sector. This short note provides the latest
figures of the missing assets for 2013, 2014 and 2015. In 2013 and 2014 the
dynamics of the missing assets continued being strongly correlated with
estimates of the size of the SB sector of the Financial Stability Board. In
2015 we find a sharp decrease in the size of missing assets, suggesting that
the SB sector is deflating.


title:
Andreev bound states formation and quasiparticle trapping in quench
  dynamics revealed by time-dependent counting statistics

abstract:
  We analyze the quantum quench dynamics in the formation of a phase-biased
superconducting nanojunction. We find that in the absence of an external
relaxation mechanism and for very general conditions the system gets trapped in
a metastable state, corresponding to a non-equilibrium population of the
Andreev bound states. The use of the time-dependent Full Counting Statistics
(FCS) analysis allows us to extract information on the asymptotic population of
even and odd manybody states, demonstrating that a universal behavior,
dependent only on the Andreev states energy, is reached in the quantum point
contact limit. These results shed light on recent experimental observations on
quasiparticle trapping in superconducting atomic contacts.


title: Generalized Cluster Trees and Singular Measures

abstract:
  In this paper, we study the $\alpha$-cluster tree ($\alpha$-tree) under both
singular and nonsingular measures. The $\alpha$-tree uses probability contents
within a level set to construct a cluster tree so that it is well-defined for
singular measures. We first derive the convergence rate for a density level set
around critical points, which leads to the convergence rate for estimating an
$\alpha$-tree under nonsingular measures. For singular measures, we study how
the kernel density estimator (KDE) behaves and prove that the KDE is not
uniformly consistent but pointwisely consistent after rescaling. We further
prove that the estimated $\alpha$-tree fails to converge in the $L_\infty$
metric but is still consistent under the integrated distance. We also observe a
new type of critical points--the dimensional critical points (DCPs)--of a
singular measure. DCPs occur only at singular measures, and similar to the
usual critical points, DCPs contribute to cluster tree topology as well.
Building on the analysis of the KDE and DCPs, we prove the topological
consistency of an estimated $\alpha$-tree.


title: The long flow to freedom

abstract:
  Two-dimensional field theories do not have a moduli space of vacua. Instead,
it is common that their low-energy behavior is a sigma model with a target
space. When this target space is compact its renormalization group flow is
standard. When it is non-compact the continuous spectrum of operators can
change the qualitative behavior. Here we discuss two-dimensional gauge theories
with N=(2,2) supersymmetry. We focus on two specific theories, for which we
argue that they flow to free chiral multiplets at low energies: the U(1) gauge
theory with one flavor (two chiral superfields with charges plus and minus one)
and a non-zero Fayet-Iliopoulos term, and pure SU(N) gauge theories. We argue
that the renormalization group flow of these theories has an interesting order
of limits issue. Holding the position on the target space fixed, the space
flattens out under the renormalization group. On the other hand, if we first go
to infinity on the target space and then perform the renormalization group, we
always have a non-trivial space, e.g. a cone with a deficit angle. We explain
how to interpret low-energy dualities between theories with non-compact target
spaces. We expect a similar qualitative behavior also for other non-compact
sigma models, even when they do not flow to free theories.


title:
Inferring low-dimensional microstructure representations using
  convolutional neural networks

abstract:
  We apply recent advances in machine learning and computer vision to a central
problem in materials informatics: The statistical representation of
microstructural images. We use activations in a pre-trained convolutional
neural network to provide a high-dimensional characterization of a set of
synthetic microstructural images. Next, we use manifold learning to obtain a
low-dimensional embedding of this statistical characterization. We show that
the low-dimensional embedding extracts the parameters used to generate the
images. According to a variety of metrics, the convolutional neural network
method yields dramatically better embeddings than the analogous method derived
from two-point correlations alone.


title:
OGLE-2015-BLG-0196: Ground-based Gravitational Microlens Parallax
  Confirmed By Space-Based Observation

abstract:
  In this paper, we present the analysis of the binary gravitational
microlensing event OGLE-2015-BLG-0196. The event lasted for almost a year and
the light curve exhibited significant deviations from the lensing model based
on the rectilinear lens-source relative motion, enabling us to measure the
microlens parallax. The ground-based microlens parallax is confirmed by the
data obtained from space-based microlens observations using the {\it Spitzer}
telescope. By additionally measuring the angular Einstein radius from the
analysis of the resolved caustic crossing, the physical parameters of the lens
are determined up to the two-fold degeneracy: $u_0<0$ and $u_0>0$ solutions
caused by the well-known "ecliptic" degeneracy. It is found that the binary
lens is composed of two M dwarf stars with similar masses $M_1=0.38\pm 0.04\
M_\odot$ ($0.50\pm 0.05\ M_\odot)$ and $M_2=0.38\pm 0.04\ M_\odot$ ($0.55\pm
0.06\ M_\odot$) and the distance to the lens is $D_{\rm L}=2.77\pm 0.23$ kpc
($3.30\pm 0.29$ kpc). Here the physical parameters out and in the parenthesis
are for the $u_0<0$ and $u_0>0$ solutions, respectively.


title: The Integral- and Intermediate-Screened Coupled-Cluster Method

abstract:
  We present the formulation and implementation of the integral- and
intermediate-screened coupled-cluster method (ISSCC). The IISCC method gives a
simple and rigorous integral and intermediate screening (IIS) of the
coupled-cluster method and will significantly reduces the scaling for all
orders of the CC hierarchy exactly like seen for the integral-screened
configuration-interaction method (ISCI). The rigorous IIS in the IISCC gives a
robust and adjustable error control which should allow for the possibility of
converging the energy without any loss of accuracy while retaining low or
linear scaling at the same time. The derivation of the IISCC is performed in a
similar fashion as in the ISCI where we show that the tensor contractions for
the nested commutators are separable up to an overall sign and that this
separability can lead to a rigorous IIS. In the nested commutators the
integrals are screened in the first tensor contraction and the intermediates
are screened in all successive tensor contractions. The rigorous IIS will lead
to linear scaling for all nested commutators for large systems in a similar way
as seen for the ISCI. The reduced scaling can in this way be obtained without
any range dependent parameter for the interaction, unlike other low scaling
methods and is therefore also suitable for charge separated systems. It is
expected that the IISCC, just like the ISCI, can use dramatically larger
orbital spaces combined with large CC expansions as compared with traditional
CC methods. Due to the size extensive nature of the CC method the IISCC should
not only be applicable to few electron systems but also to large molecular
system unlike the ISCI. The IISCC can here either be used as a stand alone
method or combined with other linear scaling approaches like the fragmentation
method or other methods which introduces a range dependent interaction
screening.


title:
A backward pass through a CNN using a generative model of its
  activations

abstract:
  Neural networks have shown to be a practical way of building a very complex
mapping between a pre-specified input space and output space. For example, a
convolutional neural network (CNN) mapping an image into one of a thousand
object labels is approaching human performance in this particular task. However
the mapping (neural network) does not automatically lend itself to other forms
of queries, for example, to detect/reconstruct object instances, to enforce
top-down signal on ambiguous inputs, or to recover object instances from
occlusion. One way to address these queries is a backward pass through the
network that fuses top-down and bottom-up information. In this paper, we show a
way of building such a backward pass by defining a generative model of the
neural network's activations. Approximate inference of the model would
naturally take the form of a backward pass through the CNN layers, and it
addresses the aforementioned queries in a unified framework.


title: Human mobility networks and persistence of rapidly mutating pathogens

abstract:
  Rapidly mutating pathogens may be able to persist in the population and reach
an endemic equilibrium by escaping hosts' acquired immunity. For such diseases,
multiple biological, environmental and population-level mechanisms determine
the dynamics of the outbreak, including pathogen's epidemiological traits (e.g.
transmissibility, infectious period and duration of immunity), seasonality,
interaction with other circulating strains and hosts' mixing and spatial
fragmentation. Here, we study a susceptible-infected-recovered-susceptible
model on a metapopulation where individuals are distributed in subpopulations
connected via a network of mobility flows. Through extensive numerical
simulations, we explore the phase space of pathogen's persistence and map the
dynamical regimes of the pathogen following emergence. Our results show that
spatial fragmentation and mobility play a key role in the persistence of the
disease whose maximum is reached at intermediate mobility values. We describe
the occurrence of different phenomena including local extinction and emergence
of epidemic waves, and assess the conditions for large scale spreading.
Findings are highlighted in reference to previous works and to real scenarios.
Our work uncovers the crucial role of hosts' mobility on the ecological
dynamics of rapidly mutating pathogens, opening the path for further studies on
disease ecology in the presence of a complex and heterogeneous environment.


title:
Creating an Isotopically Similar Earth-Moon System with Correct Angular
  Momentum from a Giant Impact

abstract:
  The giant impact hypothesis is the dominant theory explaining the formation
of our Moon. However, its inability to produce an isotopically similar
Earth-Moon system with correct angular momentum has cast a shadow on its
validity. Computer-generated impacts have been successful in producing virtual
systems that possess many of the physical properties we observe. Yet,
addressing the isotopic similarities between the Earth and Moon coupled with
correct angular momentum has proven to be challenging. Equilibration and
evection resonance have been put forth as a means of reconciling the models.
However, both were rejected in a meeting at The Royal Society in London. The
main concern was that models were multi-staged and too complex. Here, we
present initial impact conditions that produce an Earth-Moon system whose
angular momentum and isotopic properties are correct. The model is
straightforward and the results are a natural consequence of the impact.


title: Delving into Transferable Adversarial Examples and Black-box Attacks

abstract:
  An intriguing property of deep neural networks is the existence of
adversarial examples, which can transfer among different architectures. These
transferable adversarial examples may severely hinder deep neural network-based
applications. Previous works mostly study the transferability using small scale
datasets. In this work, we are the first to conduct an extensive study of the
transferability over large models and a large scale dataset, and we are also
the first to study the transferability of targeted adversarial examples with
their target labels. We study both non-targeted and targeted adversarial
examples, and show that while transferable non-targeted adversarial examples
are easy to find, targeted adversarial examples generated using existing
approaches almost never transfer with their target labels. Therefore, we
propose novel ensemble-based approaches to generating transferable adversarial
examples. Using such approaches, we observe a large proportion of targeted
adversarial examples that are able to transfer with their target labels for the
first time. We also present some geometric studies to help understanding the
transferable adversarial examples. Finally, we show that the adversarial
examples generated using ensemble-based approaches can successfully attack
Clarifai.com, which is a black-box image classification system.


title: Linear chord diagrams with long chords

abstract:
  A linear chord diagram of size $n$ is a partition of the set
$\{1,2,\cdots,2n\}$ into sets of size two, called chords. From a table showing
the number of linear chord diagrams of degree $n$ such that every chord has
length at least $k$, we observe that if we proceed far enough along the
diagonals, they are given by a geometric sequence. We prove that this holds for
all diagonals, and identify when the effect starts.


title: Extended Riemannian Geometry I: Local Double Field Theory

abstract:
  We present an extended version of Riemannian geometry suitable for the
description of current formulations of double field theory (DFT). This
framework is based on graded manifolds and it yields extended notions of
symmetries, dynamical data and constraints. In special cases, we recover
general relativity with and without 1-, 2- and 3-form gauge potentials as well
as DFT. We believe that our extended Riemannian geometry helps to clarify the
role of various constructions in DFT. For example, it leads to a covariant form
of the strong section condition. Furthermore, it should provide a useful step
towards global and coordinate invariant descriptions of T- and U-duality
invariant field theories.


title:
Self-Organized Velocity Pulses of Dense Colloidal Suspensions in
  Microchannel Flow

abstract:
  We present a numerical study of dense colloidal suspensions in
pressure-driven microchannel flow in two dimensions. The colloids are modeled
as elastic and frictional spheres suspended in a Newtonian fluid, which we
simulate using the method of multi-particle collision dynamics. The model
reproduces periodic velocity and density pulse trains, traveling upstream in
the microchannel, which are found in experiments conducted by L. Isa et al.
[Phys. Rev. Lett. 102, 058302 (2009)]. We show that colloid-wall friction and
the resultant force chains are crucial for the formation of these pulses. With
increasing colloid density first solitary jams occur, which become periodic
pulse trains at intermediate densities and unstable solitary pulses at high
densities. We formulate a phenomenological continuum model and show how these
spatio-temporal flow and density profiles can be understood as homoclinic and
periodic orbits in traveling-wave equations.


title: Second-Harmonic Imaging in Random Media

abstract:
  We consider the problem of optical imaging of small nonlinear scatterers in
random media. We propose an extension of coherent interferometric imaging
(CINT) that applies to scatterers that emit second-harmonic light. We compare
this method to a nonlinear version of migration imaging and find that the
images obtained by CINT are more robust to statistical fluctuations. This
finding is supported by a resolution analysis that is carried out in the
setting of geometrical optics in random media. It is also consistent with
numerical simulations for which the assumptions of the geometrical optics model
do not hold.


title: Supporting Education in Math Sciences with a Low-budget LMS SAKAI

abstract:
  In this paper we present the Low-budget LMS Sakai, the analysis conducted and
its selection from a list of few popular Low-budget LMSs, as well as its
capability in presentation of math texts and formulas. The MATHEIS e-learning
system for learning mathematics and informatics and its empowering with few
software agent based features including the new developed GUPA (Graphic User
Presentation Agent) software agent is emphasized. The plugins offered for Sakai
allow powerful mathematics presentation capabilities, one of them being the
WIRIS plugin. The paper is focused on the Sakai WIRIS plugin implementation.