title: Interstellar scintillations of PSR B1919+21: space-ground interferometry

abstract:
  We carried out observations of pulsar PSR B1919+21 at 324 MHz to study the
distribution of interstellar plasma in the direction of this pulsar. We used
the RadioAstron (RA) space radiotelescope together with two ground telescopes:
Westerbork (WB) and Green Bank (GB). The maximum baseline projection for the
space-ground interferometer was about 60000 km. We show that interstellar
scintillation of this pulsar consists of two components: diffractive
scintillations from inhomogeneities in a layer of turbulent plasma at a
distance $z_{1} = 440$ pc from the observer or homogeneously distributed
scattering material to pulsar; and weak scintillations from a screen located
near the observer at $z_{2} = 0.14 \pm 0.05$ pc. Furthermore, in the direction
to the pulsar we detected a prism that deflects radiation, leading to a shift
of observed source position. We show that the influence of the ionosphere can
be ignored for the space-ground baseline. Analysis of the spatial coherence
function for the space-ground baseline (RA-GB) yielded the scattering angle in
the observer plane: $\theta_{scat}$ = 0.7 mas. An analysis of the
time-frequency correlation function for weak scintillations yielded the angle
of refraction in the direction to the pulsar: $\theta_{ref, 0}$ = 110 ms and
the distance to the prism $z_{prism} \le 2$ pc.


title: A ram-pressure threshold for star formation

abstract:
  In turbulent fragmentation, star formation occurs in condensations created by
converging flows. The condensations must be sufficiently massive, dense and
cool to be gravitationally unstable, so that they start to contract; {\it and}
they must then radiate away thermal energy fast enough for self-gravity to
remain dominant, so that they continue to contract. For the metallicities and
temperatures in local star forming clouds, this second requirement is only met
robustly when the gas couples thermally to the dust, because this delivers the
capacity to radiate across the full bandwidth of the continuum, rather than
just in a few discrete spectral lines. This translates into a threshold for
vigorous star formation, which can be written as a minimum ram-pressure Pcrit ~
4 10^-11 dyne. Pcrit is independent of temperature, and corresponds to flows
with molecular hydrogen number-density nH2 and velocity v satisfying nH2 v^2 >
800 cm^-3 (km/s)^2. This in turn corresponds to a minimum molecular hydrogen
column-density for vigorous star formation, NH2crit ~ 4 10^21 cm^-2 (SIGMAcrit
~ 100 MSun pc^-2), and a minimum visual extinction AVcrit ~ 9. The
characteristic diameter and line-density for a star-forming filament when this
threshold is just exceeded -- a sweet spot for local star formation regions --
are 2Rfil ~ 0.1 pc and mufil ~ 13 MSun pc^-2. The characteristic diameter and
mass for a prestellar core condensing out of such a filament are 2Rcore ~ 0.1
pc, and Mcore ~ MSun. We also show that fragmentation of a shock-compressed
layer is likely to commence while the convergent flows creating the layer are
still ongoing, and we stress that, under this circumstance, the phenomenology
and characteristic scales for fragmentation of the layer are fundamentally
different from those derived traditionally for pre-existing layers.


title:
Measuring Transit Signal Recovery in the Kepler Pipeline. III.
  Completeness of the Q1-Q17 DR24 Planet Candidate Catalogue, with Important
  Caveats for Occurrence Rate Calculations

abstract:
  With each new version of the Kepler pipeline and resulting planet candidate
catalogue, an updated measurement of the underlying planet population can only
be recovered with an corresponding measurement of the Kepler pipeline detection
efficiency. Here, we present measurements of the sensitivity of the pipeline
(version 9.2) used to generate the Q1-Q17 DR24 planet candidate catalog
(Coughlin et al. 2016). We measure this by injecting simulated transiting
planets into the pixel-level data of 159,013 targets across the entire Kepler
focal plane, and examining the recovery rate. Unlike previous versions of the
Kepler pipeline, we find a strong period dependence in the measured detection
efficiency, with longer (>40 day) periods having a significantly lower
detectability than shorter periods, introduced in part by an incorrectly
implemented veto. Consequently, the sensitivity of the 9.2 pipeline cannot be
cast as a simple one-dimensional function of the signal strength of the
candidate planet signal as was possible for previous versions of the pipeline.
We report on the implications for occurrence rate calculations based on the
Q1-Q17 DR24 planet candidate catalog and offer important caveats and
recommendations for performing such calculations. As before, we make available
the entire table of injected planet parameters and whether they were recovered
by the pipeline, enabling readers to derive the pipeline detection sensitivity
in the planet and/or stellar parameter space of their choice.


title: Exactly marginal deformations from exceptional generalised geometry

abstract:
  We apply exceptional generalised geometry to the study of exactly marginal
deformations of $\mathcal{N}=1$ SCFTs that are dual to generic AdS$_5$ flux
backgrounds in type IIB or eleven-dimensional supergravity. In the gauge
theory, marginal deformations are parametrised by the space of chiral primary
operators of conformal dimension three, while exactly marginal deformations
correspond to quotienting this space by the complexified global symmetry group.
We show how the supergravity analysis gives a geometric interpretation of the
gauge theory results. The marginal deformations arise from deformations of
generalised structures that solve moment maps for the generalised
diffeomorphism group and have the correct charge under the generalised Reeb
vector, generating the R-symmetry. If this is the only symmetry of the
background, all marginal deformations are exactly marginal. If the background
possesses extra isometries, there are obstructions that come from fixed points
of the moment maps. The exactly marginal deformations are then given by a
further quotient by these extra isometries.
  Our analysis holds for any $\mathcal{N}=2$ AdS$_5$ flux background. Focussing
on the particular case of type IIB Sasaki-Einstein backgrounds we recover the
result that marginal deformations correspond to perturbing the solution by
three-form flux at first order. In various explicit examples, we show that our
expression for the three-form flux matches those in the literature and the
obstruction conditions match the one-loop beta functions of the dual SCFT.


title:
Multi-epoch Spectroscopy of Dwarf Galaxies with AGN Signatures:
  Identifying Sources with Persistent Broad H-alpha Emission

abstract:
  We use time-domain optical spectroscopy to distinguish between broad emission
lines powered by accreting black holes (BHs) or stellar processes (i.e.,
supernovae) for 16 galaxies identified as AGN candidates by Reines \etal
(2013). Our study is primarily focused on those objects with narrow
emission-line ratios dominated by star formation. Based on follow-up spectra
taken with the Magellan Echellette Spectrograph (MagE), the Dual Imaging
Spectrograph, and the Ohio State Multi-Object Spectrograph, we find that the
broad H$\alpha$ emission has faded or was ambiguous for all of the star-forming
objects (14/16) over baselines ranging from 5 to 14 years. For the two objects
in our follow-up sample with narrow-line AGN signatures (RGG 9 and RGG 119), we
find persistent broad H$\alpha$ emission consistent with an AGN origin.
Additionally, we use our MagE observations to measure stellar velocity
dispersions for 15 objects in the Reines et al. (2013) sample, all with
narrow-line ratios indicating the presence of an AGN. Stellar masses range from
$\sim5\times10^{8}$ to $3\times10^{9}$~\msun, and we measure $\sigma_{\ast}$
ranging from $28-71~{\rm km~s^{-1}}$. These $\sigma_{\ast}$ correspond to some
of the lowest-mass galaxies with optical signatures of AGN activity. We show
that RGG 119, the one object which has both a measured $\sigma_{\ast}$ and
persistent broad H$\alpha$ emission, falls near the extrapolation of the $\rm
M_{BH}-\sigma_{\star}$ relation to the low-mass end.


title: The chemical evolution of the Bootes I ultra-faint dwarf galaxy

abstract:
  We present chemical abundance measurements of two metal-poor red giant stars
in the ultra-faint dwarf galaxy Bootes I, based on Magellan/MIKE
high-resolution spectra. For Boo I-980, with [Fe/H]=-3.1, we present the first
elemental abundance measurements while Boo I-127, with [Fe/H]=-2.0, shows
abundances in good agreement with previous measurements. Light and iron-peak
element abundance ratios in the two Bootes I stars, as well as those of most
other Boootes I members, collected from the literature, closely resemble those
of regular metal-poor halo stars. Neutron-capture element abundances Sr and Ba
are systematically lower than the main halo trend, and also show a significant
abundance spread. Overall, this is similar to what has been found for other
ultra-faint dwarf galaxies. We apply corrections to the carbon abundances
(commensurate with stellar evolutionary status) of the entire sample and find
21% of stars to be carbon-enhanced metal-poor (CEMP) stars, compared to 13%
without using the carbon correction. We reassess the metallicity distribution
functions (MDF) for the CEMP stars and non-CEMP stars, and confirm earlier
claims that CEMP stars might belong to a different, earlier population.
Applying a set of abundance criteria to test to what extent Bootes I could be a
surviving first galaxy suggests that it is one of the earliest assembled
systems that perhaps received gas from accretion from other clouds in the
system, or from swallowing a first galaxy or building block type object. This
resulted in the two stellar populations observable today.


title: Observational challenges in Ly-alpha intensity mapping

abstract:
  Intensity mapping (IM) is sensitive to the cumulative line emission of
galaxies. As such it represents a promising technique for statistical studies
of galaxies fainter than the limiting magnitude of traditional galaxy surveys.
The strong hydrogen Ly-alpha line is the primary target for such an experiment,
as its intensity is linked to star formation activity and the physical state of
the interstellar (ISM) and intergalactic (IGM) medium. However, to extract the
meaningful information one has to solve the confusion problems caused by
interloping lines from foreground galaxies. We discuss here the challenges for
a Ly-alpha IM experiment targeting z > 4 sources. We find that the Ly-alpha
power spectrum can be in principle easily (marginally) obtained with a 40 cm
space telescope in a few days of observing time up to z < 8 (z = 10) assuming
that the interloping lines (e.g. H-alpha, [O II], [O III] lines) can be
efficiently removed. We show that interlopers can be removed by using an
ancillary photometric galaxy survey with limiting AB mag 26 in the NIR bands
(Y, J, H, or K). This would enable detection of the Ly-alpha signal from 5 < z
< 9 faint sources. However, if a [C II] IM experiment is feasible, by
cross-correlating the Ly-alpha with the [C II] signal the required depth of the
galaxy survey can be decreased to AB mag 24. This would bring the detection at
reach of future facilities working in close synergy.


title: Anomalous Hall effect in Weyl superconductors

abstract:
  We present a theory of the anomalous Hall effect in a topological Weyl
superconductor with broken time reversal symmetry. Specifically, we consider a
ferromagnetic Weyl metal with two Weyl nodes of opposite chirality near the
Fermi energy. In the presence of inversion symmetry, such a metal experiences a
weak-coupling Bardeen-Cooper-Schrieffer (BCS) instability, with pairing of
parity-related eigenstates. Due to the nonzero topological charge, carried by
the Weyl nodes, such a superconductor is necessarily topologically nontrivial,
with Majorana surface states coexisting with the Fermi arcs of the normal Weyl
metal. We demonstrate that, surprisingly, the anomalous Hall conductivity of
such a superconducting Weyl metal coincides with that of a nonsuperconducting
one, under certain conditions, in spite of the nonconservation of charge in a
superconductor. We relate this to the existence of an extra (nearly) conserved
quantity in a Weyl metal, the chiral charge.


title: A generalization of dual symmetry and reciprocity for symmetric algebras

abstract:
  Slicing a module into semisimple ones is useful to study modules. Loewy
structures provide a means of doing so. To establish the Loewy structures of
projective modules over a finite dimensional symmetric algebra over a field
$F$, the Landrock lemma is a primary tool. The lemma and its corollary relate
radical layers of projective indecomposable modules to radical layers of the
$F$-duals of those modules ("dual symmetry") and to socle layers of those
modules ("reciprocity").
  We generalize these results to an arbitrary finite dimensional algebra $A$.
Our main theorem, which is the same as the Landrock lemma for finite
dimensional symmetric algebras, relates radical layers of projective
indecomposable modules $P$ to radical layers of the $A$-duals of those modules
and to socle layers of injective indecomposable modules $\nu P$ where
$\nu({-})$ is the Nakayama functor. A key tool to prove the main theorem is a
pair of adjoint functors, which we call socle functors and capital functors.


title:
High Power Characterization of Piezoelectric Ceramics Using the
  Burst/Transient Method with Resonance and Antiresonance Analysis

abstract:
  In this paper, a comprehensive methodology for characterizing the high power
resonance behavior of bulk piezoelectric ceramics using the burst method is
described. In the burst method, the sample is electrically driven at its
resonance frequency, and then either a short circuit or an open circuit
condition is imposed, after which the vibration decays at the resonance or
antiresonance frequency, respectively. This decay can be used to measure the
quality factor in either of these conditions. The resulting current in the
short circuit vibration condition is related to the vibration velocity through
the "force factor." The generated voltage in the open circuit vibration
condition corresponds to the displacement by the "voltage factor." The force
factor and the voltage factor are related to material properties and physical
dimensions of the sample. Using this method, the high power behavior of the
permittivity, compliance, piezoelectric charge constant, electromechanical
coupling factor, and material losses can be determined directly by measuring
the resonance (short circuit) and antiresonance (open circuit) frequencies,
their corresponding quality factors, the force factor $A$, and the voltage
factor $B$. The experimental procedure to apply this method is described and
demonstrated on commercially available hard and semi-hard PZT materials of
$k_{31}$


title: Power-Law Entanglement Spectrum in Many-Body Localized Phases

abstract:
  The entanglement spectrum of the reduced density matrix contains information
beyond the von Neumann entropy and provides unique insights into exotic orders
or critical behavior of quantum systems. Here, we show that strongly disordered
systems in the many-body localized phase have power-law entanglement spectra,
arising from the presence of extensively many local integrals of motion. The
power-law entanglement spectrum distinguishes many-body localized systems from
ergodic systems, as well as from ground states of gapped integrable models or
free systems in the vicinity of scale-invariant critical points. We confirm our
results using large-scale exact diagonalization. In addition, we develop a
matrix-product state algorithm which allows us to access the eigenstates of
large systems close to the localization transition, and discuss general
implications of our results for variational studies of highly excited
eigenstates in many-body localized systems.

categories: cond-mat.dis-nn cond-mat.stat-mech cond-mat.str-el quant-ph


title: String order via Floquet interactions in atomic systems

abstract:
  We study the transverse-field Ising model with interactions that are
modulated in time. In a rotating frame, the system is described by a
time-independent Hamiltonian with many-body interactions, similar to the
cluster Hamiltonians of measurement-based quantum computing. In one dimension,
there is a three-body interaction, which leads to string order instead of
conventional magnetic order. We show that the string order is robust to
power-law interactions that decay with the cube of distance. In two and three
dimensions, there are five- and seven-body interactions. We discuss adiabatic
preparation of the ground state as well as experimental implementation with
trapped ions, Rydberg atoms, and polar molecules.


title: Interfacial magnetic anisotropy from a 3-dimensional Rashba substrate

abstract:
  We study the magnetic anisotropy which arises at the interface between a thin
film ferromagnet and a 3-d Rashba material. The 3-d Rashba material is
characterized by the spin-orbit strength $\alpha$ and the direction of broken
bulk inversion symmetry $\hat n$. We find an in-plane uniaxial anisotropy in
the $\hat{z}\times\hat{n}$ direction, where $\hat z$ is the interface normal.
For realistic values of $\alpha$, the uniaxial anisotropy is of a similar order
of magnitude as the bulk magnetocrystalline anisotropy. Evaluating the uniaxial
anisotropy for a simplified model in 1-d shows that for small band filling, the
in-plane easy axis anisotropy scales as $\alpha^4$ and results from a twisted
exchange interaction between the spins in the 3-d Rashba material and the
ferromagnet. For a ferroelectric 3-d Rashba material, $\hat n$ can be
controlled with an electric field, and we propose that the interfacial magnetic
anisotropy could provide a mechanism for electrical control of the magnetic
orientation.


title: Dynamical estimate of post main sequence stellar masses in 47 Tucanae

abstract:
  We use the effects of mass segregation on the radial distribution of
different stellar populations in the core of 47 Tucanae to find estimates for
the masses of stars at different post main sequence evolutionary stages. We
take samples of main sequence (MS) stars from the core of 47 Tucanae, at
different magnitudes (i.e. different masses), and use the effects of this
dynamical process to develop a relation between the radial distance (RD) at
which the cumulative distribution reaches the 20th and 50th percentile, and
stellar mass. From these relations we estimate the masses of different post MS
populations. We find that mass remains constant for stars going through the
evolutionary stages between the upper MS up to the horizontal branch (HB). By
comparing RDs of the HB stars with stars of lower masses, we can exclude a mass
loss greater than 0.09M during the red giant branch (RGB) stage at nearly the
3{\sigma} level. The slightly higher mass estimates for the asymptotic giant
branch (AGB) are consistent with the AGB having evolved from somewhat more
massive stars. The AGB also exhibits evidence of contamination by more massive
stars, possibly blue stragglers (BSS), going through the RGB phase. We do not
include the BSS in this paper due to the complexity of these objects, instead,
the complete analysis of this population is left for a companion paper. The
process to estimate the masses described in this paper are exclusive to the
core of 47 Tuc.


title:
The Evolution of Galaxies at Constant Number Density: A Less Biased View
  of Star Formation, Quenching, and Structural Formation

abstract:
  Due to significant galaxy contamination and impurity in stellar mass selected
samples (up to 95% from z=0-3), we examine the star formation history,
quenching time-scales, and structural evolution of galaxies using a constant
number density selection with data from the UKIDSS Ultra-Deep Survey field.
Using this methodology we investigate the evolution of galaxies at a variety of
number densities from $z=0-3$. We find that samples chosen at number densities
ranging from $3\times10^{-4}$ to 10$^{-5}$ galaxies Mpc$^{-3}$ (corresponding
to $z\sim0.5$ stellar masses of M$_{*}= 10^{10.95-11.6}$ M$_{0}$) have a star
forming blue fraction of $\sim50$\% at $z\sim2.5$, which evolves to a nearly
$100$\% quenched red and dead population by $z\sim 1$. We also see evidence for
number density downsizing, such that the galaxies selected at the lowest
densities (highest masses) become a homogeneous red population before those at
higher number densities. Examining the evolution of the colours for these
systems furthermore shows that the formation redshift of galaxies selected at
these number densities is $z_{\rm form}>3$. The structural evolution through
size and Sersic index fits reveal that while there remains evolution in terms
of galaxies becoming larger and more concentrated in stellar mass at lower
redshifts, the magnitude of the change is significantly smaller than for a mass
selected sample. We also find that changes in size and structure continues at
$z < 1$, and is coupled strongly to passivity evolution. We conclude that
galaxy structure is driving the quenching of galaxies, such that galaxies
become concentrated before they become passive.


title:
Extreme Vortex States and the Growth of Enstrophy in 3D Incompressible
  Flows

abstract:
  In this investigation we study extreme vortex states defined as
incompressible velocity fields with prescribed enstrophy $\mathcal{E}_0$ which
maximize the instantaneous rate of growth of enstrophy $d\mathcal{E}/dt$. We
provide {an analytic} characterization of these extreme vortex states in the
limit of vanishing enstrophy $\mathcal{E}_0$ and, in particular, show that the
Taylor-Green vortex is in fact a local maximizer of $d\mathcal{E} / dt$ {in
this limit}. For finite values of enstrophy, the extreme vortex states are
computed numerically by solving a constrained variational optimization problem
using a suitable gradient method. In combination with a continuation approach,
this allows us to construct an entire family of maximizing vortex states
parameterized by their enstrophy. We also confirm the findings of the seminal
study by Lu & Doering (2008) that these extreme vortex states saturate (up to a
numerical prefactor) the fundamental bound $d\mathcal{E} / dt < C \,
\mathcal{E}^3$, for some constant $C > 0$. The time evolution corresponding to
these extreme vortex states leads to a larger growth of enstrophy than the
growth achieved by any of the commonly used initial conditions with the same
enstrophy $\mathcal{E}_0$. However, based on several different diagnostics,
there is no evidence of any tendency towards singularity formation in finite
time. Finally, we discuss possible physical reasons why the initially large
growth of enstrophy is not sustained for longer times.


title: Using an implicit function to prove common fixed point theorems

abstract:
  In this paper, we prove common fixed point results for a self-mappings
satisfying an implicit function which is general enough to cover a multitude of
known as well as unknown contractions. Our results modify, unify, extend and
generalize many relevant results of the existing literature. Interestingly,
unlike several other cases, our main results deduce a nonlinear order-theoretic
version of a well-known fixed point theorem (proved for quasi-contraction) due
to \'{C}iri\'{c} (Proc. Amer. Math. Soc. (54) 267-273, 1974). Finally, in the
setting of metric spaces, we drive a sharpened version of Theorem 1 due to
Berinde and Vetro (Fixed Point Theory Appl. 2012:105).


title: Cocenters of Hecke-Clifford and spin Hecke algebras

abstract:
  We determine a basis of the cocenter (i.e., the zeroth Hochschild homology)
of the degenerate affine Hecke-Clifford and spin Hecke algebras in classical
types.


title: On Fano Schemes of Toric Varieties

abstract:
  Let $X_\mathcal{A}$ be the projective toric variety corresponding to a finite
set of lattice points $\mathcal{A}$. We show that irreducible components of the
Fano scheme $\mathbf{F}_k(X_\mathcal{A})$ parametrizing $k$-dimensional linear
subspaces of $X_\mathcal{A}$ are in bijection to so-called maximal Cayley
structures for $\mathcal{A}$. We explicitly describe these irreducible
components and their intersection behaviour, characterize when
$\mathbf{F}_k(X_\mathcal{A})$ is connected, and prove that if $X_\mathcal{A}$
is smooth in dimension $k$, then every component of
$\mathbf{F}_k(X_\mathcal{A})$ is smooth in its reduced structure. Furthermore,
in the special case $k=\dim X_\mathcal{A}-1$, we describe the non-reduced
structure of $\mathbf{F}_k(X_\mathcal{A})$. Our main result is closely related
to concurrent work done independently by Furukawa and Ito.


title:
Do asteroids evaporate near pulsars? Induction heating by pulsar waves
  revisited

abstract:
  We investigate the evaporation of close-by pulsar companions, such as
planets, asteroids, and white dwarfs, by induction heating. Assuming that the
outflow energy is dominated by a Poynting flux (or pulsar wave) at the location
of the companions, we calculate their evaporation timescales, by applying the
Mie theory. Depending on the size of the companion compared to the incident
electromagnetic wavelength, the heating regime varies and can lead to a total
evaporation of the companion. In particular, we find that inductive heating is
mostly inefficient for small pulsar companions, although it is generally
considered the dominant process. Small objects like asteroids can survive
induction heating for $10^4\,$years at distances as small as $1\,R_\odot$ from
the neutron star. For degenerate companions, induction heating cannot lead to
evaporation and another source of heating (likely by kinetic energy of the
pulsar wind) has to be considered. It was recently proposed that bodies
orbiting pulsars are the cause of fast radio bursts; the present results
explain how those bodies can survive in the pulsar's highly energetic
environment.


title: Edit distance and its computation

abstract:
  In this paper, we provide a method for determining the asymptotic value of
the maximum edit distance from a given hereditary property. This method permits
the edit distance to be computed without using Szemer\'edi's Regularity Lemma
directly. Using this new method, we are able to compute the edit distance from
hereditary properties for which it was previously unknown. For some graphs $H$,
the edit distance from ${\rm Forb}(H)$ is computed, where ${\rm forb}(H)$ is
the class of graphs which contain no induced copy of graph $H$.
  Those graphs for which we determine the edit distance asymptotically are
$H=K_a+E_b$, an $a$-clique with $b$ isolated vertices, and $H=K_{3,3}$, a
complete bipartite graph. We also provide a graph, the first such construction,
for which the edit distance cannot be determined just by considering partitions
of the vertex set into cliques and cocliques.
  In the process, we develop weighted generalizations of Tur\'an's theorem,
which may be of independent interest.


title: Controlling the Dark Exciton Spin Eigenstates by External Magnetic Field

abstract:
  We study the dark exciton's behavior as a coherent physical two-level spin
system (qubit) using an external magnetic field in the Faraday configuration.
Our studies are based on polarization-sensitive intensity autocorrelation
measurements of the optical transition resulting from the recombination of a
spin-blockaded biexciton state, which heralds the dark exciton and its spin
state. We demonstrate control over the dark exciton eigenstates without
degrading its decoherence time. Our observations agree well with computational
predictions based on a master equation model.


title: IceCube PeV Neutrinos and Leptophilic Dark Matter

abstract:
  We analyze the scenario where the IceCube high energy neutrino events are
explained in terms of an extraterrestrial flux due to two different components:
a contribution coming from know astrophysical sources for energies up to few
hundreds TeV and a top-down contribution originated by the decay of heavy dark
matter particles with a mass of few PeV. Contrary to previous approaches, we
consider a leptophilic three-body decay that dominates at PeV energies due to
the absence of quarks in the final state. We find that the theoretical
predictions of such a scenario are in a slightly better agreement with the
IceCube data if the astrophysical component has a cut-off at about 100 TeV.
This interpretation of IceCube data can be easily tested in the near future
since the decaying dark matter scenario predicts a sharp cut-off at PeV energy
scale and the observation of an anisotropy towards Galactic Center of our
Galaxy in contrast with the isotropic astrophysical flux.


title:
Analysis of a Predictor-Corrector Method for Computationally Efficient
  Modeling of Surface Effects in 1D

abstract:
  The regular Cauchy--Born method is a useful and efficient tool for analyzing
bulk properties of materials in the absence of defects. However, the method
normally fails to capture surface effects, which are essential to determining
material properties at small length scales. In this paper, we present a
corrector method that improves upon the prediction for material behavior from
the Cauchy--Born method over a small boundary layer at the surface of a 1D
material by capturing the missed surface effects. We justify the separation of
the problem into a bulk response and a localized surface correction by
establishing an error estimate, which vanishes in the long wavelength limit.


title: A Holographic Dual of the Quantum Inequalities

abstract:
  In this note, we establish the 2-D Quantum Inequalities - first proved by
Flanagan - for all CFTs with a causal holographic dual. Following the treatment
of Kelly \& Wall, we establish that the Boundary Causality Condition in an
asymptotic AdS spacetime implies the Quantum Inequalities on the boundary. Our
results extend easily to curved spacetime and are stable under deformations of
the CFT by relevant operators. We discuss higher dimensional generalizations
and possible connections to recent bounds on $a/c$ in 4-D CFTs.


title: On the Eccentricity Excitation in Post-Main Sequence Binaries

abstract:
  Several classes of stellar binaries with post-main sequence (post-MS)
components - millisecond pulsars with the white dwarf companions (MSP+WD) and
periods P_b~30 d, binaries hosting post-asymptotic giant branch (post-AGB)
stars or barium stars with P_b~several yr - feature high eccentricities (up to
0.4) despite the expectation of their efficient tidal circularization during
the AGB phase. It was suggested that the eccentricities of these binaries can
be naturally excited by their tidal coupling to the circumbinary disk, formed
by the material ejected from the binary. Here we critically reassess this idea
using simple arguments rooted in the global angular momentum conservation of
the disk+binary system. Compared to previous studies we (1) fully account for
the viscous spreading of the circumbinary disk, (2) consider the possibility of
reaccretion from the disk onto the binary (in agreement with simulations and
empirical evidence), and (3) allow for the reduced viscosity after the disk
expands, cools, and forms dust. These ingredients conspire to significantly
lower the efficiency of eccentricity excitation by the disk tides. We find that
explaining eccentricities of the post-AGB binaries is difficult and requires
massive ($> 10^{-2}M_\odot$), long-lived ($> 10^5$ yr) circumbinary disks, that
do not reaccrete. Reaccretion is detrimental for the eccentricity growth also
in the MSP+WD systems. Reduced efficiency of the disk-driven excitation
motivates study of alternative mechanisms for producing the peculiar
eccentricities of the post-MS binaries.


title: Delay Bounds for Multiclass FIFO

abstract:
  FIFO is perhaps the simplest scheduling discipline. For single-class FIFO,
its delay guarantee performance has been extensively studied: The well-known
results include a stochastic delay bound for $GI/GI/1$ by Kingman and a
deterministic delay bound for $D/D/1$ by Cruz. However, for multiclass FIFO,
few such results are available. To fill the gap, we prove delay bounds for
multiclass FIFO in this work, considering both deterministic and stochastic
cases. Specifically, delay bounds are presented for multiclass D/D/1, GI/GI/1
and G/G/1. In addition, examples are provided for several basic settings to
demonstrate the obtained bounds in more explicit forms, which are also compared
with simulation results.


title:
Breaking the disc-halo degeneracy in NGC 1291 using hydrodynamic
  simulations

abstract:
  We present a pilot study on the nearby massive galaxy NGC 1291, in which we
aim to constrain the dark matter in the inner regions, by obtaining a dynamical
determination of the disc mass-to-light ratio (M/L). To this aim, we model the
bar-induced dust lanes in the galaxy, using hydrodynamic gas response
simulations. The models have three free parameters, the M/L of the disc, the
bar pattern speed and the disc height function. We explore the parameter space
to find the best fit models, i.e. those in which the morphology of the shocks
in the gas simulations matches the observed dust lanes. The best-fit models
suggest that the M/L of NGC 1291 agrees with that predicted by stellar
population synthesis models in the near-infrared
($\approx$0.6\,$M_{\odot}/L_{\odot}$), which leads to a borderline maximum disc
for this galaxy. The bar rotates fast, with corotation radius $\leq$ 1.4 times
the bar length. Additionally, we find that the height function has a
significant effect on the results, and can bias them towards lower or higher
M/L.


title: Variations on Gromov's open-dense orbit theorem

abstract:
  We investigate several situations where the local homogeneity of a geometric
structure on a dense open subset of a manifold implies the local homogeneity
everywhere. This results in a strengthening of the conclusions in Gromov's
open-dense orbit theorem. In particular, we show that any smooth closed
3-dimensional Lorentz manifold with a topologically transitive isometric action
must be locally homogeneous.


title:
Charged, rotating black objects in Einstein-Maxwell-dilaton theory in
  $D\ge 5$

abstract:
  We show that the general framework proposed in arXiv:1410.0581 for the study
of asymptotically flat vacuum black objects with $k+1$ equal magnitude angular
momenta in $D\geq 5$ spacetime dimensions (with $0\leq k\leq \big[\frac{D-5}{2}
\big]$) can be extended to the case of Einstein-Maxwell-dilaton (EMd) theory.
This framework can describe black holes with spherical horizon topology, the
simplest solutions corresponding to a class of electrically charged (dilatonic)
Myers-Perry black holes. Balanced charged black objects with $ S^{n+1} \times
S^{2k+1}$ horizon topology can also be studied (with $D=2k+n+4$). Black rings
correspond to the case $k=0$, while the solutions with $k>0$ are black
ringoids. The basic properties of EMd solutions are discussed for the special
case of a Kaluza-Klein value of the dilaton coupling constant. We argue that
all features of these solutions can be derived from those of the vacuum seed
configurations.


title:
Robust Image Descriptors for Real-Time Inter-Examination Retargeting in
  Gastrointestinal Endoscopy

abstract:
  For early diagnosis of malignancies in the gastrointestinal tract,
surveillance endoscopy is increasingly used to monitor abnormal tissue changes
in serial examinations of the same patient. Despite successes with optical
biopsy for in vivo and in situ tissue characterisation, biopsy retargeting for
serial examinations is challenging because tissue may change in appearance
between examinations. In this paper, we propose an inter-examination
retargeting framework for optical biopsy, based on an image descriptor designed
for matching between endoscopic scenes over significant time intervals. Each
scene is described by a hierarchy of regional intensity comparisons at various
scales, offering tolerance to long-term change in tissue appearance whilst
remaining discriminative. Binary coding is then used to compress the descriptor
via a novel random forests approach, providing fast comparisons in Hamming
space and real-time retargeting. Extensive validation conducted on 13 in vivo
gastrointestinal videos, collected from six patients, show that our approach
outperforms state-of-the-art methods.


title:
Resource Provisioning and Profit Maximization for Transcoding in
  Information Centric Networking

abstract:
  Adaptive bitrate streaming (ABR) has been widely adopted to support video
streaming services over heterogeneous devices and varying network conditions.
With ABR, each video content is transcoded into multiple representations in
different bitrates and resolutions. However, video transcoding is computing
intensive, which requires the transcoding service providers to deploy a large
number of servers for transcoding the video contents published by the content
producers. As such, a natural question for the transcoding service provider is
how to provision the computing resource for transcoding the video contents
while maximizing service profit. To address this problem, we design a cloud
video transcoding system by taking the advantage of cloud computing technology
to elastically allocate computing resource. We propose a method for jointly
considering the task scheduling and resource provisioning problem in two
timescales, and formulate the service profit maximization as a two-timescale
stochastic optimization problem. We derive some approximate policies for the
task scheduling and resource provisioning. Based on our proposed methods, we
implement our open source cloud video transcoding system Morph and evaluate its
performance in a real environment. The experiment results demonstrate that our
proposed method can reduce the resource consumption and achieve a higher profit
compared with the baseline schemes.


title:
Renormalization of Optical Transition Strengths in Semiconductor
  Nanoparticles due to Band Mixing

abstract:
  Unique optical properties of semiconductor nanoparticles (SN) make them very
promising in the multitude of applications including lasing, light emission and
photovoltaics. In many of these applications it is imperative to understand the
physics of interaction of electrons in a SN with external electromagnetic
fields on the quantitative level. In particular, the strength of
electron-photon coupling determines such important SN parameters as the
radiative lifetime and absorption cross section. This strength is often assumed
to be fully encoded by the so called Kane momentum matrix element. This
parameter, however, pertains to a bulk semiconductor material and, as such, is
not sensitive to the quantum confinement effects in SNs. In this work we
demonstrate that the quantum confinement, via the so called band mixing, can
result in a significant suppression of the strength of electron interaction
with electromagnetic field. Within the envelope function formalism we show how
this suppression can be described by introducing an effective energy-dependent
Kane momentum. Then, the effect of band mixing on the efficiencies of various
photoinduced processes can be fully captured by the conventional formulae
(e.g., spontaneous emission rate), once the conventional Kane momentum is
substituted with the renormalized energy-dependent Kane momentum introduced in
here. As an example, we evaluate the energy-dependent Kane momentum for
spherical $\rm{PbSe}$ and $\rm{PbS}$ SNs (i.e., quantum dots) and show that
neglecting band mixing in these systems can result in the overestimation of
absorption cross sections and emission rates by a factor of $\sim$2.


title: The Molecular Aharonov-Bohm effect Redux

abstract:
  A solvable molecular collision model that predicts Aharonov-Bohm (AB) like
scattering in the adiabatic approximation is introduced. For it, we propagate
coupled channel wave packets without resorting to a Born-Oppenheimer (BO)
approximation. In those, exact, solutions we find evidence of topological phase
dislocation lines that are independent of the collision energy and provide
definitive signatures of AB-like scattering. The results of these simulations
contrast with the conclusions of a recent study that suggests survival of the
molecular Aharonov-Bohm (MAB) effect only in the adiabatic limit in which the
nuclear reduced mass $\mu \rightarrow \infty$.
  We discuss generalizations of this model and consider possible screening of
the Mead-Truhlar vector potential by the presence of multiple conical
intersections (CI). We demonstrate that the Wilson loop phase integral has the
value $-1$ if it encloses an odd-number of CI's, and takes the value $+1$ for
an even number. Within the scope of this model, we investigate the ultra-cold
limit of scattering solutions in the presence of a conical intersection and
comment on the relevance of Wigner threshold behavior for s-wave scattering.


title: CP-even scalar boson production via gluon fusion at the LHC

abstract:
  In view of the searches at the LHC for scalar particle resonances in addition
to the 125 GeV Higgs boson, we present the cross section for a CP-even scalar
produced via gluon fusion at N3LO in perturbative QCD assuming that it couples
directly to gluons in an effective theory approach. We refine our prediction by
taking into account the possibility that the scalar couples to the top-quark
and computing the corresponding contributions through NLO in perturbative QCD.
We assess the theoretical uncertainties of the cross section due to missing
higher-order QCD effects and we provide the necessary information for obtaining
the cross section value and uncertainty from our results in specific scenarios
beyond the Standard Model. We also give detailed results for the case of a 750
GeV scalar, which will be the subject of intense experimental studies.


title:
Search for supersymmetry in the multijet and missing transverse momentum
  final state: an analysis performed on 2.3 fb$^{-1}$ of 13 TeV pp collision
  data collected with the CMS detector

abstract:
  We present results from a generic search for strongly produced supersymmetric
particles in pp collisions in the multijet + missing transverse momentum final
state. The data sample corresponds to 2.3 fb$^{-1}$ recorded by the CMS
experiment at $\sqrt{s}=13$ TeV. This search is motivated by supersymmetry
(SUSY) models that avoid fine-tuning of the higgs mass. In such models, certain
strongly produced SUSY particles, including the gluino and top squark, are
predicted to have masses on the order of a TeV. These particles also have some
of the highest production cross sections in SUSY and give rise to final states
with distinct, high jet multiplicity event signatures. To make the analysis
sensitive to a wide range of such final states, events are classified by the
number of jets, the scalar sum of the transverse momenta of the jets, the
vector sum of the transverse momenta of the jets, and the number of b-tagged
jets. No significant excess is observed beyond the standard model (SM)
expectation. The results are interpreted as limits on simplified SUSY models.
In these models, gluino masses as high as 1600 GeV are excluded at 95\% CL for
scenarios with low $\tilde{\chi}_{1}^{0}$ mass, exceeding the most stringent
limits set in by CMS at $\sqrt{s}=8$ TeV by more than 200 GeV in several
simplified models.


title: Searching for topological defect dark matter with optical atomic clocks

abstract:
  The total mass density of the Universe appears to be dominated by dark
matter. However, beyond its gravitational interactions at the galactic scale,
little is known about its nature. Extensions of the quantum electrodynamics
Lagrangian with dark-matter coupling terms may result in changes to Standard
Model parameters. Recently, it was proposed that a network of atomic clocks
could be used to search for transient signals of a hypothetical dark matter in
the form of stable topological defects. The clocks become desynchronized when a
dark-matter object sweeps through the network. This pioneering approach, which
is applicable only for distant clocks, is limited by the quality of the fibre
links. Here, we present an alternative experimental approach that is applicable
to both closely spaced and distant optical atomic clocks and benefits from
their individual susceptibilities to dark matter, hence not requiring fibre
links. We explore a new dimension of astrophysical observations by constraining
the strength of atomic coupling to the hypothetical dark-matter cosmic objects.
Our experimental constraint exceeds the previous limits; in fact, it not only
reaches the ultimate level expected to be achievable with a constellation of
GPS atomic clocks but also has a large potential for improvement.


title: Packing arborescences in random digraphs

abstract:
  We study the problem of packing arborescences in the random digraph $\mathcal
D(n,p)$, where each possible arc is included uniformly at random with
probability $p=p(n)$. Let $\lambda(\mathcal D(n,p))$ denote the largest integer
$\lambda\geq 0$ such that, for all $0\leq \ell\leq \lambda$, we have
$\sum_{i=0}^{\ell-1} (\ell-i)|\{v: d^{in}(v) = i\}| \leq \ell$. We show that
the maximum number of arc-disjoint arborescences in $\mathcal D(n,p)$ is
$\lambda(\mathcal D(n,p))$ a.a.s. We also give tight estimates for
$\lambda(\mathcal D(n,p))$ depending on the range of $p$.


title: A geometric perspective on p-adic properties of mock modular forms

abstract:
  Bringmann, Guerzhoy and Kane have shown how to correct mock modular forms by
a certain linear combination of the Eichler integral of their shadows in order
to obtain p-adic modular forms in the sense of Serre. In this paper, we give a
new proof of their results (for good primes p) by employing the geometric
theory of harmonic Maass forms developed by the first author and the theory of
overconvergent modular forms due to Katz and Coleman.


title: Traces arising from regular inclusions

abstract:
  We study the problem of extending a state on an abelian $C^*$- subalgebra to
a tracial state on the ambient $C^*$-algebra. We propose an approach that is
well-suited to the case of regular inclusions, in which there is a large supply
of normalizers of the subalgebra. Conditional expectations onto the subalgebra
give natural extensions of a state to the ambient $C^*$-algebra; we prove that
these extensions are tracial states if and only if certain invariance
properties of both the state and conditional expectations are satisfied. In the
example of a groupoid $C^*$-algebra, these invariance properties correspond to
invariance of associated measures on the unit space under the action of
bisections. Using our framework, we are able to completely describe the tracial
state space of a Cuntz-Krieger graph algebra. Along the way we introduce
certain operations called graph tightenings, which both streamline our
description and provides connections to related finiteness questions in graph
$C^*$-algebras. Our investigation has close connections with the so-called
unique state extension property and its variants.


title: Memristor model based on fuzzy window function

abstract:
  Memristor (memory-resistor) is the fourth passive circuit element. We
introduce a memristor model based on a fuzzy logic window function. Fuzzy
models are flexible, which enables the capture of the pinched hysteresis
behavior of the memristor. The introduced fuzzy model avoids common problems
associated with window-function based memristor models, such as the terminal
state problem, and the symmetry issues. The model captures the memristor
behavior with a simple rule-base which gives an insight of how memristors work.
Because of the flexibility offered by the fuzzy system, shape and distribution
of input and output membership functions can be tuned to capture the behavior
of various real memristors.


title:
Entangled Dynamics in Macroscopic Quantum Tunneling of Bose-Einstein
  Condensates

abstract:
  Tunneling of a quasibound state is a non-smooth process in the entangled
many-body case. Using time-evolving block decimation, we show that repulsive
(attractive) interactions speed up (slow down) tunneling, which occurs in
bursts. While the escape time scales exponentially with small interactions, the
maximization time of the von Neumann entanglement entropy between the remaining
quasibound and escaped atoms scales quadratically. Stronger interactions
require higher order corrections. Entanglement entropy is maximized when about
half the atoms have escaped.


title:
A Robust Measurement of the Mass Outflow Rate of the Galactic Outflow
  from NGC 6090

abstract:
  To evaluate the impact of stellar feedback, it is critical to estimate the
mass outflow rates of galaxies. Past estimates have been plagued by uncertain
assumptions about the outflow geometry, metallicity, and ionization fraction.
Here we use Hubble Space Telescope ultraviolet spectroscopic observations of
the nearby starburst NGC 6090 to demonstrate that many of these quantities can
be constrained by the data. We use the Si~{\sc IV} absorption lines to
calculate the scaling of velocity (v), covering fraction (C$_f$), and density
with distance from the starburst (r), assuming the Sobolev optical depth and a
velocity law of the form: v$~\propto(1 -\mathrm{R}_\mathrm{i}/\mathrm{r}
)^\beta$ (where R$_\mathrm{i}$ is the inner outflow radius). We find that the
velocity ($\beta$=0.43) is consistent with an outflow driven by an r$^{-2}$
force with the outflow radially accelerated, while the scaling of the covering
fraction ($C_f \propto \mathrm{r}^{-0.82}$) suggests that cool clouds in the
outflow are in pressure equilibrium with an adiabatically expanding medium. We
use the column densities of four weak metal lines and CLOUDY photoionization
models to determine the outflow metallicity, the ionization correction, and the
initial density of the outflow. Combining these values with the profile
fitting, we find R$_\mathrm{i}$ = 63 pc, with most of the mass within 300~pc of
the starburst. Finally, we find that the maximum mass outflow rate is
2.3~M$_\odot$ yr$^{-1}$ and the mass loading factor (outflow divided by the
star formation rate) is 0.09, a factor of 10 lower than the value calculated
using common assumptions for the geometry, metallicity and ionization structure
of the outflow.


title:
Algebraic approach to electro-optic modulation of light: Exactly
  solvable multimode quantum model

abstract:
  We theoretically study electro-optic light modulation based on the quantum
model where the linear electro-optic effect and the externally applied
microwave field result in the interaction between optical cavity modes. The
model assumes that the number of interacting modes is finite and effects of the
mode overlapping coefficient on the strength of the intermode interaction can
be taken into account through dependence of the coupling coefficient on the
mode characteristics. We show that, under certain conditions, the model is
exactly solvable and, in the semiclassical approximation where the microwave
field is treated as a classical mode, can be analyzed using the technique of
the Jordan mappings for the su(2) Lie algebra. Analytical results are applied
to study effects of light modulation on the frequency dependence of the photon
counting rate. We also establish the conditions of validity of the
semiclassical approximation by applying the methods of polynomially deformed
Lie algebras for analysis of the model with quantized microwave field.


title:
Detection of Lyman-Alpha Emission From a Triple Imaged z=6.85 Galaxy
  Behind MACS J2129.4-0741

abstract:
  We report the detection of Ly$\alpha$ emission at $\sim9538$\AA{} in the
Keck/DEIMOS and \HST WFC3 G102 grism data from a triply-imaged galaxy at
$z=6.846\pm0.001$ behind galaxy cluster MACS J2129.4$-$0741. Combining the
emission line wavelength with broadband photometry, line ratio upper limits,
and lens modeling, we rule out the scenario that this emission line is \oii at
$z=1.57$. After accounting for magnification, we calculate the weighted average
of the intrinsic Ly$\alpha$ luminosity to be
$\sim1.3\times10^{42}~\mathrm{erg}~\mathrm{s}^{-1}$ and Ly$\alpha$ equivalent
width to be $74\pm15$\AA{}. Its intrinsic UV absolute magnitude at 1600\AA{} is
$-18.6\pm0.2$ mag and stellar mass $(1.5\pm0.3)\times10^{7}~M_{\odot}$, making
it one of the faintest (intrinsic $L_{UV}\sim0.14~L_{UV}^*$) galaxies with
Ly$\alpha$ detection at $z\sim7$ to date. Its stellar mass is in the typical
range for the galaxies thought to dominate the reionization photon budget at
$z\gtrsim7$; the inferred Ly$\alpha$ escape fraction is high ($\gtrsim 10$\%),
which could be common for sub-$L^*$ $z\gtrsim7$ galaxies with Ly$\alpha$
emission. This galaxy offers a glimpse of the galaxy population that is thought
to drive reionization, and it shows that gravitational lensing is an important
avenue to probe the sub-$L^*$ galaxy population.


title:
ALMA Observations of Circumstellar Disks in the Upper Scorpius OB
  Association

abstract:
  We present ALMA observations of 106 G-, K-, and M-type stars in the Upper
Scorpius OB Association hosting circumstellar disks. With these data, we
measure the 0.88 mm continuum and $^{12}$CO $J$ = 3$-$2 line fluxes of disks
around low-mass ($0.14-1.66$ $M_{\odot}$) stars at an age of 5-11 Myr. Of the
75 primordial disks in the sample, 53 are detected in the dust continuum and 26
in CO. Of the 31 disks classified as debris/evolved transitional disks, 5 are
detected in the continuum and none in CO. The lack of CO emission in
approximately half of the disks with detected continuum emission can be
explained if CO is optically thick but has a compact emitting area ($\lesssim
40$ au), or if the CO is heavily depleted by a factor of at least $\sim1000$
relative to interstellar medium abundances and is optically thin. The continuum
measurements are used to estimate the dust mass of the disks. We find a
correlation between disk dust mass and stellar host mass consistent with a
power-law relation of $M_{\mathrm{dust}}\propto M_*^{1.67\pm0.37}$. Disk dust
masses in Upper Sco are compared to those measured in the younger Taurus
star-forming region to constrain the evolution of disk dust mass. We find that
the difference in the mean of $\log(M_{\mathrm{dust}}/M_*)$ between Taurus and
Upper Sco is $0.64\pm0.09$, such that $M_{\mathrm{dust}}/M_*$ is lower in Upper
Sco by a factor of $\sim4.5$.


title:
Distributed Parallel D8 Up-Slope Area Calculation in Digital Elevation
  Models

abstract:
  This paper presents a parallel algorithm for calculating the
eight-directional (D8) up-slope contributing area in digital elevation models
(DEMs). In contrast with previous algorithms, which have potentially unbounded
inter-node communications, the algorithm presented here realizes strict bounds
on the number of inter-node communications. Those bounds in turn allow D8
attributes to be processed for arbitrarily large DEMs on hardware ranging from
average desktops to supercomputers. The algorithm can use the OpenMP and MPI
parallel computing models, either in combination or separately. It partitions
the DEM between slave nodes, calculates an internal up-slope area by replacing
information from other slaves with variables representing unknown quantities,
passes the results on to a master node which combines all the slaves' data, and
passes information back to each slave, which then computes its final result. In
this way each slave's DEM partition is treated as a simple unit in the DEM as a
whole and only two communications take place per node.


title: Lux in obscuro: Photon Orbits of Extremal Black Holes Revisited

abstract:
  It has been shown in the literature that the event horizon of an extremal
asymptotically flat Reissner-Nordstrom black hole is also a stable photon
sphere. We further clarify this statement and give a general proof that this
holds for a large class of static spherically symmetric black hole spacetimes
with an extremal horizon. In contrast, in the Doran frame, an extremal
asymptotically flat Kerr black hole has an unstable photon orbit on the
equatorial plane of its horizon. In addition, we show that an extremal
asymptotically flat Kerr-Newman black hole exhibits two equatorial photon
orbits if a < M/2, one of which is on the extremal horizon in the Doran frame
and is stable, whereas the second one outside the horizon is unstable. For a >
M/2, there is only one equatorial photon orbit, located on the extremal
horizon, and it is unstable. There can be no photon orbit on the horizon of a
non-extremal Kerr-Newman black hole.


title: Supervised Learning with Quantum-Inspired Tensor Networks

abstract:
  Tensor networks are efficient representations of high-dimensional tensors
which have been very successful for physics and mathematics applications. We
demonstrate how algorithms for optimizing such networks can be adapted to
supervised learning tasks by using matrix product states (tensor trains) to
parameterize models for classifying images. For the MNIST data set we obtain
less than 1% test set classification error. We discuss how the tensor network
form imparts additional structure to the learned model and suggest a possible
generative interpretation.


title:
The Quality of the Covariance Selection Through Detection Problem and
  AUC Bounds

abstract:
  We consider the problem of quantifying the quality of a model selection
problem for a graphical model. We discuss this by formulating the problem as a
detection problem. Model selection problems usually minimize a distance between
the original distribution and the model distribution. For the special case of
Gaussian distributions, the model selection problem simplifies to the
covariance selection problem which is widely discussed in literature by
Dempster [2] where the likelihood criterion is maximized or equivalently the
Kullback-Leibler (KL) divergence is minimized to compute the model covariance
matrix. While this solution is optimal for Gaussian distributions in the sense
of the KL divergence, it is not optimal when compared with other information
divergences and criteria such as Area Under the Curve (AUC).
  In this paper, we analytically compute upper and lower bounds for the AUC and
discuss the quality of model selection problem using the AUC and its bounds as
an accuracy measure in detection problem. We define the correlation
approximation matrix (CAM) and show that analytical computation of the KL
divergence, the AUC and its bounds only depend on the eigenvalues of CAM. We
also show the relationship between the AUC, the KL divergence and the ROC curve
by optimizing with respect to the ROC curve. In the examples provided, we pick
tree structures as the simplest graphical models. We perform simulations on
fully-connected graphs and compute the tree structured models by applying the
widely used Chow-Liu algorithm [3]. Examples show that the quality of tree
approximation models are not good in general based on information divergences,
the AUC and its bounds when the number of nodes in the graphical model is
large. We show both analytically and by simulations that the 1-AUC for the tree
approximation model decays exponentially as the dimension of graphical model
increases.


title:
Axioms of the Analytic Hierarchy Process (AHP) and its Generalization to
  Dependence and Feedback: The Analytic Network Process (ANP)

abstract:
  The AHP/ANP are multicriteria decision-making theories that deal with both
hierarchic structures when the criteria are independent of the alternatives and
with networks when there is any dependence within and between elements of the
decision. Both of them have been repeatedly used in practice by various
researchers and practitioners. From the perspective of almost 40 years of
practice in solving problems using both theories, some of their properties seem
to be more important than others. The article indicates four of them as
fundamental for understanding AHP/ANP. These are the axioms related to
structure, computation, and expectation. The mathematical formulation of the
axioms is preceded by an introduction explaining the motivation behind the
introduced concepts. The article is expository and it is an improved and
refined version of the work [1].


title:
Simulations of Particle Impact at Lunar Magnetic Anomalies and
  Comparison with Spectral Observations

abstract:
  Ever since the Apollo era, a question has remained as to the origin of the
lunar swirls (high albedo regions coincident with the regions of surface
magnetization). Different processes have been proposed for their origin. In
this work we test the idea that the lunar swirls have a higher albedo relative
to surrounding regions because they deflect incoming solar wind particles that
would otherwise darken the surface. 3D particle tracking is used to estimate
the influence of five lunar magnetic anomalies on incoming solar wind. The
regions investigated include Mare Ingenii, Gerasimovich, Renier Gamma,
Northwest of Apollo and Marginis. Both protons and electrons are tracked as
they interact with the anomalous magnetic field and impact maps are calculated.
The impact maps are then compared to optical observations and comparisons are
made between the maxima and minima in surface fluxes and the albedo and optical
maturity of the regions. Results show deflection of slow to typical solar wind
particles on a larger scale than the fine scale optical, swirl, features. It is
found that efficiency of a particular anomaly for deflection of incoming
particles does not only scale directly with surface magnetic field strength,
but also is a function of the coherence of the magnetic field. All anomalous
regions can also produce moderate deflection of fast solar wind particles. The
anomalies' influence on ~ 1 GeV SEP particles is only apparent as a slight
modification of the incident velocities.


title:
Conditional analysis for mixed covariates, with application to feed
  intake of lactating sows

abstract:
  We propose a novel modeling framework to study the effect of covariates of
various types on the conditional distribution of the response. The methodology
accommodates flexible model structure, allows for joint estimation of the
quantiles at all levels, and involves a computationally efficient estimation
algorithm. Extensive numerical investigation confirms good performance of the
proposed method. The methodology is motivated by and applied to a lactating sow
study, where the primary interest is to understand how the dynamic change of
minute-by-minute temperature in the farrowing rooms within a day (functional
covariate) is associated with low quantiles of feed intake of lactating sows,
while accounting for other sow-specific information (vector covariate).


title: Lyapunov spectra of Coulombic and gravitational periodic systems

abstract:
  We compute Lyapunov spectra for Coulombic and gravitational versions of the
one-dimensional systems of parallel sheets with periodic boundary conditions.
Exact time evolution of tangent-space vectors are derived and are utilized
toward computing Lypaunov characteristic exponents using an event-driven
algorithm. The results indicate that the energy dependence of the largest
Lyapunov exponent emulates that of Kolmogorov-entropy density for each system
at different degrees of freedom. Our approach forms an effective and
approximation-free tool toward studying the dynamical properties exhibited by
the Coulombic and gravitational systems and finds applications in investigating
indications of thermodynamic transitions in large versions of the spatially
periodic systems.


title:
Adsorption structures and energetics of molecules on metal surfaces:
  Bridging experiment and theory

abstract:
  Adsorption geometry and stability of organic molecules on surfaces are key
parameters that determine the observable properties and functions of hybrid
inorganic/organic systems (HIOSs). Despite many recent advances in precise
experimental characterization and improvements in first-principles electronic
structure methods, reliable databases of structures and energetics for large
adsorbed molecules are largely amiss. In this review, we present such a
database for a range of molecules adsorbed on metal single-crystal surfaces.
The systems we analyze include noble-gas atoms, conjugated aromatic molecules,
carbon nanostructures, and heteroaromatic compounds adsorbed on five different
metal surfaces. The overall objective is to establish a diverse benchmark
dataset that enables an assessment of current and future electronic structure
methods, and motivates further experimental studies that provide ever more
reliable data. Specifically, the benchmark structures and energetics from
experiment are here compared with the recently developed van der Waals (vdW)
inclusive density-functional theory (DFT) method, DFT+vdW$^{\mathrm{surf}}$. In
comparison to 23 adsorption heights and 17 adsorption energies from experiment
we find a mean average deviation of 0.06 \AA{} and 0.16 eV, respectively. This
confirms the DFT+vdW$^{\mathrm{surf}}$ method as an accurate and efficient
approach to treat HIOSs. A detailed discussion identifies remaining challenges
to be addressed in future development of electronic structure methods, for
which the here presented benchmark database may serve as an important
reference.


title: A comparison of semi-deterministic and stochastic search techniques

abstract:
  This paper presents an investigation of two search techniques, tabu search
(TS) and simulated annealing (SA), to assess their relative merits when applied
to engineering design optimisation. Design optimisation problems are generally
characterised as having multi-modal search spaces and discontinuities making
global optimisation techniques beneficial. Both techniques claim to be capable
of locating globally optimum solutions on a range of problems but this
capability is derived from different underlying philosophies. While tabu search
uses a semi-deterministic approach to escape local optima, simulated annealing
uses a complete stochastic approach. The performance of each technique is
investigated using a structural optimisation problem. These performances are
then compared to each other as and to a steepest descent (SD) method.


title: The Newton complementary dual revisited

abstract:
  This work deals with the notion of Newton complementary duality as raised
originally in the work of the second author and B. Costa. A conceptual revision
of the main steps of the notion is accomplished which then leads to a vast
simplification and improvement of several statements concerning rational maps
and their images. A ring-homomorphism like map is introduced that allows for a
close comparison between the respective graphs of a rational map and its Newton
dual counterpart.


title:
Predicting Unemployment Claims Using Regional and Exogenous Signals: A
  Sparse Modeling Approach

abstract:
  In this paper we apply a time series based Vector Auto Regressive (VAR)
approach to the problem of predicting unemployment insurance claims in
different census regions of the United States. Unemployment insurance claims
data, reported weekly, are a leading indicator of the US unemployment rate.
Gathering weekly unemployment claims and aggregating by region, we model
correlation between the different census regions. Additionally, we explore the
use of external variables such as Bing search query volumes and URL site clicks
related to unemployment claims. To prevent any spurious predictors from
appearing in the model we use sparse model based regularization. Preliminary
results indicate that our approach is promising and in ongoing work we are
extending the approach to a larger set of predictors and a longer data range.


title: Efficient Nonparametric Smoothness Estimation

abstract:
  Sobolev quantities (norms, inner products, and distances) of probability
density functions are important in the theory of nonparametric statistics, but
have rarely been used in practice, partly due to a lack of practical
estimators. They also include, as special cases, $L^2$ quantities which are
used in many applications. We propose and analyze a family of estimators for
Sobolev quantities of unknown probability density functions. We bound the bias
and variance of our estimators over finite samples, finding that they are
generally minimax rate-optimal. Our estimators are significantly more
computationally tractable than previous estimators, and exhibit a
statistical/computational trade-off allowing them to adapt to computational
constraints. We also draw theoretical connections to recent work on fast
two-sample testing. Finally, we empirically validate our estimators on
synthetic data.


title: A Compositional Neuro-Controller for Advanced Motor Control Tasks

abstract:
  Humans and animals developed a sophisticated motor control apparatus and
there is much evidence that it has a modular structure. The modularity offers a
range of benefits, e.g. ability to learn dissociable motion styles without
interference and forgetting, fast adaptation and de-adaptation to changes
conditions. However in robotics, building a controller that can efficiently
incrementally learn new motion styles and provide switching between them is a
formidable challenge. In this paper we address the problem by proposing a novel
biologically inspired compositional neuro-controller. We have shown that the
compositional controller is able to reproduce a set of trajectories more
efficiently comparing to a simple controller, exploiting incremental learning
benefits. Second, we have demonstrated that the proposed controller is able to
learn different locomotion styles and switch between them in a simulated
robot-snake.


title:
A Conservative Scheme for Vlasov Poisson Landau modeling collisional
  plasmas

abstract:
  We have developed a deterministic conservative solver for the inhomogeneous
Fokker-Planck-Landau equation coupled with the Poisson equation, which is a
{classical mean-field} primary model for collisional plasmas. Two subproblems,
i.e. the Vlasov-Poisson problem and homogeneous Landau problem, are obtained
through time-splitting methods, and treated separately by the Runge-Kutta
Discontinuous Galerkin method and a conservative spectral method, respectively.
To ensure conservation when projecting between the two different computing
grids, a special conservation routine is designed to link the solutions of
these two subproblems. This conservation routine accurately enforces
conservation of moments in Fourier space. The entire numerical scheme is
implemented with parallelization with hybrid MPI and OpenMP. Numerical
experiments are provided to study linear and nonlinear Landau Damping problems
and two-stream flow problem as well.


title:
Generalized Charged Nariai Solutions in Arbitrary Even Dimensions with
  Multiple Magnetic Charges

abstract:
  Higher-dimensional solutions for Einstein-Maxwell equations that generalize
the charged Nariai spacetime are obtained. The solutions presented here are
made from the direct product of several 2-spaces of constant curvature. These
solutions turn out to have many magnetic charges, contrary to the usual
higher-dimensional generalization of the Nariai spacetime, which has no
magnetic charge at all. These solutions are then used to generate black hole
metrics. Finally, it is analyzed how these generalized Nariai solutions are
modified in more general theories of gravity.


title:
Optimization via Separated Representations and the Canonical Tensor
  Decomposition

abstract:
  We introduce a new, quadratically convergent algorithm for finding maximum
absolute value entries of tensors represented in the canonical format. The
computational complexity of the algorithm is linear in the dimension of the
tensor. We show how to use this algorithm to find global maxima of non-convex
multivariate functions in separated form. We demonstrate the performance of the
new algorithms on several examples.


title:
Primordial fluctuations from inflation in dRGT bimetric theory of
  gravity

abstract:
  We investigate primordial gravitational waves and curvature perturbations in
de Rham-Gabadadze-Tolley (dRGT) bimetric gravity. We evaluate the power-spectra
in the leading order in slow roll. Taking into account the decay of massive
graviton, we find that the action up to the second order reduces to the
Einstein theory with a non-minimally coupled scalar field, which is simplified
to a minimally coupled model by conformal transformation. We also find that the
tensor to scalar ratio for large field inflation with power law potential is
larger than the general relativity counterpart for any choice of parameters in
dRGT bimetric gravity. In addition, we confirm that the usual consistency
relation holds and we have a steeper spectrum for gravitational waves.


title:
A Generic Framework for Assessing the Performance Bounds of Image
  Feature Detectors

abstract:
  Since local feature detection has been one of the most active research areas
in computer vision during the last decade, a large number of detectors have
been proposed. The interest in feature-based applications continues to grow and
has thus rendered the task of characterizing the performance of various feature
detection methods an important issue in vision research. Inspired by the good
practices of electronic system design, a generic framework based on the
repeatability measure is presented in this paper that allows assessment of the
upper and lower bounds of detector performance and finds statistically
significant performance differences between detectors as a function of image
transformation amount by introducing a new variant of McNemars test in an
effort to design more reliable and effective vision systems. The proposed
framework is then employed to establish operating and guarantee regions for
several state-of-the-art detectors and to identify their statistical
performance differences for three specific image transformations: JPEG
compression, uniform light changes and blurring. The results are obtained using
a newly acquired, large image database (20482) images with 539 different
scenes. These results provide new insights into the behaviour of detectors and
are also useful from the vision systems design perspective.


title:
Chemical tagging in the SDSS-III/APOGEE survey: new identifications of
  halo stars with globular cluster origins

abstract:
  We present new identifications of five red giant stars in the Galactic halo
with chemical abundance patterns that indicate they originally formed in
globular clusters. Using data from the Apache Point Observatory Galactic
Evolution Experiment (APOGEE) Survey available through Sloan Digital Sky Survey
Data Release 12 (DR12), we first identify likely halo giants, and then search
those for the well-known chemical tags associated with globular clusters,
specifically enrichment in nitrogen and aluminum. We find that 2% of the halo
giants in our sample have this chemical signature, in agreement with previous
results. Following the interpretation in our previous work on this topic, this
would imply that at least 13% of halo stars originally formed in globular
clusters. Recent developments in the theoretical understanding of globular
cluster formation raise questions about that interpretation, and we concede the
possibility that these migrants represent a small fraction of the halo field.
There are roughly as many stars with the chemical tags of globular clusters in
the halo field as there are in globular clusters, whether or not they are
accompanied by a much larger chemically untaggable population of former
globular cluster stars.


title:
Markov Selection and $W$-strong Feller for 3D Stochastic Primitive
  Equations

abstract:
  This paper studies some analytical properties of weak solutions of 3D
stochastic primitive equations with periodic boundary conditions. The
martingale problem associated to this model is shown to have a family of
solutions satisfying the Markov property, which is achieved by means of an
abstract selection principle. The Markov property is crucial to extend the
regularity of the transition semigroup from small times to arbitrary times.
Thus, under a regular additive noise, every Markov solution is shown to have a
property of continuous dependence on initial conditions, which follows from
employing the weak-strong uniqueness principle and the Bismut-Elworthy-Li
formula.


title: Measurement of neutron capture on $^{136}$Xe

abstract:
  $^{136}$Xe is a 0{\nu}{\beta}{\beta} decay candidate isotope, and is used in
multiple experiments searching for this hypothetical decay mode. These
experiments require precise information about neutron capture for their
background characterization and minimization. Thermal and resonant neutron
capture on $^{136}$Xe have been measured at the Detector for Advanced Neutron
Capture Experiments (DANCE) at the Los Alamos Neutron Science Center. A neutron
beam ranging from thermal energy to greater than 100 keV was incident on a gas
cell filled with isotopically pure $^{136}$Xe. The relative neutron capture
cross sections for neutrons at thermal energies and the first resonance at
2.154 keV have been measured. Additionally, the {\gamma} cascades for these
captures have been measured, and cascade models have been developed which may
be used by 0{\nu}{\beta}{\beta} experiments using $^{136}$Xe.


title:
Robust Reserve Capacity Provision and Peak Load Reduction from Buildings
  in Smart Grids

abstract:
  This paper proposes a robust demand-side control algorithm in a smart grid
environment for heating, ventilation and air conditioning (HVAC) systems. A
robust model predictive control (RMPC) scheme in a receding horizon fashion is
deployed, which optimizes electricity cost and capacity market participation of
the HVAC system, while satisfying comfort and operational constraints of the
building and utility, respectively. Thermal load uncertainties experienced by
the HVAC system are included to perform a realistic assessment of the developed
controller. The National Electricity Market of Singapore (NEMS) is used as a
case study and the developed RMPC scheme is tested for various price signals
and scenarios. Numerical simulation results show the effectiveness of the
developed framework to be readily adopted by utilities -- interested in
realizing a grid-friendly and economicaly eficient demand response (DR)
strategy.


title: The scaling of boson sampling experiments

abstract:
  Boson sampling is the problem of generating a quantum bit stream whose
average is the permanent of a $n\times n$ matrix. The bitstream is created as
the output of a prototype quantum computing device with $n$ input photons. It
is a fundamental challenge to verify boson sampling, and the question of how
output count rates scale with matrix size $n$ is crucial. Here we apply results
from random matrix theory to establish scaling laws for average count rates in
boson sampling experiments with arbitrary inputs and losses. The results show
that, even with losses included, verification of nonclassical behaviour at
large $n$ values is indeed possible.


title:
Analysis of Network Clustering Algorithms and Cluster Quality Metrics at
  Scale

abstract:
  Notions of community quality underlie network clustering. While studies
surrounding network clustering are increasingly common, a precise understanding
of the realtionship between different cluster quality metrics is unknown. In
this paper, we examine the relationship between stand-alone cluster quality
metrics and information recovery metrics through a rigorous analysis of four
widely-used network clustering algorithms -- Louvain, Infomap, label
propagation, and smart local moving. We consider the stand-alone quality
metrics of modularity, conductance, and coverage, and we consider the
information recovery metrics of adjusted Rand score, normalized mutual
information, and a variant of normalized mutual information used in previous
work. Our study includes both synthetic graphs and empirical data sets of sizes
varying from 1,000 to 1,000,000 nodes.
  We find significant differences among the results of the different cluster
quality metrics. For example, clustering algorithms can return a value of 0.4
out of 1 on modularity but score 0 out of 1 on information recovery. We find
conductance, though imperfect, to be the stand-alone quality metric that best
indicates performance on information recovery metrics. Our study shows that the
variant of normalized mutual information used in previous work cannot be
assumed to differ only slightly from traditional normalized mutual information.
  Smart local moving is the best performing algorithm in our study, but
discrepancies between cluster evaluation metrics prevent us from declaring it
absolutely superior. Louvain performed better than Infomap in nearly all the
tests in our study, contradicting the results of previous work in which Infomap
was superior to Louvain. We find that although label propagation performs
poorly when clusters are less clearly defined, it scales efficiently and
accurately to large graphs with well-defined clusters.


title: MCMC for Imbalanced Categorical Data

abstract:
  Many modern applications collect highly imbalanced categorical data, with
some categories relatively rare. Bayesian hierarchical models combat data
sparsity by borrowing information, while also quantifying uncertainty. However,
posterior computation presents a fundamental barrier to routine use; a single
class of algorithms does not work well in all settings and practitioners waste
time trying different types of MCMC approaches. This article was motivated by
an application to quantitative advertising in which we encountered extremely
poor computational performance for common data augmentation MCMC algorithms but
obtained excellent performance for adaptive Metropolis. To obtain a deeper
understanding of this behavior, we give strong theory results on computational
complexity in an infinitely imbalanced asymptotic regime. Our results show
computational complexity of Metropolis is logarithmic in sample size, while
data augmentation is polynomial in sample size. The root cause of poor
performance of data augmentation is a discrepancy between the rates at which
the target density and MCMC step sizes concentrate. In general, MCMC algorithms
that have a similar discrepancy will fail in large samples - a result with
substantial practical impact.


title: Recurrent Exponential-Family Harmoniums without Backprop-Through-Time

abstract:
  Exponential-family harmoniums (EFHs), which extend restricted Boltzmann
machines (RBMs) from Bernoulli random variables to other exponential families
(Welling et al., 2005), are generative models that can be trained with
unsupervised-learning techniques, like contrastive divergence (Hinton et al.
2006; Hinton, 2002), as density estimators for static data. Methods for
extending RBMs--and likewise EFHs--to data with temporal dependencies have been
proposed previously (Sutskever and Hinton, 2007; Sutskever et al., 2009), the
learning procedure being validated by qualitative assessment of the generative
model. Here we propose and justify, from a very different perspective, an
alternative training procedure, proving sufficient conditions for optimal
inference under that procedure. The resulting algorithm can be learned with
only forward passes through the data--backprop-through-time is not required, as
in previous approaches. The proof exploits a recent result about information
retention in density estimators (Makin and Sabes, 2015), and applies it to a
"recurrent EFH" (rEFH) by induction. Finally, we demonstrate optimality by
simulation, testing the rEFH: (1) as a filter on training data generated with a
linear dynamical system, the position of which is noisily reported by a
population of "neurons" with Poisson-distributed spike counts; and (2) with the
qualitative experiments proposed by Sutskever et al. (2009).


title:
Studies of Spuriously Shifting Resonances in Time-dependent Density
  Functional Theory

abstract:
  Adiabatic approximations in time-dependent density functional theory (TDDFT)
will in general yield unphysical time-dependent shifts in the resonance
positions of a system driven far from its ground-state. This spurious
time-dependence is rationalized in [J. I. Fuks, K. Luo, E. D. Sandoval and N.
T. Maitra, Phys. Rev. Lett. {\bf 114}, 183002 (2015)] in terms of the violation
of an exact condition by the non-equilibrium exchange-correlation kernel of
TDDFT. Here we give details on the derivation and discuss reformulations of the
exact condition that apply in special cases. In its most general form, the
condition states that when a system is left in an arbitrary state, in the
absence of time-dependent external fields nor ionic motion, the TDDFT resonance
position for a given transition is independent of the state. Special cases
include the invariance of TDDFT resonances computed with respect to any
reference interacting stationary state of a fixed potential, and with respect
to any choice of appropriate stationary Kohn-Sham reference state. We then
present several case studies, including one that utilizes the
adiabatically-exact approximation, that illustrate the conditions and the
impact of their violation on the accuracy of the ensuing dynamics. In
particular, charge-transfer across a long-range molecule is hampered, and we
show how adjusting the frequency of a driving field to match the time-dependent
shift in the charge-transfer resonance frequency, results in a larger charge
transfer over time.


title: A combinatorial description of dual defects of toric varieties

abstract:
  From a finite set in a lattice, we can define a toric variety embedded in a
projective space. In this paper, we give a combinatorial description of the
dual defect of the toric variety using the structure of the finite set as a
Cayley sum with suitable conditions. We also interpret the description
geometrically.


title: Recursive utility maximization under partial information

abstract:
  This paper concerns the recursive utility maximization problem under partial
information. We first transform our problem under partial information into the
one under full information. When the generator of the recursive utility is
concave, we adopt the variational formulation of the recursive utility which
leads to a stochastic game problem and a characterization of the saddle point
of the game is obtained. Then, we study the K-ignorance case and explicit
saddle points of several examples are obtained. At last, when the generator of
the recursive utility is smooth, we employ the terminal perturbation method to
characterize the optimal terminal wealth.


title:
SU(2)-SU(4) Kondo Crossover and Emergent Electric Polarization in a
  Triangular Triple Quantum Dot

abstract:
  We study an orbitally degenerate Kondo effect in a triangular triple quantum
dot (TTQD), where the three dots are connected vertically with a single
metallic lead through electron tunneling. Both spin and orbital degrees of
freedom play an important role in the SU(4) Kondo effect. This is demonstrated
by an equilateral TTQD Kondo system at half-filling, by Wilson's numerical
renormalization group method. We show how an emergent electric polarization of
the TTQD is associated with a crossover from SU(4) to SU(2) symmetry in the
low-temperature state. A marked sign reversal of the electric polarization is
generated by the fine-tuning of Kondo coupling with degenerate orbitals, which
can be utilized to reveal orbital dynamics in the SU(4) Kondo effect.


title: Shear-Induced Nitric Oxide Production by Endothelial Cells

abstract:
  We present a biochemical model of the wall shear stress (WSS)-induced
activation of endothelial nitric oxide synthase (eNOS) in an endothelial cell
(EC). The model includes three key mechanotransducers: mechanosensing ion
channels, integrins and G-protein-coupled receptors. The reaction cascade
consists of two interconnected parts. The first is rapid activation of calcium,
which results in formation of calcium-calmodulin complexes, followed by
recruitment of eNOS from caveolae. The second is phosphoryaltion of eNOS by
protein kinases PKC and AKT. The model also includes a negative feedback loop
due to inhibition of calcium influx into the cell by cyclic guanosine
monophosphate (cGMP). In this feedback, increased nitric oxide (NO) levels
cause an increase in cGMP levels, so that cGMP inhibition of calcium influx can
limit NO production. The model was used to predict the dynamics of NO
production by an EC subjected to a step increase of WSS from zero to a finite
physiologically relevant value. Among several experimentally observed features,
the model predicts a highly nonlinear, biphasic transient behavior of eNOS
activation and NO production: a rapid initial activation due to the very rapid
influx of calcium into the cytosol (occurring within 1 to 5 minutes) is
followed by a sustained period of activation due to protein kinases.


title: Irreducible Projective Representations and Their Physical Applications

abstract:
  An eigenfunction method is applied to reduce the regular projective
representations (Reps) of finite groups to obtain their irreducible projective
Reps. Anti-unitary groups are treated specially, where the decoupled factor
systems and modified Schur's lemma are introduced. We discuss the applications
of irreducible Reps in many-body physics. It is shown that in symmetry
protected topological phases, geometric defects or symmetry defects may carry
projective Rep of the symmetry group; while in symmetry enriched topological
phases, intrinsic excitations (such as spinons or visons) may carry projective
Rep of the symmetry group. We also discuss the applications of projective Reps
in problems related to spectrum degeneracy, such as in search of models without
sign problem in quantum Monte Carlo Simulations.


title: Kostka-Shoji polynomials and Lusztig's convolution diagram

abstract:
  We propose an $r$-variable version of Kostka-Shoji polynomials
$K^-_{\lambda\mu}$ for $r$-multipartitions $\lambda,\mu$. Our version has
positive integral coefficients and encodes the graded multiplicities in the
space of global sections of a line bundle over Lusztig's iterated convolution
diagram for the cyclic quiver $\tilde{A}_{r-1}$.


title: Heuristics for Planning, Plan Recognition and Parsing

abstract:
  In a recent paper, we have shown that Plan Recognition over STRIPS can be
formulated and solved using Classical Planning heuristics and algorithms. In
this work, we show that this formulation subsumes the standard formulation of
Plan Recognition over libraries through a compilation of libraries into STRIPS
theories. The libraries correspond to AND/OR graphs that may be cyclic and
where children of AND nodes may be partially ordered. These libraries include
Context-Free Grammars as a special case, where the Plan Recognition problem
becomes a parsing with missing tokens problem. Plan Recognition over the
standard libraries become Planning problems that can be easily solved by any
modern planner, while recognition over more complex libraries, including
Context-Free Grammars (CFGs), illustrate limitations of current Planning
heuristics and suggest improvements that may be relevant in other Planning
problems too.


title: Optimal Inference for Distributed Detection

abstract:
  In distributed detection, there does not exist an automatic way of generating
optimal decision strategies for non-affine decision functions. Consequently, in
a detection problem based on a non-affine decision function, establishing
optimality of a given decision strategy, such as a generalized likelihood ratio
test, is often difficult or even impossible.
  In this thesis we develop a novel detection network optimization technique
that can be used to determine necessary and sufficient conditions for
optimality in distributed detection for which the underlying objective function
is monotonic and convex in probabilistic decision strategies. Our developed
approach leverages on basic concepts of optimization and statistical inference
which are provided in sufficient detail. These basic concepts are combined to
form the basis of an optimal inference technique for signal detection.
  We prove a central theorem that characterizes optimality in a variety of
distributed detection architectures. We discuss three applications of this
result in distributed signal detection. These applications include interactive
distributed detection, optimal tandem fusion architecture, and distributed
detection by acyclic graph networks. In the conclusion we indicate several
future research directions, which include possible generalizations of our
optimization method and new research problems arising from each of the three
applications considered.


title:
Elastic proton scattering on 13C and 15C nuclei in the diffraction
  theory

abstract:
  There is a calculation of the differential cross sections of proton
scattering on 13C and 15C nuclei at energy of 1 GeV with the shell model wave
functions in the framework of the Glauber theory in the study. The single,
double and triple collisions have been taken into account in the multiple
scattering operator. The role of each term of the series and their interference
in the differential cross section have been estimated. It is shown that for a
description of the cross sections in a wide angle/momentum transfer range it is
necessary to consider not only the first, but the higher scattering orders.


title: The Design of the NetBSD I/O Subsystems

abstract:
  This book describes the source code of the NetBSD Operating System Release
1.6 in SUN UltraSPARC 64-bit platform by annotating related excerpts from
references and user manuals on the NetBSD Operating System. The goal of this
book is to provide necessary information to understand the operation and the
implementation of I/O subsystems in the kernel as well as to design and
implement a new filesystem on the NetBSD platform.


title: Optical spectroscopy of Be/gamma-ray binaries

abstract:
  We report optical spectroscopic observations of the Be/gamma-ray binaries
LSI+61303, MWC 148 and MWC 656. The peak separation and equivalent widths of
prominent emission lines (H-alpha, H-beta, H-gamma, HeI, and FeII) are
measured. We estimated the circumstellar disc size, compared it with separation
between the components, and discussed the disc truncation. We find that in
LSI+61303 the compact object comes into contact with the outer parts of the
circumstellar disc at periastron, in MWC 148 the compact object goes deeply
into the disc during the periastron passage, and in MWC 656 the black hole is
accreting from the outer parts of the circumstellar disc along the entire
orbit.
  The interstellar extinction was estimated using interstellar lines. The
rotation of the mass donors appears to be similar to the rotation of the mass
donors in Be/X-ray binaries. We suggest that X-ray/optical periodicity of about
1 day deserves to be searched for.


title: Polynomial Carleson operators along monomial curves in the plane

abstract:
  We prove $L^p$ bounds for partial polynomial Carleson operators along
monomial curves $(t,t^m)$ in the plane $\mathbb{R}^2$ with a phase polynomial
consisting of a single monomial. These operators are "partial" in the sense
that we consider linearizing stopping-time functions that depend on only one of
the two ambient variables. A motivation for studying these partial operators is
the curious feature that, despite their apparent limitations, for certain
combinations of curve and phase, $L^2$ bounds for partial operators along
curves imply the full strength of the $L^2$ bound for a one-dimensional
Carleson operator, and for a quadratic Carleson operator. Our methods, which
can at present only treat certain combinations of curves and phases, in some
cases adapt a $TT^*$ method to treat phases involving fractional monomials, and
in other cases use a known vector-valued variant of the Carleson-Hunt theorem.


title: Dimensional regularization is generic

abstract:
  The absence of the quadratic divergence in the Higgs sector of the Standard
Model in the dimensional regularization is usually regarded to be an
exceptional property of a specific regularization. To understand what is going
on in the dimensional regularization, we illustrate how to reproduce the
results of the dimensional regularization for the $\lambda\phi^{4}$ theory in
the more conventional regularization such as the higher derivative
regularization; the basic postulate involved is that the quadratically
divergent induced mass, which is independent of the scale change of the
physical mass, is kinematical and unphysical. This is consistent with the
derivation of the Callan-Symanzik equation, which is a comparison of two
theories with slightly different masses, for the $\lambda\phi^{4}$ theory
without encountering the quadratic divergence. We thus suggest that the
dimensional regularization is generic in a bottom-up approach starting with a
successful low-energy theory. We also define a modified version of the mass
independent renormalization for a scalar field which leads to the homogeneous
renormalization group equation. Implications of the present analysis on the
Standard Model at high energies and the presence or absence of SUSY at LHC
energies are briefly discussed.


title: Some Mathematical Aspects of Price Optimisation

abstract:
  Calculation of an optimal tariff is a principal challenge for pricing
actuaries. In this contribution we are concerned with the renewal insurance
business discussing various mathematical aspects of calculation of an optimal
renewal tariff. Our motivation comes from two important actuarial tasks, namely
a) construction of an optimal renewal tariff subject to business and technical
constraints, and b) determination of an optimal allocation of certain premium
loadings. We consider both continuous and discrete optimisation and then
present several algorithmic sub-optimal solutions. Additionally, we explore
some simulation techniques. Several illustrative examples show both the
complexity and the importance of the optimisation approach.